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 /* address is not ready, so discard the packet. */ 552 nd6log((LOG_INFO, 553 "ip6_input: packet to an unready address %s->%s\n", 554 ip6_sprintf(&ip6->ip6_src), 555 ip6_sprintf(&ip6->ip6_dst))); 556 557 goto bad; 558 } 559 } 560 561 /* 562 * FAITH (Firewall Aided Internet Translator) 563 */ 564 if (ip6_keepfaith) { 565 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 566 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 567 /* XXX do we need more sanity checks? */ 568 ours = 1; 569 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 570 goto hbhcheck; 571 } 572 } 573 574 /* 575 * Now there is no reason to process the packet if it's not our own 576 * and we're not a router. 577 */ 578 if (!ip6_forwarding) { 579 ip6stat.ip6s_cantforward++; 580 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 581 goto bad; 582 } 583 584 hbhcheck: 585 /* 586 * record address information into m_tag, if we don't have one yet. 587 * note that we are unable to record it, if the address is not listed 588 * as our interface address (e.g. multicast addresses, addresses 589 * within FAITH prefixes and such). 590 */ 591 if (deliverifp && !ip6_getdstifaddr(m)) { 592 struct in6_ifaddr *ia6; 593 594 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 595 if (ia6) { 596 if (!ip6_setdstifaddr(m, ia6)) { 597 /* 598 * XXX maybe we should drop the packet here, 599 * as we could not provide enough information 600 * to the upper layers. 601 */ 602 } 603 } 604 } 605 606 /* 607 * Process Hop-by-Hop options header if it's contained. 608 * m may be modified in ip6_hopopts_input(). 609 * If a JumboPayload option is included, plen will also be modified. 610 */ 611 plen = (u_int32_t)ntohs(ip6->ip6_plen); 612 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 613 struct ip6_hbh *hbh; 614 615 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 616 #if 0 /*touches NULL pointer*/ 617 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 618 #endif 619 return; /* m have already been freed */ 620 } 621 622 /* adjust pointer */ 623 ip6 = mtod(m, struct ip6_hdr *); 624 625 /* 626 * if the payload length field is 0 and the next header field 627 * indicates Hop-by-Hop Options header, then a Jumbo Payload 628 * option MUST be included. 629 */ 630 if (ip6->ip6_plen == 0 && plen == 0) { 631 /* 632 * Note that if a valid jumbo payload option is 633 * contained, ip6_hopopts_input() must set a valid 634 * (non-zero) payload length to the variable plen. 635 */ 636 ip6stat.ip6s_badoptions++; 637 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 638 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 639 icmp6_error(m, ICMP6_PARAM_PROB, 640 ICMP6_PARAMPROB_HEADER, 641 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 642 return; 643 } 644 #ifndef PULLDOWN_TEST 645 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 646 hbh = (struct ip6_hbh *)(ip6 + 1); 647 #else 648 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 649 sizeof(struct ip6_hbh)); 650 if (hbh == NULL) { 651 ip6stat.ip6s_tooshort++; 652 return; 653 } 654 #endif 655 nxt = hbh->ip6h_nxt; 656 657 /* 658 * accept the packet if a router alert option is included 659 * and we act as an IPv6 router. 660 */ 661 if (rtalert != ~0 && ip6_forwarding) 662 ours = 1; 663 } else 664 nxt = ip6->ip6_nxt; 665 666 /* 667 * Check that the amount of data in the buffers 668 * is as at least much as the IPv6 header would have us expect. 669 * Trim mbufs if longer than we expect. 670 * Drop packet if shorter than we expect. 671 */ 672 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 673 ip6stat.ip6s_tooshort++; 674 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 675 goto bad; 676 } 677 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 678 if (m->m_len == m->m_pkthdr.len) { 679 m->m_len = sizeof(struct ip6_hdr) + plen; 680 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 681 } else 682 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 683 } 684 685 /* 686 * Forward if desirable. 