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]; 122 123 static struct netisr_handler ip6_nh = { 124 .nh_name = "ip6", 125 .nh_handler = ip6_input, 126 .nh_proto = NETISR_IPV6, 127 .nh_policy = NETISR_POLICY_FLOW, 128 }; 129 130 #ifndef VIMAGE 131 #ifndef VIMAGE_GLOBALS 132 struct vnet_inet6 vnet_inet6_0; 133 #endif 134 #endif 135 136 #ifdef VIMAGE_GLOBALS 137 struct in6_ifaddr *in6_ifaddr; 138 struct ip6stat ip6stat; 139 140 extern struct callout in6_tmpaddrtimer_ch; 141 142 extern int dad_init; 143 extern int pmtu_expire; 144 extern int pmtu_probe; 145 extern u_long rip6_sendspace; 146 extern u_long rip6_recvspace; 147 extern int icmp6errppslim; 148 extern int icmp6_nodeinfo; 149 extern int udp6_sendspace; 150 extern int udp6_recvspace; 151 #endif 152 153 struct pfil_head inet6_pfil_hook; 154 155 static void ip6_init2(void *); 156 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 157 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 158 #ifdef PULLDOWN_TEST 159 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 160 #endif 161 162 #ifndef VIMAGE_GLOBALS 163 static void vnet_inet6_register(void); 164 165 static const vnet_modinfo_t vnet_inet6_modinfo = { 166 .vmi_id = VNET_MOD_INET6, 167 .vmi_name = "inet6", 168 .vmi_size = sizeof(struct vnet_inet6), 169 .vmi_dependson = VNET_MOD_INET /* XXX revisit - TCP/UDP needs this? */ 170 }; 171 172 static void 173 vnet_inet6_register(void) 174 { 175 176 vnet_mod_register(&vnet_inet6_modinfo); 177 } 178 179 SYSINIT(inet6, SI_SUB_PROTO_BEGIN, SI_ORDER_FIRST, vnet_inet6_register, 0); 180 #endif 181 182 /* 183 * IP6 initialization: fill in IP6 protocol switch table. 184 * All protocols not implemented in kernel go to raw IP6 protocol handler. 185 */ 186 void 187 ip6_init(void) 188 { 189 INIT_VNET_INET6(curvnet); 190 struct ip6protosw *pr; 191 int i; 192 193 V_in6_maxmtu = 0; 194 #ifdef IP6_AUTO_LINKLOCAL 195 V_ip6_auto_linklocal = IP6_AUTO_LINKLOCAL; 196 #else 197 V_ip6_auto_linklocal = 1; /* enable by default */ 198 #endif 199 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal", 200 &V_ip6_auto_linklocal); 201 202 #ifndef IPV6FORWARDING 203 #ifdef GATEWAY6 204 #define IPV6FORWARDING 1 /* forward IP6 packets not for us */ 205 #else 206 #define IPV6FORWARDING 0 /* don't forward IP6 packets not for us */ 207 #endif /* GATEWAY6 */ 208 #endif /* !IPV6FORWARDING */ 209 210 #ifndef IPV6_SENDREDIRECTS 211 #define IPV6_SENDREDIRECTS 1 212 #endif 213 214 V_ip6_forwarding = IPV6FORWARDING; /* act as router? */ 215 V_ip6_sendredirects = IPV6_SENDREDIRECTS; 216 V_ip6_defhlim = IPV6_DEFHLIM; 217 V_ip6_defmcasthlim = IPV6_DEFAULT_MULTICAST_HOPS; 218 V_ip6_accept_rtadv = 0; /* "IPV6FORWARDING ? 0 : 1" is dangerous */ 219 V_ip6_log_interval = 5; 220 V_ip6_hdrnestlimit = 15; /* How many header options will we process? */ 221 V_ip6_dad_count = 1; /* DupAddrDetectionTransmits */ 222 V_ip6_auto_flowlabel = 1; 223 V_ip6_use_deprecated = 1;/* allow deprecated addr (RFC2462 5.5.4) */ 224 V_ip6_rr_prune = 5; /* router renumbering prefix 225 * walk list every 5 sec. */ 226 V_ip6_mcast_pmtu = 0; /* enable pMTU discovery for multicast? */ 227 V_ip6_v6only = 1; 228 V_ip6_keepfaith = 0; 229 V_ip6_log_time = (time_t)0L; 230 #ifdef IPSTEALTH 231 V_ip6stealth = 0; 232 #endif 233 V_nd6_onlink_ns_rfc4861 = 0; /* allow 'on-link' nd6 NS (RFC 4861) */ 234 235 V_pmtu_expire = 60*10; 236 V_pmtu_probe = 60*2; 237 238 /* raw IP6 parameters */ 239 /* 240 * Nominal space allocated to a raw ip socket. 241 */ 242 #define RIPV6SNDQ 8192 243 #define RIPV6RCVQ 8192 244 V_rip6_sendspace = RIPV6SNDQ; 245 V_rip6_recvspace = RIPV6RCVQ; 246 247 /* ICMPV6 parameters */ 248 V_icmp6_rediraccept = 1; /* accept and process redirects */ 249 V_icmp6_redirtimeout = 10 * 60; /* 10 minutes */ 250 V_icmp6errppslim = 100; /* 100pps */ 251 /* control how to respond to NI queries */ 252 V_icmp6_nodeinfo = (ICMP6_NODEINFO_FQDNOK|ICMP6_NODEINFO_NODEADDROK); 253 254 /* UDP on IP6 parameters */ 255 V_udp6_sendspace = 9216; /* really max datagram size */ 256 V_udp6_recvspace = 40 * (1024 + sizeof(struct sockaddr_in6)); 257 /* 40 1K datagrams */ 258 V_dad_init = 0; 259 260 scope6_init(); 261 addrsel_policy_init(); 262 nd6_init(); 263 frag6_init(); 264 265 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 266 267 /* Skip global initialization stuff for non-default instances. */ 268 if (!IS_DEFAULT_VNET(curvnet)) 269 return; 270 271 #ifdef DIAGNOSTIC 272 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 273 panic("sizeof(protosw) != sizeof(ip6protosw)"); 274 #endif 275 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 276 if (pr == NULL) 277 panic("ip6_init"); 278 279 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ 280 for (i = 0; i < IPPROTO_MAX; i++) 281 ip6_protox[i] = pr - inet6sw; 282 /* 283 * Cycle through IP protocols and put them into the appropriate place 284 * in ip6_protox[]. 