1 /* $OpenBSD: ip6_input.c,v 1.127 2014/07/08 17:19:26 deraadt 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/mbuf.h> 70 #include <sys/domain.h> 71 #include <sys/sysctl.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/timeout.h> 78 #include <sys/kernel.h> 79 #include <sys/syslog.h> 80 81 #include <net/if.h> 82 #include <net/if_types.h> 83 #include <net/if_dl.h> 84 #include <net/route.h> 85 #include <net/netisr.h> 86 87 #include <netinet/in.h> 88 #include <netinet/in_systm.h> 89 90 #ifdef INET 91 #include <netinet/ip.h> 92 #endif 93 94 #include <netinet/in_pcb.h> 95 #include <netinet6/in6_var.h> 96 #include <netinet/ip6.h> 97 #include <netinet6/ip6_var.h> 98 #include <netinet/icmp6.h> 99 #include <netinet6/in6_ifattach.h> 100 #include <netinet6/nd6.h> 101 102 #include <netinet6/ip6protosw.h> 103 104 #include "gif.h" 105 #include "bpfilter.h" 106 107 #ifdef MROUTING 108 #include <netinet6/ip6_mroute.h> 109 #endif 110 111 #if NPF > 0 112 #include <net/pfvar.h> 113 #endif 114 115 #if NCARP > 0 116 #include <netinet/ip_carp.h> 117 #endif 118 119 struct in6_ifaddrhead in6_ifaddr; 120 struct ifqueue ip6intrq; 121 122 struct ip6stat ip6stat; 123 124 void ip6_init2(void *); 125 int ip6_check_rh0hdr(struct mbuf *, int *); 126 127 int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 128 struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 129 130 /* 131 * IP6 initialization: fill in IP6 protocol switch table. 132 * All protocols not implemented in kernel go to raw IP6 protocol handler. 133 */ 134 void 135 ip6_init(void) 136 { 137 struct ip6protosw *pr; 138 int i; 139 140 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 141 if (pr == 0) 142 panic("ip6_init"); 143 for (i = 0; i < IPPROTO_MAX; i++) 144 ip6_protox[i] = pr - inet6sw; 145 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 146 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 147 if (pr->pr_domain->dom_family == PF_INET6 && 148 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW && 149 pr->pr_protocol < IPPROTO_MAX) 150 ip6_protox[pr->pr_protocol] = pr - inet6sw; 151 IFQ_SET_MAXLEN(&ip6intrq, IFQ_MAXLEN); 152 TAILQ_INIT(&in6_ifaddr); 153 ip6_randomid_init(); 154 nd6_init(); 155 frag6_init(); 156 ip6_init2((void *)0); 157 } 158 159 void 160 ip6_init2(void *dummy) 161 { 162 163 /* nd6_timer_init */ 164 bzero(&nd6_timer_ch, sizeof(nd6_timer_ch)); 165 timeout_set(&nd6_timer_ch, nd6_timer, NULL); 166 timeout_add_sec(&nd6_timer_ch, 1); 167 } 168 169 /* 170 * IP6 input interrupt handling. Just pass the packet to ip6_input. 171 */ 172 void 173 ip6intr(void) 174 { 175 int s; 176 struct mbuf *m; 177 178 for (;;) { 179 s = splnet(); 180 IF_DEQUEUE(&ip6intrq, m); 181 splx(s); 182 if (m == NULL) 183 return; 184 ip6_input(m); 185 } 186 } 187 188 extern struct route_in6 ip6_forward_rt; 189 190 void 191 ip6_input(struct mbuf *m) 192 { 193 struct ifnet *ifp; 194 struct ip6_hdr *ip6; 195 int off, nest; 196 u_int32_t plen; 197 u_int32_t rtalert = ~0; 198 int nxt, ours = 0; 199 struct ifnet *deliverifp = NULL; 200 #if NPF > 0 201 struct in6_addr odst; 202 #endif 203 int srcrt = 0, isanycast = 0; 204 u_int rtableid = 0; 205 206 ifp = m->m_pkthdr.rcvif; 207 208 if (m->m_flags & M_EXT) { 209 if (m->m_next) 210 ip6stat.ip6s_mext2m++; 211 else 212 ip6stat.ip6s_mext1++; 213 } else { 214 if (m->m_next) { 215 if (m->m_flags & M_LOOP) { 216 ip6stat.ip6s_m2m[lo0ifp->if_index]++; /*XXX*/ 217 } else if (ifp->if_index < nitems(ip6stat.ip6s_m2m)) 218 ip6stat.ip6s_m2m[ifp->if_index]++; 219 else 220 ip6stat.ip6s_m2m[0]++; 221 } else 222 ip6stat.ip6s_m1++; 223 } 224 225 in6_ifstat_inc(ifp, ifs6_in_receive); 226 ip6stat.ip6s_total++; 227 228 if (m->m_len < sizeof(struct ip6_hdr)) { 229 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 230 ip6stat.ip6s_toosmall++; 231 in6_ifstat_inc(ifp, ifs6_in_hdrerr); 232 return; 233 } 234 } 235 236 ip6 = mtod(m, struct ip6_hdr *); 237 238 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 239 ip6stat.ip6s_badvers++; 240 in6_ifstat_inc(ifp, ifs6_in_hdrerr); 241 goto bad; 242 } 243 244 #if NCARP > 0 245 if (ifp->if_type == IFT_CARP && ip6->ip6_nxt != IPPROTO_ICMPV6 && 246 carp_lsdrop(m, AF_INET6, ip6->ip6_src.s6_addr32, 247 ip6->ip6_dst.s6_addr32)) 248 goto bad; 249 #endif 250 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 251 252 /* 253 * Check against address spoofing/corruption. 254 */ 255 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 256 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 257 /* 258 * XXX: "badscope" is not very suitable for a multicast source. 