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 #include "opt_route.h" 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/malloc.h> 74 #include <sys/mbuf.h> 75 #include <sys/proc.h> 76 #include <sys/domain.h> 77 #include <sys/protosw.h> 78 #include <sys/socket.h> 79 #include <sys/socketvar.h> 80 #include <sys/errno.h> 81 #include <sys/time.h> 82 #include <sys/kernel.h> 83 #include <sys/syslog.h> 84 85 #include <net/if.h> 86 #include <net/if_types.h> 87 #include <net/if_dl.h> 88 #include <net/route.h> 89 #include <net/netisr.h> 90 #include <net/pfil.h> 91 #include <net/vnet.h> 92 93 #include <netinet/in.h> 94 #include <netinet/in_systm.h> 95 #include <net/if_llatbl.h> 96 #ifdef INET 97 #include <netinet/ip.h> 98 #include <netinet/ip_icmp.h> 99 #endif /* INET */ 100 #include <netinet/ip6.h> 101 #include <netinet6/in6_var.h> 102 #include <netinet6/ip6_var.h> 103 #include <netinet/in_pcb.h> 104 #include <netinet/icmp6.h> 105 #include <netinet6/scope6_var.h> 106 #include <netinet6/in6_ifattach.h> 107 #include <netinet6/nd6.h> 108 109 #ifdef IPSEC 110 #include <netipsec/ipsec.h> 111 #include <netinet6/ip6_ipsec.h> 112 #include <netipsec/ipsec6.h> 113 #endif /* IPSEC */ 114 115 #include <netinet6/ip6protosw.h> 116 117 #ifdef FLOWTABLE 118 #include <net/flowtable.h> 119 VNET_DECLARE(int, ip6_output_flowtable_size); 120 #define V_ip6_output_flowtable_size VNET(ip6_output_flowtable_size) 121 #endif 122 123 extern struct domain inet6domain; 124 125 u_char ip6_protox[IPPROTO_MAX]; 126 VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead); 127 128 static struct netisr_handler ip6_nh = { 129 .nh_name = "ip6", 130 .nh_handler = ip6_input, 131 .nh_proto = NETISR_IPV6, 132 .nh_policy = NETISR_POLICY_FLOW, 133 }; 134 135 VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch); 136 #define V_in6_tmpaddrtimer_ch VNET(in6_tmpaddrtimer_ch) 137 138 VNET_DEFINE(struct pfil_head, inet6_pfil_hook); 139 140 VNET_DEFINE(struct ip6stat, ip6stat); 141 142 struct rwlock in6_ifaddr_lock; 143 RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock"); 144 145 static void ip6_init2(void *); 146 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 147 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 148 #ifdef PULLDOWN_TEST 149 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 150 #endif 151 152 /* 153 * IP6 initialization: fill in IP6 protocol switch table. 154 * All protocols not implemented in kernel go to raw IP6 protocol handler. 155 */ 156 void 157 ip6_init(void) 158 { 159 struct ip6protosw *pr; 160 int i; 161 162 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal", 163 &V_ip6_auto_linklocal); 164 165 TAILQ_INIT(&V_in6_ifaddrhead); 166 167 /* Initialize packet filter hooks. */ 168 V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 169 V_inet6_pfil_hook.ph_af = AF_INET6; 170 if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0) 171 printf("%s: WARNING: unable to register pfil hook, " 172 "error %d\n", __func__, i); 173 174 scope6_init(); 175 addrsel_policy_init(); 176 nd6_init(); 177 frag6_init(); 178 179 #ifdef FLOWTABLE 180 if (TUNABLE_INT_FETCH("net.inet6.ip6.output_flowtable_size", 181 &V_ip6_output_flowtable_size)) { 182 if (V_ip6_output_flowtable_size < 256) 183 V_ip6_output_flowtable_size = 256; 184 if (!powerof2(V_ip6_output_flowtable_size)) { 185 printf("flowtable must be power of 2 size\n"); 186 V_ip6_output_flowtable_size = 2048; 187 } 188 } else { 189 /* 190 * round up to the next power of 2 191 */ 192 V_ip6_output_flowtable_size = 1 << fls((1024 + maxusers * 64)-1); 193 } 194 V_ip6_ft = flowtable_alloc("ipv6", V_ip6_output_flowtable_size, FL_IPV6|FL_PCPU); 195 #endif 196 197 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 198 199 /* Skip global initialization stuff for non-default instances. */ 200 if (!IS_DEFAULT_VNET(curvnet)) 201 return; 202 203 #ifdef DIAGNOSTIC 204 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 205 panic("sizeof(protosw) != sizeof(ip6protosw)"); 206 #endif 207 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 208 if (pr == NULL) 209 panic("ip6_init"); 210 211 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ 212 for (i = 0; i < IPPROTO_MAX; i++) 213 ip6_protox[i] = pr - inet6sw; 214 /* 215 * Cycle through IP protocols and put them into the appropriate place 216 * in ip6_protox[]. 217 */ 218 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 219 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 220 if (pr->pr_domain->dom_family == PF_INET6 && 221 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 222 /* Be careful to only index valid IP protocols. */ 223 if (pr->pr_protocol < IPPROTO_MAX) 224 ip6_protox[pr->pr_protocol] = pr - inet6sw; 225 } 226 227 netisr_register(&ip6_nh); 228 } 229 230 #ifdef VIMAGE 231 void 232 ip6_destroy() 233 { 234 235 nd6_destroy(); 236 callout_drain(&V_in6_tmpaddrtimer_ch); 237 } 238 #endif 239 240 static int 241 ip6_init2_vnet(const void *unused __unused) 242 { 243 244 /* nd6_timer_init */ 245 callout_init(&V_nd6_timer_ch, 0); 246 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet); 247 248 /* timer for regeneranation of temporary addresses randomize ID */ 249 callout_init(&V_in6_tmpaddrtimer_ch, 0); 250 callout_reset(&V_in6_tmpaddrtimer_ch, 251 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor - 252 V_ip6_temp_regen_advance) * hz, 253 in6_tmpaddrtimer, curvnet); 254 255 return (0); 256 } 257 258 static void 259 ip6_init2(void *dummy) 260 { 261 262 ip6_init2_vnet(NULL); 263 } 264 265 /* cheat */ 266 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 267 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 268 269 void 270 ip6_input(struct mbuf *m) 271 { 272 struct ip6_hdr *ip6; 273 int off = sizeof(struct ip6_hdr), nest; 274 u_int32_t plen; 275 u_int32_t rtalert = ~0; 276 int nxt, ours = 0; 277 struct ifnet *deliverifp = NULL, *ifp = NULL; 278 struct in6_addr odst; 279 struct route_in6 rin6; 280 int srcrt = 0; 281 struct llentry *lle = NULL; 282 struct sockaddr_in6 dst6, *dst; 283 284 bzero(&rin6, sizeof(struct route_in6)); 285 #ifdef IPSEC 286 /* 287 * should the inner packet be considered authentic? 