summaryrefslogtreecommitdiffstats
path: root/netwerk/dns/mdns/libmdns/fallback/MulticastDNS.jsm
diff options
context:
space:
mode:
Diffstat (limited to 'netwerk/dns/mdns/libmdns/fallback/MulticastDNS.jsm')
-rw-r--r--netwerk/dns/mdns/libmdns/fallback/MulticastDNS.jsm875
1 files changed, 875 insertions, 0 deletions
diff --git a/netwerk/dns/mdns/libmdns/fallback/MulticastDNS.jsm b/netwerk/dns/mdns/libmdns/fallback/MulticastDNS.jsm
new file mode 100644
index 000000000..f43dfd5f8
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/fallback/MulticastDNS.jsm
@@ -0,0 +1,875 @@
+/* -*- Mode: js; js-indent-level: 2; indent-tabs-mode: nil; tab-width: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+/* jshint esnext: true, moz: true */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = ['MulticastDNS'];
+
+const { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
+
+Cu.import('resource://gre/modules/Services.jsm');
+Cu.import('resource://gre/modules/Timer.jsm');
+Cu.import('resource://gre/modules/XPCOMUtils.jsm');
+
+Cu.import('resource://gre/modules/DNSPacket.jsm');
+Cu.import('resource://gre/modules/DNSRecord.jsm');
+Cu.import('resource://gre/modules/DNSResourceRecord.jsm');
+Cu.import('resource://gre/modules/DNSTypes.jsm');
+
+const NS_NETWORK_LINK_TOPIC = 'network:link-status-changed';
+
+let observerService = Cc["@mozilla.org/observer-service;1"]
+ .getService(Components.interfaces.nsIObserverService);
+let networkInfoService = Cc['@mozilla.org/network-info-service;1']
+ .createInstance(Ci.nsINetworkInfoService);
+
+const DEBUG = true;
+
+const MDNS_MULTICAST_GROUP = '224.0.0.251';
+const MDNS_PORT = 5353;
+const DEFAULT_TTL = 120;
+
+function debug(msg) {
+ dump('MulticastDNS: ' + msg + '\n');
+}
+
+function ServiceKey(svc) {
+ return "" + svc.serviceType.length + "/" + svc.serviceType + "|" +
+ svc.serviceName.length + "/" + svc.serviceName + "|" +
+ svc.port;
+}
+
+function TryGet(obj, name) {
+ try {
+ return obj[name];
+ } catch (err) {
+ return undefined;
+ }
+}
+
+function IsIpv4Address(addr) {
+ let parts = addr.split('.');
+ if (parts.length != 4) {
+ return false;
+ }
+ for (let part of parts) {
+ let partInt = Number.parseInt(part, 10);
+ if (partInt.toString() != part) {
+ return false;
+ }
+ if (partInt < 0 || partInt >= 256) {
+ return false;
+ }
+ }
+ return true;
+}
+
+class PublishedService {
+ constructor(attrs) {
+ this.serviceType = attrs.serviceType.replace(/\.$/, '');
+ this.serviceName = attrs.serviceName;
+ this.domainName = TryGet(attrs, 'domainName') || "local";
+ this.address = TryGet(attrs, 'address') || "0.0.0.0";
+ this.port = attrs.port;
+ this.serviceAttrs = _propertyBagToObject(TryGet(attrs, 'attributes') || {});
+ this.host = TryGet(attrs, 'host');
+ this.key = this.generateKey();
+ this.lastAdvertised = undefined;
+ this.advertiseTimer = undefined;
+ }
+
+ equals(svc) {
+ return (this.port == svc.port) &&
+ (this.serviceName == svc.serviceName) &&
+ (this.serviceType == svc.serviceType);
+ }
+
+ generateKey() {
+ return ServiceKey(this);
+ }
+
+ ptrMatch(name) {
+ return name == (this.serviceType + "." + this.domainName);
+ }
+
+ clearAdvertiseTimer() {
+ if (!this.advertiseTimer) {
+ return;
+ }
+ clearTimeout(this.advertiseTimer);
+ this.advertiseTimer = undefined;
+ }
+}
+
+class MulticastDNS {
+ constructor() {
+ this._listeners = new Map();
+ this._sockets = new Map();
+ this._services = new Map();
+ this._discovered = new Map();
+ this._querySocket = undefined;
+ this._broadcastReceiverSocket = undefined;
