1 /* $OpenBSD: ip6_input.c,v 1.87 2008/09/17 05:43:14 chl 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 #include <netinet/ip_icmp.h> 93 #endif /*INET*/ 94 95 #include <netinet/in_pcb.h> 96 #include <netinet6/in6_var.h> 97 #include <netinet/ip6.h> 98 #include <netinet6/ip6_var.h> 99 #include <netinet/icmp6.h> 100 #include <netinet6/in6_ifattach.h> 101 #include <netinet6/nd6.h> 102 103 #include <netinet6/ip6protosw.h> 104 105 #include "faith.h" 106 #include "gif.h" 107 #include "bpfilter.h" 108 109 #ifdef MROUTING 110 #include <netinet6/ip6_mroute.h> 111 #endif 112 113 #if NPF > 0 114 #include <net/pfvar.h> 115 #endif 116 117 #if NCARP > 0 118 #include <netinet/in_var.h> 119 #include <netinet/ip_carp.h> 120 #endif 121 122 extern struct domain inet6domain; 123 extern struct ip6protosw inet6sw[]; 124 125 u_char ip6_protox[IPPROTO_MAX]; 126 static int ip6qmaxlen = IFQ_MAXLEN; 127 struct in6_ifaddr *in6_ifaddr; 128 struct ifqueue ip6intrq; 129 130 int ip6_forward_srcrt; /* XXX */ 131 int ip6_sourcecheck; /* XXX */ 132 int ip6_sourcecheck_interval; /* XXX */ 133 134 struct ip6stat ip6stat; 135 136 static void ip6_init2(void *); 137 int ip6_check_rh0hdr(struct mbuf *); 138 139 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 140 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 141 142 /* 143 * IP6 initialization: fill in IP6 protocol switch table. 144 * All protocols not implemented in kernel go to raw IP6 protocol handler. 145 */ 146 void 147 ip6_init() 148 { 149 struct ip6protosw *pr; 150 int i; 151 152 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 153 if (pr == 0) 154 panic("ip6_init"); 155 for (i = 0; i < IPPROTO_MAX; i++) 156 ip6_protox[i] = pr - inet6sw; 157 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 158 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 159 if (pr->pr_domain->dom_family == PF_INET6 && 160 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 161 ip6_protox[pr->pr_protocol] = pr - inet6sw; 162 ip6intrq.ifq_maxlen = ip6qmaxlen; 163 ip6_randomid_init(); 164 nd6_init(); 165 frag6_init(); 166 ip6_init2((void *)0); 167 } 168 169 static void 170 ip6_init2(void *dummy) 171 { 172 173 /* nd6_timer_init */ 174 bzero(&nd6_timer_ch, sizeof(nd6_timer_ch)); 175 timeout_set(&nd6_timer_ch, nd6_timer, NULL); 176 timeout_add(&nd6_timer_ch, hz); 177 } 178 179 /* 180 * IP6 input interrupt handling. Just pass the packet to ip6_input. 181 */ 182 void 183 ip6intr() 184 { 185 int s; 186 struct mbuf *m; 187 188 for (;;) { 189 s = splnet(); 190 IF_DEQUEUE(&ip6intrq, m); 191 splx(s); 192 if (m == NULL) 193 return; 194 ip6_input(m); 195 } 196 } 197 198 extern struct route_in6 ip6_forward_rt; 199 extern int ip6_forward_rtableid; 200 201 void 202 ip6_input(struct mbuf *m) 203 { 204 struct ip6_hdr *ip6; 205 int off = sizeof(struct ip6_hdr), nest; 206 u_int32_t plen; 207 u_int32_t rtalert = ~0; 208 int nxt, ours = 0; 209 struct ifnet *deliverifp = NULL; 210 #if NPF > 0 211 struct in6_addr odst; 212 #endif 213 int srcrt = 0, rtableid = 0; 214 215 /* 216 * mbuf statistics by kazu 217 */ 218 if (m->m_flags & M_EXT) { 219 if (m->m_next) 220 ip6stat.ip6s_mext2m++; 221 else 222 ip6stat.ip6s_mext1++; 223 } else { 224 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 225 if (m->m_next) { 226 if (m->m_flags & M_LOOP) { 227 ip6stat.ip6s_m2m[lo0ifp->if_index]++; /*XXX*/ 228 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 229 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 230 else 231 ip6stat.ip6s_m2m[0]++; 232 } else 233 ip6stat.ip6s_m1++; 234 #undef M2MMAX 235 } 236 237 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 238 ip6stat.ip6s_total++; 239 240 if (m->m_len < sizeof(struct ip6_hdr)) { 241 struct ifnet *inifp; 242 inifp = m->m_pkthdr.rcvif; 243 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 244 ip6stat.ip6s_toosmall++; 245 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 246 return; 247 } 248 } 249 250 ip6 = mtod(m, struct ip6_hdr *); 251 252 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 253 ip6stat.ip6s_badvers++; 254 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 255 goto bad; 256 } 257 258 #if NCARP > 0 259 if (m->m_pkthdr.rcvif->if_type == IFT_CARP && 260 ip6->ip6_nxt != IPPROTO_ICMPV6 && 261 carp_lsdrop(m, AF_INET6, ip6->ip6_src.s6_addr32, 262 ip6->ip6_dst.s6_addr32)) 263 goto bad; 264 #endif 265 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 266 267 /* 268 * Check against address spoofing/corruption. 