ip6_input.c revision 130416
1/* $FreeBSD: head/sys/netinet6/ip6_input.c 130416 2004-06-13 17:29:10Z mlaier $ */ 2/* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 3 4/* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33/* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 4. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 62 */ 63 64#include "opt_ip6fw.h" 65#include "opt_inet.h" 66#include "opt_inet6.h" 67#include "opt_ipsec.h" 68#include "opt_pfil_hooks.h" 69#include "opt_random_ip_id.h" 70 71#include <sys/param.h> 72#include <sys/systm.h> 73#include <sys/malloc.h> 74#include <sys/mbuf.h> 75#include <sys/proc.h> 76#include <sys/domain.h> 77#include <sys/protosw.h> 78#include <sys/socket.h> 79#include <sys/socketvar.h> 80#include <sys/errno.h> 81#include <sys/time.h> 82#include <sys/kernel.h> 83#include <sys/syslog.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#ifdef PFIL_HOOKS 91#include <net/pfil.h> 92#endif 93 94#include <netinet/in.h> 95#include <netinet/in_systm.h> 96#ifdef INET 97#include <netinet/ip.h> 98#include <netinet/ip_icmp.h> 99#endif /* INET */ 100#include <netinet/ip6.h> 101#include <netinet6/in6_var.h> 102#include <netinet6/ip6_var.h> 103#include <netinet/in_pcb.h> 104#include <netinet/icmp6.h> 105#include <netinet6/scope6_var.h> 106#include <netinet6/in6_ifattach.h> 107#include <netinet6/nd6.h> 108#include <netinet6/in6_prefix.h> 109 110#ifdef IPSEC 111#include <netinet6/ipsec.h> 112#ifdef INET6 113#include <netinet6/ipsec6.h> 114#endif 115#endif 116 117#ifdef FAST_IPSEC 118#include <netipsec/ipsec.h> 119#include <netipsec/ipsec6.h> 120#define IPSEC 121#endif /* FAST_IPSEC */ 122 123#include <netinet6/ip6_fw.h> 124 125#include <netinet6/ip6protosw.h> 126 127#include <net/net_osdep.h> 128 129extern struct domain inet6domain; 130 131u_char ip6_protox[IPPROTO_MAX]; 132static struct ifqueue ip6intrq; 133static int ip6qmaxlen = IFQ_MAXLEN; 134struct in6_ifaddr *in6_ifaddr; 135 136extern struct callout in6_tmpaddrtimer_ch; 137 138int ip6_forward_srcrt; /* XXX */ 139int ip6_sourcecheck; /* XXX */ 140int ip6_sourcecheck_interval; /* XXX */ 141 142int ip6_ours_check_algorithm; 143 144#ifdef PFIL_HOOKS 145struct pfil_head inet6_pfil_hook; 146#endif 147 148/* firewall hooks */ 149ip6_fw_chk_t *ip6_fw_chk_ptr; 150ip6_fw_ctl_t *ip6_fw_ctl_ptr; 151int ip6_fw_enable = 1; 152 153struct ip6stat ip6stat; 154 155static void ip6_init2 __P((void *)); 156static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 157static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 158#ifdef PULLDOWN_TEST 159static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 160#endif 161 162/* 163 * IP6 initialization: fill in IP6 protocol switch table. 164 * All protocols not implemented in kernel go to raw IP6 protocol handler. 165 */ 166void 167ip6_init() 168{ 169 struct ip6protosw *pr; 170 int i; 171 172#ifdef DIAGNOSTIC 173 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 174 panic("sizeof(protosw) != sizeof(ip6protosw)"); 175#endif 176 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 177 if (pr == 0) 178 panic("ip6_init"); 179 for (i = 0; i < IPPROTO_MAX; i++) 180 ip6_protox[i] = pr - inet6sw; 181 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 182 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 183 if (pr->pr_domain->dom_family == PF_INET6 && 184 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 185 ip6_protox[pr->pr_protocol] = pr - inet6sw; 186#ifdef PFIL_HOOKS 187 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 188 inet6_pfil_hook.ph_af = AF_INET6; 189 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 190 printf("%s: WARNING: unable to register pfil hook, " 191 "error %d\n", __func__, i); 192#endif /* PFIL_HOOKS */ 193 ip6intrq.ifq_maxlen = ip6qmaxlen; 194 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 195 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 196 scope6_init(); 197 addrsel_policy_init(); 198 nd6_init(); 199 frag6_init(); 200#ifndef RANDOM_IP_ID 201 ip6_flow_seq = arc4random(); 202#endif 203 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 204} 205 206static void 207ip6_init2(dummy) 208 void *dummy; 209{ 210 211 /* nd6_timer_init */ 212 callout_init(&nd6_timer_ch, 0); 213 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 214 215 /* router renumbering prefix list maintenance */ 216 callout_init(&in6_rr_timer_ch, 0); 217 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 218 219 /* timer for regeneranation of temporary addresses randomize ID */ 220 callout_init(&in6_tmpaddrtimer_ch, 0); 221 callout_reset(&in6_tmpaddrtimer_ch, 222 (ip6_temp_preferred_lifetime - ip6_desync_factor - 223 ip6_temp_regen_advance) * hz, 224 in6_tmpaddrtimer, NULL); 225} 226 227/* cheat */ 228/* This must be after route_init(), which is now SI_ORDER_THIRD */ 229SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 230 231extern struct route_in6 ip6_forward_rt; 232 233void 234ip6_input(m) 235 struct mbuf *m; 236{ 237 struct ip6_hdr *ip6; 238 int off = sizeof(struct ip6_hdr), nest; 239 u_int32_t plen; 240 u_int32_t rtalert = ~0; 241 int nxt, ours = 0; 242 struct ifnet *deliverifp = NULL; 243 struct sockaddr_in6 sa6; 244 u_int32_t srczone, dstzone; 245#ifdef PFIL_HOOKS 246 struct in6_addr odst; 247#endif 248 int srcrt = 0; 249 250 GIANT_REQUIRED; /* XXX for now */ 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 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 343 344 /* 345 * Check against address spoofing/corruption. 