ip6_input.c revision 121674
1/* $FreeBSD: head/sys/netinet6/ip6_input.c 121674 2003-10-29 12:52:28Z 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 nd6_init(); 202 frag6_init(); 203#ifndef RANDOM_IP_ID 204 ip6_flow_seq = arc4random(); 205#endif 206 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 207} 208 209static void 210ip6_init2(dummy) 211 void *dummy; 212{ 213 214 /* nd6_timer_init */ 215 callout_init(&nd6_timer_ch, 0); 216 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 217 218 /* router renumbering prefix list maintenance */ 219 callout_init(&in6_rr_timer_ch, 0); 220 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 221 222 /* timer for regeneranation of temporary addresses randomize ID */ 223 callout_reset(&in6_tmpaddrtimer_ch, 224 (ip6_temp_preferred_lifetime - ip6_desync_factor - 225 ip6_temp_regen_advance) * hz, 226 in6_tmpaddrtimer, NULL); 227} 228 229/* cheat */ 230/* This must be after route_init(), which is now SI_ORDER_THIRD */ 231SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 232 233extern struct route_in6 ip6_forward_rt; 234 235void 236ip6_input(m) 237 struct mbuf *m; 238{ 239 struct ip6_hdr *ip6; 240 int off = sizeof(struct ip6_hdr), nest; 241 u_int32_t plen; 242 u_int32_t rtalert = ~0; 243 int nxt, ours = 0; 244 struct ifnet *deliverifp = NULL; 245#ifdef PFIL_HOOKS 246 struct in6_addr odst; 247#endif 248 int srcrt = 0; 249 250#ifdef IPSEC 251 /* 252 * should the inner packet be considered authentic? 253 * see comment in ah4_input(). 254 */ 255 if (m) { 256 m->m_flags &= ~M_AUTHIPHDR; 257 m->m_flags &= ~M_AUTHIPDGM; 258 } 259#endif 260 261 /* 262 * make sure we don't have onion peering information into m_tag. 263 */ 264 ip6_delaux(m); 265 266 /* 267 * mbuf statistics 268 */ 269 if (m->m_flags & M_EXT) { 270 if (m->m_next) 271 ip6stat.ip6s_mext2m++; 272 else 273 ip6stat.ip6s_mext1++; 274 } else { 275#define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 276 if (m->m_next) { 277 if (m->m_flags & M_LOOP) { 278 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 279 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 280 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 281 else 282 ip6stat.ip6s_m2m[0]++; 283 } else 284 ip6stat.ip6s_m1++; 285#undef M2MMAX 286 } 287 288 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 289 ip6stat.ip6s_total++; 290 291#ifndef PULLDOWN_TEST 292 /* 293 * L2 bridge code and some other code can return mbuf chain 294 * that does not conform to KAME requirement. too bad. 295 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 296 */ 297 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 298 struct mbuf *n; 299 300 MGETHDR(n, M_DONTWAIT, MT_HEADER); 301 if (n) 302 M_MOVE_PKTHDR(n, m); 303 if (n && n->m_pkthdr.len > MHLEN) { 304 MCLGET(n, M_DONTWAIT); 305 if ((n->m_flags & M_EXT) == 0) { 306 m_freem(n); 307 n = NULL; 308 } 309 } 310 if (n == NULL) { 311 m_freem(m); 312 return; /* ENOBUFS */ 313 } 314 315 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 316 n->m_len = n->m_pkthdr.len; 317 m_freem(m); 318 m = n; 319 } 320 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 321#endif 322 323 if (m->m_len < sizeof(struct ip6_hdr)) { 324 struct ifnet *inifp; 325 inifp = m->m_pkthdr.rcvif; 326 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 327 ip6stat.ip6s_toosmall++; 328 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 329 return; 330 } 331 } 332 333 ip6 = mtod(m, struct ip6_hdr *); 334 335 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 336 ip6stat.ip6s_badvers++; 337 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 338 goto bad; 339 } 340 341#ifdef PFIL_HOOKS 342 /* 343 * Run through list of hooks for input packets. 344 * 345 * NB: Beware of the destination address changing 346 * (e.g. by NAT rewriting). When this happens, 347 * tell ip6_forward to do the right thing. 348 */ 349 odst = ip6->ip6_dst; 350 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 351 return; 352 if (m == NULL) /* consumed by filter */ 353 return; 354 ip6 = mtod(m, struct ip6_hdr *); 355 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 356#endif /* PFIL_HOOKS */ 357 358 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 359 360 /* 361 * Check with the firewall... 362 */ 363 if (ip6_fw_enable && ip6_fw_chk_ptr) { 364 u_short port = 0; 365 /* If ipfw says divert, we have to just drop packet */ 366 /* use port as a dummy argument */ 367 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 368 m_freem(m); 369 m = NULL; 370 } 371 if (!m) 372 return; 373 } 374 375 /* 376 * Check against address spoofing/corruption. 377 */ 378 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 379 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 380 /* 381 * XXX: "badscope" is not very suitable for a multicast source. 