ip6_input.c revision 171167
13233Sksrini/* $FreeBSD: head/sys/netinet6/ip6_input.c 171167 2007-07-03 12:13:45Z gnn $ */ 23233Sksrini/* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 33233Sksrini 43233Sksrini/*- 53233Sksrini * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 63233Sksrini * All rights reserved. 73233Sksrini * 83233Sksrini * Redistribution and use in source and binary forms, with or without 93233Sksrini * modification, are permitted provided that the following conditions 103233Sksrini * are met: 113233Sksrini * 1. Redistributions of source code must retain the above copyright 123233Sksrini * notice, this list of conditions and the following disclaimer. 133233Sksrini * 2. Redistributions in binary form must reproduce the above copyright 143233Sksrini * notice, this list of conditions and the following disclaimer in the 153233Sksrini * documentation and/or other materials provided with the distribution. 163233Sksrini * 3. Neither the name of the project nor the names of its contributors 173233Sksrini * may be used to endorse or promote products derived from this software 183233Sksrini * without specific prior written permission. 193233Sksrini * 203233Sksrini * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 213233Sksrini * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 223233Sksrini * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 233233Sksrini * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 243233Sksrini * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 253233Sksrini * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 263233Sksrini * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 273233Sksrini * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 283233Sksrini * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 293233Sksrini * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 303233Sksrini * 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 <netipsec/ipsec.h> 106#include <netinet6/ip6_ipsec.h> 107#include <netipsec/ipsec6.h> 108#endif /* IPSEC */ 109 110#include <netinet6/ip6protosw.h> 111 112extern struct domain inet6domain; 113 114u_char ip6_protox[IPPROTO_MAX]; 115static struct ifqueue ip6intrq; 116static int ip6qmaxlen = IFQ_MAXLEN; 117struct in6_ifaddr *in6_ifaddr; 118 119extern struct callout in6_tmpaddrtimer_ch; 120 121int ip6_forward_srcrt; /* XXX */ 122int ip6_sourcecheck; /* XXX */ 123int ip6_sourcecheck_interval; /* XXX */ 124 125int ip6_ours_check_algorithm; 126 127struct pfil_head inet6_pfil_hook; 128 129struct ip6stat ip6stat; 130 131static void ip6_init2 __P((void *)); 132static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 133static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 134#ifdef PULLDOWN_TEST 135static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 136#endif 137 138/* 139 * IP6 initialization: fill in IP6 protocol switch table. 140 * All protocols not implemented in kernel go to raw IP6 protocol handler. 141 */ 142void 143ip6_init() 144{ 145 struct ip6protosw *pr; 146 int i; 147 148#ifdef DIAGNOSTIC 149 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 150 panic("sizeof(protosw) != sizeof(ip6protosw)"); 151#endif 152 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 153 if (pr == 0) 154 panic("ip6_init"); 155 156 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 157 for (i = 0; i < IPPROTO_MAX; i++) 158 ip6_protox[i] = pr - inet6sw; 159 /* 160 * Cycle through IP protocols and put them into the appropriate place 161 * in ip6_protox[]. 162 */ 163 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 164 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 165 if (pr->pr_domain->dom_family == PF_INET6 && 166 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 167 /* Be careful to only index valid IP protocols. */ 168 if (pr->pr_protocol < IPPROTO_MAX) 169 ip6_protox[pr->pr_protocol] = pr - inet6sw; 170 } 171 172 /* Initialize packet filter hooks. */ 173 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 174 inet6_pfil_hook.ph_af = AF_INET6; 175 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 176 printf("%s: WARNING: unable to register pfil hook, " 177 "error %d\n", __func__, i); 178 179 ip6intrq.ifq_maxlen = ip6qmaxlen; 180 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 181 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 182 scope6_init(); 183 addrsel_policy_init(); 184 nd6_init(); 185 frag6_init(); 186 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 187} 188 189static void 190ip6_init2(dummy) 191 void *dummy; 192{ 193 194 /* nd6_timer_init */ 195 callout_init(&nd6_timer_ch, 0); 196 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 197 198 /* timer for regeneranation of temporary addresses randomize ID */ 199 callout_init(&in6_tmpaddrtimer_ch, 0); 200 callout_reset(&in6_tmpaddrtimer_ch, 201 (ip6_temp_preferred_lifetime - ip6_desync_factor - 202 ip6_temp_regen_advance) * hz, 203 in6_tmpaddrtimer, NULL); 204} 205 206/* cheat */ 207/* This must be after route_init(), which is now SI_ORDER_THIRD */ 208SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 209 210extern struct route_in6 ip6_forward_rt; 211 212void 213ip6_input(m) 214 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 GIANT_REQUIRED; /* XXX for now */ 226 227#ifdef IPSEC 228 /* 229 * should the inner packet be considered authentic? 230 * see comment in ah4_input(). 