ip6_input.c revision 154804
1/* $FreeBSD: head/sys/netinet6/ip6_input.c 154804 2006-01-25 08:17:02Z ume $ */ 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_ip6fw.h" 65#include "opt_inet.h" 66#include "opt_inet6.h" 67#include "opt_ipsec.h" 68 69#include <sys/param.h> 70#include <sys/systm.h> 71#include <sys/malloc.h> 72#include <sys/mbuf.h> 73#include <sys/proc.h> 74#include <sys/domain.h> 75#include <sys/protosw.h> 76#include <sys/socket.h> 77#include <sys/socketvar.h> 78#include <sys/errno.h> 79#include <sys/time.h> 80#include <sys/kernel.h> 81#include <sys/syslog.h> 82 83#include <net/if.h> 84#include <net/if_types.h> 85#include <net/if_dl.h> 86#include <net/route.h> 87#include <net/netisr.h> 88#include <net/pfil.h> 89 90#include <netinet/in.h> 91#include <netinet/in_systm.h> 92#ifdef INET 93#include <netinet/ip.h> 94#include <netinet/ip_icmp.h> 95#endif /* INET */ 96#include <netinet/ip6.h> 97#include <netinet6/in6_var.h> 98#include <netinet6/ip6_var.h> 99#include <netinet/in_pcb.h> 100#include <netinet/icmp6.h> 101#include <netinet6/scope6_var.h> 102#include <netinet6/in6_ifattach.h> 103#include <netinet6/nd6.h> 104 105#ifdef IPSEC 106#include <netinet6/ipsec.h> 107#ifdef INET6 108#include <netinet6/ipsec6.h> 109#endif 110#endif 111 112#ifdef FAST_IPSEC 113#include <netipsec/ipsec.h> 114#include <netipsec/ipsec6.h> 115#define IPSEC 116#endif /* FAST_IPSEC */ 117 118#include <netinet6/ip6_fw.h> 119 120#include <netinet6/ip6protosw.h> 121 122#include <net/net_osdep.h> 123 124extern struct domain inet6domain; 125 126u_char ip6_protox[IPPROTO_MAX]; 127static struct ifqueue ip6intrq; 128static int ip6qmaxlen = IFQ_MAXLEN; 129struct in6_ifaddr *in6_ifaddr; 130 131extern struct callout in6_tmpaddrtimer_ch; 132 133int ip6_forward_srcrt; /* XXX */ 134int ip6_sourcecheck; /* XXX */ 135int ip6_sourcecheck_interval; /* XXX */ 136 137int ip6_ours_check_algorithm; 138 139struct pfil_head inet6_pfil_hook; 140 141/* firewall hooks */ 142ip6_fw_chk_t *ip6_fw_chk_ptr; 143ip6_fw_ctl_t *ip6_fw_ctl_ptr; 144int ip6_fw_enable = 1; 145 146struct ip6stat ip6stat; 147 148static void ip6_init2 __P((void *)); 149static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 150static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 151#ifdef PULLDOWN_TEST 152static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 153#endif 154 155/* 156 * IP6 initialization: fill in IP6 protocol switch table. 157 * All protocols not implemented in kernel go to raw IP6 protocol handler. 158 */ 159void 160ip6_init() 161{ 162 struct ip6protosw *pr; 163 int i; 164 165#ifdef DIAGNOSTIC 166 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 167 panic("sizeof(protosw) != sizeof(ip6protosw)"); 168#endif 169 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 170 if (pr == 0) 171 panic("ip6_init"); 172 173 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 174 for (i = 0; i < IPPROTO_MAX; i++) 175 ip6_protox[i] = pr - inet6sw; 176 /* 177 * Cycle through IP protocols and put them into the appropriate place 178 * in ip6_protox[]. 179 */ 180 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 181 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 182 if (pr->pr_domain->dom_family == PF_INET6 && 183 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 184 /* Be careful to only index valid IP protocols. */ 185 if (pr->pr_protocol < IPPROTO_MAX) 186 ip6_protox[pr->pr_protocol] = pr - inet6sw; 187 } 188 189 /* Initialize packet filter hooks. */ 190 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 191 inet6_pfil_hook.ph_af = AF_INET6; 192 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 193 printf("%s: WARNING: unable to register pfil hook, " 194 "error %d\n", __func__, i); 195 196 ip6intrq.ifq_maxlen = ip6qmaxlen; 197 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 198 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 199 scope6_init(); 200 addrsel_policy_init(); 201 nd6_init(); 202 frag6_init(); 203 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 204} 205 206static void 207ip6_init2(dummy) 208 void *dummy; 209{ 210 211 /* nd6_timer_init */ 212 callout_init(&nd6_timer_ch, 0); 213 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 214 215 /* timer for regeneranation of temporary addresses randomize ID */ 216 callout_init(&in6_tmpaddrtimer_ch, 0); 217 callout_reset(&in6_tmpaddrtimer_ch, 218 (ip6_temp_preferred_lifetime - ip6_desync_factor - 219 ip6_temp_regen_advance) * hz, 220 in6_tmpaddrtimer, NULL); 221} 222 223/* cheat */ 224/* This must be after route_init(), which is now SI_ORDER_THIRD */ 225SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 226 227extern struct route_in6 ip6_forward_rt; 228 229void 230ip6_input(m) 231 struct mbuf *m; 232{ 233 struct ip6_hdr *ip6; 234 int off = sizeof(struct ip6_hdr), nest; 235 u_int32_t plen; 236 u_int32_t rtalert = ~0; 237 int nxt, ours = 0; 238 struct ifnet *deliverifp = NULL; 239 struct in6_addr odst; 240 int srcrt = 0; 241 242 GIANT_REQUIRED; /* XXX for now */ 243#ifdef IPSEC 244 /* 245 * should the inner packet be considered authentic? 246 * see comment in ah4_input(). 