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_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 && !ip6_getdstifaddr(m)) { 636 struct in6_ifaddr *ia6; 637 638 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 639 if (ia6) { 640 if (!ip6_setdstifaddr(m, ia6)) { 641 /* 642 * XXX maybe we should drop the packet here, 643 * as we could not provide enough information 644 * to the upper layers. 645 */ 646 } 647 ifa_free(&ia6->ia_ifa); 648 } 649 } 650 651 /* 652 * Process Hop-by-Hop options header if it's contained. 653 * m may be modified in ip6_hopopts_input(). 654 * If a JumboPayload option is included, plen will also be modified. 655 */ 656 plen = (u_int32_t)ntohs(ip6->ip6_plen); 657 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 658 struct ip6_hbh *hbh; 659 660 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 661 #if 0 /*touches NULL pointer*/ 662 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 663 #endif 664 goto out; /* m have already been freed */ 665 } 666 667 /* adjust pointer */ 668 ip6 = mtod(m, struct ip6_hdr *); 669 670 /* 671 * if the payload length field is 0 and the next header field 672 * indicates Hop-by-Hop Options header, then a Jumbo Payload 673 * option MUST be included. 674 */ 675 if (ip6->ip6_plen == 0 && plen == 0) { 676 /* 677 * Note that if a valid jumbo payload option is 678 * contained, ip6_hopopts_input() must set a valid 679 * (non-zero) payload length to the variable plen. 680 */ 681 V_ip6stat.ip6s_badoptions++; 682 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 683 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 684 icmp6_error(m, ICMP6_PARAM_PROB, 685 ICMP6_PARAMPROB_HEADER, 686 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 687 goto out; 688 } 689 #ifndef PULLDOWN_TEST 690 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 691 hbh = (struct ip6_hbh *)(ip6 + 1); 692 #else 693 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 694 sizeof(struct ip6_hbh)); 695 if (hbh == NULL) { 696 V_ip6stat.ip6s_tooshort++; 697 goto out; 698 } 699 #endif 700 nxt = hbh->ip6h_nxt; 701 702 /* 703 * If we are acting as a router and the packet contains a 704 * router alert option, see if we know the option value. 705 * Currently, we only support the option value for MLD, in which 706 * case we should pass the packet to the multicast routing 707 * daemon. 708 */ 709 if (rtalert != ~0) { 710 switch (rtalert) { 711 case IP6OPT_RTALERT_MLD: 712 if (V_ip6_forwarding) 713 ours = 1; 714 break; 715 default: 716 /* 717 * RFC2711 requires unrecognized values must be 718 * silently ignored. 719 */ 720 break; 721 } 722 } 723 } else 724 nxt = ip6->ip6_nxt; 725 726 /* 727 * Check that the amount of data in the buffers 728 * is as at least much as the IPv6 header would have us expect. 729 * Trim mbufs if longer than we expect. 730 * Drop packet if shorter than we expect. 731 */ 732 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 733 V_ip6stat.ip6s_tooshort++; 734 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 735 goto bad; 736 } 737 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 738 if (m->m_len == m->m_pkthdr.len) { 739 m->m_len = sizeof(struct ip6_hdr) + plen; 740 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 741 } else 742 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 743 } 744 745 /* 746 * Forward if desirable. 747 */ 748 if (V_ip6_mrouter && 749 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 750 /* 751 * If we are acting as a multicast router, all 752 * incoming multicast packets are passed to the 753 * kernel-level multicast forwarding function. 754 * The packet is returned (relatively) intact; if 755 * ip6_mforward() returns a non-zero value, the packet 756 * must be discarded, else it may be accepted below. 757 * 758 * XXX TODO: Check hlim and multicast scope here to avoid 759 * unnecessarily calling into ip6_mforward(). 