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 * If we are acting as a router and the packet contains a 661 * router alert option, see if we know the option value. 662 * Currently, we only support the option value for MLD, in which 663 * case we should pass the packet to the multicast routing 664 * daemon. 665 */ 666 if (rtalert != ~0 && ip6_forwarding) { 667 switch (rtalert) { 668 case IP6OPT_RTALERT_MLD: 669 ours = 1; 670 break; 671 default: 672 /* 673 * RFC2711 requires unrecognized values must be 674 * silently ignored. 675 */ 676 break; 677 } 678 } 679 } else 680 nxt = ip6->ip6_nxt; 681 682 /* 683 * Check that the amount of data in the buffers 684 * is as at least much as the IPv6 header would have us expect. 685 * Trim mbufs if longer than we expect. 686 * Drop packet if shorter than we expect. 687 */ 688 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 689 ip6stat.ip6s_tooshort++; 690 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 691 goto bad; 692 } 693 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 694 if (m->m_len == m->m_pkthdr.len) { 695 m->m_len = sizeof(struct ip6_hdr) + plen; 696 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 697 } else 698 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 699 } 700 701 /* 702 * Forward if desirable. 703 */ 704 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 705 /* 706 * If we are acting as a multicast router, all 707 * incoming multicast packets are passed to the 708 * kernel-level multicast forwarding function. 709 * The packet is returned (relatively) intact; if 710 * ip6_mforward() returns a non-zero value, the packet 711 * must be discarded, else it may be accepted below. 712 */ 713 if (ip6_mrouter && ip6_mforward && 714 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 715 ip6stat.ip6s_cantforward++; 716 m_freem(m); 717 return; 718 } 719 if (!ours) { 720 m_freem(m); 721 return; 722 } 723 } else if (!ours) { 724 ip6_forward(m, srcrt); 725 return; 726 } 727 728 ip6 = mtod(m, struct ip6_hdr *); 729 730 /* 731 * Malicious party may be able to use IPv4 mapped addr to confuse 732 * tcp/udp stack and bypass security checks (act as if it was from 733 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 734 * 735 * For SIIT end node behavior, you may want to disable the check. 736 * However, you will become vulnerable to attacks using IPv4 mapped 737 * source. 738 */ 739 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 740 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 741 ip6stat.ip6s_badscope++; 742 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 743 goto bad; 744 } 745 746 /* 747 * Tell launch routine the next header 748 */ 749 ip6stat.ip6s_delivered++; 750 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 751 nest = 0; 752 753 while (nxt != IPPROTO_DONE) { 754 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 755 ip6stat.ip6s_toomanyhdr++; 756 goto bad; 757 } 758 759 /* 760 * protection against faulty packet - there should be 761 * more sanity checks in header chain processing. 762 */ 763 if (m->m_pkthdr.len < off) { 764 ip6stat.ip6s_tooshort++; 765 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 766 goto bad; 767 } 768 769 #ifdef IPSEC 770 /* 771 * enforce IPsec policy checking if we are seeing last header. 772 * note that we do not visit this with protocols with pcb layer 773 * code - like udp/tcp/raw ip. 774 */ 775 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 776 ipsec6_in_reject(m, NULL)) { 777 ipsec6stat.in_polvio++; 778 goto bad; 779 } 780 #endif 781 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 782 } 783 return; 784 bad: 785 m_freem(m); 786 } 787 788 /* 789 * set/grab in6_ifaddr correspond to IPv6 destination address. 