1/* $NetBSD: tcp_var.h,v 1.168 2011/10/31 12:52:19 yamt 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 * Kernel variables for tcp. 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_ALLOCSA() lookup to work. 161 */ 162#define TCP_SIG_SPI 0x1000 163#endif /* TCP_SIGNATURE */ 164 165/* 166 * SACK option block. 167 */ 168struct sackblk { 169 tcp_seq left; /* Left edge of sack block. */ 170 tcp_seq right; /* Right edge of sack block. */ 171}; 172 173TAILQ_HEAD(sackhead, sackhole); 174struct sackhole { 175 tcp_seq start; 176 tcp_seq end; 177 tcp_seq rxmit; 178 179 TAILQ_ENTRY(sackhole) sackhole_q; 180}; 181 182/* 183 * Tcp control block, one per tcp; fields: 184 */ 185struct tcpcb { 186 int t_family; /* address family on the wire */ 187 struct ipqehead segq; /* sequencing queue */ 188 int t_segqlen; /* length of the above */ 189 callout_t t_timer[TCPT_NTIMERS];/* tcp timers */ 190 short t_state; /* state of this connection */ 191 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 192 uint32_t t_rxtcur; /* current retransmit value */ 193 short t_dupacks; /* consecutive dup acks recd */ 194 /* 195 * t_partialacks: 196 * <0 not in fast recovery. 197 * ==0 in fast recovery. has not received partial acks 198 * >0 in fast recovery. has received partial acks 199 */ 200 short t_partialacks; /* partials acks during fast rexmit */ 201 u_short t_peermss; /* peer's maximum segment size */ 202 u_short t_ourmss; /* our's maximum segment size */ 203 u_short t_segsz; /* current segment size in use */ 204 char t_force; /* 1 if forcing out a byte */ 205 u_int t_flags; 206#define TF_ACKNOW 0x0001 /* ack peer immediately */ 207#define TF_DELACK 0x0002 /* ack, but try to delay it */ 208#define TF_NODELAY 0x0004 /* don't delay packets to coalesce */ 209#define TF_NOOPT 0x0008 /* don't use tcp options */ 210#define TF_REQ_SCALE 0x0020 /* have/will request window scaling */ 211#define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */ 212#define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */ 213#define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */ 214#define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */ 215#define TF_SYN_REXMT 0x0400 /* rexmit timer fired on SYN */ 216#define TF_WILL_SACK 0x0800 /* try to use SACK */ 217#define TF_REASSEMBLING 0x1000 /* we're busy reassembling */ 218#define TF_DEAD 0x2000 /* dead and to-be-released */ 219#define TF_PMTUD_PEND 0x4000 /* Path MTU Discovery pending */ 220#define TF_ECN_PERMIT 0x10000 /* other side said is ECN-ready */ 221#define TF_ECN_SND_CWR 0x20000 /* ECN CWR in queue */ 222#define TF_ECN_SND_ECE 0x40000 /* ECN ECE in queue */ 223#define TF_SIGNATURE 0x400000 /* require MD5 digests (RFC2385) */ 224 225 226 struct mbuf *t_template; /* skeletal packet for transmit */ 227 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 228 struct in6pcb *t_in6pcb; /* back pointer to internet pcb */ 229 callout_t t_delack_ch; /* delayed ACK callout */ 230/* 231 * The following fields are used as in the protocol specification. 232 * See RFC793, Dec. 1981, page 21. 233 */ 234/* send sequence variables */ 235 tcp_seq snd_una; /* send unacknowledged */ 236 tcp_seq snd_nxt; /* send next */ 237 tcp_seq snd_up; /* send urgent pointer */ 238 tcp_seq snd_wl1; /* window update seg seq number */ 239 tcp_seq snd_wl2; /* window update seg ack number */ 240 tcp_seq iss; /* initial send sequence number */ 241 u_long snd_wnd; /* send window */ 242/* 243 * snd_recover 244 * it's basically same as the "recover" variable in RFC 2852 (NewReno). 245 * when entering fast retransmit, it's set to snd_max. 246 * newreno uses this to detect partial ack. 247 * snd_high 248 * it's basically same as the "send_high" variable in RFC 2852 (NewReno). 249 * on each RTO, it's set to snd_max. 250 * newreno uses this to avoid false fast retransmits. 251 */ 252 tcp_seq snd_recover; 253 tcp_seq snd_high; 254/* receive sequence variables */ 255 u_long rcv_wnd; /* receive window */ 256 tcp_seq rcv_nxt; /* receive next */ 257 tcp_seq rcv_up; /* receive urgent pointer */ 258 tcp_seq irs; /* initial receive sequence number */ 259/* 260 * Additional variables for this implementation. 