/* * Copyright (c) 2000-2022 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * 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 #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 #include #include "loop.h" SYSCTL_DECL(_net_inet6_ip6); static int ip6_select_srcif_debug = 0; SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_srcif_debug, CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_srcif_debug, 0, "log source interface selection debug info"); static int ip6_select_srcaddr_debug = 0; SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_srcaddr_debug, CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_srcaddr_debug, 0, "log source address selection debug info"); static int ip6_select_src_expensive_secondary_if = 0; SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_src_expensive_secondary_if, CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_src_expensive_secondary_if, 0, "allow source interface selection to use expensive secondaries"); static int ip6_select_src_strong_end = 1; SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_src_strong_end, CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_src_strong_end, 0, "limit source address selection to outgoing interface"); #define ADDR_LABEL_NOTAPP (-1) struct in6_addrpolicy defaultaddrpolicy; int ip6_prefer_tempaddr = 1; int ip6_cga_conflict_retries = IPV6_CGA_CONFLICT_RETRIES_DEFAULT; extern int udp_use_randomport; extern int tcp_use_randomport; static int selectroute(struct sockaddr_in6 *, struct sockaddr_in6 *, struct ip6_pktopts *, struct ip6_moptions *, struct in6_ifaddr **, struct route_in6 *, struct ifnet **, struct rtentry **, int, int, struct ip6_out_args *ip6oa); static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, struct ip6_moptions *, struct route_in6 *ro, struct ip6_out_args *, struct ifnet **); static void init_policy_queue(void); static int add_addrsel_policyent(const struct in6_addrpolicy *); static int walk_addrsel_policy(int (*)(const struct in6_addrpolicy *, void *), void *); static int dump_addrsel_policyent(const struct in6_addrpolicy *, void *); static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *); void addrsel_policy_init(void); #define SASEL_DO_DBG(inp) \ (ip6_select_srcaddr_debug && (inp) != NULL && \ (inp)->inp_socket != NULL && \ ((inp)->inp_socket->so_options & SO_DEBUG)) #define SASEL_LOG(fmt, ...) \ do { \ if (srcsel_debug) \ os_log(OS_LOG_DEFAULT, "%s:%d " fmt,\ __FUNCTION__, __LINE__, ##__VA_ARGS__); \ } while (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. */ #define REPLACE(r) do {\ SASEL_LOG("REPLACE r %s ia %s ifp1 %s\n", \ (#r), s_src, ifp1->if_xname); \ srcrule = (r); \ goto replace; \ } while (0) #define NEXTSRC(r) do {\ SASEL_LOG("NEXTSRC r %s ia %s ifp1 %s\n", \ (#r), s_src, ifp1->if_xname); \ goto next; /* XXX: we can't use 'continue' here */ \ } while (0) #define BREAK(r) do { \ SASEL_LOG("BREAK r %s ia %s ifp1 %s\n", \ (#r), s_src, ifp1->if_xname); \ srcrule = (r); \ goto out; /* XXX: we can't use 'break' here */ \ } while (0) struct ifaddr * in6_selectsrc_core_ifa(struct sockaddr_in6 *addr, struct ifnet *ifp, int srcsel_debug) { int err = 0; struct ifnet *src_ifp = NULL; struct in6_addr src_storage = {}; struct in6_addr *in6 = NULL; struct ifaddr *ifa = NULL; if ((in6 = in6_selectsrc_core(addr, (ip6_prefer_tempaddr ? IPV6_SRCSEL_HINT_PREFER_TMPADDR : 0), ifp, 0, &src_storage, &src_ifp, &err, &ifa, NULL)) == NULL) { if (err == 0) { err = EADDRNOTAVAIL; } VERIFY(src_ifp == NULL); if (ifa != NULL) { ifa_remref(ifa); ifa = NULL; } goto done; } if (src_ifp != ifp) { if (err == 0) { err = ENETUNREACH; } if (ifa != NULL) { ifa_remref(ifa); ifa = NULL; } goto done; } VERIFY(ifa != NULL); ifnet_lock_shared(ifp); if ((ifa->ifa_debug & IFD_DETACHING) != 0) { err = EHOSTUNREACH; ifnet_lock_done(ifp); ifa_remref(ifa); ifa = NULL; goto done; } ifnet_lock_done(ifp); done: SASEL_LOG("Returned with error: %d", err); if (src_ifp != NULL) { ifnet_release(src_ifp); } return ifa; } struct in6_addr * in6_selectsrc_core(struct sockaddr_in6 *dstsock, uint32_t hint_mask, struct ifnet *ifp, int srcsel_debug, struct in6_addr *src_storage, struct ifnet **sifp, int *errorp, struct ifaddr **ifapp, struct route_in6 *ro) { u_int32_t odstzone; int bestrule = IP6S_SRCRULE_0; struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL; struct in6_addr dst; struct in6_ifaddr *ia = NULL, *ia_best = NULL; char s_src[MAX_IPv6_STR_LEN] = {0}; char s_dst[MAX_IPv6_STR_LEN] = {0}; const struct in6_addr *tmp = NULL; int dst_scope = -1, best_scope = -1, best_matchlen = -1; uint64_t secs = net_uptime(); struct nd_defrouter *dr = NULL; uint32_t genid = in6_ifaddrlist_genid; VERIFY(dstsock != NULL); VERIFY(src_storage != NULL); VERIFY(ifp != NULL); if (sifp != NULL) { *sifp = NULL; } if (ifapp != NULL) { *ifapp = NULL; } dst = dstsock->sin6_addr; /* make a copy for local operation */ if (srcsel_debug) { (void) inet_ntop(AF_INET6, &dst, s_dst, sizeof(s_src)); tmp = &in6addr_any; (void) inet_ntop(AF_INET6, tmp, s_src, sizeof(s_src)); os_log(OS_LOG_DEFAULT, "%s out src %s dst %s ifp %s", __func__, s_src, s_dst, ifp->if_xname); } *errorp = in6_setscope(&dst, ifp, &odstzone); if (*errorp != 0) { src_storage = NULL; goto done; } /* * Determine if the route is an indirect here * and if it is get the default router that would be * used as next hop. * Later in the function it is used to apply rule 5.5 of RFC 6724. */ if (ro != NULL && ro->ro_rt != NULL && (ro->ro_rt->rt_flags & RTF_GATEWAY) && ro->ro_rt->rt_gateway != NULL) { struct rtentry *rt = ro->ro_rt; lck_mtx_lock(nd6_mutex); dr = defrouter_lookup(NULL, &SIN6(rt->rt_gateway)->sin6_addr, rt->rt_ifp); lck_mtx_unlock(nd6_mutex); } lck_rw_lock_shared(&in6_ifaddr_rwlock); addrloop: TAILQ_FOREACH(ia, &in6_ifaddrhead, ia6_link) { int new_scope = -1, new_matchlen = -1; struct in6_addrpolicy *new_policy = NULL; u_int32_t srczone = 0, osrczone, dstzone; struct in6_addr src; struct ifnet *ifp1 = ia->ia_ifp; int srcrule; if (srcsel_debug) { (void) inet_ntop(AF_INET6, &ia->ia_addr.sin6_addr, s_src, sizeof(s_src)); } IFA_LOCK(&ia->ia_ifa); /* * Simply skip addresses reserved for CLAT46 */ if (ia->ia6_flags & IN6_IFF_CLAT46) { SASEL_LOG("NEXT ia %s address on ifp1 %s