/* $NetBSD: nd6_rtr.c,v 1.7 1999/12/13 15:17:23 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 #if !(defined(__FreeBSD__) && __FreeBSD__ >= 3) #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #define SDL(s) ((struct sockaddr_dl *)s) static struct nd_defrouter *defrtrlist_update __P((struct nd_defrouter *)); static int prelist_add __P((struct nd_prefix *, struct nd_defrouter *)); static struct nd_prefix *prefix_lookup __P((struct nd_prefix *)); static struct in6_ifaddr *in6_ifadd __P((struct ifnet *, struct in6_addr *, struct in6_addr *, int)); static struct nd_pfxrouter *pfxrtr_lookup __P((struct nd_prefix *, struct nd_defrouter *)); static void pfxrtr_add __P((struct nd_prefix *, struct nd_defrouter *)); static void pfxrtr_del __P((struct nd_pfxrouter *)); static struct nd_pfxrouter *find_pfxlist_reachable_router __P((struct nd_prefix *)); static void nd6_detach_prefix __P((struct nd_prefix *)); static void nd6_attach_prefix __P((struct nd_prefix *)); static void defrouter_addifreq __P((struct ifnet *)); static void in6_init_address_ltimes __P((struct nd_prefix *ndpr, struct in6_addrlifetime *lt6, int update_vltime)); static int rt6_deleteroute __P((struct radix_node *, void *)); #if 0 extern struct timeval time; #endif extern int nd6_recalc_reachtm_interval; #if 0 static u_char bmask [] = { 0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, }; #endif struct ifnet *nd6_defifp; int nd6_defifindex; /* * Receive Router Solicitation Message - just for routers. * Router solicitation/advertisement is mostly managed by userland program * (rtadvd) so here we have no function like nd6_ra_output(). * * Based on RFC 2461 */ void nd6_rs_input(m, off, icmp6len) struct mbuf *m; int off, icmp6len; { struct ifnet *ifp = m->m_pkthdr.rcvif; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_router_solicit *nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off); struct in6_addr saddr6 = ip6->ip6_src; #if 0 struct in6_addr daddr6 = ip6->ip6_dst; #endif char *lladdr = NULL; int lladdrlen = 0; #if 0 struct sockaddr_dl *sdl = (struct sockaddr_dl *)NULL; struct llinfo_nd6 *ln = (struct llinfo_nd6 *)NULL; struct rtentry *rt = NULL; int is_newentry; #endif union nd_opts ndopts; /* If I'm not a router, ignore it. */ if (ip6_accept_rtadv != 0 || ip6_forwarding != 1) return; /* Sanity checks */ if (ip6->ip6_hlim != 255) { log(LOG_ERR, "nd6_rs_input: invalid hlim %d\n", ip6->ip6_hlim); return; } /* * Don't update the neighbor cache, if src = ::. * This indicates that the src has no IP address assigned yet. */ if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) return; icmp6len -= sizeof(*nd_rs); nd6_option_init(nd_rs + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { log(LOG_INFO, "nd6_rs_input: invalid ND option, ignored\n"); return; } if (ndopts.nd_opts_src_lladdr) { lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; } if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { log(LOG_INFO, "nd6_rs_input: lladdrlen mismatch for %s " "(if %d, RS packet %d)\n", ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2); } nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0); } /* * Receive Router Advertisement Message. * * Based on RFC 2461 * TODO: on-link bit on prefix information * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing */ void nd6_ra_input(m, off, icmp6len) struct mbuf *m; int off, icmp6len; { struct ifnet *ifp = m->m_pkthdr.rcvif; struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index]; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_router_advert *nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off); struct in6_addr saddr6 = ip6->ip6_src; #if 0 struct in6_addr daddr6 = ip6->ip6_dst; int flags = nd_ra->nd_ra_flags_reserved; int is_managed = ((flags & ND_RA_FLAG_MANAGED) != 0); int is_other = ((flags & ND_RA_FLAG_OTHER) != 0); #endif union nd_opts ndopts; struct nd_defrouter *dr; if (ip6_accept_rtadv == 0) return; if (ip6->ip6_hlim != 255) { log(LOG_ERR, "nd6_ra_input: invalid hlim %d\n", ip6->ip6_hlim); return; } if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) { log(LOG_ERR, "nd6_ra_input: src %s is not link-local\n", ip6_sprintf(&saddr6)); return; } icmp6len -= sizeof(*nd_ra); nd6_option_init(nd_ra + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { log(LOG_INFO, "nd6_ra_input: invalid ND option, ignored\n"); return; } { struct nd_defrouter dr0; u_int32_t advreachable = nd_ra->nd_ra_reachable; #if !