790 * XXX backward compatibility wrapper 791 */ 792 static struct ip6aux * 793 ip6_setdstifaddr(m, ia6) 794 struct mbuf *m; 795 struct in6_ifaddr *ia6; 796 { 797 struct ip6aux *ip6a; 798 799 ip6a = ip6_addaux(m); 800 if (ip6a) 801 ip6a->ip6a_dstia6 = ia6; 802 return ip6a; /* NULL if failed to set */ 803 } 804 805 struct in6_ifaddr * 806 ip6_getdstifaddr(m) 807 struct mbuf *m; 808 { 809 struct ip6aux *ip6a; 810 811 ip6a = ip6_findaux(m); 812 if (ip6a) 813 return ip6a->ip6a_dstia6; 814 else 815 return NULL; 816 } 817 818 /* 819 * Hop-by-Hop options header processing. If a valid jumbo payload option is 820 * included, the real payload length will be stored in plenp. 821 */ 822 static int 823 ip6_hopopts_input(plenp, rtalertp, mp, offp) 824 u_int32_t *plenp; 825 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 826 struct mbuf **mp; 827 int *offp; 828 { 829 struct mbuf *m = *mp; 830 int off = *offp, hbhlen; 831 struct ip6_hbh *hbh; 832 u_int8_t *opt; 833 834 /* validation of the length of the header */ 835 #ifndef PULLDOWN_TEST 836 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 837 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 838 hbhlen = (hbh->ip6h_len + 1) << 3; 839 840 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 841 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 842 #else 843 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 844 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 845 if (hbh == NULL) { 846 ip6stat.ip6s_tooshort++; 847 return -1; 848 } 849 hbhlen = (hbh->ip6h_len + 1) << 3; 850 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 851 hbhlen); 852 if (hbh == NULL) { 853 ip6stat.ip6s_tooshort++; 854 return -1; 855 } 856 #endif 857 off += hbhlen; 858 hbhlen -= sizeof(struct ip6_hbh); 859 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 860 861 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 862 hbhlen, rtalertp, plenp) < 0) 863 return (-1); 864 865 *offp = off; 866 *mp = m; 867 return (0); 868 } 869 870 /* 871 * Search header for all Hop-by-hop options and process each option. 872 * This function is separate from ip6_hopopts_input() in order to 873 * handle a case where the sending node itself process its hop-by-hop 874 * options header. In such a case, the function is called from ip6_output(). 875 * 876 * The function assumes that hbh header is located right after the IPv6 header 877 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 878 * opthead + hbhlen is located in continuous memory region. 879 */ 880 int 881 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 882 struct mbuf *m; 883 u_int8_t *opthead; 884 int hbhlen; 885 u_int32_t *rtalertp; 886 u_int32_t *plenp; 887 { 888 struct ip6_hdr *ip6; 889 int optlen = 0; 890 u_int8_t *opt = opthead; 891 u_int16_t rtalert_val; 892 u_int32_t jumboplen; 893 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 894 895 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 896 switch (*opt) { 897 case IP6OPT_PAD1: 898 optlen = 1; 899 break; 900 case IP6OPT_PADN: 901 if (hbhlen < IP6OPT_MINLEN) { 902 ip6stat.ip6s_toosmall++; 903 goto bad; 904 } 905 optlen = *(opt + 1) + 2; 906 break; 907 case IP6OPT_ROUTER_ALERT: 908 /* XXX may need check for alignment */ 909 if (hbhlen < IP6OPT_RTALERT_LEN) { 910 ip6stat.ip6s_toosmall++; 