259 */ 260 ip6stat.ip6s_badscope++; 261 in6_ifstat_inc(ifp, ifs6_in_addrerr); 262 goto bad; 263 } 264 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 265 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 266 (ifp->if_flags & IFF_LOOPBACK) == 0) { 267 ip6stat.ip6s_badscope++; 268 in6_ifstat_inc(ifp, ifs6_in_addrerr); 269 goto bad; 270 } 271 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 272 !(m->m_flags & M_LOOP)) { 273 /* 274 * In this case, the packet should come from the loopback 275 * interface. However, we cannot just check the if_flags, 276 * because ip6_mloopback() passes the "actual" interface 277 * as the outgoing/incoming interface. 278 */ 279 ip6stat.ip6s_badscope++; 280 in6_ifstat_inc(ifp, ifs6_in_addrerr); 281 goto bad; 282 } 283 284 /* 285 * The following check is not documented in specs. A malicious 286 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 287 * and bypass security checks (act as if it was from 127.0.0.1 by using 288 * IPv6 src ::ffff:127.0.0.1). Be cautious. 289 * 290 * This check chokes if we are in an SIIT cloud. As none of BSDs 291 * support IPv4-less kernel compilation, we cannot support SIIT 292 * environment at all. So, it makes more sense for us to reject any 293 * malicious packets for non-SIIT environment, than try to do a 294 * partial support for SIIT environment. 295 */ 296 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 297 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 298 ip6stat.ip6s_badscope++; 299 in6_ifstat_inc(ifp, ifs6_in_addrerr); 300 goto bad; 301 } 302 #if 0 303 /* 304 * Reject packets with IPv4 compatible addresses (auto tunnel). 305 * 306 * The code forbids auto tunnel relay case in RFC1933 (the check is 307 * stronger than RFC1933). We may want to re-enable it if mech-xx 308 * is revised to forbid relaying case. 309 */ 310 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 311 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 312 ip6stat.ip6s_badscope++; 313 in6_ifstat_inc(ifp, ifs6_in_addrerr); 314 goto bad; 315 } 316 #endif 317 318 #if NPF > 0 319 /* 320 * Packet filter 321 */ 322 odst = ip6->ip6_dst; 323 if (pf_test(AF_INET6, PF_IN, ifp, &m, NULL) != PF_PASS) 324 goto bad; 325 if (m == NULL) 326 return; 327 328 ip6 = mtod(m, struct ip6_hdr *); 329 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 330 #endif 331 332 /* 333 * Be more secure than RFC5095 and scan for type 0 routing headers. 334 * If pf has already scanned the header chain, do not do it twice. 335 */ 336 if (!(m->m_pkthdr.pf.flags & PF_TAG_PROCESSED) && 337 ip6_check_rh0hdr(m, &off)) { 338 ip6stat.ip6s_badoptions++; 339 in6_ifstat_inc(ifp, ifs6_in_discard); 340 in6_ifstat_inc(ifp, ifs6_in_hdrerr); 341 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, off); 342 /* m is already freed */ 343 return; 344 } 345 346 if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 347 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) { 348 ours = 1; 349 deliverifp = ifp; 350 goto hbhcheck; 351 } 352 353 /* drop packets if interface ID portion is already filled */ 354 if ((IN6_IS_SCOPE_EMBED(&ip6->ip6_src) && ip6->ip6_src.s6_addr16[1]) || 355 (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst) && ip6->ip6_dst.s6_addr16[1])) { 356 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 357 ip6stat.ip6s_badscope++; 358 goto bad; 359 } 360 } 361 362 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) 363 ip6->ip6_src.s6_addr16[1] = htons(ifp->if_index); 364 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) 365 ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); 366 367 /* 368 * We use rt->rt_ifp to determine if the address is ours or not. 369 * If rt_ifp is lo0, the address is ours. 370 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 371 * so any address under fe80::%lo0/64 will be mistakenly considered 372 * local. The special case is supplied to handle the case properly 373 * by actually looking at interface addresses 374 * (using in6ifa_ifpwithaddr). 375 */ 376 if ((ifp->if_flags & IFF_LOOPBACK) != 0 && 377 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 378 if (!in6ifa_ifpwithaddr(ifp, &ip6->ip6_dst)) { 379 icmp6_error(m, ICMP6_DST_UNREACH, 380 ICMP6_DST_UNREACH_ADDR, 0); 381 /* m is already freed */ 382 return; 383 } 384 385 ours = 1; 386 deliverifp = ifp; 387 goto hbhcheck; 388 } 389 390 if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) { 391 ours = 1; 392 deliverifp = ifp; 393 goto hbhcheck; 394 } 395 396 /* 397 * Multicast check 398 */ 399 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 400 struct in6_multi *in6m = 0; 401 402 in6_ifstat_inc(ifp, ifs6_in_mcast); 403 /* 404 * See if we belong to the destination multicast group on the 405 * arrival interface. 