1 /* $OpenBSD: ip6_input.c,v 1.103 2012/04/03 15:03:08 mikeb Exp $ */ 2 /* $KAME: ip6_input.c,v 1.188 2001/03/29 05:34:31 itojun 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. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include "pf.h" 65 #include "carp.h" 66 67 #include <sys/param.h> 68 #include <sys/systm.h> 69 #include <sys/malloc.h> 70 #include <sys/mbuf.h> 71 #include <sys/domain.h> 72 #include <sys/protosw.h> 73 #include <sys/socket.h> 74 #include <sys/socketvar.h> 75 #include <sys/errno.h> 76 #include <sys/time.h> 77 #include <sys/kernel.h> 78 #include <sys/syslog.h> 79 #include <sys/proc.h> 80 81 #include <net/if.h> 82 #include <net/if_types.h> 83 #include <net/if_dl.h> 84 #include <net/route.h> 85 #include <net/netisr.h> 86 87 #include <netinet/in.h> 88 #include <netinet/in_systm.h> 89 90 #ifdef INET 91 #include <netinet/ip.h> 92 #endif 93 94 #include <netinet/in_pcb.h> 95 #include <netinet6/in6_var.h> 96 #include <netinet/ip6.h> 97 #include <netinet6/ip6_var.h> 98 #include <netinet/icmp6.h> 99 #include <netinet6/in6_ifattach.h> 100 #include <netinet6/nd6.h> 101 102 #include <netinet6/ip6protosw.h> 103 104 #include "faith.h" 105 #include "gif.h" 106 #include "bpfilter.h" 107 108 #ifdef MROUTING 109 #include <netinet6/ip6_mroute.h> 110 #endif 111 112 #if NPF > 0 113 #include <net/pfvar.h> 114 #endif 115 116 #if NCARP > 0 117 #include <netinet/in_var.h> 118 #include <netinet/ip_carp.h> 119 #endif 120 121 extern struct domain inet6domain; 122 extern struct ip6protosw inet6sw[]; 123 124 u_char ip6_protox[IPPROTO_MAX]; 125 static int ip6qmaxlen = IFQ_MAXLEN; 126 struct in6_ifaddr *in6_ifaddr; 127 struct ifqueue ip6intrq; 128 129 struct ip6stat ip6stat; 130 131 void ip6_init2(void *); 132 int ip6_check_rh0hdr(struct mbuf *, int *); 133 134 int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 135 struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 136 137 /* 138 * IP6 initialization: fill in IP6 protocol switch table. 139 * All protocols not implemented in kernel go to raw IP6 protocol handler. 140 */ 141 void 142 ip6_init(void) 143 { 144 struct ip6protosw *pr; 145 int i; 146 147 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 148 if (pr == 0) 149 panic("ip6_init"); 150 for (i = 0; i < IPPROTO_MAX; i++) 151 ip6_protox[i] = pr - inet6sw; 152 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 153 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 154 if (pr->pr_domain->dom_family == PF_INET6 && 155 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW && 156 pr->pr_protocol < IPPROTO_MAX) 157 ip6_protox[pr->pr_protocol] = pr - inet6sw; 158 IFQ_SET_MAXLEN(&ip6intrq, ip6qmaxlen); 159 ip6_randomid_init(); 160 nd6_init(); 161 frag6_init(); 162 ip6_init2((void *)0); 163 } 164 165 void 166 ip6_init2(void *dummy) 167 { 168 169 /* nd6_timer_init */ 170 bzero(&nd6_timer_ch, sizeof(nd6_timer_ch)); 171 timeout_set(&nd6_timer_ch, nd6_timer, NULL); 172 timeout_add_sec(&nd6_timer_ch, 1); 173 } 174 175 /* 176 * IP6 input interrupt handling. Just pass the packet to ip6_input. 177 */ 178 void 179 ip6intr(void) 180 { 181 int s; 182 struct mbuf *m; 183 184 for (;;) { 185 s = splnet(); 186 IF_DEQUEUE(&ip6intrq, m); 187 splx(s); 188 if (m == NULL) 189 return; 190 ip6_input(m); 191 } 192 } 193 194 extern struct route_in6 ip6_forward_rt; 195 196 void 197 ip6_input(struct mbuf *m) 198 { 199 struct ip6_hdr *ip6; 200 int off, nest; 201 u_int32_t plen; 202 u_int32_t rtalert = ~0; 203 int nxt, ours = 0; 204 struct ifnet *deliverifp = NULL; 205 #if NPF > 0 206 struct in6_addr odst; 207 #endif 208 int srcrt = 0, isanycast = 0; 209 u_int rtableid = 0; 210 211 /* 212 * mbuf statistics by kazu 213 */ 214 if (m->m_flags & M_EXT) { 215 if (m->m_next) 216 ip6stat.ip6s_mext2m++; 217 else 218 ip6stat.ip6s_mext1++; 219 } else { 220 if (m->m_next) { 221 if (m->m_flags & M_LOOP) { 222 ip6stat.ip6s_m2m[lo0ifp->if_index]++; /*XXX*/ 223 } else if (m->m_pkthdr.rcvif->if_index < nitems(ip6stat.ip6s_m2m)) 224 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 225 else 226 ip6stat.ip6s_m2m[0]++; 227 } else 228 ip6stat.ip6s_m1++; 229 } 230 231 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 232 ip6stat.ip6s_total++; 233 234 if (m->m_len < sizeof(struct ip6_hdr)) { 235 struct ifnet *inifp; 236 inifp = m->m_pkthdr.rcvif; 237 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 238 ip6stat.ip6s_toosmall++; 239 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 240 return; 241 } 242 } 243 244 ip6 = mtod(m, struct ip6_hdr *); 245 246 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 247 ip6stat.ip6s_badvers++; 248 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 249 goto bad; 250 } 251 252 #if NCARP > 0 253 if (m->m_pkthdr.rcvif->if_type == IFT_CARP && 254 ip6->ip6_nxt != IPPROTO_ICMPV6 && 255 carp_lsdrop(m, AF_INET6, ip6->ip6_src.s6_addr32, 256 ip6->ip6_dst.s6_addr32)) 257 goto bad; 258 #endif 259 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 260 261 /* 262 * Check against address spoofing/corruption. 