/****************************************************************************
* 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 "devif/devif.h"
#include "route/route.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* 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:
* ripaddr - Remote address of a connection to use in the lookup
*
* 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 ripaddr)
{
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, ripaddr, 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:
* lipaddr - Local, bound address of a connection. Used only if ripaddr
* is the broadcast address. Used only if CONFIG_NET_MULTILINK.
* ripaddr - Remote address of a connection to use in the lookup
*
* Returned Value:
* Pointer to driver on success; null on failure
*
* Assumptions:
* Called from normal user mode
*
****************************************************************************/
#ifdef CONFIG_NET_MULTILINK
FAR struct net_driver_s *netdev_findbyaddr(const net_ipaddr_t lipaddr,
const net_ipaddr_t ripaddr)
#else
FAR struct net_driver_s *netdev_findbyaddr(const net_ipaddr_t ripaddr)
#endif
{
struct net_driver_s *dev;
#ifdef CONFIG_NET_ROUTE
net_ipaddr_t router;
int ret;
#endif
/* First, check if this is the broadcast IP address */
if (net_ipaddr_cmp(ripaddr, g_alloneaddr))
{
#ifdef CONFIG_NET_MULTILINK
/* Yes.. Check the local, bound address. Is it INADDR_ANY? */
if (net_ipaddr_cmp(lipaddr, g_allzeroaddr))
{
/* Yes.. In this case, I think we are supposed to send the
* broadcast packet out ALL local networks. I am not sure
* of that and, in any event, there is nothing we can do
* about that here.
*/
return NULL;
}
else
{
/* Return the device associated with the local address */
return netdev_finddevice(lipaddr);
}
#else
/* If there is only a single, registered network interface, then the
* decision is pretty easy.
*/
return g_netdevices;
#endif
}
/* Check if the address maps to a local network */
dev = netdev_finddevice(ripaddr);
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(ripaddr, router);
#else
ret = net_router(ripaddr, &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.
*/
#ifndef CONFIG_NET_MULTILINK
/* If there is only a single, registered network interface, then the
* decision is pretty easy. Use that device and its default router
* address.
*/
dev = g_netdevices;
#endif
/* 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
* destination.
*/
return dev;
}
#endif /* CONFIG_NET && CONFIG_NSOCKET_DESCRIPTORS */
