1 /* $FreeBSD$ */ 2 /* $KAME: ip6_input.c,v 1.95 2000/07/02 07:49:37 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 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/mbuf.h> 77 #include <sys/domain.h> 78 #include <sys/protosw.h> 79 #include <sys/socket.h> 80 #include <sys/socketvar.h> 81 #include <sys/errno.h> 82 #include <sys/time.h> 83 #include <sys/kernel.h> 84 #include <sys/syslog.h> 85 86 #include <net/if.h> 87 #include <net/if_types.h> 88 #include <net/if_dl.h> 89 #include <net/route.h> 90 #include <net/netisr.h> 91 #include <net/intrq.h> 92 #ifdef PFIL_HOOKS 93 #include <net/pfil.h> 94 #endif 95 96 #include <netinet/in.h> 97 #include <netinet/in_systm.h> 98 #ifdef INET 99 #include <netinet/ip.h> 100 #include <netinet/ip_icmp.h> 101 #endif /*INET*/ 102 #include <netinet/ip6.h> 103 #include <netinet6/in6_var.h> 104 #include <netinet6/ip6_var.h> 105 #include <netinet/in_pcb.h> 106 #include <netinet/icmp6.h> 107 #include <netinet6/in6_ifattach.h> 108 #include <netinet6/nd6.h> 109 #include <netinet6/in6_prefix.h> 110 111 #include <netinet6/ip6_fw.h> 112 113 #include <netinet6/ip6protosw.h> 114 115 #include "faith.h" 116 #include "gif.h" 117 118 #include <net/net_osdep.h> 119 120 extern struct domain inet6domain; 121 extern struct ip6protosw inet6sw[]; 122 123 u_char ip6_protox[IPPROTO_MAX]; 124 static int ip6qmaxlen = IFQ_MAXLEN; 125 struct in6_ifaddr *in6_ifaddr; 126 127 int ip6_forward_srcrt; /* XXX */ 128 int ip6_sourcecheck; /* XXX */ 129 int ip6_sourcecheck_interval; /* XXX */ 130 const int int6intrq_present = 1; 131 132 /* firewall hooks */ 133 ip6_fw_chk_t *ip6_fw_chk_ptr; 134 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 135 int ip6_fw_enable = 1; 136 137 struct ip6stat ip6stat; 138 139 static void ip6_init2 __P((void *)); 140 141 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 142 #ifdef PULLDOWN_TEST 143 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 144 #endif 145 146 /* 147 * IP6 initialization: fill in IP6 protocol switch table. 148 * All protocols not implemented in kernel go to raw IP6 protocol handler. 149 */ 150 void 151 ip6_init() 152 { 153 register struct ip6protosw *pr; 154 register int i; 155 struct timeval tv; 156 157 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 158 if (pr == 0) 159 panic("ip6_init"); 160 for (i = 0; i < IPPROTO_MAX; i++) 161 ip6_protox[i] = pr - inet6sw; 162 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 163 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 164 if (pr->pr_domain->dom_family == PF_INET6 && 165 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 166 ip6_protox[pr->pr_protocol] = pr - inet6sw; 167 ip6intrq.ifq_maxlen = ip6qmaxlen; 168 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", MTX_DEF); 169 register_netisr(NETISR_IPV6, ip6intr); 170 nd6_init(); 171 frag6_init(); 172 /* 173 * in many cases, random() here does NOT return random number 174 * as initialization during bootstrap time occur in fixed order. 175 */ 176 microtime(&tv); 177 ip6_flow_seq = random() ^ tv.tv_usec; 178 } 179 180 static void 181 ip6_init2(dummy) 182 void *dummy; 183 { 184 185 /* 186 * to route local address of p2p link to loopback, 187 * assign loopback address first. 188 */ 189 in6_ifattach(&loif[0], NULL); 190 191 /* nd6_timer_init */ 192 timeout(nd6_timer, (caddr_t)0, hz); 193 /* router renumbering prefix list maintenance */ 194 timeout(in6_rr_timer, (caddr_t)0, hz); 195 } 196 197 /* cheat */ 198 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 199 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 200 201 /* 202 * IP6 input interrupt handling. Just pass the packet to ip6_input. 203 */ 204 void 205 ip6intr() 206 { 207 int s; 208 struct mbuf *m; 209 210 for (;;) { 211 s = splimp(); 212 IF_DEQUEUE(&ip6intrq, m); 213 splx(s); 214 if (m == 0) 215 return; 216 ip6_input(m); 217 } 218 } 219 220 extern struct route_in6 ip6_forward_rt; 221 222 void 223 ip6_input(m) 224 struct mbuf *m; 225 { 226 struct ip6_hdr *ip6; 227 int off = sizeof(struct ip6_hdr), nest; 228 u_int32_t plen; 229 u_int32_t rtalert = ~0; 230 int nxt, ours = 0; 231 struct ifnet *deliverifp = NULL; 232 #ifdef PFIL_HOOKS 233 struct packet_filter_hook *pfh; 234 struct mbuf *m0; 235 int rv; 236 #endif /* PFIL_HOOKS */ 237 238 #ifdef IPSEC 239 /* 240 * should the inner packet be considered authentic? 241 * see comment in ah4_input(). 