269 */ 270 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 271 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 272 /* 273 * XXX: "badscope" is not very suitable for a multicast source. 274 */ 275 ip6stat.ip6s_badscope++; 276 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 277 goto bad; 278 } 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)) { 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_OPTION, 0); 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_test6(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 if (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) { 353 ours = 1; 354 deliverifp = m->m_pkthdr.rcvif; 355 goto hbhcheck; 356 } else { 357 ip6stat.ip6s_badscope++; 358 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 359 goto bad; 360 } 361 } 362 363 /* drop packets if interface ID portion is already filled */ 364 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 365 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src) && 366 ip6->ip6_src.s6_addr16[1]) { 367 ip6stat.ip6s_badscope++; 368 goto bad; 369 } 370 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst) && 371 ip6->ip6_dst.s6_addr16[1]) { 372 ip6stat.ip6s_badscope++; 373 goto bad; 374 } 375 } 376 377 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) 378 ip6->ip6_src.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 379 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) 380 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 381 382 /* 383 * We use rt->rt_ifp to determine if the address is ours or not. 384 * If rt_ifp is lo0, the address is ours. 385 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 386 * so any address under fe80::%lo0/64 will be mistakenly considered 387 * local. The special case is supplied to handle the case properly 388 * by actually looking at interface addresses 389 * (using in6ifa_ifpwithaddr). 390 */ 391 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 392 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 393 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 394 icmp6_error(m, ICMP6_DST_UNREACH, 395 ICMP6_DST_UNREACH_ADDR, 0); 396 /* m is already freed */ 397 return; 398 } 399 400 ours = 1; 401 deliverifp = m->m_pkthdr.rcvif; 402 goto hbhcheck; 403 } 404 405 if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) { 406 ours = 1; 407 deliverifp = m->m_pkthdr.rcvif; 408 goto hbhcheck; 409 } 410 411 /* 412 * Multicast check 413 */ 414 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 415 struct in6_multi *in6m = 0; 416 417 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 418 /* 419 * See if we belong to the destination multicast group on the 420 * arrival interface. 421 */ 422 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 423 if (in6m) 424 ours = 1; 425 #ifdef MROUTING 426 else if (!ip6_mforwarding || !ip6_mrouter) 427 #else 428 else 429 #endif 430 { 431 ip6stat.ip6s_notmember++; 432 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 433 ip6stat.ip6s_cantforward++; 434 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 435 goto bad; 436 } 437 deliverifp = m->m_pkthdr.rcvif; 438 goto hbhcheck; 439 } 440 441 #if NPF > 0 442 rtableid = m->m_pkthdr.pf.rtableid; 443 #endif 444 445 /* 446 * Unicast check 447 */ 448 if (ip6_forward_rt.ro_rt != NULL && 449 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 450 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 451 &ip6_forward_rt.ro_dst.sin6_addr) && 452 rtableid == ip6_forward_rtableid) 453 ip6stat.ip6s_forward_cachehit++; 454 else { 455 if (ip6_forward_rt.ro_rt) { 456 /* route is down or destination is different */ 457 ip6stat.ip6s_forward_cachemiss++; 458 RTFREE(ip6_forward_rt.ro_rt); 459 ip6_forward_rt.ro_rt = 0; 460 } 461 462 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 463 ip6_forward_rt.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 464 ip6_forward_rt.ro_dst.sin6_family = AF_INET6; 465 ip6_forward_rt.ro_dst.sin6_addr = ip6->ip6_dst; 466 ip6_forward_rtableid = rtableid; 467 468 rtalloc_mpath((struct route *)&ip6_forward_rt, 469 &ip6->ip6_src.s6_addr32[0], rtableid); 470 } 471 472 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 473 474 /* 475 * Accept the packet if the forwarding interface to the destination 476 * according to the routing table is the loopback interface, 477 * unless the associated route has a gateway. 478 * Note that this approach causes to accept a packet if there is a 479 * route to the loopback interface for the destination of the packet. 480 * But we think it's even useful in some situations, e.g. when using 481 * a special daemon which wants to intercept the packet. 