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 <netipsec/ipsec.h> 106 #include <netinet6/ip6_ipsec.h> 107 #include <netipsec/ipsec6.h> 108 #endif /* IPSEC */ 109 110 #include <netinet6/ip6protosw.h> 111 112 extern struct domain inet6domain; 113 114 u_char ip6_protox[IPPROTO_MAX]; 115 static struct ifqueue ip6intrq; 116 static int ip6qmaxlen = IFQ_MAXLEN; 117 struct in6_ifaddr *in6_ifaddr; 118 119 extern struct callout in6_tmpaddrtimer_ch; 120 121 int ip6_forward_srcrt; /* XXX */ 122 int ip6_sourcecheck; /* XXX */ 123 int ip6_sourcecheck_interval; /* XXX */ 124 125 int ip6_ours_check_algorithm; 126 127 struct pfil_head inet6_pfil_hook; 128 129 struct ip6stat ip6stat; 130 131 static void ip6_init2 __P((void *)); 132 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 133 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 134 #ifdef PULLDOWN_TEST 135 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 136 #endif 137 138 /* 139 * IP6 initialization: fill in IP6 protocol switch table. 140 * All protocols not implemented in kernel go to raw IP6 protocol handler. 141 */ 142 void 143 ip6_init(void) 144 { 145 struct ip6protosw *pr; 146 int i; 147 148 #ifdef DIAGNOSTIC 149 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 150 panic("sizeof(protosw) != sizeof(ip6protosw)"); 151 #endif 152 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 153 if (pr == 0) 154 panic("ip6_init"); 155 156 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 157 for (i = 0; i < IPPROTO_MAX; i++) 158 ip6_protox[i] = pr - inet6sw; 159 /* 160 * Cycle through IP protocols and put them into the appropriate place 161 * in ip6_protox[]. 162 */ 163 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 164 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 165 if (pr->pr_domain->dom_family == PF_INET6 && 166 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 167 /* Be careful to only index valid IP protocols. */ 168 if (pr->pr_protocol < IPPROTO_MAX) 169 ip6_protox[pr->pr_protocol] = pr - inet6sw; 170 } 171 172 /* Initialize packet filter hooks. */ 173 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 174 inet6_pfil_hook.ph_af = AF_INET6; 175 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 176 printf("%s: WARNING: unable to register pfil hook, " 177 "error %d\n", __func__, i); 178 179 ip6intrq.ifq_maxlen = ip6qmaxlen; 180 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 181 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 182 scope6_init(); 183 addrsel_policy_init(); 184 nd6_init(); 185 frag6_init(); 186 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 187 } 188 189 static void 190 ip6_init2(void *dummy) 191 { 192 193 /* nd6_timer_init */ 194 callout_init(&nd6_timer_ch, 0); 195 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 196 197 /* timer for regeneranation of temporary addresses randomize ID */ 198 callout_init(&in6_tmpaddrtimer_ch, 0); 199 callout_reset(&in6_tmpaddrtimer_ch, 200 (ip6_temp_preferred_lifetime - ip6_desync_factor - 201 ip6_temp_regen_advance) * hz, 202 in6_tmpaddrtimer, NULL); 203 } 204 205 /* cheat */ 206 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 207 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 208 209 extern struct route_in6 ip6_forward_rt; 210 211 void 212 ip6_input(struct mbuf *m) 213 { 214 struct ip6_hdr *ip6; 215 int off = sizeof(struct ip6_hdr), nest; 216 u_int32_t plen; 217 u_int32_t rtalert = ~0; 218 int nxt, ours = 0; 219 struct ifnet *deliverifp = NULL; 220 struct in6_addr odst; 221 int srcrt = 0; 222 223 GIANT_REQUIRED; /* XXX for now */ 224 225 #ifdef IPSEC 226 /* 227 * should the inner packet be considered authentic? 228 * see comment in ah4_input(). 229 * NB: m cannot be NULL when passed to the input routine 230 */ 231 232 m->m_flags &= ~M_AUTHIPHDR; 233 m->m_flags &= ~M_AUTHIPDGM; 234 235 #endif /* IPSEC */ 236 237 /* 238 * make sure we don't have onion peering information into m_tag. 239 */ 240 ip6_delaux(m); 241 242 /* 243 * mbuf statistics 244 */ 245 if (m->m_flags & M_EXT) { 246 if (m->m_next) 247 ip6stat.ip6s_mext2m++; 248 else 249 ip6stat.ip6s_mext1++; 250 } else { 251 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 252 if (m->m_next) { 253 if (m->m_flags & M_LOOP) { 254 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 255 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 256 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 257 else 258 ip6stat.ip6s_m2m[0]++; 259 } else 260 ip6stat.ip6s_m1++; 261 #undef M2MMAX 262 } 263 264 /* drop the packet if IPv6 operation is disabled on the IF */ 265 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 266 m_freem(m); 267 return; 268 } 269 270 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 271 ip6stat.ip6s_total++; 272 273 #ifndef PULLDOWN_TEST 274 /* 275 * L2 bridge code and some other code can return mbuf chain 276 * that does not conform to KAME requirement. too bad. 277 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 278 */ 279 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 280 struct mbuf *n; 281 282 MGETHDR(n, M_DONTWAIT, MT_HEADER); 283 if (n) 284 M_MOVE_PKTHDR(n, m); 