288 * see comment in ah4_input(). 289 * NB: m cannot be NULL when passed to the input routine 290 */ 291 292 m->m_flags &= ~M_AUTHIPHDR; 293 m->m_flags &= ~M_AUTHIPDGM; 294 295 #endif /* IPSEC */ 296 297 /* 298 * make sure we don't have onion peering information into m_tag. 299 */ 300 ip6_delaux(m); 301 302 /* 303 * mbuf statistics 304 */ 305 if (m->m_flags & M_EXT) { 306 if (m->m_next) 307 V_ip6stat.ip6s_mext2m++; 308 else 309 V_ip6stat.ip6s_mext1++; 310 } else { 311 #define M2MMAX (sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0])) 312 if (m->m_next) { 313 if (m->m_flags & M_LOOP) { 314 V_ip6stat.ip6s_m2m[V_loif->if_index]++; 315 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 316 V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 317 else 318 V_ip6stat.ip6s_m2m[0]++; 319 } else 320 V_ip6stat.ip6s_m1++; 321 #undef M2MMAX 322 } 323 324 /* drop the packet if IPv6 operation is disabled on the IF */ 325 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 326 m_freem(m); 327 return; 328 } 329 330 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 331 V_ip6stat.ip6s_total++; 332 333 #ifndef PULLDOWN_TEST 334 /* 335 * L2 bridge code and some other code can return mbuf chain 336 * that does not conform to KAME requirement. too bad. 337 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 338 */ 339 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 340 struct mbuf *n; 341 342 MGETHDR(n, M_DONTWAIT, MT_HEADER); 343 if (n) 344 M_MOVE_PKTHDR(n, m); 345 if (n && n->m_pkthdr.len > MHLEN) { 346 MCLGET(n, M_DONTWAIT); 347 if ((n->m_flags & M_EXT) == 0) { 348 m_freem(n); 349 n = NULL; 350 } 351 } 352 if (n == NULL) { 353 m_freem(m); 354 return; /* ENOBUFS */ 355 } 356 357 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 358 n->m_len = n->m_pkthdr.len; 359 m_freem(m); 360 m = n; 361 } 362 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 363 #endif 364 365 if (m->m_len < sizeof(struct ip6_hdr)) { 366 struct ifnet *inifp; 367 inifp = m->m_pkthdr.rcvif; 368 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 369 V_ip6stat.ip6s_toosmall++; 370 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 371 return; 372 } 373 } 374 375 ip6 = mtod(m, struct ip6_hdr *); 376 377 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 378 V_ip6stat.ip6s_badvers++; 379 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 380 goto bad; 381 } 382 383 V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 384 385 /* 386 * Check against address spoofing/corruption. 387 */ 388 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 389 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 390 /* 391 * XXX: "badscope" is not very suitable for a multicast source. 392 */ 393 V_ip6stat.ip6s_badscope++; 394 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 395 goto bad; 396 } 397 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 398 !(m->m_flags & M_LOOP)) { 399 /* 400 * In this case, the packet should come from the loopback 401 * interface. However, we cannot just check the if_flags, 402 * because ip6_mloopback() passes the "actual" interface 403 * as the outgoing/incoming interface. 404 */ 405 V_ip6stat.ip6s_badscope++; 406 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 407 goto bad; 408 } 409 410 #ifdef ALTQ 411 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 412 /* packet is dropped by traffic conditioner */ 413 return; 414 } 415 #endif 416 /* 417 * The following check is not documented in specs. A malicious 418 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 419 * and bypass security checks (act as if it was from 127.0.0.1 by using 420 * IPv6 src ::ffff:127.0.0.1). Be cautious. 421 * 422 * This check chokes if we are in an SIIT cloud. As none of BSDs 423 * support IPv4-less kernel compilation, we cannot support SIIT 424 * environment at all. So, it makes more sense for us to reject any 425 * malicious packets for non-SIIT environment, than try to do a 426 * partial support for SIIT environment. 427 */ 428 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 429 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 430 V_ip6stat.ip6s_badscope++; 431 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 432 goto bad; 433 } 434 #if 0 435 /* 436 * Reject packets with IPv4 compatible addresses (auto tunnel). 437 * 438 * The code forbids auto tunnel relay case in RFC1933 (the check is 439 * stronger than RFC1933). We may want to re-enable it if mech-xx 440 * is revised to forbid relaying case. 441 */ 442 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 443 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 444 V_ip6stat.ip6s_badscope++; 445 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 446 goto bad; 447 } 448 #endif 449 450 /* 451 * Run through list of hooks for input packets. 452 * 453 * NB: Beware of the destination address changing 454 * (e.g. by NAT rewriting). When this happens, 455 * tell ip6_forward to do the right thing. 