382 */ 383 ip6stat.ip6s_badscope++; 384 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 385 goto bad; 386 } 387 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 388 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 389 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 390 ip6stat.ip6s_badscope++; 391 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 392 goto bad; 393 } 394 395 /* 396 * The following check is not documented in specs. A malicious 397 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 398 * and bypass security checks (act as if it was from 127.0.0.1 by using 399 * IPv6 src ::ffff:127.0.0.1). Be cautious. 400 * 401 * This check chokes if we are in an SIIT cloud. As none of BSDs 402 * support IPv4-less kernel compilation, we cannot support SIIT 403 * environment at all. So, it makes more sense for us to reject any 404 * malicious packets for non-SIIT environment, than try to do a 405 * partial support for SIIT environment. 406 */ 407 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 408 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 409 ip6stat.ip6s_badscope++; 410 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 411 goto bad; 412 } 413#if 0 414 /* 415 * Reject packets with IPv4 compatible addresses (auto tunnel). 416 * 417 * The code forbids auto tunnel relay case in RFC1933 (the check is 418 * stronger than RFC1933). We may want to re-enable it if mech-xx 419 * is revised to forbid relaying case. 420 */ 421 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 422 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 423 ip6stat.ip6s_badscope++; 424 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 425 goto bad; 426 } 427#endif 428 429 /* drop packets if interface ID portion is already filled */ 430 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 431 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 432 ip6->ip6_src.s6_addr16[1]) { 433 ip6stat.ip6s_badscope++; 434 goto bad; 435 } 436 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) || 437 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) && 438 ip6->ip6_dst.s6_addr16[1]) { 439 ip6stat.ip6s_badscope++; 440 goto bad; 441 } 442 } 443 444 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 445 ip6->ip6_src.s6_addr16[1] 446 = htons(m->m_pkthdr.rcvif->if_index); 447 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 448 ip6->ip6_dst.s6_addr16[1] 449 = htons(m->m_pkthdr.rcvif->if_index); 450 451 /* 452 * Multicast check 453 */ 454 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 455 struct in6_multi *in6m = 0; 456 457 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 458 /* 459 * See if we belong to the destination multicast group on the 460 * arrival interface. 461 */ 462 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 463 if (in6m) 464 ours = 1; 465 else if (!ip6_mrouter) { 466 ip6stat.ip6s_notmember++; 467 ip6stat.ip6s_cantforward++; 468 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 469 goto bad; 470 } 471 deliverifp = m->m_pkthdr.rcvif; 472 goto hbhcheck; 473 } 474 475 /* 476 * Unicast check 477 */ 478 if (ip6_forward_rt.ro_rt != NULL && 479 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 480 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 481 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 482 ip6stat.ip6s_forward_cachehit++; 483 else { 484 struct sockaddr_in6 *dst6; 485 486 if (ip6_forward_rt.ro_rt) { 487 /* route is down or destination is different */ 488 ip6stat.ip6s_forward_cachemiss++; 489 RTFREE(ip6_forward_rt.ro_rt); 490 ip6_forward_rt.ro_rt = 0; 491 } 492 493 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 494 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 495 dst6->sin6_len = sizeof(struct sockaddr_in6); 496 dst6->sin6_family = AF_INET6; 497 dst6->sin6_addr = ip6->ip6_dst; 498 499 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 500 } 501 502#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 503 504 /* 505 * Accept the packet if the forwarding interface to the destination 506 * according to the routing table is the loopback interface, 507 * unless the associated route has a gateway. 508 * Note that this approach causes to accept a packet if there is a 509 * route to the loopback interface for the destination of the packet. 510 * But we think it's even useful in some situations, e.g. when using 511 * a special daemon which wants to intercept the packet. 512 * 513 * XXX: some OSes automatically make a cloned route for the destination 514 * of an outgoing packet. If the outgoing interface of the packet 515 * is a loopback one, the kernel would consider the packet to be 516 * accepted, even if we have no such address assinged on the interface. 