1 /* $FreeBSD$ */ 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 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/malloc.h> 72 #include <sys/mbuf.h> 73 #include <sys/proc.h> 74 #include <sys/domain.h> 75 #include <sys/protosw.h> 76 #include <sys/socket.h> 77 #include <sys/socketvar.h> 78 #include <sys/errno.h> 79 #include <sys/time.h> 80 #include <sys/kernel.h> 81 #include <sys/syslog.h> 82 83 #include <net/if.h> 84 #include <net/if_types.h> 85 #include <net/if_dl.h> 86 #include <net/route.h> 87 #include <net/netisr.h> 88 #include <net/pfil.h> 89 90 #include <netinet/in.h> 91 #include <netinet/in_systm.h> 92 #ifdef INET 93 #include <netinet/ip.h> 94 #include <netinet/ip_icmp.h> 95 #endif /* INET */ 96 #include <netinet/ip6.h> 97 #include <netinet6/in6_var.h> 98 #include <netinet6/ip6_var.h> 99 #include <netinet/in_pcb.h> 100 #include <netinet/icmp6.h> 101 #include <netinet6/scope6_var.h> 102 #include <netinet6/in6_ifattach.h> 103 #include <netinet6/nd6.h> 104 105 #ifdef IPSEC 106 #include <netinet6/ipsec.h> 107 #ifdef INET6 108 #include <netinet6/ipsec6.h> 109 #endif 110 #endif 111 112 #ifdef FAST_IPSEC 113 #include <netipsec/ipsec.h> 114 #include <netipsec/ipsec6.h> 115 #define IPSEC 116 #endif /* FAST_IPSEC */ 117 118 #include <netinet6/ip6_fw.h> 119 120 #include <netinet6/ip6protosw.h> 121 122 #include <net/net_osdep.h> 123 124 extern struct domain inet6domain; 125 126 u_char ip6_protox[IPPROTO_MAX]; 127 static struct ifqueue ip6intrq; 128 static int ip6qmaxlen = IFQ_MAXLEN; 129 struct in6_ifaddr *in6_ifaddr; 130 131 extern struct callout in6_tmpaddrtimer_ch; 132 133 int ip6_forward_srcrt; /* XXX */ 134 int ip6_sourcecheck; /* XXX */ 135 int ip6_sourcecheck_interval; /* XXX */ 136 137 int ip6_ours_check_algorithm; 138 139 struct pfil_head inet6_pfil_hook; 140 141 /* firewall hooks */ 142 ip6_fw_chk_t *ip6_fw_chk_ptr; 143 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 144 int ip6_fw_enable = 1; 145 146 struct ip6stat ip6stat; 147 148 static void ip6_init2 __P((void *)); 149 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 150 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 151 #ifdef PULLDOWN_TEST 152 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 153 #endif 154 155 /* 156 * IP6 initialization: fill in IP6 protocol switch table. 157 * All protocols not implemented in kernel go to raw IP6 protocol handler. 158 */ 159 void 160 ip6_init() 161 { 162 struct ip6protosw *pr; 163 int i; 164 165 #ifdef DIAGNOSTIC 166 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 167 panic("sizeof(protosw) != sizeof(ip6protosw)"); 168 #endif 169 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 170 if (pr == 0) 171 panic("ip6_init"); 172 173 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 174 for (i = 0; i < IPPROTO_MAX; i++) 175 ip6_protox[i] = pr - inet6sw; 176 /* 177 * Cycle through IP protocols and put them into the appropriate place 178 * in ip6_protox[]. 179 */ 180 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 181 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 182 if (pr->pr_domain->dom_family == PF_INET6 && 183 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 184 /* Be careful to only index valid IP protocols. */ 185 if (pr->pr_protocol < IPPROTO_MAX) 186 ip6_protox[pr->pr_protocol] = pr - inet6sw; 187 } 188 189 /* Initialize packet filter hooks. */ 190 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 191 inet6_pfil_hook.ph_af = AF_INET6; 192 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 193 printf("%s: WARNING: unable to register pfil hook, " 194 "error %d\n", __func__, i); 195 196 ip6intrq.ifq_maxlen = ip6qmaxlen; 197 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 198 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 199 scope6_init(); 200 addrsel_policy_init(); 201 nd6_init(); 202 frag6_init(); 203 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 204 } 205 206 static void 207 ip6_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 /* timer for regeneranation of temporary addresses randomize ID */ 216 callout_init(&in6_tmpaddrtimer_ch, 0); 217 callout_reset(&in6_tmpaddrtimer_ch, 218 (ip6_temp_preferred_lifetime - ip6_desync_factor - 219 ip6_temp_regen_advance) * hz, 220 in6_tmpaddrtimer, NULL); 221 } 222 223 /* cheat */ 224 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 225 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 226 227 extern struct route_in6 ip6_forward_rt; 228 229 void 230 ip6_input(m) 231 struct mbuf *m; 232 { 233 struct ip6_hdr *ip6; 234 int off = sizeof(struct ip6_hdr), nest; 235 u_int32_t plen; 236 u_int32_t rtalert = ~0; 237 int nxt, ours = 0; 238 struct ifnet *deliverifp = NULL; 239 struct in6_addr odst; 240 int srcrt = 0; 241 242 GIANT_REQUIRED; /* XXX for now */ 243 #ifdef IPSEC 244 /* 245 * should the inner packet be considered authentic? 246 * see comment in ah4_input(). 