1 /* $OpenBSD: tcp_subr.c,v 1.190 2022/11/07 11:22:55 yasuoka Exp $ */ 2 /* $NetBSD: tcp_subr.c,v 1.22 1996/02/13 23:44:00 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1988, 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)COPYRIGHT 1.1 (NRL) 17 January 1995 33 * 34 * NRL grants permission for redistribution and use in source and binary 35 * forms, with or without modification, of the software and documentation 36 * created at NRL provided that the following conditions are met: 37 * 38 * 1. Redistributions of source code must retain the above copyright 39 * notice, this list of conditions and the following disclaimer. 40 * 2. Redistributions in binary form must reproduce the above copyright 41 * notice, this list of conditions and the following disclaimer in the 42 * documentation and/or other materials provided with the distribution. 43 * 3. All advertising materials mentioning features or use of this software 44 * must display the following acknowledgements: 45 * This product includes software developed by the University of 46 * California, Berkeley and its contributors. 47 * This product includes software developed at the Information 48 * Technology Division, US Naval Research Laboratory. 49 * 4. Neither the name of the NRL nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS 54 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 55 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 56 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL NRL OR 57 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 58 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 59 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 60 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 61 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 62 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 63 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 64 * 65 * The views and conclusions contained in the software and documentation 66 * are those of the authors and should not be interpreted as representing 67 * official policies, either expressed or implied, of the US Naval 68 * Research Laboratory (NRL). 69 */ 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/mbuf.h> 74 #include <sys/mutex.h> 75 #include <sys/socket.h> 76 #include <sys/socketvar.h> 77 #include <sys/timeout.h> 78 #include <sys/protosw.h> 79 #include <sys/kernel.h> 80 #include <sys/pool.h> 81 82 #include <net/route.h> 83 84 #include <netinet/in.h> 85 #include <netinet/ip.h> 86 #include <netinet/in_pcb.h> 87 #include <netinet/ip_var.h> 88 #include <netinet/ip_icmp.h> 89 #include <netinet/tcp.h> 90 #include <netinet/tcp_fsm.h> 91 #include <netinet/tcp_seq.h> 92 #include <netinet/tcp_timer.h> 93 #include <netinet/tcp_var.h> 94 95 #ifdef INET6 96 #include <netinet6/ip6protosw.h> 97 #endif /* INET6 */ 98 99 #include <crypto/md5.h> 100 #include <crypto/sha2.h> 101 102 /* 103 * Locks used to protect struct members in this file: 104 * I immutable after creation 105 * T tcp_timer_mtx global tcp timer data structures 106 */ 107 108 struct mutex tcp_timer_mtx = MUTEX_INITIALIZER(IPL_SOFTNET); 109 110 /* patchable/settable parameters for tcp */ 111 int tcp_mssdflt = TCP_MSS; 112 int tcp_rttdflt = TCPTV_SRTTDFLT; 113 114 /* values controllable via sysctl */ 115 int tcp_do_rfc1323 = 1; 116 int tcp_do_sack = 1; /* RFC 2018 selective ACKs */ 117 int tcp_ack_on_push = 0; /* set to enable immediate ACK-on-PUSH */ 118 #ifdef TCP_ECN 119 int tcp_do_ecn = 0; /* RFC3168 ECN enabled/disabled? */ 120 #endif 121 int tcp_do_rfc3390 = 2; /* Increase TCP's Initial Window to 10*mss */ 122 123 #ifndef TCB_INITIAL_HASH_SIZE 124 #define TCB_INITIAL_HASH_SIZE 128 125 #endif 126 