406 */ 407 IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m); 408 if (in6m) 409 ours = 1; 410 #ifdef MROUTING 411 else if (!ip6_mforwarding || !ip6_mrouter) 412 #else 413 else 414 #endif 415 { 416 ip6stat.ip6s_notmember++; 417 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 418 ip6stat.ip6s_cantforward++; 419 in6_ifstat_inc(ifp, ifs6_in_discard); 420 goto bad; 421 } 422 deliverifp = ifp; 423 goto hbhcheck; 424 } 425 426 #if NPF > 0 427 rtableid = m->m_pkthdr.ph_rtableid; 428 #endif 429 430 /* 431 * Unicast check 432 */ 433 if (ip6_forward_rt.ro_rt != NULL && 434 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 435 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 436 &ip6_forward_rt.ro_dst.sin6_addr) && 437 rtableid == ip6_forward_rt.ro_tableid) 438 ip6stat.ip6s_forward_cachehit++; 439 else { 440 if (ip6_forward_rt.ro_rt) { 441 /* route is down or destination is different */ 442 ip6stat.ip6s_forward_cachemiss++; 443 RTFREE(ip6_forward_rt.ro_rt); 444 ip6_forward_rt.ro_rt = 0; 445 } 446 447 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 448 ip6_forward_rt.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 449 ip6_forward_rt.ro_dst.sin6_family = AF_INET6; 450 ip6_forward_rt.ro_dst.sin6_addr = ip6->ip6_dst; 451 ip6_forward_rt.ro_tableid = rtableid; 452 453 rtalloc_mpath((struct route *)&ip6_forward_rt, 454 &ip6->ip6_src.s6_addr32[0]); 455 } 456 457 /* 458 * Accept the packet if the forwarding interface to the destination 459 * according to the routing table is the loopback interface, 460 * unless the associated route has a gateway. 461 * Note that this approach causes to accept a packet if there is a 462 * route to the loopback interface for the destination of the packet. 463 * But we think it's even useful in some situations, e.g. when using 464 * a special daemon which wants to intercept the packet. 465 */ 466 if (ip6_forward_rt.ro_rt && 467 (ip6_forward_rt.ro_rt->rt_flags & 468 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 469 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 470 struct in6_ifaddr *ia6 = 471 ifatoia6(ip6_forward_rt.ro_rt->rt_ifa); 472 if (ia6->ia6_flags & IN6_IFF_ANYCAST) 473 isanycast = 1; 474 /* 475 * packets to a tentative, duplicated, or somehow invalid 476 * address must not be accepted. 477 */ 478 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 479 /* this address is ready */ 480 ours = 1; 481 deliverifp = ia6->ia_ifp; /* correct? */ 482 goto hbhcheck; 483 } else { 484 char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; 485 486 inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)); 487 inet_ntop(AF_INET6, &ip6->ip6_dst, dst, sizeof(dst)); 488 /* address is not ready, so discard the packet. */ 489 nd6log((LOG_INFO, 490 "ip6_input: packet to an unready address %s->%s\n", 491 src, dst)); 492 493 goto bad; 494 } 495 } 496 497 #if NCARP > 0 498 if (ifp->if_type == IFT_CARP && ip6->ip6_nxt == IPPROTO_ICMPV6 && 499 carp_lsdrop(m, AF_INET6, ip6->ip6_src.s6_addr32, 500 ip6->ip6_dst.s6_addr32)) 501 goto bad; 502 #endif 503 /* 504 * Now there is no reason to process the packet if it's not our own 505 * and we're not a router. 506 */ 507 if (!ip6_forwarding) { 508 ip6stat.ip6s_cantforward++; 509 in6_ifstat_inc(ifp, ifs6_in_discard); 510 goto bad; 511 } 512 513 hbhcheck: 514 /* 515 * Process Hop-by-Hop options header if it's contained. 516 * m may be modified in ip6_hopopts_input(). 517 * If a JumboPayload option is included, plen will also be modified. 518 */ 519 plen = (u_int32_t)ntohs(ip6->ip6_plen); 520 off = sizeof(struct ip6_hdr); 521 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 522 struct ip6_hbh *hbh; 523 524 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 525 #if 0 /*touches NULL pointer*/ 526 in6_ifstat_inc(ifp, ifs6_in_discard); 527 #endif 528 return; /* m have already been freed */ 529 } 530 531 /* adjust pointer */ 532 ip6 = mtod(m, struct ip6_hdr *); 533 534 /* 535 * if the payload length field is 0 and the next header field 536 * indicates Hop-by-Hop Options header, then a Jumbo Payload 537 * option MUST be included. 538 */ 539 if (ip6->ip6_plen == 0 && plen == 0) { 540 /* 541 * Note that if a valid jumbo payload option is 542 * contained, ip6_hoptops_input() must set a valid 543 * (non-zero) payload length to the variable plen. 544 */ 545 ip6stat.ip6s_badoptions++; 546 in6_ifstat_inc(ifp, ifs6_in_discard); 547 in6_ifstat_inc(ifp, ifs6_in_hdrerr); 548 icmp6_error(m, ICMP6_PARAM_PROB, 549 ICMP6_PARAMPROB_HEADER, 550 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 551 return; 552 } 553 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 554 sizeof(struct ip6_hbh)); 555 if (hbh == NULL) { 556 ip6stat.ip6s_tooshort++; 557 return; 558 } 559 nxt = hbh->ip6h_nxt; 560 561 /* 562 * accept the packet if a router alert option is included 563 * and we act as an IPv6 router. 