261 */ 262/* receive variables */ 263 tcp_seq rcv_adv; /* advertised window */ 264 265/* 266 * retransmit variables 267 * 268 * snd_max 269 * the highest sequence number we've ever sent. 270 * used to recognize retransmits. 271 */ 272 tcp_seq snd_max; 273 274/* congestion control (for slow start, source quench, retransmit after loss) */ 275 u_long snd_cwnd; /* congestion-controlled window */ 276 u_long snd_ssthresh; /* snd_cwnd size threshhold for 277 * for slow start exponential to 278 * linear switch 279 */ 280/* auto-sizing variables */ 281 u_int rfbuf_cnt; /* recv buffer autoscaling byte count */ 282 uint32_t rfbuf_ts; /* recv buffer autoscaling timestamp */ 283 284/* 285 * transmit timing stuff. See below for scale of srtt and rttvar. 286 * "Variance" is actually smoothed difference. 287 */ 288 uint32_t t_rcvtime; /* time last segment received */ 289 uint32_t t_rtttime; /* time we started measuring rtt */ 290 tcp_seq t_rtseq; /* sequence number being timed */ 291 int32_t t_srtt; /* smoothed round-trip time */ 292 int32_t t_rttvar; /* variance in round-trip time */ 293 uint32_t t_rttmin; /* minimum rtt allowed */ 294 u_long max_sndwnd; /* largest window peer has offered */ 295 296/* out-of-band data */ 297 char t_oobflags; /* have some */ 298 char t_iobc; /* input character */ 299#define TCPOOB_HAVEDATA 0x01 300#define TCPOOB_HADDATA 0x02 301 short t_softerror; /* possible error not yet reported */ 302 303/* RFC 1323 variables */ 304 u_char snd_scale; /* window scaling for send window */ 305 u_char rcv_scale; /* window scaling for recv window */ 306 u_char request_r_scale; /* pending window scaling */ 307 u_char requested_s_scale; 308 u_int32_t ts_recent; /* timestamp echo data */ 309 u_int32_t ts_recent_age; /* when last updated */ 310 u_int32_t ts_timebase; /* our timebase */ 311 tcp_seq last_ack_sent; 312 313/* RFC 3465 variables */ 314 u_long t_bytes_acked; /* ABC "bytes_acked" parameter */ 315 316/* SACK stuff */ 317#define TCP_SACK_MAX 3 318#define TCPSACK_NONE 0 319#define TCPSACK_HAVED 1 320 u_char rcv_sack_flags; /* SACK flags. */ 321 struct sackblk rcv_dsack_block; /* RX D-SACK block. */ 322 struct ipqehead timeq; /* time sequenced queue. */ 323 struct sackhead snd_holes; /* TX SACK holes. */ 324 int snd_numholes; /* Number of TX SACK holes. */ 325 tcp_seq rcv_lastsack; /* last seq number(+1) sack'd by rcv'r*/ 326 tcp_seq sack_newdata; /* New data xmitted in this recovery 327 episode starts at this seq number*/ 328 tcp_seq snd_fack; /* FACK TCP. Forward-most data held by 329 peer. */ 330 331/* pointer for syn cache entries*/ 332 LIST_HEAD(, syn_cache) t_sc; /* list of entries by this tcb */ 333 334/* prediction of next mbuf when using large window sizes */ 335 struct mbuf *t_lastm; /* last mbuf that data was sent from */ 336 int t_inoff; /* data offset in previous mbuf */ 337 int t_lastoff; /* last data address in mbuf chain */ 338 int t_lastlen; /* last length read from mbuf chain */ 339 340/* Path-MTU discovery blackhole detection */ 341 int t_mtudisc; /* perform mtudisc for this tcb */ 342/* Path-MTU Discovery Information */ 343 u_int t_pmtud_mss_acked; /* MSS acked, lower bound for MTU */ 344 u_int t_pmtud_mtu_sent; /* MTU used, upper bound for MTU */ 345 tcp_seq t_pmtud_th_seq; /* TCP SEQ from ICMP payload */ 346 u_int t_pmtud_nextmtu; /* Advertised Next-Hop MTU from ICMP */ 347 u_short t_pmtud_ip_len; /* IP length from ICMP payload */ 348 u_short t_pmtud_ip_hl; /* IP header length from ICMP payload */ 349 350 uint8_t t_ecn_retries; /* # of ECN setup retries */ 351 352 const struct tcp_congctl *t_congctl; /* per TCB congctl algorithm */ 353 354 /* Keepalive per socket */ 355 u_int t_keepinit; 356 u_int t_keepidle; 357 u_int t_keepintvl; 358 u_int t_keepcnt; 359 u_int t_maxidle; /* t_keepcnt * t_keepintvl */ 360 361 u_int t_msl; /* MSL to use for this connexion */ 362}; 363 364/* 365 * Macros to aid ECN TCP. 366 */ 367#define TCP_ECN_ALLOWED(tp) (tp->t_flags & TF_ECN_PERMIT) 368 369/* 370 * Macros to aid SACK/FACK TCP. 371 */ 372#define TCP_SACK_ENABLED(tp) (tp->t_flags & TF_WILL_SACK) 373#define TCP_FACK_FASTRECOV(tp) \ 374 (TCP_SACK_ENABLED(tp) && \ 375 (SEQ_GT(tp->snd_fack, tp->snd_una + tcprexmtthresh * tp->t_segsz))) 376 377#ifdef _KERNEL 378/* 379 * TCP reassembly queue locks. 