#!/usr/bin/env python3
#
# Copyright (C) 2021 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# 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, see <http://www.gnu.org/licenses/>.

import os
import re

from sys import argv
from sys import exit

pattern = '^(bond|br|dum|en|ersp|eth|gnv|lan|l2tp|l2tpeth|macsec|peth|ppp|pppoe|pptp|sstp|tun|vti|vtun|vxlan|wg|wlan|wlm)[0-9]+(.\d+)?|lo$'

if __name__ == '__main__':
    if len(argv) != 2:
        exit(1)
    interface = argv[1]

    if re.match(pattern, interface):
        exit(0)
    if os.path.exists(f'/sys/class/net/{interface}'):
        exit(0)
    exit(1)