+ this._broadcastTimer = undefined;
+
+ this._networkLinkObserver = {
+ observe: (subject, topic, data) => {
+ DEBUG && debug(NS_NETWORK_LINK_TOPIC + '(' + data + '); Clearing list of previously discovered services');
+ this._discovered.clear();
+ }
+ };
+ }
+
+ _attachNetworkLinkObserver() {
+ if (this._networkLinkObserverTimeout) {
+ clearTimeout(this._networkLinkObserverTimeout);
+ }
+
+ if (!this._isNetworkLinkObserverAttached) {
+ DEBUG && debug('Attaching observer ' + NS_NETWORK_LINK_TOPIC);
+ observerService.addObserver(this._networkLinkObserver, NS_NETWORK_LINK_TOPIC, false);
+ this._isNetworkLinkObserverAttached = true;
+ }
+ }
+
+ _detachNetworkLinkObserver() {
+ if (this._isNetworkLinkObserverAttached) {
+ if (this._networkLinkObserverTimeout) {
+ clearTimeout(this._networkLinkObserverTimeout);
+ }
+
+ this._networkLinkObserverTimeout = setTimeout(() => {
+ DEBUG && debug('Detaching observer ' + NS_NETWORK_LINK_TOPIC);
+ observerService.removeObserver(this._networkLinkObserver, NS_NETWORK_LINK_TOPIC);
+ this._isNetworkLinkObserverAttached = false;
+ this._networkLinkObserverTimeout = null;
+ }, 5000);
+ }
+ }
+
+ startDiscovery(aServiceType, aListener) {
+ DEBUG && debug('startDiscovery("' + aServiceType + '")');
+ let { serviceType } = _parseServiceDomainName(aServiceType);
+
+ this._attachNetworkLinkObserver();
+ this._addServiceListener(serviceType, aListener);
+
+ try {
+ this._query(serviceType + '.local');
+ aListener.onDiscoveryStarted(serviceType);
+ } catch (e) {
+ DEBUG && debug('startDiscovery("' + serviceType + '") FAILED: ' + e);
+ this._removeServiceListener(serviceType, aListener);
+ aListener.onStartDiscoveryFailed(serviceType, Cr.NS_ERROR_FAILURE);
+ }
+ }
+
+ stopDiscovery(aServiceType, aListener) {
+ DEBUG && debug('stopDiscovery("' + aServiceType + '")');
+ let { serviceType } = _parseServiceDomainName(aServiceType);
+
+ this._detachNetworkLinkObserver();
+ this._removeServiceListener(serviceType, aListener);
+
+ aListener.onDiscoveryStopped(serviceType);
+
+ this._checkCloseSockets();
+ }
+
+ resolveService(aServiceInfo, aListener) {
+ DEBUG && debug('resolveService(): ' + aServiceInfo.serviceName);
+
+ // Address info is already resolved during discovery
+ setTimeout(() => aListener.onServiceResolved(aServiceInfo));
+ }
+
+ registerService(aServiceInfo, aListener) {
+ DEBUG && debug('registerService(): ' + aServiceInfo.serviceName);
+
+ // Initialize the broadcast receiver socket in case it
+ // hasn't already been started so we can listen for
+ // multicast queries/announcements on all interfaces.
+ this._getBroadcastReceiverSocket();
+
+ for (let name of ['port', 'serviceName', 'serviceType']) {
+ if (!TryGet(aServiceInfo, name)) {
+ aListener.onRegistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE);
+ throw new Error('Invalid nsIDNSServiceInfo; Missing "' + name + '"');
+ }
+ }
+
+ let publishedService;
+ try {
+ publishedService = new PublishedService(aServiceInfo);
+ } catch (e) {
+ DEBUG && debug("Error constructing PublishedService: " + e + " - " + e.stack);
+ setTimeout(() => aListener.onRegistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+ return;
+ }
+
+ // Ensure such a service does not already exist.
+ if (this._services.get(publishedService.key)) {
+ setTimeout(() => aListener.onRegistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+ return;
+ }
+
+ // Make sure that the service addr is '0.0.0.0', or there is at least one
+ // socket open on the address the service is open on.
