nuttx/net/netdev/netdev_foreach.c

/****************************************************************************
 * net/netdev/netdev_foreach.c
 *
 *   Copyright (C) 2007-2009, 2012, 2015 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <debug.h>

#include <nuttx/net/netdev.h>

#include "netdev/netdev.h"

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: netdev_foreach
 *
 * Description:
 *   Enumerate each registered network device.  This function will terminate
 *   when either (1) all devices have been enumerated or (2) when a callback
 *   returns any non-zero value.
 *
 *   NOTE 1:  The network must be locked throughout the enumeration.
 *   NOTE 2:  No checks are made on devices.  For examples, callbacks will
 *            will be made on network devices that are in the 'down' state.
 *            The callback implementations must take into account all
 *            network device state.  Typically, a network in the down state
 *            would not terminate the traversal.
 *
 * Input Parameters:
 *   callback - Will be called for each registered device
 *   arg      - Opaque user argument passed to callback()
 *
 * Returned Value:
 *  0: Enumeration completed
 *  1: Enumeration terminated early by callback
 *
 * Assumptions:
 *  The network is locked.
 *
 ****************************************************************************/

int netdev_foreach(netdev_callback_t callback, FAR void *arg)
{
  FAR struct net_driver_s *dev;
  int ret = 0;

  if (callback != NULL)
    {
      for (dev = g_netdevices; dev; dev = dev->flink)
        {
          if (callback(dev, arg) != 0)
            {
              ret = 1;
              break;
            }
        }
    }

  return ret;
}