1 /* $OpenBSD: ip6_input.c,v 1.266 2024/07/19 16:58:32 bluhm 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 #include <sys/task.h> 81 82 #include <net/if.h> 83 #include <net/if_var.h> 84 #include <net/if_types.h> 85 #include <net/route.h> 86 #include <net/netisr.h> 87 88 #include <netinet/in.h> 89 90 #include <netinet/ip.h> 91 92 #include <netinet/in_pcb.h> 93 #include <netinet/ip_var.h> 94 #include <netinet6/in6_var.h> 95 #include <netinet6/in6_ifattach.h> 96 #include <netinet/ip6.h> 97 #include <netinet6/ip6_var.h> 98 #include <netinet/icmp6.h> 99 #include <netinet6/nd6.h> 100 101 #include "gif.h" 102 #include "bpfilter.h" 103 104 #ifdef MROUTING 105 #include <netinet6/ip6_mroute.h> 106 #endif 107 108 #if NPF > 0 109 #include <net/pfvar.h> 110 #endif 111 112 #if NCARP > 0 113 #include <netinet/ip_carp.h> 114 #endif 115 116 struct niqueue ip6intrq = NIQUEUE_INITIALIZER(IPQ_MAXLEN, NETISR_IPV6); 117 118 struct cpumem *ip6counters; 119 120 uint8_t ip6_soiikey[IP6_SOIIKEY_LEN]; 121 122 int ip6_ours(struct mbuf **, int *, int, int, int); 123 int ip6_check_rh0hdr(struct mbuf *, int *); 124 int ip6_hbhchcheck(struct mbuf **, int *, int *, int); 125 int ip6_hopopts_input(struct mbuf **, int *, u_int32_t *, u_int32_t *); 126 struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 127 int ip6_sysctl_soiikey(void *, size_t *, void *, size_t); 128 129 static struct mbuf_queue ip6send_mq; 130 131 static void ip6_send_dispatch(void *); 132 static struct task ip6send_task = 133 TASK_INITIALIZER(ip6_send_dispatch, &ip6send_mq); 134 135 /* 136 * IP6 initialization: fill in IP6 protocol switch table. 137 * All protocols not implemented in kernel go to raw IP6 protocol handler. 138 */ 139 void 140 ip6_init(void) 141 { 142 const struct protosw *pr; 143 int i; 144 145 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 146 if (pr == NULL) 147 panic("%s", __func__); 148 for (i = 0; i < IPPROTO_MAX; i++) 149 ip6_protox[i] = pr - inet6sw; 150 for (pr = inet6domain.dom_protosw; 151 pr < inet6domain.dom_protoswNPROTOSW; pr++) 152 if (pr->pr_domain->dom_family == PF_INET6 && 153 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW && 154 pr->pr_protocol < IPPROTO_MAX) 155 ip6_protox[pr->pr_protocol] = pr - inet6sw; 156 ip6_randomid_init(); 157 nd6_init(); 158 frag6_init(); 159 160 mq_init(&ip6send_mq, 64, IPL_SOFTNET); 161 162 ip6counters = counters_alloc(ip6s_ncounters); 163 #ifdef MROUTING 164 rt_timer_queue_init(&ip6_mrouterq, MCAST_EXPIRE_TIMEOUT, 165 &mf6c_expire_route); 166 #endif 167 } 168 169 /* 170 * Enqueue packet for local delivery. Queuing is used as a boundary 171 * between the network layer (input/forward path) running with 172 * NET_LOCK_SHARED() and the transport layer needing it exclusively. 173 */ 174 int 175 ip6_ours(struct mbuf **mp, int *offp, int nxt, int af, int flags) 176 { 177 /* ip6_hbhchcheck() may be run before, then off and nxt are set */ 178 if (*offp == 0) { 179 nxt = ip6_hbhchcheck(mp, offp, NULL, flags); 180 if (nxt == IPPROTO_DONE) 181 return IPPROTO_DONE; 182 } 183 184 /* We are already in a IPv4/IPv6 local deliver loop. */ 185 if (af != AF_UNSPEC) 186 return nxt; 187 188 nxt = ip_deliver(mp, offp, nxt, AF_INET6, 1); 189 if (nxt == IPPROTO_DONE) 190 return IPPROTO_DONE; 191 192 /* save values for later, use after dequeue */ 193 if (*offp != sizeof(struct ip6_hdr)) { 194 struct m_tag *mtag; 195 struct ipoffnxt *ion; 196 197 /* mbuf tags are expensive, but only used for header options */ 198 mtag = m_tag_get(PACKET_TAG_IP6_OFFNXT, sizeof(*ion), 199 M_NOWAIT); 200 if (mtag == NULL) { 201 ip6stat_inc(ip6s_idropped); 202 m_freemp(mp); 203 return IPPROTO_DONE; 204 } 205 ion = (struct ipoffnxt *)(mtag + 1); 206 ion->ion_off = *offp; 207 ion->ion_nxt = nxt; 208 209 m_tag_prepend(*mp, mtag); 210 } 211 212 niq_enqueue(&ip6intrq, *mp); 213 *mp = NULL; 214 return IPPROTO_DONE; 215 } 216 217 /* 218 * Dequeue and process locally delivered packets. 219 * This is called with exclusive NET_LOCK(). 220 */ 221 void 222 ip6intr(void) 223 { 224 struct mbuf *m; 225 226 while ((m = niq_dequeue(&ip6intrq)) != NULL) { 227 struct m_tag *mtag; 228 int off, nxt; 229 230 #ifdef DIAGNOSTIC 231 if ((m->m_flags & M_PKTHDR) == 0) 232 panic("ip6intr no HDR"); 233 #endif 234 mtag = m_tag_find(m, PACKET_TAG_IP6_OFFNXT, NULL); 235 if (mtag != NULL) { 236 struct ipoffnxt *ion; 237 238 ion = (struct ipoffnxt *)(mtag + 1); 239 off = ion->ion_off; 240 nxt = ion->ion_nxt; 241 242 m_tag_delete(m, mtag); 243 } else { 244 struct ip6_hdr *ip6; 245 246 ip6 = mtod(m, struct ip6_hdr *); 247 off = sizeof(struct ip6_hdr); 248 nxt = ip6->ip6_nxt; 249 } 250 nxt = ip_deliver(&m, &off, nxt, AF_INET6, 0); 251 KASSERT(nxt == IPPROTO_DONE); 252 } 253 } 254 255 void 256 ipv6_input(struct ifnet *ifp, struct mbuf *m) 257 { 258 int off, nxt; 259 260 off = 0; 261 nxt = ip6_input_if(&m, &off, IPPROTO_IPV6, AF_UNSPEC, ifp); 262 KASSERT(nxt == IPPROTO_DONE); 263 } 264 265 struct mbuf * 266 ipv6_check(struct ifnet *ifp, struct mbuf *m) 267 { 268 struct ip6_hdr *ip6; 269 270 if (m->m_len < sizeof(*ip6)) { 271 m = m_pullup(m, sizeof(*ip6)); 272 if (m == NULL) { 273 ip6stat_inc(ip6s_toosmall); 274 return (NULL); 275 } 276 } 277 278 ip6 = mtod(m, struct ip6_hdr *); 279 280 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 281 ip6stat_inc(ip6s_badvers); 282 goto bad; 283 } 284 285 /* 286 * Check against address spoofing/corruption. 