+ this._getSockets().then((sockets) => {
+ if (publishedService.address != '0.0.0.0' && !sockets.get(publishedService.address)) {
+ setTimeout(() => aListener.onRegistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+ return;
+ }
+
+ this._services.set(publishedService.key, publishedService);
+
+ // Service registered.. call onServiceRegistered on next tick.
+ setTimeout(() => aListener.onServiceRegistered(aServiceInfo));
+
+ // Set a timeout to start advertising the service too.
+ publishedService.advertiseTimer = setTimeout(() => {
+ this._advertiseService(publishedService.key, /* firstAdv = */ true);
+ });
+ });
+ }
+
+ unregisterService(aServiceInfo, aListener) {
+ DEBUG && debug('unregisterService(): ' + aServiceInfo.serviceName);
+
+ let serviceKey;
+ try {
+ serviceKey = ServiceKey(aServiceInfo);
+ } catch (e) {
+ setTimeout(() => aListener.onUnregistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+ return;
+ }
+
+ let publishedService = this._services.get(serviceKey);
+ if (!publishedService) {
+ setTimeout(() => aListener.onUnregistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+ return;
+ }
+
+ // Clear any advertise timeout for this published service.
+ publishedService.clearAdvertiseTimer();
+
+ // Delete the service from the service map.
+ if (!this._services.delete(serviceKey)) {
+ setTimeout(() => aListener.onUnregistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+ return;
+ }
+
+ // Check the broadcast timer again to rejig when it should run next.
+ this._checkStartBroadcastTimer();
+
+ // Check to see if sockets should be closed, and if so close them.
+ this._checkCloseSockets();
+
+ aListener.onServiceUnregistered(aServiceInfo);
+ }
+
+ _respondToQuery(serviceKey, message) {
+ let address = message.fromAddr.address;
+ let port = message.fromAddr.port;
+ DEBUG && debug('_respondToQuery(): key=' + serviceKey + ', fromAddr='
+ + address + ":" + port);
+
+ let publishedService = this._services.get(serviceKey);
+ if (!publishedService) {
+ debug("_respondToQuery Could not find service (key=" + serviceKey + ")");
+ return;
+ }
+
+ DEBUG && debug('_respondToQuery(): key=' + serviceKey + ': SENDING RESPONSE');
+ this._advertiseServiceHelper(publishedService, {address,port});
+ }
+
+ _advertiseService(serviceKey, firstAdv) {
+ DEBUG && debug('_advertiseService(): key=' + serviceKey);
+ let publishedService = this._services.get(serviceKey);
+ if (!publishedService) {
+ debug("_advertiseService Could not find service to advertise (key=" + serviceKey + ")");
+ return;
+ }
+
+ publishedService.advertiseTimer = undefined;
+
+ this._advertiseServiceHelper(publishedService, null).then(() => {
+ // If first advertisement, re-advertise in 1 second.
+ // Otherwise, set the lastAdvertised time.
+ if (firstAdv) {
+ publishedService.advertiseTimer = setTimeout(() => {
+ this._advertiseService(serviceKey)
+ }, 1000);
+ } else {
+ publishedService.lastAdvertised = Date.now();
+ this._checkStartBroadcastTimer();
+ }
+ });
+ }
+
+ _advertiseServiceHelper(svc, target) {
+ if (!target) {
+ target = {address:MDNS_MULTICAST_GROUP, port:MDNS_PORT};
+ }
+
+ return this._getSockets().then((sockets) => {
+ sockets.forEach((socket, address) => {
+ if (svc.address == "0.0.0.0" || address == svc.address)
+ {
+ let packet = this._makeServicePacket(svc, [address]);
+ let data = packet.serialize();
+ try {
+ socket.send(target.address, target.port, data, data.length);
+ } catch (err) {
+ DEBUG && debug("Failed to send packet to "
+ + target.address + ":" + target.port);
+ }
+ }
+ });
+ });
+ }
+
+ _cancelBroadcastTimer() {
+ if (!this._broadcastTimer) {
+ return;
+ }
+ clearTimeout(this._broadcastTimer);
+ this._broadcastTimer = undefined;
+ }
+
+ _checkStartBroadcastTimer() {
+ DEBUG && debug("_checkStartBroadcastTimer()");
+ // Cancel any existing broadcasting timer.
