1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1988, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 #include "opt_ipsec.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/proc.h> 75 #include <sys/domain.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/errno.h> 80 #include <sys/time.h> 81 #include <sys/kernel.h> 82 #include <sys/syslog.h> 83 84 #include <net/if.h> 85 #include <net/if_types.h> 86 #include <net/if_dl.h> 87 #include <net/route.h> 88 #include <net/netisr.h> 89 #include <net/pfil.h> 90 91 #include <netinet/in.h> 92 #include <netinet/in_systm.h> 93 #ifdef INET 94 #include <netinet/ip.h> 95 #include <netinet/ip_icmp.h> 96 #endif /* INET */ 97 #include <netinet/ip6.h> 98 #include <netinet6/in6_var.h> 99 #include <netinet6/ip6_var.h> 100 #include <netinet/in_pcb.h> 101 #include <netinet/icmp6.h> 102 #include <netinet6/scope6_var.h> 103 #include <netinet6/in6_ifattach.h> 104 #include <netinet6/nd6.h> 105 106 #ifdef IPSEC 107 #include <netipsec/ipsec.h> 108 #include <netinet6/ip6_ipsec.h> 109 #include <netipsec/ipsec6.h> 110 #endif /* IPSEC */ 111 112 #include <netinet6/ip6protosw.h> 113 114 extern struct domain inet6domain; 115 116 u_char ip6_protox[IPPROTO_MAX]; 117 static struct ifqueue ip6intrq; 118 static int ip6qmaxlen = IFQ_MAXLEN; 119 struct in6_ifaddr *in6_ifaddr; 120 121 extern struct callout in6_tmpaddrtimer_ch; 122 123 int ip6_forward_srcrt; /* XXX */ 124 int ip6_sourcecheck; /* XXX */ 125 int ip6_sourcecheck_interval; /* XXX */ 126 127 int ip6_ours_check_algorithm; 128 129 struct pfil_head inet6_pfil_hook; 130 131 struct ip6stat ip6stat; 132 133 static void ip6_init2(void *); 134 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 135 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 136 #ifdef PULLDOWN_TEST 137 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 138 #endif 139 140 /* 141 * IP6 initialization: fill in IP6 protocol switch table. 142 * All protocols not implemented in kernel go to raw IP6 protocol handler. 143 */ 144 void 145 ip6_init(void) 146 { 147 struct ip6protosw *pr; 148 int i; 149 150 #ifdef DIAGNOSTIC 151 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 152 panic("sizeof(protosw) != sizeof(ip6protosw)"); 153 #endif 154 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 155 if (pr == 0) 156 panic("ip6_init"); 157 158 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 159 for (i = 0; i < IPPROTO_MAX; i++) 160 ip6_protox[i] = pr - inet6sw; 161 /* 162 * Cycle through IP protocols and put them into the appropriate place 163 * in ip6_protox[]. 164 */ 165 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 166 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 167 if (pr->pr_domain->dom_family == PF_INET6 && 168 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 169 /* Be careful to only index valid IP protocols. */ 170 if (pr->pr_protocol < IPPROTO_MAX) 171 ip6_protox[pr->pr_protocol] = pr - inet6sw; 172 } 173 174 /* Initialize packet filter hooks. */ 175 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 176 inet6_pfil_hook.ph_af = AF_INET6; 177 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 178 printf("%s: WARNING: unable to register pfil hook, " 179 "error %d\n", __func__, i); 180 181 ip6intrq.ifq_maxlen = ip6qmaxlen; 182 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 183 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 184 scope6_init(); 185 addrsel_policy_init(); 186 nd6_init(); 187 frag6_init(); 188 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 189 } 190 191 static void 192 ip6_init2(void *dummy) 193 { 194 195 /* nd6_timer_init */ 196 callout_init(&nd6_timer_ch, 0); 197 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 198 199 /* timer for regeneranation of temporary addresses randomize ID */ 200 callout_init(&in6_tmpaddrtimer_ch, 0); 201 callout_reset(&in6_tmpaddrtimer_ch, 202 (ip6_temp_preferred_lifetime - ip6_desync_factor - 203 ip6_temp_regen_advance) * hz, 204 in6_tmpaddrtimer, NULL); 205 } 206 207 /* cheat */ 208 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 209 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 210 211 extern struct route_in6 ip6_forward_rt; 212 213 void 214 ip6_input(struct mbuf *m) 215 { 216 struct ip6_hdr *ip6; 217 int off = sizeof(struct ip6_hdr), nest; 218 u_int32_t plen; 219 u_int32_t rtalert = ~0; 220 int nxt, ours = 0; 221 struct ifnet *deliverifp = NULL; 222 struct in6_addr odst; 223 int srcrt = 0; 224 225 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); 411 412 passin: 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 */ 784 static struct ip6aux * 785 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 786 { 787 struct ip6aux *ip6a; 788 789 ip6a = ip6_addaux(m); 790 if (ip6a) 791 ip6a->ip6a_dstia6 = ia6; 792 return ip6a; /* NULL if failed to set */ 793 } 794 795 struct in6_ifaddr * 796 ip6_getdstifaddr(struct mbuf *m) 797 { 798 struct ip6aux *ip6a; 799 800 ip6a = ip6_findaux(m); 801 if (ip6a) 802 return ip6a->ip6a_dstia6; 803 else 804 return NULL; 805 } 806 807 /* 808 * Hop-by-Hop options header processing. If a valid jumbo payload option is 809 * included, the real payload length will be stored in plenp. 810 * 811 * rtalertp - XXX: should be stored more smart way 812 */ 813 static int 814 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 815 struct mbuf **mp, int *offp) 816 { 817 struct mbuf *m = *mp; 818 int off = *offp, hbhlen; 819 struct ip6_hbh *hbh; 820 u_int8_t *opt; 821 822 /* validation of the length of the header */ 823 #ifndef PULLDOWN_TEST 824 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 825 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 826 hbhlen = (hbh->ip6h_len + 1) << 3; 827 828 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 829 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 830 #else 831 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 832 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 833 if (hbh == NULL) { 834 ip6stat.ip6s_tooshort++; 835 return -1; 836 } 837 hbhlen = (hbh->ip6h_len + 1) << 3; 838 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 839 hbhlen); 840 if (hbh == NULL) { 841 ip6stat.ip6s_tooshort++; 842 return -1; 843 } 844 #endif 845 off += hbhlen; 846 hbhlen -= sizeof(struct ip6_hbh); 847 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 848 849 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 850 hbhlen, rtalertp, plenp) < 0) 851 return (-1); 852 853 *offp = off; 854 *mp = m; 855 return (0); 856 } 857 858 /* 859 * Search header for all Hop-by-hop options and process each option. 860 * This function is separate from ip6_hopopts_input() in order to 861 * handle a case where the sending node itself process its hop-by-hop 862 * options header. In such a case, the function is called from ip6_output(). 863 * 864 * The function assumes that hbh header is located right after the IPv6 header 865 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 866 * opthead + hbhlen is located in continuous memory region. 