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/****************************************************************************
* net/netdev/netdev_findbyaddr.c
*
* Copyright (C) 2007-2009, 2014 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>
#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include "netdev/netdev.h"
#include "route/route.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Function: netdev_maskcmp
****************************************************************************/
/****************************************************************************
* Function: netdev_finddevice
*
* Description:
* Find a previously registered network device by matching a local address
* with the subnet served by the device. Only "up" devices are considered
* (since a "down" device has no meaningful address).
*
* Parameters:
* addr - Pointer to the remote address of a connection
*
* Returned Value:
* Pointer to driver on success; null on failure
*
* Assumptions:
* Called from normal user mode
*
****************************************************************************/
static FAR struct net_driver_s *netdev_finddevice(const net_ipaddr_t addr)
{
FAR struct net_driver_s *dev;
/* Examine each registered network device */
netdev_semtake();
for (dev = g_netdevices; dev; dev = dev->flink)
{
/* Is the interface in the "up" state? */
if ((dev->d_flags & IFF_UP) != 0)
{
/* Yes.. check for an address match (under the netmask) */
if (net_ipaddr_maskcmp(dev->d_ipaddr, addr, dev->d_netmask))
{
/* Its a match */
netdev_semgive();
return dev;
}
}
}
/* No device with the matching address found */
netdev_semgive();
return NULL;
}
/****************************************************************************
* Global Functions
****************************************************************************/
/****************************************************************************
* Function: netdev_findbyaddr
*
* Description:
* Find a previously registered network device by matching an arbitrary
* IP address.
*
* Parameters:
* addr - Pointer to the remote address of a connection
*
* Returned Value:
* Pointer to driver on success; null on failure
*
* Assumptions:
* Called from normal user mode
*
****************************************************************************/
FAR struct net_driver_s *netdev_findbyaddr(const net_ipaddr_t addr)
{
struct net_driver_s *dev;
#ifdef CONFIG_NET_ROUTE
net_ipaddr_t router;
int ret;
#endif
/* First, see if the address maps to the a local network */
dev = netdev_finddevice(addr);
if (dev)
{
return dev;
}
/* No.. The address lies on an external network */
#ifdef CONFIG_NET_ROUTE
/* If we have a routing table, then perhaps we can find the local
* address of a router that can forward packets to the external network.
*/
#ifdef CONFIG_NET_IPv6
ret = net_router(addr, router);
#else
ret = net_router(addr, &router);
#endif
if (ret >= 0)
{
/* Success... try to find the network device associated with the local
* router address
*/
dev = netdev_finddevice(router);
if (dev)
{
return dev;
}
}
#endif /* CONFIG_NET_ROUTE */
/* The above lookup will fail if the packet is being sent out of our
* out subnet to a router and there is no routing information.
*
* However, if there is only a single, registered network interface, then
* the decision is pretty easy. Use that device and its default router
* address.
*
* REVISIT: This logic is lame. Also, in the case where the socket is
* bound to INADDRY_ANY, we should return the default network device
* (from netdev_default()).
*/
netdev_semtake();
if (g_netdevices && !g_netdevices->flink)
{
dev = g_netdevices;
}
netdev_semgive();
/* If we will did not find the network device, then we might as well fail
* because we are not configured properly to determine the route to the
* target.
*/
return dev;
}
#endif /* CONFIG_NET && CONFIG_NSOCKET_DESCRIPTORS */
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