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 && m->m_pkthdr.len > MHLEN) { 283 MCLGET(n, M_DONTWAIT); 284 if ((n->m_flags & M_EXT) == 0) { 285 m_freem(n); 286 n = NULL; 287 } 288 } 289 if (!n) 290 return; /*ENOBUFS*/ 291 292 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t)); 293 n->m_pkthdr = m->m_pkthdr; 294 n->m_len = m->m_pkthdr.len; 295 n->m_pkthdr.aux = m->m_pkthdr.aux; 296 m->m_pkthdr.aux = (struct mbuf *)NULL; 297 m_freem(m); 298 m = n; 299 } 300 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); 301 #endif 302 303 if (m->m_len < sizeof(struct ip6_hdr)) { 304 struct ifnet *inifp; 305 inifp = m->m_pkthdr.rcvif; 306 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) { 307 ip6stat.ip6s_toosmall++; 308 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 309 return; 310 } 311 } 312 313 ip6 = mtod(m, struct ip6_hdr *); 314 315 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 316 ip6stat.ip6s_badvers++; 317 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 318 goto bad; 319 } 320 321 #ifdef PFIL_HOOKS 322 /* 323 * Run through list of hooks for input packets. If there are any 324 * filters which require that additional packets in the flow are 325 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 326 * Note that filters must _never_ set this flag, as another filter 327 * in the list may have previously cleared it. 328 */ 329 m0 = m; 330 pfh = pfil_hook_get(PFIL_IN, &inet6sw[ip6_protox[IPPROTO_IPV6]].pr_pfh); 331 for (; pfh; pfh = pfh->pfil_link.tqe_next) 332 if (pfh->pfil_func) { 333 rv = pfh->pfil_func(ip6, sizeof(*ip6), 334 m->m_pkthdr.rcvif, 0, &m0); 335 if (rv) 336 return; 337 m = m0; 338 if (m == NULL) 339 return; 340 ip6 = mtod(m, struct ip6_hdr *); 341 } 342 #endif /* PFIL_HOOKS */ 343 344 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 345 346 /* 347 * Check with the firewall... 348 */ 349 if (ip6_fw_enable && ip6_fw_chk_ptr) { 350 u_short port = 0; 351 /* If ipfw says divert, we have to just drop packet */ 352 /* use port as a dummy argument */ 353 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 354 m_freem(m); 355 m = NULL; 356 } 357 if (!m) 358 return; 359 } 360 361 /* 362 * Scope check 363 */ 364 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 365 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 366 ip6stat.ip6s_badscope++; 367 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 368 goto bad; 369 } 370 371 /* 372 * Don't check IPv4 mapped address here. SIIT assumes that 373 * routers would forward IPv6 native packets with IPv4 mapped 374 * address normally. 375 */ 376 #if 0 377 /* 378 * Reject packets with IPv4 compatible addresses (auto tunnel). 379 * 380 * The code forbids auto tunnel relay case in RFC1933 (the check is 381 * stronger than RFC1933). We may want to re-enable it if mech-xx 382 * is revised to forbid relaying case. 383 */ 384 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 385 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 386 ip6stat.ip6s_badscope++; 387 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 388 goto bad; 389 } 390 #endif 391 if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 392 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) { 393 if (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) { 394 ours = 1; 395 deliverifp = m->m_pkthdr.rcvif; 396 goto hbhcheck; 397 } else { 398 ip6stat.ip6s_badscope++; 399 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 400 goto bad; 401 } 402 } 403 404 #ifndef FAKE_LOOPBACK_IF 405 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) 406 #else 407 if (1) 408 #endif 409 { 410 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 411 ip6->ip6_src.s6_addr16[1] 412 = htons(m->m_pkthdr.rcvif->if_index); 413 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 414 ip6->ip6_dst.s6_addr16[1] 415 = htons(m->m_pkthdr.rcvif->if_index); 416 } 417 418 /* 419 * XXX we need this since we do not have "goto ours" hack route 420 * for some of our ifaddrs on loopback interface. 