/* $OpenBSD: nd6.c,v 1.109 2014/01/13 23:03:52 bluhm Exp $ */ /* $KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #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 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */ #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */ #define SDL(s) ((struct sockaddr_dl *)s) /* timer values */ int nd6_prune = 1; /* walk list every 1 seconds */ int nd6_delay = 5; /* delay first probe time 5 second */ int nd6_umaxtries = 3; /* maximum unicast query */ int nd6_mmaxtries = 3; /* maximum multicast query */ int nd6_useloopback = 1; /* use loopback interface for local traffic */ int nd6_gctimer = (60 * 60 * 24); /* 1 day: garbage collection timer */ /* preventing too many loops in ND option parsing */ int nd6_maxndopt = 10; /* max # of ND options allowed */ int nd6_maxnudhint = 0; /* max # of subsequent upper layer hints */ #ifdef ND6_DEBUG int nd6_debug = 1; #else int nd6_debug = 0; #endif static int nd6_inuse, nd6_allocated; struct llinfo_nd6 llinfo_nd6 = {&llinfo_nd6, &llinfo_nd6}; struct nd_drhead nd_defrouter; struct nd_prhead nd_prefix = { 0 }; int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL; static struct sockaddr_in6 all1_sa; void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *); void nd6_slowtimo(void *); struct llinfo_nd6 *nd6_free(struct rtentry *, int); void nd6_llinfo_timer(void *); struct timeout nd6_slowtimo_ch; struct timeout nd6_timer_ch; int fill_drlist(void *, size_t *, size_t); int fill_prlist(void *, size_t *, size_t); #define LN_DEQUEUE(ln) do { \ (ln)->ln_next->ln_prev = (ln)->ln_prev; \ (ln)->ln_prev->ln_next = (ln)->ln_next; \ } while (0) #define LN_INSERTHEAD(ln) do { \ (ln)->ln_next = llinfo_nd6.ln_next; \ llinfo_nd6.ln_next = (ln); \ (ln)->ln_prev = &llinfo_nd6; \ (ln)->ln_next->ln_prev = (ln); \ } while (0) void nd6_init(void) { static int nd6_init_done = 0; int i; if (nd6_init_done) { log(LOG_NOTICE, "nd6_init called more than once(ignored)\n"); return; } all1_sa.sin6_family = AF_INET6; all1_sa.sin6_len = sizeof(struct sockaddr_in6); for (i = 0; i < sizeof(all1_sa.sin6_addr); i++) all1_sa.sin6_addr.s6_addr[i] = 0xff; /* initialization of the default router list */ TAILQ_INIT(&nd_defrouter); nd6_init_done = 1; /* start timer */ timeout_set(&nd6_slowtimo_ch, nd6_slowtimo, NULL); timeout_add_sec(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL); } struct nd_ifinfo * nd6_ifattach(struct ifnet *ifp) { struct nd_ifinfo *nd; nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO); nd->initialized = 1; nd->chlim = IPV6_DEFHLIM; nd->basereachable = REACHABLE_TIME; nd->reachable = ND_COMPUTE_RTIME(nd->basereachable); nd->retrans = RETRANS_TIMER; /* * Note that the default value of ip6_accept_rtadv is 0, which means * we won't accept RAs by default even if we set ND6_IFF_ACCEPT_RTADV * here. */ nd->flags = (ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV); /* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */ nd6_setmtu0(ifp, nd); return nd; } void nd6_ifdetach(struct nd_ifinfo *nd) { free(nd, M_IP6NDP); } void nd6_setmtu(struct ifnet *ifp) { nd6_setmtu0(ifp, ND_IFINFO(ifp)); } void nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi) { u_int32_t omaxmtu; omaxmtu = ndi->maxmtu; ndi->maxmtu = ifp->if_mtu; /* * Decreasing the interface MTU under IPV6 minimum MTU may cause * undesirable situation. We thus notify the operator of the change * explicitly. The check for omaxmtu is necessary to restrict the * log to the case of changing the MTU, not initializing it. */ if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) { log(LOG_NOTICE, "nd6_setmtu0: " "new link MTU on %s (%lu) is too small for IPv6\n", ifp->if_xname, (unsigned long)ndi->maxmtu); } if (ndi->maxmtu > in6_maxmtu) in6_setmaxmtu(); /* check all interfaces just in case */ } void nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts) { bzero(ndopts, sizeof(*ndopts)); ndopts->nd_opts_search = (struct nd_opt_hdr *)opt; ndopts->nd_opts_last = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len); if (icmp6len == 0) { ndopts->nd_opts_done = 1; ndopts->nd_opts_search = NULL; } } /* * Take one ND option. */ struct nd_opt_hdr * nd6_option(union nd_opts *ndopts) { struct nd_opt_hdr *nd_opt; int olen; if (!ndopts) panic("ndopts == NULL in nd6_option"); if (!ndopts->nd_opts_last) panic("uninitialized ndopts in nd6_option"); if (!ndopts->nd_opts_search) return NULL; if (ndopts->nd_opts_done) return NULL; nd_opt = ndopts->nd_opts_search; /* make sure nd_opt_len is inside the buffer */ if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) { bzero(ndopts, sizeof(*ndopts)); return NULL; } olen = nd_opt->nd_opt_len << 3; if (olen == 0) { /* * Message validation requires that all included * options have a length that is greater than zero. */ bzero(ndopts, sizeof(*ndopts)); return NULL; } ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen); if (ndopts->nd_opts_search > ndopts->nd_opts_last) { /* option overruns the end of buffer, invalid */ bzero(ndopts, sizeof(*ndopts)); return NULL; } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) { /* reached the end of options chain */ ndopts->nd_opts_done = 1; ndopts->nd_opts_search = NULL; } return nd_opt; } /* * Parse multiple ND options. * This function is much easier to use, for ND routines that do not need * multiple options of the same type. */ int nd6_options(union nd_opts *ndopts) { struct nd_opt_hdr *nd_opt; int i = 0; if (!ndopts) panic("ndopts == NULL in nd6_options"); if (!ndopts->nd_opts_last) panic("uninitialized ndopts in nd6_options"); if (!ndopts->nd_opts_search) return 0; while (1) { nd_opt = nd6_option(ndopts); if (!nd_opt && !ndopts->nd_opts_last) { /* * Message validation requires that all included * options have a length that is greater than zero. */ icmp6stat.icp6s_nd_badopt++; bzero(ndopts, sizeof(*ndopts)); return -1; } if (!nd_opt) goto skip1; switch (nd_opt->nd_opt_type) { case ND_OPT_SOURCE_LINKADDR: case ND_OPT_TARGET_LINKADDR: case ND_OPT_MTU: case ND_OPT_REDIRECTED_HEADER: if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { nd6log((LOG_INFO, "duplicated ND6 option found (type=%d)\n", nd_opt->nd_opt_type)); /* XXX bark? */ } else { ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; } break; case ND_OPT_PREFIX_INFORMATION: if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) { ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; } ndopts->nd_opts_pi_end = (struct nd_opt_prefix_info *)nd_opt; break; default: /* * Unknown options must be silently ignored, * to accommodate future extension to the protocol. */ nd6log((LOG_DEBUG, "nd6_options: unsupported option %d - " "option ignored\n", nd_opt->nd_opt_type)); } skip1: i++; if (i > nd6_maxndopt) { icmp6stat.icp6s_nd_toomanyopt++; nd6log((LOG_INFO, "too many loop in nd opt\n")); break; } if (ndopts->nd_opts_done) break; } return 0; } /* * ND6 timer routine to handle ND6 entries */ void nd6_llinfo_settimer(struct llinfo_nd6 *ln, long tick) { int s; s = splsoftnet(); if (tick < 0) { ln->ln_expire = 0; ln->ln_ntick = 0; timeout_del(&ln->ln_timer_ch); } else { ln->ln_expire = time_second + tick / hz; if (tick > INT_MAX) { ln->ln_ntick = tick - INT_MAX; timeout_add(&ln->ln_timer_ch, INT_MAX); } else { ln->ln_ntick = 0; timeout_add(&ln->ln_timer_ch, tick); } } splx(s); } void nd6_llinfo_timer(void *arg) { int s; struct llinfo_nd6 *ln; struct rtentry *rt; struct sockaddr_in6 *dst; struct ifnet *ifp; struct nd_ifinfo *ndi = NULL; s = splsoftnet(); ln = (struct llinfo_nd6 *)arg; if (ln->ln_ntick > 0) { if (ln->ln_ntick > INT_MAX) { ln->ln_ntick -= INT_MAX; nd6_llinfo_settimer(ln, INT_MAX); } else { ln->ln_ntick = 0; nd6_llinfo_settimer(ln, ln->ln_ntick); } splx(s); return; } if ((rt = ln->ln_rt) == NULL) panic("ln->ln_rt == NULL"); if ((ifp = rt->rt_ifp) == NULL) panic("ln->ln_rt->rt_ifp == NULL"); ndi = ND_IFINFO(ifp); dst = satosin6(rt_key(rt)); /* sanity check */ if (rt->rt_llinfo && (struct llinfo_nd6 *)rt->rt_llinfo != ln) panic("rt_llinfo(%p) is not equal to ln(%p)", rt->rt_llinfo, ln); if (!dst) panic("dst=0 in nd6_timer(ln=%p)", ln); switch (ln->ln_state) { case ND6_LLINFO_INCOMPLETE: if (ln->ln_asked < nd6_mmaxtries) { ln->ln_asked++; nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000); nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0); } else { struct mbuf *m = ln->ln_hold; if (m) { ln->ln_hold = NULL; /* * Fake rcvif to make the ICMP error * more helpful in diagnosing for the * receiver. * XXX: should we consider * older rcvif? */ m->m_pkthdr.rcvif = rt->rt_ifp; icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0); if (ln->ln_hold == m) { /* m is back in ln_hold. Discard. */ m_freem(ln->ln_hold); ln->ln_hold = NULL; } } (void)nd6_free(rt, 0); ln = NULL; } break; case ND6_LLINFO_REACHABLE: if (!ND6_LLINFO_PERMANENT(ln)) { ln->ln_state = ND6_LLINFO_STALE; nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz); } break; case ND6_LLINFO_STALE: case ND6_LLINFO_PURGE: /* Garbage Collection(RFC 2461 5.3) */ if (!ND6_LLINFO_PERMANENT(ln)) { (void)nd6_free(rt, 1); ln = NULL; } break; case ND6_LLINFO_DELAY: if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) { /* We need NUD */ ln->ln_asked = 1; ln->ln_state = ND6_LLINFO_PROBE; nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000); nd6_ns_output(ifp, &dst->sin6_addr, &dst->sin6_addr, ln, 0); } else { ln->ln_state = ND6_LLINFO_STALE; /* XXX */ nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz); } break; case ND6_LLINFO_PROBE: if (ln->ln_asked < nd6_umaxtries) { ln->ln_asked++; nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000); nd6_ns_output(ifp, &dst->sin6_addr, &dst->sin6_addr, ln, 0); } else { (void)nd6_free(rt, 0); ln = NULL; } break; } splx(s); } /* * ND6 timer routine to expire default route list and prefix list */ void nd6_timer(void *ignored_arg) { int s; struct nd_defrouter *dr, *ndr; struct nd_prefix *pr, *npr; struct in6_ifaddr *ia6, *nia6; s = splsoftnet(); timeout_set(&nd6_timer_ch, nd6_timer, NULL); timeout_add_sec(&nd6_timer_ch, nd6_prune); /* expire default router list */ TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, ndr) if (dr->expire && dr->expire < time_second) defrtrlist_del(dr); /* * expire interface addresses. * in the past the loop was inside prefix expiry processing. * However, from a stricter spec-conformance standpoint, we should * rather separate address lifetimes and prefix lifetimes. */ TAILQ_FOREACH_SAFE(ia6, &in6_ifaddr, ia_list, nia6) { /* check address lifetime */ if (IFA6_IS_INVALID(ia6)) { in6_purgeaddr(&ia6->ia_ifa); } else if (IFA6_IS_DEPRECATED(ia6)) { ia6->ia6_flags |= IN6_IFF_DEPRECATED; } else { /* * A new RA might have made a deprecated address * preferred. */ ia6->ia6_flags &= ~IN6_IFF_DEPRECATED; } } /* expire prefix list */ LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, npr) { /* * check prefix lifetime. * since pltime is just for autoconf, pltime processing for * prefix is not necessary. */ if (pr->ndpr_vltime != ND6_INFINITE_LIFETIME && time_second - pr->ndpr_lastupdate > pr->ndpr_vltime) { /* * address expiration and prefix expiration are * separate. NEVER perform in6_purgeaddr here. */ prelist_remove(pr); } } splx(s); } /* * Nuke neighbor cache/prefix/default router management table, right before * ifp goes away. */ void nd6_purge(struct ifnet *ifp) { struct llinfo_nd6 *ln, *nln; struct nd_defrouter *dr, *ndr; struct nd_prefix *pr, *npr; /* * Nuke default router list entries toward ifp. * We defer removal of default router list entries that is installed * in the routing table, in order to keep additional side effects as * small as possible. */ TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, ndr) { if (dr->installed) continue; if (dr->ifp == ifp) defrtrlist_del(dr); } TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, ndr) { if (!dr->installed) continue; if (dr->ifp == ifp) defrtrlist_del(dr); } /* Nuke prefix list entries toward ifp */ LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, npr) { if (pr->ndpr_ifp == ifp) { /* * Because if_detach() does *not* release prefixes * while purging addresses the reference count will * still be above zero. We therefore reset it to * make sure that the prefix really gets purged. */ pr->ndpr_refcnt = 0; /* * Previously, pr->ndpr_addr is removed as well, * but I strongly believe we don't have to do it. * nd6_purge() is only called from in6_ifdetach(), * which removes all the associated interface addresses * by itself. * (jinmei@kame.net 20010129) */ prelist_remove(pr); } } if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */ /* refresh default router list */ defrouter_select(); } /* * Nuke neighbor cache entries for the ifp. * Note that rt->rt_ifp may not be the same as ifp, * due to KAME goto ours hack. See RTM_RESOLVE case in * nd6_rtrequest(), and ip6_input(). */ ln = llinfo_nd6.ln_next; while (ln && ln != &llinfo_nd6) { struct rtentry *rt; struct sockaddr_dl *sdl; nln = ln->ln_next; rt = ln->ln_rt; if (rt && rt->rt_gateway && rt->rt_gateway->sa_family == AF_LINK) { sdl = (struct sockaddr_dl *)rt->rt_gateway; if (sdl->sdl_index == ifp->if_index) nln = nd6_free(rt, 0); } ln = nln; } } struct rtentry * nd6_lookup(struct in6_addr *addr6, int create, struct ifnet *ifp, u_int rtableid) { struct rtentry *rt; struct sockaddr_in6 sin6; bzero(&sin6, sizeof(sin6)); sin6.sin6_len = sizeof(struct sockaddr_in6); sin6.sin6_family = AF_INET6; sin6.sin6_addr = *addr6; rt = rtalloc1(sin6tosa(&sin6), create, rtableid); if (rt && (rt->rt_flags & RTF_LLINFO) == 0) { /* * This is the case for the default route. * If we want to create a neighbor cache for the address, we * should free the route for the destination and allocate an * interface route. */ if (create) { RTFREE(rt); rt = 0; } } if (!rt) { if (create && ifp) { struct rt_addrinfo info; int e; /* * If no route is available and create is set, * we allocate a host route for the destination * and treat it like an interface route. * This hack is necessary for a neighbor which can't * be covered by our own prefix. */ struct ifaddr *ifa = ifaof_ifpforaddr(sin6tosa(&sin6), ifp); if (ifa == NULL) return (NULL); /* * Create a new route. RTF_LLINFO is necessary * to create a Neighbor Cache entry for the * destination in nd6_rtrequest which will be * called in rtrequest1 via ifa->ifa_rtrequest. */ bzero(&info, sizeof(info)); info.rti_flags = (ifa->ifa_flags | RTF_HOST | RTF_LLINFO) & ~RTF_CLONING; info.rti_info[RTAX_DST] = sin6tosa(&sin6); info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr; info.rti_info[RTAX_NETMASK] = sin6tosa(&all1_sa); if ((e = rtrequest1(RTM_ADD, &info, RTP_CONNECTED, &rt, rtableid)) != 0) { #if 0 char ip[INET6_ADDRSTRLEN]; log(LOG_ERR, "nd6_lookup: failed to add route for a " "neighbor(%s), errno=%d\n", inet_ntop(AF_INET6, addr6, ip, sizeof(ip)), e); #endif return (NULL); } if (rt == NULL) return (NULL); if (rt->rt_llinfo) { struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; ln->ln_state = ND6_LLINFO_NOSTATE; } } else return (NULL); } rt->rt_refcnt--; /* * Validation for the entry. * Note that the check for rt_llinfo is necessary because a cloned * route from a parent route that has the L flag (e.g. the default * route to a p2p interface) may have the flag, too, while the * destination is not actually a neighbor. * XXX: we can't use rt->rt_ifp to check for the interface, since * it might be the loopback interface if the entry is for our * own address on a non-loopback interface. Instead, we should * use rt->rt_ifa->ifa_ifp, which would specify the REAL * interface. */ if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 || rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL || (ifp && rt->rt_ifa->ifa_ifp != ifp)) { if (create) { char addr[INET6_ADDRSTRLEN]; nd6log((LOG_DEBUG, "nd6_lookup: failed to lookup %s (if = %s)\n", inet_ntop(AF_INET6, addr6, addr, sizeof(addr)), ifp ? ifp->if_xname : "unspec")); } return (NULL); } return (rt); } /* * Detect if a given IPv6 address identifies a neighbor on a given link. * XXX: should take care of the destination of a p2p link? */ int nd6_is_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp) { struct nd_prefix *pr; struct rtentry *rt; /* * A link-local address is always a neighbor. * XXX: we should use the sin6_scope_id field rather than the embedded * interface index. * XXX: a link does not necessarily specify a single interface. */ if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) && ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index) return (1); /* * If the address matches one of our on-link prefixes, it should be a * neighbor. */ LIST_FOREACH(pr, &nd_prefix, ndpr_entry) { if (pr->ndpr_ifp != ifp) continue; if (!(pr->ndpr_stateflags & NDPRF_ONLINK)) continue; if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr, &addr->sin6_addr, &pr->ndpr_mask)) return (1); } /* * Even if the address matches none of our addresses, it might be * in the neighbor cache. */ if ((rt = nd6_lookup(&addr->sin6_addr, 0, ifp, ifp->if_rdomain)) != NULL) return (1); return (0); } /* * Free an nd6 llinfo entry. * Since the function would cause significant changes in the kernel, DO NOT * make it global, unless you have a strong reason for the change, and are sure * that the change is safe. */ struct llinfo_nd6 * nd6_free(struct rtentry *rt, int gc) { struct rt_addrinfo info; struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo, *next; struct in6_addr in6 = satosin6(rt_key(rt))->sin6_addr; struct nd_defrouter *dr; /* * we used to have pfctlinput(PRC_HOSTDEAD) here. * even though it is not harmful, it was not really necessary. */ if (!ip6_forwarding) { int s; s = splsoftnet(); dr = defrouter_lookup(&satosin6(rt_key(rt))->sin6_addr, rt->rt_ifp); if (dr != NULL && dr->expire && ln->ln_state == ND6_LLINFO_STALE && gc) { /* * If the reason for the deletion is just garbage * collection, and the neighbor is an active default * router, do not