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: releng/10.1/sys/netinet6/ip6_forward.c 264224 2014-04-07 12:58:54Z ae $");
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 struct m_tag *fwd_tag;
112 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
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 IPSEC6STAT_INC(ips_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 IP6STAT_INC(ip6s_cantforward);
139 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
140 if (V_ip6_log_time + V_ip6_log_interval < time_uptime) {
141 V_ip6_log_time = time_uptime;
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 IPSEC6STAT_INC(ips_out_inval);
186 IP6STAT_INC(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 IPSEC6STAT_INC(ips_out_polvio);
207 IP6STAT_INC(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 IP6STAT_INC(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 IP6STAT_INC(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 if (ipsecrt)
351 goto skip_routing;
352 skip_ipsec:
353 #endif
354 again:
355 bzero(&rin6, sizeof(struct route_in6));
356 dst = (struct sockaddr_in6 *)&rin6.ro_dst;
357 dst->sin6_len = sizeof(struct sockaddr_in6);
358 dst->sin6_family = AF_INET6;
359 dst->sin6_addr = ip6->ip6_dst;
360 again2:
361 rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m));
362 if (rin6.ro_rt != NULL)
363 RT_UNLOCK(rin6.ro_rt);
364 else {
365 IP6STAT_INC(ip6s_noroute);
366 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute);
367 if (mcopy) {
368 icmp6_error(mcopy, ICMP6_DST_UNREACH,
369 ICMP6_DST_UNREACH_NOROUTE, 0);
370 }
371 goto bad;
372 }
373 rt = rin6.ro_rt;
374 #ifdef IPSEC
375 skip_routing:
376 #endif
377
378 /*
379 * Source scope check: if a packet can't be delivered to its
380 * destination for the reason that the destination is beyond the scope
381 * of the source address, discard the packet and return an icmp6
382 * destination unreachable error with Code 2 (beyond scope of source
383 * address). We use a local copy of ip6_src, since in6_setscope()
384 * will possibly modify its first argument.
385 * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1]
386 */
387 src_in6 = ip6->ip6_src;
388 if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) {
389 /* XXX: this should not happen */
390 IP6STAT_INC(ip6s_cantforward);
391 IP6STAT_INC(ip6s_badscope);
392 goto bad;
393 }
394 if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) {
395 IP6STAT_INC(ip6s_cantforward);
396 IP6STAT_INC(ip6s_badscope);
397 goto bad;
398 }
399 if (inzone != outzone
400 #ifdef IPSEC
401 && !ipsecrt
402 #endif
403 ) {
404 IP6STAT_INC(ip6s_cantforward);
405 IP6STAT_INC(ip6s_badscope);
406 in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard);
407
408 if (V_ip6_log_time + V_ip6_log_interval < time_uptime) {
409 V_ip6_log_time = time_uptime;
410 log(LOG_DEBUG,
411 "cannot forward "
412 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
413 ip6_sprintf(ip6bufs, &ip6->ip6_src),
414 ip6_sprintf(ip6bufd, &ip6->ip6_dst),
415 ip6->ip6_nxt,
416 if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp));
417 }
418 if (mcopy)
419 icmp6_error(mcopy, ICMP6_DST_UNREACH,
420 ICMP6_DST_UNREACH_BEYONDSCOPE, 0);
421 goto bad;
422 }
423
424 /*
425 * Destination scope check: if a packet is going to break the scope
426 * zone of packet's destination address, discard it. This case should
427 * usually be prevented by appropriately-configured routing table, but
428 * we need an explicit check because we may mistakenly forward the
429 * packet to a different zone by (e.g.) a default route.