247 */ 248 if (m) { 249 m->m_flags &= ~M_AUTHIPHDR; 250 m->m_flags &= ~M_AUTHIPDGM; 251 } 252 #endif 253 254 /* 255 * make sure we don't have onion peering information into m_tag. 256 */ 257 ip6_delaux(m); 258 259 /* 260 * mbuf statistics 261 */ 262 if (m->m_flags & M_EXT) { 263 if (m->m_next) 264 ip6stat.ip6s_mext2m++; 265 else 266 ip6stat.ip6s_mext1++; 267 } else { 268 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 269 if (m->m_next) { 270 if (m->m_flags & M_LOOP) { 271 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 272 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 273 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 274 else 275 ip6stat.ip6s_m2m[0]++; 276 } else 277 ip6stat.ip6s_m1++; 278 #undef M2MMAX 279 } 280 281 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 282 ip6stat.ip6s_total++; 283 284 #ifndef PULLDOWN_TEST 285 /* 286 * L2 bridge code and some other code can return mbuf chain 287 * that does not conform to KAME requirement. too bad. 288 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 289 */ 290 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 291 struct mbuf *n; 292 293 MGETHDR(n, M_DONTWAIT, MT_HEADER); 294 if (n) 295 M_MOVE_PKTHDR(n, m); 296 if (n && n->m_pkthdr.len > MHLEN) { 297 MCLGET(n, M_DONTWAIT); 298 if ((n->m_flags & M_EXT) == 0) { 299 m_freem(n); 300 n = NULL; 301 } 302 } 303 if (n == NULL) { 304 m_freem(m); 305 return; /* ENOBUFS */ 306 } 307 308 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 309 n->m_len = n->m_pkthdr.len; 310 m_freem(m); 311 m = n; 312 } 313 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 314 #endif 315 316 if (m->m_len < sizeof(struct ip6_hdr)) { 317 struct ifnet *inifp; 318 inifp = m->m_pkthdr.rcvif; 319 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 320 ip6stat.ip6s_toosmall++; 321 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 322 return; 323 } 324 } 325 326 ip6 = mtod(m, struct ip6_hdr *); 327 328 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 329 ip6stat.ip6s_badvers++; 330 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 331 goto bad; 332 } 333 334 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 335 336 /* 337 * Check against address spoofing/corruption. 338 */ 339 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 340 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 341 /* 342 * XXX: "badscope" is not very suitable for a multicast source. 343 */ 344 ip6stat.ip6s_badscope++; 345 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 346 goto bad; 347 } 348 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 349 !(m->m_flags & M_LOOP)) { 350 /* 351 * In this case, the packet should come from the loopback 352 * interface. However, we cannot just check the if_flags, 353 * because ip6_mloopback() passes the "actual" interface 354 * as the outgoing/incoming interface. 355 */ 356 ip6stat.ip6s_badscope++; 357 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 358 goto bad; 359 } 360 361 #ifdef ALTQ 362 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 363 /* packet is dropped by traffic conditioner */ 364 return; 365 } 366 #endif 367 /* 368 * The following check is not documented in specs. A malicious 369 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 370 * and bypass security checks (act as if it was from 127.0.0.1 by using 371 * IPv6 src ::ffff:127.0.0.1). Be cautious. 372 * 373 * This check chokes if we are in an SIIT cloud. As none of BSDs 374 * support IPv4-less kernel compilation, we cannot support SIIT 375 * environment at all. So, it makes more sense for us to reject any 376 * malicious packets for non-SIIT environment, than try to do a 377 * partial support for SIIT environment. 378 */ 379 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 380 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 381 ip6stat.ip6s_badscope++; 382 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 383 goto bad; 384 } 385 #if 0 386 /* 387 * Reject packets with IPv4 compatible addresses (auto tunnel). 388 * 389 * The code forbids auto tunnel relay case in RFC1933 (the check is 390 * stronger than RFC1933). We may want to re-enable it if mech-xx 391 * is revised to forbid relaying case. 392 */ 393 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 394 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 395 ip6stat.ip6s_badscope++; 396 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 397 goto bad; 398 } 399 #endif 400 401 /* 402 * Disambiguate address scope zones (if there is ambiguity). 403 * We first make sure that the original source or destination address 404 * is not in our internal form for scoped addresses. Such addresses 405 * are not necessarily invalid spec-wise, but we cannot accept them due 406 * to the usage conflict. 407 * in6_setscope() then also checks and rejects the cases where src or 408 * dst are the loopback address and the receiving interface 409 * is not loopback. 410 */ 411 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 412 ip6stat.ip6s_badscope++; /* XXX */ 413 goto bad; 414 } 415 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 416 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 417 ip6stat.ip6s_badscope++; 418 goto bad; 419 } 420 421 /* 422 * Run through list of hooks for input packets. 