1 /* if_index.c
2 **
3 ** Copyright 2007, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");
6 ** you may not use this file except in compliance with the License.
7 ** You may obtain a copy of the License at
8 **
9 ** http://www.apache.org/licenses/LICENSE-2.0
10 **
11 ** Unless required by applicable law or agreed to in writing, software
12 ** distributed under the License is distributed on an "AS IS" BASIS,
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 ** See the License for the specific language governing permissions and
15 ** limitations under the License.
16 */
17
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <unistd.h>
21 #include <errno.h>
22
23 #include <sys/socket.h>
24 #include <sys/select.h>
25 #include <sys/types.h>
26 #include <netinet/in.h>
27
28 #include <linux/if.h>
29 #include <linux/sockios.h>
30 #include <linux/route.h>
31
if_nametoindex(const char * ifname)32 unsigned int if_nametoindex( const char *ifname )
33 {
34 #ifndef SIOCGIFINDEX
35 return 0;
36 #else
37 struct ifreq ifr;
38 int fd = socket(AF_INET, SOCK_DGRAM, 0);
39
40 if (fd < 0)
41 return 0;
42
43 strncpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
44 ifr.ifr_ifindex = 0;
45 if (ioctl (fd, SIOCGIFINDEX, &ifr) < 0) {
46 return 0;
47 }
48 return ifr.ifr_ifindex;
49 #endif
50 }
51