1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1988, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 #include "opt_ipsec.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/proc.h> 75 #include <sys/domain.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/errno.h> 80 #include <sys/time.h> 81 #include <sys/kernel.h> 82 #include <sys/syslog.h> 83 84 #include <net/if.h> 85 #include <net/if_types.h> 86 #include <net/if_dl.h> 87 #include <net/route.h> 88 #include <net/netisr.h> 89 #include <net/pfil.h> 90 91 #include <netinet/in.h> 92 #include <netinet/in_systm.h> 93 #ifdef INET 94 #include <netinet/ip.h> 95 #include <netinet/ip_icmp.h> 96 #endif /* INET */ 97 #include <netinet/ip6.h> 98 #include <netinet6/in6_var.h> 99 #include <netinet6/ip6_var.h> 100 #include <netinet/in_pcb.h> 101 #include <netinet/icmp6.h> 102 #include <netinet6/scope6_var.h> 103 #include <netinet6/in6_ifattach.h> 104 #include <netinet6/nd6.h> 105 106 #ifdef IPSEC 107 #include <netipsec/ipsec.h> 108 #include <netinet6/ip6_ipsec.h> 109 #include <netipsec/ipsec6.h> 110 #endif /* IPSEC */ 111 112 #include <netinet6/ip6protosw.h> 113 114 extern struct domain inet6domain; 115 116 u_char ip6_protox[IPPROTO_MAX]; 117 static struct ifqueue ip6intrq; 118 static int ip6qmaxlen = IFQ_MAXLEN; 119 struct in6_ifaddr *in6_ifaddr; 120 121 extern struct callout in6_tmpaddrtimer_ch; 122 123 int ip6_forward_srcrt; /* XXX */ 124 int ip6_sourcecheck; /* XXX */ 125 int ip6_sourcecheck_interval; /* XXX */ 126 127 int ip6_ours_check_algorithm; 128 129 struct pfil_head inet6_pfil_hook; 130 131 struct ip6stat ip6stat; 132 133 static void ip6_init2(void *); 134 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 135 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 136 #ifdef PULLDOWN_TEST 137 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 138 #endif 139 140 /* 141 * IP6 initialization: fill in IP6 protocol switch table. 142 * All protocols not implemented in kernel go to raw IP6 protocol handler. 143 */ 144 void 145 ip6_init(void) 146 { 147 struct ip6protosw *pr; 148 int i; 149 150 #ifdef DIAGNOSTIC 151 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 152 panic("sizeof(protosw) != sizeof(ip6protosw)"); 153 #endif 154 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 155 if (pr == 0) 156 panic("ip6_init"); 157 158 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 159 for (i = 0; i < IPPROTO_MAX; i++) 160 ip6_protox[i] = pr - inet6sw; 161 /* 162 * Cycle through IP protocols and put them into the appropriate place 163 * in ip6_protox[]. 164 */ 165 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 166 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 167 if (pr->pr_domain->dom_family == PF_INET6 && 168 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 169 /* Be careful to only index valid IP protocols. */ 170 if (pr->pr_protocol < IPPROTO_MAX) 171 ip6_protox[pr->pr_protocol] = pr - inet6sw; 172 } 173 174 /* Initialize packet filter hooks. */ 175 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 176 inet6_pfil_hook.ph_af = AF_INET6; 177 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 178 printf("%s: WARNING: unable to register pfil hook, " 179 "error %d\n", __func__, i); 180 181 ip6intrq.ifq_maxlen = ip6qmaxlen; 182 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 183 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 184 scope6_init(); 185 addrsel_policy_init(); 186 nd6_init(); 187 frag6_init(); 188 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 189 } 190 191 static void 192 ip6_init2(void *dummy) 193 { 194 195 /* nd6_timer_init */ 196 callout_init(&nd6_timer_ch, 0); 197 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 198 199 /* timer for regeneranation of temporary addresses randomize ID */ 200 callout_init(&in6_tmpaddrtimer_ch, 0); 201 callout_reset(&in6_tmpaddrtimer_ch, 202 (ip6_temp_preferred_lifetime - ip6_desync_factor - 203 ip6_temp_regen_advance) * hz, 204 in6_tmpaddrtimer, NULL); 205 } 206 207 /* cheat */ 208 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 209 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 210 211 extern struct route_in6 ip6_forward_rt; 212 213 void 214 ip6_input(struct mbuf *m) 215 { 216 struct ip6_hdr *ip6; 217 int off = sizeof(struct ip6_hdr), nest; 218 u_int32_t plen; 219 u_int32_t rtalert = ~0; 220 int nxt, ours = 0; 221 struct ifnet *deliverifp = NULL; 222 struct in6_addr odst; 223 int srcrt = 0; 224 225 #ifdef IPSEC 226 /* 227 * should the inner packet be considered authentic? 228 * see comment in ah4_input(). 