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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: releng/8.1/sys/netinet6/ip6_input.c 236953 2012-06-12 12:10:10Z bz $"); 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 #include "opt_ipsec.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/proc.h> 75 #include <sys/domain.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/errno.h> 80 #include <sys/time.h> 81 #include <sys/kernel.h> 82 #include <sys/syslog.h> 83 84 #include <net/if.h> 85 #include <net/if_types.h> 86 #include <net/if_dl.h> 87 #include <net/route.h> 88 #include <net/netisr.h> 89 #include <net/pfil.h> 90 #include <net/vnet.h> 91 92 #include <netinet/in.h> 93 #include <netinet/in_systm.h> 94 #include <net/if_llatbl.h> 95 #ifdef INET 96 #include <netinet/ip.h> 97 #include <netinet/ip_icmp.h> 98 #endif /* INET */ 99 #include <netinet/ip6.h> 100 #include <netinet6/in6_var.h> 101 #include <netinet6/ip6_var.h> 102 #include <netinet/in_pcb.h> 103 #include <netinet/icmp6.h> 104 #include <netinet6/scope6_var.h> 105 #include <netinet6/in6_ifattach.h> 106 #include <netinet6/nd6.h> 107 108 #ifdef IPSEC 109 #include <netipsec/ipsec.h> 110 #include <netinet6/ip6_ipsec.h> 111 #include <netipsec/ipsec6.h> 112 #endif /* IPSEC */ 113 114 #include <netinet6/ip6protosw.h> 115 116 extern struct domain inet6domain; 117 118 u_char ip6_protox[IPPROTO_MAX]; 119 VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead); 120 121 static struct netisr_handler ip6_nh = { 122 .nh_name = "ip6", 123 .nh_handler = ip6_input, 124 .nh_proto = NETISR_IPV6, 125 .nh_policy = NETISR_POLICY_FLOW, 126 }; 127 128 VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch); 129 #define V_in6_tmpaddrtimer_ch VNET(in6_tmpaddrtimer_ch) 130 131 VNET_DEFINE(struct pfil_head, inet6_pfil_hook); 132 133 VNET_DEFINE(struct ip6stat, ip6stat); 134 135 struct rwlock in6_ifaddr_lock; 136 RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock"); 137 138 static void ip6_init2(void *); 139 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 140 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 141 #ifdef PULLDOWN_TEST 142 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 143 #endif 144 145 /* 146 * IP6 initialization: fill in IP6 protocol switch table. 147 * All protocols not implemented in kernel go to raw IP6 protocol handler. 148 */ 149 void 150 ip6_init(void) 151 { 152 struct ip6protosw *pr; 153 int i; 154 155 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal", 156 &V_ip6_auto_linklocal); 157 158 TAILQ_INIT(&V_in6_ifaddrhead); 159 160 /* Initialize packet filter hooks. */ 161 V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 162 V_inet6_pfil_hook.ph_af = AF_INET6; 163 if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0) 164 printf("%s: WARNING: unable to register pfil hook, " 165 "error %d\n", __func__, i); 166 167 scope6_init(); 168 addrsel_policy_init(); 169 nd6_init(); 170 frag6_init(); 171 172 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 173 174 /* Skip global initialization stuff for non-default instances. */ 175 if (!IS_DEFAULT_VNET(curvnet)) 176 return; 177 178 #ifdef DIAGNOSTIC 179 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 180 panic("sizeof(protosw) != sizeof(ip6protosw)"); 181 #endif 182 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 183 if (pr == NULL) 184 panic("ip6_init"); 185 186 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ 187 for (i = 0; i < IPPROTO_MAX; i++) 188 ip6_protox[i] = pr - inet6sw; 189 /* 190 * Cycle through IP protocols and put them into the appropriate place 191 * in ip6_protox[]. 192 */ 193 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 194 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 195 if (pr->pr_domain->dom_family == PF_INET6 && 196 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 197 /* Be careful to only index valid IP protocols. */ 198 if (pr->pr_protocol < IPPROTO_MAX) 199 ip6_protox[pr->pr_protocol] = pr - inet6sw; 200 } 201 202 netisr_register(&ip6_nh); 203 } 204 205 #ifdef VIMAGE 206 void 207 ip6_destroy() 208 { 209 210 nd6_destroy(); 211 callout_drain(&V_in6_tmpaddrtimer_ch); 212 } 213 #endif 214 215 static int 216 ip6_init2_vnet(const void *unused __unused) 217 { 218 219 /* nd6_timer_init */ 220 callout_init(&V_nd6_timer_ch, 0); 221 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet); 222 223 /* timer for regeneranation of temporary addresses randomize ID */ 224 callout_init(&V_in6_tmpaddrtimer_ch, 0); 225 callout_reset(&V_in6_tmpaddrtimer_ch, 226 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor - 227 V_ip6_temp_regen_advance) * hz, 228 in6_tmpaddrtimer, curvnet); 229 230 return (0); 231 } 232 233 static void 234 ip6_init2(void *dummy) 235 { 236 237 ip6_init2_vnet(NULL); 238 } 239 240 /* cheat */ 241 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 242 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 243 244 void 245 ip6_input(struct mbuf *m) 246 { 247 struct ip6_hdr *ip6; 248 int off = sizeof(struct ip6_hdr), nest; 249 u_int32_t plen; 250 u_int32_t rtalert = ~0; 251 int nxt, ours = 0; 252 struct ifnet *deliverifp = NULL, *ifp = NULL; 253 struct in6_addr odst; 254 struct route_in6 rin6; 255 int srcrt = 0; 256 struct llentry *lle = NULL; 257 struct sockaddr_in6 dst6, *dst; 258 259 bzero(&rin6, sizeof(struct route_in6)); 260 #ifdef IPSEC 261 /* 262 * should the inner packet be considered authentic? 