Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/netinet6/ip6_input.c
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1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1988, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include "opt_ip6fw.h" 67 #include "opt_inet.h" 68 #include "opt_inet6.h" 69 #include "opt_ipsec.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 #include <net/pfil.h> 91 92 #include <netinet/in.h> 93 #include <netinet/in_systm.h> 94 #ifdef INET 95 #include <netinet/ip.h> 96 #include <netinet/ip_icmp.h> 97 #endif /* INET */ 98 #include <netinet/ip6.h> 99 #include <netinet6/in6_var.h> 100 #include <netinet6/ip6_var.h> 101 #include <netinet/in_pcb.h> 102 #include <netinet/icmp6.h> 103 #include <netinet6/scope6_var.h> 104 #include <netinet6/in6_ifattach.h> 105 #include <netinet6/nd6.h> 106 107 #ifdef IPSEC 108 #include <netinet6/ipsec.h> 109 #ifdef INET6 110 #include <netinet6/ipsec6.h> 111 #endif 112 #endif 113 114 #ifdef FAST_IPSEC 115 #include <netipsec/ipsec.h> 116 #include <netipsec/ipsec6.h> 117 #define IPSEC 118 #endif /* FAST_IPSEC */ 119 120 #include <netinet6/ip6_fw.h> 121 122 #include <netinet6/ip6protosw.h> 123 124 #include <net/net_osdep.h> 125 126 extern struct domain inet6domain; 127 128 u_char ip6_protox[IPPROTO_MAX]; 129 static struct ifqueue ip6intrq; 130 static int ip6qmaxlen = IFQ_MAXLEN; 131 struct in6_ifaddr *in6_ifaddr; 132 133 extern struct callout in6_tmpaddrtimer_ch; 134 135 int ip6_forward_srcrt; /* XXX */ 136 int ip6_sourcecheck; /* XXX */ 137 int ip6_sourcecheck_interval; /* XXX */ 138 139 int ip6_ours_check_algorithm; 140 141 struct pfil_head inet6_pfil_hook; 142 143 /* firewall hooks */ 144 ip6_fw_chk_t *ip6_fw_chk_ptr; 145 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 146 int ip6_fw_enable = 1; 147 148 struct ip6stat ip6stat; 149 150 static void ip6_init2(void *); 151 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 152 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 153 #ifdef PULLDOWN_TEST 154 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 155 #endif 156 157 /* 158 * IP6 initialization: fill in IP6 protocol switch table. 159 * All protocols not implemented in kernel go to raw IP6 protocol handler. 160 */ 161 void 162 ip6_init() 163 { 164 struct ip6protosw *pr; 165 int i; 166 167 #ifdef DIAGNOSTIC 168 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 169 panic("sizeof(protosw) != sizeof(ip6protosw)"); 170 #endif 171 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 172 if (pr == 0) 173 panic("ip6_init"); 174 175 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 176 for (i = 0; i < IPPROTO_MAX; i++) 177 ip6_protox[i] = pr - inet6sw; 178 /* 179 * Cycle through IP protocols and put them into the appropriate place 180 * in ip6_protox[]. 181 */ 182 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 183 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 184 if (pr->pr_domain->dom_family == PF_INET6 && 185 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 186 /* Be careful to only index valid IP protocols. */ 187 if (pr->pr_protocol < IPPROTO_MAX) 188 ip6_protox[pr->pr_protocol] = pr - inet6sw; 189 } 190 191 /* Initialize packet filter hooks. */ 192 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 193 inet6_pfil_hook.ph_af = AF_INET6; 194 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 195 printf("%s: WARNING: unable to register pfil hook, " 196 "error %d\n", __func__, i); 197 198 ip6intrq.ifq_maxlen = ip6qmaxlen; 199 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 200 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 201 scope6_init(); 202 addrsel_policy_init(); 203 nd6_init(); 204 frag6_init(); 205 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 206 } 207 208 static void 209 ip6_init2(dummy) 210 void *dummy; 211 { 212 213 /* nd6_timer_init */ 214 callout_init(&nd6_timer_ch, 0); 215 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 216 217 /* timer for regeneranation of temporary addresses randomize ID */ 218 callout_init(&in6_tmpaddrtimer_ch, 0); 219 callout_reset(&in6_tmpaddrtimer_ch, 220 (ip6_temp_preferred_lifetime - ip6_desync_factor - 221 ip6_temp_regen_advance) * hz, 222 in6_tmpaddrtimer, NULL); 223 } 224 225 /* cheat */ 226 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 227 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 228 229 extern struct route_in6 ip6_forward_rt; 230 231 void 232 ip6_input(m) 233 struct mbuf *m; 234 { 235 struct ip6_hdr *ip6; 236 int off = sizeof(struct ip6_hdr), nest; 237 u_int32_t plen; 238 u_int32_t rtalert = ~0; 239 int nxt, ours = 0; 240 struct ifnet *deliverifp = NULL; 241 struct in6_addr odst; 242 int srcrt = 0; 243 244 GIANT_REQUIRED; /* XXX for now */ 245 #ifdef IPSEC 246 /* 247 * should the inner packet be considered authentic? 248 * see comment in ah4_input(). 