456 */ 457 odst = ip6->ip6_dst; 458 459 /* Jump over all PFIL processing if hooks are not active. */ 460 if (!PFIL_HOOKED(&V_inet6_pfil_hook)) 461 goto passin; 462 463 if (pfil_run_hooks(&V_inet6_pfil_hook, &m, 464 m->m_pkthdr.rcvif, PFIL_IN, NULL)) 465 return; 466 if (m == NULL) /* consumed by filter */ 467 return; 468 ip6 = mtod(m, struct ip6_hdr *); 469 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 470 471 passin: 472 /* 473 * Disambiguate address scope zones (if there is ambiguity). 474 * We first make sure that the original source or destination address 475 * is not in our internal form for scoped addresses. Such addresses 476 * are not necessarily invalid spec-wise, but we cannot accept them due 477 * to the usage conflict. 478 * in6_setscope() then also checks and rejects the cases where src or 479 * dst are the loopback address and the receiving interface 480 * is not loopback. 481 */ 482 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 483 V_ip6stat.ip6s_badscope++; /* XXX */ 484 goto bad; 485 } 486 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 487 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 488 V_ip6stat.ip6s_badscope++; 489 goto bad; 490 } 491 492 /* 493 * Multicast check. Assume packet is for us to avoid 494 * prematurely taking locks. 495 */ 496 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 497 ours = 1; 498 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 499 deliverifp = m->m_pkthdr.rcvif; 500 goto hbhcheck; 501 } 502 503 /* 504 * Unicast check 505 */ 506 507 bzero(&dst6, sizeof(dst6)); 508 dst6.sin6_family = AF_INET6; 509 dst6.sin6_len = sizeof(struct sockaddr_in6); 510 dst6.sin6_addr = ip6->ip6_dst; 511 ifp = m->m_pkthdr.rcvif; 512 IF_AFDATA_LOCK(ifp); 513 lle = lla_lookup(LLTABLE6(ifp), 0, 514 (struct sockaddr *)&dst6); 515 IF_AFDATA_UNLOCK(ifp); 516 if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) { 517 ours = 1; 518 deliverifp = ifp; 519 LLE_RUNLOCK(lle); 520 goto hbhcheck; 521 } 522 if (lle != NULL) 523 LLE_RUNLOCK(lle); 524 525 dst = &rin6.ro_dst; 526 dst->sin6_len = sizeof(struct sockaddr_in6); 527 dst->sin6_family = AF_INET6; 528 dst->sin6_addr = ip6->ip6_dst; 529 rin6.ro_rt = rtalloc1((struct sockaddr *)dst, 0, 0); 530 if (rin6.ro_rt) 531 RT_UNLOCK(rin6.ro_rt); 532 533 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 534 535 /* 536 * Accept the packet if the forwarding interface to the destination 537 * according to the routing table is the loopback interface, 538 * unless the associated route has a gateway. 539 * Note that this approach causes to accept a packet if there is a 540 * route to the loopback interface for the destination of the packet. 541 * But we think it's even useful in some situations, e.g. when using 542 * a special daemon which wants to intercept the packet. 543 * 544 * XXX: some OSes automatically make a cloned route for the destination 545 * of an outgoing packet. If the outgoing interface of the packet 546 * is a loopback one, the kernel would consider the packet to be 547 * accepted, even if we have no such address assinged on the interface. 548 * We check the cloned flag of the route entry to reject such cases, 549 * assuming that route entries for our own addresses are not made by 550 * cloning (it should be true because in6_addloop explicitly installs 551 * the host route). However, we might have to do an explicit check 552 * while it would be less efficient. Or, should we rather install a 553 * reject route for such a case? 554 */ 555 if (rin6.ro_rt && 556 (rin6.ro_rt->rt_flags & 557 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 558 #ifdef RTF_WASCLONED 559 !(rin6.ro_rt->rt_flags & RTF_WASCLONED) && 560 #endif 561 #ifdef RTF_CLONED 562 !(rin6.ro_rt->rt_flags & RTF_CLONED) && 563 #endif 564 #if 0 565 /* 566 * The check below is redundant since the comparison of 567 * the destination and the key of the rtentry has 568 * already done through looking up the routing table. 569 */ 570 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 571 &rt6_key(rin6.ro_rt)->sin6_addr) 572 #endif 573 rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) { 574 int free_ia6 = 0; 575 struct in6_ifaddr *ia6; 576 577 /* 578 * found the loopback route to the interface address 579 */ 580 if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) { 581 struct sockaddr_in6 dest6; 582 583 bzero(&dest6, sizeof(dest6)); 584 dest6.sin6_family = AF_INET6; 585 dest6.sin6_len = sizeof(dest6); 586 dest6.sin6_addr = ip6->ip6_dst; 587 ia6 = (struct in6_ifaddr *) 588 ifa_ifwithaddr((struct sockaddr *)&dest6); 589 if (ia6 == NULL) 590 goto bad; 591 free_ia6 = 1; 592 } 593 else 594 ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa; 595 596 /* 597 * record address information into m_tag. 598 */ 599 (void)ip6_setdstifaddr(m, ia6); 600 601 /* 602 * packets to a tentative, duplicated, or somehow invalid 603 * address must not be accepted. 604 */ 605 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 606 /* this address is ready */ 607 ours = 1; 608 deliverifp = ia6->ia_ifp; /* correct? */ 609 /* Count the packet in the ip address stats */ 610 ia6->ia_ifa.if_ipackets++; 611 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 612 if (ia6 != NULL && free_ia6 != 0) 613 ifa_free(&ia6->ia_ifa); 614 goto hbhcheck; 615 } else { 616 char ip6bufs[INET6_ADDRSTRLEN]; 617 char ip6bufd[INET6_ADDRSTRLEN]; 618 /* address is not ready, so discard the packet. */ 619 nd6log((LOG_INFO, 620 "ip6_input: packet to an unready address %s->%s\n", 621 ip6_sprintf(ip6bufs, &ip6->ip6_src), 622 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 623 624 if (ia6 != NULL && free_ia6 != 0) 625 ifa_free(&ia6->ia_ifa); 626 goto bad; 627 } 628 } 629 630 /* 631 * FAITH (Firewall Aided Internet Translator) 632 */ 633 if (V_ip6_keepfaith) { 634 if (rin6.ro_rt && rin6.ro_rt->rt_ifp && 635 rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) { 636 /* XXX do we need more sanity checks? */ 637 ours = 1; 638 deliverifp = rin6.ro_rt->rt_ifp; /* faith */ 639 goto hbhcheck; 640 } 641 } 642 643 /* 644 * Now there is no reason to process the packet if it's not our own 645 * and we're not a router. 