1 /*- 2 * Copyright (c) 2016-9 Netflix, Inc. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 * 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_inet.h" 31 #include "opt_inet6.h" 32 #include "opt_ipsec.h" 33 #include "opt_tcpdebug.h" 34 #include "opt_ratelimit.h" 35 #include "opt_kern_tls.h" 36 #include <sys/param.h> 37 #include <sys/arb.h> 38 #include <sys/module.h> 39 #include <sys/kernel.h> 40 #ifdef TCP_HHOOK 41 #include <sys/hhook.h> 42 #endif 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/lock.h> 46 #include <sys/mutex.h> 47 #include <sys/mbuf.h> 48 #include <sys/proc.h> /* for proc0 declaration */ 49 #include <sys/socket.h> 50 #include <sys/socketvar.h> 51 #ifdef KERN_TLS 52 #include <sys/ktls.h> 53 #endif 54 #include <sys/sysctl.h> 55 #include <sys/systm.h> 56 #ifdef STATS 57 #include <sys/qmath.h> 58 #include <sys/tree.h> 59 #include <sys/stats.h> /* Must come after qmath.h and tree.h */ 60 #endif 61 #include <sys/refcount.h> 62 #include <sys/tree.h> 63 #include <sys/queue.h> 64 #include <sys/smp.h> 65 #include <sys/kthread.h> 66 #include <sys/kern_prefetch.h> 67 68 #include <vm/uma.h> 69 70 #include <net/route.h> 71 #include <net/vnet.h> 72 73 #define TCPSTATES /* for logging */ 74 75 #include <netinet/in.h> 76 #include <netinet/in_kdtrace.h> 77 #include <netinet/in_pcb.h> 78 #include <netinet/ip.h> 79 #include <netinet/ip_icmp.h> /* required for icmp_var.h */ 80 #include <netinet/icmp_var.h> /* for ICMP_BANDLIM */ 81 #include <netinet/ip_var.h> 82 #include <netinet/ip6.h> 83 #include <netinet6/in6_pcb.h> 84 #include <netinet6/ip6_var.h> 85 #include <netinet/tcp.h> 86 #define TCPOUTFLAGS 87 #include <netinet/tcp_fsm.h> 88 #include <netinet/tcp_log_buf.h> 89 #include <netinet/tcp_seq.h> 90 #include <netinet/tcp_timer.h> 91 #include <netinet/tcp_var.h> 92 #include <netinet/tcp_hpts.h> 93 #include <netinet/tcpip.h> 94 #include <netinet/cc/cc.h> 95 #include <netinet/tcp_fastopen.h> 96 #include <netinet/tcp_lro.h> 97 #ifdef TCPDEBUG 98 #include <netinet/tcp_debug.h> 99 #endif /* TCPDEBUG */ 100 #ifdef TCP_OFFLOAD 101 #include <netinet/tcp_offload.h> 102 #endif 103 #ifdef INET6 104 #include <netinet6/tcp6_var.h> 105 #endif 106 107 #include <netipsec/ipsec_support.h> 108 109 #if defined(IPSEC) || defined(IPSEC_SUPPORT) 110 #include <netipsec/ipsec.h> 111 #include <netipsec/ipsec6.h> 112 #endif /* IPSEC */ 113 114 #include <netinet/udp.h> 115 #include <netinet/udp_var.h> 116 #include <machine/in_cksum.h> 117 118 #ifdef MAC 119 #include <security/mac/mac_framework.h> 120 #endif 121 #include "sack_filter.h" 122 #include "tcp_rack.h" 123 #include "rack_bbr_common.h" 124 125 uma_zone_t rack_zone; 126 uma_zone_t rack_pcb_zone; 127 128 #ifndef TICKS2SBT 129 #define TICKS2SBT(__t) (tick_sbt * ((sbintime_t)(__t))) 130 #endif 131 132 struct sysctl_ctx_list rack_sysctl_ctx; 133 struct sysctl_oid *rack_sysctl_root; 134 135 #define CUM_ACKED 1 136 #define SACKED 2 137 138 /* 139 * The RACK module incorporates a number of 140 * TCP ideas that have been put out into the IETF 141 * over the last few years: 142 * - Matt Mathis's Rate Halving which slowly drops 143 * the congestion window so that the ack clock can 144 * be maintained during a recovery. 145 * - Yuchung Cheng's RACK TCP (for which its named) that 146 * will stop us using the number of dup acks and instead 147 * use time as the gage of when we retransmit. 148 * - Reorder Detection of RFC4737 and the Tail-Loss probe draft 149 * of Dukkipati et.al. 150 * RACK depends on SACK, so if an endpoint arrives that 151 * cannot do SACK the state machine below will shuttle the 152 * connection back to using the "default" TCP stack that is 153 * in FreeBSD. 154 * 155 * To implement RACK the original TCP stack was first decomposed 156 * into a functional state machine with individual states 157 * for each of the possible TCP connection states. The do_segement 158 * functions role in life is to mandate the connection supports SACK 159 * initially and then assure that the RACK state matches the conenction 160 * state before calling the states do_segment function. Each 161 * state is simplified due to the fact that the original do_segment 162 * has been decomposed and we *know* what state we are in (no 163 * switches on the state) and all tests for SACK are gone. This 164 * greatly simplifies what each state does. 165 * 166 * TCP output is also over-written with a new version since it 167 * must maintain the new rack scoreboard. 168 * 169 */ 170 static int32_t rack_tlp_thresh = 1; 171 static int32_t rack_reorder_thresh = 2; 172 static int32_t rack_reorder_fade = 60000; /* 0 - never fade, def 60,000 173 * - 60 seconds */ 174 /* Attack threshold detections */ 175 static uint32_t rack_highest_sack_thresh_seen = 0; 176 static uint32_t rack_highest_move_thresh_seen = 0; 177 178 static int32_t rack_pkt_delay = 1; 179 static int32_t rack_min_pace_time = 0; 180 static int32_t rack_early_recovery = 1; 181 static int32_t rack_send_a_lot_in_prr = 1; 182 static int32_t rack_min_to = 1; /* Number of ms minimum timeout */ 183 static int32_t rack_verbose_logging = 0; 184 static int32_t rack_ignore_data_after_close = 1; 185 static int32_t use_rack_cheat = 1; 186 static int32_t rack_persist_min = 250; /* 250ms */ 187 static int32_t rack_persist_max = 1000; /* 1 Second */ 188 static int32_t rack_sack_not_required = 0; /* set to one to allow non-sack to use rack */ 189 static int32_t rack_hw_tls_max_seg = 0; /* 0 means use hw-tls single segment */ 190 191 /* 192 * Currently regular tcp has a rto_min of 30ms 193 * the backoff goes 12 times so that ends up 194 * being a total of 122.850 seconds before a 195 * connection is killed. 196 */ 197 static int32_t rack_tlp_min = 10; 198 static int32_t rack_rto_min = 30; /* 30ms same as main freebsd */ 199 static int32_t rack_rto_max = 4000; /* 4 seconds */ 200 static const int32_t rack_free_cache = 2; 201 static int32_t rack_hptsi_segments = 40; 202 static int32_t rack_rate_sample_method = USE_RTT_LOW; 203 static int32_t rack_pace_every_seg = 0; 204 static int32_t rack_delayed_ack_time = 200; /* 200ms */ 205 static int32_t rack_slot_reduction = 4; 206 static int32_t rack_lower_cwnd_at_tlp = 0; 207 static int32_t rack_use_proportional_reduce = 0; 208 static int32_t rack_proportional_rate = 10; 209 static int32_t rack_tlp_max_resend = 2; 210 static int32_t rack_limited_retran = 0; 211 static int32_t rack_always_send_oldest = 0; 212 static int32_t rack_use_sack_filter = 1; 213 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE; 214 static int32_t rack_per_of_gp = 50; 215 216 /* Rack specific counters */ 217 counter_u64_t rack_badfr; 218 counter_u64_t rack_badfr_bytes; 219 counter_u64_t rack_rtm_prr_retran; 220 counter_u64_t rack_rtm_prr_newdata; 221 counter_u64_t rack_timestamp_mismatch; 222 counter_u64_t rack_reorder_seen; 223 counter_u64_t rack_paced_segments; 224 counter_u64_t rack_unpaced_segments; 225 counter_u64_t rack_calc_zero; 226 counter_u64_t rack_calc_nonzero; 227 counter_u64_t rack_saw_enobuf; 228 counter_u64_t rack_saw_enetunreach; 229 counter_u64_t rack_per_timer_hole; 230 231 /* Tail loss probe counters */ 232 counter_u64_t rack_tlp_tot; 233 counter_u64_t rack_tlp_newdata; 234 counter_u64_t rack_tlp_retran; 235 counter_u64_t rack_tlp_retran_bytes; 236 counter_u64_t rack_tlp_retran_fail; 237 counter_u64_t rack_to_tot; 238 counter_u64_t rack_to_arm_rack; 239 counter_u64_t rack_to_arm_tlp; 240 counter_u64_t rack_to_alloc; 241 counter_u64_t rack_to_alloc_hard; 242 counter_u64_t rack_to_alloc_emerg; 243 counter_u64_t rack_to_alloc_limited; 244 counter_u64_t rack_alloc_limited_conns; 245 counter_u64_t rack_split_limited; 246 247 counter_u64_t rack_sack_proc_all; 248 counter_u64_t rack_sack_proc_short; 249 counter_u64_t rack_sack_proc_restart; 250 counter_u64_t rack_sack_attacks_detected; 251 counter_u64_t rack_sack_attacks_reversed; 252 counter_u64_t rack_sack_used_next_merge; 253 counter_u64_t rack_sack_splits; 254 counter_u64_t rack_sack_used_prev_merge; 255 counter_u64_t rack_sack_skipped_acked; 256 counter_u64_t rack_ack_total; 257 counter_u64_t rack_express_sack; 258 counter_u64_t rack_sack_total; 259 counter_u64_t rack_move_none; 260 counter_u64_t rack_move_some; 261 262 counter_u64_t rack_used_tlpmethod; 263 counter_u64_t rack_used_tlpmethod2; 264 counter_u64_t rack_enter_tlp_calc; 265 counter_u64_t rack_input_idle_reduces; 266 counter_u64_t rack_collapsed_win; 267 counter_u64_t rack_tlp_does_nada; 268 269 /* Counters for HW TLS */ 270 counter_u64_t rack_tls_rwnd; 271 counter_u64_t rack_tls_cwnd; 272 counter_u64_t rack_tls_app; 273 counter_u64_t rack_tls_other; 274 counter_u64_t rack_tls_filled; 275 counter_u64_t rack_tls_rxt; 276 counter_u64_t rack_tls_tlp; 277 278 /* Temp CPU counters */ 279 counter_u64_t rack_find_high; 280 281 counter_u64_t rack_progress_drops; 282 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE]; 283 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE]; 284 285 static void 286 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick, int event, int line); 287 288 static int 289 rack_process_ack(struct mbuf *m, struct tcphdr *th, 290 struct socket *so, struct tcpcb *tp, struct tcpopt *to, 291 uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val); 292 static int 293 rack_process_data(struct mbuf *m, struct tcphdr *th, 294 struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, 295 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt); 296 static void 297 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, 298 struct tcphdr *th, uint16_t nsegs, uint16_t type, int32_t recovery); 299 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack); 300 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack, 301 uint8_t limit_type); 302 static struct rack_sendmap * 303 rack_check_recovery_mode(struct tcpcb *tp, 304 uint32_t tsused); 305 static void 306 rack_cong_signal(struct tcpcb *tp, struct tcphdr *th, 307 uint32_t type); 308 static void rack_counter_destroy(void); 309 static int 310 rack_ctloutput(struct socket *so, struct sockopt *sopt, 311 struct inpcb *inp, struct tcpcb *tp); 312 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how); 313 static void 314 rack_do_segment(struct mbuf *m, struct tcphdr *th, 315 struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, 316 uint8_t iptos); 317 static void rack_dtor(void *mem, int32_t size, void *arg); 318 static void 319 rack_earlier_retran(struct tcpcb *tp, struct rack_sendmap *rsm, 320 uint32_t t, uint32_t cts); 321 static struct rack_sendmap * 322 rack_find_high_nonack(struct tcp_rack *rack, 323 struct rack_sendmap *rsm); 324 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack); 325 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm); 326 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged); 327 static int 328 rack_get_sockopt(struct socket *so, struct sockopt *sopt, 329 struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack); 330 static int32_t rack_handoff_ok(struct tcpcb *tp); 331 static int32_t rack_init(struct tcpcb *tp); 332 static void rack_init_sysctls(void); 333 static void 334 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, 335 struct tcphdr *th); 336 static void 337 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len, 338 uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t ts, 339 uint8_t pass, struct rack_sendmap *hintrsm); 340 static void 341 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack, 342 struct rack_sendmap *rsm); 343 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, int num); 344 static int32_t rack_output(struct tcpcb *tp); 345 346 static uint32_t 347 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, 348 struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm, 349 uint32_t cts, int *moved_two); 350 static void rack_post_recovery(struct tcpcb *tp, struct tcphdr *th); 351 static void rack_remxt_tmr(struct tcpcb *tp); 352 static int 353 rack_set_sockopt(struct socket *so, struct sockopt *sopt, 354 struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack); 355 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack); 356 static int32_t rack_stopall(struct tcpcb *tp); 357 static void 358 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, 359 uint32_t delta); 360 static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type); 361 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line); 362 static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type); 363 static uint32_t 364 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack, 365 struct rack_sendmap *rsm, uint32_t ts, int32_t * lenp); 366 static void 367 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack, 368 struct rack_sendmap *rsm, uint32_t ts); 369 static int 370 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack, 371 struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type); 372 static int32_t tcp_addrack(module_t mod, int32_t type, void *data); 373 static int 374 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, 375 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 376 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 377 static int 378 rack_do_closing(struct mbuf *m, struct tcphdr *th, 379 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 380 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 381 static int 382 rack_do_established(struct mbuf *m, struct tcphdr *th, 383 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 384 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 385 static int 386 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, 387 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 388 int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos); 389 static int 390 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, 391 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 392 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 393 static int 394 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, 395 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 396 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 397 static int 398 rack_do_lastack(struct mbuf *m, struct tcphdr *th, 399 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 400 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 401 static int 402 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, 403 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 404 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 405 static int 406 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, 407 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 408 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 409 struct rack_sendmap * 410 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, 411 uint32_t tsused); 412 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt); 413 static void 414 tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th); 415 416 int32_t rack_clear_counter=0; 417 418 419 static int 420 sysctl_rack_clear(SYSCTL_HANDLER_ARGS) 421 { 422 uint32_t stat; 423 int32_t error; 424 425 error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t)); 426 if (error || req->newptr == NULL) 427 return error; 428 429 error = SYSCTL_IN(req, &stat, sizeof(uint32_t)); 430 if (error) 431 return (error); 432 if (stat == 1) { 433 #ifdef INVARIANTS 434 printf("Clearing RACK counters\n"); 435 #endif 436 counter_u64_zero(rack_badfr); 437 counter_u64_zero(rack_badfr_bytes); 438 counter_u64_zero(rack_rtm_prr_retran); 439 counter_u64_zero(rack_rtm_prr_newdata); 440 counter_u64_zero(rack_timestamp_mismatch); 441 counter_u64_zero(rack_reorder_seen); 442 counter_u64_zero(rack_tlp_tot); 443 counter_u64_zero(rack_tlp_newdata); 444 counter_u64_zero(rack_tlp_retran); 445 counter_u64_zero(rack_tlp_retran_bytes); 446 counter_u64_zero(rack_tlp_retran_fail); 447 counter_u64_zero(rack_to_tot); 448 counter_u64_zero(rack_to_arm_rack); 449 counter_u64_zero(rack_to_arm_tlp); 450 counter_u64_zero(rack_paced_segments); 451 counter_u64_zero(rack_calc_zero); 452 counter_u64_zero(rack_calc_nonzero); 453 counter_u64_zero(rack_unpaced_segments); 454 counter_u64_zero(rack_saw_enobuf); 455 counter_u64_zero(rack_saw_enetunreach); 456 counter_u64_zero(rack_per_timer_hole); 457 counter_u64_zero(rack_to_alloc_hard); 458 counter_u64_zero(rack_to_alloc_emerg); 459 counter_u64_zero(rack_sack_proc_all); 460 counter_u64_zero(rack_sack_proc_short); 461 counter_u64_zero(rack_sack_proc_restart); 462 counter_u64_zero(rack_to_alloc); 463 counter_u64_zero(rack_to_alloc_limited); 464 counter_u64_zero(rack_alloc_limited_conns); 465 counter_u64_zero(rack_split_limited); 466 counter_u64_zero(rack_find_high); 467 counter_u64_zero(rack_tls_rwnd); 468 counter_u64_zero(rack_tls_cwnd); 469 counter_u64_zero(rack_tls_app); 470 counter_u64_zero(rack_tls_other); 471 counter_u64_zero(rack_tls_filled); 472 counter_u64_zero(rack_tls_rxt); 473 counter_u64_zero(rack_tls_tlp); 474 counter_u64_zero(rack_sack_attacks_detected); 475 counter_u64_zero(rack_sack_attacks_reversed); 476 counter_u64_zero(rack_sack_used_next_merge); 477 counter_u64_zero(rack_sack_used_prev_merge); 478 counter_u64_zero(rack_sack_splits); 479 counter_u64_zero(rack_sack_skipped_acked); 480 counter_u64_zero(rack_ack_total); 481 counter_u64_zero(rack_express_sack); 482 counter_u64_zero(rack_sack_total); 483 counter_u64_zero(rack_move_none); 484 counter_u64_zero(rack_move_some); 485 counter_u64_zero(rack_used_tlpmethod); 486 counter_u64_zero(rack_used_tlpmethod2); 487 counter_u64_zero(rack_enter_tlp_calc); 488 counter_u64_zero(rack_progress_drops); 489 counter_u64_zero(rack_tlp_does_nada); 490 counter_u64_zero(rack_collapsed_win); 491 492 } 493 rack_clear_counter = 0; 494 return (0); 495 } 496 497 498 499 static void 500 rack_init_sysctls(void) 501 { 502 struct sysctl_oid *rack_counters; 503 struct sysctl_oid *rack_attack; 504 505 SYSCTL_ADD_S32(&rack_sysctl_ctx, 506 SYSCTL_CHILDREN(rack_sysctl_root), 507 OID_AUTO, "rate_sample_method", CTLFLAG_RW, 508 &rack_rate_sample_method , USE_RTT_LOW, 509 "What method should we use for rate sampling 0=high, 1=low "); 510 SYSCTL_ADD_S32(&rack_sysctl_ctx, 511 SYSCTL_CHILDREN(rack_sysctl_root), 512 OID_AUTO, "hw_tlsmax", CTLFLAG_RW, 513 &rack_hw_tls_max_seg , 0, 514 "Do we have a multplier of TLS records we can send as a max (0=1 TLS record)? "); 515 SYSCTL_ADD_S32(&rack_sysctl_ctx, 516 SYSCTL_CHILDREN(rack_sysctl_root), 517 OID_AUTO, "data_after_close", CTLFLAG_RW, 518 &rack_ignore_data_after_close, 0, 519 "Do we hold off sending a RST until all pending data is ack'd"); 520 SYSCTL_ADD_S32(&rack_sysctl_ctx, 521 SYSCTL_CHILDREN(rack_sysctl_root), 522 OID_AUTO, "cheat_rxt", CTLFLAG_RW, 523 &use_rack_cheat, 1, 524 "Do we use the rxt cheat for rack?"); 525 526 SYSCTL_ADD_U32(&rack_sysctl_ctx, 527 SYSCTL_CHILDREN(rack_sysctl_root), 528 OID_AUTO, "persmin", CTLFLAG_RW, 529 &rack_persist_min, 250, 530 "What is the minimum time in milliseconds between persists"); 531 SYSCTL_ADD_U32(&rack_sysctl_ctx, 532 SYSCTL_CHILDREN(rack_sysctl_root), 533 OID_AUTO, "persmax", CTLFLAG_RW, 534 &rack_persist_max, 1000, 535 "What is the largest delay in milliseconds between persists"); 536 SYSCTL_ADD_S32(&rack_sysctl_ctx, 537 SYSCTL_CHILDREN(rack_sysctl_root), 538 OID_AUTO, "no_sack_needed", CTLFLAG_RW, 539 &rack_sack_not_required, 0, 540 "Do we allow rack to run on connections not supporting SACK?"); 541 SYSCTL_ADD_S32(&rack_sysctl_ctx, 542 SYSCTL_CHILDREN(rack_sysctl_root), 543 OID_AUTO, "tlpmethod", CTLFLAG_RW, 544 &rack_tlp_threshold_use, TLP_USE_TWO_ONE, 545 "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2"); 546 SYSCTL_ADD_S32(&rack_sysctl_ctx, 547 SYSCTL_CHILDREN(rack_sysctl_root), 548 OID_AUTO, "gp_percentage", CTLFLAG_RW, 549 &rack_per_of_gp, 50, 550 "Do we pace to percentage of goodput (0=old method)?"); 551 SYSCTL_ADD_S32(&rack_sysctl_ctx, 552 SYSCTL_CHILDREN(rack_sysctl_root), 553 OID_AUTO, "min_pace_time", CTLFLAG_RW, 554 &rack_min_pace_time, 0, 555 "Should we enforce a minimum pace time of 1ms"); 556 SYSCTL_ADD_S32(&rack_sysctl_ctx, 557 SYSCTL_CHILDREN(rack_sysctl_root), 558 OID_AUTO, "bb_verbose", CTLFLAG_RW, 559 &rack_verbose_logging, 0, 560 "Should RACK black box logging be verbose"); 561 SYSCTL_ADD_S32(&rack_sysctl_ctx, 562 SYSCTL_CHILDREN(rack_sysctl_root), 563 OID_AUTO, "sackfiltering", CTLFLAG_RW, 564 &rack_use_sack_filter, 1, 565 "Do we use sack filtering?"); 566 SYSCTL_ADD_S32(&rack_sysctl_ctx, 567 SYSCTL_CHILDREN(rack_sysctl_root), 568 OID_AUTO, "delayed_ack", CTLFLAG_RW, 569 &rack_delayed_ack_time, 200, 570 "Delayed ack time (200ms)"); 571 SYSCTL_ADD_S32(&rack_sysctl_ctx, 572 SYSCTL_CHILDREN(rack_sysctl_root), 573 OID_AUTO, "tlpminto", CTLFLAG_RW, 574 &rack_tlp_min, 10, 575 "TLP minimum timeout per the specification (10ms)"); 576 SYSCTL_ADD_S32(&rack_sysctl_ctx, 577 SYSCTL_CHILDREN(rack_sysctl_root), 578 OID_AUTO, "send_oldest", CTLFLAG_RW, 579 &rack_always_send_oldest, 1, 580 "Should we always send the oldest TLP and RACK-TLP"); 581 SYSCTL_ADD_S32(&rack_sysctl_ctx, 582 SYSCTL_CHILDREN(rack_sysctl_root), 583 OID_AUTO, "rack_tlimit", CTLFLAG_RW, 584 &rack_limited_retran, 0, 585 "How many times can a rack timeout drive out sends"); 586 SYSCTL_ADD_S32(&rack_sysctl_ctx, 587 SYSCTL_CHILDREN(rack_sysctl_root), 588 OID_AUTO, "minrto", CTLFLAG_RW, 589 &rack_rto_min, 0, 590 "Minimum RTO in ms -- set with caution below 1000 due to TLP"); 591 SYSCTL_ADD_S32(&rack_sysctl_ctx, 592 SYSCTL_CHILDREN(rack_sysctl_root), 593 OID_AUTO, "maxrto", CTLFLAG_RW, 594 &rack_rto_max, 0, 595 "Maxiumum RTO in ms -- should be at least as large as min_rto"); 596 SYSCTL_ADD_S32(&rack_sysctl_ctx, 597 SYSCTL_CHILDREN(rack_sysctl_root), 598 OID_AUTO, "tlp_retry", CTLFLAG_RW, 599 &rack_tlp_max_resend, 2, 600 "How many times does TLP retry a single segment or multiple with no ACK"); 601 SYSCTL_ADD_S32(&rack_sysctl_ctx, 602 SYSCTL_CHILDREN(rack_sysctl_root), 603 OID_AUTO, "recovery_loss_prop", CTLFLAG_RW, 604 &rack_use_proportional_reduce, 0, 605 "Should we proportionaly reduce cwnd based on the number of losses "); 606 SYSCTL_ADD_S32(&rack_sysctl_ctx, 607 SYSCTL_CHILDREN(rack_sysctl_root), 608 OID_AUTO, "recovery_prop", CTLFLAG_RW, 609 &rack_proportional_rate, 10, 610 "What percent reduction per loss"); 611 SYSCTL_ADD_S32(&rack_sysctl_ctx, 612 SYSCTL_CHILDREN(rack_sysctl_root), 613 OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW, 614 &rack_lower_cwnd_at_tlp, 0, 615 "When a TLP completes a retran should we enter recovery?"); 616 SYSCTL_ADD_S32(&rack_sysctl_ctx, 617 SYSCTL_CHILDREN(rack_sysctl_root), 618 OID_AUTO, "hptsi_reduces", CTLFLAG_RW, 619 &rack_slot_reduction, 4, 620 "When setting a slot should we reduce by divisor"); 621 SYSCTL_ADD_S32(&rack_sysctl_ctx, 622 SYSCTL_CHILDREN(rack_sysctl_root), 623 OID_AUTO, "hptsi_every_seg", CTLFLAG_RW, 624 &rack_pace_every_seg, 0, 625 "Should we use the original pacing mechanism that did not pace much?"); 626 SYSCTL_ADD_S32(&rack_sysctl_ctx, 627 SYSCTL_CHILDREN(rack_sysctl_root), 628 OID_AUTO, "hptsi_seg_max", CTLFLAG_RW, 629 &rack_hptsi_segments, 40, 630 "Should we pace out only a limited size of segments"); 631 SYSCTL_ADD_S32(&rack_sysctl_ctx, 632 SYSCTL_CHILDREN(rack_sysctl_root), 633 OID_AUTO, "prr_sendalot", CTLFLAG_RW, 634 &rack_send_a_lot_in_prr, 1, 635 "Send a lot in prr"); 636 SYSCTL_ADD_S32(&rack_sysctl_ctx, 637 SYSCTL_CHILDREN(rack_sysctl_root), 638 OID_AUTO, "minto", CTLFLAG_RW, 639 &rack_min_to, 1, 640 "Minimum rack timeout in milliseconds"); 641 SYSCTL_ADD_S32(&rack_sysctl_ctx, 642 SYSCTL_CHILDREN(rack_sysctl_root), 643 OID_AUTO, "earlyrecovery", CTLFLAG_RW, 644 &rack_early_recovery, 1, 645 "Do we do early recovery with rack"); 646 SYSCTL_ADD_S32(&rack_sysctl_ctx, 647 SYSCTL_CHILDREN(rack_sysctl_root), 648 OID_AUTO, "reorder_thresh", CTLFLAG_RW, 649 &rack_reorder_thresh, 2, 650 "What factor for rack will be added when seeing reordering (shift right)"); 651 SYSCTL_ADD_S32(&rack_sysctl_ctx, 652 SYSCTL_CHILDREN(rack_sysctl_root), 653 OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW, 654 &rack_tlp_thresh, 1, 655 "what divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)"); 656 SYSCTL_ADD_S32(&rack_sysctl_ctx, 657 SYSCTL_CHILDREN(rack_sysctl_root), 658 OID_AUTO, "reorder_fade", CTLFLAG_RW, 659 &rack_reorder_fade, 0, 660 "Does reorder detection fade, if so how many ms (0 means never)"); 661 SYSCTL_ADD_S32(&rack_sysctl_ctx, 662 SYSCTL_CHILDREN(rack_sysctl_root), 663 OID_AUTO, "pktdelay", CTLFLAG_RW, 664 &rack_pkt_delay, 1, 665 "Extra RACK time (in ms) besides reordering thresh"); 666 667 rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx, 668 SYSCTL_CHILDREN(rack_sysctl_root), 669 OID_AUTO, 670 "stats", 671 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 672 "Rack Counters"); 673 rack_badfr = counter_u64_alloc(M_WAITOK); 674 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 675 SYSCTL_CHILDREN(rack_counters), 676 OID_AUTO, "badfr", CTLFLAG_RD, 677 &rack_badfr, "Total number of bad FRs"); 678 rack_badfr_bytes = counter_u64_alloc(M_WAITOK); 679 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 680 SYSCTL_CHILDREN(rack_counters), 681 OID_AUTO, "badfr_bytes", CTLFLAG_RD, 682 &rack_badfr_bytes, "Total number of bad FRs"); 683 rack_rtm_prr_retran = counter_u64_alloc(M_WAITOK); 684 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 685 SYSCTL_CHILDREN(rack_counters), 686 OID_AUTO, "prrsndret", CTLFLAG_RD, 687 &rack_rtm_prr_retran, 688 "Total number of prr based retransmits"); 689 rack_rtm_prr_newdata = counter_u64_alloc(M_WAITOK); 690 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 691 SYSCTL_CHILDREN(rack_counters), 692 OID_AUTO, "prrsndnew", CTLFLAG_RD, 693 &rack_rtm_prr_newdata, 694 "Total number of prr based new transmits"); 695 rack_timestamp_mismatch = counter_u64_alloc(M_WAITOK); 696 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 697 SYSCTL_CHILDREN(rack_counters), 698 OID_AUTO, "tsnf", CTLFLAG_RD, 699 &rack_timestamp_mismatch, 700 "Total number of timestamps that we could not find the reported ts"); 701 rack_find_high = counter_u64_alloc(M_WAITOK); 702 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 703 SYSCTL_CHILDREN(rack_counters), 704 OID_AUTO, "findhigh", CTLFLAG_RD, 705 &rack_find_high, 706 "Total number of FIN causing find-high"); 707 rack_reorder_seen = counter_u64_alloc(M_WAITOK); 708 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 709 SYSCTL_CHILDREN(rack_counters), 710 OID_AUTO, "reordering", CTLFLAG_RD, 711 &rack_reorder_seen, 712 "Total number of times we added delay due to reordering"); 713 rack_tlp_tot = counter_u64_alloc(M_WAITOK); 714 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 715 SYSCTL_CHILDREN(rack_counters), 716 OID_AUTO, "tlp_to_total", CTLFLAG_RD, 717 &rack_tlp_tot, 718 "Total number of tail loss probe expirations"); 719 rack_tlp_newdata = counter_u64_alloc(M_WAITOK); 720 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 721 SYSCTL_CHILDREN(rack_counters), 722 OID_AUTO, "tlp_new", CTLFLAG_RD, 723 &rack_tlp_newdata, 724 "Total number of tail loss probe sending new data"); 725 726 rack_tlp_retran = counter_u64_alloc(M_WAITOK); 727 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 728 SYSCTL_CHILDREN(rack_counters), 729 OID_AUTO, "tlp_retran", CTLFLAG_RD, 730 &rack_tlp_retran, 731 "Total number of tail loss probe sending retransmitted data"); 732 rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK); 733 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 734 SYSCTL_CHILDREN(rack_counters), 735 OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD, 736 &rack_tlp_retran_bytes, 737 "Total bytes of tail loss probe sending retransmitted data"); 738 rack_tlp_retran_fail = counter_u64_alloc(M_WAITOK); 739 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 740 SYSCTL_CHILDREN(rack_counters), 741 OID_AUTO, "tlp_retran_fail", CTLFLAG_RD, 742 &rack_tlp_retran_fail, 743 "Total number of tail loss probe sending retransmitted data that failed (wait for t3)"); 744 rack_to_tot = counter_u64_alloc(M_WAITOK); 745 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 746 SYSCTL_CHILDREN(rack_counters), 747 OID_AUTO, "rack_to_tot", CTLFLAG_RD, 748 &rack_to_tot, 749 "Total number of times the rack to expired?"); 750 rack_to_arm_rack = counter_u64_alloc(M_WAITOK); 751 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 752 SYSCTL_CHILDREN(rack_counters), 753 OID_AUTO, "arm_rack", CTLFLAG_RD, 754 &rack_to_arm_rack, 755 "Total number of times the rack timer armed?"); 756 rack_to_arm_tlp = counter_u64_alloc(M_WAITOK); 757 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 758 SYSCTL_CHILDREN(rack_counters), 759 OID_AUTO, "arm_tlp", CTLFLAG_RD, 760 &rack_to_arm_tlp, 761 "Total number of times the tlp timer armed?"); 762 763 rack_calc_zero = counter_u64_alloc(M_WAITOK); 764 rack_calc_nonzero = counter_u64_alloc(M_WAITOK); 765 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 766 SYSCTL_CHILDREN(rack_counters), 767 OID_AUTO, "calc_zero", CTLFLAG_RD, 768 &rack_calc_zero, 769 "Total number of times pacing time worked out to zero?"); 770 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 771 SYSCTL_CHILDREN(rack_counters), 772 OID_AUTO, "calc_nonzero", CTLFLAG_RD, 773 &rack_calc_nonzero, 774 "Total number of times pacing time worked out to non-zero?"); 775 rack_paced_segments = counter_u64_alloc(M_WAITOK); 776 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 777 SYSCTL_CHILDREN(rack_counters), 778 OID_AUTO, "paced", CTLFLAG_RD, 779 &rack_paced_segments, 780 "Total number of times a segment send caused hptsi"); 781 rack_unpaced_segments = counter_u64_alloc(M_WAITOK); 782 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 783 SYSCTL_CHILDREN(rack_counters), 784 OID_AUTO, "unpaced", CTLFLAG_RD, 785 &rack_unpaced_segments, 786 "Total number of times a segment did not cause hptsi"); 787 rack_saw_enobuf = counter_u64_alloc(M_WAITOK); 788 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 789 SYSCTL_CHILDREN(rack_counters), 790 OID_AUTO, "saw_enobufs", CTLFLAG_RD, 791 &rack_saw_enobuf, 792 "Total number of times a segment did not cause hptsi"); 793 rack_saw_enetunreach = counter_u64_alloc(M_WAITOK); 794 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 795 SYSCTL_CHILDREN(rack_counters), 796 OID_AUTO, "saw_enetunreach", CTLFLAG_RD, 797 &rack_saw_enetunreach, 798 "Total number of times a segment did not cause hptsi"); 799 rack_to_alloc = counter_u64_alloc(M_WAITOK); 800 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 801 SYSCTL_CHILDREN(rack_counters), 802 OID_AUTO, "allocs", CTLFLAG_RD, 803 &rack_to_alloc, 804 "Total allocations of tracking structures"); 805 rack_to_alloc_hard = counter_u64_alloc(M_WAITOK); 806 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 807 SYSCTL_CHILDREN(rack_counters), 808 OID_AUTO, "allochard", CTLFLAG_RD, 809 &rack_to_alloc_hard, 810 "Total allocations done with sleeping the hard way"); 811 rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK); 812 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 813 SYSCTL_CHILDREN(rack_counters), 814 OID_AUTO, "allocemerg", CTLFLAG_RD, 815 &rack_to_alloc_emerg, 816 "Total allocations done from emergency cache"); 817 rack_to_alloc_limited = counter_u64_alloc(M_WAITOK); 818 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 819 SYSCTL_CHILDREN(rack_counters), 820 OID_AUTO, "alloc_limited", CTLFLAG_RD, 821 &rack_to_alloc_limited, 822 "Total allocations dropped due to limit"); 823 rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK); 824 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 825 SYSCTL_CHILDREN(rack_counters), 826 OID_AUTO, "alloc_limited_conns", CTLFLAG_RD, 827 &rack_alloc_limited_conns, 828 "Connections with allocations dropped due to limit"); 829 rack_split_limited = counter_u64_alloc(M_WAITOK); 830 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 831 SYSCTL_CHILDREN(rack_counters), 832 OID_AUTO, "split_limited", CTLFLAG_RD, 833 &rack_split_limited, 834 "Split allocations dropped due to limit"); 835 rack_sack_proc_all = counter_u64_alloc(M_WAITOK); 836 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 837 SYSCTL_CHILDREN(rack_counters), 838 OID_AUTO, "sack_long", CTLFLAG_RD, 839 &rack_sack_proc_all, 840 "Total times we had to walk whole list for sack processing"); 841 842 rack_sack_proc_restart = counter_u64_alloc(M_WAITOK); 843 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 844 SYSCTL_CHILDREN(rack_counters), 845 OID_AUTO, "sack_restart", CTLFLAG_RD, 846 &rack_sack_proc_restart, 847 "Total times we had to walk whole list due to a restart"); 848 rack_sack_proc_short = counter_u64_alloc(M_WAITOK); 849 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 850 SYSCTL_CHILDREN(rack_counters), 851 OID_AUTO, "sack_short", CTLFLAG_RD, 852 &rack_sack_proc_short, 853 "Total times we took shortcut for sack processing"); 854 rack_enter_tlp_calc = counter_u64_alloc(M_WAITOK); 855 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 856 SYSCTL_CHILDREN(rack_counters), 857 OID_AUTO, "tlp_calc_entered", CTLFLAG_RD, 858 &rack_enter_tlp_calc, 859 "Total times we called calc-tlp"); 860 rack_used_tlpmethod = counter_u64_alloc(M_WAITOK); 861 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 862 SYSCTL_CHILDREN(rack_counters), 863 OID_AUTO, "hit_tlp_method", CTLFLAG_RD, 864 &rack_used_tlpmethod, 865 "Total number of runt sacks"); 866 rack_used_tlpmethod2 = counter_u64_alloc(M_WAITOK); 867 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 868 SYSCTL_CHILDREN(rack_counters), 869 OID_AUTO, "hit_tlp_method2", CTLFLAG_RD, 870 &rack_used_tlpmethod2, 871 "Total number of times we hit TLP method 2"); 872 /* Sack Attacker detection stuff */ 873 rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx, 874 SYSCTL_CHILDREN(rack_sysctl_root), 875 OID_AUTO, 876 "sack_attack", 877 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 878 "Rack Sack Attack Counters and Controls"); 879 SYSCTL_ADD_U32(&rack_sysctl_ctx, 880 SYSCTL_CHILDREN(rack_attack), 881 OID_AUTO, "detect_highsackratio", CTLFLAG_RW, 882 &rack_highest_sack_thresh_seen, 0, 883 "Highest sack to ack ratio seen"); 884 SYSCTL_ADD_U32(&rack_sysctl_ctx, 885 SYSCTL_CHILDREN(rack_attack), 886 OID_AUTO, "detect_highmoveratio", CTLFLAG_RW, 887 &rack_highest_move_thresh_seen, 0, 888 "Highest move to non-move ratio seen"); 889 rack_ack_total = counter_u64_alloc(M_WAITOK); 890 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 891 SYSCTL_CHILDREN(rack_attack), 892 OID_AUTO, "acktotal", CTLFLAG_RD, 893 &rack_ack_total, 894 "Total number of Ack's"); 895 896 rack_express_sack = counter_u64_alloc(M_WAITOK); 897 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 898 SYSCTL_CHILDREN(rack_attack), 899 OID_AUTO, "exp_sacktotal", CTLFLAG_RD, 900 &rack_express_sack, 901 "Total expresss number of Sack's"); 902 rack_sack_total = counter_u64_alloc(M_WAITOK); 903 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 904 SYSCTL_CHILDREN(rack_attack), 905 OID_AUTO, "sacktotal", CTLFLAG_RD, 906 &rack_sack_total, 907 "Total number of SACK's"); 908 rack_move_none = counter_u64_alloc(M_WAITOK); 909 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 910 SYSCTL_CHILDREN(rack_attack), 911 OID_AUTO, "move_none", CTLFLAG_RD, 912 &rack_move_none, 913 "Total number of SACK index reuse of postions under threshold"); 914 rack_move_some = counter_u64_alloc(M_WAITOK); 915 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 916 SYSCTL_CHILDREN(rack_attack), 917 OID_AUTO, "move_some", CTLFLAG_RD, 918 &rack_move_some, 919 "Total number of SACK index reuse of postions over threshold"); 920 rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK); 921 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 922 SYSCTL_CHILDREN(rack_attack), 923 OID_AUTO, "attacks", CTLFLAG_RD, 924 &rack_sack_attacks_detected, 925 "Total number of SACK attackers that had sack disabled"); 926 rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK); 927 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 928 SYSCTL_CHILDREN(rack_attack), 929 OID_AUTO, "reversed", CTLFLAG_RD, 930 &rack_sack_attacks_reversed, 931 "Total number of SACK attackers that were later determined false positive"); 932 rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK); 933 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 934 SYSCTL_CHILDREN(rack_attack), 935 OID_AUTO, "nextmerge", CTLFLAG_RD, 936 &rack_sack_used_next_merge, 937 "Total number of times we used the next merge"); 938 rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK); 939 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 940 SYSCTL_CHILDREN(rack_attack), 941 OID_AUTO, "prevmerge", CTLFLAG_RD, 942 &rack_sack_used_prev_merge, 943 "Total number of times we used the prev merge"); 944 rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK); 945 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 946 SYSCTL_CHILDREN(rack_attack), 947 OID_AUTO, "skipacked", CTLFLAG_RD, 948 &rack_sack_skipped_acked, 949 "Total number of times we skipped previously sacked"); 950 rack_sack_splits = counter_u64_alloc(M_WAITOK); 951 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 952 SYSCTL_CHILDREN(rack_attack), 953 OID_AUTO, "ofsplit", CTLFLAG_RD, 954 &rack_sack_splits, 955 "Total number of times we did the old fashion tree split"); 956 rack_progress_drops = counter_u64_alloc(M_WAITOK); 957 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 958 SYSCTL_CHILDREN(rack_counters), 959 OID_AUTO, "prog_drops", CTLFLAG_RD, 960 &rack_progress_drops, 961 "Total number of progress drops"); 962 rack_input_idle_reduces = counter_u64_alloc(M_WAITOK); 963 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 964 SYSCTL_CHILDREN(rack_counters), 965 OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD, 966 &rack_input_idle_reduces, 967 "Total number of idle reductions on input"); 968 rack_collapsed_win = counter_u64_alloc(M_WAITOK); 969 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 970 SYSCTL_CHILDREN(rack_counters), 971 OID_AUTO, "collapsed_win", CTLFLAG_RD, 972 &rack_collapsed_win, 973 "Total number of collapsed windows"); 974 rack_tlp_does_nada = counter_u64_alloc(M_WAITOK); 975 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 976 SYSCTL_CHILDREN(rack_counters), 977 OID_AUTO, "tlp_nada", CTLFLAG_RD, 978 &rack_tlp_does_nada, 979 "Total number of nada tlp calls"); 980 981 rack_tls_rwnd = counter_u64_alloc(M_WAITOK); 982 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 983 SYSCTL_CHILDREN(rack_counters), 984 OID_AUTO, "tls_rwnd", CTLFLAG_RD, 985 &rack_tls_rwnd, 986 "Total hdwr tls rwnd limited"); 987 988 rack_tls_cwnd = counter_u64_alloc(M_WAITOK); 989 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 990 SYSCTL_CHILDREN(rack_counters), 991 OID_AUTO, "tls_cwnd", CTLFLAG_RD, 992 &rack_tls_cwnd, 993 "Total hdwr tls cwnd limited"); 994 995 rack_tls_app = counter_u64_alloc(M_WAITOK); 996 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 997 SYSCTL_CHILDREN(rack_counters), 998 OID_AUTO, "tls_app", CTLFLAG_RD, 999 &rack_tls_app, 1000 "Total hdwr tls app limited"); 1001 1002 rack_tls_other = counter_u64_alloc(M_WAITOK); 1003 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 1004 SYSCTL_CHILDREN(rack_counters), 1005 OID_AUTO, "tls_other", CTLFLAG_RD, 1006 &rack_tls_other, 1007 "Total hdwr tls other limited"); 1008 1009 rack_tls_filled = counter_u64_alloc(M_WAITOK); 1010 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 1011 SYSCTL_CHILDREN(rack_counters), 1012 OID_AUTO, "tls_filled", CTLFLAG_RD, 1013 &rack_tls_filled, 1014 "Total hdwr tls filled"); 1015 1016 rack_tls_rxt = counter_u64_alloc(M_WAITOK); 1017 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 1018 SYSCTL_CHILDREN(rack_counters), 1019 OID_AUTO, "tls_rxt", CTLFLAG_RD, 1020 &rack_tls_rxt, 1021 "Total hdwr rxt"); 1022 1023 rack_tls_tlp = counter_u64_alloc(M_WAITOK); 1024 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 1025 SYSCTL_CHILDREN(rack_counters), 1026 OID_AUTO, "tls_tlp", CTLFLAG_RD, 1027 &rack_tls_tlp, 1028 "Total hdwr tls tlp"); 1029 rack_per_timer_hole = counter_u64_alloc(M_WAITOK); 1030 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 1031 SYSCTL_CHILDREN(rack_counters), 1032 OID_AUTO, "timer_hole", CTLFLAG_RD, 1033 &rack_per_timer_hole, 1034 "Total persists start in timer hole"); 1035 1036 COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK); 1037 SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root), 1038 OID_AUTO, "outsize", CTLFLAG_RD, 1039 rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes"); 1040 COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK); 1041 SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root), 1042 OID_AUTO, "opts", CTLFLAG_RD, 1043 rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats"); 1044 SYSCTL_ADD_PROC(&rack_sysctl_ctx, 1045 SYSCTL_CHILDREN(rack_sysctl_root), 1046 OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE, 1047 &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters"); 1048 } 1049 1050 static __inline int 1051 rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a) 1052 { 1053 if (SEQ_GEQ(b->r_start, a->r_start) && 1054 SEQ_LT(b->r_start, a->r_end)) { 1055 /* 1056 * The entry b is within the 1057 * block a. i.e.: 1058 * a -- |-------------| 1059 * b -- |----| 1060 * <or> 1061 * b -- |------| 1062 * <or> 1063 * b -- |-----------| 1064 */ 1065 return (0); 1066 } else if (SEQ_GEQ(b->r_start, a->r_end)) { 1067 /* 1068 * b falls as either the next 1069 * sequence block after a so a 1070 * is said to be smaller than b. 1071 * i.e: 1072 * a -- |------| 1073 * b -- |--------| 1074 * or 1075 * b -- |-----| 1076 */ 1077 return (1); 1078 } 1079 /* 1080 * Whats left is where a is 1081 * larger than b. i.e: 1082 * a -- |-------| 1083 * b -- |---| 1084 * or even possibly 1085 * b -- |--------------| 1086 */ 1087 return (-1); 1088 } 1089 1090 RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp); 1091 RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp); 1092 1093 static inline int32_t 1094 rack_progress_timeout_check(struct tcpcb *tp) 1095 { 1096 if (tp->t_maxunacktime && tp->t_acktime && TSTMP_GT(ticks, tp->t_acktime)) { 1097 if ((ticks - tp->t_acktime) >= tp->t_maxunacktime) { 1098 /* 1099 * There is an assumption that the caller 1100 * will drop the connection so we will 1101 * increment the counters here. 1102 */ 1103 struct tcp_rack *rack; 1104 rack = (struct tcp_rack *)tp->t_fb_ptr; 1105 counter_u64_add(rack_progress_drops, 1); 1106 #ifdef NETFLIX_STATS 1107 TCPSTAT_INC(tcps_progdrops); 1108 #endif 1109 rack_log_progress_event(rack, tp, ticks, PROGRESS_DROP, __LINE__); 1110 return (1); 1111 } 1112 } 1113 return (0); 1114 } 1115 1116 1117 1118 static void 1119 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod) 1120 { 1121 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1122 union tcp_log_stackspecific log; 1123 struct timeval tv; 1124 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1125 log.u_bbr.flex1 = tsused; 1126 log.u_bbr.flex2 = thresh; 1127 log.u_bbr.flex3 = rsm->r_flags; 1128 log.u_bbr.flex4 = rsm->r_dupack; 1129 log.u_bbr.flex5 = rsm->r_start; 1130 log.u_bbr.flex6 = rsm->r_end; 1131 log.u_bbr.flex8 = mod; 1132 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1133 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1134 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1135 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1136 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1137 &rack->rc_inp->inp_socket->so_rcv, 1138 &rack->rc_inp->inp_socket->so_snd, 1139 BBR_LOG_SETTINGS_CHG, 0, 1140 0, &log, false, &tv); 1141 } 1142 } 1143 1144 1145 1146 static void 1147 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which) 1148 { 1149 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1150 union tcp_log_stackspecific log; 1151 struct timeval tv; 1152 1153 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1154 log.u_bbr.flex1 = TICKS_2_MSEC(rack->rc_tp->t_srtt >> TCP_RTT_SHIFT); 1155 log.u_bbr.flex2 = to; 1156 log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags; 1157 log.u_bbr.flex4 = slot; 1158 log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot; 1159 log.u_bbr.flex6 = rack->rc_tp->t_rxtcur; 1160 log.u_bbr.flex7 = rack->rc_in_persist; 1161 log.u_bbr.flex8 = which; 1162 log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt; 1163 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1164 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1165 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1166 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1167 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1168 &rack->rc_inp->inp_socket->so_rcv, 1169 &rack->rc_inp->inp_socket->so_snd, 1170 BBR_LOG_TIMERSTAR, 0, 1171 0, &log, false, &tv); 1172 } 1173 } 1174 1175 static void 1176 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, int no) 1177 { 1178 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1179 union tcp_log_stackspecific log; 1180 struct timeval tv; 1181 1182 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1183 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1184 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1185 log.u_bbr.flex8 = to_num; 1186 log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt; 1187 log.u_bbr.flex2 = rack->rc_rack_rtt; 1188 log.u_bbr.flex3 = no; 1189 log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt; 1190 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1191 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1192 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1193 &rack->rc_inp->inp_socket->so_rcv, 1194 &rack->rc_inp->inp_socket->so_snd, 1195 BBR_LOG_RTO, 0, 1196 0, &log, false, &tv); 1197 } 1198 } 1199 1200 static void 1201 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, int32_t t, 1202 uint32_t o_srtt, uint32_t o_var) 1203 { 1204 if (tp->t_logstate != TCP_LOG_STATE_OFF) { 1205 union tcp_log_stackspecific log; 1206 struct timeval tv; 1207 1208 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1209 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1210 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1211 log.u_bbr.flex1 = t; 1212 log.u_bbr.flex2 = o_srtt; 1213 log.u_bbr.flex3 = o_var; 1214 log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest; 1215 log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest; 1216 log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_rtt_cnt; 1217 log.u_bbr.rttProp = rack->r_ctl.rack_rs.rs_rtt_tot; 1218 log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method; 1219 log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt; 1220 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1221 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1222 TCP_LOG_EVENTP(tp, NULL, 1223 &rack->rc_inp->inp_socket->so_rcv, 1224 &rack->rc_inp->inp_socket->so_snd, 1225 BBR_LOG_BBRRTT, 0, 1226 0, &log, false, &tv); 1227 } 1228 } 1229 1230 static void 1231 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt) 1232 { 1233 /* 1234 * Log the rtt sample we are 1235 * applying to the srtt algorithm in 1236 * useconds. 