1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1988, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 #include "opt_ipsec.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/proc.h> 75 #include <sys/domain.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/errno.h> 80 #include <sys/time.h> 81 #include <sys/kernel.h> 82 #include <sys/syslog.h> 83 #include <sys/vimage.h> 84 85 #include <net/if.h> 86 #include <net/if_types.h> 87 #include <net/if_dl.h> 88 #include <net/route.h> 89 #include <net/netisr.h> 90 #include <net/pfil.h> 91 92 #include <netinet/in.h> 93 #include <netinet/in_systm.h> 94 #ifdef INET 95 #include <netinet/ip.h> 96 #include <netinet/ip_icmp.h> 97 #endif /* INET */ 98 #include <netinet/ip6.h> 99 #include <netinet6/in6_var.h> 100 #include <netinet6/ip6_var.h> 101 #include <netinet/in_pcb.h> 102 #include <netinet/icmp6.h> 103 #include <netinet6/scope6_var.h> 104 #include <netinet6/in6_ifattach.h> 105 #include <netinet6/nd6.h> 106 107 #ifdef IPSEC 108 #include <netipsec/ipsec.h> 109 #include <netinet6/ip6_ipsec.h> 110 #include <netipsec/ipsec6.h> 111 #endif /* IPSEC */ 112 113 #include <netinet6/ip6protosw.h> 114 115 extern struct domain inet6domain; 116 117 u_char ip6_protox[IPPROTO_MAX]; 118 static struct ifqueue ip6intrq; 119 static int ip6qmaxlen = IFQ_MAXLEN; 120 struct in6_ifaddr *in6_ifaddr; 121 122 extern struct callout in6_tmpaddrtimer_ch; 123 124 int ip6_forward_srcrt; /* XXX */ 125 int ip6_sourcecheck; /* XXX */ 126 int ip6_sourcecheck_interval; /* XXX */ 127 128 int ip6_ours_check_algorithm; 129 130 struct pfil_head inet6_pfil_hook; 131 132 struct ip6stat ip6stat; 133 134 static void ip6_init2(void *); 135 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 136 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 137 #ifdef PULLDOWN_TEST 138 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 139 #endif 140 141 /* 142 * IP6 initialization: fill in IP6 protocol switch table. 143 * All protocols not implemented in kernel go to raw IP6 protocol handler. 144 */ 145 void 146 ip6_init(void) 147 { 148 struct ip6protosw *pr; 149 int i; 150 151 #ifdef DIAGNOSTIC 152 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 153 panic("sizeof(protosw) != sizeof(ip6protosw)"); 154 #endif 155 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 156 if (pr == 0) 157 panic("ip6_init"); 158 159 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 160 for (i = 0; i < IPPROTO_MAX; i++) 161 ip6_protox[i] = pr - inet6sw; 162 /* 163 * Cycle through IP protocols and put them into the appropriate place 164 * in ip6_protox[]. 165 */ 166 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 167 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 168 if (pr->pr_domain->dom_family == PF_INET6 && 169 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 170 /* Be careful to only index valid IP protocols. */ 171 if (pr->pr_protocol < IPPROTO_MAX) 172 ip6_protox[pr->pr_protocol] = pr - inet6sw; 173 } 174 175 /* Initialize packet filter hooks. */ 176 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 177 inet6_pfil_hook.ph_af = AF_INET6; 178 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 179 printf("%s: WARNING: unable to register pfil hook, " 180 "error %d\n", __func__, i); 181 182 ip6intrq.ifq_maxlen = V_ip6qmaxlen; 183 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 184 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 185 scope6_init(); 186 addrsel_policy_init(); 187 nd6_init(); 188 frag6_init(); 189 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 190 } 191 192 static void 193 ip6_init2(void *dummy) 194 { 195 196 /* nd6_timer_init */ 197 callout_init(&V_nd6_timer_ch, 0); 198 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, NULL); 199 200 /* timer for regeneranation of temporary addresses randomize ID */ 201 callout_init(&V_in6_tmpaddrtimer_ch, 0); 202 callout_reset(&V_in6_tmpaddrtimer_ch, 203 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor - 204 V_ip6_temp_regen_advance) * hz, 205 in6_tmpaddrtimer, NULL); 206 } 207 208 /* cheat */ 209 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 210 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 211 212 extern struct route_in6 ip6_forward_rt; 213 214 void 215 ip6_input(struct mbuf *m) 216 { 217 struct ip6_hdr *ip6; 218 int off = sizeof(struct ip6_hdr), nest; 219 u_int32_t plen; 220 u_int32_t rtalert = ~0; 221 int nxt, ours = 0; 222 struct ifnet *deliverifp = NULL; 223 struct in6_addr odst; 224 int srcrt = 0; 225 226 #ifdef IPSEC 227 /* 228 * should the inner packet be considered authentic? 229 * see comment in ah4_input(). 