760 */ 761 if (ip6_mforward && 762 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 763 IP6STAT_INC(ip6s_cantforward); 764 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 765 goto bad; 766 } 767 } else if (!ours) { 768 ip6_forward(m, srcrt); 769 goto out; 770 } 771 772 ip6 = mtod(m, struct ip6_hdr *); 773 774 /* 775 * Malicious party may be able to use IPv4 mapped addr to confuse 776 * tcp/udp stack and bypass security checks (act as if it was from 777 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 778 * 779 * For SIIT end node behavior, you may want to disable the check. 780 * However, you will become vulnerable to attacks using IPv4 mapped 781 * source. 782 */ 783 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 784 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 785 V_ip6stat.ip6s_badscope++; 786 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 787 goto bad; 788 } 789 790 /* 791 * Tell launch routine the next header 792 */ 793 V_ip6stat.ip6s_delivered++; 794 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 795 nest = 0; 796 797 while (nxt != IPPROTO_DONE) { 798 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 799 V_ip6stat.ip6s_toomanyhdr++; 800 goto bad; 801 } 802 803 /* 804 * protection against faulty packet - there should be 805 * more sanity checks in header chain processing. 806 */ 807 if (m->m_pkthdr.len < off) { 808 V_ip6stat.ip6s_tooshort++; 809 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 810 goto bad; 811 } 812 813 #ifdef IPSEC 814 /* 815 * enforce IPsec policy checking if we are seeing last header. 816 * note that we do not visit this with protocols with pcb layer 817 * code - like udp/tcp/raw ip. 818 */ 819 if (ip6_ipsec_input(m, nxt)) 820 goto bad; 821 #endif /* IPSEC */ 822 823 /* 824 * Use mbuf flags to propagate Router Alert option to 825 * ICMPv6 layer, as hop-by-hop options have been stripped. 826 */ 827 if (nxt == IPPROTO_ICMPV6 && rtalert != ~0) 828 m->m_flags |= M_RTALERT_MLD; 829 830 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 831 } 832 goto out; 833 bad: 834 m_freem(m); 835 out: 836 if (rin6.ro_rt) 837 RTFREE(rin6.ro_rt); 838 } 839 840 /* 841 * set/grab in6_ifaddr correspond to IPv6 destination address. 842 * XXX backward compatibility wrapper 843 * 844 * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag, 845 * and then bump it when the tag is copied, and release it when the tag is 846 * freed. Unfortunately, m_tags don't support deep copies (yet), so instead 847 * we just bump the ia refcount when we receive it. This should be fixed. 848 */ 849 static struct ip6aux * 850 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 851 { 852 struct ip6aux *ip6a; 853 854 ip6a = ip6_addaux(m); 855 if (ip6a) 856 ip6a->ip6a_dstia6 = ia6; 857 return ip6a; /* NULL if failed to set */ 858 } 859 860 struct in6_ifaddr * 861 ip6_getdstifaddr(struct mbuf *m) 862 { 863 struct ip6aux *ip6a; 864 struct in6_ifaddr *ia; 865 866 ip6a = ip6_findaux(m); 867 if (ip6a) { 868 ia = ip6a->ip6a_dstia6; 869 ifa_ref(&ia->ia_ifa); 870 return ia; 871 } else 872 return NULL; 873 } 874 875 /* 876 * Hop-by-Hop options header processing. If a valid jumbo payload option is 877 * included, the real payload length will be stored in plenp. 878 * 879 * rtalertp - XXX: should be stored more smart way 880 */ 881 static int 882 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 883 struct mbuf **mp, int *offp) 884 { 885 struct mbuf *m = *mp; 886 int off = *offp, hbhlen; 887 struct ip6_hbh *hbh; 888 u_int8_t *opt; 889 890 /* validation of the length of the header */ 891 #ifndef PULLDOWN_TEST 892 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 893 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 894 hbhlen = (hbh->ip6h_len + 1) << 3; 895 896 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 897 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 898 #else 899 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 900 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 901 if (hbh == NULL) { 902 