skipped as it is " "reserved for CLAT46\n", s_src, ifp1->if_xname); goto next; } /* * XXX By default we are strong end system and will * limit candidate set of source address to the ones * configured on the outgoing interface. */ if (ip6_select_src_strong_end && ifp1 != ifp) { SASEL_LOG("NEXT ia %s ifp1 %s address is not on outgoing " "interface \n", s_src, ifp1->if_xname); goto next; } /* * 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) { SASEL_LOG("NEXT ia %s ifp1 %s odstzone %d != dstzone %d\n", s_src, ifp1->if_xname, odstzone, dstzone); goto next; } src = ia->ia_addr.sin6_addr; if (in6_setscope(&src, ifp, &osrczone) || in6_setscope(&src, ifp1, &srczone) || osrczone != srczone) { SASEL_LOG("NEXT ia %s ifp1 %s osrczone %d != srczone %d\n", s_src, ifp1->if_xname, osrczone, srczone); goto next; } /* avoid unusable addresses */ if ((ia->ia6_flags & (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) { SASEL_LOG("NEXT ia %s ifp1 %s ia6_flags 0x%x\n", s_src, ifp1->if_xname, ia->ia6_flags); goto next; } if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia, secs)) { SASEL_LOG("NEXT ia %s ifp1 %s IFA6_IS_DEPRECATED\n", s_src, ifp1->if_xname); goto next; } if (!nd6_optimistic_dad && (ia->ia6_flags & IN6_IFF_OPTIMISTIC) != 0) { SASEL_LOG("NEXT ia %s ifp1 %s IN6_IFF_OPTIMISTIC\n", s_src, ifp1->if_xname); goto next; } /* Rule 1: Prefer same address */ if (in6_are_addr_equal_scoped(&dst, &ia->ia_addr.sin6_addr, dstzone, srczone)) { BREAK(IP6S_SRCRULE_1); /* there should be no better candidate */ } if (ia_best == NULL) { REPLACE(IP6S_SRCRULE_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(IP6S_SRCRULE_2); } NEXTSRC(IP6S_SRCRULE_2); } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) { if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) { NEXTSRC(IP6S_SRCRULE_2); } REPLACE(IP6S_SRCRULE_2); } /* * Rule 3: Avoid deprecated addresses. Note that the case of * !ip6_use_deprecated is already rejected above. */ if (!IFA6_IS_DEPRECATED(ia_best, secs) && IFA6_IS_DEPRECATED(ia, secs)) { NEXTSRC(IP6S_SRCRULE_3); } if (IFA6_IS_DEPRECATED(ia_best, secs) && !IFA6_IS_DEPRECATED(ia, secs)) { REPLACE(IP6S_SRCRULE_3); } /* * RFC 4429 says that optimistic addresses are equivalent to * deprecated addresses, so avoid them here. */ if ((ia_best->ia6_flags & IN6_IFF_OPTIMISTIC) == 0 && (ia->ia6_flags & IN6_IFF_OPTIMISTIC) != 0) { NEXTSRC(IP6S_SRCRULE_3); } if ((ia_best->ia6_flags & IN6_IFF_OPTIMISTIC) != 0 && (ia->ia6_flags & IN6_IFF_OPTIMISTIC) == 0) { REPLACE(IP6S_SRCRULE_3); } /* Rule 4: Prefer home addresses */ /* * XXX: This is a TODO. We should probably merge the MIP6 * case above. */ /* Rule 5: Prefer outgoing interface */ /* * XXX By default we are strong end with source address * selection. That means all address selection candidate * addresses will be the ones hosted on the outgoing interface * making the following check redundant. */ if (ip6_select_src_strong_end == 0) { if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) { NEXTSRC(IP6S_SRCRULE_5); } if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) { REPLACE(IP6S_SRCRULE_5); } } /* * Rule 5.5: Prefer addresses in a prefix advertised by the next-hop. * If SA or SA's prefix is assigned by the selected next-hop that will * be used to send to D and SB or SB's prefix is assigned by a different * next-hop, then prefer SA. Similarly, if SB or SB's prefix is * assigned by the next-hop that will be used to send to D and SA or * SA's prefix is assigned by a different next-hop, then prefer SB. */ if (dr != NULL && ia_best->ia6_ndpr != ia->ia6_ndpr) { boolean_t ia_best_has_prefix = FALSE; boolean_t ia_has_prefix = FALSE; struct nd_prefix ia_best_prefix = {}; struct nd_prefix ia_prefix = {}; struct nd_prefix *p_ia_best_prefix = NULL; struct nd_prefix *p_ia_prefix = NULL; if (ia_best->ia6_ndpr) { ia_best_prefix = *ia_best->ia6_ndpr; } if (ia->ia6_ndpr) { ia_prefix = *ia->ia6_ndpr; } IFA_UNLOCK(&ia->ia_ifa); lck_rw_done(&in6_ifaddr_rwlock); p_ia_best_prefix = nd6_prefix_lookup(&ia_best_prefix, ND6_PREFIX_EXPIRY_UNSPEC); p_ia_prefix = nd6_prefix_lookup(&ia_prefix, ND6_PREFIX_EXPIRY_UNSPEC); lck_mtx_lock(nd6_mutex); if (p_ia_best_prefix != NULL) { NDPR_LOCK(p_ia_best_prefix); ia_best_has_prefix = (pfxrtr_lookup(p_ia_best_prefix, dr) != NULL); NDPR_UNLOCK(p_ia_best_prefix); NDPR_REMREF(p_ia_best_prefix); } if (p_ia_prefix != NULL) { NDPR_LOCK(p_ia_prefix); ia_has_prefix = (pfxrtr_lookup(p_ia_prefix, dr) != NULL); NDPR_UNLOCK(p_ia_prefix); NDPR_REMREF(p_ia_prefix); } lck_mtx_unlock(nd6_mutex); lck_rw_lock_shared(&in6_ifaddr_rwlock); if (genid != os_atomic_load(&in6_ifaddrlist_genid, acquire)) { SASEL_LOG("Address list seems to have changed. Restarting source " "address selection.\n"); genid = in6_ifaddrlist_genid; /* * We are starting from scratch. Free up the reference * on ia_best and also reset it to NULL. */ ifa_remref(&ia_best->ia_ifa); ia_best = NULL; goto addrloop; } IFA_LOCK(&ia->ia_ifa); if (ia_best_has_prefix && !ia_has_prefix) { NEXTSRC(IP6S_SRCRULE_5_5); } if (!ia_best_has_prefix && ia_has_prefix) { REPLACE(IP6S_SRCRULE_5_5); } } /* * Rule 6: Prefer matching label * Note that best_policy should be non-NULL here. */ if (dst_policy == NULL) { dst_policy = in6_addrsel_lookup_policy(dstsock); } if (dst_policy->label != ADDR_LABEL_NOTAPP) { new_policy = in6_addrsel_lookup_policy(&ia->ia_addr); if (dst_policy->label == best_policy->label && dst_policy->label != new_policy->label) { NEXTSRC(IP6S_SRCRULE_6); } if (dst_policy->label != best_policy->label && dst_policy->label == new_policy->label) { REPLACE(IP6S_SRCRULE_6); } } /* * Rule 7: Prefer temporary addresses. * We allow users to reverse the logic by configuring * a sysctl variable, so that transparency conscious users can * always prefer stable addresses. */ if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) && (ia->ia6_flags & IN6_IFF_TEMPORARY)) { if (hint_mask & IPV6_SRCSEL_HINT_PREFER_TMPADDR) { REPLACE(IP6S_SRCRULE_7); } else { NEXTSRC(IP6S_SRCRULE_7); } } if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) && !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { if (hint_mask & IPV6_SRCSEL_HINT_PREFER_TMPADDR) { NEXTSRC(IP6S_SRCRULE_7); } else { REPLACE(IP6S_SRCRULE_7); } } /* * Rule 7x: 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)) { NEXTSRC(IP6S_SRCRULE_7x); } if (!