247 */ 248 if (m) { 249 m->m_flags &= ~M_AUTHIPHDR; 250 m->m_flags &= ~M_AUTHIPDGM; 251 } 252#endif 253 254 /* 255 * make sure we don't have onion peering information into m_tag. 256 */ 257 ip6_delaux(m); 258 259 /* 260 * mbuf statistics 261 */ 262 if (m->m_flags & M_EXT) { 263 if (m->m_next) 264 ip6stat.ip6s_mext2m++; 265 else 266 ip6stat.ip6s_mext1++; 267 } else { 268#define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 269 if (m->m_next) { 270 if (m->m_flags & M_LOOP) { 271 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 272 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 273 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 274 else 275 ip6stat.ip6s_m2m[0]++; 276 } else 277 ip6stat.ip6s_m1++; 278#undef M2MMAX 279 } 280 281 /* drop the packet if IPv6 operation is disabled on the IF */ 282 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 283 m_freem(m); 284 return; 285 } 286 287 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 288 ip6stat.ip6s_total++; 289 290#ifndef PULLDOWN_TEST 291 /* 292 * L2 bridge code and some other code can return mbuf chain 293 * that does not conform to KAME requirement. too bad. 294 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 295 */ 296 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 297 struct mbuf *n; 298 299 MGETHDR(n, M_DONTWAIT, MT_HEADER); 300 if (n) 301 M_MOVE_PKTHDR(n, m); 302 if (n && n->m_pkthdr.len > MHLEN) { 303 MCLGET(n, M_DONTWAIT); 304 if ((n->m_flags & M_EXT) == 0) { 305 m_freem(n); 306 n = NULL; 307 } 308 } 309 if (n == NULL) { 310 m_freem(m); 311 return; /* ENOBUFS */ 312 } 313 314 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 315 n->m_len = n->m_pkthdr.len; 316 m_freem(m); 317 m = n; 318 } 319 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 320#endif 321 322 if (m->m_len < sizeof(struct ip6_hdr)) { 323 struct ifnet *inifp; 324 inifp = m->m_pkthdr.rcvif; 325 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 326 ip6stat.ip6s_toosmall++; 327 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 328 return; 329 } 330 } 331 332 ip6 = mtod(m, struct ip6_hdr *); 333 334 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 335 ip6stat.ip6s_badvers++; 336 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 337 goto bad; 338 } 339 340 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 341 342 /* 343 * Check against address spoofing/corruption. 344 */ 345 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 346 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 347 /* 348 * XXX: "badscope" is not very suitable for a multicast source. 349 */ 350 ip6stat.ip6s_badscope++; 351 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 352 goto bad; 353 } 354 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 355 !(m->m_flags & M_LOOP)) { 356 /* 357 * In this case, the packet should come from the loopback 358 * interface. However, we cannot just check the if_flags, 359 * because ip6_mloopback() passes the "actual" interface 360 * as the outgoing/incoming interface. 361 */ 362 ip6stat.ip6s_badscope++; 363 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 364 goto bad; 365 } 366 367#ifdef ALTQ 368 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 369 /* packet is dropped by traffic conditioner */ 370 return; 371 } 372#endif 373 /* 374 * The following check is not documented in specs. A malicious 375 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 376 * and bypass security checks (act as if it was from 127.0.0.1 by using 377 * IPv6 src ::ffff:127.0.0.1). Be cautious. 378 * 379 * This check chokes if we are in an SIIT cloud. As none of BSDs 380 * support IPv4-less kernel compilation, we cannot support SIIT 381 * environment at all. So, it makes more sense for us to reject any 382 * malicious packets for non-SIIT environment, than try to do a 383 * partial support for SIIT environment. 384 */ 385 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 386 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 387 ip6stat.ip6s_badscope++; 388 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 389 goto bad; 390 } 391#if 0 392 /* 393 * Reject packets with IPv4 compatible addresses (auto tunnel). 394 * 395 * The code forbids auto tunnel relay case in RFC1933 (the check is 396 * stronger than RFC1933). We may want to re-enable it if mech-xx 397 * is revised to forbid relaying case. 398 */ 399 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 400 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 401 ip6stat.ip6s_badscope++; 402 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 403 goto bad; 404 } 405#endif 406 407 /* 408 * Run through list of hooks for input packets. 409 * 410 * NB: Beware of the destination address changing 411 * (e.g. by NAT rewriting). When this happens, 412 * tell ip6_forward to do the right thing. 413 */ 414 odst = ip6->ip6_dst; 415 416 /* Jump over all PFIL processing if hooks are not active. */ 417 if (inet6_pfil_hook.ph_busy_count == -1) 418 goto passin; 419 420 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 421 return; 422 if (m == NULL) /* consumed by filter */ 423 return; 424 ip6 = mtod(m, struct ip6_hdr *); 425 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 426 427passin: 428 /* 429 * Check with the firewall... 430 */ 431 if (ip6_fw_enable && ip6_fw_chk_ptr) { 432 u_short port = 0; 433 /* If ipfw says divert, we have to just drop packet */ 434 /* use port as a dummy argument */ 435 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 436 m_freem(m); 437 m = NULL; 438 } 439 if (!m) 440 return; 441 } 442 443 /* 444 * Disambiguate address scope zones (if there is ambiguity). 