/* $FreeBSD$ */ /* $KAME: in6_src.c,v 1.132 2003/08/26 04:42:27 keiichi 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. * 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 "opt_inet.h" #include "opt_inet6.h" #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 static struct mtx addrsel_lock; #define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF) #define ADDRSEL_LOCK() mtx_lock(&addrsel_lock) #define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock) #define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED) #define ADDR_LABEL_NOTAPP (-1) struct in6_addrpolicy defaultaddrpolicy; int ip6_prefer_tempaddr = 0; static int selectroute __P((struct sockaddr_in6 *, struct ip6_pktopts *, struct ip6_moptions *, struct route_in6 *, struct ifnet **, struct rtentry **, int, int)); static int in6_selectif __P((struct sockaddr_in6 *, struct ip6_pktopts *, struct ip6_moptions *, struct route_in6 *ro, struct ifnet **)); static struct in6_addrpolicy *lookup_addrsel_policy __P((struct sockaddr_in6 *)); static void init_policy_queue __P((void)); static int add_addrsel_policyent __P((struct in6_addrpolicy *)); static int delete_addrsel_policyent __P((struct in6_addrpolicy *)); static int walk_addrsel_policy __P((int (*)(struct in6_addrpolicy *, void *), void *)); static int dump_addrsel_policyent __P((struct in6_addrpolicy *, void *)); static struct in6_addrpolicy *match_addrsel_policy __P((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. */ #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) 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_in6 *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 prefer_tempaddr; dst = dstsock->sin6_addr; /* make a copy for local operation */ *errorp = 0; if (ifpp) *ifpp = NULL; /* * 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, &ifp)) != 0) { return (NULL); } /* * 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); } /* * Otherwise, if the socket has already bound the source, just use it. */ if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) return (laddr); /* * 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, &ifp)) != 0) return (NULL); #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; /* 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 */ /* * XXX: This is a TODO. We should probably merge the MIP6 * case above. */ /* 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 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); } if (ifpp) *ifpp = ifp; return (&ia->ia_addr.sin6_addr); } 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_in6 *ro; struct ifnet **retifp; struct rtentry **retrt; int clone; /* meaningful only for bsdi and freebsd. */ 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 = &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. */ ifp = ifnet_byindex(pi->ipi6_ifindex); if (ifp != NULL && (norouteok || retrt == NULL || IN6_IS_ADDR_MULTICAST(dst))) { /* * we do not have to check nor 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_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 && (ron->ro_rt->rt_flags & (RTF_UP | RTF_LLINFO)) != (RTF_UP | RTF_LLINFO)) || !SA6_ARE_ADDR_EQUAL(satosin6(&ron->ro_dst), sin6_next)) { if (ron->ro_rt) { RTFREE(ron->ro_rt); ron->ro_rt = NULL; } *satosin6(&ron->ro_dst) = *sin6_next; } if (ron->ro_rt == NULL) { rtalloc((struct route *)ron); /* multi path case? */ if (ron->ro_rt == NULL || !(ron->ro_rt->rt_flags & RTF_LLINFO)) { if (ron->ro_rt) { RTFREE(ron->ro_rt); ron->ro_rt = NULL; } 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) { if (ro->ro_rt && (!(ro->ro_rt->rt_flags & RTF_UP) || ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 || !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst))) { RTFREE(ro->ro_rt); ro->ro_rt = (struct rtentry *)NULL; } if (ro->ro_rt == (struct rtentry *)NULL) { struct sockaddr_in6 *sa6; /* No route yet, so try to acquire one */ bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); sa6 = (struct sockaddr_in6 *)&ro->ro_dst; *sa6 = *dstsock; sa6->sin6_scope_id = 0; if (clone) { rtalloc((struct route *)ro); } else { ro->ro_rt = rtalloc1(&((struct route *)ro) ->ro_dst, 0, 0UL); if (ro->ro_rt) RT_UNLOCK(ro->ro_rt); } } /* * do not care about the result if we have the nexthop * explicitly specified. */ if (opts && opts->ip6po_nexthop) goto done; if (ro->ro_rt) { ifp = ro->ro_rt->rt_ifp; if (ifp == NULL) { /* can this really happen? */ RTFREE(ro->ro_rt); ro->ro_rt = NULL; } } if (ro->ro_rt == NULL) error = EHOSTUNREACH; 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 (ifp && 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_in6 *ro; struct ifnet **retifp; { int error; struct route_in6 sro; struct rtentry *rt = NULL; if (ro == NULL) { bzero(&sro, sizeof(sro)); ro = &sro; } if ((error = selectroute(dstsock, opts, mopts, ro, retifp, &rt, 0, 1)) != 0) { if (rt && rt == sro.ro_rt) RTFREE(rt); 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))) { int flags = (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); if (rt && rt == sro.ro_rt) RTFREE(rt); return (flags); } /* * 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; if (rt && rt == sro.ro_rt) RTFREE(rt); 