1 /* $NetBSD: ip6_input.c,v 1.82 2006/01/23 23:01:40 yamt 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 <sys/cdefs.h> 65 __KERNEL_RCSID(0, "$NetBSD: ip6_input.c,v 1.82 2006/01/23 23:01:40 yamt Exp $"); 66 67 #include "opt_inet.h" 68 #include "opt_ipsec.h" 69 #include "opt_pfil_hooks.h" 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/malloc.h> 74 #include <sys/mbuf.h> 75 #include <sys/domain.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/errno.h> 80 #include <sys/time.h> 81 #include <sys/kernel.h> 82 #include <sys/syslog.h> 83 #include <sys/proc.h> 84 #include <sys/sysctl.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 #ifdef PFIL_HOOKS 92 #include <net/pfil.h> 93 #endif 94 95 #include <netinet/in.h> 96 #include <netinet/in_systm.h> 97 #ifdef INET 98 #include <netinet/ip.h> 99 #include <netinet/ip_icmp.h> 100 #endif /* INET */ 101 #include <netinet/ip6.h> 102 #include <netinet6/in6_var.h> 103 #include <netinet6/ip6_var.h> 104 #include <netinet6/in6_pcb.h> 105 #include <netinet/icmp6.h> 106 #include <netinet6/scope6_var.h> 107 #include <netinet6/in6_ifattach.h> 108 #include <netinet6/nd6.h> 109 110 #ifdef IPSEC 111 #include <netinet6/ipsec.h> 112 #endif 113 114 #include <netinet6/ip6protosw.h> 115 116 #include "faith.h" 117 #include "gif.h" 118 119 #if NGIF > 0 120 #include <netinet6/in6_gif.h> 121 #endif 122 123 #include <net/net_osdep.h> 124 125 extern struct domain inet6domain; 126 127 u_char ip6_protox[IPPROTO_MAX]; 128 static int ip6qmaxlen = IFQ_MAXLEN; 129 struct in6_ifaddr *in6_ifaddr; 130 struct ifqueue ip6intrq; 131 132 int ip6_forward_srcrt; /* XXX */ 133 int ip6_sourcecheck; /* XXX */ 134 int ip6_sourcecheck_interval; /* XXX */ 135 136 #ifdef PFIL_HOOKS 137 struct pfil_head inet6_pfil_hook; 138 #endif 139 140 struct ip6stat ip6stat; 141 142 static void ip6_init2 __P((void *)); 143 static struct m_tag *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 144 145 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 146 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 147 148 /* 149 * IP6 initialization: fill in IP6 protocol switch table. 150 * All protocols not implemented in kernel go to raw IP6 protocol handler. 151 */ 152 void 153 ip6_init() 154 { 155 const struct ip6protosw *pr; 156 int i; 157 158 pr = (const struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 159 if (pr == 0) 160 panic("ip6_init"); 161 for (i = 0; i < IPPROTO_MAX; i++) 162 ip6_protox[i] = pr - inet6sw; 163 for (pr = (const struct ip6protosw *)inet6domain.dom_protosw; 164 pr < (const struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 165 if (pr->pr_domain->dom_family == PF_INET6 && 166 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 167 ip6_protox[pr->pr_protocol] = pr - inet6sw; 168 ip6intrq.ifq_maxlen = ip6qmaxlen; 169 scope6_init(); 170 addrsel_policy_init(); 171 nd6_init(); 172 frag6_init(); 173 174 ip6_init2((void *)0); 175 176 #ifdef PFIL_HOOKS 177 /* Register our Packet Filter hook. */ 178 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 179 inet6_pfil_hook.ph_af = AF_INET6; 180 i = pfil_head_register(&inet6_pfil_hook); 181 if (i != 0) 182 printf("ip6_init: WARNING: unable to register pfil hook, " 183 "error %d\n", i); 184 #endif /* PFIL_HOOKS */ 185 } 186 187 static void 188 ip6_init2(dummy) 189 void *dummy; 190 { 191 192 /* nd6_timer_init */ 193 callout_init(&nd6_timer_ch); 194 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 195 } 196 197 /* 198 * IP6 input interrupt handling. Just pass the packet to ip6_input. 199 */ 200 void 201 ip6intr() 202 { 203 int s; 204 struct mbuf *m; 205 206 for (;;) { 207 s = splnet(); 208 IF_DEQUEUE(&ip6intrq, m); 209 splx(s); 210 if (m == 0) 211 return; 212 ip6_input(m); 213 } 214 } 215 216 extern struct route_in6 ip6_forward_rt; 217 218 void 219 ip6_input(m) 220 struct mbuf *m; 221 { 222 struct ip6_hdr *ip6; 223 int off = sizeof(struct ip6_hdr), nest; 224 u_int32_t plen; 225 u_int32_t rtalert = ~0; 226 int nxt, ours = 0; 227 struct ifnet *deliverifp = NULL; 228 int srcrt = 0; 229 230 #ifdef IPSEC 231 /* 232 * should the inner packet be considered authentic? 233 * see comment in ah4_input(). 234 */ 235 m->m_flags &= ~M_AUTHIPHDR; 236 m->m_flags &= ~M_AUTHIPDGM; 237 #endif 238 239 /* 240 * make sure we don't have onion peering information into m_tag. 241 */ 242 ip6_delaux(m); 243 244 /* 245 * mbuf statistics 246 */ 247 if (m->m_flags & M_EXT) { 248 if (m->m_next) 249 ip6stat.ip6s_mext2m++; 250 else 251 ip6stat.ip6s_mext1++; 252 } else { 253 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 254 if (m->m_next) { 255 if (m->m_flags & M_LOOP) { 256 ip6stat.ip6s_m2m[lo0ifp->if_index]++; /* XXX */ 257 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 258 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 259 else 260 ip6stat.ip6s_m2m[0]++; 261 } else 262 ip6stat.ip6s_m1++; 263 #undef M2MMAX 264 } 265 266 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 267 ip6stat.ip6s_total++; 268 269 /* 270 * If the IPv6 header is not aligned, slurp it up into a new 271 * mbuf with space for link headers, in the event we forward 272 * it. Otherwise, if it is aligned, make sure the entire base 273 * IPv6 header is in the first mbuf of the chain. 