tcp_subr.c revision 1.176
1 /* $NetBSD: tcp_subr.c,v 1.176 2004/12/19 06:42:24 christos 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 1.176 2004/12/19 06:42:24 christos 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 #include <netkey/key.h> 159 #endif /*IPSEC*/ 160 161 #ifdef FAST_IPSEC 162 #include <netipsec/ipsec.h> 163 #include <netipsec/xform.h> 164 #ifdef INET6 165 #include <netipsec/ipsec6.h> 166 #endif 167 #include <netipsec/key.h> 168 #endif /* FAST_IPSEC*/ 169 170 171 struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 172 struct tcpstat tcpstat; /* tcp statistics */ 173 u_int32_t tcp_now; /* for RFC 1323 timestamps */ 174 175 /* patchable/settable parameters for tcp */ 176 int tcp_mssdflt = TCP_MSS; 177 int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 178 int tcp_do_rfc1323 = 1; /* window scaling / timestamps (obsolete) */ 179 #if NRND > 0 180 int tcp_do_rfc1948 = 0; /* ISS by cryptographic hash */ 181 #endif 182 int tcp_do_sack = 1; /* selective acknowledgement */ 183 int tcp_do_win_scale = 1; /* RFC1323 window scaling */ 184 int tcp_do_timestamps = 1; /* RFC1323 timestamps */ 185 int tcp_do_newreno = 1; /* Use the New Reno algorithms */ 186 int tcp_ack_on_push = 0; /* set to enable immediate ACK-on-PUSH */ 187 #ifndef TCP_INIT_WIN 188 #define TCP_INIT_WIN 0 /* initial slow start window */ 189 #endif 190 #ifndef TCP_INIT_WIN_LOCAL 191 #define TCP_INIT_WIN_LOCAL 4 /* initial slow start window for local nets */ 192 #endif 193 int tcp_init_win = TCP_INIT_WIN; 194 int tcp_init_win_local = TCP_INIT_WIN_LOCAL; 195 int tcp_mss_ifmtu = 0; 196 #ifdef TCP_COMPAT_42 197 int tcp_compat_42 = 1; 198 #else 199 int tcp_compat_42 = 0; 200 #endif 201 int tcp_rst_ppslim = 100; /* 100pps */ 202 int tcp_ackdrop_ppslim = 100; /* 100pps */ 203 int tcp_do_loopback_cksum = 0; 204 205 /* tcb hash */ 206 #ifndef TCBHASHSIZE 207 #define TCBHASHSIZE 128 208 #endif 209 int tcbhashsize = TCBHASHSIZE; 210 211 /* syn hash parameters */ 212 #define TCP_SYN_HASH_SIZE 293 213 #define TCP_SYN_BUCKET_SIZE 35 214 int tcp_syn_cache_size = TCP_SYN_HASH_SIZE; 215 int tcp_syn_cache_limit = TCP_SYN_HASH_SIZE*TCP_SYN_BUCKET_SIZE; 216 int tcp_syn_bucket_limit = 3*TCP_SYN_BUCKET_SIZE; 217 struct syn_cache_head tcp_syn_cache[TCP_SYN_HASH_SIZE]; 218 219 int tcp_freeq __P((struct tcpcb *)); 220 221 #ifdef INET 222 void tcp_mtudisc_callback __P((struct in_addr)); 223 #endif 224 #ifdef INET6 225 void tcp6_mtudisc_callback __P((struct in6_addr *)); 226 #endif 227 228 void tcp_mtudisc __P((struct inpcb *, int)); 229 #ifdef INET6 230 void tcp6_mtudisc __P((struct in6pcb *, int)); 231 #endif 232 233 POOL_INIT(tcpcb_pool, sizeof(struct tcpcb), 0, 0, 0, "tcpcbpl", NULL); 234 235 #ifdef TCP_CSUM_COUNTERS 236 #include <sys/device.h> 237 238 struct evcnt tcp_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 239 NULL, "tcp", "hwcsum bad"); 240 struct evcnt tcp_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 241 NULL, "tcp", "hwcsum ok"); 242 struct evcnt tcp_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 243 NULL, "tcp", "hwcsum data"); 244 struct evcnt tcp_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 245 NULL, "tcp", "swcsum"); 246 247 EVCNT_ATTACH_STATIC(tcp_hwcsum_bad); 248 EVCNT_ATTACH_STATIC(tcp_hwcsum_ok); 249 EVCNT_ATTACH_STATIC(tcp_hwcsum_data); 250 EVCNT_ATTACH_STATIC(tcp_swcsum); 251 #endif /* TCP_CSUM_COUNTERS */ 252 253 254 #ifdef TCP_OUTPUT_COUNTERS 255 #include <sys/device.h> 256 257 struct evcnt tcp_output_bigheader = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 258 NULL, "tcp", "output big header"); 259 struct evcnt tcp_output_predict_hit = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 260 NULL, "tcp", "output predict hit"); 261 struct evcnt tcp_output_predict_miss = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 262 NULL, "tcp", "output predict miss"); 263 struct evcnt tcp_output_copysmall = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 264 NULL, "tcp", "output copy small"); 265 struct evcnt tcp_output_copybig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 266 NULL, "tcp", "output copy big"); 267 struct evcnt tcp_output_refbig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 268 NULL, "tcp", "output reference big"); 269 270 EVCNT_ATTACH_STATIC(tcp_output_bigheader); 271 EVCNT_ATTACH_STATIC(tcp_output_predict_hit); 272 EVCNT_ATTACH_STATIC(tcp_output_predict_miss); 273 EVCNT_ATTACH_STATIC(tcp_output_copysmall); 274 EVCNT_ATTACH_STATIC(tcp_output_copybig); 275 EVCNT_ATTACH_STATIC(tcp_output_refbig); 276 277 #endif /* TCP_OUTPUT_COUNTERS */ 278 279 #ifdef TCP_REASS_COUNTERS 280 #include <sys/device.h> 281 282 struct evcnt tcp_reass_ = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 283 NULL, "tcp_reass", "calls"); 284 struct evcnt tcp_reass_empty = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 285 &tcp_reass_, "tcp_reass", "insert into empty queue"); 286 struct evcnt tcp_reass_iteration[8] = { 287 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", ">7 iterations"), 288 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "1 iteration"), 289 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "2 iterations"), 290 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "3 iterations"), 291 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "4 iterations"), 292 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "5 iterations"), 293 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "6 iterations"), 294 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "7 iterations"), 295 }; 296 struct evcnt tcp_reass_prependfirst = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 297 &tcp_reass_, "tcp_reass", "prepend to first"); 298 struct evcnt tcp_reass_prepend = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 299 &tcp_reass_, "tcp_reass", "prepend"); 300 struct evcnt tcp_reass_insert = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 301 &tcp_reass_, "tcp_reass", "insert"); 302 struct evcnt tcp_reass_inserttail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 303 &tcp_reass_, "tcp_reass", "insert at tail"); 304 struct evcnt tcp_reass_append = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 305 &tcp_reass_, "tcp_reass", "append"); 306 struct evcnt tcp_reass_appendtail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 307 &tcp_reass_, "tcp_reass", "append to tail fragment"); 308 struct evcnt tcp_reass_overlaptail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 309 &tcp_reass_, "tcp_reass", "overlap at end"); 310 struct evcnt tcp_reass_overlapfront = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 311 &tcp_reass_, "tcp_reass", "overlap at start"); 312 struct evcnt tcp_reass_segdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 313 &tcp_reass_, "tcp_reass", "duplicate segment"); 314 struct evcnt tcp_reass_fragdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 315 &tcp_reass_, "tcp_reass", "duplicate fragment"); 316 317 EVCNT_ATTACH_STATIC(tcp_reass_); 318 EVCNT_ATTACH_STATIC(tcp_reass_empty); 319 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 0); 320 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 1); 321 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 2); 322 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 3); 323 