517 * We check the cloned flag of the route entry to reject such cases, 518 * assuming that route entries for our own addresses are not made by 519 * cloning (it should be true because in6_addloop explicitly installs 520 * the host route). However, we might have to do an explicit check 521 * while it would be less efficient. Or, should we rather install a 522 * reject route for such a case? 523 */ 524 if (ip6_forward_rt.ro_rt && 525 (ip6_forward_rt.ro_rt->rt_flags & 526 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 527#ifdef RTF_WASCLONED 528 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 529#endif 530#ifdef RTF_CLONED 531 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 532#endif 533#if 0 534 /* 535 * The check below is redundant since the comparison of 536 * the destination and the key of the rtentry has 537 * already done through looking up the routing table. 538 */ 539 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 540 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 541#endif 542 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 543 struct in6_ifaddr *ia6 = 544 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 545 546 /* 547 * record address information into m_tag. 548 */ 549 (void)ip6_setdstifaddr(m, ia6); 550 551 /* 552 * packets to a tentative, duplicated, or somehow invalid 553 * address must not be accepted. 554 */ 555 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 556 /* this address is ready */ 557 ours = 1; 558 deliverifp = ia6->ia_ifp; /* correct? */ 559 /* Count the packet in the ip address stats */ 560 ia6->ia_ifa.if_ipackets++; 561 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 562 goto hbhcheck; 563 } else { 564 /* address is not ready, so discard the packet. */ 565 nd6log((LOG_INFO, 566 "ip6_input: packet to an unready address %s->%s\n", 567 ip6_sprintf(&ip6->ip6_src), 568 ip6_sprintf(&ip6->ip6_dst))); 569 570 goto bad; 571 } 572 } 573 574 /* 575 * FAITH (Firewall Aided Internet Translator) 576 */ 577 if (ip6_keepfaith) { 578 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 579 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 580 /* XXX do we need more sanity checks? */ 581 ours = 1; 582 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 583 goto hbhcheck; 584 } 585 } 586 587 /* 588 * Now there is no reason to process the packet if it's not our own 589 * and we're not a router. 590 */ 591 if (!ip6_forwarding) { 592 ip6stat.ip6s_cantforward++; 593 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 594 goto bad; 595 } 596 597 hbhcheck: 598 /* 599 * record address information into m_tag, if we don't have one yet. 600 * note that we are unable to record it, if the address is not listed 601 * as our interface address (e.g. multicast addresses, addresses 602 * within FAITH prefixes and such). 603 */ 604 if (deliverifp && !ip6_getdstifaddr(m)) { 605 struct in6_ifaddr *ia6; 606 607 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 608 if (ia6) { 609 if (!ip6_setdstifaddr(m, ia6)) { 610 /* 611 * XXX maybe we should drop the packet here, 612 * as we could not provide enough information 613 * to the upper layers. 614 */ 615 } 616 } 617 } 618 619 /* 620 * Process Hop-by-Hop options header if it's contained. 621 * m may be modified in ip6_hopopts_input(). 622 * If a JumboPayload option is included, plen will also be modified. 623 */ 624 plen = (u_int32_t)ntohs(ip6->ip6_plen); 625 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 626 struct ip6_hbh *hbh; 627 628 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 629#if 0 /*touches NULL pointer*/ 630 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 631#endif 632 return; /* m have already been freed */ 633 } 634 635 /* adjust pointer */ 636 ip6 = mtod(m, struct ip6_hdr *); 637 638 /* 639 * if the payload length field is 0 and the next header field 640 * indicates Hop-by-Hop Options header, then a Jumbo Payload 641 * option MUST be included. 642 */ 643 if (ip6->ip6_plen == 0 && plen == 0) { 644 /* 645 * Note that if a valid jumbo payload option is 646 * contained, ip6_hopopts_input() must set a valid 647 * (non-zero) payload length to the variable plen. 648 */ 649 ip6stat.ip6s_badoptions++; 650 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 651 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 652 icmp6_error(m, ICMP6_PARAM_PROB, 653 ICMP6_PARAMPROB_HEADER, 654 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 655 return; 656 } 657#ifndef PULLDOWN_TEST 658 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 659 hbh = (struct ip6_hbh *)(ip6 + 1); 660#else 661 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 662 sizeof(struct ip6_hbh)); 663 if (hbh == NULL) { 664 ip6stat.ip6s_tooshort++; 665 return; 666 } 667#endif 668 nxt = hbh->ip6h_nxt; 669 670 /* 671 * accept the packet if a router alert option is included 672 * and we act as an IPv6 router. 