tcp_subr.c revision 1.143
1 /* $NetBSD: tcp_subr.c,v 1.143 2003/07/03 08:28:16 ragge 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. All advertising materials mentioning features or use of this software 82 * must display the following acknowledgement: 83 * This product includes software developed by the University of 84 * California, Berkeley and its contributors. 85 * 4. Neither the name of the University nor the names of its contributors 86 * may be used to endorse or promote products derived from this software 87 * without specific prior written permission. 88 * 89 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 90 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 91 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 92 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 93 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 94 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 95 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 96 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 97 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 98 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 99 * SUCH DAMAGE. 100 * 101 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 102 */ 103 104 #include <sys/cdefs.h> 105 __KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.143 2003/07/03 08:28:16 ragge Exp $"); 106 107 #include "opt_inet.h" 108 #include "opt_ipsec.h" 109 #include "opt_tcp_compat_42.h" 110 #include "opt_inet_csum.h" 111 #include "opt_mbuftrace.h" 112 #include "rnd.h" 113 114 #include <sys/param.h> 115 #include <sys/proc.h> 116 #include <sys/systm.h> 117 #include <sys/malloc.h> 118 #include <sys/mbuf.h> 119 #include <sys/socket.h> 120 #include <sys/socketvar.h> 121 #include <sys/protosw.h> 122 #include <sys/errno.h> 123 #include <sys/kernel.h> 124 #include <sys/pool.h> 125 #if NRND > 0 126 #include <sys/md5.h> 127 #include <sys/rnd.h> 128 #endif 129 130 #include <net/route.h> 131 #include <net/if.h> 132 133 #include <netinet/in.h> 134 #include <netinet/in_systm.h> 135 #include <netinet/ip.h> 136 #include <netinet/in_pcb.h> 137 #include <netinet/ip_var.h> 138 #include <netinet/ip_icmp.h> 139 140 #ifdef INET6 141 #ifndef INET 142 #include <netinet/in.h> 143 #endif 144 #include <netinet/ip6.h> 145 #include <netinet6/in6_pcb.h> 146 #include <netinet6/ip6_var.h> 147 #include <netinet6/in6_var.h> 148 #include <netinet6/ip6protosw.h> 149 #include <netinet/icmp6.h> 150 #include <netinet6/nd6.h> 151 #endif 152 153 #include <netinet/tcp.h> 154 #include <netinet/tcp_fsm.h> 155 #include <netinet/tcp_seq.h> 156 #include <netinet/tcp_timer.h> 157 #include <netinet/tcp_var.h> 158 #include <netinet/tcpip.h> 159 160 #ifdef IPSEC 161 #include <netinet6/ipsec.h> 162 #endif /*IPSEC*/ 163 164 #ifdef INET6 165 struct in6pcb tcb6; 166 #endif 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_copysmall = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 249 NULL, "tcp", "output copy small"); 250 struct evcnt tcp_output_copybig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 251 NULL, "tcp", "output copy big"); 252 struct evcnt tcp_output_refbig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 253 NULL, "tcp", "output reference big"); 254 #endif /* TCP_OUTPUT_COUNTERS */ 255 256 #ifdef TCP_REASS_COUNTERS 257 #include <sys/device.h> 258 259 struct evcnt tcp_reass_ = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 260 NULL, "tcp_reass", "calls"); 261 struct evcnt tcp_reass_empty = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 262 &tcp_reass_, "tcp_reass", "insert into empty queue"); 263 struct evcnt tcp_reass_iteration[8] = { 264 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", ">7 iterations"), 265 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "1 iteration"), 266 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "2 iterations"), 267 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "3 iterations"), 268 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "4 iterations"), 269 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "5 iterations"), 270 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "6 iterations"), 271 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "7 iterations"), 272 }; 273 struct evcnt tcp_reass_prependfirst = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 274 &tcp_reass_, "tcp_reass", "prepend to first"); 275 struct evcnt tcp_reass_prepend = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 276 &tcp_reass_, "tcp_reass", "prepend"); 277 struct evcnt tcp_reass_insert = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 278 &tcp_reass_, "tcp_reass", "insert"); 279 struct evcnt tcp_reass_inserttail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 280 &tcp_reass_, "tcp_reass", "insert at tail"); 281 struct evcnt tcp_reass_append = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 282 &tcp_reass_, "tcp_reass", "append"); 283 struct evcnt tcp_reass_appendtail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 284 &tcp_reass_, "tcp_reass", "append to tail fragment"); 285 struct evcnt tcp_reass_overlaptail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 286 &tcp_reass_, "tcp_reass", "overlap at end"); 287 struct evcnt tcp_reass_overlapfront = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 288 &tcp_reass_, "tcp_reass", "overlap at start"); 289 struct evcnt tcp_reass_segdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 290 &tcp_reass_, "tcp_reass", "duplicate segment"); 291 struct evcnt tcp_reass_fragdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 292 &tcp_reass_, "tcp_reass", "duplicate fragment"); 293 294 #endif /* TCP_REASS_COUNTERS */ 295 296 #ifdef MBUFTRACE 297 struct mowner tcp_mowner = { "tcp" }; 298 struct mowner tcp_rx_mowner = { "tcp", "rx" }; 299 struct mowner tcp_tx_mowner = { "tcp", "tx" }; 300 #endif 301 302 /* 303 * Tcp initialization 304 */ 305 void 306 tcp_init() 307 { 308 int hlen; 309 310 pool_init(&tcpcb_pool, sizeof(struct tcpcb), 0, 0, 0, "tcpcbpl", 311 NULL); 312 in_pcbinit(&tcbtable, tcbhashsize, tcbhashsize); 313 #ifdef INET6 314 tcb6.in6p_next = tcb6.in6p_prev = &tcb6; 315 #endif 316 317 hlen = sizeof(struct ip) + sizeof(struct tcphdr); 318 #ifdef INET6 319 if (sizeof(struct ip) < sizeof(struct ip6_hdr)) 320 hlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 321 #endif 322 if (max_protohdr < hlen) 323 max_protohdr = hlen; 324 if (max_linkhdr + hlen > MHLEN) 325 panic("tcp_init"); 326 327 #ifdef INET 328 icmp_mtudisc_callback_register(tcp_mtudisc_callback); 329 #endif 330 #ifdef INET6 331 icmp6_mtudisc_callback_register(tcp6_mtudisc_callback); 332 #endif 333 334 /* Initialize timer state. */ 335 tcp_timer_init(); 336 337 /* Initialize the compressed state engine. */ 338 syn_cache_init(); 339 340 #ifdef TCP_CSUM_COUNTERS 341 evcnt_attach_static(&tcp_hwcsum_bad); 342 evcnt_attach_static(&tcp_hwcsum_ok); 343 evcnt_attach_static(&tcp_hwcsum_data); 