/* $NetBSD: nd6.c,v 1.48 2001/06/27 17:36:14 itojun Exp $ */ /* $KAME: nd6.c,v 1.151 2001/06/19 14:24:41 sumikawa 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. */ /* * XXX * KAME 970409 note: * BSD/OS version heavily modifies this code, related to llinfo. * Since we don't have BSD/OS version of net/route.c in our hand, * I left the code mostly as it was in 970310. -- itojun */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "loop.h" extern struct ifnet loif[NLOOP]; #include #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */ #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */ #define SIN6(s) ((struct sockaddr_in6 *)s) #define SDL(s) ((struct sockaddr_dl *)s) /* timer values */ int nd6_prune = 1; /* walk list every 1 seconds */ int nd6_delay = 5; /* delay first probe time 5 second */ int nd6_umaxtries = 3; /* maximum unicast query */ int nd6_mmaxtries = 3; /* maximum multicast query */ int nd6_useloopback = 1; /* use loopback interface for local traffic */ int nd6_gctimer = (60 * 60 * 24); /* 1 day: garbage collection timer */ /* preventing too many loops in ND option parsing */ int nd6_maxndopt = 10; /* max # of ND options allowed */ int nd6_maxnudhint = 0; /* max # of subsequent upper layer hints */ #ifdef ND6_DEBUG int nd6_debug = 1; #else int nd6_debug = 0; #endif /* for debugging? */ static int nd6_inuse, nd6_allocated; struct llinfo_nd6 llinfo_nd6 = {&llinfo_nd6, &llinfo_nd6}; static size_t nd_ifinfo_indexlim = 8; struct nd_ifinfo *nd_ifinfo = NULL; struct nd_drhead nd_defrouter; struct nd_prhead nd_prefix = { 0 }; int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL; static struct sockaddr_in6 all1_sa; static void nd6_slowtimo __P((void *)); struct callout nd6_slowtimo_ch; struct callout nd6_timer_ch; void nd6_init() { static int nd6_init_done = 0; int i; if (nd6_init_done) { log(LOG_NOTICE, "nd6_init called more than once(ignored)\n"); return; } all1_sa.sin6_family = AF_INET6; all1_sa.sin6_len = sizeof(struct sockaddr_in6); for (i = 0; i < sizeof(all1_sa.sin6_addr); i++) all1_sa.sin6_addr.s6_addr[i] = 0xff; /* initialization of the default router list */ TAILQ_INIT(&nd_defrouter); nd6_init_done = 1; /* start timer */ callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz, nd6_slowtimo, NULL); } void nd6_ifattach(ifp) struct ifnet *ifp; { /* * We have some arrays that should be indexed by if_index. * since if_index will grow dynamically, they should grow too. */ if (nd_ifinfo == NULL || if_index >= nd_ifinfo_indexlim) { size_t n; caddr_t q; while (if_index >= nd_ifinfo_indexlim) nd_ifinfo_indexlim <<= 1; /* grow nd_ifinfo */ n = nd_ifinfo_indexlim * sizeof(struct nd_ifinfo); q = (caddr_t)malloc(n, M_IP6NDP, M_WAITOK); bzero(q, n); if (nd_ifinfo) { bcopy((caddr_t)nd_ifinfo, q, n/2); free((caddr_t)nd_ifinfo, M_IP6NDP); } nd_ifinfo = (struct nd_ifinfo *)q; } #define ND nd_ifinfo[ifp->if_index] /* * Don't initialize if called twice. * XXX: to detect this, we should choose a member that is never set * before initialization of the ND structure itself. We formaly used * the linkmtu member, which was not suitable because it could be * initialized via "ifconfig mtu". */ if (ND.basereachable) return; ND.linkmtu = ifindex2ifnet[ifp->if_index]->if_mtu; ND.chlim = IPV6_DEFHLIM; ND.basereachable = REACHABLE_TIME; ND.reachable = ND_COMPUTE_RTIME(ND.basereachable); ND.retrans = RETRANS_TIMER; ND.receivedra = 0; ND.flags = ND6_IFF_PERFORMNUD; nd6_setmtu(ifp); #undef ND } /* * Reset ND level link MTU. This function is called when the physical MTU * changes, which means we might have to adjust the ND level MTU. */ void nd6_setmtu(ifp) struct ifnet *ifp; { struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index]; u_long oldmaxmtu = ndi->maxmtu; u_long oldlinkmtu = ndi->linkmtu; switch (ifp->if_type) { case IFT_ARCNET: /* XXX MTU handling needs more work */ ndi->maxmtu = MIN(60480, ifp->if_mtu); break; case IFT_ETHER: ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu); break; case IFT_ATM: ndi->maxmtu = MIN(ATMMTU, ifp->if_mtu); break; case IFT_IEEE1394: ndi->maxmtu = MIN(IEEE1394MTU, ifp->if_mtu); break; default: ndi->maxmtu = ifp->if_mtu; break; } if (oldmaxmtu != ndi->maxmtu) { /* * If the ND level MTU is not set yet, or if the maxmtu * is reset to a smaller value than the ND level MTU, * also reset the ND level MTU. */ if (ndi->linkmtu == 0 || ndi->maxmtu < ndi->linkmtu) { ndi->linkmtu = ndi->maxmtu; /* also adjust in6_maxmtu if necessary. */ if (oldlinkmtu == 0) { /* * XXX: the case analysis is grotty, but * it is not efficient to call in6_setmaxmtu() * here when we are during the initialization * procedure. */ if (in6_maxmtu < ndi->linkmtu) in6_maxmtu = ndi->linkmtu; } else in6_setmaxmtu(); } } #undef MIN } void nd6_option_init(opt, icmp6len, ndopts) void *opt; int icmp6len; union nd_opts *ndopts; { bzero(ndopts, sizeof(*ndopts)); ndopts->nd_opts_search = (struct nd_opt_hdr *)opt; ndopts->nd_opts_last = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len); if (icmp6len == 0) { ndopts->nd_opts_done = 1; ndopts->nd_opts_search = NULL; } } /* * Take one ND option. */ struct nd_opt_hdr * nd6_option(ndopts) union nd_opts *ndopts; { struct nd_opt_hdr *nd_opt; int olen; if (!ndopts) panic("ndopts == NULL in nd6_option\n"); if (!ndopts->nd_opts_last) panic("uninitialized ndopts in nd6_option\n"); if (!ndopts->nd_opts_search) return NULL; if (ndopts->nd_opts_done) return NULL; nd_opt = ndopts->nd_opts_search; /* make sure nd_opt_len is inside the buffer */ if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) { bzero(ndopts, sizeof(*ndopts)); return NULL; } olen = nd_opt->nd_opt_len << 3; if (olen == 0) { /* * Message validation requires that all included * options have a length that is greater than zero. */ bzero(ndopts, sizeof(*ndopts)); return NULL; } ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen); if (ndopts->nd_opts_search > ndopts->nd_opts_last) { /* option overruns the end of buffer, invalid */ bzero(ndopts, sizeof(*ndopts)); return NULL; } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) { /* reached the end of options chain */ ndopts->nd_opts_done = 1; ndopts->nd_opts_search = NULL; } return nd_opt; } /* * Parse multiple ND options. * This function is much easier to use, for ND routines that do not need * multiple options of the same type. */ int nd6_options(ndopts) union nd_opts *ndopts; { struct nd_opt_hdr *nd_opt; int i = 0; if (!ndopts) panic("ndopts == NULL in nd6_options\n"); if (!ndopts->nd_opts_last) panic("uninitialized ndopts in nd6_options\n"); if (!ndopts->nd_opts_search) return 0; while (1) { nd_opt = nd6_option(ndopts); if (!nd_opt && !ndopts->nd_opts_last) { /* * Message validation requires that all included * options have a length that is greater than zero. */ icmp6stat.icp6s_nd_badopt++; bzero(ndopts, sizeof(*ndopts)); return -1; } if (!nd_opt) goto skip1; switch (nd_opt->nd_opt_type) { case ND_OPT_SOURCE_LINKADDR: case ND_OPT_TARGET_LINKADDR: case ND_OPT_MTU: case ND_OPT_REDIRECTED_HEADER: if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { nd6log((LOG_INFO, "duplicated ND6 option found (type=%d)\n", nd_opt->nd_opt_type)); /* XXX bark? */ } else { ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; } break; case ND_OPT_PREFIX_INFORMATION: if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) { ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; } ndopts->nd_opts_pi_end = (struct nd_opt_prefix_info *)nd_opt; break; default: /* * Unknown options must be silently ignored, * to accomodate future extension to the protocol. */ nd6log((LOG_DEBUG, "nd6_options: unsupported option %d - " "option ignored\n", nd_opt->nd_opt_type)); } skip1: i++; if (i > nd6_maxndopt) { icmp6stat.icp6s_nd_toomanyopt++; nd6log((LOG_INFO, "too many loop in nd opt\n")); break; } if (ndopts->nd_opts_done) break; } return 0; } /* * ND6 timer routine to expire default route list and prefix list */ void nd6_timer(ignored_arg) void *ignored_arg; { int s; struct llinfo_nd6 *ln; struct nd_defrouter *dr; struct nd_prefix *pr; long time_second = time.tv_sec; s = splsoftnet(); callout_reset(&nd6_timer_ch, nd6_prune * hz, nd6_timer, NULL); ln = llinfo_nd6.ln_next; /* XXX BSD/OS separates this code -- itojun */ while (ln && ln != &llinfo_nd6) { struct rtentry *rt; struct ifnet *ifp; struct sockaddr_in6 *dst; struct llinfo_nd6 *next = ln->ln_next; /* XXX: used for the DELAY case only: */ struct nd_ifinfo *ndi = NULL; if ((rt = ln->ln_rt) == NULL) { ln = next; continue; } if ((ifp = rt->rt_ifp) == NULL) { ln = next; continue; } ndi = &nd_ifinfo[ifp->if_index]; dst = (struct sockaddr_in6 *)rt_key(rt); if (ln->ln_expire > time_second) { ln = next; continue; } /* sanity check */ if (!rt) panic("rt=0 in nd6_timer(ln=%p)\n", ln); if (rt->rt_llinfo && (struct llinfo_nd6 *)rt->rt_llinfo != ln) panic("rt_llinfo(%p) is not equal to ln(%p)\n", rt->rt_llinfo, ln); if (!dst) panic("dst=0 in nd6_timer(ln=%p)\n", ln); switch (ln->ln_state) { case ND6_LLINFO_INCOMPLETE: if (ln->ln_asked < nd6_mmaxtries) { ln->ln_asked++; ln->ln_expire = time_second + nd_ifinfo[ifp->if_index].retrans / 1000; nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0); } else { struct mbuf *m = ln->ln_hold; if (m) { if (rt->rt_ifp) { /* * Fake rcvif to make ICMP error * more helpful in diagnosing * for the receiver. * XXX: should we consider * older rcvif? */ m->m_pkthdr.rcvif = rt->rt_ifp; } icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0); ln->ln_hold = NULL; } next = nd6_free(rt); } break; case ND6_LLINFO_REACHABLE: if (ln->ln_expire) { ln->ln_state = ND6_LLINFO_STALE; ln->ln_expire = time_second + nd6_gctimer; } break; case ND6_LLINFO_STALE: /* Garbage Collection(RFC 2461 5.3) */ if (ln->ln_expire) next = nd6_free(rt); break; case ND6_LLINFO_DELAY: if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) { /* We need NUD */ ln->ln_asked = 1; ln->ln_state = ND6_LLINFO_PROBE; ln->ln_expire = time_second + ndi->retrans / 1000; nd6_ns_output(ifp, &dst->sin6_addr, &dst->sin6_addr, ln, 0); } else { ln->ln_state = ND6_LLINFO_STALE; /* XXX */ ln->ln_expire = time_second + nd6_gctimer; } break; case ND6_LLINFO_PROBE: if (ln->ln_asked < nd6_umaxtries) { ln->ln_asked++; ln->ln_expire = time_second + nd_ifinfo[ifp->if_index].retrans / 1000; nd6_ns_output(ifp, &dst->sin6_addr, &dst->sin6_addr, ln, 0); } else next = nd6_free(rt); break; } ln = next; } /* expire default router list */ dr = TAILQ_FIRST(&nd_defrouter); while (dr) { if (dr->expire && dr->expire < time_second) { struct nd_defrouter *t; t = TAILQ_NEXT(dr, dr_entry); defrtrlist_del(dr); dr = t; } else { dr = TAILQ_NEXT(dr, dr_entry); } } pr = nd_prefix.lh_first; while (pr) { struct in6_ifaddr *ia6; struct in6_addrlifetime *lt6; if (IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr)) ia6 = NULL; else ia6 = in6ifa_ifpwithaddr(pr->ndpr_ifp, &pr->ndpr_addr); if (ia6) { /* check address lifetime */ lt6 = &ia6->ia6_lifetime; if (lt6->ia6t_preferred && lt6->ia6t_preferred < time_second) ia6->ia6_flags |= IN6_IFF_DEPRECATED; if (lt6->ia6t_expire && lt6->ia6t_expire < time_second) { if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr)) in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr); /* xxx ND_OPT_PI_FLAG_ONLINK processing */ } } /* * check prefix lifetime. * since pltime is just for autoconf, pltime processing for * prefix is not necessary. * * we offset expire time by NDPR_KEEP_EXPIRE, so that we * can use the old prefix information to validate the * next prefix information to come. See prelist_update() * for actual validation. */ if (pr->ndpr_expire && pr->ndpr_expire + NDPR_KEEP_EXPIRED < time_second) { struct nd_prefix *t; t = pr->ndpr_next; /* * address expiration and prefix expiration are * separate. NEVER perform in6_ifdel here. */ prelist_remove(pr); pr = t; } else pr = pr->ndpr_next; } splx(s); } /* * Nuke neighbor cache/prefix/default router management table, right before * ifp goes away. */ void nd6_purge(ifp) struct ifnet *ifp; { struct llinfo_nd6 *ln, *nln; struct nd_defrouter *dr, *ndr, drany; struct nd_prefix *pr, *npr; /* Nuke default router list entries toward ifp */ if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) { /* * The first entry of the list may be stored in * the routing table, so we'll delete it later. */ for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = ndr) { ndr = TAILQ_NEXT(dr, dr_entry); if (dr->ifp == ifp) defrtrlist_del(dr); } dr = TAILQ_FIRST(&nd_defrouter); if (dr->ifp == ifp) defrtrlist_del(dr); } /* Nuke prefix list entries toward ifp */ for (pr = nd_prefix.lh_first; pr; pr = npr) { npr = pr->ndpr_next; if (pr->ndpr_ifp == ifp) { if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr)) in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr); prelist_remove(pr); } } /* cancel default outgoing interface setting */ if (nd6_defifindex == ifp->if_index) nd6_setdefaultiface(0); if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */ /* refresh default router list */ bzero(&drany, sizeof(drany)); defrouter_delreq(&drany, 0); defrouter_select(); } /* * Nuke neighbor cache entries for the ifp. * Note that rt->rt_ifp may not be the same as ifp, * due to KAME goto ours hack. See RTM_RESOLVE case in * nd6_rtrequest(), and ip6_input(). */ ln = llinfo_nd6.ln_next; while (ln && ln != &llinfo_nd6) { struct rtentry *rt; struct sockaddr_dl *sdl; nln = ln->ln_next; rt = ln->ln_rt; if (rt && rt->rt_gateway && rt->rt_gateway->sa_family == AF_LINK) { sdl = (struct sockaddr_dl *)rt->rt_gateway; if (sdl->sdl_index == ifp->if_index) nln = nd6_free(rt); } ln = nln; } } struct rtentry * nd6_lookup(addr6, create, ifp) struct in6_addr *addr6; int create; struct ifnet *ifp; { struct rtentry *rt; struct sockaddr_in6 sin6; bzero(&sin6, sizeof(sin6)); sin6.sin6_len = sizeof(struct sockaddr_in6); sin6.sin6_family = AF_INET6; sin6.sin6_addr = *addr6; rt = rtalloc1((struct sockaddr *)&sin6, create); if (rt && (rt->rt_flags & RTF_LLINFO) == 0) { /* * This is the case for the default route. * If we want to create a neighbor cache for the address, we * should free the route for the destination and allocate an * interface route. */ if (create) { RTFREE(rt); rt = 0; } } if (!rt) { if (create && ifp) { int e; /* * If no route is available and create is set, * we allocate a host route for the destination * and treat it like an interface route. * This hack is necessary for a neighbor which can't * be covered by our own prefix. */ struct ifaddr *ifa = ifaof_ifpforaddr((struct sockaddr *)&sin6, ifp); if (ifa == NULL) return(NULL); /* * Create a new route. RTF_LLINFO is necessary * to create a Neighbor Cache entry for the * destination in nd6_rtrequest which will be * called in rtequest via ifa->ifa_rtrequest. */ if ((e = rtrequest(RTM_ADD, (struct sockaddr *)&sin6, ifa->ifa_addr, (struct sockaddr *)&all1_sa, (ifa->ifa_flags | RTF_HOST | RTF_LLINFO) & ~RTF_CLONING, &rt)) != 0) log(LOG_ERR, "nd6_lookup: failed to add route for a " "neighbor(%s), errno=%d\n", ip6_sprintf(addr6), e); if (rt == NULL) return(NULL); if (rt->rt_llinfo) { struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; ln->ln_state = ND6_LLINFO_NOSTATE; } } else return(NULL); } rt->rt_refcnt--; /* * Validation for the entry. * XXX: we can't use rt->rt_ifp to check for the interface, since * it might be the loopback interface if the entry is for our * own address on a non-loopback interface. Instead, we should * use rt->rt_ifa->ifa_ifp, which would specify the REAL interface. */ if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 || rt->rt_gateway->sa_family != AF_LINK || (ifp && rt->rt_ifa->ifa_ifp != ifp)) { if (create) { log(LOG_DEBUG, "nd6_lookup: failed to lookup %s (if = %s)\n", ip6_sprintf(addr6), ifp ? if_name(ifp) : "unspec"); /* xxx more logs... kazu */ } return(0); } return(rt); } /* * Detect if a given IPv6 address identifies a neighbor on a given link. * XXX: should take care of the destination of a p2p link? */ int nd6_is_addr_neighbor(addr, ifp) struct sockaddr_in6 *addr; struct ifnet *ifp; { struct ifaddr *ifa; int i; #define IFADDR6(a) ((((struct in6_ifaddr *)(a))->ia_addr).sin6_addr) #define IFMASK6(a) ((((struct in6_ifaddr *)(a))->ia_prefixmask).sin6_addr) /* * A link-local address is always a neighbor. * XXX: we should use the sin6_scope_id field rather than the embedded * interface index. */ if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) && ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index) return(1); /* * If the address matches one of our addresses, * it should be a neighbor. */ for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next) { if (ifa->ifa_addr->sa_family != AF_INET6) next: continue; for (i = 0; i < 4; i++) { if ((IFADDR6(ifa).s6_addr32[i] ^ addr->sin6_addr.s6_addr32[i]) & IFMASK6(ifa).s6_addr32[i]) goto next; } return(1); } /* * Even if the address matches none of our addresses, it might be * in the neighbor cache. */ if (nd6_lookup(&addr->sin6_addr, 0, ifp)) return(1); return(0); #undef IFADDR6 #undef IFMASK6 } /* * Free an nd6 llinfo entry. */ struct llinfo_nd6 * nd6_free(rt) struct rtentry *rt; { struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo, *next; struct in6_addr in6 = ((struct sockaddr_in6 *)rt_key(rt))->sin6_addr; struct nd_defrouter *dr; /* * Clear all destination cache entries for the neighbor. * XXX: is it better to restrict this to hosts? */ pfctlinput(PRC_HOSTDEAD, rt_key(rt)); if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */ int s; s = splsoftnet(); dr = defrouter_lookup(&((struct sockaddr_in6 *)rt_key(rt))->sin6_addr, rt->rt_ifp); if (ln->ln_router || dr) { /* * rt6_flush must be called whether or not the neighbor * is in the Default Router List. * See a corresponding comment in nd6_na_input(). */ rt6_flush(&in6, rt->rt_ifp); } if (dr) { /* * Unreachablity of a router might affect the default * router selection and on-link detection of advertised * prefixes. */ /* * Temporarily fake the state to choose a new default * router and to perform on-link determination of * prefixes coreectly. * Below the state will be set correctly, * or the entry itself will be deleted. */ ln->ln_state = ND6_LLINFO_INCOMPLETE; if (dr == TAILQ_FIRST(&nd_defrouter)) { /* * It is used as the current default router, * so we have to move it to the end of the * list and choose a new one. * XXX: it is not very efficient if this is * the only router. */ TAILQ_REMOVE(&nd_defrouter, dr, dr_entry); TAILQ_INSERT_TAIL(&nd_defrouter, dr, dr_entry); defrouter_select(); } pfxlist_onlink_check(); } splx(s); } /* * Before deleting the entry, remember the next entry as the * return value. We need this because pfxlist_onlink_check() above * might have freed other entries (particularly the old next entry) as * a side effect (XXX). */ next = ln->ln_next; /* * Detach the route from the routing tree and the list of neighbor * caches, and disable the route entry not to be used in already * cached routes. */ rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), 0, (struct rtentry **)0); return(next); } /* * Upper-layer reachability hint for Neighbor Unreachability Detection. * * XXX cost-effective metods? */ void nd6_nud_hint(rt, dst6, force) struct rtentry *rt; struct in6_addr *dst6; int force; { struct llinfo_nd6 *ln; long time_second = time.tv_sec; /* * If the caller specified "rt", use that. Otherwise, resolve the * routing table by supplied "dst6". */ if (!rt) { if (!dst6) return; if (!(rt = nd6_lookup(dst6, 0, NULL))) return; } if ((rt->rt_flags & RTF_GATEWAY) != 0 || (rt->rt_flags & RTF_LLINFO) == 0 || !rt->rt_llinfo || !rt->rt_gateway || rt->rt_gateway->sa_family != AF_LINK) { /* This is not a host route. */ return; } ln = (struct llinfo_nd6 *)rt->rt_llinfo; if (ln->ln_state < ND6_LLINFO_REACHABLE) return; /* * if we get upper-layer reachability confirmation many times, * it is possible we have false information. */ if (!force) { ln->ln_byhint++; if (ln->ln_byhint > nd6_maxnudhint) return; } ln->ln_state = ND6_LLINFO_REACHABLE; if (ln->ln_expire) ln->ln_expire = time_second + nd_ifinfo[rt->rt_ifp->if_index].reachable; } #ifdef OLDIP6OUTPUT /* * Resolve an IP6 address into an ethernet address. If success, * desten is filled in. If there is no entry in ndptab, * set one up and multicast a solicitation for the IP6 address. * Hold onto this mbuf and resend it once the address * is finally resolved. A return value of 1 indicates * that desten has been filled in and the packet should be sent * normally; a 0 return indicates that the packet has been * taken over here, either now or for later transmission. */ int nd6_resolve(ifp, rt, m, dst, desten) struct ifnet *ifp; struct rtentry *rt; struct mbuf *m; struct sockaddr *dst; u_char *desten; { struct llinfo_nd6 *ln = (struct llinfo_nd6 *)NULL; struct sockaddr_dl *sdl; long time_second = time.tv_sec; if (m->m_flags & M_MCAST) { switch (ifp->if_type) { case IFT_ETHER: case IFT_FDDI: ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr, desten); return(1); case IFT_IEEE1394: bcopy(ifp->if_broadcastaddr, desten, ifp->if_addrlen); return(1); case IFT_ARCNET: *desten = 0; return(1); default: m_freem(m); return(0); } } if (rt && (rt->rt_flags & RTF_LLINFO) != 0) ln = (struct llinfo_nd6 *)rt->rt_llinfo; else { if ((rt = nd6_lookup(&(SIN6(dst)->sin6_addr), 1, ifp)) != NULL) ln = (struct llinfo_nd6 *)rt->rt_llinfo; } if (!ln || !rt) { log(LOG_DEBUG, "nd6_resolve: can't allocate llinfo for %s\n", ip6_sprintf(&(SIN6(dst)->sin6_addr))); m_freem(m); return(0); } sdl = SDL(rt->rt_gateway); /* * Ckeck the address family and length is valid, the address * is resolved; otherwise, try to resolve. */ if (ln->ln_state >= ND6_LLINFO_REACHABLE && sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { bcopy(LLADDR(sdl), desten, sdl->sdl_alen); if (ln->ln_state == ND6_LLINFO_STALE) { ln->ln_asked = 0; ln->ln_state = ND6_LLINFO_DELAY; ln->ln_expire = time_second + nd6_delay; } return(1); } /* * There is an ndp entry, but no ethernet address * response yet. Replace the held mbuf with this * latest one. * * XXX Does the code conform to rate-limiting rule? * (RFC 2461 7.2.2) */ if (ln->ln_state == ND6_LLINFO_NOSTATE) ln->ln_state = ND6_LLINFO_INCOMPLETE; if (ln->ln_hold) m_freem(ln->ln_hold); ln->ln_hold = m; if (ln->ln_expire) { if (ln->ln_asked < nd6_mmaxtries && ln->ln_expire < time_second) { ln->ln_asked++; ln->ln_expire = time_second + nd_ifinfo[ifp->if_index].retrans / 1000; nd6_ns_output(ifp, NULL, &(SIN6(dst)->sin6_addr), ln, 0); } } /* do not free mbuf here, it is queued into llinfo_nd6 */ return(0); } #endif /* OLDIP6OUTPUT */ void nd6_rtrequest(req, rt, info) int req; struct rtentry *rt; struct rt_addrinfo *info; /* xxx unused */ { struct sockaddr *gate = rt->rt_gateway; struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK}; struct ifnet *ifp = rt->rt_ifp; struct ifaddr *ifa; long time_second = time.tv_sec; if (rt->rt_flags & RTF_GATEWAY) return; switch (req) { case RTM_ADD: /* * There is no backward compatibility :) * * if ((rt->rt_flags & RTF_HOST) == 0 && * SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) * rt->rt_flags |= RTF_CLONING; */ if (rt->rt_flags & (RTF_CLONING | RTF_LLINFO)) { /* * Case 1: This route should come from * a route to interface. RTF_LLINFO flag