430 */
431 dst_in6 = ip6->ip6_dst;
432 if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 ||
433 in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 ||
434 inzone != outzone) {
435 IP6STAT_INC(ip6s_cantforward);
436 IP6STAT_INC(ip6s_badscope);
437 goto bad;
438 }
439
440 if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) {
441 in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig);
442 if (mcopy) {
443 u_long mtu;
444 #ifdef IPSEC
445 struct secpolicy *sp;
446 int ipsecerror;
447 size_t ipsechdrsiz;
448 #endif /* IPSEC */
449
450 mtu = IN6_LINKMTU(rt->rt_ifp);
451 #ifdef IPSEC
452 /*
453 * When we do IPsec tunnel ingress, we need to play
454 * with the link value (decrement IPsec header size
455 * from mtu value). The code is much simpler than v4
456 * case, as we have the outgoing interface for
457 * encapsulated packet as "rt->rt_ifp".
458 */
459 sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND,
460 IP_FORWARDING, &ipsecerror);
461 if (sp) {
462 ipsechdrsiz = ipsec_hdrsiz(mcopy,
463 IPSEC_DIR_OUTBOUND, NULL);
464 if (ipsechdrsiz < mtu)
465 mtu -= ipsechdrsiz;
466 }
467
468 /*
469 * if mtu becomes less than minimum MTU,
470 * tell minimum MTU (and I'll need to fragment it).
471 */
472 if (mtu < IPV6_MMTU)
473 mtu = IPV6_MMTU;
474 #endif /* IPSEC */
475 icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu);
476 }
477 goto bad;
478 }
479
480 if (rt->rt_flags & RTF_GATEWAY)
481 dst = (struct sockaddr_in6 *)rt->rt_gateway;
482
483 /*
484 * If we are to forward the packet using the same interface
485 * as one we got the packet from, perhaps we should send a redirect
486 * to sender to shortcut a hop.
487 * Only send redirect if source is sending directly to us,
488 * and if packet was not source routed (or has any options).
489 * Also, don't send redirect if forwarding using a route
490 * modified by a redirect.
491 */
492 if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt &&
493 #ifdef IPSEC
494 !ipsecrt &&
495 #endif /* IPSEC */
496 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) {
497 if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) {
498 /*
499 * If the incoming interface is equal to the outgoing
500 * one, and the link attached to the interface is
501 * point-to-point, then it will be highly probable
502 * that a routing loop occurs. Thus, we immediately
503 * drop the packet and send an ICMPv6 error message.
504 *
505 * type/code is based on suggestion by Rich Draves.
506 * not sure if it is the best pick.
507 */
508 icmp6_error(mcopy, ICMP6_DST_UNREACH,
509 ICMP6_DST_UNREACH_ADDR, 0);
510 goto bad;
511 }
512 type = ND_REDIRECT;
513 }
514
515 /*
516 * Fake scoped addresses. Note that even link-local source or
517 * destinaion can appear, if the originating node just sends the
518 * packet to us (without address resolution for the destination).
519 * Since both icmp6_error and icmp6_redirect_output fill the embedded
520 * link identifiers, we can do this stuff after making a copy for
521 * returning an error.
522 */
523 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) {
524 /*
525 * See corresponding comments in ip6_output.
526 * XXX: but is it possible that ip6_forward() sends a packet
527 * to a loopback interface? I don't think so, and thus
528 * I bark here. (jinmei@kame.net)
529 * XXX: it is common to route invalid packets to loopback.
530 * also, the codepath will be visited on use of ::1 in
531 * rthdr. (itojun)
532 */
533 #if 1
534 if (0)
535 #else
536 if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0)
537 #endif
538 {
539 printf("ip6_forward: outgoing interface is loopback. "
540 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
541 ip6_sprintf(ip6bufs, &ip6->ip6_src),
542 ip6_sprintf(ip6bufd, &ip6->ip6_dst),
543 ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif),
544 if_name(rt->rt_ifp));
545 }
546
547 /* we can just use rcvif in forwarding. */
548 origifp = m->m_pkthdr.rcvif;
549 }
550 else
551 origifp = rt->rt_ifp;
552 /*
553 * clear embedded scope identifiers if necessary.
554 * in6_clearscope will touch the addresses only when necessary.