242 */ 243 if (m) { 244 m->m_flags &= ~M_AUTHIPHDR; 245 m->m_flags &= ~M_AUTHIPDGM; 246 } 247 #endif 248 249 /* 250 * mbuf statistics by kazu 251 */ 252 if (m->m_flags & M_EXT) { 253 if (m->m_next) 254 ip6stat.ip6s_mext2m++; 255 else 256 ip6stat.ip6s_mext1++; 257 } else { 258 if (m->m_next) { 259 if (m->m_flags & M_LOOP) { 260 ip6stat.ip6s_m2m[loif[0].if_index]++; /*XXX*/ 261 } else if (m->m_pkthdr.rcvif->if_index <= 31) 262 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 263 else 264 ip6stat.ip6s_m2m[0]++; 265 } else 266 ip6stat.ip6s_m1++; 267 } 268 269 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 270 ip6stat.ip6s_total++; 271 272 #ifndef PULLDOWN_TEST 273 /* 274 * L2 bridge code and some other code can return mbuf chain 275 * that does not conform to KAME requirement. too bad. 276 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 277 */ 278 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 279 struct mbuf *n; 280 281 MGETHDR(n, M_DONTWAIT, MT_HEADER); 282 if (n) 283 M_COPY_PKTHDR(n, m); 284 if (n && m->m_pkthdr.len > MHLEN) { 285 MCLGET(n, M_DONTWAIT); 286 if ((n->m_flags & M_EXT) == 0) { 287 m_freem(n); 288 n = NULL; 289 } 290 } 291 if (!n) { 292 m_freem(m); 293 return; /*ENOBUFS*/ 294 } 295 296 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t)); 297 n->m_len = m->m_pkthdr.len; 298 m_freem(m); 299 m = n; 300 } 301 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); 302 #endif 303 304 if (m->m_len < sizeof(struct ip6_hdr)) { 305 struct ifnet *inifp; 306 inifp = m->m_pkthdr.rcvif; 307 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) { 308 ip6stat.ip6s_toosmall++; 309 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 310 return; 311 } 312 } 313 314 ip6 = mtod(m, struct ip6_hdr *); 315 316 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 317 ip6stat.ip6s_badvers++; 318 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 319 goto bad; 320 } 321 322 #ifdef PFIL_HOOKS 323 /* 324 * Run through list of hooks for input packets. If there are any 325 * filters which require that additional packets in the flow are 326 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 327 * Note that filters must _never_ set this flag, as another filter 328 * in the list may have previously cleared it. 329 */ 330 m0 = m; 331 pfh = pfil_hook_get(PFIL_IN, &inet6sw[ip6_protox[IPPROTO_IPV6]].pr_pfh); 332 for (; pfh; pfh = pfh->pfil_link.tqe_next) 333 if (pfh->pfil_func) { 334 rv = pfh->pfil_func(ip6, sizeof(*ip6), 335 m->m_pkthdr.rcvif, 0, &m0); 336 if (rv) 337 return; 338 m = m0; 339 if (m == NULL) 340 return; 341 ip6 = mtod(m, struct ip6_hdr *); 342 } 343 #endif /* PFIL_HOOKS */ 344 345 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 346 347 /* 348 * Check with the firewall... 349 */ 350 if (ip6_fw_enable && ip6_fw_chk_ptr) { 351 u_short port = 0; 352 /* If ipfw says divert, we have to just drop packet */ 353 /* use port as a dummy argument */ 354 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 355 m_freem(m); 356 m = NULL; 357 } 358 if (!m) 359 return; 360 } 361 362 /* 363 * Scope check 364 */ 365 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 366 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 367 ip6stat.ip6s_badscope++; 368 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 369 goto bad; 370 } 371 372 /* 373 * Don't check IPv4 mapped address here. SIIT assumes that 374 * routers would forward IPv6 native packets with IPv4 mapped 375 * address normally. 376 */ 377 #if 0 378 /* 379 * Reject packets with IPv4 compatible addresses (auto tunnel). 380 * 381 * The code forbids auto tunnel relay case in RFC1933 (the check is 382 * stronger than RFC1933). We may want to re-enable it if mech-xx 383 * is revised to forbid relaying case. 384 */ 385 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 386 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 387 ip6stat.ip6s_badscope++; 388 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 389 goto bad; 390 } 391 #endif 392 if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 393 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) { 394 if (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) { 395 struct in6_ifaddr *ia6; 396 397 if ((ia6 = in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, 398 &ip6->ip6_dst)) != NULL) { 399 ia6->ia_ifa.if_ipackets++; 400 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 401 } else { 402 /* 403 * The packet is looped back, but we do not 404 * have the destination address for some 405 * reason. 406 * XXX: should we return an icmp6 error? 