nuttx-apps/netutils/netlib/netlib_ipv4router.c
Alin Jerpelea 0a6b1f55ab netutils: update licenses to Apache
Gregory Nutt is has submitted the SGA

Sebastien Lorquet has submitted the ICLA

as a result we can migrate the licenses to Apache.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-06-11 05:05:27 -05:00

122 lines
3.6 KiB
C

/****************************************************************************
* netutils/netlib/netlib_ipv4router.c
*
* 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 <stdio.h>
#include <errno.h>
#include <arpa/inet.h>
#include <nuttx/net/ip.h>
#include "netutils/netlib.h"
#if defined(CONFIG_NET_IPv4) && defined(HAVE_ROUTE_PROCFS)
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: netlib_ipv4router
*
* Description:
* Given a destination address that is not on a local network, query the
* IPv4 routing table, and return the IPv4 address of the routing that
* will provide access to the correct sub-net.
*
* Input Parameters:
* destipaddr - The destination address to use in the look-up (in network
* byte order).
* router - The location to return that the IP address of the router
* (in network byte order)
*
* Returned Value:
* Zero is returned on success; a negated errno value is returned on any
* failure.
*
****************************************************************************/
int netlib_ipv4router(FAR const struct in_addr *destipaddr,
FAR struct in_addr *router)
{
struct netlib_ipv4_route_s route;
FILE *stream;
in_addr_t hdest;
ssize_t nbytes;
int ret = -ENOENT;
/* Open the routing table file */
stream = netlib_open_ipv4route();
if (stream == NULL)
{
return -errno;
}
/* Convert the destination IP address to host byte order for the
* comparison.
*/
hdest = ntohl(destipaddr->s_addr);
/* Find the routing table entry that provides the router for this sub-net. */
for (; ; )
{
/* Read the route (in host byte order) */
nbytes = netlib_read_ipv4route(stream, &route);
if (nbytes == 0)
{
/* End of file with no match */
break;
}
else if (nbytes < 0)
{
/* Read error */
ret = (int)nbytes;
break;
}
/* Compare the prefix and the destination address under the mask */
if (net_ipv4addr_maskcmp(route.prefix, hdest, route.netmask))
{
/* Found it! Return the router address in network byte order */
router->s_addr = htonl(route.router);
ret = OK;
break;
}
}
netlib_close_ipv4route(stream);
return ret;
}
#endif /* CONFIG_NET_IPv4 && HAVE_ROUTE_PROCFS */