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 #include <netinet6/ip6protosw.h> 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 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 97 struct sockaddr_in6 *dst = NULL; 98 struct rtentry *rt = NULL; 99 struct route_in6 rin6; 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, odst; 105 #ifdef IPSEC 106 struct secpolicy *sp = NULL; 107 int ipsecrt = 0; 108 #endif 109 #ifdef SCTP 110 int sw_csum; 111 #endif 112 struct m_tag *fwd_tag; 113 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 114 115 #ifdef IPSEC 116 /* 117 * Check AH/ESP integrity. 118 */ 119 /* 120 * Don't increment ip6s_cantforward because this is the check 121 * before forwarding packet actually. 122 */ 123 if (ipsec6_in_reject(m, NULL)) { 124 IPSEC6STAT_INC(ips_in_polvio); 125 m_freem(m); 126 return; 127 } 128 #endif /* IPSEC */ 129 130 /* 131 * Do not forward packets to multicast destination (should be handled 132 * by ip6_mforward(). 133 * Do not forward packets with unspecified source. It was discussed 134 * in July 2000, on the ipngwg mailing list. 135 */ 136 if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || 137 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 138 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { 139 IP6STAT_INC(ip6s_cantforward); 140 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 141 if (V_ip6_log_time + V_ip6_log_interval < time_uptime) { 142 V_ip6_log_time = time_uptime; 143 log(LOG_DEBUG, 144 "cannot forward " 145 "from %s to %s nxt %d received on %s\n", 146 ip6_sprintf(ip6bufs, &ip6->ip6_src), 147 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 148 ip6->ip6_nxt, 149 if_name(m->m_pkthdr.rcvif)); 150 } 151 m_freem(m); 152 return; 153 } 154 155 #ifdef IPSTEALTH 156 if (!V_ip6stealth) { 157 #endif 158 if (ip6->ip6_hlim <= IPV6_HLIMDEC) { 159 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 160 icmp6_error(m, ICMP6_TIME_EXCEEDED, 161 ICMP6_TIME_EXCEED_TRANSIT, 0); 162 return; 163 } 164 ip6->ip6_hlim -= IPV6_HLIMDEC; 165 166 #ifdef IPSTEALTH 167 } 168 #endif 169 170 /* 171 * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - 172 * size of IPv6 + ICMPv6 headers) bytes of the packet in case 173 * we need to generate an ICMP6 message to the src. 174 * Thanks to M_EXT, in most cases copy will not occur. 175 * 176 * It is important to save it before IPsec processing as IPsec 177 * processing may modify the mbuf. 178 */ 179 mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); 180 181 #ifdef IPSEC 182 /* get a security policy for this packet */ 183 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 184 IP_FORWARDING, &error); 185 if (sp == NULL) { 186 IPSEC6STAT_INC(ips_out_inval); 187 IP6STAT_INC(ip6s_cantforward); 188 if (mcopy) { 189 #if 0 190 /* XXX: what icmp ? */ 191 #else 192 m_freem(mcopy); 193 #endif 194 } 195 m_freem(m); 196 return; 197 } 198 199 error = 0; 200 201 /* check policy */ 202 switch (sp->policy) { 203 case IPSEC_POLICY_DISCARD: 204 /* 205 * This packet is just discarded. 206 */ 207 IPSEC6STAT_INC(ips_out_polvio); 208 IP6STAT_INC(ip6s_cantforward); 209 KEY_FREESP(&sp); 210 if (mcopy) { 211 #if 0 212 /* XXX: what icmp ? */ 213 #else 214 m_freem(mcopy); 215 #endif 216 } 217 m_freem(m); 218 return; 219 220 case IPSEC_POLICY_BYPASS: 221 case IPSEC_POLICY_NONE: 222 /* no need to do IPsec. */ 223 KEY_FREESP(&sp); 224 goto skip_ipsec; 225 226 case IPSEC_POLICY_IPSEC: 227 if (sp->req == NULL) { 228 /* XXX should be panic ? */ 229 printf("ip6_forward: No IPsec request specified.\n"); 230 IP6STAT_INC(ip6s_cantforward); 231 KEY_FREESP(&sp); 232 if (mcopy) { 233 #if 0 234 /* XXX: what icmp ? */ 235 #else 236 m_freem(mcopy); 237 #endif 238 } 239 m_freem(m); 240 return; 241 } 242 /* do IPsec */ 243 break; 244 245 case IPSEC_POLICY_ENTRUST: 246 default: 247 /* should be panic ?? */ 248 printf("ip6_forward: Invalid policy found. %d\n", sp->policy); 249 KEY_FREESP(&sp); 250 goto skip_ipsec; 251 } 252 253 { 254 struct ipsecrequest *isr = NULL; 255 struct ipsec_output_state state; 256 257 /* 258 * when the kernel forwards a packet, it is not proper to apply 259 * IPsec transport mode to the packet is not proper. this check 260 * avoid from this. 261 * at present, if there is even a transport mode SA request in the 262 * security policy, the kernel does not apply IPsec to the packet. 