Add m-esr52 at 52.6.0

1 files changed, 1145 insertions, 0 deletions

diff --git a/dom/push/PushServiceWebSocket.jsm b/dom/push/PushServiceWebSocket.jsm
new file mode 100644
index 0000000000..46b12b8f07
--- /dev/null
+++ b/dom/push/PushServiceWebSocket.jsm
@@ -0,0 +1,1145 @@
+/* jshint moz: true, esnext: true */
+/* 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";
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+const Cr = Components.results;
+
+Cu.import("resource://gre/modules/AppConstants.jsm");
+Cu.import("resource://gre/modules/Preferences.jsm");
+Cu.import("resource://gre/modules/Promise.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/Timer.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+const {PushDB} = Cu.import("resource://gre/modules/PushDB.jsm");
+const {PushRecord} = Cu.import("resource://gre/modules/PushRecord.jsm");
+const {PushCrypto} = Cu.import("resource://gre/modules/PushCrypto.jsm");
+
+const kPUSHWSDB_DB_NAME = "pushapi";
+const kPUSHWSDB_DB_VERSION = 5; // Change this if the IndexedDB format changes
+const kPUSHWSDB_STORE_NAME = "pushapi";
+
+// WebSocket close code sent by the server to indicate that the client should
+// not automatically reconnect.
+const kBACKOFF_WS_STATUS_CODE = 4774;
+
+// Maps ack statuses, unsubscribe reasons, and delivery error reasons to codes
+// included in request payloads.
+const kACK_STATUS_TO_CODE = {
+  [Ci.nsIPushErrorReporter.ACK_DELIVERED]: 100,
+  [Ci.nsIPushErrorReporter.ACK_DECRYPTION_ERROR]: 101,
+  [Ci.nsIPushErrorReporter.ACK_NOT_DELIVERED]: 102,
+};
+
+const kUNREGISTER_REASON_TO_CODE = {
+  [Ci.nsIPushErrorReporter.UNSUBSCRIBE_MANUAL]: 200,
+  [Ci.nsIPushErrorReporter.UNSUBSCRIBE_QUOTA_EXCEEDED]: 201,
+  [Ci.nsIPushErrorReporter.UNSUBSCRIBE_PERMISSION_REVOKED]: 202,
+};
+
+const kDELIVERY_REASON_TO_CODE = {
+  [Ci.nsIPushErrorReporter.DELIVERY_UNCAUGHT_EXCEPTION]: 301,
+  [Ci.nsIPushErrorReporter.DELIVERY_UNHANDLED_REJECTION]: 302,
+  [Ci.nsIPushErrorReporter.DELIVERY_INTERNAL_ERROR]: 303,
+};
+
+const prefs = new Preferences("dom.push.");
+
+this.EXPORTED_SYMBOLS = ["PushServiceWebSocket"];
+
+XPCOMUtils.defineLazyGetter(this, "console", () => {
+  let {ConsoleAPI} = Cu.import("resource://gre/modules/Console.jsm", {});
+  return new ConsoleAPI({
+    maxLogLevelPref: "dom.push.loglevel",
+    prefix: "PushServiceWebSocket",
+  });
+});
+
+/**
+ * A proxy between the PushService and the WebSocket. The listener is used so
+ * that the PushService can silence messages from the WebSocket by setting
+ * PushWebSocketListener._pushService to null. This is required because
+ * a WebSocket can continue to send messages or errors after it has been
+ * closed but the PushService may not be interested in these. It's easier to
+ * stop listening than to have checks at specific points.