344 evcnt_attach_static(&tcp_swcsum); 345 #endif /* TCP_CSUM_COUNTERS */ 346 347 #ifdef TCP_OUTPUT_COUNTERS 348 evcnt_attach_static(&tcp_output_bigheader); 349 evcnt_attach_static(&tcp_output_copysmall); 350 evcnt_attach_static(&tcp_output_copybig); 351 evcnt_attach_static(&tcp_output_refbig); 352 #endif /* TCP_OUTPUT_COUNTERS */ 353 354 #ifdef TCP_REASS_COUNTERS 355 evcnt_attach_static(&tcp_reass_); 356 evcnt_attach_static(&tcp_reass_empty); 357 evcnt_attach_static(&tcp_reass_iteration[0]); 358 evcnt_attach_static(&tcp_reass_iteration[1]); 359 evcnt_attach_static(&tcp_reass_iteration[2]); 360 evcnt_attach_static(&tcp_reass_iteration[3]); 361 evcnt_attach_static(&tcp_reass_iteration[4]); 362 evcnt_attach_static(&tcp_reass_iteration[5]); 363 evcnt_attach_static(&tcp_reass_iteration[6]); 364 evcnt_attach_static(&tcp_reass_iteration[7]); 365 evcnt_attach_static(&tcp_reass_prependfirst); 366 evcnt_attach_static(&tcp_reass_prepend); 367 evcnt_attach_static(&tcp_reass_insert); 368 evcnt_attach_static(&tcp_reass_inserttail); 369 evcnt_attach_static(&tcp_reass_append); 370 evcnt_attach_static(&tcp_reass_appendtail); 371 evcnt_attach_static(&tcp_reass_overlaptail); 372 evcnt_attach_static(&tcp_reass_overlapfront); 373 evcnt_attach_static(&tcp_reass_segdup); 374 evcnt_attach_static(&tcp_reass_fragdup); 375 #endif /* TCP_REASS_COUNTERS */ 376 377 MOWNER_ATTACH(&tcp_tx_mowner); 378 MOWNER_ATTACH(&tcp_rx_mowner); 379 MOWNER_ATTACH(&tcp_mowner); 380 } 381 382 /* 383 * Create template to be used to send tcp packets on a connection. 384 * Call after host entry created, allocates an mbuf and fills 385 * in a skeletal tcp/ip header, minimizing the amount of work 386 * necessary when the connection is used. 387 */ 388 struct mbuf * 389 tcp_template(tp) 390 struct tcpcb *tp; 391 { 392 struct inpcb *inp = tp->t_inpcb; 393 #ifdef INET6 394 struct in6pcb *in6p = tp->t_in6pcb; 395 #endif 396 struct tcphdr *n; 397 struct mbuf *m; 398 int hlen; 399 400 switch (tp->t_family) { 401 case AF_INET: 402 hlen = sizeof(struct ip); 403 if (inp) 404 break; 405 #ifdef INET6 406 if (in6p) { 407 /* mapped addr case */ 408 if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr) 409 && IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) 410 break; 411 } 412 #endif 413 return NULL; /*EINVAL*/ 414 #ifdef INET6 415 case AF_INET6: 416 hlen = sizeof(struct ip6_hdr); 417 if (in6p) { 418 /* more sainty check? */ 419 break; 420 } 421 return NULL; /*EINVAL*/ 422 #endif 423 default: 424 hlen = 0; /*pacify gcc*/ 425 return NULL; /*EAFNOSUPPORT*/ 426 } 427 #ifdef DIAGNOSTIC 428 if (hlen + sizeof(struct tcphdr) > MCLBYTES) 429 panic("mclbytes too small for t_template"); 430 #endif 431 m = tp->t_template; 432 if (m && m->m_len == hlen + sizeof(struct tcphdr)) 433 ; 434 else { 435 if (m) 436 m_freem(m); 437 m = tp->t_template = NULL; 438 MGETHDR(m, M_DONTWAIT, MT_HEADER); 439 if (m && hlen + sizeof(struct tcphdr) > MHLEN) { 440 MCLGET(m, M_DONTWAIT); 441 if ((m->m_flags & M_EXT) == 0) { 442 m_free(m); 443 m = NULL; 444 } 445 } 446 if (m == NULL) 447 return NULL; 448 MCLAIM(m, &tcp_mowner); 449 m->m_pkthdr.len = m->m_len = hlen + sizeof(struct tcphdr); 450 } 451 452 bzero(mtod(m, caddr_t), m->m_len); 453 454 n = (struct tcphdr *)(mtod(m, caddr_t) + hlen); 455 456 switch (tp->t_family) { 457 case AF_INET: 458 { 459 struct ipovly *ipov; 460 mtod(m, struct ip *)->ip_v = 4; 461 ipov = mtod(m, struct ipovly *); 462 ipov->ih_pr = IPPROTO_TCP; 463 ipov->ih_len = htons(sizeof(struct tcphdr)); 464 if (inp) { 465 ipov->ih_src = inp->inp_laddr; 466 ipov->ih_dst = inp->inp_faddr; 467 } 468 #ifdef INET6 469 else if (in6p) { 470 /* mapped addr case */ 471 bcopy(&in6p->in6p_laddr.s6_addr32[3], &ipov->ih_src, 472 sizeof(ipov->ih_src)); 473 bcopy(&in6p->in6p_faddr.s6_addr32[3], &ipov->ih_dst, 474 sizeof(ipov->ih_dst)); 475 } 476 #endif 477 /* 478 * Compute the pseudo-header portion of the checksum 479 * now. We incrementally add in the TCP option and 480 * payload lengths later, and then compute the TCP 481 * checksum right before the packet is sent off onto 482 * the wire. 483 */ 484 n->th_sum = in_cksum_phdr(ipov->ih_src.s_addr, 485 ipov->ih_dst.s_addr, 486 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 487 break; 488 } 489 #ifdef INET6 490 case AF_INET6: 491 { 492 struct ip6_hdr *ip6; 493 mtod(m, struct ip *)->ip_v = 6; 494 ip6 = mtod(m, struct ip6_hdr *); 495 ip6->ip6_nxt = IPPROTO_TCP; 496 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 497 ip6->ip6_src = in6p->in6p_laddr; 498 ip6->ip6_dst = in6p->in6p_faddr; 499 ip6->ip6_flow = in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK; 500 if (ip6_auto_flowlabel) { 501 ip6->ip6_flow &= ~IPV6_FLOWLABEL_MASK; 502 ip6->ip6_flow |= 503 (htonl(ip6_flow_seq++) & IPV6_FLOWLABEL_MASK); 504 } 505 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 506 ip6->ip6_vfc |= IPV6_VERSION; 507 508 /* 509 * Compute the pseudo-header portion of the checksum 510 * now. We incrementally add in the TCP option and 511 * payload lengths later, and then compute the TCP 512 * checksum right before the packet is sent off onto 513 * the wire. 514 */ 515 n->th_sum = in6_cksum_phdr(&in6p->in6p_laddr, 516 &in6p->in6p_faddr, htonl(sizeof(struct tcphdr)), 517 htonl(IPPROTO_TCP)); 518 break; 519 } 520 #endif 521 } 522 if (inp) { 523 n->th_sport = inp->inp_lport; 524 n->th_dport = inp->inp_fport; 525 } 526 #ifdef INET6 527 else if (in6p) { 528 n->th_sport = in6p->in6p_lport; 529 n->th_dport = in6p->in6p_fport; 530 } 531 #endif 532 n->th_seq = 0; 533 n->th_ack = 0; 534 n->th_x2 = 0; 535 n->th_off = 5; 536 n->th_flags = 0; 537 n->th_win = 0; 538 n->th_urp = 0; 539 return (m); 540 } 541 542 /* 543 * Send a single message to the TCP at address specified by 544 * the given TCP/IP header. If m == 0, then we make a copy 545 * of the tcpiphdr at ti and send directly to the addressed host. 546 * This is used to force keep alive messages out using the TCP 547 * template for a connection tp->t_template. If flags are given 548 * then we send a message back to the TCP which originated the 549 * segment ti, and discard the mbuf containing it and any other 550 * attached mbufs. 551 * 552 * In any case the ack and sequence number of the transmitted 553 * segment are as specified by the parameters. 