445 * We first make sure that the original source or destination address 446 * is not in our internal form for scoped addresses. Such addresses 447 * are not necessarily invalid spec-wise, but we cannot accept them due 448 * to the usage conflict. 449 * in6_setscope() then also checks and rejects the cases where src or 450 * dst are the loopback address and the receiving interface 451 * is not loopback. 452 */ 453 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 454 ip6stat.ip6s_badscope++; /* XXX */ 455 goto bad; 456 } 457 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 458 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 459 ip6stat.ip6s_badscope++; 460 goto bad; 461 } 462 463 /* 464 * Multicast check 465 */ 466 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 467 struct in6_multi *in6m = 0; 468 469 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 470 /* 471 * See if we belong to the destination multicast group on the 472 * arrival interface. 473 */ 474 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 475 if (in6m) 476 ours = 1; 477 else if (!ip6_mrouter) { 478 ip6stat.ip6s_notmember++; 479 ip6stat.ip6s_cantforward++; 480 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 481 goto bad; 482 } 483 deliverifp = m->m_pkthdr.rcvif; 484 goto hbhcheck; 485 } 486 487 /* 488 * Unicast check 489 */ 490 if (ip6_forward_rt.ro_rt != NULL && 491 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 492 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 493 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 494 ip6stat.ip6s_forward_cachehit++; 495 else { 496 struct sockaddr_in6 *dst6; 497 498 if (ip6_forward_rt.ro_rt) { 499 /* route is down or destination is different */ 500 ip6stat.ip6s_forward_cachemiss++; 501 RTFREE(ip6_forward_rt.ro_rt); 502 ip6_forward_rt.ro_rt = 0; 503 } 504 505 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 506 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 507 dst6->sin6_len = sizeof(struct sockaddr_in6); 508 dst6->sin6_family = AF_INET6; 509 dst6->sin6_addr = ip6->ip6_dst; 510 511 rtalloc((struct route *)&ip6_forward_rt); 512 } 513 514#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 515 516 /* 517 * Accept the packet if the forwarding interface to the destination 518 * according to the routing table is the loopback interface, 519 * unless the associated route has a gateway. 520 * Note that this approach causes to accept a packet if there is a 521 * route to the loopback interface for the destination of the packet. 522 * But we think it's even useful in some situations, e.g. when using 523 * a special daemon which wants to intercept the packet. 524 * 525 * XXX: some OSes automatically make a cloned route for the destination 526 * of an outgoing packet. If the outgoing interface of the packet 527 * is a loopback one, the kernel would consider the packet to be 528 * accepted, even if we have no such address assinged on the interface. 529 * We check the cloned flag of the route entry to reject such cases, 530 * assuming that route entries for our own addresses are not made by 531 * cloning (it should be true because in6_addloop explicitly installs 532 * the host route). However, we might have to do an explicit check 533 * while it would be less efficient. Or, should we rather install a 534 * reject route for such a case? 535 */ 536 if (ip6_forward_rt.ro_rt && 537 (ip6_forward_rt.ro_rt->rt_flags & 538 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 539#ifdef RTF_WASCLONED 540 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 541#endif 542#ifdef RTF_CLONED 543 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 544#endif 545#if 0 546 /* 547 * The check below is redundant since the comparison of 548 * the destination and the key of the rtentry has 549 * already done through looking up the routing table. 550 */ 551 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 552 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 553#endif 554 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 555 struct in6_ifaddr *ia6 = 556 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 557 558 /* 559 * record address information into m_tag. 560 */ 561 (void)ip6_setdstifaddr(m, ia6); 562 563 /* 564 * packets to a tentative, duplicated, or somehow invalid 565 * address must not be accepted. 566 */ 567 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 568 /* this address is ready */ 569 ours = 1; 570 deliverifp = ia6->ia_ifp; /* correct? */ 571 /* Count the packet in the ip address stats */ 572 ia6->ia_ifa.if_ipackets++; 573 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 574 goto hbhcheck; 575 } else { 576 /* address is not ready, so discard the packet. */ 577 nd6log((LOG_INFO, 578 "ip6_input: packet to an unready address %s->%s\n", 579 ip6_sprintf(&ip6->ip6_src), 580 ip6_sprintf(&ip6->ip6_dst))); 581 582 goto bad; 583 } 584 } 585 586 /* 587 * FAITH (Firewall Aided Internet Translator) 588 */ 589 if (ip6_keepfaith) { 590 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 591 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 592 /* XXX do we need more sanity checks? */ 593 ours = 1; 594 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 595 goto hbhcheck; 596 } 597 } 598 599 /* 600 * Now there is no reason to process the packet if it's not our own 601 * and we're not a router. 