ip6_forward.c revision 185088
1/*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: ip6_forward.c,v 1.69 2001/05/17 03:48:30 itojun Exp $ 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: head/sys/netinet6/ip6_forward.c 185088 2008-11-19 09:39:34Z zec $"); 34 35#include "opt_inet.h" 36#include "opt_inet6.h" 37#include "opt_ipsec.h" 38#include "opt_ipstealth.h" 39 40#include <sys/param.h> 41#include <sys/systm.h> 42#include <sys/malloc.h> 43#include <sys/mbuf.h> 44#include <sys/domain.h> 45#include <sys/protosw.h> 46#include <sys/socket.h> 47#include <sys/errno.h> 48#include <sys/time.h> 49#include <sys/kernel.h> 50#include <sys/syslog.h> 51#include <sys/vimage.h> 52 53#include <net/if.h> 54#include <net/route.h> 55#include <net/pfil.h> 56 57#include <netinet/in.h> 58#include <netinet/in_var.h> 59#include <netinet/in_systm.h> 60#include <netinet/ip.h> 61#include <netinet/ip_var.h> 62#include <netinet6/in6_var.h> 63#include <netinet/ip6.h> 64#include <netinet6/ip6_var.h> 65#include <netinet6/scope6_var.h> 66#include <netinet/icmp6.h> 67#include <netinet6/nd6.h> 68 69#include <netinet/in_pcb.h> 70 71#ifdef IPSEC 72#include <netipsec/ipsec.h> 73#include <netipsec/ipsec6.h> 74#include <netipsec/key.h> 75#endif /* IPSEC */ 76 77#include <netinet6/ip6protosw.h> 78 79#ifdef VIMAGE_GLOBALS 80struct route_in6 ip6_forward_rt; 81#endif 82 83/* 84 * Forward a packet. If some error occurs return the sender 85 * an icmp packet. Note we can't always generate a meaningful 86 * icmp message because icmp doesn't have a large enough repertoire 87 * of codes and types. 88 * 89 * If not forwarding, just drop the packet. This could be confusing 90 * if ipforwarding was zero but some routing protocol was advancing 91 * us as a gateway to somewhere. However, we must let the routing 92 * protocol deal with that. 93 * 94 */ 95void 96ip6_forward(struct mbuf *m, int srcrt) 97{ 98 INIT_VNET_INET6(curvnet); 99 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 100 struct sockaddr_in6 *dst = NULL; 101 struct rtentry *rt = NULL; 102 int error, type = 0, code = 0; 103 struct mbuf *mcopy = NULL; 104 struct ifnet *origifp; /* maybe unnecessary */ 105 u_int32_t inzone, outzone; 106 struct in6_addr src_in6, dst_in6; 107#ifdef IPSEC 108 INIT_VNET_IPSEC(curvnet); 109 struct secpolicy *sp = NULL; 110 int ipsecrt = 0; 111#endif 112 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 113 114 /* GIANT_REQUIRED; */ /* XXX bz: ip6_forward_rt */ 115 116#ifdef IPSEC 117 /* 118 * Check AH/ESP integrity. 119 */ 120 /* 121 * Don't increment ip6s_cantforward because this is the check 122 * before forwarding packet actually. 123 */ 124 if (ipsec6_in_reject(m, NULL)) { 125 V_ipsec6stat.in_polvio++; 126 m_freem(m); 127 return; 128 } 129#endif /* IPSEC */ 130 131 /* 132 * Do not forward packets to multicast destination (should be handled 133 * by ip6_mforward(). 134 * Do not forward packets with unspecified source. It was discussed 135 * in July 2000, on the ipngwg mailing list. 136 */ 137 if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || 138 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 139 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { 140 V_ip6stat.ip6s_cantforward++; 141 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 142 if (V_ip6_log_time + V_ip6_log_interval < time_second) { 143 V_ip6_log_time = time_second; 144 log(LOG_DEBUG, 145 "cannot forward " 146 "from %s to %s nxt %d received on %s\n", 147 ip6_sprintf(ip6bufs, &ip6->ip6_src), 148 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 