229 * NB: m cannot be NULL when passed to the input routine 230 */ 231 232 m->m_flags &= ~M_AUTHIPHDR; 233 m->m_flags &= ~M_AUTHIPDGM; 234 235 #endif /* IPSEC */ 236 237 /* 238 * make sure we don't have onion peering information into m_tag. 239 */ 240 ip6_delaux(m); 241 242 /* 243 * mbuf statistics 244 */ 245 if (m->m_flags & M_EXT) { 246 if (m->m_next) 247 ip6stat.ip6s_mext2m++; 248 else 249 ip6stat.ip6s_mext1++; 250 } else { 251 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 252 if (m->m_next) { 253 if (m->m_flags & M_LOOP) { 254 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 255 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 256 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 257 else 258 ip6stat.ip6s_m2m[0]++; 259 } else 260 ip6stat.ip6s_m1++; 261 #undef M2MMAX 262 } 263 264 /* drop the packet if IPv6 operation is disabled on the IF */ 265 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 266 m_freem(m); 267 return; 268 } 269 270 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 271 ip6stat.ip6s_total++; 272 273 #ifndef PULLDOWN_TEST 274 /* 275 * L2 bridge code and some other code can return mbuf chain 276 * that does not conform to KAME requirement. too bad. 277 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 278 */ 279 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 280 struct mbuf *n; 281 282 MGETHDR(n, M_DONTWAIT, MT_HEADER); 283 if (n) 284 M_MOVE_PKTHDR(n, m); 285 if (n && n->m_pkthdr.len > MHLEN) { 286 MCLGET(n, M_DONTWAIT); 287 if ((n->m_flags & M_EXT) == 0) { 288 m_freem(n); 289 n = NULL; 290 } 291 } 292 if (n == NULL) { 293 m_freem(m); 294 return; /* ENOBUFS */ 295 } 296 297 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 298 n->m_len = n->m_pkthdr.len; 299 m_freem(m); 300 m = n; 301 } 302 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 303 #endif 304 305 if (m->m_len < sizeof(struct ip6_hdr)) { 306 struct ifnet *inifp; 307 inifp = m->m_pkthdr.rcvif; 308 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 309 ip6stat.ip6s_toosmall++; 310 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 311 return; 312 } 313 } 314 315 ip6 = mtod(m, struct ip6_hdr *); 316 317 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 318 ip6stat.ip6s_badvers++; 319 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 320 goto bad; 321 } 322 323 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 324 325 /* 326 * Check against address spoofing/corruption. 327 */ 328 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 329 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 330 /* 331 * XXX: "badscope" is not very suitable for a multicast source. 332 */ 333 ip6stat.ip6s_badscope++; 334 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 335 goto bad; 336 } 337 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 338 !(m->m_flags & M_LOOP)) { 339 /* 340 * In this case, the packet should come from the loopback 341 * interface. However, we cannot just check the if_flags, 342 * because ip6_mloopback() passes the "actual" interface 343 * as the outgoing/incoming interface. 344 */ 345 ip6stat.ip6s_badscope++; 346 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 347 goto bad; 348 } 349 350 #ifdef ALTQ 351 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 352 /* packet is dropped by traffic conditioner */ 353 return; 354 } 355 #endif 356 /* 357 * The following check is not documented in specs. A malicious 358 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 359 * and bypass security checks (act as if it was from 127.0.0.1 by using 360 * IPv6 src ::ffff:127.0.0.1). Be cautious. 361 * 362 * This check chokes if we are in an SIIT cloud. As none of BSDs 363 * support IPv4-less kernel compilation, we cannot support SIIT 364 * environment at all. So, it makes more sense for us to reject any 365 * malicious packets for non-SIIT environment, than try to do a 366 * partial support for SIIT environment. 367 */ 368 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 369 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 370 ip6stat.ip6s_badscope++; 371 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 372 goto bad; 373 } 374 #if 0 375 /* 376 * Reject packets with IPv4 compatible addresses (auto tunnel). 377 * 378 * The code forbids auto tunnel relay case in RFC1933 (the check is 379 * stronger than RFC1933). We may want to re-enable it if mech-xx 380 * is revised to forbid relaying case. 381 */ 382 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 383 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 384 ip6stat.ip6s_badscope++; 385 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 386 goto bad; 387 } 388 #endif 389 390 /* 391 * Run through list of hooks for input packets. 392 * 393 * NB: Beware of the destination address changing 394 * (e.g. by NAT rewriting). When this happens, 395 * tell ip6_forward to do the right thing. 396 */ 397 odst = ip6->ip6_dst; 398 399 /* Jump over all PFIL processing if hooks are not active. */ 400 if (!PFIL_HOOKED(&inet6_pfil_hook)) 401 goto passin; 402 403 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 404 return; 405 if (m == NULL) /* consumed by filter */ 406 return; 407 ip6 = mtod(m, struct ip6_hdr *); 408 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 409 410 passin: 411 /* 412 * Disambiguate address scope zones (if there is ambiguity). 