673 */ 674 if (rtalert != ~0 && ip6_forwarding) 675 ours = 1; 676 } else 677 nxt = ip6->ip6_nxt; 678 679 /* 680 * Check that the amount of data in the buffers 681 * is as at least much as the IPv6 header would have us expect. 682 * Trim mbufs if longer than we expect. 683 * Drop packet if shorter than we expect. 684 */ 685 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 686 ip6stat.ip6s_tooshort++; 687 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 688 goto bad; 689 } 690 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 691 if (m->m_len == m->m_pkthdr.len) { 692 m->m_len = sizeof(struct ip6_hdr) + plen; 693 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 694 } else 695 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 696 } 697 698 /* 699 * Forward if desirable. 700 */ 701 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 702 /* 703 * If we are acting as a multicast router, all 704 * incoming multicast packets are passed to the 705 * kernel-level multicast forwarding function. 706 * The packet is returned (relatively) intact; if 707 * ip6_mforward() returns a non-zero value, the packet 708 * must be discarded, else it may be accepted below. 709 */ 710 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 711 ip6stat.ip6s_cantforward++; 712 m_freem(m); 713 return; 714 } 715 if (!ours) { 716 m_freem(m); 717 return; 718 } 719 } else if (!ours) { 720 ip6_forward(m, srcrt); 721 return; 722 } 723 724 ip6 = mtod(m, struct ip6_hdr *); 725 726 /* 727 * Malicious party may be able to use IPv4 mapped addr to confuse 728 * tcp/udp stack and bypass security checks (act as if it was from 729 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 730 * 731 * For SIIT end node behavior, you may want to disable the check. 732 * However, you will become vulnerable to attacks using IPv4 mapped 733 * source. 734 */ 735 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 736 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 737 ip6stat.ip6s_badscope++; 738 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 739 goto bad; 740 } 741 742 /* 743 * Tell launch routine the next header 744 */ 745 ip6stat.ip6s_delivered++; 746 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 747 nest = 0; 748 749 while (nxt != IPPROTO_DONE) { 750 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 751 ip6stat.ip6s_toomanyhdr++; 752 goto bad; 753 } 754 755 /* 756 * protection against faulty packet - there should be 757 * more sanity checks in header chain processing. 758 */ 759 if (m->m_pkthdr.len < off) { 760 ip6stat.ip6s_tooshort++; 761 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 762 goto bad; 763 } 764 765#ifdef IPSEC 766 /* 767 * enforce IPsec policy checking if we are seeing last header. 768 * note that we do not visit this with protocols with pcb layer 769 * code - like udp/tcp/raw ip. 770 */ 771 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 772 ipsec6_in_reject(m, NULL)) { 773 ipsec6stat.in_polvio++; 774 goto bad; 775 } 776#endif 777 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 778 } 779 return; 780 bad: 781 m_freem(m); 782} 783 784/* 785 * set/grab in6_ifaddr correspond to IPv6 destination address. 786 * XXX backward compatibility wrapper 787 */ 788static struct ip6aux * 789ip6_setdstifaddr(m, ia6) 790 struct mbuf *m; 791 struct in6_ifaddr *ia6; 792{ 793 struct ip6aux *ip6a; 794 795 ip6a = ip6_addaux(m); 796 if (ip6a) 797 ip6a->ip6a_dstia6 = ia6; 798 return ip6a; /* NULL if failed to set */ 799} 800 801struct in6_ifaddr * 802ip6_getdstifaddr(m) 803 struct mbuf *m; 804{ 805 struct ip6aux *ip6a; 806 807 ip6a = ip6_findaux(m); 808 if (ip6a) 809 return ip6a->ip6a_dstia6; 810 else 811 return NULL; 812} 813 814/* 815 * Hop-by-Hop options header processing. If a valid jumbo payload option is 816 * included, the real payload length will be stored in plenp. 