249 */ 250 if (m) { 251 m->m_flags &= ~M_AUTHIPHDR; 252 m->m_flags &= ~M_AUTHIPDGM; 253 } 254 #endif 255 256 /* 257 * make sure we don't have onion peering information into m_tag. 258 */ 259 ip6_delaux(m); 260 261 /* 262 * mbuf statistics 263 */ 264 if (m->m_flags & M_EXT) { 265 if (m->m_next) 266 ip6stat.ip6s_mext2m++; 267 else 268 ip6stat.ip6s_mext1++; 269 } else { 270 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 271 if (m->m_next) { 272 if (m->m_flags & M_LOOP) { 273 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 274 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 275 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 276 else 277 ip6stat.ip6s_m2m[0]++; 278 } else 279 ip6stat.ip6s_m1++; 280 #undef M2MMAX 281 } 282 283 /* drop the packet if IPv6 operation is disabled on the IF */ 284 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 285 m_freem(m); 286 return; 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 * Run through list of hooks for input packets. 411 * 412 * NB: Beware of the destination address changing 413 * (e.g. by NAT rewriting). When this happens, 414 * tell ip6_forward to do the right thing. 415 */ 416 odst = ip6->ip6_dst; 417 418 /* Jump over all PFIL processing if hooks are not active. */ 419 if (inet6_pfil_hook.ph_busy_count == -1) 420 goto passin; 421 422 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 423 return; 424 if (m == NULL) /* consumed by filter */ 425 return; 426 ip6 = mtod(m, struct ip6_hdr *); 427 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 428 429 passin: 430 /* 431 * Check with the firewall... 432 */ 433 if (ip6_fw_enable && ip6_fw_chk_ptr) { 434 u_short port = 0; 435 /* If ipfw says divert, we have to just drop packet */ 436 /* use port as a dummy argument */ 437 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 438 m_freem(m); 439 m = NULL; 440 } 441 if (!m) 442 return; 443 } 444 445 /* 446 * Disambiguate address scope zones (if there is ambiguity). 447 * We first make sure that the original source or destination address 448 * is not in our internal form for scoped addresses. Such addresses 449 * are not necessarily invalid spec-wise, but we cannot accept them due 450 * to the usage conflict. 451 * in6_setscope() then also checks and rejects the cases where src or 452 * dst are the loopback address and the receiving interface 453 * is not loopback. 454 */ 455 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 456 ip6stat.ip6s_badscope++; /* XXX */ 457 goto bad; 458 } 459 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 460 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 461 ip6stat.ip6s_badscope++; 462 goto bad; 463 } 464 465 /* 466 * Multicast check 467 */ 468 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 469 struct in6_multi *in6m = 0; 470 471 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 472 /* 473 * See if we belong to the destination multicast group on the 474 * arrival interface. 475 */ 476 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 477 if (in6m) 478 ours = 1; 479 else if (!ip6_mrouter) { 480 ip6stat.ip6s_notmember++; 481 ip6stat.ip6s_cantforward++; 482 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 483 goto bad; 484 } 485 deliverifp = m->m_pkthdr.rcvif; 486 goto hbhcheck; 487 } 488 489 /* 490 * Unicast check 491 */ 492 if (ip6_forward_rt.ro_rt != NULL && 493 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 494 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 495 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 496 ip6stat.ip6s_forward_cachehit++; 497 else { 498 struct sockaddr_in6 *dst6; 499 500 if (ip6_forward_rt.ro_rt) { 501 /* route is down or destination is different */ 502 ip6stat.ip6s_forward_cachemiss++; 503 RTFREE(ip6_forward_rt.ro_rt); 504 ip6_forward_rt.ro_rt = 0; 505 } 506 507 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 508 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 509 dst6->sin6_len = sizeof(struct sockaddr_in6); 510 dst6->sin6_family = AF_INET6; 511 dst6->sin6_addr = ip6->ip6_dst; 512 513 rtalloc((struct route *)&ip6_forward_rt); 514 } 515 516 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 517 518 /* 519 * Accept the packet if the forwarding interface to the destination 520 * according to the routing table is the loopback interface, 521 * unless the associated route has a gateway. 522 * Note that this approach causes to accept a packet if there is a 523 * route to the loopback interface for the destination of the packet. 524 * But we think it's even useful in some situations, e.g. when using 525 * a special daemon which wants to intercept the packet. 526 * 527 * XXX: some OSes automatically make a cloned route for the destination 528 * of an outgoing packet. If the outgoing interface of the packet 529 * is a loopback one, the kernel would consider the packet to be 530 * accepted, even if we have no such address assinged on the interface. 