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/in6_ifattach.h> 110 #include <netinet6/nd6.h> 111 #include <netinet6/in6_prefix.h> 112 113 #ifdef IPSEC 114 #include <netinet6/ipsec.h> 115 #ifdef INET6 116 #include <netinet6/ipsec6.h> 117 #endif 118 #endif 119 120 #ifdef FAST_IPSEC 121 #include <netipsec/ipsec.h> 122 #include <netipsec/ipsec6.h> 123 #define IPSEC 124 #endif /* FAST_IPSEC */ 125 126 #include <netinet6/ip6_fw.h> 127 128 #include <netinet6/ip6protosw.h> 129 130 #include <net/net_osdep.h> 131 132 extern struct domain inet6domain; 133 134 u_char ip6_protox[IPPROTO_MAX]; 135 static struct ifqueue ip6intrq; 136 static int ip6qmaxlen = IFQ_MAXLEN; 137 struct in6_ifaddr *in6_ifaddr; 138 139 extern struct callout in6_tmpaddrtimer_ch; 140 141 int ip6_forward_srcrt; /* XXX */ 142 int ip6_sourcecheck; /* XXX */ 143 int ip6_sourcecheck_interval; /* XXX */ 144 145 int ip6_ours_check_algorithm; 146 147 #ifdef PFIL_HOOKS 148 struct pfil_head inet6_pfil_hook; 149 #endif 150 151 /* firewall hooks */ 152 ip6_fw_chk_t *ip6_fw_chk_ptr; 153 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 154 int ip6_fw_enable = 1; 155 156 struct ip6stat ip6stat; 157 158 static void ip6_init2 __P((void *)); 159 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 160 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 161 #ifdef PULLDOWN_TEST 162 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 163 #endif 164 165 166 /* 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); 200 nd6_init(); 201 frag6_init(); 202 #ifndef RANDOM_IP_ID 203 ip6_flow_seq = arc4random(); 204 #endif 205 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 206 } 207 208 static void 209 ip6_init2(dummy) 210 void *dummy; 211 { 212 213 /* 214 * to route local address of p2p link to loopback, 215 * assign loopback address first. 216 */ 217 in6_ifattach(&loif[0], NULL); 218 219 /* nd6_timer_init */ 220 callout_init(&nd6_timer_ch, 0); 221 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 222 223 /* router renumbering prefix list maintenance */ 224 callout_init(&in6_rr_timer_ch, 0); 225 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 226 227 /* timer for regeneranation of temporary addresses randomize ID */ 228 callout_reset(&in6_tmpaddrtimer_ch, 229 (ip6_temp_preferred_lifetime - ip6_desync_factor - 230 ip6_temp_regen_advance) * hz, 231 in6_tmpaddrtimer, NULL); 232 } 233 234 /* cheat */ 235 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 236 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 237 238 extern struct route_in6 ip6_forward_rt; 239 240 void 241 ip6_input(m) 242 struct mbuf *m; 243 { 244 struct ip6_hdr *ip6; 245 int off = sizeof(struct ip6_hdr), nest; 246 u_int32_t plen; 247 u_int32_t rtalert = ~0; 248 int nxt, ours = 0; 249 struct ifnet *deliverifp = NULL; 250 251 #ifdef IPSEC 252 /* 253 * should the inner packet be considered authentic? 254 * see comment in ah4_input(). 255 */ 256 if (m) { 257 m->m_flags &= ~M_AUTHIPHDR; 258 m->m_flags &= ~M_AUTHIPDGM; 259 } 260 #endif 261 262 /* 263 * make sure we don't have onion peering information into m_aux. 264 */ 265 ip6_delaux(m); 266 267 /* 268 * mbuf statistics 269 */ 270 if (m->m_flags & M_EXT) { 271 if (m->m_next) 272 ip6stat.ip6s_mext2m++; 273 else 274 ip6stat.ip6s_mext1++; 275 } else { 276 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 277 if (m->m_next) { 278 if (m->m_flags & M_LOOP) { 279 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 280 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 281 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 282 else 283 ip6stat.ip6s_m2m[0]++; 284 } else 285 ip6stat.ip6s_m1++; 286 #undef M2MMAX 287 } 288 289 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 290 ip6stat.ip6s_total++; 291 292 #ifndef PULLDOWN_TEST 293 /* 294 * L2 bridge code and some other code can return mbuf chain 295 * that does not conform to KAME requirement. too bad. 296 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 297 */ 298 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 299 struct mbuf *n; 300 301 MGETHDR(n, M_DONTWAIT, MT_HEADER); 302 if (n) 303 M_MOVE_PKTHDR(n, m); 304 if (n && n->m_pkthdr.len > MHLEN) { 305 MCLGET(n, M_DONTWAIT); 306 if ((n->m_flags & M_EXT) == 0) { 307 m_freem(n); 308 n = NULL; 309 } 310 } 311 if (n == NULL) { 312 m_freem(m); 313 return; /*ENOBUFS*/ 314 } 315 316 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 317 n->m_len = n->m_pkthdr.len; 318 m_freem(m); 319 m = n; 320 } 321 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); 322 #endif 323 324 if (m->m_len < sizeof(struct ip6_hdr)) { 325 struct ifnet *inifp; 326 inifp = m->m_pkthdr.rcvif; 327 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) { 328 ip6stat.ip6s_toosmall++; 329 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 330 return; 331 } 332 } 333 334 ip6 = mtod(m, struct ip6_hdr *); 335 336 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 337 ip6stat.ip6s_badvers++; 338 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 339 goto bad; 340 } 341 342 #ifdef PFIL_HOOKS 343 /* 344 * Run through list of hooks for input packets. 