1 /* $FreeBSD$ */ 2 /* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 3 4 /*- 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /*- 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 4. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include "opt_inet.h" 65 #include "opt_inet6.h" 66 #include "opt_ipsec.h" 67 68 #include <sys/param.h> 69 #include <sys/systm.h> 70 #include <sys/malloc.h> 71 #include <sys/mbuf.h> 72 #include <sys/proc.h> 73 #include <sys/domain.h> 74 #include <sys/protosw.h> 75 #include <sys/socket.h> 76 #include <sys/socketvar.h> 77 #include <sys/errno.h> 78 #include <sys/time.h> 79 #include <sys/kernel.h> 80 #include <sys/syslog.h> 81 82 #include <net/if.h> 83 #include <net/if_types.h> 84 #include <net/if_dl.h> 85 #include <net/route.h> 86 #include <net/netisr.h> 87 #include <net/pfil.h> 88 89 #include <netinet/in.h> 90 #include <netinet/in_systm.h> 91 #ifdef INET 92 #include <netinet/ip.h> 93 #include <netinet/ip_icmp.h> 94 #endif /* INET */ 95 #include <netinet/ip6.h> 96 #include <netinet6/in6_var.h> 97 #include <netinet6/ip6_var.h> 98 #include <netinet/in_pcb.h> 99 #include <netinet/icmp6.h> 100 #include <netinet6/scope6_var.h> 101 #include <netinet6/in6_ifattach.h> 102 #include <netinet6/nd6.h> 103 104 #ifdef IPSEC 105 #include <netinet6/ipsec.h> 106 #ifdef INET6 107 #include <netinet6/ipsec6.h> 108 #endif 109 #endif 110 111 #ifdef FAST_IPSEC 112 #include <netipsec/ipsec.h> 113 #include <netipsec/ipsec6.h> 114 #define IPSEC 115 #endif /* FAST_IPSEC */ 116 117 #include <netinet6/ip6protosw.h> 118 119 extern struct domain inet6domain; 120 121 u_char ip6_protox[IPPROTO_MAX]; 122 static struct ifqueue ip6intrq; 123 static int ip6qmaxlen = IFQ_MAXLEN; 124 struct in6_ifaddr *in6_ifaddr; 125 126 extern struct callout in6_tmpaddrtimer_ch; 127 128 int ip6_forward_srcrt; /* XXX */ 129 int ip6_sourcecheck; /* XXX */ 130 int ip6_sourcecheck_interval; /* XXX */ 131 132 int ip6_ours_check_algorithm; 133 134 struct pfil_head inet6_pfil_hook; 135 136 struct ip6stat ip6stat; 137 138 static void ip6_init2 __P((void *)); 139 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 140 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 141 #ifdef PULLDOWN_TEST 142 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 143 #endif 144 145 /* 146 * IP6 initialization: fill in IP6 protocol switch table. 147 * All protocols not implemented in kernel go to raw IP6 protocol handler. 148 */ 149 void 150 ip6_init() 151 { 152 struct ip6protosw *pr; 153 int i; 154 155 #ifdef DIAGNOSTIC 156 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 157 panic("sizeof(protosw) != sizeof(ip6protosw)"); 158 #endif 159 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 160 if (pr == 0) 161 panic("ip6_init"); 162 163 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 164 for (i = 0; i < IPPROTO_MAX; i++) 165 ip6_protox[i] = pr - inet6sw; 166 /* 167 * Cycle through IP protocols and put them into the appropriate place 168 * in ip6_protox[]. 169 */ 170 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 171 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 172 if (pr->pr_domain->dom_family == PF_INET6 && 173 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 174 /* Be careful to only index valid IP protocols. */ 175 if (pr->pr_protocol < IPPROTO_MAX) 176 ip6_protox[pr->pr_protocol] = pr - inet6sw; 177 } 178 179 /* Initialize packet filter hooks. */ 180 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 181 inet6_pfil_hook.ph_af = AF_INET6; 182 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 183 printf("%s: WARNING: unable to register pfil hook, " 184 "error %d\n", __func__, i); 185 186 ip6intrq.ifq_maxlen = ip6qmaxlen; 187 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 188 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 189 scope6_init(); 190 addrsel_policy_init(); 191 nd6_init(); 192 frag6_init(); 193 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 194 } 195 196 static void 197 ip6_init2(dummy) 198 void *dummy; 199 { 200 201 /* nd6_timer_init */ 202 callout_init(&nd6_timer_ch, 0); 203 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 204 205 /* timer for regeneranation of temporary addresses randomize ID */ 206 callout_init(&in6_tmpaddrtimer_ch, 0); 207 callout_reset(&in6_tmpaddrtimer_ch, 208 (ip6_temp_preferred_lifetime - ip6_desync_factor - 209 ip6_temp_regen_advance) * hz, 210 in6_tmpaddrtimer, NULL); 211 } 212 213 /* cheat */ 214 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 215 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 216 217 extern struct route_in6 ip6_forward_rt; 218 219 void 220 ip6_input(m) 221 struct mbuf *m; 222 { 223 struct ip6_hdr *ip6; 224 int off = sizeof(struct ip6_hdr), nest; 225 u_int32_t plen; 226 u_int32_t rtalert = ~0; 227 int nxt, ours = 0; 228 struct ifnet *deliverifp = NULL; 229 struct in6_addr odst; 230 int srcrt = 0; 231 232 GIANT_REQUIRED; /* XXX for now */ 233 #ifdef IPSEC 234 /* 235 * should the inner packet be considered authentic? 236 * see comment in ah4_input(). 