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/netisr.h> 55 #include <net/route.h> 56 #include <net/pfil.h> 57 58 #include <netinet/in.h> 59 #include <netinet/in_var.h> 60 #include <netinet/in_systm.h> 61 #include <netinet/ip.h> 62 #include <netinet/ip_var.h> 63 #include <netinet6/in6_var.h> 64 #include <netinet/ip6.h> 65 #include <netinet6/ip6_var.h> 66 #include <netinet6/scope6_var.h> 67 #include <netinet/icmp6.h> 68 #include <netinet6/nd6.h> 69 70 #include <netinet/in_pcb.h> 71 72 #ifdef IPSEC 73 #include <netipsec/ipsec.h> 74 #include <netipsec/ipsec6.h> 75 #include <netipsec/key.h> 76 #endif /* IPSEC */ 77 78 #include <netinet6/ip6protosw.h> 79 80 /* 81 * Forward a packet. If some error occurs return the sender 82 * an icmp packet. Note we can't always generate a meaningful 83 * icmp message because icmp doesn't have a large enough repertoire 84 * of codes and types. 85 * 86 * If not forwarding, just drop the packet. This could be confusing 87 * if ipforwarding was zero but some routing protocol was advancing 88 * us as a gateway to somewhere. However, we must let the routing 89 * protocol deal with that. 90 * 91 */ 92 void 93 ip6_forward(struct mbuf *m, int srcrt) 94 { 95 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 96 struct sockaddr_in6 *dst = NULL; 97 struct rtentry *rt = NULL; 98 struct route_in6 rin6; 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, odst; 104 #ifdef IPSEC 105 struct secpolicy *sp = NULL; 106 int ipsecrt = 0; 107 #endif 108 #ifdef SCTP 109 int sw_csum; 110 #endif 111 #ifdef IPFIREWALL_FORWARD 112 struct m_tag *fwd_tag; 113 #endif 114 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 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 if (ipsecrt) 353 goto skip_routing; 354 skip_ipsec: 355 #endif 356 again: 357 bzero(&rin6, sizeof(struct route_in6)); 358 dst = (struct sockaddr_in6 *)&rin6.ro_dst; 359 dst->sin6_len = sizeof(struct sockaddr_in6); 360 dst->sin6_family = AF_INET6; 361 dst->sin6_addr = ip6->ip6_dst; 362 #ifdef IPFIREWALL_FORWARD 363 again2: 364 #endif 365 rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m)); 366 if (rin6.ro_rt != NULL) 367 RT_UNLOCK(rin6.ro_rt); 368 else { 369 V_ip6stat.ip6s_noroute++; 370 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 371 if (mcopy) { 372 icmp6_error(mcopy, ICMP6_DST_UNREACH, 373 ICMP6_DST_UNREACH_NOROUTE, 0); 374 } 375 goto bad; 376 } 377 rt = rin6.ro_rt; 378 #ifdef IPSEC 379 skip_routing: 380 #endif 381 382 /* 383 * Source scope check: if a packet can't be delivered to its 384 * destination for the reason that the destination is beyond the scope 385 * of the source address, discard the packet and return an icmp6 386 * destination unreachable error with Code 2 (beyond scope of source 387 * address). We use a local copy of ip6_src, since in6_setscope() 388 * will possibly modify its first argument. 389 * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1] 390 */ 391 src_in6 = ip6->ip6_src; 392 if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) { 393 /* XXX: this should not happen */ 394 V_ip6stat.ip6s_cantforward++; 395 V_ip6stat.ip6s_badscope++; 396 goto bad; 397 } 398 if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { 399 V_ip6stat.ip6s_cantforward++; 400 V_ip6stat.ip6s_badscope++; 401 goto bad; 402 } 403 if (inzone != outzone 404 #ifdef IPSEC 405 && !ipsecrt 406 #endif 407 ) { 408 V_ip6stat.ip6s_cantforward++; 409 V_ip6stat.ip6s_badscope++; 410 in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); 411 412 if (V_ip6_log_time + V_ip6_log_interval < time_second) { 413 V_ip6_log_time = time_second; 414 log(LOG_DEBUG, 415 "cannot forward " 416 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 417 ip6_sprintf(ip6bufs, &ip6->ip6_src), 418 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 419 ip6->ip6_nxt, 420 if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); 421 } 422 if (mcopy) 423 icmp6_error(mcopy, ICMP6_DST_UNREACH, 424 ICMP6_DST_UNREACH_BEYONDSCOPE, 0); 425 goto bad; 426 } 427 428 /* 429 * Destination scope check: if a packet is going to break the scope 430 * zone of packet's destination address, discard it. This case should 431 * usually be prevented by appropriately-configured routing table, but 432 * we need an explicit check because we may mistakenly forward the 433 * packet to a different zone by (e.g.) a default route. 