ip6_input.c revision 196019
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: head/sys/netinet6/ip6_input.c 196019 2009-08-01 19:26:27Z rwatson $"); 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 116extern struct domain inet6domain; 117 118u_char ip6_protox[IPPROTO_MAX]; 119 120static struct netisr_handler ip6_nh = { 121 .nh_name = "ip6", 122 .nh_handler = ip6_input, 123 .nh_proto = NETISR_IPV6, 124 .nh_policy = NETISR_POLICY_FLOW, 125}; 126 127VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead); 128VNET_DEFINE(struct ip6stat, ip6stat); 129 130VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch); 131VNET_DECLARE(int, dad_init); 132VNET_DECLARE(int, pmtu_expire); 133VNET_DECLARE(int, pmtu_probe); 134VNET_DECLARE(u_long, rip6_sendspace); 135VNET_DECLARE(u_long, rip6_recvspace); 136VNET_DECLARE(int, icmp6errppslim); 137VNET_DECLARE(int, icmp6_nodeinfo); 138VNET_DECLARE(int, udp6_sendspace); 139VNET_DECLARE(int, udp6_recvspace); 140 141#define V_in6_tmpaddrtimer_ch VNET(in6_tmpaddrtimer_ch) 142#define V_dad_init VNET(dad_init) 143#define V_pmtu_expire VNET(pmtu_expire) 144#define V_pmtu_probe VNET(pmtu_probe) 145#define V_rip6_sendspace VNET(rip6_sendspace) 146#define V_rip6_recvspace VNET(rip6_recvspace) 147#define V_icmp6errppslim VNET(icmp6errppslim) 148#define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 149#define V_udp6_sendspace VNET(udp6_sendspace) 150#define V_udp6_recvspace VNET(udp6_recvspace) 151 152struct rwlock in6_ifaddr_lock; 153RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock"); 154 155struct pfil_head inet6_pfil_hook; 156 157static void ip6_init2(void *); 158static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 159static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 160#ifdef PULLDOWN_TEST 161static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 162#endif 163 164/* 165 * IP6 initialization: fill in IP6 protocol switch table. 166 * All protocols not implemented in kernel go to raw IP6 protocol handler. 167 */ 168void 169ip6_init(void) 170{ 171 struct ip6protosw *pr; 172 int i; 173 174 V_in6_maxmtu = 0; 175#ifdef IP6_AUTO_LINKLOCAL 176 V_ip6_auto_linklocal = IP6_AUTO_LINKLOCAL; 177#else 178 V_ip6_auto_linklocal = 1; /* enable by default */ 179#endif 180 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal", 181 &V_ip6_auto_linklocal); 182 183#ifndef IPV6FORWARDING 184#ifdef GATEWAY6 185#define IPV6FORWARDING 1 /* forward IP6 packets not for us */ 186#else 187#define IPV6FORWARDING 0 /* don't forward IP6 packets not for us */ 188#endif /* GATEWAY6 */ 189#endif /* !IPV6FORWARDING */ 190 191#ifndef IPV6_SENDREDIRECTS 192#define IPV6_SENDREDIRECTS 1 193#endif 194 195 V_ip6_forwarding = IPV6FORWARDING; /* act as router? */ 196 V_ip6_sendredirects = IPV6_SENDREDIRECTS; 197 V_ip6_defhlim = IPV6_DEFHLIM; 198 V_ip6_defmcasthlim = IPV6_DEFAULT_MULTICAST_HOPS; 199 V_ip6_accept_rtadv = 0; /* "IPV6FORWARDING ? 0 : 1" is dangerous */ 200 V_ip6_log_interval = 5; 201 V_ip6_hdrnestlimit = 15; /* How many header options will we process? */ 202 V_ip6_dad_count = 1; /* DupAddrDetectionTransmits */ 203 V_ip6_auto_flowlabel = 1; 204 V_ip6_use_deprecated = 1;/* allow deprecated addr (RFC2462 5.5.4) */ 205 V_ip6_rr_prune = 5; /* router renumbering prefix 206 * walk list every 5 sec. */ 207 V_ip6_mcast_pmtu = 0; /* enable pMTU discovery for multicast? */ 208 V_ip6_v6only = 1; 209 V_ip6_keepfaith = 0; 210 V_ip6_log_time = (time_t)0L; 211#ifdef IPSTEALTH 212 V_ip6stealth = 0; 213#endif 214 V_nd6_onlink_ns_rfc4861 = 0; /* allow 'on-link' nd6 NS (RFC 4861) */ 215 216 V_pmtu_expire = 60*10; 217 V_pmtu_probe = 60*2; 218 219 /* raw IP6 parameters */ 220 /* 221 * Nominal space allocated to a raw ip socket. 222 */ 223#define RIPV6SNDQ 8192 224#define RIPV6RCVQ 8192 225 V_rip6_sendspace = RIPV6SNDQ; 226 V_rip6_recvspace = RIPV6RCVQ; 227 228 /* ICMPV6 parameters */ 229 V_icmp6_rediraccept = 1; /* accept and process redirects */ 230 V_icmp6_redirtimeout = 10 * 60; /* 10 minutes */ 231 V_icmp6errppslim = 100; /* 100pps */ 232 /* control how to respond to NI queries */ 233 V_icmp6_nodeinfo = (ICMP6_NODEINFO_FQDNOK|ICMP6_NODEINFO_NODEADDROK); 234 235 /* UDP on IP6 parameters */ 236 V_udp6_sendspace = 9216; /* really max datagram size */ 237 V_udp6_recvspace = 40 * (1024 + sizeof(struct sockaddr_in6)); 238 /* 40 1K datagrams */ 239 V_dad_init = 0; 240 241 TAILQ_INIT(&V_in6_ifaddrhead); 242 243 scope6_init(); 244 addrsel_policy_init(); 245 nd6_init(); 246 frag6_init(); 247 248 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 249 250 /* Skip global initialization stuff for non-default instances. */ 251 if (!IS_DEFAULT_VNET(curvnet)) 252 return; 253 254#ifdef DIAGNOSTIC 255 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 256 panic("sizeof(protosw) != sizeof(ip6protosw)"); 257#endif 258 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 259 if (pr == NULL) 260 panic("ip6_init"); 261 262 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ 263 for (i = 0; i < IPPROTO_MAX; i++) 264 ip6_protox[i] = pr - inet6sw; 265 /* 266 * Cycle through IP protocols and put them into the appropriate place 267 * in ip6_protox[]. 