tcp_subr.c revision 1.228
1 /* $NetBSD: tcp_subr.c,v 1.228 2008/04/24 11:38:38 ad 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 (c) 1997, 1998, 2000, 2001, 2008 The NetBSD Foundation, Inc. 34 * All rights reserved. 35 * 36 * This code is derived from software contributed to The NetBSD Foundation 37 * by Jason R. Thorpe and Kevin M. Lahey of the Numerical Aerospace Simulation 38 * Facility, NASA Ames Research Center. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. All advertising materials mentioning features or use of this software 49 * must display the following acknowledgement: 50 * This product includes software developed by the NetBSD 51 * Foundation, Inc. and its contributors. 52 * 4. Neither the name of The NetBSD Foundation nor the names of its 53 * contributors may be used to endorse or promote products derived 54 * from this software without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 57 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 58 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 59 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 60 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 61 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 62 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 63 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 64 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 65 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 66 * POSSIBILITY OF SUCH DAMAGE. 67 */ 68 69 /* 70 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 71 * The Regents of the University of California. All rights reserved. 72 * 73 * Redistribution and use in source and binary forms, with or without 74 * modification, are permitted provided that the following conditions 75 * are met: 76 * 1. Redistributions of source code must retain the above copyright 77 * notice, this list of conditions and the following disclaimer. 78 * 2. Redistributions in binary form must reproduce the above copyright 79 * notice, this list of conditions and the following disclaimer in the 80 * documentation and/or other materials provided with the distribution. 81 * 3. Neither the name of the University nor the names of its contributors 82 * may be used to endorse or promote products derived from this software 83 * without specific prior written permission. 84 * 85 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 86 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 87 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 88 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 89 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 90 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 91 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 92 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 93 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 94 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 95 * SUCH DAMAGE. 96 * 97 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 98 */ 99 100 #include <sys/cdefs.h> 101 __KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.228 2008/04/24 11:38:38 ad Exp $"); 102 103 #include "opt_inet.h" 104 #include "opt_ipsec.h" 105 #include "opt_tcp_compat_42.h" 106 #include "opt_inet_csum.h" 107 #include "opt_mbuftrace.h" 108 #include "rnd.h" 109 110 #include <sys/param.h> 111 #include <sys/proc.h> 112 #include <sys/systm.h> 113 #include <sys/malloc.h> 114 #include <sys/mbuf.h> 115 #include <sys/socket.h> 116 #include <sys/socketvar.h> 117 #include <sys/protosw.h> 118 #include <sys/errno.h> 119 #include <sys/kernel.h> 120 #include <sys/pool.h> 121 #if NRND > 0 122 #include <sys/md5.h> 123 #include <sys/rnd.h> 124 #endif 125 126 #include <net/route.h> 127 #include <net/if.h> 128 129 #include <netinet/in.h> 130 #include <netinet/in_systm.h> 131 #include <netinet/ip.h> 132 #include <netinet/in_pcb.h> 133 #include <netinet/ip_var.h> 134 #include <netinet/ip_icmp.h> 135 136 #ifdef INET6 137 #ifndef INET 138 #include <netinet/in.h> 139 #endif 140 #include <netinet/ip6.h> 141 #include <netinet6/in6_pcb.h> 142 #include <netinet6/ip6_var.h> 143 #include <netinet6/in6_var.h> 144 #include <netinet6/ip6protosw.h> 145 #include <netinet/icmp6.h> 146 #include <netinet6/nd6.h> 147 #endif 148 149 #include <netinet/tcp.h> 150 #include <netinet/tcp_fsm.h> 151 #include <netinet/tcp_seq.h> 152 #include <netinet/tcp_timer.h> 153 #include <netinet/tcp_var.h> 154 #include <netinet/tcp_private.h> 155 #include <netinet/tcp_congctl.h> 156 #include <netinet/tcpip.h> 157 158 #ifdef IPSEC 159 #include <netinet6/ipsec.h> 160 #include <netkey/key.h> 161 #endif /*IPSEC*/ 162 163 #ifdef FAST_IPSEC 164 #include <netipsec/ipsec.h> 165 #include <netipsec/xform.h> 166 #ifdef INET6 167 #include <netipsec/ipsec6.h> 168 #endif 169 #include <netipsec/key.h> 170 #endif /* FAST_IPSEC*/ 171 172 173 struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 174 u_int32_t tcp_now; /* for RFC 1323 timestamps */ 175 176 percpu_t *tcpstat_percpu; 177 178 /* patchable/settable parameters for tcp */ 179 int tcp_mssdflt = TCP_MSS; 180 int tcp_minmss = TCP_MINMSS; 181 int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 182 int tcp_do_rfc1323 = 1; /* window scaling / timestamps (obsolete) */ 183 #if NRND > 0 184 int tcp_do_rfc1948 = 0; /* ISS by cryptographic hash */ 185 #endif 186 int tcp_do_sack = 1; /* selective acknowledgement */ 187 int tcp_do_win_scale = 1; /* RFC1323 window scaling */ 188 int tcp_do_timestamps = 1; /* RFC1323 timestamps */ 189 int tcp_ack_on_push = 0; /* set to enable immediate ACK-on-PUSH */ 190 int tcp_do_ecn = 0; /* Explicit Congestion Notification */ 191 #ifndef TCP_INIT_WIN 192 #define TCP_INIT_WIN 0 /* initial slow start window */ 193 #endif 194 #ifndef TCP_INIT_WIN_LOCAL 195 #define TCP_INIT_WIN_LOCAL 4 /* initial slow start window for local nets */ 196 #endif 197 int tcp_init_win = TCP_INIT_WIN; 198 int tcp_init_win_local = TCP_INIT_WIN_LOCAL; 199 int tcp_mss_ifmtu = 0; 200 #ifdef TCP_COMPAT_42 201 int tcp_compat_42 = 1; 202 #else 203 int tcp_compat_42 = 0; 204 #endif 205 int tcp_rst_ppslim = 100; /* 100pps */ 206 int tcp_ackdrop_ppslim = 100; /* 100pps */ 207 int tcp_do_loopback_cksum = 0; 208 int tcp_do_abc = 1; /* RFC3465 Appropriate byte counting. */ 209 int tcp_abc_aggressive = 1; /* 1: L=2*SMSS 0: L=1*SMSS */ 210 int tcp_sack_tp_maxholes = 32; 211 int tcp_sack_globalmaxholes = 1024; 212 int tcp_sack_globalholes = 0; 213 int tcp_ecn_maxretries = 1; 214 215 /* tcb hash */ 216 #ifndef TCBHASHSIZE 217 #define TCBHASHSIZE 128 218 #endif 219 int tcbhashsize = TCBHASHSIZE; 220 221 /* syn hash parameters */ 222 #define TCP_SYN_HASH_SIZE 293 223 #define TCP_SYN_BUCKET_SIZE 35 224 int tcp_syn_cache_size = TCP_SYN_HASH_SIZE; 225 int tcp_syn_cache_limit = TCP_SYN_HASH_SIZE*TCP_SYN_BUCKET_SIZE; 226 int tcp_syn_bucket_limit = 3*TCP_SYN_BUCKET_SIZE; 227 struct syn_cache_head tcp_syn_cache[TCP_SYN_HASH_SIZE]; 228 229 int tcp_freeq(struct tcpcb *); 230 231 #ifdef INET 232 void tcp_mtudisc_callback(struct in_addr); 233 #endif 234 #ifdef INET6 235 void tcp6_mtudisc_callback(struct in6_addr *); 236 #endif 237 238 #ifdef INET6 239 void tcp6_mtudisc(struct in6pcb *, int); 240 #endif 241 242 POOL_INIT(tcpcb_pool, sizeof(struct tcpcb), 0, 0, 0, "tcpcbpl", NULL, 243 IPL_SOFTNET); 244 245 #ifdef TCP_CSUM_COUNTERS 246 #include <sys/device.h> 247 248 #if defined(INET) 249 struct evcnt tcp_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 250 NULL, "tcp", "hwcsum bad"); 251 struct evcnt tcp_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 252 NULL, "tcp", "hwcsum ok"); 253 struct evcnt tcp_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 254 NULL, "tcp", "hwcsum data"); 255 struct evcnt tcp_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 256 NULL, "tcp", "swcsum"); 257 258 EVCNT_ATTACH_STATIC(tcp_hwcsum_bad); 259 EVCNT_ATTACH_STATIC(tcp_hwcsum_ok); 260 EVCNT_ATTACH_STATIC(tcp_hwcsum_data); 261 EVCNT_ATTACH_STATIC(tcp_swcsum); 262 #endif /* defined(INET) */ 263 264 #if defined(INET6) 265 struct evcnt tcp6_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 266 NULL, "tcp6", "hwcsum bad"); 267 struct evcnt tcp6_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 268 NULL, "tcp6", "hwcsum ok"); 269 struct evcnt tcp6_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 270 NULL, "tcp6", "hwcsum data"); 271 struct