1 /*- 2 * Copyright (c) 2016-9 Netflix, Inc. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 * 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_inet.h" 31 #include "opt_inet6.h" 32 #include "opt_ipsec.h" 33 #include "opt_tcpdebug.h" 34 #include "opt_ratelimit.h" 35 #include "opt_kern_tls.h" 36 #include <sys/param.h> 37 #include <sys/arb.h> 38 #include <sys/module.h> 39 #include <sys/kernel.h> 40 #ifdef TCP_HHOOK 41 #include <sys/hhook.h> 42 #endif 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/lock.h> 46 #include <sys/mutex.h> 47 #include <sys/mbuf.h> 48 #include <sys/proc.h> /* for proc0 declaration */ 49 #include <sys/socket.h> 50 #include <sys/socketvar.h> 51 #ifdef KERN_TLS 52 #include <sys/ktls.h> 53 #endif 54 #include <sys/sysctl.h> 55 #include <sys/systm.h> 56 #ifdef STATS 57 #include <sys/qmath.h> 58 #include <sys/tree.h> 59 #include <sys/stats.h> /* Must come after qmath.h and tree.h */ 60 #endif 61 #include <sys/refcount.h> 62 #include <sys/tree.h> 63 #include <sys/queue.h> 64 #include <sys/smp.h> 65 #include <sys/kthread.h> 66 #include <sys/kern_prefetch.h> 67 68 #include <vm/uma.h> 69 70 #include <net/route.h> 71 #include <net/vnet.h> 72 73 #define TCPSTATES /* for logging */ 74 75 #include <netinet/in.h> 76 #include <netinet/in_kdtrace.h> 77 #include <netinet/in_pcb.h> 78 #include <netinet/ip.h> 79 #include <netinet/ip_icmp.h> /* required for icmp_var.h */ 80 #include <netinet/icmp_var.h> /* for ICMP_BANDLIM */ 81 #include <netinet/ip_var.h> 82 #include <netinet/ip6.h> 83 #include <netinet6/in6_pcb.h> 84 #include <netinet6/ip6_var.h> 85 #include <netinet/tcp.h> 86 #define TCPOUTFLAGS 87 #include <netinet/tcp_fsm.h> 88 #include <netinet/tcp_log_buf.h> 89 #include <netinet/tcp_seq.h> 90 #include <netinet/tcp_timer.h> 91 #include <netinet/tcp_var.h> 92 #include <netinet/tcp_hpts.h> 93 #include <netinet/tcpip.h> 94 #include <netinet/cc/cc.h> 95 #include <netinet/tcp_fastopen.h> 96 #include <netinet/tcp_lro.h> 97 #ifdef TCPDEBUG 98 #include <netinet/tcp_debug.h> 99 #endif /* TCPDEBUG */ 100 #ifdef TCP_OFFLOAD 101 #include <netinet/tcp_offload.h> 102 #endif 103 #ifdef INET6 104 #include <netinet6/tcp6_var.h> 105 #endif 106 107 #include <netipsec/ipsec_support.h> 108 109 #if defined(IPSEC) || defined(IPSEC_SUPPORT) 110 #include <netipsec/ipsec.h> 111 #include <netipsec/ipsec6.h> 112 #endif /* IPSEC */ 113 114 #include <netinet/udp.h> 115 #include <netinet/udp_var.h> 116 #include <machine/in_cksum.h> 117 118 #ifdef MAC 119 #include <security/mac/mac_framework.h> 120 #endif 121 #include "sack_filter.h" 122 #include "tcp_rack.h" 123 #include "rack_bbr_common.h" 124 125 uma_zone_t rack_zone; 126 uma_zone_t rack_pcb_zone; 127 128 #ifndef TICKS2SBT 129 #define TICKS2SBT(__t) (tick_sbt * ((sbintime_t)(__t))) 130 #endif 131 132 struct sysctl_ctx_list rack_sysctl_ctx; 133 struct sysctl_oid *rack_sysctl_root; 134 135 #define CUM_ACKED 1 136 #define SACKED 2 137 138 /* 139 * The RACK module incorporates a number of 140 * TCP ideas that have been put out into the IETF 141 * over the last few years: 142 * - Matt Mathis's Rate Halving which slowly drops 143 * the congestion window so that the ack clock can 144 * be maintained during a recovery. 145 * - Yuchung Cheng's RACK TCP (for which its named) that 146 * will stop us using the number of dup acks and instead 147 * use time as the gage of when we retransmit. 148 * - Reorder Detection of RFC4737 and the Tail-Loss probe draft 149 * of Dukkipati et.al. 150 * RACK depends on SACK, so if an endpoint arrives that 151 * cannot do SACK the state machine below will shuttle the 152 * connection back to using the "default" TCP stack that is 153 * in FreeBSD. 154 * 155 * To implement RACK the original TCP stack was first decomposed 156 * into a functional state machine with individual states 157 * for each of the possible TCP connection states. The do_segement 158 * functions role in life is to mandate the connection supports SACK 159 * initially and then assure that the RACK state matches the conenction 160 * state before calling the states do_segment function. Each 161 * state is simplified due to the fact that the original do_segment 162 * has been decomposed and we *know* what state we are in (no 163 * switches on the state) and all tests for SACK are gone. This 164 * greatly simplifies what each state does. 165 * 166 * TCP output is also over-written with a new version since it 167 * must maintain the new rack scoreboard. 168 * 169 */ 170 static int32_t rack_tlp_thresh = 1; 171 static int32_t rack_reorder_thresh = 2; 172 static int32_t rack_reorder_fade = 60000; /* 0 - never fade, def 60,000 173 * - 60 seconds */ 174 /* Attack threshold detections */ 175 static uint32_t rack_highest_sack_thresh_seen = 0; 176 static uint32_t rack_highest_move_thresh_seen = 0; 177 178 static int32_t rack_pkt_delay = 1; 179 static int32_t rack_min_pace_time = 0; 180 static int32_t rack_early_recovery = 1; 181 static int32_t rack_send_a_lot_in_prr = 1; 182 static int32_t rack_min_to = 1; /* Number of ms minimum timeout */ 183 static int32_t rack_verbose_logging = 0; 184 static int32_t rack_ignore_data_after_close = 1; 185 static int32_t use_rack_cheat = 1; 186 static int32_t rack_persist_min = 250; /* 250ms */ 187 static int32_t rack_persist_max = 1000; /* 1 Second */ 188 static int32_t rack_sack_not_required = 0; /* set to one to allow non-sack to use rack */ 189 static int32_t rack_hw_tls_max_seg = 0; /* 0 means use hw-tls single segment */ 190 191 /* 192 * Currently regular tcp has a rto_min of 30ms 193 * the backoff goes 12 times so that ends up 194 * being a total of 122.850 seconds before a 195 * connection is killed. 196 */ 197 static int32_t rack_tlp_min = 10; 198 static int32_t rack_rto_min = 30; /* 30ms same as main freebsd */ 199 static int32_t rack_rto_max = 4000; /* 4 seconds */ 200 static const int32_t rack_free_cache = 2; 201 static int32_t rack_hptsi_segments = 40; 202 static int32_t rack_rate_sample_method = USE_RTT_LOW; 203 static int32_t rack_pace_every_seg = 0; 204 static int32_t rack_delayed_ack_time = 200; /* 200ms */ 205 static int32_t rack_slot_reduction = 4; 206 static int32_t rack_lower_cwnd_at_tlp = 0; 207 static int32_t rack_use_proportional_reduce = 0; 208 static int32_t rack_proportional_rate = 10; 209 static int32_t rack_tlp_max_resend = 2; 210 static int32_t rack_limited_retran = 0; 211 static int32_t rack_always_send_oldest = 0; 212 static int32_t rack_use_sack_filter = 1; 213 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE; 214 static int32_t rack_per_of_gp = 50; 215 216 /* Rack specific counters */ 217 counter_u64_t rack_badfr; 218 counter_u64_t rack_badfr_bytes; 219 counter_u64_t rack_rtm_prr_retran; 220 counter_u64_t rack_rtm_prr_newdata; 221 counter_u64_t rack_timestamp_mismatch; 222 counter_u64_t rack_reorder_seen; 223 counter_u64_t rack_paced_segments; 224 counter_u64_t rack_unpaced_segments; 225 counter_u64_t rack_calc_zero; 226 counter_u64_t rack_calc_nonzero; 227 counter_u64_t rack_saw_enobuf; 228 counter_u64_t rack_saw_enetunreach; 229 counter_u64_t rack_per_timer_hole; 230 231 /* Tail loss probe counters */ 232 counter_u64_t rack_tlp_tot; 233 counter_u64_t rack_tlp_newdata; 234 counter_u64_t rack_tlp_retran; 235 counter_u64_t rack_tlp_retran_bytes; 236 counter_u64_t rack_tlp_retran_fail; 237 counter_u64_t rack_to_tot; 238 counter_u64_t rack_to_arm_rack; 239 counter_u64_t rack_to_arm_tlp; 240 counter_u64_t rack_to_alloc; 241 counter_u64_t rack_to_alloc_hard; 242 counter_u64_t rack_to_alloc_emerg; 243 counter_u64_t rack_to_alloc_limited; 244 counter_u64_t rack_alloc_limited_conns; 245 counter_u64_t rack_split_limited; 246 247 counter_u64_t rack_sack_proc_all; 248 counter_u64_t rack_sack_proc_short; 249 counter_u64_t rack_sack_proc_restart; 250 counter_u64_t rack_sack_attacks_detected; 251 counter_u64_t rack_sack_attacks_reversed; 252 counter_u64_t rack_sack_used_next_merge; 253 counter_u64_t rack_sack_splits; 254 counter_u64_t rack_sack_used_prev_merge; 255 counter_u64_t rack_sack_skipped_acked; 256 counter_u64_t rack_ack_total; 257 counter_u64_t rack_express_sack; 258 counter_u64_t rack_sack_total; 259 counter_u64_t rack_move_none; 260 counter_u64_t rack_move_some; 261 262 counter_u64_t rack_used_tlpmethod; 263 counter_u64_t rack_used_tlpmethod2; 264 counter_u64_t rack_enter_tlp_calc; 265 counter_u64_t rack_input_idle_reduces; 266 counter_u64_t rack_collapsed_win; 267 counter_u64_t rack_tlp_does_nada; 268 269 /* Counters for HW TLS */ 270 counter_u64_t rack_tls_rwnd; 271 counter_u64_t rack_tls_cwnd; 272 counter_u64_t rack_tls_app; 273 counter_u64_t rack_tls_other; 274 counter_u64_t rack_tls_filled; 275 counter_u64_t rack_tls_rxt; 276 counter_u64_t rack_tls_tlp; 277 278 /* Temp CPU counters */ 279 counter_u64_t rack_find_high; 280 281 counter_u64_t rack_progress_drops; 282 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE]; 283 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE]; 284 285 static void 286 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick, int event, int line); 287 288 static int 289 rack_process_ack(struct mbuf *m, struct tcphdr *th, 290 struct socket *so, struct tcpcb *tp, struct tcpopt *to, 291 uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val); 292 static int 293 rack_process_data(struct mbuf *m, struct tcphdr *th, 294 struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, 295 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt); 296 static void 297 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, 298 struct tcphdr *th, uint16_t nsegs, uint16_t type, int32_t recovery); 299 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack); 300 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack, 301 uint8_t limit_type); 302 static struct rack_sendmap * 303 rack_check_recovery_mode(struct tcpcb *tp, 304 uint32_t tsused); 305 static void 306 rack_cong_signal(struct tcpcb *tp, struct tcphdr *th, 307 uint32_t type); 308 static void rack_counter_destroy(void); 309 static int 310 rack_ctloutput(struct socket *so, struct sockopt *sopt, 311 struct inpcb *inp, struct tcpcb *tp); 312 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how); 313 static void 314 rack_do_segment(struct mbuf *m, struct tcphdr *th, 315 struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, 316 uint8_t iptos); 317 static void rack_dtor(void *mem, int32_t size, void *arg); 318 static void 319 rack_earlier_retran(struct tcpcb *tp, struct rack_sendmap *rsm, 320 uint32_t t, uint32_t cts); 321 static struct rack_sendmap * 322 rack_find_high_nonack(struct tcp_rack *rack, 323 struct rack_sendmap *rsm); 324 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack); 325 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm); 326 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged); 327 static int 328 rack_get_sockopt(struct socket *so, struct sockopt *sopt, 329 struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack); 330 static int32_t rack_handoff_ok(struct tcpcb *tp); 331 static int32_t rack_init(struct tcpcb *tp); 332 static void rack_init_sysctls(void); 333 static void 334 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, 335 struct tcphdr *th); 336 static void 337 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len, 338 uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t ts, 339 uint8_t pass, struct rack_sendmap *hintrsm); 340 static void 341 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack, 342 struct rack_sendmap *rsm); 343 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, int num); 344 static int32_t rack_output(struct tcpcb *tp); 345 346 static uint32_t 347 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, 348 struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm, 349 uint32_t cts, int *moved_two); 350 static void rack_post_recovery(struct tcpcb *tp, struct tcphdr *th); 351 static void rack_remxt_tmr(struct tcpcb *tp); 352 static int 353 rack_set_sockopt(struct socket *so, struct sockopt *sopt, 354 struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack); 355 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack); 356 static int32_t rack_stopall(struct tcpcb *tp); 357 static void 358 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, 359 uint32_t delta); 360 static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type); 361 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line); 362 static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type); 363 static uint32_t 364 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack, 365 struct rack_sendmap *rsm, uint32_t ts, int32_t * lenp); 366 static void 367 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack, 368 struct rack_sendmap *rsm, uint32_t ts); 369 static int 370 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack, 371 struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type); 372 static int32_t tcp_addrack(module_t mod, int32_t type, void *data); 373 static int 374 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, 375 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 376 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 377 static int 378 rack_do_closing(struct mbuf *m, struct tcphdr *th, 379 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 380 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 381 static int 382 rack_do_established(struct mbuf *m, struct tcphdr *th, 383 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 384 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 385 static int 386 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, 387 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 388 int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos); 389 static int 390 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, 391 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 392 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 393 static int 394 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, 395 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 396 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 397 static int 398 rack_do_lastack(struct mbuf *m, struct tcphdr *th, 399 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 400 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 401 static int 402 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, 403 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 404 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 405 static int 406 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, 407 struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, 408 int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos); 409 struct rack_sendmap * 410 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, 411 uint32_t tsused); 412 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt); 413 static void 414 tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th); 415 416 int32_t rack_clear_counter=0; 417 418 419 static int 420 sysctl_rack_clear(SYSCTL_HANDLER_ARGS) 421 { 422 uint32_t stat; 423 int32_t error; 424 425 error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t)); 426 if (error || req->newptr == NULL) 427 return error; 428 429 error = SYSCTL_IN(req, &stat, sizeof(uint32_t)); 430 if (error) 431 return (error); 432 if (stat == 1) { 433 #ifdef INVARIANTS 434 printf("Clearing RACK counters\n"); 435 #endif 436 counter_u64_zero(rack_badfr); 437 counter_u64_zero(rack_badfr_bytes); 438 counter_u64_zero(rack_rtm_prr_retran); 439 counter_u64_zero(rack_rtm_prr_newdata); 440 counter_u64_zero(rack_timestamp_mismatch); 441 counter_u64_zero(rack_reorder_seen); 442 counter_u64_zero(rack_tlp_tot); 443 counter_u64_zero(rack_tlp_newdata); 444 counter_u64_zero(rack_tlp_retran); 445 counter_u64_zero(rack_tlp_retran_bytes); 446 counter_u64_zero(rack_tlp_retran_fail); 447 counter_u64_zero(rack_to_tot); 448 counter_u64_zero(rack_to_arm_rack); 449 counter_u64_zero(rack_to_arm_tlp); 450 counter_u64_zero(rack_paced_segments); 451 counter_u64_zero(rack_calc_zero); 452 counter_u64_zero(rack_calc_nonzero); 453 counter_u64_zero(rack_unpaced_segments); 454 counter_u64_zero(rack_saw_enobuf); 455 counter_u64_zero(rack_saw_enetunreach); 456 counter_u64_zero(rack_per_timer_hole); 457 counter_u64_zero(rack_to_alloc_hard); 458 counter_u64_zero(rack_to_alloc_emerg); 459 counter_u64_zero(rack_sack_proc_all); 460 counter_u64_zero(rack_sack_proc_short); 461 counter_u64_zero(rack_sack_proc_restart); 462 counter_u64_zero(rack_to_alloc); 463 counter_u64_zero(rack_to_alloc_limited); 464 counter_u64_zero(rack_alloc_limited_conns); 465 counter_u64_zero(rack_split_limited); 466 counter_u64_zero(rack_find_high); 467 counter_u64_zero(rack_tls_rwnd); 468 counter_u64_zero(rack_tls_cwnd); 469 counter_u64_zero(rack_tls_app); 470 counter_u64_zero(rack_tls_other); 471 counter_u64_zero(rack_tls_filled); 472 counter_u64_zero(rack_tls_rxt); 473 counter_u64_zero(rack_tls_tlp); 474 counter_u64_zero(rack_sack_attacks_detected); 475 counter_u64_zero(rack_sack_attacks_reversed); 476 counter_u64_zero(rack_sack_used_next_merge); 477 counter_u64_zero(rack_sack_used_prev_merge); 478 counter_u64_zero(rack_sack_splits); 479 counter_u64_zero(rack_sack_skipped_acked); 480 counter_u64_zero(rack_ack_total); 481 counter_u64_zero(rack_express_sack); 482 counter_u64_zero(rack_sack_total); 483 counter_u64_zero(rack_move_none); 484 counter_u64_zero(rack_move_some); 485 counter_u64_zero(rack_used_tlpmethod); 486 counter_u64_zero(rack_used_tlpmethod2); 487 counter_u64_zero(rack_enter_tlp_calc); 488 counter_u64_zero(rack_progress_drops); 489 counter_u64_zero(rack_tlp_does_nada); 490 counter_u64_zero(rack_collapsed_win); 491 492 } 493 rack_clear_counter = 0; 494 return (0); 495 } 496 497 498 499 static void 500 rack_init_sysctls(void) 501 { 502 struct sysctl_oid *rack_counters; 503 struct sysctl_oid *rack_attack; 504 505 SYSCTL_ADD_S32(&rack_sysctl_ctx, 506 SYSCTL_CHILDREN(rack_sysctl_root), 507 OID_AUTO, "rate_sample_method", CTLFLAG_RW, 508 &rack_rate_sample_method , USE_RTT_LOW, 509 "What method should we use for rate sampling 0=high, 1=low "); 510 SYSCTL_ADD_S32(&rack_sysctl_ctx, 511 SYSCTL_CHILDREN(rack_sysctl_root), 512 OID_AUTO, "hw_tlsmax", CTLFLAG_RW, 513 &rack_hw_tls_max_seg , 0, 514 "Do we have a multplier of TLS records we can send as a max (0=1 TLS record)? "); 515 SYSCTL_ADD_S32(&rack_sysctl_ctx, 516 SYSCTL_CHILDREN(rack_sysctl_root), 517 OID_AUTO, "data_after_close", CTLFLAG_RW, 518 &rack_ignore_data_after_close, 0, 519 "Do we hold off sending a RST until all pending data is ack'd"); 520 SYSCTL_ADD_S32(&rack_sysctl_ctx, 521 SYSCTL_CHILDREN(rack_sysctl_root), 522 OID_AUTO, "cheat_rxt", CTLFLAG_RW, 523 &use_rack_cheat, 1, 524 "Do we use the rxt cheat for rack?"); 525 526 SYSCTL_ADD_U32(&rack_sysctl_ctx, 527 SYSCTL_CHILDREN(rack_sysctl_root), 528 OID_AUTO, "persmin", CTLFLAG_RW, 529 &rack_persist_min, 250, 530 "What is the minimum time in milliseconds between persists"); 531 SYSCTL_ADD_U32(&rack_sysctl_ctx, 532 SYSCTL_CHILDREN(rack_sysctl_root), 533 OID_AUTO, "persmax", CTLFLAG_RW, 534 &rack_persist_max, 1000, 535 "What is the largest delay in milliseconds between persists"); 536 SYSCTL_ADD_S32(&rack_sysctl_ctx, 537 SYSCTL_CHILDREN(rack_sysctl_root), 538 OID_AUTO, "no_sack_needed", CTLFLAG_RW, 539 &rack_sack_not_required, 0, 540 "Do we allow rack to run on connections not supporting SACK?"); 541 SYSCTL_ADD_S32(&rack_sysctl_ctx, 542 SYSCTL_CHILDREN(rack_sysctl_root), 543 OID_AUTO, "tlpmethod", CTLFLAG_RW, 544 &rack_tlp_threshold_use, TLP_USE_TWO_ONE, 545 "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2"); 546 SYSCTL_ADD_S32(&rack_sysctl_ctx, 547 SYSCTL_CHILDREN(rack_sysctl_root), 548 OID_AUTO, "gp_percentage", CTLFLAG_RW, 549 &rack_per_of_gp, 50, 550 "Do we pace to percentage of goodput (0=old method)?"); 551 SYSCTL_ADD_S32(&rack_sysctl_ctx, 552 SYSCTL_CHILDREN(rack_sysctl_root), 553 OID_AUTO, "min_pace_time", CTLFLAG_RW, 554 &rack_min_pace_time, 0, 555 "Should we enforce a minimum pace time of 1ms"); 556 SYSCTL_ADD_S32(&rack_sysctl_ctx, 557 SYSCTL_CHILDREN(rack_sysctl_root), 558 OID_AUTO, "bb_verbose", CTLFLAG_RW, 559 &rack_verbose_logging, 0, 560 "Should RACK black box logging be verbose"); 561 SYSCTL_ADD_S32(&rack_sysctl_ctx, 562 SYSCTL_CHILDREN(rack_sysctl_root), 563 OID_AUTO, "sackfiltering", CTLFLAG_RW, 564 &rack_use_sack_filter, 1, 565 "Do we use sack filtering?"); 566 SYSCTL_ADD_S32(&rack_sysctl_ctx, 567 SYSCTL_CHILDREN(rack_sysctl_root), 568 OID_AUTO, "delayed_ack", CTLFLAG_RW, 569 &rack_delayed_ack_time, 200, 570 "Delayed ack time (200ms)"); 571 SYSCTL_ADD_S32(&rack_sysctl_ctx, 572 SYSCTL_CHILDREN(rack_sysctl_root), 573 OID_AUTO, "tlpminto", CTLFLAG_RW, 574 &rack_tlp_min, 10, 575 "TLP minimum timeout per the specification (10ms)"); 576 SYSCTL_ADD_S32(&rack_sysctl_ctx, 577 SYSCTL_CHILDREN(rack_sysctl_root), 578 OID_AUTO, "send_oldest", CTLFLAG_RW, 579 &rack_always_send_oldest, 1, 580 "Should we always send the oldest TLP and RACK-TLP"); 581 SYSCTL_ADD_S32(&rack_sysctl_ctx, 582 SYSCTL_CHILDREN(rack_sysctl_root), 583 OID_AUTO, "rack_tlimit", CTLFLAG_RW, 584 &rack_limited_retran, 0, 585 "How many times can a rack timeout drive out sends"); 586 SYSCTL_ADD_S32(&rack_sysctl_ctx, 587 SYSCTL_CHILDREN(rack_sysctl_root), 588 OID_AUTO, "minrto", CTLFLAG_RW, 589 &rack_rto_min, 0, 590 "Minimum RTO in ms -- set with caution below 1000 due to TLP"); 591 SYSCTL_ADD_S32(&rack_sysctl_ctx, 592 SYSCTL_CHILDREN(rack_sysctl_root), 593 OID_AUTO, "maxrto", CTLFLAG_RW, 594 &rack_rto_max, 0, 595 "Maxiumum RTO in ms -- should be at least as large as min_rto"); 596 SYSCTL_ADD_S32(&rack_sysctl_ctx, 597 SYSCTL_CHILDREN(rack_sysctl_root), 598 OID_AUTO, "tlp_retry", CTLFLAG_RW, 599 &rack_tlp_max_resend, 2, 600 "How many times does TLP retry a single segment or multiple with no ACK"); 601 SYSCTL_ADD_S32(&rack_sysctl_ctx, 602 SYSCTL_CHILDREN(rack_sysctl_root), 603 OID_AUTO, "recovery_loss_prop", CTLFLAG_RW, 604 &rack_use_proportional_reduce, 0, 605 "Should we proportionaly reduce cwnd based on the number of losses "); 606 SYSCTL_ADD_S32(&rack_sysctl_ctx, 607 SYSCTL_CHILDREN(rack_sysctl_root), 608 OID_AUTO, "recovery_prop", CTLFLAG_RW, 609 &rack_proportional_rate, 10, 610 "What percent reduction per loss"); 611 SYSCTL_ADD_S32(&rack_sysctl_ctx, 612 SYSCTL_CHILDREN(rack_sysctl_root), 613 OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW, 614 &rack_lower_cwnd_at_tlp, 0, 615 "When a TLP completes a retran should we enter recovery?"); 616 SYSCTL_ADD_S32(&rack_sysctl_ctx, 617 SYSCTL_CHILDREN(rack_sysctl_root), 618 OID_AUTO, "hptsi_reduces", CTLFLAG_RW, 619 &rack_slot_reduction, 4, 620 "When setting a slot should we reduce by divisor"); 621 SYSCTL_ADD_S32(&rack_sysctl_ctx, 622 SYSCTL_CHILDREN(rack_sysctl_root), 623 OID_AUTO, "hptsi_every_seg", CTLFLAG_RW, 624 &rack_pace_every_seg, 0, 625 "Should we use the original pacing mechanism that did not pace much?"); 626 SYSCTL_ADD_S32(&rack_sysctl_ctx, 627 SYSCTL_CHILDREN(rack_sysctl_root), 628 OID_AUTO, "hptsi_seg_max", CTLFLAG_RW, 629 &rack_hptsi_segments, 40, 630 "Should we pace out only a limited size of segments"); 631 SYSCTL_ADD_S32(&rack_sysctl_ctx, 632 SYSCTL_CHILDREN(rack_sysctl_root), 633 OID_AUTO, "prr_sendalot", CTLFLAG_RW, 634 &rack_send_a_lot_in_prr, 1, 635 "Send a lot in prr"); 636 SYSCTL_ADD_S32(&rack_sysctl_ctx, 637 SYSCTL_CHILDREN(rack_sysctl_root), 638 OID_AUTO, "minto", CTLFLAG_RW, 639 &rack_min_to, 1, 640 "Minimum rack timeout in milliseconds"); 641 SYSCTL_ADD_S32(&rack_sysctl_ctx, 642 SYSCTL_CHILDREN(rack_sysctl_root), 643 OID_AUTO, "earlyrecovery", CTLFLAG_RW, 644 &rack_early_recovery, 1, 645 "Do we do early recovery with rack"); 646 SYSCTL_ADD_S32(&rack_sysctl_ctx, 647 SYSCTL_CHILDREN(rack_sysctl_root), 648 OID_AUTO, "reorder_thresh", CTLFLAG_RW, 649 &rack_reorder_thresh, 2, 650 "What factor for rack will be added when seeing reordering (shift right)"); 651 SYSCTL_ADD_S32(&rack_sysctl_ctx, 652 SYSCTL_CHILDREN(rack_sysctl_root), 653 OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW, 654 &rack_tlp_thresh, 1, 655 "what divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)"); 656 SYSCTL_ADD_S32(&rack_sysctl_ctx, 657 SYSCTL_CHILDREN(rack_sysctl_root), 658 OID_AUTO, "reorder_fade", CTLFLAG_RW, 659 &rack_reorder_fade, 0, 660 "Does reorder detection fade, if so how many ms (0 means never)"); 661 SYSCTL_ADD_S32(&rack_sysctl_ctx, 662 SYSCTL_CHILDREN(rack_sysctl_root), 663 OID_AUTO, "pktdelay", CTLFLAG_RW, 664 &rack_pkt_delay, 1, 665 "Extra RACK time (in ms) besides reordering thresh"); 666 667 rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx, 668 SYSCTL_CHILDREN(rack_sysctl_root), 669 OID_AUTO, 670 "stats", 671 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 672 "Rack Counters"); 673 rack_badfr = counter_u64_alloc(M_WAITOK); 674 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 675 SYSCTL_CHILDREN(rack_counters), 676 OID_AUTO, "badfr", CTLFLAG_RD, 677 &rack_badfr, "Total number of bad FRs"); 678 rack_badfr_bytes = counter_u64_alloc(M_WAITOK); 679 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 680 SYSCTL_CHILDREN(rack_counters), 681 OID_AUTO, "badfr_bytes", CTLFLAG_RD, 682 &rack_badfr_bytes, "Total number of bad FRs"); 683 rack_rtm_prr_retran = counter_u64_alloc(M_WAITOK); 684 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 685 SYSCTL_CHILDREN(rack_counters), 686 OID_AUTO, "prrsndret", CTLFLAG_RD, 687 &rack_rtm_prr_retran, 688 "Total number of prr based retransmits"); 689 rack_rtm_prr_newdata = counter_u64_alloc(M_WAITOK); 690 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 691 SYSCTL_CHILDREN(rack_counters), 692 OID_AUTO, "prrsndnew", CTLFLAG_RD, 693 &rack_rtm_prr_newdata, 694 "Total number of prr based new transmits"); 695 rack_timestamp_mismatch = counter_u64_alloc(M_WAITOK); 696 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 697 SYSCTL_CHILDREN(rack_counters), 698 OID_AUTO, "tsnf", CTLFLAG_RD, 699 &rack_timestamp_mismatch, 700 "Total number of timestamps that we could not find the reported ts"); 701 rack_find_high = counter_u64_alloc(M_WAITOK); 702 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 703 SYSCTL_CHILDREN(rack_counters), 704 OID_AUTO, "findhigh", CTLFLAG_RD, 705 &rack_find_high, 706 "Total number of FIN causing find-high"); 707 rack_reorder_seen = counter_u64_alloc(M_WAITOK); 708 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 709 SYSCTL_CHILDREN(rack_counters), 710 OID_AUTO, "reordering", CTLFLAG_RD, 711 &rack_reorder_seen, 712 "Total number of times we added delay due to reordering"); 713 rack_tlp_tot = counter_u64_alloc(M_WAITOK); 714 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 715 SYSCTL_CHILDREN(rack_counters), 716 OID_AUTO, "tlp_to_total", CTLFLAG_RD, 717 &rack_tlp_tot, 718 "Total number of tail loss probe expirations"); 719 rack_tlp_newdata = counter_u64_alloc(M_WAITOK); 720 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 721 SYSCTL_CHILDREN(rack_counters), 722 OID_AUTO, "tlp_new", CTLFLAG_RD, 723 &rack_tlp_newdata, 724 "Total number of tail loss probe sending new data"); 725 726 rack_tlp_retran = counter_u64_alloc(M_WAITOK); 727 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 728 SYSCTL_CHILDREN(rack_counters), 729 OID_AUTO, "tlp_retran", CTLFLAG_RD, 730 &rack_tlp_retran, 731 "Total number of tail loss probe sending retransmitted data"); 732 rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK); 733 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 734 SYSCTL_CHILDREN(rack_counters), 735 OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD, 736 &rack_tlp_retran_bytes, 737 "Total bytes of tail loss probe sending retransmitted data"); 738 rack_tlp_retran_fail = counter_u64_alloc(M_WAITOK); 739 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 740 SYSCTL_CHILDREN(rack_counters), 741 OID_AUTO, "tlp_retran_fail", CTLFLAG_RD, 742 &rack_tlp_retran_fail, 743 "Total number of tail loss probe sending retransmitted data that failed (wait for t3)"); 744 rack_to_tot = counter_u64_alloc(M_WAITOK); 745 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 746 SYSCTL_CHILDREN(rack_counters), 747 OID_AUTO, "rack_to_tot", CTLFLAG_RD, 748 &rack_to_tot, 749 "Total number of times the rack to expired?"); 750 rack_to_arm_rack = counter_u64_alloc(M_WAITOK); 751 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 752 SYSCTL_CHILDREN(rack_counters), 753 OID_AUTO, "arm_rack", CTLFLAG_RD, 754 &rack_to_arm_rack, 755 "Total number of times the rack timer armed?"); 756 rack_to_arm_tlp = counter_u64_alloc(M_WAITOK); 757 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 758 SYSCTL_CHILDREN(rack_counters), 759 OID_AUTO, "arm_tlp", CTLFLAG_RD, 760 &rack_to_arm_tlp, 761 "Total number of times the tlp timer armed?"); 762 763 rack_calc_zero = counter_u64_alloc(M_WAITOK); 764 rack_calc_nonzero = counter_u64_alloc(M_WAITOK); 765 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 766 SYSCTL_CHILDREN(rack_counters), 767 OID_AUTO, "calc_zero", CTLFLAG_RD, 768 &rack_calc_zero, 769 "Total number of times pacing time worked out to zero?"); 770 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 771 SYSCTL_CHILDREN(rack_counters), 772 OID_AUTO, "calc_nonzero", CTLFLAG_RD, 773 &rack_calc_nonzero, 774 "Total number of times pacing time worked out to non-zero?"); 775 rack_paced_segments = counter_u64_alloc(M_WAITOK); 776 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 777 SYSCTL_CHILDREN(rack_counters), 778 OID_AUTO, "paced", CTLFLAG_RD, 779 &rack_paced_segments, 780 "Total number of times a segment send caused hptsi"); 781 rack_unpaced_segments = counter_u64_alloc(M_WAITOK); 782 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 783 SYSCTL_CHILDREN(rack_counters), 784 OID_AUTO, "unpaced", CTLFLAG_RD, 785 &rack_unpaced_segments, 786 "Total number of times a segment did not cause hptsi"); 787 rack_saw_enobuf = counter_u64_alloc(M_WAITOK); 788 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 789 SYSCTL_CHILDREN(rack_counters), 790 OID_AUTO, "saw_enobufs", CTLFLAG_RD, 791 &rack_saw_enobuf, 792 "Total number of times a segment did not cause hptsi"); 793 rack_saw_enetunreach = counter_u64_alloc(M_WAITOK); 794 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 795 SYSCTL_CHILDREN(rack_counters), 796 OID_AUTO, "saw_enetunreach", CTLFLAG_RD, 797 &rack_saw_enetunreach, 798 "Total number of times a segment did not cause hptsi"); 799 rack_to_alloc = counter_u64_alloc(M_WAITOK); 800 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 801 SYSCTL_CHILDREN(rack_counters), 802 OID_AUTO, "allocs", CTLFLAG_RD, 803 &rack_to_alloc, 804 "Total allocations of tracking structures"); 805 rack_to_alloc_hard = counter_u64_alloc(M_WAITOK); 806 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 807 SYSCTL_CHILDREN(rack_counters), 808 OID_AUTO, "allochard", CTLFLAG_RD, 809 &rack_to_alloc_hard, 810 "Total allocations done with sleeping the hard way"); 811 rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK); 812 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 813 SYSCTL_CHILDREN(rack_counters), 814 OID_AUTO, "allocemerg", CTLFLAG_RD, 815 &rack_to_alloc_emerg, 816 "Total allocations done from emergency cache"); 817 rack_to_alloc_limited = counter_u64_alloc(M_WAITOK); 818 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 819 SYSCTL_CHILDREN(rack_counters), 820 OID_AUTO, "alloc_limited", CTLFLAG_RD, 821 &rack_to_alloc_limited, 822 "Total allocations dropped due to limit"); 823 rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK); 824 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 825 SYSCTL_CHILDREN(rack_counters), 826 OID_AUTO, "alloc_limited_conns", CTLFLAG_RD, 827 &rack_alloc_limited_conns, 828 "Connections with allocations dropped due to limit"); 829 rack_split_limited = counter_u64_alloc(M_WAITOK); 830 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 831 SYSCTL_CHILDREN(rack_counters), 832 OID_AUTO, "split_limited", CTLFLAG_RD, 833 &rack_split_limited, 834 "Split allocations dropped due to limit"); 835 rack_sack_proc_all = counter_u64_alloc(M_WAITOK); 836 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 837 SYSCTL_CHILDREN(rack_counters), 838 OID_AUTO, "sack_long", CTLFLAG_RD, 839 &rack_sack_proc_all, 840 "Total times we had to walk whole list for sack processing"); 841 842 rack_sack_proc_restart = counter_u64_alloc(M_WAITOK); 843 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 844 SYSCTL_CHILDREN(rack_counters), 845 OID_AUTO, "sack_restart", CTLFLAG_RD, 846 &rack_sack_proc_restart, 847 "Total times we had to walk whole list due to a restart"); 848 rack_sack_proc_short = counter_u64_alloc(M_WAITOK); 849 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 850 SYSCTL_CHILDREN(rack_counters), 851 OID_AUTO, "sack_short", CTLFLAG_RD, 852 &rack_sack_proc_short, 853 "Total times we took shortcut for sack processing"); 854 rack_enter_tlp_calc = counter_u64_alloc(M_WAITOK); 855 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 856 SYSCTL_CHILDREN(rack_counters), 857 OID_AUTO, "tlp_calc_entered", CTLFLAG_RD, 858 &rack_enter_tlp_calc, 859 "Total times we called calc-tlp"); 860 rack_used_tlpmethod = counter_u64_alloc(M_WAITOK); 861 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 862 SYSCTL_CHILDREN(rack_counters), 863 OID_AUTO, "hit_tlp_method", CTLFLAG_RD, 864 &rack_used_tlpmethod, 865 "Total number of runt sacks"); 866 rack_used_tlpmethod2 = counter_u64_alloc(M_WAITOK); 867 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 868 SYSCTL_CHILDREN(rack_counters), 869 OID_AUTO, "hit_tlp_method2", CTLFLAG_RD, 870 &rack_used_tlpmethod2, 871 "Total number of times we hit TLP method 2"); 872 /* Sack Attacker detection stuff */ 873 rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx, 874 SYSCTL_CHILDREN(rack_sysctl_root), 875 OID_AUTO, 876 "sack_attack", 877 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 878 "Rack Sack Attack Counters and Controls"); 879 SYSCTL_ADD_U32(&rack_sysctl_ctx, 880 SYSCTL_CHILDREN(rack_attack), 881 OID_AUTO, "detect_highsackratio", CTLFLAG_RW, 882 &rack_highest_sack_thresh_seen, 0, 883 "Highest sack to ack ratio seen"); 884 SYSCTL_ADD_U32(&rack_sysctl_ctx, 885 SYSCTL_CHILDREN(rack_attack), 886 OID_AUTO, "detect_highmoveratio", CTLFLAG_RW, 887 &rack_highest_move_thresh_seen, 0, 888 "Highest move to non-move ratio seen"); 889 rack_ack_total = counter_u64_alloc(M_WAITOK); 890 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 891 SYSCTL_CHILDREN(rack_attack), 892 OID_AUTO, "acktotal", CTLFLAG_RD, 893 &rack_ack_total, 894 "Total number of Ack's"); 895 896 rack_express_sack = counter_u64_alloc(M_WAITOK); 897 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 898 SYSCTL_CHILDREN(rack_attack), 899 OID_AUTO, "exp_sacktotal", CTLFLAG_RD, 900 &rack_express_sack, 901 "Total expresss number of Sack's"); 902 rack_sack_total = counter_u64_alloc(M_WAITOK); 903 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 904 SYSCTL_CHILDREN(rack_attack), 905 OID_AUTO, "sacktotal", CTLFLAG_RD, 906 &rack_sack_total, 907 "Total number of SACK's"); 908 rack_move_none = counter_u64_alloc(M_WAITOK); 909 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 910 SYSCTL_CHILDREN(rack_attack), 911 OID_AUTO, "move_none", CTLFLAG_RD, 912 &rack_move_none, 913 "Total number of SACK index reuse of postions under threshold"); 914 rack_move_some = counter_u64_alloc(M_WAITOK); 915 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 916 SYSCTL_CHILDREN(rack_attack), 917 OID_AUTO, "move_some", CTLFLAG_RD, 918 &rack_move_some, 919 "Total number of SACK index reuse of postions over threshold"); 920 rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK); 921 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 922 SYSCTL_CHILDREN(rack_attack), 923 OID_AUTO, "attacks", CTLFLAG_RD, 924 &rack_sack_attacks_detected, 925 "Total number of SACK attackers that had sack disabled"); 926 rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK); 927 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 928 SYSCTL_CHILDREN(rack_attack), 929 OID_AUTO, "reversed", CTLFLAG_RD, 930 &rack_sack_attacks_reversed, 931 "Total number of SACK attackers that were later determined false positive"); 932 rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK); 933 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 934 SYSCTL_CHILDREN(rack_attack), 935 OID_AUTO, "nextmerge", CTLFLAG_RD, 936 &rack_sack_used_next_merge, 937 "Total number of times we used the next merge"); 938 rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK); 939 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 940 SYSCTL_CHILDREN(rack_attack), 941 OID_AUTO, "prevmerge", CTLFLAG_RD, 942 &rack_sack_used_prev_merge, 943 "Total number of times we used the prev merge"); 944 rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK); 945 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 946 SYSCTL_CHILDREN(rack_attack), 947 OID_AUTO, "skipacked", CTLFLAG_RD, 948 &rack_sack_skipped_acked, 949 "Total number of times we skipped previously sacked"); 950 rack_sack_splits = counter_u64_alloc(M_WAITOK); 951 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 952 SYSCTL_CHILDREN(rack_attack), 953 OID_AUTO, "ofsplit", CTLFLAG_RD, 954 &rack_sack_splits, 955 "Total number of times we did the old fashion tree split"); 956 rack_progress_drops = counter_u64_alloc(M_WAITOK); 957 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 958 SYSCTL_CHILDREN(rack_counters), 959 OID_AUTO, "prog_drops", CTLFLAG_RD, 960 &rack_progress_drops, 961 "Total number of progress drops"); 962 rack_input_idle_reduces = counter_u64_alloc(M_WAITOK); 963 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 964 SYSCTL_CHILDREN(rack_counters), 965 OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD, 966 &rack_input_idle_reduces, 967 "Total number of idle reductions on input"); 968 rack_collapsed_win = counter_u64_alloc(M_WAITOK); 969 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 970 SYSCTL_CHILDREN(rack_counters), 971 OID_AUTO, "collapsed_win", CTLFLAG_RD, 972 &rack_collapsed_win, 973 "Total number of collapsed windows"); 974 rack_tlp_does_nada = counter_u64_alloc(M_WAITOK); 975 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 976 SYSCTL_CHILDREN(rack_counters), 977 OID_AUTO, "tlp_nada", CTLFLAG_RD, 978 &rack_tlp_does_nada, 979 "Total number of nada tlp calls"); 980 981 rack_tls_rwnd = counter_u64_alloc(M_WAITOK); 982 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 983 SYSCTL_CHILDREN(rack_counters), 984 OID_AUTO, "tls_rwnd", CTLFLAG_RD, 985 &rack_tls_rwnd, 986 "Total hdwr tls rwnd limited"); 987 988 rack_tls_cwnd = counter_u64_alloc(M_WAITOK); 989 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 990 SYSCTL_CHILDREN(rack_counters), 991 OID_AUTO, "tls_cwnd", CTLFLAG_RD, 992 &rack_tls_cwnd, 993 "Total hdwr tls cwnd limited"); 994 995 rack_tls_app = counter_u64_alloc(M_WAITOK); 996 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 997 SYSCTL_CHILDREN(rack_counters), 998 OID_AUTO, "tls_app", CTLFLAG_RD, 999 &rack_tls_app, 1000 "Total hdwr tls app limited"); 1001 1002 rack_tls_other = counter_u64_alloc(M_WAITOK); 1003 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 1004 SYSCTL_CHILDREN(rack_counters), 1005 OID_AUTO, "tls_other", CTLFLAG_RD, 1006 &rack_tls_other, 1007 "Total hdwr tls other limited"); 1008 1009 rack_tls_filled = counter_u64_alloc(M_WAITOK); 1010 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 1011 SYSCTL_CHILDREN(rack_counters), 1012 OID_AUTO, "tls_filled", CTLFLAG_RD, 1013 &rack_tls_filled, 1014 "Total hdwr tls filled"); 1015 1016 rack_tls_rxt = counter_u64_alloc(M_WAITOK); 1017 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 1018 SYSCTL_CHILDREN(rack_counters), 1019 OID_AUTO, "tls_rxt", CTLFLAG_RD, 1020 &rack_tls_rxt, 1021 "Total hdwr rxt"); 1022 1023 rack_tls_tlp = counter_u64_alloc(M_WAITOK); 1024 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 1025 SYSCTL_CHILDREN(rack_counters), 1026 OID_AUTO, "tls_tlp", CTLFLAG_RD, 1027 &rack_tls_tlp, 1028 "Total hdwr tls tlp"); 1029 rack_per_timer_hole = counter_u64_alloc(M_WAITOK); 1030 SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx, 1031 SYSCTL_CHILDREN(rack_counters), 1032 OID_AUTO, "timer_hole", CTLFLAG_RD, 1033 &rack_per_timer_hole, 1034 "Total persists start in timer hole"); 1035 1036 COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK); 1037 SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root), 1038 OID_AUTO, "outsize", CTLFLAG_RD, 1039 rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes"); 1040 COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK); 1041 SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root), 1042 OID_AUTO, "opts", CTLFLAG_RD, 1043 rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats"); 1044 SYSCTL_ADD_PROC(&rack_sysctl_ctx, 1045 SYSCTL_CHILDREN(rack_sysctl_root), 1046 OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE, 1047 &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters"); 1048 } 1049 1050 static __inline int 1051 rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a) 1052 { 1053 if (SEQ_GEQ(b->r_start, a->r_start) && 1054 SEQ_LT(b->r_start, a->r_end)) { 1055 /* 1056 * The entry b is within the 1057 * block a. i.e.: 1058 * a -- |-------------| 1059 * b -- |----| 1060 * <or> 1061 * b -- |------| 1062 * <or> 1063 * b -- |-----------| 1064 */ 1065 return (0); 1066 } else if (SEQ_GEQ(b->r_start, a->r_end)) { 1067 /* 1068 * b falls as either the next 1069 * sequence block after a so a 1070 * is said to be smaller than b. 1071 * i.e: 1072 * a -- |------| 1073 * b -- |--------| 1074 * or 1075 * b -- |-----| 1076 */ 1077 return (1); 1078 } 1079 /* 1080 * Whats left is where a is 1081 * larger than b. i.e: 1082 * a -- |-------| 1083 * b -- |---| 1084 * or even possibly 1085 * b -- |--------------| 1086 */ 1087 return (-1); 1088 } 1089 1090 RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp); 1091 RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp); 1092 1093 static inline int32_t 1094 rack_progress_timeout_check(struct tcpcb *tp) 1095 { 1096 if (tp->t_maxunacktime && tp->t_acktime && TSTMP_GT(ticks, tp->t_acktime)) { 1097 if ((ticks - tp->t_acktime) >= tp->t_maxunacktime) { 1098 /* 1099 * There is an assumption that the caller 1100 * will drop the connection so we will 1101 * increment the counters here. 1102 */ 1103 struct tcp_rack *rack; 1104 rack = (struct tcp_rack *)tp->t_fb_ptr; 1105 counter_u64_add(rack_progress_drops, 1); 1106 #ifdef NETFLIX_STATS 1107 KMOD_TCPSTAT_INC(tcps_progdrops); 1108 #endif 1109 rack_log_progress_event(rack, tp, ticks, PROGRESS_DROP, __LINE__); 1110 return (1); 1111 } 1112 } 1113 return (0); 1114 } 1115 1116 1117 1118 static void 1119 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod) 1120 { 1121 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1122 union tcp_log_stackspecific log; 1123 struct timeval tv; 1124 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1125 log.u_bbr.flex1 = tsused; 1126 log.u_bbr.flex2 = thresh; 1127 log.u_bbr.flex3 = rsm->r_flags; 1128 log.u_bbr.flex4 = rsm->r_dupack; 1129 log.u_bbr.flex5 = rsm->r_start; 1130 log.u_bbr.flex6 = rsm->r_end; 1131 log.u_bbr.flex8 = mod; 1132 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1133 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1134 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1135 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1136 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1137 &rack->rc_inp->inp_socket->so_rcv, 1138 &rack->rc_inp->inp_socket->so_snd, 1139 BBR_LOG_SETTINGS_CHG, 0, 1140 0, &log, false, &tv); 1141 } 1142 } 1143 1144 1145 1146 static void 1147 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which) 1148 { 1149 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1150 union tcp_log_stackspecific log; 1151 struct timeval tv; 1152 1153 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1154 log.u_bbr.flex1 = TICKS_2_MSEC(rack->rc_tp->t_srtt >> TCP_RTT_SHIFT); 1155 log.u_bbr.flex2 = to; 1156 log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags; 1157 log.u_bbr.flex4 = slot; 1158 log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot; 1159 log.u_bbr.flex6 = rack->rc_tp->t_rxtcur; 1160 log.u_bbr.flex7 = rack->rc_in_persist; 1161 log.u_bbr.flex8 = which; 1162 log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt; 1163 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1164 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1165 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1166 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1167 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1168 &rack->rc_inp->inp_socket->so_rcv, 1169 &rack->rc_inp->inp_socket->so_snd, 1170 BBR_LOG_TIMERSTAR, 0, 1171 0, &log, false, &tv); 1172 } 1173 } 1174 1175 static void 1176 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, int no) 1177 { 1178 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1179 union tcp_log_stackspecific log; 1180 struct timeval tv; 1181 1182 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1183 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1184 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1185 log.u_bbr.flex8 = to_num; 1186 log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt; 1187 log.u_bbr.flex2 = rack->rc_rack_rtt; 1188 log.u_bbr.flex3 = no; 1189 log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt; 1190 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1191 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1192 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1193 &rack->rc_inp->inp_socket->so_rcv, 1194 &rack->rc_inp->inp_socket->so_snd, 1195 BBR_LOG_RTO, 0, 1196 0, &log, false, &tv); 1197 } 1198 } 1199 1200 static void 1201 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, int32_t t, 1202 uint32_t o_srtt, uint32_t o_var) 1203 { 1204 if (tp->t_logstate != TCP_LOG_STATE_OFF) { 1205 union tcp_log_stackspecific log; 1206 struct timeval tv; 1207 1208 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1209 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1210 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1211 log.u_bbr.flex1 = t; 1212 log.u_bbr.flex2 = o_srtt; 1213 log.u_bbr.flex3 = o_var; 1214 log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest; 1215 log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest; 1216 log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_rtt_cnt; 1217 log.u_bbr.rttProp = rack->r_ctl.rack_rs.rs_rtt_tot; 1218 log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method; 1219 log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt; 1220 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1221 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1222 TCP_LOG_EVENTP(tp, NULL, 1223 &rack->rc_inp->inp_socket->so_rcv, 1224 &rack->rc_inp->inp_socket->so_snd, 1225 BBR_LOG_BBRRTT, 0, 1226 0, &log, false, &tv); 1227 } 1228 } 1229 1230 static void 1231 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt) 1232 { 1233 /* 1234 * Log the rtt sample we are 1235 * applying to the srtt algorithm in 1236 * useconds. 