ip6_forward.c revision 171133
1/* $FreeBSD: head/sys/netinet6/ip6_forward.c 171133 2007-07-01 11:41:27Z gnn $ */ 2/* $KAME: ip6_forward.c,v 1.69 2001/05/17 03:48:30 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#include "opt_inet.h" 34#include "opt_inet6.h" 35#include "opt_ipsec.h" 36#include "opt_ipstealth.h" 37 38#include <sys/param.h> 39#include <sys/systm.h> 40#include <sys/malloc.h> 41#include <sys/mbuf.h> 42#include <sys/domain.h> 43#include <sys/protosw.h> 44#include <sys/socket.h> 45#include <sys/errno.h> 46#include <sys/time.h> 47#include <sys/kernel.h> 48#include <sys/syslog.h> 49 50#include <net/if.h> 51#include <net/route.h> 52#include <net/pfil.h> 53 54#include <netinet/in.h> 55#include <netinet/in_var.h> 56#include <netinet/in_systm.h> 57#include <netinet/ip.h> 58#include <netinet/ip_var.h> 59#include <netinet6/in6_var.h> 60#include <netinet/ip6.h> 61#include <netinet6/ip6_var.h> 62#include <netinet6/scope6_var.h> 63#include <netinet/icmp6.h> 64#include <netinet6/nd6.h> 65 66#include <netinet/in_pcb.h> 67 68#ifdef FAST_IPSEC 69#include <netipsec/ipsec.h> 70#include <netipsec/ipsec6.h> 71#include <netipsec/key.h> 72#endif /* FAST_IPSEC */ 73 74#include <netinet6/ip6protosw.h> 75 76struct route_in6 ip6_forward_rt; 77 78/* 79 * Forward a packet. If some error occurs return the sender 80 * an icmp packet. Note we can't always generate a meaningful 81 * icmp message because icmp doesn't have a large enough repertoire 82 * of codes and types. 83 * 84 * If not forwarding, just drop the packet. This could be confusing 85 * if ipforwarding was zero but some routing protocol was advancing 86 * us as a gateway to somewhere. However, we must let the routing 87 * protocol deal with that. 88 * 89 */ 90 91void 92ip6_forward(m, srcrt) 93 struct mbuf *m; 94 int srcrt; 95{ 96 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 97 struct sockaddr_in6 *dst = NULL; 98 struct rtentry *rt = NULL; 99 int error, type = 0, code = 0; 100 struct mbuf *mcopy = NULL; 101 struct ifnet *origifp; /* maybe unnecessary */ 102 u_int32_t inzone, outzone; 103 struct in6_addr src_in6, dst_in6; 104#ifdef FAST_IPSEC 105 struct secpolicy *sp = NULL; 106 int ipsecrt = 0; 107#endif 108 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 109 110 GIANT_REQUIRED; /* XXX bz: ip6_forward_rt */ 111 112#ifdef FAST_IPSEC 113 /* 114 * Check AH/ESP integrity. 115 */ 116 /* 117 * Don't increment ip6s_cantforward because this is the check 118 * before forwarding packet actually. 119 */ 120 if (ipsec6_in_reject(m, NULL)) { 121 ipsec6stat.in_polvio++; 122 m_freem(m); 123 return; 124 } 125#endif /* FAST_IPSEC */ 126 127 /* 128 * Do not forward packets to multicast destination (should be handled 129 * by ip6_mforward(). 130 * Do not forward packets with unspecified source. It was discussed 131 * in July 2000, on the ipngwg mailing list. 132 */ 133 if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || 134 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 135 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { 136 ip6stat.ip6s_cantforward++; 137 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 138 if (ip6_log_time + ip6_log_interval < time_second) { 139 ip6_log_time = time_second; 140 log(LOG_DEBUG, 141 "cannot forward " 142 "from %s to %s nxt %d received on %s\n", 143 ip6_sprintf(ip6bufs, &ip6->ip6_src), 144 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 145 ip6->ip6_nxt, 146 if_name(m->m_pkthdr.rcvif)); 147 } 148 m_freem(m); 149 return; 150 } 151 152#ifdef IPSTEALTH 