687 */ 688 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 689 /* 690 * If we are acting as a multicast router, all 691 * incoming multicast packets are passed to the 692 * kernel-level multicast forwarding function. 693 * The packet is returned (relatively) intact; if 694 * ip6_mforward() returns a non-zero value, the packet 695 * must be discarded, else it may be accepted below. 696 */ 697 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 698 ip6stat.ip6s_cantforward++; 699 m_freem(m); 700 return; 701 } 702 if (!ours) { 703 m_freem(m); 704 return; 705 } 706 } else if (!ours) { 707 ip6_forward(m, srcrt); 708 return; 709 } 710 711 ip6 = mtod(m, struct ip6_hdr *); 712 713 /* 714 * Malicious party may be able to use IPv4 mapped addr to confuse 715 * tcp/udp stack and bypass security checks (act as if it was from 716 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 717 * 718 * For SIIT end node behavior, you may want to disable the check. 719 * However, you will become vulnerable to attacks using IPv4 mapped 720 * source. 721 */ 722 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 723 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 724 ip6stat.ip6s_badscope++; 725 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 726 goto bad; 727 } 728 729 /* 730 * Tell launch routine the next header 731 */ 732 ip6stat.ip6s_delivered++; 733 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 734 nest = 0; 735 736 while (nxt != IPPROTO_DONE) { 737 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 738 ip6stat.ip6s_toomanyhdr++; 739 goto bad; 740 } 741 742 /* 743 * protection against faulty packet - there should be 744 * more sanity checks in header chain processing. 745 */ 746 if (m->m_pkthdr.len < off) { 747 ip6stat.ip6s_tooshort++; 748 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 749 goto bad; 750 } 751 752 #ifdef IPSEC 753 /* 754 * enforce IPsec policy checking if we are seeing last header. 755 * note that we do not visit this with protocols with pcb layer 756 * code - like udp/tcp/raw ip. 757 */ 758 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 759 ipsec6_in_reject(m, NULL)) { 760 ipsec6stat.in_polvio++; 761 goto bad; 762 } 763 #endif 764 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 765 } 766 return; 767 bad: 768 m_freem(m); 769 } 770 771 /* 772 * set/grab in6_ifaddr correspond to IPv6 destination address. 773 * XXX backward compatibility wrapper 774 */ 775 static struct ip6aux * 776 ip6_setdstifaddr(m, ia6) 777 struct mbuf *m; 778 struct in6_ifaddr *ia6; 779 { 780 struct ip6aux *ip6a; 781 782 ip6a = ip6_addaux(m); 783 if (ip6a) 784 ip6a->ip6a_dstia6 = ia6; 785 return ip6a; /* NULL if failed to set */ 786 } 787 788 struct in6_ifaddr * 789 ip6_getdstifaddr(m) 790 struct mbuf *m; 791 { 792 struct ip6aux *ip6a; 793 794 ip6a = ip6_findaux(m); 795 if (ip6a) 796 return ip6a->ip6a_dstia6; 797 else 798 return NULL; 799 } 800 801 /* 802 * Hop-by-Hop options header processing. If a valid jumbo payload option is 803 * included, the real payload length will be stored in plenp. 804 */ 805 static int 806 ip6_hopopts_input(plenp, rtalertp, mp, offp) 807 u_int32_t *plenp; 808 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 809 struct mbuf **mp; 810 int *offp; 811 { 812 struct mbuf *m = *mp; 813 int off = *offp, hbhlen; 814 struct ip6_hbh *hbh; 815 u_int8_t *opt; 816 817 /* validation of the length of the header */ 818 #ifndef PULLDOWN_TEST 819 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 820 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 821 hbhlen = (hbh->ip6h_len + 1) << 3; 822 823 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 824 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 825 #else 826 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 