tcp_var.h revision 1.195
1 /* $NetBSD: tcp_var.h,v 1.195 2021/03/08 18:17:27 christos Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * @(#)COPYRIGHT 1.1 (NRL) 17 January 1995 34 * 35 * NRL grants permission for redistribution and use in source and binary 36 * forms, with or without modification, of the software and documentation 37 * created at NRL provided that the following conditions are met: 38 * 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 3. All advertising materials mentioning features or use of this software 45 * must display the following acknowledgements: 46 * This product includes software developed by the University of 47 * California, Berkeley and its contributors. 48 * This product includes software developed at the Information 49 * Technology Division, US Naval Research Laboratory. 50 * 4. Neither the name of the NRL nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS 55 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 56 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 57 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL NRL OR 58 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 59 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 60 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 61 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 62 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 63 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 64 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 65 * 66 * The views and conclusions contained in the software and documentation 67 * are those of the authors and should not be interpreted as representing 68 * official policies, either expressed or implied, of the US Naval 69 * Research Laboratory (NRL). 70 */ 71 72 /*- 73 * Copyright (c) 1997, 1998, 1999, 2001, 2005 The NetBSD Foundation, Inc. 74 * All rights reserved. 75 * 76 * This code is derived from software contributed to The NetBSD Foundation 77 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 78 * NASA Ames Research Center. 79 * This code is derived from software contributed to The NetBSD Foundation 80 * by Charles M. Hannum. 81 * 82 * Redistribution and use in source and binary forms, with or without 83 * modification, are permitted provided that the following conditions 84 * are met: 85 * 1. Redistributions of source code must retain the above copyright 86 * notice, this list of conditions and the following disclaimer. 87 * 2. Redistributions in binary form must reproduce the above copyright 88 * notice, this list of conditions and the following disclaimer in the 89 * documentation and/or other materials provided with the distribution. 90 * 91 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 92 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 93 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 94 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 95 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 96 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 97 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 98 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 99 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 100 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 101 * POSSIBILITY OF SUCH DAMAGE. 102 */ 103 104 /* 105 * Copyright (c) 1982, 1986, 1993, 1994, 1995 106 * The Regents of the University of California. All rights reserved. 107 * 108 * Redistribution and use in source and binary forms, with or without 109 * modification, are permitted provided that the following conditions 110 * are met: 111 * 1. Redistributions of source code must retain the above copyright 112 * notice, this list of conditions and the following disclaimer. 113 * 2. Redistributions in binary form must reproduce the above copyright 114 * notice, this list of conditions and the following disclaimer in the 115 * documentation and/or other materials provided with the distribution. 116 * 3. Neither the name of the University nor the names of its contributors 117 * may be used to endorse or promote products derived from this software 118 * without specific prior written permission. 119 * 120 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 121 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 122 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 123 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 124 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 125 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 126 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 127 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 128 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 129 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 130 * SUCH DAMAGE. 