+ this._cancelBroadcastTimer();
+
+ let now = Date.now();
+
+ // Go through services and find services to broadcast.
+ let bcastServices = [];
+ let nextBcastWait = undefined;
+ for (let [serviceKey, publishedService] of this._services) {
+ // if lastAdvertised is undefined, service hasn't finished it's initial
+ // two broadcasts.
+ if (publishedService.lastAdvertised === undefined) {
+ continue;
+ }
+
+ // Otherwise, check lastAdvertised against now.
+ let msSinceAdv = now - publishedService.lastAdvertised;
+
+ // If msSinceAdv is more than 90% of the way to the TTL, advertise now.
+ if (msSinceAdv > (DEFAULT_TTL * 1000 * 0.9)) {
+ bcastServices.push(publishedService);
+ continue;
+ }
+
+ // Otherwise, calculate the next time to advertise for this service.
+ // We set that at 95% of the time to the TTL expiry.
+ let nextAdvWait = (DEFAULT_TTL * 1000 * 0.95) - msSinceAdv;
+ if (nextBcastWait === undefined || nextBcastWait > nextAdvWait) {
+ nextBcastWait = nextAdvWait;
+ }
+ }
+
+ // Schedule an immediate advertisement of all services to be advertised now.
+ for (let svc of bcastServices) {
+ svc.advertiseTimer = setTimeout(() => this._advertiseService(svc.key));
+ }
+
+ // Schedule next broadcast check for the next bcast time.
+ if (nextBcastWait !== undefined) {
+ DEBUG && debug("_checkStartBroadcastTimer(): Scheduling next check in " + nextBcastWait + "ms");
+ this._broadcastTimer = setTimeout(() => this._checkStartBroadcastTimer(), nextBcastWait);
+ }
+ }
+
+ _query(name) {
+ DEBUG && debug('query("' + name + '")');
+ let packet = new DNSPacket();
+ packet.setFlag('QR', DNS_QUERY_RESPONSE_CODES.QUERY);
+
+ // PTR Record
+ packet.addRecord('QD', new DNSRecord({
+ name: name,
+ recordType: DNS_RECORD_TYPES.PTR,
+ classCode: DNS_CLASS_CODES.IN,
+ cacheFlush: true
+ }));
+
+ let data = packet.serialize();
+
+ // Initialize the broadcast receiver socket in case it
+ // hasn't already been started so we can listen for
+ // multicast queries/announcements on all interfaces.
+ this._getBroadcastReceiverSocket();
+
+ this._getQuerySocket().then((querySocket) => {
+ DEBUG && debug('sending query on query socket ("' + name + '")');
+ querySocket.send(MDNS_MULTICAST_GROUP, MDNS_PORT, data, data.length);
+ });
+
+ // Automatically announce previously-discovered
+ // services that match and haven't expired yet.
+ setTimeout(() => {
+ DEBUG && debug('announcing previously discovered services ("' + name + '")');
+ let { serviceType } = _parseServiceDomainName(name);
+
+ this._clearExpiredDiscoveries();
+ this._discovered.forEach((discovery, key) => {
+ let serviceInfo = discovery.serviceInfo;
+ if (serviceInfo.serviceType !== serviceType) {
+ return;
+ }
+
+ let listeners = this._listeners.get(serviceInfo.serviceType) || [];
+ listeners.forEach((listener) => {
+ listener.onServiceFound(serviceInfo);
+ });
+ });
+ });
+ }
+
+ _clearExpiredDiscoveries() {
+ this._discovered.forEach((discovery, key) => {
+ if (discovery.expireTime < Date.now()) {
+ this._discovered.delete(key);
+ return;
+ }
+ });
+ }
+
+ _handleQueryPacket(packet, message) {
+ packet.getRecords(['QD']).forEach((record) => {
+ // Don't respond if the query's class code is not IN or ANY.
+ if (record.classCode !== DNS_CLASS_CODES.IN &&
+ record.classCode !== DNS_CLASS_CODES.ANY) {
+ return;
+ }
+
+ // Don't respond if the query's record type is not PTR or ANY.