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 4); 324 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 5); 325 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 6); 326 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 7); 327 EVCNT_ATTACH_STATIC(tcp_reass_prependfirst); 328 EVCNT_ATTACH_STATIC(tcp_reass_prepend); 329 EVCNT_ATTACH_STATIC(tcp_reass_insert); 330 EVCNT_ATTACH_STATIC(tcp_reass_inserttail); 331 EVCNT_ATTACH_STATIC(tcp_reass_append); 332 EVCNT_ATTACH_STATIC(tcp_reass_appendtail); 333 EVCNT_ATTACH_STATIC(tcp_reass_overlaptail); 334 EVCNT_ATTACH_STATIC(tcp_reass_overlapfront); 335 EVCNT_ATTACH_STATIC(tcp_reass_segdup); 336 EVCNT_ATTACH_STATIC(tcp_reass_fragdup); 337 338 #endif /* TCP_REASS_COUNTERS */ 339 340 #ifdef MBUFTRACE 341 struct mowner tcp_mowner = { "tcp" }; 342 struct mowner tcp_rx_mowner = { "tcp", "rx" }; 343 struct mowner tcp_tx_mowner = { "tcp", "tx" }; 344 #endif 345 346 /* 347 * Tcp initialization 348 */ 349 void 350 tcp_init() 351 { 352 int hlen; 353 354 /* Initialize the TCPCB template. */ 355 tcp_tcpcb_template(); 356 357 in_pcbinit(&tcbtable, tcbhashsize, tcbhashsize); 358 359 hlen = sizeof(struct ip) + sizeof(struct tcphdr); 360 #ifdef INET6 361 if (sizeof(struct ip) < sizeof(struct ip6_hdr)) 362 hlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 363 #endif 364 if (max_protohdr < hlen) 365 max_protohdr = hlen; 366 if (max_linkhdr + hlen > MHLEN) 367 panic("tcp_init"); 368 369 #ifdef INET 370 icmp_mtudisc_callback_register(tcp_mtudisc_callback); 371 #endif 372 #ifdef INET6 373 icmp6_mtudisc_callback_register(tcp6_mtudisc_callback); 374 #endif 375 376 /* Initialize timer state. */ 377 tcp_timer_init(); 378 379 /* Initialize the compressed state engine. */ 380 syn_cache_init(); 381 382 MOWNER_ATTACH(&tcp_tx_mowner); 383 MOWNER_ATTACH(&tcp_rx_mowner); 384 MOWNER_ATTACH(&tcp_mowner); 385 } 386 387 /* 388 * Create template to be used to send tcp packets on a connection. 389 * Call after host entry created, allocates an mbuf and fills 390 * in a skeletal tcp/ip header, minimizing the amount of work 391 * necessary when the connection is used. 392 */ 393 struct mbuf * 394 tcp_template(tp) 395 struct tcpcb *tp; 396 { 397 struct inpcb *inp = tp->t_inpcb; 398 #ifdef INET6 399 struct in6pcb *in6p = tp->t_in6pcb; 400 #endif 401 struct tcphdr *n; 402 struct mbuf *m; 403 int hlen; 404 405 switch (tp->t_family) { 406 case AF_INET: 407 hlen = sizeof(struct ip); 408 if (inp) 409 break; 410 #ifdef INET6 411 if (in6p) { 412 /* mapped addr case */ 413 if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr) 414 && IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) 415 break; 416 } 417 #endif 418 return NULL; /*EINVAL*/ 419 #ifdef INET6 420 case AF_INET6: 421 hlen = sizeof(struct ip6_hdr); 422 if (in6p) { 423 /* more sainty check? */ 424 break; 425 } 426 return NULL; /*EINVAL*/ 427 #endif 428 default: 429 hlen = 0; /*pacify gcc*/ 430 return NULL; /*EAFNOSUPPORT*/ 431 } 432 #ifdef DIAGNOSTIC 433 if (hlen + sizeof(struct tcphdr) > MCLBYTES) 434 panic("mclbytes too small for t_template"); 435 #endif 436 m = tp->t_template; 437 if (m && m->m_len == hlen + sizeof(struct tcphdr)) 438 ; 439 else { 440 if (m) 441 m_freem(m); 442 m = tp->t_template = NULL; 443 MGETHDR(m, M_DONTWAIT, MT_HEADER); 444 if (m && hlen + sizeof(struct tcphdr) > MHLEN) { 445 MCLGET(m, M_DONTWAIT); 446 if ((m->m_flags & M_EXT) == 0) { 447 m_free(m); 448 m = NULL; 449 } 450 } 451 if (m == NULL) 452 return NULL; 453 MCLAIM(m, &tcp_mowner); 454 m->m_pkthdr.len = m->m_len = hlen + sizeof(struct tcphdr); 455 } 456 457 bzero(mtod(m, caddr_t), m->m_len); 458 459 n = (struct tcphdr *)(mtod(m, caddr_t) + hlen); 460 461 switch (tp->t_family) { 462 case AF_INET: 463 { 464 struct ipovly *ipov; 465 mtod(m, struct ip *)->ip_v = 4; 466 mtod(m, struct ip *)->ip_hl = hlen >> 2; 467 ipov = mtod(m, struct ipovly *); 468 ipov->ih_pr = IPPROTO_TCP; 469 ipov->ih_len = htons(sizeof(struct tcphdr)); 470 if (inp) { 471 ipov->ih_src = inp->inp_laddr; 472 ipov->ih_dst = inp->inp_faddr; 473 } 474 #ifdef INET6 475 else if (in6p) { 476 /* mapped addr case */ 477 bcopy(&in6p->in6p_laddr.s6_addr32[3], &ipov->ih_src, 478 sizeof(ipov->ih_src)); 479 bcopy(&in6p->in6p_faddr.s6_addr32[3], &ipov->ih_dst, 480 sizeof(ipov->ih_dst)); 481 } 482 #endif 483 /* 484 * Compute the pseudo-header portion of the checksum 485 * now. We incrementally add in the TCP option and 486 * payload lengths later, and then compute the TCP 487 * checksum right before the packet is sent off onto 488 * the wire. 489 */ 490 n->th_sum = in_cksum_phdr(ipov->ih_src.s_addr, 491 ipov->ih_dst.s_addr, 492 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 493 break; 494 } 495 #ifdef INET6 496 case AF_INET6: 497 { 498 struct ip6_hdr *ip6; 499 mtod(m, struct ip *)->ip_v = 6; 500 ip6 = mtod(m, struct ip6_hdr *); 501 ip6->ip6_nxt = IPPROTO_TCP; 502 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 503 ip6->ip6_src = in6p->in6p_laddr; 504 ip6->ip6_dst = in6p->in6p_faddr; 505 ip6->ip6_flow = in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK; 506 if (ip6_auto_flowlabel) { 507 ip6->ip6_flow &= ~IPV6_FLOWLABEL_MASK; 508 ip6->ip6_flow |= 509 (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK); 510 } 511 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 512 ip6->ip6_vfc |= IPV6_VERSION; 513 514 /* 515 * Compute the pseudo-header portion of the checksum 516 * now. We incrementally add in the TCP option and 517 * payload lengths later, and then compute the TCP 518 * checksum right before the packet is sent off onto 519 * the wire. 520 */ 521 n->th_sum = in6_cksum_phdr(&in6p->in6p_laddr, 522 &in6p->in6p_faddr, htonl(sizeof(struct tcphdr)), 523 htonl(IPPROTO_TCP)); 524 break; 525 } 526 #endif 527 } 528 if (inp) { 529 n->th_sport = inp->inp_lport; 530 n->th_dport = inp->inp_fport; 531 } 532 #ifdef INET6 533 else if (in6p) { 534 n->th_sport = in6p->in6p_lport; 535 n->th_dport = in6p->in6p_fport; 536 } 537 #endif 538 n->th_seq = 0; 539 n->th_ack = 0; 540 n->th_x2 = 0; 541 n->th_off = 5; 542 n->th_flags = 0; 543 n->th_win = 0; 544 n->th_urp = 0; 545 return (m); 546 } 547 548 /* 549 * Send a single message to the TCP at address specified by 550 * the given TCP/IP header. If m == 0, then we make a copy 551 * of the tcpiphdr at ti and send directly to the addressed host. 552 * This is used to force keep alive messages out using the TCP 553 * template for a connection tp->t_template. If flags are given 554 * then we send a message back to the TCP which originated the 555 * segment ti, and discard the mbuf containing it and any other 556 * attached mbufs. 557 * 558 * In any case the ack and sequence number of the transmitted 559 * segment are as specified by the parameters. 