1 /* $OpenBSD: in6_src.c,v 1.22 2006/12/11 11:26:05 itojun Exp $ */
2 /* $KAME: in6_src.c,v 1.36 2001/02/06 04:08:17 itojun 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 /*
34 * Copyright (c) 1982, 1986, 1991, 1993
35 * The Regents of the University of California. All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. Neither the name of the University nor the names of its contributors
46 * may be used to endorse or promote products derived from this software
47 * without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 *
61 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
62 */
63
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/malloc.h>
67 #include <sys/mbuf.h>
68 #include <sys/protosw.h>
69 #include <sys/socket.h>
70 #include <sys/socketvar.h>
71 #include <sys/ioctl.h>
72 #include <sys/errno.h>
73 #include <sys/time.h>
74 #include <sys/proc.h>
75
76 #include <net/if.h>
77 #include <net/route.h>
78
79 #include <netinet/in.h>
80 #include <netinet/in_var.h>
81 #include <netinet/in_systm.h>
82 #include <netinet/ip.h>
83 #include <netinet/in_pcb.h>
84 #include <netinet6/in6_var.h>
85 #include <netinet/ip6.h>
86 #include <netinet6/ip6_var.h>
87 #include <netinet6/nd6.h>
88
89 static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *,
90 struct ip6_moptions *, struct route_in6 *, struct ifnet **,
91 struct rtentry **, int);
92
93 /*
94 * Return an IPv6 address, which is the most appropriate for a given
95 * destination and user specified options.
96 * If necessary, this function lookups the routing table and returns
97 * an entry to the caller for later use.
98 */
99 struct in6_addr *
100 in6_selectsrc(dstsock, opts, mopts, ro, laddr, errorp)
101 struct sockaddr_in6 *dstsock;
102 struct ip6_pktopts *opts;
103 struct ip6_moptions *mopts;
104 struct route_in6 *ro;
105 struct in6_addr *laddr;
106 int *errorp;
107 {
108 struct in6_addr *dst;
109 struct in6_ifaddr *ia6 = 0;
110 struct in6_pktinfo *pi = NULL;
111
112 dst = &dstsock->sin6_addr;
113 *errorp = 0;
114
115 /*
116 * If the source address is explicitly specified by the caller,
117 * use it.
118 */
119 if (opts && (pi = opts->ip6po_pktinfo) &&
120 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr))
121 return (&pi->ipi6_addr);
122
123 /*
124 * If the source address is not specified but the socket(if any)
125 * is already bound, use the bound address.
126 */
127 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr))
128 return (laddr);
129
130 /*
131 * If the caller doesn't specify the source address but
132 * the outgoing interface, use an address associated with
133 * the interface.
134 */
135 if (pi && pi->ipi6_ifindex) {
136 /* XXX boundary check is assumed to be already done. */
137 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex],
138 dst);
139 if (ia6 == 0) {
140 *errorp = EADDRNOTAVAIL;
141 return (0);
142 }
143 return (&satosin6(&ia6->ia_addr)->sin6_addr);
144 }
145
146 /*
147 * If the destination address is a link-local unicast address or
148 * a link/interface-local multicast address, and if the outgoing
149 * interface is specified by the sin6_scope_id filed, use an address
150 * associated with the interface.
151 * XXX: We're now trying to define more specific semantics of
152 * sin6_scope_id field, so this part will be rewritten in
153 * the near future.
154 */
155 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MC_LINKLOCAL(dst) ||
156 IN6_IS_ADDR_MC_INTFACELOCAL(dst)) && dstsock->sin6_scope_id) {
157 /*
158 * I'm not sure if boundary check for scope_id is done
159 * somewhere...
160 */
161 if (dstsock->sin6_scope_id < 0 ||
162 if_indexlim <= dstsock->sin6_scope_id ||
163 !ifindex2ifnet[dstsock->sin6_scope_id]) {
164 *errorp = ENXIO; /* XXX: better error? */
165 return (0);
166 }
167 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id],
168 dst);
169 if (ia6 == 0) {
170 *errorp = EADDRNOTAVAIL;
171 return (0);
172 }
173 return (&satosin6(&ia6->ia_addr)->sin6_addr);
174 }
175
176 /*
177 * If the destination address is a multicast address and
178 * the outgoing interface for the address is specified
179 * by the caller, use an address associated with the interface.