268 */ 269 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 270 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 271 if (pr->pr_domain->dom_family == PF_INET6 && 272 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 273 /* Be careful to only index valid IP protocols. */ 274 if (pr->pr_protocol < IPPROTO_MAX) 275 ip6_protox[pr->pr_protocol] = pr - inet6sw; 276 } 277 278 /* Initialize packet filter hooks. */ 279 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 280 inet6_pfil_hook.ph_af = AF_INET6; 281 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 282 printf("%s: WARNING: unable to register pfil hook, " 283 "error %d\n", __func__, i); 284 285 netisr_register(&ip6_nh); 286} 287 288#ifdef VIMAGE 289void 290ip6_destroy() 291{ 292 293 nd6_destroy(); 294 callout_drain(&V_in6_tmpaddrtimer_ch); 295} 296#endif 297 298static int 299ip6_init2_vnet(const void *unused __unused) 300{ 301 302 /* nd6_timer_init */ 303 callout_init(&V_nd6_timer_ch, 0); 304 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet); 305 306 /* timer for regeneranation of temporary addresses randomize ID */ 307 callout_init(&V_in6_tmpaddrtimer_ch, 0); 308 callout_reset(&V_in6_tmpaddrtimer_ch, 309 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor - 310 V_ip6_temp_regen_advance) * hz, 311 in6_tmpaddrtimer, curvnet); 312 313 return (0); 314} 315 316static void 317ip6_init2(void *dummy) 318{ 319 320 ip6_init2_vnet(NULL); 321} 322 323/* cheat */ 324/* This must be after route_init(), which is now SI_ORDER_THIRD */ 325SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 326 327void 328ip6_input(struct mbuf *m) 329{ 330 struct ip6_hdr *ip6; 331 int off = sizeof(struct ip6_hdr), nest; 332 u_int32_t plen; 333 u_int32_t rtalert = ~0; 334 int nxt, ours = 0; 335 struct ifnet *deliverifp = NULL, *ifp = NULL; 336 struct in6_addr odst; 337 struct route_in6 rin6; 338 int srcrt = 0; 339 struct llentry *lle = NULL; 340 struct sockaddr_in6 dst6, *dst; 341 342 bzero(&rin6, sizeof(struct route_in6)); 343#ifdef IPSEC 344 /* 345 * should the inner packet be considered authentic? 346 * see comment in ah4_input(). 347 * NB: m cannot be NULL when passed to the input routine 348 */ 349 350 m->m_flags &= ~M_AUTHIPHDR; 351 m->m_flags &= ~M_AUTHIPDGM; 352 353#endif /* IPSEC */ 354 355 /* 356 * make sure we don't have onion peering information into m_tag. 357 */ 358 ip6_delaux(m); 359 360 /* 361 * mbuf statistics 362 */ 363 if (m->m_flags & M_EXT) { 364 if (m->m_next) 365 V_ip6stat.ip6s_mext2m++; 366 else 367 V_ip6stat.ip6s_mext1++; 368 } else { 369#define M2MMAX (sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0])) 370 if (m->m_next) { 371 if (m->m_flags & M_LOOP) { 372 V_ip6stat.ip6s_m2m[V_loif->if_index]++; 373 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 374 V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 375 else 376 V_ip6stat.ip6s_m2m[0]++; 377 } else 378 V_ip6stat.ip6s_m1++; 379#undef M2MMAX 380 } 381 382 /* drop the packet if IPv6 operation is disabled on the IF */ 383 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 384 m_freem(m); 385 return; 386 } 387 388 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 389 V_ip6stat.ip6s_total++; 390 391#ifndef PULLDOWN_TEST 392 /* 393 * L2 bridge code and some other code can return mbuf chain 394 * that does not conform to KAME requirement. too bad. 395 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 396 */ 397 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 398 struct mbuf *n; 399 400 MGETHDR(n, M_DONTWAIT, MT_HEADER); 401 if (n) 402 M_MOVE_PKTHDR(n, m); 403 if (n && n->m_pkthdr.len > MHLEN) { 404 MCLGET(n, M_DONTWAIT); 405 if ((n->m_flags & M_EXT) == 0) { 406 m_freem(n); 407 n = NULL; 408 } 409 } 410 if (n == NULL) { 411 m_freem(m); 412 return; /* ENOBUFS */ 413 } 414 415 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 416 n->m_len = n->m_pkthdr.len; 417 m_freem(m); 418 m = n; 419 } 420 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 421#endif 422 423 if (m->m_len < sizeof(struct ip6_hdr)) { 424 struct ifnet *inifp; 425 inifp = m->m_pkthdr.rcvif; 426 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 427 V_ip6stat.ip6s_toosmall++; 428 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 429 return; 430 } 431 } 432 433 ip6 = mtod(m, struct ip6_hdr *); 434 435 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 436 V_ip6stat.ip6s_badvers++; 437 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 438 goto bad; 439 } 440 441 V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 442 443 /* 444 * Check against address spoofing/corruption. 445 */ 446 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 447 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 448 /* 449 * XXX: "badscope" is not very suitable for a multicast source. 450 */ 451 V_ip6stat.ip6s_badscope++; 452 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 453 goto bad; 454 } 455 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 456 !(m->m_flags & M_LOOP)) { 457 /* 458 * In this case, the packet should come from the loopback 459 * interface. However, we cannot just check the if_flags, 460 * because ip6_mloopback() passes the "actual" interface 461 * as the outgoing/incoming interface. 462 */ 463 V_ip6stat.ip6s_badscope++; 464 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 465 goto bad; 466 } 467 468#ifdef ALTQ 469 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 470 /* packet is dropped by traffic conditioner */ 471 return; 472 } 473#endif 474 /* 475 * The following check is not documented in specs. A malicious 476 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 477 * and bypass security checks (act as if it was from 127.0.0.1 by using 478 * IPv6 src ::ffff:127.0.0.1). Be cautious. 479 * 480 * This check chokes if we are in an SIIT cloud. As none of BSDs 481 * support IPv4-less kernel compilation, we cannot support SIIT 482 * environment at all. So, it makes more sense for us to reject any 483 * malicious packets for non-SIIT environment, than try to do a 484 * partial support for SIIT environment. 485 */ 486 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 487 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 488 V_ip6stat.ip6s_badscope++; 489 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 490 goto bad; 491 } 492#if 0 493 /* 494 * Reject packets with IPv4 compatible addresses (auto tunnel). 