263 * see comment in ah4_input(). 264 * NB: m cannot be NULL when passed to the input routine 265 */ 266 267 m->m_flags &= ~M_AUTHIPHDR; 268 m->m_flags &= ~M_AUTHIPDGM; 269 270 #endif /* IPSEC */ 271 272 /* 273 * make sure we don't have onion peering information into m_tag. 274 */ 275 ip6_delaux(m); 276 277 /* 278 * mbuf statistics 279 */ 280 if (m->m_flags & M_EXT) { 281 if (m->m_next) 282 V_ip6stat.ip6s_mext2m++; 283 else 284 V_ip6stat.ip6s_mext1++; 285 } else { 286 #define M2MMAX (sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0])) 287 if (m->m_next) { 288 if (m->m_flags & M_LOOP) { 289 V_ip6stat.ip6s_m2m[V_loif->if_index]++; 290 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 291 V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 292 else 293 V_ip6stat.ip6s_m2m[0]++; 294 } else 295 V_ip6stat.ip6s_m1++; 296 #undef M2MMAX 297 } 298 299 /* drop the packet if IPv6 operation is disabled on the IF */ 300 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 301 m_freem(m); 302 return; 303 } 304 305 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 306 V_ip6stat.ip6s_total++; 307 308 #ifndef PULLDOWN_TEST 309 /* 310 * L2 bridge code and some other code can return mbuf chain 311 * that does not conform to KAME requirement. too bad. 312 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 313 */ 314 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 315 struct mbuf *n; 316 317 MGETHDR(n, M_DONTWAIT, MT_HEADER); 318 if (n) 319 M_MOVE_PKTHDR(n, m); 320 if (n && n->m_pkthdr.len > MHLEN) { 321 MCLGET(n, M_DONTWAIT); 322 if ((n->m_flags & M_EXT) == 0) { 323 m_freem(n); 324 n = NULL; 325 } 326 } 327 if (n == NULL) { 328 m_freem(m); 329 return; /* ENOBUFS */ 330 } 331 332 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 333 n->m_len = n->m_pkthdr.len; 334 m_freem(m); 335 m = n; 336 } 337 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 338 #endif 339 340 if (m->m_len < sizeof(struct ip6_hdr)) { 341 struct ifnet *inifp; 342 inifp = m->m_pkthdr.rcvif; 343 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 344 V_ip6stat.ip6s_toosmall++; 345 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 346 return; 347 } 348 } 349 350 ip6 = mtod(m, struct ip6_hdr *); 351 352 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 353 V_ip6stat.ip6s_badvers++; 354 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 355 goto bad; 356 } 357 358 V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 359 360 /* 361 * Check against address spoofing/corruption. 362 */ 363 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 364 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 365 /* 366 * XXX: "badscope" is not very suitable for a multicast source. 367 */ 368 V_ip6stat.ip6s_badscope++; 369 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 370 goto bad; 371 } 372 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 373 !(m->m_flags & M_LOOP)) { 374 /* 375 * In this case, the packet should come from the loopback 376 * interface. However, we cannot just check the if_flags, 377 * because ip6_mloopback() passes the "actual" interface 378 * as the outgoing/incoming interface. 379 */ 380 V_ip6stat.ip6s_badscope++; 381 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 382 goto bad; 383 } 384 385 #ifdef ALTQ 386 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 387 /* packet is dropped by traffic conditioner */ 388 return; 389 } 390 #endif 391 /* 392 * The following check is not documented in specs. A malicious 393 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 394 * and bypass security checks (act as if it was from 127.0.0.1 by using 395 * IPv6 src ::ffff:127.0.0.1). Be cautious. 396 * 397 * This check chokes if we are in an SIIT cloud. As none of BSDs 398 * support IPv4-less kernel compilation, we cannot support SIIT 399 * environment at all. So, it makes more sense for us to reject any 400 * malicious packets for non-SIIT environment, than try to do a 401 * partial support for SIIT environment. 402 */ 403 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 404 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 405 V_ip6stat.ip6s_badscope++; 406 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 407 goto bad; 408 } 409 #if 0 410 /* 411 * Reject packets with IPv4 compatible addresses (auto tunnel). 412 * 413 * The code forbids auto tunnel relay case in RFC1933 (the check is 414 * stronger than RFC1933). We may want to re-enable it if mech-xx 415 * is revised to forbid relaying case. 416 */ 417 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 418 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 419 V_ip6stat.ip6s_badscope++; 420 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 421 goto bad; 422 } 423 #endif 424 425 /* 426 * Run through list of hooks for input packets. 427 * 428 * NB: Beware of the destination address changing 429 * (e.g. by NAT rewriting). When this happens, 430 * tell ip6_forward to do the right thing. 431 */ 432 odst = ip6->ip6_dst; 433 434 /* Jump over all PFIL processing if hooks are not active. */ 435 if (!PFIL_HOOKED(&V_inet6_pfil_hook)) 436 goto passin; 437 438 if (pfil_run_hooks(&V_inet6_pfil_hook, &m, 439 m->m_pkthdr.rcvif, PFIL_IN, NULL)) 440 return; 441 if (m == NULL) /* consumed by filter */ 442 return; 443 ip6 = mtod(m, struct ip6_hdr *); 444 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 445 446 passin: 447 /* 448 * Disambiguate address scope zones (if there is ambiguity). 