149 ip6->ip6_nxt, 150 if_name(m->m_pkthdr.rcvif)); 151 } 152 m_freem(m); 153 return; 154 } 155 156#ifdef IPSTEALTH 157 if (!V_ip6stealth) { 158#endif 159 if (ip6->ip6_hlim <= IPV6_HLIMDEC) { 160 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 161 icmp6_error(m, ICMP6_TIME_EXCEEDED, 162 ICMP6_TIME_EXCEED_TRANSIT, 0); 163 return; 164 } 165 ip6->ip6_hlim -= IPV6_HLIMDEC; 166 167#ifdef IPSTEALTH 168 } 169#endif 170 171 /* 172 * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - 173 * size of IPv6 + ICMPv6 headers) bytes of the packet in case 174 * we need to generate an ICMP6 message to the src. 175 * Thanks to M_EXT, in most cases copy will not occur. 176 * 177 * It is important to save it before IPsec processing as IPsec 178 * processing may modify the mbuf. 179 */ 180 mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); 181 182#ifdef IPSEC 183 /* get a security policy for this packet */ 184 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 185 IP_FORWARDING, &error); 186 if (sp == NULL) { 187 V_ipsec6stat.out_inval++; 188 V_ip6stat.ip6s_cantforward++; 189 if (mcopy) { 190#if 0 191 /* XXX: what icmp ? */ 192#else 193 m_freem(mcopy); 194#endif 195 } 196 m_freem(m); 197 return; 198 } 199 200 error = 0; 201 202 /* check policy */ 203 switch (sp->policy) { 204 case IPSEC_POLICY_DISCARD: 205 /* 206 * This packet is just discarded. 207 */ 208 V_ipsec6stat.out_polvio++; 209 V_ip6stat.ip6s_cantforward++; 210 KEY_FREESP(&sp); 211 if (mcopy) { 212#if 0 213 /* XXX: what icmp ? */ 214#else 215 m_freem(mcopy); 216#endif 217 } 218 m_freem(m); 219 return; 220 221 case IPSEC_POLICY_BYPASS: 222 case IPSEC_POLICY_NONE: 223 /* no need to do IPsec. */ 224 KEY_FREESP(&sp); 225 goto skip_ipsec; 226 227 case IPSEC_POLICY_IPSEC: 228 if (sp->req == NULL) { 229 /* XXX should be panic ? */ 230 printf("ip6_forward: No IPsec request specified.\n"); 231 V_ip6stat.ip6s_cantforward++; 232 KEY_FREESP(&sp); 233 if (mcopy) { 234#if 0 235 /* XXX: what icmp ? */ 236#else 237 m_freem(mcopy); 238#endif 239 } 240 m_freem(m); 241 return; 242 } 243 /* do IPsec */ 244 break; 245 246 case IPSEC_POLICY_ENTRUST: 247 default: 248 /* should be panic ?? */ 249 printf("ip6_forward: Invalid policy found. %d\n", sp->policy); 250 KEY_FREESP(&sp); 251 goto skip_ipsec; 252 } 253 254 { 255 struct ipsecrequest *isr = NULL; 256 struct ipsec_output_state state; 257 258 /* 259 * when the kernel forwards a packet, it is not proper to apply 260 * IPsec transport mode to the packet is not proper. this check 261 * avoid from this. 262 * at present, if there is even a transport mode SA request in the 263 * security policy, the kernel does not apply IPsec to the packet. 264 * this check is not enough because the following case is valid. 265 * ipsec esp/tunnel/xxx-xxx/require esp/transport//require; 266 */ 267 for (isr = sp->req; isr; isr = isr->next) { 268 if (isr->saidx.mode == IPSEC_MODE_ANY) 269 goto doipsectunnel; 270 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 271 goto doipsectunnel; 272 } 273 274 /* 275 * if there's no need for tunnel mode IPsec, skip. 276 */ 277 if (!isr) 278 goto skip_ipsec; 279 280 doipsectunnel: 281 /* 282 * All the extension headers will become inaccessible 283 * (since they can be encrypted). 284 * Don't panic, we need no more updates to extension headers 285 * on inner IPv6 packet (since they are now encapsulated). 