/* $KAME: in6_src.c,v 1.159 2005/10/19 01:40:32 t-momose 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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 __KERNEL_RCSID(0, "$NetBSD: in6_src.c,v 1.36 2007/03/04 06:03:26 christos Exp $"); #include "opt_inet.h" #include #include #include #include #include #include #include #ifndef __FreeBSD__ #include #else #include #endif #ifdef __FreeBSD__ #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef __OpenBSD__ #include #endif #include #include #include #include #ifdef MIP6 #include #include #include "mip.h" #if NMIP > 0 #include #endif /* NMIP > 0 */ #endif /* MIP6 */ #ifndef __OpenBSD__ #include "loop.h" #endif #ifdef __NetBSD__ extern struct ifnet loif[NLOOP]; #endif #define ADDR_LABEL_NOTAPP (-1) struct in6_addrpolicy defaultaddrpolicy; #ifdef notyet /* until introducing ND extensions and address selection */ int ip6_prefer_tempaddr = 0; #endif static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *, struct ip6_moptions *, struct route *, struct ifnet **, struct rtentry **, int, int); static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, struct ip6_moptions *, struct route *, struct ifnet **); static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *); static void init_policy_queue(void); static int add_addrsel_policyent(struct in6_addrpolicy *); static int delete_addrsel_policyent(struct in6_addrpolicy *); static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *), void *); static int dump_addrsel_policyent(struct in6_addrpolicy *, void *); static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *); /* * 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. */ #if 0 /* diabled ad-hoc */ #define REPLACE(r) do {\ if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ ip6stat.ip6s_sources_rule[(r)]++; \ /* printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \ goto replace; \ } while(0) #define NEXT(r) do {\ if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ ip6stat.ip6s_sources_rule[(r)]++; \ /* printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \ goto next; /* XXX: we can't use 'continue' here */ \ } while(0) #define BREAK(r) do { \ if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ ip6stat.ip6s_sources_rule[(r)]++; \ goto out; /* XXX: we can't use 'break' here */ \ } while(0) #else #define REPLACE(r) goto replace #define NEXT(r) goto next #define BREAK(r) goto out #endif struct in6_addr * in6_selectsrc(dstsock, opts, mopts, ro, laddr, ifpp, errorp) struct sockaddr_in6 *dstsock; struct ip6_pktopts *opts; struct ip6_moptions *mopts; struct route *ro; struct in6_addr *laddr; struct ifnet **ifpp; int *errorp; { struct in6_addr dst; struct ifnet *ifp = NULL; struct in6_ifaddr *ia = NULL, *ia_best = NULL; struct in6_pktinfo *pi = NULL; int dst_scope = -1, best_scope = -1, best_matchlen = -1; struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL; u_int32_t odstzone; int error; #ifdef notyet /* until introducing ND extensions and address selection */ int prefer_tempaddr; #endif #if defined(MIP6) && NMIP > 0 u_int8_t ip6po_usecoa = 0; #endif /* MIP6 && NMIP > 0 */ dst = dstsock->sin6_addr; /* make a copy for local operation */ *errorp = 0; if (ifpp) *ifpp = NULL; /* * Try to determine the outgoing interface for the given destination. * We do this regardless of whether the socket is bound, since the * caller may need this information as a side effect of the call * to this function (e.g., for identifying the appropriate scope zone * ID). */ error = in6_selectif(dstsock, opts, mopts, ro, &ifp); if (ifpp) *ifpp = ifp; /* * If the source address is explicitly specified by the caller, * check if the requested source address is indeed a unicast address * assigned to the node, and can be used as the packet's source * address. If everything is okay, use the address as source. */ if (opts && (pi = opts->ip6po_pktinfo) && !