ip6_forward.c revision 1.69.6.2
1 /* $NetBSD: ip6_forward.c,v 1.69.6.2 2018/04/01 09:20:22 martin Exp $ */ 2 /* $KAME: ip6_forward.c,v 1.109 2002/09/11 08:10:17 sakane 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 <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: ip6_forward.c,v 1.69.6.2 2018/04/01 09:20:22 martin Exp $"); 35 36 #include "opt_gateway.h" 37 #include "opt_ipsec.h" 38 #include "opt_pfil_hooks.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 52 #include <net/if.h> 53 #include <net/route.h> 54 55 #include <netinet/in.h> 56 #include <netinet/in_var.h> 57 #include <netinet/ip_var.h> 58 #include <netinet/ip6.h> 59 #include <netinet6/ip6_var.h> 60 #include <netinet6/ip6_private.h> 61 #include <netinet6/scope6_var.h> 62 #include <netinet/icmp6.h> 63 #include <netinet6/nd6.h> 64 65 #ifdef KAME_IPSEC 66 #include <netinet6/ipsec.h> 67 #include <netinet6/ipsec_private.h> 68 #include <netkey/key.h> 69 #endif /* KAME_IPSEC */ 70 71 #ifdef FAST_IPSEC 72 #include <netipsec/ipsec.h> 73 #include <netipsec/ipsec6.h> 74 #include <netipsec/key.h> 75 #include <netipsec/xform.h> 76 #endif /* FAST_IPSEC */ 77 78 #ifdef PFIL_HOOKS 79 #include <net/pfil.h> 80 #endif 81 82 #include <net/net_osdep.h> 83 84 struct route ip6_forward_rt; 85 86 #ifdef PFIL_HOOKS 87 extern struct pfil_head inet6_pfil_hook; /* XXX */ 88 #endif 89 90 /* 91 * Forward a packet. If some error occurs return the sender 92 * an icmp packet. Note we can't always generate a meaningful 93 * icmp message because icmp doesn't have a large enough repertoire 94 * of codes and types. 95 * 96 * If not forwarding, just drop the packet. This could be confusing 97 * if ipforwarding was zero but some routing protocol was advancing 98 * us as a gateway to somewhere. However, we must let the routing 99 * protocol deal with that. 100 * 101 */ 102 103 void 104 ip6_forward(struct mbuf *m, int srcrt) 105 { 106 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 107 const struct sockaddr_in6 *dst; 108 struct rtentry *rt; 109 int error = 0, type = 0, code = 0; 110 struct mbuf *mcopy = NULL; 111 struct ifnet *origifp; /* maybe unnecessary */ 112 u_int32_t inzone, outzone; 113 struct in6_addr src_in6, dst_in6; 114 #ifdef KAME_IPSEC 115 struct secpolicy *sp = NULL; 116 int ipsecrt = 0; 117 #endif 118 #ifdef FAST_IPSEC 119 struct secpolicy *sp = NULL; 120 int needipsec = 0; 121 int s; 122 #endif 123 124 /* 125 * Clear any in-bound checksum flags for this packet. 126 */ 127 m->m_pkthdr.csum_flags = 0; 128 129 #ifdef KAME_IPSEC 130 /* 131 * Check AH/ESP integrity. 132 */ 133 /* 134 * Don't increment ip6s_cantforward because this is the check 135 * before forwarding packet actually. 136 */ 137 if (ipsec6_in_reject(m, NULL)) { 138 IPSEC6_STATINC(IPSEC_STAT_IN_POLVIO); 139 m_freem(m); 140 return; 141 } 142 #endif /* KAME_IPSEC */ 143 144 /* 145 * Do not forward packets to multicast destination (should be handled 146 * by ip6_mforward(). 147 * Do not forward packets with unspecified source. It was discussed 148 * in July 2000, on ipngwg mailing list. 149 */ 150 if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || 151 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 152 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { 153 IP6_STATINC(IP6_STAT_CANTFORWARD); 154 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 155 if (ip6_log_time + ip6_log_interval < time_second) { 156 ip6_log_time = time_second; 157 log(LOG_DEBUG, 158 "cannot forward " 159 "from %s to %s nxt %d received on %s\n", 160 ip6_sprintf(&ip6->ip6_src), 161 ip6_sprintf(&ip6->ip6_dst), 162 ip6->ip6_nxt, 163 if_name(m->m_pkthdr.rcvif)); 164 } 165 m_freem(m); 166 return; 167 } 168 169 if (ip6->ip6_hlim <= IPV6_HLIMDEC) { 170 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 171 icmp6_error(m, ICMP6_TIME_EXCEEDED, 172 ICMP6_TIME_EXCEED_TRANSIT, 0); 173 return; 174 } 175 ip6->ip6_hlim -= IPV6_HLIMDEC; 176 177 /* 178 * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - 179 * size of IPv6 + ICMPv6 headers) bytes of the packet in case 180 * we need to generate an ICMP6 message to the src. 181 * Thanks to M_EXT, in most cases copy will not occur. 