274 */ 275 if (IP6_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) { 276 struct ifnet *inifp = m->m_pkthdr.rcvif; 277 if ((m = m_copyup(m, sizeof(struct ip6_hdr), 278 (max_linkhdr + 3) & ~3)) == NULL) { 279 /* XXXJRT new stat, please */ 280 ip6stat.ip6s_toosmall++; 281 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 282 return; 283 } 284 } else if (__predict_false(m->m_len < sizeof(struct ip6_hdr))) { 285 struct ifnet *inifp = m->m_pkthdr.rcvif; 286 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 287 ip6stat.ip6s_toosmall++; 288 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 289 return; 290 } 291 } 292 293 ip6 = mtod(m, struct ip6_hdr *); 294 295 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 296 ip6stat.ip6s_badvers++; 297 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 298 goto bad; 299 } 300 301 #ifdef PFIL_HOOKS 302 /* 303 * Run through list of hooks for input packets. If there are any 304 * filters which require that additional packets in the flow are 305 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 306 * Note that filters must _never_ set this flag, as another filter 307 * in the list may have previously cleared it. 308 */ 309 /* 310 * let ipfilter look at packet on the wire, 311 * not the decapsulated packet. 312 */ 313 #ifdef IPSEC 314 if (!ipsec_getnhist(m)) 315 #else 316 if (1) 317 #endif 318 { 319 struct in6_addr odst; 320 321 odst = ip6->ip6_dst; 322 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, 323 PFIL_IN) != 0) 324 return; 325 if (m == NULL) 326 return; 327 ip6 = mtod(m, struct ip6_hdr *); 328 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 329 } 330 #endif /* PFIL_HOOKS */ 331 332 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 333 334 #ifdef ALTQ 335 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 336 /* packet is dropped by traffic conditioner */ 337 return; 338 } 339 #endif 340 341 /* 342 * Check against address spoofing/corruption. 343 */ 344 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 345 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 346 /* 347 * XXX: "badscope" is not very suitable for a multicast source. 348 */ 349 ip6stat.ip6s_badscope++; 350 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 351 goto bad; 352 } 353 /* 354 * The following check is not documented in specs. A malicious 355 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 356 * and bypass security checks (act as if it was from 127.0.0.1 by using 357 * IPv6 src ::ffff:127.0.0.1). Be cautious. 358 * 359 * This check chokes if we are in an SIIT cloud. As none of BSDs 360 * support IPv4-less kernel compilation, we cannot support SIIT 361 * environment at all. So, it makes more sense for us to reject any 362 * malicious packets for non-SIIT environment, than try to do a 363 * partial support for SIIT environment. 364 */ 365 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 366 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 367 ip6stat.ip6s_badscope++; 368 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 369 goto bad; 370 } 371 #if 0 372 /* 373 * Reject packets with IPv4 compatible addresses (auto tunnel). 374 * 375 * The code forbids auto tunnel relay case in RFC1933 (the check is 376 * stronger than RFC1933). We may want to re-enable it if mech-xx 377 * is revised to forbid relaying case. 378 */ 379 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 380 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 381 ip6stat.ip6s_badscope++; 382 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 383 goto bad; 384 } 385 #endif 386 387 /* 388 * Disambiguate address scope zones (if there is ambiguity). 389 * We first make sure that the original source or destination address 390 * is not in our internal form for scoped addresses. Such addresses 391 * are not necessarily invalid spec-wise, but we cannot accept them due 392 * to the usage conflict. 393 * in6_setscope() then also checks and rejects the cases where src or 394 * dst are the loopback address and the receiving interface 395 * is not loopback. 396 */ 397 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 398 ip6stat.ip6s_badscope++; /* XXX */ 399 goto bad; 400 } 401 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 402 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 403 ip6stat.ip6s_badscope++; 404 goto bad; 405 } 406 407 /* 408 * Multicast check 409 */ 410 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 411 struct in6_multi *in6m = 0; 412 413 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 414 /* 415 * See if we belong to the destination multicast group on the 416 * arrival interface. 417 */ 418 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 419 if (in6m) 420 ours = 1; 421 else if (!ip6_mrouter) { 422 ip6stat.ip6s_notmember++; 423 ip6stat.ip6s_cantforward++; 424 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 425 goto bad; 426 } 427 deliverifp = m->m_pkthdr.rcvif; 428 goto hbhcheck; 429 } 430 431 /* 432 * Unicast check 433 */ 434 if (ip6_forward_rt.ro_rt != NULL && 435 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 436 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 437 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 438 ip6stat.ip6s_forward_cachehit++; 439 else { 440 struct sockaddr_in6 *dst6; 441 442 if (ip6_forward_rt.ro_rt) { 443 /* route is down or destination is different */ 444 ip6stat.ip6s_forward_cachemiss++; 445 RTFREE(ip6_forward_rt.ro_rt); 446 ip6_forward_rt.ro_rt = 0; 447 } 448 449 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 450 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 451 dst6->sin6_len = sizeof(struct sockaddr_in6); 452 dst6->sin6_family = AF_INET6; 453 dst6->sin6_addr = ip6->ip6_dst; 454 455 rtalloc((struct route *)&ip6_forward_rt); 456 } 457 458 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 459 460 /* 461 * Accept the packet if the forwarding interface to the destination 462 * according to the routing table is the loopback interface, 463 * unless the associated route has a gateway. 464 * Note that this approach causes to accept a packet if there is a 465 * route to the loopback interface for the destination of the packet. 466 * But we think it's even useful in some situations, e.g. when using 467 * a special daemon which wants to intercept the packet. 