/* $OpenBSD: nd6_rtr.c,v 1.154 2016/12/22 13:39:32 mpi Exp $ */ /* $KAME: nd6_rtr.c,v 1.97 2001/02/07 11:09:13 itojun Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include int rtpref(struct nd_defrouter *); struct nd_defrouter *defrtrlist_update(struct nd_defrouter *); struct in6_ifaddr *in6_ifadd(struct nd_prefix *, int); struct nd_pfxrouter *pfxrtr_lookup(struct nd_prefix *, struct nd_defrouter *); void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *); void pfxrtr_del(struct nd_pfxrouter *); struct nd_pfxrouter *find_pfxlist_reachable_router(struct nd_prefix *); void defrouter_delreq(struct nd_defrouter *); void purge_detached(struct ifnet *); int nd6_prefix_onlink(struct nd_prefix *); int nd6_prefix_offlink(struct nd_prefix *); void in6_init_address_ltimes(struct nd_prefix *, struct in6_addrlifetime *); int prelist_update(struct nd_prefix *, struct nd_defrouter *, struct mbuf *); int nd6_prelist_add(struct nd_prefix *, struct nd_defrouter *, struct nd_prefix **); void defrouter_addreq(struct nd_defrouter *); int rt6_deleteroute(struct rtentry *, void *, unsigned int); void nd6_addr_add(void *); void nd6_rs_output_timo(void *); void nd6_rs_output_set_timo(int); void nd6_rs_output(struct ifnet *, struct in6_ifaddr *); void nd6_rs_dev_state(void *); extern int nd6_recalc_reachtm_interval; #define ND6_RS_OUTPUT_INTERVAL 60 #define ND6_RS_OUTPUT_QUICK_INTERVAL 1 struct timeout nd6_rs_output_timer; int nd6_rs_output_timeout = ND6_RS_OUTPUT_INTERVAL; int nd6_rs_timeout_count = 0; void nd6_rs_init(void) { timeout_set_proc(&nd6_rs_output_timer, nd6_rs_output_timo, NULL); } /* * 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(struct mbuf *m, int off, int icmp6len) { struct ifnet *ifp; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_router_solicit *nd_rs; 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 = NULL; struct llinfo_nd6 *ln = NULL; struct rtentry *rt = NULL; int is_newentry; #endif union nd_opts ndopts; char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; /* If I'm not a router, ignore it. XXX - too restrictive? */ if (!ip6_forwarding) goto freeit; /* Sanity checks */ if (ip6->ip6_hlim != 255) { nd6log((LOG_ERR, "nd6_rs_input: invalid hlim (%d) from %s to %s on %u\n", ip6->ip6_hlim, inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)), inet_ntop(AF_INET6, &ip6->ip6_dst, dst, sizeof(dst)), m->m_pkthdr.ph_ifidx)); 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) { icmp6stat.icp6s_tooshort++; return; } icmp6len -= sizeof(*nd_rs); nd6_option_init(nd_rs + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { nd6log((LOG_INFO, "nd6_rs_input: 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; } ifp = if_get(m->m_pkthdr.ph_ifidx); if (ifp == NULL) goto freeit; if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { nd6log((LOG_INFO, "nd6_rs_input: lladdrlen mismatch for %s " "(if %d, RS packet %d)\n", inet_ntop(AF_INET6, &saddr6, src, sizeof(src)), ifp->if_addrlen, lladdrlen - 2)); if_put(ifp); goto bad; } nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0); if_put(ifp); freeit: m_freem(m); return; bad: icmp6stat.icp6s_badrs++; m_freem(m); } void nd6_rs_output(struct ifnet* ifp, struct in6_ifaddr *ia6) { struct mbuf *m; struct ip6_hdr *ip6; struct nd_router_solicit *rs; struct ip6_moptions im6o; caddr_t mac; int icmp6len, maxlen; splsoftassert(IPL_SOFTNET); KASSERT(ia6 != NULL); KASSERT(ifp->if_flags & IFF_RUNNING); KASSERT(ifp->if_xflags & IFXF_AUTOCONF6); KASSERT(!(ia6->ia6_flags & IN6_IFF_TENTATIVE)); maxlen = sizeof(*ip6) + sizeof(*rs); maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; MGETHDR(m, M_DONTWAIT, MT_DATA); if (m && max_linkhdr + maxlen >= MHLEN) { MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { m_free(m); m = NULL; } } if (m == NULL) return; m->m_pkthdr.ph_ifidx = 0; m->m_pkthdr.ph_rtableid = ifp->if_rdomain; m->m_flags |= M_MCAST; m->m_pkthdr.csum_flags |= M_ICMP_CSUM_OUT; im6o.im6o_ifidx = ifp->if_index; im6o.im6o_hlim = 255; im6o.im6o_loop = 0; icmp6len = sizeof(*rs); m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ /* fill neighbor solicitation packet */ ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_flow = 0; ip6->ip6_vfc &= ~IPV6_VERSION_MASK; ip6->ip6_vfc |= IPV6_VERSION; /* ip6->ip6_plen will be set later */ ip6->ip6_nxt = IPPROTO_ICMPV6; ip6->ip6_hlim = 255; ip6->ip6_dst = in6addr_linklocal_allrouters; ip6->ip6_src = ia6->ia_addr.sin6_addr; rs = (struct nd_router_solicit *)(ip6 + 1); rs->nd_rs_type = ND_ROUTER_SOLICIT; rs->nd_rs_code = 0; rs->nd_rs_cksum = 0; rs->nd_rs_reserved = 0; if ((mac = nd6_ifptomac(ifp))) { int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(rs + 