564 */ 565 if (rtalert != ~0 && ip6_forwarding) 566 ours = 1; 567 } else 568 nxt = ip6->ip6_nxt; 569 570 /* 571 * Check that the amount of data in the buffers 572 * is as at least much as the IPv6 header would have us expect. 573 * Trim mbufs if longer than we expect. 574 * Drop packet if shorter than we expect. 575 */ 576 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 577 ip6stat.ip6s_tooshort++; 578 in6_ifstat_inc(ifp, ifs6_in_truncated); 579 goto bad; 580 } 581 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 582 if (m->m_len == m->m_pkthdr.len) { 583 m->m_len = sizeof(struct ip6_hdr) + plen; 584 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 585 } else 586 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 587 } 588 589 /* 590 * Forward if desirable. 591 */ 592 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 593 /* 594 * If we are acting as a multicast router, all 595 * incoming multicast packets are passed to the 596 * kernel-level multicast forwarding function. 597 * The packet is returned (relatively) intact; if 598 * ip6_mforward() returns a non-zero value, the packet 599 * must be discarded, else it may be accepted below. 600 */ 601 #ifdef MROUTING 602 if (ip6_mforwarding && ip6_mrouter && 603 ip6_mforward(ip6, ifp, m)) { 604 ip6stat.ip6s_cantforward++; 605 m_freem(m); 606 return; 607 } 608 #endif 609 if (!ours) { 610 m_freem(m); 611 return; 612 } 613 } else if (!ours) { 614 ip6_forward(m, srcrt); 615 return; 616 } 617 618 /* pf might have changed things */ 619 in6_proto_cksum_out(m, NULL); 620 621 ip6 = mtod(m, struct ip6_hdr *); 622 623 /* 624 * Malicious party may be able to use IPv4 mapped addr to confuse 625 * tcp/udp stack and bypass security checks (act as if it was from 626 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 627 * 628 * For SIIT end node behavior, you may want to disable the check. 629 * However, you will become vulnerable to attacks using IPv4 mapped 630 * source. 631 */ 632 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 633 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 634 ip6stat.ip6s_badscope++; 635 in6_ifstat_inc(ifp, ifs6_in_addrerr); 636 goto bad; 637 } 638 639 /* 640 * Tell launch routine the next header 641 */ 642 ip6stat.ip6s_delivered++; 643 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 644 nest = 0; 645 646 while (nxt != IPPROTO_DONE) { 647 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 648 ip6stat.ip6s_toomanyhdr++; 649 goto bad; 650 } 651 652 /* 653 * protection against faulty packet - there should be 654 * more sanity checks in header chain processing. 655 */ 656 if (m->m_pkthdr.len < off) { 657 ip6stat.ip6s_tooshort++; 658 in6_ifstat_inc(ifp, ifs6_in_truncated); 659 goto bad; 660 } 661 662 /* draft-itojun-ipv6-tcp-to-anycast */ 663 if (isanycast && nxt == IPPROTO_TCP) { 664 if (m->m_len >= sizeof(struct ip6_hdr)) { 665 ip6 = mtod(m, struct ip6_hdr *); 666 icmp6_error(m, ICMP6_DST_UNREACH, 667 ICMP6_DST_UNREACH_ADDR, 668 (caddr_t)&ip6->ip6_dst - (caddr_t)ip6); 669 break; 670 } else 671 goto bad; 672 } 673 674 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 675 } 676 return; 677 bad: 678 m_freem(m); 679 } 680 681 /* scan packet for RH0 routing header. Mostly stolen from pf.c:pf_test() */ 682 int 683 ip6_check_rh0hdr(struct mbuf *m, int *offp) 684 { 685 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 686 struct ip6_rthdr rthdr; 687 struct ip6_ext opt6; 688 u_int8_t proto = ip6->ip6_nxt; 689 int done = 0, lim, off, rh_cnt = 0; 690 691 off = ((caddr_t)ip6 - m->m_data) + sizeof(struct ip6_hdr); 692 lim = min(m->m_pkthdr.len, ntohs(ip6->ip6_plen) + sizeof(*ip6)); 693 do { 694 switch (proto) { 695 case IPPROTO_ROUTING: 696 *offp = off; 697 if (rh_cnt++) { 698 /* more then one rh header present */ 699 return (1); 700 } 701 702 if (off + sizeof(rthdr) > lim) { 703 /* packet to short to make sense */ 704 return (1); 705 } 706 707 m_copydata(m, off, sizeof(rthdr), (caddr_t)&rthdr); 708 709 if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) { 710 *offp += offsetof(struct ip6_rthdr, ip6r_type); 711 return (1); 712 } 713 714 off += (rthdr.ip6r_len + 1) * 8; 715 proto = rthdr.ip6r_nxt; 716 break; 717 case IPPROTO_AH: 718 case IPPROTO_HOPOPTS: 719 case IPPROTO_DSTOPTS: 720 /* get next header and header length */ 721 if (off + sizeof(opt6) > lim) { 722 /* 723 * Packet to short to make sense, we could 724 * reject the packet but as a router we 725 * should not do that so forward it. 726 */ 727 return (0); 728 } 729 730 m_copydata(m, off, sizeof(opt6), (caddr_t)&opt6); 731 732 if (proto == IPPROTO_AH) 733 off += (opt6.ip6e_len + 2) * 4; 734 else 735 off += (opt6.ip6e_len + 1) * 8; 736 proto = opt6.ip6e_nxt; 737 break; 738 case IPPROTO_FRAGMENT: 739 default: 740 /* end of header stack */ 741 done = 1; 742 break; 743 } 744 } while (!done); 745 746 return (0); 747 } 748 749 /* 750 * Hop-by-Hop options header processing. If a valid jumbo payload option is 751 * included, the real payload length will be stored in plenp. 