421 * we should correct it by changing in6_ifattach to install 422 * "goto ours" hack route. 423 */ 424 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0) { 425 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 426 ours = 1; 427 deliverifp = m->m_pkthdr.rcvif; 428 goto hbhcheck; 429 } 430 } 431 432 /* 433 * Multicast check 434 */ 435 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 436 struct in6_multi *in6m = 0; 437 438 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 439 /* 440 * See if we belong to the destination multicast group on the 441 * arrival interface. 442 */ 443 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 444 if (in6m) 445 ours = 1; 446 else if (!ip6_mrouter) { 447 ip6stat.ip6s_notmember++; 448 ip6stat.ip6s_cantforward++; 449 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 450 goto bad; 451 } 452 deliverifp = m->m_pkthdr.rcvif; 453 goto hbhcheck; 454 } 455 456 /* 457 * Unicast check 458 */ 459 if (ip6_forward_rt.ro_rt != NULL && 460 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 461 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 462 &ip6_forward_rt.ro_dst.sin6_addr)) 463 ip6stat.ip6s_forward_cachehit++; 464 else { 465 if (ip6_forward_rt.ro_rt) { 466 /* route is down or destination is different */ 467 ip6stat.ip6s_forward_cachemiss++; 468 RTFREE(ip6_forward_rt.ro_rt); 469 ip6_forward_rt.ro_rt = 0; 470 } 471 472 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 473 ip6_forward_rt.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 474 ip6_forward_rt.ro_dst.sin6_family = AF_INET6; 475 ip6_forward_rt.ro_dst.sin6_addr = ip6->ip6_dst; 476 #ifdef SCOPEDROUTING 477 ip6_forward_rt.ro_dst.sin6_scope_id = 478 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst); 479 #endif 480 481 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 482 } 483 484 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 485 486 /* 487 * Accept the packet if the forwarding interface to the destination 488 * according to the routing table is the loopback interface, 489 * unless the associated route has a gateway. 490 * Note that this approach causes to accept a packet if there is a 491 * route to the loopback interface for the destination of the packet. 492 * But we think it's even useful in some situations, e.g. when using 493 * a special daemon which wants to intercept the packet. 494 */ 495 if (ip6_forward_rt.ro_rt && 496 (ip6_forward_rt.ro_rt->rt_flags & 497 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 498 #if 0 499 /* 500 * The check below is redundant since the comparison of 501 * the destination and the key of the rtentry has 502 * already done through looking up the routing table. 503 */ 504 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 505 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) && 506 #endif 507 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 508 struct in6_ifaddr *ia6 = 509 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 510 if (ia6->ia6_flags & IN6_IFF_ANYCAST) 511 m->m_flags |= M_ANYCAST6; 512 /* 513 * packets to a tentative, duplicated, or somehow invalid 514 * address must not be accepted. 