On 15/08/16(Mon) 13:52, Martin Pieuchot wrote:
> On 11/08/16(Thu) 16:04, Martin Pieuchot wrote:
> > One of the remaining SMP issue with our routing table usage is to
> > guarantee that the L2 entry referenced by a RTF_GATEWAY route via
> > the ``rt_gwroute'' pointer wont be replaced/invalidated by another
> > CPU while we are filling the address field of an Ethernet frame.
> >
> > The most efficient way, performance wise, to do that is to make the
> > ``rt_gwroute'' pointer immutable during the lifetime of a RTF_GATEWAY
> > route. If we know that this pointer won't change and that the memory
> > it points to won't be freed as long as a CPU has reference to one of
> > the RTF_GATEWAY routes, we don't need any special protection inside
> > arp_resolve() and nd6_resolve().
> >
> > Diff below achieve that by always resolving the next-hop entry before
> > inserting the corresponding RTF_GATEWAY route in the tree. In other
> > words rt_setgwroute() is no longer called in the sending path.
> >
> > To guarantee that a cached route won't be deleted while it is still
> > referenced a new flag, RTF_CACHED, is added to the route. arp(8) and
> > ndp(8) treat entry with this flag like RTF_LOCAL.
> >
> > Removing rt_setgwroute() from the sending path means that inserting a
> > RTF_GATEWAY route will now fail if the next-hop cannot be resolve. This
> > might introduce regression for some setups but I see that has an
> > improvement since the kernel no longer let you add a route that cannot
> > be used.
> > It also mean that stale routes need to be fixed whenever a new address
> > is configured. The diff does that and also plug an ifa leak that was
> > happening when the same address is configured twice on an ifa.
> >
> > Note that even with this diff there are *still* some MP-safeness issue
> > due to stale routes, they will be address in a later diff.
>
> Updated diff that:
>
> - Fix a panic reported by Hrvoje Popovski
>
> - Properly invalidate ARP/NDP entry when issuing a RTM_DELETE from
> userland, as discussed with bluhm@. For that I introduced
> RTM_INVALIDATE and use it instead of deleting L2 entries. With
> this we no longer generate deletion/insertion for L2 entries, of
> course that include RTF_CACHED.
>
> - This has been tested with a pppoe(4) setup to make sure that
> inserting a route with a magic 0.0.0.1 gateway works, pointed out
> by claudio@.
>
> More tests, comments, ok are welcome.
Guys I'd rather move forward with that before g2k16, so comments are
welcome such that I can split the diff and commit it.
If people really have good arguments for using locks/SRPs in the hot
in order to keep the existing behavior I'd like to hear them.
> Index: net/route.c
> ===================================================================
> RCS file: /cvs/src/sys/net/route.c,v
> retrieving revision 1.313
> diff -u -p -r1.313 route.c
> --- net/route.c 22 Jul 2016 11:03:30 -0000 1.313
> +++ net/route.c 15 Aug 2016 08:58:39 -0000
> @@ -153,7 +153,9 @@ struct pool rtentry_pool; /* pool for r
> struct pool rttimer_pool; /* pool for rttimer structures */
>
> void rt_timer_init(void);
> -void rt_setgwroute(struct rtentry *, u_int);
> +int rt_setgwroute(struct rtentry *, u_int);