285 */ 286 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 287 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 288 if (pr->pr_domain->dom_family == PF_INET6 && 289 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 290 /* Be careful to only index valid IP protocols. */ 291 if (pr->pr_protocol < IPPROTO_MAX) 292 ip6_protox[pr->pr_protocol] = pr - inet6sw; 293 } 294 295 /* Initialize packet filter hooks. */ 296 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 297 inet6_pfil_hook.ph_af = AF_INET6; 298 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 299 printf("%s: WARNING: unable to register pfil hook, " 300 "error %d\n", __func__, i); 301 302 netisr_register(&ip6_nh); 303 } 304 305 #ifdef VIMAGE 306 void 307 ip6_destroy() 308 { 309 INIT_VNET_INET6(curvnet); 310 311 nd6_destroy(); 312 callout_drain(&V_in6_tmpaddrtimer_ch); 313 } 314 #endif 315 316 static int 317 ip6_init2_vnet(const void *unused __unused) 318 { 319 INIT_VNET_INET6(curvnet); 320 321 /* nd6_timer_init */ 322 callout_init(&V_nd6_timer_ch, 0); 323 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet); 324 325 /* timer for regeneranation of temporary addresses randomize ID */ 326 callout_init(&V_in6_tmpaddrtimer_ch, 0); 327 callout_reset(&V_in6_tmpaddrtimer_ch, 328 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor - 329 V_ip6_temp_regen_advance) * hz, 330 in6_tmpaddrtimer, curvnet); 331 332 return (0); 333 } 334 335 static void 336 ip6_init2(void *dummy) 337 { 338 339 ip6_init2_vnet(NULL); 340 } 341 342 /* cheat */ 343 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 344 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 345 346 void 347 ip6_input(struct mbuf *m) 348 { 349 INIT_VNET_NET(curvnet); 350 INIT_VNET_INET6(curvnet); 351 struct ip6_hdr *ip6; 352 int off = sizeof(struct ip6_hdr), nest; 353 u_int32_t plen; 354 u_int32_t rtalert = ~0; 355 int nxt, ours = 0; 356 struct ifnet *deliverifp = NULL, *ifp = NULL; 357 struct in6_addr odst; 358 struct route_in6 rin6; 359 int srcrt = 0; 360 struct llentry *lle = NULL; 361 struct sockaddr_in6 dst6, *dst; 362 363 bzero(&rin6, sizeof(struct route_in6)); 364 #ifdef IPSEC 365 /* 366 * should the inner packet be considered authentic? 367 * see comment in ah4_input(). 368 * NB: m cannot be NULL when passed to the input routine 369 */ 370 371 m->m_flags &= ~M_AUTHIPHDR; 372 m->m_flags &= ~M_AUTHIPDGM; 373 374 #endif /* IPSEC */ 375 376 /* 377 * make sure we don't have onion peering information into m_tag. 378 */ 379 ip6_delaux(m); 380 381 /* 382 * mbuf statistics 383 */ 384 if (m->m_flags & M_EXT) { 385 if (m->m_next) 386 V_ip6stat.ip6s_mext2m++; 387 else 388 V_ip6stat.ip6s_mext1++; 389 } else { 390 #define M2MMAX (sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0])) 391 if (m->m_next) { 392 if (m->m_flags & M_LOOP) { 393 V_ip6stat.ip6s_m2m[V_loif->if_index]++; 394 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 395 V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 396 else 397 V_ip6stat.ip6s_m2m[0]++; 398 } else 399 V_ip6stat.ip6s_m1++; 400 #undef M2MMAX 401 } 402 403 /* drop the packet if IPv6 operation is disabled on the IF */ 404 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 405 m_freem(m); 406 return; 407 } 408 409 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 410 V_ip6stat.ip6s_total++; 411 412 #ifndef PULLDOWN_TEST 413 /* 414 * L2 bridge code and some other code can return mbuf chain 415 * that does not conform to KAME requirement. too bad. 416 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 417 */ 418 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 419 struct mbuf *n; 420 421 MGETHDR(n, M_DONTWAIT, MT_HEADER); 422 if (n) 423 M_MOVE_PKTHDR(n, m); 424 if (n && n->m_pkthdr.len > MHLEN) { 425 MCLGET(n, M_DONTWAIT); 426 if ((n->m_flags & M_EXT) == 0) { 427 m_freem(n); 428 n = NULL; 429 } 430 } 431 if (n == NULL) { 432 m_freem(m); 433 return; /* ENOBUFS */ 434 } 435 436 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 437 n->m_len = n->m_pkthdr.len; 438 m_freem(m); 439 m = n; 440 } 441 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 442 #endif 443 444 if (m->m_len < sizeof(struct ip6_hdr)) { 445 struct ifnet *inifp; 446 inifp = m->m_pkthdr.rcvif; 447 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 448 V_ip6stat.ip6s_toosmall++; 449 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 450 return; 451 } 452 } 453 454 ip6 = mtod(m, struct ip6_hdr *); 455 456 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 457 V_ip6stat.ip6s_badvers++; 458 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 459 goto bad; 460 } 461 462 V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 463 464 /* 465 * Check against address spoofing/corruption. 466 */ 467 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 468 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 469 /* 470 * XXX: "badscope" is not very suitable for a multicast source. 471 */ 472 V_ip6stat.ip6s_badscope++; 473 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 474 goto bad; 475 } 476 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 477 !(m->m_flags & M_LOOP)) { 478 /* 479 * In this case, the packet should come from the loopback 480 * interface. However, we cannot just check the if_flags, 481 * because ip6_mloopback() passes the "actual" interface 482 * as the outgoing/incoming interface. 483 */ 484 V_ip6stat.ip6s_badscope++; 485 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 486 goto bad; 487 } 488 489 #ifdef ALTQ 490 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 491 /* packet is dropped by traffic conditioner */ 492 return; 493 } 494 #endif 495 /* 496 * The following check is not documented in specs. A malicious 497 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 498 * and bypass security checks (act as if it was from 127.0.0.1 by using 499 * IPv6 src ::ffff:127.0.0.1). Be cautious. 500 * 501 * This check chokes if we are in an SIIT cloud. As none of BSDs 502 * support IPv4-less kernel compilation, we cannot support SIIT 503 * environment at all. So, it makes more sense for us to reject any 504 * malicious packets for non-SIIT environment, than try to do a 505 * partial support for SIIT environment. 506 */ 507 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 508 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 509 V_ip6stat.ip6s_badscope++; 510 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 511 goto bad; 512 } 513 #if 0 514 /* 515 * Reject packets with IPv4 compatible addresses (auto tunnel). 