554 */ 555 int 556 tcp_respond(tp, template, m, th0, ack, seq, flags) 557 struct tcpcb *tp; 558 struct mbuf *template; 559 struct mbuf *m; 560 struct tcphdr *th0; 561 tcp_seq ack, seq; 562 int flags; 563 { 564 struct route *ro; 565 int error, tlen, win = 0; 566 int hlen; 567 struct ip *ip; 568 #ifdef INET6 569 struct ip6_hdr *ip6; 570 #endif 571 int family; /* family on packet, not inpcb/in6pcb! */ 572 struct tcphdr *th; 573 574 if (tp != NULL && (flags & TH_RST) == 0) { 575 #ifdef DIAGNOSTIC 576 if (tp->t_inpcb && tp->t_in6pcb) 577 panic("tcp_respond: both t_inpcb and t_in6pcb are set"); 578 #endif 579 #ifdef INET 580 if (tp->t_inpcb) 581 win = sbspace(&tp->t_inpcb->inp_socket->so_rcv); 582 #endif 583 #ifdef INET6 584 if (tp->t_in6pcb) 585 win = sbspace(&tp->t_in6pcb->in6p_socket->so_rcv); 586 #endif 587 } 588 589 th = NULL; /* Quell uninitialized warning */ 590 ip = NULL; 591 #ifdef INET6 592 ip6 = NULL; 593 #endif 594 if (m == 0) { 595 if (!template) 596 return EINVAL; 597 598 /* get family information from template */ 599 switch (mtod(template, struct ip *)->ip_v) { 600 case 4: 601 family = AF_INET; 602 hlen = sizeof(struct ip); 603 break; 604 #ifdef INET6 605 case 6: 606 family = AF_INET6; 607 hlen = sizeof(struct ip6_hdr); 608 break; 609 #endif 610 default: 611 return EAFNOSUPPORT; 612 } 613 614 MGETHDR(m, M_DONTWAIT, MT_HEADER); 615 if (m) { 616 MCLAIM(m, &tcp_tx_mowner); 617 MCLGET(m, M_DONTWAIT); 618 if ((m->m_flags & M_EXT) == 0) { 619 m_free(m); 620 m = NULL; 621 } 622 } 623 if (m == NULL) 624 return (ENOBUFS); 625 626 if (tcp_compat_42) 627 tlen = 1; 628 else 629 tlen = 0; 630 631 m->m_data += max_linkhdr; 632 bcopy(mtod(template, caddr_t), mtod(m, caddr_t), 633 template->m_len); 634 switch (family) { 635 case AF_INET: 636 ip = mtod(m, struct ip *); 637 th = (struct tcphdr *)(ip + 1); 638 break; 639 #ifdef INET6 640 case AF_INET6: 641 ip6 = mtod(m, struct ip6_hdr *); 642 th = (struct tcphdr *)(ip6 + 1); 643 break; 644 #endif 645 #if 0 646 default: 647 /* noone will visit here */ 648 m_freem(m); 649 return EAFNOSUPPORT; 650 #endif 651 } 652 flags = TH_ACK; 653 } else { 654 655 if ((m->m_flags & M_PKTHDR) == 0) { 656 #if 0 657 printf("non PKTHDR to tcp_respond\n"); 658 #endif 659 m_freem(m); 660 return EINVAL; 661 } 662 #ifdef DIAGNOSTIC 663 if (!th0) 664 panic("th0 == NULL in tcp_respond"); 665 #endif 666 667 /* get family information from m */ 668 switch (mtod(m, struct ip *)->ip_v) { 669 case 4: 670 family = AF_INET; 671 hlen = sizeof(struct ip); 672 ip = mtod(m, struct ip *); 673 break; 674 #ifdef INET6 675 case 6: 676 family = AF_INET6; 677 hlen = sizeof(struct ip6_hdr); 678 ip6 = mtod(m, struct ip6_hdr *); 679 break; 680 #endif 681 default: 682 m_freem(m); 683 return EAFNOSUPPORT; 684 } 685 if ((flags & TH_SYN) == 0 || sizeof(*th0) > (th0->th_off << 2)) 686 tlen = sizeof(*th0); 687 else 688 tlen = th0->th_off << 2; 689 690 if (m->m_len > hlen + tlen && (m->m_flags & M_EXT) == 0 && 691 mtod(m, caddr_t) + hlen == (caddr_t)th0) { 692 m->m_len = hlen + tlen; 693 m_freem(m->m_next); 694 m->m_next = NULL; 695 } else { 696 struct mbuf *n; 697 698 #ifdef DIAGNOSTIC 699 if (max_linkhdr + hlen + tlen > MCLBYTES) { 700 m_freem(m); 701 return EMSGSIZE; 702 } 703 #endif 704 MGETHDR(n, M_DONTWAIT, MT_HEADER); 705 if (n && max_linkhdr + hlen + tlen > MHLEN) { 706 MCLGET(n, M_DONTWAIT); 707 if ((n->m_flags & M_EXT) == 0) { 708 m_freem(n); 709 n = NULL; 710 } 711 } 712 if (!n) { 713 m_freem(m); 714 return ENOBUFS; 715 } 716 717 MCLAIM(n, &tcp_tx_mowner); 718 n->m_data += max_linkhdr; 719 n->m_len = hlen + tlen; 720 m_copyback(n, 0, hlen, mtod(m, caddr_t)); 721 m_copyback(n, hlen, tlen, (caddr_t)th0); 722 723 m_freem(m); 724 m = n; 725 n = NULL; 726 } 727 728 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 729 switch (family) { 730 case AF_INET: 731 ip = mtod(m, struct ip *); 732 th = (struct tcphdr *)(ip + 1); 733 ip->ip_p = IPPROTO_TCP; 734 xchg(ip->ip_dst, ip->ip_src, struct in_addr); 735 ip->ip_p = IPPROTO_TCP; 736 break; 737 #ifdef INET6 738 case AF_INET6: 739 ip6 = mtod(m, struct ip6_hdr *); 740 th = (struct tcphdr *)(ip6 + 1); 741 ip6->ip6_nxt = IPPROTO_TCP; 742 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 743 ip6->ip6_nxt = IPPROTO_TCP; 744 break; 745 #endif 746 #if 0 747 default: 748 /* noone will visit here */ 749 m_freem(m); 750 return EAFNOSUPPORT; 751 #endif 752 } 753 xchg(th->th_dport, th->th_sport, u_int16_t); 754 #undef xchg 755 tlen = 0; /*be friendly with the following code*/ 756 } 757 th->th_seq = htonl(seq); 758 th->th_ack = htonl(ack); 759 th->th_x2 = 0; 760 if ((flags & TH_SYN) == 0) { 761 if (tp) 762 win >>= tp->rcv_scale; 763 if (win > TCP_MAXWIN) 764 win = TCP_MAXWIN; 765 th->th_win = htons((u_int16_t)win); 766 th->th_off = sizeof (struct tcphdr) >> 2; 767 tlen += sizeof(*th); 768 } else 769 tlen += th->th_off << 2; 770 m->m_len = hlen + tlen; 771 m->m_pkthdr.len = hlen + tlen; 772 m->m_pkthdr.rcvif = (struct ifnet *) 0; 773 th->th_flags = flags; 774 th->th_urp = 0; 775 776 switch (family) { 777 #ifdef INET 778 case AF_INET: 779 { 780 struct ipovly *ipov = (struct ipovly *)ip; 781 bzero(ipov->ih_x1, sizeof ipov->ih_x1); 782 ipov->ih_len = htons((u_int16_t)tlen); 783 784 th->th_sum = 0; 785 th->th_sum = in_cksum(m, hlen + tlen); 786 ip->ip_len = htons(hlen + tlen); 787 ip->ip_ttl = ip_defttl; 788 break; 789 } 790 #endif 791 #ifdef INET6 792 case AF_INET6: 793 { 794 th->th_sum = 0; 795 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr), 796 tlen); 797 ip6->ip6_plen = ntohs(tlen); 798 if (tp && tp->t_in6pcb) { 799 struct ifnet *oifp; 800 ro = (struct route *)&tp->t_in6pcb->in6p_route; 801 oifp = ro->ro_rt ? ro->ro_rt->rt_ifp : NULL; 802 ip6->ip6_hlim = in6_selecthlim(tp->t_in6pcb, oifp); 803 } else 804 ip6->ip6_hlim = ip6_defhlim; 805 ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK; 806 if (ip6_auto_flowlabel) { 807 ip6->ip6_flow |= 808 (htonl(ip6_flow_seq++) & IPV6_FLOWLABEL_MASK); 809 } 810 break; 811 } 812 #endif 813 } 814 815 #ifdef IPSEC 816 (void)ipsec_setsocket(m, NULL); 817 #endif /*IPSEC*/ 818 819 if (tp != NULL && tp->t_inpcb != NULL) { 820 ro = &tp->t_inpcb->inp_route; 821 #ifdef IPSEC 822 if (ipsec_setsocket(m, tp->t_inpcb->inp_socket) != 0) { 823 m_freem(m); 824 return ENOBUFS; 825 } 826 #endif 827 #ifdef DIAGNOSTIC 828 if (family != AF_INET) 829 panic("tcp_respond: address family mismatch"); 830 if (!in_hosteq(ip->ip_dst, tp->t_inpcb->inp_faddr)) { 831 panic("tcp_respond: ip_dst %x != inp_faddr %x", 832 ntohl(ip->ip_dst.s_addr), 833 ntohl(tp->t_inpcb->inp_faddr.s_addr)); 834 } 835 #endif 836 } 837 #ifdef INET6 838 else if (tp != NULL && tp->t_in6pcb != NULL) { 839 ro = (struct route *)&tp->t_in6pcb->in6p_route; 840 #ifdef IPSEC 841 if (ipsec_setsocket(m, tp->t_in6pcb->in6p_socket) != 0) { 842 m_freem(m); 843 return ENOBUFS; 844 } 845 #endif 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 NULL); 873 break; 874 #endif 875 #ifdef INET6 876 case AF_INET6: 877 error = ip6_output(m, NULL, (struct route_in6 *)ro, 0, NULL, 878 NULL); 879 break; 880 #endif 881 default: 882 error = EAFNOSUPPORT; 883 break; 884 } 885 886 return (error); 887 } 888 889 /* 890 * Create a new TCP control block, making an 891 * empty reassembly queue and hooking it to the argument 892 * protocol control block. 