380 */ 381static __inline int tcp_reass_lock_try (struct tcpcb *) 382 __unused; 383static __inline void tcp_reass_unlock (struct tcpcb *) 384 __unused; 385 386static __inline int 387tcp_reass_lock_try(struct tcpcb *tp) 388{ 389 int s; 390 391 /* 392 * Use splvm() -- we're blocking things that would cause 393 * mbuf allocation. 394 */ 395 s = splvm(); 396 if (tp->t_flags & TF_REASSEMBLING) { 397 splx(s); 398 return (0); 399 } 400 tp->t_flags |= TF_REASSEMBLING; 401 splx(s); 402 return (1); 403} 404 405static __inline void 406tcp_reass_unlock(struct tcpcb *tp) 407{ 408 int s; 409 410 s = splvm(); 411 KASSERT((tp->t_flags & TF_REASSEMBLING) != 0); 412 tp->t_flags &= ~TF_REASSEMBLING; 413 splx(s); 414} 415 416#ifdef DIAGNOSTIC 417#define TCP_REASS_LOCK(tp) \ 418do { \ 419 if (tcp_reass_lock_try(tp) == 0) { \ 420 printf("%s:%d: tcpcb %p reass already locked\n", \ 421 __FILE__, __LINE__, tp); \ 422 panic("tcp_reass_lock"); \ 423 } \ 424} while (/*CONSTCOND*/ 0) 425#define TCP_REASS_LOCK_CHECK(tp) \ 426do { \ 427 if (((tp)->t_flags & TF_REASSEMBLING) == 0) { \ 428 printf("%s:%d: tcpcb %p reass lock not held\n", \ 429 __FILE__, __LINE__, tp); \ 430 panic("tcp reass lock check"); \ 431 } \ 432} while (/*CONSTCOND*/ 0) 433#else 434#define TCP_REASS_LOCK(tp) (void) tcp_reass_lock_try((tp)) 435#define TCP_REASS_LOCK_CHECK(tp) /* nothing */ 436#endif 437 438#define TCP_REASS_UNLOCK(tp) tcp_reass_unlock((tp)) 439#endif /* _KERNEL */ 440 441/* 442 * Queue for delayed ACK processing. 443 */ 444#ifdef _KERNEL 445extern int tcp_delack_ticks; 446void tcp_delack(void *); 447 448#define TCP_RESTART_DELACK(tp) \ 449 callout_reset(&(tp)->t_delack_ch, tcp_delack_ticks, \ 450 tcp_delack, tp) 451 452#define TCP_SET_DELACK(tp) \ 453do { \ 454 if (((tp)->t_flags & TF_DELACK) == 0) { \ 455 (tp)->t_flags |= TF_DELACK; \ 456 TCP_RESTART_DELACK(tp); \ 457 } \ 458} while (/*CONSTCOND*/0) 459 460#define TCP_CLEAR_DELACK(tp) \ 461do { \ 462 if ((tp)->t_flags & TF_DELACK) { \ 463 (tp)->t_flags &= ~TF_DELACK; \ 464 callout_stop(&(tp)->t_delack_ch); \ 465 } \ 466} while (/*CONSTCOND*/0) 467#endif /* _KERNEL */ 468 469/* 470 * Compute the current timestamp for a connection. 471 */ 472#define TCP_TIMESTAMP(tp) (tcp_now - (tp)->ts_timebase) 473 474/* 475 * Handy way of passing around TCP option info. 476 */ 477struct tcp_opt_info { 478 int ts_present; 479 u_int32_t ts_val; 480 u_int32_t ts_ecr; 481 u_int16_t maxseg; 482}; 483 484#define TOF_SIGNATURE 0x0040 /* signature option present */ 485#define TOF_SIGLEN 0x0080 /* sigature length valid (RFC2385) */ 486 487/* 488 * Data for the TCP compressed state engine. 489 */ 490union syn_cache_sa { 491 struct sockaddr sa; 492 struct sockaddr_in sin; 493#if 1 /*def INET6*/ 494 struct sockaddr_in6 sin6; 495#endif 496}; 497 498struct syn_cache { 499 TAILQ_ENTRY(syn_cache) sc_bucketq; /* link on bucket list */ 500 callout_t sc_timer; /* rexmt timer */ 501 struct route sc_route; 502 long sc_win; /* advertised window */ 503 int sc_bucketidx; /* our bucket index */ 504 u_int32_t sc_hash; 505 u_int32_t sc_timestamp; /* timestamp from SYN */ 506 u_int32_t sc_timebase; /* our local timebase */ 507 union syn_cache_sa sc_src; 508 union syn_cache_sa sc_dst; 509 tcp_seq sc_irs; 510 tcp_seq sc_iss; 511 u_int sc_rxtcur; /* current rxt timeout */ 512 u_int sc_rxttot; /* total time spend on queues */ 513 u_short sc_rxtshift; /* for computing backoff */ 514 u_short sc_flags; 515 516#define SCF_UNREACH 0x0001 /* we've had an unreach error */ 517#define SCF_TIMESTAMP 0x0002 /* peer will do timestamps */ 518#define SCF_DEAD 0x0004 /* this entry to be released */ 519#define SCF_SACK_PERMIT 0x0008 /* peer will do SACK */ 520#define SCF_ECN_PERMIT 0x0010 /* peer will do ECN */ 521#define SCF_SIGNATURE 0x40 /* send MD5 digests */ 522 523 struct mbuf *sc_ipopts; /* IP options */ 524 u_int16_t sc_peermaxseg; 525 u_int16_t sc_ourmaxseg; 526 u_int8_t