153 if (!ip6stealth) { 154#endif 155 if (ip6->ip6_hlim <= IPV6_HLIMDEC) { 156 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 157 icmp6_error(m, ICMP6_TIME_EXCEEDED, 158 ICMP6_TIME_EXCEED_TRANSIT, 0); 159 return; 160 } 161 ip6->ip6_hlim -= IPV6_HLIMDEC; 162 163#ifdef IPSTEALTH 164 } 165#endif 166 167 /* 168 * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - 169 * size of IPv6 + ICMPv6 headers) bytes of the packet in case 170 * we need to generate an ICMP6 message to the src. 171 * Thanks to M_EXT, in most cases copy will not occur. 172 * 173 * It is important to save it before IPsec processing as IPsec 174 * processing may modify the mbuf. 175 */ 176 mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); 177 178#ifdef FAST_IPSEC 179 /* get a security policy for this packet */ 180 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 181 IP_FORWARDING, &error); 182 if (sp == NULL) { 183 ipsec6stat.out_inval++; 184 ip6stat.ip6s_cantforward++; 185 if (mcopy) { 186#if 0 187 /* XXX: what icmp ? */ 188#else 189 m_freem(mcopy); 190#endif 191 } 192 m_freem(m); 193 return; 194 } 195 196 error = 0; 197 198 /* check policy */ 199 switch (sp->policy) { 200 case IPSEC_POLICY_DISCARD: 201 /* 202 * This packet is just discarded. 203 */ 204 ipsec6stat.out_polvio++; 205 ip6stat.ip6s_cantforward++; 206 KEY_FREESP(&sp); 207 if (mcopy) { 208#if 0 209 /* XXX: what icmp ? */ 210#else 211 m_freem(mcopy); 212#endif 213 } 214 m_freem(m); 215 return; 216 217 case IPSEC_POLICY_BYPASS: 218 case IPSEC_POLICY_NONE: 219 /* no need to do IPsec. */ 220 KEY_FREESP(&sp); 221 goto skip_ipsec; 222 223 case IPSEC_POLICY_IPSEC: 224 if (sp->req == NULL) { 225 /* XXX should be panic ? */ 226 printf("ip6_forward: No IPsec request specified.\n"); 227 ip6stat.ip6s_cantforward++; 228 KEY_FREESP(&sp); 229 if (mcopy) { 230#if 0 231 /* XXX: what icmp ? */ 232#else 233 m_freem(mcopy); 234#endif 235 } 236 m_freem(m); 237 return; 238 } 239 /* do IPsec */ 240 break; 241 242 case IPSEC_POLICY_ENTRUST: 243 default: 244 /* should be panic ?? */ 245 printf("ip6_forward: Invalid policy found. %d\n", sp->policy); 246 KEY_FREESP(&sp); 247 goto skip_ipsec; 248 } 249 250 { 251 struct ipsecrequest *isr = NULL; 252 struct ipsec_output_state state; 253 254 /* 255 * when the kernel forwards a packet, it is not proper to apply 256 * IPsec transport mode to the packet is not proper. this check 257 * avoid from this. 258 * at present, if there is even a transport mode SA request in the 259 * security policy, the kernel does not apply IPsec to the packet. 260 * this check is not enough because the following case is valid. 261 * ipsec esp/tunnel/xxx-xxx/require esp/transport//require; 262 */ 263 for (isr = sp->req; isr; isr = isr->next) { 264 if (isr->saidx.mode == IPSEC_MODE_ANY) 265 goto doipsectunnel; 266 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 267 goto doipsectunnel; 268 } 269 270 /* 271 * if there's no need for tunnel mode IPsec, skip. 272 */ 273 if (!isr) 274 goto skip_ipsec; 275 276 doipsectunnel: 277 /* 278 * All the extension headers will become inaccessible 279 * (since they can be encrypted). 280 * Don't panic, we need no more updates to extension headers 281 * on inner IPv6 packet (since they are now encapsulated). 