delete it. Instead, reset the GC * timer using the router's lifetime. * Simply deleting the entry would affect default * router selection, which is not necessarily a good * thing, especially when we're using router preference * values. * XXX: the check for ln_state would be redundant, * but we intentionally keep it just in case. */ if (dr->expire > time_second * hz) { nd6_llinfo_settimer(ln, dr->expire - time_second * hz); } else nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz); splx(s); return (ln->ln_next); } if (ln->ln_router || dr) { /* * rt6_flush must be called whether or not the neighbor * is in the Default Router List. * See a corresponding comment in nd6_na_input(). */ rt6_flush(&in6, rt->rt_ifp); } if (dr) { /* * Unreachability of a router might affect the default * router selection and on-link detection of advertised * prefixes. */ /* * Temporarily fake the state to choose a new default * router and to perform on-link determination of * prefixes correctly. * Below the state will be set correctly, * or the entry itself will be deleted. */ ln->ln_state = ND6_LLINFO_INCOMPLETE; /* * Since defrouter_select() does not affect the * on-link determination and MIP6 needs the check * before the default router selection, we perform * the check now. */ pfxlist_onlink_check(); /* * refresh default router list */ defrouter_select(); } splx(s); } /* * Before deleting the entry, remember the next entry as the * return value. We need this because pfxlist_onlink_check() above * might have freed other entries (particularly the old next entry) as * a side effect (XXX). */ next = ln->ln_next; /* * Detach the route from the routing tree and the list of neighbor * caches, and disable the route entry not to be used in already * cached routes. */ bzero(&info, sizeof(info)); info.rti_info[RTAX_DST] = rt_key(rt); info.rti_info[RTAX_NETMASK] = rt_mask(rt); rtrequest1(RTM_DELETE, &info, rt->rt_priority, NULL, rt->rt_ifp->if_rdomain); return (next); } /* * Upper-layer reachability hint for Neighbor Unreachability Detection. * * XXX cost-effective methods? */ void nd6_nud_hint(struct rtentry *rt, struct in6_addr *dst6, int force, u_int rtableid) { struct llinfo_nd6 *ln; /* * If the caller specified "rt", use that. Otherwise, resolve the * routing table by supplied "dst6". */ if (!rt) { if (!dst6) return; if (!(rt = nd6_lookup(dst6, 0, NULL, rtableid))) return; } if ((rt->rt_flags & RTF_GATEWAY) != 0 || (rt->rt_flags & RTF_LLINFO) == 0 || !rt->rt_llinfo || !rt->rt_gateway || rt->rt_gateway->sa_family != AF_LINK) { /* This is not a host route. */ return; } ln = (struct llinfo_nd6 *)rt->rt_llinfo; if (ln->ln_state < ND6_LLINFO_REACHABLE) return; /* * if we get upper-layer reachability confirmation many times, * it is possible we have false information. */ if (!force) { ln->ln_byhint++; if (ln->ln_byhint > nd6_maxnudhint) return; } ln->ln_state = ND6_LLINFO_REACHABLE; if (!ND6_LLINFO_PERMANENT(ln)) { nd6_llinfo_settimer(ln, (long)ND_IFINFO(rt->rt_ifp)->reachable * hz); } } void nd6_rtrequest(int req, struct rtentry *rt) { struct sockaddr *gate = rt->rt_gateway; struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK}; struct ifnet *ifp = rt->rt_ifp; struct ifaddr *ifa; struct nd_defrouter *dr; if (req == RTM_DELETE && (rt->rt_flags & RTF_GATEWAY) && (IN6_ARE_ADDR_EQUAL(&(satosin6(rt_key(rt)))->sin6_addr, &in6addr_any) && rt_mask(rt) && (rt_mask(rt)->sa_len == 0 || IN6_ARE_ADDR_EQUAL(&(satosin6(rt_mask(rt)))->sin6_addr, &in6addr_any)))) { dr = defrouter_lookup(&satosin6(gate)->sin6_addr, ifp); if (dr) dr->installed = 0; } if ((rt->rt_flags & RTF_GATEWAY) != 0) return; if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) { /* * This is probably an interface direct route for a link * which does not need neighbor caches (e.g. fe80::%lo0/64). * We do not need special treatment below for such a route. * Moreover, the RTF_LLINFO flag which would be set below * would annoy the ndp(8) command. */ return; } if (req == RTM_RESOLVE && nd6_need_cache(ifp) == 0) { /* * For routing daemons like ospf6d we allow neighbor discovery * based on the cloning route only. This allows us to sent * packets directly into a network without having an address * with matching prefix on the interface. If the cloning * route is used for an stf interface, we would mistakenly * make a neighbor cache for the host route, and would see * strange neighbor solicitation for the corresponding * destination. In order to avoid confusion, we check if the * interface is suitable for neighbor discovery, and stop the * process if not. Additionally, we remove the LLINFO flag * so that ndp(8) will not try to get the neighbor information * of the destination. */ rt->rt_flags &= ~RTF_LLINFO; return; } switch (req) { case RTM_ADD: /* * There is no backward compatibility :) * * if ((rt->rt_flags & RTF_HOST) == 0 && * SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) * rt->rt_flags |= RTF_CLONING; */ if ((rt->rt_flags & RTF_CLONING) || ((rt->rt_flags & RTF_LLINFO) && !ln)) { /* * Case 1: This route should come from a route to * interface (RTF_CLONING case) or the route should be * treated as on-link but is currently not * (RTF_LLINFO && !ln case). */ rt_setgate(rt, rt_key(rt), (struct sockaddr *)&null_sdl, rt->rt_ifp->if_rdomain); gate = rt->rt_gateway; SDL(gate)->sdl_type = ifp->if_type; SDL(gate)->sdl_index = ifp->if_index; if (ln) nd6_llinfo_settimer(ln, 0); if ((rt->rt_flags & RTF_CLONING) != 0) break; } /* * In IPv4 code, we try to announce new RTF_ANNOUNCE entry here. * We don't do that here since llinfo is not ready yet. * * There are also couple of other things to be discussed: * - unsolicited NA code needs improvement beforehand * - RFC2461 says we MAY send multicast unsolicited NA * (7.2.6 paragraph 4), however, it also says that we * SHOULD provide a mechanism to prevent multicast NA storm. * we don't have anything like it right now. * note that the mechanism needs a mutual agreement * between