sc_request_r_scale : 4, 527 sc_requested_s_scale : 4; 528 529 struct tcpcb *sc_tp; /* tcb for listening socket */ 530 LIST_ENTRY(syn_cache) sc_tpq; /* list of entries by same tp */ 531}; 532 533struct syn_cache_head { 534 TAILQ_HEAD(, syn_cache) sch_bucket; /* bucket entries */ 535 u_short sch_length; /* # entries in bucket */ 536}; 537 538#define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 539#ifdef INET6 540#define in6totcpcb(ip) ((struct tcpcb *)(ip)->in6p_ppcb) 541#endif 542#ifndef INET6 543#define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 544#else 545#define sototcpcb(so) (((so)->so_proto->pr_domain->dom_family == AF_INET) \ 546 ? intotcpcb(sotoinpcb(so)) \ 547 : in6totcpcb(sotoin6pcb(so))) 548#endif 549 550/* 551 * See RFC2988 for a discussion of RTO calculation; comments assume 552 * familiarity with that document. 553 * 554 * The smoothed round-trip time and estimated variance are stored as 555 * fixed point numbers. Historically, srtt was scaled by 556 * TCP_RTT_SHIFT bits, and rttvar by TCP_RTTVAR_SHIFT bits. Because 557 * the values coincide with the alpha and beta parameters suggested 558 * for RTO calculation (1/8 for srtt, 1/4 for rttvar), the combination 559 * of computing 1/8 of the new value and transforming it to the 560 * fixed-point representation required zero instructions. However, 561 * the storage representations no longer coincide with the alpha/beta 562 * shifts; instead, more fractional bits are present. 563 * 564 * The storage representation of srtt is 1/32 slow ticks, or 1/64 s. 565 * (The assumption that a slow tick is 500 ms should not be present in 566 * the code.) 567 * 568 * The storage representation of rttvar is 1/16 slow ticks, or 1/32 s. 569 * There may be some confusion about this in the code. 570 * 571 * For historical reasons, these scales are also used in smoothing the 572 * average (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 573 * This results in alpha of 0.125 and beta of 0.25, following RFC2988 574 * section 2.3 575 * 576 * XXX Change SHIFT values to LGWEIGHT and REP_SHIFT, and adjust 577 * the code to use the correct ones. 578 */ 579#define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ 580#define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */ 581 582/* 583 * Compute TCP retransmission timer, following RFC2988. 584 * This macro returns a value in slow timeout ticks. 585 * 586 * Section 2.2 requires that the RTO value be 587 * srtt + max(G, 4*RTTVAR) 588 * where G is the clock granularity. 589 * 590 * This comment has not necessarily been updated for the new storage 591 * representation: 592 * 593 * Because of the way we do the smoothing, srtt and rttvar 594 * will each average +1/2 tick of bias. When we compute 595 * the retransmit timer, we want 1/2 tick of rounding and 596 * 1 extra tick because of +-1/2 tick uncertainty in the 597 * firing of the timer. The bias will give us exactly the 598 * 1.5 tick we need. But, because the bias is 599 * statistical, we have to test that we don't drop below 600 * the minimum feasible timer (which is 2 ticks). 601 * This macro assumes that the value of 1<<TCP_RTTVAR_SHIFT 602 * is the same as the multiplier for rttvar. 603 * 604 * This macro appears to be wrong; it should be checking rttvar*4 in 605 * ticks and making sure we use 1 instead if rttvar*4 rounds to 0. It 606 * appears to be treating srtt as being in the old storage 607 * representation, resulting in a factor of 4 extra. 608 */ 609#define TCP_REXMTVAL(tp) \ 610 ((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) >> 2) 611 612/* 613 * Compute the initial window for slow start. 614 */ 615#define TCP_INITIAL_WINDOW(iw, segsz) \ 616 (((iw) == 0) ? (min(4 * (segsz), max(2 * (segsz), 4380))) : \ 617 ((segsz) * (iw))) 618 619/* 620 * TCP statistics. 621 * Each counter is an unsigned 64-bit value. 622 * 623 * Many of these should be kept per connection, but that's inconvenient 624 * at the moment. 