/* $NetBSD: nd6_rtr.c,v 1.139 2018/04/24 08:07:05 maxv Exp $ */ /* $KAME: nd6_rtr.c,v 1.95 2001/02/07 08:09:47 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 __KERNEL_RCSID(0, "$NetBSD: nd6_rtr.c,v 1.139 2018/04/24 08:07:05 maxv Exp $"); #ifdef _KERNEL_OPT #include "opt_net_mpsafe.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int rtpref(struct nd_defrouter *); static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *); static int prelist_update(struct nd_prefixctl *, struct nd_defrouter *, struct mbuf *, int); static struct in6_ifaddr *in6_ifadd(struct nd_prefixctl *, int, struct psref *); static struct nd_pfxrouter *pfxrtr_lookup(struct nd_prefix *, struct nd_defrouter *); static void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *); static void pfxrtr_del(struct nd_pfxrouter *); static struct nd_pfxrouter *find_pfxlist_reachable_router (struct nd_prefix *); static void defrouter_addreq(struct nd_defrouter *); static void defrouter_delreq(struct nd_defrouter *); static int in6_init_prefix_ltimes(struct nd_prefix *); static void in6_init_address_ltimes(struct nd_prefix *, struct in6_addrlifetime *); static void purge_detached(struct ifnet *); static int rt6_deleteroute_matcher(struct rtentry *, void *); static int nd6_prelist_add(struct nd_prefixctl *, struct nd_defrouter *, struct nd_prefix **); static int nd6_prefix_onlink(struct nd_prefix *); static int nd6_prefix_offlink(struct nd_prefix *); static struct nd_prefix *nd6_prefix_lookup(struct nd_prefixctl *); extern int nd6_recalc_reachtm_interval; int ip6_use_tempaddr = 0; int ip6_desync_factor; u_int32_t ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME; u_int32_t ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME; int ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE; int nd6_numroutes = 0; /* RTPREF_MEDIUM has to be 0! */ #define RTPREF_HIGH 1 #define RTPREF_MEDIUM 0 #define RTPREF_LOW (-1) #define RTPREF_RESERVED (-2) #define RTPREF_INVALID (-3) /* internal */ static inline bool nd6_is_llinfo_probreach(struct nd_defrouter *dr) { struct llentry *ln = NULL; ln = nd6_lookup(&dr->rtaddr, dr->ifp, false); if (ln == NULL) return false; if (!ND6_IS_LLINFO_PROBREACH(ln)) { LLE_RUNLOCK(ln); return false; } LLE_RUNLOCK(ln); return true; } /* * Receive Router Solicitation Message - just for routers. * Router solicitation/advertisement is mostly managed by a userland program * (rtadvd) so here we have no function like nd6_ra_output(). * * Based on RFC 2461 */ void nd6_rs_input(struct mbuf *m, int off, int icmp6len) { struct ifnet *ifp; struct nd_ifinfo *ndi; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_router_solicit *nd_rs; struct in6_addr saddr6 = ip6->ip6_src; char *lladdr = NULL; int lladdrlen = 0; union nd_opts ndopts; struct psref psref; char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; ifp = m_get_rcvif_psref(m, &psref); if (ifp == NULL) goto freeit; ndi = ND_IFINFO(ifp); /* If I'm not a router, ignore it. */ if (nd6_accepts_rtadv(ndi) || !ip6_forwarding) goto freeit; /* Sanity checks */ if (ip6->ip6_hlim != 255) { nd6log(LOG_ERR, "invalid hlim (%d) from %s to %s on %s\n", ip6->ip6_hlim, IN6_PRINT(ip6bufs, &ip6->ip6_src), IN6_PRINT(ip6bufd, &ip6->ip6_dst), if_name(ifp)); goto bad; } /* * 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)) goto freeit; IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len); if (nd_rs == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); return; } icmp6len -= sizeof(*nd_rs); nd6_option_init(nd_rs + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { nd6log(LOG_INFO, "invalid ND option, ignored\n"); /* nd6_options have incremented stats */ goto freeit; } 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) { nd6log(LOG_INFO, "lladdrlen mismatch for %s " "(if %d, RS packet %d)\n", IN6_PRINT(ip6bufs, &saddr6), ifp->if_addrlen, lladdrlen - 2); goto bad; } nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0); freeit: m_put_rcvif_psref(ifp, &psref); m_freem(m); return; bad: ICMP6_STATINC(ICMP6_STAT_BADRS); m_put_rcvif_psref(ifp, &psref); m_freem(m); } /* * 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(struct mbuf *m, int off, int icmp6len) { struct ifnet *ifp; struct nd_ifinfo *ndi; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_router_advert *nd_ra; 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 int mcast = 0; union nd_opts ndopts; struct nd_defrouter *dr; struct psref psref; char ip6buf[INET6_ADDRSTRLEN], ip6buf2[INET6_ADDRSTRLEN]; ifp = m_get_rcvif_psref(m, &psref); if (ifp == NULL) goto freeit; ndi = ND_IFINFO(ifp); /* * We only accept RAs when * the system-wide variable allows the acceptance, and the * per-interface variable allows RAs on the receiving interface. */ if (!nd6_accepts_rtadv(ndi)) goto freeit; if (ip6->ip6_hlim != 255) { nd6log(LOG_ERR, "invalid hlim (%d) from %s to %s on %s\n", ip6->ip6_hlim, IN6_PRINT(ip6buf, &ip6->ip6_src), IN6_PRINT(ip6buf2, &ip6->ip6_dst), if_name(ifp)); goto bad; } if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) { nd6log(LOG_ERR, "src %s is not link-local\n", IN6_PRINT(ip6buf, &saddr6)); goto bad; } IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len); if (nd_ra == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); m_put_rcvif_psref(ifp, &psref); return; } icmp6len -= sizeof(*nd_ra); nd6_option_init(nd_ra + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { nd6log(LOG_INFO, "invalid ND option, ignored\n"); /* nd6_options have incremented stats */ goto freeit; } { struct nd_defrouter drtr; u_int32_t advreachable = nd_ra->nd_ra_reachable; /* remember if this is a multicasted advertisement */ if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) mcast = 1; memset(&drtr, 0, sizeof(drtr)); drtr.rtaddr = saddr6; drtr.flags = nd_ra->nd_ra_flags_reserved; drtr.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime); drtr.expire = time_uptime + drtr.rtlifetime; drtr.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) { if (ndi->chlim < nd_ra->nd_ra_curhoplimit) ndi->chlim = nd_ra->nd_ra_curhoplimit; else if (ndi->chlim != nd_ra->nd_ra_curhoplimit) log(LOG_ERR, "nd_ra_input: lower CurHopLimit sent from " "%s on %s (current=%d, received=%d), ignored\n", IN6_PRINT(ip6buf, &ip6->ip6_src), if_name(ifp), ndi->chlim, nd_ra->nd_ra_curhoplimit); } IFNET_LOCK(ifp); ND6_WLOCK(); dr = defrtrlist_update(&drtr); } /* * prefix */ if (ndopts.nd_opts_pi) { struct nd_opt_hdr *pt; struct nd_opt_prefix_info *pi = NULL; struct nd_prefixctl prc; 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 *)((char *)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) { nd6log(LOG_INFO, "invalid option " "len %d for prefix information option, " "ignored\n", pi->nd_opt_pi_len); continue; } if (128 < pi->nd_opt_pi_prefix_len) { nd6log(LOG_INFO, "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)) { nd6log(LOG_INFO, "invalid prefix %s, ignored\n", IN6_PRINT(ip6buf, &pi->nd_opt_pi_prefix)); continue; } memset(&prc, 0, sizeof(prc)); sockaddr_in6_init(&prc.ndprc_prefix, &pi->nd_opt_pi_prefix, 0, 0, 0); prc.ndprc_ifp = ifp; prc.ndprc_raf_onlink = (pi->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK) ? 