is set * for a host route whose destination should be * treated as on-link. */ rt_setgate(rt, rt_key(rt), (struct sockaddr *)&null_sdl); gate = rt->rt_gateway; SDL(gate)->sdl_type = ifp->if_type; SDL(gate)->sdl_index = ifp->if_index; if (ln) ln->ln_expire = time_second; #if 1 if (ln && ln->ln_expire == 0) { /* kludge for desktops */ #if 0 printf("nd6_request: time.tv_sec is zero; " "treat it as 1\n"); #endif ln->ln_expire = 1; } #endif if (rt->rt_flags & RTF_CLONING) break; } /* * In IPv4 code, we try to annonuce new RTF_ANNOUNCE entry here. * We don't do that here since llinfo is not ready yet. * * There are also couple of other things to be discussed: * - unsolicited NA code needs improvement beforehand * - RFC2461 says we MAY send multicast unsolicited NA * (7.2.6 paragraph 4), however, it also says that we * SHOULD provide a mechanism to prevent multicast NA storm. * we don't have anything like it right now. * note that the mechanism needs a mutual agreement * between proxies, which means that we need to implement * a new protocol, or a new kludge. * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA. * we need to check ip6forwarding before sending it. * (or should we allow proxy ND configuration only for * routers? there's no mention about proxy ND from hosts) */ #if 0 /* XXX it does not work */ if (rt->rt_flags & RTF_ANNOUNCE) nd6_na_output(ifp, &SIN6(rt_key(rt))->sin6_addr, &SIN6(rt_key(rt))->sin6_addr, ip6_forwarding ? ND_NA_FLAG_ROUTER : 0, 1, NULL); #endif /* FALLTHROUGH */ case RTM_RESOLVE: if ((ifp->if_flags & IFF_POINTOPOINT) == 0) { /* * Address resolution isn't necessary for a point to * point link, so we can skip this test for a p2p link. */ if (gate->sa_family != AF_LINK || gate->sa_len < sizeof(null_sdl)) { log(LOG_DEBUG, "nd6_rtrequest: bad gateway value: %s\n", if_name(ifp)); break; } SDL(gate)->sdl_type = ifp->if_type; SDL(gate)->sdl_index = ifp->if_index; } if (ln != NULL) break; /* This happens on a route change */ /* * Case 2: This route may come from cloning, or a manual route * add with a LL address. */ R_Malloc(ln, struct llinfo_nd6 *, sizeof(*ln)); rt->rt_llinfo = (caddr_t)ln; if (!ln) { log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n"); break; } nd6_inuse++; nd6_allocated++; Bzero(ln, sizeof(*ln)); ln->ln_rt = rt; /* this is required for "ndp" command. - shin */ if (req == RTM_ADD) { /* * gate should have some valid AF_LINK entry, * and ln->ln_expire should have some lifetime * which is specified by ndp command. */ ln->ln_state = ND6_LLINFO_REACHABLE; ln->ln_byhint = 0; } else { /* * When req == RTM_RESOLVE, rt is created and * initialized in rtrequest(), so rt_expire is 0. */ ln->ln_state = ND6_LLINFO_NOSTATE; ln->ln_expire = time_second; } rt->rt_flags |= RTF_LLINFO; ln->ln_next = llinfo_nd6.ln_next; llinfo_nd6.ln_next = ln; ln->ln_prev = &llinfo_nd6; ln->ln_next->ln_prev = ln; /* * check if rt_key(rt) is one of my address assigned * to the interface. */ ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp, &SIN6(rt_key(rt))->sin6_addr); if (ifa) { caddr_t macp = nd6_ifptomac(ifp); ln->ln_expire = 0; ln->ln_state = ND6_LLINFO_REACHABLE; ln->ln_byhint = 0; if (macp) { Bcopy(macp, LLADDR(SDL(gate)), ifp->if_addrlen); SDL(gate)->sdl_alen = ifp->if_addrlen; } if (nd6_useloopback) { rt->rt_ifp = &loif[0]; /*XXX*/ /* * Make sure rt_ifa be equal to the ifaddr * corresponding to the address. * We need this because when we refer * rt_ifa->ia6_flags in ip6_input, we assume * that the rt_ifa points to the address instead * of the loopback address. */ if (ifa != rt->rt_ifa) { IFAFREE(rt->rt_ifa); IFAREF(ifa); rt->rt_ifa = ifa; } } } else if (rt->rt_flags & RTF_ANNOUNCE) { ln->ln_expire = 0; ln->ln_state = ND6_LLINFO_REACHABLE; ln->ln_byhint = 0; /* join solicited node multicast for proxy ND */ if (ifp->if_flags & IFF_MULTICAST) { struct in6_addr llsol; int error; llsol = SIN6(rt_key(rt))->sin6_addr; llsol.s6_addr16[0] = htons(0xff02); llsol.s6_addr16[1] = htons(ifp->if_index); llsol.s6_addr32[1] = 0; llsol.s6_addr32[2] = htonl(1); llsol.s6_addr8[12] = 0xff; if (!in6_addmulti(&llsol, ifp, &error)) { nd6log((LOG_ERR, "%s: " "failed to join %s (errno=%d)\n", if_name(ifp), ip6_sprintf(&llsol), error)); } } } break; case RTM_DELETE: if (!ln) break; /* leave from solicited node multicast for proxy ND */ if ((rt->rt_flags & RTF_ANNOUNCE) != 0 && (ifp->if_flags & IFF_MULTICAST) != 0) { struct in6_addr llsol; struct in6_multi *in6m; llsol = SIN6(rt_key(rt))->sin6_addr; llsol.s6_addr16[0] = htons(0xff02); llsol.s6_addr16[1] = htons(ifp->if_index); llsol.s6_addr32[1] = 0; llsol.s6_addr32[2] = htonl(1); llsol.s6_addr8[12] = 0xff; IN6_LOOKUP_MULTI(llsol, ifp, in6m); if (in6m) in6_delmulti(in6m); } nd6_inuse--; ln->ln_next->ln_prev = ln->ln_prev; ln->ln_prev->ln_next = ln->ln_next; ln->ln_prev = NULL; rt->rt_llinfo = 0; rt->rt_flags &= ~RTF_LLINFO; if (ln->ln_hold) m_freem(ln->ln_hold); Free((caddr_t)ln); } } void nd6_p2p_rtrequest(req, rt, info) int req; struct rtentry *rt; struct rt_addrinfo *info; /* xxx unused */ { struct sockaddr *gate = rt->rt_gateway; static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK}; struct ifnet *ifp = rt->rt_ifp; struct ifaddr *ifa; if (rt->rt_flags & RTF_GATEWAY) return; switch (req) { case RTM_ADD: /* * There is no backward compatibility :) * * if ((rt->rt_flags & RTF_HOST) == 0 && * SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) * rt->rt_flags |= RTF_CLONING; */ if (rt->rt_flags & RTF_CLONING) { /* * Case 1: This route should come from * a route to interface. */ rt_setgate(rt, rt_key(rt), (struct sockaddr *)&null_sdl); gate = rt->rt_gateway; SDL(gate)->sdl_type = ifp->if_type; SDL(gate)->sdl_index = ifp->if_index; break; } /* Announce a new entry if requested. */ if (rt->rt_flags & RTF_ANNOUNCE) nd6_na_output(ifp, &SIN6(rt_key(rt))->sin6_addr, &SIN6(rt_key(rt))->sin6_addr, ip6_forwarding ? ND_NA_FLAG_ROUTER : 0, 1, NULL); /* FALLTHROUGH */ case RTM_RESOLVE: /* * check if rt_key(rt) is one of my address assigned * to the interface. */ ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp, &SIN6(rt_key(rt))->sin6_addr); if (ifa) { if (nd6_useloopback) { rt->rt_ifp = &loif[0]; /*XXX*/ } } break; } } int nd6_ioctl(cmd, data, ifp) u_long cmd; caddr_t data; struct ifnet *ifp; { struct in6_drlist *drl = (struct in6_drlist *)data; struct in6_prlist *prl = (struct in6_prlist *)data; struct in6_ndireq *ndi = (struct in6_ndireq *)data; struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data; struct in6_ndifreq *ndif = (struct in6_ndifreq *)data; struct nd_defrouter *dr, any; struct nd_prefix *pr; struct rtentry *rt; int i = 0, error = 0; int s; switch (cmd) { case SIOCGDRLST_IN6: bzero(drl, sizeof(*drl)); s = splsoftnet(); dr = TAILQ_FIRST(&nd_defrouter); while (dr && i < DRLSTSIZ) { drl->defrouter[i].rtaddr = dr->rtaddr; if (IN6_IS_ADDR_LINKLOCAL(&drl->defrouter[i].rtaddr)) { /* XXX: need to this hack for KAME stack */ drl->defrouter[i].rtaddr.s6_addr16[1] = 0; } else log(LOG_ERR, "default router list contains a " "non-linklocal address(%s)\n", ip6_sprintf(&drl->defrouter[i].rtaddr)); drl->defrouter[i].flags = dr->flags; drl->defrouter[i].rtlifetime = dr->rtlifetime; drl->defrouter[i].expire = dr->expire; drl->defrouter[i].if_index = dr->ifp->if_index; i++; dr = TAILQ_NEXT(dr, dr_entry); } splx(s); break; case SIOCGPRLST_IN6: /* * XXX meaning of fields, especialy "raflags", is very * differnet between RA prefix list and RR/static prefix list. * how about separating ioctls into two? */ bzero(prl, sizeof(*prl)); s = splsoftnet(); pr = nd_prefix.lh_first; while (pr && i < PRLSTSIZ) { struct nd_pfxrouter *pfr; int j; prl->prefix[i].prefix = pr->ndpr_prefix.sin6_addr; prl->prefix[i].raflags = pr->ndpr_raf; prl->prefix[i].prefixlen = pr->ndpr_plen; prl->prefix[i].vltime = pr->ndpr_vltime; prl->prefix[i].pltime = pr->ndpr_pltime; prl->prefix[i].if_index = pr->ndpr_ifp->if_index; prl->prefix[i].expire = pr->ndpr_expire; pfr = pr->ndpr_advrtrs.lh_first; j = 0; while (pfr) { if (j < DRLSTSIZ) { #define RTRADDR prl->prefix[i].advrtr[j] RTRADDR = pfr->router->rtaddr; if (IN6_IS_ADDR_LINKLOCAL(&RTRADDR)) { /* XXX: hack for KAME */ RTRADDR.s6_addr16[1] = 0; } else log(LOG_ERR, "a router(%s) advertises " "a prefix with " "non-link local address\n", ip6_sprintf(&RTRADDR)); #undef RTRADDR } j++; pfr = pfr->pfr_next; } prl->prefix[i].advrtrs = j; prl->prefix[i].origin = PR_ORIG_RA; i++; pr = pr->ndpr_next; } { struct rr_prefix *rpp; for (rpp = LIST_FIRST(&rr_prefix); rpp; rpp = LIST_NEXT(rpp, rp_entry)) { if (i >= PRLSTSIZ) break; prl->prefix[i].prefix = rpp->rp_prefix.sin6_addr; prl->prefix[i].raflags = rpp->rp_raf; prl->prefix[i].prefixlen = rpp->rp_plen; prl->prefix[i].vltime = rpp->rp_vltime; prl->prefix[i].pltime = rpp->rp_pltime; prl->prefix[i].if_index = rpp->rp_ifp->if_index; prl->prefix[i].expire = rpp->rp_expire; prl->prefix[i].advrtrs = 0; prl->prefix[i].origin = rpp->rp_origin; i++; } } splx(s); break; case SIOCGIFINFO_IN6: if (!nd_ifinfo || i >= nd_ifinfo_indexlim) { error = EINVAL; break; } ndi->ndi = nd_ifinfo[ifp->if_index]; break; case SIOCSIFINFO_FLAGS: /* XXX: almost all other fields of ndi->ndi is unused */ if (!nd_ifinfo || i >= nd_ifinfo_indexlim) { error = EINVAL; break; } nd_ifinfo[ifp->if_index].flags = ndi->ndi.flags; break; case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */ /* flush default router list */ /* * xxx sumikawa: should not delete route if default * route equals to the top of default router list */ bzero(&any, sizeof(any)); defrouter_delreq(&any, 0); defrouter_select(); /* xxx sumikawa: flush prefix list */ break; case SIOCSPFXFLUSH_IN6: { /* flush all the prefix advertised by routers */ struct nd_prefix *pr, *next; s = splsoftnet(); for (pr = nd_prefix.lh_first; pr; pr = next) { next = pr->ndpr_next; if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr)) in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr); prelist_remove(pr); } splx(s); break; } case SIOCSRTRFLUSH_IN6: { /* flush all the default routers */ struct nd_defrouter *dr, *next; s = splsoftnet(); if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) { /* * The first entry of the list may be stored in * the routing table, so we'll delete it later. */ for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = next) { next = TAILQ_NEXT(dr, dr_entry); defrtrlist_del(dr); } defrtrlist_del(TAILQ_FIRST(&nd_defrouter)); } splx(s); break; } case SIOCGNBRINFO_IN6: { struct llinfo_nd6 *ln; struct in6_addr nb_addr = nbi->addr; /* make local for safety */ /* * XXX: KAME specific hack for scoped addresses * XXXX: for other scopes than link-local? */ if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) || IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) { u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2]; if (*idp == 0) *idp = htons(ifp->if_index); } s = splsoftnet(); if ((rt = nd6_lookup(&nb_addr, 0, ifp)) == NULL) { error = EINVAL; splx(s); break; } ln = (struct llinfo_nd6 *)rt->rt_llinfo; nbi->state = ln->ln_state; nbi->asked = ln->ln_asked; nbi->isrouter = ln->ln_router; nbi->expire = ln->ln_expire; splx(s); break; } case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */ ndif->ifindex = nd6_defifindex; break; case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */ return(nd6_setdefaultiface(ndif->ifindex)); break; } return(error); } /* * Create neighbor cache entry and cache link-layer address, * on reception of inbound ND6 packets. (RS/RA/NS/redirect) */ struct rtentry * nd6_cache_lladdr(ifp, from, lladdr, lladdrlen, type, code) struct ifnet *ifp; struct in6_addr *from; char *lladdr; int