1 /* $FreeBSD$ */ 2 /* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 66 */ 67 68 #include "opt_ip6fw.h" 69 #include "opt_inet.h" 70 #include "opt_inet6.h" 71 #include "opt_ipsec.h" 72 #include "opt_pfil_hooks.h" 73 #include "opt_random_ip_id.h" 74 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/malloc.h> 78 #include <sys/mbuf.h> 79 #include <sys/proc.h> 80 #include <sys/domain.h> 81 #include <sys/protosw.h> 82 #include <sys/socket.h> 83 #include <sys/socketvar.h> 84 #include <sys/errno.h> 85 #include <sys/time.h> 86 #include <sys/kernel.h> 87 #include <sys/syslog.h> 88 89 #include <net/if.h> 90 #include <net/if_types.h> 91 #include <net/if_dl.h> 92 #include <net/route.h> 93 #include <net/netisr.h> 94 #ifdef PFIL_HOOKS 95 #include <net/pfil.h> 96 #endif 97 98 #include <netinet/in.h> 99 #include <netinet/in_systm.h> 100 #ifdef INET 101 #include <netinet/ip.h> 102 #include <netinet/ip_icmp.h> 103 #endif /* INET */ 104 #include <netinet/ip6.h> 105 #include <netinet6/in6_var.h> 106 #include <netinet6/ip6_var.h> 107 #include <netinet/in_pcb.h> 108 #include <netinet/icmp6.h> 109 #include <netinet6/scope6_var.h> 110 #include <netinet6/in6_ifattach.h> 111 #include <netinet6/nd6.h> 112 #include <netinet6/in6_prefix.h> 113 114 #ifdef IPSEC 115 #include <netinet6/ipsec.h> 116 #ifdef INET6 117 #include <netinet6/ipsec6.h> 118 #endif 119 #endif 120 121 #ifdef FAST_IPSEC 122 #include <netipsec/ipsec.h> 123 #include <netipsec/ipsec6.h> 124 #define IPSEC 125 #endif /* FAST_IPSEC */ 126 127 #include <netinet6/ip6_fw.h> 128 129 #include <netinet6/ip6protosw.h> 130 131 #include <net/net_osdep.h> 132 133 extern struct domain inet6domain; 134 135 u_char ip6_protox[IPPROTO_MAX]; 136 static struct ifqueue ip6intrq; 137 static int ip6qmaxlen = IFQ_MAXLEN; 138 struct in6_ifaddr *in6_ifaddr; 139 140 extern struct callout in6_tmpaddrtimer_ch; 141 142 int ip6_forward_srcrt; /* XXX */ 143 int ip6_sourcecheck; /* XXX */ 144 int ip6_sourcecheck_interval; /* XXX */ 145 146 int ip6_ours_check_algorithm; 147 148 #ifdef PFIL_HOOKS 149 struct pfil_head inet6_pfil_hook; 150 #endif 151 152 /* firewall hooks */ 153 ip6_fw_chk_t *ip6_fw_chk_ptr; 154 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 155 int ip6_fw_enable = 1; 156 157 struct ip6stat ip6stat; 158 159 static void ip6_init2 __P((void *)); 160 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 161 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 162 #ifdef PULLDOWN_TEST 163 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 164 #endif 165 166 /* 167 * IP6 initialization: fill in IP6 protocol switch table. 168 * All protocols not implemented in kernel go to raw IP6 protocol handler. 169 */ 170 void 171 ip6_init() 172 { 173 struct ip6protosw *pr; 174 int i; 175 176 #ifdef DIAGNOSTIC 177 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 178 panic("sizeof(protosw) != sizeof(ip6protosw)"); 179 #endif 180 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 181 if (pr == 0) 182 panic("ip6_init"); 183 for (i = 0; i < IPPROTO_MAX; i++) 184 ip6_protox[i] = pr - inet6sw; 185 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 186 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 187 if (pr->pr_domain->dom_family == PF_INET6 && 188 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 189 ip6_protox[pr->pr_protocol] = pr - inet6sw; 190 #ifdef PFIL_HOOKS 191 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 192 inet6_pfil_hook.ph_af = AF_INET6; 193 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 194 printf("%s: WARNING: unable to register pfil hook, " 195 "error %d\n", __func__, i); 196 #endif /* PFIL_HOOKS */ 197 ip6intrq.ifq_maxlen = ip6qmaxlen; 198 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 199 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 200 scope6_init(); 201 addrsel_policy_init(); 202 nd6_init(); 203 frag6_init(); 204 #ifndef RANDOM_IP_ID 205 ip6_flow_seq = arc4random(); 206 #endif 207 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 208 } 209 210 static void 211 ip6_init2(dummy) 212 void *dummy; 213 { 214 215 /* nd6_timer_init */ 216 callout_init(&nd6_timer_ch, 0); 217 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 218 219 /* router renumbering prefix list maintenance */ 220 callout_init(&in6_rr_timer_ch, 0); 221 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 222 223 /* timer for regeneranation of temporary addresses randomize ID */ 224 callout_init(&in6_tmpaddrtimer_ch, 0); 225 callout_reset(&in6_tmpaddrtimer_ch, 226 (ip6_temp_preferred_lifetime - ip6_desync_factor - 227 ip6_temp_regen_advance) * hz, 228 in6_tmpaddrtimer, NULL); 229 } 230 231 /* cheat */ 232 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 233 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 234 235 extern struct route_in6 ip6_forward_rt; 236 237 void 238 ip6_input(m) 239 struct mbuf *m; 240 { 241 struct ip6_hdr *ip6; 242 int off = sizeof(struct ip6_hdr), nest; 243 u_int32_t plen; 244 u_int32_t rtalert = ~0; 245 int nxt, ours = 0; 246 struct ifnet *deliverifp = NULL; 247 #ifdef PFIL_HOOKS 248 struct in6_addr odst; 249 #endif 250 int srcrt = 0; 251 252 GIANT_REQUIRED; /* XXX for now */ 253 #ifdef IPSEC 254 /* 255 * should the inner packet be considered authentic? 