285 if (n && n->m_pkthdr.len > MHLEN) { 286 MCLGET(n, M_DONTWAIT); 287 if ((n->m_flags & M_EXT) == 0) { 288 m_freem(n); 289 n = NULL; 290 } 291 } 292 if (n == NULL) { 293 m_freem(m); 294 return; /* ENOBUFS */ 295 } 296 297 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 298 n->m_len = n->m_pkthdr.len; 299 m_freem(m); 300 m = n; 301 } 302 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 303 #endif 304 305 if (m->m_len < sizeof(struct ip6_hdr)) { 306 struct ifnet *inifp; 307 inifp = m->m_pkthdr.rcvif; 308 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 309 ip6stat.ip6s_toosmall++; 310 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 311 return; 312 } 313 } 314 315 ip6 = mtod(m, struct ip6_hdr *); 316 317 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 318 ip6stat.ip6s_badvers++; 319 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 320 goto bad; 321 } 322 323 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 324 325 /* 326 * Check against address spoofing/corruption. 327 */ 328 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 329 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 330 /* 331 * XXX: "badscope" is not very suitable for a multicast source. 332 */ 333 ip6stat.ip6s_badscope++; 334 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 335 goto bad; 336 } 337 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 338 !(m->m_flags & M_LOOP)) { 339 /* 340 * In this case, the packet should come from the loopback 341 * interface. However, we cannot just check the if_flags, 342 * because ip6_mloopback() passes the "actual" interface 343 * as the outgoing/incoming interface. 344 */ 345 ip6stat.ip6s_badscope++; 346 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 347 goto bad; 348 } 349 350 #ifdef ALTQ 351 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 352 /* packet is dropped by traffic conditioner */ 353 return; 354 } 355 #endif 356 /* 357 * The following check is not documented in specs. A malicious 358 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 359 * and bypass security checks (act as if it was from 127.0.0.1 by using 360 * IPv6 src ::ffff:127.0.0.1). Be cautious. 361 * 362 * This check chokes if we are in an SIIT cloud. As none of BSDs 363 * support IPv4-less kernel compilation, we cannot support SIIT 364 * environment at all. So, it makes more sense for us to reject any 365 * malicious packets for non-SIIT environment, than try to do a 366 * partial support for SIIT environment. 367 */ 368 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 369 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 370 ip6stat.ip6s_badscope++; 371 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 372 goto bad; 373 } 374 #if 0 375 /* 376 * Reject packets with IPv4 compatible addresses (auto tunnel). 377 * 378 * The code forbids auto tunnel relay case in RFC1933 (the check is 379 * stronger than RFC1933). We may want to re-enable it if mech-xx 380 * is revised to forbid relaying case. 381 */ 382 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 383 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 384 ip6stat.ip6s_badscope++; 385 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 386 goto bad; 387 } 388 #endif 389 390 /* 391 * Run through list of hooks for input packets. 392 * 393 * NB: Beware of the destination address changing 394 * (e.g. by NAT rewriting). When this happens, 395 * tell ip6_forward to do the right thing. 396 */ 397 odst = ip6->ip6_dst; 398 399 /* Jump over all PFIL processing if hooks are not active. */ 400 if (!PFIL_HOOKED(&inet6_pfil_hook)) 401 goto passin; 402 403 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 404 return; 405 if (m == NULL) /* consumed by filter */ 406 return; 407 ip6 = mtod(m, struct ip6_hdr *); 408 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 409 410 passin: 411 /* 412 * Disambiguate address scope zones (if there is ambiguity). 413 * We first make sure that the original source or destination address 414 * is not in our internal form for scoped addresses. Such addresses 415 * are not necessarily invalid spec-wise, but we cannot accept them due 416 * to the usage conflict. 417 * in6_setscope() then also checks and rejects the cases where src or 418 * dst are the loopback address and the receiving interface 419 * is not loopback. 420 */ 421 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 422 ip6stat.ip6s_badscope++; /* XXX */ 423 goto bad; 424 } 425 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 426 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 427 ip6stat.ip6s_badscope++; 428 goto bad; 429 } 430 431 /* 432 * Multicast check 433 */ 434 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 435 struct in6_multi *in6m = 0; 436 437 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 438 /* 439 * See if we belong to the destination multicast group on the 440 * arrival interface. 