incubator-nuttx/libs/libc/net/lib_nametoindex.c

70 lines
2.3 KiB
C

/****************************************************************************
* libs/libc/net/lib_nametoindex.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 <net/if.h>
#include <sys/ioctl.h>
#include <string.h>
#include <unistd.h>
#include <nuttx/net/netconfig.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: if_nametoindex
*
* Description:
* The if_nametoindex() function returns the interface index corresponding
* to name ifname.
*
* Input Parameters:
* ifname - The interface name
*
* Returned Value:
* The corresponding index if ifname is the name of an interface;
* otherwise, zero. Although not specified, the errno value will be set.
*
****************************************************************************/
unsigned int if_nametoindex(FAR const char *ifname)
{
int sockfd = socket(NET_SOCK_FAMILY, NET_SOCK_TYPE, NET_SOCK_PROTOCOL);
if (sockfd >= 0)
{
struct ifreq req;
strlcpy(req.ifr_name, ifname, IF_NAMESIZE);
if (ioctl(sockfd, SIOCGIFINDEX, (unsigned long)&req) >= 0)
{
close(sockfd);
return req.ifr_ifindex;
}
close(sockfd);
}
return 0;
}