evcnt tcp6_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 272 NULL, "tcp6", "swcsum"); 273 274 EVCNT_ATTACH_STATIC(tcp6_hwcsum_bad); 275 EVCNT_ATTACH_STATIC(tcp6_hwcsum_ok); 276 EVCNT_ATTACH_STATIC(tcp6_hwcsum_data); 277 EVCNT_ATTACH_STATIC(tcp6_swcsum); 278 #endif /* defined(INET6) */ 279 #endif /* TCP_CSUM_COUNTERS */ 280 281 282 #ifdef TCP_OUTPUT_COUNTERS 283 #include <sys/device.h> 284 285 struct evcnt tcp_output_bigheader = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 286 NULL, "tcp", "output big header"); 287 struct evcnt tcp_output_predict_hit = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 288 NULL, "tcp", "output predict hit"); 289 struct evcnt tcp_output_predict_miss = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 290 NULL, "tcp", "output predict miss"); 291 struct evcnt tcp_output_copysmall = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 292 NULL, "tcp", "output copy small"); 293 struct evcnt tcp_output_copybig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 294 NULL, "tcp", "output copy big"); 295 struct evcnt tcp_output_refbig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 296 NULL, "tcp", "output reference big"); 297 298 EVCNT_ATTACH_STATIC(tcp_output_bigheader); 299 EVCNT_ATTACH_STATIC(tcp_output_predict_hit); 300 EVCNT_ATTACH_STATIC(tcp_output_predict_miss); 301 EVCNT_ATTACH_STATIC(tcp_output_copysmall); 302 EVCNT_ATTACH_STATIC(tcp_output_copybig); 303 EVCNT_ATTACH_STATIC(tcp_output_refbig); 304 305 #endif /* TCP_OUTPUT_COUNTERS */ 306 307 #ifdef TCP_REASS_COUNTERS 308 #include <sys/device.h> 309 310 struct evcnt tcp_reass_ = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 311 NULL, "tcp_reass", "calls"); 312 struct evcnt tcp_reass_empty = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 313 &tcp_reass_, "tcp_reass", "insert into empty queue"); 314 struct evcnt tcp_reass_iteration[8] = { 315 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", ">7 iterations"), 316 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "1 iteration"), 317 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "2 iterations"), 318 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "3 iterations"), 319 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "4 iterations"), 320 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "5 iterations"), 321 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "6 iterations"), 322 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "7 iterations"), 323 }; 324 struct evcnt tcp_reass_prependfirst = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 325 &tcp_reass_, "tcp_reass", "prepend to first"); 326 struct evcnt tcp_reass_prepend = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 327 &tcp_reass_, "tcp_reass", "prepend"); 328 struct evcnt tcp_reass_insert = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 329 &tcp_reass_, "tcp_reass", "insert"); 330 struct evcnt tcp_reass_inserttail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 331 &tcp_reass_, "tcp_reass", "insert at tail"); 332 struct evcnt tcp_reass_append = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 333 &tcp_reass_, "tcp_reass", "append"); 334 struct evcnt tcp_reass_appendtail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 335 &tcp_reass_, "tcp_reass", "append to tail fragment"); 336 struct evcnt tcp_reass_overlaptail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 337 &tcp_reass_, "tcp_reass", "overlap at end"); 338 struct evcnt tcp_reass_overlapfront = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 339 &tcp_reass_, "tcp_reass", "overlap at start"); 340 struct evcnt tcp_reass_segdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 341 &tcp_reass_, "tcp_reass", "duplicate segment"); 342 struct evcnt tcp_reass_fragdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 343 &tcp_reass_, "tcp_reass", "duplicate fragment"); 344 345 EVCNT_ATTACH_STATIC(tcp_reass_); 346 EVCNT_ATTACH_STATIC(tcp_reass_empty); 347 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 0); 348 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 1); 349 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 2); 350 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 3); 351 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 4); 352 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 5); 353 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 6); 354 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 7); 355 EVCNT_ATTACH_STATIC(tcp_reass_prependfirst); 356 EVCNT_ATTACH_STATIC(tcp_reass_prepend); 357 EVCNT_ATTACH_STATIC(tcp_reass_insert); 358 EVCNT_ATTACH_STATIC(tcp_reass_inserttail); 359 EVCNT_ATTACH_STATIC(tcp_reass_append); 360 EVCNT_ATTACH_STATIC(tcp_reass_appendtail); 361 EVCNT_ATTACH_STATIC(tcp_reass_overlaptail); 362 EVCNT_ATTACH_STATIC(tcp_reass_overlapfront); 363 EVCNT_ATTACH_STATIC(tcp_reass_segdup); 364 EVCNT_ATTACH_STATIC(tcp_reass_fragdup); 365 366 #endif /* TCP_REASS_COUNTERS */ 367 368 #ifdef MBUFTRACE 369 struct mowner tcp_mowner = MOWNER_INIT("tcp", ""); 370 struct mowner tcp_rx_mowner = MOWNER_INIT("tcp", "rx"); 371 struct mowner tcp_tx_mowner = MOWNER_INIT("tcp", "tx"); 372 struct mowner tcp_sock_mowner = MOWNER_INIT("tcp", "sock"); 373 struct mowner tcp_sock_rx_mowner = MOWNER_INIT("tcp", "sock rx"); 374 struct mowner tcp_sock_tx_mowner = MOWNER_INIT("tcp", "sock tx"); 375 #endif 376 377 /* 378 * Tcp initialization 379 */ 380 void 381 tcp_init(void) 382 { 383 int hlen; 384 385 in_pcbinit(&tcbtable, tcbhashsize, tcbhashsize); 386 387 hlen = sizeof(struct ip) + sizeof(struct tcphdr); 388 #ifdef INET6 389 if (sizeof(struct ip) < sizeof(struct ip6_hdr)) 390 hlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 391 #endif 392 if (max_protohdr < hlen) 393 max_protohdr = hlen; 394 if (max_linkhdr + hlen > MHLEN) 395 panic("tcp_init"); 396 397 #ifdef INET 398 icmp_mtudisc_callback_register(tcp_mtudisc_callback); 399 #endif 400 #ifdef INET6 401 icmp6_mtudisc_callback_register(tcp6_mtudisc_callback); 402 #endif 403 404 /* Initialize timer state. */ 405 tcp_timer_init(); 406 407 /* Initialize the compressed state engine. */ 408 syn_cache_init(); 409 410 /* Initialize the congestion control algorithms. */ 411 tcp_congctl_init(); 412 413 /* Initialize the TCPCB template. */ 414 tcp_tcpcb_template(); 415 416 MOWNER_ATTACH(&tcp_tx_mowner); 417 MOWNER_ATTACH(&tcp_rx_mowner); 418 MOWNER_ATTACH(&tcp_reass_mowner); 419 MOWNER_ATTACH(&tcp_sock_mowner); 420 MOWNER_ATTACH(&tcp_sock_tx_mowner); 421 MOWNER_ATTACH(&tcp_sock_rx_mowner); 422 MOWNER_ATTACH(&tcp_mowner); 423 } 424 425 /* 426 * Create template to be used to send tcp packets on a connection. 427 * Call after host entry created, allocates an mbuf and fills 428 * in a skeletal tcp/ip header, minimizing the amount of work 429 * necessary when the connection is used. 430 */ 431 struct mbuf * 432 tcp_template(struct tcpcb *tp) 433 { 434 struct inpcb *inp = tp->t_inpcb; 435 #ifdef INET6 436 struct in6pcb *in6p = tp->t_in6pcb; 437 #endif 438 struct tcphdr *n; 439 struct mbuf *m; 440 int hlen; 441 442 switch (tp->t_family) { 443 case AF_INET: 444 hlen = sizeof(struct ip); 445 if (inp) 446 break; 447 #ifdef INET6 448 if (in6p) { 449 /* mapped addr case */ 450 if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr) 451 && IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) 452 break; 453 } 454 #endif 455 return NULL; /*EINVAL*/ 456 #ifdef INET6 457 case AF_INET6: 458 hlen = sizeof(struct ip6_hdr); 459 if (in6p) { 460 /* more sainty check? */ 461 break; 462 } 463 return NULL; /*EINVAL*/ 464 #endif 465 default: 466 hlen = 0; /*pacify gcc*/ 467 return NULL; /*EAFNOSUPPORT*/ 468 } 469 #ifdef DIAGNOSTIC 470 if (hlen + sizeof(struct tcphdr) > MCLBYTES) 471 panic("mclbytes too small for t_template"); 472 #endif 473 m = tp->t_template; 474 if (m && m->m_len == hlen + sizeof(struct tcphdr)) 475 ; 476 else { 477 if (m) 478 m_freem(m); 479 m = tp->t_template = NULL; 480 MGETHDR(m, M_DONTWAIT, MT_HEADER); 481 if (m && hlen + sizeof(struct tcphdr) > MHLEN) { 482 MCLGET(m, M_DONTWAIT); 483 if ((m->m_flags & M_EXT) == 0) { 484 m_free(m); 485 m = NULL; 486 } 487 } 488 if (m == NULL) 489 return NULL; 490 MCLAIM(m, &tcp_mowner); 491 m->m_pkthdr.len = m->m_len = hlen + sizeof(struct tcphdr); 492 } 493 494 bzero(mtod(m, void *), m->m_len); 495 496 n = (struct tcphdr *)(mtod(m, char *) + hlen); 497 498 switch (tp->t_family) { 499 case AF_INET: 500 { 501 struct ipovly *ipov; 502 mtod(m, struct ip *)->ip_v = 4; 503 mtod(m, struct ip *)->ip_hl = hlen >> 2; 504 ipov = mtod(m, struct ipovly *); 505 ipov->ih_pr = IPPROTO_TCP; 506 ipov->ih_len = htons(sizeof(struct tcphdr)); 507 if (inp) { 508 ipov->ih_src = inp->inp_laddr; 509 ipov->ih_dst = inp->inp_faddr; 510 } 511 #ifdef INET6 512 else if (in6p) { 513 /* mapped addr case */ 514 bcopy(&in6p->in6p_laddr.s6_addr32[3], &ipov->ih_src, 515 sizeof(ipov->ih_src)); 516 bcopy(&in6p->in6p_faddr.s6_addr32[3], &ipov->ih_dst, 517 sizeof(ipov->ih_dst)); 518 } 519 #endif 520 /* 521 * Compute the pseudo-header portion of the checksum 522 * now. We incrementally add in the TCP option and 523 * payload lengths later, and then compute the TCP 524 * checksum right before the packet is sent off onto 525 * the wire. 526 */ 527 n->th_sum = in_cksum_phdr(ipov->ih_src.s_addr, 528 ipov->ih_dst.s_addr, 529 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 530 break; 531 } 532 #ifdef INET6 533 case AF_INET6: 534 { 535 struct ip6_hdr *ip6; 536 mtod(m, struct ip *)->ip_v = 6; 537 ip6 = mtod(m, struct ip6_hdr *); 538 ip6->ip6_nxt = IPPROTO_TCP; 539 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 540 ip6->ip6_src = in6p->in6p_laddr; 541 ip6->ip6_dst = in6p->in6p_faddr; 542 ip6->ip6_flow = in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK; 543 if (ip6_auto_flowlabel) { 544 ip6->ip6_flow &= ~IPV6_FLOWLABEL_MASK; 545 ip6->ip6_flow |= 546 (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK); 547 } 548 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 549 ip6->ip6_vfc |= IPV6_VERSION; 550 551 /* 552 * Compute the pseudo-header portion of the checksum 553 * now. We incrementally add in the TCP option and 554 * payload lengths later, and then compute the TCP 555 * checksum right before the packet is sent off onto 556 * the wire. 557 */ 558 n->th_sum = in6_cksum_phdr(&in6p->in6p_laddr, 559 &in6p->in6p_faddr, htonl(sizeof(struct tcphdr)), 560 htonl(IPPROTO_TCP)); 561 break; 562 } 563 #endif 564 } 565 if (inp) { 566 n->th_sport = inp->inp_lport; 567 n->th_dport = inp->inp_fport; 568 } 569 #ifdef INET6 570 else if (in6p) { 571 n->th_sport = in6p->in6p_lport; 572 n->th_dport = in6p->in6p_fport; 573 } 574 #endif 575 n->th_seq = 0; 576 n->th_ack = 0; 577 n->th_x2 = 0; 578 n->th_off = 5; 579 n->th_flags = 0; 580 n->th_win = 0; 581 n->th_urp = 0; 582 return (m); 583 } 584 585 /* 586 * Send a single message to the TCP at address specified by 587 * the given TCP/IP header. If m == 0, then we make a copy 588 * of the tcpiphdr at ti and send directly to the addressed host. 589 * This is used to force keep alive messages out using the TCP 590 * template for a connection tp->t_template. If flags are given 591 * then we send a message back to the TCP which originated the 592 * segment ti, and discard the mbuf containing it and any other 593 * attached mbufs. 594 * 595 * In any case the ack and sequence number of the transmitted 596 * segment are as specified by the parameters. 597 */ 598 int 599 tcp_respond(struct tcpcb *tp, struct mbuf *template, struct mbuf *m, 600 struct tcphdr *th0, tcp_seq ack, tcp_seq seq, int flags) 601 { 602 #ifdef INET6 603 struct rtentry *rt; 604 #endif 605 struct route *ro; 606 int error, tlen, win = 0; 607 int hlen; 608 struct ip *ip; 609 #ifdef INET6 610 struct ip6_hdr *ip6; 611 #endif 612 int family; /* family on packet, not inpcb/in6pcb! */ 613 struct tcphdr *th; 614 struct socket *so; 615 616 if (tp != NULL && (flags & TH_RST) == 0) { 617 #ifdef DIAGNOSTIC 618 if (tp->t_inpcb && tp->t_in6pcb) 619 panic("tcp_respond: both t_inpcb and t_in6pcb are set"); 620 #endif 621 #ifdef INET 622 if (tp->t_inpcb) 623 win = sbspace(&tp->t_inpcb->inp_socket->so_rcv); 624 #endif 625 #ifdef INET6 626 if (tp->t_in6pcb) 627 win = sbspace(&tp->t_in6pcb->in6p_socket->so_rcv); 628 #endif 629 } 630 631 th = NULL; /* Quell uninitialized warning */ 632 ip = NULL; 633 #ifdef INET6 634 ip6 = NULL; 635 #endif 636 if (m == 0) { 637 if (!template) 638 return EINVAL; 639 640 /* get family information from template */ 641 switch (mtod(template, struct ip *)->ip_v) { 642 case 4: 643 family = AF_INET; 644 hlen = sizeof(struct ip); 645 break; 646 #ifdef INET6 647 case 6: 648 family = AF_INET6; 649 hlen = sizeof(struct ip6_hdr); 650 break; 651 #endif 652 default: 653 return EAFNOSUPPORT; 654 } 655 656 MGETHDR(m, M_DONTWAIT, MT_HEADER); 657 if (m) { 658 MCLAIM(m, &tcp_tx_mowner); 659 MCLGET(m, M_DONTWAIT); 660 if ((m->m_flags & M_EXT) == 0) { 661 m_free(m); 662 m = NULL; 663 } 664 } 665 if (m == NULL) 666 return (ENOBUFS); 667 668 if (tcp_compat_42) 669 tlen = 1; 670 else 671 tlen = 0; 672 673 m->m_data += max_linkhdr; 674 bcopy(mtod(template, void *), mtod(m, void *), 675 template->m_len); 676 switch (family) { 677 case AF_INET: 678 ip = mtod(m, struct ip *); 679 th = (struct tcphdr *)(ip + 1); 680 break; 681 #ifdef INET6 682 case AF_INET6: 683 ip6 = mtod(m, struct ip6_hdr *); 684 th = (struct tcphdr *)(ip6 + 1); 685 break; 686 #endif 687 #if 0 688 default: 689 /* noone will visit here */ 690 m_freem(m); 691 return EAFNOSUPPORT; 692 #endif 693 } 694 flags = TH_ACK; 695 } else { 696 697 if ((m->m_flags & M_PKTHDR) == 0) { 698 #if 0 699 printf("non PKTHDR to tcp_respond\n"); 700 #endif 701 m_freem(m); 702 return EINVAL; 703 } 704 #ifdef DIAGNOSTIC 705 if (!th0) 706 panic("th0 == NULL in tcp_respond"); 707 #endif 708 709 /* get family information from m */ 710 switch (mtod(m, struct ip *)->ip_v) { 711 case 4: 712 family = AF_INET; 713 hlen = sizeof(struct ip); 714 ip = mtod(m, struct ip *); 715 break; 716 #ifdef INET6 717 case 6: 718 family = AF_INET6; 719 hlen = sizeof(struct ip6_hdr); 720 ip6 = mtod(m, struct ip6_hdr *); 721 break; 722 #endif 723 default: 724 m_freem(m); 725 return EAFNOSUPPORT; 726 } 727 /* clear h/w csum flags inherited from rx packet */ 728 m->m_pkthdr.csum_flags = 0; 729 730 if ((flags & TH_SYN) == 0 || sizeof(*th0) > (th0->th_off << 2)) 731 tlen = sizeof(*th0); 732 else 733 tlen = th0->th_off << 2; 734 735 if (m->m_len > hlen + tlen && (m->m_flags & M_EXT) == 0 && 736 mtod(m, char *) + hlen == (char *)th0) { 737 m->m_len = hlen + tlen; 738 m_freem(m->m_next); 739 m->m_next = NULL; 740 } else { 741 struct mbuf *n; 742 743 #ifdef DIAGNOSTIC 744 if (max_linkhdr + hlen + tlen > MCLBYTES) { 745 m_freem(m); 746 return EMSGSIZE; 747 } 748 #endif 749 MGETHDR(n, M_DONTWAIT, MT_HEADER); 750 if (n && max_linkhdr + hlen + tlen > MHLEN) { 751 MCLGET(n, M_DONTWAIT); 752 if ((n->m_flags & M_EXT) == 0) { 753 m_freem(n); 754 n = NULL; 755 } 756 } 757 if (!n) { 758 m_freem(m); 759 return ENOBUFS; 760 } 761 762 MCLAIM(n, &tcp_tx_mowner); 763 n->m_data += max_linkhdr; 764 n->m_len = hlen + tlen; 765 m_copyback(n, 0, hlen, mtod(m, void *)); 766 m_copyback(n, hlen, tlen, (void *)th0); 767 768 m_freem(m); 769 m = n; 770 n = NULL; 771 } 772 773 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 774 switch (family) { 775 case AF_INET: 776 ip = mtod(m, struct ip *); 777 th = (struct tcphdr *)(ip + 1); 778 ip->ip_p = IPPROTO_TCP; 779 xchg(ip->ip_dst, ip->ip_src, struct in_addr); 780 ip->ip_p = IPPROTO_TCP; 781 break; 782 #ifdef INET6 783 case AF_INET6: 784 ip6 = mtod(m, struct ip6_hdr *); 785 th = (struct tcphdr *)(ip6 + 1); 786 ip6->ip6_nxt = IPPROTO_TCP; 787 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 788 ip6->ip6_nxt = IPPROTO_TCP; 789 break; 790 #endif 791 #if 0 792 default: 793 /* noone will visit here */ 794 m_freem(m); 795 return EAFNOSUPPORT; 796 #endif 797 } 798 xchg(th->th_dport, th->th_sport, u_int16_t); 799 #undef xchg 800 tlen = 0; /*be friendly with the following code*/ 801 } 802 th->th_seq = htonl(seq); 803 th->th_ack = htonl(ack); 804 th->th_x2 = 0; 805 if ((flags & TH_SYN) == 0) { 806 if (tp) 807 win >>= tp->rcv_scale; 808 if (win > TCP_MAXWIN) 809 win = TCP_MAXWIN; 810 th->th_win = htons((u_int16_t)win); 811 th->th_off = sizeof (struct tcphdr) >> 2; 812 tlen += sizeof(*th); 813 } else 814 tlen += th->th_off << 2; 815 m->m_len = hlen + tlen; 816 m->m_pkthdr.len = hlen + tlen; 817 m->m_pkthdr.rcvif = (struct ifnet *) 0; 818 th->th_flags = flags; 819 th->th_urp = 0; 820 821 switch (family) { 822 #ifdef INET 823 case AF_INET: 824 { 825 struct ipovly *ipov = (struct ipovly *)ip; 826 bzero(ipov->ih_x1, sizeof ipov->ih_x1); 827 ipov->ih_len = htons((u_int16_t)tlen); 828 829 th->th_sum = 0; 830 th->th_sum = in_cksum(m, hlen + tlen); 831 ip->ip_len = htons(hlen + tlen); 832 ip->ip_ttl = ip_defttl; 833 break; 834 } 835 #endif 836 #ifdef INET6 837 case AF_INET6: 838 { 839 th->th_sum = 0; 840 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr), 841 tlen); 842 ip6->ip6_plen = htons(tlen); 843 if (tp && tp->t_in6pcb) { 844 struct ifnet *oifp; 845 ro = &tp->t_in6pcb->in6p_route; 846 oifp = (rt = rtcache_validate(ro)) != NULL ? rt->rt_ifp 847 : NULL; 848 ip6->ip6_hlim = in6_selecthlim(tp->t_in6pcb, oifp); 849 } else 850 ip6->ip6_hlim = ip6_defhlim; 851 ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK; 852 if (ip6_auto_flowlabel) { 853 ip6->ip6_flow |= 854 (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK); 855 } 856 break; 857 } 858 #endif 859 } 860 861 if (tp && tp->t_inpcb) 862 so = tp->t_inpcb->inp_socket; 863 #ifdef INET6 864 else if (tp && tp->t_in6pcb) 865 so = tp->t_in6pcb->in6p_socket; 866 #endif 867 else 868 so = NULL; 869 870 if (tp != NULL && tp->t_inpcb != NULL) { 871 ro = &tp->t_inpcb->inp_route; 872 #ifdef DIAGNOSTIC 873 if (family != AF_INET) 874 panic("tcp_respond: address family mismatch"); 875 if (!in_hosteq(ip->ip_dst, tp->t_inpcb->inp_faddr)) { 876 panic("tcp_respond: ip_dst %x != inp_faddr %x", 877 ntohl(ip->ip_dst.s_addr), 878 ntohl(tp->t_inpcb->inp_faddr.s_addr)); 879 } 880 #endif 881 } 882 #ifdef INET6 883 else if (tp != NULL && tp->t_in6pcb != NULL) { 884 ro = (struct route *)&tp->t_in6pcb->in6p_route; 885 #ifdef DIAGNOSTIC 886 if (family == AF_INET) { 887 if (!IN6_IS_ADDR_V4MAPPED(&tp->t_in6pcb->in6p_faddr)) 888 panic("tcp_respond: not mapped addr"); 889 if (bcmp(&ip->ip_dst, 890 &tp->t_in6pcb->in6p_faddr.s6_addr32[3], 891 sizeof(ip->ip_dst)) != 0) { 892 panic("tcp_respond: ip_dst != in6p_faddr"); 893 } 894 } else if (family == AF_INET6) { 895 if (!IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 896 &tp->t_in6pcb->in6p_faddr)) 897 panic("tcp_respond: ip6_dst != in6p_faddr"); 898 } else 899 panic("tcp_respond: address family mismatch"); 900 #endif 901 } 902 #endif 903 else 904 ro = NULL; 905 906 switch (family) { 907 #ifdef INET 908 case AF_INET: 909 error = ip_output(m, NULL, ro, 910 (tp && tp->t_mtudisc ? IP_MTUDISC : 0), 911 (struct ip_moptions *)0, so); 912 break; 913 #endif 914 #ifdef INET6 915 case AF_INET6: 916 error = ip6_output(m, NULL, ro, 0, NULL, so, NULL); 917 break; 918 #endif 919 default: 920 error = EAFNOSUPPORT; 921 break; 922 } 923 924 return (error); 925 } 926 927 /* 928 * Template TCPCB. Rather than zeroing a new TCPCB and initializing 929 * a bunch of members individually, we maintain this template for the 930 * static and mostly-static components of the TCPCB, and copy it into 931 * the new TCPCB instead. 932 */ 933 static struct tcpcb tcpcb_template = { 934 .t_srtt = TCPTV_SRTTBASE, 935 .t_rttmin = TCPTV_MIN, 936 937 .snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT, 938 .snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT, 939 .snd_numholes = 0, 940 941 .t_partialacks = -1, 942 .t_bytes_acked = 0, 943 }; 944 945 /* 946 * Updates the TCPCB template whenever a parameter that would affect 947 * the template is changed. 948 */ 949 void 950 tcp_tcpcb_template(void) 951 { 952 struct tcpcb *tp = &tcpcb_template; 953 int flags; 954 955 tp->t_peermss = tcp_mssdflt; 956 tp->t_ourmss = tcp_mssdflt; 957 tp->t_segsz = tcp_mssdflt; 958 959 flags = 0; 960 if (tcp_do_rfc1323 && tcp_do_win_scale) 961 flags |= TF_REQ_SCALE; 962 if (tcp_do_rfc1323 && tcp_do_timestamps) 963 flags |= TF_REQ_TSTMP; 964 tp->t_flags = flags; 965 966 /* 967 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 968 * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives 969 * reasonable initial retransmit time. 970 */ 971 tp->t_rttvar = tcp_rttdflt * PR_SLOWHZ << (TCP_RTTVAR_SHIFT + 2 - 1); 972 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), 973 TCPTV_MIN, TCPTV_REXMTMAX); 974 975 /* Keep Alive */ 976 tp->t_keepinit = tcp_keepinit; 977 tp->t_keepidle = tcp_keepidle; 978 tp->t_keepintvl = tcp_keepintvl; 979 tp->t_keepcnt = tcp_keepcnt; 980 tp->t_maxidle = tp->t_keepcnt * tp->t_keepintvl; 981 } 982 983 /* 984 * Create a new TCP control block, making an 985 * empty reassembly queue and hooking it to the argument 986 * protocol control block. 987 */ 988 /* family selects inpcb, or in6pcb */ 989 struct tcpcb * 990 tcp_newtcpcb(int family, void *aux) 991 { 992 #ifdef INET6 993 struct rtentry *rt; 994 #endif 995 struct tcpcb *tp; 996 int i; 997 998 /* XXX Consider using a pool_cache for speed. */ 999 tp = pool_get(&tcpcb_pool, PR_NOWAIT); /* splsoftnet via tcp_usrreq */ 1000 if (tp == NULL) 1001 return (NULL); 1002 memcpy(tp, &tcpcb_template, sizeof(*tp)); 1003 TAILQ_INIT(&tp->segq); 1004 TAILQ_INIT(&tp->timeq); 1005 tp->t_family = family; /* may be overridden later on */ 1006 TAILQ_INIT(&tp->snd_holes); 1007 LIST_INIT(&tp->t_sc); /* XXX can template this */ 1008 1009 /* Don't sweat this loop; hopefully the compiler will unroll it. */ 1010 for (i = 0; i < TCPT_NTIMERS; i++) { 1011 callout_init(&tp->t_timer[i], CALLOUT_MPSAFE); 1012 TCP_TIMER_INIT(tp, i); 1013 } 1014 callout_init(&tp->t_delack_ch, CALLOUT_MPSAFE); 1015 1016 switch (family) { 1017 case AF_INET: 1018 { 1019 struct inpcb *inp = (struct inpcb *)aux; 1020 1021 inp->inp_ip.ip_ttl = ip_defttl; 1022 inp->inp_ppcb = (void *)tp; 1023 1024 tp->t_inpcb = inp; 1025 tp->t_mtudisc = ip_mtudisc; 1026 break; 1027 } 1028 #ifdef INET6 1029 case AF_INET6: 1030 { 1031 struct in6pcb *in6p = (struct in6pcb *)aux; 1032 1033 in6p->in6p_ip6.ip6_hlim = in6_selecthlim(in6p, 1034 (rt = rtcache_validate(&in6p->in6p_route)) != NULL 1035 ? rt->rt_ifp 1036 : NULL); 1037 in6p->in6p_ppcb = (void *)tp; 1038 1039 tp->t_in6pcb = in6p; 1040 /* for IPv6, always try to run path MTU discovery */ 1041 tp->t_mtudisc = 1; 1042 break; 1043 } 1044 #endif /* INET6 */ 1045 default: 1046 for (i = 0; i < TCPT_NTIMERS; i++) 1047 callout_destroy(&tp->t_timer[i]); 1048 callout_destroy(&tp->t_delack_ch); 1049 pool_put(&tcpcb_pool, tp); /* splsoftnet via tcp_usrreq */ 1050 return (NULL); 1051 } 1052 1053 /* 1054 * Initialize our timebase. When we send timestamps, we take 1055 * the delta from tcp_now -- this means each connection always 1056 * gets a timebase of 1, which makes it, among other things, 1057 * more difficult to determine how long a system has been up, 1058 * and thus how many TCP sequence increments have occurred. 1059 * 1060 * We start with 1, because 0 doesn't work with linux, which 1061 * considers timestamp 0 in a SYN packet as a bug and disables 1062 * timestamps. 1063 */ 1064 tp->ts_timebase = tcp_now - 1; 1065 1066 tcp_congctl_select(tp, tcp_congctl_global_name); 1067 1068 return (tp); 1069 } 1070 1071 /* 1072 * Drop a TCP connection, reporting 1073 * the specified error. If connection is synchronized, 1074 * then send a RST to peer. 1075 */ 1076 struct tcpcb * 1077 tcp_drop(struct tcpcb *tp, int errno) 1078 { 1079 struct socket *so = NULL; 1080 1081 #ifdef DIAGNOSTIC 1082 if (tp->t_inpcb && tp->t_in6pcb) 1083 panic("tcp_drop: both t_inpcb and t_in6pcb are set"); 1084 #endif 1085 #ifdef INET 1086 if (tp->t_inpcb) 1087 so = tp->t_inpcb->inp_socket; 1088 #endif 1089 #ifdef INET6 1090 if (tp->t_in6pcb) 1091 so = tp->t_in6pcb->in6p_socket; 1092 #endif 1093 if (!so) 1094 return NULL; 1095 1096 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1097 tp->t_state = TCPS_CLOSED; 1098 (void) tcp_output(tp); 1099 TCP_STATINC(TCP_STAT_DROPS); 1100 } else 1101 TCP_STATINC(TCP_STAT_CONNDROPS); 1102 if (errno == ETIMEDOUT && tp->t_softerror) 1103 errno = tp->t_softerror; 1104 so->so_error = errno; 1105 return (tcp_close(tp)); 1106 } 1107 1108 /* 1109 * Close a TCP control block: 1110 * discard all space held by the tcp 1111 * discard internet protocol block 1112 * wake up any sleepers 1113 */ 1114 struct tcpcb * 1115 tcp_close(struct tcpcb *tp) 1116 { 1117 struct inpcb *inp; 1118 #ifdef INET6 1119 struct in6pcb *in6p; 1120 #endif 1121 struct socket *so; 1122 #ifdef RTV_RTT 1123 struct rtentry *rt; 1124 #endif 1125 struct route *ro; 1126 int j; 1127 1128 inp = tp->t_inpcb; 1129 #ifdef INET6 1130 in6p = tp->t_in6pcb; 1131 #endif 1132 so = NULL; 1133 ro = NULL; 1134 if (inp) { 1135 so = inp->inp_socket; 1136 ro = &inp->inp_route; 1137 } 1138 #ifdef INET6 1139 else if (in6p) { 1140 so = in6p->in6p_socket; 1141 ro = (struct route *)&in6p->in6p_route; 1142 } 1143 #endif 1144 1145 #ifdef RTV_RTT 1146 /* 1147 * If we sent enough data to get some meaningful characteristics, 1148 * save them in the routing entry. 