1237 */ 1238 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1239 union tcp_log_stackspecific log; 1240 struct timeval tv; 1241 1242 /* Convert our ms to a microsecond */ 1243 memset(&log, 0, sizeof(log)); 1244 log.u_bbr.flex1 = rtt * 1000; 1245 log.u_bbr.flex2 = rack->r_ctl.ack_count; 1246 log.u_bbr.flex3 = rack->r_ctl.sack_count; 1247 log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move; 1248 log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra; 1249 log.u_bbr.flex8 = rack->sack_attack_disable; 1250 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1251 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1252 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1253 &rack->rc_inp->inp_socket->so_rcv, 1254 &rack->rc_inp->inp_socket->so_snd, 1255 TCP_LOG_RTT, 0, 1256 0, &log, false, &tv); 1257 } 1258 } 1259 1260 1261 static inline void 1262 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick, int event, int line) 1263 { 1264 if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) { 1265 union tcp_log_stackspecific log; 1266 struct timeval tv; 1267 1268 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1269 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1270 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1271 log.u_bbr.flex1 = line; 1272 log.u_bbr.flex2 = tick; 1273 log.u_bbr.flex3 = tp->t_maxunacktime; 1274 log.u_bbr.flex4 = tp->t_acktime; 1275 log.u_bbr.flex8 = event; 1276 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1277 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1278 TCP_LOG_EVENTP(tp, NULL, 1279 &rack->rc_inp->inp_socket->so_rcv, 1280 &rack->rc_inp->inp_socket->so_snd, 1281 BBR_LOG_PROGRESS, 0, 1282 0, &log, false, &tv); 1283 } 1284 } 1285 1286 static void 1287 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts) 1288 { 1289 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1290 union tcp_log_stackspecific log; 1291 struct timeval tv; 1292 1293 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1294 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1295 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1296 log.u_bbr.flex1 = slot; 1297 log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt; 1298 log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags); 1299 log.u_bbr.flex8 = rack->rc_in_persist; 1300 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1301 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1302 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1303 &rack->rc_inp->inp_socket->so_rcv, 1304 &rack->rc_inp->inp_socket->so_snd, 1305 BBR_LOG_BBRSND, 0, 1306 0, &log, false, &tv); 1307 } 1308 } 1309 1310 static void 1311 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out) 1312 { 1313 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1314 union tcp_log_stackspecific log; 1315 struct timeval tv; 1316 1317 memset(&log, 0, sizeof(log)); 1318 log.u_bbr.flex1 = did_out; 1319 log.u_bbr.flex2 = nxt_pkt; 1320 log.u_bbr.flex3 = way_out; 1321 log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags; 1322 log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt; 1323 log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs; 1324 log.u_bbr.flex7 = rack->r_wanted_output; 1325 log.u_bbr.flex8 = rack->rc_in_persist; 1326 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1327 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1328 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1329 &rack->rc_inp->inp_socket->so_rcv, 1330 &rack->rc_inp->inp_socket->so_snd, 1331 BBR_LOG_DOSEG_DONE, 0, 1332 0, &log, false, &tv); 1333 } 1334 } 1335 1336 static void 1337 rack_log_type_hrdwtso(struct tcpcb *tp, struct tcp_rack *rack, int len, int mod, int32_t orig_len, int frm) 1338 { 1339 if (tp->t_logstate != TCP_LOG_STATE_OFF) { 1340 union tcp_log_stackspecific log; 1341 struct timeval tv; 1342 uint32_t cts; 1343 1344 memset(&log, 0, sizeof(log)); 1345 cts = tcp_get_usecs(&tv); 1346 log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs; 1347 log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs; 1348 log.u_bbr.flex4 = len; 1349 log.u_bbr.flex5 = orig_len; 1350 log.u_bbr.flex6 = rack->r_ctl.rc_sacked; 1351 log.u_bbr.flex7 = mod; 1352 log.u_bbr.flex8 = frm; 1353 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1354 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1355 TCP_LOG_EVENTP(tp, NULL, 1356 &tp->t_inpcb->inp_socket->so_rcv, 1357 &tp->t_inpcb->inp_socket->so_snd, 1358 TCP_HDWR_TLS, 0, 1359 0, &log, false, &tv); 1360 } 1361 } 1362 1363 static void 1364 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot, uint8_t hpts_calling) 1365 { 1366 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1367 union tcp_log_stackspecific log; 1368 struct timeval tv; 1369 1370 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1371 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1372 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1373 log.u_bbr.flex1 = slot; 1374 log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags; 1375 log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt; 1376 log.u_bbr.flex7 = hpts_calling; 1377 log.u_bbr.flex8 = rack->rc_in_persist; 1378 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1379 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1380 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1381 &rack->rc_inp->inp_socket->so_rcv, 1382 &rack->rc_inp->inp_socket->so_snd, 1383 BBR_LOG_JUSTRET, 0, 1384 tlen, &log, false, &tv); 1385 } 1386 } 1387 1388 static void 1389 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line) 1390 { 1391 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1392 union tcp_log_stackspecific log; 1393 struct timeval tv; 1394 1395 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1396 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1397 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1398 log.u_bbr.flex1 = line; 1399 log.u_bbr.flex2 = 0; 1400 log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags; 1401 log.u_bbr.flex4 = 0; 1402 log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt; 1403 log.u_bbr.flex6 = rack->rc_tp->t_rxtcur; 1404 log.u_bbr.flex8 = hpts_removed; 1405 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1406 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1407 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1408 &rack->rc_inp->inp_socket->so_rcv, 1409 &rack->rc_inp->inp_socket->so_snd, 1410 BBR_LOG_TIMERCANC, 0, 1411 0, &log, false, &tv); 1412 } 1413 } 1414 1415 static void 1416 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers) 1417 { 1418 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1419 union tcp_log_stackspecific log; 1420 struct timeval tv; 1421 1422 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1423 log.u_bbr.flex1 = timers; 1424 log.u_bbr.flex2 = ret; 1425 log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp; 1426 log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags; 1427 log.u_bbr.flex5 = cts; 1428 log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt; 1429 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1430 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1431 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1432 &rack->rc_inp->inp_socket->so_rcv, 1433 &rack->rc_inp->inp_socket->so_snd, 1434 BBR_LOG_TO_PROCESS, 0, 1435 0, &log, false, &tv); 1436 } 1437 } 1438 1439 static void 1440 rack_log_to_prr(struct tcp_rack *rack, int frm) 1441 { 1442 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1443 union tcp_log_stackspecific log; 1444 struct timeval tv; 1445 1446 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1447 log.u_bbr.flex1 = rack->r_ctl.rc_prr_out; 1448 log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs; 1449 log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt; 1450 log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered; 1451 log.u_bbr.flex5 = rack->r_ctl.rc_sacked; 1452 log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt; 1453 log.u_bbr.flex8 = frm; 1454 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1455 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1456 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1457 &rack->rc_inp->inp_socket->so_rcv, 1458 &rack->rc_inp->inp_socket->so_snd, 1459 BBR_LOG_BBRUPD, 0, 1460 0, &log, false, &tv); 1461 } 1462 } 1463 1464 #ifdef NETFLIX_EXP_DETECTION 1465 static void 1466 rack_log_sad(struct tcp_rack *rack, int event) 1467 { 1468 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1469 union tcp_log_stackspecific log; 1470 struct timeval tv; 1471 1472 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1473 log.u_bbr.flex1 = rack->r_ctl.sack_count; 1474 log.u_bbr.flex2 = rack->r_ctl.ack_count; 1475 log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra; 1476 log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move; 1477 log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced; 1478 log.u_bbr.flex6 = tcp_sack_to_ack_thresh; 1479 log.u_bbr.pkts_out = tcp_sack_to_move_thresh; 1480 log.u_bbr.lt_epoch = (tcp_force_detection << 8); 1481 log.u_bbr.lt_epoch |= rack->do_detection; 1482 log.u_bbr.applimited = tcp_map_minimum; 1483 log.u_bbr.flex7 = rack->sack_attack_disable; 1484 log.u_bbr.flex8 = event; 1485 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1486 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1487 log.u_bbr.delivered = tcp_sad_decay_val; 1488 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1489 &rack->rc_inp->inp_socket->so_rcv, 1490 &rack->rc_inp->inp_socket->so_snd, 1491 TCP_SAD_DETECTION, 0, 1492 0, &log, false, &tv); 1493 } 1494 } 1495 #endif 1496 1497 static void 1498 rack_counter_destroy(void) 1499 { 1500 counter_u64_free(rack_badfr); 1501 counter_u64_free(rack_badfr_bytes); 1502 counter_u64_free(rack_rtm_prr_retran); 1503 counter_u64_free(rack_rtm_prr_newdata); 1504 counter_u64_free(rack_timestamp_mismatch); 1505 counter_u64_free(rack_reorder_seen); 1506 counter_u64_free(rack_tlp_tot); 1507 counter_u64_free(rack_tlp_newdata); 1508 counter_u64_free(rack_tlp_retran); 1509 counter_u64_free(rack_tlp_retran_bytes); 1510 counter_u64_free(rack_tlp_retran_fail); 1511 counter_u64_free(rack_to_tot); 1512 counter_u64_free(rack_to_arm_rack); 1513 counter_u64_free(rack_to_arm_tlp); 1514 counter_u64_free(rack_paced_segments); 1515 counter_u64_free(rack_unpaced_segments); 1516 counter_u64_free(rack_saw_enobuf); 1517 counter_u64_free(rack_saw_enetunreach); 1518 counter_u64_free(rack_to_alloc_hard); 1519 counter_u64_free(rack_to_alloc_emerg); 1520 counter_u64_free(rack_sack_proc_all); 1521 counter_u64_free(rack_sack_proc_short); 1522 counter_u64_free(rack_sack_proc_restart); 1523 counter_u64_free(rack_to_alloc); 1524 counter_u64_free(rack_to_alloc_limited); 1525 counter_u64_free(rack_alloc_limited_conns); 1526 counter_u64_free(rack_split_limited); 1527 counter_u64_free(rack_find_high); 1528 counter_u64_free(rack_enter_tlp_calc); 1529 counter_u64_free(rack_used_tlpmethod); 1530 counter_u64_free(rack_used_tlpmethod2); 1531 counter_u64_free(rack_progress_drops); 1532 counter_u64_free(rack_input_idle_reduces); 1533 counter_u64_free(rack_collapsed_win); 1534 counter_u64_free(rack_tlp_does_nada); 1535 COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE); 1536 COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE); 1537 } 1538 1539 static struct rack_sendmap * 1540 rack_alloc(struct tcp_rack *rack) 1541 { 1542 struct rack_sendmap *rsm; 1543 1544 rsm = uma_zalloc(rack_zone, M_NOWAIT); 1545 if (rsm) { 1546 rack->r_ctl.rc_num_maps_alloced++; 1547 counter_u64_add(rack_to_alloc, 1); 1548 return (rsm); 1549 } 1550 if (rack->rc_free_cnt) { 1551 counter_u64_add(rack_to_alloc_emerg, 1); 1552 rsm = TAILQ_FIRST(&rack->r_ctl.rc_free); 1553 TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext); 1554 rack->rc_free_cnt--; 1555 return (rsm); 1556 } 1557 return (NULL); 1558 } 1559 1560 static struct rack_sendmap * 1561 rack_alloc_full_limit(struct tcp_rack *rack) 1562 { 1563 if ((V_tcp_map_entries_limit > 0) && 1564 (rack->do_detection == 0) && 1565 (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) { 1566 counter_u64_add(rack_to_alloc_limited, 1); 1567 if (!rack->alloc_limit_reported) { 1568 rack->alloc_limit_reported = 1; 1569 counter_u64_add(rack_alloc_limited_conns, 1); 1570 } 1571 return (NULL); 1572 } 1573 return (rack_alloc(rack)); 1574 } 1575 1576 /* wrapper to allocate a sendmap entry, subject to a specific limit */ 1577 static struct rack_sendmap * 1578 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type) 1579 { 1580 struct rack_sendmap *rsm; 1581 1582 if (limit_type) { 1583 /* currently there is only one limit type */ 1584 if (V_tcp_map_split_limit > 0 && 1585 (rack->do_detection == 0) && 1586 rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) { 1587 counter_u64_add(rack_split_limited, 1); 1588 if (!rack->alloc_limit_reported) { 1589 rack->alloc_limit_reported = 1; 1590 counter_u64_add(rack_alloc_limited_conns, 1); 1591 } 1592 return (NULL); 1593 } 1594 } 1595 1596 /* allocate and mark in the limit type, if set */ 1597 rsm = rack_alloc(rack); 1598 if (rsm != NULL && limit_type) { 1599 rsm->r_limit_type = limit_type; 1600 rack->r_ctl.rc_num_split_allocs++; 1601 } 1602 return (rsm); 1603 } 1604 1605 static void 1606 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm) 1607 { 1608 if (rsm->r_limit_type) { 1609 /* currently there is only one limit type */ 1610 rack->r_ctl.rc_num_split_allocs--; 1611 } 1612 if (rack->r_ctl.rc_tlpsend == rsm) 1613 rack->r_ctl.rc_tlpsend = NULL; 1614 if (rack->r_ctl.rc_sacklast == rsm) 1615 rack->r_ctl.rc_sacklast = NULL; 1616 if (rack->rc_free_cnt < rack_free_cache) { 1617 memset(rsm, 0, sizeof(struct rack_sendmap)); 1618 TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext); 1619 rsm->r_limit_type = 0; 1620 rack->rc_free_cnt++; 1621 return; 1622 } 1623 rack->r_ctl.rc_num_maps_alloced--; 1624 uma_zfree(rack_zone, rsm); 1625 } 1626 1627 /* 1628 * CC wrapper hook functions 1629 */ 1630 static void 1631 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, struct tcphdr *th, uint16_t nsegs, 1632 uint16_t type, int32_t recovery) 1633 { 1634 #ifdef STATS 1635 int32_t gput; 1636 #endif 1637 1638 INP_WLOCK_ASSERT(tp->t_inpcb); 1639 tp->ccv->nsegs = nsegs; 1640 tp->ccv->bytes_this_ack = BYTES_THIS_ACK(tp, th); 1641 if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) { 1642 uint32_t max; 1643 1644 max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp); 1645 if (tp->ccv->bytes_this_ack > max) { 1646 tp->ccv->bytes_this_ack = max; 1647 } 1648 } 1649 if ((!V_tcp_do_newcwv && (tp->snd_cwnd <= tp->snd_wnd)) || 1650 (V_tcp_do_newcwv && (tp->snd_cwnd <= tp->snd_wnd) && 1651 (tp->snd_cwnd < (ctf_flight_size(tp, rack->r_ctl.rc_sacked) * 2)))) 1652 tp->ccv->flags |= CCF_CWND_LIMITED; 1653 else 1654 tp->ccv->flags &= ~CCF_CWND_LIMITED; 1655 1656 if (type == CC_ACK) { 1657 #ifdef STATS 1658 stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF, 1659 ((int32_t) tp->snd_cwnd) - tp->snd_wnd); 1660 if ((tp->t_flags & TF_GPUTINPROG) && 1661 SEQ_GEQ(th->th_ack, tp->gput_ack)) { 1662 gput = (((int64_t) (th->th_ack - tp->gput_seq)) << 3) / 1663 max(1, tcp_ts_getticks() - tp->gput_ts); 1664 /* We store it in bytes per ms (or kbytes per sec) */ 1665 rack->r_ctl.rc_gp_history[rack->r_ctl.rc_gp_hist_idx] = gput / 8; 1666 rack->r_ctl.rc_gp_hist_idx++; 1667 if (rack->r_ctl.rc_gp_hist_idx >= RACK_GP_HIST) 1668 rack->r_ctl.rc_gp_hist_filled = 1; 1669 rack->r_ctl.rc_gp_hist_idx %= RACK_GP_HIST; 1670 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT, 1671 gput); 1672 /* 1673 * XXXLAS: This is a temporary hack, and should be 1674 * chained off VOI_TCP_GPUT when stats(9) grows an 1675 * API to deal with chained VOIs. 1676 */ 1677 if (tp->t_stats_gput_prev > 0) 1678 stats_voi_update_abs_s32(tp->t_stats, 1679 VOI_TCP_GPUT_ND, 1680 ((gput - tp->t_stats_gput_prev) * 100) / 1681 tp->t_stats_gput_prev); 1682 tp->t_flags &= ~TF_GPUTINPROG; 1683 tp->t_stats_gput_prev = gput; 1684 #ifdef NETFLIX_PEAKRATE 1685 if (tp->t_maxpeakrate) { 1686 /* 1687 * We update t_peakrate_thr. This gives us roughly 1688 * one update per round trip time. 1689 */ 1690 tcp_update_peakrate_thr(tp); 1691 } 1692 #endif 1693 } 1694 #endif 1695 if (tp->snd_cwnd > tp->snd_ssthresh) { 1696 tp->t_bytes_acked += min(tp->ccv->bytes_this_ack, 1697 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp)); 1698 if (tp->t_bytes_acked >= tp->snd_cwnd) { 1699 tp->t_bytes_acked -= tp->snd_cwnd; 1700 tp->ccv->flags |= CCF_ABC_SENTAWND; 1701 } 1702 } else { 1703 tp->ccv->flags &= ~CCF_ABC_SENTAWND; 1704 tp->t_bytes_acked = 0; 1705 } 1706 } 1707 if (CC_ALGO(tp)->ack_received != NULL) { 1708 /* XXXLAS: Find a way to live without this */ 1709 tp->ccv->curack = th->th_ack; 1710 CC_ALGO(tp)->ack_received(tp->ccv, type); 1711 } 1712 #ifdef STATS 1713 stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, tp->snd_cwnd); 1714 #endif 1715 if (rack->r_ctl.rc_rack_largest_cwnd < tp->snd_cwnd) { 1716 rack->r_ctl.rc_rack_largest_cwnd = tp->snd_cwnd; 1717 } 1718 /* we enforce max peak rate if it is set. */ 1719 if (tp->t_peakrate_thr && tp->snd_cwnd > tp->t_peakrate_thr) { 1720 tp->snd_cwnd = tp->t_peakrate_thr; 1721 } 1722 } 1723 1724 static void 1725 tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th) 1726 { 1727 struct tcp_rack *rack; 1728 1729 rack = (struct tcp_rack *)tp->t_fb_ptr; 1730 INP_WLOCK_ASSERT(tp->t_inpcb); 1731 if (rack->r_ctl.rc_prr_sndcnt > 0) 1732 rack->r_wanted_output++; 1733 } 1734 1735 static void 1736 rack_post_recovery(struct tcpcb *tp, struct tcphdr *th) 1737 { 1738 struct tcp_rack *rack; 1739 1740 INP_WLOCK_ASSERT(tp->t_inpcb); 1741 rack = (struct tcp_rack *)tp->t_fb_ptr; 1742 if (CC_ALGO(tp)->post_recovery != NULL) { 1743 tp->ccv->curack = th->th_ack; 1744 CC_ALGO(tp)->post_recovery(tp->ccv); 1745 } 1746 /* 1747 * Here we can in theory adjust cwnd to be based on the number of 1748 * losses in the window (rack->r_ctl.rc_loss_count). This is done 1749 * based on the rack_use_proportional flag. 1750 */ 1751 if (rack->r_ctl.rc_prop_reduce && rack->r_ctl.rc_prop_rate) { 1752 int32_t reduce; 1753 1754 reduce = (rack->r_ctl.rc_loss_count * rack->r_ctl.rc_prop_rate); 1755 if (reduce > 50) { 1756 reduce = 50; 1757 } 1758 tp->snd_cwnd -= ((reduce * tp->snd_cwnd) / 100); 1759 } else { 1760 if (tp->snd_cwnd > tp->snd_ssthresh) { 1761 /* Drop us down to the ssthresh (1/2 cwnd at loss) */ 1762 tp->snd_cwnd = tp->snd_ssthresh; 1763 } 1764 } 1765 if (rack->r_ctl.rc_prr_sndcnt > 0) { 1766 /* Suck the next prr cnt back into cwnd */ 1767 tp->snd_cwnd += rack->r_ctl.rc_prr_sndcnt; 1768 rack->r_ctl.rc_prr_sndcnt = 0; 1769 rack_log_to_prr(rack, 1); 1770 } 1771 tp->snd_recover = tp->snd_una; 1772 EXIT_RECOVERY(tp->t_flags); 1773 1774 1775 } 1776 1777 static void 1778 rack_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type) 1779 { 1780 struct tcp_rack *rack; 1781 1782 INP_WLOCK_ASSERT(tp->t_inpcb); 1783 1784 rack = (struct tcp_rack *)tp->t_fb_ptr; 1785 switch (type) { 1786 case CC_NDUPACK: 1787 tp->t_flags &= ~TF_WASFRECOVERY; 1788 tp->t_flags &= ~TF_WASCRECOVERY; 1789 if (!IN_FASTRECOVERY(tp->t_flags)) { 1790 rack->r_ctl.rc_tlp_rtx_out = 0; 1791 rack->r_ctl.rc_prr_delivered = 0; 1792 rack->r_ctl.rc_prr_out = 0; 1793 rack->r_ctl.rc_loss_count = 0; 1794 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 1795 rack_log_to_prr(rack, 2); 1796 rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una; 1797 tp->snd_recover = tp->snd_max; 1798 if (tp->t_flags2 & TF2_ECN_PERMIT) 1799 tp->t_flags2 |= TF2_ECN_SND_CWR; 1800 } 1801 break; 1802 case CC_ECN: 1803 if (!IN_CONGRECOVERY(tp->t_flags)) { 1804 TCPSTAT_INC(tcps_ecn_rcwnd); 1805 tp->snd_recover = tp->snd_max; 1806 if (tp->t_flags2 & TF2_ECN_PERMIT) 1807 tp->t_flags2 |= TF2_ECN_SND_CWR; 1808 } 1809 break; 1810 case CC_RTO: 1811 tp->t_dupacks = 0; 1812 tp->t_bytes_acked = 0; 1813 EXIT_RECOVERY(tp->t_flags); 1814 tp->snd_ssthresh = max(2, min(tp->snd_wnd, tp->snd_cwnd) / 2 / 1815 ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp); 1816 tp->snd_cwnd = ctf_fixed_maxseg(tp); 1817 if (tp->t_flags2 & TF2_ECN_PERMIT) 1818 tp->t_flags2 |= TF2_ECN_SND_CWR; 1819 break; 1820 case CC_RTO_ERR: 1821 TCPSTAT_INC(tcps_sndrexmitbad); 1822 /* RTO was unnecessary, so reset everything. */ 1823 tp->snd_cwnd = tp->snd_cwnd_prev; 1824 tp->snd_ssthresh = tp->snd_ssthresh_prev; 1825 tp->snd_recover = tp->snd_recover_prev; 1826 if (tp->t_flags & TF_WASFRECOVERY) { 1827 ENTER_FASTRECOVERY(tp->t_flags); 1828 tp->t_flags &= ~TF_WASFRECOVERY; 1829 } 1830 if (tp->t_flags & TF_WASCRECOVERY) { 1831 ENTER_CONGRECOVERY(tp->t_flags); 1832 tp->t_flags &= ~TF_WASCRECOVERY; 1833 } 1834 tp->snd_nxt = tp->snd_max; 1835 tp->t_badrxtwin = 0; 1836 break; 1837 } 1838 1839 if (CC_ALGO(tp)->cong_signal != NULL) { 1840 if (th != NULL) 1841 tp->ccv->curack = th->th_ack; 1842 CC_ALGO(tp)->cong_signal(tp->ccv, type); 1843 } 1844 } 1845 1846 1847 1848 static inline void 1849 rack_cc_after_idle(struct tcpcb *tp) 1850 { 1851 uint32_t i_cwnd; 1852 1853 INP_WLOCK_ASSERT(tp->t_inpcb); 1854 1855 #ifdef NETFLIX_STATS 1856 TCPSTAT_INC(tcps_idle_restarts); 1857 if (tp->t_state == TCPS_ESTABLISHED) 1858 TCPSTAT_INC(tcps_idle_estrestarts); 1859 #endif 1860 if (CC_ALGO(tp)->after_idle != NULL) 1861 CC_ALGO(tp)->after_idle(tp->ccv); 1862 1863 if (tp->snd_cwnd == 1) 1864 i_cwnd = tp->t_maxseg; /* SYN(-ACK) lost */ 1865 else 1866 i_cwnd = tcp_compute_initwnd(tcp_maxseg(tp)); 1867 1868 /* 1869 * Being idle is no differnt than the initial window. If the cc 1870 * clamps it down below the initial window raise it to the initial 1871 * window. 1872 */ 1873 if (tp->snd_cwnd < i_cwnd) { 1874 tp->snd_cwnd = i_cwnd; 1875 } 1876 } 1877 1878 1879 /* 1880 * Indicate whether this ack should be delayed. We can delay the ack if 1881 * following conditions are met: 1882 * - There is no delayed ack timer in progress. 1883 * - Our last ack wasn't a 0-sized window. We never want to delay 1884 * the ack that opens up a 0-sized window. 1885 * - LRO wasn't used for this segment. We make sure by checking that the 1886 * segment size is not larger than the MSS. 1887 * - Delayed acks are enabled or this is a half-synchronized T/TCP 1888 * connection. 1889 */ 1890 #define DELAY_ACK(tp, tlen) \ 1891 (((tp->t_flags & TF_RXWIN0SENT) == 0) && \ 1892 ((tp->t_flags & TF_DELACK) == 0) && \ 1893 (tlen <= tp->t_maxseg) && \ 1894 (tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN))) 1895 1896 static struct rack_sendmap * 1897 rack_find_lowest_rsm(struct tcp_rack *rack) 1898 { 1899 struct rack_sendmap *rsm; 1900 1901 /* 1902 * Walk the time-order transmitted list looking for an rsm that is 1903 * not acked. This will be the one that was sent the longest time 1904 * ago that is still outstanding. 1905 */ 1906 TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) { 1907 if (rsm->r_flags & RACK_ACKED) { 1908 continue; 1909 } 1910 goto finish; 1911 } 1912 finish: 1913 return (rsm); 1914 } 1915 1916 static struct rack_sendmap * 1917 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm) 1918 { 1919 struct rack_sendmap *prsm; 1920 1921 /* 1922 * Walk the sequence order list backward until we hit and arrive at 1923 * the highest seq not acked. In theory when this is called it 1924 * should be the last segment (which it was not). 1925 */ 1926 counter_u64_add(rack_find_high, 1); 1927 prsm = rsm; 1928 RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) { 1929 if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) { 1930 continue; 1931 } 1932 return (prsm); 1933 } 1934 return (NULL); 1935 } 1936 1937 1938 static uint32_t 1939 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts) 1940 { 1941 int32_t lro; 1942 uint32_t thresh; 1943 1944 /* 1945 * lro is the flag we use to determine if we have seen reordering. 1946 * If it gets set we have seen reordering. The reorder logic either 1947 * works in one of two ways: 1948 * 1949 * If reorder-fade is configured, then we track the last time we saw 1950 * re-ordering occur. If we reach the point where enough time as 1951 * passed we no longer consider reordering has occuring. 1952 * 1953 * Or if reorder-face is 0, then once we see reordering we consider 1954 * the connection to alway be subject to reordering and just set lro 1955 * to 1. 1956 * 1957 * In the end if lro is non-zero we add the extra time for 1958 * reordering in. 1959 */ 1960 if (srtt == 0) 1961 srtt = 1; 1962 if (rack->r_ctl.rc_reorder_ts) { 1963 if (rack->r_ctl.rc_reorder_fade) { 1964 if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) { 1965 lro = cts - rack->r_ctl.rc_reorder_ts; 1966 if (lro == 0) { 1967 /* 1968 * No time as passed since the last 1969 * reorder, mark it as reordering. 1970 */ 1971 lro = 1; 1972 } 1973 } else { 1974 /* Negative time? */ 1975 lro = 0; 1976 } 1977 if (lro > rack->r_ctl.rc_reorder_fade) { 1978 /* Turn off reordering seen too */ 1979 rack->r_ctl.rc_reorder_ts = 0; 1980 lro = 0; 1981 } 1982 } else { 1983 /* Reodering does not fade */ 1984 lro = 1; 1985 } 1986 } else { 1987 lro = 0; 1988 } 1989 thresh = srtt + rack->r_ctl.rc_pkt_delay; 1990 if (lro) { 1991 /* It must be set, if not you get 1/4 rtt */ 1992 if (rack->r_ctl.rc_reorder_shift) 1993 thresh += (srtt >> rack->r_ctl.rc_reorder_shift); 1994 else 1995 thresh += (srtt >> 2); 1996 } else { 1997 thresh += 1; 1998 } 1999 /* We don't let the rack timeout be above a RTO */ 2000 if (thresh > TICKS_2_MSEC(rack->rc_tp->t_rxtcur)) { 2001 thresh = TICKS_2_MSEC(rack->rc_tp->t_rxtcur); 2002 } 2003 /* And we don't want it above the RTO max either */ 2004 if (thresh > rack_rto_max) { 2005 thresh = rack_rto_max; 2006 } 2007 return (thresh); 2008 } 2009 2010 static uint32_t 2011 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack, 2012 struct rack_sendmap *rsm, uint32_t srtt) 2013 { 2014 struct rack_sendmap *prsm; 2015 uint32_t thresh, len; 2016 int maxseg; 2017 2018 if (srtt == 0) 2019 srtt = 1; 2020 if (rack->r_ctl.rc_tlp_threshold) 2021 thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold); 2022 else 2023 thresh = (srtt * 2); 2024 2025 /* Get the previous sent packet, if any */ 2026 maxseg = ctf_fixed_maxseg(tp); 2027 counter_u64_add(rack_enter_tlp_calc, 1); 2028 len = rsm->r_end - rsm->r_start; 2029 if (rack->rack_tlp_threshold_use == TLP_USE_ID) { 2030 /* Exactly like the ID */ 2031 if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= maxseg) { 2032 uint32_t alt_thresh; 2033 /* 2034 * Compensate for delayed-ack with the d-ack time. 2035 */ 2036 counter_u64_add(rack_used_tlpmethod, 1); 2037 alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time; 2038 if (alt_thresh > thresh) 2039 thresh = alt_thresh; 2040 } 2041 } else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) { 2042 /* 2.1 behavior */ 2043 prsm = TAILQ_PREV(rsm, rack_head, r_tnext); 2044 if (prsm && (len <= maxseg)) { 2045 /* 2046 * Two packets outstanding, thresh should be (2*srtt) + 2047 * possible inter-packet delay (if any). 2048 */ 2049 uint32_t inter_gap = 0; 2050 int idx, nidx; 2051 2052 counter_u64_add(rack_used_tlpmethod, 1); 2053 idx = rsm->r_rtr_cnt - 1; 2054 nidx = prsm->r_rtr_cnt - 1; 2055 if (TSTMP_GEQ(rsm->r_tim_lastsent[nidx], prsm->r_tim_lastsent[idx])) { 2056 /* Yes it was sent later (or at the same time) */ 2057 inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx]; 2058 } 2059 thresh += inter_gap; 2060 } else if (len <= maxseg) { 2061 /* 2062 * Possibly compensate for delayed-ack. 2063 */ 2064 uint32_t alt_thresh; 2065 2066 counter_u64_add(rack_used_tlpmethod2, 1); 2067 alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time; 2068 if (alt_thresh > thresh) 2069 thresh = alt_thresh; 2070 } 2071 } else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) { 2072 /* 2.2 behavior */ 2073 if (len <= maxseg) { 2074 uint32_t alt_thresh; 2075 /* 2076 * Compensate for delayed-ack with the d-ack time. 2077 */ 2078 counter_u64_add(rack_used_tlpmethod, 1); 2079 alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time; 2080 if (alt_thresh > thresh) 2081 thresh = alt_thresh; 2082 } 2083 } 2084 /* Not above an RTO */ 2085 if (thresh > TICKS_2_MSEC(tp->t_rxtcur)) { 2086 thresh = TICKS_2_MSEC(tp->t_rxtcur); 2087 } 2088 /* Not above a RTO max */ 2089 if (thresh > rack_rto_max) { 2090 thresh = rack_rto_max; 2091 } 2092 /* Apply user supplied min TLP */ 2093 if (thresh < rack_tlp_min) { 2094 thresh = rack_tlp_min; 2095 } 2096 return (thresh); 2097 } 2098 2099 static uint32_t 2100 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack) 2101 { 2102 /* 2103 * We want the rack_rtt which is the 2104 * last rtt we measured. However if that 2105 * does not exist we fallback to the srtt (which 2106 * we probably will never do) and then as a last 2107 * resort we use RACK_INITIAL_RTO if no srtt is 2108 * yet set. 2109 */ 2110 if (rack->rc_rack_rtt) 2111 return(rack->rc_rack_rtt); 2112 else if (tp->t_srtt == 0) 2113 return(RACK_INITIAL_RTO); 2114 return (TICKS_2_MSEC(tp->t_srtt >> TCP_RTT_SHIFT)); 2115 } 2116 2117 static struct rack_sendmap * 2118 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused) 2119 { 2120 /* 2121 * Check to see that we don't need to fall into recovery. We will 2122 * need to do so if our oldest transmit is past the time we should 2123 * have had an ack. 2124 */ 2125 struct tcp_rack *rack; 2126 struct rack_sendmap *rsm; 2127 int32_t idx; 2128 uint32_t srtt, thresh; 2129 2130 rack = (struct tcp_rack *)tp->t_fb_ptr; 2131 if (RB_EMPTY(&rack->r_ctl.rc_mtree)) { 2132 return (NULL); 2133 } 2134 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 2135 if (rsm == NULL) 2136 return (NULL); 2137 2138 if (rsm->r_flags & RACK_ACKED) { 2139 rsm = rack_find_lowest_rsm(rack); 2140 if (rsm == NULL) 2141 return (NULL); 2142 } 2143 idx = rsm->r_rtr_cnt - 1; 2144 srtt = rack_grab_rtt(tp, rack); 2145 thresh = rack_calc_thresh_rack(rack, srtt, tsused); 2146 if (tsused < rsm->r_tim_lastsent[idx]) { 2147 return (NULL); 2148 } 2149 if ((tsused - rsm->r_tim_lastsent[idx]) < thresh) { 2150 return (NULL); 2151 } 2152 /* Ok if we reach here we are over-due */ 2153 rack->r_ctl.rc_rsm_start = rsm->r_start; 2154 rack->r_ctl.rc_cwnd_at = tp->snd_cwnd; 2155 rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh; 2156 rack_cong_signal(tp, NULL, CC_NDUPACK); 2157 return (rsm); 2158 } 2159 2160 static uint32_t 2161 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack) 2162 { 2163 int32_t t; 2164 int32_t tt; 2165 uint32_t ret_val; 2166 2167 t = TICKS_2_MSEC((tp->t_srtt >> TCP_RTT_SHIFT) + ((tp->t_rttvar * 4) >> TCP_RTT_SHIFT)); 2168 TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift], 2169 rack_persist_min, rack_persist_max); 2170 if (tp->t_rxtshift < TCP_MAXRXTSHIFT) 2171 tp->t_rxtshift++; 2172 rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT; 2173 ret_val = (uint32_t)tt; 2174 return (ret_val); 2175 } 2176 2177 static uint32_t 2178 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack) 2179 { 2180 /* 2181 * Start the FR timer, we do this based on getting the first one in 2182 * the rc_tmap. Note that if its NULL we must stop the timer. in all 2183 * events we need to stop the running timer (if its running) before 2184 * starting the new one. 2185 */ 2186 uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse; 2187 uint32_t srtt_cur; 2188 int32_t idx; 2189 int32_t is_tlp_timer = 0; 2190 struct rack_sendmap *rsm; 2191 2192 if (rack->t_timers_stopped) { 2193 /* All timers have been stopped none are to run */ 2194 return (0); 2195 } 2196 if (rack->rc_in_persist) { 2197 /* We can't start any timer in persists */ 2198 return (rack_get_persists_timer_val(tp, rack)); 2199 } 2200 if ((tp->t_state < TCPS_ESTABLISHED) || 2201 ((tp->t_flags & TF_SACK_PERMIT) == 0)) 2202 goto activate_rxt; 2203 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 2204 if ((rsm == NULL) || sup_rack) { 2205 /* Nothing on the send map */ 2206 activate_rxt: 2207 time_since_sent = 0; 2208 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 2209 if (rsm) { 2210 idx = rsm->r_rtr_cnt - 1; 2211 if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], rack->r_ctl.rc_tlp_rxt_last_time)) 2212 tstmp_touse = rsm->r_tim_lastsent[idx]; 2213 else 2214 tstmp_touse = rack->r_ctl.rc_tlp_rxt_last_time; 2215 if (TSTMP_GT(tstmp_touse, cts)) 2216 time_since_sent = cts - tstmp_touse; 2217 } 2218 if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) { 2219 rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT; 2220 to = TICKS_2_MSEC(tp->t_rxtcur); 2221 if (to > time_since_sent) 2222 to -= time_since_sent; 2223 else 2224 to = rack->r_ctl.rc_min_to; 2225 if (to == 0) 2226 to = 1; 2227 return (to); 2228 } 2229 return (0); 2230 } 2231 if (rsm->r_flags & RACK_ACKED) { 2232 rsm = rack_find_lowest_rsm(rack); 2233 if (rsm == NULL) { 2234 /* No lowest? */ 2235 goto activate_rxt; 2236 } 2237 } 2238 if (rack->sack_attack_disable) { 2239 /* 2240 * We don't want to do 2241 * any TLP's if you are an attacker. 2242 * Though if you are doing what 2243 * is expected you may still have 2244 * SACK-PASSED marks. 2245 */ 2246 goto activate_rxt; 2247 } 2248 /* Convert from ms to usecs */ 2249 if (rsm->r_flags & RACK_SACK_PASSED) { 2250 if ((tp->t_flags & TF_SENTFIN) && 2251 ((tp->snd_max - tp->snd_una) == 1) && 2252 (rsm->r_flags & RACK_HAS_FIN)) { 2253 /* 2254 * We don't start a rack timer if all we have is a 2255 * FIN outstanding. 2256 */ 2257 goto activate_rxt; 2258 } 2259 if ((rack->use_rack_cheat == 0) && 2260 (IN_RECOVERY(tp->t_flags)) && 2261 (rack->r_ctl.rc_prr_sndcnt < ctf_fixed_maxseg(tp))) { 2262 /* 2263 * We are not cheating, in recovery and 2264 * not enough ack's to yet get our next 2265 * retransmission out. 2266 * 2267 * Note that classified attackers do not 2268 * get to use the rack-cheat. 2269 */ 2270 goto activate_tlp; 2271 } 2272 srtt = rack_grab_rtt(tp, rack); 2273 thresh = rack_calc_thresh_rack(rack, srtt, cts); 2274 idx = rsm->r_rtr_cnt - 1; 2275 exp = rsm->r_tim_lastsent[idx] + thresh; 2276 if (SEQ_GEQ(exp, cts)) { 2277 to = exp - cts; 2278 if (to < rack->r_ctl.rc_min_to) { 2279 to = rack->r_ctl.rc_min_to; 2280 } 2281 } else { 2282 to = rack->r_ctl.rc_min_to; 2283 } 2284 } else { 2285 /* Ok we need to do a TLP not RACK */ 2286 activate_tlp: 2287 if ((rack->rc_tlp_in_progress != 0) || 2288 (rack->r_ctl.rc_tlp_rtx_out != 0)) { 2289 /* 2290 * The previous send was a TLP or a tlp_rtx is in 2291 * process. 2292 */ 2293 goto activate_rxt; 2294 } 2295 rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext); 2296 if (rsm == NULL) { 2297 /* We found no rsm to TLP with. */ 2298 goto activate_rxt; 2299 } 2300 if (rsm->r_flags & RACK_HAS_FIN) { 2301 /* If its a FIN we dont do TLP */ 2302 rsm = NULL; 2303 goto activate_rxt; 2304 } 2305 idx = rsm->r_rtr_cnt - 1; 2306 time_since_sent = 0; 2307 if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], rack->r_ctl.rc_tlp_rxt_last_time)) 2308 tstmp_touse = rsm->r_tim_lastsent[idx]; 2309 else 2310 tstmp_touse = rack->r_ctl.rc_tlp_rxt_last_time; 2311 if (TSTMP_GT(tstmp_touse, cts)) 2312 time_since_sent = cts - tstmp_touse; 2313 is_tlp_timer = 1; 2314 if (tp->t_srtt) { 2315 srtt_cur = (tp->t_srtt >> TCP_RTT_SHIFT); 2316 srtt = TICKS_2_MSEC(srtt_cur); 2317 } else 2318 srtt = RACK_INITIAL_RTO; 2319 thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt); 2320 if (thresh > time_since_sent) 2321 to = thresh - time_since_sent; 2322 else 2323 to = rack->r_ctl.rc_min_to; 2324 if (to > TCPTV_REXMTMAX) { 2325 /* 2326 * If the TLP time works out to larger than the max 2327 * RTO lets not do TLP.. just RTO. 2328 */ 2329 goto activate_rxt; 2330 } 2331 if (rsm->r_start != rack->r_ctl.rc_last_tlp_seq) { 2332 /* 2333 * The tail is no longer the last one I did a probe 2334 * on 2335 */ 2336 rack->r_ctl.rc_tlp_seg_send_cnt = 0; 2337 rack->r_ctl.rc_last_tlp_seq = rsm->r_start; 2338 } 2339 } 2340 if (is_tlp_timer == 0) { 2341 rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK; 2342 } else { 2343 if ((rack->r_ctl.rc_tlp_send_cnt > rack_tlp_max_resend) || 2344 (rack->r_ctl.rc_tlp_seg_send_cnt > rack_tlp_max_resend)) { 2345 /* 2346 * We have exceeded how many times we can retran the 2347 * current TLP timer, switch to the RTO timer. 2348 */ 2349 goto activate_rxt; 2350 } else { 2351 rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP; 2352 } 2353 } 2354 if (to == 0) 2355 to = 1; 2356 return (to); 2357 } 2358 2359 static void 2360 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 2361 { 2362 if (rack->rc_in_persist == 0) { 2363 rack->r_ctl.rc_went_idle_time = cts; 2364 rack_timer_cancel(tp, rack, cts, __LINE__); 2365 tp->t_rxtshift = 0; 2366 rack->rc_in_persist = 1; 2367 } 2368 } 2369 2370 static void 2371 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack) 2372 { 2373 if (rack->rc_inp->inp_in_hpts) { 2374 tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT); 2375 rack->r_ctl.rc_hpts_flags = 0; 2376 } 2377 rack->rc_in_persist = 0; 2378 rack->r_ctl.rc_went_idle_time = 0; 2379 tp->t_flags &= ~TF_FORCEDATA; 2380 tp->t_rxtshift = 0; 2381 } 2382 2383 static void 2384 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts, 2385 int32_t slot, uint32_t tot_len_this_send, int sup_rack) 2386 { 2387 struct inpcb *inp; 2388 uint32_t delayed_ack = 0; 2389 uint32_t hpts_timeout; 2390 uint8_t stopped; 2391 uint32_t left = 0; 2392 2393 inp = tp->t_inpcb; 2394 if (inp->inp_in_hpts) { 2395 /* A previous call is already set up */ 2396 return; 2397 } 2398 if ((tp->t_state == TCPS_CLOSED) || 2399 (tp->t_state == TCPS_LISTEN)) { 2400 return; 2401 } 2402 stopped = rack->rc_tmr_stopped; 2403 if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) { 2404 left = rack->r_ctl.rc_timer_exp - cts; 2405 } 2406 rack->tlp_timer_up = 0; 2407 rack->r_ctl.rc_timer_exp = 0; 2408 if (rack->rc_inp->inp_in_hpts == 0) { 2409 rack->r_ctl.rc_hpts_flags = 0; 2410 } 2411 if (slot) { 2412 /* We are hptsi too */ 2413 rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT; 2414 } else if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) { 2415 /* 2416 * We are still left on the hpts when the to goes 2417 * it will be for output. 2418 */ 2419 if (TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) 2420 slot = rack->r_ctl.rc_last_output_to - cts; 2421 else 2422 slot = 1; 2423 } 2424 hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack); 2425 #ifdef NETFLIX_EXP_DETECTION 2426 if (rack->sack_attack_disable && 2427 (slot < USEC_TO_MSEC(tcp_sad_pacing_interval))) { 2428 /* 2429 * We have a potential attacker on 2430 * the line. We have possibly some 2431 * (or now) pacing time set. We want to 2432 * slow down the processing of sacks by some 2433 * amount (if it is an attacker). Set the default 2434 * slot for attackers in place (unless the orginal 2435 * interval is longer). Its stored in 2436 * micro-seconds, so lets convert to msecs. 2437 */ 2438 slot = USEC_TO_MSEC(tcp_sad_pacing_interval); 2439 } 2440 #endif 2441 if (tp->t_flags & TF_DELACK) { 2442 delayed_ack = TICKS_2_MSEC(tcp_delacktime); 2443 rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK; 2444 } 2445 if (delayed_ack && ((hpts_timeout == 0) || 2446 (delayed_ack < hpts_timeout))) 2447 hpts_timeout = delayed_ack; 2448 else 2449 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK; 2450 /* 2451 * If no timers are going to run and we will fall off the hptsi 2452 * wheel, we resort to a keep-alive timer if its configured. 2453 */ 2454 if ((hpts_timeout == 0) && 2455 (slot == 0)) { 2456 if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) && 2457 (tp->t_state <= TCPS_CLOSING)) { 2458 /* 2459 * Ok we have no timer (persists, rack, tlp, rxt or 2460 * del-ack), we don't have segments being paced. So 2461 * all that is left is the keepalive timer. 