1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1988, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 #include "opt_ipsec.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/proc.h> 75 #include <sys/domain.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/errno.h> 80 #include <sys/time.h> 81 #include <sys/kernel.h> 82 #include <sys/syslog.h> 83 84 #include <net/if.h> 85 #include <net/if_types.h> 86 #include <net/if_dl.h> 87 #include <net/route.h> 88 #include <net/netisr.h> 89 #include <net/pfil.h> 90 #include <net/vnet.h> 91 92 #include <netinet/in.h> 93 #include <netinet/in_systm.h> 94 #include <net/if_llatbl.h> 95 #ifdef INET 96 #include <netinet/ip.h> 97 #include <netinet/ip_icmp.h> 98 #endif /* INET */ 99 #include <netinet/ip6.h> 100 #include <netinet6/in6_var.h> 101 #include <netinet6/ip6_var.h> 102 #include <netinet/in_pcb.h> 103 #include <netinet/icmp6.h> 104 #include <netinet6/scope6_var.h> 105 #include <netinet6/in6_ifattach.h> 106 #include <netinet6/nd6.h> 107 108 #ifdef IPSEC 109 #include <netipsec/ipsec.h> 110 #include <netinet6/ip6_ipsec.h> 111 #include <netipsec/ipsec6.h> 112 #endif /* IPSEC */ 113 114 #include <netinet6/ip6protosw.h> 115 116 extern struct domain inet6domain; 117 118 u_char ip6_protox[IPPROTO_MAX]; 119 120 static 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 }; 126 127 VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead); 128 VNET_DEFINE(struct ip6stat, ip6stat); 129 130 VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch); 131 VNET_DECLARE(int, dad_init); 132 VNET_DECLARE(int, pmtu_expire); 133 VNET_DECLARE(int, pmtu_probe); 134 VNET_DECLARE(u_long, rip6_sendspace); 135 VNET_DECLARE(u_long, rip6_recvspace); 136 VNET_DECLARE(int, icmp6errppslim); 137 VNET_DECLARE(int, icmp6_nodeinfo); 138 VNET_DECLARE(int, udp6_sendspace); 139 VNET_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) 151 152 struct rwlock in6_ifaddr_lock; 153 RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock"); 154 155 VNET_DEFINE (struct pfil_head, inet6_pfil_hook); 156 157 static void ip6_init2(void *); 158 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 159 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 160 #ifdef PULLDOWN_TEST 161 static 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 */ 168 void 169 ip6_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; /* enabled 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; 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 /* Initialize packet filter hooks. */ 251 V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 252 V_inet6_pfil_hook.ph_af = AF_INET6; 253 if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0) 254 printf("%s: WARNING: unable to register pfil hook, " 255 "error %d\n", __func__, i); 256 257 /* Skip global initialization stuff for non-default instances. */ 258 if (!IS_DEFAULT_VNET(curvnet)) 259 return; 260 261 #ifdef DIAGNOSTIC 262 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 263 panic("sizeof(protosw) != sizeof(ip6protosw)"); 264 #endif 265 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 266 if (pr == NULL) 267 panic("ip6_init"); 268 269 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ 270 for (i = 0; i < IPPROTO_MAX; i++) 271 ip6_protox[i] = pr - inet6sw; 272 /* 273 * Cycle through IP protocols and put them into the appropriate place 274 * in ip6_protox[]. 275 */ 276 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 277 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 278 if (pr->pr_domain->dom_family == PF_INET6 && 279 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 280 /* Be careful to only index valid IP protocols. */ 281 if (pr->pr_protocol < IPPROTO_MAX) 282 ip6_protox[pr->pr_protocol] = pr - inet6sw; 283 } 284 285 netisr_register(&ip6_nh); 286 } 287 288 #ifdef VIMAGE 289 void 290 ip6_destroy() 291 { 292 293 nd6_destroy(); 294 callout_drain(&V_in6_tmpaddrtimer_ch); 295 } 296 #endif 297 298 static int 299 ip6_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 } 315 316 static void 317 ip6_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 */ 325 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 326 327 void 328 ip6_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(&V_inet6_pfil_hook)) 519 goto passin; 520 521 if (pfil_run_hooks(&V_inet6_pfil_hook, &m, 522 m->m_pkthdr.rcvif, PFIL_IN, NULL)) 523 return; 524 if (m == NULL) /* consumed by filter */ 525 return; 526 ip6 = mtod(m, struct ip6_hdr *); 527 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 528 529 passin: 530 /* 531 * Disambiguate address scope zones (if there is ambiguity). 532 * We first make sure that the original source or destination address 533 * is not in our internal form for scoped addresses. Such addresses 534 * are not necessarily invalid spec-wise, but we cannot accept them due 535 * to the usage conflict. 