287 */ 288 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 289 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 290 /* 291 * XXX: "badscope" is not very suitable for a multicast source. 292 */ 293 ip6stat_inc(ip6s_badscope); 294 goto bad; 295 } 296 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 297 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 298 (ifp->if_flags & IFF_LOOPBACK) == 0) { 299 ip6stat_inc(ip6s_badscope); 300 goto bad; 301 } 302 /* Drop packets if interface ID portion is already filled. */ 303 if (((IN6_IS_SCOPE_EMBED(&ip6->ip6_src) && ip6->ip6_src.s6_addr16[1]) || 304 (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst) && ip6->ip6_dst.s6_addr16[1])) && 305 (ifp->if_flags & IFF_LOOPBACK) == 0) { 306 ip6stat_inc(ip6s_badscope); 307 goto bad; 308 } 309 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 310 !(m->m_flags & M_LOOP)) { 311 /* 312 * In this case, the packet should come from the loopback 313 * interface. However, we cannot just check the if_flags, 314 * because ip6_mloopback() passes the "actual" interface 315 * as the outgoing/incoming interface. 316 */ 317 ip6stat_inc(ip6s_badscope); 318 goto bad; 319 } 320 321 /* 322 * The following check is not documented in specs. A malicious 323 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 324 * and bypass security checks (act as if it was from 127.0.0.1 by using 325 * IPv6 src ::ffff:127.0.0.1). Be cautious. 326 * 327 * This check chokes if we are in an SIIT cloud. As none of BSDs 328 * support IPv4-less kernel compilation, we cannot support SIIT 329 * environment at all. So, it makes more sense for us to reject any 330 * malicious packets for non-SIIT environment, than try to do a 331 * partial support for SIIT environment. 332 */ 333 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 334 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 335 ip6stat_inc(ip6s_badscope); 336 goto bad; 337 } 338 339 /* 340 * Reject packets with IPv4 compatible addresses (auto tunnel). 341 * 342 * The code forbids automatic tunneling as per RFC4213. 343 */ 344 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 345 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 346 ip6stat_inc(ip6s_badscope); 347 goto bad; 348 } 349 350 return (m); 351 bad: 352 m_freem(m); 353 return (NULL); 354 } 355 356 int 357 ip6_input_if(struct mbuf **mp, int *offp, int nxt, int af, struct ifnet *ifp) 358 { 359 struct route ro; 360 struct mbuf *m; 361 struct ip6_hdr *ip6; 362 struct rtentry *rt; 363 int ours = 0; 364 u_int16_t src_scope, dst_scope; 365 #if NPF > 0 366 struct in6_addr odst; 367 #endif 368 int flags = 0; 369 370 KASSERT(*offp == 0); 371 372 ro.ro_rt = NULL; 373 ip6stat_inc(ip6s_total); 374 m = *mp = ipv6_check(ifp, *mp); 375 if (m == NULL) 376 goto bad; 377 378 ip6 = mtod(m, struct ip6_hdr *); 379 380 #if NCARP > 0 381 if (carp_lsdrop(ifp, m, AF_INET6, ip6->ip6_src.s6_addr32, 382 ip6->ip6_dst.s6_addr32, (ip6->ip6_nxt == IPPROTO_ICMPV6 ? 0 : 1))) 383 goto bad; 384 #endif 385 ip6stat_inc(ip6s_nxthist + ip6->ip6_nxt); 386 387 /* 388 * If the packet has been received on a loopback interface it 389 * can be destined to any local address, not necessarily to 390 * an address configured on `ifp'. 391 */ 392 if (ifp->if_flags & IFF_LOOPBACK) { 393 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) { 394 src_scope = ip6->ip6_src.s6_addr16[1]; 395 ip6->ip6_src.s6_addr16[1] = 0; 396 } 397 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) { 398 dst_scope = ip6->ip6_dst.s6_addr16[1]; 399 ip6->ip6_dst.s6_addr16[1] = 0; 400 } 401 } 402 403 #if NPF > 0 404 /* 405 * Packet filter 406 */ 407 odst = ip6->ip6_dst; 408 if (pf_test(AF_INET6, PF_IN, ifp, mp) != PF_PASS) 409 goto bad; 410 m = *mp; 411 if (m == NULL) 412 goto bad; 413 414 ip6 = mtod(m, struct ip6_hdr *); 415 if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) 416 SET(flags, IPV6_REDIRECT); 417 #endif 418 419 switch (atomic_load_int(&ip6_forwarding)) { 420 case 2: 421 SET(flags, IPV6_FORWARDING_IPSEC); 422 /* FALLTHROUGH */ 423 case 1: 424 SET(flags, IPV6_FORWARDING); 425 break; 426 } 427 428 /* 429 * Without embedded scope ID we cannot find link-local 430 * addresses in the routing table. 431 */ 432 if (ifp->if_flags & IFF_LOOPBACK) { 433 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) 434 ip6->ip6_src.s6_addr16[1] = src_scope; 435 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) 436 ip6->ip6_dst.s6_addr16[1] = dst_scope; 437 } else { 438 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) 439 ip6->ip6_src.s6_addr16[1] = htons(ifp->if_index); 440 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) 441 ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); 442 } 443 444 /* 445 * Be more secure than RFC5095 and scan for type 0 routing headers. 