468 */ 469 if (ip6_forward_rt.ro_rt && 470 (ip6_forward_rt.ro_rt->rt_flags & 471 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 472 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 473 #if 0 474 /* 475 * The check below is redundant since the comparison of 476 * the destination and the key of the rtentry has 477 * already done through looking up the routing table. 478 */ 479 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 480 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) && 481 #endif 482 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 483 struct in6_ifaddr *ia6 = 484 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 485 if (ia6->ia6_flags & IN6_IFF_ANYCAST) 486 m->m_flags |= M_ANYCAST6; 487 /* 488 * packets to a tentative, duplicated, or somehow invalid 489 * address must not be accepted. 490 */ 491 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 492 /* this address is ready */ 493 ours = 1; 494 deliverifp = ia6->ia_ifp; /* correct? */ 495 goto hbhcheck; 496 } else { 497 /* address is not ready, so discard the packet. */ 498 nd6log((LOG_INFO, 499 "ip6_input: packet to an unready address %s->%s\n", 500 ip6_sprintf(&ip6->ip6_src), 501 ip6_sprintf(&ip6->ip6_dst))); 502 503 goto bad; 504 } 505 } 506 507 /* 508 * FAITH (Firewall Aided Internet Translator) 509 */ 510 #if defined(NFAITH) && 0 < NFAITH 511 if (ip6_keepfaith) { 512 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp && 513 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 514 /* XXX do we need more sanity checks? */ 515 ours = 1; 516 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 517 goto hbhcheck; 518 } 519 } 520 #endif 521 522 #if 0 523 { 524 /* 525 * Last resort: check in6_ifaddr for incoming interface. 526 * The code is here until I update the "goto ours hack" code above 527 * working right. 528 */ 529 struct ifaddr *ifa; 530 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; 531 ifa; 532 ifa = ifa->ifa_list.tqe_next) { 533 if (ifa->ifa_addr == NULL) 534 continue; /* just for safety */ 535 if (ifa->ifa_addr->sa_family != AF_INET6) 536 continue; 537 if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ip6->ip6_dst)) { 538 ours = 1; 539 deliverifp = ifa->ifa_ifp; 540 goto hbhcheck; 541 } 542 } 543 } 544 #endif 545 546 /* 547 * Now there is no reason to process the packet if it's not our own 548 * and we're not a router. 549 */ 550 if (!ip6_forwarding) { 551 ip6stat.ip6s_cantforward++; 552 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 553 goto bad; 554 } 555 556 hbhcheck: 557 /* 558 * record address information into m_tag, if we don't have one yet. 559 * note that we are unable to record it, if the address is not listed 560 * as our interface address (e.g. multicast addresses, addresses 561 * within FAITH prefixes and such). 562 */ 563 if (deliverifp && !ip6_getdstifaddr(m)) { 564 struct in6_ifaddr *ia6; 565 566 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 567 if (ia6) { 568 if (!ip6_setdstifaddr(m, ia6)) { 569 /* 570 * XXX maybe we should drop the packet here, 571 * as we could not provide enough information 572 * to the upper layers. 573 */ 574 } 575 } 576 } 577 578 /* 579 * Process Hop-by-Hop options header if it's contained. 580 * m may be modified in ip6_hopopts_input(). 581 * If a JumboPayload option is included, plen will also be modified. 582 */ 583 plen = (u_int32_t)ntohs(ip6->ip6_plen); 584 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 585 struct ip6_hbh *hbh; 586 587 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 588 #if 0 /*touches NULL pointer*/ 589 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 590 #endif 591 return; /* m have already been freed */ 592 } 593 594 /* adjust pointer */ 595 ip6 = mtod(m, struct ip6_hdr *); 596 597 /* 598 * if the payload length field is 0 and the next header field 599 * indicates Hop-by-Hop Options header, then a Jumbo Payload 600 * option MUST be included. 601 */ 602 if (ip6->ip6_plen == 0 && plen == 0) { 603 /* 604 * Note that if a valid jumbo payload option is 605 * contained, ip6_hoptops_input() must set a valid 606 * (non-zero) payload length to the variable plen. 607 */ 608 ip6stat.ip6s_badoptions++; 609 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 610 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 611 icmp6_error(m, ICMP6_PARAM_PROB, 612 ICMP6_PARAMPROB_HEADER, 613 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 614 return; 615 } 616 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 617 sizeof(struct ip6_hbh)); 618 if (hbh == NULL) { 619 ip6stat.ip6s_tooshort++; 620 return; 621 } 622 KASSERT(IP6_HDR_ALIGNED_P(hbh)); 623 nxt = hbh->ip6h_nxt; 624 625 /* 626 * accept the packet if a router alert option is included 627 * and we act as an IPv6 router. 628 */ 629 if (rtalert != ~0 && ip6_forwarding) 630 ours = 1; 631 } else 632 nxt = ip6->ip6_nxt; 633 634 /* 635 * Check that the amount of data in the buffers 636 * is as at least much as the IPv6 header would have us expect. 637 * Trim mbufs if longer than we expect. 638 * Drop packet if shorter than we expect. 639 */ 640 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 641 ip6stat.ip6s_tooshort++; 642 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 643 goto bad; 644 } 645 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 646 if (m->m_len == m->m_pkthdr.len) { 647 m->m_len = sizeof(struct ip6_hdr) + plen; 648 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 649 } else 650 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 651 } 652 653 /* 654 * Forward if desirable. 655 */ 656 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 657 /* 658 * If we are acting as a multicast router, all 659 * incoming multicast packets are passed to the 660 * kernel-level multicast forwarding function. 