incubator-nuttx/net/netdev/netdev_default.c

90 lines
2.9 KiB
C

/****************************************************************************
* net/netdev/netdev_default.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/net/netdev.h>
#include "utils/utils.h"
#include "netdev/netdev.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: netdev_default
*
* Description:
* Return the default network device. REVISIT: At present this function
* arbitrarily returns the first UP device at the head of the device
* list. Perhaps the default device should be a device name
* configuration option?
*
* So why is this here: It represents my current though for what to do
* if a socket is connected with INADDY_ANY. In this case, I suppose we
* should use the IP address associated with some default device???
*
* Input Parameters:
* NULL
*
* Returned Value:
* Pointer to default network driver on success; null on failure
*
****************************************************************************/
FAR struct net_driver_s *netdev_default(void)
{
FAR struct net_driver_s *ret = NULL;
FAR struct net_driver_s *dev;
/* Examine each registered network device */
net_lock();
for (dev = g_netdevices; dev; dev = dev->flink)
{
/* Is the interface in the "up" state? */
if ((dev->d_flags & IFF_UP) != 0)
{
/* Return a reference to the first device that we find in the UP
* state (but not the loopback device unless it is the only
* device).
*/
if (dev->d_lltype != NET_LL_LOOPBACK &&
dev->d_lltype != NET_LL_CAN)
{
ret = dev;
break;
}
}
}
net_unlock();
return ret;
}