/* $OpenBSD: nd6_rtr.c,v 1.65 2012/09/26 14:53:23 markus 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 #include #include #define SDL(s) ((struct sockaddr_dl *)s) 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 nd6_rtmsg(int, struct rtentry *); void purge_detached(struct ifnet *); void in6_init_address_ltimes(struct nd_prefix *, struct in6_addrlifetime *); int rt6_deleteroute(struct radix_node *, void *, u_int); void nd6_addr_add(void *, void *); extern int nd6_recalc_reachtm_interval; static struct ifnet *nd6_defifp; int nd6_defifindex; /* * Receive Router Solicitation Message - just for routers. * Router solicitation/advertisement is mostly managed by userland program * (rtadvd) so here we have no function like nd6_ra_output(). * * Based on RFC 2461 */ void nd6_rs_input(struct mbuf *m, int off, int icmp6len) { struct ifnet *ifp = m->m_pkthdr.rcvif; 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 = (struct sockaddr_dl *)NULL; struct llinfo_nd6 *ln = (struct llinfo_nd6 *)NULL; struct rtentry *rt = NULL; int is_newentry; #endif union nd_opts ndopts; /* If I'm not a router, ignore it. */ if (ip6_accept_rtadv != 0 || !ip6_forwarding) goto freeit; /* Sanity checks */ if (ip6->ip6_hlim != 255) { nd6log((LOG_ERR, "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n", ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_dst), ifp->if_xname)); 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; } 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", ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2)); goto bad; } nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0); freeit: m_freem(m); return; bad: icmp6stat.icp6s_badrs++; 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 = m->m_pkthdr.rcvif; struct nd_ifinfo *ndi = ND_IFINFO(ifp); 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 union nd_opts ndopts; struct nd_defrouter *dr; /* * We only accept RAs only when * the system-wide variable allows the acceptance, and * per-interface variable allows RAs on the receiving interface. */ if (ip6_accept_rtadv == 0) goto freeit; if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV)) goto freeit; if (ip6->ip6_hlim != 255) { nd6log((LOG_ERR, "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n", ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_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", ip6_sprintf(&saddr6))); goto bad; } IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len); if (nd_ra == NULL) { icmp6stat.icp6s_tooshort++; 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; Bzero(&dr0, 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_second + dr0.rtlifetime; dr0.ifp = ifp; /* unspecified or not? (RFC 2461 6.3.4) */ if (advreachable) { NTOHL(advreachable); if (advreachable <= MAX_REACHABLE_TIME && ndi->basereachable != advreachable) { ndi->basereachable = advreachable; ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable); ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */ } } if (nd_ra->nd_ra_retransmit) ndi->retrans = ntohl(nd_ra->nd_ra_retransmit); if (nd_ra->nd_ra_curhoplimit) ndi->chlim = nd_ra->nd_ra_curhoplimit; dr = defrtrlist_update(&dr0); } /* * prefix */ if (ndopts.nd_opts_pi) { struct nd_opt_hdr *pt; struct nd_opt_prefix_info *pi = 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", ip6_sprintf(&pi->nd_opt_pi_prefix))); continue; } /* aggregatable unicast address, rfc2374 */ if ((pi->nd_opt_pi_prefix.s6_addr8[0] & 0xe0) == 0x20 && pi->nd_opt_pi_prefix_len != 64) { nd6log((LOG_INFO, "nd6_ra_input: invalid prefixlen " "%d for rfc2374 prefix %s, ignored\n", pi->nd_opt_pi_prefix_len, ip6_sprintf(&pi->nd_opt_pi_prefix))); continue; } bzero(&pr, sizeof(pr)); pr.ndpr_prefix.sin6_family = AF_INET6; pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix); pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix; pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif; pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK) ? 1 : 0; pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) ? 