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("$FreeBSD$"); 34 35 #include "opt_inet.h" 36 #include "opt_inet6.h" 37 #include "opt_ipfw.h" 38 #include "opt_ipsec.h" 39 #include "opt_ipstealth.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/malloc.h> 44 #include <sys/mbuf.h> 45 #include <sys/domain.h> 46 #include <sys/protosw.h> 47 #include <sys/socket.h> 48 #include <sys/errno.h> 49 #include <sys/time.h> 50 #include <sys/kernel.h> 51 #include <sys/syslog.h> 52 53 #include <net/if.h> 54 #include <net/if_var.h> 55 #include <net/netisr.h> 56 #include <net/route.h> 57 #include <net/pfil.h> 58 59 #include <netinet/in.h> 60 #include <netinet/in_var.h> 61 #include <netinet/in_systm.h> 62 #include <netinet/ip.h> 63 #include <netinet/ip_var.h> 64 #include <netinet6/in6_var.h> 65 #include <netinet/ip6.h> 66 #include <netinet6/ip6_var.h> 67 #include <netinet6/scope6_var.h> 68 #include <netinet/icmp6.h> 69 #include <netinet6/nd6.h> 70 71 #include <netinet/in_pcb.h> 72 73 #ifdef IPSEC 74 #include <netipsec/ipsec.h> 75 #include <netipsec/ipsec6.h> 76 #include <netipsec/key.h> 77 #endif /* IPSEC */ 78 79 /* 80 * Forward a packet. If some error occurs return the sender 81 * an icmp packet. Note we can't always generate a meaningful 82 * icmp message because icmp doesn't have a large enough repertoire 83 * of codes and types. 84 * 85 * If not forwarding, just drop the packet. This could be confusing 86 * if ipforwarding was zero but some routing protocol was advancing 87 * us as a gateway to somewhere. However, we must let the routing 88 * protocol deal with that. 89 * 90 */ 91 void 92 ip6_forward(struct mbuf *m, int srcrt) 93 { 94 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 95 struct sockaddr_in6 *dst = NULL; 96 struct rtentry *rt = NULL; 97 struct route_in6 rin6; 98 int error, type = 0, code = 0; 99 struct mbuf *mcopy = NULL; 100 struct ifnet *origifp; /* maybe unnecessary */ 101 u_int32_t inzone, outzone; 102 struct in6_addr src_in6, dst_in6, odst; 103 #ifdef IPSEC 104 struct secpolicy *sp = NULL; 105 #endif 106 #ifdef SCTP 107 int sw_csum; 108 #endif 109 struct m_tag *fwd_tag; 110 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 111 112 #ifdef 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_INC(ips_in_polvio); 122 m_freem(m); 123 return; 124 } 125 #endif /* 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_INC(ip6s_cantforward); 137 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 138 if (V_ip6_log_time + V_ip6_log_interval < time_uptime) { 139 V_ip6_log_time = time_uptime; 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 (!V_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 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_INC(ips_out_inval); 184 IP6STAT_INC(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_INC(ips_out_polvio); 205 IP6STAT_INC(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_INC(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; 252 253 /* 254 * when the kernel forwards a packet, it is not proper to apply 255 * IPsec transport mode to the packet is not proper. this check 256 * avoid from this. 257 * at present, if there is even a transport mode SA request in the 258 * security policy, the kernel does not apply IPsec to the packet. 259 * this check is not enough because the following case is valid. 260 * ipsec esp/tunnel/xxx-xxx/require esp/transport//require; 261 */ 262 for (isr = sp->req; isr; isr = isr->next) { 263 if (isr->saidx.mode == IPSEC_MODE_ANY) 264 goto doipsectunnel; 265 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 266 goto doipsectunnel; 267 } 268 269 /* 270 * if there's no need for tunnel mode IPsec, skip. 271 */ 272 if (!isr) 273 goto skip_ipsec; 274 275 doipsectunnel: 276 /* 277 * All the extension headers will become inaccessible 278 * (since they can be encrypted). 