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