131 * 132 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95 133 */ 134 135 #ifndef _NETINET_TCP_VAR_H_ 136 #define _NETINET_TCP_VAR_H_ 137 138 #if defined(_KERNEL_OPT) 139 #include "opt_inet.h" 140 #include "opt_mbuftrace.h" 141 142 #endif 143 144 /* 145 * TCP kernel structures and variables. 146 */ 147 148 #include <sys/callout.h> 149 150 #ifdef TCP_SIGNATURE 151 /* 152 * Defines which are needed by the xform_tcp module and tcp_[in|out]put 153 * for SADB verification and lookup. 154 */ 155 #define TCP_SIGLEN 16 /* length of computed digest in bytes */ 156 #define TCP_KEYLEN_MIN 1 /* minimum length of TCP-MD5 key */ 157 #define TCP_KEYLEN_MAX 80 /* maximum length of TCP-MD5 key */ 158 /* 159 * Only a single SA per host may be specified at this time. An SPI is 160 * needed in order for the KEY_LOOKUP_SA() lookup to work. 161 */ 162 #define TCP_SIG_SPI 0x1000 163 #endif /* TCP_SIGNATURE */ 164 165 /* 166 * Tcp+ip header, after ip options removed. 167 */ 168 struct tcpiphdr { 169 struct ipovly ti_i; /* overlaid ip structure */ 170 struct tcphdr ti_t; /* tcp header */ 171 }; 172 #ifdef CTASSERT 173 CTASSERT(sizeof(struct tcpiphdr) == 40); 174 #endif 175 #define ti_x1 ti_i.ih_x1 176 #define ti_pr ti_i.ih_pr 177 #define ti_len ti_i.ih_len 178 #define ti_src ti_i.ih_src 179 #define ti_dst ti_i.ih_dst 180 #define ti_sport ti_t.th_sport 181 #define ti_dport ti_t.th_dport 182 #define ti_seq ti_t.th_seq 183 #define ti_ack ti_t.th_ack 184 #define ti_x2 ti_t.th_x2 185 #define ti_off ti_t.th_off 186 #define ti_flags ti_t.th_flags 187 #define ti_win ti_t.th_win 188 #define ti_sum ti_t.th_sum 189 #define ti_urp ti_t.th_urp 190 191 /* 192 * SACK option block. 193 */ 194 struct sackblk { 195 tcp_seq left; /* Left edge of sack block. */ 196 tcp_seq right; /* Right edge of sack block. */ 197 }; 198 199 TAILQ_HEAD(sackhead, sackhole); 200 struct sackhole { 201 tcp_seq start; 202 tcp_seq end; 203 tcp_seq rxmit; 204 205 TAILQ_ENTRY(sackhole) sackhole_q; 206 }; 207 208 /* 209 * Tcp control block, one per tcp; fields: 210 */ 211 struct tcpcb { 212 int t_family; /* address family on the wire */ 213 struct ipqehead segq; /* sequencing queue */ 214 int t_segqlen; /* length of the above */ 215 callout_t t_timer[TCPT_NTIMERS];/* tcp timers */ 216 short t_state; /* state of this connection */ 217 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 218 uint32_t t_rxtcur; /* current retransmit value */ 219 short t_dupacks; /* consecutive dup acks recd */ 220 /* 221 * t_partialacks: 222 * <0 not in fast recovery. 223 * ==0 in fast recovery. has not received partial acks 224 * >0 in fast recovery. has received partial acks 225 */ 226 short t_partialacks; /* partials acks during fast rexmit */ 227 u_short t_peermss; /* peer's maximum segment size */ 228 u_short t_ourmss; /* our's maximum segment size */ 229 u_short t_segsz; /* current segment size in use */ 230 char t_force; /* 1 if forcing out a byte */ 231 u_int t_flags; 232 #define TF_ACKNOW 0x0001 /* ack peer immediately */ 233 #define TF_DELACK 0x0002 /* ack, but try to delay it */ 234 #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */ 235 #define TF_NOOPT 0x0008 /* don't use tcp options */ 236 #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */ 237 #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */ 238 #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */ 239 #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */ 240 #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */ 241 #define TF_SYN_REXMT 0x0400 /* rexmit timer fired on SYN */ 242 #define TF_WILL_SACK 0x0800 /* try to use SACK */ 243 #define TF_REASSEMBLING 0x1000 /* we're busy reassembling */ 244 #define TF_DEAD 0x2000 /* dead and to-be-released */ 245 #define TF_PMTUD_PEND 0x4000 /* Path MTU Discovery pending */ 246 #define TF_ECN_PERMIT 0x10000 /* other side said is ECN-ready */ 247 #define TF_ECN_SND_CWR 0x20000 /* ECN CWR in queue */ 248 #define TF_ECN_SND_ECE 0x40000 /* ECN ECE in queue */ 249 #define TF_SIGNATURE 0x400000 /* require MD5 digests (RFC2385) */ 250 251 252 struct mbuf *t_template; /* skeletal packet for transmit */ 253 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 254 struct in6pcb *t_in6pcb; /* back pointer to internet pcb */ 255 callout_t t_delack_ch; /* delayed ACK callout */ 256 /* 257 * The following fields are used as in the protocol specification. 258 * See RFC793, Dec. 1981, page 21. 