1 /* $NetBSD: tcp_var.h,v 1.199 2024/12/03 20:02:30 andvar Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * @(#)COPYRIGHT 1.1 (NRL) 17 January 1995 34 * 35 * NRL grants permission for redistribution and use in source and binary 36 * forms, with or without modification, of the software and documentation 37 * created at NRL provided that the following conditions are met: 38 * 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 3. All advertising materials mentioning features or use of this software 45 * must display the following acknowledgements: 46 * This product includes software developed by the University of 47 * California, Berkeley and its contributors. 48 * This product includes software developed at the Information 49 * Technology Division, US Naval Research Laboratory. 50 * 4. Neither the name of the NRL nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS 55 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 56 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 57 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL NRL OR 58 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 59 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 60 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 61 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 62 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 63 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 64 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 65 * 66 * The views and conclusions contained in the software and documentation 67 * are those of the authors and should not be interpreted as representing 68 * official policies, either expressed or implied, of the US Naval 69 * Research Laboratory (NRL). 70 */ 71 72 /*- 73 * Copyright (c) 1997, 1998, 1999, 2001, 2005 The NetBSD Foundation, Inc. 74 * All rights reserved. 75 * 76 * This code is derived from software contributed to The NetBSD Foundation 77 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 78 * NASA Ames Research Center. 79 * This code is derived from software contributed to The NetBSD Foundation 80 * by Charles M. Hannum. 81 * 82 * Redistribution and use in source and binary forms, with or without 83 * modification, are permitted provided that the following conditions 84 * are met: 85 * 1. Redistributions of source code must retain the above copyright 86 * notice, this list of conditions and the following disclaimer. 87 * 2. Redistributions in binary form must reproduce the above copyright 88 * notice, this list of conditions and the following disclaimer in the 89 * documentation and/or other materials provided with the distribution. 90 * 91 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 92 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 93 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 94 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 95 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 96 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 97 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 98 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 99 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 100 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 101 * POSSIBILITY OF SUCH DAMAGE. 102 */ 103 104 /* 105 * Copyright (c) 1982, 1986, 1993, 1994, 1995 106 * The Regents of the University of California. All rights reserved. 107 * 108 * Redistribution and use in source and binary forms, with or without 109 * modification, are permitted provided that the following conditions 110 * are met: 111 * 1. Redistributions of source code must retain the above copyright 112 * notice, this list of conditions and the following disclaimer. 113 * 2. Redistributions in binary form must reproduce the above copyright 114 * notice, this list of conditions and the following disclaimer in the 115 * documentation and/or other materials provided with the distribution. 116 * 3. Neither the name of the University nor the names of its contributors 117 * may be used to endorse or promote products derived from this software 118 * without specific prior written permission. 