domotz-remote-pawn/src/network_tools/emergencyNetworkRestore.js

Domotz Agent

/** This file is part of Domotz Agent.
 * Copyright (C) 2016  Domotz Ltd
 *
 * Domotz Agent 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.
 *
 * Domotz Agent 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 Domotz Agent.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Created by Iacopo Papalini <iacopo@domotz.com> on 17/10/2017.
 */

// Time after which we are pretty sure to be offline and actuate emergency network recovery procedures if network management is available
const DEFINITELY_OFFLINE_THRESHOLD_IN_SECONDS = 300;
const EMERGENCY_ADDRESS = '192.168.112.112/24';
const EMERGENCY_DEVICE = 'eth0';
const EMERGENCY_LABEL = 'eth0:112';

module.exports.factory = function (resourceLocator) {
    'use strict';
    var isUbuntuCore = process.env.DPLATFORM === 'ubuntu_core';
    var versionFile = '/opt/domotz_tui/bin/VERSION';
    var networkConfigBin = '/opt/domotz_tui/bin/domotz_network';
    var file = resourceLocator.utils.file;
    var ipWrapper = resourceLocator.utils.ipWrapper;
    var lastFailure = null;
    var emergencyInterfaceEnabled = false;
    var myConsole = resourceLocator.log.decorateLogs();

    var ADDRESS_IDENTIFIER = [EMERGENCY_ADDRESS, 'dev', EMERGENCY_DEVICE, 'label', EMERGENCY_LABEL];

    function canManageNetwork() {
        return (
            (isUbuntuCore && !resourceLocator.utils.platform.isVirtualBox()) ||
            (file.getFileStats(networkConfigBin) && file.getFileStats(versionFile)) ||
            resourceLocator.lodash.get(resourceLocator, 'configuration.settings.emergency_interface.enabled', false)
        );
    }

    function disable() {
        myConsole.debug('Testing if emergency ip address must be disabled');
        if (canManageNetwork()) {
            lastFailure = null;
            if (emergencyInterfaceEnabled) {
                myConsole.info('Connection went up, disabling address %s', EMERGENCY_ADDRESS);
                emergencyInterfaceEnabled = false;
                return ipWrapper.call('addr', 'delete', ADDRESS_IDENTIFIER);
            } else {
                myConsole.debug('Emergency address not enabled, not disabling it');
            }
        } else {
            myConsole.debug('Cannot manage network, disabling not possible');
        }
    }

    function checkEnable() {
        if (!canManageNetwork()) {
            myConsole.debug('Cannot manage network, enabling not possible');
            return;
        }
        var definitely_offline_threshold_in_seconds = resourceLocator.lodash.get(resourceLocator, 'configuration.settings.emergency_interface.threshold_in_s', DEFINITELY_OFFLINE_THRESHOLD_IN_SECONDS);
        if (lastFailure === null) {
            lastFailure = new Date();
            myConsole.info('Connection went down, starting counter to %s seconds for emergency restore', definitely_offline_threshold_in_seconds);
            return;
        }
        var elapsedS = (new Date() - lastFailure) / 1000;
        if (elapsedS > definitely_offline_threshold_in_seconds && !emergencyInterfaceEnabled) {
            emergencyInterfaceEnabled = true;
            myConsole.info('Enabling emergency ip address ' + EMERGENCY_ADDRESS);

            return ipWrapper.call('addr', 'add', ADDRESS_IDENTIFIER);
        }
        myConsole.info('Connection is down, %s seconds passed since first network failure', elapsedS);
    }

    function isEmergencyInterfaceEnabled() {
        return emergencyInterfaceEnabled;
    }

    return {
        disable: disable,
        checkEnable: checkEnable,
        isEmergencyInterfaceEnabled: isEmergencyInterfaceEnabled,
    };
};