259 */ 260 /* send sequence variables */ 261 tcp_seq snd_una; /* send unacknowledged */ 262 tcp_seq snd_nxt; /* send next */ 263 tcp_seq snd_up; /* send urgent pointer */ 264 tcp_seq snd_wl1; /* window update seg seq number */ 265 tcp_seq snd_wl2; /* window update seg ack number */ 266 tcp_seq iss; /* initial send sequence number */ 267 u_long snd_wnd; /* send window */ 268 /* 269 * snd_recover 270 * it's basically same as the "recover" variable in RFC 2852 (NewReno). 271 * when entering fast retransmit, it's set to snd_max. 272 * newreno uses this to detect partial ack. 273 * snd_high 274 * it's basically same as the "send_high" variable in RFC 2852 (NewReno). 275 * on each RTO, it's set to snd_max. 276 * newreno uses this to avoid false fast retransmits. 277 */ 278 tcp_seq snd_recover; 279 tcp_seq snd_high; 280 /* receive sequence variables */ 281 u_long rcv_wnd; /* receive window */ 282 tcp_seq rcv_nxt; /* receive next */ 283 tcp_seq rcv_up; /* receive urgent pointer */ 284 tcp_seq irs; /* initial receive sequence number */ 285 /* 286 * Additional variables for this implementation. 287 */ 288 /* receive variables */ 289 tcp_seq rcv_adv; /* advertised window */ 290 291 /* 292 * retransmit variables 293 * 294 * snd_max 295 * the highest sequence number we've ever sent. 296 * used to recognize retransmits. 297 */ 298 tcp_seq snd_max; 299 300 /* congestion control (for slow start, source quench, retransmit after loss) */ 301 u_long snd_cwnd; /* congestion-controlled window */ 302 u_long snd_ssthresh; /* snd_cwnd size threshhold for 303 * for slow start exponential to 304 * linear switch 305 */ 306 /* auto-sizing variables */ 307 u_int rfbuf_cnt; /* recv buffer autoscaling byte count */ 308 uint32_t rfbuf_ts; /* recv buffer autoscaling timestamp */ 309 310 /* 311 * transmit timing stuff. See below for scale of srtt and rttvar. 312 * "Variance" is actually smoothed difference. 313 */ 314 uint32_t t_rcvtime; /* time last segment received */ 315 uint32_t t_rtttime; /* time we started measuring rtt */ 316 tcp_seq t_rtseq; /* sequence number being timed */ 317 int32_t t_srtt; /* smoothed round-trip time */ 318 int32_t t_rttvar; /* variance in round-trip time */ 319 uint32_t t_rttmin; /* minimum rtt allowed */ 320 u_long max_sndwnd; /* largest window peer has offered */ 321 322 /* out-of-band data */ 323 char t_oobflags; /* have some */ 324 char t_iobc; /* input character */ 325 #define TCPOOB_HAVEDATA 0x01 326 #define TCPOOB_HADDATA 0x02 327 short t_softerror; /* possible error not yet reported */ 328 329 /* RFC 1323 variables */ 330 u_char snd_scale; /* window scaling for send window */ 331 u_char rcv_scale; /* window scaling for recv window */ 332 u_char request_r_scale; /* pending window scaling */ 333 u_char requested_s_scale; 334 u_int32_t ts_recent; /* timestamp echo data */ 335 u_int32_t ts_recent_age; /* when last updated */ 336 u_int32_t ts_timebase; /* our timebase */ 337 tcp_seq last_ack_sent; 338 339 /* RFC 3465 variables */ 340 u_long t_bytes_acked; /* ABC "bytes_acked" parameter */ 341 342 /* SACK stuff */ 343 #define TCP_SACK_MAX 3 344 #define TCPSACK_NONE 0 345 #define TCPSACK_HAVED 1 346 u_char rcv_sack_flags; /* SACK flags. */ 347 struct sackblk rcv_dsack_block; /* RX D-SACK block. */ 348 struct ipqehead timeq; /* time sequenced queue. */ 349 struct sackhead snd_holes; /* TX SACK holes. */ 350 int snd_numholes; /* Number of TX SACK holes. */ 351 tcp_seq rcv_lastsack; /* last seq number(+1) sack'd by rcv'r*/ 352 tcp_seq sack_newdata; /* New data xmitted in this recovery 353 episode starts at this seq number*/ 354 tcp_seq snd_fack; /* FACK TCP. Forward-most data held by 355 peer. */ 356 357 /* CUBIC variables */ 358 ulong snd_cubic_wmax; /* W_max */ 359 ulong snd_cubic_wmax_last; /* Used for fast convergence */ 360 ulong snd_cubic_ctime; /* Last congestion time */ 361 362 /* pointer for syn cache entries*/ 363 LIST_HEAD(, syn_cache) t_sc; /* list of entries by this tcb */ 364 365 /* prediction of next mbuf when using large window sizes */ 366 struct mbuf *t_lastm; /* last mbuf that data was sent from */ 367 int t_inoff; /* data offset in previous mbuf */ 368 int t_lastoff; /* last data address in mbuf chain */ 369 int t_lastlen; /* last length read from mbuf chain */ 370 371 /* Path-MTU discovery blackhole detection */ 372 int t_mtudisc; /* perform mtudisc for this tcb */ 373 /* Path-MTU Discovery Information */ 374 u_int t_pmtud_mss_acked; /* MSS acked, lower bound for MTU */ 375 u_int t_pmtud_mtu_sent; /* MTU used, upper bound for MTU */ 376 tcp_seq t_pmtud_th_seq; /* TCP SEQ from ICMP payload */ 377 u_int t_pmtud_nextmtu; /* Advertised Next-Hop MTU from ICMP */ 378 u_short t_pmtud_ip_len; /* IP length from ICMP payload */ 379 u_short t_pmtud_ip_hl; /* IP header length from ICMP payload */ 380 381 uint8_t t_ecn_retries; /* # of ECN setup retries */ 382 383 const struct tcp_congctl *t_congctl; /* per