1237 */ 1238 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1239 union tcp_log_stackspecific log; 1240 struct timeval tv; 1241 1242 /* Convert our ms to a microsecond */ 1243 memset(&log, 0, sizeof(log)); 1244 log.u_bbr.flex1 = rtt * 1000; 1245 log.u_bbr.flex2 = rack->r_ctl.ack_count; 1246 log.u_bbr.flex3 = rack->r_ctl.sack_count; 1247 log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move; 1248 log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra; 1249 log.u_bbr.flex8 = rack->sack_attack_disable; 1250 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1251 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1252 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1253 &rack->rc_inp->inp_socket->so_rcv, 1254 &rack->rc_inp->inp_socket->so_snd, 1255 TCP_LOG_RTT, 0, 1256 0, &log, false, &tv); 1257 } 1258 } 1259 1260 1261 static inline void 1262 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick, int event, int line) 1263 { 1264 if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) { 1265 union tcp_log_stackspecific log; 1266 struct timeval tv; 1267 1268 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1269 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1270 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1271 log.u_bbr.flex1 = line; 1272 log.u_bbr.flex2 = tick; 1273 log.u_bbr.flex3 = tp->t_maxunacktime; 1274 log.u_bbr.flex4 = tp->t_acktime; 1275 log.u_bbr.flex8 = event; 1276 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1277 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1278 TCP_LOG_EVENTP(tp, NULL, 1279 &rack->rc_inp->inp_socket->so_rcv, 1280 &rack->rc_inp->inp_socket->so_snd, 1281 BBR_LOG_PROGRESS, 0, 1282 0, &log, false, &tv); 1283 } 1284 } 1285 1286 static void 1287 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts) 1288 { 1289 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1290 union tcp_log_stackspecific log; 1291 struct timeval tv; 1292 1293 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1294 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1295 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1296 log.u_bbr.flex1 = slot; 1297 log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt; 1298 log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags); 1299 log.u_bbr.flex8 = rack->rc_in_persist; 1300 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1301 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1302 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1303 &rack->rc_inp->inp_socket->so_rcv, 1304 &rack->rc_inp->inp_socket->so_snd, 1305 BBR_LOG_BBRSND, 0, 1306 0, &log, false, &tv); 1307 } 1308 } 1309 1310 static void 1311 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out) 1312 { 1313 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1314 union tcp_log_stackspecific log; 1315 struct timeval tv; 1316 1317 memset(&log, 0, sizeof(log)); 1318 log.u_bbr.flex1 = did_out; 1319 log.u_bbr.flex2 = nxt_pkt; 1320 log.u_bbr.flex3 = way_out; 1321 log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags; 1322 log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt; 1323 log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs; 1324 log.u_bbr.flex7 = rack->r_wanted_output; 1325 log.u_bbr.flex8 = rack->rc_in_persist; 1326 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1327 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1328 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1329 &rack->rc_inp->inp_socket->so_rcv, 1330 &rack->rc_inp->inp_socket->so_snd, 1331 BBR_LOG_DOSEG_DONE, 0, 1332 0, &log, false, &tv); 1333 } 1334 } 1335 1336 static void 1337 rack_log_type_hrdwtso(struct tcpcb *tp, struct tcp_rack *rack, int len, int mod, int32_t orig_len, int frm) 1338 { 1339 if (tp->t_logstate != TCP_LOG_STATE_OFF) { 1340 union tcp_log_stackspecific log; 1341 struct timeval tv; 1342 uint32_t cts; 1343 1344 memset(&log, 0, sizeof(log)); 1345 cts = tcp_get_usecs(&tv); 1346 log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs; 1347 log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs; 1348 log.u_bbr.flex4 = len; 1349 log.u_bbr.flex5 = orig_len; 1350 log.u_bbr.flex6 = rack->r_ctl.rc_sacked; 1351 log.u_bbr.flex7 = mod; 1352 log.u_bbr.flex8 = frm; 1353 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1354 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1355 TCP_LOG_EVENTP(tp, NULL, 1356 &tp->t_inpcb->inp_socket->so_rcv, 1357 &tp->t_inpcb->inp_socket->so_snd, 1358 TCP_HDWR_TLS, 0, 1359 0, &log, false, &tv); 1360 } 1361 } 1362 1363 static void 1364 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot, uint8_t hpts_calling) 1365 { 1366 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1367 union tcp_log_stackspecific log; 1368 struct timeval tv; 1369 1370 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1371 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1372 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1373 log.u_bbr.flex1 = slot; 1374 log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags; 1375 log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt; 1376 log.u_bbr.flex7 = hpts_calling; 1377 log.u_bbr.flex8 = rack->rc_in_persist; 1378 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1379 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1380 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1381 &rack->rc_inp->inp_socket->so_rcv, 1382 &rack->rc_inp->inp_socket->so_snd, 1383 BBR_LOG_JUSTRET, 0, 1384 tlen, &log, false, &tv); 1385 } 1386 } 1387 1388 static void 1389 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line) 1390 { 1391 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1392 union tcp_log_stackspecific log; 1393 struct timeval tv; 1394 1395 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1396 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 1397 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 1398 log.u_bbr.flex1 = line; 1399 log.u_bbr.flex2 = 0; 1400 log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags; 1401 log.u_bbr.flex4 = 0; 1402 log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt; 1403 log.u_bbr.flex6 = rack->rc_tp->t_rxtcur; 1404 log.u_bbr.flex8 = hpts_removed; 1405 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1406 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1407 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1408 &rack->rc_inp->inp_socket->so_rcv, 1409 &rack->rc_inp->inp_socket->so_snd, 1410 BBR_LOG_TIMERCANC, 0, 1411 0, &log, false, &tv); 1412 } 1413 } 1414 1415 static void 1416 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers) 1417 { 1418 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1419 union tcp_log_stackspecific log; 1420 struct timeval tv; 1421 1422 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1423 log.u_bbr.flex1 = timers; 1424 log.u_bbr.flex2 = ret; 1425 log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp; 1426 log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags; 1427 log.u_bbr.flex5 = cts; 1428 log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt; 1429 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1430 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1431 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1432 &rack->rc_inp->inp_socket->so_rcv, 1433 &rack->rc_inp->inp_socket->so_snd, 1434 BBR_LOG_TO_PROCESS, 0, 1435 0, &log, false, &tv); 1436 } 1437 } 1438 1439 static void 1440 rack_log_to_prr(struct tcp_rack *rack, int frm) 1441 { 1442 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1443 union tcp_log_stackspecific log; 1444 struct timeval tv; 1445 1446 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1447 log.u_bbr.flex1 = rack->r_ctl.rc_prr_out; 1448 log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs; 1449 log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt; 1450 log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered; 1451 log.u_bbr.flex5 = rack->r_ctl.rc_sacked; 1452 log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt; 1453 log.u_bbr.flex8 = frm; 1454 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1455 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1456 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1457 &rack->rc_inp->inp_socket->so_rcv, 1458 &rack->rc_inp->inp_socket->so_snd, 1459 BBR_LOG_BBRUPD, 0, 1460 0, &log, false, &tv); 1461 } 1462 } 1463 1464 #ifdef NETFLIX_EXP_DETECTION 1465 static void 1466 rack_log_sad(struct tcp_rack *rack, int event) 1467 { 1468 if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) { 1469 union tcp_log_stackspecific log; 1470 struct timeval tv; 1471 1472 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 1473 log.u_bbr.flex1 = rack->r_ctl.sack_count; 1474 log.u_bbr.flex2 = rack->r_ctl.ack_count; 1475 log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra; 1476 log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move; 1477 log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced; 1478 log.u_bbr.flex6 = tcp_sack_to_ack_thresh; 1479 log.u_bbr.pkts_out = tcp_sack_to_move_thresh; 1480 log.u_bbr.lt_epoch = (tcp_force_detection << 8); 1481 log.u_bbr.lt_epoch |= rack->do_detection; 1482 log.u_bbr.applimited = tcp_map_minimum; 1483 log.u_bbr.flex7 = rack->sack_attack_disable; 1484 log.u_bbr.flex8 = event; 1485 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 1486 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 1487 log.u_bbr.delivered = tcp_sad_decay_val; 1488 TCP_LOG_EVENTP(rack->rc_tp, NULL, 1489 &rack->rc_inp->inp_socket->so_rcv, 1490 &rack->rc_inp->inp_socket->so_snd, 1491 TCP_SAD_DETECTION, 0, 1492 0, &log, false, &tv); 1493 } 1494 } 1495 #endif 1496 1497 static void 1498 rack_counter_destroy(void) 1499 { 1500 counter_u64_free(rack_badfr); 1501 counter_u64_free(rack_badfr_bytes); 1502 counter_u64_free(rack_rtm_prr_retran); 1503 counter_u64_free(rack_rtm_prr_newdata); 1504 counter_u64_free(rack_timestamp_mismatch); 1505 counter_u64_free(rack_reorder_seen); 1506 counter_u64_free(rack_tlp_tot); 1507 counter_u64_free(rack_tlp_newdata); 1508 counter_u64_free(rack_tlp_retran); 1509 counter_u64_free(rack_tlp_retran_bytes); 1510 counter_u64_free(rack_tlp_retran_fail); 1511 counter_u64_free(rack_to_tot); 1512 counter_u64_free(rack_to_arm_rack); 1513 counter_u64_free(rack_to_arm_tlp); 1514 counter_u64_free(rack_paced_segments); 1515 counter_u64_free(rack_unpaced_segments); 1516 counter_u64_free(rack_saw_enobuf); 1517 counter_u64_free(rack_saw_enetunreach); 1518 counter_u64_free(rack_to_alloc_hard); 1519 counter_u64_free(rack_to_alloc_emerg); 1520 counter_u64_free(rack_sack_proc_all); 1521 counter_u64_free(rack_sack_proc_short); 1522 counter_u64_free(rack_sack_proc_restart); 1523 counter_u64_free(rack_to_alloc); 1524 counter_u64_free(rack_to_alloc_limited); 1525 counter_u64_free(rack_alloc_limited_conns); 1526 counter_u64_free(rack_split_limited); 1527 counter_u64_free(rack_find_high); 1528 counter_u64_free(rack_enter_tlp_calc); 1529 counter_u64_free(rack_used_tlpmethod); 1530 counter_u64_free(rack_used_tlpmethod2); 1531 counter_u64_free(rack_progress_drops); 1532 counter_u64_free(rack_input_idle_reduces); 1533 counter_u64_free(rack_collapsed_win); 1534 counter_u64_free(rack_tlp_does_nada); 1535 COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE); 1536 COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE); 1537 } 1538 1539 static struct rack_sendmap * 1540 rack_alloc(struct tcp_rack *rack) 1541 { 1542 struct rack_sendmap *rsm; 1543 1544 rsm = uma_zalloc(rack_zone, M_NOWAIT); 1545 if (rsm) { 1546 rack->r_ctl.rc_num_maps_alloced++; 1547 counter_u64_add(rack_to_alloc, 1); 1548 return (rsm); 1549 } 1550 if (rack->rc_free_cnt) { 1551 counter_u64_add(rack_to_alloc_emerg, 1); 1552 rsm = TAILQ_FIRST(&rack->r_ctl.rc_free); 1553 TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext); 1554 rack->rc_free_cnt--; 1555 return (rsm); 1556 } 1557 return (NULL); 1558 } 1559 1560 static struct rack_sendmap * 1561 rack_alloc_full_limit(struct tcp_rack *rack) 1562 { 1563 if ((V_tcp_map_entries_limit > 0) && 1564 (rack->do_detection == 0) && 1565 (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) { 1566 counter_u64_add(rack_to_alloc_limited, 1); 1567 if (!rack->alloc_limit_reported) { 1568 rack->alloc_limit_reported = 1; 1569 counter_u64_add(rack_alloc_limited_conns, 1); 1570 } 1571 return (NULL); 1572 } 1573 return (rack_alloc(rack)); 1574 } 1575 1576 /* wrapper to allocate a sendmap entry, subject to a specific limit */ 1577 static struct rack_sendmap * 1578 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type) 1579 { 1580 struct rack_sendmap *rsm; 1581 1582 if (limit_type) { 1583 /* currently there is only one limit type */ 1584 if (V_tcp_map_split_limit > 0 && 1585 (rack->do_detection == 0) && 1586 rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) { 1587 counter_u64_add(rack_split_limited, 1); 1588 if (!rack->alloc_limit_reported) { 1589 rack->alloc_limit_reported = 1; 1590 counter_u64_add(rack_alloc_limited_conns, 1); 1591 } 1592 return (NULL); 1593 } 1594 } 1595 1596 /* allocate and mark in the limit type, if set */ 1597 rsm = rack_alloc(rack); 1598 if (rsm != NULL && limit_type) { 1599 rsm->r_limit_type = limit_type; 1600 rack->r_ctl.rc_num_split_allocs++; 1601 } 1602 return (rsm); 1603 } 1604 1605 static void 1606 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm) 1607 { 1608 if (rsm->r_limit_type) { 1609 /* currently there is only one limit type */ 1610 rack->r_ctl.rc_num_split_allocs--; 1611 } 1612 if (rack->r_ctl.rc_tlpsend == rsm) 1613 rack->r_ctl.rc_tlpsend = NULL; 1614 if (rack->r_ctl.rc_sacklast == rsm) 1615 rack->r_ctl.rc_sacklast = NULL; 1616 if (rack->rc_free_cnt < rack_free_cache) { 1617 memset(rsm, 0, sizeof(struct rack_sendmap)); 1618 TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext); 1619 rsm->r_limit_type = 0; 1620 rack->rc_free_cnt++; 1621 return; 1622 } 1623 rack->r_ctl.rc_num_maps_alloced--; 1624 uma_zfree(rack_zone, rsm); 1625 } 1626 1627 /* 1628 * CC wrapper hook functions 1629 */ 1630 static void 1631 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, struct tcphdr *th, uint16_t nsegs, 1632 uint16_t type, int32_t recovery) 1633 { 1634 #ifdef STATS 1635 int32_t gput; 1636 #endif 1637 1638 INP_WLOCK_ASSERT(tp->t_inpcb); 1639 tp->ccv->nsegs = nsegs; 1640 tp->ccv->bytes_this_ack = BYTES_THIS_ACK(tp, th); 1641 if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) { 1642 uint32_t max; 1643 1644 max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp); 1645 if (tp->ccv->bytes_this_ack > max) { 1646 tp->ccv->bytes_this_ack = max; 1647 } 1648 } 1649 if ((!V_tcp_do_newcwv && (tp->snd_cwnd <= tp->snd_wnd)) || 1650 (V_tcp_do_newcwv && (tp->snd_cwnd <= tp->snd_wnd) && 1651 (tp->snd_cwnd < (ctf_flight_size(tp, rack->r_ctl.rc_sacked) * 2)))) 1652 tp->ccv->flags |= CCF_CWND_LIMITED; 1653 else 1654 tp->ccv->flags &= ~CCF_CWND_LIMITED; 1655 1656 if (type == CC_ACK) { 1657 #ifdef STATS 1658 stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF, 1659 ((int32_t) tp->snd_cwnd) - tp->snd_wnd); 1660 if ((tp->t_flags & TF_GPUTINPROG) && 1661 SEQ_GEQ(th->th_ack, tp->gput_ack)) { 1662 gput = (((int64_t) (th->th_ack - tp->gput_seq)) << 3) / 1663 max(1, tcp_ts_getticks() - tp->gput_ts); 1664 /* We store it in bytes per ms (or kbytes per sec) */ 1665 rack->r_ctl.rc_gp_history[rack->r_ctl.rc_gp_hist_idx] = gput / 8; 1666 rack->r_ctl.rc_gp_hist_idx++; 1667 if (rack->r_ctl.rc_gp_hist_idx >= RACK_GP_HIST) 1668 rack->r_ctl.rc_gp_hist_filled = 1; 1669 rack->r_ctl.rc_gp_hist_idx %= RACK_GP_HIST; 1670 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT, 1671 gput); 1672 /* 1673 * XXXLAS: This is a temporary hack, and should be 1674 * chained off VOI_TCP_GPUT when stats(9) grows an 1675 * API to deal with chained VOIs. 1676 */ 1677 if (tp->t_stats_gput_prev > 0) 1678 stats_voi_update_abs_s32(tp->t_stats, 1679 VOI_TCP_GPUT_ND, 1680 ((gput - tp->t_stats_gput_prev) * 100) / 1681 tp->t_stats_gput_prev); 1682 tp->t_flags &= ~TF_GPUTINPROG; 1683 tp->t_stats_gput_prev = gput; 1684 #ifdef NETFLIX_PEAKRATE 1685 if (tp->t_maxpeakrate) { 1686 /* 1687 * We update t_peakrate_thr. This gives us roughly 1688 * one update per round trip time. 1689 */ 1690 tcp_update_peakrate_thr(tp); 1691 } 1692 #endif 1693 } 1694 #endif 1695 if (tp->snd_cwnd > tp->snd_ssthresh) { 1696 tp->t_bytes_acked += min(tp->ccv->bytes_this_ack, 1697 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp)); 1698 if (tp->t_bytes_acked >= tp->snd_cwnd) { 1699 tp->t_bytes_acked -= tp->snd_cwnd; 1700 tp->ccv->flags |= CCF_ABC_SENTAWND; 1701 } 1702 } else { 1703 tp->ccv->flags &= ~CCF_ABC_SENTAWND; 1704 tp->t_bytes_acked = 0; 1705 } 1706 } 1707 if (CC_ALGO(tp)->ack_received != NULL) { 1708 /* XXXLAS: Find a way to live without this */ 1709 tp->ccv->curack = th->th_ack; 1710 CC_ALGO(tp)->ack_received(tp->ccv, type); 1711 } 1712 #ifdef STATS 1713 stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, tp->snd_cwnd); 1714 #endif 1715 if (rack->r_ctl.rc_rack_largest_cwnd < tp->snd_cwnd) { 1716 rack->r_ctl.rc_rack_largest_cwnd = tp->snd_cwnd; 1717 } 1718 /* we enforce max peak rate if it is set. */ 1719 if (tp->t_peakrate_thr && tp->snd_cwnd > tp->t_peakrate_thr) { 1720 tp->snd_cwnd = tp->t_peakrate_thr; 1721 } 1722 } 1723 1724 static void 1725 tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th) 1726 { 1727 struct tcp_rack *rack; 1728 1729 rack = (struct tcp_rack *)tp->t_fb_ptr; 1730 INP_WLOCK_ASSERT(tp->t_inpcb); 1731 if (rack->r_ctl.rc_prr_sndcnt > 0) 1732 rack->r_wanted_output++; 1733 } 1734 1735 static void 1736 rack_post_recovery(struct tcpcb *tp, struct tcphdr *th) 1737 { 1738 struct tcp_rack *rack; 1739 1740 INP_WLOCK_ASSERT(tp->t_inpcb); 1741 rack = (struct tcp_rack *)tp->t_fb_ptr; 1742 if (CC_ALGO(tp)->post_recovery != NULL) { 1743 tp->ccv->curack = th->th_ack; 1744 CC_ALGO(tp)->post_recovery(tp->ccv); 1745 } 1746 /* 1747 * Here we can in theory adjust cwnd to be based on the number of 1748 * losses in the window (rack->r_ctl.rc_loss_count). This is done 1749 * based on the rack_use_proportional flag. 1750 */ 1751 if (rack->r_ctl.rc_prop_reduce && rack->r_ctl.rc_prop_rate) { 1752 int32_t reduce; 1753 1754 reduce = (rack->r_ctl.rc_loss_count * rack->r_ctl.rc_prop_rate); 1755 if (reduce > 50) { 1756 reduce = 50; 1757 } 1758 tp->snd_cwnd -= ((reduce * tp->snd_cwnd) / 100); 1759 } else { 1760 if (tp->snd_cwnd > tp->snd_ssthresh) { 1761 /* Drop us down to the ssthresh (1/2 cwnd at loss) */ 1762 tp->snd_cwnd = tp->snd_ssthresh; 1763 } 1764 } 1765 if (rack->r_ctl.rc_prr_sndcnt > 0) { 1766 /* Suck the next prr cnt back into cwnd */ 1767 tp->snd_cwnd += rack->r_ctl.rc_prr_sndcnt; 1768 rack->r_ctl.rc_prr_sndcnt = 0; 1769 rack_log_to_prr(rack, 1); 1770 } 1771 tp->snd_recover = tp->snd_una; 1772 EXIT_RECOVERY(tp->t_flags); 1773 1774 1775 } 1776 1777 static void 1778 rack_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type) 1779 { 1780 struct tcp_rack *rack; 1781 1782 INP_WLOCK_ASSERT(tp->t_inpcb); 1783 1784 rack = (struct tcp_rack *)tp->t_fb_ptr; 1785 switch (type) { 1786 case CC_NDUPACK: 1787 tp->t_flags &= ~TF_WASFRECOVERY; 1788 tp->t_flags &= ~TF_WASCRECOVERY; 1789 if (!IN_FASTRECOVERY(tp->t_flags)) { 1790 rack->r_ctl.rc_tlp_rtx_out = 0; 1791 rack->r_ctl.rc_prr_delivered = 0; 1792 rack->r_ctl.rc_prr_out = 0; 1793 rack->r_ctl.rc_loss_count = 0; 1794 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 1795 rack_log_to_prr(rack, 2); 1796 rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una; 1797 tp->snd_recover = tp->snd_max; 1798 if (tp->t_flags2 & TF2_ECN_PERMIT) 1799 tp->t_flags2 |= TF2_ECN_SND_CWR; 1800 } 1801 break; 1802 case CC_ECN: 1803 if (!IN_CONGRECOVERY(tp->t_flags)) { 1804 KMOD_TCPSTAT_INC(tcps_ecn_rcwnd); 1805 tp->snd_recover = tp->snd_max; 1806 if (tp->t_flags2 & TF2_ECN_PERMIT) 1807 tp->t_flags2 |= TF2_ECN_SND_CWR; 1808 } 1809 break; 1810 case CC_RTO: 1811 tp->t_dupacks = 0; 1812 tp->t_bytes_acked = 0; 1813 EXIT_RECOVERY(tp->t_flags); 1814 tp->snd_ssthresh = max(2, min(tp->snd_wnd, tp->snd_cwnd) / 2 / 1815 ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp); 1816 tp->snd_cwnd = ctf_fixed_maxseg(tp); 1817 if (tp->t_flags2 & TF2_ECN_PERMIT) 1818 tp->t_flags2 |= TF2_ECN_SND_CWR; 1819 break; 1820 case CC_RTO_ERR: 1821 KMOD_TCPSTAT_INC(tcps_sndrexmitbad); 1822 /* RTO was unnecessary, so reset everything. */ 1823 tp->snd_cwnd = tp->snd_cwnd_prev; 1824 tp->snd_ssthresh = tp->snd_ssthresh_prev; 1825 tp->snd_recover = tp->snd_recover_prev; 1826 if (tp->t_flags & TF_WASFRECOVERY) { 1827 ENTER_FASTRECOVERY(tp->t_flags); 1828 tp->t_flags &= ~TF_WASFRECOVERY; 1829 } 1830 if (tp->t_flags & TF_WASCRECOVERY) { 1831 ENTER_CONGRECOVERY(tp->t_flags); 1832 tp->t_flags &= ~TF_WASCRECOVERY; 1833 } 1834 tp->snd_nxt = tp->snd_max; 1835 tp->t_badrxtwin = 0; 1836 break; 1837 } 1838 1839 if (CC_ALGO(tp)->cong_signal != NULL) { 1840 if (th != NULL) 1841 tp->ccv->curack = th->th_ack; 1842 CC_ALGO(tp)->cong_signal(tp->ccv, type); 1843 } 1844 } 1845 1846 1847 1848 static inline void 1849 rack_cc_after_idle(struct tcpcb *tp) 1850 { 1851 uint32_t i_cwnd; 1852 1853 INP_WLOCK_ASSERT(tp->t_inpcb); 1854 1855 #ifdef NETFLIX_STATS 1856 KMOD_TCPSTAT_INC(tcps_idle_restarts); 1857 if (tp->t_state == TCPS_ESTABLISHED) 1858 KMOD_TCPSTAT_INC(tcps_idle_estrestarts); 1859 #endif 1860 if (CC_ALGO(tp)->after_idle != NULL) 1861 CC_ALGO(tp)->after_idle(tp->ccv); 1862 1863 if (tp->snd_cwnd == 1) 1864 i_cwnd = tp->t_maxseg; /* SYN(-ACK) lost */ 1865 else 1866 i_cwnd = tcp_compute_initwnd(tcp_maxseg(tp)); 1867 1868 /* 1869 * Being idle is no differnt than the initial window. If the cc 1870 * clamps it down below the initial window raise it to the initial 1871 * window. 1872 */ 1873 if (tp->snd_cwnd < i_cwnd) { 1874 tp->snd_cwnd = i_cwnd; 1875 } 1876 } 1877 1878 1879 /* 1880 * Indicate whether this ack should be delayed. We can delay the ack if 1881 * following conditions are met: 1882 * - There is no delayed ack timer in progress. 1883 * - Our last ack wasn't a 0-sized window. We never want to delay 1884 * the ack that opens up a 0-sized window. 1885 * - LRO wasn't used for this segment. We make sure by checking that the 1886 * segment size is not larger than the MSS. 1887 * - Delayed acks are enabled or this is a half-synchronized T/TCP 1888 * connection. 1889 */ 1890 #define DELAY_ACK(tp, tlen) \ 1891 (((tp->t_flags & TF_RXWIN0SENT) == 0) && \ 1892 ((tp->t_flags & TF_DELACK) == 0) && \ 1893 (tlen <= tp->t_maxseg) && \ 1894 (tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN))) 1895 1896 static struct rack_sendmap * 1897 rack_find_lowest_rsm(struct tcp_rack *rack) 1898 { 1899 struct rack_sendmap *rsm; 1900 1901 /* 1902 * Walk the time-order transmitted list looking for an rsm that is 1903 * not acked. This will be the one that was sent the longest time 1904 * ago that is still outstanding. 1905 */ 1906 TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) { 1907 if (rsm->r_flags & RACK_ACKED) { 1908 continue; 1909 } 1910 goto finish; 1911 } 1912 finish: 1913 return (rsm); 1914 } 1915 1916 static struct rack_sendmap * 1917 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm) 1918 { 1919 struct rack_sendmap *prsm; 1920 1921 /* 1922 * Walk the sequence order list backward until we hit and arrive at 1923 * the highest seq not acked. In theory when this is called it 1924 * should be the last segment (which it was not). 1925 */ 1926 counter_u64_add(rack_find_high, 1); 1927 prsm = rsm; 1928 RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) { 1929 if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) { 1930 continue; 1931 } 1932 return (prsm); 1933 } 1934 return (NULL); 1935 } 1936 1937 1938 static uint32_t 1939 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts) 1940 { 1941 int32_t lro; 1942 uint32_t thresh; 1943 1944 /* 1945 * lro is the flag we use to determine if we have seen reordering. 1946 * If it gets set we have seen reordering. The reorder logic either 1947 * works in one of two ways: 1948 * 1949 * If reorder-fade is configured, then we track the last time we saw 1950 * re-ordering occur. If we reach the point where enough time as 1951 * passed we no longer consider reordering has occuring. 1952 * 1953 * Or if reorder-face is 0, then once we see reordering we consider 1954 * the connection to alway be subject to reordering and just set lro 1955 * to 1. 1956 * 1957 * In the end if lro is non-zero we add the extra time for 1958 * reordering in. 1959 */ 1960 if (srtt == 0) 1961 srtt = 1; 1962 if (rack->r_ctl.rc_reorder_ts) { 1963 if (rack->r_ctl.rc_reorder_fade) { 1964 if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) { 1965 lro = cts - rack->r_ctl.rc_reorder_ts; 1966 if (lro == 0) { 1967 /* 1968 * No time as passed since the last 1969 * reorder, mark it as reordering. 1970 */ 1971 lro = 1; 1972 } 1973 } else { 1974 /* Negative time? */ 1975 lro = 0; 1976 } 1977 if (lro > rack->r_ctl.rc_reorder_fade) { 1978 /* Turn off reordering seen too */ 1979 rack->r_ctl.rc_reorder_ts = 0; 1980 lro = 0; 1981 } 1982 } else { 1983 /* Reodering does not fade */ 1984 lro = 1; 1985 } 1986 } else { 1987 lro = 0; 1988 } 1989 thresh = srtt + rack->r_ctl.rc_pkt_delay; 1990 if (lro) { 1991 /* It must be set, if not you get 1/4 rtt */ 1992 if (rack->r_ctl.rc_reorder_shift) 1993 thresh += (srtt >> rack->r_ctl.rc_reorder_shift); 1994 else 1995 thresh += (srtt >> 2); 1996 } else { 1997 thresh += 1; 1998 } 1999 /* We don't let the rack timeout be above a RTO */ 2000 if (thresh > TICKS_2_MSEC(rack->rc_tp->t_rxtcur)) { 2001 thresh = TICKS_2_MSEC(rack->rc_tp->t_rxtcur); 2002 } 2003 /* And we don't want it above the RTO max either */ 2004 if (thresh > rack_rto_max) { 2005 thresh = rack_rto_max; 2006 } 2007 return (thresh); 2008 } 2009 2010 static uint32_t 2011 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack, 2012 struct rack_sendmap *rsm, uint32_t srtt) 2013 { 2014 struct rack_sendmap *prsm; 2015 uint32_t thresh, len; 2016 int maxseg; 2017 2018 if (srtt == 0) 2019 srtt = 1; 2020 if (rack->r_ctl.rc_tlp_threshold) 2021 thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold); 2022 else 2023 thresh = (srtt * 2); 2024 2025 /* Get the previous sent packet, if any */ 2026 maxseg = ctf_fixed_maxseg(tp); 2027 counter_u64_add(rack_enter_tlp_calc, 1); 2028 len = rsm->r_end - rsm->r_start; 2029 if (rack->rack_tlp_threshold_use == TLP_USE_ID) { 2030 /* Exactly like the ID */ 2031 if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= maxseg) { 2032 uint32_t alt_thresh; 2033 /* 2034 * Compensate for delayed-ack with the d-ack time. 2035 */ 2036 counter_u64_add(rack_used_tlpmethod, 1); 2037 alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time; 2038 if (alt_thresh > thresh) 2039 thresh = alt_thresh; 2040 } 2041 } else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) { 2042 /* 2.1 behavior */ 2043 prsm = TAILQ_PREV(rsm, rack_head, r_tnext); 2044 if (prsm && (len <= maxseg)) { 2045 /* 2046 * Two packets outstanding, thresh should be (2*srtt) + 2047 * possible inter-packet delay (if any). 2048 */ 2049 uint32_t inter_gap = 0; 2050 int idx, nidx; 2051 2052 counter_u64_add(rack_used_tlpmethod, 1); 2053 idx = rsm->r_rtr_cnt - 1; 2054 nidx = prsm->r_rtr_cnt - 1; 2055 if (TSTMP_GEQ(rsm->r_tim_lastsent[nidx], prsm->r_tim_lastsent[idx])) { 2056 /* Yes it was sent later (or at the same time) */ 2057 inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx]; 2058 } 2059 thresh += inter_gap; 2060 } else if (len <= maxseg) { 2061 /* 2062 * Possibly compensate for delayed-ack. 2063 */ 2064 uint32_t alt_thresh; 2065 2066 counter_u64_add(rack_used_tlpmethod2, 1); 2067 alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time; 2068 if (alt_thresh > thresh) 2069 thresh = alt_thresh; 2070 } 2071 } else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) { 2072 /* 2.2 behavior */ 2073 if (len <= maxseg) { 2074 uint32_t alt_thresh; 2075 /* 2076 * Compensate for delayed-ack with the d-ack time. 2077 */ 2078 counter_u64_add(rack_used_tlpmethod, 1); 2079 alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time; 2080 if (alt_thresh > thresh) 2081 thresh = alt_thresh; 2082 } 2083 } 2084 /* Not above an RTO */ 2085 if (thresh > TICKS_2_MSEC(tp->t_rxtcur)) { 2086 thresh = TICKS_2_MSEC(tp->t_rxtcur); 2087 } 2088 /* Not above a RTO max */ 2089 if (thresh > rack_rto_max) { 2090 thresh = rack_rto_max; 2091 } 2092 /* Apply user supplied min TLP */ 2093 if (thresh < rack_tlp_min) { 2094 thresh = rack_tlp_min; 2095 } 2096 return (thresh); 2097 } 2098 2099 static uint32_t 2100 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack) 2101 { 2102 /* 2103 * We want the rack_rtt which is the 2104 * last rtt we measured. However if that 2105 * does not exist we fallback to the srtt (which 2106 * we probably will never do) and then as a last 2107 * resort we use RACK_INITIAL_RTO if no srtt is 2108 * yet set. 2109 */ 2110 if (rack->rc_rack_rtt) 2111 return(rack->rc_rack_rtt); 2112 else if (tp->t_srtt == 0) 2113 return(RACK_INITIAL_RTO); 2114 return (TICKS_2_MSEC(tp->t_srtt >> TCP_RTT_SHIFT)); 2115 } 2116 2117 static struct rack_sendmap * 2118 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused) 2119 { 2120 /* 2121 * Check to see that we don't need to fall into recovery. We will 2122 * need to do so if our oldest transmit is past the time we should 2123 * have had an ack. 2124 */ 2125 struct tcp_rack *rack; 2126 struct rack_sendmap *rsm; 2127 int32_t idx; 2128 uint32_t srtt, thresh; 2129 2130 rack = (struct tcp_rack *)tp->t_fb_ptr; 2131 if (RB_EMPTY(&rack->r_ctl.rc_mtree)) { 2132 return (NULL); 2133 } 2134 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 2135 if (rsm == NULL) 2136 return (NULL); 2137 2138 if (rsm->r_flags & RACK_ACKED) { 2139 rsm = rack_find_lowest_rsm(rack); 2140 if (rsm == NULL) 2141 return (NULL); 2142 } 2143 idx = rsm->r_rtr_cnt - 1; 2144 srtt = rack_grab_rtt(tp, rack); 2145 thresh = rack_calc_thresh_rack(rack, srtt, tsused); 2146 if (tsused < rsm->r_tim_lastsent[idx]) { 2147 return (NULL); 2148 } 2149 if ((tsused - rsm->r_tim_lastsent[idx]) < thresh) { 2150 return (NULL); 2151 } 2152 /* Ok if we reach here we are over-due */ 2153 rack->r_ctl.rc_rsm_start = rsm->r_start; 2154 rack->r_ctl.rc_cwnd_at = tp->snd_cwnd; 2155 rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh; 2156 rack_cong_signal(tp, NULL, CC_NDUPACK); 2157 return (rsm); 2158 } 2159 2160 static uint32_t 2161 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack) 2162 { 2163 int32_t t; 2164 int32_t tt; 2165 uint32_t ret_val; 2166 2167 t = TICKS_2_MSEC((tp->t_srtt >> TCP_RTT_SHIFT) + ((tp->t_rttvar * 4) >> TCP_RTT_SHIFT)); 2168 TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift], 2169 rack_persist_min, rack_persist_max); 2170 if (tp->t_rxtshift < TCP_MAXRXTSHIFT) 2171 tp->t_rxtshift++; 2172 rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT; 2173 ret_val = (uint32_t)tt; 2174 return (ret_val); 2175 } 2176 2177 static uint32_t 2178 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack) 2179 { 2180 /* 2181 * Start the FR timer, we do this based on getting the first one in 2182 * the rc_tmap. Note that if its NULL we must stop the timer. in all 2183 * events we need to stop the running timer (if its running) before 2184 * starting the new one. 2185 */ 2186 uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse; 2187 uint32_t srtt_cur; 2188 int32_t idx; 2189 int32_t is_tlp_timer = 0; 2190 struct rack_sendmap *rsm; 2191 2192 if (rack->t_timers_stopped) { 2193 /* All timers have been stopped none are to run */ 2194 return (0); 2195 } 2196 if (rack->rc_in_persist) { 2197 /* We can't start any timer in persists */ 2198 return (rack_get_persists_timer_val(tp, rack)); 2199 } 2200 if ((tp->t_state < TCPS_ESTABLISHED) || 2201 ((tp->t_flags & TF_SACK_PERMIT) == 0)) 2202 goto activate_rxt; 2203 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 2204 if ((rsm == NULL) || sup_rack) { 2205 /* Nothing on the send map */ 2206 activate_rxt: 2207 time_since_sent = 0; 2208 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 2209 if (rsm) { 2210 idx = rsm->r_rtr_cnt - 1; 2211 if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], rack->r_ctl.rc_tlp_rxt_last_time)) 2212 tstmp_touse = rsm->r_tim_lastsent[idx]; 2213 else 2214 tstmp_touse = rack->r_ctl.rc_tlp_rxt_last_time; 2215 if (TSTMP_GT(tstmp_touse, cts)) 2216 time_since_sent = cts - tstmp_touse; 2217 } 2218 if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) { 2219 rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT; 2220 to = TICKS_2_MSEC(tp->t_rxtcur); 2221 if (to > time_since_sent) 2222 to -= time_since_sent; 2223 else 2224 to = rack->r_ctl.rc_min_to; 2225 if (to == 0) 2226 to = 1; 2227 return (to); 2228 } 2229 return (0); 2230 } 2231 if (rsm->r_flags & RACK_ACKED) { 2232 rsm = rack_find_lowest_rsm(rack); 2233 if (rsm == NULL) { 2234 /* No lowest? */ 2235 goto activate_rxt; 2236 } 2237 } 2238 if (rack->sack_attack_disable) { 2239 /* 2240 * We don't want to do 2241 * any TLP's if you are an attacker. 2242 * Though if you are doing what 2243 * is expected you may still have 2244 * SACK-PASSED marks. 2245 */ 2246 goto activate_rxt; 2247 } 2248 /* Convert from ms to usecs */ 2249 if (rsm->r_flags & RACK_SACK_PASSED) { 2250 if ((tp->t_flags & TF_SENTFIN) && 2251 ((tp->snd_max - tp->snd_una) == 1) && 2252 (rsm->r_flags & RACK_HAS_FIN)) { 2253 /* 2254 * We don't start a rack timer if all we have is a 2255 * FIN outstanding. 2256 */ 2257 goto activate_rxt; 2258 } 2259 if ((rack->use_rack_cheat == 0) && 2260 (IN_RECOVERY(tp->t_flags)) && 2261 (rack->r_ctl.rc_prr_sndcnt < ctf_fixed_maxseg(tp))) { 2262 /* 2263 * We are not cheating, in recovery and 2264 * not enough ack's to yet get our next 2265 * retransmission out. 2266 * 2267 * Note that classified attackers do not 2268 * get to use the rack-cheat. 2269 */ 2270 goto activate_tlp; 2271 } 2272 srtt = rack_grab_rtt(tp, rack); 2273 thresh = rack_calc_thresh_rack(rack, srtt, cts); 2274 idx = rsm->r_rtr_cnt - 1; 2275 exp = rsm->r_tim_lastsent[idx] + thresh; 2276 if (SEQ_GEQ(exp, cts)) { 2277 to = exp - cts; 2278 if (to < rack->r_ctl.rc_min_to) { 2279 to = rack->r_ctl.rc_min_to; 2280 } 2281 } else { 2282 to = rack->r_ctl.rc_min_to; 2283 } 2284 } else { 2285 /* Ok we need to do a TLP not RACK */ 2286 activate_tlp: 2287 if ((rack->rc_tlp_in_progress != 0) || 2288 (rack->r_ctl.rc_tlp_rtx_out != 0)) { 2289 /* 2290 * The previous send was a TLP or a tlp_rtx is in 2291 * process. 2292 */ 2293 goto activate_rxt; 2294 } 2295 rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext); 2296 if (rsm == NULL) { 2297 /* We found no rsm to TLP with. */ 2298 goto activate_rxt; 2299 } 2300 if (rsm->r_flags & RACK_HAS_FIN) { 2301 /* If its a FIN we dont do TLP */ 2302 rsm = NULL; 2303 goto activate_rxt; 2304 } 2305 idx = rsm->r_rtr_cnt - 1; 2306 time_since_sent = 0; 2307 if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], rack->r_ctl.rc_tlp_rxt_last_time)) 2308 tstmp_touse = rsm->r_tim_lastsent[idx]; 2309 else 2310 tstmp_touse = rack->r_ctl.rc_tlp_rxt_last_time; 2311 if (TSTMP_GT(tstmp_touse, cts)) 2312 time_since_sent = cts - tstmp_touse; 2313 is_tlp_timer = 1; 2314 if (tp->t_srtt) { 2315 srtt_cur = (tp->t_srtt >> TCP_RTT_SHIFT); 2316 srtt = TICKS_2_MSEC(srtt_cur); 2317 } else 2318 srtt = RACK_INITIAL_RTO; 2319 thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt); 2320 if (thresh > time_since_sent) 2321 to = thresh - time_since_sent; 2322 else 2323 to = rack->r_ctl.rc_min_to; 2324 if (to > TCPTV_REXMTMAX) { 2325 /* 2326 * If the TLP time works out to larger than the max 2327 * RTO lets not do TLP.. just RTO. 2328 */ 2329 goto activate_rxt; 2330 } 2331 if (rsm->r_start != rack->r_ctl.rc_last_tlp_seq) { 2332 /* 2333 * The tail is no longer the last one I did a probe 2334 * on 2335 */ 2336 rack->r_ctl.rc_tlp_seg_send_cnt = 0; 2337 rack->r_ctl.rc_last_tlp_seq = rsm->r_start; 2338 } 2339 } 2340 if (is_tlp_timer == 0) { 2341 rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK; 2342 } else { 2343 if ((rack->r_ctl.rc_tlp_send_cnt > rack_tlp_max_resend) || 2344 (rack->r_ctl.rc_tlp_seg_send_cnt > rack_tlp_max_resend)) { 2345 /* 2346 * We have exceeded how many times we can retran the 2347 * current TLP timer, switch to the RTO timer. 2348 */ 2349 goto activate_rxt; 2350 } else { 2351 rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP; 2352 } 2353 } 2354 if (to == 0) 2355 to = 1; 2356 return (to); 2357 } 2358 2359 static void 2360 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 2361 { 2362 if (rack->rc_in_persist == 0) { 2363 rack->r_ctl.rc_went_idle_time = cts; 2364 rack_timer_cancel(tp, rack, cts, __LINE__); 2365 tp->t_rxtshift = 0; 2366 rack->rc_in_persist = 1; 2367 } 2368 } 2369 2370 static void 2371 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack) 2372 { 2373 if (rack->rc_inp->inp_in_hpts) { 2374 tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT); 2375 rack->r_ctl.rc_hpts_flags = 0; 2376 } 2377 rack->rc_in_persist = 0; 2378 rack->r_ctl.rc_went_idle_time = 0; 2379 tp->t_flags &= ~TF_FORCEDATA; 2380 tp->t_rxtshift = 0; 2381 } 2382 2383 static void 2384 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts, 2385 int32_t slot, uint32_t tot_len_this_send, int sup_rack) 2386 { 2387 struct inpcb *inp; 2388 uint32_t delayed_ack = 0; 2389 uint32_t hpts_timeout; 2390 uint8_t stopped; 2391 uint32_t left = 0; 2392 2393 inp = tp->t_inpcb; 2394 if (inp->inp_in_hpts) { 2395 /* A previous call is already set up */ 2396 return; 2397 } 2398 if ((tp->t_state == TCPS_CLOSED) || 2399 (tp->t_state == TCPS_LISTEN)) { 2400 return; 2401 } 2402 stopped = rack->rc_tmr_stopped; 2403 if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) { 2404 left = rack->r_ctl.rc_timer_exp - cts; 2405 } 2406 rack->tlp_timer_up = 0; 2407 rack->r_ctl.rc_timer_exp = 0; 2408 if (rack->rc_inp->inp_in_hpts == 0) { 2409 rack->r_ctl.rc_hpts_flags = 0; 2410 } 2411 if (slot) { 2412 /* We are hptsi too */ 2413 rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT; 2414 } else if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) { 2415 /* 2416 * We are still left on the hpts when the to goes 2417 * it will be for output. 2418 */ 2419 if (TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) 2420 slot = rack->r_ctl.rc_last_output_to - cts; 2421 else 2422 slot = 1; 2423 } 2424 hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack); 2425 #ifdef NETFLIX_EXP_DETECTION 2426 if (rack->sack_attack_disable && 2427 (slot < USEC_TO_MSEC(tcp_sad_pacing_interval))) { 2428 /* 2429 * We have a potential attacker on 2430 * the line. We have possibly some 2431 * (or now) pacing time set. We want to 2432 * slow down the processing of sacks by some 2433 * amount (if it is an attacker). Set the default 2434 * slot for attackers in place (unless the orginal 2435 * interval is longer). Its stored in 2436 * micro-seconds, so lets convert to msecs. 2437 */ 2438 slot = USEC_TO_MSEC(tcp_sad_pacing_interval); 2439 } 2440 #endif 2441 if (tp->t_flags & TF_DELACK) { 2442 delayed_ack = TICKS_2_MSEC(tcp_delacktime); 2443 rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK; 2444 } 2445 if (delayed_ack && ((hpts_timeout == 0) || 2446 (delayed_ack < hpts_timeout))) 2447 hpts_timeout = delayed_ack; 2448 else 2449 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK; 2450 /* 2451 * If no timers are going to run and we will fall off the hptsi 2452 * wheel, we resort to a keep-alive timer if its configured. 2453 */ 2454 if ((hpts_timeout == 0) && 2455 (slot == 0)) { 2456 if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) && 2457 (tp->t_state <= TCPS_CLOSING)) { 2458 /* 2459 * Ok we have no timer (persists, rack, tlp, rxt or 2460 * del-ack), we don't have segments being paced. So 2461 * all that is left is the keepalive timer. 