(ia_best->ia_ifp->if_flags & IFF_UP) && (ia->ia_ifp->if_flags & IFF_UP)) { REPLACE(IP6S_SRCRULE_7x); } /* * Rule 8: Use longest matching prefix. */ new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst); if (best_matchlen < new_matchlen) { REPLACE(IP6S_SRCRULE_8); } if (new_matchlen < best_matchlen) { NEXTSRC(IP6S_SRCRULE_8); } /* * Last resort: just keep the current candidate. * Or, do we need more rules? */ if (ifp1 != ifp && (ifp1->if_eflags & IFEF_EXPENSIVE) && ip6_select_src_expensive_secondary_if == 0) { SASEL_LOG("NEXT ia %s ifp1 %s IFEF_EXPENSIVE\n", s_src, ifp1->if_xname); ip6stat.ip6s_sources_skip_expensive_secondary_if++; goto next; } SASEL_LOG("NEXT ia %s ifp1 %s last resort\n", s_src, ifp1->if_xname); IFA_UNLOCK(&ia->ia_ifa); continue; replace: /* * Ignore addresses on secondary interfaces that are marked * expensive */ if (ifp1 != ifp && (ifp1->if_eflags & IFEF_EXPENSIVE) && ip6_select_src_expensive_secondary_if == 0) { SASEL_LOG("NEXT ia %s ifp1 %s IFEF_EXPENSIVE\n", s_src, ifp1->if_xname); ip6stat.ip6s_sources_skip_expensive_secondary_if++; goto next; } bestrule = srcrule; best_scope = (new_scope >= 0 ? new_scope : in6_addrscope(&ia->ia_addr.sin6_addr)); best_policy = (new_policy ? new_policy : in6_addrsel_lookup_policy(&ia->ia_addr)); best_matchlen = (new_matchlen >= 0 ? new_matchlen : in6_matchlen(&ia->ia_addr.sin6_addr, &dst)); SASEL_LOG("NEXT ia %s ifp1 %s best_scope %d new_scope %d dst_scope %d\n", s_src, ifp1->if_xname, best_scope, new_scope, dst_scope); ifa_addref(&ia->ia_ifa); /* for ia_best */ IFA_UNLOCK(&ia->ia_ifa); if (ia_best != NULL) { ifa_remref(&ia_best->ia_ifa); } ia_best = ia; continue; next: IFA_UNLOCK(&ia->ia_ifa); continue; out: ifa_addref(&ia->ia_ifa); /* for ia_best */ IFA_UNLOCK(&ia->ia_ifa); if (ia_best != NULL) { ifa_remref(&ia_best->ia_ifa); } ia_best = ia; break; } lck_rw_done(&in6_ifaddr_rwlock); if ((ia = ia_best) == NULL) { if (*errorp == 0) { *errorp = EADDRNOTAVAIL; } src_storage = NULL; goto done; } if (sifp != NULL) { *sifp = ia->ia_ifa.ifa_ifp; ifnet_reference(*sifp); } IFA_LOCK_SPIN(&ia->ia_ifa); if (bestrule < IP6S_SRCRULE_COUNT) { ip6stat.ip6s_sources_rule[bestrule]++; } *src_storage = satosin6(&ia->ia_addr)->sin6_addr; IFA_UNLOCK(&ia->ia_ifa); if (ifapp != NULL) { *ifapp = &ia->ia_ifa; } else { ifa_remref(&ia->ia_ifa); } done: if (srcsel_debug) { (void) inet_ntop(AF_INET6, &dst, s_dst, sizeof(s_src)); tmp = (src_storage != NULL) ? src_storage : &in6addr_any; (void) inet_ntop(AF_INET6, tmp, s_src, sizeof(s_src)); os_log(OS_LOG_DEFAULT, "%s out src %s dst %s dst_scope %d best_scope %d", __func__, s_src, s_dst, dst_scope, best_scope); } if (dr != NULL) { NDDR_REMREF(dr); } return src_storage; } /* * Regardless of error, it will return an ifp with a reference held if the * caller provides a non-NULL ifpp. The caller is responsible for checking * if the returned ifp is valid and release its reference at all times. */ struct in6_addr * in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, struct inpcb *inp, struct route_in6 *ro, struct ifnet **ifpp, struct in6_addr *src_storage, unsigned int ifscope, int *errorp) { struct ifnet *ifp = NULL; struct in6_pktinfo *pi = NULL; struct ip6_moptions *mopts; struct ip6_out_args ip6oa; boolean_t inp_debug = FALSE; uint32_t hint_mask = 0; int prefer_tempaddr = 0; struct ifnet *sifp = NULL; bzero(&ip6oa, sizeof(ip6oa)); ip6oa.ip6oa_boundif = ifscope; ip6oa.ip6oa_flags = IP6OAF_SELECT_SRCIF; ip6oa.ip6oa_sotc = SO_TC_UNSPEC; ip6oa.ip6oa_netsvctype = _NET_SERVICE_TYPE_UNSPEC; *errorp = 0; if (ifpp != NULL) { *ifpp = NULL; } if (inp != NULL) { inp_debug = SASEL_DO_DBG(inp); mopts = inp->in6p_moptions; if (INP_NO_CELLULAR(inp)) { ip6oa.ip6oa_flags |= IP6OAF_NO_CELLULAR; } if (INP_NO_EXPENSIVE(inp)) { ip6oa.ip6oa_flags |= IP6OAF_NO_EXPENSIVE; } if (INP_NO_CONSTRAINED(inp)) { ip6oa.ip6oa_flags |= IP6OAF_NO_CONSTRAINED; } if (INP_AWDL_UNRESTRICTED(inp)) { ip6oa.ip6oa_flags |= IP6OAF_AWDL_UNRESTRICTED; } if (INP_INTCOPROC_ALLOWED(inp)) { ip6oa.ip6oa_flags |= IP6OAF_INTCOPROC_ALLOWED; } if (INP_MANAGEMENT_ALLOWED(inp)) { ip6oa.ip6oa_flags |= IP6OAF_MANAGEMENT_ALLOWED; } } else { mopts = NULL; /* Allow the kernel to retransmit packets. */ ip6oa.ip6oa_flags |= IP6OAF_INTCOPROC_ALLOWED | IP6OAF_AWDL_UNRESTRICTED | IP6OAF_MANAGEMENT_ALLOWED; } if (ip6oa.ip6oa_boundif != IFSCOPE_NONE) { ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF; } /* * 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; /* get the outgoing interface */ if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ip6oa, &ifp)) != 0) { src_storage = NULL; goto done; } /* * 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. */ SOCKADDR_ZERO(&srcsock, sizeof(srcsock)); srcsock.sin6_family = AF_INET6; srcsock.sin6_len = sizeof(srcsock); srcsock.sin6_addr = pi->ipi6_addr; if (ifp != NULL) { *errorp = in6_setscope(&srcsock.sin6_addr, ifp, IN6_NULL_IF_EMBEDDED_SCOPE(&srcsock.sin6_scope_id)); if (*errorp != 0) { src_storage = NULL; goto done; } } ia6 = (struct in6_ifaddr *)ifa_ifwithaddr(SA(&srcsock)); if (ia6 == NULL) { *errorp = EADDRNOTAVAIL; src_storage = NULL; goto done; } IFA_LOCK_SPIN(&ia6->ia_ifa); if ((ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY | IN6_IFF_CLAT46)) || (inp && inp_restricted_send(inp, ia6->ia_ifa.ifa_ifp))) { IFA_UNLOCK(&ia6->ia_ifa); ifa_remref(&ia6->ia_ifa); *errorp = EHOSTUNREACH; src_storage = NULL; goto done; } *src_storage = satosin6(&ia6->ia_addr)->sin6_addr; IFA_UNLOCK(&ia6->ia_ifa); ifa_remref(&ia6->ia_ifa); goto done; } /* * Otherwise, if the socket has already bound the source, just use it. */ if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) { src_storage = &inp->in6p_laddr; goto done; } /* * If the address is not specified, choose the best one based on * the outgoing interface and the destination address. */ /* get the outgoing interface */ if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ip6oa, &ifp)) != 0) { src_storage = NULL; goto done; } VERIFY(ifp != NULL); 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 (prefer_tempaddr) { hint_mask |= IPV6_SRCSEL_HINT_PREFER_TMPADDR; } if (in6_selectsrc_core(dstsock, hint_mask, ifp, inp_debug, src_storage, &sifp, errorp, NULL, ro) == NULL) { src_storage = NULL; goto done; } VERIFY(sifp != NULL); if (inp && inp_restricted_send(inp, sifp)) { src_storage = NULL; *errorp = EHOSTUNREACH; ifnet_release(sifp); goto done; } else { ifnet_release(sifp); } done: if (ifpp != NULL) { /* if ifp is non-NULL, refcnt held in in6_selectif() */ *ifpp = ifp; } else if (ifp != NULL) { ifnet_release(ifp); } return src_storage; } /* * Given a source IPv6 address (and route, if available), determine the best * interface to send the packet from. Checking for (and updating) the * ROF_SRCIF_SELECTED flag in the pcb-supplied route placeholder is done * without any locks, based on the assumption that in the event this is * called from ip6_output(), the output operation is single-threaded per-pcb, * i.e. for any given pcb there can only be one thread performing output at * the IPv6 layer. * * This routine is analogous to in_selectsrcif() for IPv4. Regardless of * error, it will return an ifp with a reference held if the caller provides * a non-NULL retifp. The caller is responsible for checking if the * returned ifp is valid and release its reference at all times. * * clone - meaningful only for bsdi and freebsd */ static int selectroute(struct sockaddr_in6 *srcsock, struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, struct ip6_moptions *mopts, struct in6_ifaddr **retsrcia, struct route_in6 *ro, struct ifnet **retifp, struct rtentry **retrt, int clone, int norouteok, struct ip6_out_args *ip6oa) { int error = 0; struct ifnet *ifp = NULL, *ifp0 = NULL; struct route_in6 *route = NULL; struct sockaddr_in6 *sin6_next; struct in6_pktinfo *pi = NULL; struct in6_addr *dst = &dstsock->sin6_addr; struct ifaddr *ifa = NULL; char s_src[MAX_IPv6_STR_LEN], s_dst[MAX_IPv6_STR_LEN]; boolean_t select_srcif, proxied_ifa = FALSE, local_dst = FALSE; unsigned int ifscope = ((ip6oa != NULL) ? ip6oa->ip6oa_boundif : IFSCOPE_NONE); boolean_t is_direct = FALSE; if (retifp != NULL) { *retifp = NULL; } if (retrt != NULL) { *retrt = NULL; } if (ip6_select_srcif_debug) { struct in6_addr src; src = (srcsock != NULL) ? srcsock->sin6_addr : in6addr_any; (void) inet_ntop(AF_INET6, &src, s_src, sizeof(s_src)); (void) inet_ntop(AF_INET6, dst, s_dst, sizeof(s_dst)); } /* * If the destination address is UNSPECIFIED addr, bail out. */ if (IN6_IS_ADDR_UNSPECIFIED(dst)) { error = EHOSTUNREACH; goto done; } /* * Perform source interface selection if Scoped Routing * is enabled and a source address that isn't unspecified. */ select_srcif = (srcsock != NULL && !IN6_IS_ADDR_UNSPECIFIED(&srcsock->sin6_addr)); /* * For scoped routing, if interface scope is 0 or src/dst addr is linklocal * or dst addr is multicast, source interface selection should be performed even * if the destination is directly reachable. */ if (ifscope != IFSCOPE_NONE && !(srcsock != NULL && IN6_IS_ADDR_LINKLOCAL(&srcsock->sin6_addr)) && !IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_LINKLOCAL(dst)) { struct rtentry *temp_rt = NULL; lck_mtx_lock(rnh_lock); temp_rt = rt_lookup(TRUE, SA(dstsock), NULL, rt_tables[AF_INET6], ifscope); lck_mtx_unlock(rnh_lock); /* * If the destination is directly reachable, relax * the behavior around select_srcif, i.e. don't force * the packet to go out from the interface that is hosting * the source address. * It happens when we share v6 with NAT66 and want * the external interface's v6 address to be reachable * to the clients we are sharing v6 connectivity with * using NAT. */ if (temp_rt != NULL) { if ((temp_rt->rt_flags & RTF_GATEWAY) == 0) { select_srcif = FALSE; is_direct = TRUE; } rtfree(temp_rt); } } if (ip6_select_srcif_debug) { os_log(OS_LOG_DEFAULT, "%s src %s dst %s ifscope %d " "is_direct %d select_srcif %d", __func__, s_src, s_dst, ifscope, is_direct, select_srcif); } /* If the caller specified the outgoing interface explicitly, use it */ if (opts != NULL && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex != 0) { /* * If IPV6_PKTINFO takes precedence over IPV6_BOUND_IF. */ ifscope = pi->ipi6_ifindex; ifnet_head_lock_shared(); /* ifp may be NULL if detached or out of range */ ifp = ifp0 = ((ifscope <= if_index) ? ifindex2ifnet[ifscope] : NULL); ifnet_head_done(); if (norouteok || retrt == NULL || IN6_IS_ADDR_MC_LINKLOCAL(dst)) { /* * We do not have to check or get the route for * multicast. If the caller didn't ask/care for * the route and we have no interface to use, * it's an error. */ if (ifp == NULL) { error = EHOSTUNREACH; } goto done; } else { goto getsrcif; } } /* * 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) { IM6O_LOCK(mopts); ifp = ifp0 = mopts->im6o_multicast_ifp; if (ifp != NULL && IN6_IS_ADDR_MC_LINKLOCAL(dst)) { IM6O_UNLOCK(mopts); goto done; /* we don't need a route for link-local multicast */ } IM6O_UNLOCK(mopts); } getsrcif: /* * If the outgoing interface was not set via IPV6_BOUND_IF or * IPV6_PKTINFO, use the scope ID in the destination address. */ if (ifscope == IFSCOPE_NONE) { ifscope = dstsock->sin6_scope_id; } /* * Perform source interface selection; the source IPv6 address * must belong to one of the addresses of the interface used * by the route. For performance reasons, do this only if * there is no route, or if the routing table has changed, * or if we haven't done source interface selection on this * route (for this PCB instance) before. */ if (!select_srcif) { goto getroute; } else if (!ROUTE_UNUSABLE(ro) && ro->ro_srcia != NULL && (ro->ro_flags & ROF_SRCIF_SELECTED)) { if (ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK) { local_dst = TRUE; } ifa = ro->ro_srcia; ifa_addref(ifa); /* for caller */ goto getroute; } /* * Given the source IPv6 address, find a suitable source interface * to use for transmission; if a scope ID has been specified, * optimize the search by looking at the addresses only for that * interface. This is still suboptimal, however, as we need to * traverse the per-interface list. */ if (ifscope != IFSCOPE_NONE || (ro != NULL && ro->ro_rt != NULL)) { unsigned int scope = ifscope; struct ifnet *rt_ifp; rt_ifp = (ro->ro_rt != NULL) ? ro->ro_rt->rt_ifp : NULL; /* * If no scope is specified and the route is stale (pointing * to a defunct interface) use the current primary interface; * this happens when switching between interfaces configured * with the same IPv6 address. Otherwise pick up the scope * information from the route; the ULP may have looked up a * correct route and we just need to verify it here and mark * it with the ROF_SRCIF_SELECTED flag below. */ if (scope == IFSCOPE_NONE) { scope = rt_ifp->if_index; if (scope != get_primary_ifscope(AF_INET6) && ROUTE_UNUSABLE(ro)) { scope = get_primary_ifscope(AF_INET6); } } ifa = (struct ifaddr *) ifa_foraddr6_scoped(&srcsock->sin6_addr, scope); /* * If we are forwarding and proxying prefix(es), see if the * source address is one of ours and is a proxied address; * if so, use it. */ if (ifa == NULL && ip6_forwarding && nd6_prproxy) { ifa = (struct ifaddr *) ifa_foraddr6(&srcsock->sin6_addr); if (ifa != NULL && !