230 * NB: m cannot be NULL when passed to the input routine 231 */ 232 233 m->m_flags &= ~M_AUTHIPHDR; 234 m->m_flags &= ~M_AUTHIPDGM; 235 236 #endif /* IPSEC */ 237 238 /* 239 * make sure we don't have onion peering information into m_tag. 240 */ 241 ip6_delaux(m); 242 243 /* 244 * mbuf statistics 245 */ 246 if (m->m_flags & M_EXT) { 247 if (m->m_next) 248 V_ip6stat.ip6s_mext2m++; 249 else 250 V_ip6stat.ip6s_mext1++; 251 } else { 252 #define M2MMAX (sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0])) 253 if (m->m_next) { 254 if (m->m_flags & M_LOOP) { 255 V_ip6stat.ip6s_m2m[V_loif[0].if_index]++; /* XXX */ 256 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 257 V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 258 else 259 V_ip6stat.ip6s_m2m[0]++; 260 } else 261 V_ip6stat.ip6s_m1++; 262 #undef M2MMAX 263 } 264 265 /* drop the packet if IPv6 operation is disabled on the IF */ 266 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 267 m_freem(m); 268 return; 269 } 270 271 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 272 V_ip6stat.ip6s_total++; 273 274 #ifndef PULLDOWN_TEST 275 /* 276 * L2 bridge code and some other code can return mbuf chain 277 * that does not conform to KAME requirement. too bad. 278 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 279 */ 280 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 281 struct mbuf *n; 282 283 MGETHDR(n, M_DONTWAIT, MT_HEADER); 284 if (n) 285 M_MOVE_PKTHDR(n, m); 286 if (n && n->m_pkthdr.len > MHLEN) { 287 MCLGET(n, M_DONTWAIT); 288 if ((n->m_flags & M_EXT) == 0) { 289 m_freem(n); 290 n = NULL; 291 } 292 } 293 if (n == NULL) { 294 m_freem(m); 295 return; /* ENOBUFS */ 296 } 297 298 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 299 n->m_len = n->m_pkthdr.len; 300 m_freem(m); 301 m = n; 302 } 303 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 304 #endif 305 306 if (m->m_len < sizeof(struct ip6_hdr)) { 307 struct ifnet *inifp; 308 inifp = m->m_pkthdr.rcvif; 309 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 310 V_ip6stat.ip6s_toosmall++; 311 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 312 return; 313 } 314 } 315 316 ip6 = mtod(m, struct ip6_hdr *); 317 318 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 319 V_ip6stat.ip6s_badvers++; 320 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 321 goto bad; 322 } 323 324 V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 325 326 /* 327 * Check against address spoofing/corruption. 328 */ 329 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 330 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 331 /* 332 * XXX: "badscope" is not very suitable for a multicast source. 333 */ 334 V_ip6stat.ip6s_badscope++; 335 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 336 goto bad; 337 } 338 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 339 !(m->m_flags & M_LOOP)) { 340 /* 341 * In this case, the packet should come from the loopback 342 * interface. However, we cannot just check the if_flags, 343 * because ip6_mloopback() passes the "actual" interface 344 * as the outgoing/incoming interface. 345 */ 346 V_ip6stat.ip6s_badscope++; 347 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 348 goto bad; 349 } 350 351 #ifdef ALTQ 352 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 353 /* packet is dropped by traffic conditioner */ 354 return; 355 } 356 #endif 357 /* 358 * The following check is not documented in specs. A malicious 359 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 360 * and bypass security checks (act as if it was from 127.0.0.1 by using 361 * IPv6 src ::ffff:127.0.0.1). Be cautious. 362 * 363 * This check chokes if we are in an SIIT cloud. As none of BSDs 364 * support IPv4-less kernel compilation, we cannot support SIIT 365 * environment at all. So, it makes more sense for us to reject any 366 * malicious packets for non-SIIT environment, than try to do a 367 * partial support for SIIT environment. 368 */ 369 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 370 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 371 V_ip6stat.ip6s_badscope++; 372 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 373 goto bad; 374 } 375 #if 0 376 /* 377 * Reject packets with IPv4 compatible addresses (auto tunnel). 378 * 379 * The code forbids auto tunnel relay case in RFC1933 (the check is 380 * stronger than RFC1933). We may want to re-enable it if mech-xx 381 * is revised to forbid relaying case. 382 */ 383 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 384 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 385 V_ip6stat.ip6s_badscope++; 386 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 387 goto bad; 388 } 389 #endif 390 391 /* 392 * Run through list of hooks for input packets. 393 * 394 * NB: Beware of the destination address changing 395 * (e.g. by NAT rewriting). When this happens, 396 * tell ip6_forward to do the right thing. 397 */ 398 odst = ip6->ip6_dst; 399 400 /* Jump over all PFIL processing if hooks are not active. */ 401 if (!PFIL_HOOKED(&inet6_pfil_hook)) 402 goto passin; 403 404 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 405 return; 406 if (m == NULL) /* consumed by filter */ 407 return; 408 ip6 = mtod(m, struct ip6_hdr *); 409 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 410 411 passin: 412 /* 413 * Disambiguate address scope zones (if there is ambiguity). 