1 /* $FreeBSD: src/sys/netinet6/in6_src.c,v 1.1.2.3 2002/02/26 18:02:06 ume Exp $ */
2 /* $DragonFly: src/sys/netinet6/in6_src.c,v 1.7 2004/05/20 18:30:36 cpressey Exp $ */
3 /* $KAME: in6_src.c,v 1.37 2001/03/29 05:34:31 itojun Exp $ */
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66 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
70 #include "opt_inet6.h"
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/malloc.h>
76 #include <sys/protosw.h>
77 #include <sys/socket.h>
78 #include <sys/socketvar.h>
79 #include <sys/errno.h>
84 #include <net/route.h>
86 #include <netinet/in.h>
87 #include <netinet/in_var.h>
88 #include <netinet/in_systm.h>
89 #include <netinet/ip.h>
90 #include <netinet/in_pcb.h>
91 #include <netinet6/in6_var.h>
92 #include <netinet/ip6.h>
93 #include <netinet6/in6_pcb.h>
94 #include <netinet6/ip6_var.h>
95 #include <netinet6/nd6.h>
96 #ifdef ENABLE_DEFAULT_SCOPE
97 #include <netinet6/scope6_var.h>
100 #include <net/net_osdep.h>
102 #include "use_loop.h"
105 * Return an IPv6 address, which is the most appropriate for a given
106 * destination and user specified options.
107 * If necessary, this function lookups the routing table and returns
108 * an entry to the caller for later use.
111 in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
112 struct ip6_moptions *mopts, struct route_in6 *ro,
113 struct in6_addr *laddr, int *errorp)
115 struct in6_addr *dst;
116 struct in6_ifaddr *ia6 = 0;
117 struct in6_pktinfo *pi = NULL;
119 dst = &dstsock->sin6_addr;
123 * If the source address is explicitly specified by the caller,
126 if (opts && (pi = opts->ip6po_pktinfo) &&
127 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr))
128 return(&pi->ipi6_addr);
131 * If the source address is not specified but the socket(if any)
132 * is already bound, use the bound address.
134 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr))
138 * If the caller doesn't specify the source address but
139 * the outgoing interface, use an address associated with
142 if (pi && pi->ipi6_ifindex) {
143 /* XXX boundary check is assumed to be already done. */
144 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex],
147 *errorp = EADDRNOTAVAIL;
150 return(&satosin6(&ia6->ia_addr)->sin6_addr);
154 * If the destination address is a link-local unicast address or
155 * a multicast address, and if the outgoing interface is specified
156 * by the sin6_scope_id filed, use an address associated with the
158 * XXX: We're now trying to define more specific semantics of
159 * sin6_scope_id field, so this part will be rewritten in
162 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) &&
163 dstsock->sin6_scope_id) {
165 * I'm not sure if boundary check for scope_id is done
168 if (dstsock->sin6_scope_id < 0 ||
169 if_index < dstsock->sin6_scope_id) {
170 *errorp = ENXIO; /* XXX: better error? */
173 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id],
176 *errorp = EADDRNOTAVAIL;
179 return(&satosin6(&ia6->ia_addr)->sin6_addr);
183 * If the destination address is a multicast address and
184 * the outgoing interface for the address is specified
185 * by the caller, use an address associated with the interface.
186 * There is a sanity check here; if the destination has node-local
187 * scope, the outgoing interfacde should be a loopback address.
188 * Even if the outgoing interface is not specified, we also
189 * choose a loopback interface as the outgoing interface.
191 if (IN6_IS_ADDR_MULTICAST(dst)) {
192 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL;
194 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) {
199 ia6 = in6_ifawithscope(ifp, dst);
201 *errorp = EADDRNOTAVAIL;
204 return(&satosin6(&ia6->ia_addr)->sin6_addr);
209 * If the next hop address for the packet is specified
210 * by caller, use an address associated with the route
214 struct sockaddr_in6 *sin6_next;
217 if (opts && opts->ip6po_nexthop) {
218 sin6_next = satosin6(opts->ip6po_nexthop);
219 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL);
221 ia6 = in6_ifawithscope(rt->rt_ifp, dst);
223 ia6 = ifatoia6(rt->rt_ifa);
226 *errorp = EADDRNOTAVAIL;
229 return(&satosin6(&ia6->ia_addr)->sin6_addr);
234 * If route is known or can be allocated now,
235 * our src addr is taken from the i/f, else punt.