345 */ 346 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 347 return; 348 if (m == NULL) /* consumed by filter */ 349 return; 350 ip6 = mtod(m, struct ip6_hdr *); 351 #endif /* PFIL_HOOKS */ 352 353 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 354 355 /* 356 * Check with the firewall... 357 */ 358 if (ip6_fw_enable && ip6_fw_chk_ptr) { 359 u_short port = 0; 360 /* If ipfw says divert, we have to just drop packet */ 361 /* use port as a dummy argument */ 362 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 363 m_freem(m); 364 m = NULL; 365 } 366 if (!m) 367 return; 368 } 369 370 /* 371 * Check against address spoofing/corruption. 372 */ 373 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 374 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 375 /* 376 * XXX: "badscope" is not very suitable for a multicast source. 377 */ 378 ip6stat.ip6s_badscope++; 379 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 380 goto bad; 381 } 382 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 383 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 384 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 385 ip6stat.ip6s_badscope++; 386 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 387 goto bad; 388 } 389 390 /* 391 * The following check is not documented in specs. A malicious 392 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 393 * and bypass security checks (act as if it was from 127.0.0.1 by using 394 * IPv6 src ::ffff:127.0.0.1). Be cautious. 395 * 396 * This check chokes if we are in an SIIT cloud. As none of BSDs 397 * support IPv4-less kernel compilation, we cannot support SIIT 398 * environment at all. So, it makes more sense for us to reject any 399 * malicious packets for non-SIIT environment, than try to do a 400 * partical support for SIIT environment. 401 */ 402 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 403 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 404 ip6stat.ip6s_badscope++; 405 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 406 goto bad; 407 } 408 #if 0 409 /* 410 * Reject packets with IPv4 compatible addresses (auto tunnel). 411 * 412 * The code forbids auto tunnel relay case in RFC1933 (the check is 413 * stronger than RFC1933). We may want to re-enable it if mech-xx 414 * is revised to forbid relaying case. 415 */ 416 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 417 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 418 ip6stat.ip6s_badscope++; 419 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 420 goto bad; 421 } 422 #endif 423 424 /* drop packets if interface ID portion is already filled */ 425 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 426 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 427 ip6->ip6_src.s6_addr16[1]) { 428 ip6stat.ip6s_badscope++; 429 goto bad; 430 } 431 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 432 ip6->ip6_dst.s6_addr16[1]) { 433 ip6stat.ip6s_badscope++; 434 goto bad; 435 } 436 } 437 438 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 439 ip6->ip6_src.s6_addr16[1] 440 = htons(m->m_pkthdr.rcvif->if_index); 441 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 442 ip6->ip6_dst.s6_addr16[1] 443 = htons(m->m_pkthdr.rcvif->if_index); 444 445 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ 446 /* 447 * We use rt->rt_ifp to determine if the address is ours or not. 448 * If rt_ifp is lo0, the address is ours. 449 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 450 * so any address under fe80::%lo0/64 will be mistakenly considered 451 * local. The special case is supplied to handle the case properly 452 * by actually looking at interface addresses 453 * (using in6ifa_ifpwithaddr). 454 */ 455 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 456 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 457 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 458 icmp6_error(m, ICMP6_DST_UNREACH, 459 ICMP6_DST_UNREACH_ADDR, 0); 460 /* m is already freed */ 461 return; 462 } 463 464 ours = 1; 465 deliverifp = m->m_pkthdr.rcvif; 466 goto hbhcheck; 467 } 468 #endif 469 470 /* 471 * Multicast check 472 */ 473 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 474 struct in6_multi *in6m = 0; 475 476 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 477 /* 478 * See if we belong to the destination multicast group on the 479 * arrival interface. 480 */ 481 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 482 if (in6m) 483 ours = 1; 484 else if (!ip6_mrouter) { 485 ip6stat.ip6s_notmember++; 486 ip6stat.ip6s_cantforward++; 487 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 488 goto bad; 489 } 490 deliverifp = m->m_pkthdr.rcvif; 491 goto hbhcheck; 492 } 493 494 /* 495 * Unicast check 496 */ 497 switch (ip6_ours_check_algorithm) { 498 default: 499 /* 500 * XXX: I intentionally broke our indentation rule here, 501 * since this switch-case is just for measurement and 502 * therefore should soon be removed. 