625 */ 626#define TCP_STAT_CONNATTEMPT 0 /* connections initiated */ 627#define TCP_STAT_ACCEPTS 1 /* connections accepted */ 628#define TCP_STAT_CONNECTS 2 /* connections established */ 629#define TCP_STAT_DROPS 3 /* connections dropped */ 630#define TCP_STAT_CONNDROPS 4 /* embryonic connections dropped */ 631#define TCP_STAT_CLOSED 5 /* conn. closed (includes drops) */ 632#define TCP_STAT_SEGSTIMED 6 /* segs where we tried to get rtt */ 633#define TCP_STAT_RTTUPDATED 7 /* times we succeeded */ 634#define TCP_STAT_DELACK 8 /* delayed ACKs sent */ 635#define TCP_STAT_TIMEOUTDROP 9 /* conn. dropped in rxmt timeout */ 636#define TCP_STAT_REXMTTIMEO 10 /* retransmit timeouts */ 637#define TCP_STAT_PERSISTTIMEO 11 /* persist timeouts */ 638#define TCP_STAT_KEEPTIMEO 12 /* keepalive timeouts */ 639#define TCP_STAT_KEEPPROBE 13 /* keepalive probes sent */ 640#define TCP_STAT_KEEPDROPS 14 /* connections dropped in keepalive */ 641#define TCP_STAT_PERSISTDROPS 15 /* connections dropped in persist */ 642#define TCP_STAT_CONNSDRAINED 16 /* connections drained due to memory 643 shortage */ 644#define TCP_STAT_PMTUBLACKHOLE 17 /* PMTUD blackhole detected */ 645#define TCP_STAT_SNDTOTAL 18 /* total packets sent */ 646#define TCP_STAT_SNDPACK 19 /* data packlets sent */ 647#define TCP_STAT_SNDBYTE 20 /* data bytes sent */ 648#define TCP_STAT_SNDREXMITPACK 21 /* data packets retransmitted */ 649#define TCP_STAT_SNDREXMITBYTE 22 /* data bytes retransmitted */ 650#define TCP_STAT_SNDACKS 23 /* ACK-only packets sent */ 651#define TCP_STAT_SNDPROBE 24 /* window probes sent */ 652#define TCP_STAT_SNDURG 25 /* packets sent with URG only */ 653#define TCP_STAT_SNDWINUP 26 /* window update-only packets sent */ 654#define TCP_STAT_SNDCTRL 27 /* control (SYN|FIN|RST) packets sent */ 655#define TCP_STAT_RCVTOTAL 28 /* total packets received */ 656#define TCP_STAT_RCVPACK 29 /* packets received in sequence */ 657#define TCP_STAT_RCVBYTE 30 /* bytes received in sequence */ 658#define TCP_STAT_RCVBADSUM 31 /* packets received with cksum errs */ 659#define TCP_STAT_RCVBADOFF 32 /* packets received with bad offset */ 660#define TCP_STAT_RCVMEMDROP 33 /* packets dropped for lack of memory */ 661#define TCP_STAT_RCVSHORT 34 /* packets received too short */ 662#define TCP_STAT_RCVDUPPACK 35 /* duplicate-only packets received */ 663#define TCP_STAT_RCVDUPBYTE 36 /* duplicate-only bytes received */ 664#define TCP_STAT_RCVPARTDUPPACK 37 /* packets with some duplicate data */ 665#define TCP_STAT_RCVPARTDUPBYTE 38 /* dup. bytes in part-dup. packets */ 666#define TCP_STAT_RCVOOPACK 39 /* out-of-order packets received */ 667#define TCP_STAT_RCVOOBYTE 40 /* out-of-order bytes received */ 668#define TCP_STAT_RCVPACKAFTERWIN 41 /* packets with data after window */ 669#define TCP_STAT_RCVBYTEAFTERWIN 42 /* bytes received after window */ 670#define TCP_STAT_RCVAFTERCLOSE 43 /* packets received after "close" */ 671#define TCP_STAT_RCVWINPROBE 44 /* rcvd window probe packets */ 672#define TCP_STAT_RCVDUPACK 45 /* rcvd duplicate ACKs */ 673#define TCP_STAT_RCVACKTOOMUCH 46 /* rcvd ACKs for unsent data */ 674#define TCP_STAT_RCVACKPACK 47 /* rcvd ACK packets */ 675#define TCP_STAT_RCVACKBYTE 48 /* bytes ACKed by rcvd ACKs */ 676#define TCP_STAT_RCVWINUPD 49 /* rcvd window update packets */ 677#define TCP_STAT_PAWSDROP 50 /* segments dropped due to PAWS */ 678#define TCP_STAT_PREDACK 51 /* times hdr predict OK for ACKs */ 679#define TCP_STAT_PREDDAT 52 /* times hdr predict OK for data pkts */ 680#define TCP_STAT_PCBHASHMISS 53 /* input packets missing PCB hash */ 681#define TCP_STAT_NOPORT 54 /* no socket on port */ 682#define TCP_STAT_BADSYN 55 /* received ACK for which we have 683 no SYN in compressed state */ 684#define TCP_STAT_DELAYED_FREE 56 /* delayed pool_put() of tcpcb */ 685#define TCP_STAT_SC_ADDED 57 /* # of sc entries added */ 686#define TCP_STAT_SC_COMPLETED 58 /* # of sc connections completed */ 687#define TCP_STAT_SC_TIMED_OUT 59 /* # of sc entries timed out */ 688#define TCP_STAT_SC_OVERFLOWED 60 /* # of sc drops due to overflow */ 689#define TCP_STAT_SC_RESET 61 /* # of sc drops due to RST */ 690#define TCP_STAT_SC_UNREACH 62 /* # of sc drops due to ICMP unreach */ 691#define TCP_STAT_SC_BUCKETOVERFLOW 63 /* # of sc drops due