2462 */ 2463 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2464 /* Get the established keep-alive time */ 2465 hpts_timeout = TP_KEEPIDLE(tp); 2466 } else { 2467 /* Get the initial setup keep-alive time */ 2468 hpts_timeout = TP_KEEPINIT(tp); 2469 } 2470 rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP; 2471 } 2472 } 2473 if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) == 2474 (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) { 2475 /* 2476 * RACK, TLP, persists and RXT timers all are restartable 2477 * based on actions input .. i.e we received a packet (ack 2478 * or sack) and that changes things (rw, or snd_una etc). 2479 * Thus we can restart them with a new value. For 2480 * keep-alive, delayed_ack we keep track of what was left 2481 * and restart the timer with a smaller value. 2482 */ 2483 if (left < hpts_timeout) 2484 hpts_timeout = left; 2485 } 2486 if (hpts_timeout) { 2487 /* 2488 * Hack alert for now we can't time-out over 2,147,483 2489 * seconds (a bit more than 596 hours), which is probably ok 2490 * :). 2491 */ 2492 if (hpts_timeout > 0x7ffffffe) 2493 hpts_timeout = 0x7ffffffe; 2494 rack->r_ctl.rc_timer_exp = cts + hpts_timeout; 2495 } 2496 if (slot) { 2497 rack->rc_inp->inp_flags2 |= INP_MBUF_QUEUE_READY; 2498 if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) 2499 inp->inp_flags2 |= INP_DONT_SACK_QUEUE; 2500 else 2501 inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE; 2502 rack->r_ctl.rc_last_output_to = cts + slot; 2503 if ((hpts_timeout == 0) || (hpts_timeout > slot)) { 2504 if (rack->rc_inp->inp_in_hpts == 0) 2505 tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(slot)); 2506 rack_log_to_start(rack, cts, hpts_timeout, slot, 1); 2507 } else { 2508 /* 2509 * Arrange for the hpts to kick back in after the 2510 * t-o if the t-o does not cause a send. 2511 */ 2512 if (rack->rc_inp->inp_in_hpts == 0) 2513 tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout)); 2514 rack_log_to_start(rack, cts, hpts_timeout, slot, 0); 2515 } 2516 } else if (hpts_timeout) { 2517 if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) { 2518 /* For a rack timer, don't wake us */ 2519 rack->rc_inp->inp_flags2 |= INP_MBUF_QUEUE_READY; 2520 inp->inp_flags2 |= INP_DONT_SACK_QUEUE; 2521 } else { 2522 /* All other timers wake us up */ 2523 rack->rc_inp->inp_flags2 &= ~INP_MBUF_QUEUE_READY; 2524 inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE; 2525 } 2526 if (rack->rc_inp->inp_in_hpts == 0) 2527 tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout)); 2528 rack_log_to_start(rack, cts, hpts_timeout, slot, 0); 2529 } else { 2530 /* No timer starting */ 2531 #ifdef INVARIANTS 2532 if (SEQ_GT(tp->snd_max, tp->snd_una)) { 2533 panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?", 2534 tp, rack, tot_len_this_send, cts, slot, hpts_timeout); 2535 } 2536 #endif 2537 } 2538 rack->rc_tmr_stopped = 0; 2539 if (slot) 2540 rack_log_type_bbrsnd(rack, tot_len_this_send, slot, cts); 2541 } 2542 2543 /* 2544 * RACK Timer, here we simply do logging and house keeping. 2545 * the normal rack_output() function will call the 2546 * appropriate thing to check if we need to do a RACK retransmit. 2547 * We return 1, saying don't proceed with rack_output only 2548 * when all timers have been stopped (destroyed PCB?). 2549 */ 2550 static int 2551 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 2552 { 2553 /* 2554 * This timer simply provides an internal trigger to send out data. 2555 * The check_recovery_mode call will see if there are needed 2556 * retransmissions, if so we will enter fast-recovery. The output 2557 * call may or may not do the same thing depending on sysctl 2558 * settings. 2559 */ 2560 struct rack_sendmap *rsm; 2561 int32_t recovery, ll; 2562 2563 if (tp->t_timers->tt_flags & TT_STOPPED) { 2564 return (1); 2565 } 2566 if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) { 2567 /* Its not time yet */ 2568 return (0); 2569 } 2570 recovery = IN_RECOVERY(tp->t_flags); 2571 counter_u64_add(rack_to_tot, 1); 2572 if (rack->r_state && (rack->r_state != tp->t_state)) 2573 rack_set_state(tp, rack); 2574 rsm = rack_check_recovery_mode(tp, cts); 2575 if (rsm) 2576 ll = rsm->r_end - rsm->r_start; 2577 else 2578 ll = 0; 2579 rack_log_to_event(rack, RACK_TO_FRM_RACK, ll); 2580 if (rsm) { 2581 uint32_t rtt; 2582 2583 rtt = rack->rc_rack_rtt; 2584 if (rtt == 0) 2585 rtt = 1; 2586 if ((recovery == 0) && 2587 (rack->r_ctl.rc_prr_sndcnt < ctf_fixed_maxseg(tp))) { 2588 /* 2589 * The rack-timeout that enter's us into recovery 2590 * will force out one MSS and set us up so that we 2591 * can do one more send in 2*rtt (transitioning the 2592 * rack timeout into a rack-tlp). 2593 */ 2594 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 2595 rack_log_to_prr(rack, 3); 2596 } else if ((rack->r_ctl.rc_prr_sndcnt < (rsm->r_end - rsm->r_start)) && 2597 rack->use_rack_cheat) { 2598 /* 2599 * When a rack timer goes, if the rack cheat is 2600 * on, arrange it so we can send a full segment. 2601 */ 2602 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 2603 rack_log_to_prr(rack, 4); 2604 } 2605 } else { 2606 /* This is a case that should happen rarely if ever */ 2607 counter_u64_add(rack_tlp_does_nada, 1); 2608 #ifdef TCP_BLACKBOX 2609 tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true); 2610 #endif 2611 rack->r_ctl.rc_resend = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 2612 } 2613 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK; 2614 return (0); 2615 } 2616 2617 static __inline void 2618 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm, 2619 struct rack_sendmap *rsm, uint32_t start) 2620 { 2621 int idx; 2622 2623 nrsm->r_start = start; 2624 nrsm->r_end = rsm->r_end; 2625 nrsm->r_rtr_cnt = rsm->r_rtr_cnt; 2626 nrsm->r_flags = rsm->r_flags; 2627 nrsm->r_dupack = rsm->r_dupack; 2628 nrsm->r_rtr_bytes = 0; 2629 rsm->r_end = nrsm->r_start; 2630 for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) { 2631 nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx]; 2632 } 2633 } 2634 2635 static struct rack_sendmap * 2636 rack_merge_rsm(struct tcp_rack *rack, 2637 struct rack_sendmap *l_rsm, 2638 struct rack_sendmap *r_rsm) 2639 { 2640 /* 2641 * We are merging two ack'd RSM's, 2642 * the l_rsm is on the left (lower seq 2643 * values) and the r_rsm is on the right 2644 * (higher seq value). The simplest way 2645 * to merge these is to move the right 2646 * one into the left. I don't think there 2647 * is any reason we need to try to find 2648 * the oldest (or last oldest retransmitted). 2649 */ 2650 struct rack_sendmap *rm; 2651 2652 l_rsm->r_end = r_rsm->r_end; 2653 if (l_rsm->r_dupack < r_rsm->r_dupack) 2654 l_rsm->r_dupack = r_rsm->r_dupack; 2655 if (r_rsm->r_rtr_bytes) 2656 l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes; 2657 if (r_rsm->r_in_tmap) { 2658 /* This really should not happen */ 2659 TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext); 2660 r_rsm->r_in_tmap = 0; 2661 } 2662 /* Now the flags */ 2663 if (r_rsm->r_flags & RACK_HAS_FIN) 2664 l_rsm->r_flags |= RACK_HAS_FIN; 2665 if (r_rsm->r_flags & RACK_TLP) 2666 l_rsm->r_flags |= RACK_TLP; 2667 if (r_rsm->r_flags & RACK_RWND_COLLAPSED) 2668 l_rsm->r_flags |= RACK_RWND_COLLAPSED; 2669 rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm); 2670 #ifdef INVARIANTS 2671 if (rm != r_rsm) { 2672 panic("removing head in rack:%p rsm:%p rm:%p", 2673 rack, r_rsm, rm); 2674 } 2675 #endif 2676 if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) { 2677 /* Transfer the split limit to the map we free */ 2678 r_rsm->r_limit_type = l_rsm->r_limit_type; 2679 l_rsm->r_limit_type = 0; 2680 } 2681 rack_free(rack, r_rsm); 2682 return(l_rsm); 2683 } 2684 2685 /* 2686 * TLP Timer, here we simply setup what segment we want to 2687 * have the TLP expire on, the normal rack_output() will then 2688 * send it out. 2689 * 2690 * We return 1, saying don't proceed with rack_output only 2691 * when all timers have been stopped (destroyed PCB?). 2692 */ 2693 static int 2694 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 2695 { 2696 /* 2697 * Tail Loss Probe. 2698 */ 2699 struct rack_sendmap *rsm = NULL; 2700 struct rack_sendmap *insret; 2701 struct socket *so; 2702 uint32_t amm, old_prr_snd = 0; 2703 uint32_t out, avail; 2704 int collapsed_win = 0; 2705 2706 if (tp->t_timers->tt_flags & TT_STOPPED) { 2707 return (1); 2708 } 2709 if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) { 2710 /* Its not time yet */ 2711 return (0); 2712 } 2713 if (rack_progress_timeout_check(tp)) { 2714 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 2715 return (1); 2716 } 2717 /* 2718 * A TLP timer has expired. We have been idle for 2 rtts. So we now 2719 * need to figure out how to force a full MSS segment out. 2720 */ 2721 rack_log_to_event(rack, RACK_TO_FRM_TLP, 0); 2722 counter_u64_add(rack_tlp_tot, 1); 2723 if (rack->r_state && (rack->r_state != tp->t_state)) 2724 rack_set_state(tp, rack); 2725 so = tp->t_inpcb->inp_socket; 2726 #ifdef KERN_TLS 2727 if (rack->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) { 2728 /* 2729 * For hardware TLS we do *not* want to send 2730 * new data, lets instead just do a retransmission. 2731 */ 2732 goto need_retran; 2733 } 2734 #endif 2735 avail = sbavail(&so->so_snd); 2736 out = tp->snd_max - tp->snd_una; 2737 rack->tlp_timer_up = 1; 2738 if (out > tp->snd_wnd) { 2739 /* special case, we need a retransmission */ 2740 collapsed_win = 1; 2741 goto need_retran; 2742 } 2743 /* 2744 * If we are in recovery we can jazz out a segment if new data is 2745 * present simply by setting rc_prr_sndcnt to a segment. 2746 */ 2747 if ((avail > out) && 2748 ((rack_always_send_oldest == 0) || (TAILQ_EMPTY(&rack->r_ctl.rc_tmap)))) { 2749 /* New data is available */ 2750 amm = avail - out; 2751 if (amm > ctf_fixed_maxseg(tp)) { 2752 amm = ctf_fixed_maxseg(tp); 2753 } else if ((amm < ctf_fixed_maxseg(tp)) && ((tp->t_flags & TF_NODELAY) == 0)) { 2754 /* not enough to fill a MTU and no-delay is off */ 2755 goto need_retran; 2756 } 2757 if (IN_RECOVERY(tp->t_flags)) { 2758 /* Unlikely */ 2759 old_prr_snd = rack->r_ctl.rc_prr_sndcnt; 2760 if (out + amm <= tp->snd_wnd) { 2761 rack->r_ctl.rc_prr_sndcnt = amm; 2762 rack_log_to_prr(rack, 4); 2763 } else 2764 goto need_retran; 2765 } else { 2766 /* Set the send-new override */ 2767 if (out + amm <= tp->snd_wnd) 2768 rack->r_ctl.rc_tlp_new_data = amm; 2769 else 2770 goto need_retran; 2771 } 2772 rack->r_ctl.rc_tlp_seg_send_cnt = 0; 2773 rack->r_ctl.rc_last_tlp_seq = tp->snd_max; 2774 rack->r_ctl.rc_tlpsend = NULL; 2775 counter_u64_add(rack_tlp_newdata, 1); 2776 goto send; 2777 } 2778 need_retran: 2779 /* 2780 * Ok we need to arrange the last un-acked segment to be re-sent, or 2781 * optionally the first un-acked segment. 2782 */ 2783 if (collapsed_win == 0) { 2784 if (rack_always_send_oldest) 2785 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 2786 else { 2787 rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 2788 if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) { 2789 rsm = rack_find_high_nonack(rack, rsm); 2790 } 2791 } 2792 if (rsm == NULL) { 2793 counter_u64_add(rack_tlp_does_nada, 1); 2794 #ifdef TCP_BLACKBOX 2795 tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true); 2796 #endif 2797 goto out; 2798 } 2799 } else { 2800 /* 2801 * We must find the last segment 2802 * that was acceptable by the client. 2803 */ 2804 RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) { 2805 if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) { 2806 /* Found one */ 2807 break; 2808 } 2809 } 2810 if (rsm == NULL) { 2811 /* None? if so send the first */ 2812 rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 2813 if (rsm == NULL) { 2814 counter_u64_add(rack_tlp_does_nada, 1); 2815 #ifdef TCP_BLACKBOX 2816 tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true); 2817 #endif 2818 goto out; 2819 } 2820 } 2821 } 2822 if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) { 2823 /* 2824 * We need to split this the last segment in two. 2825 */ 2826 struct rack_sendmap *nrsm; 2827 2828 2829 nrsm = rack_alloc_full_limit(rack); 2830 if (nrsm == NULL) { 2831 /* 2832 * No memory to split, we will just exit and punt 2833 * off to the RXT timer. 2834 */ 2835 counter_u64_add(rack_tlp_does_nada, 1); 2836 goto out; 2837 } 2838 rack_clone_rsm(rack, nrsm, rsm, 2839 (rsm->r_end - ctf_fixed_maxseg(tp))); 2840 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 2841 #ifdef INVARIANTS 2842 if (insret != NULL) { 2843 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 2844 nrsm, insret, rack, rsm); 2845 } 2846 #endif 2847 if (rsm->r_in_tmap) { 2848 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 2849 nrsm->r_in_tmap = 1; 2850 } 2851 rsm->r_flags &= (~RACK_HAS_FIN); 2852 rsm = nrsm; 2853 } 2854 rack->r_ctl.rc_tlpsend = rsm; 2855 rack->r_ctl.rc_tlp_rtx_out = 1; 2856 if (rsm->r_start == rack->r_ctl.rc_last_tlp_seq) { 2857 rack->r_ctl.rc_tlp_seg_send_cnt++; 2858 tp->t_rxtshift++; 2859 } else { 2860 rack->r_ctl.rc_last_tlp_seq = rsm->r_start; 2861 rack->r_ctl.rc_tlp_seg_send_cnt = 1; 2862 } 2863 send: 2864 rack->r_ctl.rc_tlp_send_cnt++; 2865 if (rack->r_ctl.rc_tlp_send_cnt > rack_tlp_max_resend) { 2866 /* 2867 * Can't [re]/transmit a segment we have not heard from the 2868 * peer in max times. We need the retransmit timer to take 2869 * over. 2870 */ 2871 restore: 2872 rack->r_ctl.rc_tlpsend = NULL; 2873 if (rsm) 2874 rsm->r_flags &= ~RACK_TLP; 2875 rack->r_ctl.rc_prr_sndcnt = old_prr_snd; 2876 rack_log_to_prr(rack, 5); 2877 counter_u64_add(rack_tlp_retran_fail, 1); 2878 goto out; 2879 } else if (rsm) { 2880 rsm->r_flags |= RACK_TLP; 2881 } 2882 if (rsm && (rsm->r_start == rack->r_ctl.rc_last_tlp_seq) && 2883 (rack->r_ctl.rc_tlp_seg_send_cnt > rack_tlp_max_resend)) { 2884 /* 2885 * We don't want to send a single segment more than the max 2886 * either. 2887 */ 2888 goto restore; 2889 } 2890 rack->r_timer_override = 1; 2891 rack->r_tlp_running = 1; 2892 rack->rc_tlp_in_progress = 1; 2893 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP; 2894 return (0); 2895 out: 2896 rack->tlp_timer_up = 0; 2897 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP; 2898 return (0); 2899 } 2900 2901 /* 2902 * Delayed ack Timer, here we simply need to setup the 2903 * ACK_NOW flag and remove the DELACK flag. From there 2904 * the output routine will send the ack out. 2905 * 2906 * We only return 1, saying don't proceed, if all timers 2907 * are stopped (destroyed PCB?). 2908 */ 2909 static int 2910 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 2911 { 2912 if (tp->t_timers->tt_flags & TT_STOPPED) { 2913 return (1); 2914 } 2915 rack_log_to_event(rack, RACK_TO_FRM_DELACK, 0); 2916 tp->t_flags &= ~TF_DELACK; 2917 tp->t_flags |= TF_ACKNOW; 2918 TCPSTAT_INC(tcps_delack); 2919 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK; 2920 return (0); 2921 } 2922 2923 /* 2924 * Persists timer, here we simply need to setup the 2925 * FORCE-DATA flag the output routine will send 2926 * the one byte send. 2927 * 2928 * We only return 1, saying don't proceed, if all timers 2929 * are stopped (destroyed PCB?). 2930 */ 2931 static int 2932 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 2933 { 2934 struct tcptemp *t_template; 2935 struct inpcb *inp; 2936 int32_t retval = 1; 2937 2938 inp = tp->t_inpcb; 2939 2940 if (tp->t_timers->tt_flags & TT_STOPPED) { 2941 return (1); 2942 } 2943 if (rack->rc_in_persist == 0) 2944 return (0); 2945 if (rack_progress_timeout_check(tp)) { 2946 tcp_set_inp_to_drop(inp, ETIMEDOUT); 2947 return (1); 2948 } 2949 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp)); 2950 /* 2951 * Persistence timer into zero window. Force a byte to be output, if 2952 * possible. 2953 */ 2954 TCPSTAT_INC(tcps_persisttimeo); 2955 /* 2956 * Hack: if the peer is dead/unreachable, we do not time out if the 2957 * window is closed. After a full backoff, drop the connection if 2958 * the idle time (no responses to probes) reaches the maximum 2959 * backoff that we would use if retransmitting. 2960 */ 2961 if (tp->t_rxtshift == TCP_MAXRXTSHIFT && 2962 (ticks - tp->t_rcvtime >= tcp_maxpersistidle || 2963 ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) { 2964 TCPSTAT_INC(tcps_persistdrop); 2965 retval = 1; 2966 tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT); 2967 goto out; 2968 } 2969 if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) && 2970 tp->snd_una == tp->snd_max) 2971 rack_exit_persist(tp, rack); 2972 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT; 2973 /* 2974 * If the user has closed the socket then drop a persisting 2975 * connection after a much reduced timeout. 2976 */ 2977 if (tp->t_state > TCPS_CLOSE_WAIT && 2978 (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) { 2979 retval = 1; 2980 TCPSTAT_INC(tcps_persistdrop); 2981 tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT); 2982 goto out; 2983 } 2984 t_template = tcpip_maketemplate(rack->rc_inp); 2985 if (t_template) { 2986 tcp_respond(tp, t_template->tt_ipgen, 2987 &t_template->tt_t, (struct mbuf *)NULL, 2988 tp->rcv_nxt, tp->snd_una - 1, 0); 2989 /* This sends an ack */ 2990 if (tp->t_flags & TF_DELACK) 2991 tp->t_flags &= ~TF_DELACK; 2992 free(t_template, M_TEMP); 2993 } 2994 if (tp->t_rxtshift < TCP_MAXRXTSHIFT) 2995 tp->t_rxtshift++; 2996 out: 2997 rack_log_to_event(rack, RACK_TO_FRM_PERSIST, 0); 2998 rack_start_hpts_timer(rack, tp, cts, 2999 0, 0, 0); 3000 return (retval); 3001 } 3002 3003 /* 3004 * If a keepalive goes off, we had no other timers 3005 * happening. We always return 1 here since this 3006 * routine either drops the connection or sends 3007 * out a segment with respond. 3008 */ 3009 static int 3010 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 3011 { 3012 struct tcptemp *t_template; 3013 struct inpcb *inp; 3014 3015 if (tp->t_timers->tt_flags & TT_STOPPED) { 3016 return (1); 3017 } 3018 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP; 3019 inp = tp->t_inpcb; 3020 rack_log_to_event(rack, RACK_TO_FRM_KEEP, 0); 3021 /* 3022 * Keep-alive timer went off; send something or drop connection if 3023 * idle for too long. 3024 */ 3025 TCPSTAT_INC(tcps_keeptimeo); 3026 if (tp->t_state < TCPS_ESTABLISHED) 3027 goto dropit; 3028 if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) && 3029 tp->t_state <= TCPS_CLOSING) { 3030 if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp)) 3031 goto dropit; 3032 /* 3033 * Send a packet designed to force a response if the peer is 3034 * up and reachable: either an ACK if the connection is 3035 * still alive, or an RST if the peer has closed the 3036 * connection due to timeout or reboot. Using sequence 3037 * number tp->snd_una-1 causes the transmitted zero-length 3038 * segment to lie outside the receive window; by the 3039 * protocol spec, this requires the correspondent TCP to 3040 * respond. 3041 */ 3042 TCPSTAT_INC(tcps_keepprobe); 3043 t_template = tcpip_maketemplate(inp); 3044 if (t_template) { 3045 tcp_respond(tp, t_template->tt_ipgen, 3046 &t_template->tt_t, (struct mbuf *)NULL, 3047 tp->rcv_nxt, tp->snd_una - 1, 0); 3048 free(t_template, M_TEMP); 3049 } 3050 } 3051 rack_start_hpts_timer(rack, tp, cts, 0, 0, 0); 3052 return (1); 3053 dropit: 3054 TCPSTAT_INC(tcps_keepdrops); 3055 tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT); 3056 return (1); 3057 } 3058 3059 /* 3060 * Retransmit helper function, clear up all the ack 3061 * flags and take care of important book keeping. 3062 */ 3063 static void 3064 rack_remxt_tmr(struct tcpcb *tp) 3065 { 3066 /* 3067 * The retransmit timer went off, all sack'd blocks must be 3068 * un-acked. 3069 */ 3070 struct rack_sendmap *rsm, *trsm = NULL; 3071 struct tcp_rack *rack; 3072 int32_t cnt = 0; 3073 3074 rack = (struct tcp_rack *)tp->t_fb_ptr; 3075 rack_timer_cancel(tp, rack, tcp_ts_getticks(), __LINE__); 3076 rack_log_to_event(rack, RACK_TO_FRM_TMR, 0); 3077 if (rack->r_state && (rack->r_state != tp->t_state)) 3078 rack_set_state(tp, rack); 3079 /* 3080 * Ideally we would like to be able to 3081 * mark SACK-PASS on anything not acked here. 3082 * However, if we do that we would burst out 3083 * all that data 1ms apart. This would be unwise, 3084 * so for now we will just let the normal rxt timer 3085 * and tlp timer take care of it. 3086 */ 3087 RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) { 3088 if (rsm->r_flags & RACK_ACKED) { 3089 cnt++; 3090 rsm->r_dupack = 0; 3091 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 3092 if (rsm->r_in_tmap == 0) { 3093 /* We must re-add it back to the tlist */ 3094 if (trsm == NULL) { 3095 TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext); 3096 } else { 3097 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext); 3098 } 3099 rsm->r_in_tmap = 1; 3100 } 3101 } 3102 trsm = rsm; 3103 rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS); 3104 } 3105 /* Clear the count (we just un-acked them) */ 3106 rack->r_ctl.rc_sacked = 0; 3107 /* Clear the tlp rtx mark */ 3108 rack->r_ctl.rc_tlp_rtx_out = 0; 3109 rack->r_ctl.rc_tlp_seg_send_cnt = 0; 3110 rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 3111 rack->r_ctl.rc_prr_sndcnt = 0; 3112 rack_log_to_prr(rack, 6); 3113 rack->r_timer_override = 1; 3114 } 3115 3116 /* 3117 * Re-transmit timeout! If we drop the PCB we will return 1, otherwise 3118 * we will setup to retransmit the lowest seq number outstanding. 3119 */ 3120 static int 3121 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 3122 { 3123 int32_t rexmt; 3124 struct inpcb *inp; 3125 int32_t retval = 0; 3126 3127 inp = tp->t_inpcb; 3128 if (tp->t_timers->tt_flags & TT_STOPPED) { 3129 return (1); 3130 } 3131 if (rack_progress_timeout_check(tp)) { 3132 tcp_set_inp_to_drop(inp, ETIMEDOUT); 3133 return (1); 3134 } 3135 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT; 3136 if (TCPS_HAVEESTABLISHED(tp->t_state) && 3137 (tp->snd_una == tp->snd_max)) { 3138 /* Nothing outstanding .. nothing to do */ 3139 return (0); 3140 } 3141 /* 3142 * Retransmission timer went off. Message has not been acked within 3143 * retransmit interval. Back off to a longer retransmit interval 3144 * and retransmit one segment. 3145 */ 3146 rack_remxt_tmr(tp); 3147 if ((rack->r_ctl.rc_resend == NULL) || 3148 ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) { 3149 /* 3150 * If the rwnd collapsed on 3151 * the one we are retransmitting 3152 * it does not count against the 3153 * rxt count. 3154 */ 3155 tp->t_rxtshift++; 3156 } 3157 if (tp->t_rxtshift > TCP_MAXRXTSHIFT) { 3158 tp->t_rxtshift = TCP_MAXRXTSHIFT; 3159 TCPSTAT_INC(tcps_timeoutdrop); 3160 retval = 1; 3161 tcp_set_inp_to_drop(rack->rc_inp, 3162 (tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT)); 3163 goto out; 3164 } 3165 if (tp->t_state == TCPS_SYN_SENT) { 3166 /* 3167 * If the SYN was retransmitted, indicate CWND to be limited 3168 * to 1 segment in cc_conn_init(). 3169 */ 3170 tp->snd_cwnd = 1; 3171 } else if (tp->t_rxtshift == 1) { 3172 /* 3173 * first retransmit; record ssthresh and cwnd so they can be 3174 * recovered if this turns out to be a "bad" retransmit. A 3175 * retransmit is considered "bad" if an ACK for this segment 3176 * is received within RTT/2 interval; the assumption here is 3177 * that the ACK was already in flight. See "On Estimating 3178 * End-to-End Network Path Properties" by Allman and Paxson 3179 * for more details. 3180 */ 3181 tp->snd_cwnd_prev = tp->snd_cwnd; 3182 tp->snd_ssthresh_prev = tp->snd_ssthresh; 3183 tp->snd_recover_prev = tp->snd_recover; 3184 if (IN_FASTRECOVERY(tp->t_flags)) 3185 tp->t_flags |= TF_WASFRECOVERY; 3186 else 3187 tp->t_flags &= ~TF_WASFRECOVERY; 3188 if (IN_CONGRECOVERY(tp->t_flags)) 3189 tp->t_flags |= TF_WASCRECOVERY; 3190 else 3191 tp->t_flags &= ~TF_WASCRECOVERY; 3192 tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1)); 3193 tp->t_flags |= TF_PREVVALID; 3194 } else 3195 tp->t_flags &= ~TF_PREVVALID; 3196 TCPSTAT_INC(tcps_rexmttimeo); 3197 if ((tp->t_state == TCPS_SYN_SENT) || 3198 (tp->t_state == TCPS_SYN_RECEIVED)) 3199 rexmt = MSEC_2_TICKS(RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift]); 3200 else 3201 rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift]; 3202 TCPT_RANGESET(tp->t_rxtcur, rexmt, 3203 max(MSEC_2_TICKS(rack_rto_min), rexmt), 3204 MSEC_2_TICKS(rack_rto_max)); 3205 /* 3206 * We enter the path for PLMTUD if connection is established or, if 3207 * connection is FIN_WAIT_1 status, reason for the last is that if 3208 * amount of data we send is very small, we could send it in couple 3209 * of packets and process straight to FIN. In that case we won't 3210 * catch ESTABLISHED state. 3211 */ 3212 if (V_tcp_pmtud_blackhole_detect && (((tp->t_state == TCPS_ESTABLISHED)) 3213 || (tp->t_state == TCPS_FIN_WAIT_1))) { 3214 #ifdef INET6 3215 int32_t isipv6; 3216 #endif 3217 3218 /* 3219 * Idea here is that at each stage of mtu probe (usually, 3220 * 1448 -> 1188 -> 524) should be given 2 chances to recover 3221 * before further clamping down. 'tp->t_rxtshift % 2 == 0' 3222 * should take care of that. 3223 */ 3224 if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) == 3225 (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) && 3226 (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 && 3227 tp->t_rxtshift % 2 == 0)) { 3228 /* 3229 * Enter Path MTU Black-hole Detection mechanism: - 3230 * Disable Path MTU Discovery (IP "DF" bit). - 3231 * Reduce MTU to lower value than what we negotiated 3232 * with peer. 3233 */ 3234 if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) { 3235 /* Record that we may have found a black hole. */ 3236 tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE; 3237 /* Keep track of previous MSS. */ 3238 tp->t_pmtud_saved_maxseg = tp->t_maxseg; 3239 } 3240 3241 /* 3242 * Reduce the MSS to blackhole value or to the 3243 * default in an attempt to retransmit. 3244 */ 3245 #ifdef INET6 3246 isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? 1 : 0; 3247 if (isipv6 && 3248 tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) { 3249 /* Use the sysctl tuneable blackhole MSS. */ 3250 tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss; 3251 TCPSTAT_INC(tcps_pmtud_blackhole_activated); 3252 } else if (isipv6) { 3253 /* Use the default MSS. */ 3254 tp->t_maxseg = V_tcp_v6mssdflt; 3255 /* 3256 * Disable Path MTU Discovery when we switch 3257 * to minmss. 3258 */ 3259 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD; 3260 TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss); 3261 } 3262 #endif 3263 #if defined(INET6) && defined(INET) 3264 else 3265 #endif 3266 #ifdef INET 3267 if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) { 3268 /* Use the sysctl tuneable blackhole MSS. */ 3269 tp->t_maxseg = V_tcp_pmtud_blackhole_mss; 3270 TCPSTAT_INC(tcps_pmtud_blackhole_activated); 3271 } else { 3272 /* Use the default MSS. */ 3273 tp->t_maxseg = V_tcp_mssdflt; 3274 /* 3275 * Disable Path MTU Discovery when we switch 3276 * to minmss. 3277 */ 3278 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD; 3279 TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss); 3280 } 3281 #endif 3282 } else { 3283 /* 3284 * If further retransmissions are still unsuccessful 3285 * with a lowered MTU, maybe this isn't a blackhole 3286 * and we restore the previous MSS and blackhole 3287 * detection flags. The limit '6' is determined by 3288 * giving each probe stage (1448, 1188, 524) 2 3289 * chances to recover. 3290 */ 3291 if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) && 3292 (tp->t_rxtshift >= 6)) { 3293 tp->t_flags2 |= TF2_PLPMTU_PMTUD; 3294 tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE; 3295 tp->t_maxseg = tp->t_pmtud_saved_maxseg; 3296 TCPSTAT_INC(tcps_pmtud_blackhole_failed); 3297 } 3298 } 3299 } 3300 /* 3301 * If we backed off this far, our srtt estimate is probably bogus. 3302 * Clobber it so we'll take the next rtt measurement as our srtt; 3303 * move the current srtt into rttvar to keep the current retransmit 3304 * times until then. 3305 */ 3306 if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) { 3307 #ifdef INET6 3308 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) 3309 in6_losing(tp->t_inpcb); 3310 else 3311 #endif 3312 in_losing(tp->t_inpcb); 3313 tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT); 3314 tp->t_srtt = 0; 3315 } 3316 if (rack_use_sack_filter) 3317 sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una); 3318 tp->snd_recover = tp->snd_max; 3319 tp->t_flags |= TF_ACKNOW; 3320 tp->t_rtttime = 0; 3321 rack_cong_signal(tp, NULL, CC_RTO); 3322 out: 3323 return (retval); 3324 } 3325 3326 static int 3327 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling) 3328 { 3329 int32_t ret = 0; 3330 int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK); 3331 3332 if (timers == 0) { 3333 return (0); 3334 } 3335 if (tp->t_state == TCPS_LISTEN) { 3336 /* no timers on listen sockets */ 3337 if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) 3338 return (0); 3339 return (1); 3340 } 3341 if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) { 3342 uint32_t left; 3343 3344 if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) { 3345 ret = -1; 3346 rack_log_to_processing(rack, cts, ret, 0); 3347 return (0); 3348 } 3349 if (hpts_calling == 0) { 3350 ret = -2; 3351 rack_log_to_processing(rack, cts, ret, 0); 3352 return (0); 3353 } 3354 /* 3355 * Ok our timer went off early and we are not paced false 3356 * alarm, go back to sleep. 3357 */ 3358 ret = -3; 3359 left = rack->r_ctl.rc_timer_exp - cts; 3360 tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(left)); 3361 rack_log_to_processing(rack, cts, ret, left); 3362 rack->rc_last_pto_set = 0; 3363 return (1); 3364 } 3365 rack->rc_tmr_stopped = 0; 3366 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK; 3367 if (timers & PACE_TMR_DELACK) { 3368 ret = rack_timeout_delack(tp, rack, cts); 3369 } else if (timers & PACE_TMR_RACK) { 3370 rack->r_ctl.rc_tlp_rxt_last_time = cts; 3371 ret = rack_timeout_rack(tp, rack, cts); 3372 } else if (timers & PACE_TMR_TLP) { 3373 rack->r_ctl.rc_tlp_rxt_last_time = cts; 3374 ret = rack_timeout_tlp(tp, rack, cts); 3375 } else if (timers & PACE_TMR_RXT) { 3376 rack->r_ctl.rc_tlp_rxt_last_time = cts; 3377 ret = rack_timeout_rxt(tp, rack, cts); 3378 } else if (timers & PACE_TMR_PERSIT) { 3379 ret = rack_timeout_persist(tp, rack, cts); 3380 } else if (timers & PACE_TMR_KEEP) { 3381 ret = rack_timeout_keepalive(tp, rack, cts); 3382 } 3383 rack_log_to_processing(rack, cts, ret, timers); 3384 return (ret); 3385 } 3386 3387 static void 3388 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line) 3389 { 3390 uint8_t hpts_removed = 0; 3391 3392 if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) && 3393 TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) { 3394 tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT); 3395 hpts_removed = 1; 3396 } 3397 if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) { 3398 rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK; 3399 if (rack->rc_inp->inp_in_hpts && 3400 ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) { 3401 /* 3402 * Canceling timer's when we have no output being 3403 * paced. We also must remove ourselves from the 3404 * hpts. 3405 */ 3406 tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT); 3407 hpts_removed = 1; 3408 } 3409 rack_log_to_cancel(rack, hpts_removed, line); 3410 rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK); 3411 } 3412 } 3413 3414 static void 3415 rack_timer_stop(struct tcpcb *tp, uint32_t timer_type) 3416 { 3417 return; 3418 } 3419 3420 static int 3421 rack_stopall(struct tcpcb *tp) 3422 { 3423 struct tcp_rack *rack; 3424 rack = (struct tcp_rack *)tp->t_fb_ptr; 3425 rack->t_timers_stopped = 1; 3426 return (0); 3427 } 3428 3429 static void 3430 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta) 3431 { 3432 return; 3433 } 3434 3435 static int 3436 rack_timer_active(struct tcpcb *tp, uint32_t timer_type) 3437 { 3438 return (0); 3439 } 3440 3441 static void 3442 rack_stop_all_timers(struct tcpcb *tp) 3443 { 3444 struct tcp_rack *rack; 3445 3446 /* 3447 * Assure no timers are running. 3448 */ 3449 if (tcp_timer_active(tp, TT_PERSIST)) { 3450 /* We enter in persists, set the flag appropriately */ 3451 rack = (struct tcp_rack *)tp->t_fb_ptr; 3452 rack->rc_in_persist = 1; 3453 } 3454 tcp_timer_suspend(tp, TT_PERSIST); 3455 tcp_timer_suspend(tp, TT_REXMT); 3456 tcp_timer_suspend(tp, TT_KEEP); 3457 tcp_timer_suspend(tp, TT_DELACK); 3458 } 3459 3460 static void 3461 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack, 3462 struct rack_sendmap *rsm, uint32_t ts) 3463 { 3464 int32_t idx; 3465 3466 rsm->r_rtr_cnt++; 3467 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 3468 rsm->r_dupack = 0; 3469 if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) { 3470 rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS; 3471 rsm->r_flags |= RACK_OVERMAX; 3472 } 3473 if ((rsm->r_rtr_cnt > 1) && (rack->r_tlp_running == 0)) { 3474 rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start); 3475 rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start); 3476 } 3477 idx = rsm->r_rtr_cnt - 1; 3478 rsm->r_tim_lastsent[idx] = ts; 3479 if (rsm->r_flags & RACK_ACKED) { 3480 /* Problably MTU discovery messing with us */ 3481 rsm->r_flags &= ~RACK_ACKED; 3482 rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start); 3483 } 3484 if (rsm->r_in_tmap) { 3485 TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext); 3486 rsm->r_in_tmap = 0; 3487 } 3488 TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext); 3489 rsm->r_in_tmap = 1; 3490 if (rsm->r_flags & RACK_SACK_PASSED) { 3491 /* We have retransmitted due to the SACK pass */ 3492 rsm->r_flags &= ~RACK_SACK_PASSED; 3493 rsm->r_flags |= RACK_WAS_SACKPASS; 3494 } 3495 } 3496 3497 3498 static uint32_t 3499 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack, 3500 struct rack_sendmap *rsm, uint32_t ts, int32_t *lenp) 3501 { 3502 /* 3503 * We (re-)transmitted starting at rsm->r_start for some length 3504 * (possibly less than r_end. 3505 */ 3506 struct rack_sendmap *nrsm, *insret; 3507 uint32_t c_end; 3508 int32_t len; 3509 3510 len = *lenp; 3511 c_end = rsm->r_start + len; 3512 if (SEQ_GEQ(c_end, rsm->r_end)) { 3513 /* 3514 * We retransmitted the whole piece or more than the whole 3515 * slopping into the next rsm. 3516 */ 3517 rack_update_rsm(tp, rack, rsm, ts); 3518 if (c_end == rsm->r_end) { 3519 *lenp = 0; 3520 return (0); 3521 } else { 3522 int32_t act_len; 3523 3524 /* Hangs over the end return whats left */ 3525 act_len = rsm->r_end - rsm->r_start; 3526 *lenp = (len - act_len); 3527 return (rsm->r_end); 3528 } 3529 /* We don't get out of this block. */ 3530 } 3531 /* 3532 * Here we retransmitted less than the whole thing which means we 3533 * have to split this into what was transmitted and what was not. 3534 */ 3535 nrsm = rack_alloc_full_limit(rack); 3536 if (nrsm == NULL) { 3537 /* 3538 * We can't get memory, so lets not proceed. 3539 */ 3540 *lenp = 0; 3541 return (0); 3542 } 3543 /* 3544 * So here we are going to take the original rsm and make it what we 3545 * retransmitted. nrsm will be the tail portion we did not 3546 * retransmit. For example say the chunk was 1, 11 (10 bytes). And 3547 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to 3548 * 1, 6 and the new piece will be 6, 11. 3549 */ 3550 rack_clone_rsm(rack, nrsm, rsm, c_end); 3551 nrsm->r_dupack = 0; 3552 rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2); 3553 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 3554 #ifdef INVARIANTS 3555 if (insret != NULL) { 3556 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 3557 nrsm, insret, rack, rsm); 3558 } 3559 #endif 3560 if (rsm->r_in_tmap) { 3561 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 3562 nrsm->r_in_tmap = 1; 3563 } 3564 rsm->r_flags &= (~RACK_HAS_FIN); 3565 rack_update_rsm(tp, rack, rsm, ts); 3566 *lenp = 0; 3567 return (0); 3568 } 3569 3570 3571 static void 3572 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len, 3573 uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t ts, 3574 uint8_t pass, struct rack_sendmap *hintrsm) 3575 { 3576 struct tcp_rack *rack; 3577 struct rack_sendmap *rsm, *nrsm, *insret, fe; 3578 register uint32_t snd_max, snd_una; 3579 3580 /* 3581 * Add to the RACK log of packets in flight or retransmitted. If 3582 * there is a TS option we will use the TS echoed, if not we will 3583 * grab a TS. 3584 * 3585 * Retransmissions will increment the count and move the ts to its 3586 * proper place. Note that if options do not include TS's then we 3587 * won't be able to effectively use the ACK for an RTT on a retran. 3588 * 3589 * Notes about r_start and r_end. Lets consider a send starting at 3590 * sequence 1 for 10 bytes. In such an example the r_start would be 3591 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11. 3592 * This means that r_end is actually the first sequence for the next 3593 * slot (11). 3594 * 3595 */ 3596 /* 3597 * If err is set what do we do XXXrrs? should we not add the thing? 3598 * -- i.e. return if err != 0 or should we pretend we sent it? -- 3599 * i.e. proceed with add ** do this for now. 3600 */ 3601 INP_WLOCK_ASSERT(tp->t_inpcb); 3602 if (err) 3603 /* 3604 * We don't log errors -- we could but snd_max does not 3605 * advance in this case either. 3606 */ 3607 return; 3608 3609 if (th_flags & TH_RST) { 3610 /* 3611 * We don't log resets and we return immediately from 3612 * sending 3613 */ 3614 return; 3615 } 3616 rack = (struct tcp_rack *)tp->t_fb_ptr; 3617 snd_una = tp->snd_una; 3618 if (SEQ_LEQ((seq_out + len), snd_una)) { 3619 /* Are sending an old segment to induce an ack (keep-alive)? */ 3620 return; 3621 } 3622 if (SEQ_LT(seq_out, snd_una)) { 3623 /* huh? should we panic? */ 3624 uint32_t end; 3625 3626 end = seq_out + len; 3627 seq_out = snd_una; 3628 if (SEQ_GEQ(end, seq_out)) 3629 len = end - seq_out; 3630 else 3631 len = 0; 3632 } 3633 snd_max = tp->snd_max; 3634 if (th_flags & (TH_SYN | TH_FIN)) { 3635 /* 3636 * The call to rack_log_output is made before bumping 3637 * snd_max. This means we can record one extra byte on a SYN 3638 * or FIN if seq_out is adding more on and a FIN is present 3639 * (and we are not resending). 3640 */ 3641 if (th_flags & TH_SYN) 3642 len++; 3643 if (th_flags & TH_FIN) 3644 len++; 3645 if (SEQ_LT(snd_max, tp->snd_nxt)) { 3646 /* 3647 * The add/update as not been done for the FIN/SYN 3648 * yet. 3649 */ 3650 snd_max = tp->snd_nxt; 3651 } 3652 } 3653 if (len == 0) { 3654 /* We don't log zero window probes */ 3655 return; 3656 } 3657 rack->r_ctl.rc_time_last_sent = ts; 3658 if (IN_RECOVERY(tp->t_flags)) { 3659 rack->r_ctl.rc_prr_out += len; 3660 } 3661 /* First question is it a retransmission or new? */ 3662 if (seq_out == snd_max) { 3663 /* Its new */ 3664 again: 3665 rsm = rack_alloc(rack); 3666 if (rsm == NULL) { 3667 /* 3668 * Hmm out of memory and the tcb got destroyed while 3669 * we tried to wait. 3670 */ 3671 return; 3672 } 3673 if (th_flags & TH_FIN) { 3674 rsm->r_flags = RACK_HAS_FIN; 3675 } else { 3676 rsm->r_flags = 0; 3677 } 3678 rsm->r_tim_lastsent[0] = ts; 3679 rsm->r_rtr_cnt = 1; 3680 rsm->r_rtr_bytes = 0; 3681 if (th_flags & TH_SYN) { 3682 /* The data space is one beyond snd_una */ 3683 rsm->r_start = seq_out + 1; 3684 rsm->r_end = rsm->r_start + (len - 1); 3685 } else { 3686 /* Normal case */ 3687 rsm->r_start = seq_out; 3688 rsm->r_end = rsm->r_start + len; 3689 } 3690 rsm->r_dupack = 0; 3691 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 3692 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 3693 #ifdef INVARIANTS 3694 if (insret != NULL) { 3695 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 3696 nrsm, insret, rack, rsm); 3697 } 3698 #endif 3699 TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext); 3700 rsm->r_in_tmap = 1; 3701 return; 3702 } 3703 /* 3704 * If we reach here its a retransmission and we need to find it. 3705 */ 3706 memset(&fe, 0, sizeof(fe)); 3707 more: 3708 if (hintrsm && (hintrsm->r_start == seq_out)) { 3709 rsm = hintrsm; 3710 hintrsm = NULL; 3711 } else { 3712 /* No hints sorry */ 3713 rsm = NULL; 3714 } 3715 if ((rsm) && (rsm->r_start == seq_out)) { 3716 seq_out = rack_update_entry(tp, rack, rsm, ts, &len); 3717 if (len == 0) { 3718 return; 3719 } else { 3720 goto more; 3721 } 3722 } 3723 /* Ok it was not the last pointer go through it the hard way. */ 3724 refind: 3725 fe.r_start = seq_out; 3726 rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe); 3727 if (rsm) { 3728 if (rsm->r_start == seq_out) { 3729 seq_out = rack_update_entry(tp, rack, rsm, ts, &len); 3730 if (len == 0) { 3731 return; 3732 } else { 3733 goto refind; 3734 } 3735 } 3736 if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) { 3737 /* Transmitted within this piece */ 3738 /* 3739 * Ok we must split off the front and then let the 3740 * update do the rest 3741 */ 3742 nrsm = rack_alloc_full_limit(rack); 3743 if (nrsm == NULL) { 3744 rack_update_rsm(tp, rack, rsm, ts); 3745 return; 3746 } 3747 /* 3748 * copy rsm to nrsm and then trim the front of rsm 3749 * to not include this part. 3750 */ 3751 rack_clone_rsm(rack, nrsm, rsm, seq_out); 3752 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 3753 #ifdef INVARIANTS 3754 if (insret != NULL) { 3755 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 3756 nrsm, insret, rack, rsm); 3757 } 3758 #endif 3759 if (rsm->r_in_tmap) { 3760 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 3761 nrsm->r_in_tmap = 1; 3762 } 3763 rsm->r_flags &= (~RACK_HAS_FIN); 3764 seq_out = rack_update_entry(tp, rack, nrsm, ts, &len); 3765 if (len == 0) { 3766 return; 3767 } else if (len > 0) 3768 goto refind; 3769 } 3770 } 3771 /* 3772 * Hmm not found in map did they retransmit both old and on into the 3773 * new? 3774 */ 3775 if (seq_out == tp->snd_max) { 3776 goto again; 3777 } else if (SEQ_LT(seq_out, tp->snd_max)) { 3778 #ifdef INVARIANTS 3779 printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n", 3780 seq_out, len, tp->snd_una, tp->snd_max); 3781 printf("Starting Dump of all rack entries\n"); 3782 RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) { 3783 printf("rsm:%p start:%u end:%u\n", 3784 rsm, rsm->r_start, rsm->r_end); 3785 } 3786 printf("Dump complete\n"); 3787 panic("seq_out not found rack:%p tp:%p", 3788 rack, tp); 3789 #endif 3790 } else { 3791 #ifdef INVARIANTS 3792 /* 3793 * Hmm beyond sndmax? (only if we are using the new rtt-pack 3794 * flag) 3795 */ 3796 panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p", 3797 seq_out, len, tp->snd_max, tp); 3798 #endif 3799 } 3800 } 3801 3802 /* 3803 * Record one of the RTT updates from an ack into 3804 * our sample structure. 3805 */ 3806 static void 3807 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt) 3808 { 3809 if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) || 3810 (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) { 3811 rack->r_ctl.rack_rs.rs_rtt_lowest = rtt; 3812 } 3813 if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) || 3814 (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) { 3815 rack->r_ctl.rack_rs.rs_rtt_highest = rtt; 3816 } 3817 rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID; 3818 rack->r_ctl.rack_rs.rs_rtt_tot += rtt; 3819 rack->r_ctl.rack_rs.rs_rtt_cnt++; 3820 } 3821 3822 /* 3823 * Collect new round-trip time estimate 3824 * and update averages and current timeout. 