ip6_input.c revision 121742
1/* $FreeBSD: head/sys/netinet6/ip6_input.c 121742 2003-10-30 15:29:17Z ume $ */ 2/* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 3 4/* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33/* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 66 */ 67 68#include "opt_ip6fw.h" 69#include "opt_inet.h" 70#include "opt_inet6.h" 71#include "opt_ipsec.h" 72#include "opt_pfil_hooks.h" 73#include "opt_random_ip_id.h" 74 75#include <sys/param.h> 76#include <sys/systm.h> 77#include <sys/malloc.h> 78#include <sys/mbuf.h> 79#include <sys/proc.h> 80#include <sys/domain.h> 81#include <sys/protosw.h> 82#include <sys/socket.h> 83#include <sys/socketvar.h> 84#include <sys/errno.h> 85#include <sys/time.h> 86#include <sys/kernel.h> 87#include <sys/syslog.h> 88 89#include <net/if.h> 90#include <net/if_types.h> 91#include <net/if_dl.h> 92#include <net/route.h> 93#include <net/netisr.h> 94#ifdef PFIL_HOOKS 95#include <net/pfil.h> 96#endif 97 98#include <netinet/in.h> 99#include <netinet/in_systm.h> 100#ifdef INET 101#include <netinet/ip.h> 102#include <netinet/ip_icmp.h> 103#endif /* INET */ 104#include <netinet/ip6.h> 105#include <netinet6/in6_var.h> 106#include <netinet6/ip6_var.h> 107#include <netinet/in_pcb.h> 108#include <netinet/icmp6.h> 109#include <netinet6/scope6_var.h> 110#include <netinet6/in6_ifattach.h> 111#include <netinet6/nd6.h> 112#include <netinet6/in6_prefix.h> 113 114#ifdef IPSEC 115#include <netinet6/ipsec.h> 116#ifdef INET6 117#include <netinet6/ipsec6.h> 118#endif 119#endif 120 121#ifdef FAST_IPSEC 122#include <netipsec/ipsec.h> 123#include <netipsec/ipsec6.h> 124#define IPSEC 125#endif /* FAST_IPSEC */ 126 127#include <netinet6/ip6_fw.h> 128 129#include <netinet6/ip6protosw.h> 130 131#include <net/net_osdep.h> 132 133extern struct domain inet6domain; 134 135u_char ip6_protox[IPPROTO_MAX]; 136static struct ifqueue ip6intrq; 137static int ip6qmaxlen = IFQ_MAXLEN; 138struct in6_ifaddr *in6_ifaddr; 139 140extern struct callout in6_tmpaddrtimer_ch; 141 142int ip6_forward_srcrt; /* XXX */ 143int ip6_sourcecheck; /* XXX */ 144int ip6_sourcecheck_interval; /* XXX */ 145 146int ip6_ours_check_algorithm; 147 148#ifdef PFIL_HOOKS 149struct pfil_head inet6_pfil_hook; 150#endif 151 152/* firewall hooks */ 153ip6_fw_chk_t *ip6_fw_chk_ptr; 154ip6_fw_ctl_t *ip6_fw_ctl_ptr; 155int ip6_fw_enable = 1; 156 157struct ip6stat ip6stat; 158 159static void ip6_init2 __P((void *)); 160static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 161static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 162#ifdef PULLDOWN_TEST 163static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 164#endif 165 166/* 167 * IP6 initialization: fill in IP6 protocol switch table. 168 * All protocols not implemented in kernel go to raw IP6 protocol handler. 169 */ 170void 171ip6_init() 172{ 173 struct ip6protosw *pr; 174 int i; 175 176#ifdef DIAGNOSTIC 177 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 178 panic("sizeof(protosw) != sizeof(ip6protosw)"); 179#endif 180 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 181 if (pr == 0) 182 panic("ip6_init"); 183 for (i = 0; i < IPPROTO_MAX; i++) 184 ip6_protox[i] = pr - inet6sw; 185 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 186 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 187 if (pr->pr_domain->dom_family == PF_INET6 && 188 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 189 ip6_protox[pr->pr_protocol] = pr - inet6sw; 190#ifdef PFIL_HOOKS 191 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 192 inet6_pfil_hook.ph_af = AF_INET6; 193 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 194 printf("%s: WARNING: unable to register pfil hook, " 195 "error %d\n", __func__, i); 196#endif /* PFIL_HOOKS */ 197 ip6intrq.ifq_maxlen = ip6qmaxlen; 198 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 199 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq); 200 scope6_init(); 201 addrsel_policy_init(); 202 nd6_init(); 203 frag6_init(); 204#ifndef RANDOM_IP_ID 205 ip6_flow_seq = arc4random(); 206#endif 207 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 208} 209 210static void 211ip6_init2(dummy) 212 void *dummy; 213{ 214 215 /* nd6_timer_init */ 216 callout_init(&nd6_timer_ch, 0); 217 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 218 219 /* router renumbering prefix list maintenance */ 220 callout_init(&in6_rr_timer_ch, 0); 221 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 222 223 /* timer for regeneranation of temporary addresses randomize ID */ 224 callout_reset(&in6_tmpaddrtimer_ch, 225 (ip6_temp_preferred_lifetime - ip6_desync_factor - 226 ip6_temp_regen_advance) * hz, 227 in6_tmpaddrtimer, NULL); 228} 229 230/* cheat */ 231/* This must be after route_init(), which is now SI_ORDER_THIRD */ 232SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 233 234extern struct route_in6 ip6_forward_rt; 235 236void 237ip6_input(m) 238 struct mbuf *m; 239{ 240 struct ip6_hdr *ip6; 241 int off = sizeof(struct ip6_hdr), nest; 242 u_int32_t plen; 243 u_int32_t rtalert = ~0; 244 int nxt, ours = 0; 245 struct ifnet *deliverifp = NULL; 246#ifdef PFIL_HOOKS 247 struct in6_addr odst; 248#endif 249 int srcrt = 0; 250 251#ifdef IPSEC 252 /* 253 * should the inner packet be considered authentic? 