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { struct sockaddr_in6 srcsock; struct in6_ifaddr *ia6; /* * Determine the appropriate zone id of the source based on * the zone of the destination and the outgoing interface. * If the specified address is ambiguous wrt the scope zone, * the interface must be specified; otherwise, ifa_ifwithaddr() * will fail matching the address. */ bzero(&srcsock, sizeof(srcsock)); srcsock.sin6_family = AF_INET6; srcsock.sin6_len = sizeof(srcsock); srcsock.sin6_addr = pi->ipi6_addr; if (ifp) { *errorp = in6_setscope(&srcsock.sin6_addr, ifp, NULL); if (*errorp != 0) return (NULL); } ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)(&srcsock)); if (ia6 == NULL || (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) { *errorp = EADDRNOTAVAIL; return (NULL); } pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */ if (ifpp) *ifpp = ifp; return (&ia6->ia_addr.sin6_addr); } /* * If the socket has already bound the source, just use it. We don't * care at the moment whether in6_selectif() succeeded above, even * though it would eventually cause an error. */ if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) return (laddr); /* * The outgoing interface is crucial in the general selection procedure * below. If it is not known at this point, we fail. */ if (ifp == NULL) { *errorp = error; return (NULL); } /* * If the address is not yet determined, choose the best one based on * the outgoing interface and the destination address. */ #if defined(MIP6) && NMIP > 0 /* * a caller can specify IP6PO_USECOA to not to use a home * address. for example, the case that the neighbour * unreachability detection to the global address. */ if (opts != NULL && (opts->ip6po_flags & IP6PO_USECOA) != 0) { ip6po_usecoa = 1; } #endif /* MIP6 && NMIP > 0 */ #ifdef DIAGNOSTIC if (ifp == NULL) /* this should not happen */ panic("in6_selectsrc: NULL ifp"); #endif *errorp = in6_setscope(&dst, ifp, &odstzone); if (*errorp != 0) return (NULL); for (ia = in6_ifaddr; ia; ia = ia->ia_next) { int new_scope = -1, new_matchlen = -1; struct in6_addrpolicy *new_policy = NULL; u_int32_t srczone, osrczone, dstzone; struct in6_addr src; struct ifnet *ifp1 = ia->ia_ifp; /* * We'll never take an address that breaks the scope zone * of the destination. We also skip an address if its zone * does not contain the outgoing interface. * XXX: we should probably use sin6_scope_id here. */ if (in6_setscope(&dst, ifp1, &dstzone) || odstzone != dstzone) { continue; } src = ia->ia_addr.sin6_addr; if (in6_setscope(&src, ifp, &osrczone) || in6_setscope(&src, ifp1, &srczone) || osrczone != srczone) { continue; } /* avoid unusable addresses */ if ((ia->ia6_flags & (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) { continue; } if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia)) continue; #if defined(MIP6) && NMIP > 0 /* avoid unusable home addresses. */ if ((ia->ia6_flags & IN6_IFF_HOME) && !mip6_ifa6_is_addr_valid_hoa(ia)) continue; #endif /* MIP6 && NMIP > 0 */ /* Rule 1: Prefer same address */ if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) { ia_best = ia; BREAK(1); /* there should be no better candidate */ } if (ia_best == NULL) REPLACE(0); /* Rule 2: Prefer appropriate scope */ if (dst_scope < 0) dst_scope = in6_addrscope(&dst); new_scope = in6_addrscope(&ia->ia_addr.sin6_addr); if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) { if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) REPLACE(2); NEXT(2); } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) { if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) NEXT(2); REPLACE(2); } /* * Rule 3: Avoid deprecated addresses. Note that the case of * !ip6_use_deprecated is already rejected above. */ if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia)) NEXT(3); if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia)) REPLACE(3); /* Rule 4: Prefer home addresses */ #if defined(MIP6) && NMIP > 0 if (!MIP6_IS_MN) goto skip_rule4; if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 && (ia->ia6_flags & IN6_IFF_HOME) == 0) { /* both address are not home addresses. */ goto skip_rule4; } /* * If SA is simultaneously a home address and care-of * address and SB is not, then prefer SA. Similarly, * if SB is simultaneously a home address and care-of * address and SA is not, then prefer SB. */ if (((ia_best->ia6_flags & IN6_IFF_HOME) != 0 && ia_best->ia_ifp->if_type != IFT_MIP) && ((ia->ia6_flags & IN6_IFF_HOME) != 0 && ia->ia_ifp->if_type == IFT_MIP)) NEXT(4); if (((ia_best->ia6_flags & IN6_IFF_HOME) != 0 && ia_best->ia_ifp->if_type == IFT_MIP) && ((ia->ia6_flags & IN6_IFF_HOME) != 0 && ia->ia_ifp->if_type != IFT_MIP)) REPLACE(4); if (ip6po_usecoa == 0) { /* * If SA is just a home address and SB is just * a care-of address, then prefer * SA. Similarly, if SB is just a home address * and SA is just a care-of address, then * prefer SB. */ if ((ia_best->ia6_flags & IN6_IFF_HOME) != 0 && (ia->ia6_flags & IN6_IFF_HOME) == 0) { NEXT(4); } if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 && (ia->ia6_flags & IN6_IFF_HOME) != 0) { REPLACE(4); } } else { /* * a sender don't want to use a home address * because: * * 1) we cannot use. (ex. NS or NA to global * addresses.) * * 2) a user specified not to use. * (ex. mip6control -u) */ if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 && (ia->ia6_flags & IN6_IFF_HOME) != 0) { /* XXX breaks stat */ NEXT(0); } if ((ia_best->ia6_flags & IN6_IFF_HOME) != 0 && (ia->ia6_flags & IN6_IFF_HOME) == 0) { /* XXX breaks stat */ REPLACE(0); } } skip_rule4: #endif /* MIP6 && NMIP > 0 */ /* Rule 5: Prefer outgoing interface */ if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) NEXT(5); if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) REPLACE(5); /* * Rule 6: Prefer matching label * Note that best_policy should be non-NULL here. */ if (dst_policy == NULL) dst_policy = lookup_addrsel_policy(dstsock); if (dst_policy->label != ADDR_LABEL_NOTAPP) { new_policy = lookup_addrsel_policy(&ia->ia_addr); if (dst_policy->label == best_policy->label && dst_policy->label != new_policy->label) NEXT(6); if (dst_policy->label != best_policy->label && dst_policy->label == new_policy->label) REPLACE(6); } /* * Rule 7: Prefer public addresses. * We allow users to reverse the logic by configuring * a sysctl variable, so that privacy conscious users can * always prefer temporary addresses. */ #ifdef notyet /* until introducing ND extensions and address selection */ if (opts == NULL || opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) { prefer_tempaddr = ip6_prefer_tempaddr; } else if (opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_NOTPREFER) { prefer_tempaddr = 0; } else prefer_tempaddr = 1; if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) && (ia->ia6_flags & IN6_IFF_TEMPORARY)) { if (prefer_tempaddr) REPLACE(7); else NEXT(7); } if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) && !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { if (prefer_tempaddr) NEXT(7); else REPLACE(7); } #endif /* * Rule 8: prefer addresses on alive interfaces. * This is a KAME specific rule. */ if ((ia_best->ia_ifp->if_flags & IFF_UP) && !