646 */ 647 if (!V_ip6_forwarding) { 648 V_ip6stat.ip6s_cantforward++; 649 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 650 goto bad; 651 } 652 653 hbhcheck: 654 /* 655 * record address information into m_tag, if we don't have one yet. 656 * note that we are unable to record it, if the address is not listed 657 * as our interface address (e.g. multicast addresses, addresses 658 * within FAITH prefixes and such). 659 */ 660 if (deliverifp && !ip6_getdstifaddr(m)) { 661 struct in6_ifaddr *ia6; 662 663 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 664 if (ia6) { 665 if (!ip6_setdstifaddr(m, ia6)) { 666 /* 667 * XXX maybe we should drop the packet here, 668 * as we could not provide enough information 669 * to the upper layers. 670 */ 671 } 672 ifa_free(&ia6->ia_ifa); 673 } 674 } 675 676 /* 677 * Process Hop-by-Hop options header if it's contained. 678 * m may be modified in ip6_hopopts_input(). 679 * If a JumboPayload option is included, plen will also be modified. 680 */ 681 plen = (u_int32_t)ntohs(ip6->ip6_plen); 682 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 683 struct ip6_hbh *hbh; 684 685 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 686 #if 0 /*touches NULL pointer*/ 687 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 688 #endif 689 goto out; /* m have already been freed */ 690 } 691 692 /* adjust pointer */ 693 ip6 = mtod(m, struct ip6_hdr *); 694 695 /* 696 * if the payload length field is 0 and the next header field 697 * indicates Hop-by-Hop Options header, then a Jumbo Payload 698 * option MUST be included. 699 */ 700 if (ip6->ip6_plen == 0 && plen == 0) { 701 /* 702 * Note that if a valid jumbo payload option is 703 * contained, ip6_hopopts_input() must set a valid 704 * (non-zero) payload length to the variable plen. 705 */ 706 V_ip6stat.ip6s_badoptions++; 707 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 708 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 709 icmp6_error(m, ICMP6_PARAM_PROB, 710 ICMP6_PARAMPROB_HEADER, 711 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 712 goto out; 713 } 714 #ifndef PULLDOWN_TEST 715 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 716 hbh = (struct ip6_hbh *)(ip6 + 1); 717 #else 718 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 719 sizeof(struct ip6_hbh)); 720 if (hbh == NULL) { 721 V_ip6stat.ip6s_tooshort++; 722 goto out; 723 } 724 #endif 725 nxt = hbh->ip6h_nxt; 726 727 /* 728 * If we are acting as a router and the packet contains a 729 * router alert option, see if we know the option value. 730 * Currently, we only support the option value for MLD, in which 731 * case we should pass the packet to the multicast routing 732 * daemon. 733 */ 734 if (rtalert != ~0) { 735 switch (rtalert) { 736 case IP6OPT_RTALERT_MLD: 737 if (V_ip6_forwarding) 738 ours = 1; 739 break; 740 default: 741 /* 742 * RFC2711 requires unrecognized values must be 743 * silently ignored. 744 */ 745 break; 746 } 747 } 748 } else 749 nxt = ip6->ip6_nxt; 750 751 /* 752 * Check that the amount of data in the buffers 753 * is as at least much as the IPv6 header would have us expect. 754 * Trim mbufs if longer than we expect. 755 * Drop packet if shorter than we expect. 756 */ 757 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 758 V_ip6stat.ip6s_tooshort++; 759 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 760 goto bad; 761 } 762 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 763 if (m->m_len == m->m_pkthdr.len) { 764 m->m_len = sizeof(struct ip6_hdr) + plen; 765 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 766 } else 767 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 768 } 769 770 /* 771 * Forward if desirable. 772 */ 773 if (V_ip6_mrouter && 774 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 775 /* 776 * If we are acting as a multicast router, all 777 * incoming multicast packets are passed to the 778 * kernel-level multicast forwarding function. 779 * The packet is returned (relatively) intact; if 780 * ip6_mforward() returns a non-zero value, the packet 781 * must be discarded, else it may be accepted below. 782 * 783 * XXX TODO: Check hlim and multicast scope here to avoid 784 * unnecessarily calling into ip6_mforward(). 785 */ 786 if (ip6_mforward && 787 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 788 IP6STAT_INC(ip6s_cantforward); 789 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 790 goto bad; 791 } 792 } else if (!ours) { 793 ip6_forward(m, srcrt); 794 goto out; 795 } 796 797 ip6 = mtod(m, struct ip6_hdr *); 798 799 /* 800 * Malicious party may be able to use IPv4 mapped addr to confuse 801 * tcp/udp stack and bypass security checks (act as if it was from 802 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 803 * 804 * For SIIT end node behavior, you may want to disable the check. 805 * However, you will become vulnerable to attacks using IPv4 mapped 806 * source. 807 */ 808 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 809 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 810 V_ip6stat.ip6s_badscope++; 811 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 812 goto bad; 813 } 814 815 /* 816 * Tell launch routine the next header 817 */ 818 V_ip6stat.ip6s_delivered++; 819 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 820 nest = 0; 821 822 while (nxt != IPPROTO_DONE) { 823 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 824 V_ip6stat.ip6s_toomanyhdr++; 825 goto bad; 826 } 827 828 /* 829 * protection against faulty packet - there should be 830 * more sanity checks in header chain processing. 