515 */ 516 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 517 /* this address is ready */ 518 ours = 1; 519 deliverifp = ia6->ia_ifp; /* correct? */ 520 521 /* Count the packet in the ip address stats */ 522 ia6->ia_ifa.if_ipackets++; 523 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 524 525 goto hbhcheck; 526 } else { 527 /* address is not ready, so discard the packet. */ 528 log(LOG_INFO, 529 "ip6_input: packet to an unready address %s->%s", 530 ip6_sprintf(&ip6->ip6_src), 531 ip6_sprintf(&ip6->ip6_dst)); 532 533 goto bad; 534 } 535 } 536 537 /* 538 * FAITH(Firewall Aided Internet Translator) 539 */ 540 #if defined(NFAITH) && 0 < NFAITH 541 if (ip6_keepfaith) { 542 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 543 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 544 /* XXX do we need more sanity checks? */ 545 ours = 1; 546 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /*faith*/ 547 goto hbhcheck; 548 } 549 } 550 #endif 551 552 /* 553 * Now there is no reason to process the packet if it's not our own 554 * and we're not a router. 555 */ 556 if (!ip6_forwarding) { 557 ip6stat.ip6s_cantforward++; 558 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 559 goto bad; 560 } 561 562 hbhcheck: 563 /* 564 * Process Hop-by-Hop options header if it's contained. 565 * m may be modified in ip6_hopopts_input(). 566 * If a JumboPayload option is included, plen will also be modified. 567 */ 568 plen = (u_int32_t)ntohs(ip6->ip6_plen); 569 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 570 struct ip6_hbh *hbh; 571 572 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 573 #if 0 /*touches NULL pointer*/ 574 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 575 #endif 576 return; /* m have already been freed */ 577 } 578 579 /* adjust pointer */ 580 ip6 = mtod(m, struct ip6_hdr *); 581 582 /* 583 * if the payload length field is 0 and the next header field 584 * indicates Hop-by-Hop Options header, then a Jumbo Payload 585 * option MUST be included. 586 */ 587 if (ip6->ip6_plen == 0 && plen == 0) { 588 /* 589 * Note that if a valid jumbo payload option is 590 * contained, ip6_hoptops_input() must set a valid 591 * (non-zero) payload length to the variable plen. 592 */ 593 ip6stat.ip6s_badoptions++; 594 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 595 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 596 icmp6_error(m, ICMP6_PARAM_PROB, 597 ICMP6_PARAMPROB_HEADER, 598 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 599 return; 600 } 601 #ifndef PULLDOWN_TEST 602 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 603 hbh = (struct ip6_hbh *)(ip6 + 1); 604 #else 605 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 606 sizeof(struct ip6_hbh)); 607 if (hbh == NULL) { 608 ip6stat.ip6s_tooshort++; 609 return; 610 } 611 #endif 612 nxt = hbh->ip6h_nxt; 613 614 /* 615 * accept the packet if a router alert option is included 616 * and we act as an IPv6 router. 617 */ 618 if (rtalert != ~0 && ip6_forwarding) 619 ours = 1; 620 } else 621 nxt = ip6->ip6_nxt; 622 623 /* 624 * Check that the amount of data in the buffers 625 * is as at least much as the IPv6 header would have us expect. 626 * Trim mbufs if longer than we expect. 627 * Drop packet if shorter than we expect. 628 */ 629 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 630 ip6stat.ip6s_tooshort++; 631 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 632 goto bad; 633 } 634 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 635 if (m->m_len == m->m_pkthdr.len) { 636 m->m_len = sizeof(struct ip6_hdr) + plen; 637 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 638 } else 639 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 640 } 641 642 /* 643 * Forward if desirable. 644 */ 645 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 646 /* 647 * If we are acting as a multicast router, all 648 * incoming multicast packets are passed to the 649 * kernel-level multicast forwarding function. 