503 */ 504 if (ip6_forward_rt.ro_rt != NULL && 505 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 506 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 507 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 508 ip6stat.ip6s_forward_cachehit++; 509 else { 510 struct sockaddr_in6 *dst6; 511 512 if (ip6_forward_rt.ro_rt) { 513 /* route is down or destination is different */ 514 ip6stat.ip6s_forward_cachemiss++; 515 RTFREE(ip6_forward_rt.ro_rt); 516 ip6_forward_rt.ro_rt = 0; 517 } 518 519 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 520 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 521 dst6->sin6_len = sizeof(struct sockaddr_in6); 522 dst6->sin6_family = AF_INET6; 523 dst6->sin6_addr = ip6->ip6_dst; 524 #ifdef SCOPEDROUTING 525 ip6_forward_rt.ro_dst.sin6_scope_id = 526 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst); 527 #endif 528 529 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 530 } 531 532 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 533 534 /* 535 * Accept the packet if the forwarding interface to the destination 536 * according to the routing table is the loopback interface, 537 * unless the associated route has a gateway. 538 * Note that this approach causes to accept a packet if there is a 539 * route to the loopback interface for the destination of the packet. 540 * But we think it's even useful in some situations, e.g. when using 541 * a special daemon which wants to intercept the packet. 542 * 543 * XXX: some OSes automatically make a cloned route for the destination 544 * of an outgoing packet. If the outgoing interface of the packet 545 * is a loopback one, the kernel would consider the packet to be 546 * accepted, even if we have no such address assinged on the interface. 547 * We check the cloned flag of the route entry to reject such cases, 548 * assuming that route entries for our own addresses are not made by 549 * cloning (it should be true because in6_addloop explicitly installs 550 * the host route). However, we might have to do an explicit check 551 * while it would be less efficient. Or, should we rather install a 552 * reject route for such a case? 553 */ 554 if (ip6_forward_rt.ro_rt && 555 (ip6_forward_rt.ro_rt->rt_flags & 556 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 557 #ifdef RTF_WASCLONED 558 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 559 #endif 560 #ifdef RTF_CLONED 561 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 562 #endif 563 #if 0 564 /* 565 * The check below is redundant since the comparison of 566 * the destination and the key of the rtentry has 567 * already done through looking up the routing table. 568 */ 569 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 570 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 571 #endif 572 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 573 struct in6_ifaddr *ia6 = 574 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 575 576 /* 577 * record address information into m_aux. 578 */ 579 (void)ip6_setdstifaddr(m, ia6); 580 581 /* 582 * packets to a tentative, duplicated, or somehow invalid 583 * address must not be accepted. 584 */ 585 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 586 /* this address is ready */ 587 ours = 1; 588 deliverifp = ia6->ia_ifp; /* correct? */ 589 /* Count the packet in the ip address stats */ 590 ia6->ia_ifa.if_ipackets++; 591 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 592 goto hbhcheck; 593 } else { 594 /* address is not ready, so discard the packet. */ 595 nd6log((LOG_INFO, 596 "ip6_input: packet to an unready address %s->%s\n", 597 ip6_sprintf(&ip6->ip6_src), 598 ip6_sprintf(&ip6->ip6_dst))); 599 600 goto bad; 601 } 602 } 603 } /* XXX indentation (see above) */ 604 605 /* 606 * FAITH(Firewall Aided Internet Translator) 607 */ 608 if (ip6_keepfaith) { 609 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 610 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 611 /* XXX do we need more sanity checks? */ 612 ours = 1; 613 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 614 goto hbhcheck; 615 } 616 } 617 618 /* 619 * Now there is no reason to process the packet if it's not our own 620 * and we're not a router. 621 */ 622 if (!ip6_forwarding) { 623 ip6stat.ip6s_cantforward++; 624 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 625 goto bad; 626 } 627 628 hbhcheck: 629 /* 630 * record address information into m_aux, if we don't have one yet. 631 * note that we are unable to record it, if the address is not listed 632 * as our interface address (e.g. multicast addresses, addresses 633 * within FAITH prefixes and such). 634 */ 635 if (deliverifp && !ip6_getdstifaddr(m)) { 636 struct in6_ifaddr *ia6; 637 638 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 639 if (ia6) { 640 if (!ip6_setdstifaddr(m, ia6)) { 641 /* 642 * XXX maybe we should drop the packet here, 643 * as we could not provide enough information 644 * to the upper layers. 645 */ 646 } 647 } 648 } 649 650 /* 651 * Process Hop-by-Hop options header if it's contained. 652 * m may be modified in ip6_hopopts_input(). 653 * If a JumboPayload option is included, plen will also be modified. 