127 int tcp_reass_limit = NMBCLUSTERS / 8; /* hardlimit for tcpqe_pool */ 128 int tcp_sackhole_limit = 32*1024; /* hardlimit for sackhl_pool */ 129 130 struct pool tcpcb_pool; 131 struct pool tcpqe_pool; 132 struct pool sackhl_pool; 133 134 struct cpumem *tcpcounters; /* tcp statistics */ 135 136 u_char tcp_secret[16]; /* [I] */ 137 SHA2_CTX tcp_secret_ctx; /* [I] */ 138 tcp_seq tcp_iss; /* [T] updated by timer and connection */ 139 140 /* 141 * Tcp initialization 142 */ 143 void 144 tcp_init(void) 145 { 146 tcp_iss = 1; /* wrong */ 147 pool_init(&tcpcb_pool, sizeof(struct tcpcb), 0, IPL_SOFTNET, 0, 148 "tcpcb", NULL); 149 pool_init(&tcpqe_pool, sizeof(struct tcpqent), 0, IPL_SOFTNET, 0, 150 "tcpqe", NULL); 151 pool_sethardlimit(&tcpqe_pool, tcp_reass_limit, NULL, 0); 152 pool_init(&sackhl_pool, sizeof(struct sackhole), 0, IPL_SOFTNET, 0, 153 "sackhl", NULL); 154 pool_sethardlimit(&sackhl_pool, tcp_sackhole_limit, NULL, 0); 155 in_pcbinit(&tcbtable, TCB_INITIAL_HASH_SIZE); 156 tcpcounters = counters_alloc(tcps_ncounters); 157 158 arc4random_buf(tcp_secret, sizeof(tcp_secret)); 159 SHA512Init(&tcp_secret_ctx); 160 SHA512Update(&tcp_secret_ctx, tcp_secret, sizeof(tcp_secret)); 161 162 #ifdef INET6 163 /* 164 * Since sizeof(struct ip6_hdr) > sizeof(struct ip), we 165 * do max length checks/computations only on the former. 166 */ 167 if (max_protohdr < (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))) 168 max_protohdr = (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)); 169 if ((max_linkhdr + sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) > 170 MHLEN) 171 panic("tcp_init"); 172 173 icmp6_mtudisc_callback_register(tcp6_mtudisc_callback); 174 #endif /* INET6 */ 175 176 /* Initialize the compressed state engine. */ 177 syn_cache_init(); 178 179 /* Initialize timer state. */ 180 tcp_timer_init(); 181 } 182 183 /* 184 * Create template to be used to send tcp packets on a connection. 185 * Call after host entry created, allocates an mbuf and fills 186 * in a skeletal tcp/ip header, minimizing the amount of work 187 * necessary when the connection is used. 188 * 189 * To support IPv6 in addition to IPv4 and considering that the sizes of 190 * the IPv4 and IPv6 headers are not the same, we now use a separate pointer 191 * for the TCP header. Also, we made the former tcpiphdr header pointer 192 * into just an IP overlay pointer, with casting as appropriate for v6. rja 193 */ 194 struct mbuf * 195 tcp_template(struct tcpcb *tp) 196 { 197 struct inpcb *inp = tp->t_inpcb; 198 struct mbuf *m; 199 struct tcphdr *th; 200 201 CTASSERT(sizeof(struct ip) + sizeof(struct tcphdr) <= MHLEN); 202 CTASSERT(sizeof(struct ip6_hdr) + sizeof(struct tcphdr) <= MHLEN); 203 204 if ((m = tp->t_template) == 0) { 205 m = m_get(M_DONTWAIT, MT_HEADER); 206 if (m == NULL) 207 return (0); 208 209 switch (tp->pf) { 210 case 0: /*default to PF_INET*/ 211 case AF_INET: 212 m->m_len = sizeof(struct ip); 213 break; 214 #ifdef INET6 215 case AF_INET6: 216 m->m_len = sizeof(struct ip6_hdr); 217 break; 218 #endif /* INET6 */ 219 } 220 m->m_len += sizeof (struct tcphdr); 221 } 222 223 switch(tp->pf) { 224 case AF_INET: 225 { 226 struct ipovly *ipovly; 227 228 ipovly = mtod(m, struct ipovly *); 229 230 bzero(ipovly->ih_x1, sizeof ipovly->ih_x1); 231 ipovly->ih_pr = IPPROTO_TCP; 232 ipovly->ih_len = htons(sizeof (struct tcphdr)); 233 ipovly->ih_src = inp->inp_laddr; 234 ipovly->ih_dst = inp->inp_faddr; 235 236 th = (struct tcphdr *)(mtod(m, caddr_t) + 237 sizeof(struct ip)); 238 } 239 break; 240 #ifdef INET6 241 case AF_INET6: 242 { 243 struct ip6_hdr *ip6; 244 245 ip6 = mtod(m, struct ip6_hdr *); 246 247 ip6->ip6_src = inp->inp_laddr6; 248 ip6->ip6_dst = inp->inp_faddr6; 249 ip6->ip6_flow = htonl(0x60000000) | 250 (inp->inp_flowinfo & IPV6_FLOWLABEL_MASK); 251 252 ip6->ip6_nxt = IPPROTO_TCP; 253 ip6->ip6_plen = htons(sizeof(struct tcphdr)); /*XXX*/ 254 ip6->ip6_hlim = in6_selecthlim(inp); /*XXX*/ 255 256 th = (struct tcphdr *)(mtod(m, caddr_t) + 257 sizeof(struct ip6_hdr)); 258 } 259 break; 260 #endif /* INET6 */ 261 } 262 263 th->th_sport = inp->inp_lport; 264 th->th_dport = inp->inp_fport; 265 th->th_seq = 0; 266 th->th_ack = 0; 267 th->th_x2 = 0; 268 th->th_off = 5; 269 th->th_flags = 0; 270 th->th_win = 0; 271 th->th_urp = 0; 272 th->th_sum = 0; 273 return (m); 274 } 275 276 /* 277 * Send a single message to the TCP at address specified by 278 * the given TCP/IP header. If m == 0, then we make a copy 279 * of the tcpiphdr at ti and send directly to the addressed host. 280 * This is used to force keep alive messages out using the TCP 281 * template for a connection tp->t_template. If flags are given 282 * then we send a message back to the TCP which originated the 283 * segment ti, and discard the mbuf containing it and any other 284 * attached mbufs. 285 * 286 * In any case the ack and sequence number of the transmitted 287 * segment are as specified by the parameters. 288 */ 289 void 290 tcp_respond(struct tcpcb *tp, caddr_t template, struct tcphdr *th0, 291 tcp_seq ack, tcp_seq seq, int flags, u_int rtableid, uint32_t now) 292 { 293 int tlen; 294 int win = 0; 295 struct mbuf *m = NULL; 296 struct tcphdr *th; 297 struct ip *ip; 298 #ifdef INET6 299 struct ip6_hdr *ip6; 300 #endif 301 int af; /* af on wire */ 302 303 if (tp) { 304 struct socket *so = tp->t_inpcb->inp_socket; 305 win = sbspace(so, &so->so_rcv); 306 /* 307 * If this is called with an unconnected 308 * socket/tp/pcb (tp->pf is 0), we lose. 309 */ 310 af = tp->pf; 311 } else 312 af = (((struct ip *)template)->ip_v == 6) ? AF_INET6 : AF_INET; 313 314 m = m_gethdr(M_DONTWAIT, MT_HEADER); 315 if (m == NULL) 316 return; 317 m->m_data += max_linkhdr; 318 tlen = 0; 319 320 #define xchg(a,b,type) do { type t; t=a; a=b; b=t; } while (0) 321 switch (af) { 322 #ifdef INET6 323 case AF_INET6: 324 ip6 = mtod(m, struct ip6_hdr *); 325 th = (struct tcphdr *)(ip6 + 1); 326 tlen = sizeof(*ip6) + sizeof(*th); 327 if (th0) { 328 bcopy(template, ip6, sizeof(*ip6)); 329 bcopy(th0, th, sizeof(*th)); 330 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 331 } else { 332 bcopy(template, ip6, tlen); 333 } 334 break; 335 #endif /* INET6 */ 336 case AF_INET: 337 ip = mtod(m, struct ip *); 338 th = (struct tcphdr *)(ip + 1); 339 tlen = sizeof(*ip) + sizeof(*th); 340 if (th0) { 341 bcopy(template, ip, sizeof(*ip)); 342 bcopy(th0, th, sizeof(*th)); 343 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, u_int32_t); 344 } else { 345 bcopy(template, ip, tlen); 346 } 347 break; 348 } 349 if (th0) 350 xchg(th->th_dport, th->th_sport, u_int16_t); 351 else 352 flags = TH_ACK; 353 #undef xchg 354 355 th->th_seq = htonl(seq); 356 th->th_ack = htonl(ack); 357 th->th_x2 = 0; 358 th->th_off = sizeof (struct tcphdr) >> 2; 359 th->th_flags = flags; 360 if (tp) 361 win >>= tp->rcv_scale; 362 if (win > TCP_MAXWIN) 363 win = TCP_MAXWIN; 364 th->th_win = htons((u_int16_t)win); 365 th->th_urp = 0; 366 367 if (tp && (tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP && 368 (flags & TH_RST) == 0 && (tp->t_flags & TF_RCVD_TSTMP)) { 369 u_int32_t *lp = (u_int32_t *)(th + 1); 370 /* Form timestamp option as shown in appendix A of RFC 1323. */ 371 *lp++ = htonl(TCPOPT_TSTAMP_HDR); 372 *lp++ = htonl(now + tp->ts_modulate); 373 *lp = htonl(tp->ts_recent); 374 tlen += TCPOLEN_TSTAMP_APPA; 375 th->th_off = (sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2; 