tcp_subr.c revision 1.155
1 /* $NetBSD: tcp_subr.c,v 1.155 2003/10/21 21:17:20 thorpej 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 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 1.155 2003/10/21 21:17:20 thorpej 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/tcpip.h> 155 156 #ifdef IPSEC 157 #include <netinet6/ipsec.h> 158 #endif /*IPSEC*/ 159 160 #ifdef FAST_IPSEC 161 #include <netipsec/ipsec.h> 162 #ifdef INET6 163 #include <netipsec/ipsec6.h> 164 #endif 165 #endif /* FAST_IPSEC*/ 166 167 168 struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 169 struct tcpstat tcpstat; /* tcp statistics */ 170 u_int32_t tcp_now; /* for RFC 1323 timestamps */ 171 172 /* patchable/settable parameters for tcp */ 173 int tcp_mssdflt = TCP_MSS; 174 int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 175 int tcp_do_rfc1323 = 1; /* window scaling / timestamps (obsolete) */ 176 #if NRND > 0 177 int tcp_do_rfc1948 = 0; /* ISS by cryptographic hash */ 178 #endif 179 int tcp_do_sack = 1; /* selective acknowledgement */ 180 int tcp_do_win_scale = 1; /* RFC1323 window scaling */ 181 int tcp_do_timestamps = 1; /* RFC1323 timestamps */ 182 int tcp_do_newreno = 0; /* Use the New Reno algorithms */ 183 int tcp_ack_on_push = 0; /* set to enable immediate ACK-on-PUSH */ 184 #ifndef TCP_INIT_WIN 185 #define TCP_INIT_WIN 1 /* initial slow start window */ 186 #endif 187 #ifndef TCP_INIT_WIN_LOCAL 188 #define TCP_INIT_WIN_LOCAL 4 /* initial slow start window for local nets */ 189 #endif 190 int tcp_init_win = TCP_INIT_WIN; 191 int tcp_init_win_local = TCP_INIT_WIN_LOCAL; 192 int tcp_mss_ifmtu = 0; 193 #ifdef TCP_COMPAT_42 194 int tcp_compat_42 = 1; 195 #else 196 int tcp_compat_42 = 0; 197 #endif 198 int tcp_rst_ppslim = 100; /* 100pps */ 199 200 /* tcb hash */ 201 #ifndef TCBHASHSIZE 202 #define TCBHASHSIZE 128 203 #endif 204 int tcbhashsize = TCBHASHSIZE; 205 206 /* syn hash parameters */ 207 #define TCP_SYN_HASH_SIZE 293 208 #define TCP_SYN_BUCKET_SIZE 35 209 int tcp_syn_cache_size = TCP_SYN_HASH_SIZE; 210 int tcp_syn_cache_limit = TCP_SYN_HASH_SIZE*TCP_SYN_BUCKET_SIZE; 211 int tcp_syn_bucket_limit = 3*TCP_SYN_BUCKET_SIZE; 212 struct syn_cache_head tcp_syn_cache[TCP_SYN_HASH_SIZE]; 213 214 int tcp_freeq __P((struct tcpcb *)); 215 216 #ifdef INET 217 void tcp_mtudisc_callback __P((struct in_addr)); 218 #endif 219 #ifdef INET6 220 void tcp6_mtudisc_callback __P((struct in6_addr *)); 221 #endif 222 223 void tcp_mtudisc __P((struct inpcb *, int)); 224 #ifdef INET6 225 void tcp6_mtudisc __P((struct in6pcb *, int)); 226 #endif 227 228 struct pool tcpcb_pool; 229 230 #ifdef TCP_CSUM_COUNTERS 231 #include <sys/device.h> 232 233 struct evcnt tcp_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 234 NULL, "tcp", "hwcsum bad"); 235 struct evcnt tcp_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 236 NULL, "tcp", "hwcsum ok"); 237 struct evcnt tcp_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 238 NULL, "tcp", "hwcsum data"); 239 struct evcnt tcp_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 240 NULL, "tcp", "swcsum"); 241 #endif /* TCP_CSUM_COUNTERS */ 242 243 #ifdef TCP_OUTPUT_COUNTERS 244 #include <sys/device.h> 245 246 struct evcnt tcp_output_bigheader = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 247 NULL, "tcp", "output big header"); 248 struct evcnt tcp_output_predict_hit = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 249 NULL, "tcp", "output predict hit"); 250 struct evcnt tcp_output_predict_miss = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 251 NULL, "tcp", "output predict miss"); 252 struct evcnt tcp_output_copysmall = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 253 NULL, "tcp", "output copy small"); 254 struct evcnt tcp_output_copybig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 255 NULL, "tcp", "output copy big"); 256 struct evcnt tcp_output_refbig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 257 NULL, "tcp", "output reference big"); 258 #endif /* TCP_OUTPUT_COUNTERS */ 259 260 #ifdef TCP_REASS_COUNTERS 261 #include <sys/device.h> 262 263 struct evcnt tcp_reass_ = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 264 NULL, "tcp_reass", "calls"); 265 struct evcnt tcp_reass_empty = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 266 &tcp_reass_, "tcp_reass", "insert into empty queue"); 267 struct evcnt tcp_reass_iteration[8] = { 268 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", ">7 iterations"), 269 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "1 iteration"), 270 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "2 iterations"), 271 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "3 iterations"), 272 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "4 iterations"), 273 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "5 iterations"), 274 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "6 iterations"), 275 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "7 iterations"), 276 }; 277 struct evcnt tcp_reass_prependfirst = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 278 &tcp_reass_, "tcp_reass", "prepend to first"); 279 struct evcnt tcp_reass_prepend = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 280 &tcp_reass_, "tcp_reass", "prepend"); 281 struct evcnt tcp_reass_insert = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 282 &tcp_reass_, "tcp_reass", "insert"); 283 struct evcnt tcp_reass_inserttail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 284 &tcp_reass_, "tcp_reass", "insert at tail"); 285 struct evcnt tcp_reass_append = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 286 &tcp_reass_, "tcp_reass", "append"); 287 struct evcnt tcp_reass_appendtail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 288 &tcp_reass_, "tcp_reass", "append to tail fragment"); 289 struct evcnt tcp_reass_overlaptail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 290 &tcp_reass_, "tcp_reass", "overlap at end"); 291 struct evcnt tcp_reass_overlapfront = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 292 &tcp_reass_, "tcp_reass", "overlap at start"); 293 struct evcnt tcp_reass_segdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 294 &tcp_reass_, "tcp_reass", "duplicate segment"); 295 struct evcnt tcp_reass_fragdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 296 &tcp_reass_, "tcp_reass", "duplicate fragment"); 297 298 #endif /* TCP_REASS_COUNTERS */ 299 300 #ifdef MBUFTRACE 301 struct mowner tcp_mowner = { "tcp" }; 302 struct mowner tcp_rx_mowner = { "tcp", "rx" }; 303 struct mowner tcp_tx_mowner = { "tcp", "tx" }; 304 #endif 305 306 /* 307 * Tcp initialization 308 */ 309 void 310 tcp_init() 311 { 312 int hlen; 313 314 pool_init(&tcpcb_pool, sizeof(struct tcpcb), 0, 0, 0, "tcpcbpl", 315 NULL); 316 in_pcbinit(&tcbtable, tcbhashsize, tcbhashsize); 317 318 hlen = sizeof(struct ip) + sizeof(struct tcphdr); 319 #ifdef INET6 320 if (sizeof(struct ip) < sizeof(struct ip6_hdr)) 321 hlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 322 #endif 323 if (max_protohdr < hlen) 324 max_protohdr = hlen; 325 if (max_linkhdr + hlen > MHLEN) 326 panic("tcp_init"); 327 328 #ifdef INET 329 