1 /* net/if.h -- declarations for inquiring about network interfaces
2    Copyright (C) 2000-2021 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef _NET_IF_H
20 
21 #define _NET_IF_H	1
22 #include <features.h>
23 
24 
25 __BEGIN_DECLS
26 
27 /* Convert an interface name to an index, and vice versa.  */
28 
29 extern unsigned int if_nametoindex (const char *__ifname) __THROW;
30 extern char *if_indextoname (unsigned int __ifindex, char *__ifname) __THROW;
31 
32 /* Return a list of all interfaces and their indices.  */
33 
34 struct if_nameindex
35   {
36     unsigned int if_index;	/* 1, 2, ... */
37     char *if_name;		/* null terminated name: "eth0", ... */
38   };
39 
40 extern struct if_nameindex *if_nameindex (void) __THROW;
41 
42 /* Free the data returned from if_nameindex.  */
43 
44 extern void if_freenameindex (struct if_nameindex *__ptr) __THROW;
45 
46 __END_DECLS
47 
48 
49 #endif /* net/if.h */
50