263 */ 264 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 265 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 266 /* 267 * XXX: "badscope" is not very suitable for a multicast source. 268 */ 269 ip6stat.ip6s_badscope++; 270 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 271 goto bad; 272 } 273 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 274 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 275 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 276 ip6stat.ip6s_badscope++; 277 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 278 goto bad; 279 } 280 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 281 !(m->m_flags & M_LOOP)) { 282 /* 283 * In this case, the packet should come from the loopback 284 * interface. However, we cannot just check the if_flags, 285 * because ip6_mloopback() passes the "actual" interface 286 * as the outgoing/incoming interface. 287 */ 288 ip6stat.ip6s_badscope++; 289 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 290 goto bad; 291 } 292 293 /* 294 * The following check is not documented in specs. A malicious 295 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 296 * and bypass security checks (act as if it was from 127.0.0.1 by using 297 * IPv6 src ::ffff:127.0.0.1). Be cautious. 298 * 299 * This check chokes if we are in an SIIT cloud. As none of BSDs 300 * support IPv4-less kernel compilation, we cannot support SIIT 301 * environment at all. So, it makes more sense for us to reject any 302 * malicious packets for non-SIIT environment, than try to do a 303 * partial support for SIIT environment. 304 */ 305 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 306 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 307 ip6stat.ip6s_badscope++; 308 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 309 goto bad; 310 } 311 #if 0 312 /* 313 * Reject packets with IPv4 compatible addresses (auto tunnel). 314 * 315 * The code forbids auto tunnel relay case in RFC1933 (the check is 316 * stronger than RFC1933). We may want to re-enable it if mech-xx 317 * is revised to forbid relaying case. 318 */ 319 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 320 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 321 ip6stat.ip6s_badscope++; 322 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 323 goto bad; 324 } 325 #endif 326 327 if (ip6_check_rh0hdr(m, &off)) { 328 ip6stat.ip6s_badoptions++; 329 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 330 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 331 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, off); 332 /* m is already freed */ 333 return; 334 } 335 336 #if NPF > 0 337 /* 338 * Packet filter 339 */ 340 odst = ip6->ip6_dst; 341 if (pf_test(AF_INET6, PF_IN, m->m_pkthdr.rcvif, &m, NULL) != PF_PASS) 342 goto bad; 343 if (m == NULL) 344 return; 345 346 ip6 = mtod(m, struct ip6_hdr *); 347 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 348 #endif 349 350 if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 351 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) { 352 ours = 1; 353 deliverifp = m->m_pkthdr.rcvif; 354 goto hbhcheck; 355 } 356 357 /* drop packets if interface ID portion is already filled */ 358 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 359 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src) && 360 ip6->ip6_src.s6_addr16[1]) { 361 ip6stat.ip6s_badscope++; 362 goto bad; 363 } 364 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst) && 365 ip6->ip6_dst.s6_addr16[1]) { 366 ip6stat.ip6s_badscope++; 367 goto bad; 368 } 369 } 370 371 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) 372 ip6->ip6_src.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 373 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) 374 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 375 376 /* 377 * We use rt->rt_ifp to determine if the address is ours or not. 378 * If rt_ifp is lo0, the address is ours. 379 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 380 * so any address under fe80::%lo0/64 will be mistakenly considered 381 * local. The special case is supplied to handle the case properly 382 * by actually looking at interface addresses 383 * (using in6ifa_ifpwithaddr). 384 */ 385 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 386 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 387 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 388 icmp6_error(m, ICMP6_DST_UNREACH, 389 ICMP6_DST_UNREACH_ADDR, 0); 390 /* m is already freed */ 391 return; 392 } 393 394 ours = 1; 395 deliverifp = m->m_pkthdr.rcvif; 396 goto hbhcheck; 397 } 398 399 if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) { 400 ours = 1; 401 deliverifp = m->m_pkthdr.rcvif; 402 goto hbhcheck; 403 } 404 405 /* 406 * Multicast check 407 */ 408 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 409 struct in6_multi *in6m = 0; 410 411 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 412 /* 413 * See if we belong to the destination multicast group on the 414 * arrival interface. 