752 * 753 * rtalertp - XXX: should be stored in a more smart way 754 */ 755 int 756 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, struct mbuf **mp, 757 int *offp) 758 { 759 struct mbuf *m = *mp; 760 int off = *offp, hbhlen; 761 struct ip6_hbh *hbh; 762 763 /* validation of the length of the header */ 764 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 765 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 766 if (hbh == NULL) { 767 ip6stat.ip6s_tooshort++; 768 return -1; 769 } 770 hbhlen = (hbh->ip6h_len + 1) << 3; 771 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 772 hbhlen); 773 if (hbh == NULL) { 774 ip6stat.ip6s_tooshort++; 775 return -1; 776 } 777 off += hbhlen; 778 hbhlen -= sizeof(struct ip6_hbh); 779 780 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 781 hbhlen, rtalertp, plenp) < 0) 782 return (-1); 783 784 *offp = off; 785 *mp = m; 786 return (0); 787 } 788 789 /* 790 * Search header for all Hop-by-hop options and process each option. 791 * This function is separate from ip6_hopopts_input() in order to 792 * handle a case where the sending node itself process its hop-by-hop 793 * options header. In such a case, the function is called from ip6_output(). 794 * 795 * The function assumes that hbh header is located right after the IPv6 header 796 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 797 * opthead + hbhlen is located in continuous memory region. 798 */ 799 int 800 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 801 u_int32_t *rtalertp, u_int32_t *plenp) 802 { 803 struct ip6_hdr *ip6; 804 int optlen = 0; 805 u_int8_t *opt = opthead; 806 u_int16_t rtalert_val; 807 u_int32_t jumboplen; 808 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 809 810 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 811 switch (*opt) { 812 case IP6OPT_PAD1: 813 optlen = 1; 814 break; 815 case IP6OPT_PADN: 816 if (hbhlen < IP6OPT_MINLEN) { 817 ip6stat.ip6s_toosmall++; 818 goto bad; 819 } 820 optlen = *(opt + 1) + 2; 821 break; 822 case IP6OPT_ROUTER_ALERT: 823 /* XXX may need check for alignment */ 824 if (hbhlen < IP6OPT_RTALERT_LEN) { 825 ip6stat.ip6s_toosmall++; 826 goto bad; 827 } 828 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 829 /* XXX stat */ 830 icmp6_error(m, ICMP6_PARAM_PROB, 831 ICMP6_PARAMPROB_HEADER, 832 erroff + opt + 1 - opthead); 833 return (-1); 834 } 835 optlen = IP6OPT_RTALERT_LEN; 836 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 837 *rtalertp = ntohs(rtalert_val); 838 break; 839 case IP6OPT_JUMBO: 840 /* XXX may need check for alignment */ 841 if (hbhlen < IP6OPT_JUMBO_LEN) { 842 ip6stat.ip6s_toosmall++; 843 goto bad; 844 } 845 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 846 /* XXX stat */ 847 icmp6_error(m, ICMP6_PARAM_PROB, 848 ICMP6_PARAMPROB_HEADER, 849 erroff + opt + 1 - opthead); 850 return (-1); 851 } 852 optlen = IP6OPT_JUMBO_LEN; 853 854 /* 855 * IPv6 packets that have non 0 payload length 856 * must not contain a jumbo payload option. 857 */ 858 ip6 = mtod(m, struct ip6_hdr *); 859 if (ip6->ip6_plen) { 860 ip6stat.ip6s_badoptions++; 861 icmp6_error(m, ICMP6_PARAM_PROB, 862 ICMP6_PARAMPROB_HEADER, 863 erroff + opt - opthead); 864 return (-1); 865 } 866 867 /* 868 * We may see jumbolen in unaligned location, so 869 * we'd need to perform bcopy(). 870 */ 871 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 872 jumboplen = (u_int32_t)htonl(jumboplen); 873 874 #if 1 875 /* 876 * if there are multiple jumbo payload options, 877 * *plenp will be non-zero and the packet will be 878 * rejected. 879 * the behavior may need some debate in ipngwg - 880 * multiple options does not make sense, however, 881 * there's no explicit mention in specification. 882 */ 883 if (*plenp != 0) { 884 ip6stat.ip6s_badoptions++; 885 icmp6_error(m, ICMP6_PARAM_PROB, 886 ICMP6_PARAMPROB_HEADER, 887 erroff + opt + 2 - opthead); 888 return (-1); 889 } 890 #endif 891 892 /* 893 * jumbo payload length must be larger than 65535. 894 */ 895 if (jumboplen <= IPV6_MAXPACKET) { 896 ip6stat.ip6s_badoptions++; 897 icmp6_error(m, ICMP6_PARAM_PROB, 898 ICMP6_PARAMPROB_HEADER, 899 erroff + opt + 2 - opthead); 900 return (-1); 901 } 902 *plenp = jumboplen; 903 904 break; 905 default: /* unknown option */ 906 if (hbhlen < IP6OPT_MINLEN) { 907 ip6stat.ip6s_toosmall++; 908 goto bad; 909 } 910 optlen = ip6_unknown_opt(opt, m, 911 erroff + opt - opthead); 912 if (optlen == -1) 913 return (-1); 914 optlen += 2; 915 break; 916 } 917 } 918 919 return (0); 920 921 bad: 922 m_freem(m); 923 return (-1); 924 } 925 926 /* 927 * Unknown option processing. 