+ */
+var PushWebSocketListener = function(pushService) {
+  this._pushService = pushService;
+};
+
+PushWebSocketListener.prototype = {
+  onStart: function(context) {
+    if (!this._pushService) {
+        return;
+    }
+    this._pushService._wsOnStart(context);
+  },
+
+  onStop: function(context, statusCode) {
+    if (!this._pushService) {
+        return;
+    }
+    this._pushService._wsOnStop(context, statusCode);
+  },
+
+  onAcknowledge: function(context, size) {
+    // EMPTY
+  },
+
+  onBinaryMessageAvailable: function(context, message) {
+    // EMPTY
+  },
+
+  onMessageAvailable: function(context, message) {
+    if (!this._pushService) {
+        return;
+    }
+    this._pushService._wsOnMessageAvailable(context, message);
+  },
+
+  onServerClose: function(context, aStatusCode, aReason) {
+    if (!this._pushService) {
+        return;
+    }
+    this._pushService._wsOnServerClose(context, aStatusCode, aReason);
+  }
+};
+
+// websocket states
+// websocket is off
+const STATE_SHUT_DOWN = 0;
+// Websocket has been opened on client side, waiting for successful open.
+// (_wsOnStart)
+const STATE_WAITING_FOR_WS_START = 1;
+// Websocket opened, hello sent, waiting for server reply (_handleHelloReply).
+const STATE_WAITING_FOR_HELLO = 2;
+// Websocket operational, handshake completed, begin protocol messaging.
+const STATE_READY = 3;
+
+this.PushServiceWebSocket = {
+  _mainPushService: null,
+  _serverURI: null,
+
+  newPushDB: function() {
+    return new PushDB(kPUSHWSDB_DB_NAME,
+                      kPUSHWSDB_DB_VERSION,
+                      kPUSHWSDB_STORE_NAME,
+                      "channelID",
+                      PushRecordWebSocket);
+  },
+
+  disconnect: function() {
+    this._shutdownWS();
+  },
+
+  observe: function(aSubject, aTopic, aData) {
+    if (aTopic == "nsPref:changed" && aData == "dom.push.userAgentID") {
+      this._onUAIDChanged();
+    } else if (aTopic == "timer-callback") {
+      this._onTimerFired(aSubject);
+    }
+  },
+
+  /**
+   * Handles a UAID change. Unlike reconnects, we cancel all pending requests
+   * after disconnecting. Existing subscriptions stored in IndexedDB will be
+   * dropped on reconnect.
+   */
+  _onUAIDChanged() {
+    console.debug("onUAIDChanged()");
+
+    this._shutdownWS();
+    this._startBackoffTimer();
+  },
+
+  /** Handles a ping, backoff, or request timeout timer event. */
+  _onTimerFired(timer) {
+    console.debug("onTimerFired()");
+
+    if (timer == this._pingTimer) {
+      this._sendPing();
+      return;
+    }
+
+    if (timer == this._backoffTimer) {
+      console.debug("onTimerFired: Reconnecting after backoff");
+      this._beginWSSetup();
+      return;
+    }
+
+    if (timer == this._requestTimeoutTimer) {
+      this._timeOutRequests();
+      return;
+    }
+  },
+
+  /**
+   * Sends a ping to the server. Bypasses the request queue, but starts the
+   * request timeout timer. If the socket is already closed, or the server
+   * does not respond within the timeout, the client will reconnect.
+   */
+  _sendPing() {
+    console.debug("sendPing()");
+
+    this._startRequestTimeoutTimer();
+    try {
+      this._wsSendMessage({});
+      this._lastPingTime = Date.now();
+    } catch (e) {
+      console.debug("sendPing: Error sending ping", e);
+      this._reconnect();
+    }
+  },
+
+  /** Times out any pending requests. */
+  _timeOutRequests() {
+    console.debug("timeOutRequests()");
+
+    if (!this._hasPendingRequests()) {
+      // Cancel the repeating timer and exit early if we aren't waiting for
+      // pongs or requests.
+      this._requestTimeoutTimer.cancel();
+      return;
+    }
+
+    let now = Date.now();
+
+    // Set to true if at least one request timed out, or we're still waiting
+    // for a pong after the request timeout.
+    let requestTimedOut = false;
+
+    if (this._lastPingTime > 0 &&
+        now - this._lastPingTime > this._requestTimeout) {
+
+      console.debug("timeOutRequests: Did not receive pong in time");
+      requestTimedOut = true;
+
+    } else {
+      for (let [key, request] of this._pendingRequests) {
+        let duration = now - request.ctime;
+        // If any of the registration requests time out, all the ones after it
+        // also made to fail, since we are going to be disconnecting the
+        // socket.