119 * 120 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 121 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 122 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 123 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 124 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 125 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 126 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 127 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 128 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 129 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 130 * SUCH DAMAGE. 131 * 132 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95 133 */ 134 135 #ifndef _NETINET_TCP_VAR_H_ 136 #define _NETINET_TCP_VAR_H_ 137 138 #if defined(_KERNEL_OPT) 139 #include "opt_inet.h" 140 #include "opt_mbuftrace.h" 141 142 #endif 143 144 /* 145 * TCP kernel structures and variables. 146 */ 147 148 #include <sys/callout.h> 149 150 #ifdef TCP_SIGNATURE 151 /* 152 * Defines which are needed by the xform_tcp module and tcp_[in|out]put 153 * for SADB verification and lookup. 154 */ 155 #define TCP_SIGLEN 16 /* length of computed digest in bytes */ 156 #define TCP_KEYLEN_MIN 1 /* minimum length of TCP-MD5 key */ 157 #define TCP_KEYLEN_MAX 80 /* maximum length of TCP-MD5 key */ 158 /* 159 * Only a single SA per host may be specified at this time. An SPI is 160 * needed in order for the KEY_LOOKUP_SA() lookup to work. 161 */ 162 #define TCP_SIG_SPI 0x1000 163 #endif /* TCP_SIGNATURE */ 164 165 /* 166 * Tcp+ip header, after ip options removed. 167 */ 168 struct tcpiphdr { 169 struct ipovly ti_i; /* overlaid ip structure */ 170 struct tcphdr ti_t; /* tcp header */ 171 }; 172 #ifdef CTASSERT 173 CTASSERT(sizeof(struct tcpiphdr) == 40); 174 #endif 175 #define ti_x1 ti_i.ih_x1 176 #define ti_pr ti_i.ih_pr 177 #define ti_len ti_i.ih_len 178 #define ti_src ti_i.ih_src 179 #define ti_dst ti_i.ih_dst 180 #define ti_sport ti_t.th_sport 181 #define ti_dport ti_t.th_dport 182 #define ti_seq ti_t.th_seq 183 #define ti_ack ti_t.th_ack 184 #define ti_x2 ti_t.th_x2 185 #define ti_off ti_t.th_off 186 #define ti_flags ti_t.th_flags 187 #define ti_win ti_t.th_win 188 #define ti_sum ti_t.th_sum 189 #define ti_urp ti_t.th_urp 190 191 /* 192 * SACK option block. 193 */ 194 struct sackblk { 195 tcp_seq left; /* Left edge of sack block. */ 196 tcp_seq right; /* Right edge of sack block. */ 197 }; 198 199 TAILQ_HEAD(sackhead, sackhole); 200 struct sackhole { 201 tcp_seq start; 202 tcp_seq end; 203 tcp_seq rxmit; 204 205 TAILQ_ENTRY(sackhole) sackhole_q; 206 }; 207 208 struct syn_cache; 209 210 /* 211 * Tcp control block, one per tcp; fields: 212 */ 213 struct tcpcb { 214 int t_family; /* address family on the wire */ 215 struct ipqehead segq; /* sequencing queue */ 216 int t_segqlen; /* length of the above */ 217 callout_t t_timer[TCPT_NTIMERS];/* tcp timers */ 218 short t_state; /* state of this connection */ 219 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 220 uint32_t t_rxtcur; /* current retransmit value */ 221 short t_dupacks; /* consecutive dup acks recd */ 222 /* 223 * t_partialacks: 224 * <0 not in fast recovery. 225 * ==0 in fast recovery. has not received partial acks 226 * >0 in fast recovery. has received partial acks 227 */ 228 short t_partialacks; /* partials acks during fast rexmit */ 229 u_short t_peermss; /* peer's maximum segment size */ 230 u_short t_ourmss; /* our's maximum segment size */ 231 u_short t_segsz; /* current segment size in use */ 232 char t_force; /* 1 if forcing out a byte */ 233 u_int t_flags; 234 #define TF_ACKNOW 0x0001 /* ack peer immediately */ 235 #define TF_DELACK 0x0002 /* ack, but try to delay it */ 236 #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */ 237 #define TF_NOOPT 0x0008 /* don't use tcp options */ 238 #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */ 239 #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */ 240 #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */ 241 #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */ 242 #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */ 243 #define TF_SYN_REXMT 0x0400 /* rexmit timer fired on SYN */ 244 #define TF_WILL_SACK 0x0800 /* try to use SACK */ 245 #define TF_REASSEMBLING 0x1000 /* we're busy reassembling */ 246 #define TF_DEAD 0x2000 /* dead and to-be-released */ 247 #define TF_PMTUD_PEND 0x4000 /* Path MTU Discovery pending */ 248 #define TF_ECN_PERMIT 0x10000 /* other side said is ECN-ready */ 249 #define TF_ECN_SND_CWR 0x20000 /* ECN CWR in queue */ 250 #define TF_ECN_SND_ECE 0x40000 /* ECN ECE in queue */ 251 #define TF_SIGNATURE 0x400000 /* require MD5 digests (RFC2385) */ 252 253 254 struct mbuf *t_template; /* skeletal packet for transmit */ 255 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 256 callout_t t_delack_ch; /* delayed ACK callout */ 257 /* 258 * The following fields are used as in the protocol specification. 