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Commit 5e5cbc7b authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nf_conncount: expose connection list interface 



This patch provides an interface to maintain the list of connections and
the lookup function to obtain the number of connections in the list.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 00bfb320

include/net/netfilter/nf_conntrack_count.h

+11 −0
Original line number Diff line number Diff line
@@ -13,4 +13,15 @@ unsigned int nf_conncount_count(struct net *net, 
				const u32 *key,

				const struct nf_conntrack_tuple *tuple,

				const struct nf_conntrack_zone *zone);



unsigned int nf_conncount_lookup(struct net *net, struct hlist_head *head,

				 const struct nf_conntrack_tuple *tuple,

				 const struct nf_conntrack_zone *zone,

				 bool *addit);



bool nf_conncount_add(struct hlist_head *head,

		      const struct nf_conntrack_tuple *tuple);



void nf_conncount_cache_free(struct hlist_head *hhead);



#endif

net/netfilter/nf_conncount.c

+23 −13
Original line number Diff line number Diff line
@@ -79,7 +79,7 @@ static int key_diff(const u32 *a, const u32 *b, unsigned int klen) 
	return memcmp(a, b, klen * sizeof(u32));

}



static bool add_hlist(struct hlist_head *head,

bool nf_conncount_add(struct hlist_head *head,

		      const struct nf_conntrack_tuple *tuple)

{

	struct nf_conncount_tuple *conn;
@@ -91,9 +91,9 @@ static bool add_hlist(struct hlist_head *head, 
	hlist_add_head(&conn->node, head);

	return true;

}

EXPORT_SYMBOL_GPL(nf_conncount_add);



static unsigned int check_hlist(struct net *net,

				struct hlist_head *head,

unsigned int nf_conncount_lookup(struct net *net, struct hlist_head *head,

				 const struct nf_conntrack_tuple *tuple,

				 const struct nf_conntrack_zone *zone,

				 bool *addit)
@@ -141,6 +141,7 @@ static unsigned int check_hlist(struct net *net, 


	return length;

}

EXPORT_SYMBOL_GPL(nf_conncount_lookup);



static void tree_nodes_free(struct rb_root *root,

			    struct nf_conncount_rb *gc_nodes[],
@@ -187,13 +188,15 @@ count_tree(struct net *net, struct rb_root *root, 
		} else {

			/* same source network -> be counted! */

			unsigned int count;

			count = check_hlist(net, &rbconn->hhead, tuple, zone, &addit);



			count = nf_conncount_lookup(net, &rbconn->hhead, tuple,

						    zone, &addit);



			tree_nodes_free(root, gc_nodes, gc_count);

			if (!addit)

				return count;



			if (!add_hlist(&rbconn->hhead, tuple))

			if (!nf_conncount_add(&rbconn->hhead, tuple))

				return 0; /* hotdrop */



			return count + 1;
@@ -203,7 +206,7 @@ count_tree(struct net *net, struct rb_root *root, 
			continue;



		/* only used for GC on hhead, retval and 'addit' ignored */

		check_hlist(net, &rbconn->hhead, tuple, zone, &addit);

		nf_conncount_lookup(net, &rbconn->hhead, tuple, zone, &addit);

		if (hlist_empty(&rbconn->hhead))

			gc_nodes[gc_count++] = rbconn;

	}
@@ -303,11 +306,19 @@ struct nf_conncount_data *nf_conncount_init(struct net *net, unsigned int family 
}

EXPORT_SYMBOL_GPL(nf_conncount_init);



static void destroy_tree(struct rb_root *r)

void nf_conncount_cache_free(struct hlist_head *hhead)

{

	struct nf_conncount_tuple *conn;

	struct nf_conncount_rb *rbconn;

	struct hlist_node *n;



	hlist_for_each_entry_safe(conn, n, hhead, node)

		kmem_cache_free(conncount_conn_cachep, conn);

}

EXPORT_SYMBOL_GPL(nf_conncount_cache_free);



static void destroy_tree(struct rb_root *r)

{

	struct nf_conncount_rb *rbconn;

	struct rb_node *node;



	while ((node = rb_first(r)) != NULL) {
@@ -315,8 +326,7 @@ static void destroy_tree(struct rb_root *r) 


		rb_erase(node, r);



		hlist_for_each_entry_safe(conn, n, &rbconn->hhead, node)

			kmem_cache_free(conncount_conn_cachep, conn);

		nf_conncount_cache_free(&rbconn->hhead);



		kmem_cache_free(conncount_rb_cachep, rbconn);

	}