237 */ 238 if (m) { 239 m->m_flags &= ~M_AUTHIPHDR; 240 m->m_flags &= ~M_AUTHIPDGM; 241 } 242 #endif 243 244 /* 245 * make sure we don't have onion peering information into m_tag. 246 */ 247 ip6_delaux(m); 248 249 /* 250 * mbuf statistics 251 */ 252 if (m->m_flags & M_EXT) { 253 if (m->m_next) 254 ip6stat.ip6s_mext2m++; 255 else 256 ip6stat.ip6s_mext1++; 257 } else { 258 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 259 if (m->m_next) { 260 if (m->m_flags & M_LOOP) { 261 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 262 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 263 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 264 else 265 ip6stat.ip6s_m2m[0]++; 266 } else 267 ip6stat.ip6s_m1++; 268 #undef M2MMAX 269 } 270 271 /* drop the packet if IPv6 operation is disabled on the IF */ 272 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 273 m_freem(m); 274 return; 275 } 276 277 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 278 ip6stat.ip6s_total++; 279 280 #ifndef PULLDOWN_TEST 281 /* 282 * L2 bridge code and some other code can return mbuf chain 283 * that does not conform to KAME requirement. too bad. 284 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 285 */ 286 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 287 struct mbuf *n; 288 289 MGETHDR(n, M_DONTWAIT, MT_HEADER); 290 if (n) 291 M_MOVE_PKTHDR(n, m); 292 if (n && n->m_pkthdr.len > MHLEN) { 293 MCLGET(n, M_DONTWAIT); 294 if ((n->m_flags & M_EXT) == 0) { 295 m_freem(n); 296 n = NULL; 297 } 298 } 299 if (n == NULL) { 300 m_freem(m); 301 return; /* ENOBUFS */ 302 } 303 304 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 305 n->m_len = n->m_pkthdr.len; 306 m_freem(m); 307 m = n; 308 } 309 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 310 #endif 311 312 if (m->m_len < sizeof(struct ip6_hdr)) { 313 struct ifnet *inifp; 314 inifp = m->m_pkthdr.rcvif; 315 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 316 ip6stat.ip6s_toosmall++; 317 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 318 return; 319 } 320 } 321 322 ip6 = mtod(m, struct ip6_hdr *); 323 324 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 325 ip6stat.ip6s_badvers++; 326 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 327 goto bad; 328 } 329 330 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 331 332 /* 333 * Check against address spoofing/corruption. 334 */ 335 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 336 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 337 /* 338 * XXX: "badscope" is not very suitable for a multicast source. 339 */ 340 ip6stat.ip6s_badscope++; 341 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 342 goto bad; 343 } 344 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 345 !(m->m_flags & M_LOOP)) { 346 /* 347 * In this case, the packet should come from the loopback 348 * interface. However, we cannot just check the if_flags, 349 * because ip6_mloopback() passes the "actual" interface 350 * as the outgoing/incoming interface. 351 */ 352 ip6stat.ip6s_badscope++; 353 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 354 goto bad; 355 } 356 357 #ifdef ALTQ 358 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 359 /* packet is dropped by traffic conditioner */ 360 return; 361 } 362 #endif 363 /* 364 * The following check is not documented in specs. A malicious 365 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 366 * and bypass security checks (act as if it was from 127.0.0.1 by using 367 * IPv6 src ::ffff:127.0.0.1). Be cautious. 368 * 369 * This check chokes if we are in an SIIT cloud. As none of BSDs 370 * support IPv4-less kernel compilation, we cannot support SIIT 371 * environment at all. So, it makes more sense for us to reject any 372 * malicious packets for non-SIIT environment, than try to do a 373 * partial support for SIIT environment. 374 */ 375 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 376 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 377 ip6stat.ip6s_badscope++; 378 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 379 goto bad; 380 } 381 #if 0 382 /* 383 * Reject packets with IPv4 compatible addresses (auto tunnel). 384 * 385 * The code forbids auto tunnel relay case in RFC1933 (the check is 386 * stronger than RFC1933). We may want to re-enable it if mech-xx 387 * is revised to forbid relaying case. 388 */ 389 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 390 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 391 ip6stat.ip6s_badscope++; 392 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 393 goto bad; 394 } 395 #endif 396 397 /* 398 * Run through list of hooks for input packets. 399 * 400 * NB: Beware of the destination address changing 401 * (e.g. by NAT rewriting). When this happens, 402 * tell ip6_forward to do the right thing. 403 */ 404 odst = ip6->ip6_dst; 405 406 /* Jump over all PFIL processing if hooks are not active. */ 407 if (!PFIL_HOOKED(&inet6_pfil_hook)) 408 goto passin; 409 410 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 411 return; 412 if (m == NULL) /* consumed by filter */ 413 return; 414 ip6 = mtod(m, struct ip6_hdr *); 415 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 416 417 passin: 418 /* 419 * Disambiguate address scope zones (if there is ambiguity). 420 * We first make sure that the original source or destination address 421 * is not in our internal form for scoped addresses. Such addresses 422 * are not necessarily invalid spec-wise, but we cannot accept them due 423 * to the usage conflict. 