407 */ 408 goto bad; 409 } 410 ours = 1; 411 deliverifp = m->m_pkthdr.rcvif; 412 goto hbhcheck; 413 } else { 414 ip6stat.ip6s_badscope++; 415 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 416 goto bad; 417 } 418 } 419 420 #ifndef FAKE_LOOPBACK_IF 421 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) 422 #else 423 if (1) 424 #endif 425 { 426 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 427 ip6->ip6_src.s6_addr16[1] 428 = htons(m->m_pkthdr.rcvif->if_index); 429 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 430 ip6->ip6_dst.s6_addr16[1] 431 = htons(m->m_pkthdr.rcvif->if_index); 432 } 433 434 /* 435 * XXX we need this since we do not have "goto ours" hack route 436 * for some of our ifaddrs on loopback interface. 437 * we should correct it by changing in6_ifattach to install 438 * "goto ours" hack route. 439 */ 440 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0) { 441 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 442 struct in6_ifaddr *ia6; 443 #ifndef FAKE_LOOPBACK_IF 444 int deliverifid; 445 446 /* 447 * Get the "real" delivered interface, which should be 448 * embedded in the second 16 bits of the destination 449 * address. We can probably trust the value, but we 450 * add validation for the value just for safety. 451 */ 452 deliverifid = ntohs(ip6->ip6_dst.s6_addr16[1]); 453 if (deliverifid > 0 && deliverifid <= if_index) { 454 deliverifp = ifindex2ifnet[deliverifid]; 455 456 /* 457 * XXX: fake the rcvif to the real interface. 458 * Since m_pkthdr.rcvif should be lo0 (or a 459 * variant), it would confuse scope handling 460 * code later. 461 */ 462 m->m_pkthdr.rcvif = deliverifp; 463 } 464 else { 465 /* 466 * Last resort; just use rcvif. 467 * XXX: the packet would be discarded by the 468 * succeeding check. 469 */ 470 deliverifp = m->m_pkthdr.rcvif; 471 } 472 #else 473 deliverifp = m->m_pkthdr.rcvif; 474 #endif 475 if ((ia6 = in6ifa_ifpwithaddr(deliverifp, 476 &ip6->ip6_dst)) != NULL) { 477 ia6->ia_ifa.if_ipackets++; 478 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 479 } else { 480 /* 481 * We do not have the link-local address 482 * specified as the destination. 483 * XXX: should we return an icmp6 error? 484 */ 485 goto bad; 486 } 487 ours = 1; 488 goto hbhcheck; 489 } 490 } 491 492 /* 493 * Multicast check 494 */ 495 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 496 struct in6_multi *in6m = 0; 497 498 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 499 /* 500 * See if we belong to the destination multicast group on the 501 * arrival interface. 502 */ 503 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 504 if (in6m) 505 ours = 1; 506 else if (!ip6_mrouter) { 507 ip6stat.ip6s_notmember++; 508 ip6stat.ip6s_cantforward++; 509 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 510 goto bad; 511 } 512 deliverifp = m->m_pkthdr.rcvif; 513 goto hbhcheck; 514 } 515 516 /* 517 * Unicast check 518 */ 519 if (ip6_forward_rt.ro_rt != NULL && 520 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 521 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 522 &ip6_forward_rt.ro_dst.sin6_addr)) 523 ip6stat.ip6s_forward_cachehit++; 524 else { 525 if (ip6_forward_rt.ro_rt) { 526 /* route is down or destination is different */ 527 ip6stat.ip6s_forward_cachemiss++; 528 RTFREE(ip6_forward_rt.ro_rt); 529 ip6_forward_rt.ro_rt = 0; 530 } 531 532 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 533 ip6_forward_rt.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 534 ip6_forward_rt.ro_dst.sin6_family = AF_INET6; 535 ip6_forward_rt.ro_dst.sin6_addr = ip6->ip6_dst; 536 #ifdef SCOPEDROUTING 537 ip6_forward_rt.ro_dst.sin6_scope_id = 538 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst); 539 #endif 540 541 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 542 } 543 544 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 545 546 /* 547 * Accept the packet if the forwarding interface to the destination 548 * according to the routing table is the loopback interface, 549 * unless the associated route has a gateway. 550 * Note that this approach causes to accept a packet if there is a 551 * route to the loopback interface for the destination of the packet. 552 * But we think it's even useful in some situations, e.g. when using 553 * a special daemon which wants to intercept the packet. 554 */ 555 if (ip6_forward_rt.ro_rt && 556 (ip6_forward_rt.ro_rt->rt_flags & 557 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 558 #if 0 559 /* 560 * The check below is redundant since the comparison of 561 * the destination and the key of the rtentry has 562 * already done through looking up the routing table. 