482 */ 483 if (ip6_forward_rt.ro_rt && 484 (ip6_forward_rt.ro_rt->rt_flags & 485 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 486 #if 0 487 /* 488 * The check below is redundant since the comparison of 489 * the destination and the key of the rtentry has 490 * already done through looking up the routing table. 491 */ 492 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 493 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) && 494 #endif 495 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 496 struct in6_ifaddr *ia6 = 497 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 498 if (ia6->ia6_flags & IN6_IFF_ANYCAST) 499 m->m_flags |= M_ANYCAST6; 500 /* 501 * packets to a tentative, duplicated, or somehow invalid 502 * address must not be accepted. 503 */ 504 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 505 /* this address is ready */ 506 ours = 1; 507 deliverifp = ia6->ia_ifp; /* correct? */ 508 goto hbhcheck; 509 } else { 510 /* address is not ready, so discard the packet. */ 511 nd6log((LOG_INFO, 512 "ip6_input: packet to an unready address %s->%s\n", 513 ip6_sprintf(&ip6->ip6_src), 514 ip6_sprintf(&ip6->ip6_dst))); 515 516 goto bad; 517 } 518 } 519 520 /* 521 * FAITH (Firewall Aided Internet Translator) 522 */ 523 #if defined(NFAITH) && 0 < NFAITH 524 if (ip6_keepfaith) { 525 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 526 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 527 /* XXX do we need more sanity checks? */ 528 ours = 1; 529 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /*faith*/ 530 goto hbhcheck; 531 } 532 } 533 #endif 534 535 #if 0 536 { 537 /* 538 * Last resort: check in6_ifaddr for incoming interface. 539 * The code is here until I update the "goto ours hack" code above 540 * working right. 541 */ 542 struct ifaddr *ifa; 543 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) { 544 if (ifa->ifa_addr == NULL) 545 continue; /* just for safety */ 546 if (ifa->ifa_addr->sa_family != AF_INET6) 547 continue; 548 if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ip6->ip6_dst)) { 549 ours = 1; 550 deliverifp = ifa->ifa_ifp; 551 goto hbhcheck; 552 } 553 } 554 } 555 #endif 556 557 #if NCARP > 0 558 if (m->m_pkthdr.rcvif->if_type == IFT_CARP && 559 ip6->ip6_nxt == IPPROTO_ICMPV6 && 560 carp_lsdrop(m, AF_INET6, ip6->ip6_src.s6_addr32, 561 ip6->ip6_dst.s6_addr32)) 562 goto bad; 563 #endif 564 /* 565 * Now there is no reason to process the packet if it's not our own 566 * and we're not a router. 567 */ 568 if (!ip6_forwarding) { 569 ip6stat.ip6s_cantforward++; 570 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 571 goto bad; 572 } 573 574 hbhcheck: 575 /* 576 * Process Hop-by-Hop options header if it's contained. 577 * m may be modified in ip6_hopopts_input(). 578 * If a JumboPayload option is included, plen will also be modified. 579 */ 580 plen = (u_int32_t)ntohs(ip6->ip6_plen); 581 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 582 struct ip6_hbh *hbh; 583 584 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 585 #if 0 /*touches NULL pointer*/ 586 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 587 #endif 588 return; /* m have already been freed */ 589 } 590 591 /* adjust pointer */ 592 ip6 = mtod(m, struct ip6_hdr *); 593 594 /* 595 * if the payload length field is 0 and the next header field 596 * indicates Hop-by-Hop Options header, then a Jumbo Payload 597 * option MUST be included. 598 */ 599 if (ip6->ip6_plen == 0 && plen == 0) { 600 /* 601 * Note that if a valid jumbo payload option is 602 * contained, ip6_hoptops_input() must set a valid 603 * (non-zero) payload length to the variable plen. 604 */ 605 ip6stat.ip6s_badoptions++; 606 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 607 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 608 icmp6_error(m, ICMP6_PARAM_PROB, 609 ICMP6_PARAMPROB_HEADER, 610 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 611 return; 612 } 613 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 614 sizeof(struct ip6_hbh)); 615 if (hbh == NULL) { 616 ip6stat.ip6s_tooshort++; 617 return; 618 } 619 nxt = hbh->ip6h_nxt; 620 621 /* 622 * accept the packet if a router alert option is included 623 * and we act as an IPv6 router. 624 */ 625 if (rtalert != ~0 && ip6_forwarding) 626 ours = 1; 627 } else 628 nxt = ip6->ip6_nxt; 629 630 /* 631 * Check that the amount of data in the buffers 632 * is as at least much as the IPv6 header would have us expect. 633 * Trim mbufs if longer than we expect. 