893 */ 894 struct tcpcb * 895 tcp_newtcpcb(family, aux) 896 int family; /* selects inpcb, or in6pcb */ 897 void *aux; 898 { 899 struct tcpcb *tp; 900 int i; 901 902 switch (family) { 903 case PF_INET: 904 break; 905 #ifdef INET6 906 case PF_INET6: 907 break; 908 #endif 909 default: 910 return NULL; 911 } 912 913 tp = pool_get(&tcpcb_pool, PR_NOWAIT); 914 if (tp == NULL) 915 return (NULL); 916 bzero((caddr_t)tp, sizeof(struct tcpcb)); 917 TAILQ_INIT(&tp->segq); 918 TAILQ_INIT(&tp->timeq); 919 tp->t_family = family; /* may be overridden later on */ 920 tp->t_peermss = tcp_mssdflt; 921 tp->t_ourmss = tcp_mssdflt; 922 tp->t_segsz = tcp_mssdflt; 923 LIST_INIT(&tp->t_sc); 924 925 tp->t_lastm = NULL; 926 tp->t_lastoff = 0; 927 928 callout_init(&tp->t_delack_ch); 929 for (i = 0; i < TCPT_NTIMERS; i++) 930 TCP_TIMER_INIT(tp, i); 931 932 tp->t_flags = 0; 933 if (tcp_do_rfc1323 && tcp_do_win_scale) 934 tp->t_flags |= TF_REQ_SCALE; 935 if (tcp_do_rfc1323 && tcp_do_timestamps) 936 tp->t_flags |= TF_REQ_TSTMP; 937 if (tcp_do_sack == 2) 938 tp->t_flags |= TF_WILL_SACK; 939 else if (tcp_do_sack == 1) 940 tp->t_flags |= TF_WILL_SACK|TF_IGNR_RXSACK; 941 tp->t_flags |= TF_CANT_TXSACK; 942 switch (family) { 943 case PF_INET: 944 tp->t_inpcb = (struct inpcb *)aux; 945 tp->t_mtudisc = ip_mtudisc; 946 break; 947 #ifdef INET6 948 case PF_INET6: 949 tp->t_in6pcb = (struct in6pcb *)aux; 950 /* for IPv6, always try to run path MTU discovery */ 951 tp->t_mtudisc = 1; 952 break; 953 #endif 954 } 955 /* 956 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 957 * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives 958 * reasonable initial retransmit time. 959 */ 960 tp->t_srtt = TCPTV_SRTTBASE; 961 tp->t_rttvar = tcp_rttdflt * PR_SLOWHZ << (TCP_RTTVAR_SHIFT + 2 - 1); 962 tp->t_rttmin = TCPTV_MIN; 963 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), 964 TCPTV_MIN, TCPTV_REXMTMAX); 965 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 966 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 967 if (family == AF_INET) { 968 struct inpcb *inp = (struct inpcb *)aux; 969 inp->inp_ip.ip_ttl = ip_defttl; 970 inp->inp_ppcb = (caddr_t)tp; 971 } 972 #ifdef INET6 973 else if (family == AF_INET6) { 974 struct in6pcb *in6p = (struct in6pcb *)aux; 975 in6p->in6p_ip6.ip6_hlim = in6_selecthlim(in6p, 976 in6p->in6p_route.ro_rt ? in6p->in6p_route.ro_rt->rt_ifp 977 : NULL); 978 in6p->in6p_ppcb = (caddr_t)tp; 979 } 980 #endif 981 982 /* 983 * Initialize our timebase. When we send timestamps, we take 984 * the delta from tcp_now -- this means each connection always 985 * gets a timebase of 0, which makes it, among other things, 986 * more difficult to determine how long a system has been up, 987 * and thus how many TCP sequence increments have occurred. 988 */ 989 tp->ts_timebase = tcp_now; 990 991 return (tp); 992 } 993 994 /* 995 * Drop a TCP connection, reporting 996 * the specified error. If connection is synchronized, 997 * then send a RST to peer. 998 */ 999 struct tcpcb * 1000 tcp_drop(tp, errno) 1001 struct tcpcb *tp; 1002 int errno; 1003 { 1004 struct socket *so = NULL; 1005 1006 #ifdef DIAGNOSTIC 1007 if (tp->t_inpcb && tp->t_in6pcb) 1008 panic("tcp_drop: both t_inpcb and t_in6pcb are set"); 1009 #endif 1010 #ifdef INET 1011 if (tp->t_inpcb) 1012 so = tp->t_inpcb->inp_socket; 1013 #endif 1014 #ifdef INET6 1015 if (tp->t_in6pcb) 1016 so = tp->t_in6pcb->in6p_socket; 1017 #endif 1018 if (!so) 1019 return NULL; 1020 1021 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1022 tp->t_state = TCPS_CLOSED; 1023 (void) tcp_output(tp); 1024 tcpstat.tcps_drops++; 1025 } else 1026 tcpstat.tcps_conndrops++; 1027 if (errno == ETIMEDOUT && tp->t_softerror) 1028 errno = tp->t_softerror; 1029 so->so_error = errno; 1030 return (tcp_close(tp)); 1031 } 1032 1033 /* 1034 * Close a TCP control block: 1035 * discard all space held by the tcp 1036 * discard internet protocol block 1037 * wake up any sleepers 1038 */ 1039 struct tcpcb * 1040 tcp_close(tp) 1041 struct tcpcb *tp; 1042 { 1043 struct inpcb *inp; 1044 #ifdef INET6 1045 struct in6pcb *in6p; 1046 #endif 1047 struct socket *so; 1048 #ifdef RTV_RTT 1049 struct rtentry *rt; 1050 #endif 1051 struct route *ro; 1052 1053 inp = tp->t_inpcb; 1054 #ifdef INET6 1055 in6p = tp->t_in6pcb; 1056 #endif 1057 so = NULL; 1058 ro = NULL; 1059 if (inp) { 1060 so = inp->inp_socket; 1061 ro = &inp->inp_route; 1062 } 1063 #ifdef INET6 1064 else if (in6p) { 1065 so = in6p->in6p_socket; 1066 ro = (struct route *)&in6p->in6p_route; 1067 } 1068 #endif 1069 1070 #ifdef RTV_RTT 1071 /* 1072 * If we sent enough data to get some meaningful characteristics, 1073 * save them in the routing entry. 'Enough' is arbitrarily 1074 * defined as the sendpipesize (default 4K) * 16. This would 1075 * give us 16 rtt samples assuming we only get one sample per 1076 * window (the usual case on a long haul net). 16 samples is 1077 * enough for the srtt filter to converge to within 5% of the correct 1078 * value; fewer samples and we could save a very bogus rtt. 1079 * 1080 * Don't update the default route's characteristics and don't 1081 * update anything that the user "locked". 1082 */ 1083 if (SEQ_LT(tp->iss + so->so_snd.sb_hiwat * 16, tp->snd_max) && 1084 ro && (rt = ro->ro_rt) && 1085 !in_nullhost(satosin(rt_key(rt))->sin_addr)) { 1086 u_long i = 0; 1087 1088 if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) { 1089 i = tp->t_srtt * 1090 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 1091 if (rt->rt_rmx.rmx_rtt && i) 1092 /* 1093 * filter this update to half the old & half 1094 * the new values, converting scale. 1095 * See route.h and tcp_var.h for a 1096 * description of the scaling constants. 1097 */ 1098 rt->rt_rmx.rmx_rtt = 1099 (rt->rt_rmx.rmx_rtt + i) / 2; 1100 else 1101 rt->rt_rmx.rmx_rtt = i; 1102 } 1103 if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) { 1104 i = tp->t_rttvar * 1105 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTTVAR_SHIFT + 2)); 1106 if (rt->rt_rmx.rmx_rttvar && i) 1107 rt->rt_rmx.rmx_rttvar = 1108 (rt->rt_rmx.rmx_rttvar + i) / 2; 1109 else 1110 rt->rt_rmx.rmx_rttvar = i; 1111 } 1112 /* 1113 * update the pipelimit (ssthresh) if it has been updated 1114 * already or if a pipesize was specified & the threshhold 1115 * got below half the pipesize. I.e., wait for bad news 1116 * before we start updating, then update on both good 1117 * and bad news. 1118 */ 1119 if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 && 1120 (i = tp->snd_ssthresh) && rt->rt_rmx.rmx_ssthresh) || 1121 i < (rt->rt_rmx.rmx_sendpipe / 2)) { 1122 /* 1123 * convert the limit from user data bytes to 1124 * packets then to packet data bytes. 