817 */ 818static int 819ip6_hopopts_input(plenp, rtalertp, mp, offp) 820 u_int32_t *plenp; 821 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 822 struct mbuf **mp; 823 int *offp; 824{ 825 struct mbuf *m = *mp; 826 int off = *offp, hbhlen; 827 struct ip6_hbh *hbh; 828 u_int8_t *opt; 829 830 /* validation of the length of the header */ 831#ifndef PULLDOWN_TEST 832 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 833 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 834 hbhlen = (hbh->ip6h_len + 1) << 3; 835 836 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 837 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 838#else 839 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 840 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 841 if (hbh == NULL) { 842 ip6stat.ip6s_tooshort++; 843 return -1; 844 } 845 hbhlen = (hbh->ip6h_len + 1) << 3; 846 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 847 hbhlen); 848 if (hbh == NULL) { 849 ip6stat.ip6s_tooshort++; 850 return -1; 851 } 852#endif 853 off += hbhlen; 854 hbhlen -= sizeof(struct ip6_hbh); 855 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 856 857 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 858 hbhlen, rtalertp, plenp) < 0) 859 return (-1); 860 861 *offp = off; 862 *mp = m; 863 return (0); 864} 865 866/* 867 * Search header for all Hop-by-hop options and process each option. 868 * This function is separate from ip6_hopopts_input() in order to 869 * handle a case where the sending node itself process its hop-by-hop 870 * options header. In such a case, the function is called from ip6_output(). 871 * 872 * The function assumes that hbh header is located right after the IPv6 header 873 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 874 * opthead + hbhlen is located in continuous memory region. 875 */ 876int 877ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 878 struct mbuf *m; 879 u_int8_t *opthead; 880 int hbhlen; 881 u_int32_t *rtalertp; 882 u_int32_t *plenp; 883{ 884 struct ip6_hdr *ip6; 885 int optlen = 0; 886 u_int8_t *opt = opthead; 887 u_int16_t rtalert_val; 888 u_int32_t jumboplen; 889 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 890 891 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 892 switch (*opt) { 893 case IP6OPT_PAD1: 894 optlen = 1; 895 break; 896 case IP6OPT_PADN: 897 if (hbhlen < IP6OPT_MINLEN) { 898 ip6stat.ip6s_toosmall++; 899 goto bad; 900 } 901 optlen = *(opt + 1) + 2; 902 break; 903 case IP6OPT_ROUTER_ALERT: 904 /* XXX may need check for alignment */ 905 if (hbhlen < IP6OPT_RTALERT_LEN) { 906 ip6stat.ip6s_toosmall++; 907 goto bad; 908 } 909 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 910 /* XXX stat */ 911 icmp6_error(m, ICMP6_PARAM_PROB, 912 ICMP6_PARAMPROB_HEADER, 913 erroff + opt + 1 - opthead); 914 return (-1); 915 } 916 optlen = IP6OPT_RTALERT_LEN; 917 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 918 *rtalertp = ntohs(rtalert_val); 919 break; 920 case IP6OPT_JUMBO: 921 /* XXX may need check for alignment */ 922 if (hbhlen < IP6OPT_JUMBO_LEN) { 923 ip6stat.ip6s_toosmall++; 924 goto bad; 925 } 926 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 927 /* XXX stat */ 928 icmp6_error(m, ICMP6_PARAM_PROB, 929 ICMP6_PARAMPROB_HEADER, 930 erroff + opt + 1 - opthead); 931 return (-1); 932 } 933 optlen = IP6OPT_JUMBO_LEN; 934 935 /* 936 * IPv6 packets that have non 0 payload length 937 * must not contain a jumbo payload option. 938 */ 939 ip6 = mtod(m, struct ip6_hdr *); 940 if (ip6->ip6_plen) { 941 ip6stat.ip6s_badoptions++; 942 icmp6_error(m, ICMP6_PARAM_PROB, 943 ICMP6_PARAMPROB_HEADER, 944 erroff + opt - opthead); 945 return (-1); 946 } 947 948 /* 949 * We may see jumbolen in unaligned location, so 950 * we'd need to perform bcopy(). 951 */ 952 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 953 jumboplen = (u_int32_t)htonl(jumboplen); 954 955#if 1 956 /* 957 * if there are multiple jumbo payload options, 958 * *plenp will be non-zero and the packet will be 959 * rejected. 960 * the behavior may need some debate in ipngwg - 961 * multiple options does not make sense, however, 962 * there's no explicit mention in specification. 963 */ 964 if (*plenp != 0) { 965 ip6stat.ip6s_badoptions++; 966 icmp6_error(m, ICMP6_PARAM_PROB, 967 ICMP6_PARAMPROB_HEADER, 968 erroff + opt + 2 - opthead); 969 return (-1); 970 } 971#endif 972 973 /* 974 * jumbo payload length must be larger than 65535. 975 */ 976 if (jumboplen <= IPV6_MAXPACKET) { 977 ip6stat.ip6s_badoptions++; 978 icmp6_error(m, ICMP6_PARAM_PROB, 979 ICMP6_PARAMPROB_HEADER, 980 erroff + opt + 2 - opthead); 981 return (-1); 982 } 983 *plenp = jumboplen; 984 985 break; 986 default: /* unknown option */ 987 if (hbhlen < IP6OPT_MINLEN) { 988 ip6stat.ip6s_toosmall++; 989 goto bad; 990 } 991 optlen = ip6_unknown_opt(opt, m, 992 erroff + opt - opthead); 993 if (optlen == -1) 994 return (-1); 995 optlen += 2; 996 break; 997 } 998 } 999 1000 return (0); 1001 1002 bad: 1003 m_freem(m); 1004 return (-1); 1005} 1006 1007/* 1008 * Unknown option processing. 1009 * The third argument `off' is the offset from the IPv6 header to the option, 1010 * which is necessary if the IPv6 header the and option header and IPv6 header 1011 * is not continuous in order to return an ICMPv6 error. 