1 /* $OpenBSD: ip6_input.c,v 1.262 2024/05/08 13:01:30 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); 123 int ip6_check_rh0hdr(struct mbuf *, int *); 124 int ip6_hbhchcheck(struct mbuf **, 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) 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); 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 pfrdr = 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 pfrdr = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 416 #endif 417 418 /* 419 * Without embedded scope ID we cannot find link-local 420 * addresses in the routing table. 421 */ 422 if (ifp->if_flags & IFF_LOOPBACK) { 423 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) 424 ip6->ip6_src.s6_addr16[1] = src_scope; 425 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) 426 ip6->ip6_dst.s6_addr16[1] = dst_scope; 427 } else { 428 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) 429 ip6->ip6_src.s6_addr16[1] = htons(ifp->if_index); 430 if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) 431 ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); 432 } 433 434 /* 435 * Be more secure than RFC5095 and scan for type 0 routing headers. 436 * If pf has already scanned the header chain, do not do it twice. 437 */ 438 if (!(m->m_pkthdr.pf.flags & PF_TAG_PROCESSED) && 439 ip6_check_rh0hdr(m, offp)) { 440 ip6stat_inc(ip6s_badoptions); 441 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, *offp); 442 m = *mp = NULL; 443 goto bad; 444 } 445 446 #if NPF > 0 447 if (pf_ouraddr(m) == 1) { 448 nxt = ip6_ours(mp, offp, nxt, af); 449 goto out; 450 } 451 #endif 452 453 /* 454 * Multicast check 455 */ 456 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 457 /* 458 * Make sure M_MCAST is set. It should theoretically 459 * already be there, but let's play safe because upper 460 * layers check for this flag. 461 */ 462 m->m_flags |= M_MCAST; 463 464 /* 465 * See if we belong to the destination multicast group on the 466 * arrival interface. 467 */ 468 if (in6_hasmulti(&ip6->ip6_dst, ifp)) 469 ours = 1; 470 471 #ifdef MROUTING 472 if (ip6_mforwarding && ip6_mrouter[ifp->if_rdomain]) { 473 int error; 474 475 nxt = ip6_hbhchcheck(&m, offp, &ours); 476 if (nxt == IPPROTO_DONE) 477 goto out; 478 479 ip6 = mtod(m, struct ip6_hdr *); 480 481 /* 482 * If we are acting as a multicast router, all 483 * incoming multicast packets are passed to the 484 * kernel-level multicast forwarding function. 485 * The packet is returned (relatively) intact; if 486 * ip6_mforward() returns a non-zero value, the packet 487 * must be discarded, else it may be accepted below. 488 */ 489 KERNEL_LOCK(); 490 error = ip6_mforward(ip6, ifp, m); 491 KERNEL_UNLOCK(); 492 if (error) { 493 ip6stat_inc(ip6s_cantforward); 494 goto bad; 495 } 496 497 if (ours) { 498 if (af == AF_UNSPEC) 499 nxt = ip6_ours(mp, offp, nxt, af); 500 goto out; 501 } 502 goto bad; 503 } 504 #endif 505 if (!ours) { 506 ip6stat_inc(ip6s_notmember); 507 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 508 ip6stat_inc(ip6s_cantforward); 509 goto bad; 510 } 511 nxt = ip6_ours(mp, offp, nxt, af); 512 goto out; 513 } 514 515 516 /* 517 * Unicast check 518 */ 519 rt = route6_mpath(&ro, &ip6->ip6_dst, &ip6->ip6_src, 520 m->m_pkthdr.ph_rtableid); 521 522 /* 523 * Accept the packet if the route to the destination is marked 524 * as local. 525 */ 526 if (rt != NULL && ISSET(rt->rt_flags, RTF_LOCAL)) { 527 struct in6_ifaddr *ia6 = ifatoia6(rt->rt_ifa); 528 529 if (ip6_forwarding == 0 && rt->rt_ifidx != ifp->if_index && 530 !((ifp->if_flags & IFF_LOOPBACK) || 531 (ifp->if_type == IFT_ENC) || 532 (m->m_pkthdr.pf.flags & PF_TAG_TRANSLATE_LOCALHOST))) { 533 /* received on wrong interface */ 534 #if NCARP > 0 535 struct ifnet *out_if; 536 537 /* 538 * Virtual IPs on carp interfaces need to be checked 539 * also against the parent interface and other carp 540 * interfaces sharing the same parent. 541 */ 542 out_if = if_get(rt->rt_ifidx); 543 if (!