413 * We first make sure that the original source or destination address 414 * is not in our internal form for scoped addresses. Such addresses 415 * are not necessarily invalid spec-wise, but we cannot accept them due 416 * to the usage conflict. 417 * in6_setscope() then also checks and rejects the cases where src or 418 * dst are the loopback address and the receiving interface 419 * is not loopback. 420 */ 421 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 422 ip6stat.ip6s_badscope++; /* XXX */ 423 goto bad; 424 } 425 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 426 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 427 ip6stat.ip6s_badscope++; 428 goto bad; 429 } 430 431 /* 432 * Multicast check 433 */ 434 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 435 struct in6_multi *in6m = 0; 436 437 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 438 /* 439 * See if we belong to the destination multicast group on the 440 * arrival interface. 441 */ 442 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 443 if (in6m) 444 ours = 1; 445 else if (!ip6_mrouter) { 446 ip6stat.ip6s_notmember++; 447 ip6stat.ip6s_cantforward++; 448 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 449 goto bad; 450 } 451 deliverifp = m->m_pkthdr.rcvif; 452 goto hbhcheck; 453 } 454 455 /* 456 * Unicast check 457 */ 458 if (ip6_forward_rt.ro_rt != NULL && 459 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 460 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 461 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 462 ip6stat.ip6s_forward_cachehit++; 463 else { 464 struct sockaddr_in6 *dst6; 465 466 if (ip6_forward_rt.ro_rt) { 467 /* route is down or destination is different */ 468 ip6stat.ip6s_forward_cachemiss++; 469 RTFREE(ip6_forward_rt.ro_rt); 470 ip6_forward_rt.ro_rt = 0; 471 } 472 473 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 474 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 475 dst6->sin6_len = sizeof(struct sockaddr_in6); 476 dst6->sin6_family = AF_INET6; 477 dst6->sin6_addr = ip6->ip6_dst; 478 479 rtalloc((struct route *)&ip6_forward_rt); 480 } 481 482 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 483 484 /* 485 * Accept the packet if the forwarding interface to the destination 486 * according to the routing table is the loopback interface, 487 * unless the associated route has a gateway. 488 * Note that this approach causes to accept a packet if there is a 489 * route to the loopback interface for the destination of the packet. 490 * But we think it's even useful in some situations, e.g. when using 491 * a special daemon which wants to intercept the packet. 492 * 493 * XXX: some OSes automatically make a cloned route for the destination 494 * of an outgoing packet. If the outgoing interface of the packet 495 * is a loopback one, the kernel would consider the packet to be 496 * accepted, even if we have no such address assinged on the interface. 497 * We check the cloned flag of the route entry to reject such cases, 498 * assuming that route entries for our own addresses are not made by 499 * cloning (it should be true because in6_addloop explicitly installs 500 * the host route). However, we might have to do an explicit check 501 * while it would be less efficient. Or, should we rather install a 502 * reject route for such a case? 503 */ 504 if (ip6_forward_rt.ro_rt && 505 (ip6_forward_rt.ro_rt->rt_flags & 506 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 507 #ifdef RTF_WASCLONED 508 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 509 #endif 510 #ifdef RTF_CLONED 511 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 512 #endif 513 #if 0 514 /* 515 * The check below is redundant since the comparison of 516 * the destination and the key of the rtentry has 517 * already done through looking up the routing table. 518 */ 519 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 520 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 521 #endif 522 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 523 struct in6_ifaddr *ia6 = 524 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 525 526 /* 527 * record address information into m_tag. 528 */ 529 (void)ip6_setdstifaddr(m, ia6); 530 531 /* 532 * packets to a tentative, duplicated, or somehow invalid 533 * address must not be accepted. 534 */ 535 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 536 /* this address is ready */ 537 ours = 1; 538 deliverifp = ia6->ia_ifp; /* correct? */ 539 /* Count the packet in the ip address stats */ 540 ia6->ia_ifa.if_ipackets++; 541 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 542 goto hbhcheck; 543 } else { 544 char ip6bufs[INET6_ADDRSTRLEN]; 545 char ip6bufd[INET6_ADDRSTRLEN]; 546 /* address is not ready, so discard the packet. */ 547 nd6log((LOG_INFO, 548 "ip6_input: packet to an unready address %s->%s\n", 549 ip6_sprintf(ip6bufs, &ip6->ip6_src), 550 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 551 552 goto bad; 553 } 554 } 555 556 /* 557 * FAITH (Firewall Aided Internet Translator) 558 */ 559 if (ip6_keepfaith) { 560 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 561 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 562 /* XXX do we need more sanity checks? */ 563 ours = 1; 564 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 565 goto hbhcheck; 566 } 567 } 568 569 /* 570 * Now there is no reason to process the packet if it's not our own 571 * and we're not a router. 