654 */ 655 plen = (u_int32_t)ntohs(ip6->ip6_plen); 656 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 657 struct ip6_hbh *hbh; 658 659 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 660 #if 0 /*touches NULL pointer*/ 661 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 662 #endif 663 return; /* m have already been freed */ 664 } 665 666 /* adjust pointer */ 667 ip6 = mtod(m, struct ip6_hdr *); 668 669 /* 670 * if the payload length field is 0 and the next header field 671 * indicates Hop-by-Hop Options header, then a Jumbo Payload 672 * option MUST be included. 673 */ 674 if (ip6->ip6_plen == 0 && plen == 0) { 675 /* 676 * Note that if a valid jumbo payload option is 677 * contained, ip6_hoptops_input() must set a valid 678 * (non-zero) payload length to the variable plen. 679 */ 680 ip6stat.ip6s_badoptions++; 681 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 682 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 683 icmp6_error(m, ICMP6_PARAM_PROB, 684 ICMP6_PARAMPROB_HEADER, 685 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 686 return; 687 } 688 #ifndef PULLDOWN_TEST 689 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 690 hbh = (struct ip6_hbh *)(ip6 + 1); 691 #else 692 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 693 sizeof(struct ip6_hbh)); 694 if (hbh == NULL) { 695 ip6stat.ip6s_tooshort++; 696 return; 697 } 698 #endif 699 nxt = hbh->ip6h_nxt; 700 701 /* 702 * accept the packet if a router alert option is included 703 * and we act as an IPv6 router. 704 */ 705 if (rtalert != ~0 && ip6_forwarding) 706 ours = 1; 707 } else 708 nxt = ip6->ip6_nxt; 709 710 /* 711 * Check that the amount of data in the buffers 712 * is as at least much as the IPv6 header would have us expect. 713 * Trim mbufs if longer than we expect. 714 * Drop packet if shorter than we expect. 715 */ 716 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 717 ip6stat.ip6s_tooshort++; 718 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 719 goto bad; 720 } 721 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 722 if (m->m_len == m->m_pkthdr.len) { 723 m->m_len = sizeof(struct ip6_hdr) + plen; 724 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 725 } else 726 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 727 } 728 729 /* 730 * Forward if desirable. 731 */ 732 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 733 /* 734 * If we are acting as a multicast router, all 735 * incoming multicast packets are passed to the 736 * kernel-level multicast forwarding function. 737 * The packet is returned (relatively) intact; if 738 * ip6_mforward() returns a non-zero value, the packet 739 * must be discarded, else it may be accepted below. 740 */ 741 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 742 ip6stat.ip6s_cantforward++; 743 m_freem(m); 744 return; 745 } 746 if (!ours) { 747 m_freem(m); 748 return; 749 } 750 } else if (!ours) { 751 ip6_forward(m, 0); 752 return; 753 } 754 755 ip6 = mtod(m, struct ip6_hdr *); 756 757 /* 758 * Malicious party may be able to use IPv4 mapped addr to confuse 759 * tcp/udp stack and bypass security checks (act as if it was from 760 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 761 * 762 * For SIIT end node behavior, you may want to disable the check. 763 * However, you will become vulnerable to attacks using IPv4 mapped 764 * source. 765 */ 766 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 767 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 768 ip6stat.ip6s_badscope++; 769 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 770 goto bad; 771 } 772 773 /* 774 * Tell launch routine the next header 775 */ 776 ip6stat.ip6s_delivered++; 777 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 778 nest = 0; 779 780 while (nxt != IPPROTO_DONE) { 781 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 782 ip6stat.ip6s_toomanyhdr++; 783 goto bad; 784 } 785 786 /* 787 * protection against faulty packet - there should be 788 * more sanity checks in header chain processing. 789 */ 790 if (m->m_pkthdr.len < off) { 791 ip6stat.ip6s_tooshort++; 792 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 793 goto bad; 794 } 795 796 #if 0 797 /* 798 * do we need to do it for every header? yeah, other 799 * functions can play with it (like re-allocate and copy). 800 */ 801 mhist = ip6_addaux(m); 802 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 803 hist = mtod(mhist, caddr_t) + mhist->m_len; 804 bcopy(&nxt, hist, sizeof(nxt)); 805 mhist->m_len += sizeof(nxt); 806 } else { 807 ip6stat.ip6s_toomanyhdr++; 808 goto bad; 809 } 810 #endif 811 812 #ifdef IPSEC 813 /* 814 * enforce IPsec policy checking if we are seeing last header. 815 * note that we do not visit this with protocols with pcb layer 816 * code - like udp/tcp/raw ip. 817 */ 818 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 819 ipsec6_in_reject(m, NULL)) { 820 ipsec6stat.in_polvio++; 821 goto bad; 822 } 823 #endif 824 825 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 826 } 827 return; 828 bad: 829 m_freem(m); 830 } 831 832 /* 833 * set/grab in6_ifaddr correspond to IPv6 destination address. 