+ if (record.recordType !== DNS_RECORD_TYPES.PTR &&
+ record.recordType !== DNS_RECORD_TYPES.ANY) {
+ return;
+ }
+
+ for (let [serviceKey, publishedService] of this._services) {
+ DEBUG && debug("_handleQueryPacket: " + packet.toJSON());
+ if (publishedService.ptrMatch(record.name)) {
+ this._respondToQuery(serviceKey, message);
+ }
+ }
+ });
+ }
+
+ _makeServicePacket(service, addresses) {
+ let packet = new DNSPacket();
+ packet.setFlag('QR', DNS_QUERY_RESPONSE_CODES.RESPONSE);
+ packet.setFlag('AA', DNS_AUTHORITATIVE_ANSWER_CODES.YES);
+
+ let host = service.host || _hostname;
+
+ // e.g.: foo-bar-service._http._tcp.local
+ let serviceDomainName = service.serviceName + '.' + service.serviceType + '.local';
+
+ // PTR Record
+ packet.addRecord('AN', new DNSResourceRecord({
+ name: service.serviceType + '.local', // e.g.: _http._tcp.local
+ recordType: DNS_RECORD_TYPES.PTR,
+ data: serviceDomainName
+ }));
+
+ // SRV Record
+ packet.addRecord('AR', new DNSResourceRecord({
+ name: serviceDomainName,
+ recordType: DNS_RECORD_TYPES.SRV,
+ classCode: DNS_CLASS_CODES.IN,
+ cacheFlush: true,
+ data: {
+ priority: 0,
+ weight: 0,
+ port: service.port,
+ target: host // e.g.: My-Android-Phone.local
+ }
+ }));
+
+ // A Records
+ for (let address of addresses) {
+ packet.addRecord('AR', new DNSResourceRecord({
+ name: host,
+ recordType: DNS_RECORD_TYPES.A,
+ data: address
+ }));
+ }
+
+ // TXT Record
+ packet.addRecord('AR', new DNSResourceRecord({
+ name: serviceDomainName,
+ recordType: DNS_RECORD_TYPES.TXT,
+ classCode: DNS_CLASS_CODES.IN,
+ cacheFlush: true,
+ data: service.serviceAttrs || {}
+ }));
+
+ return packet;
+ }
+
+ _handleResponsePacket(packet, message) {
+ let services = {};
+ let hosts = {};
+
+ let srvRecords = packet.getRecords(['AN', 'AR'], DNS_RECORD_TYPES.SRV);
+ let txtRecords = packet.getRecords(['AN', 'AR'], DNS_RECORD_TYPES.TXT);
+ let ptrRecords = packet.getRecords(['AN', 'AR'], DNS_RECORD_TYPES.PTR);
+ let aRecords = packet.getRecords(['AN', 'AR'], DNS_RECORD_TYPES.A);
+
+ srvRecords.forEach((record) => {
+ let data = record.data || {};
+
+ services[record.name] = {
+ host: data.target,
+ port: data.port,
+ ttl: record.ttl
+ };
+ });
+
+ txtRecords.forEach((record) => {
+ if (!services[record.name]) {
+ return;
+ }
+
+ services[record.name].attributes = record.data;
+ });
+
+ aRecords.forEach((record) => {
+ if (IsIpv4Address(record.data)) {
+ hosts[record.name] = record.data;
+ }
+ });
+
+ ptrRecords.forEach((record) => {
+ let name = record.data;
+ if (!services[name]) {
+ return;
+ }
+
+ let {host, port} = services[name];
+ if (!host || !port) {
+ return;
+ }
+
+ let { serviceName, serviceType, domainName } = _parseServiceDomainName(name);
+ if (!serviceName || !serviceType || !domainName) {
+ return;
+ }
+
+ let address = hosts[host];
+ if (!address) {
+ return;
+ }
+
+ let ttl = services[name].ttl || 0;
+ let serviceInfo = {
+ serviceName: serviceName,
+ serviceType: serviceType,
+ host: host,
+ address: address,
+ port: port,
+ domainName: domainName,
+ attributes: services[name].attributes || {}
+ };
+
+ this._onServiceFound(serviceInfo, ttl);
+ });
+ }
+
+ _onServiceFound(serviceInfo, ttl = 0) {
+ let expireTime = Date.now() + (ttl * 1000);
+ let key = serviceInfo.serviceName + '.' +
+ serviceInfo.serviceType + '.' +
+ serviceInfo.domainName + ' @' +
+ serviceInfo.address + ':' +
+ serviceInfo.port;
+
+ // If this service was already discovered, just update
+ // its expiration time and don't re-emit it.