286 * 287 * IPv6 [ESP|AH] IPv6 [extension headers] payload 288 */ 289 bzero(&state, sizeof(state)); 290 state.m = m; 291 state.ro = NULL; /* update at ipsec6_output_tunnel() */ 292 state.dst = NULL; /* update at ipsec6_output_tunnel() */ 293 294 error = ipsec6_output_tunnel(&state, sp, 0); 295 296 m = state.m; 297 KEY_FREESP(&sp); 298 299 if (error) { 300 /* mbuf is already reclaimed in ipsec6_output_tunnel. */ 301 switch (error) { 302 case EHOSTUNREACH: 303 case ENETUNREACH: 304 case EMSGSIZE: 305 case ENOBUFS: 306 case ENOMEM: 307 break; 308 default: 309 printf("ip6_output (ipsec): error code %d\n", error); 310 /* FALLTHROUGH */ 311 case ENOENT: 312 /* don't show these error codes to the user */ 313 break; 314 } 315 V_ip6stat.ip6s_cantforward++; 316 if (mcopy) { 317#if 0 318 /* XXX: what icmp ? */ 319#else 320 m_freem(mcopy); 321#endif 322 } 323 m_freem(m); 324 return; 325 } else { 326 /* 327 * In the FAST IPSec case we have already 328 * re-injected the packet and it has been freed 329 * by the ipsec_done() function. So, just clean 330 * up after ourselves. 331 */ 332 m = NULL; 333 goto freecopy; 334 } 335 336 if ((m != NULL) && (ip6 != mtod(m, struct ip6_hdr *)) ){ 337 /* 338 * now tunnel mode headers are added. we are originating 339 * packet instead of forwarding the packet. 340 */ 341 ip6_output(m, NULL, NULL, IPV6_FORWARDING/*XXX*/, NULL, NULL, 342 NULL); 343 goto freecopy; 344 } 345 346 /* adjust pointer */ 347 dst = (struct sockaddr_in6 *)state.dst; 348 rt = state.ro ? state.ro->ro_rt : NULL; 349 if (dst != NULL && rt != NULL) 350 ipsecrt = 1; 351 } 352 skip_ipsec: 353#endif /* IPSEC */ 354 355#ifdef IPSEC 356 if (ipsecrt) 357 goto skip_routing; 358#endif 359 360 dst = (struct sockaddr_in6 *)&V_ip6_forward_rt.ro_dst; 361 if (!srcrt) { 362 /* ip6_forward_rt.ro_dst.sin6_addr is equal to ip6->ip6_dst */ 363 if (V_ip6_forward_rt.ro_rt == 0 || 364 (V_ip6_forward_rt.ro_rt->rt_flags & RTF_UP) == 0) { 365 if (V_ip6_forward_rt.ro_rt) { 366 RTFREE(V_ip6_forward_rt.ro_rt); 367 V_ip6_forward_rt.ro_rt = 0; 368 } 369 370 /* this probably fails but give it a try again */ 371 rtalloc((struct route *)&V_ip6_forward_rt); 372 } 373 374 if (V_ip6_forward_rt.ro_rt == 0) { 375 V_ip6stat.ip6s_noroute++; 376 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 377 if (mcopy) { 378 icmp6_error(mcopy, ICMP6_DST_UNREACH, 379 ICMP6_DST_UNREACH_NOROUTE, 0); 380 } 381 m_freem(m); 382 return; 383 } 384 } else if ((rt = V_ip6_forward_rt.ro_rt) == 0 || 385 !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr)) { 386 if (V_ip6_forward_rt.ro_rt) { 387 RTFREE(V_ip6_forward_rt.ro_rt); 388 V_ip6_forward_rt.ro_rt = 0; 389 } 390 bzero(dst, sizeof(*dst)); 391 dst->sin6_len = sizeof(struct sockaddr_in6); 392 dst->sin6_family = AF_INET6; 393 dst->sin6_addr = ip6->ip6_dst; 394 395 rtalloc((struct route *)&V_ip6_forward_rt); 396 if (V_ip6_forward_rt.ro_rt == 0) { 397 V_ip6stat.ip6s_noroute++; 398 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 399 if (mcopy) { 400 icmp6_error(mcopy, ICMP6_DST_UNREACH, 401 ICMP6_DST_UNREACH_NOROUTE, 0); 402 } 403 m_freem(m); 404 return; 405 } 406 } 407 rt = V_ip6_forward_rt.ro_rt; 408#ifdef IPSEC 409 skip_routing:; 410#endif 411 412 /* 413 * Source scope check: if a packet can't be delivered to its 414 * destination for the reason that the destination is beyond the scope 415 * of the source address, discard the packet and return an icmp6 416 * destination unreachable error with Code 2 (beyond scope of source 417 * address). We use a local copy of ip6_src, since in6_setscope() 418 * will possibly modify its first argument. 