424 * in6_setscope() then also checks and rejects the cases where src or 425 * dst are the loopback address and the receiving interface 426 * is not loopback. 427 */ 428 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 429 ip6stat.ip6s_badscope++; /* XXX */ 430 goto bad; 431 } 432 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 433 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 434 ip6stat.ip6s_badscope++; 435 goto bad; 436 } 437 438 /* 439 * Multicast check 440 */ 441 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 442 struct in6_multi *in6m = 0; 443 444 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 445 /* 446 * See if we belong to the destination multicast group on the 447 * arrival interface. 448 */ 449 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 450 if (in6m) 451 ours = 1; 452 else if (!ip6_mrouter) { 453 ip6stat.ip6s_notmember++; 454 ip6stat.ip6s_cantforward++; 455 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 456 goto bad; 457 } 458 deliverifp = m->m_pkthdr.rcvif; 459 goto hbhcheck; 460 } 461 462 /* 463 * Unicast check 464 */ 465 if (ip6_forward_rt.ro_rt != NULL && 466 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 467 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 468 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 469 ip6stat.ip6s_forward_cachehit++; 470 else { 471 struct sockaddr_in6 *dst6; 472 473 if (ip6_forward_rt.ro_rt) { 474 /* route is down or destination is different */ 475 ip6stat.ip6s_forward_cachemiss++; 476 RTFREE(ip6_forward_rt.ro_rt); 477 ip6_forward_rt.ro_rt = 0; 478 } 479 480 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 481 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 482 dst6->sin6_len = sizeof(struct sockaddr_in6); 483 dst6->sin6_family = AF_INET6; 484 dst6->sin6_addr = ip6->ip6_dst; 485 486 rtalloc((struct route *)&ip6_forward_rt); 487 } 488 489 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 490 491 /* 492 * Accept the packet if the forwarding interface to the destination 493 * according to the routing table is the loopback interface, 494 * unless the associated route has a gateway. 495 * Note that this approach causes to accept a packet if there is a 496 * route to the loopback interface for the destination of the packet. 497 * But we think it's even useful in some situations, e.g. when using 498 * a special daemon which wants to intercept the packet. 499 * 500 * XXX: some OSes automatically make a cloned route for the destination 501 * of an outgoing packet. If the outgoing interface of the packet 502 * is a loopback one, the kernel would consider the packet to be 503 * accepted, even if we have no such address assinged on the interface. 504 * We check the cloned flag of the route entry to reject such cases, 505 * assuming that route entries for our own addresses are not made by 506 * cloning (it should be true because in6_addloop explicitly installs 507 * the host route). However, we might have to do an explicit check 508 * while it would be less efficient. Or, should we rather install a 509 * reject route for such a case? 510 */ 511 if (ip6_forward_rt.ro_rt && 512 (ip6_forward_rt.ro_rt->rt_flags & 513 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 514 #ifdef RTF_WASCLONED 515 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 516 #endif 517 #ifdef RTF_CLONED 518 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 519 #endif 520 #if 0 521 /* 522 * The check below is redundant since the comparison of 523 * the destination and the key of the rtentry has 524 * already done through looking up the routing table. 525 */ 526 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 527 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 528 #endif 529 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 530 struct in6_ifaddr *ia6 = 531 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 532 533 /* 534 * record address information into m_tag. 535 */ 536 (void)ip6_setdstifaddr(m, ia6); 537 538 /* 539 * packets to a tentative, duplicated, or somehow invalid 540 * address must not be accepted. 541 */ 542 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 543 /* this address is ready */ 544 ours = 1; 545 deliverifp = ia6->ia_ifp; /* correct? */ 546 /* Count the packet in the ip address stats */ 547 ia6->ia_ifa.if_ipackets++; 548 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 549 goto hbhcheck; 550 } else { 551 char ip6bufs[INET6_ADDRSTRLEN]; 552 char ip6bufd[INET6_ADDRSTRLEN]; 553 /* address is not ready, so discard the packet. */ 554 nd6log((LOG_INFO, 555 "ip6_input: packet to an unready address %s->%s\n", 556 ip6_sprintf(ip6bufs, &ip6->ip6_src), 557 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 558 559 goto bad; 560 } 561 } 562 563 /* 564 * FAITH (Firewall Aided Internet Translator) 565 */ 566 if (ip6_keepfaith) { 567 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 568 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 569 /* XXX do we need more sanity checks? */ 570 ours = 1; 571 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 572 goto hbhcheck; 573 } 574 } 575 576 /* 577 * Now there is no reason to process the packet if it's not our own 578 * and we're not a router. 