3825 */ 3826 static void 3827 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp) 3828 { 3829 int32_t delta; 3830 uint32_t o_srtt, o_var; 3831 int32_t rtt; 3832 3833 if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) 3834 /* No valid sample */ 3835 return; 3836 if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) { 3837 /* We are to use the lowest RTT seen in a single ack */ 3838 rtt = rack->r_ctl.rack_rs.rs_rtt_lowest; 3839 } else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) { 3840 /* We are to use the highest RTT seen in a single ack */ 3841 rtt = rack->r_ctl.rack_rs.rs_rtt_highest; 3842 } else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) { 3843 /* We are to use the average RTT seen in a single ack */ 3844 rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot / 3845 (uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt); 3846 } else { 3847 #ifdef INVARIANTS 3848 panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method); 3849 #endif 3850 return; 3851 } 3852 if (rtt == 0) 3853 rtt = 1; 3854 rack_log_rtt_sample(rack, rtt); 3855 o_srtt = tp->t_srtt; 3856 o_var = tp->t_rttvar; 3857 rack = (struct tcp_rack *)tp->t_fb_ptr; 3858 if (tp->t_srtt != 0) { 3859 /* 3860 * srtt is stored as fixed point with 5 bits after the 3861 * binary point (i.e., scaled by 8). The following magic is 3862 * equivalent to the smoothing algorithm in rfc793 with an 3863 * alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed point). 3864 * Adjust rtt to origin 0. 3865 */ 3866 delta = ((rtt - 1) << TCP_DELTA_SHIFT) 3867 - (tp->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)); 3868 3869 tp->t_srtt += delta; 3870 if (tp->t_srtt <= 0) 3871 tp->t_srtt = 1; 3872 3873 /* 3874 * We accumulate a smoothed rtt variance (actually, a 3875 * smoothed mean difference), then set the retransmit timer 3876 * to smoothed rtt + 4 times the smoothed variance. rttvar 3877 * is stored as fixed point with 4 bits after the binary 3878 * point (scaled by 16). The following is equivalent to 3879 * rfc793 smoothing with an alpha of .75 (rttvar = 3880 * rttvar*3/4 + |delta| / 4). This replaces rfc793's 3881 * wired-in beta. 3882 */ 3883 if (delta < 0) 3884 delta = -delta; 3885 delta -= tp->t_rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT); 3886 tp->t_rttvar += delta; 3887 if (tp->t_rttvar <= 0) 3888 tp->t_rttvar = 1; 3889 if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar) 3890 tp->t_rttbest = tp->t_srtt + tp->t_rttvar; 3891 } else { 3892 /* 3893 * No rtt measurement yet - use the unsmoothed rtt. Set the 3894 * variance to half the rtt (so our first retransmit happens 3895 * at 3*rtt). 3896 */ 3897 tp->t_srtt = rtt << TCP_RTT_SHIFT; 3898 tp->t_rttvar = rtt << (TCP_RTTVAR_SHIFT - 1); 3899 tp->t_rttbest = tp->t_srtt + tp->t_rttvar; 3900 } 3901 TCPSTAT_INC(tcps_rttupdated); 3902 rack_log_rtt_upd(tp, rack, rtt, o_srtt, o_var); 3903 tp->t_rttupdated++; 3904 #ifdef STATS 3905 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt)); 3906 #endif 3907 tp->t_rxtshift = 0; 3908 3909 /* 3910 * the retransmit should happen at rtt + 4 * rttvar. Because of the 3911 * way we do the smoothing, srtt and rttvar will each average +1/2 3912 * tick of bias. When we compute the retransmit timer, we want 1/2 3913 * tick of rounding and 1 extra tick because of +-1/2 tick 3914 * uncertainty in the firing of the timer. The bias will give us 3915 * exactly the 1.5 tick we need. But, because the bias is 3916 * statistical, we have to test that we don't drop below the minimum 3917 * feasible timer (which is 2 ticks). 3918 */ 3919 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), 3920 max(MSEC_2_TICKS(rack_rto_min), rtt + 2), MSEC_2_TICKS(rack_rto_max)); 3921 tp->t_softerror = 0; 3922 } 3923 3924 static void 3925 rack_earlier_retran(struct tcpcb *tp, struct rack_sendmap *rsm, 3926 uint32_t t, uint32_t cts) 3927 { 3928 /* 3929 * For this RSM, we acknowledged the data from a previous 3930 * transmission, not the last one we made. This means we did a false 3931 * retransmit. 3932 */ 3933 struct tcp_rack *rack; 3934 3935 if (rsm->r_flags & RACK_HAS_FIN) { 3936 /* 3937 * The sending of the FIN often is multiple sent when we 3938 * have everything outstanding ack'd. We ignore this case 3939 * since its over now. 3940 */ 3941 return; 3942 } 3943 if (rsm->r_flags & RACK_TLP) { 3944 /* 3945 * We expect TLP's to have this occur. 3946 */ 3947 return; 3948 } 3949 rack = (struct tcp_rack *)tp->t_fb_ptr; 3950 /* should we undo cc changes and exit recovery? */ 3951 if (IN_RECOVERY(tp->t_flags)) { 3952 if (rack->r_ctl.rc_rsm_start == rsm->r_start) { 3953 /* 3954 * Undo what we ratched down and exit recovery if 3955 * possible 3956 */ 3957 EXIT_RECOVERY(tp->t_flags); 3958 tp->snd_recover = tp->snd_una; 3959 if (rack->r_ctl.rc_cwnd_at > tp->snd_cwnd) 3960 tp->snd_cwnd = rack->r_ctl.rc_cwnd_at; 3961 if (rack->r_ctl.rc_ssthresh_at > tp->snd_ssthresh) 3962 tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at; 3963 } 3964 } 3965 if (rsm->r_flags & RACK_WAS_SACKPASS) { 3966 /* 3967 * We retransmitted based on a sack and the earlier 3968 * retransmission ack'd it - re-ordering is occuring. 3969 */ 3970 counter_u64_add(rack_reorder_seen, 1); 3971 rack->r_ctl.rc_reorder_ts = cts; 3972 } 3973 counter_u64_add(rack_badfr, 1); 3974 counter_u64_add(rack_badfr_bytes, (rsm->r_end - rsm->r_start)); 3975 } 3976 3977 3978 static int 3979 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack, 3980 struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type) 3981 { 3982 int32_t i; 3983 uint32_t t; 3984 3985 if (rsm->r_flags & RACK_ACKED) 3986 /* Already done */ 3987 return (0); 3988 3989 3990 if ((rsm->r_rtr_cnt == 1) || 3991 ((ack_type == CUM_ACKED) && 3992 (to->to_flags & TOF_TS) && 3993 (to->to_tsecr) && 3994 (rsm->r_tim_lastsent[rsm->r_rtr_cnt - 1] == to->to_tsecr)) 3995 ) { 3996 /* 3997 * We will only find a matching timestamp if its cum-acked. 3998 * But if its only one retransmission its for-sure matching 3999 * :-) 4000 */ 4001 t = cts - rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]; 4002 if ((int)t <= 0) 4003 t = 1; 4004 if (!tp->t_rttlow || tp->t_rttlow > t) 4005 tp->t_rttlow = t; 4006 if (!rack->r_ctl.rc_rack_min_rtt || 4007 SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) { 4008 rack->r_ctl.rc_rack_min_rtt = t; 4009 if (rack->r_ctl.rc_rack_min_rtt == 0) { 4010 rack->r_ctl.rc_rack_min_rtt = 1; 4011 } 4012 } 4013 tcp_rack_xmit_timer(rack, t + 1); 4014 if ((rsm->r_flags & RACK_TLP) && 4015 (!IN_RECOVERY(tp->t_flags))) { 4016 /* Segment was a TLP and our retrans matched */ 4017 if (rack->r_ctl.rc_tlp_cwnd_reduce) { 4018 rack->r_ctl.rc_rsm_start = tp->snd_max; 4019 rack->r_ctl.rc_cwnd_at = tp->snd_cwnd; 4020 rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh; 4021 rack_cong_signal(tp, NULL, CC_NDUPACK); 4022 /* 4023 * When we enter recovery we need to assure 4024 * we send one packet. 4025 */ 4026 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 4027 rack_log_to_prr(rack, 7); 4028 } 4029 } 4030 if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) { 4031 /* New more recent rack_tmit_time */ 4032 rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]; 4033 rack->rc_rack_rtt = t; 4034 } 4035 return (1); 4036 } 4037 /* 4038 * We clear the soft/rxtshift since we got an ack. 4039 * There is no assurance we will call the commit() function 4040 * so we need to clear these to avoid incorrect handling. 4041 */ 4042 tp->t_rxtshift = 0; 4043 tp->t_softerror = 0; 4044 if ((to->to_flags & TOF_TS) && 4045 (ack_type == CUM_ACKED) && 4046 (to->to_tsecr) && 4047 ((rsm->r_flags & RACK_OVERMAX) == 0)) { 4048 /* 4049 * Now which timestamp does it match? In this block the ACK 4050 * must be coming from a previous transmission. 4051 */ 4052 for (i = 0; i < rsm->r_rtr_cnt; i++) { 4053 if (rsm->r_tim_lastsent[i] == to->to_tsecr) { 4054 t = cts - rsm->r_tim_lastsent[i]; 4055 if ((int)t <= 0) 4056 t = 1; 4057 if ((i + 1) < rsm->r_rtr_cnt) { 4058 /* Likely */ 4059 rack_earlier_retran(tp, rsm, t, cts); 4060 } 4061 if (!tp->t_rttlow || tp->t_rttlow > t) 4062 tp->t_rttlow = t; 4063 if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) { 4064 rack->r_ctl.rc_rack_min_rtt = t; 4065 if (rack->r_ctl.rc_rack_min_rtt == 0) { 4066 rack->r_ctl.rc_rack_min_rtt = 1; 4067 } 4068 } 4069 /* 4070 * Note the following calls to 4071 * tcp_rack_xmit_timer() are being commented 4072 * out for now. They give us no more accuracy 4073 * and often lead to a wrong choice. We have 4074 * enough samples that have not been 4075 * retransmitted. I leave the commented out 4076 * code in here in case in the future we 4077 * decide to add it back (though I can't forsee 4078 * doing that). That way we will easily see 4079 * where they need to be placed. 4080 */ 4081 if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, 4082 rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) { 4083 /* New more recent rack_tmit_time */ 4084 rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]; 4085 rack->rc_rack_rtt = t; 4086 } 4087 return (1); 4088 } 4089 } 4090 goto ts_not_found; 4091 } else { 4092 /* 4093 * Ok its a SACK block that we retransmitted. or a windows 4094 * machine without timestamps. We can tell nothing from the 4095 * time-stamp since its not there or the time the peer last 4096 * recieved a segment that moved forward its cum-ack point. 4097 */ 4098 ts_not_found: 4099 i = rsm->r_rtr_cnt - 1; 4100 t = cts - rsm->r_tim_lastsent[i]; 4101 if ((int)t <= 0) 4102 t = 1; 4103 if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) { 4104 /* 4105 * We retransmitted and the ack came back in less 4106 * than the smallest rtt we have observed. We most 4107 * likey did an improper retransmit as outlined in 4108 * 4.2 Step 3 point 2 in the rack-draft. 4109 */ 4110 i = rsm->r_rtr_cnt - 2; 4111 t = cts - rsm->r_tim_lastsent[i]; 4112 rack_earlier_retran(tp, rsm, t, cts); 4113 } else if (rack->r_ctl.rc_rack_min_rtt) { 4114 /* 4115 * We retransmitted it and the retransmit did the 4116 * job. 4117 */ 4118 if (!rack->r_ctl.rc_rack_min_rtt || 4119 SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) { 4120 rack->r_ctl.rc_rack_min_rtt = t; 4121 if (rack->r_ctl.rc_rack_min_rtt == 0) { 4122 rack->r_ctl.rc_rack_min_rtt = 1; 4123 } 4124 } 4125 if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, rsm->r_tim_lastsent[i])) { 4126 /* New more recent rack_tmit_time */ 4127 rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[i]; 4128 rack->rc_rack_rtt = t; 4129 } 4130 return (1); 4131 } 4132 } 4133 return (0); 4134 } 4135 4136 /* 4137 * Mark the SACK_PASSED flag on all entries prior to rsm send wise. 4138 */ 4139 static void 4140 rack_log_sack_passed(struct tcpcb *tp, 4141 struct tcp_rack *rack, struct rack_sendmap *rsm) 4142 { 4143 struct rack_sendmap *nrsm; 4144 4145 nrsm = rsm; 4146 TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap, 4147 rack_head, r_tnext) { 4148 if (nrsm == rsm) { 4149 /* Skip orginal segment he is acked */ 4150 continue; 4151 } 4152 if (nrsm->r_flags & RACK_ACKED) { 4153 /* 4154 * Skip ack'd segments, though we 4155 * should not see these, since tmap 4156 * should not have ack'd segments. 4157 */ 4158 continue; 4159 } 4160 if (nrsm->r_flags & RACK_SACK_PASSED) { 4161 /* 4162 * We found one that is already marked 4163 * passed, we have been here before and 4164 * so all others below this are marked. 4165 */ 4166 break; 4167 } 4168 nrsm->r_flags |= RACK_SACK_PASSED; 4169 nrsm->r_flags &= ~RACK_WAS_SACKPASS; 4170 } 4171 } 4172 4173 static uint32_t 4174 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack, 4175 struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two) 4176 { 4177 uint32_t start, end, changed = 0; 4178 struct rack_sendmap stack_map; 4179 struct rack_sendmap *rsm, *nrsm, fe, *insret, *prev, *next; 4180 int32_t used_ref = 1; 4181 int moved = 0; 4182 4183 start = sack->start; 4184 end = sack->end; 4185 rsm = *prsm; 4186 memset(&fe, 0, sizeof(fe)); 4187 do_rest_ofb: 4188 if ((rsm == NULL) || 4189 (SEQ_LT(end, rsm->r_start)) || 4190 (SEQ_GEQ(start, rsm->r_end)) || 4191 (SEQ_LT(start, rsm->r_start))) { 4192 /* 4193 * We are not in the right spot, 4194 * find the correct spot in the tree. 4195 */ 4196 used_ref = 0; 4197 fe.r_start = start; 4198 rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe); 4199 moved++; 4200 } 4201 if (rsm == NULL) { 4202 /* TSNH */ 4203 goto out; 4204 } 4205 /* Ok we have an ACK for some piece of this rsm */ 4206 if (rsm->r_start != start) { 4207 if ((rsm->r_flags & RACK_ACKED) == 0) { 4208 /** 4209 * Need to split this in two pieces the before and after, 4210 * the before remains in the map, the after must be 4211 * added. In other words we have: 4212 * rsm |--------------| 4213 * sackblk |-------> 4214 * rsm will become 4215 * rsm |---| 4216 * and nrsm will be the sacked piece 4217 * nrsm |----------| 4218 * 4219 * But before we start down that path lets 4220 * see if the sack spans over on top of 4221 * the next guy and it is already sacked. 4222 */ 4223 next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4224 if (next && (next->r_flags & RACK_ACKED) && 4225 SEQ_GEQ(end, next->r_start)) { 4226 /** 4227 * So the next one is already acked, and 4228 * we can thus by hookery use our stack_map 4229 * to reflect the piece being sacked and 4230 * then adjust the two tree entries moving 4231 * the start and ends around. So we start like: 4232 * rsm |------------| (not-acked) 4233 * next |-----------| (acked) 4234 * sackblk |--------> 4235 * We want to end like so: 4236 * rsm |------| (not-acked) 4237 * next |-----------------| (acked) 4238 * nrsm |-----| 4239 * Where nrsm is a temporary stack piece we 4240 * use to update all the gizmos. 4241 */ 4242 /* Copy up our fudge block */ 4243 nrsm = &stack_map; 4244 memcpy(nrsm, rsm, sizeof(struct rack_sendmap)); 4245 /* Now adjust our tree blocks */ 4246 rsm->r_end = start; 4247 next->r_start = start; 4248 /* Clear out the dup ack count of the remainder */ 4249 rsm->r_dupack = 0; 4250 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 4251 /* Now lets make sure our fudge block is right */ 4252 nrsm->r_start = start; 4253 /* Now lets update all the stats and such */ 4254 rack_update_rtt(tp, rack, nrsm, to, cts, SACKED); 4255 changed += (nrsm->r_end - nrsm->r_start); 4256 rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start); 4257 if (nrsm->r_flags & RACK_SACK_PASSED) { 4258 counter_u64_add(rack_reorder_seen, 1); 4259 rack->r_ctl.rc_reorder_ts = cts; 4260 } 4261 /* 4262 * Now we want to go up from rsm (the 4263 * one left un-acked) to the next one 4264 * in the tmap. We do this so when 4265 * we walk backwards we include marking 4266 * sack-passed on rsm (The one passed in 4267 * is skipped since it is generally called 4268 * on something sacked before removing it 4269 * from the tmap). 4270 */ 4271 if (rsm->r_in_tmap) { 4272 nrsm = TAILQ_NEXT(rsm, r_tnext); 4273 /* 4274 * Now that we have the next 4275 * one walk backwards from there. 4276 */ 4277 if (nrsm && nrsm->r_in_tmap) 4278 rack_log_sack_passed(tp, rack, nrsm); 4279 } 4280 /* Now are we done? */ 4281 if (SEQ_LT(end, next->r_end) || 4282 (end == next->r_end)) { 4283 /* Done with block */ 4284 goto out; 4285 } 4286 counter_u64_add(rack_sack_used_next_merge, 1); 4287 /* Postion for the next block */ 4288 start = next->r_end; 4289 rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next); 4290 if (rsm == NULL) 4291 goto out; 4292 } else { 4293 /** 4294 * We can't use any hookery here, so we 4295 * need to split the map. We enter like 4296 * so: 4297 * rsm |--------| 4298 * sackblk |-----> 4299 * We will add the new block nrsm and 4300 * that will be the new portion, and then 4301 * fall through after reseting rsm. So we 4302 * split and look like this: 4303 * rsm |----| 4304 * sackblk |-----> 4305 * nrsm |---| 4306 * We then fall through reseting 4307 * rsm to nrsm, so the next block 4308 * picks it up. 4309 */ 4310 nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT); 4311 if (nrsm == NULL) { 4312 /* 4313 * failed XXXrrs what can we do but loose the sack 4314 * info? 4315 */ 4316 goto out; 4317 } 4318 counter_u64_add(rack_sack_splits, 1); 4319 rack_clone_rsm(rack, nrsm, rsm, start); 4320 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 4321 #ifdef INVARIANTS 4322 if (insret != NULL) { 4323 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 4324 nrsm, insret, rack, rsm); 4325 } 4326 #endif 4327 if (rsm->r_in_tmap) { 4328 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 4329 nrsm->r_in_tmap = 1; 4330 } 4331 rsm->r_flags &= (~RACK_HAS_FIN); 4332 /* Position us to point to the new nrsm that starts the sack blk */ 4333 rsm = nrsm; 4334 } 4335 } else { 4336 /* Already sacked this piece */ 4337 counter_u64_add(rack_sack_skipped_acked, 1); 4338 moved++; 4339 if (end == rsm->r_end) { 4340 /* Done with block */ 4341 rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4342 goto out; 4343 } else if (SEQ_LT(end, rsm->r_end)) { 4344 /* A partial sack to a already sacked block */ 4345 moved++; 4346 rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4347 goto out; 4348 } else { 4349 /* 4350 * The end goes beyond this guy 4351 * repostion the start to the 4352 * next block. 4353 */ 4354 start = rsm->r_end; 4355 rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4356 if (rsm == NULL) 4357 goto out; 4358 } 4359 } 4360 } 4361 if (SEQ_GEQ(end, rsm->r_end)) { 4362 /** 4363 * The end of this block is either beyond this guy or right 4364 * at this guy. I.e.: 4365 * rsm --- |-----| 4366 * end |-----| 4367 * <or> 4368 * end |---------| 4369 */ 4370 if (rsm->r_flags & RACK_TLP) 4371 rack->r_ctl.rc_tlp_rtx_out = 0; 4372 if ((rsm->r_flags & RACK_ACKED) == 0) { 4373 rack_update_rtt(tp, rack, rsm, to, cts, SACKED); 4374 changed += (rsm->r_end - rsm->r_start); 4375 rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start); 4376 if (rsm->r_in_tmap) /* should be true */ 4377 rack_log_sack_passed(tp, rack, rsm); 4378 /* Is Reordering occuring? */ 4379 if (rsm->r_flags & RACK_SACK_PASSED) { 4380 rsm->r_flags &= ~RACK_SACK_PASSED; 4381 counter_u64_add(rack_reorder_seen, 1); 4382 rack->r_ctl.rc_reorder_ts = cts; 4383 } 4384 rsm->r_flags |= RACK_ACKED; 4385 rsm->r_flags &= ~RACK_TLP; 4386 if (rsm->r_in_tmap) { 4387 TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext); 4388 rsm->r_in_tmap = 0; 4389 } 4390 } else { 4391 counter_u64_add(rack_sack_skipped_acked, 1); 4392 moved++; 4393 } 4394 if (end == rsm->r_end) { 4395 /* This block only - done, setup for next */ 4396 goto out; 4397 } 4398 /* 4399 * There is more not coverend by this rsm move on 4400 * to the next block in the RB tree. 4401 */ 4402 nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4403 start = rsm->r_end; 4404 rsm = nrsm; 4405 if (rsm == NULL) 4406 goto out; 4407 goto do_rest_ofb; 4408 } 4409 /** 4410 * The end of this sack block is smaller than 4411 * our rsm i.e.: 4412 * rsm --- |-----| 4413 * end |--| 4414 */ 4415 if ((rsm->r_flags & RACK_ACKED) == 0) { 4416 prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4417 if (prev && (prev->r_flags & RACK_ACKED)) { 4418 /** 4419 * Goal, we want the right remainder of rsm to shrink 4420 * in place and span from (rsm->r_start = end) to rsm->r_end. 4421 * We want to expand prev to go all the way 4422 * to prev->r_end <- end. 4423 * so in the tree we have before: 4424 * prev |--------| (acked) 4425 * rsm |-------| (non-acked) 4426 * sackblk |-| 4427 * We churn it so we end up with 4428 * prev |----------| (acked) 4429 * rsm |-----| (non-acked) 4430 * nrsm |-| (temporary) 4431 */ 4432 nrsm = &stack_map; 4433 memcpy(nrsm, rsm, sizeof(struct rack_sendmap)); 4434 prev->r_end = end; 4435 rsm->r_start = end; 4436 /* Now adjust nrsm (stack copy) to be 4437 * the one that is the small 4438 * piece that was "sacked". 4439 */ 4440 nrsm->r_end = end; 4441 rsm->r_dupack = 0; 4442 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 4443 /* 4444 * Now nrsm is our new little piece 4445 * that is acked (which was merged 4446 * to prev). Update the rtt and changed 4447 * based on that. Also check for reordering. 4448 */ 4449 rack_update_rtt(tp, rack, nrsm, to, cts, SACKED); 4450 changed += (nrsm->r_end - nrsm->r_start); 4451 rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start); 4452 if (nrsm->r_flags & RACK_SACK_PASSED) { 4453 counter_u64_add(rack_reorder_seen, 1); 4454 rack->r_ctl.rc_reorder_ts = cts; 4455 } 4456 rsm = prev; 4457 counter_u64_add(rack_sack_used_prev_merge, 1); 4458 } else { 4459 /** 4460 * This is the case where our previous 4461 * block is not acked either, so we must 4462 * split the block in two. 4463 */ 4464 nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT); 4465 if (nrsm == NULL) { 4466 /* failed rrs what can we do but loose the sack info? */ 4467 goto out; 4468 } 4469 /** 4470 * In this case nrsm becomes 4471 * nrsm->r_start = end; 4472 * nrsm->r_end = rsm->r_end; 4473 * which is un-acked. 4474 * <and> 4475 * rsm->r_end = nrsm->r_start; 4476 * i.e. the remaining un-acked 4477 * piece is left on the left 4478 * hand side. 4479 * 4480 * So we start like this 4481 * rsm |----------| (not acked) 4482 * sackblk |---| 4483 * build it so we have 4484 * rsm |---| (acked) 4485 * nrsm |------| (not acked) 4486 */ 4487 counter_u64_add(rack_sack_splits, 1); 4488 rack_clone_rsm(rack, nrsm, rsm, end); 4489 rsm->r_flags &= (~RACK_HAS_FIN); 4490 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 4491 #ifdef INVARIANTS 4492 if (insret != NULL) { 4493 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 4494 nrsm, insret, rack, rsm); 4495 } 4496 #endif 4497 if (rsm->r_in_tmap) { 4498 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 4499 nrsm->r_in_tmap = 1; 4500 } 4501 nrsm->r_dupack = 0; 4502 rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2); 4503 if (rsm->r_flags & RACK_TLP) 4504 rack->r_ctl.rc_tlp_rtx_out = 0; 4505 rack_update_rtt(tp, rack, rsm, to, cts, SACKED); 4506 changed += (rsm->r_end - rsm->r_start); 4507 rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start); 4508 if (rsm->r_in_tmap) /* should be true */ 4509 rack_log_sack_passed(tp, rack, rsm); 4510 /* Is Reordering occuring? */ 4511 if (rsm->r_flags & RACK_SACK_PASSED) { 4512 rsm->r_flags &= ~RACK_SACK_PASSED; 4513 counter_u64_add(rack_reorder_seen, 1); 4514 rack->r_ctl.rc_reorder_ts = cts; 4515 } 4516 rsm->r_flags |= RACK_ACKED; 4517 rsm->r_flags &= ~RACK_TLP; 4518 if (rsm->r_in_tmap) { 4519 TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext); 4520 rsm->r_in_tmap = 0; 4521 } 4522 } 4523 } else if (start != end){ 4524 /* 4525 * The block was already acked. 4526 */ 4527 counter_u64_add(rack_sack_skipped_acked, 1); 4528 moved++; 4529 } 4530 out: 4531 if (rsm && (rsm->r_flags & RACK_ACKED)) { 4532 /* 4533 * Now can we merge where we worked 4534 * with either the previous or 4535 * next block? 4536 */ 4537 next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4538 while (next) { 4539 if (next->r_flags & RACK_ACKED) { 4540 /* yep this and next can be merged */ 4541 rsm = rack_merge_rsm(rack, rsm, next); 4542 next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4543 } else 4544 break; 4545 } 4546 /* Now what about the previous? */ 4547 prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4548 while (prev) { 4549 if (prev->r_flags & RACK_ACKED) { 4550 /* yep the previous and this can be merged */ 4551 rsm = rack_merge_rsm(rack, prev, rsm); 4552 prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4553 } else 4554 break; 4555 } 4556 } 4557 if (used_ref == 0) { 4558 counter_u64_add(rack_sack_proc_all, 1); 4559 } else { 4560 counter_u64_add(rack_sack_proc_short, 1); 4561 } 4562 /* Save off the next one for quick reference. */ 4563 if (rsm) 4564 nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4565 else 4566 nrsm = NULL; 4567 *prsm = rack->r_ctl.rc_sacklast = nrsm; 4568 /* Pass back the moved. */ 4569 *moved_two = moved; 4570 return (changed); 4571 } 4572 4573 static void inline 4574 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack) 4575 { 4576 struct rack_sendmap *tmap; 4577 4578 tmap = NULL; 4579 while (rsm && (rsm->r_flags & RACK_ACKED)) { 4580 /* Its no longer sacked, mark it so */ 4581 rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start); 4582 #ifdef INVARIANTS 4583 if (rsm->r_in_tmap) { 4584 panic("rack:%p rsm:%p flags:0x%x in tmap?", 4585 rack, rsm, rsm->r_flags); 4586 } 4587 #endif 4588 rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS); 4589 /* Rebuild it into our tmap */ 4590 if (tmap == NULL) { 4591 TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext); 4592 tmap = rsm; 4593 } else { 4594 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext); 4595 tmap = rsm; 4596 } 4597 tmap->r_in_tmap = 1; 4598 rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4599 } 4600 /* 4601 * Now lets possibly clear the sack filter so we start 4602 * recognizing sacks that cover this area. 4603 */ 4604 if (rack_use_sack_filter) 4605 sack_filter_clear(&rack->r_ctl.rack_sf, th_ack); 4606 4607 } 4608 4609 static void 4610 rack_do_decay(struct tcp_rack *rack) 4611 { 4612 #ifdef NETFLIX_EXP_DETECTION 4613 struct timeval res; 4614 4615 #define timersub(tvp, uvp, vvp) \ 4616 do { \ 4617 (vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec; \ 4618 (vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec; \ 4619 if ((vvp)->tv_usec < 0) { \ 4620 (vvp)->tv_sec--; \ 4621 (vvp)->tv_usec += 1000000; \ 4622 } \ 4623 } while (0) 4624 4625 timersub(&rack->r_ctl.rc_last_ack, &rack->r_ctl.rc_last_time_decay, &res); 4626 #undef timersub 4627 4628 rack->r_ctl.input_pkt++; 4629 if ((rack->rc_in_persist) || 4630 (res.tv_sec >= 1) || 4631 (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) { 4632 /* 4633 * Check for decay of non-SAD, 4634 * we want all SAD detection metrics to 4635 * decay 1/4 per second (or more) passed. 4636 */ 4637 uint32_t pkt_delta; 4638 4639 pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt; 4640 /* Update our saved tracking values */ 4641 rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt; 4642 rack->r_ctl.rc_last_time_decay = rack->r_ctl.rc_last_ack; 4643 /* Now do we escape without decay? */ 4644 if (rack->rc_in_persist || 4645 (rack->rc_tp->snd_max == rack->rc_tp->snd_una) || 4646 (pkt_delta < tcp_sad_low_pps)){ 4647 /* 4648 * We don't decay idle connections 4649 * or ones that have a low input pps. 4650 */ 4651 return; 4652 } 4653 /* Decay the counters */ 4654 rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count, 4655 tcp_sad_decay_val); 4656 rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count, 4657 tcp_sad_decay_val); 4658 rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra, 4659 tcp_sad_decay_val); 4660 rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move, 4661 tcp_sad_decay_val); 4662 } 4663 #endif 4664 } 4665 4666 static void 4667 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th) 4668 { 4669 uint32_t changed, entered_recovery = 0; 4670 struct tcp_rack *rack; 4671 struct rack_sendmap *rsm, *rm; 4672 struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1]; 4673 register uint32_t th_ack; 4674 int32_t i, j, k, num_sack_blks = 0; 4675 uint32_t cts, acked, ack_point, sack_changed = 0; 4676 int loop_start = 0, moved_two = 0; 4677 4678 INP_WLOCK_ASSERT(tp->t_inpcb); 4679 if (th->th_flags & TH_RST) { 4680 /* We don't log resets */ 4681 return; 4682 } 4683 rack = (struct tcp_rack *)tp->t_fb_ptr; 4684 cts = tcp_ts_getticks(); 4685 rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 4686 changed = 0; 4687 th_ack = th->th_ack; 4688 if (rack->sack_attack_disable == 0) 4689 rack_do_decay(rack); 4690 if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) { 4691 /* 4692 * You only get credit for 4693 * MSS and greater (and you get extra 4694 * credit for larger cum-ack moves). 4695 */ 4696 int ac; 4697 4698 ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp); 4699 rack->r_ctl.ack_count += ac; 4700 counter_u64_add(rack_ack_total, ac); 4701 } 4702 if (rack->r_ctl.ack_count > 0xfff00000) { 4703 /* 4704 * reduce the number to keep us under 4705 * a uint32_t. 4706 */ 4707 rack->r_ctl.ack_count /= 2; 4708 rack->r_ctl.sack_count /= 2; 4709 } 4710 if (SEQ_GT(th_ack, tp->snd_una)) { 4711 rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__); 4712 tp->t_acktime = ticks; 4713 } 4714 if (rsm && SEQ_GT(th_ack, rsm->r_start)) 4715 changed = th_ack - rsm->r_start; 4716 if (changed) { 4717 /* 4718 * The ACK point is advancing to th_ack, we must drop off 4719 * the packets in the rack log and calculate any eligble 4720 * RTT's. 4721 */ 4722 rack->r_wanted_output++; 4723 more: 4724 rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 4725 if (rsm == NULL) { 4726 if ((th_ack - 1) == tp->iss) { 4727 /* 4728 * For the SYN incoming case we will not 4729 * have called tcp_output for the sending of 4730 * the SYN, so there will be no map. All 4731 * other cases should probably be a panic. 4732 */ 4733 goto proc_sack; 4734 } 4735 if (tp->t_flags & TF_SENTFIN) { 4736 /* if we send a FIN we will not hav a map */ 4737 goto proc_sack; 4738 } 4739 #ifdef INVARIANTS 4740 panic("No rack map tp:%p for th:%p state:%d rack:%p snd_una:%u snd_max:%u snd_nxt:%u chg:%d\n", 4741 tp, 4742 th, tp->t_state, rack, 4743 tp->snd_una, tp->snd_max, tp->snd_nxt, changed); 4744 #endif 4745 goto proc_sack; 4746 } 4747 if (SEQ_LT(th_ack, rsm->r_start)) { 4748 /* Huh map is missing this */ 4749 #ifdef INVARIANTS 4750 printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n", 4751 rsm->r_start, 4752 th_ack, tp->t_state, rack->r_state); 4753 #endif 4754 goto proc_sack; 4755 } 4756 rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED); 4757 /* Now do we consume the whole thing? */ 4758 if (SEQ_GEQ(th_ack, rsm->r_end)) { 4759 /* Its all consumed. */ 4760 uint32_t left; 4761 4762 rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes; 4763 rsm->r_rtr_bytes = 0; 4764 if (rsm->r_flags & RACK_TLP) 4765 rack->r_ctl.rc_tlp_rtx_out = 0; 4766 rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4767 #ifdef INVARIANTS 4768 if (rm != rsm) { 4769 panic("removing head in rack:%p rsm:%p rm:%p", 4770 rack, rsm, rm); 4771 } 4772 #endif 4773 if (rsm->r_in_tmap) { 4774 TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext); 4775 rsm->r_in_tmap = 0; 4776 } 4777 if (rsm->r_flags & RACK_ACKED) { 4778 /* 4779 * It was acked on the scoreboard -- remove 4780 * it from total 4781 */ 4782 rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start); 4783 } else if (rsm->r_flags & RACK_SACK_PASSED) { 4784 /* 4785 * There are segments ACKED on the 4786 * scoreboard further up. We are seeing 4787 * reordering. 4788 */ 4789 rsm->r_flags &= ~RACK_SACK_PASSED; 4790 counter_u64_add(rack_reorder_seen, 1); 4791 rsm->r_flags |= RACK_ACKED; 4792 rack->r_ctl.rc_reorder_ts = cts; 4793 } 4794 left = th_ack - rsm->r_end; 4795 if (rsm->r_rtr_cnt > 1) { 4796 /* 4797 * Technically we should make r_rtr_cnt be 4798 * monotonicly increasing and just mod it to 4799 * the timestamp it is replacing.. that way 4800 * we would have the last 3 retransmits. Now 4801 * rc_loss_count will be wrong if we 4802 * retransmit something more than 2 times in 4803 * recovery :( 4804 */ 4805 rack->r_ctl.rc_loss_count += (rsm->r_rtr_cnt - 1); 4806 } 4807 /* Free back to zone */ 4808 rack_free(rack, rsm); 4809 if (left) { 4810 goto more; 4811 } 4812 goto proc_sack; 4813 } 4814 if (rsm->r_flags & RACK_ACKED) { 4815 /* 4816 * It was acked on the scoreboard -- remove it from 4817 * total for the part being cum-acked. 4818 */ 4819 rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start); 4820 } 4821 /* 4822 * Clear the dup ack count for 4823 * the piece that remains. 4824 */ 4825 rsm->r_dupack = 0; 4826 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 4827 if (rsm->r_rtr_bytes) { 4828 /* 4829 * It was retransmitted adjust the 4830 * sack holes for what was acked. 4831 */ 4832 int ack_am; 4833 4834 ack_am = (th_ack - rsm->r_start); 4835 if (ack_am >= rsm->r_rtr_bytes) { 4836 rack->r_ctl.rc_holes_rxt -= ack_am; 4837 rsm->r_rtr_bytes -= ack_am; 4838 } 4839 } 4840 /* Update where the piece starts */ 4841 rsm->r_start = th_ack; 4842 } 4843 proc_sack: 4844 /* Check for reneging */ 4845 rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 4846 if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) { 4847 /* 4848 * The peer has moved snd_una up to 4849 * the edge of this send, i.e. one 4850 * that it had previously acked. The only 4851 * way that can be true if the peer threw 4852 * away data (space issues) that it had 4853 * previously sacked (else it would have 4854 * given us snd_una up to (rsm->r_end). 4855 * We need to undo the acked markings here. 4856 * 4857 * Note we have to look to make sure th_ack is 4858 * our rsm->r_start in case we get an old ack 4859 * where th_ack is behind snd_una. 4860 */ 4861 rack_peer_reneges(rack, rsm, th->th_ack); 4862 } 4863 if ((to->to_flags & TOF_SACK) == 0) { 4864 /* We are done nothing left */ 4865 goto out; 4866 } 4867 /* Sack block processing */ 4868 if (SEQ_GT(th_ack, tp->snd_una)) 4869 ack_point = th_ack; 4870 else 4871 ack_point = tp->snd_una; 4872 for (i = 0; i < to->to_nsacks; i++) { 4873 bcopy((to->to_sacks + i * TCPOLEN_SACK), 4874 &sack, sizeof(sack)); 4875 sack.start = ntohl(sack.start); 4876 sack.end = ntohl(sack.end); 4877 if (SEQ_GT(sack.end, sack.start) && 4878 SEQ_GT(sack.start, ack_point) && 4879 SEQ_LT(sack.start, tp->snd_max) && 4880 SEQ_GT(sack.end, ack_point) && 4881 SEQ_LEQ(sack.end, tp->snd_max)) { 4882 sack_blocks[num_sack_blks] = sack; 4883 num_sack_blks++; 4884 #ifdef NETFLIX_STATS 4885 } else if (SEQ_LEQ(sack.start, th_ack) && 4886 SEQ_LEQ(sack.end, th_ack)) { 4887 /* 4888 * Its a D-SACK block. 4889 */ 4890 tcp_record_dsack(sack.start, sack.end); 4891 #endif 4892 } 4893 4894 } 4895 /* 4896 * Sort the SACK blocks so we can update the rack scoreboard with 4897 * just one pass. 4898 */ 4899 if (rack_use_sack_filter) { 4900 num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks, 4901 num_sack_blks, th->th_ack); 4902 ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks); 4903 } 4904 if (num_sack_blks == 0) { 4905 /* Nothing to sack (DSACKs?) */ 4906 goto out_with_totals; 4907 } 4908 if (num_sack_blks < 2) { 4909 /* Only one, we don't need to sort */ 4910 goto do_sack_work; 4911 } 4912 /* Sort the sacks */ 4913 for (i = 0; i < num_sack_blks; i++) { 4914 for (j = i + 1; j < num_sack_blks; j++) { 4915 if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) { 4916 sack = sack_blocks[i]; 4917 sack_blocks[i] = sack_blocks[j]; 4918 sack_blocks[j] = sack; 4919 } 4920 } 4921 } 4922 /* 4923 * Now are any of the sack block ends the same (yes some 4924 * implementations send these)? 4925 */ 4926 again: 4927 if (num_sack_blks == 0) 4928 goto out_with_totals; 4929 if (num_sack_blks > 1) { 4930 for (i = 0; i < num_sack_blks; i++) { 4931 for (j = i + 1; j < num_sack_blks; j++) { 4932 if (sack_blocks[i].end == sack_blocks[j].end) { 4933 /* 4934 * Ok these two have the same end we 4935 * want the smallest end and then 4936 * throw away the larger and start 4937 * again. 4938 */ 4939 if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) { 4940 /* 4941 * The second block covers 4942 * more area use that 4943 */ 4944 sack_blocks[i].start = sack_blocks[j].start; 4945 } 4946 /* 4947 * Now collapse out the dup-sack and 4948 * lower the count 4949 */ 4950 for (k = (j + 1); k < num_sack_blks; k++) { 4951 sack_blocks[j].start = sack_blocks[k].start; 4952 sack_blocks[j].end = sack_blocks[k].end; 4953 j++; 4954 } 4955 num_sack_blks--; 4956 goto again; 4957 } 4958 } 4959 } 4960 } 4961 do_sack_work: 4962 /* 4963 * First lets look to see if 4964 * we have retransmitted and 4965 * can use the transmit next? 4966 */ 4967 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 4968 if (rsm && 4969 SEQ_GT(sack_blocks[0].end, rsm->r_start) && 4970 SEQ_LT(sack_blocks[0].start, rsm->r_end)) { 4971 /* 4972 * We probably did the FR and the next 4973 * SACK in continues as we would expect. 4974 */ 4975 acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two); 4976 if (acked) { 4977 rack->r_wanted_output++; 4978 changed += acked; 4979 sack_changed += acked; 4980 } 4981 if (num_sack_blks == 1) { 4982 /* 4983 * This is what we would expect from 4984 * a normal implementation to happen 4985 * after we have retransmitted the FR, 4986 * i.e the sack-filter pushes down 4987 * to 1 block and the next to be retransmitted 4988 * is the sequence in the sack block (has more 4989 * are acked). Count this as ACK'd data to boost 4990 * up the chances of recovering any false positives. 4991 */ 4992 rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp)); 4993 counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp))); 4994 counter_u64_add(rack_express_sack, 1); 4995 if (rack->r_ctl.ack_count > 0xfff00000) { 4996 /* 4997 * reduce the number to keep us under 4998 * a uint32_t. 4999 */ 5000 rack->r_ctl.ack_count /= 2; 5001 rack->r_ctl.sack_count /= 2; 5002 } 5003 goto out_with_totals; 5004 } else { 5005 /* 5006 * Start the loop through the 5007 * rest of blocks, past the first block. 5008 */ 5009 moved_two = 0; 5010 loop_start = 1; 5011 } 5012 } 5013 /* Its a sack of some sort */ 5014 rack->r_ctl.sack_count++; 5015 if (rack->r_ctl.sack_count > 0xfff00000) { 5016 /* 5017 * reduce the number to keep us under 5018 * a uint32_t. 5019 */ 5020 rack->r_ctl.ack_count /= 2; 5021 rack->r_ctl.sack_count /= 2; 5022 } 5023 counter_u64_add(rack_sack_total, 1); 5024 if (rack->sack_attack_disable) { 5025 /* An attacker disablement is in place */ 5026 if (num_sack_blks > 1) { 5027 rack->r_ctl.sack_count += (num_sack_blks - 1); 5028 rack->r_ctl.sack_moved_extra++; 5029 counter_u64_add(rack_move_some, 1); 5030 if (rack->r_ctl.sack_moved_extra > 0xfff00000) { 5031 rack->r_ctl.sack_moved_extra /= 2; 5032 rack->r_ctl.sack_noextra_move /= 2; 5033 } 5034 } 5035 goto out; 5036 } 5037 rsm = rack->r_ctl.rc_sacklast; 5038 for (i = loop_start; i < num_sack_blks; i++) { 5039 acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two); 5040 if (acked) { 5041 rack->r_wanted_output++; 5042 changed += acked; 5043 sack_changed += acked; 5044 } 5045 if (moved_two) { 5046 /* 5047 * If we did not get a SACK for at least a MSS and 5048 * had to move at all, or if we moved more than our 5049 * threshold, it counts against the "extra" move. 5050 */ 5051 rack->r_ctl.sack_moved_extra += moved_two; 5052 counter_u64_add(rack_move_some, 1); 5053 } else { 5054 /* 5055 * else we did not have to move 5056 * any more than we would expect. 5057 */ 5058 rack->r_ctl.sack_noextra_move++; 5059 counter_u64_add(rack_move_none, 1); 5060 } 5061 if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) { 5062 /* 5063 * If the SACK was not a full MSS then 5064 * we add to sack_count the number of 5065 * MSS's (or possibly more than 5066 * a MSS if its a TSO send) we had to skip by. 5067 */ 5068 rack->r_ctl.sack_count += moved_two; 5069 counter_u64_add(rack_sack_total, moved_two); 5070 } 5071 /* 5072 * Now we need to setup for the next 5073 * round. First we make sure we won't 5074 * exceed the size of our uint32_t on 5075 * the various counts, and then clear out 5076 * moved_two. 5077 */ 5078 if ((rack->r_ctl.sack_moved_extra > 0xfff00000) || 5079 (rack->r_ctl.sack_noextra_move > 0xfff00000)) { 5080 rack->r_ctl.sack_moved_extra /= 2; 5081 rack->r_ctl.sack_noextra_move /= 2; 5082 } 5083 if (rack->r_ctl.sack_count > 0xfff00000) { 5084 rack->r_ctl.ack_count /= 2; 5085 rack->r_ctl.sack_count /= 2; 5086 } 5087 moved_two = 0; 5088 } 5089 out_with_totals: 5090 if (num_sack_blks > 1) { 5091 /* 5092 * You get an extra stroke if 5093 * you have more than one sack-blk, this 5094 * could be where we are skipping forward 5095 * and the sack-filter is still working, or 5096 * it could be an attacker constantly 5097 * moving us. 5098 */ 5099 rack->r_ctl.sack_moved_extra++; 5100 counter_u64_add(rack_move_some, 1); 5101 } 5102 out: 5103 #ifdef NETFLIX_EXP_DETECTION 5104 if ((rack->do_detection || tcp_force_detection) && 5105 tcp_sack_to_ack_thresh && 5106 tcp_sack_to_move_thresh && 5107 ((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) { 5108 /* 5109 * We have thresholds set to find 5110 * possible attackers and disable sack. 5111 * Check them. 5112 */ 5113 uint64_t ackratio, moveratio, movetotal; 5114 5115 /* Log detecting */ 5116 rack_log_sad(rack, 1); 5117 ackratio = (uint64_t)(rack->r_ctl.sack_count); 5118 ackratio *= (uint64_t)(1000); 5119 if (rack->r_ctl.ack_count) 5120 ackratio /= (uint64_t)(rack->r_ctl.ack_count); 5121 else { 5122 /* We really should not hit here */ 5123 ackratio = 1000; 5124 } 5125 if ((rack->sack_attack_disable == 0) && 5126 (ackratio > rack_highest_sack_thresh_seen)) 5127 rack_highest_sack_thresh_seen = (uint32_t)ackratio; 5128 movetotal = rack->r_ctl.sack_moved_extra; 5129 movetotal += rack->r_ctl.sack_noextra_move; 5130 moveratio = rack->r_ctl.sack_moved_extra; 5131 moveratio *= (uint64_t)1000; 5132 if (movetotal) 5133 moveratio /= movetotal; 5134 else { 5135 /* No moves, thats pretty good */ 5136 moveratio = 0; 5137 } 5138 if ((rack->sack_attack_disable == 0) && 5139 (moveratio > rack_highest_move_thresh_seen)) 5140 rack_highest_move_thresh_seen = (uint32_t)moveratio; 5141 if (rack->sack_attack_disable == 0) { 5142 if ((ackratio > tcp_sack_to_ack_thresh) && 5143 (moveratio > tcp_sack_to_move_thresh)) { 5144 /* Disable sack processing */ 5145 rack->sack_attack_disable = 1; 5146 if (rack->r_rep_attack == 0) { 5147 rack->r_rep_attack = 1; 5148 counter_u64_add(rack_sack_attacks_detected, 1); 5149 } 5150 if (tcp_attack_on_turns_on_logging) { 5151 /* 5152 * Turn on logging, used for debugging 5153 * false positives. 5154 */ 5155 rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging; 5156 } 5157 /* Clamp the cwnd at flight size */ 5158 rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd; 5159 rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 5160 rack_log_sad(rack, 2); 5161 } 5162 } else { 5163 /* We are sack-disabled check for false positives */ 5164 if ((ackratio <= tcp_restoral_thresh) || 5165 (rack->r_ctl.rc_num_maps_alloced < tcp_map_minimum)) { 5166 rack->sack_attack_disable = 0; 5167 rack_log_sad(rack, 3); 5168 /* Restart counting */ 5169 rack->r_ctl.sack_count = 0; 5170 rack->r_ctl.sack_moved_extra = 0; 5171 rack->r_ctl.sack_noextra_move = 1; 5172 rack->r_ctl.ack_count = max(1, 5173 (BYTES_THIS_ACK(tp, th)/ctf_fixed_maxseg(rack->rc_tp))); 5174 5175 if (rack->r_rep_reverse == 0) { 5176 rack->r_rep_reverse = 1; 5177 counter_u64_add(rack_sack_attacks_reversed, 1); 5178 } 5179 /* Restore the cwnd */ 5180 if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd) 5181 rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd; 5182 } 5183 } 5184 } 5185 #endif 5186 if (changed) { 5187 /* Something changed cancel the rack timer */ 5188 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 5189 } 5190 if ((sack_changed) && (!IN_RECOVERY(tp->t_flags))) { 5191 /* 5192 * Ok we have a high probability that we need to go in to 5193 * recovery since we have data sack'd 5194 */ 5195 struct rack_sendmap *rsm; 5196 uint32_t tsused; 5197 5198 tsused = tcp_ts_getticks(); 5199 rsm = tcp_rack_output(tp, rack, tsused); 5200 if (rsm) { 5201 /* Enter recovery */ 5202 rack->r_ctl.rc_rsm_start = rsm->r_start; 5203 rack->r_ctl.rc_cwnd_at = tp->snd_cwnd; 5204 rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh; 5205 entered_recovery = 1; 5206 rack_cong_signal(tp, NULL, CC_NDUPACK); 5207 /* 5208 * When we enter recovery we need to assure we send 5209 * one packet. 