449 * We first make sure that the original source or destination address 450 * is not in our internal form for scoped addresses. Such addresses 451 * are not necessarily invalid spec-wise, but we cannot accept them due 452 * to the usage conflict. 453 * in6_setscope() then also checks and rejects the cases where src or 454 * dst are the loopback address and the receiving interface 455 * is not loopback. 456 */ 457 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 458 V_ip6stat.ip6s_badscope++; /* XXX */ 459 goto bad; 460 } 461 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 462 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 463 V_ip6stat.ip6s_badscope++; 464 goto bad; 465 } 466 467 /* 468 * Multicast check. Assume packet is for us to avoid 469 * prematurely taking locks. 470 */ 471 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 472 ours = 1; 473 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 474 deliverifp = m->m_pkthdr.rcvif; 475 goto hbhcheck; 476 } 477 478 /* 479 * Unicast check 480 */ 481 482 bzero(&dst6, sizeof(dst6)); 483 dst6.sin6_family = AF_INET6; 484 dst6.sin6_len = sizeof(struct sockaddr_in6); 485 dst6.sin6_addr = ip6->ip6_dst; 486 ifp = m->m_pkthdr.rcvif; 487 IF_AFDATA_LOCK(ifp); 488 lle = lla_lookup(LLTABLE6(ifp), 0, 489 (struct sockaddr *)&dst6); 490 IF_AFDATA_UNLOCK(ifp); 491 if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) { 492 ours = 1; 493 deliverifp = ifp; 494 LLE_RUNLOCK(lle); 495 goto hbhcheck; 496 } 497 if (lle != NULL) 498 LLE_RUNLOCK(lle); 499 500 dst = &rin6.ro_dst; 501 dst->sin6_len = sizeof(struct sockaddr_in6); 502 dst->sin6_family = AF_INET6; 503 dst->sin6_addr = ip6->ip6_dst; 504 rin6.ro_rt = rtalloc1((struct sockaddr *)dst, 0, 0); 505 if (rin6.ro_rt) 506 RT_UNLOCK(rin6.ro_rt); 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 (rin6.ro_rt && 531 (rin6.ro_rt->rt_flags & 532 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 533 #ifdef RTF_WASCLONED 534 !(rin6.ro_rt->rt_flags & RTF_WASCLONED) && 535 #endif 536 #ifdef RTF_CLONED 537 !(rin6.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(rin6.ro_rt)->sin6_addr) 547 #endif 548 rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) { 549 int free_ia6 = 0; 550 struct in6_ifaddr *ia6; 551 552 /* 553 * found the loopback route to the interface address 554 */ 555 if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) { 556 struct sockaddr_in6 dest6; 557 558 bzero(&dest6, sizeof(dest6)); 559 dest6.sin6_family = AF_INET6; 560 dest6.sin6_len = sizeof(dest6); 561 dest6.sin6_addr = ip6->ip6_dst; 562 ia6 = (struct in6_ifaddr *) 563 ifa_ifwithaddr((struct sockaddr *)&dest6); 564 if (ia6 == NULL) 565 goto bad; 566 free_ia6 = 1; 567 } 568 else 569 ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa; 570 571 /* 572 * record address information into m_tag. 573 */ 574 (void)ip6_setdstifaddr(m, ia6); 575 576 /* 577 * packets to a tentative, duplicated, or somehow invalid 578 * address must not be accepted. 579 */ 580 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 581 /* this address is ready */ 582 ours = 1; 583 deliverifp = ia6->ia_ifp; /* correct? */ 584 /* Count the packet in the ip address stats */ 585 ia6->ia_ifa.if_ipackets++; 586 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 587 if (ia6 != NULL && free_ia6 != 0) 588 ifa_free(&ia6->ia_ifa); 589 goto hbhcheck; 590 } else { 591 char ip6bufs[INET6_ADDRSTRLEN]; 592 char ip6bufd[INET6_ADDRSTRLEN]; 593 /* address is not ready, so discard the packet. */ 594 nd6log((LOG_INFO, 595 "ip6_input: packet to an unready address %s->%s\n", 596 ip6_sprintf(ip6bufs, &ip6->ip6_src), 597 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 598 599 if (ia6 != NULL && free_ia6 != 0) 600 ifa_free(&ia6->ia_ifa); 601 goto bad; 602 } 603 } 604 605 /* 606 * FAITH (Firewall Aided Internet Translator) 607 */ 608 if (V_ip6_keepfaith) { 609 if (rin6.ro_rt && rin6.ro_rt->rt_ifp && 610 rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) { 611 /* XXX do we need more sanity checks? */ 612 ours = 1; 613 deliverifp = rin6.ro_rt->rt_ifp; /* faith */ 614 goto hbhcheck; 615 } 616 } 617 618 /* 619 * Now there is no reason to process the packet if it's not our own 620 * and we're not a router. 621 */ 622 if (!V_ip6_forwarding) { 623 V_ip6stat.ip6s_cantforward++; 624 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 625 goto bad; 626 } 627 628 hbhcheck: 629 /* 630 * record address information into m_tag, if we don't have one yet. 631 * note that we are unable to record it, if the address is not listed 632 * as our interface address (e.g. multicast addresses, addresses 633 * within FAITH prefixes and such). 634 */ 635 if (deliverifp) { 636 struct in6_ifaddr *ia6; 637 638 if ((ia6 = ip6_getdstifaddr(m)) != NULL) { 639 ifa_free(&ia6->ia_ifa); 640 } else { 641 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 642 if (ia6) { 643 if (!ip6_setdstifaddr(m, ia6)) { 644 /* 645 * XXX maybe we should drop the packet here, 646 * as we could not provide enough information 647 * to the upper layers. 648 */ 649 } 650 ifa_free(&ia6->ia_ifa); 651 } 652 } 653 } 654 655 /* 656 * Process Hop-by-Hop options header if it's contained. 657 * m may be modified in ip6_hopopts_input(). 658 * If a JumboPayload option is included, plen will also be modified. 