834 * XXX backward compatibility wrapper 835 */ 836 static struct ip6aux * 837 ip6_setdstifaddr(m, ia6) 838 struct mbuf *m; 839 struct in6_ifaddr *ia6; 840 { 841 struct ip6aux *n; 842 843 n = ip6_addaux(m); 844 if (n) 845 n->ip6a_dstia6 = ia6; 846 return n; /* NULL if failed to set */ 847 } 848 849 struct in6_ifaddr * 850 ip6_getdstifaddr(m) 851 struct mbuf *m; 852 { 853 struct ip6aux *n; 854 855 n = ip6_findaux(m); 856 if (n) 857 return n->ip6a_dstia6; 858 else 859 return NULL; 860 } 861 862 /* 863 * Hop-by-Hop options header processing. If a valid jumbo payload option is 864 * included, the real payload length will be stored in plenp. 865 */ 866 static int 867 ip6_hopopts_input(plenp, rtalertp, mp, offp) 868 u_int32_t *plenp; 869 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 870 struct mbuf **mp; 871 int *offp; 872 { 873 struct mbuf *m = *mp; 874 int off = *offp, hbhlen; 875 struct ip6_hbh *hbh; 876 u_int8_t *opt; 877 878 /* validation of the length of the header */ 879 #ifndef PULLDOWN_TEST 880 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 881 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 882 hbhlen = (hbh->ip6h_len + 1) << 3; 883 884 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 885 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 886 #else 887 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 888 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 889 if (hbh == NULL) { 890 ip6stat.ip6s_tooshort++; 891 return -1; 892 } 893 hbhlen = (hbh->ip6h_len + 1) << 3; 894 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 895 hbhlen); 896 if (hbh == NULL) { 897 ip6stat.ip6s_tooshort++; 898 return -1; 899 } 900 #endif 901 off += hbhlen; 902 hbhlen -= sizeof(struct ip6_hbh); 903 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 904 905 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 906 hbhlen, rtalertp, plenp) < 0) 907 return(-1); 908 909 *offp = off; 910 *mp = m; 911 return(0); 912 } 913 914 /* 915 * Search header for all Hop-by-hop options and process each option. 916 * This function is separate from ip6_hopopts_input() in order to 917 * handle a case where the sending node itself process its hop-by-hop 918 * options header. In such a case, the function is called from ip6_output(). 919 * 920 * The function assumes that hbh header is located right after the IPv6 header 921 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 922 * opthead + hbhlen is located in continuous memory region. 923 */ 924 int 925 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 926 struct mbuf *m; 927 u_int8_t *opthead; 928 int hbhlen; 929 u_int32_t *rtalertp; 930 u_int32_t *plenp; 931 { 932 struct ip6_hdr *ip6; 933 int optlen = 0; 934 u_int8_t *opt = opthead; 935 u_int16_t rtalert_val; 936 u_int32_t jumboplen; 937 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 938 939 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 940 switch (*opt) { 941 case IP6OPT_PAD1: 942 optlen = 1; 943 break; 944 case IP6OPT_PADN: 945 if (hbhlen < IP6OPT_MINLEN) { 946 ip6stat.ip6s_toosmall++; 947 goto bad; 948 } 949 optlen = *(opt + 1) + 2; 950 break; 951 case IP6OPT_RTALERT: 952 /* XXX may need check for alignment */ 953 if (hbhlen < IP6OPT_RTALERT_LEN) { 954 ip6stat.ip6s_toosmall++; 955 goto bad; 956 } 957 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 958 /* XXX stat */ 959 icmp6_error(m, ICMP6_PARAM_PROB, 960 ICMP6_PARAMPROB_HEADER, 961 erroff + opt + 1 - opthead); 962 return(-1); 963 } 964 optlen = IP6OPT_RTALERT_LEN; 965 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 966 *rtalertp = ntohs(rtalert_val); 967 break; 968 case IP6OPT_JUMBO: 969 /* XXX may need check for alignment */ 970 if (hbhlen < IP6OPT_JUMBO_LEN) { 971 ip6stat.ip6s_toosmall++; 972 goto bad; 973 } 974 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 975 /* XXX stat */ 976 icmp6_error(m, ICMP6_PARAM_PROB, 977 ICMP6_PARAMPROB_HEADER, 978 erroff + opt + 1 - opthead); 979 return(-1); 980 } 981 optlen = IP6OPT_JUMBO_LEN; 982 983 /* 984 * IPv6 packets that have non 0 payload length 985 * must not contain a jumbo payload option. 986 */ 987 ip6 = mtod(m, struct ip6_hdr *); 988 if (ip6->ip6_plen) { 989 ip6stat.ip6s_badoptions++; 990 icmp6_error(m, ICMP6_PARAM_PROB, 991 ICMP6_PARAMPROB_HEADER, 992 erroff + opt - opthead); 993 return(-1); 994 } 995 996 /* 997 * We may see jumbolen in unaligned location, so 998 * we'd need to perform bcopy(). 999 */ 1000 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1001 jumboplen = (u_int32_t)htonl(jumboplen); 1002 1003 #if 1 1004 /* 1005 * if there are multiple jumbo payload options, 1006 * *plenp will be non-zero and the packet will be 1007 * rejected. 1008 * the behavior may need some debate in ipngwg - 1009 * multiple options does not make sense, however, 1010 * there's no explicit mention in specification. 1011 */ 1012 if (*plenp != 0) { 1013 ip6stat.ip6s_badoptions++; 1014 icmp6_error(m, ICMP6_PARAM_PROB, 1015 ICMP6_PARAMPROB_HEADER, 1016 erroff + opt + 2 - opthead); 1017 return(-1); 1018 } 1019 #endif 1020 1021 /* 1022 * jumbo payload length must be larger than 65535. 