579 */ 580 if (!ip6_forwarding) { 581 ip6stat.ip6s_cantforward++; 582 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 583 goto bad; 584 } 585 586 hbhcheck: 587 /* 588 * record address information into m_tag, if we don't have one yet. 589 * note that we are unable to record it, if the address is not listed 590 * as our interface address (e.g. multicast addresses, addresses 591 * within FAITH prefixes and such). 592 */ 593 if (deliverifp && !ip6_getdstifaddr(m)) { 594 struct in6_ifaddr *ia6; 595 596 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 597 if (ia6) { 598 if (!ip6_setdstifaddr(m, ia6)) { 599 /* 600 * XXX maybe we should drop the packet here, 601 * as we could not provide enough information 602 * to the upper layers. 603 */ 604 } 605 } 606 } 607 608 /* 609 * Process Hop-by-Hop options header if it's contained. 610 * m may be modified in ip6_hopopts_input(). 611 * If a JumboPayload option is included, plen will also be modified. 612 */ 613 plen = (u_int32_t)ntohs(ip6->ip6_plen); 614 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 615 struct ip6_hbh *hbh; 616 617 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 618 #if 0 /*touches NULL pointer*/ 619 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 620 #endif 621 return; /* m have already been freed */ 622 } 623 624 /* adjust pointer */ 625 ip6 = mtod(m, struct ip6_hdr *); 626 627 /* 628 * if the payload length field is 0 and the next header field 629 * indicates Hop-by-Hop Options header, then a Jumbo Payload 630 * option MUST be included. 631 */ 632 if (ip6->ip6_plen == 0 && plen == 0) { 633 /* 634 * Note that if a valid jumbo payload option is 635 * contained, ip6_hopopts_input() must set a valid 636 * (non-zero) payload length to the variable plen. 637 */ 638 ip6stat.ip6s_badoptions++; 639 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 640 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 641 icmp6_error(m, ICMP6_PARAM_PROB, 642 ICMP6_PARAMPROB_HEADER, 643 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 644 return; 645 } 646 #ifndef PULLDOWN_TEST 647 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 648 hbh = (struct ip6_hbh *)(ip6 + 1); 649 #else 650 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 651 sizeof(struct ip6_hbh)); 652 if (hbh == NULL) { 653 ip6stat.ip6s_tooshort++; 654 return; 655 } 656 #endif 657 nxt = hbh->ip6h_nxt; 658 659 /* 660 * accept the packet if a router alert option is included 661 * and we act as an IPv6 router. 662 */ 663 if (rtalert != ~0 && ip6_forwarding) 664 ours = 1; 665 } else 666 nxt = ip6->ip6_nxt; 667 668 /* 669 * Check that the amount of data in the buffers 670 * is as at least much as the IPv6 header would have us expect. 671 * Trim mbufs if longer than we expect. 672 * Drop packet if shorter than we expect. 673 */ 674 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 675 ip6stat.ip6s_tooshort++; 676 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 677 goto bad; 678 } 679 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 680 if (m->m_len == m->m_pkthdr.len) { 681 m->m_len = sizeof(struct ip6_hdr) + plen; 682 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 683 } else 684 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 685 } 686 687 /* 688 * Forward if desirable. 689 */ 690 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 691 /* 692 * If we are acting as a multicast router, all 693 * incoming multicast packets are passed to the 694 * kernel-level multicast forwarding function. 695 * The packet is returned (relatively) intact; if 696 * ip6_mforward() returns a non-zero value, the packet 697 * must be discarded, else it may be accepted below. 698 */ 699 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 700 ip6stat.ip6s_cantforward++; 701 m_freem(m); 702 return; 703 } 704 if (!ours) { 705 m_freem(m); 706 return; 707 } 708 } else if (!ours) { 709 ip6_forward(m, srcrt); 710 return; 711 } 712 713 ip6 = mtod(m, struct ip6_hdr *); 714 715 /* 716 * Malicious party may be able to use IPv4 mapped addr to confuse 717 * tcp/udp stack and bypass security checks (act as if it was from 718 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 719 * 720 * For SIIT end node behavior, you may want to disable the check. 721 * However, you will become vulnerable to attacks using IPv4 mapped 722 * source. 723 */ 724 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 725 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 726 ip6stat.ip6s_badscope++; 727 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 728 goto bad; 729 } 730 731 /* 732 * Tell launch routine the next header 733 */ 734 ip6stat.ip6s_delivered++; 735 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 736 nest = 0; 737 738 while (nxt != IPPROTO_DONE) { 739 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 740 ip6stat.ip6s_toomanyhdr++; 741 goto bad; 742 } 743 744 /* 745 * protection against faulty packet - there should be 746 * more sanity checks in header chain processing. 747 */ 748 if (m->m_pkthdr.len < off) { 749 ip6stat.ip6s_tooshort++; 750 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 751 goto bad; 752 } 753 754 #ifdef IPSEC 755 /* 756 * enforce IPsec policy checking if we are seeing last header. 