1 : 0; prc.ndprc_raf_auto = (pi->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) ? 1 : 0; prc.ndprc_plen = pi->nd_opt_pi_prefix_len; prc.ndprc_vltime = ntohl(pi->nd_opt_pi_valid_time); prc.ndprc_pltime = ntohl(pi->nd_opt_pi_preferred_time); (void)prelist_update(&prc, dr, m, mcast); } } ND6_UNLOCK(); IFNET_UNLOCK(ifp); /* * MTU */ if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) { u_long mtu; u_long maxmtu; mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu); /* lower bound */ if (mtu < IPV6_MMTU) { nd6log(LOG_INFO, "bogus mtu option " "mtu=%lu sent from %s, ignoring\n", mtu, IN6_PRINT(ip6buf, &ip6->ip6_src)); goto skip; } /* upper bound */ maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu) ? ndi->maxmtu : ifp->if_mtu; if (mtu <= maxmtu) { int change = (ndi->linkmtu != mtu); ndi->linkmtu = mtu; if (change) /* in6_maxmtu may change */ in6_setmaxmtu(); } else { nd6log(LOG_INFO, "bogus mtu mtu=%lu sent from %s; " "exceeds maxmtu %lu, ignoring\n", mtu, IN6_PRINT(ip6buf, &ip6->ip6_src), maxmtu); } } skip: /* * Source link layer address */ { 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) { nd6log(LOG_INFO, "lladdrlen mismatch for %s " "(if %d, RA packet %d)\n", IN6_PRINT(ip6buf, &saddr6), ifp->if_addrlen, lladdrlen - 2); goto bad; } 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. */ ND6_WLOCK(); nd6_pfxlist_onlink_check(); ND6_UNLOCK(); } freeit: m_put_rcvif_psref(ifp, &psref); m_freem(m); return; bad: ICMP6_STATINC(ICMP6_STAT_BADRA); m_put_rcvif_psref(ifp, &psref); m_freem(m); } /* * default router list processing sub routines */ static void defrouter_addreq(struct nd_defrouter *newdr) { union { struct sockaddr_in6 sin6; struct sockaddr sa; } def, mask, gate; #ifndef NET_MPSAFE int s; #endif int error; memset(&def, 0, sizeof(def)); memset(&mask, 0, sizeof(mask)); memset(&gate, 0,sizeof(gate)); /* for safety */ def.sin6.sin6_len = mask.sin6.sin6_len = gate.sin6.sin6_len = sizeof(struct sockaddr_in6); def.sin6.sin6_family = mask.sin6.sin6_family = gate.sin6.sin6_family = AF_INET6; gate.sin6.sin6_addr = newdr->rtaddr; #ifndef SCOPEDROUTING gate.sin6.sin6_scope_id = 0; /* XXX */ #endif #ifndef NET_MPSAFE s = splsoftnet(); #endif error = rtrequest_newmsg(RTM_ADD, &def.sa, &gate.sa, &mask.sa, RTF_GATEWAY); if (error == 0) { nd6_numroutes++; newdr->installed = 1; } #ifndef NET_MPSAFE splx(s); #endif return; } struct nd_defrouter * nd6_defrouter_lookup(const struct in6_addr *addr, struct ifnet *ifp) { struct nd_defrouter *dr; ND6_ASSERT_LOCK(); ND_DEFROUTER_LIST_FOREACH(dr) { if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) break; } return dr; /* search failed */ } void nd6_defrtrlist_del(struct nd_defrouter *dr, struct in6_ifextra *ext) { struct nd_defrouter *deldr = NULL; struct nd_prefix *pr; struct nd_ifinfo *ndi; ND6_ASSERT_WLOCK(); if (ext == NULL) ext = dr->ifp->if_afdata[AF_INET6]; /* detach already in progress, can not do anything */ if (ext == NULL) return; ndi = ext->nd_ifinfo; /* * Flush all the routing table entries that use the router * as a next hop. */ /* XXX: better condition? */ if (!ip6_forwarding && nd6_accepts_rtadv(ndi)) nd6_rt_flush(&dr->rtaddr, dr->ifp); if (dr->installed) { deldr = dr; defrouter_delreq(dr); } ND_DEFROUTER_LIST_REMOVE(dr); /* * Also delete all the pointers to the router in each prefix lists. */ ND_PREFIX_LIST_FOREACH(pr) { struct nd_pfxrouter *pfxrtr; if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL) pfxrtr_del(pfxrtr); } nd6_pfxlist_onlink_check(); /* * If the router is the primary one, choose a new one. * Note that nd6_defrouter_select() will remove the current gateway * from the routing table. */ if (deldr) nd6_defrouter_select(); ext->ndefrouters--; if (ext->ndefrouters < 0) { log(LOG_WARNING, "nd6_defrtrlist_del: negative count on %s\n", dr->ifp->if_xname); } free(dr, M_IP6NDP); } /* * Remove the default route for a given router. * This is just a subroutine function for nd6_defrouter_select(), and should * not be called from anywhere else. */ static void defrouter_delreq(struct nd_defrouter *dr) { union { struct sockaddr_in6 sin6; struct sockaddr sa; } def, mask, gw; int error; memset(&def, 0, sizeof(def)); memset(&mask, 0, sizeof(mask)); memset(&gw, 0, sizeof(gw)); /* for safety */ def.sin6.sin6_len = mask.sin6.sin6_len = gw.sin6.sin6_len = sizeof(struct sockaddr_in6); def.sin6.sin6_family = mask.sin6.sin6_family = gw.sin6.sin6_family = AF_INET6; gw.sin6.sin6_addr = dr->rtaddr; #ifndef SCOPEDROUTING gw.sin6.sin6_scope_id = 0; /* XXX */ #endif error = rtrequest_newmsg(RTM_DELETE, &def.sa, &gw.sa, &mask.sa, RTF_GATEWAY); if (error == 0) nd6_numroutes--; dr->installed = 0; } /* * remove all default routes from default router list */ void nd6_defrouter_reset(void) { struct nd_defrouter *dr; ND6_ASSERT_WLOCK(); ND_DEFROUTER_LIST_FOREACH(dr) defrouter_delreq(dr); /* * XXX should we also nuke any default routers in the kernel, by * going through them by rtalloc1()? */ } /* * Default Router Selection according to Section 6.3.6 of RFC 2461 and * draft-ietf-ipngwg-router-selection: * 1) Routers that are reachable or probably reachable should be preferred. * If we have more than one (probably) reachable router, prefer ones * with the highest router preference. * 2) When no routers on the list are known to be reachable or * probably reachable, routers SHOULD be selected in a round-robin * fashion, regardless of router preference values. * 3) If the Default Router List is empty, assume that all * destinations are on-link. * * We assume nd_defrouter is sorted by router preference value. * Since the code below covers both with and without router preference cases, * we do not need to classify the cases by ifdef. * * At this moment, we do not try to install more than one default router, * even when the multipath routing is available, because we're not sure about * the benefits for stub hosts comparing to the risk of making the code * complicated and the possibility of introducing bugs. */ void nd6_defrouter_select(void) { struct nd_ifinfo *ndi; struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL; ND6_ASSERT_WLOCK(); /* * This function should be called only when acting as an autoconfigured * host. Although the remaining part of this function is not effective * if the node is not an autoconfigured host, we explicitly exclude * such cases here for safety. */ if (ip6_forwarding) { nd6log(LOG_WARNING, "called unexpectedly (forwarding=%d, " "accept_rtadv=%d)\n", ip6_forwarding, ip6_accept_rtadv); return; } /* * Let's handle easy case (3) first: * If default router list is empty, there's nothing to be done. */ if (ND_DEFROUTER_LIST_EMPTY()) return; /* * Search for a (probably) reachable router from the list. * We just pick up the first reachable one (if any), assuming that * the ordering rule of the list described in defrtrlist_update(). */ ND_DEFROUTER_LIST_FOREACH(dr) { ndi = ND_IFINFO(dr->ifp); if (nd6_accepts_rtadv(ndi)) continue; if (selected_dr == NULL && nd6_is_llinfo_probreach(dr)) selected_dr = dr; if (dr->installed && !installed_dr) installed_dr = dr; else if (dr->installed && installed_dr) { /* this should not happen. warn for diagnosis. */ log(LOG_ERR, "nd6_defrouter_select: more than one router" " is installed\n"); } } /* * If none of the default routers was found to be reachable, * round-robin the list regardless of preference. * Otherwise, if we have an installed router, check if the selected * (reachable) router should really be preferred to the installed one. * We only prefer the new router when the old one is not reachable * or when the new one has a really higher preference value. */ if (selected_dr == NULL) { if (installed_dr == NULL || ND_DEFROUTER_LIST_NEXT(installed_dr) == NULL) selected_dr = ND_DEFROUTER_LIST_FIRST(); else selected_dr = ND_DEFROUTER_LIST_NEXT(installed_dr); } else if (installed_dr && nd6_is_llinfo_probreach(installed_dr) && rtpref(selected_dr) <= rtpref(installed_dr)) { selected_dr = installed_dr; } /* * If the selected router is different than the installed one, * remove the installed router and install the selected one. * Note that the selected router is never NULL here. */ if (installed_dr != selected_dr) { if (installed_dr) defrouter_delreq(installed_dr); defrouter_addreq(selected_dr); } return; } /* * for default router selection * regards router-preference field as a 2-bit signed integer */ static int rtpref(struct nd_defrouter *dr) { switch (dr->flags & ND_RA_FLAG_RTPREF_MASK) { case ND_RA_FLAG_RTPREF_HIGH: return (RTPREF_HIGH); case ND_RA_FLAG_RTPREF_MEDIUM: case ND_RA_FLAG_RTPREF_RSV: return (RTPREF_MEDIUM); case ND_RA_FLAG_RTPREF_LOW: return (RTPREF_LOW); default: /* * This case should never happen. If it did, it would mean a * serious bug of kernel internal. We thus always bark here. * Or, can we even panic? */ log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->flags); return (RTPREF_INVALID); } /* NOTREACHED */ } static struct nd_defrouter * defrtrlist_update(struct nd_defrouter *newdr) { struct nd_defrouter *dr, *n, *ret = NULL; struct in6_ifextra *ext = newdr->ifp->if_afdata[AF_INET6]; ND6_ASSERT_WLOCK(); if ((dr = nd6_defrouter_lookup(&newdr->rtaddr, newdr->ifp)) != NULL) { /* entry exists */ if (newdr->rtlifetime == 0) { nd6_defrtrlist_del(dr, ext); dr = NULL; } else { int oldpref = rtpref(dr); /* override */ dr->flags = newdr->flags; /* xxx flag check */ dr->rtlifetime = newdr->rtlifetime; dr->expire = newdr->expire; /* * If the preference does not change, there's no need * to sort the entries. */ if (rtpref(newdr) == oldpref) { ret = dr; goto out; } /* * preferred router may be changed, so relocate * this router. * XXX: calling TAILQ_REMOVE directly is a bad manner. * However, since nd6_defrtrlist_del() has many side * effects, we intentionally do so here. * nd6_defrouter_select() below will handle routing * changes later. */ ND_DEFROUTER_LIST_REMOVE(dr); n = dr; goto insert; } ret = dr; goto out; } if (ip6_maxifdefrouters >= 0 && ext->ndefrouters >= ip6_maxifdefrouters) goto out; /* entry does not exist */ if (newdr->rtlifetime == 0) goto out; if (ip6_rtadv_maxroutes <= nd6_numroutes) { ICMP6_STATINC(ICMP6_STAT_DROPPED_RAROUTE); goto out; } n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT); if (n == NULL) goto out; memset(n, 0, sizeof(*n)); *n = *newdr; insert: /* * Insert the new router in the Default Router List; * The Default Router List should be in the descending order * of router-preferece. Routers with the same preference are * sorted in the arriving time order. */ /* insert at the end of the group */ ND_DEFROUTER_LIST_FOREACH(dr) { if (rtpref(n) > rtpref(dr)) break; } if (dr) ND_DEFROUTER_LIST_INSERT_BEFORE(dr, n); else ND_DEFROUTER_LIST_INSERT_TAIL(n); nd6_defrouter_select(); ext->ndefrouters++; ret = n; out: return ret; } static struct nd_pfxrouter * pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr) { struct nd_pfxrouter *search; ND6_ASSERT_LOCK(); LIST_FOREACH(search, &pr->ndpr_advrtrs, pfr_entry) { if (search->router == dr) break; } return (search); } static void pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr) { struct nd_pfxrouter *newpfr; ND6_ASSERT_WLOCK(); newpfr = malloc(sizeof(*newpfr), M_IP6NDP, M_NOWAIT|M_ZERO); if (newpfr == NULL) return; newpfr->router = dr; LIST_INSERT_HEAD(&pr->ndpr_advrtrs, newpfr, pfr_entry); nd6_pfxlist_onlink_check(); } static void pfxrtr_del(struct nd_pfxrouter *pfr) { LIST_REMOVE(pfr, pfr_entry); free(pfr, M_IP6NDP); } static struct nd_prefix * nd6_prefix_lookup(struct nd_prefixctl *key) { struct nd_prefix *search; ND_PREFIX_LIST_FOREACH(search) { if (key->ndprc_ifp == search->ndpr_ifp && key->ndprc_plen == search->ndpr_plen && in6_are_prefix_equal(&key->ndprc_prefix.sin6_addr, &search->ndpr_prefix.sin6_addr, key->ndprc_plen)) { break; } } return (search); } static void purge_detached(struct ifnet *ifp) { struct nd_prefix *pr, *pr_next; struct in6_ifaddr *ia; struct ifaddr *ifa, *ifa_next; restart: ND6_ASSERT_WLOCK(); ND_PREFIX_LIST_FOREACH_SAFE(pr, pr_next) { int s; /* * This function is called when we need to make more room for * new prefixes rather than keeping old, possibly stale ones. * Detached prefixes would be a good candidate; if all routers * that advertised the prefix expired, the prefix is also * probably stale. */ if (pr->ndpr_ifp != ifp || IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) || ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 && !LIST_EMPTY(&pr->ndpr_advrtrs))) continue; s = pserialize_read_enter(); for (ifa = IFADDR_READER_FIRST(ifp); ifa; ifa = ifa_next) { ifa_next = IFADDR_READER_NEXT(ifa); if (ifa->ifa_addr->sa_family != AF_INET6) continue; ia = (struct in6_ifaddr *)ifa; if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == IN6_IFF_AUTOCONF && ia->ia6_ndpr == pr) { pserialize_read_exit(s); ND6_UNLOCK(); /* in6_purgeaddr may destroy pr. */ in6_purgeaddr(ifa); ND6_WLOCK(); goto restart; } } pserialize_read_exit(s); KASSERT(pr->ndpr_refcnt == 0); nd6_prelist_remove(pr); } } static int nd6_prelist_add(struct nd_prefixctl *prc, struct nd_defrouter *dr, struct nd_prefix **newp) { struct nd_prefix *newpr = NULL; int i; int error; struct in6_ifextra *ext = prc->ndprc_ifp->if_afdata[AF_INET6]; ND6_ASSERT_WLOCK(); if (ip6_maxifprefixes >= 0) { if (ext->nprefixes >= ip6_maxifprefixes / 2) purge_detached(prc->ndprc_ifp); if (ext->nprefixes >= ip6_maxifprefixes) return ENOMEM; } error = 0; newpr = malloc(sizeof(*newpr), M_IP6NDP, M_NOWAIT|M_ZERO); if (newpr == NULL) return ENOMEM; newpr->ndpr_ifp = prc->ndprc_ifp; newpr->ndpr_prefix = prc->ndprc_prefix; newpr->ndpr_plen = prc->ndprc_plen; newpr->ndpr_vltime = prc->ndprc_vltime; newpr->ndpr_pltime = prc->ndprc_pltime; newpr->ndpr_flags = prc->ndprc_flags; if ((error = in6_init_prefix_ltimes(newpr)) != 0) { free(newpr, M_IP6NDP); return(error); } newpr->ndpr_lastupdate = time_uptime; if (newp != NULL) *newp = newpr; /* initialization */ LIST_INIT(&newpr->ndpr_advrtrs); in6_prefixlen2mask(&newpr->ndpr_mask, newpr->ndpr_plen); /* make prefix in the canonical form */ for (i = 0; i < 4; i++) { newpr->ndpr_prefix.sin6_addr.s6_addr32[i] &= newpr->ndpr_mask.s6_addr32[i]; } /* link ndpr_entry to nd_prefix list */ ND_PREFIX_LIST_INSERT_HEAD(newpr); /* ND_OPT_PI_FLAG_ONLINK processing */ if (newpr->ndpr_raf_onlink) { int e; if ((e = nd6_prefix_onlink(newpr)) != 0) { char ip6buf[INET6_ADDRSTRLEN]; nd6log(LOG_ERR, "failed to make " "the prefix %s/%d on-link on %s (errno=%d)\n", IN6_PRINT(ip6buf, &prc->ndprc_prefix.sin6_addr), prc->ndprc_plen, if_name(prc->ndprc_ifp), e); /* proceed anyway. XXX: is it correct? */ } } if (dr) pfxrtr_add(newpr, dr); ext->nprefixes++; return 0; } void nd6_prefix_unref(struct nd_prefix *pr) { ND6_WLOCK(); pr->ndpr_refcnt--; if (pr->ndpr_refcnt == 0) nd6_prelist_remove(pr); ND6_UNLOCK(); } void nd6_invalidate_prefix(struct nd_prefix *pr) { int e; ND6_ASSERT_WLOCK(); /* make sure to invalidate the prefix until it is really freed. */ pr->ndpr_vltime = 0; pr->ndpr_pltime = 0; #if 0 /* * Though these flags are now meaningless, we'd rather keep the value * not to confuse users when executing "ndp -p". */ pr->ndpr_raf_onlink = 0; pr->ndpr_raf_auto = 0; #endif if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 && (e = nd6_prefix_offlink(pr)) != 0) { char ip6buf[INET6_ADDRSTRLEN]; nd6log(LOG_ERR, "failed to make %s/%d offlink on %s, errno=%d\n", IN6_PRINT(ip6buf, &pr->ndpr_prefix.sin6_addr), pr->ndpr_plen, if_name(pr->ndpr_ifp), e); /* what should we do? */ } } void nd6_prelist_remove(struct nd_prefix *pr) { struct nd_pfxrouter *pfr, *next; struct in6_ifextra *ext = pr->ndpr_ifp->if_afdata[AF_INET6]; ND6_ASSERT_WLOCK(); KASSERT(pr->ndpr_refcnt == 0); nd6_invalidate_prefix(pr); /* unlink ndpr_entry from nd_prefix list */ ND_PREFIX_LIST_REMOVE(pr); /* free list of routers that adversed the prefix */ for (pfr = LIST_FIRST(&pr->ndpr_advrtrs); pfr != NULL; pfr = next) { next = LIST_NEXT(pfr, pfr_entry); free(pfr, M_IP6NDP); } if (ext) { ext->nprefixes--; if (ext->nprefixes < 0) { log(LOG_WARNING, "nd6_prelist_remove: negative count on " "%s\n", pr->ndpr_ifp->if_xname); } } free(pr, M_IP6NDP); nd6_pfxlist_onlink_check(); } static int prelist_update(struct nd_prefixctl *newprc, struct nd_defrouter *dr, /* may be NULL */ struct mbuf *m, int mcast) { struct in6_ifaddr *ia6_match = NULL; struct ifaddr *ifa; struct ifnet *ifp = newprc->ndprc_ifp; struct nd_prefix *pr; int error = 0; int auth; struct in6_addrlifetime lt6_tmp; int ss; char ip6buf[INET6_ADDRSTRLEN]; ND6_ASSERT_WLOCK(); auth = 0; if (m) { auth = (m->m_flags & M_AUTHIPHDR) ? 1 : 0; } if ((pr = nd6_prefix_lookup(newprc)) != NULL) { /* * nd6_prefix_lookup() ensures that pr and newprc have the same * prefix on a same interface. */ /* * Update prefix information. Note that the on-link (L) bit * and the autonomous (A) bit should NOT be changed from 1 * to 0. */ if (newprc->ndprc_raf_onlink == 1) pr->ndpr_raf_onlink = 1; if (newprc->ndprc_raf_auto == 1) pr->ndpr_raf_auto = 1; if (newprc->ndprc_raf_onlink) { pr->ndpr_vltime = newprc->ndprc_vltime; pr->ndpr_pltime = newprc->ndprc_pltime; (void)in6_init_prefix_ltimes(pr); /* XXX error case? */ pr->ndpr_lastupdate = time_uptime; } if (newprc->ndprc_raf_onlink && (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) { int e; if ((e = nd6_prefix_onlink(pr)) != 0) { nd6log(LOG_ERR, "failed to make " "the prefix %s/%d on-link on %s " "(errno=%d)\n", IN6_PRINT(ip6buf, &pr->ndpr_prefix.sin6_addr), pr->ndpr_plen, if_name(pr->ndpr_ifp), e); /* proceed anyway. XXX: is it correct? */ } } if (dr && pfxrtr_lookup(pr, dr) == NULL) pfxrtr_add(pr, dr); } else { struct nd_prefix *newpr = NULL; if (newprc->ndprc_vltime == 0) goto end; if (newprc->ndprc_raf_onlink == 0 && newprc->ndprc_raf_auto == 0) goto end; if (ip6_rtadv_maxroutes <= nd6_numroutes) { ICMP6_STATINC(ICMP6_STAT_DROPPED_RAROUTE); goto end; } error = nd6_prelist_add(newprc, dr, &newpr); if (error != 0 || newpr == NULL) { nd6log(LOG_NOTICE, "nd6_prelist_add failed for %s/%d on %s " "errno=%d, returnpr=%p\n", IN6_PRINT(ip6buf, &newprc->ndprc_prefix.sin6_addr), newprc->ndprc_plen, if_name(newprc->ndprc_ifp), error, newpr); goto end; /* we should just give up in this case. */ } /* * XXX: from the ND point of view, we can ignore a prefix * with the on-link bit being zero. However, we need a * prefix structure for references from autoconfigured * addresses. Thus, we explicitly make sure that the prefix * itself expires now. */ if (newpr->ndpr_raf_onlink == 0) { newpr->ndpr_vltime = 0; newpr->ndpr_pltime = 0; in6_init_prefix_ltimes(newpr); } pr = newpr; } /* * Address autoconfiguration based on Section 5.5.3 of RFC 2462. * Note that pr must be non NULL at this point. */ /* 5.5.3 (a). Ignore the prefix without the A bit set. */ if (!newprc->ndprc_raf_auto) goto end; /* * 5.5.3 (b). the link-local prefix should have been ignored in * nd6_ra_input. */ /* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */ if (newprc->ndprc_pltime > newprc->ndprc_vltime) { error = EINVAL; /* XXX: won't be used */ goto end; } /* * 5.5.3 (d). If the prefix advertised is not equal to the prefix of * an address configured by stateless autoconfiguration already in the * list of addresses associated with the interface, and the Valid * Lifetime is not 0, form an address. We first check if we have * a matching prefix. * Note: we apply a clarification in rfc2462bis-02 here. We only * consider autoconfigured addresses while RFC2462 simply said * "address". */ ss = pserialize_read_enter(); IFADDR_READER_FOREACH(ifa, ifp) { struct in6_ifaddr *ia6; u_int32_t remaininglifetime; if (ifa->ifa_addr->sa_family != AF_INET6) continue; ia6 = (struct in6_ifaddr *)ifa; /* * We only consider autoconfigured addresses as per rfc2462bis. */ if (!