> +void rt_putgwroute(struct rtentry *);
> +int rt_fixgwroute(struct rtentry *, void *, unsigned int);
> int rtflushclone1(struct rtentry *, void *, u_int);
> void rtflushclone(unsigned int, struct rtentry *);
> int rt_if_remove_rtdelete(struct rtentry *, void *, u_int);
> @@ -204,21 +206,20 @@ rtisvalid(struct rtentry *rt)
> if (rt == NULL)
> return (0);
>
> -#ifdef DIAGNOSTIC
> - if (ISSET(rt->rt_flags, RTF_GATEWAY) && (rt->rt_gwroute != NULL) &&
> - ISSET(rt->rt_gwroute->rt_flags, RTF_GATEWAY))
> - panic("next hop must be directly reachable");
> -#endif
> -
> - if ((rt->rt_flags & RTF_UP) == 0)
> + if (!ISSET(rt->rt_flags, RTF_UP))
> return (0);
>
> /* Routes attached to stale ifas should be freed. */
> if (rt->rt_ifa == NULL || rt->rt_ifa->ifa_ifp == NULL)
> return (0);
>
> - if (ISSET(rt->rt_flags, RTF_GATEWAY) && !rtisvalid(rt->rt_gwroute))
> - return (0);
> +#ifdef DIAGNOSTIC
> + if (ISSET(rt->rt_flags, RTF_GATEWAY)) {
> + KASSERT(rt->rt_gwroute != NULL);
> + KASSERT(ISSET(rt->rt_gwroute->rt_flags, RTF_UP));
> + KASSERT(!ISSET(rt->rt_gwroute->rt_flags, RTF_GATEWAY));
> + }
> +#endif /* DIAGNOSTIC */
>
> return (1);
> }
> @@ -267,8 +268,6 @@ rt_match(struct sockaddr *dst, uint32_t
> return (rt);
> }
>
> -struct rtentry *_rtalloc(struct sockaddr *, uint32_t *, int, unsigned int);
> -
> #ifndef SMALL_KERNEL
> /*
> * Originated from bridge_hash() in if_bridge.c
> @@ -349,16 +348,10 @@ rt_hash(struct rtentry *rt, struct socka
> struct rtentry *
> rtalloc_mpath(struct sockaddr *dst, uint32_t *src, unsigned int rtableid)
> {
> - return (_rtalloc(dst, src, RT_RESOLVE, rtableid));
> + return (rt_match(dst, src, RT_RESOLVE, rtableid));
> }
> #endif /* SMALL_KERNEL */
>
> -struct rtentry *
> -rtalloc(struct sockaddr *dst, int flags, unsigned int rtableid)
> -{
> - return (_rtalloc(dst, NULL, flags, rtableid));
> -}
> -
> /*
> * Look in the routing table for the best matching entry for
> * ``dst''.
> @@ -367,44 +360,35 @@ rtalloc(struct sockaddr *dst, int flags,
> * longer valid, try to cache it.
> */
> struct rtentry *
> -_rtalloc(struct sockaddr *dst, uint32_t *src, int flags, unsigned int
> rtableid)
> +rtalloc(struct sockaddr *dst, int flags, unsigned int rtableid)
> {
> - struct rtentry *rt;
> -
> - rt = rt_match(dst, src, flags, rtableid);
> -
> - /* No match or route to host? We're done. */
> - if (rt == NULL || !ISSET(rt->rt_flags, RTF_GATEWAY))
> - return (rt);
> -
> - /* Nothing to do if the next hop is valid. */
> - if (rtisvalid(rt->rt_gwroute))
> - return (rt);
> -
> - rt_setgwroute(rt, rtableid);
> -
> - return (rt);
> + return (rt_match(dst, NULL, flags, rtableid));
> }
>
> -void
> +/*
> + * Cache the route entry corresponding to a reachable next hop in
> + * the gateway entry ``rt''.
> + */
> +int
> rt_setgwroute(struct rtentry *rt, u_int rtableid)
> {
> struct rtentry *nhrt;
>
> - rtfree(rt->rt_gwroute);
> - rt->rt_gwroute = NULL;
> + KERNEL_ASSERT_LOCKED();
>
> - /*
> - * If we cannot find a valid next hop, return the route
> - * with a gateway.
> - *
> - * XXX Some dragons hiding in the tree certainly depends on
> - * this behavior. But it is safe since rt_checkgate() wont
> - * allow us to us this route later on.