560 */ 561 int 562 tcp_respond(tp, template, m, th0, ack, seq, flags) 563 struct tcpcb *tp; 564 struct mbuf *template; 565 struct mbuf *m; 566 struct tcphdr *th0; 567 tcp_seq ack, seq; 568 int flags; 569 { 570 struct route *ro; 571 int error, tlen, win = 0; 572 int hlen; 573 struct ip *ip; 574 #ifdef INET6 575 struct ip6_hdr *ip6; 576 #endif 577 int family; /* family on packet, not inpcb/in6pcb! */ 578 struct tcphdr *th; 579 struct socket *so; 580 581 if (tp != NULL && (flags & TH_RST) == 0) { 582 #ifdef DIAGNOSTIC 583 if (tp->t_inpcb && tp->t_in6pcb) 584 panic("tcp_respond: both t_inpcb and t_in6pcb are set"); 585 #endif 586 #ifdef INET 587 if (tp->t_inpcb) 588 win = sbspace(&tp->t_inpcb->inp_socket->so_rcv); 589 #endif 590 #ifdef INET6 591 if (tp->t_in6pcb) 592 win = sbspace(&tp->t_in6pcb->in6p_socket->so_rcv); 593 #endif 594 } 595 596 th = NULL; /* Quell uninitialized warning */ 597 ip = NULL; 598 #ifdef INET6 599 ip6 = NULL; 600 #endif 601 if (m == 0) { 602 if (!template) 603 return EINVAL; 604 605 /* get family information from template */ 606 switch (mtod(template, struct ip *)->ip_v) { 607 case 4: 608 family = AF_INET; 609 hlen = sizeof(struct ip); 610 break; 611 #ifdef INET6 612 case 6: 613 family = AF_INET6; 614 hlen = sizeof(struct ip6_hdr); 615 break; 616 #endif 617 default: 618 return EAFNOSUPPORT; 619 } 620 621 MGETHDR(m, M_DONTWAIT, MT_HEADER); 622 if (m) { 623 MCLAIM(m, &tcp_tx_mowner); 624 MCLGET(m, M_DONTWAIT); 625 if ((m->m_flags & M_EXT) == 0) { 626 m_free(m); 627 m = NULL; 628 } 629 } 630 if (m == NULL) 631 return (ENOBUFS); 632 633 if (tcp_compat_42) 634 tlen = 1; 635 else 636 tlen = 0; 637 638 m->m_data += max_linkhdr; 639 bcopy(mtod(template, caddr_t), mtod(m, caddr_t), 640 template->m_len); 641 switch (family) { 642 case AF_INET: 643 ip = mtod(m, struct ip *); 644 th = (struct tcphdr *)(ip + 1); 645 break; 646 #ifdef INET6 647 case AF_INET6: 648 ip6 = mtod(m, struct ip6_hdr *); 649 th = (struct tcphdr *)(ip6 + 1); 650 break; 651 #endif 652 #if 0 653 default: 654 /* noone will visit here */ 655 m_freem(m); 656 return EAFNOSUPPORT; 657 #endif 658 } 659 flags = TH_ACK; 660 } else { 661 662 if ((m->m_flags & M_PKTHDR) == 0) { 663 #if 0 664 printf("non PKTHDR to tcp_respond\n"); 665 #endif 666 m_freem(m); 667 return EINVAL; 668 } 669 #ifdef DIAGNOSTIC 670 if (!th0) 671 panic("th0 == NULL in tcp_respond"); 672 #endif 673 674 /* get family information from m */ 675 switch (mtod(m, struct ip *)->ip_v) { 676 case 4: 677 family = AF_INET; 678 hlen = sizeof(struct ip); 679 ip = mtod(m, struct ip *); 680 break; 681 #ifdef INET6 682 case 6: 683 family = AF_INET6; 684 hlen = sizeof(struct ip6_hdr); 685 ip6 = mtod(m, struct ip6_hdr *); 686 break; 687 #endif 688 default: 689 m_freem(m); 690 return EAFNOSUPPORT; 691 } 692 if ((flags & TH_SYN) == 0 || sizeof(*th0) > (th0->th_off << 2)) 693 tlen = sizeof(*th0); 694 else 695 tlen = th0->th_off << 2; 696 697 if (m->m_len > hlen + tlen && (m->m_flags & M_EXT) == 0 && 698 mtod(m, caddr_t) + hlen == (caddr_t)th0) { 699 m->m_len = hlen + tlen; 700 m_freem(m->m_next); 701 m->m_next = NULL; 702 } else { 703 struct mbuf *n; 704 705 #ifdef DIAGNOSTIC 706 if (max_linkhdr + hlen + tlen > MCLBYTES) { 707 m_freem(m); 708 return EMSGSIZE; 709 } 710 #endif 711 MGETHDR(n, M_DONTWAIT, MT_HEADER); 712 if (n && max_linkhdr + hlen + tlen > MHLEN) { 713 MCLGET(n, M_DONTWAIT); 714 if ((n->m_flags & M_EXT) == 0) { 715 m_freem(n); 716 n = NULL; 717 } 718 } 719 if (!n) { 720 m_freem(m); 721 return ENOBUFS; 722 } 723 724 MCLAIM(n, &tcp_tx_mowner); 725 n->m_data += max_linkhdr; 726 n->m_len = hlen + tlen; 727 m_copyback(n, 0, hlen, mtod(m, caddr_t)); 728 m_copyback(n, hlen, tlen, (caddr_t)th0); 729 730 m_freem(m); 731 m = n; 732 n = NULL; 733 } 734 735 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 736 switch (family) { 737 case AF_INET: 738 ip = mtod(m, struct ip *); 739 th = (struct tcphdr *)(ip + 1); 740 ip->ip_p = IPPROTO_TCP; 741 xchg(ip->ip_dst, ip->ip_src, struct in_addr); 742 ip->ip_p = IPPROTO_TCP; 743 break; 744 #ifdef INET6 745 case AF_INET6: 746 ip6 = mtod(m, struct ip6_hdr *); 747 th = (struct tcphdr *)(ip6 + 1); 748 ip6->ip6_nxt = IPPROTO_TCP; 749 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 750 ip6->ip6_nxt = IPPROTO_TCP; 751 break; 752 #endif 753 #if 0 754 default: 755 /* noone will visit here */ 756 m_freem(m); 757 return EAFNOSUPPORT; 758 #endif 759 } 760 xchg(th->th_dport, th->th_sport, u_int16_t); 761 #undef xchg 762 tlen = 0; /*be friendly with the following code*/ 763 } 764 th->th_seq = htonl(seq); 765 th->th_ack = htonl(ack); 766 th->th_x2 = 0; 767 if ((flags & TH_SYN) == 0) { 768 if (tp) 769 win >>= tp->rcv_scale; 770 if (win > TCP_MAXWIN) 771 win = TCP_MAXWIN; 772 th->th_win = htons((u_int16_t)win); 773 th->th_off = sizeof (struct tcphdr) >> 2; 774 tlen += sizeof(*th); 775 } else 776 tlen += th->th_off << 2; 777 m->m_len = hlen + tlen; 778 m->m_pkthdr.len = hlen + tlen; 779 m->m_pkthdr.rcvif = (struct ifnet *) 0; 780 th->th_flags = flags; 781 th->th_urp = 0; 782 783 switch (family) { 784 #ifdef INET 785 case AF_INET: 786 { 787 struct ipovly *ipov = (struct ipovly *)ip; 788 bzero(ipov->ih_x1, sizeof ipov->ih_x1); 789 ipov->ih_len = htons((u_int16_t)tlen); 790 791 th->th_sum = 0; 792 th->th_sum = in_cksum(m, hlen + tlen); 793 ip->ip_len = htons(hlen + tlen); 794 ip->ip_ttl = ip_defttl; 795 break; 796 } 797 #endif 798 #ifdef INET6 799 case AF_INET6: 800 { 801 th->th_sum = 0; 802 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr), 803 tlen); 804 ip6->ip6_plen = ntohs(tlen); 805 if (tp && tp->t_in6pcb) { 806 struct ifnet *oifp; 807 ro = (struct route *)&tp->t_in6pcb->in6p_route; 808 oifp = ro->ro_rt ? ro->ro_rt->rt_ifp : NULL; 809 ip6->ip6_hlim = in6_selecthlim(tp->t_in6pcb, oifp); 810 } else 811 ip6->ip6_hlim = ip6_defhlim; 812 ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK; 813 if (ip6_auto_flowlabel) { 814 ip6->ip6_flow |= 815 (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK); 816 } 817 break; 818 } 819 #endif 820 } 821 822 if (tp && tp->t_inpcb) 823 so = tp->t_inpcb->inp_socket; 824 #ifdef INET6 825 else if (tp && tp->t_in6pcb) 826 so = tp->t_in6pcb->in6p_socket; 827 #endif 828 else 829 so = NULL; 830 831 if (tp != NULL && tp->t_inpcb != NULL) { 832 ro = &tp->t_inpcb->inp_route; 833 #ifdef DIAGNOSTIC 834 if (family != AF_INET) 835 panic("tcp_respond: address family mismatch"); 836 if (!in_hosteq(ip->ip_dst, tp->t_inpcb->inp_faddr)) { 837 panic("tcp_respond: ip_dst %x != inp_faddr %x", 838 ntohl(ip->ip_dst.s_addr), 839 ntohl(tp->t_inpcb->inp_faddr.s_addr)); 840 } 841 #endif 842 } 843 #ifdef INET6 844 else if (tp != NULL && tp->t_in6pcb != NULL) { 845 ro = (struct route *)&tp->t_in6pcb->in6p_route; 846 #ifdef DIAGNOSTIC 847 if (family == AF_INET) { 848 if (!IN6_IS_ADDR_V4MAPPED(&tp->t_in6pcb->in6p_faddr)) 849 panic("tcp_respond: not mapped addr"); 850 if (bcmp(&ip->ip_dst, 851 &tp->t_in6pcb->in6p_faddr.s6_addr32[3], 852 sizeof(ip->ip_dst)) != 0) { 853 panic("tcp_respond: ip_dst != in6p_faddr"); 854 } 855 } else if (family == AF_INET6) { 856 if (!IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 857 &tp->t_in6pcb->in6p_faddr)) 858 panic("tcp_respond: ip6_dst != in6p_faddr"); 859 } else 860 panic("tcp_respond: address family mismatch"); 861 #endif 862 } 863 #endif 864 else 865 ro = NULL; 866 867 switch (family) { 868 #ifdef INET 869 case AF_INET: 870 error = ip_output(m, NULL, ro, 871 (tp && tp->t_mtudisc ? IP_MTUDISC : 0), 872 (struct ip_moptions *)0, so); 873 break; 874 #endif 875 #ifdef INET6 876 case AF_INET6: 877 error = ip6_output(m, NULL, (struct route_in6 *)ro, 0, 878 (struct ip6_moptions *)0, so, NULL); 879 break; 880 #endif 881 default: 882 error = EAFNOSUPPORT; 883 break; 884 } 885 886 return (error); 887 } 888 889 /* 890 * Template TCPCB. Rather than zeroing a new TCPCB and initializing 891 * a bunch of members individually, we maintain this template for the 892 * static and mostly-static components of the TCPCB, and copy it into 893 * the new TCPCB instead. 