180 * Even if the outgoing interface is not specified, we also
181 * choose a loopback interface as the outgoing interface.
182 */
183 if (IN6_IS_ADDR_MULTICAST(dst)) {
184 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL;
185
186 if (!ifp && dstsock->sin6_scope_id)
187 ifp = ifindex2ifnet[htons(dstsock->sin6_scope_id)];
188
189 if (ifp) {
190 ia6 = in6_ifawithscope(ifp, dst);
191 if (ia6 == 0) {
192 *errorp = EADDRNOTAVAIL;
193 return (0);
194 }
195 return (&satosin6(&ia6->ia_addr)->sin6_addr);
196 }
197 }
198
199 /*
200 * If the next hop address for the packet is specified
201 * by caller, use an address associated with the route
202 * to the next hop.
203 */
204 {
205 struct sockaddr_in6 *sin6_next;
206 struct rtentry *rt;
207
208 if (opts && opts->ip6po_nexthop) {
209 sin6_next = satosin6(opts->ip6po_nexthop);
210 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL);
211 if (rt) {
212 ia6 = in6_ifawithscope(rt->rt_ifp, dst);
213 if (ia6 == 0)
214 ia6 = ifatoia6(rt->rt_ifa);
215 }
216 if (ia6 == 0) {
217 *errorp = EADDRNOTAVAIL;
218 return (0);
219 }
220 return (&satosin6(&ia6->ia_addr)->sin6_addr);
221 }
222 }
223
224 /*
225 * If route is known or can be allocated now,
226 * our src addr is taken from the i/f, else punt.
227 */
228 if (ro) {
229 if (ro->ro_rt &&
230 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst)) {
231 RTFREE(ro->ro_rt);
232 ro->ro_rt = (struct rtentry *)0;
233 }
234 if (ro->ro_rt == (struct rtentry *)0 ||
235 ro->ro_rt->rt_ifp == (struct ifnet *)0) {
236 struct sockaddr_in6 *sa6;
237
238 /* No route yet, so try to acquire one */
239 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
240 sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
241 sa6->sin6_family = AF_INET6;
242 sa6->sin6_len = sizeof(struct sockaddr_in6);
243 sa6->sin6_addr = *dst;
244 sa6->sin6_scope_id = dstsock->sin6_scope_id;
245 if (IN6_IS_ADDR_MULTICAST(dst)) {
246 ro->ro_rt = rtalloc1(&((struct route *)ro)
247 ->ro_dst, 0, 0);
248 } else {
249 rtalloc_mpath((struct route *)ro, NULL, 0);
250 }
251 }
252
253 /*
254 * in_pcbconnect() checks out IFF_LOOPBACK to skip using
255 * the address. But we don't know why it does so.
256 * It is necessary to ensure the scope even for lo0
257 * so doesn't check out IFF_LOOPBACK.
258 */
259
260 if (ro->ro_rt) {
261 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst);
262 if (ia6 == 0) /* xxx scope error ?*/
263 ia6 = ifatoia6(ro->ro_rt->rt_ifa);
264 }
265 #if 0
266 /*
267 * xxx The followings are necessary? (kazu)
268 * I don't think so.