536 * in6_setscope() then also checks and rejects the cases where src or 537 * dst are the loopback address and the receiving interface 538 * is not loopback. 539 */ 540 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 541 V_ip6stat.ip6s_badscope++; /* XXX */ 542 goto bad; 543 } 544 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 545 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 546 V_ip6stat.ip6s_badscope++; 547 goto bad; 548 } 549 550 /* 551 * Multicast check. Assume packet is for us to avoid 552 * prematurely taking locks. 553 */ 554 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 555 ours = 1; 556 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 557 deliverifp = m->m_pkthdr.rcvif; 558 goto hbhcheck; 559 } 560 561 /* 562 * Unicast check 563 */ 564 565 bzero(&dst6, sizeof(dst6)); 566 dst6.sin6_family = AF_INET6; 567 dst6.sin6_len = sizeof(struct sockaddr_in6); 568 dst6.sin6_addr = ip6->ip6_dst; 569 ifp = m->m_pkthdr.rcvif; 570 IF_AFDATA_LOCK(ifp); 571 lle = lla_lookup(LLTABLE6(ifp), 0, 572 (struct sockaddr *)&dst6); 573 IF_AFDATA_UNLOCK(ifp); 574 if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) { 575 ours = 1; 576 deliverifp = ifp; 577 LLE_RUNLOCK(lle); 578 goto hbhcheck; 579 } 580 if (lle != NULL) 581 LLE_RUNLOCK(lle); 582 583 dst = &rin6.ro_dst; 584 dst->sin6_len = sizeof(struct sockaddr_in6); 585 dst->sin6_family = AF_INET6; 586 dst->sin6_addr = ip6->ip6_dst; 587 rin6.ro_rt = rtalloc1((struct sockaddr *)dst, 0, 0); 588 if (rin6.ro_rt) 589 RT_UNLOCK(rin6.ro_rt); 590 591 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 592 593 /* 594 * Accept the packet if the forwarding interface to the destination 595 * according to the routing table is the loopback interface, 596 * unless the associated route has a gateway. 597 * Note that this approach causes to accept a packet if there is a 598 * route to the loopback interface for the destination of the packet. 599 * But we think it's even useful in some situations, e.g. when using 600 * a special daemon which wants to intercept the packet. 601 * 602 * XXX: some OSes automatically make a cloned route for the destination 603 * of an outgoing packet. If the outgoing interface of the packet 604 * is a loopback one, the kernel would consider the packet to be 605 * accepted, even if we have no such address assinged on the interface. 606 * We check the cloned flag of the route entry to reject such cases, 607 * assuming that route entries for our own addresses are not made by 608 * cloning (it should be true because in6_addloop explicitly installs 609 * the host route). However, we might have to do an explicit check 610 * while it would be less efficient. Or, should we rather install a 611 * reject route for such a case? 612 */ 613 if (rin6.ro_rt && 614 (rin6.ro_rt->rt_flags & 615 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 616 #ifdef RTF_WASCLONED 617 !(rin6.ro_rt->rt_flags & RTF_WASCLONED) && 618 #endif 619 #ifdef RTF_CLONED 620 !(rin6.ro_rt->rt_flags & RTF_CLONED) && 621 #endif 622 #if 0 623 /* 624 * The check below is redundant since the comparison of 625 * the destination and the key of the rtentry has 626 * already done through looking up the routing table. 627 */ 628 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 629 &rt6_key(rin6.ro_rt)->sin6_addr) 630 #endif 631 rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) { 632 int free_ia6 = 0; 633 struct in6_ifaddr *ia6; 634 635 /* 636 * found the loopback route to the interface address 637 */ 638 if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) { 639 struct sockaddr_in6 dest6; 640 641 bzero(&dest6, sizeof(dest6)); 642 dest6.sin6_family = AF_INET6; 643 dest6.sin6_len = sizeof(dest6); 644 dest6.sin6_addr = ip6->ip6_dst; 645 ia6 = (struct in6_ifaddr *) 646 ifa_ifwithaddr((struct sockaddr *)&dest6); 647 if (ia6 == NULL) 648 goto bad; 649 free_ia6 = 1; 650 } 651 else 652 ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa; 653 654 /* 655 * record address information into m_tag. 656 */ 657 (void)ip6_setdstifaddr(m, ia6); 658 659 /* 660 * packets to a tentative, duplicated, or somehow invalid 661 * address must not be accepted. 