650 * The packet is returned (relatively) intact; if 651 * ip6_mforward() returns a non-zero value, the packet 652 * must be discarded, else it may be accepted below. 653 */ 654 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 655 ip6stat.ip6s_cantforward++; 656 m_freem(m); 657 return; 658 } 659 if (!ours) { 660 m_freem(m); 661 return; 662 } 663 } else if (!ours) { 664 ip6_forward(m, 0); 665 return; 666 } 667 668 ip6 = mtod(m, struct ip6_hdr *); 669 670 /* 671 * Malicious party may be able to use IPv4 mapped addr to confuse 672 * tcp/udp stack and bypass security checks (act as if it was from 673 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 674 * 675 * For SIIT end node behavior, you may want to disable the check. 676 * However, you will become vulnerable to attacks using IPv4 mapped 677 * source. 678 */ 679 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 680 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 681 ip6stat.ip6s_badscope++; 682 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 683 goto bad; 684 } 685 686 /* 687 * Tell launch routine the next header 688 */ 689 ip6stat.ip6s_delivered++; 690 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 691 nest = 0; 692 while (nxt != IPPROTO_DONE) { 693 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 694 ip6stat.ip6s_toomanyhdr++; 695 goto bad; 696 } 697 698 /* 699 * protection against faulty packet - there should be 700 * more sanity checks in header chain processing. 701 */ 702 if (m->m_pkthdr.len < off) { 703 ip6stat.ip6s_tooshort++; 704 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 705 goto bad; 706 } 707 708 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 709 } 710 return; 711 bad: 712 m_freem(m); 713 } 714 715 /* 716 * Hop-by-Hop options header processing. If a valid jumbo payload option is 717 * included, the real payload length will be stored in plenp. 718 */ 719 static int 720 ip6_hopopts_input(plenp, rtalertp, mp, offp) 721 u_int32_t *plenp; 722 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 723 struct mbuf **mp; 724 int *offp; 725 { 726 register struct mbuf *m = *mp; 727 int off = *offp, hbhlen; 728 struct ip6_hbh *hbh; 729 u_int8_t *opt; 730 731 /* validation of the length of the header */ 732 #ifndef PULLDOWN_TEST 733 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 734 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 735 hbhlen = (hbh->ip6h_len + 1) << 3; 736 737 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 738 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 739 #else 740 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 741 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 742 if (hbh == NULL) { 743 ip6stat.ip6s_tooshort++; 744 return -1; 745 } 746 hbhlen = (hbh->ip6h_len + 1) << 3; 747 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 748 hbhlen); 749 if (hbh == NULL) { 750 ip6stat.ip6s_tooshort++; 751 return -1; 752 } 753 #endif 754 off += hbhlen; 755 hbhlen -= sizeof(struct ip6_hbh); 756 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 757 758 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 759 hbhlen, rtalertp, plenp) < 0) 760 return(-1); 761 762 *offp = off; 763 *mp = m; 764 return(0); 765 } 766 767 /* 768 * Search header for all Hop-by-hop options and process each option. 769 * This function is separate from ip6_hopopts_input() in order to 770 * handle a case where the sending node itself process its hop-by-hop 771 * options header. In such a case, the function is called from ip6_output(). 