269 * It's for SO_DONTROUTE option in IPv4.(jinmei)
270 */
271 if (ia6 == 0) {
272 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0};
273
274 sin6->sin6_addr = *dst;
275
276 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6)));
277 if (ia6 == 0)
278 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6)));
279 if (ia6 == 0)
280 return (0);
281 return (&satosin6(&ia6->ia_addr)->sin6_addr);
282 }
283 #endif /* 0 */
284 if (ia6 == 0) {
285 *errorp = EHOSTUNREACH; /* no route */
286 return (0);
287 }
288 return (&satosin6(&ia6->ia_addr)->sin6_addr);
289 }
290
291 *errorp = EADDRNOTAVAIL;
292 return (0);
293 }
294
295 static int
296 selectroute(dstsock, opts, mopts, ro, retifp, retrt, norouteok)
297 struct sockaddr_in6 *dstsock;
298 struct ip6_pktopts *opts;
299 struct ip6_moptions *mopts;
300 struct route_in6 *ro;
301 struct ifnet **retifp;
302 struct rtentry **retrt;
303 int norouteok;
304 {
305 int error = 0;
306 struct ifnet *ifp = NULL;
307 struct rtentry *rt = NULL;
308 struct sockaddr_in6 *sin6_next;
309 struct in6_pktinfo *pi = NULL;
310 struct in6_addr *dst;
311
312 dst = &dstsock->sin6_addr;
313
314 #if 0
315 if (dstsock->sin6_addr.s6_addr32[0] == 0 &&
316 dstsock->sin6_addr.s6_addr32[1] == 0 &&
317 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) {
318 printf("in6_selectroute: strange destination %s\n",
319 ip6_sprintf(&dstsock->sin6_addr));
320 } else {
321 printf("in6_selectroute: destination = %s%%%d\n",
322 ip6_sprintf(&dstsock->sin6_addr),
323 dstsock->sin6_scope_id); /* for debug */
324 }
325 #endif
326
327 /* If the caller specify the outgoing interface explicitly, use it. */
328 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) {
329 /* XXX boundary check is assumed to be already done. */
330 ifp = ifindex2ifnet[pi->ipi6_ifindex];
331 if (ifp != NULL &&
332 (norouteok || retrt == NULL ||
333 IN6_IS_ADDR_MULTICAST(dst))) {
334 /*
335 * we do not have to check or get the route for
336 * multicast.
337 */
338 goto done;
339 } else
340 goto getroute;
341 }
342
343 /*
344 * If the destination address is a multicast address and the outgoing
345 * interface for the address is specified by the caller, use it.
346 */
347 if (IN6_IS_ADDR_MULTICAST(dst) &&
348 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) {
349 goto done; /* we do not need a route for multicast. */
350 }
351
352 getroute:
353 /*
354 * If the next hop address for the packet is specified by the caller,
355 * use it as the gateway.
356 */
357 if (opts && opts->ip6po_nexthop) {
358 struct route_in6 *ron;
359
360 sin6_next = satosin6(opts->ip6po_nexthop);
361
362 /* at this moment, we only support AF_INET6 next hops */
363 if (sin6_next->sin6_family != AF_INET6) {
364 error = EAFNOSUPPORT; /* or should we proceed? */
365 goto done;
366 }
367
368 /*
369 * If the next hop is an IPv6 address, then the node identified
370 * by that address must be a neighbor of the sending host.
371 */
372 ron = &opts->ip6po_nextroute;
373 if ((ron->ro_rt &&
374 (ron->ro_rt->rt_flags & (RTF_UP | RTF_GATEWAY)) !=
375 RTF_UP) ||
376 !IN6_ARE_ADDR_EQUAL(&satosin6(&ron->ro_dst)->sin6_addr,
377 &sin6_next->sin6_addr)) {
378 if (ron->ro_rt) {
379 RTFREE(ron->ro_rt);
380 ron->ro_rt = NULL;
381 }
382 *satosin6(&ron->ro_dst) = *sin6_next;
383 }
384 if (ron->ro_rt == NULL) {
385 rtalloc((struct route *)ron); /* multi path case? */
386 if (ron->ro_rt == NULL ||
387 (ron->ro_rt->rt_flags & RTF_GATEWAY)) {
388 if (ron->ro_rt) {
389 RTFREE(ron->ro_rt);
390 ron->ro_rt = NULL;
391 }
392 error = EHOSTUNREACH;
393 goto done;
394 }
395 }
396 if (!nd6_is_addr_neighbor(sin6_next, ron->ro_rt->rt_ifp)) {
397 RTFREE(ron->ro_rt);
398 ron->ro_rt = NULL;
399 error = EHOSTUNREACH;
400 goto done;
401 }
402 rt = ron->ro_rt;
403 ifp = rt->rt_ifp;
404
405 /*
406 * When cloning is required, try to allocate a route to the
407 * destination so that the caller can store path MTU
408 * information.