282 * 283 * IPv6 [ESP|AH] IPv6 [extension headers] payload 284 */ 285 bzero(&state, sizeof(state)); 286 state.m = m; 287 state.ro = NULL; /* update at ipsec6_output_tunnel() */ 288 state.dst = NULL; /* update at ipsec6_output_tunnel() */ 289 290 error = ipsec6_output_tunnel(&state, sp, 0); 291 292 m = state.m; 293 KEY_FREESP(&sp); 294 295 if (error) { 296 /* mbuf is already reclaimed in ipsec6_output_tunnel. */ 297 switch (error) { 298 case EHOSTUNREACH: 299 case ENETUNREACH: 300 case EMSGSIZE: 301 case ENOBUFS: 302 case ENOMEM: 303 break; 304 default: 305 printf("ip6_output (ipsec): error code %d\n", error); 306 /* FALLTHROUGH */ 307 case ENOENT: 308 /* don't show these error codes to the user */ 309 break; 310 } 311 ip6stat.ip6s_cantforward++; 312 if (mcopy) { 313#if 0 314 /* XXX: what icmp ? */ 315#else 316 m_freem(mcopy); 317#endif 318 } 319 m_freem(m); 320 return; 321 } else { 322 /* 323 * In the FAST IPSec case we have already 324 * re-injected the packet and it has been freed 325 * by the ipsec_done() function. So, just clean 326 * up after ourselves. 327 */ 328 m = NULL; 329 goto freecopy; 330 } 331 332 if ((m != NULL) && (ip6 != mtod(m, struct ip6_hdr *)) ){ 333 /* 334 * now tunnel mode headers are added. we are originating 335 * packet instead of forwarding the packet. 336 */ 337 ip6_output(m, NULL, NULL, IPV6_FORWARDING/*XXX*/, NULL, NULL, 338 NULL); 339 goto freecopy; 340 } 341 342 /* adjust pointer */ 343 dst = (struct sockaddr_in6 *)state.dst; 344 rt = state.ro ? state.ro->ro_rt : NULL; 345 if (dst != NULL && rt != NULL) 346 ipsecrt = 1; 347 } 348 skip_ipsec: 349#endif /* FAST_IPSEC */ 350 351#ifdef FAST_IPSEC 352 if (ipsecrt) 353 goto skip_routing; 354#endif 355 356 dst = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 357 if (!srcrt) { 358 /* ip6_forward_rt.ro_dst.sin6_addr is equal to ip6->ip6_dst */ 359 if (ip6_forward_rt.ro_rt == 0 || 360 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) == 0) { 361 if (ip6_forward_rt.ro_rt) { 362 RTFREE(ip6_forward_rt.ro_rt); 363 ip6_forward_rt.ro_rt = 0; 364 } 365 366 /* this probably fails but give it a try again */ 367 rtalloc((struct route *)&ip6_forward_rt); 368 } 369 370 if (ip6_forward_rt.ro_rt == 0) { 371 ip6stat.ip6s_noroute++; 372 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 373 if (mcopy) { 374 icmp6_error(mcopy, ICMP6_DST_UNREACH, 375 ICMP6_DST_UNREACH_NOROUTE, 0); 376 } 377 m_freem(m); 378 return; 379 } 380 } else if ((rt = ip6_forward_rt.ro_rt) == 0 || 381 !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr)) { 382 if (ip6_forward_rt.ro_rt) { 383 RTFREE(ip6_forward_rt.ro_rt); 384 ip6_forward_rt.ro_rt = 0; 385 } 386 bzero(dst, sizeof(*dst)); 387 dst->sin6_len = sizeof(struct sockaddr_in6); 388 dst->sin6_family = AF_INET6; 389 dst->sin6_addr = ip6->ip6_dst; 390 391 rtalloc((struct route *)&ip6_forward_rt); 392 if (ip6_forward_rt.ro_rt == 0) { 393 ip6stat.ip6s_noroute++; 394 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 395 if (mcopy) { 396 icmp6_error(mcopy, ICMP6_DST_UNREACH, 397 ICMP6_DST_UNREACH_NOROUTE, 0); 398 } 399 m_freem(m); 400 return; 401 } 402 } 403 rt = ip6_forward_rt.ro_rt; 404#ifdef FAST_IPSEC 405 skip_routing:; 406#endif 407 408 /* 409 * Source scope check: if a packet can't be delivered to its 410 * destination for the reason that the destination is beyond the scope 411 * of the source address, discard the packet and return an icmp6 412 * destination unreachable error with Code 2 (beyond scope of source 413 * address). We use a local copy of ip6_src, since in6_setscope() 414 * will possibly modify its first argument. 