2462 */ 2463 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2464 /* Get the established keep-alive time */ 2465 hpts_timeout = TP_KEEPIDLE(tp); 2466 } else { 2467 /* Get the initial setup keep-alive time */ 2468 hpts_timeout = TP_KEEPINIT(tp); 2469 } 2470 rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP; 2471 } 2472 } 2473 if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) == 2474 (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) { 2475 /* 2476 * RACK, TLP, persists and RXT timers all are restartable 2477 * based on actions input .. i.e we received a packet (ack 2478 * or sack) and that changes things (rw, or snd_una etc). 2479 * Thus we can restart them with a new value. For 2480 * keep-alive, delayed_ack we keep track of what was left 2481 * and restart the timer with a smaller value. 2482 */ 2483 if (left < hpts_timeout) 2484 hpts_timeout = left; 2485 } 2486 if (hpts_timeout) { 2487 /* 2488 * Hack alert for now we can't time-out over 2,147,483 2489 * seconds (a bit more than 596 hours), which is probably ok 2490 * :). 2491 */ 2492 if (hpts_timeout > 0x7ffffffe) 2493 hpts_timeout = 0x7ffffffe; 2494 rack->r_ctl.rc_timer_exp = cts + hpts_timeout; 2495 } 2496 if (slot) { 2497 rack->rc_inp->inp_flags2 |= INP_MBUF_QUEUE_READY; 2498 if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) 2499 inp->inp_flags2 |= INP_DONT_SACK_QUEUE; 2500 else 2501 inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE; 2502 rack->r_ctl.rc_last_output_to = cts + slot; 2503 if ((hpts_timeout == 0) || (hpts_timeout > slot)) { 2504 if (rack->rc_inp->inp_in_hpts == 0) 2505 tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(slot)); 2506 rack_log_to_start(rack, cts, hpts_timeout, slot, 1); 2507 } else { 2508 /* 2509 * Arrange for the hpts to kick back in after the 2510 * t-o if the t-o does not cause a send. 2511 */ 2512 if (rack->rc_inp->inp_in_hpts == 0) 2513 tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout)); 2514 rack_log_to_start(rack, cts, hpts_timeout, slot, 0); 2515 } 2516 } else if (hpts_timeout) { 2517 if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) { 2518 /* For a rack timer, don't wake us */ 2519 rack->rc_inp->inp_flags2 |= INP_MBUF_QUEUE_READY; 2520 inp->inp_flags2 |= INP_DONT_SACK_QUEUE; 2521 } else { 2522 /* All other timers wake us up */ 2523 rack->rc_inp->inp_flags2 &= ~INP_MBUF_QUEUE_READY; 2524 inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE; 2525 } 2526 if (rack->rc_inp->inp_in_hpts == 0) 2527 tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout)); 2528 rack_log_to_start(rack, cts, hpts_timeout, slot, 0); 2529 } else { 2530 /* No timer starting */ 2531 #ifdef INVARIANTS 2532 if (SEQ_GT(tp->snd_max, tp->snd_una)) { 2533 panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?", 2534 tp, rack, tot_len_this_send, cts, slot, hpts_timeout); 2535 } 2536 #endif 2537 } 2538 rack->rc_tmr_stopped = 0; 2539 if (slot) 2540 rack_log_type_bbrsnd(rack, tot_len_this_send, slot, cts); 2541 } 2542 2543 /* 2544 * RACK Timer, here we simply do logging and house keeping. 2545 * the normal rack_output() function will call the 2546 * appropriate thing to check if we need to do a RACK retransmit. 2547 * We return 1, saying don't proceed with rack_output only 2548 * when all timers have been stopped (destroyed PCB?). 2549 */ 2550 static int 2551 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 2552 { 2553 /* 2554 * This timer simply provides an internal trigger to send out data. 2555 * The check_recovery_mode call will see if there are needed 2556 * retransmissions, if so we will enter fast-recovery. The output 2557 * call may or may not do the same thing depending on sysctl 2558 * settings. 2559 */ 2560 struct rack_sendmap *rsm; 2561 int32_t recovery, ll; 2562 2563 if (tp->t_timers->tt_flags & TT_STOPPED) { 2564 return (1); 2565 } 2566 if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) { 2567 /* Its not time yet */ 2568 return (0); 2569 } 2570 recovery = IN_RECOVERY(tp->t_flags); 2571 counter_u64_add(rack_to_tot, 1); 2572 if (rack->r_state && (rack->r_state != tp->t_state)) 2573 rack_set_state(tp, rack); 2574 rsm = rack_check_recovery_mode(tp, cts); 2575 if (rsm) 2576 ll = rsm->r_end - rsm->r_start; 2577 else 2578 ll = 0; 2579 rack_log_to_event(rack, RACK_TO_FRM_RACK, ll); 2580 if (rsm) { 2581 uint32_t rtt; 2582 2583 rtt = rack->rc_rack_rtt; 2584 if (rtt == 0) 2585 rtt = 1; 2586 if ((recovery == 0) && 2587 (rack->r_ctl.rc_prr_sndcnt < ctf_fixed_maxseg(tp))) { 2588 /* 2589 * The rack-timeout that enter's us into recovery 2590 * will force out one MSS and set us up so that we 2591 * can do one more send in 2*rtt (transitioning the 2592 * rack timeout into a rack-tlp). 2593 */ 2594 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 2595 rack_log_to_prr(rack, 3); 2596 } else if ((rack->r_ctl.rc_prr_sndcnt < (rsm->r_end - rsm->r_start)) && 2597 rack->use_rack_cheat) { 2598 /* 2599 * When a rack timer goes, if the rack cheat is 2600 * on, arrange it so we can send a full segment. 2601 */ 2602 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 2603 rack_log_to_prr(rack, 4); 2604 } 2605 } else { 2606 /* This is a case that should happen rarely if ever */ 2607 counter_u64_add(rack_tlp_does_nada, 1); 2608 #ifdef TCP_BLACKBOX 2609 tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true); 2610 #endif 2611 rack->r_ctl.rc_resend = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 2612 } 2613 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK; 2614 return (0); 2615 } 2616 2617 static __inline void 2618 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm, 2619 struct rack_sendmap *rsm, uint32_t start) 2620 { 2621 int idx; 2622 2623 nrsm->r_start = start; 2624 nrsm->r_end = rsm->r_end; 2625 nrsm->r_rtr_cnt = rsm->r_rtr_cnt; 2626 nrsm->r_flags = rsm->r_flags; 2627 nrsm->r_dupack = rsm->r_dupack; 2628 nrsm->r_rtr_bytes = 0; 2629 rsm->r_end = nrsm->r_start; 2630 for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) { 2631 nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx]; 2632 } 2633 } 2634 2635 static struct rack_sendmap * 2636 rack_merge_rsm(struct tcp_rack *rack, 2637 struct rack_sendmap *l_rsm, 2638 struct rack_sendmap *r_rsm) 2639 { 2640 /* 2641 * We are merging two ack'd RSM's, 2642 * the l_rsm is on the left (lower seq 2643 * values) and the r_rsm is on the right 2644 * (higher seq value). The simplest way 2645 * to merge these is to move the right 2646 * one into the left. I don't think there 2647 * is any reason we need to try to find 2648 * the oldest (or last oldest retransmitted). 2649 */ 2650 struct rack_sendmap *rm; 2651 2652 l_rsm->r_end = r_rsm->r_end; 2653 if (l_rsm->r_dupack < r_rsm->r_dupack) 2654 l_rsm->r_dupack = r_rsm->r_dupack; 2655 if (r_rsm->r_rtr_bytes) 2656 l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes; 2657 if (r_rsm->r_in_tmap) { 2658 /* This really should not happen */ 2659 TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext); 2660 r_rsm->r_in_tmap = 0; 2661 } 2662 /* Now the flags */ 2663 if (r_rsm->r_flags & RACK_HAS_FIN) 2664 l_rsm->r_flags |= RACK_HAS_FIN; 2665 if (r_rsm->r_flags & RACK_TLP) 2666 l_rsm->r_flags |= RACK_TLP; 2667 if (r_rsm->r_flags & RACK_RWND_COLLAPSED) 2668 l_rsm->r_flags |= RACK_RWND_COLLAPSED; 2669 rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm); 2670 #ifdef INVARIANTS 2671 if (rm != r_rsm) { 2672 panic("removing head in rack:%p rsm:%p rm:%p", 2673 rack, r_rsm, rm); 2674 } 2675 #endif 2676 if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) { 2677 /* Transfer the split limit to the map we free */ 2678 r_rsm->r_limit_type = l_rsm->r_limit_type; 2679 l_rsm->r_limit_type = 0; 2680 } 2681 rack_free(rack, r_rsm); 2682 return(l_rsm); 2683 } 2684 2685 /* 2686 * TLP Timer, here we simply setup what segment we want to 2687 * have the TLP expire on, the normal rack_output() will then 2688 * send it out. 2689 * 2690 * We return 1, saying don't proceed with rack_output only 2691 * when all timers have been stopped (destroyed PCB?). 2692 */ 2693 static int 2694 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 2695 { 2696 /* 2697 * Tail Loss Probe. 2698 */ 2699 struct rack_sendmap *rsm = NULL; 2700 struct rack_sendmap *insret; 2701 struct socket *so; 2702 uint32_t amm, old_prr_snd = 0; 2703 uint32_t out, avail; 2704 int collapsed_win = 0; 2705 2706 if (tp->t_timers->tt_flags & TT_STOPPED) { 2707 return (1); 2708 } 2709 if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) { 2710 /* Its not time yet */ 2711 return (0); 2712 } 2713 if (rack_progress_timeout_check(tp)) { 2714 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 2715 return (1); 2716 } 2717 /* 2718 * A TLP timer has expired. We have been idle for 2 rtts. So we now 2719 * need to figure out how to force a full MSS segment out. 2720 */ 2721 rack_log_to_event(rack, RACK_TO_FRM_TLP, 0); 2722 counter_u64_add(rack_tlp_tot, 1); 2723 if (rack->r_state && (rack->r_state != tp->t_state)) 2724 rack_set_state(tp, rack); 2725 so = tp->t_inpcb->inp_socket; 2726 #ifdef KERN_TLS 2727 if (rack->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) { 2728 /* 2729 * For hardware TLS we do *not* want to send 2730 * new data, lets instead just do a retransmission. 2731 */ 2732 goto need_retran; 2733 } 2734 #endif 2735 avail = sbavail(&so->so_snd); 2736 out = tp->snd_max - tp->snd_una; 2737 rack->tlp_timer_up = 1; 2738 if (out > tp->snd_wnd) { 2739 /* special case, we need a retransmission */ 2740 collapsed_win = 1; 2741 goto need_retran; 2742 } 2743 /* 2744 * If we are in recovery we can jazz out a segment if new data is 2745 * present simply by setting rc_prr_sndcnt to a segment. 2746 */ 2747 if ((avail > out) && 2748 ((rack_always_send_oldest == 0) || (TAILQ_EMPTY(&rack->r_ctl.rc_tmap)))) { 2749 /* New data is available */ 2750 amm = avail - out; 2751 if (amm > ctf_fixed_maxseg(tp)) { 2752 amm = ctf_fixed_maxseg(tp); 2753 } else if ((amm < ctf_fixed_maxseg(tp)) && ((tp->t_flags & TF_NODELAY) == 0)) { 2754 /* not enough to fill a MTU and no-delay is off */ 2755 goto need_retran; 2756 } 2757 if (IN_RECOVERY(tp->t_flags)) { 2758 /* Unlikely */ 2759 old_prr_snd = rack->r_ctl.rc_prr_sndcnt; 2760 if (out + amm <= tp->snd_wnd) { 2761 rack->r_ctl.rc_prr_sndcnt = amm; 2762 rack_log_to_prr(rack, 4); 2763 } else 2764 goto need_retran; 2765 } else { 2766 /* Set the send-new override */ 2767 if (out + amm <= tp->snd_wnd) 2768 rack->r_ctl.rc_tlp_new_data = amm; 2769 else 2770 goto need_retran; 2771 } 2772 rack->r_ctl.rc_tlp_seg_send_cnt = 0; 2773 rack->r_ctl.rc_last_tlp_seq = tp->snd_max; 2774 rack->r_ctl.rc_tlpsend = NULL; 2775 counter_u64_add(rack_tlp_newdata, 1); 2776 goto send; 2777 } 2778 need_retran: 2779 /* 2780 * Ok we need to arrange the last un-acked segment to be re-sent, or 2781 * optionally the first un-acked segment. 2782 */ 2783 if (collapsed_win == 0) { 2784 if (rack_always_send_oldest) 2785 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 2786 else { 2787 rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 2788 if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) { 2789 rsm = rack_find_high_nonack(rack, rsm); 2790 } 2791 } 2792 if (rsm == NULL) { 2793 counter_u64_add(rack_tlp_does_nada, 1); 2794 #ifdef TCP_BLACKBOX 2795 tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true); 2796 #endif 2797 goto out; 2798 } 2799 } else { 2800 /* 2801 * We must find the last segment 2802 * that was acceptable by the client. 2803 */ 2804 RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) { 2805 if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) { 2806 /* Found one */ 2807 break; 2808 } 2809 } 2810 if (rsm == NULL) { 2811 /* None? if so send the first */ 2812 rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 2813 if (rsm == NULL) { 2814 counter_u64_add(rack_tlp_does_nada, 1); 2815 #ifdef TCP_BLACKBOX 2816 tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true); 2817 #endif 2818 goto out; 2819 } 2820 } 2821 } 2822 if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) { 2823 /* 2824 * We need to split this the last segment in two. 2825 */ 2826 struct rack_sendmap *nrsm; 2827 2828 2829 nrsm = rack_alloc_full_limit(rack); 2830 if (nrsm == NULL) { 2831 /* 2832 * No memory to split, we will just exit and punt 2833 * off to the RXT timer. 2834 */ 2835 counter_u64_add(rack_tlp_does_nada, 1); 2836 goto out; 2837 } 2838 rack_clone_rsm(rack, nrsm, rsm, 2839 (rsm->r_end - ctf_fixed_maxseg(tp))); 2840 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 2841 #ifdef INVARIANTS 2842 if (insret != NULL) { 2843 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 2844 nrsm, insret, rack, rsm); 2845 } 2846 #endif 2847 if (rsm->r_in_tmap) { 2848 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 2849 nrsm->r_in_tmap = 1; 2850 } 2851 rsm->r_flags &= (~RACK_HAS_FIN); 2852 rsm = nrsm; 2853 } 2854 rack->r_ctl.rc_tlpsend = rsm; 2855 rack->r_ctl.rc_tlp_rtx_out = 1; 2856 if (rsm->r_start == rack->r_ctl.rc_last_tlp_seq) { 2857 rack->r_ctl.rc_tlp_seg_send_cnt++; 2858 tp->t_rxtshift++; 2859 } else { 2860 rack->r_ctl.rc_last_tlp_seq = rsm->r_start; 2861 rack->r_ctl.rc_tlp_seg_send_cnt = 1; 2862 } 2863 send: 2864 rack->r_ctl.rc_tlp_send_cnt++; 2865 if (rack->r_ctl.rc_tlp_send_cnt > rack_tlp_max_resend) { 2866 /* 2867 * Can't [re]/transmit a segment we have not heard from the 2868 * peer in max times. We need the retransmit timer to take 2869 * over. 2870 */ 2871 restore: 2872 rack->r_ctl.rc_tlpsend = NULL; 2873 if (rsm) 2874 rsm->r_flags &= ~RACK_TLP; 2875 rack->r_ctl.rc_prr_sndcnt = old_prr_snd; 2876 rack_log_to_prr(rack, 5); 2877 counter_u64_add(rack_tlp_retran_fail, 1); 2878 goto out; 2879 } else if (rsm) { 2880 rsm->r_flags |= RACK_TLP; 2881 } 2882 if (rsm && (rsm->r_start == rack->r_ctl.rc_last_tlp_seq) && 2883 (rack->r_ctl.rc_tlp_seg_send_cnt > rack_tlp_max_resend)) { 2884 /* 2885 * We don't want to send a single segment more than the max 2886 * either. 2887 */ 2888 goto restore; 2889 } 2890 rack->r_timer_override = 1; 2891 rack->r_tlp_running = 1; 2892 rack->rc_tlp_in_progress = 1; 2893 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP; 2894 return (0); 2895 out: 2896 rack->tlp_timer_up = 0; 2897 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP; 2898 return (0); 2899 } 2900 2901 /* 2902 * Delayed ack Timer, here we simply need to setup the 2903 * ACK_NOW flag and remove the DELACK flag. From there 2904 * the output routine will send the ack out. 2905 * 2906 * We only return 1, saying don't proceed, if all timers 2907 * are stopped (destroyed PCB?). 2908 */ 2909 static int 2910 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 2911 { 2912 if (tp->t_timers->tt_flags & TT_STOPPED) { 2913 return (1); 2914 } 2915 rack_log_to_event(rack, RACK_TO_FRM_DELACK, 0); 2916 tp->t_flags &= ~TF_DELACK; 2917 tp->t_flags |= TF_ACKNOW; 2918 KMOD_TCPSTAT_INC(tcps_delack); 2919 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK; 2920 return (0); 2921 } 2922 2923 /* 2924 * Persists timer, here we simply need to setup the 2925 * FORCE-DATA flag the output routine will send 2926 * the one byte send. 2927 * 2928 * We only return 1, saying don't proceed, if all timers 2929 * are stopped (destroyed PCB?). 2930 */ 2931 static int 2932 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 2933 { 2934 struct tcptemp *t_template; 2935 struct inpcb *inp; 2936 int32_t retval = 1; 2937 2938 inp = tp->t_inpcb; 2939 2940 if (tp->t_timers->tt_flags & TT_STOPPED) { 2941 return (1); 2942 } 2943 if (rack->rc_in_persist == 0) 2944 return (0); 2945 if (rack_progress_timeout_check(tp)) { 2946 tcp_set_inp_to_drop(inp, ETIMEDOUT); 2947 return (1); 2948 } 2949 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp)); 2950 /* 2951 * Persistence timer into zero window. Force a byte to be output, if 2952 * possible. 2953 */ 2954 KMOD_TCPSTAT_INC(tcps_persisttimeo); 2955 /* 2956 * Hack: if the peer is dead/unreachable, we do not time out if the 2957 * window is closed. After a full backoff, drop the connection if 2958 * the idle time (no responses to probes) reaches the maximum 2959 * backoff that we would use if retransmitting. 2960 */ 2961 if (tp->t_rxtshift == TCP_MAXRXTSHIFT && 2962 (ticks - tp->t_rcvtime >= tcp_maxpersistidle || 2963 ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) { 2964 KMOD_TCPSTAT_INC(tcps_persistdrop); 2965 retval = 1; 2966 tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT); 2967 goto out; 2968 } 2969 if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) && 2970 tp->snd_una == tp->snd_max) 2971 rack_exit_persist(tp, rack); 2972 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT; 2973 /* 2974 * If the user has closed the socket then drop a persisting 2975 * connection after a much reduced timeout. 2976 */ 2977 if (tp->t_state > TCPS_CLOSE_WAIT && 2978 (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) { 2979 retval = 1; 2980 KMOD_TCPSTAT_INC(tcps_persistdrop); 2981 tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT); 2982 goto out; 2983 } 2984 t_template = tcpip_maketemplate(rack->rc_inp); 2985 if (t_template) { 2986 tcp_respond(tp, t_template->tt_ipgen, 2987 &t_template->tt_t, (struct mbuf *)NULL, 2988 tp->rcv_nxt, tp->snd_una - 1, 0); 2989 /* This sends an ack */ 2990 if (tp->t_flags & TF_DELACK) 2991 tp->t_flags &= ~TF_DELACK; 2992 free(t_template, M_TEMP); 2993 } 2994 if (tp->t_rxtshift < TCP_MAXRXTSHIFT) 2995 tp->t_rxtshift++; 2996 out: 2997 rack_log_to_event(rack, RACK_TO_FRM_PERSIST, 0); 2998 rack_start_hpts_timer(rack, tp, cts, 2999 0, 0, 0); 3000 return (retval); 3001 } 3002 3003 /* 3004 * If a keepalive goes off, we had no other timers 3005 * happening. We always return 1 here since this 3006 * routine either drops the connection or sends 3007 * out a segment with respond. 3008 */ 3009 static int 3010 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 3011 { 3012 struct tcptemp *t_template; 3013 struct inpcb *inp; 3014 3015 if (tp->t_timers->tt_flags & TT_STOPPED) { 3016 return (1); 3017 } 3018 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP; 3019 inp = tp->t_inpcb; 3020 rack_log_to_event(rack, RACK_TO_FRM_KEEP, 0); 3021 /* 3022 * Keep-alive timer went off; send something or drop connection if 3023 * idle for too long. 3024 */ 3025 KMOD_TCPSTAT_INC(tcps_keeptimeo); 3026 if (tp->t_state < TCPS_ESTABLISHED) 3027 goto dropit; 3028 if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) && 3029 tp->t_state <= TCPS_CLOSING) { 3030 if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp)) 3031 goto dropit; 3032 /* 3033 * Send a packet designed to force a response if the peer is 3034 * up and reachable: either an ACK if the connection is 3035 * still alive, or an RST if the peer has closed the 3036 * connection due to timeout or reboot. Using sequence 3037 * number tp->snd_una-1 causes the transmitted zero-length 3038 * segment to lie outside the receive window; by the 3039 * protocol spec, this requires the correspondent TCP to 3040 * respond. 3041 */ 3042 KMOD_TCPSTAT_INC(tcps_keepprobe); 3043 t_template = tcpip_maketemplate(inp); 3044 if (t_template) { 3045 tcp_respond(tp, t_template->tt_ipgen, 3046 &t_template->tt_t, (struct mbuf *)NULL, 3047 tp->rcv_nxt, tp->snd_una - 1, 0); 3048 free(t_template, M_TEMP); 3049 } 3050 } 3051 rack_start_hpts_timer(rack, tp, cts, 0, 0, 0); 3052 return (1); 3053 dropit: 3054 KMOD_TCPSTAT_INC(tcps_keepdrops); 3055 tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT); 3056 return (1); 3057 } 3058 3059 /* 3060 * Retransmit helper function, clear up all the ack 3061 * flags and take care of important book keeping. 3062 */ 3063 static void 3064 rack_remxt_tmr(struct tcpcb *tp) 3065 { 3066 /* 3067 * The retransmit timer went off, all sack'd blocks must be 3068 * un-acked. 3069 */ 3070 struct rack_sendmap *rsm, *trsm = NULL; 3071 struct tcp_rack *rack; 3072 int32_t cnt = 0; 3073 3074 rack = (struct tcp_rack *)tp->t_fb_ptr; 3075 rack_timer_cancel(tp, rack, tcp_ts_getticks(), __LINE__); 3076 rack_log_to_event(rack, RACK_TO_FRM_TMR, 0); 3077 if (rack->r_state && (rack->r_state != tp->t_state)) 3078 rack_set_state(tp, rack); 3079 /* 3080 * Ideally we would like to be able to 3081 * mark SACK-PASS on anything not acked here. 3082 * However, if we do that we would burst out 3083 * all that data 1ms apart. This would be unwise, 3084 * so for now we will just let the normal rxt timer 3085 * and tlp timer take care of it. 3086 */ 3087 RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) { 3088 if (rsm->r_flags & RACK_ACKED) { 3089 cnt++; 3090 rsm->r_dupack = 0; 3091 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 3092 if (rsm->r_in_tmap == 0) { 3093 /* We must re-add it back to the tlist */ 3094 if (trsm == NULL) { 3095 TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext); 3096 } else { 3097 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext); 3098 } 3099 rsm->r_in_tmap = 1; 3100 } 3101 } 3102 trsm = rsm; 3103 rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS); 3104 } 3105 /* Clear the count (we just un-acked them) */ 3106 rack->r_ctl.rc_sacked = 0; 3107 /* Clear the tlp rtx mark */ 3108 rack->r_ctl.rc_tlp_rtx_out = 0; 3109 rack->r_ctl.rc_tlp_seg_send_cnt = 0; 3110 rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 3111 rack->r_ctl.rc_prr_sndcnt = 0; 3112 rack_log_to_prr(rack, 6); 3113 rack->r_timer_override = 1; 3114 } 3115 3116 /* 3117 * Re-transmit timeout! If we drop the PCB we will return 1, otherwise 3118 * we will setup to retransmit the lowest seq number outstanding. 3119 */ 3120 static int 3121 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts) 3122 { 3123 int32_t rexmt; 3124 struct inpcb *inp; 3125 int32_t retval = 0; 3126 bool isipv6; 3127 3128 inp = tp->t_inpcb; 3129 if (tp->t_timers->tt_flags & TT_STOPPED) { 3130 return (1); 3131 } 3132 if (rack_progress_timeout_check(tp)) { 3133 tcp_set_inp_to_drop(inp, ETIMEDOUT); 3134 return (1); 3135 } 3136 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT; 3137 if (TCPS_HAVEESTABLISHED(tp->t_state) && 3138 (tp->snd_una == tp->snd_max)) { 3139 /* Nothing outstanding .. nothing to do */ 3140 return (0); 3141 } 3142 /* 3143 * Retransmission timer went off. Message has not been acked within 3144 * retransmit interval. Back off to a longer retransmit interval 3145 * and retransmit one segment. 3146 */ 3147 rack_remxt_tmr(tp); 3148 if ((rack->r_ctl.rc_resend == NULL) || 3149 ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) { 3150 /* 3151 * If the rwnd collapsed on 3152 * the one we are retransmitting 3153 * it does not count against the 3154 * rxt count. 3155 */ 3156 tp->t_rxtshift++; 3157 } 3158 if (tp->t_rxtshift > TCP_MAXRXTSHIFT) { 3159 tp->t_rxtshift = TCP_MAXRXTSHIFT; 3160 KMOD_TCPSTAT_INC(tcps_timeoutdrop); 3161 retval = 1; 3162 tcp_set_inp_to_drop(rack->rc_inp, 3163 (tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT)); 3164 goto out; 3165 } 3166 if (tp->t_state == TCPS_SYN_SENT) { 3167 /* 3168 * If the SYN was retransmitted, indicate CWND to be limited 3169 * to 1 segment in cc_conn_init(). 3170 */ 3171 tp->snd_cwnd = 1; 3172 } else if (tp->t_rxtshift == 1) { 3173 /* 3174 * first retransmit; record ssthresh and cwnd so they can be 3175 * recovered if this turns out to be a "bad" retransmit. A 3176 * retransmit is considered "bad" if an ACK for this segment 3177 * is received within RTT/2 interval; the assumption here is 3178 * that the ACK was already in flight. See "On Estimating 3179 * End-to-End Network Path Properties" by Allman and Paxson 3180 * for more details. 3181 */ 3182 tp->snd_cwnd_prev = tp->snd_cwnd; 3183 tp->snd_ssthresh_prev = tp->snd_ssthresh; 3184 tp->snd_recover_prev = tp->snd_recover; 3185 if (IN_FASTRECOVERY(tp->t_flags)) 3186 tp->t_flags |= TF_WASFRECOVERY; 3187 else 3188 tp->t_flags &= ~TF_WASFRECOVERY; 3189 if (IN_CONGRECOVERY(tp->t_flags)) 3190 tp->t_flags |= TF_WASCRECOVERY; 3191 else 3192 tp->t_flags &= ~TF_WASCRECOVERY; 3193 tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1)); 3194 tp->t_flags |= TF_PREVVALID; 3195 } else 3196 tp->t_flags &= ~TF_PREVVALID; 3197 KMOD_TCPSTAT_INC(tcps_rexmttimeo); 3198 if ((tp->t_state == TCPS_SYN_SENT) || 3199 (tp->t_state == TCPS_SYN_RECEIVED)) 3200 rexmt = MSEC_2_TICKS(RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift]); 3201 else 3202 rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift]; 3203 TCPT_RANGESET(tp->t_rxtcur, rexmt, 3204 max(MSEC_2_TICKS(rack_rto_min), rexmt), 3205 MSEC_2_TICKS(rack_rto_max)); 3206 /* 3207 * We enter the path for PLMTUD if connection is established or, if 3208 * connection is FIN_WAIT_1 status, reason for the last is that if 3209 * amount of data we send is very small, we could send it in couple 3210 * of packets and process straight to FIN. In that case we won't 3211 * catch ESTABLISHED state. 3212 */ 3213 #ifdef INET6 3214 isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? true : false; 3215 #else 3216 isipv6 = false; 3217 #endif 3218 if (((V_tcp_pmtud_blackhole_detect == 1) || 3219 (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) || 3220 (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) && 3221 ((tp->t_state == TCPS_ESTABLISHED) || 3222 (tp->t_state == TCPS_FIN_WAIT_1))) { 3223 3224 /* 3225 * Idea here is that at each stage of mtu probe (usually, 3226 * 1448 -> 1188 -> 524) should be given 2 chances to recover 3227 * before further clamping down. 'tp->t_rxtshift % 2 == 0' 3228 * should take care of that. 3229 */ 3230 if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) == 3231 (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) && 3232 (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 && 3233 tp->t_rxtshift % 2 == 0)) { 3234 /* 3235 * Enter Path MTU Black-hole Detection mechanism: - 3236 * Disable Path MTU Discovery (IP "DF" bit). - 3237 * Reduce MTU to lower value than what we negotiated 3238 * with peer. 3239 */ 3240 if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) { 3241 /* Record that we may have found a black hole. */ 3242 tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE; 3243 /* Keep track of previous MSS. */ 3244 tp->t_pmtud_saved_maxseg = tp->t_maxseg; 3245 } 3246 3247 /* 3248 * Reduce the MSS to blackhole value or to the 3249 * default in an attempt to retransmit. 3250 */ 3251 #ifdef INET6 3252 if (isipv6 && 3253 tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) { 3254 /* Use the sysctl tuneable blackhole MSS. */ 3255 tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss; 3256 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated); 3257 } else if (isipv6) { 3258 /* Use the default MSS. */ 3259 tp->t_maxseg = V_tcp_v6mssdflt; 3260 /* 3261 * Disable Path MTU Discovery when we switch 3262 * to minmss. 3263 */ 3264 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD; 3265 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss); 3266 } 3267 #endif 3268 #if defined(INET6) && defined(INET) 3269 else 3270 #endif 3271 #ifdef INET 3272 if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) { 3273 /* Use the sysctl tuneable blackhole MSS. */ 3274 tp->t_maxseg = V_tcp_pmtud_blackhole_mss; 3275 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated); 3276 } else { 3277 /* Use the default MSS. */ 3278 tp->t_maxseg = V_tcp_mssdflt; 3279 /* 3280 * Disable Path MTU Discovery when we switch 3281 * to minmss. 3282 */ 3283 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD; 3284 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss); 3285 } 3286 #endif 3287 } else { 3288 /* 3289 * If further retransmissions are still unsuccessful 3290 * with a lowered MTU, maybe this isn't a blackhole 3291 * and we restore the previous MSS and blackhole 3292 * detection flags. The limit '6' is determined by 3293 * giving each probe stage (1448, 1188, 524) 2 3294 * chances to recover. 3295 */ 3296 if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) && 3297 (tp->t_rxtshift >= 6)) { 3298 tp->t_flags2 |= TF2_PLPMTU_PMTUD; 3299 tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE; 3300 tp->t_maxseg = tp->t_pmtud_saved_maxseg; 3301 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed); 3302 } 3303 } 3304 } 3305 /* 3306 * If we backed off this far, our srtt estimate is probably bogus. 3307 * Clobber it so we'll take the next rtt measurement as our srtt; 3308 * move the current srtt into rttvar to keep the current retransmit 3309 * times until then. 3310 */ 3311 if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) { 3312 #ifdef INET6 3313 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) 3314 in6_losing(tp->t_inpcb); 3315 else 3316 #endif 3317 in_losing(tp->t_inpcb); 3318 tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT); 3319 tp->t_srtt = 0; 3320 } 3321 if (rack_use_sack_filter) 3322 sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una); 3323 tp->snd_recover = tp->snd_max; 3324 tp->t_flags |= TF_ACKNOW; 3325 tp->t_rtttime = 0; 3326 rack_cong_signal(tp, NULL, CC_RTO); 3327 out: 3328 return (retval); 3329 } 3330 3331 static int 3332 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling) 3333 { 3334 int32_t ret = 0; 3335 int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK); 3336 3337 if (timers == 0) { 3338 return (0); 3339 } 3340 if (tp->t_state == TCPS_LISTEN) { 3341 /* no timers on listen sockets */ 3342 if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) 3343 return (0); 3344 return (1); 3345 } 3346 if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) { 3347 uint32_t left; 3348 3349 if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) { 3350 ret = -1; 3351 rack_log_to_processing(rack, cts, ret, 0); 3352 return (0); 3353 } 3354 if (hpts_calling == 0) { 3355 ret = -2; 3356 rack_log_to_processing(rack, cts, ret, 0); 3357 return (0); 3358 } 3359 /* 3360 * Ok our timer went off early and we are not paced false 3361 * alarm, go back to sleep. 3362 */ 3363 ret = -3; 3364 left = rack->r_ctl.rc_timer_exp - cts; 3365 tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(left)); 3366 rack_log_to_processing(rack, cts, ret, left); 3367 rack->rc_last_pto_set = 0; 3368 return (1); 3369 } 3370 rack->rc_tmr_stopped = 0; 3371 rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK; 3372 if (timers & PACE_TMR_DELACK) { 3373 ret = rack_timeout_delack(tp, rack, cts); 3374 } else if (timers & PACE_TMR_RACK) { 3375 rack->r_ctl.rc_tlp_rxt_last_time = cts; 3376 ret = rack_timeout_rack(tp, rack, cts); 3377 } else if (timers & PACE_TMR_TLP) { 3378 rack->r_ctl.rc_tlp_rxt_last_time = cts; 3379 ret = rack_timeout_tlp(tp, rack, cts); 3380 } else if (timers & PACE_TMR_RXT) { 3381 rack->r_ctl.rc_tlp_rxt_last_time = cts; 3382 ret = rack_timeout_rxt(tp, rack, cts); 3383 } else if (timers & PACE_TMR_PERSIT) { 3384 ret = rack_timeout_persist(tp, rack, cts); 3385 } else if (timers & PACE_TMR_KEEP) { 3386 ret = rack_timeout_keepalive(tp, rack, cts); 3387 } 3388 rack_log_to_processing(rack, cts, ret, timers); 3389 return (ret); 3390 } 3391 3392 static void 3393 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line) 3394 { 3395 uint8_t hpts_removed = 0; 3396 3397 if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) && 3398 TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) { 3399 tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT); 3400 hpts_removed = 1; 3401 } 3402 if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) { 3403 rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK; 3404 if (rack->rc_inp->inp_in_hpts && 3405 ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) { 3406 /* 3407 * Canceling timer's when we have no output being 3408 * paced. We also must remove ourselves from the 3409 * hpts. 3410 */ 3411 tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT); 3412 hpts_removed = 1; 3413 } 3414 rack_log_to_cancel(rack, hpts_removed, line); 3415 rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK); 3416 } 3417 } 3418 3419 static void 3420 rack_timer_stop(struct tcpcb *tp, uint32_t timer_type) 3421 { 3422 return; 3423 } 3424 3425 static int 3426 rack_stopall(struct tcpcb *tp) 3427 { 3428 struct tcp_rack *rack; 3429 rack = (struct tcp_rack *)tp->t_fb_ptr; 3430 rack->t_timers_stopped = 1; 3431 return (0); 3432 } 3433 3434 static void 3435 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta) 3436 { 3437 return; 3438 } 3439 3440 static int 3441 rack_timer_active(struct tcpcb *tp, uint32_t timer_type) 3442 { 3443 return (0); 3444 } 3445 3446 static void 3447 rack_stop_all_timers(struct tcpcb *tp) 3448 { 3449 struct tcp_rack *rack; 3450 3451 /* 3452 * Assure no timers are running. 3453 */ 3454 if (tcp_timer_active(tp, TT_PERSIST)) { 3455 /* We enter in persists, set the flag appropriately */ 3456 rack = (struct tcp_rack *)tp->t_fb_ptr; 3457 rack->rc_in_persist = 1; 3458 } 3459 tcp_timer_suspend(tp, TT_PERSIST); 3460 tcp_timer_suspend(tp, TT_REXMT); 3461 tcp_timer_suspend(tp, TT_KEEP); 3462 tcp_timer_suspend(tp, TT_DELACK); 3463 } 3464 3465 static void 3466 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack, 3467 struct rack_sendmap *rsm, uint32_t ts) 3468 { 3469 int32_t idx; 3470 3471 rsm->r_rtr_cnt++; 3472 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 3473 rsm->r_dupack = 0; 3474 if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) { 3475 rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS; 3476 rsm->r_flags |= RACK_OVERMAX; 3477 } 3478 if ((rsm->r_rtr_cnt > 1) && (rack->r_tlp_running == 0)) { 3479 rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start); 3480 rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start); 3481 } 3482 idx = rsm->r_rtr_cnt - 1; 3483 rsm->r_tim_lastsent[idx] = ts; 3484 if (rsm->r_flags & RACK_ACKED) { 3485 /* Problably MTU discovery messing with us */ 3486 rsm->r_flags &= ~RACK_ACKED; 3487 rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start); 3488 } 3489 if (rsm->r_in_tmap) { 3490 TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext); 3491 rsm->r_in_tmap = 0; 3492 } 3493 TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext); 3494 rsm->r_in_tmap = 1; 3495 if (rsm->r_flags & RACK_SACK_PASSED) { 3496 /* We have retransmitted due to the SACK pass */ 3497 rsm->r_flags &= ~RACK_SACK_PASSED; 3498 rsm->r_flags |= RACK_WAS_SACKPASS; 3499 } 3500 } 3501 3502 3503 static uint32_t 3504 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack, 3505 struct rack_sendmap *rsm, uint32_t ts, int32_t *lenp) 3506 { 3507 /* 3508 * We (re-)transmitted starting at rsm->r_start for some length 3509 * (possibly less than r_end. 3510 */ 3511 struct rack_sendmap *nrsm, *insret; 3512 uint32_t c_end; 3513 int32_t len; 3514 3515 len = *lenp; 3516 c_end = rsm->r_start + len; 3517 if (SEQ_GEQ(c_end, rsm->r_end)) { 3518 /* 3519 * We retransmitted the whole piece or more than the whole 3520 * slopping into the next rsm. 3521 */ 3522 rack_update_rsm(tp, rack, rsm, ts); 3523 if (c_end == rsm->r_end) { 3524 *lenp = 0; 3525 return (0); 3526 } else { 3527 int32_t act_len; 3528 3529 /* Hangs over the end return whats left */ 3530 act_len = rsm->r_end - rsm->r_start; 3531 *lenp = (len - act_len); 3532 return (rsm->r_end); 3533 } 3534 /* We don't get out of this block. */ 3535 } 3536 /* 3537 * Here we retransmitted less than the whole thing which means we 3538 * have to split this into what was transmitted and what was not. 3539 */ 3540 nrsm = rack_alloc_full_limit(rack); 3541 if (nrsm == NULL) { 3542 /* 3543 * We can't get memory, so lets not proceed. 3544 */ 3545 *lenp = 0; 3546 return (0); 3547 } 3548 /* 3549 * So here we are going to take the original rsm and make it what we 3550 * retransmitted. nrsm will be the tail portion we did not 3551 * retransmit. For example say the chunk was 1, 11 (10 bytes). And 3552 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to 3553 * 1, 6 and the new piece will be 6, 11. 3554 */ 3555 rack_clone_rsm(rack, nrsm, rsm, c_end); 3556 nrsm->r_dupack = 0; 3557 rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2); 3558 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 3559 #ifdef INVARIANTS 3560 if (insret != NULL) { 3561 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 3562 nrsm, insret, rack, rsm); 3563 } 3564 #endif 3565 if (rsm->r_in_tmap) { 3566 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 3567 nrsm->r_in_tmap = 1; 3568 } 3569 rsm->r_flags &= (~RACK_HAS_FIN); 3570 rack_update_rsm(tp, rack, rsm, ts); 3571 *lenp = 0; 3572 return (0); 3573 } 3574 3575 3576 static void 3577 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len, 3578 uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t ts, 3579 uint8_t pass, struct rack_sendmap *hintrsm) 3580 { 3581 struct tcp_rack *rack; 3582 struct rack_sendmap *rsm, *nrsm, *insret, fe; 3583 register uint32_t snd_max, snd_una; 3584 3585 /* 3586 * Add to the RACK log of packets in flight or retransmitted. If 3587 * there is a TS option we will use the TS echoed, if not we will 3588 * grab a TS. 3589 * 3590 * Retransmissions will increment the count and move the ts to its 3591 * proper place. Note that if options do not include TS's then we 3592 * won't be able to effectively use the ACK for an RTT on a retran. 3593 * 3594 * Notes about r_start and r_end. Lets consider a send starting at 3595 * sequence 1 for 10 bytes. In such an example the r_start would be 3596 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11. 3597 * This means that r_end is actually the first sequence for the next 3598 * slot (11). 3599 * 3600 */ 3601 /* 3602 * If err is set what do we do XXXrrs? should we not add the thing? 3603 * -- i.e. return if err != 0 or should we pretend we sent it? -- 3604 * i.e. proceed with add ** do this for now. 3605 */ 3606 INP_WLOCK_ASSERT(tp->t_inpcb); 3607 if (err) 3608 /* 3609 * We don't log errors -- we could but snd_max does not 3610 * advance in this case either. 3611 */ 3612 return; 3613 3614 if (th_flags & TH_RST) { 3615 /* 3616 * We don't log resets and we return immediately from 3617 * sending 3618 */ 3619 return; 3620 } 3621 rack = (struct tcp_rack *)tp->t_fb_ptr; 3622 snd_una = tp->snd_una; 3623 if (SEQ_LEQ((seq_out + len), snd_una)) { 3624 /* Are sending an old segment to induce an ack (keep-alive)? */ 3625 return; 3626 } 3627 if (SEQ_LT(seq_out, snd_una)) { 3628 /* huh? should we panic? */ 3629 uint32_t end; 3630 3631 end = seq_out + len; 3632 seq_out = snd_una; 3633 if (SEQ_GEQ(end, seq_out)) 3634 len = end - seq_out; 3635 else 3636 len = 0; 3637 } 3638 snd_max = tp->snd_max; 3639 if (th_flags & (TH_SYN | TH_FIN)) { 3640 /* 3641 * The call to rack_log_output is made before bumping 3642 * snd_max. This means we can record one extra byte on a SYN 3643 * or FIN if seq_out is adding more on and a FIN is present 3644 * (and we are not resending). 3645 */ 3646 if (th_flags & TH_SYN) 3647 len++; 3648 if (th_flags & TH_FIN) 3649 len++; 3650 if (SEQ_LT(snd_max, tp->snd_nxt)) { 3651 /* 3652 * The add/update as not been done for the FIN/SYN 3653 * yet. 3654 */ 3655 snd_max = tp->snd_nxt; 3656 } 3657 } 3658 if (len == 0) { 3659 /* We don't log zero window probes */ 3660 return; 3661 } 3662 rack->r_ctl.rc_time_last_sent = ts; 3663 if (IN_RECOVERY(tp->t_flags)) { 3664 rack->r_ctl.rc_prr_out += len; 3665 } 3666 /* First question is it a retransmission or new? */ 3667 if (seq_out == snd_max) { 3668 /* Its new */ 3669 again: 3670 rsm = rack_alloc(rack); 3671 if (rsm == NULL) { 3672 /* 3673 * Hmm out of memory and the tcb got destroyed while 3674 * we tried to wait. 3675 */ 3676 return; 3677 } 3678 if (th_flags & TH_FIN) { 3679 rsm->r_flags = RACK_HAS_FIN; 3680 } else { 3681 rsm->r_flags = 0; 3682 } 3683 rsm->r_tim_lastsent[0] = ts; 3684 rsm->r_rtr_cnt = 1; 3685 rsm->r_rtr_bytes = 0; 3686 if (th_flags & TH_SYN) { 3687 /* The data space is one beyond snd_una */ 3688 rsm->r_start = seq_out + 1; 3689 rsm->r_end = rsm->r_start + (len - 1); 3690 } else { 3691 /* Normal case */ 3692 rsm->r_start = seq_out; 3693 rsm->r_end = rsm->r_start + len; 3694 } 3695 rsm->r_dupack = 0; 3696 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 3697 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 3698 #ifdef INVARIANTS 3699 if (insret != NULL) { 3700 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 3701 nrsm, insret, rack, rsm); 3702 } 3703 #endif 3704 TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext); 3705 rsm->r_in_tmap = 1; 3706 return; 3707 } 3708 /* 3709 * If we reach here its a retransmission and we need to find it. 3710 */ 3711 memset(&fe, 0, sizeof(fe)); 3712 more: 3713 if (hintrsm && (hintrsm->r_start == seq_out)) { 3714 rsm = hintrsm; 3715 hintrsm = NULL; 3716 } else { 3717 /* No hints sorry */ 3718 rsm = NULL; 3719 } 3720 if ((rsm) && (rsm->r_start == seq_out)) { 3721 seq_out = rack_update_entry(tp, rack, rsm, ts, &len); 3722 if (len == 0) { 3723 return; 3724 } else { 3725 goto more; 3726 } 3727 } 3728 /* Ok it was not the last pointer go through it the hard way. */ 3729 refind: 3730 fe.r_start = seq_out; 3731 rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe); 3732 if (rsm) { 3733 if (rsm->r_start == seq_out) { 3734 seq_out = rack_update_entry(tp, rack, rsm, ts, &len); 3735 if (len == 0) { 3736 return; 3737 } else { 3738 goto refind; 3739 } 3740 } 3741 if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) { 3742 /* Transmitted within this piece */ 3743 /* 3744 * Ok we must split off the front and then let the 3745 * update do the rest 3746 */ 3747 nrsm = rack_alloc_full_limit(rack); 3748 if (nrsm == NULL) { 3749 rack_update_rsm(tp, rack, rsm, ts); 3750 return; 3751 } 3752 /* 3753 * copy rsm to nrsm and then trim the front of rsm 3754 * to not include this part. 3755 */ 3756 rack_clone_rsm(rack, nrsm, rsm, seq_out); 3757 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 3758 #ifdef INVARIANTS 3759 if (insret != NULL) { 3760 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 3761 nrsm, insret, rack, rsm); 3762 } 3763 #endif 3764 if (rsm->r_in_tmap) { 3765 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 3766 nrsm->r_in_tmap = 1; 3767 } 3768 rsm->r_flags &= (~RACK_HAS_FIN); 3769 seq_out = rack_update_entry(tp, rack, nrsm, ts, &len); 3770 if (len == 0) { 3771 return; 3772 } else if (len > 0) 3773 goto refind; 3774 } 3775 } 3776 /* 3777 * Hmm not found in map did they retransmit both old and on into the 3778 * new? 3779 */ 3780 if (seq_out == tp->snd_max) { 3781 goto again; 3782 } else if (SEQ_LT(seq_out, tp->snd_max)) { 3783 #ifdef INVARIANTS 3784 printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n", 3785 seq_out, len, tp->snd_una, tp->snd_max); 3786 printf("Starting Dump of all rack entries\n"); 3787 RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) { 3788 printf("rsm:%p start:%u end:%u\n", 3789 rsm, rsm->r_start, rsm->r_end); 3790 } 3791 printf("Dump complete\n"); 3792 panic("seq_out not found rack:%p tp:%p", 3793 rack, tp); 3794 #endif 3795 } else { 3796 #ifdef INVARIANTS 3797 /* 3798 * Hmm beyond sndmax? (only if we are using the new rtt-pack 3799 * flag) 3800 */ 3801 panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p", 3802 seq_out, len, tp->snd_max, tp); 3803 #endif 3804 } 3805 } 3806 3807 /* 3808 * Record one of the RTT updates from an ack into 3809 * our sample structure. 3810 */ 3811 static void 3812 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt) 3813 { 3814 if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) || 3815 (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) { 3816 rack->r_ctl.rack_rs.rs_rtt_lowest = rtt; 3817 } 3818 if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) || 3819 (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) { 3820 rack->r_ctl.rack_rs.rs_rtt_highest = rtt; 3821 } 3822 rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID; 3823 rack->r_ctl.rack_rs.rs_rtt_tot += rtt; 3824 rack->r_ctl.rack_rs.rs_rtt_cnt++; 3825 } 3826 3827 /* 3828 * Collect new round-trip time estimate 3829 * and update averages and current timeout. 