tcp_var.h revision 1.139
1 /* $NetBSD: tcp_var.h,v 1.139 2006/10/16 18:13:56 rpaulo 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 * 3. All advertising materials mentioning features or use of this software 91 * must display the following acknowledgement: 92 * This product includes software developed by the NetBSD 93 * Foundation, Inc. and its contributors. 94 * 4. Neither the name of The NetBSD Foundation nor the names of its 95 * contributors may be used to endorse or promote products derived 96 * from this software without specific prior written permission. 97 * 98 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 99 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 100 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 101 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 102 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 103 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 104 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 105 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 106 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 107 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 108 * POSSIBILITY OF SUCH DAMAGE. 109 */ 110 111 /* 112 * Copyright (c) 1982, 1986, 1993, 1994, 1995 113 * The Regents of the University of California. All rights reserved. 114 * 115 * Redistribution and use in source and binary forms, with or without 116 * modification, are permitted provided that the following conditions 117 * are met: 118 * 1. Redistributions of source code must retain the above copyright 119 * notice, this list of conditions and the following disclaimer. 120 * 2. Redistributions in binary form must reproduce the above copyright 121 * notice, this list of conditions and the following disclaimer in the 122 * documentation and/or other materials provided with the distribution. 123 * 3. Neither the name of the University nor the names of its contributors 124 * may be used to endorse or promote products derived from this software 125 * without specific prior written permission. 126 * 127 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 128 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 129 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 130 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 131 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 132 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 133 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 134 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 135 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 136 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 137 * SUCH DAMAGE. 138 * 139 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95 140 */ 141 142 #ifndef _NETINET_TCP_VAR_H_ 143 #define _NETINET_TCP_VAR_H_ 144 145 #if defined(_KERNEL_OPT) 146 #include "opt_inet.h" 147 #include "opt_mbuftrace.h" 148 #include "rnd.h" 149 #endif 150 151 /* 152 * Kernel variables for tcp. 153 */ 154 155 #include <sys/callout.h> 156 157 #ifdef TCP_SIGNATURE 158 /* 159 * Defines which are needed by the xform_tcp module and tcp_[in|out]put 160 * for SADB verification and lookup. 161 */ 162 #define TCP_SIGLEN 16 /* length of computed digest in bytes */ 163 #define TCP_KEYLEN_MIN 1 /* minimum length of TCP-MD5 key */ 164 #define TCP_KEYLEN_MAX 80 /* maximum length of TCP-MD5 key */ 165 /* 166 * Only a single SA per host may be specified at this time. An SPI is 167 * needed in order for the KEY_ALLOCSA() lookup to work. 168 */ 169 #define TCP_SIG_SPI 0x1000 170 #endif /* TCP_SIGNATURE */ 171 172 /* 173 * SACK option block. 