1); /* 8 byte alignments... */ optlen = (optlen + 7) & ~7; m->m_pkthdr.len += optlen; m->m_len += optlen; icmp6len += optlen; bzero((caddr_t)nd_opt, optlen); nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; nd_opt->nd_opt_len = optlen >> 3; bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); } ip6->ip6_plen = htons((u_short)icmp6len); ip6_output(m, NULL, NULL, 0, &im6o, NULL); icmp6stat.icp6s_outhist[ND_ROUTER_SOLICIT]++; } void nd6_rs_output_set_timo(int timeout) { nd6_rs_output_timeout = timeout; timeout_add_sec(&nd6_rs_output_timer, nd6_rs_output_timeout); } void nd6_rs_output_timo(void *ignored_arg) { struct ifnet *ifp; struct in6_ifaddr *ia6; int s; if (nd6_rs_timeout_count == 0) return; if (nd6_rs_output_timeout < ND6_RS_OUTPUT_INTERVAL) /* exponential backoff if running quick timeouts */ nd6_rs_output_timeout *= 2; if (nd6_rs_output_timeout > ND6_RS_OUTPUT_INTERVAL) nd6_rs_output_timeout = ND6_RS_OUTPUT_INTERVAL; NET_LOCK(s); TAILQ_FOREACH(ifp, &ifnet, if_list) { if (ISSET(ifp->if_flags, IFF_RUNNING) && ISSET(ifp->if_xflags, IFXF_AUTOCONF6)) { ia6 = in6ifa_ifpforlinklocal(ifp, IN6_IFF_TENTATIVE); if (ia6 != NULL) nd6_rs_output(ifp, ia6); } } NET_UNLOCK(s); nd6_rs_output_set_timo(nd6_rs_output_timeout); } void nd6_rs_attach(struct ifnet *ifp) { if (!ISSET(ifp->if_xflags, IFXF_AUTOCONF6)) { /* * We are being called from net/if.c, autoconf is not yet * enabled on the interface. */ nd6_rs_timeout_count++; RS_LHCOOKIE(ifp) = hook_establish(ifp->if_linkstatehooks, 1, nd6_rs_dev_state, ifp); } /* * (re)send solicitation regardless if we are enabling autoconf * for the first time or if the link comes up */ nd6_rs_output_set_timo(ND6_RS_OUTPUT_QUICK_INTERVAL); } void nd6_rs_detach(struct ifnet *ifp) { if (ISSET(ifp->if_xflags, IFXF_AUTOCONF6)) { nd6_rs_timeout_count--; hook_disestablish(ifp->if_linkstatehooks, RS_LHCOOKIE(ifp)); } if (nd6_rs_timeout_count == 0) timeout_del(&nd6_rs_output_timer); } void nd6_rs_dev_state(void *arg) { struct ifnet *ifp; ifp = (struct ifnet *) arg; if (LINK_STATE_IS_UP(ifp->if_link_state) && ifp->if_flags & IFF_RUNNING) /* start quick timer, will exponentially back off */ nd6_rs_output_set_timo(ND6_RS_OUTPUT_QUICK_INTERVAL); } /* * Receive Router Advertisement Message. * * Based on RFC 2461 */ 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; union nd_opts ndopts; struct nd_defrouter *dr; char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; ifp = if_get(m->m_pkthdr.ph_ifidx); if (ifp == NULL) goto freeit; /* We accept RAs only if inet6 autoconf is enabled */ if (!(ifp->if_xflags & IFXF_AUTOCONF6)) goto freeit; ndi = ND_IFINFO(ifp); if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV)) goto freeit; if (nd6_rs_output_timeout != ND6_RS_OUTPUT_INTERVAL) /* we saw a RA, stop quick timer */ nd6_rs_output_set_timo(ND6_RS_OUTPUT_INTERVAL); if (ip6->ip6_hlim != 255) { nd6log((LOG_ERR, "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n", ip6->ip6_hlim, inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)), inet_ntop(AF_INET6, &ip6->ip6_dst, dst, sizeof(dst)), ifp->if_xname)); goto bad; } if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) { nd6log((LOG_ERR, "nd6_ra_input: src %s is not link-local\n", inet_ntop(AF_INET6, &saddr6, src, sizeof(src)))); goto bad; } IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len); if (nd_ra == NULL) { icmp6stat.icp6s_tooshort++; if_put(ifp); return; } icmp6len -= sizeof(*nd_ra); nd6_option_init(nd_ra + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { nd6log((LOG_INFO, "nd6_ra_input: invalid ND option, ignored\n")); /* nd6_options have incremented stats */ goto freeit; } { struct nd_defrouter dr0; u_int32_t advreachable = nd_ra->nd_ra_reachable; memset(&dr0, 0, sizeof(dr0)); dr0.rtaddr = saddr6; dr0.flags = nd_ra->nd_ra_flags_reserved; dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime); dr0.expire = time_uptime + dr0.rtlifetime; dr0.ifp = ifp; /* unspecified or not? (RFC 2461 6.3.4) */ if (advreachable) { 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) { /* * Ignore it. The router doesn't know the diameter of * the Internet better than this source code. */ } dr = defrtrlist_update(&dr0); } /* * prefix */ if (ndopts.nd_opts_pi) { struct nd_opt_hdr *pt; struct nd_opt_prefix_info *pi = NULL; 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) { nd6log((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) { nd6log((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)) { nd6log((LOG_INFO, "nd6_ra_input: invalid prefix " "%s, ignored\n", inet_ntop(AF_INET6, &pi->nd_opt_pi_prefix, src, sizeof(src)))); continue; } /* aggregatable unicast address, rfc2374 */ if ((pi->nd_opt_pi_prefix.s6_addr8[0] & 0xe0) == 0x20 && pi->nd_opt_pi_prefix_len != 64) { nd6log((LOG_INFO, "nd6_ra_input: invalid prefixlen " "%d for rfc2374 prefix %s, ignored\n", pi->nd_opt_pi_prefix_len, inet_ntop(AF_INET6, &pi->nd_opt_pi_prefix, src, sizeof(src)))); 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 = ifp; 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); pr.ndpr_lastupdate = time_uptime; if (in6_init_prefix_ltimes(&pr)) continue; /* prefix lifetime init failed */ (void)prelist_update(&pr, dr, m); } } /* * 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, "nd6_ra_input: lladdrlen mismatch for %s " "(if %d, RA packet %d)\n", inet_ntop(AF_INET6, &saddr6, src, sizeof(src)), 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 advertised prefixes. */ pfxlist_onlink_check(); } freeit: if_put(ifp); m_freem(m); return; bad: icmp6stat.icp6s_badra++; if_put(ifp); m_freem(m); } /* * default router list processing sub routines */ void defrouter_addreq(struct nd_defrouter *new) { struct rt_addrinfo info; struct sockaddr_in6 def, mask, gate; struct rtentry *rt; int error; memset(&def, 0, sizeof(def)); memset(&mask, 0, sizeof(mask)); memset(&gate, 0, sizeof(gate)); /* for safety */ memset(&info, 0, sizeof(info)); 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; gate.sin6_scope_id = 0; /* XXX */ info.rti_ifa = NULL; info.rti_flags = RTF_GATEWAY; info.rti_info[RTAX_DST] = sin6tosa(&def); info.rti_info[RTAX_GATEWAY] = sin6tosa(&gate); info.rti_info[RTAX_NETMASK] = sin6tosa(&mask); error = rtrequest(RTM_ADD, &info, RTP_DEFAULT, &rt, new->ifp->if_rdomain); if (error == 0) { rt_sendmsg(rt, RTM_ADD, new->ifp->if_rdomain); rtfree(rt); new->installed = 1; } } struct nd_defrouter * defrouter_lookup(struct in6_addr *addr, unsigned int ifidx) { struct nd_defrouter *dr; TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) if (dr->ifp->if_index == ifidx && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) return (dr); return (NULL); /* search failed */ } void defrtrlist_del(struct nd_defrouter *dr) { struct nd_defrouter *deldr = NULL; struct in6_ifextra *ext = dr->ifp->if_afdata[AF_INET6]; struct nd_prefix *pr; /* * Flush all the routing table entries that use the router * as a next hop. */ /* XXX: better condition? */ if (!ip6_forwarding) rt6_flush(&dr->rtaddr, dr->ifp); if (dr->installed) { deldr = dr; defrouter_delreq(dr); } TAILQ_REMOVE(&nd_defrouter, dr, dr_entry); /* * Also delete all the pointers to the router in each prefix lists. */ LIST_FOREACH(pr, &nd_prefix, ndpr_entry) { 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(); ext->ndefrouters--; if (ext->ndefrouters < 0) { log(LOG_WARNING, "%s: negative count on %s\n", __func__, dr->ifp->if_xname); } free(dr, M_IP6NDP, sizeof(*dr)); } /* * Remove the default route for a given router. * This is just a subroutine function for defrouter_select(), and should * not be called from anywhere else. */ void defrouter_delreq(struct nd_defrouter *dr) { struct rt_addrinfo info; struct sockaddr_in6 def, mask, gw; struct rtentry *rt; int error; #ifdef DIAGNOSTIC if (!dr) panic("dr == NULL in defrouter_delreq"); #endif memset(&info, 0, sizeof(info)); memset(&def, 0, sizeof(def)); memset(&mask, 0, sizeof(mask)); memset(&gw, 0, sizeof(gw)); /* for safety */ def.sin6_len = mask.sin6_len = gw.sin6_len = sizeof(struct sockaddr_in6); def.sin6_family = mask.sin6_family = gw.sin6_family = AF_INET6; gw.sin6_addr = dr->rtaddr; gw.sin6_scope_id = 0; /* XXX */ info.rti_flags = RTF_GATEWAY; info.rti_info[RTAX_DST] = sin6tosa(&def); info.rti_info[RTAX_GATEWAY] = sin6tosa(&gw); info.rti_info[RTAX_NETMASK] = sin6tosa(&mask); error = rtrequest(RTM_DELETE, &info, RTP_DEFAULT, &rt, dr->ifp->if_rdomain); if (error == 0) { rt_sendmsg(rt, RTM_DELETE, dr->ifp->if_rdomain); rtfree(rt); } dr->installed = 0; } /* * remove all default routes from default router list */ void defrouter_reset(void) { struct nd_defrouter *dr; TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) defrouter_delreq(dr); /* * XXX should we also nuke any default routers in the kernel, by * going through them by rtalloc()? */ } /* * 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 defrouter_select(void) { struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL; struct rtentry *rt = NULL; struct llinfo_nd6 *ln = NULL; /* * Let's handle easy case (3) first: * If default router list is empty, there's nothing to be done. */ if (TAILQ_EMPTY(&nd_defrouter)) { 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(). */ TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) { if (!