572 */ 573 if (!ip6_forwarding) { 574 ip6stat.ip6s_cantforward++; 575 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 576 goto bad; 577 } 578 579 hbhcheck: 580 /* 581 * record address information into m_tag, if we don't have one yet. 582 * note that we are unable to record it, if the address is not listed 583 * as our interface address (e.g. multicast addresses, addresses 584 * within FAITH prefixes and such). 585 */ 586 if (deliverifp && !ip6_getdstifaddr(m)) { 587 struct in6_ifaddr *ia6; 588 589 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 590 if (ia6) { 591 if (!ip6_setdstifaddr(m, ia6)) { 592 /* 593 * XXX maybe we should drop the packet here, 594 * as we could not provide enough information 595 * to the upper layers. 596 */ 597 } 598 } 599 } 600 601 /* 602 * Process Hop-by-Hop options header if it's contained. 603 * m may be modified in ip6_hopopts_input(). 604 * If a JumboPayload option is included, plen will also be modified. 605 */ 606 plen = (u_int32_t)ntohs(ip6->ip6_plen); 607 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 608 struct ip6_hbh *hbh; 609 610 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 611 #if 0 /*touches NULL pointer*/ 612 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 613 #endif 614 return; /* m have already been freed */ 615 } 616 617 /* adjust pointer */ 618 ip6 = mtod(m, struct ip6_hdr *); 619 620 /* 621 * if the payload length field is 0 and the next header field 622 * indicates Hop-by-Hop Options header, then a Jumbo Payload 623 * option MUST be included. 624 */ 625 if (ip6->ip6_plen == 0 && plen == 0) { 626 /* 627 * Note that if a valid jumbo payload option is 628 * contained, ip6_hopopts_input() must set a valid 629 * (non-zero) payload length to the variable plen. 630 */ 631 ip6stat.ip6s_badoptions++; 632 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 633 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 634 icmp6_error(m, ICMP6_PARAM_PROB, 635 ICMP6_PARAMPROB_HEADER, 636 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 637 return; 638 } 639 #ifndef PULLDOWN_TEST 640 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 641 hbh = (struct ip6_hbh *)(ip6 + 1); 642 #else 643 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 644 sizeof(struct ip6_hbh)); 645 if (hbh == NULL) { 646 ip6stat.ip6s_tooshort++; 647 return; 648 } 649 #endif 650 nxt = hbh->ip6h_nxt; 651 652 /* 653 * If we are acting as a router and the packet contains a 654 * router alert option, see if we know the option value. 655 * Currently, we only support the option value for MLD, in which 656 * case we should pass the packet to the multicast routing 657 * daemon. 658 */ 659 if (rtalert != ~0 && ip6_forwarding) { 660 switch (rtalert) { 661 case IP6OPT_RTALERT_MLD: 662 ours = 1; 663 break; 664 default: 665 /* 666 * RFC2711 requires unrecognized values must be 667 * silently ignored. 668 */ 669 break; 670 } 671 } 672 } else 673 nxt = ip6->ip6_nxt; 674 675 /* 676 * Check that the amount of data in the buffers 677 * is as at least much as the IPv6 header would have us expect. 678 * Trim mbufs if longer than we expect. 679 * Drop packet if shorter than we expect. 680 */ 681 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 682 ip6stat.ip6s_tooshort++; 683 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 684 goto bad; 685 } 686 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 687 if (m->m_len == m->m_pkthdr.len) { 688 m->m_len = sizeof(struct ip6_hdr) + plen; 689 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 690 } else 691 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 692 } 693 694 /* 695 * Forward if desirable. 696 */ 697 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 698 /* 699 * If we are acting as a multicast router, all 700 * incoming multicast packets are passed to the 701 * kernel-level multicast forwarding function. 702 * The packet is returned (relatively) intact; if 703 * ip6_mforward() returns a non-zero value, the packet 704 * must be discarded, else it may be accepted below. 705 */ 706 if (ip6_mrouter && ip6_mforward && 707 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 708 ip6stat.ip6s_cantforward++; 709 m_freem(m); 710 return; 711 } 712 if (!ours) { 713 m_freem(m); 714 return; 715 } 716 } else if (!ours) { 717 ip6_forward(m, srcrt); 718 return; 719 } 720 721 ip6 = mtod(m, struct ip6_hdr *); 722 723 /* 724 * Malicious party may be able to use IPv4 mapped addr to confuse 725 * tcp/udp stack and bypass security checks (act as if it was from 726 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 727 * 728 * For SIIT end node behavior, you may want to disable the check. 