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 #include <sys/vimage.h> 84 85 #include <net/if.h> 86 #include <net/if_types.h> 87 #include <net/if_dl.h> 88 #include <net/route.h> 89 #include <net/netisr.h> 90 #include <net/pfil.h> 91 #include <net/vnet.h> 92 93 #include <netinet/in.h> 94 #include <netinet/in_systm.h> 95 #include <net/if_llatbl.h> 96 #ifdef INET 97 #include <netinet/ip.h> 98 #include <netinet/ip_icmp.h> 99 #include <netinet/vinet.h> 100 #endif /* INET */ 101 #include <netinet/ip6.h> 102 #include <netinet6/in6_var.h> 103 #include <netinet6/ip6_var.h> 104 #include <netinet/in_pcb.h> 105 #include <netinet/icmp6.h> 106 #include <netinet6/scope6_var.h> 107 #include <netinet6/in6_ifattach.h> 108 #include <netinet6/nd6.h> 109 #include <netinet6/vinet6.h> 110 111 #ifdef IPSEC 112 #include <netipsec/ipsec.h> 113 #include <netinet6/ip6_ipsec.h> 114 #include <netipsec/ipsec6.h> 115 #endif /* IPSEC */ 116 117 #include <netinet6/ip6protosw.h> 118 119 extern struct domain inet6domain; 120 121 u_char ip6_protox[IPPROTO_MAX]; 122 static struct ifqueue ip6intrq; 123 124 #ifndef VIMAGE 125 #ifndef VIMAGE_GLOBALS 126 struct vnet_inet6 vnet_inet6_0; 127 #endif 128 #endif 129 130 #ifdef VIMAGE_GLOBALS 131 static int ip6qmaxlen; 132 struct in6_ifaddr *in6_ifaddr; 133 struct ip6stat ip6stat; 134 135 extern struct callout in6_tmpaddrtimer_ch; 136 137 extern int dad_init; 138 extern int pmtu_expire; 139 extern int pmtu_probe; 140 extern u_long rip6_sendspace; 141 extern u_long rip6_recvspace; 142 extern int icmp6errppslim; 143 extern int icmp6_nodeinfo; 144 extern int udp6_sendspace; 145 extern int udp6_recvspace; 146 147 extern struct route_in6 ip6_forward_rt; 148 149 int ip6_forward_srcrt; /* XXX */ 150 int ip6_sourcecheck; /* XXX */ 151 int ip6_sourcecheck_interval; /* XXX */ 152 int ip6_ours_check_algorithm; 153 #endif 154 155 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 INIT_VNET_INET6(curvnet); 172 struct ip6protosw *pr; 173 int i; 174 175 V_ip6qmaxlen = IFQ_MAXLEN; 176 V_in6_maxmtu = 0; 177 #ifdef IP6_AUTO_LINKLOCAL 178 V_ip6_auto_linklocal = IP6_AUTO_LINKLOCAL; 179 #else 180 V_ip6_auto_linklocal = 1; /* enable by default */ 181 #endif 182 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal", 183 &V_ip6_auto_linklocal); 184 185 #ifndef IPV6FORWARDING 186 #ifdef GATEWAY6 187 #define IPV6FORWARDING 1 /* forward IP6 packets not for us */ 188 #else 189 #define IPV6FORWARDING 0 /* don't forward IP6 packets not for us */ 190 #endif /* GATEWAY6 */ 191 #endif /* !IPV6FORWARDING */ 192 193 #ifndef IPV6_SENDREDIRECTS 194 #define IPV6_SENDREDIRECTS 1 195 #endif 196 197 V_ip6_forwarding = IPV6FORWARDING; /* act as router? */ 198 V_ip6_sendredirects = IPV6_SENDREDIRECTS; 199 V_ip6_defhlim = IPV6_DEFHLIM; 200 V_ip6_defmcasthlim = IPV6_DEFAULT_MULTICAST_HOPS; 201 V_ip6_accept_rtadv = 0; /* "IPV6FORWARDING ? 0 : 1" is dangerous */ 202 V_ip6_log_interval = 5; 203 V_ip6_hdrnestlimit = 15; /* How many header options will we process? */ 204 V_ip6_dad_count = 1; /* DupAddrDetectionTransmits */ 205 V_ip6_auto_flowlabel = 1; 206 V_ip6_use_deprecated = 1;/* allow deprecated addr (RFC2462 5.5.4) */ 207 V_ip6_rr_prune = 5; /* router renumbering prefix 208 * walk list every 5 sec. */ 209 V_ip6_mcast_pmtu = 0; /* enable pMTU discovery for multicast? */ 210 V_ip6_v6only = 1; 211 V_ip6_keepfaith = 0; 212 V_ip6_log_time = (time_t)0L; 213 #ifdef IPSTEALTH 214 V_ip6stealth = 0; 215 #endif 216 V_nd6_onlink_ns_rfc4861 = 0; /* allow 'on-link' nd6 NS (RFC 4861) */ 217 218 V_pmtu_expire = 60*10; 219 V_pmtu_probe = 60*2; 220 221 /* raw IP6 parameters */ 222 /* 223 * Nominal space allocated to a raw ip socket. 224 */ 225 #define RIPV6SNDQ 8192 226 #define RIPV6RCVQ 8192 227 V_rip6_sendspace = RIPV6SNDQ; 228 V_rip6_recvspace = RIPV6RCVQ; 229 230 /* ICMPV6 parameters */ 231 V_icmp6_rediraccept = 1; /* accept and process redirects */ 232 V_icmp6_redirtimeout = 10 * 60; /* 10 minutes */ 233 V_icmp6errppslim = 100; /* 100pps */ 234 /* control how to respond to NI queries */ 235 V_icmp6_nodeinfo = (ICMP6_NODEINFO_FQDNOK|ICMP6_NODEINFO_NODEADDROK); 236 237 /* UDP on IP6 parameters */ 238 V_udp6_sendspace = 9216; /* really max datagram size */ 239 V_udp6_recvspace = 40 * (1024 + sizeof(struct sockaddr_in6)); 240 /* 40 1K datagrams */ 241 V_dad_init = 0; 242 243 #ifdef DIAGNOSTIC 244 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 245 panic("sizeof(protosw) != sizeof(ip6protosw)"); 246 #endif 247 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 248 if (pr == 0) 249 panic("ip6_init"); 250 251 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ 252 for (i = 0; i < IPPROTO_MAX; i++) 253 ip6_protox[i] = pr - inet6sw; 254 /* 255 * Cycle through IP protocols and put them into the appropriate place 256 * in ip6_protox[]. 257 */ 258 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 259 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 260 if (pr->pr_domain->dom_family == PF_INET6 && 261 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 262 /* Be careful to only index valid IP protocols. */ 263 if (pr->pr_protocol < IPPROTO_MAX) 264 ip6_protox[pr->pr_protocol] = pr - inet6sw; 265 } 266 267 /* Initialize packet filter hooks. */ 268 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 269 inet6_pfil_hook.ph_af = AF_INET6; 270 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 271 printf("%s: WARNING: unable to register pfil hook, " 272 "error %d\n", __func__, i); 273 274 ip6intrq.ifq_maxlen = V_ip6qmaxlen; 275 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 276 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 277 scope6_init(); 278 addrsel_policy_init(); 279 nd6_init(); 280 frag6_init(); 