661 * The packet is returned (relatively) intact; if 662 * ip6_mforward() returns a non-zero value, the packet 663 * must be discarded, else it may be accepted below. 664 */ 665 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 666 ip6stat.ip6s_cantforward++; 667 m_freem(m); 668 return; 669 } 670 if (!ours) { 671 m_freem(m); 672 return; 673 } 674 } else if (!ours) { 675 ip6_forward(m, srcrt); 676 return; 677 } 678 679 ip6 = mtod(m, struct ip6_hdr *); 680 681 /* 682 * Malicious party may be able to use IPv4 mapped addr to confuse 683 * tcp/udp stack and bypass security checks (act as if it was from 684 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 685 * 686 * For SIIT end node behavior, you may want to disable the check. 687 * However, you will become vulnerable to attacks using IPv4 mapped 688 * source. 689 */ 690 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 691 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 692 ip6stat.ip6s_badscope++; 693 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 694 goto bad; 695 } 696 697 /* 698 * Tell launch routine the next header 699 */ 700 #ifdef IFA_STATS 701 if (deliverifp != NULL) { 702 struct in6_ifaddr *ia6; 703 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 704 if (ia6) 705 ia6->ia_ifa.ifa_data.ifad_inbytes += m->m_pkthdr.len; 706 } 707 #endif 708 ip6stat.ip6s_delivered++; 709 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 710 nest = 0; 711 712 while (nxt != IPPROTO_DONE) { 713 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 714 ip6stat.ip6s_toomanyhdr++; 715 goto bad; 716 } 717 718 /* 719 * protection against faulty packet - there should be 720 * more sanity checks in header chain processing. 721 */ 722 if (m->m_pkthdr.len < off) { 723 ip6stat.ip6s_tooshort++; 724 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 725 goto bad; 726 } 727 728 #ifdef IPSEC 729 /* 730 * enforce IPsec policy checking if we are seeing last header. 731 * note that we do not visit this with protocols with pcb layer 732 * code - like udp/tcp/raw ip. 733 */ 734 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 735 ipsec6_in_reject(m, NULL)) { 736 ipsec6stat.in_polvio++; 737 goto bad; 738 } 739 #endif 740 741 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 742 } 743 return; 744 bad: 745 m_freem(m); 746 } 747 748 /* 749 * set/grab in6_ifaddr correspond to IPv6 destination address. 750 */ 751 static struct m_tag * 752 ip6_setdstifaddr(m, ia6) 753 struct mbuf *m; 754 struct in6_ifaddr *ia6; 755 { 756 struct m_tag *mtag; 757 758 mtag = ip6_addaux(m); 759 if (mtag) 760 ((struct ip6aux *)(mtag + 1))->ip6a_dstia6 = ia6; 761 return mtag; /* NULL if failed to set */ 762 } 763 764 struct in6_ifaddr * 765 ip6_getdstifaddr(m) 766 struct mbuf *m; 767 { 768 struct m_tag *mtag; 769 770 mtag = ip6_findaux(m); 771 if (mtag) 772 return ((struct ip6aux *)(mtag + 1))->ip6a_dstia6; 773 else 774 return NULL; 775 } 776 777 /* 778 * Hop-by-Hop options header processing. If a valid jumbo payload option is 779 * included, the real payload length will be stored in plenp. 780 */ 781 static int 782 ip6_hopopts_input(plenp, rtalertp, mp, offp) 783 u_int32_t *plenp; 784 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 785 struct mbuf **mp; 786 int *offp; 787 { 788 struct mbuf *m = *mp; 789 int off = *offp, hbhlen; 790 struct ip6_hbh *hbh; 791 792 /* validation of the length of the header */ 793 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 794 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 795 if (hbh == NULL) { 796 ip6stat.ip6s_tooshort++; 797 return -1; 798 } 799 hbhlen = (hbh->ip6h_len + 1) << 3; 800 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 801 hbhlen); 802 if (hbh == NULL) { 803 ip6stat.ip6s_tooshort++; 804 return -1; 805 } 806 KASSERT(IP6_HDR_ALIGNED_P(hbh)); 807 off += hbhlen; 808 hbhlen -= sizeof(struct ip6_hbh); 809 810 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 811 hbhlen, rtalertp, plenp) < 0) 812 return (-1); 813 814 *offp = off; 815 *mp = m; 816 return (0); 817 } 818 819 /* 820 * Search header for all Hop-by-hop options and process each option. 821 * This function is separate from ip6_hopopts_input() in order to 822 * handle a case where the sending node itself process its hop-by-hop 823 * options header. In such a case, the function is called from ip6_output(). 824 * 825 * The function assumes that hbh header is located right after the IPv6 header 826 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 827 * opthead + hbhlen is located in continuous memory region. 828 */ 829 int 830 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 831 struct mbuf *m; 832 u_int8_t *opthead; 833 int hbhlen; 834 u_int32_t *rtalertp; 835 u_int32_t *plenp; 836 { 837 struct ip6_hdr *ip6; 838 int optlen = 0; 839 u_int8_t *opt = opthead; 840 u_int16_t rtalert_val; 841 u_int32_t jumboplen; 842 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 843 844 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 845 switch (*opt) { 846 case IP6OPT_PAD1: 847 optlen = 1; 848 break; 849 case IP6OPT_PADN: 850 if (hbhlen < IP6OPT_MINLEN) { 851 ip6stat.ip6s_toosmall++; 852 goto bad; 853 } 854 optlen = *(opt + 1) + 2; 855 break; 856 case IP6OPT_RTALERT: 857 /* XXX may need check for alignment */ 858 if (hbhlen < IP6OPT_RTALERT_LEN) { 859 ip6stat.ip6s_toosmall++; 860 goto bad; 861 } 862 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 863 /* XXX stat */ 864 icmp6_error(m, ICMP6_PARAM_PROB, 865 ICMP6_PARAMPROB_HEADER, 866 erroff + opt + 1 - opthead); 867 return (-1); 868 } 869 optlen = IP6OPT_RTALERT_LEN; 870 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 871 *rtalertp = ntohs(rtalert_val); 872 break; 873 case IP6OPT_JUMBO: 874 /* XXX may need check for alignment */ 875 if (hbhlen < IP6OPT_JUMBO_LEN) { 876 ip6stat.ip6s_toosmall++; 877 goto bad; 878 } 879 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 880 /* XXX stat */ 881 icmp6_error(m, ICMP6_PARAM_PROB, 882 ICMP6_PARAMPROB_HEADER, 883 erroff + opt + 1 - opthead); 884 return (-1); 885 } 886 optlen = IP6OPT_JUMBO_LEN; 887 888 /* 889 * IPv6 packets that have non 0 payload length 890 * must not contain a jumbo payload option. 