441 */ 442 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 443 if (in6m) 444 ours = 1; 445 else if (!ip6_mrouter) { 446 ip6stat.ip6s_notmember++; 447 ip6stat.ip6s_cantforward++; 448 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 449 goto bad; 450 } 451 deliverifp = m->m_pkthdr.rcvif; 452 goto hbhcheck; 453 } 454 455 /* 456 * Unicast check 457 */ 458 if (ip6_forward_rt.ro_rt != NULL && 459 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 460 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 461 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 462 ip6stat.ip6s_forward_cachehit++; 463 else { 464 struct sockaddr_in6 *dst6; 465 466 if (ip6_forward_rt.ro_rt) { 467 /* route is down or destination is different */ 468 ip6stat.ip6s_forward_cachemiss++; 469 RTFREE(ip6_forward_rt.ro_rt); 470 ip6_forward_rt.ro_rt = 0; 471 } 472 473 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 474 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 475 dst6->sin6_len = sizeof(struct sockaddr_in6); 476 dst6->sin6_family = AF_INET6; 477 dst6->sin6_addr = ip6->ip6_dst; 478 479 rtalloc((struct route *)&ip6_forward_rt); 480 } 481 482 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 483 484 /* 485 * Accept the packet if the forwarding interface to the destination 486 * according to the routing table is the loopback interface, 487 * unless the associated route has a gateway. 488 * Note that this approach causes to accept a packet if there is a 489 * route to the loopback interface for the destination of the packet. 490 * But we think it's even useful in some situations, e.g. when using 491 * a special daemon which wants to intercept the packet. 492 * 493 * XXX: some OSes automatically make a cloned route for the destination 494 * of an outgoing packet. If the outgoing interface of the packet 495 * is a loopback one, the kernel would consider the packet to be 496 * accepted, even if we have no such address assinged on the interface. 497 * We check the cloned flag of the route entry to reject such cases, 498 * assuming that route entries for our own addresses are not made by 499 * cloning (it should be true because in6_addloop explicitly installs 500 * the host route). However, we might have to do an explicit check 501 * while it would be less efficient. Or, should we rather install a 502 * reject route for such a case? 503 */ 504 if (ip6_forward_rt.ro_rt && 505 (ip6_forward_rt.ro_rt->rt_flags & 506 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 507 #ifdef RTF_WASCLONED 508 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 509 #endif 510 #ifdef RTF_CLONED 511 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 512 #endif 513 #if 0 514 /* 515 * The check below is redundant since the comparison of 516 * the destination and the key of the rtentry has 517 * already done through looking up the routing table. 518 */ 519 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 520 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 521 #endif 522 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 523 struct in6_ifaddr *ia6 = 524 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 525 526 /* 527 * record address information into m_tag. 528 */ 529 (void)ip6_setdstifaddr(m, ia6); 530 531 /* 532 * packets to a tentative, duplicated, or somehow invalid 533 * address must not be accepted. 534 */ 535 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 536 /* this address is ready */ 537 ours = 1; 538 deliverifp = ia6->ia_ifp; /* correct? */ 539 /* Count the packet in the ip address stats */ 540 ia6->ia_ifa.if_ipackets++; 541 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 542 goto hbhcheck; 543 } else { 544 char ip6bufs[INET6_ADDRSTRLEN]; 545 char ip6bufd[INET6_ADDRSTRLEN]; 546 /* address is not ready, so discard the packet. */ 547 nd6log((LOG_INFO, 548 "ip6_input: packet to an unready address %s->%s\n", 549 ip6_sprintf(ip6bufs, &ip6->ip6_src), 550 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 551 552 goto bad; 553 } 554 } 555 556 /* 557 * FAITH (Firewall Aided Internet Translator) 558 */ 559 if (ip6_keepfaith) { 560 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 561 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 562 /* XXX do we need more sanity checks? */ 563 ours = 1; 564 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 565 goto hbhcheck; 566 } 567 } 568 569 /* 570 * Now there is no reason to process the packet if it's not our own 571 * and we're not a router. 572 */ 573 if (!ip6_forwarding) { 574 ip6stat.ip6s_cantforward++; 575 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 576 goto bad; 577 } 578 579 hbhcheck: 580 /* 581 * record address information into m_tag, if we don't have one yet. 582 * note that we are unable to record it, if the address is not listed 583 * as our interface address (e.g. multicast addresses, addresses 584 * within FAITH prefixes and such). 585 */ 586 if (deliverifp && !ip6_getdstifaddr(m)) { 587 struct in6_ifaddr *ia6; 588 589 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 590 if (ia6) { 591 if (!ip6_setdstifaddr(m, ia6)) { 592 /* 593 * XXX maybe we should drop the packet here, 594 * as we could not provide enough information 595 * to the upper layers. 596 */ 597 } 598 } 599 } 600 601 /* 602 * Process Hop-by-Hop options header if it's contained. 