+        requestTimedOut |= duration > this._requestTimeout;
+        if (requestTimedOut) {
+          request.reject(new Error("Request timed out: " + key));
+          this._pendingRequests.delete(key);
+        }
+      }
+    }
+
+    // The most likely reason for a pong or registration request timing out is
+    // that the socket has disconnected. Best to reconnect.
+    if (requestTimedOut) {
+      this._reconnect();
+    }
+  },
+
+  validServerURI: function(serverURI) {
+    if (serverURI.scheme == "ws") {
+      return !!prefs.get("testing.allowInsecureServerURL");
+    }
+    return serverURI.scheme == "wss";
+  },
+
+  get _UAID() {
+    return prefs.get("userAgentID");
+  },
+
+  set _UAID(newID) {
+    if (typeof(newID) !== "string") {
+      console.warn("Got invalid, non-string UAID", newID,
+        "Not updating userAgentID");
+      return;
+    }
+    console.debug("New _UAID", newID);
+    prefs.set("userAgentID", newID);
+  },
+
+  _ws: null,
+  _pendingRequests: new Map(),
+  _currentState: STATE_SHUT_DOWN,
+  _requestTimeout: 0,
+  _requestTimeoutTimer: null,
+  _retryFailCount: 0,
+
+  /**
+   * According to the WS spec, servers should immediately close the underlying
+   * TCP connection after they close a WebSocket. This causes wsOnStop to be
+   * called with error NS_BASE_STREAM_CLOSED. Since the client has to keep the
+   * WebSocket up, it should try to reconnect. But if the server closes the
+   * WebSocket because it wants the client to back off, then the client
+   * shouldn't re-establish the connection. If the server sends the backoff
+   * close code, this field will be set to true in wsOnServerClose. It is
+   * checked in wsOnStop.
+   */
+  _skipReconnect: false,
+
+  /** Indicates whether the server supports Web Push-style message delivery. */
+  _dataEnabled: false,
+
+  /**
+   * The last time the client sent a ping to the server. If non-zero, keeps the
+   * request timeout timer active. Reset to zero when the server responds with
+   * a pong or pending messages.
+   */
+  _lastPingTime: 0,
+
+  /**
+   * A one-shot timer used to ping the server, to avoid timing out idle
+   * connections. Reset to the ping interval on each incoming message.
+   */
+  _pingTimer: null,
+
+  /** A one-shot timer fired after the reconnect backoff period. */
+  _backoffTimer: null,
+
+  /**
+   * Sends a message to the Push Server through an open websocket.
+   * typeof(msg) shall be an object
+   */
+  _wsSendMessage: function(msg) {
+    if (!this._ws) {
+      console.warn("wsSendMessage: No WebSocket initialized.",
+        "Cannot send a message");
+      return;
+    }
+    msg = JSON.stringify(msg);
+    console.debug("wsSendMessage: Sending message", msg);
+    this._ws.sendMsg(msg);
+  },
+
+  init: function(options, mainPushService, serverURI) {
+    console.debug("init()");
+
+    this._mainPushService = mainPushService;
+    this._serverURI = serverURI;
+
+    // Override the default WebSocket factory function. The returned object
+    // must be null or satisfy the nsIWebSocketChannel interface. Used by
+    // the tests to provide a mock WebSocket implementation.
+    if (options.makeWebSocket) {
+      this._makeWebSocket = options.makeWebSocket;
+    }
+
+    this._requestTimeout = prefs.get("requestTimeout");
+
+    return Promise.resolve();
+  },
+
+  _reconnect: function () {
+    console.debug("reconnect()");
+    this._shutdownWS(false);
+    this._startBackoffTimer();
+  },
+
+  _shutdownWS: function(shouldCancelPending = true) {
+    console.debug("shutdownWS()");
+
+    if (this._currentState == STATE_READY) {
+      prefs.ignore("userAgentID", this);
+    }
+
+    this._currentState = STATE_SHUT_DOWN;
+    this._skipReconnect = false;
+
+    if (this._wsListener) {
+      this._wsListener._pushService = null;
+    }
+    try {
+        this._ws.close(0, null);
+    } catch (e) {}
+    this._ws = null;
+
+    this._lastPingTime = 0;
+
+    if (this._pingTimer) {
+      this._pingTimer.cancel();
+    }
+
+    if (shouldCancelPending) {
+      this._cancelPendingRequests();
+    }
+
+    if (this._notifyRequestQueue) {
+      this._notifyRequestQueue();
+      this._notifyRequestQueue = null;
+    }
+  },
+
+  uninit: function() {
+    // All pending requests (ideally none) are dropped at this point. We
+    // shouldn't have any applications performing registration/unregistration
+    // or receiving notifications.