376 } 377 378 m->m_len = tlen; 379 m->m_pkthdr.len = tlen; 380 m->m_pkthdr.ph_ifidx = 0; 381 m->m_pkthdr.csum_flags |= M_TCP_CSUM_OUT; 382 383 /* force routing table */ 384 if (tp) 385 m->m_pkthdr.ph_rtableid = tp->t_inpcb->inp_rtableid; 386 else 387 m->m_pkthdr.ph_rtableid = rtableid; 388 389 switch (af) { 390 #ifdef INET6 391 case AF_INET6: 392 ip6->ip6_flow = htonl(0x60000000); 393 ip6->ip6_nxt = IPPROTO_TCP; 394 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL); /*XXX*/ 395 ip6->ip6_plen = tlen - sizeof(struct ip6_hdr); 396 ip6->ip6_plen = htons(ip6->ip6_plen); 397 ip6_output(m, tp ? tp->t_inpcb->inp_outputopts6 : NULL, 398 tp ? &tp->t_inpcb->inp_route6 : NULL, 399 0, NULL, 400 tp ? tp->t_inpcb : NULL); 401 break; 402 #endif /* INET6 */ 403 case AF_INET: 404 ip->ip_len = htons(tlen); 405 ip->ip_ttl = ip_defttl; 406 ip->ip_tos = 0; 407 ip_output(m, NULL, 408 tp ? &tp->t_inpcb->inp_route : NULL, 409 ip_mtudisc ? IP_MTUDISC : 0, NULL, 410 tp ? tp->t_inpcb : NULL, 0); 411 break; 412 } 413 } 414 415 /* 416 * Create a new TCP control block, making an 417 * empty reassembly queue and hooking it to the argument 418 * protocol control block. 419 */ 420 struct tcpcb * 421 tcp_newtcpcb(struct inpcb *inp, int wait) 422 { 423 struct tcpcb *tp; 424 int i; 425 426 tp = pool_get(&tcpcb_pool, (wait == M_WAIT ? PR_WAITOK : PR_NOWAIT) | 427 PR_ZERO); 428 if (tp == NULL) 429 return (NULL); 430 TAILQ_INIT(&tp->t_segq); 431 tp->t_maxseg = tcp_mssdflt; 432 tp->t_maxopd = 0; 433 434 for (i = 0; i < TCPT_NTIMERS; i++) 435 TCP_TIMER_INIT(tp, i); 436 437 tp->sack_enable = tcp_do_sack; 438 tp->t_flags = tcp_do_rfc1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0; 439 tp->t_inpcb = inp; 440 /* 441 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 442 * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives 443 * reasonable initial retransmit time. 444 */ 445 tp->t_srtt = TCPTV_SRTTBASE; 446 tp->t_rttvar = tcp_rttdflt << 447 (TCP_RTTVAR_SHIFT + TCP_RTT_BASE_SHIFT - 1); 448 tp->t_rttmin = TCPTV_MIN; 449 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), 450 TCPTV_MIN, TCPTV_REXMTMAX); 451 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 452 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 453 454 tp->t_pmtud_mtu_sent = 0; 455 tp->t_pmtud_mss_acked = 0; 456 457 #ifdef INET6 458 /* we disallow IPv4 mapped address completely. */ 459 if ((inp->inp_flags & INP_IPV6) == 0) 460 tp->pf = PF_INET; 461 else 462 tp->pf = PF_INET6; 463 #else 464 tp->pf = PF_INET; 465 #endif 466 467 #ifdef INET6 468 if (inp->inp_flags & INP_IPV6) 469 inp->inp_ipv6.ip6_hlim = ip6_defhlim; 470 else 471 #endif /* INET6 */ 472 inp->inp_ip.ip_ttl = ip_defttl; 473 474 inp->inp_ppcb = (caddr_t)tp; 475 return (tp); 476 } 477 478 /* 479 * Drop a TCP connection, reporting 480 * the specified error. If connection is synchronized, 481 * then send a RST to peer. 482 */ 483 struct tcpcb * 484 tcp_drop(struct tcpcb *tp, int errno) 485 { 486 struct socket *so = tp->t_inpcb->inp_socket; 487 488 if (TCPS_HAVERCVDSYN(tp->t_state)) { 489 tp->t_state = TCPS_CLOSED; 490 (void) tcp_output(tp); 491 tcpstat_inc(tcps_drops); 492 } else 493 tcpstat_inc(tcps_conndrops); 494 if (errno == ETIMEDOUT && tp->t_softerror) 495 errno = tp->t_softerror; 496 so->so_error = errno; 497 return (tcp_close(tp)); 498 } 499 500 /* 501 * Close a TCP control block: 502 * discard all space held by the tcp 503 * discard internet protocol block 504 * wake up any sleepers 505 */ 506 struct tcpcb * 507 tcp_close(struct tcpcb *tp) 508 { 509 struct inpcb *inp = tp->t_inpcb; 510 struct socket *so = inp->inp_socket; 511 struct sackhole *p, *q; 512 513 /* free the reassembly queue, if any */ 514 tcp_freeq(tp); 515 516 tcp_canceltimers(tp); 517 syn_cache_cleanup(tp); 518 519 /* Free SACK holes. */ 520 q = p = tp->snd_holes; 521 while (p != 0) { 522 q = p->next; 523 pool_put(&sackhl_pool, p); 524 p = q; 525 } 526 527 m_free(tp->t_template); 528 /* Free tcpcb after all pending timers have been run. */ 529 TCP_TIMER_ARM(tp, TCPT_REAPER, 1); 530 531 inp->inp_ppcb = NULL; 532 soisdisconnected(so); 533 in_pcbdetach(inp); 534 return (NULL); 535 } 536 537 int 538 tcp_freeq(struct tcpcb *tp) 539 { 540 struct tcpqent *qe; 541 int rv = 0; 542 543 while ((qe = TAILQ_FIRST(&tp->t_segq)) != NULL) { 544 TAILQ_REMOVE(&tp->t_segq, qe, tcpqe_q); 545 m_freem(qe->tcpqe_m); 546 pool_put(&tcpqe_pool, qe); 547 rv = 1; 548 } 549 return (rv); 550 } 551 552 /* 553 * Compute proper scaling value for receiver window from buffer space 554 */ 555 556 void 557 tcp_rscale(struct tcpcb *tp, u_long hiwat) 558 { 559 tp->request_r_scale = 0; 560 while (tp->request_r_scale < TCP_MAX_WINSHIFT && 561 TCP_MAXWIN << tp->request_r_scale < hiwat) 562 tp->request_r_scale++; 563 } 564 565 /* 566 * Notify a tcp user of an asynchronous error; 567 * store error as soft error, but wake up user 568 * (for now, won't do anything until can select for soft error). 569 */ 570 void 571 tcp_notify(struct inpcb *inp, int error) 572 { 573 struct tcpcb *tp = intotcpcb(inp); 574 struct socket *so = inp->inp_socket; 575 576 /* 577 * Ignore some errors if we are hooked up. 578 * If connection hasn't completed, has retransmitted several times, 579 * and receives a second error, give up now. This is better 580 * than waiting a long time to establish a connection that 581 * can never complete. 582 */ 583 if (tp->t_state == TCPS_ESTABLISHED && 584 (error == EHOSTUNREACH || error == ENETUNREACH || 585 error == EHOSTDOWN)) { 586 return; 587 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 588 tp->t_rxtshift > 3 && tp->t_softerror) 589 so->so_error = error; 590 else 591 tp->t_softerror = error; 592 wakeup((caddr_t) &so->so_timeo); 593 sorwakeup(so); 594 sowwakeup(so); 595 } 596 597 #ifdef INET6 598 void 599 tcp6_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *d) 600 { 601 struct tcphdr th; 602 struct tcpcb *tp; 603 void (*notify)(struct inpcb *, int) = tcp_notify; 604 struct ip6_hdr *ip6; 605 const struct sockaddr_in6 *sa6_src = NULL; 606 struct sockaddr_in6 *sa6 = satosin6(sa); 607 struct inpcb *inp; 608 struct mbuf *m; 609 tcp_seq seq; 610 int off; 611 struct { 612 u_int16_t th_sport; 613 u_int16_t th_dport; 614 u_int32_t th_seq; 615 } *thp; 616 617 CTASSERT(sizeof(*thp) <= sizeof(th)); 618 if (sa->sa_family != AF_INET6 || 619 sa->sa_len != sizeof(struct sockaddr_in6) || 620 IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) || 621 IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr)) 622 return; 623 if ((unsigned)cmd >= PRC_NCMDS) 624 return; 625 else if (cmd == PRC_QUENCH) { 626 /* 627 * Don't honor ICMP Source Quench messages meant for 628 * TCP connections. 629 */ 630 /* XXX there's no PRC_QUENCH in IPv6 */ 631 return; 632 } else if (PRC_IS_REDIRECT(cmd)) 633 notify = in_rtchange, d = NULL; 634 else if (cmd == PRC_MSGSIZE) 635 ; /* special code is present, see below */ 636 else if (cmd == PRC_HOSTDEAD) 637 d = NULL; 638 else if (inet6ctlerrmap[cmd] == 0) 639 return; 640 641 /* if the parameter is from icmp6, decode it. */ 642 if (d != NULL) { 643 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 644 m = ip6cp->ip6c_m; 645 ip6 = ip6cp->ip6c_ip6; 646 off = ip6cp->ip6c_off; 647 sa6_src = ip6cp->ip6c_src; 648 } else { 649 m = NULL; 650 ip6 = NULL; 651 sa6_src = &sa6_any; 652 } 653 654 if (ip6) { 655 /* 656 * XXX: We assume that when ip6 is non NULL, 657 * M and OFF are valid. 