/****************************************************************************
* net/route/netdev_router.c
*
* Copyright (C) 2013-2014 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>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include "netdev/netdev.h"
#include "route/route.h"
#if defined(CONFIG_NET) && defined(CONFIG_NET_ROUTE)
/****************************************************************************
* Public Types
****************************************************************************/
struct route_devmatch_s
{
FAR struct net_driver_s *dev; /* The route must use this device */
net_ipaddr_t target; /* The target IP address on an external network to match */
net_ipaddr_t router; /* The IP address of the router on one of our networks*/
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Function: net_devmatch
*
* Description:
* Return 1 if the route is available on the device's network.
*
* Parameters:
* route - The next route to examine
* arg - The match values (cast to void*)
*
* Returned Value:
* 0 if the entry is not a match; 1 if the entry matched and was cleared.
*
****************************************************************************/
static int net_devmatch(FAR struct net_route_s *route, FAR void *arg)
{
FAR struct route_devmatch_s *match = (FAR struct route_devmatch_s *)arg;
FAR struct net_driver_s *dev = match->dev;
/* To match, (1) the masked target addresses must be the same, and (2) the
* router address must like on the network provided by the device.
*
* In the event of multiple matches, only the first is returned. There
* not (yet) any concept for the precedence of networks.
*/
if (net_ipaddr_maskcmp(route->target, match->target, route->netmask) &&
net_ipaddr_maskcmp(route->router, dev->d_ipaddr, dev->d_netmask))
{
/* They match.. Copy the router address */
net_ipaddr_copy(match->router, route->router);
return 1;
}
return 0;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Function: netdev_router
*
* Description:
* Given an IP address on a external network, return the address of the
* router on a local network that can forward to the external network.
* This is similar to net_router(). However, the set of routers is
* constrained to those accessible by the specific device
*
* Parameters:
* dev - We are committed to using this device.
* target - An IP address on a remote network to use in the lookup.
* router - The address of router on a local network that can forward our
* packets to the target.
*
* NOTE: For IPv6, router will be an array, for IPv4 it will be a scalar
* value. Hence, the change in the function signature.
*
* Returned Value:
* None
*
****************************************************************************/
#ifdef CONFIG_NET_IPv6
void netdev_router(FAR struct net_driver_s *dev, net_ipaddr_t target,
net_ipaddr_t router)
#else
void netdev_router(FAR struct net_driver_s *dev, net_ipaddr_t target,
FAR net_ipaddr_t *router)
#endif
{
struct route_devmatch_s match;
int ret;
/* Set up the comparison structure */
memset(&match, 0, sizeof(struct route_devmatch_s));
match.dev = dev;
net_ipaddr_copy(match.target, target);
/* Find an router entry with the routing table that can forward to this
* address using this device.
*/
ret = net_foreachroute(net_devmatch, &match);
if (ret > 0)
{
/* We found a route. Return the router address. */
#ifdef CONFIG_NET_IPv6
net_ipaddr_copy(router, match.target);
#else
net_ipaddr_copy(*router, match.target);
#endif
ret = OK;
}
else
{
/* There isn't a matching route.. fallback and use the default router
* of the device.
*/
#ifdef CONFIG_NET_IPv6
net_ipaddr_copy(router, dev->d_draddr);
#else
net_ipaddr_copy(*router, dev->d_draddr);
#endif
}
}
#endif /* CONFIG_NET && CONFIG_NET_ROUTE */