3830 */ 3831 static void 3832 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp) 3833 { 3834 int32_t delta; 3835 uint32_t o_srtt, o_var; 3836 int32_t rtt; 3837 3838 if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) 3839 /* No valid sample */ 3840 return; 3841 if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) { 3842 /* We are to use the lowest RTT seen in a single ack */ 3843 rtt = rack->r_ctl.rack_rs.rs_rtt_lowest; 3844 } else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) { 3845 /* We are to use the highest RTT seen in a single ack */ 3846 rtt = rack->r_ctl.rack_rs.rs_rtt_highest; 3847 } else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) { 3848 /* We are to use the average RTT seen in a single ack */ 3849 rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot / 3850 (uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt); 3851 } else { 3852 #ifdef INVARIANTS 3853 panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method); 3854 #endif 3855 return; 3856 } 3857 if (rtt == 0) 3858 rtt = 1; 3859 rack_log_rtt_sample(rack, rtt); 3860 o_srtt = tp->t_srtt; 3861 o_var = tp->t_rttvar; 3862 rack = (struct tcp_rack *)tp->t_fb_ptr; 3863 if (tp->t_srtt != 0) { 3864 /* 3865 * srtt is stored as fixed point with 5 bits after the 3866 * binary point (i.e., scaled by 8). The following magic is 3867 * equivalent to the smoothing algorithm in rfc793 with an 3868 * alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed point). 3869 * Adjust rtt to origin 0. 3870 */ 3871 delta = ((rtt - 1) << TCP_DELTA_SHIFT) 3872 - (tp->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)); 3873 3874 tp->t_srtt += delta; 3875 if (tp->t_srtt <= 0) 3876 tp->t_srtt = 1; 3877 3878 /* 3879 * We accumulate a smoothed rtt variance (actually, a 3880 * smoothed mean difference), then set the retransmit timer 3881 * to smoothed rtt + 4 times the smoothed variance. rttvar 3882 * is stored as fixed point with 4 bits after the binary 3883 * point (scaled by 16). The following is equivalent to 3884 * rfc793 smoothing with an alpha of .75 (rttvar = 3885 * rttvar*3/4 + |delta| / 4). This replaces rfc793's 3886 * wired-in beta. 3887 */ 3888 if (delta < 0) 3889 delta = -delta; 3890 delta -= tp->t_rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT); 3891 tp->t_rttvar += delta; 3892 if (tp->t_rttvar <= 0) 3893 tp->t_rttvar = 1; 3894 if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar) 3895 tp->t_rttbest = tp->t_srtt + tp->t_rttvar; 3896 } else { 3897 /* 3898 * No rtt measurement yet - use the unsmoothed rtt. Set the 3899 * variance to half the rtt (so our first retransmit happens 3900 * at 3*rtt). 3901 */ 3902 tp->t_srtt = rtt << TCP_RTT_SHIFT; 3903 tp->t_rttvar = rtt << (TCP_RTTVAR_SHIFT - 1); 3904 tp->t_rttbest = tp->t_srtt + tp->t_rttvar; 3905 } 3906 KMOD_TCPSTAT_INC(tcps_rttupdated); 3907 rack_log_rtt_upd(tp, rack, rtt, o_srtt, o_var); 3908 tp->t_rttupdated++; 3909 #ifdef STATS 3910 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt)); 3911 #endif 3912 tp->t_rxtshift = 0; 3913 3914 /* 3915 * the retransmit should happen at rtt + 4 * rttvar. Because of the 3916 * way we do the smoothing, srtt and rttvar will each average +1/2 3917 * tick of bias. When we compute the retransmit timer, we want 1/2 3918 * tick of rounding and 1 extra tick because of +-1/2 tick 3919 * uncertainty in the firing of the timer. The bias will give us 3920 * exactly the 1.5 tick we need. But, because the bias is 3921 * statistical, we have to test that we don't drop below the minimum 3922 * feasible timer (which is 2 ticks). 3923 */ 3924 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), 3925 max(MSEC_2_TICKS(rack_rto_min), rtt + 2), MSEC_2_TICKS(rack_rto_max)); 3926 tp->t_softerror = 0; 3927 } 3928 3929 static void 3930 rack_earlier_retran(struct tcpcb *tp, struct rack_sendmap *rsm, 3931 uint32_t t, uint32_t cts) 3932 { 3933 /* 3934 * For this RSM, we acknowledged the data from a previous 3935 * transmission, not the last one we made. This means we did a false 3936 * retransmit. 3937 */ 3938 struct tcp_rack *rack; 3939 3940 if (rsm->r_flags & RACK_HAS_FIN) { 3941 /* 3942 * The sending of the FIN often is multiple sent when we 3943 * have everything outstanding ack'd. We ignore this case 3944 * since its over now. 3945 */ 3946 return; 3947 } 3948 if (rsm->r_flags & RACK_TLP) { 3949 /* 3950 * We expect TLP's to have this occur. 3951 */ 3952 return; 3953 } 3954 rack = (struct tcp_rack *)tp->t_fb_ptr; 3955 /* should we undo cc changes and exit recovery? */ 3956 if (IN_RECOVERY(tp->t_flags)) { 3957 if (rack->r_ctl.rc_rsm_start == rsm->r_start) { 3958 /* 3959 * Undo what we ratched down and exit recovery if 3960 * possible 3961 */ 3962 EXIT_RECOVERY(tp->t_flags); 3963 tp->snd_recover = tp->snd_una; 3964 if (rack->r_ctl.rc_cwnd_at > tp->snd_cwnd) 3965 tp->snd_cwnd = rack->r_ctl.rc_cwnd_at; 3966 if (rack->r_ctl.rc_ssthresh_at > tp->snd_ssthresh) 3967 tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at; 3968 } 3969 } 3970 if (rsm->r_flags & RACK_WAS_SACKPASS) { 3971 /* 3972 * We retransmitted based on a sack and the earlier 3973 * retransmission ack'd it - re-ordering is occuring. 3974 */ 3975 counter_u64_add(rack_reorder_seen, 1); 3976 rack->r_ctl.rc_reorder_ts = cts; 3977 } 3978 counter_u64_add(rack_badfr, 1); 3979 counter_u64_add(rack_badfr_bytes, (rsm->r_end - rsm->r_start)); 3980 } 3981 3982 3983 static int 3984 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack, 3985 struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type) 3986 { 3987 int32_t i; 3988 uint32_t t; 3989 3990 if (rsm->r_flags & RACK_ACKED) 3991 /* Already done */ 3992 return (0); 3993 3994 3995 if ((rsm->r_rtr_cnt == 1) || 3996 ((ack_type == CUM_ACKED) && 3997 (to->to_flags & TOF_TS) && 3998 (to->to_tsecr) && 3999 (rsm->r_tim_lastsent[rsm->r_rtr_cnt - 1] == to->to_tsecr)) 4000 ) { 4001 /* 4002 * We will only find a matching timestamp if its cum-acked. 4003 * But if its only one retransmission its for-sure matching 4004 * :-) 4005 */ 4006 t = cts - rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]; 4007 if ((int)t <= 0) 4008 t = 1; 4009 if (!tp->t_rttlow || tp->t_rttlow > t) 4010 tp->t_rttlow = t; 4011 if (!rack->r_ctl.rc_rack_min_rtt || 4012 SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) { 4013 rack->r_ctl.rc_rack_min_rtt = t; 4014 if (rack->r_ctl.rc_rack_min_rtt == 0) { 4015 rack->r_ctl.rc_rack_min_rtt = 1; 4016 } 4017 } 4018 tcp_rack_xmit_timer(rack, t + 1); 4019 if ((rsm->r_flags & RACK_TLP) && 4020 (!IN_RECOVERY(tp->t_flags))) { 4021 /* Segment was a TLP and our retrans matched */ 4022 if (rack->r_ctl.rc_tlp_cwnd_reduce) { 4023 rack->r_ctl.rc_rsm_start = tp->snd_max; 4024 rack->r_ctl.rc_cwnd_at = tp->snd_cwnd; 4025 rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh; 4026 rack_cong_signal(tp, NULL, CC_NDUPACK); 4027 /* 4028 * When we enter recovery we need to assure 4029 * we send one packet. 4030 */ 4031 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 4032 rack_log_to_prr(rack, 7); 4033 } 4034 } 4035 if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) { 4036 /* New more recent rack_tmit_time */ 4037 rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]; 4038 rack->rc_rack_rtt = t; 4039 } 4040 return (1); 4041 } 4042 /* 4043 * We clear the soft/rxtshift since we got an ack. 4044 * There is no assurance we will call the commit() function 4045 * so we need to clear these to avoid incorrect handling. 4046 */ 4047 tp->t_rxtshift = 0; 4048 tp->t_softerror = 0; 4049 if ((to->to_flags & TOF_TS) && 4050 (ack_type == CUM_ACKED) && 4051 (to->to_tsecr) && 4052 ((rsm->r_flags & RACK_OVERMAX) == 0)) { 4053 /* 4054 * Now which timestamp does it match? In this block the ACK 4055 * must be coming from a previous transmission. 4056 */ 4057 for (i = 0; i < rsm->r_rtr_cnt; i++) { 4058 if (rsm->r_tim_lastsent[i] == to->to_tsecr) { 4059 t = cts - rsm->r_tim_lastsent[i]; 4060 if ((int)t <= 0) 4061 t = 1; 4062 if ((i + 1) < rsm->r_rtr_cnt) { 4063 /* Likely */ 4064 rack_earlier_retran(tp, rsm, t, cts); 4065 } 4066 if (!tp->t_rttlow || tp->t_rttlow > t) 4067 tp->t_rttlow = t; 4068 if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) { 4069 rack->r_ctl.rc_rack_min_rtt = t; 4070 if (rack->r_ctl.rc_rack_min_rtt == 0) { 4071 rack->r_ctl.rc_rack_min_rtt = 1; 4072 } 4073 } 4074 /* 4075 * Note the following calls to 4076 * tcp_rack_xmit_timer() are being commented 4077 * out for now. They give us no more accuracy 4078 * and often lead to a wrong choice. We have 4079 * enough samples that have not been 4080 * retransmitted. I leave the commented out 4081 * code in here in case in the future we 4082 * decide to add it back (though I can't forsee 4083 * doing that). That way we will easily see 4084 * where they need to be placed. 4085 */ 4086 if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, 4087 rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) { 4088 /* New more recent rack_tmit_time */ 4089 rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]; 4090 rack->rc_rack_rtt = t; 4091 } 4092 return (1); 4093 } 4094 } 4095 goto ts_not_found; 4096 } else { 4097 /* 4098 * Ok its a SACK block that we retransmitted. or a windows 4099 * machine without timestamps. We can tell nothing from the 4100 * time-stamp since its not there or the time the peer last 4101 * recieved a segment that moved forward its cum-ack point. 4102 */ 4103 ts_not_found: 4104 i = rsm->r_rtr_cnt - 1; 4105 t = cts - rsm->r_tim_lastsent[i]; 4106 if ((int)t <= 0) 4107 t = 1; 4108 if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) { 4109 /* 4110 * We retransmitted and the ack came back in less 4111 * than the smallest rtt we have observed. We most 4112 * likey did an improper retransmit as outlined in 4113 * 4.2 Step 3 point 2 in the rack-draft. 4114 */ 4115 i = rsm->r_rtr_cnt - 2; 4116 t = cts - rsm->r_tim_lastsent[i]; 4117 rack_earlier_retran(tp, rsm, t, cts); 4118 } else if (rack->r_ctl.rc_rack_min_rtt) { 4119 /* 4120 * We retransmitted it and the retransmit did the 4121 * job. 4122 */ 4123 if (!rack->r_ctl.rc_rack_min_rtt || 4124 SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) { 4125 rack->r_ctl.rc_rack_min_rtt = t; 4126 if (rack->r_ctl.rc_rack_min_rtt == 0) { 4127 rack->r_ctl.rc_rack_min_rtt = 1; 4128 } 4129 } 4130 if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, rsm->r_tim_lastsent[i])) { 4131 /* New more recent rack_tmit_time */ 4132 rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[i]; 4133 rack->rc_rack_rtt = t; 4134 } 4135 return (1); 4136 } 4137 } 4138 return (0); 4139 } 4140 4141 /* 4142 * Mark the SACK_PASSED flag on all entries prior to rsm send wise. 4143 */ 4144 static void 4145 rack_log_sack_passed(struct tcpcb *tp, 4146 struct tcp_rack *rack, struct rack_sendmap *rsm) 4147 { 4148 struct rack_sendmap *nrsm; 4149 4150 nrsm = rsm; 4151 TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap, 4152 rack_head, r_tnext) { 4153 if (nrsm == rsm) { 4154 /* Skip orginal segment he is acked */ 4155 continue; 4156 } 4157 if (nrsm->r_flags & RACK_ACKED) { 4158 /* 4159 * Skip ack'd segments, though we 4160 * should not see these, since tmap 4161 * should not have ack'd segments. 4162 */ 4163 continue; 4164 } 4165 if (nrsm->r_flags & RACK_SACK_PASSED) { 4166 /* 4167 * We found one that is already marked 4168 * passed, we have been here before and 4169 * so all others below this are marked. 4170 */ 4171 break; 4172 } 4173 nrsm->r_flags |= RACK_SACK_PASSED; 4174 nrsm->r_flags &= ~RACK_WAS_SACKPASS; 4175 } 4176 } 4177 4178 static uint32_t 4179 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack, 4180 struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two) 4181 { 4182 uint32_t start, end, changed = 0; 4183 struct rack_sendmap stack_map; 4184 struct rack_sendmap *rsm, *nrsm, fe, *insret, *prev, *next; 4185 int32_t used_ref = 1; 4186 int moved = 0; 4187 4188 start = sack->start; 4189 end = sack->end; 4190 rsm = *prsm; 4191 memset(&fe, 0, sizeof(fe)); 4192 do_rest_ofb: 4193 if ((rsm == NULL) || 4194 (SEQ_LT(end, rsm->r_start)) || 4195 (SEQ_GEQ(start, rsm->r_end)) || 4196 (SEQ_LT(start, rsm->r_start))) { 4197 /* 4198 * We are not in the right spot, 4199 * find the correct spot in the tree. 4200 */ 4201 used_ref = 0; 4202 fe.r_start = start; 4203 rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe); 4204 moved++; 4205 } 4206 if (rsm == NULL) { 4207 /* TSNH */ 4208 goto out; 4209 } 4210 /* Ok we have an ACK for some piece of this rsm */ 4211 if (rsm->r_start != start) { 4212 if ((rsm->r_flags & RACK_ACKED) == 0) { 4213 /** 4214 * Need to split this in two pieces the before and after, 4215 * the before remains in the map, the after must be 4216 * added. In other words we have: 4217 * rsm |--------------| 4218 * sackblk |-------> 4219 * rsm will become 4220 * rsm |---| 4221 * and nrsm will be the sacked piece 4222 * nrsm |----------| 4223 * 4224 * But before we start down that path lets 4225 * see if the sack spans over on top of 4226 * the next guy and it is already sacked. 4227 */ 4228 next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4229 if (next && (next->r_flags & RACK_ACKED) && 4230 SEQ_GEQ(end, next->r_start)) { 4231 /** 4232 * So the next one is already acked, and 4233 * we can thus by hookery use our stack_map 4234 * to reflect the piece being sacked and 4235 * then adjust the two tree entries moving 4236 * the start and ends around. So we start like: 4237 * rsm |------------| (not-acked) 4238 * next |-----------| (acked) 4239 * sackblk |--------> 4240 * We want to end like so: 4241 * rsm |------| (not-acked) 4242 * next |-----------------| (acked) 4243 * nrsm |-----| 4244 * Where nrsm is a temporary stack piece we 4245 * use to update all the gizmos. 4246 */ 4247 /* Copy up our fudge block */ 4248 nrsm = &stack_map; 4249 memcpy(nrsm, rsm, sizeof(struct rack_sendmap)); 4250 /* Now adjust our tree blocks */ 4251 rsm->r_end = start; 4252 next->r_start = start; 4253 /* Clear out the dup ack count of the remainder */ 4254 rsm->r_dupack = 0; 4255 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 4256 /* Now lets make sure our fudge block is right */ 4257 nrsm->r_start = start; 4258 /* Now lets update all the stats and such */ 4259 rack_update_rtt(tp, rack, nrsm, to, cts, SACKED); 4260 changed += (nrsm->r_end - nrsm->r_start); 4261 rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start); 4262 if (nrsm->r_flags & RACK_SACK_PASSED) { 4263 counter_u64_add(rack_reorder_seen, 1); 4264 rack->r_ctl.rc_reorder_ts = cts; 4265 } 4266 /* 4267 * Now we want to go up from rsm (the 4268 * one left un-acked) to the next one 4269 * in the tmap. We do this so when 4270 * we walk backwards we include marking 4271 * sack-passed on rsm (The one passed in 4272 * is skipped since it is generally called 4273 * on something sacked before removing it 4274 * from the tmap). 4275 */ 4276 if (rsm->r_in_tmap) { 4277 nrsm = TAILQ_NEXT(rsm, r_tnext); 4278 /* 4279 * Now that we have the next 4280 * one walk backwards from there. 4281 */ 4282 if (nrsm && nrsm->r_in_tmap) 4283 rack_log_sack_passed(tp, rack, nrsm); 4284 } 4285 /* Now are we done? */ 4286 if (SEQ_LT(end, next->r_end) || 4287 (end == next->r_end)) { 4288 /* Done with block */ 4289 goto out; 4290 } 4291 counter_u64_add(rack_sack_used_next_merge, 1); 4292 /* Postion for the next block */ 4293 start = next->r_end; 4294 rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next); 4295 if (rsm == NULL) 4296 goto out; 4297 } else { 4298 /** 4299 * We can't use any hookery here, so we 4300 * need to split the map. We enter like 4301 * so: 4302 * rsm |--------| 4303 * sackblk |-----> 4304 * We will add the new block nrsm and 4305 * that will be the new portion, and then 4306 * fall through after reseting rsm. So we 4307 * split and look like this: 4308 * rsm |----| 4309 * sackblk |-----> 4310 * nrsm |---| 4311 * We then fall through reseting 4312 * rsm to nrsm, so the next block 4313 * picks it up. 4314 */ 4315 nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT); 4316 if (nrsm == NULL) { 4317 /* 4318 * failed XXXrrs what can we do but loose the sack 4319 * info? 4320 */ 4321 goto out; 4322 } 4323 counter_u64_add(rack_sack_splits, 1); 4324 rack_clone_rsm(rack, nrsm, rsm, start); 4325 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 4326 #ifdef INVARIANTS 4327 if (insret != NULL) { 4328 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 4329 nrsm, insret, rack, rsm); 4330 } 4331 #endif 4332 if (rsm->r_in_tmap) { 4333 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 4334 nrsm->r_in_tmap = 1; 4335 } 4336 rsm->r_flags &= (~RACK_HAS_FIN); 4337 /* Position us to point to the new nrsm that starts the sack blk */ 4338 rsm = nrsm; 4339 } 4340 } else { 4341 /* Already sacked this piece */ 4342 counter_u64_add(rack_sack_skipped_acked, 1); 4343 moved++; 4344 if (end == rsm->r_end) { 4345 /* Done with block */ 4346 rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4347 goto out; 4348 } else if (SEQ_LT(end, rsm->r_end)) { 4349 /* A partial sack to a already sacked block */ 4350 moved++; 4351 rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4352 goto out; 4353 } else { 4354 /* 4355 * The end goes beyond this guy 4356 * repostion the start to the 4357 * next block. 4358 */ 4359 start = rsm->r_end; 4360 rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4361 if (rsm == NULL) 4362 goto out; 4363 } 4364 } 4365 } 4366 if (SEQ_GEQ(end, rsm->r_end)) { 4367 /** 4368 * The end of this block is either beyond this guy or right 4369 * at this guy. I.e.: 4370 * rsm --- |-----| 4371 * end |-----| 4372 * <or> 4373 * end |---------| 4374 */ 4375 if (rsm->r_flags & RACK_TLP) 4376 rack->r_ctl.rc_tlp_rtx_out = 0; 4377 if ((rsm->r_flags & RACK_ACKED) == 0) { 4378 rack_update_rtt(tp, rack, rsm, to, cts, SACKED); 4379 changed += (rsm->r_end - rsm->r_start); 4380 rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start); 4381 if (rsm->r_in_tmap) /* should be true */ 4382 rack_log_sack_passed(tp, rack, rsm); 4383 /* Is Reordering occuring? */ 4384 if (rsm->r_flags & RACK_SACK_PASSED) { 4385 rsm->r_flags &= ~RACK_SACK_PASSED; 4386 counter_u64_add(rack_reorder_seen, 1); 4387 rack->r_ctl.rc_reorder_ts = cts; 4388 } 4389 rsm->r_flags |= RACK_ACKED; 4390 rsm->r_flags &= ~RACK_TLP; 4391 if (rsm->r_in_tmap) { 4392 TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext); 4393 rsm->r_in_tmap = 0; 4394 } 4395 } else { 4396 counter_u64_add(rack_sack_skipped_acked, 1); 4397 moved++; 4398 } 4399 if (end == rsm->r_end) { 4400 /* This block only - done, setup for next */ 4401 goto out; 4402 } 4403 /* 4404 * There is more not coverend by this rsm move on 4405 * to the next block in the RB tree. 4406 */ 4407 nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4408 start = rsm->r_end; 4409 rsm = nrsm; 4410 if (rsm == NULL) 4411 goto out; 4412 goto do_rest_ofb; 4413 } 4414 /** 4415 * The end of this sack block is smaller than 4416 * our rsm i.e.: 4417 * rsm --- |-----| 4418 * end |--| 4419 */ 4420 if ((rsm->r_flags & RACK_ACKED) == 0) { 4421 prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4422 if (prev && (prev->r_flags & RACK_ACKED)) { 4423 /** 4424 * Goal, we want the right remainder of rsm to shrink 4425 * in place and span from (rsm->r_start = end) to rsm->r_end. 4426 * We want to expand prev to go all the way 4427 * to prev->r_end <- end. 4428 * so in the tree we have before: 4429 * prev |--------| (acked) 4430 * rsm |-------| (non-acked) 4431 * sackblk |-| 4432 * We churn it so we end up with 4433 * prev |----------| (acked) 4434 * rsm |-----| (non-acked) 4435 * nrsm |-| (temporary) 4436 */ 4437 nrsm = &stack_map; 4438 memcpy(nrsm, rsm, sizeof(struct rack_sendmap)); 4439 prev->r_end = end; 4440 rsm->r_start = end; 4441 /* Now adjust nrsm (stack copy) to be 4442 * the one that is the small 4443 * piece that was "sacked". 4444 */ 4445 nrsm->r_end = end; 4446 rsm->r_dupack = 0; 4447 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 4448 /* 4449 * Now nrsm is our new little piece 4450 * that is acked (which was merged 4451 * to prev). Update the rtt and changed 4452 * based on that. Also check for reordering. 4453 */ 4454 rack_update_rtt(tp, rack, nrsm, to, cts, SACKED); 4455 changed += (nrsm->r_end - nrsm->r_start); 4456 rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start); 4457 if (nrsm->r_flags & RACK_SACK_PASSED) { 4458 counter_u64_add(rack_reorder_seen, 1); 4459 rack->r_ctl.rc_reorder_ts = cts; 4460 } 4461 rsm = prev; 4462 counter_u64_add(rack_sack_used_prev_merge, 1); 4463 } else { 4464 /** 4465 * This is the case where our previous 4466 * block is not acked either, so we must 4467 * split the block in two. 4468 */ 4469 nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT); 4470 if (nrsm == NULL) { 4471 /* failed rrs what can we do but loose the sack info? */ 4472 goto out; 4473 } 4474 /** 4475 * In this case nrsm becomes 4476 * nrsm->r_start = end; 4477 * nrsm->r_end = rsm->r_end; 4478 * which is un-acked. 4479 * <and> 4480 * rsm->r_end = nrsm->r_start; 4481 * i.e. the remaining un-acked 4482 * piece is left on the left 4483 * hand side. 4484 * 4485 * So we start like this 4486 * rsm |----------| (not acked) 4487 * sackblk |---| 4488 * build it so we have 4489 * rsm |---| (acked) 4490 * nrsm |------| (not acked) 4491 */ 4492 counter_u64_add(rack_sack_splits, 1); 4493 rack_clone_rsm(rack, nrsm, rsm, end); 4494 rsm->r_flags &= (~RACK_HAS_FIN); 4495 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 4496 #ifdef INVARIANTS 4497 if (insret != NULL) { 4498 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 4499 nrsm, insret, rack, rsm); 4500 } 4501 #endif 4502 if (rsm->r_in_tmap) { 4503 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 4504 nrsm->r_in_tmap = 1; 4505 } 4506 nrsm->r_dupack = 0; 4507 rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2); 4508 if (rsm->r_flags & RACK_TLP) 4509 rack->r_ctl.rc_tlp_rtx_out = 0; 4510 rack_update_rtt(tp, rack, rsm, to, cts, SACKED); 4511 changed += (rsm->r_end - rsm->r_start); 4512 rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start); 4513 if (rsm->r_in_tmap) /* should be true */ 4514 rack_log_sack_passed(tp, rack, rsm); 4515 /* Is Reordering occuring? */ 4516 if (rsm->r_flags & RACK_SACK_PASSED) { 4517 rsm->r_flags &= ~RACK_SACK_PASSED; 4518 counter_u64_add(rack_reorder_seen, 1); 4519 rack->r_ctl.rc_reorder_ts = cts; 4520 } 4521 rsm->r_flags |= RACK_ACKED; 4522 rsm->r_flags &= ~RACK_TLP; 4523 if (rsm->r_in_tmap) { 4524 TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext); 4525 rsm->r_in_tmap = 0; 4526 } 4527 } 4528 } else if (start != end){ 4529 /* 4530 * The block was already acked. 4531 */ 4532 counter_u64_add(rack_sack_skipped_acked, 1); 4533 moved++; 4534 } 4535 out: 4536 if (rsm && (rsm->r_flags & RACK_ACKED)) { 4537 /* 4538 * Now can we merge where we worked 4539 * with either the previous or 4540 * next block? 4541 */ 4542 next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4543 while (next) { 4544 if (next->r_flags & RACK_ACKED) { 4545 /* yep this and next can be merged */ 4546 rsm = rack_merge_rsm(rack, rsm, next); 4547 next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4548 } else 4549 break; 4550 } 4551 /* Now what about the previous? */ 4552 prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4553 while (prev) { 4554 if (prev->r_flags & RACK_ACKED) { 4555 /* yep the previous and this can be merged */ 4556 rsm = rack_merge_rsm(rack, prev, rsm); 4557 prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4558 } else 4559 break; 4560 } 4561 } 4562 if (used_ref == 0) { 4563 counter_u64_add(rack_sack_proc_all, 1); 4564 } else { 4565 counter_u64_add(rack_sack_proc_short, 1); 4566 } 4567 /* Save off the next one for quick reference. */ 4568 if (rsm) 4569 nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4570 else 4571 nrsm = NULL; 4572 *prsm = rack->r_ctl.rc_sacklast = nrsm; 4573 /* Pass back the moved. */ 4574 *moved_two = moved; 4575 return (changed); 4576 } 4577 4578 static void inline 4579 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack) 4580 { 4581 struct rack_sendmap *tmap; 4582 4583 tmap = NULL; 4584 while (rsm && (rsm->r_flags & RACK_ACKED)) { 4585 /* Its no longer sacked, mark it so */ 4586 rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start); 4587 #ifdef INVARIANTS 4588 if (rsm->r_in_tmap) { 4589 panic("rack:%p rsm:%p flags:0x%x in tmap?", 4590 rack, rsm, rsm->r_flags); 4591 } 4592 #endif 4593 rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS); 4594 /* Rebuild it into our tmap */ 4595 if (tmap == NULL) { 4596 TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext); 4597 tmap = rsm; 4598 } else { 4599 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext); 4600 tmap = rsm; 4601 } 4602 tmap->r_in_tmap = 1; 4603 rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4604 } 4605 /* 4606 * Now lets possibly clear the sack filter so we start 4607 * recognizing sacks that cover this area. 4608 */ 4609 if (rack_use_sack_filter) 4610 sack_filter_clear(&rack->r_ctl.rack_sf, th_ack); 4611 4612 } 4613 4614 static void 4615 rack_do_decay(struct tcp_rack *rack) 4616 { 4617 #ifdef NETFLIX_EXP_DETECTION 4618 struct timeval res; 4619 4620 #define timersub(tvp, uvp, vvp) \ 4621 do { \ 4622 (vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec; \ 4623 (vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec; \ 4624 if ((vvp)->tv_usec < 0) { \ 4625 (vvp)->tv_sec--; \ 4626 (vvp)->tv_usec += 1000000; \ 4627 } \ 4628 } while (0) 4629 4630 timersub(&rack->r_ctl.rc_last_ack, &rack->r_ctl.rc_last_time_decay, &res); 4631 #undef timersub 4632 4633 rack->r_ctl.input_pkt++; 4634 if ((rack->rc_in_persist) || 4635 (res.tv_sec >= 1) || 4636 (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) { 4637 /* 4638 * Check for decay of non-SAD, 4639 * we want all SAD detection metrics to 4640 * decay 1/4 per second (or more) passed. 4641 */ 4642 uint32_t pkt_delta; 4643 4644 pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt; 4645 /* Update our saved tracking values */ 4646 rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt; 4647 rack->r_ctl.rc_last_time_decay = rack->r_ctl.rc_last_ack; 4648 /* Now do we escape without decay? */ 4649 if (rack->rc_in_persist || 4650 (rack->rc_tp->snd_max == rack->rc_tp->snd_una) || 4651 (pkt_delta < tcp_sad_low_pps)){ 4652 /* 4653 * We don't decay idle connections 4654 * or ones that have a low input pps. 4655 */ 4656 return; 4657 } 4658 /* Decay the counters */ 4659 rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count, 4660 tcp_sad_decay_val); 4661 rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count, 4662 tcp_sad_decay_val); 4663 rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra, 4664 tcp_sad_decay_val); 4665 rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move, 4666 tcp_sad_decay_val); 4667 } 4668 #endif 4669 } 4670 4671 static void 4672 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th) 4673 { 4674 uint32_t changed, entered_recovery = 0; 4675 struct tcp_rack *rack; 4676 struct rack_sendmap *rsm, *rm; 4677 struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1]; 4678 register uint32_t th_ack; 4679 int32_t i, j, k, num_sack_blks = 0; 4680 uint32_t cts, acked, ack_point, sack_changed = 0; 4681 int loop_start = 0, moved_two = 0; 4682 4683 INP_WLOCK_ASSERT(tp->t_inpcb); 4684 if (th->th_flags & TH_RST) { 4685 /* We don't log resets */ 4686 return; 4687 } 4688 rack = (struct tcp_rack *)tp->t_fb_ptr; 4689 cts = tcp_ts_getticks(); 4690 rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 4691 changed = 0; 4692 th_ack = th->th_ack; 4693 if (rack->sack_attack_disable == 0) 4694 rack_do_decay(rack); 4695 if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) { 4696 /* 4697 * You only get credit for 4698 * MSS and greater (and you get extra 4699 * credit for larger cum-ack moves). 4700 */ 4701 int ac; 4702 4703 ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp); 4704 rack->r_ctl.ack_count += ac; 4705 counter_u64_add(rack_ack_total, ac); 4706 } 4707 if (rack->r_ctl.ack_count > 0xfff00000) { 4708 /* 4709 * reduce the number to keep us under 4710 * a uint32_t. 4711 */ 4712 rack->r_ctl.ack_count /= 2; 4713 rack->r_ctl.sack_count /= 2; 4714 } 4715 if (SEQ_GT(th_ack, tp->snd_una)) { 4716 rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__); 4717 tp->t_acktime = ticks; 4718 } 4719 if (rsm && SEQ_GT(th_ack, rsm->r_start)) 4720 changed = th_ack - rsm->r_start; 4721 if (changed) { 4722 /* 4723 * The ACK point is advancing to th_ack, we must drop off 4724 * the packets in the rack log and calculate any eligble 4725 * RTT's. 4726 */ 4727 rack->r_wanted_output++; 4728 more: 4729 rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 4730 if (rsm == NULL) { 4731 if ((th_ack - 1) == tp->iss) { 4732 /* 4733 * For the SYN incoming case we will not 4734 * have called tcp_output for the sending of 4735 * the SYN, so there will be no map. All 4736 * other cases should probably be a panic. 4737 */ 4738 goto proc_sack; 4739 } 4740 if (tp->t_flags & TF_SENTFIN) { 4741 /* if we send a FIN we will not hav a map */ 4742 goto proc_sack; 4743 } 4744 #ifdef INVARIANTS 4745 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", 4746 tp, 4747 th, tp->t_state, rack, 4748 tp->snd_una, tp->snd_max, tp->snd_nxt, changed); 4749 #endif 4750 goto proc_sack; 4751 } 4752 if (SEQ_LT(th_ack, rsm->r_start)) { 4753 /* Huh map is missing this */ 4754 #ifdef INVARIANTS 4755 printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n", 4756 rsm->r_start, 4757 th_ack, tp->t_state, rack->r_state); 4758 #endif 4759 goto proc_sack; 4760 } 4761 rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED); 4762 /* Now do we consume the whole thing? */ 4763 if (SEQ_GEQ(th_ack, rsm->r_end)) { 4764 /* Its all consumed. */ 4765 uint32_t left; 4766 4767 rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes; 4768 rsm->r_rtr_bytes = 0; 4769 if (rsm->r_flags & RACK_TLP) 4770 rack->r_ctl.rc_tlp_rtx_out = 0; 4771 rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 4772 #ifdef INVARIANTS 4773 if (rm != rsm) { 4774 panic("removing head in rack:%p rsm:%p rm:%p", 4775 rack, rsm, rm); 4776 } 4777 #endif 4778 if (rsm->r_in_tmap) { 4779 TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext); 4780 rsm->r_in_tmap = 0; 4781 } 4782 if (rsm->r_flags & RACK_ACKED) { 4783 /* 4784 * It was acked on the scoreboard -- remove 4785 * it from total 4786 */ 4787 rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start); 4788 } else if (rsm->r_flags & RACK_SACK_PASSED) { 4789 /* 4790 * There are segments ACKED on the 4791 * scoreboard further up. We are seeing 4792 * reordering. 4793 */ 4794 rsm->r_flags &= ~RACK_SACK_PASSED; 4795 counter_u64_add(rack_reorder_seen, 1); 4796 rsm->r_flags |= RACK_ACKED; 4797 rack->r_ctl.rc_reorder_ts = cts; 4798 } 4799 left = th_ack - rsm->r_end; 4800 if (rsm->r_rtr_cnt > 1) { 4801 /* 4802 * Technically we should make r_rtr_cnt be 4803 * monotonicly increasing and just mod it to 4804 * the timestamp it is replacing.. that way 4805 * we would have the last 3 retransmits. Now 4806 * rc_loss_count will be wrong if we 4807 * retransmit something more than 2 times in 4808 * recovery :( 4809 */ 4810 rack->r_ctl.rc_loss_count += (rsm->r_rtr_cnt - 1); 4811 } 4812 /* Free back to zone */ 4813 rack_free(rack, rsm); 4814 if (left) { 4815 goto more; 4816 } 4817 goto proc_sack; 4818 } 4819 if (rsm->r_flags & RACK_ACKED) { 4820 /* 4821 * It was acked on the scoreboard -- remove it from 4822 * total for the part being cum-acked. 4823 */ 4824 rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start); 4825 } 4826 /* 4827 * Clear the dup ack count for 4828 * the piece that remains. 4829 */ 4830 rsm->r_dupack = 0; 4831 rack_log_retran_reason(rack, rsm, __LINE__, 0, 2); 4832 if (rsm->r_rtr_bytes) { 4833 /* 4834 * It was retransmitted adjust the 4835 * sack holes for what was acked. 4836 */ 4837 int ack_am; 4838 4839 ack_am = (th_ack - rsm->r_start); 4840 if (ack_am >= rsm->r_rtr_bytes) { 4841 rack->r_ctl.rc_holes_rxt -= ack_am; 4842 rsm->r_rtr_bytes -= ack_am; 4843 } 4844 } 4845 /* Update where the piece starts */ 4846 rsm->r_start = th_ack; 4847 } 4848 proc_sack: 4849 /* Check for reneging */ 4850 rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree); 4851 if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) { 4852 /* 4853 * The peer has moved snd_una up to 4854 * the edge of this send, i.e. one 4855 * that it had previously acked. The only 4856 * way that can be true if the peer threw 4857 * away data (space issues) that it had 4858 * previously sacked (else it would have 4859 * given us snd_una up to (rsm->r_end). 4860 * We need to undo the acked markings here. 4861 * 4862 * Note we have to look to make sure th_ack is 4863 * our rsm->r_start in case we get an old ack 4864 * where th_ack is behind snd_una. 4865 */ 4866 rack_peer_reneges(rack, rsm, th->th_ack); 4867 } 4868 if ((to->to_flags & TOF_SACK) == 0) { 4869 /* We are done nothing left */ 4870 goto out; 4871 } 4872 /* Sack block processing */ 4873 if (SEQ_GT(th_ack, tp->snd_una)) 4874 ack_point = th_ack; 4875 else 4876 ack_point = tp->snd_una; 4877 for (i = 0; i < to->to_nsacks; i++) { 4878 bcopy((to->to_sacks + i * TCPOLEN_SACK), 4879 &sack, sizeof(sack)); 4880 sack.start = ntohl(sack.start); 4881 sack.end = ntohl(sack.end); 4882 if (SEQ_GT(sack.end, sack.start) && 4883 SEQ_GT(sack.start, ack_point) && 4884 SEQ_LT(sack.start, tp->snd_max) && 4885 SEQ_GT(sack.end, ack_point) && 4886 SEQ_LEQ(sack.end, tp->snd_max)) { 4887 sack_blocks[num_sack_blks] = sack; 4888 num_sack_blks++; 4889 #ifdef NETFLIX_STATS 4890 } else if (SEQ_LEQ(sack.start, th_ack) && 4891 SEQ_LEQ(sack.end, th_ack)) { 4892 /* 4893 * Its a D-SACK block. 4894 */ 4895 tcp_record_dsack(sack.start, sack.end); 4896 #endif 4897 } 4898 4899 } 4900 /* 4901 * Sort the SACK blocks so we can update the rack scoreboard with 4902 * just one pass. 4903 */ 4904 if (rack_use_sack_filter) { 4905 num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks, 4906 num_sack_blks, th->th_ack); 4907 ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks); 4908 } 4909 if (num_sack_blks == 0) { 4910 /* Nothing to sack (DSACKs?) */ 4911 goto out_with_totals; 4912 } 4913 if (num_sack_blks < 2) { 4914 /* Only one, we don't need to sort */ 4915 goto do_sack_work; 4916 } 4917 /* Sort the sacks */ 4918 for (i = 0; i < num_sack_blks; i++) { 4919 for (j = i + 1; j < num_sack_blks; j++) { 4920 if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) { 4921 sack = sack_blocks[i]; 4922 sack_blocks[i] = sack_blocks[j]; 4923 sack_blocks[j] = sack; 4924 } 4925 } 4926 } 4927 /* 4928 * Now are any of the sack block ends the same (yes some 4929 * implementations send these)? 4930 */ 4931 again: 4932 if (num_sack_blks == 0) 4933 goto out_with_totals; 4934 if (num_sack_blks > 1) { 4935 for (i = 0; i < num_sack_blks; i++) { 4936 for (j = i + 1; j < num_sack_blks; j++) { 4937 if (sack_blocks[i].end == sack_blocks[j].end) { 4938 /* 4939 * Ok these two have the same end we 4940 * want the smallest end and then 4941 * throw away the larger and start 4942 * again. 4943 */ 4944 if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) { 4945 /* 4946 * The second block covers 4947 * more area use that 4948 */ 4949 sack_blocks[i].start = sack_blocks[j].start; 4950 } 4951 /* 4952 * Now collapse out the dup-sack and 4953 * lower the count 4954 */ 4955 for (k = (j + 1); k < num_sack_blks; k++) { 4956 sack_blocks[j].start = sack_blocks[k].start; 4957 sack_blocks[j].end = sack_blocks[k].end; 4958 j++; 4959 } 4960 num_sack_blks--; 4961 goto again; 4962 } 4963 } 4964 } 4965 } 4966 do_sack_work: 4967 /* 4968 * First lets look to see if 4969 * we have retransmitted and 4970 * can use the transmit next? 4971 */ 4972 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 4973 if (rsm && 4974 SEQ_GT(sack_blocks[0].end, rsm->r_start) && 4975 SEQ_LT(sack_blocks[0].start, rsm->r_end)) { 4976 /* 4977 * We probably did the FR and the next 4978 * SACK in continues as we would expect. 4979 */ 4980 acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two); 4981 if (acked) { 4982 rack->r_wanted_output++; 4983 changed += acked; 4984 sack_changed += acked; 4985 } 4986 if (num_sack_blks == 1) { 4987 /* 4988 * This is what we would expect from 4989 * a normal implementation to happen 4990 * after we have retransmitted the FR, 4991 * i.e the sack-filter pushes down 4992 * to 1 block and the next to be retransmitted 4993 * is the sequence in the sack block (has more 4994 * are acked). Count this as ACK'd data to boost 4995 * up the chances of recovering any false positives. 4996 */ 4997 rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp)); 4998 counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp))); 4999 counter_u64_add(rack_express_sack, 1); 5000 if (rack->r_ctl.ack_count > 0xfff00000) { 5001 /* 5002 * reduce the number to keep us under 5003 * a uint32_t. 5004 */ 5005 rack->r_ctl.ack_count /= 2; 5006 rack->r_ctl.sack_count /= 2; 5007 } 5008 goto out_with_totals; 5009 } else { 5010 /* 5011 * Start the loop through the 5012 * rest of blocks, past the first block. 5013 */ 5014 moved_two = 0; 5015 loop_start = 1; 5016 } 5017 } 5018 /* Its a sack of some sort */ 5019 rack->r_ctl.sack_count++; 5020 if (rack->r_ctl.sack_count > 0xfff00000) { 5021 /* 5022 * reduce the number to keep us under 5023 * a uint32_t. 5024 */ 5025 rack->r_ctl.ack_count /= 2; 5026 rack->r_ctl.sack_count /= 2; 5027 } 5028 counter_u64_add(rack_sack_total, 1); 5029 if (rack->sack_attack_disable) { 5030 /* An attacker disablement is in place */ 5031 if (num_sack_blks > 1) { 5032 rack->r_ctl.sack_count += (num_sack_blks - 1); 5033 rack->r_ctl.sack_moved_extra++; 5034 counter_u64_add(rack_move_some, 1); 5035 if (rack->r_ctl.sack_moved_extra > 0xfff00000) { 5036 rack->r_ctl.sack_moved_extra /= 2; 5037 rack->r_ctl.sack_noextra_move /= 2; 5038 } 5039 } 5040 goto out; 5041 } 5042 rsm = rack->r_ctl.rc_sacklast; 5043 for (i = loop_start; i < num_sack_blks; i++) { 5044 acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two); 5045 if (acked) { 5046 rack->r_wanted_output++; 5047 changed += acked; 5048 sack_changed += acked; 5049 } 5050 if (moved_two) { 5051 /* 5052 * If we did not get a SACK for at least a MSS and 5053 * had to move at all, or if we moved more than our 5054 * threshold, it counts against the "extra" move. 5055 */ 5056 rack->r_ctl.sack_moved_extra += moved_two; 5057 counter_u64_add(rack_move_some, 1); 5058 } else { 5059 /* 5060 * else we did not have to move 5061 * any more than we would expect. 5062 */ 5063 rack->r_ctl.sack_noextra_move++; 5064 counter_u64_add(rack_move_none, 1); 5065 } 5066 if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) { 5067 /* 5068 * If the SACK was not a full MSS then 5069 * we add to sack_count the number of 5070 * MSS's (or possibly more than 5071 * a MSS if its a TSO send) we had to skip by. 5072 */ 5073 rack->r_ctl.sack_count += moved_two; 5074 counter_u64_add(rack_sack_total, moved_two); 5075 } 5076 /* 5077 * Now we need to setup for the next 5078 * round. First we make sure we won't 5079 * exceed the size of our uint32_t on 5080 * the various counts, and then clear out 5081 * moved_two. 5082 */ 5083 if ((rack->r_ctl.sack_moved_extra > 0xfff00000) || 5084 (rack->r_ctl.sack_noextra_move > 0xfff00000)) { 5085 rack->r_ctl.sack_moved_extra /= 2; 5086 rack->r_ctl.sack_noextra_move /= 2; 5087 } 5088 if (rack->r_ctl.sack_count > 0xfff00000) { 5089 rack->r_ctl.ack_count /= 2; 5090 rack->r_ctl.sack_count /= 2; 5091 } 5092 moved_two = 0; 5093 } 5094 out_with_totals: 5095 if (num_sack_blks > 1) { 5096 /* 5097 * You get an extra stroke if 5098 * you have more than one sack-blk, this 5099 * could be where we are skipping forward 5100 * and the sack-filter is still working, or 5101 * it could be an attacker constantly 5102 * moving us. 5103 */ 5104 rack->r_ctl.sack_moved_extra++; 5105 counter_u64_add(rack_move_some, 1); 5106 } 5107 out: 5108 #ifdef NETFLIX_EXP_DETECTION 5109 if ((rack->do_detection || tcp_force_detection) && 5110 tcp_sack_to_ack_thresh && 5111 tcp_sack_to_move_thresh && 5112 ((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) { 5113 /* 5114 * We have thresholds set to find 5115 * possible attackers and disable sack. 5116 * Check them. 5117 */ 5118 uint64_t ackratio, moveratio, movetotal; 5119 5120 /* Log detecting */ 5121 rack_log_sad(rack, 1); 5122 ackratio = (uint64_t)(rack->r_ctl.sack_count); 5123 ackratio *= (uint64_t)(1000); 5124 if (rack->r_ctl.ack_count) 5125 ackratio /= (uint64_t)(rack->r_ctl.ack_count); 5126 else { 5127 /* We really should not hit here */ 5128 ackratio = 1000; 5129 } 5130 if ((rack->sack_attack_disable == 0) && 5131 (ackratio > rack_highest_sack_thresh_seen)) 5132 rack_highest_sack_thresh_seen = (uint32_t)ackratio; 5133 movetotal = rack->r_ctl.sack_moved_extra; 5134 movetotal += rack->r_ctl.sack_noextra_move; 5135 moveratio = rack->r_ctl.sack_moved_extra; 5136 moveratio *= (uint64_t)1000; 5137 if (movetotal) 5138 moveratio /= movetotal; 5139 else { 5140 /* No moves, thats pretty good */ 5141 moveratio = 0; 5142 } 5143 if ((rack->sack_attack_disable == 0) && 5144 (moveratio > rack_highest_move_thresh_seen)) 5145 rack_highest_move_thresh_seen = (uint32_t)moveratio; 5146 if (rack->sack_attack_disable == 0) { 5147 if ((ackratio > tcp_sack_to_ack_thresh) && 5148 (moveratio > tcp_sack_to_move_thresh)) { 5149 /* Disable sack processing */ 5150 rack->sack_attack_disable = 1; 5151 if (rack->r_rep_attack == 0) { 5152 rack->r_rep_attack = 1; 5153 counter_u64_add(rack_sack_attacks_detected, 1); 5154 } 5155 if (tcp_attack_on_turns_on_logging) { 5156 /* 5157 * Turn on logging, used for debugging 5158 * false positives. 5159 */ 5160 rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging; 5161 } 5162 /* Clamp the cwnd at flight size */ 5163 rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd; 5164 rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 5165 rack_log_sad(rack, 2); 5166 } 5167 } else { 5168 /* We are sack-disabled check for false positives */ 5169 if ((ackratio <= tcp_restoral_thresh) || 5170 (rack->r_ctl.rc_num_maps_alloced < tcp_map_minimum)) { 5171 rack->sack_attack_disable = 0; 5172 rack_log_sad(rack, 3); 5173 /* Restart counting */ 5174 rack->r_ctl.sack_count = 0; 5175 rack->r_ctl.sack_moved_extra = 0; 5176 rack->r_ctl.sack_noextra_move = 1; 5177 rack->r_ctl.ack_count = max(1, 5178 (BYTES_THIS_ACK(tp, th)/ctf_fixed_maxseg(rack->rc_tp))); 5179 5180 if (rack->r_rep_reverse == 0) { 5181 rack->r_rep_reverse = 1; 5182 counter_u64_add(rack_sack_attacks_reversed, 1); 5183 } 5184 /* Restore the cwnd */ 5185 if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd) 5186 rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd; 5187 } 5188 } 5189 } 5190 #endif 5191 if (changed) { 5192 /* Something changed cancel the rack timer */ 5193 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 5194 } 5195 if ((sack_changed) && (!IN_RECOVERY(tp->t_flags))) { 5196 /* 5197 * Ok we have a high probability that we need to go in to 5198 * recovery since we have data sack'd 5199 */ 5200 struct rack_sendmap *rsm; 5201 uint32_t tsused; 5202 5203 tsused = tcp_ts_getticks(); 5204 rsm = tcp_rack_output(tp, rack, tsused); 5205 if (rsm) { 5206 /* Enter recovery */ 5207 rack->r_ctl.rc_rsm_start = rsm->r_start; 5208 rack->r_ctl.rc_cwnd_at = tp->snd_cwnd; 5209 rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh; 5210 entered_recovery = 1; 5211 rack_cong_signal(tp, NULL, CC_NDUPACK); 5212 /* 5213 * When we enter recovery we need to assure we send 5214 * one packet. 