928 * The third argument `off' is the offset from the IPv6 header to the option, 929 * which allows returning an ICMPv6 error even if the IPv6 header and the 930 * option header are not continuous. 931 */ 932 int 933 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 934 { 935 struct ip6_hdr *ip6; 936 937 switch (IP6OPT_TYPE(*optp)) { 938 case IP6OPT_TYPE_SKIP: /* ignore the option */ 939 return ((int)*(optp + 1)); 940 case IP6OPT_TYPE_DISCARD: /* silently discard */ 941 m_freem(m); 942 return (-1); 943 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 944 ip6stat.ip6s_badoptions++; 945 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 946 return (-1); 947 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 948 ip6stat.ip6s_badoptions++; 949 ip6 = mtod(m, struct ip6_hdr *); 950 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 951 (m->m_flags & (M_BCAST|M_MCAST))) 952 m_freem(m); 953 else 954 icmp6_error(m, ICMP6_PARAM_PROB, 955 ICMP6_PARAMPROB_OPTION, off); 956 return (-1); 957 } 958 959 m_freem(m); /* XXX: NOTREACHED */ 960 return (-1); 961 } 962 963 /* 964 * Create the "control" list for this pcb. 965 * 966 * The routine will be called from upper layer handlers like tcp6_input(). 967 * Thus the routine assumes that the caller (tcp6_input) have already 968 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 969 * very first mbuf on the mbuf chain. 970 * We may want to add some infinite loop prevention or sanity checks for safety. 971 * (This applies only when you are using KAME mbuf chain restriction, i.e. 972 * you are using IP6_EXTHDR_CHECK() not m_pulldown()) 973 */ 974 void 975 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 976 { 977 #define IS2292(x, y) ((in6p->inp_flags & IN6P_RFC2292) ? (x) : (y)) 978 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 979 980 #ifdef SO_TIMESTAMP 981 if (in6p->inp_socket->so_options & SO_TIMESTAMP) { 982 struct timeval tv; 983 984 microtime(&tv); 985 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 986 SCM_TIMESTAMP, SOL_SOCKET); 987 if (*mp) 988 mp = &(*mp)->m_next; 989 } 990 #endif 991 992 /* RFC 2292 sec. 5 */ 993 if ((in6p->inp_flags & IN6P_PKTINFO) != 0) { 994 struct in6_pktinfo pi6; 995 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 996 if (IN6_IS_SCOPE_EMBED(&pi6.ipi6_addr)) 997 pi6.ipi6_addr.s6_addr16[1] = 0; 998 pi6.ipi6_ifindex = 999 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1000 *mp = sbcreatecontrol((caddr_t) &pi6, 1001 sizeof(struct in6_pktinfo), 1002 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1003 if (*mp) 1004 mp = &(*mp)->m_next; 1005 } 1006 1007 if ((in6p->inp_flags & IN6P_HOPLIMIT) != 0) { 1008 int hlim = ip6->ip6_hlim & 0xff; 1009 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1010 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1011 if (*mp) 1012 mp = &(*mp)->m_next; 1013 } 1014 1015 if ((in6p->inp_flags & IN6P_TCLASS) != 0) { 1016 u_int32_t flowinfo; 1017 int tclass; 1018 1019 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1020 flowinfo >>= 20; 1021 1022 tclass = flowinfo & 0xff; 1023 *mp = sbcreatecontrol((caddr_t)&tclass, sizeof(tclass), 1024 IPV6_TCLASS, IPPROTO_IPV6); 1025 if (*mp) 1026 mp = &(*mp)->m_next; 1027 } 1028 1029 /* 1030 * IPV6_HOPOPTS socket option. Recall that we required super-user 1031 * privilege for the option (see ip6_ctloutput), but it might be too 1032 * strict, since there might be some hop-by-hop options which can be 1033 * returned to normal user. 1034 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1035 */ 1036 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1037 /* 1038 * Check if a hop-by-hop options header is contatined in the 1039 * received packet, and if so, store the options as ancillary 1040 * data. Note that a hop-by-hop options header must be 1041 * just after the IPv6 header, which is assured through the 1042 * IPv6 input processing. 1043 */ 1044 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1045 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1046 struct ip6_hbh *hbh; 1047 int hbhlen = 0; 1048 struct mbuf *ext; 1049 1050 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1051 ip6->ip6_nxt); 1052 if (ext == NULL) { 1053 ip6stat.ip6s_tooshort++; 1054 return; 1055 } 1056 hbh = mtod(ext, struct ip6_hbh *); 1057 hbhlen = (hbh->ip6h_len + 1) << 3; 1058 if (hbhlen != ext->m_len) { 1059 m_freem(ext); 1060 ip6stat.ip6s_tooshort++; 1061 return; 1062 } 1063 1064 /* 1065 * XXX: We copy the whole header even if a 1066 * jumbo payload option is included, the option which 1067 * is to be removed before returning according to 1068 * RFC2292. 1069 * Note: this constraint is removed in RFC3542. 