263 * this check is not enough because the following case is valid. 264 * ipsec esp/tunnel/xxx-xxx/require esp/transport//require; 265 */ 266 for (isr = sp->req; isr; isr = isr->next) { 267 if (isr->saidx.mode == IPSEC_MODE_ANY) 268 goto doipsectunnel; 269 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 270 goto doipsectunnel; 271 } 272 273 /* 274 * if there's no need for tunnel mode IPsec, skip. 275 */ 276 if (!isr) 277 goto skip_ipsec; 278 279 doipsectunnel: 280 /* 281 * All the extension headers will become inaccessible 282 * (since they can be encrypted). 283 * Don't panic, we need no more updates to extension headers 284 * on inner IPv6 packet (since they are now encapsulated). 285 * 286 * IPv6 [ESP|AH] IPv6 [extension headers] payload 287 */ 288 bzero(&state, sizeof(state)); 289 state.m = m; 290 state.ro = NULL; /* update at ipsec6_output_tunnel() */ 291 state.dst = NULL; /* update at ipsec6_output_tunnel() */ 292 293 error = ipsec6_output_tunnel(&state, sp, 0); 294 295 m = state.m; 296 KEY_FREESP(&sp); 297 298 if (error) { 299 /* mbuf is already reclaimed in ipsec6_output_tunnel. */ 300 switch (error) { 301 case EHOSTUNREACH: 302 case ENETUNREACH: 303 case EMSGSIZE: 304 case ENOBUFS: 305 case ENOMEM: 306 break; 307 default: 308 printf("ip6_output (ipsec): error code %d\n", error); 309 /* FALLTHROUGH */ 310 case ENOENT: 311 /* don't show these error codes to the user */ 312 break; 313 } 314 IP6STAT_INC(ip6s_cantforward); 315 if (mcopy) { 316 #if 0 317 /* XXX: what icmp ? */ 318 #else 319 m_freem(mcopy); 320 #endif 321 } 322 m_freem(m); 323 return; 324 } else { 325 /* 326 * In the FAST IPSec case we have already 327 * re-injected the packet and it has been freed 328 * by the ipsec_done() function. So, just clean 329 * up after ourselves. 330 */ 331 m = NULL; 332 goto freecopy; 333 } 334 335 if ((m != NULL) && (ip6 != mtod(m, struct ip6_hdr *)) ){ 336 /* 337 * now tunnel mode headers are added. we are originating 338 * packet instead of forwarding the packet. 339 */ 340 ip6_output(m, NULL, NULL, IPV6_FORWARDING/*XXX*/, NULL, NULL, 341 NULL); 342 goto freecopy; 343 } 344 345 /* adjust pointer */ 346 dst = (struct sockaddr_in6 *)state.dst; 347 rt = state.ro ? state.ro->ro_rt : NULL; 348 if (dst != NULL && rt != NULL) 349 ipsecrt = 1; 350 } 351 if (ipsecrt) 352 goto skip_routing; 353 skip_ipsec: 354 #endif 355 again: 356 bzero(&rin6, sizeof(struct route_in6)); 357 dst = (struct sockaddr_in6 *)&rin6.ro_dst; 358 dst->sin6_len = sizeof(struct sockaddr_in6); 359 dst->sin6_family = AF_INET6; 360 dst->sin6_addr = ip6->ip6_dst; 361 again2: 362 rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m)); 363 if (rin6.ro_rt != NULL) 364 RT_UNLOCK(rin6.ro_rt); 365 else { 366 IP6STAT_INC(ip6s_noroute); 367 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 368 if (mcopy) { 369 icmp6_error(mcopy, ICMP6_DST_UNREACH, 370 ICMP6_DST_UNREACH_NOROUTE, 0); 371 } 372 goto bad; 373 } 374 rt = rin6.ro_rt; 375 #ifdef IPSEC 376 skip_routing: 377 #endif 378 379 /* 380 * Source scope check: if a packet can't be delivered to its 381 * destination for the reason that the destination is beyond the scope 382 * of the source address, discard the packet and return an icmp6 383 * destination unreachable error with Code 2 (beyond scope of source 384 * address). We use a local copy of ip6_src, since in6_setscope() 385 * will possibly modify its first argument. 386 * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1] 387 */ 388 src_in6 = ip6->ip6_src; 389 if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) { 390 /* XXX: this should not happen */ 391 IP6STAT_INC(ip6s_cantforward); 392 IP6STAT_INC(ip6s_badscope); 393 goto bad; 394 } 395 if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { 396 IP6STAT_INC(ip6s_cantforward); 397 IP6STAT_INC(ip6s_badscope); 398 goto bad; 399 } 400 if (inzone != outzone 401 #ifdef IPSEC 402 && !ipsecrt 403 #endif 404 ) { 405 IP6STAT_INC(ip6s_cantforward); 406 IP6STAT_INC(ip6s_badscope); 407 in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); 408 409 if (V_ip6_log_time + V_ip6_log_interval < time_uptime) { 410 V_ip6_log_time = time_uptime; 411 log(LOG_DEBUG, 412 "cannot forward " 413 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 414 ip6_sprintf(ip6bufs, &ip6->ip6_src), 415 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 416 ip6->ip6_nxt, 417 if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); 418 } 419 if (mcopy) 420 icmp6_error(mcopy, ICMP6_DST_UNREACH, 421 ICMP6_DST_UNREACH_BEYONDSCOPE, 0); 422 goto bad; 423 } 424 425 /* 426 * Destination scope check: if a packet is going to break the scope 427 * zone of packet's destination address, discard it. This case should 428 * usually be prevented by appropriately-configured routing table, but 429 * we need an explicit check because we may mistakenly forward the 430 * packet to a different zone by (e.g.) a default route. 431 */ 432 dst_in6 = ip6->ip6_dst; 433 if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || 434 in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || 435 inzone != outzone) { 436 IP6STAT_INC(ip6s_cantforward); 437 IP6STAT_INC(ip6s_badscope); 438 goto bad; 439 } 440 441 if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { 442 in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); 443 if (mcopy) { 444 u_long mtu; 445 #ifdef IPSEC 446 struct secpolicy *sp; 447 int ipsecerror; 448 size_t ipsechdrsiz; 449 #endif /* IPSEC */ 450 451 mtu = IN6_LINKMTU(rt->rt_ifp); 452 #ifdef IPSEC 453 /* 454 * When we do IPsec tunnel ingress, we need to play 455 * with the link value (decrement IPsec header size 456 * from mtu value). The code is much simpler than v4 457 * case, as we have the outgoing interface for 458 * encapsulated packet as "rt->rt_ifp". 459 */ 460 sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, 461 IP_FORWARDING, &ipsecerror); 462 if (sp) { 463 ipsechdrsiz = ipsec_hdrsiz(mcopy, 464 IPSEC_DIR_OUTBOUND, NULL); 465 if (ipsechdrsiz < mtu) 466 mtu -= ipsechdrsiz; 467 } 468 469 /* 470 * if mtu becomes less than minimum MTU, 471 * tell minimum MTU (and I'll need to fragment it). 472 */ 473 if (mtu < IPV6_MMTU) 474 mtu = IPV6_MMTU; 475 #endif /* IPSEC */ 476 icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); 477 } 478 goto bad; 479 } 480 481 if (rt->rt_flags & RTF_GATEWAY) 482 dst = (struct sockaddr_in6 *)rt->rt_gateway; 483 484 /* 485 * If we are to forward the packet using the same interface 486 * as one we got the packet from, perhaps we should send a redirect 487 * to sender to shortcut a hop. 488 * Only send redirect if source is sending directly to us, 489 * and if packet was not source routed (or has any options). 490 * Also, don't send redirect if forwarding using a route 491 * modified by a redirect. 492 */ 493 if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && 494 #ifdef IPSEC 495 !ipsecrt && 496 #endif /* IPSEC */ 497 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { 498 if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { 499 /* 500 * If the incoming interface is equal to the outgoing 501 * one, and the link attached to the interface is 502 * point-to-point, then it will be highly probable 503 * that a routing loop occurs. Thus, we immediately 504 * drop the packet and send an ICMPv6 error message. 505 * 506 * type/code is based on suggestion by Rich Draves. 507 * not sure if it is the best pick. 508 */ 509 icmp6_error(mcopy, ICMP6_DST_UNREACH, 510 ICMP6_DST_UNREACH_ADDR, 0); 511 goto bad; 512 } 513 type = ND_REDIRECT; 514 } 515 516 /* 517 * Fake scoped addresses. Note that even link-local source or 518 * destinaion can appear, if the originating node just sends the 519 * packet to us (without address resolution for the destination). 520 * Since both icmp6_error and icmp6_redirect_output fill the embedded 521 * link identifiers, we can do this stuff after making a copy for 522 * returning an error. 523 */ 524 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { 525 /* 526 * See corresponding comments in ip6_output. 527 * XXX: but is it possible that ip6_forward() sends a packet 528 * to a loopback interface? I don't think so, and thus 529 * I bark here. (jinmei@kame.net) 530 * XXX: it is common to route invalid packets to loopback. 