891 */ 892 ip6 = mtod(m, struct ip6_hdr *); 893 if (ip6->ip6_plen) { 894 ip6stat.ip6s_badoptions++; 895 icmp6_error(m, ICMP6_PARAM_PROB, 896 ICMP6_PARAMPROB_HEADER, 897 erroff + opt - opthead); 898 return (-1); 899 } 900 901 /* 902 * We may see jumbolen in unaligned location, so 903 * we'd need to perform bcopy(). 904 */ 905 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 906 jumboplen = (u_int32_t)htonl(jumboplen); 907 908 #if 1 909 /* 910 * if there are multiple jumbo payload options, 911 * *plenp will be non-zero and the packet will be 912 * rejected. 913 * the behavior may need some debate in ipngwg - 914 * multiple options does not make sense, however, 915 * there's no explicit mention in specification. 916 */ 917 if (*plenp != 0) { 918 ip6stat.ip6s_badoptions++; 919 icmp6_error(m, ICMP6_PARAM_PROB, 920 ICMP6_PARAMPROB_HEADER, 921 erroff + opt + 2 - opthead); 922 return (-1); 923 } 924 #endif 925 926 /* 927 * jumbo payload length must be larger than 65535. 928 */ 929 if (jumboplen <= IPV6_MAXPACKET) { 930 ip6stat.ip6s_badoptions++; 931 icmp6_error(m, ICMP6_PARAM_PROB, 932 ICMP6_PARAMPROB_HEADER, 933 erroff + opt + 2 - opthead); 934 return (-1); 935 } 936 *plenp = jumboplen; 937 938 break; 939 default: /* unknown option */ 940 if (hbhlen < IP6OPT_MINLEN) { 941 ip6stat.ip6s_toosmall++; 942 goto bad; 943 } 944 optlen = ip6_unknown_opt(opt, m, 945 erroff + opt - opthead); 946 if (optlen == -1) 947 return (-1); 948 optlen += 2; 949 break; 950 } 951 } 952 953 return (0); 954 955 bad: 956 m_freem(m); 957 return (-1); 958 } 959 960 /* 961 * Unknown option processing. 962 * The third argument `off' is the offset from the IPv6 header to the option, 963 * which is necessary if the IPv6 header the and option header and IPv6 header 964 * is not continuous in order to return an ICMPv6 error. 965 */ 966 int 967 ip6_unknown_opt(optp, m, off) 968 u_int8_t *optp; 969 struct mbuf *m; 970 int off; 971 { 972 struct ip6_hdr *ip6; 973 974 switch (IP6OPT_TYPE(*optp)) { 975 case IP6OPT_TYPE_SKIP: /* ignore the option */ 976 return ((int)*(optp + 1)); 977 case IP6OPT_TYPE_DISCARD: /* silently discard */ 978 m_freem(m); 979 return (-1); 980 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 981 ip6stat.ip6s_badoptions++; 982 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 983 return (-1); 984 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 985 ip6stat.ip6s_badoptions++; 986 ip6 = mtod(m, struct ip6_hdr *); 987 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 988 (m->m_flags & (M_BCAST|M_MCAST))) 989 m_freem(m); 990 else 991 icmp6_error(m, ICMP6_PARAM_PROB, 992 ICMP6_PARAMPROB_OPTION, off); 993 return (-1); 994 } 995 996 m_freem(m); /* XXX: NOTREACHED */ 997 return (-1); 998 } 999 1000 /* 1001 * Create the "control" list for this pcb. 1002 * 1003 * The routine will be called from upper layer handlers like tcp6_input(). 1004 * Thus the routine assumes that the caller (tcp6_input) have already 1005 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1006 * very first mbuf on the mbuf chain. 1007 * We may want to add some infinite loop prevention or sanity checks for safety. 1008 * (This applies only when you are using KAME mbuf chain restriction, i.e. 1009 * you are using IP6_EXTHDR_CHECK() not m_pulldown()) 1010 */ 1011 void 1012 ip6_savecontrol(in6p, mp, ip6, m) 1013 struct in6pcb *in6p; 1014 struct mbuf **mp; 1015 struct ip6_hdr *ip6; 1016 struct mbuf *m; 1017 { 1018 1019 #ifdef SO_TIMESTAMP 1020 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 1021 struct timeval tv; 1022 1023 microtime(&tv); 1024 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1025 SCM_TIMESTAMP, SOL_SOCKET); 1026 if (*mp) 1027 mp = &(*mp)->m_next; 1028 } 1029 #endif 1030 if (in6p->in6p_flags & IN6P_RECVDSTADDR) { 1031 *mp = sbcreatecontrol((caddr_t) &ip6->ip6_dst, 1032 sizeof(struct in6_addr), IPV6_RECVDSTADDR, IPPROTO_IPV6); 1033 if (*mp) 1034 mp = &(*mp)->m_next; 1035 } 1036 1037 #ifdef noyet 1038 /* options were tossed above */ 1039 if (in6p->in6p_flags & IN6P_RECVOPTS) 1040 /* broken */ 1041 /* ip6_srcroute doesn't do what we want here, need to fix */ 1042 if (in6p->in6p_flags & IPV6P_RECVRETOPTS) 1043 /* broken */ 1044 #endif 1045 1046 /* RFC 2292 sec. 5 */ 1047 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1048 struct in6_pktinfo pi6; 1049 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1050 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1051 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1052 ? m->m_pkthdr.rcvif->if_index 1053 : 0; 1054 *mp = sbcreatecontrol((caddr_t) &pi6, 1055 sizeof(struct in6_pktinfo), IPV6_PKTINFO, IPPROTO_IPV6); 1056 if (*mp) 1057 mp = &(*mp)->m_next; 1058 } 1059 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1060 int hlim = ip6->ip6_hlim & 0xff; 1061 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1062 IPV6_HOPLIMIT, IPPROTO_IPV6); 1063 if (*mp) 1064 mp = &(*mp)->m_next; 1065 } 1066 /* IN6P_NEXTHOP - for outgoing packet only */ 1067 1068 /* 1069 * IPV6_HOPOPTS socket option. Recall that we required super-user 1070 * privilege for the option (see ip6_ctloutput), but it might be too 1071 * strict, since there might be some hop-by-hop options which can be 1072 * returned to normal user. 1073 * See also RFC 2292 section 6. 