911 goto bad; 912 } 913 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 914 /* XXX stat */ 915 icmp6_error(m, ICMP6_PARAM_PROB, 916 ICMP6_PARAMPROB_HEADER, 917 erroff + opt + 1 - opthead); 918 return (-1); 919 } 920 optlen = IP6OPT_RTALERT_LEN; 921 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 922 *rtalertp = ntohs(rtalert_val); 923 break; 924 case IP6OPT_JUMBO: 925 /* XXX may need check for alignment */ 926 if (hbhlen < IP6OPT_JUMBO_LEN) { 927 ip6stat.ip6s_toosmall++; 928 goto bad; 929 } 930 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 931 /* XXX stat */ 932 icmp6_error(m, ICMP6_PARAM_PROB, 933 ICMP6_PARAMPROB_HEADER, 934 erroff + opt + 1 - opthead); 935 return (-1); 936 } 937 optlen = IP6OPT_JUMBO_LEN; 938 939 /* 940 * IPv6 packets that have non 0 payload length 941 * must not contain a jumbo payload option. 942 */ 943 ip6 = mtod(m, struct ip6_hdr *); 944 if (ip6->ip6_plen) { 945 ip6stat.ip6s_badoptions++; 946 icmp6_error(m, ICMP6_PARAM_PROB, 947 ICMP6_PARAMPROB_HEADER, 948 erroff + opt - opthead); 949 return (-1); 950 } 951 952 /* 953 * We may see jumbolen in unaligned location, so 954 * we'd need to perform bcopy(). 955 */ 956 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 957 jumboplen = (u_int32_t)htonl(jumboplen); 958 959 #if 1 960 /* 961 * if there are multiple jumbo payload options, 962 * *plenp will be non-zero and the packet will be 963 * rejected. 964 * the behavior may need some debate in ipngwg - 965 * multiple options does not make sense, however, 966 * there's no explicit mention in specification. 967 */ 968 if (*plenp != 0) { 969 ip6stat.ip6s_badoptions++; 970 icmp6_error(m, ICMP6_PARAM_PROB, 971 ICMP6_PARAMPROB_HEADER, 972 erroff + opt + 2 - opthead); 973 return (-1); 974 } 975 #endif 976 977 /* 978 * jumbo payload length must be larger than 65535. 979 */ 980 if (jumboplen <= IPV6_MAXPACKET) { 981 ip6stat.ip6s_badoptions++; 982 icmp6_error(m, ICMP6_PARAM_PROB, 983 ICMP6_PARAMPROB_HEADER, 984 erroff + opt + 2 - opthead); 985 return (-1); 986 } 987 *plenp = jumboplen; 988 989 break; 990 default: /* unknown option */ 991 if (hbhlen < IP6OPT_MINLEN) { 992 ip6stat.ip6s_toosmall++; 993 goto bad; 994 } 995 optlen = ip6_unknown_opt(opt, m, 996 erroff + opt - opthead); 997 if (optlen == -1) 998 return (-1); 999 optlen += 2; 1000 break; 1001 } 1002 } 1003 1004 return (0); 1005 1006 bad: 1007 m_freem(m); 1008 return (-1); 1009 } 1010 1011 /* 1012 * Unknown option processing. 1013 * The third argument `off' is the offset from the IPv6 header to the option, 1014 * which is necessary if the IPv6 header the and option header and IPv6 header 1015 * is not continuous in order to return an ICMPv6 error. 1016 */ 1017 int 1018 ip6_unknown_opt(optp, m, off) 1019 u_int8_t *optp; 1020 struct mbuf *m; 1021 int off; 1022 { 1023 struct ip6_hdr *ip6; 1024 1025 switch (IP6OPT_TYPE(*optp)) { 1026 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1027 return ((int)*(optp + 1)); 1028 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1029 m_freem(m); 1030 return (-1); 1031 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1032 ip6stat.ip6s_badoptions++; 1033 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1034 return (-1); 1035 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1036 ip6stat.ip6s_badoptions++; 1037 ip6 = mtod(m, struct ip6_hdr *); 1038 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1039 (m->m_flags & (M_BCAST|M_MCAST))) 1040 m_freem(m); 1041 else 1042 icmp6_error(m, ICMP6_PARAM_PROB, 1043 ICMP6_PARAMPROB_OPTION, off); 1044 return (-1); 1045 } 1046 1047 m_freem(m); /* XXX: NOTREACHED */ 1048 return (-1); 1049 } 1050 1051 /* 1052 * Create the "control" list for this pcb. 1053 * The function will not modify mbuf chain at all. 1054 * 1055 * with KAME mbuf chain restriction: 1056 * The routine will be called from upper layer handlers like tcp6_input(). 