531 * We check the cloned flag of the route entry to reject such cases, 532 * assuming that route entries for our own addresses are not made by 533 * cloning (it should be true because in6_addloop explicitly installs 534 * the host route). However, we might have to do an explicit check 535 * while it would be less efficient. Or, should we rather install a 536 * reject route for such a case? 537 */ 538 if (ip6_forward_rt.ro_rt && 539 (ip6_forward_rt.ro_rt->rt_flags & 540 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 541 #ifdef RTF_WASCLONED 542 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 543 #endif 544 #ifdef RTF_CLONED 545 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 546 #endif 547 #if 0 548 /* 549 * The check below is redundant since the comparison of 550 * the destination and the key of the rtentry has 551 * already done through looking up the routing table. 552 */ 553 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 554 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 555 #endif 556 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 557 struct in6_ifaddr *ia6 = 558 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 559 560 /* 561 * record address information into m_tag. 562 */ 563 (void)ip6_setdstifaddr(m, ia6); 564 565 /* 566 * packets to a tentative, duplicated, or somehow invalid 567 * address must not be accepted. 568 */ 569 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 570 /* this address is ready */ 571 ours = 1; 572 deliverifp = ia6->ia_ifp; /* correct? */ 573 /* Count the packet in the ip address stats */ 574 ia6->ia_ifa.if_ipackets++; 575 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 576 goto hbhcheck; 577 } else { 578 /* address is not ready, so discard the packet. */ 579 nd6log((LOG_INFO, 580 "ip6_input: packet to an unready address %s->%s\n", 581 ip6_sprintf(&ip6->ip6_src), 582 ip6_sprintf(&ip6->ip6_dst))); 583 584 goto bad; 585 } 586 } 587 588 /* 589 * FAITH (Firewall Aided Internet Translator) 590 */ 591 if (ip6_keepfaith) { 592 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 593 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 594 /* XXX do we need more sanity checks? */ 595 ours = 1; 596 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 597 goto hbhcheck; 598 } 599 } 600 601 /* 602 * Now there is no reason to process the packet if it's not our own 603 * and we're not a router. 604 */ 605 if (!ip6_forwarding) { 606 ip6stat.ip6s_cantforward++; 607 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 608 goto bad; 609 } 610 611 hbhcheck: 612 /* 613 * record address information into m_tag, if we don't have one yet. 614 * note that we are unable to record it, if the address is not listed 615 * as our interface address (e.g. multicast addresses, addresses 616 * within FAITH prefixes and such). 617 */ 618 if (deliverifp && !ip6_getdstifaddr(m)) { 619 struct in6_ifaddr *ia6; 620 621 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 622 if (ia6) { 623 if (!ip6_setdstifaddr(m, ia6)) { 624 /* 625 * XXX maybe we should drop the packet here, 626 * as we could not provide enough information 627 * to the upper layers. 628 */ 629 } 630 } 631 } 632 633 /* 634 * Process Hop-by-Hop options header if it's contained. 635 * m may be modified in ip6_hopopts_input(). 636 * If a JumboPayload option is included, plen will also be modified. 637 */ 638 plen = (u_int32_t)ntohs(ip6->ip6_plen); 639 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 640 struct ip6_hbh *hbh; 641 642 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 643 #if 0 /*touches NULL pointer*/ 644 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 645 #endif 646 return; /* m have already been freed */ 647 } 648 649 /* adjust pointer */ 650 ip6 = mtod(m, struct ip6_hdr *); 651 652 /* 653 * if the payload length field is 0 and the next header field 654 * indicates Hop-by-Hop Options header, then a Jumbo Payload 655 * option MUST be included. 656 */ 657 if (ip6->ip6_plen == 0 && plen == 0) { 658 /* 659 * Note that if a valid jumbo payload option is 660 * contained, ip6_hopopts_input() must set a valid 661 * (non-zero) payload length to the variable plen. 662 */ 663 ip6stat.ip6s_badoptions++; 664 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 665 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 666 icmp6_error(m, ICMP6_PARAM_PROB, 667 ICMP6_PARAMPROB_HEADER, 668 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 669 return; 670 } 671 #ifndef PULLDOWN_TEST 672 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 673 hbh = (struct ip6_hbh *)(ip6 + 1); 674 #else 675 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 676 sizeof(struct ip6_hbh)); 677 if (hbh == NULL) { 678 ip6stat.ip6s_tooshort++; 679 return; 680 } 681 #endif 682 nxt = hbh->ip6h_nxt; 683 684 /* 685 * accept the packet if a router alert option is included 686 * and we act as an IPv6 router. 