446 * If pf has already scanned the header chain, do not do it twice. 447 */ 448 if (!(m->m_pkthdr.pf.flags & PF_TAG_PROCESSED) && 449 ip6_check_rh0hdr(m, offp)) { 450 ip6stat_inc(ip6s_badoptions); 451 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, *offp); 452 m = *mp = NULL; 453 goto bad; 454 } 455 456 #if NPF > 0 457 if (pf_ouraddr(m) == 1) { 458 nxt = ip6_ours(mp, offp, nxt, af, flags); 459 goto out; 460 } 461 #endif 462 463 /* 464 * Multicast check 465 */ 466 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 467 /* 468 * Make sure M_MCAST is set. It should theoretically 469 * already be there, but let's play safe because upper 470 * layers check for this flag. 471 */ 472 m->m_flags |= M_MCAST; 473 474 /* 475 * See if we belong to the destination multicast group on the 476 * arrival interface. 477 */ 478 if (in6_hasmulti(&ip6->ip6_dst, ifp)) 479 ours = 1; 480 481 #ifdef MROUTING 482 if (ip6_mforwarding && ip6_mrouter[ifp->if_rdomain]) { 483 int error; 484 485 nxt = ip6_hbhchcheck(&m, offp, &ours, flags); 486 if (nxt == IPPROTO_DONE) 487 goto out; 488 489 ip6 = mtod(m, struct ip6_hdr *); 490 491 /* 492 * If we are acting as a multicast router, all 493 * incoming multicast packets are passed to the 494 * kernel-level multicast forwarding function. 495 * The packet is returned (relatively) intact; if 496 * ip6_mforward() returns a non-zero value, the packet 497 * must be discarded, else it may be accepted below. 498 */ 499 KERNEL_LOCK(); 500 error = ip6_mforward(ip6, ifp, m, flags); 501 KERNEL_UNLOCK(); 502 if (error) { 503 ip6stat_inc(ip6s_cantforward); 504 goto bad; 505 } 506 507 if (ours) { 508 if (af == AF_UNSPEC) 509 nxt = ip6_ours(mp, offp, nxt, af, 510 flags); 511 goto out; 512 } 513 goto bad; 514 } 515 #endif 516 if (!ours) { 517 ip6stat_inc(ip6s_notmember); 518 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 519 ip6stat_inc(ip6s_cantforward); 520 goto bad; 521 } 522 nxt = ip6_ours(mp, offp, nxt, af, flags); 523 goto out; 524 } 525 526 527 /* 528 * Unicast check 529 */ 530 rt = route6_mpath(&ro, &ip6->ip6_dst, &ip6->ip6_src, 531 m->m_pkthdr.ph_rtableid); 532 533 /* 534 * Accept the packet if the route to the destination is marked 535 * as local. 536 */ 537 if (rt != NULL && ISSET(rt->rt_flags, RTF_LOCAL)) { 538 struct in6_ifaddr *ia6 = ifatoia6(rt->rt_ifa); 539 540 if (!ISSET(flags, IPV6_FORWARDING) && 541 rt->rt_ifidx != ifp->if_index && 542 !((ifp->if_flags & IFF_LOOPBACK) || 543 (ifp->if_type == IFT_ENC) || 544 (m->m_pkthdr.pf.flags & PF_TAG_TRANSLATE_LOCALHOST))) { 545 /* received on wrong interface */ 546 #if NCARP > 0 547 struct ifnet *out_if; 548 549 /* 550 * Virtual IPs on carp interfaces need to be checked 551 * also against the parent interface and other carp 552 * interfaces sharing the same parent. 553 */ 554 out_if = if_get(rt->rt_ifidx); 555 if (!(out_if && carp_strict_addr_chk(out_if, ifp))) { 556 ip6stat_inc(ip6s_wrongif); 557 if_put(out_if); 558 goto bad; 559 } 560 if_put(out_if); 561 #else 562 ip6stat_inc(ip6s_wrongif); 563 goto bad; 564 #endif 565 } 566 /* 567 * packets to a tentative, duplicated, or somehow invalid 568 * address must not be accepted. 569 */ 570 if ((ia6->ia6_flags & (IN6_IFF_TENTATIVE|IN6_IFF_DUPLICATED))) { 571 char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; 572 573 inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)); 574 inet_ntop(AF_INET6, &ip6->ip6_dst, dst, sizeof(dst)); 575 /* address is not ready, so discard the packet. */ 576 nd6log((LOG_INFO, 577 "%s: packet to an unready address %s->%s\n", 578 __func__, src, dst)); 579 580 goto bad; 581 } else { 582 nxt = ip6_ours(mp, offp, nxt, af, flags); 583 goto out; 584 } 585 } 586 587 #if NCARP > 0 588 if (ip6->ip6_nxt == IPPROTO_ICMPV6 && 589 carp_lsdrop(ifp, m, AF_INET6, ip6->ip6_src.s6_addr32, 590 ip6->ip6_dst.s6_addr32, 1)) 591 goto bad; 592 #endif 593 /* 594 * Now there is no reason to process the packet if it's not our own 595 * and we're not a router. 596 */ 597 if (!ISSET(flags, IPV6_FORWARDING)) { 598 ip6stat_inc(ip6s_cantforward); 599 goto bad; 600 } 601 602 nxt = ip6_hbhchcheck(&m, offp, &ours, flags); 603 if (nxt == IPPROTO_DONE) 604 goto out; 605 606 if (ours) { 607 if (af == AF_UNSPEC) 608 nxt = ip6_ours(mp, offp, nxt, af, flags); 609 goto out; 610 } 611 612 #ifdef IPSEC 613 if (ipsec_in_use) { 614 int rv; 615 616 rv = ipsec_forward_check(m, *offp, AF_INET6); 617 if (rv != 0) { 618 ip6stat_inc(ip6s_cantforward); 619 goto bad; 620 } 621 /* 622 * Fall through, forward packet. Outbound IPsec policy 623 * checking will occur in ip6_forward(). 624 */ 625 } 626 #endif /* IPSEC */ 627 628 ip6_forward(m, &ro, flags); 629 *mp = NULL; 630 rtfree(ro.ro_rt); 631 return IPPROTO_DONE; 632 bad: 633 nxt = IPPROTO_DONE; 634 m_freemp(mp); 635 out: 636 rtfree(ro.ro_rt); 637 return nxt; 638 } 639 640 /* On error free mbuf and return IPPROTO_DONE. */ 641 int 642 ip6_hbhchcheck(struct mbuf **mp, int *offp, int *oursp, int flags) 643 { 644 struct ip6_hdr *ip6; 645 u_int32_t plen, rtalert = ~0; 646 int nxt; 647 648 ip6 = mtod(*mp, struct ip6_hdr *); 649 650 /* 651 * Process Hop-by-Hop options header if it's contained. 