415 */ 416 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 417 if (in6m) 418 ours = 1; 419 #ifdef MROUTING 420 else if (!ip6_mforwarding || !ip6_mrouter) 421 #else 422 else 423 #endif 424 { 425 ip6stat.ip6s_notmember++; 426 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 427 ip6stat.ip6s_cantforward++; 428 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 429 goto bad; 430 } 431 deliverifp = m->m_pkthdr.rcvif; 432 goto hbhcheck; 433 } 434 435 #if NPF > 0 436 rtableid = m->m_pkthdr.rdomain; 437 #endif 438 439 /* 440 * Unicast check 441 */ 442 if (ip6_forward_rt.ro_rt != NULL && 443 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 444 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 445 &ip6_forward_rt.ro_dst.sin6_addr) && 446 rtableid == ip6_forward_rt.ro_tableid) 447 ip6stat.ip6s_forward_cachehit++; 448 else { 449 if (ip6_forward_rt.ro_rt) { 450 /* route is down or destination is different */ 451 ip6stat.ip6s_forward_cachemiss++; 452 RTFREE(ip6_forward_rt.ro_rt); 453 ip6_forward_rt.ro_rt = 0; 454 } 455 456 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 457 ip6_forward_rt.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 458 ip6_forward_rt.ro_dst.sin6_family = AF_INET6; 459 ip6_forward_rt.ro_dst.sin6_addr = ip6->ip6_dst; 460 ip6_forward_rt.ro_tableid = rtableid; 461 462 rtalloc_mpath((struct route *)&ip6_forward_rt, 463 &ip6->ip6_src.s6_addr32[0]); 464 } 465 466 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 467 468 /* 469 * Accept the packet if the forwarding interface to the destination 470 * according to the routing table is the loopback interface, 471 * unless the associated route has a gateway. 472 * Note that this approach causes to accept a packet if there is a 473 * route to the loopback interface for the destination of the packet. 474 * But we think it's even useful in some situations, e.g. when using 475 * a special daemon which wants to intercept the packet. 476 */ 477 if (ip6_forward_rt.ro_rt && 478 (ip6_forward_rt.ro_rt->rt_flags & 479 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 480 #if 0 481 /* 482 * The check below is redundant since the comparison of 483 * the destination and the key of the rtentry has 484 * already done through looking up the routing table. 485 */ 486 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 487 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) && 488 #endif 489 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 490 struct in6_ifaddr *ia6 = 491 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 492 if (ia6->ia6_flags & IN6_IFF_ANYCAST) 493 isanycast = 1; 494 /* 495 * packets to a tentative, duplicated, or somehow invalid 496 * address must not be accepted. 497 */ 498 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 499 /* this address is ready */ 500 ours = 1; 501 deliverifp = ia6->ia_ifp; /* correct? */ 502 goto hbhcheck; 503 } else { 504 /* address is not ready, so discard the packet. */ 505 nd6log((LOG_INFO, 506 "ip6_input: packet to an unready address %s->%s\n", 507 ip6_sprintf(&ip6->ip6_src), 508 ip6_sprintf(&ip6->ip6_dst))); 509 510 goto bad; 511 } 512 } 513 514 /* 515 * FAITH (Firewall Aided Internet Translator) 516 */ 517 #if defined(NFAITH) && 0 < NFAITH 518 if (ip6_keepfaith) { 519 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 520 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 521 /* XXX do we need more sanity checks? */ 522 ours = 1; 523 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /*faith*/ 524 goto hbhcheck; 525 } 526 } 527 #endif 528 529 #if 0 530 { 531 /* 532 * Last resort: check in6_ifaddr for incoming interface. 533 * The code is here until I update the "goto ours hack" code above 534 * working right. 535 */ 536 struct ifaddr *ifa; 537 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) { 538 if (ifa->ifa_addr == NULL) 539 continue; /* just for safety */ 540 if (ifa->ifa_addr->sa_family != AF_INET6) 541 continue; 542 if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ip6->ip6_dst)) { 543 ours = 1; 544 deliverifp = ifa->ifa_ifp; 545 goto hbhcheck; 546 } 547 } 548 } 549 #endif 550 551 #if NCARP > 0 552 if (m->m_pkthdr.rcvif->if_type == IFT_CARP && 553 ip6->ip6_nxt == IPPROTO_ICMPV6 && 554 carp_lsdrop(m, AF_INET6, ip6->ip6_src.s6_addr32, 555 ip6->ip6_dst.s6_addr32)) 556 goto bad; 557 #endif 558 /* 559 * Now there is no reason to process the packet if it's not our own 560 * and we're not a router. 561 */ 562 if (!ip6_forwarding) { 563 ip6stat.ip6s_cantforward++; 564 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 565 goto bad; 566 } 567 568 hbhcheck: 569 /* 570 * Process Hop-by-Hop options header if it's contained. 571 * m may be modified in ip6_hopopts_input(). 572 * If a JumboPayload option is included, plen will also be modified. 