346 */ 347 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 348 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 349 /* 350 * XXX: "badscope" is not very suitable for a multicast source. 351 */ 352 ip6stat.ip6s_badscope++; 353 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 354 goto bad; 355 } 356 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 357 !(m->m_flags & M_LOOP)) { 358 /* 359 * In this case, the packet should come from the loopback 360 * interface. However, we cannot just check the if_flags, 361 * because ip6_mloopback() passes the "actual" interface 362 * as the outgoing/incoming interface. 363 */ 364 ip6stat.ip6s_badscope++; 365 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 366 goto bad; 367 } 368 369#ifdef ALTQ 370 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 371 /* packet is dropped by traffic conditioner */ 372 return; 373 } 374#endif 375 /* 376 * The following check is not documented in specs. A malicious 377 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 378 * and bypass security checks (act as if it was from 127.0.0.1 by using 379 * IPv6 src ::ffff:127.0.0.1). Be cautious. 380 * 381 * This check chokes if we are in an SIIT cloud. As none of BSDs 382 * support IPv4-less kernel compilation, we cannot support SIIT 383 * environment at all. So, it makes more sense for us to reject any 384 * malicious packets for non-SIIT environment, than try to do a 385 * partial support for SIIT environment. 386 */ 387 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 388 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 389 ip6stat.ip6s_badscope++; 390 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 391 goto bad; 392 } 393#if 0 394 /* 395 * Reject packets with IPv4 compatible addresses (auto tunnel). 396 * 397 * The code forbids auto tunnel relay case in RFC1933 (the check is 398 * stronger than RFC1933). We may want to re-enable it if mech-xx 399 * is revised to forbid relaying case. 400 */ 401 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 402 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 403 ip6stat.ip6s_badscope++; 404 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 405 goto bad; 406 } 407#endif 408 409 /* 410 * Drop packets if the link ID portion is already filled. 411 * XXX: this is technically not a good behavior. But, we internally 412 * use the field to disambiguate link-local addresses, so we cannot 413 * be generous against those a bit strange addresses. 414 */ 415 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 416 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 417 ip6->ip6_src.s6_addr16[1]) { 418 ip6stat.ip6s_badscope++; 419 goto bad; 420 } 421 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) || 422 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) && 423 ip6->ip6_dst.s6_addr16[1]) { 424 ip6stat.ip6s_badscope++; 425 goto bad; 426 } 427 } 428 429#ifdef PFIL_HOOKS 430 /* 431 * Run through list of hooks for input packets. 432 * 433 * NB: Beware of the destination address changing 434 * (e.g. by NAT rewriting). When this happens, 435 * tell ip6_forward to do the right thing. 436 */ 437 odst = ip6->ip6_dst; 438 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 439 return; 440 if (m == NULL) /* consumed by filter */ 441 return; 442 ip6 = mtod(m, struct ip6_hdr *); 443 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 444#endif /* PFIL_HOOKS */ 445 446 /* 447 * Check with the firewall... 448 */ 449 if (ip6_fw_enable && ip6_fw_chk_ptr) { 450 u_short port = 0; 451 /* If ipfw says divert, we have to just drop packet */ 452 /* use port as a dummy argument */ 453 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 454 m_freem(m); 455 m = NULL; 456 } 457 if (!m) 458 return; 459 } 460 461 /* 462 * construct source and destination address structures with 463 * disambiguating their scope zones (if there is ambiguity). 464 * XXX: sin6_family and sin6_len will NOT be referred to, but we fill 465 * in these fields just in case. 466 */ 467 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_src, &srczone) || 468 in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_dst, &dstzone)) { 469 /* 470 * Note that these generic checks cover cases that src or 471 * dst are the loopback address and the receiving interface 472 * is not loopback. 473 */ 474 ip6stat.ip6s_badscope++; 475 goto bad; 476 } 477 478 bzero(&sa6, sizeof(sa6)); 479 sa6.sin6_family = AF_INET6; 480 sa6.sin6_len = sizeof(struct sockaddr_in6); 481 482 sa6.sin6_addr = ip6->ip6_src; 483 sa6.sin6_scope_id = srczone; 484 if (in6_embedscope(&ip6->ip6_src, &sa6, NULL, NULL)) { 485 /* XXX: should not happen */ 486 ip6stat.ip6s_badscope++; 487 goto bad; 488 } 489 490 sa6.sin6_addr = ip6->ip6_dst; 491 sa6.sin6_scope_id = dstzone; 492 if (in6_embedscope(&ip6->ip6_dst, &sa6, NULL, NULL)) { 493 /* XXX: should not happen */ 494 ip6stat.ip6s_badscope++; 495 goto bad; 496 } 497 498 /* XXX: ff01::%ifN awareness is not merged, yet. */ 499 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_src)) 500 ip6->ip6_src.s6_addr16[1] = 0; 501 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) 502 ip6->ip6_dst.s6_addr16[1] = 0; 503 504 /* 505 * Multicast check 506 */ 507 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 508 struct in6_multi *in6m = 0; 509 510 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 511 /* 512 * See if we belong to the destination multicast group on the 513 * arrival interface. 