1012 */ 1013int 1014ip6_unknown_opt(optp, m, off) 1015 u_int8_t *optp; 1016 struct mbuf *m; 1017 int off; 1018{ 1019 struct ip6_hdr *ip6; 1020 1021 switch (IP6OPT_TYPE(*optp)) { 1022 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1023 return ((int)*(optp + 1)); 1024 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1025 m_freem(m); 1026 return (-1); 1027 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1028 ip6stat.ip6s_badoptions++; 1029 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1030 return (-1); 1031 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1032 ip6stat.ip6s_badoptions++; 1033 ip6 = mtod(m, struct ip6_hdr *); 1034 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1035 (m->m_flags & (M_BCAST|M_MCAST))) 1036 m_freem(m); 1037 else 1038 icmp6_error(m, ICMP6_PARAM_PROB, 1039 ICMP6_PARAMPROB_OPTION, off); 1040 return (-1); 1041 } 1042 1043 m_freem(m); /* XXX: NOTREACHED */ 1044 return (-1); 1045} 1046 1047/* 1048 * Create the "control" list for this pcb. 1049 * The function will not modify mbuf chain at all. 1050 * 1051 * with KAME mbuf chain restriction: 1052 * The routine will be called from upper layer handlers like tcp6_input(). 1053 * Thus the routine assumes that the caller (tcp6_input) have already 1054 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1055 * very first mbuf on the mbuf chain. 1056 */ 1057void 1058ip6_savecontrol(in6p, m, mp) 1059 struct inpcb *in6p; 1060 struct mbuf *m, **mp; 1061{ 1062#define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1063 struct thread *td = curthread; /* XXX */ 1064 int privileged = 0; 1065 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1066 1067 if (td && !suser(td)) 1068 privileged++; 1069 1070#ifdef SO_TIMESTAMP 1071 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1072 struct timeval tv; 1073 1074 microtime(&tv); 1075 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1076 SCM_TIMESTAMP, SOL_SOCKET); 1077 if (*mp) 1078 mp = &(*mp)->m_next; 1079 } 1080#endif 1081 1082 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1083 return; 1084 1085 /* RFC 2292 sec. 5 */ 1086 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1087 struct in6_pktinfo pi6; 1088 1089 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1090 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1091 pi6.ipi6_ifindex = 1092 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1093 1094 *mp = sbcreatecontrol((caddr_t) &pi6, 1095 sizeof(struct in6_pktinfo), 1096 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1097 if (*mp) 1098 mp = &(*mp)->m_next; 1099 } 1100 1101 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1102 int hlim = ip6->ip6_hlim & 0xff; 1103 1104 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1105 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1106 if (*mp) 1107 mp = &(*mp)->m_next; 1108 } 1109 1110 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1111 u_int32_t flowinfo; 1112 int tclass; 1113 1114 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1115 flowinfo >>= 20; 1116 1117 tclass = flowinfo & 0xff; 1118 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1119 IPV6_TCLASS, IPPROTO_IPV6); 1120 if (*mp) 1121 mp = &(*mp)->m_next; 1122 } 1123 1124 /* 1125 * IPV6_HOPOPTS socket option. We require super-user privilege 1126 * for the option, but it might be too strict, since there might 1127 * be some hop-by-hop options which can be returned to normal user. 1128 * See RFC 2292 section 6. 1129 */ 1130 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1131#ifdef DIAGNOSTIC 1132 if (!privileged) 1133 panic("IN6P_HOPOPTS is set for unprivileged socket"); 1134#endif 1135 /* 1136 * Check if a hop-by-hop options header is contatined in the 1137 * received packet, and if so, store the options as ancillary 1138 * data. Note that a hop-by-hop options header must be 1139 * just after the IPv6 header, which is assured through the 1140 * IPv6 input processing. 1141 */ 1142 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1143 struct ip6_hbh *hbh; 1144 int hbhlen = 0; 1145#ifdef PULLDOWN_TEST 1146 struct mbuf *ext; 1147#endif 1148 1149#ifndef PULLDOWN_TEST 1150 hbh = (struct ip6_hbh *)(ip6 + 1); 1151 hbhlen = (hbh->ip6h_len + 1) << 3; 1152#else 1153 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1154 ip6->ip6_nxt); 1155 if (ext == NULL) { 1156 ip6stat.ip6s_tooshort++; 1157 return; 1158 } 1159 hbh = mtod(ext, struct ip6_hbh *); 1160 hbhlen = (hbh->ip6h_len + 1) << 3; 1161 if (hbhlen != ext->m_len) { 1162 m_freem(ext); 1163 ip6stat.ip6s_tooshort++; 1164 return; 1165 } 1166#endif 1167 1168 /* 1169 * XXX: We copy the whole header even if a 1170 * jumbo payload option is included, the option which 1171 * is to be removed before returning according to 1172 * RFC2292. 