259 * See RFC793, Dec. 1981, page 21. 260 */ 261 /* send sequence variables */ 262 tcp_seq snd_una; /* send unacknowledged */ 263 tcp_seq snd_nxt; /* send next */ 264 tcp_seq snd_up; /* send urgent pointer */ 265 tcp_seq snd_wl1; /* window update seg seq number */ 266 tcp_seq snd_wl2; /* window update seg ack number */ 267 tcp_seq iss; /* initial send sequence number */ 268 u_long snd_wnd; /* send window */ 269 /* 270 * snd_recover 271 * it's basically same as the "recover" variable in RFC 2852 (NewReno). 272 * when entering fast retransmit, it's set to snd_max. 273 * newreno uses this to detect partial ack. 274 * snd_high 275 * it's basically same as the "send_high" variable in RFC 2852 (NewReno). 276 * on each RTO, it's set to snd_max. 277 * newreno uses this to avoid false fast retransmits. 278 */ 279 tcp_seq snd_recover; 280 tcp_seq snd_high; 281 /* receive sequence variables */ 282 u_long rcv_wnd; /* receive window */ 283 tcp_seq rcv_nxt; /* receive next */ 284 tcp_seq rcv_up; /* receive urgent pointer */ 285 tcp_seq irs; /* initial receive sequence number */ 286 /* 287 * Additional variables for this implementation. 288 */ 289 /* receive variables */ 290 tcp_seq rcv_adv; /* advertised window */ 291 292 /* 293 * retransmit variables 294 * 295 * snd_max 296 * the highest sequence number we've ever sent. 297 * used to recognize retransmits. 298 */ 299 tcp_seq snd_max; 300 301 /* congestion control (for slow start, source quench, retransmit after loss) */ 302 u_long snd_cwnd; /* congestion-controlled window */ 303 u_long snd_ssthresh; /* snd_cwnd size threshold for 304 * for slow start exponential to 305 * linear switch 306 */ 307 /* auto-sizing variables */ 308 u_int rfbuf_cnt; /* recv buffer autoscaling byte count */ 309 uint32_t rfbuf_ts; /* recv buffer autoscaling timestamp */ 310 311 /* 312 * transmit timing stuff. See below for scale of srtt and rttvar. 313 * "Variance" is actually smoothed difference. 314 */ 315 uint32_t t_rcvtime; /* time last segment received */ 316 uint32_t t_rtttime; /* time we started measuring rtt */ 317 tcp_seq t_rtseq; /* sequence number being timed */ 318 int32_t t_srtt; /* smoothed round-trip time */ 319 int32_t t_rttvar; /* variance in round-trip time */ 320 uint32_t t_rttmin; /* minimum rtt allowed */ 321 u_long max_sndwnd; /* largest window peer has offered */ 322 323 /* out-of-band data */ 324 char t_oobflags; /* have some */ 325 char t_iobc; /* input character */ 326 #define TCPOOB_HAVEDATA 0x01 327 #define TCPOOB_HADDATA 0x02 328 short t_softerror; /* possible error not yet reported */ 329 330 /* RFC 1323 variables */ 331 u_char snd_scale; /* window scaling for send window */ 332 u_char rcv_scale; /* window scaling for recv window */ 333 u_char request_r_scale; /* pending window scaling */ 334 u_char requested_s_scale; 335 u_int32_t ts_recent; /* timestamp echo data */ 336 u_int32_t ts_recent_age; /* when last updated */ 337 u_int32_t ts_timebase; /* our timebase */ 338 tcp_seq last_ack_sent; 339 340 /* RFC 3465 variables */ 341 u_long t_bytes_acked; /* ABC "bytes_acked" parameter */ 342 343 /* SACK stuff */ 344 #define TCP_SACK_MAX 3 345 #define TCPSACK_NONE 0 346 #define TCPSACK_HAVED 1 347 u_char rcv_sack_flags; /* SACK flags. */ 348 struct sackblk rcv_dsack_block; /* RX D-SACK block. */ 349 struct ipqehead timeq; /* time sequenced queue. */ 350 struct sackhead snd_holes; /* TX SACK holes. */ 351 int snd_numholes; /* Number of TX SACK holes. */ 352 tcp_seq rcv_lastsack; /* last seq number(+1) sack'd by rcv'r*/ 353 tcp_seq sack_newdata; /* New data xmitted in this recovery 354 episode starts at this seq number*/ 355 tcp_seq snd_fack; /* FACK TCP. Forward-most data held by 356 peer. */ 357 358 /* CUBIC variables */ 359 ulong snd_cubic_wmax; /* W_max */ 360 ulong snd_cubic_wmax_last; /* Used for fast convergence */ 361 ulong