514 */ 515 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 516 if (in6m) 517 ours = 1; 518 else if (!ip6_mrouter) { 519 ip6stat.ip6s_notmember++; 520 ip6stat.ip6s_cantforward++; 521 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 522 goto bad; 523 } 524 deliverifp = m->m_pkthdr.rcvif; 525 goto hbhcheck; 526 } 527 528 /* 529 * Unicast check 530 */ 531 if (ip6_forward_rt.ro_rt != NULL && 532 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 533 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 534 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 535 ip6stat.ip6s_forward_cachehit++; 536 else { 537 struct sockaddr_in6 *dst6; 538 539 if (ip6_forward_rt.ro_rt) { 540 /* route is down or destination is different */ 541 ip6stat.ip6s_forward_cachemiss++; 542 RTFREE(ip6_forward_rt.ro_rt); 543 ip6_forward_rt.ro_rt = 0; 544 } 545 546 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 547 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 548 dst6->sin6_len = sizeof(struct sockaddr_in6); 549 dst6->sin6_family = AF_INET6; 550 dst6->sin6_addr = ip6->ip6_dst; 551 552 rtalloc((struct route *)&ip6_forward_rt); 553 } 554 555#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 556 557 /* 558 * Accept the packet if the forwarding interface to the destination 559 * according to the routing table is the loopback interface, 560 * unless the associated route has a gateway. 561 * Note that this approach causes to accept a packet if there is a 562 * route to the loopback interface for the destination of the packet. 563 * But we think it's even useful in some situations, e.g. when using 564 * a special daemon which wants to intercept the packet. 565 * 566 * XXX: some OSes automatically make a cloned route for the destination 567 * of an outgoing packet. If the outgoing interface of the packet 568 * is a loopback one, the kernel would consider the packet to be 569 * accepted, even if we have no such address assinged on the interface. 570 * We check the cloned flag of the route entry to reject such cases, 571 * assuming that route entries for our own addresses are not made by 572 * cloning (it should be true because in6_addloop explicitly installs 573 * the host route). However, we might have to do an explicit check 574 * while it would be less efficient. Or, should we rather install a 575 * reject route for such a case? 576 */ 577 if (ip6_forward_rt.ro_rt && 578 (ip6_forward_rt.ro_rt->rt_flags & 579 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 580#ifdef RTF_WASCLONED 581 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 582#endif 583#ifdef RTF_CLONED 584 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 585#endif 586#if 0 587 /* 588 * The check below is redundant since the comparison of 589 * the destination and the key of the rtentry has 590 * already done through looking up the routing table. 591 */ 592 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 593 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 594#endif 595 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 596 struct in6_ifaddr *ia6 = 597 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 598 599 /* 600 * record address information into m_tag. 601 */ 602 (void)ip6_setdstifaddr(m, ia6); 603 604 /* 605 * packets to a tentative, duplicated, or somehow invalid 606 * address must not be accepted. 607 */ 608 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 609 /* this address is ready */ 610 ours = 1; 611 deliverifp = ia6->ia_ifp; /* correct? */ 612 /* Count the packet in the ip address stats */ 613 ia6->ia_ifa.if_ipackets++; 614 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 615 goto hbhcheck; 616 } else { 617 /* address is not ready, so discard the packet. */ 618 nd6log((LOG_INFO, 619 "ip6_input: packet to an unready address %s->%s\n", 620 ip6_sprintf(&ip6->ip6_src), 621 ip6_sprintf(&ip6->ip6_dst))); 622 623 goto bad; 624 } 625 } 626 627 /* 628 * FAITH (Firewall Aided Internet Translator) 629 */ 630 if (ip6_keepfaith) { 631 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 632 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 633 /* XXX do we need more sanity checks? */ 634 ours = 1; 635 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 636 goto hbhcheck; 637 } 638 } 639 640 /* 641 * Now there is no reason to process the packet if it's not our own 642 * and we're not a router. 643 */ 644 if (!ip6_forwarding) { 645 ip6stat.ip6s_cantforward++; 646 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 647 goto bad; 648 } 649 650 hbhcheck: 651 /* 652 * record address information into m_tag, if we don't have one yet. 653 * note that we are unable to record it, if the address is not listed 654 * as our interface address (e.g. multicast addresses, addresses 655 * within FAITH prefixes and such). 