602 */ 603 if (!ip6_forwarding) { 604 ip6stat.ip6s_cantforward++; 605 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 606 goto bad; 607 } 608 609 hbhcheck: 610 /* 611 * record address information into m_tag, if we don't have one yet. 612 * note that we are unable to record it, if the address is not listed 613 * as our interface address (e.g. multicast addresses, addresses 614 * within FAITH prefixes and such). 615 */ 616 if (deliverifp && !ip6_getdstifaddr(m)) { 617 struct in6_ifaddr *ia6; 618 619 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 620 if (ia6) { 621 if (!ip6_setdstifaddr(m, ia6)) { 622 /* 623 * XXX maybe we should drop the packet here, 624 * as we could not provide enough information 625 * to the upper layers. 626 */ 627 } 628 } 629 } 630 631 /* 632 * Process Hop-by-Hop options header if it's contained. 633 * m may be modified in ip6_hopopts_input(). 634 * If a JumboPayload option is included, plen will also be modified. 635 */ 636 plen = (u_int32_t)ntohs(ip6->ip6_plen); 637 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 638 struct ip6_hbh *hbh; 639 640 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 641#if 0 /*touches NULL pointer*/ 642 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 643#endif 644 return; /* m have already been freed */ 645 } 646 647 /* adjust pointer */ 648 ip6 = mtod(m, struct ip6_hdr *); 649 650 /* 651 * if the payload length field is 0 and the next header field 652 * indicates Hop-by-Hop Options header, then a Jumbo Payload 653 * option MUST be included. 654 */ 655 if (ip6->ip6_plen == 0 && plen == 0) { 656 /* 657 * Note that if a valid jumbo payload option is 658 * contained, ip6_hopopts_input() must set a valid 659 * (non-zero) payload length to the variable plen. 660 */ 661 ip6stat.ip6s_badoptions++; 662 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 663 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 664 icmp6_error(m, ICMP6_PARAM_PROB, 665 ICMP6_PARAMPROB_HEADER, 666 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 667 return; 668 } 669#ifndef PULLDOWN_TEST 670 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 671 hbh = (struct ip6_hbh *)(ip6 + 1); 672#else 673 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 674 sizeof(struct ip6_hbh)); 675 if (hbh == NULL) { 676 ip6stat.ip6s_tooshort++; 677 return; 678 } 679#endif 680 nxt = hbh->ip6h_nxt; 681 682 /* 683 * accept the packet if a router alert option is included 684 * and we act as an IPv6 router. 685 */ 686 if (rtalert != ~0 && ip6_forwarding) 687 ours = 1; 688 } else 689 nxt = ip6->ip6_nxt; 690 691 /* 692 * Check that the amount of data in the buffers 693 * is as at least much as the IPv6 header would have us expect. 694 * Trim mbufs if longer than we expect. 695 * Drop packet if shorter than we expect. 696 */ 697 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 698 ip6stat.ip6s_tooshort++; 699 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 700 goto bad; 701 } 702 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 703 if (m->m_len == m->m_pkthdr.len) { 704 m->m_len = sizeof(struct ip6_hdr) + plen; 705 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 706 } else 707 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 708 } 709 710 /* 711 * Forward if desirable. 712 */ 713 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 714 /* 715 * If we are acting as a multicast router, all 716 * incoming multicast packets are passed to the 717 * kernel-level multicast forwarding function. 718 * The packet is returned (relatively) intact; if 719 * ip6_mforward() returns a non-zero value, the packet 720 * must be discarded, else it may be accepted below. 721 */ 722 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 723 ip6stat.ip6s_cantforward++; 724 m_freem(m); 725 return; 726 } 727 if (!ours) { 728 m_freem(m); 729 return; 730 } 731 } else if (!ours) { 732 ip6_forward(m, srcrt); 733 return; 734 } 735 736 ip6 = mtod(m, struct ip6_hdr *); 737 738 /* 739 * Malicious party may be able to use IPv4 mapped addr to confuse 740 * tcp/udp stack and bypass security checks (act as if it was from 741 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 742 * 743 * For SIIT end node behavior, you may want to disable the check. 744 * However, you will become vulnerable to attacks using IPv4 mapped 745 * source. 746 */ 747 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 748 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 749 ip6stat.ip6s_badscope++; 750 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 751 goto bad; 752 } 753 754 /* 755 * Tell launch routine the next header 756 */ 757 ip6stat.ip6s_delivered++; 758 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 759 nest = 0; 760 761 while (nxt != IPPROTO_DONE) { 762 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 763 ip6stat.ip6s_toomanyhdr++; 764 goto bad; 765 } 766 767 /* 768 * protection against faulty packet - there should be 769 * more sanity checks in header chain processing. 770 */ 771 if (m->m_pkthdr.len < off) { 772 ip6stat.ip6s_tooshort++; 773 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 774 goto bad; 775 } 776 777#ifdef IPSEC 778 /* 779 * enforce IPsec policy checking if we are seeing last header. 