256 * see comment in ah4_input(). 257 */ 258 if (m) { 259 m->m_flags &= ~M_AUTHIPHDR; 260 m->m_flags &= ~M_AUTHIPDGM; 261 } 262 #endif 263 264 /* 265 * make sure we don't have onion peering information into m_tag. 266 */ 267 ip6_delaux(m); 268 269 /* 270 * mbuf statistics 271 */ 272 if (m->m_flags & M_EXT) { 273 if (m->m_next) 274 ip6stat.ip6s_mext2m++; 275 else 276 ip6stat.ip6s_mext1++; 277 } else { 278 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 279 if (m->m_next) { 280 if (m->m_flags & M_LOOP) { 281 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 282 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 283 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 284 else 285 ip6stat.ip6s_m2m[0]++; 286 } else 287 ip6stat.ip6s_m1++; 288 #undef M2MMAX 289 } 290 291 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 292 ip6stat.ip6s_total++; 293 294 #ifndef PULLDOWN_TEST 295 /* 296 * L2 bridge code and some other code can return mbuf chain 297 * that does not conform to KAME requirement. too bad. 298 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 299 */ 300 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 301 struct mbuf *n; 302 303 MGETHDR(n, M_DONTWAIT, MT_HEADER); 304 if (n) 305 M_MOVE_PKTHDR(n, m); 306 if (n && n->m_pkthdr.len > MHLEN) { 307 MCLGET(n, M_DONTWAIT); 308 if ((n->m_flags & M_EXT) == 0) { 309 m_freem(n); 310 n = NULL; 311 } 312 } 313 if (n == NULL) { 314 m_freem(m); 315 return; /* ENOBUFS */ 316 } 317 318 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 319 n->m_len = n->m_pkthdr.len; 320 m_freem(m); 321 m = n; 322 } 323 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 324 #endif 325 326 if (m->m_len < sizeof(struct ip6_hdr)) { 327 struct ifnet *inifp; 328 inifp = m->m_pkthdr.rcvif; 329 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 330 ip6stat.ip6s_toosmall++; 331 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 332 return; 333 } 334 } 335 336 ip6 = mtod(m, struct ip6_hdr *); 337 338 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 339 ip6stat.ip6s_badvers++; 340 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 341 goto bad; 342 } 343 344 #ifdef PFIL_HOOKS 345 /* 346 * Run through list of hooks for input packets. 347 * 348 * NB: Beware of the destination address changing 349 * (e.g. by NAT rewriting). When this happens, 350 * tell ip6_forward to do the right thing. 351 */ 352 odst = ip6->ip6_dst; 353 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 354 return; 355 if (m == NULL) /* consumed by filter */ 356 return; 357 ip6 = mtod(m, struct ip6_hdr *); 358 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 359 #endif /* PFIL_HOOKS */ 360 361 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 362 363 /* 364 * Check with the firewall... 365 */ 366 if (ip6_fw_enable && ip6_fw_chk_ptr) { 367 u_short port = 0; 368 /* If ipfw says divert, we have to just drop packet */ 369 /* use port as a dummy argument */ 370 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 371 m_freem(m); 372 m = NULL; 373 } 374 if (!m) 375 return; 376 } 377 378 /* 379 * Check against address spoofing/corruption. 380 */ 381 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 382 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 383 /* 384 * XXX: "badscope" is not very suitable for a multicast source. 385 */ 386 ip6stat.ip6s_badscope++; 387 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 388 goto bad; 389 } 390 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 391 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 392 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 393 ip6stat.ip6s_badscope++; 394 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 395 goto bad; 396 } 397 398 /* 399 * The following check is not documented in specs. A malicious 400 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 401 * and bypass security checks (act as if it was from 127.0.0.1 by using 402 * IPv6 src ::ffff:127.0.0.1). Be cautious. 403 * 404 * This check chokes if we are in an SIIT cloud. As none of BSDs 405 * support IPv4-less kernel compilation, we cannot support SIIT 406 * environment at all. So, it makes more sense for us to reject any 407 * malicious packets for non-SIIT environment, than try to do a 408 * partial support for SIIT environment. 409 */ 410 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 411 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 412 ip6stat.ip6s_badscope++; 413 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 414 goto bad; 415 } 416 #if 0 417 /* 418 * Reject packets with IPv4 compatible addresses (auto tunnel). 