1057 * Thus the routine assumes that the caller (tcp6_input) have already 1058 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1059 * very first mbuf on the mbuf chain. 1060 */ 1061 void 1062 ip6_savecontrol(in6p, m, mp) 1063 struct inpcb *in6p; 1064 struct mbuf *m, **mp; 1065 { 1066 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1067 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1068 1069 #ifdef SO_TIMESTAMP 1070 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1071 struct timeval tv; 1072 1073 microtime(&tv); 1074 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1075 SCM_TIMESTAMP, SOL_SOCKET); 1076 if (*mp) 1077 mp = &(*mp)->m_next; 1078 } 1079 #endif 1080 1081 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1082 return; 1083 1084 /* RFC 2292 sec. 5 */ 1085 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1086 struct in6_pktinfo pi6; 1087 1088 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1089 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1090 pi6.ipi6_ifindex = 1091 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1092 1093 *mp = sbcreatecontrol((caddr_t) &pi6, 1094 sizeof(struct in6_pktinfo), 1095 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1096 if (*mp) 1097 mp = &(*mp)->m_next; 1098 } 1099 1100 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1101 int hlim = ip6->ip6_hlim & 0xff; 1102 1103 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1104 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1105 if (*mp) 1106 mp = &(*mp)->m_next; 1107 } 1108 1109 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1110 u_int32_t flowinfo; 1111 int tclass; 1112 1113 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1114 flowinfo >>= 20; 1115 1116 tclass = flowinfo & 0xff; 1117 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1118 IPV6_TCLASS, IPPROTO_IPV6); 1119 if (*mp) 1120 mp = &(*mp)->m_next; 1121 } 1122 1123 /* 1124 * IPV6_HOPOPTS socket option. Recall that we required super-user 1125 * privilege for the option (see ip6_ctloutput), but it might be too 1126 * strict, since there might be some hop-by-hop options which can be 1127 * returned to normal user. 1128 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1129 */ 1130 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1131 /* 1132 * Check if a hop-by-hop options header is contatined in the 1133 * received packet, and if so, store the options as ancillary 1134 * data. Note that a hop-by-hop options header must be 1135 * just after the IPv6 header, which is assured through the 1136 * IPv6 input processing. 1137 */ 1138 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1139 struct ip6_hbh *hbh; 1140 int hbhlen = 0; 1141 #ifdef PULLDOWN_TEST 1142 struct mbuf *ext; 1143 #endif 1144 1145 #ifndef PULLDOWN_TEST 1146 hbh = (struct ip6_hbh *)(ip6 + 1); 1147 hbhlen = (hbh->ip6h_len + 1) << 3; 1148 #else 1149 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1150 ip6->ip6_nxt); 1151 if (ext == NULL) { 1152 ip6stat.ip6s_tooshort++; 1153 return; 1154 } 1155 hbh = mtod(ext, struct ip6_hbh *); 1156 hbhlen = (hbh->ip6h_len + 1) << 3; 1157 if (hbhlen != ext->m_len) { 1158 m_freem(ext); 1159 ip6stat.ip6s_tooshort++; 1160 return; 1161 } 1162 #endif 1163 1164 /* 1165 * XXX: We copy the whole header even if a 1166 * jumbo payload option is included, the option which 1167 * is to be removed before returning according to 1168 * RFC2292. 