495 * 496 * The code forbids auto tunnel relay case in RFC1933 (the check is 497 * stronger than RFC1933). We may want to re-enable it if mech-xx 498 * is revised to forbid relaying case. 499 */ 500 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 501 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 502 V_ip6stat.ip6s_badscope++; 503 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 504 goto bad; 505 } 506#endif 507 508 /* 509 * Run through list of hooks for input packets. 510 * 511 * NB: Beware of the destination address changing 512 * (e.g. by NAT rewriting). When this happens, 513 * tell ip6_forward to do the right thing. 514 */ 515 odst = ip6->ip6_dst; 516 517 /* Jump over all PFIL processing if hooks are not active. */ 518 if (!PFIL_HOOKED(&inet6_pfil_hook)) 519 goto passin; 520 521 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 522 return; 523 if (m == NULL) /* consumed by filter */ 524 return; 525 ip6 = mtod(m, struct ip6_hdr *); 526 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 527 528passin: 529 /* 530 * Disambiguate address scope zones (if there is ambiguity). 531 * We first make sure that the original source or destination address 532 * is not in our internal form for scoped addresses. Such addresses 533 * are not necessarily invalid spec-wise, but we cannot accept them due 534 * to the usage conflict. 535 * in6_setscope() then also checks and rejects the cases where src or 536 * dst are the loopback address and the receiving interface 537 * is not loopback. 538 */ 539 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 540 V_ip6stat.ip6s_badscope++; /* XXX */ 541 goto bad; 542 } 543 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 544 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 545 V_ip6stat.ip6s_badscope++; 546 goto bad; 547 } 548 549 /* 550 * Multicast check. Assume packet is for us to avoid 551 * prematurely taking locks. 552 */ 553 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 554 ours = 1; 555 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 556 deliverifp = m->m_pkthdr.rcvif; 557 goto hbhcheck; 558 } 559 560 /* 561 * Unicast check 562 */ 563 564 bzero(&dst6, sizeof(dst6)); 565 dst6.sin6_family = AF_INET6; 566 dst6.sin6_len = sizeof(struct sockaddr_in6); 567 dst6.sin6_addr = ip6->ip6_dst; 568 ifp = m->m_pkthdr.rcvif; 569 IF_AFDATA_LOCK(ifp); 570 lle = lla_lookup(LLTABLE6(ifp), 0, 571 (struct sockaddr *)&dst6); 572 IF_AFDATA_UNLOCK(ifp); 573 if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) { 574 ours = 1; 575 deliverifp = ifp; 576 LLE_RUNLOCK(lle); 577 goto hbhcheck; 578 } 579 if (lle != NULL) 580 LLE_RUNLOCK(lle); 581 582 dst = &rin6.ro_dst; 583 dst->sin6_len = sizeof(struct sockaddr_in6); 584 dst->sin6_family = AF_INET6; 585 dst->sin6_addr = ip6->ip6_dst; 586 rin6.ro_rt = rtalloc1((struct sockaddr *)dst, 0, 0); 587 if (rin6.ro_rt) 588 RT_UNLOCK(rin6.ro_rt); 589 590#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 591 592 /* 593 * Accept the packet if the forwarding interface to the destination 594 * according to the routing table is the loopback interface, 595 * unless the associated route has a gateway. 596 * Note that this approach causes to accept a packet if there is a 597 * route to the loopback interface for the destination of the packet. 598 * But we think it's even useful in some situations, e.g. when using 599 * a special daemon which wants to intercept the packet. 600 * 601 * XXX: some OSes automatically make a cloned route for the destination 602 * of an outgoing packet. If the outgoing interface of the packet 603 * is a loopback one, the kernel would consider the packet to be 604 * accepted, even if we have no such address assinged on the interface. 605 * We check the cloned flag of the route entry to reject such cases, 606 * assuming that route entries for our own addresses are not made by 607 * cloning (it should be true because in6_addloop explicitly installs 608 * the host route). However, we might have to do an explicit check 609 * while it would be less efficient. Or, should we rather install a 610 * reject route for such a case? 611 */ 612 if (rin6.ro_rt && 613 (rin6.ro_rt->rt_flags & 614 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 615#ifdef RTF_WASCLONED 616 !(rin6.ro_rt->rt_flags & RTF_WASCLONED) && 617#endif 618#ifdef RTF_CLONED 619 !(rin6.ro_rt->rt_flags & RTF_CLONED) && 620#endif 621#if 0 622 /* 623 * The check below is redundant since the comparison of 624 * the destination and the key of the rtentry has 625 * already done through looking up the routing table. 626 */ 627 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 628 &rt6_key(rin6.ro_rt)->sin6_addr) 629#endif 630 rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) { 631 struct in6_ifaddr *ia6 = 632 (struct in6_ifaddr *)rin6.ro_rt->rt_ifa; 633 634 /* 635 * record address information into m_tag. 636 */ 637 (void)ip6_setdstifaddr(m, ia6); 638 639 /* 640 * packets to a tentative, duplicated, or somehow invalid 641 * address must not be accepted. 642 */ 643 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 644 /* this address is ready */ 645 ours = 1; 646 deliverifp = ia6->ia_ifp; /* correct? */ 647 /* Count the packet in the ip address stats */ 648 ia6->ia_ifa.if_ipackets++; 649 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 650 goto hbhcheck; 651 } else { 652 char ip6bufs[INET6_ADDRSTRLEN]; 653 char ip6bufd[INET6_ADDRSTRLEN]; 654 /* address is not ready, so discard the packet. */ 655 nd6log((LOG_INFO, 656 "ip6_input: packet to an unready address %s->%s\n", 657 ip6_sprintf(ip6bufs, &ip6->ip6_src), 658 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 659 660 goto bad; 661 } 662 } 663 664 /* 665 * FAITH (Firewall Aided Internet Translator) 666 */ 667 if (V_ip6_keepfaith) { 668 if (rin6.ro_rt && rin6.ro_rt->rt_ifp && 669 rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) { 670 /* XXX do we need more sanity checks? */ 671 ours = 1; 672 deliverifp = rin6.ro_rt->rt_ifp; /* faith */ 673 goto hbhcheck; 674 } 675 } 676 677 /* 678 * Now there is no reason to process the packet if it's not our own 679 * and we're not a router. 