tcp_var.h revision 1.190
1 /* $NetBSD: tcp_var.h,v 1.190 2018/12/27 16:59:17 maxv 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 } __packed; 172 #define ti_x1 ti_i.ih_x1 173 #define ti_pr ti_i.ih_pr 174 #define ti_len ti_i.ih_len 175 #define ti_src ti_i.ih_src 176 #define ti_dst ti_i.ih_dst 177 #define ti_sport ti_t.th_sport 178 #define ti_dport ti_t.th_dport 179 #define ti_seq ti_t.th_seq 180 #define ti_ack ti_t.th_ack 181 #define ti_x2 ti_t.th_x2 182 #define ti_off ti_t.th_off 183 #define ti_flags ti_t.th_flags 184 #define ti_win ti_t.th_win 185 #define ti_sum ti_t.th_sum 186 #define ti_urp ti_t.th_urp 187 188 /* 189 * SACK option block. 190 */ 191 struct sackblk { 192 tcp_seq left; /* Left edge of sack block. */ 193 tcp_seq right; /* Right edge of sack block. */ 194 }; 195 196 TAILQ_HEAD(sackhead, sackhole); 197 struct sackhole { 198 tcp_seq start; 199 tcp_seq end; 200 tcp_seq rxmit; 201 202 TAILQ_ENTRY(sackhole) sackhole_q; 203 }; 204 205 /* 206 * Tcp control block, one per tcp; fields: 207 */ 208 struct tcpcb { 209 int t_family; /* address family on the wire */ 210 struct ipqehead segq; /* sequencing queue */ 211 int t_segqlen; /* length of the above */ 212 callout_t t_timer[TCPT_NTIMERS];/* tcp timers */ 213 short t_state; /* state of this connection */ 214 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 215 uint32_t t_rxtcur; /* current retransmit value */ 216 short t_dupacks; /* consecutive dup acks recd */ 217 /* 218 * t_partialacks: 219 * <0 not in fast recovery. 220 * ==0 in fast recovery. has not received partial acks 221 * >0 in fast recovery. has received partial acks 222 */ 223 short t_partialacks; /* partials acks during fast rexmit */ 224 u_short t_peermss; /* peer's maximum segment size */ 225 u_short t_ourmss; /* our's maximum segment size */ 226 u_short t_segsz; /* current segment size in use */ 227 char t_force; /* 1 if forcing out a byte */ 228 u_int t_flags; 229 #define TF_ACKNOW 0x0001 /* ack peer immediately */ 230 #define TF_DELACK 0x0002 /* ack, but try to delay it */ 231 #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */ 232 #define TF_NOOPT 0x0008 /* don't use tcp options */ 233 #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */ 234 #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */ 235 #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */ 236 #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */ 237 #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */ 238 #define TF_SYN_REXMT 0x0400 /* rexmit timer fired on SYN */ 239 #define TF_WILL_SACK 0x0800 /* try to use SACK */ 240 #define TF_REASSEMBLING 0x1000 /* we're busy reassembling */ 241 #define TF_DEAD 0x2000 /* dead and to-be-released */ 242 #define TF_PMTUD_PEND 0x4000 /* Path MTU Discovery pending */ 243 #define TF_ECN_PERMIT 0x10000 /* other side said is ECN-ready */ 244 #define TF_ECN_SND_CWR 0x20000 /* ECN CWR in queue */ 245 #define TF_ECN_SND_ECE 0x40000 /* ECN ECE in queue */ 246 #define TF_SIGNATURE 0x400000 /* require MD5 digests (RFC2385) */ 247 248 249 struct mbuf *t_template; /* skeletal packet for transmit */ 250 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 251 struct in6pcb *t_in6pcb; /* back pointer to internet pcb */ 252 callout_t t_delack_ch; /* delayed ACK callout */ 253 /* 254 * The following fields are used as in the protocol specification. 255 * See RFC793, Dec. 1981, page 21. 256 */ 257 /* send sequence variables */ 258 tcp_seq snd_una; /* send unacknowledged */ 259 tcp_seq snd_nxt; /* send next */ 260 tcp_seq snd_up; /* send urgent pointer */ 261 tcp_seq snd_wl1; /* window update seg seq number */ 262 tcp_seq snd_wl2; /* window update seg ack number */ 263 tcp_seq iss; /* initial send sequence number */ 264 u_long snd_wnd; /* send window */ 265 /* 266 * snd_recover 267 * it's basically same as the "recover" variable in RFC 2852 (NewReno). 268 * when entering fast retransmit, it's set to snd_max. 269 * newreno uses this to detect partial ack. 270 * snd_high 271 * it's basically same as the "send_high" variable in RFC 2852 (NewReno). 