757 * note that we do not visit this with protocols with pcb layer 758 * code - like udp/tcp/raw ip. 759 */ 760 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 761 ipsec6_in_reject(m, NULL)) { 762 ipsec6stat.in_polvio++; 763 goto bad; 764 } 765 #endif 766 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 767 } 768 return; 769 bad: 770 m_freem(m); 771 } 772 773 /* 774 * set/grab in6_ifaddr correspond to IPv6 destination address. 775 * XXX backward compatibility wrapper 776 */ 777 static struct ip6aux * 778 ip6_setdstifaddr(m, ia6) 779 struct mbuf *m; 780 struct in6_ifaddr *ia6; 781 { 782 struct ip6aux *ip6a; 783 784 ip6a = ip6_addaux(m); 785 if (ip6a) 786 ip6a->ip6a_dstia6 = ia6; 787 return ip6a; /* NULL if failed to set */ 788 } 789 790 struct in6_ifaddr * 791 ip6_getdstifaddr(m) 792 struct mbuf *m; 793 { 794 struct ip6aux *ip6a; 795 796 ip6a = ip6_findaux(m); 797 if (ip6a) 798 return ip6a->ip6a_dstia6; 799 else 800 return NULL; 801 } 802 803 /* 804 * Hop-by-Hop options header processing. If a valid jumbo payload option is 805 * included, the real payload length will be stored in plenp. 806 */ 807 static int 808 ip6_hopopts_input(plenp, rtalertp, mp, offp) 809 u_int32_t *plenp; 810 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 811 struct mbuf **mp; 812 int *offp; 813 { 814 struct mbuf *m = *mp; 815 int off = *offp, hbhlen; 816 struct ip6_hbh *hbh; 817 u_int8_t *opt; 818 819 /* validation of the length of the header */ 820 #ifndef PULLDOWN_TEST 821 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 822 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 823 hbhlen = (hbh->ip6h_len + 1) << 3; 824 825 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 826 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 827 #else 828 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 829 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 830 if (hbh == NULL) { 831 ip6stat.ip6s_tooshort++; 832 return -1; 833 } 834 hbhlen = (hbh->ip6h_len + 1) << 3; 835 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 836 hbhlen); 837 if (hbh == NULL) { 838 ip6stat.ip6s_tooshort++; 839 return -1; 840 } 841 #endif 842 off += hbhlen; 843 hbhlen -= sizeof(struct ip6_hbh); 844 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 845 846 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 847 hbhlen, rtalertp, plenp) < 0) 848 return (-1); 849 850 *offp = off; 851 *mp = m; 852 return (0); 853 } 854 855 /* 856 * Search header for all Hop-by-hop options and process each option. 857 * This function is separate from ip6_hopopts_input() in order to 858 * handle a case where the sending node itself process its hop-by-hop 859 * options header. In such a case, the function is called from ip6_output(). 860 * 861 * The function assumes that hbh header is located right after the IPv6 header 862 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 863 * opthead + hbhlen is located in continuous memory region. 864 */ 865 int 866 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 867 struct mbuf *m; 868 u_int8_t *opthead; 869 int hbhlen; 870 u_int32_t *rtalertp; 871 u_int32_t *plenp; 872 { 873 struct ip6_hdr *ip6; 874 int optlen = 0; 875 u_int8_t *opt = opthead; 876 u_int16_t rtalert_val; 877 u_int32_t jumboplen; 878 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 879 880 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 881 switch (*opt) { 882 case IP6OPT_PAD1: 883 optlen = 1; 884 break; 885 case IP6OPT_PADN: 886 if (hbhlen < IP6OPT_MINLEN) { 887 ip6stat.ip6s_toosmall++; 888 goto bad; 889 } 890 optlen = *(opt + 1) + 2; 891 break; 892 case IP6OPT_ROUTER_ALERT: 893 /* XXX may need check for alignment */ 894 if (hbhlen < IP6OPT_RTALERT_LEN) { 895 ip6stat.ip6s_toosmall++; 896 goto bad; 897 } 898 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 899 /* XXX stat */ 900 icmp6_error(m, ICMP6_PARAM_PROB, 901 ICMP6_PARAMPROB_HEADER, 902 erroff + opt + 1 - opthead); 903 return (-1); 904 } 905 optlen = IP6OPT_RTALERT_LEN; 906 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 907 *rtalertp = ntohs(rtalert_val); 908 break; 909 case IP6OPT_JUMBO: 910 /* XXX may need check for alignment */ 911 if (hbhlen < IP6OPT_JUMBO_LEN) { 912 ip6stat.ip6s_toosmall++; 913 goto bad; 914 } 915 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 916 /* XXX stat */ 917 icmp6_error(m, ICMP6_PARAM_PROB, 918 ICMP6_PARAMPROB_HEADER, 919 erroff + opt + 1 - opthead); 920 return (-1); 921 } 922 optlen = IP6OPT_JUMBO_LEN; 923 924 /* 925 * IPv6 packets that have non 0 payload length 926 * must not contain a jumbo payload option. 927 */ 928 ip6 = mtod(m, struct ip6_hdr *); 929 if (ip6->ip6_plen) { 930 ip6stat.ip6s_badoptions++; 931 icmp6_error(m, ICMP6_PARAM_PROB, 932 ICMP6_PARAMPROB_HEADER, 933 erroff + opt - opthead); 934 return (-1); 935 } 936 937 /* 938 * We may see jumbolen in unaligned location, so 939 * we'd need to perform bcopy(). 940 */ 941 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 942 jumboplen = (u_int32_t)htonl(jumboplen); 943 944 #if 1 945 /* 946 * if there are multiple jumbo payload options, 947 * *plenp will be non-zero and the packet will be 948 * rejected. 949 * the behavior may need some debate in ipngwg - 950 * multiple options does not make sense, however, 951 * there's no explicit mention in specification. 