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