867 */ 868 int 869 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 870 u_int32_t *rtalertp, u_int32_t *plenp) 871 { 872 struct ip6_hdr *ip6; 873 int optlen = 0; 874 u_int8_t *opt = opthead; 875 u_int16_t rtalert_val; 876 u_int32_t jumboplen; 877 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 878 879 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 880 switch (*opt) { 881 case IP6OPT_PAD1: 882 optlen = 1; 883 break; 884 case IP6OPT_PADN: 885 if (hbhlen < IP6OPT_MINLEN) { 886 ip6stat.ip6s_toosmall++; 887 goto bad; 888 } 889 optlen = *(opt + 1) + 2; 890 break; 891 case IP6OPT_ROUTER_ALERT: 892 /* XXX may need check for alignment */ 893 if (hbhlen < IP6OPT_RTALERT_LEN) { 894 ip6stat.ip6s_toosmall++; 895 goto bad; 896 } 897 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 898 /* XXX stat */ 899 icmp6_error(m, ICMP6_PARAM_PROB, 900 ICMP6_PARAMPROB_HEADER, 901 erroff + opt + 1 - opthead); 902 return (-1); 903 } 904 optlen = IP6OPT_RTALERT_LEN; 905 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 906 *rtalertp = ntohs(rtalert_val); 907 break; 908 case IP6OPT_JUMBO: 909 /* XXX may need check for alignment */ 910 if (hbhlen < IP6OPT_JUMBO_LEN) { 911 ip6stat.ip6s_toosmall++; 912 goto bad; 913 } 914 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 915 /* XXX stat */ 916 icmp6_error(m, ICMP6_PARAM_PROB, 917 ICMP6_PARAMPROB_HEADER, 918 erroff + opt + 1 - opthead); 919 return (-1); 920 } 921 optlen = IP6OPT_JUMBO_LEN; 922 923 /* 924 * IPv6 packets that have non 0 payload length 925 * must not contain a jumbo payload option. 926 */ 927 ip6 = mtod(m, struct ip6_hdr *); 928 if (ip6->ip6_plen) { 929 ip6stat.ip6s_badoptions++; 930 icmp6_error(m, ICMP6_PARAM_PROB, 931 ICMP6_PARAMPROB_HEADER, 932 erroff + opt - opthead); 933 return (-1); 934 } 935 936 /* 937 * We may see jumbolen in unaligned location, so 938 * we'd need to perform bcopy(). 939 */ 940 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 941 jumboplen = (u_int32_t)htonl(jumboplen); 942 943 #if 1 944 /* 945 * if there are multiple jumbo payload options, 946 * *plenp will be non-zero and the packet will be 947 * rejected. 948 * the behavior may need some debate in ipngwg - 949 * multiple options does not make sense, however, 950 * there's no explicit mention in specification. 951 */ 952 if (*plenp != 0) { 953 ip6stat.ip6s_badoptions++; 954 icmp6_error(m, ICMP6_PARAM_PROB, 955 ICMP6_PARAMPROB_HEADER, 956 erroff + opt + 2 - opthead); 957 return (-1); 958 } 959 #endif 960 961 /* 962 * jumbo payload length must be larger than 65535. 963 */ 964 if (jumboplen <= IPV6_MAXPACKET) { 965 ip6stat.ip6s_badoptions++; 966 icmp6_error(m, ICMP6_PARAM_PROB, 967 ICMP6_PARAMPROB_HEADER, 968 erroff + opt + 2 - opthead); 969 return (-1); 970 } 971 *plenp = jumboplen; 972 973 break; 974 default: /* unknown option */ 975 if (hbhlen < IP6OPT_MINLEN) { 976 ip6stat.ip6s_toosmall++; 977 goto bad; 978 } 979 optlen = ip6_unknown_opt(opt, m, 980 erroff + opt - opthead); 981 if (optlen == -1) 982 return (-1); 983 optlen += 2; 984 break; 985 } 986 } 987 988 return (0); 989 990 bad: 991 m_freem(m); 992 return (-1); 993 } 994 995 /* 996 * Unknown option processing. 997 * The third argument `off' is the offset from the IPv6 header to the option, 998 * which is necessary if the IPv6 header the and option header and IPv6 header 999 * is not continuous in order to return an ICMPv6 error. 