516 * 517 * The code forbids auto tunnel relay case in RFC1933 (the check is 518 * stronger than RFC1933). We may want to re-enable it if mech-xx 519 * is revised to forbid relaying case. 520 */ 521 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 522 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 523 V_ip6stat.ip6s_badscope++; 524 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 525 goto bad; 526 } 527 #endif 528 529 /* 530 * Run through list of hooks for input packets. 531 * 532 * NB: Beware of the destination address changing 533 * (e.g. by NAT rewriting). When this happens, 534 * tell ip6_forward to do the right thing. 535 */ 536 odst = ip6->ip6_dst; 537 538 /* Jump over all PFIL processing if hooks are not active. */ 539 if (!PFIL_HOOKED(&inet6_pfil_hook)) 540 goto passin; 541 542 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) 543 return; 544 if (m == NULL) /* consumed by filter */ 545 return; 546 ip6 = mtod(m, struct ip6_hdr *); 547 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 548 549 passin: 550 /* 551 * Disambiguate address scope zones (if there is ambiguity). 552 * We first make sure that the original source or destination address 553 * is not in our internal form for scoped addresses. Such addresses 554 * are not necessarily invalid spec-wise, but we cannot accept them due 555 * to the usage conflict. 556 * in6_setscope() then also checks and rejects the cases where src or 557 * dst are the loopback address and the receiving interface 558 * is not loopback. 559 */ 560 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 561 V_ip6stat.ip6s_badscope++; /* XXX */ 562 goto bad; 563 } 564 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 565 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 566 V_ip6stat.ip6s_badscope++; 567 goto bad; 568 } 569 570 /* 571 * Multicast check. Assume packet is for us to avoid 572 * prematurely taking locks. 573 */ 574 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 575 ours = 1; 576 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 577 deliverifp = m->m_pkthdr.rcvif; 578 goto hbhcheck; 579 } 580 581 /* 582 * Unicast check 583 */ 584 585 bzero(&dst6, sizeof(dst6)); 586 dst6.sin6_family = AF_INET6; 587 dst6.sin6_len = sizeof(struct sockaddr_in6); 588 dst6.sin6_addr = ip6->ip6_dst; 589 ifp = m->m_pkthdr.rcvif; 590 IF_AFDATA_LOCK(ifp); 591 lle = lla_lookup(LLTABLE6(ifp), 0, 592 (struct sockaddr *)&dst6); 593 IF_AFDATA_UNLOCK(ifp); 594 if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) { 595 ours = 1; 596 deliverifp = ifp; 597 LLE_RUNLOCK(lle); 598 goto hbhcheck; 599 } 600 if (lle != NULL) 601 LLE_RUNLOCK(lle); 602 603 dst = &rin6.ro_dst; 604 dst->sin6_len = sizeof(struct sockaddr_in6); 605 dst->sin6_family = AF_INET6; 606 dst->sin6_addr = ip6->ip6_dst; 607 rin6.ro_rt = rtalloc1((struct sockaddr *)dst, 0, 0); 608 if (rin6.ro_rt) 609 RT_UNLOCK(rin6.ro_rt); 610 611 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 612 613 /* 614 * Accept the packet if the forwarding interface to the destination 615 * according to the routing table is the loopback interface, 616 * unless the associated route has a gateway. 617 * Note that this approach causes to accept a packet if there is a 618 * route to the loopback interface for the destination of the packet. 619 * But we think it's even useful in some situations, e.g. when using 620 * a special daemon which wants to intercept the packet. 621 * 622 * XXX: some OSes automatically make a cloned route for the destination 623 * of an outgoing packet. If the outgoing interface of the packet 624 * is a loopback one, the kernel would consider the packet to be 625 * accepted, even if we have no such address assinged on the interface. 626 * We check the cloned flag of the route entry to reject such cases, 627 * assuming that route entries for our own addresses are not made by 628 * cloning (it should be true because in6_addloop explicitly installs 629 * the host route). However, we might have to do an explicit check 630 * while it would be less efficient. Or, should we rather install a 631 * reject route for such a case? 632 */ 633 if (rin6.ro_rt && 634 (rin6.ro_rt->rt_flags & 635 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 636 #ifdef RTF_WASCLONED 637 !(rin6.ro_rt->rt_flags & RTF_WASCLONED) && 638 #endif 639 #ifdef RTF_CLONED 640 !(rin6.ro_rt->rt_flags & RTF_CLONED) && 641 #endif 642 #if 0 643 /* 644 * The check below is redundant since the comparison of 645 * the destination and the key of the rtentry has 646 * already done through looking up the routing table. 647 */ 648 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 649 &rt6_key(rin6.ro_rt)->sin6_addr) 650 #endif 651 rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) { 652 struct in6_ifaddr *ia6 = 653 (struct in6_ifaddr *)rin6.ro_rt->rt_ifa; 654 655 /* 656 * record address information into m_tag. 657 */ 658 (void)ip6_setdstifaddr(m, ia6); 659 660 /* 661 * packets to a tentative, duplicated, or somehow invalid 662 * address must not be accepted. 