272 * on each RTO, it's set to snd_max. 273 * newreno uses this to avoid false fast retransmits. 274 */ 275 tcp_seq snd_recover; 276 tcp_seq snd_high; 277 /* receive sequence variables */ 278 u_long rcv_wnd; /* receive window */ 279 tcp_seq rcv_nxt; /* receive next */ 280 tcp_seq rcv_up; /* receive urgent pointer */ 281 tcp_seq irs; /* initial receive sequence number */ 282 /* 283 * Additional variables for this implementation. 284 */ 285 /* receive variables */ 286 tcp_seq rcv_adv; /* advertised window */ 287 288 /* 289 * retransmit variables 290 * 291 * snd_max 292 * the highest sequence number we've ever sent. 293 * used to recognize retransmits. 294 */ 295 tcp_seq snd_max; 296 297 /* congestion control (for slow start, source quench, retransmit after loss) */ 298 u_long snd_cwnd; /* congestion-controlled window */ 299 u_long snd_ssthresh; /* snd_cwnd size threshhold for 300 * for slow start exponential to 301 * linear switch 302 */ 303 /* auto-sizing variables */ 304 u_int rfbuf_cnt; /* recv buffer autoscaling byte count */ 305 uint32_t rfbuf_ts; /* recv buffer autoscaling timestamp */ 306 307 /* 308 * transmit timing stuff. See below for scale of srtt and rttvar. 309 * "Variance" is actually smoothed difference. 310 */ 311 uint32_t t_rcvtime; /* time last segment received */ 312 uint32_t t_rtttime; /* time we started measuring rtt */ 313 tcp_seq t_rtseq; /* sequence number being timed */ 314 int32_t t_srtt; /* smoothed round-trip time */ 315 int32_t t_rttvar; /* variance in round-trip time */ 316 uint32_t t_rttmin; /* minimum rtt allowed */ 317 u_long max_sndwnd; /* largest window peer has offered */ 318 319 /* out-of-band data */ 320 char t_oobflags; /* have some */ 321 char t_iobc; /* input character */ 322 #define TCPOOB_HAVEDATA 0x01 323 #define TCPOOB_HADDATA 0x02 324 short t_softerror; /* possible error not yet reported */ 325 326 /* RFC 1323 variables */ 327 u_char snd_scale; /* window scaling for send window */ 328 u_char rcv_scale; /* window scaling for recv window */ 329 u_char request_r_scale; /* pending window scaling */ 330 u_char requested_s_scale; 331 u_int32_t ts_recent; /* timestamp echo data */ 332 u_int32_t ts_recent_age; /* when last updated */ 333 u_int32_t ts_timebase; /* our timebase */ 334 tcp_seq last_ack_sent; 335 336 /* RFC 3465 variables */ 337 u_long t_bytes_acked; /* ABC "bytes_acked" parameter */ 338 339 /* SACK stuff */ 340 #define TCP_SACK_MAX 3 341 #define TCPSACK_NONE 0 342 #define TCPSACK_HAVED 1 343 u_char rcv_sack_flags; /* SACK flags. */ 344 struct sackblk rcv_dsack_block; /* RX D-SACK block. */ 345 struct ipqehead timeq; /* time sequenced queue. */ 346 struct sackhead snd_holes; /* TX SACK holes. */ 347 int snd_numholes; /* Number of TX SACK holes. */ 348 tcp_seq rcv_lastsack; /* last seq number(+1) sack'd by rcv'r*/ 349 tcp_seq sack_newdata; /* New data xmitted in this recovery 350 episode starts at this seq number*/ 351 tcp_seq snd_fack; /* FACK TCP. Forward-most data held by 352 peer. */ 353 354 /* CUBIC variables */ 355 ulong snd_cubic_wmax; /* W_max */ 356 ulong snd_cubic_wmax_last; /* Used for fast convergence */ 357 ulong snd_cubic_ctime; /* Last congestion time */ 358 359 /* pointer for syn cache entries*/ 360 LIST_HEAD(, syn_cache) t_sc; /* list of entries by this tcb */ 361 362 /* prediction of next mbuf when using large window sizes */ 363 struct mbuf *t_lastm; /* last mbuf that data was sent from */ 364 int t_inoff; /* data offset in previous mbuf */ 365 int t_lastoff; /* last data address in mbuf chain */ 366 int t_lastlen; /* last length read from mbuf chain */ 367 368 /* Path-MTU discovery blackhole detection */ 369 int t_mtudisc; /* perform mtudisc for this tcb */ 370 /* Path-MTU Discovery Information */ 371 u_int t_pmtud_mss_acked; /* MSS acked, lower bound for MTU */ 372 u_int t_pmtud_mtu_sent; /* MTU used, upper bound for MTU */ 373 tcp_seq