772 */ 773 int 774 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 775 struct mbuf *m; 776 u_int8_t *opthead; 777 int hbhlen; 778 u_int32_t *rtalertp; 779 u_int32_t *plenp; 780 { 781 struct ip6_hdr *ip6; 782 int optlen = 0; 783 u_int8_t *opt = opthead; 784 u_int16_t rtalert_val; 785 u_int32_t jumboplen; 786 787 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 788 switch(*opt) { 789 case IP6OPT_PAD1: 790 optlen = 1; 791 break; 792 case IP6OPT_PADN: 793 if (hbhlen < IP6OPT_MINLEN) { 794 ip6stat.ip6s_toosmall++; 795 goto bad; 796 } 797 optlen = *(opt + 1) + 2; 798 break; 799 case IP6OPT_RTALERT: 800 /* XXX may need check for alignment */ 801 if (hbhlen < IP6OPT_RTALERT_LEN) { 802 ip6stat.ip6s_toosmall++; 803 goto bad; 804 } 805 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) 806 /* XXX: should we discard the packet? */ 807 log(LOG_ERR, "length of router alert opt is inconsitent(%d)", 808 *(opt + 1)); 809 optlen = IP6OPT_RTALERT_LEN; 810 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 811 *rtalertp = ntohs(rtalert_val); 812 break; 813 case IP6OPT_JUMBO: 814 /* XXX may need check for alignment */ 815 if (hbhlen < IP6OPT_JUMBO_LEN) { 816 ip6stat.ip6s_toosmall++; 817 goto bad; 818 } 819 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) 820 /* XXX: should we discard the packet? */ 821 log(LOG_ERR, "length of jumbopayload opt " 822 "is inconsistent(%d)", 823 *(opt + 1)); 824 optlen = IP6OPT_JUMBO_LEN; 825 826 /* 827 * IPv6 packets that have non 0 payload length 828 * must not contain a jumbo paylod option. 829 */ 830 ip6 = mtod(m, struct ip6_hdr *); 831 if (ip6->ip6_plen) { 832 ip6stat.ip6s_badoptions++; 833 icmp6_error(m, ICMP6_PARAM_PROB, 834 ICMP6_PARAMPROB_HEADER, 835 sizeof(struct ip6_hdr) + 836 sizeof(struct ip6_hbh) + 837 opt - opthead); 838 return(-1); 839 } 840 841 /* 842 * We may see jumbolen in unaligned location, so 843 * we'd need to perform bcopy(). 844 */ 845 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 846 jumboplen = (u_int32_t)htonl(jumboplen); 847 848 #if 1 849 /* 850 * if there are multiple jumbo payload options, 851 * *plenp will be non-zero and the packet will be 852 * rejected. 853 * the behavior may need some debate in ipngwg - 854 * multiple options does not make sense, however, 855 * there's no explicit mention in specification. 856 */ 857 if (*plenp != 0) { 858 ip6stat.ip6s_badoptions++; 859 icmp6_error(m, ICMP6_PARAM_PROB, 860 ICMP6_PARAMPROB_HEADER, 861 sizeof(struct ip6_hdr) + 862 sizeof(struct ip6_hbh) + 863 opt + 2 - opthead); 864 return(-1); 865 } 866 #endif 867 868 /* 869 * jumbo payload length must be larger than 65535. 870 */ 871 if (jumboplen <= IPV6_MAXPACKET) { 872 ip6stat.ip6s_badoptions++; 873 icmp6_error(m, ICMP6_PARAM_PROB, 874 ICMP6_PARAMPROB_HEADER, 875 sizeof(struct ip6_hdr) + 876 sizeof(struct ip6_hbh) + 877 opt + 2 - opthead); 878 return(-1); 879 } 880 *plenp = jumboplen; 881 882 break; 883 default: /* unknown option */ 884 if (hbhlen < IP6OPT_MINLEN) { 885 ip6stat.ip6s_toosmall++; 886 goto bad; 887 } 888 if ((optlen = ip6_unknown_opt(opt, m, 889 sizeof(struct ip6_hdr) + 890 sizeof(struct ip6_hbh) + 891 opt - opthead)) == -1) 892 return(-1); 893 optlen += 2; 894 break; 895 } 896 } 897 898 return(0); 899 900 bad: 901 m_freem(m); 902 return(-1); 903 } 904 905 /* 906 * Unknown option processing. 907 * The third argument `off' is the offset from the IPv6 header to the option, 908 * which is necessary if the IPv6 header the and option header and IPv6 header 909 * is not continuous in order to return an ICMPv6 error. 