279 * Don't panic, we need no more updates to extension headers 280 * on inner IPv6 packet (since they are now encapsulated). 281 * 282 * IPv6 [ESP|AH] IPv6 [extension headers] payload 283 */ 284 285 /* 286 * If we need to encapsulate the packet, do it here 287 * ipsec6_proces_packet will send the packet using ip6_output 288 */ 289 error = ipsec6_process_packet(m, sp->req); 290 291 KEY_FREESP(&sp); 292 293 if (error == EJUSTRETURN) { 294 /* 295 * We had a SP with a level of 'use' and no SA. We 296 * will just continue to process the packet without 297 * IPsec processing. 298 */ 299 error = 0; 300 goto skip_ipsec; 301 } 302 303 if (error) { 304 /* mbuf is already reclaimed in ipsec6_process_packet. */ 305 switch (error) { 306 case EHOSTUNREACH: 307 case ENETUNREACH: 308 case EMSGSIZE: 309 case ENOBUFS: 310 case ENOMEM: 311 break; 312 default: 313 printf("ip6_output (ipsec): error code %d\n", error); 314 /* FALLTHROUGH */ 315 case ENOENT: 316 /* don't show these error codes to the user */ 317 break; 318 } 319 IP6STAT_INC(ip6s_cantforward); 320 if (mcopy) { 321 #if 0 322 /* XXX: what icmp ? */ 323 #else 324 m_freem(mcopy); 325 #endif 326 } 327 return; 328 } else { 329 /* 330 * In the FAST IPSec case we have already 331 * re-injected the packet and it has been freed 332 * by the ipsec_done() function. So, just clean 333 * up after ourselves. 334 */ 335 m = NULL; 336 goto freecopy; 337 } 338 } 339 skip_ipsec: 340 #endif 341 again: 342 bzero(&rin6, sizeof(struct route_in6)); 343 dst = (struct sockaddr_in6 *)&rin6.ro_dst; 344 dst->sin6_len = sizeof(struct sockaddr_in6); 345 dst->sin6_family = AF_INET6; 346 dst->sin6_addr = ip6->ip6_dst; 347 again2: 348 rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m)); 349 if (rin6.ro_rt != NULL) 350 RT_UNLOCK(rin6.ro_rt); 351 else { 352 IP6STAT_INC(ip6s_noroute); 353 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 354 if (mcopy) { 355 icmp6_error(mcopy, ICMP6_DST_UNREACH, 356 ICMP6_DST_UNREACH_NOROUTE, 0); 357 } 358 goto bad; 359 } 360 rt = rin6.ro_rt; 361 362 /* 363 * Source scope check: if a packet can't be delivered to its 364 * destination for the reason that the destination is beyond the scope 365 * of the source address, discard the packet and return an icmp6 366 * destination unreachable error with Code 2 (beyond scope of source 367 * address). We use a local copy of ip6_src, since in6_setscope() 368 * will possibly modify its first argument. 369 * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1] 370 */ 371 src_in6 = ip6->ip6_src; 372 if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) { 373 /* XXX: this should not happen */ 374 IP6STAT_INC(ip6s_cantforward); 375 IP6STAT_INC(ip6s_badscope); 376 goto bad; 377 } 378 if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { 379 IP6STAT_INC(ip6s_cantforward); 380 IP6STAT_INC(ip6s_badscope); 381 goto bad; 382 } 383 if (inzone != outzone) { 384 IP6STAT_INC(ip6s_cantforward); 385 IP6STAT_INC(ip6s_badscope); 386 in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); 387 388 if (V_ip6_log_time + V_ip6_log_interval < time_uptime) { 389 V_ip6_log_time = time_uptime; 390 log(LOG_DEBUG, 391 "cannot forward " 392 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 393 ip6_sprintf(ip6bufs, &ip6->ip6_src), 394 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 395 ip6->ip6_nxt, 396 if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); 397 } 398 if (mcopy) 399 icmp6_error(mcopy, ICMP6_DST_UNREACH, 400 ICMP6_DST_UNREACH_BEYONDSCOPE, 0); 401 goto bad; 402 } 403 404 /* 405 * Destination scope check: if a packet is going to break the scope 406 * zone of packet's destination address, discard it. This case should 407 * usually be prevented by appropriately-configured routing table, but 408 * we need an explicit check because we may mistakenly forward the 409 * packet to a different zone by (e.g.) a default route. 