(out_if && carp_strict_addr_chk(out_if, ifp))) { 544 ip6stat_inc(ip6s_wrongif); 545 if_put(out_if); 546 goto bad; 547 } 548 if_put(out_if); 549 #else 550 ip6stat_inc(ip6s_wrongif); 551 goto bad; 552 #endif 553 } 554 /* 555 * packets to a tentative, duplicated, or somehow invalid 556 * address must not be accepted. 557 */ 558 if ((ia6->ia6_flags & (IN6_IFF_TENTATIVE|IN6_IFF_DUPLICATED))) { 559 char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; 560 561 inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)); 562 inet_ntop(AF_INET6, &ip6->ip6_dst, dst, sizeof(dst)); 563 /* address is not ready, so discard the packet. */ 564 nd6log((LOG_INFO, 565 "%s: packet to an unready address %s->%s\n", 566 __func__, src, dst)); 567 568 goto bad; 569 } else { 570 nxt = ip6_ours(mp, offp, nxt, af); 571 goto out; 572 } 573 } 574 575 #if NCARP > 0 576 if (ip6->ip6_nxt == IPPROTO_ICMPV6 && 577 carp_lsdrop(ifp, m, AF_INET6, ip6->ip6_src.s6_addr32, 578 ip6->ip6_dst.s6_addr32, 1)) 579 goto bad; 580 #endif 581 /* 582 * Now there is no reason to process the packet if it's not our own 583 * and we're not a router. 584 */ 585 if (!ip6_forwarding) { 586 ip6stat_inc(ip6s_cantforward); 587 goto bad; 588 } 589 590 nxt = ip6_hbhchcheck(&m, offp, &ours); 591 if (nxt == IPPROTO_DONE) 592 goto out; 593 594 if (ours) { 595 if (af == AF_UNSPEC) 596 nxt = ip6_ours(mp, offp, nxt, af); 597 goto out; 598 } 599 600 #ifdef IPSEC 601 if (ipsec_in_use) { 602 int rv; 603 604 rv = ipsec_forward_check(m, *offp, AF_INET6); 605 if (rv != 0) { 606 ip6stat_inc(ip6s_cantforward); 607 goto bad; 608 } 609 /* 610 * Fall through, forward packet. Outbound IPsec policy 611 * checking will occur in ip6_forward(). 612 */ 613 } 614 #endif /* IPSEC */ 615 616 ip6_forward(m, &ro, pfrdr); 617 *mp = NULL; 618 rtfree(ro.ro_rt); 619 return IPPROTO_DONE; 620 bad: 621 nxt = IPPROTO_DONE; 622 m_freemp(mp); 623 out: 624 rtfree(ro.ro_rt); 625 return nxt; 626 } 627 628 /* On error free mbuf and return IPPROTO_DONE. */ 629 int 630 ip6_hbhchcheck(struct mbuf **mp, int *offp, int *oursp) 631 { 632 struct ip6_hdr *ip6; 633 u_int32_t plen, rtalert = ~0; 634 int nxt; 635 636 ip6 = mtod(*mp, struct ip6_hdr *); 637 638 /* 639 * Process Hop-by-Hop options header if it's contained. 640 * m may be modified in ip6_hopopts_input(). 641 * If a JumboPayload option is included, plen will also be modified. 642 */ 643 plen = (u_int32_t)ntohs(ip6->ip6_plen); 644 *offp = sizeof(struct ip6_hdr); 645 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 646 struct ip6_hbh *hbh; 647 648 if (ip6_hopopts_input(mp, offp, &plen, &rtalert)) 649 goto bad; /* m have already been freed */ 650 651 /* adjust pointer */ 652 ip6 = mtod(*mp, struct ip6_hdr *); 653 654 /* 655 * if the payload length field is 0 and the next header field 656 * indicates Hop-by-Hop Options header, then a Jumbo Payload 657 * option MUST be included. 658 */ 659 if (ip6->ip6_plen == 0 && plen == 0) { 660 /* 661 * Note that if a valid jumbo payload option is 662 * contained, ip6_hopopts_input() must set a valid 663 * (non-zero) payload length to the variable plen. 664 */ 665 ip6stat_inc(ip6s_badoptions); 666 icmp6_error(*mp, ICMP6_PARAM_PROB, 667 ICMP6_PARAMPROB_HEADER, 668 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 669 goto bad; 670 } 671 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, *mp, 672 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 673 if (hbh == NULL) { 674 ip6stat_inc(ip6s_tooshort); 675 goto bad; 676 } 677 nxt = hbh->ip6h_nxt; 678 679 /* 680 * accept the packet if a router alert option is included 681 * and we act as an IPv6 router. 682 */ 683 if (rtalert != ~0 && ip6_forwarding && oursp != NULL) 684 *oursp = 1; 685 } else 686 nxt = ip6->ip6_nxt; 687 688 /* 689 * Check that the amount of data in the buffers 690 * is as at least much as the IPv6 header would have us expect. 691 * Trim mbufs if longer than we expect. 692 * Drop packet if shorter than we expect. 