231 * NB: m cannot be NULL when passed to the input routine 232 */ 233 234 m->m_flags &= ~M_AUTHIPHDR; 235 m->m_flags &= ~M_AUTHIPDGM; 236 237#endif /* IPSEC */ 238 239 /* 240 * make sure we don't have onion peering information into m_tag. 241 */ 242 ip6_delaux(m); 243 244 /* 245 * mbuf statistics 246 */ 247 if (m->m_flags & M_EXT) { 248 if (m->m_next) 249 ip6stat.ip6s_mext2m++; 250 else 251 ip6stat.ip6s_mext1++; 252 } else { 253#define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 254 if (m->m_next) { 255 if (m->m_flags & M_LOOP) { 256 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 257 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 258 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 259 else 260 ip6stat.ip6s_m2m[0]++; 261 } else 262 ip6stat.ip6s_m1++; 263#undef M2MMAX 264 } 265 266 /* drop the packet if IPv6 operation is disabled on the IF */ 267 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 268 m_freem(m); 269 return; 270 } 271 272 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 273 ip6stat.ip6s_total++; 274 275#ifndef PULLDOWN_TEST 276 /* 277 * L2 bridge code and some other code can return mbuf chain 278 * that does not conform to KAME requirement. too bad. 279 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 280 */ 281 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 282 struct mbuf *n; 283 284 MGETHDR(n, M_DONTWAIT, MT_HEADER); 285 if (n) 286 M_MOVE_PKTHDR(n, m); 287 if (n && n->m_pkthdr.len > MHLEN) { 288 MCLGET(n, M_DONTWAIT); 289 if ((n->m_flags & M_EXT) == 0) { 290 m_freem(n); 291 n = NULL; 292 } 293 } 294 if (n == NULL) { 295 m_freem(m); 296 return; /* ENOBUFS */ 297 } 298 299 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 300 n->m_len = n->m_pkthdr.len; 301 m_freem(m); 302 m = n; 303 } 304 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 305#endif 306 307 if (m->m_len < sizeof(struct ip6_hdr)) { 308 struct ifnet *inifp; 309 inifp = m->m_pkthdr.rcvif; 310 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 311 ip6stat.ip6s_toosmall++; 312 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 313 return; 314 } 315 } 316 317 ip6 = mtod(m, struct ip6_hdr *); 318 319 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 320 ip6stat.ip6s_badvers++; 321 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 322 goto bad; 323 } 324 325 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 326 327 /* 328 * Check against address spoofing/corruption. 329 */ 330 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 331 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 332 /* 333 * XXX: "badscope" is not very suitable for a multicast source. 334 */ 335 ip6stat.ip6s_badscope++; 336 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 337 goto bad; 338 } 339 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 340 !(m->m_flags & M_LOOP)) { 341 /* 342 * In this case, the packet should come from the loopback 343 * interface. However, we cannot just check the if_flags, 344 * because ip6_mloopback() passes the "actual" interface 345 * as the outgoing/incoming interface. 346 */ 347 ip6stat.ip6s_badscope++; 348 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 349 goto bad; 350 } 351 352#ifdef ALTQ 353 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 354 /* packet is dropped by traffic conditioner */ 355 return; 356 } 357#endif 358 /* 359 * The following check is not documented in specs. A malicious 360 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 361 * and bypass security checks (act as if it was from 127.0.0.1 by using 362 * IPv6 src ::ffff:127.0.0.1). Be cautious. 363 * 364 * This check chokes if we are in an SIIT cloud. As none of BSDs 365 * support IPv4-less kernel compilation, we cannot support SIIT 366 * environment at all. So, it makes more sense for us to reject any 367 * malicious packets for non-SIIT environment, than try to do a 368 * partial support for SIIT environment. 369 */ 370 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 371 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 372 ip6stat.ip6s_badscope++; 373 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 374 goto bad; 375 } 376#if 0 377 /* 378 * Reject packets with IPv4 compatible addresses (auto tunnel). 379 * 380 * The code forbids auto tunnel relay case in RFC1933 (the check is 381 * stronger than RFC1933). We may want to re-enable it if mech-xx 382 * is revised to forbid relaying case. 383 */ 384 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 385 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 386 ip6stat.ip6s_badscope++; 387 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 388 goto bad; 389 } 390#endif 391 392 /* 393 * Run through list of hooks for input packets. 394 * 395 * NB: Beware of the destination address changing 396 * (e.g. by NAT rewriting). When this happens, 397 * tell ip6_forward to do the right thing. 398 */ 399 odst = ip6->ip6_dst; 400 401 /* Jump over all PFIL processing if hooks are not active. */ 402 if (!PFIL_HOOKED(&inet6_pfil_hook)) 403 goto passin; 404 405 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 406 return; 407 if (m == NULL) /* consumed by filter */ 408 return; 409 ip6 = mtod(m, struct ip6_hdr *); 410 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 411 412passin: 413 /* 414 * Disambiguate address scope zones (if there is ambiguity). 