652 * m may be modified in ip6_hopopts_input(). 653 * If a JumboPayload option is included, plen will also be modified. 654 */ 655 plen = (u_int32_t)ntohs(ip6->ip6_plen); 656 *offp = sizeof(struct ip6_hdr); 657 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 658 struct ip6_hbh *hbh; 659 660 if (ip6_hopopts_input(mp, offp, &plen, &rtalert)) 661 goto bad; /* m have already been freed */ 662 663 /* adjust pointer */ 664 ip6 = mtod(*mp, struct ip6_hdr *); 665 666 /* 667 * if the payload length field is 0 and the next header field 668 * indicates Hop-by-Hop Options header, then a Jumbo Payload 669 * option MUST be included. 670 */ 671 if (ip6->ip6_plen == 0 && plen == 0) { 672 /* 673 * Note that if a valid jumbo payload option is 674 * contained, ip6_hopopts_input() must set a valid 675 * (non-zero) payload length to the variable plen. 676 */ 677 ip6stat_inc(ip6s_badoptions); 678 icmp6_error(*mp, ICMP6_PARAM_PROB, 679 ICMP6_PARAMPROB_HEADER, 680 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 681 goto bad; 682 } 683 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, *mp, 684 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 685 if (hbh == NULL) { 686 ip6stat_inc(ip6s_tooshort); 687 goto bad; 688 } 689 nxt = hbh->ip6h_nxt; 690 691 /* 692 * accept the packet if a router alert option is included 693 * and we act as an IPv6 router. 694 */ 695 if (rtalert != ~0 && ISSET(flags, IPV6_FORWARDING) && 696 oursp != NULL) 697 *oursp = 1; 698 } else 699 nxt = ip6->ip6_nxt; 700 701 /* 702 * Check that the amount of data in the buffers 703 * is as at least much as the IPv6 header would have us expect. 704 * Trim mbufs if longer than we expect. 705 * Drop packet if shorter than we expect. 706 */ 707 if ((*mp)->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 708 ip6stat_inc(ip6s_tooshort); 709 m_freemp(mp); 710 goto bad; 711 } 712 if ((*mp)->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 713 if ((*mp)->m_len == (*mp)->m_pkthdr.len) { 714 (*mp)->m_len = sizeof(struct ip6_hdr) + plen; 715 (*mp)->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 716 } else { 717 m_adj((*mp), sizeof(struct ip6_hdr) + plen - 718 (*mp)->m_pkthdr.len); 719 } 720 } 721 722 return nxt; 723 bad: 724 return IPPROTO_DONE; 725 } 726 727 /* scan packet for RH0 routing header. Mostly stolen from pf.c:pf_test() */ 728 int 729 ip6_check_rh0hdr(struct mbuf *m, int *offp) 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 than one rh header present */ 744 *offp = off; 745 return (1); 746 } 747 748 if (off + sizeof(rthdr) > lim) { 749 /* packet to short to make sense */ 750 *offp = off; 751 return (1); 752 } 753 754 m_copydata(m, off, sizeof(rthdr), &rthdr); 755 756 if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) { 757 *offp = off + 758 offsetof(struct ip6_rthdr, ip6r_type); 759 return (1); 760 } 761 762 off += (rthdr.ip6r_len + 1) * 8; 763 proto = rthdr.ip6r_nxt; 764 break; 765 case IPPROTO_AH: 766 case IPPROTO_HOPOPTS: 767 case IPPROTO_DSTOPTS: 768 /* get next header and header length */ 769 if (off + sizeof(opt6) > lim) { 770 /* 771 * Packet to short to make sense, we could 772 * reject the packet but as a router we 773 * should not do that so forward it. 774 */ 775 return (0); 776 } 777 778 m_copydata(m, off, sizeof(opt6), &opt6); 779 780 if (proto == IPPROTO_AH) 781 off += (opt6.ip6e_len + 2) * 4; 782 else 783 off += (opt6.ip6e_len + 1) * 8; 784 proto = opt6.ip6e_nxt; 785 break; 786 case IPPROTO_FRAGMENT: 787 default: 788 /* end of header stack */ 789 done = 1; 790 break; 791 } 792 } while (!done); 793 794 return (0); 795 } 796 797 /* 798 * Hop-by-Hop options header processing. If a valid jumbo payload option is 799 * included, the real payload length will be stored in plenp. 800 * On error free mbuf and return -1. 801 * 802 * rtalertp - XXX: should be stored in a more smart way 803 */ 804 int 805 ip6_hopopts_input(struct mbuf **mp, int *offp, u_int32_t *plenp, 806 u_int32_t *rtalertp) 807 { 808 int off = *offp, hbhlen; 809 struct ip6_hbh *hbh; 810 811 /* validation of the length of the header */ 812 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, *mp, 813 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 814 if (hbh == NULL) { 815 ip6stat_inc(ip6s_tooshort); 816 return -1; 817 } 818 hbhlen = (hbh->ip6h_len + 1) << 3; 819 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, *mp, sizeof(struct ip6_hdr), 820 hbhlen); 821 if (hbh == NULL) { 822 ip6stat_inc(ip6s_tooshort); 823 return -1; 824 } 825 off += hbhlen; 826 hbhlen -= sizeof(struct ip6_hbh); 827 828 if (ip6_process_hopopts(mp, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 829 hbhlen, rtalertp, plenp) < 0) 830 return (-1); 831 832 *offp = off; 833 return (0); 834 } 835 836 /* 837 * Search header for all Hop-by-hop options and process each option. 