V_ip6stat.ip6s_tooshort++; 903 return -1; 904 } 905 hbhlen = (hbh->ip6h_len + 1) << 3; 906 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 907 hbhlen); 908 if (hbh == NULL) { 909 V_ip6stat.ip6s_tooshort++; 910 return -1; 911 } 912 #endif 913 off += hbhlen; 914 hbhlen -= sizeof(struct ip6_hbh); 915 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 916 917 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 918 hbhlen, rtalertp, plenp) < 0) 919 return (-1); 920 921 *offp = off; 922 *mp = m; 923 return (0); 924 } 925 926 /* 927 * Search header for all Hop-by-hop options and process each option. 928 * This function is separate from ip6_hopopts_input() in order to 929 * handle a case where the sending node itself process its hop-by-hop 930 * options header. In such a case, the function is called from ip6_output(). 931 * 932 * The function assumes that hbh header is located right after the IPv6 header 933 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 934 * opthead + hbhlen is located in continuous memory region. 935 */ 936 int 937 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 938 u_int32_t *rtalertp, u_int32_t *plenp) 939 { 940 struct ip6_hdr *ip6; 941 int optlen = 0; 942 u_int8_t *opt = opthead; 943 u_int16_t rtalert_val; 944 u_int32_t jumboplen; 945 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 946 947 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 948 switch (*opt) { 949 case IP6OPT_PAD1: 950 optlen = 1; 951 break; 952 case IP6OPT_PADN: 953 if (hbhlen < IP6OPT_MINLEN) { 954 V_ip6stat.ip6s_toosmall++; 955 goto bad; 956 } 957 optlen = *(opt + 1) + 2; 958 break; 959 case IP6OPT_ROUTER_ALERT: 960 /* XXX may need check for alignment */ 961 if (hbhlen < IP6OPT_RTALERT_LEN) { 962 V_ip6stat.ip6s_toosmall++; 963 goto bad; 964 } 965 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 966 /* XXX stat */ 967 icmp6_error(m, ICMP6_PARAM_PROB, 968 ICMP6_PARAMPROB_HEADER, 969 erroff + opt + 1 - opthead); 970 return (-1); 971 } 972 optlen = IP6OPT_RTALERT_LEN; 973 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 974 *rtalertp = ntohs(rtalert_val); 975 break; 976 case IP6OPT_JUMBO: 977 /* XXX may need check for alignment */ 978 if (hbhlen < IP6OPT_JUMBO_LEN) { 979 V_ip6stat.ip6s_toosmall++; 980 goto bad; 981 } 982 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 983 /* XXX stat */ 984 icmp6_error(m, ICMP6_PARAM_PROB, 985 ICMP6_PARAMPROB_HEADER, 986 erroff + opt + 1 - opthead); 987 return (-1); 988 } 989 optlen = IP6OPT_JUMBO_LEN; 990 991 /* 992 * IPv6 packets that have non 0 payload length 993 * must not contain a jumbo payload option. 994 */ 995 ip6 = mtod(m, struct ip6_hdr *); 996 if (ip6->ip6_plen) { 997 V_ip6stat.ip6s_badoptions++; 998 icmp6_error(m, ICMP6_PARAM_PROB, 999 ICMP6_PARAMPROB_HEADER, 1000 erroff + opt - opthead); 1001 return (-1); 1002 } 1003 1004 /* 1005 * We may see jumbolen in unaligned location, so 1006 * we'd need to perform bcopy(). 1007 */ 1008 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1009 jumboplen = (u_int32_t)htonl(jumboplen); 1010 1011 #if 1 1012 /* 1013 * if there are multiple jumbo payload options, 1014 * *plenp will be non-zero and the packet will be 1015 * rejected. 1016 * the behavior may need some debate in ipngwg - 1017 * multiple options does not make sense, however, 1018 * there's no explicit mention in specification. 1019 */ 1020 if (*plenp != 0) { 1021 V_ip6stat.ip6s_badoptions++; 1022 icmp6_error(m, ICMP6_PARAM_PROB, 1023 ICMP6_PARAMPROB_HEADER, 1024 erroff + opt + 2 - opthead); 1025 return (-1); 1026 } 1027 #endif 1028 1029 /* 1030 * jumbo payload length must be larger than 65535. 1031 */ 1032 if (jumboplen <= IPV6_MAXPACKET) { 1033 V_ip6stat.ip6s_badoptions++; 1034 icmp6_error(m, ICMP6_PARAM_PROB, 1035 ICMP6_PARAMPROB_HEADER, 1036 erroff + opt + 2 - opthead); 1037 return (-1); 1038 } 1039 *plenp = jumboplen; 1040 1041 break; 1042 default: /* unknown option */ 1043 if (hbhlen < IP6OPT_MINLEN) { 1044 V_ip6stat.ip6s_toosmall++; 1045 goto bad; 1046 } 1047 optlen = ip6_unknown_opt(opt, m, 1048 erroff + opt - opthead); 1049 if (optlen == -1) 1050 return (-1); 1051 optlen += 2; 1052 break; 1053 } 1054 } 1055 1056 return (0); 1057 1058 bad: 1059 m_freem(m); 1060 return (-1); 1061 } 1062 1063 /* 1064 * Unknown option processing. 