174 */ 175 struct sackblk { 176 tcp_seq left; /* Left edge of sack block. */ 177 tcp_seq right; /* Right edge of sack block. */ 178 }; 179 180 TAILQ_HEAD(sackhead, sackhole); 181 struct sackhole { 182 tcp_seq start; 183 tcp_seq end; 184 tcp_seq rxmit; 185 186 TAILQ_ENTRY(sackhole) sackhole_q; 187 }; 188 189 /* 190 * Tcp control block, one per tcp; fields: 191 */ 192 struct tcpcb { 193 int t_family; /* address family on the wire */ 194 struct ipqehead segq; /* sequencing queue */ 195 int t_segqlen; /* length of the above */ 196 struct callout t_timer[TCPT_NTIMERS];/* tcp timers */ 197 short t_state; /* state of this connection */ 198 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 199 uint32_t t_rxtcur; /* current retransmit value */ 200 short t_dupacks; /* consecutive dup acks recd */ 201 short t_partialacks; /* partials acks during fast rexmit */ 202 u_short t_peermss; /* peer's maximum segment size */ 203 u_short t_ourmss; /* our's maximum segment size */ 204 u_short t_segsz; /* current segment size in use */ 205 char t_force; /* 1 if forcing out a byte */ 206 u_int t_flags; 207 #define TF_ACKNOW 0x0001 /* ack peer immediately */ 208 #define TF_DELACK 0x0002 /* ack, but try to delay it */ 209 #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */ 210 #define TF_NOOPT 0x0008 /* don't use tcp options */ 211 #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */ 212 #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */ 213 #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */ 214 #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */ 215 #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */ 216 #define TF_SYN_REXMT 0x0400 /* rexmit timer fired on SYN */ 217 #define TF_WILL_SACK 0x0800 /* try to use SACK */ 218 #define TF_REASSEMBLING 0x1000 /* we're busy reassembling */ 219 #define TF_DEAD 0x2000 /* dead and to-be-released */ 220 #define TF_PMTUD_PEND 0x4000 /* Path MTU Discovery pending */ 221 #define TF_ECN_PERMIT 0x10000 /* other side said is ECN-ready */ 222 #define TF_ECN_SND_CWR 0x20000 /* ECN CWR in queue */ 223 #define TF_ECN_SND_ECE 0x40000 /* ECN ECE in queue */ 224 #define TF_SIGNATURE 0x400000 /* require MD5 digests (RFC2385) */ 225 226 227 struct mbuf *t_template; /* skeletal packet for transmit */ 228 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 229 struct in6pcb *t_in6pcb; /* back pointer to internet pcb */ 230 struct callout t_delack_ch; /* delayed ACK callout */ 231 /* 232 * The following fields are used as in the protocol specification. 233 * See RFC793, Dec. 1981, page 21. 234 */ 235 /* send sequence variables */ 236 tcp_seq snd_una; /* send unacknowledged */ 237 tcp_seq snd_nxt; /* send next */ 238 tcp_seq snd_up; /* send urgent pointer */ 239 tcp_seq snd_wl1; /* window update seg seq number */ 240 tcp_seq snd_wl2; /* window update seg ack number */ 241 tcp_seq iss; /* initial send sequence number */ 242 u_long snd_wnd; /* send window */ 243 tcp_seq snd_recover; /* for use in fast recovery */ 244 tcp_seq snd_high; /* NewReno false fast rexmit seq */ 245 /* receive sequence variables */ 246 u_long rcv_wnd; /* receive window */ 247 tcp_seq rcv_nxt; /* receive next */ 248 tcp_seq rcv_up; /* receive urgent pointer */ 249 tcp_seq irs; /* initial receive sequence number */ 250 /* 251 * Additional variables for this implementation. 252 */ 253 /* receive variables */ 254 tcp_seq rcv_adv; /* advertised window */ 255 /* retransmit variables */ 256 tcp_seq snd_max; /* highest sequence number sent; 257 * used to recognize retransmits 258 */ 259 /* congestion control (for slow start, source quench, retransmit after loss) */ 260 u_long snd_cwnd; /* congestion-controlled window */ 261 u_long snd_ssthresh; /* snd_cwnd size threshhold for 262 * for slow start exponential to 263 * linear switch 264 */ 265 /* 266 * transmit timing stuff. See below for scale of srtt and rttvar. 267 * "Variance" is actually smoothed difference. 268 */ 269 uint32_t t_rcvtime; /* time last segment received */ 270 uint32_t t_rtttime; /* time we started measuring rtt */ 271 tcp_seq t_rtseq; /* sequence number being timed */ 272 int32_t t_srtt; /* smoothed round-trip time */ 273 int32_t t_rttvar; /* variance in round-trip time */ 274 uint32_t t_rttmin; /* minimum rtt allowed */ 275 u_long max_sndwnd; /* largest window peer has offered */ 276 277 /* out-of-band data */ 278 char t_oobflags; /* have some */ 279 char t_iobc; /* input character */ 280 #define TCPOOB_HAVEDATA 0x01 281 #define TCPOOB_HADDATA 0x02 282 short t_softerror; /* possible error not yet reported */ 283 284 /* RFC 1323 variables */ 285 