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sys/netinet6/ip6_input.c
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1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1988, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD: releng/7.3/sys/netinet6/ip6_input.c 196546 2009-08-25 16:56:33Z bz $"); 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 #include "opt_ipsec.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/proc.h> 75 #include <sys/domain.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/errno.h> 80 #include <sys/time.h> 81 #include <sys/kernel.h> 82 #include <sys/syslog.h> 83 84 #include <net/if.h> 85 #include <net/if_types.h> 86 #include <net/if_dl.h> 87 #include <net/route.h> 88 #include <net/netisr.h> 89 #include <net/pfil.h> 90 91 #include <netinet/in.h> 92 #include <netinet/in_systm.h> 93 #ifdef INET 94 #include <netinet/ip.h> 95 #include <netinet/ip_icmp.h> 96 #endif /* INET */ 97 #include <netinet/ip6.h> 98 #include <netinet6/in6_var.h> 99 #include <netinet6/ip6_var.h> 100 #include <netinet/in_pcb.h> 101 #include <netinet/icmp6.h> 102 #include <netinet6/scope6_var.h> 103 #include <netinet6/in6_ifattach.h> 104 #include <netinet6/nd6.h> 105 106 #ifdef IPSEC 107 #include <netipsec/ipsec.h> 108 #include <netinet6/ip6_ipsec.h> 109 #include <netipsec/ipsec6.h> 110 #endif /* IPSEC */ 111 112 #include <netinet6/ip6protosw.h> 113 114 extern struct domain inet6domain; 115 116 u_char ip6_protox[IPPROTO_MAX]; 117 static struct ifqueue ip6intrq; 118 static int ip6qmaxlen = IFQ_MAXLEN; 119 struct in6_ifaddr *in6_ifaddr; 120 121 extern struct callout in6_tmpaddrtimer_ch; 122 123 struct pfil_head inet6_pfil_hook; 124 125 struct ip6stat ip6stat; 126 127 static void ip6_init2(void *); 128 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 129 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 130 #ifdef PULLDOWN_TEST 131 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 132 #endif 133 134 /* 135 * IP6 initialization: fill in IP6 protocol switch table. 136 * All protocols not implemented in kernel go to raw IP6 protocol handler. 137 */ 138 void 139 ip6_init(void) 140 { 141 struct ip6protosw *pr; 142 int i; 143 144 #ifdef DIAGNOSTIC 145 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 146 panic("sizeof(protosw) != sizeof(ip6protosw)"); 147 #endif 148 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 149 if (pr == NULL) 150 panic("ip6_init"); 151 152 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ 153 for (i = 0; i < IPPROTO_MAX; i++) 154 ip6_protox[i] = pr - inet6sw; 155 /* 156 * Cycle through IP protocols and put them into the appropriate place 157 * in ip6_protox[]. 158 */ 159 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 160 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 161 if (pr->pr_domain->dom_family == PF_INET6 && 162 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 163 /* Be careful to only index valid IP protocols. */ 164 if (pr->pr_protocol < IPPROTO_MAX) 165 ip6_protox[pr->pr_protocol] = pr - inet6sw; 166 } 167 168 /* Initialize packet filter hooks. */ 169 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 170 inet6_pfil_hook.ph_af = AF_INET6; 171 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 172 printf("%s: WARNING: unable to register pfil hook, " 173 "error %d\n", __func__, i); 174 175 ip6intrq.ifq_maxlen = ip6qmaxlen; 176 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 177 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 178 scope6_init(); 179 addrsel_policy_init(); 180 nd6_init(); 181 frag6_init(); 182 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 183 } 184 185 static void 186 ip6_init2(void *dummy) 187 { 188 189 /* nd6_timer_init */ 190 callout_init(&nd6_timer_ch, 0); 191 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 192 193 /* timer for regeneranation of temporary addresses randomize ID */ 194 callout_init(&in6_tmpaddrtimer_ch, 0); 195 callout_reset(&in6_tmpaddrtimer_ch, 196 (ip6_temp_preferred_lifetime - ip6_desync_factor - 197 ip6_temp_regen_advance) * hz, 198 in6_tmpaddrtimer, NULL); 199 } 200 201 /* cheat */ 202 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 203 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 204 205 extern struct route_in6 ip6_forward_rt; 206 207 void 208 ip6_input(struct mbuf *m) 209 { 210 struct ip6_hdr *ip6; 211 int off = sizeof(struct ip6_hdr), nest; 212 u_int32_t plen; 213 u_int32_t rtalert = ~0; 214 int nxt, ours = 0; 215 struct ifnet *deliverifp = NULL; 216 struct in6_addr odst; 217 int srcrt = 0; 218 219 GIANT_REQUIRED; /* XXX for now */ 220 221 #ifdef IPSEC 222 /* 223 * should the inner packet be considered authentic? 224 * see comment in ah4_input(). 