952 */ 953 if (*plenp != 0) { 954 ip6stat.ip6s_badoptions++; 955 icmp6_error(m, ICMP6_PARAM_PROB, 956 ICMP6_PARAMPROB_HEADER, 957 erroff + opt + 2 - opthead); 958 return (-1); 959 } 960 #endif 961 962 /* 963 * jumbo payload length must be larger than 65535. 964 */ 965 if (jumboplen <= IPV6_MAXPACKET) { 966 ip6stat.ip6s_badoptions++; 967 icmp6_error(m, ICMP6_PARAM_PROB, 968 ICMP6_PARAMPROB_HEADER, 969 erroff + opt + 2 - opthead); 970 return (-1); 971 } 972 *plenp = jumboplen; 973 974 break; 975 default: /* unknown option */ 976 if (hbhlen < IP6OPT_MINLEN) { 977 ip6stat.ip6s_toosmall++; 978 goto bad; 979 } 980 optlen = ip6_unknown_opt(opt, m, 981 erroff + opt - opthead); 982 if (optlen == -1) 983 return (-1); 984 optlen += 2; 985 break; 986 } 987 } 988 989 return (0); 990 991 bad: 992 m_freem(m); 993 return (-1); 994 } 995 996 /* 997 * Unknown option processing. 998 * The third argument `off' is the offset from the IPv6 header to the option, 999 * which is necessary if the IPv6 header the and option header and IPv6 header 1000 * is not continuous in order to return an ICMPv6 error. 1001 */ 1002 int 1003 ip6_unknown_opt(optp, m, off) 1004 u_int8_t *optp; 1005 struct mbuf *m; 1006 int off; 1007 { 1008 struct ip6_hdr *ip6; 1009 1010 switch (IP6OPT_TYPE(*optp)) { 1011 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1012 return ((int)*(optp + 1)); 1013 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1014 m_freem(m); 1015 return (-1); 1016 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1017 ip6stat.ip6s_badoptions++; 1018 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1019 return (-1); 1020 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1021 ip6stat.ip6s_badoptions++; 1022 ip6 = mtod(m, struct ip6_hdr *); 1023 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1024 (m->m_flags & (M_BCAST|M_MCAST))) 1025 m_freem(m); 1026 else 1027 icmp6_error(m, ICMP6_PARAM_PROB, 1028 ICMP6_PARAMPROB_OPTION, off); 1029 return (-1); 1030 } 1031 1032 m_freem(m); /* XXX: NOTREACHED */ 1033 return (-1); 1034 } 1035 1036 /* 1037 * Create the "control" list for this pcb. 1038 * The function will not modify mbuf chain at all. 1039 * 1040 * with KAME mbuf chain restriction: 1041 * The routine will be called from upper layer handlers like tcp6_input(). 1042 * Thus the routine assumes that the caller (tcp6_input) have already 1043 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1044 * very first mbuf on the mbuf chain. 1045 */ 1046 void 1047 ip6_savecontrol(in6p, m, mp) 1048 struct inpcb *in6p; 1049 struct mbuf *m, **mp; 1050 { 1051 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1052 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1053 1054 #ifdef SO_TIMESTAMP 1055 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1056 struct timeval tv; 1057 1058 microtime(&tv); 1059 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1060 SCM_TIMESTAMP, SOL_SOCKET); 1061 if (*mp) 1062 mp = &(*mp)->m_next; 1063 } 1064 #endif 1065 1066 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1067 return; 1068 1069 /* RFC 2292 sec. 5 */ 1070 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1071 struct in6_pktinfo pi6; 1072 1073 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1074 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1075 pi6.ipi6_ifindex = 1076 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1077 1078 *mp = sbcreatecontrol((caddr_t) &pi6, 1079 sizeof(struct in6_pktinfo), 1080 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1081 if (*mp) 1082 mp = &(*mp)->m_next; 1083 } 1084 1085 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1086 int hlim = ip6->ip6_hlim & 0xff; 1087 1088 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1089 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1090 if (*mp) 1091 mp = &(*mp)->m_next; 1092 } 1093 1094 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1095 u_int32_t flowinfo; 1096 int tclass; 1097 1098 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1099 flowinfo >>= 20; 1100 1101 tclass = flowinfo & 0xff; 1102 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1103 IPV6_TCLASS, IPPROTO_IPV6); 1104 if (*mp) 1105 mp = &(*mp)->m_next; 1106 } 1107 1108 /* 1109 * IPV6_HOPOPTS socket option. Recall that we required super-user 1110 * privilege for the option (see ip6_ctloutput), but it might be too 1111 * strict, since there might be some hop-by-hop options which can be 1112 * returned to normal user. 1113 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1114 */ 1115 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1116 /* 1117 * Check if a hop-by-hop options header is contatined in the 1118 * received packet, and if so, store the options as ancillary 1119 * data. Note that a hop-by-hop options header must be 1120 * just after the IPv6 header, which is assured through the 1121 * IPv6 input processing. 1122 */ 1123 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1124 struct ip6_hbh *hbh; 1125 int hbhlen = 0; 1126 #ifdef PULLDOWN_TEST 1127 struct mbuf *ext; 1128 #endif 1129 1130 #ifndef PULLDOWN_TEST 1131 hbh = (struct ip6_hbh *)(ip6 + 1); 1132 hbhlen = (hbh->ip6h_len + 1) << 3; 1133 #else 1134 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1135 ip6->ip6_nxt); 1136 if (ext == NULL) { 1137 ip6stat.ip6s_tooshort++; 1138 return; 1139 } 1140 hbh = mtod(ext, struct ip6_hbh *); 1141 hbhlen = (hbh->ip6h_len + 1) << 3; 1142 if (hbhlen != ext->m_len) { 1143 m_freem(ext); 1144 ip6stat.ip6s_tooshort++; 1145 return; 1146 } 1147 #endif 1148 1149 /* 1150 * XXX: We copy the whole header even if a 1151 * jumbo payload option is included, the option which 1152 * is to be removed before returning according to 1153 * RFC2292. 