687 */ 688 if (rtalert != ~0 && ip6_forwarding) 689 ours = 1; 690 } else 691 nxt = ip6->ip6_nxt; 692 693 /* 694 * Check that the amount of data in the buffers 695 * is as at least much as the IPv6 header would have us expect. 696 * Trim mbufs if longer than we expect. 697 * Drop packet if shorter than we expect. 698 */ 699 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 700 ip6stat.ip6s_tooshort++; 701 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 702 goto bad; 703 } 704 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 705 if (m->m_len == m->m_pkthdr.len) { 706 m->m_len = sizeof(struct ip6_hdr) + plen; 707 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 708 } else 709 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 710 } 711 712 /* 713 * Forward if desirable. 714 */ 715 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 716 /* 717 * If we are acting as a multicast router, all 718 * incoming multicast packets are passed to the 719 * kernel-level multicast forwarding function. 720 * The packet is returned (relatively) intact; if 721 * ip6_mforward() returns a non-zero value, the packet 722 * must be discarded, else it may be accepted below. 723 */ 724 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 725 ip6stat.ip6s_cantforward++; 726 m_freem(m); 727 return; 728 } 729 if (!ours) { 730 m_freem(m); 731 return; 732 } 733 } else if (!ours) { 734 ip6_forward(m, srcrt); 735 return; 736 } 737 738 ip6 = mtod(m, struct ip6_hdr *); 739 740 /* 741 * Malicious party may be able to use IPv4 mapped addr to confuse 742 * tcp/udp stack and bypass security checks (act as if it was from 743 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 744 * 745 * For SIIT end node behavior, you may want to disable the check. 746 * However, you will become vulnerable to attacks using IPv4 mapped 747 * source. 748 */ 749 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 750 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 751 ip6stat.ip6s_badscope++; 752 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 753 goto bad; 754 } 755 756 /* 757 * Tell launch routine the next header 758 */ 759 ip6stat.ip6s_delivered++; 760 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 761 nest = 0; 762 763 while (nxt != IPPROTO_DONE) { 764 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 765 ip6stat.ip6s_toomanyhdr++; 766 goto bad; 767 } 768 769 /* 770 * protection against faulty packet - there should be 771 * more sanity checks in header chain processing. 772 */ 773 if (m->m_pkthdr.len < off) { 774 ip6stat.ip6s_tooshort++; 775 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 776 goto bad; 777 } 778 779 #ifdef IPSEC 780 /* 781 * enforce IPsec policy checking if we are seeing last header. 782 * note that we do not visit this with protocols with pcb layer 783 * code - like udp/tcp/raw ip. 784 */ 785 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 786 ipsec6_in_reject(m, NULL)) { 787 ipsec6stat.in_polvio++; 788 goto bad; 789 } 790 #endif 791 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 792 } 793 return; 794 bad: 795 m_freem(m); 796 } 797 798 /* 799 * set/grab in6_ifaddr correspond to IPv6 destination address. 800 * XXX backward compatibility wrapper 801 */ 802 static struct ip6aux * 803 ip6_setdstifaddr(m, ia6) 804 struct mbuf *m; 805 struct in6_ifaddr *ia6; 806 { 807 struct ip6aux *ip6a; 808 809 ip6a = ip6_addaux(m); 810 if (ip6a) 811 ip6a->ip6a_dstia6 = ia6; 812 return ip6a; /* NULL if failed to set */ 813 } 814 815 struct in6_ifaddr * 816 ip6_getdstifaddr(m) 817 struct mbuf *m; 818 { 819 struct ip6aux *ip6a; 820 821 ip6a = ip6_findaux(m); 822 if (ip6a) 823 return ip6a->ip6a_dstia6; 824 else 825 return NULL; 826 } 827 828 /* 829 * Hop-by-Hop options header processing. If a valid jumbo payload option is 830 * included, the real payload length will be stored in plenp. 831 */ 832 static int 833 ip6_hopopts_input(plenp, rtalertp, mp, offp) 834 u_int32_t *plenp; 835 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 836 struct mbuf **mp; 837 int *offp; 838 { 839 struct mbuf *m = *mp; 840 int off = *offp, hbhlen; 841 struct ip6_hbh *hbh; 842 u_int8_t *opt; 843 844 /* validation of the length of the header */ 845 #ifndef PULLDOWN_TEST 846 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 847 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 848 hbhlen = (hbh->ip6h_len + 1) << 3; 849 850 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 851 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 852 #else 853 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 854 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 855 if (hbh == NULL) { 856 ip6stat.ip6s_tooshort++; 857 return -1; 858 } 859 hbhlen = (hbh->ip6h_len + 1) << 3; 860 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 861 hbhlen); 862 if (hbh == NULL) { 863 ip6stat.ip6s_tooshort++; 864 return -1; 865 } 866 #endif 867 off += hbhlen; 868 hbhlen -= sizeof(struct ip6_hbh); 869 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 870 871 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 872 hbhlen, rtalertp, plenp) < 0) 873 return (-1); 874 875 *offp = off; 876 *mp = m; 877 return (0); 878 } 879 880 /* 881 * Search header for all Hop-by-hop options and process each option. 