t_pmtud_th_seq; /* TCP SEQ from ICMP payload */ 374 u_int t_pmtud_nextmtu; /* Advertised Next-Hop MTU from ICMP */ 375 u_short t_pmtud_ip_len; /* IP length from ICMP payload */ 376 u_short t_pmtud_ip_hl; /* IP header length from ICMP payload */ 377 378 uint8_t t_ecn_retries; /* # of ECN setup retries */ 379 380 const struct tcp_congctl *t_congctl; /* per TCB congctl algorithm */ 381 382 /* Keepalive per socket */ 383 u_int t_keepinit; 384 u_int t_keepidle; 385 u_int t_keepintvl; 386 u_int t_keepcnt; 387 u_int t_maxidle; /* t_keepcnt * t_keepintvl */ 388 389 u_int t_msl; /* MSL to use for this connexion */ 390 391 /* maintain a few stats per connection: */ 392 uint32_t t_rcvoopack; /* out-of-order packets received */ 393 uint32_t t_sndrexmitpack; /* retransmit packets sent */ 394 uint32_t t_sndzerowin; /* zero-window updates sent */ 395 }; 396 397 /* 398 * Macros to aid ECN TCP. 399 */ 400 #define TCP_ECN_ALLOWED(tp) (tp->t_flags & TF_ECN_PERMIT) 401 402 /* 403 * Macros to aid SACK/FACK TCP. 404 */ 405 #define TCP_SACK_ENABLED(tp) (tp->t_flags & TF_WILL_SACK) 406 #define TCP_FACK_FASTRECOV(tp) \ 407 (TCP_SACK_ENABLED(tp) && \ 408 (SEQ_GT(tp->snd_fack, tp->snd_una + tcprexmtthresh * tp->t_segsz))) 409 410 #ifdef _KERNEL 411 /* 412 * TCP reassembly queue locks. 413 */ 414 static __inline int tcp_reass_lock_try (struct tcpcb *) 415 __unused; 416 static __inline void tcp_reass_unlock (struct tcpcb *) 417 __unused; 418 419 static __inline int 420 tcp_reass_lock_try(struct tcpcb *tp) 421 { 422 int s; 423 424 /* 425 * Use splvm() -- we're blocking things that would cause 426 * mbuf allocation. 427 */ 428 s = splvm(); 429 if (tp->t_flags & TF_REASSEMBLING) { 430 splx(s); 431 return (0); 432 } 433 tp->t_flags |= TF_REASSEMBLING; 434 splx(s); 435 return (1); 436 } 437 438 static __inline void 439 tcp_reass_unlock(struct tcpcb *tp) 440 { 441 int s; 442 443 s = splvm(); 444 KASSERT((tp->t_flags & TF_REASSEMBLING) != 0); 445 tp->t_flags &= ~TF_REASSEMBLING; 446 splx(s); 447 } 448 449 #ifdef DIAGNOSTIC 450 #define TCP_REASS_LOCK(tp) \ 451 do { \ 452 if (tcp_reass_lock_try(tp) == 0) { \ 453 printf("%s:%d: tcpcb %p reass already locked\n", \ 454 __FILE__, __LINE__, tp); \ 455 panic("tcp_reass_lock"); \ 456 } \ 457 } while (/*CONSTCOND*/ 0) 458 #define TCP_REASS_LOCK_CHECK(tp) \ 459 do { \ 460 if (((tp)->t_flags & TF_REASSEMBLING) == 0) { \ 461 printf("%s:%d: tcpcb %p reass lock not held\n", \ 462 __FILE__, __LINE__, tp); \ 463 panic("tcp reass lock check"); \ 464 } \ 465 } while (/*CONSTCOND*/ 0) 466 #else 467 #define TCP_REASS_LOCK(tp) (void) tcp_reass_lock_try((tp)) 468 #define TCP_REASS_LOCK_CHECK(tp) /* nothing */ 469 #endif 470 471 #define TCP_REASS_UNLOCK(tp) tcp_reass_unlock((tp)) 472 #endif /* _KERNEL */ 473 474 /* 475 * Queue for delayed ACK processing. 476 */ 477 #ifdef _KERNEL 478 extern int tcp_delack_ticks; 479 void tcp_delack(void *); 480 481 #define TCP_RESTART_DELACK(tp) \ 482 callout_reset(&(tp)->t_delack_ch, tcp_delack_ticks, \ 483 tcp_delack, tp) 484 485 #define TCP_SET_DELACK(tp) \ 486 do { \ 487 if (((tp)->t_flags & TF_DELACK) == 0) { \ 488 (tp)->t_flags |= TF_DELACK; \ 489 TCP_RESTART_DELACK(tp); \ 490 } \ 491 } while (/*CONSTCOND*/0) 492 493 #define TCP_CLEAR_DELACK(tp) \ 494 do { \ 495 if ((tp)->t_flags & TF_DELACK) { \ 496 (tp)->t_flags &= ~TF_DELACK; \ 497 callout_stop(&(tp)->t_delack_ch); \ 498 } \ 499 } while (/*CONSTCOND*/0) 500 #endif /* _KERNEL */ 501 502 /* 503 * Compute the current timestamp for a connection. 504 */ 505 #define TCP_TIMESTAMP(tp) (tcp_now - (tp)->ts_timebase) 506 507 /* 508 * Handy way of passing around TCP option info. 509 */ 510 struct tcp_opt_info { 511 int ts_present; 512 u_int32_t ts_val; 513 u_int32_t ts_ecr; 514 u_int16_t maxseg; 515 }; 516 517 #define TOF_SIGNATURE 0x0040 /* signature option present */ 518 #define TOF_SIGLEN 0x0080 /* sigature length valid (RFC2385) */ 519 520 /* 521 * Data for the TCP compressed state engine. 