827 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 828 if (hbh == NULL) { 829 ip6stat.ip6s_tooshort++; 830 return -1; 831 } 832 hbhlen = (hbh->ip6h_len + 1) << 3; 833 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 834 hbhlen); 835 if (hbh == NULL) { 836 ip6stat.ip6s_tooshort++; 837 return -1; 838 } 839 #endif 840 off += hbhlen; 841 hbhlen -= sizeof(struct ip6_hbh); 842 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 843 844 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 845 hbhlen, rtalertp, plenp) < 0) 846 return (-1); 847 848 *offp = off; 849 *mp = m; 850 return (0); 851 } 852 853 /* 854 * Search header for all Hop-by-hop options and process each option. 855 * This function is separate from ip6_hopopts_input() in order to 856 * handle a case where the sending node itself process its hop-by-hop 857 * options header. In such a case, the function is called from ip6_output(). 858 * 859 * The function assumes that hbh header is located right after the IPv6 header 860 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 861 * opthead + hbhlen is located in continuous memory region. 862 */ 863 int 864 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 865 struct mbuf *m; 866 u_int8_t *opthead; 867 int hbhlen; 868 u_int32_t *rtalertp; 869 u_int32_t *plenp; 870 { 871 struct ip6_hdr *ip6; 872 int optlen = 0; 873 u_int8_t *opt = opthead; 874 u_int16_t rtalert_val; 875 u_int32_t jumboplen; 876 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 877 878 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 879 switch (*opt) { 880 case IP6OPT_PAD1: 881 optlen = 1; 882 break; 883 case IP6OPT_PADN: 884 if (hbhlen < IP6OPT_MINLEN) { 885 ip6stat.ip6s_toosmall++; 886 goto bad; 887 } 888 optlen = *(opt + 1) + 2; 889 break; 890 case IP6OPT_ROUTER_ALERT: 891 /* XXX may need check for alignment */ 892 if (hbhlen < IP6OPT_RTALERT_LEN) { 893 ip6stat.ip6s_toosmall++; 894 goto bad; 895 } 896 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 897 /* XXX stat */ 898 icmp6_error(m, ICMP6_PARAM_PROB, 899 ICMP6_PARAMPROB_HEADER, 900 erroff + opt + 1 - opthead); 901 return (-1); 902 } 903 optlen = IP6OPT_RTALERT_LEN; 904 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 905 *rtalertp = ntohs(rtalert_val); 906 break; 907 case IP6OPT_JUMBO: 908 /* XXX may need check for alignment */ 909 if (hbhlen < IP6OPT_JUMBO_LEN) { 910 ip6stat.ip6s_toosmall++; 911 goto bad; 912 } 913 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 914 /* XXX stat */ 915 icmp6_error(m, ICMP6_PARAM_PROB, 916 ICMP6_PARAMPROB_HEADER, 917 erroff + opt + 1 - opthead); 918 return (-1); 919 } 920 optlen = IP6OPT_JUMBO_LEN; 921 922 /* 923 * IPv6 packets that have non 0 payload length 924 * must not contain a jumbo payload option. 925 */ 926 ip6 = mtod(m, struct ip6_hdr *); 927 if (ip6->ip6_plen) { 928 ip6stat.ip6s_badoptions++; 929 icmp6_error(m, ICMP6_PARAM_PROB, 930 ICMP6_PARAMPROB_HEADER, 931 erroff + opt - opthead); 932 return (-1); 933 } 934 935 /* 936 * We may see jumbolen in unaligned location, so 937 * we'd need to perform bcopy(). 938 */ 939 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 940 jumboplen = (u_int32_t)htonl(jumboplen); 941 942 #if 1 943 /* 944 * if there are multiple jumbo payload options, 945 * *plenp will be non-zero and the packet will be 946 * rejected. 947 * the behavior may need some debate in ipngwg - 948 * multiple options does not make sense, however, 949 * there's no explicit mention in specification. 950 */ 951 if (*plenp != 0) { 952 ip6stat.ip6s_badoptions++; 953 icmp6_error(m, ICMP6_PARAM_PROB, 954 ICMP6_PARAMPROB_HEADER, 955 erroff + opt + 2 - opthead); 956 return (-1); 957 } 958 #endif 959 960 /* 961 * jumbo payload length must be larger than 65535. 