1169 * Note: this constraint is removed in RFC3542 1170 */ 1171 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1172 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1173 IPPROTO_IPV6); 1174 if (*mp) 1175 mp = &(*mp)->m_next; 1176 #ifdef PULLDOWN_TEST 1177 m_freem(ext); 1178 #endif 1179 } 1180 } 1181 1182 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1183 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1184 1185 /* 1186 * Search for destination options headers or routing 1187 * header(s) through the header chain, and stores each 1188 * header as ancillary data. 1189 * Note that the order of the headers remains in 1190 * the chain of ancillary data. 1191 */ 1192 while (1) { /* is explicit loop prevention necessary? */ 1193 struct ip6_ext *ip6e = NULL; 1194 int elen; 1195 #ifdef PULLDOWN_TEST 1196 struct mbuf *ext = NULL; 1197 #endif 1198 1199 /* 1200 * if it is not an extension header, don't try to 1201 * pull it from the chain. 1202 */ 1203 switch (nxt) { 1204 case IPPROTO_DSTOPTS: 1205 case IPPROTO_ROUTING: 1206 case IPPROTO_HOPOPTS: 1207 case IPPROTO_AH: /* is it possible? */ 1208 break; 1209 default: 1210 goto loopend; 1211 } 1212 1213 #ifndef PULLDOWN_TEST 1214 if (off + sizeof(*ip6e) > m->m_len) 1215 goto loopend; 1216 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1217 if (nxt == IPPROTO_AH) 1218 elen = (ip6e->ip6e_len + 2) << 2; 1219 else 1220 elen = (ip6e->ip6e_len + 1) << 3; 1221 if (off + elen > m->m_len) 1222 goto loopend; 1223 #else 1224 ext = ip6_pullexthdr(m, off, nxt); 1225 if (ext == NULL) { 1226 ip6stat.ip6s_tooshort++; 1227 return; 1228 } 1229 ip6e = mtod(ext, struct ip6_ext *); 1230 if (nxt == IPPROTO_AH) 1231 elen = (ip6e->ip6e_len + 2) << 2; 1232 else 1233 elen = (ip6e->ip6e_len + 1) << 3; 1234 if (elen != ext->m_len) { 1235 m_freem(ext); 1236 ip6stat.ip6s_tooshort++; 1237 return; 1238 } 1239 #endif 1240 1241 switch (nxt) { 1242 case IPPROTO_DSTOPTS: 1243 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1244 break; 1245 1246 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1247 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1248 IPPROTO_IPV6); 1249 if (*mp) 1250 mp = &(*mp)->m_next; 1251 break; 1252 case IPPROTO_ROUTING: 1253 if (!in6p->in6p_flags & IN6P_RTHDR) 1254 break; 1255 1256 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1257 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1258 IPPROTO_IPV6); 1259 if (*mp) 1260 mp = &(*mp)->m_next; 1261 break; 1262 case IPPROTO_HOPOPTS: 1263 case IPPROTO_AH: /* is it possible? */ 1264 break; 1265 1266 default: 1267 /* 1268 * other cases have been filtered in the above. 1269 * none will visit this case. here we supply 1270 * the code just in case (nxt overwritten or 1271 * other cases). 