729 * However, you will become vulnerable to attacks using IPv4 mapped 730 * source. 731 */ 732 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 733 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 734 ip6stat.ip6s_badscope++; 735 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 736 goto bad; 737 } 738 739 /* 740 * Tell launch routine the next header 741 */ 742 ip6stat.ip6s_delivered++; 743 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 744 nest = 0; 745 746 while (nxt != IPPROTO_DONE) { 747 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 748 ip6stat.ip6s_toomanyhdr++; 749 goto bad; 750 } 751 752 /* 753 * protection against faulty packet - there should be 754 * more sanity checks in header chain processing. 755 */ 756 if (m->m_pkthdr.len < off) { 757 ip6stat.ip6s_tooshort++; 758 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 759 goto bad; 760 } 761 762 #ifdef IPSEC 763 /* 764 * enforce IPsec policy checking if we are seeing last header. 765 * note that we do not visit this with protocols with pcb layer 766 * code - like udp/tcp/raw ip. 767 */ 768 if (ip6_ipsec_input(m, nxt)) 769 goto bad; 770 #endif /* IPSEC */ 771 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 772 } 773 return; 774 bad: 775 m_freem(m); 776 } 777 778 /* 779 * set/grab in6_ifaddr correspond to IPv6 destination address. 780 * XXX backward compatibility wrapper 781 */ 782 static struct ip6aux * 783 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 784 { 785 struct ip6aux *ip6a; 786 787 ip6a = ip6_addaux(m); 788 if (ip6a) 789 ip6a->ip6a_dstia6 = ia6; 790 return ip6a; /* NULL if failed to set */ 791 } 792 793 struct in6_ifaddr * 794 ip6_getdstifaddr(struct mbuf *m) 795 { 796 struct ip6aux *ip6a; 797 798 ip6a = ip6_findaux(m); 799 if (ip6a) 800 return ip6a->ip6a_dstia6; 801 else 802 return NULL; 803 } 804 805 /* 806 * Hop-by-Hop options header processing. If a valid jumbo payload option is 807 * included, the real payload length will be stored in plenp. 808 * 809 * rtalertp - XXX: should be stored more smart way 810 */ 811 static int 812 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 813 struct mbuf **mp, 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(struct mbuf *m, u_int8_t *opthead, int hbhlen, 868 u_int32_t *rtalertp, u_int32_t *plenp) 869 { 870 struct ip6_hdr *ip6; 871 int optlen = 0; 872 u_int8_t *opt = opthead; 873 u_int16_t rtalert_val; 874 u_int32_t jumboplen; 875 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 876 877 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 878 switch (*opt) { 879 case IP6OPT_PAD1: 880 optlen = 1; 881 break; 882 case IP6OPT_PADN: 883 if (hbhlen < IP6OPT_MINLEN) { 884 ip6stat.ip6s_toosmall++; 885 goto bad; 886 } 887 optlen = *(opt + 1) + 2; 888 break; 889 case IP6OPT_ROUTER_ALERT: 890 /* XXX may need check for alignment */ 891 if (hbhlen < IP6OPT_RTALERT_LEN) { 892 ip6stat.ip6s_toosmall++; 893 goto bad; 894 } 895 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 896 /* XXX stat */ 897 icmp6_error(m, ICMP6_PARAM_PROB, 898 ICMP6_PARAMPROB_HEADER, 899 erroff + opt + 1 - opthead); 900 return (-1); 901 } 902 optlen = IP6OPT_RTALERT_LEN; 903 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 904 *rtalertp = ntohs(rtalert_val); 905 break; 906 case IP6OPT_JUMBO: 907 /* XXX may need check for alignment */ 908 if (hbhlen < IP6OPT_JUMBO_LEN) { 909 ip6stat.ip6s_toosmall++; 910 goto bad; 911 } 912 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 913 /* XXX stat */ 914 icmp6_error(m, ICMP6_PARAM_PROB, 915 ICMP6_PARAMPROB_HEADER, 916 erroff + opt + 1 - opthead); 917 return (-1); 918 } 919 optlen = IP6OPT_JUMBO_LEN; 920 921 /* 922 * IPv6 packets that have non 0 payload length 923 * must not contain a jumbo payload option. 924 */ 925 ip6 = mtod(m, struct ip6_hdr *); 926 if (ip6->ip6_plen) { 927 ip6stat.ip6s_badoptions++; 928 icmp6_error(m, ICMP6_PARAM_PROB, 929 ICMP6_PARAMPROB_HEADER, 930 erroff + opt - opthead); 931 return (-1); 932 } 933 934 /* 935 * We may see jumbolen in unaligned location, so 936 * we'd need to perform bcopy(). 937 */ 938 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 939 jumboplen = (u_int32_t)htonl(jumboplen); 940 941 #if 1 942 /* 943 * if there are multiple jumbo payload options, 944 * *plenp will be non-zero and the packet will be 945 * rejected. 946 * the behavior may need some debate in ipngwg - 947 * multiple options does not make sense, however, 948 * there's no explicit mention in specification. 949 */ 950 if (*plenp != 0) { 951 ip6stat.ip6s_badoptions++; 952 icmp6_error(m, ICMP6_PARAM_PROB, 953 ICMP6_PARAMPROB_HEADER, 954 erroff + opt + 2 - opthead); 955 return (-1); 956 } 957 #endif 958 959 /* 960 * jumbo payload length must be larger than 65535. 