+ if (this._discovered.has(key)) {
+ this._discovered.get(key).expireTime = expireTime;
+ return;
+ }
+
+ this._discovered.set(key, {
+ serviceInfo: serviceInfo,
+ expireTime: expireTime
+ });
+
+ let listeners = this._listeners.get(serviceInfo.serviceType) || [];
+ listeners.forEach((listener) => {
+ listener.onServiceFound(serviceInfo);
+ });
+
+ DEBUG && debug('_onServiceFound()' + serviceInfo.serviceName);
+ }
+
+ /**
+ * Gets a non-exclusive socket on 0.0.0.0:{random} to send
+ * multicast queries on all interfaces. This socket does
+ * not need to join a multicast group since it is still
+ * able to *send* multicast queries, but it does not need
+ * to *listen* for multicast queries/announcements since
+ * the `_broadcastReceiverSocket` is already handling them.
+ */
+ _getQuerySocket() {
+ return new Promise((resolve, reject) => {
+ if (!this._querySocket) {
+ this._querySocket = _openSocket('0.0.0.0', 0, {
+ onPacketReceived: this._onPacketReceived.bind(this),
+ onStopListening: this._onStopListening.bind(this)
+ });
+ }
+ resolve(this._querySocket);
+ });
+ }
+
+ /**
+ * Gets a non-exclusive socket on 0.0.0.0:5353 to listen
+ * for multicast queries/announcements on all interfaces.
+ * Since this socket needs to listen for multicast queries
+ * and announcements, this socket joins the multicast
+ * group on *all* interfaces (0.0.0.0).
+ */
+ _getBroadcastReceiverSocket() {
+ return new Promise((resolve, reject) => {
+ if (!this._broadcastReceiverSocket) {
+ this._broadcastReceiverSocket = _openSocket('0.0.0.0', MDNS_PORT, {
+ onPacketReceived: this._onPacketReceived.bind(this),
+ onStopListening: this._onStopListening.bind(this)
+ }, /* multicastInterface = */ '0.0.0.0');
+ }
+ resolve(this._broadcastReceiverSocket);
+ });
+ }
+
+ /**
+ * Gets a non-exclusive socket for each interface on
+ * {iface-ip}:5353 for sending query responses as
+ * well as for listening for unicast queries. These
+ * sockets do not need to join a multicast group
+ * since they are still able to *send* multicast
+ * query responses, but they do not need to *listen*
+ * for multicast queries since the `_querySocket` is
+ * already handling them.
+ */
+ _getSockets() {
+ return new Promise((resolve) => {
+ if (this._sockets.size > 0) {
+ resolve(this._sockets);
+ return;
+ }
+
+ Promise.all([getAddresses(), getHostname()]).then(() => {
+ _addresses.forEach((address) => {
+ let socket = _openSocket(address, MDNS_PORT, null);
+ this._sockets.set(address, socket);
+ });
+
+ resolve(this._sockets);
+ });
+ });
+ }
+
+ _checkCloseSockets() {
+ // Nothing to do if no sockets to close.
+ if (this._sockets.size == 0)
+ return;
+
+ // Don't close sockets if discovery listeners are still present.
+ if (this._listeners.size > 0)
+ return;
+
+ // Don't close sockets if advertised services are present.
+ // Since we need to listen for service queries and respond to them.