573 */ 574 plen = (u_int32_t)ntohs(ip6->ip6_plen); 575 off = sizeof(struct ip6_hdr); 576 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 577 struct ip6_hbh *hbh; 578 579 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 580 #if 0 /*touches NULL pointer*/ 581 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 582 #endif 583 return; /* m have already been freed */ 584 } 585 586 /* adjust pointer */ 587 ip6 = mtod(m, struct ip6_hdr *); 588 589 /* 590 * if the payload length field is 0 and the next header field 591 * indicates Hop-by-Hop Options header, then a Jumbo Payload 592 * option MUST be included. 593 */ 594 if (ip6->ip6_plen == 0 && plen == 0) { 595 /* 596 * Note that if a valid jumbo payload option is 597 * contained, ip6_hoptops_input() must set a valid 598 * (non-zero) payload length to the variable plen. 599 */ 600 ip6stat.ip6s_badoptions++; 601 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 602 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 603 icmp6_error(m, ICMP6_PARAM_PROB, 604 ICMP6_PARAMPROB_HEADER, 605 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 606 return; 607 } 608 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 609 sizeof(struct ip6_hbh)); 610 if (hbh == NULL) { 611 ip6stat.ip6s_tooshort++; 612 return; 613 } 614 nxt = hbh->ip6h_nxt; 615 616 /* 617 * accept the packet if a router alert option is included 618 * and we act as an IPv6 router. 619 */ 620 if (rtalert != ~0 && ip6_forwarding) 621 ours = 1; 622 } else 623 nxt = ip6->ip6_nxt; 624 625 /* 626 * Check that the amount of data in the buffers 627 * is as at least much as the IPv6 header would have us expect. 628 * Trim mbufs if longer than we expect. 629 * Drop packet if shorter than we expect. 630 */ 631 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 632 ip6stat.ip6s_tooshort++; 633 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 634 goto bad; 635 } 636 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 637 if (m->m_len == m->m_pkthdr.len) { 638 m->m_len = sizeof(struct ip6_hdr) + plen; 639 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 640 } else 641 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 642 } 643 644 /* 645 * Forward if desirable. 646 */ 647 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 648 /* 649 * If we are acting as a multicast router, all 650 * incoming multicast packets are passed to the 651 * kernel-level multicast forwarding function. 652 * The packet is returned (relatively) intact; if 653 * ip6_mforward() returns a non-zero value, the packet 654 * must be discarded, else it may be accepted below. 655 */ 656 #ifdef MROUTING 657 if (ip6_mforwarding && ip6_mrouter && 658 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 659 ip6stat.ip6s_cantforward++; 660 m_freem(m); 661 return; 662 } 663 #endif 664 if (!ours) { 665 m_freem(m); 666 return; 667 } 668 } else if (!ours) { 669 ip6_forward(m, srcrt); 670 return; 671 } 672 673 ip6 = mtod(m, struct ip6_hdr *); 674 675 /* 676 * Malicious party may be able to use IPv4 mapped addr to confuse 677 * tcp/udp stack and bypass security checks (act as if it was from 678 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 679 * 680 * For SIIT end node behavior, you may want to disable the check. 681 * However, you will become vulnerable to attacks using IPv4 mapped 682 * source. 683 */ 684 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 685 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 686 ip6stat.ip6s_badscope++; 687 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 688 goto bad; 689 } 690 691 /* 692 * Tell launch routine the next header 693 */ 694 ip6stat.ip6s_delivered++; 695 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 696 nest = 0; 697 698 while (nxt != IPPROTO_DONE) { 699 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 700 ip6stat.ip6s_toomanyhdr++; 701 goto bad; 702 } 703 704 /* 705 * protection against faulty packet - there should be 706 * more sanity checks in header chain processing. 707 */ 708 if (m->m_pkthdr.len < off) { 709 ip6stat.ip6s_tooshort++; 710 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 711 goto bad; 712 } 713 714 /* draft-itojun-ipv6-tcp-to-anycast */ 715 if (isanycast && nxt == IPPROTO_TCP) { 716 if (m->m_len >= sizeof(struct ip6_hdr)) { 717 ip6 = mtod(m, struct ip6_hdr *); 718 icmp6_error(m, ICMP6_DST_UNREACH, 719 ICMP6_DST_UNREACH_ADDR, 720 (caddr_t)&ip6->ip6_dst - (caddr_t)ip6); 721 break; 722 } else 723 goto bad; 724 } 725 726 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 727 } 728 return; 729 bad: 730 m_freem(m); 731 } 732 733 /* scan packet for RH0 routing header. Mostly stolen from pf.c:pf_test() */ 734 int 735 ip6_check_rh0hdr(struct mbuf *m, int *offp) 736 { 737 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 738 struct ip6_rthdr rthdr; 739 struct ip6_ext opt6; 740 u_int8_t proto = ip6->ip6_nxt; 741 int done = 0, lim, off, rh_cnt = 0; 742 743 off = ((caddr_t)ip6 - m->m_data) + sizeof(struct ip6_hdr); 744 lim = min(m->m_pkthdr.len, ntohs(ip6->ip6_plen) + sizeof(*ip6)); 745 do { 746 switch (proto) { 747 case IPPROTO_ROUTING: 748 *offp = off; 749 if (rh_cnt++) { 750 /* more then one rh header present */ 751 return (1); 752 } 753 754 if (off + sizeof(rthdr) > lim) { 755 /* packet to short to make sense */ 756 return (1); 757 } 758 759 m_copydata(m, off, sizeof(rthdr), (caddr_t)&rthdr); 760 761 if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) { 762 *offp += offsetof(struct ip6_rthdr, ip6r_type); 763 return (1); 764 } 765 766 off += (rthdr.ip6r_len + 1) * 8; 767 proto = rthdr.ip6r_nxt; 768 break; 769 case IPPROTO_AH: 770 case IPPROTO_HOPOPTS: 771 case IPPROTO_DSTOPTS: 772 /* get next header and header length */ 773 if (off + sizeof(opt6) > lim) { 774 /* 775 * Packet to short to make sense, we could 776 * reject the packet but as a router we 777 * should not do that so forward it. 778 */ 779 return (0); 780 } 781 782 m_copydata(m, off, sizeof(opt6), (caddr_t)&opt6); 783 784 if (proto == IPPROTO_AH) 785 off += (opt6.ip6e_len + 2) * 4; 786 else 787 off += (opt6.ip6e_len + 1) * 8; 788 proto = opt6.ip6e_nxt; 789 break; 790 case IPPROTO_FRAGMENT: 791 default: 792 /* end of header stack */ 793 done = 1; 794 break; 795 } 796 } while (!done); 797 798 return (0); 799 } 800 801 /* 802 * Hop-by-Hop options header processing. If a valid jumbo payload option is 803 * included, the real payload length will be stored in plenp. 804 * 805 * rtalertp - XXX: should be stored in a more smart way 806 */ 807 int 808 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, struct mbuf **mp, 809 int *offp) 810 { 811 struct mbuf *m = *mp; 812 int off = *offp, hbhlen; 813 struct ip6_hbh *hbh; 814 815 /* validation of the length of the header */ 816 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 817 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 818 if (hbh == NULL) { 819 ip6stat.ip6s_tooshort++; 820 return -1; 821 } 822 hbhlen = (hbh->ip6h_len + 1) << 3; 823 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 824 hbhlen); 825 if (hbh == NULL) { 826 ip6stat.ip6s_tooshort++; 827 return -1; 828 } 829 off += hbhlen; 830 hbhlen -= sizeof(struct ip6_hbh); 831 832 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 833 hbhlen, rtalertp, plenp) < 0) 834 return (-1); 835 836 *offp = off; 837 *mp = m; 838 return (0); 839 } 840 841 /* 842 * Search header for all Hop-by-hop options and process each option. 843 * This function is separate from ip6_hopopts_input() in order to 844 * handle a case where the sending node itself process its hop-by-hop 845 * options header. In such a case, the function is called from ip6_output(). 846 * 847 * The function assumes that hbh header is located right after the IPv6 header 848 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 849 * opthead + hbhlen is located in continuous memory region. 850 */ 851 int 852 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 853 u_int32_t *rtalertp, u_int32_t *plenp) 854 { 855 struct ip6_hdr *ip6; 856 int optlen = 0; 857 u_int8_t *opt = opthead; 858 u_int16_t rtalert_val; 859 u_int32_t jumboplen; 860 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 861 862 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 863 switch (*opt) { 864 case IP6OPT_PAD1: 865 optlen = 1; 866 break; 867 case IP6OPT_PADN: 868 if (hbhlen < IP6OPT_MINLEN) { 869 ip6stat.ip6s_toosmall++; 870 goto bad; 871 } 872 optlen = *(opt + 1) + 2; 873 break; 874 case IP6OPT_ROUTER_ALERT: 875 /* XXX may need check for alignment */ 876 if (hbhlen < IP6OPT_RTALERT_LEN) { 877 ip6stat.ip6s_toosmall++; 878 goto bad; 879 } 880 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 881 /* XXX stat */ 882 icmp6_error(m, ICMP6_PARAM_PROB, 883 ICMP6_PARAMPROB_HEADER, 884 erroff + opt + 1 - opthead); 885 return (-1); 886 } 887 optlen = IP6OPT_RTALERT_LEN; 888 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 889 *rtalertp = ntohs(rtalert_val); 890 break; 891 case IP6OPT_JUMBO: 892 /* XXX may need check for alignment */ 893 if (hbhlen < IP6OPT_JUMBO_LEN) { 894 ip6stat.ip6s_toosmall++; 895 goto bad; 896 } 897 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 898 /* XXX stat */ 899 icmp6_error(m, ICMP6_PARAM_PROB, 900 ICMP6_PARAMPROB_HEADER, 901 erroff + opt + 1 - opthead); 902 return (-1); 903 } 904 optlen = IP6OPT_JUMBO_LEN; 905 906 /* 907 * IPv6 packets that have non 0 payload length 908 * must not contain a jumbo payload option. 909 */ 910 ip6 = mtod(m, struct ip6_hdr *); 911 if (ip6->ip6_plen) { 912 ip6stat.ip6s_badoptions++; 913 icmp6_error(m, ICMP6_PARAM_PROB, 914 ICMP6_PARAMPROB_HEADER, 915 erroff + opt - opthead); 916 return (-1); 917 } 918 919 /* 920 * We may see jumbolen in unaligned location, so 921 * we'd need to perform bcopy(). 922 */ 923 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 924 jumboplen = (u_int32_t)htonl(jumboplen); 925 926 #if 1 927 /* 928 * if there are multiple jumbo payload options, 929 * *plenp will be non-zero and the packet will be 930 * rejected. 931 * the behavior may need some debate in ipngwg - 932 * multiple options does not make sense, however, 933 * there's no explicit mention in specification. 