/* $OpenBSD: in6_src.c,v 1.15 2003/06/02 23:28:15 millert Exp $ */ /* $KAME: in6_src.c,v 1.36 2001/02/06 04:08:17 itojun Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Copyright (c) 1982, 1986, 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94 */ #include <sys/param.h> #include <sys/systm.h> #include <sys/malloc.h> #include <sys/mbuf.h> #include <sys/protosw.h> #include <sys/socket.h> #include <sys/socketvar.h> #include <sys/ioctl.h> #include <sys/errno.h> #include <sys/time.h> #include <sys/proc.h> #include <net/if.h> #include <net/route.h> #include <netinet/in.h> #include <netinet/in_var.h> #include <netinet/in_systm.h> #include <netinet/ip.h> #include <netinet/in_pcb.h> #include <netinet6/in6_var.h> #include <netinet/ip6.h> #include <netinet6/ip6_var.h> #include <netinet6/nd6.h> /* * Return an IPv6 address, which is the most appropriate for a given * destination and user specified options. * If necessary, this function lookups the routing table and returns * an entry to the caller for later use. */ struct in6_addr * in6_selectsrc(dstsock, opts, mopts, ro, laddr, errorp) struct sockaddr_in6 *dstsock; struct ip6_pktopts *opts; struct ip6_moptions *mopts; struct route_in6 *ro; struct in6_addr *laddr; int *errorp; { struct in6_addr *dst; struct in6_ifaddr *ia6 = 0; struct in6_pktinfo *pi = NULL; dst = &dstsock->sin6_addr; *errorp = 0; /* * If the source address is explicitly specified by the caller, * use it. */ if (opts && (pi = opts->ip6po_pktinfo) && !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) return (&pi->ipi6_addr); /* * If the source address is not specified but the socket(if any) * is already bound, use the bound address. */ if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) return (laddr); /* * If the caller doesn't specify the source address but * the outgoing interface, use an address associated with * the interface. */ if (pi && pi->ipi6_ifindex) { /* XXX boundary check is assumed to be already done. */ ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], dst); if (ia6 == 0) { *errorp = EADDRNOTAVAIL; return (0); } return (&satosin6(&ia6->ia_addr)->sin6_addr); } /* * If the destination address is a link-local unicast address or * a multicast address, and if the outgoing interface is specified * by the sin6_scope_id filed, use an address associated with the * interface. * XXX: We're now trying to define more specific semantics of * sin6_scope_id field, so this part will be rewritten in * the near future. */ if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) && dstsock->sin6_scope_id) { /* * I'm not sure if boundary check for scope_id is done * somewhere... */ if (dstsock->sin6_scope_id < 0 || if_index < dstsock->sin6_scope_id) { *errorp = ENXIO; /* XXX: better error? */ return (0); } ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id], dst); if (ia6 == 0) { *errorp = EADDRNOTAVAIL; return (0); } return (&satosin6(&ia6->ia_addr)->sin6_addr); } /* * If the destination address is a multicast address and * the outgoing interface for the address is specified * by the caller, use an address associated with the interface. * There is a sanity check here; if the destination has node-local * scope, the outgoing interfacde should be a loopback address. * Even if the outgoing interface is not specified, we also * choose a loopback interface as the outgoing interface. */ if (IN6_IS_ADDR_MULTICAST(dst)) { struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) { ifp = lo0ifp; } if (ifp) { ia6 = in6_ifawithscope(ifp, dst); if (ia6 == 0) { *errorp = EADDRNOTAVAIL; return (0); } return (&satosin6(&ia6->ia_addr)->sin6_addr); } } /* * If the next hop address for the packet is specified * by caller, use an address associated with the route * to the next hop. */ { struct sockaddr_in6 *sin6_next; struct rtentry *rt; if (opts && opts->ip6po_nexthop) { sin6_next = satosin6(opts->ip6po_nexthop); rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); if (rt) { ia6 = in6_ifawithscope(rt->rt_ifp, dst); if (ia6 == 0) ia6 = ifatoia6(rt->rt_ifa); } if (ia6 == 0) { *errorp = EADDRNOTAVAIL; return (0); } return (&satosin6(&ia6->ia_addr)->sin6_addr); } } /* * If route is known or can be allocated now, * our src addr is taken from the i/f, else punt. */ if (ro) { if (ro->ro_rt && !