snd_cubic_ctime; /* Last congestion time */ 362 363 /* pointer for syn cache entries*/ 364 LIST_HEAD(, syn_cache) t_sc; /* list of entries by this tcb */ 365 366 /* prediction of next mbuf when using large window sizes */ 367 struct mbuf *t_lastm; /* last mbuf that data was sent from */ 368 int t_inoff; /* data offset in previous mbuf */ 369 int t_lastoff; /* last data address in mbuf chain */ 370 int t_lastlen; /* last length read from mbuf chain */ 371 372 /* Path-MTU discovery blackhole detection */ 373 int t_mtudisc; /* perform mtudisc for this tcb */ 374 /* Path-MTU Discovery Information */ 375 u_int t_pmtud_mss_acked; /* MSS acked, lower bound for MTU */ 376 u_int t_pmtud_mtu_sent; /* MTU used, upper bound for MTU */ 377 tcp_seq t_pmtud_th_seq; /* TCP SEQ from ICMP payload */ 378 u_int t_pmtud_nextmtu; /* Advertised Next-Hop MTU from ICMP */ 379 u_short t_pmtud_ip_len; /* IP length from ICMP payload */ 380 u_short t_pmtud_ip_hl; /* IP header length from ICMP payload */ 381 382 uint8_t t_ecn_retries; /* # of ECN setup retries */ 383 384 const struct tcp_congctl *t_congctl; /* per TCB congctl algorithm */ 385 386 /* Keepalive per socket */ 387 u_int t_keepinit; 388 u_int t_keepidle; 389 u_int t_keepintvl; 390 u_int t_keepcnt; 391 u_int t_maxidle; /* t_keepcnt * t_keepintvl */ 392 393 u_int t_msl; /* MSL to use for this connexion */ 394 395 /* maintain a few stats per connection: */ 396 uint32_t t_rcvoopack; /* out-of-order packets received */ 397 uint32_t t_sndrexmitpack; /* retransmit packets sent */ 398 uint32_t t_sndzerowin; /* zero-window updates sent */ 399 }; 400 401 /* 402 * Macros to aid ECN TCP. 403 */ 404 #define TCP_ECN_ALLOWED(tp) (tp->t_flags & TF_ECN_PERMIT) 405 406 /* 407 * Macros to aid SACK/FACK TCP. 408 */ 409 #define TCP_SACK_ENABLED(tp) (tp->t_flags & TF_WILL_SACK) 410 #define TCP_FACK_FASTRECOV(tp) \ 411 (TCP_SACK_ENABLED(tp) && \ 412 (SEQ_GT(tp->snd_fack, tp->snd_una + tcprexmtthresh * tp->t_segsz))) 413 414 #ifdef _KERNEL 415 /* 416 * TCP reassembly queue locks. 417 */ 418 static __inline int tcp_reass_lock_try (struct tcpcb *) 419 __unused; 420 static __inline void tcp_reass_unlock (struct tcpcb *) 421 __unused; 422 423 static __inline int 424 tcp_reass_lock_try(struct tcpcb *tp) 425 { 426 int s; 427 428 /* 429 * Use splvm() -- we're blocking things that would cause 430 * mbuf allocation. 431 */ 432 s = splvm(); 433 if (tp->t_flags & TF_REASSEMBLING) { 434 splx(s); 435 return (0); 436 } 437 tp->t_flags |= TF_REASSEMBLING; 438 splx(s); 439 return (1); 440 } 441 442 static __inline void 443 tcp_reass_unlock(struct tcpcb *tp) 444 { 445 int s; 446 447 s = splvm(); 448 KASSERT((tp->t_flags & TF_REASSEMBLING) != 0); 449 tp->t_flags &= ~TF_REASSEMBLING; 450 splx(s); 451 } 452 453 #ifdef DIAGNOSTIC 454 #define TCP_REASS_LOCK(tp) \ 455 do { \ 456 if (tcp_reass_lock_try(tp) == 0) { \ 457 printf("%s:%d: tcpcb %p reass already locked\n", \ 458 __FILE__, __LINE__, tp); \ 459 panic("tcp_reass_lock"); \ 460 } \ 461 } while (/*CONSTCOND*/ 0) 462 #define TCP_REASS_LOCK_CHECK(tp) \ 463 do { \ 464 if (((tp)->t_flags & TF_REASSEMBLING) == 0) { \ 465 printf("%s:%d: tcpcb %p reass lock not held\n", \ 466 __FILE__, __LINE__, tp); \ 467 panic("tcp reass lock check"); \ 468 } \ 469 } while (/*CONSTCOND*/ 0) 470 #else 471 #define TCP_REASS_LOCK(tp) (void) tcp_reass_lock_try((tp)) 472 #define TCP_REASS_LOCK_CHECK(tp) /* nothing */ 473 #endif 474 475 #define TCP_REASS_UNLOCK(tp) tcp_reass_unlock((tp)) 476 #endif /* _KERNEL */ 477 478 /* 479 * Queue for delayed ACK processing. 480 */ 481 #ifdef _KERNEL 482 extern int tcp_delack_ticks; 483 void tcp_delack(void *); 484 485 #define TCP_RESTART_DELACK(tp) \ 486 callout_reset(&(tp)->t_delack_ch, tcp_delack_ticks, \ 487 tcp_delack, tp) 488 489 #define TCP_SET_DELACK(tp) \ 490 do { \ 491 if (((tp)->t_flags & TF_DELACK) == 0) { \ 492 (tp)->t_flags |= TF_DELACK; \ 493 TCP_RESTART_DELACK(tp); \ 494 } \ 495 } while (/*CONSTCOND*/0) 496 497 #define TCP_CLEAR_DELACK(tp) \ 498 do { \ 499 if ((tp)->t_flags & TF_DELACK) { \ 500 (tp)->t_flags &= ~TF_DELACK; \ 501 callout_stop(&(tp)->t_delack_ch); \ 502 } \ 503 } while (/*CONSTCOND*/0) 504 #endif /* _KERNEL */ 505 506 /* 507 * Compute the current timestamp for a connection. 