1 files changed, 477 insertions, 0 deletions
diff --git a/toolkit/modules/secondscreen/SimpleServiceDiscovery.jsm b/toolkit/modules/secondscreen/SimpleServiceDiscovery.jsm
new file mode 100644
index 0000000000..a4df15e8c5
--- /dev/null
+++ b/toolkit/modules/secondscreen/SimpleServiceDiscovery.jsm
@@ -0,0 +1,477 @@
+// -*- Mode: js; tab-width: 2; indent-tabs-mode: nil; js2-basic-offset: 2; js2-skip-preprocessor-directives: t; -*-
+/* 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/. */
+
+"use strict";
+
+var EXPORTED_SYMBOLS = ["SimpleServiceDiscovery"];
+
+const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
+const { XPCOMUtils } = ChromeUtils.import(
+  "resource://gre/modules/XPCOMUtils.jsm"
+);
+const { setTimeout } = ChromeUtils.import("resource://gre/modules/Timer.jsm");
+
+var log = Cu.reportError;
+XPCOMUtils.defineLazyGlobalGetters(this, ["XMLHttpRequest"]);
+
+XPCOMUtils.defineLazyGetter(this, "converter", function() {
+  let conv = Cc["@mozilla.org/intl/scriptableunicodeconverter"].createInstance(
+    Ci.nsIScriptableUnicodeConverter
+  );
+  conv.charset = "utf8";
+  return conv;
+});
+
+// Spec information:
+// https://tools.ietf.org/html/draft-cai-ssdp-v1-03
+// http://www.dial-multiscreen.org/dial-protocol-specification
+const SSDP_PORT = 1900;
+const SSDP_ADDRESS = "239.255.255.250";
+
+const SSDP_DISCOVER_PACKET =
+  "M-SEARCH * HTTP/1.1\r\n" +
+  "HOST: " +
+  SSDP_ADDRESS +
+  ":" +
+  SSDP_PORT +
+  "\r\n" +
+  'MAN: "ssdp:discover"\r\n' +
+  "MX: 2\r\n" +
+  "ST: %SEARCH_TARGET%\r\n\r\n";
+
+const SSDP_DISCOVER_ATTEMPTS = 3;
+const SSDP_DISCOVER_DELAY = 500;
+const SSDP_DISCOVER_TIMEOUT_MULTIPLIER = 2;
+const SSDP_TRANSMISSION_INTERVAL = 1000;
+
+const EVENT_SERVICE_FOUND = "ssdp-service-found";
+const EVENT_SERVICE_LOST = "ssdp-service-lost";
+
+/*
+ * SimpleServiceDiscovery manages any discovered SSDP services. It uses a UDP
+ * broadcast to locate available services on the local network.
+ */
+var SimpleServiceDiscovery = {
+  get EVENT_SERVICE_FOUND() {
+    return EVENT_SERVICE_FOUND;
+  },
+  get EVENT_SERVICE_LOST() {
+    return EVENT_SERVICE_LOST;
+  },
+
+  _devices: new Map(),
+  _services: new Map(),
+  _searchSocket: null,
+  _searchInterval: 0,
+  _searchTimestamp: 0,
+  _searchTimeout: Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer),
+  _searchRepeat: Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer),
+  _discoveryMethods: [],
+
+  _forceTrailingSlash(aURL) {
+    // Cleanup the URL to make it consistent across devices
+    try {
+      aURL = Services.io.newURI(aURL).spec;
+    } catch (e) {}
+    return aURL;
+  },
+
+  // nsIUDPSocketListener implementation
+  onPacketReceived(aSocket, aMessage) {
+    // Listen for responses from specific devices. There could be more than one
+    // available.
+    let response = aMessage.data.split("\n");
+    let service = {};
+    response.forEach(function(row) {
+      let name = row.toUpperCase();
+      if (name.startsWith("LOCATION")) {
+        service.location = row.substr(10).trim();
+      } else if (name.startsWith("ST")) {
+        service.target = row.substr(4).trim();
+      }
+    });
+
+    if (service.location && service.target) {
+      service.location = this._forceTrailingSlash(service.location);
+
+      // When we find a valid response, package up the service information
+      // and pass it on.