1000 */ 1001 int 1002 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1003 { 1004 struct ip6_hdr *ip6; 1005 1006 switch (IP6OPT_TYPE(*optp)) { 1007 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1008 return ((int)*(optp + 1)); 1009 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1010 m_freem(m); 1011 return (-1); 1012 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1013 ip6stat.ip6s_badoptions++; 1014 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1015 return (-1); 1016 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1017 ip6stat.ip6s_badoptions++; 1018 ip6 = mtod(m, struct ip6_hdr *); 1019 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1020 (m->m_flags & (M_BCAST|M_MCAST))) 1021 m_freem(m); 1022 else 1023 icmp6_error(m, ICMP6_PARAM_PROB, 1024 ICMP6_PARAMPROB_OPTION, off); 1025 return (-1); 1026 } 1027 1028 m_freem(m); /* XXX: NOTREACHED */ 1029 return (-1); 1030 } 1031 1032 /* 1033 * Create the "control" list for this pcb. 1034 * The function will not modify mbuf chain at all. 1035 * 1036 * with KAME mbuf chain restriction: 1037 * The routine will be called from upper layer handlers like tcp6_input(). 1038 * Thus the routine assumes that the caller (tcp6_input) have already 1039 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1040 * very first mbuf on the mbuf chain. 1041 */ 1042 void 1043 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1044 { 1045 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1046 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1047 1048 #ifdef SO_TIMESTAMP 1049 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1050 struct timeval tv; 1051 1052 microtime(&tv); 1053 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1054 SCM_TIMESTAMP, SOL_SOCKET); 1055 if (*mp) 1056 mp = &(*mp)->m_next; 1057 } 1058 #endif 1059 1060 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1061 return; 1062 1063 /* RFC 2292 sec. 5 */ 1064 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1065 struct in6_pktinfo pi6; 1066 1067 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1068 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1069 pi6.ipi6_ifindex = 1070 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1071 1072 *mp = sbcreatecontrol((caddr_t) &pi6, 1073 sizeof(struct in6_pktinfo), 1074 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1075 if (*mp) 1076 mp = &(*mp)->m_next; 1077 } 1078 1079 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1080 int hlim = ip6->ip6_hlim & 0xff; 1081 1082 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1083 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1084 if (*mp) 1085 mp = &(*mp)->m_next; 1086 } 1087 1088 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1089 u_int32_t flowinfo; 1090 int tclass; 1091 1092 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1093 flowinfo >>= 20; 1094 1095 tclass = flowinfo & 0xff; 1096 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1097 IPV6_TCLASS, IPPROTO_IPV6); 1098 if (*mp) 1099 mp = &(*mp)->m_next; 1100 } 1101 1102 /* 1103 * IPV6_HOPOPTS socket option. Recall that we required super-user 1104 * privilege for the option (see ip6_ctloutput), but it might be too 1105 * strict, since there might be some hop-by-hop options which can be 1106 * returned to normal user. 1107 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1108 */ 1109 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1110 /* 1111 * Check if a hop-by-hop options header is contatined in the 1112 * received packet, and if so, store the options as ancillary 1113 * data. Note that a hop-by-hop options header must be 1114 * just after the IPv6 header, which is assured through the 1115 * IPv6 input processing. 