1065 * The third argument `off' is the offset from the IPv6 header to the option, 1066 * which is necessary if the IPv6 header the and option header and IPv6 header 1067 * is not continuous in order to return an ICMPv6 error. 1068 */ 1069 int 1070 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1071 { 1072 struct ip6_hdr *ip6; 1073 1074 switch (IP6OPT_TYPE(*optp)) { 1075 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1076 return ((int)*(optp + 1)); 1077 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1078 m_freem(m); 1079 return (-1); 1080 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1081 V_ip6stat.ip6s_badoptions++; 1082 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1083 return (-1); 1084 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1085 V_ip6stat.ip6s_badoptions++; 1086 ip6 = mtod(m, struct ip6_hdr *); 1087 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1088 (m->m_flags & (M_BCAST|M_MCAST))) 1089 m_freem(m); 1090 else 1091 icmp6_error(m, ICMP6_PARAM_PROB, 1092 ICMP6_PARAMPROB_OPTION, off); 1093 return (-1); 1094 } 1095 1096 m_freem(m); /* XXX: NOTREACHED */ 1097 return (-1); 1098 } 1099 1100 /* 1101 * Create the "control" list for this pcb. 1102 * These functions will not modify mbuf chain at all. 1103 * 1104 * With KAME mbuf chain restriction: 1105 * The routine will be called from upper layer handlers like tcp6_input(). 1106 * Thus the routine assumes that the caller (tcp6_input) have already 1107 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1108 * very first mbuf on the mbuf chain. 1109 * 1110 * ip6_savecontrol_v4 will handle those options that are possible to be 1111 * set on a v4-mapped socket. 1112 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1113 * options and handle the v6-only ones itself. 1114 */ 1115 struct mbuf ** 1116 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1117 int *v4only) 1118 { 1119 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1120 1121 #ifdef SO_TIMESTAMP 1122 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1123 struct timeval tv; 1124 1125 microtime(&tv); 1126 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1127 SCM_TIMESTAMP, SOL_SOCKET); 1128 if (*mp) 1129 mp = &(*mp)->m_next; 1130 } 1131 #endif 1132 1133 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1134 if (v4only != NULL) 1135 *v4only = 1; 1136 return (mp); 1137 } 1138 1139 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1140 /* RFC 2292 sec. 5 */ 1141 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1142 struct in6_pktinfo pi6; 1143 1144 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1145 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1146 pi6.ipi6_ifindex = 1147 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1148 1149 *mp = sbcreatecontrol((caddr_t) &pi6, 1150 sizeof(struct in6_pktinfo), 1151 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1152 if (*mp) 1153 mp = &(*mp)->m_next; 1154 } 1155 1156 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1157 int hlim = ip6->ip6_hlim & 0xff; 1158 1159 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1160 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1161 IPPROTO_IPV6); 1162 if (*mp) 1163 mp = &(*mp)->m_next; 1164 } 1165 1166 if (v4only != NULL) 1167 *v4only = 0; 1168 return (mp); 1169 } 1170 1171 void 1172 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1173 { 1174 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1175 int v4only = 0; 1176 1177 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1178 if (v4only) 1179 return; 1180 1181 if ((in6p->inp_flags & IN6P_TCLASS) != 0) { 1182 u_int32_t flowinfo; 1183 