894 */ 895 static struct tcpcb tcpcb_template = { 896 /* 897 * If TCP_NTIMERS ever changes, we'll need to update this 898 * initializer. 899 */ 900 .t_timer = { 901 CALLOUT_INITIALIZER, 902 CALLOUT_INITIALIZER, 903 CALLOUT_INITIALIZER, 904 CALLOUT_INITIALIZER, 905 }, 906 .t_delack_ch = CALLOUT_INITIALIZER, 907 908 .t_srtt = TCPTV_SRTTBASE, 909 .t_rttmin = TCPTV_MIN, 910 911 .snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT, 912 .snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT, 913 }; 914 915 /* 916 * Updates the TCPCB template whenever a parameter that would affect 917 * the template is changed. 918 */ 919 void 920 tcp_tcpcb_template(void) 921 { 922 struct tcpcb *tp = &tcpcb_template; 923 int flags; 924 925 tp->t_peermss = tcp_mssdflt; 926 tp->t_ourmss = tcp_mssdflt; 927 tp->t_segsz = tcp_mssdflt; 928 929 flags = 0; 930 if (tcp_do_rfc1323 && tcp_do_win_scale) 931 flags |= TF_REQ_SCALE; 932 if (tcp_do_rfc1323 && tcp_do_timestamps) 933 flags |= TF_REQ_TSTMP; 934 if (tcp_do_sack == 2) 935 flags |= TF_WILL_SACK; 936 else if (tcp_do_sack == 1) 937 flags |= TF_WILL_SACK|TF_IGNR_RXSACK; 938 flags |= TF_CANT_TXSACK; 939 tp->t_flags = flags; 940 941 /* 942 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 943 * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives 944 * reasonable initial retransmit time. 945 */ 946 tp->t_rttvar = tcp_rttdflt * PR_SLOWHZ << (TCP_RTTVAR_SHIFT + 2 - 1); 947 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), 948 TCPTV_MIN, TCPTV_REXMTMAX); 949 } 950 951 /* 952 * Create a new TCP control block, making an 953 * empty reassembly queue and hooking it to the argument 954 * protocol control block. 955 */ 956 struct tcpcb * 957 tcp_newtcpcb(family, aux) 958 int family; /* selects inpcb, or in6pcb */ 959 void *aux; 960 { 961 struct tcpcb *tp; 962 int i; 963 964 /* XXX Consider using a pool_cache for speed. */ 965 tp = pool_get(&tcpcb_pool, PR_NOWAIT); 966 if (tp == NULL) 967 return (NULL); 968 memcpy(tp, &tcpcb_template, sizeof(*tp)); 969 TAILQ_INIT(&tp->segq); 970 TAILQ_INIT(&tp->timeq); 971 tp->t_family = family; /* may be overridden later on */ 972 LIST_INIT(&tp->t_sc); /* XXX can template this */ 973 974 /* Don't sweat this loop; hopefully the compiler will unroll it. */ 975 for (i = 0; i < TCPT_NTIMERS; i++) 976 TCP_TIMER_INIT(tp, i); 977 978 switch (family) { 979 case AF_INET: 980 { 981 struct inpcb *inp = (struct inpcb *)aux; 982 983 inp->inp_ip.ip_ttl = ip_defttl; 984 inp->inp_ppcb = (caddr_t)tp; 985 986 tp->t_inpcb = inp; 987 tp->t_mtudisc = ip_mtudisc; 988 break; 989 } 990 #ifdef INET6 991 case AF_INET6: 992 { 993 struct in6pcb *in6p = (struct in6pcb *)aux; 994 995 in6p->in6p_ip6.ip6_hlim = in6_selecthlim(in6p, 996 in6p->in6p_route.ro_rt ? in6p->in6p_route.ro_rt->rt_ifp 997 : NULL); 998 in6p->in6p_ppcb = (caddr_t)tp; 999 1000 tp->t_in6pcb = in6p; 1001 /* for IPv6, always try to run path MTU discovery */ 1002 tp->t_mtudisc = 1; 1003 break; 1004 } 1005 #endif /* INET6 */ 1006 default: 1007 pool_put(&tcpcb_pool, tp); 1008 return (NULL); 1009 } 1010 1011 /* 1012 * Initialize our timebase. When we send timestamps, we take 1013 * the delta from tcp_now -- this means each connection always 1014 * gets a timebase of 0, which makes it, among other things, 1015 * more difficult to determine how long a system has been up, 1016 * and thus how many TCP sequence increments have occurred. 1017 */ 1018 tp->ts_timebase = tcp_now; 1019 1020 return (tp); 1021 } 1022 1023 /* 1024 * Drop a TCP connection, reporting 1025 * the specified error. If connection is synchronized, 1026 * then send a RST to peer. 1027 */ 1028 struct tcpcb * 1029 tcp_drop(tp, errno) 1030 struct tcpcb *tp; 1031 int errno; 1032 { 1033 struct socket *so = NULL; 1034 1035 #ifdef DIAGNOSTIC 1036 if (tp->t_inpcb && tp->t_in6pcb) 1037 panic("tcp_drop: both t_inpcb and t_in6pcb are set"); 1038 #endif 1039 #ifdef INET 1040 if (tp->t_inpcb) 1041 so = tp->t_inpcb->inp_socket; 1042 #endif 1043 #ifdef INET6 1044 if (tp->t_in6pcb) 1045 so = tp->t_in6pcb->in6p_socket; 1046 #endif 1047 if (!so) 1048 return NULL; 1049 1050 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1051 tp->t_state = TCPS_CLOSED; 1052 (void) tcp_output(tp); 1053 tcpstat.tcps_drops++; 1054 } else 1055 tcpstat.tcps_conndrops++; 1056 if (errno == ETIMEDOUT && tp->t_softerror) 1057 errno = tp->t_softerror; 1058 so->so_error = errno; 1059 return (tcp_close(tp)); 1060 } 1061 1062 /* 1063 * Return whether this tcpcb is marked as dead, indicating 1064 * to the calling timer function that no further action should 1065 * be taken, as we are about to release this tcpcb. The release 1066 * of the storage will be done if this is the last timer running. 1067 * 1068 * This should be called from the callout handler function after 1069 * callout_ack() is done, so that the number of invoking timer 1070 * functions is 0. 1071 */ 1072 int 1073 tcp_isdead(tp) 1074 struct tcpcb *tp; 1075 { 1076 int dead = (tp->t_flags & TF_DEAD); 1077 1078 if (__predict_false(dead)) { 1079 if (tcp_timers_invoking(tp) > 0) 1080 /* not quite there yet -- count separately? */ 1081 return dead; 1082 tcpstat.tcps_delayed_free++; 1083 pool_put(&tcpcb_pool, tp); 1084 } 1085 return dead; 1086 } 1087 1088 /* 1089 * Close a TCP control block: 1090 * discard all space held by the tcp 1091 * discard internet protocol block 1092 * wake up any sleepers 1093 */ 1094 struct tcpcb * 1095 tcp_close(tp) 1096 struct tcpcb *tp; 1097 { 1098 struct inpcb *inp; 1099 #ifdef INET6 1100 struct in6pcb *in6p; 1101 #endif 1102 struct socket *so; 1103 #ifdef RTV_RTT 1104 struct rtentry *rt; 1105 #endif 1106 struct route *ro; 1107 1108 inp = tp->t_inpcb; 1109 #ifdef INET6 1110 in6p = tp->t_in6pcb; 1111 #endif 1112 so = NULL; 1113 ro = NULL; 1114 if (inp) { 1115 so = inp->inp_socket; 1116 ro = &inp->inp_route; 1117 } 1118 #ifdef INET6 1119 else if (in6p) { 1120 so = in6p->in6p_socket; 1121 ro = (struct route *)&in6p->in6p_route; 1122 } 1123 #endif 1124 1125 #ifdef RTV_RTT 1126 /* 1127 * If we sent enough data to get some meaningful characteristics, 1128 * save them in the routing entry. 'Enough' is arbitrarily 1129 * defined as the sendpipesize (default 4K) * 16. This would 1130 * give us 16 rtt samples assuming we only get one sample per 1131 * window (the usual case on a long haul net). 16 samples is 1132 * enough for the srtt filter to converge to within 5% of the correct 1133 * value; fewer samples and we could save a very bogus rtt. 1134 * 1135 * Don't update the default route's characteristics and don't 1136 * update anything that the user "locked". 1137 */ 1138 if (SEQ_LT(tp->iss + so->so_snd.sb_hiwat * 16, tp->snd_max) && 1139 ro && (rt = ro->ro_rt) && 1140 !in_nullhost(satosin(rt_key(rt))->sin_addr)) { 1141 u_long i = 0; 1142 1143 if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) { 1144 i = tp->t_srtt * 1145 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 1146 if (rt->rt_rmx.rmx_rtt && i) 1147 /* 1148 * filter this update to half the old & half 1149 * the new values, converting scale. 1150 * See route.h and tcp_var.h for a 1151 * description of the scaling constants. 