663 */ 664 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 665 /* this address is ready */ 666 ours = 1; 667 deliverifp = ia6->ia_ifp; /* correct? */ 668 /* Count the packet in the ip address stats */ 669 ia6->ia_ifa.if_ipackets++; 670 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 671 goto hbhcheck; 672 } else { 673 char ip6bufs[INET6_ADDRSTRLEN]; 674 char ip6bufd[INET6_ADDRSTRLEN]; 675 /* address is not ready, so discard the packet. */ 676 nd6log((LOG_INFO, 677 "ip6_input: packet to an unready address %s->%s\n", 678 ip6_sprintf(ip6bufs, &ip6->ip6_src), 679 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 680 681 goto bad; 682 } 683 } 684 685 /* 686 * FAITH (Firewall Aided Internet Translator) 687 */ 688 if (V_ip6_keepfaith) { 689 if (rin6.ro_rt && rin6.ro_rt->rt_ifp && 690 rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) { 691 /* XXX do we need more sanity checks? */ 692 ours = 1; 693 deliverifp = rin6.ro_rt->rt_ifp; /* faith */ 694 goto hbhcheck; 695 } 696 } 697 698 /* 699 * Now there is no reason to process the packet if it's not our own 700 * and we're not a router. 701 */ 702 if (!V_ip6_forwarding) { 703 V_ip6stat.ip6s_cantforward++; 704 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 705 goto bad; 706 } 707 708 hbhcheck: 709 /* 710 * record address information into m_tag, if we don't have one yet. 711 * note that we are unable to record it, if the address is not listed 712 * as our interface address (e.g. multicast addresses, addresses 713 * within FAITH prefixes and such). 714 */ 715 if (deliverifp && !ip6_getdstifaddr(m)) { 716 struct in6_ifaddr *ia6; 717 718 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 719 if (ia6) { 720 if (!ip6_setdstifaddr(m, ia6)) { 721 /* 722 * XXX maybe we should drop the packet here, 723 * as we could not provide enough information 724 * to the upper layers. 725 */ 726 } 727 } 728 } 729 730 /* 731 * Process Hop-by-Hop options header if it's contained. 732 * m may be modified in ip6_hopopts_input(). 733 * If a JumboPayload option is included, plen will also be modified. 734 */ 735 plen = (u_int32_t)ntohs(ip6->ip6_plen); 736 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 737 struct ip6_hbh *hbh; 738 739 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 740 #if 0 /*touches NULL pointer*/ 741 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 742 #endif 743 goto out; /* m have already been freed */ 744 } 745 746 /* adjust pointer */ 747 ip6 = mtod(m, struct ip6_hdr *); 748 749 /* 750 * if the payload length field is 0 and the next header field 751 * indicates Hop-by-Hop Options header, then a Jumbo Payload 752 * option MUST be included. 753 */ 754 if (ip6->ip6_plen == 0 && plen == 0) { 755 /* 756 * Note that if a valid jumbo payload option is 757 * contained, ip6_hopopts_input() must set a valid 758 * (non-zero) payload length to the variable plen. 759 */ 760 V_ip6stat.ip6s_badoptions++; 761 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 762 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 763 icmp6_error(m, ICMP6_PARAM_PROB, 764 ICMP6_PARAMPROB_HEADER, 765 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 766 goto out; 767 } 768 #ifndef PULLDOWN_TEST 769 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 770 hbh = (struct ip6_hbh *)(ip6 + 1); 771 #else 772 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 773 sizeof(struct ip6_hbh)); 774 if (hbh == NULL) { 775 V_ip6stat.ip6s_tooshort++; 776 goto out; 777 } 778 #endif 779 nxt = hbh->ip6h_nxt; 780 781 /* 782 * If we are acting as a router and the packet contains a 783 * router alert option, see if we know the option value. 784 * Currently, we only support the option value for MLD, in which 785 * case we should pass the packet to the multicast routing 786 * daemon. 787 */ 788 if (rtalert != ~0) { 789 switch (rtalert) { 790 case IP6OPT_RTALERT_MLD: 791 if (V_ip6_forwarding) 792 ours = 1; 793 break; 794 default: 795 /* 796 * RFC2711 requires unrecognized values must be 797 * silently ignored. 798 */ 799 break; 800 } 801 } 802 } else 803 nxt = ip6->ip6_nxt; 804 805 /* 806 * Check that the amount of data in the buffers 807 * is as at least much as the IPv6 header would have us expect. 808 * Trim mbufs if longer than we expect. 809 * Drop packet if shorter than we expect. 810 */ 811 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 812 V_ip6stat.ip6s_tooshort++; 813 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 814 goto bad; 815 } 816 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 817 if (m->m_len == m->m_pkthdr.len) { 818 m->m_len = sizeof(struct ip6_hdr) + plen; 819 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 820 } else 821 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 822 } 823 824 /* 825 * Forward if desirable. 826 */ 827 if (V_ip6_mrouter && 828 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 829 /* 830 * If we are acting as a multicast router, all 831 * incoming multicast packets are passed to the 832 * kernel-level multicast forwarding function. 833 * The packet is returned (relatively) intact; if 834 * ip6_mforward() returns a non-zero value, the packet 835 * must be discarded, else it may be accepted below. 836 * 837 * XXX TODO: Check hlim and multicast scope here to avoid 838 * unnecessarily calling into ip6_mforward(). 839 */ 840 if (ip6_mforward && 841 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 842 IP6STAT_INC(ip6s_cantforward); 843 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 844 goto bad; 845 } 846 } else if (!ours) { 847 ip6_forward(m, srcrt); 848 goto out; 849 } 850 851 ip6 = mtod(m, struct ip6_hdr *); 852 853 /* 854 * Malicious party may be able to use IPv4 mapped addr to confuse 855 * tcp/udp stack and bypass security checks (act as if it was from 856 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 857 * 858 * For SIIT end node behavior, you may want to disable the check. 859 * However, you will become vulnerable to attacks using IPv4 mapped 860 * source. 