1125 */ 1126 i = (i + tp->t_segsz / 2) / tp->t_segsz; 1127 if (i < 2) 1128 i = 2; 1129 i *= (u_long)(tp->t_segsz + sizeof (struct tcpiphdr)); 1130 if (rt->rt_rmx.rmx_ssthresh) 1131 rt->rt_rmx.rmx_ssthresh = 1132 (rt->rt_rmx.rmx_ssthresh + i) / 2; 1133 else 1134 rt->rt_rmx.rmx_ssthresh = i; 1135 } 1136 } 1137 #endif /* RTV_RTT */ 1138 /* free the reassembly queue, if any */ 1139 TCP_REASS_LOCK(tp); 1140 (void) tcp_freeq(tp); 1141 TCP_REASS_UNLOCK(tp); 1142 1143 tcp_canceltimers(tp); 1144 TCP_CLEAR_DELACK(tp); 1145 syn_cache_cleanup(tp); 1146 1147 if (tp->t_template) { 1148 m_free(tp->t_template); 1149 tp->t_template = NULL; 1150 } 1151 pool_put(&tcpcb_pool, tp); 1152 if (inp) { 1153 inp->inp_ppcb = 0; 1154 soisdisconnected(so); 1155 in_pcbdetach(inp); 1156 } 1157 #ifdef INET6 1158 else if (in6p) { 1159 in6p->in6p_ppcb = 0; 1160 soisdisconnected(so); 1161 in6_pcbdetach(in6p); 1162 } 1163 #endif 1164 tcpstat.tcps_closed++; 1165 return ((struct tcpcb *)0); 1166 } 1167 1168 int 1169 tcp_freeq(tp) 1170 struct tcpcb *tp; 1171 { 1172 struct ipqent *qe; 1173 int rv = 0; 1174 #ifdef TCPREASS_DEBUG 1175 int i = 0; 1176 #endif 1177 1178 TCP_REASS_LOCK_CHECK(tp); 1179 1180 while ((qe = TAILQ_FIRST(&tp->segq)) != NULL) { 1181 #ifdef TCPREASS_DEBUG 1182 printf("tcp_freeq[%p,%d]: %u:%u(%u) 0x%02x\n", 1183 tp, i++, qe->ipqe_seq, qe->ipqe_seq + qe->ipqe_len, 1184 qe->ipqe_len, qe->ipqe_flags & (TH_SYN|TH_FIN|TH_RST)); 1185 #endif 1186 TAILQ_REMOVE(&tp->segq, qe, ipqe_q); 1187 TAILQ_REMOVE(&tp->timeq, qe, ipqe_timeq); 1188 m_freem(qe->ipqe_m); 1189 pool_put(&ipqent_pool, qe); 1190 rv = 1; 1191 } 1192 return (rv); 1193 } 1194 1195 /* 1196 * Protocol drain routine. Called when memory is in short supply. 1197 */ 1198 void 1199 tcp_drain() 1200 { 1201 struct inpcb *inp; 1202 struct tcpcb *tp; 1203 1204 /* 1205 * Free the sequence queue of all TCP connections. 1206 */ 1207 inp = CIRCLEQ_FIRST(&tcbtable.inpt_queue); 1208 if (inp) /* XXX */ 1209 CIRCLEQ_FOREACH(inp, &tcbtable.inpt_queue, inp_queue) { 1210 if ((tp = intotcpcb(inp)) != NULL) { 1211 /* 1212 * We may be called from a device's interrupt 1213 * context. If the tcpcb is already busy, 1214 * just bail out now. 1215 */ 1216 if (tcp_reass_lock_try(tp) == 0) 1217 continue; 1218 if (tcp_freeq(tp)) 1219 tcpstat.tcps_connsdrained++; 1220 TCP_REASS_UNLOCK(tp); 1221 } 1222 } 1223 } 1224 1225 #ifdef INET6 1226 void 1227 tcp6_drain() 1228 { 1229 struct in6pcb *in6p; 1230 struct tcpcb *tp; 1231 struct in6pcb *head = &tcb6; 1232 1233 /* 1234 * Free the sequence queue of all TCP connections. 1235 */ 1236 for (in6p = head->in6p_next; in6p != head; in6p = in6p->in6p_next) { 1237 if ((tp = in6totcpcb(in6p)) != NULL) { 1238 /* 1239 * We may be called from a device's interrupt 1240 * context. If the tcpcb is already busy, 1241 * just bail out now. 1242 */ 1243 if (tcp_reass_lock_try(tp) == 0) 1244 continue; 1245 if (tcp_freeq(tp)) 1246 tcpstat.tcps_connsdrained++; 1247 TCP_REASS_UNLOCK(tp); 1248 } 1249 } 1250 } 1251 #endif 1252 1253 /* 1254 * Notify a tcp user of an asynchronous error; 1255 * store error as soft error, but wake up user 1256 * (for now, won't do anything until can select for soft error). 1257 */ 1258 void 1259 tcp_notify(inp, error) 1260 struct inpcb *inp; 1261 int error; 1262 { 1263 struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb; 1264 struct socket *so = inp->inp_socket; 1265 1266 /* 1267 * Ignore some errors if we are hooked up. 1268 * If connection hasn't completed, has retransmitted several times, 1269 * and receives a second error, give up now. This is better 1270 * than waiting a long time to establish a connection that 1271 * can never complete. 1272 */ 1273 if (tp->t_state == TCPS_ESTABLISHED && 1274 (error == EHOSTUNREACH || error == ENETUNREACH || 1275 error == EHOSTDOWN)) { 1276 return; 1277 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1278 tp->t_rxtshift > 3 && tp->t_softerror) 1279 so->so_error = error; 1280 else 1281 tp->t_softerror = error; 1282 wakeup((caddr_t) &so->so_timeo); 1283 sorwakeup(so); 1284 sowwakeup(so); 1285 } 1286 1287 #ifdef INET6 1288 void 1289 tcp6_notify(in6p, error) 1290 struct in6pcb *in6p; 1291 int error; 1292 { 1293 struct tcpcb *tp = (struct tcpcb *)in6p->in6p_ppcb; 1294 struct socket *so = in6p->in6p_socket; 1295 1296 /* 1297 * Ignore some errors if we are hooked up. 1298 * If connection hasn't completed, has retransmitted several times, 1299 * and receives a second error, give up now. This is better 1300 * than waiting a long time to establish a connection that 1301 * can never complete. 1302 */ 1303 if (tp->t_state == TCPS_ESTABLISHED && 1304 (error == EHOSTUNREACH || error == ENETUNREACH || 1305 error == EHOSTDOWN)) { 1306 return; 1307 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1308 tp->t_rxtshift > 3 && tp->t_softerror) 1309 so->so_error = error; 1310 else 1311 tp->t_softerror = error; 1312 wakeup((caddr_t) &so->so_timeo); 1313 sorwakeup(so); 1314 sowwakeup(so); 1315 } 1316 #endif 1317 1318 #ifdef INET6 1319 void 1320 tcp6_ctlinput(cmd, sa, d) 1321 int cmd; 1322 struct sockaddr *sa; 1323 void *d; 1324 { 1325 struct tcphdr th; 1326 void (*notify) __P((struct in6pcb *, int)) = tcp6_notify; 1327 int nmatch; 1328 struct ip6_hdr *ip6; 1329 const struct sockaddr_in6 *sa6_src = NULL; 1330 struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)sa; 1331 struct mbuf *m; 1332 int off; 1333 1334 if (sa->sa_family != AF_INET6 || 1335 sa->sa_len != sizeof(struct sockaddr_in6)) 1336 return; 1337 if ((unsigned)cmd >= PRC_NCMDS) 1338 return; 1339 else if (cmd == PRC_QUENCH) { 1340 /* XXX there's no PRC_QUENCH in IPv6 */ 1341 notify = tcp6_quench; 1342 } else if (PRC_IS_REDIRECT(cmd)) 1343 notify = in6_rtchange, d = NULL; 1344 else if (cmd == PRC_MSGSIZE) 1345 ; /* special code is present, see below */ 1346 else if (cmd == PRC_HOSTDEAD) 1347 d = NULL; 1348 else if (inet6ctlerrmap[cmd] == 0) 1349 return; 1350 1351 /* if the parameter is from icmp6, decode it. */ 1352 if (d != NULL) { 1353 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 1354 m = ip6cp->ip6c_m; 1355 ip6 = ip6cp->ip6c_ip6; 1356 off = ip6cp->ip6c_off; 1357 sa6_src = ip6cp->ip6c_src; 1358 } else { 1359 m = NULL; 1360 ip6 = NULL; 1361 sa6_src = &sa6_any; 1362 } 1363 1364 if (ip6) { 1365 /* 1366 * XXX: We assume that when ip6 is non NULL, 1367 * M and OFF are valid. 1368 */ 1369 1370 /* check if we can safely examine src and dst ports */ 1371 if (m->m_pkthdr.len < off + sizeof(th)) { 1372 if (cmd == PRC_MSGSIZE) 1373 icmp6_mtudisc_update((struct ip6ctlparam *)d, 0); 1374 return; 1375 } 1376 1377 bzero(&th, sizeof(th)); 1378 m_copydata(m, off, sizeof(th), (caddr_t)&th); 1379 1380 if (cmd == PRC_MSGSIZE) { 1381 int valid = 0; 1382 1383 /* 1384 * Check to see if we have a valid TCP connection 1385 * corresponding to the address in the ICMPv6 message 1386 * payload. 1387 */ 1388 if (in6_pcblookup_connect(&tcb6, &sa6->sin6_addr, 1389 th.th_dport, (struct in6_addr *)&sa6_src->sin6_addr, 1390 th.th_sport, 0)) 1391 valid++; 1392 1393 /* 1394 * Depending on the value of "valid" and routing table 1395 * size (mtudisc_{hi,lo}wat), we will: 1396 * - recalcurate the new MTU and create the 1397 * corresponding routing entry, or 1398 * - ignore the MTU change notification. 