910 */ 911 int 912 ip6_unknown_opt(optp, m, off) 913 u_int8_t *optp; 914 struct mbuf *m; 915 int off; 916 { 917 struct ip6_hdr *ip6; 918 919 switch(IP6OPT_TYPE(*optp)) { 920 case IP6OPT_TYPE_SKIP: /* ignore the option */ 921 return((int)*(optp + 1)); 922 case IP6OPT_TYPE_DISCARD: /* silently discard */ 923 m_freem(m); 924 return(-1); 925 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 926 ip6stat.ip6s_badoptions++; 927 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 928 return(-1); 929 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 930 ip6stat.ip6s_badoptions++; 931 ip6 = mtod(m, struct ip6_hdr *); 932 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 933 (m->m_flags & (M_BCAST|M_MCAST))) 934 m_freem(m); 935 else 936 icmp6_error(m, ICMP6_PARAM_PROB, 937 ICMP6_PARAMPROB_OPTION, off); 938 return(-1); 939 } 940 941 m_freem(m); /* XXX: NOTREACHED */ 942 return(-1); 943 } 944 945 /* 946 * Create the "control" list for this pcb. 947 * 948 * The routine will be called from upper layer handlers like tcp6_input(). 949 * Thus the routine assumes that the caller (tcp6_input) have already 950 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 951 * very first mbuf on the mbuf chain. 952 * We may want to add some infinite loop prevention or sanity checks for safety. 953 * (This applies only when you are using KAME mbuf chain restriction, i.e. 954 * you are using IP6_EXTHDR_CHECK() not m_pulldown()) 955 */ 956 void 957 ip6_savecontrol(in6p, mp, ip6, m) 958 register struct in6pcb *in6p; 959 register struct mbuf **mp; 960 register struct ip6_hdr *ip6; 961 register struct mbuf *m; 962 { 963 struct proc *p = curproc; /* XXX */ 964 int privileged; 965 966 privileged = 0; 967 if (p && !suser(p)) 968 privileged++; 969 970 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 971 struct timeval tv; 972 973 microtime(&tv); 974 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 975 SCM_TIMESTAMP, SOL_SOCKET); 976 if (*mp) 977 mp = &(*mp)->m_next; 978 } 979 980 #ifdef noyet 981 /* options were tossed above */ 982 if (in6p->in6p_flags & IN6P_RECVOPTS) 983 /* broken */ 984 /* ip6_srcroute doesn't do what we want here, need to fix */ 985 if (in6p->in6p_flags & IPV6P_RECVRETOPTS) 986 /* broken */ 987 #endif 988 989 /* RFC 2292 sec. 5 */ 990 if (in6p->in6p_flags & IN6P_PKTINFO) { 991 struct in6_pktinfo pi6; 992 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 993 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 994 pi6.ipi6_addr.s6_addr16[1] = 0; 995 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 996 ? m->m_pkthdr.rcvif->if_index 997 : 0; 998 *mp = sbcreatecontrol((caddr_t) &pi6, 999 sizeof(struct in6_pktinfo), IPV6_PKTINFO, 1000 IPPROTO_IPV6); 1001 if (*mp) 1002 mp = &(*mp)->m_next; 1003 } 1004 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1005 int hlim = ip6->ip6_hlim & 0xff; 1006 *mp = sbcreatecontrol((caddr_t) &hlim, 1007 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); 1008 if (*mp) 1009 mp = &(*mp)->m_next; 1010 } 1011 /* IN6P_NEXTHOP - for outgoing packet only */ 1012 1013 /* 1014 * IPV6_HOPOPTS socket option. We require super-user privilege 1015 * for the option, but it might be too strict, since there might 1016 * be some hop-by-hop options which can be returned to normal user. 1017 * See RFC 2292 section 6. 1018 */ 1019 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1020 /* 1021 * Check if a hop-by-hop options header is contatined in the 1022 * received packet, and if so, store the options as ancillary 1023 * data. Note that a hop-by-hop options header must be 1024 * just after the IPv6 header, which fact is assured through 1025 * the IPv6 input processing. 