838 * This function is separate from ip6_hopopts_input() in order to 839 * handle a case where the sending node itself process its hop-by-hop 840 * options header. In such a case, the function is called from ip6_output(). 841 * On error free mbuf and return -1. 842 * 843 * The function assumes that hbh header is located right after the IPv6 header 844 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 845 * opthead + hbhlen is located in continuous memory region. 846 */ 847 int 848 ip6_process_hopopts(struct mbuf **mp, u_int8_t *opthead, int hbhlen, 849 u_int32_t *rtalertp, u_int32_t *plenp) 850 { 851 struct ip6_hdr *ip6; 852 int optlen = 0; 853 u_int8_t *opt = opthead; 854 u_int16_t rtalert_val; 855 u_int32_t jumboplen; 856 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 857 858 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 859 switch (*opt) { 860 case IP6OPT_PAD1: 861 optlen = 1; 862 break; 863 case IP6OPT_PADN: 864 if (hbhlen < IP6OPT_MINLEN) { 865 ip6stat_inc(ip6s_toosmall); 866 goto bad; 867 } 868 optlen = *(opt + 1) + 2; 869 break; 870 case IP6OPT_ROUTER_ALERT: 871 /* XXX may need check for alignment */ 872 if (hbhlen < IP6OPT_RTALERT_LEN) { 873 ip6stat_inc(ip6s_toosmall); 874 goto bad; 875 } 876 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 877 /* XXX stat */ 878 icmp6_error(*mp, ICMP6_PARAM_PROB, 879 ICMP6_PARAMPROB_HEADER, 880 erroff + opt + 1 - opthead); 881 return (-1); 882 } 883 optlen = IP6OPT_RTALERT_LEN; 884 memcpy((caddr_t)&rtalert_val, (caddr_t)(opt + 2), 2); 885 *rtalertp = ntohs(rtalert_val); 886 break; 887 case IP6OPT_JUMBO: 888 /* XXX may need check for alignment */ 889 if (hbhlen < IP6OPT_JUMBO_LEN) { 890 ip6stat_inc(ip6s_toosmall); 891 goto bad; 892 } 893 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 894 /* XXX stat */ 895 icmp6_error(*mp, ICMP6_PARAM_PROB, 896 ICMP6_PARAMPROB_HEADER, 897 erroff + opt + 1 - opthead); 898 return (-1); 899 } 900 optlen = IP6OPT_JUMBO_LEN; 901 902 /* 903 * IPv6 packets that have non 0 payload length 904 * must not contain a jumbo payload option. 905 */ 906 ip6 = mtod(*mp, struct ip6_hdr *); 907 if (ip6->ip6_plen) { 908 ip6stat_inc(ip6s_badoptions); 909 icmp6_error(*mp, ICMP6_PARAM_PROB, 910 ICMP6_PARAMPROB_HEADER, 911 erroff + opt - opthead); 912 return (-1); 913 } 914 915 /* 916 * We may see jumbolen in unaligned location, so 917 * we'd need to perform memcpy(). 918 */ 919 memcpy(&jumboplen, opt + 2, sizeof(jumboplen)); 920 jumboplen = (u_int32_t)htonl(jumboplen); 921 922 #if 1 923 /* 924 * if there are multiple jumbo payload options, 925 * *plenp will be non-zero and the packet will be 926 * rejected. 927 * the behavior may need some debate in ipngwg - 928 * multiple options does not make sense, however, 929 * there's no explicit mention in specification. 930 */ 931 if (*plenp != 0) { 932 ip6stat_inc(ip6s_badoptions); 933 icmp6_error(*mp, ICMP6_PARAM_PROB, 934 ICMP6_PARAMPROB_HEADER, 935 erroff + opt + 2 - opthead); 936 return (-1); 937 } 938 #endif 939 940 /* 941 * jumbo payload length must be larger than 65535. 942 */ 943 if (jumboplen <= IPV6_MAXPACKET) { 944 ip6stat_inc(ip6s_badoptions); 945 icmp6_error(*mp, ICMP6_PARAM_PROB, 946 ICMP6_PARAMPROB_HEADER, 947 erroff + opt + 2 - opthead); 948 return (-1); 949 } 950 *plenp = jumboplen; 951 952 break; 953 default: /* unknown option */ 954 if (hbhlen < IP6OPT_MINLEN) { 955 ip6stat_inc(ip6s_toosmall); 956 goto bad; 957 } 958 optlen = ip6_unknown_opt(mp, opt, 959 erroff + opt - opthead); 960 if (optlen == -1) 961 return (-1); 962 optlen += 2; 963 break; 964 } 965 } 966 967 return (0); 968 969 bad: 970 m_freemp(mp); 971 return (-1); 972 } 973 974 /* 975 * Unknown option processing. 976 * The third argument `off' is the offset from the IPv6 header to the option, 977 * which allows returning an ICMPv6 error even if the IPv6 header and the 978 * option header are not continuous. 979 * On error free mbuf and return -1. 980 */ 981 int 982 ip6_unknown_opt(struct mbuf **mp, u_int8_t *optp, int off) 983 { 984 struct ip6_hdr *ip6; 985 986 switch (IP6OPT_TYPE(*optp)) { 987 case IP6OPT_TYPE_SKIP: /* ignore the option */ 988 return ((int)*(optp + 1)); 989 case IP6OPT_TYPE_DISCARD: /* silently discard */ 990 m_freemp(mp); 991 return (-1); 992 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 993 ip6stat_inc(ip6s_badoptions); 994 icmp6_error(*mp, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 995 return (-1); 996 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 997 ip6stat_inc(ip6s_badoptions); 998 ip6 = mtod(*mp, struct ip6_hdr *); 999 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1000 ((*mp)->m_flags & (M_BCAST|M_MCAST))) 1001 m_freemp(mp); 1002 else 1003 icmp6_error(*mp, ICMP6_PARAM_PROB, 1004 ICMP6_PARAMPROB_OPTION, off); 1005 return (-1); 1006 } 1007 1008 m_freemp(mp); /* XXX: NOTREACHED */ 1009 return (-1); 1010 } 1011 1012 /* 1013 * Create the "control" list for this pcb. 1014 * 1015 * The routine will be called from upper layer handlers like udp_input(). 