1023 */ 1024 if (jumboplen <= IPV6_MAXPACKET) { 1025 ip6stat.ip6s_badoptions++; 1026 icmp6_error(m, ICMP6_PARAM_PROB, 1027 ICMP6_PARAMPROB_HEADER, 1028 erroff + opt + 2 - opthead); 1029 return(-1); 1030 } 1031 *plenp = jumboplen; 1032 1033 break; 1034 default: /* unknown option */ 1035 if (hbhlen < IP6OPT_MINLEN) { 1036 ip6stat.ip6s_toosmall++; 1037 goto bad; 1038 } 1039 optlen = ip6_unknown_opt(opt, m, 1040 erroff + opt - opthead); 1041 if (optlen == -1) 1042 return(-1); 1043 optlen += 2; 1044 break; 1045 } 1046 } 1047 1048 return(0); 1049 1050 bad: 1051 m_freem(m); 1052 return(-1); 1053 } 1054 1055 /* 1056 * Unknown option processing. 1057 * The third argument `off' is the offset from the IPv6 header to the option, 1058 * which is necessary if the IPv6 header the and option header and IPv6 header 1059 * is not continuous in order to return an ICMPv6 error. 1060 */ 1061 int 1062 ip6_unknown_opt(optp, m, off) 1063 u_int8_t *optp; 1064 struct mbuf *m; 1065 int off; 1066 { 1067 struct ip6_hdr *ip6; 1068 1069 switch (IP6OPT_TYPE(*optp)) { 1070 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1071 return((int)*(optp + 1)); 1072 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1073 m_freem(m); 1074 return(-1); 1075 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1076 ip6stat.ip6s_badoptions++; 1077 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1078 return(-1); 1079 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1080 ip6stat.ip6s_badoptions++; 1081 ip6 = mtod(m, struct ip6_hdr *); 1082 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1083 (m->m_flags & (M_BCAST|M_MCAST))) 1084 m_freem(m); 1085 else 1086 icmp6_error(m, ICMP6_PARAM_PROB, 1087 ICMP6_PARAMPROB_OPTION, off); 1088 return(-1); 1089 } 1090 1091 m_freem(m); /* XXX: NOTREACHED */ 1092 return(-1); 1093 } 1094 1095 /* 1096 * Create the "control" list for this pcb. 1097 * The function will not modify mbuf chain at all. 1098 * 1099 * with KAME mbuf chain restriction: 1100 * The routine will be called from upper layer handlers like tcp6_input(). 1101 * Thus the routine assumes that the caller (tcp6_input) have already 1102 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1103 * very first mbuf on the mbuf chain. 1104 */ 1105 void 1106 ip6_savecontrol(in6p, mp, ip6, m) 1107 struct inpcb *in6p; 1108 struct mbuf **mp; 1109 struct ip6_hdr *ip6; 1110 struct mbuf *m; 1111 { 1112 #if __FreeBSD_version >= 500000 1113 struct thread *td = curthread; /* XXX */ 1114 #else 1115 struct proc *td = curproc; /* XXX */ 1116 #endif 1117 int privileged = 0; 1118 int rthdr_exist = 0; 1119 1120 1121 if (td && !suser(td)) 1122 privileged++; 1123 1124 #ifdef SO_TIMESTAMP 1125 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1126 struct timeval tv; 1127 1128 microtime(&tv); 1129 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1130 SCM_TIMESTAMP, SOL_SOCKET); 1131 if (*mp) { 1132 mp = &(*mp)->m_next; 1133 } 1134 } 1135 #endif 1136 1137 /* RFC 2292 sec. 5 */ 1138 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1139 struct in6_pktinfo pi6; 1140 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1141 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1142 pi6.ipi6_addr.s6_addr16[1] = 0; 1143 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1144 ? m->m_pkthdr.rcvif->if_index 1145 : 0; 1146 *mp = sbcreatecontrol((caddr_t) &pi6, 1147 sizeof(struct in6_pktinfo), IPV6_PKTINFO, 1148 IPPROTO_IPV6); 1149 if (*mp) 1150 mp = &(*mp)->m_next; 1151 } 1152 1153 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1154 int hlim = ip6->ip6_hlim & 0xff; 1155 *mp = sbcreatecontrol((caddr_t) &hlim, 1156 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); 1157 if (*mp) 1158 mp = &(*mp)->m_next; 1159 } 1160 1161 /* 1162 * IPV6_HOPOPTS socket option. We require super-user privilege 1163 * for the option, but it might be too strict, since there might 1164 * be some hop-by-hop options which can be returned to normal user. 1165 * See RFC 2292 section 6. 1166 */ 1167 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) { 1168 /* 1169 * Check if a hop-by-hop options header is contatined in the 1170 * received packet, and if so, store the options as ancillary 1171 * data. Note that a hop-by-hop options header must be 1172 * just after the IPv6 header, which fact is assured through 1173 * the IPv6 input processing. 1174 */ 1175 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1176 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1177 struct ip6_hbh *hbh; 1178 int hbhlen = 0; 1179 #ifdef PULLDOWN_TEST 1180 struct mbuf *ext; 1181 #endif 1182 1183 #ifndef PULLDOWN_TEST 1184 hbh = (struct ip6_hbh *)(ip6 + 1); 1185 hbhlen = (hbh->ip6h_len + 1) << 3; 1186 #else 1187 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1188 ip6->ip6_nxt); 1189 if (ext == NULL) { 1190 ip6stat.ip6s_tooshort++; 1191 return; 1192 } 1193 hbh = mtod(ext, struct ip6_hbh *); 1194 hbhlen = (hbh->ip6h_len + 1) << 3; 1195 if (hbhlen != ext->m_len) { 1196 m_freem(ext); 1197 ip6stat.ip6s_tooshort++; 1198 return; 1199 } 1200 #endif 1201 1202 /* 1203 * XXX: We copy whole the header even if a jumbo 1204 * payload option is included, which option is to 1205 * be removed before returning in the RFC 2292. 