1272 */ 1273 #ifdef PULLDOWN_TEST 1274 m_freem(ext); 1275 #endif 1276 goto loopend; 1277 1278 } 1279 1280 /* proceed with the next header. */ 1281 off += elen; 1282 nxt = ip6e->ip6e_nxt; 1283 ip6e = NULL; 1284 #ifdef PULLDOWN_TEST 1285 m_freem(ext); 1286 ext = NULL; 1287 #endif 1288 } 1289 loopend: 1290 ; 1291 } 1292 1293 #undef IS2292 1294 } 1295 1296 void 1297 ip6_notify_pmtu(in6p, dst, mtu) 1298 struct inpcb *in6p; 1299 struct sockaddr_in6 *dst; 1300 u_int32_t *mtu; 1301 { 1302 struct socket *so; 1303 struct mbuf *m_mtu; 1304 struct ip6_mtuinfo mtuctl; 1305 1306 so = in6p->inp_socket; 1307 1308 if (mtu == NULL) 1309 return; 1310 1311 #ifdef DIAGNOSTIC 1312 if (so == NULL) /* I believe this is impossible */ 1313 panic("ip6_notify_pmtu: socket is NULL"); 1314 #endif 1315 1316 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1317 mtuctl.ip6m_mtu = *mtu; 1318 mtuctl.ip6m_addr = *dst; 1319 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1320 return; 1321 1322 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1323 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1324 return; 1325 1326 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1327 == 0) { 1328 m_freem(m_mtu); 1329 /* XXX: should count statistics */ 1330 } else 1331 sorwakeup(so); 1332 1333 return; 1334 } 1335 1336 #ifdef PULLDOWN_TEST 1337 /* 1338 * pull single extension header from mbuf chain. returns single mbuf that 1339 * contains the result, or NULL on error. 1340 */ 1341 static struct mbuf * 1342 ip6_pullexthdr(m, off, nxt) 1343 struct mbuf *m; 1344 size_t off; 1345 int nxt; 1346 { 1347 struct ip6_ext ip6e; 1348 size_t elen; 1349 struct mbuf *n; 1350 1351 #ifdef DIAGNOSTIC 1352 switch (nxt) { 1353 case IPPROTO_DSTOPTS: 1354 case IPPROTO_ROUTING: 1355 case IPPROTO_HOPOPTS: 1356 case IPPROTO_AH: /* is it possible? */ 1357 break; 1358 default: 1359 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1360 } 1361 #endif 1362 1363 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1364 if (nxt == IPPROTO_AH) 1365 elen = (ip6e.ip6e_len + 2) << 2; 1366 else 1367 elen = (ip6e.ip6e_len + 1) << 3; 1368 1369 MGET(n, M_DONTWAIT, MT_DATA); 1370 if (n && elen >= MLEN) { 1371 MCLGET(n, M_DONTWAIT); 1372 if ((n->m_flags & M_EXT) == 0) { 1373 m_free(n); 1374 n = NULL; 1375 } 1376 } 1377 if (!n) 1378 return NULL; 1379 1380 n->m_len = 0; 1381 if (elen >= M_TRAILINGSPACE(n)) { 1382 m_free(n); 1383 return NULL; 1384 } 1385 1386 m_copydata(m, off, elen, mtod(n, caddr_t)); 1387 n->m_len = elen; 1388 return n; 1389 } 1390 #endif 1391 1392 /* 1393 * Get pointer to the previous header followed by the header 1394 * currently processed. 1395 * XXX: This function supposes that 1396 * M includes all headers, 1397 * the next header field and the header length field of each header 1398 * are valid, and 1399 * the sum of each header length equals to OFF. 1400 * Because of these assumptions, this function must be called very 1401 * carefully. Moreover, it will not be used in the near future when 1402 * we develop `neater' mechanism to process extension headers. 1403 */ 1404 char * 1405 ip6_get_prevhdr(m, off) 1406 struct mbuf *m; 1407 int off; 1408 { 1409 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1410 1411 if (off == sizeof(struct ip6_hdr)) 1412 return (&ip6->ip6_nxt); 1413 else { 1414 int len, nxt; 1415 struct ip6_ext *ip6e = NULL; 1416 1417 nxt = ip6->ip6_nxt; 1418 len = sizeof(struct ip6_hdr); 1419 while (len < off) { 1420 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1421 1422 switch (nxt) { 1423 case IPPROTO_FRAGMENT: 1424 len += sizeof(struct ip6_frag); 1425 break; 1426 case IPPROTO_AH: 1427 len += (ip6e->ip6e_len + 2) << 2; 1428 break; 1429 default: 1430 len += (ip6e->ip6e_len + 1) << 3; 1431 break; 1432 } 1433 nxt = ip6e->ip6e_nxt; 1434 } 1435 if (ip6e) 1436 return (&ip6e->ip6e_nxt); 1437 else 1438 return NULL; 1439 } 1440 } 1441 1442 /* 1443 * get next header offset. m will be retained. 