1116 */ 1117 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1118 struct ip6_hbh *hbh; 1119 int hbhlen = 0; 1120 #ifdef PULLDOWN_TEST 1121 struct mbuf *ext; 1122 #endif 1123 1124 #ifndef PULLDOWN_TEST 1125 hbh = (struct ip6_hbh *)(ip6 + 1); 1126 hbhlen = (hbh->ip6h_len + 1) << 3; 1127 #else 1128 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1129 ip6->ip6_nxt); 1130 if (ext == NULL) { 1131 ip6stat.ip6s_tooshort++; 1132 return; 1133 } 1134 hbh = mtod(ext, struct ip6_hbh *); 1135 hbhlen = (hbh->ip6h_len + 1) << 3; 1136 if (hbhlen != ext->m_len) { 1137 m_freem(ext); 1138 ip6stat.ip6s_tooshort++; 1139 return; 1140 } 1141 #endif 1142 1143 /* 1144 * XXX: We copy the whole header even if a 1145 * jumbo payload option is included, the option which 1146 * is to be removed before returning according to 1147 * RFC2292. 1148 * Note: this constraint is removed in RFC3542 1149 */ 1150 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1151 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1152 IPPROTO_IPV6); 1153 if (*mp) 1154 mp = &(*mp)->m_next; 1155 #ifdef PULLDOWN_TEST 1156 m_freem(ext); 1157 #endif 1158 } 1159 } 1160 1161 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1162 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1163 1164 /* 1165 * Search for destination options headers or routing 1166 * header(s) through the header chain, and stores each 1167 * header as ancillary data. 1168 * Note that the order of the headers remains in 1169 * the chain of ancillary data. 1170 */ 1171 while (1) { /* is explicit loop prevention necessary? */ 1172 struct ip6_ext *ip6e = NULL; 1173 int elen; 1174 #ifdef PULLDOWN_TEST 1175 struct mbuf *ext = NULL; 1176 #endif 1177 1178 /* 1179 * if it is not an extension header, don't try to 1180 * pull it from the chain. 1181 */ 1182 switch (nxt) { 1183 case IPPROTO_DSTOPTS: 1184 case IPPROTO_ROUTING: 1185 case IPPROTO_HOPOPTS: 1186 case IPPROTO_AH: /* is it possible? */ 1187 break; 1188 default: 1189 goto loopend; 1190 } 1191 1192 #ifndef PULLDOWN_TEST 1193 if (off + sizeof(*ip6e) > m->m_len) 1194 goto loopend; 1195 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1196 if (nxt == IPPROTO_AH) 1197 elen = (ip6e->ip6e_len + 2) << 2; 1198 else 1199 elen = (ip6e->ip6e_len + 1) << 3; 1200 if (off + elen > m->m_len) 1201 goto loopend; 1202 #else 1203 ext = ip6_pullexthdr(m, off, nxt); 1204 if (ext == NULL) { 1205 ip6stat.ip6s_tooshort++; 1206 return; 1207 } 1208 ip6e = mtod(ext, struct ip6_ext *); 1209 if (nxt == IPPROTO_AH) 1210 elen = (ip6e->ip6e_len + 2) << 2; 1211 else 1212 elen = (ip6e->ip6e_len + 1) << 3; 1213 if (elen != ext->m_len) { 1214 m_freem(ext); 1215 ip6stat.ip6s_tooshort++; 1216 return; 1217 } 1218 #endif 1219 1220 switch (nxt) { 1221 case IPPROTO_DSTOPTS: 1222 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1223 break; 1224 1225 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1226 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1227 IPPROTO_IPV6); 1228 if (*mp) 1229 mp = &(*mp)->m_next; 1230 break; 1231 case IPPROTO_ROUTING: 1232 if (!in6p->in6p_flags & IN6P_RTHDR) 1233 break; 1234 1235 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1236 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1237 IPPROTO_IPV6); 1238 if (*mp) 1239 mp = &(*mp)->m_next; 1240 break; 1241 case IPPROTO_HOPOPTS: 1242 case IPPROTO_AH: /* is it possible? */ 1243 break; 1244 1245 default: 1246 /* 1247 * other cases have been filtered in the above. 1248 * none will visit this case. here we supply 1249 * the code just in case (nxt overwritten or 1250 * other cases). 