658 */ 659 660 /* check if we can safely examine src and dst ports */ 661 if (m->m_pkthdr.len < off + sizeof(*thp)) 662 return; 663 664 bzero(&th, sizeof(th)); 665 m_copydata(m, off, sizeof(*thp), &th); 666 667 /* 668 * Check to see if we have a valid TCP connection 669 * corresponding to the address in the ICMPv6 message 670 * payload. 671 */ 672 inp = in6_pcblookup(&tcbtable, &sa6->sin6_addr, 673 th.th_dport, &sa6_src->sin6_addr, th.th_sport, rdomain); 674 if (cmd == PRC_MSGSIZE) { 675 /* 676 * Depending on the value of "valid" and routing table 677 * size (mtudisc_{hi,lo}wat), we will: 678 * - recalculate the new MTU and create the 679 * corresponding routing entry, or 680 * - ignore the MTU change notification. 681 */ 682 icmp6_mtudisc_update((struct ip6ctlparam *)d, 683 inp != NULL); 684 in_pcbunref(inp); 685 return; 686 } 687 if (inp) { 688 seq = ntohl(th.th_seq); 689 if (inp->inp_socket && 690 (tp = intotcpcb(inp)) && 691 SEQ_GEQ(seq, tp->snd_una) && 692 SEQ_LT(seq, tp->snd_max)) 693 notify(inp, inet6ctlerrmap[cmd]); 694 } else if (inet6ctlerrmap[cmd] == EHOSTUNREACH || 695 inet6ctlerrmap[cmd] == ENETUNREACH || 696 inet6ctlerrmap[cmd] == EHOSTDOWN) 697 syn_cache_unreach((struct sockaddr *)sa6_src, 698 sa, &th, rdomain); 699 in_pcbunref(inp); 700 } else { 701 in6_pcbnotify(&tcbtable, sa6, 0, 702 sa6_src, 0, rdomain, cmd, NULL, notify); 703 } 704 } 705 #endif 706 707 void 708 tcp_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) 709 { 710 struct ip *ip = v; 711 struct tcphdr *th; 712 struct tcpcb *tp; 713 struct inpcb *inp; 714 struct in_addr faddr; 715 tcp_seq seq; 716 u_int mtu; 717 void (*notify)(struct inpcb *, int) = tcp_notify; 718 int errno; 719 720 if (sa->sa_family != AF_INET) 721 return; 722 faddr = satosin(sa)->sin_addr; 723 if (faddr.s_addr == INADDR_ANY) 724 return; 725 726 if ((unsigned)cmd >= PRC_NCMDS) 727 return; 728 errno = inetctlerrmap[cmd]; 729 if (cmd == PRC_QUENCH) 730 /* 731 * Don't honor ICMP Source Quench messages meant for 732 * TCP connections. 733 */ 734 return; 735 else if (PRC_IS_REDIRECT(cmd)) 736 notify = in_rtchange, ip = 0; 737 else if (cmd == PRC_MSGSIZE && ip_mtudisc && ip) { 738 /* 739 * Verify that the packet in the icmp payload refers 740 * to an existing TCP connection. 741 */ 742 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 743 seq = ntohl(th->th_seq); 744 inp = in_pcblookup(&tcbtable, 745 ip->ip_dst, th->th_dport, ip->ip_src, th->th_sport, 746 rdomain); 747 if (inp && (tp = intotcpcb(inp)) && 748 SEQ_GEQ(seq, tp->snd_una) && 749 SEQ_LT(seq, tp->snd_max)) { 750 struct icmp *icp; 751 icp = (struct icmp *)((caddr_t)ip - 752 offsetof(struct icmp, icmp_ip)); 753 754 /* 755 * If the ICMP message advertises a Next-Hop MTU 756 * equal or larger than the maximum packet size we have 757 * ever sent, drop the message. 758 */ 759 mtu = (u_int)ntohs(icp->icmp_nextmtu); 760 if (mtu >= tp->t_pmtud_mtu_sent) { 761 in_pcbunref(inp); 762 return; 763 } 764 if (mtu >= tcp_hdrsz(tp) + tp->t_pmtud_mss_acked) { 765 /* 766 * Calculate new MTU, and create corresponding 767 * route (traditional PMTUD). 768 */ 769 tp->t_flags &= ~TF_PMTUD_PEND; 770 icmp_mtudisc(icp, inp->inp_rtableid); 771 } else { 772 /* 773 * Record the information got in the ICMP 774 * message; act on it later. 