680 */ 681 if (!V_ip6_forwarding) { 682 V_ip6stat.ip6s_cantforward++; 683 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 684 goto bad; 685 } 686 687 hbhcheck: 688 /* 689 * record address information into m_tag, if we don't have one yet. 690 * note that we are unable to record it, if the address is not listed 691 * as our interface address (e.g. multicast addresses, addresses 692 * within FAITH prefixes and such). 693 */ 694 if (deliverifp && !ip6_getdstifaddr(m)) { 695 struct in6_ifaddr *ia6; 696 697 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 698 if (ia6) { 699 if (!ip6_setdstifaddr(m, ia6)) { 700 /* 701 * XXX maybe we should drop the packet here, 702 * as we could not provide enough information 703 * to the upper layers. 704 */ 705 } 706 ifa_free(&ia6->ia_ifa); 707 } 708 } 709 710 /* 711 * Process Hop-by-Hop options header if it's contained. 712 * m may be modified in ip6_hopopts_input(). 713 * If a JumboPayload option is included, plen will also be modified. 714 */ 715 plen = (u_int32_t)ntohs(ip6->ip6_plen); 716 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 717 struct ip6_hbh *hbh; 718 719 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 720#if 0 /*touches NULL pointer*/ 721 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 722#endif 723 goto out; /* m have already been freed */ 724 } 725 726 /* adjust pointer */ 727 ip6 = mtod(m, struct ip6_hdr *); 728 729 /* 730 * if the payload length field is 0 and the next header field 731 * indicates Hop-by-Hop Options header, then a Jumbo Payload 732 * option MUST be included. 733 */ 734 if (ip6->ip6_plen == 0 && plen == 0) { 735 /* 736 * Note that if a valid jumbo payload option is 737 * contained, ip6_hopopts_input() must set a valid 738 * (non-zero) payload length to the variable plen. 739 */ 740 V_ip6stat.ip6s_badoptions++; 741 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 742 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 743 icmp6_error(m, ICMP6_PARAM_PROB, 744 ICMP6_PARAMPROB_HEADER, 745 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 746 goto out; 747 } 748#ifndef PULLDOWN_TEST 749 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 750 hbh = (struct ip6_hbh *)(ip6 + 1); 751#else 752 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 753 sizeof(struct ip6_hbh)); 754 if (hbh == NULL) { 755 V_ip6stat.ip6s_tooshort++; 756 goto out; 757 } 758#endif 759 nxt = hbh->ip6h_nxt; 760 761 /* 762 * If we are acting as a router and the packet contains a 763 * router alert option, see if we know the option value. 764 * Currently, we only support the option value for MLD, in which 765 * case we should pass the packet to the multicast routing 766 * daemon. 767 */ 768 if (rtalert != ~0) { 769 switch (rtalert) { 770 case IP6OPT_RTALERT_MLD: 771 if (V_ip6_forwarding) 772 ours = 1; 773 break; 774 default: 775 /* 776 * RFC2711 requires unrecognized values must be 777 * silently ignored. 778 */ 779 break; 780 } 781 } 782 } else 783 nxt = ip6->ip6_nxt; 784 785 /* 786 * Check that the amount of data in the buffers 787 * is as at least much as the IPv6 header would have us expect. 788 * Trim mbufs if longer than we expect. 789 * Drop packet if shorter than we expect. 790 */ 791 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 792 V_ip6stat.ip6s_tooshort++; 793 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 794 goto bad; 795 } 796 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 797 if (m->m_len == m->m_pkthdr.len) { 798 m->m_len = sizeof(struct ip6_hdr) + plen; 799 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 800 } else 801 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 802 } 803 804 /* 805 * Forward if desirable. 806 */ 807 if (V_ip6_mrouter && 808 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 809 /* 810 * If we are acting as a multicast router, all 811 * incoming multicast packets are passed to the 812 * kernel-level multicast forwarding function. 813 * The packet is returned (relatively) intact; if 814 * ip6_mforward() returns a non-zero value, the packet 815 * must be discarded, else it may be accepted below. 816 * 817 * XXX TODO: Check hlim and multicast scope here to avoid 818 * unnecessarily calling into ip6_mforward(). 819 */ 820 if (ip6_mforward && 821 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 822 IP6STAT_INC(ip6s_cantforward); 823 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 824 goto bad; 825 } 826 } else if (!ours) { 827 ip6_forward(m, srcrt); 828 goto out; 829 } 830 831 ip6 = mtod(m, struct ip6_hdr *); 832 833 /* 834 * Malicious party may be able to use IPv4 mapped addr to confuse 835 * tcp/udp stack and bypass security checks (act as if it was from 836 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 837 * 838 * For SIIT end node behavior, you may want to disable the check. 839 * However, you will become vulnerable to attacks using IPv4 mapped 840 * source. 