961 */ 962 if (jumboplen <= IPV6_MAXPACKET) { 963 ip6stat.ip6s_badoptions++; 964 icmp6_error(m, ICMP6_PARAM_PROB, 965 ICMP6_PARAMPROB_HEADER, 966 erroff + opt + 2 - opthead); 967 return (-1); 968 } 969 *plenp = jumboplen; 970 971 break; 972 default: /* unknown option */ 973 if (hbhlen < IP6OPT_MINLEN) { 974 ip6stat.ip6s_toosmall++; 975 goto bad; 976 } 977 optlen = ip6_unknown_opt(opt, m, 978 erroff + opt - opthead); 979 if (optlen == -1) 980 return (-1); 981 optlen += 2; 982 break; 983 } 984 } 985 986 return (0); 987 988 bad: 989 m_freem(m); 990 return (-1); 991 } 992 993 /* 994 * Unknown option processing. 995 * The third argument `off' is the offset from the IPv6 header to the option, 996 * which is necessary if the IPv6 header the and option header and IPv6 header 997 * is not continuous in order to return an ICMPv6 error. 998 */ 999 int 1000 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1001 { 1002 struct ip6_hdr *ip6; 1003 1004 switch (IP6OPT_TYPE(*optp)) { 1005 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1006 return ((int)*(optp + 1)); 1007 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1008 m_freem(m); 1009 return (-1); 1010 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1011 ip6stat.ip6s_badoptions++; 1012 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1013 return (-1); 1014 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1015 ip6stat.ip6s_badoptions++; 1016 ip6 = mtod(m, struct ip6_hdr *); 1017 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1018 (m->m_flags & (M_BCAST|M_MCAST))) 1019 m_freem(m); 1020 else 1021 icmp6_error(m, ICMP6_PARAM_PROB, 1022 ICMP6_PARAMPROB_OPTION, off); 1023 return (-1); 1024 } 1025 1026 m_freem(m); /* XXX: NOTREACHED */ 1027 return (-1); 1028 } 1029 1030 /* 1031 * Create the "control" list for this pcb. 1032 * These functions will not modify mbuf chain at all. 1033 * 1034 * With KAME mbuf chain restriction: 1035 * The routine will be called from upper layer handlers like tcp6_input(). 1036 * Thus the routine assumes that the caller (tcp6_input) have already 1037 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1038 * very first mbuf on the mbuf chain. 1039 * 1040 * ip6_savecontrol_v4 will handle those options that are possible to be 1041 * set on a v4-mapped socket. 1042 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1043 * options and handle the v6-only ones itself. 1044 */ 1045 int 1046 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp) 1047 { 1048 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1049 1050 #ifdef SO_TIMESTAMP 1051 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1052 struct timeval tv; 1053 1054 microtime(&tv); 1055 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1056 SCM_TIMESTAMP, SOL_SOCKET); 1057 if (*mp) 1058 mp = &(*mp)->m_next; 1059 } 1060 #endif 1061 1062 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1063 return (1); 1064 1065 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1066 /* RFC 2292 sec. 5 */ 1067 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1068 struct in6_pktinfo pi6; 1069 1070 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1071 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1072 pi6.ipi6_ifindex = 1073 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1074 1075 *mp = sbcreatecontrol((caddr_t) &pi6, 1076 sizeof(struct in6_pktinfo), 1077 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1078 if (*mp) 1079 mp = &(*mp)->m_next; 1080 } 1081 1082 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1083 int hlim = ip6->ip6_hlim & 0xff; 1084 1085 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1086 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1087 IPPROTO_IPV6); 1088 if (*mp) 1089 mp = &(*mp)->m_next; 1090 } 1091 1092 return (0); 1093 } 1094 1095 void 1096 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1097 { 1098 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1099 1100 if (ip6_savecontrol_v4(in6p, m, mp) != 0) 1101 return; 1102 1103 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1104 u_int32_t flowinfo; 1105 int tclass; 1106 1107 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1108 flowinfo >>= 20; 1109 1110 tclass = flowinfo & 0xff; 1111 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1112 IPV6_TCLASS, IPPROTO_IPV6); 1113 if (*mp) 1114 mp = &(*mp)->m_next; 1115 } 1116 1117 /* 1118 * IPV6_HOPOPTS socket option. Recall that we required super-user 1119 * privilege for the option (see ip6_ctloutput), but it might be too 1120 * strict, since there might be some hop-by-hop options which can be 1121 * returned to normal user. 1122 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1123 */ 1124 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1125 /* 1126 * Check if a hop-by-hop options header is contatined in the 1127 * received packet, and if so, store the options as ancillary 1128 * data. Note that a hop-by-hop options header must be 1129 * just after the IPv6 header, which is assured through the 1130 * IPv6 input processing. 