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/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
*
* 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.
*/
#include <string.h>
#include <unistd.h>
#include <linux/sockios.h>
#include <net/if.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <errno.h>
/*
* Map an interface index into its name.
* Returns NULL on error.
*/
char*
if_indextoname(unsigned ifindex, char *ifname)
{
int index;
int ctl_sock;
struct ifreq ifr;
char* ret = NULL;
memset(&ifr, 0, sizeof(struct ifreq));
ifr.ifr_ifindex = ifindex;
if ((ctl_sock = socket(AF_INET, SOCK_DGRAM, 0)) >= 0) {
if (ioctl(ctl_sock, SIOCGIFNAME, &ifr) >= 0) {
ret = strncpy (ifname, ifr.ifr_name, IFNAMSIZ);
} else {
/* Posix requires ENXIO */
if (errno == ENODEV)
errno = ENXIO;
}
close(ctl_sock);
}
return ret;
}
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