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Commit f39925db authored by David S. Miller's avatar David S. Miller
Browse files

ipv4: Cache learned redirect information in inetpeer. 



Note that we do not generate the redirect netevent any longer,
because we don't create a new cached route.

Instead, once the new neighbour is bound to the cached route,
we emit a neigh update event instead.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2c8cec5c

net/ipv4/route.c

+42 −94
Original line number Diff line number Diff line
@@ -1294,13 +1294,8 @@ static void rt_del(unsigned hash, struct rtable *rt) 
void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,

		    __be32 saddr, struct net_device *dev)

{

	int i, k;

	struct in_device *in_dev = __in_dev_get_rcu(dev);

	struct rtable *rth;

	struct rtable __rcu **rthp;

	__be32  skeys[2] = { saddr, 0 };

	int  ikeys[2] = { dev->ifindex, 0 };

	struct netevent_redirect netevent;

	struct inet_peer *peer;

	struct net *net;



	if (!in_dev)
@@ -1312,9 +1307,6 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, 
	    ipv4_is_zeronet(new_gw))

		goto reject_redirect;



	if (!rt_caching(net))

		goto reject_redirect;



	if (!IN_DEV_SHARED_MEDIA(in_dev)) {

		if (!inet_addr_onlink(in_dev, new_gw, old_gw))

			goto reject_redirect;
@@ -1325,93 +1317,13 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, 
			goto reject_redirect;

	}



	for (i = 0; i < 2; i++) {

		for (k = 0; k < 2; k++) {

			unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],

						rt_genid(net));



			rthp = &rt_hash_table[hash].chain;



			while ((rth = rcu_dereference(*rthp)) != NULL) {

				struct rtable *rt;



				if (rth->fl.fl4_dst != daddr ||

				    rth->fl.fl4_src != skeys[i] ||

				    rth->fl.oif != ikeys[k] ||

				    rt_is_input_route(rth) ||

				    rt_is_expired(rth) ||

				    !net_eq(dev_net(rth->dst.dev), net)) {

					rthp = &rth->dst.rt_next;

					continue;

				}



				if (rth->rt_dst != daddr ||

				    rth->rt_src != saddr ||

				    rth->dst.error ||

				    rth->rt_gateway != old_gw ||

				    rth->dst.dev != dev)

					break;



				dst_hold(&rth->dst);



				rt = dst_alloc(&ipv4_dst_ops);

				if (rt == NULL) {

					ip_rt_put(rth);

					return;

				}



				/* Copy all the information. */

				*rt = *rth;

				rt->dst.__use		= 1;

				atomic_set(&rt->dst.__refcnt, 1);

				rt->dst.child		= NULL;

				if (rt->dst.dev)

					dev_hold(rt->dst.dev);

				rt->dst.obsolete	= -1;

				rt->dst.lastuse	= jiffies;

				rt->dst.path		= &rt->dst;

				rt->dst.neighbour	= NULL;

				rt->dst.hh		= NULL;

#ifdef CONFIG_XFRM

				rt->dst.xfrm		= NULL;

#endif

				rt->rt_genid		= rt_genid(net);

				rt->rt_flags		|= RTCF_REDIRECTED;



				/* Gateway is different ... */

				rt->rt_gateway		= new_gw;



				/* Redirect received -> path was valid */

				dst_confirm(&rth->dst);



				if (rt->peer)

					atomic_inc(&rt->peer->refcnt);

				if (rt->fi)

					atomic_inc(&rt->fi->fib_clntref);



				if (arp_bind_neighbour(&rt->dst) ||

				    !(rt->dst.neighbour->nud_state &

					    NUD_VALID)) {

					if (rt->dst.neighbour)

						neigh_event_send(rt->dst.neighbour, NULL);

					ip_rt_put(rth);

					rt_drop(rt);

					goto do_next;

				}

	peer = inet_getpeer_v4(daddr, 1);

	if (peer) {

		peer->redirect_learned.a4 = new_gw;



				netevent.old = &rth->dst;

				netevent.new = &rt->dst;

				call_netevent_notifiers(NETEVENT_REDIRECT,

							&netevent);

		inet_putpeer(peer);



				rt_del(hash, rth);

				if (!rt_intern_hash(hash, rt, &rt, NULL, rt->fl.oif))

					ip_rt_put(rt);

				goto do_next;

			}

		do_next:

			;

		}

		atomic_inc(&__rt_peer_genid);

	}

	return;
@@ -1678,6 +1590,31 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) 
	}

}



static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)

{

	struct rtable *rt = (struct rtable *) dst;

	__be32 orig_gw = rt->rt_gateway;



	dst_confirm(&rt->dst);



	neigh_release(rt->dst.neighbour);

	rt->dst.neighbour = NULL;



	rt->rt_gateway = peer->redirect_learned.a4;

	if (arp_bind_neighbour(&rt->dst) ||

	    !(rt->dst.neighbour->nud_state & NUD_VALID)) {

		if (rt->dst.neighbour)

			neigh_event_send(rt->dst.neighbour, NULL);

		rt->rt_gateway = orig_gw;

		return -EAGAIN;

	} else {

		rt->rt_flags |= RTCF_REDIRECTED;

		call_netevent_notifiers(NETEVENT_NEIGH_UPDATE,

					rt->dst.neighbour);

	}

	return 0;

}



static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)

{

	struct rtable *rt = (struct rtable *) dst;
@@ -1694,6 +1631,12 @@ static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 
		if (peer && peer->pmtu_expires)

			check_peer_pmtu(dst, peer);



		if (peer && peer->redirect_learned.a4 &&

		    peer->redirect_learned.a4 != rt->rt_gateway) {

			if (check_peer_redir(dst, peer))

				return NULL;

		}



		rt->rt_peer_genid = rt_peer_genid();

	}

	return dst;
@@ -1830,6 +1773,11 @@ static void rt_init_metrics(struct rtable *rt, struct fib_info *fi) 


		if (peer->pmtu_expires)

			check_peer_pmtu(&rt->dst, peer);

		if (peer->redirect_learned.a4 &&

		    peer->redirect_learned.a4 != rt->rt_gateway) {

			rt->rt_gateway = peer->redirect_learned.a4;

			rt->rt_flags |= RTCF_REDIRECTED;

		}

	} else {

		if (fi->fib_metrics != (u32 *) dst_default_metrics) {

			rt->fi = fi;