563 */ 564 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 565 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) && 566 #endif 567 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 568 struct in6_ifaddr *ia6 = 569 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 570 if (ia6->ia6_flags & IN6_IFF_ANYCAST) 571 m->m_flags |= M_ANYCAST6; 572 /* 573 * packets to a tentative, duplicated, or somehow invalid 574 * address must not be accepted. 575 */ 576 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 577 /* this address is ready */ 578 ours = 1; 579 deliverifp = ia6->ia_ifp; /* correct? */ 580 581 /* Count the packet in the ip address stats */ 582 ia6->ia_ifa.if_ipackets++; 583 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 584 585 goto hbhcheck; 586 } else { 587 /* address is not ready, so discard the packet. */ 588 log(LOG_INFO, 589 "ip6_input: packet to an unready address %s->%s", 590 ip6_sprintf(&ip6->ip6_src), 591 ip6_sprintf(&ip6->ip6_dst)); 592 593 goto bad; 594 } 595 } 596 597 /* 598 * FAITH(Firewall Aided Internet Translator) 599 */ 600 #if defined(NFAITH) && 0 < NFAITH 601 if (ip6_keepfaith) { 602 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 603 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 604 /* XXX do we need more sanity checks? */ 605 ours = 1; 606 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /*faith*/ 607 goto hbhcheck; 608 } 609 } 610 #endif 611 612 /* 613 * Now there is no reason to process the packet if it's not our own 614 * and we're not a router. 615 */ 616 if (!ip6_forwarding) { 617 ip6stat.ip6s_cantforward++; 618 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 619 goto bad; 620 } 621 622 hbhcheck: 623 /* 624 * Process Hop-by-Hop options header if it's contained. 625 * m may be modified in ip6_hopopts_input(). 626 * If a JumboPayload option is included, plen will also be modified. 627 */ 628 plen = (u_int32_t)ntohs(ip6->ip6_plen); 629 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 630 struct ip6_hbh *hbh; 631 632 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 633 #if 0 /*touches NULL pointer*/ 634 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 635 #endif 636 return; /* m have already been freed */ 637 } 638 639 /* adjust pointer */ 640 ip6 = mtod(m, struct ip6_hdr *); 641 642 /* 643 * if the payload length field is 0 and the next header field 644 * indicates Hop-by-Hop Options header, then a Jumbo Payload 645 * option MUST be included. 646 */ 647 if (ip6->ip6_plen == 0 && plen == 0) { 648 /* 649 * Note that if a valid jumbo payload option is 650 * contained, ip6_hoptops_input() must set a valid 651 * (non-zero) payload length to the variable plen. 652 */ 653 ip6stat.ip6s_badoptions++; 654 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 655 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 656 icmp6_error(m, ICMP6_PARAM_PROB, 657 ICMP6_PARAMPROB_HEADER, 658 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 659 return; 660 } 661 #ifndef PULLDOWN_TEST 662 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 663 hbh = (struct ip6_hbh *)(ip6 + 1); 664 #else 665 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 666 sizeof(struct ip6_hbh)); 667 if (hbh == NULL) { 668 ip6stat.ip6s_tooshort++; 669 return; 670 } 671 #endif 672 nxt = hbh->ip6h_nxt; 673 674 /* 675 * accept the packet if a router alert option is included 676 * and we act as an IPv6 router. 677 */ 678 if (rtalert != ~0 && ip6_forwarding) 679 ours = 1; 680 } else 681 nxt = ip6->ip6_nxt; 682 683 /* 684 * Check that the amount of data in the buffers 685 * is as at least much as the IPv6 header would have us expect. 686 * Trim mbufs if longer than we expect. 687 * Drop packet if shorter than we expect. 688 */ 689 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 690 ip6stat.ip6s_tooshort++; 691 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 692 goto bad; 693 } 694 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 695 if (m->m_len == m->m_pkthdr.len) { 696 m->m_len = sizeof(struct ip6_hdr) + plen; 697 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 698 } else 699 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 700 } 701 702 /* 703 * Forward if desirable. 704 */ 705 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 706 /* 707 * If we are acting as a multicast router, all 708 * incoming multicast packets are passed to the 709 * kernel-level multicast forwarding function. 