(defined(__FreeBSD__) && __FreeBSD__ >= 3) long time_second = time.tv_sec; #endif dr0.rtaddr = saddr6; dr0.flags = nd_ra->nd_ra_flags_reserved; dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime); dr0.expire = time_second + dr0.rtlifetime; dr0.ifp = ifp; /* unspecified or not? (RFC 2461 6.3.4) */ if (advreachable) { NTOHL(advreachable); if (advreachable <= MAX_REACHABLE_TIME && ndi->basereachable != advreachable) { ndi->basereachable = advreachable; ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable); ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */ } } if (nd_ra->nd_ra_retransmit) ndi->retrans = ntohl(nd_ra->nd_ra_retransmit); if (nd_ra->nd_ra_curhoplimit) ndi->chlim = nd_ra->nd_ra_curhoplimit; dr = defrtrlist_update(&dr0); } /* * prefix */ if (ndopts.nd_opts_pi) { struct nd_opt_hdr *pt; struct nd_opt_prefix_info *pi; struct nd_prefix pr; for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi; pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end; pt = (struct nd_opt_hdr *)((caddr_t)pt + (pt->nd_opt_len << 3))) { if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION) continue; pi = (struct nd_opt_prefix_info *)pt; if (pi->nd_opt_pi_len != 4) { log(LOG_INFO, "nd6_ra_input: invalid option " "len %d for prefix information option, " "ignored\n", pi->nd_opt_pi_len); continue; } if (128 < pi->nd_opt_pi_prefix_len) { log(LOG_INFO, "nd6_ra_input: invalid prefix " "len %d for prefix information option, " "ignored\n", pi->nd_opt_pi_prefix_len); continue; } if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix) || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) { log(LOG_INFO, "nd6_ra_input: invalid prefix " "%s, ignored\n", ip6_sprintf(&pi->nd_opt_pi_prefix)); continue; } /* aggregatable unicast address, rfc2374 */ if ((pi->nd_opt_pi_prefix.s6_addr8[0] & 0xe0) == 0x20 && pi->nd_opt_pi_prefix_len != 64) { log(LOG_INFO, "nd6_ra_input: invalid prefixlen " "%d for rfc2374 prefix %s, ignored\n", pi->nd_opt_pi_prefix_len, ip6_sprintf(&pi->nd_opt_pi_prefix)); continue; } bzero(&pr, sizeof(pr)); pr.ndpr_prefix.sin6_family = AF_INET6; pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix); pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix; pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif; pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK) ? 1 : 0; pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) ? 1 : 0; pr.ndpr_plen = pi->nd_opt_pi_prefix_len; pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time); pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time); if (in6_init_prefix_ltimes(&pr)) continue; /* prefix lifetime init failed */ (void)prelist_update(&pr, dr, m); } } /* * MTU */ if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) { u_int32_t mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu); /* lower bound */ if (mtu < IPV6_MMTU) { log(LOG_INFO, "nd6_ra_input: bogus mtu option " "mtu=%d sent from %s, ignoring\n", mtu, ip6_sprintf(&ip6->ip6_src)); goto skip; } /* upper bound */ if (ndi->maxmtu) { if (mtu <= ndi->maxmtu) { int change = (ndi->linkmtu != mtu); ndi->linkmtu = mtu; if (change) /* in6_maxmtu may change */ in6_setmaxmtu(); } else { log(LOG_INFO, "nd6_ra_input: bogus mtu " "mtu=%d sent from %s; " "exceeds maxmtu %d, ignoring\n", mtu, ip6_sprintf(&ip6->ip6_src), ndi->maxmtu); } } else { log(LOG_INFO, "nd6_ra_input: mtu option " "mtu=%d sent from %s; maxmtu unknown, " "ignoring\n", mtu, ip6_sprintf(&ip6->ip6_src)); } } skip: /* * Src linkaddress */ { char *lladdr = NULL; int lladdrlen = 0; if (ndopts.nd_opts_src_lladdr) { lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; } if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { log(LOG_INFO, "nd6_ra_input: lladdrlen mismatch for %s " "(if %d, RA packet %d)\n", ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2); } nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_ADVERT, 0); /* * Installing a link-layer address might change the state of the * router's neighbor cache, which might also affect our on-link * detection of adveritsed prefixes. */ pfxlist_onlink_check(); } } /* * default router list proccessing sub routines */ void defrouter_addreq(new) struct nd_defrouter *new; { struct sockaddr_in6 def, mask, gate; int s; #if 0 register struct radix_node *rn; register struct radix_node_head *rnh; struct sockaddr *ndst; struct ifnet *ifp = new->ifp; struct ifaddr *ifa; struct rtentry *rt; extern struct pool rtentry_pool; #endif Bzero(&def, sizeof(def)); Bzero(&mask, sizeof(mask)); Bzero(&gate, sizeof(gate)); def.sin6_len = mask.sin6_len = gate.sin6_len = sizeof(struct sockaddr_in6); def.sin6_family = mask.sin6_family = gate.sin6_family = AF_INET6; gate.sin6_addr = new->rtaddr; #if 1 #ifdef __NetBSD__ s = splsoftnet(); #else s = splnet(); #endif (void)rtrequest(RTM_ADD, (struct sockaddr *)&def, (struct sockaddr *)&gate, (struct sockaddr *)&mask, RTF_GATEWAY, NULL); splx(s); return; #else ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp); if (!ifa) return; if ((rnh = rt_tables[AF_INET6]) == 0) return; #ifdef __NetBSD__ s = splsoftnet(); #else s = splnet(); #endif #ifdef __NetBSD__ rt = pool_get(&rtentry_pool, PR_NOWAIT); #else R_Malloc(rt, struct rtentry *, sizeof(*rt)); #endif if (!rt) goto bad; Bzero(rt, sizeof(*rt)); rt->rt_flags = RTF_UP | RTF_GATEWAY; if (rt_setgate(rt, (struct sockaddr *)&def, (struct sockaddr *)&gate)){ Free(rt); goto bad; } ndst = rt_key(rt); Bcopy(&def, ndst, sizeof(def)); rn = rnh->rnh_addaddr((caddr_t)ndst, (caddr_t)&mask, rnh, rt->rt_nodes); if (rn == 0) { Free(rt_key(rt)); Free(rt); goto bad; } ifa->ifa_refcnt++; rt->rt_ifa = ifa; rt->rt_ifp = ifp; rt->rt_rmx.rmx_mtu = ifa->ifa_ifp->if_mtu; /* xxx * many codes should be stolen from route.c */ bad: splx(s); return; #endif } /* Add a route to a given interface as default */ static void defrouter_addifreq(ifp) struct ifnet *ifp; { struct sockaddr_in6 def, mask; struct ifaddr *ifa; int error, flags; bzero(&def, sizeof(def)); bzero(&mask, sizeof(mask)); def.sin6_len = mask.sin6_len = sizeof(struct sockaddr_in6); def.sin6_family = mask.sin6_family = AF_INET6; /* * Search for an ifaddr beloging to the specified interface. * XXX: An IPv6 address are required to be assigned on the interface. */ if ((ifa = ifaof_ifpforaddr((struct sockaddr *)&def, ifp)) == NULL) { log(LOG_ERR, /* better error? */ "defrouter_addifreq: failed to find an ifaddr " "to install a route to interface %s\n", if_name(ifp)); return; } flags = ifa->ifa_flags; if ((ifp->if_flags & IFF_POINTOPOINT) != 0) flags &= ~RTF_CLONING; if ((error = rtrequest(RTM_ADD, (struct sockaddr *)&def, ifa->ifa_addr, (struct sockaddr *)&mask, flags, NULL)) != 0) { log(LOG_ERR, "defrouter_addifreq: failed to install a route to " "interface %s (errno = %d)\n", if_name(ifp), error); } } struct nd_defrouter * defrouter_lookup(addr, ifp) struct in6_addr *addr; struct ifnet *ifp; { struct nd_defrouter *dr; for (dr = TAILQ_FIRST(&nd_defrouter); dr; dr = TAILQ_NEXT(dr, dr_entry)) { if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) return(dr); } return(NULL); /* search failed */ } void defrouter_delreq(dr, dofree) struct nd_defrouter *dr; int dofree; { struct sockaddr_in6 def, mask, gate; Bzero(&def, sizeof(def)); Bzero(&mask, sizeof(mask)); Bzero(&gate, sizeof(gate)); def.sin6_len = mask.sin6_len = gate.sin6_len = sizeof(struct sockaddr_in6); def.sin6_family = mask.sin6_family = gate.sin6_family = AF_INET6; gate.sin6_addr = dr->rtaddr; rtrequest(RTM_DELETE, (struct sockaddr *)&def, (struct sockaddr *)&gate, (struct sockaddr *)&mask, RTF_GATEWAY, (struct rtentry **)0); if (dofree) /* XXX: necessary? */ free(dr, M_IP6NDP); } void defrtrlist_del(dr) struct nd_defrouter *dr; { struct nd_defrouter *deldr = NULL; struct nd_prefix *pr; /* * Flush all the routing table entries that use the router * as a next hop. */ if (!ip6_forwarding && ip6_accept_rtadv) { /* above is a good condition? */ rt6_flush(&dr->rtaddr, dr->ifp); } if (dr == TAILQ_FIRST(&nd_defrouter)) deldr = dr; /* The router is primary. */ TAILQ_REMOVE(&nd_defrouter, dr, dr_entry); /* * Also delete all the pointers to the router in each prefix lists. */ for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { struct nd_pfxrouter *pfxrtr; if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL) pfxrtr_del(pfxrtr); } pfxlist_onlink_check(); /* * If the router is the primary one, choose a new one. * Note that defrouter_select() will remove the current gateway * from the routing table. */ if (deldr) defrouter_select(); free(dr, M_IP6NDP); } /* * Default Router Selection according to Section 6.3.6 of RFC 2461: * 1) Routers that are reachable or probably reachable should be * preferred. * 2) When no routers on the list are known to be reachable or * probably reachable, routers SHOULD be selected in a round-robin * fashion. * 3) If the Default Router List is empty, assume that all * destinations are on-link. */ void defrouter_select() { #ifdef __NetBSD__ int s = splsoftnet(); #else int s = splnet(); #endif struct nd_defrouter *dr, anydr; struct rtentry *rt = NULL; struct llinfo_nd6 *ln = NULL; /* * Search for a (probably) reachable router from the list. */ for (dr = TAILQ_FIRST(&nd_defrouter); dr; dr = TAILQ_NEXT(dr, dr_entry)) { if ((rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) && (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && ND6_IS_LLINFO_PROBREACH(ln)) { /* Got it, and move it to the