proxies, which means that we need to implement * a new protocol, or a new kludge. * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA. * we need to check ip6forwarding before sending it. * (or should we allow proxy ND configuration only for * routers? there's no mention about proxy ND from hosts) */ #if 0 /* XXX it does not work */ if (rt->rt_flags & RTF_ANNOUNCE) nd6_na_output(ifp, &satosin6(rt_key(rt))->sin6_addr, &satosin6(rt_key(rt))->sin6_addr, ip6_forwarding ? ND_NA_FLAG_ROUTER : 0, 1, NULL); #endif /* FALLTHROUGH */ case RTM_RESOLVE: if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) { /* * Address resolution isn't necessary for a point to * point link, so we can skip this test for a p2p link. */ if (gate->sa_family != AF_LINK || gate->sa_len < sizeof(null_sdl)) { log(LOG_DEBUG, "nd6_rtrequest: bad gateway value: %s\n", ifp->if_xname); break; } SDL(gate)->sdl_type = ifp->if_type; SDL(gate)->sdl_index = ifp->if_index; } if (ln != NULL) break; /* This happens on a route change */ /* * Case 2: This route may come from cloning, or a manual route * add with a LL address. */ ln = malloc(sizeof(*ln), M_RTABLE, M_NOWAIT | M_ZERO); rt->rt_llinfo = (caddr_t)ln; if (!ln) { log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n"); break; } nd6_inuse++; nd6_allocated++; ln->ln_rt = rt; timeout_set(&ln->ln_timer_ch, nd6_llinfo_timer, ln); /* this is required for "ndp" command. - shin */ if (req == RTM_ADD) { /* * gate should have some valid AF_LINK entry, * and ln->ln_expire should have some lifetime * which is specified by ndp command. */ ln->ln_state = ND6_LLINFO_REACHABLE; ln->ln_byhint = 0; } else { /* * When req == RTM_RESOLVE, rt is created and * initialized in rtrequest(), so rt_expire is 0. */ ln->ln_state = ND6_LLINFO_NOSTATE; nd6_llinfo_settimer(ln, 0); } rt->rt_flags |= RTF_LLINFO; ln->ln_next = llinfo_nd6.ln_next; llinfo_nd6.ln_next = ln; ln->ln_prev = &llinfo_nd6; ln->ln_next->ln_prev = ln; /* * If we have too many cache entries, initiate immediate * purging for some "less recently used" entries. Note that * we cannot directly call nd6_free() here because it would * cause re-entering rtable related routines triggering an LOR * problem for FreeBSD. */ if (ip6_neighborgcthresh >= 0 && nd6_inuse >= ip6_neighborgcthresh) { int i; for (i = 0; i < 10 && llinfo_nd6.ln_prev != ln; i++) { struct llinfo_nd6 *ln_end = llinfo_nd6.ln_prev; /* Move this entry to the head */ LN_DEQUEUE(ln_end); LN_INSERTHEAD(ln_end); if (ND6_LLINFO_PERMANENT(ln_end)) continue; if (ln_end->ln_state > ND6_LLINFO_INCOMPLETE) ln_end->ln_state = ND6_LLINFO_STALE; else ln_end->ln_state = ND6_LLINFO_PURGE; nd6_llinfo_settimer(ln_end, 0); } } /* * check if rt_key(rt) is one of my address assigned * to the interface. */ ifa = &in6ifa_ifpwithaddr(rt->rt_ifp, &satosin6(rt_key(rt))->sin6_addr)->ia_ifa; if (ifa) { caddr_t macp = nd6_ifptomac(ifp); nd6_llinfo_settimer(ln, -1); ln->ln_state = ND6_LLINFO_REACHABLE; ln->ln_byhint = 0; if (macp) { memcpy(LLADDR(SDL(gate)), macp, ifp->if_addrlen); SDL(gate)->sdl_alen = ifp->if_addrlen; } if (nd6_useloopback) { rt->rt_ifp = lo0ifp; /*XXX*/ /* * Make sure rt_ifa be equal to the ifaddr * corresponding to the address. * We need this because when we refer * rt_ifa->ia6_flags in ip6_input, we assume * that the rt_ifa points to the address instead * of the loopback address. */ if (ifa != rt->rt_ifa) { ifafree(rt->rt_ifa); ifa->ifa_refcnt++; rt->rt_ifa = ifa; } } } else if (rt->rt_flags & RTF_ANNOUNCE) { nd6_llinfo_settimer(ln, -1); ln->ln_state = ND6_LLINFO_REACHABLE; ln->ln_byhint = 0; /* join solicited node multicast for proxy ND */ if (ifp->if_flags & IFF_MULTICAST) { struct in6_addr llsol; int error; llsol = satosin6(rt_key(rt))->sin6_addr; llsol.s6_addr16[0] = htons(0xff02); llsol.s6_addr16[1] = htons(ifp->if_index); llsol.s6_addr32[1] = 0; llsol.s6_addr32[2] = htonl(1); llsol.s6_addr8[12] = 0xff; if (in6_addmulti(&llsol, ifp, &error)) { char addr[INET6_ADDRSTRLEN]; nd6log((LOG_ERR, "%s: failed to join " "%s (errno=%d)\n", ifp->if_xname, inet_ntop(AF_INET6, &llsol, addr, sizeof(addr)), error)); } } } break; case RTM_DELETE: if (!ln) break; /* leave from solicited node multicast for proxy ND */ if ((rt->rt_flags & RTF_ANNOUNCE) != 0 && (ifp->if_flags & IFF_MULTICAST) != 0) { struct in6_addr llsol; struct in6_multi *in6m; llsol = satosin6(rt_key(rt))->sin6_addr; llsol.s6_addr16[0] = htons(0xff02); llsol.s6_addr16[1] = htons(ifp->if_index); llsol.s6_addr32[1] = 0; llsol.s6_addr32[2] = htonl(1); llsol.s6_addr8[12] = 0xff; IN6_LOOKUP_MULTI(llsol, ifp, in6m); if (in6m) in6_delmulti(in6m); } nd6_inuse--; ln->ln_next->ln_prev = ln->ln_prev; ln->ln_prev->ln_next = ln->ln_next; ln->ln_prev = NULL; nd6_llinfo_settimer(ln, -1); rt->rt_llinfo = 0; rt->rt_flags &= ~RTF_LLINFO; if (ln->ln_hold) m_freem(ln->ln_hold); free(ln, M_RTABLE); } } int nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp) { struct in6_ndireq *ndi = (struct in6_ndireq *)data; struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data; struct rtentry *rt; int error = 0; int s; switch (cmd) { case SIOCGIFINFO_IN6: ndi->ndi = *ND_IFINFO(ifp); break; case SIOCSIFINFO_FLAGS: ND_IFINFO(ifp)->flags = ndi->ndi.flags; break; case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */ /* sync kernel routing table with the default router list */ defrouter_reset(); defrouter_select(); break; case SIOCSPFXFLUSH_IN6: { /* flush all the prefix advertised by routers */ struct nd_prefix *pr, *npr; s = splsoftnet(); /* First purge the addresses referenced by a prefix. */ LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, npr) { struct in6_ifaddr *ia6, *ia6_next; if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) continue; /* XXX */ /* do we really have to remove addresses as well? */ TAILQ_FOREACH_SAFE(ia6, &in6_ifaddr, ia_list, ia6_next) { if ((ia6->ia6_flags & IN6_IFF_AUTOCONF) == 0) continue; if (ia6->ia6_ndpr == pr) in6_purgeaddr(&ia6->ia_ifa); } } /* * Purging the addresses