225 * NB: m cannot be NULL when passed to the input routine 226 */ 227 228 m->m_flags &= ~M_AUTHIPHDR; 229 m->m_flags &= ~M_AUTHIPDGM; 230 231 #endif /* IPSEC */ 232 233 /* 234 * make sure we don't have onion peering information into m_tag. 235 */ 236 ip6_delaux(m); 237 238 /* 239 * mbuf statistics 240 */ 241 if (m->m_flags & M_EXT) { 242 if (m->m_next) 243 ip6stat.ip6s_mext2m++; 244 else 245 ip6stat.ip6s_mext1++; 246 } else { 247 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 248 if (m->m_next) { 249 if (m->m_flags & M_LOOP) { 250 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 251 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 252 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 253 else 254 ip6stat.ip6s_m2m[0]++; 255 } else 256 ip6stat.ip6s_m1++; 257 #undef M2MMAX 258 } 259 260 /* drop the packet if IPv6 operation is disabled on the IF */ 261 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 262 m_freem(m); 263 return; 264 } 265 266 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 267 ip6stat.ip6s_total++; 268 269 #ifndef PULLDOWN_TEST 270 /* 271 * L2 bridge code and some other code can return mbuf chain 272 * that does not conform to KAME requirement. too bad. 273 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 274 */ 275 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 276 struct mbuf *n; 277 278 MGETHDR(n, M_DONTWAIT, MT_HEADER); 279 if (n) 280 M_MOVE_PKTHDR(n, m); 281 if (n && n->m_pkthdr.len > MHLEN) { 282 MCLGET(n, M_DONTWAIT); 283 if ((n->m_flags & M_EXT) == 0) { 284 m_freem(n); 285 n = NULL; 286 } 287 } 288 if (n == NULL) { 289 m_freem(m); 290 return; /* ENOBUFS */ 291 } 292 293 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 294 n->m_len = n->m_pkthdr.len; 295 m_freem(m); 296 m = n; 297 } 298 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 299 #endif 300 301 if (m->m_len < sizeof(struct ip6_hdr)) { 302 struct ifnet *inifp; 303 inifp = m->m_pkthdr.rcvif; 304 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 305 ip6stat.ip6s_toosmall++; 306 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 307 return; 308 } 309 } 310 311 ip6 = mtod(m, struct ip6_hdr *); 312 313 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 314 ip6stat.ip6s_badvers++; 315 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 316 goto bad; 317 } 318 319 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 320 321 /* 322 * Check against address spoofing/corruption. 323 */ 324 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 325 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 326 /* 327 * XXX: "badscope" is not very suitable for a multicast source. 328 */ 329 ip6stat.ip6s_badscope++; 330 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 331 goto bad; 332 } 333 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 334 !(m->m_flags & M_LOOP)) { 335 /* 336 * In this case, the packet should come from the loopback 337 * interface. However, we cannot just check the if_flags, 338 * because ip6_mloopback() passes the "actual" interface 339 * as the outgoing/incoming interface. 340 */ 341 ip6stat.ip6s_badscope++; 342 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 343 goto bad; 344 } 345 346 #ifdef ALTQ 347 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 348 /* packet is dropped by traffic conditioner */ 349 return; 350 } 351 #endif 352 /* 353 * The following check is not documented in specs. A malicious 354 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 355 * and bypass security checks (act as if it was from 127.0.0.1 by using 356 * IPv6 src ::ffff:127.0.0.1). Be cautious. 357 * 358 * This check chokes if we are in an SIIT cloud. As none of BSDs 359 * support IPv4-less kernel compilation, we cannot support SIIT 360 * environment at all. So, it makes more sense for us to reject any 361 * malicious packets for non-SIIT environment, than try to do a 362 * partial support for SIIT environment. 363 */ 364 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 365 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 366 ip6stat.ip6s_badscope++; 367 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 368 goto bad; 369 } 370 #if 0 371 /* 372 * Reject packets with IPv4 compatible addresses (auto tunnel). 373 * 374 * The code forbids auto tunnel relay case in RFC1933 (the check is 375 * stronger than RFC1933). We may want to re-enable it if mech-xx 376 * is revised to forbid relaying case. 377 */ 378 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 379 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 380 ip6stat.ip6s_badscope++; 381 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 382 goto bad; 383 } 384 #endif 385 386 /* 387 * Run through list of hooks for input packets. 388 * 389 * NB: Beware of the destination address changing 390 * (e.g. by NAT rewriting). When this happens, 391 * tell ip6_forward to do the right thing. 392 */ 393 odst = ip6->ip6_dst; 394 395 /* Jump over all PFIL processing if hooks are not active. */ 396 if (!PFIL_HOOKED(&inet6_pfil_hook)) 397 goto passin; 398 399 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 400 return; 401 if (m == NULL) /* consumed by filter */ 402 return; 403 ip6 = mtod(m, struct ip6_hdr *); 404 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 405 406 passin: 407 /* 408 * Disambiguate address scope zones (if there is ambiguity). 409 * We first make sure that the original source or destination address 410 * is not in our internal form for scoped addresses. Such addresses 411 * are not necessarily invalid spec-wise, but we cannot accept them due 412 * to the usage conflict. 413 * in6_setscope() then also checks and rejects the cases where src or 414 * dst are the loopback address and the receiving interface 415 * is not loopback. 