(ia6->ia6_flags & IN6_IFF_AUTOCONF)) continue; /* * Spec is not clear here, but I believe we should concentrate * on unicast (i.e. not anycast) addresses. * XXX: other ia6_flags? detached or duplicated? */ if ((ia6->ia6_flags & IN6_IFF_ANYCAST) != 0) continue; /* * Ignore the address if it is not associated with a prefix * or is associated with a prefix that is different from this * one. (pr is never NULL here) */ if (ia6->ia6_ndpr != pr) continue; if (ia6_match == NULL) /* remember the first one */ ia6_match = ia6; /* * An already autoconfigured address matched. Now that we * are sure there is at least one matched address, we can * proceed to 5.5.3. (e): update the lifetimes according to the * "two hours" rule and the privacy extension. * We apply some clarifications in rfc2462bis: * - use remaininglifetime instead of storedlifetime as a * variable name * - remove the dead code in the "two-hour" rule */ #define TWOHOUR (120*60) lt6_tmp = ia6->ia6_lifetime; if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME) remaininglifetime = ND6_INFINITE_LIFETIME; else if (time_uptime - ia6->ia6_updatetime > lt6_tmp.ia6t_vltime) { /* * The case of "invalid" address. We should usually * not see this case. */ remaininglifetime = 0; } else remaininglifetime = lt6_tmp.ia6t_vltime - (time_uptime - ia6->ia6_updatetime); /* when not updating, keep the current stored lifetime. */ lt6_tmp.ia6t_vltime = remaininglifetime; if (TWOHOUR < newprc->ndprc_vltime || remaininglifetime < newprc->ndprc_vltime) { lt6_tmp.ia6t_vltime = newprc->ndprc_vltime; } else if (remaininglifetime <= TWOHOUR) { if (auth) lt6_tmp.ia6t_vltime = newprc->ndprc_vltime; } else { /* * newprc->ndprc_vltime <= TWOHOUR && * TWOHOUR < remaininglifetime */ lt6_tmp.ia6t_vltime = TWOHOUR; } /* The 2 hour rule is not imposed for preferred lifetime. */ lt6_tmp.ia6t_pltime = newprc->ndprc_pltime; in6_init_address_ltimes(pr, <6_tmp); /* * We need to treat lifetimes for temporary addresses * differently, according to * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1); * we only update the lifetimes when they are in the maximum * intervals. */ if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) { u_int32_t maxvltime, maxpltime; if (ip6_temp_valid_lifetime > (u_int32_t)((time_uptime - ia6->ia6_createtime) + ip6_desync_factor)) { maxvltime = ip6_temp_valid_lifetime - (time_uptime - ia6->ia6_createtime) - ip6_desync_factor; } else maxvltime = 0; if (ip6_temp_preferred_lifetime > (u_int32_t)((time_uptime - ia6->ia6_createtime) + ip6_desync_factor)) { maxpltime = ip6_temp_preferred_lifetime - (time_uptime - ia6->ia6_createtime) - ip6_desync_factor; } else maxpltime = 0; if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME || lt6_tmp.ia6t_vltime > maxvltime) { lt6_tmp.ia6t_vltime = maxvltime; } if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME || lt6_tmp.ia6t_pltime > maxpltime) { lt6_tmp.ia6t_pltime = maxpltime; } } ia6->ia6_lifetime = lt6_tmp; ia6->ia6_updatetime = time_uptime; } pserialize_read_exit(ss); if (ia6_match == NULL && newprc->ndprc_vltime) { int ifidlen; struct in6_ifaddr *ia6; struct psref psref; /* * 5.5.3 (d) (continued) * No address matched and the valid lifetime is non-zero. * Create a new address. */ /* * Prefix Length check: * If the sum of the prefix length and interface identifier * length does not equal 128 bits, the Prefix Information * option MUST be ignored. The length of the interface * identifier is defined in a separate link-type specific * document. */ ifidlen = in6_if2idlen(ifp); if (ifidlen < 0) { /* this should not happen, so we always log it. */ log(LOG_ERR, "%s: IFID undefined (%s)\n", __func__, if_name(ifp)); goto end; } if (ifidlen + pr->ndpr_plen != 128) { nd6log(LOG_INFO, "invalid prefixlen %d for %s, ignored\n", pr->ndpr_plen, if_name(ifp)); goto end; } if ((ia6 = in6_ifadd(newprc, mcast, &psref)) != NULL) { /* * note that we should use pr (not newprc) for reference. */ pr->ndpr_refcnt++; ia6->ia6_ndpr = pr; /* toggle onlink state if the address was assigned * a prefix route. */ if (ia6->ia_flags & IFA_ROUTE) pr->ndpr_stateflags |= NDPRF_ONLINK; /* * draft-ietf-ipngwg-temp-addresses-v2-00 3.3 (2). * When a new public address is created as described * in RFC2462, also create a new temporary address. * * draft-ietf-ipngwg-temp-addresses-v2-00 3.5. * When an interface connects to a new link, a new * randomized interface identifier should be generated * immediately together with a new set of temporary * addresses. Thus, we specifiy 1 as the 2nd arg of * in6_tmpifadd(). */ if (ip6_use_tempaddr) { int e; if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) { nd6log(LOG_NOTICE, "failed to create a temporary " "address, errno=%d\n", e); } } ia6_release(ia6, &psref); /* * A newly added address might affect the status * of other addresses, so we check and update it. * XXX: what if address duplication happens? */ nd6_pfxlist_onlink_check(); } else { /* just set an error. do not bark here. */ error = EADDRNOTAVAIL; /* XXX: might be unused. */ } } end: 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(struct nd_prefix *pr) { struct nd_pfxrouter *pfxrtr; for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr; pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) { if (pfxrtr->router->ifp->if_flags & IFF_UP && pfxrtr->router->ifp->if_link_state != LINK_STATE_DOWN && nd6_is_llinfo_probreach(pfxrtr->router)) 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 is 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 * 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 nd6_pfxlist_onlink_check(void) { struct nd_prefix *pr; struct in6_ifaddr *ia; struct nd_defrouter *dr; struct nd_pfxrouter *pfxrtr = NULL; int s; char ip6buf[INET6_ADDRSTRLEN]; ND6_ASSERT_WLOCK(); /* * Check if there is a prefix that has a reachable advertising * router. */ ND_PREFIX_LIST_FOREACH(pr) { if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr)) break; } /* * If we have no such prefix, check whether we still have a router * that does not advertise any prefixes. */ if (pr == NULL) { ND_DEFROUTER_LIST_FOREACH(dr) { struct