head */ TAILQ_REMOVE(&nd_defrouter, dr, dr_entry); TAILQ_INSERT_HEAD(&nd_defrouter, dr, dr_entry); break; } } if ((dr = TAILQ_FIRST(&nd_defrouter))) { /* * De-install the previous default gateway and install * a new one. * Note that if there is no reachable router in the list, * the head entry will be used anyway. * XXX: do we have to check the current routing table entry? */ bzero(&anydr, sizeof(anydr)); defrouter_delreq(&anydr, 0); defrouter_addreq(dr); } else { /* * The Default Router List is empty, so install the default * route to an inteface. * XXX: The specification does not say this mechanism should * be restricted to hosts, but this would be not useful * (even harmful) for routers. */ if (!ip6_forwarding) { /* * De-install the current default route * in advance. */ bzero(&anydr, sizeof(anydr)); defrouter_delreq(&anydr, 0); if (nd6_defifp) { /* * Install a route to the default interface * as default route. */ defrouter_addifreq(nd6_defifp); } else /* noisy log? */ log(LOG_INFO, "defrouter_select: " "there's no default router and no default" " interface\n"); } } splx(s); return; } static struct nd_defrouter * defrtrlist_update(new) struct nd_defrouter *new; { struct nd_defrouter *dr, *n; #ifdef __NetBSD__ int s = splsoftnet(); #else int s = splnet(); #endif if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) { /* entry exists */ if (new->rtlifetime == 0) { defrtrlist_del(dr); dr = NULL; } else { /* override */ dr->flags = new->flags; /* xxx flag check */ dr->rtlifetime = new->rtlifetime; dr->expire = new->expire; } splx(s); return(dr); } /* entry does not exist */ if (new->rtlifetime == 0) { splx(s); return(NULL); } n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT); if (n == NULL) { splx(s); return(NULL); } bzero(n, sizeof(*n)); *n = *new; /* * Insert the new router at the end of the Default Router List. * If there is no other router, install it anyway. Otherwise, * just continue to use the current default router. */ TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry); if (TAILQ_FIRST(&nd_defrouter) == n) defrouter_select(); splx(s); return(n); } static struct nd_pfxrouter * pfxrtr_lookup(pr, dr) struct nd_prefix *pr; struct nd_defrouter *dr; { struct nd_pfxrouter *search; for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) { if (search->router == dr) break; } return(search); } static void pfxrtr_add(pr, dr) struct nd_prefix *pr; struct nd_defrouter *dr; { struct nd_pfxrouter *new; new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT); if (new == NULL) return; bzero(new, sizeof(*new)); new->router = dr; LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry); pfxlist_onlink_check(); } static void pfxrtr_del(pfr) struct nd_pfxrouter *pfr; { LIST_REMOVE(pfr, pfr_entry); free(pfr, M_IP6NDP); } static struct nd_prefix * prefix_lookup(pr) struct nd_prefix *pr; { struct nd_prefix *search; for (search = nd_prefix.lh_first; search; search = search->ndpr_next) { if (pr->ndpr_ifp == search->ndpr_ifp && pr->ndpr_plen == search->ndpr_plen && in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr, &search->ndpr_prefix.sin6_addr, pr->ndpr_plen) ) { break; } } return(search); } static int prelist_add(pr, dr) struct nd_prefix *pr; struct nd_defrouter *dr; { struct nd_prefix *new; int i, s; new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT); if (new == NULL) return ENOMEM; bzero(new, sizeof(*new)); *new = *pr; /* initilization */ new->ndpr_statef_onlink = pr->ndpr_statef_onlink; LIST_INIT(&new->ndpr_advrtrs); in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen); /* make prefix in the canonical form */ for (i = 0; i < 4; i++) new->ndpr_prefix.sin6_addr.s6_addr32[i] &= new->ndpr_mask.s6_addr32[i]; /* xxx ND_OPT_PI_FLAG_ONLINK processing */ #ifdef __NetBSD__ s = splsoftnet(); #else s = splnet(); #endif /* link ndpr_entry to nd_prefix list */ LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry); splx(s); if (dr) pfxrtr_add(new, dr); return 0; } void prelist_remove(pr) struct nd_prefix *pr; { struct nd_pfxrouter *pfr, *next; int s; #ifdef __NetBSD__ s = splsoftnet(); #else s = splnet(); #endif /* unlink ndpr_entry from nd_prefix list */ LIST_REMOVE(pr, ndpr_entry); splx(s); /* free list of routers that adversed the prefix */ for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) { next = pfr->pfr_next; free(pfr, M_IP6NDP); } free(pr, M_IP6NDP); pfxlist_onlink_check(); } /* * NOTE: We set address lifetime to keep * address lifetime <= prefix lifetime * invariant. This is to simplify on-link determination code. * If onlink determination is udated, this routine may have to be updated too. */ int prelist_update(new, dr, m) struct nd_prefix *new; struct nd_defrouter *dr; /* may be NULL */ struct mbuf *m; { struct in6_ifaddr *ia6 = NULL; struct nd_prefix *pr; #ifdef __NetBSD__ int s = splsoftnet(); #else int s = splnet(); #endif int error = 0; int auth; struct in6_addrlifetime *lt6; auth = 0; if (m) { /* * Authenticity for NA consists authentication for * both IP header and IP datagrams, doesn't it ? */ #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM) auth = (m->m_flags & M_AUTHIPHDR && m->m_flags & M_AUTHIPDGM) ? 