508 */ 509 #define TCP_TIMESTAMP(tp) (tcp_now - (tp)->ts_timebase) 510 511 /* 512 * Handy way of passing around TCP option info. 513 */ 514 struct tcp_opt_info { 515 int ts_present; 516 u_int32_t ts_val; 517 u_int32_t ts_ecr; 518 u_int16_t maxseg; 519 }; 520 521 #define TOF_SIGNATURE 0x0040 /* signature option present */ 522 #define TOF_SIGLEN 0x0080 /* sigature length valid (RFC2385) */ 523 524 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 525 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 526 527 /* 528 * See RFC2988 for a discussion of RTO calculation; comments assume 529 * familiarity with that document. 530 * 531 * The smoothed round-trip time and estimated variance are stored as 532 * fixed point numbers. Historically, srtt was scaled by 533 * TCP_RTT_SHIFT bits, and rttvar by TCP_RTTVAR_SHIFT bits. Because 534 * the values coincide with the alpha and beta parameters suggested 535 * for RTO calculation (1/8 for srtt, 1/4 for rttvar), the combination 536 * of computing 1/8 of the new value and transforming it to the 537 * fixed-point representation required zero instructions. However, 538 * the storage representations no longer coincide with the alpha/beta 539 * shifts; instead, more fractional bits are present. 540 * 541 * The storage representation of srtt is 1/32 slow ticks, or 1/64 s. 542 * (The assumption that a slow tick is 500 ms should not be present in 543 * the code.) 544 * 545 * The storage representation of rttvar is 1/16 slow ticks, or 1/32 s. 546 * There may be some confusion about this in the code. 547 * 548 * For historical reasons, these scales are also used in smoothing the 549 * average (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 550 * This results in alpha of 0.125 and beta of 0.25, following RFC2988 551 * section 2.3 552 * 553 * XXX Change SHIFT values to LGWEIGHT and REP_SHIFT, and adjust 554 * the code to use the correct ones. 555 */ 556 #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ 557 #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */ 558 559 /* 560 * Compute TCP retransmission timer, following RFC2988. 561 * This macro returns a value in slow timeout ticks. 562 * 563 * Section 2.2 requires that the RTO value be 564 * srtt + max(G, 4*RTTVAR) 565 * where G is the clock granularity. 566 * 567 * This comment has not necessarily been updated for the new storage 568 * representation: 569 * 570 * Because of the way we do the smoothing, srtt and rttvar 571 * will each average +1/2 tick of bias. When we compute 572 * the retransmit timer, we want 1/2 tick of rounding and 573 * 1 extra tick because of +-1/2 tick uncertainty in the 574 * firing of the timer. The bias will give us exactly the 575 * 1.5 tick we need. But, because the bias is 576 * statistical, we have to test that we don't drop below 577 * the minimum feasible timer (which is 2 ticks). 578 * This macro assumes that the value of 1<<TCP_RTTVAR_SHIFT 579 * is the same as the multiplier for rttvar. 580 * 581 * This macro appears to be wrong; it should be checking rttvar*4 in 582 * ticks and making sure we use 1 instead if rttvar*4 rounds to 0. It 583 * appears to be treating srtt as being in the old storage 584 * representation, resulting in a factor of 4 extra. 585 */ 586 #define TCP_REXMTVAL(tp) \ 587 ((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) >> 2) 588 589 /* 590 * Compute the initial window for slow start. 591 */ 592 #define TCP_INITIAL_WINDOW(iw, segsz) \ 593 uimin((iw) * (segsz), uimax(2 * (segsz), tcp_init_win_max[(iw)])) 594 595 /* 596 * TCP statistics. 597 * Each counter is an unsigned 64-bit value. 598 * 599 * Many of these should be kept per connection, but that's inconvenient 600 * at the moment. 601 */ 602 #define TCP_STAT_CONNATTEMPT 0 /* connections initiated */ 603 #define TCP_STAT_ACCEPTS 1 /* connections accepted */ 604 #define TCP_STAT_CONNECTS 2 /* connections established */ 605 #define TCP_STAT_DROPS 3 /* connections dropped */ 606 #define TCP_STAT_CONNDROPS 4 /* embryonic connections dropped */ 607 #define TCP_STAT_CLOSED 5 /* conn. closed (includes drops) */ 608 #define TCP_STAT_SEGSTIMED 6 /* segs where we tried to get rtt */ 609 #define TCP_STAT_RTTUPDATED 7 /* times we succeeded */ 610 #define TCP_STAT_DELACK 8 /* delayed ACKs sent */ 611 #define TCP_STAT_TIMEOUTDROP 9 /* conn. dropped in rxmt timeout */ 612 #define TCP_STAT_REXMTTIMEO 