962 */ 963 if (jumboplen <= IPV6_MAXPACKET) { 964 ip6stat.ip6s_badoptions++; 965 icmp6_error(m, ICMP6_PARAM_PROB, 966 ICMP6_PARAMPROB_HEADER, 967 erroff + opt + 2 - opthead); 968 return (-1); 969 } 970 *plenp = jumboplen; 971 972 break; 973 default: /* unknown option */ 974 if (hbhlen < IP6OPT_MINLEN) { 975 ip6stat.ip6s_toosmall++; 976 goto bad; 977 } 978 optlen = ip6_unknown_opt(opt, m, 979 erroff + opt - opthead); 980 if (optlen == -1) 981 return (-1); 982 optlen += 2; 983 break; 984 } 985 } 986 987 return (0); 988 989 bad: 990 m_freem(m); 991 return (-1); 992 } 993 994 /* 995 * Unknown option processing. 996 * The third argument `off' is the offset from the IPv6 header to the option, 997 * which is necessary if the IPv6 header the and option header and IPv6 header 998 * is not continuous in order to return an ICMPv6 error. 999 */ 1000 int 1001 ip6_unknown_opt(optp, m, off) 1002 u_int8_t *optp; 1003 struct mbuf *m; 1004 int off; 1005 { 1006 struct ip6_hdr *ip6; 1007 1008 switch (IP6OPT_TYPE(*optp)) { 1009 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1010 return ((int)*(optp + 1)); 1011 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1012 m_freem(m); 1013 return (-1); 1014 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1015 ip6stat.ip6s_badoptions++; 1016 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1017 return (-1); 1018 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1019 ip6stat.ip6s_badoptions++; 1020 ip6 = mtod(m, struct ip6_hdr *); 1021 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1022 (m->m_flags & (M_BCAST|M_MCAST))) 1023 m_freem(m); 1024 else 1025 icmp6_error(m, ICMP6_PARAM_PROB, 1026 ICMP6_PARAMPROB_OPTION, off); 1027 return (-1); 1028 } 1029 1030 m_freem(m); /* XXX: NOTREACHED */ 1031 return (-1); 1032 } 1033 1034 /* 1035 * Create the "control" list for this pcb. 1036 * The function will not modify mbuf chain at all. 1037 * 1038 * with KAME mbuf chain restriction: 1039 * The routine will be called from upper layer handlers like tcp6_input(). 1040 * Thus the routine assumes that the caller (tcp6_input) have already 1041 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1042 * very first mbuf on the mbuf chain. 1043 */ 1044 void 1045 ip6_savecontrol(in6p, m, mp) 1046 struct inpcb *in6p; 1047 struct mbuf *m, **mp; 1048 { 1049 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1050 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1051 1052 #ifdef SO_TIMESTAMP 1053 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1054 struct timeval tv; 1055 1056 microtime(&tv); 1057 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1058 SCM_TIMESTAMP, SOL_SOCKET); 1059 if (*mp) 1060 mp = &(*mp)->m_next; 1061 } 1062 #endif 1063 1064 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1065 return; 1066 1067 /* RFC 2292 sec. 5 */ 1068 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1069 struct in6_pktinfo pi6; 1070 1071 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1072 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1073 pi6.ipi6_ifindex = 1074 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1075 1076 *mp = sbcreatecontrol((caddr_t) &pi6, 1077 sizeof(struct in6_pktinfo), 1078 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1079 if (*mp) 1080 mp = &(*mp)->m_next; 1081 } 1082 1083 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1084 int hlim = ip6->ip6_hlim & 0xff; 1085 1086 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1087 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1088 if (*mp) 1089 mp = &(*mp)->m_next; 1090 } 1091 1092 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1093 u_int32_t flowinfo; 1094 int tclass; 1095 1096 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1097 flowinfo >>= 20; 1098 1099 tclass = flowinfo & 0xff; 1100 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1101 IPV6_TCLASS, IPPROTO_IPV6); 1102 if (*mp) 1103 mp = &(*mp)->m_next; 1104 } 1105 1106 /* 1107 * IPV6_HOPOPTS socket option. Recall that we required super-user 1108 * privilege for the option (see ip6_ctloutput), but it might be too 1109 * strict, since there might be some hop-by-hop options which can be 1110 * returned to normal user. 1111 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1112 */ 1113 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1114 /* 1115 * Check if a hop-by-hop options header is contatined in the 1116 * received packet, and if so, store the options as ancillary 1117 * data. Note that a hop-by-hop options header must be 1118 * just after the IPv6 header, which is assured through the 1119 * IPv6 input processing. 