1 : 0; #endif } if ((pr = prefix_lookup(new)) != NULL) { if (pr->ndpr_ifp != new->ndpr_ifp) { error = EADDRNOTAVAIL; goto end; } /* update prefix information */ pr->ndpr_flags = new->ndpr_flags; pr->ndpr_vltime = new->ndpr_vltime; pr->ndpr_pltime = new->ndpr_pltime; pr->ndpr_preferred = new->ndpr_preferred; pr->ndpr_expire = new->ndpr_expire; /* * RFC 2462 5.5.3 (d) or (e) * We got a prefix which we have seen in the past. */ if (!new->ndpr_raf_auto) goto noautoconf1; if (IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr)) ia6 = NULL; else ia6 = in6ifa_ifpwithaddr(pr->ndpr_ifp, &pr->ndpr_addr); if (ia6 == NULL) { /* * Special case: * (1) We have seen the prefix advertised before, but * we have never performed autoconfig for this prefix. * This is because Autonomous bit was 0 previously, or * autoconfig failed due to some other reasons. * (2) We have seen the prefix advertised before and * we have performed autoconfig in the past, but * we seem to have no interface address right now. * This is because the interface address have expired. * * This prefix is fresh, with respect to autoconfig * process. * * Add an address based on RFC 2462 5.5.3 (d). */ ia6 = in6_ifadd(pr->ndpr_ifp, &pr->ndpr_prefix.sin6_addr, &pr->ndpr_addr, new->ndpr_plen); if (!ia6) { error = EADDRNOTAVAIL; log(LOG_ERR, "prelist_update: failed to add a " "new address\n"); goto noautoconf1; } lt6 = &ia6->ia6_lifetime; /* address lifetime <= prefix lifetime */ lt6->ia6t_vltime = new->ndpr_vltime; lt6->ia6t_pltime = new->ndpr_pltime; in6_init_address_ltimes(new, lt6, 1); } else { #define TWOHOUR (120*60) /* * We have seen the prefix before, and we have added * interface address in the past. We still have * the interface address assigned. * * update address lifetime based on RFC 2462 * 5.5.3 (e). */ int update = 0; lt6 = &ia6->ia6_lifetime; #if 0 /* RFC 2462 5.5.3 (e) */ lt6->ia6t_pltime = new->ndpr_pltime; if (TWOHOUR < new->ndpr_vltime || lt6pr->nd < new->ndpr_vltime) { lt6->ia6t_vltime = new->ndpr_vltime; update++; } else if (auth && lt6->ia6t_vltime <= TWOHOUR0 && new->ndpr_vltime <= lt6->ia6t_vltime) { lt6->ia6t_vltime = new->ndpr_vltime; update++; } else { lt6->ia6t_vltime = TWOHOUR; update++; } /* 2 hour rule is not imposed for pref lifetime */ new->ndpr_apltime = new->ndpr_pltime; lt6->ia6t_pltime = new->ndpr_pltime; #else /* update from Jim Bound, (ipng 6712) */ if (TWOHOUR < new->ndpr_vltime || lt6->ia6t_vltime < new->ndpr_vltime) { lt6->ia6t_vltime = new->ndpr_vltime; update++; } else if (auth) { lt6->ia6t_vltime = new->ndpr_vltime; update++; } /* jim bound rule is not imposed for pref lifetime */ lt6->ia6t_pltime = new->ndpr_pltime; #endif in6_init_address_ltimes(new, lt6, update); } noautoconf1: #if 0 /* address lifetime expire processing, RFC 2462 5.5.4. */ if (pr->ndpr_preferred && pr->ndpr_preferred < time_second) { struct in6_ifaddr *ia6; ia6 = in6ifa_ifpwithaddr(pr->ndpr_ifp, &pr->ndpr_addr); if (ia6) ia6->ia6_flags &= ~IN6_IFF_DEPRECATED; } #endif if (dr && pfxrtr_lookup(pr, dr) == NULL) pfxrtr_add(pr, dr); } else { int error_tmp; if (new->ndpr_vltime == 0) goto end; bzero(&new->ndpr_addr, sizeof(struct in6_addr)); /* * RFC 2462 5.5.3 (d) * We got a fresh prefix. Perform some sanity checks * and add an interface address by appending interface ID * to the advertised prefix. */ if (!new->ndpr_raf_auto) goto noautoconf2; ia6 = in6_ifadd(new->ndpr_ifp, &new->ndpr_prefix.sin6_addr, &new->ndpr_addr, new->ndpr_plen); if (!ia6) { error = EADDRNOTAVAIL; log(LOG_ERR, "prelist_update: " "failed to add a new address\n"); goto noautoconf2; } /* set onlink bit if an interface route is configured */ new->ndpr_statef_onlink = (ia6->ia_flags & IFA_ROUTE) ? 