TCB congctl algorithm */ 384 385 /* Keepalive per socket */ 386 u_int t_keepinit; 387 u_int t_keepidle; 388 u_int t_keepintvl; 389 u_int t_keepcnt; 390 u_int t_maxidle; /* t_keepcnt * t_keepintvl */ 391 392 u_int t_msl; /* MSL to use for this connexion */ 393 394 /* maintain a few stats per connection: */ 395 uint32_t t_rcvoopack; /* out-of-order packets received */ 396 uint32_t t_sndrexmitpack; /* retransmit packets sent */ 397 uint32_t t_sndzerowin; /* zero-window updates sent */ 398 }; 399 400 /* 401 * Macros to aid ECN TCP. 402 */ 403 #define TCP_ECN_ALLOWED(tp) (tp->t_flags & TF_ECN_PERMIT) 404 405 /* 406 * Macros to aid SACK/FACK TCP. 407 */ 408 #define TCP_SACK_ENABLED(tp) (tp->t_flags & TF_WILL_SACK) 409 #define TCP_FACK_FASTRECOV(tp) \ 410 (TCP_SACK_ENABLED(tp) && \ 411 (SEQ_GT(tp->snd_fack, tp->snd_una + tcprexmtthresh * tp->t_segsz))) 412 413 #ifdef _KERNEL 414 /* 415 * TCP reassembly queue locks. 416 */ 417 static __inline int tcp_reass_lock_try (struct tcpcb *) 418 __unused; 419 static __inline void tcp_reass_unlock (struct tcpcb *) 420 __unused; 421 422 static __inline int 423 tcp_reass_lock_try(struct tcpcb *tp) 424 { 425 int s; 426 427 /* 428 * Use splvm() -- we're blocking things that would cause 429 * mbuf allocation. 430 */ 431 s = splvm(); 432 if (tp->t_flags & TF_REASSEMBLING) { 433 splx(s); 434 return (0); 435 } 436 tp->t_flags |= TF_REASSEMBLING; 437 splx(s); 438 return (1); 439 } 440 441 static __inline void 442 tcp_reass_unlock(struct tcpcb *tp) 443 { 444 int s; 445 446 s = splvm(); 447 KASSERT((tp->t_flags & TF_REASSEMBLING) != 0); 448 tp->t_flags &= ~TF_REASSEMBLING; 449 splx(s); 450 } 451 452 #ifdef DIAGNOSTIC 453 #define TCP_REASS_LOCK(tp) \ 454 do { \ 455 if (tcp_reass_lock_try(tp) == 0) { \ 456 printf("%s:%d: tcpcb %p reass already locked\n", \ 457 __FILE__, __LINE__, tp); \ 458 panic("tcp_reass_lock"); \ 459 } \ 460 } while (/*CONSTCOND*/ 0) 461 #define TCP_REASS_LOCK_CHECK(tp) \ 462 do { \ 463 if (((tp)->t_flags & TF_REASSEMBLING) == 0) { \ 464 printf("%s:%d: tcpcb %p reass lock not held\n", \ 465 __FILE__, __LINE__, tp); \ 466 panic("tcp reass lock check"); \ 467 } \ 468 } while (/*CONSTCOND*/ 0) 469 #else 470 #define TCP_REASS_LOCK(tp) (void) tcp_reass_lock_try((tp)) 471 #define TCP_REASS_LOCK_CHECK(tp) /* nothing */ 472 #endif 473 474 #define TCP_REASS_UNLOCK(tp) tcp_reass_unlock((tp)) 475 #endif /* _KERNEL */ 476 477 /* 478 * Queue for delayed ACK processing. 479 */ 480 #ifdef _KERNEL 481 extern int tcp_delack_ticks; 482 void tcp_delack(void *); 483 484 #define TCP_RESTART_DELACK(tp) \ 485 callout_reset(&(tp)->t_delack_ch, tcp_delack_ticks, \ 486 tcp_delack, tp) 487 488 #define TCP_SET_DELACK(tp) \ 489 do { \ 490 if (((tp)->t_flags & TF_DELACK) == 0) { \ 491 (tp)->t_flags |= TF_DELACK; \ 492 TCP_RESTART_DELACK(tp); \ 493 } \ 494 } while (/*CONSTCOND*/0) 495 496 #define TCP_CLEAR_DELACK(tp) \ 497 do { \ 498 if ((tp)->t_flags & TF_DELACK) { \ 499 (tp)->t_flags &= ~TF_DELACK; \ 500 callout_stop(&(tp)->t_delack_ch); \ 501 } \ 502 } while (/*CONSTCOND*/0) 503 #endif /* _KERNEL */ 504 505 /* 506 * Compute the current timestamp for a connection. 507 */ 508 #define TCP_TIMESTAMP(tp) (tcp_now - (tp)->ts_timebase) 509 510 /* 511 * Handy way of passing around TCP option info. 512 */ 513 struct tcp_opt_info { 514 int ts_present; 515 u_int32_t ts_val; 516 u_int32_t ts_ecr; 517 u_int16_t maxseg; 518 }; 519 520 #define TOF_SIGNATURE 0x0040 /* signature option present */ 521 #define TOF_SIGLEN 0x0080 /* sigature length valid (RFC2385) */ 522 523 /* 524 * Data for the TCP compressed state engine. 525 */ 526 union syn_cache_sa { 527 struct sockaddr sa; 528 struct sockaddr_in sin; 529 #if 1 /*def INET6*/ 530 struct sockaddr_in6 sin6; 531 #endif 532 }; 533 534 struct syn_cache { 535 TAILQ_ENTRY(syn_cache) sc_bucketq; /* link on bucket list */ 536 callout_t sc_timer; /* rexmt timer */ 537 struct route sc_route; 538 long sc_win; /* advertised window */ 539 int sc_bucketidx; /* our bucket index */ 540 u_int32_t sc_hash; 541 u_int32_t sc_timestamp; /* timestamp from SYN */ 542 u_int32_t sc_timebase; /* our local timebase */ 543 union syn_cache_sa sc_src; 544 union syn_cache_sa sc_dst; 545 tcp_seq sc_irs; 546 tcp_seq sc_iss; 547 u_int sc_rxtcur; /* current rxt timeout */ 548 u_int sc_rxttot; /* total time spend on queues */ 549 u_short sc_rxtshift; /* for computing backoff */ 550 u_short sc_flags; 551 552 #define SCF_UNREACH 0x0001 /* we've had an unreach error */ 553 #define SCF_TIMESTAMP 0x0002 /* peer will do timestamps */ 554 #define SCF_DEAD 0x0004 /* this entry to be released */ 555 #define SCF_SACK_PERMIT 0x0008 /* peer will do SACK */ 556 #define SCF_ECN_PERMIT 0x0010 /* peer