841 */ 842 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 843 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 844 V_ip6stat.ip6s_badscope++; 845 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 846 goto bad; 847 } 848 849 /* 850 * Tell launch routine the next header 851 */ 852 V_ip6stat.ip6s_delivered++; 853 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 854 nest = 0; 855 856 while (nxt != IPPROTO_DONE) { 857 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 858 V_ip6stat.ip6s_toomanyhdr++; 859 goto bad; 860 } 861 862 /* 863 * protection against faulty packet - there should be 864 * more sanity checks in header chain processing. 865 */ 866 if (m->m_pkthdr.len < off) { 867 V_ip6stat.ip6s_tooshort++; 868 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 869 goto bad; 870 } 871 872#ifdef IPSEC 873 /* 874 * enforce IPsec policy checking if we are seeing last header. 875 * note that we do not visit this with protocols with pcb layer 876 * code - like udp/tcp/raw ip. 877 */ 878 if (ip6_ipsec_input(m, nxt)) 879 goto bad; 880#endif /* IPSEC */ 881 882 /* 883 * Use mbuf flags to propagate Router Alert option to 884 * ICMPv6 layer, as hop-by-hop options have been stripped. 885 */ 886 if (nxt == IPPROTO_ICMPV6 && rtalert != ~0) 887 m->m_flags |= M_RTALERT_MLD; 888 889 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 890 } 891 goto out; 892bad: 893 m_freem(m); 894out: 895 if (rin6.ro_rt) 896 RTFREE(rin6.ro_rt); 897} 898 899/* 900 * set/grab in6_ifaddr correspond to IPv6 destination address. 901 * XXX backward compatibility wrapper 902 * 903 * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag, 904 * and then bump it when the tag is copied, and release it when the tag is 905 * freed. Unfortunately, m_tags don't support deep copies (yet), so instead 906 * we just bump the ia refcount when we receive it. This should be fixed. 907 */ 908static struct ip6aux * 909ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 910{ 911 struct ip6aux *ip6a; 912 913 ip6a = ip6_addaux(m); 914 if (ip6a) 915 ip6a->ip6a_dstia6 = ia6; 916 return ip6a; /* NULL if failed to set */ 917} 918 919struct in6_ifaddr * 920ip6_getdstifaddr(struct mbuf *m) 921{ 922 struct ip6aux *ip6a; 923 struct in6_ifaddr *ia; 924 925 ip6a = ip6_findaux(m); 926 if (ip6a) { 927 ia = ip6a->ip6a_dstia6; 928 ifa_ref(&ia->ia_ifa); 929 return ia; 930 } else 931 return NULL; 932} 933 934/* 935 * Hop-by-Hop options header processing. If a valid jumbo payload option is 936 * included, the real payload length will be stored in plenp. 937 * 938 * rtalertp - XXX: should be stored more smart way 939 */ 940static int 941ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 942 struct mbuf **mp, int *offp) 943{ 944 struct mbuf *m = *mp; 945 int off = *offp, hbhlen; 946 struct ip6_hbh *hbh; 947 u_int8_t *opt; 948 949 /* validation of the length of the header */ 950#ifndef PULLDOWN_TEST 951 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 952 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 953 hbhlen = (hbh->ip6h_len + 1) << 3; 954 955 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 956 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 957#else 958 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 959 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 960 if (hbh == NULL) { 961 V_ip6stat.ip6s_tooshort++; 962 return -1; 963 } 964 hbhlen = (hbh->ip6h_len + 1) << 3; 965 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 966 hbhlen); 967 if (hbh == NULL) { 968 V_ip6stat.ip6s_tooshort++; 969 return -1; 970 } 971#endif 972 off += hbhlen; 973 hbhlen -= sizeof(struct ip6_hbh); 974 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 975 976 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 977 hbhlen, rtalertp, plenp) < 0) 978 return (-1); 979 980 *offp = off; 981 *mp = m; 982 return (0); 983} 984 985/* 986 * Search header for all Hop-by-hop options and process each option. 987 * This function is separate from ip6_hopopts_input() in order to 988 * handle a case where the sending node itself process its hop-by-hop 989 * options header. In such a case, the function is called from ip6_output(). 990 * 991 * The function assumes that hbh header is located right after the IPv6 header 992 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 993 * opthead + hbhlen is located in continuous memory region. 994 */ 995int 996ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 997 u_int32_t *rtalertp, u_int32_t *plenp) 998{ 999 struct ip6_hdr *ip6; 1000 int optlen = 0; 1001 u_int8_t *opt = opthead; 1002 u_int16_t rtalert_val; 1003 u_int32_t jumboplen; 1004 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 1005 1006 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 1007 switch (*opt) { 1008 case IP6OPT_PAD1: 1009 optlen = 1; 1010 break; 1011 case IP6OPT_PADN: 1012 if (hbhlen < IP6OPT_MINLEN) { 1013 V_ip6stat.ip6s_toosmall++; 1014 goto bad; 1015 } 1016 optlen = *(opt + 1) + 2; 1017 break; 1018 case IP6OPT_ROUTER_ALERT: 1019 /* XXX may need check for alignment */ 1020 if (hbhlen < IP6OPT_RTALERT_LEN) { 1021 V_ip6stat.ip6s_toosmall++; 1022 goto bad; 1023 } 1024 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 1025 /* XXX stat */ 1026 icmp6_error(m, ICMP6_PARAM_PROB, 1027 ICMP6_PARAMPROB_HEADER, 1028 erroff + opt + 1 - opthead); 1029 return (-1); 1030 } 1031 optlen = IP6OPT_RTALERT_LEN; 1032 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 1033 *rtalertp = ntohs(rtalert_val); 1034 break; 1035 case IP6OPT_JUMBO: 1036 /* XXX may need check for alignment */ 1037 if (hbhlen < IP6OPT_JUMBO_LEN) { 1038 V_ip6stat.ip6s_toosmall++; 1039 goto bad; 1040 } 1041 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1042 /* XXX stat */ 1043 icmp6_error(m, ICMP6_PARAM_PROB, 1044 ICMP6_PARAMPROB_HEADER, 1045 erroff + opt + 1 - opthead); 1046 return (-1); 1047 } 1048 optlen = IP6OPT_JUMBO_LEN; 1049 1050 /* 1051 * IPv6 packets that have non 0 payload length 1052 * must not contain a jumbo payload option. 