634 * Drop packet if shorter than we expect. 635 */ 636 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 637 ip6stat.ip6s_tooshort++; 638 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 639 goto bad; 640 } 641 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 642 if (m->m_len == m->m_pkthdr.len) { 643 m->m_len = sizeof(struct ip6_hdr) + plen; 644 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 645 } else 646 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 647 } 648 649 /* 650 * Forward if desirable. 651 */ 652 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 653 /* 654 * If we are acting as a multicast router, all 655 * incoming multicast packets are passed to the 656 * kernel-level multicast forwarding function. 657 * The packet is returned (relatively) intact; if 658 * ip6_mforward() returns a non-zero value, the packet 659 * must be discarded, else it may be accepted below. 660 */ 661 #ifdef MROUTING 662 if (ip6_mforwarding && ip6_mrouter && 663 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 664 ip6stat.ip6s_cantforward++; 665 m_freem(m); 666 return; 667 } 668 #endif 669 if (!ours) { 670 m_freem(m); 671 return; 672 } 673 } else if (!ours) { 674 ip6_forward(m, srcrt); 675 return; 676 } 677 678 ip6 = mtod(m, struct ip6_hdr *); 679 680 /* 681 * Malicious party may be able to use IPv4 mapped addr to confuse 682 * tcp/udp stack and bypass security checks (act as if it was from 683 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 684 * 685 * For SIIT end node behavior, you may want to disable the check. 686 * However, you will become vulnerable to attacks using IPv4 mapped 687 * source. 688 */ 689 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 690 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 691 ip6stat.ip6s_badscope++; 692 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 693 goto bad; 694 } 695 696 /* 697 * Tell launch routine the next header 698 */ 699 ip6stat.ip6s_delivered++; 700 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 701 nest = 0; 702 703 while (nxt != IPPROTO_DONE) { 704 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 705 ip6stat.ip6s_toomanyhdr++; 706 goto bad; 707 } 708 709 /* 710 * protection against faulty packet - there should be 711 * more sanity checks in header chain processing. 712 */ 713 if (m->m_pkthdr.len < off) { 714 ip6stat.ip6s_tooshort++; 715 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 716 goto bad; 717 } 718 719 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 720 } 721 return; 722 bad: 723 m_freem(m); 724 } 725 726 727 /* scan packet for RH0 routing header. Mostly stolen from pf.c:pf_test6() */ 728 int 729 ip6_check_rh0hdr(struct mbuf *m) 730 { 731 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 732 struct ip6_rthdr rthdr; 733 struct ip6_ext opt6; 734 u_int8_t proto = ip6->ip6_nxt; 735 int done = 0, lim, off, rh_cnt = 0; 736 737 off = ((caddr_t)ip6 - m->m_data) + sizeof(struct ip6_hdr); 738 lim = min(m->m_pkthdr.len, ntohs(ip6->ip6_plen) + sizeof(*ip6)); 739 do { 740 switch (proto) { 741 case IPPROTO_ROUTING: 742 if (rh_cnt++) { 743 /* more then one rh header present */ 744 return (1); 745 } 746 747 if (off + sizeof(rthdr) > lim) { 748 /* packet to short to make sense */ 749 return (1); 750 } 751 752 m_copydata(m, off, sizeof(rthdr), (caddr_t)&rthdr); 753 754 if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) 755 return (1); 756 757 off += (rthdr.ip6r_len + 1) * 8; 758 proto = rthdr.ip6r_nxt; 759 break; 760 case IPPROTO_AH: 761 case IPPROTO_HOPOPTS: 762 case IPPROTO_DSTOPTS: 763 /* get next header and header length */ 764 if (off + sizeof(opt6) > lim) { 765 /* 766 * Packet to short to make sense, we could 767 * reject the packet but as a router we 768 * should not do that so forward it. 769 */ 770 return (0); 771 } 772 773 m_copydata(m, off, sizeof(opt6), (caddr_t)&opt6); 774 775 if (proto == IPPROTO_AH) 776 off += (opt6.ip6e_len + 2) * 4; 777 else 778 off += (opt6.ip6e_len + 1) * 8; 779 proto = opt6.ip6e_nxt; 780 break; 781 case IPPROTO_FRAGMENT: 782 default: 783 /* end of header stack */ 784 done = 1; 785 break; 786 } 787 } while (!done); 788 789 return (0); 790 } 791 792 /* 793 * Hop-by-Hop options header processing. If a valid jumbo payload option is 794 * included, the real payload length will be stored in plenp. 