u_char snd_scale; /* window scaling for send window */ 286 u_char rcv_scale; /* window scaling for recv window */ 287 u_char request_r_scale; /* pending window scaling */ 288 u_char requested_s_scale; 289 u_int32_t ts_recent; /* timestamp echo data */ 290 u_int32_t ts_recent_age; /* when last updated */ 291 u_int32_t ts_timebase; /* our timebase */ 292 tcp_seq last_ack_sent; 293 294 /* SACK stuff */ 295 #define TCP_SACK_MAX 3 296 #define TCPSACK_NONE 0 297 #define TCPSACK_HAVED 1 298 u_char rcv_sack_flags; /* SACK flags. */ 299 struct sackblk rcv_dsack_block; /* RX D-SACK block. */ 300 struct ipqehead timeq; /* time sequenced queue. */ 301 struct sackhead snd_holes; /* TX SACK holes. */ 302 int snd_numholes; /* Number of TX SACK holes. */ 303 tcp_seq rcv_lastsack; /* last seq number(+1) sack'd by rcv'r*/ 304 tcp_seq sack_newdata; /* New data xmitted in this recovery 305 episode starts at this seq number*/ 306 tcp_seq snd_fack; /* FACK TCP. Forward-most data held by 307 peer. */ 308 309 /* pointer for syn cache entries*/ 310 LIST_HEAD(, syn_cache) t_sc; /* list of entries by this tcb */ 311 312 /* prediction of next mbuf when using large window sizes */ 313 struct mbuf *t_lastm; /* last mbuf that data was sent from */ 314 int t_inoff; /* data offset in previous mbuf */ 315 int t_lastoff; /* last data address in mbuf chain */ 316 int t_lastlen; /* last length read from mbuf chain */ 317 318 /* Path-MTU discovery blackhole detection */ 319 int t_mtudisc; /* perform mtudisc for this tcb */ 320 /* Path-MTU Discovery Information */ 321 u_int t_pmtud_mss_acked; /* MSS acked, lower bound for MTU */ 322 u_int t_pmtud_mtu_sent; /* MTU used, upper bound for MTU */ 323 tcp_seq t_pmtud_th_seq; /* TCP SEQ from ICMP payload */ 324 u_int t_pmtud_nextmtu; /* Advertised Next-Hop MTU from ICMP */ 325 u_short t_pmtud_ip_len; /* IP length from ICMP payload */ 326 u_short t_pmtud_ip_hl; /* IP header length from ICMP payload */ 327 328 uint8_t t_ecn_retries; /* # of ECN setup retries */ 329 330 struct tcp_congctl *t_congctl; /* per TCB congctl algorithm */ 331 }; 332 333 /* 334 * Macros to aid ECN TCP. 335 */ 336 #define TCP_ECN_ALLOWED(tp) (tp->t_flags & TF_ECN_PERMIT) 337 338 /* 339 * Macros to aid SACK/FACK TCP. 340 */ 341 #define TCP_SACK_ENABLED(tp) (tp->t_flags & TF_WILL_SACK) 342 #define TCP_FACK_FASTRECOV(tp) \ 343 (TCP_SACK_ENABLED(tp) && \ 344 (SEQ_GT(tp->snd_fack, tp->snd_una + tcprexmtthresh * tp->t_segsz))) 345 346 #ifdef _KERNEL 347 /* 348 * TCP reassembly queue locks. 349 */ 350 static __inline int tcp_reass_lock_try (struct tcpcb *) 351 __attribute__((__unused__)); 352 static __inline void tcp_reass_unlock (struct tcpcb *) 353 __attribute__((__unused__)); 354 355 static __inline int 356 tcp_reass_lock_try(tp) 357 struct tcpcb *tp; 358 { 359 int s; 360 361 /* 362 * Use splvm() -- we're blocking things that would cause 363 * mbuf allocation. 364 */ 365 s = splvm(); 366 if (tp->t_flags & TF_REASSEMBLING) { 367 splx(s); 368 return (0); 369 } 370 tp->t_flags |= TF_REASSEMBLING; 371 splx(s); 372 return (1); 373 } 374 375 static __inline void 376 tcp_reass_unlock(tp) 377 struct tcpcb *tp; 378 { 379 int s; 380 381 s = splvm(); 382 tp->t_flags &= ~TF_REASSEMBLING; 383 splx(s); 384 } 385 386 #ifdef DIAGNOSTIC 387 #define TCP_REASS_LOCK(tp) \ 388 do { \ 389 if (tcp_reass_lock_try(tp) == 0) { \ 390 printf("%s:%d: tcpcb %p reass already locked\n", \ 391 __FILE__, __LINE__, tp); \ 392 panic("tcp_reass_lock"); \ 393 } \ 394 } while (/*CONSTCOND*/ 0) 395 #define TCP_REASS_LOCK_CHECK(tp) \ 396 do { \ 397 if (((tp)->t_flags & TF_REASSEMBLING) == 0) { \ 398 printf("%s:%d: tcpcb %p reass lock not held\n", \ 399 __FILE__, __LINE__, tp); \ 400 panic("tcp reass lock check"); \ 401 } \ 402 } while (/*CONSTCOND*/ 0) 403 #else 404 #define TCP_REASS_LOCK(tp) (void) tcp_reass_lock_try((tp)) 405 #define TCP_REASS_LOCK_CHECK(tp) /* nothing */ 406 #endif 407 408 #define TCP_REASS_UNLOCK(tp) tcp_reass_unlock((tp)) 409 #endif /* _KERNEL */ 410 411 /* 412 * Queue for delayed ACK processing. 