659 */ 660 plen = (u_int32_t)ntohs(ip6->ip6_plen); 661 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 662 struct ip6_hbh *hbh; 663 664 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 665 #if 0 /*touches NULL pointer*/ 666 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 667 #endif 668 goto out; /* m have already been freed */ 669 } 670 671 /* adjust pointer */ 672 ip6 = mtod(m, struct ip6_hdr *); 673 674 /* 675 * if the payload length field is 0 and the next header field 676 * indicates Hop-by-Hop Options header, then a Jumbo Payload 677 * option MUST be included. 678 */ 679 if (ip6->ip6_plen == 0 && plen == 0) { 680 /* 681 * Note that if a valid jumbo payload option is 682 * contained, ip6_hopopts_input() must set a valid 683 * (non-zero) payload length to the variable plen. 684 */ 685 V_ip6stat.ip6s_badoptions++; 686 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 687 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 688 icmp6_error(m, ICMP6_PARAM_PROB, 689 ICMP6_PARAMPROB_HEADER, 690 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 691 goto out; 692 } 693 #ifndef PULLDOWN_TEST 694 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 695 hbh = (struct ip6_hbh *)(ip6 + 1); 696 #else 697 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 698 sizeof(struct ip6_hbh)); 699 if (hbh == NULL) { 700 V_ip6stat.ip6s_tooshort++; 701 goto out; 702 } 703 #endif 704 nxt = hbh->ip6h_nxt; 705 706 /* 707 * If we are acting as a router and the packet contains a 708 * router alert option, see if we know the option value. 709 * Currently, we only support the option value for MLD, in which 710 * case we should pass the packet to the multicast routing 711 * daemon. 712 */ 713 if (rtalert != ~0) { 714 switch (rtalert) { 715 case IP6OPT_RTALERT_MLD: 716 if (V_ip6_forwarding) 717 ours = 1; 718 break; 719 default: 720 /* 721 * RFC2711 requires unrecognized values must be 722 * silently ignored. 723 */ 724 break; 725 } 726 } 727 } else 728 nxt = ip6->ip6_nxt; 729 730 /* 731 * Check that the amount of data in the buffers 732 * is as at least much as the IPv6 header would have us expect. 733 * Trim mbufs if longer than we expect. 734 * Drop packet if shorter than we expect. 735 */ 736 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 737 V_ip6stat.ip6s_tooshort++; 738 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 739 goto bad; 740 } 741 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 742 if (m->m_len == m->m_pkthdr.len) { 743 m->m_len = sizeof(struct ip6_hdr) + plen; 744 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 745 } else 746 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 747 } 748 749 /* 750 * Forward if desirable. 751 */ 752 if (V_ip6_mrouter && 753 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 754 /* 755 * If we are acting as a multicast router, all 756 * incoming multicast packets are passed to the 757 * kernel-level multicast forwarding function. 758 * The packet is returned (relatively) intact; if 759 * ip6_mforward() returns a non-zero value, the packet 760 * must be discarded, else it may be accepted below. 761 * 762 * XXX TODO: Check hlim and multicast scope here to avoid 763 * unnecessarily calling into ip6_mforward(). 764 */ 765 if (ip6_mforward && 766 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 767 IP6STAT_INC(ip6s_cantforward); 768 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 769 goto bad; 770 } 771 } else if (!ours) { 772 ip6_forward(m, srcrt); 773 goto out; 774 } 775 776 ip6 = mtod(m, struct ip6_hdr *); 777 778 /* 779 * Malicious party may be able to use IPv4 mapped addr to confuse 780 * tcp/udp stack and bypass security checks (act as if it was from 781 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 782 * 783 * For SIIT end node behavior, you may want to disable the check. 784 * However, you will become vulnerable to attacks using IPv4 mapped 785 * source. 786 */ 787 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 788 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 789 V_ip6stat.ip6s_badscope++; 790 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 791 goto bad; 792 } 793 794 /* 795 * Tell launch routine the next header 796 */ 797 V_ip6stat.ip6s_delivered++; 798 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 799 nest = 0; 800 801 while (nxt != IPPROTO_DONE) { 802 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 803 V_ip6stat.ip6s_toomanyhdr++; 804 goto bad; 805 } 806 807 /* 808 * protection against faulty packet - there should be 809 * more sanity checks in header chain processing. 810 */ 811 if (m->m_pkthdr.len < off) { 812 V_ip6stat.ip6s_tooshort++; 813 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 814 goto bad; 815 } 816 817 #ifdef IPSEC 818 /* 819 * enforce IPsec policy checking if we are seeing last header. 820 * note that we do not visit this with protocols with pcb layer 821 * code - like udp/tcp/raw ip. 822 */ 823 if (ip6_ipsec_input(m, nxt)) 824 goto bad; 825 #endif /* IPSEC */ 826 827 /* 828 * Use mbuf flags to propagate Router Alert option to 829 * ICMPv6 layer, as hop-by-hop options have been stripped. 830 */ 831 if (nxt == IPPROTO_ICMPV6 && rtalert != ~0) 832 m->m_flags |= M_RTALERT_MLD; 833 834 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 835 } 836 goto out; 837 bad: 838 m_freem(m); 839 out: 840 if (rin6.ro_rt) 841 RTFREE(rin6.ro_rt); 842 } 843 844 /* 845 * set/grab in6_ifaddr correspond to IPv6 destination address. 