415 * We first make sure that the original source or destination address 416 * is not in our internal form for scoped addresses. Such addresses 417 * are not necessarily invalid spec-wise, but we cannot accept them due 418 * to the usage conflict. 419 * in6_setscope() then also checks and rejects the cases where src or 420 * dst are the loopback address and the receiving interface 421 * is not loopback. 422 */ 423 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 424 ip6stat.ip6s_badscope++; /* XXX */ 425 goto bad; 426 } 427 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 428 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 429 ip6stat.ip6s_badscope++; 430 goto bad; 431 } 432 433 /* 434 * Multicast check 435 */ 436 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 437 struct in6_multi *in6m = 0; 438 439 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 440 /* 441 * See if we belong to the destination multicast group on the 442 * arrival interface. 443 */ 444 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 445 if (in6m) 446 ours = 1; 447 else if (!ip6_mrouter) { 448 ip6stat.ip6s_notmember++; 449 ip6stat.ip6s_cantforward++; 450 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 451 goto bad; 452 } 453 deliverifp = m->m_pkthdr.rcvif; 454 goto hbhcheck; 455 } 456 457 /* 458 * Unicast check 459 */ 460 if (ip6_forward_rt.ro_rt != NULL && 461 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 462 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 463 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 464 ip6stat.ip6s_forward_cachehit++; 465 else { 466 struct sockaddr_in6 *dst6; 467 468 if (ip6_forward_rt.ro_rt) { 469 /* route is down or destination is different */ 470 ip6stat.ip6s_forward_cachemiss++; 471 RTFREE(ip6_forward_rt.ro_rt); 472 ip6_forward_rt.ro_rt = 0; 473 } 474 475 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 476 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 477 dst6->sin6_len = sizeof(struct sockaddr_in6); 478 dst6->sin6_family = AF_INET6; 479 dst6->sin6_addr = ip6->ip6_dst; 480 481 rtalloc((struct route *)&ip6_forward_rt); 482 } 483 484#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 485 486 /* 487 * Accept the packet if the forwarding interface to the destination 488 * according to the routing table is the loopback interface, 489 * unless the associated route has a gateway. 490 * Note that this approach causes to accept a packet if there is a 491 * route to the loopback interface for the destination of the packet. 492 * But we think it's even useful in some situations, e.g. when using 493 * a special daemon which wants to intercept the packet. 494 * 495 * XXX: some OSes automatically make a cloned route for the destination 496 * of an outgoing packet. If the outgoing interface of the packet 497 * is a loopback one, the kernel would consider the packet to be 498 * accepted, even if we have no such address assinged on the interface. 499 * We check the cloned flag of the route entry to reject such cases, 500 * assuming that route entries for our own addresses are not made by 501 * cloning (it should be true because in6_addloop explicitly installs 502 * the host route). However, we might have to do an explicit check 503 * while it would be less efficient. Or, should we rather install a 504 * reject route for such a case? 505 */ 506 if (ip6_forward_rt.ro_rt && 507 (ip6_forward_rt.ro_rt->rt_flags & 508 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 509#ifdef RTF_WASCLONED 510 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 511#endif 512#ifdef RTF_CLONED 513 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 514#endif 515#if 0 516 /* 517 * The check below is redundant since the comparison of 518 * the destination and the key of the rtentry has 519 * already done through looking up the routing table. 520 */ 521 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 522 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 523#endif 524 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 525 struct in6_ifaddr *ia6 = 526 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 527 528 /* 529 * record address information into m_tag. 530 */ 531 (void)ip6_setdstifaddr(m, ia6); 532 533 /* 534 * packets to a tentative, duplicated, or somehow invalid 535 * address must not be accepted. 536 */ 537 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 538 /* this address is ready */ 539 ours = 1; 540 deliverifp = ia6->ia_ifp; /* correct? */ 541 /* Count the packet in the ip address stats */ 542 ia6->ia_ifa.if_ipackets++; 543 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 544 goto hbhcheck; 545 } else { 546 char ip6bufs[INET6_ADDRSTRLEN]; 547 char ip6bufd[INET6_ADDRSTRLEN]; 548 /* address is not ready, so discard the packet. */ 549 nd6log((LOG_INFO, 550 "ip6_input: packet to an unready address %s->%s\n", 551 ip6_sprintf(ip6bufs, &ip6->ip6_src), 552 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 553 554 goto bad; 555 } 556 } 557 558 /* 559 * FAITH (Firewall Aided Internet Translator) 560 */ 561 if (ip6_keepfaith) { 562 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 563 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 564 /* XXX do we need more sanity checks? */ 565 ours = 1; 566 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 567 goto hbhcheck; 568 } 569 } 570 571 /* 572 * Now there is no reason to process the packet if it's not our own 573 * and we're not a router. 