409 */
410 goto done;
411 }
412
413 /*
414 * Use a cached route if it exists and is valid, else try to allocate
415 * a new one. Note that we should check the address family of the
416 * cached destination, in case of sharing the cache with IPv4.
417 */
418 if (ro) {
419 if (ro->ro_rt &&
420 (!(ro->ro_rt->rt_flags & RTF_UP) ||
421 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 ||
422 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr,
423 dst))) {
424 RTFREE(ro->ro_rt);
425 ro->ro_rt = (struct rtentry *)NULL;
426 }
427 if (ro->ro_rt == (struct rtentry *)NULL) {
428 struct sockaddr_in6 *sa6;
429
430 /* No route yet, so try to acquire one */
431 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
432 sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
433 *sa6 = *dstsock;
434 sa6->sin6_scope_id = 0;
435 rtalloc_mpath((struct route *)ro, NULL, 0);
436 }
437
438 /*
439 * do not care about the result if we have the nexthop
440 * explicitly specified.
441 */
442 if (opts && opts->ip6po_nexthop)
443 goto done;
444
445 if (ro->ro_rt) {
446 ifp = ro->ro_rt->rt_ifp;
447
448 if (ifp == NULL) { /* can this really happen? */
449 RTFREE(ro->ro_rt);
450 ro->ro_rt = NULL;
451 }
452 }
453 if (ro->ro_rt == NULL)
454 error = EHOSTUNREACH;
455 rt = ro->ro_rt;
456
457 /*
458 * Check if the outgoing interface conflicts with
459 * the interface specified by ipi6_ifindex (if specified).
460 * Note that loopback interface is always okay.
461 * (this may happen when we are sending a packet to one of
462 * our own addresses.)
463 */
464 if (opts && opts->ip6po_pktinfo &&
465 opts->ip6po_pktinfo->ipi6_ifindex) {
466 if (!(ifp->if_flags & IFF_LOOPBACK) &&
467 ifp->if_index !=
468 opts->ip6po_pktinfo->ipi6_ifindex) {
469 error = EHOSTUNREACH;
470 goto done;
471 }
472 }
473 }
474
475 done:
476 if (ifp == NULL && rt == NULL) {
477 /*
478 * This can happen if the caller did not pass a cached route
479 * nor any other hints. We treat this case an error.
480 */
481 error = EHOSTUNREACH;
482 }
483 if (error == EHOSTUNREACH)
484 ip6stat.ip6s_noroute++;
485
486 if (retifp != NULL)
487 *retifp = ifp;
488 if (retrt != NULL)
489 *retrt = rt; /* rt may be NULL */
490
491 return (error);
492 }
493
494 int
495 in6_selectroute(dstsock, opts, mopts, ro, retifp, retrt)
496 struct sockaddr_in6 *dstsock;
497 struct ip6_pktopts *opts;
498 struct ip6_moptions *mopts;
499 struct route_in6 *ro;
500 struct ifnet **retifp;
501 struct rtentry **retrt;
502 {
503
504 return (selectroute(dstsock, opts, mopts, ro, retifp, retrt, 0));
505 }
506
507 /*
508 * Default hop limit selection. The precedence is as follows:
509 * 1. Hoplimit value specified via ioctl.
510 * 2. (If the outgoing interface is detected) the current
511 * hop limit of the interface specified by router advertisement.
512 * 3. The system default hoplimit.
513 */
514 #define in6pcb inpcb
515 #define in6p_hops inp_hops
516 int
517 in6_selecthlim(in6p, ifp)
518 struct in6pcb *in6p;
519 struct ifnet *ifp;
520 {
521 if (in6p && in6p->in6p_hops >= 0)
522 return (in6p->in6p_hops);
523 else if (ifp)
524 return (ND_IFINFO(ifp)->chlim);
525 else
526 return (ip6_defhlim);
527 }
528 #undef in6pcb
529 #undef in6p_hops
530
531 /*
532 * generate kernel-internal form (scopeid embedded into s6_addr16[1]).
533 * If the address scope of is link-local, embed the interface index in the
534 * address. The routine determines our precedence
535 * between advanced API scope/interface specification and basic API
536 * specification.