will do ECN */ 557 #define SCF_SIGNATURE 0x40 /* send MD5 digests */ 558 559 struct mbuf *sc_ipopts; /* IP options */ 560 u_int16_t sc_peermaxseg; 561 u_int16_t sc_ourmaxseg; 562 u_int8_t sc_request_r_scale : 4, 563 sc_requested_s_scale : 4; 564 565 struct tcpcb *sc_tp; /* tcb for listening socket */ 566 LIST_ENTRY(syn_cache) sc_tpq; /* list of entries by same tp */ 567 }; 568 569 struct syn_cache_head { 570 TAILQ_HEAD(, syn_cache) sch_bucket; /* bucket entries */ 571 u_short sch_length; /* # entries in bucket */ 572 }; 573 574 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 575 #ifdef INET6 576 #define in6totcpcb(ip) ((struct tcpcb *)(ip)->in6p_ppcb) 577 #endif 578 #ifndef INET6 579 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 580 #else 581 #define sototcpcb(so) (((so)->so_proto->pr_domain->dom_family == AF_INET) \ 582 ? intotcpcb(sotoinpcb(so)) \ 583 : in6totcpcb(sotoin6pcb(so))) 584 #endif 585 586 /* 587 * See RFC2988 for a discussion of RTO calculation; comments assume 588 * familiarity with that document. 589 * 590 * The smoothed round-trip time and estimated variance are stored as 591 * fixed point numbers. Historically, srtt was scaled by 592 * TCP_RTT_SHIFT bits, and rttvar by TCP_RTTVAR_SHIFT bits. Because 593 * the values coincide with the alpha and beta parameters suggested 594 * for RTO calculation (1/8 for srtt, 1/4 for rttvar), the combination 595 * of computing 1/8 of the new value and transforming it to the 596 * fixed-point representation required zero instructions. However, 597 * the storage representations no longer coincide with the alpha/beta 598 * shifts; instead, more fractional bits are present. 599 * 600 * The storage representation of srtt is 1/32 slow ticks, or 1/64 s. 601 * (The assumption that a slow tick is 500 ms should not be present in 602 * the code.) 603 * 604 * The storage representation of rttvar is 1/16 slow ticks, or 1/32 s. 605 * There may be some confusion about this in the code. 606 * 607 * For historical reasons, these scales are also used in smoothing the 608 * average (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 609 * This results in alpha of 0.125 and beta of 0.25, following RFC2988 610 * section 2.3 611 * 612 * XXX Change SHIFT values to LGWEIGHT and REP_SHIFT, and adjust 613 * the code to use the correct ones. 614 */ 615 #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ 616 #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */ 617 618 /* 619 * Compute TCP retransmission timer, following RFC2988. 620 * This macro returns a value in slow timeout ticks. 621 * 622 * Section 2.2 requires that the RTO value be 623 * srtt + max(G, 4*RTTVAR) 624 * where G is the clock granularity. 625 * 626 * This comment has not necessarily been updated for the new storage 627 * representation: 628 * 629 * Because of the way we do the smoothing, srtt and rttvar 630 * will each average +1/2 tick of bias. When we compute 631 * the retransmit timer, we want 1/2 tick of rounding and 632 * 1 extra tick because of +-1/2 tick uncertainty in the 633 * firing of the timer. The bias will give us exactly the 634 * 1.5 tick we need. But, because the bias is 635 * statistical, we have to test that we don't drop below 636 * the minimum feasible timer (which is 2 ticks). 637 * This macro assumes that the value of 1<<TCP_RTTVAR_SHIFT 638 * is the same as the multiplier for rttvar. 639 * 640 * This macro appears to be wrong; it should be checking rttvar*4 in 641 * ticks and making sure we use 1 instead if rttvar*4 rounds to 0. It 642 * appears to be treating srtt as being in the old storage 643 * representation, resulting in a factor of 4 extra. 644 */ 645 #define TCP_REXMTVAL(tp) \ 646 ((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) >> 2) 647 648 /* 649 * Compute the initial window for slow start. 650 */ 651 #define TCP_INITIAL_WINDOW(iw, segsz) \ 652 uimin((iw) * (segsz), uimax(2 * (segsz), tcp_init_win_max[(iw)])) 653 654 /* 655 * TCP statistics. 656 * Each counter is an unsigned 64-bit value. 657 * 658 * Many of these should be kept per connection, but that's inconvenient 659 * at the moment. 