Made IP address enumeration more flexible

Also added an option to enumerate addresses on ignored interfaces.

src/libhydra/kernel/kernel_interface.h

@@ -321,14 +321,11 @@ struct kernel_interface_t {
 	 * enumerator gets destroyed.
 	 * The hosts are read-only, do not modify of free.
 	 *
-	 * @param include_down_ifaces	TRUE to enumerate addresses from down interfaces
-	 * @param include_virtual_ips	TRUE to enumerate virtual IP addresses
-	 * @param include_loopback		TRUE to enumerate addresses on loopback interfaces
-	 * @return						enumerator over host_t's
+	 * @param which			a combination of address types to enumerate
+	 * @return				enumerator over host_t's
 	 */
 	enumerator_t *(*create_address_enumerator) (kernel_interface_t *this,
-							bool include_down_ifaces, bool include_virtual_ips,
-							bool include_loopback);
+												kernel_address_type_t which);
 
 	/**
 	 * Add a virtual IP to an interface.