693 */ 694 if ((*mp)->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 695 ip6stat_inc(ip6s_tooshort); 696 m_freemp(mp); 697 goto bad; 698 } 699 if ((*mp)->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 700 if ((*mp)->m_len == (*mp)->m_pkthdr.len) { 701 (*mp)->m_len = sizeof(struct ip6_hdr) + plen; 702 (*mp)->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 703 } else { 704 m_adj((*mp), sizeof(struct ip6_hdr) + plen - 705 (*mp)->m_pkthdr.len); 706 } 707 } 708 709 return nxt; 710 bad: 711 return IPPROTO_DONE; 712 } 713 714 /* scan packet for RH0 routing header. Mostly stolen from pf.c:pf_test() */ 715 int 716 ip6_check_rh0hdr(struct mbuf *m, int *offp) 717 { 718 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 719 struct ip6_rthdr rthdr; 720 struct ip6_ext opt6; 721 u_int8_t proto = ip6->ip6_nxt; 722 int done = 0, lim, off, rh_cnt = 0; 723 724 off = ((caddr_t)ip6 - m->m_data) + sizeof(struct ip6_hdr); 725 lim = min(m->m_pkthdr.len, ntohs(ip6->ip6_plen) + sizeof(*ip6)); 726 do { 727 switch (proto) { 728 case IPPROTO_ROUTING: 729 if (rh_cnt++) { 730 /* more than one rh header present */ 731 *offp = off; 732 return (1); 733 } 734 735 if (off + sizeof(rthdr) > lim) { 736 /* packet to short to make sense */ 737 *offp = off; 738 return (1); 739 } 740 741 m_copydata(m, off, sizeof(rthdr), &rthdr); 742 743 if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) { 744 *offp = off + 745 offsetof(struct ip6_rthdr, ip6r_type); 746 return (1); 747 } 748 749 off += (rthdr.ip6r_len + 1) * 8; 750 proto = rthdr.ip6r_nxt; 751 break; 752 case IPPROTO_AH: 753 case IPPROTO_HOPOPTS: 754 case IPPROTO_DSTOPTS: 755 /* get next header and header length */ 756 if (off + sizeof(opt6) > lim) { 757 /* 758 * Packet to short to make sense, we could 759 * reject the packet but as a router we 760 * should not do that so forward it. 761 */ 762 return (0); 763 } 764 765 m_copydata(m, off, sizeof(opt6), &opt6); 766 767 if (proto == IPPROTO_AH) 768 off += (opt6.ip6e_len + 2) * 4; 769 else 770 off += (opt6.ip6e_len + 1) * 8; 771 proto = opt6.ip6e_nxt; 772 break; 773 case IPPROTO_FRAGMENT: 774 default: 775 /* end of header stack */ 776 done = 1; 777 break; 778 } 779 } while (!done); 780 781 return (0); 782 } 783 784 /* 785 * Hop-by-Hop options header processing. If a valid jumbo payload option is 786 * included, the real payload length will be stored in plenp. 787 * On error free mbuf and return -1. 788 * 789 * rtalertp - XXX: should be stored in a more smart way 790 */ 791 int 792 ip6_hopopts_input(struct mbuf **mp, int *offp, u_int32_t *plenp, 793 u_int32_t *rtalertp) 794 { 795 int off = *offp, hbhlen; 796 struct ip6_hbh *hbh; 797 798 /* validation of the length of the header */ 799 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, *mp, 800 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 801 if (hbh == NULL) { 802 ip6stat_inc(ip6s_tooshort); 803 return -1; 804 } 805 hbhlen = (hbh->ip6h_len + 1) << 3; 806 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, *mp, sizeof(struct ip6_hdr), 807 hbhlen); 808 if (hbh == NULL) { 809 ip6stat_inc(ip6s_tooshort); 810 return -1; 811 } 812 off += hbhlen; 813 hbhlen -= sizeof(struct ip6_hbh); 814 815 if (ip6_process_hopopts(mp, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 816 hbhlen, rtalertp, plenp) < 0) 817 return (-1); 818 819 *offp = off; 820 return (0); 821 } 822 823 /* 824 * Search header for all Hop-by-hop options and process each option. 825 * This function is separate from ip6_hopopts_input() in order to 826 * handle a case where the sending node itself process its hop-by-hop 827 * options header. In such a case, the function is called from ip6_output(). 828 * On error free mbuf and return -1. 829 * 830 * The function assumes that hbh header is located right after the IPv6 header 831 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 832 * opthead + hbhlen is located in continuous memory region. 