icmp_mtudisc_callback_register(tcp_mtudisc_callback); 330 #endif 331 #ifdef INET6 332 icmp6_mtudisc_callback_register(tcp6_mtudisc_callback); 333 #endif 334 335 /* Initialize timer state. */ 336 tcp_timer_init(); 337 338 /* Initialize the compressed state engine. */ 339 syn_cache_init(); 340 341 #ifdef TCP_CSUM_COUNTERS 342 evcnt_attach_static(&tcp_hwcsum_bad); 343 evcnt_attach_static(&tcp_hwcsum_ok); 344 evcnt_attach_static(&tcp_hwcsum_data); 345 evcnt_attach_static(&tcp_swcsum); 346 #endif /* TCP_CSUM_COUNTERS */ 347 348 #ifdef TCP_OUTPUT_COUNTERS 349 evcnt_attach_static(&tcp_output_bigheader); 350 evcnt_attach_static(&tcp_output_predict_hit); 351 evcnt_attach_static(&tcp_output_predict_miss); 352 evcnt_attach_static(&tcp_output_copysmall); 353 evcnt_attach_static(&tcp_output_copybig); 354 evcnt_attach_static(&tcp_output_refbig); 355 #endif /* TCP_OUTPUT_COUNTERS */ 356 357 #ifdef TCP_REASS_COUNTERS 358 evcnt_attach_static(&tcp_reass_); 359 evcnt_attach_static(&tcp_reass_empty); 360 evcnt_attach_static(&tcp_reass_iteration[0]); 361 evcnt_attach_static(&tcp_reass_iteration[1]); 362 evcnt_attach_static(&tcp_reass_iteration[2]); 363 evcnt_attach_static(&tcp_reass_iteration[3]); 364 evcnt_attach_static(&tcp_reass_iteration[4]); 365 evcnt_attach_static(&tcp_reass_iteration[5]); 366 evcnt_attach_static(&tcp_reass_iteration[6]); 367 evcnt_attach_static(&tcp_reass_iteration[7]); 368 evcnt_attach_static(&tcp_reass_prependfirst); 369 evcnt_attach_static(&tcp_reass_prepend); 370 evcnt_attach_static(&tcp_reass_insert); 371 evcnt_attach_static(&tcp_reass_inserttail); 372 evcnt_attach_static(&tcp_reass_append); 373 evcnt_attach_static(&tcp_reass_appendtail); 374 evcnt_attach_static(&tcp_reass_overlaptail); 375 evcnt_attach_static(&tcp_reass_overlapfront); 376 evcnt_attach_static(&tcp_reass_segdup); 377 evcnt_attach_static(&tcp_reass_fragdup); 378 #endif /* TCP_REASS_COUNTERS */ 379 380 MOWNER_ATTACH(&tcp_tx_mowner); 381 MOWNER_ATTACH(&tcp_rx_mowner); 382 MOWNER_ATTACH(&tcp_mowner); 383 } 384 385 /* 386 * Create template to be used to send tcp packets on a connection. 387 * Call after host entry created, allocates an mbuf and fills 388 * in a skeletal tcp/ip header, minimizing the amount of work 389 * necessary when the connection is used. 390 */ 391 struct mbuf * 392 tcp_template(tp) 393 struct tcpcb *tp; 394 { 395 struct inpcb *inp = tp->t_inpcb; 396 #ifdef INET6 397 struct in6pcb *in6p = tp->t_in6pcb; 398 #endif 399 struct tcphdr *n; 400 struct mbuf *m; 401 int hlen; 402 403 switch (tp->t_family) { 404 case AF_INET: 405 hlen = sizeof(struct ip); 406 if (inp) 407 break; 408 #ifdef INET6 409 if (in6p) { 410 /* mapped addr case */ 411 if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr) 412 && IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) 413 break; 414 } 415 #endif 416 return NULL; /*EINVAL*/ 417 #ifdef INET6 418 case AF_INET6: 419 hlen = sizeof(struct ip6_hdr); 420 if (in6p) { 421 /* more sainty check? */ 422 break; 423 } 424 return NULL; /*EINVAL*/ 425 #endif 426 default: 427 hlen = 0; /*pacify gcc*/ 428 return NULL; /*EAFNOSUPPORT*/ 429 } 430 #ifdef DIAGNOSTIC 431 if (hlen + sizeof(struct tcphdr) > MCLBYTES) 432 panic("mclbytes too small for t_template"); 433 #endif 434 m = tp->t_template; 435 if (m && m->m_len == hlen + sizeof(struct tcphdr)) 436 ; 437 else { 438 if (m) 439 m_freem(m); 440 m = tp->t_template = NULL; 441 MGETHDR(m, M_DONTWAIT, MT_HEADER); 442 if (m && hlen + sizeof(struct tcphdr) > MHLEN) { 443 MCLGET(m, M_DONTWAIT); 444 if ((m->m_flags & M_EXT) == 0) { 445 m_free(m); 446 m = NULL; 447 } 448 } 449 if (m == NULL) 450 return NULL; 451 MCLAIM(m, &tcp_mowner); 452 m->m_pkthdr.len = m->m_len = hlen + sizeof(struct tcphdr); 453 } 454 455 bzero(mtod(m, caddr_t), m->m_len); 456 457 n = (struct tcphdr *)(mtod(m, caddr_t) + hlen); 458 459 switch (tp->t_family) { 460 case AF_INET: 461 { 462 struct ipovly *ipov; 463 mtod(m, struct ip *)->ip_v = 4; 464 mtod(m, struct ip *)->ip_hl = hlen >> 2; 465 ipov = mtod(m, struct ipovly *); 466 ipov->ih_pr = IPPROTO_TCP; 467 ipov->ih_len = htons(sizeof(struct tcphdr)); 468 if (inp) { 469 ipov->ih_src = inp->inp_laddr; 470 ipov->ih_dst = inp->inp_faddr; 471 } 472 #ifdef INET6 473 else if (in6p) { 474 /* mapped addr case */ 475 bcopy(&in6p->in6p_laddr.s6_addr32[3], &ipov->ih_src, 476 sizeof(ipov->ih_src)); 477 bcopy(&in6p->in6p_faddr.s6_addr32[3], &ipov->ih_dst, 478 sizeof(ipov->ih_dst)); 479 } 480 #endif 481 /* 482 * Compute the pseudo-header portion of the checksum 483 * now. We incrementally add in the TCP option and 484 * payload lengths later, and then compute the TCP 485 * checksum right before the packet is sent off onto 486 * the wire. 487 */ 488 n->th_sum = in_cksum_phdr(ipov->ih_src.s_addr, 489 ipov->ih_dst.s_addr, 490 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 491 break; 492 } 493 #ifdef INET6 494 case AF_INET6: 495 { 496 struct ip6_hdr *ip6; 497 mtod(m, struct ip *)->ip_v = 6; 498 ip6 = mtod(m, struct ip6_hdr *); 499 ip6->ip6_nxt = IPPROTO_TCP; 500 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 501 ip6->ip6_src = in6p->in6p_laddr; 502 ip6->ip6_dst = in6p->in6p_faddr; 503 ip6->ip6_flow = in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK; 504 if (ip6_auto_flowlabel) { 505 ip6->ip6_flow &= ~IPV6_FLOWLABEL_MASK; 506 ip6->ip6_flow |= 507 (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK); 508 } 509 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 510 ip6->ip6_vfc |= IPV6_VERSION; 511 512 /* 513 * Compute the pseudo-header portion of the checksum 514 * now. We incrementally add in the TCP option and 515 * payload lengths later, and then compute the TCP 516 * checksum right before the packet is sent off onto 517 * the wire. 518 */ 519 n->th_sum = in6_cksum_phdr(&in6p->in6p_laddr, 520 &in6p->in6p_faddr, htonl(sizeof(struct tcphdr)), 521 htonl(IPPROTO_TCP)); 522 break; 523 } 524 #endif 525 } 526 if (inp) { 527 n->th_sport = inp->inp_lport; 528 n->th_dport = inp->inp_fport; 529 } 530 #ifdef INET6 531 else if (in6p) { 532 n->th_sport = in6p->in6p_lport; 533 n->th_dport = in6p->in6p_fport; 534 } 535 #endif 536 n->th_seq = 0; 537 n->th_ack = 0; 538 n->th_x2 = 0; 539 n->th_off = 5; 540 n->th_flags = 0; 541 n->th_win = 0; 542 n->th_urp = 0; 543 return (m); 544 } 545 546 /* 547 * Send a single message to the TCP at address specified by 548 * the given TCP/IP header. If m == 0, then we make a copy 549 * of the tcpiphdr at ti and send directly to the addressed host. 550 * This is used to force keep alive messages out using the TCP 551 * template for a connection tp->t_template. If flags are given 552 * then we send a message back to the TCP which originated the 553 * segment ti, and discard the mbuf containing it and any other 554 * attached mbufs. 555 * 556 * In any case the ack and sequence number of the transmitted 557 * segment are as specified by the parameters. 