* All callbacks except where otherwise noted should return 0
* on success or a negative error code.
*
+ * All operations are currently invoked under rtnl for consistency with the
+ * wireless extensions but this is subject to reevaluation as soon as this
+ * code is used more widely and we have a first user without wext.
+ *
* @add_virtual_intf: create a new virtual interface with the given name
*
* @del_virtual_intf: remove the virtual interface determined by ifindex.