423 * 424 * NB: Beware of the destination address changing 425 * (e.g. by NAT rewriting). When this happens, 426 * tell ip6_forward to do the right thing. 427 */ 428 odst = ip6->ip6_dst; 429 430 /* Jump over all PFIL processing if hooks are not active. */ 431 if (inet6_pfil_hook.ph_busy_count == -1) 432 goto passin; 433 434 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 435 return; 436 if (m == NULL) /* consumed by filter */ 437 return; 438 ip6 = mtod(m, struct ip6_hdr *); 439 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 440 441 passin: 442 /* 443 * Check with the firewall... 444 */ 445 if (ip6_fw_enable && ip6_fw_chk_ptr) { 446 u_short port = 0; 447 /* If ipfw says divert, we have to just drop packet */ 448 /* use port as a dummy argument */ 449 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 450 m_freem(m); 451 m = NULL; 452 } 453 if (!m) 454 return; 455 } 456 457 /* 458 * Multicast check 459 */ 460 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 461 struct in6_multi *in6m = 0; 462 463 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 464 /* 465 * See if we belong to the destination multicast group on the 466 * arrival interface. 467 */ 468 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 469 if (in6m) 470 ours = 1; 471 else if (!ip6_mrouter) { 472 ip6stat.ip6s_notmember++; 473 ip6stat.ip6s_cantforward++; 474 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 475 goto bad; 476 } 477 deliverifp = m->m_pkthdr.rcvif; 478 goto hbhcheck; 479 } 480 481 /* 482 * Unicast check 483 */ 484 if (ip6_forward_rt.ro_rt != NULL && 485 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 486 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 487 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 488 ip6stat.ip6s_forward_cachehit++; 489 else { 490 struct sockaddr_in6 *dst6; 491 492 if (ip6_forward_rt.ro_rt) { 493 /* route is down or destination is different */ 494 ip6stat.ip6s_forward_cachemiss++; 495 RTFREE(ip6_forward_rt.ro_rt); 496 ip6_forward_rt.ro_rt = 0; 497 } 498 499 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 500 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 501 dst6->sin6_len = sizeof(struct sockaddr_in6); 502 dst6->sin6_family = AF_INET6; 503 dst6->sin6_addr = ip6->ip6_dst; 504 505 rtalloc((struct route *)&ip6_forward_rt); 506 } 507 508 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 509 510 /* 511 * Accept the packet if the forwarding interface to the destination 512 * according to the routing table is the loopback interface, 513 * unless the associated route has a gateway. 514 * Note that this approach causes to accept a packet if there is a 515 * route to the loopback interface for the destination of the packet. 516 * But we think it's even useful in some situations, e.g. when using 517 * a special daemon which wants to intercept the packet. 518 * 519 * XXX: some OSes automatically make a cloned route for the destination 520 * of an outgoing packet. If the outgoing interface of the packet 521 * is a loopback one, the kernel would consider the packet to be 522 * accepted, even if we have no such address assinged on the interface. 523 * We check the cloned flag of the route entry to reject such cases, 524 * assuming that route entries for our own addresses are not made by 525 * cloning (it should be true because in6_addloop explicitly installs 526 * the host route). However, we might have to do an explicit check 527 * while it would be less efficient. Or, should we rather install a 528 * reject route for such a case? 529 */ 530 if (ip6_forward_rt.ro_rt && 531 (ip6_forward_rt.ro_rt->rt_flags & 532 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 533 #ifdef RTF_WASCLONED 534 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 535 #endif 536 #ifdef RTF_CLONED 537 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 538 #endif 539 #if 0 540 /* 541 * The check below is redundant since the comparison of 542 * the destination and the key of the rtentry has 543 * already done through looking up the routing table. 544 */ 545 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 546 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 547 #endif 548 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 549 struct in6_ifaddr *ia6 = 550 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 551 552 /* 553 * record address information into m_tag. 554 */ 555 (void)ip6_setdstifaddr(m, ia6); 556 557 /* 558 * packets to a tentative, duplicated, or somehow invalid 559 * address must not be accepted. 560 */ 561 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 562 /* this address is ready */ 563 ours = 1; 564 deliverifp = ia6->ia_ifp; /* correct? */ 565 /* Count the packet in the ip address stats */ 566 ia6->ia_ifa.if_ipackets++; 567 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 568 goto hbhcheck; 569 } else { 570 /* address is not ready, so discard the packet. */ 571 nd6log((LOG_INFO, 572 "ip6_input: packet to an unready address %s->%s\n", 573 ip6_sprintf(&ip6->ip6_src), 574 ip6_sprintf(&ip6->ip6_dst))); 575 576 goto bad; 577 } 578 } 579 580 /* 581 * FAITH (Firewall Aided Internet Translator) 582 */ 583 if (ip6_keepfaith) { 584 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 585 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 586 /* XXX do we need more sanity checks? */ 587 ours = 1; 588 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 589 goto hbhcheck; 590 } 591 } 592 593 /* 594 * Now there is no reason to process the packet if it's not our own 595 * and we're not a router. 