5215 */ 5216 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 5217 rack_log_to_prr(rack, 8); 5218 rack->r_timer_override = 1; 5219 } 5220 } 5221 if (IN_RECOVERY(tp->t_flags) && (entered_recovery == 0)) { 5222 /* Deal with changed and PRR here (in recovery only) */ 5223 uint32_t pipe, snd_una; 5224 5225 rack->r_ctl.rc_prr_delivered += changed; 5226 /* Compute prr_sndcnt */ 5227 if (SEQ_GT(tp->snd_una, th_ack)) { 5228 snd_una = tp->snd_una; 5229 } else { 5230 snd_una = th_ack; 5231 } 5232 pipe = ((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt; 5233 if (pipe > tp->snd_ssthresh) { 5234 long sndcnt; 5235 5236 sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh; 5237 if (rack->r_ctl.rc_prr_recovery_fs > 0) 5238 sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs; 5239 else { 5240 rack->r_ctl.rc_prr_sndcnt = 0; 5241 rack_log_to_prr(rack, 9); 5242 sndcnt = 0; 5243 } 5244 sndcnt++; 5245 if (sndcnt > (long)rack->r_ctl.rc_prr_out) 5246 sndcnt -= rack->r_ctl.rc_prr_out; 5247 else 5248 sndcnt = 0; 5249 rack->r_ctl.rc_prr_sndcnt = sndcnt; 5250 rack_log_to_prr(rack, 10); 5251 } else { 5252 uint32_t limit; 5253 5254 if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out) 5255 limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out); 5256 else 5257 limit = 0; 5258 if (changed > limit) 5259 limit = changed; 5260 limit += ctf_fixed_maxseg(tp); 5261 if (tp->snd_ssthresh > pipe) { 5262 rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit); 5263 rack_log_to_prr(rack, 11); 5264 } else { 5265 rack->r_ctl.rc_prr_sndcnt = min(0, limit); 5266 rack_log_to_prr(rack, 12); 5267 } 5268 } 5269 if (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) { 5270 rack->r_timer_override = 1; 5271 } 5272 } 5273 } 5274 5275 static void 5276 rack_strike_dupack(struct tcp_rack *rack) 5277 { 5278 struct rack_sendmap *rsm; 5279 5280 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 5281 if (rsm && (rsm->r_dupack < 0xff)) { 5282 rsm->r_dupack++; 5283 if (rsm->r_dupack >= DUP_ACK_THRESHOLD) { 5284 rack->r_wanted_output = 1; 5285 rack_log_retran_reason(rack, rsm, __LINE__, 1, 3); 5286 } else { 5287 rack_log_retran_reason(rack, rsm, __LINE__, 0, 3); 5288 } 5289 } 5290 } 5291 5292 /* 5293 * Return value of 1, we do not need to call rack_process_data(). 5294 * return value of 0, rack_process_data can be called. 5295 * For ret_val if its 0 the TCP is locked, if its non-zero 5296 * its unlocked and probably unsafe to touch the TCB. 5297 */ 5298 static int 5299 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so, 5300 struct tcpcb *tp, struct tcpopt *to, 5301 uint32_t tiwin, int32_t tlen, 5302 int32_t * ofia, int32_t thflags, int32_t * ret_val) 5303 { 5304 int32_t ourfinisacked = 0; 5305 int32_t nsegs, acked_amount; 5306 int32_t acked; 5307 struct mbuf *mfree; 5308 struct tcp_rack *rack; 5309 int32_t recovery = 0; 5310 5311 rack = (struct tcp_rack *)tp->t_fb_ptr; 5312 if (SEQ_GT(th->th_ack, tp->snd_max)) { 5313 ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val); 5314 rack->r_wanted_output++; 5315 return (1); 5316 } 5317 if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) { 5318 if (rack->rc_in_persist) 5319 tp->t_rxtshift = 0; 5320 if ((th->th_ack == tp->snd_una) && (tiwin == tp->snd_wnd)) 5321 rack_strike_dupack(rack); 5322 rack_log_ack(tp, to, th); 5323 } 5324 if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) { 5325 /* 5326 * Old ack, behind (or duplicate to) the last one rcv'd 5327 * Note: Should mark reordering is occuring! We should also 5328 * look for sack blocks arriving e.g. ack 1, 4-4 then ack 1, 5329 * 3-3, 4-4 would be reording. As well as ack 1, 3-3 <no 5330 * retran and> ack 3 5331 */ 5332 return (0); 5333 } 5334 /* 5335 * If we reach this point, ACK is not a duplicate, i.e., it ACKs 5336 * something we sent. 5337 */ 5338 if (tp->t_flags & TF_NEEDSYN) { 5339 /* 5340 * T/TCP: Connection was half-synchronized, and our SYN has 5341 * been ACK'd (so connection is now fully synchronized). Go 5342 * to non-starred state, increment snd_una for ACK of SYN, 5343 * and check if we can do window scaling. 5344 */ 5345 tp->t_flags &= ~TF_NEEDSYN; 5346 tp->snd_una++; 5347 /* Do window scaling? */ 5348 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) == 5349 (TF_RCVD_SCALE | TF_REQ_SCALE)) { 5350 tp->rcv_scale = tp->request_r_scale; 5351 /* Send window already scaled. */ 5352 } 5353 } 5354 nsegs = max(1, m->m_pkthdr.lro_nsegs); 5355 INP_WLOCK_ASSERT(tp->t_inpcb); 5356 5357 acked = BYTES_THIS_ACK(tp, th); 5358 KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs); 5359 KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked); 5360 5361 /* 5362 * If we just performed our first retransmit, and the ACK arrives 5363 * within our recovery window, then it was a mistake to do the 5364 * retransmit in the first place. Recover our original cwnd and 5365 * ssthresh, and proceed to transmit where we left off. 5366 */ 5367 if (tp->t_flags & TF_PREVVALID) { 5368 tp->t_flags &= ~TF_PREVVALID; 5369 if (tp->t_rxtshift == 1 && 5370 (int)(ticks - tp->t_badrxtwin) < 0) 5371 rack_cong_signal(tp, th, CC_RTO_ERR); 5372 } 5373 /* 5374 * If we have a timestamp reply, update smoothed round trip time. If 5375 * no timestamp is present but transmit timer is running and timed 5376 * sequence number was acked, update smoothed round trip time. Since 5377 * we now have an rtt measurement, cancel the timer backoff (cf., 5378 * Phil Karn's retransmit alg.). Recompute the initial retransmit 5379 * timer. 5380 * 5381 * Some boxes send broken timestamp replies during the SYN+ACK 5382 * phase, ignore timestamps of 0 or we could calculate a huge RTT 5383 * and blow up the retransmit timer. 5384 */ 5385 /* 5386 * If all outstanding data is acked, stop retransmit timer and 5387 * remember to restart (more output or persist). If there is more 5388 * data to be acked, restart retransmit timer, using current 5389 * (possibly backed-off) value. 5390 */ 5391 if (th->th_ack == tp->snd_max) { 5392 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 5393 rack->r_wanted_output++; 5394 } 5395 if (acked == 0) { 5396 if (ofia) 5397 *ofia = ourfinisacked; 5398 return (0); 5399 } 5400 if (rack->r_ctl.rc_early_recovery) { 5401 if (IN_RECOVERY(tp->t_flags)) { 5402 if (SEQ_LT(th->th_ack, tp->snd_recover) && 5403 (SEQ_LT(th->th_ack, tp->snd_max))) { 5404 tcp_rack_partialack(tp, th); 5405 } else { 5406 rack_post_recovery(tp, th); 5407 recovery = 1; 5408 } 5409 } 5410 } 5411 /* 5412 * Let the congestion control algorithm update congestion control 5413 * related information. This typically means increasing the 5414 * congestion window. 5415 */ 5416 rack_ack_received(tp, rack, th, nsegs, CC_ACK, recovery); 5417 SOCKBUF_LOCK(&so->so_snd); 5418 acked_amount = min(acked, (int)sbavail(&so->so_snd)); 5419 tp->snd_wnd -= acked_amount; 5420 mfree = sbcut_locked(&so->so_snd, acked_amount); 5421 if ((sbused(&so->so_snd) == 0) && 5422 (acked > acked_amount) && 5423 (tp->t_state >= TCPS_FIN_WAIT_1)) { 5424 ourfinisacked = 1; 5425 } 5426 /* NB: sowwakeup_locked() does an implicit unlock. */ 5427 sowwakeup_locked(so); 5428 m_freem(mfree); 5429 if (rack->r_ctl.rc_early_recovery == 0) { 5430 if (IN_RECOVERY(tp->t_flags)) { 5431 if (SEQ_LT(th->th_ack, tp->snd_recover) && 5432 (SEQ_LT(th->th_ack, tp->snd_max))) { 5433 tcp_rack_partialack(tp, th); 5434 } else { 5435 rack_post_recovery(tp, th); 5436 } 5437 } 5438 } 5439 tp->snd_una = th->th_ack; 5440 if (SEQ_GT(tp->snd_una, tp->snd_recover)) 5441 tp->snd_recover = tp->snd_una; 5442 5443 if (SEQ_LT(tp->snd_nxt, tp->snd_una)) { 5444 tp->snd_nxt = tp->snd_una; 5445 } 5446 if (tp->snd_una == tp->snd_max) { 5447 /* Nothing left outstanding */ 5448 rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__); 5449 if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0) 5450 tp->t_acktime = 0; 5451 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 5452 /* Set need output so persist might get set */ 5453 rack->r_wanted_output++; 5454 if (rack_use_sack_filter) 5455 sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una); 5456 if ((tp->t_state >= TCPS_FIN_WAIT_1) && 5457 (sbavail(&so->so_snd) == 0) && 5458 (tp->t_flags2 & TF2_DROP_AF_DATA)) { 5459 /* 5460 * The socket was gone and the 5461 * peer sent data, time to 5462 * reset him. 5463 */ 5464 *ret_val = 1; 5465 tp = tcp_close(tp); 5466 ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen); 5467 return (1); 5468 } 5469 } 5470 if (ofia) 5471 *ofia = ourfinisacked; 5472 return (0); 5473 } 5474 5475 static void 5476 rack_collapsed_window(struct tcp_rack *rack) 5477 { 5478 /* 5479 * Now we must walk the 5480 * send map and divide the 5481 * ones left stranded. These 5482 * guys can't cause us to abort 5483 * the connection and are really 5484 * "unsent". However if a buggy 5485 * client actually did keep some 5486 * of the data i.e. collapsed the win 5487 * and refused to ack and then opened 5488 * the win and acked that data. We would 5489 * get into an ack war, the simplier 5490 * method then of just pretending we 5491 * did not send those segments something 5492 * won't work. 5493 */ 5494 struct rack_sendmap *rsm, *nrsm, fe, *insret; 5495 tcp_seq max_seq; 5496 uint32_t maxseg; 5497 5498 max_seq = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd; 5499 maxseg = ctf_fixed_maxseg(rack->rc_tp); 5500 memset(&fe, 0, sizeof(fe)); 5501 fe.r_start = max_seq; 5502 /* Find the first seq past or at maxseq */ 5503 rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe); 5504 if (rsm == NULL) { 5505 /* Nothing to do strange */ 5506 rack->rc_has_collapsed = 0; 5507 return; 5508 } 5509 /* 5510 * Now do we need to split at 5511 * the collapse point? 5512 */ 5513 if (SEQ_GT(max_seq, rsm->r_start)) { 5514 nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT); 5515 if (nrsm == NULL) { 5516 /* We can't get a rsm, mark all? */ 5517 nrsm = rsm; 5518 goto no_split; 5519 } 5520 /* Clone it */ 5521 rack_clone_rsm(rack, nrsm, rsm, max_seq); 5522 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm); 5523 #ifdef INVARIANTS 5524 if (insret != NULL) { 5525 panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p", 5526 nrsm, insret, rack, rsm); 5527 } 5528 #endif 5529 if (rsm->r_in_tmap) { 5530 TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext); 5531 nrsm->r_in_tmap = 1; 5532 } 5533 /* 5534 * Set in the new RSM as the 5535 * collapsed starting point 5536 */ 5537 rsm = nrsm; 5538 } 5539 no_split: 5540 counter_u64_add(rack_collapsed_win, 1); 5541 RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) { 5542 nrsm->r_flags |= RACK_RWND_COLLAPSED; 5543 rack->rc_has_collapsed = 1; 5544 } 5545 } 5546 5547 static void 5548 rack_un_collapse_window(struct tcp_rack *rack) 5549 { 5550 struct rack_sendmap *rsm; 5551 5552 RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) { 5553 if (rsm->r_flags & RACK_RWND_COLLAPSED) 5554 rsm->r_flags &= ~RACK_RWND_COLLAPSED; 5555 else 5556 break; 5557 } 5558 rack->rc_has_collapsed = 0; 5559 } 5560 5561 /* 5562 * Return value of 1, the TCB is unlocked and most 5563 * likely gone, return value of 0, the TCP is still 5564 * locked. 5565 */ 5566 static int 5567 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so, 5568 struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, 5569 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt) 5570 { 5571 /* 5572 * Update window information. Don't look at window if no ACK: TAC's 5573 * send garbage on first SYN. 5574 */ 5575 int32_t nsegs; 5576 int32_t tfo_syn; 5577 struct tcp_rack *rack; 5578 5579 rack = (struct tcp_rack *)tp->t_fb_ptr; 5580 INP_WLOCK_ASSERT(tp->t_inpcb); 5581 nsegs = max(1, m->m_pkthdr.lro_nsegs); 5582 if ((thflags & TH_ACK) && 5583 (SEQ_LT(tp->snd_wl1, th->th_seq) || 5584 (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) || 5585 (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) { 5586 /* keep track of pure window updates */ 5587 if (tlen == 0 && 5588 tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd) 5589 KMOD_TCPSTAT_INC(tcps_rcvwinupd); 5590 tp->snd_wnd = tiwin; 5591 tp->snd_wl1 = th->th_seq; 5592 tp->snd_wl2 = th->th_ack; 5593 if (tp->snd_wnd > tp->max_sndwnd) 5594 tp->max_sndwnd = tp->snd_wnd; 5595 rack->r_wanted_output++; 5596 } else if (thflags & TH_ACK) { 5597 if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) { 5598 tp->snd_wnd = tiwin; 5599 tp->snd_wl1 = th->th_seq; 5600 tp->snd_wl2 = th->th_ack; 5601 } 5602 } 5603 if (tp->snd_wnd < ctf_outstanding(tp)) 5604 /* The peer collapsed the window */ 5605 rack_collapsed_window(rack); 5606 else if (rack->rc_has_collapsed) 5607 rack_un_collapse_window(rack); 5608 /* Was persist timer active and now we have window space? */ 5609 if ((rack->rc_in_persist != 0) && 5610 (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2), 5611 rack->r_ctl.rc_pace_min_segs))) { 5612 rack_exit_persist(tp, rack); 5613 tp->snd_nxt = tp->snd_max; 5614 /* Make sure we output to start the timer */ 5615 rack->r_wanted_output++; 5616 } 5617 /* Do we enter persists? */ 5618 if ((rack->rc_in_persist == 0) && 5619 (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) && 5620 TCPS_HAVEESTABLISHED(tp->t_state) && 5621 (tp->snd_max == tp->snd_una) && 5622 sbavail(&tp->t_inpcb->inp_socket->so_snd) && 5623 (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) { 5624 /* 5625 * Here the rwnd is less than 5626 * the pacing size, we are established, 5627 * nothing is outstanding, and there is 5628 * data to send. Enter persists. 5629 */ 5630 tp->snd_nxt = tp->snd_una; 5631 rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime); 5632 } 5633 if (tp->t_flags2 & TF2_DROP_AF_DATA) { 5634 m_freem(m); 5635 return (0); 5636 } 5637 /* 5638 * Process segments with URG. 5639 */ 5640 if ((thflags & TH_URG) && th->th_urp && 5641 TCPS_HAVERCVDFIN(tp->t_state) == 0) { 5642 /* 5643 * This is a kludge, but if we receive and accept random 5644 * urgent pointers, we'll crash in soreceive. It's hard to 5645 * imagine someone actually wanting to send this much urgent 5646 * data. 5647 */ 5648 SOCKBUF_LOCK(&so->so_rcv); 5649 if (th->th_urp + sbavail(&so->so_rcv) > sb_max) { 5650 th->th_urp = 0; /* XXX */ 5651 thflags &= ~TH_URG; /* XXX */ 5652 SOCKBUF_UNLOCK(&so->so_rcv); /* XXX */ 5653 goto dodata; /* XXX */ 5654 } 5655 /* 5656 * If this segment advances the known urgent pointer, then 5657 * mark the data stream. This should not happen in 5658 * CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since a 5659 * FIN has been received from the remote side. In these 5660 * states we ignore the URG. 5661 * 5662 * According to RFC961 (Assigned Protocols), the urgent 5663 * pointer points to the last octet of urgent data. We 5664 * continue, however, to consider it to indicate the first 5665 * octet of data past the urgent section as the original 5666 * spec states (in one of two places). 5667 */ 5668 if (SEQ_GT(th->th_seq + th->th_urp, tp->rcv_up)) { 5669 tp->rcv_up = th->th_seq + th->th_urp; 5670 so->so_oobmark = sbavail(&so->so_rcv) + 5671 (tp->rcv_up - tp->rcv_nxt) - 1; 5672 if (so->so_oobmark == 0) 5673 so->so_rcv.sb_state |= SBS_RCVATMARK; 5674 sohasoutofband(so); 5675 tp->t_oobflags &= ~(TCPOOB_HAVEDATA | TCPOOB_HADDATA); 5676 } 5677 SOCKBUF_UNLOCK(&so->so_rcv); 5678 /* 5679 * Remove out of band data so doesn't get presented to user. 5680 * This can happen independent of advancing the URG pointer, 5681 * but if two URG's are pending at once, some out-of-band 5682 * data may creep in... ick. 5683 */ 5684 if (th->th_urp <= (uint32_t) tlen && 5685 !(so->so_options & SO_OOBINLINE)) { 5686 /* hdr drop is delayed */ 5687 tcp_pulloutofband(so, th, m, drop_hdrlen); 5688 } 5689 } else { 5690 /* 5691 * If no out of band data is expected, pull receive urgent 5692 * pointer along with the receive window. 5693 */ 5694 if (SEQ_GT(tp->rcv_nxt, tp->rcv_up)) 5695 tp->rcv_up = tp->rcv_nxt; 5696 } 5697 dodata: /* XXX */ 5698 INP_WLOCK_ASSERT(tp->t_inpcb); 5699 5700 /* 5701 * Process the segment text, merging it into the TCP sequencing 5702 * queue, and arranging for acknowledgment of receipt if necessary. 5703 * This process logically involves adjusting tp->rcv_wnd as data is 5704 * presented to the user (this happens in tcp_usrreq.c, case 5705 * PRU_RCVD). If a FIN has already been received on this connection 5706 * then we just ignore the text. 5707 */ 5708 tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) && 5709 IS_FASTOPEN(tp->t_flags)); 5710 if ((tlen || (thflags & TH_FIN) || tfo_syn) && 5711 TCPS_HAVERCVDFIN(tp->t_state) == 0) { 5712 tcp_seq save_start = th->th_seq; 5713 tcp_seq save_rnxt = tp->rcv_nxt; 5714 int save_tlen = tlen; 5715 5716 m_adj(m, drop_hdrlen); /* delayed header drop */ 5717 /* 5718 * Insert segment which includes th into TCP reassembly 5719 * queue with control block tp. Set thflags to whether 5720 * reassembly now includes a segment with FIN. This handles 5721 * the common case inline (segment is the next to be 5722 * received on an established connection, and the queue is 5723 * empty), avoiding linkage into and removal from the queue 5724 * and repetition of various conversions. Set DELACK for 5725 * segments received in order, but ack immediately when 5726 * segments are out of order (so fast retransmit can work). 5727 */ 5728 if (th->th_seq == tp->rcv_nxt && 5729 SEGQ_EMPTY(tp) && 5730 (TCPS_HAVEESTABLISHED(tp->t_state) || 5731 tfo_syn)) { 5732 #ifdef NETFLIX_SB_LIMITS 5733 u_int mcnt, appended; 5734 5735 if (so->so_rcv.sb_shlim) { 5736 mcnt = m_memcnt(m); 5737 appended = 0; 5738 if (counter_fo_get(so->so_rcv.sb_shlim, mcnt, 5739 CFO_NOSLEEP, NULL) == false) { 5740 counter_u64_add(tcp_sb_shlim_fails, 1); 5741 m_freem(m); 5742 return (0); 5743 } 5744 } 5745 #endif 5746 if (DELAY_ACK(tp, tlen) || tfo_syn) { 5747 rack_timer_cancel(tp, rack, 5748 rack->r_ctl.rc_rcvtime, __LINE__); 5749 tp->t_flags |= TF_DELACK; 5750 } else { 5751 rack->r_wanted_output++; 5752 tp->t_flags |= TF_ACKNOW; 5753 } 5754 tp->rcv_nxt += tlen; 5755 thflags = th->th_flags & TH_FIN; 5756 KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs); 5757 KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen); 5758 SOCKBUF_LOCK(&so->so_rcv); 5759 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 5760 m_freem(m); 5761 } else 5762 #ifdef NETFLIX_SB_LIMITS 5763 appended = 5764 #endif 5765 sbappendstream_locked(&so->so_rcv, m, 0); 5766 /* NB: sorwakeup_locked() does an implicit unlock. */ 5767 sorwakeup_locked(so); 5768 #ifdef NETFLIX_SB_LIMITS 5769 if (so->so_rcv.sb_shlim && appended != mcnt) 5770 counter_fo_release(so->so_rcv.sb_shlim, 5771 mcnt - appended); 5772 #endif 5773 } else { 5774 /* 5775 * XXX: Due to the header drop above "th" is 5776 * theoretically invalid by now. Fortunately 5777 * m_adj() doesn't actually frees any mbufs when 5778 * trimming from the head. 5779 */ 5780 tcp_seq temp = save_start; 5781 thflags = tcp_reass(tp, th, &temp, &tlen, m); 5782 tp->t_flags |= TF_ACKNOW; 5783 } 5784 if ((tp->t_flags & TF_SACK_PERMIT) && (save_tlen > 0)) { 5785 if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) { 5786 /* 5787 * DSACK actually handled in the fastpath 5788 * above. 5789 */ 5790 tcp_update_sack_list(tp, save_start, 5791 save_start + save_tlen); 5792 } else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) { 5793 if ((tp->rcv_numsacks >= 1) && 5794 (tp->sackblks[0].end == save_start)) { 5795 /* 5796 * Partial overlap, recorded at todrop 5797 * above. 5798 */ 5799 tcp_update_sack_list(tp, 5800 tp->sackblks[0].start, 5801 tp->sackblks[0].end); 5802 } else { 5803 tcp_update_dsack_list(tp, save_start, 5804 save_start + save_tlen); 5805 } 5806 } else if (tlen >= save_tlen) { 5807 /* Update of sackblks. */ 5808 tcp_update_dsack_list(tp, save_start, 5809 save_start + save_tlen); 5810 } else if (tlen > 0) { 5811 tcp_update_dsack_list(tp, save_start, 5812 save_start + tlen); 5813 } 5814 } 5815 } else { 5816 m_freem(m); 5817 thflags &= ~TH_FIN; 5818 } 5819 5820 /* 5821 * If FIN is received ACK the FIN and let the user know that the 5822 * connection is closing. 5823 */ 5824 if (thflags & TH_FIN) { 5825 if (TCPS_HAVERCVDFIN(tp->t_state) == 0) { 5826 socantrcvmore(so); 5827 /* 5828 * If connection is half-synchronized (ie NEEDSYN 5829 * flag on) then delay ACK, so it may be piggybacked 5830 * when SYN is sent. Otherwise, since we received a 5831 * FIN then no more input can be expected, send ACK 5832 * now. 5833 */ 5834 if (tp->t_flags & TF_NEEDSYN) { 5835 rack_timer_cancel(tp, rack, 5836 rack->r_ctl.rc_rcvtime, __LINE__); 5837 tp->t_flags |= TF_DELACK; 5838 } else { 5839 tp->t_flags |= TF_ACKNOW; 5840 } 5841 tp->rcv_nxt++; 5842 } 5843 switch (tp->t_state) { 5844 5845 /* 5846 * In SYN_RECEIVED and ESTABLISHED STATES enter the 5847 * CLOSE_WAIT state. 5848 */ 5849 case TCPS_SYN_RECEIVED: 5850 tp->t_starttime = ticks; 5851 /* FALLTHROUGH */ 5852 case TCPS_ESTABLISHED: 5853 rack_timer_cancel(tp, rack, 5854 rack->r_ctl.rc_rcvtime, __LINE__); 5855 tcp_state_change(tp, TCPS_CLOSE_WAIT); 5856 break; 5857 5858 /* 5859 * If still in FIN_WAIT_1 STATE FIN has not been 5860 * acked so enter the CLOSING state. 5861 */ 5862 case TCPS_FIN_WAIT_1: 5863 rack_timer_cancel(tp, rack, 5864 rack->r_ctl.rc_rcvtime, __LINE__); 5865 tcp_state_change(tp, TCPS_CLOSING); 5866 break; 5867 5868 /* 5869 * In FIN_WAIT_2 state enter the TIME_WAIT state, 5870 * starting the time-wait timer, turning off the 5871 * other standard timers. 5872 */ 5873 case TCPS_FIN_WAIT_2: 5874 rack_timer_cancel(tp, rack, 5875 rack->r_ctl.rc_rcvtime, __LINE__); 5876 tcp_twstart(tp); 5877 return (1); 5878 } 5879 } 5880 /* 5881 * Return any desired output. 5882 */ 5883 if ((tp->t_flags & TF_ACKNOW) || 5884 (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) { 5885 rack->r_wanted_output++; 5886 } 5887 INP_WLOCK_ASSERT(tp->t_inpcb); 5888 return (0); 5889 } 5890 5891 /* 5892 * Here nothing is really faster, its just that we 5893 * have broken out the fast-data path also just like 5894 * the fast-ack. 5895 */ 5896 static int 5897 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so, 5898 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 5899 uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos) 5900 { 5901 int32_t nsegs; 5902 int32_t newsize = 0; /* automatic sockbuf scaling */ 5903 struct tcp_rack *rack; 5904 #ifdef NETFLIX_SB_LIMITS 5905 u_int mcnt, appended; 5906 #endif 5907 #ifdef TCPDEBUG 5908 /* 5909 * The size of tcp_saveipgen must be the size of the max ip header, 5910 * now IPv6. 5911 */ 5912 u_char tcp_saveipgen[IP6_HDR_LEN]; 5913 struct tcphdr tcp_savetcp; 5914 short ostate = 0; 5915 5916 #endif 5917 /* 5918 * If last ACK falls within this segment's sequence numbers, record 5919 * the timestamp. NOTE that the test is modified according to the 5920 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26). 5921 */ 5922 if (__predict_false(th->th_seq != tp->rcv_nxt)) { 5923 return (0); 5924 } 5925 if (__predict_false(tp->snd_nxt != tp->snd_max)) { 5926 return (0); 5927 } 5928 if (tiwin && tiwin != tp->snd_wnd) { 5929 return (0); 5930 } 5931 if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) { 5932 return (0); 5933 } 5934 if (__predict_false((to->to_flags & TOF_TS) && 5935 (TSTMP_LT(to->to_tsval, tp->ts_recent)))) { 5936 return (0); 5937 } 5938 if (__predict_false((th->th_ack != tp->snd_una))) { 5939 return (0); 5940 } 5941 if (__predict_false(tlen > sbspace(&so->so_rcv))) { 5942 return (0); 5943 } 5944 if ((to->to_flags & TOF_TS) != 0 && 5945 SEQ_LEQ(th->th_seq, tp->last_ack_sent)) { 5946 tp->ts_recent_age = tcp_ts_getticks(); 5947 tp->ts_recent = to->to_tsval; 5948 } 5949 rack = (struct tcp_rack *)tp->t_fb_ptr; 5950 /* 5951 * This is a pure, in-sequence data packet with nothing on the 5952 * reassembly queue and we have enough buffer space to take it. 5953 */ 5954 nsegs = max(1, m->m_pkthdr.lro_nsegs); 5955 5956 #ifdef NETFLIX_SB_LIMITS 5957 if (so->so_rcv.sb_shlim) { 5958 mcnt = m_memcnt(m); 5959 appended = 0; 5960 if (counter_fo_get(so->so_rcv.sb_shlim, mcnt, 5961 CFO_NOSLEEP, NULL) == false) { 5962 counter_u64_add(tcp_sb_shlim_fails, 1); 5963 m_freem(m); 5964 return (1); 5965 } 5966 } 5967 #endif 5968 /* Clean receiver SACK report if present */ 5969 if (tp->rcv_numsacks) 5970 tcp_clean_sackreport(tp); 5971 KMOD_TCPSTAT_INC(tcps_preddat); 5972 tp->rcv_nxt += tlen; 5973 /* 5974 * Pull snd_wl1 up to prevent seq wrap relative to th_seq. 5975 */ 5976 tp->snd_wl1 = th->th_seq; 5977 /* 5978 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt. 5979 */ 5980 tp->rcv_up = tp->rcv_nxt; 5981 KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs); 5982 KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen); 5983 #ifdef TCPDEBUG 5984 if (so->so_options & SO_DEBUG) 5985 tcp_trace(TA_INPUT, ostate, tp, 5986 (void *)tcp_saveipgen, &tcp_savetcp, 0); 5987 #endif 5988 newsize = tcp_autorcvbuf(m, th, so, tp, tlen); 5989 5990 /* Add data to socket buffer. */ 5991 SOCKBUF_LOCK(&so->so_rcv); 5992 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 5993 m_freem(m); 5994 } else { 5995 /* 5996 * Set new socket buffer size. Give up when limit is 5997 * reached. 5998 */ 5999 if (newsize) 6000 if (!sbreserve_locked(&so->so_rcv, 6001 newsize, so, NULL)) 6002 so->so_rcv.sb_flags &= ~SB_AUTOSIZE; 6003 m_adj(m, drop_hdrlen); /* delayed header drop */ 6004 #ifdef NETFLIX_SB_LIMITS 6005 appended = 6006 #endif 6007 sbappendstream_locked(&so->so_rcv, m, 0); 6008 ctf_calc_rwin(so, tp); 6009 } 6010 /* NB: sorwakeup_locked() does an implicit unlock. */ 6011 sorwakeup_locked(so); 6012 #ifdef NETFLIX_SB_LIMITS 6013 if (so->so_rcv.sb_shlim && mcnt != appended) 6014 counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended); 6015 #endif 6016 if (DELAY_ACK(tp, tlen)) { 6017 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 6018 tp->t_flags |= TF_DELACK; 6019 } else { 6020 tp->t_flags |= TF_ACKNOW; 6021 rack->r_wanted_output++; 6022 } 6023 if ((tp->snd_una == tp->snd_max) && rack_use_sack_filter) 6024 sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una); 6025 return (1); 6026 } 6027 6028 /* 6029 * This subfunction is used to try to highly optimize the 6030 * fast path. We again allow window updates that are 6031 * in sequence to remain in the fast-path. We also add 6032 * in the __predict's to attempt to help the compiler. 6033 * Note that if we return a 0, then we can *not* process 6034 * it and the caller should push the packet into the 6035 * slow-path. 6036 */ 6037 static int 6038 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so, 6039 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6040 uint32_t tiwin, int32_t nxt_pkt, uint32_t cts, uint8_t iptos) 6041 { 6042 int32_t acked; 6043 int32_t nsegs; 6044 6045 #ifdef TCPDEBUG 6046 /* 6047 * The size of tcp_saveipgen must be the size of the max ip header, 6048 * now IPv6. 6049 */ 6050 u_char tcp_saveipgen[IP6_HDR_LEN]; 6051 struct tcphdr tcp_savetcp; 6052 short ostate = 0; 6053 6054 #endif 6055 struct tcp_rack *rack; 6056 6057 if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) { 6058 /* Old ack, behind (or duplicate to) the last one rcv'd */ 6059 return (0); 6060 } 6061 if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) { 6062 /* Above what we have sent? */ 6063 return (0); 6064 } 6065 if (__predict_false(tp->snd_nxt != tp->snd_max)) { 6066 /* We are retransmitting */ 6067 return (0); 6068 } 6069 if (__predict_false(tiwin == 0)) { 6070 /* zero window */ 6071 return (0); 6072 } 6073 if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) { 6074 /* We need a SYN or a FIN, unlikely.. */ 6075 return (0); 6076 } 6077 if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) { 6078 /* Timestamp is behind .. old ack with seq wrap? */ 6079 return (0); 6080 } 6081 if (__predict_false(IN_RECOVERY(tp->t_flags))) { 6082 /* Still recovering */ 6083 return (0); 6084 } 6085 rack = (struct tcp_rack *)tp->t_fb_ptr; 6086 if (rack->r_ctl.rc_sacked) { 6087 /* We have sack holes on our scoreboard */ 6088 return (0); 6089 } 6090 /* Ok if we reach here, we can process a fast-ack */ 6091 nsegs = max(1, m->m_pkthdr.lro_nsegs); 6092 rack_log_ack(tp, to, th); 6093 /* 6094 * We made progress, clear the tlp 6095 * out flag so we could start a TLP 6096 * again. 6097 */ 6098 rack->r_ctl.rc_tlp_rtx_out = 0; 6099 /* Did the window get updated? */ 6100 if (tiwin != tp->snd_wnd) { 6101 tp->snd_wnd = tiwin; 6102 tp->snd_wl1 = th->th_seq; 6103 if (tp->snd_wnd > tp->max_sndwnd) 6104 tp->max_sndwnd = tp->snd_wnd; 6105 } 6106 /* Do we exit persists? */ 6107 if ((rack->rc_in_persist != 0) && 6108 (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2), 6109 rack->r_ctl.rc_pace_min_segs))) { 6110 rack_exit_persist(tp, rack); 6111 } 6112 /* Do we enter persists? */ 6113 if ((rack->rc_in_persist == 0) && 6114 (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) && 6115 TCPS_HAVEESTABLISHED(tp->t_state) && 6116 (tp->snd_max == tp->snd_una) && 6117 sbavail(&tp->t_inpcb->inp_socket->so_snd) && 6118 (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) { 6119 /* 6120 * Here the rwnd is less than 6121 * the pacing size, we are established, 6122 * nothing is outstanding, and there is 6123 * data to send. Enter persists. 6124 */ 6125 tp->snd_nxt = tp->snd_una; 6126 rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime); 6127 } 6128 /* 6129 * If last ACK falls within this segment's sequence numbers, record 6130 * the timestamp. NOTE that the test is modified according to the 6131 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26). 6132 */ 6133 if ((to->to_flags & TOF_TS) != 0 && 6134 SEQ_LEQ(th->th_seq, tp->last_ack_sent)) { 6135 tp->ts_recent_age = tcp_ts_getticks(); 6136 tp->ts_recent = to->to_tsval; 6137 } 6138 /* 6139 * This is a pure ack for outstanding data. 6140 */ 6141 KMOD_TCPSTAT_INC(tcps_predack); 6142 6143 /* 6144 * "bad retransmit" recovery. 6145 */ 6146 if (tp->t_flags & TF_PREVVALID) { 6147 tp->t_flags &= ~TF_PREVVALID; 6148 if (tp->t_rxtshift == 1 && 6149 (int)(ticks - tp->t_badrxtwin) < 0) 6150 rack_cong_signal(tp, th, CC_RTO_ERR); 6151 } 6152 /* 6153 * Recalculate the transmit timer / rtt. 6154 * 6155 * Some boxes send broken timestamp replies during the SYN+ACK 6156 * phase, ignore timestamps of 0 or we could calculate a huge RTT 6157 * and blow up the retransmit timer. 6158 */ 6159 acked = BYTES_THIS_ACK(tp, th); 6160 6161 #ifdef TCP_HHOOK 6162 /* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */ 6163 hhook_run_tcp_est_in(tp, th, to); 6164 #endif 6165 6166 KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs); 6167 KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked); 6168 sbdrop(&so->so_snd, acked); 6169 /* 6170 * Let the congestion control algorithm update congestion control 6171 * related information. This typically means increasing the 6172 * congestion window. 6173 */ 6174 rack_ack_received(tp, rack, th, nsegs, CC_ACK, 0); 6175 6176 tp->snd_una = th->th_ack; 6177 if (tp->snd_wnd < ctf_outstanding(tp)) { 6178 /* The peer collapsed the window */ 6179 rack_collapsed_window(rack); 6180 } else if (rack->rc_has_collapsed) 6181 rack_un_collapse_window(rack); 6182 6183 /* 6184 * Pull snd_wl2 up to prevent seq wrap relative to th_ack. 6185 */ 6186 tp->snd_wl2 = th->th_ack; 6187 tp->t_dupacks = 0; 6188 m_freem(m); 6189 /* ND6_HINT(tp); *//* Some progress has been made. */ 6190 6191 /* 6192 * If all outstanding data are acked, stop retransmit timer, 6193 * otherwise restart timer using current (possibly backed-off) 6194 * value. If process is waiting for space, wakeup/selwakeup/signal. 6195 * If data are ready to send, let tcp_output decide between more 6196 * output or persist. 6197 */ 6198 #ifdef TCPDEBUG 6199 if (so->so_options & SO_DEBUG) 6200 tcp_trace(TA_INPUT, ostate, tp, 6201 (void *)tcp_saveipgen, 6202 &tcp_savetcp, 0); 6203 #endif 6204 if (tp->snd_una == tp->snd_max) { 6205 rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__); 6206 if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0) 6207 tp->t_acktime = 0; 6208 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 6209 } 6210 /* Wake up the socket if we have room to write more */ 6211 sowwakeup(so); 6212 if (sbavail(&so->so_snd)) { 6213 rack->r_wanted_output++; 6214 } 6215 return (1); 6216 } 6217 6218 /* 6219 * Return value of 1, the TCB is unlocked and most 6220 * likely gone, return value of 0, the TCP is still 6221 * locked. 6222 */ 6223 static int 6224 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so, 6225 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6226 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t tos) 6227 { 6228 int32_t ret_val = 0; 6229 int32_t todrop; 6230 int32_t ourfinisacked = 0; 6231 struct tcp_rack *rack; 6232 6233 ctf_calc_rwin(so, tp); 6234 /* 6235 * If the state is SYN_SENT: if seg contains an ACK, but not for our 6236 * SYN, drop the input. if seg contains a RST, then drop the 6237 * connection. if seg does not contain SYN, then drop it. Otherwise 6238 * this is an acceptable SYN segment initialize tp->rcv_nxt and 6239 * tp->irs if seg contains ack then advance tp->snd_una if seg 6240 * contains an ECE and ECN support is enabled, the stream is ECN 6241 * capable. if SYN has been acked change to ESTABLISHED else 6242 * SYN_RCVD state arrange for segment to be acked (eventually) 6243 * continue processing rest of data/controls, beginning with URG 6244 */ 6245 if ((thflags & TH_ACK) && 6246 (SEQ_LEQ(th->th_ack, tp->iss) || 6247 SEQ_GT(th->th_ack, tp->snd_max))) { 6248 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6249 return (1); 6250 } 6251 if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) { 6252 TCP_PROBE5(connect__refused, NULL, tp, 6253 mtod(m, const char *), tp, th); 6254 tp = tcp_drop(tp, ECONNREFUSED); 6255 ctf_do_drop(m, tp); 6256 return (1); 6257 } 6258 if (thflags & TH_RST) { 6259 ctf_do_drop(m, tp); 6260 return (1); 6261 } 6262 if (!(thflags & TH_SYN)) { 6263 ctf_do_drop(m, tp); 6264 return (1); 6265 } 6266 tp->irs = th->th_seq; 6267 tcp_rcvseqinit(tp); 6268 rack = (struct tcp_rack *)tp->t_fb_ptr; 6269 if (thflags & TH_ACK) { 6270 int tfo_partial = 0; 6271 6272 KMOD_TCPSTAT_INC(tcps_connects); 6273 soisconnected(so); 6274 #ifdef MAC 6275 mac_socketpeer_set_from_mbuf(m, so); 6276 #endif 6277 /* Do window scaling on this connection? */ 6278 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) == 6279 (TF_RCVD_SCALE | TF_REQ_SCALE)) { 6280 tp->rcv_scale = tp->request_r_scale; 6281 } 6282 tp->rcv_adv += min(tp->rcv_wnd, 6283 TCP_MAXWIN << tp->rcv_scale); 6284 /* 6285 * If not all the data that was sent in the TFO SYN 6286 * has been acked, resend the remainder right away. 6287 */ 6288 if (IS_FASTOPEN(tp->t_flags) && 6289 (tp->snd_una != tp->snd_max)) { 6290 tp->snd_nxt = th->th_ack; 6291 tfo_partial = 1; 6292 } 6293 /* 6294 * If there's data, delay ACK; if there's also a FIN ACKNOW 6295 * will be turned on later. 6296 */ 6297 if (DELAY_ACK(tp, tlen) && tlen != 0 && (tfo_partial == 0)) { 6298 rack_timer_cancel(tp, rack, 6299 rack->r_ctl.rc_rcvtime, __LINE__); 6300 tp->t_flags |= TF_DELACK; 6301 } else { 6302 rack->r_wanted_output++; 6303 tp->t_flags |= TF_ACKNOW; 6304 } 6305 6306 if (((thflags & (TH_CWR | TH_ECE)) == TH_ECE) && 6307 (V_tcp_do_ecn == 1)) { 6308 tp->t_flags2 |= TF2_ECN_PERMIT; 6309 KMOD_TCPSTAT_INC(tcps_ecn_shs); 6310 } 6311 if (SEQ_GT(th->th_ack, tp->snd_una)) { 6312 /* 6313 * We advance snd_una for the 6314 * fast open case. If th_ack is 6315 * acknowledging data beyond 6316 * snd_una we can't just call 6317 * ack-processing since the 6318 * data stream in our send-map 6319 * will start at snd_una + 1 (one 6320 * beyond the SYN). If its just 6321 * equal we don't need to do that 6322 * and there is no send_map. 6323 */ 6324 tp->snd_una++; 6325 } 6326 /* 6327 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions: 6328 * SYN_SENT --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1 6329 */ 6330 tp->t_starttime = ticks; 6331 if (tp->t_flags & TF_NEEDFIN) { 6332 tcp_state_change(tp, TCPS_FIN_WAIT_1); 6333 tp->t_flags &= ~TF_NEEDFIN; 6334 thflags &= ~TH_SYN; 6335 } else { 6336 tcp_state_change(tp, TCPS_ESTABLISHED); 6337 TCP_PROBE5(connect__established, NULL, tp, 6338 mtod(m, const char *), tp, th); 6339 cc_conn_init(tp); 6340 } 6341 } else { 6342 /* 6343 * Received initial SYN in SYN-SENT[*] state => simultaneous 6344 * open. If segment contains CC option and there is a 6345 * cached CC, apply TAO test. If it succeeds, connection is * 6346 * half-synchronized. Otherwise, do 3-way handshake: 6347 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If 6348 * there was no CC option, clear cached CC value. 6349 */ 6350 tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN); 6351 tcp_state_change(tp, TCPS_SYN_RECEIVED); 6352 } 6353 INP_WLOCK_ASSERT(tp->t_inpcb); 6354 /* 6355 * Advance th->th_seq to correspond to first data byte. If data, 6356 * trim to stay within window, dropping FIN if necessary. 6357 */ 6358 th->th_seq++; 6359 if (tlen > tp->rcv_wnd) { 6360 todrop = tlen - tp->rcv_wnd; 6361 m_adj(m, -todrop); 6362 tlen = tp->rcv_wnd; 6363 thflags &= ~TH_FIN; 6364 KMOD_TCPSTAT_INC(tcps_rcvpackafterwin); 6365 KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop); 6366 } 6367 tp->snd_wl1 = th->th_seq - 1; 6368 tp->rcv_up = th->th_seq; 6369 /* 6370 * Client side of transaction: already sent SYN and data. If the 6371 * remote host used T/TCP to validate the SYN, our data will be 6372 * ACK'd; if so, enter normal data segment processing in the middle 6373 * of step 5, ack processing. Otherwise, goto step 6. 6374 */ 6375 if (thflags & TH_ACK) { 6376 /* For syn-sent we need to possibly update the rtt */ 6377 if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) { 6378 uint32_t t; 6379 6380 t = tcp_ts_getticks() - to->to_tsecr; 6381 if (!tp->t_rttlow || tp->t_rttlow > t) 6382 tp->t_rttlow = t; 6383 tcp_rack_xmit_timer(rack, t + 1); 6384 tcp_rack_xmit_timer_commit(rack, tp); 6385 } 6386 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) 6387 return (ret_val); 6388 /* We may have changed to FIN_WAIT_1 above */ 6389 if (tp->t_state == TCPS_FIN_WAIT_1) { 6390 /* 6391 * In FIN_WAIT_1 STATE in addition to the processing 6392 * for the ESTABLISHED state if our FIN is now 6393 * acknowledged then enter FIN_WAIT_2. 6394 */ 6395 if (ourfinisacked) { 6396 /* 6397 * If we can't receive any more data, then 6398 * closing user can proceed. Starting the 6399 * timer is contrary to the specification, 6400 * but if we don't get a FIN we'll hang 6401 * forever. 6402 * 6403 * XXXjl: we should release the tp also, and 6404 * use a compressed state. 6405 */ 6406 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 6407 soisdisconnected(so); 6408 tcp_timer_activate(tp, TT_2MSL, 6409 (tcp_fast_finwait2_recycle ? 6410 tcp_finwait2_timeout : 6411 TP_MAXIDLE(tp))); 6412 } 6413 tcp_state_change(tp, TCPS_FIN_WAIT_2); 6414 } 6415 } 6416 } 6417 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6418 tiwin, thflags, nxt_pkt)); 6419 } 6420 6421 /* 6422 * Return value of 1, the TCB is unlocked and most 6423 * likely gone, return value of 0, the TCP is still 6424 * locked. 6425 */ 6426 static int 6427 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so, 6428 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6429 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 6430 { 6431 struct tcp_rack *rack; 6432 int32_t ret_val = 0; 6433 int32_t ourfinisacked = 0; 6434 6435 ctf_calc_rwin(so, tp); 6436 if ((thflags & TH_ACK) && 6437 (SEQ_LEQ(th->th_ack, tp->snd_una) || 6438 SEQ_GT(th->th_ack, tp->snd_max))) { 6439 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6440 return (1); 6441 } 6442 rack = (struct tcp_rack *)tp->t_fb_ptr; 6443 if (IS_FASTOPEN(tp->t_flags)) { 6444 /* 6445 * When a TFO connection is in SYN_RECEIVED, the 6446 * only valid packets are the initial SYN, a 6447 * retransmit/copy of the initial SYN (possibly with 6448 * a subset of the original data), a valid ACK, a 6449 * FIN, or a RST. 6450 */ 6451 if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) { 6452 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6453 return (1); 6454 } else if (thflags & TH_SYN) { 6455 /* non-initial SYN is ignored */ 6456 if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) || 6457 (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) || 6458 (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) { 6459 ctf_do_drop(m, NULL); 6460 return (0); 6461 } 6462 } else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) { 6463 ctf_do_drop(m, NULL); 6464 return (0); 6465 } 6466 } 6467 if ((thflags & TH_RST) || 6468 (tp->t_fin_is_rst && (thflags & TH_FIN))) 6469 return (ctf_process_rst(m, th, so, tp)); 6470 /* 6471 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 6472 * it's less than ts_recent, drop it. 6473 */ 6474 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 6475 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 6476 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 6477 return (ret_val); 6478 } 6479 /* 6480 * In the SYN-RECEIVED state, validate that the packet belongs to 6481 * this connection before trimming the data to fit the receive 6482 * window. Check the sequence number versus IRS since we know the 6483 * sequence numbers haven't wrapped. This is a partial fix for the 6484 * "LAND" DoS attack. 6485 */ 6486 if (SEQ_LT(th->th_seq, tp->irs)) { 6487 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6488 return (1); 6489 } 6490 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 6491 return (ret_val); 6492 } 6493 /* 6494 * If last ACK falls within this segment's sequence numbers, record 6495 * its timestamp. NOTE: 1) That the test incorporates suggestions 6496 * from the latest proposal of the tcplw@cray.com list (Braden 6497 * 1993/04/26). 2) That updating only on newer timestamps interferes 6498 * with our earlier PAWS tests, so this check should be solely 6499 * predicated on the sequence space of this segment. 3) That we 6500 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 6501 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 6502 * SEG.Len, This modified check allows us to overcome RFC1323's 6503 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 6504 * p.869. In such cases, we can still calculate the RTT correctly 6505 * when RCV.NXT == Last.ACK.Sent. 6506 */ 6507 if ((to->to_flags & TOF_TS) != 0 && 6508 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 6509 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 6510 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 6511 tp->ts_recent_age = tcp_ts_getticks(); 6512 tp->ts_recent = to->to_tsval; 6513 } 6514 tp->snd_wnd = tiwin; 6515 /* 6516 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 6517 * is on (half-synchronized state), then queue data for later 6518 * processing; else drop segment and return. 