1131 */ 1132 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1133 struct ip6_hbh *hbh; 1134 int hbhlen = 0; 1135 #ifdef PULLDOWN_TEST 1136 struct mbuf *ext; 1137 #endif 1138 1139 #ifndef PULLDOWN_TEST 1140 hbh = (struct ip6_hbh *)(ip6 + 1); 1141 hbhlen = (hbh->ip6h_len + 1) << 3; 1142 #else 1143 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1144 ip6->ip6_nxt); 1145 if (ext == NULL) { 1146 ip6stat.ip6s_tooshort++; 1147 return; 1148 } 1149 hbh = mtod(ext, struct ip6_hbh *); 1150 hbhlen = (hbh->ip6h_len + 1) << 3; 1151 if (hbhlen != ext->m_len) { 1152 m_freem(ext); 1153 ip6stat.ip6s_tooshort++; 1154 return; 1155 } 1156 #endif 1157 1158 /* 1159 * XXX: We copy the whole header even if a 1160 * jumbo payload option is included, the option which 1161 * is to be removed before returning according to 1162 * RFC2292. 1163 * Note: this constraint is removed in RFC3542 1164 */ 1165 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1166 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1167 IPPROTO_IPV6); 1168 if (*mp) 1169 mp = &(*mp)->m_next; 1170 #ifdef PULLDOWN_TEST 1171 m_freem(ext); 1172 #endif 1173 } 1174 } 1175 1176 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1177 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1178 1179 /* 1180 * Search for destination options headers or routing 1181 * header(s) through the header chain, and stores each 1182 * header as ancillary data. 1183 * Note that the order of the headers remains in 1184 * the chain of ancillary data. 1185 */ 1186 while (1) { /* is explicit loop prevention necessary? */ 1187 struct ip6_ext *ip6e = NULL; 1188 int elen; 1189 #ifdef PULLDOWN_TEST 1190 struct mbuf *ext = NULL; 1191 #endif 1192 1193 /* 1194 * if it is not an extension header, don't try to 1195 * pull it from the chain. 1196 */ 1197 switch (nxt) { 1198 case IPPROTO_DSTOPTS: 1199 case IPPROTO_ROUTING: 1200 case IPPROTO_HOPOPTS: 1201 case IPPROTO_AH: /* is it possible? */ 1202 break; 1203 default: 1204 goto loopend; 1205 } 1206 1207 #ifndef PULLDOWN_TEST 1208 if (off + sizeof(*ip6e) > m->m_len) 1209 goto loopend; 1210 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1211 if (nxt == IPPROTO_AH) 1212 elen = (ip6e->ip6e_len + 2) << 2; 1213 else 1214 elen = (ip6e->ip6e_len + 1) << 3; 1215 if (off + elen > m->m_len) 1216 goto loopend; 1217 #else 1218 ext = ip6_pullexthdr(m, off, nxt); 1219 if (ext == NULL) { 1220 ip6stat.ip6s_tooshort++; 1221 return; 1222 } 1223 ip6e = mtod(ext, struct ip6_ext *); 1224 if (nxt == IPPROTO_AH) 1225 elen = (ip6e->ip6e_len + 2) << 2; 1226 else 1227 elen = (ip6e->ip6e_len + 1) << 3; 1228 if (elen != ext->m_len) { 1229 m_freem(ext); 1230 ip6stat.ip6s_tooshort++; 1231 return; 1232 } 1233 #endif 1234 1235 switch (nxt) { 1236 case IPPROTO_DSTOPTS: 1237 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1238 break; 1239 1240 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1241 IS2292(in6p, 1242 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1243 IPPROTO_IPV6); 1244 if (*mp) 1245 mp = &(*mp)->m_next; 1246 break; 1247 case IPPROTO_ROUTING: 1248 if (!in6p->in6p_flags & IN6P_RTHDR) 1249 break; 1250 1251 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1252 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1253 IPPROTO_IPV6); 1254 if (*mp) 1255 mp = &(*mp)->m_next; 1256 break; 1257 case IPPROTO_HOPOPTS: 1258 case IPPROTO_AH: /* is it possible? */ 1259 break; 1260 1261 default: 1262 /* 1263 * other cases have been filtered in the above. 1264 * none will visit this case. here we supply 1265 * the code just in case (nxt overwritten or 1266 * other cases). 1267 */ 1268 #ifdef PULLDOWN_TEST 1269 m_freem(ext); 1270 #endif 1271 goto loopend; 1272 1273 } 1274 1275 /* proceed with the next header. */ 1276 off += elen; 1277 nxt = ip6e->ip6e_nxt; 1278 ip6e = NULL; 1279 #ifdef PULLDOWN_TEST 1280 m_freem(ext); 1281 ext = NULL; 1282 #endif 1283 } 1284 loopend: 1285 ; 1286 } 1287 } 1288 #undef IS2292 1289 1290 void 1291 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1292 { 1293 struct socket *so; 1294 struct mbuf *m_mtu; 1295 struct ip6_mtuinfo mtuctl; 1296 1297 so = in6p->inp_socket; 1298 1299 if (mtu == NULL) 1300 return; 1301 1302 #ifdef DIAGNOSTIC 1303 if (so == NULL) /* I believe this is impossible */ 1304 panic("ip6_notify_pmtu: socket is NULL"); 1305 #endif 1306 1307 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1308 mtuctl.ip6m_mtu = *mtu; 1309 mtuctl.ip6m_addr = *dst; 1310 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1311 return; 1312 1313 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1314 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1315 return; 1316 1317 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1318 == 0) { 1319 m_freem(m_mtu); 1320 /* XXX: should count statistics */ 1321 } else 1322 sorwakeup(so); 1323 1324 return; 1325 } 1326 1327 #ifdef PULLDOWN_TEST 1328 /* 1329 * pull single extension header from mbuf chain. returns single mbuf that 1330 * contains the result, or NULL on error. 