+    this._shutdownWS();
+
+    if (this._backoffTimer) {
+      this._backoffTimer.cancel();
+    }
+    if (this._requestTimeoutTimer) {
+      this._requestTimeoutTimer.cancel();
+    }
+
+    this._mainPushService = null;
+
+    this._dataEnabled = false;
+  },
+
+  /**
+   * How retries work: If the WS is closed due to a socket error,
+   * _startBackoffTimer() is called. The retry timer is started and when
+   * it times out, beginWSSetup() is called again.
+   *
+   * If we are in the middle of a timeout (i.e. waiting), but
+   * a register/unregister is called, we don't want to wait around anymore.
+   * _sendRequest will automatically call beginWSSetup(), which will cancel the
+   * timer. In addition since the state will have changed, even if a pending
+   * timer event comes in (because the timer fired the event before it was
+   * cancelled), so the connection won't be reset.
+   */
+  _startBackoffTimer() {
+    console.debug("startBackoffTimer()");
+
+    // Calculate new timeout, but cap it to pingInterval.
+    let retryTimeout = prefs.get("retryBaseInterval") *
+                       Math.pow(2, this._retryFailCount);
+    retryTimeout = Math.min(retryTimeout, prefs.get("pingInterval"));
+
+    this._retryFailCount++;
+
+    console.debug("startBackoffTimer: Retry in", retryTimeout,
+      "Try number", this._retryFailCount);
+
+    if (!this._backoffTimer) {
+      this._backoffTimer = Cc["@mozilla.org/timer;1"]
+                               .createInstance(Ci.nsITimer);
+    }
+    this._backoffTimer.init(this, retryTimeout, Ci.nsITimer.TYPE_ONE_SHOT);
+  },
+
+  /** Indicates whether we're waiting for pongs or requests. */
+  _hasPendingRequests() {
+    return this._lastPingTime > 0 || this._pendingRequests.size > 0;
+  },
+
+  /**
+   * Starts the request timeout timer unless we're already waiting for a pong
+   * or register request.
+   */
+  _startRequestTimeoutTimer() {
+    if (this._hasPendingRequests()) {
+      return;
+    }
+    if (!this._requestTimeoutTimer) {
+      this._requestTimeoutTimer = Cc["@mozilla.org/timer;1"]
+                                    .createInstance(Ci.nsITimer);
+    }
+    this._requestTimeoutTimer.init(this,
+                                   this._requestTimeout,
+                                   Ci.nsITimer.TYPE_REPEATING_SLACK);
+  },
+
+  /** Starts or resets the ping timer. */
+  _startPingTimer() {
+    if (!this._pingTimer) {
+      this._pingTimer = Cc["@mozilla.org/timer;1"]
+                          .createInstance(Ci.nsITimer);
+    }
+    this._pingTimer.init(this, prefs.get("pingInterval"),
+                         Ci.nsITimer.TYPE_ONE_SHOT);
+  },
+
+  _makeWebSocket: function(uri) {
+    if (!prefs.get("connection.enabled")) {
+      console.warn("makeWebSocket: connection.enabled is not set to true.",
+        "Aborting.");
+      return null;
+    }
+    if (Services.io.offline) {
+      console.warn("makeWebSocket: Network is offline.");
+      return null;
+    }
+    let contractId = uri.scheme == "ws" ?