419 * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1] 420 */ 421 src_in6 = ip6->ip6_src; 422 if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) { 423 /* XXX: this should not happen */ 424 V_ip6stat.ip6s_cantforward++; 425 V_ip6stat.ip6s_badscope++; 426 m_freem(m); 427 return; 428 } 429 if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { 430 V_ip6stat.ip6s_cantforward++; 431 V_ip6stat.ip6s_badscope++; 432 m_freem(m); 433 return; 434 } 435 if (inzone != outzone 436#ifdef IPSEC 437 && !ipsecrt 438#endif 439 ) { 440 V_ip6stat.ip6s_cantforward++; 441 V_ip6stat.ip6s_badscope++; 442 in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); 443 444 if (V_ip6_log_time + V_ip6_log_interval < time_second) { 445 V_ip6_log_time = time_second; 446 log(LOG_DEBUG, 447 "cannot forward " 448 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 449 ip6_sprintf(ip6bufs, &ip6->ip6_src), 450 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 451 ip6->ip6_nxt, 452 if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); 453 } 454 if (mcopy) 455 icmp6_error(mcopy, ICMP6_DST_UNREACH, 456 ICMP6_DST_UNREACH_BEYONDSCOPE, 0); 457 m_freem(m); 458 return; 459 } 460 461 /* 462 * Destination scope check: if a packet is going to break the scope 463 * zone of packet's destination address, discard it. This case should 464 * usually be prevented by appropriately-configured routing table, but 465 * we need an explicit check because we may mistakenly forward the 466 * packet to a different zone by (e.g.) a default route. 467 */ 468 dst_in6 = ip6->ip6_dst; 469 if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || 470 in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || 471 inzone != outzone) { 472 V_ip6stat.ip6s_cantforward++; 473 V_ip6stat.ip6s_badscope++; 474 m_freem(m); 475 return; 476 } 477 478 if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { 479 in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); 480 if (mcopy) { 481 u_long mtu; 482#ifdef IPSEC 483 struct secpolicy *sp; 484 int ipsecerror; 485 size_t ipsechdrsiz; 486#endif /* IPSEC */ 487 488 mtu = IN6_LINKMTU(rt->rt_ifp); 489#ifdef IPSEC 490 /* 491 * When we do IPsec tunnel ingress, we need to play 492 * with the link value (decrement IPsec header size 493 * from mtu value). The code is much simpler than v4 494 * case, as we have the outgoing interface for 495 * encapsulated packet as "rt->rt_ifp". 496 */ 497 sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, 498 IP_FORWARDING, &ipsecerror); 499 if (sp) { 500 ipsechdrsiz = ipsec6_hdrsiz(mcopy, 501 IPSEC_DIR_OUTBOUND, NULL); 502 if (ipsechdrsiz < mtu) 503 mtu -= ipsechdrsiz; 504 } 505 506 /* 507 * if mtu becomes less than minimum MTU, 508 * tell minimum MTU (and I'll need to fragment it). 509 */ 510 if (mtu < IPV6_MMTU) 511 mtu = IPV6_MMTU; 512#endif /* IPSEC */ 513 icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); 514 } 515 m_freem(m); 516 return; 517 } 518 519 if (rt->rt_flags & RTF_GATEWAY) 520 dst = (struct sockaddr_in6 *)rt->rt_gateway; 521 522 /* 523 * If we are to forward the packet using the same interface 524 * as one we got the packet from, perhaps we should send a redirect 525 * to sender to shortcut a hop. 526 * Only send redirect if source is sending directly to us, 527 * and if packet was not source routed (or has any options). 528 * Also, don't send redirect if forwarding using a route 529 * modified by a redirect. 530 */ 531 if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && 532#ifdef IPSEC 533 !ipsecrt && 534#endif /* IPSEC */ 535 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { 536 if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { 537 /* 538 * If the incoming interface is equal to the outgoing 539 * one, and the link attached to the interface is 540 * point-to-point, then it will be highly probable 541 * that a routing loop occurs. Thus, we immediately 542 * drop the packet and send an ICMPv6 error message. 