419 * 420 * The code forbids auto tunnel relay case in RFC1933 (the check is 421 * stronger than RFC1933). We may want to re-enable it if mech-xx 422 * is revised to forbid relaying case. 423 */ 424 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 425 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 426 ip6stat.ip6s_badscope++; 427 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 428 goto bad; 429 } 430 #endif 431 432 /* drop packets if interface ID portion is already filled */ 433 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 434 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 435 ip6->ip6_src.s6_addr16[1]) { 436 ip6stat.ip6s_badscope++; 437 goto bad; 438 } 439 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) || 440 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) && 441 ip6->ip6_dst.s6_addr16[1]) { 442 ip6stat.ip6s_badscope++; 443 goto bad; 444 } 445 } 446 447 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 448 ip6->ip6_src.s6_addr16[1] 449 = htons(m->m_pkthdr.rcvif->if_index); 450 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 451 ip6->ip6_dst.s6_addr16[1] 452 = htons(m->m_pkthdr.rcvif->if_index); 453 454 /* 455 * Multicast check 456 */ 457 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 458 struct in6_multi *in6m = 0; 459 460 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 461 /* 462 * See if we belong to the destination multicast group on the 463 * arrival interface. 464 */ 465 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 466 if (in6m) 467 ours = 1; 468 else if (!ip6_mrouter) { 469 ip6stat.ip6s_notmember++; 470 ip6stat.ip6s_cantforward++; 471 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 472 goto bad; 473 } 474 deliverifp = m->m_pkthdr.rcvif; 475 goto hbhcheck; 476 } 477 478 /* 479 * Unicast check 480 */ 481 if (ip6_forward_rt.ro_rt != NULL && 482 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 483 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 484 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 485 ip6stat.ip6s_forward_cachehit++; 486 else { 487 struct sockaddr_in6 *dst6; 488 489 if (ip6_forward_rt.ro_rt) { 490 /* route is down or destination is different */ 491 ip6stat.ip6s_forward_cachemiss++; 492 RTFREE(ip6_forward_rt.ro_rt); 493 ip6_forward_rt.ro_rt = 0; 494 } 495 496 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 497 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 498 dst6->sin6_len = sizeof(struct sockaddr_in6); 499 dst6->sin6_family = AF_INET6; 500 dst6->sin6_addr = ip6->ip6_dst; 501 502 rtalloc((struct route *)&ip6_forward_rt); 503 } 504 505 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 506 507 /* 508 * Accept the packet if the forwarding interface to the destination 509 * according to the routing table is the loopback interface, 510 * unless the associated route has a gateway. 511 * Note that this approach causes to accept a packet if there is a 512 * route to the loopback interface for the destination of the packet. 513 * But we think it's even useful in some situations, e.g. when using 514 * a special daemon which wants to intercept the packet. 515 * 516 * XXX: some OSes automatically make a cloned route for the destination 517 * of an outgoing packet. If the outgoing interface of the packet 518 * is a loopback one, the kernel would consider the packet to be 519 * accepted, even if we have no such address assinged on the interface. 520 * We check the cloned flag of the route entry to reject such cases, 521 * assuming that route entries for our own addresses are not made by 522 * cloning (it should be true because in6_addloop explicitly installs 523 * the host route). However, we might have to do an explicit check 524 * while it would be less efficient. Or, should we rather install a 525 * reject route for such a case? 526 */ 527 if (ip6_forward_rt.ro_rt && 528 (ip6_forward_rt.ro_rt->rt_flags & 529 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 530 #ifdef RTF_WASCLONED 531 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 532 #endif 533 #ifdef RTF_CLONED 534 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 535 #endif 536 #if 0 537 /* 538 * The check below is redundant since the comparison of 539 * the destination and the key of the rtentry has 540 * already done through looking up the routing table. 541 */ 542 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 543 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 544 #endif 545 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 546 struct in6_ifaddr *ia6 = 547 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 548 549 /* 550 * record address information into m_tag. 551 */ 552 (void)ip6_setdstifaddr(m, ia6); 553 554 /* 555 * packets to a tentative, duplicated, or somehow invalid 556 * address must not be accepted. 557 */ 558 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 559 /* this address is ready */ 560 ours = 1; 561 deliverifp = ia6->ia_ifp; /* correct? */ 562 /* Count the packet in the ip address stats */ 563 ia6->ia_ifa.if_ipackets++; 564 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 565 goto hbhcheck; 566 } else { 567 /* address is not ready, so discard the packet. */ 568 nd6log((LOG_INFO, 569 "ip6_input: packet to an unready address %s->%s\n", 570 ip6_sprintf(&ip6->ip6_src), 571 ip6_sprintf(&ip6->ip6_dst))); 572 573 goto bad; 574 } 575 } 576 577 /* 578 * FAITH (Firewall Aided Internet Translator) 579 */ 580 if (ip6_keepfaith) { 581 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 582 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 583 /* XXX do we need more sanity checks? */ 584 ours = 1; 585 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 586 goto hbhcheck; 587 } 588 } 589 590 /* 591 * Now there is no reason to process the packet if it's not our own 592 * and we're not a router. 