656 */ 657 if (deliverifp && !ip6_getdstifaddr(m)) { 658 struct in6_ifaddr *ia6; 659 660 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 661 if (ia6) { 662 if (!ip6_setdstifaddr(m, ia6)) { 663 /* 664 * XXX maybe we should drop the packet here, 665 * as we could not provide enough information 666 * to the upper layers. 667 */ 668 } 669 } 670 } 671 672 /* 673 * Process Hop-by-Hop options header if it's contained. 674 * m may be modified in ip6_hopopts_input(). 675 * If a JumboPayload option is included, plen will also be modified. 676 */ 677 plen = (u_int32_t)ntohs(ip6->ip6_plen); 678 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 679 struct ip6_hbh *hbh; 680 681 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 682#if 0 /*touches NULL pointer*/ 683 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 684#endif 685 return; /* m have already been freed */ 686 } 687 688 /* adjust pointer */ 689 ip6 = mtod(m, struct ip6_hdr *); 690 691 /* 692 * if the payload length field is 0 and the next header field 693 * indicates Hop-by-Hop Options header, then a Jumbo Payload 694 * option MUST be included. 695 */ 696 if (ip6->ip6_plen == 0 && plen == 0) { 697 /* 698 * Note that if a valid jumbo payload option is 699 * contained, ip6_hopopts_input() must set a valid 700 * (non-zero) payload length to the variable plen. 701 */ 702 ip6stat.ip6s_badoptions++; 703 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 704 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 705 icmp6_error(m, ICMP6_PARAM_PROB, 706 ICMP6_PARAMPROB_HEADER, 707 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 708 return; 709 } 710#ifndef PULLDOWN_TEST 711 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 712 hbh = (struct ip6_hbh *)(ip6 + 1); 713#else 714 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 715 sizeof(struct ip6_hbh)); 716 if (hbh == NULL) { 717 ip6stat.ip6s_tooshort++; 718 return; 719 } 720#endif 721 nxt = hbh->ip6h_nxt; 722 723 /* 724 * accept the packet if a router alert option is included 725 * and we act as an IPv6 router. 726 */ 727 if (rtalert != ~0 && ip6_forwarding) 728 ours = 1; 729 } else 730 nxt = ip6->ip6_nxt; 731 732 /* 733 * Check that the amount of data in the buffers 734 * is as at least much as the IPv6 header would have us expect. 735 * Trim mbufs if longer than we expect. 736 * Drop packet if shorter than we expect. 737 */ 738 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 739 ip6stat.ip6s_tooshort++; 740 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 741 goto bad; 742 } 743 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 744 if (m->m_len == m->m_pkthdr.len) { 745 m->m_len = sizeof(struct ip6_hdr) + plen; 746 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 747 } else 748 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 749 } 750 751 /* 752 * Forward if desirable. 753 */ 754 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 755 /* 756 * If we are acting as a multicast router, all 757 * incoming multicast packets are passed to the 758 * kernel-level multicast forwarding function. 759 * The packet is returned (relatively) intact; if 760 * ip6_mforward() returns a non-zero value, the packet 761 * must be discarded, else it may be accepted below. 762 */ 763 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 764 ip6stat.ip6s_cantforward++; 765 m_freem(m); 766 return; 767 } 768 if (!ours) { 769 m_freem(m); 770 return; 771 } 772 } else if (!ours) { 773 ip6_forward(m, srcrt); 774 return; 775 } 776 777 ip6 = mtod(m, struct ip6_hdr *); 778 779 /* 780 * Malicious party may be able to use IPv4 mapped addr to confuse 781 * tcp/udp stack and bypass security checks (act as if it was from 782 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 783 * 784 * For SIIT end node behavior, you may want to disable the check. 785 * However, you will become vulnerable to attacks using IPv4 mapped 786 * source. 787 */ 788 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 789 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 790 ip6stat.ip6s_badscope++; 791 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 792 goto bad; 793 } 794 795 /* 796 * Tell launch routine the next header 797 */ 798 ip6stat.ip6s_delivered++; 799 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 800 nest = 0; 801 802 while (nxt != IPPROTO_DONE) { 803 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 804 ip6stat.ip6s_toomanyhdr++; 805 goto bad; 806 } 807 808 /* 809 * protection against faulty packet - there should be 810 * more sanity checks in header chain processing. 811 */ 812 if (m->m_pkthdr.len < off) { 813 ip6stat.ip6s_tooshort++; 814 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 815 goto bad; 816 } 817 818#ifdef IPSEC 819 /* 820 * enforce IPsec policy checking if we are seeing last header. 821 * note that we do not visit this with protocols with pcb layer 822 * code - like udp/tcp/raw ip. 823 */ 824 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 825 ipsec6_in_reject(m, NULL)) { 826 ipsec6stat.in_polvio++; 827 goto bad; 828 } 829#endif 830 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 831 } 832 return; 833 bad: 834 m_freem(m); 835} 836 837/* 838 * set/grab in6_ifaddr correspond to IPv6 destination address. 