1070 */ 1071 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1072 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1073 IPPROTO_IPV6); 1074 if (*mp) 1075 mp = &(*mp)->m_next; 1076 m_freem(ext); 1077 } 1078 } 1079 1080 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1081 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1082 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1083 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1084 1085 /* 1086 * Search for destination options headers or routing 1087 * header(s) through the header chain, and stores each 1088 * header as ancillary data. 1089 * Note that the order of the headers remains in 1090 * the chain of ancillary data. 1091 */ 1092 while (1) { /* is explicit loop prevention necessary? */ 1093 struct ip6_ext *ip6e = NULL; 1094 int elen; 1095 struct mbuf *ext = NULL; 1096 1097 /* 1098 * if it is not an extension header, don't try to 1099 * pull it from the chain. 1100 */ 1101 switch (nxt) { 1102 case IPPROTO_DSTOPTS: 1103 case IPPROTO_ROUTING: 1104 case IPPROTO_HOPOPTS: 1105 case IPPROTO_AH: /* is it possible? */ 1106 break; 1107 default: 1108 goto loopend; 1109 } 1110 1111 ext = ip6_pullexthdr(m, off, nxt); 1112 if (ext == NULL) { 1113 ip6stat.ip6s_tooshort++; 1114 return; 1115 } 1116 ip6e = mtod(ext, struct ip6_ext *); 1117 if (nxt == IPPROTO_AH) 1118 elen = (ip6e->ip6e_len + 2) << 2; 1119 else 1120 elen = (ip6e->ip6e_len + 1) << 3; 1121 if (elen != ext->m_len) { 1122 m_freem(ext); 1123 ip6stat.ip6s_tooshort++; 1124 return; 1125 } 1126 1127 switch (nxt) { 1128 case IPPROTO_DSTOPTS: 1129 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1130 break; 1131 1132 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1133 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1134 IPPROTO_IPV6); 1135 if (*mp) 1136 mp = &(*mp)->m_next; 1137 break; 1138 1139 case IPPROTO_ROUTING: 1140 if (!(in6p->inp_flags & IN6P_RTHDR)) 1141 break; 1142 1143 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1144 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1145 IPPROTO_IPV6); 1146 if (*mp) 1147 mp = &(*mp)->m_next; 1148 break; 1149 1150 case IPPROTO_HOPOPTS: 1151 case IPPROTO_AH: /* is it possible? */ 1152 break; 1153 1154 default: 1155 /* 1156 * other cases have been filtered in the above. 1157 * none will visit this case. here we supply 1158 * the code just in case (nxt overwritten or 1159 * other cases). 1160 */ 1161 m_freem(ext); 1162 goto loopend; 1163 1164 } 1165 1166 /* proceed with the next header. */ 1167 off += elen; 1168 nxt = ip6e->ip6e_nxt; 1169 ip6e = NULL; 1170 m_freem(ext); 1171 ext = NULL; 1172 } 1173 loopend: 1174 ; 1175 } 1176 } 1177 1178 /* 1179 * pull single extension header from mbuf chain. returns single mbuf that 1180 * contains the result, or NULL on error. 1181 */ 1182 struct mbuf * 1183 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1184 { 1185 struct ip6_ext ip6e; 1186 size_t elen; 1187 struct mbuf *n; 1188 1189 #ifdef DIAGNOSTIC 1190 switch (nxt) { 1191 case IPPROTO_DSTOPTS: 1192 case IPPROTO_ROUTING: 1193 case IPPROTO_HOPOPTS: 1194 case IPPROTO_AH: /* is it possible? */ 1195 break; 1196 default: 1197 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1198 } 1199 #endif 1200 1201 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1202 if (nxt == IPPROTO_AH) 1203 elen = (ip6e.ip6e_len + 2) << 2; 1204 else 1205 elen = (ip6e.ip6e_len + 1) << 3; 1206 1207 MGET(n, M_DONTWAIT, MT_DATA); 1208 if (n && elen >= MLEN) { 1209 MCLGET(n, M_DONTWAIT); 1210 if ((n->m_flags & M_EXT) == 0) { 1211 m_free(n); 1212 n = NULL; 1213 } 1214 } 1215 if (!n) 1216 return NULL; 1217 1218 n->m_len = 0; 1219 if (elen >= M_TRAILINGSPACE(n)) { 1220 m_free(n); 1221 return NULL; 1222 } 1223 1224 m_copydata(m, off, elen, mtod(n, caddr_t)); 1225 n->m_len = elen; 1226 return n; 1227 } 1228 1229 /* 1230 * Get pointer to the previous header followed by the header 1231 * currently processed. 1232 * XXX: This function supposes that 1233 * M includes all headers, 1234 * the next header field and the header length field of each header 1235 * are valid, and 1236 * the sum of each header length equals to OFF. 1237 * Because of these assumptions, this function must be called very 1238 * carefully. Moreover, it will not be used in the near future when 1239 * we develop `neater' mechanism to process extension headers. 1240 */ 1241 u_int8_t * 1242 ip6_get_prevhdr(struct mbuf *m, int off) 1243 { 1244 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1245 1246 if (off == sizeof(struct ip6_hdr)) 1247 return (&ip6->ip6_nxt); 1248 else { 1249 int len, nxt; 1250 struct ip6_ext *ip6e = NULL; 1251 1252 nxt = ip6->ip6_nxt; 1253 len = sizeof(struct ip6_hdr); 1254 while (len < off) { 1255 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1256 1257 switch (nxt) { 1258 case IPPROTO_FRAGMENT: 1259 len += sizeof(struct ip6_frag); 1260 break; 1261 case IPPROTO_AH: 1262 len += (ip6e->ip6e_len + 2) << 2; 1263 break; 1264 default: 1265 len += (ip6e->ip6e_len + 1) << 3; 1266 break; 1267 } 1268 nxt = ip6e->ip6e_nxt; 1269 } 1270 if (ip6e) 1271 return (&ip6e->ip6e_nxt); 1272 else 1273 return NULL; 1274 } 1275 } 1276 1277 /* 1278 * get next header offset. m will be retained. 