(dr->ifp->if_xflags & IFXF_AUTOCONF6)) continue; if (!selected_dr) { rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp, dr->ifp->if_rdomain); if ((rt != NULL) && (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && ND6_IS_LLINFO_PROBREACH(ln)) { selected_dr = dr; } rtfree(rt); } if (dr->installed && !installed_dr) installed_dr = dr; else if (dr->installed && installed_dr) { /* this should not happen. warn for diagnosis. */ log(LOG_ERR, "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) { if (!installed_dr || !TAILQ_NEXT(installed_dr, dr_entry)) selected_dr = TAILQ_FIRST(&nd_defrouter); else selected_dr = TAILQ_NEXT(installed_dr, dr_entry); } else if (installed_dr) { rt = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp, installed_dr->ifp->if_rdomain); if ((rt != NULL) && (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && ND6_IS_LLINFO_PROBREACH(ln) && rtpref(selected_dr) <= rtpref(installed_dr)) { selected_dr = installed_dr; } rtfree(rt); } /* * 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); } } /* * for default router selection * regards router-preference field as a 2-bit signed integer */ int rtpref(struct nd_defrouter *dr) { #ifdef RTPREF 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", dr->flags); return RTPREF_INVALID; } /* NOTREACHED */ #else return 0; #endif } struct nd_defrouter * defrtrlist_update(struct nd_defrouter *new) { struct nd_defrouter *dr, *n; struct in6_ifextra *ext = new->ifp->if_afdata[AF_INET6]; splsoftassert(IPL_SOFTNET); if ((dr = defrouter_lookup(&new->rtaddr, new->ifp->if_index)) != NULL) { /* entry exists */ if (new->rtlifetime == 0) { defrtrlist_del(dr); dr = NULL; } else { int oldpref = rtpref(dr); /* override */ dr->flags = new->flags; /* xxx flag check */ dr->rtlifetime = new->rtlifetime; dr->expire = new->expire; if (!dr->installed) defrouter_select(); /* * If the preference does not change, there's no need * to sort the entries. */ if (rtpref(new) == oldpref) { return (dr); } /* * preferred router may be changed, so relocate * this router. * XXX: calling TAILQ_REMOVE directly is a bad manner. * However, since defrtrlist_del() has many side * effects, we intentionally do so here. * defrouter_select() below will handle routing * changes later. */ TAILQ_REMOVE(&nd_defrouter, dr, dr_entry); n = dr; goto insert; } return (dr); } /* entry does not exist */ if (new->rtlifetime == 0) { /* flush all possible redirects */ if (new->ifp->if_xflags & IFXF_AUTOCONF6) rt6_flush(&new->rtaddr, new->ifp); return (NULL); } if (ip6_maxifdefrouters >= 0 && ext->ndefrouters >= ip6_maxifdefrouters) { return (NULL); } n = malloc(sizeof(*n), M_IP6NDP, M_NOWAIT | M_ZERO); if (n == NULL) { return (NULL); } *n = *new; insert: /* * Insert the new router in the Default Router List; * The Default Router List should be in the descending order * of router-preference. Routers with the same preference are * sorted in the arriving time order. */ /* insert at the end of the group */ TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) if (rtpref(n) > rtpref(dr)) break; if (dr) TAILQ_INSERT_BEFORE(dr, n, dr_entry); else TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry); defrouter_select(); ext->ndefrouters++; return (n); } struct nd_pfxrouter * pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr) { struct nd_pfxrouter *search; LIST_FOREACH(search, &pr->ndpr_advrtrs, pfr_entry) { if (search->router == dr) break; } return (search); } void pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr) { struct nd_pfxrouter *new; new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO); if (new == NULL) return; new->router = dr; LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry); pfxlist_onlink_check(); } void pfxrtr_del(struct nd_pfxrouter *pfr) { LIST_REMOVE(pfr, pfr_entry); free(pfr, M_IP6NDP, sizeof(*pfr)); } struct nd_prefix * nd6_prefix_lookup(struct nd_prefix *pr) { struct nd_prefix *search; LIST_FOREACH(search, &nd_prefix, ndpr_entry) { 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); } void purge_detached(struct ifnet *ifp) { struct nd_prefix *pr, *pr_next; struct in6_ifaddr *ia6; struct ifaddr *ifa, *ifa_next; splsoftassert(IPL_SOFTNET); LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, pr_next) { /* * 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; TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, ifa_next) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; ia6 = ifatoia6(ifa); if ((ia6->ia6_flags & IN6_IFF_AUTOCONF) == IN6_IFF_AUTOCONF && ia6->ia6_ndpr == pr) { in6_purgeaddr(ifa); } } } } int nd6_prelist_add(struct nd_prefix *pr, struct nd_defrouter *dr, struct nd_prefix **newp) { struct nd_prefix *new = NULL; struct in6_ifextra *ext = pr->ndpr_ifp->if_afdata[AF_INET6]; int