1 : 0; pr.ndpr_plen = pi->nd_opt_pi_prefix_len; pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time); pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time); pr.ndpr_lastupdate = time_second; if (in6_init_prefix_ltimes(&pr)) continue; /* prefix lifetime init failed */ (void)prelist_update(&pr, dr, m); } } /* * MTU */ if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) { u_long mtu; u_long maxmtu; mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu); /* lower bound */ if (mtu < IPV6_MMTU) { nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option " "mtu=%lu sent from %s, ignoring\n", mtu, ip6_sprintf(&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, "nd6_ra_input: bogus mtu " "mtu=%lu sent from %s; " "exceeds maxmtu %lu, ignoring\n", mtu, ip6_sprintf(&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, "nd6_ra_input: lladdrlen mismatch for %s " "(if %d, RA packet %d)\n", ip6_sprintf(&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. */ pfxlist_onlink_check(); } freeit: m_freem(m); return; bad: icmp6stat.icp6s_badra++; m_freem(m); } /* * default router list processing sub routines */ /* tell the change to user processes watching the routing socket. */ void nd6_rtmsg(int cmd, struct rtentry *rt) { struct rt_addrinfo info; bzero((caddr_t)&info, sizeof(info)); info.rti_info[RTAX_DST] = rt_key(rt); info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; info.rti_info[RTAX_NETMASK] = rt_mask(rt); if (rt->rt_ifp) { info.rti_info[RTAX_IFP] = TAILQ_FIRST(&rt->rt_ifp->if_addrlist)->ifa_addr; info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr; } rt_missmsg(cmd, &info, rt->rt_flags, rt->rt_ifp, 0, 0); } void defrouter_addreq(struct nd_defrouter *new) { struct rt_addrinfo info; struct sockaddr_in6 def, mask, gate; struct rtentry *newrt = NULL; int s; int error; Bzero(&def, sizeof(def)); Bzero(&mask, sizeof(mask)); Bzero(&gate, sizeof(gate)); /* for safety */ Bzero(&info, 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_flags = RTF_GATEWAY; info.rti_info[RTAX_DST] = (struct sockaddr *)&def; info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gate; info.rti_info[RTAX_NETMASK] = (struct sockaddr *)&mask; s = splsoftnet(); error = rtrequest1(RTM_ADD, &info, RTP_DEFAULT, &newrt, new->ifp->if_rdomain); if (newrt) { nd6_rtmsg(RTM_ADD, newrt); /* tell user process */ newrt->rt_refcnt--; } if (error == 0) new->installed = 1; splx(s); return; } struct nd_defrouter * defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp) { struct nd_defrouter *dr; TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) if (dr->ifp == ifp && 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. */ if (!ip6_forwarding && ip6_accept_rtadv) /* XXX: better condition? */ 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, "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 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 *oldrt = NULL; #ifdef DIAGNOSTIC if (!dr) panic("dr == NULL in defrouter_delreq"); #endif Bzero(&info, sizeof(info)); Bzero(&def, sizeof(def)); Bzero(&mask, sizeof(mask)); Bzero(&gw, 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] = (struct sockaddr *)&def; info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw; info.rti_info[RTAX_NETMASK] = (struct sockaddr *)&mask; rtrequest1(RTM_DELETE, &info, RTP_DEFAULT, &oldrt, dr->ifp->if_rdomain); if (oldrt) { nd6_rtmsg(RTM_DELETE, oldrt); if (oldrt->rt_refcnt <= 0) { /* * XXX: borrowed from the RTM_DELETE case of * rtrequest1(). */ oldrt->rt_refcnt++; rtfree(oldrt); } } 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 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 defrouter_select(void) { int s = splsoftnet(); struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL; struct rtentry *rt = NULL; struct llinfo_nd6 *ln = NULL; /* * 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 || !ip6_accept_rtadv) { nd6log((LOG_WARNING, "defrouter_select: called unexpectedly (forwarding=%d, " "accept_rtadv=%d)\n", ip6_forwarding, ip6_accept_rtadv)); splx(s); return; } /* * Let's handle easy case (3) first: * If default router list is empty, there's nothing to be done. */ if (TAILQ_EMPTY(&nd_defrouter)) { splx(s); 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 (!selected_dr && (rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) && (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && ND6_IS_LLINFO_PROBREACH(ln)) { 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, "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)) && (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && ND6_IS_LLINFO_PROBREACH(ln) && 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); } splx(s); return; } /* * 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]; int s = splsoftnet(); if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != 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) { splx(s); 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; } splx(s); return (dr); } /* entry does not exist */ if (new->rtlifetime == 0) { /* flush all possible redirects */ if (!ip6_forwarding && ip6_accept_rtadv) rt6_flush(&new->rtaddr, new->ifp); splx(s); return (NULL); } if (ip6_maxifdefrouters >= 0 && ext->ndefrouters >= ip6_maxifdefrouters) { splx(s); return (NULL); } n = malloc(sizeof(*n), M_IP6NDP, M_NOWAIT | M_ZERO); if (n == NULL) { splx(s); 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++; splx(s); 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); } 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 *ia; struct ifaddr *ifa, *ifa_next; for (pr = nd_prefix.lh_first; pr; pr = pr_next) { pr_next = pr->ndpr_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; for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa_next) { ifa_next = ifa->ifa_list.tqe_next; 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) { in6_purgeaddr(ifa); } } } } int nd6_prelist_add(struct nd_prefix *pr, struct nd_defrouter *dr, struct nd_prefix **newp) { struct nd_prefix *new = NULL; int i, s; struct in6_ifextra *ext = pr->ndpr_ifp->if_afdata[AF_INET6]; 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]; s = splsoftnet(); /* link ndpr_entry to nd_prefix list */ LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry); splx(s); /* ND_OPT_PI_FLAG_ONLINK processing */ if (new->ndpr_raf_onlink) { int e; if ((e = nd6_prefix_onlink(new)) != 0) { nd6log((LOG_ERR, "nd6_prelist_add: failed to make " "the prefix %s/%d on-link on %s (errno=%d)\n", ip6_sprintf(&pr->ndpr_prefix.sin6_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; int e, s; struct in6_ifextra *ext = pr->ndpr_ifp->if_afdata[AF_INET6]; /* 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) { nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink " "on %s, errno=%d\n", ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen, pr->ndpr_ifp->if_xname, e)); /* what should we do? */ } if (pr->ndpr_refcnt > 0) return; /* notice here? */ s = splsoftnet(); /* unlink ndpr_entry from nd_prefix list */ LIST_REMOVE(pr, ndpr_entry); /* 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); } ext->nprefixes--; if (ext->nprefixes < 0) { log(LOG_WARNING, "prelist_remove: negative count on %s\n", pr->ndpr_ifp->if_xname); } splx(s); free(pr, M_IP6NDP); 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 s = splsoftnet(); int error = 0; int tempaddr_preferred = 0, autoconf = 0, statique = 0; int auth; struct in6_addrlifetime lt6_tmp; 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, "prelist_update: failed to make " "the prefix %s/%d on-link on %s " "(errno=%d)\n", ip6_sprintf(&pr->ndpr_prefix.sin6_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, "prelist_update: " "nd6_prelist_add failed for %s/%d on %s " "errno=%d, returnpr=%p\n", ip6_sprintf(&new->ndpr_prefix.sin6_addr), new->ndpr_plen, new->ndpr_ifp->if_xname, 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 (!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 *ifa6; int ifa_plen; u_int32_t storedlifetime; if (ifa->ifa_addr->sa_family != AF_INET6) continue; ifa6 = (struct in6_ifaddr *)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 ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0) continue; ifa_plen = in6_mask2len(&ifa6->ia_prefixmask.sin6_addr, NULL); if (ifa_plen != new->ndpr_plen || !in6_are_prefix_equal(&ifa6->ia_addr.sin6_addr, &new->ndpr_prefix.sin6_addr, ifa_plen)) continue; if (ia6_match == NULL) /* remember the first one */ ia6_match = ifa6; if ((ifa6->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 = ifa6->ia6_lifetime; /* RFC 4941 temporary addresses (privacy extension). */ if (ifa6->ia6_flags & IN6_IFF_PRIVACY) { /* Do we still have a non-deprecated address? */ if ((ifa6->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 ((ifa6->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_second - ifa6->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_second - ifa6->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); ifa6->ia6_lifetime = lt6_tmp; ifa6->ia6_updatetime = time_second; } if ((!autoconf || ((ifp->if_xflags & IFXF_INET6_NOPRIVACY) == 0 && !tempaddr_preferred)) && new->ndpr_vltime != 0 && !((ifp->if_xflags & IFXF_INET6_NOPRIVACY) && statique)) { /* * There is no SLAAC address and/or there is no preferred RFC * 4941 temporary address. And the valid prefix lifetime is * non-zero. And there is no static address in the same prefix. * Create new addresses in process context. */ pr->ndpr_refcnt++; if (workq_add_task(NULL, 0, nd6_addr_add, pr, NULL)) pr->ndpr_refcnt--; } end: splx(s); return error; } void nd6_addr_add(void *prptr, void *arg2) { struct nd_prefix *pr = (struct nd_prefix *)prptr; struct in6_ifaddr *ia6 = NULL; struct ifaddr *ifa; int ifa_plen, autoconf, privacy, s; s = splsoftnet(); autoconf = 1; privacy = (pr->ndpr_ifp->if_xflags & IFXF_INET6_NOPRIVACY) == 0; /* Because prelist_update() runs