574 */ 575 if (!ip6_forwarding) { 576 ip6stat.ip6s_cantforward++; 577 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 578 goto bad; 579 } 580 581 hbhcheck: 582 /* 583 * record address information into m_tag, if we don't have one yet. 584 * note that we are unable to record it, if the address is not listed 585 * as our interface address (e.g. multicast addresses, addresses 586 * within FAITH prefixes and such). 587 */ 588 if (deliverifp && !ip6_getdstifaddr(m)) { 589 struct in6_ifaddr *ia6; 590 591 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 592 if (ia6) { 593 if (!ip6_setdstifaddr(m, ia6)) { 594 /* 595 * XXX maybe we should drop the packet here, 596 * as we could not provide enough information 597 * to the upper layers. 598 */ 599 } 600 } 601 } 602 603 /* 604 * Process Hop-by-Hop options header if it's contained. 605 * m may be modified in ip6_hopopts_input(). 606 * If a JumboPayload option is included, plen will also be modified. 607 */ 608 plen = (u_int32_t)ntohs(ip6->ip6_plen); 609 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 610 struct ip6_hbh *hbh; 611 612 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 613#if 0 /*touches NULL pointer*/ 614 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 615#endif 616 return; /* m have already been freed */ 617 } 618 619 /* adjust pointer */ 620 ip6 = mtod(m, struct ip6_hdr *); 621 622 /* 623 * if the payload length field is 0 and the next header field 624 * indicates Hop-by-Hop Options header, then a Jumbo Payload 625 * option MUST be included. 626 */ 627 if (ip6->ip6_plen == 0 && plen == 0) { 628 /* 629 * Note that if a valid jumbo payload option is 630 * contained, ip6_hopopts_input() must set a valid 631 * (non-zero) payload length to the variable plen. 632 */ 633 ip6stat.ip6s_badoptions++; 634 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 635 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 636 icmp6_error(m, ICMP6_PARAM_PROB, 637 ICMP6_PARAMPROB_HEADER, 638 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 639 return; 640 } 641#ifndef PULLDOWN_TEST 642 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 643 hbh = (struct ip6_hbh *)(ip6 + 1); 644#else 645 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 646 sizeof(struct ip6_hbh)); 647 if (hbh == NULL) { 648 ip6stat.ip6s_tooshort++; 649 return; 650 } 651#endif 652 nxt = hbh->ip6h_nxt; 653 654 /* 655 * If we are acting as a router and the packet contains a 656 * router alert option, see if we know the option value. 657 * Currently, we only support the option value for MLD, in which 658 * case we should pass the packet to the multicast routing 659 * daemon. 660 */ 661 if (rtalert != ~0 && ip6_forwarding) { 662 switch (rtalert) { 663 case IP6OPT_RTALERT_MLD: 664 ours = 1; 665 break; 666 default: 667 /* 668 * RFC2711 requires unrecognized values must be 669 * silently ignored. 670 */ 671 break; 672 } 673 } 674 } else 675 nxt = ip6->ip6_nxt; 676 677 /* 678 * Check that the amount of data in the buffers 679 * is as at least much as the IPv6 header would have us expect. 680 * Trim mbufs if longer than we expect. 681 * Drop packet if shorter than we expect. 682 */ 683 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 684 ip6stat.ip6s_tooshort++; 685 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 686 goto bad; 687 } 688 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 689 if (m->m_len == m->m_pkthdr.len) { 690 m->m_len = sizeof(struct ip6_hdr) + plen; 691 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 692 } else 693 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 694 } 695 696 /* 697 * Forward if desirable. 698 */ 699 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 700 /* 701 * If we are acting as a multicast router, all 702 * incoming multicast packets are passed to the 703 * kernel-level multicast forwarding function. 704 * The packet is returned (relatively) intact; if 705 * ip6_mforward() returns a non-zero value, the packet 706 * must be discarded, else it may be accepted below. 707 */ 708 if (ip6_mrouter && ip6_mforward && 709 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 710 ip6stat.ip6s_cantforward++; 711 m_freem(m); 712 return; 713 } 714 if (!ours) { 715 m_freem(m); 716 return; 717 } 718 } else if (!ours) { 719 ip6_forward(m, srcrt); 720 return; 721 } 722 723 ip6 = mtod(m, struct ip6_hdr *); 724 725 /* 726 * Malicious party may be able to use IPv4 mapped addr to confuse 727 * tcp/udp stack and bypass security checks (act as if it was from 728 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 729 * 730 * For SIIT end node behavior, you may want to disable the check. 731 * However, you will become vulnerable to attacks using IPv4 mapped 732 * source. 733 */ 734 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 735 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 736 ip6stat.ip6s_badscope++; 737 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 738 goto bad; 739 } 740 741 /* 742 * Tell launch routine the next header 743 */ 744 ip6stat.ip6s_delivered++; 745 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 746 nest = 0; 747 748 while (nxt != IPPROTO_DONE) { 749 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 750 ip6stat.ip6s_toomanyhdr++; 751 goto bad; 752 } 753 754 /* 755 * protection against faulty packet - there should be 756 * more sanity checks in header chain processing. 