1016 * Thus the routine assumes that the caller (udp_input) have already 1017 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1018 * very first mbuf on the mbuf chain. 1019 * We may want to add some infinite loop prevention or sanity checks for safety. 1020 * (This applies only when you are using KAME mbuf chain restriction, i.e. 1021 * you are using IP6_EXTHDR_CHECK() not m_pulldown()) 1022 */ 1023 void 1024 ip6_savecontrol(struct inpcb *inp, struct mbuf *m, struct mbuf **mp) 1025 { 1026 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1027 1028 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1029 struct timeval tv; 1030 1031 m_microtime(m, &tv); 1032 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1033 SCM_TIMESTAMP, SOL_SOCKET); 1034 if (*mp) 1035 mp = &(*mp)->m_next; 1036 } 1037 1038 /* RFC 2292 sec. 5 */ 1039 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1040 struct in6_pktinfo pi6; 1041 memcpy(&pi6.ipi6_addr, &ip6->ip6_dst, sizeof(struct in6_addr)); 1042 if (IN6_IS_SCOPE_EMBED(&pi6.ipi6_addr)) 1043 pi6.ipi6_addr.s6_addr16[1] = 0; 1044 pi6.ipi6_ifindex = m ? m->m_pkthdr.ph_ifidx : 0; 1045 *mp = sbcreatecontrol((caddr_t) &pi6, 1046 sizeof(struct in6_pktinfo), 1047 IPV6_PKTINFO, IPPROTO_IPV6); 1048 if (*mp) 1049 mp = &(*mp)->m_next; 1050 } 1051 1052 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1053 int hlim = ip6->ip6_hlim & 0xff; 1054 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1055 IPV6_HOPLIMIT, IPPROTO_IPV6); 1056 if (*mp) 1057 mp = &(*mp)->m_next; 1058 } 1059 1060 if ((inp->inp_flags & IN6P_TCLASS) != 0) { 1061 u_int32_t flowinfo; 1062 int tclass; 1063 1064 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1065 flowinfo >>= 20; 1066 1067 tclass = flowinfo & 0xff; 1068 *mp = sbcreatecontrol((caddr_t)&tclass, sizeof(tclass), 1069 IPV6_TCLASS, IPPROTO_IPV6); 1070 if (*mp) 1071 mp = &(*mp)->m_next; 1072 } 1073 1074 /* 1075 * IPV6_HOPOPTS socket option. Recall that we required super-user 1076 * privilege for the option (see ip6_ctloutput), but it might be too 1077 * strict, since there might be some hop-by-hop options which can be 1078 * returned to normal user. 1079 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1080 */ 1081 if ((inp->inp_flags & IN6P_HOPOPTS) != 0) { 1082 /* 1083 * Check if a hop-by-hop options header is contained in the 1084 * received packet, and if so, store the options as ancillary 1085 * data. Note that a hop-by-hop options header must be 1086 * just after the IPv6 header, which is assured through the 1087 * IPv6 input processing. 1088 */ 1089 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1090 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1091 struct ip6_hbh *hbh; 1092 int hbhlen = 0; 1093 struct mbuf *ext; 1094 1095 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1096 ip6->ip6_nxt); 1097 if (ext == NULL) { 1098 ip6stat_inc(ip6s_tooshort); 1099 return; 1100 } 1101 hbh = mtod(ext, struct ip6_hbh *); 1102 hbhlen = (hbh->ip6h_len + 1) << 3; 1103 if (hbhlen != ext->m_len) { 1104 m_freem(ext); 1105 ip6stat_inc(ip6s_tooshort); 1106 return; 1107 } 1108 1109 /* 1110 * XXX: We copy the whole header even if a 1111 * jumbo payload option is included, the option which 1112 * is to be removed before returning according to 1113 * RFC2292. 1114 * Note: this constraint is removed in RFC3542. 1115 */ 1116 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1117 IPV6_HOPOPTS, 1118 IPPROTO_IPV6); 1119 if (*mp) 1120 mp = &(*mp)->m_next; 1121 m_freem(ext); 1122 } 1123 } 1124 1125 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1126 if ((inp->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1127 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1128 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1129 1130 /* 1131 * Search for destination options headers or routing 1132 * header(s) through the header chain, and stores each 1133 * header as ancillary data. 1134 * Note that the order of the headers remains in 1135 * the chain of ancillary data. 1136 */ 1137 while (1) { /* is explicit loop prevention necessary? */ 1138 struct ip6_ext *ip6e = NULL; 1139 int elen; 1140 struct mbuf *ext = NULL; 1141 1142 /* 1143 * if it is not an extension header, don't try to 1144 * pull it from the chain. 1145 */ 1146 switch (nxt) { 1147 case IPPROTO_DSTOPTS: 1148 case IPPROTO_ROUTING: 1149 case IPPROTO_HOPOPTS: 1150 case IPPROTO_AH: /* is it possible? */ 1151 break; 1152 default: 1153 goto loopend; 1154 } 1155 1156 ext = ip6_pullexthdr(m, off, nxt); 1157 if (ext == NULL) { 1158 ip6stat_inc(ip6s_tooshort); 1159 return; 1160 } 1161 ip6e = mtod(ext, struct ip6_ext *); 1162 if (nxt == IPPROTO_AH) 1163 elen = (ip6e->ip6e_len + 2) << 2; 1164 else 1165 elen = (ip6e->ip6e_len + 1) << 3; 1166 if (elen != ext->m_len) { 1167 m_freem(ext); 1168 ip6stat_inc(ip6s_tooshort); 1169 return; 1170 } 1171 1172 switch (nxt) { 1173 case IPPROTO_DSTOPTS: 1174 if (!