593 */ 594 if (!ip6_forwarding) { 595 ip6stat.ip6s_cantforward++; 596 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 597 goto bad; 598 } 599 600 hbhcheck: 601 /* 602 * record address information into m_tag, if we don't have one yet. 603 * note that we are unable to record it, if the address is not listed 604 * as our interface address (e.g. multicast addresses, addresses 605 * within FAITH prefixes and such). 606 */ 607 if (deliverifp && !ip6_getdstifaddr(m)) { 608 struct in6_ifaddr *ia6; 609 610 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 611 if (ia6) { 612 if (!ip6_setdstifaddr(m, ia6)) { 613 /* 614 * XXX maybe we should drop the packet here, 615 * as we could not provide enough information 616 * to the upper layers. 617 */ 618 } 619 } 620 } 621 622 /* 623 * Process Hop-by-Hop options header if it's contained. 624 * m may be modified in ip6_hopopts_input(). 625 * If a JumboPayload option is included, plen will also be modified. 626 */ 627 plen = (u_int32_t)ntohs(ip6->ip6_plen); 628 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 629 struct ip6_hbh *hbh; 630 631 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 632 #if 0 /*touches NULL pointer*/ 633 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 634 #endif 635 return; /* m have already been freed */ 636 } 637 638 /* adjust pointer */ 639 ip6 = mtod(m, struct ip6_hdr *); 640 641 /* 642 * if the payload length field is 0 and the next header field 643 * indicates Hop-by-Hop Options header, then a Jumbo Payload 644 * option MUST be included. 645 */ 646 if (ip6->ip6_plen == 0 && plen == 0) { 647 /* 648 * Note that if a valid jumbo payload option is 649 * contained, ip6_hopopts_input() must set a valid 650 * (non-zero) payload length to the variable plen. 651 */ 652 ip6stat.ip6s_badoptions++; 653 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 654 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 655 icmp6_error(m, ICMP6_PARAM_PROB, 656 ICMP6_PARAMPROB_HEADER, 657 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 658 return; 659 } 660 #ifndef PULLDOWN_TEST 661 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 662 hbh = (struct ip6_hbh *)(ip6 + 1); 663 #else 664 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 665 sizeof(struct ip6_hbh)); 666 if (hbh == NULL) { 667 ip6stat.ip6s_tooshort++; 668 return; 669 } 670 #endif 671 nxt = hbh->ip6h_nxt; 672 673 /* 674 * accept the packet if a router alert option is included 675 * and we act as an IPv6 router. 676 */ 677 if (rtalert != ~0 && ip6_forwarding) 678 ours = 1; 679 } else 680 nxt = ip6->ip6_nxt; 681 682 /* 683 * Check that the amount of data in the buffers 684 * is as at least much as the IPv6 header would have us expect. 685 * Trim mbufs if longer than we expect. 686 * Drop packet if shorter than we expect. 687 */ 688 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 689 ip6stat.ip6s_tooshort++; 690 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 691 goto bad; 692 } 693 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 694 if (m->m_len == m->m_pkthdr.len) { 695 m->m_len = sizeof(struct ip6_hdr) + plen; 696 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 697 } else 698 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 699 } 700 701 /* 702 * Forward if desirable. 703 */ 704 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 705 /* 706 * If we are acting as a multicast router, all 707 * incoming multicast packets are passed to the 708 * kernel-level multicast forwarding function. 709 * The packet is returned (relatively) intact; if 710 * ip6_mforward() returns a non-zero value, the packet 711 * must be discarded, else it may be accepted below. 712 */ 713 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 714 ip6stat.ip6s_cantforward++; 715 m_freem(m); 716 return; 717 } 718 if (!ours) { 719 m_freem(m); 720 return; 721 } 722 } else if (!ours) { 723 ip6_forward(m, srcrt); 724 return; 725 } 726 727 ip6 = mtod(m, struct ip6_hdr *); 728 729 /* 730 * Malicious party may be able to use IPv4 mapped addr to confuse 731 * tcp/udp stack and bypass security checks (act as if it was from 732 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 733 * 734 * For SIIT end node behavior, you may want to disable the check. 735 * However, you will become vulnerable to attacks using IPv4 mapped 736 * source. 737 */ 738 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 739 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 740 ip6stat.ip6s_badscope++; 741 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 742 goto bad; 743 } 744 745 /* 746 * Tell launch routine the next header 747 */ 748 ip6stat.ip6s_delivered++; 749 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 750 nest = 0; 751 752 while (nxt != IPPROTO_DONE) { 753 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 754 ip6stat.ip6s_toomanyhdr++; 755 goto bad; 756 } 757 758 /* 759 * protection against faulty packet - there should be 760 * more sanity checks in header chain processing. 761 */ 762 if (m->m_pkthdr.len < off) { 763 ip6stat.ip6s_tooshort++; 764 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 765 goto bad; 766 } 767 768 #ifdef IPSEC 769 /* 770 * enforce IPsec policy checking if we are seeing last header. 