+      try {
+        this._processService(service);
+      } catch (e) {}
+    }
+  },
+
+  onStopListening(aSocket, aStatus) {
+    // This is fired when the socket is closed expectedly or unexpectedly.
+    // nsITimer.cancel() is a no-op if the timer is not active.
+    this._searchTimeout.cancel();
+    this._searchSocket = null;
+  },
+
+  // Start a search. Make it continuous by passing an interval (in milliseconds).
+  // This will stop a current search loop because the timer resets itself.
+  // Returns the existing search interval.
+  search: function search(aInterval) {
+    let existingSearchInterval = this._searchInterval;
+    if (aInterval > 0) {
+      this._searchInterval = aInterval || 0;
+      this._searchRepeat.initWithCallback(
+        this._search.bind(this),
+        this._searchInterval,
+        Ci.nsITimer.TYPE_REPEATING_SLACK
+      );
+    }
+    this._search();
+    return existingSearchInterval;
+  },
+
+  // Stop the current continuous search
+  stopSearch: function stopSearch() {
+    this._searchRepeat.cancel();
+  },
+
+  _usingLAN() {
+    let network = Cc["@mozilla.org/network/network-link-service;1"].getService(
+      Ci.nsINetworkLinkService
+    );
+    return (
+      network.linkType == Ci.nsINetworkLinkService.LINK_TYPE_WIFI ||
+      network.linkType == Ci.nsINetworkLinkService.LINK_TYPE_ETHERNET ||
+      network.linkType == Ci.nsINetworkLinkService.LINK_TYPE_UNKNOWN
+    );
+  },
+
+  _search: function _search() {
+    // If a search is already active, shut it down.
+    this._searchShutdown();
+
+    // We only search if on local network
+    if (!this._usingLAN()) {
+      return;
+    }
+
+    // Update the timestamp so we can use it to clean out stale services the
+    // next time we search.
+    this._searchTimestamp = Date.now();
+
+    // Look for any fixed IP devices. Some routers might be configured to block
+    // UDP broadcasts, so this is a way to skip discovery.
+    this._searchFixedDevices();
+
+    // Look for any devices via registered external discovery mechanism.
+    this._startExternalDiscovery();
+
+    // Perform a UDP broadcast to search for SSDP devices
+    let socket = Cc["@mozilla.org/network/udp-socket;1"].createInstance(
+      Ci.nsIUDPSocket
+    );
+    try {
+      socket.init(
+        SSDP_PORT,
+        false,
+        Services.scriptSecurityManager.getSystemPrincipal()
+      );
+      socket.joinMulticast(SSDP_ADDRESS);
+      socket.asyncListen(this);
+    } catch (e) {
+      // We were unable to create the broadcast socket. Just return, but don't
+      // kill the interval timer. This might work next time.
+      log("failed to start socket: " + e);
+      return;
+    }
+
+    // Make the timeout SSDP_DISCOVER_TIMEOUT_MULTIPLIER times as long as the time needed to send out the discovery packets.
+    const SSDP_DISCOVER_TIMEOUT =
+      this._devices.size *
+      SSDP_DISCOVER_ATTEMPTS *
+      SSDP_TRANSMISSION_INTERVAL *
+      SSDP_DISCOVER_TIMEOUT_MULTIPLIER;
+    this._searchSocket = socket;
+    this._searchTimeout.initWithCallback(
+      this._searchShutdown.bind(this),
+      SSDP_DISCOVER_TIMEOUT,
+      Ci.nsITimer.TYPE_ONE_SHOT
+    );
+
+    let data = SSDP_DISCOVER_PACKET;
+
+    // Send discovery packets out at 1 per SSDP_TRANSMISSION_INTERVAL and send each SSDP_DISCOVER_ATTEMPTS times
+    // to allow for packet loss on noisy networks.