531 * also, the codepath will be visited on use of ::1 in 532 * rthdr. (itojun) 533 */ 534 #if 1 535 if (0) 536 #else 537 if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) 538 #endif 539 { 540 printf("ip6_forward: outgoing interface is loopback. " 541 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 542 ip6_sprintf(ip6bufs, &ip6->ip6_src), 543 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 544 ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), 545 if_name(rt->rt_ifp)); 546 } 547 548 /* we can just use rcvif in forwarding. */ 549 origifp = m->m_pkthdr.rcvif; 550 } 551 else 552 origifp = rt->rt_ifp; 553 /* 554 * clear embedded scope identifiers if necessary. 555 * in6_clearscope will touch the addresses only when necessary. 556 */ 557 in6_clearscope(&ip6->ip6_src); 558 in6_clearscope(&ip6->ip6_dst); 559 560 /* Jump over all PFIL processing if hooks are not active. */ 561 if (!PFIL_HOOKED(&V_inet6_pfil_hook)) 562 goto pass; 563 564 odst = ip6->ip6_dst; 565 /* Run through list of hooks for output packets. */ 566 error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL); 567 if (error != 0) 568 goto senderr; 569 if (m == NULL) 570 goto freecopy; 571 ip6 = mtod(m, struct ip6_hdr *); 572 573 /* See if destination IP address was changed by packet filter. */ 574 if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) { 575 m->m_flags |= M_SKIP_FIREWALL; 576 /* If destination is now ourself drop to ip6_input(). */ 577 if (in6_localip(&ip6->ip6_dst)) { 578 m->m_flags |= M_FASTFWD_OURS; 579 if (m->m_pkthdr.rcvif == NULL) 580 m->m_pkthdr.rcvif = V_loif; 581 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 582 m->m_pkthdr.csum_flags |= 583 CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR; 584 m->m_pkthdr.csum_data = 0xffff; 585 } 586 #ifdef SCTP 587 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) 588 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 589 #endif 590 error = netisr_queue(NETISR_IPV6, m); 591 goto out; 592 } else 593 goto again; /* Redo the routing table lookup. */ 594 } 595 596 /* See if local, if yes, send it to netisr. */ 597 if (m->m_flags & M_FASTFWD_OURS) { 598 if (m->m_pkthdr.rcvif == NULL) 599 m->m_pkthdr.rcvif = V_loif; 600 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 601 m->m_pkthdr.csum_flags |= 602 CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR; 603 m->m_pkthdr.csum_data = 0xffff; 604 } 605 #ifdef SCTP 606 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) 607 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 608 #endif 609 error = netisr_queue(NETISR_IPV6, m); 610 goto out; 611 } 612 /* Or forward to some other address? */ 613 if ((m->m_flags & M_IP6_NEXTHOP) && 614 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { 615 dst = (struct sockaddr_in6 *)&rin6.ro_dst; 616 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6)); 617 m->m_flags |= M_SKIP_FIREWALL; 618 m->m_flags &= ~M_IP6_NEXTHOP; 619 m_tag_delete(m, fwd_tag); 620 goto again2; 621 } 622 623 pass: 624 error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); 625 if (error) { 626 in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); 627 IP6STAT_INC(ip6s_cantforward); 628 } else { 629 IP6STAT_INC(ip6s_forward); 630 in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); 631 if (type) 632 IP6STAT_INC(ip6s_redirectsent); 633 else { 634 if (mcopy) 635 goto freecopy; 636 } 637 } 638 639 senderr: 640 if (mcopy == NULL) 641 goto out; 642 switch (error) { 643 case 0: 644 if (type == ND_REDIRECT) { 645 icmp6_redirect_output(mcopy, rt); 646 goto out; 647 } 648 goto freecopy; 649 650 case EMSGSIZE: 651 /* xxx MTU is constant in PPP? */ 652 goto freecopy; 653 654 case ENOBUFS: 655 /* Tell source to slow down like source quench in IP? */ 656 goto freecopy; 657 658 case ENETUNREACH: /* shouldn't happen, checked above */ 659 case EHOSTUNREACH: 660 case ENETDOWN: 661 case EHOSTDOWN: 662 default: 663 type = ICMP6_DST_UNREACH; 664 code = ICMP6_DST_UNREACH_ADDR; 665 break; 666 } 667 icmp6_error(mcopy, type, code, 0); 668 goto out; 669 670 freecopy: 671 m_freem(mcopy); 672 goto out; 673 bad: 674 m_freem(m); 675 out: 676 if (rt != NULL 677 #ifdef IPSEC 678 && !ipsecrt 679 #endif 680 ) 681 RTFREE(rt); 682 } 683