might remove the prefix as well. * So run the loop again to access only prefixes that have * not been freed already. */ LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, npr) { if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) continue; /* XXX */ prelist_remove(pr); } splx(s); break; } case SIOCSRTRFLUSH_IN6: { /* flush all the default routers */ struct nd_defrouter *dr, *ndr; s = splsoftnet(); defrouter_reset(); TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, ndr) defrtrlist_del(dr); defrouter_select(); splx(s); break; } case SIOCGNBRINFO_IN6: { struct llinfo_nd6 *ln; struct in6_addr nb_addr = nbi->addr; /* make local for safety */ /* * XXX: KAME specific hack for scoped addresses * XXXX: for other scopes than link-local? */ if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) || IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) { u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2]; if (*idp == 0) *idp = htons(ifp->if_index); } s = splsoftnet(); if ((rt = nd6_lookup(&nb_addr, 0, ifp, ifp->if_rdomain)) == NULL || (ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) { error = EINVAL; splx(s); break; } nbi->state = ln->ln_state; nbi->asked = ln->ln_asked; nbi->isrouter = ln->ln_router; nbi->expire = ln->ln_expire; splx(s); break; } } return (error); } /* * Create neighbor cache entry and cache link-layer address, * on reception of inbound ND6 packets. (RS/RA/NS/redirect) * * type - ICMP6 type * code - type dependent information */ struct rtentry * nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr, int lladdrlen, int type, int code) { struct rtentry *rt = NULL; struct llinfo_nd6 *ln = NULL; int is_newentry; struct sockaddr_dl *sdl = NULL; int do_update; int olladdr; int llchange; int newstate = 0; if (!ifp) panic("ifp == NULL in nd6_cache_lladdr"); if (!from) panic("from == NULL in nd6_cache_lladdr"); /* nothing must be updated for unspecified address */ if (IN6_IS_ADDR_UNSPECIFIED(from)) return NULL; /* * Validation about ifp->if_addrlen and lladdrlen must be done in * the caller. * * XXX If the link does not have link-layer address, what should * we do? (ifp->if_addrlen == 0) * Spec says nothing in sections for RA, RS and NA. There's small * description on it in NS section (RFC 2461 7.2.3). */ rt = nd6_lookup(from, 0, ifp, ifp->if_rdomain); if (!rt) { #if 0 /* nothing must be done if there's no lladdr */ if (!lladdr || !lladdrlen) return NULL; #endif rt = nd6_lookup(from, RT_REPORT, ifp, ifp->if_rdomain); is_newentry = 1; } else { /* do nothing if static ndp is set */ if (rt->rt_flags & RTF_STATIC) return NULL; is_newentry = 0; } if (!rt) return NULL; if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) { fail: (void)nd6_free(rt, 0); return NULL; } ln = (struct llinfo_nd6 *)rt->rt_llinfo; if (!ln) goto fail; if (!rt->rt_gateway) goto fail; if (rt->rt_gateway->sa_family != AF_LINK) goto fail; sdl = SDL(rt->rt_gateway); olladdr = (sdl->sdl_alen) ? 1 : 0; if (olladdr && lladdr) { if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) llchange = 1; else llchange = 0; } else llchange = 0; /* * newentry olladdr lladdr llchange (*=record) * 0 n n -- (1) * 0 y n -- (2) * 0 n y -- (3) * STALE * 0 y y n (4) * * 0 y y y (5) * STALE * 1 -- n -- (6) NOSTATE(= PASSIVE) * 1 -- y -- (7) * STALE */ if (llchange) { char addr[INET6_ADDRSTRLEN]; log(LOG_INFO, "ndp info overwritten for %s by %s on %s\n", inet_ntop(AF_INET6, from, addr, sizeof(addr)), ether_sprintf(lladdr), ifp->if_xname); } if (lladdr) { /* (3-5) and (7) */ /* * Record source link-layer address * XXX is it dependent to ifp->if_type? */ sdl->sdl_alen = ifp->if_addrlen; bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); } if (!is_newentry) { if ((!olladdr && lladdr) || /* (3) */ (olladdr && lladdr && llchange)) { /* (5) */ do_update = 1; newstate = ND6_LLINFO_STALE; } else /* (1-2,4) */ do_update = 0; } else { do_update = 1; if (!lladdr) /* (6) */ newstate = ND6_LLINFO_NOSTATE; else /* (7) */ newstate = ND6_LLINFO_STALE; } if (do_update) { /* * Update the state of the neighbor cache. */ ln->ln_state = newstate; if (ln->ln_state == ND6_LLINFO_STALE) { /* * XXX: since nd6_output() below will cause * state transition to DELAY and reset the timer, * we must set the timer now, although it is actually * meaningless. */ nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz); if (ln->ln_hold) { struct mbuf *n = ln->ln_hold; ln->ln_hold = NULL; /* * we assume ifp is not a p2p here, so just * set the 2nd argument as the 1st one. */ nd6_output(ifp, ifp, n, satosin6(rt_key(rt)), rt); if (ln->ln_hold == n) { /* n is back in ln_hold. Discard. */ m_freem(ln->ln_hold); ln->ln_hold = NULL; } } } else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { /* probe right away */ nd6_llinfo_settimer((void *)ln, 0); } } /* * ICMP6 type dependent behavior. * * NS: clear IsRouter if new entry * RS: clear IsRouter * RA: set IsRouter if there's lladdr * redir: clear IsRouter if new entry * * RA case, (1): * The spec says that we must set IsRouter in the following cases: * - If lladdr exist, set IsRouter. This means (1-5). * - If it is old entry (!newentry), set IsRouter. This means (7). * So, based on the spec, in (1-5) and (7) cases we must set IsRouter. * A question arises for (1) case. (1) case has no lladdr in the * neighbor cache, this is similar to (6). * This case is rare but we figured that we MUST NOT set IsRouter. * * newentry olladdr lladdr llchange NS RS RA redir * D R * 0 n n -- (1) c ? s * 0 y n -- (2) c s s * 0 n y -- (3) c s s * 0 y y n (4) c s s * 0 y y y (5) c s s * 1 -- n -- (6) c c c s * 1 -- y -- (7) c c s c s * * (c=clear s=set) */ switch (type & 0xff) { case ND_NEIGHBOR_SOLICIT: /* * New entry must have is_router flag cleared. */ if (is_newentry) /* (6-7) */ ln->ln_router = 0; break; case ND_REDIRECT: /* * If the icmp is a redirect to a better router, always set the * is_router flag. Otherwise, if the entry is newly created, * clear the flag. [RFC 2461, sec 