596 */ 597 if (!ip6_forwarding) { 598 ip6stat.ip6s_cantforward++; 599 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 600 goto bad; 601 } 602 603 hbhcheck: 604 /* 605 * record address information into m_tag, if we don't have one yet. 606 * note that we are unable to record it, if the address is not listed 607 * as our interface address (e.g. multicast addresses, addresses 608 * within FAITH prefixes and such). 609 */ 610 if (deliverifp && !ip6_getdstifaddr(m)) { 611 struct in6_ifaddr *ia6; 612 613 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 614 if (ia6) { 615 if (!ip6_setdstifaddr(m, ia6)) { 616 /* 617 * XXX maybe we should drop the packet here, 618 * as we could not provide enough information 619 * to the upper layers. 620 */ 621 } 622 } 623 } 624 625 /* 626 * Process Hop-by-Hop options header if it's contained. 627 * m may be modified in ip6_hopopts_input(). 628 * If a JumboPayload option is included, plen will also be modified. 629 */ 630 plen = (u_int32_t)ntohs(ip6->ip6_plen); 631 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 632 struct ip6_hbh *hbh; 633 634 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 635 #if 0 /*touches NULL pointer*/ 636 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 637 #endif 638 return; /* m have already been freed */ 639 } 640 641 /* adjust pointer */ 642 ip6 = mtod(m, struct ip6_hdr *); 643 644 /* 645 * if the payload length field is 0 and the next header field 646 * indicates Hop-by-Hop Options header, then a Jumbo Payload 647 * option MUST be included. 648 */ 649 if (ip6->ip6_plen == 0 && plen == 0) { 650 /* 651 * Note that if a valid jumbo payload option is 652 * contained, ip6_hopopts_input() must set a valid 653 * (non-zero) payload length to the variable plen. 654 */ 655 ip6stat.ip6s_badoptions++; 656 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 657 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 658 icmp6_error(m, ICMP6_PARAM_PROB, 659 ICMP6_PARAMPROB_HEADER, 660 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 661 return; 662 } 663 #ifndef PULLDOWN_TEST 664 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 665 hbh = (struct ip6_hbh *)(ip6 + 1); 666 #else 667 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 668 sizeof(struct ip6_hbh)); 669 if (hbh == NULL) { 670 ip6stat.ip6s_tooshort++; 671 return; 672 } 673 #endif 674 nxt = hbh->ip6h_nxt; 675 676 /* 677 * accept the packet if a router alert option is included 678 * and we act as an IPv6 router. 679 */ 680 if (rtalert != ~0 && ip6_forwarding) 681 ours = 1; 682 } else 683 nxt = ip6->ip6_nxt; 684 685 /* 686 * Check that the amount of data in the buffers 687 * is as at least much as the IPv6 header would have us expect. 688 * Trim mbufs if longer than we expect. 689 * Drop packet if shorter than we expect. 690 */ 691 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 692 ip6stat.ip6s_tooshort++; 693 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 694 goto bad; 695 } 696 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 697 if (m->m_len == m->m_pkthdr.len) { 698 m->m_len = sizeof(struct ip6_hdr) + plen; 699 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 700 } else 701 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 702 } 703 704 /* 705 * Forward if desirable. 706 */ 707 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 708 /* 709 * If we are acting as a multicast router, all 710 * incoming multicast packets are passed to the 711 * kernel-level multicast forwarding function. 712 * The packet is returned (relatively) intact; if 713 * ip6_mforward() returns a non-zero value, the packet 714 * must be discarded, else it may be accepted below. 715 */ 716 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 717 ip6stat.ip6s_cantforward++; 718 m_freem(m); 719 return; 720 } 721 if (!ours) { 722 m_freem(m); 723 return; 724 } 725 } else if (!ours) { 726 ip6_forward(m, srcrt); 727 return; 728 } 729 730 ip6 = mtod(m, struct ip6_hdr *); 731 732 /* 733 * Malicious party may be able to use IPv4 mapped addr to confuse 734 * tcp/udp stack and bypass security checks (act as if it was from 735 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 736 * 737 * For SIIT end node behavior, you may want to disable the check. 738 * However, you will become vulnerable to attacks using IPv4 mapped 739 * source. 