1152 */ 1153 rt->rt_rmx.rmx_rtt = 1154 (rt->rt_rmx.rmx_rtt + i) / 2; 1155 else 1156 rt->rt_rmx.rmx_rtt = i; 1157 } 1158 if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) { 1159 i = tp->t_rttvar * 1160 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTTVAR_SHIFT + 2)); 1161 if (rt->rt_rmx.rmx_rttvar && i) 1162 rt->rt_rmx.rmx_rttvar = 1163 (rt->rt_rmx.rmx_rttvar + i) / 2; 1164 else 1165 rt->rt_rmx.rmx_rttvar = i; 1166 } 1167 /* 1168 * update the pipelimit (ssthresh) if it has been updated 1169 * already or if a pipesize was specified & the threshhold 1170 * got below half the pipesize. I.e., wait for bad news 1171 * before we start updating, then update on both good 1172 * and bad news. 1173 */ 1174 if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 && 1175 (i = tp->snd_ssthresh) && rt->rt_rmx.rmx_ssthresh) || 1176 i < (rt->rt_rmx.rmx_sendpipe / 2)) { 1177 /* 1178 * convert the limit from user data bytes to 1179 * packets then to packet data bytes. 1180 */ 1181 i = (i + tp->t_segsz / 2) / tp->t_segsz; 1182 if (i < 2) 1183 i = 2; 1184 i *= (u_long)(tp->t_segsz + sizeof (struct tcpiphdr)); 1185 if (rt->rt_rmx.rmx_ssthresh) 1186 rt->rt_rmx.rmx_ssthresh = 1187 (rt->rt_rmx.rmx_ssthresh + i) / 2; 1188 else 1189 rt->rt_rmx.rmx_ssthresh = i; 1190 } 1191 } 1192 #endif /* RTV_RTT */ 1193 /* free the reassembly queue, if any */ 1194 TCP_REASS_LOCK(tp); 1195 (void) tcp_freeq(tp); 1196 TCP_REASS_UNLOCK(tp); 1197 1198 tcp_canceltimers(tp); 1199 TCP_CLEAR_DELACK(tp); 1200 syn_cache_cleanup(tp); 1201 1202 if (tp->t_template) { 1203 m_free(tp->t_template); 1204 tp->t_template = NULL; 1205 } 1206 if (tcp_timers_invoking(tp)) 1207 tp->t_flags |= TF_DEAD; 1208 else 1209 pool_put(&tcpcb_pool, tp); 1210 1211 if (inp) { 1212 inp->inp_ppcb = 0; 1213 soisdisconnected(so); 1214 in_pcbdetach(inp); 1215 } 1216 #ifdef INET6 1217 else if (in6p) { 1218 in6p->in6p_ppcb = 0; 1219 soisdisconnected(so); 1220 in6_pcbdetach(in6p); 1221 } 1222 #endif 1223 tcpstat.tcps_closed++; 1224 return ((struct tcpcb *)0); 1225 } 1226 1227 int 1228 tcp_freeq(tp) 1229 struct tcpcb *tp; 1230 { 1231 struct ipqent *qe; 1232 int rv = 0; 1233 #ifdef TCPREASS_DEBUG 1234 int i = 0; 1235 #endif 1236 1237 TCP_REASS_LOCK_CHECK(tp); 1238 1239 while ((qe = TAILQ_FIRST(&tp->segq)) != NULL) { 1240 #ifdef TCPREASS_DEBUG 1241 printf("tcp_freeq[%p,%d]: %u:%u(%u) 0x%02x\n", 1242 tp, i++, qe->ipqe_seq, qe->ipqe_seq + qe->ipqe_len, 1243 qe->ipqe_len, qe->ipqe_flags & (TH_SYN|TH_FIN|TH_RST)); 1244 #endif 1245 TAILQ_REMOVE(&tp->segq, qe, ipqe_q); 1246 TAILQ_REMOVE(&tp->timeq, qe, ipqe_timeq); 1247 m_freem(qe->ipqe_m); 1248 pool_put(&tcpipqent_pool, qe); 1249 rv = 1; 1250 } 1251 return (rv); 1252 } 1253 1254 /* 1255 * Protocol drain routine. Called when memory is in short supply. 1256 */ 1257 void 1258 tcp_drain() 1259 { 1260 struct inpcb_hdr *inph; 1261 struct tcpcb *tp; 1262 1263 /* 1264 * Free the sequence queue of all TCP connections. 1265 */ 1266 CIRCLEQ_FOREACH(inph, &tcbtable.inpt_queue, inph_queue) { 1267 switch (inph->inph_af) { 1268 case AF_INET: 1269 tp = intotcpcb((struct inpcb *)inph); 1270 break; 1271 #ifdef INET6 1272 case AF_INET6: 1273 tp = in6totcpcb((struct in6pcb *)inph); 1274 break; 1275 #endif 1276 default: 1277 tp = NULL; 1278 break; 1279 } 1280 if (tp != NULL) { 1281 /* 1282 * We may be called from a device's interrupt 1283 * context. If the tcpcb is already busy, 1284 * just bail out now. 1285 */ 1286 if (tcp_reass_lock_try(tp) == 0) 1287 continue; 1288 if (tcp_freeq(tp)) 1289 tcpstat.tcps_connsdrained++; 1290 TCP_REASS_UNLOCK(tp); 1291 } 1292 } 1293 } 1294 1295 /* 1296 * Notify a tcp user of an asynchronous error; 1297 * store error as soft error, but wake up user 1298 * (for now, won't do anything until can select for soft error). 1299 */ 1300 void 1301 tcp_notify(inp, error) 1302 struct inpcb *inp; 1303 int error; 1304 { 1305 struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb; 1306 struct socket *so = inp->inp_socket; 1307 1308 /* 1309 * Ignore some errors if we are hooked up. 1310 * If connection hasn't completed, has retransmitted several times, 1311 * and receives a second error, give up now. This is better 1312 * than waiting a long time to establish a connection that 1313 * can never complete. 1314 */ 1315 if (tp->t_state == TCPS_ESTABLISHED && 1316 (error == EHOSTUNREACH || error == ENETUNREACH || 1317 error == EHOSTDOWN)) { 1318 return; 1319 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1320 tp->t_rxtshift > 3 && tp->t_softerror) 1321 so->so_error = error; 1322 else 1323 tp->t_softerror = error; 1324 wakeup((caddr_t) &so->so_timeo); 1325 sorwakeup(so); 1326 sowwakeup(so); 1327 } 1328 1329 #ifdef INET6 1330 void 1331 tcp6_notify(in6p, error) 1332 struct in6pcb *in6p; 1333 int error; 1334 { 1335 struct tcpcb *tp = (struct tcpcb *)in6p->in6p_ppcb; 1336 struct socket *so = in6p->in6p_socket; 1337 1338 /* 1339 * Ignore some errors if we are hooked up. 1340 * If connection hasn't completed, has retransmitted several times, 1341 * and receives a second error, give up now. This is better 1342 * than waiting a long time to establish a connection that 1343 * can never complete. 1344 */ 1345 if (tp->t_state == TCPS_ESTABLISHED && 1346 (error == EHOSTUNREACH || error == ENETUNREACH || 1347 error == EHOSTDOWN)) { 1348 return; 1349 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1350 tp->t_rxtshift > 3 && tp->t_softerror) 1351 so->so_error = error; 1352 else 1353 tp->t_softerror = error; 1354 wakeup((caddr_t) &so->so_timeo); 1355 sorwakeup(so); 1356 sowwakeup(so); 1357 } 1358 #endif 1359 1360 #ifdef INET6 1361 void 1362 tcp6_ctlinput(cmd, sa, d) 1363 int cmd; 1364 struct sockaddr *sa; 1365 void *d; 1366 { 1367 struct tcphdr th; 1368 void (*notify) __P((struct in6pcb *, int)) = tcp6_notify; 1369 int nmatch; 1370 struct ip6_hdr *ip6; 1371 const struct sockaddr_in6 *sa6_src = NULL; 1372 struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)sa; 1373 struct mbuf *m; 1374 int off; 1375 1376 if (sa->sa_family != AF_INET6 || 1377 sa->sa_len != sizeof(struct sockaddr_in6)) 1378 return; 1379 if ((unsigned)cmd >= PRC_NCMDS) 1380 return; 1381 else if (cmd == PRC_QUENCH) { 1382 /* XXX there's no PRC_QUENCH in IPv6 */ 1383 notify = tcp6_quench; 1384 } else if (PRC_IS_REDIRECT(cmd)) 1385 notify = in6_rtchange, d = NULL; 1386 else if (cmd == PRC_MSGSIZE) 1387 ; /* special code is present, see below */ 1388 else if (cmd == PRC_HOSTDEAD) 1389 d = NULL; 1390 else if (inet6ctlerrmap[cmd] == 0) 1391 return; 1392 1393 /* if the parameter is from icmp6, decode it. */ 1394 if (d != NULL) { 1395 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 1396 m = ip6cp->ip6c_m; 1397 ip6 = ip6cp->ip6c_ip6; 1398 off = ip6cp->ip6c_off; 1399 sa6_src = ip6cp->ip6c_src; 1400 } else { 1401 m = NULL; 1402 ip6 = NULL; 1403 sa6_src = &sa6_any; 1404 off = 0; 1405 } 1406 1407 if (ip6) { 1408 /* 1409 * XXX: We assume that when ip6 is non NULL, 1410 * M and OFF are valid. 1411 */ 1412 1413 /* check if we can safely examine src and dst ports */ 1414 if (m->m_pkthdr.len < off + sizeof(th)) { 1415 if (cmd == PRC_MSGSIZE) 1416 icmp6_mtudisc_update((struct ip6ctlparam *)d, 0); 1417 return; 1418 } 1419 1420 bzero(&th, sizeof(th)); 1421 m_copydata(m, off, sizeof(th), (caddr_t)&th); 1422 1423 if (cmd == PRC_MSGSIZE) { 1424 int valid = 0; 1425 1426 /* 1427 * Check to see if we have a valid TCP connection 1428 * corresponding to the address in the ICMPv6 message 1429 * payload. 