int tclass; 1184 1185 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1186 flowinfo >>= 20; 1187 1188 tclass = flowinfo & 0xff; 1189 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1190 IPV6_TCLASS, IPPROTO_IPV6); 1191 if (*mp) 1192 mp = &(*mp)->m_next; 1193 } 1194 1195 /* 1196 * IPV6_HOPOPTS socket option. Recall that we required super-user 1197 * privilege for the option (see ip6_ctloutput), but it might be too 1198 * strict, since there might be some hop-by-hop options which can be 1199 * returned to normal user. 1200 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1201 */ 1202 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1203 /* 1204 * Check if a hop-by-hop options header is contatined in the 1205 * received packet, and if so, store the options as ancillary 1206 * data. Note that a hop-by-hop options header must be 1207 * just after the IPv6 header, which is assured through the 1208 * IPv6 input processing. 1209 */ 1210 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1211 struct ip6_hbh *hbh; 1212 int hbhlen = 0; 1213 #ifdef PULLDOWN_TEST 1214 struct mbuf *ext; 1215 #endif 1216 1217 #ifndef PULLDOWN_TEST 1218 hbh = (struct ip6_hbh *)(ip6 + 1); 1219 hbhlen = (hbh->ip6h_len + 1) << 3; 1220 #else 1221 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1222 ip6->ip6_nxt); 1223 if (ext == NULL) { 1224 V_ip6stat.ip6s_tooshort++; 1225 return; 1226 } 1227 hbh = mtod(ext, struct ip6_hbh *); 1228 hbhlen = (hbh->ip6h_len + 1) << 3; 1229 if (hbhlen != ext->m_len) { 1230 m_freem(ext); 1231 V_ip6stat.ip6s_tooshort++; 1232 return; 1233 } 1234 #endif 1235 1236 /* 1237 * XXX: We copy the whole header even if a 1238 * jumbo payload option is included, the option which 1239 * is to be removed before returning according to 1240 * RFC2292. 1241 * Note: this constraint is removed in RFC3542 1242 */ 1243 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1244 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1245 IPPROTO_IPV6); 1246 if (*mp) 1247 mp = &(*mp)->m_next; 1248 #ifdef PULLDOWN_TEST 1249 m_freem(ext); 1250 #endif 1251 } 1252 } 1253 1254 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1255 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1256 1257 /* 1258 * Search for destination options headers or routing 1259 * header(s) through the header chain, and stores each 1260 * header as ancillary data. 1261 * Note that the order of the headers remains in 1262 * the chain of ancillary data. 1263 */ 1264 while (1) { /* is explicit loop prevention necessary? */ 1265 struct ip6_ext *ip6e = NULL; 1266 int elen; 1267 #ifdef PULLDOWN_TEST 1268 struct mbuf *ext = NULL; 1269 #endif 1270 1271 /* 1272 * if it is not an extension header, don't try to 1273 * pull it from the chain. 1274 */ 1275 switch (nxt) { 1276 case IPPROTO_DSTOPTS: 1277 case IPPROTO_ROUTING: 1278 case IPPROTO_HOPOPTS: 1279 case IPPROTO_AH: /* is it possible? */ 1280 break; 1281 default: 1282 goto loopend; 1283 } 1284 1285 #ifndef PULLDOWN_TEST 1286 if (off + sizeof(*ip6e) > m->m_len) 1287 goto loopend; 1288 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1289 if (nxt == IPPROTO_AH) 1290 elen = (ip6e->ip6e_len + 2) << 2; 1291 else 1292 elen = (ip6e->ip6e_len + 1) << 3; 1293 if (off + elen > m->m_len) 1294 goto loopend; 1295 #else 1296 ext = ip6_pullexthdr(m, off, nxt); 1297 if (ext == NULL) { 1298 V_ip6stat.ip6s_tooshort++; 1299 return; 1300 } 1301 ip6e = mtod(ext, struct ip6_ext *); 1302 if (nxt == IPPROTO_AH) 1303 elen = (ip6e->ip6e_len + 2) << 2; 1304 else 1305 elen = (ip6e->ip6e_len + 1) << 3; 1306 if (elen != ext->m_len) { 1307 m_freem(ext); 1308 V_ip6stat.ip6s_tooshort++; 1309 return; 1310 } 1311 #endif 1312 1313 switch (nxt) { 1314 case IPPROTO_DSTOPTS: 1315 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1316 break; 1317 1318 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1319 IS2292(in6p, 1320 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1321 IPPROTO_IPV6); 1322 if (*mp) 1323 mp = &(*mp)->m_next; 1324 break; 1325 case IPPROTO_ROUTING: 1326 if (!