+    let timeout = SSDP_DISCOVER_DELAY;
+    for (let attempts = 0; attempts < SSDP_DISCOVER_ATTEMPTS; attempts++) {
+      for (let [, /* key */ device] of this._devices) {
+        let target = device.target;
+        setTimeout(function() {
+          let msgData = data.replace("%SEARCH_TARGET%", target);
+          try {
+            let msgRaw = converter.convertToByteArray(msgData);
+            socket.send(SSDP_ADDRESS, SSDP_PORT, msgRaw);
+          } catch (e) {
+            log("failed to convert to byte array: " + e);
+          }
+        }, timeout);
+        timeout += SSDP_TRANSMISSION_INTERVAL;
+      }
+    }
+  },
+
+  _searchFixedDevices: function _searchFixedDevices() {
+    let fixedDevices = Services.prefs.getCharPref(
+      "browser.casting.fixedDevices",
+      ""
+    );
+
+    if (!fixedDevices) {
+      return;
+    }
+
+    fixedDevices = JSON.parse(fixedDevices);
+    for (let fixedDevice of fixedDevices) {
+      // Verify we have the right data
+      if (!("location" in fixedDevice) || !("target" in fixedDevice)) {
+        continue;
+      }
+
+      fixedDevice.location = this._forceTrailingSlash(fixedDevice.location);
+
+      let service = {
+        location: fixedDevice.location,
+        target: fixedDevice.target,
+      };
+
+      // We don't assume the fixed target is ready. We still need to ping it.
+      try {
+        this._processService(service);
+      } catch (e) {}
+    }
+  },
+
+  // Called when the search timeout is hit. We use it to cleanup the socket and
+  // perform some post-processing on the services list.
+  _searchShutdown: function _searchShutdown() {
+    if (this._searchSocket) {
+      // This will call onStopListening.
+      this._searchSocket.close();
+
+      // Clean out any stale services
+      for (let [, /* key */ service] of this._services) {
+        if (service.lastPing != this._searchTimestamp) {
+          this.removeService(service.uuid);
+        }
+      }
+    }
+
+    this._stopExternalDiscovery();
+  },
+
+  getSupportedExtensions() {
+    let extensions = [];
+    this.services.forEach(function(service) {
+      extensions = extensions.concat(service.extensions);
+    }, this);
+    return extensions.filter(function(extension, pos) {
+      return extensions.indexOf(extension) == pos;
+    });
+  },
+
+  getSupportedMimeTypes() {
+    let types = [];
+    this.services.forEach(function(service) {
+      types = types.concat(service.types);
+    }, this);
+    return types.filter(function(type, pos) {
+      return types.indexOf(type) == pos;
+    });
+  },
+
+  registerDevice: function registerDevice(aDevice) {
+    // We must have "id", "target" and "factory" defined
+    if (
+      !("id" in aDevice) ||
+      !("target" in aDevice) ||
+      !("factory" in aDevice)
+    ) {
+      // Fatal for registration
+      throw new Error("Registration requires an id, a target and a location");
+    }
+
+    // Only add if we don't already know about this device
+    if (!this._devices.has(aDevice.id)) {
+      this._devices.set(aDevice.id, aDevice);
+    } else {
+      log("device was already registered: " + aDevice.id);
+    }
+  },
+
+  unregisterDevice: function unregisterDevice(aDevice) {
+    // We must have "id", "target" and "factory" defined
+    if (
+      !("id" in aDevice) ||
+      !("target" in aDevice) ||
+      !("factory" in aDevice)
+    ) {
+      return;
+    }
+
+    // Only remove if we know about this device
+    if (this._devices.has(aDevice.id)) {
+      this._devices.delete(aDevice.id);
+    } else {
+      log("device was not registered: " + aDevice.id);
+    }
+  },
+
+  findAppForService: function findAppForService(aService) {
+    if (!aService || !aService.deviceID) {
+      return null;
+    }
+
+    // Find the registration for the device
+    if (this._devices.has(aService.deviceID)) {
+      return this._devices.get(aService.deviceID).factory(aService);
+    }
+    return null;
+  },
+
+  findServiceForID: function findServiceForID(aUUID) {
+    if (this._services.has(aUUID)) {
+      return this._services.get(aUUID);