1279 */ 1280 int 1281 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1282 { 1283 struct ip6_hdr ip6; 1284 struct ip6_ext ip6e; 1285 struct ip6_frag fh; 1286 1287 /* just in case */ 1288 if (m == NULL) 1289 panic("ip6_nexthdr: m == NULL"); 1290 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1291 return -1; 1292 1293 switch (proto) { 1294 case IPPROTO_IPV6: 1295 if (m->m_pkthdr.len < off + sizeof(ip6)) 1296 return -1; 1297 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1298 if (nxtp) 1299 *nxtp = ip6.ip6_nxt; 1300 off += sizeof(ip6); 1301 return off; 1302 1303 case IPPROTO_FRAGMENT: 1304 /* 1305 * terminate parsing if it is not the first fragment, 1306 * it does not make sense to parse through it. 1307 */ 1308 if (m->m_pkthdr.len < off + sizeof(fh)) 1309 return -1; 1310 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1311 if ((fh.ip6f_offlg & IP6F_OFF_MASK) != 0) 1312 return -1; 1313 if (nxtp) 1314 *nxtp = fh.ip6f_nxt; 1315 off += sizeof(struct ip6_frag); 1316 return off; 1317 1318 case IPPROTO_AH: 1319 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1320 return -1; 1321 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1322 if (nxtp) 1323 *nxtp = ip6e.ip6e_nxt; 1324 off += (ip6e.ip6e_len + 2) << 2; 1325 if (m->m_pkthdr.len < off) 1326 return -1; 1327 return off; 1328 1329 case IPPROTO_HOPOPTS: 1330 case IPPROTO_ROUTING: 1331 case IPPROTO_DSTOPTS: 1332 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1333 return -1; 1334 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1335 if (nxtp) 1336 *nxtp = ip6e.ip6e_nxt; 1337 off += (ip6e.ip6e_len + 1) << 3; 1338 if (m->m_pkthdr.len < off) 1339 return -1; 1340 return off; 1341 1342 case IPPROTO_NONE: 1343 case IPPROTO_ESP: 1344 case IPPROTO_IPCOMP: 1345 /* give up */ 1346 return -1; 1347 1348 default: 1349 return -1; 1350 } 1351 1352 return -1; 1353 } 1354 1355 /* 1356 * get offset for the last header in the chain. m will be kept untainted. 1357 */ 1358 int 1359 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1360 { 1361 int newoff; 1362 int nxt; 1363 1364 if (!nxtp) { 1365 nxt = -1; 1366 nxtp = &nxt; 1367 } 1368 while (1) { 1369 newoff = ip6_nexthdr(m, off, proto, nxtp); 1370 if (newoff < 0) 1371 return off; 1372 else if (newoff < off) 1373 return -1; /* invalid */ 1374 else if (newoff == off) 1375 return newoff; 1376 1377 off = newoff; 1378 proto = *nxtp; 1379 } 1380 } 1381 1382 /* 1383 * System control for IP6 1384 */ 1385 1386 u_char inet6ctlerrmap[PRC_NCMDS] = { 1387 0, 0, 0, 0, 1388 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1389 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1390 EMSGSIZE, EHOSTUNREACH, 0, 0, 1391 0, 0, 0, 0, 1392 ENOPROTOOPT 1393 }; 1394 1395 int *ipv6ctl_vars[IPV6CTL_MAXID] = IPV6CTL_VARS; 1396 1397 int 1398 ip6_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, 1399 void *newp, size_t newlen) 1400 { 1401 #ifdef MROUTING 1402 extern int ip6_mrtproto; 1403 extern struct mrt6stat mrt6stat; 1404 #endif 1405 int error, s; 1406 1407 /* All sysctl names at this level are terminal. */ 1408 if (namelen != 1) 1409 return ENOTDIR; 1410 1411 switch (name[0]) { 1412 case IPV6CTL_V6ONLY: 1413 return sysctl_rdint(oldp, oldlenp, newp, ip6_v6only); 1414 case IPV6CTL_DAD_PENDING: 1415 return sysctl_rdint(oldp, oldlenp, newp, ip6_dad_pending); 1416 case IPV6CTL_STATS: 1417 if (newp != NULL) 1418 return (EPERM); 1419 return (sysctl_struct(oldp, oldlenp, newp, newlen, 1420 &ip6stat, sizeof(ip6stat))); 1421 case IPV6CTL_MRTSTATS: 1422 #ifdef MROUTING 1423 if (newp != NULL) 1424 return (EPERM); 1425 return (sysctl_struct(oldp, oldlenp, newp, newlen, 1426 &mrt6stat, sizeof(mrt6stat))); 1427 #else 1428 return (EOPNOTSUPP); 1429 #endif 1430 case IPV6CTL_MRTPROTO: 1431 #ifdef MROUTING 1432 return sysctl_rdint(oldp, oldlenp, newp, ip6_mrtproto); 1433 #else 1434 return (EOPNOTSUPP); 1435 #endif 1436 case IPV6CTL_MTUDISCTIMEOUT: 1437 error = sysctl_int(oldp, oldlenp, newp, newlen, 1438 &ip6_mtudisc_timeout); 1439 if (icmp6_mtudisc_timeout_q != NULL) { 1440 s = splsoftnet(); 1441 rt_timer_queue_change(icmp6_mtudisc_timeout_q, 1442 ip6_mtudisc_timeout); 1443 splx(s); 1444 } 1445 return (error); 1446 default: 1447 if (name[0] < IPV6CTL_MAXID) 1448 return (sysctl_int_arr(ipv6ctl_vars, name, namelen, 1449 oldp, oldlenp, newp, newlen)); 1450 return (EOPNOTSUPP); 1451 } 1452 /* NOTREACHED */ 1453 } 1454