831 */ 832 if (m->m_pkthdr.len < off) { 833 V_ip6stat.ip6s_tooshort++; 834 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 835 goto bad; 836 } 837 838 #ifdef IPSEC 839 /* 840 * enforce IPsec policy checking if we are seeing last header. 841 * note that we do not visit this with protocols with pcb layer 842 * code - like udp/tcp/raw ip. 843 */ 844 if (ip6_ipsec_input(m, nxt)) 845 goto bad; 846 #endif /* IPSEC */ 847 848 /* 849 * Use mbuf flags to propagate Router Alert option to 850 * ICMPv6 layer, as hop-by-hop options have been stripped. 851 */ 852 if (nxt == IPPROTO_ICMPV6 && rtalert != ~0) 853 m->m_flags |= M_RTALERT_MLD; 854 855 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 856 } 857 goto out; 858 bad: 859 m_freem(m); 860 out: 861 if (rin6.ro_rt) 862 RTFREE(rin6.ro_rt); 863 } 864 865 /* 866 * set/grab in6_ifaddr correspond to IPv6 destination address. 867 * XXX backward compatibility wrapper 868 * 869 * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag, 870 * and then bump it when the tag is copied, and release it when the tag is 871 * freed. Unfortunately, m_tags don't support deep copies (yet), so instead 872 * we just bump the ia refcount when we receive it. This should be fixed. 873 */ 874 static struct ip6aux * 875 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 876 { 877 struct ip6aux *ip6a; 878 879 ip6a = ip6_addaux(m); 880 if (ip6a) 881 ip6a->ip6a_dstia6 = ia6; 882 return ip6a; /* NULL if failed to set */ 883 } 884 885 struct in6_ifaddr * 886 ip6_getdstifaddr(struct mbuf *m) 887 { 888 struct ip6aux *ip6a; 889 struct in6_ifaddr *ia; 890 891 ip6a = ip6_findaux(m); 892 if (ip6a) { 893 ia = ip6a->ip6a_dstia6; 894 ifa_ref(&ia->ia_ifa); 895 return ia; 896 } else 897 return NULL; 898 } 899 900 /* 901 * Hop-by-Hop options header processing. If a valid jumbo payload option is 902 * included, the real payload length will be stored in plenp. 903 * 904 * rtalertp - XXX: should be stored more smart way 905 */ 906 static int 907 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 908 struct mbuf **mp, int *offp) 909 { 910 struct mbuf *m = *mp; 911 int off = *offp, hbhlen; 912 struct ip6_hbh *hbh; 913 u_int8_t *opt; 914 915 /* validation of the length of the header */ 916 #ifndef PULLDOWN_TEST 917 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 918 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 919 hbhlen = (hbh->ip6h_len + 1) << 3; 920 921 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 922 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 923 #else 924 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 925 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 926 if (hbh == NULL) { 927 V_ip6stat.ip6s_tooshort++; 928 return -1; 929 } 930 hbhlen = (hbh->ip6h_len + 1) << 3; 931 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 932 hbhlen); 933 if (hbh == NULL) { 934 V_ip6stat.ip6s_tooshort++; 935 return -1; 936 } 937 #endif 938 off += hbhlen; 939 hbhlen -= sizeof(struct ip6_hbh); 940 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 941 942 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 943 hbhlen, rtalertp, plenp) < 0) 944 return (-1); 945 946 *offp = off; 947 *mp = m; 948 return (0); 949 } 950 951 /* 952 * Search header for all Hop-by-hop options and process each option. 953 * This function is separate from ip6_hopopts_input() in order to 954 * handle a case where the sending node itself process its hop-by-hop 955 * options header. In such a case, the function is called from ip6_output(). 956 * 957 * The function assumes that hbh header is located right after the IPv6 header 958 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 959 * opthead + hbhlen is located in continuous memory region. 960 */ 961 int 962 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 963 u_int32_t *rtalertp, u_int32_t *plenp) 964 { 965 struct ip6_hdr *ip6; 966 int optlen = 0; 967 u_int8_t *opt = opthead; 968 u_int16_t rtalert_val; 969 u_int32_t jumboplen; 970 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 971 972 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 973 switch (*opt) { 974 case IP6OPT_PAD1: 975 optlen = 1; 976 break; 977 case IP6OPT_PADN: 978 if (hbhlen < IP6OPT_MINLEN) { 979 V_ip6stat.ip6s_toosmall++; 980 goto bad; 981 } 982 optlen = *(opt + 1) + 2; 983 break; 984 case IP6OPT_ROUTER_ALERT: 985 /* XXX may need check for alignment */ 986 if (hbhlen < IP6OPT_RTALERT_LEN) { 987 V_ip6stat.ip6s_toosmall++; 988 goto bad; 989 } 990 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 991 /* XXX stat */ 992 icmp6_error(m, ICMP6_PARAM_PROB, 993 ICMP6_PARAMPROB_HEADER, 994 erroff + opt + 1 - opthead); 995 return (-1); 996 } 997 optlen = IP6OPT_RTALERT_LEN; 998 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 999 *rtalertp = ntohs(rtalert_val); 1000 break; 1001 case IP6OPT_JUMBO: 1002 /* XXX may need check for alignment */ 1003 if (hbhlen < IP6OPT_JUMBO_LEN) { 1004 V_ip6stat.ip6s_toosmall++; 1005 goto bad; 1006 } 1007 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1008 /* XXX stat */ 1009 icmp6_error(m, ICMP6_PARAM_PROB, 1010 ICMP6_PARAMPROB_HEADER, 1011 erroff + opt + 1 - opthead); 1012 return (-1); 1013 } 1014 optlen = IP6OPT_JUMBO_LEN; 1015 1016 /* 1017 * IPv6 packets that have non 0 payload length 1018 * must not contain a jumbo payload option. 1019 */ 1020 ip6 = mtod(m, struct ip6_hdr *); 1021 if (ip6->ip6_plen) { 1022 V_ip6stat.ip6s_badoptions++; 1023 icmp6_error(m, ICMP6_PARAM_PROB, 1024 ICMP6_PARAMPROB_HEADER, 1025 erroff + opt - opthead); 1026 return (-1); 1027 } 1028 1029 /* 1030 * We may see jumbolen in unaligned location, so 1031 * we'd need to perform bcopy(). 