6519 */ 6520 if ((thflags & TH_ACK) == 0) { 6521 if (IS_FASTOPEN(tp->t_flags)) { 6522 cc_conn_init(tp); 6523 } 6524 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6525 tiwin, thflags, nxt_pkt)); 6526 } 6527 KMOD_TCPSTAT_INC(tcps_connects); 6528 soisconnected(so); 6529 /* Do window scaling? */ 6530 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) == 6531 (TF_RCVD_SCALE | TF_REQ_SCALE)) { 6532 tp->rcv_scale = tp->request_r_scale; 6533 } 6534 /* 6535 * Make transitions: SYN-RECEIVED -> ESTABLISHED SYN-RECEIVED* -> 6536 * FIN-WAIT-1 6537 */ 6538 tp->t_starttime = ticks; 6539 if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) { 6540 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 6541 tp->t_tfo_pending = NULL; 6542 6543 /* 6544 * Account for the ACK of our SYN prior to 6545 * regular ACK processing below. 6546 */ 6547 tp->snd_una++; 6548 } 6549 if (tp->t_flags & TF_NEEDFIN) { 6550 tcp_state_change(tp, TCPS_FIN_WAIT_1); 6551 tp->t_flags &= ~TF_NEEDFIN; 6552 } else { 6553 tcp_state_change(tp, TCPS_ESTABLISHED); 6554 TCP_PROBE5(accept__established, NULL, tp, 6555 mtod(m, const char *), tp, th); 6556 /* 6557 * TFO connections call cc_conn_init() during SYN 6558 * processing. Calling it again here for such connections 6559 * is not harmless as it would undo the snd_cwnd reduction 6560 * that occurs when a TFO SYN|ACK is retransmitted. 6561 */ 6562 if (!IS_FASTOPEN(tp->t_flags)) 6563 cc_conn_init(tp); 6564 } 6565 /* 6566 * If segment contains data or ACK, will call tcp_reass() later; if 6567 * not, do so now to pass queued data to user. 6568 */ 6569 if (tlen == 0 && (thflags & TH_FIN) == 0) 6570 (void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0, 6571 (struct mbuf *)0); 6572 tp->snd_wl1 = th->th_seq - 1; 6573 /* For syn-recv we need to possibly update the rtt */ 6574 if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) { 6575 uint32_t t; 6576 6577 t = tcp_ts_getticks() - to->to_tsecr; 6578 if (!tp->t_rttlow || tp->t_rttlow > t) 6579 tp->t_rttlow = t; 6580 tcp_rack_xmit_timer(rack, t + 1); 6581 tcp_rack_xmit_timer_commit(rack, tp); 6582 } 6583 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) { 6584 return (ret_val); 6585 } 6586 if (tp->t_state == TCPS_FIN_WAIT_1) { 6587 /* We could have went to FIN_WAIT_1 (or EST) above */ 6588 /* 6589 * In FIN_WAIT_1 STATE in addition to the processing for the 6590 * ESTABLISHED state if our FIN is now acknowledged then 6591 * enter FIN_WAIT_2. 6592 */ 6593 if (ourfinisacked) { 6594 /* 6595 * If we can't receive any more data, then closing 6596 * user can proceed. Starting the timer is contrary 6597 * to the specification, but if we don't get a FIN 6598 * we'll hang forever. 6599 * 6600 * XXXjl: we should release the tp also, and use a 6601 * compressed state. 6602 */ 6603 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 6604 soisdisconnected(so); 6605 tcp_timer_activate(tp, TT_2MSL, 6606 (tcp_fast_finwait2_recycle ? 6607 tcp_finwait2_timeout : 6608 TP_MAXIDLE(tp))); 6609 } 6610 tcp_state_change(tp, TCPS_FIN_WAIT_2); 6611 } 6612 } 6613 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6614 tiwin, thflags, nxt_pkt)); 6615 } 6616 6617 /* 6618 * Return value of 1, the TCB is unlocked and most 6619 * likely gone, return value of 0, the TCP is still 6620 * locked. 6621 */ 6622 static int 6623 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so, 6624 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6625 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 6626 { 6627 int32_t ret_val = 0; 6628 6629 /* 6630 * Header prediction: check for the two common cases of a 6631 * uni-directional data xfer. If the packet has no control flags, 6632 * is in-sequence, the window didn't change and we're not 6633 * retransmitting, it's a candidate. If the length is zero and the 6634 * ack moved forward, we're the sender side of the xfer. Just free 6635 * the data acked & wake any higher level process that was blocked 6636 * waiting for space. If the length is non-zero and the ack didn't 6637 * move, we're the receiver side. If we're getting packets in-order 6638 * (the reassembly queue is empty), add the data toc The socket 6639 * buffer and note that we need a delayed ack. Make sure that the 6640 * hidden state-flags are also off. Since we check for 6641 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN. 6642 */ 6643 if (__predict_true(((to->to_flags & TOF_SACK) == 0)) && 6644 __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_URG | TH_ACK)) == TH_ACK) && 6645 __predict_true(SEGQ_EMPTY(tp)) && 6646 __predict_true(th->th_seq == tp->rcv_nxt)) { 6647 struct tcp_rack *rack; 6648 6649 rack = (struct tcp_rack *)tp->t_fb_ptr; 6650 if (tlen == 0) { 6651 if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen, 6652 tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime, iptos)) { 6653 return (0); 6654 } 6655 } else { 6656 if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen, 6657 tiwin, nxt_pkt, iptos)) { 6658 return (0); 6659 } 6660 } 6661 } 6662 ctf_calc_rwin(so, tp); 6663 6664 if ((thflags & TH_RST) || 6665 (tp->t_fin_is_rst && (thflags & TH_FIN))) 6666 return (ctf_process_rst(m, th, so, tp)); 6667 6668 /* 6669 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 6670 * synchronized state. 6671 */ 6672 if (thflags & TH_SYN) { 6673 ctf_challenge_ack(m, th, tp, &ret_val); 6674 return (ret_val); 6675 } 6676 /* 6677 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 6678 * it's less than ts_recent, drop it. 6679 */ 6680 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 6681 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 6682 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 6683 return (ret_val); 6684 } 6685 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 6686 return (ret_val); 6687 } 6688 /* 6689 * If last ACK falls within this segment's sequence numbers, record 6690 * its timestamp. NOTE: 1) That the test incorporates suggestions 6691 * from the latest proposal of the tcplw@cray.com list (Braden 6692 * 1993/04/26). 2) That updating only on newer timestamps interferes 6693 * with our earlier PAWS tests, so this check should be solely 6694 * predicated on the sequence space of this segment. 3) That we 6695 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 6696 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 6697 * SEG.Len, This modified check allows us to overcome RFC1323's 6698 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 6699 * p.869. In such cases, we can still calculate the RTT correctly 6700 * when RCV.NXT == Last.ACK.Sent. 6701 */ 6702 if ((to->to_flags & TOF_TS) != 0 && 6703 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 6704 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 6705 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 6706 tp->ts_recent_age = tcp_ts_getticks(); 6707 tp->ts_recent = to->to_tsval; 6708 } 6709 /* 6710 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 6711 * is on (half-synchronized state), then queue data for later 6712 * processing; else drop segment and return. 6713 */ 6714 if ((thflags & TH_ACK) == 0) { 6715 if (tp->t_flags & TF_NEEDSYN) { 6716 6717 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6718 tiwin, thflags, nxt_pkt)); 6719 6720 } else if (tp->t_flags & TF_ACKNOW) { 6721 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 6722 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 6723 return (ret_val); 6724 } else { 6725 ctf_do_drop(m, NULL); 6726 return (0); 6727 } 6728 } 6729 /* 6730 * Ack processing. 6731 */ 6732 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) { 6733 return (ret_val); 6734 } 6735 if (sbavail(&so->so_snd)) { 6736 if (rack_progress_timeout_check(tp)) { 6737 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 6738 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6739 return (1); 6740 } 6741 } 6742 /* State changes only happen in rack_process_data() */ 6743 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6744 tiwin, thflags, nxt_pkt)); 6745 } 6746 6747 /* 6748 * Return value of 1, the TCB is unlocked and most 6749 * likely gone, return value of 0, the TCP is still 6750 * locked. 6751 */ 6752 static int 6753 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so, 6754 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6755 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 6756 { 6757 int32_t ret_val = 0; 6758 6759 ctf_calc_rwin(so, tp); 6760 if ((thflags & TH_RST) || 6761 (tp->t_fin_is_rst && (thflags & TH_FIN))) 6762 return (ctf_process_rst(m, th, so, tp)); 6763 /* 6764 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 6765 * synchronized state. 6766 */ 6767 if (thflags & TH_SYN) { 6768 ctf_challenge_ack(m, th, tp, &ret_val); 6769 return (ret_val); 6770 } 6771 /* 6772 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 6773 * it's less than ts_recent, drop it. 6774 */ 6775 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 6776 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 6777 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 6778 return (ret_val); 6779 } 6780 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 6781 return (ret_val); 6782 } 6783 /* 6784 * If last ACK falls within this segment's sequence numbers, record 6785 * its timestamp. NOTE: 1) That the test incorporates suggestions 6786 * from the latest proposal of the tcplw@cray.com list (Braden 6787 * 1993/04/26). 2) That updating only on newer timestamps interferes 6788 * with our earlier PAWS tests, so this check should be solely 6789 * predicated on the sequence space of this segment. 3) That we 6790 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 6791 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 6792 * SEG.Len, This modified check allows us to overcome RFC1323's 6793 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 6794 * p.869. In such cases, we can still calculate the RTT correctly 6795 * when RCV.NXT == Last.ACK.Sent. 6796 */ 6797 if ((to->to_flags & TOF_TS) != 0 && 6798 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 6799 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 6800 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 6801 tp->ts_recent_age = tcp_ts_getticks(); 6802 tp->ts_recent = to->to_tsval; 6803 } 6804 /* 6805 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 6806 * is on (half-synchronized state), then queue data for later 6807 * processing; else drop segment and return. 6808 */ 6809 if ((thflags & TH_ACK) == 0) { 6810 if (tp->t_flags & TF_NEEDSYN) { 6811 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6812 tiwin, thflags, nxt_pkt)); 6813 6814 } else if (tp->t_flags & TF_ACKNOW) { 6815 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 6816 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 6817 return (ret_val); 6818 } else { 6819 ctf_do_drop(m, NULL); 6820 return (0); 6821 } 6822 } 6823 /* 6824 * Ack processing. 6825 */ 6826 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) { 6827 return (ret_val); 6828 } 6829 if (sbavail(&so->so_snd)) { 6830 if (rack_progress_timeout_check(tp)) { 6831 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 6832 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6833 return (1); 6834 } 6835 } 6836 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6837 tiwin, thflags, nxt_pkt)); 6838 } 6839 6840 static int 6841 rack_check_data_after_close(struct mbuf *m, 6842 struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so) 6843 { 6844 struct tcp_rack *rack; 6845 6846 rack = (struct tcp_rack *)tp->t_fb_ptr; 6847 if (rack->rc_allow_data_af_clo == 0) { 6848 close_now: 6849 tp = tcp_close(tp); 6850 KMOD_TCPSTAT_INC(tcps_rcvafterclose); 6851 ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen)); 6852 return (1); 6853 } 6854 if (sbavail(&so->so_snd) == 0) 6855 goto close_now; 6856 /* Ok we allow data that is ignored and a followup reset */ 6857 tp->rcv_nxt = th->th_seq + *tlen; 6858 tp->t_flags2 |= TF2_DROP_AF_DATA; 6859 rack->r_wanted_output = 1; 6860 *tlen = 0; 6861 return (0); 6862 } 6863 6864 /* 6865 * Return value of 1, the TCB is unlocked and most 6866 * likely gone, return value of 0, the TCP is still 6867 * locked. 6868 */ 6869 static int 6870 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so, 6871 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6872 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 6873 { 6874 int32_t ret_val = 0; 6875 int32_t ourfinisacked = 0; 6876 6877 ctf_calc_rwin(so, tp); 6878 6879 if ((thflags & TH_RST) || 6880 (tp->t_fin_is_rst && (thflags & TH_FIN))) 6881 return (ctf_process_rst(m, th, so, tp)); 6882 /* 6883 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 6884 * synchronized state. 6885 */ 6886 if (thflags & TH_SYN) { 6887 ctf_challenge_ack(m, th, tp, &ret_val); 6888 return (ret_val); 6889 } 6890 /* 6891 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 6892 * it's less than ts_recent, drop it. 6893 */ 6894 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 6895 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 6896 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 6897 return (ret_val); 6898 } 6899 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 6900 return (ret_val); 6901 } 6902 /* 6903 * If new data are received on a connection after the user processes 6904 * are gone, then RST the other end. 6905 */ 6906 if ((so->so_state & SS_NOFDREF) && tlen) { 6907 if (rack_check_data_after_close(m, tp, &tlen, th, so)) 6908 return (1); 6909 } 6910 /* 6911 * If last ACK falls within this segment's sequence numbers, record 6912 * its timestamp. NOTE: 1) That the test incorporates suggestions 6913 * from the latest proposal of the tcplw@cray.com list (Braden 6914 * 1993/04/26). 2) That updating only on newer timestamps interferes 6915 * with our earlier PAWS tests, so this check should be solely 6916 * predicated on the sequence space of this segment. 3) That we 6917 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 6918 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 6919 * SEG.Len, This modified check allows us to overcome RFC1323's 6920 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 6921 * p.869. In such cases, we can still calculate the RTT correctly 6922 * when RCV.NXT == Last.ACK.Sent. 6923 */ 6924 if ((to->to_flags & TOF_TS) != 0 && 6925 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 6926 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 6927 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 6928 tp->ts_recent_age = tcp_ts_getticks(); 6929 tp->ts_recent = to->to_tsval; 6930 } 6931 /* 6932 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 6933 * is on (half-synchronized state), then queue data for later 6934 * processing; else drop segment and return. 6935 */ 6936 if ((thflags & TH_ACK) == 0) { 6937 if (tp->t_flags & TF_NEEDSYN) { 6938 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6939 tiwin, thflags, nxt_pkt)); 6940 } else if (tp->t_flags & TF_ACKNOW) { 6941 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 6942 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 6943 return (ret_val); 6944 } else { 6945 ctf_do_drop(m, NULL); 6946 return (0); 6947 } 6948 } 6949 /* 6950 * Ack processing. 6951 */ 6952 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) { 6953 return (ret_val); 6954 } 6955 if (ourfinisacked) { 6956 /* 6957 * If we can't receive any more data, then closing user can 6958 * proceed. Starting the timer is contrary to the 6959 * specification, but if we don't get a FIN we'll hang 6960 * forever. 6961 * 6962 * XXXjl: we should release the tp also, and use a 6963 * compressed state. 6964 */ 6965 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 6966 soisdisconnected(so); 6967 tcp_timer_activate(tp, TT_2MSL, 6968 (tcp_fast_finwait2_recycle ? 6969 tcp_finwait2_timeout : 6970 TP_MAXIDLE(tp))); 6971 } 6972 tcp_state_change(tp, TCPS_FIN_WAIT_2); 6973 } 6974 if (sbavail(&so->so_snd)) { 6975 if (rack_progress_timeout_check(tp)) { 6976 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 6977 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 6978 return (1); 6979 } 6980 } 6981 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 6982 tiwin, thflags, nxt_pkt)); 6983 } 6984 6985 /* 6986 * Return value of 1, the TCB is unlocked and most 6987 * likely gone, return value of 0, the TCP is still 6988 * locked. 6989 */ 6990 static int 6991 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so, 6992 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 6993 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 6994 { 6995 int32_t ret_val = 0; 6996 int32_t ourfinisacked = 0; 6997 6998 ctf_calc_rwin(so, tp); 6999 7000 if ((thflags & TH_RST) || 7001 (tp->t_fin_is_rst && (thflags & TH_FIN))) 7002 return (ctf_process_rst(m, th, so, tp)); 7003 /* 7004 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 7005 * synchronized state. 7006 */ 7007 if (thflags & TH_SYN) { 7008 ctf_challenge_ack(m, th, tp, &ret_val); 7009 return (ret_val); 7010 } 7011 /* 7012 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 7013 * it's less than ts_recent, drop it. 7014 */ 7015 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 7016 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 7017 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 7018 return (ret_val); 7019 } 7020 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 7021 return (ret_val); 7022 } 7023 /* 7024 * If new data are received on a connection after the user processes 7025 * are gone, then RST the other end. 7026 */ 7027 if ((so->so_state & SS_NOFDREF) && tlen) { 7028 if (rack_check_data_after_close(m, tp, &tlen, th, so)) 7029 return (1); 7030 } 7031 /* 7032 * If last ACK falls within this segment's sequence numbers, record 7033 * its timestamp. NOTE: 1) That the test incorporates suggestions 7034 * from the latest proposal of the tcplw@cray.com list (Braden 7035 * 1993/04/26). 2) That updating only on newer timestamps interferes 7036 * with our earlier PAWS tests, so this check should be solely 7037 * predicated on the sequence space of this segment. 3) That we 7038 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 7039 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 7040 * SEG.Len, This modified check allows us to overcome RFC1323's 7041 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 7042 * p.869. In such cases, we can still calculate the RTT correctly 7043 * when RCV.NXT == Last.ACK.Sent. 7044 */ 7045 if ((to->to_flags & TOF_TS) != 0 && 7046 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 7047 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 7048 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 7049 tp->ts_recent_age = tcp_ts_getticks(); 7050 tp->ts_recent = to->to_tsval; 7051 } 7052 /* 7053 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 7054 * is on (half-synchronized state), then queue data for later 7055 * processing; else drop segment and return. 7056 */ 7057 if ((thflags & TH_ACK) == 0) { 7058 if (tp->t_flags & TF_NEEDSYN) { 7059 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7060 tiwin, thflags, nxt_pkt)); 7061 } else if (tp->t_flags & TF_ACKNOW) { 7062 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 7063 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 7064 return (ret_val); 7065 } else { 7066 ctf_do_drop(m, NULL); 7067 return (0); 7068 } 7069 } 7070 /* 7071 * Ack processing. 7072 */ 7073 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) { 7074 return (ret_val); 7075 } 7076 if (ourfinisacked) { 7077 tcp_twstart(tp); 7078 m_freem(m); 7079 return (1); 7080 } 7081 if (sbavail(&so->so_snd)) { 7082 if (rack_progress_timeout_check(tp)) { 7083 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 7084 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 7085 return (1); 7086 } 7087 } 7088 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7089 tiwin, thflags, nxt_pkt)); 7090 } 7091 7092 /* 7093 * Return value of 1, the TCB is unlocked and most 7094 * likely gone, return value of 0, the TCP is still 7095 * locked. 7096 */ 7097 static int 7098 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so, 7099 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 7100 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 7101 { 7102 int32_t ret_val = 0; 7103 int32_t ourfinisacked = 0; 7104 7105 ctf_calc_rwin(so, tp); 7106 7107 if ((thflags & TH_RST) || 7108 (tp->t_fin_is_rst && (thflags & TH_FIN))) 7109 return (ctf_process_rst(m, th, so, tp)); 7110 /* 7111 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 7112 * synchronized state. 7113 */ 7114 if (thflags & TH_SYN) { 7115 ctf_challenge_ack(m, th, tp, &ret_val); 7116 return (ret_val); 7117 } 7118 /* 7119 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 7120 * it's less than ts_recent, drop it. 7121 */ 7122 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 7123 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 7124 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 7125 return (ret_val); 7126 } 7127 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 7128 return (ret_val); 7129 } 7130 /* 7131 * If new data are received on a connection after the user processes 7132 * are gone, then RST the other end. 7133 */ 7134 if ((so->so_state & SS_NOFDREF) && tlen) { 7135 if (rack_check_data_after_close(m, tp, &tlen, th, so)) 7136 return (1); 7137 } 7138 /* 7139 * If last ACK falls within this segment's sequence numbers, record 7140 * its timestamp. NOTE: 1) That the test incorporates suggestions 7141 * from the latest proposal of the tcplw@cray.com list (Braden 7142 * 1993/04/26). 2) That updating only on newer timestamps interferes 7143 * with our earlier PAWS tests, so this check should be solely 7144 * predicated on the sequence space of this segment. 3) That we 7145 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 7146 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 7147 * SEG.Len, This modified check allows us to overcome RFC1323's 7148 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 7149 * p.869. In such cases, we can still calculate the RTT correctly 7150 * when RCV.NXT == Last.ACK.Sent. 7151 */ 7152 if ((to->to_flags & TOF_TS) != 0 && 7153 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 7154 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 7155 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 7156 tp->ts_recent_age = tcp_ts_getticks(); 7157 tp->ts_recent = to->to_tsval; 7158 } 7159 /* 7160 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 7161 * is on (half-synchronized state), then queue data for later 7162 * processing; else drop segment and return. 7163 */ 7164 if ((thflags & TH_ACK) == 0) { 7165 if (tp->t_flags & TF_NEEDSYN) { 7166 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7167 tiwin, thflags, nxt_pkt)); 7168 } else if (tp->t_flags & TF_ACKNOW) { 7169 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 7170 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 7171 return (ret_val); 7172 } else { 7173 ctf_do_drop(m, NULL); 7174 return (0); 7175 } 7176 } 7177 /* 7178 * case TCPS_LAST_ACK: Ack processing. 7179 */ 7180 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) { 7181 return (ret_val); 7182 } 7183 if (ourfinisacked) { 7184 tp = tcp_close(tp); 7185 ctf_do_drop(m, tp); 7186 return (1); 7187 } 7188 if (sbavail(&so->so_snd)) { 7189 if (rack_progress_timeout_check(tp)) { 7190 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 7191 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 7192 return (1); 7193 } 7194 } 7195 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7196 tiwin, thflags, nxt_pkt)); 7197 } 7198 7199 7200 /* 7201 * Return value of 1, the TCB is unlocked and most 7202 * likely gone, return value of 0, the TCP is still 7203 * locked. 7204 */ 7205 static int 7206 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so, 7207 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen, 7208 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos) 7209 { 7210 int32_t ret_val = 0; 7211 int32_t ourfinisacked = 0; 7212 7213 ctf_calc_rwin(so, tp); 7214 7215 /* Reset receive buffer auto scaling when not in bulk receive mode. */ 7216 if ((thflags & TH_RST) || 7217 (tp->t_fin_is_rst && (thflags & TH_FIN))) 7218 return (ctf_process_rst(m, th, so, tp)); 7219 /* 7220 * RFC5961 Section 4.2 Send challenge ACK for any SYN in 7221 * synchronized state. 7222 */ 7223 if (thflags & TH_SYN) { 7224 ctf_challenge_ack(m, th, tp, &ret_val); 7225 return (ret_val); 7226 } 7227 /* 7228 * RFC 1323 PAWS: If we have a timestamp reply on this segment and 7229 * it's less than ts_recent, drop it. 7230 */ 7231 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && 7232 TSTMP_LT(to->to_tsval, tp->ts_recent)) { 7233 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val)) 7234 return (ret_val); 7235 } 7236 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) { 7237 return (ret_val); 7238 } 7239 /* 7240 * If new data are received on a connection after the user processes 7241 * are gone, then RST the other end. 7242 */ 7243 if ((so->so_state & SS_NOFDREF) && 7244 tlen) { 7245 if (rack_check_data_after_close(m, tp, &tlen, th, so)) 7246 return (1); 7247 } 7248 /* 7249 * If last ACK falls within this segment's sequence numbers, record 7250 * its timestamp. NOTE: 1) That the test incorporates suggestions 7251 * from the latest proposal of the tcplw@cray.com list (Braden 7252 * 1993/04/26). 2) That updating only on newer timestamps interferes 7253 * with our earlier PAWS tests, so this check should be solely 7254 * predicated on the sequence space of this segment. 3) That we 7255 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ 7256 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ + 7257 * SEG.Len, This modified check allows us to overcome RFC1323's 7258 * limitations as described in Stevens TCP/IP Illustrated Vol. 2 7259 * p.869. In such cases, we can still calculate the RTT correctly 7260 * when RCV.NXT == Last.ACK.Sent. 7261 */ 7262 if ((to->to_flags & TOF_TS) != 0 && 7263 SEQ_LEQ(th->th_seq, tp->last_ack_sent) && 7264 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + 7265 ((thflags & (TH_SYN | TH_FIN)) != 0))) { 7266 tp->ts_recent_age = tcp_ts_getticks(); 7267 tp->ts_recent = to->to_tsval; 7268 } 7269 /* 7270 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag 7271 * is on (half-synchronized state), then queue data for later 7272 * processing; else drop segment and return. 7273 */ 7274 if ((thflags & TH_ACK) == 0) { 7275 if (tp->t_flags & TF_NEEDSYN) { 7276 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7277 tiwin, thflags, nxt_pkt)); 7278 } else if (tp->t_flags & TF_ACKNOW) { 7279 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val); 7280 ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++; 7281 return (ret_val); 7282 } else { 7283 ctf_do_drop(m, NULL); 7284 return (0); 7285 } 7286 } 7287 /* 7288 * Ack processing. 7289 */ 7290 if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) { 7291 return (ret_val); 7292 } 7293 if (sbavail(&so->so_snd)) { 7294 if (rack_progress_timeout_check(tp)) { 7295 tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT); 7296 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 7297 return (1); 7298 } 7299 } 7300 return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen, 7301 tiwin, thflags, nxt_pkt)); 7302 } 7303 7304 7305 static void inline 7306 rack_clear_rate_sample(struct tcp_rack *rack) 7307 { 7308 rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY; 7309 rack->r_ctl.rack_rs.rs_rtt_cnt = 0; 7310 rack->r_ctl.rack_rs.rs_rtt_tot = 0; 7311 } 7312 7313 static void 7314 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack) 7315 { 7316 uint32_t tls_seg = 0; 7317 7318 #ifdef KERN_TLS 7319 if (rack->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) { 7320 tls_seg = ctf_get_opt_tls_size(rack->rc_inp->inp_socket, rack->rc_tp->snd_wnd); 7321 rack->r_ctl.rc_pace_min_segs = tls_seg; 7322 } else 7323 #endif 7324 rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp); 7325 rack->r_ctl.rc_pace_max_segs = ctf_fixed_maxseg(tp) * rack->rc_pace_max_segs; 7326 if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) 7327 rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES; 7328 #ifdef KERN_TLS 7329 if (tls_seg != 0) { 7330 if (rack_hw_tls_max_seg > 1) { 7331 rack->r_ctl.rc_pace_max_segs /= tls_seg; 7332 if (rack_hw_tls_max_seg < rack->r_ctl.rc_pace_max_segs) 7333 rack->r_ctl.rc_pace_max_segs = rack_hw_tls_max_seg; 7334 } else { 7335 rack->r_ctl.rc_pace_max_segs = 1; 7336 } 7337 if (rack->r_ctl.rc_pace_max_segs == 0) 7338 rack->r_ctl.rc_pace_max_segs = 1; 7339 rack->r_ctl.rc_pace_max_segs *= tls_seg; 7340 } 7341 #endif 7342 rack_log_type_hrdwtso(tp, rack, tls_seg, rack->rc_inp->inp_socket->so_snd.sb_flags, 0, 2); 7343 } 7344 7345 static int 7346 rack_init(struct tcpcb *tp) 7347 { 7348 struct tcp_rack *rack = NULL; 7349 struct rack_sendmap *insret; 7350 7351 tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT); 7352 if (tp->t_fb_ptr == NULL) { 7353 /* 7354 * We need to allocate memory but cant. The INP and INP_INFO 7355 * locks and they are recusive (happens during setup. So a 7356 * scheme to drop the locks fails :( 7357 * 7358 */ 7359 return (ENOMEM); 7360 } 7361 memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack)); 7362 7363 rack = (struct tcp_rack *)tp->t_fb_ptr; 7364 RB_INIT(&rack->r_ctl.rc_mtree); 7365 TAILQ_INIT(&rack->r_ctl.rc_free); 7366 TAILQ_INIT(&rack->r_ctl.rc_tmap); 7367 rack->rc_tp = tp; 7368 if (tp->t_inpcb) { 7369 rack->rc_inp = tp->t_inpcb; 7370 } 7371 tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ; 7372 /* Probably not needed but lets be sure */ 7373 rack_clear_rate_sample(rack); 7374 rack->r_cpu = 0; 7375 rack->r_ctl.rc_reorder_fade = rack_reorder_fade; 7376 rack->rc_allow_data_af_clo = rack_ignore_data_after_close; 7377 rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh; 7378 rack->rc_pace_reduce = rack_slot_reduction; 7379 if (use_rack_cheat) 7380 rack->use_rack_cheat = 1; 7381 if (V_tcp_delack_enabled) 7382 tp->t_delayed_ack = 1; 7383 else 7384 tp->t_delayed_ack = 0; 7385 rack->rc_pace_max_segs = rack_hptsi_segments; 7386 rack->r_ctl.rc_reorder_shift = rack_reorder_thresh; 7387 rack->r_ctl.rc_pkt_delay = rack_pkt_delay; 7388 rack->r_ctl.rc_prop_reduce = rack_use_proportional_reduce; 7389 rack->r_enforce_min_pace = rack_min_pace_time; 7390 rack->r_ctl.rc_prop_rate = rack_proportional_rate; 7391 rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp; 7392 rack->r_ctl.rc_early_recovery = rack_early_recovery; 7393 rack->rc_always_pace = rack_pace_every_seg; 7394 rack_set_pace_segments(tp, rack); 7395 rack->r_ctl.rc_high_rwnd = tp->snd_wnd; 7396 rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method; 7397 rack->rack_tlp_threshold_use = rack_tlp_threshold_use; 7398 rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr; 7399 rack->r_ctl.rc_min_to = rack_min_to; 7400 rack->rack_per_of_gp = rack_per_of_gp; 7401 microuptime(&rack->r_ctl.rc_last_ack); 7402 rack->r_ctl.rc_last_time_decay = rack->r_ctl.rc_last_ack; 7403 rack->r_ctl.rc_tlp_rxt_last_time = tcp_ts_getticks(); 7404 /* Do we force on detection? */ 7405 #ifdef NETFLIX_EXP_DETECTION 7406 if (tcp_force_detection) 7407 rack->do_detection = 1; 7408 else 7409 #endif 7410 rack->do_detection = 0; 7411 if (tp->snd_una != tp->snd_max) { 7412 /* Create a send map for the current outstanding data */ 7413 struct rack_sendmap *rsm; 7414 7415 rsm = rack_alloc(rack); 7416 if (rsm == NULL) { 7417 uma_zfree(rack_pcb_zone, tp->t_fb_ptr); 7418 tp->t_fb_ptr = NULL; 7419 return (ENOMEM); 7420 } 7421 rsm->r_flags = RACK_OVERMAX; 7422 rsm->r_tim_lastsent[0] = rack->r_ctl.rc_tlp_rxt_last_time; 7423 rsm->r_rtr_cnt = 1; 7424 rsm->r_rtr_bytes = 0; 7425 rsm->r_start = tp->snd_una; 7426 rsm->r_end = tp->snd_max; 7427 rsm->r_dupack = 0; 7428 insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 7429 #ifdef INVARIANTS 7430 if (insret != NULL) { 7431 panic("Insert in rb tree fails ret:%p rack:%p rsm:%p", 7432 insret, rack, rsm); 7433 } 7434 #endif 7435 TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext); 7436 rsm->r_in_tmap = 1; 7437 } 7438 rack_stop_all_timers(tp); 7439 rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0); 7440 return (0); 7441 } 7442 7443 static int 7444 rack_handoff_ok(struct tcpcb *tp) 7445 { 7446 if ((tp->t_state == TCPS_CLOSED) || 7447 (tp->t_state == TCPS_LISTEN)) { 7448 /* Sure no problem though it may not stick */ 7449 return (0); 7450 } 7451 if ((tp->t_state == TCPS_SYN_SENT) || 7452 (tp->t_state == TCPS_SYN_RECEIVED)) { 7453 /* 7454 * We really don't know you have to get to ESTAB or beyond 7455 * to tell. 7456 */ 7457 return (EAGAIN); 7458 } 7459 if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){ 7460 return (0); 7461 } 7462 /* 7463 * If we reach here we don't do SACK on this connection so we can 7464 * never do rack. 7465 */ 7466 return (EINVAL); 7467 } 7468 7469 static void 7470 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged) 7471 { 7472 if (tp->t_fb_ptr) { 7473 struct tcp_rack *rack; 7474 struct rack_sendmap *rsm, *nrsm, *rm; 7475 if (tp->t_inpcb) { 7476 tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ; 7477 tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY; 7478 } 7479 rack = (struct tcp_rack *)tp->t_fb_ptr; 7480 #ifdef TCP_BLACKBOX 7481 tcp_log_flowend(tp); 7482 #endif 7483 RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) { 7484 rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm); 7485 #ifdef INVARIANTS 7486 if (rm != rsm) { 7487 panic("At fini, rack:%p rsm:%p rm:%p", 7488 rack, rsm, rm); 7489 } 7490 #endif 7491 uma_zfree(rack_zone, rsm); 7492 } 7493 rsm = TAILQ_FIRST(&rack->r_ctl.rc_free); 7494 while (rsm) { 7495 TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext); 7496 uma_zfree(rack_zone, rsm); 7497 rsm = TAILQ_FIRST(&rack->r_ctl.rc_free); 7498 } 7499 rack->rc_free_cnt = 0; 7500 uma_zfree(rack_pcb_zone, tp->t_fb_ptr); 7501 tp->t_fb_ptr = NULL; 7502 } 7503 /* Make sure snd_nxt is correctly set */ 7504 tp->snd_nxt = tp->snd_max; 7505 } 7506 7507 7508 static void 7509 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack) 7510 { 7511 switch (tp->t_state) { 7512 case TCPS_SYN_SENT: 7513 rack->r_state = TCPS_SYN_SENT; 7514 rack->r_substate = rack_do_syn_sent; 7515 break; 7516 case TCPS_SYN_RECEIVED: 7517 rack->r_state = TCPS_SYN_RECEIVED; 7518 rack->r_substate = rack_do_syn_recv; 7519 break; 7520 case TCPS_ESTABLISHED: 7521 rack_set_pace_segments(tp, rack); 7522 rack->r_state = TCPS_ESTABLISHED; 7523 rack->r_substate = rack_do_established; 7524 break; 7525 case TCPS_CLOSE_WAIT: 7526 rack->r_state = TCPS_CLOSE_WAIT; 7527 rack->r_substate = rack_do_close_wait; 7528 break; 7529 case TCPS_FIN_WAIT_1: 7530 rack->r_state = TCPS_FIN_WAIT_1; 7531 rack->r_substate = rack_do_fin_wait_1; 7532 break; 7533 case TCPS_CLOSING: 7534 rack->r_state = TCPS_CLOSING; 7535 rack->r_substate = rack_do_closing; 7536 break; 7537 case TCPS_LAST_ACK: 7538 rack->r_state = TCPS_LAST_ACK; 7539 rack->r_substate = rack_do_lastack; 7540 break; 7541 case TCPS_FIN_WAIT_2: 7542 rack->r_state = TCPS_FIN_WAIT_2; 7543 rack->r_substate = rack_do_fin_wait_2; 7544 break; 7545 case TCPS_LISTEN: 7546 case TCPS_CLOSED: 7547 case TCPS_TIME_WAIT: 7548 default: 7549 break; 7550 }; 7551 } 7552 7553 7554 static void 7555 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb) 7556 { 7557 /* 7558 * We received an ack, and then did not 7559 * call send or were bounced out due to the 7560 * hpts was running. Now a timer is up as well, is 7561 * it the right timer? 7562 */ 7563 struct rack_sendmap *rsm; 7564 int tmr_up; 7565 7566 tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK; 7567 if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT)) 7568 return; 7569 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 7570 if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) && 7571 (tmr_up == PACE_TMR_RXT)) { 7572 /* Should be an RXT */ 7573 return; 7574 } 7575 if (rsm == NULL) { 7576 /* Nothing outstanding? */ 7577 if (tp->t_flags & TF_DELACK) { 7578 if (tmr_up == PACE_TMR_DELACK) 7579 /* We are supposed to have delayed ack up and we do */ 7580 return; 7581 } else if (sbavail(&tp->t_inpcb->inp_socket->so_snd) && (tmr_up == PACE_TMR_RXT)) { 7582 /* 7583 * if we hit enobufs then we would expect the possiblity 7584 * of nothing outstanding and the RXT up (and the hptsi timer). 7585 */ 7586 return; 7587 } else if (((V_tcp_always_keepalive || 7588 rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) && 7589 (tp->t_state <= TCPS_CLOSING)) && 7590 (tmr_up == PACE_TMR_KEEP) && 7591 (tp->snd_max == tp->snd_una)) { 7592 /* We should have keep alive up and we do */ 7593 return; 7594 } 7595 } 7596 if (SEQ_GT(tp->snd_max, tp->snd_una) && 7597 ((tmr_up == PACE_TMR_TLP) || 7598 (tmr_up == PACE_TMR_RACK) || 7599 (tmr_up == PACE_TMR_RXT))) { 7600 /* 7601 * Either a Rack, TLP or RXT is fine if we 7602 * have outstanding data. 7603 */ 7604 return; 7605 } else if (tmr_up == PACE_TMR_DELACK) { 7606 /* 7607 * If the delayed ack was going to go off 7608 * before the rtx/tlp/rack timer were going to 7609 * expire, then that would be the timer in control. 7610 * Note we don't check the time here trusting the 7611 * code is correct. 7612 */ 7613 return; 7614 } 7615 /* 7616 * Ok the timer originally started is not what we want now. 7617 * We will force the hpts to be stopped if any, and restart 7618 * with the slot set to what was in the saved slot. 7619 */ 7620 rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__); 7621 rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0); 7622 } 7623 7624 static int 7625 rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so, 7626 struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos, 7627 int32_t nxt_pkt, struct timeval *tv) 7628 { 7629 int32_t thflags, retval, did_out = 0; 7630 int32_t way_out = 0; 7631 uint32_t cts; 7632 uint32_t tiwin; 7633 struct tcpopt to; 7634 struct tcp_rack *rack; 7635 struct rack_sendmap *rsm; 7636 int32_t prev_state = 0; 7637 7638 if (m->m_flags & M_TSTMP_LRO) { 7639 tv->tv_sec = m->m_pkthdr.rcv_tstmp /1000000000; 7640 tv->tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000; 7641 } 7642 cts = tcp_tv_to_mssectick(tv); 7643 rack = (struct tcp_rack *)tp->t_fb_ptr; 7644 7645 kern_prefetch(rack, &prev_state); 7646 prev_state = 0; 7647 thflags = th->th_flags; 7648 7649 NET_EPOCH_ASSERT(); 7650 INP_WLOCK_ASSERT(tp->t_inpcb); 7651 KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN", 7652 __func__)); 7653 KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT", 7654 __func__)); 7655 if (tp->t_logstate != TCP_LOG_STATE_OFF) { 7656 union tcp_log_stackspecific log; 7657 struct timeval tv; 7658 7659 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 7660 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 7661 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 7662 log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt; 7663 log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced; 7664 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 7665 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 7666 log.u_bbr.pkts_out = rack->rc_tp->t_maxseg; 7667 TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0, 7668 tlen, &log, true, &tv); 7669 } 7670 if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) { 7671 way_out = 4; 7672 retval = 0; 7673 goto done_with_input; 7674 } 7675 /* 7676 * If a segment with the ACK-bit set arrives in the SYN-SENT state 7677 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9. 7678 */ 7679 if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) && 7680 (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) { 7681 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen); 7682 return(1); 7683 } 7684 /* 7685 * Segment received on connection. Reset idle time and keep-alive 7686 * timer. XXX: This should be done after segment validation to 7687 * ignore broken/spoofed segs. 7688 */ 7689 if (tp->t_idle_reduce && 7690 (tp->snd_max == tp->snd_una) && 7691 ((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) { 7692 counter_u64_add(rack_input_idle_reduces, 1); 7693 rack_cc_after_idle(tp); 7694 } 7695 tp->t_rcvtime = ticks; 7696 7697 /* 7698 * Unscale the window into a 32-bit value. For the SYN_SENT state 7699 * the scale is zero. 7700 */ 7701 tiwin = th->th_win << tp->snd_scale; 7702 #ifdef STATS 7703 stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin); 7704 #endif 7705 if (tiwin > rack->r_ctl.rc_high_rwnd) 7706 rack->r_ctl.rc_high_rwnd = tiwin; 7707 /* 7708 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move 7709 * this to occur after we've validated the segment. 7710 */ 7711 if (tp->t_flags2 & TF2_ECN_PERMIT) { 7712 if (thflags & TH_CWR) { 7713 tp->t_flags2 &= ~TF2_ECN_SND_ECE; 7714 tp->t_flags |= TF_ACKNOW; 7715 } 7716 switch (iptos & IPTOS_ECN_MASK) { 7717 case IPTOS_ECN_CE: 7718 tp->t_flags2 |= TF2_ECN_SND_ECE; 7719 KMOD_TCPSTAT_INC(tcps_ecn_ce); 7720 break; 7721 case IPTOS_ECN_ECT0: 7722 KMOD_TCPSTAT_INC(tcps_ecn_ect0); 7723 break; 7724 case IPTOS_ECN_ECT1: 7725 KMOD_TCPSTAT_INC(tcps_ecn_ect1); 7726 break; 7727 } 7728 7729 /* Process a packet differently from RFC3168. */ 7730 cc_ecnpkt_handler(tp, th, iptos); 7731 7732 /* Congestion experienced. */ 7733 if (thflags & TH_ECE) { 7734 rack_cong_signal(tp, th, CC_ECN); 7735 } 7736 } 7737 /* 7738 * Parse options on any incoming segment. 7739 */ 7740 tcp_dooptions(&to, (u_char *)(th + 1), 7741 (th->th_off << 2) - sizeof(struct tcphdr), 7742 (thflags & TH_SYN) ? TO_SYN : 0); 7743 7744 /* 7745 * If echoed timestamp is later than the current time, fall back to 7746 * non RFC1323 RTT calculation. Normalize timestamp if syncookies 7747 * were used when this connection was established. 7748 */ 7749 if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) { 7750 to.to_tsecr -= tp->ts_offset; 7751 if (TSTMP_GT(to.to_tsecr, cts)) 7752 to.to_tsecr = 0; 7753 } 7754 /* 7755 * If its the first time in we need to take care of options and 7756 * verify we can do SACK for rack! 7757 */ 7758 if (rack->r_state == 0) { 7759 /* Should be init'd by rack_init() */ 7760 KASSERT(rack->rc_inp != NULL, 7761 ("%s: rack->rc_inp unexpectedly NULL", __func__)); 7762 if (rack->rc_inp == NULL) { 7763 rack->rc_inp = tp->t_inpcb; 7764 } 7765 7766 /* 7767 * Process options only when we get SYN/ACK back. The SYN 7768 * case for incoming connections is handled in tcp_syncache. 7769 * According to RFC1323 the window field in a SYN (i.e., a 7770 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX 7771 * this is traditional behavior, may need to be cleaned up. 7772 */ 7773 rack->r_cpu = inp_to_cpuid(tp->t_inpcb); 7774 if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) { 7775 if ((to.to_flags & TOF_SCALE) && 7776 (tp->t_flags & TF_REQ_SCALE)) { 7777 tp->t_flags |= TF_RCVD_SCALE; 7778 tp->snd_scale = to.to_wscale; 7779 } 7780 /* 7781 * Initial send window. It will be updated with the 7782 * next incoming segment to the scaled value. 