1 /* $FreeBSD$ */ 2 /* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 3 4 /*- 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * 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 project 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 PROJECT 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 PROJECT 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 33 /*- 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 4. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include "opt_inet.h" 65 #include "opt_inet6.h" 66 #include "opt_ipsec.h" 67 68 #include <sys/param.h> 69 #include <sys/systm.h> 70 #include <sys/malloc.h> 71 #include <sys/mbuf.h> 72 #include <sys/proc.h> 73 #include <sys/domain.h> 74 #include <sys/protosw.h> 75 #include <sys/socket.h> 76 #include <sys/socketvar.h> 77 #include <sys/errno.h> 78 #include <sys/time.h> 79 #include <sys/kernel.h> 80 #include <sys/syslog.h> 81 82 #include <net/if.h> 83 #include <net/if_types.h> 84 #include <net/if_dl.h> 85 #include <net/route.h> 86 #include <net/netisr.h> 87 #include <net/pfil.h> 88 89 #include <netinet/in.h> 90 #include <netinet/in_systm.h> 91 #ifdef INET 92 #include <netinet/ip.h> 93 #include <netinet/ip_icmp.h> 94 #endif /* INET */ 95 #include <netinet/ip6.h> 96 #include <netinet6/in6_var.h> 97 #include <netinet6/ip6_var.h> 98 #include <netinet/in_pcb.h> 99 #include <netinet/icmp6.h> 100 #include <netinet6/scope6_var.h> 101 #include <netinet6/in6_ifattach.h> 102 #include <netinet6/nd6.h> 103 104 #ifdef IPSEC 105 #include <netinet6/ipsec.h> 106 #ifdef INET6 107 #include <netinet6/ipsec6.h> 108 #endif 109 #endif 110 111 #ifdef FAST_IPSEC 112 #include <netipsec/ipsec.h> 113 #include <netipsec/ipsec6.h> 114 #define IPSEC 115 #endif /* FAST_IPSEC */ 116 117 #include <netinet6/ip6protosw.h> 118 119 extern struct domain inet6domain; 120 121 u_char ip6_protox[IPPROTO_MAX]; 122 static struct ifqueue ip6intrq; 123 static int ip6qmaxlen = IFQ_MAXLEN; 124 struct in6_ifaddr *in6_ifaddr; 125 126 extern struct callout in6_tmpaddrtimer_ch; 127 128 int ip6_forward_srcrt; /* XXX */ 129 int ip6_sourcecheck; /* XXX */ 130 int ip6_sourcecheck_interval; /* XXX */ 131 132 int ip6_ours_check_algorithm; 133 134 struct pfil_head inet6_pfil_hook; 135 136 struct ip6stat ip6stat; 137 138 static void ip6_init2 __P((void *)); 139 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 140 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 141 #ifdef PULLDOWN_TEST 142 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 143 #endif 144 145 /* 146 * IP6 initialization: fill in IP6 protocol switch table. 147 * All protocols not implemented in kernel go to raw IP6 protocol handler. 148 */ 149 void 150 ip6_init() 151 { 152 struct ip6protosw *pr; 153 int i; 154 155 #ifdef DIAGNOSTIC 156 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 157 panic("sizeof(protosw) != sizeof(ip6protosw)"); 158 #endif 159 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 160 if (pr == 0) 161 panic("ip6_init"); 162 163 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 164 for (i = 0; i < IPPROTO_MAX; i++) 165 ip6_protox[i] = pr - inet6sw; 166 /* 167 * Cycle through IP protocols and put them into the appropriate place 168 * in ip6_protox[]. 169 */ 170 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 171 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 172 if (pr->pr_domain->dom_family == PF_INET6 && 173 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 174 /* Be careful to only index valid IP protocols. */ 175 if (pr->pr_protocol < IPPROTO_MAX) 176 ip6_protox[pr->pr_protocol] = pr - inet6sw; 177 } 178 179 /* Initialize packet filter hooks. */ 180 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 181 inet6_pfil_hook.ph_af = AF_INET6; 182 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 183 printf("%s: WARNING: unable to register pfil hook, " 184 "error %d\n", __func__, i); 185 186 ip6intrq.ifq_maxlen = ip6qmaxlen; 187 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 188 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 189 scope6_init(); 190 addrsel_policy_init(); 191 nd6_init(); 192 frag6_init(); 193 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 194 } 195 196 static void 197 ip6_init2(dummy) 198 void *dummy; 199 { 200 201 /* nd6_timer_init */ 202 callout_init(&nd6_timer_ch, 0); 203 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 204 205 /* timer for regeneranation of temporary addresses randomize ID */ 206 callout_init(&in6_tmpaddrtimer_ch, 0); 207 callout_reset(&in6_tmpaddrtimer_ch, 208 (ip6_temp_preferred_lifetime - ip6_desync_factor - 209 ip6_temp_regen_advance) * hz, 210 in6_tmpaddrtimer, NULL); 211 } 212 213 /* cheat */ 214 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 215 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 216 217 extern struct route_in6 ip6_forward_rt; 218 219 void 220 ip6_input(m) 221 struct mbuf *m; 222 { 223 struct ip6_hdr *ip6; 224 int off = sizeof(struct ip6_hdr), nest; 225 u_int32_t plen; 226 u_int32_t rtalert = ~0; 227 int nxt, ours = 0; 228 struct ifnet *deliverifp = NULL; 229 struct in6_addr odst; 230 int srcrt = 0; 231 232 GIANT_REQUIRED; /* XXX for now */ 233 #ifdef IPSEC 234 /* 235 * should the inner packet be considered authentic? 236 * see comment in ah4_input(). 