882 * This function is separate from ip6_hopopts_input() in order to 883 * handle a case where the sending node itself process its hop-by-hop 884 * options header. In such a case, the function is called from ip6_output(). 885 * 886 * The function assumes that hbh header is located right after the IPv6 header 887 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 888 * opthead + hbhlen is located in continuous memory region. 889 */ 890 int 891 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 892 struct mbuf *m; 893 u_int8_t *opthead; 894 int hbhlen; 895 u_int32_t *rtalertp; 896 u_int32_t *plenp; 897 { 898 struct ip6_hdr *ip6; 899 int optlen = 0; 900 u_int8_t *opt = opthead; 901 u_int16_t rtalert_val; 902 u_int32_t jumboplen; 903 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 904 905 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 906 switch (*opt) { 907 case IP6OPT_PAD1: 908 optlen = 1; 909 break; 910 case IP6OPT_PADN: 911 if (hbhlen < IP6OPT_MINLEN) { 912 ip6stat.ip6s_toosmall++; 913 goto bad; 914 } 915 optlen = *(opt + 1) + 2; 916 break; 917 case IP6OPT_ROUTER_ALERT: 918 /* XXX may need check for alignment */ 919 if (hbhlen < IP6OPT_RTALERT_LEN) { 920 ip6stat.ip6s_toosmall++; 921 goto bad; 922 } 923 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 924 /* XXX stat */ 925 icmp6_error(m, ICMP6_PARAM_PROB, 926 ICMP6_PARAMPROB_HEADER, 927 erroff + opt + 1 - opthead); 928 return (-1); 929 } 930 optlen = IP6OPT_RTALERT_LEN; 931 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 932 *rtalertp = ntohs(rtalert_val); 933 break; 934 case IP6OPT_JUMBO: 935 /* XXX may need check for alignment */ 936 if (hbhlen < IP6OPT_JUMBO_LEN) { 937 ip6stat.ip6s_toosmall++; 938 goto bad; 939 } 940 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 941 /* XXX stat */ 942 icmp6_error(m, ICMP6_PARAM_PROB, 943 ICMP6_PARAMPROB_HEADER, 944 erroff + opt + 1 - opthead); 945 return (-1); 946 } 947 optlen = IP6OPT_JUMBO_LEN; 948 949 /* 950 * IPv6 packets that have non 0 payload length 951 * must not contain a jumbo payload option. 952 */ 953 ip6 = mtod(m, struct ip6_hdr *); 954 if (ip6->ip6_plen) { 955 ip6stat.ip6s_badoptions++; 956 icmp6_error(m, ICMP6_PARAM_PROB, 957 ICMP6_PARAMPROB_HEADER, 958 erroff + opt - opthead); 959 return (-1); 960 } 961 962 /* 963 * We may see jumbolen in unaligned location, so 964 * we'd need to perform bcopy(). 965 */ 966 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 967 jumboplen = (u_int32_t)htonl(jumboplen); 968 969 #if 1 970 /* 971 * if there are multiple jumbo payload options, 972 * *plenp will be non-zero and the packet will be 973 * rejected. 974 * the behavior may need some debate in ipngwg - 975 * multiple options does not make sense, however, 976 * there's no explicit mention in specification. 977 */ 978 if (*plenp != 0) { 979 ip6stat.ip6s_badoptions++; 980 icmp6_error(m, ICMP6_PARAM_PROB, 981 ICMP6_PARAMPROB_HEADER, 982 erroff + opt + 2 - opthead); 983 return (-1); 984 } 985 #endif 986 987 /* 988 * jumbo payload length must be larger than 65535. 989 */ 990 if (jumboplen <= IPV6_MAXPACKET) { 991 ip6stat.ip6s_badoptions++; 992 icmp6_error(m, ICMP6_PARAM_PROB, 993 ICMP6_PARAMPROB_HEADER, 994 erroff + opt + 2 - opthead); 995 return (-1); 996 } 997 *plenp = jumboplen; 998 999 break; 1000 default: /* unknown option */ 1001 if (hbhlen < IP6OPT_MINLEN) { 1002 ip6stat.ip6s_toosmall++; 1003 goto bad; 1004 } 1005 optlen = ip6_unknown_opt(opt, m, 1006 erroff + opt - opthead); 1007 if (optlen == -1) 1008 return (-1); 1009 optlen += 2; 1010 break; 1011 } 1012 } 1013 1014 return (0); 1015 1016 bad: 1017 m_freem(m); 1018 return (-1); 1019 } 1020 1021 /* 1022 * Unknown option processing. 1023 * The third argument `off' is the offset from the IPv6 header to the option, 1024 * which is necessary if the IPv6 header the and option header and IPv6 header 1025 * is not continuous in order to return an ICMPv6 error. 