558 */ 559 int 560 tcp_respond(tp, template, m, th0, ack, seq, flags) 561 struct tcpcb *tp; 562 struct mbuf *template; 563 struct mbuf *m; 564 struct tcphdr *th0; 565 tcp_seq ack, seq; 566 int flags; 567 { 568 struct route *ro; 569 int error, tlen, win = 0; 570 int hlen; 571 struct ip *ip; 572 #ifdef INET6 573 struct ip6_hdr *ip6; 574 #endif 575 int family; /* family on packet, not inpcb/in6pcb! */ 576 struct tcphdr *th; 577 struct socket *so; 578 579 if (tp != NULL && (flags & TH_RST) == 0) { 580 #ifdef DIAGNOSTIC 581 if (tp->t_inpcb && tp->t_in6pcb) 582 panic("tcp_respond: both t_inpcb and t_in6pcb are set"); 583 #endif 584 #ifdef INET 585 if (tp->t_inpcb) 586 win = sbspace(&tp->t_inpcb->inp_socket->so_rcv); 587 #endif 588 #ifdef INET6 589 if (tp->t_in6pcb) 590 win = sbspace(&tp->t_in6pcb->in6p_socket->so_rcv); 591 #endif 592 } 593 594 th = NULL; /* Quell uninitialized warning */ 595 ip = NULL; 596 #ifdef INET6 597 ip6 = NULL; 598 #endif 599 if (m == 0) { 600 if (!template) 601 return EINVAL; 602 603 /* get family information from template */ 604 switch (mtod(template, struct ip *)->ip_v) { 605 case 4: 606 family = AF_INET; 607 hlen = sizeof(struct ip); 608 break; 609 #ifdef INET6 610 case 6: 611 family = AF_INET6; 612 hlen = sizeof(struct ip6_hdr); 613 break; 614 #endif 615 default: 616 return EAFNOSUPPORT; 617 } 618 619 MGETHDR(m, M_DONTWAIT, MT_HEADER); 620 if (m) { 621 MCLAIM(m, &tcp_tx_mowner); 622 MCLGET(m, M_DONTWAIT); 623 if ((m->m_flags & M_EXT) == 0) { 624 m_free(m); 625 m = NULL; 626 } 627 } 628 if (m == NULL) 629 return (ENOBUFS); 630 631 if (tcp_compat_42) 632 tlen = 1; 633 else 634 tlen = 0; 635 636 m->m_data += max_linkhdr; 637 bcopy(mtod(template, caddr_t), mtod(m, caddr_t), 638 template->m_len); 639 switch (family) { 640 case AF_INET: 641 ip = mtod(m, struct ip *); 642 th = (struct tcphdr *)(ip + 1); 643 break; 644 #ifdef INET6 645 case AF_INET6: 646 ip6 = mtod(m, struct ip6_hdr *); 647 th = (struct tcphdr *)(ip6 + 1); 648 break; 649 #endif 650 #if 0 651 default: 652 /* noone will visit here */ 653 m_freem(m); 654 return EAFNOSUPPORT; 655 #endif 656 } 657 flags = TH_ACK; 658 } else { 659 660 if ((m->m_flags & M_PKTHDR) == 0) { 661 #if 0 662 printf("non PKTHDR to tcp_respond\n"); 663 #endif 664 m_freem(m); 665 return EINVAL; 666 } 667 #ifdef DIAGNOSTIC 668 if (!th0) 669 panic("th0 == NULL in tcp_respond"); 670 #endif 671 672 /* get family information from m */ 673 switch (mtod(m, struct ip *)->ip_v) { 674 case 4: 675 family = AF_INET; 676 hlen = sizeof(struct ip); 677 ip = mtod(m, struct ip *); 678 break; 679 #ifdef INET6 680 case 6: 681 family = AF_INET6; 682 hlen = sizeof(struct ip6_hdr); 683 ip6 = mtod(m, struct ip6_hdr *); 684 break; 685 #endif 686 default: 687 m_freem(m); 688 return EAFNOSUPPORT; 689 } 690 if ((flags & TH_SYN) == 0 || sizeof(*th0) > (th0->th_off << 2)) 691 tlen = sizeof(*th0); 692 else 693 tlen = th0->th_off << 2; 694 695 if (m->m_len > hlen + tlen && (m->m_flags & M_EXT) == 0 && 696 mtod(m, caddr_t) + hlen == (caddr_t)th0) { 697 m->m_len = hlen + tlen; 698 m_freem(m->m_next); 699 m->m_next = NULL; 700 } else { 701 struct mbuf *n; 702 703 #ifdef DIAGNOSTIC 704 if (max_linkhdr + hlen + tlen > MCLBYTES) { 705 m_freem(m); 706 return EMSGSIZE; 707 } 708 #endif 709 MGETHDR(n, M_DONTWAIT, MT_HEADER); 710 if (n && max_linkhdr + hlen + tlen > MHLEN) { 711 MCLGET(n, M_DONTWAIT); 712 if ((n->m_flags & M_EXT) == 0) { 713 m_freem(n); 714 n = NULL; 715 } 716 } 717 if (!n) { 718 m_freem(m); 719 return ENOBUFS; 720 } 721 722 MCLAIM(n, &tcp_tx_mowner); 723 n->m_data += max_linkhdr; 724 n->m_len = hlen + tlen; 725 m_copyback(n, 0, hlen, mtod(m, caddr_t)); 726 m_copyback(n, hlen, tlen, (caddr_t)th0); 727 728 m_freem(m); 729 m = n; 730 n = NULL; 731 } 732 733 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 734 switch (family) { 735 case AF_INET: 736 ip = mtod(m, struct ip *); 737 th = (struct tcphdr *)(ip + 1); 738 ip->ip_p = IPPROTO_TCP; 739 xchg(ip->ip_dst, ip->ip_src, struct in_addr); 740 ip->ip_p = IPPROTO_TCP; 741 break; 742 #ifdef INET6 743 case AF_INET6: 744 ip6 = mtod(m, struct ip6_hdr *); 745 th = (struct tcphdr *)(ip6 + 1); 746 ip6->ip6_nxt = IPPROTO_TCP; 747 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 748 ip6->ip6_nxt = IPPROTO_TCP; 749 break; 750 #endif 751 #if 0 752 default: 753 /* noone will visit here */ 754 m_freem(m); 755 return EAFNOSUPPORT; 756 #endif 757 } 758 xchg(th->th_dport, th->th_sport, u_int16_t); 759 #undef xchg 760 tlen = 0; /*be friendly with the following code*/ 761 } 762 th->th_seq = htonl(seq); 763 th->th_ack = htonl(ack); 764 th->th_x2 = 0; 765 if ((flags & TH_SYN) == 0) { 766 if (tp) 767 win >>= tp->rcv_scale; 768 if (win > TCP_MAXWIN) 769 win = TCP_MAXWIN; 770 th->th_win = htons((u_int16_t)win); 771 th->th_off = sizeof (struct tcphdr) >> 2; 772 tlen += sizeof(*th); 773 } else 774 tlen += th->th_off << 2; 775 m->m_len = hlen + tlen; 776 m->m_pkthdr.len = hlen + tlen; 777 m->m_pkthdr.rcvif = (struct ifnet *) 0; 778 th->th_flags = flags; 779 th->th_urp = 0; 780 781 switch (family) { 782 #ifdef INET 783 case AF_INET: 784 { 785 struct ipovly *ipov = (struct ipovly *)ip; 786 bzero(ipov->ih_x1, sizeof ipov->ih_x1); 787 ipov->ih_len = htons((u_int16_t)tlen); 788 789 th->th_sum = 0; 790 th->th_sum = in_cksum(m, hlen + tlen); 791 ip->ip_len = htons(hlen + tlen); 792 ip->ip_ttl = ip_defttl; 793 break; 794 } 795 #endif 796 #ifdef INET6 797 case AF_INET6: 798 { 799 th->th_sum = 0; 800 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr), 801 tlen); 802 ip6->ip6_plen = ntohs(tlen); 803 if (tp && tp->t_in6pcb) { 804 struct ifnet *oifp; 805 ro = (struct route *)&tp->t_in6pcb->in6p_route; 806 oifp = ro->ro_rt ? ro->ro_rt->rt_ifp : NULL; 807 ip6->ip6_hlim = in6_selecthlim(tp->t_in6pcb, oifp); 808 } else 809 ip6->ip6_hlim = ip6_defhlim; 810 ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK; 811 if (ip6_auto_flowlabel) { 812 ip6->ip6_flow |= 813 (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK); 814 } 815 break; 816 } 817 #endif 818 } 819 820 if (tp && tp->t_inpcb) 821 so = tp->t_inpcb->inp_socket; 822 #ifdef INET6 823 else if (tp && tp->t_in6pcb) 824 so = tp->t_in6pcb->in6p_socket; 825 #endif 826 else 827 so = NULL; 828 829 if (tp != NULL && tp->t_inpcb != NULL) { 830 ro = &tp->t_inpcb->inp_route; 831 #ifdef DIAGNOSTIC 832 if (family != AF_INET) 833 panic("tcp_respond: address family mismatch"); 834 if (!in_hosteq(ip->ip_dst, tp->t_inpcb->inp_faddr)) { 835 panic("tcp_respond: ip_dst %x != inp_faddr %x", 836 ntohl(ip->ip_dst.s_addr), 837 ntohl(tp->t_inpcb->inp_faddr.s_addr)); 838 } 839 #endif 840 } 841 #ifdef INET6 842 else if (tp != NULL && tp->t_in6pcb != NULL) { 843 ro = (struct route *)&tp->t_in6pcb->in6p_route; 844 #ifdef DIAGNOSTIC 845 if (family == AF_INET) { 846 if (!IN6_IS_ADDR_V4MAPPED(&tp->t_in6pcb->in6p_faddr)) 847 panic("tcp_respond: not mapped addr"); 848 if (bcmp(&ip->ip_dst, 849 &tp->t_in6pcb->in6p_faddr.s6_addr32[3], 850 sizeof(ip->ip_dst)) != 0) { 851 panic("tcp_respond: ip_dst != in6p_faddr"); 852 } 853 } else if (family == AF_INET6) { 854 if (!IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 855 &tp->t_in6pcb->in6p_faddr)) 856 panic("tcp_respond: ip6_dst != in6p_faddr"); 857 } else 858 panic("tcp_respond: address family mismatch"); 859 #endif 860 } 861 #endif 862 else 863 ro = NULL; 864 865 switch (family) { 866 #ifdef INET 867 case AF_INET: 868 error = ip_output(m, NULL, ro, 869 (tp && tp->t_mtudisc ? IP_MTUDISC : 0), 870 (struct ip_moptions *)0, so); 871 break; 872 #endif 873 #ifdef INET6 874 case AF_INET6: 875 error = ip6_output(m, NULL, (struct route_in6 *)ro, 0, 876 (struct ip6_moptions *)0, so, NULL); 877 break; 878 #endif 879 default: 880 error = EAFNOSUPPORT; 881 break; 882 } 883 884 return (error); 885 } 886 887 /* 888 * Create a new TCP control block, making an 889 * empty reassembly queue and hooking it to the argument 890 * protocol control block. 