281 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 282 } 283 284 static void 285 ip6_init2(void *dummy) 286 { 287 INIT_VNET_INET6(curvnet); 288 289 /* nd6_timer_init */ 290 callout_init(&V_nd6_timer_ch, 0); 291 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, NULL); 292 293 /* timer for regeneranation of temporary addresses randomize ID */ 294 callout_init(&V_in6_tmpaddrtimer_ch, 0); 295 callout_reset(&V_in6_tmpaddrtimer_ch, 296 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor - 297 V_ip6_temp_regen_advance) * hz, 298 in6_tmpaddrtimer, NULL); 299 } 300 301 /* cheat */ 302 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 303 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 304 305 void 306 ip6_input(struct mbuf *m) 307 { 308 INIT_VNET_NET(curvnet); 309 INIT_VNET_INET6(curvnet); 310 struct ip6_hdr *ip6; 311 int off = sizeof(struct ip6_hdr), nest; 312 u_int32_t plen; 313 u_int32_t rtalert = ~0; 314 int nxt, ours = 0; 315 struct ifnet *deliverifp = NULL, *ifp = NULL; 316 struct in6_addr odst; 317 int srcrt = 0; 318 struct llentry *lle = NULL; 319 struct sockaddr_in6 dst6; 320 321 #ifdef IPSEC 322 /* 323 * should the inner packet be considered authentic? 324 * see comment in ah4_input(). 325 * NB: m cannot be NULL when passed to the input routine 326 */ 327 328 m->m_flags &= ~M_AUTHIPHDR; 329 m->m_flags &= ~M_AUTHIPDGM; 330 331 #endif /* IPSEC */ 332 333 /* 334 * make sure we don't have onion peering information into m_tag. 335 */ 336 ip6_delaux(m); 337 338 /* 339 * mbuf statistics 340 */ 341 if (m->m_flags & M_EXT) { 342 if (m->m_next) 343 V_ip6stat.ip6s_mext2m++; 344 else 345 V_ip6stat.ip6s_mext1++; 346 } else { 347 #define M2MMAX (sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0])) 348 if (m->m_next) { 349 if (m->m_flags & M_LOOP) { 350 V_ip6stat.ip6s_m2m[V_loif[0].if_index]++; /* XXX */ 351 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 352 V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 353 else 354 V_ip6stat.ip6s_m2m[0]++; 355 } else 356 V_ip6stat.ip6s_m1++; 357 #undef M2MMAX 358 } 359 360 /* drop the packet if IPv6 operation is disabled on the IF */ 361 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 362 m_freem(m); 363 return; 364 } 365 366 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 367 V_ip6stat.ip6s_total++; 368 369 #ifndef PULLDOWN_TEST 370 /* 371 * L2 bridge code and some other code can return mbuf chain 372 * that does not conform to KAME requirement. too bad. 373 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 374 */ 375 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 376 struct mbuf *n; 377 378 MGETHDR(n, M_DONTWAIT, MT_HEADER); 379 if (n) 380 M_MOVE_PKTHDR(n, m); 381 if (n && n->m_pkthdr.len > MHLEN) { 382 MCLGET(n, M_DONTWAIT); 383 if ((n->m_flags & M_EXT) == 0) { 384 m_freem(n); 385 n = NULL; 386 } 387 } 388 if (n == NULL) { 389 m_freem(m); 390 return; /* ENOBUFS */ 391 } 392 393 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 394 n->m_len = n->m_pkthdr.len; 395 m_freem(m); 396 m = n; 397 } 398 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 399 #endif 400 401 if (m->m_len < sizeof(struct ip6_hdr)) { 402 struct ifnet *inifp; 403 inifp = m->m_pkthdr.rcvif; 404 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 405 V_ip6stat.ip6s_toosmall++; 406 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 407 return; 408 } 409 } 410 411 ip6 = mtod(m, struct ip6_hdr *); 412 413 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 414 V_ip6stat.ip6s_badvers++; 415 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 416 goto bad; 417 } 418 419 V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 420 421 /* 422 * Check against address spoofing/corruption. 423 */ 424 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 425 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 426 /* 427 * XXX: "badscope" is not very suitable for a multicast source. 428 */ 429 V_ip6stat.ip6s_badscope++; 430 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 431 goto bad; 432 } 433 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 434 !(m->m_flags & M_LOOP)) { 435 /* 436 * In this case, the packet should come from the loopback 437 * interface. However, we cannot just check the if_flags, 438 * because ip6_mloopback() passes the "actual" interface 439 * as the outgoing/incoming interface. 440 */ 441 V_ip6stat.ip6s_badscope++; 442 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 443 goto bad; 444 } 445 446 #ifdef ALTQ 447 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 448 /* packet is dropped by traffic conditioner */ 449 return; 450 } 451 #endif 452 /* 453 * The following check is not documented in specs. A malicious 454 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 455 * and bypass security checks (act as if it was from 127.0.0.1 by using 456 * IPv6 src ::ffff:127.0.0.1). Be cautious. 457 * 458 * This check chokes if we are in an SIIT cloud. As none of BSDs 459 * support IPv4-less kernel compilation, we cannot support SIIT 460 * environment at all. So, it makes more sense for us to reject any 461 * malicious packets for non-SIIT environment, than try to do a 462 * partial support for SIIT environment. 463 */ 464 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 465 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 466 V_ip6stat.ip6s_badscope++; 467 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 468 goto bad; 469 } 470 #if 0 471 /* 472 * Reject packets with IPv4 compatible addresses (auto tunnel). 