522 */ 523 union syn_cache_sa { 524 struct sockaddr sa; 525 struct sockaddr_in sin; 526 #if 1 /*def INET6*/ 527 struct sockaddr_in6 sin6; 528 #endif 529 }; 530 531 struct syn_cache { 532 TAILQ_ENTRY(syn_cache) sc_bucketq; /* link on bucket list */ 533 callout_t sc_timer; /* rexmt timer */ 534 struct route sc_route; 535 long sc_win; /* advertised window */ 536 int sc_bucketidx; /* our bucket index */ 537 u_int32_t sc_hash; 538 u_int32_t sc_timestamp; /* timestamp from SYN */ 539 u_int32_t sc_timebase; /* our local timebase */ 540 union syn_cache_sa sc_src; 541 union syn_cache_sa sc_dst; 542 tcp_seq sc_irs; 543 tcp_seq sc_iss; 544 u_int sc_rxtcur; /* current rxt timeout */ 545 u_int sc_rxttot; /* total time spend on queues */ 546 u_short sc_rxtshift; /* for computing backoff */ 547 u_short sc_flags; 548 549 #define SCF_UNREACH 0x0001 /* we've had an unreach error */ 550 #define SCF_TIMESTAMP 0x0002 /* peer will do timestamps */ 551 #define SCF_DEAD 0x0004 /* this entry to be released */ 552 #define SCF_SACK_PERMIT 0x0008 /* peer will do SACK */ 553 #define SCF_ECN_PERMIT 0x0010 /* peer will do ECN */ 554 #define SCF_SIGNATURE 0x40 /* send MD5 digests */ 555 556 struct mbuf *sc_ipopts; /* IP options */ 557 u_int16_t sc_peermaxseg; 558 u_int16_t sc_ourmaxseg; 559 u_int8_t sc_request_r_scale : 4, 560 sc_requested_s_scale : 4; 561 562 struct tcpcb *sc_tp; /* tcb for listening socket */ 563 LIST_ENTRY(syn_cache) sc_tpq; /* list of entries by same tp */ 564 }; 565 566 struct syn_cache_head { 567 TAILQ_HEAD(, syn_cache) sch_bucket; /* bucket entries */ 568 u_short sch_length; /* # entries in bucket */ 569 }; 570 571 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 572 #ifdef INET6 573 #define in6totcpcb(ip) ((struct tcpcb *)(ip)->in6p_ppcb) 574 #endif 575 #ifndef INET6 576 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 577 #else 578 #define sototcpcb(so) (((so)->so_proto->pr_domain->dom_family == AF_INET) \ 579 ? intotcpcb(sotoinpcb(so)) \ 580 : in6totcpcb(sotoin6pcb(so))) 581 #endif 582 583 /* 584 * See RFC2988 for a discussion of RTO calculation; comments assume 585 * familiarity with that document. 586 * 587 * The smoothed round-trip time and estimated variance are stored as 588 * fixed point numbers. Historically, srtt was scaled by 589 * TCP_RTT_SHIFT bits, and rttvar by TCP_RTTVAR_SHIFT bits. Because 590 * the values coincide with the alpha and beta parameters suggested 591 * for RTO calculation (1/8 for srtt, 1/4 for rttvar), the combination 592 * of computing 1/8 of the new value and transforming it to the 593 * fixed-point representation required zero instructions. However, 594 * the storage representations no longer coincide with the alpha/beta 595 * shifts; instead, more fractional bits are present. 596 * 597 * The storage representation of srtt is 1/32 slow ticks, or 1/64 s. 598 * (The assumption that a slow tick is 500 ms should not be present in 599 * the code.) 600 * 601 * The storage representation of rttvar is 1/16 slow ticks, or 1/32 s. 602 * There may be some confusion about this in the code. 603 * 604 * For historical reasons, these scales are also used in smoothing the 605 * average (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 606 * This results in alpha of 0.125 and beta of 0.25, following RFC2988 607 * section 2.3 608 * 609 * XXX Change SHIFT values to LGWEIGHT and REP_SHIFT, and adjust 610 * the code to use the correct ones. 611 */ 612 #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ 613 #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */ 614 615 /* 616 * Compute TCP retransmission timer, following RFC2988. 617 * This macro returns a value in slow timeout ticks. 618 * 619 * Section 2.2 requires that the RTO value be 620 * srtt + max(G, 4*RTTVAR) 621 * where G is the clock granularity. 