1053 */ 1054 ip6 = mtod(m, struct ip6_hdr *); 1055 if (ip6->ip6_plen) { 1056 V_ip6stat.ip6s_badoptions++; 1057 icmp6_error(m, ICMP6_PARAM_PROB, 1058 ICMP6_PARAMPROB_HEADER, 1059 erroff + opt - opthead); 1060 return (-1); 1061 } 1062 1063 /* 1064 * We may see jumbolen in unaligned location, so 1065 * we'd need to perform bcopy(). 1066 */ 1067 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1068 jumboplen = (u_int32_t)htonl(jumboplen); 1069 1070#if 1 1071 /* 1072 * if there are multiple jumbo payload options, 1073 * *plenp will be non-zero and the packet will be 1074 * rejected. 1075 * the behavior may need some debate in ipngwg - 1076 * multiple options does not make sense, however, 1077 * there's no explicit mention in specification. 1078 */ 1079 if (*plenp != 0) { 1080 V_ip6stat.ip6s_badoptions++; 1081 icmp6_error(m, ICMP6_PARAM_PROB, 1082 ICMP6_PARAMPROB_HEADER, 1083 erroff + opt + 2 - opthead); 1084 return (-1); 1085 } 1086#endif 1087 1088 /* 1089 * jumbo payload length must be larger than 65535. 1090 */ 1091 if (jumboplen <= IPV6_MAXPACKET) { 1092 V_ip6stat.ip6s_badoptions++; 1093 icmp6_error(m, ICMP6_PARAM_PROB, 1094 ICMP6_PARAMPROB_HEADER, 1095 erroff + opt + 2 - opthead); 1096 return (-1); 1097 } 1098 *plenp = jumboplen; 1099 1100 break; 1101 default: /* unknown option */ 1102 if (hbhlen < IP6OPT_MINLEN) { 1103 V_ip6stat.ip6s_toosmall++; 1104 goto bad; 1105 } 1106 optlen = ip6_unknown_opt(opt, m, 1107 erroff + opt - opthead); 1108 if (optlen == -1) 1109 return (-1); 1110 optlen += 2; 1111 break; 1112 } 1113 } 1114 1115 return (0); 1116 1117 bad: 1118 m_freem(m); 1119 return (-1); 1120} 1121 1122/* 1123 * Unknown option processing. 1124 * The third argument `off' is the offset from the IPv6 header to the option, 1125 * which is necessary if the IPv6 header the and option header and IPv6 header 1126 * is not continuous in order to return an ICMPv6 error. 1127 */ 1128int 1129ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1130{ 1131 struct ip6_hdr *ip6; 1132 1133 switch (IP6OPT_TYPE(*optp)) { 1134 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1135 return ((int)*(optp + 1)); 1136 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1137 m_freem(m); 1138 return (-1); 1139 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1140 V_ip6stat.ip6s_badoptions++; 1141 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1142 return (-1); 1143 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1144 V_ip6stat.ip6s_badoptions++; 1145 ip6 = mtod(m, struct ip6_hdr *); 1146 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1147 (m->m_flags & (M_BCAST|M_MCAST))) 1148 m_freem(m); 1149 else 1150 icmp6_error(m, ICMP6_PARAM_PROB, 1151 ICMP6_PARAMPROB_OPTION, off); 1152 return (-1); 1153 } 1154 1155 m_freem(m); /* XXX: NOTREACHED */ 1156 return (-1); 1157} 1158 1159/* 1160 * Create the "control" list for this pcb. 1161 * These functions will not modify mbuf chain at all. 1162 * 1163 * With KAME mbuf chain restriction: 1164 * The routine will be called from upper layer handlers like tcp6_input(). 1165 * Thus the routine assumes that the caller (tcp6_input) have already 1166 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1167 * very first mbuf on the mbuf chain. 1168 * 1169 * ip6_savecontrol_v4 will handle those options that are possible to be 1170 * set on a v4-mapped socket. 1171 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1172 * options and handle the v6-only ones itself. 1173 */ 1174struct mbuf ** 1175ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1176 int *v4only) 1177{ 1178 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1179 1180#ifdef SO_TIMESTAMP 1181 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1182 struct timeval tv; 1183 1184 microtime(&tv); 1185 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1186 SCM_TIMESTAMP, SOL_SOCKET); 1187 if (*mp) 1188 mp = &(*mp)->m_next; 1189 } 1190#endif 1191 1192 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1193 if (v4only != NULL) 1194 *v4only = 1; 1195 return (mp); 1196 } 1197 1198#define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1199 /* RFC 2292 sec. 5 */ 1200 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1201 struct in6_pktinfo pi6; 1202 1203 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1204 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1205 pi6.ipi6_ifindex = 1206 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1207 1208 *mp = sbcreatecontrol((caddr_t) &pi6, 1209 sizeof(struct in6_pktinfo), 1210 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1211 if (*mp) 1212 mp = &(*mp)->m_next; 1213 } 1214 1215 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1216 int hlim = ip6->ip6_hlim & 0xff; 1217 1218 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1219 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1220 IPPROTO_IPV6); 1221 if (*mp) 1222 mp = &(*mp)->m_next; 1223 } 1224 1225 if (v4only != NULL) 1226 *v4only = 0; 1227 return (mp); 1228} 1229 1230void 1231ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1232{ 1233 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1234 int v4only = 0; 1235 1236 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1237 if (v4only) 1238 return; 1239 1240 if ((in6p->inp_flags & IN6P_TCLASS) != 0) { 1241 u_int32_t flowinfo; 1242 int tclass; 1243 1244 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1245 flowinfo >>= 20; 1246 1247 tclass = flowinfo & 0xff; 1248 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1249 IPV6_TCLASS, IPPROTO_IPV6); 1250 if (*mp) 1251 mp = &(*mp)->m_next; 1252 } 1253 1254 /* 1255 * IPV6_HOPOPTS socket option. Recall that we required super-user 1256 * privilege for the option (see ip6_ctloutput), but it might be too 1257 * strict, since there might be some hop-by-hop options which can be 1258 * returned to normal user. 1259 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1260 */ 1261 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1262 /* 1263 * Check if a hop-by-hop options header is contatined in the 1264 * received packet, and if so, store the options as ancillary 1265 * data. Note that a hop-by-hop options header must be 1266 * just after the IPv6 header, which is assured through the 1267 * IPv6 input processing. 