1026 */ 1027 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1028 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1029 struct ip6_hbh *hbh; 1030 int hbhlen; 1031 1032 #ifndef PULLDOWN_TEST 1033 hbh = (struct ip6_hbh *)(ip6 + 1); 1034 hbhlen = (hbh->ip6h_len + 1) << 3; 1035 #else 1036 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 1037 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 1038 if (hbh == NULL) { 1039 ip6stat.ip6s_tooshort++; 1040 return; 1041 } 1042 hbhlen = (hbh->ip6h_len + 1) << 3; 1043 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 1044 sizeof(struct ip6_hdr), hbhlen); 1045 if (hbh == NULL) { 1046 ip6stat.ip6s_tooshort++; 1047 return; 1048 } 1049 #endif 1050 1051 /* 1052 * XXX: We copy whole the header even if a jumbo 1053 * payload option is included, which option is to 1054 * be removed before returning in the RFC 2292. 1055 * But it's too painful operation... 1056 */ 1057 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1058 IPV6_HOPOPTS, IPPROTO_IPV6); 1059 if (*mp) 1060 mp = &(*mp)->m_next; 1061 } 1062 } 1063 1064 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1065 if (in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDR)) { 1066 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1067 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);; 1068 1069 /* 1070 * Search for destination options headers or routing 1071 * header(s) through the header chain, and stores each 1072 * header as ancillary data. 1073 * Note that the order of the headers remains in 1074 * the chain of ancillary data. 1075 */ 1076 while(1) { /* is explicit loop prevention necessary? */ 1077 struct ip6_ext *ip6e; 1078 int elen; 1079 1080 #ifndef PULLDOWN_TEST 1081 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1082 if (nxt == IPPROTO_AH) 1083 elen = (ip6e->ip6e_len + 2) << 2; 1084 else 1085 elen = (ip6e->ip6e_len + 1) << 3; 1086 #else 1087 IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off, 1088 sizeof(struct ip6_ext)); 1089 if (ip6e == NULL) { 1090 ip6stat.ip6s_tooshort++; 1091 return; 1092 } 1093 if (nxt == IPPROTO_AH) 1094 elen = (ip6e->ip6e_len + 2) << 2; 1095 else 1096 elen = (ip6e->ip6e_len + 1) << 3; 1097 IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off, elen); 1098 if (ip6e == NULL) { 1099 ip6stat.ip6s_tooshort++; 1100 return; 1101 } 1102 #endif 1103 1104 switch(nxt) { 1105 case IPPROTO_DSTOPTS: 1106 if (!in6p->in6p_flags & IN6P_DSTOPTS) 1107 break; 1108 1109 /* 1110 * We also require super-user privilege for 1111 * the option. 1112 * See the comments on IN6_HOPOPTS. 1113 */ 1114 if (!privileged) 1115 break; 1116 1117 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1118 IPV6_DSTOPTS, 1119 IPPROTO_IPV6); 1120 if (*mp) 1121 mp = &(*mp)->m_next; 1122 break; 1123 1124 case IPPROTO_ROUTING: 1125 if (!in6p->in6p_flags & IN6P_RTHDR) 1126 break; 1127 1128 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1129 IPV6_RTHDR, 1130 IPPROTO_IPV6); 1131 if (*mp) 1132 mp = &(*mp)->m_next; 1133 break; 1134 1135 case IPPROTO_UDP: 1136 case IPPROTO_TCP: 1137 case IPPROTO_ICMPV6: 1138 default: 1139 /* 1140 * stop search if we encounter an upper 1141 * layer protocol headers. 1142 */ 1143 goto loopend; 1144 1145 case IPPROTO_HOPOPTS: 1146 case IPPROTO_AH: /* is it possible? */ 1147 break; 1148 } 1149 1150 /* proceed with the next header. */ 1151 off += elen; 1152 nxt = ip6e->ip6e_nxt; 1153 } 1154 loopend: 1155 } 1156 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1157 /* to be done */ 1158 } 1159 if ((in6p->in6p_flags & IN6P_DSTOPTS) && privileged) { 1160 /* to be done */ 1161 } 1162 /* IN6P_RTHDR - to be done */ 1163 1164 } 1165 1166 /* 1167 * Get pointer to the previous header followed by the header 1168 * currently processed. 1169 * XXX: This function supposes that 1170 * M includes all headers, 1171 * the next header field and the header length field of each header 1172 * are valid, and 1173 * the sum of each header length equals to OFF. 1174 * Because of these assumptions, this function must be called very 1175 * carefully. Moreover, it will not be used in the near future when 1176 * we develop `neater' mechanism to process extension headers. 