5210 */ 5211 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 5212 rack_log_to_prr(rack, 8); 5213 rack->r_timer_override = 1; 5214 } 5215 } 5216 if (IN_RECOVERY(tp->t_flags) && (entered_recovery == 0)) { 5217 /* Deal with changed and PRR here (in recovery only) */ 5218 uint32_t pipe, snd_una; 5219 5220 rack->r_ctl.rc_prr_delivered += changed; 5221 /* Compute prr_sndcnt */ 5222 if (SEQ_GT(tp->snd_una, th_ack)) { 5223 snd_una = tp->snd_una; 5224 } else { 5225 snd_una = th_ack; 5226 } 5227 pipe = ((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt; 5228 if (pipe > tp->snd_ssthresh) { 5229 long sndcnt; 5230 5231 sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh; 5232 if (rack->r_ctl.rc_prr_recovery_fs > 0) 5233 sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs; 5234 else { 5235 rack->r_ctl.rc_prr_sndcnt = 0; 5236 rack_log_to_prr(rack, 9); 5237 sndcnt = 0; 5238 } 5239 sndcnt++; 5240 if (sndcnt > (long)rack->r_ctl.rc_prr_out) 5241 sndcnt -= rack->r_ctl.rc_prr_out; 5242 else 5243 sndcnt = 0; 5244 rack->r_ctl.rc_prr_sndcnt = sndcnt; 5245 rack_log_to_prr(rack, 10); 5246 } else { 5247 uint32_t limit; 5248 5249 if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out) 5250 limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out); 5251 else 5252 limit = 0; 5253 if (changed > limit) 5254 limit = changed; 5255 limit += ctf_fixed_maxseg(tp); 5256 if (tp->snd_ssthresh > pipe) { 5257 rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit); 5258 rack_log_to_prr(rack, 11); 5259 } else { 5260 rack->r_ctl.rc_prr_sndcnt = min(0, limit); 5261 rack_log_to_prr(rack, 12); 5262 } 5263 } 5264 if (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) { 5265 rack->r_timer_override = 1; 5266 } 5267 } 5268 } 5269 5270 static void 5271 rack_strike_dupack(struct tcp_rack *rack) 5272 { 5273 struct rack_sendmap *rsm; 5274 5275 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 5276 if (rsm && (rsm->r_dupack < 0xff)) { 5277 rsm->r_dupack++; 5278 if (rsm->r_dupack >= DUP_ACK_THRESHOLD) { 5279 rack->r_wanted_output = 1; 5280 rack_log_retran_reason(rack, rsm, __LINE__, 1, 3); 5281 } else { 5282 rack_log_retran_reason(rack, rsm, __LINE__, 0, 3); 5283 } 5284 } 5285 } 5286 5287 /* 5288 * Return value of 1, we do not need to call rack_process_data(). 5289 * return value of 0, rack_process_data can be called. 5290 * For ret_val if its 0 the TCP is locked, if its non-zero 5291 * its unlocked and probably unsafe to touch the TCB. 5292 */ 5293 static int 5294 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so, 5295 struct tcpcb *tp, struct tcpopt *to, 5296 uint32_t tiwin, int32_t tlen, 5297 int32_t * ofia, int32_t thflags, int32_t * ret_val) 5298 { 5299 int32_t ourfinisacked = 0; 5300 int32_t nsegs, acked_amount; 5301 int32_t acked; 5302 struct mbuf *mfree; 5303 struct tcp_rack *rack; 5304 int32_t recovery = 0; 5305 5306 rack = (struct tcp_rack *)tp->t_fb_ptr; 5307 if (SEQ_GT(th->th_ack, tp->snd_max)) { 5308 ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val); 5309 rack->r_wanted_output++; 5310 return (1); 5311 } 5312 if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) { 5313 if (rack->rc_in_persist) 5314 tp->t_rxtshift = 0; 5315 if ((th->th_ack == tp->snd_una) && (tiwin == tp->snd_wnd)) 5316 rack_strike_dupack(rack); 5317 rack_log_ack(tp, to, th); 5318 } 5319 if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) { 5320 /* 5321 * Old ack, behind (or duplicate to) the last one rcv'd 5322 * Note: Should mark reordering is occuring! We should also 5323 * look for sack blocks arriving e.g. ack 1, 4-4 then ack 1, 5324 * 3-3, 4-4 would be reording. As well as ack 1, 3-3 <no 5325 * retran and> ack 3 5326 */ 5327 return (0); 5328 } 5329 /* 5330 * If we reach this point, ACK is not a duplicate, i.e., it ACKs 5331 * something we sent. 5332 */ 5333 if (tp->t_flags & TF_NEEDSYN) { 5334 /* 5335 * T/TCP: Connection was half-synchronized, and our SYN has 5336 * been ACK'd (so connection is now fully synchronized). Go 5337 * to non-starred state, increment snd_una for ACK of SYN, 5338 * and check if we can do window scaling. 5339 */ 5340 tp->t_flags &= ~TF_NEEDSYN; 5341 tp->snd_una++; 5342 /* Do window scaling? */ 5343 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) == 5344 (TF_RCVD_SCALE | TF_REQ_SCALE)) { 5345 tp->rcv_scale = tp->request_r_scale; 5346 /* Send window already scaled. */ 5347 } 5348 } 5349 nsegs = max(1, m->m_pkthdr.lro_nsegs); 5350 INP_WLOCK_ASSERT(tp->t_inpcb); 5351 5352 acked = BYTES_THIS_ACK(tp, th); 5353 TCPSTAT_ADD(tcps_rcvackpack, nsegs); 5354 TCPSTAT_ADD(tcps_rcvackbyte, acked); 5355 5356 /* 5357 * If we just performed our first retransmit, and the ACK arrives 5358 * within our recovery window, then it was a mistake to do the 5359 * retransmit in the first place. Recover our original cwnd and 5360 * ssthresh, and proceed to transmit where we left off. 5361 */ 5362 if (tp->t_flags & TF_PREVVALID) { 5363 tp->t_flags &= ~TF_PREVVALID; 5364 if (tp->t_rxtshift == 1 && 5365 (int)(ticks - tp->t_badrxtwin) < 0) 5366 rack_cong_signal(tp, th, CC_RTO_ERR); 5367 } 5368 /* 5369 * If we have a timestamp reply, update smoothed round trip time. If 5370 * no timestamp is present but transmit timer is running and timed 5371 * sequence number was acked, update smoothed round trip time. Since 5372 * we now have an rtt measurement, cancel the timer backoff (cf., 5373 * Phil Karn's retransmit alg.). Recompute the initial retransmit 5374 * timer. 5375 * 5376 * Some boxes send broken timestamp replies during the SYN+ACK 5377 * phase, ignore timestamps of 0 or we could calculate a huge RTT 5378 * and blow up the retransmit timer. 5379 */ 5380 /* 5381 * If all outstanding data is acked, stop retransmit timer and 5382 * remember to restart (more output or persist). If there is more 5383 * data to be acked, restart retransmit timer, using current 5384 * (possibly backed-off) value. 5385 */ 5386 if (th->th_ack == tp->snd_max) { 5387 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 5388 rack->r_wanted_output++; 5389 } 5390 if (acked == 0) { 5391 if (ofia) 5392 *ofia = ourfinisacked; 5393 return (0); 5394 } 5395 if (rack->r_ctl.rc_early_recovery) { 5396 if (IN_RECOVERY(tp->t_flags)) { 5397 if (SEQ_LT(th->th_ack, tp->snd_recover) && 5398 (SEQ_LT(th->th_ack, tp->snd_max))) { 5399 tcp_rack_partialack(tp, th); 5400 } else { 5401 rack_post_recovery(tp, th); 5402 recovery = 1; 5403 } 5404 } 5405 } 5406 /* 5407 * Let the congestion control algorithm update congestion control 5408 * related information. This typically means increasing the 5409 * congestion window. 5410 */ 5411 rack_ack_received(tp, rack, th, nsegs, CC_ACK, recovery); 5412 SOCKBUF_LOCK(&so->so_snd); 5413 acked_amount = min(acked, (int)sbavail(&so->so_snd)); 5414 tp->snd_wnd -= acked_amount; 5415 mfree = sbcut_locked(&so->so_snd, acked_amount); 5416 if ((sbused(&so->so_snd) == 0) && 5417 (acked > acked_amount) && 5418 (tp->t_state >= TCPS_FIN_WAIT_1)) { 5419 ourfinisacked = 1; 5420 } 5421 /* NB: sowwakeup_locked() does an implicit unlock. */ 5422 sowwakeup_locked(so); 5423 m_freem(mfree); 5424 if (rack->r_ctl.rc_early_recovery == 0) { 5425 if (IN_RECOVERY(tp->t_flags)) { 5426 if (SEQ_LT(th->th_ack, tp->snd_recover) && 5427 (SEQ_LT(th->th_ack, tp->snd_max))) { 5428 tcp_rack_partialack(tp, th); 5429 } else { 5430 rack_post_recovery(tp, th); 5431 } 5432 } 5433 } 5434 tp->snd_una = th->th_ack; 5435 if (SEQ_GT(tp->snd_una, tp->snd_recover)) 5436 tp->snd_recover = tp->snd_una; 5437 5438 if (SEQ_LT(tp->snd_nxt, tp->snd_una)) { 5439 tp->snd_nxt = tp->snd_una; 5440 } 5441 if (tp->snd_una == tp->snd_max) { 5442 /* Nothing left outstanding */ 5443 rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__); 5444 if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0) 5445 tp->t_acktime = 0; 5446 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 5447 /* Set need output so persist might get set */ 5448 rack->r_wanted_output++; 5449 if (rack_use_sack_filter) 5450 sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una); 5451 if ((tp->t_state >= TCPS_FIN_WAIT_1) && 5452 (sbavail(&so->so_snd) == 0) && 5453 (tp->t_flags2 & TF2_DROP_AF_DATA)) { 5454 /* 5455 * The socket was gone and the 5456 * peer sent data, time to 5457 * reset him. 5458 */ 5459 *ret_val = 1; 5460 tp = tcp_close(tp); 5461 ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen); 5462 return (1); 5463 } 5464 } 5465 if (ofia) 5466 *ofia = ourfinisacked; 5467 return (0); 5468 } 5469 5470 static void 5471 rack_collapsed_window(struct tcp_rack *rack) 5472 { 5473 /* 5474 * Now we must walk the 5475 * send map and divide the 5476 * ones left stranded. These 5477 * guys can't cause us to abort 5478 * the connection and are really 5479 * "unsent". However if a buggy 5480 * client actually did keep some 5481 * of the data i.e. collapsed the win 5482 * and refused to ack and then opened 5483 * the win and acked that data. We would 5484 * get into an ack war, the simplier 5485 * method then of just pretending we 5486 * did not send those segments something 5487 * won't work. 5488 */ 5489 struct rack_sendmap *rsm, *nrsm, fe, *insret; 5490 tcp_seq max_seq; 5491 uint32_t maxseg; 5492 5493 max_seq = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd; 5494 maxseg = ctf_fixed_maxseg(rack->rc_tp); 5495 memset(&fe, 0, sizeof(fe)); 5496 fe.r_start = max_seq; 5497 /* Find the first seq past or at maxseq */ 5498 rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe); 5499 if (rsm == NULL) { 5500 /* Nothing to do strange */ 5501 rack->rc_has_collapsed = 0; 5502 return; 5503 } 5504 /* 5505 * Now do we need to split at 5506 * the collapse point? 5507 */ 5508 if (SEQ_GT(max_seq, rsm->r_start)) { 5509 nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT); 5510 if (nrsm == NULL) { 5511 /* We can't get a rsm, mark all? */ 5512 nrsm = rsm; 5513 goto no_split; 5514 } 5515 /* Clone it */ 5516 rack_clone_rsm(rack, nrsm, rsm, max_seq); 5517 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 5518 #ifdef INVARIANTS 5519 if (insret != NULL) { 5520 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 5521 nrsm, insret, rack, rsm); 5522 } 5523 #endif 5524 if (rsm->r_in_tmap) { 5525 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 5526 nrsm->r_in_tmap = 1; 5527 } 5528 /* 5529 * Set in the new RSM as the 5530 * collapsed starting point 5531 */ 5532 rsm = nrsm; 5533 } 5534 no_split: 5535 counter_u64_add(rack_collapsed_win, 1); 5536 RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) { 5537 nrsm->r_flags |= RACK_RWND_COLLAPSED; 5538 rack->rc_has_collapsed = 1; 5539 } 5540 } 5541 5542 static void 5543 rack_un_collapse_window(struct tcp_rack *rack) 5544 { 5545 struct rack_sendmap *rsm; 5546 5547 RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) { 5548 if (rsm->r_flags & RACK_RWND_COLLAPSED) 5549 rsm->r_flags &= ~RACK_RWND_COLLAPSED; 5550 else 5551 break; 5552 } 5553 rack->rc_has_collapsed = 0; 5554 } 5555 5556 /* 5557 * Return value of 1, the TCB is unlocked and most 5558 * likely gone, return value of 0, the TCP is still 5559 * locked. 5560 */ 5561 static int 5562 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so, 5563 struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, 5564 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt) 5565 { 5566 /* 5567 * Update window information. Don't look at window if no ACK: TAC's 5568 * send garbage on first SYN. 5569 */ 5570 int32_t nsegs; 5571 int32_t tfo_syn; 5572 struct tcp_rack *rack; 5573 5574 rack = (struct tcp_rack *)tp->t_fb_ptr; 5575 INP_WLOCK_ASSERT(tp->t_inpcb); 5576 nsegs = max(1, m->m_pkthdr.lro_nsegs); 5577 if ((thflags & TH_ACK) && 5578 (SEQ_LT(tp->snd_wl1, th->th_seq) || 5579 (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) || 5580 (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) { 5581 /* keep track of pure window updates */ 5582 if (tlen == 0 && 5583 tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd) 5584 TCPSTAT_INC(tcps_rcvwinupd); 5585 tp->snd_wnd = tiwin; 5586 tp->snd_wl1 = th->th_seq; 5587 tp->snd_wl2 = th->th_ack; 5588 if (tp->snd_wnd > tp->max_sndwnd) 5589 tp->max_sndwnd = tp->snd_wnd; 5590 rack->r_wanted_output++; 5591 } else if (thflags & TH_ACK) { 5592 if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) { 5593 tp->snd_wnd = tiwin; 5594 tp->snd_wl1 = th->th_seq; 5595 tp->snd_wl2 = th->th_ack; 5596 } 5597 } 5598 if (tp->snd_wnd < ctf_outstanding(tp)) 5599 /* The peer collapsed the window */ 5600 rack_collapsed_window(rack); 5601 else if (rack->rc_has_collapsed) 5602 rack_un_collapse_window(rack); 5603 /* Was persist timer active and now we have window space? */ 5604 if ((rack->rc_in_persist != 0) && 5605 (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2), 5606 rack->r_ctl.rc_pace_min_segs))) { 5607 rack_exit_persist(tp, rack); 5608 tp->snd_nxt = tp->snd_max; 5609 /* Make sure we output to start the timer */ 5610 rack->r_wanted_output++; 5611 } 5612 /* Do we enter persists? */ 5613 if ((rack->rc_in_persist == 0) && 5614 (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) && 5615 TCPS_HAVEESTABLISHED(tp->t_state) && 5616 (tp->snd_max == tp->snd_una) && 5617 sbavail(&tp->t_inpcb->inp_socket->so_snd) && 5618 (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) { 5619 /* 5620 * Here the rwnd is less than 5621 * the pacing size, we are established, 5622 * nothing is outstanding, and there is 5623 * data to send. Enter persists. 5624 */ 5625 tp->snd_nxt = tp->snd_una; 5626 rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime); 5627 } 5628 if (tp->t_flags2 & TF2_DROP_AF_DATA) { 5629 m_freem(m); 5630 return (0); 5631 } 5632 /* 5633 * Process segments with URG. 5634 */ 5635 if ((thflags & TH_URG) && th->th_urp && 5636 TCPS_HAVERCVDFIN(tp->t_state) == 0) { 5637 /* 5638 * This is a kludge, but if we receive and accept random 5639 * urgent pointers, we'll crash in soreceive. It's hard to 5640 * imagine someone actually wanting to send this much urgent 5641 * data. 5642 */ 5643 SOCKBUF_LOCK(&so->so_rcv); 5644 if (th->th_urp + sbavail(&so->so_rcv) > sb_max) { 5645 th->th_urp = 0; /* XXX */ 5646 thflags &= ~TH_URG; /* XXX */ 5647 SOCKBUF_UNLOCK(&so->so_rcv); /* XXX */ 5648 goto dodata; /* XXX */ 5649 } 5650 /* 5651 * If this segment advances the known urgent pointer, then 5652 * mark the data stream. This should not happen in 5653 * CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since a 5654 * FIN has been received from the remote side. In these 5655 * states we ignore the URG. 5656 * 5657 * According to RFC961 (Assigned Protocols), the urgent 5658 * pointer points to the last octet of urgent data. We 5659 * continue, however, to consider it to indicate the first 5660 * octet of data past the urgent section as the original 5661 * spec states (in one of two places). 5662 */ 5663 if (SEQ_GT(th->th_seq + th->th_urp, tp->rcv_up)) { 5664 tp->rcv_up = th->th_seq + th->th_urp; 5665 so->so_oobmark = sbavail(&so->so_rcv) + 5666 (tp->rcv_up - tp->rcv_nxt) - 1; 5667 if (so->so_oobmark == 0) 5668 so->so_rcv.sb_state |= SBS_RCVATMARK; 5669 sohasoutofband(so); 5670 tp->t_oobflags &= ~(TCPOOB_HAVEDATA | TCPOOB_HADDATA); 5671 } 5672 SOCKBUF_UNLOCK(&so->so_rcv); 5673 /* 5674 * Remove out of band data so doesn't get presented to user. 5675 * This can happen independent of advancing the URG pointer, 5676 * but if two URG's are pending at once, some out-of-band 5677 * data may creep in... ick. 5678 */ 5679 if (th->th_urp <= (uint32_t) tlen && 5680 !(so->so_options & SO_OOBINLINE)) { 5681 /* hdr drop is delayed */ 5682 tcp_pulloutofband(so, th, m, drop_hdrlen); 5683 } 5684 } else { 5685 /* 5686 * If no out of band data is expected, pull receive urgent 5687 * pointer along with the receive window. 5688 */ 5689 if (SEQ_GT(tp->rcv_nxt, tp->rcv_up)) 5690 tp->rcv_up = tp->rcv_nxt; 5691 } 5692 dodata: /* XXX */ 5693 INP_WLOCK_ASSERT(tp->t_inpcb); 5694 5695 /* 5696 * Process the segment text, merging it into the TCP sequencing 5697 * queue, and arranging for acknowledgment of receipt if necessary. 5698 * This process logically involves adjusting tp->rcv_wnd as data is 5699 * presented to the user (this happens in tcp_usrreq.c, case 5700 * PRU_RCVD). If a FIN has already been received on this connection 5701 * then we just ignore the text. 5702 */ 5703 tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) && 5704 IS_FASTOPEN(tp->t_flags)); 5705 if ((tlen || (thflags & TH_FIN) || tfo_syn) && 5706 TCPS_HAVERCVDFIN(tp->t_state) == 0) { 5707 tcp_seq save_start = th->th_seq; 5708 tcp_seq save_rnxt = tp->rcv_nxt; 5709 int save_tlen = tlen; 5710 5711 m_adj(m, drop_hdrlen); /* delayed header drop */ 5712 /* 5713 * Insert segment which includes th into TCP reassembly 5714 * queue with control block tp. Set thflags to whether 5715 * reassembly now includes a segment with FIN. This handles 5716 * the common case inline (segment is the next to be 5717 * received on an established connection, and the queue is 5718 * empty), avoiding linkage into and removal from the queue 5719 * and repetition of various conversions. Set DELACK for 5720 * segments received in order, but ack immediately when 5721 * segments are out of order (so fast retransmit can work). 5722 */ 5723 if (th->th_seq == tp->rcv_nxt && 5724 SEGQ_EMPTY(tp) && 5725 (TCPS_HAVEESTABLISHED(tp->t_state) || 5726 tfo_syn)) { 5727 #ifdef NETFLIX_SB_LIMITS 5728 u_int mcnt, appended; 5729 5730 if (so->so_rcv.sb_shlim) { 5731 mcnt = m_memcnt(m); 5732 appended = 0; 5733 if (counter_fo_get(so->so_rcv.sb_shlim, mcnt, 5734 CFO_NOSLEEP, NULL) == false) { 5735 counter_u64_add(tcp_sb_shlim_fails, 1); 5736 m_freem(m); 5737 return (0); 5738 } 5739 } 5740 #endif 5741 if (DELAY_ACK(tp, tlen) || tfo_syn) { 5742 rack_timer_cancel(tp, rack, 5743 rack->r_ctl.rc_rcvtime, __LINE__); 5744 tp->t_flags |= TF_DELACK; 5745 } else { 5746 rack->r_wanted_output++; 5747 tp->t_flags |= TF_ACKNOW; 5748 } 5749 tp->rcv_nxt += tlen; 5750 thflags = th->th_flags & TH_FIN; 5751 TCPSTAT_ADD(tcps_rcvpack, nsegs); 5752 TCPSTAT_ADD(tcps_rcvbyte, tlen); 5753 SOCKBUF_LOCK(&so->so_rcv); 5754 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 5755 m_freem(m); 5756 } else 5757 #ifdef NETFLIX_SB_LIMITS 5758 appended = 5759 #endif 5760 sbappendstream_locked(&so->so_rcv, m, 0); 5761 /* NB: sorwakeup_locked() does an implicit unlock. */ 5762 sorwakeup_locked(so); 5763 #ifdef NETFLIX_SB_LIMITS 5764 if (so->so_rcv.sb_shlim && appended != mcnt) 5765 counter_fo_release(so->so_rcv.sb_shlim, 5766 mcnt - appended); 5767 #endif 5768 } else { 5769 /* 5770 * XXX: Due to the header drop above "th" is 5771 * theoretically invalid by now. Fortunately 5772 * m_adj() doesn't actually frees any mbufs when 5773 * trimming from the head. 5774 */ 5775 tcp_seq temp = save_start; 5776 thflags = tcp_reass(tp, th, &temp, &tlen, m); 5777 tp->t_flags |= TF_ACKNOW; 5778 } 5779 if ((tp->t_flags & TF_SACK_PERMIT) && (save_tlen > 0)) { 5780 if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) { 5781 /* 5782 * DSACK actually handled in the fastpath 5783 * above. 5784 */ 5785 tcp_update_sack_list(tp, save_start, 5786 save_start + save_tlen); 5787 } else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) { 5788 if ((tp->rcv_numsacks >= 1) && 5789 (tp->sackblks[0].end == save_start)) { 5790 /* 5791 * Partial overlap, recorded at todrop 5792 * above. 5793 */ 5794 tcp_update_sack_list(tp, 5795 tp->sackblks[0].start, 5796 tp->sackblks[0].end); 5797 } else { 5798 tcp_update_dsack_list(tp, save_start, 5799 save_start + save_tlen); 5800 } 5801 } else if (tlen >= save_tlen) { 5802 /* Update of sackblks. */ 5803 tcp_update_dsack_list(tp, save_start, 5804 save_start + save_tlen); 5805 } else if (tlen > 0) { 5806 tcp_update_dsack_list(tp, save_start, 5807 save_start + tlen); 5808 } 5809 } 5810 } else { 5811 m_freem(m); 5812 thflags &= ~TH_FIN; 5813 } 5814 5815 /* 5816 * If FIN is received ACK the FIN and let the user know that the 5817 * connection is closing. 5818 */ 5819 if (thflags & TH_FIN) { 5820 if (TCPS_HAVERCVDFIN(tp->t_state) == 0) { 5821 socantrcvmore(so); 5822 /* 5823 * If connection is half-synchronized (ie NEEDSYN 5824 * flag on) then delay ACK, so it may be piggybacked 5825 * when SYN is sent. Otherwise, since we received a 5826 * FIN then no more input can be expected, send ACK 5827 * now. 5828 */ 5829 if (tp->t_flags & TF_NEEDSYN) { 5830 rack_timer_cancel(tp, rack, 5831 rack->r_ctl.rc_rcvtime, __LINE__); 5832 tp->t_flags |= TF_DELACK; 5833 } else { 5834 tp->t_flags |= TF_ACKNOW; 5835 } 5836 tp->rcv_nxt++; 5837 } 5838 switch (tp->t_state) { 5839 5840 /* 5841 * In SYN_RECEIVED and ESTABLISHED STATES enter the 5842 * CLOSE_WAIT state. 5843 */ 5844 case TCPS_SYN_RECEIVED: 5845 tp->t_starttime = ticks; 5846 /* FALLTHROUGH */ 5847 case TCPS_ESTABLISHED: 5848 rack_timer_cancel(tp, rack, 5849 rack->r_ctl.rc_rcvtime, __LINE__); 5850 tcp_state_change(tp, TCPS_CLOSE_WAIT); 5851 break; 5852 5853 /* 5854 * If still in FIN_WAIT_1 STATE FIN has not been 5855 * acked so enter the CLOSING state. 5856 */ 5857 case TCPS_FIN_WAIT_1: 5858 rack_timer_cancel(tp, rack, 5859 rack->r_ctl.rc_rcvtime, __LINE__); 5860 tcp_state_change(tp, TCPS_CLOSING); 5861 break; 5862 5863 /* 5864 * In FIN_WAIT_2 state enter the TIME_WAIT state, 5865 * starting the time-wait timer, turning off the 5866 * other standard timers. 5867 */ 5868 case TCPS_FIN_WAIT_2: 5869 rack_timer_cancel(tp, rack, 5870 rack->r_ctl.rc_rcvtime, __LINE__); 5871 tcp_twstart(tp); 5872 return (1); 5873 } 5874 } 5875 /* 5876 * Return any desired output. 5877 */ 5878 if ((tp->t_flags & TF_ACKNOW) || 5879 (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) { 5880 rack->r_wanted_output++; 5881 } 5882 INP_WLOCK_ASSERT(tp->t_inpcb); 5883 return (0); 5884 } 5885 5886 /* 5887 * Here nothing is really faster, its just that we 5888 * have broken out the fast-data path also just like 5889 * the fast-ack. 5890 */ 5891 static int 5892 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so, 5893 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 5894 uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos) 5895 { 5896 int32_t nsegs; 5897 int32_t newsize = 0; /* automatic sockbuf scaling */ 5898 struct tcp_rack *rack; 5899 #ifdef NETFLIX_SB_LIMITS 5900 u_int mcnt, appended; 5901 #endif 5902 #ifdef TCPDEBUG 5903 /* 5904 * The size of tcp_saveipgen must be the size of the max ip header, 5905 * now IPv6. 5906 */ 5907 u_char tcp_saveipgen[IP6_HDR_LEN]; 5908 struct tcphdr tcp_savetcp; 5909 short ostate = 0; 5910 5911 #endif 5912 /* 5913 * If last ACK falls within this segment's sequence numbers, record 5914 * the timestamp. NOTE that the test is modified according to the 5915 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26). 5916 */ 5917 if (__predict_false(th->th_seq != tp->rcv_nxt)) { 5918 return (0); 5919 } 5920 if (__predict_false(tp->snd_nxt != tp->snd_max)) { 5921 return (0); 5922 } 5923 if (tiwin && tiwin != tp->snd_wnd) { 5924 return (0); 5925 } 5926 if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) { 5927 return (0); 5928 } 5929 if (__predict_false((to->to_flags & TOF_TS) && 5930 (TSTMP_LT(to->to_tsval, tp->ts_recent)))) { 5931 return (0); 5932 } 5933 if (__predict_false((th->th_ack != tp->snd_una))) { 5934 return (0); 5935 } 5936 if (__predict_false(tlen > sbspace(&so->so_rcv))) { 5937 return (0); 5938 } 5939 if ((to->to_flags & TOF_TS) != 0 && 5940 SEQ_LEQ(th->th_seq, tp->last_ack_sent)) { 5941 tp->ts_recent_age = tcp_ts_getticks(); 5942 tp->ts_recent = to->to_tsval; 5943 } 5944 rack = (struct tcp_rack *)tp->t_fb_ptr; 5945 /* 5946 * This is a pure, in-sequence data packet with nothing on the 5947 * reassembly queue and we have enough buffer space to take it. 5948 */ 5949 nsegs = max(1, m->m_pkthdr.lro_nsegs); 5950 5951 #ifdef NETFLIX_SB_LIMITS 5952 if (so->so_rcv.sb_shlim) { 5953 mcnt = m_memcnt(m); 5954 appended = 0; 5955 if (counter_fo_get(so->so_rcv.sb_shlim, mcnt, 5956 CFO_NOSLEEP, NULL) == false) { 5957 counter_u64_add(tcp_sb_shlim_fails, 1); 5958 m_freem(m); 5959 return (1); 5960 } 5961 } 5962 #endif 5963 /* Clean receiver SACK report if present */ 5964 if (tp->rcv_numsacks) 5965 tcp_clean_sackreport(tp); 5966 TCPSTAT_INC(tcps_preddat); 5967 tp->rcv_nxt += tlen; 5968 /* 5969 * Pull snd_wl1 up to prevent seq wrap relative to th_seq. 5970 */ 5971 tp->snd_wl1 = th->th_seq; 5972 /* 5973 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt. 5974 */ 5975 tp->rcv_up = tp->rcv_nxt; 5976 TCPSTAT_ADD(tcps_rcvpack, nsegs); 5977 TCPSTAT_ADD(tcps_rcvbyte, tlen); 5978 #ifdef TCPDEBUG 5979 if (so->so_options & SO_DEBUG) 5980 tcp_trace(TA_INPUT, ostate, tp, 5981 (void *)tcp_saveipgen, &tcp_savetcp, 0); 5982 #endif 5983 newsize = tcp_autorcvbuf(m, th, so, tp, tlen); 5984 5985 /* Add data to socket buffer. */ 5986 SOCKBUF_LOCK(&so->so_rcv); 5987 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 5988 m_freem(m); 5989 } else { 5990 /* 5991 * Set new socket buffer size. Give up when limit is 5992 * reached. 5993 */ 5994 if (newsize) 5995 if (!sbreserve_locked(&so->so_rcv, 5996 newsize, so, NULL)) 5997 so->so_rcv.sb_flags &= ~SB_AUTOSIZE; 5998 m_adj(m, drop_hdrlen); /* delayed header drop */ 5999 #ifdef NETFLIX_SB_LIMITS 6000 appended = 6001 #endif 6002 sbappendstream_locked(&so->so_rcv, m, 0); 6003 ctf_calc_rwin(so, tp); 6004 } 6005 /* NB: sorwakeup_locked() does an implicit unlock. */ 6006 sorwakeup_locked(so); 6007 #ifdef NETFLIX_SB_LIMITS 6008 if (so->so_rcv.sb_shlim && mcnt != appended) 6009 counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended); 6010 #endif 6011 if (DELAY_ACK(tp, tlen)) { 6012 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 6013 tp->t_flags |= TF_DELACK; 6014 } else { 6015 tp->t_flags |= TF_ACKNOW; 6016 rack->r_wanted_output++; 6017 } 6018 if ((tp->snd_una == tp->snd_max) && rack_use_sack_filter) 6019 sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una); 6020 return (1); 6021 } 6022 6023 /* 6024 * This subfunction is used to try to highly optimize the 6025 * fast path. We again allow window updates that are 6026 * in sequence to remain in the fast-path. We also add 6027 * in the __predict's to attempt to help the compiler. 6028 * Note that if we return a 0, then we can *not* process 6029 * it and the caller should push the packet into the 6030 * slow-path. 6031 */ 6032 static int 6033 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so, 6034 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6035 uint32_t tiwin, int32_t nxt_pkt, uint32_t cts, uint8_t iptos) 6036 { 6037 int32_t acked; 6038 int32_t nsegs; 6039 6040 #ifdef TCPDEBUG 6041 /* 6042 * The size of tcp_saveipgen must be the size of the max ip header, 6043 * now IPv6. 6044 */ 6045 u_char tcp_saveipgen[IP6_HDR_LEN]; 6046 struct tcphdr tcp_savetcp; 6047 short ostate = 0; 6048 6049 #endif 6050 struct tcp_rack *rack; 6051 6052 if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) { 6053 /* Old ack, behind (or duplicate to) the last one rcv'd */ 6054 return (0); 6055 } 6056 if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) { 6057 /* Above what we have sent? */ 6058 return (0); 6059 } 6060 if (__predict_false(tp->snd_nxt != tp->snd_max)) { 6061 /* We are retransmitting */ 6062 return (0); 6063 } 6064 if (__predict_false(tiwin == 0)) { 6065 /* zero window */ 6066 return (0); 6067 } 6068 if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) { 6069 /* We need a SYN or a FIN, unlikely.. */ 6070 return (0); 6071 } 6072 if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) { 6073 /* Timestamp is behind .. old ack with seq wrap? */ 6074 return (0); 6075 } 6076 if (__predict_false(IN_RECOVERY(tp->t_flags))) { 6077 /* Still recovering */ 6078 return (0); 6079 } 6080 rack = (struct tcp_rack *)tp->t_fb_ptr; 6081 if (rack->r_ctl.rc_sacked) { 6082 /* We have sack holes on our scoreboard */ 6083 return (0); 6084 } 6085 /* Ok if we reach here, we can process a fast-ack */ 6086 nsegs = max(1, m->m_pkthdr.lro_nsegs); 6087 rack_log_ack(tp, to, th); 6088 /* 6089 * We made progress, clear the tlp 6090 * out flag so we could start a TLP 6091 * again. 6092 */ 6093 rack->r_ctl.rc_tlp_rtx_out = 0; 6094 /* Did the window get updated? */ 6095 if (tiwin != tp->snd_wnd) { 6096 tp->snd_wnd = tiwin; 6097 tp->snd_wl1 = th->th_seq; 6098 if (tp->snd_wnd > tp->max_sndwnd) 6099 tp->max_sndwnd = tp->snd_wnd; 6100 } 6101 /* Do we exit persists? */ 6102 if ((rack->rc_in_persist != 0) && 6103 (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2), 6104 rack->r_ctl.rc_pace_min_segs))) { 6105 rack_exit_persist(tp, rack); 6106 } 6107 /* Do we enter persists? */ 6108 if ((rack->rc_in_persist == 0) && 6109 (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) && 6110 TCPS_HAVEESTABLISHED(tp->t_state) && 6111 (tp->snd_max == tp->snd_una) && 6112 sbavail(&tp->t_inpcb->inp_socket->so_snd) && 6113 (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) { 6114 /* 6115 * Here the rwnd is less than 6116 * the pacing size, we are established, 6117 * nothing is outstanding, and there is 6118 * data to send. Enter persists. 6119 */ 6120 tp->snd_nxt = tp->snd_una; 6121 rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime); 6122 } 6123 /* 6124 * If last ACK falls within this segment's sequence numbers, record 6125 * the timestamp. NOTE that the test is modified according to the 6126 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26). 6127 */ 6128 if ((to->to_flags & TOF_TS) != 0 && 6129 SEQ_LEQ(th->th_seq, tp->last_ack_sent)) { 6130 tp->ts_recent_age = tcp_ts_getticks(); 6131 tp->ts_recent = to->to_tsval; 6132 } 6133 /* 6134 * This is a pure ack for outstanding data. 6135 */ 6136 TCPSTAT_INC(tcps_predack); 6137 6138 /* 6139 * "bad retransmit" recovery. 6140 */ 6141 if (tp->t_flags & TF_PREVVALID) { 6142 tp->t_flags &= ~TF_PREVVALID; 6143 if (tp->t_rxtshift == 1 && 6144 (int)(ticks - tp->t_badrxtwin) < 0) 6145 rack_cong_signal(tp, th, CC_RTO_ERR); 6146 } 6147 /* 6148 * Recalculate the transmit timer / rtt. 6149 * 6150 * Some boxes send broken timestamp replies during the SYN+ACK 6151 * phase, ignore timestamps of 0 or we could calculate a huge RTT 6152 * and blow up the retransmit timer. 6153 */ 6154 acked = BYTES_THIS_ACK(tp, th); 6155 6156 #ifdef TCP_HHOOK 6157 /* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */ 6158 hhook_run_tcp_est_in(tp, th, to); 6159 #endif 6160 6161 TCPSTAT_ADD(tcps_rcvackpack, nsegs); 6162 TCPSTAT_ADD(tcps_rcvackbyte, acked); 6163 sbdrop(&so->so_snd, acked); 6164 /* 6165 * Let the congestion control algorithm update congestion control 6166 * related information. This typically means increasing the 6167 * congestion window. 6168 */ 6169 rack_ack_received(tp, rack, th, nsegs, CC_ACK, 0); 6170 6171 tp->snd_una = th->th_ack; 6172 if (tp->snd_wnd < ctf_outstanding(tp)) { 6173 /* The peer collapsed the window */ 6174 rack_collapsed_window(rack); 6175 } else if (rack->rc_has_collapsed) 6176 rack_un_collapse_window(rack); 6177 6178 /* 6179 * Pull snd_wl2 up to prevent seq wrap relative to th_ack. 6180 */ 6181 tp->snd_wl2 = th->th_ack; 6182 tp->t_dupacks = 0; 6183 m_freem(m); 6184 /* ND6_HINT(tp); *//* Some progress has been made. */ 6185 6186 /* 6187 * If all outstanding data are acked, stop retransmit timer, 6188 * otherwise restart timer using current (possibly backed-off) 6189 * value. If process is waiting for space, wakeup/selwakeup/signal. 6190 * If data are ready to send, let tcp_output decide between more 6191 * output or persist. 6192 */ 6193 #ifdef TCPDEBUG 6194 if (so->so_options & SO_DEBUG) 6195 tcp_trace(TA_INPUT, ostate, tp, 6196 (void *)tcp_saveipgen, 6197 &tcp_savetcp, 0); 6198 #endif 6199 if (tp->snd_una == tp->snd_max) { 6200 rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__); 6201 if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0) 6202 tp->t_acktime = 0; 6203 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 6204 } 6205 /* Wake up the socket if we have room to write more */ 6206 sowwakeup(so); 6207 if (sbavail(&so->so_snd)) { 6208 rack->r_wanted_output++; 6209 } 6210 return (1); 6211 } 6212 6213 /* 6214 * Return value of 1, the TCB is unlocked and most 6215 * likely gone, return value of 0, the TCP is still 6216 * locked. 6217 */ 6218 static int 6219 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so, 6220 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6221 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t tos) 6222 { 6223 int32_t ret_val = 0; 6224 int32_t todrop; 6225 int32_t ourfinisacked = 0; 6226 struct tcp_rack *rack; 6227 6228 ctf_calc_rwin(so, tp); 6229 /* 6230 * If the state is SYN_SENT: if seg contains an ACK, but not for our 6231 * SYN, drop the input. if seg contains a RST, then drop the 6232 * connection. if seg does not contain SYN, then drop it. Otherwise 6233 * this is an acceptable SYN segment initialize tp->rcv_nxt and 6234 * tp->irs if seg contains ack then advance tp->snd_una if seg 6235 * contains an ECE and ECN support is enabled, the stream is ECN 6236 * capable. if SYN has been acked change to ESTABLISHED else 6237 * SYN_RCVD state arrange for segment to be acked (eventually) 6238 * continue processing rest of data/controls, beginning with URG 6239 */ 6240 if ((thflags & TH_ACK) && 6241 (SEQ_LEQ(th->th_ack, tp->iss) || 6242 SEQ_GT(th->th_ack, tp->snd_max))) { 6243 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6244 return (1); 6245 } 6246 if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) { 6247 TCP_PROBE5(connect__refused, NULL, tp, 6248 mtod(m, const char *), tp, th); 6249 tp = tcp_drop(tp, ECONNREFUSED); 6250 ctf_do_drop(m, tp); 6251 return (1); 6252 } 6253 if (thflags & TH_RST) { 6254 ctf_do_drop(m, tp); 6255 return (1); 6256 } 6257 if (!(thflags & TH_SYN)) { 6258 ctf_do_drop(m, tp); 6259 return (1); 6260 } 6261 tp->irs = th->th_seq; 6262 tcp_rcvseqinit(tp); 6263 rack = (struct tcp_rack *)tp->t_fb_ptr; 6264 if (thflags & TH_ACK) { 6265 int tfo_partial = 0; 6266 6267 TCPSTAT_INC(tcps_connects); 6268 soisconnected(so); 6269 #ifdef MAC 6270 mac_socketpeer_set_from_mbuf(m, so); 6271 #endif 6272 /* Do window scaling on this connection? */ 6273 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) == 6274 (TF_RCVD_SCALE | TF_REQ_SCALE)) { 6275 tp->rcv_scale = tp->request_r_scale; 6276 } 6277 tp->rcv_adv += min(tp->rcv_wnd, 6278 TCP_MAXWIN << tp->rcv_scale); 6279 /* 6280 * If not all the data that was sent in the TFO SYN 6281 * has been acked, resend the remainder right away. 6282 */ 6283 if (IS_FASTOPEN(tp->t_flags) && 6284 (tp->snd_una != tp->snd_max)) { 6285 tp->snd_nxt = th->th_ack; 6286 tfo_partial = 1; 6287 } 6288 /* 6289 * If there's data, delay ACK; if there's also a FIN ACKNOW 6290 * will be turned on later. 6291 */ 6292 if (DELAY_ACK(tp, tlen) && tlen != 0 && (tfo_partial == 0)) { 6293 rack_timer_cancel(tp, rack, 6294 rack->r_ctl.rc_rcvtime, __LINE__); 6295 tp->t_flags |= TF_DELACK; 6296 } else { 6297 rack->r_wanted_output++; 6298 tp->t_flags |= TF_ACKNOW; 6299 } 6300 6301 if (((thflags & (TH_CWR | TH_ECE)) == TH_ECE) && 6302 (V_tcp_do_ecn == 1)) { 6303 tp->t_flags2 |= TF2_ECN_PERMIT; 6304 TCPSTAT_INC(tcps_ecn_shs); 6305 } 6306 if (SEQ_GT(th->th_ack, tp->snd_una)) { 6307 /* 6308 * We advance snd_una for the 6309 * fast open case. If th_ack is 6310 * acknowledging data beyond 6311 * snd_una we can't just call 6312 * ack-processing since the 6313 * data stream in our send-map 6314 * will start at snd_una + 1 (one 6315 * beyond the SYN). If its just 6316 * equal we don't need to do that 6317 * and there is no send_map. 6318 */ 6319 tp->snd_una++; 6320 } 6321 /* 6322 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions: 6323 * SYN_SENT --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1 6324 */ 6325 tp->t_starttime = ticks; 6326 if (tp->t_flags & TF_NEEDFIN) { 6327 tcp_state_change(tp, TCPS_FIN_WAIT_1); 6328 tp->t_flags &= ~TF_NEEDFIN; 6329 thflags &= ~TH_SYN; 6330 } else { 6331 tcp_state_change(tp, TCPS_ESTABLISHED); 6332 TCP_PROBE5(connect__established, NULL, tp, 6333 mtod(m, const char *), tp, th); 6334 cc_conn_init(tp); 6335 } 6336 } else { 6337 /* 6338 * Received initial SYN in SYN-SENT[*] state => simultaneous 6339 * open. If segment contains CC option and there is a 6340 * cached CC, apply TAO test. If it succeeds, connection is * 6341 * half-synchronized. Otherwise, do 3-way handshake: 6342 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If 6343 * there was no CC option, clear cached CC value. 6344 */ 6345 tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN); 6346 tcp_state_change(tp, TCPS_SYN_RECEIVED); 6347 } 6348 INP_WLOCK_ASSERT(tp->t_inpcb); 6349 /* 6350 * Advance th->th_seq to correspond to first data byte. If data, 6351 * trim to stay within window, dropping FIN if necessary. 6352 */ 6353 th->th_seq++; 6354 if (tlen > tp->rcv_wnd) { 6355 todrop = tlen - tp->rcv_wnd; 6356 m_adj(m, -todrop); 6357 tlen = tp->rcv_wnd; 6358 thflags &= ~TH_FIN; 6359 TCPSTAT_INC(tcps_rcvpackafterwin); 6360 TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop); 6361 } 6362 tp->snd_wl1 = th->th_seq - 1; 6363 tp->rcv_up = th->th_seq; 6364 /* 6365 * Client side of transaction: already sent SYN and data. If the 6366 * remote host used T/TCP to validate the SYN, our data will be 6367 * ACK'd; if so, enter normal data segment processing in the middle 6368 * of step 5, ack processing. Otherwise, goto step 6. 6369 */ 6370 if (thflags & TH_ACK) { 6371 /* For syn-sent we need to possibly update the rtt */ 6372 if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) { 6373 uint32_t t; 6374 6375 t = tcp_ts_getticks() - to->to_tsecr; 6376 if (!tp->t_rttlow || tp->t_rttlow > t) 6377 tp->t_rttlow = t; 6378 tcp_rack_xmit_timer(rack, t + 1); 6379 tcp_rack_xmit_timer_commit(rack, tp); 6380 } 6381 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) 6382 return (ret_val); 6383 /* We may have changed to FIN_WAIT_1 above */ 6384 if (tp->t_state == TCPS_FIN_WAIT_1) { 6385 /* 6386 * In FIN_WAIT_1 STATE in addition to the processing 6387 * for the ESTABLISHED state if our FIN is now 6388 * acknowledged then enter FIN_WAIT_2. 6389 */ 6390 if (ourfinisacked) { 6391 /* 6392 * If we can't receive any more data, then 6393 * closing user can proceed. Starting the 6394 * timer is contrary to the specification, 6395 * but if we don't get a FIN we'll hang 6396 * forever. 6397 * 6398 * XXXjl: we should release the tp also, and 6399 * use a compressed state. 6400 */ 6401 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 6402 soisdisconnected(so); 6403 tcp_timer_activate(tp, TT_2MSL, 6404 (tcp_fast_finwait2_recycle ? 6405 tcp_finwait2_timeout : 6406 TP_MAXIDLE(tp))); 6407 } 6408 tcp_state_change(tp, TCPS_FIN_WAIT_2); 6409 } 6410 } 6411 } 6412 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6413 tiwin, thflags, nxt_pkt)); 6414 } 6415 6416 /* 6417 * Return value of 1, the TCB is unlocked and most 6418 * likely gone, return value of 0, the TCP is still 6419 * locked. 6420 */ 6421 static int 6422 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so, 6423 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6424 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 6425 { 6426 struct tcp_rack *rack; 6427 int32_t ret_val = 0; 6428 int32_t ourfinisacked = 0; 6429 6430 ctf_calc_rwin(so, tp); 6431 if ((thflags & TH_ACK) && 6432 (SEQ_LEQ(th->th_ack, tp->snd_una) || 6433 SEQ_GT(th->th_ack, tp->snd_max))) { 6434 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6435 return (1); 6436 } 6437 rack = (struct tcp_rack *)tp->t_fb_ptr; 6438 if (IS_FASTOPEN(tp->t_flags)) { 6439 /* 6440 * When a TFO connection is in SYN_RECEIVED, the 6441 * only valid packets are the initial SYN, a 6442 * retransmit/copy of the initial SYN (possibly with 6443 * a subset of the original data), a valid ACK, a 6444 * FIN, or a RST. 6445 */ 6446 if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) { 6447 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6448 return (1); 6449 } else if (thflags & TH_SYN) { 6450 /* non-initial SYN is ignored */ 6451 if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) || 6452 (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) || 6453 (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) { 6454 ctf_do_drop(m, NULL); 6455 return (0); 6456 } 6457 } else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) { 6458 ctf_do_drop(m, NULL); 6459 return (0); 6460 } 6461 } 6462 if ((thflags & TH_RST) || 6463 (tp->t_fin_is_rst && (thflags & TH_FIN))) 6464 return (ctf_process_rst(m, th, so, tp)); 6465 /* 6466 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 6467 * it's less than ts_recent, drop it. 6468 */ 6469 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 6470 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 6471 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 6472 return (ret_val); 6473 } 6474 /* 6475 * In the SYN-RECEIVED state, validate that the packet belongs to 6476 * this connection before trimming the data to fit the receive 6477 * window. Check the sequence number versus IRS since we know the 6478 * sequence numbers haven't wrapped. This is a partial fix for the 6479 * "LAND" DoS attack. 6480 */ 6481 if (SEQ_LT(th->th_seq, tp->irs)) { 6482 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6483 return (1); 6484 } 6485 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 6486 return (ret_val); 6487 } 6488 /* 6489 * If last ACK falls within this segment's sequence numbers, record 6490 * its timestamp. NOTE: 1) That the test incorporates suggestions 6491 * from the latest proposal of the tcplw@cray.com list (Braden 6492 * 1993/04/26). 2) That updating only on newer timestamps interferes 6493 * with our earlier PAWS tests, so this check should be solely 6494 * predicated on the sequence space of this segment. 3) That we 6495 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 6496 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 6497 * SEG.Len, This modified check allows us to overcome RFC1323's 6498 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 6499 * p.869. In such cases, we can still calculate the RTT correctly 6500 * when RCV.NXT == Last.ACK.Sent. 6501 */ 6502 if ((to->to_flags & TOF_TS) != 0 && 6503 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 6504 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 6505 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 6506 tp->ts_recent_age = tcp_ts_getticks(); 6507 tp->ts_recent = to->to_tsval; 6508 } 6509 tp->snd_wnd = tiwin; 6510 /* 6511 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 6512 * is on (half-synchronized state), then queue data for later 6513 * processing; else drop segment and return. 