237 */ 238 if (m) { 239 m->m_flags &= ~M_AUTHIPHDR; 240 m->m_flags &= ~M_AUTHIPDGM; 241 } 242 #endif 243 244 /* 245 * make sure we don't have onion peering information into m_tag. 246 */ 247 ip6_delaux(m); 248 249 /* 250 * mbuf statistics 251 */ 252 if (m->m_flags & M_EXT) { 253 if (m->m_next) 254 ip6stat.ip6s_mext2m++; 255 else 256 ip6stat.ip6s_mext1++; 257 } else { 258 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 259 if (m->m_next) { 260 if (m->m_flags & M_LOOP) { 261 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 262 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 263 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 264 else 265 ip6stat.ip6s_m2m[0]++; 266 } else 267 ip6stat.ip6s_m1++; 268 #undef M2MMAX 269 } 270 271 /* drop the packet if IPv6 operation is disabled on the IF */ 272 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 273 m_freem(m); 274 return; 275 } 276 277 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 278 ip6stat.ip6s_total++; 279 280 #ifndef PULLDOWN_TEST 281 /* 282 * L2 bridge code and some other code can return mbuf chain 283 * that does not conform to KAME requirement. too bad. 284 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 285 */ 286 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 287 struct mbuf *n; 288 289 MGETHDR(n, M_DONTWAIT, MT_HEADER); 290 if (n) 291 M_MOVE_PKTHDR(n, m); 292 if (n && n->m_pkthdr.len > MHLEN) { 293 MCLGET(n, M_DONTWAIT); 294 if ((n->m_flags & M_EXT) == 0) { 295 m_freem(n); 296 n = NULL; 297 } 298 } 299 if (n == NULL) { 300 m_freem(m); 301 return; /* ENOBUFS */ 302 } 303 304 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 305 n->m_len = n->m_pkthdr.len; 306 m_freem(m); 307 m = n; 308 } 309 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 310 #endif 311 312 if (m->m_len < sizeof(struct ip6_hdr)) { 313 struct ifnet *inifp; 314 inifp = m->m_pkthdr.rcvif; 315 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 316 ip6stat.ip6s_toosmall++; 317 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 318 return; 319 } 320 } 321 322 ip6 = mtod(m, struct ip6_hdr *); 323 324 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 325 ip6stat.ip6s_badvers++; 326 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 327 goto bad; 328 } 329 330 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 331 332 /* 333 * Check against address spoofing/corruption. 334 */ 335 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 336 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 337 /* 338 * XXX: "badscope" is not very suitable for a multicast source. 339 */ 340 ip6stat.ip6s_badscope++; 341 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 342 goto bad; 343 } 344 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 345 !(m->m_flags & M_LOOP)) { 346 /* 347 * In this case, the packet should come from the loopback 348 * interface. However, we cannot just check the if_flags, 349 * because ip6_mloopback() passes the "actual" interface 350 * as the outgoing/incoming interface. 351 */ 352 ip6stat.ip6s_badscope++; 353 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 354 goto bad; 355 } 356 357 #ifdef ALTQ 358 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 359 /* packet is dropped by traffic conditioner */ 360 return; 361 } 362 #endif 363 /* 364 * The following check is not documented in specs. A malicious 365 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 366 * and bypass security checks (act as if it was from 127.0.0.1 by using 367 * IPv6 src ::ffff:127.0.0.1). Be cautious. 368 * 369 * This check chokes if we are in an SIIT cloud. As none of BSDs 370 * support IPv4-less kernel compilation, we cannot support SIIT 371 * environment at all. So, it makes more sense for us to reject any 372 * malicious packets for non-SIIT environment, than try to do a 373 * partial support for SIIT environment. 374 */ 375 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 376 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 377 ip6stat.ip6s_badscope++; 378 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 379 goto bad; 380 } 381 #if 0 382 /* 383 * Reject packets with IPv4 compatible addresses (auto tunnel). 384 * 385 * The code forbids auto tunnel relay case in RFC1933 (the check is 386 * stronger than RFC1933). We may want to re-enable it if mech-xx 387 * is revised to forbid relaying case. 388 */ 389 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 390 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 391 ip6stat.ip6s_badscope++; 392 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 393 goto bad; 394 } 395 #endif 396 397 /* 398 * Run through list of hooks for input packets. 399 * 400 * NB: Beware of the destination address changing 401 * (e.g. by NAT rewriting). When this happens, 402 * tell ip6_forward to do the right thing. 403 */ 404 odst = ip6->ip6_dst; 405 406 /* Jump over all PFIL processing if hooks are not active. */ 407 if (!PFIL_HOOKED(&inet6_pfil_hook)) 408 goto passin; 409 410 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 411 return; 412 if (m == NULL) /* consumed by filter */ 413 return; 414 ip6 = mtod(m, struct ip6_hdr *); 415 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 416 417 passin: 418 /* 419 * Disambiguate address scope zones (if there is ambiguity). 