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst)) { RTFREE(ro->ro_rt); ro->ro_rt = (struct rtentry *)0; } if (ro->ro_rt == (struct rtentry *)0 || ro->ro_rt->rt_ifp == (struct ifnet *)0) { struct sockaddr_in6 *sa6; /* No route yet, so try to acquire one */ bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); sa6 = (struct sockaddr_in6 *)&ro->ro_dst; sa6->sin6_family = AF_INET6; sa6->sin6_len = sizeof(struct sockaddr_in6); sa6->sin6_addr = *dst; sa6->sin6_scope_id = dstsock->sin6_scope_id; if (IN6_IS_ADDR_MULTICAST(dst)) { ro->ro_rt = rtalloc1(&((struct route *)ro) ->ro_dst, 0); } else { rtalloc((struct route *)ro); } } /* * in_pcbconnect() checks out IFF_LOOPBACK to skip using * the address. But we don't know why it does so. * It is necessary to ensure the scope even for lo0 * so doesn't check out IFF_LOOPBACK. */ if (ro->ro_rt) { ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); if (ia6 == 0) /* xxx scope error ?*/ ia6 = ifatoia6(ro->ro_rt->rt_ifa); } #if 0 /* * xxx The followings are necessary? (kazu) * I don't think so. * It's for SO_DONTROUTE option in IPv4.(jinmei) */ if (ia6 == 0) { struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; sin6->sin6_addr = *dst; ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); if (ia6 == 0) ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); if (ia6 == 0) return (0); return (&satosin6(&ia6->ia_addr)->sin6_addr); } #endif /* 0 */ if (ia6 == 0) { *errorp = EHOSTUNREACH; /* no route */ return (0); } return (&satosin6(&ia6->ia_addr)->sin6_addr); } *errorp = EADDRNOTAVAIL; return (0); } /* * Default hop limit selection. The precedence is as follows: * 1. Hoplimit value specified via ioctl. * 2. (If the outgoing interface is detected) the current * hop limit of the interface specified by router advertisement. * 3. The system default hoplimit. */ #define in6pcb inpcb #define in6p_hops inp_hops int in6_selecthlim(in6p, ifp) struct in6pcb *in6p; struct ifnet *ifp; { if (in6p && in6p->in6p_hops >= 0) return (in6p->in6p_hops); else if (ifp) return (ND_IFINFO(ifp)->chlim); else return (ip6_defhlim); } #undef in6pcb #undef in6p_hops /* * generate kernel-internal form (scopeid embedded into s6_addr16[1]). * If the address scope of is link-local, embed the interface index in the * address. The routine determines our precedence * between advanced API scope/interface specification and basic API * specification. * * this function should be nuked in the future, when we get rid of * embedded scopeid thing. * * XXX actually, it is over-specification to return ifp against sin6_scope_id. * there can be multiple interfaces that belong to a particular scope zone * (in specification, we have 1:N mapping between a scope zone and interfaces). * we may want to change the function to return something other than ifp. */ int in6_embedscope(in6, sin6, in6p, ifpp) struct in6_addr *in6; const struct sockaddr_in6 *sin6; struct inpcb *in6p; #define in6p_outputopts inp_outputopts6 #define in6p_moptions inp_moptions6 struct ifnet **ifpp; { struct ifnet *ifp = NULL; u_int32_t scopeid; *in6 = sin6->sin6_addr; scopeid = sin6->sin6_scope_id; if (ifpp) *ifpp = NULL; /* * don't try to read sin6->sin6_addr beyond here, since the caller may * ask us to overwrite existing sockaddr_in6 */ if (IN6_IS_SCOPE_LINKLOCAL(in6)) { struct in6_pktinfo *pi; /* * KAME assumption: link id == interface id */ if (in6p && in6p->in6p_outputopts && (pi = in6p->in6p_outputopts->ip6po_pktinfo) && pi->ipi6_ifindex) { ifp = ifindex2ifnet[pi->ipi6_ifindex]; in6->s6_addr16[1] = htons(pi->ipi6_ifindex); } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && in6p->in6p_moptions && in6p->in6p_moptions->im6o_multicast_ifp) { ifp = in6p->in6p_moptions->im6o_multicast_ifp; in6->s6_addr16[1] = htons(ifp->if_index); } else if (scopeid) { /* boundary check */ if (scopeid < 0 || if_index < scopeid) return ENXIO; /* XXX EINVAL? */ ifp = ifindex2ifnet[scopeid]; /*XXX assignment to 16bit from 32bit variable */ in6->s6_addr16[1] = htons(scopeid & 0xffff); } if (ifpp) *ifpp = ifp; } return 0; } #undef in6p_outputopts #undef in6p_moptions /* * generate standard sockaddr_in6 from embedded form. * touches sin6_addr and sin6_scope_id only. * * this function should be nuked in the future, when we get rid of * embedded scopeid thing. */ int in6_recoverscope(sin6, in6, ifp) struct sockaddr_in6 *sin6; const struct in6_addr *in6; struct ifnet *ifp; { u_int32_t scopeid; sin6->sin6_addr = *in6; /* * don't try to read *in6 beyond here, since the caller may * ask us to overwrite existing sockaddr_in6 */ sin6->sin6_scope_id = 0; if (IN6_IS_SCOPE_LINKLOCAL(in6)) { /* * KAME assumption: link id == interface id */ scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); if (scopeid) { /* sanity check */ if (scopeid < 0 || if_index < scopeid) return ENXIO; if (ifp && ifp->if_index != scopeid) return ENXIO; sin6->sin6_addr.s6_addr16[1] = 0; sin6->sin6_scope_id = scopeid; } } return 0; } /* * just clear the embedded scope identifer. */ void in6_clearscope(addr) struct in6_addr *addr; { if (IN6_IS_SCOPE_LINKLOCAL(addr)) addr->s6_addr16[1] = 0; }