413 */ 414 #ifdef _KERNEL 415 extern int tcp_delack_ticks; 416 void tcp_delack(void *); 417 418 #define TCP_RESTART_DELACK(tp) \ 419 callout_reset(&(tp)->t_delack_ch, tcp_delack_ticks, \ 420 tcp_delack, tp) 421 422 #define TCP_SET_DELACK(tp) \ 423 do { \ 424 if (((tp)->t_flags & TF_DELACK) == 0) { \ 425 (tp)->t_flags |= TF_DELACK; \ 426 TCP_RESTART_DELACK(tp); \ 427 } \ 428 } while (/*CONSTCOND*/0) 429 430 #define TCP_CLEAR_DELACK(tp) \ 431 do { \ 432 if ((tp)->t_flags & TF_DELACK) { \ 433 (tp)->t_flags &= ~TF_DELACK; \ 434 callout_stop(&(tp)->t_delack_ch); \ 435 } \ 436 } while (/*CONSTCOND*/0) 437 #endif /* _KERNEL */ 438 439 /* 440 * Compute the current timestamp for a connection. 441 */ 442 #define TCP_TIMESTAMP(tp) (tcp_now - (tp)->ts_timebase) 443 444 /* 445 * Handy way of passing around TCP option info. 446 */ 447 struct tcp_opt_info { 448 int ts_present; 449 u_int32_t ts_val; 450 u_int32_t ts_ecr; 451 u_int16_t maxseg; 452 }; 453 454 #define TOF_SIGNATURE 0x0040 /* signature option present */ 455 #define TOF_SIGLEN 0x0080 /* sigature length valid (RFC2385) */ 456 457 /* 458 * Data for the TCP compressed state engine. 459 */ 460 union syn_cache_sa { 461 struct sockaddr sa; 462 struct sockaddr_in sin; 463 #if 1 /*def INET6*/ 464 struct sockaddr_in6 sin6; 465 #endif 466 }; 467 468 struct syn_cache { 469 TAILQ_ENTRY(syn_cache) sc_bucketq; /* link on bucket list */ 470 struct callout sc_timer; /* rexmt timer */ 471 union { /* cached route */ 472 struct route route4; 473 #ifdef INET6 474 struct route_in6 route6; 475 #endif 476 } sc_route_u; 477 #define sc_route4 sc_route_u.route4 478 #ifdef INET6 479 #define sc_route6 sc_route_u.route6 480 #endif 481 long sc_win; /* advertised window */ 482 int sc_bucketidx; /* our bucket index */ 483 u_int32_t sc_hash; 484 u_int32_t sc_timestamp; /* timestamp from SYN */ 485 u_int32_t sc_timebase; /* our local timebase */ 486 union syn_cache_sa sc_src; 487 union syn_cache_sa sc_dst; 488 tcp_seq sc_irs; 489 tcp_seq sc_iss; 490 u_int sc_rxtcur; /* current rxt timeout */ 491 u_int sc_rxttot; /* total time spend on queues */ 492 u_short sc_rxtshift; /* for computing backoff */ 493 u_short sc_flags; 494 495 #define SCF_UNREACH 0x0001 /* we've had an unreach error */ 496 #define SCF_TIMESTAMP 0x0002 /* peer will do timestamps */ 497 #define SCF_DEAD 0x0004 /* this entry to be released */ 498 #define SCF_SACK_PERMIT 0x0008 /* peer will do SACK */ 499 #define SCF_ECN_PERMIT 0x0010 /* peer will do ECN */ 500 #define SCF_SIGNATURE 0x40 /* send MD5 digests */ 501 502 struct mbuf *sc_ipopts; /* IP options */ 503 u_int16_t sc_peermaxseg; 504 u_int16_t sc_ourmaxseg; 505 u_int8_t sc_request_r_scale : 4, 506 sc_requested_s_scale : 4; 507 508 struct tcpcb *sc_tp; /* tcb for listening socket */ 509 LIST_ENTRY(syn_cache) sc_tpq; /* list of entries by same tp */ 510 }; 511 512 struct syn_cache_head { 513 TAILQ_HEAD(, syn_cache) sch_bucket; /* bucket entries */ 514 u_short sch_length; /* # entries in bucket */ 515 }; 516 517 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 518 #ifdef INET6 519 #define in6totcpcb(ip) ((struct tcpcb *)(ip)->in6p_ppcb) 520 #endif 521 #ifndef INET6 522 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 523 #else 524 #define sototcpcb(so) (((so)->so_proto->pr_domain->dom_family == AF_INET) \ 525 ? intotcpcb(sotoinpcb(so)) \ 526 : in6totcpcb(sotoin6pcb(so))) 527 #endif 528 529 /* 530 * The smoothed round-trip time and estimated variance 531 * are stored as fixed point numbers scaled by the values below. 532 * For convenience, these scales are also used in smoothing the average 533 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 534 * With these scales, srtt has 3 bits to the right of the binary point, 535 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the 536 * binary point, and is smoothed with an ALPHA of 0.75. 537 */ 538 #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ 539 #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */ 540 541 /* 542 * The initial retransmission should happen at rtt + 4 * rttvar. 