1399 */ 1400 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid); 1401 1402 /* 1403 * no need to call in6_pcbnotify, it should have been 1404 * called via callback if necessary 1405 */ 1406 return; 1407 } 1408 1409 nmatch = in6_pcbnotify(&tcb6, sa, th.th_dport, 1410 (struct sockaddr *)sa6_src, th.th_sport, cmd, NULL, notify); 1411 if (nmatch == 0 && syn_cache_count && 1412 (inet6ctlerrmap[cmd] == EHOSTUNREACH || 1413 inet6ctlerrmap[cmd] == ENETUNREACH || 1414 inet6ctlerrmap[cmd] == EHOSTDOWN)) 1415 syn_cache_unreach((struct sockaddr *)sa6_src, 1416 sa, &th); 1417 } else { 1418 (void) in6_pcbnotify(&tcb6, sa, 0, (struct sockaddr *)sa6_src, 1419 0, cmd, NULL, notify); 1420 } 1421 } 1422 #endif 1423 1424 #ifdef INET 1425 /* assumes that ip header and tcp header are contiguous on mbuf */ 1426 void * 1427 tcp_ctlinput(cmd, sa, v) 1428 int cmd; 1429 struct sockaddr *sa; 1430 void *v; 1431 { 1432 struct ip *ip = v; 1433 struct tcphdr *th; 1434 struct icmp *icp; 1435 extern const int inetctlerrmap[]; 1436 void (*notify) __P((struct inpcb *, int)) = tcp_notify; 1437 int errno; 1438 int nmatch; 1439 #ifdef INET6 1440 struct in6_addr src6, dst6; 1441 #endif 1442 1443 if (sa->sa_family != AF_INET || 1444 sa->sa_len != sizeof(struct sockaddr_in)) 1445 return NULL; 1446 if ((unsigned)cmd >= PRC_NCMDS) 1447 return NULL; 1448 errno = inetctlerrmap[cmd]; 1449 if (cmd == PRC_QUENCH) 1450 notify = tcp_quench; 1451 else if (PRC_IS_REDIRECT(cmd)) 1452 notify = in_rtchange, ip = 0; 1453 else if (cmd == PRC_MSGSIZE && ip && ip->ip_v == 4) { 1454 /* 1455 * Check to see if we have a valid TCP connection 1456 * corresponding to the address in the ICMP message 1457 * payload. 1458 * 1459 * Boundary check is made in icmp_input(), with ICMP_ADVLENMIN. 1460 */ 1461 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1462 #ifdef INET6 1463 memset(&src6, 0, sizeof(src6)); 1464 memset(&dst6, 0, sizeof(dst6)); 1465 src6.s6_addr16[5] = dst6.s6_addr16[5] = 0xffff; 1466 memcpy(&src6.s6_addr32[3], &ip->ip_src, sizeof(struct in_addr)); 1467 memcpy(&dst6.s6_addr32[3], &ip->ip_dst, sizeof(struct in_addr)); 1468 #endif 1469 if (in_pcblookup_connect(&tcbtable, ip->ip_dst, th->th_dport, 1470 ip->ip_src, th->th_sport) != NULL) 1471 ; 1472 #ifdef INET6 1473 else if (in6_pcblookup_connect(&tcb6, &dst6, 1474 th->th_dport, &src6, th->th_sport, 0) != NULL) 1475 ; 1476 #endif 1477 else 1478 return NULL; 1479 1480 /* 1481 * Now that we've validated that we are actually communicating 1482 * with the host indicated in the ICMP message, locate the 1483 * ICMP header, recalculate the new MTU, and create the 1484 * corresponding routing entry. 1485 */ 1486 icp = (struct icmp *)((caddr_t)ip - 1487 offsetof(struct icmp, icmp_ip)); 1488 icmp_mtudisc(icp, ip->ip_dst); 1489 1490 return NULL; 1491 } else if (cmd == PRC_HOSTDEAD) 1492 ip = 0; 1493 else if (errno == 0) 1494 return NULL; 1495 if (ip && ip->ip_v == 4 && sa->sa_family == AF_INET) { 1496 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1497 nmatch = in_pcbnotify(&tcbtable, satosin(sa)->sin_addr, 1498 th->th_dport, ip->ip_src, th->th_sport, errno, notify); 1499 if (nmatch == 0 && syn_cache_count && 1500 (inetctlerrmap[cmd] == EHOSTUNREACH || 1501 inetctlerrmap[cmd] == ENETUNREACH || 1502 inetctlerrmap[cmd] == EHOSTDOWN)) { 1503 struct sockaddr_in sin; 1504 bzero(&sin, sizeof(sin)); 1505 sin.sin_len = sizeof(sin); 1506 sin.sin_family = AF_INET; 1507 sin.sin_port = th->th_sport; 1508 sin.sin_addr = ip->ip_src; 1509 syn_cache_unreach((struct sockaddr *)&sin, sa, th); 1510 } 1511 1512 /* XXX mapped address case */ 1513 } else 1514 in_pcbnotifyall(&tcbtable, satosin(sa)->sin_addr, errno, 1515 notify); 1516 return NULL; 1517 } 1518 1519 /* 1520 * When a source quence is received, we are being notifed of congestion. 1521 * Close the congestion window down to the Loss Window (one segment). 1522 * We will gradually open it again as we proceed. 1523 */ 1524 void 1525 tcp_quench(inp, errno) 1526 struct inpcb *inp; 1527 int errno; 1528 { 1529 struct tcpcb *tp = intotcpcb(inp); 1530 1531 if (tp) 1532 tp->snd_cwnd = tp->t_segsz; 1533 } 1534 #endif 1535 1536 #ifdef INET6 1537 void 1538 tcp6_quench(in6p, errno) 1539 struct in6pcb *in6p; 1540 int errno; 1541 { 1542 struct tcpcb *tp = in6totcpcb(in6p); 1543 1544 if (tp) 1545 tp->snd_cwnd = tp->t_segsz; 1546 } 1547 #endif 1548 1549 #ifdef INET 1550 /* 1551 * Path MTU Discovery handlers. 1552 */ 1553 void 1554 tcp_mtudisc_callback(faddr) 1555 struct in_addr faddr; 1556 { 1557 #ifdef INET6 1558 struct in6_addr in6; 1559 #endif 1560 1561 in_pcbnotifyall(&tcbtable, faddr, EMSGSIZE, tcp_mtudisc); 1562 #ifdef INET6 1563 memset(&in6, 0, sizeof(in6)); 1564 in6.s6_addr16[5] = 0xffff; 1565 memcpy(&in6.s6_addr32[3], &faddr, sizeof(struct in_addr)); 1566 tcp6_mtudisc_callback(&in6); 1567 #endif 1568 } 1569 1570 /* 1571 * On receipt of path MTU corrections, flush old route and replace it 1572 * with the new one. Retransmit all unacknowledged packets, to ensure 1573 * that all packets will be received. 1574 */ 1575 void 1576 tcp_mtudisc(inp, errno) 1577 struct inpcb *inp; 1578 int errno; 1579 { 1580 struct tcpcb *tp = intotcpcb(inp); 1581 struct rtentry *rt = in_pcbrtentry(inp); 1582 1583 if (tp != 0) { 1584 if (rt != 0) { 1585 /* 1586 * If this was not a host route, remove and realloc. 1587 */ 1588 if ((rt->rt_flags & RTF_HOST) == 0) { 1589 in_rtchange(inp, errno); 1590 if ((rt = in_pcbrtentry(inp)) == 0) 1591 return; 1592 } 1593 1594 /* 1595 * Slow start out of the error condition. We 1596 * use the MTU because we know it's smaller 1597 * than the previously transmitted segment. 1598 * 1599 * Note: This is more conservative than the 1600 * suggestion in draft-floyd-incr-init-win-03. 1601 */ 1602 if (rt->rt_rmx.rmx_mtu != 0) 1603 tp->snd_cwnd = 1604 TCP_INITIAL_WINDOW(tcp_init_win, 1605 rt->rt_rmx.rmx_mtu); 1606 } 1607 1608 /* 1609 * Resend unacknowledged packets. 1610 */ 1611 tp->snd_nxt = tp->snd_una; 1612 tcp_output(tp); 1613 } 1614 } 1615 #endif 1616 1617 #ifdef INET6 1618 /* 1619 * Path MTU Discovery handlers. 1620 */ 1621 void 1622 tcp6_mtudisc_callback(faddr) 1623 struct in6_addr *faddr; 1624 { 1625 struct sockaddr_in6 sin6; 1626 1627 bzero(&sin6, sizeof(sin6)); 1628 sin6.sin6_family = AF_INET6; 1629 sin6.sin6_len = sizeof(struct sockaddr_in6); 1630 sin6.sin6_addr = *faddr; 1631 (void) in6_pcbnotify(&tcb6, (struct sockaddr *)&sin6, 0, 1632 (struct sockaddr *)&sa6_any, 0, PRC_MSGSIZE, NULL, tcp6_mtudisc); 1633 } 1634 1635 void 1636 tcp6_mtudisc(in6p, errno) 1637 struct in6pcb *in6p; 1638 int errno; 1639 { 1640 struct tcpcb *tp = in6totcpcb(in6p); 1641 struct rtentry *rt = in6_pcbrtentry(in6p); 1642 1643 if (tp != 0) { 1644 if (rt != 0) { 1645 /* 1646 * If this was not a host route, remove and realloc. 1647 */ 1648 if ((rt->rt_flags & RTF_HOST) == 0) { 1649 in6_rtchange(in6p, errno); 1650 if ((rt = in6_pcbrtentry(in6p)) == 0) 1651 return; 1652 } 1653 1654 /* 1655 * Slow start out of the error condition. We 1656 * use the MTU because we know it's smaller 1657 * than the previously transmitted segment. 