416 */ 417 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 418 ip6stat.ip6s_badscope++; /* XXX */ 419 goto bad; 420 } 421 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 422 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 423 ip6stat.ip6s_badscope++; 424 goto bad; 425 } 426 427 /* 428 * Multicast check 429 */ 430 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 431 struct in6_multi *in6m = 0; 432 433 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 434 /* 435 * See if we belong to the destination multicast group on the 436 * arrival interface. 437 */ 438 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 439 if (in6m) 440 ours = 1; 441 else if (!ip6_mrouter) { 442 ip6stat.ip6s_notmember++; 443 ip6stat.ip6s_cantforward++; 444 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 445 goto bad; 446 } 447 deliverifp = m->m_pkthdr.rcvif; 448 goto hbhcheck; 449 } 450 451 /* 452 * Unicast check 453 */ 454 if (ip6_forward_rt.ro_rt != NULL && 455 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 456 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 457 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 458 ip6stat.ip6s_forward_cachehit++; 459 else { 460 struct sockaddr_in6 *dst6; 461 462 if (ip6_forward_rt.ro_rt) { 463 /* route is down or destination is different */ 464 ip6stat.ip6s_forward_cachemiss++; 465 RTFREE(ip6_forward_rt.ro_rt); 466 ip6_forward_rt.ro_rt = 0; 467 } 468 469 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 470 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 471 dst6->sin6_len = sizeof(struct sockaddr_in6); 472 dst6->sin6_family = AF_INET6; 473 dst6->sin6_addr = ip6->ip6_dst; 474 475 rtalloc((struct route *)&ip6_forward_rt); 476 } 477 478 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 479 480 /* 481 * Accept the packet if the forwarding interface to the destination 482 * according to the routing table is the loopback interface, 483 * unless the associated route has a gateway. 484 * Note that this approach causes to accept a packet if there is a 485 * route to the loopback interface for the destination of the packet. 486 * But we think it's even useful in some situations, e.g. when using 487 * a special daemon which wants to intercept the packet. 488 * 489 * XXX: some OSes automatically make a cloned route for the destination 490 * of an outgoing packet. If the outgoing interface of the packet 491 * is a loopback one, the kernel would consider the packet to be 492 * accepted, even if we have no such address assinged on the interface. 493 * We check the cloned flag of the route entry to reject such cases, 494 * assuming that route entries for our own addresses are not made by 495 * cloning (it should be true because in6_addloop explicitly installs 496 * the host route). However, we might have to do an explicit check 497 * while it would be less efficient. Or, should we rather install a 498 * reject route for such a case? 499 */ 500 if (ip6_forward_rt.ro_rt && 501 (ip6_forward_rt.ro_rt->rt_flags & 502 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 503 #ifdef RTF_WASCLONED 504 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 505 #endif 506 #ifdef RTF_CLONED 507 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 508 #endif 509 #if 0 510 /* 511 * The check below is redundant since the comparison of 512 * the destination and the key of the rtentry has 513 * already done through looking up the routing table. 514 */ 515 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 516 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 517 #endif 518 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 519 struct in6_ifaddr *ia6 = 520 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 521 522 /* 523 * record address information into m_tag. 524 */ 525 (void)ip6_setdstifaddr(m, ia6); 526 527 /* 528 * packets to a tentative, duplicated, or somehow invalid 529 * address must not be accepted. 530 */ 531 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 532 /* this address is ready */ 533 ours = 1; 534 deliverifp = ia6->ia_ifp; /* correct? */ 535 /* Count the packet in the ip address stats */ 536 ia6->ia_ifa.if_ipackets++; 537 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 538 goto hbhcheck; 539 } else { 540 char ip6bufs[INET6_ADDRSTRLEN]; 541 char ip6bufd[INET6_ADDRSTRLEN]; 542 /* address is not ready, so discard the packet. */ 543 nd6log((LOG_INFO, 544 "ip6_input: packet to an unready address %s->%s\n", 545 ip6_sprintf(ip6bufs, &ip6->ip6_src), 546 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 547 548 goto bad; 549 } 550 } 551 552 /* 553 * FAITH (Firewall Aided Internet Translator) 554 */ 555 if (ip6_keepfaith) { 556 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 557 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 558 /* XXX do we need more sanity checks? */ 559 ours = 1; 560 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 561 goto hbhcheck; 562 } 563 } 564 565 /* 566 * Now there is no reason to process the packet if it's not our own 567 * and we're not a router. 568 */ 569 if (!ip6_forwarding) { 570 ip6stat.ip6s_cantforward++; 571 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 572 goto bad; 573 } 574 575 hbhcheck: 576 /* 577 * record address information into m_tag, if we don't have one yet. 578 * note that we are unable to record it, if the address is not listed 579 * as our interface address (e.g. multicast addresses, addresses 580 * within FAITH prefixes and such). 