891 */ 892 struct tcpcb * 893 tcp_newtcpcb(family, aux) 894 int family; /* selects inpcb, or in6pcb */ 895 void *aux; 896 { 897 struct tcpcb *tp; 898 int i; 899 900 switch (family) { 901 case PF_INET: 902 break; 903 #ifdef INET6 904 case PF_INET6: 905 break; 906 #endif 907 default: 908 return NULL; 909 } 910 911 tp = pool_get(&tcpcb_pool, PR_NOWAIT); 912 if (tp == NULL) 913 return (NULL); 914 bzero((caddr_t)tp, sizeof(struct tcpcb)); 915 TAILQ_INIT(&tp->segq); 916 TAILQ_INIT(&tp->timeq); 917 tp->t_family = family; /* may be overridden later on */ 918 tp->t_peermss = tcp_mssdflt; 919 tp->t_ourmss = tcp_mssdflt; 920 tp->t_segsz = tcp_mssdflt; 921 LIST_INIT(&tp->t_sc); 922 923 tp->t_lastm = NULL; 924 tp->t_lastoff = 0; 925 926 callout_init(&tp->t_delack_ch); 927 for (i = 0; i < TCPT_NTIMERS; i++) 928 TCP_TIMER_INIT(tp, i); 929 930 tp->t_flags = 0; 931 if (tcp_do_rfc1323 && tcp_do_win_scale) 932 tp->t_flags |= TF_REQ_SCALE; 933 if (tcp_do_rfc1323 && tcp_do_timestamps) 934 tp->t_flags |= TF_REQ_TSTMP; 935 if (tcp_do_sack == 2) 936 tp->t_flags |= TF_WILL_SACK; 937 else if (tcp_do_sack == 1) 938 tp->t_flags |= TF_WILL_SACK|TF_IGNR_RXSACK; 939 tp->t_flags |= TF_CANT_TXSACK; 940 switch (family) { 941 case PF_INET: 942 tp->t_inpcb = (struct inpcb *)aux; 943 tp->t_mtudisc = ip_mtudisc; 944 break; 945 #ifdef INET6 946 case PF_INET6: 947 tp->t_in6pcb = (struct in6pcb *)aux; 948 /* for IPv6, always try to run path MTU discovery */ 949 tp->t_mtudisc = 1; 950 break; 951 #endif 952 } 953 /* 954 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 955 * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives 956 * reasonable initial retransmit time. 957 */ 958 tp->t_srtt = TCPTV_SRTTBASE; 959 tp->t_rttvar = tcp_rttdflt * PR_SLOWHZ << (TCP_RTTVAR_SHIFT + 2 - 1); 960 tp->t_rttmin = TCPTV_MIN; 961 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), 962 TCPTV_MIN, TCPTV_REXMTMAX); 963 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 964 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 965 if (family == AF_INET) { 966 struct inpcb *inp = (struct inpcb *)aux; 967 inp->inp_ip.ip_ttl = ip_defttl; 968 inp->inp_ppcb = (caddr_t)tp; 969 } 970 #ifdef INET6 971 else if (family == AF_INET6) { 972 struct in6pcb *in6p = (struct in6pcb *)aux; 973 in6p->in6p_ip6.ip6_hlim = in6_selecthlim(in6p, 974 in6p->in6p_route.ro_rt ? in6p->in6p_route.ro_rt->rt_ifp 975 : NULL); 976 in6p->in6p_ppcb = (caddr_t)tp; 977 } 978 #endif 979 980 /* 981 * Initialize our timebase. When we send timestamps, we take 982 * the delta from tcp_now -- this means each connection always 983 * gets a timebase of 0, which makes it, among other things, 984 * more difficult to determine how long a system has been up, 985 * and thus how many TCP sequence increments have occurred. 986 */ 987 tp->ts_timebase = tcp_now; 988 989 return (tp); 990 } 991 992 /* 993 * Drop a TCP connection, reporting 994 * the specified error. If connection is synchronized, 995 * then send a RST to peer. 996 */ 997 struct tcpcb * 998 tcp_drop(tp, errno) 999 struct tcpcb *tp; 1000 int errno; 1001 { 1002 struct socket *so = NULL; 1003 1004 #ifdef DIAGNOSTIC 1005 if (tp->t_inpcb && tp->t_in6pcb) 1006 panic("tcp_drop: both t_inpcb and t_in6pcb are set"); 1007 #endif 1008 #ifdef INET 1009 if (tp->t_inpcb) 1010 so = tp->t_inpcb->inp_socket; 1011 #endif 1012 #ifdef INET6 1013 if (tp->t_in6pcb) 1014 so = tp->t_in6pcb->in6p_socket; 1015 #endif 1016 if (!so) 1017 return NULL; 1018 1019 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1020 tp->t_state = TCPS_CLOSED; 1021 (void) tcp_output(tp); 1022 tcpstat.tcps_drops++; 1023 } else 1024 tcpstat.tcps_conndrops++; 1025 if (errno == ETIMEDOUT && tp->t_softerror) 1026 errno = tp->t_softerror; 1027 so->so_error = errno; 1028 return (tcp_close(tp)); 1029 } 1030 1031 /* 1032 * Return whether this tcpcb is marked as dead, indicating 1033 * to the calling timer function that no further action should 1034 * be taken, as we are about to release this tcpcb. The release 1035 * of the storage will be done if this is the last timer running. 1036 * 1037 * This is typically called from the callout handler function before 1038 * callout_ack() is done, therefore we need to test the number of 1039 * running timer functions against 1 below, not 0. 1040 */ 1041 int 1042 tcp_isdead(tp) 1043 struct tcpcb *tp; 1044 { 1045 int dead = (tp->t_flags & TF_DEAD); 1046 1047 if (__predict_false(dead)) { 1048 if (tcp_timers_invoking(tp) > 1) 1049 /* not quite there yet -- count separately? */ 1050 return dead; 1051 tcpstat.tcps_delayed_free++; 1052 pool_put(&tcpcb_pool, tp); 1053 } 1054 return dead; 1055 } 1056 1057 /* 1058 * Close a TCP control block: 1059 * discard all space held by the tcp 1060 * discard internet protocol block 1061 * wake up any sleepers 1062 */ 1063 struct tcpcb * 1064 tcp_close(tp) 1065 struct tcpcb *tp; 1066 { 1067 struct inpcb *inp; 1068 #ifdef INET6 1069 struct in6pcb *in6p; 1070 #endif 1071 struct socket *so; 1072 #ifdef RTV_RTT 1073 struct rtentry *rt; 1074 #endif 1075 struct route *ro; 1076 1077 inp = tp->t_inpcb; 1078 #ifdef INET6 1079 in6p = tp->t_in6pcb; 1080 #endif 1081 so = NULL; 1082 ro = NULL; 1083 if (inp) { 1084 so = inp->inp_socket; 1085 ro = &inp->inp_route; 1086 } 1087 #ifdef INET6 1088 else if (in6p) { 1089 so = in6p->in6p_socket; 1090 ro = (struct route *)&in6p->in6p_route; 1091 } 1092 #endif 1093 1094 #ifdef RTV_RTT 1095 /* 1096 * If we sent enough data to get some meaningful characteristics, 1097 * save them in the routing entry. 'Enough' is arbitrarily 1098 * defined as the sendpipesize (default 4K) * 16. This would 1099 * give us 16 rtt samples assuming we only get one sample per 1100 * window (the usual case on a long haul net). 16 samples is 1101 * enough for the srtt filter to converge to within 5% of the correct 1102 * value; fewer samples and we could save a very bogus rtt. 1103 * 1104 * Don't update the default route's characteristics and don't 1105 * update anything that the user "locked". 1106 */ 1107 if (SEQ_LT(tp->iss + so->so_snd.sb_hiwat * 16, tp->snd_max) && 1108 ro && (rt = ro->ro_rt) && 1109 !in_nullhost(satosin(rt_key(rt))->sin_addr)) { 1110 u_long i = 0; 1111 1112 if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) { 1113 i = tp->t_srtt * 1114 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 1115 if (rt->rt_rmx.rmx_rtt && i) 1116 /* 1117 * filter this update to half the old & half 1118 * the new values, converting scale. 1119 * See route.h and tcp_var.h for a 1120 * description of the scaling constants. 