934 */ 935 if (*plenp != 0) { 936 ip6stat.ip6s_badoptions++; 937 icmp6_error(m, ICMP6_PARAM_PROB, 938 ICMP6_PARAMPROB_HEADER, 939 erroff + opt + 2 - opthead); 940 return (-1); 941 } 942 #endif 943 944 /* 945 * jumbo payload length must be larger than 65535. 946 */ 947 if (jumboplen <= IPV6_MAXPACKET) { 948 ip6stat.ip6s_badoptions++; 949 icmp6_error(m, ICMP6_PARAM_PROB, 950 ICMP6_PARAMPROB_HEADER, 951 erroff + opt + 2 - opthead); 952 return (-1); 953 } 954 *plenp = jumboplen; 955 956 break; 957 default: /* unknown option */ 958 if (hbhlen < IP6OPT_MINLEN) { 959 ip6stat.ip6s_toosmall++; 960 goto bad; 961 } 962 optlen = ip6_unknown_opt(opt, m, 963 erroff + opt - opthead); 964 if (optlen == -1) 965 return (-1); 966 optlen += 2; 967 break; 968 } 969 } 970 971 return (0); 972 973 bad: 974 m_freem(m); 975 return (-1); 976 } 977 978 /* 979 * Unknown option processing. 980 * The third argument `off' is the offset from the IPv6 header to the option, 981 * which allows returning an ICMPv6 error even if the IPv6 header and the 982 * option header are not continuous. 983 */ 984 int 985 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 986 { 987 struct ip6_hdr *ip6; 988 989 switch (IP6OPT_TYPE(*optp)) { 990 case IP6OPT_TYPE_SKIP: /* ignore the option */ 991 return ((int)*(optp + 1)); 992 case IP6OPT_TYPE_DISCARD: /* silently discard */ 993 m_freem(m); 994 return (-1); 995 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 996 ip6stat.ip6s_badoptions++; 997 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 998 return (-1); 999 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1000 ip6stat.ip6s_badoptions++; 1001 ip6 = mtod(m, struct ip6_hdr *); 1002 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1003 (m->m_flags & (M_BCAST|M_MCAST))) 1004 m_freem(m); 1005 else 1006 icmp6_error(m, ICMP6_PARAM_PROB, 1007 ICMP6_PARAMPROB_OPTION, off); 1008 return (-1); 1009 } 1010 1011 m_freem(m); /* XXX: NOTREACHED */ 1012 return (-1); 1013 } 1014 1015 /* 1016 * Create the "control" list for this pcb. 1017 * 1018 * The routine will be called from upper layer handlers like tcp6_input(). 1019 * Thus the routine assumes that the caller (tcp6_input) have already 1020 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1021 * very first mbuf on the mbuf chain. 1022 * We may want to add some infinite loop prevention or sanity checks for safety. 1023 * (This applies only when you are using KAME mbuf chain restriction, i.e. 1024 * you are using IP6_EXTHDR_CHECK() not m_pulldown()) 1025 */ 1026 void 1027 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1028 { 1029 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1030 # define in6p_flags inp_flags 1031 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1032 1033 #ifdef SO_TIMESTAMP 1034 if (in6p->inp_socket->so_options & SO_TIMESTAMP) { 1035 struct timeval tv; 1036 1037 microtime(&tv); 1038 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1039 SCM_TIMESTAMP, SOL_SOCKET); 1040 if (*mp) 1041 mp = &(*mp)->m_next; 1042 } 1043 #endif 1044 1045 /* RFC 2292 sec. 5 */ 1046 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1047 struct in6_pktinfo pi6; 1048 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1049 if (IN6_IS_SCOPE_EMBED(&pi6.ipi6_addr)) 1050 pi6.ipi6_addr.s6_addr16[1] = 0; 1051 pi6.ipi6_ifindex = 1052 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1053 *mp = sbcreatecontrol((caddr_t) &pi6, 1054 sizeof(struct in6_pktinfo), 1055 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1056 if (*mp) 1057 mp = &(*mp)->m_next; 1058 } 1059 1060 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1061 int hlim = ip6->ip6_hlim & 0xff; 1062 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1063 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1064 if (*mp) 1065 mp = &(*mp)->m_next; 1066 } 1067 1068 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1069 u_int32_t flowinfo; 1070 int tclass; 1071 1072 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1073 flowinfo >>= 20; 1074 1075 tclass = flowinfo & 0xff; 1076 *mp = sbcreatecontrol((caddr_t)&tclass, sizeof(tclass), 1077 IPV6_TCLASS, IPPROTO_IPV6); 1078 if (*mp) 1079 mp = &(*mp)->m_next; 1080 } 1081 1082 /* 1083 * IPV6_HOPOPTS socket option. Recall that we required super-user 1084 * privilege for the option (see ip6_ctloutput), but it might be too 1085 * strict, since there might be some hop-by-hop options which can be 1086 * returned to normal user. 1087 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1088 */ 1089 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1090 /* 1091 * Check if a hop-by-hop options header is contatined in the 1092 * received packet, and if so, store the options as ancillary 1093 * data. Note that a hop-by-hop options header must be 1094 * just after the IPv6 header, which is assured through the 1095 * IPv6 input processing. 