1026 */ 1027 int 1028 ip6_unknown_opt(optp, m, off) 1029 u_int8_t *optp; 1030 struct mbuf *m; 1031 int off; 1032 { 1033 struct ip6_hdr *ip6; 1034 1035 switch (IP6OPT_TYPE(*optp)) { 1036 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1037 return ((int)*(optp + 1)); 1038 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1039 m_freem(m); 1040 return (-1); 1041 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1042 ip6stat.ip6s_badoptions++; 1043 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1044 return (-1); 1045 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1046 ip6stat.ip6s_badoptions++; 1047 ip6 = mtod(m, struct ip6_hdr *); 1048 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1049 (m->m_flags & (M_BCAST|M_MCAST))) 1050 m_freem(m); 1051 else 1052 icmp6_error(m, ICMP6_PARAM_PROB, 1053 ICMP6_PARAMPROB_OPTION, off); 1054 return (-1); 1055 } 1056 1057 m_freem(m); /* XXX: NOTREACHED */ 1058 return (-1); 1059 } 1060 1061 /* 1062 * Create the "control" list for this pcb. 1063 * The function will not modify mbuf chain at all. 1064 * 1065 * with KAME mbuf chain restriction: 1066 * The routine will be called from upper layer handlers like tcp6_input(). 1067 * Thus the routine assumes that the caller (tcp6_input) have already 1068 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1069 * very first mbuf on the mbuf chain. 1070 */ 1071 void 1072 ip6_savecontrol(in6p, m, mp) 1073 struct inpcb *in6p; 1074 struct mbuf *m, **mp; 1075 { 1076 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1077 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1078 1079 #ifdef SO_TIMESTAMP 1080 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1081 struct timeval tv; 1082 1083 microtime(&tv); 1084 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1085 SCM_TIMESTAMP, SOL_SOCKET); 1086 if (*mp) 1087 mp = &(*mp)->m_next; 1088 } 1089 #endif 1090 1091 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1092 return; 1093 1094 /* RFC 2292 sec. 5 */ 1095 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1096 struct in6_pktinfo pi6; 1097 1098 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1099 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1100 pi6.ipi6_ifindex = 1101 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1102 1103 *mp = sbcreatecontrol((caddr_t) &pi6, 1104 sizeof(struct in6_pktinfo), 1105 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1106 if (*mp) 1107 mp = &(*mp)->m_next; 1108 } 1109 1110 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1111 int hlim = ip6->ip6_hlim & 0xff; 1112 1113 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1114 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1115 if (*mp) 1116 mp = &(*mp)->m_next; 1117 } 1118 1119 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1120 u_int32_t flowinfo; 1121 int tclass; 1122 1123 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1124 flowinfo >>= 20; 1125 1126 tclass = flowinfo & 0xff; 1127 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1128 IPV6_TCLASS, IPPROTO_IPV6); 1129 if (*mp) 1130 mp = &(*mp)->m_next; 1131 } 1132 1133 /* 1134 * IPV6_HOPOPTS socket option. Recall that we required super-user 1135 * privilege for the option (see ip6_ctloutput), but it might be too 1136 * strict, since there might be some hop-by-hop options which can be 1137 * returned to normal user. 1138 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1139 */ 1140 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1141 /* 1142 * Check if a hop-by-hop options header is contatined in the 1143 * received packet, and if so, store the options as ancillary 1144 * data. Note that a hop-by-hop options header must be 1145 * just after the IPv6 header, which is assured through the 1146 * IPv6 input processing. 1147 */ 1148 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1149 struct ip6_hbh *hbh; 1150 int hbhlen = 0; 1151 #ifdef PULLDOWN_TEST 1152 struct mbuf *ext; 1153 #endif 1154 1155 #ifndef PULLDOWN_TEST 1156 hbh = (struct ip6_hbh *)(ip6 + 1); 1157 hbhlen = (hbh->ip6h_len + 1) << 3; 1158 #else 1159 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1160 ip6->ip6_nxt); 1161 if (ext == NULL) { 1162 ip6stat.ip6s_tooshort++; 1163 return; 1164 } 1165 hbh = mtod(ext, struct ip6_hbh *); 1166 hbhlen = (hbh->ip6h_len + 1) << 3; 1167 if (hbhlen != ext->m_len) { 1168 m_freem(ext); 1169 ip6stat.ip6s_tooshort++; 1170 return; 1171 } 1172 #endif 1173 1174 /* 1175 * XXX: We copy the whole header even if a 1176 * jumbo payload option is included, the option which 1177 * is to be removed before returning according to 1178 * RFC2292. 1179 * Note: this constraint is removed in RFC3542 1180 */ 1181 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1182 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1183 IPPROTO_IPV6); 1184 if (*mp) 1185 mp = &(*mp)->m_next; 1186 #ifdef PULLDOWN_TEST 1187 m_freem(ext); 1188 #endif 1189 } 1190 } 1191 1192 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1193 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1194 1195 /* 1196 * Search for destination options headers or routing 1197 * header(s) through the header chain, and stores each 1198 * header as ancillary data. 1199 * Note that the order of the headers remains in 1200 * the chain of ancillary data. 1201 */ 1202 while (1) { /* is explicit loop prevention necessary? */ 1203 struct ip6_ext *ip6e = NULL; 1204 int elen; 1205 #ifdef PULLDOWN_TEST 1206 struct mbuf *ext = NULL; 1207 #endif 1208 1209 /* 1210 * if it is not an extension header, don't try to 1211 * pull it from the chain. 