861 */ 862 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 863 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 864 V_ip6stat.ip6s_badscope++; 865 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 866 goto bad; 867 } 868 869 /* 870 * Tell launch routine the next header 871 */ 872 V_ip6stat.ip6s_delivered++; 873 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 874 nest = 0; 875 876 while (nxt != IPPROTO_DONE) { 877 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 878 V_ip6stat.ip6s_toomanyhdr++; 879 goto bad; 880 } 881 882 /* 883 * protection against faulty packet - there should be 884 * more sanity checks in header chain processing. 885 */ 886 if (m->m_pkthdr.len < off) { 887 V_ip6stat.ip6s_tooshort++; 888 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 889 goto bad; 890 } 891 892 #ifdef IPSEC 893 /* 894 * enforce IPsec policy checking if we are seeing last header. 895 * note that we do not visit this with protocols with pcb layer 896 * code - like udp/tcp/raw ip. 897 */ 898 if (ip6_ipsec_input(m, nxt)) 899 goto bad; 900 #endif /* IPSEC */ 901 902 /* 903 * Use mbuf flags to propagate Router Alert option to 904 * ICMPv6 layer, as hop-by-hop options have been stripped. 905 */ 906 if (nxt == IPPROTO_ICMPV6 && rtalert != ~0) 907 m->m_flags |= M_RTALERT_MLD; 908 909 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 910 } 911 goto out; 912 bad: 913 m_freem(m); 914 out: 915 if (rin6.ro_rt) 916 RTFREE(rin6.ro_rt); 917 } 918 919 /* 920 * set/grab in6_ifaddr correspond to IPv6 destination address. 921 * XXX backward compatibility wrapper 922 */ 923 static struct ip6aux * 924 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 925 { 926 struct ip6aux *ip6a; 927 928 ip6a = ip6_addaux(m); 929 if (ip6a) 930 ip6a->ip6a_dstia6 = ia6; 931 return ip6a; /* NULL if failed to set */ 932 } 933 934 struct in6_ifaddr * 935 ip6_getdstifaddr(struct mbuf *m) 936 { 937 struct ip6aux *ip6a; 938 939 ip6a = ip6_findaux(m); 940 if (ip6a) 941 return ip6a->ip6a_dstia6; 942 else 943 return NULL; 944 } 945 946 /* 947 * Hop-by-Hop options header processing. If a valid jumbo payload option is 948 * included, the real payload length will be stored in plenp. 949 * 950 * rtalertp - XXX: should be stored more smart way 951 */ 952 static int 953 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 954 struct mbuf **mp, int *offp) 955 { 956 INIT_VNET_INET6(curvnet); 957 struct mbuf *m = *mp; 958 int off = *offp, hbhlen; 959 struct ip6_hbh *hbh; 960 u_int8_t *opt; 961 962 /* validation of the length of the header */ 963 #ifndef PULLDOWN_TEST 964 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 965 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 966 hbhlen = (hbh->ip6h_len + 1) << 3; 967 968 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 969 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 970 #else 971 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 972 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 973 if (hbh == NULL) { 974 V_ip6stat.ip6s_tooshort++; 975 return -1; 976 } 977 hbhlen = (hbh->ip6h_len + 1) << 3; 978 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 979 hbhlen); 980 if (hbh == NULL) { 981 V_ip6stat.ip6s_tooshort++; 982 return -1; 983 } 984 #endif 985 off += hbhlen; 986 hbhlen -= sizeof(struct ip6_hbh); 987 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 988 989 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 990 hbhlen, rtalertp, plenp) < 0) 991 return (-1); 992 993 *offp = off; 994 *mp = m; 995 return (0); 996 } 997 998 /* 999 * Search header for all Hop-by-hop options and process each option. 1000 * This function is separate from ip6_hopopts_input() in order to 1001 * handle a case where the sending node itself process its hop-by-hop 1002 * options header. In such a case, the function is called from ip6_output(). 1003 * 1004 * The function assumes that hbh header is located right after the IPv6 header 1005 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 1006 * opthead + hbhlen is located in continuous memory region. 1007 */ 1008 int 1009 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 1010 u_int32_t *rtalertp, u_int32_t *plenp) 1011 { 1012 INIT_VNET_INET6(curvnet); 1013 struct ip6_hdr *ip6; 1014 int optlen = 0; 1015 u_int8_t *opt = opthead; 1016 u_int16_t rtalert_val; 1017 u_int32_t jumboplen; 1018 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 1019 1020 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 1021 switch (*opt) { 1022 case IP6OPT_PAD1: 1023 optlen = 1; 1024 break; 1025 case IP6OPT_PADN: 1026 if (hbhlen < IP6OPT_MINLEN) { 1027 V_ip6stat.ip6s_toosmall++; 1028 goto bad; 1029 } 1030 optlen = *(opt + 1) + 2; 1031 break; 1032 case IP6OPT_ROUTER_ALERT: 1033 /* XXX may need check for alignment */ 1034 if (hbhlen < IP6OPT_RTALERT_LEN) { 1035 V_ip6stat.ip6s_toosmall++; 1036 goto bad; 1037 } 1038 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 1039 /* XXX stat */ 1040 icmp6_error(m, ICMP6_PARAM_PROB, 1041 ICMP6_PARAMPROB_HEADER, 1042 erroff + opt + 1 - opthead); 1043 return (-1); 1044 } 1045 optlen = IP6OPT_RTALERT_LEN; 1046 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 1047 *rtalertp = ntohs(rtalert_val); 1048 break; 1049 case IP6OPT_JUMBO: 1050 /* XXX may need check for alignment */ 1051 if (hbhlen < IP6OPT_JUMBO_LEN) { 1052 V_ip6stat.ip6s_toosmall++; 1053 goto bad; 1054 } 1055 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1056 /* XXX stat */ 1057 icmp6_error(m, ICMP6_PARAM_PROB, 1058 ICMP6_PARAMPROB_HEADER, 1059 erroff + opt + 1 - opthead); 1060 return (-1); 1061 } 1062 optlen = IP6OPT_JUMBO_LEN; 1063 1064 /* 1065 * IPv6 packets that have non 0 payload length 1066 * must not contain a jumbo payload option. 