254 * see comment in ah4_input(). 255 */ 256 if (m) { 257 m->m_flags &= ~M_AUTHIPHDR; 258 m->m_flags &= ~M_AUTHIPDGM; 259 } 260#endif 261 262 /* 263 * make sure we don't have onion peering information into m_tag. 264 */ 265 ip6_delaux(m); 266 267 /* 268 * mbuf statistics 269 */ 270 if (m->m_flags & M_EXT) { 271 if (m->m_next) 272 ip6stat.ip6s_mext2m++; 273 else 274 ip6stat.ip6s_mext1++; 275 } else { 276#define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 277 if (m->m_next) { 278 if (m->m_flags & M_LOOP) { 279 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 280 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 281 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 282 else 283 ip6stat.ip6s_m2m[0]++; 284 } else 285 ip6stat.ip6s_m1++; 286#undef M2MMAX 287 } 288 289 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 290 ip6stat.ip6s_total++; 291 292#ifndef PULLDOWN_TEST 293 /* 294 * L2 bridge code and some other code can return mbuf chain 295 * that does not conform to KAME requirement. too bad. 296 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 297 */ 298 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 299 struct mbuf *n; 300 301 MGETHDR(n, M_DONTWAIT, MT_HEADER); 302 if (n) 303 M_MOVE_PKTHDR(n, m); 304 if (n && n->m_pkthdr.len > MHLEN) { 305 MCLGET(n, M_DONTWAIT); 306 if ((n->m_flags & M_EXT) == 0) { 307 m_freem(n); 308 n = NULL; 309 } 310 } 311 if (n == NULL) { 312 m_freem(m); 313 return; /* ENOBUFS */ 314 } 315 316 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 317 n->m_len = n->m_pkthdr.len; 318 m_freem(m); 319 m = n; 320 } 321 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 322#endif 323 324 if (m->m_len < sizeof(struct ip6_hdr)) { 325 struct ifnet *inifp; 326 inifp = m->m_pkthdr.rcvif; 327 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 328 ip6stat.ip6s_toosmall++; 329 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 330 return; 331 } 332 } 333 334 ip6 = mtod(m, struct ip6_hdr *); 335 336 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 337 ip6stat.ip6s_badvers++; 338 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 339 goto bad; 340 } 341 342#ifdef PFIL_HOOKS 343 /* 344 * Run through list of hooks for input packets. 345 * 346 * NB: Beware of the destination address changing 347 * (e.g. by NAT rewriting). When this happens, 348 * tell ip6_forward to do the right thing. 349 */ 350 odst = ip6->ip6_dst; 351 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 352 return; 353 if (m == NULL) /* consumed by filter */ 354 return; 355 ip6 = mtod(m, struct ip6_hdr *); 356 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 357#endif /* PFIL_HOOKS */ 358 359 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 360 361 /* 362 * Check with the firewall... 363 */ 364 if (ip6_fw_enable && ip6_fw_chk_ptr) { 365 u_short port = 0; 366 /* If ipfw says divert, we have to just drop packet */ 367 /* use port as a dummy argument */ 368 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 369 m_freem(m); 370 m = NULL; 371 } 372 if (!m) 373 return; 374 } 375 376 /* 377 * Check against address spoofing/corruption. 378 */ 379 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 380 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 381 /* 382 * XXX: "badscope" is not very suitable for a multicast source. 383 */ 384 ip6stat.ip6s_badscope++; 385 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 386 goto bad; 387 } 388 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 389 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 390 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 391 ip6stat.ip6s_badscope++; 392 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 393 goto bad; 394 } 395 396 /* 397 * The following check is not documented in specs. A malicious 398 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 399 * and bypass security checks (act as if it was from 127.0.0.1 by using 400 * IPv6 src ::ffff:127.0.0.1). Be cautious. 401 * 402 * This check chokes if we are in an SIIT cloud. As none of BSDs 403 * support IPv4-less kernel compilation, we cannot support SIIT 404 * environment at all. So, it makes more sense for us to reject any 405 * malicious packets for non-SIIT environment, than try to do a 406 * partial support for SIIT environment. 407 */ 408 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 409 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 410 ip6stat.ip6s_badscope++; 411 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 412 goto bad; 413 } 414#if 0 415 /* 416 * Reject packets with IPv4 compatible addresses (auto tunnel). 