833 */ 834 int 835 ip6_process_hopopts(struct mbuf **mp, u_int8_t *opthead, int hbhlen, 836 u_int32_t *rtalertp, u_int32_t *plenp) 837 { 838 struct ip6_hdr *ip6; 839 int optlen = 0; 840 u_int8_t *opt = opthead; 841 u_int16_t rtalert_val; 842 u_int32_t jumboplen; 843 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 844 845 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 846 switch (*opt) { 847 case IP6OPT_PAD1: 848 optlen = 1; 849 break; 850 case IP6OPT_PADN: 851 if (hbhlen < IP6OPT_MINLEN) { 852 ip6stat_inc(ip6s_toosmall); 853 goto bad; 854 } 855 optlen = *(opt + 1) + 2; 856 break; 857 case IP6OPT_ROUTER_ALERT: 858 /* XXX may need check for alignment */ 859 if (hbhlen < IP6OPT_RTALERT_LEN) { 860 ip6stat_inc(ip6s_toosmall); 861 goto bad; 862 } 863 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 864 /* XXX stat */ 865 icmp6_error(*mp, ICMP6_PARAM_PROB, 866 ICMP6_PARAMPROB_HEADER, 867 erroff + opt + 1 - opthead); 868 return (-1); 869 } 870 optlen = IP6OPT_RTALERT_LEN; 871 memcpy((caddr_t)&rtalert_val, (caddr_t)(opt + 2), 2); 872 *rtalertp = ntohs(rtalert_val); 873 break; 874 case IP6OPT_JUMBO: 875 /* XXX may need check for alignment */ 876 if (hbhlen < IP6OPT_JUMBO_LEN) { 877 ip6stat_inc(ip6s_toosmall); 878 goto bad; 879 } 880 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 881 /* XXX stat */ 882 icmp6_error(*mp, ICMP6_PARAM_PROB, 883 ICMP6_PARAMPROB_HEADER, 884 erroff + opt + 1 - opthead); 885 return (-1); 886 } 887 optlen = IP6OPT_JUMBO_LEN; 888 889 /* 890 * IPv6 packets that have non 0 payload length 891 * must not contain a jumbo payload option. 892 */ 893 ip6 = mtod(*mp, struct ip6_hdr *); 894 if (ip6->ip6_plen) { 895 ip6stat_inc(ip6s_badoptions); 896 icmp6_error(*mp, ICMP6_PARAM_PROB, 897 ICMP6_PARAMPROB_HEADER, 898 erroff + opt - opthead); 899 return (-1); 900 } 901 902 /* 903 * We may see jumbolen in unaligned location, so 904 * we'd need to perform memcpy(). 905 */ 906 memcpy(&jumboplen, opt + 2, sizeof(jumboplen)); 907 jumboplen = (u_int32_t)htonl(jumboplen); 908 909 #if 1 910 /* 911 * if there are multiple jumbo payload options, 912 * *plenp will be non-zero and the packet will be 913 * rejected. 914 * the behavior may need some debate in ipngwg - 915 * multiple options does not make sense, however, 916 * there's no explicit mention in specification. 917 */ 918 if (*plenp != 0) { 919 ip6stat_inc(ip6s_badoptions); 920 icmp6_error(*mp, ICMP6_PARAM_PROB, 921 ICMP6_PARAMPROB_HEADER, 922 erroff + opt + 2 - opthead); 923 return (-1); 924 } 925 #endif 926 927 /* 928 * jumbo payload length must be larger than 65535. 929 */ 930 if (jumboplen <= IPV6_MAXPACKET) { 931 ip6stat_inc(ip6s_badoptions); 932 icmp6_error(*mp, ICMP6_PARAM_PROB, 933 ICMP6_PARAMPROB_HEADER, 934 erroff + opt + 2 - opthead); 935 return (-1); 936 } 937 *plenp = jumboplen; 938 939 break; 940 default: /* unknown option */ 941 if (hbhlen < IP6OPT_MINLEN) { 942 ip6stat_inc(ip6s_toosmall); 943 goto bad; 944 } 945 optlen = ip6_unknown_opt(mp, opt, 946 erroff + opt - opthead); 947 if (optlen == -1) 948 return (-1); 949 optlen += 2; 950 break; 951 } 952 } 953 954 return (0); 955 956 bad: 957 m_freemp(mp); 958 return (-1); 959 } 960 961 /* 962 * Unknown option processing. 963 * The third argument `off' is the offset from the IPv6 header to the option, 964 * which allows returning an ICMPv6 error even if the IPv6 header and the 965 * option header are not continuous. 966 * On error free mbuf and return -1. 967 */ 968 int 969 ip6_unknown_opt(struct mbuf **mp, u_int8_t *optp, int off) 970 { 971 struct ip6_hdr *ip6; 972 973 switch (IP6OPT_TYPE(*optp)) { 974 case IP6OPT_TYPE_SKIP: /* ignore the option */ 975 return ((int)*(optp + 1)); 976 case IP6OPT_TYPE_DISCARD: /* silently discard */ 977 m_freemp(mp); 978 return (-1); 979 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 980 ip6stat_inc(ip6s_badoptions); 981 icmp6_error(*mp, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 982 return (-1); 983 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 984 ip6stat_inc(ip6s_badoptions); 985 ip6 = mtod(*mp, struct ip6_hdr *); 986 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 987 ((*mp)->m_flags & (M_BCAST|M_MCAST))) 988 m_freemp(mp); 989 else 990 icmp6_error(*mp, ICMP6_PARAM_PROB, 991 ICMP6_PARAMPROB_OPTION, off); 992 return (-1); 993 } 994 995 m_freemp(mp); /* XXX: NOTREACHED */ 996 return (-1); 997 } 998 999 /* 1000 * Create the "control" list for this pcb. 1001 * 1002 * The routine will be called from upper layer handlers like udp_input(). 