795 * 796 * rtalertp - XXX: should be stored in a more smart way 797 */ 798 static int 799 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, struct mbuf **mp, 800 int *offp) 801 { 802 struct mbuf *m = *mp; 803 int off = *offp, hbhlen; 804 struct ip6_hbh *hbh; 805 806 /* validation of the length of the header */ 807 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 808 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 809 if (hbh == NULL) { 810 ip6stat.ip6s_tooshort++; 811 return -1; 812 } 813 hbhlen = (hbh->ip6h_len + 1) << 3; 814 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 815 hbhlen); 816 if (hbh == NULL) { 817 ip6stat.ip6s_tooshort++; 818 return -1; 819 } 820 off += hbhlen; 821 hbhlen -= sizeof(struct ip6_hbh); 822 823 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 824 hbhlen, rtalertp, plenp) < 0) 825 return (-1); 826 827 *offp = off; 828 *mp = m; 829 return (0); 830 } 831 832 /* 833 * Search header for all Hop-by-hop options and process each option. 834 * This function is separate from ip6_hopopts_input() in order to 835 * handle a case where the sending node itself process its hop-by-hop 836 * options header. In such a case, the function is called from ip6_output(). 837 * 838 * The function assumes that hbh header is located right after the IPv6 header 839 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 840 * opthead + hbhlen is located in continuous memory region. 841 */ 842 int 843 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 844 u_int32_t *rtalertp, u_int32_t *plenp) 845 { 846 struct ip6_hdr *ip6; 847 int optlen = 0; 848 u_int8_t *opt = opthead; 849 u_int16_t rtalert_val; 850 u_int32_t jumboplen; 851 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 852 853 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 854 switch (*opt) { 855 case IP6OPT_PAD1: 856 optlen = 1; 857 break; 858 case IP6OPT_PADN: 859 if (hbhlen < IP6OPT_MINLEN) { 860 ip6stat.ip6s_toosmall++; 861 goto bad; 862 } 863 optlen = *(opt + 1) + 2; 864 break; 865 case IP6OPT_ROUTER_ALERT: 866 /* XXX may need check for alignment */ 867 if (hbhlen < IP6OPT_RTALERT_LEN) { 868 ip6stat.ip6s_toosmall++; 869 goto bad; 870 } 871 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 872 /* XXX stat */ 873 icmp6_error(m, ICMP6_PARAM_PROB, 874 ICMP6_PARAMPROB_HEADER, 875 erroff + opt + 1 - opthead); 876 return (-1); 877 } 878 optlen = IP6OPT_RTALERT_LEN; 879 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 880 *rtalertp = ntohs(rtalert_val); 881 break; 882 case IP6OPT_JUMBO: 883 /* XXX may need check for alignment */ 884 if (hbhlen < IP6OPT_JUMBO_LEN) { 885 ip6stat.ip6s_toosmall++; 886 goto bad; 887 } 888 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 889 /* XXX stat */ 890 icmp6_error(m, ICMP6_PARAM_PROB, 891 ICMP6_PARAMPROB_HEADER, 892 erroff + opt + 1 - opthead); 893 return (-1); 894 } 895 optlen = IP6OPT_JUMBO_LEN; 896 897 /* 898 * IPv6 packets that have non 0 payload length 899 * must not contain a jumbo payload option. 900 */ 901 ip6 = mtod(m, struct ip6_hdr *); 902 if (ip6->ip6_plen) { 903 ip6stat.ip6s_badoptions++; 904 icmp6_error(m, ICMP6_PARAM_PROB, 905 ICMP6_PARAMPROB_HEADER, 906 erroff + opt - opthead); 907 return (-1); 908 } 909 910 /* 911 * We may see jumbolen in unaligned location, so 912 * we'd need to perform bcopy(). 913 */ 914 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 915 jumboplen = (u_int32_t)htonl(jumboplen); 916 917 #if 1 918 /* 919 * if there are multiple jumbo payload options, 920 * *plenp will be non-zero and the packet will be 921 * rejected. 922 * the behavior may need some debate in ipngwg - 923 * multiple options does not make sense, however, 924 * there's no explicit mention in specification. 925 */ 926 if (*plenp != 0) { 927 ip6stat.ip6s_badoptions++; 928 icmp6_error(m, ICMP6_PARAM_PROB, 929 ICMP6_PARAMPROB_HEADER, 930 erroff + opt + 2 - opthead); 931 return (-1); 932 } 933 #endif 934 935 /* 936 * jumbo payload length must be larger than 65535. 937 */ 938 if (jumboplen <= IPV6_MAXPACKET) { 939 ip6stat.ip6s_badoptions++; 940 icmp6_error(m, ICMP6_PARAM_PROB, 941 ICMP6_PARAMPROB_HEADER, 942 erroff + opt + 2 - opthead); 943 return (-1); 944 } 945 *plenp = jumboplen; 946 947 break; 948 default: /* unknown option */ 949 if (hbhlen < IP6OPT_MINLEN) { 950 ip6stat.ip6s_toosmall++; 951 goto bad; 952 } 953 optlen = ip6_unknown_opt(opt, m, 954 erroff + opt - opthead); 955 if (optlen == -1) 956 return (-1); 957 optlen += 2; 958 break; 959 } 960 } 961 962 return (0); 963 964 bad: 965 m_freem(m); 966 return (-1); 967 } 968 969 /* 970 * Unknown option processing. 971 * The third argument `off' is the offset from the IPv6 header to the option, 972 * which is necessary if the IPv6 header the and option header and IPv6 header 973 * is not continuous in order to return an ICMPv6 error. 