> - */
> + KASSERT(ISSET(rt->rt_flags, RTF_GATEWAY));
> + KASSERT(rt->rt_gwroute == NULL);
> +
> + /* If we cannot find a valid next hop bail. */
> nhrt = rt_match(rt->rt_gateway, NULL, RT_RESOLVE, rtable_l2(rtableid));
> if (nhrt == NULL)
> - return;
> + return (ENOENT);
> +
> + /* Next hop entry must be on the same interface. */
> + if (nhrt->rt_ifidx != rt->rt_ifidx) {
> + rtfree(nhrt);
> + return (EHOSTUNREACH);
> + }
>
> /*
> * Next hop must be reachable, this also prevents rtentry
> @@ -412,13 +396,7 @@ rt_setgwroute(struct rtentry *rt, u_int
> */
> if (ISSET(nhrt->rt_flags, RTF_CLONING|RTF_GATEWAY)) {
> rtfree(nhrt);
> - return;
> - }
> -
> - /* Next hop entry must be UP and on the same interface. */
> - if (!ISSET(nhrt->rt_flags, RTF_UP) || nhrt->rt_ifidx != rt->rt_ifidx) {
> - rtfree(nhrt);
> - return;
> + return (ELOOP);
> }
>
> /*
> @@ -429,10 +407,75 @@ rt_setgwroute(struct rtentry *rt, u_int
> rt->rt_mtu = nhrt->rt_mtu;
>
> /*
> - * Do not return the cached next-hop route, rt_checkgate() will
> - * do the magic for us.
> + * To avoid reference counting problems when writting link-layer
> + * addresses in an outgoing packet, we ensure that the lifetime
> + * of a cached entry is greater that the bigger lifetime of the
> + * gateway entries it is pointed by.
> */
> + nhrt->rt_flags |= RTF_CACHED;
> + nhrt->rt_cachecnt++;
> +
> rt->rt_gwroute = nhrt;
> +
> + return (0);
> +}
> +
> +/*
> + * Invalidate the cached route entry of the gateway entry ``rt''.
> + */
> +void
> +rt_putgwroute(struct rtentry *rt)
> +{
> + struct rtentry *nhrt = rt->rt_gwroute;
> +
> + KERNEL_ASSERT_LOCKED();
> +
> + if (!ISSET(rt->rt_flags, RTF_GATEWAY) || nhrt == NULL)
> + return;
> +
> + KASSERT(nhrt->rt_cachecnt > 0);
> +
> + --nhrt->rt_cachecnt;
> + if (nhrt->rt_cachecnt == 0)
> + nhrt->rt_flags &= ~RTF_CACHED;
> +
> + rtfree(rt->rt_gwroute);
> + rt->rt_gwroute = NULL;
> +}
> +
> +/*
> + * Refresh cached entries of RTF_GATEWAY routes for a given interface.
> + *
> + * This clever logic is necessary to try to fix routes linked to stale
> + * ifas.
> + */
> +int
> +rt_fixgwroute(struct rtentry *rt, void *arg, unsigned int id)
> +{
> + struct ifnet *ifp = arg;
> +
> + KERNEL_ASSERT_LOCKED();
> +
> + if (rt->rt_ifidx != ifp->if_index || !ISSET(rt->rt_flags, RTF_GATEWAY))
> + return (0);
> +
> + /*
> + * If the gateway route is not stale, its associated cached
> + * is also not stale.