410 */ 411 dst_in6 = ip6->ip6_dst; 412 if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || 413 in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || 414 inzone != outzone) { 415 IP6STAT_INC(ip6s_cantforward); 416 IP6STAT_INC(ip6s_badscope); 417 goto bad; 418 } 419 420 if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { 421 in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); 422 if (mcopy) { 423 u_long mtu; 424 #ifdef IPSEC 425 size_t ipsechdrsiz; 426 #endif /* IPSEC */ 427 428 mtu = IN6_LINKMTU(rt->rt_ifp); 429 #ifdef IPSEC 430 /* 431 * When we do IPsec tunnel ingress, we need to play 432 * with the link value (decrement IPsec header size 433 * from mtu value). The code is much simpler than v4 434 * case, as we have the outgoing interface for 435 * encapsulated packet as "rt->rt_ifp". 436 */ 437 ipsechdrsiz = ipsec_hdrsiz(mcopy, IPSEC_DIR_OUTBOUND, 438 NULL); 439 if (ipsechdrsiz < mtu) 440 mtu -= ipsechdrsiz; 441 /* 442 * if mtu becomes less than minimum MTU, 443 * tell minimum MTU (and I'll need to fragment it). 444 */ 445 if (mtu < IPV6_MMTU) 446 mtu = IPV6_MMTU; 447 #endif /* IPSEC */ 448 icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); 449 } 450 goto bad; 451 } 452 453 if (rt->rt_flags & RTF_GATEWAY) 454 dst = (struct sockaddr_in6 *)rt->rt_gateway; 455 456 /* 457 * If we are to forward the packet using the same interface 458 * as one we got the packet from, perhaps we should send a redirect 459 * to sender to shortcut a hop. 460 * Only send redirect if source is sending directly to us, 461 * and if packet was not source routed (or has any options). 462 * Also, don't send redirect if forwarding using a route 463 * modified by a redirect. 464 */ 465 if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && 466 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { 467 if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { 468 /* 469 * If the incoming interface is equal to the outgoing 470 * one, and the link attached to the interface is 471 * point-to-point, then it will be highly probable 472 * that a routing loop occurs. Thus, we immediately 473 * drop the packet and send an ICMPv6 error message. 474 * 475 * type/code is based on suggestion by Rich Draves. 476 * not sure if it is the best pick. 477 */ 478 icmp6_error(mcopy, ICMP6_DST_UNREACH, 479 ICMP6_DST_UNREACH_ADDR, 0); 480 goto bad; 481 } 482 type = ND_REDIRECT; 483 } 484 485 /* 486 * Fake scoped addresses. Note that even link-local source or 487 * destinaion can appear, if the originating node just sends the 488 * packet to us (without address resolution for the destination). 489 * Since both icmp6_error and icmp6_redirect_output fill the embedded 490 * link identifiers, we can do this stuff after making a copy for 491 * returning an error. 492 */ 493 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { 494 /* 495 * See corresponding comments in ip6_output. 496 * XXX: but is it possible that ip6_forward() sends a packet 497 * to a loopback interface? I don't think so, and thus 498 * I bark here. (jinmei@kame.net) 499 * XXX: it is common to route invalid packets to loopback. 500 * also, the codepath will be visited on use of ::1 in 501 * rthdr. (itojun) 502 */ 503 #if 1 504 if (0) 505 #else 506 if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) 507 #endif 508 { 509 printf("ip6_forward: outgoing interface is loopback. " 510 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 511 ip6_sprintf(ip6bufs, &ip6->ip6_src), 512 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 513 ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), 514 if_name(rt->rt_ifp)); 515 } 516 517 /* we can just use rcvif in forwarding. */ 518 origifp = m->m_pkthdr.rcvif; 519 } 520 else 521 origifp = rt->rt_ifp; 522 /* 523 * clear embedded scope identifiers if necessary. 