1032 */ 1033 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1034 jumboplen = (u_int32_t)htonl(jumboplen); 1035 1036 #if 1 1037 /* 1038 * if there are multiple jumbo payload options, 1039 * *plenp will be non-zero and the packet will be 1040 * rejected. 1041 * the behavior may need some debate in ipngwg - 1042 * multiple options does not make sense, however, 1043 * there's no explicit mention in specification. 1044 */ 1045 if (*plenp != 0) { 1046 V_ip6stat.ip6s_badoptions++; 1047 icmp6_error(m, ICMP6_PARAM_PROB, 1048 ICMP6_PARAMPROB_HEADER, 1049 erroff + opt + 2 - opthead); 1050 return (-1); 1051 } 1052 #endif 1053 1054 /* 1055 * jumbo payload length must be larger than 65535. 1056 */ 1057 if (jumboplen <= IPV6_MAXPACKET) { 1058 V_ip6stat.ip6s_badoptions++; 1059 icmp6_error(m, ICMP6_PARAM_PROB, 1060 ICMP6_PARAMPROB_HEADER, 1061 erroff + opt + 2 - opthead); 1062 return (-1); 1063 } 1064 *plenp = jumboplen; 1065 1066 break; 1067 default: /* unknown option */ 1068 if (hbhlen < IP6OPT_MINLEN) { 1069 V_ip6stat.ip6s_toosmall++; 1070 goto bad; 1071 } 1072 optlen = ip6_unknown_opt(opt, m, 1073 erroff + opt - opthead); 1074 if (optlen == -1) 1075 return (-1); 1076 optlen += 2; 1077 break; 1078 } 1079 } 1080 1081 return (0); 1082 1083 bad: 1084 m_freem(m); 1085 return (-1); 1086 } 1087 1088 /* 1089 * Unknown option processing. 1090 * The third argument `off' is the offset from the IPv6 header to the option, 1091 * which is necessary if the IPv6 header the and option header and IPv6 header 1092 * is not continuous in order to return an ICMPv6 error. 1093 */ 1094 int 1095 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1096 { 1097 struct ip6_hdr *ip6; 1098 1099 switch (IP6OPT_TYPE(*optp)) { 1100 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1101 return ((int)*(optp + 1)); 1102 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1103 m_freem(m); 1104 return (-1); 1105 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1106 V_ip6stat.ip6s_badoptions++; 1107 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1108 return (-1); 1109 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1110 V_ip6stat.ip6s_badoptions++; 1111 ip6 = mtod(m, struct ip6_hdr *); 1112 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1113 (m->m_flags & (M_BCAST|M_MCAST))) 1114 m_freem(m); 1115 else 1116 icmp6_error(m, ICMP6_PARAM_PROB, 1117 ICMP6_PARAMPROB_OPTION, off); 1118 return (-1); 1119 } 1120 1121 m_freem(m); /* XXX: NOTREACHED */ 1122 return (-1); 1123 } 1124 1125 /* 1126 * Create the "control" list for this pcb. 1127 * These functions will not modify mbuf chain at all. 1128 * 1129 * With KAME mbuf chain restriction: 1130 * The routine will be called from upper layer handlers like tcp6_input(). 1131 * Thus the routine assumes that the caller (tcp6_input) have already 1132 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1133 * very first mbuf on the mbuf chain. 1134 * 1135 * ip6_savecontrol_v4 will handle those options that are possible to be 1136 * set on a v4-mapped socket. 1137 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1138 * options and handle the v6-only ones itself. 1139 */ 1140 struct mbuf ** 1141 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1142 int *v4only) 1143 { 1144 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1145 1146 #ifdef SO_TIMESTAMP 1147 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1148 struct timeval tv; 1149 1150 microtime(&tv); 1151 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1152 SCM_TIMESTAMP, SOL_SOCKET); 1153 if (*mp) 1154 mp = &(*mp)->m_next; 1155 } 1156 #endif 1157 1158 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1159 if (v4only != NULL) 1160 *v4only = 1; 1161 return (mp); 1162 } 1163 1164 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1165 /* RFC 2292 sec. 5 */ 1166 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1167 struct in6_pktinfo pi6; 1168 1169 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1170 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1171 pi6.ipi6_ifindex = 1172 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1173 1174 *mp = sbcreatecontrol((caddr_t) &pi6, 1175 sizeof(struct in6_pktinfo), 1176 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1177 if (*mp) 1178 mp = &(*mp)->m_next; 1179 } 1180 1181 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1182 int hlim = ip6->ip6_hlim & 0xff; 1183 1184 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1185 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1186 IPPROTO_IPV6); 1187 if (*mp) 1188 mp = &(*mp)->m_next; 1189 } 1190 1191 if (v4only != NULL) 1192 *v4only = 0; 1193 return (mp); 1194 } 1195 1196 void 1197 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1198 { 1199 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1200 int v4only = 0; 1201 1202 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1203 if (v4only) 1204 return; 1205 1206 if ((in6p->inp_flags & IN6P_TCLASS) != 0) { 1207 u_int32_t flowinfo; 1208 int tclass; 1209 1210 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1211 flowinfo >>= 20; 1212 1213 tclass = flowinfo & 0xff; 1214 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1215 IPV6_TCLASS, IPPROTO_IPV6); 1216 if (*mp) 1217 mp = &(*mp)->m_next; 1218 } 1219 1220 /* 1221 * IPV6_HOPOPTS socket option. Recall that we required super-user 1222 * privilege for the option (see ip6_ctloutput), but it might be too 1223 * strict, since there might be some hop-by-hop options which can be 1224 * returned to normal user. 1225 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1226 */ 1227 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1228 /* 1229 * Check if a hop-by-hop options header is contatined in the 1230 * received packet, and if so, store the options as ancillary 1231 * data. Note that a hop-by-hop options header must be 1232 * just after the IPv6 header, which is assured through the 1233 * IPv6 input processing. 