6514 */ 6515 if ((thflags & TH_ACK) == 0) { 6516 if (IS_FASTOPEN(tp->t_flags)) { 6517 cc_conn_init(tp); 6518 } 6519 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6520 tiwin, thflags, nxt_pkt)); 6521 } 6522 TCPSTAT_INC(tcps_connects); 6523 soisconnected(so); 6524 /* Do window scaling? */ 6525 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) == 6526 (TF_RCVD_SCALE | TF_REQ_SCALE)) { 6527 tp->rcv_scale = tp->request_r_scale; 6528 } 6529 /* 6530 * Make transitions: SYN-RECEIVED -> ESTABLISHED SYN-RECEIVED* -> 6531 * FIN-WAIT-1 6532 */ 6533 tp->t_starttime = ticks; 6534 if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) { 6535 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 6536 tp->t_tfo_pending = NULL; 6537 6538 /* 6539 * Account for the ACK of our SYN prior to 6540 * regular ACK processing below. 6541 */ 6542 tp->snd_una++; 6543 } 6544 if (tp->t_flags & TF_NEEDFIN) { 6545 tcp_state_change(tp, TCPS_FIN_WAIT_1); 6546 tp->t_flags &= ~TF_NEEDFIN; 6547 } else { 6548 tcp_state_change(tp, TCPS_ESTABLISHED); 6549 TCP_PROBE5(accept__established, NULL, tp, 6550 mtod(m, const char *), tp, th); 6551 /* 6552 * TFO connections call cc_conn_init() during SYN 6553 * processing. Calling it again here for such connections 6554 * is not harmless as it would undo the snd_cwnd reduction 6555 * that occurs when a TFO SYN|ACK is retransmitted. 6556 */ 6557 if (!IS_FASTOPEN(tp->t_flags)) 6558 cc_conn_init(tp); 6559 } 6560 /* 6561 * If segment contains data or ACK, will call tcp_reass() later; if 6562 * not, do so now to pass queued data to user. 6563 */ 6564 if (tlen == 0 && (thflags & TH_FIN) == 0) 6565 (void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0, 6566 (struct mbuf *)0); 6567 tp->snd_wl1 = th->th_seq - 1; 6568 /* For syn-recv we need to possibly update the rtt */ 6569 if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) { 6570 uint32_t t; 6571 6572 t = tcp_ts_getticks() - to->to_tsecr; 6573 if (!tp->t_rttlow || tp->t_rttlow > t) 6574 tp->t_rttlow = t; 6575 tcp_rack_xmit_timer(rack, t + 1); 6576 tcp_rack_xmit_timer_commit(rack, tp); 6577 } 6578 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) { 6579 return (ret_val); 6580 } 6581 if (tp->t_state == TCPS_FIN_WAIT_1) { 6582 /* We could have went to FIN_WAIT_1 (or EST) above */ 6583 /* 6584 * In FIN_WAIT_1 STATE in addition to the processing for the 6585 * ESTABLISHED state if our FIN is now acknowledged then 6586 * enter FIN_WAIT_2. 6587 */ 6588 if (ourfinisacked) { 6589 /* 6590 * If we can't receive any more data, then closing 6591 * user can proceed. Starting the timer is contrary 6592 * to the specification, but if we don't get a FIN 6593 * we'll hang forever. 6594 * 6595 * XXXjl: we should release the tp also, and use a 6596 * compressed state. 6597 */ 6598 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 6599 soisdisconnected(so); 6600 tcp_timer_activate(tp, TT_2MSL, 6601 (tcp_fast_finwait2_recycle ? 6602 tcp_finwait2_timeout : 6603 TP_MAXIDLE(tp))); 6604 } 6605 tcp_state_change(tp, TCPS_FIN_WAIT_2); 6606 } 6607 } 6608 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6609 tiwin, thflags, nxt_pkt)); 6610 } 6611 6612 /* 6613 * Return value of 1, the TCB is unlocked and most 6614 * likely gone, return value of 0, the TCP is still 6615 * locked. 6616 */ 6617 static int 6618 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so, 6619 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6620 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 6621 { 6622 int32_t ret_val = 0; 6623 6624 /* 6625 * Header prediction: check for the two common cases of a 6626 * uni-directional data xfer. If the packet has no control flags, 6627 * is in-sequence, the window didn't change and we're not 6628 * retransmitting, it's a candidate. If the length is zero and the 6629 * ack moved forward, we're the sender side of the xfer. Just free 6630 * the data acked & wake any higher level process that was blocked 6631 * waiting for space. If the length is non-zero and the ack didn't 6632 * move, we're the receiver side. If we're getting packets in-order 6633 * (the reassembly queue is empty), add the data toc The socket 6634 * buffer and note that we need a delayed ack. Make sure that the 6635 * hidden state-flags are also off. Since we check for 6636 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN. 6637 */ 6638 if (__predict_true(((to->to_flags & TOF_SACK) == 0)) && 6639 __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_URG | TH_ACK)) == TH_ACK) && 6640 __predict_true(SEGQ_EMPTY(tp)) && 6641 __predict_true(th->th_seq == tp->rcv_nxt)) { 6642 struct tcp_rack *rack; 6643 6644 rack = (struct tcp_rack *)tp->t_fb_ptr; 6645 if (tlen == 0) { 6646 if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen, 6647 tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime, iptos)) { 6648 return (0); 6649 } 6650 } else { 6651 if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen, 6652 tiwin, nxt_pkt, iptos)) { 6653 return (0); 6654 } 6655 } 6656 } 6657 ctf_calc_rwin(so, tp); 6658 6659 if ((thflags & TH_RST) || 6660 (tp->t_fin_is_rst && (thflags & TH_FIN))) 6661 return (ctf_process_rst(m, th, so, tp)); 6662 6663 /* 6664 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 6665 * synchronized state. 6666 */ 6667 if (thflags & TH_SYN) { 6668 ctf_challenge_ack(m, th, tp, &ret_val); 6669 return (ret_val); 6670 } 6671 /* 6672 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 6673 * it's less than ts_recent, drop it. 6674 */ 6675 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 6676 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 6677 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 6678 return (ret_val); 6679 } 6680 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 6681 return (ret_val); 6682 } 6683 /* 6684 * If last ACK falls within this segment's sequence numbers, record 6685 * its timestamp. NOTE: 1) That the test incorporates suggestions 6686 * from the latest proposal of the tcplw@cray.com list (Braden 6687 * 1993/04/26). 2) That updating only on newer timestamps interferes 6688 * with our earlier PAWS tests, so this check should be solely 6689 * predicated on the sequence space of this segment. 3) That we 6690 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 6691 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 6692 * SEG.Len, This modified check allows us to overcome RFC1323's 6693 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 6694 * p.869. In such cases, we can still calculate the RTT correctly 6695 * when RCV.NXT == Last.ACK.Sent. 6696 */ 6697 if ((to->to_flags & TOF_TS) != 0 && 6698 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 6699 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 6700 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 6701 tp->ts_recent_age = tcp_ts_getticks(); 6702 tp->ts_recent = to->to_tsval; 6703 } 6704 /* 6705 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 6706 * is on (half-synchronized state), then queue data for later 6707 * processing; else drop segment and return. 6708 */ 6709 if ((thflags & TH_ACK) == 0) { 6710 if (tp->t_flags & TF_NEEDSYN) { 6711 6712 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6713 tiwin, thflags, nxt_pkt)); 6714 6715 } else if (tp->t_flags & TF_ACKNOW) { 6716 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 6717 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 6718 return (ret_val); 6719 } else { 6720 ctf_do_drop(m, NULL); 6721 return (0); 6722 } 6723 } 6724 /* 6725 * Ack processing. 6726 */ 6727 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) { 6728 return (ret_val); 6729 } 6730 if (sbavail(&so->so_snd)) { 6731 if (rack_progress_timeout_check(tp)) { 6732 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 6733 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6734 return (1); 6735 } 6736 } 6737 /* State changes only happen in rack_process_data() */ 6738 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6739 tiwin, thflags, nxt_pkt)); 6740 } 6741 6742 /* 6743 * Return value of 1, the TCB is unlocked and most 6744 * likely gone, return value of 0, the TCP is still 6745 * locked. 6746 */ 6747 static int 6748 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so, 6749 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6750 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 6751 { 6752 int32_t ret_val = 0; 6753 6754 ctf_calc_rwin(so, tp); 6755 if ((thflags & TH_RST) || 6756 (tp->t_fin_is_rst && (thflags & TH_FIN))) 6757 return (ctf_process_rst(m, th, so, tp)); 6758 /* 6759 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 6760 * synchronized state. 6761 */ 6762 if (thflags & TH_SYN) { 6763 ctf_challenge_ack(m, th, tp, &ret_val); 6764 return (ret_val); 6765 } 6766 /* 6767 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 6768 * it's less than ts_recent, drop it. 6769 */ 6770 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 6771 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 6772 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 6773 return (ret_val); 6774 } 6775 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 6776 return (ret_val); 6777 } 6778 /* 6779 * If last ACK falls within this segment's sequence numbers, record 6780 * its timestamp. NOTE: 1) That the test incorporates suggestions 6781 * from the latest proposal of the tcplw@cray.com list (Braden 6782 * 1993/04/26). 2) That updating only on newer timestamps interferes 6783 * with our earlier PAWS tests, so this check should be solely 6784 * predicated on the sequence space of this segment. 3) That we 6785 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 6786 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 6787 * SEG.Len, This modified check allows us to overcome RFC1323's 6788 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 6789 * p.869. In such cases, we can still calculate the RTT correctly 6790 * when RCV.NXT == Last.ACK.Sent. 6791 */ 6792 if ((to->to_flags & TOF_TS) != 0 && 6793 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 6794 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 6795 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 6796 tp->ts_recent_age = tcp_ts_getticks(); 6797 tp->ts_recent = to->to_tsval; 6798 } 6799 /* 6800 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 6801 * is on (half-synchronized state), then queue data for later 6802 * processing; else drop segment and return. 6803 */ 6804 if ((thflags & TH_ACK) == 0) { 6805 if (tp->t_flags & TF_NEEDSYN) { 6806 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6807 tiwin, thflags, nxt_pkt)); 6808 6809 } else if (tp->t_flags & TF_ACKNOW) { 6810 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 6811 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 6812 return (ret_val); 6813 } else { 6814 ctf_do_drop(m, NULL); 6815 return (0); 6816 } 6817 } 6818 /* 6819 * Ack processing. 6820 */ 6821 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) { 6822 return (ret_val); 6823 } 6824 if (sbavail(&so->so_snd)) { 6825 if (rack_progress_timeout_check(tp)) { 6826 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 6827 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6828 return (1); 6829 } 6830 } 6831 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6832 tiwin, thflags, nxt_pkt)); 6833 } 6834 6835 static int 6836 rack_check_data_after_close(struct mbuf *m, 6837 struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so) 6838 { 6839 struct tcp_rack *rack; 6840 6841 rack = (struct tcp_rack *)tp->t_fb_ptr; 6842 if (rack->rc_allow_data_af_clo == 0) { 6843 close_now: 6844 tp = tcp_close(tp); 6845 TCPSTAT_INC(tcps_rcvafterclose); 6846 ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen)); 6847 return (1); 6848 } 6849 if (sbavail(&so->so_snd) == 0) 6850 goto close_now; 6851 /* Ok we allow data that is ignored and a followup reset */ 6852 tp->rcv_nxt = th->th_seq + *tlen; 6853 tp->t_flags2 |= TF2_DROP_AF_DATA; 6854 rack->r_wanted_output = 1; 6855 *tlen = 0; 6856 return (0); 6857 } 6858 6859 /* 6860 * Return value of 1, the TCB is unlocked and most 6861 * likely gone, return value of 0, the TCP is still 6862 * locked. 6863 */ 6864 static int 6865 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so, 6866 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6867 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 6868 { 6869 int32_t ret_val = 0; 6870 int32_t ourfinisacked = 0; 6871 6872 ctf_calc_rwin(so, tp); 6873 6874 if ((thflags & TH_RST) || 6875 (tp->t_fin_is_rst && (thflags & TH_FIN))) 6876 return (ctf_process_rst(m, th, so, tp)); 6877 /* 6878 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 6879 * synchronized state. 6880 */ 6881 if (thflags & TH_SYN) { 6882 ctf_challenge_ack(m, th, tp, &ret_val); 6883 return (ret_val); 6884 } 6885 /* 6886 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 6887 * it's less than ts_recent, drop it. 6888 */ 6889 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 6890 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 6891 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 6892 return (ret_val); 6893 } 6894 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 6895 return (ret_val); 6896 } 6897 /* 6898 * If new data are received on a connection after the user processes 6899 * are gone, then RST the other end. 6900 */ 6901 if ((so->so_state & SS_NOFDREF) && tlen) { 6902 if (rack_check_data_after_close(m, tp, &tlen, th, so)) 6903 return (1); 6904 } 6905 /* 6906 * If last ACK falls within this segment's sequence numbers, record 6907 * its timestamp. NOTE: 1) That the test incorporates suggestions 6908 * from the latest proposal of the tcplw@cray.com list (Braden 6909 * 1993/04/26). 2) That updating only on newer timestamps interferes 6910 * with our earlier PAWS tests, so this check should be solely 6911 * predicated on the sequence space of this segment. 3) That we 6912 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 6913 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 6914 * SEG.Len, This modified check allows us to overcome RFC1323's 6915 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 6916 * p.869. In such cases, we can still calculate the RTT correctly 6917 * when RCV.NXT == Last.ACK.Sent. 6918 */ 6919 if ((to->to_flags & TOF_TS) != 0 && 6920 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 6921 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 6922 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 6923 tp->ts_recent_age = tcp_ts_getticks(); 6924 tp->ts_recent = to->to_tsval; 6925 } 6926 /* 6927 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 6928 * is on (half-synchronized state), then queue data for later 6929 * processing; else drop segment and return. 6930 */ 6931 if ((thflags & TH_ACK) == 0) { 6932 if (tp->t_flags & TF_NEEDSYN) { 6933 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6934 tiwin, thflags, nxt_pkt)); 6935 } else if (tp->t_flags & TF_ACKNOW) { 6936 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 6937 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 6938 return (ret_val); 6939 } else { 6940 ctf_do_drop(m, NULL); 6941 return (0); 6942 } 6943 } 6944 /* 6945 * Ack processing. 6946 */ 6947 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) { 6948 return (ret_val); 6949 } 6950 if (ourfinisacked) { 6951 /* 6952 * If we can't receive any more data, then closing user can 6953 * proceed. Starting the timer is contrary to the 6954 * specification, but if we don't get a FIN we'll hang 6955 * forever. 6956 * 6957 * XXXjl: we should release the tp also, and use a 6958 * compressed state. 6959 */ 6960 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 6961 soisdisconnected(so); 6962 tcp_timer_activate(tp, TT_2MSL, 6963 (tcp_fast_finwait2_recycle ? 6964 tcp_finwait2_timeout : 6965 TP_MAXIDLE(tp))); 6966 } 6967 tcp_state_change(tp, TCPS_FIN_WAIT_2); 6968 } 6969 if (sbavail(&so->so_snd)) { 6970 if (rack_progress_timeout_check(tp)) { 6971 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 6972 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6973 return (1); 6974 } 6975 } 6976 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6977 tiwin, thflags, nxt_pkt)); 6978 } 6979 6980 /* 6981 * Return value of 1, the TCB is unlocked and most 6982 * likely gone, return value of 0, the TCP is still 6983 * locked. 6984 */ 6985 static int 6986 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so, 6987 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6988 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 6989 { 6990 int32_t ret_val = 0; 6991 int32_t ourfinisacked = 0; 6992 6993 ctf_calc_rwin(so, tp); 6994 6995 if ((thflags & TH_RST) || 6996 (tp->t_fin_is_rst && (thflags & TH_FIN))) 6997 return (ctf_process_rst(m, th, so, tp)); 6998 /* 6999 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 7000 * synchronized state. 7001 */ 7002 if (thflags & TH_SYN) { 7003 ctf_challenge_ack(m, th, tp, &ret_val); 7004 return (ret_val); 7005 } 7006 /* 7007 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 7008 * it's less than ts_recent, drop it. 7009 */ 7010 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 7011 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 7012 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 7013 return (ret_val); 7014 } 7015 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 7016 return (ret_val); 7017 } 7018 /* 7019 * If new data are received on a connection after the user processes 7020 * are gone, then RST the other end. 7021 */ 7022 if ((so->so_state & SS_NOFDREF) && tlen) { 7023 if (rack_check_data_after_close(m, tp, &tlen, th, so)) 7024 return (1); 7025 } 7026 /* 7027 * If last ACK falls within this segment's sequence numbers, record 7028 * its timestamp. NOTE: 1) That the test incorporates suggestions 7029 * from the latest proposal of the tcplw@cray.com list (Braden 7030 * 1993/04/26). 2) That updating only on newer timestamps interferes 7031 * with our earlier PAWS tests, so this check should be solely 7032 * predicated on the sequence space of this segment. 3) That we 7033 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 7034 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 7035 * SEG.Len, This modified check allows us to overcome RFC1323's 7036 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 7037 * p.869. In such cases, we can still calculate the RTT correctly 7038 * when RCV.NXT == Last.ACK.Sent. 7039 */ 7040 if ((to->to_flags & TOF_TS) != 0 && 7041 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 7042 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 7043 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 7044 tp->ts_recent_age = tcp_ts_getticks(); 7045 tp->ts_recent = to->to_tsval; 7046 } 7047 /* 7048 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 7049 * is on (half-synchronized state), then queue data for later 7050 * processing; else drop segment and return. 7051 */ 7052 if ((thflags & TH_ACK) == 0) { 7053 if (tp->t_flags & TF_NEEDSYN) { 7054 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7055 tiwin, thflags, nxt_pkt)); 7056 } else if (tp->t_flags & TF_ACKNOW) { 7057 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 7058 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 7059 return (ret_val); 7060 } else { 7061 ctf_do_drop(m, NULL); 7062 return (0); 7063 } 7064 } 7065 /* 7066 * Ack processing. 7067 */ 7068 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) { 7069 return (ret_val); 7070 } 7071 if (ourfinisacked) { 7072 tcp_twstart(tp); 7073 m_freem(m); 7074 return (1); 7075 } 7076 if (sbavail(&so->so_snd)) { 7077 if (rack_progress_timeout_check(tp)) { 7078 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 7079 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 7080 return (1); 7081 } 7082 } 7083 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7084 tiwin, thflags, nxt_pkt)); 7085 } 7086 7087 /* 7088 * Return value of 1, the TCB is unlocked and most 7089 * likely gone, return value of 0, the TCP is still 7090 * locked. 7091 */ 7092 static int 7093 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so, 7094 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 7095 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 7096 { 7097 int32_t ret_val = 0; 7098 int32_t ourfinisacked = 0; 7099 7100 ctf_calc_rwin(so, tp); 7101 7102 if ((thflags & TH_RST) || 7103 (tp->t_fin_is_rst && (thflags & TH_FIN))) 7104 return (ctf_process_rst(m, th, so, tp)); 7105 /* 7106 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 7107 * synchronized state. 7108 */ 7109 if (thflags & TH_SYN) { 7110 ctf_challenge_ack(m, th, tp, &ret_val); 7111 return (ret_val); 7112 } 7113 /* 7114 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 7115 * it's less than ts_recent, drop it. 7116 */ 7117 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 7118 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 7119 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 7120 return (ret_val); 7121 } 7122 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 7123 return (ret_val); 7124 } 7125 /* 7126 * If new data are received on a connection after the user processes 7127 * are gone, then RST the other end. 7128 */ 7129 if ((so->so_state & SS_NOFDREF) && tlen) { 7130 if (rack_check_data_after_close(m, tp, &tlen, th, so)) 7131 return (1); 7132 } 7133 /* 7134 * If last ACK falls within this segment's sequence numbers, record 7135 * its timestamp. NOTE: 1) That the test incorporates suggestions 7136 * from the latest proposal of the tcplw@cray.com list (Braden 7137 * 1993/04/26). 2) That updating only on newer timestamps interferes 7138 * with our earlier PAWS tests, so this check should be solely 7139 * predicated on the sequence space of this segment. 3) That we 7140 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 7141 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 7142 * SEG.Len, This modified check allows us to overcome RFC1323's 7143 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 7144 * p.869. In such cases, we can still calculate the RTT correctly 7145 * when RCV.NXT == Last.ACK.Sent. 7146 */ 7147 if ((to->to_flags & TOF_TS) != 0 && 7148 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 7149 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 7150 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 7151 tp->ts_recent_age = tcp_ts_getticks(); 7152 tp->ts_recent = to->to_tsval; 7153 } 7154 /* 7155 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 7156 * is on (half-synchronized state), then queue data for later 7157 * processing; else drop segment and return. 7158 */ 7159 if ((thflags & TH_ACK) == 0) { 7160 if (tp->t_flags & TF_NEEDSYN) { 7161 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7162 tiwin, thflags, nxt_pkt)); 7163 } else if (tp->t_flags & TF_ACKNOW) { 7164 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 7165 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 7166 return (ret_val); 7167 } else { 7168 ctf_do_drop(m, NULL); 7169 return (0); 7170 } 7171 } 7172 /* 7173 * case TCPS_LAST_ACK: Ack processing. 7174 */ 7175 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) { 7176 return (ret_val); 7177 } 7178 if (ourfinisacked) { 7179 tp = tcp_close(tp); 7180 ctf_do_drop(m, tp); 7181 return (1); 7182 } 7183 if (sbavail(&so->so_snd)) { 7184 if (rack_progress_timeout_check(tp)) { 7185 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 7186 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 7187 return (1); 7188 } 7189 } 7190 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7191 tiwin, thflags, nxt_pkt)); 7192 } 7193 7194 7195 /* 7196 * Return value of 1, the TCB is unlocked and most 7197 * likely gone, return value of 0, the TCP is still 7198 * locked. 7199 */ 7200 static int 7201 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so, 7202 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 7203 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 7204 { 7205 int32_t ret_val = 0; 7206 int32_t ourfinisacked = 0; 7207 7208 ctf_calc_rwin(so, tp); 7209 7210 /* Reset receive buffer auto scaling when not in bulk receive mode. */ 7211 if ((thflags & TH_RST) || 7212 (tp->t_fin_is_rst && (thflags & TH_FIN))) 7213 return (ctf_process_rst(m, th, so, tp)); 7214 /* 7215 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 7216 * synchronized state. 7217 */ 7218 if (thflags & TH_SYN) { 7219 ctf_challenge_ack(m, th, tp, &ret_val); 7220 return (ret_val); 7221 } 7222 /* 7223 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 7224 * it's less than ts_recent, drop it. 7225 */ 7226 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 7227 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 7228 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 7229 return (ret_val); 7230 } 7231 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 7232 return (ret_val); 7233 } 7234 /* 7235 * If new data are received on a connection after the user processes 7236 * are gone, then RST the other end. 7237 */ 7238 if ((so->so_state & SS_NOFDREF) && 7239 tlen) { 7240 if (rack_check_data_after_close(m, tp, &tlen, th, so)) 7241 return (1); 7242 } 7243 /* 7244 * If last ACK falls within this segment's sequence numbers, record 7245 * its timestamp. NOTE: 1) That the test incorporates suggestions 7246 * from the latest proposal of the tcplw@cray.com list (Braden 7247 * 1993/04/26). 2) That updating only on newer timestamps interferes 7248 * with our earlier PAWS tests, so this check should be solely 7249 * predicated on the sequence space of this segment. 3) That we 7250 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 7251 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 7252 * SEG.Len, This modified check allows us to overcome RFC1323's 7253 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 7254 * p.869. In such cases, we can still calculate the RTT correctly 7255 * when RCV.NXT == Last.ACK.Sent. 7256 */ 7257 if ((to->to_flags & TOF_TS) != 0 && 7258 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 7259 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 7260 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 7261 tp->ts_recent_age = tcp_ts_getticks(); 7262 tp->ts_recent = to->to_tsval; 7263 } 7264 /* 7265 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 7266 * is on (half-synchronized state), then queue data for later 7267 * processing; else drop segment and return. 7268 */ 7269 if ((thflags & TH_ACK) == 0) { 7270 if (tp->t_flags & TF_NEEDSYN) { 7271 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7272 tiwin, thflags, nxt_pkt)); 7273 } else if (tp->t_flags & TF_ACKNOW) { 7274 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 7275 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 7276 return (ret_val); 7277 } else { 7278 ctf_do_drop(m, NULL); 7279 return (0); 7280 } 7281 } 7282 /* 7283 * Ack processing. 7284 */ 7285 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) { 7286 return (ret_val); 7287 } 7288 if (sbavail(&so->so_snd)) { 7289 if (rack_progress_timeout_check(tp)) { 7290 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 7291 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 7292 return (1); 7293 } 7294 } 7295 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7296 tiwin, thflags, nxt_pkt)); 7297 } 7298 7299 7300 static void inline 7301 rack_clear_rate_sample(struct tcp_rack *rack) 7302 { 7303 rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY; 7304 rack->r_ctl.rack_rs.rs_rtt_cnt = 0; 7305 rack->r_ctl.rack_rs.rs_rtt_tot = 0; 7306 } 7307 7308 static void 7309 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack) 7310 { 7311 uint32_t tls_seg = 0; 7312 7313 #ifdef KERN_TLS 7314 if (rack->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) { 7315 tls_seg = ctf_get_opt_tls_size(rack->rc_inp->inp_socket, rack->rc_tp->snd_wnd); 7316 rack->r_ctl.rc_pace_min_segs = tls_seg; 7317 } else 7318 #endif 7319 rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp); 7320 rack->r_ctl.rc_pace_max_segs = ctf_fixed_maxseg(tp) * rack->rc_pace_max_segs; 7321 if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) 7322 rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES; 7323 #ifdef KERN_TLS 7324 if (tls_seg != 0) { 7325 if (rack_hw_tls_max_seg > 1) { 7326 rack->r_ctl.rc_pace_max_segs /= tls_seg; 7327 if (rack_hw_tls_max_seg < rack->r_ctl.rc_pace_max_segs) 7328 rack->r_ctl.rc_pace_max_segs = rack_hw_tls_max_seg; 7329 } else { 7330 rack->r_ctl.rc_pace_max_segs = 1; 7331 } 7332 if (rack->r_ctl.rc_pace_max_segs == 0) 7333 rack->r_ctl.rc_pace_max_segs = 1; 7334 rack->r_ctl.rc_pace_max_segs *= tls_seg; 7335 } 7336 #endif 7337 rack_log_type_hrdwtso(tp, rack, tls_seg, rack->rc_inp->inp_socket->so_snd.sb_flags, 0, 2); 7338 } 7339 7340 static int 7341 rack_init(struct tcpcb *tp) 7342 { 7343 struct tcp_rack *rack = NULL; 7344 struct rack_sendmap *insret; 7345 7346 tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT); 7347 if (tp->t_fb_ptr == NULL) { 7348 /* 7349 * We need to allocate memory but cant. The INP and INP_INFO 7350 * locks and they are recusive (happens during setup. So a 7351 * scheme to drop the locks fails :( 7352 * 7353 */ 7354 return (ENOMEM); 7355 } 7356 memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack)); 7357 7358 rack = (struct tcp_rack *)tp->t_fb_ptr; 7359 RB_INIT(&rack->r_ctl.rc_mtree); 7360 TAILQ_INIT(&rack->r_ctl.rc_free); 7361 TAILQ_INIT(&rack->r_ctl.rc_tmap); 7362 rack->rc_tp = tp; 7363 if (tp->t_inpcb) { 7364 rack->rc_inp = tp->t_inpcb; 7365 } 7366 tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ; 7367 /* Probably not needed but lets be sure */ 7368 rack_clear_rate_sample(rack); 7369 rack->r_cpu = 0; 7370 rack->r_ctl.rc_reorder_fade = rack_reorder_fade; 7371 rack->rc_allow_data_af_clo = rack_ignore_data_after_close; 7372 rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh; 7373 rack->rc_pace_reduce = rack_slot_reduction; 7374 if (use_rack_cheat) 7375 rack->use_rack_cheat = 1; 7376 if (V_tcp_delack_enabled) 7377 tp->t_delayed_ack = 1; 7378 else 7379 tp->t_delayed_ack = 0; 7380 rack->rc_pace_max_segs = rack_hptsi_segments; 7381 rack->r_ctl.rc_reorder_shift = rack_reorder_thresh; 7382 rack->r_ctl.rc_pkt_delay = rack_pkt_delay; 7383 rack->r_ctl.rc_prop_reduce = rack_use_proportional_reduce; 7384 rack->r_enforce_min_pace = rack_min_pace_time; 7385 rack->r_ctl.rc_prop_rate = rack_proportional_rate; 7386 rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp; 7387 rack->r_ctl.rc_early_recovery = rack_early_recovery; 7388 rack->rc_always_pace = rack_pace_every_seg; 7389 rack_set_pace_segments(tp, rack); 7390 rack->r_ctl.rc_high_rwnd = tp->snd_wnd; 7391 rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method; 7392 rack->rack_tlp_threshold_use = rack_tlp_threshold_use; 7393 rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr; 7394 rack->r_ctl.rc_min_to = rack_min_to; 7395 rack->rack_per_of_gp = rack_per_of_gp; 7396 microuptime(&rack->r_ctl.rc_last_ack); 7397 rack->r_ctl.rc_last_time_decay = rack->r_ctl.rc_last_ack; 7398 rack->r_ctl.rc_tlp_rxt_last_time = tcp_ts_getticks(); 7399 /* Do we force on detection? */ 7400 #ifdef NETFLIX_EXP_DETECTION 7401 if (tcp_force_detection) 7402 rack->do_detection = 1; 7403 else 7404 #endif 7405 rack->do_detection = 0; 7406 if (tp->snd_una != tp->snd_max) { 7407 /* Create a send map for the current outstanding data */ 7408 struct rack_sendmap *rsm; 7409 7410 rsm = rack_alloc(rack); 7411 if (rsm == NULL) { 7412 uma_zfree(rack_pcb_zone, tp->t_fb_ptr); 7413 tp->t_fb_ptr = NULL; 7414 return (ENOMEM); 7415 } 7416 rsm->r_flags = RACK_OVERMAX; 7417 rsm->r_tim_lastsent[0] = rack->r_ctl.rc_tlp_rxt_last_time; 7418 rsm->r_rtr_cnt = 1; 7419 rsm->r_rtr_bytes = 0; 7420 rsm->r_start = tp->snd_una; 7421 rsm->r_end = tp->snd_max; 7422 rsm->r_dupack = 0; 7423 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 7424 #ifdef INVARIANTS 7425 if (insret != NULL) { 7426 panic("Insert in rb tree fails ret:%p rack:%p rsm:%p", 7427 insret, rack, rsm); 7428 } 7429 #endif 7430 TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext); 7431 rsm->r_in_tmap = 1; 7432 } 7433 rack_stop_all_timers(tp); 7434 rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0); 7435 return (0); 7436 } 7437 7438 static int 7439 rack_handoff_ok(struct tcpcb *tp) 7440 { 7441 if ((tp->t_state == TCPS_CLOSED) || 7442 (tp->t_state == TCPS_LISTEN)) { 7443 /* Sure no problem though it may not stick */ 7444 return (0); 7445 } 7446 if ((tp->t_state == TCPS_SYN_SENT) || 7447 (tp->t_state == TCPS_SYN_RECEIVED)) { 7448 /* 7449 * We really don't know you have to get to ESTAB or beyond 7450 * to tell. 7451 */ 7452 return (EAGAIN); 7453 } 7454 if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){ 7455 return (0); 7456 } 7457 /* 7458 * If we reach here we don't do SACK on this connection so we can 7459 * never do rack. 7460 */ 7461 return (EINVAL); 7462 } 7463 7464 static void 7465 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged) 7466 { 7467 if (tp->t_fb_ptr) { 7468 struct tcp_rack *rack; 7469 struct rack_sendmap *rsm, *nrsm, *rm; 7470 if (tp->t_inpcb) { 7471 tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ; 7472 tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY; 7473 } 7474 rack = (struct tcp_rack *)tp->t_fb_ptr; 7475 #ifdef TCP_BLACKBOX 7476 tcp_log_flowend(tp); 7477 #endif 7478 RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) { 7479 rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 7480 #ifdef INVARIANTS 7481 if (rm != rsm) { 7482 panic("At fini, rack:%p rsm:%p rm:%p", 7483 rack, rsm, rm); 7484 } 7485 #endif 7486 uma_zfree(rack_zone, rsm); 7487 } 7488 rsm = TAILQ_FIRST(&rack->r_ctl.rc_free); 7489 while (rsm) { 7490 TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext); 7491 uma_zfree(rack_zone, rsm); 7492 rsm = TAILQ_FIRST(&rack->r_ctl.rc_free); 7493 } 7494 rack->rc_free_cnt = 0; 7495 uma_zfree(rack_pcb_zone, tp->t_fb_ptr); 7496 tp->t_fb_ptr = NULL; 7497 } 7498 /* Make sure snd_nxt is correctly set */ 7499 tp->snd_nxt = tp->snd_max; 7500 } 7501 7502 7503 static void 7504 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack) 7505 { 7506 switch (tp->t_state) { 7507 case TCPS_SYN_SENT: 7508 rack->r_state = TCPS_SYN_SENT; 7509 rack->r_substate = rack_do_syn_sent; 7510 break; 7511 case TCPS_SYN_RECEIVED: 7512 rack->r_state = TCPS_SYN_RECEIVED; 7513 rack->r_substate = rack_do_syn_recv; 7514 break; 7515 case TCPS_ESTABLISHED: 7516 rack_set_pace_segments(tp, rack); 7517 rack->r_state = TCPS_ESTABLISHED; 7518 rack->r_substate = rack_do_established; 7519 break; 7520 case TCPS_CLOSE_WAIT: 7521 rack->r_state = TCPS_CLOSE_WAIT; 7522 rack->r_substate = rack_do_close_wait; 7523 break; 7524 case TCPS_FIN_WAIT_1: 7525 rack->r_state = TCPS_FIN_WAIT_1; 7526 rack->r_substate = rack_do_fin_wait_1; 7527 break; 7528 case TCPS_CLOSING: 7529 rack->r_state = TCPS_CLOSING; 7530 rack->r_substate = rack_do_closing; 7531 break; 7532 case TCPS_LAST_ACK: 7533 rack->r_state = TCPS_LAST_ACK; 7534 rack->r_substate = rack_do_lastack; 7535 break; 7536 case TCPS_FIN_WAIT_2: 7537 rack->r_state = TCPS_FIN_WAIT_2; 7538 rack->r_substate = rack_do_fin_wait_2; 7539 break; 7540 case TCPS_LISTEN: 7541 case TCPS_CLOSED: 7542 case TCPS_TIME_WAIT: 7543 default: 7544 break; 7545 }; 7546 } 7547 7548 7549 static void 7550 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb) 7551 { 7552 /* 7553 * We received an ack, and then did not 7554 * call send or were bounced out due to the 7555 * hpts was running. Now a timer is up as well, is 7556 * it the right timer? 7557 */ 7558 struct rack_sendmap *rsm; 7559 int tmr_up; 7560 7561 tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK; 7562 if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT)) 7563 return; 7564 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 7565 if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) && 7566 (tmr_up == PACE_TMR_RXT)) { 7567 /* Should be an RXT */ 7568 return; 7569 } 7570 if (rsm == NULL) { 7571 /* Nothing outstanding? */ 7572 if (tp->t_flags & TF_DELACK) { 7573 if (tmr_up == PACE_TMR_DELACK) 7574 /* We are supposed to have delayed ack up and we do */ 7575 return; 7576 } else if (sbavail(&tp->t_inpcb->inp_socket->so_snd) && (tmr_up == PACE_TMR_RXT)) { 7577 /* 7578 * if we hit enobufs then we would expect the possiblity 7579 * of nothing outstanding and the RXT up (and the hptsi timer). 7580 */ 7581 return; 7582 } else if (((V_tcp_always_keepalive || 7583 rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) && 7584 (tp->t_state <= TCPS_CLOSING)) && 7585 (tmr_up == PACE_TMR_KEEP) && 7586 (tp->snd_max == tp->snd_una)) { 7587 /* We should have keep alive up and we do */ 7588 return; 7589 } 7590 } 7591 if (SEQ_GT(tp->snd_max, tp->snd_una) && 7592 ((tmr_up == PACE_TMR_TLP) || 7593 (tmr_up == PACE_TMR_RACK) || 7594 (tmr_up == PACE_TMR_RXT))) { 7595 /* 7596 * Either a Rack, TLP or RXT is fine if we 7597 * have outstanding data. 7598 */ 7599 return; 7600 } else if (tmr_up == PACE_TMR_DELACK) { 7601 /* 7602 * If the delayed ack was going to go off 7603 * before the rtx/tlp/rack timer were going to 7604 * expire, then that would be the timer in control. 7605 * Note we don't check the time here trusting the 7606 * code is correct. 7607 */ 7608 return; 7609 } 7610 /* 7611 * Ok the timer originally started is not what we want now. 7612 * We will force the hpts to be stopped if any, and restart 7613 * with the slot set to what was in the saved slot. 7614 */ 7615 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 7616 rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0); 7617 } 7618 7619 static int 7620 rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so, 7621 struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos, 7622 int32_t nxt_pkt, struct timeval *tv) 7623 { 7624 int32_t thflags, retval, did_out = 0; 7625 int32_t way_out = 0; 7626 uint32_t cts; 7627 uint32_t tiwin; 7628 struct tcpopt to; 7629 struct tcp_rack *rack; 7630 struct rack_sendmap *rsm; 7631 int32_t prev_state = 0; 7632 7633 if (m->m_flags & M_TSTMP_LRO) { 7634 tv->tv_sec = m->m_pkthdr.rcv_tstmp /1000000000; 7635 tv->tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000; 7636 } 7637 cts = tcp_tv_to_mssectick(tv); 7638 rack = (struct tcp_rack *)tp->t_fb_ptr; 7639 7640 kern_prefetch(rack, &prev_state); 7641 prev_state = 0; 7642 thflags = th->th_flags; 7643 7644 NET_EPOCH_ASSERT(); 7645 INP_WLOCK_ASSERT(tp->t_inpcb); 7646 KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN", 7647 __func__)); 7648 KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT", 7649 __func__)); 7650 if (tp->t_logstate != TCP_LOG_STATE_OFF) { 7651 union tcp_log_stackspecific log; 7652 struct timeval tv; 7653 7654 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 7655 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 7656 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 7657 log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt; 7658 log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced; 7659 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 7660 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 7661 log.u_bbr.pkts_out = rack->rc_tp->t_maxseg; 7662 TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0, 7663 tlen, &log, true, &tv); 7664 } 7665 if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) { 7666 way_out = 4; 7667 retval = 0; 7668 goto done_with_input; 7669 } 7670 /* 7671 * If a segment with the ACK-bit set arrives in the SYN-SENT state 7672 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9. 7673 */ 7674 if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) && 7675 (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) { 7676 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 7677 return(1); 7678 } 7679 /* 7680 * Segment received on connection. Reset idle time and keep-alive 7681 * timer. XXX: This should be done after segment validation to 7682 * ignore broken/spoofed segs. 7683 */ 7684 if (tp->t_idle_reduce && 7685 (tp->snd_max == tp->snd_una) && 7686 ((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) { 7687 counter_u64_add(rack_input_idle_reduces, 1); 7688 rack_cc_after_idle(tp); 7689 } 7690 tp->t_rcvtime = ticks; 7691 7692 /* 7693 * Unscale the window into a 32-bit value. For the SYN_SENT state 7694 * the scale is zero. 7695 */ 7696 tiwin = th->th_win << tp->snd_scale; 7697 #ifdef STATS 7698 stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin); 7699 #endif 7700 if (tiwin > rack->r_ctl.rc_high_rwnd) 7701 rack->r_ctl.rc_high_rwnd = tiwin; 7702 /* 7703 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move 7704 * this to occur after we've validated the segment. 7705 */ 7706 if (tp->t_flags2 & TF2_ECN_PERMIT) { 7707 if (thflags & TH_CWR) { 7708 tp->t_flags2 &= ~TF2_ECN_SND_ECE; 7709 tp->t_flags |= TF_ACKNOW; 7710 } 7711 switch (iptos & IPTOS_ECN_MASK) { 7712 case IPTOS_ECN_CE: 7713 tp->t_flags2 |= TF2_ECN_SND_ECE; 7714 TCPSTAT_INC(tcps_ecn_ce); 7715 break; 7716 case IPTOS_ECN_ECT0: 7717 TCPSTAT_INC(tcps_ecn_ect0); 7718 break; 7719 case IPTOS_ECN_ECT1: 7720 TCPSTAT_INC(tcps_ecn_ect1); 7721 break; 7722 } 7723 7724 /* Process a packet differently from RFC3168. */ 7725 cc_ecnpkt_handler(tp, th, iptos); 7726 7727 /* Congestion experienced. */ 7728 if (thflags & TH_ECE) { 7729 rack_cong_signal(tp, th, CC_ECN); 7730 } 7731 } 7732 /* 7733 * Parse options on any incoming segment. 7734 */ 7735 tcp_dooptions(&to, (u_char *)(th + 1), 7736 (th->th_off << 2) - sizeof(struct tcphdr), 7737 (thflags & TH_SYN) ? TO_SYN : 0); 7738 7739 /* 7740 * If echoed timestamp is later than the current time, fall back to 7741 * non RFC1323 RTT calculation. Normalize timestamp if syncookies 7742 * were used when this connection was established. 7743 */ 7744 if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) { 7745 to.to_tsecr -= tp->ts_offset; 7746 if (TSTMP_GT(to.to_tsecr, cts)) 7747 to.to_tsecr = 0; 7748 } 7749 /* 7750 * If its the first time in we need to take care of options and 7751 * verify we can do SACK for rack! 7752 */ 7753 if (rack->r_state == 0) { 7754 /* Should be init'd by rack_init() */ 7755 KASSERT(rack->rc_inp != NULL, 7756 ("%s: rack->rc_inp unexpectedly NULL", __func__)); 7757 if (rack->rc_inp == NULL) { 7758 rack->rc_inp = tp->t_inpcb; 7759 } 7760 7761 /* 7762 * Process options only when we get SYN/ACK back. The SYN 7763 * case for incoming connections is handled in tcp_syncache. 7764 * According to RFC1323 the window field in a SYN (i.e., a 7765 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX 7766 * this is traditional behavior, may need to be cleaned up. 7767 */ 7768 rack->r_cpu = inp_to_cpuid(tp->t_inpcb); 7769 if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) { 7770 if ((to.to_flags & TOF_SCALE) && 7771 (tp->t_flags & TF_REQ_SCALE)) { 7772 tp->t_flags |= TF_RCVD_SCALE; 7773 tp->snd_scale = to.to_wscale; 7774 } 7775 /* 7776 * Initial send window. It will be updated with the 7777 * next incoming segment to the scaled value. 