domotz-remote-pawn/src/discovery/bonjour/bonjour_service_browser.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/>.
 **/

var _ = require('underscore');
var q = require('q');
var bonjourFactory = require('bonjour');
var bonjourParser = require("./parsers/base_parser");

// Bonjour module use this options to initialize a mutlicast dns server
// https://www.npmjs.com/package/multicast-dns
const DEFAULT_OPTIONS = {
    host: '224.0.0.251', // N.B. Equivalent to ip
    port: 5353,
    type: 'udp4',
    interface: null, // Just for udp6
    reuseAddr: true, // If another MDNS is on the system
    socket: null, // If you want create your own socket
    multicast: true,
    ttl: 255,
    loopback: true // Set Multicast Loopback
};

const BONJOUR_DISCOVERY_TIMEOUT = 7000;

module.exports.factory = function (opts) {

    opts = opts || _.extend(DEFAULT_OPTIONS);

    var bonjour = bonjourFactory(opts);
    var working = true;

    bonjour._server.mdns.on('error', function(err) {
        console.warn('BONJOUR - (mdns): Error in initializing server: %s', err.message);
        working = false;
    });

    function discover(cb) {

        var result = [];

        if (!working) {
            console.warn('BONJOUR - (mdns): No internal server active. Another MDNS daemon is running.');
            cb([]);
            return;
        }

        var browser = bonjour.find({}, function onUp(s) {
            var entry = bonjourParser.parse(s, s.type);
            result.push(entry);
        });

        setTimeout(function () {
            browser.stop();
            cb(result);
            //bonjour.destroy();
        }, BONJOUR_DISCOVERY_TIMEOUT);
    }

    return {
        discover: discover
    };
};