(proxied_ifa = nd6_prproxy_ifaddr((struct in6_ifaddr *)ifa))) { ifa_remref(ifa); ifa = NULL; } } if (ip6_select_srcif_debug && ifa != NULL) { if (ro->ro_rt != NULL) { os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d->%d ifa_if %s " "ro_if %s", __func__, s_src, s_dst, ifscope, scope, if_name(ifa->ifa_ifp), if_name(rt_ifp)); } else { os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d->%d ifa_if %s", __func__, s_src, s_dst, ifscope, scope, if_name(ifa->ifa_ifp)); } } } /* * Slow path; search for an interface having the corresponding source * IPv6 address if the scope was not specified by the caller, and: * * 1) There currently isn't any route, or, * 2) The interface used by the route does not own that source * IPv6 address; in this case, the route will get blown away * and we'll do a more specific scoped search using the newly * found interface. */ if (ifa == NULL && ifscope == IFSCOPE_NONE) { struct ifaddr *ifadst; /* Check if the destination address is one of ours */ ifadst = (struct ifaddr *)ifa_foraddr6(&dstsock->sin6_addr); if (ifadst != NULL) { local_dst = TRUE; ifa_remref(ifadst); } ifa = (struct ifaddr *)ifa_foraddr6(&srcsock->sin6_addr); if (ip6_select_srcif_debug && ifa != NULL) { os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d ifa_if %s", __func__, s_src, s_dst, ifscope, if_name(ifa->ifa_ifp)); } else if (ip6_select_srcif_debug) { os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d ifa_if NULL", __func__, s_src, s_dst, ifscope); } } getroute: if (ifa != NULL && !proxied_ifa && !local_dst) { ifscope = ifa->ifa_ifp->if_index; } /* * If the next hop address for the packet is specified by the caller, * use it as the gateway. */ if (opts != NULL && opts->ip6po_nexthop != NULL) { struct route_in6 *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 = &opts->ip6po_nextroute; if (ron->ro_rt != NULL) { RT_LOCK(ron->ro_rt); } if (ROUTE_UNUSABLE(ron) || (ron->ro_rt != NULL && (!(ron->ro_rt->rt_flags & RTF_LLINFO) || (select_srcif && (ifa == NULL || (ifa->ifa_ifp != ron->ro_rt->rt_ifp && !proxied_ifa))))) || !in6_are_addr_equal_scoped(&satosin6(&ron->ro_dst)->sin6_addr, &sin6_next->sin6_addr, ron->ro_rt->rt_ifp->if_index, sin6_next->sin6_scope_id)) { if (ron->ro_rt != NULL) { RT_UNLOCK(ron->ro_rt); } ROUTE_RELEASE(ron); *satosin6(&ron->ro_dst) = *sin6_next; } if (ron->ro_rt == NULL) { rtalloc_scoped((struct route *)ron, ifscope); if (ron->ro_rt != NULL) { RT_LOCK(ron->ro_rt); } if (ROUTE_UNUSABLE(ron) || !(ron->ro_rt->rt_flags & RTF_LLINFO) || !in6_are_addr_equal_scoped(&satosin6(rt_key(ron->ro_rt))-> sin6_addr, &sin6_next->sin6_addr, ron->ro_rt->rt_ifp->if_index, sin6_next->sin6_scope_id)) { if (ron->ro_rt != NULL) { RT_UNLOCK(ron->ro_rt); } ROUTE_RELEASE(ron); error = EHOSTUNREACH; goto done; } } route = ron; ifp = ifp0 = ron->ro_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) { if (select_srcif) { /* Keep the route locked */ goto validateroute; } RT_UNLOCK(ron->ro_rt); goto done; } RT_UNLOCK(ron->ro_rt); } /* * 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) { goto done; } if (ro->ro_rt != NULL) { RT_LOCK_SPIN(ro->ro_rt); } if (ROUTE_UNUSABLE(ro) || (ro->ro_rt != NULL && (satosin6(&ro->ro_dst)->sin6_family != AF_INET6 || !in6_are_addr_equal_scoped(&satosin6(&ro->ro_dst)->sin6_addr, dst, ro->ro_rt->rt_ifp->if_index, dstsock->sin6_scope_id) || (select_srcif && (ifa == NULL || (ifa->ifa_ifp != ro->ro_rt->rt_ifp && !proxied_ifa)))))) { if (ro->ro_rt != NULL) { RT_UNLOCK(ro->ro_rt); } ROUTE_RELEASE(ro); } if (ro->ro_rt == NULL) { struct sockaddr_in6 *sa6; /* No route yet, so try to acquire one */ SOCKADDR_ZERO(&ro->ro_dst, sizeof(struct sockaddr_in6)); sa6 = SIN6(&ro->ro_dst); sa6->sin6_family = AF_INET6; sa6->sin6_len = sizeof(struct sockaddr_in6); sa6->sin6_addr = *dst; if (IN6_IS_ADDR_MC_LINKLOCAL(dst)) { ro->ro_rt = rtalloc1_scoped( SA(&((struct route *)ro)->ro_dst), 0, 0, ifscope); } else { rtalloc_scoped((struct route *)ro, ifscope); } if (ro->ro_rt != NULL) { RT_LOCK_SPIN(ro->ro_rt); } } /* * Do not care about the result if we have the nexthop * explicitly specified (in case we're asked to clone.) */ if (opts != NULL && opts->ip6po_nexthop != NULL) { if (ro->ro_rt != NULL) { RT_UNLOCK(ro->ro_rt); } goto done; } if (ro->ro_rt != NULL) { RT_LOCK_ASSERT_HELD(ro->ro_rt); ifp = ifp0 = ro->ro_rt->rt_ifp; } else { error = EHOSTUNREACH; } route = ro; validateroute: if (select_srcif) { boolean_t has_route = (route != NULL && route->ro_rt != NULL); boolean_t srcif_selected = FALSE; if (has_route) { RT_LOCK_ASSERT_HELD(route->ro_rt); } /* * If there is a non-loopback route with the wrong interface, * or if there is no interface configured with such an address, * blow it away. Except for local/loopback, we look for one * with a matching interface scope/index. */ if (has_route && (ifa == NULL || (ifa->ifa_ifp != ifp && ifp != lo_ifp) || !(route->ro_rt->rt_flags & RTF_UP))) { /* * If the destination address belongs to a proxied * prefix, relax the requirement and allow the packet * to come out of the proxy interface with the source * address of the real interface. */ if (ifa != NULL && proxied_ifa && (route->ro_rt->rt_flags & (RTF_UP | RTF_PROXY)) == (RTF_UP | RTF_PROXY)) { srcif_selected = TRUE; } else { if (ip6_select_srcif_debug) { if (ifa != NULL) { os_log(OS_LOG_DEFAULT, "%s->%s ifscope %d " "ro_if %s != ifa_if %s " "(cached route cleared)", s_src, s_dst, ifscope, if_name(ifp), if_name(ifa->ifa_ifp)); } else { os_log(OS_LOG_DEFAULT, "%s->%s ifscope %d " "ro_if %s (no ifa_if " "found)", s_src, s_dst, ifscope, if_name(ifp)); } } RT_UNLOCK(route->ro_rt); ROUTE_RELEASE(route); error = EHOSTUNREACH; /* Undo the settings done above */ route = NULL; ifp = NULL; /* ditch ifp; keep ifp0 */ has_route = FALSE; } } else if (has_route) { srcif_selected = TRUE; } if (srcif_selected) { VERIFY(has_route); if (ifa != route->ro_srcia || !