1658 * 1659 * Note: This is more conservative than the 1660 * suggestion in draft-floyd-incr-init-win-03. 1661 */ 1662 if (rt->rt_rmx.rmx_mtu != 0) 1663 tp->snd_cwnd = 1664 TCP_INITIAL_WINDOW(tcp_init_win, 1665 rt->rt_rmx.rmx_mtu); 1666 } 1667 1668 /* 1669 * Resend unacknowledged packets. 1670 */ 1671 tp->snd_nxt = tp->snd_una; 1672 tcp_output(tp); 1673 } 1674 } 1675 #endif /* INET6 */ 1676 1677 /* 1678 * Compute the MSS to advertise to the peer. Called only during 1679 * the 3-way handshake. If we are the server (peer initiated 1680 * connection), we are called with a pointer to the interface 1681 * on which the SYN packet arrived. If we are the client (we 1682 * initiated connection), we are called with a pointer to the 1683 * interface out which this connection should go. 1684 * 1685 * NOTE: Do not subtract IP option/extension header size nor IPsec 1686 * header size from MSS advertisement. MSS option must hold the maximum 1687 * segment size we can accept, so it must always be: 1688 * max(if mtu) - ip header - tcp header 1689 */ 1690 u_long 1691 tcp_mss_to_advertise(ifp, af) 1692 const struct ifnet *ifp; 1693 int af; 1694 { 1695 extern u_long in_maxmtu; 1696 u_long mss = 0; 1697 u_long hdrsiz; 1698 1699 /* 1700 * In order to avoid defeating path MTU discovery on the peer, 1701 * we advertise the max MTU of all attached networks as our MSS, 1702 * per RFC 1191, section 3.1. 1703 * 1704 * We provide the option to advertise just the MTU of 1705 * the interface on which we hope this connection will 1706 * be receiving. If we are responding to a SYN, we 1707 * will have a pretty good idea about this, but when 1708 * initiating a connection there is a bit more doubt. 1709 * 1710 * We also need to ensure that loopback has a large enough 1711 * MSS, as the loopback MTU is never included in in_maxmtu. 1712 */ 1713 1714 if (ifp != NULL) 1715 switch (af) { 1716 case AF_INET: 1717 mss = ifp->if_mtu; 1718 break; 1719 #ifdef INET6 1720 case AF_INET6: 1721 mss = IN6_LINKMTU(ifp); 1722 break; 1723 #endif 1724 } 1725 1726 if (tcp_mss_ifmtu == 0) 1727 switch (af) { 1728 case AF_INET: 1729 mss = max(in_maxmtu, mss); 1730 break; 1731 #ifdef INET6 1732 case AF_INET6: 1733 mss = max(in6_maxmtu, mss); 1734 break; 1735 #endif 1736 } 1737 1738 switch (af) { 1739 case AF_INET: 1740 hdrsiz = sizeof(struct ip); 1741 break; 1742 #ifdef INET6 1743 case AF_INET6: 1744 hdrsiz = sizeof(struct ip6_hdr); 1745 break; 1746 #endif 1747 default: 1748 hdrsiz = 0; 1749 break; 1750 } 1751 hdrsiz += sizeof(struct tcphdr); 1752 if (mss > hdrsiz) 1753 mss -= hdrsiz; 1754 1755 mss = max(tcp_mssdflt, mss); 1756 return (mss); 1757 } 1758 1759 /* 1760 * Set connection variables based on the peer's advertised MSS. 1761 * We are passed the TCPCB for the actual connection. If we 1762 * are the server, we are called by the compressed state engine 1763 * when the 3-way handshake is complete. If we are the client, 1764 * we are called when we receive the SYN,ACK from the server. 1765 * 1766 * NOTE: Our advertised MSS value must be initialized in the TCPCB 1767 * before this routine is called! 1768 */ 1769 void 1770 tcp_mss_from_peer(tp, offer) 1771 struct tcpcb *tp; 1772 int offer; 1773 { 1774 struct socket *so; 1775 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1776 struct rtentry *rt; 1777 #endif 1778 u_long bufsize; 1779 int mss; 1780 1781 #ifdef DIAGNOSTIC 1782 if (tp->t_inpcb && tp->t_in6pcb) 1783 panic("tcp_mss_from_peer: both t_inpcb and t_in6pcb are set"); 1784 #endif 1785 so = NULL; 1786 rt = NULL; 1787 #ifdef INET 1788 if (tp->t_inpcb) { 1789 so = tp->t_inpcb->inp_socket; 1790 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1791 rt = in_pcbrtentry(tp->t_inpcb); 1792 #endif 1793 } 1794 #endif 1795 #ifdef INET6 1796 if (tp->t_in6pcb) { 1797 so = tp->t_in6pcb->in6p_socket; 1798 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1799 rt = in6_pcbrtentry(tp->t_in6pcb); 1800 #endif 1801 } 1802 #endif 1803 1804 /* 1805 * As per RFC1122, use the default MSS value, unless they 1806 * sent us an offer. Do not accept offers less than 32 bytes. 1807 */ 1808 mss = tcp_mssdflt; 1809 if (offer) 1810 mss = offer; 1811 mss = max(mss, 32); /* sanity */ 1812 tp->t_peermss = mss; 1813 mss -= tcp_optlen(tp); 1814 #ifdef INET 1815 if (tp->t_inpcb) 1816 mss -= ip_optlen(tp->t_inpcb); 1817 #endif 1818 #ifdef INET6 1819 if (tp->t_in6pcb) 1820 mss -= ip6_optlen(tp->t_in6pcb); 1821 #endif 1822 1823 /* 1824 * If there's a pipesize, change the socket buffer to that size. 1825 * Make the socket buffer an integral number of MSS units. If 1826 * the MSS is larger than the socket buffer, artificially decrease 1827 * the MSS. 1828 */ 1829 #ifdef RTV_SPIPE 1830 if (rt != NULL && rt->rt_rmx.rmx_sendpipe != 0) 1831 bufsize = rt->rt_rmx.rmx_sendpipe; 1832 else 1833 #endif 1834 bufsize = so->so_snd.sb_hiwat; 1835 if (bufsize < mss) 1836 mss = bufsize; 1837 else { 1838 bufsize = roundup(bufsize, mss); 1839 if (bufsize > sb_max) 1840 bufsize = sb_max; 1841 (void) sbreserve(&so->so_snd, bufsize); 1842 } 1843 tp->t_segsz = mss; 1844 1845 #ifdef RTV_SSTHRESH 1846 if (rt != NULL && rt->rt_rmx.rmx_ssthresh) { 1847 /* 1848 * There's some sort of gateway or interface buffer 1849 * limit on the path. Use this to set the slow 1850 * start threshold, but set the threshold to no less 1851 * than 2 * MSS. 1852 */ 1853 tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh); 1854 } 1855 #endif 1856 } 1857 1858 /* 1859 * Processing necessary when a TCP connection is established. 1860 */ 1861 void 1862 tcp_established(tp) 1863 struct tcpcb *tp; 1864 { 1865 struct socket *so; 1866 #ifdef RTV_RPIPE 1867 struct rtentry *rt; 1868 #endif 1869 u_long bufsize; 1870 1871 #ifdef DIAGNOSTIC 1872 if (tp->t_inpcb && tp->t_in6pcb) 1873 panic("tcp_established: both t_inpcb and t_in6pcb are set"); 1874 #endif 1875 so = NULL; 1876 rt = NULL; 1877 #ifdef INET 1878 if (tp->t_inpcb) { 1879 so = tp->t_inpcb->inp_socket; 1880 #if defined(RTV_RPIPE) 1881 rt = in_pcbrtentry(tp->t_inpcb); 1882 #endif 1883 } 1884 #endif 1885 #ifdef INET6 1886 if (tp->t_in6pcb) { 1887 so = tp->t_in6pcb->in6p_socket; 1888 #if defined(RTV_RPIPE) 1889 rt = in6_pcbrtentry(tp->t_in6pcb); 1890 #endif 1891 } 1892 #endif 1893 1894 tp->t_state = TCPS_ESTABLISHED; 1895 TCP_TIMER_ARM(tp, TCPT_KEEP, tcp_keepidle); 1896 1897 #ifdef RTV_RPIPE 1898 if (rt != NULL && rt->rt_rmx.rmx_recvpipe != 0) 1899 bufsize = rt->rt_rmx.rmx_recvpipe; 1900 else 1901 #endif 1902 bufsize = so->so_rcv.sb_hiwat; 1903 if (bufsize > tp->t_ourmss) { 1904 bufsize = roundup(bufsize, tp->t_ourmss); 1905 if (bufsize > sb_max) 1906 bufsize = sb_max; 1907 (void) sbreserve(&so->so_rcv, bufsize); 1908 } 1909 } 1910 1911 /* 1912 * Check if there's an initial rtt or rttvar. Convert from the 1913 * route-table units to scaled multiples of the slow timeout timer. 1914 * Called only during the 3-way handshake. 