-extern rbl_t *rbl_search(rbltree_t *, void *);
-extern rbl_t *rbl_search_closest(rbltree_t *, void *);
+extern void *rbl_search(rbltree_t *, void *);
+extern void *rbl_search_closest(rbltree_t *, void *);
+extern void *rbl_search_closest_greater(rbltree_t *, void *);
+extern void *rbl_search_closest_smaller(rbltree_t *, void *);
+extern rbl_t *rbl_search_rbl(rbltree_t *, void *);
+extern rbl_t *rbl_search_closest_rbl(rbltree_t *, void *);
+extern rbl_t *rbl_search_closest_greater_rbl(rbltree_t *, void *);
+extern rbl_t *rbl_search_closest_smaller_rbl(rbltree_t *, void *);