710 * The packet is returned (relatively) intact; if 711 * ip6_mforward() returns a non-zero value, the packet 712 * must be discarded, else it may be accepted below. 713 */ 714 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 715 ip6stat.ip6s_cantforward++; 716 m_freem(m); 717 return; 718 } 719 if (!ours) { 720 m_freem(m); 721 return; 722 } 723 } else if (!ours) { 724 ip6_forward(m, 0); 725 return; 726 } 727 728 ip6 = mtod(m, struct ip6_hdr *); 729 730 /* 731 * Malicious party may be able to use IPv4 mapped addr to confuse 732 * tcp/udp stack and bypass security checks (act as if it was from 733 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 734 * 735 * For SIIT end node behavior, you may want to disable the check. 736 * However, you will become vulnerable to attacks using IPv4 mapped 737 * source. 738 */ 739 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 740 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 741 ip6stat.ip6s_badscope++; 742 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 743 goto bad; 744 } 745 746 /* 747 * Tell launch routine the next header 748 */ 749 ip6stat.ip6s_delivered++; 750 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 751 nest = 0; 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 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 769 } 770 return; 771 bad: 772 m_freem(m); 773 } 774 775 /* 776 * Hop-by-Hop options header processing. If a valid jumbo payload option is 777 * included, the real payload length will be stored in plenp. 778 */ 779 static int 780 ip6_hopopts_input(plenp, rtalertp, mp, offp) 781 u_int32_t *plenp; 782 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 783 struct mbuf **mp; 784 int *offp; 785 { 786 register struct mbuf *m = *mp; 787 int off = *offp, hbhlen; 788 struct ip6_hbh *hbh; 789 u_int8_t *opt; 790 791 /* validation of the length of the header */ 792 #ifndef PULLDOWN_TEST 793 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 794 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 795 hbhlen = (hbh->ip6h_len + 1) << 3; 796 797 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 798 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 799 #else 800 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 801 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 802 if (hbh == NULL) { 803 ip6stat.ip6s_tooshort++; 804 return -1; 805 } 806 hbhlen = (hbh->ip6h_len + 1) << 3; 807 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 808 hbhlen); 809 if (hbh == NULL) { 810 ip6stat.ip6s_tooshort++; 811 return -1; 812 } 813 #endif 814 off += hbhlen; 815 hbhlen -= sizeof(struct ip6_hbh); 816 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 817 818 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 819 hbhlen, rtalertp, plenp) < 0) 820 return(-1); 821 822 *offp = off; 823 *mp = m; 824 return(0); 825 } 826 827 /* 828 * Search header for all Hop-by-hop options and process each option. 829 * This function is separate from ip6_hopopts_input() in order to 830 * handle a case where the sending node itself process its hop-by-hop 831 * options header. In such a case, the function is called from ip6_output(). 832 */ 833 int 834 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 835 struct mbuf *m; 836 u_int8_t *opthead; 837 int hbhlen; 838 u_int32_t *rtalertp; 839 u_int32_t *plenp; 840 { 841 struct ip6_hdr *ip6; 842 int optlen = 0; 843 u_int8_t *opt = opthead; 844 u_int16_t rtalert_val; 845 u_int32_t jumboplen; 846 847 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 848 switch(*opt) { 849 case IP6OPT_PAD1: 850 optlen = 1; 851 break; 852 case IP6OPT_PADN: 853 if (hbhlen < IP6OPT_MINLEN) { 854 ip6stat.ip6s_toosmall++; 855 goto bad; 856 } 857 optlen = *(opt + 1) + 2; 858 break; 859 case IP6OPT_RTALERT: 860 /* XXX may need check for alignment */ 861 if (hbhlen < IP6OPT_RTALERT_LEN) { 862 ip6stat.ip6s_toosmall++; 863 goto bad; 864 } 865 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) 866 /* XXX: should we discard the packet? */ 867 log(LOG_ERR, "length of router alert opt is inconsitent(%d)", 868 *(opt + 1)); 869 optlen = IP6OPT_RTALERT_LEN; 870 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 871 *rtalertp = ntohs(rtalert_val); 872 break; 873 case IP6OPT_JUMBO: 874 /* XXX may need check for alignment */ 875 if (hbhlen < IP6OPT_JUMBO_LEN) { 876 ip6stat.ip6s_toosmall++; 877 goto bad; 878 } 879 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) 880 /* XXX: should we discard the packet? */ 881 log(LOG_ERR, "length of jumbopayload opt " 882 "is inconsistent(%d)", 883 *(opt + 1)); 884 optlen = IP6OPT_JUMBO_LEN; 885 886 /* 887 * IPv6 packets that have non 0 payload length 888 * must not contain a jumbo paylod option. 