417 * 418 * The code forbids auto tunnel relay case in RFC1933 (the check is 419 * stronger than RFC1933). We may want to re-enable it if mech-xx 420 * is revised to forbid relaying case. 421 */ 422 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 423 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 424 ip6stat.ip6s_badscope++; 425 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 426 goto bad; 427 } 428#endif 429 430 /* drop packets if interface ID portion is already filled */ 431 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 432 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 433 ip6->ip6_src.s6_addr16[1]) { 434 ip6stat.ip6s_badscope++; 435 goto bad; 436 } 437 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) || 438 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) && 439 ip6->ip6_dst.s6_addr16[1]) { 440 ip6stat.ip6s_badscope++; 441 goto bad; 442 } 443 } 444 445 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 446 ip6->ip6_src.s6_addr16[1] 447 = htons(m->m_pkthdr.rcvif->if_index); 448 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 449 ip6->ip6_dst.s6_addr16[1] 450 = htons(m->m_pkthdr.rcvif->if_index); 451 452 /* 453 * Multicast check 454 */ 455 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 456 struct in6_multi *in6m = 0; 457 458 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 459 /* 460 * See if we belong to the destination multicast group on the 461 * arrival interface. 462 */ 463 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 464 if (in6m) 465 ours = 1; 466 else if (!ip6_mrouter) { 467 ip6stat.ip6s_notmember++; 468 ip6stat.ip6s_cantforward++; 469 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 470 goto bad; 471 } 472 deliverifp = m->m_pkthdr.rcvif; 473 goto hbhcheck; 474 } 475 476 /* 477 * Unicast check 478 */ 479 if (ip6_forward_rt.ro_rt != NULL && 480 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 481 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 482 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 483 ip6stat.ip6s_forward_cachehit++; 484 else { 485 struct sockaddr_in6 *dst6; 486 487 if (ip6_forward_rt.ro_rt) { 488 /* route is down or destination is different */ 489 ip6stat.ip6s_forward_cachemiss++; 490 RTFREE(ip6_forward_rt.ro_rt); 491 ip6_forward_rt.ro_rt = 0; 492 } 493 494 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 495 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 496 dst6->sin6_len = sizeof(struct sockaddr_in6); 497 dst6->sin6_family = AF_INET6; 498 dst6->sin6_addr = ip6->ip6_dst; 499 500 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 501 } 502 503#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 504 505 /* 506 * Accept the packet if the forwarding interface to the destination 507 * according to the routing table is the loopback interface, 508 * unless the associated route has a gateway. 509 * Note that this approach causes to accept a packet if there is a 510 * route to the loopback interface for the destination of the packet. 511 * But we think it's even useful in some situations, e.g. when using 512 * a special daemon which wants to intercept the packet. 513 * 514 * XXX: some OSes automatically make a cloned route for the destination 515 * of an outgoing packet. If the outgoing interface of the packet 516 * is a loopback one, the kernel would consider the packet to be 517 * accepted, even if we have no such address assinged on the interface. 518 * We check the cloned flag of the route entry to reject such cases, 519 * assuming that route entries for our own addresses are not made by 520 * cloning (it should be true because in6_addloop explicitly installs 521 * the host route). However, we might have to do an explicit check 522 * while it would be less efficient. Or, should we rather install a 523 * reject route for such a case? 524 */ 525 if (ip6_forward_rt.ro_rt && 526 (ip6_forward_rt.ro_rt->rt_flags & 527 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 528#ifdef RTF_WASCLONED 529 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 530#endif 531#ifdef RTF_CLONED 532 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 533#endif 534#if 0 535 /* 536 * The check below is redundant since the comparison of 537 * the destination and the key of the rtentry has 538 * already done through looking up the routing table. 539 */ 540 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 541 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 542#endif 543 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 544 struct in6_ifaddr *ia6 = 545 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 546 547 /* 548 * record address information into m_tag. 549 */ 550 (void)ip6_setdstifaddr(m, ia6); 551 552 /* 553 * packets to a tentative, duplicated, or somehow invalid 554 * address must not be accepted. 555 */ 556 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 557 /* this address is ready */ 558 ours = 1; 559 deliverifp = ia6->ia_ifp; /* correct? */ 560 /* Count the packet in the ip address stats */ 561 ia6->ia_ifa.if_ipackets++; 562 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 563 goto hbhcheck; 564 } else { 565 /* address is not ready, so discard the packet. */ 566 nd6log((LOG_INFO, 567 "ip6_input: packet to an unready address %s->%s\n", 568 ip6_sprintf(&ip6->ip6_src), 569 ip6_sprintf(&ip6->ip6_dst))); 570 571 goto bad; 572 } 573 } 574 575 /* 576 * FAITH (Firewall Aided Internet Translator) 577 */ 578 if (ip6_keepfaith) { 579 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 580 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 581 /* XXX do we need more sanity checks? */ 582 ours = 1; 583 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 584 goto hbhcheck; 585 } 586 } 587 588 /* 589 * Now there is no reason to process the packet if it's not our own 590 * and we're not a router. 