771 * note that we do not visit this with protocols with pcb layer 772 * code - like udp/tcp/raw ip. 773 */ 774 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 775 ipsec6_in_reject(m, NULL)) { 776 ipsec6stat.in_polvio++; 777 goto bad; 778 } 779 #endif 780 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 781 } 782 return; 783 bad: 784 m_freem(m); 785 } 786 787 /* 788 * set/grab in6_ifaddr correspond to IPv6 destination address. 789 * XXX backward compatibility wrapper 790 */ 791 static struct ip6aux * 792 ip6_setdstifaddr(m, ia6) 793 struct mbuf *m; 794 struct in6_ifaddr *ia6; 795 { 796 struct ip6aux *ip6a; 797 798 ip6a = ip6_addaux(m); 799 if (ip6a) 800 ip6a->ip6a_dstia6 = ia6; 801 return ip6a; /* NULL if failed to set */ 802 } 803 804 struct in6_ifaddr * 805 ip6_getdstifaddr(m) 806 struct mbuf *m; 807 { 808 struct ip6aux *ip6a; 809 810 ip6a = ip6_findaux(m); 811 if (ip6a) 812 return ip6a->ip6a_dstia6; 813 else 814 return NULL; 815 } 816 817 /* 818 * Hop-by-Hop options header processing. If a valid jumbo payload option is 819 * included, the real payload length will be stored in plenp. 820 */ 821 static int 822 ip6_hopopts_input(plenp, rtalertp, mp, offp) 823 u_int32_t *plenp; 824 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 825 struct mbuf **mp; 826 int *offp; 827 { 828 struct mbuf *m = *mp; 829 int off = *offp, hbhlen; 830 struct ip6_hbh *hbh; 831 u_int8_t *opt; 832 833 /* validation of the length of the header */ 834 #ifndef PULLDOWN_TEST 835 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 836 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 837 hbhlen = (hbh->ip6h_len + 1) << 3; 838 839 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 840 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 841 #else 842 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 843 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 844 if (hbh == NULL) { 845 ip6stat.ip6s_tooshort++; 846 return -1; 847 } 848 hbhlen = (hbh->ip6h_len + 1) << 3; 849 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 850 hbhlen); 851 if (hbh == NULL) { 852 ip6stat.ip6s_tooshort++; 853 return -1; 854 } 855 #endif 856 off += hbhlen; 857 hbhlen -= sizeof(struct ip6_hbh); 858 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 859 860 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 861 hbhlen, rtalertp, plenp) < 0) 862 return (-1); 863 864 *offp = off; 865 *mp = m; 866 return (0); 867 } 868 869 /* 870 * Search header for all Hop-by-hop options and process each option. 871 * This function is separate from ip6_hopopts_input() in order to 872 * handle a case where the sending node itself process its hop-by-hop 873 * options header. In such a case, the function is called from ip6_output(). 874 * 875 * The function assumes that hbh header is located right after the IPv6 header 876 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 877 * opthead + hbhlen is located in continuous memory region. 878 */ 879 int 880 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 881 struct mbuf *m; 882 u_int8_t *opthead; 883 int hbhlen; 884 u_int32_t *rtalertp; 885 u_int32_t *plenp; 886 { 887 struct ip6_hdr *ip6; 888 int optlen = 0; 889 u_int8_t *opt = opthead; 890 u_int16_t rtalert_val; 891 u_int32_t jumboplen; 892 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 893 894 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 895 switch (*opt) { 896 case IP6OPT_PAD1: 897 optlen = 1; 898 break; 899 case IP6OPT_PADN: 900 if (hbhlen < IP6OPT_MINLEN) { 901 ip6stat.ip6s_toosmall++; 902 goto bad; 903 } 904 optlen = *(opt + 1) + 2; 905 break; 906 case IP6OPT_ROUTER_ALERT: 907 /* XXX may need check for alignment */ 908 if (hbhlen < IP6OPT_RTALERT_LEN) { 909 ip6stat.ip6s_toosmall++; 910 goto bad; 911 } 912 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 913 /* XXX stat */ 914 icmp6_error(m, ICMP6_PARAM_PROB, 915 ICMP6_PARAMPROB_HEADER, 916 erroff + opt + 1 - opthead); 917 return (-1); 918 } 919 optlen = IP6OPT_RTALERT_LEN; 920 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 921 *rtalertp = ntohs(rtalert_val); 922 break; 923 case IP6OPT_JUMBO: 924 /* XXX may need check for alignment */ 925 if (hbhlen < IP6OPT_JUMBO_LEN) { 926 ip6stat.ip6s_toosmall++; 927 goto bad; 928 } 929 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 930 /* XXX stat */ 931 icmp6_error(m, ICMP6_PARAM_PROB, 932 ICMP6_PARAMPROB_HEADER, 933 erroff + opt + 1 - opthead); 934 return (-1); 935 } 936 optlen = IP6OPT_JUMBO_LEN; 937 938 /* 939 * IPv6 packets that have non 0 payload length 940 * must not contain a jumbo payload option. 941 */ 942 ip6 = mtod(m, struct ip6_hdr *); 943 if (ip6->ip6_plen) { 944 ip6stat.ip6s_badoptions++; 945 icmp6_error(m, ICMP6_PARAM_PROB, 946 ICMP6_PARAMPROB_HEADER, 947 erroff + opt - opthead); 948 return (-1); 949 } 950 951 /* 952 * We may see jumbolen in unaligned location, so 953 * we'd need to perform bcopy(). 954 */ 955 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 956 jumboplen = (u_int32_t)htonl(jumboplen); 957 958 #if 1 959 /* 960 * if there are multiple jumbo payload options, 961 * *plenp will be non-zero and the packet will be 962 * rejected. 