1234 */ 1235 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1236 struct ip6_hbh *hbh; 1237 int hbhlen = 0; 1238 #ifdef PULLDOWN_TEST 1239 struct mbuf *ext; 1240 #endif 1241 1242 #ifndef PULLDOWN_TEST 1243 hbh = (struct ip6_hbh *)(ip6 + 1); 1244 hbhlen = (hbh->ip6h_len + 1) << 3; 1245 #else 1246 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1247 ip6->ip6_nxt); 1248 if (ext == NULL) { 1249 V_ip6stat.ip6s_tooshort++; 1250 return; 1251 } 1252 hbh = mtod(ext, struct ip6_hbh *); 1253 hbhlen = (hbh->ip6h_len + 1) << 3; 1254 if (hbhlen != ext->m_len) { 1255 m_freem(ext); 1256 V_ip6stat.ip6s_tooshort++; 1257 return; 1258 } 1259 #endif 1260 1261 /* 1262 * XXX: We copy the whole header even if a 1263 * jumbo payload option is included, the option which 1264 * is to be removed before returning according to 1265 * RFC2292. 1266 * Note: this constraint is removed in RFC3542 1267 */ 1268 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1269 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1270 IPPROTO_IPV6); 1271 if (*mp) 1272 mp = &(*mp)->m_next; 1273 #ifdef PULLDOWN_TEST 1274 m_freem(ext); 1275 #endif 1276 } 1277 } 1278 1279 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1280 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1281 1282 /* 1283 * Search for destination options headers or routing 1284 * header(s) through the header chain, and stores each 1285 * header as ancillary data. 1286 * Note that the order of the headers remains in 1287 * the chain of ancillary data. 1288 */ 1289 while (1) { /* is explicit loop prevention necessary? */ 1290 struct ip6_ext *ip6e = NULL; 1291 int elen; 1292 #ifdef PULLDOWN_TEST 1293 struct mbuf *ext = NULL; 1294 #endif 1295 1296 /* 1297 * if it is not an extension header, don't try to 1298 * pull it from the chain. 1299 */ 1300 switch (nxt) { 1301 case IPPROTO_DSTOPTS: 1302 case IPPROTO_ROUTING: 1303 case IPPROTO_HOPOPTS: 1304 case IPPROTO_AH: /* is it possible? */ 1305 break; 1306 default: 1307 goto loopend; 1308 } 1309 1310 #ifndef PULLDOWN_TEST 1311 if (off + sizeof(*ip6e) > m->m_len) 1312 goto loopend; 1313 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1314 if (nxt == IPPROTO_AH) 1315 elen = (ip6e->ip6e_len + 2) << 2; 1316 else 1317 elen = (ip6e->ip6e_len + 1) << 3; 1318 if (off + elen > m->m_len) 1319 goto loopend; 1320 #else 1321 ext = ip6_pullexthdr(m, off, nxt); 1322 if (ext == NULL) { 1323 V_ip6stat.ip6s_tooshort++; 1324 return; 1325 } 1326 ip6e = mtod(ext, struct ip6_ext *); 1327 if (nxt == IPPROTO_AH) 1328 elen = (ip6e->ip6e_len + 2) << 2; 1329 else 1330 elen = (ip6e->ip6e_len + 1) << 3; 1331 if (elen != ext->m_len) { 1332 m_freem(ext); 1333 V_ip6stat.ip6s_tooshort++; 1334 return; 1335 } 1336 #endif 1337 1338 switch (nxt) { 1339 case IPPROTO_DSTOPTS: 1340 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1341 break; 1342 1343 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1344 IS2292(in6p, 1345 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1346 IPPROTO_IPV6); 1347 if (*mp) 1348 mp = &(*mp)->m_next; 1349 break; 1350 case IPPROTO_ROUTING: 1351 if (!(in6p->inp_flags & IN6P_RTHDR)) 1352 break; 1353 1354 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1355 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1356 IPPROTO_IPV6); 1357 if (*mp) 1358 mp = &(*mp)->m_next; 1359 break; 1360 case IPPROTO_HOPOPTS: 1361 case IPPROTO_AH: /* is it possible? */ 1362 break; 1363 1364 default: 1365 /* 1366 * other cases have been filtered in the above. 1367 * none will visit this case. here we supply 1368 * the code just in case (nxt overwritten or 1369 * other cases). 1370 */ 1371 #ifdef PULLDOWN_TEST 1372 m_freem(ext); 1373 #endif 1374 goto loopend; 1375 1376 } 1377 1378 /* proceed with the next header. */ 1379 off += elen; 1380 nxt = ip6e->ip6e_nxt; 1381 ip6e = NULL; 1382 #ifdef PULLDOWN_TEST 1383 m_freem(ext); 1384 ext = NULL; 1385 #endif 1386 } 1387 loopend: 1388 ; 1389 } 1390 } 1391 #undef IS2292 1392 1393 void 1394 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1395 { 1396 struct socket *so; 1397 struct mbuf *m_mtu; 1398 struct ip6_mtuinfo mtuctl; 1399 1400 so = in6p->inp_socket; 1401 1402 if (mtu == NULL) 1403 return; 1404 1405 #ifdef DIAGNOSTIC 1406 if (so == NULL) /* I believe this is impossible */ 1407 panic("ip6_notify_pmtu: socket is NULL"); 1408 #endif 1409 1410 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1411 mtuctl.ip6m_mtu = *mtu; 1412 mtuctl.ip6m_addr = *dst; 1413 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1414 return; 1415 1416 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1417 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1418 return; 1419 1420 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1421 == 0) { 1422 m_freem(m_mtu); 1423 /* XXX: should count statistics */ 1424 } else 1425 sorwakeup(so); 1426 1427 return; 1428 } 1429 1430 #ifdef PULLDOWN_TEST 1431 /* 1432 * pull single extension header from mbuf chain. returns single mbuf that 1433 * contains the result, or NULL on error. 