1444 */ 1445 int 1446 ip6_nexthdr(m, off, proto, nxtp) 1447 struct mbuf *m; 1448 int off; 1449 int proto; 1450 int *nxtp; 1451 { 1452 struct ip6_hdr ip6; 1453 struct ip6_ext ip6e; 1454 struct ip6_frag fh; 1455 1456 /* just in case */ 1457 if (m == NULL) 1458 panic("ip6_nexthdr: m == NULL"); 1459 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1460 return -1; 1461 1462 switch (proto) { 1463 case IPPROTO_IPV6: 1464 if (m->m_pkthdr.len < off + sizeof(ip6)) 1465 return -1; 1466 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1467 if (nxtp) 1468 *nxtp = ip6.ip6_nxt; 1469 off += sizeof(ip6); 1470 return off; 1471 1472 case IPPROTO_FRAGMENT: 1473 /* 1474 * terminate parsing if it is not the first fragment, 1475 * it does not make sense to parse through it. 1476 */ 1477 if (m->m_pkthdr.len < off + sizeof(fh)) 1478 return -1; 1479 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1480 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1481 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1482 return -1; 1483 if (nxtp) 1484 *nxtp = fh.ip6f_nxt; 1485 off += sizeof(struct ip6_frag); 1486 return off; 1487 1488 case IPPROTO_AH: 1489 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1490 return -1; 1491 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1492 if (nxtp) 1493 *nxtp = ip6e.ip6e_nxt; 1494 off += (ip6e.ip6e_len + 2) << 2; 1495 return off; 1496 1497 case IPPROTO_HOPOPTS: 1498 case IPPROTO_ROUTING: 1499 case IPPROTO_DSTOPTS: 1500 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1501 return -1; 1502 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1503 if (nxtp) 1504 *nxtp = ip6e.ip6e_nxt; 1505 off += (ip6e.ip6e_len + 1) << 3; 1506 return off; 1507 1508 case IPPROTO_NONE: 1509 case IPPROTO_ESP: 1510 case IPPROTO_IPCOMP: 1511 /* give up */ 1512 return -1; 1513 1514 default: 1515 return -1; 1516 } 1517 1518 return -1; 1519 } 1520 1521 /* 1522 * get offset for the last header in the chain. m will be kept untainted. 1523 */ 1524 int 1525 ip6_lasthdr(m, off, proto, nxtp) 1526 struct mbuf *m; 1527 int off; 1528 int proto; 1529 int *nxtp; 1530 { 1531 int newoff; 1532 int nxt; 1533 1534 if (!nxtp) { 1535 nxt = -1; 1536 nxtp = &nxt; 1537 } 1538 while (1) { 1539 newoff = ip6_nexthdr(m, off, proto, nxtp); 1540 if (newoff < 0) 1541 return off; 1542 else if (newoff < off) 1543 return -1; /* invalid */ 1544 else if (newoff == off) 1545 return newoff; 1546 1547 off = newoff; 1548 proto = *nxtp; 1549 } 1550 } 1551 1552 struct ip6aux * 1553 ip6_addaux(m) 1554 struct mbuf *m; 1555 { 1556 struct m_tag *mtag; 1557 1558 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1559 if (!mtag) { 1560 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1561 M_NOWAIT); 1562 if (mtag) { 1563 m_tag_prepend(m, mtag); 1564 bzero(mtag + 1, sizeof(struct ip6aux)); 1565 } 1566 } 1567 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1568 } 1569 1570 struct ip6aux * 1571 ip6_findaux(m) 1572 struct mbuf *m; 1573 { 1574 struct m_tag *mtag; 1575 1576 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1577 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1578 } 1579 1580 void 1581 ip6_delaux(m) 1582 struct mbuf *m; 1583 { 1584 struct m_tag *mtag; 1585 1586 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1587 if (mtag) 1588 m_tag_delete(m, mtag); 1589 } 1590 1591 /* 1592 * System control for IP6 1593 */ 1594 1595 u_char inet6ctlerrmap[PRC_NCMDS] = { 1596 0, 0, 0, 0, 1597 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1598 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1599 EMSGSIZE, EHOSTUNREACH, 0, 0, 1600 0, 0, 0, 0, 1601 ENOPROTOOPT 1602 }; 1603