434 */ 435 dst_in6 = ip6->ip6_dst; 436 if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || 437 in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || 438 inzone != outzone) { 439 V_ip6stat.ip6s_cantforward++; 440 V_ip6stat.ip6s_badscope++; 441 goto bad; 442 } 443 444 if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { 445 in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); 446 if (mcopy) { 447 u_long mtu; 448 #ifdef IPSEC 449 struct secpolicy *sp; 450 int ipsecerror; 451 size_t ipsechdrsiz; 452 #endif /* IPSEC */ 453 454 mtu = IN6_LINKMTU(rt->rt_ifp); 455 #ifdef IPSEC 456 /* 457 * When we do IPsec tunnel ingress, we need to play 458 * with the link value (decrement IPsec header size 459 * from mtu value). The code is much simpler than v4 460 * case, as we have the outgoing interface for 461 * encapsulated packet as "rt->rt_ifp". 462 */ 463 sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, 464 IP_FORWARDING, &ipsecerror); 465 if (sp) { 466 ipsechdrsiz = ipsec_hdrsiz(mcopy, 467 IPSEC_DIR_OUTBOUND, NULL); 468 if (ipsechdrsiz < mtu) 469 mtu -= ipsechdrsiz; 470 } 471 472 /* 473 * if mtu becomes less than minimum MTU, 474 * tell minimum MTU (and I'll need to fragment it). 475 */ 476 if (mtu < IPV6_MMTU) 477 mtu = IPV6_MMTU; 478 #endif /* IPSEC */ 479 icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); 480 } 481 goto bad; 482 } 483 484 if (rt->rt_flags & RTF_GATEWAY) 485 dst = (struct sockaddr_in6 *)rt->rt_gateway; 486 487 /* 488 * If we are to forward the packet using the same interface 489 * as one we got the packet from, perhaps we should send a redirect 490 * to sender to shortcut a hop. 491 * Only send redirect if source is sending directly to us, 492 * and if packet was not source routed (or has any options). 493 * Also, don't send redirect if forwarding using a route 494 * modified by a redirect. 495 */ 496 if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && 497 #ifdef IPSEC 498 !ipsecrt && 499 #endif /* IPSEC */ 500 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { 501 if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { 502 /* 503 * If the incoming interface is equal to the outgoing 504 * one, and the link attached to the interface is 505 * point-to-point, then it will be highly probable 506 * that a routing loop occurs. Thus, we immediately 507 * drop the packet and send an ICMPv6 error message. 508 * 509 * type/code is based on suggestion by Rich Draves. 510 * not sure if it is the best pick. 511 */ 512 icmp6_error(mcopy, ICMP6_DST_UNREACH, 513 ICMP6_DST_UNREACH_ADDR, 0); 514 goto bad; 515 } 516 type = ND_REDIRECT; 517 } 518 519 /* 520 * Fake scoped addresses. Note that even link-local source or 521 * destinaion can appear, if the originating node just sends the 522 * packet to us (without address resolution for the destination). 523 * Since both icmp6_error and icmp6_redirect_output fill the embedded 524 * link identifiers, we can do this stuff after making a copy for 525 * returning an error. 526 */ 527 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { 528 /* 529 * See corresponding comments in ip6_output. 530 * XXX: but is it possible that ip6_forward() sends a packet 531 * to a loopback interface? I don't think so, and thus 532 * I bark here. (jinmei@kame.net) 533 * XXX: it is common to route invalid packets to loopback. 