1268 */ 1269 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1270 struct ip6_hbh *hbh; 1271 int hbhlen = 0; 1272#ifdef PULLDOWN_TEST 1273 struct mbuf *ext; 1274#endif 1275 1276#ifndef PULLDOWN_TEST 1277 hbh = (struct ip6_hbh *)(ip6 + 1); 1278 hbhlen = (hbh->ip6h_len + 1) << 3; 1279#else 1280 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1281 ip6->ip6_nxt); 1282 if (ext == NULL) { 1283 V_ip6stat.ip6s_tooshort++; 1284 return; 1285 } 1286 hbh = mtod(ext, struct ip6_hbh *); 1287 hbhlen = (hbh->ip6h_len + 1) << 3; 1288 if (hbhlen != ext->m_len) { 1289 m_freem(ext); 1290 V_ip6stat.ip6s_tooshort++; 1291 return; 1292 } 1293#endif 1294 1295 /* 1296 * XXX: We copy the whole header even if a 1297 * jumbo payload option is included, the option which 1298 * is to be removed before returning according to 1299 * RFC2292. 1300 * Note: this constraint is removed in RFC3542 1301 */ 1302 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1303 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1304 IPPROTO_IPV6); 1305 if (*mp) 1306 mp = &(*mp)->m_next; 1307#ifdef PULLDOWN_TEST 1308 m_freem(ext); 1309#endif 1310 } 1311 } 1312 1313 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1314 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1315 1316 /* 1317 * Search for destination options headers or routing 1318 * header(s) through the header chain, and stores each 1319 * header as ancillary data. 1320 * Note that the order of the headers remains in 1321 * the chain of ancillary data. 1322 */ 1323 while (1) { /* is explicit loop prevention necessary? */ 1324 struct ip6_ext *ip6e = NULL; 1325 int elen; 1326#ifdef PULLDOWN_TEST 1327 struct mbuf *ext = NULL; 1328#endif 1329 1330 /* 1331 * if it is not an extension header, don't try to 1332 * pull it from the chain. 1333 */ 1334 switch (nxt) { 1335 case IPPROTO_DSTOPTS: 1336 case IPPROTO_ROUTING: 1337 case IPPROTO_HOPOPTS: 1338 case IPPROTO_AH: /* is it possible? */ 1339 break; 1340 default: 1341 goto loopend; 1342 } 1343 1344#ifndef PULLDOWN_TEST 1345 if (off + sizeof(*ip6e) > m->m_len) 1346 goto loopend; 1347 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1348 if (nxt == IPPROTO_AH) 1349 elen = (ip6e->ip6e_len + 2) << 2; 1350 else 1351 elen = (ip6e->ip6e_len + 1) << 3; 1352 if (off + elen > m->m_len) 1353 goto loopend; 1354#else 1355 ext = ip6_pullexthdr(m, off, nxt); 1356 if (ext == NULL) { 1357 V_ip6stat.ip6s_tooshort++; 1358 return; 1359 } 1360 ip6e = mtod(ext, struct ip6_ext *); 1361 if (nxt == IPPROTO_AH) 1362 elen = (ip6e->ip6e_len + 2) << 2; 1363 else 1364 elen = (ip6e->ip6e_len + 1) << 3; 1365 if (elen != ext->m_len) { 1366 m_freem(ext); 1367 V_ip6stat.ip6s_tooshort++; 1368 return; 1369 } 1370#endif 1371 1372 switch (nxt) { 1373 case IPPROTO_DSTOPTS: 1374 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1375 break; 1376 1377 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1378 IS2292(in6p, 1379 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1380 IPPROTO_IPV6); 1381 if (*mp) 1382 mp = &(*mp)->m_next; 1383 break; 1384 case IPPROTO_ROUTING: 1385 if (!in6p->inp_flags & IN6P_RTHDR) 1386 break; 1387 1388 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1389 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1390 IPPROTO_IPV6); 1391 if (*mp) 1392 mp = &(*mp)->m_next; 1393 break; 1394 case IPPROTO_HOPOPTS: 1395 case IPPROTO_AH: /* is it possible? */ 1396 break; 1397 1398 default: 1399 /* 1400 * other cases have been filtered in the above. 1401 * none will visit this case. here we supply 1402 * the code just in case (nxt overwritten or 1403 * other cases). 1404 */ 1405#ifdef PULLDOWN_TEST 1406 m_freem(ext); 1407#endif 1408 goto loopend; 1409 1410 } 1411 1412 /* proceed with the next header. */ 1413 off += elen; 1414 nxt = ip6e->ip6e_nxt; 1415 ip6e = NULL; 1416#ifdef PULLDOWN_TEST 1417 m_freem(ext); 1418 ext = NULL; 1419#endif 1420 } 1421 loopend: 1422 ; 1423 } 1424} 1425#undef IS2292 1426 1427void 1428ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1429{ 1430 struct socket *so; 1431 struct mbuf *m_mtu; 1432 struct ip6_mtuinfo mtuctl; 1433 1434 so = in6p->inp_socket; 1435 1436 if (mtu == NULL) 1437 return; 1438 1439#ifdef DIAGNOSTIC 1440 if (so == NULL) /* I believe this is impossible */ 1441 panic("ip6_notify_pmtu: socket is NULL"); 1442#endif 1443 1444 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1445 mtuctl.ip6m_mtu = *mtu; 1446 mtuctl.ip6m_addr = *dst; 1447 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1448 return; 1449 1450 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1451 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1452 return; 1453 1454 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1455 == 0) { 1456 m_freem(m_mtu); 1457 /* XXX: should count statistics */ 1458 } else 1459 sorwakeup(so); 1460 1461 return; 1462} 1463 1464#ifdef PULLDOWN_TEST 1465/* 1466 * pull single extension header from mbuf chain. returns single mbuf that 1467 * contains the result, or NULL on error. 