lladdrlen; int type; /* ICMP6 type */ int code; /* type dependent information */ { struct rtentry *rt = NULL; struct llinfo_nd6 *ln = NULL; int is_newentry; struct sockaddr_dl *sdl = NULL; int do_update; int olladdr; int llchange; int newstate = 0; long time_second = time.tv_sec; if (!ifp) panic("ifp == NULL in nd6_cache_lladdr"); if (!from) panic("from == NULL in nd6_cache_lladdr"); /* nothing must be updated for unspecified address */ if (IN6_IS_ADDR_UNSPECIFIED(from)) return NULL; /* * Validation about ifp->if_addrlen and lladdrlen must be done in * the caller. * * XXX If the link does not have link-layer adderss, what should * we do? (ifp->if_addrlen == 0) * Spec says nothing in sections for RA, RS and NA. There's small * description on it in NS section (RFC 2461 7.2.3). */ rt = nd6_lookup(from, 0, ifp); if (!rt) { #if 0 /* nothing must be done if there's no lladdr */ if (!lladdr || !lladdrlen) return NULL; #endif rt = nd6_lookup(from, 1, ifp); is_newentry = 1; } else { /* do nothing if static ndp is set */ if (rt->rt_flags & RTF_STATIC) return NULL; is_newentry = 0; } if (!rt) return NULL; if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) { fail: (void)nd6_free(rt); return NULL; } ln = (struct llinfo_nd6 *)rt->rt_llinfo; if (!ln) goto fail; if (!rt->rt_gateway) goto fail; if (rt->rt_gateway->sa_family != AF_LINK) goto fail; sdl = SDL(rt->rt_gateway); olladdr = (sdl->sdl_alen) ? 1 : 0; if (olladdr && lladdr) { if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) llchange = 1; else llchange = 0; } else llchange = 0; /* * newentry olladdr lladdr llchange (*=record) * 0 n n -- (1) * 0 y n -- (2) * 0 n y -- (3) * STALE * 0 y y n (4) * * 0 y y y (5) * STALE * 1 -- n -- (6) NOSTATE(= PASSIVE) * 1 -- y -- (7) * STALE */ if (lladdr) { /*(3-5) and (7)*/ /* * Record source link-layer address * XXX is it dependent to ifp->if_type? */ sdl->sdl_alen = ifp->if_addrlen; bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); } if (!is_newentry) { if ((!olladdr && lladdr) /*(3)*/ || (olladdr && lladdr && llchange)) { /*(5)*/ do_update = 1; newstate = ND6_LLINFO_STALE; } else /*(1-2,4)*/ do_update = 0; } else { do_update = 1; if (!lladdr) /*(6)*/ newstate = ND6_LLINFO_NOSTATE; else /*(7)*/ newstate = ND6_LLINFO_STALE; } if (do_update) { /* * Update the state of the neighbor cache. */ ln->ln_state = newstate; if (ln->ln_state == ND6_LLINFO_STALE) { /* * XXX: since nd6_output() below will cause * state tansition to DELAY and reset the timer, * we must set the timer now, although it is actually * meaningless. */ ln->ln_expire = time_second + nd6_gctimer; if (ln->ln_hold) { #ifdef OLDIP6OUTPUT ln->ln_asked = 0; ln->ln_state = ND6_LLINFO_DELAY; ln->ln_expire = time_second + nd6_delay; (*ifp->if_output)(ifp, ln->ln_hold, rt_key(rt), rt); #else /* * we assume ifp is not a p2p here, so just * set the 2nd argument as the 1st one. */ nd6_output(ifp, ifp, ln->ln_hold, (struct sockaddr_in6 *)rt_key(rt), rt); #endif ln->ln_hold = NULL; } } else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { /* probe right away */ ln->ln_expire = time_second; } } /* * ICMP6 type dependent behavior. * * NS: clear IsRouter if new entry * RS: clear IsRouter * RA: set IsRouter if there's lladdr * redir: clear IsRouter if new entry * * RA case, (1): * The spec says that we must set IsRouter in the following cases: * - If lladdr exist, set IsRouter. This means (1-5). * - If it is old entry (!newentry), set IsRouter. This means (7). * So, based on the spec, in (1-5) and (7) cases we must set IsRouter. * A quetion arises for (1) case. (1) case has no lladdr in the * neighbor cache, this is similar to (6). * This case is rare but we figured that we MUST NOT set IsRouter. * * newentry olladdr lladdr llchange NS RS RA redir * D R * 0 n n -- (1) c ? s * 0 y n -- (2) c s s * 0 n y -- (3) c s s * 0 y y n (4) c s s * 0 y y y (5) c s s * 1 -- n -- (6) c c c s * 1 -- y -- (7) c c s c s * * (c=clear s=set) */ switch (type & 0xff) { case ND_NEIGHBOR_SOLICIT: /* * New entry must have is_router flag cleared. */ if (is_newentry) /*(6-7)*/ ln->ln_router = 0; break; case ND_REDIRECT: /* * If the icmp is a redirect to a better router, always set the * is_router flag. Otherwise, if the entry is newly created, * clear the flag. [RFC 2461, sec 8.3] */ if (code == ND_REDIRECT_ROUTER) ln->ln_router = 1; else if (is_newentry) /*(6-7)*/ ln->ln_router = 0; break; case ND_ROUTER_SOLICIT: /* * is_router flag must always be cleared. */ ln->ln_router = 0; break; case ND_ROUTER_ADVERT: /* * Mark an entry with lladdr as a router. */ if ((!is_newentry && (olladdr || lladdr)) /*(2-5)*/ || (is_newentry && lladdr)) { /*(7)*/ ln->ln_router = 1; } break; } /* * When the link-layer address of a router changes, select the * best router again. In particular, when the neighbor entry is newly * created, it might affect the selection policy. * Question: can we restrict the first condition to the "is_newentry" * case? * XXX: when we hear an RA from a new router with the link-layer * address option, defrouter_select() is called twice, since * defrtrlist_update called the function as well. However, I believe * we can compromise the overhead, since it only happens the first * time. */ if (do_update && ln->ln_router) defrouter_select(); return rt; } static void nd6_slowtimo(ignored_arg) void *ignored_arg; { int s = splsoftnet(); int i; struct nd_ifinfo *nd6if; callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz, nd6_slowtimo, NULL); for (i = 1; i < if_index + 1; i++) { if (!nd_ifinfo || i >= nd_ifinfo_indexlim) continue; nd6if = &nd_ifinfo[i]; if (nd6if->basereachable && /* already initialized */ (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) { /* * Since reachable time rarely changes by router * advertisements, we SHOULD insure that a new random * value gets recomputed at least once every few hours. * (RFC 2461, 6.3.4) */ nd6if->recalctm = nd6_recalc_reachtm_interval; nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable); } } splx(s); } #define senderr(e) { error = (e); goto bad;} int nd6_output(ifp, origifp, m0, dst, rt0) struct ifnet *ifp; struct ifnet *origifp; struct mbuf *m0; struct sockaddr_in6 *dst; struct rtentry *rt0; { struct mbuf *m = m0; struct rtentry *rt = rt0; struct sockaddr_in6 *gw6 = NULL; struct llinfo_nd6 *ln = NULL; int error = 0; long time_second = time.tv_sec; if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr)) goto sendpkt; /* * XXX: we currently do not make neighbor cache on any interface * other than ARCnet, Ethernet, FDDI and GIF. * * RFC2893 says: * - unidirectional tunnels needs no ND */ switch (ifp->if_type) { case IFT_ARCNET: case IFT_ETHER: case IFT_FDDI: case IFT_IEEE1394: case IFT_GIF: /* XXX need more cases? */ break; default: goto sendpkt; } /* * next hop determination. This routine is derived from ether_outpout. */ if (rt) { if ((rt->rt_flags & RTF_UP) == 0) { if ((rt0 = rt = rtalloc1((struct sockaddr *)dst, 1)) != NULL) { rt->rt_refcnt--; if (rt->rt_ifp != ifp) { /* XXX: loop care? */ return nd6_output(ifp, origifp, m0, dst, rt); } } else senderr(EHOSTUNREACH); } if (rt->rt_flags & RTF_GATEWAY) { gw6 = (struct sockaddr_in6 *)rt->rt_gateway; /* * We skip link-layer address resolution and NUD * if the gateway is not a neighbor from ND point * of view, regardless the value of the * nd_ifinfo.flags. * The second condition is a bit tricky: we skip * if the gateway is our own address, which is * sometimes used to install a route to a p2p link. */ if (!nd6_is_addr_neighbor(gw6, ifp) || in6ifa_ifpwithaddr(ifp, &gw6->sin6_addr)) { /* * We allow this kind of tricky route only * when the outgoing interface is p2p. * XXX: we may need a more generic rule here. */ if ((ifp->if_flags & IFF_POINTOPOINT) == 0) senderr(EHOSTUNREACH); goto sendpkt; } if (rt->rt_gwroute == 0) goto lookup; if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) { rtfree(rt); rt = rt0; lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1); if ((rt = rt->rt_gwroute) == 0) senderr(EHOSTUNREACH); } } } /* * Address resolution or Neighbor Unreachability Detection * for the next hop. * At this point, the destination of the packet must be a unicast * or an anycast address(i.e. not a multicast). */ /* Look up the neighbor cache for the nexthop */ if (rt && (rt->rt_flags & RTF_LLINFO) != 0) ln = (struct llinfo_nd6 *)rt->rt_llinfo; else { /* * Since nd6_is_addr_neighbor() internally calls nd6_lookup(), * the condition below is not very efficient. But we believe * it is tolerable, because this should be a rare case. */ if (nd6_is_addr_neighbor(dst, ifp) && (rt = nd6_lookup(&dst->sin6_addr, 1, ifp)) != NULL) ln = (struct llinfo_nd6 *)rt->rt_llinfo; } if (!ln || !rt) { if ((ifp->if_flags & IFF_POINTOPOINT) == 0 && !(nd_ifinfo[ifp->if_index].flags & ND6_IFF_PERFORMNUD)) { log(LOG_DEBUG, "nd6_output: can't allocate llinfo for %s " "(ln=%p, rt=%p)\n", ip6_sprintf(&dst->sin6_addr), ln, rt); senderr(EIO); /* XXX: good error? */ } goto sendpkt; /* send anyway */ } /* We don't have to do link-layer address resolution on a p2p link. */ if ((ifp->if_flags & IFF_POINTOPOINT) != 0 && ln->ln_state < ND6_LLINFO_REACHABLE) { ln->ln_state = ND6_LLINFO_STALE; ln->ln_expire = time_second + nd6_gctimer; } /* * The first time we send a packet to a neighbor whose entry is * STALE, we have to change the state to DELAY and a sets a timer to * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do * neighbor unreachability detection on expiration. * (RFC 2461 7.3.3) */ if (ln->ln_state == ND6_LLINFO_STALE) { ln->ln_asked = 0; ln->ln_state = ND6_LLINFO_DELAY; ln->ln_expire = time_second + nd6_delay; } /* * If the neighbor cache entry has a state other than INCOMPLETE * (i.e. its link-layer address is already reloved), just * send the packet. */ if (ln->ln_state > ND6_LLINFO_INCOMPLETE) goto sendpkt; /* * There is a neighbor cache entry, but no ethernet address * response yet. Replace the held mbuf (if any) with this * latest one. * * XXX Does the code conform to rate-limiting rule? * (RFC 2461 7.2.2) */ if (ln->ln_state == ND6_LLINFO_NOSTATE) ln->ln_state = ND6_LLINFO_INCOMPLETE; if (ln->ln_hold) m_freem(ln->ln_hold); ln->ln_hold = m; if (ln->ln_expire) { if (ln->ln_asked < nd6_mmaxtries && ln->ln_expire < time_second) { ln->ln_asked++; ln->ln_expire = time_second + nd_ifinfo[ifp->if_index].retrans / 1000; nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0); } } return(0); sendpkt: if ((ifp->if_flags & IFF_LOOPBACK) != 0) { return((*ifp->if_output)(origifp, m, (struct sockaddr *)dst, rt)); } return((*ifp->if_output)(ifp, m, (struct sockaddr *)dst, rt)); bad: if (m) m_freem(m); return (error); } #undef senderr int nd6_storelladdr(ifp, rt, m, dst, desten) struct ifnet *ifp; struct rtentry *rt; struct mbuf *m; struct sockaddr *dst; u_char *desten; { struct sockaddr_dl *sdl; if (m->m_flags & M_MCAST) { switch (ifp->if_type) { case IFT_ETHER: case IFT_FDDI: ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr, desten); return(1); case IFT_IEEE1394: bcopy(ifp->if_broadcastaddr, desten, ifp->if_addrlen); return(1); case IFT_ARCNET: *desten = 0; return(1); default: m_freem(m); return(0); } } if (rt == NULL) { /* this could happen, if we could not allocate memory */ m_freem(m); return(0); } if (rt->rt_gateway->sa_family != AF_LINK) { printf("nd6_storelladdr: something odd happens\n"); m_freem(m); return(0); } sdl = SDL(rt->rt_gateway); if (sdl->sdl_alen == 0) { /* this should be impossible, but we bark here for debugging */ printf("nd6_storelladdr: sdl_alen == 0\n"); m_freem(m); return(0); } bcopy(LLADDR(sdl), desten, sdl->sdl_alen); return(1); }