1173 * Note: this constraint is removed in 2292bis. 1174 */ 1175 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1176 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1177 IPPROTO_IPV6); 1178 if (*mp) 1179 mp = &(*mp)->m_next; 1180#ifdef PULLDOWN_TEST 1181 m_freem(ext); 1182#endif 1183 } 1184 } 1185 1186 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1187 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1188 1189 /* 1190 * Search for destination options headers or routing 1191 * header(s) through the header chain, and stores each 1192 * header as ancillary data. 1193 * Note that the order of the headers remains in 1194 * the chain of ancillary data. 1195 */ 1196 while (1) { /* is explicit loop prevention necessary? */ 1197 struct ip6_ext *ip6e = NULL; 1198 int elen; 1199#ifdef PULLDOWN_TEST 1200 struct mbuf *ext = NULL; 1201#endif 1202 1203 /* 1204 * if it is not an extension header, don't try to 1205 * pull it from the chain. 1206 */ 1207 switch (nxt) { 1208 case IPPROTO_DSTOPTS: 1209 case IPPROTO_ROUTING: 1210 case IPPROTO_HOPOPTS: 1211 case IPPROTO_AH: /* is it possible? */ 1212 break; 1213 default: 1214 goto loopend; 1215 } 1216 1217#ifndef PULLDOWN_TEST 1218 if (off + sizeof(*ip6e) > m->m_len) 1219 goto loopend; 1220 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1221 if (nxt == IPPROTO_AH) 1222 elen = (ip6e->ip6e_len + 2) << 2; 1223 else 1224 elen = (ip6e->ip6e_len + 1) << 3; 1225 if (off + elen > m->m_len) 1226 goto loopend; 1227#else 1228 ext = ip6_pullexthdr(m, off, nxt); 1229 if (ext == NULL) { 1230 ip6stat.ip6s_tooshort++; 1231 return; 1232 } 1233 ip6e = mtod(ext, struct ip6_ext *); 1234 if (nxt == IPPROTO_AH) 1235 elen = (ip6e->ip6e_len + 2) << 2; 1236 else 1237 elen = (ip6e->ip6e_len + 1) << 3; 1238 if (elen != ext->m_len) { 1239 m_freem(ext); 1240 ip6stat.ip6s_tooshort++; 1241 return; 1242 } 1243#endif 1244 1245 switch (nxt) { 1246 case IPPROTO_DSTOPTS: 1247 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1248 break; 1249 1250 /* 1251 * We also require super-user privilege for 1252 * the option. See comments on IN6_HOPOPTS. 1253 */ 1254 if (!privileged) 1255 break; 1256 1257 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1258 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1259 IPPROTO_IPV6); 1260 if (*mp) 1261 mp = &(*mp)->m_next; 1262 break; 1263 case IPPROTO_ROUTING: 1264 if (!in6p->in6p_flags & IN6P_RTHDR) 1265 break; 1266 1267 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1268 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1269 IPPROTO_IPV6); 1270 if (*mp) 1271 mp = &(*mp)->m_next; 1272 break; 1273 case IPPROTO_HOPOPTS: 1274 case IPPROTO_AH: /* is it possible? */ 1275 break; 1276 1277 default: 1278 /* 1279 * other cases have been filtered in the above. 1280 * none will visit this case. here we supply 1281 * the code just in case (nxt overwritten or 1282 * other cases). 1283 */ 1284#ifdef PULLDOWN_TEST 1285 m_freem(ext); 1286#endif 1287 goto loopend; 1288 1289 } 1290 1291 /* proceed with the next header. */ 1292 off += elen; 1293 nxt = ip6e->ip6e_nxt; 1294 ip6e = NULL; 1295#ifdef PULLDOWN_TEST 1296 m_freem(ext); 1297 ext = NULL; 1298#endif 1299 } 1300 loopend: 1301 ; 1302 } 1303 1304#undef IS2292 1305} 1306 1307#ifdef PULLDOWN_TEST 1308/* 1309 * pull single extension header from mbuf chain. returns single mbuf that 1310 * contains the result, or NULL on error. 1311 */ 1312static struct mbuf * 1313ip6_pullexthdr(m, off, nxt) 1314 struct mbuf *m; 1315 size_t off; 1316 int nxt; 1317{ 1318 struct ip6_ext ip6e; 1319 size_t elen; 1320 struct mbuf *n; 1321 1322#ifdef DIAGNOSTIC 1323 switch (nxt) { 1324 case IPPROTO_DSTOPTS: 1325 case IPPROTO_ROUTING: 1326 case IPPROTO_HOPOPTS: 1327 case IPPROTO_AH: /* is it possible? */ 1328 break; 1329 default: 1330 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1331 } 1332#endif 1333 1334 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1335 if (nxt == IPPROTO_AH) 1336 elen = (ip6e.ip6e_len + 2) << 2; 1337 else 1338 elen = (ip6e.ip6e_len + 1) << 3; 1339 1340 MGET(n, M_DONTWAIT, MT_DATA); 1341 if (n && elen >= MLEN) { 1342 MCLGET(n, M_DONTWAIT); 1343 if ((n->m_flags & M_EXT) == 0) { 1344 m_free(n); 1345 n = NULL; 1346 } 1347 } 1348 if (!n) 1349 return NULL; 1350 1351 n->m_len = 0; 1352 if (elen >= M_TRAILINGSPACE(n)) { 1353 m_free(n); 1354 return NULL; 1355 } 1356 1357 m_copydata(m, off, elen, mtod(n, caddr_t)); 1358 n->m_len = elen; 1359 return n; 1360} 1361#endif 1362 1363/* 1364 * Get pointer to the previous header followed by the header 1365 * currently processed. 