'Enough' is arbitrarily 1149 * defined as the sendpipesize (default 4K) * 16. This would 1150 * give us 16 rtt samples assuming we only get one sample per 1151 * window (the usual case on a long haul net). 16 samples is 1152 * enough for the srtt filter to converge to within 5% of the correct 1153 * value; fewer samples and we could save a very bogus rtt. 1154 * 1155 * Don't update the default route's characteristics and don't 1156 * update anything that the user "locked". 1157 */ 1158 if (SEQ_LT(tp->iss + so->so_snd.sb_hiwat * 16, tp->snd_max) && 1159 ro && (rt = rtcache_validate(ro)) != NULL && 1160 !in_nullhost(satocsin(rt_getkey(rt))->sin_addr)) { 1161 u_long i = 0; 1162 1163 if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) { 1164 i = tp->t_srtt * 1165 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 1166 if (rt->rt_rmx.rmx_rtt && i) 1167 /* 1168 * filter this update to half the old & half 1169 * the new values, converting scale. 1170 * See route.h and tcp_var.h for a 1171 * description of the scaling constants. 1172 */ 1173 rt->rt_rmx.rmx_rtt = 1174 (rt->rt_rmx.rmx_rtt + i) / 2; 1175 else 1176 rt->rt_rmx.rmx_rtt = i; 1177 } 1178 if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) { 1179 i = tp->t_rttvar * 1180 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTTVAR_SHIFT + 2)); 1181 if (rt->rt_rmx.rmx_rttvar && i) 1182 rt->rt_rmx.rmx_rttvar = 1183 (rt->rt_rmx.rmx_rttvar + i) / 2; 1184 else 1185 rt->rt_rmx.rmx_rttvar = i; 1186 } 1187 /* 1188 * update the pipelimit (ssthresh) if it has been updated 1189 * already or if a pipesize was specified & the threshhold 1190 * got below half the pipesize. I.e., wait for bad news 1191 * before we start updating, then update on both good 1192 * and bad news. 1193 */ 1194 if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 && 1195 (i = tp->snd_ssthresh) && rt->rt_rmx.rmx_ssthresh) || 1196 i < (rt->rt_rmx.rmx_sendpipe / 2)) { 1197 /* 1198 * convert the limit from user data bytes to 1199 * packets then to packet data bytes. 1200 */ 1201 i = (i + tp->t_segsz / 2) / tp->t_segsz; 1202 if (i < 2) 1203 i = 2; 1204 i *= (u_long)(tp->t_segsz + sizeof (struct tcpiphdr)); 1205 if (rt->rt_rmx.rmx_ssthresh) 1206 rt->rt_rmx.rmx_ssthresh = 1207 (rt->rt_rmx.rmx_ssthresh + i) / 2; 1208 else 1209 rt->rt_rmx.rmx_ssthresh = i; 1210 } 1211 } 1212 #endif /* RTV_RTT */ 1213 /* free the reassembly queue, if any */ 1214 TCP_REASS_LOCK(tp); 1215 (void) tcp_freeq(tp); 1216 TCP_REASS_UNLOCK(tp); 1217 1218 /* free the SACK holes list. */ 1219 tcp_free_sackholes(tp); 1220 1221 tcp_congctl_release(tp); 1222 1223 tcp_canceltimers(tp); 1224 TCP_CLEAR_DELACK(tp); 1225 syn_cache_cleanup(tp); 1226 1227 if (tp->t_template) { 1228 m_free(tp->t_template); 1229 tp->t_template = NULL; 1230 } 1231 tp->t_flags |= TF_DEAD; 1232 for (j = 0; j < TCPT_NTIMERS; j++) { 1233 callout_halt(&tp->t_timer[j], softnet_lock); 1234 callout_destroy(&tp->t_timer[j]); 1235 } 1236 callout_halt(&tp->t_delack_ch, softnet_lock); 1237 callout_destroy(&tp->t_delack_ch); 1238 pool_put(&tcpcb_pool, tp); 1239 1240 if (inp) { 1241 inp->inp_ppcb = 0; 1242 soisdisconnected(so); 1243 in_pcbdetach(inp); 1244 } 1245 #ifdef INET6 1246 else if (in6p) { 1247 in6p->in6p_ppcb = 0; 1248 soisdisconnected(so); 1249 in6_pcbdetach(in6p); 1250 } 1251 #endif 1252 TCP_STATINC(TCP_STAT_CLOSED); 1253 return ((struct tcpcb *)0); 1254 } 1255 1256 int 1257 tcp_freeq(struct tcpcb *tp) 1258 { 1259 struct ipqent *qe; 1260 int rv = 0; 1261 #ifdef TCPREASS_DEBUG 1262 int i = 0; 1263 #endif 1264 1265 TCP_REASS_LOCK_CHECK(tp); 1266 1267 while ((qe = TAILQ_FIRST(&tp->segq)) != NULL) { 1268 #ifdef TCPREASS_DEBUG 1269 printf("tcp_freeq[%p,%d]: %u:%u(%u) 0x%02x\n", 1270 tp, i++, qe->ipqe_seq, qe->ipqe_seq + qe->ipqe_len, 1271 qe->ipqe_len, qe->ipqe_flags & (TH_SYN|TH_FIN|TH_RST)); 1272 #endif 1273 TAILQ_REMOVE(&tp->segq, qe, ipqe_q); 1274 TAILQ_REMOVE(&tp->timeq, qe, ipqe_timeq); 1275 m_freem(qe->ipqe_m); 1276 tcpipqent_free(qe); 1277 rv = 1; 1278 } 1279 tp->t_segqlen = 0; 1280 KASSERT(TAILQ_EMPTY(&tp->timeq)); 1281 return (rv); 1282 } 1283 1284 /* 1285 * Protocol drain routine. Called when memory is in short supply. 1286 */ 1287 void 1288 tcp_drain(void) 1289 { 1290 struct inpcb_hdr *inph; 1291 struct tcpcb *tp; 1292 1293 mutex_enter(softnet_lock); 1294 KERNEL_LOCK(1, NULL); 1295 1296 /* 1297 * Free the sequence queue of all TCP connections. 1298 */ 1299 CIRCLEQ_FOREACH(inph, &tcbtable.inpt_queue, inph_queue) { 1300 switch (inph->inph_af) { 1301 case AF_INET: 1302 tp = intotcpcb((struct inpcb *)inph); 1303 break; 1304 #ifdef INET6 1305 case AF_INET6: 1306 tp = in6totcpcb((struct in6pcb *)inph); 1307 break; 1308 #endif 1309 default: 1310 tp = NULL; 1311 break; 1312 } 1313 if (tp != NULL) { 1314 /* 1315 * We may be called from a device's interrupt 1316 * context. If the tcpcb is already busy, 1317 * just bail out now. 1318 */ 1319 if (tcp_reass_lock_try(tp) == 0) 1320 continue; 1321 if (tcp_freeq(tp)) 1322 TCP_STATINC(TCP_STAT_CONNSDRAINED); 1323 TCP_REASS_UNLOCK(tp); 1324 } 1325 } 1326 1327 KERNEL_UNLOCK_ONE(NULL); 1328 mutex_exit(softnet_lock); 1329 } 1330 1331 /* 1332 * Notify a tcp user of an asynchronous error; 1333 * store error as soft error, but wake up user 1334 * (for now, won't do anything until can select for soft error). 1335 */ 1336 void 1337 tcp_notify(struct inpcb *inp, int error) 1338 { 1339 struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb; 1340 struct socket *so = inp->inp_socket; 1341 1342 /* 1343 * Ignore some errors if we are hooked up. 1344 * If connection hasn't completed, has retransmitted several times, 1345 * and receives a second error, give up now. This is better 1346 * than waiting a long time to establish a connection that 1347 * can never complete. 1348 */ 1349 if (tp->t_state == TCPS_ESTABLISHED && 1350 (error == EHOSTUNREACH || error == ENETUNREACH || 1351 error == EHOSTDOWN)) { 1352 return; 1353 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1354 tp->t_rxtshift > 3 && tp->t_softerror) 1355 so->so_error = error; 1356 else 1357 tp->t_softerror = error; 1358 cv_broadcast(&so->so_cv); 1359 sorwakeup(so); 1360 sowwakeup(so); 1361 } 1362 1363 #ifdef INET6 1364 void 1365 tcp6_notify(struct in6pcb *in6p, int error) 1366 { 1367 struct tcpcb *tp = (struct tcpcb *)in6p->in6p_ppcb; 1368 struct socket *so = in6p->in6p_socket; 1369 1370 /* 1371 * Ignore some errors if we are hooked up. 1372 * If connection hasn't completed, has retransmitted several times, 1373 * and receives a second error, give up now. This is better 1374 * than waiting a long time to establish a connection that 1375 * can never complete. 1376 */ 1377 if (tp->t_state == TCPS_ESTABLISHED && 1378 (error == EHOSTUNREACH || error == ENETUNREACH || 1379 error == EHOSTDOWN)) { 1380 return; 1381 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1382 tp->t_rxtshift > 3 && tp->t_softerror) 1383 so->so_error = error; 1384 else 1385 tp->t_softerror = error; 1386 cv_broadcast(&so->so_cv); 1387 sorwakeup(so); 1388 sowwakeup(so); 1389 } 1390 #endif 1391 1392 #ifdef INET6 1393 void * 1394 tcp6_ctlinput(int cmd, const struct sockaddr *sa, void *d) 1395 { 1396 struct tcphdr th; 1397 void (*notify)(struct in6pcb *, int) = tcp6_notify; 1398 int nmatch; 1399 struct ip6_hdr *ip6; 1400 const struct sockaddr_in6 *sa6_src = NULL; 1401 const struct sockaddr_in6 *sa6 = (const struct sockaddr_in6 *)sa; 1402 struct mbuf *m; 1403 int off; 1404 1405 if (sa->sa_family != AF_INET6 || 1406 sa->sa_len != sizeof(struct sockaddr_in6)) 1407 return NULL; 1408 if ((unsigned)cmd >= PRC_NCMDS) 1409 return NULL; 1410 else if (cmd == PRC_QUENCH) { 1411 /* 1412 * Don't honor ICMP Source Quench messages meant for 1413 * TCP connections. 1414 */ 1415 return NULL; 1416 } else if (PRC_IS_REDIRECT(cmd)) 1417 notify = in6_rtchange, d = NULL; 1418 else if (cmd == PRC_MSGSIZE) 1419 ; /* special code is present, see below */ 1420 else if (cmd == PRC_HOSTDEAD) 1421 d = NULL; 1422 else if (inet6ctlerrmap[cmd] == 0) 1423 return NULL; 1424 1425 /* if the parameter is from icmp6, decode it. */ 1426 if (d != NULL) { 1427 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 1428 m = ip6cp->ip6c_m; 1429 ip6 = ip6cp->ip6c_ip6; 1430 off = ip6cp->ip6c_off; 1431 sa6_src = ip6cp->ip6c_src; 1432 } else { 1433 m = NULL; 1434 ip6 = NULL; 1435 sa6_src = &sa6_any; 1436 off = 0; 1437 } 1438 1439 if (ip6) { 1440 /* 1441 * XXX: We assume that when ip6 is non NULL, 1442 * M and OFF are valid. 