1430 */ 1431 if (in6_pcblookup_connect(&tcbtable, &sa6->sin6_addr, 1432 th.th_dport, (struct in6_addr *)&sa6_src->sin6_addr, 1433 th.th_sport, 0)) 1434 valid++; 1435 1436 /* 1437 * Depending on the value of "valid" and routing table 1438 * size (mtudisc_{hi,lo}wat), we will: 1439 * - recalcurate the new MTU and create the 1440 * corresponding routing entry, or 1441 * - ignore the MTU change notification. 1442 */ 1443 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid); 1444 1445 /* 1446 * no need to call in6_pcbnotify, it should have been 1447 * called via callback if necessary 1448 */ 1449 return; 1450 } 1451 1452 nmatch = in6_pcbnotify(&tcbtable, sa, th.th_dport, 1453 (struct sockaddr *)sa6_src, th.th_sport, cmd, NULL, notify); 1454 if (nmatch == 0 && syn_cache_count && 1455 (inet6ctlerrmap[cmd] == EHOSTUNREACH || 1456 inet6ctlerrmap[cmd] == ENETUNREACH || 1457 inet6ctlerrmap[cmd] == EHOSTDOWN)) 1458 syn_cache_unreach((struct sockaddr *)sa6_src, 1459 sa, &th); 1460 } else { 1461 (void) in6_pcbnotify(&tcbtable, sa, 0, 1462 (struct sockaddr *)sa6_src, 0, cmd, NULL, notify); 1463 } 1464 } 1465 #endif 1466 1467 #ifdef INET 1468 /* assumes that ip header and tcp header are contiguous on mbuf */ 1469 void * 1470 tcp_ctlinput(cmd, sa, v) 1471 int cmd; 1472 struct sockaddr *sa; 1473 void *v; 1474 { 1475 struct ip *ip = v; 1476 struct tcphdr *th; 1477 struct icmp *icp; 1478 extern const int inetctlerrmap[]; 1479 void (*notify) __P((struct inpcb *, int)) = tcp_notify; 1480 int errno; 1481 int nmatch; 1482 #ifdef INET6 1483 struct in6_addr src6, dst6; 1484 #endif 1485 1486 if (sa->sa_family != AF_INET || 1487 sa->sa_len != sizeof(struct sockaddr_in)) 1488 return NULL; 1489 if ((unsigned)cmd >= PRC_NCMDS) 1490 return NULL; 1491 errno = inetctlerrmap[cmd]; 1492 if (cmd == PRC_QUENCH) 1493 notify = tcp_quench; 1494 else if (PRC_IS_REDIRECT(cmd)) 1495 notify = in_rtchange, ip = 0; 1496 else if (cmd == PRC_MSGSIZE && ip && ip->ip_v == 4) { 1497 /* 1498 * Check to see if we have a valid TCP connection 1499 * corresponding to the address in the ICMP message 1500 * payload. 1501 * 1502 * Boundary check is made in icmp_input(), with ICMP_ADVLENMIN. 1503 */ 1504 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1505 #ifdef INET6 1506 memset(&src6, 0, sizeof(src6)); 1507 memset(&dst6, 0, sizeof(dst6)); 1508 src6.s6_addr16[5] = dst6.s6_addr16[5] = 0xffff; 1509 memcpy(&src6.s6_addr32[3], &ip->ip_src, sizeof(struct in_addr)); 1510 memcpy(&dst6.s6_addr32[3], &ip->ip_dst, sizeof(struct in_addr)); 1511 #endif 1512 if (in_pcblookup_connect(&tcbtable, ip->ip_dst, th->th_dport, 1513 ip->ip_src, th->th_sport) != NULL) 1514 ; 1515 #ifdef INET6 1516 else if (in6_pcblookup_connect(&tcbtable, &dst6, 1517 th->th_dport, &src6, th->th_sport, 0) != NULL) 1518 ; 1519 #endif 1520 else 1521 return NULL; 1522 1523 /* 1524 * Now that we've validated that we are actually communicating 1525 * with the host indicated in the ICMP message, locate the 1526 * ICMP header, recalculate the new MTU, and create the 1527 * corresponding routing entry. 1528 */ 1529 icp = (struct icmp *)((caddr_t)ip - 1530 offsetof(struct icmp, icmp_ip)); 1531 icmp_mtudisc(icp, ip->ip_dst); 1532 1533 return NULL; 1534 } else if (cmd == PRC_HOSTDEAD) 1535 ip = 0; 1536 else if (errno == 0) 1537 return NULL; 1538 if (ip && ip->ip_v == 4 && sa->sa_family == AF_INET) { 1539 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1540 nmatch = in_pcbnotify(&tcbtable, satosin(sa)->sin_addr, 1541 th->th_dport, ip->ip_src, th->th_sport, errno, notify); 1542 if (nmatch == 0 && syn_cache_count && 1543 (inetctlerrmap[cmd] == EHOSTUNREACH || 1544 inetctlerrmap[cmd] == ENETUNREACH || 1545 inetctlerrmap[cmd] == EHOSTDOWN)) { 1546 struct sockaddr_in sin; 1547 bzero(&sin, sizeof(sin)); 1548 sin.sin_len = sizeof(sin); 1549 sin.sin_family = AF_INET; 1550 sin.sin_port = th->th_sport; 1551 sin.sin_addr = ip->ip_src; 1552 syn_cache_unreach((struct sockaddr *)&sin, sa, th); 1553 } 1554 1555 /* XXX mapped address case */ 1556 } else 1557 in_pcbnotifyall(&tcbtable, satosin(sa)->sin_addr, errno, 1558 notify); 1559 return NULL; 1560 } 1561 1562 /* 1563 * When a source quence is received, we are being notifed of congestion. 1564 * Close the congestion window down to the Loss Window (one segment). 1565 * We will gradually open it again as we proceed. 1566 */ 1567 void 1568 tcp_quench(inp, errno) 1569 struct inpcb *inp; 1570 int errno; 1571 { 1572 struct tcpcb *tp = intotcpcb(inp); 1573 1574 if (tp) 1575 tp->snd_cwnd = tp->t_segsz; 1576 } 1577 #endif 1578 1579 #ifdef INET6 1580 void 1581 tcp6_quench(in6p, errno) 1582 struct in6pcb *in6p; 1583 int errno; 1584 { 1585 struct tcpcb *tp = in6totcpcb(in6p); 1586 1587 if (tp) 1588 tp->snd_cwnd = tp->t_segsz; 1589 } 1590 #endif 1591 1592 #ifdef INET 1593 /* 1594 * Path MTU Discovery handlers. 1595 */ 1596 void 1597 tcp_mtudisc_callback(faddr) 1598 struct in_addr faddr; 1599 { 1600 #ifdef INET6 1601 struct in6_addr in6; 1602 #endif 1603 1604 in_pcbnotifyall(&tcbtable, faddr, EMSGSIZE, tcp_mtudisc); 1605 #ifdef INET6 1606 memset(&in6, 0, sizeof(in6)); 1607 in6.s6_addr16[5] = 0xffff; 1608 memcpy(&in6.s6_addr32[3], &faddr, sizeof(struct in_addr)); 1609 tcp6_mtudisc_callback(&in6); 1610 #endif 1611 } 1612 1613 /* 1614 * On receipt of path MTU corrections, flush old route and replace it 1615 * with the new one. Retransmit all unacknowledged packets, to ensure 1616 * that all packets will be received. 1617 */ 1618 void 1619 tcp_mtudisc(inp, errno) 1620 struct inpcb *inp; 1621 int errno; 1622 { 1623 struct tcpcb *tp = intotcpcb(inp); 1624 struct rtentry *rt = in_pcbrtentry(inp); 1625 1626 if (tp != 0) { 1627 if (rt != 0) { 1628 /* 1629 * If this was not a host route, remove and realloc. 1630 */ 1631 if ((rt->rt_flags & RTF_HOST) == 0) { 1632 in_rtchange(inp, errno); 1633 if ((rt = in_pcbrtentry(inp)) == 0) 1634 return; 1635 } 1636 1637 /* 1638 * Slow start out of the error condition. We 1639 * use the MTU because we know it's smaller 1640 * than the previously transmitted segment. 1641 * 1642 * Note: This is more conservative than the 1643 * suggestion in draft-floyd-incr-init-win-03. 1644 */ 1645 if (rt->rt_rmx.rmx_mtu != 0) 1646 tp->snd_cwnd = 1647 TCP_INITIAL_WINDOW(tcp_init_win, 1648 rt->rt_rmx.rmx_mtu); 1649 } 1650 1651 /* 1652 * Resend unacknowledged packets. 1653 */ 1654 tp->snd_nxt = tp->snd_una; 1655 tcp_output(tp); 1656 } 1657 } 1658 #endif 1659 1660 #ifdef INET6 1661 /* 1662 * Path MTU Discovery handlers. 1663 */ 1664 void 1665 tcp6_mtudisc_callback(faddr) 1666 struct in6_addr *faddr; 1667 { 1668 struct sockaddr_in6 sin6; 1669 1670 bzero(&sin6, sizeof(sin6)); 1671 sin6.sin6_family = AF_INET6; 1672 sin6.sin6_len = sizeof(struct sockaddr_in6); 1673 sin6.sin6_addr = *faddr; 1674 (void) in6_pcbnotify(&tcbtable, (struct sockaddr *)&sin6, 0, 1675 (struct sockaddr *)&sa6_any, 0, PRC_MSGSIZE, NULL, tcp6_mtudisc); 1676 } 1677 1678 void 1679 tcp6_mtudisc(in6p, errno) 1680 struct in6pcb *in6p; 1681 int errno; 1682 { 1683 struct tcpcb *tp = in6totcpcb(in6p); 1684 struct rtentry *rt = in6_pcbrtentry(in6p); 1685 1686 if (tp != 0) { 1687 if (rt != 0) { 1688 /* 1689 * If this was not a host route, remove and realloc. 