def METHOD_NAME(iface):
    '''
    Returns the kernel module used for the give interface
    or None if the module could not be determined of if the
    interface name is wrong.
    Uses '/sys/class/net' to find out the module.
    CLI Example:
    .. code-block:: bash
        salt '*' sumautil.get_net_module eth0
    '''
    sysfspath = os.path.join(SYSFS_NET_PATH, iface, 'device/driver')
    return os.path.exists(sysfspath) and os.path.split(os.readlink(sysfspath))[-1] or None