239 (!(ro->ro_rt->rt_flags & RTF_UP) ||
240 satosin6(&ro->ro_dst)->sin6_family != AF_INET6 ||
241 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr,
244 ro->ro_rt = (struct rtentry *)0;
246 if (ro->ro_rt == (struct rtentry *)0 ||
247 ro->ro_rt->rt_ifp == (struct ifnet *)0) {
248 struct sockaddr_in6 *sa6;
250 /* No route yet, so try to acquire one */
251 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
252 sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
253 sa6->sin6_family = AF_INET6;
254 sa6->sin6_len = sizeof(struct sockaddr_in6);
255 sa6->sin6_addr = *dst;
256 sa6->sin6_scope_id = dstsock->sin6_scope_id;
257 if (IN6_IS_ADDR_MULTICAST(dst)) {
258 ro->ro_rt = rtalloc1(&((struct route *)ro)
261 rtalloc((struct route *)ro);
266 * in_pcbconnect() checks out IFF_LOOPBACK to skip using
267 * the address. But we don't know why it does so.
268 * It is necessary to ensure the scope even for lo0
269 * so doesn't check out IFF_LOOPBACK.
273 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst);
274 if (ia6 == 0) /* xxx scope error ?*/
275 ia6 = ifatoia6(ro->ro_rt->rt_ifa);
279 * xxx The followings are necessary? (kazu)
281 * It's for SO_DONTROUTE option in IPv4.(jinmei)
284 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0};
286 sin6->sin6_addr = *dst;
288 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6)));
290 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6)));
293 return(&satosin6(&ia6->ia_addr)->sin6_addr);
297 *errorp = EHOSTUNREACH; /* no route */
300 return(&satosin6(&ia6->ia_addr)->sin6_addr);
303 *errorp = EADDRNOTAVAIL;
308 * Default hop limit selection. The precedence is as follows:
309 * 1. Hoplimit value specified via ioctl.
310 * 2. (If the outgoing interface is detected) the current
311 * hop limit of the interface specified by router advertisement.
312 * 3. The system default hoplimit.
315 in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp)
317 if (in6p && in6p->in6p_hops >= 0)
318 return(in6p->in6p_hops);
320 return(nd_ifinfo[ifp->if_index].chlim);
326 * XXX: this is borrowed from in6_pcbbind(). If possible, we should
327 * share this function by all *bsd*...
330 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct thread *td)
332 struct socket *so = inp->inp_socket;
333 u_int16_t lport = 0, first, last, *lastport;
334 int count, error = 0, wild = 0;
335 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
337 /* XXX: this is redundant when called from in6_pcbbind */
338 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
339 wild = INPLOOKUP_WILDCARD;
341 inp->inp_flags |= INP_ANONPORT;
343 if (inp->inp_flags & INP_HIGHPORT) {
344 first = ipport_hifirstauto; /* sysctl */
345 last = ipport_hilastauto;
346 lastport = &pcbinfo->lasthi;
347 } else if (inp->inp_flags & INP_LOWPORT) {
348 if ((error = suser(td)) != 0)
350 first = ipport_lowfirstauto; /* 1023 */
351 last = ipport_lowlastauto; /* 600 */
352 lastport = &pcbinfo->lastlow;
354 first = ipport_firstauto; /* sysctl */
355 last = ipport_lastauto;
356 lastport = &pcbinfo->lastport;
359 * Simple check to ensure all ports are not used up causing
362 * We split the two cases (up and down) so that the direction
363 * is not being tested on each round of the loop.