10 /* retransmit timeouts */ 613 #define TCP_STAT_PERSISTTIMEO 11 /* persist timeouts */ 614 #define TCP_STAT_KEEPTIMEO 12 /* keepalive timeouts */ 615 #define TCP_STAT_KEEPPROBE 13 /* keepalive probes sent */ 616 #define TCP_STAT_KEEPDROPS 14 /* connections dropped in keepalive */ 617 #define TCP_STAT_PERSISTDROPS 15 /* connections dropped in persist */ 618 #define TCP_STAT_CONNSDRAINED 16 /* connections drained due to memory 619 shortage */ 620 #define TCP_STAT_PMTUBLACKHOLE 17 /* PMTUD blackhole detected */ 621 #define TCP_STAT_SNDTOTAL 18 /* total packets sent */ 622 #define TCP_STAT_SNDPACK 19 /* data packets sent */ 623 #define TCP_STAT_SNDBYTE 20 /* data bytes sent */ 624 #define TCP_STAT_SNDREXMITPACK 21 /* data packets retransmitted */ 625 #define TCP_STAT_SNDREXMITBYTE 22 /* data bytes retransmitted */ 626 #define TCP_STAT_SNDACKS 23 /* ACK-only packets sent */ 627 #define TCP_STAT_SNDPROBE 24 /* window probes sent */ 628 #define TCP_STAT_SNDURG 25 /* packets sent with URG only */ 629 #define TCP_STAT_SNDWINUP 26 /* window update-only packets sent */ 630 #define TCP_STAT_SNDCTRL 27 /* control (SYN|FIN|RST) packets sent */ 631 #define TCP_STAT_RCVTOTAL 28 /* total packets received */ 632 #define TCP_STAT_RCVPACK 29 /* packets received in sequence */ 633 #define TCP_STAT_RCVBYTE 30 /* bytes received in sequence */ 634 #define TCP_STAT_RCVBADSUM 31 /* packets received with cksum errs */ 635 #define TCP_STAT_RCVBADOFF 32 /* packets received with bad offset */ 636 #define TCP_STAT_RCVMEMDROP 33 /* packets dropped for lack of memory */ 637 #define TCP_STAT_RCVSHORT 34 /* packets received too short */ 638 #define TCP_STAT_RCVDUPPACK 35 /* duplicate-only packets received */ 639 #define TCP_STAT_RCVDUPBYTE 36 /* duplicate-only bytes received */ 640 #define TCP_STAT_RCVPARTDUPPACK 37 /* packets with some duplicate data */ 641 #define TCP_STAT_RCVPARTDUPBYTE 38 /* dup. bytes in part-dup. packets */ 642 #define TCP_STAT_RCVOOPACK 39 /* out-of-order packets received */ 643 #define TCP_STAT_RCVOOBYTE 40 /* out-of-order bytes received */ 644 #define TCP_STAT_RCVPACKAFTERWIN 41 /* packets with data after window */ 645 #define TCP_STAT_RCVBYTEAFTERWIN 42 /* bytes received after window */ 646 #define TCP_STAT_RCVAFTERCLOSE 43 /* packets received after "close" */ 647 #define TCP_STAT_RCVWINPROBE 44 /* rcvd window probe packets */ 648 #define TCP_STAT_RCVDUPACK 45 /* rcvd duplicate ACKs */ 649 #define TCP_STAT_RCVACKTOOMUCH 46 /* rcvd ACKs for unsent data */ 650 #define TCP_STAT_RCVACKPACK 47 /* rcvd ACK packets */ 651 #define TCP_STAT_RCVACKBYTE 48 /* bytes ACKed by rcvd ACKs */ 652 #define TCP_STAT_RCVWINUPD 49 /* rcvd window update packets */ 653 #define TCP_STAT_PAWSDROP 50 /* segments dropped due to PAWS */ 654 #define TCP_STAT_PREDACK 51 /* times hdr predict OK for ACKs */ 655 #define TCP_STAT_PREDDAT 52 /* times hdr predict OK for data pkts */ 656 #define TCP_STAT_PCBHASHMISS 53 /* input packets missing PCB hash */ 657 #define TCP_STAT_NOPORT 54 /* no socket on port */ 658 #define TCP_STAT_BADSYN 55 /* received ACK for which we have 659 no SYN in compressed state */ 660 #define TCP_STAT_DELAYED_FREE 56 /* delayed pool_put() of tcpcb */ 661 #define TCP_STAT_SC_ADDED 57 /* # of sc entries added */ 662 #define TCP_STAT_SC_COMPLETED 58 /* # of sc connections completed */ 663 #define TCP_STAT_SC_TIMED_OUT 59 /* # of sc entries timed out */ 664 #define TCP_STAT_SC_OVERFLOWED 60 /* # of sc drops due to overflow */ 665 #define TCP_STAT_SC_RESET 61 /* # of sc drops due to RST */ 666 #define TCP_STAT_SC_UNREACH 62 /* # of sc drops due to ICMP unreach */ 667 #define TCP_STAT_SC_BUCKETOVERFLOW 63 /* # of sc drops due to bucket ovflow */ 668 #define TCP_STAT_SC_ABORTED 64 /* # of sc entries aborted (no mem) */ 669 #define TCP_STAT_SC_DUPESYN 65 /* # of duplicate SYNs received */ 670 #define TCP_STAT_SC_DROPPED 66 /* # of SYNs dropped (no route/mem) */ 671 #define TCP_STAT_SC_COLLISIONS 67 /* # of sc hash collisions */ 672 #define TCP_STAT_SC_RETRANSMITTED 68 /* # of sc retransmissions */ 673 #define TCP_STAT_SC_DELAYED_FREE 69 /* # of delayed pool_put()s */ 674 #define TCP_STAT_SELFQUENCH 70 /* # of ENOBUFS we get on output */ 675 #define TCP_STAT_BADSIG 71 /* # of drops due to bad signature */ 676 #define TCP_STAT_GOODSIG 72 /* # of packets with good signature */ 677 #define TCP_STAT_ECN_SHS 73 /* # of successful ECN handshakes */ 678 #define TCP_STAT_ECN_CE 74 /* # of packets with CE bit */ 679 #define TCP_STAT_ECN_ECT 75 /* # of packets with ECT(0) bit */ 680 681 #define TCP_NSTATS 76 682 683 /* 684 * Names for TCP sysctl objects. 