420 * We first make sure that the original source or destination address 421 * is not in our internal form for scoped addresses. Such addresses 422 * are not necessarily invalid spec-wise, but we cannot accept them due 423 * to the usage conflict. 424 * in6_setscope() then also checks and rejects the cases where src or 425 * dst are the loopback address and the receiving interface 426 * is not loopback. 427 */ 428 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 429 ip6stat.ip6s_badscope++; /* XXX */ 430 goto bad; 431 } 432 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 433 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 434 ip6stat.ip6s_badscope++; 435 goto bad; 436 } 437 438 /* 439 * Multicast check 440 */ 441 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 442 struct in6_multi *in6m = 0; 443 444 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 445 /* 446 * See if we belong to the destination multicast group on the 447 * arrival interface. 448 */ 449 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 450 if (in6m) 451 ours = 1; 452 else if (!ip6_mrouter) { 453 ip6stat.ip6s_notmember++; 454 ip6stat.ip6s_cantforward++; 455 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 456 goto bad; 457 } 458 deliverifp = m->m_pkthdr.rcvif; 459 goto hbhcheck; 460 } 461 462 /* 463 * Unicast check 464 */ 465 if (ip6_forward_rt.ro_rt != NULL && 466 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 467 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 468 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 469 ip6stat.ip6s_forward_cachehit++; 470 else { 471 struct sockaddr_in6 *dst6; 472 473 if (ip6_forward_rt.ro_rt) { 474 /* route is down or destination is different */ 475 ip6stat.ip6s_forward_cachemiss++; 476 RTFREE(ip6_forward_rt.ro_rt); 477 ip6_forward_rt.ro_rt = 0; 478 } 479 480 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 481 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 482 dst6->sin6_len = sizeof(struct sockaddr_in6); 483 dst6->sin6_family = AF_INET6; 484 dst6->sin6_addr = ip6->ip6_dst; 485 486 rtalloc((struct route *)&ip6_forward_rt); 487 } 488 489 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 490 491 /* 492 * Accept the packet if the forwarding interface to the destination 493 * according to the routing table is the loopback interface, 494 * unless the associated route has a gateway. 495 * Note that this approach causes to accept a packet if there is a 496 * route to the loopback interface for the destination of the packet. 497 * But we think it's even useful in some situations, e.g. when using 498 * a special daemon which wants to intercept the packet. 499 * 500 * XXX: some OSes automatically make a cloned route for the destination 501 * of an outgoing packet. If the outgoing interface of the packet 502 * is a loopback one, the kernel would consider the packet to be 503 * accepted, even if we have no such address assinged on the interface. 504 * We check the cloned flag of the route entry to reject such cases, 505 * assuming that route entries for our own addresses are not made by 506 * cloning (it should be true because in6_addloop explicitly installs 507 * the host route). However, we might have to do an explicit check 508 * while it would be less efficient. Or, should we rather install a 509 * reject route for such a case? 510 */ 511 if (ip6_forward_rt.ro_rt && 512 (ip6_forward_rt.ro_rt->rt_flags & 513 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 514 #ifdef RTF_WASCLONED 515 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 516 #endif 517 #ifdef RTF_CLONED 518 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 519 #endif 520 #if 0 521 /* 522 * The check below is redundant since the comparison of 523 * the destination and the key of the rtentry has 524 * already done through looking up the routing table. 525 */ 526 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 527 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 528 #endif 529 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 530 struct in6_ifaddr *ia6 = 531 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 532 533 /* 534 * record address information into m_tag. 535 */ 536 (void)ip6_setdstifaddr(m, ia6); 537 538 /* 539 * packets to a tentative, duplicated, or somehow invalid 540 * address must not be accepted. 541 */ 542 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 543 /* this address is ready */ 544 ours = 1; 545 deliverifp = ia6->ia_ifp; /* correct? */ 546 /* Count the packet in the ip address stats */ 547 ia6->ia_ifa.if_ipackets++; 548 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 549 goto hbhcheck; 550 } else { 551 char ip6bufs[INET6_ADDRSTRLEN]; 552 char ip6bufd[INET6_ADDRSTRLEN]; 553 /* address is not ready, so discard the packet. */ 554 nd6log((LOG_INFO, 555 "ip6_input: packet to an unready address %s->%s\n", 556 ip6_sprintf(ip6bufs, &ip6->ip6_src), 557 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 558 559 goto bad; 560 } 561 } 562 563 /* 564 * FAITH (Firewall Aided Internet Translator) 565 */ 566 if (ip6_keepfaith) { 567 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 568 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 569 /* XXX do we need more sanity checks? */ 570 ours = 1; 571 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 572 goto hbhcheck; 573 } 574 } 575 576 /* 577 * Now there is no reason to process the packet if it's not our own 578 * and we're not a router. 