#!/bin/bash
#
# 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/>.

if [ "$reason" == "REBOOT" ] || [ "$reason" == "EXPIRE" ]; then
    return 0
fi

DHCP_HOOK_IFLIST="/tmp/ipsec_dhcp_waiting"

if [ -f $DHCP_HOOK_IFLIST ] && [ "$reason" == "BOUND" ]; then
    if grep -qw $interface $DHCP_HOOK_IFLIST; then
        sudo rm $DHCP_HOOK_IFLIST
        sudo /usr/libexec/vyos/conf_mode/vpn_ipsec.py
        return 0
    fi
fi

if [ "$old_ip_address" == "$new_ip_address" ] && [ "$reason" == "BOUND" ]; then
    return 0
fi

python3 - <<PYEND
import os
import re

from vyos.utils.process import call
from vyos.utils.process import cmd
from vyos.utils.file import read_file
from vyos.utils.file import write_file

SWANCTL_CONF="/etc/swanctl/swanctl.conf"

if __name__ == '__main__':
    interface = os.getenv('interface')
    new_ip = os.getenv('new_ip_address')
    old_ip = os.getenv('old_ip_address')

    if os.path.exists(SWANCTL_CONF):
        conf_lines = read_file(SWANCTL_CONF).split("\n")
        found = False
        reset_conns = set()
        to_match = f'# dhcp:{interface}'

        for i, line in enumerate(conf_lines):
            if line.find(to_match) > 0:
                conf_lines[i] = line.replace(old_ip, new_ip)
                found = True
                regex_match = re.search(r'#.* reset:([-_a-zA-Z0-9|@]+)', line)
                if regex_match:
                   connection_name = regex_match[1]
                   reset_conns.add(connection_name)

        if found:
            write_file(SWANCTL_CONF, "\n".join(conf_lines))
            for connection_name in reset_conns:
                call(f'sudo swanctl -t -i {connection_name}')
            call('sudo swanctl -q')

    exit(0)
PYEND