839 * XXX backward compatibility wrapper 840 */ 841static struct ip6aux * 842ip6_setdstifaddr(m, ia6) 843 struct mbuf *m; 844 struct in6_ifaddr *ia6; 845{ 846 struct ip6aux *ip6a; 847 848 ip6a = ip6_addaux(m); 849 if (ip6a) 850 ip6a->ip6a_dstia6 = ia6; 851 return ip6a; /* NULL if failed to set */ 852} 853 854struct in6_ifaddr * 855ip6_getdstifaddr(m) 856 struct mbuf *m; 857{ 858 struct ip6aux *ip6a; 859 860 ip6a = ip6_findaux(m); 861 if (ip6a) 862 return ip6a->ip6a_dstia6; 863 else 864 return NULL; 865} 866 867/* 868 * Hop-by-Hop options header processing. If a valid jumbo payload option is 869 * included, the real payload length will be stored in plenp. 870 */ 871static int 872ip6_hopopts_input(plenp, rtalertp, mp, offp) 873 u_int32_t *plenp; 874 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 875 struct mbuf **mp; 876 int *offp; 877{ 878 struct mbuf *m = *mp; 879 int off = *offp, hbhlen; 880 struct ip6_hbh *hbh; 881 u_int8_t *opt; 882 883 /* validation of the length of the header */ 884#ifndef PULLDOWN_TEST 885 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 886 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 887 hbhlen = (hbh->ip6h_len + 1) << 3; 888 889 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 890 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 891#else 892 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 893 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 894 if (hbh == NULL) { 895 ip6stat.ip6s_tooshort++; 896 return -1; 897 } 898 hbhlen = (hbh->ip6h_len + 1) << 3; 899 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 900 hbhlen); 901 if (hbh == NULL) { 902 ip6stat.ip6s_tooshort++; 903 return -1; 904 } 905#endif 906 off += hbhlen; 907 hbhlen -= sizeof(struct ip6_hbh); 908 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 909 910 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 911 hbhlen, rtalertp, plenp) < 0) 912 return (-1); 913 914 *offp = off; 915 *mp = m; 916 return (0); 917} 918 919/* 920 * Search header for all Hop-by-hop options and process each option. 921 * This function is separate from ip6_hopopts_input() in order to 922 * handle a case where the sending node itself process its hop-by-hop 923 * options header. In such a case, the function is called from ip6_output(). 924 * 925 * The function assumes that hbh header is located right after the IPv6 header 926 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 927 * opthead + hbhlen is located in continuous memory region. 928 */ 929int 930ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 931 struct mbuf *m; 932 u_int8_t *opthead; 933 int hbhlen; 934 u_int32_t *rtalertp; 935 u_int32_t *plenp; 936{ 937 struct ip6_hdr *ip6; 938 int optlen = 0; 939 u_int8_t *opt = opthead; 940 u_int16_t rtalert_val; 941 u_int32_t jumboplen; 942 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 943 944 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 945 switch (*opt) { 946 case IP6OPT_PAD1: 947 optlen = 1; 948 break; 949 case IP6OPT_PADN: 950 if (hbhlen < IP6OPT_MINLEN) { 951 ip6stat.ip6s_toosmall++; 952 goto bad; 953 } 954 optlen = *(opt + 1) + 2; 955 break; 956 case IP6OPT_ROUTER_ALERT: 957 /* XXX may need check for alignment */ 958 if (hbhlen < IP6OPT_RTALERT_LEN) { 959 ip6stat.ip6s_toosmall++; 960 goto bad; 961 } 962 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 963 /* XXX stat */ 964 icmp6_error(m, ICMP6_PARAM_PROB, 965 ICMP6_PARAMPROB_HEADER, 966 erroff + opt + 1 - opthead); 967 return (-1); 968 } 969 optlen = IP6OPT_RTALERT_LEN; 970 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 971 *rtalertp = ntohs(rtalert_val); 972 break; 973 case IP6OPT_JUMBO: 974 /* XXX may need check for alignment */ 975 if (hbhlen < IP6OPT_JUMBO_LEN) { 976 ip6stat.ip6s_toosmall++; 977 goto bad; 978 } 979 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 980 /* XXX stat */ 981 icmp6_error(m, ICMP6_PARAM_PROB, 982 ICMP6_PARAMPROB_HEADER, 983 erroff + opt + 1 - opthead); 984 return (-1); 985 } 986 optlen = IP6OPT_JUMBO_LEN; 987 988 /* 989 * IPv6 packets that have non 0 payload length 990 * must not contain a jumbo payload option. 991 */ 992 ip6 = mtod(m, struct ip6_hdr *); 993 if (ip6->ip6_plen) { 994 ip6stat.ip6s_badoptions++; 995 icmp6_error(m, ICMP6_PARAM_PROB, 996 ICMP6_PARAMPROB_HEADER, 997 erroff + opt - opthead); 998 return (-1); 999 } 1000 1001 /* 1002 * We may see jumbolen in unaligned location, so 1003 * we'd need to perform bcopy(). 1004 */ 1005 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1006 jumboplen = (u_int32_t)htonl(jumboplen); 1007 1008#if 1 1009 /* 1010 * if there are multiple jumbo payload options, 1011 * *plenp will be non-zero and the packet will be 1012 * rejected. 1013 * the behavior may need some debate in ipngwg - 1014 * multiple options does not make sense, however, 1015 * there's no explicit mention in specification. 1016 */ 1017 if (*plenp != 0) { 1018 ip6stat.ip6s_badoptions++; 1019 icmp6_error(m, ICMP6_PARAM_PROB, 1020 ICMP6_PARAMPROB_HEADER, 1021 erroff + opt + 2 - opthead); 1022 return (-1); 1023 } 1024#endif 1025 1026 /* 1027 * jumbo payload length must be larger than 65535. 