780 * note that we do not visit this with protocols with pcb layer 781 * code - like udp/tcp/raw ip. 782 */ 783 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 784 ipsec6_in_reject(m, NULL)) { 785 ipsec6stat.in_polvio++; 786 goto bad; 787 } 788#endif 789 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 790 } 791 return; 792 bad: 793 m_freem(m); 794} 795 796/* 797 * set/grab in6_ifaddr correspond to IPv6 destination address. 798 * XXX backward compatibility wrapper 799 */ 800static struct ip6aux * 801ip6_setdstifaddr(m, ia6) 802 struct mbuf *m; 803 struct in6_ifaddr *ia6; 804{ 805 struct ip6aux *ip6a; 806 807 ip6a = ip6_addaux(m); 808 if (ip6a) 809 ip6a->ip6a_dstia6 = ia6; 810 return ip6a; /* NULL if failed to set */ 811} 812 813struct in6_ifaddr * 814ip6_getdstifaddr(m) 815 struct mbuf *m; 816{ 817 struct ip6aux *ip6a; 818 819 ip6a = ip6_findaux(m); 820 if (ip6a) 821 return ip6a->ip6a_dstia6; 822 else 823 return NULL; 824} 825 826/* 827 * Hop-by-Hop options header processing. If a valid jumbo payload option is 828 * included, the real payload length will be stored in plenp. 829 */ 830static int 831ip6_hopopts_input(plenp, rtalertp, mp, offp) 832 u_int32_t *plenp; 833 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 834 struct mbuf **mp; 835 int *offp; 836{ 837 struct mbuf *m = *mp; 838 int off = *offp, hbhlen; 839 struct ip6_hbh *hbh; 840 u_int8_t *opt; 841 842 /* validation of the length of the header */ 843#ifndef PULLDOWN_TEST 844 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 845 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 846 hbhlen = (hbh->ip6h_len + 1) << 3; 847 848 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 849 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 850#else 851 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 852 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 853 if (hbh == NULL) { 854 ip6stat.ip6s_tooshort++; 855 return -1; 856 } 857 hbhlen = (hbh->ip6h_len + 1) << 3; 858 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 859 hbhlen); 860 if (hbh == NULL) { 861 ip6stat.ip6s_tooshort++; 862 return -1; 863 } 864#endif 865 off += hbhlen; 866 hbhlen -= sizeof(struct ip6_hbh); 867 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 868 869 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 870 hbhlen, rtalertp, plenp) < 0) 871 return (-1); 872 873 *offp = off; 874 *mp = m; 875 return (0); 876} 877 878/* 879 * Search header for all Hop-by-hop options and process each option. 880 * This function is separate from ip6_hopopts_input() in order to 881 * handle a case where the sending node itself process its hop-by-hop 882 * options header. In such a case, the function is called from ip6_output(). 883 * 884 * The function assumes that hbh header is located right after the IPv6 header 885 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 886 * opthead + hbhlen is located in continuous memory region. 887 */ 888int 889ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 890 struct mbuf *m; 891 u_int8_t *opthead; 892 int hbhlen; 893 u_int32_t *rtalertp; 894 u_int32_t *plenp; 895{ 896 struct ip6_hdr *ip6; 897 int optlen = 0; 898 u_int8_t *opt = opthead; 899 u_int16_t rtalert_val; 900 u_int32_t jumboplen; 901 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 902 903 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 904 switch (*opt) { 905 case IP6OPT_PAD1: 906 optlen = 1; 907 break; 908 case IP6OPT_PADN: 909 if (hbhlen < IP6OPT_MINLEN) { 910 ip6stat.ip6s_toosmall++; 911 goto bad; 912 } 913 optlen = *(opt + 1) + 2; 914 break; 915 case IP6OPT_ROUTER_ALERT: 916 /* XXX may need check for alignment */ 917 if (hbhlen < IP6OPT_RTALERT_LEN) { 918 ip6stat.ip6s_toosmall++; 919 goto bad; 920 } 921 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 922 /* XXX stat */ 923 icmp6_error(m, ICMP6_PARAM_PROB, 924 ICMP6_PARAMPROB_HEADER, 925 erroff + opt + 1 - opthead); 926 return (-1); 927 } 928 optlen = IP6OPT_RTALERT_LEN; 929 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 930 *rtalertp = ntohs(rtalert_val); 931 break; 932 case IP6OPT_JUMBO: 933 /* XXX may need check for alignment */ 934 if (hbhlen < IP6OPT_JUMBO_LEN) { 935 ip6stat.ip6s_toosmall++; 936 goto bad; 937 } 938 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 939 /* XXX stat */ 940 icmp6_error(m, ICMP6_PARAM_PROB, 941 ICMP6_PARAMPROB_HEADER, 942 erroff + opt + 1 - opthead); 943 return (-1); 944 } 945 optlen = IP6OPT_JUMBO_LEN; 946 947 /* 948 * IPv6 packets that have non 0 payload length 949 * must not contain a jumbo payload option. 950 */ 951 ip6 = mtod(m, struct ip6_hdr *); 952 if (ip6->ip6_plen) { 953 ip6stat.ip6s_badoptions++; 954 icmp6_error(m, ICMP6_PARAM_PROB, 955 ICMP6_PARAMPROB_HEADER, 956 erroff + opt - opthead); 957 return (-1); 958 } 959 960 /* 961 * We may see jumbolen in unaligned location, so 962 * we'd need to perform bcopy(). 963 */ 964 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 965 jumboplen = (u_int32_t)htonl(jumboplen); 966 967#if 1 968 /* 969 * if there are multiple jumbo payload options, 970 * *plenp will be non-zero and the packet will be 971 * rejected. 972 * the behavior may need some debate in ipngwg - 973 * multiple options does not make sense, however, 974 * there's no explicit mention in specification. 