603 * m may be modified in ip6_hopopts_input(). 604 * If a JumboPayload option is included, plen will also be modified. 605 */ 606 plen = (u_int32_t)ntohs(ip6->ip6_plen); 607 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 608 struct ip6_hbh *hbh; 609 610 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 611 #if 0 /*touches NULL pointer*/ 612 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 613 #endif 614 return; /* m have already been freed */ 615 } 616 617 /* adjust pointer */ 618 ip6 = mtod(m, struct ip6_hdr *); 619 620 /* 621 * if the payload length field is 0 and the next header field 622 * indicates Hop-by-Hop Options header, then a Jumbo Payload 623 * option MUST be included. 624 */ 625 if (ip6->ip6_plen == 0 && plen == 0) { 626 /* 627 * Note that if a valid jumbo payload option is 628 * contained, ip6_hopopts_input() must set a valid 629 * (non-zero) payload length to the variable plen. 630 */ 631 ip6stat.ip6s_badoptions++; 632 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 633 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 634 icmp6_error(m, ICMP6_PARAM_PROB, 635 ICMP6_PARAMPROB_HEADER, 636 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 637 return; 638 } 639 #ifndef PULLDOWN_TEST 640 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 641 hbh = (struct ip6_hbh *)(ip6 + 1); 642 #else 643 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 644 sizeof(struct ip6_hbh)); 645 if (hbh == NULL) { 646 ip6stat.ip6s_tooshort++; 647 return; 648 } 649 #endif 650 nxt = hbh->ip6h_nxt; 651 652 /* 653 * If we are acting as a router and the packet contains a 654 * router alert option, see if we know the option value. 655 * Currently, we only support the option value for MLD, in which 656 * case we should pass the packet to the multicast routing 657 * daemon. 658 */ 659 if (rtalert != ~0 && ip6_forwarding) { 660 switch (rtalert) { 661 case IP6OPT_RTALERT_MLD: 662 ours = 1; 663 break; 664 default: 665 /* 666 * RFC2711 requires unrecognized values must be 667 * silently ignored. 668 */ 669 break; 670 } 671 } 672 } else 673 nxt = ip6->ip6_nxt; 674 675 /* 676 * Check that the amount of data in the buffers 677 * is as at least much as the IPv6 header would have us expect. 678 * Trim mbufs if longer than we expect. 679 * Drop packet if shorter than we expect. 680 */ 681 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 682 ip6stat.ip6s_tooshort++; 683 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 684 goto bad; 685 } 686 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 687 if (m->m_len == m->m_pkthdr.len) { 688 m->m_len = sizeof(struct ip6_hdr) + plen; 689 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 690 } else 691 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 692 } 693 694 /* 695 * Forward if desirable. 696 */ 697 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 698 /* 699 * If we are acting as a multicast router, all 700 * incoming multicast packets are passed to the 701 * kernel-level multicast forwarding function. 702 * The packet is returned (relatively) intact; if 703 * ip6_mforward() returns a non-zero value, the packet 704 * must be discarded, else it may be accepted below. 705 */ 706 if (ip6_mrouter && ip6_mforward && 707 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 708 ip6stat.ip6s_cantforward++; 709 m_freem(m); 710 return; 711 } 712 if (!ours) { 713 m_freem(m); 714 return; 715 } 716 } else if (!ours) { 717 ip6_forward(m, srcrt); 718 return; 719 } 720 721 ip6 = mtod(m, struct ip6_hdr *); 722 723 /* 724 * Malicious party may be able to use IPv4 mapped addr to confuse 725 * tcp/udp stack and bypass security checks (act as if it was from 726 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 727 * 728 * For SIIT end node behavior, you may want to disable the check. 729 * However, you will become vulnerable to attacks using IPv4 mapped 730 * source. 731 */ 732 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 733 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 734 ip6stat.ip6s_badscope++; 735 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 736 goto bad; 737 } 738 739 /* 740 * Tell launch routine the next header 741 */ 742 ip6stat.ip6s_delivered++; 743 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 744 nest = 0; 745 746 while (nxt != IPPROTO_DONE) { 747 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 748 ip6stat.ip6s_toomanyhdr++; 749 goto bad; 750 } 751 752 /* 753 * protection against faulty packet - there should be 754 * more sanity checks in header chain processing. 755 */ 756 if (m->m_pkthdr.len < off) { 757 ip6stat.ip6s_tooshort++; 758 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 759 goto bad; 760 } 761 762 #ifdef IPSEC 763 /* 764 * enforce IPsec policy checking if we are seeing last header. 765 * note that we do not visit this with protocols with pcb layer 766 * code - like udp/tcp/raw ip. 767 */ 768 if (ip6_ipsec_input(m, nxt)) 769 goto bad; 770 #endif /* IPSEC */ 771 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 772 } 773 return; 774 bad: 775 m_freem(m); 776 } 777 778 /* 779 * set/grab in6_ifaddr correspond to IPv6 destination address. 