579 */ 580 if (!ip6_forwarding) { 581 ip6stat.ip6s_cantforward++; 582 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 583 goto bad; 584 } 585 586 hbhcheck: 587 /* 588 * record address information into m_tag, if we don't have one yet. 589 * note that we are unable to record it, if the address is not listed 590 * as our interface address (e.g. multicast addresses, addresses 591 * within FAITH prefixes and such). 592 */ 593 if (deliverifp && !ip6_getdstifaddr(m)) { 594 struct in6_ifaddr *ia6; 595 596 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 597 if (ia6) { 598 if (!ip6_setdstifaddr(m, ia6)) { 599 /* 600 * XXX maybe we should drop the packet here, 601 * as we could not provide enough information 602 * to the upper layers. 603 */ 604 } 605 } 606 } 607 608 /* 609 * Process Hop-by-Hop options header if it's contained. 610 * m may be modified in ip6_hopopts_input(). 611 * If a JumboPayload option is included, plen will also be modified. 612 */ 613 plen = (u_int32_t)ntohs(ip6->ip6_plen); 614 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 615 struct ip6_hbh *hbh; 616 617 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 618 #if 0 /*touches NULL pointer*/ 619 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 620 #endif 621 return; /* m have already been freed */ 622 } 623 624 /* adjust pointer */ 625 ip6 = mtod(m, struct ip6_hdr *); 626 627 /* 628 * if the payload length field is 0 and the next header field 629 * indicates Hop-by-Hop Options header, then a Jumbo Payload 630 * option MUST be included. 631 */ 632 if (ip6->ip6_plen == 0 && plen == 0) { 633 /* 634 * Note that if a valid jumbo payload option is 635 * contained, ip6_hopopts_input() must set a valid 636 * (non-zero) payload length to the variable plen. 637 */ 638 ip6stat.ip6s_badoptions++; 639 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 640 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 641 icmp6_error(m, ICMP6_PARAM_PROB, 642 ICMP6_PARAMPROB_HEADER, 643 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 644 return; 645 } 646 #ifndef PULLDOWN_TEST 647 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 648 hbh = (struct ip6_hbh *)(ip6 + 1); 649 #else 650 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 651 sizeof(struct ip6_hbh)); 652 if (hbh == NULL) { 653 ip6stat.ip6s_tooshort++; 654 return; 655 } 656 #endif 657 nxt = hbh->ip6h_nxt; 658 659 /* 660 * accept the packet if a router alert option is included 661 * and we act as an IPv6 router. 662 */ 663 if (rtalert != ~0 && ip6_forwarding) 664 ours = 1; 665 } else 666 nxt = ip6->ip6_nxt; 667 668 /* 669 * Check that the amount of data in the buffers 670 * is as at least much as the IPv6 header would have us expect. 671 * Trim mbufs if longer than we expect. 672 * Drop packet if shorter than we expect. 673 */ 674 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 675 ip6stat.ip6s_tooshort++; 676 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 677 goto bad; 678 } 679 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 680 if (m->m_len == m->m_pkthdr.len) { 681 m->m_len = sizeof(struct ip6_hdr) + plen; 682 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 683 } else 684 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 685 } 686 687 /* 688 * Forward if desirable. 689 */ 690 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 691 /* 692 * If we are acting as a multicast router, all 693 * incoming multicast packets are passed to the 694 * kernel-level multicast forwarding function. 695 * The packet is returned (relatively) intact; if 696 * ip6_mforward() returns a non-zero value, the packet 697 * must be discarded, else it may be accepted below. 698 */ 699 if (ip6_mrouter && ip6_mforward && 700 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 701 ip6stat.ip6s_cantforward++; 702 m_freem(m); 703 return; 704 } 705 if (!ours) { 706 m_freem(m); 707 return; 708 } 709 } else if (!ours) { 710 ip6_forward(m, srcrt); 711 return; 712 } 713 714 ip6 = mtod(m, struct ip6_hdr *); 715 716 /* 717 * Malicious party may be able to use IPv4 mapped addr to confuse 718 * tcp/udp stack and bypass security checks (act as if it was from 719 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 720 * 721 * For SIIT end node behavior, you may want to disable the check. 722 * However, you will become vulnerable to attacks using IPv4 mapped 723 * source. 724 */ 725 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 726 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 727 ip6stat.ip6s_badscope++; 728 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 729 goto bad; 730 } 731 732 /* 733 * Tell launch routine the next header 734 */ 735 ip6stat.ip6s_delivered++; 736 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 737 nest = 0; 738 739 while (nxt != IPPROTO_DONE) { 740 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 741 ip6stat.ip6s_toomanyhdr++; 742 goto bad; 743 } 744 745 /* 746 * protection against faulty packet - there should be 747 * more sanity checks in header chain processing. 748 */ 749 if (m->m_pkthdr.len < off) { 750 ip6stat.ip6s_tooshort++; 751 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 752 goto bad; 753 } 754 755 #ifdef IPSEC 756 /* 757 * enforce IPsec policy checking if we are seeing last header. 