1096 */ 1097 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1098 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1099 struct ip6_hbh *hbh; 1100 int hbhlen = 0; 1101 struct mbuf *ext; 1102 1103 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1104 ip6->ip6_nxt); 1105 if (ext == NULL) { 1106 ip6stat.ip6s_tooshort++; 1107 return; 1108 } 1109 hbh = mtod(ext, struct ip6_hbh *); 1110 hbhlen = (hbh->ip6h_len + 1) << 3; 1111 if (hbhlen != ext->m_len) { 1112 m_freem(ext); 1113 ip6stat.ip6s_tooshort++; 1114 return; 1115 } 1116 1117 /* 1118 * XXX: We copy the whole header even if a 1119 * jumbo payload option is included, the option which 1120 * is to be removed before returning according to 1121 * RFC2292. 1122 * Note: this constraint is removed in RFC3542. 1123 */ 1124 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1125 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1126 IPPROTO_IPV6); 1127 if (*mp) 1128 mp = &(*mp)->m_next; 1129 m_freem(ext); 1130 } 1131 } 1132 1133 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1134 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1135 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1136 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1137 1138 /* 1139 * Search for destination options headers or routing 1140 * header(s) through the header chain, and stores each 1141 * header as ancillary data. 1142 * Note that the order of the headers remains in 1143 * the chain of ancillary data. 1144 */ 1145 while (1) { /* is explicit loop prevention necessary? */ 1146 struct ip6_ext *ip6e = NULL; 1147 int elen; 1148 struct mbuf *ext = NULL; 1149 1150 /* 1151 * if it is not an extension header, don't try to 1152 * pull it from the chain. 1153 */ 1154 switch (nxt) { 1155 case IPPROTO_DSTOPTS: 1156 case IPPROTO_ROUTING: 1157 case IPPROTO_HOPOPTS: 1158 case IPPROTO_AH: /* is it possible? */ 1159 break; 1160 default: 1161 goto loopend; 1162 } 1163 1164 ext = ip6_pullexthdr(m, off, nxt); 1165 if (ext == NULL) { 1166 ip6stat.ip6s_tooshort++; 1167 return; 1168 } 1169 ip6e = mtod(ext, struct ip6_ext *); 1170 if (nxt == IPPROTO_AH) 1171 elen = (ip6e->ip6e_len + 2) << 2; 1172 else 1173 elen = (ip6e->ip6e_len + 1) << 3; 1174 if (elen != ext->m_len) { 1175 m_freem(ext); 1176 ip6stat.ip6s_tooshort++; 1177 return; 1178 } 1179 1180 switch (nxt) { 1181 case IPPROTO_DSTOPTS: 1182 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1183 break; 1184 1185 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1186 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1187 IPPROTO_IPV6); 1188 if (*mp) 1189 mp = &(*mp)->m_next; 1190 break; 1191 1192 case IPPROTO_ROUTING: 1193 if (!(in6p->in6p_flags & IN6P_RTHDR)) 1194 break; 1195 1196 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1197 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1198 IPPROTO_IPV6); 1199 if (*mp) 1200 mp = &(*mp)->m_next; 1201 break; 1202 1203 case IPPROTO_HOPOPTS: 1204 case IPPROTO_AH: /* is it possible? */ 1205 break; 1206 1207 default: 1208 /* 1209 * other cases have been filtered in the above. 1210 * none will visit this case. here we supply 1211 * the code just in case (nxt overwritten or 1212 * other cases). 1213 */ 1214 m_freem(ext); 1215 goto loopend; 1216 1217 } 1218 1219 /* proceed with the next header. */ 1220 off += elen; 1221 nxt = ip6e->ip6e_nxt; 1222 ip6e = NULL; 1223 m_freem(ext); 1224 ext = NULL; 1225 } 1226 loopend: 1227 ; 1228 } 1229 # undef in6p_flags 1230 } 1231 1232 /* 1233 * pull single extension header from mbuf chain. returns single mbuf that 1234 * contains the result, or NULL on error. 1235 */ 1236 struct mbuf * 1237 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1238 { 1239 struct ip6_ext ip6e; 1240 size_t elen; 1241 struct mbuf *n; 1242 1243 #ifdef DIAGNOSTIC 1244 switch (nxt) { 1245 case IPPROTO_DSTOPTS: 1246 case IPPROTO_ROUTING: 1247 case IPPROTO_HOPOPTS: 1248 case IPPROTO_AH: /* is it possible? */ 1249 break; 1250 default: 1251 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1252 } 1253 #endif 1254 1255 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1256 if (nxt == IPPROTO_AH) 1257 elen = (ip6e.ip6e_len + 2) << 2; 1258 else 1259 elen = (ip6e.ip6e_len + 1) << 3; 1260 1261 MGET(n, M_DONTWAIT, MT_DATA); 1262 if (n && elen >= MLEN) { 1263 MCLGET(n, M_DONTWAIT); 1264 if ((n->m_flags & M_EXT) == 0) { 1265 m_free(n); 1266 n = NULL; 1267 } 1268 } 1269 if (!n) 1270 return NULL; 1271 1272 n->m_len = 0; 1273 if (elen >= M_TRAILINGSPACE(n)) { 1274 m_free(n); 1275 return NULL; 1276 } 1277 1278 m_copydata(m, off, elen, mtod(n, caddr_t)); 1279 n->m_len = elen; 1280 return n; 1281 } 1282 1283 /* 1284 * Get pointer to the previous header followed by the header 1285 * currently processed. 1286 * XXX: This function supposes that 1287 * M includes all headers, 1288 * the next header field and the header length field of each header 1289 * are valid, and 1290 * the sum of each header length equals to OFF. 1291 * Because of these assumptions, this function must be called very 1292 * carefully. Moreover, it will not be used in the near future when 1293 * we develop `neater' mechanism to process extension headers. 