(route->ro_flags & ROF_SRCIF_SELECTED)) { RT_CONVERT_LOCK(route->ro_rt); if (ifa != NULL) { ifa_addref(ifa); /* for route_in6 */ } if (route->ro_srcia != NULL) { ifa_remref(route->ro_srcia); } route->ro_srcia = ifa; route->ro_flags |= ROF_SRCIF_SELECTED; RT_GENID_SYNC(route->ro_rt); } RT_UNLOCK(route->ro_rt); } } else { if (ro->ro_rt != NULL) { RT_UNLOCK(ro->ro_rt); } if (ifp != NULL && opts != NULL && opts->ip6po_pktinfo != NULL && opts->ip6po_pktinfo->ipi6_ifindex != 0) { /* * 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 (!(ifp->if_flags & IFF_LOOPBACK) && ifp->if_index != opts->ip6po_pktinfo->ipi6_ifindex) { error = EHOSTUNREACH; goto done; } } } done: /* * Check for interface restrictions. */ #define CHECK_RESTRICTIONS(_ip6oa, _ifp) \ ((((_ip6oa)->ip6oa_flags & IP6OAF_NO_CELLULAR) && \ IFNET_IS_CELLULAR(_ifp)) || \ (((_ip6oa)->ip6oa_flags & IP6OAF_NO_EXPENSIVE) && \ IFNET_IS_EXPENSIVE(_ifp)) || \ (((_ip6oa)->ip6oa_flags & IP6OAF_NO_CONSTRAINED) && \ IFNET_IS_CONSTRAINED(_ifp)) || \ (!((_ip6oa)->ip6oa_flags & IP6OAF_INTCOPROC_ALLOWED) && \ IFNET_IS_INTCOPROC(_ifp)) || \ (!((_ip6oa)->ip6oa_flags & IP6OAF_AWDL_UNRESTRICTED) && \ IFNET_IS_AWDL_RESTRICTED(_ifp)) && \ (!((_ip6oa)->ip6oa_flags & IP6OAF_MANAGEMENT_ALLOWED) && \ IFNET_IS_MANAGEMENT(_ifp))) if (error == 0 && ip6oa != NULL && ((ifp && CHECK_RESTRICTIONS(ip6oa, ifp)) || (route && route->ro_rt && CHECK_RESTRICTIONS(ip6oa, route->ro_rt->rt_ifp)))) { if (route != NULL && route->ro_rt != NULL) { ROUTE_RELEASE(route); route = NULL; } ifp = NULL; /* ditch ifp; keep ifp0 */ error = EHOSTUNREACH; ip6oa->ip6oa_flags |= IP6OAF_R_IFDENIED; } #undef CHECK_RESTRICTIONS /* * If the interface is disabled for IPv6, then ENETDOWN error. */ if (error == 0 && ifp != NULL && (ifp->if_eflags & IFEF_IPV6_DISABLED)) { error = ENETDOWN; } if (ifp == NULL && (route == NULL || route->ro_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 || error == ENETDOWN) { ip6stat.ip6s_noroute++; } /* * We'll return ifp regardless of error, so pick it up from ifp0 * in case it was nullified above. Caller is responsible for * releasing the ifp if it is non-NULL. */ ifp = ifp0; if (retifp != NULL) { if (ifp != NULL) { ifnet_reference(ifp); /* for caller */ } *retifp = ifp; } if (retsrcia != NULL) { if (ifa != NULL) { ifa_addref(ifa); /* for caller */ } *retsrcia = (struct in6_ifaddr *)ifa; } if (error == 0) { if (retrt != NULL && route != NULL) { *retrt = route->ro_rt; /* ro_rt may be NULL */ } } if (ip6_select_srcif_debug) { os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d ifa_if %s ro_if %s (error=%d)", __func__, s_src, s_dst, ifscope, (ifa != NULL) ? if_name(ifa->ifa_ifp) : "NONE", (ifp != NULL) ? if_name(ifp) : "NONE", error); } if (ifa != NULL) { ifa_remref(ifa); } return error; } /* * Regardless of error, it will return an ifp with a reference held if the * caller provides a non-NULL retifp. The caller is responsible for checking * if the returned ifp is valid and release its reference at all times. */ int in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, struct ip6_moptions *mopts, struct route_in6 *ro, struct ip6_out_args *ip6oa, struct ifnet **retifp) { int err = 0; struct route_in6 sro; struct rtentry *rt = NULL; if (ro == NULL) { bzero(&sro, sizeof(sro)); ro = &sro; } if ((err = selectroute(NULL, dstsock, opts, mopts, NULL, ro, retifp, &rt, 0, 1, ip6oa)) != 0) { goto done; } /* * 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))) { err = ((rt->rt_flags & RTF_HOST) ? EHOSTUNREACH : ENETUNREACH); goto done; } /* * 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 != NULL && rt->rt_ifa != NULL && rt->rt_ifa->ifa_ifp != NULL && retifp != NULL) { ifnet_reference(rt->rt_ifa->ifa_ifp); if (*retifp != NULL) { ifnet_release(*retifp); } *retifp = rt->rt_ifa->ifa_ifp; } done: if (ro == &sro) { VERIFY(rt == NULL || rt == ro->ro_rt); ROUTE_RELEASE(ro); } /* * retifp might point to a valid ifp with a reference held; * caller is responsible for releasing it if non-NULL. */ return err; } /* * Regardless of error, it will return an ifp with a reference held if the * caller provides a non-NULL retifp. The caller is responsible for checking * if the returned ifp is valid and release its reference at all times. * * clone - meaningful only for bsdi and freebsd */ int in6_selectroute(struct sockaddr_in6 *srcsock, struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, struct ip6_moptions *mopts, struct in6_ifaddr **retsrcia, struct route_in6 *ro, struct ifnet **retifp, struct rtentry **retrt, int clone, struct ip6_out_args *ip6oa) { return selectroute(srcsock, dstsock, opts, mopts, retsrcia, ro, retifp, retrt, clone, 0, ip6oa); } /* * Default hop limit selection. The precedence is as follows: * 1. Hoplimit value specified via socket option. * 2. (If the outgoing interface is detected) the current * hop limit of the interface specified by router advertisement. * 3. The system default hoplimit. */ uint8_t in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp) { if (in6p && in6p->in6p_hops >= 0) { return (uint8_t)in6p->in6p_hops; } else if (NULL != ifp) { uint8_t chlim; struct nd_ifinfo *ndi = ND_IFINFO(ifp); if (ndi && ndi->initialized) { /* access chlim without lock, for performance */ chlim = ndi->chlim; } else { chlim = (uint8_t)ip6_defhlim; } return chlim; } return (uint8_t)ip6_defhlim; } /* * XXX: this is borrowed from in6_pcbbind(). If possible, we should * share this function by all *bsd*... */ int in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct proc *p, int locked) { struct socket *so = inp->inp_socket; uint16_t lport = 0, first, last, *lastport, rand_port; int count, error = 0, wild = 0; boolean_t counting_down; bool found, randomport; struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; kauth_cred_t