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/****************************************************************************
* net/route/net_router.c
*
* Copyright (C) 2013 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/ip.h>
#include "devif/devif.h"
#include "route/route.h"
#if defined(CONFIG_NET) && defined(CONFIG_NET_ROUTE)
/****************************************************************************
* Public Types
****************************************************************************/
struct route_match_s
{
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_match
*
* Description:
* Return 1 if the route is available
*
* 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_match(FAR struct net_route_s *route, FAR void *arg)
{
FAR struct route_match_s *match = (FAR struct route_match_s *)arg;
/* To match, the masked target addresses must be the same. In the event
* of multiple matches, only the first is returned. There is not (yet) any
* concept for the precedence of networks.
*/
if (net_ipaddr_maskcmp(route->target, match->target, route->netmask))
{
/* They match.. Copy the router address */
net_ipaddr_copy(match->router, route->router);
return 1;
}
return 0;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Function: net_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.
*
* Parameters:
* 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:
* OK on success; Negated errno on failure.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv6
int net_router(net_ipaddr_t target, net_ipaddr_t router)
#else
int net_router(net_ipaddr_t target, FAR net_ipaddr_t *router)
#endif
{
struct route_match_s match;
int ret;
/* Do not route the special broadcast IP address */
if (net_ipaddr_cmp(target, g_alloneaddr))
{
return -ENOENT;
}
/* Set up the comparison structure */
memset(&match, 0, sizeof(struct route_match_s));
net_ipaddr_copy(match.target, target);
/* Find an router entry with the routing table that can forward to this
* address
*/
ret = net_foreachroute(net_match, &match);
if (ret > 0)
{
/* We found a route. Return the router address. */
#ifdef CONFIG_NET_IPv6
net_ipaddr_copy(router, match.router);
#else
net_ipaddr_copy(*router, match.router);
#endif
ret = OK;
}
else
{
/* There is no route for this address */
ret = -ENOENT;
}
return ret;
}
#endif /* CONFIG_NET && CONFIG_NET_ROUTE */
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