i; splsoftassert(IPL_SOFTNET); if (ip6_maxifprefixes >= 0) { if (ext->nprefixes >= ip6_maxifprefixes / 2) { purge_detached(pr->ndpr_ifp); } if (ext->nprefixes >= ip6_maxifprefixes) return(ENOMEM); } new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO); if (new == NULL) return ENOMEM; *new = *pr; if (newp != NULL) *newp = new; /* initialization */ 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]; task_set(&new->ndpr_task, nd6_addr_add, new); /* link ndpr_entry to nd_prefix list */ LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry); /* ND_OPT_PI_FLAG_ONLINK processing */ if (new->ndpr_raf_onlink) { char addr[INET6_ADDRSTRLEN]; int e; if ((e = nd6_prefix_onlink(new)) != 0) { nd6log((LOG_ERR, "%s: failed to make the prefix %s/%d" " on-link on %s (errno=%d)\n", __func__, inet_ntop(AF_INET6, &pr->ndpr_prefix.sin6_addr, addr, sizeof(addr)), pr->ndpr_plen, pr->ndpr_ifp->if_xname, e)); /* proceed anyway. XXX: is it correct? */ } } if (dr) pfxrtr_add(new, dr); ext->nprefixes++; return 0; } void prelist_remove(struct nd_prefix *pr) { struct nd_pfxrouter *pfr, *next; struct in6_ifextra *ext = pr->ndpr_ifp->if_afdata[AF_INET6]; int e; splsoftassert(IPL_SOFTNET); /* make sure to invalidate the prefix until it is really freed. */ pr->ndpr_vltime = 0; pr->ndpr_pltime = 0; if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 && (e = nd6_prefix_offlink(pr)) != 0) { char addr[INET6_ADDRSTRLEN]; nd6log((LOG_ERR, "%s: failed to make %s/%d offlink " "on %s, errno=%d\n", __func__, inet_ntop(AF_INET6, &pr->ndpr_prefix.sin6_addr, addr, sizeof(addr)), pr->ndpr_plen, pr->ndpr_ifp->if_xname, e)); /* what should we do? */ } if (pr->ndpr_refcnt > 0) return; /* notice here? */ /* unlink ndpr_entry from nd_prefix list */ LIST_REMOVE(pr, ndpr_entry); /* free list of routers that adversed the prefix */ LIST_FOREACH_SAFE(pfr, &pr->ndpr_advrtrs, pfr_entry, next) free(pfr, M_IP6NDP, sizeof(*pfr)); ext->nprefixes--; if (ext->nprefixes < 0) { log(LOG_WARNING, "%s: negative count on %s\n", __func__, pr->ndpr_ifp->if_xname); } free(pr, M_IP6NDP, sizeof(*pr)); pfxlist_onlink_check(); } /* * dr - may be NULL */ int prelist_update(struct nd_prefix *new, struct nd_defrouter *dr, struct mbuf *m) { struct in6_ifaddr *ia6_match = NULL; struct ifaddr *ifa; struct ifnet *ifp = new->ndpr_ifp; struct nd_prefix *pr; int error = 0; int tempaddr_preferred = 0, autoconf = 0, statique = 0; int auth; struct in6_addrlifetime lt6_tmp; char addr[INET6_ADDRSTRLEN]; splsoftassert(IPL_SOFTNET); auth = 0; if (m) { /* * Authenticity for NA consists authentication for * both IP header and IP datagrams, doesn't it ? */ auth = (m->m_flags & M_AUTH); } if ((pr = nd6_prefix_lookup(new)) != NULL) { /* * nd6_prefix_lookup() ensures that pr and new 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 (new->ndpr_raf_onlink == 1) pr->ndpr_raf_onlink = 1; if (new->ndpr_raf_auto == 1) pr->ndpr_raf_auto = 1; if (new->ndpr_raf_onlink) { pr->ndpr_vltime = new->ndpr_vltime; pr->ndpr_pltime = new->ndpr_pltime; pr->ndpr_preferred = new->ndpr_preferred; pr->ndpr_expire = new->ndpr_expire; pr->ndpr_lastupdate = new->ndpr_lastupdate; } if (new->ndpr_raf_onlink && (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) { int e; if ((e = nd6_prefix_onlink(pr)) != 0) { nd6log((LOG_ERR, "%s: failed to make the prefix" " %s/%d on-link on %s (errno=%d)\n", __func__, inet_ntop(AF_INET6, &pr->ndpr_prefix.sin6_addr, addr, sizeof(addr)), pr->ndpr_plen, pr->ndpr_ifp->if_xname, 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 (new->ndpr_vltime == 0) goto end; if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0) goto end; error = nd6_prelist_add(new, dr, &newpr); if (error != 0 || newpr == NULL) { nd6log((LOG_NOTICE, "%s: nd6_prelist_add failed for" " %s/%d on %s errno=%d, returnpr=%p\n", __func__, inet_ntop(AF_INET6, &new->ndpr_prefix.sin6_addr, addr, sizeof(addr)), new->ndpr_plen, new->ndpr_ifp->if_xname, error, newpr)); goto end; /* we should just give up in this case. */ } 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 (!new->ndpr_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. * This should have been done in nd6_ra_input. */ /* * 5.5.3 (d). If the prefix advertised does not match the prefix of an * address already in the list, and the Valid Lifetime is not 0, * form an address. Note that even a manually configured address * should reject autoconfiguration of a new address. */ TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { struct in6_ifaddr *ia6; int ifa_plen; u_int32_t storedlifetime; if (ifa->ifa_addr->sa_family != AF_INET6) continue; ia6 = ifatoia6(ifa); /* * 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; ifa_plen = in6_mask2len(&ia6->ia_prefixmask.sin6_addr, NULL); if (ifa_plen != new->ndpr_plen || !in6_are_prefix_equal(&ia6->ia_addr.sin6_addr, &new->ndpr_prefix.sin6_addr, ifa_plen)) continue; if (ia6_match == NULL) /* remember the first one */ ia6_match = ia6; if ((ia6->ia6_flags & IN6_IFF_AUTOCONF) == 0) { statique = 1; continue; } /* * 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. */ #define TWOHOUR (120*60) /* * RFC2462 introduces the notion of StoredLifetime to the * "two hours" rule as follows: * the Lifetime associated with the previously autoconfigured * address. * Our interpretation of this definition is "the remaining * lifetime to expiration at the evaluation time". One might * be wondering if this interpretation is really conform to the * RFC, because the text can read that "Lifetimes" are never * decreased, and our definition of the "storedlifetime" below * essentially reduces the "Valid Lifetime" advertised in the * previous RA. But, this is due to the wording of the text, * and our interpretation is the same as an author's intention. * See the discussion in the IETF ipngwg ML in August 2001, * with the Subject "StoredLifetime in RFC 2462". */ lt6_tmp = ia6->ia6_lifetime; /* RFC 4941 temporary addresses (privacy extension). */ if (ia6->ia6_flags & IN6_IFF_PRIVACY) { /* Do we still have a non-deprecated address? */ if ((ia6->ia6_flags & IN6_IFF_DEPRECATED) == 0) tempaddr_preferred = 1; /* Don't extend lifetime for temporary addresses. */ if (new->ndpr_vltime >= lt6_tmp.ia6t_vltime) continue; if (new->ndpr_pltime >= lt6_tmp.ia6t_pltime) continue; } else if ((ia6->ia6_flags & IN6_IFF_DEPRECATED) == 0) /* We have a regular SLAAC address. */ autoconf = 1; if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME) storedlifetime = 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. */ storedlifetime = 0; } else storedlifetime = lt6_tmp.ia6t_vltime - (time_uptime - ia6->ia6_updatetime); if (TWOHOUR < new->ndpr_vltime || storedlifetime < new->ndpr_vltime) { lt6_tmp.ia6t_vltime = new->ndpr_vltime; } else if (storedlifetime <= TWOHOUR #if 0 /* * This condition is logically redundant, so we just * omit it. * See IPng 6712, 6717, and 6721. */ && new->ndpr_vltime <= storedlifetime #endif ) { if (auth) { lt6_tmp.ia6t_vltime = new->ndpr_vltime; } } else { /* * new->ndpr_vltime <= TWOHOUR && * TWOHOUR < storedlifetime */ lt6_tmp.ia6t_vltime = TWOHOUR; } /* The 2 hour rule is not imposed for preferred lifetime. */ lt6_tmp.ia6t_pltime = new->ndpr_pltime; in6_init_address_ltimes(pr, <6_tmp); ia6->ia6_lifetime = lt6_tmp; ia6->ia6_updatetime = time_uptime; } if ((!autoconf || ((ifp->if_xflags & IFXF_INET6_NOPRIVACY) == 0 && !tempaddr_preferred)) && new->ndpr_vltime != 0 && new->ndpr_pltime != 0 && !((ifp->if_xflags & IFXF_INET6_NOPRIVACY) && statique)) { /* * There is no SLAAC address and/or there is no preferred RFC * 4941 temporary address. And prefix lifetimes are non-zero. * And there is no static address in the same prefix. * Create new addresses in process context. * Increment prefix refcount to ensure the prefix is not * removed before the task is done. */ pr->ndpr_refcnt++; if (task_add(systq, &pr->ndpr_task) == 0) pr->ndpr_refcnt--; } end: return error; } void nd6_addr_add(void *prptr) { struct nd_prefix *pr = (struct nd_prefix *)prptr; struct in6_ifaddr *ia6; struct ifaddr *ifa; int ifa_plen, autoconf, privacy, s; NET_LOCK(s); autoconf = 1; privacy = (pr->ndpr_ifp->if_xflags & IFXF_INET6_NOPRIVACY) == 0; /* * Check again if a non-deprecated address has already * been autoconfigured for this prefix. */ TAILQ_FOREACH(ifa, &pr->ndpr_ifp->if_addrlist, ifa_list) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; ia6 = ifatoia6(ifa); /* * 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; if ((ia6->ia6_flags & IN6_IFF_AUTOCONF) == 0) continue; if ((ia6->ia6_flags & IN6_IFF_DEPRECATED) != 0) continue; ifa_plen = in6_mask2len(&ia6->ia_prefixmask.sin6_addr, NULL); if (ifa_plen == pr->ndpr_plen && in6_are_prefix_equal(&ia6->ia_addr.sin6_addr, &pr->ndpr_prefix.sin6_addr, ifa_plen)) { if ((ia6->ia6_flags & IN6_IFF_PRIVACY) == 0) autoconf = 0; else privacy = 0; if (!autoconf && !privacy) break; } } if (autoconf && (ia6 = in6_ifadd(pr, 0)) != NULL) { ia6->ia6_ndpr = pr; pr->ndpr_refcnt++; } else autoconf = 0; if (privacy && (ia6 = in6_ifadd(pr, 1)) != NULL) { ia6->ia6_ndpr = pr; pr->ndpr_refcnt++; } else privacy = 0; /* * A newly added address might affect the status * of other addresses, so we check and update it. * XXX: what if address duplication happens? */ if (autoconf || privacy) pfxlist_onlink_check(); /* Decrement prefix refcount now that the