758 * note that we do not visit this with protocols with pcb layer 759 * code - like udp/tcp/raw ip. 760 */ 761 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 762 ipsec6_in_reject(m, NULL)) { 763 ipsec6stat.in_polvio++; 764 goto bad; 765 } 766 #endif 767 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 768 } 769 return; 770 bad: 771 m_freem(m); 772 } 773 774 /* 775 * set/grab in6_ifaddr correspond to IPv6 destination address. 776 * XXX backward compatibility wrapper 777 */ 778 static struct ip6aux * 779 ip6_setdstifaddr(m, ia6) 780 struct mbuf *m; 781 struct in6_ifaddr *ia6; 782 { 783 struct ip6aux *ip6a; 784 785 ip6a = ip6_addaux(m); 786 if (ip6a) 787 ip6a->ip6a_dstia6 = ia6; 788 return ip6a; /* NULL if failed to set */ 789 } 790 791 struct in6_ifaddr * 792 ip6_getdstifaddr(m) 793 struct mbuf *m; 794 { 795 struct ip6aux *ip6a; 796 797 ip6a = ip6_findaux(m); 798 if (ip6a) 799 return ip6a->ip6a_dstia6; 800 else 801 return NULL; 802 } 803 804 /* 805 * Hop-by-Hop options header processing. If a valid jumbo payload option is 806 * included, the real payload length will be stored in plenp. 807 */ 808 static int 809 ip6_hopopts_input(plenp, rtalertp, mp, offp) 810 u_int32_t *plenp; 811 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 812 struct mbuf **mp; 813 int *offp; 814 { 815 struct mbuf *m = *mp; 816 int off = *offp, hbhlen; 817 struct ip6_hbh *hbh; 818 u_int8_t *opt; 819 820 /* validation of the length of the header */ 821 #ifndef PULLDOWN_TEST 822 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 823 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 824 hbhlen = (hbh->ip6h_len + 1) << 3; 825 826 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 827 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 828 #else 829 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 830 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 831 if (hbh == NULL) { 832 ip6stat.ip6s_tooshort++; 833 return -1; 834 } 835 hbhlen = (hbh->ip6h_len + 1) << 3; 836 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 837 hbhlen); 838 if (hbh == NULL) { 839 ip6stat.ip6s_tooshort++; 840 return -1; 841 } 842 #endif 843 off += hbhlen; 844 hbhlen -= sizeof(struct ip6_hbh); 845 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 846 847 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 848 hbhlen, rtalertp, plenp) < 0) 849 return (-1); 850 851 *offp = off; 852 *mp = m; 853 return (0); 854 } 855 856 /* 857 * Search header for all Hop-by-hop options and process each option. 858 * This function is separate from ip6_hopopts_input() in order to 859 * handle a case where the sending node itself process its hop-by-hop 860 * options header. In such a case, the function is called from ip6_output(). 861 * 862 * The function assumes that hbh header is located right after the IPv6 header 863 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 864 * opthead + hbhlen is located in continuous memory region. 865 */ 866 int 867 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 868 struct mbuf *m; 869 u_int8_t *opthead; 870 int hbhlen; 871 u_int32_t *rtalertp; 872 u_int32_t *plenp; 873 { 874 struct ip6_hdr *ip6; 875 int optlen = 0; 876 u_int8_t *opt = opthead; 877 u_int16_t rtalert_val; 878 u_int32_t jumboplen; 879 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 880 881 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 882 switch (*opt) { 883 case IP6OPT_PAD1: 884 optlen = 1; 885 break; 886 case IP6OPT_PADN: 887 if (hbhlen < IP6OPT_MINLEN) { 888 ip6stat.ip6s_toosmall++; 889 goto bad; 890 } 891 optlen = *(opt + 1) + 2; 892 break; 893 case IP6OPT_ROUTER_ALERT: 894 /* XXX may need check for alignment */ 895 if (hbhlen < IP6OPT_RTALERT_LEN) { 896 ip6stat.ip6s_toosmall++; 897 goto bad; 898 } 899 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 900 /* XXX stat */ 901 icmp6_error(m, ICMP6_PARAM_PROB, 902 ICMP6_PARAMPROB_HEADER, 903 erroff + opt + 1 - opthead); 904 return (-1); 905 } 906 optlen = IP6OPT_RTALERT_LEN; 907 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 908 *rtalertp = ntohs(rtalert_val); 909 break; 910 case IP6OPT_JUMBO: 911 /* XXX may need check for alignment */ 912 if (hbhlen < IP6OPT_JUMBO_LEN) { 913 ip6stat.ip6s_toosmall++; 914 goto bad; 915 } 916 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 917 /* XXX stat */ 918 icmp6_error(m, ICMP6_PARAM_PROB, 919 ICMP6_PARAMPROB_HEADER, 920 erroff + opt + 1 - opthead); 921 return (-1); 922 } 923 optlen = IP6OPT_JUMBO_LEN; 924 925 /* 926 * IPv6 packets that have non 0 payload length 927 * must not contain a jumbo payload option. 928 */ 929 ip6 = mtod(m, struct ip6_hdr *); 930 if (ip6->ip6_plen) { 931 ip6stat.ip6s_badoptions++; 932 icmp6_error(m, ICMP6_PARAM_PROB, 933 ICMP6_PARAMPROB_HEADER, 934 erroff + opt - opthead); 935 return (-1); 936 } 937 938 /* 939 * We may see jumbolen in unaligned location, so 940 * we'd need to perform bcopy(). 941 */ 942 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 943 jumboplen = (u_int32_t)htonl(jumboplen); 944 945 #if 1 946 /* 947 * if there are multiple jumbo payload options, 948 * *plenp will be non-zero and the packet will be 949 * rejected. 950 * the behavior may need some debate in ipngwg - 951 * multiple options does not make sense, however, 952 * there's no explicit mention in specification. 