591 */ 592 if (!ip6_forwarding) { 593 ip6stat.ip6s_cantforward++; 594 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 595 goto bad; 596 } 597 598 hbhcheck: 599 /* 600 * record address information into m_tag, if we don't have one yet. 601 * note that we are unable to record it, if the address is not listed 602 * as our interface address (e.g. multicast addresses, addresses 603 * within FAITH prefixes and such). 604 */ 605 if (deliverifp && !ip6_getdstifaddr(m)) { 606 struct in6_ifaddr *ia6; 607 608 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 609 if (ia6) { 610 if (!ip6_setdstifaddr(m, ia6)) { 611 /* 612 * XXX maybe we should drop the packet here, 613 * as we could not provide enough information 614 * to the upper layers. 615 */ 616 } 617 } 618 } 619 620 /* 621 * Process Hop-by-Hop options header if it's contained. 622 * m may be modified in ip6_hopopts_input(). 623 * If a JumboPayload option is included, plen will also be modified. 624 */ 625 plen = (u_int32_t)ntohs(ip6->ip6_plen); 626 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 627 struct ip6_hbh *hbh; 628 629 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 630#if 0 /*touches NULL pointer*/ 631 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 632#endif 633 return; /* m have already been freed */ 634 } 635 636 /* adjust pointer */ 637 ip6 = mtod(m, struct ip6_hdr *); 638 639 /* 640 * if the payload length field is 0 and the next header field 641 * indicates Hop-by-Hop Options header, then a Jumbo Payload 642 * option MUST be included. 643 */ 644 if (ip6->ip6_plen == 0 && plen == 0) { 645 /* 646 * Note that if a valid jumbo payload option is 647 * contained, ip6_hopopts_input() must set a valid 648 * (non-zero) payload length to the variable plen. 649 */ 650 ip6stat.ip6s_badoptions++; 651 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 652 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 653 icmp6_error(m, ICMP6_PARAM_PROB, 654 ICMP6_PARAMPROB_HEADER, 655 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 656 return; 657 } 658#ifndef PULLDOWN_TEST 659 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 660 hbh = (struct ip6_hbh *)(ip6 + 1); 661#else 662 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 663 sizeof(struct ip6_hbh)); 664 if (hbh == NULL) { 665 ip6stat.ip6s_tooshort++; 666 return; 667 } 668#endif 669 nxt = hbh->ip6h_nxt; 670 671 /* 672 * accept the packet if a router alert option is included 673 * and we act as an IPv6 router. 674 */ 675 if (rtalert != ~0 && ip6_forwarding) 676 ours = 1; 677 } else 678 nxt = ip6->ip6_nxt; 679 680 /* 681 * Check that the amount of data in the buffers 682 * is as at least much as the IPv6 header would have us expect. 683 * Trim mbufs if longer than we expect. 684 * Drop packet if shorter than we expect. 685 */ 686 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 687 ip6stat.ip6s_tooshort++; 688 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 689 goto bad; 690 } 691 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 692 if (m->m_len == m->m_pkthdr.len) { 693 m->m_len = sizeof(struct ip6_hdr) + plen; 694 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 695 } else 696 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 697 } 698 699 /* 700 * Forward if desirable. 701 */ 702 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 703 /* 704 * If we are acting as a multicast router, all 705 * incoming multicast packets are passed to the 706 * kernel-level multicast forwarding function. 707 * The packet is returned (relatively) intact; if 708 * ip6_mforward() returns a non-zero value, the packet 709 * must be discarded, else it may be accepted below. 710 */ 711 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 712 ip6stat.ip6s_cantforward++; 713 m_freem(m); 714 return; 715 } 716 if (!ours) { 717 m_freem(m); 718 return; 719 } 720 } else if (!ours) { 721 ip6_forward(m, srcrt); 722 return; 723 } 724 725 ip6 = mtod(m, struct ip6_hdr *); 726 727 /* 728 * Malicious party may be able to use IPv4 mapped addr to confuse 729 * tcp/udp stack and bypass security checks (act as if it was from 730 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 731 * 732 * For SIIT end node behavior, you may want to disable the check. 733 * However, you will become vulnerable to attacks using IPv4 mapped 734 * source. 735 */ 736 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 737 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 738 ip6stat.ip6s_badscope++; 739 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 740 goto bad; 741 } 742 743 /* 744 * Tell launch routine the next header 745 */ 746 ip6stat.ip6s_delivered++; 747 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 748 nest = 0; 749 750 while (nxt != IPPROTO_DONE) { 751 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 752 ip6stat.ip6s_toomanyhdr++; 753 goto bad; 754 } 755 756 /* 757 * protection against faulty packet - there should be 758 * more sanity checks in header chain processing. 