1251 */ 1252 #ifdef PULLDOWN_TEST 1253 m_freem(ext); 1254 #endif 1255 goto loopend; 1256 1257 } 1258 1259 /* proceed with the next header. */ 1260 off += elen; 1261 nxt = ip6e->ip6e_nxt; 1262 ip6e = NULL; 1263 #ifdef PULLDOWN_TEST 1264 m_freem(ext); 1265 ext = NULL; 1266 #endif 1267 } 1268 loopend: 1269 ; 1270 } 1271 1272 #undef IS2292 1273 } 1274 1275 void 1276 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1277 { 1278 struct socket *so; 1279 struct mbuf *m_mtu; 1280 struct ip6_mtuinfo mtuctl; 1281 1282 so = in6p->inp_socket; 1283 1284 if (mtu == NULL) 1285 return; 1286 1287 #ifdef DIAGNOSTIC 1288 if (so == NULL) /* I believe this is impossible */ 1289 panic("ip6_notify_pmtu: socket is NULL"); 1290 #endif 1291 1292 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1293 mtuctl.ip6m_mtu = *mtu; 1294 mtuctl.ip6m_addr = *dst; 1295 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1296 return; 1297 1298 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1299 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1300 return; 1301 1302 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1303 == 0) { 1304 m_freem(m_mtu); 1305 /* XXX: should count statistics */ 1306 } else 1307 sorwakeup(so); 1308 1309 return; 1310 } 1311 1312 #ifdef PULLDOWN_TEST 1313 /* 1314 * pull single extension header from mbuf chain. returns single mbuf that 1315 * contains the result, or NULL on error. 1316 */ 1317 static struct mbuf * 1318 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1319 { 1320 struct ip6_ext ip6e; 1321 size_t elen; 1322 struct mbuf *n; 1323 1324 #ifdef DIAGNOSTIC 1325 switch (nxt) { 1326 case IPPROTO_DSTOPTS: 1327 case IPPROTO_ROUTING: 1328 case IPPROTO_HOPOPTS: 1329 case IPPROTO_AH: /* is it possible? */ 1330 break; 1331 default: 1332 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1333 } 1334 #endif 1335 1336 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1337 if (nxt == IPPROTO_AH) 1338 elen = (ip6e.ip6e_len + 2) << 2; 1339 else 1340 elen = (ip6e.ip6e_len + 1) << 3; 1341 1342 MGET(n, M_DONTWAIT, MT_DATA); 1343 if (n && elen >= MLEN) { 1344 MCLGET(n, M_DONTWAIT); 1345 if ((n->m_flags & M_EXT) == 0) { 1346 m_free(n); 1347 n = NULL; 1348 } 1349 } 1350 if (!n) 1351 return NULL; 1352 1353 n->m_len = 0; 1354 if (elen >= M_TRAILINGSPACE(n)) { 1355 m_free(n); 1356 return NULL; 1357 } 1358 1359 m_copydata(m, off, elen, mtod(n, caddr_t)); 1360 n->m_len = elen; 1361 return n; 1362 } 1363 #endif 1364 1365 /* 1366 * Get pointer to the previous header followed by the header 1367 * currently processed. 1368 * XXX: This function supposes that 1369 * M includes all headers, 1370 * the next header field and the header length field of each header 1371 * are valid, and 1372 * the sum of each header length equals to OFF. 1373 * Because of these assumptions, this function must be called very 1374 * carefully. Moreover, it will not be used in the near future when 1375 * we develop `neater' mechanism to process extension headers. 1376 */ 1377 char * 1378 ip6_get_prevhdr(struct mbuf *m, int off) 1379 { 1380 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1381 1382 if (off == sizeof(struct ip6_hdr)) 1383 return (&ip6->ip6_nxt); 1384 else { 1385 int len, nxt; 1386 struct ip6_ext *ip6e = NULL; 1387 1388 nxt = ip6->ip6_nxt; 1389 len = sizeof(struct ip6_hdr); 1390 while (len < off) { 1391 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1392 1393 switch (nxt) { 1394 case IPPROTO_FRAGMENT: 1395 len += sizeof(struct ip6_frag); 1396 break; 1397 case IPPROTO_AH: 1398 len += (ip6e->ip6e_len + 2) << 2; 1399 break; 1400 default: 1401 len += (ip6e->ip6e_len + 1) << 3; 1402 break; 1403 } 1404 nxt = ip6e->ip6e_nxt; 1405 } 1406 if (ip6e) 1407 return (&ip6e->ip6e_nxt); 1408 else 1409 return NULL; 1410 } 1411 } 1412 1413 /* 1414 * get next header offset. m will be retained. 