+                     "@mozilla.org/network/protocol;1?name=ws" :
+                     "@mozilla.org/network/protocol;1?name=wss";
+    let socket = Cc[contractId].createInstance(Ci.nsIWebSocketChannel);
+
+    socket.initLoadInfo(null, // aLoadingNode
+                        Services.scriptSecurityManager.getSystemPrincipal(),
+                        null, // aTriggeringPrincipal
+                        Ci.nsILoadInfo.SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,
+                        Ci.nsIContentPolicy.TYPE_WEBSOCKET);
+
+    return socket;
+  },
+
+  _beginWSSetup: function() {
+    console.debug("beginWSSetup()");
+    if (this._currentState != STATE_SHUT_DOWN) {
+      console.error("_beginWSSetup: Not in shutdown state! Current state",
+        this._currentState);
+      return;
+    }
+
+    // Stop any pending reconnects scheduled for the near future.
+    if (this._backoffTimer) {
+      this._backoffTimer.cancel();
+    }
+
+    let uri = this._serverURI;
+    if (!uri) {
+      return;
+    }
+    let socket = this._makeWebSocket(uri);
+    if (!socket) {
+      return;
+    }
+    this._ws = socket.QueryInterface(Ci.nsIWebSocketChannel);
+
+    console.debug("beginWSSetup: Connecting to", uri.spec);
+    this._wsListener = new PushWebSocketListener(this);
+    this._ws.protocol = "push-notification";
+
+    try {
+      // Grab a wakelock before we open the socket to ensure we don't go to
+      // sleep before connection the is opened.
+      this._ws.asyncOpen(uri, uri.spec, 0, this._wsListener, null);
+      this._currentState = STATE_WAITING_FOR_WS_START;
+    } catch(e) {
+      console.error("beginWSSetup: Error opening websocket.",
+        "asyncOpen failed", e);
+      this._reconnect();
+    }
+  },
+
+  connect: function(records) {
+    console.debug("connect()");
+    // Check to see if we need to do anything.
+    if (records.length > 0) {
+      this._beginWSSetup();
+    }
+  },
+
+  isConnected: function() {
+    return !!this._ws;
+  },
+
+  /**
+   * Protocol handler invoked by server message.
+   */
+  _handleHelloReply: function(reply) {
+    console.debug("handleHelloReply()");
+    if (this._currentState != STATE_WAITING_FOR_HELLO) {
+      console.error("handleHelloReply: Unexpected state", this._currentState,
+        "(expected STATE_WAITING_FOR_HELLO)");
+      this._shutdownWS();
+      return;
+    }
+
+    if (typeof reply.uaid !== "string") {
+      console.error("handleHelloReply: Received invalid UAID", reply.uaid);
+      this._shutdownWS();
+      return;
+    }
+
+    if (reply.uaid === "") {
+      console.error("handleHelloReply: Received empty UAID");
+      this._shutdownWS();
+      return;
+    }
+
+    // To avoid sticking extra large values sent by an evil server into prefs.
+    if (reply.uaid.length > 128) {
+      console.error("handleHelloReply: UAID received from server was too long",
+        reply.uaid);
+      this._shutdownWS();
+      return;
+    }
+
+    let sendRequests = () => {
+      if (this._notifyRequestQueue) {
+        this._notifyRequestQueue();
+        this._notifyRequestQueue = null;
+      }
+      this._sendPendingRequests();
+    };
+
+    function finishHandshake() {
+      this._UAID = reply.uaid;
+      this._currentState = STATE_READY;
+      prefs.observe("userAgentID", this);
+
+      this._dataEnabled = !!reply.use_webpush;
+      if (this._dataEnabled) {
+        this._mainPushService.getAllUnexpired().then(records =>
+          Promise.all(records.map(record =>
+            this._mainPushService.ensureCrypto(record).catch(error => {
+              console.error("finishHandshake: Error updating record",
+                record.keyID, error);
+            })
+          ))
+        ).then(sendRequests);
+      } else {
+        sendRequests();
+      }
+    }
+
+    // By this point we've got a UAID from the server that we are ready to
+    // accept.
+    //
+    // We unconditionally drop all existing registrations and notify service
+    // workers if we receive a new UAID. This ensures we expunge all stale
+    // registrations if the `userAgentID` pref is reset.