1121 */ 1122 rt->rt_rmx.rmx_rtt = 1123 (rt->rt_rmx.rmx_rtt + i) / 2; 1124 else 1125 rt->rt_rmx.rmx_rtt = i; 1126 } 1127 if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) { 1128 i = tp->t_rttvar * 1129 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTTVAR_SHIFT + 2)); 1130 if (rt->rt_rmx.rmx_rttvar && i) 1131 rt->rt_rmx.rmx_rttvar = 1132 (rt->rt_rmx.rmx_rttvar + i) / 2; 1133 else 1134 rt->rt_rmx.rmx_rttvar = i; 1135 } 1136 /* 1137 * update the pipelimit (ssthresh) if it has been updated 1138 * already or if a pipesize was specified & the threshhold 1139 * got below half the pipesize. I.e., wait for bad news 1140 * before we start updating, then update on both good 1141 * and bad news. 1142 */ 1143 if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 && 1144 (i = tp->snd_ssthresh) && rt->rt_rmx.rmx_ssthresh) || 1145 i < (rt->rt_rmx.rmx_sendpipe / 2)) { 1146 /* 1147 * convert the limit from user data bytes to 1148 * packets then to packet data bytes. 1149 */ 1150 i = (i + tp->t_segsz / 2) / tp->t_segsz; 1151 if (i < 2) 1152 i = 2; 1153 i *= (u_long)(tp->t_segsz + sizeof (struct tcpiphdr)); 1154 if (rt->rt_rmx.rmx_ssthresh) 1155 rt->rt_rmx.rmx_ssthresh = 1156 (rt->rt_rmx.rmx_ssthresh + i) / 2; 1157 else 1158 rt->rt_rmx.rmx_ssthresh = i; 1159 } 1160 } 1161 #endif /* RTV_RTT */ 1162 /* free the reassembly queue, if any */ 1163 TCP_REASS_LOCK(tp); 1164 (void) tcp_freeq(tp); 1165 TCP_REASS_UNLOCK(tp); 1166 1167 tcp_canceltimers(tp); 1168 TCP_CLEAR_DELACK(tp); 1169 syn_cache_cleanup(tp); 1170 1171 if (tp->t_template) { 1172 m_free(tp->t_template); 1173 tp->t_template = NULL; 1174 } 1175 if (tcp_timers_invoking(tp)) 1176 tp->t_flags |= TF_DEAD; 1177 else 1178 pool_put(&tcpcb_pool, tp); 1179 1180 if (inp) { 1181 inp->inp_ppcb = 0; 1182 soisdisconnected(so); 1183 in_pcbdetach(inp); 1184 } 1185 #ifdef INET6 1186 else if (in6p) { 1187 in6p->in6p_ppcb = 0; 1188 soisdisconnected(so); 1189 in6_pcbdetach(in6p); 1190 } 1191 #endif 1192 tcpstat.tcps_closed++; 1193 return ((struct tcpcb *)0); 1194 } 1195 1196 int 1197 tcp_freeq(tp) 1198 struct tcpcb *tp; 1199 { 1200 struct ipqent *qe; 1201 int rv = 0; 1202 #ifdef TCPREASS_DEBUG 1203 int i = 0; 1204 #endif 1205 1206 TCP_REASS_LOCK_CHECK(tp); 1207 1208 while ((qe = TAILQ_FIRST(&tp->segq)) != NULL) { 1209 #ifdef TCPREASS_DEBUG 1210 printf("tcp_freeq[%p,%d]: %u:%u(%u) 0x%02x\n", 1211 tp, i++, qe->ipqe_seq, qe->ipqe_seq + qe->ipqe_len, 1212 qe->ipqe_len, qe->ipqe_flags & (TH_SYN|TH_FIN|TH_RST)); 1213 #endif 1214 TAILQ_REMOVE(&tp->segq, qe, ipqe_q); 1215 TAILQ_REMOVE(&tp->timeq, qe, ipqe_timeq); 1216 m_freem(qe->ipqe_m); 1217 pool_put(&ipqent_pool, qe); 1218 rv = 1; 1219 } 1220 return (rv); 1221 } 1222 1223 /* 1224 * Protocol drain routine. Called when memory is in short supply. 1225 */ 1226 void 1227 tcp_drain() 1228 { 1229 struct inpcb_hdr *inph; 1230 struct tcpcb *tp; 1231 1232 /* 1233 * Free the sequence queue of all TCP connections. 1234 */ 1235 CIRCLEQ_FOREACH(inph, &tcbtable.inpt_queue, inph_queue) { 1236 switch (inph->inph_af) { 1237 case AF_INET: 1238 tp = intotcpcb((struct inpcb *)inph); 1239 break; 1240 #ifdef INET6 1241 case AF_INET6: 1242 tp = in6totcpcb((struct in6pcb *)inph); 1243 break; 1244 #endif 1245 default: 1246 tp = NULL; 1247 break; 1248 } 1249 if (tp != NULL) { 1250 /* 1251 * We may be called from a device's interrupt 1252 * context. If the tcpcb is already busy, 1253 * just bail out now. 1254 */ 1255 if (tcp_reass_lock_try(tp) == 0) 1256 continue; 1257 if (tcp_freeq(tp)) 1258 tcpstat.tcps_connsdrained++; 1259 TCP_REASS_UNLOCK(tp); 1260 } 1261 } 1262 } 1263 1264 /* 1265 * Notify a tcp user of an asynchronous error; 1266 * store error as soft error, but wake up user 1267 * (for now, won't do anything until can select for soft error). 1268 */ 1269 void 1270 tcp_notify(inp, error) 1271 struct inpcb *inp; 1272 int error; 1273 { 1274 struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb; 1275 struct socket *so = inp->inp_socket; 1276 1277 /* 1278 * Ignore some errors if we are hooked up. 1279 * If connection hasn't completed, has retransmitted several times, 1280 * and receives a second error, give up now. This is better 1281 * than waiting a long time to establish a connection that 1282 * can never complete. 1283 */ 1284 if (tp->t_state == TCPS_ESTABLISHED && 1285 (error == EHOSTUNREACH || error == ENETUNREACH || 1286 error == EHOSTDOWN)) { 1287 return; 1288 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1289 tp->t_rxtshift > 3 && tp->t_softerror) 1290 so->so_error = error; 1291 else 1292 tp->t_softerror = error; 1293 wakeup((caddr_t) &so->so_timeo); 1294 sorwakeup(so); 1295 sowwakeup(so); 1296 } 1297 1298 #ifdef INET6 1299 void 1300 tcp6_notify(in6p, error) 1301 struct in6pcb *in6p; 1302 int error; 1303 { 1304 struct tcpcb *tp = (struct tcpcb *)in6p->in6p_ppcb; 1305 struct socket *so = in6p->in6p_socket; 1306 1307 /* 1308 * Ignore some errors if we are hooked up. 1309 * If connection hasn't completed, has retransmitted several times, 1310 * and receives a second error, give up now. This is better 1311 * than waiting a long time to establish a connection that 1312 * can never complete. 1313 */ 1314 if (tp->t_state == TCPS_ESTABLISHED && 1315 (error == EHOSTUNREACH || error == ENETUNREACH || 1316 error == EHOSTDOWN)) { 1317 return; 1318 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1319 tp->t_rxtshift > 3 && tp->t_softerror) 1320 so->so_error = error; 1321 else 1322 tp->t_softerror = error; 1323 wakeup((caddr_t) &so->so_timeo); 1324 sorwakeup(so); 1325 sowwakeup(so); 1326 } 1327 #endif 1328 1329 #ifdef INET6 1330 void 1331 tcp6_ctlinput(cmd, sa, d) 1332 int cmd; 1333 struct sockaddr *sa; 1334 void *d; 1335 { 1336 struct tcphdr th; 1337 void (*notify) __P((struct in6pcb *, int)) = tcp6_notify; 1338 int nmatch; 1339 struct ip6_hdr *ip6; 1340 const struct sockaddr_in6 *sa6_src = NULL; 1341 struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)sa; 1342 struct mbuf *m; 1343 int off; 1344 1345 if (sa->sa_family != AF_INET6 || 1346 sa->sa_len != sizeof(struct sockaddr_in6)) 1347 return; 1348 if ((unsigned)cmd >= PRC_NCMDS) 1349 return; 1350 else if (cmd == PRC_QUENCH) { 1351 /* XXX there's no PRC_QUENCH in IPv6 */ 1352 notify = tcp6_quench; 1353 } else if (PRC_IS_REDIRECT(cmd)) 1354 notify = in6_rtchange, d = NULL; 1355 else if (cmd == PRC_MSGSIZE) 1356 ; /* special code is present, see below */ 1357 else if (cmd == PRC_HOSTDEAD) 1358 d = NULL; 1359 else if (inet6ctlerrmap[cmd] == 0) 1360 return; 1361 1362 /* if the parameter is from icmp6, decode it. */ 1363 if (d != NULL) { 1364 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 1365 m = ip6cp->ip6c_m; 1366 ip6 = ip6cp->ip6c_ip6; 1367 off = ip6cp->ip6c_off; 1368 sa6_src = ip6cp->ip6c_src; 1369 } else { 1370 m = NULL; 1371 ip6 = NULL; 1372 sa6_src = &sa6_any; 1373 } 1374 1375 if (ip6) { 1376 /* 1377 * XXX: We assume that when ip6 is non NULL, 1378 * M and OFF are valid. 1379 */ 1380 1381 /* check if we can safely examine src and dst ports */ 1382 if (m->m_pkthdr.len < off + sizeof(th)) { 1383 if (cmd == PRC_MSGSIZE) 1384 icmp6_mtudisc_update((struct ip6ctlparam *)d, 0); 1385 return; 1386 } 1387 1388 bzero(&th, sizeof(th)); 1389 m_copydata(m, off, sizeof(th), (caddr_t)&th); 1390 1391 if (cmd == PRC_MSGSIZE) { 1392 int valid = 0; 1393 1394 /* 1395 * Check to see if we have a valid TCP connection 1396 * corresponding to the address in the ICMPv6 message 1397 * payload. 