1003 * Thus the routine assumes that the caller (udp_input) have already 1004 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1005 * very first mbuf on the mbuf chain. 1006 * We may want to add some infinite loop prevention or sanity checks for safety. 1007 * (This applies only when you are using KAME mbuf chain restriction, i.e. 1008 * you are using IP6_EXTHDR_CHECK() not m_pulldown()) 1009 */ 1010 void 1011 ip6_savecontrol(struct inpcb *inp, struct mbuf *m, struct mbuf **mp) 1012 { 1013 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1014 1015 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1016 struct timeval tv; 1017 1018 m_microtime(m, &tv); 1019 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1020 SCM_TIMESTAMP, SOL_SOCKET); 1021 if (*mp) 1022 mp = &(*mp)->m_next; 1023 } 1024 1025 /* RFC 2292 sec. 5 */ 1026 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1027 struct in6_pktinfo pi6; 1028 memcpy(&pi6.ipi6_addr, &ip6->ip6_dst, sizeof(struct in6_addr)); 1029 if (IN6_IS_SCOPE_EMBED(&pi6.ipi6_addr)) 1030 pi6.ipi6_addr.s6_addr16[1] = 0; 1031 pi6.ipi6_ifindex = m ? m->m_pkthdr.ph_ifidx : 0; 1032 *mp = sbcreatecontrol((caddr_t) &pi6, 1033 sizeof(struct in6_pktinfo), 1034 IPV6_PKTINFO, IPPROTO_IPV6); 1035 if (*mp) 1036 mp = &(*mp)->m_next; 1037 } 1038 1039 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1040 int hlim = ip6->ip6_hlim & 0xff; 1041 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1042 IPV6_HOPLIMIT, IPPROTO_IPV6); 1043 if (*mp) 1044 mp = &(*mp)->m_next; 1045 } 1046 1047 if ((inp->inp_flags & IN6P_TCLASS) != 0) { 1048 u_int32_t flowinfo; 1049 int tclass; 1050 1051 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1052 flowinfo >>= 20; 1053 1054 tclass = flowinfo & 0xff; 1055 *mp = sbcreatecontrol((caddr_t)&tclass, sizeof(tclass), 1056 IPV6_TCLASS, IPPROTO_IPV6); 1057 if (*mp) 1058 mp = &(*mp)->m_next; 1059 } 1060 1061 /* 1062 * IPV6_HOPOPTS socket option. Recall that we required super-user 1063 * privilege for the option (see ip6_ctloutput), but it might be too 1064 * strict, since there might be some hop-by-hop options which can be 1065 * returned to normal user. 1066 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1067 */ 1068 if ((inp->inp_flags & IN6P_HOPOPTS) != 0) { 1069 /* 1070 * Check if a hop-by-hop options header is contained in the 1071 * received packet, and if so, store the options as ancillary 1072 * data. Note that a hop-by-hop options header must be 1073 * just after the IPv6 header, which is assured through the 1074 * IPv6 input processing. 1075 */ 1076 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1077 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1078 struct ip6_hbh *hbh; 1079 int hbhlen = 0; 1080 struct mbuf *ext; 1081 1082 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1083 ip6->ip6_nxt); 1084 if (ext == NULL) { 1085 ip6stat_inc(ip6s_tooshort); 1086 return; 1087 } 1088 hbh = mtod(ext, struct ip6_hbh *); 1089 hbhlen = (hbh->ip6h_len + 1) << 3; 1090 if (hbhlen != ext->m_len) { 1091 m_freem(ext); 1092 ip6stat_inc(ip6s_tooshort); 1093 return; 1094 } 1095 1096 /* 1097 * XXX: We copy the whole header even if a 1098 * jumbo payload option is included, the option which 1099 * is to be removed before returning according to 1100 * RFC2292. 1101 * Note: this constraint is removed in RFC3542. 