846 * XXX backward compatibility wrapper 847 * 848 * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag, 849 * and then bump it when the tag is copied, and release it when the tag is 850 * freed. Unfortunately, m_tags don't support deep copies (yet), so instead 851 * we just bump the ia refcount when we receive it. This should be fixed. 852 */ 853 static struct ip6aux * 854 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 855 { 856 struct ip6aux *ip6a; 857 858 ip6a = ip6_addaux(m); 859 if (ip6a) 860 ip6a->ip6a_dstia6 = ia6; 861 return ip6a; /* NULL if failed to set */ 862 } 863 864 struct in6_ifaddr * 865 ip6_getdstifaddr(struct mbuf *m) 866 { 867 struct ip6aux *ip6a; 868 struct in6_ifaddr *ia; 869 870 ip6a = ip6_findaux(m); 871 if (ip6a) { 872 ia = ip6a->ip6a_dstia6; 873 ifa_ref(&ia->ia_ifa); 874 return ia; 875 } else 876 return NULL; 877 } 878 879 /* 880 * Hop-by-Hop options header processing. If a valid jumbo payload option is 881 * included, the real payload length will be stored in plenp. 882 * 883 * rtalertp - XXX: should be stored more smart way 884 */ 885 static int 886 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 887 struct mbuf **mp, int *offp) 888 { 889 struct mbuf *m = *mp; 890 int off = *offp, hbhlen; 891 struct ip6_hbh *hbh; 892 u_int8_t *opt; 893 894 /* validation of the length of the header */ 895 #ifndef PULLDOWN_TEST 896 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 897 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 898 hbhlen = (hbh->ip6h_len + 1) << 3; 899 900 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 901 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 902 #else 903 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 904 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 905 if (hbh == NULL) { 906 V_ip6stat.ip6s_tooshort++; 907 return -1; 908 } 909 hbhlen = (hbh->ip6h_len + 1) << 3; 910 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 911 hbhlen); 912 if (hbh == NULL) { 913 V_ip6stat.ip6s_tooshort++; 914 return -1; 915 } 916 #endif 917 off += hbhlen; 918 hbhlen -= sizeof(struct ip6_hbh); 919 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 920 921 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 922 hbhlen, rtalertp, plenp) < 0) 923 return (-1); 924 925 *offp = off; 926 *mp = m; 927 return (0); 928 } 929 930 /* 931 * Search header for all Hop-by-hop options and process each option. 932 * This function is separate from ip6_hopopts_input() in order to 933 * handle a case where the sending node itself process its hop-by-hop 934 * options header. In such a case, the function is called from ip6_output(). 935 * 936 * The function assumes that hbh header is located right after the IPv6 header 937 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 938 * opthead + hbhlen is located in continuous memory region. 939 */ 940 int 941 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 942 u_int32_t *rtalertp, u_int32_t *plenp) 943 { 944 struct ip6_hdr *ip6; 945 int optlen = 0; 946 u_int8_t *opt = opthead; 947 u_int16_t rtalert_val; 948 u_int32_t jumboplen; 949 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 950 951 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 952 switch (*opt) { 953 case IP6OPT_PAD1: 954 optlen = 1; 955 break; 956 case IP6OPT_PADN: 957 if (hbhlen < IP6OPT_MINLEN) { 958 V_ip6stat.ip6s_toosmall++; 959 goto bad; 960 } 961 optlen = *(opt + 1) + 2; 962 break; 963 case IP6OPT_ROUTER_ALERT: 964 /* XXX may need check for alignment */ 965 if (hbhlen < IP6OPT_RTALERT_LEN) { 966 V_ip6stat.ip6s_toosmall++; 967 goto bad; 968 } 969 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 970 /* XXX stat */ 971 icmp6_error(m, ICMP6_PARAM_PROB, 972 ICMP6_PARAMPROB_HEADER, 973 erroff + opt + 1 - opthead); 974 return (-1); 975 } 976 optlen = IP6OPT_RTALERT_LEN; 977 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 978 *rtalertp = ntohs(rtalert_val); 979 break; 980 case IP6OPT_JUMBO: 981 /* XXX may need check for alignment */ 982 if (hbhlen < IP6OPT_JUMBO_LEN) { 983 V_ip6stat.ip6s_toosmall++; 984 goto bad; 985 } 986 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 987 /* XXX stat */ 988 icmp6_error(m, ICMP6_PARAM_PROB, 989 ICMP6_PARAMPROB_HEADER, 990 erroff + opt + 1 - opthead); 991 return (-1); 992 } 993 optlen = IP6OPT_JUMBO_LEN; 994 995 /* 996 * IPv6 packets that have non 0 payload length 997 * must not contain a jumbo payload option. 998 */ 999 ip6 = mtod(m, struct ip6_hdr *); 1000 if (ip6->ip6_plen) { 1001 V_ip6stat.ip6s_badoptions++; 1002 icmp6_error(m, ICMP6_PARAM_PROB, 1003 ICMP6_PARAMPROB_HEADER, 1004 erroff + opt - opthead); 1005 return (-1); 1006 } 1007 1008 /* 1009 * We may see jumbolen in unaligned location, so 1010 * we'd need to perform bcopy(). 1011 */ 1012 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1013 jumboplen = (u_int32_t)htonl(jumboplen); 1014 1015 #if 1 1016 /* 1017 * if there are multiple jumbo payload options, 1018 * *plenp will be non-zero and the packet will be 1019 * rejected. 1020 * the behavior may need some debate in ipngwg - 1021 * multiple options does not make sense, however, 1022 * there's no explicit mention in specification. 1023 */ 1024 if (*plenp != 0) { 1025 V_ip6stat.ip6s_badoptions++; 1026 icmp6_error(m, ICMP6_PARAM_PROB, 1027 ICMP6_PARAMPROB_HEADER, 1028 erroff + opt + 2 - opthead); 1029 return (-1); 1030 } 1031 #endif 1032 1033 /* 1034 * jumbo payload length must be larger than 65535. 