889 */ 890 ip6 = mtod(m, struct ip6_hdr *); 891 if (ip6->ip6_plen) { 892 ip6stat.ip6s_badoptions++; 893 icmp6_error(m, ICMP6_PARAM_PROB, 894 ICMP6_PARAMPROB_HEADER, 895 sizeof(struct ip6_hdr) + 896 sizeof(struct ip6_hbh) + 897 opt - opthead); 898 return(-1); 899 } 900 901 /* 902 * We may see jumbolen in unaligned location, so 903 * we'd need to perform bcopy(). 904 */ 905 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 906 jumboplen = (u_int32_t)htonl(jumboplen); 907 908 #if 1 909 /* 910 * if there are multiple jumbo payload options, 911 * *plenp will be non-zero and the packet will be 912 * rejected. 913 * the behavior may need some debate in ipngwg - 914 * multiple options does not make sense, however, 915 * there's no explicit mention in specification. 916 */ 917 if (*plenp != 0) { 918 ip6stat.ip6s_badoptions++; 919 icmp6_error(m, ICMP6_PARAM_PROB, 920 ICMP6_PARAMPROB_HEADER, 921 sizeof(struct ip6_hdr) + 922 sizeof(struct ip6_hbh) + 923 opt + 2 - opthead); 924 return(-1); 925 } 926 #endif 927 928 /* 929 * jumbo payload length must be larger than 65535. 930 */ 931 if (jumboplen <= IPV6_MAXPACKET) { 932 ip6stat.ip6s_badoptions++; 933 icmp6_error(m, ICMP6_PARAM_PROB, 934 ICMP6_PARAMPROB_HEADER, 935 sizeof(struct ip6_hdr) + 936 sizeof(struct ip6_hbh) + 937 opt + 2 - opthead); 938 return(-1); 939 } 940 *plenp = jumboplen; 941 942 break; 943 default: /* unknown option */ 944 if (hbhlen < IP6OPT_MINLEN) { 945 ip6stat.ip6s_toosmall++; 946 goto bad; 947 } 948 if ((optlen = ip6_unknown_opt(opt, m, 949 sizeof(struct ip6_hdr) + 950 sizeof(struct ip6_hbh) + 951 opt - opthead)) == -1) 952 return(-1); 953 optlen += 2; 954 break; 955 } 956 } 957 958 return(0); 959 960 bad: 961 m_freem(m); 962 return(-1); 963 } 964 965 /* 966 * Unknown option processing. 967 * The third argument `off' is the offset from the IPv6 header to the option, 968 * which is necessary if the IPv6 header the and option header and IPv6 header 969 * is not continuous in order to return an ICMPv6 error. 970 */ 971 int 972 ip6_unknown_opt(optp, m, off) 973 u_int8_t *optp; 974 struct mbuf *m; 975 int off; 976 { 977 struct ip6_hdr *ip6; 978 979 switch(IP6OPT_TYPE(*optp)) { 980 case IP6OPT_TYPE_SKIP: /* ignore the option */ 981 return((int)*(optp + 1)); 982 case IP6OPT_TYPE_DISCARD: /* silently discard */ 983 m_freem(m); 984 return(-1); 985 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 986 ip6stat.ip6s_badoptions++; 987 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 988 return(-1); 989 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 990 ip6stat.ip6s_badoptions++; 991 ip6 = mtod(m, struct ip6_hdr *); 992 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 993 (m->m_flags & (M_BCAST|M_MCAST))) 994 m_freem(m); 995 else 996 icmp6_error(m, ICMP6_PARAM_PROB, 997 ICMP6_PARAMPROB_OPTION, off); 998 return(-1); 999 } 1000 1001 m_freem(m); /* XXX: NOTREACHED */ 1002 return(-1); 1003 } 1004 1005 /* 1006 * Create the "control" list for this pcb. 1007 * 1008 * The routine will be called from upper layer handlers like tcp6_input(). 1009 * Thus the routine assumes that the caller (tcp6_input) have already 1010 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1011 * very first mbuf on the mbuf chain. 1012 * We may want to add some infinite loop prevention or sanity checks for safety. 1013 * (This applies only when you are using KAME mbuf chain restriction, i.e. 1014 * you are using IP6_EXTHDR_CHECK() not m_pulldown()) 1015 */ 1016 void 1017 ip6_savecontrol(in6p, mp, ip6, m) 1018 register struct in6pcb *in6p; 1019 register struct mbuf **mp; 1020 register struct ip6_hdr *ip6; 1021 register struct mbuf *m; 1022 { 1023 struct proc *p = curproc; /* XXX */ 1024 int privileged; 1025 1026 privileged = 0; 1027 if (p && !suser(p)) 1028 privileged++; 1029 1030 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 1031 struct timeval tv; 1032 1033 microtime(&tv); 1034 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1035 SCM_TIMESTAMP, SOL_SOCKET); 1036 if (*mp) 1037 mp = &(*mp)->m_next; 1038 } 1039 1040 #ifdef noyet 1041 /* options were tossed above */ 1042 if (in6p->in6p_flags & IN6P_RECVOPTS) 1043 /* broken */ 1044 /* ip6_srcroute doesn't do what we want here, need to fix */ 1045 if (in6p->in6p_flags & IPV6P_RECVRETOPTS) 1046 /* broken */ 1047 #endif 1048 1049 /* RFC 2292 sec. 5 */ 1050 if (in6p->in6p_flags & IN6P_PKTINFO) { 1051 struct in6_pktinfo pi6; 1052 