1102 */ 1103 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1104 IPV6_HOPOPTS, 1105 IPPROTO_IPV6); 1106 if (*mp) 1107 mp = &(*mp)->m_next; 1108 m_freem(ext); 1109 } 1110 } 1111 1112 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1113 if ((inp->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1114 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1115 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1116 1117 /* 1118 * Search for destination options headers or routing 1119 * header(s) through the header chain, and stores each 1120 * header as ancillary data. 1121 * Note that the order of the headers remains in 1122 * the chain of ancillary data. 1123 */ 1124 while (1) { /* is explicit loop prevention necessary? */ 1125 struct ip6_ext *ip6e = NULL; 1126 int elen; 1127 struct mbuf *ext = NULL; 1128 1129 /* 1130 * if it is not an extension header, don't try to 1131 * pull it from the chain. 1132 */ 1133 switch (nxt) { 1134 case IPPROTO_DSTOPTS: 1135 case IPPROTO_ROUTING: 1136 case IPPROTO_HOPOPTS: 1137 case IPPROTO_AH: /* is it possible? */ 1138 break; 1139 default: 1140 goto loopend; 1141 } 1142 1143 ext = ip6_pullexthdr(m, off, nxt); 1144 if (ext == NULL) { 1145 ip6stat_inc(ip6s_tooshort); 1146 return; 1147 } 1148 ip6e = mtod(ext, struct ip6_ext *); 1149 if (nxt == IPPROTO_AH) 1150 elen = (ip6e->ip6e_len + 2) << 2; 1151 else 1152 elen = (ip6e->ip6e_len + 1) << 3; 1153 if (elen != ext->m_len) { 1154 m_freem(ext); 1155 ip6stat_inc(ip6s_tooshort); 1156 return; 1157 } 1158 1159 switch (nxt) { 1160 case IPPROTO_DSTOPTS: 1161 if (!(inp->inp_flags & IN6P_DSTOPTS)) 1162 break; 1163 1164 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1165 IPV6_DSTOPTS, 1166 IPPROTO_IPV6); 1167 if (*mp) 1168 mp = &(*mp)->m_next; 1169 break; 1170 1171 case IPPROTO_ROUTING: 1172 if (!(inp->inp_flags & IN6P_RTHDR)) 1173 break; 1174 1175 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1176 IPV6_RTHDR, 1177 IPPROTO_IPV6); 1178 if (*mp) 1179 mp = &(*mp)->m_next; 1180 break; 1181 1182 case IPPROTO_HOPOPTS: 1183 case IPPROTO_AH: /* is it possible? */ 1184 break; 1185 1186 default: 1187 /* 1188 * other cases have been filtered in the above. 1189 * none will visit this case. here we supply 1190 * the code just in case (nxt overwritten or 1191 * other cases). 1192 */ 1193 m_freem(ext); 1194 goto loopend; 1195 1196 } 1197 1198 /* proceed with the next header. */ 1199 off += elen; 1200 nxt = ip6e->ip6e_nxt; 1201 ip6e = NULL; 1202 m_freem(ext); 1203 ext = NULL; 1204 } 1205 loopend: 1206 ; 1207 } 1208 } 1209 1210 /* 1211 * pull single extension header from mbuf chain. returns single mbuf that 1212 * contains the result, or NULL on error. 1213 */ 1214 struct mbuf * 1215 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1216 { 1217 struct ip6_ext ip6e; 1218 size_t elen; 1219 struct mbuf *n; 1220 1221 #ifdef DIAGNOSTIC 1222 switch (nxt) { 1223 case IPPROTO_DSTOPTS: 1224 case IPPROTO_ROUTING: 1225 case IPPROTO_HOPOPTS: 1226 case IPPROTO_AH: /* is it possible? */ 1227 break; 1228 default: 1229 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1230 } 1231 #endif 1232 1233 if (off + sizeof(ip6e) > m->m_pkthdr.len) 1234 return NULL; 1235 1236 m_copydata(m, off, sizeof(ip6e), &ip6e); 1237 if (nxt == IPPROTO_AH) 1238 elen = (ip6e.ip6e_len + 2) << 2; 1239 else 1240 elen = (ip6e.ip6e_len + 1) << 3; 1241 1242 if (off + elen > m->m_pkthdr.len) 1243 return NULL; 1244 1245 MGET(n, M_DONTWAIT, MT_DATA); 1246 if (n && elen >= MLEN) { 1247 MCLGET(n, M_DONTWAIT); 1248 if ((n->m_flags & M_EXT) == 0) { 1249 m_free(n); 1250 n = NULL; 1251 } 1252 } 1253 if (n == NULL) { 1254 ip6stat_inc(ip6s_idropped); 1255 return NULL; 1256 } 1257 1258 n->m_len = 0; 1259 if (elen >= m_trailingspace(n)) { 1260 m_free(n); 1261 return NULL; 1262 } 1263 1264 m_copydata(m, off, elen, mtod(n, caddr_t)); 1265 n->m_len = elen; 1266 return n; 1267 } 1268 1269 /* 1270 * Get offset to the previous header followed by the header 1271 * currently processed. 