473 * 474 * The code forbids auto tunnel relay case in RFC1933 (the check is 475 * stronger than RFC1933). We may want to re-enable it if mech-xx 476 * is revised to forbid relaying case. 477 */ 478 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 479 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 480 V_ip6stat.ip6s_badscope++; 481 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 482 goto bad; 483 } 484 #endif 485 486 /* 487 * Run through list of hooks for input packets. 488 * 489 * NB: Beware of the destination address changing 490 * (e.g. by NAT rewriting). When this happens, 491 * tell ip6_forward to do the right thing. 492 */ 493 odst = ip6->ip6_dst; 494 495 /* Jump over all PFIL processing if hooks are not active. */ 496 if (!PFIL_HOOKED(&inet6_pfil_hook)) 497 goto passin; 498 499 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 500 return; 501 if (m == NULL) /* consumed by filter */ 502 return; 503 ip6 = mtod(m, struct ip6_hdr *); 504 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 505 506 passin: 507 /* 508 * Disambiguate address scope zones (if there is ambiguity). 509 * We first make sure that the original source or destination address 510 * is not in our internal form for scoped addresses. Such addresses 511 * are not necessarily invalid spec-wise, but we cannot accept them due 512 * to the usage conflict. 513 * in6_setscope() then also checks and rejects the cases where src or 514 * dst are the loopback address and the receiving interface 515 * is not loopback. 516 */ 517 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 518 V_ip6stat.ip6s_badscope++; /* XXX */ 519 goto bad; 520 } 521 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 522 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 523 V_ip6stat.ip6s_badscope++; 524 goto bad; 525 } 526 527 /* 528 * Multicast check 529 */ 530 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 531 struct in6_multi *in6m = 0; 532 533 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 534 /* 535 * See if we belong to the destination multicast group on the 536 * arrival interface. 537 */ 538 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 539 if (in6m) 540 ours = 1; 541 else if (!ip6_mrouter) { 542 V_ip6stat.ip6s_notmember++; 543 V_ip6stat.ip6s_cantforward++; 544 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 545 goto bad; 546 } 547 deliverifp = m->m_pkthdr.rcvif; 548 goto hbhcheck; 549 } 550 551 /* 552 * Unicast check 553 */ 554 555 bzero(&dst6, sizeof(dst6)); 556 dst6.sin6_family = AF_INET6; 557 dst6.sin6_len = sizeof(struct sockaddr_in6); 558 dst6.sin6_addr = ip6->ip6_dst; 559 ifp = m->m_pkthdr.rcvif; 560 IF_AFDATA_LOCK(ifp); 561 lle = lla_lookup(LLTABLE6(ifp), 0, 562 (struct sockaddr *)&dst6); 563 IF_AFDATA_UNLOCK(ifp); 564 if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) { 565 ours = 1; 566 deliverifp = ifp; 567 LLE_RUNLOCK(lle); 568 goto hbhcheck; 569 } 570 if (lle != NULL) 571 LLE_RUNLOCK(lle); 572 573 if (V_ip6_forward_rt.ro_rt != NULL && 574 (V_ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 575 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 576 &((struct sockaddr_in6 *)(&V_ip6_forward_rt.ro_dst))->sin6_addr)) 577 V_ip6stat.ip6s_forward_cachehit++; 578 else { 579 struct sockaddr_in6 *dst6; 580 581 if (V_ip6_forward_rt.ro_rt) { 582 /* route is down or destination is different */ 583 V_ip6stat.ip6s_forward_cachemiss++; 584 RTFREE(V_ip6_forward_rt.ro_rt); 585 V_ip6_forward_rt.ro_rt = 0; 586 } 587 588 bzero(&V_ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 589 dst6 = (struct sockaddr_in6 *)&V_ip6_forward_rt.ro_dst; 590 dst6->sin6_len = sizeof(struct sockaddr_in6); 591 dst6->sin6_family = AF_INET6; 592 dst6->sin6_addr = ip6->ip6_dst; 593 594 rtalloc((struct route *)&V_ip6_forward_rt); 595 } 596 597 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 598 599 /* 600 * Accept the packet if the forwarding interface to the destination 601 * according to the routing table is the loopback interface, 602 * unless the associated route has a gateway. 603 * Note that this approach causes to accept a packet if there is a 604 * route to the loopback interface for the destination of the packet. 605 * But we think it's even useful in some situations, e.g. when using 606 * a special daemon which wants to intercept the packet. 607 * 608 * XXX: some OSes automatically make a cloned route for the destination 609 * of an outgoing packet. If the outgoing interface of the packet 610 * is a loopback one, the kernel would consider the packet to be 611 * accepted, even if we have no such address assinged on the interface. 612 * We check the cloned flag of the route entry to reject such cases, 613 * assuming that route entries for our own addresses are not made by 614 * cloning (it should be true because in6_addloop explicitly installs 615 * the host route). However, we might have to do an explicit check 616 * while it would be less efficient. Or, should we rather install a 617 * reject route for such a case? 618 */ 619 if (V_ip6_forward_rt.ro_rt && 620 (V_ip6_forward_rt.ro_rt->rt_flags & 621 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 622 #ifdef RTF_WASCLONED 623 !(V_ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 624 #endif 625 #ifdef RTF_CLONED 626 !(V_ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 627 #endif 628 #if 0 629 /* 630 * The check below is redundant since the comparison of 631 * the destination and the key of the rtentry has 632 * already done through looking up the routing table. 633 */ 634 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 635 &rt6_key(V_ip6_forward_rt.ro_rt)->sin6_addr) 636 #endif 637 V_ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 638 struct in6_ifaddr *ia6 = 639 (struct in6_ifaddr *)V_ip6_forward_rt.ro_rt->rt_ifa; 640 641 /* 642 * record address information into m_tag. 643 */ 644 (void)ip6_setdstifaddr(m, ia6); 645 646 /* 647 * packets to a tentative, duplicated, or somehow invalid 648 * address must not be accepted. 