1 : 0; lt6 = &ia6->ia6_lifetime; /* address lifetime <= prefix lifetime */ lt6->ia6t_vltime = new->ndpr_vltime; lt6->ia6t_pltime = new->ndpr_pltime; in6_init_address_ltimes(new, lt6, 1); noautoconf2: error_tmp = prelist_add(new, dr); error = error_tmp ? error_tmp : error; } end: splx(s); return error; } /* * A supplement function used in the on-link detection below; * detect if a given prefix has a (probably) reachable advertising router. * XXX: lengthy function name... */ static struct nd_pfxrouter * find_pfxlist_reachable_router(pr) struct nd_prefix *pr; { struct nd_pfxrouter *pfxrtr; struct rtentry *rt; struct llinfo_nd6 *ln; for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr; pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) { if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0, pfxrtr->router->ifp)) && (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && ND6_IS_LLINFO_PROBREACH(ln)) break; /* found */ } return(pfxrtr); } /* * Check if each prefix in the prefix list has at least one available router * that advertised the prefix (A router is "available" if its neighbor cache * entry has reachable or probably reachable). * If the check fails, the prefix may be off-link, because, for example, * we have moved from the network but the lifetime of the prefix has not * been expired yet. So we should not use the prefix if there is another * prefix that has an available router. * But if there is no prefix that has an available router, we still regards * all the prefixes as on-link. This is because we can't tell if all the * routers are simply dead or if we really moved from the network and there * is no router around us. */ void pfxlist_onlink_check() { struct nd_prefix *pr; /* * Check if there is a prefix that has a reachable advertising * router. */ for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { if (find_pfxlist_reachable_router(pr)) break; } if (pr) { /* * There is at least one prefix that has a reachable router. * First, detach prefixes which has no reachable advertising * router and then attach other prefixes. * The order is important since an attached prefix and a * detached prefix may have a same interface route. */ for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { if (find_pfxlist_reachable_router(pr) == NULL && pr->ndpr_statef_onlink) { pr->ndpr_statef_onlink = 0; nd6_detach_prefix(pr); } } for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { if (find_pfxlist_reachable_router(pr) && pr->ndpr_statef_onlink == 0) nd6_attach_prefix(pr); } } else { /* there is no prefix that has a reachable router */ for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) if (pr->ndpr_statef_onlink == 0) nd6_attach_prefix(pr); } } static void nd6_detach_prefix(pr) struct nd_prefix *pr; { struct in6_ifaddr *ia6; struct sockaddr_in6 sa6, mask6; /* * Delete the interface route associated with the prefix. */ bzero(&sa6, sizeof(sa6)); sa6.sin6_family = AF_INET6; sa6.sin6_len = sizeof(sa6); bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr, sizeof(struct in6_addr)); bzero(&mask6, sizeof(mask6)); mask6.sin6_family = AF_INET6; mask6.sin6_len = sizeof(sa6); bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr)); { int e; e = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL, (struct sockaddr *)&mask6, 0, NULL); if (e) { log(LOG_ERR, "nd6_detach_prefix: failed to delete route: " "%s/%d (errno = %d)\n", ip6_sprintf(&sa6.sin6_addr), pr->ndpr_plen, e); } } /* * Mark the address derived from the prefix detached so that * it won't be used as a source address for a new connection. */ if (IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr)) ia6 = NULL; else ia6 = in6ifa_ifpwithaddr(pr->ndpr_ifp, &pr->ndpr_addr); if (ia6) ia6->ia6_flags |= IN6_IFF_DETACHED; } static void nd6_attach_prefix(pr) struct nd_prefix *pr; { struct ifaddr *ifa; struct in6_ifaddr *ia6; /* * Add the interface route associated with the prefix(if necessary) * Should we consider if the L bit is set in pr->ndpr_flags? */ ifa = ifaof_ifpforaddr((struct sockaddr *)&pr->ndpr_prefix, pr->ndpr_ifp); if (ifa == NULL) { log(LOG_ERR, "nd6_attach_prefix: failed to find any ifaddr" " to add route for a prefix(%s/%d)\n", ip6_sprintf(&pr->ndpr_addr), pr->ndpr_plen); } else { int e; struct sockaddr_in6 mask6; bzero(&mask6, sizeof(mask6)); mask6.sin6_family = AF_INET6; mask6.sin6_len = sizeof(mask6); mask6.sin6_addr = pr->ndpr_mask; e = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix, ifa->ifa_addr, (struct sockaddr *)&mask6, ifa->ifa_flags, NULL); if (e == 0) pr->ndpr_statef_onlink = 1; else { log(LOG_ERR, "nd6_attach_prefix: failed to add route for" " a prefix(%s/%d), errno = %d\n", ip6_sprintf(&pr->ndpr_addr), pr->ndpr_plen, e); } } /* * Now the address derived from the prefix can be used as a source * for a new connection, so clear the detached flag. */ if (IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr)) ia6 = NULL; else ia6 = in6ifa_ifpwithaddr(pr->ndpr_ifp, &pr->ndpr_addr); if (ia6) { ia6->ia6_flags &= ~IN6_IFF_DETACHED; if (pr->ndpr_statef_onlink) ia6->ia_flags |= IFA_ROUTE; } } static struct in6_ifaddr * in6_ifadd(ifp, in6, addr, prefixlen) struct ifnet *ifp; struct in6_addr *in6; struct in6_addr *addr; int prefixlen; /* prefix len of the new prefix in "in6" */ { struct ifaddr *ifa; struct in6_ifaddr *ia, *ib, *oia; int s, error; struct in6_addr mask; in6_len2mask(&mask, prefixlen); /* find link-local address (will be interface ID) */ ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp); if (ifa) ib = (struct in6_ifaddr *)ifa; else return NULL; #if 0 /* don't care link local addr state, and always do DAD */ /* if link-local address is not eligible, do not autoconfigure. */ if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY) { printf("in6_ifadd: link-local address not ready\n"); return NULL; } #endif /* prefixlen + ifidlen must be equal to 128 */ if (prefixlen != in6_mask2len(&ib->ia_prefixmask.sin6_addr)) { log(LOG_ERR, "in6_ifadd: wrong prefixlen for %s" "(prefix=%d ifid=%d)\n", if_name(ifp), prefixlen, 128 - in6_mask2len(&ib->ia_prefixmask.sin6_addr)); return NULL; } /* make ifaddr */ ia = (struct in6_ifaddr *)malloc(sizeof(*ia), M_IFADDR, M_DONTWAIT); if (ia == NULL) { printf("ENOBUFS in in6_ifadd %d\n", __LINE__); return NULL; } bzero((caddr_t)ia, sizeof(*ia)); ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr; ia->ia_ifa.ifa_netmask = (struct sockaddr *)&ia->ia_prefixmask; ia->ia_ifp = ifp; /* link to in6_ifaddr */ if ((oia = in6_ifaddr) != NULL) { for( ; oia->ia_next; oia = oia->ia_next) continue; oia->ia_next = ia; } else in6_ifaddr = ia; /* link to if_addrlist */ if (ifp->if_addrlist.tqh_first != NULL) { TAILQ_INSERT_TAIL(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list); } #if 0 else { /* * this should not be the case because there is at least one * link-local address(see the beginning of the function). */ TAILQ_INIT(&ifp->if_addrlist); } #endif /* new address */ ia->ia_addr.sin6_len = sizeof(struct sockaddr_in6); ia->ia_addr.sin6_family = AF_INET6; /* prefix */ bcopy(in6, &ia->ia_addr.sin6_addr, sizeof(ia->ia_addr.sin6_addr)); ia->ia_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0]; ia->ia_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1]; ia->ia_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2]; ia->ia_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3]; /* interface ID */ ia->ia_addr.sin6_addr.s6_addr32[0] |= (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]); ia->ia_addr.sin6_addr.s6_addr32[1] |= (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]); ia->ia_addr.sin6_addr.s6_addr32[2] |= (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]); ia->ia_addr.sin6_addr.s6_addr32[3] |= (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]); /* new prefix */ ia->ia_prefixmask.sin6_len = sizeof(struct sockaddr_in6); ia->ia_prefixmask.sin6_family = AF_INET6; bcopy(&mask, &ia->ia_prefixmask.sin6_addr, sizeof(ia->ia_prefixmask.sin6_addr)); /* same routine */ ia->ia_ifa.ifa_rtrequest = (ifp->if_type == IFT_PPP) ? nd6_p2p_rtrequest : nd6_rtrequest; ia->ia_ifa.ifa_flags |= RTF_CLONING; ia->ia_ifa.ifa_metric = ifp->if_metric; /* add interface route */ if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_UP|RTF_CLONING))) { log(LOG_NOTICE, "in6_ifadd: failed to add an interface route " "for %s/%d on %s, errno = %d\n", ip6_sprintf(&ia->ia_addr.sin6_addr), prefixlen, if_name(ifp), error); } else ia->ia_flags |= IFA_ROUTE; *addr = ia->ia_addr.sin6_addr; if (ifp->if_flags & IFF_MULTICAST) { int error; /* not used */ struct in6_addr sol6; #if !(defined(__FreeBSD__) && __FreeBSD__ >= 3) /* Restore saved multicast addresses(if any). */ in6_restoremkludge(ia, ifp); #endif /* join solicited node multicast address */ bzero(&sol6, sizeof(sol6)); sol6.s6_addr16[0] = htons(0xff02); sol6.s6_addr16[1] = htons(ifp->if_index); sol6.s6_addr32[1] = 0; sol6.s6_addr32[2] = htonl(1); sol6.s6_addr32[3] = ia->ia_addr.sin6_addr.s6_addr32[3]; sol6.s6_addr8[12] = 0xff; (void)in6_addmulti(&sol6, ifp, &error); } ia->ia6_flags |= IN6_IFF_TENTATIVE; /* * To make the interface up. Only AF_INET6 in ia is used... */ s = splimp(); if (ifp->if_ioctl && (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia)) { splx(s); return NULL; } splx(s); /* Perform DAD, if needed. */ nd6_dad_start((struct ifaddr *)ia, NULL); return ia; } int in6_ifdel(ifp, in6) struct ifnet *ifp; struct in6_addr *in6; { struct in6_ifaddr *ia = (struct in6_ifaddr *)NULL; struct in6_ifaddr *oia = (struct in6_ifaddr *)NULL; if (!ifp) return -1; ia = in6ifa_ifpwithaddr(ifp, in6); if (!ia) return -1; if (ifp->if_flags & IFF_MULTICAST) { /* * delete solicited multicast addr for deleting host id */ struct in6_multi *in6m; struct in6_addr llsol; bzero(&llsol, sizeof(struct in6_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_addr32[3] = ia->ia_addr.sin6_addr.s6_addr32[3]; llsol.s6_addr8[12] = 0xff; IN6_LOOKUP_MULTI(llsol, ifp, in6m); if (in6m) in6_delmulti(in6m); } if (ia->ia_flags & IFA_ROUTE) { rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); ia->ia_flags &= ~IFA_ROUTE; } TAILQ_REMOVE(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list); /* lladdr is never deleted */ oia = ia; if (oia == (ia = in6_ifaddr)) in6_ifaddr = ia->ia_next; else { while (ia->ia_next && (ia->ia_next != oia)) ia = ia->ia_next; if (ia->ia_next) ia->ia_next = oia->ia_next; else return -1; } #if !(defined(__FreeBSD__) && __FreeBSD__ >= 3) in6_savemkludge(oia); #endif IFAFREE((&oia->ia_ifa)); /* xxx rtrequest(RTM_DELETE, (struct sockaddr *)&ia->ia_addr, (struct sockaddr *)0 (struct sockaddr *)&ia->ia_prefixmask, RTF_UP|RTF_CLONING, (struct rtentry **)0); */ return 0; } int in6_init_prefix_ltimes(struct nd_prefix *ndpr) { #if !(defined(__FreeBSD__) && __FreeBSD__ >= 3) long time_second = time.tv_sec; #endif /* check if preferred lifetime > valid lifetime */ if (ndpr->ndpr_pltime > ndpr->ndpr_vltime) { log(LOG_INFO, "in6_init_prefix_ltimes: preferred lifetime" "(%d) is greater than valid lifetime(%d)\n", (u_int)ndpr->ndpr_pltime, (u_int)ndpr->ndpr_vltime); return (EINVAL); } if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME) ndpr->ndpr_preferred = 0; else ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime; if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME) ndpr->ndpr_expire = 0; else ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime; return 0; } static void in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6, int update_vltime) { #if !(defined(__FreeBSD__) && __FreeBSD__ >= 3) long time_second = time.tv_sec; #endif /* Valid lifetime must not be updated unless explicitly specified. */ if (update_vltime) { /* init ia6t_expire */ if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME) lt6->ia6t_expire = 0; else { lt6->ia6t_expire = time_second; lt6->ia6t_expire += lt6->ia6t_vltime; } /* Ensure addr lifetime <= prefix lifetime. */ if (new->ndpr_expire && lt6->ia6t_expire && new->ndpr_expire < lt6->ia6t_expire) lt6->ia6t_expire = new->ndpr_expire; } /* init ia6t_preferred */ if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME) lt6->ia6t_preferred = 0; else { lt6->ia6t_preferred = time_second; lt6->ia6t_preferred += lt6->ia6t_pltime; } /* Ensure addr lifetime <= prefix lifetime. */ if (new->ndpr_preferred && lt6->ia6t_preferred && new->ndpr_preferred < lt6->ia6t_preferred) lt6->ia6t_preferred = new->ndpr_preferred; } /* * Delete all the routing table entries that use the specified gateway. * XXX: this function causes search through all entries of routing table, so * it shouldn't be called when acting as a router. */ void rt6_flush(gateway, ifp) struct in6_addr *gateway; struct ifnet *ifp; { struct radix_node_head *rnh = rt_tables[AF_INET6]; int s = splsoftnet(); /* We'll care only link-local addresses */ if (!IN6_IS_ADDR_LINKLOCAL(gateway)) { splx(s); return; } /* XXX: hack for KAME's link-local address kludge */ gateway->s6_addr16[1] = htons(ifp->if_index); rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway); splx(s); } static int rt6_deleteroute(rn, arg) struct radix_node *rn; void *arg; { #define SIN6(s) ((struct sockaddr_in6 *)s) struct rtentry *rt = (struct rtentry *)rn; struct in6_addr *gate = (struct in6_addr *)arg; if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6) return(0); if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr)) return(0); /* * We delete only host route. This means, in particular, we don't * delete default route. */ if ((rt->rt_flags & RTF_HOST) == 0) return(0); return(rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0)); #undef SIN6 } int nd6_setdefaultiface(ifindex) int ifindex; { int error = 0; if (ifindex < 0 || if_index < ifindex) return(EINVAL); if (nd6_defifindex != ifindex) { nd6_defifindex = ifindex; if (nd6_defifindex > 0) nd6_defifp = ifindex2ifnet[nd6_defifindex]; else nd6_defifp = NULL; /* * If the Default Router List is empty, install a route * to the specified interface as default or remove the default * route when the default interface becomes canceled. * The check for the queue is actually redundant, but * we do this here to avoid re-install the default route * if the list is NOT empty. */ if (TAILQ_FIRST(&nd_defrouter) == NULL) defrouter_select(); } return(error); }