1177 */ 1178 char * 1179 ip6_get_prevhdr(m, off) 1180 struct mbuf *m; 1181 int off; 1182 { 1183 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1184 1185 if (off == sizeof(struct ip6_hdr)) 1186 return(&ip6->ip6_nxt); 1187 else { 1188 int len, nxt; 1189 struct ip6_ext *ip6e = NULL; 1190 1191 nxt = ip6->ip6_nxt; 1192 len = sizeof(struct ip6_hdr); 1193 while (len < off) { 1194 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1195 1196 switch(nxt) { 1197 case IPPROTO_FRAGMENT: 1198 len += sizeof(struct ip6_frag); 1199 break; 1200 case IPPROTO_AH: 1201 len += (ip6e->ip6e_len + 2) << 2; 1202 break; 1203 default: 1204 len += (ip6e->ip6e_len + 1) << 3; 1205 break; 1206 } 1207 nxt = ip6e->ip6e_nxt; 1208 } 1209 if (ip6e) 1210 return(&ip6e->ip6e_nxt); 1211 else 1212 return NULL; 1213 } 1214 } 1215 1216 /* 1217 * get next header offset. m will be retained. 1218 */ 1219 int 1220 ip6_nexthdr(m, off, proto, nxtp) 1221 struct mbuf *m; 1222 int off; 1223 int proto; 1224 int *nxtp; 1225 { 1226 struct ip6_hdr ip6; 1227 struct ip6_ext ip6e; 1228 struct ip6_frag fh; 1229 1230 /* just in case */ 1231 if (m == NULL) 1232 panic("ip6_nexthdr: m == NULL"); 1233 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1234 return -1; 1235 1236 switch (proto) { 1237 case IPPROTO_IPV6: 1238 if (m->m_pkthdr.len < off + sizeof(ip6)) 1239 return -1; 1240 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1241 if (nxtp) 1242 *nxtp = ip6.ip6_nxt; 1243 off += sizeof(ip6); 1244 return off; 1245 1246 case IPPROTO_FRAGMENT: 1247 /* 1248 * terminate parsing if it is not the first fragment, 1249 * it does not make sense to parse through it. 1250 */ 1251 if (m->m_pkthdr.len < off + sizeof(fh)) 1252 return -1; 1253 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1254 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) 1255 return -1; 1256 if (nxtp) 1257 *nxtp = fh.ip6f_nxt; 1258 off += sizeof(struct ip6_frag); 1259 return off; 1260 1261 case IPPROTO_AH: 1262 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1263 return -1; 1264 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1265 if (nxtp) 1266 *nxtp = ip6e.ip6e_nxt; 1267 off += (ip6e.ip6e_len + 2) << 2; 1268 return off; 1269 1270 case IPPROTO_HOPOPTS: 1271 case IPPROTO_ROUTING: 1272 case IPPROTO_DSTOPTS: 1273 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1274 return -1; 1275 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1276 if (nxtp) 1277 *nxtp = ip6e.ip6e_nxt; 1278 off += (ip6e.ip6e_len + 1) << 3; 1279 return off; 1280 1281 case IPPROTO_NONE: 1282 case IPPROTO_ESP: 1283 case IPPROTO_IPCOMP: 1284 /* give up */ 1285 return -1; 1286 1287 default: 1288 return -1; 1289 } 1290 1291 return -1; 1292 } 1293 1294 /* 1295 * get offset for the last header in the chain. m will be kept untainted. 1296 */ 1297 int 1298 ip6_lasthdr(m, off, proto, nxtp) 1299 struct mbuf *m; 1300 int off; 1301 int proto; 1302 int *nxtp; 1303 { 1304 int newoff; 1305 int nxt; 1306 1307 if (!nxtp) { 1308 nxt = -1; 1309 nxtp = &nxt; 1310 } 1311 while (1) { 1312 newoff = ip6_nexthdr(m, off, proto, nxtp); 1313 if (newoff < 0) 1314 return off; 1315 else if (newoff < off) 1316 return -1; /* invalid */ 1317 else if (newoff == off) 1318 return newoff; 1319 1320 off = newoff; 1321 proto = *nxtp; 1322 } 1323 } 1324 1325 /* 1326 * System control for IP6 1327 */ 1328 1329 u_char inet6ctlerrmap[PRC_NCMDS] = { 1330 0, 0, 0, 0, 1331 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1332 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1333 EMSGSIZE, EHOSTUNREACH, 0, 0, 1334 0, 0, 0, 0, 1335 ENOPROTOOPT 1336 }; 1337