780 * XXX backward compatibility wrapper 781 */ 782 static struct ip6aux * 783 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 784 { 785 struct ip6aux *ip6a; 786 787 ip6a = ip6_addaux(m); 788 if (ip6a) 789 ip6a->ip6a_dstia6 = ia6; 790 return ip6a; /* NULL if failed to set */ 791 } 792 793 struct in6_ifaddr * 794 ip6_getdstifaddr(struct mbuf *m) 795 { 796 struct ip6aux *ip6a; 797 798 ip6a = ip6_findaux(m); 799 if (ip6a) 800 return ip6a->ip6a_dstia6; 801 else 802 return NULL; 803 } 804 805 /* 806 * Hop-by-Hop options header processing. If a valid jumbo payload option is 807 * included, the real payload length will be stored in plenp. 808 * 809 * rtalertp - XXX: should be stored more smart way 810 */ 811 static int 812 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 813 struct mbuf **mp, int *offp) 814 { 815 struct mbuf *m = *mp; 816 int off = *offp, hbhlen; 817 struct ip6_hbh *hbh; 818 u_int8_t *opt; 819 820 /* validation of the length of the header */ 821 #ifndef PULLDOWN_TEST 822 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 823 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 824 hbhlen = (hbh->ip6h_len + 1) << 3; 825 826 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 827 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 828 #else 829 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 830 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 831 if (hbh == NULL) { 832 ip6stat.ip6s_tooshort++; 833 return -1; 834 } 835 hbhlen = (hbh->ip6h_len + 1) << 3; 836 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 837 hbhlen); 838 if (hbh == NULL) { 839 ip6stat.ip6s_tooshort++; 840 return -1; 841 } 842 #endif 843 off += hbhlen; 844 hbhlen -= sizeof(struct ip6_hbh); 845 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 846 847 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 848 hbhlen, rtalertp, plenp) < 0) 849 return (-1); 850 851 *offp = off; 852 *mp = m; 853 return (0); 854 } 855 856 /* 857 * Search header for all Hop-by-hop options and process each option. 858 * This function is separate from ip6_hopopts_input() in order to 859 * handle a case where the sending node itself process its hop-by-hop 860 * options header. In such a case, the function is called from ip6_output(). 861 * 862 * The function assumes that hbh header is located right after the IPv6 header 863 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 864 * opthead + hbhlen is located in continuous memory region. 865 */ 866 int 867 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 868 u_int32_t *rtalertp, u_int32_t *plenp) 869 { 870 struct ip6_hdr *ip6; 871 int optlen = 0; 872 u_int8_t *opt = opthead; 873 u_int16_t rtalert_val; 874 u_int32_t jumboplen; 875 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 876 877 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 878 switch (*opt) { 879 case IP6OPT_PAD1: 880 optlen = 1; 881 break; 882 case IP6OPT_PADN: 883 if (hbhlen < IP6OPT_MINLEN) { 884 ip6stat.ip6s_toosmall++; 885 goto bad; 886 } 887 optlen = *(opt + 1) + 2; 888 break; 889 case IP6OPT_ROUTER_ALERT: 890 /* XXX may need check for alignment */ 891 if (hbhlen < IP6OPT_RTALERT_LEN) { 892 ip6stat.ip6s_toosmall++; 893 goto bad; 894 } 895 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 896 /* XXX stat */ 897 icmp6_error(m, ICMP6_PARAM_PROB, 898 ICMP6_PARAMPROB_HEADER, 899 erroff + opt + 1 - opthead); 900 return (-1); 901 } 902 optlen = IP6OPT_RTALERT_LEN; 903 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 904 *rtalertp = ntohs(rtalert_val); 905 break; 906 case IP6OPT_JUMBO: 907 /* XXX may need check for alignment */ 908 if (hbhlen < IP6OPT_JUMBO_LEN) { 909 ip6stat.ip6s_toosmall++; 910 goto bad; 911 } 912 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 913 /* XXX stat */ 914 icmp6_error(m, ICMP6_PARAM_PROB, 915 ICMP6_PARAMPROB_HEADER, 916 erroff + opt + 1 - opthead); 917 return (-1); 918 } 919 optlen = IP6OPT_JUMBO_LEN; 920 921 /* 922 * IPv6 packets that have non 0 payload length 923 * must not contain a jumbo payload option. 924 */ 925 ip6 = mtod(m, struct ip6_hdr *); 926 if (ip6->ip6_plen) { 927 ip6stat.ip6s_badoptions++; 928 icmp6_error(m, ICMP6_PARAM_PROB, 929 ICMP6_PARAMPROB_HEADER, 930 erroff + opt - opthead); 931 return (-1); 932 } 933 934 /* 935 * We may see jumbolen in unaligned location, so 936 * we'd need to perform bcopy(). 937 */ 938 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 939 jumboplen = (u_int32_t)htonl(jumboplen); 940 941 #if 1 942 /* 943 * if there are multiple jumbo payload options, 944 * *plenp will be non-zero and the packet will be 945 * rejected. 946 * the behavior may need some debate in ipngwg - 947 * multiple options does not make sense, however, 948 * there's no explicit mention in specification. 949 */ 950 if (*plenp != 0) { 951 ip6stat.ip6s_badoptions++; 952 icmp6_error(m, ICMP6_PARAM_PROB, 953 ICMP6_PARAMPROB_HEADER, 954 erroff + opt + 2 - opthead); 955 return (-1); 956 } 957 #endif 958 959 /* 960 * jumbo payload length must be larger than 65535. 