660 */ 661 #define TCP_STAT_CONNATTEMPT 0 /* connections initiated */ 662 #define TCP_STAT_ACCEPTS 1 /* connections accepted */ 663 #define TCP_STAT_CONNECTS 2 /* connections established */ 664 #define TCP_STAT_DROPS 3 /* connections dropped */ 665 #define TCP_STAT_CONNDROPS 4 /* embryonic connections dropped */ 666 #define TCP_STAT_CLOSED 5 /* conn. closed (includes drops) */ 667 #define TCP_STAT_SEGSTIMED 6 /* segs where we tried to get rtt */ 668 #define TCP_STAT_RTTUPDATED 7 /* times we succeeded */ 669 #define TCP_STAT_DELACK 8 /* delayed ACKs sent */ 670 #define TCP_STAT_TIMEOUTDROP 9 /* conn. dropped in rxmt timeout */ 671 #define TCP_STAT_REXMTTIMEO 10 /* retransmit timeouts */ 672 #define TCP_STAT_PERSISTTIMEO 11 /* persist timeouts */ 673 #define TCP_STAT_KEEPTIMEO 12 /* keepalive timeouts */ 674 #define TCP_STAT_KEEPPROBE 13 /* keepalive probes sent */ 675 #define TCP_STAT_KEEPDROPS 14 /* connections dropped in keepalive */ 676 #define TCP_STAT_PERSISTDROPS 15 /* connections dropped in persist */ 677 #define TCP_STAT_CONNSDRAINED 16 /* connections drained due to memory 678 shortage */ 679 #define TCP_STAT_PMTUBLACKHOLE 17 /* PMTUD blackhole detected */ 680 #define TCP_STAT_SNDTOTAL 18 /* total packets sent */ 681 #define TCP_STAT_SNDPACK 19 /* data packlets sent */ 682 #define TCP_STAT_SNDBYTE 20 /* data bytes sent */ 683 #define TCP_STAT_SNDREXMITPACK 21 /* data packets retransmitted */ 684 #define TCP_STAT_SNDREXMITBYTE 22 /* data bytes retransmitted */ 685 #define TCP_STAT_SNDACKS 23 /* ACK-only packets sent */ 686 #define TCP_STAT_SNDPROBE 24 /* window probes sent */ 687 #define TCP_STAT_SNDURG 25 /* packets sent with URG only */ 688 #define TCP_STAT_SNDWINUP 26 /* window update-only packets sent */ 689 #define TCP_STAT_SNDCTRL 27 /* control (SYN|FIN|RST) packets sent */ 690 #define TCP_STAT_RCVTOTAL 28 /* total packets received */ 691 #define TCP_STAT_RCVPACK 29 /* packets received in sequence */ 692 #define TCP_STAT_RCVBYTE 30 /* bytes received in sequence */ 693 #define TCP_STAT_RCVBADSUM 31 /* packets received with cksum errs */ 694 #define TCP_STAT_RCVBADOFF 32 /* packets received with bad offset */ 695 #define TCP_STAT_RCVMEMDROP 33 /* packets dropped for lack of memory */ 696 #define TCP_STAT_RCVSHORT 34 /* packets received too short */ 697 #define TCP_STAT_RCVDUPPACK 35 /* duplicate-only packets received */ 698 #define TCP_STAT_RCVDUPBYTE 36 /* duplicate-only bytes received */ 699 #define TCP_STAT_RCVPARTDUPPACK 37 /* packets with some duplicate data */ 700 #define TCP_STAT_RCVPARTDUPBYTE 38 /* dup. bytes in part-dup. packets */ 701 #define TCP_STAT_RCVOOPACK 39 /* out-of-order packets received */ 702 #define TCP_STAT_RCVOOBYTE 40 /* out-of-order bytes received */ 703 #define TCP_STAT_RCVPACKAFTERWIN 41 /* packets with data after window */ 704 #define TCP_STAT_RCVBYTEAFTERWIN 42 /* bytes received after window */ 705 #define TCP_STAT_RCVAFTERCLOSE 43 /* packets received after "close" */ 706 #define TCP_STAT_RCVWINPROBE 44 /* rcvd window probe packets */ 707 #define TCP_STAT_RCVDUPACK 45 /* rcvd duplicate ACKs */ 708 #define TCP_STAT_RCVACKTOOMUCH 46 /* rcvd ACKs for unsent data */ 709 #define TCP_STAT_RCVACKPACK 47 /* rcvd ACK packets */ 710 #define TCP_STAT_RCVACKBYTE 48 /* bytes ACKed by rcvd ACKs */ 711 #define TCP_STAT_RCVWINUPD 49 /* rcvd window update packets */ 712 #define TCP_STAT_PAWSDROP 50 /* segments dropped due to PAWS */ 713 #define TCP_STAT_PREDACK 51 /* times hdr predict OK for ACKs */ 714 #define TCP_STAT_PREDDAT 52 /* times hdr predict OK for data pkts */ 715 #define TCP_STAT_PCBHASHMISS 53 /* input packets missing PCB hash */ 716 #define TCP_STAT_NOPORT 54 /* no socket on port */ 717 #define TCP_STAT_BADSYN 55 /* received ACK for which we have 718 no SYN in compressed state */ 719 #define TCP_STAT_DELAYED_FREE 56 /* delayed pool_put() of tcpcb */ 720 #define TCP_STAT_SC_ADDED 57 /* # of sc entries added */ 721 #define TCP_STAT_SC_COMPLETED 58 /* # of sc connections completed */ 722 #define TCP_STAT_SC_TIMED_OUT 59 /* # of sc entries timed out */ 723 #define TCP_STAT_SC_OVERFLOWED 60 /* # of sc drops due to overflow */ 724 #define TCP_STAT_SC_RESET 61 /* # of sc drops due to RST */ 725 #define TCP_STAT_SC_UNREACH 62 /* # of sc drops due to ICMP unreach */ 726 #define TCP_STAT_SC_BUCKETOVERFLOW 63 /* # of sc drops due to bucket ovflow */ 727 #define TCP_STAT_SC_ABORTED 64 /* # of sc entries aborted (no mem) */ 728 #define TCP_STAT_SC_DUPESYN 65 /* # of duplicate SYNs received */ 729 #define TCP_STAT_SC_DROPPED 66 /* # of SYNs dropped (no route/mem) */ 730 #define TCP_STAT_SC_COLLISIONS 67 /* # of sc hash collisions */ 731 #define TCP_STAT_SC_RETRANSMITTED 68 /* # of sc retransmissions */ 732 #define TCP_STAT_SC_DELAYED_FREE 69 /* # of delayed pool_put()s */ 733 #define TCP_STAT_SELFQUENCH 70 /* # of ENOBUFS we get on output */ 734 #define TCP_STAT_BADSIG 71 /* # of drops due to bad signature */ 735 #define TCP_STAT_GOODSIG 72 /* # of packets with good signature */ 736 #define TCP_STAT_ECN_SHS 73 /* # of successful ECN handshakes */ 737 #define TCP_STAT_ECN_CE 74 /* # of packets with CE bit */ 738 #define TCP_STAT_ECN_ECT 75 /* # of packets with ECT(0) bit */ 739 740 #define TCP_NSTATS 76 741 742 /* 743 * Names for TCP sysctl objects. 