1120 */ 1121 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1122 struct ip6_hbh *hbh; 1123 int hbhlen = 0; 1124 #ifdef PULLDOWN_TEST 1125 struct mbuf *ext; 1126 #endif 1127 1128 #ifndef PULLDOWN_TEST 1129 hbh = (struct ip6_hbh *)(ip6 + 1); 1130 hbhlen = (hbh->ip6h_len + 1) << 3; 1131 #else 1132 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1133 ip6->ip6_nxt); 1134 if (ext == NULL) { 1135 ip6stat.ip6s_tooshort++; 1136 return; 1137 } 1138 hbh = mtod(ext, struct ip6_hbh *); 1139 hbhlen = (hbh->ip6h_len + 1) << 3; 1140 if (hbhlen != ext->m_len) { 1141 m_freem(ext); 1142 ip6stat.ip6s_tooshort++; 1143 return; 1144 } 1145 #endif 1146 1147 /* 1148 * XXX: We copy the whole header even if a 1149 * jumbo payload option is included, the option which 1150 * is to be removed before returning according to 1151 * RFC2292. 1152 * Note: this constraint is removed in RFC3542 1153 */ 1154 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1155 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1156 IPPROTO_IPV6); 1157 if (*mp) 1158 mp = &(*mp)->m_next; 1159 #ifdef PULLDOWN_TEST 1160 m_freem(ext); 1161 #endif 1162 } 1163 } 1164 1165 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1166 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1167 1168 /* 1169 * Search for destination options headers or routing 1170 * header(s) through the header chain, and stores each 1171 * header as ancillary data. 1172 * Note that the order of the headers remains in 1173 * the chain of ancillary data. 1174 */ 1175 while (1) { /* is explicit loop prevention necessary? */ 1176 struct ip6_ext *ip6e = NULL; 1177 int elen; 1178 #ifdef PULLDOWN_TEST 1179 struct mbuf *ext = NULL; 1180 #endif 1181 1182 /* 1183 * if it is not an extension header, don't try to 1184 * pull it from the chain. 1185 */ 1186 switch (nxt) { 1187 case IPPROTO_DSTOPTS: 1188 case IPPROTO_ROUTING: 1189 case IPPROTO_HOPOPTS: 1190 case IPPROTO_AH: /* is it possible? */ 1191 break; 1192 default: 1193 goto loopend; 1194 } 1195 1196 #ifndef PULLDOWN_TEST 1197 if (off + sizeof(*ip6e) > m->m_len) 1198 goto loopend; 1199 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1200 if (nxt == IPPROTO_AH) 1201 elen = (ip6e->ip6e_len + 2) << 2; 1202 else 1203 elen = (ip6e->ip6e_len + 1) << 3; 1204 if (off + elen > m->m_len) 1205 goto loopend; 1206 #else 1207 ext = ip6_pullexthdr(m, off, nxt); 1208 if (ext == NULL) { 1209 ip6stat.ip6s_tooshort++; 1210 return; 1211 } 1212 ip6e = mtod(ext, struct ip6_ext *); 1213 if (nxt == IPPROTO_AH) 1214 elen = (ip6e->ip6e_len + 2) << 2; 1215 else 1216 elen = (ip6e->ip6e_len + 1) << 3; 1217 if (elen != ext->m_len) { 1218 m_freem(ext); 1219 ip6stat.ip6s_tooshort++; 1220 return; 1221 } 1222 #endif 1223 1224 switch (nxt) { 1225 case IPPROTO_DSTOPTS: 1226 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1227 break; 1228 1229 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1230 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1231 IPPROTO_IPV6); 1232 if (*mp) 1233 mp = &(*mp)->m_next; 1234 break; 1235 case IPPROTO_ROUTING: 1236 if (!in6p->in6p_flags & IN6P_RTHDR) 1237 break; 1238 1239 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1240 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1241 IPPROTO_IPV6); 1242 if (*mp) 1243 mp = &(*mp)->m_next; 1244 break; 1245 case IPPROTO_HOPOPTS: 1246 case IPPROTO_AH: /* is it possible? */ 1247 break; 1248 1249 default: 1250 /* 1251 * other cases have been filtered in the above. 