1366 * XXX: This function supposes that 1367 * M includes all headers, 1368 * the next header field and the header length field of each header 1369 * are valid, and 1370 * the sum of each header length equals to OFF. 1371 * Because of these assumptions, this function must be called very 1372 * carefully. Moreover, it will not be used in the near future when 1373 * we develop `neater' mechanism to process extension headers. 1374 */ 1375char * 1376ip6_get_prevhdr(m, off) 1377 struct mbuf *m; 1378 int off; 1379{ 1380 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1381 1382 if (off == sizeof(struct ip6_hdr)) 1383 return (&ip6->ip6_nxt); 1384 else { 1385 int len, nxt; 1386 struct ip6_ext *ip6e = NULL; 1387 1388 nxt = ip6->ip6_nxt; 1389 len = sizeof(struct ip6_hdr); 1390 while (len < off) { 1391 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1392 1393 switch (nxt) { 1394 case IPPROTO_FRAGMENT: 1395 len += sizeof(struct ip6_frag); 1396 break; 1397 case IPPROTO_AH: 1398 len += (ip6e->ip6e_len + 2) << 2; 1399 break; 1400 default: 1401 len += (ip6e->ip6e_len + 1) << 3; 1402 break; 1403 } 1404 nxt = ip6e->ip6e_nxt; 1405 } 1406 if (ip6e) 1407 return (&ip6e->ip6e_nxt); 1408 else 1409 return NULL; 1410 } 1411} 1412 1413/* 1414 * get next header offset. m will be retained. 1415 */ 1416int 1417ip6_nexthdr(m, off, proto, nxtp) 1418 struct mbuf *m; 1419 int off; 1420 int proto; 1421 int *nxtp; 1422{ 1423 struct ip6_hdr ip6; 1424 struct ip6_ext ip6e; 1425 struct ip6_frag fh; 1426 1427 /* just in case */ 1428 if (m == NULL) 1429 panic("ip6_nexthdr: m == NULL"); 1430 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1431 return -1; 1432 1433 switch (proto) { 1434 case IPPROTO_IPV6: 1435 if (m->m_pkthdr.len < off + sizeof(ip6)) 1436 return -1; 1437 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1438 if (nxtp) 1439 *nxtp = ip6.ip6_nxt; 1440 off += sizeof(ip6); 1441 return off; 1442 1443 case IPPROTO_FRAGMENT: 1444 /* 1445 * terminate parsing if it is not the first fragment, 1446 * it does not make sense to parse through it. 1447 */ 1448 if (m->m_pkthdr.len < off + sizeof(fh)) 1449 return -1; 1450 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1451 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1452 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1453 return -1; 1454 if (nxtp) 1455 *nxtp = fh.ip6f_nxt; 1456 off += sizeof(struct ip6_frag); 1457 return off; 1458 1459 case IPPROTO_AH: 1460 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1461 return -1; 1462 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1463 if (nxtp) 1464 *nxtp = ip6e.ip6e_nxt; 1465 off += (ip6e.ip6e_len + 2) << 2; 1466 return off; 1467 1468 case IPPROTO_HOPOPTS: 1469 case IPPROTO_ROUTING: 1470 case IPPROTO_DSTOPTS: 1471 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1472 return -1; 1473 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1474 if (nxtp) 1475 *nxtp = ip6e.ip6e_nxt; 1476 off += (ip6e.ip6e_len + 1) << 3; 1477 return off; 1478 1479 case IPPROTO_NONE: 1480 case IPPROTO_ESP: 1481 case IPPROTO_IPCOMP: 1482 /* give up */ 1483 return -1; 1484 1485 default: 1486 return -1; 1487 } 1488 1489 return -1; 1490} 1491 1492/* 1493 * get offset for the last header in the chain. m will be kept untainted. 1494 */ 1495int 1496ip6_lasthdr(m, off, proto, nxtp) 1497 struct mbuf *m; 1498 int off; 1499 int proto; 1500 int *nxtp; 1501{ 1502 int newoff; 1503 int nxt; 1504 1505 if (!nxtp) { 1506 nxt = -1; 1507 nxtp = &nxt; 1508 } 1509 while (1) { 1510 newoff = ip6_nexthdr(m, off, proto, nxtp); 1511 if (newoff < 0) 1512 return off; 1513 else if (newoff < off) 1514 return -1; /* invalid */ 1515 else if (newoff == off) 1516 return newoff; 1517 1518 off = newoff; 1519 proto = *nxtp; 1520 } 1521} 1522 1523struct ip6aux * 1524ip6_addaux(m) 1525 struct mbuf *m; 1526{ 1527 struct m_tag *mtag; 1528 1529 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1530 if (!mtag) { 1531 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1532 M_NOWAIT); 1533 if (mtag) { 1534 m_tag_prepend(m, mtag); 1535 bzero(mtag + 1, sizeof(struct ip6aux)); 1536 } 1537 } 1538 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1539} 1540 1541struct ip6aux * 1542ip6_findaux(m) 1543 struct mbuf *m; 1544{ 1545 struct m_tag *mtag; 1546 1547 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1548 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1549} 1550 1551void 1552ip6_delaux(m) 1553 struct mbuf *m; 1554{ 1555 struct m_tag *mtag; 1556 1557 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1558 if (mtag) 1559 m_tag_delete(m, mtag); 1560} 1561 1562/* 1563 * System control for IP6 1564 */ 1565 1566u_char inet6ctlerrmap[PRC_NCMDS] = { 1567 0, 0, 0, 0, 1568 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1569 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1570 EMSGSIZE, EHOSTUNREACH, 0, 0, 1571 0, 0, 0, 0, 1572 ENOPROTOOPT 1573}; 1574