953 */ 954 if (*plenp != 0) { 955 ip6stat.ip6s_badoptions++; 956 icmp6_error(m, ICMP6_PARAM_PROB, 957 ICMP6_PARAMPROB_HEADER, 958 erroff + opt + 2 - opthead); 959 return (-1); 960 } 961 #endif 962 963 /* 964 * jumbo payload length must be larger than 65535. 965 */ 966 if (jumboplen <= IPV6_MAXPACKET) { 967 ip6stat.ip6s_badoptions++; 968 icmp6_error(m, ICMP6_PARAM_PROB, 969 ICMP6_PARAMPROB_HEADER, 970 erroff + opt + 2 - opthead); 971 return (-1); 972 } 973 *plenp = jumboplen; 974 975 break; 976 default: /* unknown option */ 977 if (hbhlen < IP6OPT_MINLEN) { 978 ip6stat.ip6s_toosmall++; 979 goto bad; 980 } 981 optlen = ip6_unknown_opt(opt, m, 982 erroff + opt - opthead); 983 if (optlen == -1) 984 return (-1); 985 optlen += 2; 986 break; 987 } 988 } 989 990 return (0); 991 992 bad: 993 m_freem(m); 994 return (-1); 995 } 996 997 /* 998 * Unknown option processing. 999 * The third argument `off' is the offset from the IPv6 header to the option, 1000 * which is necessary if the IPv6 header the and option header and IPv6 header 1001 * is not continuous in order to return an ICMPv6 error. 1002 */ 1003 int 1004 ip6_unknown_opt(optp, m, off) 1005 u_int8_t *optp; 1006 struct mbuf *m; 1007 int off; 1008 { 1009 struct ip6_hdr *ip6; 1010 1011 switch (IP6OPT_TYPE(*optp)) { 1012 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1013 return ((int)*(optp + 1)); 1014 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1015 m_freem(m); 1016 return (-1); 1017 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1018 ip6stat.ip6s_badoptions++; 1019 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1020 return (-1); 1021 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1022 ip6stat.ip6s_badoptions++; 1023 ip6 = mtod(m, struct ip6_hdr *); 1024 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1025 (m->m_flags & (M_BCAST|M_MCAST))) 1026 m_freem(m); 1027 else 1028 icmp6_error(m, ICMP6_PARAM_PROB, 1029 ICMP6_PARAMPROB_OPTION, off); 1030 return (-1); 1031 } 1032 1033 m_freem(m); /* XXX: NOTREACHED */ 1034 return (-1); 1035 } 1036 1037 /* 1038 * Create the "control" list for this pcb. 1039 * The function will not modify mbuf chain at all. 1040 * 1041 * with KAME mbuf chain restriction: 1042 * The routine will be called from upper layer handlers like tcp6_input(). 1043 * Thus the routine assumes that the caller (tcp6_input) have already 1044 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1045 * very first mbuf on the mbuf chain. 1046 */ 1047 void 1048 ip6_savecontrol(in6p, m, mp) 1049 struct inpcb *in6p; 1050 struct mbuf *m, **mp; 1051 { 1052 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1053 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1054 1055 #ifdef SO_TIMESTAMP 1056 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1057 struct timeval tv; 1058 1059 microtime(&tv); 1060 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1061 SCM_TIMESTAMP, SOL_SOCKET); 1062 if (*mp) 1063 mp = &(*mp)->m_next; 1064 } 1065 #endif 1066 1067 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1068 return; 1069 1070 /* RFC 2292 sec. 5 */ 1071 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1072 struct in6_pktinfo pi6; 1073 1074 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1075 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1076 pi6.ipi6_ifindex = 1077 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1078 1079 *mp = sbcreatecontrol((caddr_t) &pi6, 1080 sizeof(struct in6_pktinfo), 1081 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1082 if (*mp) 1083 mp = &(*mp)->m_next; 1084 } 1085 1086 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1087 int hlim = ip6->ip6_hlim & 0xff; 1088 1089 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1090 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1091 if (*mp) 1092 mp = &(*mp)->m_next; 1093 } 1094 1095 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1096 u_int32_t flowinfo; 1097 int tclass; 1098 1099 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1100 flowinfo >>= 20; 1101 1102 tclass = flowinfo & 0xff; 1103 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1104 IPV6_TCLASS, IPPROTO_IPV6); 1105 if (*mp) 1106 mp = &(*mp)->m_next; 1107 } 1108 1109 /* 1110 * IPV6_HOPOPTS socket option. Recall that we required super-user 1111 * privilege for the option (see ip6_ctloutput), but it might be too 1112 * strict, since there might be some hop-by-hop options which can be 1113 * returned to normal user. 1114 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1115 */ 1116 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1117 /* 1118 * Check if a hop-by-hop options header is contatined in the 1119 * received packet, and if so, store the options as ancillary 1120 * data. Note that a hop-by-hop options header must be 1121 * just after the IPv6 header, which is assured through the 1122 * IPv6 input processing. 1123 */ 1124 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1125 struct ip6_hbh *hbh; 1126 int hbhlen = 0; 1127 #ifdef PULLDOWN_TEST 1128 struct mbuf *ext; 1129 #endif 1130 1131 #ifndef PULLDOWN_TEST 1132 hbh = (struct ip6_hbh *)(ip6 + 1); 1133 hbhlen = (hbh->ip6h_len + 1) << 3; 1134 #else 1135 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1136 ip6->ip6_nxt); 1137 if (ext == NULL) { 1138 ip6stat.ip6s_tooshort++; 1139 return; 1140 } 1141 hbh = mtod(ext, struct ip6_hbh *); 1142 hbhlen = (hbh->ip6h_len + 1) << 3; 1143 if (hbhlen != ext->m_len) { 1144 m_freem(ext); 1145 ip6stat.ip6s_tooshort++; 1146 return; 1147 } 1148 #endif 1149 1150 /* 1151 * XXX: We copy the whole header even if a 1152 * jumbo payload option is included, the option which 1153 * is to be removed before returning according to 1154 * RFC2292. 