662 */ 663 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 664 /* this address is ready */ 665 ours = 1; 666 deliverifp = ia6->ia_ifp; /* correct? */ 667 /* Count the packet in the ip address stats */ 668 ia6->ia_ifa.if_ipackets++; 669 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 670 if (ia6 != NULL && free_ia6 != 0) 671 ifa_free(&ia6->ia_ifa); 672 goto hbhcheck; 673 } else { 674 char ip6bufs[INET6_ADDRSTRLEN]; 675 char ip6bufd[INET6_ADDRSTRLEN]; 676 /* address is not ready, so discard the packet. */ 677 nd6log((LOG_INFO, 678 "ip6_input: packet to an unready address %s->%s\n", 679 ip6_sprintf(ip6bufs, &ip6->ip6_src), 680 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 681 682 if (ia6 != NULL && free_ia6 != 0) 683 ifa_free(&ia6->ia_ifa); 684 goto bad; 685 } 686 } 687 688 /* 689 * FAITH (Firewall Aided Internet Translator) 690 */ 691 if (V_ip6_keepfaith) { 692 if (rin6.ro_rt && rin6.ro_rt->rt_ifp && 693 rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) { 694 /* XXX do we need more sanity checks? */ 695 ours = 1; 696 deliverifp = rin6.ro_rt->rt_ifp; /* faith */ 697 goto hbhcheck; 698 } 699 } 700 701 /* 702 * Now there is no reason to process the packet if it's not our own 703 * and we're not a router. 704 */ 705 if (!V_ip6_forwarding) { 706 V_ip6stat.ip6s_cantforward++; 707 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 708 goto bad; 709 } 710 711 hbhcheck: 712 /* 713 * record address information into m_tag, if we don't have one yet. 714 * note that we are unable to record it, if the address is not listed 715 * as our interface address (e.g. multicast addresses, addresses 716 * within FAITH prefixes and such). 717 */ 718 if (deliverifp && !ip6_getdstifaddr(m)) { 719 struct in6_ifaddr *ia6; 720 721 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 722 if (ia6) { 723 if (!ip6_setdstifaddr(m, ia6)) { 724 /* 725 * XXX maybe we should drop the packet here, 726 * as we could not provide enough information 727 * to the upper layers. 728 */ 729 } 730 ifa_free(&ia6->ia_ifa); 731 } 732 } 733 734 /* 735 * Process Hop-by-Hop options header if it's contained. 736 * m may be modified in ip6_hopopts_input(). 737 * If a JumboPayload option is included, plen will also be modified. 738 */ 739 plen = (u_int32_t)ntohs(ip6->ip6_plen); 740 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 741 struct ip6_hbh *hbh; 742 743 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 744 #if 0 /*touches NULL pointer*/ 745 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 746 #endif 747 goto out; /* m have already been freed */ 748 } 749 750 /* adjust pointer */ 751 ip6 = mtod(m, struct ip6_hdr *); 752 753 /* 754 * if the payload length field is 0 and the next header field 755 * indicates Hop-by-Hop Options header, then a Jumbo Payload 756 * option MUST be included. 757 */ 758 if (ip6->ip6_plen == 0 && plen == 0) { 759 /* 760 * Note that if a valid jumbo payload option is 761 * contained, ip6_hopopts_input() must set a valid 762 * (non-zero) payload length to the variable plen. 763 */ 764 V_ip6stat.ip6s_badoptions++; 765 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 766 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 767 icmp6_error(m, ICMP6_PARAM_PROB, 768 ICMP6_PARAMPROB_HEADER, 769 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 770 goto out; 771 } 772 #ifndef PULLDOWN_TEST 773 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 774 hbh = (struct ip6_hbh *)(ip6 + 1); 775 #else 776 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 777 sizeof(struct ip6_hbh)); 778 if (hbh == NULL) { 779 V_ip6stat.ip6s_tooshort++; 780 goto out; 781 } 782 #endif 783 nxt = hbh->ip6h_nxt; 784 785 /* 786 * If we are acting as a router and the packet contains a 787 * router alert option, see if we know the option value. 788 * Currently, we only support the option value for MLD, in which 789 * case we should pass the packet to the multicast routing 790 * daemon. 791 */ 792 if (rtalert != ~0) { 793 switch (rtalert) { 794 case IP6OPT_RTALERT_MLD: 795 if (V_ip6_forwarding) 796 ours = 1; 797 break; 798 default: 799 /* 800 * RFC2711 requires unrecognized values must be 801 * silently ignored. 802 */ 803 break; 804 } 805 } 806 } else 807 nxt = ip6->ip6_nxt; 808 809 /* 810 * Check that the amount of data in the buffers 811 * is as at least much as the IPv6 header would have us expect. 812 * Trim mbufs if longer than we expect. 813 * Drop packet if shorter than we expect. 814 */ 815 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 816 V_ip6stat.ip6s_tooshort++; 817 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 818 goto bad; 819 } 820 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 821 if (m->m_len == m->m_pkthdr.len) { 822 m->m_len = sizeof(struct ip6_hdr) + plen; 823 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 824 } else 825 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 826 } 827 828 /* 829 * Forward if desirable. 830 */ 831 if (V_ip6_mrouter && 832 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 833 /* 834 * If we are acting as a multicast router, all 835 * incoming multicast packets are passed to the 836 * kernel-level multicast forwarding function. 837 * The packet is returned (relatively) intact; if 838 * ip6_mforward() returns a non-zero value, the packet 839 * must be discarded, else it may be accepted below. 