581 */ 582 if (deliverifp && !ip6_getdstifaddr(m)) { 583 struct in6_ifaddr *ia6; 584 585 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 586 if (ia6) { 587 if (!ip6_setdstifaddr(m, ia6)) { 588 /* 589 * XXX maybe we should drop the packet here, 590 * as we could not provide enough information 591 * to the upper layers. 592 */ 593 } 594 } 595 } 596 597 /* 598 * Process Hop-by-Hop options header if it's contained. 599 * m may be modified in ip6_hopopts_input(). 600 * If a JumboPayload option is included, plen will also be modified. 601 */ 602 plen = (u_int32_t)ntohs(ip6->ip6_plen); 603 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 604 struct ip6_hbh *hbh; 605 606 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 607 #if 0 /*touches NULL pointer*/ 608 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 609 #endif 610 return; /* m have already been freed */ 611 } 612 613 /* adjust pointer */ 614 ip6 = mtod(m, struct ip6_hdr *); 615 616 /* 617 * if the payload length field is 0 and the next header field 618 * indicates Hop-by-Hop Options header, then a Jumbo Payload 619 * option MUST be included. 620 */ 621 if (ip6->ip6_plen == 0 && plen == 0) { 622 /* 623 * Note that if a valid jumbo payload option is 624 * contained, ip6_hopopts_input() must set a valid 625 * (non-zero) payload length to the variable plen. 626 */ 627 ip6stat.ip6s_badoptions++; 628 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 629 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 630 icmp6_error(m, ICMP6_PARAM_PROB, 631 ICMP6_PARAMPROB_HEADER, 632 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 633 return; 634 } 635 #ifndef PULLDOWN_TEST 636 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 637 hbh = (struct ip6_hbh *)(ip6 + 1); 638 #else 639 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 640 sizeof(struct ip6_hbh)); 641 if (hbh == NULL) { 642 ip6stat.ip6s_tooshort++; 643 return; 644 } 645 #endif 646 nxt = hbh->ip6h_nxt; 647 648 /* 649 * If we are acting as a router and the packet contains a 650 * router alert option, see if we know the option value. 651 * Currently, we only support the option value for MLD, in which 652 * case we should pass the packet to the multicast routing 653 * daemon. 654 */ 655 if (rtalert != ~0 && ip6_forwarding) { 656 switch (rtalert) { 657 case IP6OPT_RTALERT_MLD: 658 ours = 1; 659 break; 660 default: 661 /* 662 * RFC2711 requires unrecognized values must be 663 * silently ignored. 664 */ 665 break; 666 } 667 } 668 } else 669 nxt = ip6->ip6_nxt; 670 671 /* 672 * Check that the amount of data in the buffers 673 * is as at least much as the IPv6 header would have us expect. 674 * Trim mbufs if longer than we expect. 675 * Drop packet if shorter than we expect. 676 */ 677 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 678 ip6stat.ip6s_tooshort++; 679 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 680 goto bad; 681 } 682 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 683 if (m->m_len == m->m_pkthdr.len) { 684 m->m_len = sizeof(struct ip6_hdr) + plen; 685 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 686 } else 687 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 688 } 689 690 /* 691 * Forward if desirable. 692 */ 693 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 694 /* 695 * If we are acting as a multicast router, all 696 * incoming multicast packets are passed to the 697 * kernel-level multicast forwarding function. 698 * The packet is returned (relatively) intact; if 699 * ip6_mforward() returns a non-zero value, the packet 700 * must be discarded, else it may be accepted below. 701 */ 702 if (ip6_mrouter && ip6_mforward && 703 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 704 ip6stat.ip6s_cantforward++; 705 m_freem(m); 706 return; 707 } 708 if (!ours) { 709 m_freem(m); 710 return; 711 } 712 } else if (!ours) { 713 ip6_forward(m, srcrt); 714 return; 715 } 716 717 ip6 = mtod(m, struct ip6_hdr *); 718 719 /* 720 * Malicious party may be able to use IPv4 mapped addr to confuse 721 * tcp/udp stack and bypass security checks (act as if it was from 722 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 723 * 724 * For SIIT end node behavior, you may want to disable the check. 725 * However, you will become vulnerable to attacks using IPv4 mapped 726 * source. 727 */ 728 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 729 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 730 ip6stat.ip6s_badscope++; 731 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 732 goto bad; 733 } 734 735 /* 736 * Tell launch routine the next header 737 */ 738 ip6stat.ip6s_delivered++; 739 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 740 nest = 0; 741 742 while (nxt != IPPROTO_DONE) { 743 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 744 ip6stat.ip6s_toomanyhdr++; 745 goto bad; 746 } 747 748 /* 749 * protection against faulty packet - there should be 750 * more sanity checks in header chain processing. 751 */ 752 if (m->m_pkthdr.len < off) { 753 ip6stat.ip6s_tooshort++; 754 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 755 goto bad; 756 } 757 758 #ifdef IPSEC 759 /* 760 * enforce IPsec policy checking if we are seeing last header. 