firewall/nat.py

#! /usr/bin/python3

# 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 3 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, see <http://www.gnu.org/licenses/>.

# Copyright © 2019 Hugo Levy-Falk <me@klafyvel.me>

"""
Creates the nat set.
"""

import logging
import time
from configparser import ConfigParser

import netaddr

from firewall import NAT

CONFIG = ConfigParser()
CONFIG.read('/usr/local/firewall/config.ini')


def create_nat_adherent():
    range_in = CONFIG['NAT']['range_in_adherent']
    range_out = CONFIG['NAT']['range_out_adherent']
    first_port = int(CONFIG['NAT']['first_port_adherent'])
    last_port = int(CONFIG['NAT']['last_port_adherent'])
    return NAT(
        'adherent',
        range_in,
        range_out,
        first_port,
        last_port
    )


def create_nat_federez():
    range_in = CONFIG['NAT']['range_in_federez']
    range_out = CONFIG['NAT']['range_out_federez']
    first_port = int(CONFIG['NAT']['first_port_federez'])
    last_port = int(CONFIG['NAT']['last_port_federez'])
    return NAT(
        'federez',
        range_in,
        range_out,
        first_port,
        last_port
    )


def create_nat_aloes():
    range_in = CONFIG['NAT']['range_in_aloes']
    range_out = CONFIG['NAT']['range_out_aloes']
    first_port = int(CONFIG['NAT']['first_port_aloes'])
    last_port = int(CONFIG['NAT']['last_port_aloes'])
    return NAT(
        'aloes',
        range_in,
        range_out,
        first_port,
        last_port
    )


def create_nat_admin():
    range_in = CONFIG['NAT']['range_in_admin']
    range_out = CONFIG['NAT']['range_out_admin']
    first_port = int(CONFIG['NAT']['first_port_admin'])
    last_port = int(CONFIG['NAT']['last_port_admin'])
    return NAT(
        'admin',
        range_in,
        range_out,
        first_port,
        last_port
    )


def main():
    nat_log = time.ctime() + "\n"
    logging.info("Creating adherent nat...")
    nat_adherent = create_nat_adherent()
    nat_log += "Adherents :\n"
    nat_log += nat_adherent.manage()
    logging.info("Done.")
    logging.info("Creating federez nat...")
    nat_federez = create_nat_federez()
    nat_log += "Federez :\n"
    nat_log += nat_federez.manage()
    logging.info("Done.")
    logging.info("Creating aloes nat...")
    aloes_nat = create_nat_aloes()
    nat_log += "Aloes :\n"
    nat_log += aloes_nat.manage()
    logging.info("Done.")
    logging.info("Creating admin nat...")
    admin_nat = create_nat_admin()
    nat_log += "Admin :\n"
    nat_log += admin_nat.manage()
    logging.info("Done.")

    logging.info("Saving nat table into /var/log/nat.log")
    with open('/var/log/nat.log', 'a') as f:
        f.write(nat_log)


if __name__=='__main__':
    logging.info('Updating the NAT table.')
    main()