740 */ 741 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 742 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 743 ip6stat.ip6s_badscope++; 744 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 745 goto bad; 746 } 747 748 /* 749 * Tell launch routine the next header 750 */ 751 ip6stat.ip6s_delivered++; 752 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 753 nest = 0; 754 755 while (nxt != IPPROTO_DONE) { 756 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 757 ip6stat.ip6s_toomanyhdr++; 758 goto bad; 759 } 760 761 /* 762 * protection against faulty packet - there should be 763 * more sanity checks in header chain processing. 764 */ 765 if (m->m_pkthdr.len < off) { 766 ip6stat.ip6s_tooshort++; 767 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 768 goto bad; 769 } 770 771 #ifdef IPSEC 772 /* 773 * enforce IPsec policy checking if we are seeing last header. 774 * note that we do not visit this with protocols with pcb layer 775 * code - like udp/tcp/raw ip. 776 */ 777 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 778 ipsec6_in_reject(m, NULL)) { 779 ipsec6stat.in_polvio++; 780 goto bad; 781 } 782 #endif 783 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 784 } 785 return; 786 bad: 787 m_freem(m); 788 } 789 790 /* 791 * set/grab in6_ifaddr correspond to IPv6 destination address. 792 * XXX backward compatibility wrapper 793 */ 794 static struct ip6aux * 795 ip6_setdstifaddr(m, ia6) 796 struct mbuf *m; 797 struct in6_ifaddr *ia6; 798 { 799 struct ip6aux *ip6a; 800 801 ip6a = ip6_addaux(m); 802 if (ip6a) 803 ip6a->ip6a_dstia6 = ia6; 804 return ip6a; /* NULL if failed to set */ 805 } 806 807 struct in6_ifaddr * 808 ip6_getdstifaddr(m) 809 struct mbuf *m; 810 { 811 struct ip6aux *ip6a; 812 813 ip6a = ip6_findaux(m); 814 if (ip6a) 815 return ip6a->ip6a_dstia6; 816 else 817 return NULL; 818 } 819 820 /* 821 * Hop-by-Hop options header processing. If a valid jumbo payload option is 822 * included, the real payload length will be stored in plenp. 823 */ 824 static int 825 ip6_hopopts_input(plenp, rtalertp, mp, offp) 826 u_int32_t *plenp; 827 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 828 struct mbuf **mp; 829 int *offp; 830 { 831 struct mbuf *m = *mp; 832 int off = *offp, hbhlen; 833 struct ip6_hbh *hbh; 834 u_int8_t *opt; 835 836 /* validation of the length of the header */ 837 #ifndef PULLDOWN_TEST 838 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 839 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 840 hbhlen = (hbh->ip6h_len + 1) << 3; 841 842 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 843 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 844 #else 845 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 846 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 847 if (hbh == NULL) { 848 ip6stat.ip6s_tooshort++; 849 return -1; 850 } 851 hbhlen = (hbh->ip6h_len + 1) << 3; 852 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 853 hbhlen); 854 if (hbh == NULL) { 855 ip6stat.ip6s_tooshort++; 856 return -1; 857 } 858 #endif 859 off += hbhlen; 860 hbhlen -= sizeof(struct ip6_hbh); 861 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 862 863 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 864 hbhlen, rtalertp, plenp) < 0) 865 return (-1); 866 867 *offp = off; 868 *mp = m; 869 return (0); 870 } 871 872 /* 873 * Search header for all Hop-by-hop options and process each option. 874 * This function is separate from ip6_hopopts_input() in order to 875 * handle a case where the sending node itself process its hop-by-hop 876 * options header. In such a case, the function is called from ip6_output(). 877 * 878 * The function assumes that hbh header is located right after the IPv6 header 879 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 880 * opthead + hbhlen is located in continuous memory region. 881 */ 882 int 883 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 884 struct mbuf *m; 885 u_int8_t *opthead; 886 int hbhlen; 887 u_int32_t *rtalertp; 888 u_int32_t *plenp; 889 { 890 struct ip6_hdr *ip6; 891 int optlen = 0; 892 u_int8_t *opt = opthead; 893 u_int16_t rtalert_val; 894 u_int32_t jumboplen; 895 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 896 897 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 898 switch (*opt) { 899 case IP6OPT_PAD1: 900 optlen = 1; 901 break; 902 case IP6OPT_PADN: 903 if (hbhlen < IP6OPT_MINLEN) { 904 ip6stat.ip6s_toosmall++; 905 goto bad; 906 } 907 optlen = *(opt + 1) + 2; 908 break; 909 case IP6OPT_ROUTER_ALERT: 910 /* XXX may need check for alignment */ 911 if (hbhlen < IP6OPT_RTALERT_LEN) { 912 ip6stat.ip6s_toosmall++; 913 goto bad; 914 } 915 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 916 /* XXX stat */ 917 icmp6_error(m, ICMP6_PARAM_PROB, 918 ICMP6_PARAMPROB_HEADER, 919 erroff + opt + 1 - opthead); 920 return (-1); 921 } 922 optlen = IP6OPT_RTALERT_LEN; 923 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 924 *rtalertp = ntohs(rtalert_val); 925 break; 926 case IP6OPT_JUMBO: 927 /* XXX may need check for alignment */ 928 if (hbhlen < IP6OPT_JUMBO_LEN) { 929 ip6stat.ip6s_toosmall++; 930 goto bad; 931 } 932 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 933 /* XXX stat */ 934 icmp6_error(m, ICMP6_PARAM_PROB, 935 ICMP6_PARAMPROB_HEADER, 936 erroff + opt + 1 - opthead); 937 return (-1); 938 } 939 optlen = IP6OPT_JUMBO_LEN; 940 941 /* 942 * IPv6 packets that have non 0 payload length 943 * must not contain a jumbo payload option. 