622 * 623 * This comment has not necessarily been updated for the new storage 624 * representation: 625 * 626 * Because of the way we do the smoothing, srtt and rttvar 627 * will each average +1/2 tick of bias. When we compute 628 * the retransmit timer, we want 1/2 tick of rounding and 629 * 1 extra tick because of +-1/2 tick uncertainty in the 630 * firing of the timer. The bias will give us exactly the 631 * 1.5 tick we need. But, because the bias is 632 * statistical, we have to test that we don't drop below 633 * the minimum feasible timer (which is 2 ticks). 634 * This macro assumes that the value of 1<<TCP_RTTVAR_SHIFT 635 * is the same as the multiplier for rttvar. 636 * 637 * This macro appears to be wrong; it should be checking rttvar*4 in 638 * ticks and making sure we use 1 instead if rttvar*4 rounds to 0. It 639 * appears to be treating srtt as being in the old storage 640 * representation, resulting in a factor of 4 extra. 641 */ 642 #define TCP_REXMTVAL(tp) \ 643 ((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) >> 2) 644 645 /* 646 * Compute the initial window for slow start. 647 */ 648 #define TCP_INITIAL_WINDOW(iw, segsz) \ 649 uimin((iw) * (segsz), uimax(2 * (segsz), tcp_init_win_max[(iw)])) 650 651 /* 652 * TCP statistics. 653 * Each counter is an unsigned 64-bit value. 654 * 655 * Many of these should be kept per connection, but that's inconvenient 656 * at the moment. 657 */ 658 #define TCP_STAT_CONNATTEMPT 0 /* connections initiated */ 659 #define TCP_STAT_ACCEPTS 1 /* connections accepted */ 660 #define TCP_STAT_CONNECTS 2 /* connections established */ 661 #define TCP_STAT_DROPS 3 /* connections dropped */ 662 #define TCP_STAT_CONNDROPS 4 /* embryonic connections dropped */ 663 #define TCP_STAT_CLOSED 5 /* conn. closed (includes drops) */ 664 #define TCP_STAT_SEGSTIMED 6 /* segs where we tried to get rtt */ 665 #define TCP_STAT_RTTUPDATED 7 /* times we succeeded */ 666 #define TCP_STAT_DELACK 8 /* delayed ACKs sent */ 667 #define TCP_STAT_TIMEOUTDROP 9 /* conn. dropped in rxmt timeout */ 668 #define TCP_STAT_REXMTTIMEO 10 /* retransmit timeouts */ 669 #define TCP_STAT_PERSISTTIMEO 11 /* persist timeouts */ 670 #define TCP_STAT_KEEPTIMEO 12 /* keepalive timeouts */ 671 #define TCP_STAT_KEEPPROBE 13 /* keepalive probes sent */ 672 #define TCP_STAT_KEEPDROPS 14 /* connections dropped in keepalive */ 673 #define TCP_STAT_PERSISTDROPS 15 /* connections dropped in persist */ 674 #define TCP_STAT_CONNSDRAINED 16 /* connections drained due to memory 675 shortage */ 676 #define TCP_STAT_PMTUBLACKHOLE 17 /* PMTUD blackhole detected */ 677 #define TCP_STAT_SNDTOTAL 18 /* total packets sent */ 678 #define TCP_STAT_SNDPACK 19 /* data packlets sent */ 679 #define TCP_STAT_SNDBYTE 20 /* data bytes sent */ 680 #define TCP_STAT_SNDREXMITPACK 21 /* data packets retransmitted */ 681 #define TCP_STAT_SNDREXMITBYTE 22 /* data bytes retransmitted */ 682 #define TCP_STAT_SNDACKS 23 /* ACK-only packets sent */ 683 #define TCP_STAT_SNDPROBE 24 /* window probes sent */ 684 #define TCP_STAT_SNDURG 25 /* packets sent with URG only */ 685 #define TCP_STAT_SNDWINUP 26 /* window update-only packets sent */ 686 #define TCP_STAT_SNDCTRL 27 /* control (SYN|FIN|RST) packets sent */ 687 #define TCP_STAT_RCVTOTAL 28 /* total packets received */ 688 #define TCP_STAT_RCVPACK 29 /* packets received in sequence */ 689 #define TCP_STAT_RCVBYTE 30 /* bytes received in sequence */ 690 #define TCP_STAT_RCVBADSUM 31 /* packets received with cksum errs */ 691 #define TCP_STAT_RCVBADOFF 32 /* packets received with bad offset */ 692 #define TCP_STAT_RCVMEMDROP 33 /* packets dropped for lack of memory */ 693 #define TCP_STAT_RCVSHORT 34 /* packets received too short */ 694 #define TCP_STAT_RCVDUPPACK 35 /* duplicate-only packets received */ 695 #define TCP_STAT_RCVDUPBYTE 36 /* duplicate-only bytes received */ 696 #define TCP_STAT_RCVPARTDUPPACK 37 /* packets with some duplicate data */ 697 #define TCP_STAT_RCVPARTDUPBYTE 38 /* dup. bytes in part-dup. packets */ 698 #define TCP_STAT_RCVOOPACK 39 /* out-of-order packets received */ 699 #define TCP_STAT_RCVOOBYTE 40 /* out-of-order bytes received */ 700 #define