1212 */ 1213 switch (nxt) { 1214 case IPPROTO_DSTOPTS: 1215 case IPPROTO_ROUTING: 1216 case IPPROTO_HOPOPTS: 1217 case IPPROTO_AH: /* is it possible? */ 1218 break; 1219 default: 1220 goto loopend; 1221 } 1222 1223 #ifndef PULLDOWN_TEST 1224 if (off + sizeof(*ip6e) > m->m_len) 1225 goto loopend; 1226 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1227 if (nxt == IPPROTO_AH) 1228 elen = (ip6e->ip6e_len + 2) << 2; 1229 else 1230 elen = (ip6e->ip6e_len + 1) << 3; 1231 if (off + elen > m->m_len) 1232 goto loopend; 1233 #else 1234 ext = ip6_pullexthdr(m, off, nxt); 1235 if (ext == NULL) { 1236 ip6stat.ip6s_tooshort++; 1237 return; 1238 } 1239 ip6e = mtod(ext, struct ip6_ext *); 1240 if (nxt == IPPROTO_AH) 1241 elen = (ip6e->ip6e_len + 2) << 2; 1242 else 1243 elen = (ip6e->ip6e_len + 1) << 3; 1244 if (elen != ext->m_len) { 1245 m_freem(ext); 1246 ip6stat.ip6s_tooshort++; 1247 return; 1248 } 1249 #endif 1250 1251 switch (nxt) { 1252 case IPPROTO_DSTOPTS: 1253 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1254 break; 1255 1256 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1257 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1258 IPPROTO_IPV6); 1259 if (*mp) 1260 mp = &(*mp)->m_next; 1261 break; 1262 case IPPROTO_ROUTING: 1263 if (!in6p->in6p_flags & IN6P_RTHDR) 1264 break; 1265 1266 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1267 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1268 IPPROTO_IPV6); 1269 if (*mp) 1270 mp = &(*mp)->m_next; 1271 break; 1272 case IPPROTO_HOPOPTS: 1273 case IPPROTO_AH: /* is it possible? */ 1274 break; 1275 1276 default: 1277 /* 1278 * other cases have been filtered in the above. 1279 * none will visit this case. here we supply 1280 * the code just in case (nxt overwritten or 1281 * other cases). 1282 */ 1283 #ifdef PULLDOWN_TEST 1284 m_freem(ext); 1285 #endif 1286 goto loopend; 1287 1288 } 1289 1290 /* proceed with the next header. */ 1291 off += elen; 1292 nxt = ip6e->ip6e_nxt; 1293 ip6e = NULL; 1294 #ifdef PULLDOWN_TEST 1295 m_freem(ext); 1296 ext = NULL; 1297 #endif 1298 } 1299 loopend: 1300 ; 1301 } 1302 1303 #undef IS2292 1304 } 1305 1306 void 1307 ip6_notify_pmtu(in6p, dst, mtu) 1308 struct inpcb *in6p; 1309 struct sockaddr_in6 *dst; 1310 u_int32_t *mtu; 1311 { 1312 struct socket *so; 1313 struct mbuf *m_mtu; 1314 struct ip6_mtuinfo mtuctl; 1315 1316 so = in6p->inp_socket; 1317 1318 if (mtu == NULL) 1319 return; 1320 1321 #ifdef DIAGNOSTIC 1322 if (so == NULL) /* I believe this is impossible */ 1323 panic("ip6_notify_pmtu: socket is NULL"); 1324 #endif 1325 1326 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1327 mtuctl.ip6m_mtu = *mtu; 1328 mtuctl.ip6m_addr = *dst; 1329 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1330 return; 1331 1332 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1333 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1334 return; 1335 1336 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1337 == 0) { 1338 m_freem(m_mtu); 1339 /* XXX: should count statistics */ 1340 } else 1341 sorwakeup(so); 1342 1343 return; 1344 } 1345 1346 #ifdef PULLDOWN_TEST 1347 /* 1348 * pull single extension header from mbuf chain. returns single mbuf that 1349 * contains the result, or NULL on error. 1350 */ 1351 static struct mbuf * 1352 ip6_pullexthdr(m, off, nxt) 1353 struct mbuf *m; 1354 size_t off; 1355 int nxt; 1356 { 1357 struct ip6_ext ip6e; 1358 size_t elen; 1359 struct mbuf *n; 1360 1361 #ifdef DIAGNOSTIC 1362 switch (nxt) { 1363 case IPPROTO_DSTOPTS: 1364 case IPPROTO_ROUTING: 1365 case IPPROTO_HOPOPTS: 1366 case IPPROTO_AH: /* is it possible? */ 1367 break; 1368 default: 1369 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1370 } 1371 #endif 1372 1373 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1374 if (nxt == IPPROTO_AH) 1375 elen = (ip6e.ip6e_len + 2) << 2; 1376 else 1377 elen = (ip6e.ip6e_len + 1) << 3; 1378 1379 MGET(n, M_DONTWAIT, MT_DATA); 1380 if (n && elen >= MLEN) { 1381 MCLGET(n, M_DONTWAIT); 1382 if ((n->m_flags & M_EXT) == 0) { 1383 m_free(n); 1384 n = NULL; 1385 } 1386 } 1387 if (!n) 1388 return NULL; 1389 1390 n->m_len = 0; 1391 if (elen >= M_TRAILINGSPACE(n)) { 1392 m_free(n); 1393 return NULL; 1394 } 1395 1396 m_copydata(m, off, elen, mtod(n, caddr_t)); 1397 n->m_len = elen; 1398 return n; 1399 } 1400 #endif 1401 1402 /* 1403 * Get pointer to the previous header followed by the header 1404 * currently processed. 