-extern int avl_insert();
-extern caddr_t avl_delete();
-extern caddr_t avl_find();
-extern caddr_t avl_getfirst();
-extern caddr_t avl_getnext();
-extern int avl_dup_error();
-extern int avl_apply();
+
+typedef int (*AVL_APPLY) LDAP_P((void *, void*));
+typedef int (*AVL_CMP) LDAP_P((void*, void*));
+typedef int (*AVL_DUP) LDAP_P((void*, void*));
+typedef void (*AVL_FREE) LDAP_P((void*));
+
+LDAP_F int
+avl_free LDAP_P(( Avlnode *root, AVL_FREE dfree ));
+
+LDAP_F int
+avl_insert LDAP_P((Avlnode **, void*, AVL_CMP, AVL_DUP));
+
+LDAP_F void*
+avl_delete LDAP_P((Avlnode **, void*, AVL_CMP));
+
+LDAP_F void*
+avl_find LDAP_P((Avlnode *, void*, AVL_CMP));
+
+LDAP_F void*
+avl_find_lin LDAP_P((Avlnode *, void*, AVL_CMP));
+
+LDAP_F void*
+avl_getfirst LDAP_P((Avlnode *));
+
+#ifdef AVL_REENTRANT
+/* ??? avl.c does not provide this version ??? */
+LDAP_F void*
+avl_getnext LDAP_P((Avlnode *, void* ));
+#else
+LDAP_F void*
+avl_getnext LDAP_P((void));
+#endif
+
+LDAP_F int
+avl_dup_error LDAP_P((void*, void*));
+
+LDAP_F int
+avl_dup_ok LDAP_P((void*, void*));
+
+LDAP_F int
+avl_apply LDAP_P((Avlnode *, AVL_APPLY, void*, int, int));
+
+LDAP_F int
+avl_prefixapply LDAP_P((Avlnode *, void*, AVL_CMP, void*, AVL_CMP, void*, int));