1074 */ 1075 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1076 /* 1077 * Check if a hop-by-hop options header is contatined in the 1078 * received packet, and if so, store the options as ancillary 1079 * data. Note that a hop-by-hop options header must be 1080 * just after the IPv6 header, which fact is assured through 1081 * the IPv6 input processing. 1082 */ 1083 struct ip6_hdr *xip6 = mtod(m, struct ip6_hdr *); 1084 if (xip6->ip6_nxt == IPPROTO_HOPOPTS) { 1085 struct ip6_hbh *hbh; 1086 int hbhlen; 1087 struct mbuf *ext; 1088 1089 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1090 xip6->ip6_nxt); 1091 if (ext == NULL) { 1092 ip6stat.ip6s_tooshort++; 1093 return; 1094 } 1095 hbh = mtod(ext, struct ip6_hbh *); 1096 hbhlen = (hbh->ip6h_len + 1) << 3; 1097 if (hbhlen != ext->m_len) { 1098 m_freem(ext); 1099 ip6stat.ip6s_tooshort++; 1100 return; 1101 } 1102 1103 /* 1104 * XXX: We copy whole the header even if a jumbo 1105 * payload option is included, which option is to 1106 * be removed before returning in the RFC 2292. 1107 * But it's too painful operation... 1108 */ 1109 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1110 IPV6_HOPOPTS, IPPROTO_IPV6); 1111 if (*mp) 1112 mp = &(*mp)->m_next; 1113 m_freem(ext); 1114 } 1115 } 1116 1117 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1118 if (in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDR)) { 1119 struct ip6_hdr *xip6 = mtod(m, struct ip6_hdr *); 1120 int nxt = xip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1121 1122 /* 1123 * Search for destination options headers or routing 1124 * header(s) through the header chain, and stores each 1125 * header as ancillary data. 1126 * Note that the order of the headers remains in 1127 * the chain of ancillary data. 1128 */ 1129 while (1) { /* is explicit loop prevention necessary? */ 1130 struct ip6_ext *ip6e = NULL; 1131 int elen; 1132 struct mbuf *ext = NULL; 1133 1134 /* 1135 * if it is not an extension header, don't try to 1136 * pull it from the chain. 1137 */ 1138 switch (nxt) { 1139 case IPPROTO_DSTOPTS: 1140 case IPPROTO_ROUTING: 1141 case IPPROTO_HOPOPTS: 1142 case IPPROTO_AH: /* is it possible? */ 1143 break; 1144 default: 1145 goto loopend; 1146 } 1147 1148 ext = ip6_pullexthdr(m, off, nxt); 1149 if (ext == NULL) { 1150 ip6stat.ip6s_tooshort++; 1151 return; 1152 } 1153 ip6e = mtod(ext, struct ip6_ext *); 1154 if (nxt == IPPROTO_AH) 1155 elen = (ip6e->ip6e_len + 2) << 2; 1156 else 1157 elen = (ip6e->ip6e_len + 1) << 3; 1158 if (elen != ext->m_len) { 1159 m_freem(ext); 1160 ip6stat.ip6s_tooshort++; 1161 return; 1162 } 1163 KASSERT(IP6_HDR_ALIGNED_P(ip6e)); 1164 1165 switch (nxt) { 1166 case IPPROTO_DSTOPTS: 1167 if (!in6p->in6p_flags & IN6P_DSTOPTS) 1168 break; 1169 1170 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1171 IPV6_DSTOPTS, IPPROTO_IPV6); 1172 if (*mp) 1173 mp = &(*mp)->m_next; 1174 break; 1175 1176 case IPPROTO_ROUTING: 1177 if (!in6p->in6p_flags & IN6P_RTHDR) 1178 break; 1179 1180 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1181 IPV6_RTHDR, IPPROTO_IPV6); 1182 if (*mp) 1183 mp = &(*mp)->m_next; 1184 break; 1185 1186 case IPPROTO_HOPOPTS: 1187 case IPPROTO_AH: /* is it possible? */ 1188 break; 1189 1190 default: 1191 /* 1192 * other cases have been filtered in the above. 1193 * none will visit this case. here we supply 1194 * the code just in case (nxt overwritten or 1195 * other cases). 1196 */ 1197 m_freem(ext); 1198 goto loopend; 1199 1200 } 1201 1202 /* proceed with the next header. */ 1203 off += elen; 1204 nxt = ip6e->ip6e_nxt; 1205 ip6e = NULL; 1206 m_freem(ext); 1207 ext = NULL; 1208 } 1209 loopend: 1210 ; 1211 } 1212 } 1213 1214 /* 1215 * pull single extension header from mbuf chain. returns single mbuf that 1216 * contains the result, or NULL on error. 1217 */ 1218 static struct mbuf * 1219 ip6_pullexthdr(m, off, nxt) 1220 struct mbuf *m; 1221 size_t off; 1222 int nxt; 1223 { 1224 struct ip6_ext ip6e; 1225 size_t elen; 1226 struct mbuf *n; 1227 1228 #ifdef DIAGNOSTIC 1229 switch (nxt) { 1230 case IPPROTO_DSTOPTS: 1231 case IPPROTO_ROUTING: 1232 case IPPROTO_HOPOPTS: 1233 case IPPROTO_AH: /* is it possible? */ 1234 break; 1235 default: 1236 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1237 } 1238 #endif 1239 1240 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1241 if (nxt == IPPROTO_AH) 1242 elen = (ip6e.ip6e_len + 2) << 2; 1243 else 1244 elen = (ip6e.ip6e_len + 1) << 3; 1245 1246 MGET(n, M_DONTWAIT, MT_DATA); 1247 if (n && elen >= MLEN) { 1248 MCLGET(n, M_DONTWAIT); 1249 if ((n->m_flags & M_EXT) == 0) { 1250 m_free(n); 1251 n = NULL; 1252 } 1253 } 1254 if (!n) 1255 return NULL; 1256 1257 n->m_len = 0; 1258 if (elen >= M_TRAILINGSPACE(n)) { 1259 m_free(n); 1260 return NULL; 1261 } 1262 1263 m_copydata(m, off, elen, mtod(n, caddr_t)); 1264 n->m_len = elen; 1265 return n; 1266 } 1267 1268 /* 1269 * Get pointer to the previous header followed by the header 1270 * currently processed. 1271 * XXX: This function supposes that 1272 * M includes all headers, 1273 * the next header field and the header length field of each header 1274 * are valid, and 1275 * the sum of each header length equals to OFF. 1276 * Because of these assumptions, this function must be called very 1277 * carefully. Moreover, it will not be used in the near future when 1278 * we develop `neater' mechanism to process extension headers. 