1690 */ 1691 if ((rt->rt_flags & RTF_HOST) == 0) { 1692 in6_rtchange(in6p, errno); 1693 if ((rt = in6_pcbrtentry(in6p)) == 0) 1694 return; 1695 } 1696 1697 /* 1698 * Slow start out of the error condition. We 1699 * use the MTU because we know it's smaller 1700 * than the previously transmitted segment. 1701 * 1702 * Note: This is more conservative than the 1703 * suggestion in draft-floyd-incr-init-win-03. 1704 */ 1705 if (rt->rt_rmx.rmx_mtu != 0) 1706 tp->snd_cwnd = 1707 TCP_INITIAL_WINDOW(tcp_init_win, 1708 rt->rt_rmx.rmx_mtu); 1709 } 1710 1711 /* 1712 * Resend unacknowledged packets. 1713 */ 1714 tp->snd_nxt = tp->snd_una; 1715 tcp_output(tp); 1716 } 1717 } 1718 #endif /* INET6 */ 1719 1720 /* 1721 * Compute the MSS to advertise to the peer. Called only during 1722 * the 3-way handshake. If we are the server (peer initiated 1723 * connection), we are called with a pointer to the interface 1724 * on which the SYN packet arrived. If we are the client (we 1725 * initiated connection), we are called with a pointer to the 1726 * interface out which this connection should go. 1727 * 1728 * NOTE: Do not subtract IP option/extension header size nor IPsec 1729 * header size from MSS advertisement. MSS option must hold the maximum 1730 * segment size we can accept, so it must always be: 1731 * max(if mtu) - ip header - tcp header 1732 */ 1733 u_long 1734 tcp_mss_to_advertise(ifp, af) 1735 const struct ifnet *ifp; 1736 int af; 1737 { 1738 extern u_long in_maxmtu; 1739 u_long mss = 0; 1740 u_long hdrsiz; 1741 1742 /* 1743 * In order to avoid defeating path MTU discovery on the peer, 1744 * we advertise the max MTU of all attached networks as our MSS, 1745 * per RFC 1191, section 3.1. 1746 * 1747 * We provide the option to advertise just the MTU of 1748 * the interface on which we hope this connection will 1749 * be receiving. If we are responding to a SYN, we 1750 * will have a pretty good idea about this, but when 1751 * initiating a connection there is a bit more doubt. 1752 * 1753 * We also need to ensure that loopback has a large enough 1754 * MSS, as the loopback MTU is never included in in_maxmtu. 1755 */ 1756 1757 if (ifp != NULL) 1758 switch (af) { 1759 case AF_INET: 1760 mss = ifp->if_mtu; 1761 break; 1762 #ifdef INET6 1763 case AF_INET6: 1764 mss = IN6_LINKMTU(ifp); 1765 break; 1766 #endif 1767 } 1768 1769 if (tcp_mss_ifmtu == 0) 1770 switch (af) { 1771 case AF_INET: 1772 mss = max(in_maxmtu, mss); 1773 break; 1774 #ifdef INET6 1775 case AF_INET6: 1776 mss = max(in6_maxmtu, mss); 1777 break; 1778 #endif 1779 } 1780 1781 switch (af) { 1782 case AF_INET: 1783 hdrsiz = sizeof(struct ip); 1784 break; 1785 #ifdef INET6 1786 case AF_INET6: 1787 hdrsiz = sizeof(struct ip6_hdr); 1788 break; 1789 #endif 1790 default: 1791 hdrsiz = 0; 1792 break; 1793 } 1794 hdrsiz += sizeof(struct tcphdr); 1795 if (mss > hdrsiz) 1796 mss -= hdrsiz; 1797 1798 mss = max(tcp_mssdflt, mss); 1799 return (mss); 1800 } 1801 1802 /* 1803 * Set connection variables based on the peer's advertised MSS. 1804 * We are passed the TCPCB for the actual connection. If we 1805 * are the server, we are called by the compressed state engine 1806 * when the 3-way handshake is complete. If we are the client, 1807 * we are called when we receive the SYN,ACK from the server. 1808 * 1809 * NOTE: Our advertised MSS value must be initialized in the TCPCB 1810 * before this routine is called! 1811 */ 1812 void 1813 tcp_mss_from_peer(tp, offer) 1814 struct tcpcb *tp; 1815 int offer; 1816 { 1817 struct socket *so; 1818 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1819 struct rtentry *rt; 1820 #endif 1821 u_long bufsize; 1822 int mss; 1823 1824 #ifdef DIAGNOSTIC 1825 if (tp->t_inpcb && tp->t_in6pcb) 1826 panic("tcp_mss_from_peer: both t_inpcb and t_in6pcb are set"); 1827 #endif 1828 so = NULL; 1829 rt = NULL; 1830 #ifdef INET 1831 if (tp->t_inpcb) { 1832 so = tp->t_inpcb->inp_socket; 1833 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1834 rt = in_pcbrtentry(tp->t_inpcb); 1835 #endif 1836 } 1837 #endif 1838 #ifdef INET6 1839 if (tp->t_in6pcb) { 1840 so = tp->t_in6pcb->in6p_socket; 1841 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1842 rt = in6_pcbrtentry(tp->t_in6pcb); 1843 #endif 1844 } 1845 #endif 1846 1847 /* 1848 * As per RFC1122, use the default MSS value, unless they 1849 * sent us an offer. Do not accept offers less than 256 bytes. 1850 */ 1851 mss = tcp_mssdflt; 1852 if (offer) 1853 mss = offer; 1854 mss = max(mss, 256); /* sanity */ 1855 tp->t_peermss = mss; 1856 mss -= tcp_optlen(tp); 1857 #ifdef INET 1858 if (tp->t_inpcb) 1859 mss -= ip_optlen(tp->t_inpcb); 1860 #endif 1861 #ifdef INET6 1862 if (tp->t_in6pcb) 1863 mss -= ip6_optlen(tp->t_in6pcb); 1864 #endif 1865 1866 /* 1867 * If there's a pipesize, change the socket buffer to that size. 1868 * Make the socket buffer an integral number of MSS units. If 1869 * the MSS is larger than the socket buffer, artificially decrease 1870 * the MSS. 1871 */ 1872 #ifdef RTV_SPIPE 1873 if (rt != NULL && rt->rt_rmx.rmx_sendpipe != 0) 1874 bufsize = rt->rt_rmx.rmx_sendpipe; 1875 else 1876 #endif 1877 bufsize = so->so_snd.sb_hiwat; 1878 if (bufsize < mss) 1879 mss = bufsize; 1880 else { 1881 bufsize = roundup(bufsize, mss); 1882 if (bufsize > sb_max) 1883 bufsize = sb_max; 1884 (void) sbreserve(&so->so_snd, bufsize, so); 1885 } 1886 tp->t_segsz = mss; 1887 1888 #ifdef RTV_SSTHRESH 1889 if (rt != NULL && rt->rt_rmx.rmx_ssthresh) { 1890 /* 1891 * There's some sort of gateway or interface buffer 1892 * limit on the path. Use this to set the slow 1893 * start threshold, but set the threshold to no less 1894 * than 2 * MSS. 1895 */ 1896 tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh); 1897 } 1898 #endif 1899 } 1900 1901 /* 1902 * Processing necessary when a TCP connection is established. 1903 */ 1904 void 1905 tcp_established(tp) 1906 struct tcpcb *tp; 1907 { 1908 struct socket *so; 1909 #ifdef RTV_RPIPE 1910 struct rtentry *rt; 1911 #endif 1912 u_long bufsize; 1913 1914 #ifdef DIAGNOSTIC 1915 if (tp->t_inpcb && tp->t_in6pcb) 1916 panic("tcp_established: both t_inpcb and t_in6pcb are set"); 1917 #endif 1918 so = NULL; 1919 rt = NULL; 1920 #ifdef INET 1921 if (tp->t_inpcb) { 1922 so = tp->t_inpcb->inp_socket; 1923 #if defined(RTV_RPIPE) 1924 rt = in_pcbrtentry(tp->t_inpcb); 1925 #endif 1926 } 1927 #endif 1928 #ifdef INET6 1929 if (tp->t_in6pcb) { 1930 so = tp->t_in6pcb->in6p_socket; 1931 #if defined(RTV_RPIPE) 1932 rt = in6_pcbrtentry(tp->t_in6pcb); 1933 #endif 1934 } 1935 #endif 1936 1937 tp->t_state = TCPS_ESTABLISHED; 1938 TCP_TIMER_ARM(tp, TCPT_KEEP, tcp_keepidle); 1939 1940 #ifdef RTV_RPIPE 1941 if (rt != NULL && rt->rt_rmx.rmx_recvpipe != 0) 1942 bufsize = rt->rt_rmx.rmx_recvpipe; 1943 else 1944 #endif 1945 bufsize = so->so_rcv.sb_hiwat; 1946 if (bufsize > tp->t_ourmss) { 1947 bufsize = roundup(bufsize, tp->t_ourmss); 1948 if (bufsize > sb_max) 1949 bufsize = sb_max; 1950 (void) sbreserve(&so->so_rcv, bufsize, so); 1951 } 1952 } 1953 1954 /* 1955 * Check if there's an initial rtt or rttvar. Convert from the 1956 * route-table units to scaled multiples of the slow timeout timer. 1957 * Called only during the 3-way handshake. 