1443 */ 1444 1445 /* check if we can safely examine src and dst ports */ 1446 if (m->m_pkthdr.len < off + sizeof(th)) { 1447 if (cmd == PRC_MSGSIZE) 1448 icmp6_mtudisc_update((struct ip6ctlparam *)d, 0); 1449 return NULL; 1450 } 1451 1452 bzero(&th, sizeof(th)); 1453 m_copydata(m, off, sizeof(th), (void *)&th); 1454 1455 if (cmd == PRC_MSGSIZE) { 1456 int valid = 0; 1457 1458 /* 1459 * Check to see if we have a valid TCP connection 1460 * corresponding to the address in the ICMPv6 message 1461 * payload. 1462 */ 1463 if (in6_pcblookup_connect(&tcbtable, &sa6->sin6_addr, 1464 th.th_dport, 1465 (const struct in6_addr *)&sa6_src->sin6_addr, 1466 th.th_sport, 0)) 1467 valid++; 1468 1469 /* 1470 * Depending on the value of "valid" and routing table 1471 * size (mtudisc_{hi,lo}wat), we will: 1472 * - recalcurate the new MTU and create the 1473 * corresponding routing entry, or 1474 * - ignore the MTU change notification. 1475 */ 1476 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid); 1477 1478 /* 1479 * no need to call in6_pcbnotify, it should have been 1480 * called via callback if necessary 1481 */ 1482 return NULL; 1483 } 1484 1485 nmatch = in6_pcbnotify(&tcbtable, sa, th.th_dport, 1486 (const struct sockaddr *)sa6_src, th.th_sport, cmd, NULL, notify); 1487 if (nmatch == 0 && syn_cache_count && 1488 (inet6ctlerrmap[cmd] == EHOSTUNREACH || 1489 inet6ctlerrmap[cmd] == ENETUNREACH || 1490 inet6ctlerrmap[cmd] == EHOSTDOWN)) 1491 syn_cache_unreach((const struct sockaddr *)sa6_src, 1492 sa, &th); 1493 } else { 1494 (void) in6_pcbnotify(&tcbtable, sa, 0, 1495 (const struct sockaddr *)sa6_src, 0, cmd, NULL, notify); 1496 } 1497 1498 return NULL; 1499 } 1500 #endif 1501 1502 #ifdef INET 1503 /* assumes that ip header and tcp header are contiguous on mbuf */ 1504 void * 1505 tcp_ctlinput(int cmd, const struct sockaddr *sa, void *v) 1506 { 1507 struct ip *ip = v; 1508 struct tcphdr *th; 1509 struct icmp *icp; 1510 extern const int inetctlerrmap[]; 1511 void (*notify)(struct inpcb *, int) = tcp_notify; 1512 int errno; 1513 int nmatch; 1514 struct tcpcb *tp; 1515 u_int mtu; 1516 tcp_seq seq; 1517 struct inpcb *inp; 1518 #ifdef INET6 1519 struct in6pcb *in6p; 1520 struct in6_addr src6, dst6; 1521 #endif 1522 1523 if (sa->sa_family != AF_INET || 1524 sa->sa_len != sizeof(struct sockaddr_in)) 1525 return NULL; 1526 if ((unsigned)cmd >= PRC_NCMDS) 1527 return NULL; 1528 errno = inetctlerrmap[cmd]; 1529 if (cmd == PRC_QUENCH) 1530 /* 1531 * Don't honor ICMP Source Quench messages meant for 1532 * TCP connections. 1533 */ 1534 return NULL; 1535 else if (PRC_IS_REDIRECT(cmd)) 1536 notify = in_rtchange, ip = 0; 1537 else if (cmd == PRC_MSGSIZE && ip && ip->ip_v == 4) { 1538 /* 1539 * Check to see if we have a valid TCP connection 1540 * corresponding to the address in the ICMP message 1541 * payload. 1542 * 1543 * Boundary check is made in icmp_input(), with ICMP_ADVLENMIN. 1544 */ 1545 th = (struct tcphdr *)((char *)ip + (ip->ip_hl << 2)); 1546 #ifdef INET6 1547 memset(&src6, 0, sizeof(src6)); 1548 memset(&dst6, 0, sizeof(dst6)); 1549 src6.s6_addr16[5] = dst6.s6_addr16[5] = 0xffff; 1550 memcpy(&src6.s6_addr32[3], &ip->ip_src, sizeof(struct in_addr)); 1551 memcpy(&dst6.s6_addr32[3], &ip->ip_dst, sizeof(struct in_addr)); 1552 #endif 1553 if ((inp = in_pcblookup_connect(&tcbtable, ip->ip_dst, 1554 th->th_dport, ip->ip_src, th->th_sport)) != NULL) 1555 #ifdef INET6 1556 in6p = NULL; 1557 #else 1558 ; 1559 #endif 1560 #ifdef INET6 1561 else if ((in6p = in6_pcblookup_connect(&tcbtable, &dst6, 1562 th->th_dport, &src6, th->th_sport, 0)) != NULL) 1563 ; 1564 #endif 1565 else 1566 return NULL; 1567 1568 /* 1569 * Now that we've validated that we are actually communicating 1570 * with the host indicated in the ICMP message, locate the 1571 * ICMP header, recalculate the new MTU, and create the 1572 * corresponding routing entry. 1573 */ 1574 icp = (struct icmp *)((char *)ip - 1575 offsetof(struct icmp, icmp_ip)); 1576 if (inp) { 1577 if ((tp = intotcpcb(inp)) == NULL) 1578 return NULL; 1579 } 1580 #ifdef INET6 1581 else if (in6p) { 1582 if ((tp = in6totcpcb(in6p)) == NULL) 1583 return NULL; 1584 } 1585 #endif 1586 else 1587 return NULL; 1588 seq = ntohl(th->th_seq); 1589 if (SEQ_LT(seq, tp->snd_una) || SEQ_GT(seq, tp->snd_max)) 1590 return NULL; 1591 /* 1592 * If the ICMP message advertises a Next-Hop MTU 1593 * equal or larger than the maximum packet size we have 1594 * ever sent, drop the message. 1595 */ 1596 mtu = (u_int)ntohs(icp->icmp_nextmtu); 1597 if (mtu >= tp->t_pmtud_mtu_sent) 1598 return NULL; 1599 if (mtu >= tcp_hdrsz(tp) + tp->t_pmtud_mss_acked) { 1600 /* 1601 * Calculate new MTU, and create corresponding 1602 * route (traditional PMTUD). 1603 */ 1604 tp->t_flags &= ~TF_PMTUD_PEND; 1605 icmp_mtudisc(icp, ip->ip_dst); 1606 } else { 1607 /* 1608 * Record the information got in the ICMP 1609 * message; act on it later. 1610 * If we had already recorded an ICMP message, 1611 * replace the old one only if the new message 1612 * refers to an older TCP segment 1613 */ 1614 if (tp->t_flags & TF_PMTUD_PEND) { 1615 if (SEQ_LT(tp->t_pmtud_th_seq, seq)) 1616 return NULL; 1617 } else 1618 tp->t_flags |= TF_PMTUD_PEND; 1619 tp->t_pmtud_th_seq = seq; 1620 tp->t_pmtud_nextmtu = icp->icmp_nextmtu; 1621 tp->t_pmtud_ip_len = icp->icmp_ip.ip_len; 1622 tp->t_pmtud_ip_hl = icp->icmp_ip.ip_hl; 1623 } 1624 return NULL; 1625 } else if (cmd == PRC_HOSTDEAD) 1626 ip = 0; 1627 else if (errno == 0) 1628 return NULL; 1629 if (ip && ip->ip_v == 4 && sa->sa_family == AF_INET) { 1630 th = (struct tcphdr *)((char *)ip + (ip->ip_hl << 2)); 1631 nmatch = in_pcbnotify(&tcbtable, satocsin(sa)->sin_addr, 1632 th->th_dport, ip->ip_src, th->th_sport, errno, notify); 1633 if (nmatch == 0 && syn_cache_count && 1634 (inetctlerrmap[cmd] == EHOSTUNREACH || 1635 inetctlerrmap[cmd] == ENETUNREACH || 1636 inetctlerrmap[cmd] == EHOSTDOWN)) { 1637 struct sockaddr_in sin; 1638 bzero(&sin, sizeof(sin)); 1639 sin.sin_len = sizeof(sin); 1640 sin.sin_family = AF_INET; 1641 sin.sin_port = th->th_sport; 1642 sin.sin_addr = ip->ip_src; 1643 syn_cache_unreach((struct sockaddr *)&sin, sa, th); 1644 } 1645 1646 /* XXX mapped address case */ 1647 } else 1648 in_pcbnotifyall(&tcbtable, satocsin(sa)->sin_addr, errno, 1649 notify); 1650 return NULL; 1651 } 1652 1653 /* 1654 * When a source quench is received, we are being notified of congestion. 1655 * Close the congestion window down to the Loss Window (one segment). 1656 * We will gradually open it again as we proceed. 1657 */ 1658 void 1659 tcp_quench(struct inpcb *inp, int errno) 1660 { 1661 struct tcpcb *tp = intotcpcb(inp); 1662 1663 if (tp) { 1664 tp->snd_cwnd = tp->t_segsz; 1665 tp->t_bytes_acked = 0; 1666 } 1667 } 1668 #endif 1669 1670 #ifdef INET6 1671 void 1672 tcp6_quench(struct in6pcb *in6p, int errno) 1673 { 1674 struct tcpcb *tp = in6totcpcb(in6p); 1675 1676 if (tp) { 1677 tp->snd_cwnd = tp->t_segsz; 1678 tp->t_bytes_acked = 0; 1679 } 1680 } 1681 #endif 1682 1683 #ifdef INET 1684 /* 1685 * Path MTU Discovery handlers. 1686 */ 1687 void 1688 tcp_mtudisc_callback(struct in_addr faddr) 1689 { 1690 #ifdef INET6 1691 struct in6_addr in6; 1692 #endif 1693 1694 in_pcbnotifyall(&tcbtable, faddr, EMSGSIZE, tcp_mtudisc); 1695 #ifdef INET6 1696 memset(&in6, 0, sizeof(in6)); 1697 in6.s6_addr16[5] = 0xffff; 1698 memcpy(&in6.s6_addr32[3], &faddr, sizeof(struct in_addr)); 1699 tcp6_mtudisc_callback(&in6); 1700 #endif 1701 } 1702 1703 /* 1704 * On receipt of path MTU corrections, flush old route and replace it 1705 * with the new one. Retransmit all unacknowledged packets, to ensure 1706 * that all packets will be received. 1707 */ 1708 void 1709 tcp_mtudisc(struct inpcb *inp, int errno) 1710 { 1711 struct tcpcb *tp = intotcpcb(inp); 1712 struct rtentry *rt = in_pcbrtentry(inp); 1713 1714 if (tp != 0) { 1715 if (rt != 0) { 1716 /* 1717 * If this was not a host route, remove and realloc. 