543 * 544 * type/code is based on suggestion by Rich Draves. 545 * not sure if it is the best pick. 546 */ 547 icmp6_error(mcopy, ICMP6_DST_UNREACH, 548 ICMP6_DST_UNREACH_ADDR, 0); 549 m_freem(m); 550 return; 551 } 552 type = ND_REDIRECT; 553 } 554 555 /* 556 * Fake scoped addresses. Note that even link-local source or 557 * destinaion can appear, if the originating node just sends the 558 * packet to us (without address resolution for the destination). 559 * Since both icmp6_error and icmp6_redirect_output fill the embedded 560 * link identifiers, we can do this stuff after making a copy for 561 * returning an error. 562 */ 563 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { 564 /* 565 * See corresponding comments in ip6_output. 566 * XXX: but is it possible that ip6_forward() sends a packet 567 * to a loopback interface? I don't think so, and thus 568 * I bark here. (jinmei@kame.net) 569 * XXX: it is common to route invalid packets to loopback. 570 * also, the codepath will be visited on use of ::1 in 571 * rthdr. (itojun) 572 */ 573#if 1 574 if (0) 575#else 576 if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) 577#endif 578 { 579 printf("ip6_forward: outgoing interface is loopback. " 580 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 581 ip6_sprintf(ip6bufs, &ip6->ip6_src), 582 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 583 ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), 584 if_name(rt->rt_ifp)); 585 } 586 587 /* we can just use rcvif in forwarding. */ 588 origifp = m->m_pkthdr.rcvif; 589 } 590 else 591 origifp = rt->rt_ifp; 592 /* 593 * clear embedded scope identifiers if necessary. 594 * in6_clearscope will touch the addresses only when necessary. 595 */ 596 in6_clearscope(&ip6->ip6_src); 597 in6_clearscope(&ip6->ip6_dst); 598 599 /* Jump over all PFIL processing if hooks are not active. */ 600 if (!PFIL_HOOKED(&inet6_pfil_hook)) 601 goto pass; 602 603 /* Run through list of hooks for output packets. */ 604 error = pfil_run_hooks(&inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL); 605 if (error != 0) 606 goto senderr; 607 if (m == NULL) 608 goto freecopy; 609 ip6 = mtod(m, struct ip6_hdr *); 610 611pass: 612 error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); 613 if (error) { 614 in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); 615 V_ip6stat.ip6s_cantforward++; 616 } else { 617 V_ip6stat.ip6s_forward++; 618 in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); 619 if (type) 620 V_ip6stat.ip6s_redirectsent++; 621 else { 622 if (mcopy) 623 goto freecopy; 624 } 625 } 626 627senderr: 628 if (mcopy == NULL) 629 return; 630 switch (error) { 631 case 0: 632 if (type == ND_REDIRECT) { 633 icmp6_redirect_output(mcopy, rt); 634 return; 635 } 636 goto freecopy; 637 638 case EMSGSIZE: 639 /* xxx MTU is constant in PPP? */ 640 goto freecopy; 641 642 case ENOBUFS: 643 /* Tell source to slow down like source quench in IP? */ 644 goto freecopy; 645 646 case ENETUNREACH: /* shouldn't happen, checked above */ 647 case EHOSTUNREACH: 648 case ENETDOWN: 649 case EHOSTDOWN: 650 default: 651 type = ICMP6_DST_UNREACH; 652 code = ICMP6_DST_UNREACH_ADDR; 653 break; 654 } 655 icmp6_error(mcopy, type, code, 0); 656 return; 657 658 freecopy: 659 m_freem(mcopy); 660 return; 661} 662