1154 * Note: this constraint is removed in RFC3542 1155 */ 1156 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1157 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1158 IPPROTO_IPV6); 1159 if (*mp) 1160 mp = &(*mp)->m_next; 1161 #ifdef PULLDOWN_TEST 1162 m_freem(ext); 1163 #endif 1164 } 1165 } 1166 1167 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1168 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1169 1170 /* 1171 * Search for destination options headers or routing 1172 * header(s) through the header chain, and stores each 1173 * header as ancillary data. 1174 * Note that the order of the headers remains in 1175 * the chain of ancillary data. 1176 */ 1177 while (1) { /* is explicit loop prevention necessary? */ 1178 struct ip6_ext *ip6e = NULL; 1179 int elen; 1180 #ifdef PULLDOWN_TEST 1181 struct mbuf *ext = NULL; 1182 #endif 1183 1184 /* 1185 * if it is not an extension header, don't try to 1186 * pull it from the chain. 1187 */ 1188 switch (nxt) { 1189 case IPPROTO_DSTOPTS: 1190 case IPPROTO_ROUTING: 1191 case IPPROTO_HOPOPTS: 1192 case IPPROTO_AH: /* is it possible? */ 1193 break; 1194 default: 1195 goto loopend; 1196 } 1197 1198 #ifndef PULLDOWN_TEST 1199 if (off + sizeof(*ip6e) > m->m_len) 1200 goto loopend; 1201 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1202 if (nxt == IPPROTO_AH) 1203 elen = (ip6e->ip6e_len + 2) << 2; 1204 else 1205 elen = (ip6e->ip6e_len + 1) << 3; 1206 if (off + elen > m->m_len) 1207 goto loopend; 1208 #else 1209 ext = ip6_pullexthdr(m, off, nxt); 1210 if (ext == NULL) { 1211 ip6stat.ip6s_tooshort++; 1212 return; 1213 } 1214 ip6e = mtod(ext, struct ip6_ext *); 1215 if (nxt == IPPROTO_AH) 1216 elen = (ip6e->ip6e_len + 2) << 2; 1217 else 1218 elen = (ip6e->ip6e_len + 1) << 3; 1219 if (elen != ext->m_len) { 1220 m_freem(ext); 1221 ip6stat.ip6s_tooshort++; 1222 return; 1223 } 1224 #endif 1225 1226 switch (nxt) { 1227 case IPPROTO_DSTOPTS: 1228 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1229 break; 1230 1231 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1232 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1233 IPPROTO_IPV6); 1234 if (*mp) 1235 mp = &(*mp)->m_next; 1236 break; 1237 case IPPROTO_ROUTING: 1238 if (!in6p->in6p_flags & IN6P_RTHDR) 1239 break; 1240 1241 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1242 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1243 IPPROTO_IPV6); 1244 if (*mp) 1245 mp = &(*mp)->m_next; 1246 break; 1247 case IPPROTO_HOPOPTS: 1248 case IPPROTO_AH: /* is it possible? */ 1249 break; 1250 1251 default: 1252 /* 1253 * other cases have been filtered in the above. 1254 * none will visit this case. here we supply 1255 * the code just in case (nxt overwritten or 1256 * other cases). 1257 */ 1258 #ifdef PULLDOWN_TEST 1259 m_freem(ext); 1260 #endif 1261 goto loopend; 1262 1263 } 1264 1265 /* proceed with the next header. */ 1266 off += elen; 1267 nxt = ip6e->ip6e_nxt; 1268 ip6e = NULL; 1269 #ifdef PULLDOWN_TEST 1270 m_freem(ext); 1271 ext = NULL; 1272 #endif 1273 } 1274 loopend: 1275 ; 1276 } 1277 1278 #undef IS2292 1279 } 1280 1281 void 1282 ip6_notify_pmtu(in6p, dst, mtu) 1283 struct inpcb *in6p; 1284 struct sockaddr_in6 *dst; 1285 u_int32_t *mtu; 1286 { 1287 struct socket *so; 1288 struct mbuf *m_mtu; 1289 struct ip6_mtuinfo mtuctl; 1290 1291 so = in6p->inp_socket; 1292 1293 if (mtu == NULL) 1294 return; 1295 1296 #ifdef DIAGNOSTIC 1297 if (so == NULL) /* I believe this is impossible */ 1298 panic("ip6_notify_pmtu: socket is NULL"); 1299 #endif 1300 1301 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1302 mtuctl.ip6m_mtu = *mtu; 1303 mtuctl.ip6m_addr = *dst; 1304 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1305 return; 1306 1307 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1308 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1309 return; 1310 1311 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1312 == 0) { 1313 m_freem(m_mtu); 1314 /* XXX: should count statistics */ 1315 } else 1316 sorwakeup(so); 1317 1318 return; 1319 } 1320 1321 #ifdef PULLDOWN_TEST 1322 /* 1323 * pull single extension header from mbuf chain. returns single mbuf that 1324 * contains the result, or NULL on error. 1325 */ 1326 static struct mbuf * 1327 ip6_pullexthdr(m, off, nxt) 1328 struct mbuf *m; 1329 size_t off; 1330 int nxt; 1331 { 1332 struct ip6_ext ip6e; 1333 size_t elen; 1334 struct mbuf *n; 1335 1336 #ifdef DIAGNOSTIC 1337 switch (nxt) { 1338 case IPPROTO_DSTOPTS: 1339 case IPPROTO_ROUTING: 1340 case IPPROTO_HOPOPTS: 1341 case IPPROTO_AH: /* is it possible? */ 1342 break; 1343 default: 1344 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1345 } 1346 #endif 1347 1348 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1349 if (nxt == IPPROTO_AH) 1350 elen = (ip6e.ip6e_len + 2) << 2; 1351 else 1352 elen = (ip6e.ip6e_len + 1) << 3; 1353 1354 MGET(n, M_DONTWAIT, MT_DATA); 1355 if (n && elen >= MLEN) { 1356 MCLGET(n, M_DONTWAIT); 1357 if ((n->m_flags & M_EXT) == 0) { 1358 m_free(n); 1359 n = NULL; 1360 } 1361 } 1362 if (!n) 1363 return NULL; 1364 1365 n->m_len = 0; 1366 if (elen >= M_TRAILINGSPACE(n)) { 1367 m_free(n); 1368 return NULL; 1369 } 1370 1371 m_copydata(m, off, elen, mtod(n, caddr_t)); 1372 n->m_len = elen; 1373 return n; 1374 } 1375 #endif 1376 1377 /* 1378 * Get pointer to the previous header followed by the header 1379 * currently processed. 