744 */ 745 #define TCPCTL_RFC1323 1 /* RFC1323 timestamps/scaling */ 746 #define TCPCTL_SENDSPACE 2 /* default send buffer */ 747 #define TCPCTL_RECVSPACE 3 /* default recv buffer */ 748 #define TCPCTL_MSSDFLT 4 /* default seg size */ 749 #define TCPCTL_SYN_CACHE_LIMIT 5 /* max size of comp. state engine */ 750 #define TCPCTL_SYN_BUCKET_LIMIT 6 /* max size of hash bucket */ 751 #if 0 /*obsoleted*/ 752 #define TCPCTL_SYN_CACHE_INTER 7 /* interval of comp. state timer */ 753 #endif 754 #define TCPCTL_INIT_WIN 8 /* initial window */ 755 #define TCPCTL_MSS_IFMTU 9 /* mss from interface, not in_maxmtu */ 756 #define TCPCTL_SACK 10 /* RFC2018 selective acknowledgement */ 757 #define TCPCTL_WSCALE 11 /* RFC1323 window scaling */ 758 #define TCPCTL_TSTAMP 12 /* RFC1323 timestamps */ 759 #if 0 /*obsoleted*/ 760 #define TCPCTL_COMPAT_42 13 /* 4.2BSD TCP bug work-arounds */ 761 #endif 762 #define TCPCTL_CWM 14 /* Congestion Window Monitoring */ 763 #define TCPCTL_CWM_BURSTSIZE 15 /* burst size allowed by CWM */ 764 #define TCPCTL_ACK_ON_PUSH 16 /* ACK immediately on PUSH */ 765 #define TCPCTL_KEEPIDLE 17 /* keepalive idle time */ 766 #define TCPCTL_KEEPINTVL 18 /* keepalive probe interval */ 767 #define TCPCTL_KEEPCNT 19 /* keepalive count */ 768 #define TCPCTL_SLOWHZ 20 /* PR_SLOWHZ (read-only) */ 769 #define TCPCTL_NEWRENO 21 /* NewReno Congestion Control */ 770 #define TCPCTL_LOG_REFUSED 22 /* Log refused connections */ 771 #if 0 /*obsoleted*/ 772 #define TCPCTL_RSTRATELIMIT 23 /* RST rate limit */ 773 #endif 774 #define TCPCTL_RSTPPSLIMIT 24 /* RST pps limit */ 775 #define TCPCTL_DELACK_TICKS 25 /* # ticks to delay ACK */ 776 #define TCPCTL_INIT_WIN_LOCAL 26 /* initial window for local nets */ 777 #define TCPCTL_IDENT 27 /* rfc 931 identd */ 778 #define TCPCTL_ACKDROPRATELIMIT 28 /* SYN/RST -> ACK rate limit */ 779 #define TCPCTL_LOOPBACKCKSUM 29 /* do TCP checksum on loopback */ 780 #define TCPCTL_STATS 30 /* TCP statistics */ 781 #define TCPCTL_DEBUG 31 /* TCP debug sockets */ 782 #define TCPCTL_DEBX 32 /* # of tcp debug sockets */ 783 #define TCPCTL_DROP 33 /* drop tcp connection */ 784 #define TCPCTL_MSL 34 /* Max Segment Life */ 785 786 #ifdef _KERNEL 787 788 extern struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 789 extern const struct pr_usrreqs tcp_usrreqs; 790 791 extern u_int32_t tcp_now; /* for RFC 1323 timestamps */ 792 extern int tcp_do_rfc1323; /* enabled/disabled? */ 793 extern int tcp_do_sack; /* SACK enabled/disabled? */ 794 extern int tcp_do_win_scale; /* RFC1323 window scaling enabled/disabled? */ 795 extern int tcp_do_timestamps; /* RFC1323 timestamps enabled/disabled? */ 796 extern int tcp_mssdflt; /* default seg size */ 797 extern int tcp_minmss; /* minimal seg size */ 798 extern int tcp_msl; /* max segment life */ 799 extern int tcp_init_win; /* initial window */ 800 extern int tcp_init_win_local; /* initial window for local nets */ 801 extern int tcp_init_win_max[11];/* max sizes for values of tcp_init_win_* */ 802 extern int tcp_mss_ifmtu; /* take MSS from interface, not in_maxmtu */ 803 extern int tcp_cwm; /* enable Congestion Window Monitoring */ 804 extern int tcp_cwm_burstsize; /* burst size allowed by CWM */ 805 extern int tcp_ack_on_push; /* ACK immediately on PUSH */ 806 extern int tcp_syn_cache_limit; /* max entries for compressed state engine */ 807 extern int tcp_syn_bucket_limit;/* max entries per hash bucket */ 808 extern int tcp_log_refused; /* log refused connections */ 809 extern int tcp_do_ecn; /* TCP ECN enabled/disabled? */ 810 extern int tcp_ecn_maxretries; /* Max ECN setup retries */ 811 extern int tcp_do_rfc1948; /* ISS by cryptographic hash */ 812 extern int tcp_sack_tp_maxholes; /* Max holes per connection. */ 813 extern int tcp_sack_globalmaxholes; /* Max holes per system. */ 814 extern int tcp_sack_globalholes; /* Number of holes present. */ 815 extern int tcp_do_abc; /* RFC3465 ABC enabled/disabled? */ 816 extern int tcp_abc_aggressive; /* 1: L=2*SMSS 0: L=1*SMSS */ 817 818 extern int tcp_msl_enable; /* enable TIME_WAIT truncation */ 819 extern int tcp_msl_loop; /* MSL for loopback */ 820 extern int tcp_msl_local; /* MSL for 'local' */ 821 extern int tcp_msl_remote; /* MSL otherwise */ 822 extern int tcp_msl_remote_threshold; /* RTT threshold */ 823 extern int tcp_rttlocal; /* Use RTT to decide who's 'local' */ 824 extern int tcp4_vtw_enable; 825 extern int tcp6_vtw_enable; 826 extern int tcp_vtw_was_enabled; 827 extern int tcp_vtw_entries; 828 829 extern int tcp_rst_ppslim; 830 extern int tcp_ackdrop_ppslim; 831 832 extern int tcp_syn_cache_size; 833 extern struct syn_cache_head tcp_syn_cache[]; 834 extern u_long syn_cache_count; 