1331 */ 1332 static struct mbuf * 1333 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1334 { 1335 struct ip6_ext ip6e; 1336 size_t elen; 1337 struct mbuf *n; 1338 1339 #ifdef DIAGNOSTIC 1340 switch (nxt) { 1341 case IPPROTO_DSTOPTS: 1342 case IPPROTO_ROUTING: 1343 case IPPROTO_HOPOPTS: 1344 case IPPROTO_AH: /* is it possible? */ 1345 break; 1346 default: 1347 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1348 } 1349 #endif 1350 1351 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1352 if (nxt == IPPROTO_AH) 1353 elen = (ip6e.ip6e_len + 2) << 2; 1354 else 1355 elen = (ip6e.ip6e_len + 1) << 3; 1356 1357 MGET(n, M_DONTWAIT, MT_DATA); 1358 if (n && elen >= MLEN) { 1359 MCLGET(n, M_DONTWAIT); 1360 if ((n->m_flags & M_EXT) == 0) { 1361 m_free(n); 1362 n = NULL; 1363 } 1364 } 1365 if (!n) 1366 return NULL; 1367 1368 n->m_len = 0; 1369 if (elen >= M_TRAILINGSPACE(n)) { 1370 m_free(n); 1371 return NULL; 1372 } 1373 1374 m_copydata(m, off, elen, mtod(n, caddr_t)); 1375 n->m_len = elen; 1376 return n; 1377 } 1378 #endif 1379 1380 /* 1381 * Get pointer to the previous header followed by the header 1382 * currently processed. 1383 * XXX: This function supposes that 1384 * M includes all headers, 1385 * the next header field and the header length field of each header 1386 * are valid, and 1387 * the sum of each header length equals to OFF. 1388 * Because of these assumptions, this function must be called very 1389 * carefully. Moreover, it will not be used in the near future when 1390 * we develop `neater' mechanism to process extension headers. 1391 */ 1392 char * 1393 ip6_get_prevhdr(struct mbuf *m, 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(struct mbuf *m, int off, int proto, int *nxtp) 1433 { 1434 struct ip6_hdr ip6; 1435 struct ip6_ext ip6e; 1436 struct ip6_frag fh; 1437 1438 /* just in case */ 1439 if (m == NULL) 1440 panic("ip6_nexthdr: m == NULL"); 1441 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1442 return -1; 1443 1444 switch (proto) { 1445 case IPPROTO_IPV6: 1446 if (m->m_pkthdr.len < off + sizeof(ip6)) 1447 return -1; 1448 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1449 if (nxtp) 1450 *nxtp = ip6.ip6_nxt; 1451 off += sizeof(ip6); 1452 return off; 1453 1454 case IPPROTO_FRAGMENT: 1455 /* 1456 * terminate parsing if it is not the first fragment, 1457 * it does not make sense to parse through it. 1458 */ 1459 if (m->m_pkthdr.len < off + sizeof(fh)) 1460 return -1; 1461 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1462 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1463 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1464 return -1; 1465 if (nxtp) 1466 *nxtp = fh.ip6f_nxt; 1467 off += sizeof(struct ip6_frag); 1468 return off; 1469 1470 case IPPROTO_AH: 1471 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1472 return -1; 1473 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1474 if (nxtp) 1475 *nxtp = ip6e.ip6e_nxt; 1476 off += (ip6e.ip6e_len + 2) << 2; 1477 return off; 1478 1479 case IPPROTO_HOPOPTS: 1480 case IPPROTO_ROUTING: 1481 case IPPROTO_DSTOPTS: 1482 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1483 return -1; 1484 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1485 if (nxtp) 1486 *nxtp = ip6e.ip6e_nxt; 1487 off += (ip6e.ip6e_len + 1) << 3; 1488 return off; 1489 1490 case IPPROTO_NONE: 1491 case IPPROTO_ESP: 1492 case IPPROTO_IPCOMP: 1493 /* give up */ 1494 return -1; 1495 1496 default: 1497 return -1; 1498 } 1499 1500 return -1; 1501 } 1502 1503 /* 1504 * get offset for the last header in the chain. m will be kept untainted. 1505 */ 1506 int 1507 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1508 { 1509 int newoff; 1510 int nxt; 1511 1512 if (!nxtp) { 1513 nxt = -1; 1514 nxtp = &nxt; 1515 } 1516 while (1) { 1517 newoff = ip6_nexthdr(m, off, proto, nxtp); 1518 if (newoff < 0) 1519 return off; 1520 else if (newoff < off) 1521 return -1; /* invalid */ 1522 else if (newoff == off) 1523 return newoff; 1524 1525 off = newoff; 1526 proto = *nxtp; 1527 } 1528 } 1529 1530 struct ip6aux * 1531 ip6_addaux(struct mbuf *m) 1532 { 1533 struct m_tag *mtag; 1534 1535 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1536 if (!mtag) { 1537 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1538 M_NOWAIT); 1539 if (mtag) { 1540 m_tag_prepend(m, mtag); 1541 bzero(mtag + 1, sizeof(struct ip6aux)); 1542 } 1543 } 1544 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1545 } 1546 1547 struct ip6aux * 1548 ip6_findaux(struct mbuf *m) 1549 { 1550 struct m_tag *mtag; 1551 1552 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1553 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1554 } 1555 1556 void 1557 ip6_delaux(struct mbuf *m) 1558 { 1559 struct m_tag *mtag; 1560 1561 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1562 if (mtag) 1563 m_tag_delete(m, mtag); 1564 } 1565 1566 /* 1567 * System control for IP6 1568 */ 1569 1570 u_char inet6ctlerrmap[PRC_NCMDS] = { 1571 0, 0, 0, 0, 1572 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1573 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1574 EMSGSIZE, EHOSTUNREACH, 0, 0, 1575 0, 0, 0, 0, 1576 ENOPROTOOPT 1577 }; 1578