netfilter: nf_conncount: Early exit in nf_conncount_lookup() and cleanup

This patch is originally from Florian Westphal.

This patch does the following three tasks.

It applies the same early exit technique for nf_conncount_lookup().

Since now we keep the number of connections in 'struct nf_conncount_list',
we no longer need to return the count in nf_conncount_lookup().

Moreover, we expose the garbage collection function nf_conncount_gc_list()
for nft_connlimit.

Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_conntrack_count.h

@@ -21,10 +21,10 @@ unsigned int nf_conncount_count(struct net *net,
 				const struct nf_conntrack_tuple *tuple,
 				const struct nf_conntrack_zone *zone);
 
-unsigned int nf_conncount_lookup(struct net *net, struct nf_conncount_list *list,
-				 const struct nf_conntrack_tuple *tuple,
-				 const struct nf_conntrack_zone *zone,
-				 bool *addit);
+void nf_conncount_lookup(struct net *net, struct nf_conncount_list *list,
+			 const struct nf_conntrack_tuple *tuple,
+			 const struct nf_conntrack_zone *zone,
+			 bool *addit);
 
 void nf_conncount_list_init(struct nf_conncount_list *list);
 
@@ -32,6 +32,9 @@ bool nf_conncount_add(struct nf_conncount_list *list,
 		      const struct nf_conntrack_tuple *tuple,
 		      const struct nf_conntrack_zone *zone);
 
+void nf_conncount_gc_list(struct net *net,
+			  struct nf_conncount_list *list);
+
 void nf_conncount_cache_free(struct nf_conncount_list *list);
 
 #endif