414 * We first make sure that the original source or destination address 415 * is not in our internal form for scoped addresses. Such addresses 416 * are not necessarily invalid spec-wise, but we cannot accept them due 417 * to the usage conflict. 418 * in6_setscope() then also checks and rejects the cases where src or 419 * dst are the loopback address and the receiving interface 420 * is not loopback. 421 */ 422 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 423 V_ip6stat.ip6s_badscope++; /* XXX */ 424 goto bad; 425 } 426 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 427 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 428 V_ip6stat.ip6s_badscope++; 429 goto bad; 430 } 431 432 /* 433 * Multicast check 434 */ 435 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 436 struct in6_multi *in6m = 0; 437 438 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 439 /* 440 * See if we belong to the destination multicast group on the 441 * arrival interface. 442 */ 443 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 444 if (in6m) 445 ours = 1; 446 else if (!ip6_mrouter) { 447 V_ip6stat.ip6s_notmember++; 448 V_ip6stat.ip6s_cantforward++; 449 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 450 goto bad; 451 } 452 deliverifp = m->m_pkthdr.rcvif; 453 goto hbhcheck; 454 } 455 456 /* 457 * Unicast check 458 */ 459 if (V_ip6_forward_rt.ro_rt != NULL && 460 (V_ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 461 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 462 &((struct sockaddr_in6 *)(&V_ip6_forward_rt.ro_dst))->sin6_addr)) 463 V_ip6stat.ip6s_forward_cachehit++; 464 else { 465 struct sockaddr_in6 *dst6; 466 467 if (V_ip6_forward_rt.ro_rt) { 468 /* route is down or destination is different */ 469 V_ip6stat.ip6s_forward_cachemiss++; 470 RTFREE(V_ip6_forward_rt.ro_rt); 471 V_ip6_forward_rt.ro_rt = 0; 472 } 473 474 bzero(&V_ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 475 dst6 = (struct sockaddr_in6 *)&V_ip6_forward_rt.ro_dst; 476 dst6->sin6_len = sizeof(struct sockaddr_in6); 477 dst6->sin6_family = AF_INET6; 478 dst6->sin6_addr = ip6->ip6_dst; 479 480 rtalloc((struct route *)&V_ip6_forward_rt); 481 } 482 483 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 484 485 /* 486 * Accept the packet if the forwarding interface to the destination 487 * according to the routing table is the loopback interface, 488 * unless the associated route has a gateway. 489 * Note that this approach causes to accept a packet if there is a 490 * route to the loopback interface for the destination of the packet. 491 * But we think it's even useful in some situations, e.g. when using 492 * a special daemon which wants to intercept the packet. 493 * 494 * XXX: some OSes automatically make a cloned route for the destination 495 * of an outgoing packet. If the outgoing interface of the packet 496 * is a loopback one, the kernel would consider the packet to be 497 * accepted, even if we have no such address assinged on the interface. 498 * We check the cloned flag of the route entry to reject such cases, 499 * assuming that route entries for our own addresses are not made by 500 * cloning (it should be true because in6_addloop explicitly installs 501 * the host route). However, we might have to do an explicit check 502 * while it would be less efficient. Or, should we rather install a 503 * reject route for such a case? 504 */ 505 if (V_ip6_forward_rt.ro_rt && 506 (V_ip6_forward_rt.ro_rt->rt_flags & 507 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 508 #ifdef RTF_WASCLONED 509 !(V_ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 510 #endif 511 #ifdef RTF_CLONED 512 !(V_ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 513 #endif 514 #if 0 515 /* 516 * The check below is redundant since the comparison of 517 * the destination and the key of the rtentry has 518 * already done through looking up the routing table. 519 */ 520 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 521 &rt6_key(V_ip6_forward_rt.ro_rt)->sin6_addr) 522 #endif 523 V_ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 524 struct in6_ifaddr *ia6 = 525 (struct in6_ifaddr *)V_ip6_forward_rt.ro_rt->rt_ifa; 526 527 /* 528 * record address information into m_tag. 529 */ 530 (void)ip6_setdstifaddr(m, ia6); 531 532 /* 533 * packets to a tentative, duplicated, or somehow invalid 534 * address must not be accepted. 