975 */ 976 if (*plenp != 0) { 977 ip6stat.ip6s_badoptions++; 978 icmp6_error(m, ICMP6_PARAM_PROB, 979 ICMP6_PARAMPROB_HEADER, 980 erroff + opt + 2 - opthead); 981 return (-1); 982 } 983#endif 984 985 /* 986 * jumbo payload length must be larger than 65535. 987 */ 988 if (jumboplen <= IPV6_MAXPACKET) { 989 ip6stat.ip6s_badoptions++; 990 icmp6_error(m, ICMP6_PARAM_PROB, 991 ICMP6_PARAMPROB_HEADER, 992 erroff + opt + 2 - opthead); 993 return (-1); 994 } 995 *plenp = jumboplen; 996 997 break; 998 default: /* unknown option */ 999 if (hbhlen < IP6OPT_MINLEN) { 1000 ip6stat.ip6s_toosmall++; 1001 goto bad; 1002 } 1003 optlen = ip6_unknown_opt(opt, m, 1004 erroff + opt - opthead); 1005 if (optlen == -1) 1006 return (-1); 1007 optlen += 2; 1008 break; 1009 } 1010 } 1011 1012 return (0); 1013 1014 bad: 1015 m_freem(m); 1016 return (-1); 1017} 1018 1019/* 1020 * Unknown option processing. 1021 * The third argument `off' is the offset from the IPv6 header to the option, 1022 * which is necessary if the IPv6 header the and option header and IPv6 header 1023 * is not continuous in order to return an ICMPv6 error. 1024 */ 1025int 1026ip6_unknown_opt(optp, m, off) 1027 u_int8_t *optp; 1028 struct mbuf *m; 1029 int off; 1030{ 1031 struct ip6_hdr *ip6; 1032 1033 switch (IP6OPT_TYPE(*optp)) { 1034 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1035 return ((int)*(optp + 1)); 1036 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1037 m_freem(m); 1038 return (-1); 1039 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1040 ip6stat.ip6s_badoptions++; 1041 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1042 return (-1); 1043 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1044 ip6stat.ip6s_badoptions++; 1045 ip6 = mtod(m, struct ip6_hdr *); 1046 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1047 (m->m_flags & (M_BCAST|M_MCAST))) 1048 m_freem(m); 1049 else 1050 icmp6_error(m, ICMP6_PARAM_PROB, 1051 ICMP6_PARAMPROB_OPTION, off); 1052 return (-1); 1053 } 1054 1055 m_freem(m); /* XXX: NOTREACHED */ 1056 return (-1); 1057} 1058 1059/* 1060 * Create the "control" list for this pcb. 1061 * The function will not modify mbuf chain at all. 1062 * 1063 * with KAME mbuf chain restriction: 1064 * The routine will be called from upper layer handlers like tcp6_input(). 1065 * Thus the routine assumes that the caller (tcp6_input) have already 1066 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1067 * very first mbuf on the mbuf chain. 1068 */ 1069void 1070ip6_savecontrol(in6p, m, mp) 1071 struct inpcb *in6p; 1072 struct mbuf *m, **mp; 1073{ 1074#define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1075 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1076 1077#ifdef SO_TIMESTAMP 1078 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1079 struct timeval tv; 1080 1081 microtime(&tv); 1082 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1083 SCM_TIMESTAMP, SOL_SOCKET); 1084 if (*mp) 1085 mp = &(*mp)->m_next; 1086 } 1087#endif 1088 1089 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1090 return; 1091 1092 /* RFC 2292 sec. 5 */ 1093 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1094 struct in6_pktinfo pi6; 1095 1096 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1097 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1098 pi6.ipi6_ifindex = 1099 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1100 1101 *mp = sbcreatecontrol((caddr_t) &pi6, 1102 sizeof(struct in6_pktinfo), 1103 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1104 if (*mp) 1105 mp = &(*mp)->m_next; 1106 } 1107 1108 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1109 int hlim = ip6->ip6_hlim & 0xff; 1110 1111 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1112 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1113 if (*mp) 1114 mp = &(*mp)->m_next; 1115 } 1116 1117 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1118 u_int32_t flowinfo; 1119 int tclass; 1120 1121 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1122 flowinfo >>= 20; 1123 1124 tclass = flowinfo & 0xff; 1125 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1126 IPV6_TCLASS, IPPROTO_IPV6); 1127 if (*mp) 1128 mp = &(*mp)->m_next; 1129 } 1130 1131 /* 1132 * IPV6_HOPOPTS socket option. Recall that we required super-user 1133 * privilege for the option (see ip6_ctloutput), but it might be too 1134 * strict, since there might be some hop-by-hop options which can be 1135 * returned to normal user. 1136 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1137 */ 1138 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1139 /* 1140 * Check if a hop-by-hop options header is contatined in the 1141 * received packet, and if so, store the options as ancillary 1142 * data. Note that a hop-by-hop options header must be 1143 * just after the IPv6 header, which is assured through the 1144 * IPv6 input processing. 1145 */ 1146 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1147 struct ip6_hbh *hbh; 1148 int hbhlen = 0; 1149#ifdef PULLDOWN_TEST 1150 struct mbuf *ext; 1151#endif 1152 1153#ifndef PULLDOWN_TEST 1154 hbh = (struct ip6_hbh *)(ip6 + 1); 1155 hbhlen = (hbh->ip6h_len + 1) << 3; 1156#else 1157 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1158 ip6->ip6_nxt); 1159 if (ext == NULL) { 1160 ip6stat.ip6s_tooshort++; 1161 return; 1162 } 1163 hbh = mtod(ext, struct ip6_hbh *); 1164 hbhlen = (hbh->ip6h_len + 1) << 3; 1165 if (hbhlen != ext->m_len) { 1166 m_freem(ext); 1167 ip6stat.ip6s_tooshort++; 1168 return; 1169 } 1170#endif 1171 1172 /* 1173 * XXX: We copy the whole header even if a 1174 * jumbo payload option is included, the option which 1175 * is to be removed before returning according to 1176 * RFC2292. 