944 */ 945 ip6 = mtod(m, struct ip6_hdr *); 946 if (ip6->ip6_plen) { 947 ip6stat.ip6s_badoptions++; 948 icmp6_error(m, ICMP6_PARAM_PROB, 949 ICMP6_PARAMPROB_HEADER, 950 erroff + opt - opthead); 951 return (-1); 952 } 953 954 /* 955 * We may see jumbolen in unaligned location, so 956 * we'd need to perform bcopy(). 957 */ 958 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 959 jumboplen = (u_int32_t)htonl(jumboplen); 960 961 #if 1 962 /* 963 * if there are multiple jumbo payload options, 964 * *plenp will be non-zero and the packet will be 965 * rejected. 966 * the behavior may need some debate in ipngwg - 967 * multiple options does not make sense, however, 968 * there's no explicit mention in specification. 969 */ 970 if (*plenp != 0) { 971 ip6stat.ip6s_badoptions++; 972 icmp6_error(m, ICMP6_PARAM_PROB, 973 ICMP6_PARAMPROB_HEADER, 974 erroff + opt + 2 - opthead); 975 return (-1); 976 } 977 #endif 978 979 /* 980 * jumbo payload length must be larger than 65535. 981 */ 982 if (jumboplen <= IPV6_MAXPACKET) { 983 ip6stat.ip6s_badoptions++; 984 icmp6_error(m, ICMP6_PARAM_PROB, 985 ICMP6_PARAMPROB_HEADER, 986 erroff + opt + 2 - opthead); 987 return (-1); 988 } 989 *plenp = jumboplen; 990 991 break; 992 default: /* unknown option */ 993 if (hbhlen < IP6OPT_MINLEN) { 994 ip6stat.ip6s_toosmall++; 995 goto bad; 996 } 997 optlen = ip6_unknown_opt(opt, m, 998 erroff + opt - opthead); 999 if (optlen == -1) 1000 return (-1); 1001 optlen += 2; 1002 break; 1003 } 1004 } 1005 1006 return (0); 1007 1008 bad: 1009 m_freem(m); 1010 return (-1); 1011 } 1012 1013 /* 1014 * Unknown option processing. 1015 * The third argument `off' is the offset from the IPv6 header to the option, 1016 * which is necessary if the IPv6 header the and option header and IPv6 header 1017 * is not continuous in order to return an ICMPv6 error. 1018 */ 1019 int 1020 ip6_unknown_opt(optp, m, off) 1021 u_int8_t *optp; 1022 struct mbuf *m; 1023 int off; 1024 { 1025 struct ip6_hdr *ip6; 1026 1027 switch (IP6OPT_TYPE(*optp)) { 1028 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1029 return ((int)*(optp + 1)); 1030 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1031 m_freem(m); 1032 return (-1); 1033 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1034 ip6stat.ip6s_badoptions++; 1035 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1036 return (-1); 1037 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1038 ip6stat.ip6s_badoptions++; 1039 ip6 = mtod(m, struct ip6_hdr *); 1040 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1041 (m->m_flags & (M_BCAST|M_MCAST))) 1042 m_freem(m); 1043 else 1044 icmp6_error(m, ICMP6_PARAM_PROB, 1045 ICMP6_PARAMPROB_OPTION, off); 1046 return (-1); 1047 } 1048 1049 m_freem(m); /* XXX: NOTREACHED */ 1050 return (-1); 1051 } 1052 1053 /* 1054 * Create the "control" list for this pcb. 1055 * The function will not modify mbuf chain at all. 1056 * 1057 * with KAME mbuf chain restriction: 1058 * The routine will be called from upper layer handlers like tcp6_input(). 1059 * Thus the routine assumes that the caller (tcp6_input) have already 1060 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1061 * very first mbuf on the mbuf chain. 1062 */ 1063 void 1064 ip6_savecontrol(in6p, m, mp) 1065 struct inpcb *in6p; 1066 struct mbuf *m, **mp; 1067 { 1068 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1069 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 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. Recall that we required super-user 1127 * privilege for the option (see ip6_ctloutput), but it might be too 1128 * strict, since there might be some hop-by-hop options which can be 1129 * returned to normal user. 1130 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1131 */ 1132 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1133 /* 1134 * Check if a hop-by-hop options header is contatined in the 1135 * received packet, and if so, store the options as ancillary 1136 * data. Note that a hop-by-hop options header must be 1137 * just after the IPv6 header, which is assured through the 1138 * IPv6 input processing. 1139 */ 1140 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1141 struct ip6_hbh *hbh; 1142 int hbhlen = 0; 1143 #ifdef PULLDOWN_TEST 1144 struct mbuf *ext; 1145 #endif 1146 1147 #ifndef PULLDOWN_TEST 1148 hbh = (struct ip6_hbh *)(ip6 + 1); 1149 hbhlen = (hbh->ip6h_len + 1) << 3; 1150 #else 1151 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1152 ip6->ip6_nxt); 1153 if (ext == NULL) { 1154 ip6stat.ip6s_tooshort++; 1155 return; 1156 } 1157 hbh = mtod(ext, struct ip6_hbh *); 1158 hbhlen = (hbh->ip6h_len + 1) << 3; 1159 if (hbhlen != ext->m_len) { 1160 m_freem(ext); 1161 ip6stat.ip6s_tooshort++; 1162 return; 1163 } 1164 #endif 1165 1166 /* 1167 * XXX: We copy the whole header even if a 1168 * jumbo payload option is included, the option which 1169 * is to be removed before returning according to 1170 * RFC2292. 