534 * also, the codepath will be visited on use of ::1 in 535 * rthdr. (itojun) 536 */ 537 #if 1 538 if (0) 539 #else 540 if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) 541 #endif 542 { 543 printf("ip6_forward: outgoing interface is loopback. " 544 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 545 ip6_sprintf(ip6bufs, &ip6->ip6_src), 546 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 547 ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), 548 if_name(rt->rt_ifp)); 549 } 550 551 /* we can just use rcvif in forwarding. */ 552 origifp = m->m_pkthdr.rcvif; 553 } 554 else 555 origifp = rt->rt_ifp; 556 /* 557 * clear embedded scope identifiers if necessary. 558 * in6_clearscope will touch the addresses only when necessary. 559 */ 560 in6_clearscope(&ip6->ip6_src); 561 in6_clearscope(&ip6->ip6_dst); 562 563 /* Jump over all PFIL processing if hooks are not active. */ 564 if (!PFIL_HOOKED(&V_inet6_pfil_hook)) 565 goto pass; 566 567 odst = ip6->ip6_dst; 568 /* Run through list of hooks for output packets. */ 569 error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL); 570 if (error != 0) 571 goto senderr; 572 if (m == NULL) 573 goto freecopy; 574 ip6 = mtod(m, struct ip6_hdr *); 575 576 /* See if destination IP address was changed by packet filter. */ 577 if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) { 578 m->m_flags |= M_SKIP_FIREWALL; 579 /* If destination is now ourself drop to ip6_input(). */ 580 if (in6_localip(&ip6->ip6_dst)) { 581 m->m_flags |= M_FASTFWD_OURS; 582 if (m->m_pkthdr.rcvif == NULL) 583 m->m_pkthdr.rcvif = V_loif; 584 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 585 m->m_pkthdr.csum_flags |= 586 CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR; 587 m->m_pkthdr.csum_data = 0xffff; 588 } 589 #ifdef SCTP 590 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) 591 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 592 #endif 593 error = netisr_queue(NETISR_IPV6, m); 594 goto out; 595 } else 596 goto again; /* Redo the routing table lookup. */ 597 } 598 599 #ifdef IPFIREWALL_FORWARD 600 /* See if local, if yes, send it to netisr. */ 601 if (m->m_flags & M_FASTFWD_OURS) { 602 if (m->m_pkthdr.rcvif == NULL) 603 m->m_pkthdr.rcvif = V_loif; 604 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 605 m->m_pkthdr.csum_flags |= 606 CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR; 607 m->m_pkthdr.csum_data = 0xffff; 608 } 609 #ifdef SCTP 610 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) 611 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 612 #endif 613 error = netisr_queue(NETISR_IPV6, m); 614 goto out; 615 } 616 /* Or forward to some other address? */ 617 fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 618 if (fwd_tag) { 619 dst = (struct sockaddr_in6 *)&rin6.ro_dst; 620 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6)); 621 m->m_flags |= M_SKIP_FIREWALL; 622 m_tag_delete(m, fwd_tag); 623 goto again2; 624 } 625 #endif /* IPFIREWALL_FORWARD */ 626 627 pass: 628 error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); 629 if (error) { 630 in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); 631 V_ip6stat.ip6s_cantforward++; 632 } else { 633 V_ip6stat.ip6s_forward++; 634 in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); 635 if (type) 636 V_ip6stat.ip6s_redirectsent++; 637 else { 638 if (mcopy) 639 goto freecopy; 640 } 641 } 642 643 senderr: 644 if (mcopy == NULL) 645 goto out; 646 switch (error) { 647 case 0: 648 if (type == ND_REDIRECT) { 649 icmp6_redirect_output(mcopy, rt); 650 goto out; 651 } 652 goto freecopy; 653 654 case EMSGSIZE: 655 /* xxx MTU is constant in PPP? */ 656 goto freecopy; 657 658 case ENOBUFS: 659 /* Tell source to slow down like source quench in IP? */ 660 goto freecopy; 661 662 case ENETUNREACH: /* shouldn't happen, checked above */ 663 case EHOSTUNREACH: 664 case ENETDOWN: 665 case EHOSTDOWN: 666 default: 667 type = ICMP6_DST_UNREACH; 668 code = ICMP6_DST_UNREACH_ADDR; 669 break; 670 } 671 icmp6_error(mcopy, type, code, 0); 672 goto out; 673 674 freecopy: 675 m_freem(mcopy); 676 goto out; 677 bad: 678 m_freem(m); 679 out: 680 if (rt != NULL 681 #ifdef IPSEC 682 && !ipsecrt 683 #endif 684 ) 685 RTFREE(rt); 686 } 687