(ia->ia_ifp->if_flags & IFF_UP)) NEXT(8); if (!(ia_best->ia_ifp->if_flags & IFF_UP) && (ia->ia_ifp->if_flags & IFF_UP)) REPLACE(8); /* * Rule 9: prefer addresses on "preferred" interfaces. * This is a KAME specific rule. */ #ifdef notyet /* until introducing address selection */ #define NDI_BEST ND_IFINFO(ia_best->ia_ifp) #define NDI_NEW ND_IFINFO(ia->ia_ifp) if ((NDI_BEST->flags & ND6_IFF_PREFER_SOURCE) && !(NDI_NEW->flags & ND6_IFF_PREFER_SOURCE)) NEXT(9); if (!(NDI_BEST->flags & ND6_IFF_PREFER_SOURCE) && (NDI_NEW->flags & ND6_IFF_PREFER_SOURCE)) REPLACE(9); #undef NDI_BEST #undef NDI_NEW #endif /* * Rule 14: Use longest matching prefix. * Note: in the address selection draft, this rule is * documented as "Rule 8". However, since it is also * documented that this rule can be overridden, we assign * a large number so that it is easy to assign smaller numbers * to more preferred rules. */ new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst); if (best_matchlen < new_matchlen) REPLACE(14); if (new_matchlen < best_matchlen) NEXT(14); /* Rule 15 is reserved. */ /* * Last resort: just keep the current candidate. * Or, do we need more rules? */ continue; replace: ia_best = ia; best_scope = (new_scope >= 0 ? new_scope : in6_addrscope(&ia_best->ia_addr.sin6_addr)); best_policy = (new_policy ? new_policy : lookup_addrsel_policy(&ia_best->ia_addr)); best_matchlen = (new_matchlen >= 0 ? new_matchlen : in6_matchlen(&ia_best->ia_addr.sin6_addr, &dst)); next: continue; out: break; } if ((ia = ia_best) == NULL) { *errorp = EADDRNOTAVAIL; return (NULL); } return (&ia->ia_addr.sin6_addr); } #undef REPLACE #undef BREAK #undef NEXT static int selectroute(dstsock, opts, mopts, ro, retifp, retrt, clone, norouteok) struct sockaddr_in6 *dstsock; struct ip6_pktopts *opts; struct ip6_moptions *mopts; struct route *ro; struct ifnet **retifp; struct rtentry **retrt; int clone; int norouteok; { int error = 0; struct ifnet *ifp = NULL; struct rtentry *rt = NULL; struct sockaddr_in6 *sin6_next; struct in6_pktinfo *pi = NULL; struct in6_addr *dst; dst = &dstsock->sin6_addr; #if 0 if (dstsock->sin6_addr.s6_addr32[0] == 0 && dstsock->sin6_addr.s6_addr32[1] == 0 && !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { printf("in6_selectroute: strange destination %s\n", ip6_sprintf(&dstsock->sin6_addr)); } else { printf("in6_selectroute: destination = %s%%%d\n", ip6_sprintf(&dstsock->sin6_addr), dstsock->sin6_scope_id); /* for debug */ } #endif /* If the caller specify the outgoing interface explicitly, use it. */ if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { /* XXX boundary check is assumed to be already done. */ #ifdef __FreeBSD__ ifp = ifnet_byindex(pi->ipi6_ifindex); #else ifp = ifindex2ifnet[pi->ipi6_ifindex]; #endif if (ifp != NULL && (norouteok || retrt == NULL || IN6_IS_ADDR_MULTICAST(dst))) { /* * we do not have to check or get the route for * multicast. */ goto done; } else goto getroute; } /* * If the destination address is a multicast address and the outgoing * interface for the address is specified by the caller, use it. */ if (IN6_IS_ADDR_MULTICAST(dst) && mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { goto done; /* we do not need a route for multicast. */ } getroute: /* * If the next hop address for the packet is specified by the caller, * use it as the gateway. */ if (opts && opts->ip6po_nexthop) { struct route *ron; sin6_next = satosin6(opts->ip6po_nexthop); /* at this moment, we only support AF_INET6 next hops */ if (sin6_next->sin6_family != AF_INET6) { error = EAFNOSUPPORT; /* or should we proceed? */ goto done; } /* * If the next hop is an IPv6 address, then the