761 * note that we do not visit this with protocols with pcb layer 762 * code - like udp/tcp/raw ip. 763 */ 764 if (ip6_ipsec_input(m, nxt)) 765 goto bad; 766 #endif /* IPSEC */ 767 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 768 } 769 return; 770 bad: 771 m_freem(m); 772 } 773 774 /* 775 * set/grab in6_ifaddr correspond to IPv6 destination address. 776 * XXX backward compatibility wrapper 777 */ 778 static struct ip6aux * 779 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 780 { 781 struct ip6aux *ip6a; 782 783 ip6a = ip6_addaux(m); 784 if (ip6a) 785 ip6a->ip6a_dstia6 = ia6; 786 return ip6a; /* NULL if failed to set */ 787 } 788 789 struct in6_ifaddr * 790 ip6_getdstifaddr(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 * rtalertp - XXX: should be stored more smart way 806 */ 807 static int 808 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 809 struct mbuf **mp, int *offp) 810 { 811 struct mbuf *m = *mp; 812 int off = *offp, hbhlen; 813 struct ip6_hbh *hbh; 814 u_int8_t *opt; 815 816 /* validation of the length of the header */ 817 #ifndef PULLDOWN_TEST 818 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 819 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 820 hbhlen = (hbh->ip6h_len + 1) << 3; 821 822 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 823 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 824 #else 825 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 826 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 827 if (hbh == NULL) { 828 ip6stat.ip6s_tooshort++; 829 return -1; 830 } 831 hbhlen = (hbh->ip6h_len + 1) << 3; 832 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 833 hbhlen); 834 if (hbh == NULL) { 835 ip6stat.ip6s_tooshort++; 836 return -1; 837 } 838 #endif 839 off += hbhlen; 840 hbhlen -= sizeof(struct ip6_hbh); 841 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 842 843 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 844 hbhlen, rtalertp, plenp) < 0) 845 return (-1); 846 847 *offp = off; 848 *mp = m; 849 return (0); 850 } 851 852 /* 853 * Search header for all Hop-by-hop options and process each option. 854 * This function is separate from ip6_hopopts_input() in order to 855 * handle a case where the sending node itself process its hop-by-hop 856 * options header. In such a case, the function is called from ip6_output(). 857 * 858 * The function assumes that hbh header is located right after the IPv6 header 859 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 860 * opthead + hbhlen is located in continuous memory region. 861 */ 862 int 863 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 864 u_int32_t *rtalertp, u_int32_t *plenp) 865 { 866 struct ip6_hdr *ip6; 867 int optlen = 0; 868 u_int8_t *opt = opthead; 869 u_int16_t rtalert_val; 870 u_int32_t jumboplen; 871 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 872 873 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 874 switch (*opt) { 875 case IP6OPT_PAD1: 876 optlen = 1; 877 break; 878 case IP6OPT_PADN: 879 if (hbhlen < IP6OPT_MINLEN) { 880 ip6stat.ip6s_toosmall++; 881 goto bad; 882 } 883 optlen = *(opt + 1) + 2; 884 break; 885 case IP6OPT_ROUTER_ALERT: 886 /* XXX may need check for alignment */ 887 if (hbhlen < IP6OPT_RTALERT_LEN) { 888 ip6stat.ip6s_toosmall++; 889 goto bad; 890 } 891 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 892 /* XXX stat */ 893 icmp6_error(m, ICMP6_PARAM_PROB, 894 ICMP6_PARAMPROB_HEADER, 895 erroff + opt + 1 - opthead); 896 return (-1); 897 } 898 optlen = IP6OPT_RTALERT_LEN; 899 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 900 *rtalertp = ntohs(rtalert_val); 901 break; 902 case IP6OPT_JUMBO: 903 /* XXX may need check for alignment */ 904 if (hbhlen < IP6OPT_JUMBO_LEN) { 905 ip6stat.ip6s_toosmall++; 906 goto bad; 907 } 908 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 909 /* XXX stat */ 910 icmp6_error(m, ICMP6_PARAM_PROB, 911 ICMP6_PARAMPROB_HEADER, 912 erroff + opt + 1 - opthead); 913 return (-1); 914 } 915 optlen = IP6OPT_JUMBO_LEN; 916 917 /* 918 * IPv6 packets that have non 0 payload length 919 * must not contain a jumbo payload option. 920 */ 921 ip6 = mtod(m, struct ip6_hdr *); 922 if (ip6->ip6_plen) { 923 ip6stat.ip6s_badoptions++; 924 icmp6_error(m, ICMP6_PARAM_PROB, 925 ICMP6_PARAMPROB_HEADER, 926 erroff + opt - opthead); 927 return (-1); 928 } 929 930 /* 931 * We may see jumbolen in unaligned location, so 932 * we'd need to perform bcopy(). 933 */ 934 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 935 jumboplen = (u_int32_t)htonl(jumboplen); 936 937 #if 1 938 /* 939 * if there are multiple jumbo payload options, 940 * *plenp will be non-zero and the packet will be 941 * rejected. 942 * the behavior may need some debate in ipngwg - 943 * multiple options does not make sense, however, 944 * there's no explicit mention in specification. 945 */ 946 if (*plenp != 0) { 947 ip6stat.ip6s_badoptions++; 948 icmp6_error(m, ICMP6_PARAM_PROB, 949 ICMP6_PARAMPROB_HEADER, 950 erroff + opt + 2 - opthead); 951 return (-1); 952 } 953 #endif 954 955 /* 956 * jumbo payload length must be larger than 65535. 