+    }
+    return null;
+  },
+
+  // Returns an array copy of the active services
+  get services() {
+    let array = [];
+    for (let [, /* key */ service] of this._services) {
+      let target = this._devices.get(service.deviceID);
+      service.extensions = target.extensions;
+      service.types = target.types;
+      array.push(service);
+    }
+    return array;
+  },
+
+  // Returns false if the service does not match the device's filters
+  _filterService: function _filterService(aService) {
+    // Loop over all the devices, looking for one that matches the service
+    for (let [, /* key */ device] of this._devices) {
+      // First level of match is on the target itself
+      if (device.target != aService.target) {
+        continue;
+      }
+
+      // If we have no filter, everything passes
+      if (!("filters" in device)) {
+        aService.deviceID = device.id;
+        return true;
+      }
+
+      // If all the filters pass, we have a match
+      let failed = false;
+      let filters = device.filters;
+      for (let filter in filters) {
+        if (filter in aService && aService[filter] != filters[filter]) {
+          failed = true;
+        }
+      }
+
+      // We found a match, so link the service to the device
+      if (!failed) {
+        aService.deviceID = device.id;
+        return true;
+      }
+    }
+
+    // We didn't find any matches
+    return false;
+  },
+
+  _processService: function _processService(aService) {
+    // Use the REST api to request more information about this service
+    let xhr = new XMLHttpRequest();
+    xhr.open("GET", aService.location, true);
+    xhr.channel.loadFlags |= Ci.nsIRequest.INHIBIT_CACHING;
+    xhr.overrideMimeType("text/xml");
+
+    xhr.addEventListener("load", () => {
+      if (xhr.status == 200) {
+        let doc = xhr.responseXML;
+        aService.appsURL = xhr.getResponseHeader("Application-URL");
+        if (aService.appsURL && !aService.appsURL.endsWith("/")) {
+          aService.appsURL += "/";
+        }
+        aService.friendlyName = doc.querySelector("friendlyName").textContent;
+        aService.uuid = doc.querySelector("UDN").textContent;
+        aService.manufacturer = doc.querySelector("manufacturer").textContent;
+        aService.modelName = doc.querySelector("modelName").textContent;
+
+        this.addService(aService);
+      }
+    });
+
+    xhr.send(null);
+  },
+
+  // Add a service to the WeakMap, even if one already exists with this id.
+  // Returns true if this succeeded or false if it failed
+  _addService(service) {
+    // Filter out services that do not match the device filter
+    if (!this._filterService(service)) {
+      return false;
+    }
+
+    let device = this._devices.get(service.target);
+    if (device && device.mirror) {
+      service.mirror = true;
+    }
+    this._services.set(service.uuid, service);
+    return true;
+  },
+
+  addService(service) {
+    // Only add and notify if we don't already know about this service
+    if (!this._services.has(service.uuid)) {
+      if (!this._addService(service)) {
+        return;
+      }
+      Services.obs.notifyObservers(null, EVENT_SERVICE_FOUND, service.uuid);
+    }
+
+    // Make sure we remember this service is not stale
+    this._services.get(service.uuid).lastPing = this._searchTimestamp;
+  },
+
+  removeService(uuid) {
+    Services.obs.notifyObservers(null, EVENT_SERVICE_LOST, uuid);
+    this._services.delete(uuid);
+  },
+
+  updateService(service) {
+    if (!this._addService(service)) {
+      return;
+    }
+
+    // Make sure we remember this service is not stale
+    this._services.get(service.uuid).lastPing = this._searchTimestamp;
+  },
+
+  addExternalDiscovery(discovery) {
+    this._discoveryMethods.push(discovery);
+  },
+
+  _startExternalDiscovery() {
+    for (let discovery of this._discoveryMethods) {
+      discovery.startDiscovery();
+    }
+  },
+
+  _stopExternalDiscovery() {
+    for (let discovery of this._discoveryMethods) {
+      discovery.stopDiscovery();
+    }
+  },
+};