node identified * by that address must be a neighbor of the sending host. */ ron = (struct route *)&opts->ip6po_nextroute; if (!IN6_ARE_ADDR_EQUAL( &satocsin6(rtcache_getdst(ron))->sin6_addr, &sin6_next->sin6_addr)) rtcache_free(ron); else rtcache_check(ron); if (ron->ro_rt == NULL) { *satosin6(&ron->ro_dst) = *sin6_next; rtcache_init(ron); } if (ron->ro_rt == NULL || (ron->ro_rt->rt_flags & RTF_GATEWAY) != 0 || !nd6_is_addr_neighbor(sin6_next, ron->ro_rt->rt_ifp)) { rtcache_free(ron); error = EHOSTUNREACH; goto done; } rt = ron->ro_rt; ifp = rt->rt_ifp; /* * When cloning is required, try to allocate a route to the * destination so that the caller can store path MTU * information. */ if (!clone) goto done; } /* * Use a cached route if it exists and is valid, else try to allocate * a new one. Note that we should check the address family of the * cached destination, in case of sharing the cache with IPv4. */ if (ro != NULL) { if (rtcache_getdst(ro)->sa_family != AF_INET6 || !IN6_ARE_ADDR_EQUAL(&satocsin6(rtcache_getdst(ro))->sin6_addr, dst)) rtcache_free(ro); else rtcache_check(ro); if (ro->ro_rt == NULL) { struct sockaddr_in6 *sa6; /* No route yet, so try to acquire one */ sa6 = satosin6(&ro->ro_dst); *sa6 = *dstsock; sa6->sin6_scope_id = 0; if (clone) rtcache_init(ro); else rtcache_init_noclone(ro); } /* * do not care about the result if we have the nexthop * explicitly specified. */ if (opts && opts->ip6po_nexthop) goto done; if (ro->ro_rt == NULL) error = EHOSTUNREACH; else ifp = ro->ro_rt->rt_ifp; rt = ro->ro_rt; /* * Check if the outgoing interface conflicts with * the interface specified by ipi6_ifindex (if specified). * Note that loopback interface is always okay. * (this may happen when we are sending a packet to one of * our own addresses.) */ if (opts && opts->ip6po_pktinfo && opts->ip6po_pktinfo->ipi6_ifindex) { if (!(ifp->if_flags & IFF_LOOPBACK) && ifp->if_index != opts->ip6po_pktinfo->ipi6_ifindex) { error = EHOSTUNREACH; goto done; } } } done: if (ifp == NULL && rt == NULL) { /* * This can happen if the caller did not pass a cached route * nor any other hints. We treat this case an error. */ error = EHOSTUNREACH; } if (error == EHOSTUNREACH) ip6stat.ip6s_noroute++; if (retifp != NULL) *retifp = ifp; if (retrt != NULL) *retrt = rt; /* rt may be NULL */ return (error); } static int in6_selectif(dstsock, opts, mopts, ro, retifp) struct sockaddr_in6 *dstsock; struct ip6_pktopts *opts; struct ip6_moptions *mopts; struct route *ro; struct ifnet **retifp; { int error, clone; struct rtentry *rt = NULL; clone = IN6_IS_ADDR_MULTICAST(&dstsock->sin6_addr) ? 0 : 1; if ((error = selectroute(dstsock, opts, mopts, ro, retifp, &rt, clone, 1)) != 0) { return (error); } /* * do not use a rejected or black hole route. * XXX: this check should be done in the L2 output routine. * However, if we skipped this check here, we'd see the following * scenario: * - install a rejected route for a scoped address prefix * (like fe80::/10) * - send a packet to a destination that matches the scoped prefix, * with ambiguity about the scope zone. * - pick the outgoing interface from the route, and disambiguate the * scope zone with the interface. * - ip6_output() would try to get another route with the "new" * destination, which may be valid. * - we'd see no error on output. * Although this may not be very harmful, it should still be confusing. * We thus reject the case here. */ if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); /* * Adjust the "outgoing" interface. If we're going to loop the packet * back to ourselves, the ifp would be the loopback interface. * However, we'd rather know the interface associated to the * destination address (which should probably be one of our own * addresses.) */ if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) *retifp = rt->rt_ifa->ifa_ifp; return (0); } int in6_selectroute(dstsock, opts, mopts, ro, retifp, retrt, clone) struct sockaddr_in6 *dstsock; struct ip6_pktopts *opts; struct ip6_moptions *mopts; struct route *ro; struct ifnet **retifp; struct rtentry **retrt; int clone; /* meaningful only for bsdi and freebsd. */ { return selectroute(dstsock, opts, mopts, ro, retifp, retrt, clone, 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. */ 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); } /* * Find an empty port and set it to the specified PCB. */ int in6_pcbsetport(laddr, in6p, l) struct in6_addr *laddr; struct in6pcb *in6p; struct lwp *l; { struct socket *so = in6p->in6p_socket; struct inpcbtable *table = in6p->in6p_table; int cnt; u_int16_t minport, maxport; u_int16_t lport, *lastport; int wild = 0; void *t; /* XXX: this is redundant when called from in6_pcbbind */ if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 && ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 || (so->so_options & SO_ACCEPTCONN) == 0)) wild = 1; if (in6p->in6p_flags & IN6P_LOWPORT) { #ifndef IPNOPRIVPORTS if (l == 0 || (kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, NULL) != 0)) return (EACCES); #endif minport = ip6_lowportmin; maxport = ip6_lowportmax; lastport = &table->inpt_lastlow; } else { minport = ip6_anonportmin; maxport = ip6_anonportmax; lastport = &table->inpt_lastport; } if (minport > maxport) { /* sanity check */ u_int16_t swp; swp = minport; minport = maxport; maxport = swp; } lport = *lastport - 1; for (cnt = maxport - minport + 1; cnt; cnt--, lport--) { if (lport < minport || lport > maxport) lport = maxport; #ifdef INET if (IN6_IS_ADDR_V4MAPPED(laddr)) { t = in_pcblookup_port(table, *(struct in_addr *)&laddr->s6_addr32[3], lport, wild); } else #endif { t = in6_pcblookup_port(table, laddr, lport, wild); } if (t == 0) goto found; } return (EAGAIN); found: in6p->in6p_flags |= IN6P_ANONPORT; *lastport = lport; in6p->in6p_lport = htons(lport); in6_pcbstate(in6p, IN6P_BOUND); return (0); /* success */ } void addrsel_policy_init() { init_policy_queue(); /* initialize the "last resort" policy */ bzero(&defaultaddrpolicy, sizeof(defaultaddrpolicy)); defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; } static struct in6_addrpolicy * lookup_addrsel_policy(key) struct sockaddr_in6 *key; { struct in6_addrpolicy *match = NULL; match = match_addrsel_policy(key); if (match == NULL) match = &defaultaddrpolicy; else match->use++; return (match); } /* * Subroutines to manage the address selection policy table via sysctl. */ struct walkarg { size_t w_total; size_t w_given; void * w_where; void *w_limit; }; int in6_src_sysctl(void *oldp, size_t *oldlenp, void *newp, size_t newlen) { int error = 0; int s; s = splsoftnet(); if (newp) { error = EPERM; goto end; } if (oldp && oldlenp == NULL) { error = EINVAL; goto end; } if (oldp || oldlenp) { struct walkarg w; size_t oldlen = *oldlenp; memset(&w, 0, sizeof(w)); w.w_given = oldlen; w.w_where = oldp; if (oldp) w.w_limit = (char *)oldp + oldlen; error = walk_addrsel_policy(dump_addrsel_policyent, &w); *oldlenp = w.w_total; if (oldp && w.w_total > oldlen && error == 0) error = ENOMEM; } end: splx(s); return (error); } int in6_src_ioctl(cmd, data) u_long cmd; void *data; { int i; struct in6_addrpolicy ent0; if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) return (EOPNOTSUPP); /* check for safety */ ent0 = *(struct in6_addrpolicy *)data; if (ent0.label == ADDR_LABEL_NOTAPP) return (EINVAL); /* check if the prefix mask is