7778 */ 7779 tp->snd_wnd = th->th_win; 7780 if (to.to_flags & TOF_TS) { 7781 tp->t_flags |= TF_RCVD_TSTMP; 7782 tp->ts_recent = to.to_tsval; 7783 tp->ts_recent_age = cts; 7784 } 7785 if (to.to_flags & TOF_MSS) 7786 tcp_mss(tp, to.to_mss); 7787 if ((tp->t_flags & TF_SACK_PERMIT) && 7788 (to.to_flags & TOF_SACKPERM) == 0) 7789 tp->t_flags &= ~TF_SACK_PERMIT; 7790 if (IS_FASTOPEN(tp->t_flags)) { 7791 if (to.to_flags & TOF_FASTOPEN) { 7792 uint16_t mss; 7793 7794 if (to.to_flags & TOF_MSS) 7795 mss = to.to_mss; 7796 else 7797 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) 7798 mss = TCP6_MSS; 7799 else 7800 mss = TCP_MSS; 7801 tcp_fastopen_update_cache(tp, mss, 7802 to.to_tfo_len, to.to_tfo_cookie); 7803 } else 7804 tcp_fastopen_disable_path(tp); 7805 } 7806 } 7807 /* 7808 * At this point we are at the initial call. Here we decide 7809 * if we are doing RACK or not. We do this by seeing if 7810 * TF_SACK_PERMIT is set, if not rack is *not* possible and 7811 * we switch to the default code. 7812 */ 7813 if ((tp->t_flags & TF_SACK_PERMIT) == 0) { 7814 tcp_switch_back_to_default(tp); 7815 (*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen, 7816 tlen, iptos); 7817 return (1); 7818 } 7819 /* Set the flag */ 7820 rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0; 7821 tcp_set_hpts(tp->t_inpcb); 7822 sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack); 7823 } 7824 /* 7825 * This is the one exception case where we set the rack state 7826 * always. All other times (timers etc) we must have a rack-state 7827 * set (so we assure we have done the checks above for SACK). 7828 */ 7829 memcpy(&rack->r_ctl.rc_last_ack, tv, sizeof(struct timeval)); 7830 rack->r_ctl.rc_rcvtime = cts; 7831 if (rack->r_state != tp->t_state) 7832 rack_set_state(tp, rack); 7833 if (SEQ_GT(th->th_ack, tp->snd_una) && 7834 (rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL) 7835 kern_prefetch(rsm, &prev_state); 7836 prev_state = rack->r_state; 7837 rack->r_ctl.rc_tlp_send_cnt = 0; 7838 rack_clear_rate_sample(rack); 7839 retval = (*rack->r_substate) (m, th, so, 7840 tp, &to, drop_hdrlen, 7841 tlen, tiwin, thflags, nxt_pkt, iptos); 7842 #ifdef INVARIANTS 7843 if ((retval == 0) && 7844 (tp->t_inpcb == NULL)) { 7845 panic("retval:%d tp:%p t_inpcb:NULL state:%d", 7846 retval, tp, prev_state); 7847 } 7848 #endif 7849 if (retval == 0) { 7850 /* 7851 * If retval is 1 the tcb is unlocked and most likely the tp 7852 * is gone. 7853 */ 7854 INP_WLOCK_ASSERT(tp->t_inpcb); 7855 if (rack->set_pacing_done_a_iw == 0) { 7856 /* How much has been acked? */ 7857 if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) { 7858 /* We have enough to set in the pacing segment size */ 7859 rack->set_pacing_done_a_iw = 1; 7860 rack_set_pace_segments(tp, rack); 7861 } 7862 } 7863 tcp_rack_xmit_timer_commit(rack, tp); 7864 if ((nxt_pkt == 0) || (IN_RECOVERY(tp->t_flags))) { 7865 if (rack->r_wanted_output != 0) { 7866 did_out = 1; 7867 (void)tp->t_fb->tfb_tcp_output(tp); 7868 } 7869 rack_start_hpts_timer(rack, tp, cts, 0, 0, 0); 7870 } 7871 if ((nxt_pkt == 0) && 7872 ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) && 7873 (SEQ_GT(tp->snd_max, tp->snd_una) || 7874 (tp->t_flags & TF_DELACK) || 7875 ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) && 7876 (tp->t_state <= TCPS_CLOSING)))) { 7877 /* We could not send (probably in the hpts but stopped the timer earlier)? */ 7878 if ((tp->snd_max == tp->snd_una) && 7879 ((tp->t_flags & TF_DELACK) == 0) && 7880 (rack->rc_inp->inp_in_hpts) && 7881 (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) { 7882 /* keep alive not needed if we are hptsi output yet */ 7883 ; 7884 } else { 7885 if (rack->rc_inp->inp_in_hpts) { 7886 tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT); 7887 counter_u64_add(rack_per_timer_hole, 1); 7888 } 7889 rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0); 7890 } 7891 way_out = 1; 7892 } else if (nxt_pkt == 0) { 7893 /* Do we have the correct timer running? */ 7894 rack_timer_audit(tp, rack, &so->so_snd); 7895 way_out = 2; 7896 } 7897 done_with_input: 7898 rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out); 7899 if (did_out) 7900 rack->r_wanted_output = 0; 7901 #ifdef INVARIANTS 7902 if (tp->t_inpcb == NULL) { 7903 panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d", 7904 did_out, 7905 retval, tp, prev_state); 7906 } 7907 #endif 7908 } 7909 return (retval); 7910 } 7911 7912 void 7913 rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so, 7914 struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos) 7915 { 7916 struct timeval tv; 7917 7918 /* First lets see if we have old packets */ 7919 if (tp->t_in_pkt) { 7920 if (ctf_do_queued_segments(so, tp, 1)) { 7921 m_freem(m); 7922 return; 7923 } 7924 } 7925 if (m->m_flags & M_TSTMP_LRO) { 7926 tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000; 7927 tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000; 7928 } else { 7929 /* Should not be should we kassert instead? */ 7930 tcp_get_usecs(&tv); 7931 } 7932 if(rack_do_segment_nounlock(m, th, so, tp, 7933 drop_hdrlen, tlen, iptos, 0, &tv) == 0) 7934 INP_WUNLOCK(tp->t_inpcb); 7935 } 7936 7937 struct rack_sendmap * 7938 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused) 7939 { 7940 struct rack_sendmap *rsm = NULL; 7941 int32_t idx; 7942 uint32_t srtt = 0, thresh = 0, ts_low = 0; 7943 7944 /* Return the next guy to be re-transmitted */ 7945 if (RB_EMPTY(&rack->r_ctl.rc_mtree)) { 7946 return (NULL); 7947 } 7948 if (tp->t_flags & TF_SENTFIN) { 7949 /* retran the end FIN? */ 7950 return (NULL); 7951 } 7952 /* ok lets look at this one */ 7953 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 7954 if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) { 7955 goto check_it; 7956 } 7957 rsm = rack_find_lowest_rsm(rack); 7958 if (rsm == NULL) { 7959 return (NULL); 7960 } 7961 check_it: 7962 if (rsm->r_flags & RACK_ACKED) { 7963 return (NULL); 7964 } 7965 if ((rsm->r_flags & RACK_SACK_PASSED) == 0) { 7966 /* Its not yet ready */ 7967 return (NULL); 7968 } 7969 srtt = rack_grab_rtt(tp, rack); 7970 idx = rsm->r_rtr_cnt - 1; 7971 ts_low = rsm->r_tim_lastsent[idx]; 7972 thresh = rack_calc_thresh_rack(rack, srtt, tsused); 7973 if ((tsused == ts_low) || 7974 (TSTMP_LT(tsused, ts_low))) { 7975 /* No time since sending */ 7976 return (NULL); 7977 } 7978 if ((tsused - ts_low) < thresh) { 7979 /* It has not been long enough yet */ 7980 return (NULL); 7981 } 7982 if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) || 7983 ((rsm->r_flags & RACK_SACK_PASSED) && 7984 (rack->sack_attack_disable == 0))) { 7985 /* 7986 * We have passed the dup-ack threshold <or> 7987 * a SACK has indicated this is missing. 7988 * Note that if you are a declared attacker 7989 * it is only the dup-ack threshold that 7990 * will cause retransmits. 7991 */ 7992 /* log retransmit reason */ 7993 rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1); 7994 return (rsm); 7995 } 7996 return (NULL); 7997 } 7998 7999 static int32_t 8000 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len) 8001 { 8002 int32_t slot = 0; 8003 8004 if ((rack->rack_per_of_gp == 0) || 8005 (rack->rc_always_pace == 0)) { 8006 /* 8007 * We use the most optimistic possible cwnd/srtt for 8008 * sending calculations. This will make our 8009 * calculation anticipate getting more through 8010 * quicker then possible. But thats ok we don't want 8011 * the peer to have a gap in data sending. 8012 */ 8013 uint32_t srtt, cwnd, tr_perms = 0; 8014 8015 old_method: 8016 if (rack->r_ctl.rc_rack_min_rtt) 8017 srtt = rack->r_ctl.rc_rack_min_rtt; 8018 else 8019 srtt = TICKS_2_MSEC((tp->t_srtt >> TCP_RTT_SHIFT)); 8020 if (rack->r_ctl.rc_rack_largest_cwnd) 8021 cwnd = rack->r_ctl.rc_rack_largest_cwnd; 8022 else 8023 cwnd = tp->snd_cwnd; 8024 tr_perms = cwnd / srtt; 8025 if (tr_perms == 0) { 8026 tr_perms = ctf_fixed_maxseg(tp); 8027 } 8028 /* 8029 * Calculate how long this will take to drain, if 8030 * the calculation comes out to zero, thats ok we 8031 * will use send_a_lot to possibly spin around for 8032 * more increasing tot_len_this_send to the point 8033 * that its going to require a pace, or we hit the 8034 * cwnd. Which in that case we are just waiting for 8035 * a ACK. 8036 */ 8037 slot = len / tr_perms; 8038 /* Now do we reduce the time so we don't run dry? */ 8039 if (slot && rack->rc_pace_reduce) { 8040 int32_t reduce; 8041 8042 reduce = (slot / rack->rc_pace_reduce); 8043 if (reduce < slot) { 8044 slot -= reduce; 8045 } else 8046 slot = 0; 8047 } 8048 } else { 8049 int cnt; 8050 uint64_t bw_est, bw_raise, res, lentim; 8051 8052 bw_est = 0; 8053 for (cnt=0; cnt<RACK_GP_HIST; cnt++) { 8054 if ((rack->r_ctl.rc_gp_hist_filled == 0) && 8055 (rack->r_ctl.rc_gp_history[cnt] == 0)) 8056 break; 8057 bw_est += rack->r_ctl.rc_gp_history[cnt]; 8058 } 8059 if (bw_est == 0) { 8060 /* 8061 * No way yet to make a b/w estimate 8062 * (no goodput est yet). 8063 */ 8064 goto old_method; 8065 } 8066 /* Covert to bytes per second */ 8067 bw_est *= MSEC_IN_SECOND; 8068 /* 8069 * Now ratchet it up by our percentage. Note 8070 * that the minimum you can do is 1 which would 8071 * get you 101% of the average last N goodput estimates. 8072 * The max you can do is 256 which would yeild you 8073 * 356% of the last N goodput estimates. 8074 */ 8075 bw_raise = bw_est * (uint64_t)rack->rack_per_of_gp; 8076 bw_est += bw_raise; 8077 /* average by the number we added */ 8078 bw_est /= cnt; 8079 /* Now calculate a rate based on this b/w */ 8080 lentim = (uint64_t) len * (uint64_t)MSEC_IN_SECOND; 8081 res = lentim / bw_est; 8082 slot = (uint32_t)res; 8083 } 8084 if (rack->r_enforce_min_pace && 8085 (slot == 0)) { 8086 /* We are enforcing a minimum pace time of 1ms */ 8087 slot = rack->r_enforce_min_pace; 8088 } 8089 if (slot) 8090 counter_u64_add(rack_calc_nonzero, 1); 8091 else 8092 counter_u64_add(rack_calc_zero, 1); 8093 return (slot); 8094 } 8095 8096 static int 8097 rack_output(struct tcpcb *tp) 8098 { 8099 struct socket *so; 8100 uint32_t recwin, sendwin; 8101 uint32_t sb_offset; 8102 int32_t len, flags, error = 0; 8103 struct mbuf *m; 8104 struct mbuf *mb; 8105 uint32_t if_hw_tsomaxsegcount = 0; 8106 uint32_t if_hw_tsomaxsegsize = 0; 8107 int32_t maxseg; 8108 long tot_len_this_send = 0; 8109 struct ip *ip = NULL; 8110 #ifdef TCPDEBUG 8111 struct ipovly *ipov = NULL; 8112 #endif 8113 struct udphdr *udp = NULL; 8114 struct tcp_rack *rack; 8115 struct tcphdr *th; 8116 uint8_t pass = 0; 8117 uint8_t wanted_cookie = 0; 8118 u_char opt[TCP_MAXOLEN]; 8119 unsigned ipoptlen, optlen, hdrlen, ulen=0; 8120 uint32_t rack_seq; 8121 8122 #if defined(IPSEC) || defined(IPSEC_SUPPORT) 8123 unsigned ipsec_optlen = 0; 8124 8125 #endif 8126 int32_t idle, sendalot; 8127 int32_t sub_from_prr = 0; 8128 volatile int32_t sack_rxmit; 8129 struct rack_sendmap *rsm = NULL; 8130 int32_t tso, mtu; 8131 struct tcpopt to; 8132 int32_t slot = 0; 8133 int32_t sup_rack = 0; 8134 uint32_t cts; 8135 uint8_t hpts_calling, new_data_tlp = 0, doing_tlp = 0; 8136 int32_t do_a_prefetch; 8137 int32_t prefetch_rsm = 0; 8138 int force_tso = 0; 8139 int32_t orig_len; 8140 int32_t prefetch_so_done = 0; 8141 struct tcp_log_buffer *lgb = NULL; 8142 struct inpcb *inp; 8143 struct sockbuf *sb; 8144 #ifdef INET6 8145 struct ip6_hdr *ip6 = NULL; 8146 int32_t isipv6; 8147 #endif 8148 uint8_t filled_all = 0; 8149 bool hw_tls = false; 8150 8151 /* setup and take the cache hits here */ 8152 rack = (struct tcp_rack *)tp->t_fb_ptr; 8153 inp = rack->rc_inp; 8154 so = inp->inp_socket; 8155 sb = &so->so_snd; 8156 kern_prefetch(sb, &do_a_prefetch); 8157 do_a_prefetch = 1; 8158 8159 #ifdef KERN_TLS 8160 hw_tls = (so->so_snd.sb_flags & SB_TLS_IFNET) != 0; 8161 #endif 8162 8163 NET_EPOCH_ASSERT(); 8164 INP_WLOCK_ASSERT(inp); 8165 8166 #ifdef TCP_OFFLOAD 8167 if (tp->t_flags & TF_TOE) 8168 return (tcp_offload_output(tp)); 8169 #endif 8170 maxseg = ctf_fixed_maxseg(tp); 8171 /* 8172 * For TFO connections in SYN_RECEIVED, only allow the initial 8173 * SYN|ACK and those sent by the retransmit timer. 8174 */ 8175 if (IS_FASTOPEN(tp->t_flags) && 8176 (tp->t_state == TCPS_SYN_RECEIVED) && 8177 SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN|ACK sent */ 8178 (rack->r_ctl.rc_resend == NULL)) /* not a retransmit */ 8179 return (0); 8180 #ifdef INET6 8181 if (rack->r_state) { 8182 /* Use the cache line loaded if possible */ 8183 isipv6 = rack->r_is_v6; 8184 } else { 8185 isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 8186 } 8187 #endif 8188 cts = tcp_ts_getticks(); 8189 if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) && 8190 inp->inp_in_hpts) { 8191 /* 8192 * We are on the hpts for some timer but not hptsi output. 8193 * Remove from the hpts unconditionally. 8194 */ 8195 rack_timer_cancel(tp, rack, cts, __LINE__); 8196 } 8197 /* Mark that we have called rack_output(). */ 8198 if ((rack->r_timer_override) || 8199 (tp->t_flags & TF_FORCEDATA) || 8200 (tp->t_state < TCPS_ESTABLISHED)) { 8201 if (tp->t_inpcb->inp_in_hpts) 8202 tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT); 8203 } else if (tp->t_inpcb->inp_in_hpts) { 8204 /* 8205 * On the hpts you can't pass even if ACKNOW is on, we will 8206 * when the hpts fires. 8207 */ 8208 counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1); 8209 return (0); 8210 } 8211 hpts_calling = inp->inp_hpts_calls; 8212 inp->inp_hpts_calls = 0; 8213 if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) { 8214 if (rack_process_timers(tp, rack, cts, hpts_calling)) { 8215 counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1); 8216 return (0); 8217 } 8218 } 8219 rack->r_wanted_output = 0; 8220 rack->r_timer_override = 0; 8221 /* 8222 * For TFO connections in SYN_SENT or SYN_RECEIVED, 8223 * only allow the initial SYN or SYN|ACK and those sent 8224 * by the retransmit timer. 8225 */ 8226 if (IS_FASTOPEN(tp->t_flags) && 8227 ((tp->t_state == TCPS_SYN_RECEIVED) || 8228 (tp->t_state == TCPS_SYN_SENT)) && 8229 SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */ 8230 (tp->t_rxtshift == 0)) /* not a retransmit */ 8231 return (0); 8232 /* 8233 * Determine length of data that should be transmitted, and flags 8234 * that will be used. If there is some data or critical controls 8235 * (SYN, RST) to send, then transmit; otherwise, investigate 8236 * further. 8237 */ 8238 idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una); 8239 if (tp->t_idle_reduce) { 8240 if (idle && ((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) 8241 rack_cc_after_idle(tp); 8242 } 8243 tp->t_flags &= ~TF_LASTIDLE; 8244 if (idle) { 8245 if (tp->t_flags & TF_MORETOCOME) { 8246 tp->t_flags |= TF_LASTIDLE; 8247 idle = 0; 8248 } 8249 } 8250 again: 8251 /* 8252 * If we've recently taken a timeout, snd_max will be greater than 8253 * snd_nxt. There may be SACK information that allows us to avoid 8254 * resending already delivered data. Adjust snd_nxt accordingly. 8255 */ 8256 sendalot = 0; 8257 cts = tcp_ts_getticks(); 8258 tso = 0; 8259 mtu = 0; 8260 sb_offset = tp->snd_max - tp->snd_una; 8261 sendwin = min(tp->snd_wnd, tp->snd_cwnd); 8262 8263 flags = tcp_outflags[tp->t_state]; 8264 while (rack->rc_free_cnt < rack_free_cache) { 8265 rsm = rack_alloc(rack); 8266 if (rsm == NULL) { 8267 if (inp->inp_hpts_calls) 8268 /* Retry in a ms */ 8269 slot = 1; 8270 goto just_return_nolock; 8271 } 8272 TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext); 8273 rack->rc_free_cnt++; 8274 rsm = NULL; 8275 } 8276 if (inp->inp_hpts_calls) 8277 inp->inp_hpts_calls = 0; 8278 sack_rxmit = 0; 8279 len = 0; 8280 rsm = NULL; 8281 if (flags & TH_RST) { 8282 SOCKBUF_LOCK(sb); 8283 goto send; 8284 } 8285 if (rack->r_ctl.rc_tlpsend) { 8286 /* Tail loss probe */ 8287 long cwin; 8288 long tlen; 8289 8290 doing_tlp = 1; 8291 /* 8292 * Check if we can do a TLP with a RACK'd packet 8293 * this can happen if we are not doing the rack 8294 * cheat and we skipped to a TLP and it 8295 * went off. 8296 */ 8297 rsm = tcp_rack_output(tp, rack, cts); 8298 if (rsm == NULL) 8299 rsm = rack->r_ctl.rc_tlpsend; 8300 rack->r_ctl.rc_tlpsend = NULL; 8301 sack_rxmit = 1; 8302 tlen = rsm->r_end - rsm->r_start; 8303 if (tlen > ctf_fixed_maxseg(tp)) 8304 tlen = ctf_fixed_maxseg(tp); 8305 KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start), 8306 ("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p", 8307 __func__, __LINE__, 8308 rsm->r_start, tp->snd_una, tp, rack, rsm)); 8309 sb_offset = rsm->r_start - tp->snd_una; 8310 cwin = min(tp->snd_wnd, tlen); 8311 len = cwin; 8312 } else if (rack->r_ctl.rc_resend) { 8313 /* Retransmit timer */ 8314 rsm = rack->r_ctl.rc_resend; 8315 rack->r_ctl.rc_resend = NULL; 8316 len = rsm->r_end - rsm->r_start; 8317 sack_rxmit = 1; 8318 sendalot = 0; 8319 KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start), 8320 ("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p", 8321 __func__, __LINE__, 8322 rsm->r_start, tp->snd_una, tp, rack, rsm)); 8323 sb_offset = rsm->r_start - tp->snd_una; 8324 if (len >= ctf_fixed_maxseg(tp)) { 8325 len = ctf_fixed_maxseg(tp); 8326 } 8327 } else if ((rack->rc_in_persist == 0) && 8328 ((rsm = tcp_rack_output(tp, rack, cts)) != NULL)) { 8329 int maxseg; 8330 8331 maxseg = ctf_fixed_maxseg(tp); 8332 if ((!IN_RECOVERY(tp->t_flags)) && 8333 ((tp->t_flags & (TF_WASFRECOVERY | TF_WASCRECOVERY)) == 0)) { 8334 /* Enter recovery if not induced by a time-out */ 8335 rack->r_ctl.rc_rsm_start = rsm->r_start; 8336 rack->r_ctl.rc_cwnd_at = tp->snd_cwnd; 8337 rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh; 8338 rack_cong_signal(tp, NULL, CC_NDUPACK); 8339 /* 8340 * When we enter recovery we need to assure we send 8341 * one packet. 8342 */ 8343 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 8344 rack_log_to_prr(rack, 13); 8345 } 8346 #ifdef INVARIANTS 8347 if (SEQ_LT(rsm->r_start, tp->snd_una)) { 8348 panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n", 8349 tp, rack, rsm, rsm->r_start, tp->snd_una); 8350 } 8351 #endif 8352 len = rsm->r_end - rsm->r_start; 8353 KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start), 8354 ("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p", 8355 __func__, __LINE__, 8356 rsm->r_start, tp->snd_una, tp, rack, rsm)); 8357 sb_offset = rsm->r_start - tp->snd_una; 8358 /* Can we send it within the PRR boundary? */ 8359 if ((rack->use_rack_cheat == 0) && (len > rack->r_ctl.rc_prr_sndcnt)) { 8360 /* It does not fit */ 8361 if ((ctf_flight_size(tp, rack->r_ctl.rc_sacked) > len) && 8362 (rack->r_ctl.rc_prr_sndcnt < maxseg)) { 8363 /* 8364 * prr is less than a segment, we 8365 * have more acks due in besides 8366 * what we need to resend. Lets not send 8367 * to avoid sending small pieces of 8368 * what we need to retransmit. 8369 */ 8370 len = 0; 8371 goto just_return_nolock; 8372 } 8373 len = rack->r_ctl.rc_prr_sndcnt; 8374 } 8375 sendalot = 0; 8376 if (len >= maxseg) { 8377 len = maxseg; 8378 } 8379 if (len > 0) { 8380 sub_from_prr = 1; 8381 sack_rxmit = 1; 8382 TCPSTAT_INC(tcps_sack_rexmits); 8383 TCPSTAT_ADD(tcps_sack_rexmit_bytes, 8384 min(len, ctf_fixed_maxseg(tp))); 8385 counter_u64_add(rack_rtm_prr_retran, 1); 8386 } 8387 } 8388 /* 8389 * Enforce a connection sendmap count limit if set 8390 * as long as we are not retransmiting. 8391 */ 8392 if ((rsm == NULL) && 8393 (rack->do_detection == 0) && 8394 (V_tcp_map_entries_limit > 0) && 8395 (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) { 8396 counter_u64_add(rack_to_alloc_limited, 1); 8397 if (!rack->alloc_limit_reported) { 8398 rack->alloc_limit_reported = 1; 8399 counter_u64_add(rack_alloc_limited_conns, 1); 8400 } 8401 goto just_return_nolock; 8402 } 8403 if (rsm && (rsm->r_flags & RACK_HAS_FIN)) { 8404 /* we are retransmitting the fin */ 8405 len--; 8406 if (len) { 8407 /* 8408 * When retransmitting data do *not* include the 8409 * FIN. This could happen from a TLP probe. 8410 */ 8411 flags &= ~TH_FIN; 8412 } 8413 } 8414 #ifdef INVARIANTS 8415 /* For debugging */ 8416 rack->r_ctl.rc_rsm_at_retran = rsm; 8417 #endif 8418 /* 8419 * Get standard flags, and add SYN or FIN if requested by 'hidden' 8420 * state flags. 8421 */ 8422 if (tp->t_flags & TF_NEEDFIN) 8423 flags |= TH_FIN; 8424 if (tp->t_flags & TF_NEEDSYN) 8425 flags |= TH_SYN; 8426 if ((sack_rxmit == 0) && (prefetch_rsm == 0)) { 8427 void *end_rsm; 8428 end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext); 8429 if (end_rsm) 8430 kern_prefetch(end_rsm, &prefetch_rsm); 8431 prefetch_rsm = 1; 8432 } 8433 SOCKBUF_LOCK(sb); 8434 /* 8435 * If in persist timeout with window of 0, send 1 byte. Otherwise, 8436 * if window is small but nonzero and time TF_SENTFIN expired, we 8437 * will send what we can and go to transmit state. 8438 */ 8439 if (tp->t_flags & TF_FORCEDATA) { 8440 if (sendwin == 0) { 8441 /* 8442 * If we still have some data to send, then clear 8443 * the FIN bit. Usually this would happen below 8444 * when it realizes that we aren't sending all the 8445 * data. However, if we have exactly 1 byte of 8446 * unsent data, then it won't clear the FIN bit 8447 * below, and if we are in persist state, we wind up 8448 * sending the packet without recording that we sent 8449 * the FIN bit. 8450 * 8451 * We can't just blindly clear the FIN bit, because 8452 * if we don't have any more data to send then the 8453 * probe will be the FIN itself. 8454 */ 8455 if (sb_offset < sbused(sb)) 8456 flags &= ~TH_FIN; 8457 sendwin = 1; 8458 } else { 8459 if ((rack->rc_in_persist != 0) && 8460 (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2), 8461 rack->r_ctl.rc_pace_min_segs))) 8462 rack_exit_persist(tp, rack); 8463 /* 8464 * If we are dropping persist mode then we need to 8465 * correct snd_nxt/snd_max and off. 8466 */ 8467 tp->snd_nxt = tp->snd_max; 8468 sb_offset = tp->snd_nxt - tp->snd_una; 8469 } 8470 } 8471 /* 8472 * If snd_nxt == snd_max and we have transmitted a FIN, the 8473 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a 8474 * negative length. This can also occur when TCP opens up its 8475 * congestion window while receiving additional duplicate acks after 8476 * fast-retransmit because TCP will reset snd_nxt to snd_max after 8477 * the fast-retransmit. 8478 * 8479 * In the normal retransmit-FIN-only case, however, snd_nxt will be 8480 * set to snd_una, the sb_offset will be 0, and the length may wind 8481 * up 0. 8482 * 8483 * If sack_rxmit is true we are retransmitting from the scoreboard 8484 * in which case len is already set. 8485 */ 8486 if (sack_rxmit == 0) { 8487 uint32_t avail; 8488 8489 avail = sbavail(sb); 8490 if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail) 8491 sb_offset = tp->snd_nxt - tp->snd_una; 8492 else 8493 sb_offset = 0; 8494 if (IN_RECOVERY(tp->t_flags) == 0) { 8495 if (rack->r_ctl.rc_tlp_new_data) { 8496 /* TLP is forcing out new data */ 8497 if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) { 8498 rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset); 8499 } 8500 if (rack->r_ctl.rc_tlp_new_data > tp->snd_wnd) 8501 len = tp->snd_wnd; 8502 else 8503 len = rack->r_ctl.rc_tlp_new_data; 8504 rack->r_ctl.rc_tlp_new_data = 0; 8505 new_data_tlp = doing_tlp = 1; 8506 } else { 8507 if (sendwin > avail) { 8508 /* use the available */ 8509 if (avail > sb_offset) { 8510 len = (int32_t)(avail - sb_offset); 8511 } else { 8512 len = 0; 8513 } 8514 } else { 8515 if (sendwin > sb_offset) { 8516 len = (int32_t)(sendwin - sb_offset); 8517 } else { 8518 len = 0; 8519 } 8520 } 8521 } 8522 } else { 8523 uint32_t outstanding; 8524 8525 /* 8526 * We are inside of a SACK recovery episode and are 8527 * sending new data, having retransmitted all the 8528 * data possible so far in the scoreboard. 8529 */ 8530 outstanding = tp->snd_max - tp->snd_una; 8531 if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) { 8532 if (tp->snd_wnd > outstanding) { 8533 len = tp->snd_wnd - outstanding; 8534 /* Check to see if we have the data */ 8535 if (((sb_offset + len) > avail) && 8536 (avail > sb_offset)) 8537 len = avail - sb_offset; 8538 else 8539 len = 0; 8540 } else 8541 len = 0; 8542 } else if (avail > sb_offset) 8543 len = avail - sb_offset; 8544 else 8545 len = 0; 8546 if (len > 0) { 8547 if (len > rack->r_ctl.rc_prr_sndcnt) 8548 len = rack->r_ctl.rc_prr_sndcnt; 8549 if (len > 0) { 8550 sub_from_prr = 1; 8551 counter_u64_add(rack_rtm_prr_newdata, 1); 8552 } 8553 } 8554 if (len > ctf_fixed_maxseg(tp)) { 8555 /* 8556 * We should never send more than a MSS when 8557 * retransmitting or sending new data in prr 8558 * mode unless the override flag is on. Most 8559 * likely the PRR algorithm is not going to 8560 * let us send a lot as well :-) 8561 */ 8562 if (rack->r_ctl.rc_prr_sendalot == 0) 8563 len = ctf_fixed_maxseg(tp); 8564 } else if (len < ctf_fixed_maxseg(tp)) { 8565 /* 8566 * Do we send any? The idea here is if the 8567 * send empty's the socket buffer we want to 8568 * do it. However if not then lets just wait 8569 * for our prr_sndcnt to get bigger. 8570 */ 8571 long leftinsb; 8572 8573 leftinsb = sbavail(sb) - sb_offset; 8574 if (leftinsb > len) { 8575 /* This send does not empty the sb */ 8576 len = 0; 8577 } 8578 } 8579 } 8580 } 8581 if (prefetch_so_done == 0) { 8582 kern_prefetch(so, &prefetch_so_done); 8583 prefetch_so_done = 1; 8584 } 8585 /* 8586 * Lop off SYN bit if it has already been sent. However, if this is 8587 * SYN-SENT state and if segment contains data and if we don't know 8588 * that foreign host supports TAO, suppress sending segment. 8589 */ 8590 if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) && 8591 ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) { 8592 if (tp->t_state != TCPS_SYN_RECEIVED) 8593 flags &= ~TH_SYN; 8594 /* 8595 * When sending additional segments following a TFO SYN|ACK, 8596 * do not include the SYN bit. 8597 */ 8598 if (IS_FASTOPEN(tp->t_flags) && 8599 (tp->t_state == TCPS_SYN_RECEIVED)) 8600 flags &= ~TH_SYN; 8601 sb_offset--, len++; 8602 } 8603 /* 8604 * Be careful not to send data and/or FIN on SYN segments. This 8605 * measure is needed to prevent interoperability problems with not 8606 * fully conformant TCP implementations. 8607 */ 8608 if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) { 8609 len = 0; 8610 flags &= ~TH_FIN; 8611 } 8612 /* 8613 * On TFO sockets, ensure no data is sent in the following cases: 8614 * 8615 * - When retransmitting SYN|ACK on a passively-created socket 8616 * 8617 * - When retransmitting SYN on an actively created socket 8618 * 8619 * - When sending a zero-length cookie (cookie request) on an 8620 * actively created socket 8621 * 8622 * - When the socket is in the CLOSED state (RST is being sent) 8623 */ 8624 if (IS_FASTOPEN(tp->t_flags) && 8625 (((flags & TH_SYN) && (tp->t_rxtshift > 0)) || 8626 ((tp->t_state == TCPS_SYN_SENT) && 8627 (tp->t_tfo_client_cookie_len == 0)) || 8628 (flags & TH_RST))) { 8629 sack_rxmit = 0; 8630 len = 0; 8631 } 8632 /* Without fast-open there should never be data sent on a SYN */ 8633 if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) 8634 len = 0; 8635 orig_len = len; 8636 if (len <= 0) { 8637 /* 8638 * If FIN has been sent but not acked, but we haven't been 8639 * called to retransmit, len will be < 0. Otherwise, window 8640 * shrank after we sent into it. If window shrank to 0, 8641 * cancel pending retransmit, pull snd_nxt back to (closed) 8642 * window, and set the persist timer if it isn't already 8643 * going. If the window didn't close completely, just wait 8644 * for an ACK. 8645 * 8646 * We also do a general check here to ensure that we will 8647 * set the persist timer when we have data to send, but a 8648 * 0-byte window. This makes sure the persist timer is set 8649 * even if the packet hits one of the "goto send" lines 8650 * below. 8651 */ 8652 len = 0; 8653 if ((tp->snd_wnd == 0) && 8654 (TCPS_HAVEESTABLISHED(tp->t_state)) && 8655 (tp->snd_una == tp->snd_max) && 8656 (sb_offset < (int)sbavail(sb))) { 8657 tp->snd_nxt = tp->snd_una; 8658 rack_enter_persist(tp, rack, cts); 8659 } 8660 } else if ((rsm == NULL) && 8661 ((doing_tlp == 0) || (new_data_tlp == 1)) && 8662 (len < rack->r_ctl.rc_pace_max_segs)) { 8663 /* 8664 * We are not sending a full segment for 8665 * some reason. Should we not send anything (think 8666 * sws or persists)? 8667 */ 8668 if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) && 8669 (TCPS_HAVEESTABLISHED(tp->t_state)) && 8670 (len < (int)(sbavail(sb) - sb_offset))) { 8671 /* 8672 * Here the rwnd is less than 8673 * the pacing size, this is not a retransmit, 8674 * we are established and 8675 * the send is not the last in the socket buffer 8676 * we send nothing, and may enter persists. 8677 */ 8678 len = 0; 8679 if (tp->snd_max == tp->snd_una) { 8680 /* 8681 * Nothing out we can 8682 * go into persists. 8683 */ 8684 rack_enter_persist(tp, rack, cts); 8685 tp->snd_nxt = tp->snd_una; 8686 } 8687 } else if ((tp->snd_cwnd >= max(rack->r_ctl.rc_pace_min_segs, (maxseg * 4))) && 8688 (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * maxseg)) && 8689 (len < (int)(sbavail(sb) - sb_offset)) && 8690 (len < rack->r_ctl.rc_pace_min_segs)) { 8691 /* 8692 * Here we are not retransmitting, and 8693 * the cwnd is not so small that we could 8694 * not send at least a min size (rxt timer 8695 * not having gone off), We have 2 segments or 8696 * more already in flight, its not the tail end 8697 * of the socket buffer and the cwnd is blocking 8698 * us from sending out a minimum pacing segment size. 8699 * Lets not send anything. 8700 */ 8701 len = 0; 8702 } else if (((tp->snd_wnd - ctf_outstanding(tp)) < 8703 min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) && 8704 (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * maxseg)) && 8705 (len < (int)(sbavail(sb) - sb_offset)) && 8706 (TCPS_HAVEESTABLISHED(tp->t_state))) { 8707 /* 8708 * Here we have a send window but we have 8709 * filled it up and we can't send another pacing segment. 8710 * We also have in flight more than 2 segments 8711 * and we are not completing the sb i.e. we allow 8712 * the last bytes of the sb to go out even if 8713 * its not a full pacing segment. 8714 */ 8715 len = 0; 8716 } 8717 } 8718 /* len will be >= 0 after this point. */ 8719 KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__)); 8720 tcp_sndbuf_autoscale(tp, so, sendwin); 8721 /* 8722 * Decide if we can use TCP Segmentation Offloading (if supported by 8723 * hardware). 8724 * 8725 * TSO may only be used if we are in a pure bulk sending state. The 8726 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP 8727 * options prevent using TSO. With TSO the TCP header is the same 8728 * (except for the sequence number) for all generated packets. This 8729 * makes it impossible to transmit any options which vary per 8730 * generated segment or packet. 8731 * 8732 * IPv4 handling has a clear separation of ip options and ip header 8733 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does 8734 * the right thing below to provide length of just ip options and thus 8735 * checking for ipoptlen is enough to decide if ip options are present. 8736 */ 8737 8738 #ifdef INET6 8739 if (isipv6) 8740 ipoptlen = ip6_optlen(tp->t_inpcb); 8741 else 8742 #endif 8743 if (tp->t_inpcb->inp_options) 8744 ipoptlen = tp->t_inpcb->inp_options->m_len - 8745 offsetof(struct ipoption, ipopt_list); 8746 else 8747 ipoptlen = 0; 8748 #if defined(IPSEC) || defined(IPSEC_SUPPORT) 8749 /* 8750 * Pre-calculate here as we save another lookup into the darknesses 8751 * of IPsec that way and can actually decide if TSO is ok. 8752 */ 8753 #ifdef INET6 8754 if (isipv6 && IPSEC_ENABLED(ipv6)) 8755 ipsec_optlen = IPSEC_HDRSIZE(ipv6, tp->t_inpcb); 8756 #ifdef INET 8757 else 8758 #endif 8759 #endif /* INET6 */ 8760 #ifdef INET 8761 if (IPSEC_ENABLED(ipv4)) 8762 ipsec_optlen = IPSEC_HDRSIZE(ipv4, tp->t_inpcb); 8763 #endif /* INET */ 8764 #endif 8765 8766 #if defined(IPSEC) || defined(IPSEC_SUPPORT) 8767 ipoptlen += ipsec_optlen; 8768 #endif 8769 if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > ctf_fixed_maxseg(tp) && 8770 (tp->t_port == 0) && 8771 ((tp->t_flags & TF_SIGNATURE) == 0) && 8772 tp->rcv_numsacks == 0 && sack_rxmit == 0 && 8773 ipoptlen == 0) 8774 tso = 1; 8775 { 8776 uint32_t outstanding; 8777 8778 outstanding = tp->snd_max - tp->snd_una; 8779 if (tp->t_flags & TF_SENTFIN) { 8780 /* 8781 * If we sent a fin, snd_max is 1 higher than 8782 * snd_una 8783 */ 8784 outstanding--; 8785 } 8786 if (sack_rxmit) { 8787 if ((rsm->r_flags & RACK_HAS_FIN) == 0) 8788 flags &= ~TH_FIN; 8789 } else { 8790 if (SEQ_LT(tp->snd_nxt + len, tp->snd_una + 8791 sbused(sb))) 8792 flags &= ~TH_FIN; 8793 } 8794 } 8795 recwin = sbspace(&so->so_rcv); 8796 8797 /* 8798 * Sender silly window avoidance. We transmit under the following 8799 * conditions when len is non-zero: 8800 * 8801 * - We have a full segment (or more with TSO) - This is the last 8802 * buffer in a write()/send() and we are either idle or running 8803 * NODELAY - we've timed out (e.g. persist timer) - we have more 8804 * then 1/2 the maximum send window's worth of data (receiver may be 8805 * limited the window size) - we need to retransmit 8806 */ 8807 if (len) { 8808 if (len >= ctf_fixed_maxseg(tp)) { 8809 pass = 1; 8810 goto send; 8811 } 8812 /* 8813 * NOTE! on localhost connections an 'ack' from the remote 8814 * end may occur synchronously with the output and cause us 8815 * to flush a buffer queued with moretocome. XXX 8816 * 8817 */ 8818 if (!(tp->t_flags & TF_MORETOCOME) && /* normal case */ 8819 (idle || (tp->t_flags & TF_NODELAY)) && 8820 ((uint32_t)len + (uint32_t)sb_offset >= sbavail(&so->so_snd)) && 8821 (tp->t_flags & TF_NOPUSH) == 0) { 8822 pass = 2; 8823 goto send; 8824 } 8825 if (tp->t_flags & TF_FORCEDATA) { /* typ. timeout case */ 8826 pass = 3; 8827 goto send; 8828 } 8829 if ((tp->snd_una == tp->snd_max) && len) { /* Nothing outstanding */ 8830 goto send; 8831 } 8832 if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) { 8833 pass = 4; 8834 goto send; 8835 } 8836 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) { /* retransmit case */ 8837 pass = 5; 8838 goto send; 8839 } 8840 if (sack_rxmit) { 8841 pass = 6; 8842 goto send; 8843 } 8844 } 8845 /* 8846 * Sending of standalone window updates. 8847 * 8848 * Window updates are important when we close our window due to a 8849 * full socket buffer and are opening it again after the application 8850 * reads data from it. Once the window has opened again and the 8851 * remote end starts to send again the ACK clock takes over and 8852 * provides the most current window information. 8853 * 8854 * We must avoid the silly window syndrome whereas every read from 8855 * the receive buffer, no matter how small, causes a window update 8856 * to be sent. We also should avoid sending a flurry of window 8857 * updates when the socket buffer had queued a lot of data and the 8858 * application is doing small reads. 8859 * 8860 * Prevent a flurry of pointless window updates by only sending an 8861 * update when we can increase the advertized window by more than 8862 * 1/4th of the socket buffer capacity. When the buffer is getting 8863 * full or is very small be more aggressive and send an update 8864 * whenever we can increase by two mss sized segments. In all other 8865 * situations the ACK's to new incoming data will carry further 8866 * window increases. 8867 * 8868 * Don't send an independent window update if a delayed ACK is 8869 * pending (it will get piggy-backed on it) or the remote side 8870 * already has done a half-close and won't send more data. Skip 8871 * this if the connection is in T/TCP half-open state. 8872 */ 8873 if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) && 8874 !(tp->t_flags & TF_DELACK) && 8875 !TCPS_HAVERCVDFIN(tp->t_state)) { 8876 /* 8877 * "adv" is the amount we could increase the window, taking 8878 * into account that we are limited by TCP_MAXWIN << 8879 * tp->rcv_scale. 8880 */ 8881 int32_t adv; 8882 int oldwin; 8883 8884 adv = min(recwin, (long)TCP_MAXWIN << tp->rcv_scale); 8885 if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) { 8886 oldwin = (tp->rcv_adv - tp->rcv_nxt); 8887 adv -= oldwin; 8888 } else 8889 oldwin = 0; 8890 8891 /* 8892 * If the new window size ends up being the same as the old 8893 * size when it is scaled, then don't force a window update. 8894 */ 8895 if (oldwin >> tp->rcv_scale == (adv + oldwin) >> tp->rcv_scale) 8896 goto dontupdate; 8897 8898 if (adv >= (int32_t)(2 * ctf_fixed_maxseg(tp)) && 8899 (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) || 8900 recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) || 8901 so->so_rcv.sb_hiwat <= 8 * ctf_fixed_maxseg(tp))) { 8902 pass = 7; 8903 goto send; 8904 } 8905 if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) 8906 goto send; 8907 } 8908 dontupdate: 8909 8910 /* 8911 * Send if we owe the peer an ACK, RST, SYN, or urgent data. ACKNOW 8912 * is also a catch-all for the retransmit timer timeout case. 8913 */ 8914 if (tp->t_flags & TF_ACKNOW) { 8915 pass = 8; 8916 goto send; 8917 } 8918 if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) { 8919 pass = 9; 8920 goto send; 8921 } 8922 if (SEQ_GT(tp->snd_up, tp->snd_una)) { 8923 pass = 10; 8924 goto send; 8925 } 8926 /* 8927 * If our state indicates that FIN should be sent and we have not 8928 * yet done so, then we need to send. 8929 */ 8930 if ((flags & TH_FIN) && 8931 (tp->snd_nxt == tp->snd_una)) { 8932 pass = 11; 8933 goto send; 8934 } 8935 /* 8936 * No reason to send a segment, just return. 8937 */ 8938 just_return: 8939 SOCKBUF_UNLOCK(sb); 8940 just_return_nolock: 8941 if (tot_len_this_send == 0) 8942 counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1); 8943 if (slot) { 8944 /* set the rack tcb into the slot N */ 8945 counter_u64_add(rack_paced_segments, 1); 8946 } else if (tot_len_this_send) { 8947 counter_u64_add(rack_unpaced_segments, 1); 8948 } 8949 /* Check if we need to go into persists or not */ 8950 if ((rack->rc_in_persist == 0) && 8951 (tp->snd_max == tp->snd_una) && 8952 TCPS_HAVEESTABLISHED(tp->t_state) && 8953 sbavail(&tp->t_inpcb->inp_socket->so_snd) && 8954 (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd) && 8955 (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs))) { 8956 /* Yes lets make sure to move to persist before timer-start */ 8957 rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime); 8958 } 8959 rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack); 8960 rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling); 8961 tp->t_flags &= ~TF_FORCEDATA; 8962 return (0); 8963 8964 send: 8965 if ((flags & TH_FIN) && 8966 sbavail(&tp->t_inpcb->inp_socket->so_snd)) { 8967 /* 8968 * We do not transmit a FIN 8969 * with data outstanding. We 8970 * need to make it so all data 8971 * is acked first. 8972 */ 8973 flags &= ~TH_FIN; 8974 } 8975 if (doing_tlp == 0) { 8976 /* 8977 * Data not a TLP, and its not the rxt firing. If it is the 8978 * rxt firing, we want to leave the tlp_in_progress flag on 8979 * so we don't send another TLP. It has to be a rack timer 8980 * or normal send (response to acked data) to clear the tlp 8981 * in progress flag. 8982 */ 8983 rack->rc_tlp_in_progress = 0; 8984 } 8985 SOCKBUF_LOCK_ASSERT(sb); 8986 if (len > 0) { 8987 if (len >= ctf_fixed_maxseg(tp)) 8988 tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT; 8989 else 8990 tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT; 8991 } 8992 /* 8993 * Before ESTABLISHED, force sending of initial options unless TCP 8994 * set not to do any options. NOTE: we assume that the IP/TCP header 8995 * plus TCP options always fit in a single mbuf, leaving room for a 8996 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr) 8997 * + optlen <= MCLBYTES 8998 */ 8999 optlen = 0; 9000 #ifdef INET6 9001 if (isipv6) 9002 hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 9003 else 9004 #endif 9005 hdrlen = sizeof(struct tcpiphdr); 9006 9007 /* 9008 * Compute options for segment. We only have to care about SYN and 9009 * established connection segments. Options for SYN-ACK segments 9010 * are handled in TCP syncache. 9011 */ 9012 to.to_flags = 0; 9013 if ((tp->t_flags & TF_NOOPT) == 0) { 9014 /* Maximum segment size. */ 9015 if (flags & TH_SYN) { 9016 tp->snd_nxt = tp->iss; 9017 to.to_mss = tcp_mssopt(&inp->inp_inc); 9018 #ifdef NETFLIX_TCPOUDP 9019 if (tp->t_port) 9020 to.to_mss -= V_tcp_udp_tunneling_overhead; 9021 #endif 9022 to.to_flags |= TOF_MSS; 9023 9024 /* 9025 * On SYN or SYN|ACK transmits on TFO connections, 9026 * only include the TFO option if it is not a 9027 * retransmit, as the presence of the TFO option may 9028 * have caused the original SYN or SYN|ACK to have 9029 * been dropped by a middlebox. 9030 */ 9031 if (IS_FASTOPEN(tp->t_flags) && 9032 (tp->t_rxtshift == 0)) { 9033 if (tp->t_state == TCPS_SYN_RECEIVED) { 9034 to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN; 9035 to.to_tfo_cookie = 9036 (u_int8_t *)&tp->t_tfo_cookie.server; 9037 to.to_flags |= TOF_FASTOPEN; 9038 wanted_cookie = 1; 9039 } else if (tp->t_state == TCPS_SYN_SENT) { 9040 to.to_tfo_len = 9041 tp->t_tfo_client_cookie_len; 9042 to.to_tfo_cookie = 9043 tp->t_tfo_cookie.client; 9044 to.to_flags |= TOF_FASTOPEN; 9045 wanted_cookie = 1; 9046 /* 9047 * If we wind up having more data to 9048 * send with the SYN than can fit in 9049 * one segment, don't send any more 9050 * until the SYN|ACK comes back from 9051 * the other end. 9052 */ 9053 sendalot = 0; 9054 } 9055 } 9056 } 9057 /* Window scaling. */ 9058 if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) { 9059 to.to_wscale = tp->request_r_scale; 9060 to.to_flags |= TOF_SCALE; 9061 } 9062 /* Timestamps. */ 9063 if ((tp->t_flags & TF_RCVD_TSTMP) || 9064 ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) { 9065 to.to_tsval = cts + tp->ts_offset; 9066 to.to_tsecr = tp->ts_recent; 9067 to.to_flags |= TOF_TS; 9068 } 9069 /* Set receive buffer autosizing timestamp. */ 9070 if (tp->rfbuf_ts == 0 && 9071 (so->so_rcv.sb_flags & SB_AUTOSIZE)) 9072 tp->rfbuf_ts = tcp_ts_getticks(); 9073 /* Selective ACK's. */ 9074 if (flags & TH_SYN) 9075 to.to_flags |= TOF_SACKPERM; 9076 else if (TCPS_HAVEESTABLISHED(tp->t_state) && 9077 tp->rcv_numsacks > 0) { 9078 to.to_flags |= TOF_SACK; 9079 to.to_nsacks = tp->rcv_numsacks; 9080 to.to_sacks = (u_char *)tp->sackblks; 9081 } 9082 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 9083 /* TCP-MD5 (RFC2385). */ 9084 if (tp->t_flags & TF_SIGNATURE) 9085 to.to_flags |= TOF_SIGNATURE; 9086 #endif /* TCP_SIGNATURE */ 9087 9088 /* Processing the options. */ 9089 hdrlen += optlen = tcp_addoptions(&to, opt); 9090 /* 9091 * If we wanted a TFO option to be added, but it was unable 9092 * to fit, ensure no data is sent. 9093 */ 9094 if (IS_FASTOPEN(tp->t_flags) && wanted_cookie && 9095 !(to.to_flags & TOF_FASTOPEN)) 9096 len = 0; 9097 } 9098 #ifdef NETFLIX_TCPOUDP 9099 if (tp->t_port) { 9100 if (V_tcp_udp_tunneling_port == 0) { 9101 /* The port was removed?? */ 9102 SOCKBUF_UNLOCK(&so->so_snd); 9103 return (EHOSTUNREACH); 9104 } 9105 hdrlen += sizeof(struct udphdr); 9106 } 9107 #endif 9108 #ifdef INET6 9109 if (isipv6) 9110 ipoptlen = ip6_optlen(tp->t_inpcb); 9111 else 9112 #endif 9113 if (tp->t_inpcb->inp_options) 9114 ipoptlen = tp->t_inpcb->inp_options->m_len - 9115 offsetof(struct ipoption, ipopt_list); 9116 else 9117 ipoptlen = 0; 9118 #if defined(IPSEC) || defined(IPSEC_SUPPORT) 9119 ipoptlen += ipsec_optlen; 9120 #endif 9121 9122 #ifdef KERN_TLS 9123 /* force TSO for so TLS offload can get mss */ 9124 if (sb->sb_flags & SB_TLS_IFNET) { 9125 force_tso = 1; 9126 } 9127 #endif 9128 /* 9129 * Adjust data length if insertion of options will bump the packet 9130 * length beyond the t_maxseg length. Clear the FIN bit because we 9131 * cut off the tail of the segment. 