535 */ 536 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 537 /* this address is ready */ 538 ours = 1; 539 deliverifp = ia6->ia_ifp; /* correct? */ 540 /* Count the packet in the ip address stats */ 541 ia6->ia_ifa.if_ipackets++; 542 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 543 goto hbhcheck; 544 } else { 545 char ip6bufs[INET6_ADDRSTRLEN]; 546 char ip6bufd[INET6_ADDRSTRLEN]; 547 /* address is not ready, so discard the packet. */ 548 nd6log((LOG_INFO, 549 "ip6_input: packet to an unready address %s->%s\n", 550 ip6_sprintf(ip6bufs, &ip6->ip6_src), 551 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 552 553 goto bad; 554 } 555 } 556 557 /* 558 * FAITH (Firewall Aided Internet Translator) 559 */ 560 if (V_ip6_keepfaith) { 561 if (V_ip6_forward_rt.ro_rt && V_ip6_forward_rt.ro_rt->rt_ifp 562 && V_ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 563 /* XXX do we need more sanity checks? */ 564 ours = 1; 565 deliverifp = V_ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 566 goto hbhcheck; 567 } 568 } 569 570 /* 571 * Now there is no reason to process the packet if it's not our own 572 * and we're not a router. 573 */ 574 if (!V_ip6_forwarding) { 575 V_ip6stat.ip6s_cantforward++; 576 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 577 goto bad; 578 } 579 580 hbhcheck: 581 /* 582 * record address information into m_tag, if we don't have one yet. 583 * note that we are unable to record it, if the address is not listed 584 * as our interface address (e.g. multicast addresses, addresses 585 * within FAITH prefixes and such). 586 */ 587 if (deliverifp && !ip6_getdstifaddr(m)) { 588 struct in6_ifaddr *ia6; 589 590 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 591 if (ia6) { 592 if (!ip6_setdstifaddr(m, ia6)) { 593 /* 594 * XXX maybe we should drop the packet here, 595 * as we could not provide enough information 596 * to the upper layers. 597 */ 598 } 599 } 600 } 601 602 /* 603 * Process Hop-by-Hop options header if it's contained. 604 * m may be modified in ip6_hopopts_input(). 605 * If a JumboPayload option is included, plen will also be modified. 606 */ 607 plen = (u_int32_t)ntohs(ip6->ip6_plen); 608 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 609 struct ip6_hbh *hbh; 610 611 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 612 #if 0 /*touches NULL pointer*/ 613 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 614 #endif 615 return; /* m have already been freed */ 616 } 617 618 /* adjust pointer */ 619 ip6 = mtod(m, struct ip6_hdr *); 620 621 /* 622 * if the payload length field is 0 and the next header field 623 * indicates Hop-by-Hop Options header, then a Jumbo Payload 624 * option MUST be included. 625 */ 626 if (ip6->ip6_plen == 0 && plen == 0) { 627 /* 628 * Note that if a valid jumbo payload option is 629 * contained, ip6_hopopts_input() must set a valid 630 * (non-zero) payload length to the variable plen. 631 */ 632 V_ip6stat.ip6s_badoptions++; 633 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 634 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 635 icmp6_error(m, ICMP6_PARAM_PROB, 636 ICMP6_PARAMPROB_HEADER, 637 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 638 return; 639 } 640 #ifndef PULLDOWN_TEST 641 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 642 hbh = (struct ip6_hbh *)(ip6 + 1); 643 #else 644 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 645 sizeof(struct ip6_hbh)); 646 if (hbh == NULL) { 647 V_ip6stat.ip6s_tooshort++; 648 return; 649 } 650 #endif 651 nxt = hbh->ip6h_nxt; 652 653 /* 654 * If we are acting as a router and the packet contains a 655 * router alert option, see if we know the option value. 656 * Currently, we only support the option value for MLD, in which 657 * case we should pass the packet to the multicast routing 658 * daemon. 659 */ 660 if (rtalert != ~0 && V_ip6_forwarding) { 661 switch (rtalert) { 662 case IP6OPT_RTALERT_MLD: 663 ours = 1; 664 break; 665 default: 666 /* 667 * RFC2711 requires unrecognized values must be 668 * silently ignored. 669 */ 670 break; 671 } 672 } 673 } else 674 nxt = ip6->ip6_nxt; 675 676 /* 677 * Check that the amount of data in the buffers 678 * is as at least much as the IPv6 header would have us expect. 679 * Trim mbufs if longer than we expect. 680 * Drop packet if shorter than we expect. 681 */ 682 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 683 V_ip6stat.ip6s_tooshort++; 684 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 685 goto bad; 686 } 687 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 688 if (m->m_len == m->m_pkthdr.len) { 689 m->m_len = sizeof(struct ip6_hdr) + plen; 690 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 691 } else 692 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 693 } 694 695 /* 696 * Forward if desirable. 697 */ 698 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 699 /* 700 * If we are acting as a multicast router, all 701 * incoming multicast packets are passed to the 702 * kernel-level multicast forwarding function. 703 * The packet is returned (relatively) intact; if 704 * ip6_mforward() returns a non-zero value, the packet 705 * must be discarded, else it may be accepted below. 