1434 */ 1435 static struct mbuf * 1436 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1437 { 1438 struct ip6_ext ip6e; 1439 size_t elen; 1440 struct mbuf *n; 1441 1442 #ifdef DIAGNOSTIC 1443 switch (nxt) { 1444 case IPPROTO_DSTOPTS: 1445 case IPPROTO_ROUTING: 1446 case IPPROTO_HOPOPTS: 1447 case IPPROTO_AH: /* is it possible? */ 1448 break; 1449 default: 1450 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1451 } 1452 #endif 1453 1454 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1455 if (nxt == IPPROTO_AH) 1456 elen = (ip6e.ip6e_len + 2) << 2; 1457 else 1458 elen = (ip6e.ip6e_len + 1) << 3; 1459 1460 MGET(n, M_DONTWAIT, MT_DATA); 1461 if (n && elen >= MLEN) { 1462 MCLGET(n, M_DONTWAIT); 1463 if ((n->m_flags & M_EXT) == 0) { 1464 m_free(n); 1465 n = NULL; 1466 } 1467 } 1468 if (!n) 1469 return NULL; 1470 1471 n->m_len = 0; 1472 if (elen >= M_TRAILINGSPACE(n)) { 1473 m_free(n); 1474 return NULL; 1475 } 1476 1477 m_copydata(m, off, elen, mtod(n, caddr_t)); 1478 n->m_len = elen; 1479 return n; 1480 } 1481 #endif 1482 1483 /* 1484 * Get pointer to the previous header followed by the header 1485 * currently processed. 1486 * XXX: This function supposes that 1487 * M includes all headers, 1488 * the next header field and the header length field of each header 1489 * are valid, and 1490 * the sum of each header length equals to OFF. 1491 * Because of these assumptions, this function must be called very 1492 * carefully. Moreover, it will not be used in the near future when 1493 * we develop `neater' mechanism to process extension headers. 1494 */ 1495 char * 1496 ip6_get_prevhdr(struct mbuf *m, int off) 1497 { 1498 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1499 1500 if (off == sizeof(struct ip6_hdr)) 1501 return (&ip6->ip6_nxt); 1502 else { 1503 int len, nxt; 1504 struct ip6_ext *ip6e = NULL; 1505 1506 nxt = ip6->ip6_nxt; 1507 len = sizeof(struct ip6_hdr); 1508 while (len < off) { 1509 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1510 1511 switch (nxt) { 1512 case IPPROTO_FRAGMENT: 1513 len += sizeof(struct ip6_frag); 1514 break; 1515 case IPPROTO_AH: 1516 len += (ip6e->ip6e_len + 2) << 2; 1517 break; 1518 default: 1519 len += (ip6e->ip6e_len + 1) << 3; 1520 break; 1521 } 1522 nxt = ip6e->ip6e_nxt; 1523 } 1524 if (ip6e) 1525 return (&ip6e->ip6e_nxt); 1526 else 1527 return NULL; 1528 } 1529 } 1530 1531 /* 1532 * get next header offset. m will be retained. 1533 */ 1534 int 1535 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1536 { 1537 struct ip6_hdr ip6; 1538 struct ip6_ext ip6e; 1539 struct ip6_frag fh; 1540 1541 /* just in case */ 1542 if (m == NULL) 1543 panic("ip6_nexthdr: m == NULL"); 1544 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1545 return -1; 1546 1547 switch (proto) { 1548 case IPPROTO_IPV6: 1549 if (m->m_pkthdr.len < off + sizeof(ip6)) 1550 return -1; 1551 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1552 if (nxtp) 1553 *nxtp = ip6.ip6_nxt; 1554 off += sizeof(ip6); 1555 return off; 1556 1557 case IPPROTO_FRAGMENT: 1558 /* 1559 * terminate parsing if it is not the first fragment, 1560 * it does not make sense to parse through it. 1561 */ 1562 if (m->m_pkthdr.len < off + sizeof(fh)) 1563 return -1; 1564 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1565 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1566 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1567 return -1; 1568 if (nxtp) 1569 *nxtp = fh.ip6f_nxt; 1570 off += sizeof(struct ip6_frag); 1571 return off; 1572 1573 case IPPROTO_AH: 1574 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1575 return -1; 1576 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1577 if (nxtp) 1578 *nxtp = ip6e.ip6e_nxt; 1579 off += (ip6e.ip6e_len + 2) << 2; 1580 return off; 1581 1582 case IPPROTO_HOPOPTS: 1583 case IPPROTO_ROUTING: 1584 case IPPROTO_DSTOPTS: 1585 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1586 return -1; 1587 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1588 if (nxtp) 1589 *nxtp = ip6e.ip6e_nxt; 1590 off += (ip6e.ip6e_len + 1) << 3; 1591 return off; 1592 1593 case IPPROTO_NONE: 1594 case IPPROTO_ESP: 1595 case IPPROTO_IPCOMP: 1596 /* give up */ 1597 return -1; 1598 1599 default: 1600 return -1; 1601 } 1602 1603 return -1; 1604 } 1605 1606 /* 1607 * get offset for the last header in the chain. m will be kept untainted. 1608 */ 1609 int 1610 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1611 { 1612 int newoff; 1613 int nxt; 1614 1615 if (!nxtp) { 1616 nxt = -1; 1617 nxtp = &nxt; 1618 } 1619 while (1) { 1620 newoff = ip6_nexthdr(m, off, proto, nxtp); 1621 if (newoff < 0) 1622 return off; 1623 else if (newoff < off) 1624 return -1; /* invalid */ 1625 else if (newoff == off) 1626 return newoff; 1627 1628 off = newoff; 1629 proto = *nxtp; 1630 } 1631 } 1632 1633 struct ip6aux * 1634 ip6_addaux(struct mbuf *m) 1635 { 1636 struct m_tag *mtag; 1637 1638 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1639 if (!mtag) { 1640 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1641 M_NOWAIT); 1642 if (mtag) { 1643 m_tag_prepend(m, mtag); 1644 bzero(mtag + 1, sizeof(struct ip6aux)); 1645 } 1646 } 1647 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1648 } 1649 1650 struct ip6aux * 1651 ip6_findaux(struct mbuf *m) 1652 { 1653 struct m_tag *mtag; 1654 1655 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1656 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1657 } 1658 1659 void 1660 ip6_delaux(struct mbuf *m) 1661 { 1662 struct m_tag *mtag; 1663 1664 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1665 if (mtag) 1666 m_tag_delete(m, mtag); 1667 } 1668 1669 /* 1670 * System control for IP6 1671 */ 1672 1673 u_char inet6ctlerrmap[PRC_NCMDS] = { 1674 0, 0, 0, 0, 1675 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1676 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1677 EMSGSIZE, EHOSTUNREACH, 0, 0, 1678 0, 0, 0, 0, 1679 ENOPROTOOPT 1680 }; 1681