/* $NetBSD: in6_src.c,v 1.79.6.4 2023/08/04 14:24:16 martin Exp $ */ /* $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 1.79.6.4 2023/08/04 14:24:16 martin Exp $"); #ifdef _KERNEL_OPT #include "opt_inet.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef MIP6 #include #include #include "mip.h" #if NMIP > 0 #include #endif /* NMIP > 0 */ #endif /* MIP6 */ #include #define ADDR_LABEL_NOTAPP (-1) struct in6_addrpolicy defaultaddrpolicy; int ip6_prefer_tempaddr = 0; static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, struct ip6_moptions *, struct route *, struct ifnet **, struct psref *); 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 *); #define IFA6_IS_VALIDATED(ia) \ (((ia)->ia6_flags & (IN6_IFF_TENTATIVE | IN6_IFF_DETACHED)) == 0) /* * 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 /* disabled ad-hoc */ #define REPLACE(r) do {\ char _buf1[INET6_ADDRSTRLEN], _buf2[INET6_ADDRSTRLEN]; \ if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ ip6stat.ip6s_sources_rule[(r)]++; \ printf("%s: replace %s with %s by %d\n", __func__, ia_best ? \ IN6_PRINT(_buf1, &ia_best->ia_addr.sin6_addr) : "none", \ IN6_PRINT(_buf2, &ia->ia_addr.sin6_addr), (r)); \ goto replace; \ } while(/*CONSTCOND*/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("%s: keep %s against %s by %d\n", ia_best ? \ IN6_PRINT(_buf1, &ia_best->ia_addr.sin6_addr) : "none", \ IN6_PRINT(_buf2, &ia->ia_addr.sin6_addr), (r)); \ goto next; /* XXX: we can't use 'continue' here */ \ } while(/*CONSTCOND*/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(/*CONSTCOND*/0) #else #define REPLACE(r) goto replace #define NEXT(r) goto next #define BREAK(r) goto out #endif /* * Called inside pserialize critical section. Don't sleep/block. */ static struct in6_ifaddr * in6_select_best_ia(struct sockaddr_in6 *dstsock, struct in6_addr *dst, const struct ifnet *ifp, const struct ip6_pktopts *opts, const u_int32_t odstzone) { struct in6_ifaddr *ia, *ia_best = NULL; int dst_scope = -1, best_scope = -1, best_matchlen = -1; struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL; IN6_ADDRLIST_READER_FOREACH(ia) { 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; int prefer_tempaddr; /* * 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_DUPLICATED | IN6_IFF_ANYCAST))) 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(1); /* 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. * Treat unvalidated addresses as deprecated here. */ if (IFA6_IS_VALIDATED(ia_best) && !IFA6_IS_VALIDATED(ia)) NEXT(3); if (!IFA6_IS_VALIDATED(ia_best) && IFA6_IS_VALIDATED(ia)) REPLACE(3); 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. */ 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); } /* * 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; } return ia_best; } #undef REPLACE #undef BREAK #undef NEXT int in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, struct ip6_moptions *mopts, struct route *ro, struct in6_addr *laddr, struct ifnet **ifpp, struct psref *psref, struct in6_addr *ret_ia6) { struct in6_addr dst; struct ifnet *ifp = NULL; struct in6_ifaddr *ia = NULL; struct in6_pktinfo *pi = NULL; u_int32_t odstzone; int error = 0, iferror; #if defined(MIP6) && NMIP > 0 u_int8_t ip6po_usecoa = 0; #endif /* MIP6 && NMIP > 0 */ struct psref local_psref; int bound = curlwp_bind(); #define PSREF (psref == NULL) ? &local_psref : psref int s; KASSERT((ifpp != NULL && psref != NULL) || (ifpp == NULL && psref == NULL)); dst = dstsock->sin6_addr; /* make a copy for local operation */ 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). */ iferror = in6_selectif(dstsock, opts, mopts, ro, &ifp, PSREF); if (ifpp != NULL) *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; int _s; struct ifaddr *ifa; /* * 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. */ memset(&srcsock, 0, sizeof(srcsock)); srcsock.sin6_family = AF_INET6; srcsock.sin6_len = sizeof(srcsock); srcsock.sin6_addr = pi->ipi6_addr; if (ifp) { error = in6_setscope(&srcsock.sin6_addr, ifp, NULL); if (error != 0) goto exit; } _s = pserialize_read_enter(); ifa = ifa_ifwithaddr(sin6tosa(&srcsock)); if ((ia6 = ifatoia6(ifa)) == NULL || ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY)) { pserialize_read_exit(_s); error = EADDRNOTAVAIL; goto exit; } pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */ if (ifpp) *ifpp = ifp; *ret_ia6 = ia6->ia_addr.sin6_addr; pserialize_read_exit(_s); goto exit; } /* * 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)) { *ret_ia6 = *laddr; goto exit; } /* * The outgoing interface is crucial in the general selection procedure * below. If it is not known at this point, we fail. */ if (ifp == NULL) { error = iferror; goto exit; } /* * 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 */ error = in6_setscope(&dst, ifp, &odstzone); if (error != 0) goto exit; s = pserialize_read_enter(); ia = in6_select_best_ia(dstsock, &dst, ifp, opts, odstzone); if (ia == NULL) { pserialize_read_exit(s); error = EADDRNOTAVAIL; goto exit; } *ret_ia6 = ia->ia_addr.sin6_addr; pserialize_read_exit(s); exit: if (ifpp == NULL) if_put(ifp, PSREF); curlwp_bindx(bound); return error; #undef PSREF } int in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, struct route **ro, struct rtentry **retrt, bool count_discard) { int error = 0; struct rtentry *rt = NULL; union { struct sockaddr dst; struct sockaddr_in dst4; struct sockaddr_in6 dst6; } u; KASSERT(ro != NULL); KASSERT(*ro != NULL); KASSERT(retrt != NULL); #if 0 if (dstsock->sin6_addr.s6_addr32[0] == 0 && dstsock->sin6_addr.s6_addr32[1] == 0 && !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { char ip6buf[INET6_ADDRSTRLEN]; printf("in6_selectroute: strange destination %s\n", IN6_PRINT(ip6buf, &dstsock->sin6_addr)); } else { char ip6buf[INET6_ADDRSTRLEN]; printf("in6_selectroute: destination = %s%%%d\n", IN6_PRINT(ip6buf, &dstsock->sin6_addr), dstsock->sin6_scope_id); /* for debug */ } #endif /* * 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; struct sockaddr_in6 *sin6_next; 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 = &opts->ip6po_nextroute; rt = rtcache_lookup(ron, sin6tosa(sin6_next)); if (rt == NULL || (rt->rt_flags & RTF_GATEWAY) != 0 || !nd6_is_addr_neighbor(sin6_next, rt->rt_ifp)) { if (rt != NULL) { if (count_discard) in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); rtcache_unref(rt, ron); rt = NULL; } rtcache_free(ron); error = EHOSTUNREACH; goto done; } *ro = ron; 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. * * for V4 mapped addresses we want to pick up the v4 route * see PR kern/56348 */ if (IN6_IS_ADDR_V4MAPPED(&dstsock->sin6_addr)) { in6_sin6_2_sin(&u.dst4, dstsock); } else { u.dst6 = *dstsock; u.dst6.sin6_scope_id = 0; } rt = rtcache_lookup1(*ro, &u.dst, 1); if (rt == NULL) error = EHOSTUNREACH; /* * 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 (rt != NULL && !(rt->rt_ifp->if_flags & IFF_LOOPBACK) && rt->rt_ifp->if_index != opts->ip6po_pktinfo->ipi6_ifindex) { if (count_discard) in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); error = EHOSTUNREACH; rtcache_unref(rt, *ro); rt = NULL; } } done: if (error == EHOSTUNREACH) IP6_STATINC(IP6_STAT_NOROUTE); *retrt = rt; return error; } static int in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, struct ip6_moptions *mopts, struct route *ro, struct ifnet **retifp, struct psref *psref) { int error = 0; struct rtentry *rt = NULL; struct in6_addr *dst; struct in6_pktinfo *pi = NULL; KASSERT(retifp != NULL); *retifp = NULL; dst = &dstsock->sin6_addr; /* 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. */ *retifp = if_get_byindex(pi->ipi6_ifindex, psref); if (*retifp != NULL) return 0; 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) { *retifp = if_get_byindex(mopts->im6o_multicast_if_index, psref); if (*retifp != NULL) return 0; /* we do not need a route for multicast. */ } getroute: error = in6_selectroute(dstsock, opts, &ro, &rt, false); if (error != 0) return error; *retifp = if_get_byindex(rt->rt_ifp->if_index, psref); /* * 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_flags & (RTF_REJECT | RTF_BLACKHOLE))) { error = (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); /* XXX: ifp can be returned with psref even if error */ goto out; } /* * 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_ifa && rt->rt_ifa->ifa_ifp && rt->rt_ifa->ifa_ifp != *retifp && !if_is_deactivated(rt->rt_ifa->ifa_ifp)) { if_put(*retifp, psref); *retifp = rt->rt_ifa->ifa_ifp; if_acquire(*retifp, psref); } out: rtcache_unref(rt, ro); return error; } /* * 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(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); } int in6_selecthlim_rt(struct in6pcb *in6p) { struct rtentry *rt; if (in6p == NULL) return in6_selecthlim(in6p, NULL); rt = rtcache_validate(&in6p->in6p_route); if (rt != NULL) { int ret = in6_selecthlim(in6p, rt->rt_ifp); rtcache_unref(rt, &in6p->in6p_route); return ret; } else return in6_selecthlim(in6p, NULL); } /* * Find an empty port and set it to the specified PCB. */ int in6_pcbsetport(struct sockaddr_in6 *sin6, struct in6pcb *in6p, struct lwp *l) { struct socket *so = in6p->in6p_socket; struct inpcbtable *table = in6p->in6p_table; u_int16_t lport, *lastport; enum kauth_network_req req; int error = 0; if (in6p->in6p_flags & IN6P_LOWPORT) { #ifndef IPNOPRIVPORTS req = KAUTH_REQ_NETWORK_BIND_PRIVPORT; #else req = KAUTH_REQ_NETWORK_BIND_PORT; #endif lastport = &table->inpt_lastlow; } else { req = KAUTH_REQ_NETWORK_BIND_PORT; lastport = &table->inpt_lastport; } /* XXX-kauth: KAUTH_REQ_NETWORK_BIND_AUTOASSIGN_{,PRIV}PORT */ error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_BIND, req, so, sin6, NULL); if (error) return (EACCES); /* * Use RFC6056 randomized port selection */ error = portalgo_randport(&lport, &in6p->in6p_head, l->l_cred); if (error) return error; in6p->in6p_flags |= IN6P_ANONPORT; *lastport = lport; in6p->in6p_lport = htons(lport); in6_pcbstate(in6p, IN6P_BOUND); return (0); /* success */ } void addrsel_policy_init(void) { init_policy_queue(); /* initialize the "last resort" policy */ memset(&defaultaddrpolicy, 0, sizeof(defaultaddrpolicy)); defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; } static struct in6_addrpolicy * lookup_addrsel_policy(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 sel_walkarg { size_t w_total; size_t w_given; void * w_where; void *w_limit; }; int sysctl_net_inet6_addrctlpolicy(SYSCTLFN_ARGS); int sysctl_net_inet6_addrctlpolicy(SYSCTLFN_ARGS) { 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 sel_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(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(void) { TAILQ_INIT(&addrsel_policytab); } static int add_addrsel_policyent(struct in6_addrpolicy *newpolicy) { struct addrsel_policyent *newpol, *pol; /* duplication check */ TAILQ_FOREACH(pol, &addrsel_policytab, 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? */ } } newpol = malloc(sizeof(*newpol), M_IFADDR, M_WAITOK|M_ZERO); /* XXX: should validate entry */ newpol->ape_policy = *newpolicy; TAILQ_INSERT_TAIL(&addrsel_policytab, newpol, ape_entry); return (0); } static int delete_addrsel_policyent(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 sel_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(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); }