415 * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1] 416 */ 417 src_in6 = ip6->ip6_src; 418 if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) { 419 /* XXX: this should not happen */ 420 ip6stat.ip6s_cantforward++; 421 ip6stat.ip6s_badscope++; 422 m_freem(m); 423 return; 424 } 425 if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { 426 ip6stat.ip6s_cantforward++; 427 ip6stat.ip6s_badscope++; 428 m_freem(m); 429 return; 430 } 431 if (inzone != outzone 432#ifdef FAST_IPSEC 433 && !ipsecrt 434#endif 435 ) { 436 ip6stat.ip6s_cantforward++; 437 ip6stat.ip6s_badscope++; 438 in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); 439 440 if (ip6_log_time + ip6_log_interval < time_second) { 441 ip6_log_time = time_second; 442 log(LOG_DEBUG, 443 "cannot forward " 444 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 445 ip6_sprintf(ip6bufs, &ip6->ip6_src), 446 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 447 ip6->ip6_nxt, 448 if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); 449 } 450 if (mcopy) 451 icmp6_error(mcopy, ICMP6_DST_UNREACH, 452 ICMP6_DST_UNREACH_BEYONDSCOPE, 0); 453 m_freem(m); 454 return; 455 } 456 457 /* 458 * Destination scope check: if a packet is going to break the scope 459 * zone of packet's destination address, discard it. This case should 460 * usually be prevented by appropriately-configured routing table, but 461 * we need an explicit check because we may mistakenly forward the 462 * packet to a different zone by (e.g.) a default route. 463 */ 464 dst_in6 = ip6->ip6_dst; 465 if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || 466 in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || 467 inzone != outzone) { 468 ip6stat.ip6s_cantforward++; 469 ip6stat.ip6s_badscope++; 470 m_freem(m); 471 return; 472 } 473 474 if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { 475 in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); 476 if (mcopy) { 477 u_long mtu; 478#ifdef FAST_IPSEC 479 struct secpolicy *sp; 480 int ipsecerror; 481 size_t ipsechdrsiz; 482#endif /* FAST_IPSEC */ 483 484 mtu = IN6_LINKMTU(rt->rt_ifp); 485#ifdef FAST_IPSEC 486 /* 487 * When we do IPsec tunnel ingress, we need to play 488 * with the link value (decrement IPsec header size 489 * from mtu value). The code is much simpler than v4 490 * case, as we have the outgoing interface for 491 * encapsulated packet as "rt->rt_ifp". 492 */ 493 sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, 494 IP_FORWARDING, &ipsecerror); 495 if (sp) { 496 ipsechdrsiz = ipsec6_hdrsiz(mcopy, 497 IPSEC_DIR_OUTBOUND, NULL); 498 if (ipsechdrsiz < mtu) 499 mtu -= ipsechdrsiz; 500 } 501 502 /* 503 * if mtu becomes less than minimum MTU, 504 * tell minimum MTU (and I'll need to fragment it). 505 */ 506 if (mtu < IPV6_MMTU) 507 mtu = IPV6_MMTU; 508#endif /* FAST_IPSEC */ 509 icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); 510 } 511 m_freem(m); 512 return; 513 } 514 515 if (rt->rt_flags & RTF_GATEWAY) 516 dst = (struct sockaddr_in6 *)rt->rt_gateway; 517 518 /* 519 * If we are to forward the packet using the same interface 520 * as one we got the packet from, perhaps we should send a redirect 521 * to sender to shortcut a hop. 522 * Only send redirect if source is sending directly to us, 523 * and if packet was not source routed (or has any options). 524 * Also, don't send redirect if forwarding using a route 525 * modified by a redirect. 526 */ 527 if (ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && 528#ifdef FAST_IPSEC 529 !ipsecrt && 530#endif /* FAST_IPSEC */ 531 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { 532 if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { 533 /* 534 * If the incoming interface is equal to the outgoing 535 * one, and the link attached to the interface is 536 * point-to-point, then it will be highly probable 537 * that a routing loop occurs. Thus, we immediately 538 * drop the packet and send an ICMPv6 error message. 