1206 * Note: this constraint is removed in 2292bis. 1207 */ 1208 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1209 IPV6_HOPOPTS, IPPROTO_IPV6); 1210 if (*mp) 1211 mp = &(*mp)->m_next; 1212 #ifdef PULLDOWN_TEST 1213 m_freem(ext); 1214 #endif 1215 } 1216 } 1217 1218 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1219 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1220 int proto, off, nxt; 1221 1222 /* 1223 * go through the header chain to see if a routing header is 1224 * contained in the packet. We need this information to store 1225 * destination options headers (if any) properly. 1226 * XXX: performance issue. We should record this info when 1227 * processing extension headers in incoming routine. 1228 * (todo) use m_aux? 1229 */ 1230 proto = IPPROTO_IPV6; 1231 off = 0; 1232 nxt = -1; 1233 while (1) { 1234 int newoff; 1235 1236 newoff = ip6_nexthdr(m, off, proto, &nxt); 1237 if (newoff < 0) 1238 break; 1239 if (newoff < off) /* invalid, check for safety */ 1240 break; 1241 if ((proto = nxt) == IPPROTO_ROUTING) { 1242 rthdr_exist = 1; 1243 break; 1244 } 1245 off = newoff; 1246 } 1247 } 1248 1249 if ((in6p->in6p_flags & 1250 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1251 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1252 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1253 1254 /* 1255 * Search for destination options headers or routing 1256 * header(s) through the header chain, and stores each 1257 * header as ancillary data. 1258 * Note that the order of the headers remains in 1259 * the chain of ancillary data. 1260 */ 1261 while (1) { /* is explicit loop prevention necessary? */ 1262 struct ip6_ext *ip6e = NULL; 1263 int elen; 1264 #ifdef PULLDOWN_TEST 1265 struct mbuf *ext = NULL; 1266 #endif 1267 1268 /* 1269 * if it is not an extension header, don't try to 1270 * pull it from the chain. 1271 */ 1272 switch (nxt) { 1273 case IPPROTO_DSTOPTS: 1274 case IPPROTO_ROUTING: 1275 case IPPROTO_HOPOPTS: 1276 case IPPROTO_AH: /* is it possible? */ 1277 break; 1278 default: 1279 goto loopend; 1280 } 1281 1282 #ifndef PULLDOWN_TEST 1283 if (off + sizeof(*ip6e) > m->m_len) 1284 goto loopend; 1285 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1286 if (nxt == IPPROTO_AH) 1287 elen = (ip6e->ip6e_len + 2) << 2; 1288 else 1289 elen = (ip6e->ip6e_len + 1) << 3; 1290 if (off + elen > m->m_len) 1291 goto loopend; 1292 #else 1293 ext = ip6_pullexthdr(m, off, nxt); 1294 if (ext == NULL) { 1295 ip6stat.ip6s_tooshort++; 1296 return; 1297 } 1298 ip6e = mtod(ext, struct ip6_ext *); 1299 if (nxt == IPPROTO_AH) 1300 elen = (ip6e->ip6e_len + 2) << 2; 1301 else 1302 elen = (ip6e->ip6e_len + 1) << 3; 1303 if (elen != ext->m_len) { 1304 m_freem(ext); 1305 ip6stat.ip6s_tooshort++; 1306 return; 1307 } 1308 #endif 1309 1310 switch (nxt) { 1311 case IPPROTO_DSTOPTS: 1312 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1313 break; 1314 1315 /* 1316 * We also require super-user privilege for 1317 * the option. 1318 * See the comments on IN6_HOPOPTS. 1319 */ 1320 if (!privileged) 1321 break; 1322 1323 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1324 IPV6_DSTOPTS, 1325 IPPROTO_IPV6); 1326 if (*mp) 1327 mp = &(*mp)->m_next; 1328 break; 1329 case IPPROTO_ROUTING: 1330 if (!in6p->in6p_flags & IN6P_RTHDR) 1331 break; 1332 1333 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1334 IPV6_RTHDR, 1335 IPPROTO_IPV6); 1336 if (*mp) 1337 mp = &(*mp)->m_next; 1338 break; 1339 case IPPROTO_HOPOPTS: 1340 case IPPROTO_AH: /* is it possible? */ 1341 break; 1342 1343 default: 1344 /* 1345 * other cases have been filtered in the above. 1346 * none will visit this case. here we supply 1347 * the code just in case (nxt overwritten or 1348 * other cases). 1349 */ 1350 #ifdef PULLDOWN_TEST 1351 m_freem(ext); 1352 #endif 1353 goto loopend; 1354 1355 } 1356 1357 /* proceed with the next header. */ 1358 off += elen; 1359 nxt = ip6e->ip6e_nxt; 1360 ip6e = NULL; 1361 #ifdef PULLDOWN_TEST 1362 m_freem(ext); 1363 ext = NULL; 1364 #endif 1365 } 1366 loopend: 1367 ; 1368 } 1369 1370 } 1371 1372 #ifdef PULLDOWN_TEST 1373 /* 1374 * pull single extension header from mbuf chain. returns single mbuf that 1375 * contains the result, or NULL on error. 1376 */ 1377 static struct mbuf * 1378 ip6_pullexthdr(m, off, nxt) 1379 struct mbuf *m; 1380 size_t off; 1381 int nxt; 1382 { 1383 struct ip6_ext ip6e; 1384 size_t elen; 1385 struct mbuf *n; 1386 1387 #ifdef DIAGNOSTIC 1388 switch (nxt) { 1389 case IPPROTO_DSTOPTS: 1390 case IPPROTO_ROUTING: 1391 case IPPROTO_HOPOPTS: 1392 case IPPROTO_AH: /* is it possible? */ 1393 break; 1394 default: 1395 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1396 } 1397 #endif 1398 1399 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1400 if (nxt == IPPROTO_AH) 1401 elen = (ip6e.ip6e_len + 2) << 2; 1402 else 1403 elen = (ip6e.ip6e_len + 1) << 3; 1404 1405 MGET(n, M_DONTWAIT, MT_DATA); 1406 if (n && elen >= MLEN) { 1407 MCLGET(n, M_DONTWAIT); 1408 if ((n->m_flags & M_EXT) == 0) { 1409 m_free(n); 1410 n = NULL; 1411 } 1412 } 1413 if (!n) 1414 return NULL; 1415 1416 n->m_len = 0; 1417 if (elen >= M_TRAILINGSPACE(n)) { 1418 m_free(n); 1419 return NULL; 1420 } 1421 1422 m_copydata(m, off, elen, mtod(n, caddr_t)); 1423 n->m_len = elen; 1424 return n; 1425 } 1426 #endif 1427 1428 /* 1429 * Get pointer to the previous header followed by the header 1430 * currently processed. 