1028 */ 1029 if (jumboplen <= IPV6_MAXPACKET) { 1030 ip6stat.ip6s_badoptions++; 1031 icmp6_error(m, ICMP6_PARAM_PROB, 1032 ICMP6_PARAMPROB_HEADER, 1033 erroff + opt + 2 - opthead); 1034 return (-1); 1035 } 1036 *plenp = jumboplen; 1037 1038 break; 1039 default: /* unknown option */ 1040 if (hbhlen < IP6OPT_MINLEN) { 1041 ip6stat.ip6s_toosmall++; 1042 goto bad; 1043 } 1044 optlen = ip6_unknown_opt(opt, m, 1045 erroff + opt - opthead); 1046 if (optlen == -1) 1047 return (-1); 1048 optlen += 2; 1049 break; 1050 } 1051 } 1052 1053 return (0); 1054 1055 bad: 1056 m_freem(m); 1057 return (-1); 1058} 1059 1060/* 1061 * Unknown option processing. 1062 * The third argument `off' is the offset from the IPv6 header to the option, 1063 * which is necessary if the IPv6 header the and option header and IPv6 header 1064 * is not continuous in order to return an ICMPv6 error. 1065 */ 1066int 1067ip6_unknown_opt(optp, m, off) 1068 u_int8_t *optp; 1069 struct mbuf *m; 1070 int off; 1071{ 1072 struct ip6_hdr *ip6; 1073 1074 switch (IP6OPT_TYPE(*optp)) { 1075 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1076 return ((int)*(optp + 1)); 1077 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1078 m_freem(m); 1079 return (-1); 1080 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1081 ip6stat.ip6s_badoptions++; 1082 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1083 return (-1); 1084 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1085 ip6stat.ip6s_badoptions++; 1086 ip6 = mtod(m, struct ip6_hdr *); 1087 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1088 (m->m_flags & (M_BCAST|M_MCAST))) 1089 m_freem(m); 1090 else 1091 icmp6_error(m, ICMP6_PARAM_PROB, 1092 ICMP6_PARAMPROB_OPTION, off); 1093 return (-1); 1094 } 1095 1096 m_freem(m); /* XXX: NOTREACHED */ 1097 return (-1); 1098} 1099 1100/* 1101 * Create the "control" list for this pcb. 1102 * The function will not modify mbuf chain at all. 1103 * 1104 * with KAME mbuf chain restriction: 1105 * The routine will be called from upper layer handlers like tcp6_input(). 1106 * Thus the routine assumes that the caller (tcp6_input) have already 1107 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1108 * very first mbuf on the mbuf chain. 1109 */ 1110void 1111ip6_savecontrol(in6p, m, mp) 1112 struct inpcb *in6p; 1113 struct mbuf *m, **mp; 1114{ 1115#define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1116 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1117 1118#ifdef SO_TIMESTAMP 1119 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1120 struct timeval tv; 1121 1122 microtime(&tv); 1123 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1124 SCM_TIMESTAMP, SOL_SOCKET); 1125 if (*mp) 1126 mp = &(*mp)->m_next; 1127 } 1128#endif 1129 1130 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1131 return; 1132 1133 /* RFC 2292 sec. 5 */ 1134 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1135 struct in6_pktinfo pi6; 1136 1137 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1138 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1139 pi6.ipi6_ifindex = 1140 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1141 1142 *mp = sbcreatecontrol((caddr_t) &pi6, 1143 sizeof(struct in6_pktinfo), 1144 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1145 if (*mp) 1146 mp = &(*mp)->m_next; 1147 } 1148 1149 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1150 int hlim = ip6->ip6_hlim & 0xff; 1151 1152 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1153 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1154 if (*mp) 1155 mp = &(*mp)->m_next; 1156 } 1157 1158 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1159 u_int32_t flowinfo; 1160 int tclass; 1161 1162 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1163 flowinfo >>= 20; 1164 1165 tclass = flowinfo & 0xff; 1166 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1167 IPV6_TCLASS, IPPROTO_IPV6); 1168 if (*mp) 1169 mp = &(*mp)->m_next; 1170 } 1171 1172 /* 1173 * IPV6_HOPOPTS socket option. Recall that we required super-user 1174 * privilege for the option (see ip6_ctloutput), but it might be too 1175 * strict, since there might be some hop-by-hop options which can be 1176 * returned to normal user. 1177 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1178 */ 1179 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1180 /* 1181 * Check if a hop-by-hop options header is contatined in the 1182 * received packet, and if so, store the options as ancillary 1183 * data. Note that a hop-by-hop options header must be 1184 * just after the IPv6 header, which is assured through the 1185 * IPv6 input processing. 1186 */ 1187 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1188 struct ip6_hbh *hbh; 1189 int hbhlen = 0; 1190#ifdef PULLDOWN_TEST 1191 struct mbuf *ext; 1192#endif 1193 1194#ifndef PULLDOWN_TEST 1195 hbh = (struct ip6_hbh *)(ip6 + 1); 1196 hbhlen = (hbh->ip6h_len + 1) << 3; 1197#else 1198 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1199 ip6->ip6_nxt); 1200 if (ext == NULL) { 1201 ip6stat.ip6s_tooshort++; 1202 return; 1203 } 1204 hbh = mtod(ext, struct ip6_hbh *); 1205 hbhlen = (hbh->ip6h_len + 1) << 3; 1206 if (hbhlen != ext->m_len) { 1207 m_freem(ext); 1208 ip6stat.ip6s_tooshort++; 1209 return; 1210 } 1211#endif 1212 1213 /* 1214 * XXX: We copy the whole header even if a 1215 * jumbo payload option is included, the option which 1216 * is to be removed before returning according to 1217 * RFC2292. 