649 */ 650 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 651 /* this address is ready */ 652 ours = 1; 653 deliverifp = ia6->ia_ifp; /* correct? */ 654 /* Count the packet in the ip address stats */ 655 ia6->ia_ifa.if_ipackets++; 656 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 657 goto hbhcheck; 658 } else { 659 char ip6bufs[INET6_ADDRSTRLEN]; 660 char ip6bufd[INET6_ADDRSTRLEN]; 661 /* address is not ready, so discard the packet. */ 662 nd6log((LOG_INFO, 663 "ip6_input: packet to an unready address %s->%s\n", 664 ip6_sprintf(ip6bufs, &ip6->ip6_src), 665 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 666 667 goto bad; 668 } 669 } 670 671 /* 672 * FAITH (Firewall Aided Internet Translator) 673 */ 674 if (V_ip6_keepfaith) { 675 if (V_ip6_forward_rt.ro_rt && V_ip6_forward_rt.ro_rt->rt_ifp 676 && V_ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 677 /* XXX do we need more sanity checks? */ 678 ours = 1; 679 deliverifp = V_ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 680 goto hbhcheck; 681 } 682 } 683 684 /* 685 * Now there is no reason to process the packet if it's not our own 686 * and we're not a router. 687 */ 688 if (!V_ip6_forwarding) { 689 V_ip6stat.ip6s_cantforward++; 690 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 691 goto bad; 692 } 693 694 hbhcheck: 695 /* 696 * record address information into m_tag, if we don't have one yet. 697 * note that we are unable to record it, if the address is not listed 698 * as our interface address (e.g. multicast addresses, addresses 699 * within FAITH prefixes and such). 700 */ 701 if (deliverifp && !ip6_getdstifaddr(m)) { 702 struct in6_ifaddr *ia6; 703 704 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 705 if (ia6) { 706 if (!ip6_setdstifaddr(m, ia6)) { 707 /* 708 * XXX maybe we should drop the packet here, 709 * as we could not provide enough information 710 * to the upper layers. 711 */ 712 } 713 } 714 } 715 716 /* 717 * Process Hop-by-Hop options header if it's contained. 718 * m may be modified in ip6_hopopts_input(). 719 * If a JumboPayload option is included, plen will also be modified. 720 */ 721 plen = (u_int32_t)ntohs(ip6->ip6_plen); 722 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 723 struct ip6_hbh *hbh; 724 725 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 726 #if 0 /*touches NULL pointer*/ 727 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 728 #endif 729 return; /* m have already been freed */ 730 } 731 732 /* adjust pointer */ 733 ip6 = mtod(m, struct ip6_hdr *); 734 735 /* 736 * if the payload length field is 0 and the next header field 737 * indicates Hop-by-Hop Options header, then a Jumbo Payload 738 * option MUST be included. 739 */ 740 if (ip6->ip6_plen == 0 && plen == 0) { 741 /* 742 * Note that if a valid jumbo payload option is 743 * contained, ip6_hopopts_input() must set a valid 744 * (non-zero) payload length to the variable plen. 745 */ 746 V_ip6stat.ip6s_badoptions++; 747 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 748 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 749 icmp6_error(m, ICMP6_PARAM_PROB, 750 ICMP6_PARAMPROB_HEADER, 751 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 752 return; 753 } 754 #ifndef PULLDOWN_TEST 755 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 756 hbh = (struct ip6_hbh *)(ip6 + 1); 757 #else 758 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 759 sizeof(struct ip6_hbh)); 760 if (hbh == NULL) { 761 V_ip6stat.ip6s_tooshort++; 762 return; 763 } 764 #endif 765 nxt = hbh->ip6h_nxt; 766 767 /* 768 * If we are acting as a router and the packet contains a 769 * router alert option, see if we know the option value. 770 * Currently, we only support the option value for MLD, in which 771 * case we should pass the packet to the multicast routing 772 * daemon. 773 */ 774 if (rtalert != ~0 && V_ip6_forwarding) { 775 switch (rtalert) { 776 case IP6OPT_RTALERT_MLD: 777 ours = 1; 778 break; 779 default: 780 /* 781 * RFC2711 requires unrecognized values must be 782 * silently ignored. 783 */ 784 break; 785 } 786 } 787 } else 788 nxt = ip6->ip6_nxt; 789 790 /* 791 * Check that the amount of data in the buffers 792 * is as at least much as the IPv6 header would have us expect. 793 * Trim mbufs if longer than we expect. 794 * Drop packet if shorter than we expect. 795 */ 796 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 797 V_ip6stat.ip6s_tooshort++; 798 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 799 goto bad; 800 } 801 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 802 if (m->m_len == m->m_pkthdr.len) { 803 m->m_len = sizeof(struct ip6_hdr) + plen; 804 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 805 } else 806 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 807 } 808 809 /* 810 * Forward if desirable. 811 */ 812 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 813 /* 814 * If we are acting as a multicast router, all 815 * incoming multicast packets are passed to the 816 * kernel-level multicast forwarding function. 817 * The packet is returned (relatively) intact; if 818 * ip6_mforward() returns a non-zero value, the packet 819 * must be discarded, else it may be accepted below. 820 */ 821 if (ip6_mrouter && ip6_mforward && 822 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 823 V_ip6stat.ip6s_cantforward++; 824 m_freem(m); 825 return; 826 } 827 if (!ours) { 828 m_freem(m); 829 return; 830 } 831 } else if (!ours) { 832 ip6_forward(m, srcrt); 833 return; 834 } 835 836 ip6 = mtod(m, struct ip6_hdr *); 837 838 /* 839 * Malicious party may be able to use IPv4 mapped addr to confuse 840 * tcp/udp stack and bypass security checks (act as if it was from 841 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 842 * 843 * For SIIT end node behavior, you may want to disable the check. 