> + */
> + if (rt->rt_ifa->ifa_ifp != NULL)
> + return (0);
> +
> + /* If we can fix the cached next hop entry, we can fix the ifa. */
> + if (rt_setgate(rt, rt->rt_gateway, ifp->if_rdomain) == 0) {
> + struct ifaddr *ifa = rt->rt_gwroute->rt_ifa;
> +
> + ifafree(rt->rt_ifa);
> + ifa->ifa_refcnt++;
> + rt->rt_ifa = ifa;
> + }
> +
> + return (0);
> }
>
> void
> @@ -889,8 +932,7 @@ rtrequest_delete(struct rt_addrinfo *inf
> if ((rt->rt_flags & RTF_CLONING) != 0)
> rtflushclone(tableid, rt);
>
> - rtfree(rt->rt_gwroute);
> - rt->rt_gwroute = NULL;
> + rt_putgwroute(rt);
>
> rtfree(rt->rt_parent);
> rt->rt_parent = NULL;
> @@ -1099,7 +1141,7 @@ rtrequest(int req, struct rt_addrinfo *i
> tableid))) {
> ifafree(ifa);
> rtfree(rt->rt_parent);
> - rtfree(rt->rt_gwroute);
> + rt_putgwroute(rt);
> free(rt->rt_gateway, M_RTABLE, 0);
> free(ndst, M_RTABLE, dlen);
> pool_put(&rtentry_pool, rt);
> @@ -1129,7 +1171,7 @@ rtrequest(int req, struct rt_addrinfo *i
> if (error != 0) {
> ifafree(ifa);
> rtfree(rt->rt_parent);
> - rtfree(rt->rt_gwroute);
> + rt_putgwroute(rt);
> free(rt->rt_gateway, M_RTABLE, 0);
> free(ndst, M_RTABLE, dlen);
> pool_put(&rtentry_pool, rt);
> @@ -1170,33 +1212,27 @@ rt_setgate(struct rtentry *rt, struct so
> }
> memmove(rt->rt_gateway, gate, glen);
>
> - if (ISSET(rt->rt_flags, RTF_GATEWAY))
> - rt_setgwroute(rt, rtableid);
> + if (ISSET(rt->rt_flags, RTF_GATEWAY)) {
> + rt_putgwroute(rt);
> + return (rt_setgwroute(rt, rtableid));
> + }
>
> return (0);
> }
>
> -int
> -rt_checkgate(struct rtentry *rt, struct rtentry **rtp)
> +/*
> + * Return the route entry containing the next hop link-layer
> + * address corresponding to ``rt''.
> + */
> +struct rtentry *
> +rt_getll(struct rtentry *rt)
> {
> - struct rtentry *rt0;
> -
> - KASSERT(rt != NULL);
> -
> - rt0 = rt;
> -
> - if (rt->rt_flags & RTF_GATEWAY) {
> - if (rt->rt_gwroute == NULL)
> - return (EHOSTUNREACH);
> - rt = rt->rt_gwroute;
> + if (ISSET(rt->rt_flags, RTF_GATEWAY)) {
> + KASSERT(rt->rt_gwroute != NULL);
> + return (rt->rt_gwroute);
> }
>
> - if (rt->rt_flags & RTF_REJECT)
> - if (rt->rt_expire == 0 || time_uptime < rt->rt_expire)
> - return (rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
> -
> - *rtp = rt;
> - return (0);
> + return (rt);
> }
>
> void
> @@ -1260,6 +1296,8 @@ rt_ifa_add(struct ifaddr *ifa, int flags
>
> error = rtrequest(RTM_ADD, &info, prio, &rt, rtableid);
> if (error == 0) {
> + unsigned int i;
> +
> /*
> * A local route is created for every address configured
> * on an interface, so use this information to notify
> @@ -1269,6 +1307,18 @@ rt_ifa_add(struct ifaddr *ifa, int flags
> rt_sendaddrmsg(rt, RTM_NEWADDR, ifa);
> rt_sendmsg(rt, RTM_ADD, rtableid);
> rtfree(rt);
> +
> + /*
> + * Userland inserted routes stay in the table even
> + * if their corresponding ``ifa'' is no longer valid.
> + *
> + * Try to fix the stale RTF_GATEWAY entries in case
> + * their gateway match the newly inserted route.
> + */
> + for (i = 0; i <= RT_TABLEID_MAX; i++) {
> + rtable_walk(i, ifa->ifa_addr->sa_family,
> + rt_fixgwroute, ifp);
> + }
> }
> return (error);
> }
> @@ -1788,7 +1838,8 @@ rt_if_linkstate_change(struct rtentry *r
> * from down interfaces so we have a chance to get
> * new routes from a better source.