(inp->inp_flags & IN6P_DSTOPTS)) 1175 break; 1176 1177 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1178 IPV6_DSTOPTS, 1179 IPPROTO_IPV6); 1180 if (*mp) 1181 mp = &(*mp)->m_next; 1182 break; 1183 1184 case IPPROTO_ROUTING: 1185 if (!(inp->inp_flags & IN6P_RTHDR)) 1186 break; 1187 1188 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1189 IPV6_RTHDR, 1190 IPPROTO_IPV6); 1191 if (*mp) 1192 mp = &(*mp)->m_next; 1193 break; 1194 1195 case IPPROTO_HOPOPTS: 1196 case IPPROTO_AH: /* is it possible? */ 1197 break; 1198 1199 default: 1200 /* 1201 * other cases have been filtered in the above. 1202 * none will visit this case. here we supply 1203 * the code just in case (nxt overwritten or 1204 * other cases). 1205 */ 1206 m_freem(ext); 1207 goto loopend; 1208 1209 } 1210 1211 /* proceed with the next header. */ 1212 off += elen; 1213 nxt = ip6e->ip6e_nxt; 1214 ip6e = NULL; 1215 m_freem(ext); 1216 ext = NULL; 1217 } 1218 loopend: 1219 ; 1220 } 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 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 if (off + sizeof(ip6e) > m->m_pkthdr.len) 1247 return NULL; 1248 1249 m_copydata(m, off, sizeof(ip6e), &ip6e); 1250 if (nxt == IPPROTO_AH) 1251 elen = (ip6e.ip6e_len + 2) << 2; 1252 else 1253 elen = (ip6e.ip6e_len + 1) << 3; 1254 1255 if (off + elen > m->m_pkthdr.len) 1256 return NULL; 1257 1258 MGET(n, M_DONTWAIT, MT_DATA); 1259 if (n && elen >= MLEN) { 1260 MCLGET(n, M_DONTWAIT); 1261 if ((n->m_flags & M_EXT) == 0) { 1262 m_free(n); 1263 n = NULL; 1264 } 1265 } 1266 if (n == NULL) { 1267 ip6stat_inc(ip6s_idropped); 1268 return NULL; 1269 } 1270 1271 n->m_len = 0; 1272 if (elen >= m_trailingspace(n)) { 1273 m_free(n); 1274 return NULL; 1275 } 1276 1277 m_copydata(m, off, elen, mtod(n, caddr_t)); 1278 n->m_len = elen; 1279 return n; 1280 } 1281 1282 /* 1283 * Get offset to the previous header followed by the header 1284 * currently processed. 1285 */ 1286 int 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 offsetof(struct ip6_hdr, ip6_nxt); 1293 } else if (off < sizeof(struct ip6_hdr)) { 1294 panic("%s: off < sizeof(struct ip6_hdr)", __func__); 1295 } else { 1296 int len, nlen, nxt; 1297 struct ip6_ext ip6e; 1298 1299 nxt = ip6->ip6_nxt; 1300 len = sizeof(struct ip6_hdr); 1301 nlen = 0; 1302 while (len < off) { 1303 m_copydata(m, len, sizeof(ip6e), &ip6e); 1304 1305 switch (nxt) { 1306 case IPPROTO_FRAGMENT: 1307 nlen = sizeof(struct ip6_frag); 1308 break; 1309 case IPPROTO_AH: 1310 nlen = (ip6e.ip6e_len + 2) << 2; 1311 break; 1312 default: 1313 nlen = (ip6e.ip6e_len + 1) << 3; 1314 break; 1315 } 1316 len += nlen; 1317 nxt = ip6e.ip6e_nxt; 1318 } 1319 1320 return (len - nlen); 1321 } 1322 } 1323 1324 /* 1325 * get next header offset. m will be retained. 1326 */ 1327 int 1328 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1329 { 1330 struct ip6_hdr ip6; 1331 struct ip6_ext ip6e; 1332 struct ip6_frag fh; 1333 1334 /* just in case */ 1335 if (m == NULL) 1336 panic("%s: m == NULL", __func__); 1337 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1338 return -1; 1339 1340 switch (proto) { 1341 case IPPROTO_IPV6: 1342 if (m->m_pkthdr.len < off + sizeof(ip6)) 1343 return -1; 1344 m_copydata(m, off, sizeof(ip6), &ip6); 1345 if (nxtp) 1346 *nxtp = ip6.ip6_nxt; 1347 off += sizeof(ip6); 1348 return off; 1349 1350 case IPPROTO_FRAGMENT: 1351 /* 1352 * terminate parsing if it is not the first fragment, 1353 * it does not make sense to parse through it. 1354 */ 1355 if (m->m_pkthdr.len < off + sizeof(fh)) 1356 return -1; 1357 m_copydata(m, off, sizeof(fh), &fh); 1358 if ((fh.ip6f_offlg & IP6F_OFF_MASK) != 0) 1359 return -1; 1360 if (nxtp) 1361 *nxtp = fh.ip6f_nxt; 1362 off += sizeof(struct ip6_frag); 1363 return off; 1364 1365 case IPPROTO_AH: 1366 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1367 return -1; 1368 m_copydata(m, off, sizeof(ip6e), &ip6e); 1369 if (nxtp) 1370 *nxtp = ip6e.ip6e_nxt; 1371 off += (ip6e.ip6e_len + 2) << 2; 1372 if (m->m_pkthdr.len < off) 1373 return -1; 1374 return off; 1375 1376 case IPPROTO_HOPOPTS: 1377 case IPPROTO_ROUTING: 1378 case IPPROTO_DSTOPTS: 1379 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1380 return -1; 1381 m_copydata(m, off, sizeof(ip6e), &ip6e); 1382 if (nxtp) 1383 *nxtp = ip6e.ip6e_nxt; 1384 off += (ip6e.ip6e_len + 1) << 3; 1385 if (m->m_pkthdr.len < off) 1386 return -1; 1387 return off; 1388 1389 case IPPROTO_NONE: 1390 case IPPROTO_ESP: 1391 case IPPROTO_IPCOMP: 1392 /* give up */ 1393 return -1; 1394 1395 default: 1396 return -1; 1397 } 1398 1399 return -1; 1400 } 1401 1402 /* 1403 * get offset for the last header in the chain. m will be kept untainted. 