706 */ 707 if (ip6_mrouter && ip6_mforward && 708 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 709 V_ip6stat.ip6s_cantforward++; 710 m_freem(m); 711 return; 712 } 713 if (!ours) { 714 m_freem(m); 715 return; 716 } 717 } else if (!ours) { 718 ip6_forward(m, srcrt); 719 return; 720 } 721 722 ip6 = mtod(m, struct ip6_hdr *); 723 724 /* 725 * Malicious party may be able to use IPv4 mapped addr to confuse 726 * tcp/udp stack and bypass security checks (act as if it was from 727 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 728 * 729 * For SIIT end node behavior, you may want to disable the check. 730 * However, you will become vulnerable to attacks using IPv4 mapped 731 * source. 732 */ 733 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 734 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 735 V_ip6stat.ip6s_badscope++; 736 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 737 goto bad; 738 } 739 740 /* 741 * Tell launch routine the next header 742 */ 743 V_ip6stat.ip6s_delivered++; 744 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 745 nest = 0; 746 747 while (nxt != IPPROTO_DONE) { 748 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 749 V_ip6stat.ip6s_toomanyhdr++; 750 goto bad; 751 } 752 753 /* 754 * protection against faulty packet - there should be 755 * more sanity checks in header chain processing. 756 */ 757 if (m->m_pkthdr.len < off) { 758 V_ip6stat.ip6s_tooshort++; 759 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 760 goto bad; 761 } 762 763 #ifdef IPSEC 764 /* 765 * enforce IPsec policy checking if we are seeing last header. 766 * note that we do not visit this with protocols with pcb layer 767 * code - like udp/tcp/raw ip. 768 */ 769 if (ip6_ipsec_input(m, nxt)) 770 goto bad; 771 #endif /* IPSEC */ 772 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 773 } 774 return; 775 bad: 776 m_freem(m); 777 } 778 779 /* 780 * set/grab in6_ifaddr correspond to IPv6 destination address. 781 * XXX backward compatibility wrapper 782 */ 783 static struct ip6aux * 784 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 785 { 786 struct ip6aux *ip6a; 787 788 ip6a = ip6_addaux(m); 789 if (ip6a) 790 ip6a->ip6a_dstia6 = ia6; 791 return ip6a; /* NULL if failed to set */ 792 } 793 794 struct in6_ifaddr * 795 ip6_getdstifaddr(struct mbuf *m) 796 { 797 struct ip6aux *ip6a; 798 799 ip6a = ip6_findaux(m); 800 if (ip6a) 801 return ip6a->ip6a_dstia6; 802 else 803 return NULL; 804 } 805 806 /* 807 * Hop-by-Hop options header processing. If a valid jumbo payload option is 808 * included, the real payload length will be stored in plenp. 809 * 810 * rtalertp - XXX: should be stored more smart way 811 */ 812 static int 813 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 814 struct mbuf **mp, int *offp) 815 { 816 struct mbuf *m = *mp; 817 int off = *offp, hbhlen; 818 struct ip6_hbh *hbh; 819 u_int8_t *opt; 820 821 /* validation of the length of the header */ 822 #ifndef PULLDOWN_TEST 823 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 824 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 825 hbhlen = (hbh->ip6h_len + 1) << 3; 826 827 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 828 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 829 #else 830 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 831 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 832 if (hbh == NULL) { 833 V_ip6stat.ip6s_tooshort++; 834 return -1; 835 } 836 hbhlen = (hbh->ip6h_len + 1) << 3; 837 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 838 hbhlen); 839 if (hbh == NULL) { 840 V_ip6stat.ip6s_tooshort++; 841 return -1; 842 } 843 #endif 844 off += hbhlen; 845 hbhlen -= sizeof(struct ip6_hbh); 846 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 847 848 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 849 hbhlen, rtalertp, plenp) < 0) 850 return (-1); 851 852 *offp = off; 853 *mp = m; 854 return (0); 855 } 856 857 /* 858 * Search header for all Hop-by-hop options and process each option. 859 * This function is separate from ip6_hopopts_input() in order to 860 * handle a case where the sending node itself process its hop-by-hop 861 * options header. In such a case, the function is called from ip6_output(). 862 * 863 * The function assumes that hbh header is located right after the IPv6 header 864 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 865 * opthead + hbhlen is located in continuous memory region. 