844 * However, you will become vulnerable to attacks using IPv4 mapped 845 * source. 846 */ 847 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 848 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 849 V_ip6stat.ip6s_badscope++; 850 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 851 goto bad; 852 } 853 854 /* 855 * Tell launch routine the next header 856 */ 857 V_ip6stat.ip6s_delivered++; 858 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 859 nest = 0; 860 861 while (nxt != IPPROTO_DONE) { 862 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 863 V_ip6stat.ip6s_toomanyhdr++; 864 goto bad; 865 } 866 867 /* 868 * protection against faulty packet - there should be 869 * more sanity checks in header chain processing. 870 */ 871 if (m->m_pkthdr.len < off) { 872 V_ip6stat.ip6s_tooshort++; 873 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 874 goto bad; 875 } 876 877 #ifdef IPSEC 878 /* 879 * enforce IPsec policy checking if we are seeing last header. 880 * note that we do not visit this with protocols with pcb layer 881 * code - like udp/tcp/raw ip. 882 */ 883 if (ip6_ipsec_input(m, nxt)) 884 goto bad; 885 #endif /* IPSEC */ 886 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 887 } 888 return; 889 bad: 890 m_freem(m); 891 } 892 893 /* 894 * set/grab in6_ifaddr correspond to IPv6 destination address. 895 * XXX backward compatibility wrapper 896 */ 897 static struct ip6aux * 898 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 899 { 900 struct ip6aux *ip6a; 901 902 ip6a = ip6_addaux(m); 903 if (ip6a) 904 ip6a->ip6a_dstia6 = ia6; 905 return ip6a; /* NULL if failed to set */ 906 } 907 908 struct in6_ifaddr * 909 ip6_getdstifaddr(struct mbuf *m) 910 { 911 struct ip6aux *ip6a; 912 913 ip6a = ip6_findaux(m); 914 if (ip6a) 915 return ip6a->ip6a_dstia6; 916 else 917 return NULL; 918 } 919 920 /* 921 * Hop-by-Hop options header processing. If a valid jumbo payload option is 922 * included, the real payload length will be stored in plenp. 923 * 924 * rtalertp - XXX: should be stored more smart way 925 */ 926 static int 927 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 928 struct mbuf **mp, int *offp) 929 { 930 INIT_VNET_INET6(curvnet); 931 struct mbuf *m = *mp; 932 int off = *offp, hbhlen; 933 struct ip6_hbh *hbh; 934 u_int8_t *opt; 935 936 /* validation of the length of the header */ 937 #ifndef PULLDOWN_TEST 938 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 939 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 940 hbhlen = (hbh->ip6h_len + 1) << 3; 941 942 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 943 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 944 #else 945 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 946 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 947 if (hbh == NULL) { 948 V_ip6stat.ip6s_tooshort++; 949 return -1; 950 } 951 hbhlen = (hbh->ip6h_len + 1) << 3; 952 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 953 hbhlen); 954 if (hbh == NULL) { 955 V_ip6stat.ip6s_tooshort++; 956 return -1; 957 } 958 #endif 959 off += hbhlen; 960 hbhlen -= sizeof(struct ip6_hbh); 961 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 962 963 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 964 hbhlen, rtalertp, plenp) < 0) 965 return (-1); 966 967 *offp = off; 968 *mp = m; 969 return (0); 970 } 971 972 /* 973 * Search header for all Hop-by-hop options and process each option. 974 * This function is separate from ip6_hopopts_input() in order to 975 * handle a case where the sending node itself process its hop-by-hop 976 * options header. In such a case, the function is called from ip6_output(). 977 * 978 * The function assumes that hbh header is located right after the IPv6 header 979 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 980 * opthead + hbhlen is located in continuous memory region. 981 */ 982 int 983 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 984 u_int32_t *rtalertp, u_int32_t *plenp) 985 { 986 INIT_VNET_INET6(curvnet); 987 struct ip6_hdr *ip6; 988 int optlen = 0; 989 u_int8_t *opt = opthead; 990 u_int16_t rtalert_val; 991 u_int32_t jumboplen; 992 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 993 994 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 995 switch (*opt) { 996 case IP6OPT_PAD1: 997 optlen = 1; 998 break; 999 case IP6OPT_PADN: 1000 if (hbhlen < IP6OPT_MINLEN) { 1001 V_ip6stat.ip6s_toosmall++; 1002 goto bad; 1003 } 1004 optlen = *(opt + 1) + 2; 1005 break; 1006 case IP6OPT_ROUTER_ALERT: 1007 /* XXX may need check for alignment */ 1008 if (hbhlen < IP6OPT_RTALERT_LEN) { 1009 V_ip6stat.ip6s_toosmall++; 1010 goto bad; 1011 } 1012 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 1013 /* XXX stat */ 1014 icmp6_error(m, ICMP6_PARAM_PROB, 1015 ICMP6_PARAMPROB_HEADER, 1016 erroff + opt + 1 - opthead); 1017 return (-1); 1018 } 1019 optlen = IP6OPT_RTALERT_LEN; 1020 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 1021 *rtalertp = ntohs(rtalert_val); 1022 break; 1023 case IP6OPT_JUMBO: 1024 /* XXX may need check for alignment */ 1025 if (hbhlen < IP6OPT_JUMBO_LEN) { 1026 V_ip6stat.ip6s_toosmall++; 1027 goto bad; 1028 } 1029 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1030 /* XXX stat */ 1031 icmp6_error(m, ICMP6_PARAM_PROB, 1032 ICMP6_PARAMPROB_HEADER, 1033 erroff + opt + 1 - opthead); 1034 return (-1); 1035 } 1036 optlen = IP6OPT_JUMBO_LEN; 1037 1038 /* 1039 * IPv6 packets that have non 0 payload length 1040 * must not contain a jumbo payload option. 