182 * 183 * It is important to save it before IPsec processing as IPsec 184 * processing may modify the mbuf. 185 */ 186 mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); 187 188 #ifdef KAME_IPSEC 189 /* get a security policy for this packet */ 190 sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 191 IP_FORWARDING, &error); 192 if (sp == NULL) { 193 IPSEC6_STATINC(IPSEC_STAT_OUT_INVAL); 194 IP6_STATINC(IP6_STAT_CANTFORWARD); 195 if (mcopy) { 196 #if 0 197 /* XXX: what icmp ? */ 198 #else 199 m_freem(mcopy); 200 #endif 201 } 202 m_freem(m); 203 return; 204 } 205 206 error = 0; 207 208 /* check policy */ 209 switch (sp->policy) { 210 case IPSEC_POLICY_DISCARD: 211 /* 212 * This packet is just discarded. 213 */ 214 IPSEC6_STATINC(IPSEC_STAT_OUT_POLVIO); 215 IP6_STATINC(IP6_STAT_CANTFORWARD); 216 key_freesp(sp); 217 if (mcopy) { 218 #if 0 219 /* XXX: what icmp ? */ 220 #else 221 m_freem(mcopy); 222 #endif 223 } 224 m_freem(m); 225 return; 226 227 case IPSEC_POLICY_BYPASS: 228 case IPSEC_POLICY_NONE: 229 /* no need to do IPsec. */ 230 key_freesp(sp); 231 goto skip_ipsec; 232 233 case IPSEC_POLICY_IPSEC: 234 if (sp->req == NULL) { 235 /* XXX should be panic ? */ 236 printf("ip6_forward: No IPsec request specified.\n"); 237 IP6_STATINC(IP6_STAT_CANTFORWARD); 238 key_freesp(sp); 239 if (mcopy) { 240 #if 0 241 /* XXX: what icmp ? */ 242 #else 243 m_freem(mcopy); 244 #endif 245 } 246 m_freem(m); 247 return; 248 } 249 /* do IPsec */ 250 break; 251 252 case IPSEC_POLICY_ENTRUST: 253 default: 254 /* should be panic ?? */ 255 printf("ip6_forward: Invalid policy found. %d\n", sp->policy); 256 key_freesp(sp); 257 goto skip_ipsec; 258 } 259 260 { 261 struct ipsecrequest *isr = NULL; 262 struct ipsec_output_state state; 263 264 /* 265 * when the kernel forwards a packet, it is not proper to apply 266 * IPsec transport mode to the packet is not proper. this check 267 * avoid from this. 268 * at present, if there is even a transport mode SA request in the 269 * security policy, the kernel does not apply IPsec to the packet. 270 * this check is not enough because the following case is valid. 271 * ipsec esp/tunnel/xxx-xxx/require esp/transport//require; 272 */ 273 for (isr = sp->req; isr; isr = isr->next) { 274 if (isr->saidx.mode == IPSEC_MODE_ANY) 275 goto doipsectunnel; 276 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 277 goto doipsectunnel; 278 } 279 280 /* 281 * if there's no need for tunnel mode IPsec, skip. 282 */ 283 if (!isr) 284 goto skip_ipsec; 285 286 doipsectunnel: 287 /* 288 * All the extension headers will become inaccessible 289 * (since they can be encrypted). 290 * Don't panic, we need no more updates to extension headers 291 * on inner IPv6 packet (since they are now encapsulated). 