source: bootcd/isolinux/syslinux-6.03/gpxe/src/net/nullnet.c

/*
 * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <stdint.h>
#include <errno.h>
#include <gpxe/iobuf.h>
#include <gpxe/netdevice.h>

/** @file
 *
 * Null network device
 *
 */

static int null_open ( struct net_device *netdev __unused ) {
        return -ENODEV;
};

static void null_close ( struct net_device *netdev __unused ) {
        /* Do nothing */
};

static int null_transmit ( struct net_device *netdev __unused,
                           struct io_buffer *iobuf __unused ) {
        return -ENODEV;
};

static void null_poll ( struct net_device *netdev __unused ) {
        /* Do nothing */
}

static void null_irq ( struct net_device *netdev __unused,
                       int enable __unused ) {
        /* Do nothing */
}

struct net_device_operations null_netdev_operations = {
        .open           = null_open,
        .close          = null_close,
        .transmit       = null_transmit,
        .poll           = null_poll,
        .irq            = null_irq,
};