1718 */ 1719 if ((rt->rt_flags & RTF_HOST) == 0) { 1720 in_rtchange(inp, errno); 1721 if ((rt = in_pcbrtentry(inp)) == 0) 1722 return; 1723 } 1724 1725 /* 1726 * Slow start out of the error condition. We 1727 * use the MTU because we know it's smaller 1728 * than the previously transmitted segment. 1729 * 1730 * Note: This is more conservative than the 1731 * suggestion in draft-floyd-incr-init-win-03. 1732 */ 1733 if (rt->rt_rmx.rmx_mtu != 0) 1734 tp->snd_cwnd = 1735 TCP_INITIAL_WINDOW(tcp_init_win, 1736 rt->rt_rmx.rmx_mtu); 1737 } 1738 1739 /* 1740 * Resend unacknowledged packets. 1741 */ 1742 tp->snd_nxt = tp->sack_newdata = tp->snd_una; 1743 tcp_output(tp); 1744 } 1745 } 1746 #endif 1747 1748 #ifdef INET6 1749 /* 1750 * Path MTU Discovery handlers. 1751 */ 1752 void 1753 tcp6_mtudisc_callback(struct in6_addr *faddr) 1754 { 1755 struct sockaddr_in6 sin6; 1756 1757 bzero(&sin6, sizeof(sin6)); 1758 sin6.sin6_family = AF_INET6; 1759 sin6.sin6_len = sizeof(struct sockaddr_in6); 1760 sin6.sin6_addr = *faddr; 1761 (void) in6_pcbnotify(&tcbtable, (struct sockaddr *)&sin6, 0, 1762 (const struct sockaddr *)&sa6_any, 0, PRC_MSGSIZE, NULL, tcp6_mtudisc); 1763 } 1764 1765 void 1766 tcp6_mtudisc(struct in6pcb *in6p, int errno) 1767 { 1768 struct tcpcb *tp = in6totcpcb(in6p); 1769 struct rtentry *rt = in6_pcbrtentry(in6p); 1770 1771 if (tp != 0) { 1772 if (rt != 0) { 1773 /* 1774 * If this was not a host route, remove and realloc. 1775 */ 1776 if ((rt->rt_flags & RTF_HOST) == 0) { 1777 in6_rtchange(in6p, errno); 1778 if ((rt = in6_pcbrtentry(in6p)) == 0) 1779 return; 1780 } 1781 1782 /* 1783 * Slow start out of the error condition. We 1784 * use the MTU because we know it's smaller 1785 * than the previously transmitted segment. 1786 * 1787 * Note: This is more conservative than the 1788 * suggestion in draft-floyd-incr-init-win-03. 1789 */ 1790 if (rt->rt_rmx.rmx_mtu != 0) 1791 tp->snd_cwnd = 1792 TCP_INITIAL_WINDOW(tcp_init_win, 1793 rt->rt_rmx.rmx_mtu); 1794 } 1795 1796 /* 1797 * Resend unacknowledged packets. 1798 */ 1799 tp->snd_nxt = tp->sack_newdata = tp->snd_una; 1800 tcp_output(tp); 1801 } 1802 } 1803 #endif /* INET6 */ 1804 1805 /* 1806 * Compute the MSS to advertise to the peer. Called only during 1807 * the 3-way handshake. If we are the server (peer initiated 1808 * connection), we are called with a pointer to the interface 1809 * on which the SYN packet arrived. If we are the client (we 1810 * initiated connection), we are called with a pointer to the 1811 * interface out which this connection should go. 1812 * 1813 * NOTE: Do not subtract IP option/extension header size nor IPsec 1814 * header size from MSS advertisement. MSS option must hold the maximum 1815 * segment size we can accept, so it must always be: 1816 * max(if mtu) - ip header - tcp header 1817 */ 1818 u_long 1819 tcp_mss_to_advertise(const struct ifnet *ifp, int af) 1820 { 1821 extern u_long in_maxmtu; 1822 u_long mss = 0; 1823 u_long hdrsiz; 1824 1825 /* 1826 * In order to avoid defeating path MTU discovery on the peer, 1827 * we advertise the max MTU of all attached networks as our MSS, 1828 * per RFC 1191, section 3.1. 1829 * 1830 * We provide the option to advertise just the MTU of 1831 * the interface on which we hope this connection will 1832 * be receiving. If we are responding to a SYN, we 1833 * will have a pretty good idea about this, but when 1834 * initiating a connection there is a bit more doubt. 1835 * 1836 * We also need to ensure that loopback has a large enough 1837 * MSS, as the loopback MTU is never included in in_maxmtu. 1838 */ 1839 1840 if (ifp != NULL) 1841 switch (af) { 1842 case AF_INET: 1843 mss = ifp->if_mtu; 1844 break; 1845 #ifdef INET6 1846 case AF_INET6: 1847 mss = IN6_LINKMTU(ifp); 1848 break; 1849 #endif 1850 } 1851 1852 if (tcp_mss_ifmtu == 0) 1853 switch (af) { 1854 case AF_INET: 1855 mss = max(in_maxmtu, mss); 1856 break; 1857 #ifdef INET6 1858 case AF_INET6: 1859 mss = max(in6_maxmtu, mss); 1860 break; 1861 #endif 1862 } 1863 1864 switch (af) { 1865 case AF_INET: 1866 hdrsiz = sizeof(struct ip); 1867 break; 1868 #ifdef INET6 1869 case AF_INET6: 1870 hdrsiz = sizeof(struct ip6_hdr); 1871 break; 1872 #endif 1873 default: 1874 hdrsiz = 0; 1875 break; 1876 } 1877 hdrsiz += sizeof(struct tcphdr); 1878 if (mss > hdrsiz) 1879 mss -= hdrsiz; 1880 1881 mss = max(tcp_mssdflt, mss); 1882 return (mss); 1883 } 1884 1885 /* 1886 * Set connection variables based on the peer's advertised MSS. 1887 * We are passed the TCPCB for the actual connection. If we 1888 * are the server, we are called by the compressed state engine 1889 * when the 3-way handshake is complete. If we are the client, 1890 * we are called when we receive the SYN,ACK from the server. 1891 * 1892 * NOTE: Our advertised MSS value must be initialized in the TCPCB 1893 * before this routine is called! 1894 */ 1895 void 1896 tcp_mss_from_peer(struct tcpcb *tp, int offer) 1897 { 1898 struct socket *so; 1899 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1900 struct rtentry *rt; 1901 #endif 1902 u_long bufsize; 1903 int mss; 1904 1905 #ifdef DIAGNOSTIC 1906 if (tp->t_inpcb && tp->t_in6pcb) 1907 panic("tcp_mss_from_peer: both t_inpcb and t_in6pcb are set"); 1908 #endif 1909 so = NULL; 1910 rt = NULL; 1911 #ifdef INET 1912 if (tp->t_inpcb) { 1913 so = tp->t_inpcb->inp_socket; 1914 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1915 rt = in_pcbrtentry(tp->t_inpcb); 1916 #endif 1917 } 1918 #endif 1919 #ifdef INET6 1920 if (tp->t_in6pcb) { 1921 so = tp->t_in6pcb->in6p_socket; 1922 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1923 rt = in6_pcbrtentry(tp->t_in6pcb); 1924 #endif 1925 } 1926 #endif 1927 1928 /* 1929 * As per RFC1122, use the default MSS value, unless they 1930 * sent us an offer. Do not accept offers less than 256 bytes. 1931 */ 1932 mss = tcp_mssdflt; 1933 if (offer) 1934 mss = offer; 1935 mss = max(mss, 256); /* sanity */ 1936 tp->t_peermss = mss; 1937 mss -= tcp_optlen(tp); 1938 #ifdef INET 1939 if (tp->t_inpcb) 1940 mss -= ip_optlen(tp->t_inpcb); 1941 #endif 1942 #ifdef INET6 1943 if (tp->t_in6pcb) 1944 mss -= ip6_optlen(tp->t_in6pcb); 1945 #endif 1946 1947 /* 1948 * If there's a pipesize, change the socket buffer to that size. 1949 * Make the socket buffer an integral number of MSS units. If 1950 * the MSS is larger than the socket buffer, artificially decrease 1951 * the MSS. 1952 */ 1953 #ifdef RTV_SPIPE 1954 if (rt != NULL && rt->rt_rmx.rmx_sendpipe != 0) 1955 bufsize = rt->rt_rmx.rmx_sendpipe; 1956 else 1957 #endif 1958 { 1959 KASSERT(so != NULL); 1960 bufsize = so->so_snd.sb_hiwat; 1961 } 1962 if (bufsize < mss) 1963 mss = bufsize; 1964 else { 1965 bufsize = roundup(bufsize, mss); 1966 if (bufsize > sb_max) 1967 bufsize = sb_max; 1968 (void) sbreserve(&so->so_snd, bufsize, so); 1969 } 1970 tp->t_segsz = mss; 1971 1972 #ifdef RTV_SSTHRESH 1973 if (rt != NULL && rt->rt_rmx.rmx_ssthresh) { 1974 /* 1975 * There's some sort of gateway or interface buffer 1976 * limit on the path. Use this to set the slow 1977 * start threshold, but set the threshold to no less 1978 * than 2 * MSS. 1979 */ 1980 tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh); 1981 } 1982 #endif 1983 } 1984 1985 /* 1986 * Processing necessary when a TCP connection is established. 1987 */ 1988 void 1989 tcp_established(struct tcpcb *tp) 1990 { 1991 struct socket *so; 1992 #ifdef RTV_RPIPE 1993 struct rtentry *rt; 1994 #endif 1995 u_long bufsize; 1996 1997 #ifdef DIAGNOSTIC 1998 if (tp->t_inpcb && tp->t_in6pcb) 1999 panic("tcp_established: both t_inpcb and t_in6pcb are set"); 2000 #endif 2001 so = NULL; 2002 rt = NULL; 2003 #ifdef INET 2004 if (tp->t_inpcb) { 2005 so = tp->t_inpcb->inp_socket; 2006 #if defined(RTV_RPIPE) 2007 rt = in_pcbrtentry(tp->t_inpcb); 2008 #endif 2009 } 2010 #endif 2011 #ifdef INET6 2012 if (tp->t_in6pcb) { 2013 so = tp->t_in6pcb->in6p_socket; 2014 #if defined(RTV_RPIPE) 2015 rt = in6_pcbrtentry(tp->t_in6pcb); 2016 #endif 2017 } 2018 #endif 2019 2020 tp->t_state = TCPS_ESTABLISHED; 2021 TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepidle); 2022 2023 #ifdef RTV_RPIPE 2024 if (rt != NULL && rt->rt_rmx.rmx_recvpipe != 0) 2025 bufsize = rt->rt_rmx.rmx_recvpipe; 2026 else 2027 #endif 2028 { 2029 KASSERT(so != NULL); 2030 bufsize = so->so_rcv.sb_hiwat; 2031 } 2032 if (bufsize > tp->t_ourmss) { 2033 bufsize = roundup(bufsize, tp->t_ourmss); 2034 if (bufsize > sb_max) 2035 bufsize = sb_max; 2036 (void) sbreserve(&so->so_rcv, bufsize, so); 2037 } 2038 } 2039 2040 /* 2041 * Check if there's an initial rtt or rttvar. Convert from the 2042 * route-table units to scaled multiples of the slow timeout timer. 