963 * the behavior may need some debate in ipngwg - 964 * multiple options does not make sense, however, 965 * there's no explicit mention in specification. 966 */ 967 if (*plenp != 0) { 968 ip6stat.ip6s_badoptions++; 969 icmp6_error(m, ICMP6_PARAM_PROB, 970 ICMP6_PARAMPROB_HEADER, 971 erroff + opt + 2 - opthead); 972 return (-1); 973 } 974 #endif 975 976 /* 977 * jumbo payload length must be larger than 65535. 978 */ 979 if (jumboplen <= IPV6_MAXPACKET) { 980 ip6stat.ip6s_badoptions++; 981 icmp6_error(m, ICMP6_PARAM_PROB, 982 ICMP6_PARAMPROB_HEADER, 983 erroff + opt + 2 - opthead); 984 return (-1); 985 } 986 *plenp = jumboplen; 987 988 break; 989 default: /* unknown option */ 990 if (hbhlen < IP6OPT_MINLEN) { 991 ip6stat.ip6s_toosmall++; 992 goto bad; 993 } 994 optlen = ip6_unknown_opt(opt, m, 995 erroff + opt - opthead); 996 if (optlen == -1) 997 return (-1); 998 optlen += 2; 999 break; 1000 } 1001 } 1002 1003 return (0); 1004 1005 bad: 1006 m_freem(m); 1007 return (-1); 1008 } 1009 1010 /* 1011 * Unknown option processing. 1012 * The third argument `off' is the offset from the IPv6 header to the option, 1013 * which is necessary if the IPv6 header the and option header and IPv6 header 1014 * is not continuous in order to return an ICMPv6 error. 1015 */ 1016 int 1017 ip6_unknown_opt(optp, m, off) 1018 u_int8_t *optp; 1019 struct mbuf *m; 1020 int off; 1021 { 1022 struct ip6_hdr *ip6; 1023 1024 switch (IP6OPT_TYPE(*optp)) { 1025 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1026 return ((int)*(optp + 1)); 1027 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1028 m_freem(m); 1029 return (-1); 1030 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1031 ip6stat.ip6s_badoptions++; 1032 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1033 return (-1); 1034 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1035 ip6stat.ip6s_badoptions++; 1036 ip6 = mtod(m, struct ip6_hdr *); 1037 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1038 (m->m_flags & (M_BCAST|M_MCAST))) 1039 m_freem(m); 1040 else 1041 icmp6_error(m, ICMP6_PARAM_PROB, 1042 ICMP6_PARAMPROB_OPTION, off); 1043 return (-1); 1044 } 1045 1046 m_freem(m); /* XXX: NOTREACHED */ 1047 return (-1); 1048 } 1049 1050 /* 1051 * Create the "control" list for this pcb. 1052 * The function will not modify mbuf chain at all. 1053 * 1054 * with KAME mbuf chain restriction: 1055 * The routine will be called from upper layer handlers like tcp6_input(). 1056 * Thus the routine assumes that the caller (tcp6_input) have already 1057 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1058 * very first mbuf on the mbuf chain. 1059 */ 1060 void 1061 ip6_savecontrol(in6p, m, mp) 1062 struct inpcb *in6p; 1063 struct mbuf *m, **mp; 1064 { 1065 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1066 struct thread *td = curthread; /* XXX */ 1067 int privileged = 0; 1068 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1069 1070 if (td && !suser(td)) 1071 privileged++; 1072 1073 #ifdef SO_TIMESTAMP 1074 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1075 struct timeval tv; 1076 1077 microtime(&tv); 1078 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1079 SCM_TIMESTAMP, SOL_SOCKET); 1080 if (*mp) 1081 mp = &(*mp)->m_next; 1082 } 1083 #endif 1084 1085 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1086 return; 1087 1088 /* RFC 2292 sec. 5 */ 1089 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1090 struct in6_pktinfo pi6; 1091 1092 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1093 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1094 pi6.ipi6_ifindex = 1095 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1096 1097 *mp = sbcreatecontrol((caddr_t) &pi6, 1098 sizeof(struct in6_pktinfo), 1099 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1100 if (*mp) 1101 mp = &(*mp)->m_next; 1102 } 1103 1104 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1105 int hlim = ip6->ip6_hlim & 0xff; 1106 1107 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1108 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1109 if (*mp) 1110 mp = &(*mp)->m_next; 1111 } 1112 1113 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1114 u_int32_t flowinfo; 1115 int tclass; 1116 1117 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1118 flowinfo >>= 20; 1119 1120 tclass = flowinfo & 0xff; 1121 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1122 IPV6_TCLASS, IPPROTO_IPV6); 1123 if (*mp) 1124 mp = &(*mp)->m_next; 1125 } 1126 1127 /* 1128 * IPV6_HOPOPTS socket option. We require super-user privilege 1129 * for the option, but it might be too strict, since there might 1130 * be some hop-by-hop options which can be returned to normal user. 1131 * See RFC 2292 section 6. 1132 */ 1133 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1134 #ifdef DIAGNOSTIC 1135 if (!privileged) 1136 panic("IN6P_HOPOPTS is set for unprivileged socket"); 1137 #endif 1138 /* 1139 * Check if a hop-by-hop options header is contatined in the 1140 * received packet, and if so, store the options as ancillary 1141 * data. Note that a hop-by-hop options header must be 1142 * just after the IPv6 header, which is assured through the 1143 * IPv6 input processing. 