759 */ 760 if (m->m_pkthdr.len < off) { 761 ip6stat.ip6s_tooshort++; 762 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 763 goto bad; 764 } 765 766#ifdef IPSEC 767 /* 768 * enforce IPsec policy checking if we are seeing last header. 769 * note that we do not visit this with protocols with pcb layer 770 * code - like udp/tcp/raw ip. 771 */ 772 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 773 ipsec6_in_reject(m, NULL)) { 774 ipsec6stat.in_polvio++; 775 goto bad; 776 } 777#endif 778 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 779 } 780 return; 781 bad: 782 m_freem(m); 783} 784 785/* 786 * set/grab in6_ifaddr correspond to IPv6 destination address. 787 * XXX backward compatibility wrapper 788 */ 789static struct ip6aux * 790ip6_setdstifaddr(m, ia6) 791 struct mbuf *m; 792 struct in6_ifaddr *ia6; 793{ 794 struct ip6aux *ip6a; 795 796 ip6a = ip6_addaux(m); 797 if (ip6a) 798 ip6a->ip6a_dstia6 = ia6; 799 return ip6a; /* NULL if failed to set */ 800} 801 802struct in6_ifaddr * 803ip6_getdstifaddr(m) 804 struct mbuf *m; 805{ 806 struct ip6aux *ip6a; 807 808 ip6a = ip6_findaux(m); 809 if (ip6a) 810 return ip6a->ip6a_dstia6; 811 else 812 return NULL; 813} 814 815/* 816 * Hop-by-Hop options header processing. If a valid jumbo payload option is 817 * included, the real payload length will be stored in plenp. 818 */ 819static int 820ip6_hopopts_input(plenp, rtalertp, mp, offp) 821 u_int32_t *plenp; 822 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 823 struct mbuf **mp; 824 int *offp; 825{ 826 struct mbuf *m = *mp; 827 int off = *offp, hbhlen; 828 struct ip6_hbh *hbh; 829 u_int8_t *opt; 830 831 /* validation of the length of the header */ 832#ifndef PULLDOWN_TEST 833 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 834 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 835 hbhlen = (hbh->ip6h_len + 1) << 3; 836 837 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 838 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 839#else 840 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 841 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 842 if (hbh == NULL) { 843 ip6stat.ip6s_tooshort++; 844 return -1; 845 } 846 hbhlen = (hbh->ip6h_len + 1) << 3; 847 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 848 hbhlen); 849 if (hbh == NULL) { 850 ip6stat.ip6s_tooshort++; 851 return -1; 852 } 853#endif 854 off += hbhlen; 855 hbhlen -= sizeof(struct ip6_hbh); 856 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 857 858 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 859 hbhlen, rtalertp, plenp) < 0) 860 return (-1); 861 862 *offp = off; 863 *mp = m; 864 return (0); 865} 866 867/* 868 * Search header for all Hop-by-hop options and process each option. 869 * This function is separate from ip6_hopopts_input() in order to 870 * handle a case where the sending node itself process its hop-by-hop 871 * options header. In such a case, the function is called from ip6_output(). 872 * 873 * The function assumes that hbh header is located right after the IPv6 header 874 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 875 * opthead + hbhlen is located in continuous memory region. 876 */ 877int 878ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 879 struct mbuf *m; 880 u_int8_t *opthead; 881 int hbhlen; 882 u_int32_t *rtalertp; 883 u_int32_t *plenp; 884{ 885 struct ip6_hdr *ip6; 886 int optlen = 0; 887 u_int8_t *opt = opthead; 888 u_int16_t rtalert_val; 889 u_int32_t jumboplen; 890 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 891 892 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 893 switch (*opt) { 894 case IP6OPT_PAD1: 895 optlen = 1; 896 break; 897 case IP6OPT_PADN: 898 if (hbhlen < IP6OPT_MINLEN) { 899 ip6stat.ip6s_toosmall++; 900 goto bad; 901 } 902 optlen = *(opt + 1) + 2; 903 break; 904 case IP6OPT_ROUTER_ALERT: 905 /* XXX may need check for alignment */ 906 if (hbhlen < IP6OPT_RTALERT_LEN) { 907 ip6stat.ip6s_toosmall++; 908 goto bad; 909 } 910 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 911 /* XXX stat */ 912 icmp6_error(m, ICMP6_PARAM_PROB, 913 ICMP6_PARAMPROB_HEADER, 914 erroff + opt + 1 - opthead); 915 return (-1); 916 } 917 optlen = IP6OPT_RTALERT_LEN; 918 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 919 *rtalertp = ntohs(rtalert_val); 920 break; 921 case IP6OPT_JUMBO: 922 /* XXX may need check for alignment */ 923 if (hbhlen < IP6OPT_JUMBO_LEN) { 924 ip6stat.ip6s_toosmall++; 925 goto bad; 926 } 927 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 928 /* XXX stat */ 929 icmp6_error(m, ICMP6_PARAM_PROB, 930 ICMP6_PARAMPROB_HEADER, 931 erroff + opt + 1 - opthead); 932 return (-1); 933 } 934 optlen = IP6OPT_JUMBO_LEN; 935 936 /* 937 * IPv6 packets that have non 0 payload length 938 * must not contain a jumbo payload option. 939 */ 940 ip6 = mtod(m, struct ip6_hdr *); 941 if (ip6->ip6_plen) { 942 ip6stat.ip6s_badoptions++; 943 icmp6_error(m, ICMP6_PARAM_PROB, 944 ICMP6_PARAMPROB_HEADER, 945 erroff + opt - opthead); 946 return (-1); 947 } 948 949 /* 950 * We may see jumbolen in unaligned location, so 951 * we'd need to perform bcopy(). 952 */ 953 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 954 jumboplen = (u_int32_t)htonl(jumboplen); 955 956#if 1 957 /* 958 * if there are multiple jumbo payload options, 959 * *plenp will be non-zero and the packet will be 960 * rejected. 