961 */ 962 if (jumboplen <= IPV6_MAXPACKET) { 963 ip6stat.ip6s_badoptions++; 964 icmp6_error(m, ICMP6_PARAM_PROB, 965 ICMP6_PARAMPROB_HEADER, 966 erroff + opt + 2 - opthead); 967 return (-1); 968 } 969 *plenp = jumboplen; 970 971 break; 972 default: /* unknown option */ 973 if (hbhlen < IP6OPT_MINLEN) { 974 ip6stat.ip6s_toosmall++; 975 goto bad; 976 } 977 optlen = ip6_unknown_opt(opt, m, 978 erroff + opt - opthead); 979 if (optlen == -1) 980 return (-1); 981 optlen += 2; 982 break; 983 } 984 } 985 986 return (0); 987 988 bad: 989 m_freem(m); 990 return (-1); 991 } 992 993 /* 994 * Unknown option processing. 995 * The third argument `off' is the offset from the IPv6 header to the option, 996 * which is necessary if the IPv6 header the and option header and IPv6 header 997 * is not continuous in order to return an ICMPv6 error. 998 */ 999 int 1000 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1001 { 1002 struct ip6_hdr *ip6; 1003 1004 switch (IP6OPT_TYPE(*optp)) { 1005 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1006 return ((int)*(optp + 1)); 1007 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1008 m_freem(m); 1009 return (-1); 1010 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1011 ip6stat.ip6s_badoptions++; 1012 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1013 return (-1); 1014 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1015 ip6stat.ip6s_badoptions++; 1016 ip6 = mtod(m, struct ip6_hdr *); 1017 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1018 (m->m_flags & (M_BCAST|M_MCAST))) 1019 m_freem(m); 1020 else 1021 icmp6_error(m, ICMP6_PARAM_PROB, 1022 ICMP6_PARAMPROB_OPTION, off); 1023 return (-1); 1024 } 1025 1026 m_freem(m); /* XXX: NOTREACHED */ 1027 return (-1); 1028 } 1029 1030 /* 1031 * Create the "control" list for this pcb. 1032 * The function will not modify mbuf chain at all. 1033 * 1034 * with KAME mbuf chain restriction: 1035 * The routine will be called from upper layer handlers like tcp6_input(). 1036 * Thus the routine assumes that the caller (tcp6_input) have already 1037 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1038 * very first mbuf on the mbuf chain. 1039 */ 1040 void 1041 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1042 { 1043 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1044 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1045 1046 #ifdef SO_TIMESTAMP 1047 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1048 struct timeval tv; 1049 1050 microtime(&tv); 1051 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1052 SCM_TIMESTAMP, SOL_SOCKET); 1053 if (*mp) 1054 mp = &(*mp)->m_next; 1055 } 1056 #endif 1057 1058 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1059 return; 1060 1061 /* RFC 2292 sec. 5 */ 1062 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1063 struct in6_pktinfo pi6; 1064 1065 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1066 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1067 pi6.ipi6_ifindex = 1068 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1069 1070 *mp = sbcreatecontrol((caddr_t) &pi6, 1071 sizeof(struct in6_pktinfo), 1072 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1073 if (*mp) 1074 mp = &(*mp)->m_next; 1075 } 1076 1077 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1078 int hlim = ip6->ip6_hlim & 0xff; 1079 1080 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1081 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1082 if (*mp) 1083 mp = &(*mp)->m_next; 1084 } 1085 1086 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1087 u_int32_t flowinfo; 1088 int tclass; 1089 1090 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1091 flowinfo >>= 20; 1092 1093 tclass = flowinfo & 0xff; 1094 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1095 IPV6_TCLASS, IPPROTO_IPV6); 1096 if (*mp) 1097 mp = &(*mp)->m_next; 1098 } 1099 1100 /* 1101 * IPV6_HOPOPTS socket option. Recall that we required super-user 1102 * privilege for the option (see ip6_ctloutput), but it might be too 1103 * strict, since there might be some hop-by-hop options which can be 1104 * returned to normal user. 1105 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1106 */ 1107 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1108 /* 1109 * Check if a hop-by-hop options header is contatined in the 1110 * received packet, and if so, store the options as ancillary 1111 * data. Note that a hop-by-hop options header must be 1112 * just after the IPv6 header, which is assured through the 1113 * IPv6 input processing. 1114 */ 1115 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1116 struct ip6_hbh *hbh; 1117 int hbhlen = 0; 1118 #ifdef PULLDOWN_TEST 1119 struct mbuf *ext; 1120 #endif 1121 1122 #ifndef PULLDOWN_TEST 1123 hbh = (struct ip6_hbh *)(ip6 + 1); 1124 hbhlen = (hbh->ip6h_len + 1) << 3; 1125 #else 1126 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1127 ip6->ip6_nxt); 1128 if (ext == NULL) { 1129 ip6stat.ip6s_tooshort++; 1130 return; 1131 } 1132 hbh = mtod(ext, struct ip6_hbh *); 1133 hbhlen = (hbh->ip6h_len + 1) << 3; 1134 if (hbhlen != ext->m_len) { 1135 m_freem(ext); 1136 ip6stat.ip6s_tooshort++; 1137 return; 1138 } 1139 #endif 1140 1141 /* 1142 * XXX: We copy the whole header even if a 1143 * jumbo payload option is included, the option which 1144 * is to be removed before returning according to 1145 * RFC2292. 