9132 */ 9133 if (len + optlen + ipoptlen > tp->t_maxseg) { 9134 if (tso) { 9135 uint32_t if_hw_tsomax; 9136 uint32_t moff; 9137 int32_t max_len; 9138 9139 /* extract TSO information */ 9140 if_hw_tsomax = tp->t_tsomax; 9141 if_hw_tsomaxsegcount = tp->t_tsomaxsegcount; 9142 if_hw_tsomaxsegsize = tp->t_tsomaxsegsize; 9143 KASSERT(ipoptlen == 0, 9144 ("%s: TSO can't do IP options", __func__)); 9145 9146 /* 9147 * Check if we should limit by maximum payload 9148 * length: 9149 */ 9150 if (if_hw_tsomax != 0) { 9151 /* compute maximum TSO length */ 9152 max_len = (if_hw_tsomax - hdrlen - 9153 max_linkhdr); 9154 if (max_len <= 0) { 9155 len = 0; 9156 } else if (len > max_len) { 9157 sendalot = 1; 9158 len = max_len; 9159 } 9160 } 9161 /* 9162 * Prevent the last segment from being fractional 9163 * unless the send sockbuf can be emptied: 9164 */ 9165 max_len = (tp->t_maxseg - optlen); 9166 if (((sb_offset + len) < sbavail(sb)) && 9167 (hw_tls == 0)) { 9168 moff = len % (u_int)max_len; 9169 if (moff != 0) { 9170 len -= moff; 9171 sendalot = 1; 9172 } 9173 } 9174 /* 9175 * In case there are too many small fragments don't 9176 * use TSO: 9177 */ 9178 if (len <= maxseg) { 9179 len = max_len; 9180 sendalot = 1; 9181 tso = 0; 9182 } 9183 /* 9184 * Send the FIN in a separate segment after the bulk 9185 * sending is done. We don't trust the TSO 9186 * implementations to clear the FIN flag on all but 9187 * the last segment. 9188 */ 9189 if (tp->t_flags & TF_NEEDFIN) 9190 sendalot = 1; 9191 9192 } else { 9193 if (optlen + ipoptlen >= tp->t_maxseg) { 9194 /* 9195 * Since we don't have enough space to put 9196 * the IP header chain and the TCP header in 9197 * one packet as required by RFC 7112, don't 9198 * send it. Also ensure that at least one 9199 * byte of the payload can be put into the 9200 * TCP segment. 9201 */ 9202 SOCKBUF_UNLOCK(&so->so_snd); 9203 error = EMSGSIZE; 9204 sack_rxmit = 0; 9205 goto out; 9206 } 9207 len = tp->t_maxseg - optlen - ipoptlen; 9208 sendalot = 1; 9209 } 9210 } else 9211 tso = 0; 9212 KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET, 9213 ("%s: len > IP_MAXPACKET", __func__)); 9214 #ifdef DIAGNOSTIC 9215 #ifdef INET6 9216 if (max_linkhdr + hdrlen > MCLBYTES) 9217 #else 9218 if (max_linkhdr + hdrlen > MHLEN) 9219 #endif 9220 panic("tcphdr too big"); 9221 #endif 9222 9223 /* 9224 * This KASSERT is here to catch edge cases at a well defined place. 9225 * Before, those had triggered (random) panic conditions further 9226 * down. 9227 */ 9228 KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__)); 9229 if ((len == 0) && 9230 (flags & TH_FIN) && 9231 (sbused(sb))) { 9232 /* 9233 * We have outstanding data, don't send a fin by itself!. 9234 */ 9235 goto just_return; 9236 } 9237 /* 9238 * Grab a header mbuf, attaching a copy of data to be transmitted, 9239 * and initialize the header from the template for sends on this 9240 * connection. 9241 */ 9242 if (len) { 9243 uint32_t max_val; 9244 uint32_t moff; 9245 9246 if (rack->rc_pace_max_segs) 9247 max_val = rack->rc_pace_max_segs * ctf_fixed_maxseg(tp); 9248 else 9249 max_val = len; 9250 if (rack->r_ctl.rc_pace_max_segs < max_val) 9251 max_val = rack->r_ctl.rc_pace_max_segs; 9252 /* 9253 * We allow a limit on sending with hptsi. 9254 */ 9255 if (len > max_val) { 9256 len = max_val; 9257 } 9258 #ifdef INET6 9259 if (MHLEN < hdrlen + max_linkhdr) 9260 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 9261 else 9262 #endif 9263 m = m_gethdr(M_NOWAIT, MT_DATA); 9264 9265 if (m == NULL) { 9266 SOCKBUF_UNLOCK(sb); 9267 error = ENOBUFS; 9268 sack_rxmit = 0; 9269 goto out; 9270 } 9271 m->m_data += max_linkhdr; 9272 m->m_len = hdrlen; 9273 9274 /* 9275 * Start the m_copy functions from the closest mbuf to the 9276 * sb_offset in the socket buffer chain. 9277 */ 9278 mb = sbsndptr_noadv(sb, sb_offset, &moff); 9279 if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) { 9280 m_copydata(mb, moff, (int)len, 9281 mtod(m, caddr_t)+hdrlen); 9282 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) 9283 sbsndptr_adv(sb, mb, len); 9284 m->m_len += len; 9285 } else { 9286 struct sockbuf *msb; 9287 9288 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) 9289 msb = NULL; 9290 else 9291 msb = sb; 9292 m->m_next = tcp_m_copym( 9293 #ifdef NETFLIX_COPY_ARGS 9294 tp, 9295 #endif 9296 mb, moff, &len, 9297 if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb, 9298 ((rsm == NULL) ? hw_tls : 0) 9299 #ifdef NETFLIX_COPY_ARGS 9300 , &filled_all 9301 #endif 9302 ); 9303 if (len <= (tp->t_maxseg - optlen)) { 9304 /* 9305 * Must have ran out of mbufs for the copy 9306 * shorten it to no longer need tso. Lets 9307 * not put on sendalot since we are low on 9308 * mbufs. 9309 */ 9310 tso = 0; 9311 } 9312 if (m->m_next == NULL) { 9313 SOCKBUF_UNLOCK(sb); 9314 (void)m_free(m); 9315 error = ENOBUFS; 9316 sack_rxmit = 0; 9317 goto out; 9318 } 9319 } 9320 if ((tp->t_flags & TF_FORCEDATA) && len == 1) { 9321 TCPSTAT_INC(tcps_sndprobe); 9322 #ifdef STATS 9323 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) 9324 stats_voi_update_abs_u32(tp->t_stats, 9325 VOI_TCP_RETXPB, len); 9326 else 9327 stats_voi_update_abs_u64(tp->t_stats, 9328 VOI_TCP_TXPB, len); 9329 #endif 9330 } else if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) { 9331 if (rsm && (rsm->r_flags & RACK_TLP)) { 9332 /* 9333 * TLP should not count in retran count, but 9334 * in its own bin 9335 */ 9336 counter_u64_add(rack_tlp_retran, 1); 9337 counter_u64_add(rack_tlp_retran_bytes, len); 9338 } else { 9339 tp->t_sndrexmitpack++; 9340 TCPSTAT_INC(tcps_sndrexmitpack); 9341 TCPSTAT_ADD(tcps_sndrexmitbyte, len); 9342 } 9343 #ifdef STATS 9344 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB, 9345 len); 9346 #endif 9347 } else { 9348 TCPSTAT_INC(tcps_sndpack); 9349 TCPSTAT_ADD(tcps_sndbyte, len); 9350 #ifdef STATS 9351 stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB, 9352 len); 9353 #endif 9354 } 9355 /* 9356 * If we're sending everything we've got, set PUSH. (This 9357 * will keep happy those implementations which only give 9358 * data to the user when a buffer fills or a PUSH comes in.) 9359 */ 9360 if (sb_offset + len == sbused(sb) && 9361 sbused(sb) && 9362 !(flags & TH_SYN)) 9363 flags |= TH_PUSH; 9364 9365 /* 9366 * Are we doing pacing, if so we must calculate the slot. We 9367 * only do hptsi in ESTABLISHED and with no RESET being 9368 * sent where we have data to send. 9369 */ 9370 if (((tp->t_state == TCPS_ESTABLISHED) || 9371 (tp->t_state == TCPS_CLOSE_WAIT) || 9372 ((tp->t_state == TCPS_FIN_WAIT_1) && 9373 ((tp->t_flags & TF_SENTFIN) == 0) && 9374 ((flags & TH_FIN) == 0))) && 9375 ((flags & TH_RST) == 0)) { 9376 /* Get our pacing rate */ 9377 tot_len_this_send += len; 9378 slot = rack_get_pacing_delay(rack, tp, tot_len_this_send); 9379 } 9380 SOCKBUF_UNLOCK(sb); 9381 } else { 9382 SOCKBUF_UNLOCK(sb); 9383 if (tp->t_flags & TF_ACKNOW) 9384 TCPSTAT_INC(tcps_sndacks); 9385 else if (flags & (TH_SYN | TH_FIN | TH_RST)) 9386 TCPSTAT_INC(tcps_sndctrl); 9387 else if (SEQ_GT(tp->snd_up, tp->snd_una)) 9388 TCPSTAT_INC(tcps_sndurg); 9389 else 9390 TCPSTAT_INC(tcps_sndwinup); 9391 9392 m = m_gethdr(M_NOWAIT, MT_DATA); 9393 if (m == NULL) { 9394 error = ENOBUFS; 9395 sack_rxmit = 0; 9396 goto out; 9397 } 9398 #ifdef INET6 9399 if (isipv6 && (MHLEN < hdrlen + max_linkhdr) && 9400 MHLEN >= hdrlen) { 9401 M_ALIGN(m, hdrlen); 9402 } else 9403 #endif 9404 m->m_data += max_linkhdr; 9405 m->m_len = hdrlen; 9406 } 9407 SOCKBUF_UNLOCK_ASSERT(sb); 9408 m->m_pkthdr.rcvif = (struct ifnet *)0; 9409 #ifdef MAC 9410 mac_inpcb_create_mbuf(inp, m); 9411 #endif 9412 #ifdef INET6 9413 if (isipv6) { 9414 ip6 = mtod(m, struct ip6_hdr *); 9415 #ifdef NETFLIX_TCPOUDP 9416 if (tp->t_port) { 9417 udp = (struct udphdr *)((caddr_t)ip6 + ipoptlen + sizeof(struct ip6_hdr)); 9418 udp->uh_sport = htons(V_tcp_udp_tunneling_port); 9419 udp->uh_dport = tp->t_port; 9420 ulen = hdrlen + len - sizeof(struct ip6_hdr); 9421 udp->uh_ulen = htons(ulen); 9422 th = (struct tcphdr *)(udp + 1); 9423 } else 9424 #endif 9425 th = (struct tcphdr *)(ip6 + 1); 9426 tcpip_fillheaders(inp, 9427 #ifdef NETFLIX_TCPOUDP 9428 tp->t_port, 9429 #endif 9430 ip6, th); 9431 } else 9432 #endif /* INET6 */ 9433 { 9434 ip = mtod(m, struct ip *); 9435 #ifdef TCPDEBUG 9436 ipov = (struct ipovly *)ip; 9437 #endif 9438 #ifdef NETFLIX_TCPOUDP 9439 if (tp->t_port) { 9440 udp = (struct udphdr *)((caddr_t)ip + ipoptlen + sizeof(struct ip)); 9441 udp->uh_sport = htons(V_tcp_udp_tunneling_port); 9442 udp->uh_dport = tp->t_port; 9443 ulen = hdrlen + len - sizeof(struct ip); 9444 udp->uh_ulen = htons(ulen); 9445 th = (struct tcphdr *)(udp + 1); 9446 } else 9447 #endif 9448 th = (struct tcphdr *)(ip + 1); 9449 tcpip_fillheaders(inp, 9450 #ifdef NETFLIX_TCPOUDP 9451 tp->t_port, 9452 #endif 9453 ip, th); 9454 } 9455 /* 9456 * Fill in fields, remembering maximum advertised window for use in 9457 * delaying messages about window sizes. If resending a FIN, be sure 9458 * not to use a new sequence number. 9459 */ 9460 if (flags & TH_FIN && tp->t_flags & TF_SENTFIN && 9461 tp->snd_nxt == tp->snd_max) 9462 tp->snd_nxt--; 9463 /* 9464 * If we are starting a connection, send ECN setup SYN packet. If we 9465 * are on a retransmit, we may resend those bits a number of times 9466 * as per RFC 3168. 9467 */ 9468 if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn == 1) { 9469 if (tp->t_rxtshift >= 1) { 9470 if (tp->t_rxtshift <= V_tcp_ecn_maxretries) 9471 flags |= TH_ECE | TH_CWR; 9472 } else 9473 flags |= TH_ECE | TH_CWR; 9474 } 9475 if (tp->t_state == TCPS_ESTABLISHED && 9476 (tp->t_flags2 & TF2_ECN_PERMIT)) { 9477 /* 9478 * If the peer has ECN, mark data packets with ECN capable 9479 * transmission (ECT). Ignore pure ack packets, 9480 * retransmissions and window probes. 9481 */ 9482 if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) && 9483 (sack_rxmit == 0) && 9484 !((tp->t_flags & TF_FORCEDATA) && len == 1)) { 9485 #ifdef INET6 9486 if (isipv6) 9487 ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20); 9488 else 9489 #endif 9490 ip->ip_tos |= IPTOS_ECN_ECT0; 9491 TCPSTAT_INC(tcps_ecn_ect0); 9492 } 9493 /* 9494 * Reply with proper ECN notifications. 9495 */ 9496 if (tp->t_flags2 & TF2_ECN_SND_CWR) { 9497 flags |= TH_CWR; 9498 tp->t_flags2 &= ~TF2_ECN_SND_CWR; 9499 } 9500 if (tp->t_flags2 & TF2_ECN_SND_ECE) 9501 flags |= TH_ECE; 9502 } 9503 /* 9504 * If we are doing retransmissions, then snd_nxt will not reflect 9505 * the first unsent octet. For ACK only packets, we do not want the 9506 * sequence number of the retransmitted packet, we want the sequence 9507 * number of the next unsent octet. So, if there is no data (and no 9508 * SYN or FIN), use snd_max instead of snd_nxt when filling in 9509 * ti_seq. But if we are in persist state, snd_max might reflect 9510 * one byte beyond the right edge of the window, so use snd_nxt in 9511 * that case, since we know we aren't doing a retransmission. 9512 * (retransmit and persist are mutually exclusive...) 9513 */ 9514 if (sack_rxmit == 0) { 9515 if (len || (flags & (TH_SYN | TH_FIN)) || 9516 rack->rc_in_persist) { 9517 th->th_seq = htonl(tp->snd_nxt); 9518 rack_seq = tp->snd_nxt; 9519 } else if (flags & TH_RST) { 9520 /* 9521 * For a Reset send the last cum ack in sequence 9522 * (this like any other choice may still generate a 9523 * challenge ack, if a ack-update packet is in 9524 * flight). 9525 */ 9526 th->th_seq = htonl(tp->snd_una); 9527 rack_seq = tp->snd_una; 9528 } else { 9529 th->th_seq = htonl(tp->snd_max); 9530 rack_seq = tp->snd_max; 9531 } 9532 } else { 9533 th->th_seq = htonl(rsm->r_start); 9534 rack_seq = rsm->r_start; 9535 } 9536 th->th_ack = htonl(tp->rcv_nxt); 9537 if (optlen) { 9538 bcopy(opt, th + 1, optlen); 9539 th->th_off = (sizeof(struct tcphdr) + optlen) >> 2; 9540 } 9541 th->th_flags = flags; 9542 /* 9543 * Calculate receive window. Don't shrink window, but avoid silly 9544 * window syndrome. 9545 * If a RST segment is sent, advertise a window of zero. 9546 */ 9547 if (flags & TH_RST) { 9548 recwin = 0; 9549 } else { 9550 if (recwin < (long)(so->so_rcv.sb_hiwat / 4) && 9551 recwin < (long)ctf_fixed_maxseg(tp)) 9552 recwin = 0; 9553 if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) && 9554 recwin < (long)(tp->rcv_adv - tp->rcv_nxt)) 9555 recwin = (long)(tp->rcv_adv - tp->rcv_nxt); 9556 if (recwin > (long)TCP_MAXWIN << tp->rcv_scale) 9557 recwin = (long)TCP_MAXWIN << tp->rcv_scale; 9558 } 9559 9560 /* 9561 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or 9562 * <SYN,ACK>) segment itself is never scaled. The <SYN,ACK> case is 9563 * handled in syncache. 9564 */ 9565 if (flags & TH_SYN) 9566 th->th_win = htons((u_short) 9567 (min(sbspace(&so->so_rcv), TCP_MAXWIN))); 9568 else 9569 th->th_win = htons((u_short)(recwin >> tp->rcv_scale)); 9570 /* 9571 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0 9572 * window. This may cause the remote transmitter to stall. This 9573 * flag tells soreceive() to disable delayed acknowledgements when 9574 * draining the buffer. This can occur if the receiver is 9575 * attempting to read more data than can be buffered prior to 9576 * transmitting on the connection. 9577 */ 9578 if (th->th_win == 0) { 9579 tp->t_sndzerowin++; 9580 tp->t_flags |= TF_RXWIN0SENT; 9581 } else 9582 tp->t_flags &= ~TF_RXWIN0SENT; 9583 if (SEQ_GT(tp->snd_up, tp->snd_nxt)) { 9584 th->th_urp = htons((u_short)(tp->snd_up - tp->snd_nxt)); 9585 th->th_flags |= TH_URG; 9586 } else 9587 /* 9588 * If no urgent pointer to send, then we pull the urgent 9589 * pointer to the left edge of the send window so that it 9590 * doesn't drift into the send window on sequence number 9591 * wraparound. 9592 */ 9593 tp->snd_up = tp->snd_una; /* drag it along */ 9594 9595 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 9596 if (to.to_flags & TOF_SIGNATURE) { 9597 /* 9598 * Calculate MD5 signature and put it into the place 9599 * determined before. 9600 * NOTE: since TCP options buffer doesn't point into 9601 * mbuf's data, calculate offset and use it. 9602 */ 9603 if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th, 9604 (u_char *)(th + 1) + (to.to_signature - opt)) != 0) { 9605 /* 9606 * Do not send segment if the calculation of MD5 9607 * digest has failed. 9608 */ 9609 goto out; 9610 } 9611 } 9612 #endif 9613 9614 /* 9615 * Put TCP length in extended header, and then checksum extended 9616 * header and data. 9617 */ 9618 m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */ 9619 #ifdef INET6 9620 if (isipv6) { 9621 /* 9622 * ip6_plen is not need to be filled now, and will be filled 9623 * in ip6_output. 9624 */ 9625 if (tp->t_port) { 9626 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 9627 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 9628 udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 9629 th->th_sum = htons(0); 9630 UDPSTAT_INC(udps_opackets); 9631 } else { 9632 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 9633 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 9634 th->th_sum = in6_cksum_pseudo(ip6, 9635 sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP, 9636 0); 9637 } 9638 } 9639 #endif 9640 #if defined(INET6) && defined(INET) 9641 else 9642 #endif 9643 #ifdef INET 9644 { 9645 if (tp->t_port) { 9646 m->m_pkthdr.csum_flags = CSUM_UDP; 9647 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 9648 udp->uh_sum = in_pseudo(ip->ip_src.s_addr, 9649 ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP)); 9650 th->th_sum = htons(0); 9651 UDPSTAT_INC(udps_opackets); 9652 } else { 9653 m->m_pkthdr.csum_flags = CSUM_TCP; 9654 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 9655 th->th_sum = in_pseudo(ip->ip_src.s_addr, 9656 ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) + 9657 IPPROTO_TCP + len + optlen)); 9658 } 9659 /* IP version must be set here for ipv4/ipv6 checking later */ 9660 KASSERT(ip->ip_v == IPVERSION, 9661 ("%s: IP version incorrect: %d", __func__, ip->ip_v)); 9662 } 9663 #endif 9664 /* 9665 * Enable TSO and specify the size of the segments. The TCP pseudo 9666 * header checksum is always provided. XXX: Fixme: This is currently 9667 * not the case for IPv6. 9668 */ 9669 if (tso || force_tso) { 9670 KASSERT(force_tso || len > tp->t_maxseg - optlen, 9671 ("%s: len <= tso_segsz", __func__)); 9672 m->m_pkthdr.csum_flags |= CSUM_TSO; 9673 m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen; 9674 } 9675 KASSERT(len + hdrlen == m_length(m, NULL), 9676 ("%s: mbuf chain different than expected: %d + %u != %u", 9677 __func__, len, hdrlen, m_length(m, NULL))); 9678 9679 #ifdef TCP_HHOOK 9680 /* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */ 9681 hhook_run_tcp_est_out(tp, th, &to, len, tso); 9682 #endif 9683 #ifdef TCPDEBUG 9684 /* 9685 * Trace. 9686 */ 9687 if (so->so_options & SO_DEBUG) { 9688 u_short save = 0; 9689 9690 #ifdef INET6 9691 if (!isipv6) 9692 #endif 9693 { 9694 save = ipov->ih_len; 9695 ipov->ih_len = htons(m->m_pkthdr.len /* - hdrlen + 9696 * (th->th_off << 2) */ ); 9697 } 9698 tcp_trace(TA_OUTPUT, tp->t_state, tp, mtod(m, void *), th, 0); 9699 #ifdef INET6 9700 if (!isipv6) 9701 #endif 9702 ipov->ih_len = save; 9703 } 9704 #endif /* TCPDEBUG */ 9705 9706 /* We're getting ready to send; log now. */ 9707 if (tp->t_logstate != TCP_LOG_STATE_OFF) { 9708 union tcp_log_stackspecific log; 9709 struct timeval tv; 9710 9711 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 9712 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 9713 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 9714 log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt; 9715 log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs; 9716 log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs; 9717 log.u_bbr.flex4 = orig_len; 9718 if (filled_all) 9719 log.u_bbr.flex5 = 0x80000000; 9720 else 9721 log.u_bbr.flex5 = 0; 9722 if (rsm || sack_rxmit) { 9723 log.u_bbr.flex8 = 1; 9724 } else { 9725 log.u_bbr.flex8 = 0; 9726 } 9727 log.u_bbr.pkts_out = tp->t_maxseg; 9728 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 9729 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 9730 lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK, 9731 len, &log, false, NULL, NULL, 0, &tv); 9732 } else 9733 lgb = NULL; 9734 9735 /* 9736 * Fill in IP length and desired time to live and send to IP level. 9737 * There should be a better way to handle ttl and tos; we could keep 9738 * them in the template, but need a way to checksum without them. 9739 */ 9740 /* 9741 * m->m_pkthdr.len should have been set before cksum calcuration, 9742 * because in6_cksum() need it. 9743 */ 9744 #ifdef INET6 9745 if (isipv6) { 9746 /* 9747 * we separately set hoplimit for every segment, since the 9748 * user might want to change the value via setsockopt. Also, 9749 * desired default hop limit might be changed via Neighbor 9750 * Discovery. 9751 */ 9752 ip6->ip6_hlim = in6_selecthlim(inp, NULL); 9753 9754 /* 9755 * Set the packet size here for the benefit of DTrace 9756 * probes. ip6_output() will set it properly; it's supposed 9757 * to include the option header lengths as well. 9758 */ 9759 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6)); 9760 9761 if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) 9762 tp->t_flags2 |= TF2_PLPMTU_PMTUD; 9763 else 9764 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD; 9765 9766 if (tp->t_state == TCPS_SYN_SENT) 9767 TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th); 9768 9769 TCP_PROBE5(send, NULL, tp, ip6, tp, th); 9770 /* TODO: IPv6 IP6TOS_ECT bit on */ 9771 error = ip6_output(m, tp->t_inpcb->in6p_outputopts, 9772 &inp->inp_route6, 9773 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0), 9774 NULL, NULL, inp); 9775 9776 if (error == EMSGSIZE && inp->inp_route6.ro_rt != NULL) 9777 mtu = inp->inp_route6.ro_rt->rt_mtu; 9778 } 9779 #endif /* INET6 */ 9780 #if defined(INET) && defined(INET6) 9781 else 9782 #endif 9783 #ifdef INET 9784 { 9785 ip->ip_len = htons(m->m_pkthdr.len); 9786 #ifdef INET6 9787 if (inp->inp_vflag & INP_IPV6PROTO) 9788 ip->ip_ttl = in6_selecthlim(inp, NULL); 9789 #endif /* INET6 */ 9790 /* 9791 * If we do path MTU discovery, then we set DF on every 9792 * packet. This might not be the best thing to do according 9793 * to RFC3390 Section 2. However the tcp hostcache migitates 9794 * the problem so it affects only the first tcp connection 9795 * with a host. 9796 * 9797 * NB: Don't set DF on small MTU/MSS to have a safe 9798 * fallback. 9799 */ 9800 if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) { 9801 tp->t_flags2 |= TF2_PLPMTU_PMTUD; 9802 if (tp->t_port == 0 || len < V_tcp_minmss) { 9803 ip->ip_off |= htons(IP_DF); 9804 } 9805 } else { 9806 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD; 9807 } 9808 9809 if (tp->t_state == TCPS_SYN_SENT) 9810 TCP_PROBE5(connect__request, NULL, tp, ip, tp, th); 9811 9812 TCP_PROBE5(send, NULL, tp, ip, tp, th); 9813 9814 error = ip_output(m, tp->t_inpcb->inp_options, &inp->inp_route, 9815 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0), 0, 9816 inp); 9817 if (error == EMSGSIZE && inp->inp_route.ro_rt != NULL) 9818 mtu = inp->inp_route.ro_rt->rt_mtu; 9819 } 9820 #endif /* INET */ 9821 9822 out: 9823 if (lgb) { 9824 lgb->tlb_errno = error; 9825 lgb = NULL; 9826 } 9827 /* 9828 * In transmit state, time the transmission and arrange for the 9829 * retransmit. In persist state, just set snd_max. 9830 */ 9831 if (error == 0) { 9832 if (TCPS_HAVEESTABLISHED(tp->t_state) && 9833 (tp->t_flags & TF_SACK_PERMIT) && 9834 tp->rcv_numsacks > 0) 9835 tcp_clean_dsack_blocks(tp); 9836 if (len == 0) 9837 counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1); 9838 else if (len == 1) { 9839 counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1); 9840 } else if (len > 1) { 9841 int idx; 9842 9843 idx = (len / ctf_fixed_maxseg(tp)) + 3; 9844 if (idx >= TCP_MSS_ACCT_ATIMER) 9845 counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1); 9846 else 9847 counter_u64_add(rack_out_size[idx], 1); 9848 } 9849 if (hw_tls && len > 0) { 9850 if (filled_all) { 9851 counter_u64_add(rack_tls_filled, 1); 9852 rack_log_type_hrdwtso(tp, rack, len, 0, orig_len, 1); 9853 } else { 9854 if (rsm) { 9855 counter_u64_add(rack_tls_rxt, 1); 9856 rack_log_type_hrdwtso(tp, rack, len, 2, orig_len, 1); 9857 } else if (doing_tlp) { 9858 counter_u64_add(rack_tls_tlp, 1); 9859 rack_log_type_hrdwtso(tp, rack, len, 3, orig_len, 1); 9860 } else if ( (ctf_outstanding(tp) + rack->r_ctl.rc_pace_min_segs) > sbavail(sb)) { 9861 counter_u64_add(rack_tls_app, 1); 9862 rack_log_type_hrdwtso(tp, rack, len, 4, orig_len, 1); 9863 } else if ((ctf_flight_size(tp, rack->r_ctl.rc_sacked) + rack->r_ctl.rc_pace_min_segs) > tp->snd_cwnd) { 9864 counter_u64_add(rack_tls_cwnd, 1); 9865 rack_log_type_hrdwtso(tp, rack, len, 5, orig_len, 1); 9866 } else if ((ctf_outstanding(tp) + rack->r_ctl.rc_pace_min_segs) > tp->snd_wnd) { 9867 counter_u64_add(rack_tls_rwnd, 1); 9868 rack_log_type_hrdwtso(tp, rack, len, 6, orig_len, 1); 9869 } else { 9870 rack_log_type_hrdwtso(tp, rack, len, 7, orig_len, 1); 9871 counter_u64_add(rack_tls_other, 1); 9872 } 9873 } 9874 } 9875 } 9876 if (sub_from_prr && (error == 0)) { 9877 if (rack->r_ctl.rc_prr_sndcnt >= len) 9878 rack->r_ctl.rc_prr_sndcnt -= len; 9879 else 9880 rack->r_ctl.rc_prr_sndcnt = 0; 9881 } 9882 sub_from_prr = 0; 9883 rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error, cts, 9884 pass, rsm); 9885 if ((error == 0) && 9886 (len > 0) && 9887 (tp->snd_una == tp->snd_max)) 9888 rack->r_ctl.rc_tlp_rxt_last_time = cts; 9889 if ((tp->t_flags & TF_FORCEDATA) == 0 || 9890 (rack->rc_in_persist == 0)) { 9891 tcp_seq startseq = tp->snd_nxt; 9892 9893 /* 9894 * Advance snd_nxt over sequence space of this segment. 9895 */ 9896 if (error) 9897 /* We don't log or do anything with errors */ 9898 goto nomore; 9899 9900 if (flags & (TH_SYN | TH_FIN)) { 9901 if (flags & TH_SYN) 9902 tp->snd_nxt++; 9903 if (flags & TH_FIN) { 9904 tp->snd_nxt++; 9905 tp->t_flags |= TF_SENTFIN; 9906 } 9907 } 9908 /* In the ENOBUFS case we do *not* update snd_max */ 9909 if (sack_rxmit) 9910 goto nomore; 9911 9912 tp->snd_nxt += len; 9913 if (SEQ_GT(tp->snd_nxt, tp->snd_max)) { 9914 if (tp->snd_una == tp->snd_max) { 9915 /* 9916 * Update the time we just added data since 9917 * none was outstanding. 9918 */ 9919 rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__); 9920 tp->t_acktime = ticks; 9921 } 9922 tp->snd_max = tp->snd_nxt; 9923 /* 9924 * Time this transmission if not a retransmission and 9925 * not currently timing anything. 9926 * This is only relevant in case of switching back to 9927 * the base stack. 9928 */ 9929 if (tp->t_rtttime == 0) { 9930 tp->t_rtttime = ticks; 9931 tp->t_rtseq = startseq; 9932 TCPSTAT_INC(tcps_segstimed); 9933 } 9934 #ifdef STATS 9935 if (!(tp->t_flags & TF_GPUTINPROG) && len) { 9936 tp->t_flags |= TF_GPUTINPROG; 9937 tp->gput_seq = startseq; 9938 tp->gput_ack = startseq + 9939 ulmin(sbavail(sb) - sb_offset, sendwin); 9940 tp->gput_ts = tcp_ts_getticks(); 9941 } 9942 #endif 9943 } 9944 } else { 9945 /* 9946 * Persist case, update snd_max but since we are in persist 9947 * mode (no window) we do not update snd_nxt. 9948 */ 9949 int32_t xlen = len; 9950 9951 if (error) 9952 goto nomore; 9953 9954 if (flags & TH_SYN) 9955 ++xlen; 9956 if (flags & TH_FIN) { 9957 ++xlen; 9958 tp->t_flags |= TF_SENTFIN; 9959 } 9960 /* In the ENOBUFS case we do *not* update snd_max */ 9961 if (SEQ_GT(tp->snd_nxt + xlen, tp->snd_max)) { 9962 if (tp->snd_una == tp->snd_max) { 9963 /* 9964 * Update the time we just added data since 9965 * none was outstanding. 9966 */ 9967 rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__); 9968 tp->t_acktime = ticks; 9969 } 9970 tp->snd_max = tp->snd_nxt + len; 9971 } 9972 } 9973 nomore: 9974 if (error) { 9975 SOCKBUF_UNLOCK_ASSERT(sb); /* Check gotos. */ 9976 /* 9977 * Failures do not advance the seq counter above. For the 9978 * case of ENOBUFS we will fall out and retry in 1ms with 9979 * the hpts. Everything else will just have to retransmit 9980 * with the timer. 9981 * 9982 * In any case, we do not want to loop around for another 9983 * send without a good reason. 9984 */ 9985 sendalot = 0; 9986 switch (error) { 9987 case EPERM: 9988 tp->t_flags &= ~TF_FORCEDATA; 9989 tp->t_softerror = error; 9990 return (error); 9991 case ENOBUFS: 9992 if (slot == 0) { 9993 /* 9994 * Pace us right away to retry in a some 9995 * time 9996 */ 9997 slot = 1 + rack->rc_enobuf; 9998 if (rack->rc_enobuf < 255) 9999 rack->rc_enobuf++; 10000 if (slot > (rack->rc_rack_rtt / 2)) { 10001 slot = rack->rc_rack_rtt / 2; 10002 } 10003 if (slot < 10) 10004 slot = 10; 10005 } 10006 counter_u64_add(rack_saw_enobuf, 1); 10007 error = 0; 10008 goto enobufs; 10009 case EMSGSIZE: 10010 /* 10011 * For some reason the interface we used initially 10012 * to send segments changed to another or lowered 10013 * its MTU. If TSO was active we either got an 10014 * interface without TSO capabilits or TSO was 10015 * turned off. If we obtained mtu from ip_output() 10016 * then update it and try again. 10017 */ 10018 if (tso) 10019 tp->t_flags &= ~TF_TSO; 10020 if (mtu != 0) { 10021 tcp_mss_update(tp, -1, mtu, NULL, NULL); 10022 goto again; 10023 } 10024 slot = 10; 10025 rack_start_hpts_timer(rack, tp, cts, slot, 0, 0); 10026 tp->t_flags &= ~TF_FORCEDATA; 10027 return (error); 10028 case ENETUNREACH: 10029 counter_u64_add(rack_saw_enetunreach, 1); 10030 case EHOSTDOWN: 10031 case EHOSTUNREACH: 10032 case ENETDOWN: 10033 if (TCPS_HAVERCVDSYN(tp->t_state)) { 10034 tp->t_softerror = error; 10035 } 10036 /* FALLTHROUGH */ 10037 default: 10038 slot = 10; 10039 rack_start_hpts_timer(rack, tp, cts, slot, 0, 0); 10040 tp->t_flags &= ~TF_FORCEDATA; 10041 return (error); 10042 } 10043 } else { 10044 rack->rc_enobuf = 0; 10045 } 10046 TCPSTAT_INC(tcps_sndtotal); 10047 10048 /* 10049 * Data sent (as far as we can tell). If this advertises a larger 10050 * window than any other segment, then remember the size of the 10051 * advertised window. Any pending ACK has now been sent. 10052 */ 10053 if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv)) 10054 tp->rcv_adv = tp->rcv_nxt + recwin; 10055 tp->last_ack_sent = tp->rcv_nxt; 10056 tp->t_flags &= ~(TF_ACKNOW | TF_DELACK); 10057 enobufs: 10058 rack->r_tlp_running = 0; 10059 if (flags & TH_RST) { 10060 /* 10061 * We don't send again after sending a RST. 10062 */ 10063 slot = 0; 10064 sendalot = 0; 10065 } 10066 if (rsm && (slot == 0)) { 10067 /* 10068 * Dup ack retransmission possibly, so 10069 * lets assure we have at least min rack 10070 * time, if its a rack resend then the rack 10071 * to will also be set to this. 10072 */ 10073 slot = rack->r_ctl.rc_min_to; 10074 } 10075 if (slot) { 10076 /* set the rack tcb into the slot N */ 10077 counter_u64_add(rack_paced_segments, 1); 10078 } else if (sendalot) { 10079 if (len) 10080 counter_u64_add(rack_unpaced_segments, 1); 10081 sack_rxmit = 0; 10082 tp->t_flags &= ~TF_FORCEDATA; 10083 goto again; 10084 } else if (len) { 10085 counter_u64_add(rack_unpaced_segments, 1); 10086 } 10087 tp->t_flags &= ~TF_FORCEDATA; 10088 rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0); 10089 return (error); 10090 } 10091 10092 /* 10093 * rack_ctloutput() must drop the inpcb lock before performing copyin on 10094 * socket option arguments. When it re-acquires the lock after the copy, it 10095 * has to revalidate that the connection is still valid for the socket 10096 * option. 10097 */ 10098 static int 10099 rack_set_sockopt(struct socket *so, struct sockopt *sopt, 10100 struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack) 10101 { 10102 struct epoch_tracker et; 10103 int32_t error = 0, optval; 10104 10105 switch (sopt->sopt_name) { 10106 case TCP_RACK_PROP_RATE: 10107 case TCP_RACK_PROP: 10108 case TCP_RACK_TLP_REDUCE: 10109 case TCP_RACK_EARLY_RECOV: 10110 case TCP_RACK_PACE_ALWAYS: 10111 case TCP_DELACK: 10112 case TCP_RACK_PACE_REDUCE: 10113 case TCP_RACK_PACE_MAX_SEG: 10114 case TCP_RACK_PRR_SENDALOT: 10115 case TCP_RACK_MIN_TO: 10116 case TCP_RACK_EARLY_SEG: 10117 case TCP_RACK_REORD_THRESH: 10118 case TCP_RACK_REORD_FADE: 10119 case TCP_RACK_TLP_THRESH: 10120 case TCP_RACK_PKT_DELAY: 10121 case TCP_RACK_TLP_USE: 10122 case TCP_RACK_TLP_INC_VAR: 10123 case TCP_RACK_IDLE_REDUCE_HIGH: 10124 case TCP_RACK_MIN_PACE: 10125 case TCP_RACK_GP_INCREASE: 10126 case TCP_BBR_RACK_RTT_USE: 10127 case TCP_BBR_USE_RACK_CHEAT: 10128 case TCP_RACK_DO_DETECTION: 10129 case TCP_DATA_AFTER_CLOSE: 10130 break; 10131 default: 10132 return (tcp_default_ctloutput(so, sopt, inp, tp)); 10133 break; 10134 } 10135 INP_WUNLOCK(inp); 10136 error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval)); 10137 if (error) 10138 return (error); 10139 INP_WLOCK(inp); 10140 if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) { 10141 INP_WUNLOCK(inp); 10142 return (ECONNRESET); 10143 } 10144 tp = intotcpcb(inp); 10145 rack = (struct tcp_rack *)tp->t_fb_ptr; 10146 switch (sopt->sopt_name) { 10147 case TCP_RACK_DO_DETECTION: 10148 RACK_OPTS_INC(tcp_rack_do_detection); 10149 if (optval == 0) 10150 rack->do_detection = 0; 10151 else 10152 rack->do_detection = 1; 10153 break; 10154 case TCP_RACK_PROP_RATE: 10155 if ((optval <= 0) || (optval >= 100)) { 10156 error = EINVAL; 10157 break; 10158 } 10159 RACK_OPTS_INC(tcp_rack_prop_rate); 10160 rack->r_ctl.rc_prop_rate = optval; 10161 break; 10162 case TCP_RACK_TLP_USE: 10163 if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) { 10164 error = EINVAL; 10165 break; 10166 } 10167 RACK_OPTS_INC(tcp_tlp_use); 10168 rack->rack_tlp_threshold_use = optval; 10169 break; 10170 case TCP_RACK_PROP: 10171 /* RACK proportional rate reduction (bool) */ 10172 RACK_OPTS_INC(tcp_rack_prop); 10173 rack->r_ctl.rc_prop_reduce = optval; 10174 break; 10175 case TCP_RACK_TLP_REDUCE: 10176 /* RACK TLP cwnd reduction (bool) */ 10177 RACK_OPTS_INC(tcp_rack_tlp_reduce); 10178 rack->r_ctl.rc_tlp_cwnd_reduce = optval; 10179 break; 10180 case TCP_RACK_EARLY_RECOV: 10181 /* Should recovery happen early (bool) */ 10182 RACK_OPTS_INC(tcp_rack_early_recov); 10183 rack->r_ctl.rc_early_recovery = optval; 10184 break; 10185 case TCP_RACK_PACE_ALWAYS: 10186 /* Use the always pace method (bool) */ 10187 RACK_OPTS_INC(tcp_rack_pace_always); 10188 if (optval > 0) 10189 rack->rc_always_pace = 1; 10190 else 10191 rack->rc_always_pace = 0; 10192 break; 10193 case TCP_RACK_PACE_REDUCE: 10194 /* RACK Hptsi reduction factor (divisor) */ 10195 RACK_OPTS_INC(tcp_rack_pace_reduce); 10196 if (optval) 10197 /* Must be non-zero */ 10198 rack->rc_pace_reduce = optval; 10199 else 10200 error = EINVAL; 10201 break; 10202 case TCP_RACK_PACE_MAX_SEG: 10203 /* Max segments in a pace */ 10204 RACK_OPTS_INC(tcp_rack_max_seg); 10205 rack->rc_pace_max_segs = optval; 10206 rack_set_pace_segments(tp, rack); 10207 break; 10208 case TCP_RACK_PRR_SENDALOT: 10209 /* Allow PRR to send more than one seg */ 10210 RACK_OPTS_INC(tcp_rack_prr_sendalot); 10211 rack->r_ctl.rc_prr_sendalot = optval; 10212 break; 10213 case TCP_RACK_MIN_TO: 10214 /* Minimum time between rack t-o's in ms */ 10215 RACK_OPTS_INC(tcp_rack_min_to); 10216 rack->r_ctl.rc_min_to = optval; 10217 break; 10218 case TCP_RACK_EARLY_SEG: 10219 /* If early recovery max segments */ 10220 RACK_OPTS_INC(tcp_rack_early_seg); 10221 rack->r_ctl.rc_early_recovery_segs = optval; 10222 break; 10223 case TCP_RACK_REORD_THRESH: 10224 /* RACK reorder threshold (shift amount) */ 10225 RACK_OPTS_INC(tcp_rack_reord_thresh); 10226 if ((optval > 0) && (optval < 31)) 10227 rack->r_ctl.rc_reorder_shift = optval; 10228 else 10229 error = EINVAL; 10230 break; 10231 case TCP_RACK_REORD_FADE: 10232 /* Does reordering fade after ms time */ 10233 RACK_OPTS_INC(tcp_rack_reord_fade); 10234 rack->r_ctl.rc_reorder_fade = optval; 10235 break; 10236 case TCP_RACK_TLP_THRESH: 10237 /* RACK TLP theshold i.e. srtt+(srtt/N) */ 10238 RACK_OPTS_INC(tcp_rack_tlp_thresh); 10239 if (optval) 10240 rack->r_ctl.rc_tlp_threshold = optval; 10241 else 10242 error = EINVAL; 10243 break; 10244 case TCP_BBR_USE_RACK_CHEAT: 10245 RACK_OPTS_INC(tcp_rack_cheat); 10246 if (optval) 10247 rack->use_rack_cheat = 1; 10248 else 10249 rack->use_rack_cheat = 0; 10250 break; 10251 case TCP_RACK_PKT_DELAY: 10252 /* RACK added ms i.e. rack-rtt + reord + N */ 10253 RACK_OPTS_INC(tcp_rack_pkt_delay); 10254 rack->r_ctl.rc_pkt_delay = optval; 10255 break; 10256 case TCP_RACK_TLP_INC_VAR: 10257 /* Does TLP include rtt variance in t-o */ 10258 error = EINVAL; 10259 break; 10260 case TCP_RACK_IDLE_REDUCE_HIGH: 10261 error = EINVAL; 10262 break; 10263 case TCP_DELACK: 10264 if (optval == 0) 10265 tp->t_delayed_ack = 0; 10266 else 10267 tp->t_delayed_ack = 1; 10268 if (tp->t_flags & TF_DELACK) { 10269 tp->t_flags &= ~TF_DELACK; 10270 tp->t_flags |= TF_ACKNOW; 10271 NET_EPOCH_ENTER(et); 10272 rack_output(tp); 10273 NET_EPOCH_EXIT(et); 10274 } 10275 break; 10276 case TCP_RACK_MIN_PACE: 10277 RACK_OPTS_INC(tcp_rack_min_pace); 10278 if (optval > 3) 10279 rack->r_enforce_min_pace = 3; 10280 else 10281 rack->r_enforce_min_pace = optval; 10282 break; 10283 case TCP_RACK_GP_INCREASE: 10284 if ((optval >= 0) && 10285 (optval <= 256)) 10286 rack->rack_per_of_gp = optval; 10287 else 10288 error = EINVAL; 10289 10290 break; 10291 case TCP_BBR_RACK_RTT_USE: 10292 if ((optval != USE_RTT_HIGH) && 10293 (optval != USE_RTT_LOW) && 10294 (optval != USE_RTT_AVG)) 10295 error = EINVAL; 10296 else 10297 rack->r_ctl.rc_rate_sample_method = optval; 10298 break; 10299 case TCP_DATA_AFTER_CLOSE: 10300 if (optval) 10301 rack->rc_allow_data_af_clo = 1; 10302 else 10303 rack->rc_allow_data_af_clo = 0; 10304 break; 10305 default: 10306 return (tcp_default_ctloutput(so, sopt, inp, tp)); 10307 break; 10308 } 10309 #ifdef NETFLIX_STATS 10310 tcp_log_socket_option(tp, sopt->sopt_name, optval, error); 10311 #endif 10312 INP_WUNLOCK(inp); 10313 return (error); 10314 } 10315 10316 static int 10317 rack_get_sockopt(struct socket *so, struct sockopt *sopt, 10318 struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack) 10319 { 10320 int32_t error, optval; 10321 10322 /* 10323 * Because all our options are either boolean or an int, we can just 10324 * pull everything into optval and then unlock and copy. If we ever 10325 * add a option that is not a int, then this will have quite an 10326 * impact to this routine. 10327 */ 10328 error = 0; 10329 switch (sopt->sopt_name) { 10330 case TCP_RACK_DO_DETECTION: 10331 optval = rack->do_detection; 10332 break; 10333 10334 case TCP_RACK_PROP_RATE: 10335 optval = rack->r_ctl.rc_prop_rate; 10336 break; 10337 case TCP_RACK_PROP: 10338 /* RACK proportional rate reduction (bool) */ 10339 optval = rack->r_ctl.rc_prop_reduce; 10340 break; 10341 case TCP_RACK_TLP_REDUCE: 10342 /* RACK TLP cwnd reduction (bool) */ 10343 optval = rack->r_ctl.rc_tlp_cwnd_reduce; 10344 break; 10345 case TCP_RACK_EARLY_RECOV: 10346 /* Should recovery happen early (bool) */ 10347 optval = rack->r_ctl.rc_early_recovery; 10348 break; 10349 case TCP_RACK_PACE_REDUCE: 10350 /* RACK Hptsi reduction factor (divisor) */ 10351 optval = rack->rc_pace_reduce; 10352 break; 10353 case TCP_RACK_PACE_MAX_SEG: 10354 /* Max segments in a pace */ 10355 optval = rack->rc_pace_max_segs; 10356 break; 10357 case TCP_RACK_PACE_ALWAYS: 10358 /* Use the always pace method */ 10359 optval = rack->rc_always_pace; 10360 break; 10361 case TCP_RACK_PRR_SENDALOT: 10362 /* Allow PRR to send more than one seg */ 10363 optval = rack->r_ctl.rc_prr_sendalot; 10364 break; 10365 case TCP_RACK_MIN_TO: 10366 /* Minimum time between rack t-o's in ms */ 10367 optval = rack->r_ctl.rc_min_to; 10368 break; 10369 case TCP_RACK_EARLY_SEG: 10370 /* If early recovery max segments */ 10371 optval = rack->r_ctl.rc_early_recovery_segs; 10372 break; 10373 case TCP_RACK_REORD_THRESH: 10374 /* RACK reorder threshold (shift amount) */ 10375 optval = rack->r_ctl.rc_reorder_shift; 10376 break; 10377 case TCP_RACK_REORD_FADE: 10378 /* Does reordering fade after ms time */ 10379 optval = rack->r_ctl.rc_reorder_fade; 10380 break; 10381 case TCP_BBR_USE_RACK_CHEAT: 10382 /* Do we use the rack cheat for rxt */ 10383 optval = rack->use_rack_cheat; 10384 break; 10385 case TCP_RACK_TLP_THRESH: 10386 /* RACK TLP theshold i.e. srtt+(srtt/N) */ 10387 optval = rack->r_ctl.rc_tlp_threshold; 10388 break; 10389 case TCP_RACK_PKT_DELAY: 10390 /* RACK added ms i.e. rack-rtt + reord + N */ 10391 optval = rack->r_ctl.rc_pkt_delay; 10392 break; 10393 case TCP_RACK_TLP_USE: 10394 optval = rack->rack_tlp_threshold_use; 10395 break; 10396 case TCP_RACK_TLP_INC_VAR: 10397 /* Does TLP include rtt variance in t-o */ 10398 error = EINVAL; 10399 break; 10400 case TCP_RACK_IDLE_REDUCE_HIGH: 10401 error = EINVAL; 10402 break; 10403 case TCP_RACK_MIN_PACE: 10404 optval = rack->r_enforce_min_pace; 10405 break; 10406 case TCP_RACK_GP_INCREASE: 10407 optval = rack->rack_per_of_gp; 10408 break; 10409 case TCP_BBR_RACK_RTT_USE: 10410 optval = rack->r_ctl.rc_rate_sample_method; 10411 break; 10412 case TCP_DELACK: 10413 optval = tp->t_delayed_ack; 10414 break; 10415 case TCP_DATA_AFTER_CLOSE: 10416 optval = rack->rc_allow_data_af_clo; 10417 break; 10418 default: 10419 return (tcp_default_ctloutput(so, sopt, inp, tp)); 10420 break; 10421 } 10422 INP_WUNLOCK(inp); 10423 if (error == 0) { 10424 error = sooptcopyout(sopt, &optval, sizeof optval); 10425 } 10426 return (error); 10427 } 10428 10429 static int 10430 rack_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp) 10431 { 10432 int32_t error = EINVAL; 10433 struct tcp_rack *rack; 10434 10435 rack = (struct tcp_rack *)tp->t_fb_ptr; 10436 if (rack == NULL) { 10437 /* Huh? */ 10438 goto out; 10439 } 10440 if (sopt->sopt_dir == SOPT_SET) { 10441 return (rack_set_sockopt(so, sopt, inp, tp, rack)); 10442 } else if (sopt->sopt_dir == SOPT_GET) { 10443 return (rack_get_sockopt(so, sopt, inp, tp, rack)); 10444 } 10445 out: 10446 INP_WUNLOCK(inp); 10447 return (error); 10448 } 10449 10450 10451 static struct tcp_function_block __tcp_rack = { 10452 .tfb_tcp_block_name = __XSTRING(STACKNAME), 10453 .tfb_tcp_output = rack_output, 10454 .tfb_do_queued_segments = ctf_do_queued_segments, 10455 .tfb_do_segment_nounlock = rack_do_segment_nounlock, 10456 .tfb_tcp_do_segment = rack_do_segment, 10457 .tfb_tcp_ctloutput = rack_ctloutput, 10458 .tfb_tcp_fb_init = rack_init, 10459 .tfb_tcp_fb_fini = rack_fini, 10460 .tfb_tcp_timer_stop_all = rack_stopall, 10461 .tfb_tcp_timer_activate = rack_timer_activate, 10462 .tfb_tcp_timer_active = rack_timer_active, 10463 .tfb_tcp_timer_stop = rack_timer_stop, 10464 .tfb_tcp_rexmit_tmr = rack_remxt_tmr, 10465 .tfb_tcp_handoff_ok = rack_handoff_ok 10466 }; 10467 10468 static const char *rack_stack_names[] = { 10469 __XSTRING(STACKNAME), 10470 #ifdef STACKALIAS 10471 __XSTRING(STACKALIAS), 10472 #endif 10473 }; 10474 10475 static int 10476 rack_ctor(void *mem, int32_t size, void *arg, int32_t how) 10477 { 10478 memset(mem, 0, size); 10479 return (0); 10480 } 10481 10482 static void 10483 rack_dtor(void *mem, int32_t size, void *arg) 10484 { 10485 10486 } 10487 10488 static bool rack_mod_inited = false; 10489 10490 static int 10491 tcp_addrack(module_t mod, int32_t type, void *data) 10492 { 10493 int32_t err = 0; 10494 int num_stacks; 10495 10496 switch (type) { 10497 case MOD_LOAD: 10498 rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map", 10499 sizeof(struct rack_sendmap), 10500 rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0); 10501 10502 rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb", 10503 sizeof(struct tcp_rack), 10504 rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0); 10505 10506 sysctl_ctx_init(&rack_sysctl_ctx); 10507 rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx, 10508 SYSCTL_STATIC_CHILDREN(_net_inet_tcp), 10509 OID_AUTO, 10510 #ifdef STACKALIAS 10511 __XSTRING(STACKALIAS), 10512 #else 10513 __XSTRING(STACKNAME), 10514 #endif 10515 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 10516 ""); 10517 if (rack_sysctl_root == NULL) { 10518 printf("Failed to add sysctl node\n"); 10519 err = EFAULT; 10520 goto free_uma; 10521 } 10522 rack_init_sysctls(); 10523 num_stacks = nitems(rack_stack_names); 10524 err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK, 10525 rack_stack_names, &num_stacks); 10526 if (err) { 10527 printf("Failed to register %s stack name for " 10528 "%s module\n", rack_stack_names[num_stacks], 10529 __XSTRING(MODNAME)); 10530 sysctl_ctx_free(&rack_sysctl_ctx); 10531 free_uma: 10532 uma_zdestroy(rack_zone); 10533 uma_zdestroy(rack_pcb_zone); 10534 rack_counter_destroy(); 10535 printf("Failed to register rack module -- err:%d\n", err); 10536 return (err); 10537 } 10538 tcp_lro_reg_mbufq(); 10539 rack_mod_inited = true; 10540 break; 10541 case MOD_QUIESCE: 10542 err = deregister_tcp_functions(&__tcp_rack, true, false); 10543 break; 10544 case MOD_UNLOAD: 10545 err = deregister_tcp_functions(&__tcp_rack, false, true); 10546 if (err == EBUSY) 10547 break; 10548 if (rack_mod_inited) { 10549 uma_zdestroy(rack_zone); 10550 uma_zdestroy(rack_pcb_zone); 10551 sysctl_ctx_free(&rack_sysctl_ctx); 10552 rack_counter_destroy(); 10553 rack_mod_inited = false; 10554 } 10555 tcp_lro_dereg_mbufq(); 10556 err = 0; 10557 break; 10558 default: 10559 return (EOPNOTSUPP); 10560 } 10561 return (err); 10562 } 10563 10564 static moduledata_t tcp_rack = { 10565 .name = __XSTRING(MODNAME), 10566 .evhand = tcp_addrack, 10567 .priv = 0 10568 }; 10569 10570 MODULE_VERSION(MODNAME, 1); 10571 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 10572 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1); 10573