1404 */ 1405 int 1406 ip6_lasthdr(struct mbuf *m, int off, int proto, 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 /* 1430 * System control for IP6 1431 */ 1432 1433 const u_char inet6ctlerrmap[PRC_NCMDS] = { 1434 0, 0, 0, 0, 1435 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1436 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1437 EMSGSIZE, EHOSTUNREACH, 0, 0, 1438 0, 0, 0, 0, 1439 ENOPROTOOPT 1440 }; 1441 1442 #ifdef MROUTING 1443 extern int ip6_mrtproto; 1444 #endif 1445 1446 const struct sysctl_bounded_args ipv6ctl_vars_unlocked[] = { 1447 { IPV6CTL_FORWARDING, &ip6_forwarding, 0, 2 }, 1448 { IPV6CTL_SENDREDIRECTS, &ip6_sendredirects, 0, 1 }, 1449 }; 1450 1451 const struct sysctl_bounded_args ipv6ctl_vars[] = { 1452 { IPV6CTL_DAD_PENDING, &ip6_dad_pending, SYSCTL_INT_READONLY }, 1453 #ifdef MROUTING 1454 { IPV6CTL_MRTPROTO, &ip6_mrtproto, SYSCTL_INT_READONLY }, 1455 #endif 1456 { IPV6CTL_DEFHLIM, &ip6_defhlim, 0, 255 }, 1457 { IPV6CTL_MAXFRAGPACKETS, &ip6_maxfragpackets, 0, 1000 }, 1458 { IPV6CTL_LOG_INTERVAL, &ip6_log_interval, 0, INT_MAX }, 1459 { IPV6CTL_HDRNESTLIMIT, &ip6_hdrnestlimit, 0, 100 }, 1460 { IPV6CTL_DAD_COUNT, &ip6_dad_count, 0, 10 }, 1461 { IPV6CTL_AUTO_FLOWLABEL, &ip6_auto_flowlabel, 0, 1 }, 1462 { IPV6CTL_DEFMCASTHLIM, &ip6_defmcasthlim, 0, 255 }, 1463 { IPV6CTL_USE_DEPRECATED, &ip6_use_deprecated, 0, 1 }, 1464 { IPV6CTL_MAXFRAGS, &ip6_maxfrags, 0, 1000 }, 1465 { IPV6CTL_MFORWARDING, &ip6_mforwarding, 0, 1 }, 1466 { IPV6CTL_MCAST_PMTU, &ip6_mcast_pmtu, 0, 1 }, 1467 { IPV6CTL_NEIGHBORGCTHRESH, &ip6_neighborgcthresh, -1, 5 * 2048 }, 1468 { IPV6CTL_MAXDYNROUTES, &ip6_maxdynroutes, -1, 5 * 4096 }, 1469 }; 1470 1471 int 1472 ip6_sysctl_ip6stat(void *oldp, size_t *oldlenp, void *newp) 1473 { 1474 struct ip6stat *ip6stat; 1475 int ret; 1476 1477 CTASSERT(sizeof(*ip6stat) == (ip6s_ncounters * sizeof(uint64_t))); 1478 1479 ip6stat = malloc(sizeof(*ip6stat), M_TEMP, M_WAITOK); 1480 counters_read(ip6counters, (uint64_t *)ip6stat, ip6s_ncounters, NULL); 1481 ret = sysctl_rdstruct(oldp, oldlenp, newp, 1482 ip6stat, sizeof(*ip6stat)); 1483 free(ip6stat, M_TEMP, sizeof(*ip6stat)); 1484 1485 return (ret); 1486 } 1487 1488 int 1489 ip6_sysctl_soiikey(void *oldp, size_t *oldlenp, void *newp, size_t newlen) 1490 { 1491 uint8_t oldkey[IP6_SOIIKEY_LEN]; 1492 int error; 1493 1494 error = suser(curproc); 1495 if (error != 0) 1496 return (error); 1497 1498 memcpy(oldkey, ip6_soiikey, sizeof(oldkey)); 1499 1500 error = sysctl_struct(oldp, oldlenp, newp, newlen, ip6_soiikey, 1501 sizeof(ip6_soiikey)); 1502 1503 return (error); 1504 } 1505 1506 int 1507 ip6_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, 1508 void *newp, size_t newlen) 1509 { 1510 #ifdef MROUTING 1511 extern struct mrt6stat mrt6stat; 1512 #endif 1513 int oldval, error; 1514 1515 /* Almost all sysctl names at this level are terminal. */ 1516 if (namelen != 1 && name[0] != IPV6CTL_IFQUEUE) 1517 return (ENOTDIR); 1518 1519 switch (name[0]) { 1520 case IPV6CTL_STATS: 1521 return (ip6_sysctl_ip6stat(oldp, oldlenp, newp)); 1522 #ifdef MROUTING 1523 case IPV6CTL_MRTSTATS: 1524 if (newp != NULL) 1525 return (EPERM); 1526 NET_LOCK(); 1527 error = sysctl_struct(oldp, oldlenp, newp, newlen, 1528 &mrt6stat, sizeof(mrt6stat)); 1529 NET_UNLOCK(); 1530 return (error); 1531 case IPV6CTL_MRTMIF: 1532 if (newp) 1533 return (EPERM); 1534 NET_LOCK(); 1535 error = mrt6_sysctl_mif(oldp, oldlenp); 1536 NET_UNLOCK(); 1537 return (error); 1538 case IPV6CTL_MRTMFC: 1539 if (newp) 1540 return (EPERM); 1541 NET_LOCK(); 1542 error = mrt6_sysctl_mfc(oldp, oldlenp); 1543 NET_UNLOCK(); 1544 return (error); 1545 #else 1546 case IPV6CTL_MRTSTATS: 1547 case IPV6CTL_MRTPROTO: 1548 case IPV6CTL_MRTMIF: 1549 case IPV6CTL_MRTMFC: 1550 return (EOPNOTSUPP); 1551 #endif 1552 case IPV6CTL_MTUDISCTIMEOUT: 1553 NET_LOCK(); 1554 error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, 1555 &ip6_mtudisc_timeout, 0, INT_MAX); 1556 rt_timer_queue_change(&icmp6_mtudisc_timeout_q, 1557 ip6_mtudisc_timeout); 1558 NET_UNLOCK(); 1559 return (error); 1560 case IPV6CTL_IFQUEUE: 1561 return (sysctl_niq(name + 1, namelen - 1, 1562 oldp, oldlenp, newp, newlen, &ip6intrq)); 1563 case IPV6CTL_SOIIKEY: 1564 return (ip6_sysctl_soiikey(oldp, oldlenp, newp, newlen)); 1565 case IPV6CTL_MULTIPATH: 1566 NET_LOCK(); 1567 oldval = ip6_multipath; 1568 error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, 1569 &ip6_multipath, 0, 1); 1570 if (oldval != ip6_multipath) 1571 atomic_inc_long(&rtgeneration); 1572 NET_UNLOCK(); 1573 return (error); 1574 case IPV6CTL_FORWARDING: 1575 case IPV6CTL_SENDREDIRECTS: 1576 return (sysctl_bounded_arr( 1577 ipv6ctl_vars_unlocked, nitems(ipv6ctl_vars_unlocked), 1578 name, namelen, oldp, oldlenp, newp, newlen)); 1579 default: 1580 NET_LOCK(); 1581 error = sysctl_bounded_arr(ipv6ctl_vars, nitems(ipv6ctl_vars), 1582 name, namelen, oldp, oldlenp, newp, newlen); 1583 NET_UNLOCK(); 1584 return (error); 1585 } 1586 /* NOTREACHED */ 1587 } 1588 1589 void 1590 ip6_send_dispatch(void *xmq) 1591 { 1592 struct mbuf_queue *mq = xmq; 1593 struct mbuf *m; 1594 struct mbuf_list ml; 1595 1596 mq_delist(mq, &ml); 1597 if (ml_empty(&ml)) 1598 return; 1599 1600 NET_LOCK_SHARED(); 1601 while ((m = ml_dequeue(&ml)) != NULL) { 1602 ip6_output(m, NULL, NULL, 0, NULL, NULL); 1603 } 1604 NET_UNLOCK_SHARED(); 1605 } 1606 1607 void 1608 ip6_send(struct mbuf *m) 1609 { 1610 mq_enqueue(&ip6send_mq, m); 1611 task_add(net_tq(0), &ip6send_task); 1612 } 1613