TCP_STAT_RCVPACKAFTERWIN 41 /* packets with data after window */ 701 #define TCP_STAT_RCVBYTEAFTERWIN 42 /* bytes received after window */ 702 #define TCP_STAT_RCVAFTERCLOSE 43 /* packets received after "close" */ 703 #define TCP_STAT_RCVWINPROBE 44 /* rcvd window probe packets */ 704 #define TCP_STAT_RCVDUPACK 45 /* rcvd duplicate ACKs */ 705 #define TCP_STAT_RCVACKTOOMUCH 46 /* rcvd ACKs for unsent data */ 706 #define TCP_STAT_RCVACKPACK 47 /* rcvd ACK packets */ 707 #define TCP_STAT_RCVACKBYTE 48 /* bytes ACKed by rcvd ACKs */ 708 #define TCP_STAT_RCVWINUPD 49 /* rcvd window update packets */ 709 #define TCP_STAT_PAWSDROP 50 /* segments dropped due to PAWS */ 710 #define TCP_STAT_PREDACK 51 /* times hdr predict OK for ACKs */ 711 #define TCP_STAT_PREDDAT 52 /* times hdr predict OK for data pkts */ 712 #define TCP_STAT_PCBHASHMISS 53 /* input packets missing PCB hash */ 713 #define TCP_STAT_NOPORT 54 /* no socket on port */ 714 #define TCP_STAT_BADSYN 55 /* received ACK for which we have 715 no SYN in compressed state */ 716 #define TCP_STAT_DELAYED_FREE 56 /* delayed pool_put() of tcpcb */ 717 #define TCP_STAT_SC_ADDED 57 /* # of sc entries added */ 718 #define TCP_STAT_SC_COMPLETED 58 /* # of sc connections completed */ 719 #define TCP_STAT_SC_TIMED_OUT 59 /* # of sc entries timed out */ 720 #define TCP_STAT_SC_OVERFLOWED 60 /* # of sc drops due to overflow */ 721 #define TCP_STAT_SC_RESET 61 /* # of sc drops due to RST */ 722 #define TCP_STAT_SC_UNREACH 62 /* # of sc drops due to ICMP unreach */ 723 #define TCP_STAT_SC_BUCKETOVERFLOW 63 /* # of sc drops due to bucket ovflow */ 724 #define TCP_STAT_SC_ABORTED 64 /* # of sc entries aborted (no mem) */ 725 #define TCP_STAT_SC_DUPESYN 65 /* # of duplicate SYNs received */ 726 #define TCP_STAT_SC_DROPPED 66 /* # of SYNs dropped (no route/mem) */ 727 #define TCP_STAT_SC_COLLISIONS 67 /* # of sc hash collisions */ 728 #define TCP_STAT_SC_RETRANSMITTED 68 /* # of sc retransmissions */ 729 #define TCP_STAT_SC_DELAYED_FREE 69 /* # of delayed pool_put()s */ 730 #define TCP_STAT_SELFQUENCH 70 /* # of ENOBUFS we get on output */ 731 #define TCP_STAT_BADSIG 71 /* # of drops due to bad signature */ 732 #define TCP_STAT_GOODSIG 72 /* # of packets with good signature */ 733 #define TCP_STAT_ECN_SHS 73 /* # of successful ECN handshakes */ 734 #define TCP_STAT_ECN_CE 74 /* # of packets with CE bit */ 735 #define TCP_STAT_ECN_ECT 75 /* # of packets with ECT(0) bit */ 736 737 #define TCP_NSTATS 76 738 739 /* 740 * Names for TCP sysctl objects. 741 */ 742 #define TCPCTL_RFC1323 1 /* RFC1323 timestamps/scaling */ 743 #define TCPCTL_SENDSPACE 2 /* default send buffer */ 744 #define TCPCTL_RECVSPACE 3 /* default recv buffer */ 745 #define TCPCTL_MSSDFLT 4 /* default seg size */ 746 #define TCPCTL_SYN_CACHE_LIMIT 5 /* max size of comp. state engine */ 747 #define TCPCTL_SYN_BUCKET_LIMIT 6 /* max size of hash bucket */ 748 #if 0 /*obsoleted*/ 749 #define TCPCTL_SYN_CACHE_INTER 7 /* interval of comp. state timer */ 750 #endif 751 #define TCPCTL_INIT_WIN 8 /* initial window */ 752 #define TCPCTL_MSS_IFMTU 9 /* mss from interface, not in_maxmtu */ 753 #define TCPCTL_SACK 10 /* RFC2018 selective acknowledgement */ 754 #define TCPCTL_WSCALE 11 /* RFC1323 window scaling */ 755 #define TCPCTL_TSTAMP 12 /* RFC1323 timestamps */ 756 #if 0 /*obsoleted*/ 757 #define TCPCTL_COMPAT_42 13 /* 4.2BSD TCP bug work-arounds */ 758 #endif 759 #define TCPCTL_CWM 14 /* Congestion Window Monitoring */ 760 #define TCPCTL_CWM_BURSTSIZE 15 /* burst size allowed by CWM */ 761 #define TCPCTL_ACK_ON_PUSH 16 /* ACK immediately on PUSH */ 762 #define TCPCTL_KEEPIDLE 17 /* keepalive idle time */ 763 #define TCPCTL_KEEPINTVL 18 /* keepalive probe interval */ 764 #define TCPCTL_KEEPCNT 19 /* keepalive count */ 765 #define TCPCTL_SLOWHZ 20 /* PR_SLOWHZ (read-only) */ 766 #define TCPCTL_NEWRENO 21 /* NewReno Congestion Control */ 767 #define TCPCTL_LOG_REFUSED 22 /* Log refused connections */ 768 #if 