nd_prefix *pr0; ND_PREFIX_LIST_FOREACH(pr0) { if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL) break; } if (pfxrtr) break; } } if (pr != NULL || (!ND_DEFROUTER_LIST_EMPTY() && !pfxrtr)) { /* * There is at least one prefix that has a reachable router, * or at least a router which probably does not advertise * any prefixes. The latter would be the case when we move * to a new link where we have a router that does not provide * prefixes and we configure an address by hand. * Detach prefixes which have no reachable advertising * router, and attach other prefixes. */ ND_PREFIX_LIST_FOREACH(pr) { /* XXX: a link-local prefix should never be detached */ if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) continue; /* * we aren't interested in prefixes without the L bit * set. */ if (pr->ndpr_raf_onlink == 0) continue; if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 && find_pfxlist_reachable_router(pr) == NULL) pr->ndpr_stateflags |= NDPRF_DETACHED; if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 && find_pfxlist_reachable_router(pr) != 0) pr->ndpr_stateflags &= ~NDPRF_DETACHED; } } else { /* there is no prefix that has a reachable router */ ND_PREFIX_LIST_FOREACH(pr) { if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) continue; if (pr->ndpr_raf_onlink == 0) continue; if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0) pr->ndpr_stateflags &= ~NDPRF_DETACHED; } } /* * Remove each interface route associated with a (just) detached * prefix, and reinstall the interface route for a (just) attached * prefix. Note that all attempt of reinstallation does not * necessarily success, when a same prefix is shared among multiple * interfaces. Such cases will be handled in nd6_prefix_onlink, * so we don't have to care about them. */ ND_PREFIX_LIST_FOREACH(pr) { int e; if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) continue; if (pr->ndpr_raf_onlink == 0) continue; if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 && (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) { if ((e = nd6_prefix_offlink(pr)) != 0) { nd6log(LOG_ERR, "failed to make %s/%d offlink, errno=%d\n", IN6_PRINT(ip6buf, &pr->ndpr_prefix.sin6_addr), pr->ndpr_plen, e); } } if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 && (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 && pr->ndpr_raf_onlink) { if ((e = nd6_prefix_onlink(pr)) != 0) { nd6log(LOG_ERR, "failed to make %s/%d onlink, errno=%d\n", IN6_PRINT(ip6buf, &pr->ndpr_prefix.sin6_addr), pr->ndpr_plen, e); } } } /* * Changes on the prefix status might affect address status as well. * Make sure that all addresses derived from an attached prefix are * attached, and that all addresses derived from a detached prefix are * detached. Note, however, that a manually configured address should * always be attached. * The precise detection logic is same as the one for prefixes. */ s = pserialize_read_enter(); IN6_ADDRLIST_READER_FOREACH(ia) { if (!(ia->ia6_flags & IN6_IFF_AUTOCONF)) continue; if (ia->ia6_ndpr == NULL) { /* * This can happen when we first configure the address * (i.e. the address exists, but the prefix does not). * XXX: complicated relationships... */ continue; } if (find_pfxlist_reachable_router(ia->ia6_ndpr)) break; } pserialize_read_exit(s); if (ia) { int bound = curlwp_bind(); s = pserialize_read_enter(); IN6_ADDRLIST_READER_FOREACH(ia) { struct ifaddr *ifa = (struct ifaddr *)ia; struct psref psref; if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0) continue; if (ia->ia6_ndpr == NULL) /* XXX: see above. */ continue; ia6_acquire(ia, &psref); pserialize_read_exit(s); if (find_pfxlist_reachable_router(ia->ia6_ndpr)) { if (ia->ia6_flags & IN6_IFF_DETACHED) { ia->ia6_flags &= ~IN6_IFF_DETACHED; ia->ia6_flags |= IN6_IFF_TENTATIVE; nd6_dad_start(ifa, 0); /* We will notify the routing socket * of the DAD result, so no need to * here */ } } else { if ((ia->ia6_flags & IN6_IFF_DETACHED) == 0) { ia->ia6_flags |= IN6_IFF_DETACHED; rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); } } s = pserialize_read_enter(); ia6_release(ia, &psref); } pserialize_read_exit(s); curlwp_bindx(bound); } else { int bound = curlwp_bind(); s = pserialize_read_enter(); IN6_ADDRLIST_READER_FOREACH(ia) { if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0) continue; if (ia->ia6_flags & IN6_IFF_DETACHED) { struct ifaddr *ifa = (struct ifaddr *)ia; struct psref psref; ia->ia6_flags &= ~IN6_IFF_DETACHED; ia->ia6_flags |= IN6_IFF_TENTATIVE; ia6_acquire(ia, &psref); pserialize_read_exit(s); /* Do we need a delay in this case? */ nd6_dad_start(ifa, 0); s = pserialize_read_enter(); ia6_release(ia, &psref); } } pserialize_read_exit(s); curlwp_bindx(bound); } } static int nd6_prefix_onlink(struct nd_prefix *pr) { struct ifaddr *ifa; struct ifnet *ifp = pr->ndpr_ifp; struct sockaddr_in6 mask6; struct nd_prefix *opr; u_long rtflags; int error = 0; struct psref psref; int bound; char ip6buf[INET6_ADDRSTRLEN]; char ip6bufp[INET6_ADDRSTRLEN], ip6bufm[INET6_ADDRSTRLEN]; ND6_ASSERT_WLOCK(); /* sanity check */ if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) { nd6log(LOG_ERR, "%s/%d is already on-link\n", IN6_PRINT(ip6buf, &pr->ndpr_prefix.sin6_addr), pr->ndpr_plen); return (EEXIST); } /* * Add the interface route associated with the prefix. Before * installing the route, check if there's the same prefix on another * interface, and the prefix has already installed the interface route. * Although such a configuration is expected to be rare, we explicitly * allow it. */ ND_PREFIX_LIST_FOREACH(opr) { if (opr == pr) continue; if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0) continue; if (opr->ndpr_plen == pr->ndpr_plen && in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr, &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) return (0); } /* * We prefer link-local addresses as the associated interface address. */ /* search for a link-local addr */ bound = curlwp_bind(); ifa = (struct ifaddr *)in6ifa_ifpforlinklocal_psref(ifp, IN6_IFF_NOTREADY | IN6_IFF_ANYCAST, &psref); if (ifa == NULL) { int s = pserialize_read_enter(); IFADDR_READER_FOREACH(ifa, ifp) { if (ifa->ifa_addr->sa_family == AF_INET6) break; } if (ifa != NULL) ifa_acquire(ifa, &psref); pserialize_read_exit(s); /* should we care about ia6_flags? */ } if (ifa == NULL) { /* * This can still happen, when, for example, we receive an RA * containing a prefix with the L bit set and the A bit clear, * after removing all IPv6 addresses on the receiving * interface. This should, of course, be rare though. */ nd6log(LOG_NOTICE, "failed to find any