543 * Because of the way we do the smoothing, srtt and rttvar 544 * will each average +1/2 tick of bias. When we compute 545 * the retransmit timer, we want 1/2 tick of rounding and 546 * 1 extra tick because of +-1/2 tick uncertainty in the 547 * firing of the timer. The bias will give us exactly the 548 * 1.5 tick we need. But, because the bias is 549 * statistical, we have to test that we don't drop below 550 * the minimum feasible timer (which is 2 ticks). 551 * This macro assumes that the value of 1<<TCP_RTTVAR_SHIFT 552 * is the same as the multiplier for rttvar. 553 */ 554 #define TCP_REXMTVAL(tp) \ 555 ((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) >> 2) 556 557 /* 558 * Compute the initial window for slow start. 559 */ 560 #define TCP_INITIAL_WINDOW(iw, segsz) \ 561 (((iw) == 0) ? (min(4 * (segsz), max(2 * (segsz), 4380))) : \ 562 ((segsz) * (iw))) 563 564 /* 565 * TCP statistics. 566 * Many of these should be kept per connection, 567 * but that's inconvenient at the moment. 568 */ 569 struct tcpstat { 570 u_quad_t tcps_connattempt; /* connections initiated */ 571 u_quad_t tcps_accepts; /* connections accepted */ 572 u_quad_t tcps_connects; /* connections established */ 573 u_quad_t tcps_drops; /* connections dropped */ 574 u_quad_t tcps_conndrops; /* embryonic connections dropped */ 575 u_quad_t tcps_closed; /* conn. closed (includes drops) */ 576 u_quad_t tcps_segstimed; /* segs where we tried to get rtt */ 577 u_quad_t tcps_rttupdated; /* times we succeeded */ 578 u_quad_t tcps_delack; /* delayed acks sent */ 579 u_quad_t tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ 580 u_quad_t tcps_rexmttimeo; /* retransmit timeouts */ 581 u_quad_t tcps_persisttimeo; /* persist timeouts */ 582 u_quad_t tcps_keeptimeo; /* keepalive timeouts */ 583 u_quad_t tcps_keepprobe; /* keepalive probes sent */ 584 u_quad_t tcps_keepdrops; /* connections dropped in keepalive */ 585 u_quad_t tcps_persistdrops; /* connections dropped in persist */ 586 u_quad_t tcps_connsdrained; /* connections drained due to memory 587 shortage */ 588 u_quad_t tcps_pmtublackhole; /* PMTUD blackhole detected */ 589 590 u_quad_t tcps_sndtotal; /* total packets sent */ 591 u_quad_t tcps_sndpack; /* data packets sent */ 592 u_quad_t tcps_sndbyte; /* data bytes sent */ 593 u_quad_t tcps_sndrexmitpack; /* data packets retransmitted */ 594 u_quad_t tcps_sndrexmitbyte; /* data bytes retransmitted */ 595 u_quad_t tcps_sndacks; /* ack-only packets sent */ 596 u_quad_t tcps_sndprobe; /* window probes sent */ 597 u_quad_t tcps_sndurg; /* packets sent with URG only */ 598 u_quad_t tcps_sndwinup; /* window update-only packets sent */ 599 u_quad_t tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ 600 601 u_quad_t tcps_rcvtotal; /* total packets received */ 602 u_quad_t tcps_rcvpack; /* packets received in sequence */ 603 u_quad_t tcps_rcvbyte; /* bytes received in sequence */ 604 u_quad_t tcps_rcvbadsum; /* packets received with ccksum errs */ 605 u_quad_t tcps_rcvbadoff; /* packets received with bad offset */ 606 u_quad_t tcps_rcvmemdrop; /* packets dropped for lack of memory */ 607 u_quad_t tcps_rcvshort; /* packets received too short */ 608 u_quad_t tcps_rcvduppack; /* duplicate-only packets received */ 609 u_quad_t tcps_rcvdupbyte; /* duplicate-only bytes received */ 610 u_quad_t tcps_rcvpartduppack; /* packets with some duplicate data */ 611 u_quad_t tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ 612 u_quad_t tcps_rcvoopack; /* out-of-order packets received */ 613 u_quad_t tcps_rcvoobyte; /* out-of-order bytes received */ 614 u_quad_t tcps_rcvpackafterwin; /* packets with data after window */ 615 u_quad_t tcps_rcvbyteafterwin; /* bytes rcvd after window */ 616 u_quad_t tcps_rcvafterclose; /* packets rcvd after "close" */ 617 u_quad_t tcps_rcvwinprobe; /* rcvd window probe packets */ 618 u_quad_t tcps_rcvdupack; /* rcvd duplicate acks */ 619 u_quad_t tcps_rcvacktoomuch; /* rcvd acks for unsent data */ 620 u_quad_t tcps_rcvackpack; /* rcvd ack packets */ 621 u_quad_t tcps_rcvackbyte; /* bytes acked by rcvd acks */ 622 u_quad_t tcps_rcvwinupd; /* rcvd window update packets */ 623 u_quad_t tcps_pawsdrop; /* segments dropped due to PAWS */ 624 u_quad_t tcps_predack; /* times