1415 */ 1416 int 1417 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1418 { 1419 struct ip6_hdr ip6; 1420 struct ip6_ext ip6e; 1421 struct ip6_frag fh; 1422 1423 /* just in case */ 1424 if (m == NULL) 1425 panic("ip6_nexthdr: m == NULL"); 1426 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1427 return -1; 1428 1429 switch (proto) { 1430 case IPPROTO_IPV6: 1431 if (m->m_pkthdr.len < off + sizeof(ip6)) 1432 return -1; 1433 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1434 if (nxtp) 1435 *nxtp = ip6.ip6_nxt; 1436 off += sizeof(ip6); 1437 return off; 1438 1439 case IPPROTO_FRAGMENT: 1440 /* 1441 * terminate parsing if it is not the first fragment, 1442 * it does not make sense to parse through it. 1443 */ 1444 if (m->m_pkthdr.len < off + sizeof(fh)) 1445 return -1; 1446 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1447 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1448 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1449 return -1; 1450 if (nxtp) 1451 *nxtp = fh.ip6f_nxt; 1452 off += sizeof(struct ip6_frag); 1453 return off; 1454 1455 case IPPROTO_AH: 1456 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1457 return -1; 1458 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1459 if (nxtp) 1460 *nxtp = ip6e.ip6e_nxt; 1461 off += (ip6e.ip6e_len + 2) << 2; 1462 return off; 1463 1464 case IPPROTO_HOPOPTS: 1465 case IPPROTO_ROUTING: 1466 case IPPROTO_DSTOPTS: 1467 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1468 return -1; 1469 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1470 if (nxtp) 1471 *nxtp = ip6e.ip6e_nxt; 1472 off += (ip6e.ip6e_len + 1) << 3; 1473 return off; 1474 1475 case IPPROTO_NONE: 1476 case IPPROTO_ESP: 1477 case IPPROTO_IPCOMP: 1478 /* give up */ 1479 return -1; 1480 1481 default: 1482 return -1; 1483 } 1484 1485 return -1; 1486 } 1487 1488 /* 1489 * get offset for the last header in the chain. m will be kept untainted. 1490 */ 1491 int 1492 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1493 { 1494 int newoff; 1495 int nxt; 1496 1497 if (!nxtp) { 1498 nxt = -1; 1499 nxtp = &nxt; 1500 } 1501 while (1) { 1502 newoff = ip6_nexthdr(m, off, proto, nxtp); 1503 if (newoff < 0) 1504 return off; 1505 else if (newoff < off) 1506 return -1; /* invalid */ 1507 else if (newoff == off) 1508 return newoff; 1509 1510 off = newoff; 1511 proto = *nxtp; 1512 } 1513 } 1514 1515 struct ip6aux * 1516 ip6_addaux(struct mbuf *m) 1517 { 1518 struct m_tag *mtag; 1519 1520 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1521 if (!mtag) { 1522 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1523 M_NOWAIT); 1524 if (mtag) { 1525 m_tag_prepend(m, mtag); 1526 bzero(mtag + 1, sizeof(struct ip6aux)); 1527 } 1528 } 1529 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1530 } 1531 1532 struct ip6aux * 1533 ip6_findaux(struct mbuf *m) 1534 { 1535 struct m_tag *mtag; 1536 1537 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1538 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1539 } 1540 1541 void 1542 ip6_delaux(struct mbuf *m) 1543 { 1544 struct m_tag *mtag; 1545 1546 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1547 if (mtag) 1548 m_tag_delete(m, mtag); 1549 } 1550 1551 /* 1552 * System control for IP6 1553 */ 1554 1555 u_char inet6ctlerrmap[PRC_NCMDS] = { 1556 0, 0, 0, 0, 1557 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1558 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1559 EMSGSIZE, EHOSTUNREACH, 0, 0, 1560 0, 0, 0, 0, 1561 ENOPROTOOPT 1562 }; 1563