1067 */ 1068 ip6 = mtod(m, struct ip6_hdr *); 1069 if (ip6->ip6_plen) { 1070 V_ip6stat.ip6s_badoptions++; 1071 icmp6_error(m, ICMP6_PARAM_PROB, 1072 ICMP6_PARAMPROB_HEADER, 1073 erroff + opt - opthead); 1074 return (-1); 1075 } 1076 1077 /* 1078 * We may see jumbolen in unaligned location, so 1079 * we'd need to perform bcopy(). 1080 */ 1081 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1082 jumboplen = (u_int32_t)htonl(jumboplen); 1083 1084 #if 1 1085 /* 1086 * if there are multiple jumbo payload options, 1087 * *plenp will be non-zero and the packet will be 1088 * rejected. 1089 * the behavior may need some debate in ipngwg - 1090 * multiple options does not make sense, however, 1091 * there's no explicit mention in specification. 1092 */ 1093 if (*plenp != 0) { 1094 V_ip6stat.ip6s_badoptions++; 1095 icmp6_error(m, ICMP6_PARAM_PROB, 1096 ICMP6_PARAMPROB_HEADER, 1097 erroff + opt + 2 - opthead); 1098 return (-1); 1099 } 1100 #endif 1101 1102 /* 1103 * jumbo payload length must be larger than 65535. 1104 */ 1105 if (jumboplen <= IPV6_MAXPACKET) { 1106 V_ip6stat.ip6s_badoptions++; 1107 icmp6_error(m, ICMP6_PARAM_PROB, 1108 ICMP6_PARAMPROB_HEADER, 1109 erroff + opt + 2 - opthead); 1110 return (-1); 1111 } 1112 *plenp = jumboplen; 1113 1114 break; 1115 default: /* unknown option */ 1116 if (hbhlen < IP6OPT_MINLEN) { 1117 V_ip6stat.ip6s_toosmall++; 1118 goto bad; 1119 } 1120 optlen = ip6_unknown_opt(opt, m, 1121 erroff + opt - opthead); 1122 if (optlen == -1) 1123 return (-1); 1124 optlen += 2; 1125 break; 1126 } 1127 } 1128 1129 return (0); 1130 1131 bad: 1132 m_freem(m); 1133 return (-1); 1134 } 1135 1136 /* 1137 * Unknown option processing. 1138 * The third argument `off' is the offset from the IPv6 header to the option, 1139 * which is necessary if the IPv6 header the and option header and IPv6 header 1140 * is not continuous in order to return an ICMPv6 error. 1141 */ 1142 int 1143 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1144 { 1145 INIT_VNET_INET6(curvnet); 1146 struct ip6_hdr *ip6; 1147 1148 switch (IP6OPT_TYPE(*optp)) { 1149 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1150 return ((int)*(optp + 1)); 1151 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1152 m_freem(m); 1153 return (-1); 1154 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1155 V_ip6stat.ip6s_badoptions++; 1156 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1157 return (-1); 1158 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1159 V_ip6stat.ip6s_badoptions++; 1160 ip6 = mtod(m, struct ip6_hdr *); 1161 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1162 (m->m_flags & (M_BCAST|M_MCAST))) 1163 m_freem(m); 1164 else 1165 icmp6_error(m, ICMP6_PARAM_PROB, 1166 ICMP6_PARAMPROB_OPTION, off); 1167 return (-1); 1168 } 1169 1170 m_freem(m); /* XXX: NOTREACHED */ 1171 return (-1); 1172 } 1173 1174 /* 1175 * Create the "control" list for this pcb. 1176 * These functions will not modify mbuf chain at all. 1177 * 1178 * With KAME mbuf chain restriction: 1179 * The routine will be called from upper layer handlers like tcp6_input(). 1180 * Thus the routine assumes that the caller (tcp6_input) have already 1181 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1182 * very first mbuf on the mbuf chain. 1183 * 1184 * ip6_savecontrol_v4 will handle those options that are possible to be 1185 * set on a v4-mapped socket. 1186 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1187 * options and handle the v6-only ones itself. 1188 */ 1189 struct mbuf ** 1190 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1191 int *v4only) 1192 { 1193 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1194 1195 #ifdef SO_TIMESTAMP 1196 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1197 struct timeval tv; 1198 1199 microtime(&tv); 1200 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1201 SCM_TIMESTAMP, SOL_SOCKET); 1202 if (*mp) 1203 mp = &(*mp)->m_next; 1204 } 1205 #endif 1206 1207 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1208 if (v4only != NULL) 1209 *v4only = 1; 1210 return (mp); 1211 } 1212 1213 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1214 /* RFC 2292 sec. 5 */ 1215 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1216 struct in6_pktinfo pi6; 1217 1218 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1219 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1220 pi6.ipi6_ifindex = 1221 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1222 1223 *mp = sbcreatecontrol((caddr_t) &pi6, 1224 sizeof(struct in6_pktinfo), 1225 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1226 if (*mp) 1227 mp = &(*mp)->m_next; 1228 } 1229 1230 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1231 int hlim = ip6->ip6_hlim & 0xff; 1232 1233 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1234 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1235 IPPROTO_IPV6); 1236 if (*mp) 1237 mp = &(*mp)->m_next; 1238 } 1239 1240 if (v4only != NULL) 1241 *v4only = 0; 1242 return (mp); 1243 } 1244 1245 void 1246 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1247 { 1248 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1249 int v4only = 0; 1250 1251 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1252 if (v4only) 1253 return; 1254 1255 if ((in6p->inp_flags & IN6P_TCLASS) != 0) { 1256 u_int32_t flowinfo; 1257 int tclass; 1258 1259 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1260 flowinfo >>= 20; 1261 1262 tclass = flowinfo & 0xff; 1263 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1264 IPV6_TCLASS, IPPROTO_IPV6); 1265 if (*mp) 1266 mp = &(*mp)->m_next; 1267 } 1268 1269 /* 1270 * IPV6_HOPOPTS socket option. Recall that we required super-user 1271 * privilege for the option (see ip6_ctloutput), but it might be too 1272 * strict, since there might be some hop-by-hop options which can be 1273 * returned to normal user. 1274 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1275 */ 1276 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1277 /* 1278 * Check if a hop-by-hop options header is contatined in the 1279 * received packet, and if so, store the options as ancillary 1280 * data. Note that a hop-by-hop options header must be 1281 * just after the IPv6 header, which is assured through the 1282 * IPv6 input processing. 