1144 */ 1145 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1146 struct ip6_hbh *hbh; 1147 int hbhlen = 0; 1148 #ifdef PULLDOWN_TEST 1149 struct mbuf *ext; 1150 #endif 1151 1152 #ifndef PULLDOWN_TEST 1153 hbh = (struct ip6_hbh *)(ip6 + 1); 1154 hbhlen = (hbh->ip6h_len + 1) << 3; 1155 #else 1156 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1157 ip6->ip6_nxt); 1158 if (ext == NULL) { 1159 ip6stat.ip6s_tooshort++; 1160 return; 1161 } 1162 hbh = mtod(ext, struct ip6_hbh *); 1163 hbhlen = (hbh->ip6h_len + 1) << 3; 1164 if (hbhlen != ext->m_len) { 1165 m_freem(ext); 1166 ip6stat.ip6s_tooshort++; 1167 return; 1168 } 1169 #endif 1170 1171 /* 1172 * XXX: We copy the whole header even if a 1173 * jumbo payload option is included, the option which 1174 * is to be removed before returning according to 1175 * RFC2292. 1176 * Note: this constraint is removed in 2292bis. 1177 */ 1178 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1179 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1180 IPPROTO_IPV6); 1181 if (*mp) 1182 mp = &(*mp)->m_next; 1183 #ifdef PULLDOWN_TEST 1184 m_freem(ext); 1185 #endif 1186 } 1187 } 1188 1189 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1190 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1191 1192 /* 1193 * Search for destination options headers or routing 1194 * header(s) through the header chain, and stores each 1195 * header as ancillary data. 1196 * Note that the order of the headers remains in 1197 * the chain of ancillary data. 1198 */ 1199 while (1) { /* is explicit loop prevention necessary? */ 1200 struct ip6_ext *ip6e = NULL; 1201 int elen; 1202 #ifdef PULLDOWN_TEST 1203 struct mbuf *ext = NULL; 1204 #endif 1205 1206 /* 1207 * if it is not an extension header, don't try to 1208 * pull it from the chain. 1209 */ 1210 switch (nxt) { 1211 case IPPROTO_DSTOPTS: 1212 case IPPROTO_ROUTING: 1213 case IPPROTO_HOPOPTS: 1214 case IPPROTO_AH: /* is it possible? */ 1215 break; 1216 default: 1217 goto loopend; 1218 } 1219 1220 #ifndef PULLDOWN_TEST 1221 if (off + sizeof(*ip6e) > m->m_len) 1222 goto loopend; 1223 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1224 if (nxt == IPPROTO_AH) 1225 elen = (ip6e->ip6e_len + 2) << 2; 1226 else 1227 elen = (ip6e->ip6e_len + 1) << 3; 1228 if (off + elen > m->m_len) 1229 goto loopend; 1230 #else 1231 ext = ip6_pullexthdr(m, off, nxt); 1232 if (ext == NULL) { 1233 ip6stat.ip6s_tooshort++; 1234 return; 1235 } 1236 ip6e = mtod(ext, struct ip6_ext *); 1237 if (nxt == IPPROTO_AH) 1238 elen = (ip6e->ip6e_len + 2) << 2; 1239 else 1240 elen = (ip6e->ip6e_len + 1) << 3; 1241 if (elen != ext->m_len) { 1242 m_freem(ext); 1243 ip6stat.ip6s_tooshort++; 1244 return; 1245 } 1246 #endif 1247 1248 switch (nxt) { 1249 case IPPROTO_DSTOPTS: 1250 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1251 break; 1252 1253 /* 1254 * We also require super-user privilege for 1255 * the option. See comments on IN6_HOPOPTS. 1256 */ 1257 if (!privileged) 1258 break; 1259 1260 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1261 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1262 IPPROTO_IPV6); 1263 if (*mp) 1264 mp = &(*mp)->m_next; 1265 break; 1266 case IPPROTO_ROUTING: 1267 if (!in6p->in6p_flags & IN6P_RTHDR) 1268 break; 1269 1270 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1271 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1272 IPPROTO_IPV6); 1273 if (*mp) 1274 mp = &(*mp)->m_next; 1275 break; 1276 case IPPROTO_HOPOPTS: 1277 case IPPROTO_AH: /* is it possible? */ 1278 break; 1279 1280 default: 1281 /* 1282 * other cases have been filtered in the above. 1283 * none will visit this case. here we supply 1284 * the code just in case (nxt overwritten or 1285 * other cases). 1286 */ 1287 #ifdef PULLDOWN_TEST 1288 m_freem(ext); 1289 #endif 1290 goto loopend; 1291 1292 } 1293 1294 /* proceed with the next header. */ 1295 off += elen; 1296 nxt = ip6e->ip6e_nxt; 1297 ip6e = NULL; 1298 #ifdef PULLDOWN_TEST 1299 m_freem(ext); 1300 ext = NULL; 1301 #endif 1302 } 1303 loopend: 1304 ; 1305 } 1306 1307 #undef IS2292 1308 } 1309 1310 #ifdef PULLDOWN_TEST 1311 /* 1312 * pull single extension header from mbuf chain. returns single mbuf that 1313 * contains the result, or NULL on error. 1314 */ 1315 static struct mbuf * 1316 ip6_pullexthdr(m, off, nxt) 1317 struct mbuf *m; 1318 size_t off; 1319 int nxt; 1320 { 1321 struct ip6_ext ip6e; 1322 size_t elen; 1323 struct mbuf *n; 1324 1325 #ifdef DIAGNOSTIC 1326 switch (nxt) { 1327 case IPPROTO_DSTOPTS: 1328 case IPPROTO_ROUTING: 1329 case IPPROTO_HOPOPTS: 1330 case IPPROTO_AH: /* is it possible? */ 1331 break; 1332 default: 1333 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1334 } 1335 #endif 1336 1337 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1338 if (nxt == IPPROTO_AH) 1339 elen = (ip6e.ip6e_len + 2) << 2; 1340 else 1341 elen = (ip6e.ip6e_len + 1) << 3; 1342 1343 MGET(n, M_DONTWAIT, MT_DATA); 1344 if (n && elen >= MLEN) { 1345 MCLGET(n, M_DONTWAIT); 1346 if ((n->m_flags & M_EXT) == 0) { 1347 m_free(n); 1348 n = NULL; 1349 } 1350 } 1351 if (!n) 1352 return NULL; 1353 1354 n->m_len = 0; 1355 if (elen >= M_TRAILINGSPACE(n)) { 1356 m_free(n); 1357 return NULL; 1358 } 1359 1360 m_copydata(m, off, elen, mtod(n, caddr_t)); 1361 n->m_len = elen; 1362 return n; 1363 } 1364 #endif 1365 1366 /* 1367 * Get pointer to the previous header followed by the header 1368 * currently processed. 