1431 * XXX: This function supposes that 1432 * M includes all headers, 1433 * the next header field and the header length field of each header 1434 * are valid, and 1435 * the sum of each header length equals to OFF. 1436 * Because of these assumptions, this function must be called very 1437 * carefully. Moreover, it will not be used in the near future when 1438 * we develop `neater' mechanism to process extension headers. 1439 */ 1440 char * 1441 ip6_get_prevhdr(m, off) 1442 struct mbuf *m; 1443 int off; 1444 { 1445 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1446 1447 if (off == sizeof(struct ip6_hdr)) 1448 return(&ip6->ip6_nxt); 1449 else { 1450 int len, nxt; 1451 struct ip6_ext *ip6e = NULL; 1452 1453 nxt = ip6->ip6_nxt; 1454 len = sizeof(struct ip6_hdr); 1455 while (len < off) { 1456 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1457 1458 switch (nxt) { 1459 case IPPROTO_FRAGMENT: 1460 len += sizeof(struct ip6_frag); 1461 break; 1462 case IPPROTO_AH: 1463 len += (ip6e->ip6e_len + 2) << 2; 1464 break; 1465 default: 1466 len += (ip6e->ip6e_len + 1) << 3; 1467 break; 1468 } 1469 nxt = ip6e->ip6e_nxt; 1470 } 1471 if (ip6e) 1472 return(&ip6e->ip6e_nxt); 1473 else 1474 return NULL; 1475 } 1476 } 1477 1478 /* 1479 * get next header offset. m will be retained. 1480 */ 1481 int 1482 ip6_nexthdr(m, off, proto, nxtp) 1483 struct mbuf *m; 1484 int off; 1485 int proto; 1486 int *nxtp; 1487 { 1488 struct ip6_hdr ip6; 1489 struct ip6_ext ip6e; 1490 struct ip6_frag fh; 1491 1492 /* just in case */ 1493 if (m == NULL) 1494 panic("ip6_nexthdr: m == NULL"); 1495 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1496 return -1; 1497 1498 switch (proto) { 1499 case IPPROTO_IPV6: 1500 if (m->m_pkthdr.len < off + sizeof(ip6)) 1501 return -1; 1502 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1503 if (nxtp) 1504 *nxtp = ip6.ip6_nxt; 1505 off += sizeof(ip6); 1506 return off; 1507 1508 case IPPROTO_FRAGMENT: 1509 /* 1510 * terminate parsing if it is not the first fragment, 1511 * it does not make sense to parse through it. 1512 */ 1513 if (m->m_pkthdr.len < off + sizeof(fh)) 1514 return -1; 1515 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1516 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) 1517 return -1; 1518 if (nxtp) 1519 *nxtp = fh.ip6f_nxt; 1520 off += sizeof(struct ip6_frag); 1521 return off; 1522 1523 case IPPROTO_AH: 1524 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1525 return -1; 1526 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1527 if (nxtp) 1528 *nxtp = ip6e.ip6e_nxt; 1529 off += (ip6e.ip6e_len + 2) << 2; 1530 return off; 1531 1532 case IPPROTO_HOPOPTS: 1533 case IPPROTO_ROUTING: 1534 case IPPROTO_DSTOPTS: 1535 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1536 return -1; 1537 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1538 if (nxtp) 1539 *nxtp = ip6e.ip6e_nxt; 1540 off += (ip6e.ip6e_len + 1) << 3; 1541 return off; 1542 1543 case IPPROTO_NONE: 1544 case IPPROTO_ESP: 1545 case IPPROTO_IPCOMP: 1546 /* give up */ 1547 return -1; 1548 1549 default: 1550 return -1; 1551 } 1552 1553 return -1; 1554 } 1555 1556 /* 1557 * get offset for the last header in the chain. m will be kept untainted. 1558 */ 1559 int 1560 ip6_lasthdr(m, off, proto, nxtp) 1561 struct mbuf *m; 1562 int off; 1563 int proto; 1564 int *nxtp; 1565 { 1566 int newoff; 1567 int nxt; 1568 1569 if (!nxtp) { 1570 nxt = -1; 1571 nxtp = &nxt; 1572 } 1573 while (1) { 1574 newoff = ip6_nexthdr(m, off, proto, nxtp); 1575 if (newoff < 0) 1576 return off; 1577 else if (newoff < off) 1578 return -1; /* invalid */ 1579 else if (newoff == off) 1580 return newoff; 1581 1582 off = newoff; 1583 proto = *nxtp; 1584 } 1585 } 1586 1587 struct ip6aux * 1588 ip6_addaux(m) 1589 struct mbuf *m; 1590 { 1591 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1592 if (!tag) { 1593 tag = m_tag_get(PACKET_TAG_IPV6_INPUT, 1594 sizeof (struct ip6aux), 1595 M_NOWAIT); 1596 if (tag) 1597 m_tag_prepend(m, tag); 1598 } 1599 if (tag) 1600 bzero(tag+1, sizeof (struct ip6aux)); 1601 return tag ? (struct ip6aux*)(tag+1) : NULL; 1602 } 1603 1604 struct ip6aux * 1605 ip6_findaux(m) 1606 struct mbuf *m; 1607 { 1608 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1609 return tag ? (struct ip6aux*)(tag+1) : NULL; 1610 } 1611 1612 void 1613 ip6_delaux(m) 1614 struct mbuf *m; 1615 { 1616 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1617 if (tag) 1618 m_tag_delete(m, tag); 1619 } 1620 1621 /* 1622 * System control for IP6 1623 */ 1624 1625 u_char inet6ctlerrmap[PRC_NCMDS] = { 1626 0, 0, 0, 0, 1627 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1628 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1629 EMSGSIZE, EHOSTUNREACH, 0, 0, 1630 0, 0, 0, 0, 1631 ENOPROTOOPT 1632 }; 1633