369 count = first - last;
372 if (count-- < 0) { /* completely used? */
374 * Undo any address bind that may have
377 inp->in6p_laddr = in6addr_any;
381 if (*lastport > first || *lastport < last)
383 lport = htons(*lastport);
384 } while (in6_pcblookup_local(pcbinfo,
385 &inp->in6p_laddr, lport, wild));
390 count = last - first;
393 if (count-- < 0) { /* completely used? */
395 * Undo any address bind that may have
398 inp->in6p_laddr = in6addr_any;
402 if (*lastport < first || *lastport > last)
404 lport = htons(*lastport);
405 } while (in6_pcblookup_local(pcbinfo,
406 &inp->in6p_laddr, lport, wild));
409 inp->inp_lport = lport;
410 if (in_pcbinsporthash(inp) != 0) {
411 inp->in6p_laddr = in6addr_any;
420 * generate kernel-internal form (scopeid embedded into s6_addr16[1]).
421 * If the address scope of is link-local, embed the interface index in the
422 * address. The routine determines our precedence
423 * between advanced API scope/interface specification and basic API
426 * this function should be nuked in the future, when we get rid of
427 * embedded scopeid thing.
429 * XXX actually, it is over-specification to return ifp against sin6_scope_id.
430 * there can be multiple interfaces that belong to a particular scope zone
431 * (in specification, we have 1:N mapping between a scope zone and interfaces).
432 * we may want to change the function to return something other than ifp.
435 in6_embedscope(struct in6_addr *in6,
436 const struct sockaddr_in6 *sin6,
437 #ifdef HAVE_NRL_INPCB
439 #define in6p_outputopts inp_outputopts6
440 #define in6p_moptions inp_moptions6
446 struct ifnet *ifp = NULL;
449 *in6 = sin6->sin6_addr;
450 scopeid = sin6->sin6_scope_id;
455 * don't try to read sin6->sin6_addr beyond here, since the caller may
456 * ask us to overwrite existing sockaddr_in6
459 #ifdef ENABLE_DEFAULT_SCOPE
461 scopeid = scope6_addr2default(in6);
464 if (IN6_IS_SCOPE_LINKLOCAL(in6)) {
465 struct in6_pktinfo *pi;
468 * KAME assumption: link id == interface id
471 if (in6p && in6p->in6p_outputopts &&
472 (pi = in6p->in6p_outputopts->ip6po_pktinfo) &&
474 ifp = ifindex2ifnet[pi->ipi6_ifindex];
475 in6->s6_addr16[1] = htons(pi->ipi6_ifindex);
476 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) &&
477 in6p->in6p_moptions &&
478 in6p->in6p_moptions->im6o_multicast_ifp) {
479 ifp = in6p->in6p_moptions->im6o_multicast_ifp;
480 in6->s6_addr16[1] = htons(ifp->if_index);
481 } else if (scopeid) {
483 if (scopeid < 0 || if_index < scopeid)
484 return ENXIO; /* XXX EINVAL? */
485 ifp = ifindex2ifnet[scopeid];
486 /*XXX assignment to 16bit from 32bit variable */
487 in6->s6_addr16[1] = htons(scopeid & 0xffff);
496 #ifdef HAVE_NRL_INPCB
497 #undef in6p_outputopts
502 * generate standard sockaddr_in6 from embedded form.
503 * touches sin6_addr and sin6_scope_id only.
505 * this function should be nuked in the future, when we get rid of
506 * embedded scopeid thing.
509 in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6,
514 sin6->sin6_addr = *in6;
517 * don't try to read *in6 beyond here, since the caller may
518 * ask us to overwrite existing sockaddr_in6
521 sin6->sin6_scope_id = 0;
522 if (IN6_IS_SCOPE_LINKLOCAL(in6)) {
524 * KAME assumption: link id == interface id
526 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]);
529 if (scopeid < 0 || if_index < scopeid)
531 if (ifp && ifp->if_index != scopeid)
533 sin6->sin6_addr.s6_addr16[1] = 0;
534 sin6->sin6_scope_id = scopeid;
542 * just clear the embedded scope identifer.
543 * XXX: currently used for bsdi4 only as a supplement function.
546 in6_clearscope(struct in6_addr *addr)
548 if (IN6_IS_SCOPE_LINKLOCAL(addr))
549 addr->s6_addr16[1] = 0;