840 * 841 * XXX TODO: Check hlim and multicast scope here to avoid 842 * unnecessarily calling into ip6_mforward(). 843 */ 844 if (ip6_mforward && 845 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 846 IP6STAT_INC(ip6s_cantforward); 847 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 848 goto bad; 849 } 850 } else if (!ours) { 851 ip6_forward(m, srcrt); 852 goto out; 853 } 854 855 ip6 = mtod(m, struct ip6_hdr *); 856 857 /* 858 * Malicious party may be able to use IPv4 mapped addr to confuse 859 * tcp/udp stack and bypass security checks (act as if it was from 860 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 861 * 862 * For SIIT end node behavior, you may want to disable the check. 863 * However, you will become vulnerable to attacks using IPv4 mapped 864 * source. 865 */ 866 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 867 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 868 V_ip6stat.ip6s_badscope++; 869 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 870 goto bad; 871 } 872 873 /* 874 * Tell launch routine the next header 875 */ 876 V_ip6stat.ip6s_delivered++; 877 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 878 nest = 0; 879 880 while (nxt != IPPROTO_DONE) { 881 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 882 V_ip6stat.ip6s_toomanyhdr++; 883 goto bad; 884 } 885 886 /* 887 * protection against faulty packet - there should be 888 * more sanity checks in header chain processing. 889 */ 890 if (m->m_pkthdr.len < off) { 891 V_ip6stat.ip6s_tooshort++; 892 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 893 goto bad; 894 } 895 896 #ifdef IPSEC 897 /* 898 * enforce IPsec policy checking if we are seeing last header. 899 * note that we do not visit this with protocols with pcb layer 900 * code - like udp/tcp/raw ip. 901 */ 902 if (ip6_ipsec_input(m, nxt)) 903 goto bad; 904 #endif /* IPSEC */ 905 906 /* 907 * Use mbuf flags to propagate Router Alert option to 908 * ICMPv6 layer, as hop-by-hop options have been stripped. 909 */ 910 if (nxt == IPPROTO_ICMPV6 && rtalert != ~0) 911 m->m_flags |= M_RTALERT_MLD; 912 913 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 914 } 915 goto out; 916 bad: 917 m_freem(m); 918 out: 919 if (rin6.ro_rt) 920 RTFREE(rin6.ro_rt); 921 } 922 923 /* 924 * set/grab in6_ifaddr correspond to IPv6 destination address. 925 * XXX backward compatibility wrapper 926 * 927 * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag, 928 * and then bump it when the tag is copied, and release it when the tag is 929 * freed. Unfortunately, m_tags don't support deep copies (yet), so instead 930 * we just bump the ia refcount when we receive it. This should be fixed. 931 */ 932 static struct ip6aux * 933 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 934 { 935 struct ip6aux *ip6a; 936 937 ip6a = ip6_addaux(m); 938 if (ip6a) 939 ip6a->ip6a_dstia6 = ia6; 940 return ip6a; /* NULL if failed to set */ 941 } 942 943 struct in6_ifaddr * 944 ip6_getdstifaddr(struct mbuf *m) 945 { 946 struct ip6aux *ip6a; 947 struct in6_ifaddr *ia; 948 949 ip6a = ip6_findaux(m); 950 if (ip6a) { 951 ia = ip6a->ip6a_dstia6; 952 ifa_ref(&ia->ia_ifa); 953 return ia; 954 } else 955 return NULL; 956 } 957 958 /* 959 * Hop-by-Hop options header processing. If a valid jumbo payload option is 960 * included, the real payload length will be stored in plenp. 961 * 962 * rtalertp - XXX: should be stored more smart way 963 */ 964 static int 965 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 966 struct mbuf **mp, int *offp) 967 { 968 struct mbuf *m = *mp; 969 int off = *offp, hbhlen; 970 struct ip6_hbh *hbh; 971 u_int8_t *opt; 972 973 /* validation of the length of the header */ 974 #ifndef PULLDOWN_TEST 975 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 976 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 977 hbhlen = (hbh->ip6h_len + 1) << 3; 978 979 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 980 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 981 #else 982 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 983 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 984 if (hbh == NULL) { 985 V_ip6stat.ip6s_tooshort++; 986 return -1; 987 } 988 hbhlen = (hbh->ip6h_len + 1) << 3; 989 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 990 hbhlen); 991 if (hbh == NULL) { 992 V_ip6stat.ip6s_tooshort++; 993 return -1; 994 } 995 #endif 996 off += hbhlen; 997 hbhlen -= sizeof(struct ip6_hbh); 998 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 999 1000 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 1001 hbhlen, rtalertp, plenp) < 0) 1002 return (-1); 1003 1004 *offp = off; 1005 *mp = m; 1006 return (0); 1007 } 1008 1009 /* 1010 * Search header for all Hop-by-hop options and process each option. 