1177 * Note: this constraint is removed in RFC3542 1178 */ 1179 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1180 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1181 IPPROTO_IPV6); 1182 if (*mp) 1183 mp = &(*mp)->m_next; 1184#ifdef PULLDOWN_TEST 1185 m_freem(ext); 1186#endif 1187 } 1188 } 1189 1190 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1191 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1192 1193 /* 1194 * Search for destination options headers or routing 1195 * header(s) through the header chain, and stores each 1196 * header as ancillary data. 1197 * Note that the order of the headers remains in 1198 * the chain of ancillary data. 1199 */ 1200 while (1) { /* is explicit loop prevention necessary? */ 1201 struct ip6_ext *ip6e = NULL; 1202 int elen; 1203#ifdef PULLDOWN_TEST 1204 struct mbuf *ext = NULL; 1205#endif 1206 1207 /* 1208 * if it is not an extension header, don't try to 1209 * pull it from the chain. 1210 */ 1211 switch (nxt) { 1212 case IPPROTO_DSTOPTS: 1213 case IPPROTO_ROUTING: 1214 case IPPROTO_HOPOPTS: 1215 case IPPROTO_AH: /* is it possible? */ 1216 break; 1217 default: 1218 goto loopend; 1219 } 1220 1221#ifndef PULLDOWN_TEST 1222 if (off + sizeof(*ip6e) > m->m_len) 1223 goto loopend; 1224 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1225 if (nxt == IPPROTO_AH) 1226 elen = (ip6e->ip6e_len + 2) << 2; 1227 else 1228 elen = (ip6e->ip6e_len + 1) << 3; 1229 if (off + elen > m->m_len) 1230 goto loopend; 1231#else 1232 ext = ip6_pullexthdr(m, off, nxt); 1233 if (ext == NULL) { 1234 ip6stat.ip6s_tooshort++; 1235 return; 1236 } 1237 ip6e = mtod(ext, struct ip6_ext *); 1238 if (nxt == IPPROTO_AH) 1239 elen = (ip6e->ip6e_len + 2) << 2; 1240 else 1241 elen = (ip6e->ip6e_len + 1) << 3; 1242 if (elen != ext->m_len) { 1243 m_freem(ext); 1244 ip6stat.ip6s_tooshort++; 1245 return; 1246 } 1247#endif 1248 1249 switch (nxt) { 1250 case IPPROTO_DSTOPTS: 1251 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1252 break; 1253 1254 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1255 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1256 IPPROTO_IPV6); 1257 if (*mp) 1258 mp = &(*mp)->m_next; 1259 break; 1260 case IPPROTO_ROUTING: 1261 if (!in6p->in6p_flags & IN6P_RTHDR) 1262 break; 1263 1264 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1265 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1266 IPPROTO_IPV6); 1267 if (*mp) 1268 mp = &(*mp)->m_next; 1269 break; 1270 case IPPROTO_HOPOPTS: 1271 case IPPROTO_AH: /* is it possible? */ 1272 break; 1273 1274 default: 1275 /* 1276 * other cases have been filtered in the above. 1277 * none will visit this case. here we supply 1278 * the code just in case (nxt overwritten or 1279 * other cases). 1280 */ 1281#ifdef PULLDOWN_TEST 1282 m_freem(ext); 1283#endif 1284 goto loopend; 1285 1286 } 1287 1288 /* proceed with the next header. */ 1289 off += elen; 1290 nxt = ip6e->ip6e_nxt; 1291 ip6e = NULL; 1292#ifdef PULLDOWN_TEST 1293 m_freem(ext); 1294 ext = NULL; 1295#endif 1296 } 1297 loopend: 1298 ; 1299 } 1300 1301#undef IS2292 1302} 1303 1304void 1305ip6_notify_pmtu(in6p, dst, mtu) 1306 struct inpcb *in6p; 1307 struct sockaddr_in6 *dst; 1308 u_int32_t *mtu; 1309{ 1310 struct socket *so; 1311 struct mbuf *m_mtu; 1312 struct ip6_mtuinfo mtuctl; 1313 1314 so = in6p->inp_socket; 1315 1316 if (mtu == NULL) 1317 return; 1318 1319#ifdef DIAGNOSTIC 1320 if (so == NULL) /* I believe this is impossible */ 1321 panic("ip6_notify_pmtu: socket is NULL"); 1322#endif 1323 1324 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1325 mtuctl.ip6m_mtu = *mtu; 1326 mtuctl.ip6m_addr = *dst; 1327 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1328 return; 1329 1330 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1331 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1332 return; 1333 1334 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1335 == 0) { 1336 m_freem(m_mtu); 1337 /* XXX: should count statistics */ 1338 } else 1339 sorwakeup(so); 1340 1341 return; 1342} 1343 1344#ifdef PULLDOWN_TEST 1345/* 1346 * pull single extension header from mbuf chain. returns single mbuf that 1347 * contains the result, or NULL on error. 1348 */ 1349static struct mbuf * 1350ip6_pullexthdr(m, off, nxt) 1351 struct mbuf *m; 1352 size_t off; 1353 int nxt; 1354{ 1355 struct ip6_ext ip6e; 1356 size_t elen; 1357 struct mbuf *n; 1358 1359#ifdef DIAGNOSTIC 1360 switch (nxt) { 1361 case IPPROTO_DSTOPTS: 1362 case IPPROTO_ROUTING: 1363 case IPPROTO_HOPOPTS: 1364 case IPPROTO_AH: /* is it possible? */ 1365 break; 1366 default: 1367 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1368 } 1369#endif 1370 1371 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1372 if (nxt == IPPROTO_AH) 1373 elen = (ip6e.ip6e_len + 2) << 2; 1374 else 1375 elen = (ip6e.ip6e_len + 1) << 3; 1376 1377 MGET(n, M_DONTWAIT, MT_DATA); 1378 if (n && elen >= MLEN) { 1379 MCLGET(n, M_DONTWAIT); 1380 if ((n->m_flags & M_EXT) == 0) { 1381 m_free(n); 1382 n = NULL; 1383 } 1384 } 1385 if (!n) 1386 return NULL; 1387 1388 n->m_len = 0; 1389 if (elen >= M_TRAILINGSPACE(n)) { 1390 m_free(n); 1391 return NULL; 1392 } 1393 1394 m_copydata(m, off, elen, mtod(n, caddr_t)); 1395 n->m_len = elen; 1396 return n; 1397} 1398#endif 1399 1400/* 1401 * Get pointer to the previous header followed by the header 1402 * currently processed. 