539 * 540 * type/code is based on suggestion by Rich Draves. 541 * not sure if it is the best pick. 542 */ 543 icmp6_error(mcopy, ICMP6_DST_UNREACH, 544 ICMP6_DST_UNREACH_ADDR, 0); 545 m_freem(m); 546 return; 547 } 548 type = ND_REDIRECT; 549 } 550 551 /* 552 * Fake scoped addresses. Note that even link-local source or 553 * destinaion can appear, if the originating node just sends the 554 * packet to us (without address resolution for the destination). 555 * Since both icmp6_error and icmp6_redirect_output fill the embedded 556 * link identifiers, we can do this stuff after making a copy for 557 * returning an error. 558 */ 559 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { 560 /* 561 * See corresponding comments in ip6_output. 562 * XXX: but is it possible that ip6_forward() sends a packet 563 * to a loopback interface? I don't think so, and thus 564 * I bark here. (jinmei@kame.net) 565 * XXX: it is common to route invalid packets to loopback. 566 * also, the codepath will be visited on use of ::1 in 567 * rthdr. (itojun) 568 */ 569#if 1 570 if (0) 571#else 572 if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) 573#endif 574 { 575 printf("ip6_forward: outgoing interface is loopback. " 576 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 577 ip6_sprintf(ip6bufs, &ip6->ip6_src), 578 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 579 ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), 580 if_name(rt->rt_ifp)); 581 } 582 583 /* we can just use rcvif in forwarding. */ 584 origifp = m->m_pkthdr.rcvif; 585 } 586 else 587 origifp = rt->rt_ifp; 588 /* 589 * clear embedded scope identifiers if necessary. 590 * in6_clearscope will touch the addresses only when necessary. 591 */ 592 in6_clearscope(&ip6->ip6_src); 593 in6_clearscope(&ip6->ip6_dst); 594 595 /* Jump over all PFIL processing if hooks are not active. */ 596 if (!PFIL_HOOKED(&inet6_pfil_hook)) 597 goto pass; 598 599 /* Run through list of hooks for output packets. */ 600 error = pfil_run_hooks(&inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL); 601 if (error != 0) 602 goto senderr; 603 if (m == NULL) 604 goto freecopy; 605 ip6 = mtod(m, struct ip6_hdr *); 606 607pass: 608 error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); 609 if (error) { 610 in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); 611 ip6stat.ip6s_cantforward++; 612 } else { 613 ip6stat.ip6s_forward++; 614 in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); 615 if (type) 616 ip6stat.ip6s_redirectsent++; 617 else { 618 if (mcopy) 619 goto freecopy; 620 } 621 } 622 623senderr: 624 if (mcopy == NULL) 625 return; 626 switch (error) { 627 case 0: 628 if (type == ND_REDIRECT) { 629 icmp6_redirect_output(mcopy, rt); 630 return; 631 } 632 goto freecopy; 633 634 case EMSGSIZE: 635 /* xxx MTU is constant in PPP? */ 636 goto freecopy; 637 638 case ENOBUFS: 639 /* Tell source to slow down like source quench in IP? */ 640 goto freecopy; 641 642 case ENETUNREACH: /* shouldn't happen, checked above */ 643 case EHOSTUNREACH: 644 case ENETDOWN: 645 case EHOSTDOWN: 646 default: 647 type = ICMP6_DST_UNREACH; 648 code = ICMP6_DST_UNREACH_ADDR; 649 break; 650 } 651 icmp6_error(mcopy, type, code, 0); 652 return; 653 654 freecopy: 655 m_freem(mcopy); 656 return; 657} 658