974 */ 975 int 976 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 977 { 978 struct ip6_hdr *ip6; 979 980 switch (IP6OPT_TYPE(*optp)) { 981 case IP6OPT_TYPE_SKIP: /* ignore the option */ 982 return ((int)*(optp + 1)); 983 case IP6OPT_TYPE_DISCARD: /* silently discard */ 984 m_freem(m); 985 return (-1); 986 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 987 ip6stat.ip6s_badoptions++; 988 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 989 return (-1); 990 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 991 ip6stat.ip6s_badoptions++; 992 ip6 = mtod(m, struct ip6_hdr *); 993 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 994 (m->m_flags & (M_BCAST|M_MCAST))) 995 m_freem(m); 996 else 997 icmp6_error(m, ICMP6_PARAM_PROB, 998 ICMP6_PARAMPROB_OPTION, off); 999 return (-1); 1000 } 1001 1002 m_freem(m); /* XXX: NOTREACHED */ 1003 return (-1); 1004 } 1005 1006 /* 1007 * Create the "control" list for this pcb. 1008 * 1009 * The routine will be called from upper layer handlers like tcp6_input(). 1010 * Thus the routine assumes that the caller (tcp6_input) have already 1011 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1012 * very first mbuf on the mbuf chain. 1013 * We may want to add some infinite loop prevention or sanity checks for safety. 1014 * (This applies only when you are using KAME mbuf chain restriction, i.e. 1015 * you are using IP6_EXTHDR_CHECK() not m_pulldown()) 1016 */ 1017 void 1018 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1019 { 1020 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1021 # define in6p_flags inp_flags 1022 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1023 1024 #ifdef SO_TIMESTAMP 1025 if (in6p->inp_socket->so_options & SO_TIMESTAMP) { 1026 struct timeval tv; 1027 1028 microtime(&tv); 1029 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1030 SCM_TIMESTAMP, SOL_SOCKET); 1031 if (*mp) 1032 mp = &(*mp)->m_next; 1033 } 1034 #endif 1035 1036 /* RFC 2292 sec. 5 */ 1037 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1038 struct in6_pktinfo pi6; 1039 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1040 if (IN6_IS_SCOPE_EMBED(&pi6.ipi6_addr)) 1041 pi6.ipi6_addr.s6_addr16[1] = 0; 1042 pi6.ipi6_ifindex = 1043 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1044 *mp = sbcreatecontrol((caddr_t) &pi6, 1045 sizeof(struct in6_pktinfo), 1046 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1047 if (*mp) 1048 mp = &(*mp)->m_next; 1049 } 1050 1051 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1052 int hlim = ip6->ip6_hlim & 0xff; 1053 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1054 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1055 if (*mp) 1056 mp = &(*mp)->m_next; 1057 } 1058 1059 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1060 u_int32_t flowinfo; 1061 int tclass; 1062 1063 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1064 flowinfo >>= 20; 1065 1066 tclass = flowinfo & 0xff; 1067 *mp = sbcreatecontrol((caddr_t)&tclass, sizeof(tclass), 1068 IPV6_TCLASS, IPPROTO_IPV6); 1069 if (*mp) 1070 mp = &(*mp)->m_next; 1071 } 1072 1073 /* 1074 * IPV6_HOPOPTS socket option. Recall that we required super-user 1075 * privilege for the option (see ip6_ctloutput), but it might be too 1076 * strict, since there might be some hop-by-hop options which can be 1077 * returned to normal user. 1078 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1079 */ 1080 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1081 /* 1082 * Check if a hop-by-hop options header is contatined in the 1083 * received packet, and if so, store the options as ancillary 1084 * data. Note that a hop-by-hop options header must be 1085 * just after the IPv6 header, which is assured through the 1086 * IPv6 input processing. 1087 */ 1088 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1089 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1090 struct ip6_hbh *hbh; 1091 int hbhlen = 0; 1092 struct mbuf *ext; 1093 1094 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1095 ip6->ip6_nxt); 1096 if (ext == NULL) { 1097 ip6stat.ip6s_tooshort++; 1098 return; 1099 } 1100 hbh = mtod(ext, struct ip6_hbh *); 1101 hbhlen = (hbh->ip6h_len + 1) << 3; 1102 if (hbhlen != ext->m_len) { 1103 m_freem(ext); 1104 ip6stat.ip6s_tooshort++; 1105 return; 1106 } 1107 1108 /* 1109 * XXX: We copy the whole header even if a 1110 * jumbo payload option is included, the option which 1111 * is to be removed before returning according to 1112 * RFC2292. 