292 * 293 * IPv6 [ESP|AH] IPv6 [extension headers] payload 294 */ 295 memset(&state, 0, sizeof(state)); 296 state.m = m; 297 state.ro = NULL; /* update at ipsec6_output_tunnel() */ 298 state.dst = NULL; /* update at ipsec6_output_tunnel() */ 299 300 error = ipsec6_output_tunnel(&state, sp, 0); 301 302 m = state.m; 303 key_freesp(sp); 304 305 if (error) { 306 /* mbuf is already reclaimed in ipsec6_output_tunnel. */ 307 switch (error) { 308 case EHOSTUNREACH: 309 case ENETUNREACH: 310 case EMSGSIZE: 311 case ENOBUFS: 312 case ENOMEM: 313 break; 314 default: 315 printf("ip6_forward (ipsec): error code %d\n", error); 316 /* FALLTHROUGH */ 317 case ENOENT: 318 /* don't show these error codes to the user */ 319 break; 320 } 321 IP6_STATINC(IP6_STAT_CANTFORWARD); 322 if (mcopy) { 323 #if 0 324 /* XXX: what icmp ? */ 325 #else 326 m_freem(mcopy); 327 #endif 328 } 329 m_freem(m); 330 return; 331 } 332 333 if (ip6 != mtod(m, struct ip6_hdr *)) { 334 /* 335 * now tunnel mode headers are added. we are originating 336 * packet instead of forwarding the packet. 337 */ 338 ip6_output(m, NULL, NULL, IPV6_FORWARDING/*XXX*/, NULL, NULL, 339 NULL); 340 goto freecopy; 341 } 342 343 /* adjust pointer */ 344 rt = state.ro ? rtcache_validate(state.ro) : NULL; 345 dst = (const struct sockaddr_in6 *)state.dst; 346 if (dst != NULL && rt != NULL) { 347 ipsecrt = 1; 348 goto skip_routing; 349 } 350 } 351 skip_ipsec: 352 #endif /* KAME_IPSEC */ 353 #ifdef FAST_IPSEC 354 /* Check the security policy (SP) for the packet */ 355 356 sp = ipsec6_check_policy(m,NULL,0,&needipsec,&error); 357 if (error != 0) { 358 /* 359 * Hack: -EINVAL is used to signal that a packet 360 * should be silently discarded. This is typically 361 * because we asked key management for an SA and 362 * it was delayed (e.g. kicked up to IKE). 363 */ 364 if (error == -EINVAL) 365 error = 0; 366 m_freem(m); 367 goto freecopy; 368 } 369 #endif /* FAST_IPSEC */ 370 371 if (srcrt) { 372 union { 373 struct sockaddr dst; 374 struct sockaddr_in6 dst6; 375 } u; 376 377 sockaddr_in6_init(&u.dst6, &ip6->ip6_dst, 0, 0, 0); 378 if ((rt = rtcache_lookup(&ip6_forward_rt, &u.dst)) == NULL) { 379 IP6_STATINC(IP6_STAT_NOROUTE); 380 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_noroute) */ 381 if (mcopy) { 382 icmp6_error(mcopy, ICMP6_DST_UNREACH, 383 ICMP6_DST_UNREACH_NOROUTE, 0); 384 } 385 m_freem(m); 386 return; 387 } 388 } else if ((rt = rtcache_validate(&ip6_forward_rt)) == NULL && 389 (rt = rtcache_update(&ip6_forward_rt, 1)) == NULL) { 390 /* 391 * rtcache_getdst(ip6_forward_rt)->sin6_addr was equal to 392 * ip6->ip6_dst 393 */ 394 IP6_STATINC(IP6_STAT_NOROUTE); 395 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_noroute) */ 396 if (mcopy) { 397 icmp6_error(mcopy, ICMP6_DST_UNREACH, 398 ICMP6_DST_UNREACH_NOROUTE, 0); 399 } 400 m_freem(m); 401 return; 402 } 403 dst = satocsin6(rtcache_getdst(&ip6_forward_rt)); 404 #ifdef KAME_IPSEC 405 skip_routing:; 406 #endif /* KAME_IPSEC */ 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-v3-07, 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 uint64_t *ip6s = IP6_STAT_GETREF(); 421 ip6s[IP6_STAT_CANTFORWARD]++; 422 ip6s[IP6_STAT_BADSCOPE]++; 423 IP6_STAT_PUTREF(); 424 m_freem(m); 425 return; 426 } 427 if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { 428 uint64_t *ip6s = IP6_STAT_GETREF(); 429 ip6s[IP6_STAT_CANTFORWARD]++; 430 ip6s[IP6_STAT_BADSCOPE]++; 431 IP6_STAT_PUTREF(); 432 m_freem(m); 433 return; 434 } 435 if (inzone != outzone 436 #ifdef KAME_IPSEC 437 && !ipsecrt 438 #endif 439 ) { 440 uint64_t *ip6s = IP6_STAT_GETREF(); 441 ip6s[IP6_STAT_CANTFORWARD]++; 442 ip6s[IP6_STAT_BADSCOPE]++; 443 IP6_STAT_PUTREF(); 444 in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); 445 446 if (ip6_log_time + ip6_log_interval < time_second) { 447 ip6_log_time = time_second; 448 log(LOG_DEBUG, 449 "cannot forward " 450 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 451 