8.3] */ if (code == ND_REDIRECT_ROUTER) ln->ln_router = 1; else if (is_newentry) /* (6-7) */ ln->ln_router = 0; break; case ND_ROUTER_SOLICIT: /* * is_router flag must always be cleared. */ ln->ln_router = 0; break; case ND_ROUTER_ADVERT: /* * Mark an entry with lladdr as a router. */ if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */ (is_newentry && lladdr)) { /* (7) */ ln->ln_router = 1; } break; } /* * When the link-layer address of a router changes, select the * best router again. In particular, when the neighbor entry is newly * created, it might affect the selection policy. * Question: can we restrict the first condition to the "is_newentry" * case? * XXX: when we hear an RA from a new router with the link-layer * address option, defrouter_select() is called twice, since * defrtrlist_update called the function as well. However, I believe * we can compromise the overhead, since it only happens the first * time. * XXX: although defrouter_select() should not have a bad effect * for those are not autoconfigured hosts, we explicitly avoid such * cases for safety. */ if (do_update && ln->ln_router && !ip6_forwarding && ip6_accept_rtadv) defrouter_select(); return rt; } void nd6_slowtimo(void *ignored_arg) { int s = splsoftnet(); struct nd_ifinfo *nd6if; struct ifnet *ifp; timeout_set(&nd6_slowtimo_ch, nd6_slowtimo, NULL); timeout_add_sec(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL); TAILQ_FOREACH(ifp, &ifnet, if_list) { nd6if = ND_IFINFO(ifp); if (nd6if->basereachable && /* already initialized */ (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) { /* * Since reachable time rarely changes by router * advertisements, we SHOULD insure that a new random * value gets recomputed at least once every few hours. * (RFC 2461, 6.3.4) */ nd6if->recalctm = nd6_recalc_reachtm_interval; nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable); } } splx(s); } #define senderr(e) { error = (e); goto bad;} int nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0, struct sockaddr_in6 *dst, struct rtentry *rt0) { struct mbuf *m = m0; struct rtentry *rt = rt0; struct sockaddr_in6 *gw6 = NULL; struct llinfo_nd6 *ln = NULL; int error = 0; #ifdef IPSEC struct m_tag *mtag; #endif /* IPSEC */ if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr)) goto sendpkt; if (nd6_need_cache(ifp) == 0) goto sendpkt; /* * next hop determination. This routine is derived from ether_output. */ if (rt) { if ((rt->rt_flags & RTF_UP) == 0) { if ((rt0 = rt = rtalloc1(sin6tosa(dst), RT_REPORT, m->m_pkthdr.rdomain)) != NULL) { rt->rt_refcnt--; if (rt->rt_ifp != ifp) senderr(EHOSTUNREACH); } else senderr(EHOSTUNREACH); } if (rt->rt_flags & RTF_GATEWAY) { gw6 = satosin6(rt->rt_gateway); /* * We skip link-layer address resolution and NUD * if the gateway is not a neighbor from ND point * of view, regardless of the value of nd_ifinfo.flags. * The second condition is a bit tricky; we skip * if the gateway is our own address, which is * sometimes used to install a route to a p2p link. */ if (!nd6_is_addr_neighbor(gw6, ifp) || in6ifa_ifpwithaddr(ifp, &gw6->sin6_addr)) { /* * We allow this kind of tricky route only * when the outgoing interface is p2p. * XXX: we may need a more generic rule here. */ if ((ifp->if_flags & IFF_POINTOPOINT) == 0) senderr(EHOSTUNREACH); goto sendpkt; } if (rt->rt_gwroute == 0) goto lookup; if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) { rtfree(rt); rt = rt0; lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, RT_REPORT, m->m_pkthdr.rdomain); if ((rt = rt->rt_gwroute) == 0) senderr(EHOSTUNREACH); } } } /* * Address resolution or Neighbor Unreachability Detection * for the next hop. * At this point, the destination of the packet must be a unicast * or an anycast address(i.e. not a multicast). */ /* Look up the neighbor cache for the nexthop */ if (rt && (rt->rt_flags & RTF_LLINFO) != 0) ln = (struct llinfo_nd6 *)rt->rt_llinfo; else { /* * Since nd6_is_addr_neighbor() internally calls nd6_lookup(), * the condition below is not very efficient. But we believe * it is tolerable, because this should be a rare case. */ if (nd6_is_addr_neighbor(dst, ifp) && (rt = nd6_lookup(&dst->sin6_addr, RT_REPORT, ifp, ifp->if_rdomain)) != NULL) ln = (struct llinfo_nd6 *)rt->rt_llinfo; } if (!ln || !rt) { if ((ifp->if_flags & IFF_POINTOPOINT) == 0 && !(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) { char addr[INET6_ADDRSTRLEN]; log(LOG_DEBUG, "nd6_output: can't allocate llinfo for %s " "(ln=%p, rt=%p)\n", inet_ntop(AF_INET6, &dst->sin6_addr, addr, sizeof(addr)), ln, rt); senderr(EIO); /* XXX: good error? */ } goto sendpkt; /* send anyway */ } /* * Move this entry to the head of the queue so that it is less likely * for this entry to be a target of forced garbage collection (see * nd6_rtrequest()). */ LN_DEQUEUE(ln); LN_INSERTHEAD(ln); /* We don't have to do link-layer address resolution on a p2p link. */ if ((ifp->if_flags & IFF_POINTOPOINT) != 0 && ln->ln_state < ND6_LLINFO_REACHABLE) { ln->ln_state = ND6_LLINFO_STALE; nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz); } /* * The first time we send a packet to a neighbor whose entry is * STALE, we have to change the state to DELAY and a sets a timer to * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do * neighbor unreachability detection on expiration. * (RFC 2461 7.3.3) */ if (ln->ln_state == ND6_LLINFO_STALE) { ln->ln_asked = 0; ln->ln_state = ND6_LLINFO_DELAY; nd6_llinfo_settimer(ln, nd6_delay * hz); } /* * If the neighbor cache entry has a state other than INCOMPLETE * (i.e. its link-layer address is already resolved), just * send the packet. */ if (ln->ln_state > ND6_LLINFO_INCOMPLETE) goto sendpkt; /* * There is a neighbor cache entry, but no ethernet address * response yet. Replace the held mbuf (if any) with this * latest one. */ if (ln->ln_state == ND6_LLINFO_NOSTATE) ln->ln_state = ND6_LLINFO_INCOMPLETE; if (ln->ln_hold) m_freem(ln->ln_hold); ln->ln_hold = m; /* * If