task is done. */ if (--pr->ndpr_refcnt == 0) prelist_remove(pr); NET_UNLOCK(s); } /* * 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... */ struct nd_pfxrouter * find_pfxlist_reachable_router(struct nd_prefix *pr) { struct nd_pfxrouter *pfxrtr; struct rtentry *rt = NULL; struct llinfo_nd6 *ln; LIST_FOREACH(pfxrtr, &pr->ndpr_advrtrs, pfr_entry) { if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0, pfxrtr->router->ifp, pfxrtr->router->ifp->if_rdomain)) && (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && ND6_IS_LLINFO_PROBREACH(ln)) { rtfree(rt); break; /* found */ } rtfree(rt); } 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 pfxlist_onlink_check(void) { struct nd_prefix *pr; struct in6_ifaddr *ia6; char addr[INET6_ADDRSTRLEN]; /* * Check if there is a prefix that has a reachable advertising * router. */ LIST_FOREACH(pr, &nd_prefix, ndpr_entry) { if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr)) break; } if (pr != NULL || !TAILQ_EMPTY(&nd_defrouter)) { /* * 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. */ LIST_FOREACH(pr, &nd_prefix, ndpr_entry) { /* 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 */ LIST_FOREACH(pr, &nd_prefix, ndpr_entry) { 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. */ LIST_FOREACH(pr, &nd_prefix, ndpr_entry) { 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, "%s: failed to make %s/%d " "offlink, errno=%d\n", __func__, inet_ntop(AF_INET6, &pr->ndpr_prefix.sin6_addr, addr, sizeof(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, "%s: failed to make %s/%d " "offlink, errno=%d\n", __func__, inet_ntop(AF_INET6, &pr->ndpr_prefix.sin6_addr, addr, sizeof(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. */ TAILQ_FOREACH(ia6, &in6_ifaddr, ia_list) { if (!(ia6->ia6_flags & IN6_IFF_AUTOCONF)) continue; if (ia6->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(ia6->ia6_ndpr)) break; } if (ia6) { TAILQ_FOREACH(ia6, &in6_ifaddr, ia_list) { if ((ia6->ia6_flags & IN6_IFF_AUTOCONF) == 0) continue; if (ia6->ia6_ndpr == NULL) /* XXX: see above. */ continue; if (find_pfxlist_reachable_router(ia6->ia6_ndpr)) ia6->ia6_flags &= ~IN6_IFF_DETACHED; else ia6->ia6_flags |= IN6_IFF_DETACHED; } } else { TAILQ_FOREACH(ia6, &in6_ifaddr, ia_list) { if ((ia6->ia6_flags & IN6_IFF_AUTOCONF) == 0) continue; ia6->ia6_flags &= ~IN6_IFF_DETACHED; } } } int nd6_prefix_onlink(struct nd_prefix *pr) { struct ifnet *ifp = pr->ndpr_ifp; struct ifaddr *ifa; struct nd_prefix *opr; char addr[INET6_ADDRSTRLEN]; int error, rtflags = 0; /* sanity check */ if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) 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. */ LIST_FOREACH(opr, &nd_prefix, ndpr_entry) { 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); } TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; if (ifatoia6(ifa)->ia6_ndpr == pr) break; } 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, "nd6_prefix_onlink: failed to find any ifaddr" " to add route for a prefix(%s/%d) on %s\n", inet_ntop(AF_INET6, &pr->ndpr_prefix.sin6_addr, addr, sizeof(addr)), pr->ndpr_plen, ifp->if_xname)); return (0); } if (nd6_need_cache(ifp)) rtflags = RTF_CLONING | RTF_CONNECTED; error = rt_ifa_add(ifa, rtflags, sin6tosa(&pr->ndpr_prefix)); if (error == 0) pr->ndpr_stateflags |= NDPRF_ONLINK; return (error); } int nd6_prefix_offlink(struct nd_prefix *pr) { struct ifnet *ifp = pr->ndpr_ifp; struct ifaddr *ifa; struct nd_prefix *opr; char addr[INET6_ADDRSTRLEN]; int error, rtflags = 0; /* sanity check */ if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) { nd6log((LOG_ERR, "nd6_prefix_offlink: %s/%d is already off-link\n", inet_ntop(AF_INET6, &pr->ndpr_prefix.sin6_addr, addr, sizeof(addr)), pr->ndpr_plen)); return (EEXIST); } TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; if (ifatoia6(ifa)->ia6_ndpr == pr) break; } if (ifa == NULL) return (EINVAL); if (nd6_need_cache(ifp)) rtflags = RTF_CLONING | RTF_CONNECTED; error = rt_ifa_del(ifa, rtflags, sin6tosa(&pr->ndpr_prefix)); if (error == 0) { pr->ndpr_stateflags &= ~NDPRF_ONLINK; /* * 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. */ LIST_FOREACH(opr, &nd_prefix, ndpr_entry) { 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, "nd6_prefix_offlink: failed to " "recover a prefix %s/%d from %s " "to %s (errno = %d)\n", inet_ntop(AF_INET6, &pr->ndpr_prefix.sin6_addr, addr, sizeof(addr)), opr->ndpr_plen, ifp->if_xname, opr->ndpr_ifp->if_xname, e)); } } } } return (error); } struct in6_ifaddr * in6_ifadd(struct nd_prefix *pr, int privacy) { struct ifnet *ifp = pr->ndpr_ifp; struct ifaddr *ifa; struct in6_aliasreq ifra; struct in6_ifaddr *ia6; int