1398 */ 1399 if (in6_pcblookup_connect(&tcbtable, &sa6->sin6_addr, 1400 th.th_dport, (struct in6_addr *)&sa6_src->sin6_addr, 1401 th.th_sport, 0)) 1402 valid++; 1403 1404 /* 1405 * Depending on the value of "valid" and routing table 1406 * size (mtudisc_{hi,lo}wat), we will: 1407 * - recalcurate the new MTU and create the 1408 * corresponding routing entry, or 1409 * - ignore the MTU change notification. 1410 */ 1411 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid); 1412 1413 /* 1414 * no need to call in6_pcbnotify, it should have been 1415 * called via callback if necessary 1416 */ 1417 return; 1418 } 1419 1420 nmatch = in6_pcbnotify(&tcbtable, sa, th.th_dport, 1421 (struct sockaddr *)sa6_src, th.th_sport, cmd, NULL, notify); 1422 if (nmatch == 0 && syn_cache_count && 1423 (inet6ctlerrmap[cmd] == EHOSTUNREACH || 1424 inet6ctlerrmap[cmd] == ENETUNREACH || 1425 inet6ctlerrmap[cmd] == EHOSTDOWN)) 1426 syn_cache_unreach((struct sockaddr *)sa6_src, 1427 sa, &th); 1428 } else { 1429 (void) in6_pcbnotify(&tcbtable, sa, 0, 1430 (struct sockaddr *)sa6_src, 0, cmd, NULL, notify); 1431 } 1432 } 1433 #endif 1434 1435 #ifdef INET 1436 /* assumes that ip header and tcp header are contiguous on mbuf */ 1437 void * 1438 tcp_ctlinput(cmd, sa, v) 1439 int cmd; 1440 struct sockaddr *sa; 1441 void *v; 1442 { 1443 struct ip *ip = v; 1444 struct tcphdr *th; 1445 struct icmp *icp; 1446 extern const int inetctlerrmap[]; 1447 void (*notify) __P((struct inpcb *, int)) = tcp_notify; 1448 int errno; 1449 int nmatch; 1450 #ifdef INET6 1451 struct in6_addr src6, dst6; 1452 #endif 1453 1454 if (sa->sa_family != AF_INET || 1455 sa->sa_len != sizeof(struct sockaddr_in)) 1456 return NULL; 1457 if ((unsigned)cmd >= PRC_NCMDS) 1458 return NULL; 1459 errno = inetctlerrmap[cmd]; 1460 if (cmd == PRC_QUENCH) 1461 notify = tcp_quench; 1462 else if (PRC_IS_REDIRECT(cmd)) 1463 notify = in_rtchange, ip = 0; 1464 else if (cmd == PRC_MSGSIZE && ip && ip->ip_v == 4) { 1465 /* 1466 * Check to see if we have a valid TCP connection 1467 * corresponding to the address in the ICMP message 1468 * payload. 1469 * 1470 * Boundary check is made in icmp_input(), with ICMP_ADVLENMIN. 1471 */ 1472 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1473 #ifdef INET6 1474 memset(&src6, 0, sizeof(src6)); 1475 memset(&dst6, 0, sizeof(dst6)); 1476 src6.s6_addr16[5] = dst6.s6_addr16[5] = 0xffff; 1477 memcpy(&src6.s6_addr32[3], &ip->ip_src, sizeof(struct in_addr)); 1478 memcpy(&dst6.s6_addr32[3], &ip->ip_dst, sizeof(struct in_addr)); 1479 #endif 1480 if (in_pcblookup_connect(&tcbtable, ip->ip_dst, th->th_dport, 1481 ip->ip_src, th->th_sport) != NULL) 1482 ; 1483 #ifdef INET6 1484 else if (in6_pcblookup_connect(&tcbtable, &dst6, 1485 th->th_dport, &src6, th->th_sport, 0) != NULL) 1486 ; 1487 #endif 1488 else 1489 return NULL; 1490 1491 /* 1492 * Now that we've validated that we are actually communicating 1493 * with the host indicated in the ICMP message, locate the 1494 * ICMP header, recalculate the new MTU, and create the 1495 * corresponding routing entry. 1496 */ 1497 icp = (struct icmp *)((caddr_t)ip - 1498 offsetof(struct icmp, icmp_ip)); 1499 icmp_mtudisc(icp, ip->ip_dst); 1500 1501 return NULL; 1502 } else if (cmd == PRC_HOSTDEAD) 1503 ip = 0; 1504 else if (errno == 0) 1505 return NULL; 1506 if (ip && ip->ip_v == 4 && sa->sa_family == AF_INET) { 1507 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1508 nmatch = in_pcbnotify(&tcbtable, satosin(sa)->sin_addr, 1509 th->th_dport, ip->ip_src, th->th_sport, errno, notify); 1510 if (nmatch == 0 && syn_cache_count && 1511 (inetctlerrmap[cmd] == EHOSTUNREACH || 1512 inetctlerrmap[cmd] == ENETUNREACH || 1513 inetctlerrmap[cmd] == EHOSTDOWN)) { 1514 struct sockaddr_in sin; 1515 bzero(&sin, sizeof(sin)); 1516 sin.sin_len = sizeof(sin); 1517 sin.sin_family = AF_INET; 1518 sin.sin_port = th->th_sport; 1519 sin.sin_addr = ip->ip_src; 1520 syn_cache_unreach((struct sockaddr *)&sin, sa, th); 1521 } 1522 1523 /* XXX mapped address case */ 1524 } else 1525 in_pcbnotifyall(&tcbtable, satosin(sa)->sin_addr, errno, 1526 notify); 1527 return NULL; 1528 } 1529 1530 /* 1531 * When a source quence is received, we are being notifed of congestion. 1532 * Close the congestion window down to the Loss Window (one segment). 1533 * We will gradually open it again as we proceed. 1534 */ 1535 void 1536 tcp_quench(inp, errno) 1537 struct inpcb *inp; 1538 int errno; 1539 { 1540 struct tcpcb *tp = intotcpcb(inp); 1541 1542 if (tp) 1543 tp->snd_cwnd = tp->t_segsz; 1544 } 1545 #endif 1546 1547 #ifdef INET6 1548 void 1549 tcp6_quench(in6p, errno) 1550 struct in6pcb *in6p; 1551 int errno; 1552 { 1553 struct tcpcb *tp = in6totcpcb(in6p); 1554 1555 if (tp) 1556 tp->snd_cwnd = tp->t_segsz; 1557 } 1558 #endif 1559 1560 #ifdef INET 1561 /* 1562 * Path MTU Discovery handlers. 1563 */ 1564 void 1565 tcp_mtudisc_callback(faddr) 1566 struct in_addr faddr; 1567 { 1568 #ifdef INET6 1569 struct in6_addr in6; 1570 #endif 1571 1572 in_pcbnotifyall(&tcbtable, faddr, EMSGSIZE, tcp_mtudisc); 1573 #ifdef INET6 1574 memset(&in6, 0, sizeof(in6)); 1575 in6.s6_addr16[5] = 0xffff; 1576 memcpy(&in6.s6_addr32[3], &faddr, sizeof(struct in_addr)); 1577 tcp6_mtudisc_callback(&in6); 1578 #endif 1579 } 1580 1581 /* 1582 * On receipt of path MTU corrections, flush old route and replace it 1583 * with the new one. Retransmit all unacknowledged packets, to ensure 1584 * that all packets will be received. 1585 */ 1586 void 1587 tcp_mtudisc(inp, errno) 1588 struct inpcb *inp; 1589 int errno; 1590 { 1591 struct tcpcb *tp = intotcpcb(inp); 1592 struct rtentry *rt = in_pcbrtentry(inp); 1593 1594 if (tp != 0) { 1595 if (rt != 0) { 1596 /* 1597 * If this was not a host route, remove and realloc. 1598 */ 1599 if ((rt->rt_flags & RTF_HOST) == 0) { 1600 in_rtchange(inp, errno); 1601 if ((rt = in_pcbrtentry(inp)) == 0) 1602 return; 1603 } 1604 1605 /* 1606 * Slow start out of the error condition. We 1607 * use the MTU because we know it's smaller 1608 * than the previously transmitted segment. 1609 * 1610 * Note: This is more conservative than the 1611 * suggestion in draft-floyd-incr-init-win-03. 1612 */ 1613 if (rt->rt_rmx.rmx_mtu != 0) 1614 tp->snd_cwnd = 1615 TCP_INITIAL_WINDOW(tcp_init_win, 1616 rt->rt_rmx.rmx_mtu); 1617 } 1618 1619 /* 1620 * Resend unacknowledged packets. 1621 */ 1622 tp->snd_nxt = tp->snd_una; 1623 tcp_output(tp); 1624 } 1625 } 1626 #endif 1627 1628 #ifdef INET6 1629 /* 1630 * Path MTU Discovery handlers. 1631 */ 1632 void 1633 tcp6_mtudisc_callback(faddr) 1634 struct in6_addr *faddr; 1635 { 1636 struct sockaddr_in6 sin6; 1637 1638 bzero(&sin6, sizeof(sin6)); 1639 sin6.sin6_family = AF_INET6; 1640 sin6.sin6_len = sizeof(struct sockaddr_in6); 1641 sin6.sin6_addr = *faddr; 1642 (void) in6_pcbnotify(&tcbtable, (struct sockaddr *)&sin6, 0, 1643 (struct sockaddr *)&sa6_any, 0, PRC_MSGSIZE, NULL, tcp6_mtudisc); 1644 } 1645 1646 void 1647 tcp6_mtudisc(in6p, errno) 1648 struct in6pcb *in6p; 1649 int errno; 1650 { 1651 struct tcpcb *tp = in6totcpcb(in6p); 1652 struct rtentry *rt = in6_pcbrtentry(in6p); 1653 1654 if (tp != 0) { 1655 if (rt != 0) { 1656 /* 1657 * If this was not a host route, remove and realloc. 