there has been no NS for the neighbor after entering the * INCOMPLETE state, send the first solicitation. */ if (!ND6_LLINFO_PERMANENT(ln) && ln->ln_asked == 0) { ln->ln_asked++; nd6_llinfo_settimer(ln, (long)ND_IFINFO(ifp)->retrans * hz / 1000); nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0); } return (0); sendpkt: #ifdef IPSEC /* * If we got here and IPsec crypto processing didn't happen, drop it. */ mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); #endif /* IPSEC */ if ((ifp->if_flags & IFF_LOOPBACK) != 0) { #ifdef IPSEC if (mtag != NULL) { /* Tell IPsec to do its own crypto. */ ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); error = EACCES; goto bad; } #endif /* IPSEC */ return ((*ifp->if_output)(origifp, m, sin6tosa(dst), rt)); } #ifdef IPSEC if (mtag != NULL) { /* Tell IPsec to do its own crypto. */ ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); error = EACCES; goto bad; } #endif /* IPSEC */ return ((*ifp->if_output)(ifp, m, sin6tosa(dst), rt)); bad: if (m) m_freem(m); return (error); } #undef senderr int nd6_need_cache(struct ifnet *ifp) { /* * RFC2893 says: * - unidirectional tunnels needs no ND */ switch (ifp->if_type) { case IFT_ETHER: case IFT_IEEE1394: case IFT_PROPVIRTUAL: case IFT_L2VLAN: case IFT_IEEE80211: case IFT_CARP: case IFT_GIF: /* XXX need more cases? */ return (1); default: return (0); } } int nd6_storelladdr(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m, struct sockaddr *dst, u_char *desten) { struct sockaddr_dl *sdl; if (m->m_flags & M_MCAST) { switch (ifp->if_type) { case IFT_ETHER: ETHER_MAP_IPV6_MULTICAST(&satosin6(dst)->sin6_addr, desten); return (1); break; default: m_freem(m); return (0); } } if (rt == NULL) { /* this could happen, if we could not allocate memory */ m_freem(m); return (0); } if (rt->rt_gateway->sa_family != AF_LINK) { printf("nd6_storelladdr: something odd happens\n"); m_freem(m); return (0); } sdl = SDL(rt->rt_gateway); if (sdl->sdl_alen == 0) { char addr[INET6_ADDRSTRLEN]; /* this should be impossible, but we bark here for debugging */ printf("nd6_storelladdr: sdl_alen == 0, dst=%s, if=%s\n", inet_ntop(AF_INET6, &satosin6(dst)->sin6_addr, addr, sizeof(addr)), ifp->if_xname); m_freem(m); return (0); } bcopy(LLADDR(sdl), desten, sdl->sdl_alen); return (1); } /* * oldp - syscall arg, need copyout * newp - syscall arg, need copyin */ int nd6_sysctl(int name, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { void *p; size_t ol; int error; error = 0; if (newp) return EPERM; if (oldp && !oldlenp) return EINVAL; ol = oldlenp ? *oldlenp : 0; if (oldp) { p = malloc(*oldlenp, M_TEMP, M_WAITOK | M_CANFAIL); if (!p) return ENOMEM; } else p = NULL; switch (name) { case ICMPV6CTL_ND6_DRLIST: error = fill_drlist(p, oldlenp, ol); if (!error && p && oldp) error = copyout(p, oldp, *oldlenp); break; case ICMPV6CTL_ND6_PRLIST: error = fill_prlist(p, oldlenp, ol); if (!error && p && oldp) error = copyout(p, oldp, *oldlenp); break; default: error = ENOPROTOOPT; break; } if (p) free(p, M_TEMP); return (error); } int fill_drlist(void *oldp, size_t *oldlenp, size_t ol) { int error = 0, s; struct in6_defrouter *d = NULL, *de = NULL; struct nd_defrouter *dr; size_t l; s = splsoftnet(); if (oldp) { d = (struct in6_defrouter *)oldp; de = (struct in6_defrouter *)((caddr_t)oldp + *oldlenp); } l = 0; TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) { if (oldp && d + 1 <= de) { bzero(d, sizeof(*d)); d->rtaddr.sin6_family = AF_INET6; d->rtaddr.sin6_len = sizeof(struct sockaddr_in6); d->rtaddr.sin6_addr = dr->rtaddr; in6_recoverscope(&d->rtaddr, &d->rtaddr.sin6_addr, dr->ifp); d->flags = dr->flags; d->rtlifetime = dr->rtlifetime; d->expire = dr->expire; d->if_index = dr->ifp->if_index; } l += sizeof(*d); if (d) d++; } if (oldp) { *oldlenp = l; /* (caddr_t)d - (caddr_t)oldp */ if (l > ol) error = ENOMEM; } else *oldlenp = l; splx(s); return (error); } int fill_prlist(void *oldp, size_t *oldlenp, size_t ol) { int error = 0, s; struct nd_prefix *pr; struct in6_prefix *p = NULL; struct in6_prefix *pe = NULL; size_t l; s = splsoftnet(); if (oldp) { p = (struct in6_prefix *)oldp; pe = (struct in6_prefix *)((caddr_t)oldp + *oldlenp); } l = 0; LIST_FOREACH(pr, &nd_prefix, ndpr_entry) { u_short advrtrs; size_t advance; struct sockaddr_in6 *sin6; struct sockaddr_in6 *s6; struct nd_pfxrouter *pfr; char addr[INET6_ADDRSTRLEN]; if (oldp && p + 1 <= pe) { bzero(p, sizeof(*p)); sin6 = (struct sockaddr_in6 *)(p + 1); p->prefix = pr->ndpr_prefix; if (in6_recoverscope(&p->prefix, &p->prefix.sin6_addr, pr->ndpr_ifp) != 0) log(LOG_ERR, "scope error in prefix list (%s)\n", inet_ntop(AF_INET6, &p->prefix.sin6_addr, addr, sizeof(addr))); p->raflags = pr->ndpr_raf; p->prefixlen = pr->ndpr_plen; p->vltime = pr->ndpr_vltime; p->pltime = pr->ndpr_pltime; p->if_index = pr->ndpr_ifp->if_index; if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME) p->expire = 0; else { time_t maxexpire; /* XXX: we assume time_t is signed. */ maxexpire = (time_t)~(1ULL << ((sizeof(maxexpire) * 8) - 1)); if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate) { p->expire = pr->ndpr_lastupdate + pr->ndpr_vltime; } else p->expire = maxexpire; } p->refcnt = pr->ndpr_refcnt; p->flags = pr->ndpr_stateflags; p->origin = PR_ORIG_RA; advrtrs = 0; LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) { if ((void *)&sin6[advrtrs + 1] > (void *)pe) { advrtrs++; continue; } s6 = &sin6[advrtrs]; s6->sin6_family = AF_INET6; s6->sin6_len = sizeof(struct sockaddr_in6); s6->sin6_addr = pfr->router->rtaddr; in6_recoverscope(s6, &pfr->router->rtaddr, pfr->router->ifp); advrtrs++; } p->advrtrs = advrtrs; } else { advrtrs = 0; LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) advrtrs++; } advance = sizeof(*p) + sizeof(*sin6) * advrtrs; l += advance; if (p) p = (struct in6_prefix *)((caddr_t)p + advance); } if (oldp) { *oldlenp = l; /* (caddr_t)d - (caddr_t)oldp */ if (l > ol) error = ENOMEM; } else *oldlenp = l; splx(s); return (error); }