1035 */ 1036 if (jumboplen <= IPV6_MAXPACKET) { 1037 V_ip6stat.ip6s_badoptions++; 1038 icmp6_error(m, ICMP6_PARAM_PROB, 1039 ICMP6_PARAMPROB_HEADER, 1040 erroff + opt + 2 - opthead); 1041 return (-1); 1042 } 1043 *plenp = jumboplen; 1044 1045 break; 1046 default: /* unknown option */ 1047 if (hbhlen < IP6OPT_MINLEN) { 1048 V_ip6stat.ip6s_toosmall++; 1049 goto bad; 1050 } 1051 optlen = ip6_unknown_opt(opt, m, 1052 erroff + opt - opthead); 1053 if (optlen == -1) 1054 return (-1); 1055 optlen += 2; 1056 break; 1057 } 1058 } 1059 1060 return (0); 1061 1062 bad: 1063 m_freem(m); 1064 return (-1); 1065 } 1066 1067 /* 1068 * Unknown option processing. 1069 * The third argument `off' is the offset from the IPv6 header to the option, 1070 * which is necessary if the IPv6 header the and option header and IPv6 header 1071 * is not continuous in order to return an ICMPv6 error. 1072 */ 1073 int 1074 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1075 { 1076 struct ip6_hdr *ip6; 1077 1078 switch (IP6OPT_TYPE(*optp)) { 1079 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1080 return ((int)*(optp + 1)); 1081 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1082 m_freem(m); 1083 return (-1); 1084 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1085 V_ip6stat.ip6s_badoptions++; 1086 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1087 return (-1); 1088 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1089 V_ip6stat.ip6s_badoptions++; 1090 ip6 = mtod(m, struct ip6_hdr *); 1091 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1092 (m->m_flags & (M_BCAST|M_MCAST))) 1093 m_freem(m); 1094 else 1095 icmp6_error(m, ICMP6_PARAM_PROB, 1096 ICMP6_PARAMPROB_OPTION, off); 1097 return (-1); 1098 } 1099 1100 m_freem(m); /* XXX: NOTREACHED */ 1101 return (-1); 1102 } 1103 1104 /* 1105 * Create the "control" list for this pcb. 1106 * These functions will not modify mbuf chain at all. 1107 * 1108 * With KAME mbuf chain restriction: 1109 * The routine will be called from upper layer handlers like tcp6_input(). 1110 * Thus the routine assumes that the caller (tcp6_input) have already 1111 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1112 * very first mbuf on the mbuf chain. 1113 * 1114 * ip6_savecontrol_v4 will handle those options that are possible to be 1115 * set on a v4-mapped socket. 1116 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1117 * options and handle the v6-only ones itself. 1118 */ 1119 struct mbuf ** 1120 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1121 int *v4only) 1122 { 1123 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1124 1125 #ifdef SO_TIMESTAMP 1126 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1127 struct timeval tv; 1128 1129 microtime(&tv); 1130 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1131 SCM_TIMESTAMP, SOL_SOCKET); 1132 if (*mp) 1133 mp = &(*mp)->m_next; 1134 } 1135 #endif 1136 1137 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1138 if (v4only != NULL) 1139 *v4only = 1; 1140 return (mp); 1141 } 1142 1143 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1144 /* RFC 2292 sec. 5 */ 1145 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1146 struct in6_pktinfo pi6; 1147 1148 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1149 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1150 pi6.ipi6_ifindex = 1151 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1152 1153 *mp = sbcreatecontrol((caddr_t) &pi6, 1154 sizeof(struct in6_pktinfo), 1155 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1156 if (*mp) 1157 mp = &(*mp)->m_next; 1158 } 1159 1160 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1161 int hlim = ip6->ip6_hlim & 0xff; 1162 1163 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1164 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1165 IPPROTO_IPV6); 1166 if (*mp) 1167 mp = &(*mp)->m_next; 1168 } 1169 1170 if (v4only != NULL) 1171 *v4only = 0; 1172 return (mp); 1173 } 1174 1175 void 1176 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1177 { 1178 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1179 int v4only = 0; 1180 1181 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1182 if (v4only) 1183 return; 1184 1185 if ((in6p->inp_flags & IN6P_TCLASS) != 0) { 1186 u_int32_t flowinfo; 1187 int tclass; 1188 1189 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1190 flowinfo >>= 20; 1191 1192 tclass = flowinfo & 0xff; 1193 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1194 IPV6_TCLASS, IPPROTO_IPV6); 1195 if (*mp) 1196 mp = &(*mp)->m_next; 1197 } 1198 1199 /* 1200 * IPV6_HOPOPTS socket option. Recall that we required super-user 1201 * privilege for the option (see ip6_ctloutput), but it might be too 1202 * strict, since there might be some hop-by-hop options which can be 1203 * returned to normal user. 1204 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1205 */ 1206 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1207 /* 1208 * Check if a hop-by-hop options header is contatined in the 1209 * received packet, and if so, store the options as ancillary 1210 * data. Note that a hop-by-hop options header must be 1211 * just after the IPv6 header, which is assured through the 1212 * IPv6 input processing. 