1294 */ 1295 u_int8_t * 1296 ip6_get_prevhdr(struct mbuf *m, int off) 1297 { 1298 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1299 1300 if (off == sizeof(struct ip6_hdr)) 1301 return (&ip6->ip6_nxt); 1302 else { 1303 int len, nxt; 1304 struct ip6_ext *ip6e = NULL; 1305 1306 nxt = ip6->ip6_nxt; 1307 len = sizeof(struct ip6_hdr); 1308 while (len < off) { 1309 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1310 1311 switch (nxt) { 1312 case IPPROTO_FRAGMENT: 1313 len += sizeof(struct ip6_frag); 1314 break; 1315 case IPPROTO_AH: 1316 len += (ip6e->ip6e_len + 2) << 2; 1317 break; 1318 default: 1319 len += (ip6e->ip6e_len + 1) << 3; 1320 break; 1321 } 1322 nxt = ip6e->ip6e_nxt; 1323 } 1324 if (ip6e) 1325 return (&ip6e->ip6e_nxt); 1326 else 1327 return NULL; 1328 } 1329 } 1330 1331 /* 1332 * get next header offset. m will be retained. 1333 */ 1334 int 1335 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1336 { 1337 struct ip6_hdr ip6; 1338 struct ip6_ext ip6e; 1339 struct ip6_frag fh; 1340 1341 /* just in case */ 1342 if (m == NULL) 1343 panic("ip6_nexthdr: m == NULL"); 1344 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1345 return -1; 1346 1347 switch (proto) { 1348 case IPPROTO_IPV6: 1349 if (m->m_pkthdr.len < off + sizeof(ip6)) 1350 return -1; 1351 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1352 if (nxtp) 1353 *nxtp = ip6.ip6_nxt; 1354 off += sizeof(ip6); 1355 return off; 1356 1357 case IPPROTO_FRAGMENT: 1358 /* 1359 * terminate parsing if it is not the first fragment, 1360 * it does not make sense to parse through it. 1361 */ 1362 if (m->m_pkthdr.len < off + sizeof(fh)) 1363 return -1; 1364 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1365 if ((fh.ip6f_offlg & IP6F_OFF_MASK) != 0) 1366 return -1; 1367 if (nxtp) 1368 *nxtp = fh.ip6f_nxt; 1369 off += sizeof(struct ip6_frag); 1370 return off; 1371 1372 case IPPROTO_AH: 1373 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1374 return -1; 1375 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1376 if (nxtp) 1377 *nxtp = ip6e.ip6e_nxt; 1378 off += (ip6e.ip6e_len + 2) << 2; 1379 if (m->m_pkthdr.len < off) 1380 return -1; 1381 return off; 1382 1383 case IPPROTO_HOPOPTS: 1384 case IPPROTO_ROUTING: 1385 case IPPROTO_DSTOPTS: 1386 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1387 return -1; 1388 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1389 if (nxtp) 1390 *nxtp = ip6e.ip6e_nxt; 1391 off += (ip6e.ip6e_len + 1) << 3; 1392 if (m->m_pkthdr.len < off) 1393 return -1; 1394 return off; 1395 1396 case IPPROTO_NONE: 1397 case IPPROTO_ESP: 1398 case IPPROTO_IPCOMP: 1399 /* give up */ 1400 return -1; 1401 1402 default: 1403 return -1; 1404 } 1405 1406 return -1; 1407 } 1408 1409 /* 1410 * get offset for the last header in the chain. m will be kept untainted. 1411 */ 1412 int 1413 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1414 { 1415 int newoff; 1416 int nxt; 1417 1418 if (!nxtp) { 1419 nxt = -1; 1420 nxtp = &nxt; 1421 } 1422 while (1) { 1423 newoff = ip6_nexthdr(m, off, proto, nxtp); 1424 if (newoff < 0) 1425 return off; 1426 else if (newoff < off) 1427 return -1; /* invalid */ 1428 else if (newoff == off) 1429 return newoff; 1430 1431 off = newoff; 1432 proto = *nxtp; 1433 } 1434 } 1435 1436 /* 1437 * System control for IP6 1438 */ 1439 1440 u_char inet6ctlerrmap[PRC_NCMDS] = { 1441 0, 0, 0, 0, 1442 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1443 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1444 EMSGSIZE, EHOSTUNREACH, 0, 0, 1445 0, 0, 0, 0, 1446 ENOPROTOOPT 1447 }; 1448 1449 #include <uvm/uvm_extern.h> 1450 #include <sys/sysctl.h> 1451 1452 int *ipv6ctl_vars[IPV6CTL_MAXID] = IPV6CTL_VARS; 1453 1454 int 1455 ip6_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, 1456 void *newp, size_t newlen) 1457 { 1458 #ifdef MROUTING 1459 extern int ip6_mrtproto; 1460 extern struct mrt6stat mrt6stat; 1461 #endif 1462 1463 /* All sysctl names at this level are terminal. */ 1464 if (namelen != 1) 1465 return ENOTDIR; 1466 1467 switch (name[0]) { 1468 case IPV6CTL_KAME_VERSION: 1469 return sysctl_rdstring(oldp, oldlenp, newp, __KAME_VERSION); 1470 case IPV6CTL_V6ONLY: 1471 return sysctl_rdint(oldp, oldlenp, newp, ip6_v6only); 1472 case IPV6CTL_DAD_PENDING: 1473 return sysctl_rdint(oldp, oldlenp, newp, ip6_dad_pending); 1474 case IPV6CTL_STATS: 1475 if (newp != NULL) 1476 return (EPERM); 1477 return (sysctl_struct(oldp, oldlenp, newp, newlen, 1478 &ip6stat, sizeof(ip6stat))); 1479 case IPV6CTL_MRTSTATS: 1480 #ifdef MROUTING 1481 if (newp != NULL) 1482 return (EPERM); 1483 return (sysctl_struct(oldp, oldlenp, newp, newlen, 1484 &mrt6stat, sizeof(mrt6stat))); 1485 #else 1486 return (EOPNOTSUPP); 1487 #endif 1488 case IPV6CTL_MRTPROTO: 1489 #ifdef MROUTING 1490 return sysctl_rdint(oldp, oldlenp, newp, ip6_mrtproto); 1491 #else 1492 return (EOPNOTSUPP); 1493 #endif 1494 default: 1495 if (name[0] < IPV6CTL_MAXID) 1496 return (sysctl_int_arr(ipv6ctl_vars, name, namelen, 1497 oldp, oldlenp, newp, newlen)); 1498 return (EOPNOTSUPP); 1499 } 1500 /* NOTREACHED */ 1501 } 1502