7783 */ 7784 tp->snd_wnd = th->th_win; 7785 if (to.to_flags & TOF_TS) { 7786 tp->t_flags |= TF_RCVD_TSTMP; 7787 tp->ts_recent = to.to_tsval; 7788 tp->ts_recent_age = cts; 7789 } 7790 if (to.to_flags & TOF_MSS) 7791 tcp_mss(tp, to.to_mss); 7792 if ((tp->t_flags & TF_SACK_PERMIT) && 7793 (to.to_flags & TOF_SACKPERM) == 0) 7794 tp->t_flags &= ~TF_SACK_PERMIT; 7795 if (IS_FASTOPEN(tp->t_flags)) { 7796 if (to.to_flags & TOF_FASTOPEN) { 7797 uint16_t mss; 7798 7799 if (to.to_flags & TOF_MSS) 7800 mss = to.to_mss; 7801 else 7802 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) 7803 mss = TCP6_MSS; 7804 else 7805 mss = TCP_MSS; 7806 tcp_fastopen_update_cache(tp, mss, 7807 to.to_tfo_len, to.to_tfo_cookie); 7808 } else 7809 tcp_fastopen_disable_path(tp); 7810 } 7811 } 7812 /* 7813 * At this point we are at the initial call. Here we decide 7814 * if we are doing RACK or not. We do this by seeing if 7815 * TF_SACK_PERMIT is set, if not rack is *not* possible and 7816 * we switch to the default code. 7817 */ 7818 if ((tp->t_flags & TF_SACK_PERMIT) == 0) { 7819 tcp_switch_back_to_default(tp); 7820 (*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen, 7821 tlen, iptos); 7822 return (1); 7823 } 7824 /* Set the flag */ 7825 rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0; 7826 tcp_set_hpts(tp->t_inpcb); 7827 sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack); 7828 } 7829 /* 7830 * This is the one exception case where we set the rack state 7831 * always. All other times (timers etc) we must have a rack-state 7832 * set (so we assure we have done the checks above for SACK). 7833 */ 7834 memcpy(&rack->r_ctl.rc_last_ack, tv, sizeof(struct timeval)); 7835 rack->r_ctl.rc_rcvtime = cts; 7836 if (rack->r_state != tp->t_state) 7837 rack_set_state(tp, rack); 7838 if (SEQ_GT(th->th_ack, tp->snd_una) && 7839 (rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL) 7840 kern_prefetch(rsm, &prev_state); 7841 prev_state = rack->r_state; 7842 rack->r_ctl.rc_tlp_send_cnt = 0; 7843 rack_clear_rate_sample(rack); 7844 retval = (*rack->r_substate) (m, th, so, 7845 tp, &to, drop_hdrlen, 7846 tlen, tiwin, thflags, nxt_pkt, iptos); 7847 #ifdef INVARIANTS 7848 if ((retval == 0) && 7849 (tp->t_inpcb == NULL)) { 7850 panic("retval:%d tp:%p t_inpcb:NULL state:%d", 7851 retval, tp, prev_state); 7852 } 7853 #endif 7854 if (retval == 0) { 7855 /* 7856 * If retval is 1 the tcb is unlocked and most likely the tp 7857 * is gone. 7858 */ 7859 INP_WLOCK_ASSERT(tp->t_inpcb); 7860 if (rack->set_pacing_done_a_iw == 0) { 7861 /* How much has been acked? */ 7862 if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) { 7863 /* We have enough to set in the pacing segment size */ 7864 rack->set_pacing_done_a_iw = 1; 7865 rack_set_pace_segments(tp, rack); 7866 } 7867 } 7868 tcp_rack_xmit_timer_commit(rack, tp); 7869 if ((nxt_pkt == 0) || (IN_RECOVERY(tp->t_flags))) { 7870 if (rack->r_wanted_output != 0) { 7871 did_out = 1; 7872 (void)tp->t_fb->tfb_tcp_output(tp); 7873 } 7874 rack_start_hpts_timer(rack, tp, cts, 0, 0, 0); 7875 } 7876 if ((nxt_pkt == 0) && 7877 ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) && 7878 (SEQ_GT(tp->snd_max, tp->snd_una) || 7879 (tp->t_flags & TF_DELACK) || 7880 ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) && 7881 (tp->t_state <= TCPS_CLOSING)))) { 7882 /* We could not send (probably in the hpts but stopped the timer earlier)? */ 7883 if ((tp->snd_max == tp->snd_una) && 7884 ((tp->t_flags & TF_DELACK) == 0) && 7885 (rack->rc_inp->inp_in_hpts) && 7886 (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) { 7887 /* keep alive not needed if we are hptsi output yet */ 7888 ; 7889 } else { 7890 if (rack->rc_inp->inp_in_hpts) { 7891 tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT); 7892 counter_u64_add(rack_per_timer_hole, 1); 7893 } 7894 rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0); 7895 } 7896 way_out = 1; 7897 } else if (nxt_pkt == 0) { 7898 /* Do we have the correct timer running? */ 7899 rack_timer_audit(tp, rack, &so->so_snd); 7900 way_out = 2; 7901 } 7902 done_with_input: 7903 rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out); 7904 if (did_out) 7905 rack->r_wanted_output = 0; 7906 #ifdef INVARIANTS 7907 if (tp->t_inpcb == NULL) { 7908 panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d", 7909 did_out, 7910 retval, tp, prev_state); 7911 } 7912 #endif 7913 } 7914 return (retval); 7915 } 7916 7917 void 7918 rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so, 7919 struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos) 7920 { 7921 struct timeval tv; 7922 7923 /* First lets see if we have old packets */ 7924 if (tp->t_in_pkt) { 7925 if (ctf_do_queued_segments(so, tp, 1)) { 7926 m_freem(m); 7927 return; 7928 } 7929 } 7930 if (m->m_flags & M_TSTMP_LRO) { 7931 tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000; 7932 tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000; 7933 } else { 7934 /* Should not be should we kassert instead? */ 7935 tcp_get_usecs(&tv); 7936 } 7937 if(rack_do_segment_nounlock(m, th, so, tp, 7938 drop_hdrlen, tlen, iptos, 0, &tv) == 0) 7939 INP_WUNLOCK(tp->t_inpcb); 7940 } 7941 7942 struct rack_sendmap * 7943 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused) 7944 { 7945 struct rack_sendmap *rsm = NULL; 7946 int32_t idx; 7947 uint32_t srtt = 0, thresh = 0, ts_low = 0; 7948 7949 /* Return the next guy to be re-transmitted */ 7950 if (RB_EMPTY(&rack->r_ctl.rc_mtree)) { 7951 return (NULL); 7952 } 7953 if (tp->t_flags & TF_SENTFIN) { 7954 /* retran the end FIN? */ 7955 return (NULL); 7956 } 7957 /* ok lets look at this one */ 7958 rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap); 7959 if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) { 7960 goto check_it; 7961 } 7962 rsm = rack_find_lowest_rsm(rack); 7963 if (rsm == NULL) { 7964 return (NULL); 7965 } 7966 check_it: 7967 if (rsm->r_flags & RACK_ACKED) { 7968 return (NULL); 7969 } 7970 if ((rsm->r_flags & RACK_SACK_PASSED) == 0) { 7971 /* Its not yet ready */ 7972 return (NULL); 7973 } 7974 srtt = rack_grab_rtt(tp, rack); 7975 idx = rsm->r_rtr_cnt - 1; 7976 ts_low = rsm->r_tim_lastsent[idx]; 7977 thresh = rack_calc_thresh_rack(rack, srtt, tsused); 7978 if ((tsused == ts_low) || 7979 (TSTMP_LT(tsused, ts_low))) { 7980 /* No time since sending */ 7981 return (NULL); 7982 } 7983 if ((tsused - ts_low) < thresh) { 7984 /* It has not been long enough yet */ 7985 return (NULL); 7986 } 7987 if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) || 7988 ((rsm->r_flags & RACK_SACK_PASSED) && 7989 (rack->sack_attack_disable == 0))) { 7990 /* 7991 * We have passed the dup-ack threshold <or> 7992 * a SACK has indicated this is missing. 7993 * Note that if you are a declared attacker 7994 * it is only the dup-ack threshold that 7995 * will cause retransmits. 7996 */ 7997 /* log retransmit reason */ 7998 rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1); 7999 return (rsm); 8000 } 8001 return (NULL); 8002 } 8003 8004 static int32_t 8005 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len) 8006 { 8007 int32_t slot = 0; 8008 8009 if ((rack->rack_per_of_gp == 0) || 8010 (rack->rc_always_pace == 0)) { 8011 /* 8012 * We use the most optimistic possible cwnd/srtt for 8013 * sending calculations. This will make our 8014 * calculation anticipate getting more through 8015 * quicker then possible. But thats ok we don't want 8016 * the peer to have a gap in data sending. 8017 */ 8018 uint32_t srtt, cwnd, tr_perms = 0; 8019 8020 old_method: 8021 if (rack->r_ctl.rc_rack_min_rtt) 8022 srtt = rack->r_ctl.rc_rack_min_rtt; 8023 else 8024 srtt = TICKS_2_MSEC((tp->t_srtt >> TCP_RTT_SHIFT)); 8025 if (rack->r_ctl.rc_rack_largest_cwnd) 8026 cwnd = rack->r_ctl.rc_rack_largest_cwnd; 8027 else 8028 cwnd = tp->snd_cwnd; 8029 tr_perms = cwnd / srtt; 8030 if (tr_perms == 0) { 8031 tr_perms = ctf_fixed_maxseg(tp); 8032 } 8033 /* 8034 * Calculate how long this will take to drain, if 8035 * the calculation comes out to zero, thats ok we 8036 * will use send_a_lot to possibly spin around for 8037 * more increasing tot_len_this_send to the point 8038 * that its going to require a pace, or we hit the 8039 * cwnd. Which in that case we are just waiting for 8040 * a ACK. 8041 */ 8042 slot = len / tr_perms; 8043 /* Now do we reduce the time so we don't run dry? */ 8044 if (slot && rack->rc_pace_reduce) { 8045 int32_t reduce; 8046 8047 reduce = (slot / rack->rc_pace_reduce); 8048 if (reduce < slot) { 8049 slot -= reduce; 8050 } else 8051 slot = 0; 8052 } 8053 } else { 8054 int cnt; 8055 uint64_t bw_est, bw_raise, res, lentim; 8056 8057 bw_est = 0; 8058 for (cnt=0; cnt<RACK_GP_HIST; cnt++) { 8059 if ((rack->r_ctl.rc_gp_hist_filled == 0) && 8060 (rack->r_ctl.rc_gp_history[cnt] == 0)) 8061 break; 8062 bw_est += rack->r_ctl.rc_gp_history[cnt]; 8063 } 8064 if (bw_est == 0) { 8065 /* 8066 * No way yet to make a b/w estimate 8067 * (no goodput est yet). 8068 */ 8069 goto old_method; 8070 } 8071 /* Covert to bytes per second */ 8072 bw_est *= MSEC_IN_SECOND; 8073 /* 8074 * Now ratchet it up by our percentage. Note 8075 * that the minimum you can do is 1 which would 8076 * get you 101% of the average last N goodput estimates. 8077 * The max you can do is 256 which would yeild you 8078 * 356% of the last N goodput estimates. 8079 */ 8080 bw_raise = bw_est * (uint64_t)rack->rack_per_of_gp; 8081 bw_est += bw_raise; 8082 /* average by the number we added */ 8083 bw_est /= cnt; 8084 /* Now calculate a rate based on this b/w */ 8085 lentim = (uint64_t) len * (uint64_t)MSEC_IN_SECOND; 8086 res = lentim / bw_est; 8087 slot = (uint32_t)res; 8088 } 8089 if (rack->r_enforce_min_pace && 8090 (slot == 0)) { 8091 /* We are enforcing a minimum pace time of 1ms */ 8092 slot = rack->r_enforce_min_pace; 8093 } 8094 if (slot) 8095 counter_u64_add(rack_calc_nonzero, 1); 8096 else 8097 counter_u64_add(rack_calc_zero, 1); 8098 return (slot); 8099 } 8100 8101 static int 8102 rack_output(struct tcpcb *tp) 8103 { 8104 struct socket *so; 8105 uint32_t recwin, sendwin; 8106 uint32_t sb_offset; 8107 int32_t len, flags, error = 0; 8108 struct mbuf *m; 8109 struct mbuf *mb; 8110 uint32_t if_hw_tsomaxsegcount = 0; 8111 uint32_t if_hw_tsomaxsegsize = 0; 8112 int32_t maxseg; 8113 long tot_len_this_send = 0; 8114 struct ip *ip = NULL; 8115 #ifdef TCPDEBUG 8116 struct ipovly *ipov = NULL; 8117 #endif 8118 struct udphdr *udp = NULL; 8119 struct tcp_rack *rack; 8120 struct tcphdr *th; 8121 uint8_t pass = 0; 8122 uint8_t wanted_cookie = 0; 8123 u_char opt[TCP_MAXOLEN]; 8124 unsigned ipoptlen, optlen, hdrlen, ulen=0; 8125 uint32_t rack_seq; 8126 8127 #if defined(IPSEC) || defined(IPSEC_SUPPORT) 8128 unsigned ipsec_optlen = 0; 8129 8130 #endif 8131 int32_t idle, sendalot; 8132 int32_t sub_from_prr = 0; 8133 volatile int32_t sack_rxmit; 8134 struct rack_sendmap *rsm = NULL; 8135 int32_t tso, mtu; 8136 struct tcpopt to; 8137 int32_t slot = 0; 8138 int32_t sup_rack = 0; 8139 uint32_t cts; 8140 uint8_t hpts_calling, new_data_tlp = 0, doing_tlp = 0; 8141 int32_t do_a_prefetch; 8142 int32_t prefetch_rsm = 0; 8143 int force_tso = 0; 8144 int32_t orig_len; 8145 int32_t prefetch_so_done = 0; 8146 struct tcp_log_buffer *lgb = NULL; 8147 struct inpcb *inp; 8148 struct sockbuf *sb; 8149 #ifdef INET6 8150 struct ip6_hdr *ip6 = NULL; 8151 int32_t isipv6; 8152 #endif 8153 uint8_t filled_all = 0; 8154 bool hw_tls = false; 8155 8156 /* setup and take the cache hits here */ 8157 rack = (struct tcp_rack *)tp->t_fb_ptr; 8158 inp = rack->rc_inp; 8159 so = inp->inp_socket; 8160 sb = &so->so_snd; 8161 kern_prefetch(sb, &do_a_prefetch); 8162 do_a_prefetch = 1; 8163 8164 #ifdef KERN_TLS 8165 hw_tls = (so->so_snd.sb_flags & SB_TLS_IFNET) != 0; 8166 #endif 8167 8168 NET_EPOCH_ASSERT(); 8169 INP_WLOCK_ASSERT(inp); 8170 8171 #ifdef TCP_OFFLOAD 8172 if (tp->t_flags & TF_TOE) 8173 return (tcp_offload_output(tp)); 8174 #endif 8175 maxseg = ctf_fixed_maxseg(tp); 8176 /* 8177 * For TFO connections in SYN_RECEIVED, only allow the initial 8178 * SYN|ACK and those sent by the retransmit timer. 8179 */ 8180 if (IS_FASTOPEN(tp->t_flags) && 8181 (tp->t_state == TCPS_SYN_RECEIVED) && 8182 SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN|ACK sent */ 8183 (rack->r_ctl.rc_resend == NULL)) /* not a retransmit */ 8184 return (0); 8185 #ifdef INET6 8186 if (rack->r_state) { 8187 /* Use the cache line loaded if possible */ 8188 isipv6 = rack->r_is_v6; 8189 } else { 8190 isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 8191 } 8192 #endif 8193 cts = tcp_ts_getticks(); 8194 if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) && 8195 inp->inp_in_hpts) { 8196 /* 8197 * We are on the hpts for some timer but not hptsi output. 8198 * Remove from the hpts unconditionally. 8199 */ 8200 rack_timer_cancel(tp, rack, cts, __LINE__); 8201 } 8202 /* Mark that we have called rack_output(). */ 8203 if ((rack->r_timer_override) || 8204 (tp->t_flags & TF_FORCEDATA) || 8205 (tp->t_state < TCPS_ESTABLISHED)) { 8206 if (tp->t_inpcb->inp_in_hpts) 8207 tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT); 8208 } else if (tp->t_inpcb->inp_in_hpts) { 8209 /* 8210 * On the hpts you can't pass even if ACKNOW is on, we will 8211 * when the hpts fires. 8212 */ 8213 counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1); 8214 return (0); 8215 } 8216 hpts_calling = inp->inp_hpts_calls; 8217 inp->inp_hpts_calls = 0; 8218 if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) { 8219 if (rack_process_timers(tp, rack, cts, hpts_calling)) { 8220 counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1); 8221 return (0); 8222 } 8223 } 8224 rack->r_wanted_output = 0; 8225 rack->r_timer_override = 0; 8226 /* 8227 * For TFO connections in SYN_SENT or SYN_RECEIVED, 8228 * only allow the initial SYN or SYN|ACK and those sent 8229 * by the retransmit timer. 8230 */ 8231 if (IS_FASTOPEN(tp->t_flags) && 8232 ((tp->t_state == TCPS_SYN_RECEIVED) || 8233 (tp->t_state == TCPS_SYN_SENT)) && 8234 SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */ 8235 (tp->t_rxtshift == 0)) /* not a retransmit */ 8236 return (0); 8237 /* 8238 * Determine length of data that should be transmitted, and flags 8239 * that will be used. If there is some data or critical controls 8240 * (SYN, RST) to send, then transmit; otherwise, investigate 8241 * further. 8242 */ 8243 idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una); 8244 if (tp->t_idle_reduce) { 8245 if (idle && ((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) 8246 rack_cc_after_idle(tp); 8247 } 8248 tp->t_flags &= ~TF_LASTIDLE; 8249 if (idle) { 8250 if (tp->t_flags & TF_MORETOCOME) { 8251 tp->t_flags |= TF_LASTIDLE; 8252 idle = 0; 8253 } 8254 } 8255 again: 8256 /* 8257 * If we've recently taken a timeout, snd_max will be greater than 8258 * snd_nxt. There may be SACK information that allows us to avoid 8259 * resending already delivered data. Adjust snd_nxt accordingly. 8260 */ 8261 sendalot = 0; 8262 cts = tcp_ts_getticks(); 8263 tso = 0; 8264 mtu = 0; 8265 sb_offset = tp->snd_max - tp->snd_una; 8266 sendwin = min(tp->snd_wnd, tp->snd_cwnd); 8267 8268 flags = tcp_outflags[tp->t_state]; 8269 while (rack->rc_free_cnt < rack_free_cache) { 8270 rsm = rack_alloc(rack); 8271 if (rsm == NULL) { 8272 if (inp->inp_hpts_calls) 8273 /* Retry in a ms */ 8274 slot = 1; 8275 goto just_return_nolock; 8276 } 8277 TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext); 8278 rack->rc_free_cnt++; 8279 rsm = NULL; 8280 } 8281 if (inp->inp_hpts_calls) 8282 inp->inp_hpts_calls = 0; 8283 sack_rxmit = 0; 8284 len = 0; 8285 rsm = NULL; 8286 if (flags & TH_RST) { 8287 SOCKBUF_LOCK(sb); 8288 goto send; 8289 } 8290 if (rack->r_ctl.rc_tlpsend) { 8291 /* Tail loss probe */ 8292 long cwin; 8293 long tlen; 8294 8295 doing_tlp = 1; 8296 /* 8297 * Check if we can do a TLP with a RACK'd packet 8298 * this can happen if we are not doing the rack 8299 * cheat and we skipped to a TLP and it 8300 * went off. 8301 */ 8302 rsm = tcp_rack_output(tp, rack, cts); 8303 if (rsm == NULL) 8304 rsm = rack->r_ctl.rc_tlpsend; 8305 rack->r_ctl.rc_tlpsend = NULL; 8306 sack_rxmit = 1; 8307 tlen = rsm->r_end - rsm->r_start; 8308 if (tlen > ctf_fixed_maxseg(tp)) 8309 tlen = ctf_fixed_maxseg(tp); 8310 KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start), 8311 ("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p", 8312 __func__, __LINE__, 8313 rsm->r_start, tp->snd_una, tp, rack, rsm)); 8314 sb_offset = rsm->r_start - tp->snd_una; 8315 cwin = min(tp->snd_wnd, tlen); 8316 len = cwin; 8317 } else if (rack->r_ctl.rc_resend) { 8318 /* Retransmit timer */ 8319 rsm = rack->r_ctl.rc_resend; 8320 rack->r_ctl.rc_resend = NULL; 8321 len = rsm->r_end - rsm->r_start; 8322 sack_rxmit = 1; 8323 sendalot = 0; 8324 KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start), 8325 ("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p", 8326 __func__, __LINE__, 8327 rsm->r_start, tp->snd_una, tp, rack, rsm)); 8328 sb_offset = rsm->r_start - tp->snd_una; 8329 if (len >= ctf_fixed_maxseg(tp)) { 8330 len = ctf_fixed_maxseg(tp); 8331 } 8332 } else if ((rack->rc_in_persist == 0) && 8333 ((rsm = tcp_rack_output(tp, rack, cts)) != NULL)) { 8334 int maxseg; 8335 8336 maxseg = ctf_fixed_maxseg(tp); 8337 if ((!IN_RECOVERY(tp->t_flags)) && 8338 ((tp->t_flags & (TF_WASFRECOVERY | TF_WASCRECOVERY)) == 0)) { 8339 /* Enter recovery if not induced by a time-out */ 8340 rack->r_ctl.rc_rsm_start = rsm->r_start; 8341 rack->r_ctl.rc_cwnd_at = tp->snd_cwnd; 8342 rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh; 8343 rack_cong_signal(tp, NULL, CC_NDUPACK); 8344 /* 8345 * When we enter recovery we need to assure we send 8346 * one packet. 8347 */ 8348 rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp); 8349 rack_log_to_prr(rack, 13); 8350 } 8351 #ifdef INVARIANTS 8352 if (SEQ_LT(rsm->r_start, tp->snd_una)) { 8353 panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n", 8354 tp, rack, rsm, rsm->r_start, tp->snd_una); 8355 } 8356 #endif 8357 len = rsm->r_end - rsm->r_start; 8358 KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start), 8359 ("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p", 8360 __func__, __LINE__, 8361 rsm->r_start, tp->snd_una, tp, rack, rsm)); 8362 sb_offset = rsm->r_start - tp->snd_una; 8363 /* Can we send it within the PRR boundary? */ 8364 if ((rack->use_rack_cheat == 0) && (len > rack->r_ctl.rc_prr_sndcnt)) { 8365 /* It does not fit */ 8366 if ((ctf_flight_size(tp, rack->r_ctl.rc_sacked) > len) && 8367 (rack->r_ctl.rc_prr_sndcnt < maxseg)) { 8368 /* 8369 * prr is less than a segment, we 8370 * have more acks due in besides 8371 * what we need to resend. Lets not send 8372 * to avoid sending small pieces of 8373 * what we need to retransmit. 8374 */ 8375 len = 0; 8376 goto just_return_nolock; 8377 } 8378 len = rack->r_ctl.rc_prr_sndcnt; 8379 } 8380 sendalot = 0; 8381 if (len >= maxseg) { 8382 len = maxseg; 8383 } 8384 if (len > 0) { 8385 sub_from_prr = 1; 8386 sack_rxmit = 1; 8387 KMOD_TCPSTAT_INC(tcps_sack_rexmits); 8388 KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes, 8389 min(len, ctf_fixed_maxseg(tp))); 8390 counter_u64_add(rack_rtm_prr_retran, 1); 8391 } 8392 } 8393 /* 8394 * Enforce a connection sendmap count limit if set 8395 * as long as we are not retransmiting. 8396 */ 8397 if ((rsm == NULL) && 8398 (rack->do_detection == 0) && 8399 (V_tcp_map_entries_limit > 0) && 8400 (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) { 8401 counter_u64_add(rack_to_alloc_limited, 1); 8402 if (!rack->alloc_limit_reported) { 8403 rack->alloc_limit_reported = 1; 8404 counter_u64_add(rack_alloc_limited_conns, 1); 8405 } 8406 goto just_return_nolock; 8407 } 8408 if (rsm && (rsm->r_flags & RACK_HAS_FIN)) { 8409 /* we are retransmitting the fin */ 8410 len--; 8411 if (len) { 8412 /* 8413 * When retransmitting data do *not* include the 8414 * FIN. This could happen from a TLP probe. 8415 */ 8416 flags &= ~TH_FIN; 8417 } 8418 } 8419 #ifdef INVARIANTS 8420 /* For debugging */ 8421 rack->r_ctl.rc_rsm_at_retran = rsm; 8422 #endif 8423 /* 8424 * Get standard flags, and add SYN or FIN if requested by 'hidden' 8425 * state flags. 8426 */ 8427 if (tp->t_flags & TF_NEEDFIN) 8428 flags |= TH_FIN; 8429 if (tp->t_flags & TF_NEEDSYN) 8430 flags |= TH_SYN; 8431 if ((sack_rxmit == 0) && (prefetch_rsm == 0)) { 8432 void *end_rsm; 8433 end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext); 8434 if (end_rsm) 8435 kern_prefetch(end_rsm, &prefetch_rsm); 8436 prefetch_rsm = 1; 8437 } 8438 SOCKBUF_LOCK(sb); 8439 /* 8440 * If in persist timeout with window of 0, send 1 byte. Otherwise, 8441 * if window is small but nonzero and time TF_SENTFIN expired, we 8442 * will send what we can and go to transmit state. 8443 */ 8444 if (tp->t_flags & TF_FORCEDATA) { 8445 if (sendwin == 0) { 8446 /* 8447 * If we still have some data to send, then clear 8448 * the FIN bit. Usually this would happen below 8449 * when it realizes that we aren't sending all the 8450 * data. However, if we have exactly 1 byte of 8451 * unsent data, then it won't clear the FIN bit 8452 * below, and if we are in persist state, we wind up 8453 * sending the packet without recording that we sent 8454 * the FIN bit. 8455 * 8456 * We can't just blindly clear the FIN bit, because 8457 * if we don't have any more data to send then the 8458 * probe will be the FIN itself. 8459 */ 8460 if (sb_offset < sbused(sb)) 8461 flags &= ~TH_FIN; 8462 sendwin = 1; 8463 } else { 8464 if ((rack->rc_in_persist != 0) && 8465 (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2), 8466 rack->r_ctl.rc_pace_min_segs))) 8467 rack_exit_persist(tp, rack); 8468 /* 8469 * If we are dropping persist mode then we need to 8470 * correct snd_nxt/snd_max and off. 8471 */ 8472 tp->snd_nxt = tp->snd_max; 8473 sb_offset = tp->snd_nxt - tp->snd_una; 8474 } 8475 } 8476 /* 8477 * If snd_nxt == snd_max and we have transmitted a FIN, the 8478 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a 8479 * negative length. This can also occur when TCP opens up its 8480 * congestion window while receiving additional duplicate acks after 8481 * fast-retransmit because TCP will reset snd_nxt to snd_max after 8482 * the fast-retransmit. 8483 * 8484 * In the normal retransmit-FIN-only case, however, snd_nxt will be 8485 * set to snd_una, the sb_offset will be 0, and the length may wind 8486 * up 0. 8487 * 8488 * If sack_rxmit is true we are retransmitting from the scoreboard 8489 * in which case len is already set. 8490 */ 8491 if (sack_rxmit == 0) { 8492 uint32_t avail; 8493 8494 avail = sbavail(sb); 8495 if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail) 8496 sb_offset = tp->snd_nxt - tp->snd_una; 8497 else 8498 sb_offset = 0; 8499 if (IN_RECOVERY(tp->t_flags) == 0) { 8500 if (rack->r_ctl.rc_tlp_new_data) { 8501 /* TLP is forcing out new data */ 8502 if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) { 8503 rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset); 8504 } 8505 if (rack->r_ctl.rc_tlp_new_data > tp->snd_wnd) 8506 len = tp->snd_wnd; 8507 else 8508 len = rack->r_ctl.rc_tlp_new_data; 8509 rack->r_ctl.rc_tlp_new_data = 0; 8510 new_data_tlp = doing_tlp = 1; 8511 } else { 8512 if (sendwin > avail) { 8513 /* use the available */ 8514 if (avail > sb_offset) { 8515 len = (int32_t)(avail - sb_offset); 8516 } else { 8517 len = 0; 8518 } 8519 } else { 8520 if (sendwin > sb_offset) { 8521 len = (int32_t)(sendwin - sb_offset); 8522 } else { 8523 len = 0; 8524 } 8525 } 8526 } 8527 } else { 8528 uint32_t outstanding; 8529 8530 /* 8531 * We are inside of a SACK recovery episode and are 8532 * sending new data, having retransmitted all the 8533 * data possible so far in the scoreboard. 8534 */ 8535 outstanding = tp->snd_max - tp->snd_una; 8536 if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) { 8537 if (tp->snd_wnd > outstanding) { 8538 len = tp->snd_wnd - outstanding; 8539 /* Check to see if we have the data */ 8540 if (((sb_offset + len) > avail) && 8541 (avail > sb_offset)) 8542 len = avail - sb_offset; 8543 else 8544 len = 0; 8545 } else 8546 len = 0; 8547 } else if (avail > sb_offset) 8548 len = avail - sb_offset; 8549 else 8550 len = 0; 8551 if (len > 0) { 8552 if (len > rack->r_ctl.rc_prr_sndcnt) 8553 len = rack->r_ctl.rc_prr_sndcnt; 8554 if (len > 0) { 8555 sub_from_prr = 1; 8556 counter_u64_add(rack_rtm_prr_newdata, 1); 8557 } 8558 } 8559 if (len > ctf_fixed_maxseg(tp)) { 8560 /* 8561 * We should never send more than a MSS when 8562 * retransmitting or sending new data in prr 8563 * mode unless the override flag is on. Most 8564 * likely the PRR algorithm is not going to 8565 * let us send a lot as well :-) 8566 */ 8567 if (rack->r_ctl.rc_prr_sendalot == 0) 8568 len = ctf_fixed_maxseg(tp); 8569 } else if (len < ctf_fixed_maxseg(tp)) { 8570 /* 8571 * Do we send any? The idea here is if the 8572 * send empty's the socket buffer we want to 8573 * do it. However if not then lets just wait 8574 * for our prr_sndcnt to get bigger. 8575 */ 8576 long leftinsb; 8577 8578 leftinsb = sbavail(sb) - sb_offset; 8579 if (leftinsb > len) { 8580 /* This send does not empty the sb */ 8581 len = 0; 8582 } 8583 } 8584 } 8585 } 8586 if (prefetch_so_done == 0) { 8587 kern_prefetch(so, &prefetch_so_done); 8588 prefetch_so_done = 1; 8589 } 8590 /* 8591 * Lop off SYN bit if it has already been sent. However, if this is 8592 * SYN-SENT state and if segment contains data and if we don't know 8593 * that foreign host supports TAO, suppress sending segment. 8594 */ 8595 if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) && 8596 ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) { 8597 if (tp->t_state != TCPS_SYN_RECEIVED) 8598 flags &= ~TH_SYN; 8599 /* 8600 * When sending additional segments following a TFO SYN|ACK, 8601 * do not include the SYN bit. 8602 */ 8603 if (IS_FASTOPEN(tp->t_flags) && 8604 (tp->t_state == TCPS_SYN_RECEIVED)) 8605 flags &= ~TH_SYN; 8606 sb_offset--, len++; 8607 } 8608 /* 8609 * Be careful not to send data and/or FIN on SYN segments. This 8610 * measure is needed to prevent interoperability problems with not 8611 * fully conformant TCP implementations. 8612 */ 8613 if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) { 8614 len = 0; 8615 flags &= ~TH_FIN; 8616 } 8617 /* 8618 * On TFO sockets, ensure no data is sent in the following cases: 8619 * 8620 * - When retransmitting SYN|ACK on a passively-created socket 8621 * 8622 * - When retransmitting SYN on an actively created socket 8623 * 8624 * - When sending a zero-length cookie (cookie request) on an 8625 * actively created socket 8626 * 8627 * - When the socket is in the CLOSED state (RST is being sent) 8628 */ 8629 if (IS_FASTOPEN(tp->t_flags) && 8630 (((flags & TH_SYN) && (tp->t_rxtshift > 0)) || 8631 ((tp->t_state == TCPS_SYN_SENT) && 8632 (tp->t_tfo_client_cookie_len == 0)) || 8633 (flags & TH_RST))) { 8634 sack_rxmit = 0; 8635 len = 0; 8636 } 8637 /* Without fast-open there should never be data sent on a SYN */ 8638 if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) 8639 len = 0; 8640 orig_len = len; 8641 if (len <= 0) { 8642 /* 8643 * If FIN has been sent but not acked, but we haven't been 8644 * called to retransmit, len will be < 0. Otherwise, window 8645 * shrank after we sent into it. If window shrank to 0, 8646 * cancel pending retransmit, pull snd_nxt back to (closed) 8647 * window, and set the persist timer if it isn't already 8648 * going. If the window didn't close completely, just wait 8649 * for an ACK. 8650 * 8651 * We also do a general check here to ensure that we will 8652 * set the persist timer when we have data to send, but a 8653 * 0-byte window. This makes sure the persist timer is set 8654 * even if the packet hits one of the "goto send" lines 8655 * below. 8656 */ 8657 len = 0; 8658 if ((tp->snd_wnd == 0) && 8659 (TCPS_HAVEESTABLISHED(tp->t_state)) && 8660 (tp->snd_una == tp->snd_max) && 8661 (sb_offset < (int)sbavail(sb))) { 8662 tp->snd_nxt = tp->snd_una; 8663 rack_enter_persist(tp, rack, cts); 8664 } 8665 } else if ((rsm == NULL) && 8666 ((doing_tlp == 0) || (new_data_tlp == 1)) && 8667 (len < rack->r_ctl.rc_pace_max_segs)) { 8668 /* 8669 * We are not sending a full segment for 8670 * some reason. Should we not send anything (think 8671 * sws or persists)? 8672 */ 8673 if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) && 8674 (TCPS_HAVEESTABLISHED(tp->t_state)) && 8675 (len < (int)(sbavail(sb) - sb_offset))) { 8676 /* 8677 * Here the rwnd is less than 8678 * the pacing size, this is not a retransmit, 8679 * we are established and 8680 * the send is not the last in the socket buffer 8681 * we send nothing, and may enter persists. 8682 */ 8683 len = 0; 8684 if (tp->snd_max == tp->snd_una) { 8685 /* 8686 * Nothing out we can 8687 * go into persists. 8688 */ 8689 rack_enter_persist(tp, rack, cts); 8690 tp->snd_nxt = tp->snd_una; 8691 } 8692 } else if ((tp->snd_cwnd >= max(rack->r_ctl.rc_pace_min_segs, (maxseg * 4))) && 8693 (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * maxseg)) && 8694 (len < (int)(sbavail(sb) - sb_offset)) && 8695 (len < rack->r_ctl.rc_pace_min_segs)) { 8696 /* 8697 * Here we are not retransmitting, and 8698 * the cwnd is not so small that we could 8699 * not send at least a min size (rxt timer 8700 * not having gone off), We have 2 segments or 8701 * more already in flight, its not the tail end 8702 * of the socket buffer and the cwnd is blocking 8703 * us from sending out a minimum pacing segment size. 8704 * Lets not send anything. 8705 */ 8706 len = 0; 8707 } else if (((tp->snd_wnd - ctf_outstanding(tp)) < 8708 min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) && 8709 (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * maxseg)) && 8710 (len < (int)(sbavail(sb) - sb_offset)) && 8711 (TCPS_HAVEESTABLISHED(tp->t_state))) { 8712 /* 8713 * Here we have a send window but we have 8714 * filled it up and we can't send another pacing segment. 8715 * We also have in flight more than 2 segments 8716 * and we are not completing the sb i.e. we allow 8717 * the last bytes of the sb to go out even if 8718 * its not a full pacing segment. 8719 */ 8720 len = 0; 8721 } 8722 } 8723 /* len will be >= 0 after this point. */ 8724 KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__)); 8725 tcp_sndbuf_autoscale(tp, so, sendwin); 8726 /* 8727 * Decide if we can use TCP Segmentation Offloading (if supported by 8728 * hardware). 8729 * 8730 * TSO may only be used if we are in a pure bulk sending state. The 8731 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP 8732 * options prevent using TSO. With TSO the TCP header is the same 8733 * (except for the sequence number) for all generated packets. This 8734 * makes it impossible to transmit any options which vary per 8735 * generated segment or packet. 8736 * 8737 * IPv4 handling has a clear separation of ip options and ip header 8738 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does 8739 * the right thing below to provide length of just ip options and thus 8740 * checking for ipoptlen is enough to decide if ip options are present. 8741 */ 8742 8743 #ifdef INET6 8744 if (isipv6) 8745 ipoptlen = ip6_optlen(tp->t_inpcb); 8746 else 8747 #endif 8748 if (tp->t_inpcb->inp_options) 8749 ipoptlen = tp->t_inpcb->inp_options->m_len - 8750 offsetof(struct ipoption, ipopt_list); 8751 else 8752 ipoptlen = 0; 8753 #if defined(IPSEC) || defined(IPSEC_SUPPORT) 8754 /* 8755 * Pre-calculate here as we save another lookup into the darknesses 8756 * of IPsec that way and can actually decide if TSO is ok. 8757 */ 8758 #ifdef INET6 8759 if (isipv6 && IPSEC_ENABLED(ipv6)) 8760 ipsec_optlen = IPSEC_HDRSIZE(ipv6, tp->t_inpcb); 8761 #ifdef INET 8762 else 8763 #endif 8764 #endif /* INET6 */ 8765 #ifdef INET 8766 if (IPSEC_ENABLED(ipv4)) 8767 ipsec_optlen = IPSEC_HDRSIZE(ipv4, tp->t_inpcb); 8768 #endif /* INET */ 8769 #endif 8770 8771 #if defined(IPSEC) || defined(IPSEC_SUPPORT) 8772 ipoptlen += ipsec_optlen; 8773 #endif 8774 if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > ctf_fixed_maxseg(tp) && 8775 (tp->t_port == 0) && 8776 ((tp->t_flags & TF_SIGNATURE) == 0) && 8777 tp->rcv_numsacks == 0 && sack_rxmit == 0 && 8778 ipoptlen == 0) 8779 tso = 1; 8780 { 8781 uint32_t outstanding; 8782 8783 outstanding = tp->snd_max - tp->snd_una; 8784 if (tp->t_flags & TF_SENTFIN) { 8785 /* 8786 * If we sent a fin, snd_max is 1 higher than 8787 * snd_una 8788 */ 8789 outstanding--; 8790 } 8791 if (sack_rxmit) { 8792 if ((rsm->r_flags & RACK_HAS_FIN) == 0) 8793 flags &= ~TH_FIN; 8794 } else { 8795 if (SEQ_LT(tp->snd_nxt + len, tp->snd_una + 8796 sbused(sb))) 8797 flags &= ~TH_FIN; 8798 } 8799 } 8800 recwin = sbspace(&so->so_rcv); 8801 8802 /* 8803 * Sender silly window avoidance. We transmit under the following 8804 * conditions when len is non-zero: 8805 * 8806 * - We have a full segment (or more with TSO) - This is the last 8807 * buffer in a write()/send() and we are either idle or running 8808 * NODELAY - we've timed out (e.g. persist timer) - we have more 8809 * then 1/2 the maximum send window's worth of data (receiver may be 8810 * limited the window size) - we need to retransmit 8811 */ 8812 if (len) { 8813 if (len >= ctf_fixed_maxseg(tp)) { 8814 pass = 1; 8815 goto send; 8816 } 8817 /* 8818 * NOTE! on localhost connections an 'ack' from the remote 8819 * end may occur synchronously with the output and cause us 8820 * to flush a buffer queued with moretocome. XXX 8821 * 8822 */ 8823 if (!(tp->t_flags & TF_MORETOCOME) && /* normal case */ 8824 (idle || (tp->t_flags & TF_NODELAY)) && 8825 ((uint32_t)len + (uint32_t)sb_offset >= sbavail(&so->so_snd)) && 8826 (tp->t_flags & TF_NOPUSH) == 0) { 8827 pass = 2; 8828 goto send; 8829 } 8830 if (tp->t_flags & TF_FORCEDATA) { /* typ. timeout case */ 8831 pass = 3; 8832 goto send; 8833 } 8834 if ((tp->snd_una == tp->snd_max) && len) { /* Nothing outstanding */ 8835 goto send; 8836 } 8837 if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) { 8838 pass = 4; 8839 goto send; 8840 } 8841 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) { /* retransmit case */ 8842 pass = 5; 8843 goto send; 8844 } 8845 if (sack_rxmit) { 8846 pass = 6; 8847 goto send; 8848 } 8849 } 8850 /* 8851 * Sending of standalone window updates. 8852 * 8853 * Window updates are important when we close our window due to a 8854 * full socket buffer and are opening it again after the application 8855 * reads data from it. Once the window has opened again and the 8856 * remote end starts to send again the ACK clock takes over and 8857 * provides the most current window information. 8858 * 8859 * We must avoid the silly window syndrome whereas every read from 8860 * the receive buffer, no matter how small, causes a window update 8861 * to be sent. We also should avoid sending a flurry of window 8862 * updates when the socket buffer had queued a lot of data and the 8863 * application is doing small reads. 8864 * 8865 * Prevent a flurry of pointless window updates by only sending an 8866 * update when we can increase the advertized window by more than 8867 * 1/4th of the socket buffer capacity. When the buffer is getting 8868 * full or is very small be more aggressive and send an update 8869 * whenever we can increase by two mss sized segments. In all other 8870 * situations the ACK's to new incoming data will carry further 8871 * window increases. 8872 * 8873 * Don't send an independent window update if a delayed ACK is 8874 * pending (it will get piggy-backed on it) or the remote side 8875 * already has done a half-close and won't send more data. Skip 8876 * this if the connection is in T/TCP half-open state. 8877 */ 8878 if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) && 8879 !(tp->t_flags & TF_DELACK) && 8880 !TCPS_HAVERCVDFIN(tp->t_state)) { 8881 /* 8882 * "adv" is the amount we could increase the window, taking 8883 * into account that we are limited by TCP_MAXWIN << 8884 * tp->rcv_scale. 8885 */ 8886 int32_t adv; 8887 int oldwin; 8888 8889 adv = min(recwin, (long)TCP_MAXWIN << tp->rcv_scale); 8890 if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) { 8891 oldwin = (tp->rcv_adv - tp->rcv_nxt); 8892 adv -= oldwin; 8893 } else 8894 oldwin = 0; 8895 8896 /* 8897 * If the new window size ends up being the same as the old 8898 * size when it is scaled, then don't force a window update. 8899 */ 8900 if (oldwin >> tp->rcv_scale == (adv + oldwin) >> tp->rcv_scale) 8901 goto dontupdate; 8902 8903 if (adv >= (int32_t)(2 * ctf_fixed_maxseg(tp)) && 8904 (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) || 8905 recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) || 8906 so->so_rcv.sb_hiwat <= 8 * ctf_fixed_maxseg(tp))) { 8907 pass = 7; 8908 goto send; 8909 } 8910 if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) 8911 goto send; 8912 } 8913 dontupdate: 8914 8915 /* 8916 * Send if we owe the peer an ACK, RST, SYN, or urgent data. ACKNOW 8917 * is also a catch-all for the retransmit timer timeout case. 8918 */ 8919 if (tp->t_flags & TF_ACKNOW) { 8920 pass = 8; 8921 goto send; 8922 } 8923 if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) { 8924 pass = 9; 8925 goto send; 8926 } 8927 if (SEQ_GT(tp->snd_up, tp->snd_una)) { 8928 pass = 10; 8929 goto send; 8930 } 8931 /* 8932 * If our state indicates that FIN should be sent and we have not 8933 * yet done so, then we need to send. 8934 */ 8935 if ((flags & TH_FIN) && 8936 (tp->snd_nxt == tp->snd_una)) { 8937 pass = 11; 8938 goto send; 8939 } 8940 /* 8941 * No reason to send a segment, just return. 8942 */ 8943 just_return: 8944 SOCKBUF_UNLOCK(sb); 8945 just_return_nolock: 8946 if (tot_len_this_send == 0) 8947 counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1); 8948 if (slot) { 8949 /* set the rack tcb into the slot N */ 8950 counter_u64_add(rack_paced_segments, 1); 8951 } else if (tot_len_this_send) { 8952 counter_u64_add(rack_unpaced_segments, 1); 8953 } 8954 /* Check if we need to go into persists or not */ 8955 if ((rack->rc_in_persist == 0) && 8956 (tp->snd_max == tp->snd_una) && 8957 TCPS_HAVEESTABLISHED(tp->t_state) && 8958 sbavail(&tp->t_inpcb->inp_socket->so_snd) && 8959 (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd) && 8960 (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs))) { 8961 /* Yes lets make sure to move to persist before timer-start */ 8962 rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime); 8963 } 8964 rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack); 8965 rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling); 8966 tp->t_flags &= ~TF_FORCEDATA; 8967 return (0); 8968 8969 send: 8970 if ((flags & TH_FIN) && 8971 sbavail(&tp->t_inpcb->inp_socket->so_snd)) { 8972 /* 8973 * We do not transmit a FIN 8974 * with data outstanding. We 8975 * need to make it so all data 8976 * is acked first. 8977 */ 8978 flags &= ~TH_FIN; 8979 } 8980 if (doing_tlp == 0) { 8981 /* 8982 * Data not a TLP, and its not the rxt firing. If it is the 8983 * rxt firing, we want to leave the tlp_in_progress flag on 8984 * so we don't send another TLP. It has to be a rack timer 8985 * or normal send (response to acked data) to clear the tlp 8986 * in progress flag. 8987 */ 8988 rack->rc_tlp_in_progress = 0; 8989 } 8990 SOCKBUF_LOCK_ASSERT(sb); 8991 if (len > 0) { 8992 if (len >= ctf_fixed_maxseg(tp)) 8993 tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT; 8994 else 8995 tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT; 8996 } 8997 /* 8998 * Before ESTABLISHED, force sending of initial options unless TCP 8999 * set not to do any options. NOTE: we assume that the IP/TCP header 9000 * plus TCP options always fit in a single mbuf, leaving room for a 9001 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr) 9002 * + optlen <= MCLBYTES 9003 */ 9004 optlen = 0; 9005 #ifdef INET6 9006 if (isipv6) 9007 hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 9008 else 9009 #endif 9010 hdrlen = sizeof(struct tcpiphdr); 9011 9012 /* 9013 * Compute options for segment. We only have to care about SYN and 9014 * established connection segments. Options for SYN-ACK segments 9015 * are handled in TCP syncache. 9016 */ 9017 to.to_flags = 0; 9018 if ((tp->t_flags & TF_NOOPT) == 0) { 9019 /* Maximum segment size. */ 9020 if (flags & TH_SYN) { 9021 tp->snd_nxt = tp->iss; 9022 to.to_mss = tcp_mssopt(&inp->inp_inc); 9023 #ifdef NETFLIX_TCPOUDP 9024 if (tp->t_port) 9025 to.to_mss -= V_tcp_udp_tunneling_overhead; 9026 #endif 9027 to.to_flags |= TOF_MSS; 9028 9029 /* 9030 * On SYN or SYN|ACK transmits on TFO connections, 9031 * only include the TFO option if it is not a 9032 * retransmit, as the presence of the TFO option may 9033 * have caused the original SYN or SYN|ACK to have 9034 * been dropped by a middlebox. 9035 */ 9036 if (IS_FASTOPEN(tp->t_flags) && 9037 (tp->t_rxtshift == 0)) { 9038 if (tp->t_state == TCPS_SYN_RECEIVED) { 9039 to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN; 9040 to.to_tfo_cookie = 9041 (u_int8_t *)&tp->t_tfo_cookie.server; 9042 to.to_flags |= TOF_FASTOPEN; 9043 wanted_cookie = 1; 9044 } else if (tp->t_state == TCPS_SYN_SENT) { 9045 to.to_tfo_len = 9046 tp->t_tfo_client_cookie_len; 9047 to.to_tfo_cookie = 9048 tp->t_tfo_cookie.client; 9049 to.to_flags |= TOF_FASTOPEN; 9050 wanted_cookie = 1; 9051 /* 9052 * If we wind up having more data to 9053 * send with the SYN than can fit in 9054 * one segment, don't send any more 9055 * until the SYN|ACK comes back from 9056 * the other end. 9057 */ 9058 sendalot = 0; 9059 } 9060 } 9061 } 9062 /* Window scaling. */ 9063 if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) { 9064 to.to_wscale = tp->request_r_scale; 9065 to.to_flags |= TOF_SCALE; 9066 } 9067 /* Timestamps. */ 9068 if ((tp->t_flags & TF_RCVD_TSTMP) || 9069 ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) { 9070 to.to_tsval = cts + tp->ts_offset; 9071 to.to_tsecr = tp->ts_recent; 9072 to.to_flags |= TOF_TS; 9073 } 9074 /* Set receive buffer autosizing timestamp. */ 9075 if (tp->rfbuf_ts == 0 && 9076 (so->so_rcv.sb_flags & SB_AUTOSIZE)) 9077 tp->rfbuf_ts = tcp_ts_getticks(); 9078 /* Selective ACK's. */ 9079 if (flags & TH_SYN) 9080 to.to_flags |= TOF_SACKPERM; 9081 else if (TCPS_HAVEESTABLISHED(tp->t_state) && 9082 tp->rcv_numsacks > 0) { 9083 to.to_flags |= TOF_SACK; 9084 to.to_nsacks = tp->rcv_numsacks; 9085 to.to_sacks = (u_char *)tp->sackblks; 9086 } 9087 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 9088 /* TCP-MD5 (RFC2385). */ 9089 if (tp->t_flags & TF_SIGNATURE) 9090 to.to_flags |= TOF_SIGNATURE; 9091 #endif /* TCP_SIGNATURE */ 9092 9093 /* Processing the options. */ 9094 hdrlen += optlen = tcp_addoptions(&to, opt); 9095 /* 9096 * If we wanted a TFO option to be added, but it was unable 9097 * to fit, ensure no data is sent. 9098 */ 9099 if (IS_FASTOPEN(tp->t_flags) && wanted_cookie && 9100 !(to.to_flags & TOF_FASTOPEN)) 9101 len = 0; 9102 } 9103 #ifdef NETFLIX_TCPOUDP 9104 if (tp->t_port) { 9105 if (V_tcp_udp_tunneling_port == 0) { 9106 /* The port was removed?? */ 9107 SOCKBUF_UNLOCK(&so->so_snd); 9108 return (EHOSTUNREACH); 9109 } 9110 hdrlen += sizeof(struct udphdr); 9111 } 9112 #endif 9113 #ifdef INET6 9114 if (isipv6) 9115 ipoptlen = ip6_optlen(tp->t_inpcb); 9116 else 9117 #endif 9118 if (tp->t_inpcb->inp_options) 9119 ipoptlen = tp->t_inpcb->inp_options->m_len - 9120 offsetof(struct ipoption, ipopt_list); 9121 else 9122 ipoptlen = 0; 9123 #if defined(IPSEC) || defined(IPSEC_SUPPORT) 9124 ipoptlen += ipsec_optlen; 9125 #endif 9126 9127 #ifdef KERN_TLS 9128 /* force TSO for so TLS offload can get mss */ 9129 if (sb->sb_flags & SB_TLS_IFNET) { 9130 force_tso = 1; 9131 } 9132 #endif 9133 /* 9134 * Adjust data length if insertion of options will bump the packet 9135 * length beyond the t_maxseg length. Clear the FIN bit because we 9136 * cut off the tail of the segment. 