957 */ 958 if (jumboplen <= IPV6_MAXPACKET) { 959 ip6stat.ip6s_badoptions++; 960 icmp6_error(m, ICMP6_PARAM_PROB, 961 ICMP6_PARAMPROB_HEADER, 962 erroff + opt + 2 - opthead); 963 return (-1); 964 } 965 *plenp = jumboplen; 966 967 break; 968 default: /* unknown option */ 969 if (hbhlen < IP6OPT_MINLEN) { 970 ip6stat.ip6s_toosmall++; 971 goto bad; 972 } 973 optlen = ip6_unknown_opt(opt, m, 974 erroff + opt - opthead); 975 if (optlen == -1) 976 return (-1); 977 optlen += 2; 978 break; 979 } 980 } 981 982 return (0); 983 984 bad: 985 m_freem(m); 986 return (-1); 987 } 988 989 /* 990 * Unknown option processing. 991 * The third argument `off' is the offset from the IPv6 header to the option, 992 * which is necessary if the IPv6 header the and option header and IPv6 header 993 * is not continuous in order to return an ICMPv6 error. 994 */ 995 int 996 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 997 { 998 struct ip6_hdr *ip6; 999 1000 switch (IP6OPT_TYPE(*optp)) { 1001 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1002 return ((int)*(optp + 1)); 1003 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1004 m_freem(m); 1005 return (-1); 1006 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1007 ip6stat.ip6s_badoptions++; 1008 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1009 return (-1); 1010 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1011 ip6stat.ip6s_badoptions++; 1012 ip6 = mtod(m, struct ip6_hdr *); 1013 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1014 (m->m_flags & (M_BCAST|M_MCAST))) 1015 m_freem(m); 1016 else 1017 icmp6_error(m, ICMP6_PARAM_PROB, 1018 ICMP6_PARAMPROB_OPTION, off); 1019 return (-1); 1020 } 1021 1022 m_freem(m); /* XXX: NOTREACHED */ 1023 return (-1); 1024 } 1025 1026 /* 1027 * Create the "control" list for this pcb. 1028 * These functions will not modify mbuf chain at all. 1029 * 1030 * With KAME mbuf chain restriction: 1031 * The routine will be called from upper layer handlers like tcp6_input(). 1032 * Thus the routine assumes that the caller (tcp6_input) have already 1033 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1034 * very first mbuf on the mbuf chain. 1035 * 1036 * ip6_savecontrol_v4 will handle those options that are possible to be 1037 * set on a v4-mapped socket. 1038 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1039 * options and handle the v6-only ones itself. 1040 */ 1041 struct mbuf ** 1042 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1043 int *v4only) 1044 { 1045 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1046 1047 #ifdef SO_TIMESTAMP 1048 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1049 struct timeval tv; 1050 1051 microtime(&tv); 1052 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1053 SCM_TIMESTAMP, SOL_SOCKET); 1054 if (*mp) 1055 mp = &(*mp)->m_next; 1056 } 1057 #endif 1058 1059 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1060 if (v4only != NULL) 1061 *v4only = 1; 1062 return (mp); 1063 } 1064 1065 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1066 /* RFC 2292 sec. 5 */ 1067 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1068 struct in6_pktinfo pi6; 1069 1070 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1071 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1072 pi6.ipi6_ifindex = 1073 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1074 1075 *mp = sbcreatecontrol((caddr_t) &pi6, 1076 sizeof(struct in6_pktinfo), 1077 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1078 if (*mp) 1079 mp = &(*mp)->m_next; 1080 } 1081 1082 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1083 int hlim = ip6->ip6_hlim & 0xff; 1084 1085 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1086 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1087 IPPROTO_IPV6); 1088 if (*mp) 1089 mp = &(*mp)->m_next; 1090 } 1091 1092 if (v4only != NULL) 1093 *v4only = 0; 1094 return (mp); 1095 } 1096 1097 void 1098 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1099 { 1100 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1101 int v4only = 0; 1102 1103 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1104 if (v4only) 1105 return; 1106 1107 if ((in6p->inp_flags & IN6P_TCLASS) != 0) { 1108 u_int32_t flowinfo; 1109 int tclass; 1110 1111 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1112 flowinfo >>= 20; 1113 1114 tclass = flowinfo & 0xff; 1115 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1116 IPV6_TCLASS, IPPROTO_IPV6); 1117 if (*mp) 1118 mp = &(*mp)->m_next; 1119 } 1120 1121 /* 1122 * IPV6_HOPOPTS socket option. Recall that we required super-user 1123 * privilege for the option (see ip6_ctloutput), but it might be too 1124 * strict, since there might be some hop-by-hop options which can be 1125 * returned to normal user. 1126 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1127 */ 1128 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1129 /* 1130 * Check if a hop-by-hop options header is contatined in the 1131 * received packet, and if so, store the options as ancillary 1132 * data. Note that a hop-by-hop options header must be 1133 * just after the IPv6 header, which is assured through the 1134 * IPv6 input processing. 