1658 */ 1659 if ((rt->rt_flags & RTF_HOST) == 0) { 1660 in6_rtchange(in6p, errno); 1661 if ((rt = in6_pcbrtentry(in6p)) == 0) 1662 return; 1663 } 1664 1665 /* 1666 * Slow start out of the error condition. We 1667 * use the MTU because we know it's smaller 1668 * than the previously transmitted segment. 1669 * 1670 * Note: This is more conservative than the 1671 * suggestion in draft-floyd-incr-init-win-03. 1672 */ 1673 if (rt->rt_rmx.rmx_mtu != 0) 1674 tp->snd_cwnd = 1675 TCP_INITIAL_WINDOW(tcp_init_win, 1676 rt->rt_rmx.rmx_mtu); 1677 } 1678 1679 /* 1680 * Resend unacknowledged packets. 1681 */ 1682 tp->snd_nxt = tp->snd_una; 1683 tcp_output(tp); 1684 } 1685 } 1686 #endif /* INET6 */ 1687 1688 /* 1689 * Compute the MSS to advertise to the peer. Called only during 1690 * the 3-way handshake. If we are the server (peer initiated 1691 * connection), we are called with a pointer to the interface 1692 * on which the SYN packet arrived. If we are the client (we 1693 * initiated connection), we are called with a pointer to the 1694 * interface out which this connection should go. 1695 * 1696 * NOTE: Do not subtract IP option/extension header size nor IPsec 1697 * header size from MSS advertisement. MSS option must hold the maximum 1698 * segment size we can accept, so it must always be: 1699 * max(if mtu) - ip header - tcp header 1700 */ 1701 u_long 1702 tcp_mss_to_advertise(ifp, af) 1703 const struct ifnet *ifp; 1704 int af; 1705 { 1706 extern u_long in_maxmtu; 1707 u_long mss = 0; 1708 u_long hdrsiz; 1709 1710 /* 1711 * In order to avoid defeating path MTU discovery on the peer, 1712 * we advertise the max MTU of all attached networks as our MSS, 1713 * per RFC 1191, section 3.1. 1714 * 1715 * We provide the option to advertise just the MTU of 1716 * the interface on which we hope this connection will 1717 * be receiving. If we are responding to a SYN, we 1718 * will have a pretty good idea about this, but when 1719 * initiating a connection there is a bit more doubt. 1720 * 1721 * We also need to ensure that loopback has a large enough 1722 * MSS, as the loopback MTU is never included in in_maxmtu. 1723 */ 1724 1725 if (ifp != NULL) 1726 switch (af) { 1727 case AF_INET: 1728 mss = ifp->if_mtu; 1729 break; 1730 #ifdef INET6 1731 case AF_INET6: 1732 mss = IN6_LINKMTU(ifp); 1733 break; 1734 #endif 1735 } 1736 1737 if (tcp_mss_ifmtu == 0) 1738 switch (af) { 1739 case AF_INET: 1740 mss = max(in_maxmtu, mss); 1741 break; 1742 #ifdef INET6 1743 case AF_INET6: 1744 mss = max(in6_maxmtu, mss); 1745 break; 1746 #endif 1747 } 1748 1749 switch (af) { 1750 case AF_INET: 1751 hdrsiz = sizeof(struct ip); 1752 break; 1753 #ifdef INET6 1754 case AF_INET6: 1755 hdrsiz = sizeof(struct ip6_hdr); 1756 break; 1757 #endif 1758 default: 1759 hdrsiz = 0; 1760 break; 1761 } 1762 hdrsiz += sizeof(struct tcphdr); 1763 if (mss > hdrsiz) 1764 mss -= hdrsiz; 1765 1766 mss = max(tcp_mssdflt, mss); 1767 return (mss); 1768 } 1769 1770 /* 1771 * Set connection variables based on the peer's advertised MSS. 1772 * We are passed the TCPCB for the actual connection. If we 1773 * are the server, we are called by the compressed state engine 1774 * when the 3-way handshake is complete. If we are the client, 1775 * we are called when we receive the SYN,ACK from the server. 1776 * 1777 * NOTE: Our advertised MSS value must be initialized in the TCPCB 1778 * before this routine is called! 1779 */ 1780 void 1781 tcp_mss_from_peer(tp, offer) 1782 struct tcpcb *tp; 1783 int offer; 1784 { 1785 struct socket *so; 1786 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1787 struct rtentry *rt; 1788 #endif 1789 u_long bufsize; 1790 int mss; 1791 1792 #ifdef DIAGNOSTIC 1793 if (tp->t_inpcb && tp->t_in6pcb) 1794 panic("tcp_mss_from_peer: both t_inpcb and t_in6pcb are set"); 1795 #endif 1796 so = NULL; 1797 rt = NULL; 1798 #ifdef INET 1799 if (tp->t_inpcb) { 1800 so = tp->t_inpcb->inp_socket; 1801 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1802 rt = in_pcbrtentry(tp->t_inpcb); 1803 #endif 1804 } 1805 #endif 1806 #ifdef INET6 1807 if (tp->t_in6pcb) { 1808 so = tp->t_in6pcb->in6p_socket; 1809 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1810 rt = in6_pcbrtentry(tp->t_in6pcb); 1811 #endif 1812 } 1813 #endif 1814 1815 /* 1816 * As per RFC1122, use the default MSS value, unless they 1817 * sent us an offer. Do not accept offers less than 32 bytes. 1818 */ 1819 mss = tcp_mssdflt; 1820 if (offer) 1821 mss = offer; 1822 mss = max(mss, 32); /* sanity */ 1823 tp->t_peermss = mss; 1824 mss -= tcp_optlen(tp); 1825 #ifdef INET 1826 if (tp->t_inpcb) 1827 mss -= ip_optlen(tp->t_inpcb); 1828 #endif 1829 #ifdef INET6 1830 if (tp->t_in6pcb) 1831 mss -= ip6_optlen(tp->t_in6pcb); 1832 #endif 1833 1834 /* 1835 * If there's a pipesize, change the socket buffer to that size. 1836 * Make the socket buffer an integral number of MSS units. If 1837 * the MSS is larger than the socket buffer, artificially decrease 1838 * the MSS. 1839 */ 1840 #ifdef RTV_SPIPE 1841 if (rt != NULL && rt->rt_rmx.rmx_sendpipe != 0) 1842 bufsize = rt->rt_rmx.rmx_sendpipe; 1843 else 1844 #endif 1845 bufsize = so->so_snd.sb_hiwat; 1846 if (bufsize < mss) 1847 mss = bufsize; 1848 else { 1849 bufsize = roundup(bufsize, mss); 1850 if (bufsize > sb_max) 1851 bufsize = sb_max; 1852 (void) sbreserve(&so->so_snd, bufsize); 1853 } 1854 tp->t_segsz = mss; 1855 1856 #ifdef RTV_SSTHRESH 1857 if (rt != NULL && rt->rt_rmx.rmx_ssthresh) { 1858 /* 1859 * There's some sort of gateway or interface buffer 1860 * limit on the path. Use this to set the slow 1861 * start threshold, but set the threshold to no less 1862 * than 2 * MSS. 1863 */ 1864 tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh); 1865 } 1866 #endif 1867 } 1868 1869 /* 1870 * Processing necessary when a TCP connection is established. 1871 */ 1872 void 1873 tcp_established(tp) 1874 struct tcpcb *tp; 1875 { 1876 struct socket *so; 1877 #ifdef RTV_RPIPE 1878 struct rtentry *rt; 1879 #endif 1880 u_long bufsize; 1881 1882 #ifdef DIAGNOSTIC 1883 if (tp->t_inpcb && tp->t_in6pcb) 1884 panic("tcp_established: both t_inpcb and t_in6pcb are set"); 1885 #endif 1886 so = NULL; 1887 rt = NULL; 1888 #ifdef INET 1889 if (tp->t_inpcb) { 1890 so = tp->t_inpcb->inp_socket; 1891 #if defined(RTV_RPIPE) 1892 rt = in_pcbrtentry(tp->t_inpcb); 1893 #endif 1894 } 1895 #endif 1896 #ifdef INET6 1897 if (tp->t_in6pcb) { 1898 so = tp->t_in6pcb->in6p_socket; 1899 #if defined(RTV_RPIPE) 1900 rt = in6_pcbrtentry(tp->t_in6pcb); 1901 #endif 1902 } 1903 #endif 1904 1905 tp->t_state = TCPS_ESTABLISHED; 1906 TCP_TIMER_ARM(tp, TCPT_KEEP, tcp_keepidle); 1907 1908 #ifdef RTV_RPIPE 1909 if (rt != NULL && rt->rt_rmx.rmx_recvpipe != 0) 1910 bufsize = rt->rt_rmx.rmx_recvpipe; 1911 else 1912 #endif 1913 bufsize = so->so_rcv.sb_hiwat; 1914 if (bufsize > tp->t_ourmss) { 1915 bufsize = roundup(bufsize, tp->t_ourmss); 1916 if (bufsize > sb_max) 1917 bufsize = sb_max; 1918 (void) sbreserve(&so->so_rcv, bufsize); 1919 } 1920 } 1921 1922 /* 1923 * Check if there's an initial rtt or rttvar. Convert from the 1924 * route-table units to scaled multiples of the slow timeout timer. 