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Commit b16cb459 authored by Wei Wang's avatar Wei Wang Committed by David S. Miller
Browse files

ipv6: prepare rt6_clean_tohost() for exception table 



If we move all cached dst into the exception table under the main route,
current rt6_clean_tohost() will no longer be able to access them.
This commit makes fib6_clean_tohost() to also go through all cached
routes in exception table and removes cached gateway routes to the
passed in gateway.
This is a preparation in order to move all cached routes into the
exception table.

Signed-off-by: default avatarWei Wang <weiwan@google.com>
Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f5bbe7ee

net/ipv6/route.c

+47 −1
Original line number Diff line number Diff line
@@ -1491,6 +1491,43 @@ static void rt6_exceptions_update_pmtu(struct rt6_info *rt, int mtu) 
	}

}



#define RTF_CACHE_GATEWAY	(RTF_GATEWAY | RTF_CACHE)



static void rt6_exceptions_clean_tohost(struct rt6_info *rt,

					struct in6_addr *gateway)

{

	struct rt6_exception_bucket *bucket;

	struct rt6_exception *rt6_ex;

	struct hlist_node *tmp;

	int i;



	if (!rcu_access_pointer(rt->rt6i_exception_bucket))

		return;



	spin_lock_bh(&rt6_exception_lock);

	bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,

				     lockdep_is_held(&rt6_exception_lock));



	if (bucket) {

		for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {

			hlist_for_each_entry_safe(rt6_ex, tmp,

						  &bucket->chain, hlist) {

				struct rt6_info *entry = rt6_ex->rt6i;



				if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==

				    RTF_CACHE_GATEWAY &&

				    ipv6_addr_equal(gateway,

						    &entry->rt6i_gateway)) {

					rt6_remove_exception(bucket, rt6_ex);

				}

			}

			bucket++;

		}

	}



	spin_unlock_bh(&rt6_exception_lock);

}



struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,

			       int oif, struct flowi6 *fl6, int flags)

{
@@ -3240,18 +3277,27 @@ void rt6_remove_prefsrc(struct inet6_ifaddr *ifp) 
}



#define RTF_RA_ROUTER		(RTF_ADDRCONF | RTF_DEFAULT | RTF_GATEWAY)

#define RTF_CACHE_GATEWAY	(RTF_GATEWAY | RTF_CACHE)



/* Remove routers and update dst entries when gateway turn into host. */

static int fib6_clean_tohost(struct rt6_info *rt, void *arg)

{

	struct in6_addr *gateway = (struct in6_addr *)arg;



	/* RTF_CACHE_GATEWAY case will be removed once the exception

	 * table is hooked up to store all cached routes.

	 */

	if ((((rt->rt6i_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) ||

	     ((rt->rt6i_flags & RTF_CACHE_GATEWAY) == RTF_CACHE_GATEWAY)) &&

	     ipv6_addr_equal(gateway, &rt->rt6i_gateway)) {

		return -1;

	}



	/* Further clean up cached routes in exception table.

	 * This is needed because cached route may have a different

	 * gateway than its 'parent' in the case of an ip redirect.

	 */

	rt6_exceptions_clean_tohost(rt, gateway);



	return 0;

}