consecutive. */ if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) return (EINVAL); /* clear trailing garbages (if any) of the prefix address. */ for (i = 0; i < 4; i++) { ent0.addr.sin6_addr.s6_addr32[i] &= ent0.addrmask.sin6_addr.s6_addr32[i]; } ent0.use = 0; switch (cmd) { case SIOCAADDRCTL_POLICY: return (add_addrsel_policyent(&ent0)); case SIOCDADDRCTL_POLICY: return (delete_addrsel_policyent(&ent0)); } return (0); /* XXX: compromise compilers */ } /* * The followings are implementation of the policy table using a * simple tail queue. * XXX such details should be hidden. * XXX implementation using binary tree should be more efficient. */ struct addrsel_policyent { TAILQ_ENTRY(addrsel_policyent) ape_entry; struct in6_addrpolicy ape_policy; }; TAILQ_HEAD(addrsel_policyhead, addrsel_policyent); struct addrsel_policyhead addrsel_policytab; static void init_policy_queue() { TAILQ_INIT(&addrsel_policytab); } static int add_addrsel_policyent(newpolicy) struct in6_addrpolicy *newpolicy; { struct addrsel_policyent *new, *pol; /* duplication check */ for (pol = TAILQ_FIRST(&addrsel_policytab); pol; pol = TAILQ_NEXT(pol, ape_entry)) { if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr, &pol->ape_policy.addr.sin6_addr) && IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr, &pol->ape_policy.addrmask.sin6_addr)) { return (EEXIST); /* or override it? */ } } MALLOC(new, struct addrsel_policyent *, sizeof(*new), M_IFADDR, M_WAITOK); bzero(new, sizeof(*new)); /* XXX: should validate entry */ new->ape_policy = *newpolicy; TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry); return (0); } static int delete_addrsel_policyent(key) struct in6_addrpolicy *key; { struct addrsel_policyent *pol; /* search for the entry in the table */ for (pol = TAILQ_FIRST(&addrsel_policytab); pol; pol = TAILQ_NEXT(pol, ape_entry)) { if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr, &pol->ape_policy.addr.sin6_addr) && IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr, &pol->ape_policy.addrmask.sin6_addr)) { break; } } if (pol == NULL) { return (ESRCH); } TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry); return (0); } static int walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w) { struct addrsel_policyent *pol; int error = 0; TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) { if ((error = (*callback)(&pol->ape_policy, w)) != 0) return error; } return error; } static int dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg) { int error = 0; struct walkarg *w = arg; if (w->w_where && (char *)w->w_where + sizeof(*pol) <= (char *)w->w_limit) { if ((error = copyout(pol, w->w_where, sizeof(*pol))) != 0) return error; w->w_where = (char *)w->w_where + sizeof(*pol); } w->w_total += sizeof(*pol); return error; } static struct in6_addrpolicy * match_addrsel_policy(key) struct sockaddr_in6 *key; { struct addrsel_policyent *pent; struct in6_addrpolicy *bestpol = NULL, *pol; int matchlen, bestmatchlen = -1; u_char *mp, *ep, *k, *p, m; for (pent = TAILQ_FIRST(&addrsel_policytab); pent; pent = TAILQ_NEXT(pent, ape_entry)) { matchlen = 0; pol = &pent->ape_policy; mp = (u_char *)&pol->addrmask.sin6_addr; ep = mp + 16; /* XXX: scope field? */ k = (u_char *)&key->sin6_addr; p = (u_char *)&pol->addr.sin6_addr; for (; mp < ep && *mp; mp++, k++, p++) { m = *mp; if ((*k & m) != *p) goto next; /* not match */ if (m == 0xff) /* short cut for a typical case */ matchlen += 8; else { while (m >= 0x80) { matchlen++; m <<= 1; } } } /* matched. check if this is better than the current best. */ if (bestpol == NULL || matchlen > bestmatchlen) { bestpol = pol; bestmatchlen = matchlen; } next: continue; } return (bestpol); }