/* if_index.h   Copyright (C) 2001 Free Software Foundation, Inc.   This program is free software; you can redistribute it and/or   modify it under the terms of the GNU General Public License   as published by the Free Software Foundation; either version 2   of the License, or (at your option) any later version.   This program is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the   GNU General Public License for more details.   You should have received a copy of the GNU General Public License   along with this program; if not, write to the Free Software   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,   MA 02110-1301 USA. */#ifndef IF_INDEX_H#define IF_INDEX_H#ifndef HAVE_STRUCT_IF_NAMEINDEXstruct if_nameindex{  char *if_name;  int if_index;};extern unsigned int if_nametoindex (const char *ifname);extern char *if_indextoname (unsigned int ifindex, char *ifname);extern struct if_nameindex *if_nameindex (void);extern void if_freenameindex (struct if_nameindex *ptr);#endif#endif