866 */ 867 int 868 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 869 u_int32_t *rtalertp, 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 V_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 V_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 V_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 V_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 V_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 V_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 V_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(u_int8_t *optp, struct mbuf *m, int off) 1002 { 1003 struct ip6_hdr *ip6; 1004 1005 switch (IP6OPT_TYPE(*optp)) { 1006 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1007 return ((int)*(optp + 1)); 1008 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1009 m_freem(m); 1010 return (-1); 1011 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1012 V_ip6stat.ip6s_badoptions++; 1013 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1014 return (-1); 1015 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1016 V_ip6stat.ip6s_badoptions++; 1017 ip6 = mtod(m, struct ip6_hdr *); 1018 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1019 (m->m_flags & (M_BCAST|M_MCAST))) 1020 m_freem(m); 1021 else 1022 icmp6_error(m, ICMP6_PARAM_PROB, 1023 ICMP6_PARAMPROB_OPTION, off); 1024 return (-1); 1025 } 1026 1027 m_freem(m); /* XXX: NOTREACHED */ 1028 return (-1); 1029 } 1030 1031 /* 1032 * Create the "control" list for this pcb. 1033 * These functions will not modify mbuf chain at all. 1034 * 1035 * With KAME mbuf chain restriction: 1036 * The routine will be called from upper layer handlers like tcp6_input(). 1037 * Thus the routine assumes that the caller (tcp6_input) have already 1038 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1039 * very first mbuf on the mbuf chain. 1040 * 1041 * ip6_savecontrol_v4 will handle those options that are possible to be 1042 * set on a v4-mapped socket. 1043 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1044 * options and handle the v6-only ones itself. 1045 */ 1046 struct mbuf ** 1047 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1048 int *v4only) 1049 { 1050 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1051 1052 #ifdef SO_TIMESTAMP 1053 if ((inp->inp_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 if (v4only != NULL) 1066 *v4only = 1; 1067 return (mp); 1068 } 1069 1070 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1071 /* RFC 2292 sec. 5 */ 1072 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1073 struct in6_pktinfo pi6; 1074 1075 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1076 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1077 pi6.ipi6_ifindex = 1078 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1079 1080 *mp = sbcreatecontrol((caddr_t) &pi6, 1081 sizeof(struct in6_pktinfo), 1082 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1083 if (*mp) 1084 mp = &(*mp)->m_next; 1085 } 1086 1087 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1088 int hlim = ip6->ip6_hlim & 0xff; 1089 1090 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1091 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1092 IPPROTO_IPV6); 1093 if (*mp) 1094 mp = &(*mp)->m_next; 1095 } 1096 1097 if (v4only != NULL) 1098 *v4only = 0; 1099 return (mp); 1100 } 1101 1102 void 1103 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1104 { 1105 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1106 int v4only = 0; 1107 1108 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1109 if (v4only) 1110 return; 1111 1112 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1113 u_int32_t flowinfo; 1114 int tclass; 1115 1116 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1117 flowinfo >>= 20; 1118 1119 tclass = flowinfo & 0xff; 1120 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1121 IPV6_TCLASS, IPPROTO_IPV6); 1122 if (*mp) 1123 mp = &(*mp)->m_next; 1124 } 1125 1126 /* 1127 * IPV6_HOPOPTS socket option. Recall that we required super-user 1128 * privilege for the option (see ip6_ctloutput), but it might be too 1129 * strict, since there might be some hop-by-hop options which can be 1130 * returned to normal user. 1131 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1132 */ 1133 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1134 /* 1135 * Check if a hop-by-hop options header is contatined in the 1136 * received packet, and if so, store the options as ancillary 1137 * data. Note that a hop-by-hop options header must be 1138 * just after the IPv6 header, which is assured through the 1139 * IPv6 input processing. 1140 */ 1141 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1142 struct ip6_hbh *hbh; 1143 int hbhlen = 0; 1144 #ifdef PULLDOWN_TEST 1145 struct mbuf *ext; 1146 #endif 1147 1148 #ifndef PULLDOWN_TEST 1149 hbh = (struct ip6_hbh *)(ip6 + 1); 1150 hbhlen = (hbh->ip6h_len + 1) << 3; 1151 #else 1152 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1153 ip6->ip6_nxt); 1154 if (ext == NULL) { 1155 V_ip6stat.ip6s_tooshort++; 1156 return; 1157 } 1158 hbh = mtod(ext, struct ip6_hbh *); 1159 hbhlen = (hbh->ip6h_len + 1) << 3; 1160 if (hbhlen != ext->m_len) { 1161 m_freem(ext); 1162 V_ip6stat.ip6s_tooshort++; 1163 return; 1164 } 1165 #endif 1166 1167 /* 1168 * XXX: We copy the whole header even if a 1169 * jumbo payload option is included, the option which 1170 * is to be removed before returning according to 1171 * RFC2292. 