1135 */ 1136 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1137 struct ip6_hbh *hbh; 1138 int hbhlen = 0; 1139 #ifdef PULLDOWN_TEST 1140 struct mbuf *ext; 1141 #endif 1142 1143 #ifndef PULLDOWN_TEST 1144 hbh = (struct ip6_hbh *)(ip6 + 1); 1145 hbhlen = (hbh->ip6h_len + 1) << 3; 1146 #else 1147 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1148 ip6->ip6_nxt); 1149 if (ext == NULL) { 1150 ip6stat.ip6s_tooshort++; 1151 return; 1152 } 1153 hbh = mtod(ext, struct ip6_hbh *); 1154 hbhlen = (hbh->ip6h_len + 1) << 3; 1155 if (hbhlen != ext->m_len) { 1156 m_freem(ext); 1157 ip6stat.ip6s_tooshort++; 1158 return; 1159 } 1160 #endif 1161 1162 /* 1163 * XXX: We copy the whole header even if a 1164 * jumbo payload option is included, the option which 1165 * is to be removed before returning according to 1166 * RFC2292. 1167 * Note: this constraint is removed in RFC3542 1168 */ 1169 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1170 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1171 IPPROTO_IPV6); 1172 if (*mp) 1173 mp = &(*mp)->m_next; 1174 #ifdef PULLDOWN_TEST 1175 m_freem(ext); 1176 #endif 1177 } 1178 } 1179 1180 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1181 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1182 1183 /* 1184 * Search for destination options headers or routing 1185 * header(s) through the header chain, and stores each 1186 * header as ancillary data. 1187 * Note that the order of the headers remains in 1188 * the chain of ancillary data. 1189 */ 1190 while (1) { /* is explicit loop prevention necessary? */ 1191 struct ip6_ext *ip6e = NULL; 1192 int elen; 1193 #ifdef PULLDOWN_TEST 1194 struct mbuf *ext = NULL; 1195 #endif 1196 1197 /* 1198 * if it is not an extension header, don't try to 1199 * pull it from the chain. 1200 */ 1201 switch (nxt) { 1202 case IPPROTO_DSTOPTS: 1203 case IPPROTO_ROUTING: 1204 case IPPROTO_HOPOPTS: 1205 case IPPROTO_AH: /* is it possible? */ 1206 break; 1207 default: 1208 goto loopend; 1209 } 1210 1211 #ifndef PULLDOWN_TEST 1212 if (off + sizeof(*ip6e) > m->m_len) 1213 goto loopend; 1214 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1215 if (nxt == IPPROTO_AH) 1216 elen = (ip6e->ip6e_len + 2) << 2; 1217 else 1218 elen = (ip6e->ip6e_len + 1) << 3; 1219 if (off + elen > m->m_len) 1220 goto loopend; 1221 #else 1222 ext = ip6_pullexthdr(m, off, nxt); 1223 if (ext == NULL) { 1224 ip6stat.ip6s_tooshort++; 1225 return; 1226 } 1227 ip6e = mtod(ext, struct ip6_ext *); 1228 if (nxt == IPPROTO_AH) 1229 elen = (ip6e->ip6e_len + 2) << 2; 1230 else 1231 elen = (ip6e->ip6e_len + 1) << 3; 1232 if (elen != ext->m_len) { 1233 m_freem(ext); 1234 ip6stat.ip6s_tooshort++; 1235 return; 1236 } 1237 #endif 1238 1239 switch (nxt) { 1240 case IPPROTO_DSTOPTS: 1241 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1242 break; 1243 1244 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1245 IS2292(in6p, 1246 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1247 IPPROTO_IPV6); 1248 if (*mp) 1249 mp = &(*mp)->m_next; 1250 break; 1251 case IPPROTO_ROUTING: 1252 if (!in6p->inp_flags & IN6P_RTHDR) 1253 break; 1254 1255 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1256 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1257 IPPROTO_IPV6); 1258 if (*mp) 1259 mp = &(*mp)->m_next; 1260 break; 1261 case IPPROTO_HOPOPTS: 1262 case IPPROTO_AH: /* is it possible? */ 1263 break; 1264 1265 default: 1266 /* 1267 * other cases have been filtered in the above. 1268 * none will visit this case. here we supply 1269 * the code just in case (nxt overwritten or 1270 * other cases). 1271 */ 1272 #ifdef PULLDOWN_TEST 1273 m_freem(ext); 1274 #endif 1275 goto loopend; 1276 1277 } 1278 1279 /* proceed with the next header. */ 1280 off += elen; 1281 nxt = ip6e->ip6e_nxt; 1282 ip6e = NULL; 1283 #ifdef PULLDOWN_TEST 1284 m_freem(ext); 1285 ext = NULL; 1286 #endif 1287 } 1288 loopend: 1289 ; 1290 } 1291 } 1292 #undef IS2292 1293 1294 void 1295 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1296 { 1297 struct socket *so; 1298 struct mbuf *m_mtu; 1299 struct ip6_mtuinfo mtuctl; 1300 1301 so = in6p->inp_socket; 1302 1303 if (mtu == NULL) 1304 return; 1305 1306 #ifdef DIAGNOSTIC 1307 if (so == NULL) /* I believe this is impossible */ 1308 panic("ip6_notify_pmtu: socket is NULL"); 1309 #endif 1310 1311 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1312 mtuctl.ip6m_mtu = *mtu; 1313 mtuctl.ip6m_addr = *dst; 1314 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1315 return; 1316 1317 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1318 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1319 return; 1320 1321 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1322 == 0) { 1323 m_freem(m_mtu); 1324 /* XXX: should count statistics */ 1325 } else 1326 sorwakeup(so); 1327 1328 return; 1329 } 1330 1331 #ifdef PULLDOWN_TEST 1332 /* 1333 * pull single extension header from mbuf chain. returns single mbuf that 1334 * contains the result, or NULL on error. 1335 */ 1336 static struct mbuf * 1337 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1338 { 1339 struct ip6_ext ip6e; 1340 size_t elen; 1341 struct mbuf *n; 1342 1343 #ifdef DIAGNOSTIC 1344 switch (nxt) { 1345 case IPPROTO_DSTOPTS: 1346 case IPPROTO_ROUTING: 1347 case IPPROTO_HOPOPTS: 1348 case IPPROTO_AH: /* is it possible? */ 1349 break; 1350 default: 1351 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1352 } 1353 #endif 1354 1355 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1356 if (nxt == IPPROTO_AH) 1357 elen = (ip6e.ip6e_len + 2) << 2; 1358 else 1359 elen = (ip6e.ip6e_len + 1) << 3; 1360 1361 MGET(n, M_DONTWAIT, MT_DATA); 1362 if (n && elen >= MLEN) { 1363 MCLGET(n, M_DONTWAIT); 1364 if ((n->m_flags & M_EXT) == 0) { 1365 m_free(n); 1366 n = NULL; 1367 } 1368 } 1369 if (!n) 1370 return NULL; 1371 1372 n->m_len = 0; 1373 if (elen >= M_TRAILINGSPACE(n)) { 1374 m_free(n); 1375 return NULL; 1376 } 1377 1378 m_copydata(m, off, elen, mtod(n, caddr_t)); 1379 n->m_len = elen; 1380 return n; 1381 } 1382 #endif 1383 1384 /* 1385 * Get pointer to the previous header followed by the header 1386 * currently processed. 