1041 */ 1042 ip6 = mtod(m, struct ip6_hdr *); 1043 if (ip6->ip6_plen) { 1044 V_ip6stat.ip6s_badoptions++; 1045 icmp6_error(m, ICMP6_PARAM_PROB, 1046 ICMP6_PARAMPROB_HEADER, 1047 erroff + opt - opthead); 1048 return (-1); 1049 } 1050 1051 /* 1052 * We may see jumbolen in unaligned location, so 1053 * we'd need to perform bcopy(). 1054 */ 1055 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1056 jumboplen = (u_int32_t)htonl(jumboplen); 1057 1058 #if 1 1059 /* 1060 * if there are multiple jumbo payload options, 1061 * *plenp will be non-zero and the packet will be 1062 * rejected. 1063 * the behavior may need some debate in ipngwg - 1064 * multiple options does not make sense, however, 1065 * there's no explicit mention in specification. 1066 */ 1067 if (*plenp != 0) { 1068 V_ip6stat.ip6s_badoptions++; 1069 icmp6_error(m, ICMP6_PARAM_PROB, 1070 ICMP6_PARAMPROB_HEADER, 1071 erroff + opt + 2 - opthead); 1072 return (-1); 1073 } 1074 #endif 1075 1076 /* 1077 * jumbo payload length must be larger than 65535. 1078 */ 1079 if (jumboplen <= IPV6_MAXPACKET) { 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 *plenp = jumboplen; 1087 1088 break; 1089 default: /* unknown option */ 1090 if (hbhlen < IP6OPT_MINLEN) { 1091 V_ip6stat.ip6s_toosmall++; 1092 goto bad; 1093 } 1094 optlen = ip6_unknown_opt(opt, m, 1095 erroff + opt - opthead); 1096 if (optlen == -1) 1097 return (-1); 1098 optlen += 2; 1099 break; 1100 } 1101 } 1102 1103 return (0); 1104 1105 bad: 1106 m_freem(m); 1107 return (-1); 1108 } 1109 1110 /* 1111 * Unknown option processing. 1112 * The third argument `off' is the offset from the IPv6 header to the option, 1113 * which is necessary if the IPv6 header the and option header and IPv6 header 1114 * is not continuous in order to return an ICMPv6 error. 1115 */ 1116 int 1117 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1118 { 1119 INIT_VNET_INET6(curvnet); 1120 struct ip6_hdr *ip6; 1121 1122 switch (IP6OPT_TYPE(*optp)) { 1123 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1124 return ((int)*(optp + 1)); 1125 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1126 m_freem(m); 1127 return (-1); 1128 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1129 V_ip6stat.ip6s_badoptions++; 1130 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1131 return (-1); 1132 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1133 V_ip6stat.ip6s_badoptions++; 1134 ip6 = mtod(m, struct ip6_hdr *); 1135 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1136 (m->m_flags & (M_BCAST|M_MCAST))) 1137 m_freem(m); 1138 else 1139 icmp6_error(m, ICMP6_PARAM_PROB, 1140 ICMP6_PARAMPROB_OPTION, off); 1141 return (-1); 1142 } 1143 1144 m_freem(m); /* XXX: NOTREACHED */ 1145 return (-1); 1146 } 1147 1148 /* 1149 * Create the "control" list for this pcb. 1150 * These functions will not modify mbuf chain at all. 1151 * 1152 * With KAME mbuf chain restriction: 1153 * The routine will be called from upper layer handlers like tcp6_input(). 1154 * Thus the routine assumes that the caller (tcp6_input) have already 1155 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1156 * very first mbuf on the mbuf chain. 1157 * 1158 * ip6_savecontrol_v4 will handle those options that are possible to be 1159 * set on a v4-mapped socket. 1160 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1161 * options and handle the v6-only ones itself. 1162 */ 1163 struct mbuf ** 1164 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1165 int *v4only) 1166 { 1167 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1168 1169 #ifdef SO_TIMESTAMP 1170 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1171 struct timeval tv; 1172 1173 microtime(&tv); 1174 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1175 SCM_TIMESTAMP, SOL_SOCKET); 1176 if (*mp) 1177 mp = &(*mp)->m_next; 1178 } 1179 #endif 1180 1181 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1182 if (v4only != NULL) 1183 *v4only = 1; 1184 return (mp); 1185 } 1186 1187 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1188 /* RFC 2292 sec. 5 */ 1189 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1190 struct in6_pktinfo pi6; 1191 1192 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1193 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1194 pi6.ipi6_ifindex = 1195 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1196 1197 *mp = sbcreatecontrol((caddr_t) &pi6, 1198 sizeof(struct in6_pktinfo), 1199 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1200 if (*mp) 1201 mp = &(*mp)->m_next; 1202 } 1203 1204 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1205 int hlim = ip6->ip6_hlim & 0xff; 1206 1207 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1208 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1209 IPPROTO_IPV6); 1210 if (*mp) 1211 mp = &(*mp)->m_next; 1212 } 1213 1214 if (v4only != NULL) 1215 *v4only = 0; 1216 return (mp); 1217 } 1218 1219 void 1220 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1221 { 1222 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1223 int v4only = 0; 1224 1225 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1226 if (v4only) 1227 return; 1228 1229 if ((in6p->inp_flags & IN6P_TCLASS) != 0) { 1230 u_int32_t flowinfo; 1231 int tclass; 1232 1233 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1234 flowinfo >>= 20; 1235 1236 tclass = flowinfo & 0xff; 1237 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1238 IPV6_TCLASS, IPPROTO_IPV6); 1239 if (*mp) 1240 mp = &(*mp)->m_next; 1241 } 1242 1243 /* 1244 * IPV6_HOPOPTS socket option. Recall that we required super-user 1245 * privilege for the option (see ip6_ctloutput), but it might be too 1246 * strict, since there might be some hop-by-hop options which can be 1247 * returned to normal user. 1248 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1249 */ 1250 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1251 /* 1252 * Check if a hop-by-hop options header is contatined in the 1253 * received packet, and if so, store the options as ancillary 1254 * data. Note that a hop-by-hop options header must be 1255 * just after the IPv6 header, which is assured through the 1256 * IPv6 input processing. 