ifaddr" " to add route for a prefix(%s/%d) on %s\n", IN6_PRINT(ip6buf, &pr->ndpr_prefix.sin6_addr), pr->ndpr_plen, if_name(ifp)); curlwp_bindx(bound); return (0); } /* * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs. * ifa->ifa_rtrequest = nd6_rtrequest; */ memset(&mask6, 0, sizeof(mask6)); mask6.sin6_family = AF_INET6; mask6.sin6_len = sizeof(mask6); mask6.sin6_addr = pr->ndpr_mask; /* rtrequest() will probably set RTF_UP, but we're not sure. */ rtflags = ifa->ifa_flags | RTF_UP; if (nd6_need_cache(ifp)) { /* explicitly set in case ifa_flags does not set the flag. */ rtflags |= RTF_CONNECTED; } else { /* * explicitly clear the cloning bit in case ifa_flags sets it. */ rtflags &= ~RTF_CONNECTED; } error = rtrequest_newmsg(RTM_ADD, sin6tosa(&pr->ndpr_prefix), ifa->ifa_addr, sin6tosa(&mask6), rtflags); if (error == 0) { nd6_numroutes++; pr->ndpr_stateflags |= NDPRF_ONLINK; } else { nd6log(LOG_ERR, "failed to add route for a" " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx " "errno = %d\n", IN6_PRINT(ip6bufp, &pr->ndpr_prefix.sin6_addr), pr->ndpr_plen, if_name(ifp), IN6_PRINT(ip6buf, &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr), IN6_PRINT(ip6bufm, &mask6.sin6_addr), rtflags, error); } ifa_release(ifa, &psref); curlwp_bindx(bound); return (error); } static int nd6_prefix_offlink(struct nd_prefix *pr) { int error = 0; struct ifnet *ifp = pr->ndpr_ifp; struct nd_prefix *opr; struct sockaddr_in6 sa6, mask6; char ip6buf[INET6_ADDRSTRLEN]; ND6_ASSERT_WLOCK(); /* sanity check */ if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) { nd6log(LOG_ERR, "%s/%d is already off-link\n", IN6_PRINT(ip6buf, &pr->ndpr_prefix.sin6_addr), pr->ndpr_plen); return (EEXIST); } sockaddr_in6_init(&sa6, &pr->ndpr_prefix.sin6_addr, 0, 0, 0); sockaddr_in6_init(&mask6, &pr->ndpr_mask, 0, 0, 0); error = rtrequest_newmsg(RTM_DELETE, sin6tosa(&sa6), NULL, sin6tosa(&mask6), 0); if (error == 0) { pr->ndpr_stateflags &= ~NDPRF_ONLINK; nd6_numroutes--; /* * There might be the same prefix on another interface, * the prefix which could not be on-link just because we have * the interface route (see comments in nd6_prefix_onlink). * If there's one, try to make the prefix on-link on the * interface. */ ND_PREFIX_LIST_FOREACH(opr) { if (opr == pr) continue; if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0) continue; /* * KAME specific: detached prefixes should not be * on-link. */ if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0) continue; if (opr->ndpr_plen == pr->ndpr_plen && in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr, &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) { int e; if ((e = nd6_prefix_onlink(opr)) != 0) { nd6log(LOG_ERR, "failed to " "recover a prefix %s/%d from %s " "to %s (errno = %d)\n", IN6_PRINT(ip6buf, &opr->ndpr_prefix.sin6_addr), opr->ndpr_plen, if_name(ifp), if_name(opr->ndpr_ifp), e); } } } } else { /* XXX: can we still set the NDPRF_ONLINK flag? */ nd6log(LOG_ERR, "failed to delete route: " "%s/%d on %s (errno = %d)\n", IN6_PRINT(ip6buf, &sa6.sin6_addr), pr->ndpr_plen, if_name(ifp), error); } return error; } static struct in6_ifaddr * in6_ifadd(struct nd_prefixctl *prc, int mcast, struct psref *psref) { struct ifnet *ifp = prc->ndprc_ifp; struct ifaddr *ifa; struct in6_aliasreq ifra; struct in6_ifaddr *ia, *ib; int error, plen0; struct in6_addr mask; int prefixlen = prc->ndprc_plen; int updateflags; int s; char ip6buf[INET6_ADDRSTRLEN]; ND6_ASSERT_WLOCK(); in6_prefixlen2mask(&mask, prefixlen); /* * find a link-local address (will be interface ID). * Is it really mandatory? Theoretically, a global or a site-local * address can be configured without a link-local address, if we * have a unique interface identifier... * * it is not mandatory to have a link-local address, we can generate * interface identifier on the fly. we do this because: * (1) it should be the easiest way to find interface identifier. * (2) RFC2462 5.4 suggesting the use of the same interface identifier * for multiple addresses on a single interface, and possible shortcut * of DAD. we omitted DAD for this reason in the past. * (3) a user can prevent autoconfiguration of global address * by removing link-local address by hand (this is partly because we * don't have other way to control the use of IPv6 on an interface. * this has been our design choice - cf. NRL's "ifconfig auto"). * (4) it is easier to manage when an interface has addresses * with the same interface identifier, than to have multiple addresses * with different interface identifiers. */ s = pserialize_read_enter(); ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */ if (ifa) ib = (struct in6_ifaddr *)ifa; else { pserialize_read_exit(s); 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 */ plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL); if (prefixlen != plen0) { nd6log(LOG_INFO, "wrong prefixlen for %s " "(prefix=%d ifid=%d)\n", if_name(ifp), prefixlen, 128 - plen0); pserialize_read_exit(s); return NULL; } /* make ifaddr */ memset(&ifra, 0, sizeof(ifra)); /* * in6_update_ifa() does not use ifra_name, but we accurately set it * for safety. */ strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name)); sockaddr_in6_init(&ifra.ifra_addr, &prc->ndprc_prefix.sin6_addr, 0, 0, 0); /* prefix */ ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0]; ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1]; ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2]; ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3]; /* interface ID */ ifra.ifra_addr.sin6_addr.s6_addr32[0] |= (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]); ifra.ifra_addr.sin6_addr.s6_addr32[1] |= (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]); ifra.ifra_addr.sin6_addr.s6_addr32[2] |= (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]); ifra.ifra_addr.sin6_addr.s6_addr32[3] |= (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]); pserialize_read_exit(s); /* new prefix mask. */ sockaddr_in6_init(&ifra.ifra_prefixmask, &mask, 0, 0, 0); /* lifetimes */ ifra.ifra_lifetime.ia6t_vltime = prc->ndprc_vltime; ifra.ifra_lifetime.ia6t_pltime = prc->ndprc_pltime; /* XXX: scope zone ID? */ ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */ /* * Make sure that we do not have this address already. This should * usually not happen, but we can still see this case, e.g., if we * have manually configured the exact address to be configured. */ s = pserialize_read_enter(); if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) { /* this should be rare enough to make an explicit log */ log(LOG_INFO, "in6_ifadd: %s is already configured\n", IN6_PRINT(ip6buf, &ifra.ifra_addr.sin6_addr)); pserialize_read_exit(s); return (NULL); } pserialize_read_exit(s); /* * Allocate ifaddr structure, link into chain, etc. * If we are going to create a new address upon receiving a multicasted * RA, we need to impose a random delay before starting DAD. * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2] */ updateflags = 0; if (mcast) updateflags |= IN6_IFAUPDATE_DADDELAY; if ((error = in6_update_ifa(ifp, &ifra, updateflags)) != 0) { nd6log(LOG_ERR, "failed to make ifaddr %s on %s (errno=%d)\n", IN6_PRINT(ip6buf, &ifra.ifra_addr.sin6_addr), if_name(ifp), error); return (NULL); /* ifaddr must not have been allocated. */ } ia = in6ifa_ifpwithaddr_psref(ifp, &ifra.ifra_addr.sin6_addr, psref); return (ia); /* this is always non-NULL */ } int in6_tmpifadd( const struct in6_ifaddr *ia0, /* corresponding public address */ int forcegen, int dad_delay) { struct ifnet *ifp = ia0->ia_ifa.ifa_ifp; struct in6_ifaddr *newia, *ia; struct in6_aliasreq ifra; int i, error; int trylimit = 3; /* XXX: adhoc value */ int updateflags; u_int32_t randid[2]; u_int32_t vltime0, pltime0; int s; ND6_ASSERT_WLOCK(); memset(&ifra, 0, sizeof(ifra)); strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name)); ifra.ifra_addr = ia0->ia_addr; /* copy prefix mask */ ifra.ifra_prefixmask = ia0->ia_prefixmask; /* clear the old IFID */ for (i = 0; i < 4; i++) { ifra.ifra_addr.sin6_addr.s6_addr32[i] &= ifra.ifra_prefixmask.sin6_addr.s6_addr32[i]; } again: if (in6_get_tmpifid(ifp, (u_int8_t *)randid, (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) { nd6log(LOG_NOTICE, "failed to find a good random IFID\n"); return (EINVAL); } ifra.ifra_addr.sin6_addr.s6_addr32[2] |= (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2])); ifra.ifra_addr.sin6_addr.s6_addr32[3] |= (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3])); /* * in6_get_tmpifid() quite likely provided a unique interface ID. * However, we may still have a chance to see collision, because * there may be a time lag between generation of the ID and generation * of the address. So, we'll do one more sanity check. */ s = pserialize_read_enter(); IN6_ADDRLIST_READER_FOREACH(ia) { if (IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &ifra.ifra_addr.sin6_addr)) { pserialize_read_exit(s); if (trylimit-- == 0) { /* * Give up. Something strange should have * happened. */ nd6log(LOG_NOTICE, "failed to find a unique random IFID\n"); return (EEXIST); } forcegen = 1; goto again; } } pserialize_read_exit(s); /* * The Valid Lifetime is the lower of the Valid Lifetime of the * public address or TEMP_VALID_LIFETIME. * The Preferred Lifetime is the lower of the Preferred Lifetime * of the public address or TEMP_PREFERRED_LIFETIME - * DESYNC_FACTOR. */ if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) { vltime0 = IFA6_IS_INVALID(ia0) ? 0 : (ia0->ia6_lifetime.ia6t_vltime - (time_uptime - ia0->ia6_updatetime)); if (vltime0 > ip6_temp_valid_lifetime) vltime0 = ip6_temp_valid_lifetime; } else vltime0 = ip6_temp_valid_lifetime; if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) { pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 : (ia0->ia6_lifetime.ia6t_pltime - (time_uptime - ia0->ia6_updatetime)); if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor){ pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor; } } else pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor; ifra.ifra_lifetime.ia6t_vltime = vltime0; ifra.ifra_lifetime.ia6t_pltime = pltime0; /* * A temporary address is created only if this calculated Preferred * Lifetime is greater than REGEN_ADVANCE time units. */ if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance) return (0); /* XXX: scope zone ID? */ ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY); /* allocate ifaddr structure, link into chain, etc. */ updateflags = 0; if (dad_delay) updateflags |= IN6_IFAUPDATE_DADDELAY; if ((error = in6_update_ifa(ifp, &ifra, updateflags)) != 0) return (error); s = pserialize_read_enter(); newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr); if (newia == NULL) { /* XXX: can it happen? */ pserialize_read_exit(s); nd6log(LOG_ERR, "ifa update succeeded, but we got no ifaddr\n"); return (EINVAL); /* XXX */ } newia->ia6_ndpr = ia0->ia6_ndpr; newia->ia6_ndpr->ndpr_refcnt++; pserialize_read_exit(s); /* * A newly added address might affect the status of other addresses. * XXX: when the temporary address is generated with a new public * address, the onlink check is redundant. However, it would be safe * to do the check explicitly everywhere a new address is generated, * and, in fact, we surely need the check when we create a new * temporary address due to deprecation of an old temporary address. */ nd6_pfxlist_onlink_check(); return (0); } static int in6_init_prefix_ltimes(struct nd_prefix *ndpr) { ND6_ASSERT_WLOCK(); /* check if preferred lifetime > valid lifetime. RFC2462 5.5.3 (c) */ if (ndpr->ndpr_pltime > ndpr->ndpr_vltime) { nd6log(LOG_INFO, "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_uptime + ndpr->ndpr_pltime; if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME) ndpr->ndpr_expire = 0; else ndpr->ndpr_expire = time_uptime + ndpr->ndpr_vltime; return 0; } static void in6_init_address_ltimes(struct nd_prefix *newpr, struct in6_addrlifetime *lt6) { /* Valid lifetime must not be updated unless explicitly specified. */ /* init ia6t_expire */ if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME) lt6->ia6t_expire = 0; else { lt6->ia6t_expire = time_uptime; lt6->ia6t_expire += lt6->ia6t_vltime; } /* init ia6t_preferred */ if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME) lt6->ia6t_preferred = 0; else { lt6->ia6t_preferred = time_uptime; lt6->ia6t_preferred += lt6->ia6t_pltime; } } /* * 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 nd6_rt_flush(struct in6_addr *gateway, struct ifnet *ifp) { #ifndef NET_MPSAFE int s = splsoftnet(); #endif /* We'll care only link-local addresses */ if (!IN6_IS_ADDR_LINKLOCAL(gateway)) goto out; rt_delete_matched_entries(AF_INET6, rt6_deleteroute_matcher, gateway); out: #ifndef NET_MPSAFE splx(s); #endif return; /* XXX gcc */ } static int rt6_deleteroute_matcher(struct rtentry *rt, void *arg) { 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, &satosin6(rt->rt_gateway)->sin6_addr)) return (0); /* * Do not delete a static route. * XXX: this seems to be a bit ad-hoc. Should we consider the * 'cloned' bit instead? */ if ((rt->rt_flags & RTF_STATIC) != 0) 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 1; }