961 * the behavior may need some debate in ipngwg - 962 * multiple options does not make sense, however, 963 * there's no explicit mention in specification. 964 */ 965 if (*plenp != 0) { 966 ip6stat.ip6s_badoptions++; 967 icmp6_error(m, ICMP6_PARAM_PROB, 968 ICMP6_PARAMPROB_HEADER, 969 erroff + opt + 2 - opthead); 970 return (-1); 971 } 972#endif 973 974 /* 975 * jumbo payload length must be larger than 65535. 976 */ 977 if (jumboplen <= IPV6_MAXPACKET) { 978 ip6stat.ip6s_badoptions++; 979 icmp6_error(m, ICMP6_PARAM_PROB, 980 ICMP6_PARAMPROB_HEADER, 981 erroff + opt + 2 - opthead); 982 return (-1); 983 } 984 *plenp = jumboplen; 985 986 break; 987 default: /* unknown option */ 988 if (hbhlen < IP6OPT_MINLEN) { 989 ip6stat.ip6s_toosmall++; 990 goto bad; 991 } 992 optlen = ip6_unknown_opt(opt, m, 993 erroff + opt - opthead); 994 if (optlen == -1) 995 return (-1); 996 optlen += 2; 997 break; 998 } 999 } 1000 1001 return (0); 1002 1003 bad: 1004 m_freem(m); 1005 return (-1); 1006} 1007 1008/* 1009 * Unknown option processing. 1010 * The third argument `off' is the offset from the IPv6 header to the option, 1011 * which is necessary if the IPv6 header the and option header and IPv6 header 1012 * is not continuous in order to return an ICMPv6 error. 1013 */ 1014int 1015ip6_unknown_opt(optp, m, off) 1016 u_int8_t *optp; 1017 struct mbuf *m; 1018 int off; 1019{ 1020 struct ip6_hdr *ip6; 1021 1022 switch (IP6OPT_TYPE(*optp)) { 1023 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1024 return ((int)*(optp + 1)); 1025 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1026 m_freem(m); 1027 return (-1); 1028 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1029 ip6stat.ip6s_badoptions++; 1030 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1031 return (-1); 1032 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1033 ip6stat.ip6s_badoptions++; 1034 ip6 = mtod(m, struct ip6_hdr *); 1035 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1036 (m->m_flags & (M_BCAST|M_MCAST))) 1037 m_freem(m); 1038 else 1039 icmp6_error(m, ICMP6_PARAM_PROB, 1040 ICMP6_PARAMPROB_OPTION, off); 1041 return (-1); 1042 } 1043 1044 m_freem(m); /* XXX: NOTREACHED */ 1045 return (-1); 1046} 1047 1048/* 1049 * Create the "control" list for this pcb. 1050 * The function will not modify mbuf chain at all. 1051 * 1052 * with KAME mbuf chain restriction: 1053 * The routine will be called from upper layer handlers like tcp6_input(). 1054 * Thus the routine assumes that the caller (tcp6_input) have already 1055 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1056 * very first mbuf on the mbuf chain. 1057 */ 1058void 1059ip6_savecontrol(in6p, m, mp) 1060 struct inpcb *in6p; 1061 struct mbuf *m, **mp; 1062{ 1063#define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1064 struct thread *td = curthread; /* XXX */ 1065 int privileged = 0; 1066 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1067 1068 if (td && !suser(td)) 1069 privileged++; 1070 1071#ifdef SO_TIMESTAMP 1072 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1073 struct timeval tv; 1074 1075 microtime(&tv); 1076 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1077 SCM_TIMESTAMP, SOL_SOCKET); 1078 if (*mp) 1079 mp = &(*mp)->m_next; 1080 } 1081#endif 1082 1083 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1084 return; 1085 1086 /* RFC 2292 sec. 5 */ 1087 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1088 struct in6_pktinfo pi6; 1089 1090 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1091 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1092 pi6.ipi6_ifindex = 1093 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1094 1095 *mp = sbcreatecontrol((caddr_t) &pi6, 1096 sizeof(struct in6_pktinfo), 1097 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1098 if (*mp) 1099 mp = &(*mp)->m_next; 1100 } 1101 1102 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1103 int hlim = ip6->ip6_hlim & 0xff; 1104 1105 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1106 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1107 if (*mp) 1108 mp = &(*mp)->m_next; 1109 } 1110 1111 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1112 u_int32_t flowinfo; 1113 int tclass; 1114 1115 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1116 flowinfo >>= 20; 1117 1118 tclass = flowinfo & 0xff; 1119 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1120 IPV6_TCLASS, IPPROTO_IPV6); 1121 if (*mp) 1122 mp = &(*mp)->m_next; 1123 } 1124 1125 /* 1126 * IPV6_HOPOPTS socket option. We require super-user privilege 1127 * for the option, but it might be too strict, since there might 1128 * be some hop-by-hop options which can be returned to normal user. 1129 * See RFC 2292 section 6. 1130 */ 1131 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1132#ifdef DIAGNOSTIC 1133 if (!privileged) 1134 panic("IN6P_HOPOPTS is set for unprivileged socket"); 1135#endif 1136 /* 1137 * Check if a hop-by-hop options header is contatined in the 1138 * received packet, and if so, store the options as ancillary 1139 * data. Note that a hop-by-hop options header must be 1140 * just after the IPv6 header, which is assured through the 1141 * IPv6 input processing. 