error, plen0; struct in6_addr mask, rand_ifid; int prefixlen = pr->ndpr_plen; splsoftassert(IPL_SOFTNET); 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 a 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. */ ifa = &in6ifa_ifpforlinklocal(ifp, 0)->ia_ifa; /* 0 is OK? */ if (ifa) ia6 = ifatoia6(ifa); else return NULL; /* prefixlen + ifidlen must be equal to 128 */ plen0 = in6_mask2len(&ia6->ia_prefixmask.sin6_addr, NULL); if (prefixlen != plen0) { nd6log((LOG_INFO, "%s: wrong prefixlen for %s " "(prefix=%d ifid=%d)\n", __func__, ifp->if_xname, prefixlen, 128 - plen0)); return NULL; } /* make ifaddr */ bzero(&ifra, sizeof(ifra)); strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); ifra.ifra_addr.sin6_family = AF_INET6; ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); /* prefix */ bcopy(&pr->ndpr_prefix.sin6_addr, &ifra.ifra_addr.sin6_addr, sizeof(ifra.ifra_addr.sin6_addr)); 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 */ if (privacy) { ifra.ifra_flags |= IN6_IFF_PRIVACY; bcopy(&pr->ndpr_prefix.sin6_addr, &rand_ifid, sizeof(rand_ifid)); in6_get_rand_ifid(ifp, &rand_ifid); ifra.ifra_addr.sin6_addr.s6_addr32[0] |= (rand_ifid.s6_addr32[0] & ~mask.s6_addr32[0]); ifra.ifra_addr.sin6_addr.s6_addr32[1] |= (rand_ifid.s6_addr32[1] & ~mask.s6_addr32[1]); ifra.ifra_addr.sin6_addr.s6_addr32[2] |= (rand_ifid.s6_addr32[2] & ~mask.s6_addr32[2]); ifra.ifra_addr.sin6_addr.s6_addr32[3] |= (rand_ifid.s6_addr32[3] & ~mask.s6_addr32[3]); } else { ifra.ifra_addr.sin6_addr.s6_addr32[0] |= (ia6->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]); ifra.ifra_addr.sin6_addr.s6_addr32[1] |= (ia6->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]); ifra.ifra_addr.sin6_addr.s6_addr32[2] |= (ia6->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]); ifra.ifra_addr.sin6_addr.s6_addr32[3] |= (ia6->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]); } /* new prefix mask. */ ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); ifra.ifra_prefixmask.sin6_family = AF_INET6; bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr, sizeof(ifra.ifra_prefixmask.sin6_addr)); /* * lifetime. * XXX: in6_init_address_ltimes would override these values later. * We should reconsider this logic. */ ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime; ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime; if (privacy) { if (ifra.ifra_lifetime.ia6t_vltime > ND6_PRIV_VALID_LIFETIME) ifra.ifra_lifetime.ia6t_vltime = ND6_PRIV_VALID_LIFETIME; if (ifra.ifra_lifetime.ia6t_pltime > ND6_PRIV_PREFERRED_LIFETIME) ifra.ifra_lifetime.ia6t_pltime = ND6_PRIV_PREFERRED_LIFETIME - arc4random_uniform(ND6_PRIV_MAX_DESYNC_FACTOR); } /* XXX: scope zone ID? */ ifra.ifra_flags |= IN6_IFF_AUTOCONF|IN6_IFF_TENTATIVE; /* If this address already exists, update it. */ ia6 = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr); error = in6_update_ifa(ifp, &ifra, ia6); if (error != 0) { char addr[INET6_ADDRSTRLEN]; nd6log((LOG_ERR, "%s: failed to make ifaddr %s on %s (errno=%d)\n", __func__, inet_ntop(AF_INET6, &ifra.ifra_addr.sin6_addr, addr, sizeof(addr)), ifp->if_xname, error)); return (NULL); /* ifaddr must not have been allocated. */ } ia6 = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr); /* Perform DAD, if needed. */ if (ia6 != NULL && ia6->ia6_flags & IN6_IFF_TENTATIVE) nd6_dad_start(&ia6->ia_ifa); return (ia6); } int in6_init_prefix_ltimes(struct nd_prefix *ndpr) { /* check if preferred lifetime > valid lifetime. RFC2462 5.5.3 (c) */ if (ndpr->ndpr_pltime > ndpr->ndpr_vltime) { nd6log((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_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; } void in6_init_address_ltimes(struct nd_prefix *new, 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 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp) { splsoftassert(IPL_SOFTNET); /* We'll care only link-local addresses */ if (!IN6_IS_ADDR_LINKLOCAL(gateway)) return; /* XXX: hack for KAME's link-local address kludge */ gateway->s6_addr16[1] = htons(ifp->if_index); rtable_walk(ifp->if_rdomain, AF_INET6, rt6_deleteroute, gateway); } int rt6_deleteroute(struct rtentry *rt, void *arg, unsigned int id) { struct rt_addrinfo info; struct in6_addr *gate = (struct in6_addr *)arg; struct sockaddr_in6 sa_mask; int error; 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); bzero(&info, sizeof(info)); info.rti_flags = rt->rt_flags; info.rti_info[RTAX_DST] = rt_key(rt); info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; info.rti_info[RTAX_NETMASK] = rt_plen2mask(rt, &sa_mask); error = rtrequest(RTM_DELETE, &info, RTP_ANY, NULL, id); if (error != 0) return (error); return (EAGAIN); }