1369 * XXX: This function supposes that 1370 * M includes all headers, 1371 * the next header field and the header length field of each header 1372 * are valid, and 1373 * the sum of each header length equals to OFF. 1374 * Because of these assumptions, this function must be called very 1375 * carefully. Moreover, it will not be used in the near future when 1376 * we develop `neater' mechanism to process extension headers. 1377 */ 1378 char * 1379 ip6_get_prevhdr(m, off) 1380 struct mbuf *m; 1381 int off; 1382 { 1383 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1384 1385 if (off == sizeof(struct ip6_hdr)) 1386 return (&ip6->ip6_nxt); 1387 else { 1388 int len, nxt; 1389 struct ip6_ext *ip6e = NULL; 1390 1391 nxt = ip6->ip6_nxt; 1392 len = sizeof(struct ip6_hdr); 1393 while (len < off) { 1394 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1395 1396 switch (nxt) { 1397 case IPPROTO_FRAGMENT: 1398 len += sizeof(struct ip6_frag); 1399 break; 1400 case IPPROTO_AH: 1401 len += (ip6e->ip6e_len + 2) << 2; 1402 break; 1403 default: 1404 len += (ip6e->ip6e_len + 1) << 3; 1405 break; 1406 } 1407 nxt = ip6e->ip6e_nxt; 1408 } 1409 if (ip6e) 1410 return (&ip6e->ip6e_nxt); 1411 else 1412 return NULL; 1413 } 1414 } 1415 1416 /* 1417 * get next header offset. m will be retained. 1418 */ 1419 int 1420 ip6_nexthdr(m, off, proto, nxtp) 1421 struct mbuf *m; 1422 int off; 1423 int proto; 1424 int *nxtp; 1425 { 1426 struct ip6_hdr ip6; 1427 struct ip6_ext ip6e; 1428 struct ip6_frag fh; 1429 1430 /* just in case */ 1431 if (m == NULL) 1432 panic("ip6_nexthdr: m == NULL"); 1433 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1434 return -1; 1435 1436 switch (proto) { 1437 case IPPROTO_IPV6: 1438 if (m->m_pkthdr.len < off + sizeof(ip6)) 1439 return -1; 1440 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1441 if (nxtp) 1442 *nxtp = ip6.ip6_nxt; 1443 off += sizeof(ip6); 1444 return off; 1445 1446 case IPPROTO_FRAGMENT: 1447 /* 1448 * terminate parsing if it is not the first fragment, 1449 * it does not make sense to parse through it. 1450 */ 1451 if (m->m_pkthdr.len < off + sizeof(fh)) 1452 return -1; 1453 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1454 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1455 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1456 return -1; 1457 if (nxtp) 1458 *nxtp = fh.ip6f_nxt; 1459 off += sizeof(struct ip6_frag); 1460 return off; 1461 1462 case IPPROTO_AH: 1463 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1464 return -1; 1465 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1466 if (nxtp) 1467 *nxtp = ip6e.ip6e_nxt; 1468 off += (ip6e.ip6e_len + 2) << 2; 1469 return off; 1470 1471 case IPPROTO_HOPOPTS: 1472 case IPPROTO_ROUTING: 1473 case IPPROTO_DSTOPTS: 1474 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1475 return -1; 1476 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1477 if (nxtp) 1478 *nxtp = ip6e.ip6e_nxt; 1479 off += (ip6e.ip6e_len + 1) << 3; 1480 return off; 1481 1482 case IPPROTO_NONE: 1483 case IPPROTO_ESP: 1484 case IPPROTO_IPCOMP: 1485 /* give up */ 1486 return -1; 1487 1488 default: 1489 return -1; 1490 } 1491 1492 return -1; 1493 } 1494 1495 /* 1496 * get offset for the last header in the chain. m will be kept untainted. 1497 */ 1498 int 1499 ip6_lasthdr(m, off, proto, nxtp) 1500 struct mbuf *m; 1501 int off; 1502 int proto; 1503 int *nxtp; 1504 { 1505 int newoff; 1506 int nxt; 1507 1508 if (!nxtp) { 1509 nxt = -1; 1510 nxtp = &nxt; 1511 } 1512 while (1) { 1513 newoff = ip6_nexthdr(m, off, proto, nxtp); 1514 if (newoff < 0) 1515 return off; 1516 else if (newoff < off) 1517 return -1; /* invalid */ 1518 else if (newoff == off) 1519 return newoff; 1520 1521 off = newoff; 1522 proto = *nxtp; 1523 } 1524 } 1525 1526 struct ip6aux * 1527 ip6_addaux(m) 1528 struct mbuf *m; 1529 { 1530 struct m_tag *mtag; 1531 1532 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1533 if (!mtag) { 1534 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1535 M_NOWAIT); 1536 if (mtag) { 1537 m_tag_prepend(m, mtag); 1538 bzero(mtag + 1, sizeof(struct ip6aux)); 1539 } 1540 } 1541 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1542 } 1543 1544 struct ip6aux * 1545 ip6_findaux(m) 1546 struct mbuf *m; 1547 { 1548 struct m_tag *mtag; 1549 1550 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1551 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1552 } 1553 1554 void 1555 ip6_delaux(m) 1556 struct mbuf *m; 1557 { 1558 struct m_tag *mtag; 1559 1560 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1561 if (mtag) 1562 m_tag_delete(m, mtag); 1563 } 1564 1565 /* 1566 * System control for IP6 1567 */ 1568 1569 u_char inet6ctlerrmap[PRC_NCMDS] = { 1570 0, 0, 0, 0, 1571 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1572 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1573 EMSGSIZE, EHOSTUNREACH, 0, 0, 1574 0, 0, 0, 0, 1575 ENOPROTOOPT 1576 }; 1577