> */
> - if (ISSET(rt->rt_flags, RTF_CLONED|RTF_DYNAMIC)) {
> + if (ISSET(rt->rt_flags, RTF_CLONED|RTF_DYNAMIC) &&
> + !ISSET(rt->rt_flags, RTF_CACHED)) {
> int error;
>
> if ((error = rtdeletemsg(rt, ifp, id)))
> Index: net/route.h
> ===================================================================
> RCS file: /cvs/src/sys/net/route.h,v
> retrieving revision 1.141
> diff -u -p -r1.141 route.h
> --- net/route.h 13 Jul 2016 08:40:46 -0000 1.141
> +++ net/route.h 15 Aug 2016 08:11:14 -0000
> @@ -103,7 +103,12 @@ struct rtentry {
> struct ifaddr *rt_ifa; /* the answer: interface addr to use */
> caddr_t rt_llinfo; /* pointer to link level info cache or
> to an MPLS structure */
> - struct rtentry *rt_gwroute; /* implied entry for gatewayed routes */
> + union {
> + struct rtentry *_nh; /* implied entry for gatewayed routes */
> + unsigned int _ref; /* # gatewayed caching this route */
> + } RT_gw;
> +#define rt_gwroute RT_gw._nh
> +#define rt_cachecnt RT_gw._ref
> struct rtentry *rt_parent; /* If cloned, parent of this route. */
> LIST_HEAD(, rttimer) rt_timer; /* queue of timeouts for misc funcs */
> struct rt_kmetrics rt_rmx; /* metrics used by rx'ing protocols */
> @@ -139,6 +144,7 @@ struct rtentry {
> #define RTF_ANNOUNCE RTF_PROTO2 /* announce L2 entry */
> #define RTF_PROTO1 0x8000 /* protocol specific routing flag */
> #define RTF_CLONED 0x10000 /* this is a cloned route */
> +#define RTF_CACHED 0x20000 /* cached by a RTF_GATEWAY entry */
> #define RTF_MPATH 0x40000 /* multipath route or operation */
> #define RTF_MPLS 0x100000 /* MPLS additional infos */
> #define RTF_LOCAL 0x200000 /* route to a local address */
> @@ -227,6 +233,7 @@ struct rt_msghdr {
> #define RTM_IFINFO 0xe /* iface going up/down etc. */
> #define RTM_IFANNOUNCE 0xf /* iface arrival/departure */
> #define RTM_DESYNC 0x10 /* route socket buffer overflow */
> +#define RTM_INVALIDATE 0x11 /* Invalidate cache of L2 route */
>
> #define RTV_MTU 0x1 /* init or lock _mtu */
> #define RTV_HOPCOUNT 0x2 /* init or lock _hopcount */
> @@ -363,7 +370,7 @@ void rt_sendmsg(struct rtentry *, int,
> void rt_sendaddrmsg(struct rtentry *, int, struct ifaddr *);
> void rt_missmsg(int, struct rt_addrinfo *, int, uint8_t, u_int, int, u_int);
> int rt_setgate(struct rtentry *, struct sockaddr *, u_int);
> -int rt_checkgate(struct rtentry *, struct rtentry **);
> +struct rtentry *rt_getll(struct rtentry *);
> void rt_setmetrics(u_long, const struct rt_metrics *, struct rt_kmetrics *);
> void rt_getmetrics(const struct rt_kmetrics *, struct rt_metrics *);
>
> Index: net/rtsock.c
> ===================================================================
> RCS file: /cvs/src/sys/net/rtsock.c,v
> retrieving revision 1.194
> diff -u -p -r1.194 rtsock.c
> --- net/rtsock.c 11 Jul 2016 13:06:31 -0000 1.194
> +++ net/rtsock.c 15 Aug 2016 08:42:49 -0000
> @@ -556,7 +556,7 @@ route_output(struct mbuf *m, ...)