0 /*obsoleted*/ 769 #define TCPCTL_RSTRATELIMIT 23 /* RST rate limit */ 770 #endif 771 #define TCPCTL_RSTPPSLIMIT 24 /* RST pps limit */ 772 #define TCPCTL_DELACK_TICKS 25 /* # ticks to delay ACK */ 773 #define TCPCTL_INIT_WIN_LOCAL 26 /* initial window for local nets */ 774 #define TCPCTL_IDENT 27 /* rfc 931 identd */ 775 #define TCPCTL_ACKDROPRATELIMIT 28 /* SYN/RST -> ACK rate limit */ 776 #define TCPCTL_LOOPBACKCKSUM 29 /* do TCP checksum on loopback */ 777 #define TCPCTL_STATS 30 /* TCP statistics */ 778 #define TCPCTL_DEBUG 31 /* TCP debug sockets */ 779 #define TCPCTL_DEBX 32 /* # of tcp debug sockets */ 780 #define TCPCTL_DROP 33 /* drop tcp connection */ 781 #define TCPCTL_MSL 34 /* Max Segment Life */ 782 783 #ifdef _KERNEL 784 785 extern struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 786 extern const struct pr_usrreqs tcp_usrreqs; 787 788 extern u_int32_t tcp_now; /* for RFC 1323 timestamps */ 789 extern int tcp_do_rfc1323; /* enabled/disabled? */ 790 extern int tcp_do_sack; /* SACK enabled/disabled? */ 791 extern int tcp_do_win_scale; /* RFC1323 window scaling enabled/disabled? */ 792 extern int tcp_do_timestamps; /* RFC1323 timestamps enabled/disabled? */ 793 extern int tcp_mssdflt; /* default seg size */ 794 extern int tcp_minmss; /* minimal seg size */ 795 extern int tcp_msl; /* max segment life */ 796 extern int tcp_init_win; /* initial window */ 797 extern int tcp_init_win_local; /* initial window for local nets */ 798 extern int tcp_init_win_max[11];/* max sizes for values of tcp_init_win_* */ 799 extern int tcp_mss_ifmtu; /* take MSS from interface, not in_maxmtu */ 800 extern int tcp_cwm; /* enable Congestion Window Monitoring */ 801 extern int tcp_cwm_burstsize; /* burst size allowed by CWM */ 802 extern int tcp_ack_on_push; /* ACK immediately on PUSH */ 803 extern int tcp_syn_cache_limit; /* max entries for compressed state engine */ 804 extern int tcp_syn_bucket_limit;/* max entries per hash bucket */ 805 extern int tcp_log_refused; /* log refused connections */ 806 extern int tcp_do_ecn; /* TCP ECN enabled/disabled? */ 807 extern int tcp_ecn_maxretries; /* Max ECN setup retries */ 808 extern int tcp_do_rfc1948; /* ISS by cryptographic hash */ 809 extern int tcp_sack_tp_maxholes; /* Max holes per connection. */ 810 extern int tcp_sack_globalmaxholes; /* Max holes per system. */ 811 extern int tcp_sack_globalholes; /* Number of holes present. */ 812 extern int tcp_do_abc; /* RFC3465 ABC enabled/disabled? */ 813 extern int tcp_abc_aggressive; /* 1: L=2*SMSS 0: L=1*SMSS */ 814 815 extern int tcp_msl_enable; /* enable TIME_WAIT truncation */ 816 extern int tcp_msl_loop; /* MSL for loopback */ 817 extern int tcp_msl_local; /* MSL for 'local' */ 818 extern int tcp_msl_remote; /* MSL otherwise */ 819 extern int tcp_msl_remote_threshold; /* RTT threshold */ 820 extern int tcp_rttlocal; /* Use RTT to decide who's 'local' */ 821 extern int tcp4_vtw_enable; 822 extern int tcp6_vtw_enable; 823 extern int tcp_vtw_was_enabled; 824 extern int tcp_vtw_entries; 825 826 extern int tcp_rst_ppslim; 827 extern int tcp_ackdrop_ppslim; 828 829 extern int tcp_syn_cache_size; 830 extern struct syn_cache_head tcp_syn_cache[]; 831 extern u_long syn_cache_count; 832 833 #ifdef MBUFTRACE 834 extern struct mowner tcp_rx_mowner; 835 extern struct mowner tcp_tx_mowner; 836 extern struct mowner tcp_reass_mowner; 837 extern struct mowner tcp_sock_mowner; 838 extern struct mowner tcp_sock_rx_mowner; 839 extern struct mowner tcp_sock_tx_mowner; 840 extern struct mowner tcp_mowner; 841 #endif 842 843 extern int tcp_do_autorcvbuf; 844 extern int tcp_autorcvbuf_inc; 845 extern int tcp_autorcvbuf_max; 846 extern int tcp_do_autosndbuf; 847 extern int tcp_autosndbuf_inc; 848 extern int tcp_autosndbuf_max; 849 850 struct secasvar; 851 852 void tcp_canceltimers(struct tcpcb *); 853 struct tcpcb * 854 tcp_close(struct tcpcb *); 855 int tcp_isdead(struct tcpcb *); 856 #ifdef INET6 857 void *tcp6_ctlinput(int, const