757 */ 758 if (m->m_pkthdr.len < off) { 759 ip6stat.ip6s_tooshort++; 760 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 761 goto bad; 762 } 763 764#ifdef IPSEC 765 /* 766 * enforce IPsec policy checking if we are seeing last header. 767 * note that we do not visit this with protocols with pcb layer 768 * code - like udp/tcp/raw ip. 769 */ 770 if (ip6_ipsec_input(m, nxt)) 771 goto bad; 772#endif /* IPSEC */ 773 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 774 } 775 return; 776 bad: 777 m_freem(m); 778} 779 780/* 781 * set/grab in6_ifaddr correspond to IPv6 destination address. 782 * XXX backward compatibility wrapper 783 */ 784static struct ip6aux * 785ip6_setdstifaddr(m, ia6) 786 struct mbuf *m; 787 struct in6_ifaddr *ia6; 788{ 789 struct ip6aux *ip6a; 790 791 ip6a = ip6_addaux(m); 792 if (ip6a) 793 ip6a->ip6a_dstia6 = ia6; 794 return ip6a; /* NULL if failed to set */ 795} 796 797struct in6_ifaddr * 798ip6_getdstifaddr(m) 799 struct mbuf *m; 800{ 801 struct ip6aux *ip6a; 802 803 ip6a = ip6_findaux(m); 804 if (ip6a) 805 return ip6a->ip6a_dstia6; 806 else 807 return NULL; 808} 809 810/* 811 * Hop-by-Hop options header processing. If a valid jumbo payload option is 812 * included, the real payload length will be stored in plenp. 813 */ 814static int 815ip6_hopopts_input(plenp, rtalertp, mp, offp) 816 u_int32_t *plenp; 817 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 818 struct mbuf **mp; 819 int *offp; 820{ 821 struct mbuf *m = *mp; 822 int off = *offp, hbhlen; 823 struct ip6_hbh *hbh; 824 u_int8_t *opt; 825 826 /* validation of the length of the header */ 827#ifndef PULLDOWN_TEST 828 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 829 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 830 hbhlen = (hbh->ip6h_len + 1) << 3; 831 832 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 833 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 834#else 835 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 836 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 837 if (hbh == NULL) { 838 ip6stat.ip6s_tooshort++; 839 return -1; 840 } 841 hbhlen = (hbh->ip6h_len + 1) << 3; 842 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 843 hbhlen); 844 if (hbh == NULL) { 845 ip6stat.ip6s_tooshort++; 846 return -1; 847 } 848#endif 849 off += hbhlen; 850 hbhlen -= sizeof(struct ip6_hbh); 851 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 852 853 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 854 hbhlen, rtalertp, plenp) < 0) 855 return (-1); 856 857 *offp = off; 858 *mp = m; 859 return (0); 860} 861 862/* 863 * Search header for all Hop-by-hop options and process each option. 864 * This function is separate from ip6_hopopts_input() in order to 865 * handle a case where the sending node itself process its hop-by-hop 866 * options header. In such a case, the function is called from ip6_output(). 867 * 868 * The function assumes that hbh header is located right after the IPv6 header 869 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 870 * opthead + hbhlen is located in continuous memory region. 871 */ 872int 873ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 874 struct mbuf *m; 875 u_int8_t *opthead; 876 int hbhlen; 877 u_int32_t *rtalertp; 878 u_int32_t *plenp; 879{ 880 struct ip6_hdr *ip6; 881 int optlen = 0; 882 u_int8_t *opt = opthead; 883 u_int16_t rtalert_val; 884 u_int32_t jumboplen; 885 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 886 887 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 888 switch (*opt) { 889 case IP6OPT_PAD1: 890 optlen = 1; 891 break; 892 case IP6OPT_PADN: 893 if (hbhlen < IP6OPT_MINLEN) { 894 ip6stat.ip6s_toosmall++; 895 goto bad; 896 } 897 optlen = *(opt + 1) + 2; 898 break; 899 case IP6OPT_ROUTER_ALERT: 900 /* XXX may need check for alignment */ 901 if (hbhlen < IP6OPT_RTALERT_LEN) { 902 ip6stat.ip6s_toosmall++; 903 goto bad; 904 } 905 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 906 /* XXX stat */ 907 icmp6_error(m, ICMP6_PARAM_PROB, 908 ICMP6_PARAMPROB_HEADER, 909 erroff + opt + 1 - opthead); 910 return (-1); 911 } 912 optlen = IP6OPT_RTALERT_LEN; 913 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 914 *rtalertp = ntohs(rtalert_val); 915 break; 916 case IP6OPT_JUMBO: 917 /* XXX may need check for alignment */ 918 if (hbhlen < IP6OPT_JUMBO_LEN) { 919 ip6stat.ip6s_toosmall++; 920 goto bad; 921 } 922 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 923 /* XXX stat */ 924 icmp6_error(m, ICMP6_PARAM_PROB, 925 ICMP6_PARAMPROB_HEADER, 926 erroff + opt + 1 - opthead); 927 return (-1); 928 } 929 optlen = IP6OPT_JUMBO_LEN; 930 931 /* 932 * IPv6 packets that have non 0 payload length 933 * must not contain a jumbo payload option. 934 */ 935 ip6 = mtod(m, struct ip6_hdr *); 936 if (ip6->ip6_plen) { 937 ip6stat.ip6s_badoptions++; 938 icmp6_error(m, ICMP6_PARAM_PROB, 939 ICMP6_PARAMPROB_HEADER, 940 erroff + opt - opthead); 941 return (-1); 942 } 943 944 /* 945 * We may see jumbolen in unaligned location, so 946 * we'd need to perform bcopy(). 947 */ 948 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 949 jumboplen = (u_int32_t)htonl(jumboplen); 950 951#if 1 952 /* 953 * if there are multiple jumbo payload options, 954 * *plenp will be non-zero and the packet will be 955 * rejected. 