835 836 #ifdef MBUFTRACE 837 extern struct mowner tcp_rx_mowner; 838 extern struct mowner tcp_tx_mowner; 839 extern struct mowner tcp_reass_mowner; 840 extern struct mowner tcp_sock_mowner; 841 extern struct mowner tcp_sock_rx_mowner; 842 extern struct mowner tcp_sock_tx_mowner; 843 extern struct mowner tcp_mowner; 844 #endif 845 846 extern int tcp_do_autorcvbuf; 847 extern int tcp_autorcvbuf_inc; 848 extern int tcp_autorcvbuf_max; 849 extern int tcp_do_autosndbuf; 850 extern int tcp_autosndbuf_inc; 851 extern int tcp_autosndbuf_max; 852 853 struct secasvar; 854 855 void tcp_canceltimers(struct tcpcb *); 856 struct tcpcb * 857 tcp_close(struct tcpcb *); 858 int tcp_isdead(struct tcpcb *); 859 #ifdef INET6 860 void *tcp6_ctlinput(int, const struct sockaddr *, void *); 861 #endif 862 void *tcp_ctlinput(int, const struct sockaddr *, void *); 863 int tcp_ctloutput(int, struct socket *, struct sockopt *); 864 struct tcpcb * 865 tcp_disconnect1(struct tcpcb *); 866 struct tcpcb * 867 tcp_drop(struct tcpcb *, int); 868 #ifdef TCP_SIGNATURE 869 int tcp_signature_apply(void *, void *, u_int); 870 struct secasvar *tcp_signature_getsav(struct mbuf *); 871 int tcp_signature(struct mbuf *, struct tcphdr *, int, struct secasvar *, 872 char *); 873 #endif 874 void tcp_drain(void); 875 void tcp_drainstub(void); 876 void tcp_established(struct tcpcb *); 877 void tcp_init(void); 878 void tcp_init_common(unsigned); 879 #ifdef INET6 880 int tcp6_input(struct mbuf **, int *, int); 881 #endif 882 void tcp_input(struct mbuf *, int, int); 883 u_int tcp_hdrsz(struct tcpcb *); 884 u_long tcp_mss_to_advertise(const struct ifnet *, int); 885 void tcp_mss_from_peer(struct tcpcb *, int); 886 void tcp_tcpcb_template(void); 887 struct tcpcb * 888 tcp_newtcpcb(int, void *); 889 void tcp_notify(struct inpcb *, int); 890 #ifdef INET6 891 void tcp6_notify(struct in6pcb *, int); 892 #endif 893 u_int tcp_optlen(struct tcpcb *); 894 int tcp_output(struct tcpcb *); 895 void tcp_pulloutofband(struct socket *, 896 struct tcphdr *, struct mbuf *, int); 897 void tcp_quench(struct inpcb *); 898 #ifdef INET6 899 void tcp6_quench(struct in6pcb *); 900 #endif 901 void tcp_mtudisc(struct inpcb *, int); 902 #ifdef INET6 903 void tcp6_mtudisc_callback(struct in6_addr *); 904 #endif 905 906 void tcpipqent_init(void); 907 struct ipqent *tcpipqent_alloc(void); 908 void tcpipqent_free(struct ipqent *); 909 910 int tcp_respond(struct tcpcb *, struct mbuf *, struct mbuf *, 911 struct tcphdr *, tcp_seq, tcp_seq, int); 912 void tcp_rmx_rtt(struct tcpcb *); 913 void tcp_setpersist(struct tcpcb *); 914 #ifdef TCP_SIGNATURE 915 int tcp_signature_compute(struct mbuf *, struct tcphdr *, int, int, 916 int, u_char *, u_int); 917 #endif 918 void tcp_fasttimo(void); 919 struct mbuf * 920 tcp_template(struct tcpcb *); 921 void tcp_trace(short, short, struct tcpcb *, struct mbuf *, int); 922 struct tcpcb * 923 tcp_usrclosed(struct tcpcb *); 924 void tcp_usrreq_init(void); 925 void tcp_xmit_timer(struct tcpcb *, uint32_t); 926 tcp_seq tcp_new_iss(struct tcpcb *); 927 tcp_seq tcp_new_iss1(void *, void *, u_int16_t, u_int16_t, size_t); 928 929 void tcp_sack_init(void); 930 void tcp_new_dsack(struct tcpcb *, tcp_seq, u_int32_t); 931 void tcp_sack_option(struct tcpcb *, const struct tcphdr *, 932 const u_char *, int); 933 void tcp_del_sackholes(struct tcpcb *, const struct tcphdr *); 934 void tcp_free_sackholes(struct tcpcb *); 935 void tcp_sack_adjust(struct tcpcb *tp); 936 struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt); 937 int tcp_sack_numblks(const struct tcpcb *); 938 #define TCP_SACK_OPTLEN(nblks) ((nblks) * 8 + 2 + 2) 939 940 void tcp_statinc(u_int); 941 void tcp_statadd(u_int, uint64_t); 942 943 int syn_cache_add(struct sockaddr *, struct sockaddr *, 944 struct tcphdr *, unsigned int, struct socket *, 945 struct mbuf *, u_char *, int, struct tcp_opt_info *); 946 void syn_cache_unreach(const struct sockaddr *, const struct sockaddr *, 947 struct tcphdr *); 948 struct socket *syn_cache_get(struct sockaddr *, struct sockaddr *, 949 struct tcphdr *, struct socket *so, struct mbuf *); 950 void syn_cache_init(void); 951 void syn_cache_insert(struct syn_cache *, struct tcpcb *); 952 struct syn_cache *syn_cache_lookup(const struct sockaddr *, const struct sockaddr *, 953 struct syn_cache_head **); 954 void syn_cache_reset(struct sockaddr *, struct sockaddr *, 955 struct tcphdr *); 956 int syn_cache_respond(struct syn_cache *); 957 void syn_cache_cleanup(struct tcpcb *); 958 959 int tcp_input_checksum(int, struct mbuf *, const struct tcphdr *, int, int, 960 int); 961 #endif 962 963 #endif /* !_NETINET_TCP_VAR_H_ */ 964
Indexes created Fri Sep 26 08:10:20 GMT 2025