1405 * XXX: This function supposes that 1406 * M includes all headers, 1407 * the next header field and the header length field of each header 1408 * are valid, and 1409 * the sum of each header length equals to OFF. 1410 * Because of these assumptions, this function must be called very 1411 * carefully. Moreover, it will not be used in the near future when 1412 * we develop `neater' mechanism to process extension headers. 1413 */ 1414 char * 1415 ip6_get_prevhdr(m, off) 1416 struct mbuf *m; 1417 int off; 1418 { 1419 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1420 1421 if (off == sizeof(struct ip6_hdr)) 1422 return (&ip6->ip6_nxt); 1423 else { 1424 int len, nxt; 1425 struct ip6_ext *ip6e = NULL; 1426 1427 nxt = ip6->ip6_nxt; 1428 len = sizeof(struct ip6_hdr); 1429 while (len < off) { 1430 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1431 1432 switch (nxt) { 1433 case IPPROTO_FRAGMENT: 1434 len += sizeof(struct ip6_frag); 1435 break; 1436 case IPPROTO_AH: 1437 len += (ip6e->ip6e_len + 2) << 2; 1438 break; 1439 default: 1440 len += (ip6e->ip6e_len + 1) << 3; 1441 break; 1442 } 1443 nxt = ip6e->ip6e_nxt; 1444 } 1445 if (ip6e) 1446 return (&ip6e->ip6e_nxt); 1447 else 1448 return NULL; 1449 } 1450 } 1451 1452 /* 1453 * get next header offset. m will be retained. 1454 */ 1455 int 1456 ip6_nexthdr(m, off, proto, nxtp) 1457 struct mbuf *m; 1458 int off; 1459 int proto; 1460 int *nxtp; 1461 { 1462 struct ip6_hdr ip6; 1463 struct ip6_ext ip6e; 1464 struct ip6_frag fh; 1465 1466 /* just in case */ 1467 if (m == NULL) 1468 panic("ip6_nexthdr: m == NULL"); 1469 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1470 return -1; 1471 1472 switch (proto) { 1473 case IPPROTO_IPV6: 1474 if (m->m_pkthdr.len < off + sizeof(ip6)) 1475 return -1; 1476 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1477 if (nxtp) 1478 *nxtp = ip6.ip6_nxt; 1479 off += sizeof(ip6); 1480 return off; 1481 1482 case IPPROTO_FRAGMENT: 1483 /* 1484 * terminate parsing if it is not the first fragment, 1485 * it does not make sense to parse through it. 1486 */ 1487 if (m->m_pkthdr.len < off + sizeof(fh)) 1488 return -1; 1489 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1490 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1491 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1492 return -1; 1493 if (nxtp) 1494 *nxtp = fh.ip6f_nxt; 1495 off += sizeof(struct ip6_frag); 1496 return off; 1497 1498 case IPPROTO_AH: 1499 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1500 return -1; 1501 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1502 if (nxtp) 1503 *nxtp = ip6e.ip6e_nxt; 1504 off += (ip6e.ip6e_len + 2) << 2; 1505 return off; 1506 1507 case IPPROTO_HOPOPTS: 1508 case IPPROTO_ROUTING: 1509 case IPPROTO_DSTOPTS: 1510 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1511 return -1; 1512 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1513 if (nxtp) 1514 *nxtp = ip6e.ip6e_nxt; 1515 off += (ip6e.ip6e_len + 1) << 3; 1516 return off; 1517 1518 case IPPROTO_NONE: 1519 case IPPROTO_ESP: 1520 case IPPROTO_IPCOMP: 1521 /* give up */ 1522 return -1; 1523 1524 default: 1525 return -1; 1526 } 1527 1528 return -1; 1529 } 1530 1531 /* 1532 * get offset for the last header in the chain. m will be kept untainted. 1533 */ 1534 int 1535 ip6_lasthdr(m, off, proto, nxtp) 1536 struct mbuf *m; 1537 int off; 1538 int proto; 1539 int *nxtp; 1540 { 1541 int newoff; 1542 int nxt; 1543 1544 if (!nxtp) { 1545 nxt = -1; 1546 nxtp = &nxt; 1547 } 1548 while (1) { 1549 newoff = ip6_nexthdr(m, off, proto, nxtp); 1550 if (newoff < 0) 1551 return off; 1552 else if (newoff < off) 1553 return -1; /* invalid */ 1554 else if (newoff == off) 1555 return newoff; 1556 1557 off = newoff; 1558 proto = *nxtp; 1559 } 1560 } 1561 1562 struct ip6aux * 1563 ip6_addaux(m) 1564 struct mbuf *m; 1565 { 1566 struct m_tag *mtag; 1567 1568 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1569 if (!mtag) { 1570 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1571 M_NOWAIT); 1572 if (mtag) { 1573 m_tag_prepend(m, mtag); 1574 bzero(mtag + 1, sizeof(struct ip6aux)); 1575 } 1576 } 1577 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1578 } 1579 1580 struct ip6aux * 1581 ip6_findaux(m) 1582 struct mbuf *m; 1583 { 1584 struct m_tag *mtag; 1585 1586 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1587 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1588 } 1589 1590 void 1591 ip6_delaux(m) 1592 struct mbuf *m; 1593 { 1594 struct m_tag *mtag; 1595 1596 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1597 if (mtag) 1598 m_tag_delete(m, mtag); 1599 } 1600 1601 /* 1602 * System control for IP6 1603 */ 1604 1605 u_char inet6ctlerrmap[PRC_NCMDS] = { 1606 0, 0, 0, 0, 1607 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1608 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1609 EMSGSIZE, EHOSTUNREACH, 0, 0, 1610 0, 0, 0, 0, 1611 ENOPROTOOPT 1612 };
Cache object: 2c377842763c427f511343d7bb11e4c7
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