1155 * Note: this constraint is removed in RFC3542 1156 */ 1157 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1158 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1159 IPPROTO_IPV6); 1160 if (*mp) 1161 mp = &(*mp)->m_next; 1162 #ifdef PULLDOWN_TEST 1163 m_freem(ext); 1164 #endif 1165 } 1166 } 1167 1168 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1169 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1170 1171 /* 1172 * Search for destination options headers or routing 1173 * header(s) through the header chain, and stores each 1174 * header as ancillary data. 1175 * Note that the order of the headers remains in 1176 * the chain of ancillary data. 1177 */ 1178 while (1) { /* is explicit loop prevention necessary? */ 1179 struct ip6_ext *ip6e = NULL; 1180 int elen; 1181 #ifdef PULLDOWN_TEST 1182 struct mbuf *ext = NULL; 1183 #endif 1184 1185 /* 1186 * if it is not an extension header, don't try to 1187 * pull it from the chain. 1188 */ 1189 switch (nxt) { 1190 case IPPROTO_DSTOPTS: 1191 case IPPROTO_ROUTING: 1192 case IPPROTO_HOPOPTS: 1193 case IPPROTO_AH: /* is it possible? */ 1194 break; 1195 default: 1196 goto loopend; 1197 } 1198 1199 #ifndef PULLDOWN_TEST 1200 if (off + sizeof(*ip6e) > m->m_len) 1201 goto loopend; 1202 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1203 if (nxt == IPPROTO_AH) 1204 elen = (ip6e->ip6e_len + 2) << 2; 1205 else 1206 elen = (ip6e->ip6e_len + 1) << 3; 1207 if (off + elen > m->m_len) 1208 goto loopend; 1209 #else 1210 ext = ip6_pullexthdr(m, off, nxt); 1211 if (ext == NULL) { 1212 ip6stat.ip6s_tooshort++; 1213 return; 1214 } 1215 ip6e = mtod(ext, struct ip6_ext *); 1216 if (nxt == IPPROTO_AH) 1217 elen = (ip6e->ip6e_len + 2) << 2; 1218 else 1219 elen = (ip6e->ip6e_len + 1) << 3; 1220 if (elen != ext->m_len) { 1221 m_freem(ext); 1222 ip6stat.ip6s_tooshort++; 1223 return; 1224 } 1225 #endif 1226 1227 switch (nxt) { 1228 case IPPROTO_DSTOPTS: 1229 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1230 break; 1231 1232 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1233 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1234 IPPROTO_IPV6); 1235 if (*mp) 1236 mp = &(*mp)->m_next; 1237 break; 1238 case IPPROTO_ROUTING: 1239 if (!in6p->in6p_flags & IN6P_RTHDR) 1240 break; 1241 1242 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1243 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1244 IPPROTO_IPV6); 1245 if (*mp) 1246 mp = &(*mp)->m_next; 1247 break; 1248 case IPPROTO_HOPOPTS: 1249 case IPPROTO_AH: /* is it possible? */ 1250 break; 1251 1252 default: 1253 /* 1254 * other cases have been filtered in the above. 1255 * none will visit this case. here we supply 1256 * the code just in case (nxt overwritten or 1257 * other cases). 1258 */ 1259 #ifdef PULLDOWN_TEST 1260 m_freem(ext); 1261 #endif 1262 goto loopend; 1263 1264 } 1265 1266 /* proceed with the next header. */ 1267 off += elen; 1268 nxt = ip6e->ip6e_nxt; 1269 ip6e = NULL; 1270 #ifdef PULLDOWN_TEST 1271 m_freem(ext); 1272 ext = NULL; 1273 #endif 1274 } 1275 loopend: 1276 ; 1277 } 1278 1279 #undef IS2292 1280 } 1281 1282 void 1283 ip6_notify_pmtu(in6p, dst, mtu) 1284 struct inpcb *in6p; 1285 struct sockaddr_in6 *dst; 1286 u_int32_t *mtu; 1287 { 1288 struct socket *so; 1289 struct mbuf *m_mtu; 1290 struct ip6_mtuinfo mtuctl; 1291 1292 so = in6p->inp_socket; 1293 1294 if (mtu == NULL) 1295 return; 1296 1297 #ifdef DIAGNOSTIC 1298 if (so == NULL) /* I believe this is impossible */ 1299 panic("ip6_notify_pmtu: socket is NULL"); 1300 #endif 1301 1302 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1303 mtuctl.ip6m_mtu = *mtu; 1304 mtuctl.ip6m_addr = *dst; 1305 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1306 return; 1307 1308 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1309 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1310 return; 1311 1312 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1313 == 0) { 1314 m_freem(m_mtu); 1315 /* XXX: should count statistics */ 1316 } else 1317 sorwakeup(so); 1318 1319 return; 1320 } 1321 1322 #ifdef PULLDOWN_TEST 1323 /* 1324 * pull single extension header from mbuf chain. returns single mbuf that 1325 * contains the result, or NULL on error. 1326 */ 1327 static struct mbuf * 1328 ip6_pullexthdr(m, off, nxt) 1329 struct mbuf *m; 1330 size_t off; 1331 int nxt; 1332 { 1333 struct ip6_ext ip6e; 1334 size_t elen; 1335 struct mbuf *n; 1336 1337 #ifdef DIAGNOSTIC 1338 switch (nxt) { 1339 case IPPROTO_DSTOPTS: 1340 case IPPROTO_ROUTING: 1341 case IPPROTO_HOPOPTS: 1342 case IPPROTO_AH: /* is it possible? */ 1343 break; 1344 default: 1345 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1346 } 1347 #endif 1348 1349 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1350 if (nxt == IPPROTO_AH) 1351 elen = (ip6e.ip6e_len + 2) << 2; 1352 else 1353 elen = (ip6e.ip6e_len + 1) << 3; 1354 1355 MGET(n, M_DONTWAIT, MT_DATA); 1356 if (n && elen >= MLEN) { 1357 MCLGET(n, M_DONTWAIT); 1358 if ((n->m_flags & M_EXT) == 0) { 1359 m_free(n); 1360 n = NULL; 1361 } 1362 } 1363 if (!n) 1364 return NULL; 1365 1366 n->m_len = 0; 1367 if (elen >= M_TRAILINGSPACE(n)) { 1368 m_free(n); 1369 return NULL; 1370 } 1371 1372 m_copydata(m, off, elen, mtod(n, caddr_t)); 1373 n->m_len = elen; 1374 return n; 1375 } 1376 #endif 1377 1378 /* 1379 * Get pointer to the previous header followed by the header 1380 * currently processed. 