hdr predict ok for acks */ 625 u_quad_t tcps_preddat; /* times hdr predict ok for data pkts */ 626 627 u_quad_t tcps_pcbhashmiss; /* input packets missing pcb hash */ 628 u_quad_t tcps_noport; /* no socket on port */ 629 u_quad_t tcps_badsyn; /* received ack for which we have 630 no SYN in compressed state */ 631 u_quad_t tcps_delayed_free; /* delayed pool_put() of tcpcb */ 632 633 /* These statistics deal with the SYN cache. */ 634 u_quad_t tcps_sc_added; /* # of entries added */ 635 u_quad_t tcps_sc_completed; /* # of connections completed */ 636 u_quad_t tcps_sc_timed_out; /* # of entries timed out */ 637 u_quad_t tcps_sc_overflowed; /* # dropped due to overflow */ 638 u_quad_t tcps_sc_reset; /* # dropped due to RST */ 639 u_quad_t tcps_sc_unreach; /* # dropped due to ICMP unreach */ 640 u_quad_t tcps_sc_bucketoverflow;/* # dropped due to bucket overflow */ 641 u_quad_t tcps_sc_aborted; /* # of entries aborted (no mem) */ 642 u_quad_t tcps_sc_dupesyn; /* # of duplicate SYNs received */ 643 u_quad_t tcps_sc_dropped; /* # of SYNs dropped (no route/mem) */ 644 u_quad_t tcps_sc_collisions; /* # of hash collisions */ 645 u_quad_t tcps_sc_retransmitted; /* # of retransmissions */ 646 u_quad_t tcps_sc_delayed_free; /* # of delayed pool_put()s */ 647 648 u_quad_t tcps_selfquench; /* # of ENOBUFS we get on output */ 649 u_quad_t tcps_badsig; /* # of drops due to bad signature */ 650 u_quad_t tcps_goodsig; /* # of packets with good signature */ 651 652 u_quad_t tcps_ecn_shs; /* # of sucessful ECN handshakes */ 653 u_quad_t tcps_ecn_ce; /* # of packets with CE bit */ 654 u_quad_t tcps_ecn_ect; /* # of packets with ECT(0) bit */ 655 }; 656 657 /* 658 * Names for TCP sysctl objects. 659 */ 660 #define TCPCTL_RFC1323 1 /* RFC1323 timestamps/scaling */ 661 #define TCPCTL_SENDSPACE 2 /* default send buffer */ 662 #define TCPCTL_RECVSPACE 3 /* default recv buffer */ 663 #define TCPCTL_MSSDFLT 4 /* default seg size */ 664 #define TCPCTL_SYN_CACHE_LIMIT 5 /* max size of comp. state engine */ 665 #define TCPCTL_SYN_BUCKET_LIMIT 6 /* max size of hash bucket */ 666 #if 0 /*obsoleted*/ 667 #define TCPCTL_SYN_CACHE_INTER 7 /* interval of comp. state timer */ 668 #endif 669 #define TCPCTL_INIT_WIN 8 /* initial window */ 670 #define TCPCTL_MSS_IFMTU 9 /* mss from interface, not in_maxmtu */ 671 #define TCPCTL_SACK 10 /* RFC2018 selective acknowledgement */ 672 #define TCPCTL_WSCALE 11 /* RFC1323 window scaling */ 673 #define TCPCTL_TSTAMP 12 /* RFC1323 timestamps */ 674 #define TCPCTL_COMPAT_42 13 /* 4.2BSD TCP bug work-arounds */ 675 #define TCPCTL_CWM 14 /* Congestion Window Monitoring */ 676 #define TCPCTL_CWM_BURSTSIZE 15 /* burst size allowed by CWM */ 677 #define TCPCTL_ACK_ON_PUSH 16 /* ACK immediately on PUSH */ 678 #define TCPCTL_KEEPIDLE 17 /* keepalive idle time */ 679 #define TCPCTL_KEEPINTVL 18 /* keepalive probe interval */ 680 #define TCPCTL_KEEPCNT 19 /* keepalive count */ 681 #define TCPCTL_SLOWHZ 20 /* PR_SLOWHZ (read-only) */ 682 #define TCPCTL_NEWRENO 21 /* NewReno Congestion Control */ 683 #define TCPCTL_LOG_REFUSED 22 /* Log refused connections */ 684 #if 0 /*obsoleted*/ 685 #define TCPCTL_RSTRATELIMIT 23 /* RST rate limit */ 686 #endif 687 #define TCPCTL_RSTPPSLIMIT 24 /* RST pps limit */ 688 #define TCPCTL_DELACK_TICKS 25 /* # ticks to delay ACK */ 689 #define TCPCTL_INIT_WIN_LOCAL 26 /* initial window for local nets */ 690 #define TCPCTL_IDENT 27 /* rfc 931 identd */ 691 #define TCPCTL_ACKDROPRATELIMIT 28 /* SYN/RST -> ACK rate limit */ 692 #define TCPCTL_LOOPBACKCKSUM 29 /* do TCP checksum on loopback */ 693 #define TCPCTL_STATS 30 /* TCP statistics */ 694 #define TCPCTL_DEBUG 31 /* TCP debug sockets */ 695 #define TCPCTL_DEBX 32 /* # of tcp debug sockets */ 696 #define TCPCTL_MAXID 33 697 698 #define TCPCTL_NAMES { \ 699 { 0, 0 }, \ 700 { "rfc1323", CTLTYPE_INT }, \ 701 { "sendspace", CTLTYPE_INT }, \ 702 { "recvspace", CTLTYPE_INT }, \ 703 { "mssdflt", CTLTYPE_INT }, \ 704 { "syn_cache_limit", CTLTYPE_INT }, \ 705 { "syn_bucket_limit", CTLTYPE_INT }, \ 706 { 0, 0 },\ 707 { "init_win", CTLTYPE_INT }, \ 708 { "mss_ifmtu", CTLTYPE_INT }, \ 709 { "sack", CTLTYPE_INT }, \ 710 { "win_scale", CTLTYPE_INT }, \ 711 { "timestamps", CTLTYPE_INT }, \ 712 { "compat_42", CTLTYPE_INT }, \ 713 { "cwm", CTLTYPE_INT }, \ 714 { "cwm_burstsize", CTLTYPE_INT }, \ 715 { "ack_on_push", CTLTYPE_INT }, \ 716 { "keepidle", CTLTYPE_INT }, \ 717 { "keepintvl", CTLTYPE_INT }, \ 718 { "keepcnt", CTLTYPE_INT }, \ 719 { "slowhz", CTLTYPE_INT }, \ 720 { 0, 0 }, \ 721 { "log_refused",CTLTYPE_INT }, \ 722 { 0, 0 }, \ 723 { "rstppslimit", CTLTYPE_INT }, \ 724 { "delack_ticks", CTLTYPE_INT }, \ 725 { "init_win_local", CTLTYPE_INT }, \ 726 { "ident", CTLTYPE_STRUCT }, \ 727 { "ackdropppslimit", CTLTYPE_INT }, \ 728 { "do_loopback_cksum", CTLTYPE_INT }, \ 729 { "stats", CTLTYPE_STRUCT }, \ 730 { "debug", CTLTYPE_STRUCT }, \ 731 { "debx", CTLTYPE_INT }, \ 732 } 733 734 #ifdef _KERNEL 735 extern struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 736 extern struct tcpstat tcpstat; /* tcp statistics */ 737 extern u_int32_t tcp_now; /* for RFC 1323 timestamps */ 738 extern int tcp_do_rfc1323; /* enabled/disabled? */ 739 extern int tcp_do_sack; /* SACK enabled/disabled? */ 740 extern int tcp_do_win_scale; /* RFC1323 window scaling enabled/disabled? */ 741 extern int tcp_do_timestamps; /* RFC1323 timestamps enabled/disabled? */ 742 extern int tcp_mssdflt; /* default seg size */ 743 extern int tcp_init_win; /* initial window */ 744 extern int tcp_init_win_local; /* initial window for local nets */ 745 extern int tcp_mss_ifmtu; /* take MSS from interface, not in_maxmtu */ 746 extern int tcp_compat_42; /* work around ancient broken TCP peers */ 747 extern int tcp_cwm; /* enable Congestion Window Monitoring */ 748 extern int tcp_cwm_burstsize; /* burst size allowed by CWM */ 749 extern int tcp_ack_on_push; /* ACK immediately on PUSH */ 750 extern int tcp_syn_cache_limit; /* max entries for compressed state engine */ 751 extern int tcp_syn_bucket_limit;/* max entries per hash bucket */ 752 extern int tcp_log_refused; /* log refused connections */ 753 extern int tcp_do_ecn; /* TCP ECN enabled/disabled? */ 754 extern int tcp_ecn_maxretries; /* Max ECN setup retries */ 755 #if NRND > 0 756 extern int tcp_do_rfc1948; /* ISS by cryptographic hash */ 757 #endif 758 extern int tcp_sack_tp_maxholes; /* Max holes per connection. */ 759 extern int tcp_sack_globalmaxholes; /* Max holes per system. */ 760 extern int tcp_sack_globalholes; /* Number of holes present. */ 761 762 extern int tcp_rst_ppslim; 763 extern int tcp_ackdrop_ppslim; 764 765 extern int tcp_syn_cache_size; 766 extern struct syn_cache_head tcp_syn_cache[]; 767 extern u_long syn_cache_count; 768 769 #ifdef MBUFTRACE 770 extern struct mowner tcp_rx_mowner; 771 extern struct mowner tcp_tx_mowner; 772 extern struct mowner tcp_mowner; 773 #endif 774 775 #define TCPCTL_VARIABLES { \ 776 { 0 }, \ 777 { 1, 0, &tcp_do_rfc1323 }, \ 778 { 1, 0, &tcp_sendspace }, \ 779 { 1, 0, &tcp_recvspace }, \ 780 { 1, 0, &tcp_mssdflt }, \ 781 { 1, 0, &tcp_syn_cache_limit }, \ 782 { 1, 0, &tcp_syn_bucket_limit }, \ 783 { 0 }, \ 784 { 1, 0, &tcp_init_win }, \ 785 { 1, 0, &tcp_mss_ifmtu }, \ 786 { 1, 0, &tcp_do_sack }, \ 787 { 1, 0, &tcp_do_win_scale }, \ 788 { 1, 0, &tcp_do_timestamps }, \ 789 { 1, 0, &tcp_compat_42 }, \ 790 { 1, 0, &tcp_cwm }, \ 791 { 1, 0, &tcp_cwm_burstsize }, \ 792 { 1, 0, &tcp_ack_on_push }, \ 793 { 1, 0, &tcp_keepidle }, \ 794 { 1, 0, &tcp_keepintvl }, \ 795 { 1, 0, &tcp_keepcnt }, \ 796 { 1, 1, 0, PR_SLOWHZ }, \ 797 { 0 }, \ 798 { 1, 0, &tcp_log_refused }, \ 799 { 0 }, \ 800 { 1, 0, &tcp_rst_ppslim }, \ 801 { 1, 0, &tcp_delack_ticks }, \ 802 { 1, 0, &tcp_init_win_local }, \ 803 { 1, 0, &tcp_ackdrop_ppslim }, \ 804 } 805 806 #ifdef __NO_STRICT_ALIGNMENT 807 #define TCP_HDR_ALIGNED_P(th) 1 808 #else 809 #define TCP_HDR_ALIGNED_P(th) ((((vaddr_t)(th)) & 3) == 0) 810 #endif 811 812 struct secasvar; 813 814 int tcp_attach(struct socket *); 815 void tcp_canceltimers(struct tcpcb *); 816 int tcp_timers_invoking(struct tcpcb*); 817 struct tcpcb * 818 tcp_close(struct tcpcb *); 819 int tcp_isdead(struct tcpcb *); 820 #ifdef INET6 821 void