+ if (this._services.size > 0)
+ return;
+
+ this._closeSockets();
+ }
+
+ _closeSockets() {
+ this._sockets.forEach(socket => socket.close());
+ this._sockets.clear();
+ }
+
+ _onPacketReceived(socket, message) {
+ let packet = DNSPacket.parse(message.rawData);
+
+ switch (packet.getFlag('QR')) {
+ case DNS_QUERY_RESPONSE_CODES.QUERY:
+ this._handleQueryPacket(packet, message);
+ break;
+ case DNS_QUERY_RESPONSE_CODES.RESPONSE:
+ this._handleResponsePacket(packet, message);
+ break;
+ default:
+ break;
+ }
+ }
+
+ _onStopListening(socket, status) {
+ DEBUG && debug('_onStopListening() ' + status);
+ }
+
+ _addServiceListener(serviceType, listener) {
+ let listeners = this._listeners.get(serviceType);
+ if (!listeners) {
+ listeners = [];
+ this._listeners.set(serviceType, listeners);
+ }
+
+ if (!listeners.find(l => l === listener)) {
+ listeners.push(listener);
+ }
+ }
+
+ _removeServiceListener(serviceType, listener) {
+ let listeners = this._listeners.get(serviceType);
+ if (!listeners) {
+ return;
+ }
+
+ let index = listeners.findIndex(l => l === listener);
+ if (index >= 0) {
+ listeners.splice(index, 1);
+ }
+
+ if (listeners.length === 0) {
+ this._listeners.delete(serviceType);
+ }
+ }
+}
+
+let _addresses;
+
+/**
+ * @private
+ */
+function getAddresses() {
+ return new Promise((resolve, reject) => {
+ if (_addresses) {
+ resolve(_addresses);
+ return;
+ }
+
+ networkInfoService.listNetworkAddresses({
+ onListedNetworkAddresses(aAddressArray) {
+ _addresses = aAddressArray.filter((address) => {
+ return address.indexOf('%p2p') === -1 && // No WiFi Direct interfaces
+ address.indexOf(':') === -1 && // XXX: No IPv6 for now
+ address != "127.0.0.1" // No ipv4 loopback addresses.
+ });
+
+ DEBUG && debug('getAddresses(): ' + _addresses);
+ resolve(_addresses);
+ },
+
+ onListNetworkAddressesFailed() {
+ DEBUG && debug('getAddresses() FAILED!');
+ resolve([]);
+ }
+ });
+ });
+}
+
+let _hostname;
+
+/**
+ * @private
+ */
+function getHostname() {
+ return new Promise((resolve) => {
+ if (_hostname) {
+ resolve(_hostname);
+ return;
+ }
+
+ networkInfoService.getHostname({
+ onGotHostname(aHostname) {
+ _hostname = aHostname.replace(/\s/g, '-') + '.local';
+
+ DEBUG && debug('getHostname(): ' + _hostname);
+ resolve(_hostname);
+ },
+
+ onGetHostnameFailed() {
+ DEBUG && debug('getHostname() FAILED');
+ resolve('localhost');
+ }
+ });
+ });
+}
+
+/**
+ * Parse fully qualified domain name to service name, instance name,
+ * and domain name. See https://tools.ietf.org/html/rfc6763#section-7.
+ *
+ * Example: 'foo-bar-service._http._tcp.local' -> {
+ * serviceName: 'foo-bar-service',
+ * serviceType: '_http._tcp',
+ * domainName: 'local'
+ * }
+ *
+ * @private
+ */
+function _parseServiceDomainName(serviceDomainName) {
+ let parts = serviceDomainName.split('.');
+ let index = Math.max(parts.lastIndexOf('_tcp'), parts.lastIndexOf('_udp'));
+
+ return {
+ serviceName: parts.splice(0, index - 1).join('.'),
+ serviceType: parts.splice(0, 2).join('.'),
+ domainName: parts.join('.')
+ };
+}
+
+/**
+ * @private
+ */
+function _propertyBagToObject(propBag) {
+ let result = {};
+ if (propBag.QueryInterface) {
+ propBag.QueryInterface(Ci.nsIPropertyBag2);
+ let propEnum = propBag.enumerator;
+ while (propEnum.hasMoreElements()) {
+ let prop = propEnum.getNext().QueryInterface(Ci.nsIProperty);
+ result[prop.name] = prop.value.toString();
+ }
+ } else {
+ for (let name in propBag) {
+ result[name] = propBag[name].toString();
+ }
+ }
+ return result;
+}
+
+/**
+ * @private
+ */
+function _openSocket(addr, port, handler, multicastInterface) {
+ let socket = Cc['@mozilla.org/network/udp-socket;1'].createInstance(Ci.nsIUDPSocket);
+ socket.init2(addr, port, Services.scriptSecurityManager.getSystemPrincipal(), true);
+
+ if (handler) {
+ socket.asyncListen({
+ onPacketReceived: handler.onPacketReceived,
+ onStopListening: handler.onStopListening
+ });
+ }
+
+ if (multicastInterface) {
+ socket.joinMulticast(MDNS_MULTICAST_GROUP, multicastInterface);
+ }
+
+ return socket;
+}