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 1.3 2003/06/23 17:55:47 dillon 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>
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(dstsock, opts, mopts, ro, laddr, errorp)
112 struct sockaddr_in6 *dstsock;
113 struct ip6_pktopts *opts;
114 struct ip6_moptions *mopts;
115 struct route_in6 *ro;
116 struct in6_addr *laddr;
119 struct in6_addr *dst;
120 struct in6_ifaddr *ia6 = 0;
121 struct in6_pktinfo *pi = NULL;
123 dst = &dstsock->sin6_addr;
127 * If the source address is explicitly specified by the caller,
130 if (opts && (pi = opts->ip6po_pktinfo) &&
131 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr))
132 return(&pi->ipi6_addr);
135 * If the source address is not specified but the socket(if any)
136 * is already bound, use the bound address.
138 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr))
142 * If the caller doesn't specify the source address but
143 * the outgoing interface, use an address associated with
146 if (pi && pi->ipi6_ifindex) {
147 /* XXX boundary check is assumed to be already done. */
148 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex],
151 *errorp = EADDRNOTAVAIL;
154 return(&satosin6(&ia6->ia_addr)->sin6_addr);
158 * If the destination address is a link-local unicast address or
159 * a multicast address, and if the outgoing interface is specified
160 * by the sin6_scope_id filed, use an address associated with the
162 * XXX: We're now trying to define more specific semantics of
163 * sin6_scope_id field, so this part will be rewritten in
166 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) &&
167 dstsock->sin6_scope_id) {
169 * I'm not sure if boundary check for scope_id is done
172 if (dstsock->sin6_scope_id < 0 ||
173 if_index < dstsock->sin6_scope_id) {
174 *errorp = ENXIO; /* XXX: better error? */
177 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id],
180 *errorp = EADDRNOTAVAIL;
183 return(&satosin6(&ia6->ia_addr)->sin6_addr);
187 * If the destination address is a multicast address and
188 * the outgoing interface for the address is specified
189 * by the caller, use an address associated with the interface.
190 * There is a sanity check here; if the destination has node-local
191 * scope, the outgoing interfacde should be a loopback address.
192 * Even if the outgoing interface is not specified, we also
193 * choose a loopback interface as the outgoing interface.
195 if (IN6_IS_ADDR_MULTICAST(dst)) {
196 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL;
198 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) {
203 ia6 = in6_ifawithscope(ifp, dst);
205 *errorp = EADDRNOTAVAIL;
208 return(&satosin6(&ia6->ia_addr)->sin6_addr);
213 * If the next hop address for the packet is specified
214 * by caller, use an address associated with the route
218 struct sockaddr_in6 *sin6_next;
221 if (opts && opts->ip6po_nexthop) {
222 sin6_next = satosin6(opts->ip6po_nexthop);
223 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL);
225 ia6 = in6_ifawithscope(rt->rt_ifp, dst);
227 ia6 = ifatoia6(rt->rt_ifa);
230 *errorp = EADDRNOTAVAIL;
233 return(&satosin6(&ia6->ia_addr)->sin6_addr);
238 * If route is known or can be allocated now,
239 * our src addr is taken from the i/f, else punt.
243 (!(ro->ro_rt->rt_flags & RTF_UP) ||
244 satosin6(&ro->ro_dst)->sin6_family != AF_INET6 ||
245 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr,
248 ro->ro_rt = (struct rtentry *)0;
250 if (ro->ro_rt == (struct rtentry *)0 ||
251 ro->ro_rt->rt_ifp == (struct ifnet *)0) {
252 struct sockaddr_in6 *sa6;
254 /* No route yet, so try to acquire one */
255 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
256 sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
257 sa6->sin6_family = AF_INET6;
258 sa6->sin6_len = sizeof(struct sockaddr_in6);
259 sa6->sin6_addr = *dst;
260 sa6->sin6_scope_id = dstsock->sin6_scope_id;
261 if (IN6_IS_ADDR_MULTICAST(dst)) {
262 ro->ro_rt = rtalloc1(&((struct route *)ro)
265 rtalloc((struct route *)ro);
270 * in_pcbconnect() checks out IFF_LOOPBACK to skip using
271 * the address. But we don't know why it does so.
272 * It is necessary to ensure the scope even for lo0
273 * so doesn't check out IFF_LOOPBACK.
277 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst);
278 if (ia6 == 0) /* xxx scope error ?*/
279 ia6 = ifatoia6(ro->ro_rt->rt_ifa);
283 * xxx The followings are necessary? (kazu)
285 * It's for SO_DONTROUTE option in IPv4.(jinmei)
288 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0};
290 sin6->sin6_addr = *dst;
292 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6)));
294 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6)));
297 return(&satosin6(&ia6->ia_addr)->sin6_addr);
301 *errorp = EHOSTUNREACH; /* no route */
304 return(&satosin6(&ia6->ia_addr)->sin6_addr);
307 *errorp = EADDRNOTAVAIL;
312 * Default hop limit selection. The precedence is as follows:
313 * 1. Hoplimit value specified via ioctl.
314 * 2. (If the outgoing interface is detected) the current
315 * hop limit of the interface specified by router advertisement.
316 * 3. The system default hoplimit.
319 in6_selecthlim(in6p, ifp)
323 if (in6p && in6p->in6p_hops >= 0)
324 return(in6p->in6p_hops);
326 return(nd_ifinfo[ifp->if_index].chlim);
332 * XXX: this is borrowed from in6_pcbbind(). If possible, we should
333 * share this function by all *bsd*...