1218 * Note: this constraint is removed in 2292bis. 1219 */ 1220 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1221 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1222 IPPROTO_IPV6); 1223 if (*mp) 1224 mp = &(*mp)->m_next; 1225#ifdef PULLDOWN_TEST 1226 m_freem(ext); 1227#endif 1228 } 1229 } 1230 1231 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1232 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1233 1234 /* 1235 * Search for destination options headers or routing 1236 * header(s) through the header chain, and stores each 1237 * header as ancillary data. 1238 * Note that the order of the headers remains in 1239 * the chain of ancillary data. 1240 */ 1241 while (1) { /* is explicit loop prevention necessary? */ 1242 struct ip6_ext *ip6e = NULL; 1243 int elen; 1244#ifdef PULLDOWN_TEST 1245 struct mbuf *ext = NULL; 1246#endif 1247 1248 /* 1249 * if it is not an extension header, don't try to 1250 * pull it from the chain. 1251 */ 1252 switch (nxt) { 1253 case IPPROTO_DSTOPTS: 1254 case IPPROTO_ROUTING: 1255 case IPPROTO_HOPOPTS: 1256 case IPPROTO_AH: /* is it possible? */ 1257 break; 1258 default: 1259 goto loopend; 1260 } 1261 1262#ifndef PULLDOWN_TEST 1263 if (off + sizeof(*ip6e) > m->m_len) 1264 goto loopend; 1265 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1266 if (nxt == IPPROTO_AH) 1267 elen = (ip6e->ip6e_len + 2) << 2; 1268 else 1269 elen = (ip6e->ip6e_len + 1) << 3; 1270 if (off + elen > m->m_len) 1271 goto loopend; 1272#else 1273 ext = ip6_pullexthdr(m, off, nxt); 1274 if (ext == NULL) { 1275 ip6stat.ip6s_tooshort++; 1276 return; 1277 } 1278 ip6e = mtod(ext, struct ip6_ext *); 1279 if (nxt == IPPROTO_AH) 1280 elen = (ip6e->ip6e_len + 2) << 2; 1281 else 1282 elen = (ip6e->ip6e_len + 1) << 3; 1283 if (elen != ext->m_len) { 1284 m_freem(ext); 1285 ip6stat.ip6s_tooshort++; 1286 return; 1287 } 1288#endif 1289 1290 switch (nxt) { 1291 case IPPROTO_DSTOPTS: 1292 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1293 break; 1294 1295 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1296 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1297 IPPROTO_IPV6); 1298 if (*mp) 1299 mp = &(*mp)->m_next; 1300 break; 1301 case IPPROTO_ROUTING: 1302 if (!in6p->in6p_flags & IN6P_RTHDR) 1303 break; 1304 1305 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1306 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1307 IPPROTO_IPV6); 1308 if (*mp) 1309 mp = &(*mp)->m_next; 1310 break; 1311 case IPPROTO_HOPOPTS: 1312 case IPPROTO_AH: /* is it possible? */ 1313 break; 1314 1315 default: 1316 /* 1317 * other cases have been filtered in the above. 1318 * none will visit this case. here we supply 1319 * the code just in case (nxt overwritten or 1320 * other cases). 1321 */ 1322#ifdef PULLDOWN_TEST 1323 m_freem(ext); 1324#endif 1325 goto loopend; 1326 1327 } 1328 1329 /* proceed with the next header. */ 1330 off += elen; 1331 nxt = ip6e->ip6e_nxt; 1332 ip6e = NULL; 1333#ifdef PULLDOWN_TEST 1334 m_freem(ext); 1335 ext = NULL; 1336#endif 1337 } 1338 loopend: 1339 ; 1340 } 1341 1342#undef IS2292 1343} 1344 1345void 1346ip6_notify_pmtu(in6p, dst, mtu) 1347 struct inpcb *in6p; 1348 struct sockaddr_in6 *dst; 1349 u_int32_t *mtu; 1350{ 1351 struct socket *so; 1352 struct mbuf *m_mtu; 1353 struct ip6_mtuinfo mtuctl; 1354 1355 so = in6p->inp_socket; 1356 1357 if (mtu == NULL) 1358 return; 1359 1360#ifdef DIAGNOSTIC 1361 if (so == NULL) /* I believe this is impossible */ 1362 panic("ip6_notify_pmtu: socket is NULL"); 1363#endif 1364 1365 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1366 mtuctl.ip6m_mtu = *mtu; 1367 mtuctl.ip6m_addr = *dst; 1368 in6_recoverscope(&mtuctl.ip6m_addr, &mtuctl.ip6m_addr.sin6_addr, NULL); 1369 1370 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1371 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1372 return; 1373 1374 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1375 == 0) { 1376 m_freem(m_mtu); 1377 /* XXX: should count statistics */ 1378 } else 1379 sorwakeup(so); 1380 1381 return; 1382} 1383 1384#ifdef PULLDOWN_TEST 1385/* 1386 * pull single extension header from mbuf chain. returns single mbuf that 1387 * contains the result, or NULL on error. 1388 */ 1389static struct mbuf * 1390ip6_pullexthdr(m, off, nxt) 1391 struct mbuf *m; 1392 size_t off; 1393 int nxt; 1394{ 1395 struct ip6_ext ip6e; 1396 size_t elen; 1397 struct mbuf *n; 1398 1399#ifdef DIAGNOSTIC 1400 switch (nxt) { 1401 case IPPROTO_DSTOPTS: 1402 case IPPROTO_ROUTING: 1403 case IPPROTO_HOPOPTS: 1404 case IPPROTO_AH: /* is it possible? */ 1405 break; 1406 default: 1407 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1408 } 1409#endif 1410 1411 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1412 if (nxt == IPPROTO_AH) 1413 elen = (ip6e.ip6e_len + 2) << 2; 1414 else 1415 elen = (ip6e.ip6e_len + 1) << 3; 1416 1417 MGET(n, M_DONTWAIT, MT_DATA); 1418 if (n && elen >= MLEN) { 1419 MCLGET(n, M_DONTWAIT); 1420 if ((n->m_flags & M_EXT) == 0) { 1421 m_free(n); 1422 n = NULL; 1423 } 1424 } 1425 if (!n) 1426 return NULL; 1427 1428 n->m_len = 0; 1429 if (elen >= M_TRAILINGSPACE(n)) { 1430 m_free(n); 1431 return NULL; 1432 } 1433 1434 m_copydata(m, off, elen, mtod(n, caddr_t)); 1435 n->m_len = elen; 1436 return n; 1437} 1438#endif 1439 1440/* 1441 * Get pointer to the previous header followed by the header 1442 * currently processed. 