1915 */ 1916 void 1917 tcp_rmx_rtt(tp) 1918 struct tcpcb *tp; 1919 { 1920 #ifdef RTV_RTT 1921 struct rtentry *rt = NULL; 1922 int rtt; 1923 1924 #ifdef DIAGNOSTIC 1925 if (tp->t_inpcb && tp->t_in6pcb) 1926 panic("tcp_rmx_rtt: both t_inpcb and t_in6pcb are set"); 1927 #endif 1928 #ifdef INET 1929 if (tp->t_inpcb) 1930 rt = in_pcbrtentry(tp->t_inpcb); 1931 #endif 1932 #ifdef INET6 1933 if (tp->t_in6pcb) 1934 rt = in6_pcbrtentry(tp->t_in6pcb); 1935 #endif 1936 if (rt == NULL) 1937 return; 1938 1939 if (tp->t_srtt == 0 && (rtt = rt->rt_rmx.rmx_rtt)) { 1940 /* 1941 * XXX The lock bit for MTU indicates that the value 1942 * is also a minimum value; this is subject to time. 1943 */ 1944 if (rt->rt_rmx.rmx_locks & RTV_RTT) 1945 TCPT_RANGESET(tp->t_rttmin, 1946 rtt / (RTM_RTTUNIT / PR_SLOWHZ), 1947 TCPTV_MIN, TCPTV_REXMTMAX); 1948 tp->t_srtt = rtt / 1949 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 1950 if (rt->rt_rmx.rmx_rttvar) { 1951 tp->t_rttvar = rt->rt_rmx.rmx_rttvar / 1952 ((RTM_RTTUNIT / PR_SLOWHZ) >> 1953 (TCP_RTTVAR_SHIFT + 2)); 1954 } else { 1955 /* Default variation is +- 1 rtt */ 1956 tp->t_rttvar = 1957 tp->t_srtt >> (TCP_RTT_SHIFT - TCP_RTTVAR_SHIFT); 1958 } 1959 TCPT_RANGESET(tp->t_rxtcur, 1960 ((tp->t_srtt >> 2) + tp->t_rttvar) >> (1 + 2), 1961 tp->t_rttmin, TCPTV_REXMTMAX); 1962 } 1963 #endif 1964 } 1965 1966 tcp_seq tcp_iss_seq = 0; /* tcp initial seq # */ 1967 #if NRND > 0 1968 u_int8_t tcp_iss_secret[16]; /* 128 bits; should be plenty */ 1969 #endif 1970 1971 /* 1972 * Get a new sequence value given a tcp control block 1973 */ 1974 tcp_seq 1975 tcp_new_iss(struct tcpcb *tp, tcp_seq addin) 1976 { 1977 1978 #ifdef INET 1979 if (tp->t_inpcb != NULL) { 1980 return (tcp_new_iss1(&tp->t_inpcb->inp_laddr, 1981 &tp->t_inpcb->inp_faddr, tp->t_inpcb->inp_lport, 1982 tp->t_inpcb->inp_fport, sizeof(tp->t_inpcb->inp_laddr), 1983 addin)); 1984 } 1985 #endif 1986 #ifdef INET6 1987 if (tp->t_in6pcb != NULL) { 1988 return (tcp_new_iss1(&tp->t_in6pcb->in6p_laddr, 1989 &tp->t_in6pcb->in6p_faddr, tp->t_in6pcb->in6p_lport, 1990 tp->t_in6pcb->in6p_fport, sizeof(tp->t_in6pcb->in6p_laddr), 1991 addin)); 1992 } 1993 #endif 1994 /* Not possible. */ 1995 panic("tcp_new_iss"); 1996 } 1997 1998 /* 1999 * This routine actually generates a new TCP initial sequence number. 2000 */ 2001 tcp_seq 2002 tcp_new_iss1(void *laddr, void *faddr, u_int16_t lport, u_int16_t fport, 2003 size_t addrsz, tcp_seq addin) 2004 { 2005 tcp_seq tcp_iss; 2006 2007 #if NRND > 0 2008 static int beenhere; 2009 2010 /* 2011 * If we haven't been here before, initialize our cryptographic 2012 * hash secret. 2013 */ 2014 if (beenhere == 0) { 2015 rnd_extract_data(tcp_iss_secret, sizeof(tcp_iss_secret), 2016 RND_EXTRACT_ANY); 2017 beenhere = 1; 2018 } 2019 2020 if (tcp_do_rfc1948) { 2021 MD5_CTX ctx; 2022 u_int8_t hash[16]; /* XXX MD5 knowledge */ 2023 2024 /* 2025 * Compute the base value of the ISS. It is a hash 2026 * of (saddr, sport, daddr, dport, secret). 2027 */ 2028 MD5Init(&ctx); 2029 2030 MD5Update(&ctx, (u_char *) laddr, addrsz); 2031 MD5Update(&ctx, (u_char *) &lport, sizeof(lport)); 2032 2033 MD5Update(&ctx, (u_char *) faddr, addrsz); 2034 MD5Update(&ctx, (u_char *) &fport, sizeof(fport)); 2035 2036 MD5Update(&ctx, tcp_iss_secret, sizeof(tcp_iss_secret)); 2037 2038 MD5Final(hash, &ctx); 2039 2040 memcpy(&tcp_iss, hash, sizeof(tcp_iss)); 2041 2042 /* 2043 * Now increment our "timer", and add it in to 2044 * the computed value. 2045 * 2046 * XXX Use `addin'? 2047 * XXX TCP_ISSINCR too large to use? 2048 */ 2049 tcp_iss_seq += TCP_ISSINCR; 2050 #ifdef TCPISS_DEBUG 2051 printf("ISS hash 0x%08x, ", tcp_iss); 2052 #endif 2053 tcp_iss += tcp_iss_seq + addin; 2054 #ifdef TCPISS_DEBUG 2055 printf("new ISS 0x%08x\n", tcp_iss); 2056 #endif 2057 } else 2058 #endif /* NRND > 0 */ 2059 { 2060 /* 2061 * Randomize. 2062 */ 2063 #if NRND > 0 2064 rnd_extract_data(&tcp_iss, sizeof(tcp_iss), RND_EXTRACT_ANY); 2065 #else 2066 tcp_iss = arc4random(); 2067 #endif 2068 2069 /* 2070 * If we were asked to add some amount to a known value, 2071 * we will take a random value obtained above, mask off 2072 * the upper bits, and add in the known value. We also 2073 * add in a constant to ensure that we are at least a 2074 * certain distance from the original value. 2075 * 2076 * This is used when an old connection is in timed wait 2077 * and we have a new one coming in, for instance. 2078 */ 2079 if (addin != 0) { 2080 #ifdef TCPISS_DEBUG 2081 printf("Random %08x, ", tcp_iss); 2082 #endif 2083 tcp_iss &= TCP_ISS_RANDOM_MASK; 2084 tcp_iss += addin + TCP_ISSINCR; 2085 #ifdef TCPISS_DEBUG 2086 printf("Old ISS %08x, ISS %08x\n", addin, tcp_iss); 2087 #endif 2088 } else { 2089 tcp_iss &= TCP_ISS_RANDOM_MASK; 2090 tcp_iss += tcp_iss_seq; 2091 tcp_iss_seq += TCP_ISSINCR; 2092 #ifdef TCPISS_DEBUG 2093 printf("ISS %08x\n", tcp_iss); 2094 #endif 2095 } 2096 } 2097 2098 if (tcp_compat_42) { 2099 /* 2100 * Limit it to the positive range for really old TCP 2101 * implementations. 2102 * Just AND off the top bit instead of checking if 2103 * is set first - saves a branch 50% of the time. 2104 */ 2105 tcp_iss &= 0x7fffffff; /* XXX */ 2106 } 2107 2108 return (tcp_iss); 2109 } 2110 2111 #ifdef IPSEC 2112 /* compute ESP/AH header size for TCP, including outer IP header. */ 2113 size_t 2114 ipsec4_hdrsiz_tcp(tp) 2115 struct tcpcb *tp; 2116 { 2117 struct inpcb *inp; 2118 size_t hdrsiz; 2119 2120 /* XXX mapped addr case (tp->t_in6pcb) */ 2121 if (!tp || !tp->t_template || !(inp = tp->t_inpcb)) 2122 return 0; 2123 switch (tp->t_family) { 2124 case AF_INET: 2125 /* XXX: should use currect direction. */ 2126 hdrsiz = ipsec4_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, inp); 2127 break; 2128 default: 2129 hdrsiz = 0; 2130 break; 2131 } 2132 2133 return hdrsiz; 2134 } 2135 2136 #ifdef INET6 2137 size_t 2138 ipsec6_hdrsiz_tcp(tp) 2139 struct tcpcb *tp; 2140 { 2141 struct in6pcb *in6p; 2142 size_t hdrsiz; 2143 2144 if (!tp || !tp->t_template || !(in6p = tp->t_in6pcb)) 2145 return 0; 2146 switch (tp->t_family) { 2147 case AF_INET6: 2148 /* XXX: should use currect direction. */ 2149 hdrsiz = ipsec6_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, in6p); 2150 break; 2151 case AF_INET: 2152 /* mapped address case - tricky */ 2153 default: 2154 hdrsiz = 0; 2155 break; 2156 } 2157 2158 return hdrsiz; 2159 } 2160 #endif 2161 #endif /*IPSEC*/ 2162 2163 /* 2164 * Determine the length of the TCP options for this connection. 2165 * 2166 * XXX: What do we do for SACK, when we add that? Just reserve 2167 * all of the space? Otherwise we can't exactly be incrementing 2168 * cwnd by an amount that varies depending on the amount we last 2169 * had to SACK! 2170 */ 2171 2172 u_int 2173 tcp_optlen(tp) 2174 struct tcpcb *tp; 2175 { 2176 if ((tp->t_flags & (TF_REQ_TSTMP|TF_RCVD_TSTMP|TF_NOOPT)) == 2177 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 2178 return TCPOLEN_TSTAMP_APPA; 2179 else 2180 return 0; 2181 } 2182
Indexes created Mon Sep 22 05:09:51 GMT 2025