ip6_sprintf(&ip6->ip6_src), 452 ip6_sprintf(&ip6->ip6_dst), 453 ip6->ip6_nxt, 454 if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); 455 } 456 if (mcopy) 457 icmp6_error(mcopy, ICMP6_DST_UNREACH, 458 ICMP6_DST_UNREACH_BEYONDSCOPE, 0); 459 m_freem(m); 460 return; 461 } 462 #ifdef FAST_IPSEC 463 /* 464 * If we need to encapsulate the packet, do it here 465 * ipsec6_proces_packet will send the packet using ip6_output 466 */ 467 if (needipsec) { 468 s = splsoftnet(); 469 error = ipsec6_process_packet(m,sp->req); 470 splx(s); 471 /* m is freed */ 472 if (mcopy) 473 goto freecopy; 474 return; 475 } 476 #endif 477 478 479 480 /* 481 * Destination scope check: if a packet is going to break the scope 482 * zone of packet's destination address, discard it. This case should 483 * usually be prevented by appropriately-configured routing table, but 484 * we need an explicit check because we may mistakenly forward the 485 * packet to a different zone by (e.g.) a default route. 486 */ 487 dst_in6 = ip6->ip6_dst; 488 if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || 489 in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || 490 inzone != outzone) { 491 uint64_t *ip6s = IP6_STAT_GETREF(); 492 ip6s[IP6_STAT_CANTFORWARD]++; 493 ip6s[IP6_STAT_BADSCOPE]++; 494 IP6_STAT_PUTREF(); 495 m_freem(m); 496 return; 497 } 498 499 if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { 500 in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); 501 if (mcopy) { 502 u_long mtu; 503 #ifdef KAME_IPSEC 504 struct secpolicy *xsp; 505 int ipsecerror; 506 size_t ipsechdrsiz; 507 #endif 508 509 mtu = IN6_LINKMTU(rt->rt_ifp); 510 #ifdef KAME_IPSEC 511 /* 512 * When we do IPsec tunnel ingress, we need to play 513 * with the link value (decrement IPsec header size 514 * from mtu value). The code is much simpler than v4 515 * case, as we have the outgoing interface for 516 * encapsulated packet as "rt->rt_ifp". 517 */ 518 xsp = ipsec6_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, 519 IP_FORWARDING, &ipsecerror); 520 if (xsp) { 521 ipsechdrsiz = ipsec6_hdrsiz(mcopy, 522 IPSEC_DIR_OUTBOUND, NULL); 523 if (ipsechdrsiz < mtu) 524 mtu -= ipsechdrsiz; 525 } 526 527 /* 528 * if mtu becomes less than minimum MTU, 529 * tell minimum MTU (and I'll need to fragment it). 530 */ 531 if (mtu < IPV6_MMTU) 532 mtu = IPV6_MMTU; 533 #endif 534 icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); 535 } 536 m_freem(m); 537 return; 538 } 539 540 if (rt->rt_flags & RTF_GATEWAY) 541 dst = (struct sockaddr_in6 *)rt->rt_gateway; 542 543 /* 544 * If we are to forward the packet using the same interface 545 * as one we got the packet from, perhaps we should send a redirect 546 * to sender to shortcut a hop. 547 * Only send redirect if source is sending directly to us, 548 * and if packet was not source routed (or has any options). 549 * Also, don't send redirect if forwarding using a route 550 * modified by a redirect. 551 */ 552 if (rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && ip6_sendredirects && 553 #ifdef KAME_IPSEC 554 !ipsecrt && 555 #endif 556 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { 557 if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) && 558 nd6_is_addr_neighbor( 559 satocsin6(rtcache_getdst(&ip6_forward_rt)), 560 rt->rt_ifp)) { 561 /* 562 * If the incoming interface is equal to the outgoing 563 * one, the link attached to the interface is 564 * point-to-point, and the IPv6 destination is 565 * regarded as on-link on the link, then it will be 566 * highly probable that the destination address does 567 * not exist on the link and that the packet is going 568 * to loop. Thus, we immediately drop the packet and 569 * send an ICMPv6 error message. 