1468 */ 1469static struct mbuf * 1470ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1471{ 1472 struct ip6_ext ip6e; 1473 size_t elen; 1474 struct mbuf *n; 1475 1476#ifdef DIAGNOSTIC 1477 switch (nxt) { 1478 case IPPROTO_DSTOPTS: 1479 case IPPROTO_ROUTING: 1480 case IPPROTO_HOPOPTS: 1481 case IPPROTO_AH: /* is it possible? */ 1482 break; 1483 default: 1484 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1485 } 1486#endif 1487 1488 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1489 if (nxt == IPPROTO_AH) 1490 elen = (ip6e.ip6e_len + 2) << 2; 1491 else 1492 elen = (ip6e.ip6e_len + 1) << 3; 1493 1494 MGET(n, M_DONTWAIT, MT_DATA); 1495 if (n && elen >= MLEN) { 1496 MCLGET(n, M_DONTWAIT); 1497 if ((n->m_flags & M_EXT) == 0) { 1498 m_free(n); 1499 n = NULL; 1500 } 1501 } 1502 if (!n) 1503 return NULL; 1504 1505 n->m_len = 0; 1506 if (elen >= M_TRAILINGSPACE(n)) { 1507 m_free(n); 1508 return NULL; 1509 } 1510 1511 m_copydata(m, off, elen, mtod(n, caddr_t)); 1512 n->m_len = elen; 1513 return n; 1514} 1515#endif 1516 1517/* 1518 * Get pointer to the previous header followed by the header 1519 * currently processed. 1520 * XXX: This function supposes that 1521 * M includes all headers, 1522 * the next header field and the header length field of each header 1523 * are valid, and 1524 * the sum of each header length equals to OFF. 1525 * Because of these assumptions, this function must be called very 1526 * carefully. Moreover, it will not be used in the near future when 1527 * we develop `neater' mechanism to process extension headers. 1528 */ 1529char * 1530ip6_get_prevhdr(struct mbuf *m, int off) 1531{ 1532 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1533 1534 if (off == sizeof(struct ip6_hdr)) 1535 return (&ip6->ip6_nxt); 1536 else { 1537 int len, nxt; 1538 struct ip6_ext *ip6e = NULL; 1539 1540 nxt = ip6->ip6_nxt; 1541 len = sizeof(struct ip6_hdr); 1542 while (len < off) { 1543 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1544 1545 switch (nxt) { 1546 case IPPROTO_FRAGMENT: 1547 len += sizeof(struct ip6_frag); 1548 break; 1549 case IPPROTO_AH: 1550 len += (ip6e->ip6e_len + 2) << 2; 1551 break; 1552 default: 1553 len += (ip6e->ip6e_len + 1) << 3; 1554 break; 1555 } 1556 nxt = ip6e->ip6e_nxt; 1557 } 1558 if (ip6e) 1559 return (&ip6e->ip6e_nxt); 1560 else 1561 return NULL; 1562 } 1563} 1564 1565/* 1566 * get next header offset. m will be retained. 1567 */ 1568int 1569ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1570{ 1571 struct ip6_hdr ip6; 1572 struct ip6_ext ip6e; 1573 struct ip6_frag fh; 1574 1575 /* just in case */ 1576 if (m == NULL) 1577 panic("ip6_nexthdr: m == NULL"); 1578 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1579 return -1; 1580 1581 switch (proto) { 1582 case IPPROTO_IPV6: 1583 if (m->m_pkthdr.len < off + sizeof(ip6)) 1584 return -1; 1585 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1586 if (nxtp) 1587 *nxtp = ip6.ip6_nxt; 1588 off += sizeof(ip6); 1589 return off; 1590 1591 case IPPROTO_FRAGMENT: 1592 /* 1593 * terminate parsing if it is not the first fragment, 1594 * it does not make sense to parse through it. 1595 */ 1596 if (m->m_pkthdr.len < off + sizeof(fh)) 1597 return -1; 1598 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1599 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1600 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1601 return -1; 1602 if (nxtp) 1603 *nxtp = fh.ip6f_nxt; 1604 off += sizeof(struct ip6_frag); 1605 return off; 1606 1607 case IPPROTO_AH: 1608 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1609 return -1; 1610 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1611 if (nxtp) 1612 *nxtp = ip6e.ip6e_nxt; 1613 off += (ip6e.ip6e_len + 2) << 2; 1614 return off; 1615 1616 case IPPROTO_HOPOPTS: 1617 case IPPROTO_ROUTING: 1618 case IPPROTO_DSTOPTS: 1619 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1620 return -1; 1621 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1622 if (nxtp) 1623 *nxtp = ip6e.ip6e_nxt; 1624 off += (ip6e.ip6e_len + 1) << 3; 1625 return off; 1626 1627 case IPPROTO_NONE: 1628 case IPPROTO_ESP: 1629 case IPPROTO_IPCOMP: 1630 /* give up */ 1631 return -1; 1632 1633 default: 1634 return -1; 1635 } 1636 1637 return -1; 1638} 1639 1640/* 1641 * get offset for the last header in the chain. m will be kept untainted. 1642 */ 1643int 1644ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1645{ 1646 int newoff; 1647 int nxt; 1648 1649 if (!nxtp) { 1650 nxt = -1; 1651 nxtp = &nxt; 1652 } 1653 while (1) { 1654 newoff = ip6_nexthdr(m, off, proto, nxtp); 1655 if (newoff < 0) 1656 return off; 1657 else if (newoff < off) 1658 return -1; /* invalid */ 1659 else if (newoff == off) 1660 return newoff; 1661 1662 off = newoff; 1663 proto = *nxtp; 1664 } 1665} 1666 1667struct ip6aux * 1668ip6_addaux(struct mbuf *m) 1669{ 1670 struct m_tag *mtag; 1671 1672 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1673 if (!mtag) { 1674 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1675 M_NOWAIT); 1676 if (mtag) { 1677 m_tag_prepend(m, mtag); 1678 bzero(mtag + 1, sizeof(struct ip6aux)); 1679 } 1680 } 1681 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1682} 1683 1684struct ip6aux * 1685ip6_findaux(struct mbuf *m) 1686{ 1687 struct m_tag *mtag; 1688 1689 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1690 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1691} 1692 1693void 1694ip6_delaux(struct mbuf *m) 1695{ 1696 struct m_tag *mtag; 1697 1698 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1699 if (mtag) 1700 m_tag_delete(m, mtag); 1701} 1702 1703/* 1704 * System control for IP6 1705 */ 1706 1707u_char inet6ctlerrmap[PRC_NCMDS] = { 1708 0, 0, 0, 0, 1709 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1710 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1711 EMSGSIZE, EHOSTUNREACH, 0, 0, 1712 0, 0, 0, 0, 1713 ENOPROTOOPT 1714}; 1715