524 * in6_clearscope will touch the addresses only when necessary. 525 */ 526 in6_clearscope(&ip6->ip6_src); 527 in6_clearscope(&ip6->ip6_dst); 528 529 /* Jump over all PFIL processing if hooks are not active. */ 530 if (!PFIL_HOOKED(&V_inet6_pfil_hook)) 531 goto pass; 532 533 odst = ip6->ip6_dst; 534 /* Run through list of hooks for output packets. */ 535 error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL); 536 if (error != 0 || m == NULL) 537 goto freecopy; /* consumed by filter */ 538 ip6 = mtod(m, struct ip6_hdr *); 539 540 /* See if destination IP address was changed by packet filter. */ 541 if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) { 542 m->m_flags |= M_SKIP_FIREWALL; 543 /* If destination is now ourself drop to ip6_input(). */ 544 if (in6_localip(&ip6->ip6_dst)) { 545 m->m_flags |= M_FASTFWD_OURS; 546 if (m->m_pkthdr.rcvif == NULL) 547 m->m_pkthdr.rcvif = V_loif; 548 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 549 m->m_pkthdr.csum_flags |= 550 CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR; 551 m->m_pkthdr.csum_data = 0xffff; 552 } 553 #ifdef SCTP 554 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) 555 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 556 #endif 557 error = netisr_queue(NETISR_IPV6, m); 558 goto out; 559 } else 560 goto again; /* Redo the routing table lookup. */ 561 } 562 563 /* See if local, if yes, send it to netisr. */ 564 if (m->m_flags & M_FASTFWD_OURS) { 565 if (m->m_pkthdr.rcvif == NULL) 566 m->m_pkthdr.rcvif = V_loif; 567 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 568 m->m_pkthdr.csum_flags |= 569 CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR; 570 m->m_pkthdr.csum_data = 0xffff; 571 } 572 #ifdef SCTP 573 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) 574 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 575 #endif 576 error = netisr_queue(NETISR_IPV6, m); 577 goto out; 578 } 579 /* Or forward to some other address? */ 580 if ((m->m_flags & M_IP6_NEXTHOP) && 581 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { 582 dst = (struct sockaddr_in6 *)&rin6.ro_dst; 583 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6)); 584 m->m_flags |= M_SKIP_FIREWALL; 585 m->m_flags &= ~M_IP6_NEXTHOP; 586 m_tag_delete(m, fwd_tag); 587 goto again2; 588 } 589 590 pass: 591 error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); 592 if (error) { 593 in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); 594 IP6STAT_INC(ip6s_cantforward); 595 } else { 596 IP6STAT_INC(ip6s_forward); 597 in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); 598 if (type) 599 IP6STAT_INC(ip6s_redirectsent); 600 else { 601 if (mcopy) 602 goto freecopy; 603 } 604 } 605 606 if (mcopy == NULL) 607 goto out; 608 switch (error) { 609 case 0: 610 if (type == ND_REDIRECT) { 611 icmp6_redirect_output(mcopy, rt); 612 goto out; 613 } 614 goto freecopy; 615 616 case EMSGSIZE: 617 /* xxx MTU is constant in PPP? */ 618 goto freecopy; 619 620 case ENOBUFS: 621 /* Tell source to slow down like source quench in IP? */ 622 goto freecopy; 623 624 case ENETUNREACH: /* shouldn't happen, checked above */ 625 case EHOSTUNREACH: 626 case ENETDOWN: 627 case EHOSTDOWN: 628 default: 629 type = ICMP6_DST_UNREACH; 630 code = ICMP6_DST_UNREACH_ADDR; 631 break; 632 } 633 icmp6_error(mcopy, type, code, 0); 634 goto out; 635 636 freecopy: 637 m_freem(mcopy); 638 goto out; 639 bad: 640 m_freem(m); 641 out: 642 if (rt != NULL) 643 RTFREE(rt); 644 } 645