956 * the behavior may need some debate in ipngwg - 957 * multiple options does not make sense, however, 958 * there's no explicit mention in specification. 959 */ 960 if (*plenp != 0) { 961 ip6stat.ip6s_badoptions++; 962 icmp6_error(m, ICMP6_PARAM_PROB, 963 ICMP6_PARAMPROB_HEADER, 964 erroff + opt + 2 - opthead); 965 return (-1); 966 } 967#endif 968 969 /* 970 * jumbo payload length must be larger than 65535. 971 */ 972 if (jumboplen <= IPV6_MAXPACKET) { 973 ip6stat.ip6s_badoptions++; 974 icmp6_error(m, ICMP6_PARAM_PROB, 975 ICMP6_PARAMPROB_HEADER, 976 erroff + opt + 2 - opthead); 977 return (-1); 978 } 979 *plenp = jumboplen; 980 981 break; 982 default: /* unknown option */ 983 if (hbhlen < IP6OPT_MINLEN) { 984 ip6stat.ip6s_toosmall++; 985 goto bad; 986 } 987 optlen = ip6_unknown_opt(opt, m, 988 erroff + opt - opthead); 989 if (optlen == -1) 990 return (-1); 991 optlen += 2; 992 break; 993 } 994 } 995 996 return (0); 997 998 bad: 999 m_freem(m); 1000 return (-1); 1001} 1002 1003/* 1004 * Unknown option processing. 1005 * The third argument `off' is the offset from the IPv6 header to the option, 1006 * which is necessary if the IPv6 header the and option header and IPv6 header 1007 * is not continuous in order to return an ICMPv6 error. 1008 */ 1009int 1010ip6_unknown_opt(optp, m, off) 1011 u_int8_t *optp; 1012 struct mbuf *m; 1013 int off; 1014{ 1015 struct ip6_hdr *ip6; 1016 1017 switch (IP6OPT_TYPE(*optp)) { 1018 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1019 return ((int)*(optp + 1)); 1020 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1021 m_freem(m); 1022 return (-1); 1023 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1024 ip6stat.ip6s_badoptions++; 1025 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1026 return (-1); 1027 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1028 ip6stat.ip6s_badoptions++; 1029 ip6 = mtod(m, struct ip6_hdr *); 1030 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1031 (m->m_flags & (M_BCAST|M_MCAST))) 1032 m_freem(m); 1033 else 1034 icmp6_error(m, ICMP6_PARAM_PROB, 1035 ICMP6_PARAMPROB_OPTION, off); 1036 return (-1); 1037 } 1038 1039 m_freem(m); /* XXX: NOTREACHED */ 1040 return (-1); 1041} 1042 1043/* 1044 * Create the "control" list for this pcb. 1045 * The function will not modify mbuf chain at all. 1046 * 1047 * with KAME mbuf chain restriction: 1048 * The routine will be called from upper layer handlers like tcp6_input(). 1049 * Thus the routine assumes that the caller (tcp6_input) have already 1050 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1051 * very first mbuf on the mbuf chain. 1052 */ 1053void 1054ip6_savecontrol(in6p, m, mp) 1055 struct inpcb *in6p; 1056 struct mbuf *m, **mp; 1057{ 1058#define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1059 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1060 1061#ifdef SO_TIMESTAMP 1062 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1063 struct timeval tv; 1064 1065 microtime(&tv); 1066 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1067 SCM_TIMESTAMP, SOL_SOCKET); 1068 if (*mp) 1069 mp = &(*mp)->m_next; 1070 } 1071#endif 1072 1073 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1074 return; 1075 1076 /* RFC 2292 sec. 5 */ 1077 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1078 struct in6_pktinfo pi6; 1079 1080 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1081 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1082 pi6.ipi6_ifindex = 1083 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1084 1085 *mp = sbcreatecontrol((caddr_t) &pi6, 1086 sizeof(struct in6_pktinfo), 1087 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1088 if (*mp) 1089 mp = &(*mp)->m_next; 1090 } 1091 1092 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1093 int hlim = ip6->ip6_hlim & 0xff; 1094 1095 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1096 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1097 if (*mp) 1098 mp = &(*mp)->m_next; 1099 } 1100 1101 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1102 u_int32_t flowinfo; 1103 int tclass; 1104 1105 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1106 flowinfo >>= 20; 1107 1108 tclass = flowinfo & 0xff; 1109 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1110 IPV6_TCLASS, IPPROTO_IPV6); 1111 if (*mp) 1112 mp = &(*mp)->m_next; 1113 } 1114 1115 /* 1116 * IPV6_HOPOPTS socket option. Recall that we required super-user 1117 * privilege for the option (see ip6_ctloutput), but it might be too 1118 * strict, since there might be some hop-by-hop options which can be 1119 * returned to normal user. 1120 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1121 */ 1122 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1123 /* 1124 * Check if a hop-by-hop options header is contatined in the 1125 * received packet, and if so, store the options as ancillary 1126 * data. Note that a hop-by-hop options header must be 1127 * just after the IPv6 header, which is assured through the 1128 * IPv6 input processing. 