1171 * Note: this constraint is removed in RFC3542 1172 */ 1173 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1174 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1175 IPPROTO_IPV6); 1176 if (*mp) 1177 mp = &(*mp)->m_next; 1178 #ifdef PULLDOWN_TEST 1179 m_freem(ext); 1180 #endif 1181 } 1182 } 1183 1184 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1185 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1186 1187 /* 1188 * Search for destination options headers or routing 1189 * header(s) through the header chain, and stores each 1190 * header as ancillary data. 1191 * Note that the order of the headers remains in 1192 * the chain of ancillary data. 1193 */ 1194 while (1) { /* is explicit loop prevention necessary? */ 1195 struct ip6_ext *ip6e = NULL; 1196 int elen; 1197 #ifdef PULLDOWN_TEST 1198 struct mbuf *ext = NULL; 1199 #endif 1200 1201 /* 1202 * if it is not an extension header, don't try to 1203 * pull it from the chain. 1204 */ 1205 switch (nxt) { 1206 case IPPROTO_DSTOPTS: 1207 case IPPROTO_ROUTING: 1208 case IPPROTO_HOPOPTS: 1209 case IPPROTO_AH: /* is it possible? */ 1210 break; 1211 default: 1212 goto loopend; 1213 } 1214 1215 #ifndef PULLDOWN_TEST 1216 if (off + sizeof(*ip6e) > m->m_len) 1217 goto loopend; 1218 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1219 if (nxt == IPPROTO_AH) 1220 elen = (ip6e->ip6e_len + 2) << 2; 1221 else 1222 elen = (ip6e->ip6e_len + 1) << 3; 1223 if (off + elen > m->m_len) 1224 goto loopend; 1225 #else 1226 ext = ip6_pullexthdr(m, off, nxt); 1227 if (ext == NULL) { 1228 ip6stat.ip6s_tooshort++; 1229 return; 1230 } 1231 ip6e = mtod(ext, struct ip6_ext *); 1232 if (nxt == IPPROTO_AH) 1233 elen = (ip6e->ip6e_len + 2) << 2; 1234 else 1235 elen = (ip6e->ip6e_len + 1) << 3; 1236 if (elen != ext->m_len) { 1237 m_freem(ext); 1238 ip6stat.ip6s_tooshort++; 1239 return; 1240 } 1241 #endif 1242 1243 switch (nxt) { 1244 case IPPROTO_DSTOPTS: 1245 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1246 break; 1247 1248 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1249 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1250 IPPROTO_IPV6); 1251 if (*mp) 1252 mp = &(*mp)->m_next; 1253 break; 1254 case IPPROTO_ROUTING: 1255 if (!in6p->in6p_flags & IN6P_RTHDR) 1256 break; 1257 1258 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1259 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1260 IPPROTO_IPV6); 1261 if (*mp) 1262 mp = &(*mp)->m_next; 1263 break; 1264 case IPPROTO_HOPOPTS: 1265 case IPPROTO_AH: /* is it possible? */ 1266 break; 1267 1268 default: 1269 /* 1270 * other cases have been filtered in the above. 1271 * none will visit this case. here we supply 1272 * the code just in case (nxt overwritten or 1273 * other cases). 1274 */ 1275 #ifdef PULLDOWN_TEST 1276 m_freem(ext); 1277 #endif 1278 goto loopend; 1279 1280 } 1281 1282 /* proceed with the next header. */ 1283 off += elen; 1284 nxt = ip6e->ip6e_nxt; 1285 ip6e = NULL; 1286 #ifdef PULLDOWN_TEST 1287 m_freem(ext); 1288 ext = NULL; 1289 #endif 1290 } 1291 loopend: 1292 ; 1293 } 1294 1295 #undef IS2292 1296 } 1297 1298 void 1299 ip6_notify_pmtu(in6p, dst, mtu) 1300 struct inpcb *in6p; 1301 struct sockaddr_in6 *dst; 1302 u_int32_t *mtu; 1303 { 1304 struct socket *so; 1305 struct mbuf *m_mtu; 1306 struct ip6_mtuinfo mtuctl; 1307 1308 so = in6p->inp_socket; 1309 1310 if (mtu == NULL) 1311 return; 1312 1313 #ifdef DIAGNOSTIC 1314 if (so == NULL) /* I believe this is impossible */ 1315 panic("ip6_notify_pmtu: socket is NULL"); 1316 #endif 1317 1318 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1319 mtuctl.ip6m_mtu = *mtu; 1320 mtuctl.ip6m_addr = *dst; 1321 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1322 return; 1323 1324 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1325 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1326 return; 1327 1328 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1329 == 0) { 1330 m_freem(m_mtu); 1331 /* XXX: should count statistics */ 1332 } else 1333 sorwakeup(so); 1334 1335 return; 1336 } 1337 1338 #ifdef PULLDOWN_TEST 1339 /* 1340 * pull single extension header from mbuf chain. returns single mbuf that 1341 * contains the result, or NULL on error. 1342 */ 1343 static struct mbuf * 1344 ip6_pullexthdr(m, off, nxt) 1345 struct mbuf *m; 1346 size_t off; 1347 int nxt; 1348 { 1349 struct ip6_ext ip6e; 1350 size_t elen; 1351 struct mbuf *n; 1352 1353 #ifdef DIAGNOSTIC 1354 switch (nxt) { 1355 case IPPROTO_DSTOPTS: 1356 case IPPROTO_ROUTING: 1357 case IPPROTO_HOPOPTS: 1358 case IPPROTO_AH: /* is it possible? */ 1359 break; 1360 default: 1361 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1362 } 1363 #endif 1364 1365 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1366 if (nxt == IPPROTO_AH) 1367 elen = (ip6e.ip6e_len + 2) << 2; 1368 else 1369 elen = (ip6e.ip6e_len + 1) << 3; 1370 1371 MGET(n, M_DONTWAIT, MT_DATA); 1372 if (n && elen >= MLEN) { 1373 MCLGET(n, M_DONTWAIT); 1374 if ((n->m_flags & M_EXT) == 0) { 1375 m_free(n); 1376 n = NULL; 1377 } 1378 } 1379 if (!n) 1380 return NULL; 1381 1382 n->m_len = 0; 1383 if (elen >= M_TRAILINGSPACE(n)) { 1384 m_free(n); 1385 return NULL; 1386 } 1387 1388 m_copydata(m, off, elen, mtod(n, caddr_t)); 1389 n->m_len = elen; 1390 return n; 1391 } 1392 #endif 1393 1394 /* 1395 * Get pointer to the previous header followed by the header 1396 * currently processed. 