to bucket ovflow */ 692#define TCP_STAT_SC_ABORTED 64 /* # of sc entries aborted (no mem) */ 693#define TCP_STAT_SC_DUPESYN 65 /* # of duplicate SYNs received */ 694#define TCP_STAT_SC_DROPPED 66 /* # of SYNs dropped (no route/mem) */ 695#define TCP_STAT_SC_COLLISIONS 67 /* # of sc hash collisions */ 696#define TCP_STAT_SC_RETRANSMITTED 68 /* # of sc retransmissions */ 697#define TCP_STAT_SC_DELAYED_FREE 69 /* # of delayed pool_put()s */ 698#define TCP_STAT_SELFQUENCH 70 /* # of ENOBUFS we get on output */ 699#define TCP_STAT_BADSIG 71 /* # of drops due to bad signature */ 700#define TCP_STAT_GOODSIG 72 /* # of packets with good signature */ 701#define TCP_STAT_ECN_SHS 73 /* # of successful ECN handshakes */ 702#define TCP_STAT_ECN_CE 74 /* # of packets with CE bit */ 703#define TCP_STAT_ECN_ECT 75 /* # of packets with ECT(0) bit */ 704 705#define TCP_NSTATS 76 706 707/* 708 * Names for TCP sysctl objects. 709 */ 710#define TCPCTL_RFC1323 1 /* RFC1323 timestamps/scaling */ 711#define TCPCTL_SENDSPACE 2 /* default send buffer */ 712#define TCPCTL_RECVSPACE 3 /* default recv buffer */ 713#define TCPCTL_MSSDFLT 4 /* default seg size */ 714#define TCPCTL_SYN_CACHE_LIMIT 5 /* max size of comp. state engine */ 715#define TCPCTL_SYN_BUCKET_LIMIT 6 /* max size of hash bucket */ 716#if 0 /*obsoleted*/ 717#define TCPCTL_SYN_CACHE_INTER 7 /* interval of comp. state timer */ 718#endif 719#define TCPCTL_INIT_WIN 8 /* initial window */ 720#define TCPCTL_MSS_IFMTU 9 /* mss from interface, not in_maxmtu */ 721#define TCPCTL_SACK 10 /* RFC2018 selective acknowledgement */ 722#define TCPCTL_WSCALE 11 /* RFC1323 window scaling */ 723#define TCPCTL_TSTAMP 12 /* RFC1323 timestamps */ 724#define TCPCTL_COMPAT_42 13 /* 4.2BSD TCP bug work-arounds */ 725#define TCPCTL_CWM 14 /* Congestion Window Monitoring */ 726#define TCPCTL_CWM_BURSTSIZE 15 /* burst size allowed by CWM */ 727#define TCPCTL_ACK_ON_PUSH 16 /* ACK immediately on PUSH */ 728#define TCPCTL_KEEPIDLE 17 /* keepalive idle time */ 729#define TCPCTL_KEEPINTVL 18 /* keepalive probe interval */ 730#define TCPCTL_KEEPCNT 19 /* keepalive count */ 731#define TCPCTL_SLOWHZ 20 /* PR_SLOWHZ (read-only) */ 732#define TCPCTL_NEWRENO 21 /* NewReno Congestion Control */ 733#define TCPCTL_LOG_REFUSED 22 /* Log refused connections */ 734#if 0 /*obsoleted*/ 735#define TCPCTL_RSTRATELIMIT 23 /* RST rate limit */ 736#endif 737#define TCPCTL_RSTPPSLIMIT 24 /* RST pps limit */ 738#define TCPCTL_DELACK_TICKS 25 /* # ticks to delay ACK */ 739#define TCPCTL_INIT_WIN_LOCAL 26 /* initial window for local nets */ 740#define TCPCTL_IDENT 27 /* rfc 931 identd */ 741#define TCPCTL_ACKDROPRATELIMIT 28 /* SYN/RST -> ACK rate limit */ 742#define TCPCTL_LOOPBACKCKSUM 29 /* do TCP checksum on loopback */ 743#define TCPCTL_STATS 30 /* TCP statistics */ 744#define TCPCTL_DEBUG 31 /* TCP debug sockets */ 745#define TCPCTL_DEBX 32 /* # of tcp debug sockets */ 746#define TCPCTL_DROP 33 /* drop tcp connection */ 747#define TCPCTL_MSL 34 /* Max Segment Life */ 748#define TCPCTL_MAXID 35 749 750#define TCPCTL_NAMES { \ 751 { 0, 0 }, \ 752 { "rfc1323", CTLTYPE_INT }, \ 753 { "sendspace", CTLTYPE_INT }, \ 754 { "recvspace", CTLTYPE_INT }, \ 755 { "mssdflt", CTLTYPE_INT }, \ 756 { "syn_cache_limit", CTLTYPE_INT }, \ 757 { "syn_bucket_limit", CTLTYPE_INT }, \ 758 { 0, 0 },\ 759 { "init_win", CTLTYPE_INT }, \ 760 { "mss_ifmtu", CTLTYPE_INT }, \ 761 { "sack", CTLTYPE_INT }, \ 762 { "win_scale", CTLTYPE_INT }, \ 763 { "timestamps", CTLTYPE_INT }, \ 764 { "compat_42", CTLTYPE_INT }, \ 765 { "cwm", CTLTYPE_INT }, \ 766 { "cwm_burstsize", CTLTYPE_INT }, \ 767 { "ack_on_push", CTLTYPE_INT }, \ 768 { "keepidle", CTLTYPE_INT }, \ 769 { "keepintvl", CTLTYPE_INT }, \ 770 { "keepcnt", CTLTYPE_INT }, \ 771 { "slowhz", CTLTYPE_INT }, \ 772 { 0, 0 }, \ 773 { "log_refused",CTLTYPE_INT }, \ 774 { 0, 0 }, \ 775 { "rstppslimit", CTLTYPE_INT }, \ 776 { "delack_ticks", CTLTYPE_INT }, \ 777 { "init_win_local", CTLTYPE_INT }, \ 778 { "ident", CTLTYPE_STRUCT }, \ 779 { "ackdropppslimit", CTLTYPE_INT }, \ 780 { "do_loopback_cksum", CTLTYPE_INT }, \ 781 { "stats", CTLTYPE_STRUCT }, \ 782 { "debug", CTLTYPE_STRUCT }, \ 783 { "debx", CTLTYPE_INT }, \ 784 { "drop", CTLTYPE_STRUCT }, \ 785 { "msl", CTLTYPE_INT }, \ 786} 787 788#ifdef _KERNEL 789extern struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 790extern u_int32_t tcp_now; /* for RFC 1323 timestamps */ 791extern int tcp_do_rfc1323; /* enabled/disabled? */ 792extern int tcp_do_sack; /* SACK enabled/disabled? */ 793extern int tcp_do_win_scale; /* RFC1323 window scaling enabled/disabled? */ 794extern int tcp_do_timestamps; /* RFC1323 timestamps enabled/disabled? */ 795extern int tcp_mssdflt; /* default seg size */ 796extern int tcp_minmss; /* minimal seg size */ 797extern int tcp_msl; /* max segment life */ 798extern int tcp_init_win; /* initial window */ 799extern int tcp_init_win_local; /* initial window for local nets */ 800extern int tcp_mss_ifmtu; /* take MSS from interface, not in_maxmtu */ 801extern int tcp_compat_42; /* work around ancient broken TCP peers */ 802extern int tcp_cwm; /* enable Congestion Window Monitoring */ 803extern int tcp_cwm_burstsize; /* burst size allowed by CWM */ 804extern int tcp_ack_on_push; /* ACK immediately on PUSH */ 805extern int tcp_syn_cache_limit; /* max entries for compressed state engine */ 806extern int tcp_syn_bucket_limit;/* max entries per hash bucket */ 807extern int tcp_log_refused; /* log refused connections */ 808extern int tcp_do_ecn; /* TCP ECN enabled/disabled? */ 809extern int tcp_ecn_maxretries; /* Max ECN setup retries */ 810extern int tcp_do_rfc1948; /* ISS by cryptographic hash */ 811extern int tcp_sack_tp_maxholes; /* Max holes per connection. */ 812extern int tcp_sack_globalmaxholes; /* Max holes per system. */ 813extern int tcp_sack_globalholes; /* Number of holes present. */ 814extern int tcp_do_abc; /* RFC3465 ABC enabled/disabled? */ 815extern int tcp_abc_aggressive; /* 1: L=2*SMSS 0: L=1*SMSS */ 816 817extern int tcp_msl_enable; /* enable TIME_WAIT truncation */ 818extern int tcp_msl_loop; /* MSL for loopback */ 819extern int tcp_msl_local; /* MSL for 'local' */ 820extern int tcp_msl_remote; /* MSL otherwise */ 821extern int tcp_msl_remote_threshold; /* RTT threshold */ 822extern int tcp_rttlocal; /* Use RTT to decide who's 'local' */ 823extern int tcp4_vtw_enable; 824extern int tcp6_vtw_enable; 825extern int tcp_vtw_was_enabled; 826extern int tcp_vtw_entries; 827 828extern int tcp_rst_ppslim; 829extern int tcp_ackdrop_ppslim; 830 831extern int tcp_syn_cache_size; 832extern struct syn_cache_head tcp_syn_cache[]; 833extern u_long syn_cache_count; 834 835#ifdef MBUFTRACE 836extern struct mowner tcp_rx_mowner; 837extern struct mowner tcp_tx_mowner; 838extern struct mowner tcp_reass_mowner; 839extern struct mowner tcp_sock_mowner; 840extern struct mowner tcp_sock_rx_mowner; 841extern struct mowner tcp_sock_tx_mowner; 842extern struct mowner tcp_mowner; 843#endif 844 845extern int tcp_do_autorcvbuf; 846extern int tcp_autorcvbuf_inc; 847extern int tcp_autorcvbuf_max; 848extern int tcp_do_autosndbuf; 849extern int tcp_autosndbuf_inc; 850extern int tcp_autosndbuf_max; 851 852 853#define TCPCTL_VARIABLES { \ 854 { 0 }, \ 855 { 1, 0, &tcp_do_rfc1323 }, \ 856 { 1, 0, &tcp_sendspace }, \ 857 { 1, 0, &tcp_recvspace }, \ 858 { 1, 0, &tcp_mssdflt }, \ 859 { 1, 0, &tcp_syn_cache_limit }, \ 860 { 1, 0, &tcp_syn_bucket_limit }, \ 861 { 0 }, \ 862 { 1, 0, &tcp_init_win }, \ 863 { 1, 0, &tcp_mss_ifmtu }, \ 864 { 1, 0, &tcp_do_sack }, \ 865 { 1, 0, &tcp_do_win_scale }, \ 866 { 1, 0, &tcp_do_timestamps }, \ 867 { 1, 0, &tcp_compat_42 }, \ 868 { 1, 0, &tcp_cwm }, \ 869 { 1, 0, &tcp_cwm_burstsize }, \ 870 { 1, 0, &tcp_ack_on_push }, \ 871 { 1, 0, &tcp_keepidle }, \ 872 { 1, 0, &tcp_keepintvl }, \ 873 { 1, 0, &tcp_keepcnt }, \ 874 { 1, 1, 0, PR_SLOWHZ }, \ 875 { 0 }, \ 876 { 1, 0, &tcp_log_refused }, \ 877 { 0 }, \ 878 { 1, 0, &tcp_rst_ppslim }, \ 879 { 1, 0, &tcp_delack_ticks }, \ 880 { 1, 0, &tcp_init_win_local }, \ 881 { 1, 0, &tcp_ackdrop_ppslim }, \ 882} 883 884struct secasvar; 885 886int tcp_attach(struct socket *); 887void tcp_canceltimers(struct tcpcb *); 888struct tcpcb * 889 tcp_close(struct tcpcb *); 890int tcp_isdead(struct tcpcb *); 891#ifdef INET6 892void *tcp6_ctlinput(int, const struct sockaddr *, void *); 893#endif 894void *tcp_ctlinput(int, const struct sockaddr *, void *); 895int tcp_ctloutput(int, struct socket *, struct sockopt *); 896struct tcpcb * 897 tcp_disconnect(struct tcpcb *); 898struct tcpcb * 899 tcp_drop(struct tcpcb *, int); 900#ifdef TCP_SIGNATURE 901int tcp_signature_apply(void *, void *, u_int); 902struct secasvar *tcp_signature_getsav(struct mbuf *, struct tcphdr *); 903int tcp_signature(struct mbuf *, struct tcphdr *, int, struct secasvar *, 904 char *); 905#endif 906void tcp_drain(void); 907void tcp_drainstub(void); 908void tcp_established(struct tcpcb *); 909void tcp_init(void); 910#ifdef INET6 911int tcp6_input(struct mbuf **, int *, int); 912#endif 913void tcp_input(struct mbuf *, ...); 914u_int tcp_hdrsz(struct tcpcb *); 915u_long tcp_mss_to_advertise(const struct ifnet *, int); 916void tcp_mss_from_peer(struct tcpcb *, int); 917void tcp_tcpcb_template(void); 918struct tcpcb * 919 tcp_newtcpcb(int, void *); 920void tcp_notify(struct inpcb *, int); 921#ifdef INET6 922void tcp6_notify(struct in6pcb *, int); 923#endif 924u_int tcp_optlen(struct tcpcb *); 925int tcp_output(struct tcpcb *); 926void tcp_pulloutofband(struct socket *, 927 struct tcphdr *, struct mbuf *, int); 928void tcp_quench(struct inpcb *, int); 929#ifdef INET6 930void tcp6_quench(struct in6pcb *, int); 931#endif 932void tcp_mtudisc(struct inpcb *, int); 933 934void tcpipqent_init(void); 935struct ipqent *tcpipqent_alloc(void); 936void tcpipqent_free(struct ipqent *); 937 938int tcp_respond(struct tcpcb *, struct mbuf *, struct mbuf *, 939 struct tcphdr *, tcp_seq, tcp_seq, int); 940void tcp_rmx_rtt(struct tcpcb *); 941void tcp_setpersist(struct tcpcb *); 942#ifdef TCP_SIGNATURE 943int tcp_signature_compute(struct mbuf *, struct tcphdr *, int, int, 944 int, u_char *, u_int); 945#endif 946void tcp_slowtimo(void); 947void tcp_fasttimo(void); 948struct mbuf * 949 tcp_template(struct tcpcb *); 950void tcp_trace(short, short, struct tcpcb *, struct mbuf *, int); 951struct tcpcb * 952 tcp_usrclosed(struct tcpcb *); 953void tcp_usrreq_init(void); 954int tcp_usrreq(struct socket *, 955 int, struct mbuf *, struct mbuf *, struct mbuf *, struct lwp *); 956void tcp_xmit_timer(struct tcpcb *, uint32_t); 957tcp_seq tcp_new_iss(struct tcpcb *, tcp_seq); 958tcp_seq tcp_new_iss1(void *, void *, u_int16_t, u_int16_t, size_t, 959 tcp_seq); 960 961void tcp_sack_init(void); 962void tcp_new_dsack(struct tcpcb *, tcp_seq, u_int32_t); 963void tcp_sack_option(struct tcpcb *, const struct tcphdr *, 964 const u_char *, int); 965void tcp_del_sackholes(struct tcpcb *, const struct tcphdr *); 966void tcp_free_sackholes(struct tcpcb *); 967void tcp_sack_adjust(struct tcpcb *tp); 968struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt); 969void tcp_sack_newack(struct tcpcb *, const struct tcphdr *); 970int tcp_sack_numblks(const struct tcpcb *); 971#define TCP_SACK_OPTLEN(nblks) ((nblks) * 8 + 2 + 2) 972 973void tcp_statinc(u_int); 974void tcp_statadd(u_int, uint64_t); 975 976int syn_cache_add(struct sockaddr *, struct sockaddr *, 977 struct tcphdr *, unsigned int, struct socket *, 978 struct mbuf *, u_char *, int, struct tcp_opt_info *); 979void syn_cache_unreach(const struct sockaddr *, const struct sockaddr *, 980 struct tcphdr *); 981struct socket *syn_cache_get(struct sockaddr *, struct sockaddr *, 982 struct tcphdr *, unsigned int, unsigned int, 983 struct socket *so, struct mbuf *); 984void syn_cache_init(void); 985void syn_cache_insert(struct syn_cache *, struct tcpcb *); 986struct syn_cache *syn_cache_lookup(const struct sockaddr *, const struct sockaddr *, 987 struct syn_cache_head **); 988void syn_cache_reset(struct sockaddr *, struct sockaddr *, 989 struct tcphdr *); 990int syn_cache_respond(struct syn_cache *, struct mbuf *); 991void syn_cache_timer(void *); 992void syn_cache_cleanup(struct tcpcb *); 993 994int tcp_input_checksum(int, struct mbuf *, const struct tcphdr *, int, int, 995 int); 996#endif 997 998#endif /* !_NETINET_TCP_VAR_H_ */ 999