1283 */ 1284 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1285 struct ip6_hbh *hbh; 1286 int hbhlen = 0; 1287 #ifdef PULLDOWN_TEST 1288 struct mbuf *ext; 1289 #endif 1290 1291 #ifndef PULLDOWN_TEST 1292 hbh = (struct ip6_hbh *)(ip6 + 1); 1293 hbhlen = (hbh->ip6h_len + 1) << 3; 1294 #else 1295 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1296 ip6->ip6_nxt); 1297 if (ext == NULL) { 1298 V_ip6stat.ip6s_tooshort++; 1299 return; 1300 } 1301 hbh = mtod(ext, struct ip6_hbh *); 1302 hbhlen = (hbh->ip6h_len + 1) << 3; 1303 if (hbhlen != ext->m_len) { 1304 m_freem(ext); 1305 V_ip6stat.ip6s_tooshort++; 1306 return; 1307 } 1308 #endif 1309 1310 /* 1311 * XXX: We copy the whole header even if a 1312 * jumbo payload option is included, the option which 1313 * is to be removed before returning according to 1314 * RFC2292. 1315 * Note: this constraint is removed in RFC3542 1316 */ 1317 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1318 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1319 IPPROTO_IPV6); 1320 if (*mp) 1321 mp = &(*mp)->m_next; 1322 #ifdef PULLDOWN_TEST 1323 m_freem(ext); 1324 #endif 1325 } 1326 } 1327 1328 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1329 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1330 1331 /* 1332 * Search for destination options headers or routing 1333 * header(s) through the header chain, and stores each 1334 * header as ancillary data. 1335 * Note that the order of the headers remains in 1336 * the chain of ancillary data. 1337 */ 1338 while (1) { /* is explicit loop prevention necessary? */ 1339 struct ip6_ext *ip6e = NULL; 1340 int elen; 1341 #ifdef PULLDOWN_TEST 1342 struct mbuf *ext = NULL; 1343 #endif 1344 1345 /* 1346 * if it is not an extension header, don't try to 1347 * pull it from the chain. 1348 */ 1349 switch (nxt) { 1350 case IPPROTO_DSTOPTS: 1351 case IPPROTO_ROUTING: 1352 case IPPROTO_HOPOPTS: 1353 case IPPROTO_AH: /* is it possible? */ 1354 break; 1355 default: 1356 goto loopend; 1357 } 1358 1359 #ifndef PULLDOWN_TEST 1360 if (off + sizeof(*ip6e) > m->m_len) 1361 goto loopend; 1362 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1363 if (nxt == IPPROTO_AH) 1364 elen = (ip6e->ip6e_len + 2) << 2; 1365 else 1366 elen = (ip6e->ip6e_len + 1) << 3; 1367 if (off + elen > m->m_len) 1368 goto loopend; 1369 #else 1370 ext = ip6_pullexthdr(m, off, nxt); 1371 if (ext == NULL) { 1372 V_ip6stat.ip6s_tooshort++; 1373 return; 1374 } 1375 ip6e = mtod(ext, struct ip6_ext *); 1376 if (nxt == IPPROTO_AH) 1377 elen = (ip6e->ip6e_len + 2) << 2; 1378 else 1379 elen = (ip6e->ip6e_len + 1) << 3; 1380 if (elen != ext->m_len) { 1381 m_freem(ext); 1382 V_ip6stat.ip6s_tooshort++; 1383 return; 1384 } 1385 #endif 1386 1387 switch (nxt) { 1388 case IPPROTO_DSTOPTS: 1389 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1390 break; 1391 1392 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1393 IS2292(in6p, 1394 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1395 IPPROTO_IPV6); 1396 if (*mp) 1397 mp = &(*mp)->m_next; 1398 break; 1399 case IPPROTO_ROUTING: 1400 if (!in6p->inp_flags & IN6P_RTHDR) 1401 break; 1402 1403 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1404 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1405 IPPROTO_IPV6); 1406 if (*mp) 1407 mp = &(*mp)->m_next; 1408 break; 1409 case IPPROTO_HOPOPTS: 1410 case IPPROTO_AH: /* is it possible? */ 1411 break; 1412 1413 default: 1414 /* 1415 * other cases have been filtered in the above. 1416 * none will visit this case. here we supply 1417 * the code just in case (nxt overwritten or 1418 * other cases). 1419 */ 1420 #ifdef PULLDOWN_TEST 1421 m_freem(ext); 1422 #endif 1423 goto loopend; 1424 1425 } 1426 1427 /* proceed with the next header. */ 1428 off += elen; 1429 nxt = ip6e->ip6e_nxt; 1430 ip6e = NULL; 1431 #ifdef PULLDOWN_TEST 1432 m_freem(ext); 1433 ext = NULL; 1434 #endif 1435 } 1436 loopend: 1437 ; 1438 } 1439 } 1440 #undef IS2292 1441 1442 void 1443 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1444 { 1445 struct socket *so; 1446 struct mbuf *m_mtu; 1447 struct ip6_mtuinfo mtuctl; 1448 1449 so = in6p->inp_socket; 1450 1451 if (mtu == NULL) 1452 return; 1453 1454 #ifdef DIAGNOSTIC 1455 if (so == NULL) /* I believe this is impossible */ 1456 panic("ip6_notify_pmtu: socket is NULL"); 1457 #endif 1458 1459 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1460 mtuctl.ip6m_mtu = *mtu; 1461 mtuctl.ip6m_addr = *dst; 1462 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1463 return; 1464 1465 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1466 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1467 return; 1468 1469 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1470 == 0) { 1471 m_freem(m_mtu); 1472 /* XXX: should count statistics */ 1473 } else 1474 sorwakeup(so); 1475 1476 return; 1477 } 1478 1479 #ifdef PULLDOWN_TEST 1480 /* 1481 * pull single extension header from mbuf chain. returns single mbuf that 1482 * contains the result, or NULL on error. 