(in6p->inp_flags & IN6P_RTHDR)) 1327 break; 1328 1329 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1330 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1331 IPPROTO_IPV6); 1332 if (*mp) 1333 mp = &(*mp)->m_next; 1334 break; 1335 case IPPROTO_HOPOPTS: 1336 case IPPROTO_AH: /* is it possible? */ 1337 break; 1338 1339 default: 1340 /* 1341 * other cases have been filtered in the above. 1342 * none will visit this case. here we supply 1343 * the code just in case (nxt overwritten or 1344 * other cases). 1345 */ 1346 #ifdef PULLDOWN_TEST 1347 m_freem(ext); 1348 #endif 1349 goto loopend; 1350 1351 } 1352 1353 /* proceed with the next header. */ 1354 off += elen; 1355 nxt = ip6e->ip6e_nxt; 1356 ip6e = NULL; 1357 #ifdef PULLDOWN_TEST 1358 m_freem(ext); 1359 ext = NULL; 1360 #endif 1361 } 1362 loopend: 1363 ; 1364 } 1365 } 1366 #undef IS2292 1367 1368 void 1369 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1370 { 1371 struct socket *so; 1372 struct mbuf *m_mtu; 1373 struct ip6_mtuinfo mtuctl; 1374 1375 so = in6p->inp_socket; 1376 1377 if (mtu == NULL) 1378 return; 1379 1380 #ifdef DIAGNOSTIC 1381 if (so == NULL) /* I believe this is impossible */ 1382 panic("ip6_notify_pmtu: socket is NULL"); 1383 #endif 1384 1385 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1386 mtuctl.ip6m_mtu = *mtu; 1387 mtuctl.ip6m_addr = *dst; 1388 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1389 return; 1390 1391 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1392 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1393 return; 1394 1395 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1396 == 0) { 1397 m_freem(m_mtu); 1398 /* XXX: should count statistics */ 1399 } else 1400 sorwakeup(so); 1401 1402 return; 1403 } 1404 1405 #ifdef PULLDOWN_TEST 1406 /* 1407 * pull single extension header from mbuf chain. returns single mbuf that 1408 * contains the result, or NULL on error. 1409 */ 1410 static struct mbuf * 1411 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1412 { 1413 struct ip6_ext ip6e; 1414 size_t elen; 1415 struct mbuf *n; 1416 1417 #ifdef DIAGNOSTIC 1418 switch (nxt) { 1419 case IPPROTO_DSTOPTS: 1420 case IPPROTO_ROUTING: 1421 case IPPROTO_HOPOPTS: 1422 case IPPROTO_AH: /* is it possible? */ 1423 break; 1424 default: 1425 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1426 } 1427 #endif 1428 1429 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1430 if (nxt == IPPROTO_AH) 1431 elen = (ip6e.ip6e_len + 2) << 2; 1432 else 1433 elen = (ip6e.ip6e_len + 1) << 3; 1434 1435 MGET(n, M_DONTWAIT, MT_DATA); 1436 if (n && elen >= MLEN) { 1437 MCLGET(n, M_DONTWAIT); 1438 if ((n->m_flags & M_EXT) == 0) { 1439 m_free(n); 1440 n = NULL; 1441 } 1442 } 1443 if (!n) 1444 return NULL; 1445 1446 n->m_len = 0; 1447 if (elen >= M_TRAILINGSPACE(n)) { 1448 m_free(n); 1449 return NULL; 1450 } 1451 1452 m_copydata(m, off, elen, mtod(n, caddr_t)); 1453 n->m_len = elen; 1454 return n; 1455 } 1456 #endif 1457 1458 /* 1459 * Get pointer to the previous header followed by the header 1460 * currently processed. 1461 * XXX: This function supposes that 1462 * M includes all headers, 1463 * the next header field and the header length field of each header 1464 * are valid, and 1465 * the sum of each header length equals to OFF. 1466 * Because of these assumptions, this function must be called very 1467 * carefully. Moreover, it will not be used in the near future when 1468 * we develop `neater' mechanism to process extension headers. 