1279 */ 1280 u_int8_t * 1281 ip6_get_prevhdr(m, off) 1282 struct mbuf *m; 1283 int off; 1284 { 1285 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1286 1287 if (off == sizeof(struct ip6_hdr)) 1288 return (&ip6->ip6_nxt); 1289 else { 1290 int len, nxt; 1291 struct ip6_ext *ip6e = NULL; 1292 1293 nxt = ip6->ip6_nxt; 1294 len = sizeof(struct ip6_hdr); 1295 while (len < off) { 1296 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1297 1298 switch (nxt) { 1299 case IPPROTO_FRAGMENT: 1300 len += sizeof(struct ip6_frag); 1301 break; 1302 case IPPROTO_AH: 1303 len += (ip6e->ip6e_len + 2) << 2; 1304 break; 1305 default: 1306 len += (ip6e->ip6e_len + 1) << 3; 1307 break; 1308 } 1309 nxt = ip6e->ip6e_nxt; 1310 } 1311 if (ip6e) 1312 return (&ip6e->ip6e_nxt); 1313 else 1314 return NULL; 1315 } 1316 } 1317 1318 /* 1319 * get next header offset. m will be retained. 1320 */ 1321 int 1322 ip6_nexthdr(m, off, proto, nxtp) 1323 struct mbuf *m; 1324 int off; 1325 int proto; 1326 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 1398 /* 1399 * get offset for the last header in the chain. m will be kept untainted. 1400 */ 1401 int 1402 ip6_lasthdr(m, off, proto, nxtp) 1403 struct mbuf *m; 1404 int off; 1405 int proto; 1406 int *nxtp; 1407 { 1408 int newoff; 1409 int nxt; 1410 1411 if (!nxtp) { 1412 nxt = -1; 1413 nxtp = &nxt; 1414 } 1415 while (1) { 1416 newoff = ip6_nexthdr(m, off, proto, nxtp); 1417 if (newoff < 0) 1418 return off; 1419 else if (newoff < off) 1420 return -1; /* invalid */ 1421 else if (newoff == off) 1422 return newoff; 1423 1424 off = newoff; 1425 proto = *nxtp; 1426 } 1427 } 1428 1429 struct m_tag * 1430 ip6_addaux(m) 1431 struct mbuf *m; 1432 { 1433 struct m_tag *mtag; 1434 1435 mtag = m_tag_find(m, PACKET_TAG_INET6, NULL); 1436 if (!mtag) { 1437 mtag = m_tag_get(PACKET_TAG_INET6, sizeof(struct ip6aux), 1438 M_NOWAIT); 1439 if (mtag) { 1440 m_tag_prepend(m, mtag); 1441 bzero(mtag + 1, sizeof(struct ip6aux)); 1442 } 1443 } 1444 return mtag; 1445 } 1446 1447 struct m_tag * 1448 ip6_findaux(m) 1449 struct mbuf *m; 1450 { 1451 struct m_tag *mtag; 1452 1453 mtag = m_tag_find(m, PACKET_TAG_INET6, NULL); 1454 return mtag; 1455 } 1456 1457 void 1458 ip6_delaux(m) 1459 struct mbuf *m; 1460 { 1461 struct m_tag *mtag; 1462 1463 mtag = m_tag_find(m, PACKET_TAG_INET6, NULL); 1464 if (mtag) 1465 m_tag_delete(m, mtag); 1466 } 1467 1468 /* 1469 * System control for IP6 1470 */ 1471 1472 u_char inet6ctlerrmap[PRC_NCMDS] = { 1473 0, 0, 0, 0, 1474 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1475 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1476 EMSGSIZE, EHOSTUNREACH, 0, 0, 1477 0, 0, 0, 0, 1478 ENOPROTOOPT 1479 }; 1480 1481 SYSCTL_SETUP(sysctl_net_inet6_ip6_setup, "sysctl net.inet6.ip6 subtree setup") 1482 { 1483 1484 sysctl_createv(clog, 0, NULL, NULL, 1485 CTLFLAG_PERMANENT, 1486 CTLTYPE_NODE, "net", NULL, 1487 NULL, 0, NULL, 0, 1488 CTL_NET, CTL_EOL); 1489 sysctl_createv(clog, 0, NULL, NULL, 1490 CTLFLAG_PERMANENT, 1491 CTLTYPE_NODE, "inet6", 1492 SYSCTL_DESCR("PF_INET6 related settings"), 1493 NULL, 0, NULL, 0, 1494 CTL_NET, PF_INET6, CTL_EOL); 1495 sysctl_createv(clog, 0, NULL, NULL, 1496 CTLFLAG_PERMANENT, 1497 CTLTYPE_NODE, "ip6", 1498 SYSCTL_DESCR("IPv6 related settings"), 1499 NULL, 0, NULL, 0, 1500 CTL_NET, PF_INET6, IPPROTO_IPV6, CTL_EOL); 1501 1502 sysctl_createv(clog, 0, NULL, NULL, 1503 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1504 CTLTYPE_INT, "forwarding", 1505 SYSCTL_DESCR("Enable forwarding of INET6 datagrams"), 1506 NULL, 0, &ip6_forwarding, 0, 1507 CTL_NET, PF_INET6, IPPROTO_IPV6, 1508 IPV6CTL_FORWARDING, CTL_EOL); 1509 sysctl_createv(clog, 0, NULL, NULL, 1510 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1511 CTLTYPE_INT, "redirect", 1512 SYSCTL_DESCR("Enable sending of ICMPv6 redirect messages"), 1513 NULL, 0, &ip6_sendredirects, 0, 1514 CTL_NET, PF_INET6, IPPROTO_IPV6, 1515 IPV6CTL_SENDREDIRECTS, CTL_EOL); 1516 sysctl_createv(clog, 0, NULL, NULL, 1517 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1518 CTLTYPE_INT, "hlim", 1519 SYSCTL_DESCR("Hop limit for an INET6 datagram"), 1520 NULL, 0, &ip6_defhlim, 0, 1521 CTL_NET, PF_INET6, IPPROTO_IPV6, 1522 IPV6CTL_DEFHLIM, CTL_EOL); 1523 #ifdef notyet 1524 sysctl_createv(clog, 0, NULL, NULL, 1525 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1526 CTLTYPE_INT, "mtu", NULL, 1527 NULL, 0, &, 0, 1528 CTL_NET, PF_INET6, IPPROTO_IPV6, 1529 IPV6CTL_DEFMTU, CTL_EOL); 1530 #endif 1531 #ifdef __no_idea__ 1532 sysctl_createv(clog, 0, NULL, NULL, 1533 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1534 CTLTYPE_INT, "forwsrcrt", NULL, 1535 NULL, 0, &?, 0, 1536 CTL_NET, PF_INET6, IPPROTO_IPV6, 1537 IPV6CTL_FORWSRCRT, CTL_EOL); 1538 sysctl_createv(clog, 0, NULL, NULL, 1539 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1540 CTLTYPE_STRUCT, "mrtstats", NULL, 1541 NULL, 0, &?, sizeof(?), 1542 CTL_NET, PF_INET6, IPPROTO_IPV6, 1543 IPV6CTL_MRTSTATS, CTL_EOL); 1544 sysctl_createv(clog, 0, NULL, NULL, 1545 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1546 CTLTYPE_?, "mrtproto", NULL, 1547 NULL, 0, &?, sizeof(?), 1548 CTL_NET, PF_INET6, IPPROTO_IPV6, 1549 IPV6CTL_MRTPROTO, CTL_EOL); 1550 #endif 1551 sysctl_createv(clog, 0, NULL, NULL, 1552 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1553 CTLTYPE_INT, "maxfragpackets", 1554 SYSCTL_DESCR("Maximum number of fragments to buffer " 1555 "for reassembly"), 1556 NULL, 0, &ip6_maxfragpackets, 0, 1557 CTL_NET, PF_INET6, IPPROTO_IPV6, 1558 IPV6CTL_MAXFRAGPACKETS, CTL_EOL); 1559 #ifdef __no_idea__ 1560 sysctl_createv(clog, 0, NULL, NULL, 1561 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1562 CTLTYPE_INT, "sourcecheck", NULL, 1563 NULL, 0, &?, 0, 1564 CTL_NET, PF_INET6, IPPROTO_IPV6, 1565 IPV6CTL_SOURCECHECK, CTL_EOL); 1566 sysctl_createv(clog, 0, NULL, NULL, 1567 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1568 CTLTYPE_INT, "sourcecheck_logint", NULL, 1569 NULL, 0, &?, 0, 1570 CTL_NET, PF_INET6, IPPROTO_IPV6, 1571 IPV6CTL_SOURCECHECK_LOGINT, CTL_EOL); 1572 #endif 1573 sysctl_createv(clog, 0, NULL, NULL, 1574 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1575 