1011 * This function is separate from ip6_hopopts_input() in order to 1012 * handle a case where the sending node itself process its hop-by-hop 1013 * options header. In such a case, the function is called from ip6_output(). 1014 * 1015 * The function assumes that hbh header is located right after the IPv6 header 1016 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 1017 * opthead + hbhlen is located in continuous memory region. 1018 */ 1019 int 1020 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 1021 u_int32_t *rtalertp, u_int32_t *plenp) 1022 { 1023 struct ip6_hdr *ip6; 1024 int optlen = 0; 1025 u_int8_t *opt = opthead; 1026 u_int16_t rtalert_val; 1027 u_int32_t jumboplen; 1028 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 1029 1030 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 1031 switch (*opt) { 1032 case IP6OPT_PAD1: 1033 optlen = 1; 1034 break; 1035 case IP6OPT_PADN: 1036 if (hbhlen < IP6OPT_MINLEN) { 1037 V_ip6stat.ip6s_toosmall++; 1038 goto bad; 1039 } 1040 optlen = *(opt + 1) + 2; 1041 break; 1042 case IP6OPT_ROUTER_ALERT: 1043 /* XXX may need check for alignment */ 1044 if (hbhlen < IP6OPT_RTALERT_LEN) { 1045 V_ip6stat.ip6s_toosmall++; 1046 goto bad; 1047 } 1048 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 1049 /* XXX stat */ 1050 icmp6_error(m, ICMP6_PARAM_PROB, 1051 ICMP6_PARAMPROB_HEADER, 1052 erroff + opt + 1 - opthead); 1053 return (-1); 1054 } 1055 optlen = IP6OPT_RTALERT_LEN; 1056 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 1057 *rtalertp = ntohs(rtalert_val); 1058 break; 1059 case IP6OPT_JUMBO: 1060 /* XXX may need check for alignment */ 1061 if (hbhlen < IP6OPT_JUMBO_LEN) { 1062 V_ip6stat.ip6s_toosmall++; 1063 goto bad; 1064 } 1065 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1066 /* XXX stat */ 1067 icmp6_error(m, ICMP6_PARAM_PROB, 1068 ICMP6_PARAMPROB_HEADER, 1069 erroff + opt + 1 - opthead); 1070 return (-1); 1071 } 1072 optlen = IP6OPT_JUMBO_LEN; 1073 1074 /* 1075 * IPv6 packets that have non 0 payload length 1076 * must not contain a jumbo payload option. 1077 */ 1078 ip6 = mtod(m, struct ip6_hdr *); 1079 if (ip6->ip6_plen) { 1080 V_ip6stat.ip6s_badoptions++; 1081 icmp6_error(m, ICMP6_PARAM_PROB, 1082 ICMP6_PARAMPROB_HEADER, 1083 erroff + opt - opthead); 1084 return (-1); 1085 } 1086 1087 /* 1088 * We may see jumbolen in unaligned location, so 1089 * we'd need to perform bcopy(). 1090 */ 1091 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1092 jumboplen = (u_int32_t)htonl(jumboplen); 1093 1094 #if 1 1095 /* 1096 * if there are multiple jumbo payload options, 1097 * *plenp will be non-zero and the packet will be 1098 * rejected. 1099 * the behavior may need some debate in ipngwg - 1100 * multiple options does not make sense, however, 1101 * there's no explicit mention in specification. 1102 */ 1103 if (*plenp != 0) { 1104 V_ip6stat.ip6s_badoptions++; 1105 icmp6_error(m, ICMP6_PARAM_PROB, 1106 ICMP6_PARAMPROB_HEADER, 1107 erroff + opt + 2 - opthead); 1108 return (-1); 1109 } 1110 #endif 1111 1112 /* 1113 * jumbo payload length must be larger than 65535. 1114 */ 1115 if (jumboplen <= IPV6_MAXPACKET) { 1116 V_ip6stat.ip6s_badoptions++; 1117 icmp6_error(m, ICMP6_PARAM_PROB, 1118 ICMP6_PARAMPROB_HEADER, 1119 erroff + opt + 2 - opthead); 1120 return (-1); 1121 } 1122 *plenp = jumboplen; 1123 1124 break; 1125 default: /* unknown option */ 1126 if (hbhlen < IP6OPT_MINLEN) { 1127 V_ip6stat.ip6s_toosmall++; 1128 goto bad; 1129 } 1130 optlen = ip6_unknown_opt(opt, m, 1131 erroff + opt - opthead); 1132 if (optlen == -1) 1133 return (-1); 1134 optlen += 2; 1135 break; 1136 } 1137 } 1138 1139 return (0); 1140 1141 bad: 1142 m_freem(m); 1143 return (-1); 1144 } 1145 1146 /* 1147 * Unknown option processing. 1148 * The third argument `off' is the offset from the IPv6 header to the option, 1149 * which is necessary if the IPv6 header the and option header and IPv6 header 1150 * is not continuous in order to return an ICMPv6 error. 1151 */ 1152 int 1153 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1154 { 1155 struct ip6_hdr *ip6; 1156 1157 switch (IP6OPT_TYPE(*optp)) { 1158 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1159 return ((int)*(optp + 1)); 1160 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1161 m_freem(m); 1162 return (-1); 1163 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1164 V_ip6stat.ip6s_badoptions++; 1165 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1166 return (-1); 1167 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1168 V_ip6stat.ip6s_badoptions++; 1169 ip6 = mtod(m, struct ip6_hdr *); 1170 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1171 (m->m_flags & (M_BCAST|M_MCAST))) 1172 m_freem(m); 1173 else 1174 icmp6_error(m, ICMP6_PARAM_PROB, 1175 ICMP6_PARAMPROB_OPTION, off); 1176 return (-1); 1177 } 1178 1179 m_freem(m); /* XXX: NOTREACHED */ 1180 return (-1); 1181 } 1182 1183 /* 1184 * Create the "control" list for this pcb. 1185 * These functions will not modify mbuf chain at all. 1186 * 1187 * With KAME mbuf chain restriction: 1188 * The routine will be called from upper layer handlers like tcp6_input(). 