1381 * XXX: This function supposes that 1382 * M includes all headers, 1383 * the next header field and the header length field of each header 1384 * are valid, and 1385 * the sum of each header length equals to OFF. 1386 * Because of these assumptions, this function must be called very 1387 * carefully. Moreover, it will not be used in the near future when 1388 * we develop `neater' mechanism to process extension headers. 1389 */ 1390 char * 1391 ip6_get_prevhdr(m, off) 1392 struct mbuf *m; 1393 int off; 1394 { 1395 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1396 1397 if (off == sizeof(struct ip6_hdr)) 1398 return (&ip6->ip6_nxt); 1399 else { 1400 int len, nxt; 1401 struct ip6_ext *ip6e = NULL; 1402 1403 nxt = ip6->ip6_nxt; 1404 len = sizeof(struct ip6_hdr); 1405 while (len < off) { 1406 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1407 1408 switch (nxt) { 1409 case IPPROTO_FRAGMENT: 1410 len += sizeof(struct ip6_frag); 1411 break; 1412 case IPPROTO_AH: 1413 len += (ip6e->ip6e_len + 2) << 2; 1414 break; 1415 default: 1416 len += (ip6e->ip6e_len + 1) << 3; 1417 break; 1418 } 1419 nxt = ip6e->ip6e_nxt; 1420 } 1421 if (ip6e) 1422 return (&ip6e->ip6e_nxt); 1423 else 1424 return NULL; 1425 } 1426 } 1427 1428 /* 1429 * get next header offset. m will be retained. 1430 */ 1431 int 1432 ip6_nexthdr(m, off, proto, nxtp) 1433 struct mbuf *m; 1434 int off; 1435 int proto; 1436 int *nxtp; 1437 { 1438 struct ip6_hdr ip6; 1439 struct ip6_ext ip6e; 1440 struct ip6_frag fh; 1441 1442 /* just in case */ 1443 if (m == NULL) 1444 panic("ip6_nexthdr: m == NULL"); 1445 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1446 return -1; 1447 1448 switch (proto) { 1449 case IPPROTO_IPV6: 1450 if (m->m_pkthdr.len < off + sizeof(ip6)) 1451 return -1; 1452 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1453 if (nxtp) 1454 *nxtp = ip6.ip6_nxt; 1455 off += sizeof(ip6); 1456 return off; 1457 1458 case IPPROTO_FRAGMENT: 1459 /* 1460 * terminate parsing if it is not the first fragment, 1461 * it does not make sense to parse through it. 1462 */ 1463 if (m->m_pkthdr.len < off + sizeof(fh)) 1464 return -1; 1465 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1466 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1467 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1468 return -1; 1469 if (nxtp) 1470 *nxtp = fh.ip6f_nxt; 1471 off += sizeof(struct ip6_frag); 1472 return off; 1473 1474 case IPPROTO_AH: 1475 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1476 return -1; 1477 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1478 if (nxtp) 1479 *nxtp = ip6e.ip6e_nxt; 1480 off += (ip6e.ip6e_len + 2) << 2; 1481 return off; 1482 1483 case IPPROTO_HOPOPTS: 1484 case IPPROTO_ROUTING: 1485 case IPPROTO_DSTOPTS: 1486 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1487 return -1; 1488 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1489 if (nxtp) 1490 *nxtp = ip6e.ip6e_nxt; 1491 off += (ip6e.ip6e_len + 1) << 3; 1492 return off; 1493 1494 case IPPROTO_NONE: 1495 case IPPROTO_ESP: 1496 case IPPROTO_IPCOMP: 1497 /* give up */ 1498 return -1; 1499 1500 default: 1501 return -1; 1502 } 1503 1504 return -1; 1505 } 1506 1507 /* 1508 * get offset for the last header in the chain. m will be kept untainted. 1509 */ 1510 int 1511 ip6_lasthdr(m, off, proto, nxtp) 1512 struct mbuf *m; 1513 int off; 1514 int proto; 1515 int *nxtp; 1516 { 1517 int newoff; 1518 int nxt; 1519 1520 if (!nxtp) { 1521 nxt = -1; 1522 nxtp = &nxt; 1523 } 1524 while (1) { 1525 newoff = ip6_nexthdr(m, off, proto, nxtp); 1526 if (newoff < 0) 1527 return off; 1528 else if (newoff < off) 1529 return -1; /* invalid */ 1530 else if (newoff == off) 1531 return newoff; 1532 1533 off = newoff; 1534 proto = *nxtp; 1535 } 1536 } 1537 1538 struct ip6aux * 1539 ip6_addaux(m) 1540 struct mbuf *m; 1541 { 1542 struct m_tag *mtag; 1543 1544 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1545 if (!mtag) { 1546 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1547 M_NOWAIT); 1548 if (mtag) { 1549 m_tag_prepend(m, mtag); 1550 bzero(mtag + 1, sizeof(struct ip6aux)); 1551 } 1552 } 1553 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1554 } 1555 1556 struct ip6aux * 1557 ip6_findaux(m) 1558 struct mbuf *m; 1559 { 1560 struct m_tag *mtag; 1561 1562 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1563 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1564 } 1565 1566 void 1567 ip6_delaux(m) 1568 struct mbuf *m; 1569 { 1570 struct m_tag *mtag; 1571 1572 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1573 if (mtag) 1574 m_tag_delete(m, mtag); 1575 } 1576 1577 /* 1578 * System control for IP6 1579 */ 1580 1581 u_char inet6ctlerrmap[PRC_NCMDS] = { 1582 0, 0, 0, 0, 1583 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1584 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1585 EMSGSIZE, EHOSTUNREACH, 0, 0, 1586 0, 0, 0, 0, 1587 ENOPROTOOPT 1588 }; 1589