>
> /* make sure that kernel-only bits are not set */
> rtm->rtm_priority &= RTP_MASK;
> - rtm->rtm_flags &= ~(RTF_DONE|RTF_CLONED);
> + rtm->rtm_flags &= ~(RTF_DONE|RTF_CLONED|RTF_CACHED);
> rtm->rtm_fmask &= RTF_FMASK;
>
> if (rtm->rtm_priority != 0) {
> @@ -615,7 +615,27 @@ route_output(struct mbuf *m, ...)
> }
> break;
> case RTM_DELETE:
> - error = rtrequest(RTM_DELETE, &info, prio, &rt, tableid);
> + if (!rtable_exists(tableid)) {
> + error = EAFNOSUPPORT;
> + goto flush;
> + }
> +
> + rt = rtable_lookup(tableid, info.rti_info[RTAX_DST],
> + info.rti_info[RTAX_NETMASK], info.rti_info[RTAX_GATEWAY],
> + prio);
> +
> + if (rt != NULL) {
> + /* Only invalidate the cache of L2 entries */
> + if (ISSET(rt->rt_flags, RTF_LLINFO)) {
> + ifp = if_get(rt->rt_ifidx);
> + KASSERT(ifp != NULL);
> + ifp->if_rtrequest(ifp, RTM_INVALIDATE, rt);
> + if_put(ifp);
> + goto report;
> + }
> + }
> +
> + error = rtrequest(RTM_DELETE, &info, prio, NULL, tableid);
> if (error == 0)
> goto report;
> break;
> Index: netinet/if_ether.c
> ===================================================================
> RCS file: /cvs/src/sys/netinet/if_ether.c,v
> retrieving revision 1.220
> diff -u -p -r1.220 if_ether.c
> --- netinet/if_ether.c 14 Jul 2016 14:01:40 -0000 1.220
> +++ netinet/if_ether.c 15 Aug 2016 08:25:35 -0000
> @@ -78,6 +78,7 @@ int arpt_prune = (5 * 60); /* walk list
> int arpt_keep = (20 * 60); /* once resolved, cache for 20 minutes */
> int arpt_down = 20; /* once declared down, don't send for 20 secs */
>
> +void arpinvalidate(struct rtentry *);
> void arptfree(struct rtentry *);
> void arptimer(void *);
> struct rtentry *arplookup(struct in_addr *, int, int, unsigned int);
> @@ -215,6 +216,12 @@ arp_rtrequest(struct ifnet *ifp, int req
> rt->rt_flags &= ~RTF_LLINFO;
> la_hold_total -= ml_purge(&la->la_ml);
> pool_put(&arp_pool, la);
> + break;
> +
> + case RTM_INVALIDATE:
> + if (!ISSET(rt->rt_flags, RTF_LOCAL))
> + arpinvalidate(rt);
> + break;
> }
> }
>
> @@ -306,7 +313,6 @@ arpresolve(struct ifnet *ifp, struct rte
> struct sockaddr_dl *sdl;
> struct rtentry *rt = NULL;
> char addr[INET_ADDRSTRLEN];
> - int error;
>
> if (m->m_flags & M_BCAST) { /* broadcast */
> memcpy(desten, etherbroadcastaddr, sizeof(etherbroadcastaddr));
> @@ -317,10 +323,12 @@ arpresolve(struct ifnet *ifp, struct rte
> return (0);
> }
>
> - error = rt_checkgate(rt0, &rt);
> - if (error) {
> + rt = rt_getll(rt0);
> +
> + if (ISSET(rt->rt_flags, RTF_REJECT) &&
> + (rt->rt_expire == 0 || time_uptime < rt->rt_expire)) {
> m_freem(m);
> - return (error);
> + return (rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
> }
>
> if (!ISSET(rt->rt_flags, RTF_LLINFO)) {
> @@ -667,23 +675,31 @@ arpcache(struct ifnet *ifp, struct ether
>
> return (0);
> }
> +
> +void
> +arpinvalidate(struct rtentry *rt)
> +{
> + struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo;
> + struct sockaddr_dl *sdl = satosdl(rt->rt_gateway);
> +
> + la_hold_total -= ml_purge(&la->la_ml);
> + sdl->sdl_alen = 0;
> + la->la_asked = 0;
> +}
> +
> /*
> * Free an arp entry.