1397 * XXX: This function supposes that 1398 * M includes all headers, 1399 * the next header field and the header length field of each header 1400 * are valid, and 1401 * the sum of each header length equals to OFF. 1402 * Because of these assumptions, this function must be called very 1403 * carefully. Moreover, it will not be used in the near future when 1404 * we develop `neater' mechanism to process extension headers. 1405 */ 1406 char * 1407 ip6_get_prevhdr(m, off) 1408 struct mbuf *m; 1409 int off; 1410 { 1411 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1412 1413 if (off == sizeof(struct ip6_hdr)) 1414 return (&ip6->ip6_nxt); 1415 else { 1416 int len, nxt; 1417 struct ip6_ext *ip6e = NULL; 1418 1419 nxt = ip6->ip6_nxt; 1420 len = sizeof(struct ip6_hdr); 1421 while (len < off) { 1422 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1423 1424 switch (nxt) { 1425 case IPPROTO_FRAGMENT: 1426 len += sizeof(struct ip6_frag); 1427 break; 1428 case IPPROTO_AH: 1429 len += (ip6e->ip6e_len + 2) << 2; 1430 break; 1431 default: 1432 len += (ip6e->ip6e_len + 1) << 3; 1433 break; 1434 } 1435 nxt = ip6e->ip6e_nxt; 1436 } 1437 if (ip6e) 1438 return (&ip6e->ip6e_nxt); 1439 else 1440 return NULL; 1441 } 1442 } 1443 1444 /* 1445 * get next header offset. m will be retained. 1446 */ 1447 int 1448 ip6_nexthdr(m, off, proto, nxtp) 1449 struct mbuf *m; 1450 int off; 1451 int proto; 1452 int *nxtp; 1453 { 1454 struct ip6_hdr ip6; 1455 struct ip6_ext ip6e; 1456 struct ip6_frag fh; 1457 1458 /* just in case */ 1459 if (m == NULL) 1460 panic("ip6_nexthdr: m == NULL"); 1461 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1462 return -1; 1463 1464 switch (proto) { 1465 case IPPROTO_IPV6: 1466 if (m->m_pkthdr.len < off + sizeof(ip6)) 1467 return -1; 1468 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1469 if (nxtp) 1470 *nxtp = ip6.ip6_nxt; 1471 off += sizeof(ip6); 1472 return off; 1473 1474 case IPPROTO_FRAGMENT: 1475 /* 1476 * terminate parsing if it is not the first fragment, 1477 * it does not make sense to parse through it. 1478 */ 1479 if (m->m_pkthdr.len < off + sizeof(fh)) 1480 return -1; 1481 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1482 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1483 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1484 return -1; 1485 if (nxtp) 1486 *nxtp = fh.ip6f_nxt; 1487 off += sizeof(struct ip6_frag); 1488 return off; 1489 1490 case IPPROTO_AH: 1491 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1492 return -1; 1493 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1494 if (nxtp) 1495 *nxtp = ip6e.ip6e_nxt; 1496 off += (ip6e.ip6e_len + 2) << 2; 1497 return off; 1498 1499 case IPPROTO_HOPOPTS: 1500 case IPPROTO_ROUTING: 1501 case IPPROTO_DSTOPTS: 1502 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1503 return -1; 1504 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1505 if (nxtp) 1506 *nxtp = ip6e.ip6e_nxt; 1507 off += (ip6e.ip6e_len + 1) << 3; 1508 return off; 1509 1510 case IPPROTO_NONE: 1511 case IPPROTO_ESP: 1512 case IPPROTO_IPCOMP: 1513 /* give up */ 1514 return -1; 1515 1516 default: 1517 return -1; 1518 } 1519 1520 return -1; 1521 } 1522 1523 /* 1524 * get offset for the last header in the chain. m will be kept untainted. 1525 */ 1526 int 1527 ip6_lasthdr(m, off, proto, nxtp) 1528 struct mbuf *m; 1529 int off; 1530 int proto; 1531 int *nxtp; 1532 { 1533 int newoff; 1534 int nxt; 1535 1536 if (!nxtp) { 1537 nxt = -1; 1538 nxtp = &nxt; 1539 } 1540 while (1) { 1541 newoff = ip6_nexthdr(m, off, proto, nxtp); 1542 if (newoff < 0) 1543 return off; 1544 else if (newoff < off) 1545 return -1; /* invalid */ 1546 else if (newoff == off) 1547 return newoff; 1548 1549 off = newoff; 1550 proto = *nxtp; 1551 } 1552 } 1553 1554 struct ip6aux * 1555 ip6_addaux(m) 1556 struct mbuf *m; 1557 { 1558 struct m_tag *mtag; 1559 1560 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1561 if (!mtag) { 1562 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1563 M_NOWAIT); 1564 if (mtag) { 1565 m_tag_prepend(m, mtag); 1566 bzero(mtag + 1, sizeof(struct ip6aux)); 1567 } 1568 } 1569 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1570 } 1571 1572 struct ip6aux * 1573 ip6_findaux(m) 1574 struct mbuf *m; 1575 { 1576 struct m_tag *mtag; 1577 1578 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1579 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1580 } 1581 1582 void 1583 ip6_delaux(m) 1584 struct mbuf *m; 1585 { 1586 struct m_tag *mtag; 1587 1588 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1589 if (mtag) 1590 m_tag_delete(m, mtag); 1591 } 1592 1593 /* 1594 * System control for IP6 1595 */ 1596 1597 u_char inet6ctlerrmap[PRC_NCMDS] = { 1598 0, 0, 0, 0, 1599 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1600 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1601 EMSGSIZE, EHOSTUNREACH, 0, 0, 1602 0, 0, 0, 0, 1603 ENOPROTOOPT 1604 }; 1605