1272 */ 1273 int 1274 ip6_get_prevhdr(struct mbuf *m, int off) 1275 { 1276 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1277 1278 if (off == sizeof(struct ip6_hdr)) { 1279 return offsetof(struct ip6_hdr, ip6_nxt); 1280 } else if (off < sizeof(struct ip6_hdr)) { 1281 panic("%s: off < sizeof(struct ip6_hdr)", __func__); 1282 } else { 1283 int len, nlen, nxt; 1284 struct ip6_ext ip6e; 1285 1286 nxt = ip6->ip6_nxt; 1287 len = sizeof(struct ip6_hdr); 1288 nlen = 0; 1289 while (len < off) { 1290 m_copydata(m, len, sizeof(ip6e), &ip6e); 1291 1292 switch (nxt) { 1293 case IPPROTO_FRAGMENT: 1294 nlen = sizeof(struct ip6_frag); 1295 break; 1296 case IPPROTO_AH: 1297 nlen = (ip6e.ip6e_len + 2) << 2; 1298 break; 1299 default: 1300 nlen = (ip6e.ip6e_len + 1) << 3; 1301 break; 1302 } 1303 len += nlen; 1304 nxt = ip6e.ip6e_nxt; 1305 } 1306 1307 return (len - nlen); 1308 } 1309 } 1310 1311 /* 1312 * get next header offset. m will be retained. 1313 */ 1314 int 1315 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1316 { 1317 struct ip6_hdr ip6; 1318 struct ip6_ext ip6e; 1319 struct ip6_frag fh; 1320 1321 /* just in case */ 1322 if (m == NULL) 1323 panic("%s: m == NULL", __func__); 1324 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1325 return -1; 1326 1327 switch (proto) { 1328 case IPPROTO_IPV6: 1329 if (m->m_pkthdr.len < off + sizeof(ip6)) 1330 return -1; 1331 m_copydata(m, off, sizeof(ip6), &ip6); 1332 if (nxtp) 1333 *nxtp = ip6.ip6_nxt; 1334 off += sizeof(ip6); 1335 return off; 1336 1337 case IPPROTO_FRAGMENT: 1338 /* 1339 * terminate parsing if it is not the first fragment, 1340 * it does not make sense to parse through it. 1341 */ 1342 if (m->m_pkthdr.len < off + sizeof(fh)) 1343 return -1; 1344 m_copydata(m, off, sizeof(fh), &fh); 1345 if ((fh.ip6f_offlg & IP6F_OFF_MASK) != 0) 1346 return -1; 1347 if (nxtp) 1348 *nxtp = fh.ip6f_nxt; 1349 off += sizeof(struct ip6_frag); 1350 return off; 1351 1352 case IPPROTO_AH: 1353 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1354 return -1; 1355 m_copydata(m, off, sizeof(ip6e), &ip6e); 1356 if (nxtp) 1357 *nxtp = ip6e.ip6e_nxt; 1358 off += (ip6e.ip6e_len + 2) << 2; 1359 if (m->m_pkthdr.len < off) 1360 return -1; 1361 return off; 1362 1363 case IPPROTO_HOPOPTS: 1364 case IPPROTO_ROUTING: 1365 case IPPROTO_DSTOPTS: 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 + 1) << 3; 1372 if (m->m_pkthdr.len < off) 1373 return -1; 1374 return off; 1375 1376 case IPPROTO_NONE: 1377 case IPPROTO_ESP: 1378 case IPPROTO_IPCOMP: 1379 /* give up */ 1380 return -1; 1381 1382 default: 1383 return -1; 1384 } 1385 1386 return -1; 1387 } 1388 1389 /* 1390 * get offset for the last header in the chain. m will be kept untainted. 1391 */ 1392 int 1393 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1394 { 1395 int newoff; 1396 int nxt; 1397 1398 if (!nxtp) { 1399 nxt = -1; 1400 nxtp = &nxt; 1401 } 1402 while (1) { 1403 newoff = ip6_nexthdr(m, off, proto, nxtp); 1404 if (newoff < 0) 1405 return off; 1406 else if (newoff < off) 1407 return -1; /* invalid */ 1408 else if (newoff == off) 1409 return newoff; 1410 1411 off = newoff; 1412 proto = *nxtp; 1413 } 1414 } 1415 1416 /* 1417 * System control for IP6 1418 */ 1419 1420 const u_char inet6ctlerrmap[PRC_NCMDS] = { 1421 0, 0, 0, 0, 1422 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1423 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1424 EMSGSIZE, EHOSTUNREACH, 0, 0, 1425 0, 0, 0, 0, 1426 ENOPROTOOPT 1427 }; 1428 1429 #ifdef MROUTING 1430 extern int ip6_mrtproto; 1431 #endif 1432 1433 const struct sysctl_bounded_args ipv6ctl_vars[] = { 1434 { IPV6CTL_DAD_PENDING, &ip6_dad_pending, SYSCTL_INT_READONLY }, 1435 #ifdef MROUTING 1436 { IPV6CTL_MRTPROTO, &ip6_mrtproto, SYSCTL_INT_READONLY }, 1437 #endif 1438 { IPV6CTL_FORWARDING, &ip6_forwarding, 0, 1 }, 1439 { IPV6CTL_SENDREDIRECTS, &ip6_sendredirects, 0, 1 }, 1440 { IPV6CTL_DEFHLIM, &ip6_defhlim, 0, 255 }, 1441 { IPV6CTL_MAXFRAGPACKETS, &ip6_maxfragpackets, 0, 1000 }, 1442 { IPV6CTL_LOG_INTERVAL, &ip6_log_interval, 0, INT_MAX }, 1443 { IPV6CTL_HDRNESTLIMIT, &ip6_hdrnestlimit, 0, 100 }, 1444 { IPV6CTL_DAD_COUNT, &ip6_dad_count, 0, 10 }, 1445 { IPV6CTL_AUTO_FLOWLABEL, &ip6_auto_flowlabel, 0, 1 }, 1446 { IPV6CTL_DEFMCASTHLIM, &ip6_defmcasthlim, 