> */
> void
> arptfree(struct rtentry *rt)
> {
> - struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo;
> - struct sockaddr_dl *sdl = satosdl(rt->rt_gateway);
> struct ifnet *ifp;
>
> - ifp = if_get(rt->rt_ifidx);
> - if ((sdl != NULL) && (sdl->sdl_family == AF_LINK)) {
> - sdl->sdl_alen = 0;
> - la->la_asked = 0;
> - }
> + arpinvalidate(rt);
>
> - if (!ISSET(rt->rt_flags, RTF_STATIC))
> + ifp = if_get(rt->rt_ifidx);
> + KASSERT(ifp != NULL);
> + if (!ISSET(rt->rt_flags, RTF_STATIC|RTF_CACHED))
> rtdeletemsg(rt, ifp, ifp->if_rdomain);
> if_put(ifp);
> }
> Index: netinet6/nd6.c
> ===================================================================
> RCS file: /cvs/src/sys/netinet6/nd6.c,v
> retrieving revision 1.188
> diff -u -p -r1.188 nd6.c
> --- netinet6/nd6.c 13 Jul 2016 08:40:46 -0000 1.188
> +++ netinet6/nd6.c 15 Aug 2016 08:26:22 -0000
> @@ -93,6 +93,7 @@ struct nd_prhead nd_prefix = { 0 };
> int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
>
> void nd6_slowtimo(void *);
> +void nd6_invalidate(struct rtentry *);
> struct llinfo_nd6 *nd6_free(struct rtentry *, int);
> void nd6_llinfo_timer(void *);
>
> @@ -711,6 +712,17 @@ nd6_is_addr_neighbor(struct sockaddr_in6
> return (0);
> }
>
> +void
> +nd6_invalidate(struct rtentry *rt)
> +{
> + struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
> +
> + m_freem(ln->ln_hold);
> + ln->ln_hold = NULL;
> + ln->ln_state = ND6_LLINFO_INCOMPLETE;
> + ln->ln_asked = 0;
> +}
> +
> /*
> * Free an nd6 llinfo entry.
> * Since the function would cause significant changes in the kernel, DO NOT
> @@ -814,7 +826,7 @@ nd6_free(struct rtentry *rt, int gc)
> * caches, and disable the route entry not to be used in already
> * cached routes.
> */
> - if (!ISSET(rt->rt_flags, RTF_STATIC))
> + if (!ISSET(rt->rt_flags, RTF_STATIC|RTF_CACHED))
> rtdeletemsg(rt, ifp, ifp->if_rdomain);
> splx(s);
>
> @@ -1097,6 +1109,11 @@ nd6_rtrequest(struct ifnet *ifp, int req
> rt->rt_flags &= ~RTF_LLINFO;
> m_freem(ln->ln_hold);
> pool_put(&nd6_pool, ln);
> + break;
> +
> + case RTM_INVALIDATE:
> + nd6_invalidate(rt);
> + break;
> }
> }
>
> @@ -1495,18 +1512,13 @@ nd6_resolve(struct ifnet *ifp, struct rt
> struct sockaddr_dl *sdl;
> struct rtentry *rt;
> struct llinfo_nd6 *ln = NULL;
> - int error;
>
> if (m->m_flags & M_MCAST) {
> ETHER_MAP_IPV6_MULTICAST(&satosin6(dst)->sin6_addr, desten);
> return (0);
> }
>
> - error = rt_checkgate(rt0, &rt);
> - if (error) {
> - m_freem(m);
> - return (error);
> - }
> + rt = rt_getll(rt0);
>
> /*
> * Address resolution or Neighbor Unreachability Detection
>