555 */
556 in6_clearscope(&ip6->ip6_src);
557 in6_clearscope(&ip6->ip6_dst);
558
559 /* Jump over all PFIL processing if hooks are not active. */
560 if (!PFIL_HOOKED(&V_inet6_pfil_hook))
561 goto pass;
562
563 odst = ip6->ip6_dst;
564 /* Run through list of hooks for output packets. */
565 error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL);
566 if (error != 0 || m == NULL)
567 goto freecopy; /* consumed by filter */
568 ip6 = mtod(m, struct ip6_hdr *);
569
570 /* See if destination IP address was changed by packet filter. */
571 if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
572 m->m_flags |= M_SKIP_FIREWALL;
573 /* If destination is now ourself drop to ip6_input(). */
574 if (in6_localip(&ip6->ip6_dst)) {
575 m->m_flags |= M_FASTFWD_OURS;
576 if (m->m_pkthdr.rcvif == NULL)
577 m->m_pkthdr.rcvif = V_loif;
578 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
579 m->m_pkthdr.csum_flags |=
580 CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
581 m->m_pkthdr.csum_data = 0xffff;
582 }
583 #ifdef SCTP
584 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
585 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
586 #endif
587 error = netisr_queue(NETISR_IPV6, m);
588 goto out;
589 } else
590 goto again; /* Redo the routing table lookup. */
591 }
592
593 /* See if local, if yes, send it to netisr. */
594 if (m->m_flags & M_FASTFWD_OURS) {
595 if (m->m_pkthdr.rcvif == NULL)
596 m->m_pkthdr.rcvif = V_loif;
597 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
598 m->m_pkthdr.csum_flags |=
599 CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
600 m->m_pkthdr.csum_data = 0xffff;
601 }
602 #ifdef SCTP
603 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
604 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
605 #endif
606 error = netisr_queue(NETISR_IPV6, m);
607 goto out;
608 }
609 /* Or forward to some other address? */
610 if ((m->m_flags & M_IP6_NEXTHOP) &&
611 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
612 dst = (struct sockaddr_in6 *)&rin6.ro_dst;
613 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6));
614 m->m_flags |= M_SKIP_FIREWALL;
615 m->m_flags &= ~M_IP6_NEXTHOP;
616 m_tag_delete(m, fwd_tag);
617 goto again2;
618 }
619
620 pass:
621 error = nd6_output(rt->rt_ifp, origifp, m, dst, rt);
622 if (error) {
623 in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard);
624 IP6STAT_INC(ip6s_cantforward);
625 } else {
626 IP6STAT_INC(ip6s_forward);
627 in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward);
628 if (type)
629 IP6STAT_INC(ip6s_redirectsent);
630 else {
631 if (mcopy)
632 goto freecopy;
633 }
634 }
635
636 if (mcopy == NULL)
637 goto out;
638 switch (error) {
639 case 0:
640 if (type == ND_REDIRECT) {
641 icmp6_redirect_output(mcopy, rt);
642 goto out;
643 }
644 goto freecopy;
645
646 case EMSGSIZE:
647 /* xxx MTU is constant in PPP? */
648 goto freecopy;
649
650 case ENOBUFS:
651 /* Tell source to slow down like source quench in IP? */
652 goto freecopy;
653
654 case ENETUNREACH: /* shouldn't happen, checked above */
655 case EHOSTUNREACH:
656 case ENETDOWN:
657 case EHOSTDOWN:
658 default:
659 type = ICMP6_DST_UNREACH;
660 code = ICMP6_DST_UNREACH_ADDR;
661 break;
662 }
663 icmp6_error(mcopy, type, code, 0);
664 goto out;
665
666 freecopy:
667 m_freem(mcopy);
668 goto out;
669 bad:
670 m_freem(m);
671 out:
672 if (rt != NULL
673 #ifdef IPSEC
674 && !ipsecrt
675 #endif
676 )
677 RTFREE(rt);
678 }
Cache object: 33ec64745ca2d62f2d935c72fd5915c6
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