1958 */ 1959 void 1960 tcp_rmx_rtt(tp) 1961 struct tcpcb *tp; 1962 { 1963 #ifdef RTV_RTT 1964 struct rtentry *rt = NULL; 1965 int rtt; 1966 1967 #ifdef DIAGNOSTIC 1968 if (tp->t_inpcb && tp->t_in6pcb) 1969 panic("tcp_rmx_rtt: both t_inpcb and t_in6pcb are set"); 1970 #endif 1971 #ifdef INET 1972 if (tp->t_inpcb) 1973 rt = in_pcbrtentry(tp->t_inpcb); 1974 #endif 1975 #ifdef INET6 1976 if (tp->t_in6pcb) 1977 rt = in6_pcbrtentry(tp->t_in6pcb); 1978 #endif 1979 if (rt == NULL) 1980 return; 1981 1982 if (tp->t_srtt == 0 && (rtt = rt->rt_rmx.rmx_rtt)) { 1983 /* 1984 * XXX The lock bit for MTU indicates that the value 1985 * is also a minimum value; this is subject to time. 1986 */ 1987 if (rt->rt_rmx.rmx_locks & RTV_RTT) 1988 TCPT_RANGESET(tp->t_rttmin, 1989 rtt / (RTM_RTTUNIT / PR_SLOWHZ), 1990 TCPTV_MIN, TCPTV_REXMTMAX); 1991 tp->t_srtt = rtt / 1992 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 1993 if (rt->rt_rmx.rmx_rttvar) { 1994 tp->t_rttvar = rt->rt_rmx.rmx_rttvar / 1995 ((RTM_RTTUNIT / PR_SLOWHZ) >> 1996 (TCP_RTTVAR_SHIFT + 2)); 1997 } else { 1998 /* Default variation is +- 1 rtt */ 1999 tp->t_rttvar = 2000 tp->t_srtt >> (TCP_RTT_SHIFT - TCP_RTTVAR_SHIFT); 2001 } 2002 TCPT_RANGESET(tp->t_rxtcur, 2003 ((tp->t_srtt >> 2) + tp->t_rttvar) >> (1 + 2), 2004 tp->t_rttmin, TCPTV_REXMTMAX); 2005 } 2006 #endif 2007 } 2008 2009 tcp_seq tcp_iss_seq = 0; /* tcp initial seq # */ 2010 #if NRND > 0 2011 u_int8_t tcp_iss_secret[16]; /* 128 bits; should be plenty */ 2012 #endif 2013 2014 /* 2015 * Get a new sequence value given a tcp control block 2016 */ 2017 tcp_seq 2018 tcp_new_iss(struct tcpcb *tp, tcp_seq addin) 2019 { 2020 2021 #ifdef INET 2022 if (tp->t_inpcb != NULL) { 2023 return (tcp_new_iss1(&tp->t_inpcb->inp_laddr, 2024 &tp->t_inpcb->inp_faddr, tp->t_inpcb->inp_lport, 2025 tp->t_inpcb->inp_fport, sizeof(tp->t_inpcb->inp_laddr), 2026 addin)); 2027 } 2028 #endif 2029 #ifdef INET6 2030 if (tp->t_in6pcb != NULL) { 2031 return (tcp_new_iss1(&tp->t_in6pcb->in6p_laddr, 2032 &tp->t_in6pcb->in6p_faddr, tp->t_in6pcb->in6p_lport, 2033 tp->t_in6pcb->in6p_fport, sizeof(tp->t_in6pcb->in6p_laddr), 2034 addin)); 2035 } 2036 #endif 2037 /* Not possible. */ 2038 panic("tcp_new_iss"); 2039 } 2040 2041 /* 2042 * This routine actually generates a new TCP initial sequence number. 2043 */ 2044 tcp_seq 2045 tcp_new_iss1(void *laddr, void *faddr, u_int16_t lport, u_int16_t fport, 2046 size_t addrsz, tcp_seq addin) 2047 { 2048 tcp_seq tcp_iss; 2049 2050 #if NRND > 0 2051 static int beenhere; 2052 2053 /* 2054 * If we haven't been here before, initialize our cryptographic 2055 * hash secret. 2056 */ 2057 if (beenhere == 0) { 2058 rnd_extract_data(tcp_iss_secret, sizeof(tcp_iss_secret), 2059 RND_EXTRACT_ANY); 2060 beenhere = 1; 2061 } 2062 2063 if (tcp_do_rfc1948) { 2064 MD5_CTX ctx; 2065 u_int8_t hash[16]; /* XXX MD5 knowledge */ 2066 2067 /* 2068 * Compute the base value of the ISS. It is a hash 2069 * of (saddr, sport, daddr, dport, secret). 2070 */ 2071 MD5Init(&ctx); 2072 2073 MD5Update(&ctx, (u_char *) laddr, addrsz); 2074 MD5Update(&ctx, (u_char *) &lport, sizeof(lport)); 2075 2076 MD5Update(&ctx, (u_char *) faddr, addrsz); 2077 MD5Update(&ctx, (u_char *) &fport, sizeof(fport)); 2078 2079 MD5Update(&ctx, tcp_iss_secret, sizeof(tcp_iss_secret)); 2080 2081 MD5Final(hash, &ctx); 2082 2083 memcpy(&tcp_iss, hash, sizeof(tcp_iss)); 2084 2085 /* 2086 * Now increment our "timer", and add it in to 2087 * the computed value. 2088 * 2089 * XXX Use `addin'? 2090 * XXX TCP_ISSINCR too large to use? 2091 */ 2092 tcp_iss_seq += TCP_ISSINCR; 2093 #ifdef TCPISS_DEBUG 2094 printf("ISS hash 0x%08x, ", tcp_iss); 2095 #endif 2096 tcp_iss += tcp_iss_seq + addin; 2097 #ifdef TCPISS_DEBUG 2098 printf("new ISS 0x%08x\n", tcp_iss); 2099 #endif 2100 } else 2101 #endif /* NRND > 0 */ 2102 { 2103 /* 2104 * Randomize. 2105 */ 2106 #if NRND > 0 2107 rnd_extract_data(&tcp_iss, sizeof(tcp_iss), RND_EXTRACT_ANY); 2108 #else 2109 tcp_iss = arc4random(); 2110 #endif 2111 2112 /* 2113 * If we were asked to add some amount to a known value, 2114 * we will take a random value obtained above, mask off 2115 * the upper bits, and add in the known value. We also 2116 * add in a constant to ensure that we are at least a 2117 * certain distance from the original value. 2118 * 2119 * This is used when an old connection is in timed wait 2120 * and we have a new one coming in, for instance. 2121 */ 2122 if (addin != 0) { 2123 #ifdef TCPISS_DEBUG 2124 printf("Random %08x, ", tcp_iss); 2125 #endif 2126 tcp_iss &= TCP_ISS_RANDOM_MASK; 2127 tcp_iss += addin + TCP_ISSINCR; 2128 #ifdef TCPISS_DEBUG 2129 printf("Old ISS %08x, ISS %08x\n", addin, tcp_iss); 2130 #endif 2131 } else { 2132 tcp_iss &= TCP_ISS_RANDOM_MASK; 2133 tcp_iss += tcp_iss_seq; 2134 tcp_iss_seq += TCP_ISSINCR; 2135 #ifdef TCPISS_DEBUG 2136 printf("ISS %08x\n", tcp_iss); 2137 #endif 2138 } 2139 } 2140 2141 if (tcp_compat_42) { 2142 /* 2143 * Limit it to the positive range for really old TCP 2144 * implementations. 2145 * Just AND off the top bit instead of checking if 2146 * is set first - saves a branch 50% of the time. 2147 */ 2148 tcp_iss &= 0x7fffffff; /* XXX */ 2149 } 2150 2151 return (tcp_iss); 2152 } 2153 2154 #if defined(IPSEC) || defined(FAST_IPSEC) 2155 /* compute ESP/AH header size for TCP, including outer IP header. */ 2156 size_t 2157 ipsec4_hdrsiz_tcp(tp) 2158 struct tcpcb *tp; 2159 { 2160 struct inpcb *inp; 2161 size_t hdrsiz; 2162 2163 /* XXX mapped addr case (tp->t_in6pcb) */ 2164 if (!tp || !tp->t_template || !(inp = tp->t_inpcb)) 2165 return 0; 2166 switch (tp->t_family) { 2167 case AF_INET: 2168 /* XXX: should use currect direction. */ 2169 hdrsiz = ipsec4_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, inp); 2170 break; 2171 default: 2172 hdrsiz = 0; 2173 break; 2174 } 2175 2176 return hdrsiz; 2177 } 2178 2179 #ifdef INET6 2180 size_t 2181 ipsec6_hdrsiz_tcp(tp) 2182 struct tcpcb *tp; 2183 { 2184 struct in6pcb *in6p; 2185 size_t hdrsiz; 2186 2187 if (!tp || !tp->t_template || !(in6p = tp->t_in6pcb)) 2188 return 0; 2189 switch (tp->t_family) { 2190 case AF_INET6: 2191 /* XXX: should use currect direction. */ 2192 hdrsiz = ipsec6_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, in6p); 2193 break; 2194 case AF_INET: 2195 /* mapped address case - tricky */ 2196 default: 2197 hdrsiz = 0; 2198 break; 2199 } 2200 2201 return hdrsiz; 2202 } 2203 #endif 2204 #endif /*IPSEC*/ 2205 2206 /* 2207 * Determine the length of the TCP options for this connection. 2208 * 2209 * XXX: What do we do for SACK, when we add that? Just reserve 2210 * all of the space? Otherwise we can't exactly be incrementing 2211 * cwnd by an amount that varies depending on the amount we last 2212 * had to SACK! 2213 */ 2214 2215 u_int 2216 tcp_optlen(tp) 2217 struct tcpcb *tp; 2218 { 2219 u_int optlen; 2220 2221 optlen = 0; 2222 if ((tp->t_flags & (TF_REQ_TSTMP|TF_RCVD_TSTMP|TF_NOOPT)) == 2223 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 2224 optlen += TCPOLEN_TSTAMP_APPA; 2225 2226 #ifdef TCP_SIGNATURE 2227 #if defined(INET6) && defined(FAST_IPSEC) 2228 if (tp->t_family == AF_INET) 2229 #endif 2230 if (tp->t_flags & TF_SIGNATURE) 2231 optlen += TCPOLEN_SIGNATURE + 2; 2232 #endif /* TCP_SIGNATURE */ 2233 2234 return optlen; 2235 } 2236
Indexes created Mon Sep 22 13:09:51 GMT 2025