1142 */ 1143 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1144 struct ip6_hbh *hbh; 1145 int hbhlen = 0; 1146#ifdef PULLDOWN_TEST 1147 struct mbuf *ext; 1148#endif 1149 1150#ifndef PULLDOWN_TEST 1151 hbh = (struct ip6_hbh *)(ip6 + 1); 1152 hbhlen = (hbh->ip6h_len + 1) << 3; 1153#else 1154 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1155 ip6->ip6_nxt); 1156 if (ext == NULL) { 1157 ip6stat.ip6s_tooshort++; 1158 return; 1159 } 1160 hbh = mtod(ext, struct ip6_hbh *); 1161 hbhlen = (hbh->ip6h_len + 1) << 3; 1162 if (hbhlen != ext->m_len) { 1163 m_freem(ext); 1164 ip6stat.ip6s_tooshort++; 1165 return; 1166 } 1167#endif 1168 1169 /* 1170 * XXX: We copy the whole header even if a 1171 * jumbo payload option is included, the option which 1172 * is to be removed before returning according to 1173 * RFC2292. 1174 * Note: this constraint is removed in 2292bis. 1175 */ 1176 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1177 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1178 IPPROTO_IPV6); 1179 if (*mp) 1180 mp = &(*mp)->m_next; 1181#ifdef PULLDOWN_TEST 1182 m_freem(ext); 1183#endif 1184 } 1185 } 1186 1187 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1188 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1189 1190 /* 1191 * Search for destination options headers or routing 1192 * header(s) through the header chain, and stores each 1193 * header as ancillary data. 1194 * Note that the order of the headers remains in 1195 * the chain of ancillary data. 1196 */ 1197 while (1) { /* is explicit loop prevention necessary? */ 1198 struct ip6_ext *ip6e = NULL; 1199 int elen; 1200#ifdef PULLDOWN_TEST 1201 struct mbuf *ext = NULL; 1202#endif 1203 1204 /* 1205 * if it is not an extension header, don't try to 1206 * pull it from the chain. 1207 */ 1208 switch (nxt) { 1209 case IPPROTO_DSTOPTS: 1210 case IPPROTO_ROUTING: 1211 case IPPROTO_HOPOPTS: 1212 case IPPROTO_AH: /* is it possible? */ 1213 break; 1214 default: 1215 goto loopend; 1216 } 1217 1218#ifndef PULLDOWN_TEST 1219 if (off + sizeof(*ip6e) > m->m_len) 1220 goto loopend; 1221 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1222 if (nxt == IPPROTO_AH) 1223 elen = (ip6e->ip6e_len + 2) << 2; 1224 else 1225 elen = (ip6e->ip6e_len + 1) << 3; 1226 if (off + elen > m->m_len) 1227 goto loopend; 1228#else 1229 ext = ip6_pullexthdr(m, off, nxt); 1230 if (ext == NULL) { 1231 ip6stat.ip6s_tooshort++; 1232 return; 1233 } 1234 ip6e = mtod(ext, struct ip6_ext *); 1235 if (nxt == IPPROTO_AH) 1236 elen = (ip6e->ip6e_len + 2) << 2; 1237 else 1238 elen = (ip6e->ip6e_len + 1) << 3; 1239 if (elen != ext->m_len) { 1240 m_freem(ext); 1241 ip6stat.ip6s_tooshort++; 1242 return; 1243 } 1244#endif 1245 1246 switch (nxt) { 1247 case IPPROTO_DSTOPTS: 1248 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1249 break; 1250 1251 /* 1252 * We also require super-user privilege for 1253 * the option. See comments on IN6_HOPOPTS. 1254 */ 1255 if (!privileged) 1256 break; 1257 1258 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1259 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1260 IPPROTO_IPV6); 1261 if (*mp) 1262 mp = &(*mp)->m_next; 1263 break; 1264 case IPPROTO_ROUTING: 1265 if (!in6p->in6p_flags & IN6P_RTHDR) 1266 break; 1267 1268 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1269 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1270 IPPROTO_IPV6); 1271 if (*mp) 1272 mp = &(*mp)->m_next; 1273 break; 1274 case IPPROTO_HOPOPTS: 1275 case IPPROTO_AH: /* is it possible? */ 1276 break; 1277 1278 default: 1279 /* 1280 * other cases have been filtered in the above. 1281 * none will visit this case. here we supply 1282 * the code just in case (nxt overwritten or 1283 * other cases). 1284 */ 1285#ifdef PULLDOWN_TEST 1286 m_freem(ext); 1287#endif 1288 goto loopend; 1289 1290 } 1291 1292 /* proceed with the next header. */ 1293 off += elen; 1294 nxt = ip6e->ip6e_nxt; 1295 ip6e = NULL; 1296#ifdef PULLDOWN_TEST 1297 m_freem(ext); 1298 ext = NULL; 1299#endif 1300 } 1301 loopend: 1302 ; 1303 } 1304 1305#undef IS2292 1306} 1307 1308#ifdef PULLDOWN_TEST 1309/* 1310 * pull single extension header from mbuf chain. returns single mbuf that 1311 * contains the result, or NULL on error. 1312 */ 1313static struct mbuf * 1314ip6_pullexthdr(m, off, nxt) 1315 struct mbuf *m; 1316 size_t off; 1317 int nxt; 1318{ 1319 struct ip6_ext ip6e; 1320 size_t elen; 1321 struct mbuf *n; 1322 1323#ifdef DIAGNOSTIC 1324 switch (nxt) { 1325 case IPPROTO_DSTOPTS: 1326 case IPPROTO_ROUTING: 1327 case IPPROTO_HOPOPTS: 1328 case IPPROTO_AH: /* is it possible? */ 1329 break; 1330 default: 1331 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1332 } 1333#endif 1334 1335 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1336 if (nxt == IPPROTO_AH) 1337 elen = (ip6e.ip6e_len + 2) << 2; 1338 else 1339 elen = (ip6e.ip6e_len + 1) << 3; 1340 1341 MGET(n, M_DONTWAIT, MT_DATA); 1342 if (n && elen >= MLEN) { 1343 MCLGET(n, M_DONTWAIT); 1344 if ((n->m_flags & M_EXT) == 0) { 1345 m_free(n); 1346 n = NULL; 1347 } 1348 } 1349 if (!n) 1350 return NULL; 1351 1352 n->m_len = 0; 1353 if (elen >= M_TRAILINGSPACE(n)) { 1354 m_free(n); 1355 return NULL; 1356 } 1357 1358 m_copydata(m, off, elen, mtod(n, caddr_t)); 1359 n->m_len = elen; 1360 return n; 1361} 1362#endif 1363 1364/* 1365 * Get pointer to the previous header followed by the header 1366 * currently processed. 