537 *
538 * this function should be nuked in the future, when we get rid of
539 * embedded scopeid thing.
540 *
541 * XXX actually, it is over-specification to return ifp against sin6_scope_id.
542 * there can be multiple interfaces that belong to a particular scope zone
543 * (in specification, we have 1:N mapping between a scope zone and interfaces).
544 * we may want to change the function to return something other than ifp.
545 */
546 int
547 in6_embedscope(in6, sin6, in6p, ifpp)
548 struct in6_addr *in6;
549 const struct sockaddr_in6 *sin6;
550 struct inpcb *in6p;
551 #define in6p_outputopts inp_outputopts6
552 #define in6p_moptions inp_moptions6
553 struct ifnet **ifpp;
554 {
555 struct ifnet *ifp = NULL;
556 u_int32_t scopeid;
557
558 *in6 = sin6->sin6_addr;
559 scopeid = sin6->sin6_scope_id;
560 if (ifpp)
561 *ifpp = NULL;
562
563 /*
564 * don't try to read sin6->sin6_addr beyond here, since the caller may
565 * ask us to overwrite existing sockaddr_in6
566 */
567
568 if (IN6_IS_SCOPE_EMBED(in6)) {
569 struct in6_pktinfo *pi;
570
571 /*
572 * KAME assumption: link id == interface id
573 */
574
575 if (in6p && in6p->in6p_outputopts &&
576 (pi = in6p->in6p_outputopts->ip6po_pktinfo) &&
577 pi->ipi6_ifindex) {
578 ifp = ifindex2ifnet[pi->ipi6_ifindex];
579 in6->s6_addr16[1] = htons(pi->ipi6_ifindex);
580 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) &&
581 in6p->in6p_moptions &&
582 in6p->in6p_moptions->im6o_multicast_ifp) {
583 ifp = in6p->in6p_moptions->im6o_multicast_ifp;
584 in6->s6_addr16[1] = htons(ifp->if_index);
585 } else if (scopeid) {
586 /* boundary check */
587 if (scopeid < 0 || if_indexlim <= scopeid ||
588 !ifindex2ifnet[scopeid])
589 return ENXIO; /* XXX EINVAL? */
590 ifp = ifindex2ifnet[scopeid];
591 /*XXX assignment to 16bit from 32bit variable */
592 in6->s6_addr16[1] = htons(scopeid & 0xffff);
593 }
594
595 if (ifpp)
596 *ifpp = ifp;
597 }
598
599 return 0;
600 }
601 #undef in6p_outputopts
602 #undef in6p_moptions
603
604 /*
605 * generate standard sockaddr_in6 from embedded form.
606 * touches sin6_addr and sin6_scope_id only.
607 *
608 * this function should be nuked in the future, when we get rid of
609 * embedded scopeid thing.
610 */
611 int
612 in6_recoverscope(sin6, in6, ifp)
613 struct sockaddr_in6 *sin6;
614 const struct in6_addr *in6;
615 struct ifnet *ifp;
616 {
617 u_int32_t scopeid;
618
619 sin6->sin6_addr = *in6;
620
621 /*
622 * don't try to read *in6 beyond here, since the caller may
623 * ask us to overwrite existing sockaddr_in6
624 */
625
626 sin6->sin6_scope_id = 0;
627 if (IN6_IS_SCOPE_EMBED(in6)) {
628 /*
629 * KAME assumption: link id == interface id
630 */
631 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]);
632 if (scopeid) {
633 /* sanity check */
634 if (scopeid < 0 || if_indexlim <= scopeid ||
635 !ifindex2ifnet[scopeid])
636 return ENXIO;
637 if (ifp && ifp->if_index != scopeid)
638 return ENXIO;
639 sin6->sin6_addr.s6_addr16[1] = 0;
640 sin6->sin6_scope_id = scopeid;
641 }
642 }
643
644 return 0;
645 }
646
647 /*
648 * just clear the embedded scope identifer.
649 */
650 void
651 in6_clearscope(addr)
652 struct in6_addr *addr;
653 {
654 if (IN6_IS_SCOPE_EMBED(addr))
655 addr->s6_addr16[1] = 0;
656 }