-extern void subnet_add(struct connection_t *, subnet_t *);
-extern void subnet_del(subnet_t *);
+extern void exit_subnets(void);
+extern avl_tree_t *new_subnet_tree(void);
+extern void free_subnet_tree(avl_tree_t *);
+extern void subnet_add(struct node_t *, subnet_t *);
+extern void subnet_del(struct node_t *, subnet_t *);