1403 * XXX: This function supposes that 1404 * M includes all headers, 1405 * the next header field and the header length field of each header 1406 * are valid, and 1407 * the sum of each header length equals to OFF. 1408 * Because of these assumptions, this function must be called very 1409 * carefully. Moreover, it will not be used in the near future when 1410 * we develop `neater' mechanism to process extension headers. 1411 */ 1412char * 1413ip6_get_prevhdr(m, off) 1414 struct mbuf *m; 1415 int off; 1416{ 1417 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1418 1419 if (off == sizeof(struct ip6_hdr)) 1420 return (&ip6->ip6_nxt); 1421 else { 1422 int len, nxt; 1423 struct ip6_ext *ip6e = NULL; 1424 1425 nxt = ip6->ip6_nxt; 1426 len = sizeof(struct ip6_hdr); 1427 while (len < off) { 1428 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1429 1430 switch (nxt) { 1431 case IPPROTO_FRAGMENT: 1432 len += sizeof(struct ip6_frag); 1433 break; 1434 case IPPROTO_AH: 1435 len += (ip6e->ip6e_len + 2) << 2; 1436 break; 1437 default: 1438 len += (ip6e->ip6e_len + 1) << 3; 1439 break; 1440 } 1441 nxt = ip6e->ip6e_nxt; 1442 } 1443 if (ip6e) 1444 return (&ip6e->ip6e_nxt); 1445 else 1446 return NULL; 1447 } 1448} 1449 1450/* 1451 * get next header offset. m will be retained. 1452 */ 1453int 1454ip6_nexthdr(m, off, proto, nxtp) 1455 struct mbuf *m; 1456 int off; 1457 int proto; 1458 int *nxtp; 1459{ 1460 struct ip6_hdr ip6; 1461 struct ip6_ext ip6e; 1462 struct ip6_frag fh; 1463 1464 /* just in case */ 1465 if (m == NULL) 1466 panic("ip6_nexthdr: m == NULL"); 1467 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1468 return -1; 1469 1470 switch (proto) { 1471 case IPPROTO_IPV6: 1472 if (m->m_pkthdr.len < off + sizeof(ip6)) 1473 return -1; 1474 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1475 if (nxtp) 1476 *nxtp = ip6.ip6_nxt; 1477 off += sizeof(ip6); 1478 return off; 1479 1480 case IPPROTO_FRAGMENT: 1481 /* 1482 * terminate parsing if it is not the first fragment, 1483 * it does not make sense to parse through it. 1484 */ 1485 if (m->m_pkthdr.len < off + sizeof(fh)) 1486 return -1; 1487 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1488 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1489 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1490 return -1; 1491 if (nxtp) 1492 *nxtp = fh.ip6f_nxt; 1493 off += sizeof(struct ip6_frag); 1494 return off; 1495 1496 case IPPROTO_AH: 1497 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1498 return -1; 1499 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1500 if (nxtp) 1501 *nxtp = ip6e.ip6e_nxt; 1502 off += (ip6e.ip6e_len + 2) << 2; 1503 return off; 1504 1505 case IPPROTO_HOPOPTS: 1506 case IPPROTO_ROUTING: 1507 case IPPROTO_DSTOPTS: 1508 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1509 return -1; 1510 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1511 if (nxtp) 1512 *nxtp = ip6e.ip6e_nxt; 1513 off += (ip6e.ip6e_len + 1) << 3; 1514 return off; 1515 1516 case IPPROTO_NONE: 1517 case IPPROTO_ESP: 1518 case IPPROTO_IPCOMP: 1519 /* give up */ 1520 return -1; 1521 1522 default: 1523 return -1; 1524 } 1525 1526 return -1; 1527} 1528 1529/* 1530 * get offset for the last header in the chain. m will be kept untainted. 1531 */ 1532int 1533ip6_lasthdr(m, off, proto, nxtp) 1534 struct mbuf *m; 1535 int off; 1536 int proto; 1537 int *nxtp; 1538{ 1539 int newoff; 1540 int nxt; 1541 1542 if (!nxtp) { 1543 nxt = -1; 1544 nxtp = &nxt; 1545 } 1546 while (1) { 1547 newoff = ip6_nexthdr(m, off, proto, nxtp); 1548 if (newoff < 0) 1549 return off; 1550 else if (newoff < off) 1551 return -1; /* invalid */ 1552 else if (newoff == off) 1553 return newoff; 1554 1555 off = newoff; 1556 proto = *nxtp; 1557 } 1558} 1559 1560struct ip6aux * 1561ip6_addaux(m) 1562 struct mbuf *m; 1563{ 1564 struct m_tag *mtag; 1565 1566 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1567 if (!mtag) { 1568 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1569 M_NOWAIT); 1570 if (mtag) { 1571 m_tag_prepend(m, mtag); 1572 bzero(mtag + 1, sizeof(struct ip6aux)); 1573 } 1574 } 1575 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1576} 1577 1578struct ip6aux * 1579ip6_findaux(m) 1580 struct mbuf *m; 1581{ 1582 struct m_tag *mtag; 1583 1584 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1585 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1586} 1587 1588void 1589ip6_delaux(m) 1590 struct mbuf *m; 1591{ 1592 struct m_tag *mtag; 1593 1594 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1595 if (mtag) 1596 m_tag_delete(m, mtag); 1597} 1598 1599/* 1600 * System control for IP6 1601 */ 1602 1603u_char inet6ctlerrmap[PRC_NCMDS] = { 1604 0, 0, 0, 0, 1605 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1606 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1607 EMSGSIZE, EHOSTUNREACH, 0, 0, 1608 0, 0, 0, 0, 1609 ENOPROTOOPT 1610}; 1611