in interrupt context it may run * again before this work queue task is run, causing multiple work * queue tasks to be scheduled all of which add addresses for the * same prefix. So 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 = (struct in6_ifaddr *)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(); pr->ndpr_refcnt--; splx(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; struct llinfo_nd6 *ln; for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr; pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) { if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0, pfxrtr->router->ifp)) && (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && ND6_IS_LLINFO_PROBREACH(ln)) break; /* found */ } return (pfxrtr); } /* * Check if each prefix in the prefix list has at least one available router * that advertised the prefix (a router is "available" if its neighbor cache * entry 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 *ifa; /* * 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, "pfxlist_onlink_check: failed to " "make %s/%d offlink, errno=%d\n", ip6_sprintf(&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, "pfxlist_onlink_check: failed to " "make %s/%d offlink, errno=%d\n", ip6_sprintf(&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. */ for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) { if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF)) continue; if (ifa->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(ifa->ia6_ndpr)) break; } if (ifa) { for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) { if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0) continue; if (ifa->ia6_ndpr == NULL) /* XXX: see above. */ continue; if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) ifa->ia6_flags &= ~IN6_IFF_DETACHED; else ifa->ia6_flags |= IN6_IFF_DETACHED; } } else { for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) { if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0) continue; ifa->ia6_flags &= ~IN6_IFF_DETACHED; } } } int nd6_prefix_onlink(struct nd_prefix *pr) { struct rt_addrinfo info; struct ifaddr *ifa; struct ifnet *ifp = pr->ndpr_ifp; struct sockaddr_in6 mask6; struct nd_prefix *opr; u_long rtflags; int error = 0; struct rtentry *rt = NULL; /* sanity check */ if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) { nd6log((LOG_ERR, "nd6_prefix_onlink: %s/%d is already on-link\n", ip6_sprintf(&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. */ 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); } /* * We prefer link-local addresses as the associated interface address. */ /* search for a link-local addr */ ifa = &in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY | IN6_IFF_ANYCAST)->ia_ifa; if (ifa == NULL) { /* XXX: freebsd does not have ifa_ifwithaf */ TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { if (ifa->ifa_addr->sa_family == AF_INET6) break; } /* 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, "nd6_prefix_onlink: failed to find any ifaddr" " to add route for a prefix(%s/%d) on %s\n", ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen, ifp->if_xname)); return (0); } /* * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs. * ifa->ifa_rtrequest = nd6_rtrequest; */ bzero(&mask6, sizeof(mask6)); mask6.sin6_len = sizeof(mask6); mask6.sin6_addr = pr->ndpr_mask; /* rtrequest1() 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_CLONING; } else { /* * explicitly clear the cloning bit in case ifa_flags sets it. */ rtflags &= ~RTF_CLONING; } bzero(&info, sizeof(info)); info.rti_flags = rtflags; info.rti_info[RTAX_DST] = (struct sockaddr *)&pr->ndpr_prefix; info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr; info.rti_info[RTAX_NETMASK] = (struct sockaddr *)&mask6; error = rtrequest1(RTM_ADD, &info, RTP_CONNECTED, &rt, ifp->if_rdomain); if (error == 0) { if (rt != NULL) /* this should be non NULL, though */ nd6_rtmsg(RTM_ADD, rt); pr->ndpr_stateflags |= NDPRF_ONLINK; } else { nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a" " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx " "errno = %d\n", ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen, ifp->if_xname, ip6_sprintf(&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr), ip6_sprintf(&mask6.sin6_addr), rtflags, error)); } if (rt != NULL) rt->rt_refcnt--; return (error); } int nd6_prefix_offlink(struct nd_prefix *pr) { struct rt_addrinfo info; int error = 0; struct ifnet *ifp = pr->ndpr_ifp; struct nd_prefix *opr; struct sockaddr_in6 sa6, mask6; struct rtentry *rt = NULL; /* sanity check */ if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) { nd6log((LOG_ERR, "nd6_prefix_offlink: %s/%d is already off-link\n", ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen)); return (EEXIST); } bzero(&sa6, sizeof(sa6)); sa6.sin6_family = AF_INET6; sa6.sin6_len = sizeof(sa6); bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr, sizeof(struct in6_addr)); bzero(&mask6, sizeof(mask6)); mask6.sin6_family = AF_INET6; mask6.sin6_len = sizeof(sa6); bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr)); bzero(&info, sizeof(info)); info.rti_info[RTAX_DST] = (struct sockaddr *)&sa6; info.rti_info[RTAX_NETMASK] = (struct sockaddr *)&mask6; error = rtrequest1(RTM_DELETE, &info, RTP_CONNECTED, &rt, ifp->if_rdomain); if (error == 0) { pr->ndpr_stateflags &= ~NDPRF_ONLINK; /* report the route deletion to the routing socket. */ if (rt != NULL) nd6_rtmsg(RTM_DELETE, rt); /* * 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", ip6_sprintf(&opr->ndpr_prefix.sin6_addr), opr->ndpr_plen, ifp->if_xname, opr->ndpr_ifp->if_xname, e)); } } } } else { /* XXX: can we still set the NDPRF_ONLINK flag? */ nd6log((LOG_ERR, "nd6_prefix_offlink: failed to delete route: " "%s/%d on %s (errno = %d)\n", ip6_sprintf(&sa6.sin6_addr), pr->ndpr_plen, ifp->if_xname, error)); } if (rt != NULL) { if (rt->rt_refcnt <= 0) { /* XXX: we should free the entry ourselves. */ rt->rt_refcnt++; rtfree(rt); } } 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 *ia, *ib; int error, s, plen0; struct in6_addr mask, rand_ifid; int prefixlen = pr->ndpr_plen; 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) ib = (struct in6_ifaddr *)ifa; else return NULL; #if 0 /* don't care link local addr state, and always do DAD */ /* if link-local address is not eligible, do not autoconfigure. */ if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY) { printf("in6_ifadd: link-local address not ready\n"); return NULL; } #endif /* prefixlen + ifidlen must be equal to 128 */ plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL); if (prefixlen != plen0) { nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s " "(prefix=%d ifid=%d)\n", ifp->if_xname, prefixlen, 128 - plen0)); return NULL; } /* make ifaddr */ bzero(&ifra, sizeof(ifra)); /* * in6_update_ifa() does not use ifra_name, but we accurately set it * for safety. */ 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] |= (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]); } /* 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() % ND6_PRIV_MAX_DESYNC_FACTOR); } /* XXX: scope zone ID? */ ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */ /* allocate ifaddr structure, link into chain, etc. */ s = splsoftnet(); error = in6_update_ifa(ifp, &ifra, NULL); splx(s); if (error != 0) { nd6log((LOG_ERR, "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n", ip6_sprintf(&ifra.ifra_addr.sin6_addr), ifp->if_xname, error)); return (NULL); /* ifaddr must not have been allocated. */ } ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr); return (ia); /* this is always non-NULL */ } 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_second + ndpr->ndpr_pltime; if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME) ndpr->ndpr_expire = 0; else ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime; return 0; } 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_second; 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_second; 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) { struct radix_node_head *rnh = rt_gettable(AF_INET6, 0); int s = splsoftnet(); /* We'll care only link-local addresses */ if (!IN6_IS_ADDR_LINKLOCAL(gateway)) { splx(s); return; } /* XXX: hack for KAME's link-local address kludge */ gateway->s6_addr16[1] = htons(ifp->if_index); rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway); splx(s); } int rt6_deleteroute(struct radix_node *rn, void *arg, u_int id) { #define SIN6(s) ((struct sockaddr_in6 *)s) struct rt_addrinfo info; struct rtentry *rt = (struct rtentry *)rn; struct in6_addr *gate = (struct in6_addr *)arg; if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6) return (0); if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr)) return (0); /* * 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_mask(rt); return (rtrequest1(RTM_DELETE, &info, RTP_ANY, NULL, id)); #undef SIN6 } int nd6_setdefaultiface(int ifindex) { int error = 0; if (ifindex < 0 || if_indexlim <= ifindex) return (EINVAL); if (ifindex != 0 && !ifindex2ifnet[ifindex]) return (EINVAL); if (nd6_defifindex != ifindex) { nd6_defifindex = ifindex; if (nd6_defifindex > 0) { nd6_defifp = ifindex2ifnet[nd6_defifindex]; } else nd6_defifp = NULL; } return (error); }