1443 * XXX: This function supposes that 1444 * M includes all headers, 1445 * the next header field and the header length field of each header 1446 * are valid, and 1447 * the sum of each header length equals to OFF. 1448 * Because of these assumptions, this function must be called very 1449 * carefully. Moreover, it will not be used in the near future when 1450 * we develop `neater' mechanism to process extension headers. 1451 */ 1452char * 1453ip6_get_prevhdr(m, off) 1454 struct mbuf *m; 1455 int off; 1456{ 1457 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1458 1459 if (off == sizeof(struct ip6_hdr)) 1460 return (&ip6->ip6_nxt); 1461 else { 1462 int len, nxt; 1463 struct ip6_ext *ip6e = NULL; 1464 1465 nxt = ip6->ip6_nxt; 1466 len = sizeof(struct ip6_hdr); 1467 while (len < off) { 1468 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1469 1470 switch (nxt) { 1471 case IPPROTO_FRAGMENT: 1472 len += sizeof(struct ip6_frag); 1473 break; 1474 case IPPROTO_AH: 1475 len += (ip6e->ip6e_len + 2) << 2; 1476 break; 1477 default: 1478 len += (ip6e->ip6e_len + 1) << 3; 1479 break; 1480 } 1481 nxt = ip6e->ip6e_nxt; 1482 } 1483 if (ip6e) 1484 return (&ip6e->ip6e_nxt); 1485 else 1486 return NULL; 1487 } 1488} 1489 1490/* 1491 * get next header offset. m will be retained. 1492 */ 1493int 1494ip6_nexthdr(m, off, proto, nxtp) 1495 struct mbuf *m; 1496 int off; 1497 int proto; 1498 int *nxtp; 1499{ 1500 struct ip6_hdr ip6; 1501 struct ip6_ext ip6e; 1502 struct ip6_frag fh; 1503 1504 /* just in case */ 1505 if (m == NULL) 1506 panic("ip6_nexthdr: m == NULL"); 1507 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1508 return -1; 1509 1510 switch (proto) { 1511 case IPPROTO_IPV6: 1512 if (m->m_pkthdr.len < off + sizeof(ip6)) 1513 return -1; 1514 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1515 if (nxtp) 1516 *nxtp = ip6.ip6_nxt; 1517 off += sizeof(ip6); 1518 return off; 1519 1520 case IPPROTO_FRAGMENT: 1521 /* 1522 * terminate parsing if it is not the first fragment, 1523 * it does not make sense to parse through it. 1524 */ 1525 if (m->m_pkthdr.len < off + sizeof(fh)) 1526 return -1; 1527 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1528 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1529 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1530 return -1; 1531 if (nxtp) 1532 *nxtp = fh.ip6f_nxt; 1533 off += sizeof(struct ip6_frag); 1534 return off; 1535 1536 case IPPROTO_AH: 1537 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1538 return -1; 1539 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1540 if (nxtp) 1541 *nxtp = ip6e.ip6e_nxt; 1542 off += (ip6e.ip6e_len + 2) << 2; 1543 return off; 1544 1545 case IPPROTO_HOPOPTS: 1546 case IPPROTO_ROUTING: 1547 case IPPROTO_DSTOPTS: 1548 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1549 return -1; 1550 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1551 if (nxtp) 1552 *nxtp = ip6e.ip6e_nxt; 1553 off += (ip6e.ip6e_len + 1) << 3; 1554 return off; 1555 1556 case IPPROTO_NONE: 1557 case IPPROTO_ESP: 1558 case IPPROTO_IPCOMP: 1559 /* give up */ 1560 return -1; 1561 1562 default: 1563 return -1; 1564 } 1565 1566 return -1; 1567} 1568 1569/* 1570 * get offset for the last header in the chain. m will be kept untainted. 1571 */ 1572int 1573ip6_lasthdr(m, off, proto, nxtp) 1574 struct mbuf *m; 1575 int off; 1576 int proto; 1577 int *nxtp; 1578{ 1579 int newoff; 1580 int nxt; 1581 1582 if (!nxtp) { 1583 nxt = -1; 1584 nxtp = &nxt; 1585 } 1586 while (1) { 1587 newoff = ip6_nexthdr(m, off, proto, nxtp); 1588 if (newoff < 0) 1589 return off; 1590 else if (newoff < off) 1591 return -1; /* invalid */ 1592 else if (newoff == off) 1593 return newoff; 1594 1595 off = newoff; 1596 proto = *nxtp; 1597 } 1598} 1599 1600struct ip6aux * 1601ip6_addaux(m) 1602 struct mbuf *m; 1603{ 1604 struct m_tag *mtag; 1605 1606 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1607 if (!mtag) { 1608 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1609 M_NOWAIT); 1610 if (mtag) { 1611 m_tag_prepend(m, mtag); 1612 bzero(mtag + 1, sizeof(struct ip6aux)); 1613 } 1614 } 1615 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1616} 1617 1618struct ip6aux * 1619ip6_findaux(m) 1620 struct mbuf *m; 1621{ 1622 struct m_tag *mtag; 1623 1624 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1625 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1626} 1627 1628void 1629ip6_delaux(m) 1630 struct mbuf *m; 1631{ 1632 struct m_tag *mtag; 1633 1634 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1635 if (mtag) 1636 m_tag_delete(m, mtag); 1637} 1638 1639/* 1640 * System control for IP6 1641 */ 1642 1643u_char inet6ctlerrmap[PRC_NCMDS] = { 1644 0, 0, 0, 0, 1645 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1646 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1647 EMSGSIZE, EHOSTUNREACH, 0, 0, 1648 0, 0, 0, 0, 1649 ENOPROTOOPT 1650}; 1651