775 * If we had already recorded an ICMP message, 776 * replace the old one only if the new message 777 * refers to an older TCP segment 778 */ 779 if (tp->t_flags & TF_PMTUD_PEND) { 780 if (SEQ_LT(tp->t_pmtud_th_seq, seq)) { 781 in_pcbunref(inp); 782 return; 783 } 784 } else 785 tp->t_flags |= TF_PMTUD_PEND; 786 tp->t_pmtud_th_seq = seq; 787 tp->t_pmtud_nextmtu = icp->icmp_nextmtu; 788 tp->t_pmtud_ip_len = icp->icmp_ip.ip_len; 789 tp->t_pmtud_ip_hl = icp->icmp_ip.ip_hl; 790 in_pcbunref(inp); 791 return; 792 } 793 } else { 794 /* ignore if we don't have a matching connection */ 795 in_pcbunref(inp); 796 return; 797 } 798 in_pcbunref(inp); 799 notify = tcp_mtudisc, ip = 0; 800 } else if (cmd == PRC_MTUINC) 801 notify = tcp_mtudisc_increase, ip = 0; 802 else if (cmd == PRC_HOSTDEAD) 803 ip = 0; 804 else if (errno == 0) 805 return; 806 807 if (ip) { 808 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 809 inp = in_pcblookup(&tcbtable, 810 ip->ip_dst, th->th_dport, ip->ip_src, th->th_sport, 811 rdomain); 812 if (inp) { 813 seq = ntohl(th->th_seq); 814 if (inp->inp_socket && 815 (tp = intotcpcb(inp)) && 816 SEQ_GEQ(seq, tp->snd_una) && 817 SEQ_LT(seq, tp->snd_max)) 818 notify(inp, errno); 819 } else if (inetctlerrmap[cmd] == EHOSTUNREACH || 820 inetctlerrmap[cmd] == ENETUNREACH || 821 inetctlerrmap[cmd] == EHOSTDOWN) { 822 struct sockaddr_in sin; 823 824 bzero(&sin, sizeof(sin)); 825 sin.sin_len = sizeof(sin); 826 sin.sin_family = AF_INET; 827 sin.sin_port = th->th_sport; 828 sin.sin_addr = ip->ip_src; 829 syn_cache_unreach(sintosa(&sin), sa, th, rdomain); 830 } 831 in_pcbunref(inp); 832 } else 833 in_pcbnotifyall(&tcbtable, sa, rdomain, errno, notify); 834 } 835 836 837 #ifdef INET6 838 /* 839 * Path MTU Discovery handlers. 840 */ 841 void 842 tcp6_mtudisc_callback(struct sockaddr_in6 *sin6, u_int rdomain) 843 { 844 in6_pcbnotify(&tcbtable, sin6, 0, 845 &sa6_any, 0, rdomain, PRC_MSGSIZE, NULL, tcp_mtudisc); 846 } 847 #endif /* INET6 */ 848 849 /* 850 * On receipt of path MTU corrections, flush old route and replace it 851 * with the new one. Retransmit all unacknowledged packets, to ensure 852 * that all packets will be received. 853 */ 854 void 855 tcp_mtudisc(struct inpcb *inp, int errno) 856 { 857 struct tcpcb *tp = intotcpcb(inp); 858 struct rtentry *rt; 859 int orig_maxseg, change = 0; 860 861 if (tp == NULL) 862 return; 863 orig_maxseg = tp->t_maxseg; 864 865 rt = in_pcbrtentry(inp); 866 if (rt != NULL) { 867 unsigned int orig_mtulock = (rt->rt_locks & RTV_MTU); 868 869 /* 870 * If this was not a host route, remove and realloc. 871 */ 872 if ((rt->rt_flags & RTF_HOST) == 0) { 873 in_rtchange(inp, errno); 874 if ((rt = in_pcbrtentry(inp)) == NULL) 875 return; 876 } 877 if (orig_mtulock < (rt->rt_locks & RTV_MTU)) 878 change = 1; 879 } 880 tcp_mss(tp, -1); 881 if (orig_maxseg > tp->t_maxseg) 882 change = 1; 883 884 /* 885 * Resend unacknowledged packets 886 */ 887 tp->snd_nxt = tp->snd_una; 888 if (change || errno > 0) 889 tcp_output(tp); 890 } 891 892 void 893 tcp_mtudisc_increase(struct inpcb *inp, int errno) 894 { 895 struct tcpcb *tp = intotcpcb(inp); 896 struct rtentry *rt = in_pcbrtentry(inp); 897 898 if (tp != 0 && rt != 0) { 899 /* 900 * If this was a host route, remove and realloc. 901 */ 902 if (rt->rt_flags & RTF_HOST) 903 in_rtchange(inp, errno); 904 905 /* also takes care of congestion window */ 906 tcp_mss(tp, -1); 907 } 908 } 909 910 /* 911 * Generate new ISNs with a method based on RFC1948 912 */ 913 #define TCP_ISS_CONN_INC 4096 914 915 void 916 tcp_set_iss_tsm(struct tcpcb *tp) 917 { 918 SHA2_CTX ctx; 919 union { 920 uint8_t bytes[SHA512_DIGEST_LENGTH]; 921 uint32_t words[2]; 922 } digest; 923 u_int rdomain = rtable_l2(tp->t_inpcb->inp_rtableid); 924 tcp_seq iss; 925 926 mtx_enter(&tcp_timer_mtx); 927 tcp_iss += TCP_ISS_CONN_INC; 928 iss = tcp_iss; 929 mtx_leave(&tcp_timer_mtx); 930 931 ctx = tcp_secret_ctx; 932 SHA512Update(&ctx, &rdomain, sizeof(rdomain)); 933 SHA512Update(&ctx, &tp->t_inpcb->inp_lport, sizeof(u_short)); 934 SHA512Update(&ctx, &tp->t_inpcb->inp_fport, sizeof(u_short)); 