1146 * Note: this constraint is removed in RFC3542 1147 */ 1148 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1149 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1150 IPPROTO_IPV6); 1151 if (*mp) 1152 mp = &(*mp)->m_next; 1153 #ifdef PULLDOWN_TEST 1154 m_freem(ext); 1155 #endif 1156 } 1157 } 1158 1159 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1160 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1161 1162 /* 1163 * Search for destination options headers or routing 1164 * header(s) through the header chain, and stores each 1165 * header as ancillary data. 1166 * Note that the order of the headers remains in 1167 * the chain of ancillary data. 1168 */ 1169 while (1) { /* is explicit loop prevention necessary? */ 1170 struct ip6_ext *ip6e = NULL; 1171 int elen; 1172 #ifdef PULLDOWN_TEST 1173 struct mbuf *ext = NULL; 1174 #endif 1175 1176 /* 1177 * if it is not an extension header, don't try to 1178 * pull it from the chain. 1179 */ 1180 switch (nxt) { 1181 case IPPROTO_DSTOPTS: 1182 case IPPROTO_ROUTING: 1183 case IPPROTO_HOPOPTS: 1184 case IPPROTO_AH: /* is it possible? */ 1185 break; 1186 default: 1187 goto loopend; 1188 } 1189 1190 #ifndef PULLDOWN_TEST 1191 if (off + sizeof(*ip6e) > m->m_len) 1192 goto loopend; 1193 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1194 if (nxt == IPPROTO_AH) 1195 elen = (ip6e->ip6e_len + 2) << 2; 1196 else 1197 elen = (ip6e->ip6e_len + 1) << 3; 1198 if (off + elen > m->m_len) 1199 goto loopend; 1200 #else 1201 ext = ip6_pullexthdr(m, off, nxt); 1202 if (ext == NULL) { 1203 ip6stat.ip6s_tooshort++; 1204 return; 1205 } 1206 ip6e = mtod(ext, struct ip6_ext *); 1207 if (nxt == IPPROTO_AH) 1208 elen = (ip6e->ip6e_len + 2) << 2; 1209 else 1210 elen = (ip6e->ip6e_len + 1) << 3; 1211 if (elen != ext->m_len) { 1212 m_freem(ext); 1213 ip6stat.ip6s_tooshort++; 1214 return; 1215 } 1216 #endif 1217 1218 switch (nxt) { 1219 case IPPROTO_DSTOPTS: 1220 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1221 break; 1222 1223 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1224 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1225 IPPROTO_IPV6); 1226 if (*mp) 1227 mp = &(*mp)->m_next; 1228 break; 1229 case IPPROTO_ROUTING: 1230 if (!in6p->in6p_flags & IN6P_RTHDR) 1231 break; 1232 1233 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1234 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1235 IPPROTO_IPV6); 1236 if (*mp) 1237 mp = &(*mp)->m_next; 1238 break; 1239 case IPPROTO_HOPOPTS: 1240 case IPPROTO_AH: /* is it possible? */ 1241 break; 1242 1243 default: 1244 /* 1245 * other cases have been filtered in the above. 1246 * none will visit this case. here we supply 1247 * the code just in case (nxt overwritten or 1248 * other cases). 1249 */ 1250 #ifdef PULLDOWN_TEST 1251 m_freem(ext); 1252 #endif 1253 goto loopend; 1254 1255 } 1256 1257 /* proceed with the next header. */ 1258 off += elen; 1259 nxt = ip6e->ip6e_nxt; 1260 ip6e = NULL; 1261 #ifdef PULLDOWN_TEST 1262 m_freem(ext); 1263 ext = NULL; 1264 #endif 1265 } 1266 loopend: 1267 ; 1268 } 1269 1270 #undef IS2292 1271 } 1272 1273 void 1274 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1275 { 1276 struct socket *so; 1277 struct mbuf *m_mtu; 1278 struct ip6_mtuinfo mtuctl; 1279 1280 so = in6p->inp_socket; 1281 1282 if (mtu == NULL) 1283 return; 1284 1285 #ifdef DIAGNOSTIC 1286 if (so == NULL) /* I believe this is impossible */ 1287 panic("ip6_notify_pmtu: socket is NULL"); 1288 #endif 1289 1290 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1291 mtuctl.ip6m_mtu = *mtu; 1292 mtuctl.ip6m_addr = *dst; 1293 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1294 return; 1295 1296 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1297 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1298 return; 1299 1300 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1301 == 0) { 1302 m_freem(m_mtu); 1303 /* XXX: should count statistics */ 1304 } else 1305 sorwakeup(so); 1306 1307 return; 1308 } 1309 1310 #ifdef PULLDOWN_TEST 1311 /* 1312 * pull single extension header from mbuf chain. returns single mbuf that 1313 * contains the result, or NULL on error. 1314 */ 1315 static struct mbuf * 1316 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1317 { 1318 struct ip6_ext ip6e; 1319 size_t elen; 1320 struct mbuf *n; 1321 1322 #ifdef DIAGNOSTIC 1323 switch (nxt) { 1324 case IPPROTO_DSTOPTS: 1325 case IPPROTO_ROUTING: 1326 case IPPROTO_HOPOPTS: 1327 case IPPROTO_AH: /* is it possible? */ 1328 break; 1329 default: 1330 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1331 } 1332 #endif 1333 1334 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1335 if (nxt == IPPROTO_AH) 1336 elen = (ip6e.ip6e_len + 2) << 2; 1337 else 1338 elen = (ip6e.ip6e_len + 1) << 3; 1339 1340 MGET(n, M_DONTWAIT, MT_DATA); 1341 if (n && elen >= MLEN) { 1342 MCLGET(n, M_DONTWAIT); 1343 if ((n->m_flags & M_EXT) == 0) { 1344 m_free(n); 1345 n = NULL; 1346 } 1347 } 1348 if (!n) 1349 return NULL; 1350 1351 n->m_len = 0; 1352 if (elen >= M_TRAILINGSPACE(n)) { 1353 m_free(n); 1354 return NULL; 1355 } 1356 1357 m_copydata(m, off, elen, mtod(n, caddr_t)); 1358 n->m_len = elen; 1359 return n; 1360 } 1361 #endif 1362 1363 /* 1364 * Get pointer to the previous header followed by the header 1365 * currently processed. 