src/net/nullnet.c

   1 /*
   2  * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 FILE_LICENCE ( GPL2_OR_LATER );
  20
  21 #include <stdint.h>
  22 #include <errno.h>
  23 #include <gpxe/iobuf.h>
  24 #include <gpxe/netdevice.h>
  25
  26 /** @file
  27  *
  28  * Null network device
  29  *
  30  */
  31
  32 static int null_open ( struct net_device *netdev __unused ) {
  33         return -ENODEV;
  34 };
  35
  36 static void null_close ( struct net_device *netdev __unused ) {
  37         /* Do nothing */
  38 };
  39
  40 static int null_transmit ( struct net_device *netdev __unused,
  41                            struct io_buffer *iobuf __unused ) {
  42         return -ENODEV;
  43 };
  44
  45 static void null_poll ( struct net_device *netdev __unused ) {
  46         /* Do nothing */
  47 }
  48
  49 static void null_irq ( struct net_device *netdev __unused,
  50                        int enable __unused ) {
  51         /* Do nothing */
  52 }
  53
  54 struct net_device_operations null_netdev_operations = {
  55         .open           = null_open,
  56         .close          = null_close,
  57         .transmit       = null_transmit,
  58         .poll           = null_poll,
  59         .irq            = null_irq,
  60 };