1172 * Note: this constraint is removed in RFC3542 1173 */ 1174 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1175 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1176 IPPROTO_IPV6); 1177 if (*mp) 1178 mp = &(*mp)->m_next; 1179 #ifdef PULLDOWN_TEST 1180 m_freem(ext); 1181 #endif 1182 } 1183 } 1184 1185 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1186 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1187 1188 /* 1189 * Search for destination options headers or routing 1190 * header(s) through the header chain, and stores each 1191 * header as ancillary data. 1192 * Note that the order of the headers remains in 1193 * the chain of ancillary data. 1194 */ 1195 while (1) { /* is explicit loop prevention necessary? */ 1196 struct ip6_ext *ip6e = NULL; 1197 int elen; 1198 #ifdef PULLDOWN_TEST 1199 struct mbuf *ext = NULL; 1200 #endif 1201 1202 /* 1203 * if it is not an extension header, don't try to 1204 * pull it from the chain. 1205 */ 1206 switch (nxt) { 1207 case IPPROTO_DSTOPTS: 1208 case IPPROTO_ROUTING: 1209 case IPPROTO_HOPOPTS: 1210 case IPPROTO_AH: /* is it possible? */ 1211 break; 1212 default: 1213 goto loopend; 1214 } 1215 1216 #ifndef PULLDOWN_TEST 1217 if (off + sizeof(*ip6e) > m->m_len) 1218 goto loopend; 1219 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1220 if (nxt == IPPROTO_AH) 1221 elen = (ip6e->ip6e_len + 2) << 2; 1222 else 1223 elen = (ip6e->ip6e_len + 1) << 3; 1224 if (off + elen > m->m_len) 1225 goto loopend; 1226 #else 1227 ext = ip6_pullexthdr(m, off, nxt); 1228 if (ext == NULL) { 1229 V_ip6stat.ip6s_tooshort++; 1230 return; 1231 } 1232 ip6e = mtod(ext, struct ip6_ext *); 1233 if (nxt == IPPROTO_AH) 1234 elen = (ip6e->ip6e_len + 2) << 2; 1235 else 1236 elen = (ip6e->ip6e_len + 1) << 3; 1237 if (elen != ext->m_len) { 1238 m_freem(ext); 1239 V_ip6stat.ip6s_tooshort++; 1240 return; 1241 } 1242 #endif 1243 1244 switch (nxt) { 1245 case IPPROTO_DSTOPTS: 1246 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1247 break; 1248 1249 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1250 IS2292(in6p, 1251 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1252 IPPROTO_IPV6); 1253 if (*mp) 1254 mp = &(*mp)->m_next; 1255 break; 1256 case IPPROTO_ROUTING: 1257 if (!in6p->in6p_flags & IN6P_RTHDR) 1258 break; 1259 1260 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1261 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1262 IPPROTO_IPV6); 1263 if (*mp) 1264 mp = &(*mp)->m_next; 1265 break; 1266 case IPPROTO_HOPOPTS: 1267 case IPPROTO_AH: /* is it possible? */ 1268 break; 1269 1270 default: 1271 /* 1272 * other cases have been filtered in the above. 1273 * none will visit this case. here we supply 1274 * the code just in case (nxt overwritten or 1275 * other cases). 1276 */ 1277 #ifdef PULLDOWN_TEST 1278 m_freem(ext); 1279 #endif 1280 goto loopend; 1281 1282 } 1283 1284 /* proceed with the next header. */ 1285 off += elen; 1286 nxt = ip6e->ip6e_nxt; 1287 ip6e = NULL; 1288 #ifdef PULLDOWN_TEST 1289 m_freem(ext); 1290 ext = NULL; 1291 #endif 1292 } 1293 loopend: 1294 ; 1295 } 1296 } 1297 #undef IS2292 1298 1299 void 1300 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1301 { 1302 struct socket *so; 1303 struct mbuf *m_mtu; 1304 struct ip6_mtuinfo mtuctl; 1305 1306 so = in6p->inp_socket; 1307 1308 if (mtu == NULL) 1309 return; 1310 1311 #ifdef DIAGNOSTIC 1312 if (so == NULL) /* I believe this is impossible */ 1313 panic("ip6_notify_pmtu: socket is NULL"); 1314 #endif 1315 1316 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1317 mtuctl.ip6m_mtu = *mtu; 1318 mtuctl.ip6m_addr = *dst; 1319 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1320 return; 1321 1322 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1323 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1324 return; 1325 1326 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1327 == 0) { 1328 m_freem(m_mtu); 1329 /* XXX: should count statistics */ 1330 } else 1331 sorwakeup(so); 1332 1333 return; 1334 } 1335 1336 #ifdef PULLDOWN_TEST 1337 /* 1338 * pull single extension header from mbuf chain. returns single mbuf that 1339 * contains the result, or NULL on error. 1340 */ 1341 static struct mbuf * 1342 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1343 { 1344 struct ip6_ext ip6e; 1345 size_t elen; 1346 struct mbuf *n; 1347 1348 #ifdef DIAGNOSTIC 1349 switch (nxt) { 1350 case IPPROTO_DSTOPTS: 1351 case IPPROTO_ROUTING: 1352 case IPPROTO_HOPOPTS: 1353 case IPPROTO_AH: /* is it possible? */ 1354 break; 1355 default: 1356 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1357 } 1358 #endif 1359 1360 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1361 if (nxt == IPPROTO_AH) 1362 elen = (ip6e.ip6e_len + 2) << 2; 1363 else 1364 elen = (ip6e.ip6e_len + 1) << 3; 1365 1366 MGET(n, M_DONTWAIT, MT_DATA); 1367 if (n && elen >= MLEN) { 1368 MCLGET(n, M_DONTWAIT); 1369 if ((n->m_flags & M_EXT) == 0) { 1370 m_free(n); 1371 n = NULL; 1372 } 1373 } 1374 if (!n) 1375 return NULL; 1376 1377 n->m_len = 0; 1378 if (elen >= M_TRAILINGSPACE(n)) { 1379 m_free(n); 1380 return NULL; 1381 } 1382 1383 m_copydata(m, off, elen, mtod(n, caddr_t)); 1384 n->m_len = elen; 1385 return n; 1386 } 1387 #endif 1388 1389 /* 1390 * Get pointer to the previous header followed by the header 1391 * currently processed. 