1252 * none will visit this case. here we supply 1253 * the code just in case (nxt overwritten or 1254 * other cases). 1255 */ 1256 #ifdef PULLDOWN_TEST 1257 m_freem(ext); 1258 #endif 1259 goto loopend; 1260 1261 } 1262 1263 /* proceed with the next header. */ 1264 off += elen; 1265 nxt = ip6e->ip6e_nxt; 1266 ip6e = NULL; 1267 #ifdef PULLDOWN_TEST 1268 m_freem(ext); 1269 ext = NULL; 1270 #endif 1271 } 1272 loopend: 1273 ; 1274 } 1275 1276 #undef IS2292 1277 } 1278 1279 void 1280 ip6_notify_pmtu(in6p, dst, mtu) 1281 struct inpcb *in6p; 1282 struct sockaddr_in6 *dst; 1283 u_int32_t *mtu; 1284 { 1285 struct socket *so; 1286 struct mbuf *m_mtu; 1287 struct ip6_mtuinfo mtuctl; 1288 1289 so = in6p->inp_socket; 1290 1291 if (mtu == NULL) 1292 return; 1293 1294 #ifdef DIAGNOSTIC 1295 if (so == NULL) /* I believe this is impossible */ 1296 panic("ip6_notify_pmtu: socket is NULL"); 1297 #endif 1298 1299 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1300 mtuctl.ip6m_mtu = *mtu; 1301 mtuctl.ip6m_addr = *dst; 1302 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1303 return; 1304 1305 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1306 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1307 return; 1308 1309 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1310 == 0) { 1311 m_freem(m_mtu); 1312 /* XXX: should count statistics */ 1313 } else 1314 sorwakeup(so); 1315 1316 return; 1317 } 1318 1319 #ifdef PULLDOWN_TEST 1320 /* 1321 * pull single extension header from mbuf chain. returns single mbuf that 1322 * contains the result, or NULL on error. 1323 */ 1324 static struct mbuf * 1325 ip6_pullexthdr(m, off, nxt) 1326 struct mbuf *m; 1327 size_t off; 1328 int nxt; 1329 { 1330 struct ip6_ext ip6e; 1331 size_t elen; 1332 struct mbuf *n; 1333 1334 #ifdef DIAGNOSTIC 1335 switch (nxt) { 1336 case IPPROTO_DSTOPTS: 1337 case IPPROTO_ROUTING: 1338 case IPPROTO_HOPOPTS: 1339 case IPPROTO_AH: /* is it possible? */ 1340 break; 1341 default: 1342 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1343 } 1344 #endif 1345 1346 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1347 if (nxt == IPPROTO_AH) 1348 elen = (ip6e.ip6e_len + 2) << 2; 1349 else 1350 elen = (ip6e.ip6e_len + 1) << 3; 1351 1352 MGET(n, M_DONTWAIT, MT_DATA); 1353 if (n && elen >= MLEN) { 1354 MCLGET(n, M_DONTWAIT); 1355 if ((n->m_flags & M_EXT) == 0) { 1356 m_free(n); 1357 n = NULL; 1358 } 1359 } 1360 if (!n) 1361 return NULL; 1362 1363 n->m_len = 0; 1364 if (elen >= M_TRAILINGSPACE(n)) { 1365 m_free(n); 1366 return NULL; 1367 } 1368 1369 m_copydata(m, off, elen, mtod(n, caddr_t)); 1370 n->m_len = elen; 1371 return n; 1372 } 1373 #endif 1374 1375 /* 1376 * Get pointer to the previous header followed by the header 1377 * currently processed. 1378 * XXX: This function supposes that 1379 * M includes all headers, 1380 * the next header field and the header length field of each header 1381 * are valid, and 1382 * the sum of each header length equals to OFF. 1383 * Because of these assumptions, this function must be called very 1384 * carefully. Moreover, it will not be used in the near future when 1385 * we develop `neater' mechanism to process extension headers. 1386 */ 1387 char * 1388 ip6_get_prevhdr(m, off) 1389 struct mbuf *m; 1390 int off; 1391 { 1392 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1393 1394 if (off == sizeof(struct ip6_hdr)) 1395 return (&ip6->ip6_nxt); 1396 else { 1397 int len, nxt; 1398 struct ip6_ext *ip6e = NULL; 1399 1400 nxt = ip6->ip6_nxt; 1401 len = sizeof(struct ip6_hdr); 1402 while (len < off) { 1403 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1404 1405 switch (nxt) { 1406 case IPPROTO_FRAGMENT: 1407 len += sizeof(struct ip6_frag); 1408 break; 1409 case IPPROTO_AH: 1410 len += (ip6e->ip6e_len + 2) << 2; 1411 break; 1412 default: 1413 len += (ip6e->ip6e_len + 1) << 3; 1414 break; 1415 } 1416 nxt = ip6e->ip6e_nxt; 1417 } 1418 if (ip6e) 1419 return (&ip6e->ip6e_nxt); 1420 else 1421 return NULL; 1422 } 1423 } 1424 1425 /* 1426 * get next header offset. m will be retained. 