935 if (tp->pf == AF_INET6) { 936 SHA512Update(&ctx, &tp->t_inpcb->inp_laddr6, 937 sizeof(struct in6_addr)); 938 SHA512Update(&ctx, &tp->t_inpcb->inp_faddr6, 939 sizeof(struct in6_addr)); 940 } else { 941 SHA512Update(&ctx, &tp->t_inpcb->inp_laddr, 942 sizeof(struct in_addr)); 943 SHA512Update(&ctx, &tp->t_inpcb->inp_faddr, 944 sizeof(struct in_addr)); 945 } 946 SHA512Final(digest.bytes, &ctx); 947 tp->iss = digest.words[0] + iss; 948 tp->ts_modulate = digest.words[1]; 949 } 950 951 #ifdef TCP_SIGNATURE 952 int 953 tcp_signature_tdb_attach(void) 954 { 955 return (0); 956 } 957 958 int 959 tcp_signature_tdb_init(struct tdb *tdbp, const struct xformsw *xsp, 960 struct ipsecinit *ii) 961 { 962 if ((ii->ii_authkeylen < 1) || (ii->ii_authkeylen > 80)) 963 return (EINVAL); 964 965 tdbp->tdb_amxkey = malloc(ii->ii_authkeylen, M_XDATA, M_NOWAIT); 966 if (tdbp->tdb_amxkey == NULL) 967 return (ENOMEM); 968 memcpy(tdbp->tdb_amxkey, ii->ii_authkey, ii->ii_authkeylen); 969 tdbp->tdb_amxkeylen = ii->ii_authkeylen; 970 971 return (0); 972 } 973 974 int 975 tcp_signature_tdb_zeroize(struct tdb *tdbp) 976 { 977 if (tdbp->tdb_amxkey) { 978 explicit_bzero(tdbp->tdb_amxkey, tdbp->tdb_amxkeylen); 979 free(tdbp->tdb_amxkey, M_XDATA, tdbp->tdb_amxkeylen); 980 tdbp->tdb_amxkey = NULL; 981 } 982 983 return (0); 984 } 985 986 int 987 tcp_signature_tdb_input(struct mbuf **mp, struct tdb *tdbp, int skip, 988 int protoff) 989 { 990 m_freemp(mp); 991 return (IPPROTO_DONE); 992 } 993 994 int 995 tcp_signature_tdb_output(struct mbuf *m, struct tdb *tdbp, int skip, 996 int protoff) 997 { 998 m_freem(m); 999 return (EINVAL); 1000 } 1001 1002 int 1003 tcp_signature_apply(caddr_t fstate, caddr_t data, unsigned int len) 1004 { 1005 MD5Update((MD5_CTX *)fstate, (char *)data, len); 1006 return 0; 1007 } 1008 1009 int 1010 tcp_signature(struct tdb *tdb, int af, struct mbuf *m, struct tcphdr *th, 1011 int iphlen, int doswap, char *sig) 1012 { 1013 MD5_CTX ctx; 1014 int len; 1015 struct tcphdr th0; 1016 1017 MD5Init(&ctx); 1018 1019 switch(af) { 1020 case 0: 1021 case AF_INET: { 1022 struct ippseudo ippseudo; 1023 struct ip *ip; 1024 1025 ip = mtod(m, struct ip *); 1026 1027 ippseudo.ippseudo_src = ip->ip_src; 1028 ippseudo.ippseudo_dst = ip->ip_dst; 1029 ippseudo.ippseudo_pad = 0; 1030 ippseudo.ippseudo_p = IPPROTO_TCP; 1031 ippseudo.ippseudo_len = htons(m->m_pkthdr.len - iphlen); 1032 1033 MD5Update(&ctx, (char *)&ippseudo, 1034 sizeof(struct ippseudo)); 1035 break; 1036 } 1037 #ifdef INET6 1038 case AF_INET6: { 1039 struct ip6_hdr_pseudo ip6pseudo; 1040 struct ip6_hdr *ip6; 1041 1042 ip6 = mtod(m, struct ip6_hdr *); 1043 bzero(&ip6pseudo, sizeof(ip6pseudo)); 1044 ip6pseudo.ip6ph_src = ip6->ip6_src; 1045 ip6pseudo.ip6ph_dst = ip6->ip6_dst; 1046 in6_clearscope(&ip6pseudo.ip6ph_src); 1047 in6_clearscope(&ip6pseudo.ip6ph_dst); 1048 ip6pseudo.ip6ph_nxt = IPPROTO_TCP; 1049 ip6pseudo.ip6ph_len = htonl(m->m_pkthdr.len - iphlen); 1050 1051 MD5Update(&ctx, (char *)&ip6pseudo, 1052 sizeof(ip6pseudo)); 1053 break; 1054 } 1055 #endif 1056 } 1057 1058 th0 = *th; 1059 th0.th_sum = 0; 1060 1061 if (doswap) { 1062 th0.th_seq = htonl(th0.th_seq); 1063 th0.th_ack = htonl(th0.th_ack); 1064 th0.th_win = htons(th0.th_win); 1065 th0.th_urp = htons(th0.th_urp); 1066 } 1067 MD5Update(&ctx, (char *)&th0, sizeof(th0)); 1068 1069 len = m->m_pkthdr.len - iphlen - th->th_off * sizeof(uint32_t); 1070 1071 if (len > 0 && 1072 m_apply(m, iphlen + th->th_off * sizeof(uint32_t), len, 1073 tcp_signature_apply, (caddr_t)&ctx)) 1074 return (-1); 1075 1076 MD5Update(&ctx, tdb->tdb_amxkey, tdb->tdb_amxkeylen); 1077 MD5Final(sig, &ctx); 1078 1079 return (0); 1080 } 1081 #endif /* TCP_SIGNATURE */ 1082