9137 */ 9138 if (len + optlen + ipoptlen > tp->t_maxseg) { 9139 if (tso) { 9140 uint32_t if_hw_tsomax; 9141 uint32_t moff; 9142 int32_t max_len; 9143 9144 /* extract TSO information */ 9145 if_hw_tsomax = tp->t_tsomax; 9146 if_hw_tsomaxsegcount = tp->t_tsomaxsegcount; 9147 if_hw_tsomaxsegsize = tp->t_tsomaxsegsize; 9148 KASSERT(ipoptlen == 0, 9149 ("%s: TSO can't do IP options", __func__)); 9150 9151 /* 9152 * Check if we should limit by maximum payload 9153 * length: 9154 */ 9155 if (if_hw_tsomax != 0) { 9156 /* compute maximum TSO length */ 9157 max_len = (if_hw_tsomax - hdrlen - 9158 max_linkhdr); 9159 if (max_len <= 0) { 9160 len = 0; 9161 } else if (len > max_len) { 9162 sendalot = 1; 9163 len = max_len; 9164 } 9165 } 9166 /* 9167 * Prevent the last segment from being fractional 9168 * unless the send sockbuf can be emptied: 9169 */ 9170 max_len = (tp->t_maxseg - optlen); 9171 if (((sb_offset + len) < sbavail(sb)) && 9172 (hw_tls == 0)) { 9173 moff = len % (u_int)max_len; 9174 if (moff != 0) { 9175 len -= moff; 9176 sendalot = 1; 9177 } 9178 } 9179 /* 9180 * In case there are too many small fragments don't 9181 * use TSO: 9182 */ 9183 if (len <= maxseg) { 9184 len = max_len; 9185 sendalot = 1; 9186 tso = 0; 9187 } 9188 /* 9189 * Send the FIN in a separate segment after the bulk 9190 * sending is done. We don't trust the TSO 9191 * implementations to clear the FIN flag on all but 9192 * the last segment. 9193 */ 9194 if (tp->t_flags & TF_NEEDFIN) 9195 sendalot = 1; 9196 9197 } else { 9198 if (optlen + ipoptlen >= tp->t_maxseg) { 9199 /* 9200 * Since we don't have enough space to put 9201 * the IP header chain and the TCP header in 9202 * one packet as required by RFC 7112, don't 9203 * send it. Also ensure that at least one 9204 * byte of the payload can be put into the 9205 * TCP segment. 9206 */ 9207 SOCKBUF_UNLOCK(&so->so_snd); 9208 error = EMSGSIZE; 9209 sack_rxmit = 0; 9210 goto out; 9211 } 9212 len = tp->t_maxseg - optlen - ipoptlen; 9213 sendalot = 1; 9214 } 9215 } else 9216 tso = 0; 9217 KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET, 9218 ("%s: len > IP_MAXPACKET", __func__)); 9219 #ifdef DIAGNOSTIC 9220 #ifdef INET6 9221 if (max_linkhdr + hdrlen > MCLBYTES) 9222 #else 9223 if (max_linkhdr + hdrlen > MHLEN) 9224 #endif 9225 panic("tcphdr too big"); 9226 #endif 9227 9228 /* 9229 * This KASSERT is here to catch edge cases at a well defined place. 9230 * Before, those had triggered (random) panic conditions further 9231 * down. 9232 */ 9233 KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__)); 9234 if ((len == 0) && 9235 (flags & TH_FIN) && 9236 (sbused(sb))) { 9237 /* 9238 * We have outstanding data, don't send a fin by itself!. 9239 */ 9240 goto just_return; 9241 } 9242 /* 9243 * Grab a header mbuf, attaching a copy of data to be transmitted, 9244 * and initialize the header from the template for sends on this 9245 * connection. 9246 */ 9247 if (len) { 9248 uint32_t max_val; 9249 uint32_t moff; 9250 9251 if (rack->rc_pace_max_segs) 9252 max_val = rack->rc_pace_max_segs * ctf_fixed_maxseg(tp); 9253 else 9254 max_val = len; 9255 if (rack->r_ctl.rc_pace_max_segs < max_val) 9256 max_val = rack->r_ctl.rc_pace_max_segs; 9257 /* 9258 * We allow a limit on sending with hptsi. 9259 */ 9260 if (len > max_val) { 9261 len = max_val; 9262 } 9263 #ifdef INET6 9264 if (MHLEN < hdrlen + max_linkhdr) 9265 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 9266 else 9267 #endif 9268 m = m_gethdr(M_NOWAIT, MT_DATA); 9269 9270 if (m == NULL) { 9271 SOCKBUF_UNLOCK(sb); 9272 error = ENOBUFS; 9273 sack_rxmit = 0; 9274 goto out; 9275 } 9276 m->m_data += max_linkhdr; 9277 m->m_len = hdrlen; 9278 9279 /* 9280 * Start the m_copy functions from the closest mbuf to the 9281 * sb_offset in the socket buffer chain. 9282 */ 9283 mb = sbsndptr_noadv(sb, sb_offset, &moff); 9284 if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) { 9285 m_copydata(mb, moff, (int)len, 9286 mtod(m, caddr_t)+hdrlen); 9287 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) 9288 sbsndptr_adv(sb, mb, len); 9289 m->m_len += len; 9290 } else { 9291 struct sockbuf *msb; 9292 9293 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) 9294 msb = NULL; 9295 else 9296 msb = sb; 9297 m->m_next = tcp_m_copym( 9298 #ifdef NETFLIX_COPY_ARGS 9299 tp, 9300 #endif 9301 mb, moff, &len, 9302 if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb, 9303 ((rsm == NULL) ? hw_tls : 0) 9304 #ifdef NETFLIX_COPY_ARGS 9305 , &filled_all 9306 #endif 9307 ); 9308 if (len <= (tp->t_maxseg - optlen)) { 9309 /* 9310 * Must have ran out of mbufs for the copy 9311 * shorten it to no longer need tso. Lets 9312 * not put on sendalot since we are low on 9313 * mbufs. 9314 */ 9315 tso = 0; 9316 } 9317 if (m->m_next == NULL) { 9318 SOCKBUF_UNLOCK(sb); 9319 (void)m_free(m); 9320 error = ENOBUFS; 9321 sack_rxmit = 0; 9322 goto out; 9323 } 9324 } 9325 if ((tp->t_flags & TF_FORCEDATA) && len == 1) { 9326 KMOD_TCPSTAT_INC(tcps_sndprobe); 9327 #ifdef STATS 9328 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) 9329 stats_voi_update_abs_u32(tp->t_stats, 9330 VOI_TCP_RETXPB, len); 9331 else 9332 stats_voi_update_abs_u64(tp->t_stats, 9333 VOI_TCP_TXPB, len); 9334 #endif 9335 } else if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) { 9336 if (rsm && (rsm->r_flags & RACK_TLP)) { 9337 /* 9338 * TLP should not count in retran count, but 9339 * in its own bin 9340 */ 9341 counter_u64_add(rack_tlp_retran, 1); 9342 counter_u64_add(rack_tlp_retran_bytes, len); 9343 } else { 9344 tp->t_sndrexmitpack++; 9345 KMOD_TCPSTAT_INC(tcps_sndrexmitpack); 9346 KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len); 9347 } 9348 #ifdef STATS 9349 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB, 9350 len); 9351 #endif 9352 } else { 9353 KMOD_TCPSTAT_INC(tcps_sndpack); 9354 KMOD_TCPSTAT_ADD(tcps_sndbyte, len); 9355 #ifdef STATS 9356 stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB, 9357 len); 9358 #endif 9359 } 9360 /* 9361 * If we're sending everything we've got, set PUSH. (This 9362 * will keep happy those implementations which only give 9363 * data to the user when a buffer fills or a PUSH comes in.) 9364 */ 9365 if (sb_offset + len == sbused(sb) && 9366 sbused(sb) && 9367 !(flags & TH_SYN)) 9368 flags |= TH_PUSH; 9369 9370 /* 9371 * Are we doing pacing, if so we must calculate the slot. We 9372 * only do hptsi in ESTABLISHED and with no RESET being 9373 * sent where we have data to send. 9374 */ 9375 if (((tp->t_state == TCPS_ESTABLISHED) || 9376 (tp->t_state == TCPS_CLOSE_WAIT) || 9377 ((tp->t_state == TCPS_FIN_WAIT_1) && 9378 ((tp->t_flags & TF_SENTFIN) == 0) && 9379 ((flags & TH_FIN) == 0))) && 9380 ((flags & TH_RST) == 0)) { 9381 /* Get our pacing rate */ 9382 tot_len_this_send += len; 9383 slot = rack_get_pacing_delay(rack, tp, tot_len_this_send); 9384 } 9385 SOCKBUF_UNLOCK(sb); 9386 } else { 9387 SOCKBUF_UNLOCK(sb); 9388 if (tp->t_flags & TF_ACKNOW) 9389 KMOD_TCPSTAT_INC(tcps_sndacks); 9390 else if (flags & (TH_SYN | TH_FIN | TH_RST)) 9391 KMOD_TCPSTAT_INC(tcps_sndctrl); 9392 else if (SEQ_GT(tp->snd_up, tp->snd_una)) 9393 KMOD_TCPSTAT_INC(tcps_sndurg); 9394 else 9395 KMOD_TCPSTAT_INC(tcps_sndwinup); 9396 9397 m = m_gethdr(M_NOWAIT, MT_DATA); 9398 if (m == NULL) { 9399 error = ENOBUFS; 9400 sack_rxmit = 0; 9401 goto out; 9402 } 9403 #ifdef INET6 9404 if (isipv6 && (MHLEN < hdrlen + max_linkhdr) && 9405 MHLEN >= hdrlen) { 9406 M_ALIGN(m, hdrlen); 9407 } else 9408 #endif 9409 m->m_data += max_linkhdr; 9410 m->m_len = hdrlen; 9411 } 9412 SOCKBUF_UNLOCK_ASSERT(sb); 9413 m->m_pkthdr.rcvif = (struct ifnet *)0; 9414 #ifdef MAC 9415 mac_inpcb_create_mbuf(inp, m); 9416 #endif 9417 #ifdef INET6 9418 if (isipv6) { 9419 ip6 = mtod(m, struct ip6_hdr *); 9420 #ifdef NETFLIX_TCPOUDP 9421 if (tp->t_port) { 9422 udp = (struct udphdr *)((caddr_t)ip6 + ipoptlen + sizeof(struct ip6_hdr)); 9423 udp->uh_sport = htons(V_tcp_udp_tunneling_port); 9424 udp->uh_dport = tp->t_port; 9425 ulen = hdrlen + len - sizeof(struct ip6_hdr); 9426 udp->uh_ulen = htons(ulen); 9427 th = (struct tcphdr *)(udp + 1); 9428 } else 9429 #endif 9430 th = (struct tcphdr *)(ip6 + 1); 9431 tcpip_fillheaders(inp, 9432 #ifdef NETFLIX_TCPOUDP 9433 tp->t_port, 9434 #endif 9435 ip6, th); 9436 } else 9437 #endif /* INET6 */ 9438 { 9439 ip = mtod(m, struct ip *); 9440 #ifdef TCPDEBUG 9441 ipov = (struct ipovly *)ip; 9442 #endif 9443 #ifdef NETFLIX_TCPOUDP 9444 if (tp->t_port) { 9445 udp = (struct udphdr *)((caddr_t)ip + ipoptlen + sizeof(struct ip)); 9446 udp->uh_sport = htons(V_tcp_udp_tunneling_port); 9447 udp->uh_dport = tp->t_port; 9448 ulen = hdrlen + len - sizeof(struct ip); 9449 udp->uh_ulen = htons(ulen); 9450 th = (struct tcphdr *)(udp + 1); 9451 } else 9452 #endif 9453 th = (struct tcphdr *)(ip + 1); 9454 tcpip_fillheaders(inp, 9455 #ifdef NETFLIX_TCPOUDP 9456 tp->t_port, 9457 #endif 9458 ip, th); 9459 } 9460 /* 9461 * Fill in fields, remembering maximum advertised window for use in 9462 * delaying messages about window sizes. If resending a FIN, be sure 9463 * not to use a new sequence number. 9464 */ 9465 if (flags & TH_FIN && tp->t_flags & TF_SENTFIN && 9466 tp->snd_nxt == tp->snd_max) 9467 tp->snd_nxt--; 9468 /* 9469 * If we are starting a connection, send ECN setup SYN packet. If we 9470 * are on a retransmit, we may resend those bits a number of times 9471 * as per RFC 3168. 9472 */ 9473 if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn == 1) { 9474 if (tp->t_rxtshift >= 1) { 9475 if (tp->t_rxtshift <= V_tcp_ecn_maxretries) 9476 flags |= TH_ECE | TH_CWR; 9477 } else 9478 flags |= TH_ECE | TH_CWR; 9479 } 9480 if (tp->t_state == TCPS_ESTABLISHED && 9481 (tp->t_flags2 & TF2_ECN_PERMIT)) { 9482 /* 9483 * If the peer has ECN, mark data packets with ECN capable 9484 * transmission (ECT). Ignore pure ack packets, 9485 * retransmissions and window probes. 9486 */ 9487 if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) && 9488 (sack_rxmit == 0) && 9489 !((tp->t_flags & TF_FORCEDATA) && len == 1)) { 9490 #ifdef INET6 9491 if (isipv6) 9492 ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20); 9493 else 9494 #endif 9495 ip->ip_tos |= IPTOS_ECN_ECT0; 9496 KMOD_TCPSTAT_INC(tcps_ecn_ect0); 9497 } 9498 /* 9499 * Reply with proper ECN notifications. 9500 */ 9501 if (tp->t_flags2 & TF2_ECN_SND_CWR) { 9502 flags |= TH_CWR; 9503 tp->t_flags2 &= ~TF2_ECN_SND_CWR; 9504 } 9505 if (tp->t_flags2 & TF2_ECN_SND_ECE) 9506 flags |= TH_ECE; 9507 } 9508 /* 9509 * If we are doing retransmissions, then snd_nxt will not reflect 9510 * the first unsent octet. For ACK only packets, we do not want the 9511 * sequence number of the retransmitted packet, we want the sequence 9512 * number of the next unsent octet. So, if there is no data (and no 9513 * SYN or FIN), use snd_max instead of snd_nxt when filling in 9514 * ti_seq. But if we are in persist state, snd_max might reflect 9515 * one byte beyond the right edge of the window, so use snd_nxt in 9516 * that case, since we know we aren't doing a retransmission. 9517 * (retransmit and persist are mutually exclusive...) 9518 */ 9519 if (sack_rxmit == 0) { 9520 if (len || (flags & (TH_SYN | TH_FIN)) || 9521 rack->rc_in_persist) { 9522 th->th_seq = htonl(tp->snd_nxt); 9523 rack_seq = tp->snd_nxt; 9524 } else if (flags & TH_RST) { 9525 /* 9526 * For a Reset send the last cum ack in sequence 9527 * (this like any other choice may still generate a 9528 * challenge ack, if a ack-update packet is in 9529 * flight). 9530 */ 9531 th->th_seq = htonl(tp->snd_una); 9532 rack_seq = tp->snd_una; 9533 } else { 9534 th->th_seq = htonl(tp->snd_max); 9535 rack_seq = tp->snd_max; 9536 } 9537 } else { 9538 th->th_seq = htonl(rsm->r_start); 9539 rack_seq = rsm->r_start; 9540 } 9541 th->th_ack = htonl(tp->rcv_nxt); 9542 if (optlen) { 9543 bcopy(opt, th + 1, optlen); 9544 th->th_off = (sizeof(struct tcphdr) + optlen) >> 2; 9545 } 9546 th->th_flags = flags; 9547 /* 9548 * Calculate receive window. Don't shrink window, but avoid silly 9549 * window syndrome. 9550 * If a RST segment is sent, advertise a window of zero. 9551 */ 9552 if (flags & TH_RST) { 9553 recwin = 0; 9554 } else { 9555 if (recwin < (long)(so->so_rcv.sb_hiwat / 4) && 9556 recwin < (long)ctf_fixed_maxseg(tp)) 9557 recwin = 0; 9558 if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) && 9559 recwin < (long)(tp->rcv_adv - tp->rcv_nxt)) 9560 recwin = (long)(tp->rcv_adv - tp->rcv_nxt); 9561 if (recwin > (long)TCP_MAXWIN << tp->rcv_scale) 9562 recwin = (long)TCP_MAXWIN << tp->rcv_scale; 9563 } 9564 9565 /* 9566 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or 9567 * <SYN,ACK>) segment itself is never scaled. The <SYN,ACK> case is 9568 * handled in syncache. 9569 */ 9570 if (flags & TH_SYN) 9571 th->th_win = htons((u_short) 9572 (min(sbspace(&so->so_rcv), TCP_MAXWIN))); 9573 else 9574 th->th_win = htons((u_short)(recwin >> tp->rcv_scale)); 9575 /* 9576 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0 9577 * window. This may cause the remote transmitter to stall. This 9578 * flag tells soreceive() to disable delayed acknowledgements when 9579 * draining the buffer. This can occur if the receiver is 9580 * attempting to read more data than can be buffered prior to 9581 * transmitting on the connection. 9582 */ 9583 if (th->th_win == 0) { 9584 tp->t_sndzerowin++; 9585 tp->t_flags |= TF_RXWIN0SENT; 9586 } else 9587 tp->t_flags &= ~TF_RXWIN0SENT; 9588 if (SEQ_GT(tp->snd_up, tp->snd_nxt)) { 9589 th->th_urp = htons((u_short)(tp->snd_up - tp->snd_nxt)); 9590 th->th_flags |= TH_URG; 9591 } else 9592 /* 9593 * If no urgent pointer to send, then we pull the urgent 9594 * pointer to the left edge of the send window so that it 9595 * doesn't drift into the send window on sequence number 9596 * wraparound. 9597 */ 9598 tp->snd_up = tp->snd_una; /* drag it along */ 9599 9600 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 9601 if (to.to_flags & TOF_SIGNATURE) { 9602 /* 9603 * Calculate MD5 signature and put it into the place 9604 * determined before. 9605 * NOTE: since TCP options buffer doesn't point into 9606 * mbuf's data, calculate offset and use it. 9607 */ 9608 if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th, 9609 (u_char *)(th + 1) + (to.to_signature - opt)) != 0) { 9610 /* 9611 * Do not send segment if the calculation of MD5 9612 * digest has failed. 9613 */ 9614 goto out; 9615 } 9616 } 9617 #endif 9618 9619 /* 9620 * Put TCP length in extended header, and then checksum extended 9621 * header and data. 9622 */ 9623 m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */ 9624 #ifdef INET6 9625 if (isipv6) { 9626 /* 9627 * ip6_plen is not need to be filled now, and will be filled 9628 * in ip6_output. 9629 */ 9630 if (tp->t_port) { 9631 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 9632 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 9633 udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 9634 th->th_sum = htons(0); 9635 UDPSTAT_INC(udps_opackets); 9636 } else { 9637 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 9638 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 9639 th->th_sum = in6_cksum_pseudo(ip6, 9640 sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP, 9641 0); 9642 } 9643 } 9644 #endif 9645 #if defined(INET6) && defined(INET) 9646 else 9647 #endif 9648 #ifdef INET 9649 { 9650 if (tp->t_port) { 9651 m->m_pkthdr.csum_flags = CSUM_UDP; 9652 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 9653 udp->uh_sum = in_pseudo(ip->ip_src.s_addr, 9654 ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP)); 9655 th->th_sum = htons(0); 9656 UDPSTAT_INC(udps_opackets); 9657 } else { 9658 m->m_pkthdr.csum_flags = CSUM_TCP; 9659 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 9660 th->th_sum = in_pseudo(ip->ip_src.s_addr, 9661 ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) + 9662 IPPROTO_TCP + len + optlen)); 9663 } 9664 /* IP version must be set here for ipv4/ipv6 checking later */ 9665 KASSERT(ip->ip_v == IPVERSION, 9666 ("%s: IP version incorrect: %d", __func__, ip->ip_v)); 9667 } 9668 #endif 9669 /* 9670 * Enable TSO and specify the size of the segments. The TCP pseudo 9671 * header checksum is always provided. XXX: Fixme: This is currently 9672 * not the case for IPv6. 9673 */ 9674 if (tso || force_tso) { 9675 KASSERT(force_tso || len > tp->t_maxseg - optlen, 9676 ("%s: len <= tso_segsz", __func__)); 9677 m->m_pkthdr.csum_flags |= CSUM_TSO; 9678 m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen; 9679 } 9680 KASSERT(len + hdrlen == m_length(m, NULL), 9681 ("%s: mbuf chain different than expected: %d + %u != %u", 9682 __func__, len, hdrlen, m_length(m, NULL))); 9683 9684 #ifdef TCP_HHOOK 9685 /* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */ 9686 hhook_run_tcp_est_out(tp, th, &to, len, tso); 9687 #endif 9688 #ifdef TCPDEBUG 9689 /* 9690 * Trace. 9691 */ 9692 if (so->so_options & SO_DEBUG) { 9693 u_short save = 0; 9694 9695 #ifdef INET6 9696 if (!isipv6) 9697 #endif 9698 { 9699 save = ipov->ih_len; 9700 ipov->ih_len = htons(m->m_pkthdr.len /* - hdrlen + 9701 * (th->th_off << 2) */ ); 9702 } 9703 tcp_trace(TA_OUTPUT, tp->t_state, tp, mtod(m, void *), th, 0); 9704 #ifdef INET6 9705 if (!isipv6) 9706 #endif 9707 ipov->ih_len = save; 9708 } 9709 #endif /* TCPDEBUG */ 9710 9711 /* We're getting ready to send; log now. */ 9712 if (tp->t_logstate != TCP_LOG_STATE_OFF) { 9713 union tcp_log_stackspecific log; 9714 struct timeval tv; 9715 9716 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 9717 log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts; 9718 log.u_bbr.ininput = rack->rc_inp->inp_in_input; 9719 log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt; 9720 log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs; 9721 log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs; 9722 log.u_bbr.flex4 = orig_len; 9723 if (filled_all) 9724 log.u_bbr.flex5 = 0x80000000; 9725 else 9726 log.u_bbr.flex5 = 0; 9727 if (rsm || sack_rxmit) { 9728 log.u_bbr.flex8 = 1; 9729 } else { 9730 log.u_bbr.flex8 = 0; 9731 } 9732 log.u_bbr.pkts_out = tp->t_maxseg; 9733 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 9734 log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked); 9735 lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK, 9736 len, &log, false, NULL, NULL, 0, &tv); 9737 } else 9738 lgb = NULL; 9739 9740 /* 9741 * Fill in IP length and desired time to live and send to IP level. 9742 * There should be a better way to handle ttl and tos; we could keep 9743 * them in the template, but need a way to checksum without them. 9744 */ 9745 /* 9746 * m->m_pkthdr.len should have been set before cksum calcuration, 9747 * because in6_cksum() need it. 9748 */ 9749 #ifdef INET6 9750 if (isipv6) { 9751 /* 9752 * we separately set hoplimit for every segment, since the 9753 * user might want to change the value via setsockopt. Also, 9754 * desired default hop limit might be changed via Neighbor 9755 * Discovery. 9756 */ 9757 ip6->ip6_hlim = in6_selecthlim(inp, NULL); 9758 9759 /* 9760 * Set the packet size here for the benefit of DTrace 9761 * probes. ip6_output() will set it properly; it's supposed 9762 * to include the option header lengths as well. 9763 */ 9764 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6)); 9765 9766 if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) 9767 tp->t_flags2 |= TF2_PLPMTU_PMTUD; 9768 else 9769 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD; 9770 9771 if (tp->t_state == TCPS_SYN_SENT) 9772 TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th); 9773 9774 TCP_PROBE5(send, NULL, tp, ip6, tp, th); 9775 /* TODO: IPv6 IP6TOS_ECT bit on */ 9776 error = ip6_output(m, tp->t_inpcb->in6p_outputopts, 9777 &inp->inp_route6, 9778 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0), 9779 NULL, NULL, inp); 9780 9781 if (error == EMSGSIZE && inp->inp_route6.ro_rt != NULL) 9782 mtu = inp->inp_route6.ro_rt->rt_mtu; 9783 } 9784 #endif /* INET6 */ 9785 #if defined(INET) && defined(INET6) 9786 else 9787 #endif 9788 #ifdef INET 9789 { 9790 ip->ip_len = htons(m->m_pkthdr.len); 9791 #ifdef INET6 9792 if (inp->inp_vflag & INP_IPV6PROTO) 9793 ip->ip_ttl = in6_selecthlim(inp, NULL); 9794 #endif /* INET6 */ 9795 /* 9796 * If we do path MTU discovery, then we set DF on every 9797 * packet. This might not be the best thing to do according 9798 * to RFC3390 Section 2. However the tcp hostcache migitates 9799 * the problem so it affects only the first tcp connection 9800 * with a host. 9801 * 9802 * NB: Don't set DF on small MTU/MSS to have a safe 9803 * fallback. 9804 */ 9805 if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) { 9806 tp->t_flags2 |= TF2_PLPMTU_PMTUD; 9807 if (tp->t_port == 0 || len < V_tcp_minmss) { 9808 ip->ip_off |= htons(IP_DF); 9809 } 9810 } else { 9811 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD; 9812 } 9813 9814 if (tp->t_state == TCPS_SYN_SENT) 9815 TCP_PROBE5(connect__request, NULL, tp, ip, tp, th); 9816 9817 TCP_PROBE5(send, NULL, tp, ip, tp, th); 9818 9819 error = ip_output(m, tp->t_inpcb->inp_options, &inp->inp_route, 9820 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0), 0, 9821 inp); 9822 if (error == EMSGSIZE && inp->inp_route.ro_rt != NULL) 9823 mtu = inp->inp_route.ro_rt->rt_mtu; 9824 } 9825 #endif /* INET */ 9826 9827 out: 9828 if (lgb) { 9829 lgb->tlb_errno = error; 9830 lgb = NULL; 9831 } 9832 /* 9833 * In transmit state, time the transmission and arrange for the 9834 * retransmit. In persist state, just set snd_max. 9835 */ 9836 if (error == 0) { 9837 if (TCPS_HAVEESTABLISHED(tp->t_state) && 9838 (tp->t_flags & TF_SACK_PERMIT) && 9839 tp->rcv_numsacks > 0) 9840 tcp_clean_dsack_blocks(tp); 9841 if (len == 0) 9842 counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1); 9843 else if (len == 1) { 9844 counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1); 9845 } else if (len > 1) { 9846 int idx; 9847 9848 idx = (len / ctf_fixed_maxseg(tp)) + 3; 9849 if (idx >= TCP_MSS_ACCT_ATIMER) 9850 counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1); 9851 else 9852 counter_u64_add(rack_out_size[idx], 1); 9853 } 9854 if (hw_tls && len > 0) { 9855 if (filled_all) { 9856 counter_u64_add(rack_tls_filled, 1); 9857 rack_log_type_hrdwtso(tp, rack, len, 0, orig_len, 1); 9858 } else { 9859 if (rsm) { 9860 counter_u64_add(rack_tls_rxt, 1); 9861 rack_log_type_hrdwtso(tp, rack, len, 2, orig_len, 1); 9862 } else if (doing_tlp) { 9863 counter_u64_add(rack_tls_tlp, 1); 9864 rack_log_type_hrdwtso(tp, rack, len, 3, orig_len, 1); 9865 } else if ( (ctf_outstanding(tp) + rack->r_ctl.rc_pace_min_segs) > sbavail(sb)) { 9866 counter_u64_add(rack_tls_app, 1); 9867 rack_log_type_hrdwtso(tp, rack, len, 4, orig_len, 1); 9868 } else if ((ctf_flight_size(tp, rack->r_ctl.rc_sacked) + rack->r_ctl.rc_pace_min_segs) > tp->snd_cwnd) { 9869 counter_u64_add(rack_tls_cwnd, 1); 9870 rack_log_type_hrdwtso(tp, rack, len, 5, orig_len, 1); 9871 } else if ((ctf_outstanding(tp) + rack->r_ctl.rc_pace_min_segs) > tp->snd_wnd) { 9872 counter_u64_add(rack_tls_rwnd, 1); 9873 rack_log_type_hrdwtso(tp, rack, len, 6, orig_len, 1); 9874 } else { 9875 rack_log_type_hrdwtso(tp, rack, len, 7, orig_len, 1); 9876 counter_u64_add(rack_tls_other, 1); 9877 } 9878 } 9879 } 9880 } 9881 if (sub_from_prr && (error == 0)) { 9882 if (rack->r_ctl.rc_prr_sndcnt >= len) 9883 rack->r_ctl.rc_prr_sndcnt -= len; 9884 else 9885 rack->r_ctl.rc_prr_sndcnt = 0; 9886 } 9887 sub_from_prr = 0; 9888 rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error, cts, 9889 pass, rsm); 9890 if ((error == 0) && 9891 (len > 0) && 9892 (tp->snd_una == tp->snd_max)) 9893 rack->r_ctl.rc_tlp_rxt_last_time = cts; 9894 if ((tp->t_flags & TF_FORCEDATA) == 0 || 9895 (rack->rc_in_persist == 0)) { 9896 tcp_seq startseq = tp->snd_nxt; 9897 9898 /* 9899 * Advance snd_nxt over sequence space of this segment. 9900 */ 9901 if (error) 9902 /* We don't log or do anything with errors */ 9903 goto nomore; 9904 9905 if (flags & (TH_SYN | TH_FIN)) { 9906 if (flags & TH_SYN) 9907 tp->snd_nxt++; 9908 if (flags & TH_FIN) { 9909 tp->snd_nxt++; 9910 tp->t_flags |= TF_SENTFIN; 9911 } 9912 } 9913 /* In the ENOBUFS case we do *not* update snd_max */ 9914 if (sack_rxmit) 9915 goto nomore; 9916 9917 tp->snd_nxt += len; 9918 if (SEQ_GT(tp->snd_nxt, tp->snd_max)) { 9919 if (tp->snd_una == tp->snd_max) { 9920 /* 9921 * Update the time we just added data since 9922 * none was outstanding. 9923 */ 9924 rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__); 9925 tp->t_acktime = ticks; 9926 } 9927 tp->snd_max = tp->snd_nxt; 9928 /* 9929 * Time this transmission if not a retransmission and 9930 * not currently timing anything. 9931 * This is only relevant in case of switching back to 9932 * the base stack. 9933 */ 9934 if (tp->t_rtttime == 0) { 9935 tp->t_rtttime = ticks; 9936 tp->t_rtseq = startseq; 9937 KMOD_TCPSTAT_INC(tcps_segstimed); 9938 } 9939 #ifdef STATS 9940 if (!(tp->t_flags & TF_GPUTINPROG) && len) { 9941 tp->t_flags |= TF_GPUTINPROG; 9942 tp->gput_seq = startseq; 9943 tp->gput_ack = startseq + 9944 ulmin(sbavail(sb) - sb_offset, sendwin); 9945 tp->gput_ts = tcp_ts_getticks(); 9946 } 9947 #endif 9948 } 9949 } else { 9950 /* 9951 * Persist case, update snd_max but since we are in persist 9952 * mode (no window) we do not update snd_nxt. 9953 */ 9954 int32_t xlen = len; 9955 9956 if (error) 9957 goto nomore; 9958 9959 if (flags & TH_SYN) 9960 ++xlen; 9961 if (flags & TH_FIN) { 9962 ++xlen; 9963 tp->t_flags |= TF_SENTFIN; 9964 } 9965 /* In the ENOBUFS case we do *not* update snd_max */ 9966 if (SEQ_GT(tp->snd_nxt + xlen, tp->snd_max)) { 9967 if (tp->snd_una == tp->snd_max) { 9968 /* 9969 * Update the time we just added data since 9970 * none was outstanding. 9971 */ 9972 rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__); 9973 tp->t_acktime = ticks; 9974 } 9975 tp->snd_max = tp->snd_nxt + len; 9976 } 9977 } 9978 nomore: 9979 if (error) { 9980 SOCKBUF_UNLOCK_ASSERT(sb); /* Check gotos. */ 9981 /* 9982 * Failures do not advance the seq counter above. For the 9983 * case of ENOBUFS we will fall out and retry in 1ms with 9984 * the hpts. Everything else will just have to retransmit 9985 * with the timer. 9986 * 9987 * In any case, we do not want to loop around for another 9988 * send without a good reason. 9989 */ 9990 sendalot = 0; 9991 switch (error) { 9992 case EPERM: 9993 tp->t_flags &= ~TF_FORCEDATA; 9994 tp->t_softerror = error; 9995 return (error); 9996 case ENOBUFS: 9997 if (slot == 0) { 9998 /* 9999 * Pace us right away to retry in a some 10000 * time 10001 */ 10002 slot = 1 + rack->rc_enobuf; 10003 if (rack->rc_enobuf < 255) 10004 rack->rc_enobuf++; 10005 if (slot > (rack->rc_rack_rtt / 2)) { 10006 slot = rack->rc_rack_rtt / 2; 10007 } 10008 if (slot < 10) 10009 slot = 10; 10010 } 10011 counter_u64_add(rack_saw_enobuf, 1); 10012 error = 0; 10013 goto enobufs; 10014 case EMSGSIZE: 10015 /* 10016 * For some reason the interface we used initially 10017 * to send segments changed to another or lowered 10018 * its MTU. If TSO was active we either got an 10019 * interface without TSO capabilits or TSO was 10020 * turned off. If we obtained mtu from ip_output() 10021 * then update it and try again. 10022 */ 10023 if (tso) 10024 tp->t_flags &= ~TF_TSO; 10025 if (mtu != 0) { 10026 tcp_mss_update(tp, -1, mtu, NULL, NULL); 10027 goto again; 10028 } 10029 slot = 10; 10030 rack_start_hpts_timer(rack, tp, cts, slot, 0, 0); 10031 tp->t_flags &= ~TF_FORCEDATA; 10032 return (error); 10033 case ENETUNREACH: 10034 counter_u64_add(rack_saw_enetunreach, 1); 10035 case EHOSTDOWN: 10036 case EHOSTUNREACH: 10037 case ENETDOWN: 10038 if (TCPS_HAVERCVDSYN(tp->t_state)) { 10039 tp->t_softerror = error; 10040 } 10041 /* FALLTHROUGH */ 10042 default: 10043 slot = 10; 10044 rack_start_hpts_timer(rack, tp, cts, slot, 0, 0); 10045 tp->t_flags &= ~TF_FORCEDATA; 10046 return (error); 10047 } 10048 } else { 10049 rack->rc_enobuf = 0; 10050 } 10051 KMOD_TCPSTAT_INC(tcps_sndtotal); 10052 10053 /* 10054 * Data sent (as far as we can tell). If this advertises a larger 10055 * window than any other segment, then remember the size of the 10056 * advertised window. Any pending ACK has now been sent. 10057 */ 10058 if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv)) 10059 tp->rcv_adv = tp->rcv_nxt + recwin; 10060 tp->last_ack_sent = tp->rcv_nxt; 10061 tp->t_flags &= ~(TF_ACKNOW | TF_DELACK); 10062 enobufs: 10063 rack->r_tlp_running = 0; 10064 if (flags & TH_RST) { 10065 /* 10066 * We don't send again after sending a RST. 10067 */ 10068 slot = 0; 10069 sendalot = 0; 10070 } 10071 if (rsm && (slot == 0)) { 10072 /* 10073 * Dup ack retransmission possibly, so 10074 * lets assure we have at least min rack 10075 * time, if its a rack resend then the rack 10076 * to will also be set to this. 10077 */ 10078 slot = rack->r_ctl.rc_min_to; 10079 } 10080 if (slot) { 10081 /* set the rack tcb into the slot N */ 10082 counter_u64_add(rack_paced_segments, 1); 10083 } else if (sendalot) { 10084 if (len) 10085 counter_u64_add(rack_unpaced_segments, 1); 10086 sack_rxmit = 0; 10087 tp->t_flags &= ~TF_FORCEDATA; 10088 goto again; 10089 } else if (len) { 10090 counter_u64_add(rack_unpaced_segments, 1); 10091 } 10092 tp->t_flags &= ~TF_FORCEDATA; 10093 rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0); 10094 return (error); 10095 } 10096 10097 /* 10098 * rack_ctloutput() must drop the inpcb lock before performing copyin on 10099 * socket option arguments. When it re-acquires the lock after the copy, it 10100 * has to revalidate that the connection is still valid for the socket 10101 * option. 10102 */ 10103 static int 10104 rack_set_sockopt(struct socket *so, struct sockopt *sopt, 10105 struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack) 10106 { 10107 struct epoch_tracker et; 10108 int32_t error = 0, optval; 10109 10110 switch (sopt->sopt_name) { 10111 case TCP_RACK_PROP_RATE: 10112 case TCP_RACK_PROP: 10113 case TCP_RACK_TLP_REDUCE: 10114 case TCP_RACK_EARLY_RECOV: 10115 case TCP_RACK_PACE_ALWAYS: 10116 case TCP_DELACK: 10117 case TCP_RACK_PACE_REDUCE: 10118 case TCP_RACK_PACE_MAX_SEG: 10119 case TCP_RACK_PRR_SENDALOT: 10120 case TCP_RACK_MIN_TO: 10121 case TCP_RACK_EARLY_SEG: 10122 case TCP_RACK_REORD_THRESH: 10123 case TCP_RACK_REORD_FADE: 10124 case TCP_RACK_TLP_THRESH: 10125 case TCP_RACK_PKT_DELAY: 10126 case TCP_RACK_TLP_USE: 10127 case TCP_RACK_TLP_INC_VAR: 10128 case TCP_RACK_IDLE_REDUCE_HIGH: 10129 case TCP_RACK_MIN_PACE: 10130 case TCP_RACK_GP_INCREASE: 10131 case TCP_BBR_RACK_RTT_USE: 10132 case TCP_BBR_USE_RACK_CHEAT: 10133 case TCP_RACK_DO_DETECTION: 10134 case TCP_DATA_AFTER_CLOSE: 10135 break; 10136 default: 10137 return (tcp_default_ctloutput(so, sopt, inp, tp)); 10138 break; 10139 } 10140 INP_WUNLOCK(inp); 10141 error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval)); 10142 if (error) 10143 return (error); 10144 INP_WLOCK(inp); 10145 if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) { 10146 INP_WUNLOCK(inp); 10147 return (ECONNRESET); 10148 } 10149 tp = intotcpcb(inp); 10150 rack = (struct tcp_rack *)tp->t_fb_ptr; 10151 switch (sopt->sopt_name) { 10152 case TCP_RACK_DO_DETECTION: 10153 RACK_OPTS_INC(tcp_rack_do_detection); 10154 if (optval == 0) 10155 rack->do_detection = 0; 10156 else 10157 rack->do_detection = 1; 10158 break; 10159 case TCP_RACK_PROP_RATE: 10160 if ((optval <= 0) || (optval >= 100)) { 10161 error = EINVAL; 10162 break; 10163 } 10164 RACK_OPTS_INC(tcp_rack_prop_rate); 10165 rack->r_ctl.rc_prop_rate = optval; 10166 break; 10167 case TCP_RACK_TLP_USE: 10168 if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) { 10169 error = EINVAL; 10170 break; 10171 } 10172 RACK_OPTS_INC(tcp_tlp_use); 10173 rack->rack_tlp_threshold_use = optval; 10174 break; 10175 case TCP_RACK_PROP: 10176 /* RACK proportional rate reduction (bool) */ 10177 RACK_OPTS_INC(tcp_rack_prop); 10178 rack->r_ctl.rc_prop_reduce = optval; 10179 break; 10180 case TCP_RACK_TLP_REDUCE: 10181 /* RACK TLP cwnd reduction (bool) */ 10182 RACK_OPTS_INC(tcp_rack_tlp_reduce); 10183 rack->r_ctl.rc_tlp_cwnd_reduce = optval; 10184 break; 10185 case TCP_RACK_EARLY_RECOV: 10186 /* Should recovery happen early (bool) */ 10187 RACK_OPTS_INC(tcp_rack_early_recov); 10188 rack->r_ctl.rc_early_recovery = optval; 10189 break; 10190 case TCP_RACK_PACE_ALWAYS: 10191 /* Use the always pace method (bool) */ 10192 RACK_OPTS_INC(tcp_rack_pace_always); 10193 if (optval > 0) 10194 rack->rc_always_pace = 1; 10195 else 10196 rack->rc_always_pace = 0; 10197 break; 10198 case TCP_RACK_PACE_REDUCE: 10199 /* RACK Hptsi reduction factor (divisor) */ 10200 RACK_OPTS_INC(tcp_rack_pace_reduce); 10201 if (optval) 10202 /* Must be non-zero */ 10203 rack->rc_pace_reduce = optval; 10204 else 10205 error = EINVAL; 10206 break; 10207 case TCP_RACK_PACE_MAX_SEG: 10208 /* Max segments in a pace */ 10209 RACK_OPTS_INC(tcp_rack_max_seg); 10210 rack->rc_pace_max_segs = optval; 10211 rack_set_pace_segments(tp, rack); 10212 break; 10213 case TCP_RACK_PRR_SENDALOT: 10214 /* Allow PRR to send more than one seg */ 10215 RACK_OPTS_INC(tcp_rack_prr_sendalot); 10216 rack->r_ctl.rc_prr_sendalot = optval; 10217 break; 10218 case TCP_RACK_MIN_TO: 10219 /* Minimum time between rack t-o's in ms */ 10220 RACK_OPTS_INC(tcp_rack_min_to); 10221 rack->r_ctl.rc_min_to = optval; 10222 break; 10223 case TCP_RACK_EARLY_SEG: 10224 /* If early recovery max segments */ 10225 RACK_OPTS_INC(tcp_rack_early_seg); 10226 rack->r_ctl.rc_early_recovery_segs = optval; 10227 break; 10228 case TCP_RACK_REORD_THRESH: 10229 /* RACK reorder threshold (shift amount) */ 10230 RACK_OPTS_INC(tcp_rack_reord_thresh); 10231 if ((optval > 0) && (optval < 31)) 10232 rack->r_ctl.rc_reorder_shift = optval; 10233 else 10234 error = EINVAL; 10235 break; 10236 case TCP_RACK_REORD_FADE: 10237 /* Does reordering fade after ms time */ 10238 RACK_OPTS_INC(tcp_rack_reord_fade); 10239 rack->r_ctl.rc_reorder_fade = optval; 10240 break; 10241 case TCP_RACK_TLP_THRESH: 10242 /* RACK TLP theshold i.e. srtt+(srtt/N) */ 10243 RACK_OPTS_INC(tcp_rack_tlp_thresh); 10244 if (optval) 10245 rack->r_ctl.rc_tlp_threshold = optval; 10246 else 10247 error = EINVAL; 10248 break; 10249 case TCP_BBR_USE_RACK_CHEAT: 10250 RACK_OPTS_INC(tcp_rack_cheat); 10251 if (optval) 10252 rack->use_rack_cheat = 1; 10253 else 10254 rack->use_rack_cheat = 0; 10255 break; 10256 case TCP_RACK_PKT_DELAY: 10257 /* RACK added ms i.e. rack-rtt + reord + N */ 10258 RACK_OPTS_INC(tcp_rack_pkt_delay); 10259 rack->r_ctl.rc_pkt_delay = optval; 10260 break; 10261 case TCP_RACK_TLP_INC_VAR: 10262 /* Does TLP include rtt variance in t-o */ 10263 error = EINVAL; 10264 break; 10265 case TCP_RACK_IDLE_REDUCE_HIGH: 10266 error = EINVAL; 10267 break; 10268 case TCP_DELACK: 10269 if (optval == 0) 10270 tp->t_delayed_ack = 0; 10271 else 10272 tp->t_delayed_ack = 1; 10273 if (tp->t_flags & TF_DELACK) { 10274 tp->t_flags &= ~TF_DELACK; 10275 tp->t_flags |= TF_ACKNOW; 10276 NET_EPOCH_ENTER(et); 10277 rack_output(tp); 10278 NET_EPOCH_EXIT(et); 10279 } 10280 break; 10281 case TCP_RACK_MIN_PACE: 10282 RACK_OPTS_INC(tcp_rack_min_pace); 10283 if (optval > 3) 10284 rack->r_enforce_min_pace = 3; 10285 else 10286 rack->r_enforce_min_pace = optval; 10287 break; 10288 case TCP_RACK_GP_INCREASE: 10289 if ((optval >= 0) && 10290 (optval <= 256)) 10291 rack->rack_per_of_gp = optval; 10292 else 10293 error = EINVAL; 10294 10295 break; 10296 case TCP_BBR_RACK_RTT_USE: 10297 if ((optval != USE_RTT_HIGH) && 10298 (optval != USE_RTT_LOW) && 10299 (optval != USE_RTT_AVG)) 10300 error = EINVAL; 10301 else 10302 rack->r_ctl.rc_rate_sample_method = optval; 10303 break; 10304 case TCP_DATA_AFTER_CLOSE: 10305 if (optval) 10306 rack->rc_allow_data_af_clo = 1; 10307 else 10308 rack->rc_allow_data_af_clo = 0; 10309 break; 10310 default: 10311 return (tcp_default_ctloutput(so, sopt, inp, tp)); 10312 break; 10313 } 10314 #ifdef NETFLIX_STATS 10315 tcp_log_socket_option(tp, sopt->sopt_name, optval, error); 10316 #endif 10317 INP_WUNLOCK(inp); 10318 return (error); 10319 } 10320 10321 static int 10322 rack_get_sockopt(struct socket *so, struct sockopt *sopt, 10323 struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack) 10324 { 10325 int32_t error, optval; 10326 10327 /* 10328 * Because all our options are either boolean or an int, we can just 10329 * pull everything into optval and then unlock and copy. If we ever 10330 * add a option that is not a int, then this will have quite an 10331 * impact to this routine. 10332 */ 10333 error = 0; 10334 switch (sopt->sopt_name) { 10335 case TCP_RACK_DO_DETECTION: 10336 optval = rack->do_detection; 10337 break; 10338 10339 case TCP_RACK_PROP_RATE: 10340 optval = rack->r_ctl.rc_prop_rate; 10341 break; 10342 case TCP_RACK_PROP: 10343 /* RACK proportional rate reduction (bool) */ 10344 optval = rack->r_ctl.rc_prop_reduce; 10345 break; 10346 case TCP_RACK_TLP_REDUCE: 10347 /* RACK TLP cwnd reduction (bool) */ 10348 optval = rack->r_ctl.rc_tlp_cwnd_reduce; 10349 break; 10350 case TCP_RACK_EARLY_RECOV: 10351 /* Should recovery happen early (bool) */ 10352 optval = rack->r_ctl.rc_early_recovery; 10353 break; 10354 case TCP_RACK_PACE_REDUCE: 10355 /* RACK Hptsi reduction factor (divisor) */ 10356 optval = rack->rc_pace_reduce; 10357 break; 10358 case TCP_RACK_PACE_MAX_SEG: 10359 /* Max segments in a pace */ 10360 optval = rack->rc_pace_max_segs; 10361 break; 10362 case TCP_RACK_PACE_ALWAYS: 10363 /* Use the always pace method */ 10364 optval = rack->rc_always_pace; 10365 break; 10366 case TCP_RACK_PRR_SENDALOT: 10367 /* Allow PRR to send more than one seg */ 10368 optval = rack->r_ctl.rc_prr_sendalot; 10369 break; 10370 case TCP_RACK_MIN_TO: 10371 /* Minimum time between rack t-o's in ms */ 10372 optval = rack->r_ctl.rc_min_to; 10373 break; 10374 case TCP_RACK_EARLY_SEG: 10375 /* If early recovery max segments */ 10376 optval = rack->r_ctl.rc_early_recovery_segs; 10377 break; 10378 case TCP_RACK_REORD_THRESH: 10379 /* RACK reorder threshold (shift amount) */ 10380 optval = rack->r_ctl.rc_reorder_shift; 10381 break; 10382 case TCP_RACK_REORD_FADE: 10383 /* Does reordering fade after ms time */ 10384 optval = rack->r_ctl.rc_reorder_fade; 10385 break; 10386 case TCP_BBR_USE_RACK_CHEAT: 10387 /* Do we use the rack cheat for rxt */ 10388 optval = rack->use_rack_cheat; 10389 break; 10390 case TCP_RACK_TLP_THRESH: 10391 /* RACK TLP theshold i.e. srtt+(srtt/N) */ 10392 optval = rack->r_ctl.rc_tlp_threshold; 10393 break; 10394 case TCP_RACK_PKT_DELAY: 10395 /* RACK added ms i.e. rack-rtt + reord + N */ 10396 optval = rack->r_ctl.rc_pkt_delay; 10397 break; 10398 case TCP_RACK_TLP_USE: 10399 optval = rack->rack_tlp_threshold_use; 10400 break; 10401 case TCP_RACK_TLP_INC_VAR: 10402 /* Does TLP include rtt variance in t-o */ 10403 error = EINVAL; 10404 break; 10405 case TCP_RACK_IDLE_REDUCE_HIGH: 10406 error = EINVAL; 10407 break; 10408 case TCP_RACK_MIN_PACE: 10409 optval = rack->r_enforce_min_pace; 10410 break; 10411 case TCP_RACK_GP_INCREASE: 10412 optval = rack->rack_per_of_gp; 10413 break; 10414 case TCP_BBR_RACK_RTT_USE: 10415 optval = rack->r_ctl.rc_rate_sample_method; 10416 break; 10417 case TCP_DELACK: 10418 optval = tp->t_delayed_ack; 10419 break; 10420 case TCP_DATA_AFTER_CLOSE: 10421 optval = rack->rc_allow_data_af_clo; 10422 break; 10423 default: 10424 return (tcp_default_ctloutput(so, sopt, inp, tp)); 10425 break; 10426 } 10427 INP_WUNLOCK(inp); 10428 if (error == 0) { 10429 error = sooptcopyout(sopt, &optval, sizeof optval); 10430 } 10431 return (error); 10432 } 10433 10434 static int 10435 rack_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp) 10436 { 10437 int32_t error = EINVAL; 10438 struct tcp_rack *rack; 10439 10440 rack = (struct tcp_rack *)tp->t_fb_ptr; 10441 if (rack == NULL) { 10442 /* Huh? */ 10443 goto out; 10444 } 10445 if (sopt->sopt_dir == SOPT_SET) { 10446 return (rack_set_sockopt(so, sopt, inp, tp, rack)); 10447 } else if (sopt->sopt_dir == SOPT_GET) { 10448 return (rack_get_sockopt(so, sopt, inp, tp, rack)); 10449 } 10450 out: 10451 INP_WUNLOCK(inp); 10452 return (error); 10453 } 10454 10455 10456 static struct tcp_function_block __tcp_rack = { 10457 .tfb_tcp_block_name = __XSTRING(STACKNAME), 10458 .tfb_tcp_output = rack_output, 10459 .tfb_do_queued_segments = ctf_do_queued_segments, 10460 .tfb_do_segment_nounlock = rack_do_segment_nounlock, 10461 .tfb_tcp_do_segment = rack_do_segment, 10462 .tfb_tcp_ctloutput = rack_ctloutput, 10463 .tfb_tcp_fb_init = rack_init, 10464 .tfb_tcp_fb_fini = rack_fini, 10465 .tfb_tcp_timer_stop_all = rack_stopall, 10466 .tfb_tcp_timer_activate = rack_timer_activate, 10467 .tfb_tcp_timer_active = rack_timer_active, 10468 .tfb_tcp_timer_stop = rack_timer_stop, 10469 .tfb_tcp_rexmit_tmr = rack_remxt_tmr, 10470 .tfb_tcp_handoff_ok = rack_handoff_ok 10471 }; 10472 10473 static const char *rack_stack_names[] = { 10474 __XSTRING(STACKNAME), 10475 #ifdef STACKALIAS 10476 __XSTRING(STACKALIAS), 10477 #endif 10478 }; 10479 10480 static int 10481 rack_ctor(void *mem, int32_t size, void *arg, int32_t how) 10482 { 10483 memset(mem, 0, size); 10484 return (0); 10485 } 10486 10487 static void 10488 rack_dtor(void *mem, int32_t size, void *arg) 10489 { 10490 10491 } 10492 10493 static bool rack_mod_inited = false; 10494 10495 static int 10496 tcp_addrack(module_t mod, int32_t type, void *data) 10497 { 10498 int32_t err = 0; 10499 int num_stacks; 10500 10501 switch (type) { 10502 case MOD_LOAD: 10503 rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map", 10504 sizeof(struct rack_sendmap), 10505 rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0); 10506 10507 rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb", 10508 sizeof(struct tcp_rack), 10509 rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0); 10510 10511 sysctl_ctx_init(&rack_sysctl_ctx); 10512 rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx, 10513 SYSCTL_STATIC_CHILDREN(_net_inet_tcp), 10514 OID_AUTO, 10515 #ifdef STACKALIAS 10516 __XSTRING(STACKALIAS), 10517 #else 10518 __XSTRING(STACKNAME), 10519 #endif 10520 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 10521 ""); 10522 if (rack_sysctl_root == NULL) { 10523 printf("Failed to add sysctl node\n"); 10524 err = EFAULT; 10525 goto free_uma; 10526 } 10527 rack_init_sysctls(); 10528 num_stacks = nitems(rack_stack_names); 10529 err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK, 10530 rack_stack_names, &num_stacks); 10531 if (err) { 10532 printf("Failed to register %s stack name for " 10533 "%s module\n", rack_stack_names[num_stacks], 10534 __XSTRING(MODNAME)); 10535 sysctl_ctx_free(&rack_sysctl_ctx); 10536 free_uma: 10537 uma_zdestroy(rack_zone); 10538 uma_zdestroy(rack_pcb_zone); 10539 rack_counter_destroy(); 10540 printf("Failed to register rack module -- err:%d\n", err); 10541 return (err); 10542 } 10543 tcp_lro_reg_mbufq(); 10544 rack_mod_inited = true; 10545 break; 10546 case MOD_QUIESCE: 10547 err = deregister_tcp_functions(&__tcp_rack, true, false); 10548 break; 10549 case MOD_UNLOAD: 10550 err = deregister_tcp_functions(&__tcp_rack, false, true); 10551 if (err == EBUSY) 10552 break; 10553 if (rack_mod_inited) { 10554 uma_zdestroy(rack_zone); 10555 uma_zdestroy(rack_pcb_zone); 10556 sysctl_ctx_free(&rack_sysctl_ctx); 10557 rack_counter_destroy(); 10558 rack_mod_inited = false; 10559 } 10560 tcp_lro_dereg_mbufq(); 10561 err = 0; 10562 break; 10563 default: 10564 return (EOPNOTSUPP); 10565 } 10566 return (err); 10567 } 10568 10569 static moduledata_t tcp_rack = { 10570 .name = __XSTRING(MODNAME), 10571 .evhand = tcp_addrack, 10572 .priv = 0 10573 }; 10574 10575 MODULE_VERSION(MODNAME, 1); 10576 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); 10577 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1); 10578