1189 * Thus the routine assumes that the caller (tcp6_input) have already 1190 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1191 * very first mbuf on the mbuf chain. 1192 * 1193 * ip6_savecontrol_v4 will handle those options that are possible to be 1194 * set on a v4-mapped socket. 1195 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1196 * options and handle the v6-only ones itself. 1197 */ 1198 struct mbuf ** 1199 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1200 int *v4only) 1201 { 1202 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1203 1204 #ifdef SO_TIMESTAMP 1205 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1206 struct timeval tv; 1207 1208 microtime(&tv); 1209 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1210 SCM_TIMESTAMP, SOL_SOCKET); 1211 if (*mp) 1212 mp = &(*mp)->m_next; 1213 } 1214 #endif 1215 1216 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1217 if (v4only != NULL) 1218 *v4only = 1; 1219 return (mp); 1220 } 1221 1222 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1223 /* RFC 2292 sec. 5 */ 1224 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1225 struct in6_pktinfo pi6; 1226 1227 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1228 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1229 pi6.ipi6_ifindex = 1230 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1231 1232 *mp = sbcreatecontrol((caddr_t) &pi6, 1233 sizeof(struct in6_pktinfo), 1234 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1235 if (*mp) 1236 mp = &(*mp)->m_next; 1237 } 1238 1239 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1240 int hlim = ip6->ip6_hlim & 0xff; 1241 1242 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1243 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1244 IPPROTO_IPV6); 1245 if (*mp) 1246 mp = &(*mp)->m_next; 1247 } 1248 1249 if (v4only != NULL) 1250 *v4only = 0; 1251 return (mp); 1252 } 1253 1254 void 1255 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1256 { 1257 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1258 int v4only = 0; 1259 1260 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1261 if (v4only) 1262 return; 1263 1264 if ((in6p->inp_flags & IN6P_TCLASS) != 0) { 1265 u_int32_t flowinfo; 1266 int tclass; 1267 1268 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1269 flowinfo >>= 20; 1270 1271 tclass = flowinfo & 0xff; 1272 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1273 IPV6_TCLASS, IPPROTO_IPV6); 1274 if (*mp) 1275 mp = &(*mp)->m_next; 1276 } 1277 1278 /* 1279 * IPV6_HOPOPTS socket option. Recall that we required super-user 1280 * privilege for the option (see ip6_ctloutput), but it might be too 1281 * strict, since there might be some hop-by-hop options which can be 1282 * returned to normal user. 1283 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1284 */ 1285 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1286 /* 1287 * Check if a hop-by-hop options header is contatined in the 1288 * received packet, and if so, store the options as ancillary 1289 * data. Note that a hop-by-hop options header must be 1290 * just after the IPv6 header, which is assured through the 1291 * IPv6 input processing. 1292 */ 1293 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1294 struct ip6_hbh *hbh; 1295 int hbhlen = 0; 1296 #ifdef PULLDOWN_TEST 1297 struct mbuf *ext; 1298 #endif 1299 1300 #ifndef PULLDOWN_TEST 1301 hbh = (struct ip6_hbh *)(ip6 + 1); 1302 hbhlen = (hbh->ip6h_len + 1) << 3; 1303 #else 1304 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1305 ip6->ip6_nxt); 1306 if (ext == NULL) { 1307 V_ip6stat.ip6s_tooshort++; 1308 return; 1309 } 1310 hbh = mtod(ext, struct ip6_hbh *); 1311 hbhlen = (hbh->ip6h_len + 1) << 3; 1312 if (hbhlen != ext->m_len) { 1313 m_freem(ext); 1314 V_ip6stat.ip6s_tooshort++; 1315 return; 1316 } 1317 #endif 1318 1319 /* 1320 * XXX: We copy the whole header even if a 1321 * jumbo payload option is included, the option which 1322 * is to be removed before returning according to 1323 * RFC2292. 1324 * Note: this constraint is removed in RFC3542 1325 */ 1326 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1327 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1328 IPPROTO_IPV6); 1329 if (*mp) 1330 mp = &(*mp)->m_next; 1331 #ifdef PULLDOWN_TEST 1332 m_freem(ext); 1333 #endif 1334 } 1335 } 1336 1337 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1338 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1339 1340 /* 1341 * Search for destination options headers or routing 1342 * header(s) through the header chain, and stores each 1343 * header as ancillary data. 1344 * Note that the order of the headers remains in 1345 * the chain of ancillary data. 1346 */ 1347 while (1) { /* is explicit loop prevention necessary? */ 1348 struct ip6_ext *ip6e = NULL; 1349 int elen; 1350 #ifdef PULLDOWN_TEST 1351 struct mbuf *ext = NULL; 1352 #endif 1353 1354 /* 1355 * if it is not an extension header, don't try to 1356 * pull it from the chain. 