1925 * Called only during the 3-way handshake. 1926 */ 1927 void 1928 tcp_rmx_rtt(tp) 1929 struct tcpcb *tp; 1930 { 1931 #ifdef RTV_RTT 1932 struct rtentry *rt = NULL; 1933 int rtt; 1934 1935 #ifdef DIAGNOSTIC 1936 if (tp->t_inpcb && tp->t_in6pcb) 1937 panic("tcp_rmx_rtt: both t_inpcb and t_in6pcb are set"); 1938 #endif 1939 #ifdef INET 1940 if (tp->t_inpcb) 1941 rt = in_pcbrtentry(tp->t_inpcb); 1942 #endif 1943 #ifdef INET6 1944 if (tp->t_in6pcb) 1945 rt = in6_pcbrtentry(tp->t_in6pcb); 1946 #endif 1947 if (rt == NULL) 1948 return; 1949 1950 if (tp->t_srtt == 0 && (rtt = rt->rt_rmx.rmx_rtt)) { 1951 /* 1952 * XXX The lock bit for MTU indicates that the value 1953 * is also a minimum value; this is subject to time. 1954 */ 1955 if (rt->rt_rmx.rmx_locks & RTV_RTT) 1956 TCPT_RANGESET(tp->t_rttmin, 1957 rtt / (RTM_RTTUNIT / PR_SLOWHZ), 1958 TCPTV_MIN, TCPTV_REXMTMAX); 1959 tp->t_srtt = rtt / 1960 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 1961 if (rt->rt_rmx.rmx_rttvar) { 1962 tp->t_rttvar = rt->rt_rmx.rmx_rttvar / 1963 ((RTM_RTTUNIT / PR_SLOWHZ) >> 1964 (TCP_RTTVAR_SHIFT + 2)); 1965 } else { 1966 /* Default variation is +- 1 rtt */ 1967 tp->t_rttvar = 1968 tp->t_srtt >> (TCP_RTT_SHIFT - TCP_RTTVAR_SHIFT); 1969 } 1970 TCPT_RANGESET(tp->t_rxtcur, 1971 ((tp->t_srtt >> 2) + tp->t_rttvar) >> (1 + 2), 1972 tp->t_rttmin, TCPTV_REXMTMAX); 1973 } 1974 #endif 1975 } 1976 1977 tcp_seq tcp_iss_seq = 0; /* tcp initial seq # */ 1978 #if NRND > 0 1979 u_int8_t tcp_iss_secret[16]; /* 128 bits; should be plenty */ 1980 #endif 1981 1982 /* 1983 * Get a new sequence value given a tcp control block 1984 */ 1985 tcp_seq 1986 tcp_new_iss(struct tcpcb *tp, tcp_seq addin) 1987 { 1988 1989 #ifdef INET 1990 if (tp->t_inpcb != NULL) { 1991 return (tcp_new_iss1(&tp->t_inpcb->inp_laddr, 1992 &tp->t_inpcb->inp_faddr, tp->t_inpcb->inp_lport, 1993 tp->t_inpcb->inp_fport, sizeof(tp->t_inpcb->inp_laddr), 1994 addin)); 1995 } 1996 #endif 1997 #ifdef INET6 1998 if (tp->t_in6pcb != NULL) { 1999 return (tcp_new_iss1(&tp->t_in6pcb->in6p_laddr, 2000 &tp->t_in6pcb->in6p_faddr, tp->t_in6pcb->in6p_lport, 2001 tp->t_in6pcb->in6p_fport, sizeof(tp->t_in6pcb->in6p_laddr), 2002 addin)); 2003 } 2004 #endif 2005 /* Not possible. */ 2006 panic("tcp_new_iss"); 2007 } 2008 2009 /* 2010 * This routine actually generates a new TCP initial sequence number. 2011 */ 2012 tcp_seq 2013 tcp_new_iss1(void *laddr, void *faddr, u_int16_t lport, u_int16_t fport, 2014 size_t addrsz, tcp_seq addin) 2015 { 2016 tcp_seq tcp_iss; 2017 2018 #if NRND > 0 2019 static int beenhere; 2020 2021 /* 2022 * If we haven't been here before, initialize our cryptographic 2023 * hash secret. 2024 */ 2025 if (beenhere == 0) { 2026 rnd_extract_data(tcp_iss_secret, sizeof(tcp_iss_secret), 2027 RND_EXTRACT_ANY); 2028 beenhere = 1; 2029 } 2030 2031 if (tcp_do_rfc1948) { 2032 MD5_CTX ctx; 2033 u_int8_t hash[16]; /* XXX MD5 knowledge */ 2034 2035 /* 2036 * Compute the base value of the ISS. It is a hash 2037 * of (saddr, sport, daddr, dport, secret). 2038 */ 2039 MD5Init(&ctx); 2040 2041 MD5Update(&ctx, (u_char *) laddr, addrsz); 2042 MD5Update(&ctx, (u_char *) &lport, sizeof(lport)); 2043 2044 MD5Update(&ctx, (u_char *) faddr, addrsz); 2045 MD5Update(&ctx, (u_char *) &fport, sizeof(fport)); 2046 2047 MD5Update(&ctx, tcp_iss_secret, sizeof(tcp_iss_secret)); 2048 2049 MD5Final(hash, &ctx); 2050 2051 memcpy(&tcp_iss, hash, sizeof(tcp_iss)); 2052 2053 /* 2054 * Now increment our "timer", and add it in to 2055 * the computed value. 2056 * 2057 * XXX Use `addin'? 2058 * XXX TCP_ISSINCR too large to use? 2059 */ 2060 tcp_iss_seq += TCP_ISSINCR; 2061 #ifdef TCPISS_DEBUG 2062 printf("ISS hash 0x%08x, ", tcp_iss); 2063 #endif 2064 tcp_iss += tcp_iss_seq + addin; 2065 #ifdef TCPISS_DEBUG 2066 printf("new ISS 0x%08x\n", tcp_iss); 2067 #endif 2068 } else 2069 #endif /* NRND > 0 */ 2070 { 2071 /* 2072 * Randomize. 2073 */ 2074 #if NRND > 0 2075 rnd_extract_data(&tcp_iss, sizeof(tcp_iss), RND_EXTRACT_ANY); 2076 #else 2077 tcp_iss = arc4random(); 2078 #endif 2079 2080 /* 2081 * If we were asked to add some amount to a known value, 2082 * we will take a random value obtained above, mask off 2083 * the upper bits, and add in the known value. We also 2084 * add in a constant to ensure that we are at least a 2085 * certain distance from the original value. 2086 * 2087 * This is used when an old connection is in timed wait 2088 * and we have a new one coming in, for instance. 2089 */ 2090 if (addin != 0) { 2091 #ifdef TCPISS_DEBUG 2092 printf("Random %08x, ", tcp_iss); 2093 #endif 2094 tcp_iss &= TCP_ISS_RANDOM_MASK; 2095 tcp_iss += addin + TCP_ISSINCR; 2096 #ifdef TCPISS_DEBUG 2097 printf("Old ISS %08x, ISS %08x\n", addin, tcp_iss); 2098 #endif 2099 } else { 2100 tcp_iss &= TCP_ISS_RANDOM_MASK; 2101 tcp_iss += tcp_iss_seq; 2102 tcp_iss_seq += TCP_ISSINCR; 2103 #ifdef TCPISS_DEBUG 2104 printf("ISS %08x\n", tcp_iss); 2105 #endif 2106 } 2107 } 2108 2109 if (tcp_compat_42) { 2110 /* 2111 * Limit it to the positive range for really old TCP 2112 * implementations. 2113 * Just AND off the top bit instead of checking if 2114 * is set first - saves a branch 50% of the time. 2115 */ 2116 tcp_iss &= 0x7fffffff; /* XXX */ 2117 } 2118 2119 return (tcp_iss); 2120 } 2121 2122 #if defined(IPSEC) || defined(FAST_IPSEC) 2123 /* compute ESP/AH header size for TCP, including outer IP header. */ 2124 size_t 2125 ipsec4_hdrsiz_tcp(tp) 2126 struct tcpcb *tp; 2127 { 2128 struct inpcb *inp; 2129 size_t hdrsiz; 2130 2131 /* XXX mapped addr case (tp->t_in6pcb) */ 2132 if (!tp || !tp->t_template || !(inp = tp->t_inpcb)) 2133 return 0; 2134 switch (tp->t_family) { 2135 case AF_INET: 2136 /* XXX: should use currect direction. */ 2137 hdrsiz = ipsec4_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, inp); 2138 break; 2139 default: 2140 hdrsiz = 0; 2141 break; 2142 } 2143 2144 return hdrsiz; 2145 } 2146 2147 #ifdef INET6 2148 size_t 2149 ipsec6_hdrsiz_tcp(tp) 2150 struct tcpcb *tp; 2151 { 2152 struct in6pcb *in6p; 2153 size_t hdrsiz; 2154 2155 if (!tp || !tp->t_template || !(in6p = tp->t_in6pcb)) 2156 return 0; 2157 switch (tp->t_family) { 2158 case AF_INET6: 2159 /* XXX: should use currect direction. */ 2160 hdrsiz = ipsec6_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, in6p); 2161 break; 2162 case AF_INET: 2163 /* mapped address case - tricky */ 2164 default: 2165 hdrsiz = 0; 2166 break; 2167 } 2168 2169 return hdrsiz; 2170 } 2171 #endif 2172 #endif /*IPSEC*/ 2173 2174 /* 2175 * Determine the length of the TCP options for this connection. 2176 * 2177 * XXX: What do we do for SACK, when we add that? Just reserve 2178 * all of the space? Otherwise we can't exactly be incrementing 2179 * cwnd by an amount that varies depending on the amount we last 2180 * had to SACK! 2181 */ 2182 2183 u_int 2184 tcp_optlen(tp) 2185 struct tcpcb *tp; 2186 { 2187 if ((tp->t_flags & (TF_REQ_TSTMP|TF_RCVD_TSTMP|TF_NOOPT)) == 2188 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 2189 return TCPOLEN_TSTAMP_APPA; 2190 else 2191 return 0; 2192 } 2193
Indexes created Sun Sep 21 16:09:51 GMT 2025