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1053 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1054 pi6.ipi6_addr.s6_addr16[1] = 0; 1055 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1056 ? m->m_pkthdr.rcvif->if_index 1057 : 0; 1058 *mp = sbcreatecontrol((caddr_t) &pi6, 1059 sizeof(struct in6_pktinfo), IPV6_PKTINFO, 1060 IPPROTO_IPV6); 1061 if (*mp) 1062 mp = &(*mp)->m_next; 1063 } 1064 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1065 int hlim = ip6->ip6_hlim & 0xff; 1066 *mp = sbcreatecontrol((caddr_t) &hlim, 1067 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); 1068 if (*mp) 1069 mp = &(*mp)->m_next; 1070 } 1071 /* IN6P_NEXTHOP - for outgoing packet only */ 1072 1073 /* 1074 * IPV6_HOPOPTS socket option. We require super-user privilege 1075 * for the option, but it might be too strict, since there might 1076 * be some hop-by-hop options which can be returned to normal user. 1077 * See RFC 2292 section 6. 1078 */ 1079 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1080 /* 1081 * Check if a hop-by-hop options header is contatined in the 1082 * received packet, and if so, store the options as ancillary 1083 * data. Note that a hop-by-hop options header must be 1084 * just after the IPv6 header, which fact is assured through 1085 * the IPv6 input processing. 1086 */ 1087 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1088 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1089 struct ip6_hbh *hbh; 1090 int hbhlen; 1091 1092 #ifndef PULLDOWN_TEST 1093 hbh = (struct ip6_hbh *)(ip6 + 1); 1094 hbhlen = (hbh->ip6h_len + 1) << 3; 1095 #else 1096 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 1097 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 1098 if (hbh == NULL) { 1099 ip6stat.ip6s_tooshort++; 1100 return; 1101 } 1102 hbhlen = (hbh->ip6h_len + 1) << 3; 1103 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 1104 sizeof(struct ip6_hdr), hbhlen); 1105 if (hbh == NULL) { 1106 ip6stat.ip6s_tooshort++; 1107 return; 1108 } 1109 #endif 1110 1111 /* 1112 * XXX: We copy whole the header even if a jumbo 1113 * payload option is included, which option is to 1114 * be removed before returning in the RFC 2292. 1115 * But it's too painful operation... 1116 */ 1117 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1118 IPV6_HOPOPTS, IPPROTO_IPV6); 1119 if (*mp) 1120 mp = &(*mp)->m_next; 1121 } 1122 } 1123 1124 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1125 if (in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDR)) { 1126 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1127 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);; 1128 1129 /* 1130 * Search for destination options headers or routing 1131 * header(s) through the header chain, and stores each 1132 * header as ancillary data. 1133 * Note that the order of the headers remains in 1134 * the chain of ancillary data. 1135 */ 1136 while(1) { /* is explicit loop prevention necessary? */ 1137 struct ip6_ext *ip6e; 1138 int elen; 1139 1140 #ifndef PULLDOWN_TEST 1141 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1142 if (nxt == IPPROTO_AH) 1143 elen = (ip6e->ip6e_len + 2) << 2; 1144 else 1145 elen = (ip6e->ip6e_len + 1) << 3; 1146 #else 1147 IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off, 1148 sizeof(struct ip6_ext)); 1149 if (ip6e == NULL) { 1150 ip6stat.ip6s_tooshort++; 1151 return; 1152 } 1153 if (nxt == IPPROTO_AH) 1154 elen = (ip6e->ip6e_len + 2) << 2; 1155 else 1156 elen = (ip6e->ip6e_len + 1) << 3; 1157 IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off, elen); 1158 if (ip6e == NULL) { 1159 ip6stat.ip6s_tooshort++; 1160 return; 1161 } 1162 #endif 1163 1164 switch(nxt) { 1165 case IPPROTO_DSTOPTS: 1166 if (!in6p->in6p_flags & IN6P_DSTOPTS) 1167 break; 1168 1169 /* 1170 * We also require super-user privilege for 1171 * the option. 1172 * See the comments on IN6_HOPOPTS. 1173 */ 1174 if (!privileged) 1175 break; 1176 1177 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1178 IPV6_DSTOPTS, 1179 IPPROTO_IPV6); 1180 if (*mp) 1181 mp = &(*mp)->m_next; 1182 break; 1183 1184 case IPPROTO_ROUTING: 1185 if (!in6p->in6p_flags & IN6P_RTHDR) 1186 break; 1187 1188 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1189 IPV6_RTHDR, 1190 IPPROTO_IPV6); 1191 if (*mp) 1192 mp = &(*mp)->m_next; 1193 break; 1194 1195 case IPPROTO_UDP: 1196 case IPPROTO_TCP: 1197 case IPPROTO_ICMPV6: 1198 default: 1199 /* 1200 * stop search if we encounter an upper 1201 * layer protocol headers. 