1483 */ 1484 static struct mbuf * 1485 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1486 { 1487 struct ip6_ext ip6e; 1488 size_t elen; 1489 struct mbuf *n; 1490 1491 #ifdef DIAGNOSTIC 1492 switch (nxt) { 1493 case IPPROTO_DSTOPTS: 1494 case IPPROTO_ROUTING: 1495 case IPPROTO_HOPOPTS: 1496 case IPPROTO_AH: /* is it possible? */ 1497 break; 1498 default: 1499 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1500 } 1501 #endif 1502 1503 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1504 if (nxt == IPPROTO_AH) 1505 elen = (ip6e.ip6e_len + 2) << 2; 1506 else 1507 elen = (ip6e.ip6e_len + 1) << 3; 1508 1509 MGET(n, M_DONTWAIT, MT_DATA); 1510 if (n && elen >= MLEN) { 1511 MCLGET(n, M_DONTWAIT); 1512 if ((n->m_flags & M_EXT) == 0) { 1513 m_free(n); 1514 n = NULL; 1515 } 1516 } 1517 if (!n) 1518 return NULL; 1519 1520 n->m_len = 0; 1521 if (elen >= M_TRAILINGSPACE(n)) { 1522 m_free(n); 1523 return NULL; 1524 } 1525 1526 m_copydata(m, off, elen, mtod(n, caddr_t)); 1527 n->m_len = elen; 1528 return n; 1529 } 1530 #endif 1531 1532 /* 1533 * Get pointer to the previous header followed by the header 1534 * currently processed. 1535 * XXX: This function supposes that 1536 * M includes all headers, 1537 * the next header field and the header length field of each header 1538 * are valid, and 1539 * the sum of each header length equals to OFF. 1540 * Because of these assumptions, this function must be called very 1541 * carefully. Moreover, it will not be used in the near future when 1542 * we develop `neater' mechanism to process extension headers. 1543 */ 1544 char * 1545 ip6_get_prevhdr(struct mbuf *m, int off) 1546 { 1547 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1548 1549 if (off == sizeof(struct ip6_hdr)) 1550 return (&ip6->ip6_nxt); 1551 else { 1552 int len, nxt; 1553 struct ip6_ext *ip6e = NULL; 1554 1555 nxt = ip6->ip6_nxt; 1556 len = sizeof(struct ip6_hdr); 1557 while (len < off) { 1558 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1559 1560 switch (nxt) { 1561 case IPPROTO_FRAGMENT: 1562 len += sizeof(struct ip6_frag); 1563 break; 1564 case IPPROTO_AH: 1565 len += (ip6e->ip6e_len + 2) << 2; 1566 break; 1567 default: 1568 len += (ip6e->ip6e_len + 1) << 3; 1569 break; 1570 } 1571 nxt = ip6e->ip6e_nxt; 1572 } 1573 if (ip6e) 1574 return (&ip6e->ip6e_nxt); 1575 else 1576 return NULL; 1577 } 1578 } 1579 1580 /* 1581 * get next header offset. m will be retained. 1582 */ 1583 int 1584 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1585 { 1586 struct ip6_hdr ip6; 1587 struct ip6_ext ip6e; 1588 struct ip6_frag fh; 1589 1590 /* just in case */ 1591 if (m == NULL) 1592 panic("ip6_nexthdr: m == NULL"); 1593 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1594 return -1; 1595 1596 switch (proto) { 1597 case IPPROTO_IPV6: 1598 if (m->m_pkthdr.len < off + sizeof(ip6)) 1599 return -1; 1600 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1601 if (nxtp) 1602 *nxtp = ip6.ip6_nxt; 1603 off += sizeof(ip6); 1604 return off; 1605 1606 case IPPROTO_FRAGMENT: 1607 /* 1608 * terminate parsing if it is not the first fragment, 1609 * it does not make sense to parse through it. 1610 */ 1611 if (m->m_pkthdr.len < off + sizeof(fh)) 1612 return -1; 1613 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1614 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1615 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1616 return -1; 1617 if (nxtp) 1618 *nxtp = fh.ip6f_nxt; 1619 off += sizeof(struct ip6_frag); 1620 return off; 1621 1622 case IPPROTO_AH: 1623 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1624 return -1; 1625 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1626 if (nxtp) 1627 *nxtp = ip6e.ip6e_nxt; 1628 off += (ip6e.ip6e_len + 2) << 2; 1629 return off; 1630 1631 case IPPROTO_HOPOPTS: 1632 case IPPROTO_ROUTING: 1633 case IPPROTO_DSTOPTS: 1634 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1635 return -1; 1636 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1637 if (nxtp) 1638 *nxtp = ip6e.ip6e_nxt; 1639 off += (ip6e.ip6e_len + 1) << 3; 1640 return off; 1641 1642 case IPPROTO_NONE: 1643 case IPPROTO_ESP: 1644 case IPPROTO_IPCOMP: 1645 /* give up */ 1646 return -1; 1647 1648 default: 1649 return -1; 1650 } 1651 1652 return -1; 1653 } 1654 1655 /* 1656 * get offset for the last header in the chain. m will be kept untainted. 1657 */ 1658 int 1659 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1660 { 1661 int newoff; 1662 int nxt; 1663 1664 if (!nxtp) { 1665 nxt = -1; 1666 nxtp = &nxt; 1667 } 1668 while (1) { 1669 newoff = ip6_nexthdr(m, off, proto, nxtp); 1670 if (newoff < 0) 1671 return off; 1672 else if (newoff < off) 1673 return -1; /* invalid */ 1674 else if (newoff == off) 1675 return newoff; 1676 1677 off = newoff; 1678 proto = *nxtp; 1679 } 1680 } 1681 1682 struct ip6aux * 1683 ip6_addaux(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 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1690 M_NOWAIT); 1691 if (mtag) { 1692 m_tag_prepend(m, mtag); 1693 bzero(mtag + 1, sizeof(struct ip6aux)); 1694 } 1695 } 1696 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1697 } 1698 1699 struct ip6aux * 1700 ip6_findaux(struct mbuf *m) 1701 { 1702 struct m_tag *mtag; 1703 1704 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1705 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1706 } 1707 1708 void 1709 ip6_delaux(struct mbuf *m) 1710 { 1711 struct m_tag *mtag; 1712 1713 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1714 if (mtag) 1715 m_tag_delete(m, mtag); 1716 } 1717 1718 /* 1719 * System control for IP6 1720 */ 1721 1722 u_char inet6ctlerrmap[PRC_NCMDS] = { 1723 0, 0, 0, 0, 1724 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1725 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1726 EMSGSIZE, EHOSTUNREACH, 0, 0, 1727 0, 0, 0, 0, 1728 ENOPROTOOPT 1729 }; 1730