1357 */ 1358 switch (nxt) { 1359 case IPPROTO_DSTOPTS: 1360 case IPPROTO_ROUTING: 1361 case IPPROTO_HOPOPTS: 1362 case IPPROTO_AH: /* is it possible? */ 1363 break; 1364 default: 1365 goto loopend; 1366 } 1367 1368 #ifndef PULLDOWN_TEST 1369 if (off + sizeof(*ip6e) > m->m_len) 1370 goto loopend; 1371 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1372 if (nxt == IPPROTO_AH) 1373 elen = (ip6e->ip6e_len + 2) << 2; 1374 else 1375 elen = (ip6e->ip6e_len + 1) << 3; 1376 if (off + elen > m->m_len) 1377 goto loopend; 1378 #else 1379 ext = ip6_pullexthdr(m, off, nxt); 1380 if (ext == NULL) { 1381 V_ip6stat.ip6s_tooshort++; 1382 return; 1383 } 1384 ip6e = mtod(ext, struct ip6_ext *); 1385 if (nxt == IPPROTO_AH) 1386 elen = (ip6e->ip6e_len + 2) << 2; 1387 else 1388 elen = (ip6e->ip6e_len + 1) << 3; 1389 if (elen != ext->m_len) { 1390 m_freem(ext); 1391 V_ip6stat.ip6s_tooshort++; 1392 return; 1393 } 1394 #endif 1395 1396 switch (nxt) { 1397 case IPPROTO_DSTOPTS: 1398 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1399 break; 1400 1401 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1402 IS2292(in6p, 1403 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1404 IPPROTO_IPV6); 1405 if (*mp) 1406 mp = &(*mp)->m_next; 1407 break; 1408 case IPPROTO_ROUTING: 1409 if (!(in6p->inp_flags & IN6P_RTHDR)) 1410 break; 1411 1412 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1413 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1414 IPPROTO_IPV6); 1415 if (*mp) 1416 mp = &(*mp)->m_next; 1417 break; 1418 case IPPROTO_HOPOPTS: 1419 case IPPROTO_AH: /* is it possible? */ 1420 break; 1421 1422 default: 1423 /* 1424 * other cases have been filtered in the above. 1425 * none will visit this case. here we supply 1426 * the code just in case (nxt overwritten or 1427 * other cases). 1428 */ 1429 #ifdef PULLDOWN_TEST 1430 m_freem(ext); 1431 #endif 1432 goto loopend; 1433 1434 } 1435 1436 /* proceed with the next header. */ 1437 off += elen; 1438 nxt = ip6e->ip6e_nxt; 1439 ip6e = NULL; 1440 #ifdef PULLDOWN_TEST 1441 m_freem(ext); 1442 ext = NULL; 1443 #endif 1444 } 1445 loopend: 1446 ; 1447 } 1448 } 1449 #undef IS2292 1450 1451 void 1452 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1453 { 1454 struct socket *so; 1455 struct mbuf *m_mtu; 1456 struct ip6_mtuinfo mtuctl; 1457 1458 so = in6p->inp_socket; 1459 1460 if (mtu == NULL) 1461 return; 1462 1463 #ifdef DIAGNOSTIC 1464 if (so == NULL) /* I believe this is impossible */ 1465 panic("ip6_notify_pmtu: socket is NULL"); 1466 #endif 1467 1468 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1469 mtuctl.ip6m_mtu = *mtu; 1470 mtuctl.ip6m_addr = *dst; 1471 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1472 return; 1473 1474 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1475 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1476 return; 1477 1478 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1479 == 0) { 1480 m_freem(m_mtu); 1481 /* XXX: should count statistics */ 1482 } else 1483 sorwakeup(so); 1484 1485 return; 1486 } 1487 1488 #ifdef PULLDOWN_TEST 1489 /* 1490 * pull single extension header from mbuf chain. returns single mbuf that 1491 * contains the result, or NULL on error. 1492 */ 1493 static struct mbuf * 1494 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1495 { 1496 struct ip6_ext ip6e; 1497 size_t elen; 1498 struct mbuf *n; 1499 1500 #ifdef DIAGNOSTIC 1501 switch (nxt) { 1502 case IPPROTO_DSTOPTS: 1503 case IPPROTO_ROUTING: 1504 case IPPROTO_HOPOPTS: 1505 case IPPROTO_AH: /* is it possible? */ 1506 break; 1507 default: 1508 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1509 } 1510 #endif 1511 1512 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1513 if (nxt == IPPROTO_AH) 1514 elen = (ip6e.ip6e_len + 2) << 2; 1515 else 1516 elen = (ip6e.ip6e_len + 1) << 3; 1517 1518 MGET(n, M_DONTWAIT, MT_DATA); 1519 if (n && elen >= MLEN) { 1520 MCLGET(n, M_DONTWAIT); 1521 if ((n->m_flags & M_EXT) == 0) { 1522 m_free(n); 1523 n = NULL; 1524 } 1525 } 1526 if (!n) 1527 return NULL; 1528 1529 n->m_len = 0; 1530 if (elen >= M_TRAILINGSPACE(n)) { 1531 m_free(n); 1532 return NULL; 1533 } 1534 1535 m_copydata(m, off, elen, mtod(n, caddr_t)); 1536 n->m_len = elen; 1537 return n; 1538 } 1539 #endif 1540 1541 /* 1542 * Get pointer to the previous header followed by the header 1543 * currently processed. 