1202 */ 1203 goto loopend; 1204 1205 case IPPROTO_HOPOPTS: 1206 case IPPROTO_AH: /* is it possible? */ 1207 break; 1208 } 1209 1210 /* proceed with the next header. */ 1211 off += elen; 1212 nxt = ip6e->ip6e_nxt; 1213 } 1214 loopend: 1215 } 1216 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1217 /* to be done */ 1218 } 1219 if ((in6p->in6p_flags & IN6P_DSTOPTS) && privileged) { 1220 /* to be done */ 1221 } 1222 /* IN6P_RTHDR - to be done */ 1223 1224 } 1225 1226 /* 1227 * Get pointer to the previous header followed by the header 1228 * currently processed. 1229 * XXX: This function supposes that 1230 * M includes all headers, 1231 * the next header field and the header length field of each header 1232 * are valid, and 1233 * the sum of each header length equals to OFF. 1234 * Because of these assumptions, this function must be called very 1235 * carefully. Moreover, it will not be used in the near future when 1236 * we develop `neater' mechanism to process extension headers. 1237 */ 1238 char * 1239 ip6_get_prevhdr(m, off) 1240 struct mbuf *m; 1241 int off; 1242 { 1243 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1244 1245 if (off == sizeof(struct ip6_hdr)) 1246 return(&ip6->ip6_nxt); 1247 else { 1248 int len, nxt; 1249 struct ip6_ext *ip6e = NULL; 1250 1251 nxt = ip6->ip6_nxt; 1252 len = sizeof(struct ip6_hdr); 1253 while (len < off) { 1254 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1255 1256 switch(nxt) { 1257 case IPPROTO_FRAGMENT: 1258 len += sizeof(struct ip6_frag); 1259 break; 1260 case IPPROTO_AH: 1261 len += (ip6e->ip6e_len + 2) << 2; 1262 break; 1263 default: 1264 len += (ip6e->ip6e_len + 1) << 3; 1265 break; 1266 } 1267 nxt = ip6e->ip6e_nxt; 1268 } 1269 if (ip6e) 1270 return(&ip6e->ip6e_nxt); 1271 else 1272 return NULL; 1273 } 1274 } 1275 1276 /* 1277 * get next header offset. m will be retained. 1278 */ 1279 int 1280 ip6_nexthdr(m, off, proto, nxtp) 1281 struct mbuf *m; 1282 int off; 1283 int proto; 1284 int *nxtp; 1285 { 1286 struct ip6_hdr ip6; 1287 struct ip6_ext ip6e; 1288 struct ip6_frag fh; 1289 1290 /* just in case */ 1291 if (m == NULL) 1292 panic("ip6_nexthdr: m == NULL"); 1293 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1294 return -1; 1295 1296 switch (proto) { 1297 case IPPROTO_IPV6: 1298 if (m->m_pkthdr.len < off + sizeof(ip6)) 1299 return -1; 1300 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1301 if (nxtp) 1302 *nxtp = ip6.ip6_nxt; 1303 off += sizeof(ip6); 1304 return off; 1305 1306 case IPPROTO_FRAGMENT: 1307 /* 1308 * terminate parsing if it is not the first fragment, 1309 * it does not make sense to parse through it. 1310 */ 1311 if (m->m_pkthdr.len < off + sizeof(fh)) 1312 return -1; 1313 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1314 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) 1315 return -1; 1316 if (nxtp) 1317 *nxtp = fh.ip6f_nxt; 1318 off += sizeof(struct ip6_frag); 1319 return off; 1320 1321 case IPPROTO_AH: 1322 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1323 return -1; 1324 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1325 if (nxtp) 1326 *nxtp = ip6e.ip6e_nxt; 1327 off += (ip6e.ip6e_len + 2) << 2; 1328 return off; 1329 1330 case IPPROTO_HOPOPTS: 1331 case IPPROTO_ROUTING: 1332 case IPPROTO_DSTOPTS: 1333 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1334 return -1; 1335 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1336 if (nxtp) 1337 *nxtp = ip6e.ip6e_nxt; 1338 off += (ip6e.ip6e_len + 1) << 3; 1339 return off; 1340 1341 case IPPROTO_NONE: 1342 case IPPROTO_ESP: 1343 case IPPROTO_IPCOMP: 1344 /* give up */ 1345 return -1; 1346 1347 default: 1348 return -1; 1349 } 1350 1351 return -1; 1352 } 1353 1354 /* 1355 * get offset for the last header in the chain. m will be kept untainted. 1356 */ 1357 int 1358 ip6_lasthdr(m, off, proto, nxtp) 1359 struct mbuf *m; 1360 int off; 1361 int proto; 1362 int *nxtp; 1363 { 1364 int newoff; 1365 int nxt; 1366 1367 if (!nxtp) { 1368 nxt = -1; 1369 nxtp = &nxt; 1370 } 1371 while (1) { 1372 newoff = ip6_nexthdr(m, off, proto, nxtp); 1373 if (newoff < 0) 1374 return off; 1375 else if (newoff < off) 1376 return -1; /* invalid */ 1377 else if (newoff == off) 1378 return newoff; 1379 1380 off = newoff; 1381 proto = *nxtp; 1382 } 1383 } 1384 1385 /* 1386 * System control for IP6 1387 */ 1388 1389 u_char inet6ctlerrmap[PRC_NCMDS] = { 1390 0, 0, 0, 0, 1391 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1392 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1393 EMSGSIZE, EHOSTUNREACH, 0, 0, 1394 0, 0, 0, 0, 1395 ENOPROTOOPT 1396 }; 1397