1129 */ 1130 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1131 struct ip6_hbh *hbh; 1132 int hbhlen = 0; 1133#ifdef PULLDOWN_TEST 1134 struct mbuf *ext; 1135#endif 1136 1137#ifndef PULLDOWN_TEST 1138 hbh = (struct ip6_hbh *)(ip6 + 1); 1139 hbhlen = (hbh->ip6h_len + 1) << 3; 1140#else 1141 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1142 ip6->ip6_nxt); 1143 if (ext == NULL) { 1144 ip6stat.ip6s_tooshort++; 1145 return; 1146 } 1147 hbh = mtod(ext, struct ip6_hbh *); 1148 hbhlen = (hbh->ip6h_len + 1) << 3; 1149 if (hbhlen != ext->m_len) { 1150 m_freem(ext); 1151 ip6stat.ip6s_tooshort++; 1152 return; 1153 } 1154#endif 1155 1156 /* 1157 * XXX: We copy the whole header even if a 1158 * jumbo payload option is included, the option which 1159 * is to be removed before returning according to 1160 * RFC2292. 1161 * Note: this constraint is removed in RFC3542 1162 */ 1163 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1164 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1165 IPPROTO_IPV6); 1166 if (*mp) 1167 mp = &(*mp)->m_next; 1168#ifdef PULLDOWN_TEST 1169 m_freem(ext); 1170#endif 1171 } 1172 } 1173 1174 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1175 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1176 1177 /* 1178 * Search for destination options headers or routing 1179 * header(s) through the header chain, and stores each 1180 * header as ancillary data. 1181 * Note that the order of the headers remains in 1182 * the chain of ancillary data. 1183 */ 1184 while (1) { /* is explicit loop prevention necessary? */ 1185 struct ip6_ext *ip6e = NULL; 1186 int elen; 1187#ifdef PULLDOWN_TEST 1188 struct mbuf *ext = NULL; 1189#endif 1190 1191 /* 1192 * if it is not an extension header, don't try to 1193 * pull it from the chain. 1194 */ 1195 switch (nxt) { 1196 case IPPROTO_DSTOPTS: 1197 case IPPROTO_ROUTING: 1198 case IPPROTO_HOPOPTS: 1199 case IPPROTO_AH: /* is it possible? */ 1200 break; 1201 default: 1202 goto loopend; 1203 } 1204 1205#ifndef PULLDOWN_TEST 1206 if (off + sizeof(*ip6e) > m->m_len) 1207 goto loopend; 1208 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1209 if (nxt == IPPROTO_AH) 1210 elen = (ip6e->ip6e_len + 2) << 2; 1211 else 1212 elen = (ip6e->ip6e_len + 1) << 3; 1213 if (off + elen > m->m_len) 1214 goto loopend; 1215#else 1216 ext = ip6_pullexthdr(m, off, nxt); 1217 if (ext == NULL) { 1218 ip6stat.ip6s_tooshort++; 1219 return; 1220 } 1221 ip6e = mtod(ext, struct ip6_ext *); 1222 if (nxt == IPPROTO_AH) 1223 elen = (ip6e->ip6e_len + 2) << 2; 1224 else 1225 elen = (ip6e->ip6e_len + 1) << 3; 1226 if (elen != ext->m_len) { 1227 m_freem(ext); 1228 ip6stat.ip6s_tooshort++; 1229 return; 1230 } 1231#endif 1232 1233 switch (nxt) { 1234 case IPPROTO_DSTOPTS: 1235 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1236 break; 1237 1238 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1239 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1240 IPPROTO_IPV6); 1241 if (*mp) 1242 mp = &(*mp)->m_next; 1243 break; 1244 case IPPROTO_ROUTING: 1245 if (!in6p->in6p_flags & IN6P_RTHDR) 1246 break; 1247 1248 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1249 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1250 IPPROTO_IPV6); 1251 if (*mp) 1252 mp = &(*mp)->m_next; 1253 break; 1254 case IPPROTO_HOPOPTS: 1255 case IPPROTO_AH: /* is it possible? */ 1256 break; 1257 1258 default: 1259 /* 1260 * other cases have been filtered in the above. 1261 * none will visit this case. here we supply 1262 * the code just in case (nxt overwritten or 1263 * other cases). 1264 */ 1265#ifdef PULLDOWN_TEST 1266 m_freem(ext); 1267#endif 1268 goto loopend; 1269 1270 } 1271 1272 /* proceed with the next header. */ 1273 off += elen; 1274 nxt = ip6e->ip6e_nxt; 1275 ip6e = NULL; 1276#ifdef PULLDOWN_TEST 1277 m_freem(ext); 1278 ext = NULL; 1279#endif 1280 } 1281 loopend: 1282 ; 1283 } 1284 1285#undef IS2292 1286} 1287 1288void 1289ip6_notify_pmtu(in6p, dst, mtu) 1290 struct inpcb *in6p; 1291 struct sockaddr_in6 *dst; 1292 u_int32_t *mtu; 1293{ 1294 struct socket *so; 1295 struct mbuf *m_mtu; 1296 struct ip6_mtuinfo mtuctl; 1297 1298 so = in6p->inp_socket; 1299 1300 if (mtu == NULL) 1301 return; 1302 1303#ifdef DIAGNOSTIC 1304 if (so == NULL) /* I believe this is impossible */ 1305 panic("ip6_notify_pmtu: socket is NULL"); 1306#endif 1307 1308 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1309 mtuctl.ip6m_mtu = *mtu; 1310 mtuctl.ip6m_addr = *dst; 1311 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1312 return; 1313 1314 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1315 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1316 return; 1317 1318 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1319 == 0) { 1320 m_freem(m_mtu); 1321 /* XXX: should count statistics */ 1322 } else 1323 sorwakeup(so); 1324 1325 return; 1326} 1327 1328#ifdef PULLDOWN_TEST 1329/* 1330 * pull single extension header from mbuf chain. returns single mbuf that 1331 * contains the result, or NULL on error. 1332 */ 1333static struct mbuf * 1334ip6_pullexthdr(m, off, nxt) 1335 struct mbuf *m; 1336 size_t off; 1337 int nxt; 1338{ 1339 struct ip6_ext ip6e; 1340 size_t elen; 1341 struct mbuf *n; 1342 1343#ifdef DIAGNOSTIC 1344 switch (nxt) { 1345 case IPPROTO_DSTOPTS: 1346 case IPPROTO_ROUTING: 1347 case IPPROTO_HOPOPTS: 1348 case IPPROTO_AH: /* is it possible? */ 1349 break; 1350 default: 1351 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1352 } 1353#endif 1354 1355 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1356 if (nxt == IPPROTO_AH) 1357 elen = (ip6e.ip6e_len + 2) << 2; 1358 else 1359 elen = (ip6e.ip6e_len + 1) << 3; 1360 1361 MGET(n, M_DONTWAIT, MT_DATA); 1362 if (n && elen >= MLEN) { 1363 MCLGET(n, M_DONTWAIT); 1364 if ((n->m_flags & M_EXT) == 0) { 1365 m_free(n); 1366 n = NULL; 1367 } 1368 } 1369 if (!n) 1370 return NULL; 1371 1372 n->m_len = 0; 1373 if (elen >= M_TRAILINGSPACE(n)) { 1374 m_free(n); 1375 return NULL; 1376 } 1377 1378 m_copydata(m, off, elen, mtod(n, caddr_t)); 1379 n->m_len = elen; 1380 return n; 1381} 1382#endif 1383 1384/* 1385 * Get pointer to the previous header followed by the header 1386 * currently processed. 