cred; #if SKYWALK bool laddr_unspecified = IN6_IS_ADDR_UNSPECIFIED(laddr); #else #pragma unused(laddr) #endif if (!locked) { /* Make sure we don't run into a deadlock: 4052373 */ if (!lck_rw_try_lock_exclusive(&pcbinfo->ipi_lock)) { socket_unlock(inp->inp_socket, 0); lck_rw_lock_exclusive(&pcbinfo->ipi_lock); socket_lock(inp->inp_socket, 0); } /* * Check if a local port was assigned to the inp while * this thread was waiting for the pcbinfo lock */ if (inp->inp_lport != 0) { VERIFY(inp->inp_flags2 & INP2_INHASHLIST); lck_rw_done(&pcbinfo->ipi_lock); /* * It is not an error if another thread allocated * a port */ return 0; } } /* XXX: this is redundant when called from in6_pcbbind */ if ((so->so_options & (SO_REUSEADDR | SO_REUSEPORT)) == 0) { wild = INPLOOKUP_WILDCARD; } randomport = (so->so_flags & SOF_BINDRANDOMPORT) > 0 || (so->so_type == SOCK_STREAM ? tcp_use_randomport : udp_use_randomport) > 0; if (inp->inp_flags & INP_HIGHPORT) { first = (uint16_t)ipport_hifirstauto; /* sysctl */ last = (uint16_t)ipport_hilastauto; lastport = &pcbinfo->ipi_lasthi; } else if (inp->inp_flags & INP_LOWPORT) { cred = kauth_cred_proc_ref(p); error = priv_check_cred(cred, PRIV_NETINET_RESERVEDPORT, 0); kauth_cred_unref(&cred); if (error != 0) { if (!locked) { lck_rw_done(&pcbinfo->ipi_lock); } return error; } first = (uint16_t)ipport_lowfirstauto; /* 1023 */ last = (uint16_t)ipport_lowlastauto; /* 600 */ lastport = &pcbinfo->ipi_lastlow; } else { first = (uint16_t)ipport_firstauto; /* sysctl */ last = (uint16_t)ipport_lastauto; lastport = &pcbinfo->ipi_lastport; } if (first == last) { randomport = false; } /* * Simple check to ensure all ports are not used up causing * a deadlock here. */ found = false; if (first > last) { /* counting down */ if (randomport) { read_frandom(&rand_port, sizeof(rand_port)); *lastport = first - (rand_port % (first - last)); } count = first - last; counting_down = TRUE; } else { /* counting up */ if (randomport) { read_frandom(&rand_port, sizeof(rand_port)); *lastport = first + (rand_port % (first - last)); } count = last - first; counting_down = FALSE; } do { if (count-- < 0) { /* completely used? */ /* * Undo any address bind that may have * occurred above. */ inp->in6p_laddr = in6addr_any; inp->in6p_last_outifp = NULL; inp->inp_lifscope = IFSCOPE_NONE; #if SKYWALK if (NETNS_TOKEN_VALID(&inp->inp_netns_token)) { netns_set_ifnet(&inp->inp_netns_token, NULL); } #endif /* SKYWALK */ if (!locked) { lck_rw_done(&pcbinfo->ipi_lock); } return EAGAIN; } if (counting_down) { --*lastport; if (*lastport > first || *lastport < last) { *lastport = first; } } else { ++*lastport; if (*lastport < first || *lastport > last) { *lastport = first; } } lport = htons(*lastport); /* * Skip if this is a restricted port as we do not want to * restricted ports as ephemeral */ if (IS_RESTRICTED_IN_PORT(lport)) { continue; } found = (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr, lport, inp->inp_lifscope, wild) == NULL); #if SKYWALK if (found && (SOCK_PROTO(so) == IPPROTO_TCP || SOCK_PROTO(so) == IPPROTO_UDP) && !(inp->inp_flags2 & INP2_EXTERNAL_PORT)) { if (laddr_unspecified && (inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) { struct in_addr ip_zero = { .s_addr = 0 }; netns_release(&inp->inp_wildcard_netns_token); if (netns_reserve_in( &inp->inp_wildcard_netns_token, ip_zero, (uint8_t)SOCK_PROTO(so), lport, NETNS_BSD, NULL) != 0) { /* port in use in IPv4 namespace */ found = false; } } if (found && netns_reserve_in6(&inp->inp_netns_token, inp->in6p_laddr, (uint8_t)SOCK_PROTO(so), lport, NETNS_BSD, NULL) != 0) { netns_release(&inp->inp_wildcard_netns_token); found = false; } } #endif /* SKYWALK */ } while (!found); inp->inp_lport = lport; inp->inp_flags |= INP_ANONPORT; if (in_pcbinshash(inp, 1) != 0) { inp->in6p_laddr = in6addr_any; inp->in6p_last_outifp = NULL; inp->inp_lifscope = IFSCOPE_NONE; #if SKYWALK netns_release(&inp->inp_netns_token); #endif /* SKYWALK */ inp->inp_lport = 0; inp->inp_flags &= ~INP_ANONPORT; if (!locked) { lck_rw_done(&pcbinfo->ipi_lock); } return EAGAIN; } if (!locked) { lck_rw_done(&pcbinfo->ipi_lock); } return 0; } /* * 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); } void addrsel_policy_init(void) { /* * Default address selection policy based on RFC 6724. */ static const struct in6_addrpolicy defaddrsel[] = { /* Loopback -- prefix=::1/128, precedence=50, label=0 */ { .addr = { .sin6_family = AF_INET6, .sin6_addr = IN6ADDR_LOOPBACK_INIT, .sin6_len = sizeof(struct sockaddr_in6) }, .addrmask = { .sin6_family = AF_INET6, .sin6_addr = IN6MASK128, .sin6_len = sizeof(struct sockaddr_in6) }, .preced = 50, .label = 0 }, /* Unspecified -- prefix=::/0, precedence=40, label=1 */ { .addr = { .sin6_family = AF_INET6, .sin6_addr = IN6ADDR_ANY_INIT, .sin6_len = sizeof(struct sockaddr_in6) }, .addrmask = { .sin6_family = AF_INET6, .sin6_addr = IN6MASK0, .sin6_len = sizeof(struct sockaddr_in6) }, .preced = 40, .label = 1 }, /* IPv4 Mapped -- prefix=::ffff:0:0/96, precedence=35, label=4 */ { .addr = { .sin6_family = AF_INET6, .sin6_addr = IN6ADDR_V4MAPPED_INIT, .sin6_len = sizeof(struct sockaddr_in6) }, .addrmask = { .sin6_family = AF_INET6, .sin6_addr = IN6MASK96, .sin6_len = sizeof(struct sockaddr_in6) }, .preced = 35, .label = 4 }, /* 6to4 -- prefix=2002::/16, precedence=30, label=2 */ { .addr = { .sin6_family = AF_INET6, .sin6_addr = {{{ 0x20, 0x02 }}}, .sin6_len = sizeof(struct sockaddr_in6) }, .addrmask = { .sin6_family = AF_INET6, .sin6_addr = IN6MASK16, .sin6_len = sizeof(struct sockaddr_in6) }, .preced = 30, .label = 2 }, /* Teredo -- prefix=2001::/32, precedence=5, label=5 */ { .addr = { .sin6_family = AF_INET6, .sin6_addr = {{{ 0x20, 0x01 }}}, .sin6_len = sizeof(struct sockaddr_in6) }, .addrmask = { .sin6_family = AF_INET6, .sin6_addr = IN6MASK32, .sin6_len = sizeof(struct sockaddr_in6) }, .preced = 5, .label = 5 }, /* Unique Local (ULA) -- prefix=fc00::/7, precedence=3, label=13 */ { .addr = { .sin6_family = AF_INET6, .sin6_addr = {{{ 0xfc }}}, .sin6_len = sizeof(struct sockaddr_in6) }, .addrmask = { .sin6_family = AF_INET6, .sin6_addr = IN6MASK7, .sin6_len = sizeof(struct sockaddr_in6) }, .preced = 3, .label = 13 }, /* IPv4 Compatible -- prefix=::/96, precedence=1, label=3 */ { .addr = { .sin6_family = AF_INET6, .sin6_addr = IN6ADDR_ANY_INIT, .sin6_len = sizeof(struct sockaddr_in6) }, .addrmask = { .sin6_family = AF_INET6, .sin6_addr = IN6MASK96, .sin6_len = sizeof(struct sockaddr_in6) }, .preced = 1, .label = 3 }, /* Site-local (deprecated) -- prefix=fec0::/10, precedence=1, label=11 */ { .addr = { .sin6_family = AF_INET6, .sin6_addr = {{{ 0xfe, 0xc0 }}}, .sin6_len = sizeof(struct sockaddr_in6) }, .addrmask = { .sin6_family = AF_INET6, .sin6_addr = IN6MASK16, .sin6_len = sizeof(struct sockaddr_in6) }, .preced = 1, .label = 11 }, /* 6bone (deprecated) -- prefix=3ffe::/16, precedence=1, label=12 */ { .addr = { .sin6_family = AF_INET6, .sin6_addr = {{{ 0x3f, 0xfe }}}, .sin6_len = sizeof(struct sockaddr_in6) }, .addrmask = { .sin6_family = AF_INET6, .sin6_addr = IN6MASK16, .sin6_len = sizeof(struct sockaddr_in6) }, .preced = 1, .label = 12 }, }; int i; init_policy_queue(); /* initialize the "last resort" policy */ bzero(&defaultaddrpolicy, sizeof(defaultaddrpolicy)); defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; for (i = 0; i < sizeof(defaddrsel) / sizeof(defaddrsel[0]); i++) { add_addrsel_policyent(&defaddrsel[i]); } } struct in6_addrpolicy * in6_addrsel_lookup_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; } 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; TAILQ_FOREACH(pent, &addrsel_policytab, 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 = (u_char)(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; } static int add_addrsel_policyent(const struct in6_addrpolicy *newpolicy) { struct addrsel_policyent *new, *pol; new = kalloc_type(struct addrsel_policyent, Z_WAITOK | Z_ZERO); /* 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)) { kfree_type(struct addrsel_policyent, new); return EEXIST; /* or override it? */ } } /* XXX: should validate entry */ new->ape_policy = *newpolicy; TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry); return 0; } int walk_addrsel_policy(int (*callback)(const 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; } /* * Subroutines to manage the address selection policy table via sysctl. */ struct walkarg { struct sysctl_req *w_req; }; static int dump_addrsel_policyent(const struct in6_addrpolicy *pol, void *arg) { int error = 0; struct walkarg *w = arg; error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol)); return error; } static int in6_src_sysctl SYSCTL_HANDLER_ARGS { #pragma unused(oidp, arg1, arg2) struct walkarg w; if (req->newptr) { return EPERM; } bzero(&w, sizeof(w)); w.w_req = req; return walk_addrsel_policy(dump_addrsel_policyent, &w); } SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy, CTLFLAG_RD | CTLFLAG_LOCKED, in6_src_sysctl, ""); int in6_src_ioctl(u_long cmd, caddr_t data) { int i; struct in6_addrpolicy ent0; if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) { return EOPNOTSUPP; /* check for safety */ } bcopy(data, &ent0, sizeof(ent0)); 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 ENOTSUP; case SIOCDADDRCTL_POLICY: return ENOTSUP; } return 0; /* XXX: compromise compilers */ } /* * 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(struct in6_addr *in6, const struct sockaddr_in6 *sin6, struct in6pcb *in6p, struct ifnet **ifpp, struct ip6_pktopts *opt, uint32_t *ret_ifscope) { struct ifnet *ifp = NULL; u_int32_t scopeid; struct ip6_pktopts *optp = NULL; *in6 = sin6->sin6_addr; scopeid = sin6->sin6_scope_id; if (ifpp != NULL) { *ifpp = NULL; } /* * don't try to read sin6->sin6_addr beyond here, since the caller may * ask us to overwrite existing sockaddr_in6 */ #ifdef ENABLE_DEFAULT_SCOPE if (scopeid == 0) { scopeid = scope6_addr2default(in6); } #endif if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) { struct in6_pktinfo *pi; struct ifnet *im6o_multicast_ifp = NULL; if (in6p != NULL && IN6_IS_ADDR_MULTICAST(in6) && in6p->in6p_moptions != NULL) { IM6O_LOCK(in6p->in6p_moptions); im6o_multicast_ifp = in6p->in6p_moptions->im6o_multicast_ifp; IM6O_UNLOCK(in6p->in6p_moptions); } if (opt != NULL) { optp = opt; } else if (in6p != NULL) { optp = in6p->in6p_outputopts; } /* * KAME assumption: link id == interface id */ if (in6p != NULL && optp != NULL && (pi = optp->ip6po_pktinfo) != NULL && pi->ipi6_ifindex != 0) { /* ifp is needed here if only we're returning it */ if (ifpp != NULL) { ifnet_head_lock_shared(); ifp = ifindex2ifnet[pi->ipi6_ifindex]; ifnet_head_done(); } if (in6_embedded_scope) { in6->s6_addr16[1] = htons((uint16_t)pi->ipi6_ifindex); } if (ret_ifscope != NULL) { *ret_ifscope = pi->ipi6_ifindex; } } else if (in6p != NULL && IN6_IS_ADDR_MULTICAST(in6) && in6p->in6p_moptions != NULL && im6o_multicast_ifp != NULL) { ifp = im6o_multicast_ifp; if (in6_embedded_scope) { in6->s6_addr16[1] = htons(ifp->if_index); } if (ret_ifscope != NULL) { *ret_ifscope = ifp->if_index; } } else if (scopeid != 0) { /* * Since scopeid is unsigned, we only have to check it * against if_index (ifnet_head_lock not needed since * if_index is an ever-increasing integer.) */ if (!IF_INDEX_IN_RANGE(scopeid)) { return ENXIO; /* XXX EINVAL? */ } /* ifp is needed here only if we're returning it */ if (ifpp != NULL) { ifnet_head_lock_shared(); ifp = ifindex2ifnet[scopeid]; ifnet_head_done(); } if (in6_embedded_scope) { /* XXX assignment to 16bit from 32bit variable */ in6->s6_addr16[1] = htons(scopeid & 0xffff); } if (ret_ifscope != NULL) { *ret_ifscope = scopeid; } } if (ifpp != NULL) { if (ifp != NULL) { ifnet_reference(ifp); /* for caller */ } *ifpp = ifp; } } return 0; } /* * 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( struct sockaddr_in6 *sin6, const struct in6_addr *in6, struct ifnet *ifp) { u_int32_t scopeid; sin6->sin6_addr = *in6; if (!in6_embedded_scope) { if (ifp != NULL && IN6_IS_SCOPE_EMBED(in6)) { sin6->sin6_scope_id = ifp->if_index; } return 0; } /* * 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) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) { /* * KAME assumption: link id == interface id */ scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); if (scopeid) { /* * sanity check * * Since scopeid is unsigned, we only have to check it * against if_index */ if (!IF_INDEX_IN_RANGE(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; }