336 in6_pcbsetport(laddr, inp, p)
337 struct in6_addr *laddr;
341 struct socket *so = inp->inp_socket;
342 u_int16_t lport = 0, first, last, *lastport;
343 int count, error = 0, wild = 0;
344 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
346 /* XXX: this is redundant when called from in6_pcbbind */
347 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
348 wild = INPLOOKUP_WILDCARD;
350 inp->inp_flags |= INP_ANONPORT;
352 if (inp->inp_flags & INP_HIGHPORT) {
353 first = ipport_hifirstauto; /* sysctl */
354 last = ipport_hilastauto;
355 lastport = &pcbinfo->lasthi;
356 } else if (inp->inp_flags & INP_LOWPORT) {
357 if (p && (error = suser_xxx(p->p_ucred, 0)))
359 first = ipport_lowfirstauto; /* 1023 */
360 last = ipport_lowlastauto; /* 600 */
361 lastport = &pcbinfo->lastlow;
363 first = ipport_firstauto; /* sysctl */
364 last = ipport_lastauto;
365 lastport = &pcbinfo->lastport;
368 * Simple check to ensure all ports are not used up causing
371 * We split the two cases (up and down) so that the direction
372 * is not being tested on each round of the loop.
378 count = first - last;
381 if (count-- < 0) { /* completely used? */
383 * Undo any address bind that may have
386 inp->in6p_laddr = in6addr_any;
390 if (*lastport > first || *lastport < last)
392 lport = htons(*lastport);
393 } while (in6_pcblookup_local(pcbinfo,
394 &inp->in6p_laddr, lport, wild));
399 count = last - first;
402 if (count-- < 0) { /* completely used? */
404 * Undo any address bind that may have
407 inp->in6p_laddr = in6addr_any;
411 if (*lastport < first || *lastport > last)
413 lport = htons(*lastport);
414 } while (in6_pcblookup_local(pcbinfo,
415 &inp->in6p_laddr, lport, wild));
418 inp->inp_lport = lport;
419 if (in_pcbinshash(inp) != 0) {
420 inp->in6p_laddr = in6addr_any;
429 * generate kernel-internal form (scopeid embedded into s6_addr16[1]).
430 * If the address scope of is link-local, embed the interface index in the
431 * address. The routine determines our precedence
432 * between advanced API scope/interface specification and basic API
435 * this function should be nuked in the future, when we get rid of
436 * embedded scopeid thing.
438 * XXX actually, it is over-specification to return ifp against sin6_scope_id.
439 * there can be multiple interfaces that belong to a particular scope zone
440 * (in specification, we have 1:N mapping between a scope zone and interfaces).
441 * we may want to change the function to return something other than ifp.
444 in6_embedscope(in6, sin6, in6p, ifpp)
445 struct in6_addr *in6;
446 const struct sockaddr_in6 *sin6;
447 #ifdef HAVE_NRL_INPCB
449 #define in6p_outputopts inp_outputopts6
450 #define in6p_moptions inp_moptions6
456 struct ifnet *ifp = NULL;
459 *in6 = sin6->sin6_addr;
460 scopeid = sin6->sin6_scope_id;
465 * don't try to read sin6->sin6_addr beyond here, since the caller may
466 * ask us to overwrite existing sockaddr_in6
469 #ifdef ENABLE_DEFAULT_SCOPE
471 scopeid = scope6_addr2default(in6);
474 if (IN6_IS_SCOPE_LINKLOCAL(in6)) {
475 struct in6_pktinfo *pi;
478 * KAME assumption: link id == interface id
481 if (in6p && in6p->in6p_outputopts &&
482 (pi = in6p->in6p_outputopts->ip6po_pktinfo) &&
484 ifp = ifindex2ifnet[pi->ipi6_ifindex];
485 in6->s6_addr16[1] = htons(pi->ipi6_ifindex);
486 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) &&
487 in6p->in6p_moptions &&
488 in6p->in6p_moptions->im6o_multicast_ifp) {
489 ifp = in6p->in6p_moptions->im6o_multicast_ifp;
490 in6->s6_addr16[1] = htons(ifp->if_index);
491 } else if (scopeid) {
493 if (scopeid < 0 || if_index < scopeid)
494 return ENXIO; /* XXX EINVAL? */
495 ifp = ifindex2ifnet[scopeid];
496 /*XXX assignment to 16bit from 32bit variable */
497 in6->s6_addr16[1] = htons(scopeid & 0xffff);
506 #ifdef HAVE_NRL_INPCB
507 #undef in6p_outputopts
512 * generate standard sockaddr_in6 from embedded form.
513 * touches sin6_addr and sin6_scope_id only.
515 * this function should be nuked in the future, when we get rid of
516 * embedded scopeid thing.
519 in6_recoverscope(sin6, in6, ifp)
520 struct sockaddr_in6 *sin6;
521 const struct in6_addr *in6;
526 sin6->sin6_addr = *in6;
529 * don't try to read *in6 beyond here, since the caller may
530 * ask us to overwrite existing sockaddr_in6
533 sin6->sin6_scope_id = 0;
534 if (IN6_IS_SCOPE_LINKLOCAL(in6)) {
536 * KAME assumption: link id == interface id
538 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]);
541 if (scopeid < 0 || if_index < scopeid)
543 if (ifp && ifp->if_index != scopeid)
545 sin6->sin6_addr.s6_addr16[1] = 0;
546 sin6->sin6_scope_id = scopeid;
554 * just clear the embedded scope identifer.
555 * XXX: currently used for bsdi4 only as a supplement function.
559 struct in6_addr *addr;
561 if (IN6_IS_SCOPE_LINKLOCAL(addr))
562 addr->s6_addr16[1] = 0;