1544 * XXX: This function supposes that 1545 * M includes all headers, 1546 * the next header field and the header length field of each header 1547 * are valid, and 1548 * the sum of each header length equals to OFF. 1549 * Because of these assumptions, this function must be called very 1550 * carefully. Moreover, it will not be used in the near future when 1551 * we develop `neater' mechanism to process extension headers. 1552 */ 1553 char * 1554 ip6_get_prevhdr(struct mbuf *m, int off) 1555 { 1556 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1557 1558 if (off == sizeof(struct ip6_hdr)) 1559 return (&ip6->ip6_nxt); 1560 else { 1561 int len, nxt; 1562 struct ip6_ext *ip6e = NULL; 1563 1564 nxt = ip6->ip6_nxt; 1565 len = sizeof(struct ip6_hdr); 1566 while (len < off) { 1567 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1568 1569 switch (nxt) { 1570 case IPPROTO_FRAGMENT: 1571 len += sizeof(struct ip6_frag); 1572 break; 1573 case IPPROTO_AH: 1574 len += (ip6e->ip6e_len + 2) << 2; 1575 break; 1576 default: 1577 len += (ip6e->ip6e_len + 1) << 3; 1578 break; 1579 } 1580 nxt = ip6e->ip6e_nxt; 1581 } 1582 if (ip6e) 1583 return (&ip6e->ip6e_nxt); 1584 else 1585 return NULL; 1586 } 1587 } 1588 1589 /* 1590 * get next header offset. m will be retained. 1591 */ 1592 int 1593 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1594 { 1595 struct ip6_hdr ip6; 1596 struct ip6_ext ip6e; 1597 struct ip6_frag fh; 1598 1599 /* just in case */ 1600 if (m == NULL) 1601 panic("ip6_nexthdr: m == NULL"); 1602 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1603 return -1; 1604 1605 switch (proto) { 1606 case IPPROTO_IPV6: 1607 if (m->m_pkthdr.len < off + sizeof(ip6)) 1608 return -1; 1609 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1610 if (nxtp) 1611 *nxtp = ip6.ip6_nxt; 1612 off += sizeof(ip6); 1613 return off; 1614 1615 case IPPROTO_FRAGMENT: 1616 /* 1617 * terminate parsing if it is not the first fragment, 1618 * it does not make sense to parse through it. 1619 */ 1620 if (m->m_pkthdr.len < off + sizeof(fh)) 1621 return -1; 1622 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1623 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1624 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1625 return -1; 1626 if (nxtp) 1627 *nxtp = fh.ip6f_nxt; 1628 off += sizeof(struct ip6_frag); 1629 return off; 1630 1631 case IPPROTO_AH: 1632 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1633 return -1; 1634 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1635 if (nxtp) 1636 *nxtp = ip6e.ip6e_nxt; 1637 off += (ip6e.ip6e_len + 2) << 2; 1638 return off; 1639 1640 case IPPROTO_HOPOPTS: 1641 case IPPROTO_ROUTING: 1642 case IPPROTO_DSTOPTS: 1643 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1644 return -1; 1645 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1646 if (nxtp) 1647 *nxtp = ip6e.ip6e_nxt; 1648 off += (ip6e.ip6e_len + 1) << 3; 1649 return off; 1650 1651 case IPPROTO_NONE: 1652 case IPPROTO_ESP: 1653 case IPPROTO_IPCOMP: 1654 /* give up */ 1655 return -1; 1656 1657 default: 1658 return -1; 1659 } 1660 1661 return -1; 1662 } 1663 1664 /* 1665 * get offset for the last header in the chain. m will be kept untainted. 1666 */ 1667 int 1668 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1669 { 1670 int newoff; 1671 int nxt; 1672 1673 if (!nxtp) { 1674 nxt = -1; 1675 nxtp = &nxt; 1676 } 1677 while (1) { 1678 newoff = ip6_nexthdr(m, off, proto, nxtp); 1679 if (newoff < 0) 1680 return off; 1681 else if (newoff < off) 1682 return -1; /* invalid */ 1683 else if (newoff == off) 1684 return newoff; 1685 1686 off = newoff; 1687 proto = *nxtp; 1688 } 1689 } 1690 1691 struct ip6aux * 1692 ip6_addaux(struct mbuf *m) 1693 { 1694 struct m_tag *mtag; 1695 1696 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1697 if (!mtag) { 1698 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1699 M_NOWAIT); 1700 if (mtag) { 1701 m_tag_prepend(m, mtag); 1702 bzero(mtag + 1, sizeof(struct ip6aux)); 1703 } 1704 } 1705 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1706 } 1707 1708 struct ip6aux * 1709 ip6_findaux(struct mbuf *m) 1710 { 1711 struct m_tag *mtag; 1712 1713 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1714 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1715 } 1716 1717 void 1718 ip6_delaux(struct mbuf *m) 1719 { 1720 struct m_tag *mtag; 1721 1722 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1723 if (mtag) 1724 m_tag_delete(m, mtag); 1725 } 1726 1727 /* 1728 * System control for IP6 1729 */ 1730 1731 u_char inet6ctlerrmap[PRC_NCMDS] = { 1732 0, 0, 0, 0, 1733 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1734 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1735 EMSGSIZE, EHOSTUNREACH, 0, 0, 1736 0, 0, 0, 0, 1737 ENOPROTOOPT 1738 }; 1739