570 * For other routing loops, we dare to let the packet 571 * go to the loop, so that a remote diagnosing host 572 * can detect the loop by traceroute. 573 * type/code is based on suggestion by Rich Draves. 574 * not sure if it is the best pick. 575 */ 576 icmp6_error(mcopy, ICMP6_DST_UNREACH, 577 ICMP6_DST_UNREACH_ADDR, 0); 578 m_freem(m); 579 return; 580 } 581 type = ND_REDIRECT; 582 } 583 584 /* 585 * Fake scoped addresses. Note that even link-local source or 586 * destinaion can appear, if the originating node just sends the 587 * packet to us (without address resolution for the destination). 588 * Since both icmp6_error and icmp6_redirect_output fill the embedded 589 * link identifiers, we can do this stuff after making a copy for 590 * returning an error. 591 */ 592 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { 593 /* 594 * See corresponding comments in ip6_output. 595 * XXX: but is it possible that ip6_forward() sends a packet 596 * to a loopback interface? I don't think so, and thus 597 * I bark here. (jinmei (at) kame.net) 598 * XXX: it is common to route invalid packets to loopback. 599 * also, the codepath will be visited on use of ::1 in 600 * rthdr. (itojun) 601 */ 602 #if 1 603 if (0) 604 #else 605 if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) 606 #endif 607 { 608 printf("ip6_forward: outgoing interface is loopback. " 609 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 610 ip6_sprintf(&ip6->ip6_src), 611 ip6_sprintf(&ip6->ip6_dst), 612 ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), 613 if_name(rt->rt_ifp)); 614 } 615 616 /* we can just use rcvif in forwarding. */ 617 origifp = m->m_pkthdr.rcvif; 618 } 619 else 620 origifp = rt->rt_ifp; 621 /* 622 * clear embedded scope identifiers if necessary. 623 * in6_clearscope will touch the addresses only when necessary. 624 */ 625 in6_clearscope(&ip6->ip6_src); 626 in6_clearscope(&ip6->ip6_dst); 627 628 #ifdef PFIL_HOOKS 629 /* 630 * Run through list of hooks for output packets. 631 */ 632 if ((error = pfil_run_hooks(&inet6_pfil_hook, &m, rt->rt_ifp, 633 PFIL_OUT)) != 0) 634 goto senderr; 635 if (m == NULL) 636 goto freecopy; 637 ip6 = mtod(m, struct ip6_hdr *); 638 #endif /* PFIL_HOOKS */ 639 640 error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); 641 if (error) { 642 in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); 643 IP6_STATINC(IP6_STAT_CANTFORWARD); 644 } else { 645 IP6_STATINC(IP6_STAT_FORWARD); 646 in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); 647 if (type) 648 IP6_STATINC(IP6_STAT_REDIRECTSENT); 649 else { 650 #ifdef GATEWAY 651 if (mcopy->m_flags & M_CANFASTFWD) 652 ip6flow_create(&ip6_forward_rt, mcopy); 653 #endif 654 if (mcopy) 655 goto freecopy; 656 } 657 } 658 659 #ifdef PFIL_HOOKS 660 senderr: 661 #endif 662 if (mcopy == NULL) 663 return; 664 switch (error) { 665 case 0: 666 if (type == ND_REDIRECT) { 667 icmp6_redirect_output(mcopy, rt); 668 return; 669 } 670 goto freecopy; 671 672 case EMSGSIZE: 673 /* xxx MTU is constant in PPP? */ 674 goto freecopy; 675 676 case ENOBUFS: 677 /* Tell source to slow down like source quench in IP? */ 678 goto freecopy; 679 680 case ENETUNREACH: /* shouldn't happen, checked above */ 681 case EHOSTUNREACH: 682 case ENETDOWN: 683 case EHOSTDOWN: 684 default: 685 type = ICMP6_DST_UNREACH; 686 code = ICMP6_DST_UNREACH_ADDR; 687 break; 688 } 689 icmp6_error(mcopy, type, code, 0); 690 return; 691 692 freecopy: 693 m_freem(mcopy); 694 return; 695 } 696
Indexes created Sun Oct 19 02:09:48 GMT 2025