1113 * Note: this constraint is removed in RFC3542. 1114 */ 1115 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1116 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1117 IPPROTO_IPV6); 1118 if (*mp) 1119 mp = &(*mp)->m_next; 1120 m_freem(ext); 1121 } 1122 } 1123 1124 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1125 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 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 = NULL; 1138 int elen; 1139 struct mbuf *ext = NULL; 1140 1141 /* 1142 * if it is not an extension header, don't try to 1143 * pull it from the chain. 1144 */ 1145 switch (nxt) { 1146 case IPPROTO_DSTOPTS: 1147 case IPPROTO_ROUTING: 1148 case IPPROTO_HOPOPTS: 1149 case IPPROTO_AH: /* is it possible? */ 1150 break; 1151 default: 1152 goto loopend; 1153 } 1154 1155 ext = ip6_pullexthdr(m, off, nxt); 1156 if (ext == NULL) { 1157 ip6stat.ip6s_tooshort++; 1158 return; 1159 } 1160 ip6e = mtod(ext, struct ip6_ext *); 1161 if (nxt == IPPROTO_AH) 1162 elen = (ip6e->ip6e_len + 2) << 2; 1163 else 1164 elen = (ip6e->ip6e_len + 1) << 3; 1165 if (elen != ext->m_len) { 1166 m_freem(ext); 1167 ip6stat.ip6s_tooshort++; 1168 return; 1169 } 1170 1171 switch (nxt) { 1172 case IPPROTO_DSTOPTS: 1173 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1174 break; 1175 1176 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1177 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1178 IPPROTO_IPV6); 1179 if (*mp) 1180 mp = &(*mp)->m_next; 1181 break; 1182 1183 case IPPROTO_ROUTING: 1184 if (!(in6p->in6p_flags & IN6P_RTHDR)) 1185 break; 1186 1187 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1188 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1189 IPPROTO_IPV6); 1190 if (*mp) 1191 mp = &(*mp)->m_next; 1192 break; 1193 1194 case IPPROTO_HOPOPTS: 1195 case IPPROTO_AH: /* is it possible? */ 1196 break; 1197 1198 default: 1199 /* 1200 * other cases have been filtered in the above. 1201 * none will visit this case. here we supply 1202 * the code just in case (nxt overwritten or 1203 * other cases). 1204 */ 1205 m_freem(ext); 1206 goto loopend; 1207 1208 } 1209 1210 /* proceed with the next header. */ 1211 off += elen; 1212 nxt = ip6e->ip6e_nxt; 1213 ip6e = NULL; 1214 m_freem(ext); 1215 ext = NULL; 1216 } 1217 loopend: 1218 ; 1219 } 1220 # undef in6p_flags 1221 } 1222 1223 /* 1224 * pull single extension header from mbuf chain. returns single mbuf that 1225 * contains the result, or NULL on error. 1226 */ 1227 static struct mbuf * 1228 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1229 { 1230 struct ip6_ext ip6e; 1231 size_t elen; 1232 struct mbuf *n; 1233 1234 #ifdef DIAGNOSTIC 1235 switch (nxt) { 1236 case IPPROTO_DSTOPTS: 1237 case IPPROTO_ROUTING: 1238 case IPPROTO_HOPOPTS: 1239 case IPPROTO_AH: /* is it possible? */ 1240 break; 1241 default: 1242 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1243 } 1244 #endif 1245 1246 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1247 if (nxt == IPPROTO_AH) 1248 elen = (ip6e.ip6e_len + 2) << 2; 1249 else 1250 elen = (ip6e.ip6e_len + 1) << 3; 1251 1252 MGET(n, M_DONTWAIT, MT_DATA); 1253 if (n && elen >= MLEN) { 1254 MCLGET(n, M_DONTWAIT); 1255 if ((n->m_flags & M_EXT) == 0) { 1256 m_free(n); 1257 n = NULL; 1258 } 1259 } 1260 if (!n) 1261 return NULL; 1262 1263 n->m_len = 0; 1264 if (elen >= M_TRAILINGSPACE(n)) { 1265 m_free(n); 1266 return NULL; 1267 } 1268 1269 m_copydata(m, off, elen, mtod(n, caddr_t)); 1270 n->m_len = elen; 1271 return n; 1272 } 1273 1274 /* 1275 * Get pointer to the previous header followed by the header 1276 * currently processed. 1277 * XXX: This function supposes that 1278 * M includes all headers, 1279 * the next header field and the header length field of each header 1280 * are valid, and 1281 * the sum of each header length equals to OFF. 1282 * Because of these assumptions, this function must be called very 1283 * carefully. Moreover, it will not be used in the near future when 1284 * we develop `neater' mechanism to process extension headers. 1285 */ 1286 u_int8_t * 1287 ip6_get_prevhdr(struct mbuf *m, int off) 1288 { 1289 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1290 1291 if (off == sizeof(struct ip6_hdr)) 1292 return (&ip6->ip6_nxt); 1293 else { 1294 int len, nxt; 1295 struct ip6_ext *ip6e = NULL; 1296 1297 nxt = ip6->ip6_nxt; 1298 len = sizeof(struct ip6_hdr); 1299 while (len < off) { 1300 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1301 1302 switch (nxt) { 1303 case IPPROTO_FRAGMENT: 1304 len += sizeof(struct ip6_frag); 1305 break; 1306 case IPPROTO_AH: 1307 len += (ip6e->ip6e_len + 2) << 2; 1308 break; 1309 default: 1310 len += (ip6e->ip6e_len + 1) << 3; 1311 break; 1312 } 1313 nxt = ip6e->ip6e_nxt; 1314 } 1315 if (ip6e) 1316 return (&ip6e->ip6e_nxt); 1317 else 1318 return NULL; 1319 } 1320 } 1321 1322 /* 1323 * get next header offset. m will be retained. 