685 */ 686 #define TCPCTL_RFC1323 1 /* RFC1323 timestamps/scaling */ 687 #define TCPCTL_SENDSPACE 2 /* default send buffer */ 688 #define TCPCTL_RECVSPACE 3 /* default recv buffer */ 689 #define TCPCTL_MSSDFLT 4 /* default seg size */ 690 #define TCPCTL_SYN_CACHE_LIMIT 5 /* max size of comp. state engine */ 691 #define TCPCTL_SYN_BUCKET_LIMIT 6 /* max size of hash bucket */ 692 #if 0 /*obsoleted*/ 693 #define TCPCTL_SYN_CACHE_INTER 7 /* interval of comp. state timer */ 694 #endif 695 #define TCPCTL_INIT_WIN 8 /* initial window */ 696 #define TCPCTL_MSS_IFMTU 9 /* mss from interface, not in_maxmtu */ 697 #define TCPCTL_SACK 10 /* RFC2018 selective acknowledgement */ 698 #define TCPCTL_WSCALE 11 /* RFC1323 window scaling */ 699 #define TCPCTL_TSTAMP 12 /* RFC1323 timestamps */ 700 #if 0 /*obsoleted*/ 701 #define TCPCTL_COMPAT_42 13 /* 4.2BSD TCP bug work-arounds */ 702 #endif 703 #define TCPCTL_CWM 14 /* Congestion Window Monitoring */ 704 #define TCPCTL_CWM_BURSTSIZE 15 /* burst size allowed by CWM */ 705 #define TCPCTL_ACK_ON_PUSH 16 /* ACK immediately on PUSH */ 706 #define TCPCTL_KEEPIDLE 17 /* keepalive idle time */ 707 #define TCPCTL_KEEPINTVL 18 /* keepalive probe interval */ 708 #define TCPCTL_KEEPCNT 19 /* keepalive count */ 709 #define TCPCTL_SLOWHZ 20 /* PR_SLOWHZ (read-only) */ 710 #define TCPCTL_NEWRENO 21 /* NewReno Congestion Control */ 711 #define TCPCTL_LOG_REFUSED 22 /* Log refused connections */ 712 #if 0 /*obsoleted*/ 713 #define TCPCTL_RSTRATELIMIT 23 /* RST rate limit */ 714 #endif 715 #define TCPCTL_RSTPPSLIMIT 24 /* RST pps limit */ 716 #define TCPCTL_DELACK_TICKS 25 /* # ticks to delay ACK */ 717 #define TCPCTL_INIT_WIN_LOCAL 26 /* initial window for local nets */ 718 #define TCPCTL_IDENT 27 /* rfc 931 identd */ 719 #define TCPCTL_ACKDROPRATELIMIT 28 /* SYN/RST -> ACK rate limit */ 720 #define TCPCTL_LOOPBACKCKSUM 29 /* do TCP checksum on loopback */ 721 #define TCPCTL_STATS 30 /* TCP statistics */ 722 #define TCPCTL_DEBUG 31 /* TCP debug sockets */ 723 #define TCPCTL_DEBX 32 /* # of tcp debug sockets */ 724 #define TCPCTL_DROP 33 /* drop tcp connection */ 725 #define TCPCTL_MSL 34 /* Max Segment Life */ 726 727 #ifdef _KERNEL 728 729 extern struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 730 extern const struct pr_usrreqs tcp_usrreqs; 731 732 extern u_int32_t tcp_now; /* for RFC 1323 timestamps */ 733 extern int tcp_do_rfc1323; /* enabled/disabled? */ 734 extern int tcp_do_sack; /* SACK enabled/disabled? */ 735 extern int tcp_do_win_scale; /* RFC1323 window scaling enabled/disabled? */ 736 extern int tcp_do_timestamps; /* RFC1323 timestamps enabled/disabled? */ 737 extern int tcp_mssdflt; /* default seg size */ 738 extern int tcp_minmss; /* minimal seg size */ 739 extern int tcp_msl; /* max segment life */ 740 extern int tcp_init_win; /* initial window */ 741 extern int tcp_init_win_local; /* initial window for local nets */ 742 extern int tcp_init_win_max[11];/* max sizes for values of tcp_init_win_* */ 743 extern int tcp_mss_ifmtu; /* take MSS from interface, not in_maxmtu */ 744 extern int tcp_cwm; /* enable Congestion Window Monitoring */ 745 extern int tcp_cwm_burstsize; /* burst size allowed by CWM */ 746 extern int tcp_ack_on_push; /* ACK immediately on PUSH */ 747 extern int tcp_log_refused; /* log refused connections */ 748 extern int tcp_do_ecn; /* TCP ECN enabled/disabled? */ 749 extern int tcp_ecn_maxretries; /* Max ECN setup retries */ 750 extern int tcp_do_rfc1948; /* ISS by cryptographic hash */ 751 extern int tcp_sack_tp_maxholes; /* Max holes per connection. */ 752 extern int tcp_sack_globalmaxholes; /* Max holes per system. */ 753 extern int tcp_sack_globalholes; /* Number of holes present. */ 754 extern int tcp_do_abc; /* RFC3465 ABC enabled/disabled? */ 755 extern int tcp_abc_aggressive; /* 1: L=2*SMSS 0: L=1*SMSS */ 756 757 extern int tcp_msl_enable; /* enable TIME_WAIT truncation */ 758 extern int tcp_msl_loop; /* MSL for loopback */ 759 extern int tcp_msl_local; /* MSL