struct sockaddr *, void *); 858 #endif 859 void *tcp_ctlinput(int, const struct sockaddr *, void *); 860 int tcp_ctloutput(int, struct socket *, struct sockopt *); 861 struct tcpcb * 862 tcp_disconnect1(struct tcpcb *); 863 struct tcpcb * 864 tcp_drop(struct tcpcb *, int); 865 #ifdef TCP_SIGNATURE 866 int tcp_signature_apply(void *, void *, u_int); 867 struct secasvar *tcp_signature_getsav(struct mbuf *); 868 int tcp_signature(struct mbuf *, struct tcphdr *, int, struct secasvar *, 869 char *); 870 #endif 871 void tcp_drain(void); 872 void tcp_drainstub(void); 873 void tcp_established(struct tcpcb *); 874 void tcp_init(void); 875 void tcp_init_common(unsigned); 876 #ifdef INET6 877 int tcp6_input(struct mbuf **, int *, int); 878 #endif 879 void tcp_input(struct mbuf *, int, int); 880 u_int tcp_hdrsz(struct tcpcb *); 881 u_long tcp_mss_to_advertise(const struct ifnet *, int); 882 void tcp_mss_from_peer(struct tcpcb *, int); 883 void tcp_tcpcb_template(void); 884 struct tcpcb * 885 tcp_newtcpcb(int, void *); 886 void tcp_notify(struct inpcb *, int); 887 #ifdef INET6 888 void tcp6_notify(struct in6pcb *, int); 889 #endif 890 u_int tcp_optlen(struct tcpcb *); 891 int tcp_output(struct tcpcb *); 892 void tcp_pulloutofband(struct socket *, 893 struct tcphdr *, struct mbuf *, int); 894 void tcp_quench(struct inpcb *); 895 #ifdef INET6 896 void tcp6_quench(struct in6pcb *); 897 #endif 898 void tcp_mtudisc(struct inpcb *, int); 899 #ifdef INET6 900 void tcp6_mtudisc_callback(struct in6_addr *); 901 #endif 902 903 void tcpipqent_init(void); 904 struct ipqent *tcpipqent_alloc(void); 905 void tcpipqent_free(struct ipqent *); 906 907 int tcp_respond(struct tcpcb *, struct mbuf *, struct mbuf *, 908 struct tcphdr *, tcp_seq, tcp_seq, int); 909 void tcp_rmx_rtt(struct tcpcb *); 910 void tcp_setpersist(struct tcpcb *); 911 #ifdef TCP_SIGNATURE 912 int tcp_signature_compute(struct mbuf *, struct tcphdr *, int, int, 913 int, u_char *, u_int); 914 #endif 915 void tcp_fasttimo(void); 916 struct mbuf * 917 tcp_template(struct tcpcb *); 918 void tcp_trace(short, short, struct tcpcb *, struct mbuf *, int); 919 struct tcpcb * 920 tcp_usrclosed(struct tcpcb *); 921 void tcp_usrreq_init(void); 922 void tcp_xmit_timer(struct tcpcb *, uint32_t); 923 tcp_seq tcp_new_iss(struct tcpcb *, tcp_seq); 924 tcp_seq tcp_new_iss1(void *, void *, u_int16_t, u_int16_t, size_t, 925 tcp_seq); 926 927 void tcp_sack_init(void); 928 void tcp_new_dsack(struct tcpcb *, tcp_seq, u_int32_t); 929 void tcp_sack_option(struct tcpcb *, const struct tcphdr *, 930 const u_char *, int); 931 void tcp_del_sackholes(struct tcpcb *, const struct tcphdr *); 932 void tcp_free_sackholes(struct tcpcb *); 933 void tcp_sack_adjust(struct tcpcb *tp); 934 struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt); 935 int tcp_sack_numblks(const struct tcpcb *); 936 #define TCP_SACK_OPTLEN(nblks) ((nblks) * 8 + 2 + 2) 937 938 void tcp_statinc(u_int); 939 void tcp_statadd(u_int, uint64_t); 940 941 int syn_cache_add(struct sockaddr *, struct sockaddr *, 942 struct tcphdr *, unsigned int, struct socket *, 943 struct mbuf *, u_char *, int, struct tcp_opt_info *); 944 void syn_cache_unreach(const struct sockaddr *, const struct sockaddr *, 945 struct tcphdr *); 946 struct socket *syn_cache_get(struct sockaddr *, struct sockaddr *, 947 struct tcphdr *, struct socket *so, struct mbuf *); 948 void syn_cache_init(void); 949 void syn_cache_insert(struct syn_cache *, struct tcpcb *); 950 struct syn_cache *syn_cache_lookup(const struct sockaddr *, const struct sockaddr *, 951 struct syn_cache_head **); 952 void syn_cache_reset(struct sockaddr *, struct sockaddr *, 953 struct tcphdr *); 954 int syn_cache_respond(struct syn_cache *); 955 void syn_cache_cleanup(struct tcpcb *); 956 957 int tcp_input_checksum(int, struct mbuf *, const struct tcphdr *, int, int, 958 int); 959 #endif 960 961 #endif /* !_NETINET_TCP_VAR_H_ */ 962
Indexes created Wed Sep 24 02:09:48 GMT 2025