1392 * XXX: This function supposes that 1393 * M includes all headers, 1394 * the next header field and the header length field of each header 1395 * are valid, and 1396 * the sum of each header length equals to OFF. 1397 * Because of these assumptions, this function must be called very 1398 * carefully. Moreover, it will not be used in the near future when 1399 * we develop `neater' mechanism to process extension headers. 1400 */ 1401 char * 1402 ip6_get_prevhdr(struct mbuf *m, int off) 1403 { 1404 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1405 1406 if (off == sizeof(struct ip6_hdr)) 1407 return (&ip6->ip6_nxt); 1408 else { 1409 int len, nxt; 1410 struct ip6_ext *ip6e = NULL; 1411 1412 nxt = ip6->ip6_nxt; 1413 len = sizeof(struct ip6_hdr); 1414 while (len < off) { 1415 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1416 1417 switch (nxt) { 1418 case IPPROTO_FRAGMENT: 1419 len += sizeof(struct ip6_frag); 1420 break; 1421 case IPPROTO_AH: 1422 len += (ip6e->ip6e_len + 2) << 2; 1423 break; 1424 default: 1425 len += (ip6e->ip6e_len + 1) << 3; 1426 break; 1427 } 1428 nxt = ip6e->ip6e_nxt; 1429 } 1430 if (ip6e) 1431 return (&ip6e->ip6e_nxt); 1432 else 1433 return NULL; 1434 } 1435 } 1436 1437 /* 1438 * get next header offset. m will be retained. 1439 */ 1440 int 1441 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1442 { 1443 struct ip6_hdr ip6; 1444 struct ip6_ext ip6e; 1445 struct ip6_frag fh; 1446 1447 /* just in case */ 1448 if (m == NULL) 1449 panic("ip6_nexthdr: m == NULL"); 1450 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1451 return -1; 1452 1453 switch (proto) { 1454 case IPPROTO_IPV6: 1455 if (m->m_pkthdr.len < off + sizeof(ip6)) 1456 return -1; 1457 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1458 if (nxtp) 1459 *nxtp = ip6.ip6_nxt; 1460 off += sizeof(ip6); 1461 return off; 1462 1463 case IPPROTO_FRAGMENT: 1464 /* 1465 * terminate parsing if it is not the first fragment, 1466 * it does not make sense to parse through it. 1467 */ 1468 if (m->m_pkthdr.len < off + sizeof(fh)) 1469 return -1; 1470 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1471 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1472 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1473 return -1; 1474 if (nxtp) 1475 *nxtp = fh.ip6f_nxt; 1476 off += sizeof(struct ip6_frag); 1477 return off; 1478 1479 case IPPROTO_AH: 1480 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1481 return -1; 1482 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1483 if (nxtp) 1484 *nxtp = ip6e.ip6e_nxt; 1485 off += (ip6e.ip6e_len + 2) << 2; 1486 return off; 1487 1488 case IPPROTO_HOPOPTS: 1489 case IPPROTO_ROUTING: 1490 case IPPROTO_DSTOPTS: 1491 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1492 return -1; 1493 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1494 if (nxtp) 1495 *nxtp = ip6e.ip6e_nxt; 1496 off += (ip6e.ip6e_len + 1) << 3; 1497 return off; 1498 1499 case IPPROTO_NONE: 1500 case IPPROTO_ESP: 1501 case IPPROTO_IPCOMP: 1502 /* give up */ 1503 return -1; 1504 1505 default: 1506 return -1; 1507 } 1508 1509 return -1; 1510 } 1511 1512 /* 1513 * get offset for the last header in the chain. m will be kept untainted. 1514 */ 1515 int 1516 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1517 { 1518 int newoff; 1519 int nxt; 1520 1521 if (!nxtp) { 1522 nxt = -1; 1523 nxtp = &nxt; 1524 } 1525 while (1) { 1526 newoff = ip6_nexthdr(m, off, proto, nxtp); 1527 if (newoff < 0) 1528 return off; 1529 else if (newoff < off) 1530 return -1; /* invalid */ 1531 else if (newoff == off) 1532 return newoff; 1533 1534 off = newoff; 1535 proto = *nxtp; 1536 } 1537 } 1538 1539 struct ip6aux * 1540 ip6_addaux(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 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1547 M_NOWAIT); 1548 if (mtag) { 1549 m_tag_prepend(m, mtag); 1550 bzero(mtag + 1, sizeof(struct ip6aux)); 1551 } 1552 } 1553 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1554 } 1555 1556 struct ip6aux * 1557 ip6_findaux(struct mbuf *m) 1558 { 1559 struct m_tag *mtag; 1560 1561 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1562 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1563 } 1564 1565 void 1566 ip6_delaux(struct mbuf *m) 1567 { 1568 struct m_tag *mtag; 1569 1570 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1571 if (mtag) 1572 m_tag_delete(m, mtag); 1573 } 1574 1575 /* 1576 * System control for IP6 1577 */ 1578 1579 u_char inet6ctlerrmap[PRC_NCMDS] = { 1580 0, 0, 0, 0, 1581 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1582 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1583 EMSGSIZE, EHOSTUNREACH, 0, 0, 1584 0, 0, 0, 0, 1585 ENOPROTOOPT 1586 }; 1587