1387 * XXX: This function supposes that 1388 * M includes all headers, 1389 * the next header field and the header length field of each header 1390 * are valid, and 1391 * the sum of each header length equals to OFF. 1392 * Because of these assumptions, this function must be called very 1393 * carefully. Moreover, it will not be used in the near future when 1394 * we develop `neater' mechanism to process extension headers. 1395 */ 1396char * 1397ip6_get_prevhdr(m, off) 1398 struct mbuf *m; 1399 int off; 1400{ 1401 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1402 1403 if (off == sizeof(struct ip6_hdr)) 1404 return (&ip6->ip6_nxt); 1405 else { 1406 int len, nxt; 1407 struct ip6_ext *ip6e = NULL; 1408 1409 nxt = ip6->ip6_nxt; 1410 len = sizeof(struct ip6_hdr); 1411 while (len < off) { 1412 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1413 1414 switch (nxt) { 1415 case IPPROTO_FRAGMENT: 1416 len += sizeof(struct ip6_frag); 1417 break; 1418 case IPPROTO_AH: 1419 len += (ip6e->ip6e_len + 2) << 2; 1420 break; 1421 default: 1422 len += (ip6e->ip6e_len + 1) << 3; 1423 break; 1424 } 1425 nxt = ip6e->ip6e_nxt; 1426 } 1427 if (ip6e) 1428 return (&ip6e->ip6e_nxt); 1429 else 1430 return NULL; 1431 } 1432} 1433 1434/* 1435 * get next header offset. m will be retained. 1436 */ 1437int 1438ip6_nexthdr(m, off, proto, nxtp) 1439 struct mbuf *m; 1440 int off; 1441 int proto; 1442 int *nxtp; 1443{ 1444 struct ip6_hdr ip6; 1445 struct ip6_ext ip6e; 1446 struct ip6_frag fh; 1447 1448 /* just in case */ 1449 if (m == NULL) 1450 panic("ip6_nexthdr: m == NULL"); 1451 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1452 return -1; 1453 1454 switch (proto) { 1455 case IPPROTO_IPV6: 1456 if (m->m_pkthdr.len < off + sizeof(ip6)) 1457 return -1; 1458 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1459 if (nxtp) 1460 *nxtp = ip6.ip6_nxt; 1461 off += sizeof(ip6); 1462 return off; 1463 1464 case IPPROTO_FRAGMENT: 1465 /* 1466 * terminate parsing if it is not the first fragment, 1467 * it does not make sense to parse through it. 1468 */ 1469 if (m->m_pkthdr.len < off + sizeof(fh)) 1470 return -1; 1471 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1472 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1473 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1474 return -1; 1475 if (nxtp) 1476 *nxtp = fh.ip6f_nxt; 1477 off += sizeof(struct ip6_frag); 1478 return off; 1479 1480 case IPPROTO_AH: 1481 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1482 return -1; 1483 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1484 if (nxtp) 1485 *nxtp = ip6e.ip6e_nxt; 1486 off += (ip6e.ip6e_len + 2) << 2; 1487 return off; 1488 1489 case IPPROTO_HOPOPTS: 1490 case IPPROTO_ROUTING: 1491 case IPPROTO_DSTOPTS: 1492 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1493 return -1; 1494 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1495 if (nxtp) 1496 *nxtp = ip6e.ip6e_nxt; 1497 off += (ip6e.ip6e_len + 1) << 3; 1498 return off; 1499 1500 case IPPROTO_NONE: 1501 case IPPROTO_ESP: 1502 case IPPROTO_IPCOMP: 1503 /* give up */ 1504 return -1; 1505 1506 default: 1507 return -1; 1508 } 1509 1510 return -1; 1511} 1512 1513/* 1514 * get offset for the last header in the chain. m will be kept untainted. 1515 */ 1516int 1517ip6_lasthdr(m, off, proto, nxtp) 1518 struct mbuf *m; 1519 int off; 1520 int proto; 1521 int *nxtp; 1522{ 1523 int newoff; 1524 int nxt; 1525 1526 if (!nxtp) { 1527 nxt = -1; 1528 nxtp = &nxt; 1529 } 1530 while (1) { 1531 newoff = ip6_nexthdr(m, off, proto, nxtp); 1532 if (newoff < 0) 1533 return off; 1534 else if (newoff < off) 1535 return -1; /* invalid */ 1536 else if (newoff == off) 1537 return newoff; 1538 1539 off = newoff; 1540 proto = *nxtp; 1541 } 1542} 1543 1544struct ip6aux * 1545ip6_addaux(m) 1546 struct mbuf *m; 1547{ 1548 struct m_tag *mtag; 1549 1550 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1551 if (!mtag) { 1552 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1553 M_NOWAIT); 1554 if (mtag) { 1555 m_tag_prepend(m, mtag); 1556 bzero(mtag + 1, sizeof(struct ip6aux)); 1557 } 1558 } 1559 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1560} 1561 1562struct ip6aux * 1563ip6_findaux(m) 1564 struct mbuf *m; 1565{ 1566 struct m_tag *mtag; 1567 1568 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1569 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1570} 1571 1572void 1573ip6_delaux(m) 1574 struct mbuf *m; 1575{ 1576 struct m_tag *mtag; 1577 1578 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1579 if (mtag) 1580 m_tag_delete(m, mtag); 1581} 1582 1583/* 1584 * System control for IP6 1585 */ 1586 1587u_char inet6ctlerrmap[PRC_NCMDS] = { 1588 0, 0, 0, 0, 1589 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1590 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1591 EMSGSIZE, EHOSTUNREACH, 0, 0, 1592 0, 0, 0, 0, 1593 ENOPROTOOPT 1594}; 1595