1257 */ 1258 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1259 struct ip6_hbh *hbh; 1260 int hbhlen = 0; 1261 #ifdef PULLDOWN_TEST 1262 struct mbuf *ext; 1263 #endif 1264 1265 #ifndef PULLDOWN_TEST 1266 hbh = (struct ip6_hbh *)(ip6 + 1); 1267 hbhlen = (hbh->ip6h_len + 1) << 3; 1268 #else 1269 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1270 ip6->ip6_nxt); 1271 if (ext == NULL) { 1272 V_ip6stat.ip6s_tooshort++; 1273 return; 1274 } 1275 hbh = mtod(ext, struct ip6_hbh *); 1276 hbhlen = (hbh->ip6h_len + 1) << 3; 1277 if (hbhlen != ext->m_len) { 1278 m_freem(ext); 1279 V_ip6stat.ip6s_tooshort++; 1280 return; 1281 } 1282 #endif 1283 1284 /* 1285 * XXX: We copy the whole header even if a 1286 * jumbo payload option is included, the option which 1287 * is to be removed before returning according to 1288 * RFC2292. 1289 * Note: this constraint is removed in RFC3542 1290 */ 1291 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1292 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1293 IPPROTO_IPV6); 1294 if (*mp) 1295 mp = &(*mp)->m_next; 1296 #ifdef PULLDOWN_TEST 1297 m_freem(ext); 1298 #endif 1299 } 1300 } 1301 1302 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1303 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1304 1305 /* 1306 * Search for destination options headers or routing 1307 * header(s) through the header chain, and stores each 1308 * header as ancillary data. 1309 * Note that the order of the headers remains in 1310 * the chain of ancillary data. 1311 */ 1312 while (1) { /* is explicit loop prevention necessary? */ 1313 struct ip6_ext *ip6e = NULL; 1314 int elen; 1315 #ifdef PULLDOWN_TEST 1316 struct mbuf *ext = NULL; 1317 #endif 1318 1319 /* 1320 * if it is not an extension header, don't try to 1321 * pull it from the chain. 1322 */ 1323 switch (nxt) { 1324 case IPPROTO_DSTOPTS: 1325 case IPPROTO_ROUTING: 1326 case IPPROTO_HOPOPTS: 1327 case IPPROTO_AH: /* is it possible? */ 1328 break; 1329 default: 1330 goto loopend; 1331 } 1332 1333 #ifndef PULLDOWN_TEST 1334 if (off + sizeof(*ip6e) > m->m_len) 1335 goto loopend; 1336 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1337 if (nxt == IPPROTO_AH) 1338 elen = (ip6e->ip6e_len + 2) << 2; 1339 else 1340 elen = (ip6e->ip6e_len + 1) << 3; 1341 if (off + elen > m->m_len) 1342 goto loopend; 1343 #else 1344 ext = ip6_pullexthdr(m, off, nxt); 1345 if (ext == NULL) { 1346 V_ip6stat.ip6s_tooshort++; 1347 return; 1348 } 1349 ip6e = mtod(ext, struct ip6_ext *); 1350 if (nxt == IPPROTO_AH) 1351 elen = (ip6e->ip6e_len + 2) << 2; 1352 else 1353 elen = (ip6e->ip6e_len + 1) << 3; 1354 if (elen != ext->m_len) { 1355 m_freem(ext); 1356 V_ip6stat.ip6s_tooshort++; 1357 return; 1358 } 1359 #endif 1360 1361 switch (nxt) { 1362 case IPPROTO_DSTOPTS: 1363 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1364 break; 1365 1366 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1367 IS2292(in6p, 1368 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1369 IPPROTO_IPV6); 1370 if (*mp) 1371 mp = &(*mp)->m_next; 1372 break; 1373 case IPPROTO_ROUTING: 1374 if (!in6p->inp_flags & IN6P_RTHDR) 1375 break; 1376 1377 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1378 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1379 IPPROTO_IPV6); 1380 if (*mp) 1381 mp = &(*mp)->m_next; 1382 break; 1383 case IPPROTO_HOPOPTS: 1384 case IPPROTO_AH: /* is it possible? */ 1385 break; 1386 1387 default: 1388 /* 1389 * other cases have been filtered in the above. 1390 * none will visit this case. here we supply 1391 * the code just in case (nxt overwritten or 1392 * other cases). 1393 */ 1394 #ifdef PULLDOWN_TEST 1395 m_freem(ext); 1396 #endif 1397 goto loopend; 1398 1399 } 1400 1401 /* proceed with the next header. */ 1402 off += elen; 1403 nxt = ip6e->ip6e_nxt; 1404 ip6e = NULL; 1405 #ifdef PULLDOWN_TEST 1406 m_freem(ext); 1407 ext = NULL; 1408 #endif 1409 } 1410 loopend: 1411 ; 1412 } 1413 } 1414 #undef IS2292 1415 1416 void 1417 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1418 { 1419 struct socket *so; 1420 struct mbuf *m_mtu; 1421 struct ip6_mtuinfo mtuctl; 1422 1423 so = in6p->inp_socket; 1424 1425 if (mtu == NULL) 1426 return; 1427 1428 #ifdef DIAGNOSTIC 1429 if (so == NULL) /* I believe this is impossible */ 1430 panic("ip6_notify_pmtu: socket is NULL"); 1431 #endif 1432 1433 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1434 mtuctl.ip6m_mtu = *mtu; 1435 mtuctl.ip6m_addr = *dst; 1436 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1437 return; 1438 1439 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1440 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1441 return; 1442 1443 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1444 == 0) { 1445 m_freem(m_mtu); 1446 /* XXX: should count statistics */ 1447 } else 1448 sorwakeup(so); 1449 1450 return; 1451 } 1452 1453 #ifdef PULLDOWN_TEST 1454 /* 1455 * pull single extension header from mbuf chain. returns single mbuf that 1456 * contains the result, or NULL on error. 