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_in6 *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 if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) { struct route_in6 ro6; struct ifnet *lifp; bzero(&ro6, sizeof(ro6)); ro6.ro_dst.sin6_family = AF_INET6; ro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); ro6.ro_dst.sin6_addr = in6p->in6p_faddr; rtalloc((struct route *)&ro6); if (ro6.ro_rt) { lifp = ro6.ro_rt->rt_ifp; RTFREE(ro6.ro_rt); if (lifp) return (ND_IFINFO(lifp)->chlim); } else return (ip6_defhlim); } return (ip6_defhlim); } /* * XXX: this is borrowed from in6_pcbbind(). If possible, we should * share this function by all *bsd*... */ int in6_pcbsetport(laddr, inp, cred) struct in6_addr *laddr; struct inpcb *inp; struct ucred *cred; { struct socket *so = inp->inp_socket; u_int16_t lport = 0, first, last, *lastport; int count, error = 0, wild = 0; struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; /* XXX: this is redundant when called from in6_pcbbind */ if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) wild = INPLOOKUP_WILDCARD; inp->inp_flags |= INP_ANONPORT; if (inp->inp_flags & INP_HIGHPORT) { first = ipport_hifirstauto; /* sysctl */ last = ipport_hilastauto; lastport = &pcbinfo->lasthi; } else if (inp->inp_flags & INP_LOWPORT) { if ((error = suser_cred(cred, 0))) return error; first = ipport_lowfirstauto; /* 1023 */ last = ipport_lowlastauto; /* 600 */ lastport = &pcbinfo->lastlow; } else { first = ipport_firstauto; /* sysctl */ last = ipport_lastauto; lastport = &pcbinfo->lastport; } /* * Simple check to ensure all ports are not used up causing * a deadlock here. * * We split the two cases (up and down) so that the direction * is not being tested on each round of the loop. */ if (first > last) { /* * counting down */ count = first - last; do { if (count-- < 0) { /* completely used? */ /* * Undo any address bind that may have * occurred above. */ inp->in6p_laddr = in6addr_any; return (EAGAIN); } --*lastport; if (*lastport > first || *lastport < last) *lastport = first; lport = htons(*lastport); } while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr, lport, wild)); } else { /* * counting up */ count = last - first; do { if (count-- < 0) { /* completely used? */ /* * Undo any address bind that may have * occurred above. */ inp->in6p_laddr = in6addr_any; return (EAGAIN); } ++*lastport; if (*lastport < first || *lastport > last) *lastport = first; lport = htons(*lastport); } while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr, lport, wild)); } inp->inp_lport = lport; if (in_pcbinshash(inp) != 0) { inp->in6p_laddr = in6addr_any; inp->inp_lport = 0; return (EAGAIN); } return (0); } void addrsel_policy_init() { ADDRSEL_LOCK_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; ADDRSEL_LOCK(); match = match_addrsel_policy(key); if (match == NULL) match = &defaultaddrpolicy; else match->use++; ADDRSEL_UNLOCK(); return (match); } /* * Subroutines to manage the address selection policy table via sysctl. */ struct walkarg { struct sysctl_req *w_req; }; static int in6_src_sysctl(SYSCTL_HANDLER_ARGS); SYSCTL_DECL(_net_inet6_ip6); SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy, CTLFLAG_RD, in6_src_sysctl, ""); static int in6_src_sysctl(SYSCTL_HANDLER_ARGS) { struct walkarg w; if (req->newptr) return EPERM; bzero(&w, sizeof(w)); w.w_req = req; return (walk_addrsel_policy(dump_addrsel_policyent, &w)); } int in6_src_ioctl(cmd, data) u_long cmd; caddr_t 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; MALLOC(new, struct addrsel_policyent *, sizeof(*new), M_IFADDR, M_WAITOK); ADDRSEL_LOCK(); /* duplication check */ for (pol = TAILQ_FIRST(&addrsel_policytab); pol; pol = TAILQ_NEXT(pol, ape_entry)) { if (SA6_ARE_ADDR_EQUAL(&newpolicy->addr, &pol->ape_policy.addr) && SA6_ARE_ADDR_EQUAL(&newpolicy->addrmask, &pol->ape_policy.addrmask)) { ADDRSEL_UNLOCK(); FREE(new, M_IFADDR); return (EEXIST); /* or override it? */ } } bzero(new, sizeof(*new)); /* XXX: should validate entry */ new->ape_policy = *newpolicy; TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry); ADDRSEL_UNLOCK(); return (0); } static int delete_addrsel_policyent(key) struct in6_addrpolicy *key; { struct addrsel_policyent *pol; ADDRSEL_LOCK(); /* search for the entry in the table */ for (pol = TAILQ_FIRST(&addrsel_policytab); pol; pol = TAILQ_NEXT(pol, ape_entry)) { if (SA6_ARE_ADDR_EQUAL(&key->addr, &pol->ape_policy.addr) && SA6_ARE_ADDR_EQUAL(&key->addrmask, &pol->ape_policy.addrmask)) { break; } } if (pol == NULL) { ADDRSEL_UNLOCK(); return (ESRCH); } TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry); ADDRSEL_UNLOCK(); return (0); } static int walk_addrsel_policy(callback, w) int (*callback) __P((struct in6_addrpolicy *, void *)); void *w; { struct addrsel_policyent *pol; int error = 0; ADDRSEL_LOCK(); for (pol = TAILQ_FIRST(&addrsel_policytab); pol; pol = TAILQ_NEXT(pol, ape_entry)) { if ((error = (*callback)(&pol->ape_policy, w)) != 0) { ADDRSEL_UNLOCK(); return (error); } } ADDRSEL_UNLOCK(); return (error); } static int dump_addrsel_policyent(pol, arg) 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 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); }