1469 */ 1470 char * 1471 ip6_get_prevhdr(struct mbuf *m, int off) 1472 { 1473 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1474 1475 if (off == sizeof(struct ip6_hdr)) 1476 return (&ip6->ip6_nxt); 1477 else { 1478 int len, nxt; 1479 struct ip6_ext *ip6e = NULL; 1480 1481 nxt = ip6->ip6_nxt; 1482 len = sizeof(struct ip6_hdr); 1483 while (len < off) { 1484 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1485 1486 switch (nxt) { 1487 case IPPROTO_FRAGMENT: 1488 len += sizeof(struct ip6_frag); 1489 break; 1490 case IPPROTO_AH: 1491 len += (ip6e->ip6e_len + 2) << 2; 1492 break; 1493 default: 1494 len += (ip6e->ip6e_len + 1) << 3; 1495 break; 1496 } 1497 nxt = ip6e->ip6e_nxt; 1498 } 1499 if (ip6e) 1500 return (&ip6e->ip6e_nxt); 1501 else 1502 return NULL; 1503 } 1504 } 1505 1506 /* 1507 * get next header offset. m will be retained. 1508 */ 1509 int 1510 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1511 { 1512 struct ip6_hdr ip6; 1513 struct ip6_ext ip6e; 1514 struct ip6_frag fh; 1515 1516 /* just in case */ 1517 if (m == NULL) 1518 panic("ip6_nexthdr: m == NULL"); 1519 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1520 return -1; 1521 1522 switch (proto) { 1523 case IPPROTO_IPV6: 1524 if (m->m_pkthdr.len < off + sizeof(ip6)) 1525 return -1; 1526 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1527 if (nxtp) 1528 *nxtp = ip6.ip6_nxt; 1529 off += sizeof(ip6); 1530 return off; 1531 1532 case IPPROTO_FRAGMENT: 1533 /* 1534 * terminate parsing if it is not the first fragment, 1535 * it does not make sense to parse through it. 1536 */ 1537 if (m->m_pkthdr.len < off + sizeof(fh)) 1538 return -1; 1539 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1540 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1541 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1542 return -1; 1543 if (nxtp) 1544 *nxtp = fh.ip6f_nxt; 1545 off += sizeof(struct ip6_frag); 1546 return off; 1547 1548 case IPPROTO_AH: 1549 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1550 return -1; 1551 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1552 if (nxtp) 1553 *nxtp = ip6e.ip6e_nxt; 1554 off += (ip6e.ip6e_len + 2) << 2; 1555 return off; 1556 1557 case IPPROTO_HOPOPTS: 1558 case IPPROTO_ROUTING: 1559 case IPPROTO_DSTOPTS: 1560 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1561 return -1; 1562 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1563 if (nxtp) 1564 *nxtp = ip6e.ip6e_nxt; 1565 off += (ip6e.ip6e_len + 1) << 3; 1566 return off; 1567 1568 case IPPROTO_NONE: 1569 case IPPROTO_ESP: 1570 case IPPROTO_IPCOMP: 1571 /* give up */ 1572 return -1; 1573 1574 default: 1575 return -1; 1576 } 1577 1578 return -1; 1579 } 1580 1581 /* 1582 * get offset for the last header in the chain. m will be kept untainted. 1583 */ 1584 int 1585 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1586 { 1587 int newoff; 1588 int nxt; 1589 1590 if (!nxtp) { 1591 nxt = -1; 1592 nxtp = &nxt; 1593 } 1594 while (1) { 1595 newoff = ip6_nexthdr(m, off, proto, nxtp); 1596 if (newoff < 0) 1597 return off; 1598 else if (newoff < off) 1599 return -1; /* invalid */ 1600 else if (newoff == off) 1601 return newoff; 1602 1603 off = newoff; 1604 proto = *nxtp; 1605 } 1606 } 1607 1608 struct ip6aux * 1609 ip6_addaux(struct mbuf *m) 1610 { 1611 struct m_tag *mtag; 1612 1613 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1614 if (!mtag) { 1615 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1616 M_NOWAIT); 1617 if (mtag) { 1618 m_tag_prepend(m, mtag); 1619 bzero(mtag + 1, sizeof(struct ip6aux)); 1620 } 1621 } 1622 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1623 } 1624 1625 struct ip6aux * 1626 ip6_findaux(struct mbuf *m) 1627 { 1628 struct m_tag *mtag; 1629 1630 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1631 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1632 } 1633 1634 void 1635 ip6_delaux(struct mbuf *m) 1636 { 1637 struct m_tag *mtag; 1638 1639 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1640 if (mtag) 1641 m_tag_delete(m, mtag); 1642 } 1643 1644 /* 1645 * System control for IP6 1646 */ 1647 1648 u_char inet6ctlerrmap[PRC_NCMDS] = { 1649 0, 0, 0, 0, 1650 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1651 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1652 EMSGSIZE, EHOSTUNREACH, 0, 0, 1653 0, 0, 0, 0, 1654 ENOPROTOOPT 1655 }; 1656