1457 */ 1458 static struct mbuf * 1459 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1460 { 1461 struct ip6_ext ip6e; 1462 size_t elen; 1463 struct mbuf *n; 1464 1465 #ifdef DIAGNOSTIC 1466 switch (nxt) { 1467 case IPPROTO_DSTOPTS: 1468 case IPPROTO_ROUTING: 1469 case IPPROTO_HOPOPTS: 1470 case IPPROTO_AH: /* is it possible? */ 1471 break; 1472 default: 1473 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1474 } 1475 #endif 1476 1477 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1478 if (nxt == IPPROTO_AH) 1479 elen = (ip6e.ip6e_len + 2) << 2; 1480 else 1481 elen = (ip6e.ip6e_len + 1) << 3; 1482 1483 MGET(n, M_DONTWAIT, MT_DATA); 1484 if (n && elen >= MLEN) { 1485 MCLGET(n, M_DONTWAIT); 1486 if ((n->m_flags & M_EXT) == 0) { 1487 m_free(n); 1488 n = NULL; 1489 } 1490 } 1491 if (!n) 1492 return NULL; 1493 1494 n->m_len = 0; 1495 if (elen >= M_TRAILINGSPACE(n)) { 1496 m_free(n); 1497 return NULL; 1498 } 1499 1500 m_copydata(m, off, elen, mtod(n, caddr_t)); 1501 n->m_len = elen; 1502 return n; 1503 } 1504 #endif 1505 1506 /* 1507 * Get pointer to the previous header followed by the header 1508 * currently processed. 1509 * XXX: This function supposes that 1510 * M includes all headers, 1511 * the next header field and the header length field of each header 1512 * are valid, and 1513 * the sum of each header length equals to OFF. 1514 * Because of these assumptions, this function must be called very 1515 * carefully. Moreover, it will not be used in the near future when 1516 * we develop `neater' mechanism to process extension headers. 1517 */ 1518 char * 1519 ip6_get_prevhdr(struct mbuf *m, int off) 1520 { 1521 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1522 1523 if (off == sizeof(struct ip6_hdr)) 1524 return (&ip6->ip6_nxt); 1525 else { 1526 int len, nxt; 1527 struct ip6_ext *ip6e = NULL; 1528 1529 nxt = ip6->ip6_nxt; 1530 len = sizeof(struct ip6_hdr); 1531 while (len < off) { 1532 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1533 1534 switch (nxt) { 1535 case IPPROTO_FRAGMENT: 1536 len += sizeof(struct ip6_frag); 1537 break; 1538 case IPPROTO_AH: 1539 len += (ip6e->ip6e_len + 2) << 2; 1540 break; 1541 default: 1542 len += (ip6e->ip6e_len + 1) << 3; 1543 break; 1544 } 1545 nxt = ip6e->ip6e_nxt; 1546 } 1547 if (ip6e) 1548 return (&ip6e->ip6e_nxt); 1549 else 1550 return NULL; 1551 } 1552 } 1553 1554 /* 1555 * get next header offset. m will be retained. 1556 */ 1557 int 1558 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1559 { 1560 struct ip6_hdr ip6; 1561 struct ip6_ext ip6e; 1562 struct ip6_frag fh; 1563 1564 /* just in case */ 1565 if (m == NULL) 1566 panic("ip6_nexthdr: m == NULL"); 1567 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1568 return -1; 1569 1570 switch (proto) { 1571 case IPPROTO_IPV6: 1572 if (m->m_pkthdr.len < off + sizeof(ip6)) 1573 return -1; 1574 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1575 if (nxtp) 1576 *nxtp = ip6.ip6_nxt; 1577 off += sizeof(ip6); 1578 return off; 1579 1580 case IPPROTO_FRAGMENT: 1581 /* 1582 * terminate parsing if it is not the first fragment, 1583 * it does not make sense to parse through it. 1584 */ 1585 if (m->m_pkthdr.len < off + sizeof(fh)) 1586 return -1; 1587 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1588 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1589 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1590 return -1; 1591 if (nxtp) 1592 *nxtp = fh.ip6f_nxt; 1593 off += sizeof(struct ip6_frag); 1594 return off; 1595 1596 case IPPROTO_AH: 1597 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1598 return -1; 1599 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1600 if (nxtp) 1601 *nxtp = ip6e.ip6e_nxt; 1602 off += (ip6e.ip6e_len + 2) << 2; 1603 return off; 1604 1605 case IPPROTO_HOPOPTS: 1606 case IPPROTO_ROUTING: 1607 case IPPROTO_DSTOPTS: 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 + 1) << 3; 1614 return off; 1615 1616 case IPPROTO_NONE: 1617 case IPPROTO_ESP: 1618 case IPPROTO_IPCOMP: 1619 /* give up */ 1620 return -1; 1621 1622 default: 1623 return -1; 1624 } 1625 1626 return -1; 1627 } 1628 1629 /* 1630 * get offset for the last header in the chain. m will be kept untainted. 1631 */ 1632 int 1633 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1634 { 1635 int newoff; 1636 int nxt; 1637 1638 if (!nxtp) { 1639 nxt = -1; 1640 nxtp = &nxt; 1641 } 1642 while (1) { 1643 newoff = ip6_nexthdr(m, off, proto, nxtp); 1644 if (newoff < 0) 1645 return off; 1646 else if (newoff < off) 1647 return -1; /* invalid */ 1648 else if (newoff == off) 1649 return newoff; 1650 1651 off = newoff; 1652 proto = *nxtp; 1653 } 1654 } 1655 1656 struct ip6aux * 1657 ip6_addaux(struct mbuf *m) 1658 { 1659 struct m_tag *mtag; 1660 1661 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1662 if (!mtag) { 1663 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1664 M_NOWAIT); 1665 if (mtag) { 1666 m_tag_prepend(m, mtag); 1667 bzero(mtag + 1, sizeof(struct ip6aux)); 1668 } 1669 } 1670 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1671 } 1672 1673 struct ip6aux * 1674 ip6_findaux(struct mbuf *m) 1675 { 1676 struct m_tag *mtag; 1677 1678 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1679 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1680 } 1681 1682 void 1683 ip6_delaux(struct mbuf *m) 1684 { 1685 struct m_tag *mtag; 1686 1687 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1688 if (mtag) 1689 m_tag_delete(m, mtag); 1690 } 1691 1692 /* 1693 * System control for IP6 1694 */ 1695 1696 u_char inet6ctlerrmap[PRC_NCMDS] = { 1697 0, 0, 0, 0, 1698 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1699 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1700 EMSGSIZE, EHOSTUNREACH, 0, 0, 1701 0, 0, 0, 0, 1702 ENOPROTOOPT 1703 }; 1704