1213 */ 1214 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1215 struct ip6_hbh *hbh; 1216 int hbhlen = 0; 1217 #ifdef PULLDOWN_TEST 1218 struct mbuf *ext; 1219 #endif 1220 1221 #ifndef PULLDOWN_TEST 1222 hbh = (struct ip6_hbh *)(ip6 + 1); 1223 hbhlen = (hbh->ip6h_len + 1) << 3; 1224 #else 1225 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1226 ip6->ip6_nxt); 1227 if (ext == NULL) { 1228 V_ip6stat.ip6s_tooshort++; 1229 return; 1230 } 1231 hbh = mtod(ext, struct ip6_hbh *); 1232 hbhlen = (hbh->ip6h_len + 1) << 3; 1233 if (hbhlen != ext->m_len) { 1234 m_freem(ext); 1235 V_ip6stat.ip6s_tooshort++; 1236 return; 1237 } 1238 #endif 1239 1240 /* 1241 * XXX: We copy the whole header even if a 1242 * jumbo payload option is included, the option which 1243 * is to be removed before returning according to 1244 * RFC2292. 1245 * Note: this constraint is removed in RFC3542 1246 */ 1247 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1248 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1249 IPPROTO_IPV6); 1250 if (*mp) 1251 mp = &(*mp)->m_next; 1252 #ifdef PULLDOWN_TEST 1253 m_freem(ext); 1254 #endif 1255 } 1256 } 1257 1258 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1259 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1260 1261 /* 1262 * Search for destination options headers or routing 1263 * header(s) through the header chain, and stores each 1264 * header as ancillary data. 1265 * Note that the order of the headers remains in 1266 * the chain of ancillary data. 1267 */ 1268 while (1) { /* is explicit loop prevention necessary? */ 1269 struct ip6_ext *ip6e = NULL; 1270 int elen; 1271 #ifdef PULLDOWN_TEST 1272 struct mbuf *ext = NULL; 1273 #endif 1274 1275 /* 1276 * if it is not an extension header, don't try to 1277 * pull it from the chain. 1278 */ 1279 switch (nxt) { 1280 case IPPROTO_DSTOPTS: 1281 case IPPROTO_ROUTING: 1282 case IPPROTO_HOPOPTS: 1283 case IPPROTO_AH: /* is it possible? */ 1284 break; 1285 default: 1286 goto loopend; 1287 } 1288 1289 #ifndef PULLDOWN_TEST 1290 if (off + sizeof(*ip6e) > m->m_len) 1291 goto loopend; 1292 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1293 if (nxt == IPPROTO_AH) 1294 elen = (ip6e->ip6e_len + 2) << 2; 1295 else 1296 elen = (ip6e->ip6e_len + 1) << 3; 1297 if (off + elen > m->m_len) 1298 goto loopend; 1299 #else 1300 ext = ip6_pullexthdr(m, off, nxt); 1301 if (ext == NULL) { 1302 V_ip6stat.ip6s_tooshort++; 1303 return; 1304 } 1305 ip6e = mtod(ext, struct ip6_ext *); 1306 if (nxt == IPPROTO_AH) 1307 elen = (ip6e->ip6e_len + 2) << 2; 1308 else 1309 elen = (ip6e->ip6e_len + 1) << 3; 1310 if (elen != ext->m_len) { 1311 m_freem(ext); 1312 V_ip6stat.ip6s_tooshort++; 1313 return; 1314 } 1315 #endif 1316 1317 switch (nxt) { 1318 case IPPROTO_DSTOPTS: 1319 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1320 break; 1321 1322 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1323 IS2292(in6p, 1324 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1325 IPPROTO_IPV6); 1326 if (*mp) 1327 mp = &(*mp)->m_next; 1328 break; 1329 case IPPROTO_ROUTING: 1330 if (!in6p->inp_flags & IN6P_RTHDR) 1331 break; 1332 1333 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1334 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1335 IPPROTO_IPV6); 1336 if (*mp) 1337 mp = &(*mp)->m_next; 1338 break; 1339 case IPPROTO_HOPOPTS: 1340 case IPPROTO_AH: /* is it possible? */ 1341 break; 1342 1343 default: 1344 /* 1345 * other cases have been filtered in the above. 1346 * none will visit this case. here we supply 1347 * the code just in case (nxt overwritten or 1348 * other cases). 1349 */ 1350 #ifdef PULLDOWN_TEST 1351 m_freem(ext); 1352 #endif 1353 goto loopend; 1354 1355 } 1356 1357 /* proceed with the next header. */ 1358 off += elen; 1359 nxt = ip6e->ip6e_nxt; 1360 ip6e = NULL; 1361 #ifdef PULLDOWN_TEST 1362 m_freem(ext); 1363 ext = NULL; 1364 #endif 1365 } 1366 loopend: 1367 ; 1368 } 1369 } 1370 #undef IS2292 1371 1372 void 1373 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1374 { 1375 struct socket *so; 1376 struct mbuf *m_mtu; 1377 struct ip6_mtuinfo mtuctl; 1378 1379 so = in6p->inp_socket; 1380 1381 if (mtu == NULL) 1382 return; 1383 1384 #ifdef DIAGNOSTIC 1385 if (so == NULL) /* I believe this is impossible */ 1386 panic("ip6_notify_pmtu: socket is NULL"); 1387 #endif 1388 1389 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1390 mtuctl.ip6m_mtu = *mtu; 1391 mtuctl.ip6m_addr = *dst; 1392 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1393 return; 1394 1395 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1396 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1397 return; 1398 1399 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1400 == 0) { 1401 m_freem(m_mtu); 1402 /* XXX: should count statistics */ 1403 } else 1404 sorwakeup(so); 1405 1406 return; 1407 } 1408 1409 #ifdef PULLDOWN_TEST 1410 /* 1411 * pull single extension header from mbuf chain. returns single mbuf that 1412 * contains the result, or NULL on error. 1413 */ 1414 static struct mbuf * 1415 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1416 { 1417 struct ip6_ext ip6e; 1418 size_t elen; 1419 struct mbuf *n; 1420 1421 #ifdef DIAGNOSTIC 1422 switch (nxt) { 1423 case IPPROTO_DSTOPTS: 1424 case IPPROTO_ROUTING: 1425 case IPPROTO_HOPOPTS: 1426 case IPPROTO_AH: /* is it possible? */ 1427 break; 1428 default: 1429 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1430 } 1431 #endif 1432 1433 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1434 if (nxt == IPPROTO_AH) 1435 elen = (ip6e.ip6e_len + 2) << 2; 1436 else 1437 elen = (ip6e.ip6e_len + 1) << 3; 1438 1439 MGET(n, M_DONTWAIT, MT_DATA); 1440 if (n && elen >= MLEN) { 1441 MCLGET(n, M_DONTWAIT); 1442 if ((n->m_flags & M_EXT) == 0) { 1443 m_free(n); 1444 n = NULL; 1445 } 1446 } 1447 if (!n) 1448 return NULL; 1449 1450 n->m_len = 0; 1451 if (elen >= M_TRAILINGSPACE(n)) { 1452 m_free(n); 1453 return NULL; 1454 } 1455 1456 m_copydata(m, off, elen, mtod(n, caddr_t)); 1457 n->m_len = elen; 1458 return n; 1459 } 1460 #endif 1461 1462 /* 1463 * Get pointer to the previous header followed by the header 1464 * currently processed. 