1367 * XXX: This function supposes that 1368 * M includes all headers, 1369 * the next header field and the header length field of each header 1370 * are valid, and 1371 * the sum of each header length equals to OFF. 1372 * Because of these assumptions, this function must be called very 1373 * carefully. Moreover, it will not be used in the near future when 1374 * we develop `neater' mechanism to process extension headers. 1375 */ 1376char * 1377ip6_get_prevhdr(m, off) 1378 struct mbuf *m; 1379 int off; 1380{ 1381 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1382 1383 if (off == sizeof(struct ip6_hdr)) 1384 return (&ip6->ip6_nxt); 1385 else { 1386 int len, nxt; 1387 struct ip6_ext *ip6e = NULL; 1388 1389 nxt = ip6->ip6_nxt; 1390 len = sizeof(struct ip6_hdr); 1391 while (len < off) { 1392 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1393 1394 switch (nxt) { 1395 case IPPROTO_FRAGMENT: 1396 len += sizeof(struct ip6_frag); 1397 break; 1398 case IPPROTO_AH: 1399 len += (ip6e->ip6e_len + 2) << 2; 1400 break; 1401 default: 1402 len += (ip6e->ip6e_len + 1) << 3; 1403 break; 1404 } 1405 nxt = ip6e->ip6e_nxt; 1406 } 1407 if (ip6e) 1408 return (&ip6e->ip6e_nxt); 1409 else 1410 return NULL; 1411 } 1412} 1413 1414/* 1415 * get next header offset. m will be retained. 1416 */ 1417int 1418ip6_nexthdr(m, off, proto, nxtp) 1419 struct mbuf *m; 1420 int off; 1421 int proto; 1422 int *nxtp; 1423{ 1424 struct ip6_hdr ip6; 1425 struct ip6_ext ip6e; 1426 struct ip6_frag fh; 1427 1428 /* just in case */ 1429 if (m == NULL) 1430 panic("ip6_nexthdr: m == NULL"); 1431 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1432 return -1; 1433 1434 switch (proto) { 1435 case IPPROTO_IPV6: 1436 if (m->m_pkthdr.len < off + sizeof(ip6)) 1437 return -1; 1438 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1439 if (nxtp) 1440 *nxtp = ip6.ip6_nxt; 1441 off += sizeof(ip6); 1442 return off; 1443 1444 case IPPROTO_FRAGMENT: 1445 /* 1446 * terminate parsing if it is not the first fragment, 1447 * it does not make sense to parse through it. 1448 */ 1449 if (m->m_pkthdr.len < off + sizeof(fh)) 1450 return -1; 1451 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1452 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1453 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1454 return -1; 1455 if (nxtp) 1456 *nxtp = fh.ip6f_nxt; 1457 off += sizeof(struct ip6_frag); 1458 return off; 1459 1460 case IPPROTO_AH: 1461 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1462 return -1; 1463 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1464 if (nxtp) 1465 *nxtp = ip6e.ip6e_nxt; 1466 off += (ip6e.ip6e_len + 2) << 2; 1467 return off; 1468 1469 case IPPROTO_HOPOPTS: 1470 case IPPROTO_ROUTING: 1471 case IPPROTO_DSTOPTS: 1472 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1473 return -1; 1474 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1475 if (nxtp) 1476 *nxtp = ip6e.ip6e_nxt; 1477 off += (ip6e.ip6e_len + 1) << 3; 1478 return off; 1479 1480 case IPPROTO_NONE: 1481 case IPPROTO_ESP: 1482 case IPPROTO_IPCOMP: 1483 /* give up */ 1484 return -1; 1485 1486 default: 1487 return -1; 1488 } 1489 1490 return -1; 1491} 1492 1493/* 1494 * get offset for the last header in the chain. m will be kept untainted. 1495 */ 1496int 1497ip6_lasthdr(m, off, proto, nxtp) 1498 struct mbuf *m; 1499 int off; 1500 int proto; 1501 int *nxtp; 1502{ 1503 int newoff; 1504 int nxt; 1505 1506 if (!nxtp) { 1507 nxt = -1; 1508 nxtp = &nxt; 1509 } 1510 while (1) { 1511 newoff = ip6_nexthdr(m, off, proto, nxtp); 1512 if (newoff < 0) 1513 return off; 1514 else if (newoff < off) 1515 return -1; /* invalid */ 1516 else if (newoff == off) 1517 return newoff; 1518 1519 off = newoff; 1520 proto = *nxtp; 1521 } 1522} 1523 1524struct ip6aux * 1525ip6_addaux(m) 1526 struct mbuf *m; 1527{ 1528 struct m_tag *mtag; 1529 1530 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1531 if (!mtag) { 1532 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1533 M_NOWAIT); 1534 if (mtag) { 1535 m_tag_prepend(m, mtag); 1536 bzero(mtag + 1, sizeof(struct ip6aux)); 1537 } 1538 } 1539 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1540} 1541 1542struct ip6aux * 1543ip6_findaux(m) 1544 struct mbuf *m; 1545{ 1546 struct m_tag *mtag; 1547 1548 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1549 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1550} 1551 1552void 1553ip6_delaux(m) 1554 struct mbuf *m; 1555{ 1556 struct m_tag *mtag; 1557 1558 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1559 if (mtag) 1560 m_tag_delete(m, mtag); 1561} 1562 1563/* 1564 * System control for IP6 1565 */ 1566 1567u_char inet6ctlerrmap[PRC_NCMDS] = { 1568 0, 0, 0, 0, 1569 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1570 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1571 EMSGSIZE, EHOSTUNREACH, 0, 0, 1572 0, 0, 0, 0, 1573 ENOPROTOOPT 1574}; 1575