1380 * XXX: This function supposes that 1381 * M includes all headers, 1382 * the next header field and the header length field of each header 1383 * are valid, and 1384 * the sum of each header length equals to OFF. 1385 * Because of these assumptions, this function must be called very 1386 * carefully. Moreover, it will not be used in the near future when 1387 * we develop `neater' mechanism to process extension headers. 1388 */ 1389 char * 1390 ip6_get_prevhdr(m, off) 1391 struct mbuf *m; 1392 int off; 1393 { 1394 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1395 1396 if (off == sizeof(struct ip6_hdr)) 1397 return (&ip6->ip6_nxt); 1398 else { 1399 int len, nxt; 1400 struct ip6_ext *ip6e = NULL; 1401 1402 nxt = ip6->ip6_nxt; 1403 len = sizeof(struct ip6_hdr); 1404 while (len < off) { 1405 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1406 1407 switch (nxt) { 1408 case IPPROTO_FRAGMENT: 1409 len += sizeof(struct ip6_frag); 1410 break; 1411 case IPPROTO_AH: 1412 len += (ip6e->ip6e_len + 2) << 2; 1413 break; 1414 default: 1415 len += (ip6e->ip6e_len + 1) << 3; 1416 break; 1417 } 1418 nxt = ip6e->ip6e_nxt; 1419 } 1420 if (ip6e) 1421 return (&ip6e->ip6e_nxt); 1422 else 1423 return NULL; 1424 } 1425 } 1426 1427 /* 1428 * get next header offset. m will be retained. 1429 */ 1430 int 1431 ip6_nexthdr(m, off, proto, nxtp) 1432 struct mbuf *m; 1433 int off; 1434 int proto; 1435 int *nxtp; 1436 { 1437 struct ip6_hdr ip6; 1438 struct ip6_ext ip6e; 1439 struct ip6_frag fh; 1440 1441 /* just in case */ 1442 if (m == NULL) 1443 panic("ip6_nexthdr: m == NULL"); 1444 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1445 return -1; 1446 1447 switch (proto) { 1448 case IPPROTO_IPV6: 1449 if (m->m_pkthdr.len < off + sizeof(ip6)) 1450 return -1; 1451 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1452 if (nxtp) 1453 *nxtp = ip6.ip6_nxt; 1454 off += sizeof(ip6); 1455 return off; 1456 1457 case IPPROTO_FRAGMENT: 1458 /* 1459 * terminate parsing if it is not the first fragment, 1460 * it does not make sense to parse through it. 1461 */ 1462 if (m->m_pkthdr.len < off + sizeof(fh)) 1463 return -1; 1464 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1465 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1466 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1467 return -1; 1468 if (nxtp) 1469 *nxtp = fh.ip6f_nxt; 1470 off += sizeof(struct ip6_frag); 1471 return off; 1472 1473 case IPPROTO_AH: 1474 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1475 return -1; 1476 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1477 if (nxtp) 1478 *nxtp = ip6e.ip6e_nxt; 1479 off += (ip6e.ip6e_len + 2) << 2; 1480 return off; 1481 1482 case IPPROTO_HOPOPTS: 1483 case IPPROTO_ROUTING: 1484 case IPPROTO_DSTOPTS: 1485 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1486 return -1; 1487 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1488 if (nxtp) 1489 *nxtp = ip6e.ip6e_nxt; 1490 off += (ip6e.ip6e_len + 1) << 3; 1491 return off; 1492 1493 case IPPROTO_NONE: 1494 case IPPROTO_ESP: 1495 case IPPROTO_IPCOMP: 1496 /* give up */ 1497 return -1; 1498 1499 default: 1500 return -1; 1501 } 1502 1503 return -1; 1504 } 1505 1506 /* 1507 * get offset for the last header in the chain. m will be kept untainted. 1508 */ 1509 int 1510 ip6_lasthdr(m, off, proto, nxtp) 1511 struct mbuf *m; 1512 int off; 1513 int proto; 1514 int *nxtp; 1515 { 1516 int newoff; 1517 int nxt; 1518 1519 if (!nxtp) { 1520 nxt = -1; 1521 nxtp = &nxt; 1522 } 1523 while (1) { 1524 newoff = ip6_nexthdr(m, off, proto, nxtp); 1525 if (newoff < 0) 1526 return off; 1527 else if (newoff < off) 1528 return -1; /* invalid */ 1529 else if (newoff == off) 1530 return newoff; 1531 1532 off = newoff; 1533 proto = *nxtp; 1534 } 1535 } 1536 1537 struct ip6aux * 1538 ip6_addaux(m) 1539 struct mbuf *m; 1540 { 1541 struct m_tag *mtag; 1542 1543 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1544 if (!mtag) { 1545 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1546 M_NOWAIT); 1547 if (mtag) { 1548 m_tag_prepend(m, mtag); 1549 bzero(mtag + 1, sizeof(struct ip6aux)); 1550 } 1551 } 1552 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1553 } 1554 1555 struct ip6aux * 1556 ip6_findaux(m) 1557 struct mbuf *m; 1558 { 1559 struct m_tag *mtag; 1560 1561 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1562 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1563 } 1564 1565 void 1566 ip6_delaux(m) 1567 struct mbuf *m; 1568 { 1569 struct m_tag *mtag; 1570 1571 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1572 if (mtag) 1573 m_tag_delete(m, mtag); 1574 } 1575 1576 /* 1577 * System control for IP6 1578 */ 1579 1580 u_char inet6ctlerrmap[PRC_NCMDS] = { 1581 0, 0, 0, 0, 1582 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1583 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1584 EMSGSIZE, EHOSTUNREACH, 0, 0, 1585 0, 0, 0, 0, 1586 ENOPROTOOPT 1587 }; 1588