1324 */ 1325 int 1326 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1327 { 1328 struct ip6_hdr ip6; 1329 struct ip6_ext ip6e; 1330 struct ip6_frag fh; 1331 1332 /* just in case */ 1333 if (m == NULL) 1334 panic("ip6_nexthdr: m == NULL"); 1335 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1336 return -1; 1337 1338 switch (proto) { 1339 case IPPROTO_IPV6: 1340 if (m->m_pkthdr.len < off + sizeof(ip6)) 1341 return -1; 1342 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1343 if (nxtp) 1344 *nxtp = ip6.ip6_nxt; 1345 off += sizeof(ip6); 1346 return off; 1347 1348 case IPPROTO_FRAGMENT: 1349 /* 1350 * terminate parsing if it is not the first fragment, 1351 * it does not make sense to parse through it. 1352 */ 1353 if (m->m_pkthdr.len < off + sizeof(fh)) 1354 return -1; 1355 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1356 if ((fh.ip6f_offlg & IP6F_OFF_MASK) != 0) 1357 return -1; 1358 if (nxtp) 1359 *nxtp = fh.ip6f_nxt; 1360 off += sizeof(struct ip6_frag); 1361 return off; 1362 1363 case IPPROTO_AH: 1364 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1365 return -1; 1366 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1367 if (nxtp) 1368 *nxtp = ip6e.ip6e_nxt; 1369 off += (ip6e.ip6e_len + 2) << 2; 1370 if (m->m_pkthdr.len < off) 1371 return -1; 1372 return off; 1373 1374 case IPPROTO_HOPOPTS: 1375 case IPPROTO_ROUTING: 1376 case IPPROTO_DSTOPTS: 1377 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1378 return -1; 1379 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1380 if (nxtp) 1381 *nxtp = ip6e.ip6e_nxt; 1382 off += (ip6e.ip6e_len + 1) << 3; 1383 if (m->m_pkthdr.len < off) 1384 return -1; 1385 return off; 1386 1387 case IPPROTO_NONE: 1388 case IPPROTO_ESP: 1389 case IPPROTO_IPCOMP: 1390 /* give up */ 1391 return -1; 1392 1393 default: 1394 return -1; 1395 } 1396 1397 return -1; 1398 } 1399 1400 /* 1401 * get offset for the last header in the chain. m will be kept untainted. 1402 */ 1403 int 1404 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1405 { 1406 int newoff; 1407 int nxt; 1408 1409 if (!nxtp) { 1410 nxt = -1; 1411 nxtp = &nxt; 1412 } 1413 while (1) { 1414 newoff = ip6_nexthdr(m, off, proto, nxtp); 1415 if (newoff < 0) 1416 return off; 1417 else if (newoff < off) 1418 return -1; /* invalid */ 1419 else if (newoff == off) 1420 return newoff; 1421 1422 off = newoff; 1423 proto = *nxtp; 1424 } 1425 } 1426 1427 /* 1428 * System control for IP6 1429 */ 1430 1431 u_char inet6ctlerrmap[PRC_NCMDS] = { 1432 0, 0, 0, 0, 1433 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1434 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1435 EMSGSIZE, EHOSTUNREACH, 0, 0, 1436 0, 0, 0, 0, 1437 ENOPROTOOPT 1438 }; 1439 1440 #include <uvm/uvm_extern.h> 1441 #include <sys/sysctl.h> 1442 1443 int *ipv6ctl_vars[IPV6CTL_MAXID] = IPV6CTL_VARS; 1444 1445 int 1446 ip6_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, 1447 void *newp, size_t newlen) 1448 { 1449 #ifdef MROUTING 1450 extern int ip6_mrtproto; 1451 extern struct mrt6stat mrt6stat; 1452 #endif 1453 1454 /* All sysctl names at this level are terminal. */ 1455 if (namelen != 1) 1456 return ENOTDIR; 1457 1458 switch (name[0]) { 1459 case IPV6CTL_KAME_VERSION: 1460 return sysctl_rdstring(oldp, oldlenp, newp, __KAME_VERSION); 1461 case IPV6CTL_V6ONLY: 1462 return sysctl_rdint(oldp, oldlenp, newp, ip6_v6only); 1463 case IPV6CTL_STATS: 1464 if (newp != NULL) 1465 return (EPERM); 1466 return (sysctl_struct(oldp, oldlenp, newp, newlen, 1467 &ip6stat, sizeof(ip6stat))); 1468 case IPV6CTL_MRTSTATS: 1469 #ifdef MROUTING 1470 if (newp != NULL) 1471 return (EPERM); 1472 return (sysctl_struct(oldp, oldlenp, newp, newlen, 1473 &mrt6stat, sizeof(mrt6stat))); 1474 #else 1475 return (EOPNOTSUPP); 1476 #endif 1477 case IPV6CTL_MRTPROTO: 1478 #ifdef MROUTING 1479 return sysctl_rdint(oldp, oldlenp, newp, ip6_mrtproto); 1480 #else 1481 return (EOPNOTSUPP); 1482 #endif 1483 default: 1484 if (name[0] < IPV6CTL_MAXID) 1485 return (sysctl_int_arr(ipv6ctl_vars, name, namelen, 1486 oldp, oldlenp, newp, newlen)); 1487 return (EOPNOTSUPP); 1488 } 1489 /* NOTREACHED */ 1490 } 1491