1387 * XXX: This function supposes that 1388 * M includes all headers, 1389 * the next header field and the header length field of each header 1390 * are valid, and 1391 * the sum of each header length equals to OFF. 1392 * Because of these assumptions, this function must be called very 1393 * carefully. Moreover, it will not be used in the near future when 1394 * we develop `neater' mechanism to process extension headers. 1395 */ 1396 char * 1397 ip6_get_prevhdr(struct mbuf *m, int off) 1398 { 1399 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1400 1401 if (off == sizeof(struct ip6_hdr)) 1402 return (&ip6->ip6_nxt); 1403 else { 1404 int len, nxt; 1405 struct ip6_ext *ip6e = NULL; 1406 1407 nxt = ip6->ip6_nxt; 1408 len = sizeof(struct ip6_hdr); 1409 while (len < off) { 1410 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1411 1412 switch (nxt) { 1413 case IPPROTO_FRAGMENT: 1414 len += sizeof(struct ip6_frag); 1415 break; 1416 case IPPROTO_AH: 1417 len += (ip6e->ip6e_len + 2) << 2; 1418 break; 1419 default: 1420 len += (ip6e->ip6e_len + 1) << 3; 1421 break; 1422 } 1423 nxt = ip6e->ip6e_nxt; 1424 } 1425 if (ip6e) 1426 return (&ip6e->ip6e_nxt); 1427 else 1428 return NULL; 1429 } 1430 } 1431 1432 /* 1433 * get next header offset. m will be retained. 1434 */ 1435 int 1436 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1437 { 1438 struct ip6_hdr ip6; 1439 struct ip6_ext ip6e; 1440 struct ip6_frag fh; 1441 1442 /* just in case */ 1443 if (m == NULL) 1444 panic("ip6_nexthdr: m == NULL"); 1445 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1446 return -1; 1447 1448 switch (proto) { 1449 case IPPROTO_IPV6: 1450 if (m->m_pkthdr.len < off + sizeof(ip6)) 1451 return -1; 1452 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1453 if (nxtp) 1454 *nxtp = ip6.ip6_nxt; 1455 off += sizeof(ip6); 1456 return off; 1457 1458 case IPPROTO_FRAGMENT: 1459 /* 1460 * terminate parsing if it is not the first fragment, 1461 * it does not make sense to parse through it. 1462 */ 1463 if (m->m_pkthdr.len < off + sizeof(fh)) 1464 return -1; 1465 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1466 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1467 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1468 return -1; 1469 if (nxtp) 1470 *nxtp = fh.ip6f_nxt; 1471 off += sizeof(struct ip6_frag); 1472 return off; 1473 1474 case IPPROTO_AH: 1475 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1476 return -1; 1477 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1478 if (nxtp) 1479 *nxtp = ip6e.ip6e_nxt; 1480 off += (ip6e.ip6e_len + 2) << 2; 1481 return off; 1482 1483 case IPPROTO_HOPOPTS: 1484 case IPPROTO_ROUTING: 1485 case IPPROTO_DSTOPTS: 1486 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1487 return -1; 1488 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1489 if (nxtp) 1490 *nxtp = ip6e.ip6e_nxt; 1491 off += (ip6e.ip6e_len + 1) << 3; 1492 return off; 1493 1494 case IPPROTO_NONE: 1495 case IPPROTO_ESP: 1496 case IPPROTO_IPCOMP: 1497 /* give up */ 1498 return -1; 1499 1500 default: 1501 return -1; 1502 } 1503 1504 return -1; 1505 } 1506 1507 /* 1508 * get offset for the last header in the chain. m will be kept untainted. 1509 */ 1510 int 1511 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1512 { 1513 int newoff; 1514 int nxt; 1515 1516 if (!nxtp) { 1517 nxt = -1; 1518 nxtp = &nxt; 1519 } 1520 while (1) { 1521 newoff = ip6_nexthdr(m, off, proto, nxtp); 1522 if (newoff < 0) 1523 return off; 1524 else if (newoff < off) 1525 return -1; /* invalid */ 1526 else if (newoff == off) 1527 return newoff; 1528 1529 off = newoff; 1530 proto = *nxtp; 1531 } 1532 } 1533 1534 struct ip6aux * 1535 ip6_addaux(struct mbuf *m) 1536 { 1537 struct m_tag *mtag; 1538 1539 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1540 if (!mtag) { 1541 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1542 M_NOWAIT); 1543 if (mtag) { 1544 m_tag_prepend(m, mtag); 1545 bzero(mtag + 1, sizeof(struct ip6aux)); 1546 } 1547 } 1548 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1549 } 1550 1551 struct ip6aux * 1552 ip6_findaux(struct mbuf *m) 1553 { 1554 struct m_tag *mtag; 1555 1556 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1557 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1558 } 1559 1560 void 1561 ip6_delaux(struct mbuf *m) 1562 { 1563 struct m_tag *mtag; 1564 1565 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1566 if (mtag) 1567 m_tag_delete(m, mtag); 1568 } 1569 1570 /* 1571 * System control for IP6 1572 */ 1573 1574 u_char inet6ctlerrmap[PRC_NCMDS] = { 1575 0, 0, 0, 0, 1576 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1577 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1578 EMSGSIZE, EHOSTUNREACH, 0, 0, 1579 0, 0, 0, 0, 1580 ENOPROTOOPT 1581 };
Cache object: 2da6a672ce40cecfe66b70246f1e79aa
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