tcp6_ctlinput(int, struct sockaddr *, void *); 822 #endif 823 void *tcp_ctlinput(int, struct sockaddr *, void *); 824 int tcp_ctloutput(int, struct socket *, int, int, struct mbuf **); 825 struct tcpcb * 826 tcp_disconnect(struct tcpcb *); 827 struct tcpcb * 828 tcp_drop(struct tcpcb *, int); 829 #ifdef TCP_SIGNATURE 830 int tcp_signature_apply(void *, caddr_t, u_int); 831 struct secasvar *tcp_signature_getsav(struct mbuf *, struct tcphdr *); 832 int tcp_signature(struct mbuf *, struct tcphdr *, int, struct secasvar *, 833 char *); 834 #endif 835 int tcp_dooptions(struct tcpcb *, u_char *, int, struct tcphdr *, 836 struct mbuf *, int, struct tcp_opt_info *); 837 void tcp_drain(void); 838 void tcp_established(struct tcpcb *); 839 void tcp_init(void); 840 #ifdef INET6 841 int tcp6_input(struct mbuf **, int *, int); 842 #endif 843 void tcp_input(struct mbuf *, ...); 844 u_int tcp_hdrsz(struct tcpcb *); 845 u_long tcp_mss_to_advertise(const struct ifnet *, int); 846 void tcp_mss_from_peer(struct tcpcb *, int); 847 void tcp_tcpcb_template(void); 848 struct tcpcb * 849 tcp_newtcpcb(int, void *); 850 void tcp_notify(struct inpcb *, int); 851 #ifdef INET6 852 void tcp6_notify(struct in6pcb *, int); 853 #endif 854 u_int tcp_optlen(struct tcpcb *); 855 int tcp_output(struct tcpcb *); 856 void tcp_pulloutofband(struct socket *, 857 struct tcphdr *, struct mbuf *, int); 858 void tcp_quench(struct inpcb *, int); 859 #ifdef INET6 860 void tcp6_quench(struct in6pcb *, int); 861 #endif 862 void tcp_mtudisc(struct inpcb *, int); 863 864 struct ipqent *tcpipqent_alloc(void); 865 void tcpipqent_free(struct ipqent *); 866 867 int tcp_reass(struct tcpcb *, struct tcphdr *, struct mbuf *, int *); 868 int tcp_respond(struct tcpcb *, struct mbuf *, struct mbuf *, 869 struct tcphdr *, tcp_seq, tcp_seq, int); 870 void tcp_rmx_rtt(struct tcpcb *); 871 void tcp_setpersist(struct tcpcb *); 872 #ifdef TCP_SIGNATURE 873 int tcp_signature_compute(struct mbuf *, struct tcphdr *, int, int, 874 int, u_char *, u_int); 875 #endif 876 void tcp_slowtimo(void); 877 struct mbuf * 878 tcp_template(struct tcpcb *); 879 void tcp_trace(short, short, struct tcpcb *, struct mbuf *, int); 880 struct tcpcb * 881 tcp_usrclosed(struct tcpcb *); 882 int tcp_usrreq(struct socket *, 883 int, struct mbuf *, struct mbuf *, struct mbuf *, struct lwp *); 884 void tcp_xmit_timer(struct tcpcb *, uint32_t); 885 tcp_seq tcp_new_iss(struct tcpcb *, tcp_seq); 886 tcp_seq tcp_new_iss1(void *, void *, u_int16_t, u_int16_t, size_t, 887 tcp_seq); 888 889 void tcp_new_dsack(struct tcpcb *, tcp_seq, u_int32_t); 890 void tcp_sack_option(struct tcpcb *, struct tcphdr *, u_char *, int); 891 void tcp_del_sackholes(struct tcpcb *, struct tcphdr *); 892 void tcp_free_sackholes(struct tcpcb *); 893 void tcp_sack_adjust(struct tcpcb *tp); 894 struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt); 895 void tcp_sack_newack(struct tcpcb *, struct tcphdr *); 896 int tcp_sack_numblks(const struct tcpcb *); 897 #define TCP_SACK_OPTLEN(nblks) ((nblks) * 8 + 2 + 2) 898 899 int syn_cache_add(struct sockaddr *, struct sockaddr *, 900 struct tcphdr *, unsigned int, struct socket *, 901 struct mbuf *, u_char *, int, struct tcp_opt_info *); 902 void syn_cache_unreach(const struct sockaddr *, const struct sockaddr *, 903 struct tcphdr *); 904 struct socket *syn_cache_get(struct sockaddr *, struct sockaddr *, 905 struct tcphdr *, unsigned int, unsigned int, 906 struct socket *so, struct mbuf *); 907 void syn_cache_init(void); 908 void syn_cache_insert(struct syn_cache *, struct tcpcb *); 909 struct syn_cache *syn_cache_lookup(const struct sockaddr *, const struct sockaddr *, 910 struct syn_cache_head **); 911 void syn_cache_reset(struct sockaddr *, struct sockaddr *, 912 struct tcphdr *); 913 int syn_cache_respond(struct syn_cache *, struct mbuf *); 914 void syn_cache_timer(void *); 915 void syn_cache_cleanup(struct tcpcb *); 916 917 int tcp_input_checksum(int, struct mbuf *, const struct tcphdr *, int, int, 918 int); 919 #endif 920 921 #endif /* !_NETINET_TCP_VAR_H_ */ 922
Indexes created Sun Sep 28 12:09:53 GMT 2025