1366 * XXX: This function supposes that 1367 * M includes all headers, 1368 * the next header field and the header length field of each header 1369 * are valid, and 1370 * the sum of each header length equals to OFF. 1371 * Because of these assumptions, this function must be called very 1372 * carefully. Moreover, it will not be used in the near future when 1373 * we develop `neater' mechanism to process extension headers. 1374 */ 1375 char * 1376 ip6_get_prevhdr(struct mbuf *m, int off) 1377 { 1378 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1379 1380 if (off == sizeof(struct ip6_hdr)) 1381 return (&ip6->ip6_nxt); 1382 else { 1383 int len, nxt; 1384 struct ip6_ext *ip6e = NULL; 1385 1386 nxt = ip6->ip6_nxt; 1387 len = sizeof(struct ip6_hdr); 1388 while (len < off) { 1389 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1390 1391 switch (nxt) { 1392 case IPPROTO_FRAGMENT: 1393 len += sizeof(struct ip6_frag); 1394 break; 1395 case IPPROTO_AH: 1396 len += (ip6e->ip6e_len + 2) << 2; 1397 break; 1398 default: 1399 len += (ip6e->ip6e_len + 1) << 3; 1400 break; 1401 } 1402 nxt = ip6e->ip6e_nxt; 1403 } 1404 if (ip6e) 1405 return (&ip6e->ip6e_nxt); 1406 else 1407 return NULL; 1408 } 1409 } 1410 1411 /* 1412 * get next header offset. m will be retained. 1413 */ 1414 int 1415 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1416 { 1417 struct ip6_hdr ip6; 1418 struct ip6_ext ip6e; 1419 struct ip6_frag fh; 1420 1421 /* just in case */ 1422 if (m == NULL) 1423 panic("ip6_nexthdr: m == NULL"); 1424 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1425 return -1; 1426 1427 switch (proto) { 1428 case IPPROTO_IPV6: 1429 if (m->m_pkthdr.len < off + sizeof(ip6)) 1430 return -1; 1431 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1432 if (nxtp) 1433 *nxtp = ip6.ip6_nxt; 1434 off += sizeof(ip6); 1435 return off; 1436 1437 case IPPROTO_FRAGMENT: 1438 /* 1439 * terminate parsing if it is not the first fragment, 1440 * it does not make sense to parse through it. 1441 */ 1442 if (m->m_pkthdr.len < off + sizeof(fh)) 1443 return -1; 1444 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1445 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1446 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1447 return -1; 1448 if (nxtp) 1449 *nxtp = fh.ip6f_nxt; 1450 off += sizeof(struct ip6_frag); 1451 return off; 1452 1453 case IPPROTO_AH: 1454 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1455 return -1; 1456 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1457 if (nxtp) 1458 *nxtp = ip6e.ip6e_nxt; 1459 off += (ip6e.ip6e_len + 2) << 2; 1460 return off; 1461 1462 case IPPROTO_HOPOPTS: 1463 case IPPROTO_ROUTING: 1464 case IPPROTO_DSTOPTS: 1465 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1466 return -1; 1467 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1468 if (nxtp) 1469 *nxtp = ip6e.ip6e_nxt; 1470 off += (ip6e.ip6e_len + 1) << 3; 1471 return off; 1472 1473 case IPPROTO_NONE: 1474 case IPPROTO_ESP: 1475 case IPPROTO_IPCOMP: 1476 /* give up */ 1477 return -1; 1478 1479 default: 1480 return -1; 1481 } 1482 1483 return -1; 1484 } 1485 1486 /* 1487 * get offset for the last header in the chain. m will be kept untainted. 1488 */ 1489 int 1490 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1491 { 1492 int newoff; 1493 int nxt; 1494 1495 if (!nxtp) { 1496 nxt = -1; 1497 nxtp = &nxt; 1498 } 1499 while (1) { 1500 newoff = ip6_nexthdr(m, off, proto, nxtp); 1501 if (newoff < 0) 1502 return off; 1503 else if (newoff < off) 1504 return -1; /* invalid */ 1505 else if (newoff == off) 1506 return newoff; 1507 1508 off = newoff; 1509 proto = *nxtp; 1510 } 1511 } 1512 1513 struct ip6aux * 1514 ip6_addaux(struct mbuf *m) 1515 { 1516 struct m_tag *mtag; 1517 1518 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1519 if (!mtag) { 1520 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1521 M_NOWAIT); 1522 if (mtag) { 1523 m_tag_prepend(m, mtag); 1524 bzero(mtag + 1, sizeof(struct ip6aux)); 1525 } 1526 } 1527 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1528 } 1529 1530 struct ip6aux * 1531 ip6_findaux(struct mbuf *m) 1532 { 1533 struct m_tag *mtag; 1534 1535 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1536 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1537 } 1538 1539 void 1540 ip6_delaux(struct mbuf *m) 1541 { 1542 struct m_tag *mtag; 1543 1544 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1545 if (mtag) 1546 m_tag_delete(m, mtag); 1547 } 1548 1549 /* 1550 * System control for IP6 1551 */ 1552 1553 u_char inet6ctlerrmap[PRC_NCMDS] = { 1554 0, 0, 0, 0, 1555 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1556 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1557 EMSGSIZE, EHOSTUNREACH, 0, 0, 1558 0, 0, 0, 0, 1559 ENOPROTOOPT 1560 }; 1561