1427 */ 1428 int 1429 ip6_nexthdr(m, off, proto, nxtp) 1430 struct mbuf *m; 1431 int off; 1432 int proto; 1433 int *nxtp; 1434 { 1435 struct ip6_hdr ip6; 1436 struct ip6_ext ip6e; 1437 struct ip6_frag fh; 1438 1439 /* just in case */ 1440 if (m == NULL) 1441 panic("ip6_nexthdr: m == NULL"); 1442 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1443 return -1; 1444 1445 switch (proto) { 1446 case IPPROTO_IPV6: 1447 if (m->m_pkthdr.len < off + sizeof(ip6)) 1448 return -1; 1449 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1450 if (nxtp) 1451 *nxtp = ip6.ip6_nxt; 1452 off += sizeof(ip6); 1453 return off; 1454 1455 case IPPROTO_FRAGMENT: 1456 /* 1457 * terminate parsing if it is not the first fragment, 1458 * it does not make sense to parse through it. 1459 */ 1460 if (m->m_pkthdr.len < off + sizeof(fh)) 1461 return -1; 1462 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1463 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1464 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1465 return -1; 1466 if (nxtp) 1467 *nxtp = fh.ip6f_nxt; 1468 off += sizeof(struct ip6_frag); 1469 return off; 1470 1471 case IPPROTO_AH: 1472 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1473 return -1; 1474 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1475 if (nxtp) 1476 *nxtp = ip6e.ip6e_nxt; 1477 off += (ip6e.ip6e_len + 2) << 2; 1478 return off; 1479 1480 case IPPROTO_HOPOPTS: 1481 case IPPROTO_ROUTING: 1482 case IPPROTO_DSTOPTS: 1483 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1484 return -1; 1485 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1486 if (nxtp) 1487 *nxtp = ip6e.ip6e_nxt; 1488 off += (ip6e.ip6e_len + 1) << 3; 1489 return off; 1490 1491 case IPPROTO_NONE: 1492 case IPPROTO_ESP: 1493 case IPPROTO_IPCOMP: 1494 /* give up */ 1495 return -1; 1496 1497 default: 1498 return -1; 1499 } 1500 1501 return -1; 1502 } 1503 1504 /* 1505 * get offset for the last header in the chain. m will be kept untainted. 1506 */ 1507 int 1508 ip6_lasthdr(m, off, proto, nxtp) 1509 struct mbuf *m; 1510 int off; 1511 int proto; 1512 int *nxtp; 1513 { 1514 int newoff; 1515 int nxt; 1516 1517 if (!nxtp) { 1518 nxt = -1; 1519 nxtp = &nxt; 1520 } 1521 while (1) { 1522 newoff = ip6_nexthdr(m, off, proto, nxtp); 1523 if (newoff < 0) 1524 return off; 1525 else if (newoff < off) 1526 return -1; /* invalid */ 1527 else if (newoff == off) 1528 return newoff; 1529 1530 off = newoff; 1531 proto = *nxtp; 1532 } 1533 } 1534 1535 struct ip6aux * 1536 ip6_addaux(m) 1537 struct mbuf *m; 1538 { 1539 struct m_tag *mtag; 1540 1541 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1542 if (!mtag) { 1543 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1544 M_NOWAIT); 1545 if (mtag) { 1546 m_tag_prepend(m, mtag); 1547 bzero(mtag + 1, sizeof(struct ip6aux)); 1548 } 1549 } 1550 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1551 } 1552 1553 struct ip6aux * 1554 ip6_findaux(m) 1555 struct mbuf *m; 1556 { 1557 struct m_tag *mtag; 1558 1559 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1560 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1561 } 1562 1563 void 1564 ip6_delaux(m) 1565 struct mbuf *m; 1566 { 1567 struct m_tag *mtag; 1568 1569 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1570 if (mtag) 1571 m_tag_delete(m, mtag); 1572 } 1573 1574 /* 1575 * System control for IP6 1576 */ 1577 1578 u_char inet6ctlerrmap[PRC_NCMDS] = { 1579 0, 0, 0, 0, 1580 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1581 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1582 EMSGSIZE, EHOSTUNREACH, 0, 0, 1583 0, 0, 0, 0, 1584 ENOPROTOOPT 1585 }; 1586