domotz-remote-pawn/src/discovery/ports/scan.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/>.
 *
 * This module executes the scanning of the known TCP Ports for the currently available
 * devices.
 * Created by Iacopo Papalini <iacopo@domotz.com>.
 */
const COOL_DOWN_IN_MS = 2 * 1000;

var factory = function (resourceLocator, specificUtils) {
    var async = resourceLocator.async;
    var commonUtils = require('./utils');
    var indexBindingStorageByMac = commonUtils.indexBindingStorageByMac;
    var history = {};
    var isRunning = false;
    var executionsCounter = 0;
    var host = resourceLocator.discovery.host;
    var baseConsole = resourceLocator.log.decorateLogs();

    function getScanSample(device) {
        if (history[device.mac] === undefined) {
            history[device.mac] = specificUtils.ScanSample(device.mac);
        }
        var scanSample = history[device.mac];
        scanSample.ips = device.ips;
        return scanSample;
    }

    function performDiscovery() {
        executionsCounter += 1;
        var myConsole = baseConsole.decorate(String(executionsCounter));
        if (isRunning) {
            myConsole.warn('Skipping execution, another one still running');
            return;
        }
        isRunning = true;
        var devicesList = indexBindingStorageByMac(resourceLocator.interfacesBindingStorage);
        myConsole.info('There are %s candidate devices', devicesList.length);
        var functions = [];

        devicesList.forEach(function (device) {
             /* Filter devices by removing the ones present in L3 Discovery Deny list */
            if (!host.isDeviceMacInL3DiscoveryDenyList(device.mac)) {
                var sample = getScanSample(device);
                if (sample.stillValid()) {
                    myConsole.debug("Last sample for mac %s still valid, don't scan", sample.mac);
                    return;
                }
                var myConsoleSpecific = myConsole.decorate(sample.mac);
                var context = specificUtils.Context(sample, myConsoleSpecific, resourceLocator);
                functions.push(commonUtils.scanAndReportBuilder(context, resourceLocator));
            } else {
                myConsole.debug('Skip Port Scan for device %s [mac %s] in L3 Discovery Deny List', device.ip, device.mac);
            }
        });

        myConsole.info('Executing on %s devices', functions.length);
        if (functions.length > 0) {
            // Wait a cool-down period before starting the scan so that there a pause between an nmap execution and another
            // mitigating the defensive strategies of some devices that reject too frequent packets
            functions.unshift(function (callback) {
                myConsole.info('Waiting %sms', COOL_DOWN_IN_MS);
                setTimeout(callback, COOL_DOWN_IN_MS);
            });
        }

        async.series(functions, function (err) {
            if (err) {
                myConsole.error('Execution interrupted by error: ' + err);
            }
            myConsole.info('Execution finished');
            isRunning = false;
        });
    }

    return {
        tcpPortScan: performDiscovery,
        udpPortScan: performDiscovery,
        isRunning: function () {
            return isRunning;
        },
    };
};

module.exports.factory = factory;