0, 255 }, 1447 { IPV6CTL_USE_DEPRECATED, &ip6_use_deprecated, 0, 1 }, 1448 { IPV6CTL_MAXFRAGS, &ip6_maxfrags, 0, 1000 }, 1449 { IPV6CTL_MFORWARDING, &ip6_mforwarding, 0, 1 }, 1450 { IPV6CTL_MCAST_PMTU, &ip6_mcast_pmtu, 0, 1 }, 1451 { IPV6CTL_NEIGHBORGCTHRESH, &ip6_neighborgcthresh, -1, 5 * 2048 }, 1452 { IPV6CTL_MAXDYNROUTES, &ip6_maxdynroutes, -1, 5 * 4096 }, 1453 }; 1454 1455 int 1456 ip6_sysctl_ip6stat(void *oldp, size_t *oldlenp, void *newp) 1457 { 1458 struct ip6stat *ip6stat; 1459 int ret; 1460 1461 CTASSERT(sizeof(*ip6stat) == (ip6s_ncounters * sizeof(uint64_t))); 1462 1463 ip6stat = malloc(sizeof(*ip6stat), M_TEMP, M_WAITOK); 1464 counters_read(ip6counters, (uint64_t *)ip6stat, ip6s_ncounters, NULL); 1465 ret = sysctl_rdstruct(oldp, oldlenp, newp, 1466 ip6stat, sizeof(*ip6stat)); 1467 free(ip6stat, M_TEMP, sizeof(*ip6stat)); 1468 1469 return (ret); 1470 } 1471 1472 int 1473 ip6_sysctl_soiikey(void *oldp, size_t *oldlenp, void *newp, size_t newlen) 1474 { 1475 uint8_t oldkey[IP6_SOIIKEY_LEN]; 1476 int error; 1477 1478 error = suser(curproc); 1479 if (error != 0) 1480 return (error); 1481 1482 memcpy(oldkey, ip6_soiikey, sizeof(oldkey)); 1483 1484 error = sysctl_struct(oldp, oldlenp, newp, newlen, ip6_soiikey, 1485 sizeof(ip6_soiikey)); 1486 1487 return (error); 1488 } 1489 1490 int 1491 ip6_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, 1492 void *newp, size_t newlen) 1493 { 1494 #ifdef MROUTING 1495 extern struct mrt6stat mrt6stat; 1496 #endif 1497 int oldval, error; 1498 1499 /* Almost all sysctl names at this level are terminal. */ 1500 if (namelen != 1 && name[0] != IPV6CTL_IFQUEUE) 1501 return (ENOTDIR); 1502 1503 switch (name[0]) { 1504 case IPV6CTL_STATS: 1505 return (ip6_sysctl_ip6stat(oldp, oldlenp, newp)); 1506 #ifdef MROUTING 1507 case IPV6CTL_MRTSTATS: 1508 if (newp != NULL) 1509 return (EPERM); 1510 NET_LOCK(); 1511 error = sysctl_struct(oldp, oldlenp, newp, newlen, 1512 &mrt6stat, sizeof(mrt6stat)); 1513 NET_UNLOCK(); 1514 return (error); 1515 case IPV6CTL_MRTMIF: 1516 if (newp) 1517 return (EPERM); 1518 NET_LOCK(); 1519 error = mrt6_sysctl_mif(oldp, oldlenp); 1520 NET_UNLOCK(); 1521 return (error); 1522 case IPV6CTL_MRTMFC: 1523 if (newp) 1524 return (EPERM); 1525 NET_LOCK(); 1526 error = mrt6_sysctl_mfc(oldp, oldlenp); 1527 NET_UNLOCK(); 1528 return (error); 1529 #else 1530 case IPV6CTL_MRTSTATS: 1531 case IPV6CTL_MRTPROTO: 1532 case IPV6CTL_MRTMIF: 1533 case IPV6CTL_MRTMFC: 1534 return (EOPNOTSUPP); 1535 #endif 1536 case IPV6CTL_MTUDISCTIMEOUT: 1537 NET_LOCK(); 1538 error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, 1539 &ip6_mtudisc_timeout, 0, INT_MAX); 1540 rt_timer_queue_change(&icmp6_mtudisc_timeout_q, 1541 ip6_mtudisc_timeout); 1542 NET_UNLOCK(); 1543 return (error); 1544 case IPV6CTL_IFQUEUE: 1545 return (sysctl_niq(name + 1, namelen - 1, 1546 oldp, oldlenp, newp, newlen, &ip6intrq)); 1547 case IPV6CTL_SOIIKEY: 1548 return (ip6_sysctl_soiikey(oldp, oldlenp, newp, newlen)); 1549 case IPV6CTL_MULTIPATH: 1550 NET_LOCK(); 1551 oldval = ip6_multipath; 1552 error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, 1553 &ip6_multipath, 0, 1); 1554 if (oldval != ip6_multipath) 1555 atomic_inc_long(&rtgeneration); 1556 NET_UNLOCK(); 1557 return (error); 1558 default: 1559 NET_LOCK(); 1560 error = sysctl_bounded_arr(ipv6ctl_vars, nitems(ipv6ctl_vars), 1561 name, namelen, oldp, oldlenp, newp, newlen); 1562 NET_UNLOCK(); 1563 return (error); 1564 } 1565 /* NOTREACHED */ 1566 } 1567 1568 void 1569 ip6_send_dispatch(void *xmq) 1570 { 1571 struct mbuf_queue *mq = xmq; 1572 struct mbuf *m; 1573 struct mbuf_list ml; 1574 1575 mq_delist(mq, &ml); 1576 if (ml_empty(&ml)) 1577 return; 1578 1579 NET_LOCK_SHARED(); 1580 while ((m = ml_dequeue(&ml)) != NULL) { 1581 ip6_output(m, NULL, NULL, 0, NULL, NULL); 1582 } 1583 NET_UNLOCK_SHARED(); 1584 } 1585 1586 void 1587 ip6_send(struct mbuf *m) 1588 { 1589 mq_enqueue(&ip6send_mq, m); 1590 task_add(net_tq(0), &ip6send_task); 1591 } 1592