1465 * XXX: This function supposes that 1466 * M includes all headers, 1467 * the next header field and the header length field of each header 1468 * are valid, and 1469 * the sum of each header length equals to OFF. 1470 * Because of these assumptions, this function must be called very 1471 * carefully. Moreover, it will not be used in the near future when 1472 * we develop `neater' mechanism to process extension headers. 1473 */ 1474 char * 1475 ip6_get_prevhdr(struct mbuf *m, int off) 1476 { 1477 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1478 1479 if (off == sizeof(struct ip6_hdr)) 1480 return (&ip6->ip6_nxt); 1481 else { 1482 int len, nxt; 1483 struct ip6_ext *ip6e = NULL; 1484 1485 nxt = ip6->ip6_nxt; 1486 len = sizeof(struct ip6_hdr); 1487 while (len < off) { 1488 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1489 1490 switch (nxt) { 1491 case IPPROTO_FRAGMENT: 1492 len += sizeof(struct ip6_frag); 1493 break; 1494 case IPPROTO_AH: 1495 len += (ip6e->ip6e_len + 2) << 2; 1496 break; 1497 default: 1498 len += (ip6e->ip6e_len + 1) << 3; 1499 break; 1500 } 1501 nxt = ip6e->ip6e_nxt; 1502 } 1503 if (ip6e) 1504 return (&ip6e->ip6e_nxt); 1505 else 1506 return NULL; 1507 } 1508 } 1509 1510 /* 1511 * get next header offset. m will be retained. 1512 */ 1513 int 1514 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1515 { 1516 struct ip6_hdr ip6; 1517 struct ip6_ext ip6e; 1518 struct ip6_frag fh; 1519 1520 /* just in case */ 1521 if (m == NULL) 1522 panic("ip6_nexthdr: m == NULL"); 1523 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1524 return -1; 1525 1526 switch (proto) { 1527 case IPPROTO_IPV6: 1528 if (m->m_pkthdr.len < off + sizeof(ip6)) 1529 return -1; 1530 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1531 if (nxtp) 1532 *nxtp = ip6.ip6_nxt; 1533 off += sizeof(ip6); 1534 return off; 1535 1536 case IPPROTO_FRAGMENT: 1537 /* 1538 * terminate parsing if it is not the first fragment, 1539 * it does not make sense to parse through it. 1540 */ 1541 if (m->m_pkthdr.len < off + sizeof(fh)) 1542 return -1; 1543 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1544 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1545 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1546 return -1; 1547 if (nxtp) 1548 *nxtp = fh.ip6f_nxt; 1549 off += sizeof(struct ip6_frag); 1550 return off; 1551 1552 case IPPROTO_AH: 1553 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1554 return -1; 1555 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1556 if (nxtp) 1557 *nxtp = ip6e.ip6e_nxt; 1558 off += (ip6e.ip6e_len + 2) << 2; 1559 return off; 1560 1561 case IPPROTO_HOPOPTS: 1562 case IPPROTO_ROUTING: 1563 case IPPROTO_DSTOPTS: 1564 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1565 return -1; 1566 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1567 if (nxtp) 1568 *nxtp = ip6e.ip6e_nxt; 1569 off += (ip6e.ip6e_len + 1) << 3; 1570 return off; 1571 1572 case IPPROTO_NONE: 1573 case IPPROTO_ESP: 1574 case IPPROTO_IPCOMP: 1575 /* give up */ 1576 return -1; 1577 1578 default: 1579 return -1; 1580 } 1581 1582 return -1; 1583 } 1584 1585 /* 1586 * get offset for the last header in the chain. m will be kept untainted. 1587 */ 1588 int 1589 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1590 { 1591 int newoff; 1592 int nxt; 1593 1594 if (!nxtp) { 1595 nxt = -1; 1596 nxtp = &nxt; 1597 } 1598 while (1) { 1599 newoff = ip6_nexthdr(m, off, proto, nxtp); 1600 if (newoff < 0) 1601 return off; 1602 else if (newoff < off) 1603 return -1; /* invalid */ 1604 else if (newoff == off) 1605 return newoff; 1606 1607 off = newoff; 1608 proto = *nxtp; 1609 } 1610 } 1611 1612 struct ip6aux * 1613 ip6_addaux(struct mbuf *m) 1614 { 1615 struct m_tag *mtag; 1616 1617 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1618 if (!mtag) { 1619 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1620 M_NOWAIT); 1621 if (mtag) { 1622 m_tag_prepend(m, mtag); 1623 bzero(mtag + 1, sizeof(struct ip6aux)); 1624 } 1625 } 1626 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1627 } 1628 1629 struct ip6aux * 1630 ip6_findaux(struct mbuf *m) 1631 { 1632 struct m_tag *mtag; 1633 1634 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1635 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1636 } 1637 1638 void 1639 ip6_delaux(struct mbuf *m) 1640 { 1641 struct m_tag *mtag; 1642 1643 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1644 if (mtag) 1645 m_tag_delete(m, mtag); 1646 } 1647 1648 /* 1649 * System control for IP6 1650 */ 1651 1652 u_char inet6ctlerrmap[PRC_NCMDS] = { 1653 0, 0, 0, 0, 1654 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1655 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1656 EMSGSIZE, EHOSTUNREACH, 0, 0, 1657 0, 0, 0, 0, 1658 ENOPROTOOPT 1659 };
Cache object: 1244bb4eff2a908198406ce610166759
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