kernel-interface: Add method to enumerate locally attached subnets

src/libcharon/kernel/kernel_interface.h

@@ -315,6 +315,15 @@ struct kernel_interface_t {
 	enumerator_t *(*create_address_enumerator) (kernel_interface_t *this,
 												kernel_address_type_t which);
 
+	/**
+	 * Creates an enumerator over all local subnets.
+	 *
+	 * Local subnets are subnets the host is directly connected to.
+	 *
+	 * @return				enumerator over host_t*, uint8_t
+	 */
+	enumerator_t *(*create_local_subnet_enumerator)(kernel_interface_t *this);
+
 	/**
 	 * Add a virtual IP to an interface.
 	 *