2043 * Called only during the 3-way handshake. 2044 */ 2045 void 2046 tcp_rmx_rtt(struct tcpcb *tp) 2047 { 2048 #ifdef RTV_RTT 2049 struct rtentry *rt = NULL; 2050 int rtt; 2051 2052 #ifdef DIAGNOSTIC 2053 if (tp->t_inpcb && tp->t_in6pcb) 2054 panic("tcp_rmx_rtt: both t_inpcb and t_in6pcb are set"); 2055 #endif 2056 #ifdef INET 2057 if (tp->t_inpcb) 2058 rt = in_pcbrtentry(tp->t_inpcb); 2059 #endif 2060 #ifdef INET6 2061 if (tp->t_in6pcb) 2062 rt = in6_pcbrtentry(tp->t_in6pcb); 2063 #endif 2064 if (rt == NULL) 2065 return; 2066 2067 if (tp->t_srtt == 0 && (rtt = rt->rt_rmx.rmx_rtt)) { 2068 /* 2069 * XXX The lock bit for MTU indicates that the value 2070 * is also a minimum value; this is subject to time. 2071 */ 2072 if (rt->rt_rmx.rmx_locks & RTV_RTT) 2073 TCPT_RANGESET(tp->t_rttmin, 2074 rtt / (RTM_RTTUNIT / PR_SLOWHZ), 2075 TCPTV_MIN, TCPTV_REXMTMAX); 2076 tp->t_srtt = rtt / 2077 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 2078 if (rt->rt_rmx.rmx_rttvar) { 2079 tp->t_rttvar = rt->rt_rmx.rmx_rttvar / 2080 ((RTM_RTTUNIT / PR_SLOWHZ) >> 2081 (TCP_RTTVAR_SHIFT + 2)); 2082 } else { 2083 /* Default variation is +- 1 rtt */ 2084 tp->t_rttvar = 2085 tp->t_srtt >> (TCP_RTT_SHIFT - TCP_RTTVAR_SHIFT); 2086 } 2087 TCPT_RANGESET(tp->t_rxtcur, 2088 ((tp->t_srtt >> 2) + tp->t_rttvar) >> (1 + 2), 2089 tp->t_rttmin, TCPTV_REXMTMAX); 2090 } 2091 #endif 2092 } 2093 2094 tcp_seq tcp_iss_seq = 0; /* tcp initial seq # */ 2095 #if NRND > 0 2096 u_int8_t tcp_iss_secret[16]; /* 128 bits; should be plenty */ 2097 #endif 2098 2099 /* 2100 * Get a new sequence value given a tcp control block 2101 */ 2102 tcp_seq 2103 tcp_new_iss(struct tcpcb *tp, tcp_seq addin) 2104 { 2105 2106 #ifdef INET 2107 if (tp->t_inpcb != NULL) { 2108 return (tcp_new_iss1(&tp->t_inpcb->inp_laddr, 2109 &tp->t_inpcb->inp_faddr, tp->t_inpcb->inp_lport, 2110 tp->t_inpcb->inp_fport, sizeof(tp->t_inpcb->inp_laddr), 2111 addin)); 2112 } 2113 #endif 2114 #ifdef INET6 2115 if (tp->t_in6pcb != NULL) { 2116 return (tcp_new_iss1(&tp->t_in6pcb->in6p_laddr, 2117 &tp->t_in6pcb->in6p_faddr, tp->t_in6pcb->in6p_lport, 2118 tp->t_in6pcb->in6p_fport, sizeof(tp->t_in6pcb->in6p_laddr), 2119 addin)); 2120 } 2121 #endif 2122 /* Not possible. */ 2123 panic("tcp_new_iss"); 2124 } 2125 2126 /* 2127 * This routine actually generates a new TCP initial sequence number. 2128 */ 2129 tcp_seq 2130 tcp_new_iss1(void *laddr, void *faddr, u_int16_t lport, u_int16_t fport, 2131 size_t addrsz, tcp_seq addin) 2132 { 2133 tcp_seq tcp_iss; 2134 2135 #if NRND > 0 2136 static bool tcp_iss_gotten_secret; 2137 2138 /* 2139 * If we haven't been here before, initialize our cryptographic 2140 * hash secret. 2141 */ 2142 if (tcp_iss_gotten_secret == false) { 2143 rnd_extract_data(tcp_iss_secret, sizeof(tcp_iss_secret), 2144 RND_EXTRACT_ANY); 2145 tcp_iss_gotten_secret = true; 2146 } 2147 2148 if (tcp_do_rfc1948) { 2149 MD5_CTX ctx; 2150 u_int8_t hash[16]; /* XXX MD5 knowledge */ 2151 2152 /* 2153 * Compute the base value of the ISS. It is a hash 2154 * of (saddr, sport, daddr, dport, secret). 2155 */ 2156 MD5Init(&ctx); 2157 2158 MD5Update(&ctx, (u_char *) laddr, addrsz); 2159 MD5Update(&ctx, (u_char *) &lport, sizeof(lport)); 2160 2161 MD5Update(&ctx, (u_char *) faddr, addrsz); 2162 MD5Update(&ctx, (u_char *) &fport, sizeof(fport)); 2163 2164 MD5Update(&ctx, tcp_iss_secret, sizeof(tcp_iss_secret)); 2165 2166 MD5Final(hash, &ctx); 2167 2168 memcpy(&tcp_iss, hash, sizeof(tcp_iss)); 2169 2170 /* 2171 * Now increment our "timer", and add it in to 2172 * the computed value. 2173 * 2174 * XXX Use `addin'? 2175 * XXX TCP_ISSINCR too large to use? 2176 */ 2177 tcp_iss_seq += TCP_ISSINCR; 2178 #ifdef TCPISS_DEBUG 2179 printf("ISS hash 0x%08x, ", tcp_iss); 2180 #endif 2181 tcp_iss += tcp_iss_seq + addin; 2182 #ifdef TCPISS_DEBUG 2183 printf("new ISS 0x%08x\n", tcp_iss); 2184 #endif 2185 } else 2186 #endif /* NRND > 0 */ 2187 { 2188 /* 2189 * Randomize. 2190 */ 2191 #if NRND > 0 2192 rnd_extract_data(&tcp_iss, sizeof(tcp_iss), RND_EXTRACT_ANY); 2193 #else 2194 tcp_iss = arc4random(); 2195 #endif 2196 2197 /* 2198 * If we were asked to add some amount to a known value, 2199 * we will take a random value obtained above, mask off 2200 * the upper bits, and add in the known value. We also 2201 * add in a constant to ensure that we are at least a 2202 * certain distance from the original value. 2203 * 2204 * This is used when an old connection is in timed wait 2205 * and we have a new one coming in, for instance. 2206 */ 2207 if (addin != 0) { 2208 #ifdef TCPISS_DEBUG 2209 printf("Random %08x, ", tcp_iss); 2210 #endif 2211 tcp_iss &= TCP_ISS_RANDOM_MASK; 2212 tcp_iss += addin + TCP_ISSINCR; 2213 #ifdef TCPISS_DEBUG 2214 printf("Old ISS %08x, ISS %08x\n", addin, tcp_iss); 2215 #endif 2216 } else { 2217 tcp_iss &= TCP_ISS_RANDOM_MASK; 2218 tcp_iss += tcp_iss_seq; 2219 tcp_iss_seq += TCP_ISSINCR; 2220 #ifdef TCPISS_DEBUG 2221 printf("ISS %08x\n", tcp_iss); 2222 #endif 2223 } 2224 } 2225 2226 if (tcp_compat_42) { 2227 /* 2228 * Limit it to the positive range for really old TCP 2229 * implementations. 2230 * Just AND off the top bit instead of checking if 2231 * is set first - saves a branch 50% of the time. 2232 */ 2233 tcp_iss &= 0x7fffffff; /* XXX */ 2234 } 2235 2236 return (tcp_iss); 2237 } 2238 2239 #if defined(IPSEC) || defined(FAST_IPSEC) 2240 /* compute ESP/AH header size for TCP, including outer IP header. */ 2241 size_t 2242 ipsec4_hdrsiz_tcp(struct tcpcb *tp) 2243 { 2244 struct inpcb *inp; 2245 size_t hdrsiz; 2246 2247 /* XXX mapped addr case (tp->t_in6pcb) */ 2248 if (!tp || !tp->t_template || !(inp = tp->t_inpcb)) 2249 return 0; 2250 switch (tp->t_family) { 2251 case AF_INET: 2252 /* XXX: should use currect direction. */ 2253 hdrsiz = ipsec4_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, inp); 2254 break; 2255 default: 2256 hdrsiz = 0; 2257 break; 2258 } 2259 2260 return hdrsiz; 2261 } 2262 2263 #ifdef INET6 2264 size_t 2265 ipsec6_hdrsiz_tcp(struct tcpcb *tp) 2266 { 2267 struct in6pcb *in6p; 2268 size_t hdrsiz; 2269 2270 if (!tp || !tp->t_template || !(in6p = tp->t_in6pcb)) 2271 return 0; 2272 switch (tp->t_family) { 2273 case AF_INET6: 2274 /* XXX: should use currect direction. */ 2275 hdrsiz = ipsec6_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, in6p); 2276 break; 2277 case AF_INET: 2278 /* mapped address case - tricky */ 2279 default: 2280 hdrsiz = 0; 2281 break; 2282 } 2283 2284 return hdrsiz; 2285 } 2286 #endif 2287 #endif /*IPSEC*/ 2288 2289 /* 2290 * Determine the length of the TCP options for this connection. 2291 * 2292 * XXX: What do we do for SACK, when we add that? Just reserve 2293 * all of the space? Otherwise we can't exactly be incrementing 2294 * cwnd by an amount that varies depending on the amount we last 2295 * had to SACK! 2296 */ 2297 2298 u_int 2299 tcp_optlen(struct tcpcb *tp) 2300 { 2301 u_int optlen; 2302 2303 optlen = 0; 2304 if ((tp->t_flags & (TF_REQ_TSTMP|TF_RCVD_TSTMP|TF_NOOPT)) == 2305 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 2306 optlen += TCPOLEN_TSTAMP_APPA; 2307 2308 #ifdef TCP_SIGNATURE 2309 if (tp->t_flags & TF_SIGNATURE) 2310 optlen += TCPOLEN_SIGNATURE + 2; 2311 #endif /* TCP_SIGNATURE */ 2312 2313 return optlen; 2314 } 2315 2316 u_int 2317 tcp_hdrsz(struct tcpcb *tp) 2318 { 2319 u_int hlen; 2320 2321 switch (tp->t_family) { 2322 #ifdef INET6 2323 case AF_INET6: 2324 hlen = sizeof(struct ip6_hdr); 2325 break; 2326 #endif 2327 case AF_INET: 2328 hlen = sizeof(struct ip); 2329 break; 2330 default: 2331 hlen = 0; 2332 break; 2333 } 2334 hlen += sizeof(struct tcphdr); 2335 2336 if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP && 2337 (tp->t_flags & TF_RCVD_TSTMP) == TF_RCVD_TSTMP) 2338 hlen += TCPOLEN_TSTAMP_APPA; 2339 #ifdef TCP_SIGNATURE 2340 if (tp->t_flags & TF_SIGNATURE) 2341 hlen += TCPOLEN_SIGLEN; 2342 #endif 2343 return hlen; 2344 } 2345 2346 void 2347 tcp_statinc(u_int stat) 2348 { 2349 2350 KASSERT(stat < TCP_NSTATS); 2351 TCP_STATINC(stat); 2352 } 2353 2354 void 2355 tcp_statadd(u_int stat, uint64_t val) 2356 { 2357 2358 KASSERT(stat < TCP_NSTATS); 2359 TCP_STATADD(stat, val); 2360 } 2361
Indexes created Sun Sep 21 20:09:37 GMT 2025