for 'local' */ 760 extern int tcp_msl_remote; /* MSL otherwise */ 761 extern int tcp_msl_remote_threshold; /* RTT threshold */ 762 extern int tcp_rttlocal; /* Use RTT to decide who's 'local' */ 763 extern int tcp4_vtw_enable; 764 extern int tcp6_vtw_enable; 765 extern int tcp_vtw_was_enabled; 766 extern int tcp_vtw_entries; 767 768 extern int tcp_rst_ppslim; 769 extern int tcp_ackdrop_ppslim; 770 771 #ifdef MBUFTRACE 772 extern struct mowner tcp_rx_mowner; 773 extern struct mowner tcp_tx_mowner; 774 extern struct mowner tcp_reass_mowner; 775 extern struct mowner tcp_sock_mowner; 776 extern struct mowner tcp_sock_rx_mowner; 777 extern struct mowner tcp_sock_tx_mowner; 778 extern struct mowner tcp_mowner; 779 #endif 780 781 extern int tcp_do_autorcvbuf; 782 extern int tcp_autorcvbuf_inc; 783 extern int tcp_autorcvbuf_max; 784 extern int tcp_do_autosndbuf; 785 extern int tcp_autosndbuf_inc; 786 extern int tcp_autosndbuf_max; 787 788 struct secasvar; 789 790 void tcp_canceltimers(struct tcpcb *); 791 struct tcpcb * 792 tcp_close(struct tcpcb *); 793 int tcp_isdead(struct tcpcb *); 794 #ifdef INET6 795 void *tcp6_ctlinput(int, const struct sockaddr *, void *); 796 #endif 797 void *tcp_ctlinput(int, const struct sockaddr *, void *); 798 int tcp_ctloutput(int, struct socket *, struct sockopt *); 799 struct tcpcb * 800 tcp_disconnect1(struct tcpcb *); 801 struct tcpcb * 802 tcp_drop(struct tcpcb *, int); 803 #ifdef TCP_SIGNATURE 804 int tcp_signature_apply(void *, void *, u_int); 805 struct secasvar *tcp_signature_getsav(struct mbuf *); 806 int tcp_signature(struct mbuf *, struct tcphdr *, int, struct secasvar *, 807 char *); 808 #endif 809 void tcp_drain(void); 810 void tcp_drainstub(void); 811 void tcp_established(struct tcpcb *); 812 void tcp_init(void); 813 void tcp_init_common(unsigned); 814 #ifdef INET6 815 int tcp6_input(struct mbuf **, int *, int); 816 #endif 817 void tcp_input(struct mbuf *, int, int); 818 u_int tcp_hdrsz(struct tcpcb *); 819 u_long tcp_mss_to_advertise(const struct ifnet *, int); 820 void tcp_mss_from_peer(struct tcpcb *, int); 821 void tcp_tcpcb_template(void); 822 struct tcpcb * 823 tcp_newtcpcb(int, struct inpcb *); 824 void tcp_notify(struct inpcb *, int); 825 u_int tcp_optlen(struct tcpcb *); 826 int tcp_output(struct tcpcb *); 827 void tcp_pulloutofband(struct socket *, 828 struct tcphdr *, struct mbuf *, int); 829 void tcp_quench(struct inpcb *); 830 void tcp_mtudisc(struct inpcb *, int); 831 #ifdef INET6 832 void tcp6_mtudisc_callback(struct in6_addr *); 833 #endif 834 835 void tcpipqent_init(void); 836 struct ipqent *tcpipqent_alloc(void); 837 void tcpipqent_free(struct ipqent *); 838 839 int tcp_respond(struct tcpcb *, struct mbuf *, struct mbuf *, 840 struct tcphdr *, tcp_seq, tcp_seq, int); 841 void tcp_rmx_rtt(struct tcpcb *); 842 void tcp_setpersist(struct tcpcb *); 843 #ifdef TCP_SIGNATURE 844 int tcp_signature_compute(struct mbuf *, struct tcphdr *, int, int, 845 int, u_char *, u_int); 846 #endif 847 void tcp_fasttimo(void); 848 struct mbuf * 849 tcp_template(struct tcpcb *); 850 void tcp_trace(short, short, struct tcpcb *, struct mbuf *, int); 851 struct tcpcb * 852 tcp_usrclosed(struct tcpcb *); 853 void tcp_usrreq_init(void); 854 void tcp_xmit_timer(struct tcpcb *, uint32_t); 855 tcp_seq tcp_new_iss(struct tcpcb *); 856 tcp_seq tcp_new_iss1(void *, void *, u_int16_t, u_int16_t, size_t); 857 858 void tcp_sack_init(void); 859 void tcp_new_dsack(struct tcpcb *, tcp_seq, u_int32_t); 860 void tcp_sack_option(struct tcpcb *, const struct tcphdr *, 861 const u_char *, int); 862 void tcp_del_sackholes(struct tcpcb *, const struct tcphdr *); 863 void tcp_free_sackholes(struct tcpcb *); 864 void tcp_sack_adjust(struct tcpcb *tp); 865 struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt); 866 int tcp_sack_numblks(const struct tcpcb *); 867 #define TCP_SACK_OPTLEN(nblks) ((nblks) * 8 + 2 + 2) 868 869 void tcp_statinc(u_int); 870 void tcp_statadd(u_int, uint64_t); 871 872 int tcp_input_checksum(int, struct mbuf *, const struct tcphdr *, int, int, 873 int); 874 875 int tcp_dooptions(struct tcpcb *, const u_char *, int, 876 struct tcphdr *, struct mbuf *, int, struct tcp_opt_info *); 877 #endif 878 879 #endif /* !_NETINET_TCP_VAR_H_ */ 880
Indexes created Sun Sep 21 20:09:37 GMT 2025