CTLTYPE_INT, "accept_rtadv", 1576 SYSCTL_DESCR("Accept router advertisements"), 1577 NULL, 0, &ip6_accept_rtadv, 0, 1578 CTL_NET, PF_INET6, IPPROTO_IPV6, 1579 IPV6CTL_ACCEPT_RTADV, CTL_EOL); 1580 sysctl_createv(clog, 0, NULL, NULL, 1581 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1582 CTLTYPE_INT, "keepfaith", 1583 SYSCTL_DESCR("Activate faith interface"), 1584 NULL, 0, &ip6_keepfaith, 0, 1585 CTL_NET, PF_INET6, IPPROTO_IPV6, 1586 IPV6CTL_KEEPFAITH, CTL_EOL); 1587 sysctl_createv(clog, 0, NULL, NULL, 1588 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1589 CTLTYPE_INT, "log_interval", 1590 SYSCTL_DESCR("Minumum interval between logging " 1591 "unroutable packets"), 1592 NULL, 0, &ip6_log_interval, 0, 1593 CTL_NET, PF_INET6, IPPROTO_IPV6, 1594 IPV6CTL_LOG_INTERVAL, CTL_EOL); 1595 sysctl_createv(clog, 0, NULL, NULL, 1596 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1597 CTLTYPE_INT, "hdrnestlimit", 1598 SYSCTL_DESCR("Maximum number of nested IPv6 headers"), 1599 NULL, 0, &ip6_hdrnestlimit, 0, 1600 CTL_NET, PF_INET6, IPPROTO_IPV6, 1601 IPV6CTL_HDRNESTLIMIT, CTL_EOL); 1602 sysctl_createv(clog, 0, NULL, NULL, 1603 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1604 CTLTYPE_INT, "dad_count", 1605 SYSCTL_DESCR("Number of Duplicate Address Detection " 1606 "probes to send"), 1607 NULL, 0, &ip6_dad_count, 0, 1608 CTL_NET, PF_INET6, IPPROTO_IPV6, 1609 IPV6CTL_DAD_COUNT, CTL_EOL); 1610 sysctl_createv(clog, 0, NULL, NULL, 1611 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1612 CTLTYPE_INT, "auto_flowlabel", 1613 SYSCTL_DESCR("Assign random IPv6 flow labels"), 1614 NULL, 0, &ip6_auto_flowlabel, 0, 1615 CTL_NET, PF_INET6, IPPROTO_IPV6, 1616 IPV6CTL_AUTO_FLOWLABEL, CTL_EOL); 1617 sysctl_createv(clog, 0, NULL, NULL, 1618 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1619 CTLTYPE_INT, "defmcasthlim", 1620 SYSCTL_DESCR("Default multicast hop limit"), 1621 NULL, 0, &ip6_defmcasthlim, 0, 1622 CTL_NET, PF_INET6, IPPROTO_IPV6, 1623 IPV6CTL_DEFMCASTHLIM, CTL_EOL); 1624 #if NGIF > 0 1625 sysctl_createv(clog, 0, NULL, NULL, 1626 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1627 CTLTYPE_INT, "gifhlim", 1628 SYSCTL_DESCR("Default hop limit for a gif tunnel datagram"), 1629 NULL, 0, &ip6_gif_hlim, 0, 1630 CTL_NET, PF_INET6, IPPROTO_IPV6, 1631 IPV6CTL_GIF_HLIM, CTL_EOL); 1632 #endif /* NGIF */ 1633 sysctl_createv(clog, 0, NULL, NULL, 1634 CTLFLAG_PERMANENT, 1635 CTLTYPE_STRING, "kame_version", 1636 SYSCTL_DESCR("KAME Version"), 1637 NULL, 0, __UNCONST(__KAME_VERSION), 0, 1638 CTL_NET, PF_INET6, IPPROTO_IPV6, 1639 IPV6CTL_KAME_VERSION, CTL_EOL); 1640 sysctl_createv(clog, 0, NULL, NULL, 1641 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1642 CTLTYPE_INT, "use_deprecated", 1643 SYSCTL_DESCR("Allow use of deprecated addresses as " 1644 "source addresses"), 1645 NULL, 0, &ip6_use_deprecated, 0, 1646 CTL_NET, PF_INET6, IPPROTO_IPV6, 1647 IPV6CTL_USE_DEPRECATED, CTL_EOL); 1648 sysctl_createv(clog, 0, NULL, NULL, 1649 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1650 CTLTYPE_INT, "rr_prune", NULL, 1651 NULL, 0, &ip6_rr_prune, 0, 1652 CTL_NET, PF_INET6, IPPROTO_IPV6, 1653 IPV6CTL_RR_PRUNE, CTL_EOL); 1654 sysctl_createv(clog, 0, NULL, NULL, 1655 CTLFLAG_PERMANENT 1656 #ifndef INET6_BINDV6ONLY 1657 |CTLFLAG_READWRITE, 1658 #endif 1659 CTLTYPE_INT, "v6only", 1660 SYSCTL_DESCR("Disallow PF_INET6 sockets from connecting " 1661 "to PF_INET sockets"), 1662 NULL, 0, &ip6_v6only, 0, 1663 CTL_NET, PF_INET6, IPPROTO_IPV6, 1664 IPV6CTL_V6ONLY, CTL_EOL); 1665 sysctl_createv(clog, 0, NULL, NULL, 1666 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1667 CTLTYPE_INT, "anonportmin", 1668 SYSCTL_DESCR("Lowest ephemeral port number to assign"), 1669 sysctl_net_inet_ip_ports, 0, &ip6_anonportmin, 0, 1670 CTL_NET, PF_INET6, IPPROTO_IPV6, 1671 IPV6CTL_ANONPORTMIN, CTL_EOL); 1672 sysctl_createv(clog, 0, NULL, NULL, 1673 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1674 CTLTYPE_INT, "anonportmax", 1675 SYSCTL_DESCR("Highest ephemeral port number to assign"), 1676 sysctl_net_inet_ip_ports, 0, &ip6_anonportmax, 0, 1677 CTL_NET, PF_INET6, IPPROTO_IPV6, 1678 IPV6CTL_ANONPORTMAX, CTL_EOL); 1679 #ifndef IPNOPRIVPORTS 1680 sysctl_createv(clog, 0, NULL, NULL, 1681 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1682 CTLTYPE_INT, "lowportmin", 1683 SYSCTL_DESCR("Lowest privileged ephemeral port number " 1684 "to assign"), 1685 sysctl_net_inet_ip_ports, 0, &ip6_lowportmin, 0, 1686 CTL_NET, PF_INET6, IPPROTO_IPV6, 1687 IPV6CTL_LOWPORTMIN, CTL_EOL); 1688 sysctl_createv(clog, 0, NULL, NULL, 1689 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1690 CTLTYPE_INT, "lowportmax", 1691 SYSCTL_DESCR("Highest privileged ephemeral port number " 1692 "to assign"), 1693 sysctl_net_inet_ip_ports, 0, &ip6_lowportmax, 0, 1694 CTL_NET, PF_INET6, IPPROTO_IPV6, 1695 IPV6CTL_LOWPORTMAX, CTL_EOL); 1696 #endif /* IPNOPRIVPORTS */ 1697 sysctl_createv(clog, 0, NULL, NULL, 1698 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1699 CTLTYPE_INT, "maxfrags", 1700 SYSCTL_DESCR("Maximum fragments in reassembly queue"), 1701 NULL, 0, &ip6_maxfrags, 0, 1702 CTL_NET, PF_INET6, IPPROTO_IPV6, 1703 IPV6CTL_MAXFRAGS, CTL_EOL); 1704 sysctl_createv(clog, 0, NULL, NULL, 1705 CTLFLAG_PERMANENT, 1706 CTLTYPE_STRUCT, "stats", 1707 SYSCTL_DESCR("IPv6 statistics"), 1708 NULL, 0, &ip6stat, sizeof(ip6stat), 1709 CTL_NET, PF_INET6, IPPROTO_IPV6, 1710 IPV6CTL_STATS, CTL_EOL); 1711 sysctl_createv(clog, 0, NULL, NULL, 1712 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1713 CTLTYPE_INT, "use_defaultzone", 1714 SYSCTL_DESCR("Whether to use the default scope zones"), 1715 NULL, 0, &ip6_use_defzone, 0, 1716 CTL_NET, PF_INET6, IPPROTO_IPV6, 1717 IPV6CTL_USE_DEFAULTZONE, CTL_EOL); 1718 } 1719