+    if (this._UAID != reply.uaid) {
+      console.debug("handleHelloReply: Received new UAID");
+
+      this._mainPushService.dropUnexpiredRegistrations()
+          .then(finishHandshake.bind(this));
+
+      return;
+    }
+
+    // otherwise we are good to go
+    finishHandshake.bind(this)();
+  },
+
+  /**
+   * Protocol handler invoked by server message.
+   */
+  _handleRegisterReply: function(reply) {
+    console.debug("handleRegisterReply()");
+
+    let tmp = this._takeRequestForReply(reply);
+    if (!tmp) {
+      return;
+    }
+
+    if (reply.status == 200) {
+      try {
+        Services.io.newURI(reply.pushEndpoint, null, null);
+      }
+      catch (e) {
+        tmp.reject(new Error("Invalid push endpoint: " + reply.pushEndpoint));
+        return;
+      }
+
+      let record = new PushRecordWebSocket({
+        channelID: reply.channelID,
+        pushEndpoint: reply.pushEndpoint,
+        scope: tmp.record.scope,
+        originAttributes: tmp.record.originAttributes,
+        version: null,
+        systemRecord: tmp.record.systemRecord,
+        appServerKey: tmp.record.appServerKey,
+        ctime: Date.now(),
+      });
+      Services.telemetry.getHistogramById("PUSH_API_SUBSCRIBE_WS_TIME").add(Date.now() - tmp.ctime);
+      tmp.resolve(record);
+    } else {
+      console.error("handleRegisterReply: Unexpected server response", reply);
+      tmp.reject(new Error("Wrong status code for register reply: " +
+        reply.status));
+    }
+  },
+
+  _handleUnregisterReply(reply) {
+    console.debug("handleUnregisterReply()");
+
+    let request = this._takeRequestForReply(reply);
+    if (!request) {
+      return;
+    }
+
+    let success = reply.status === 200;
+    request.resolve(success);
+  },
+
+  _handleDataUpdate: function(update) {
+    let promise;
+    if (typeof update.channelID != "string") {
+      console.warn("handleDataUpdate: Discarding update without channel ID",
+        update);
+      return;
+    }
+    function updateRecord(record) {
+      // Ignore messages that we've already processed. This can happen if the
+      // connection drops between notifying the service worker and acking the
+      // the message. In that case, the server will re-send the message on
+      // reconnect.
+      if (record.hasRecentMessageID(update.version)) {
+        console.warn("handleDataUpdate: Ignoring duplicate message",
+          update.version);
+        return null;
+      }
+      record.noteRecentMessageID(update.version);
+      return record;
+    }
+    if (typeof update.data != "string") {
+      promise = this._mainPushService.receivedPushMessage(
+        update.channelID,
+        update.version,
+        null,
+        null,
+        updateRecord
+      );
+    } else {
+      let message = ChromeUtils.base64URLDecode(update.data, {
+        // The Push server may append padding.
+        padding: "ignore",
+      });
+      promise = this._mainPushService.receivedPushMessage(
+        update.channelID,
+        update.version,
+        update.headers,
+        message,
+        updateRecord
+      );
+    }
+    promise.then(status => {
+      this._sendAck(update.channelID, update.version, status);
+    }, err => {
+      console.error("handleDataUpdate: Error delivering message", update, err);
+      this._sendAck(update.channelID, update.version,
+        Ci.nsIPushErrorReporter.ACK_DECRYPTION_ERROR);
+    }).catch(err => {
+      console.error("handleDataUpdate: Error acknowledging message", update,
+        err);
+    });
+  },
+
+  /**
+   * Protocol handler invoked by server message.
+   */
+  _handleNotificationReply: function(reply) {
+    console.debug("handleNotificationReply()");
+    if (this._dataEnabled) {
+      this._handleDataUpdate(reply);
+      return;
+    }
+
+    if (typeof reply.updates !== 'object') {
+      console.warn("handleNotificationReply: Missing updates", reply.updates);
+      return;
+    }
+
+    console.debug("handleNotificationReply: Got updates", reply.updates);
+    for (let i = 0; i < reply.updates.length; i++) {
+      let update = reply.updates[i];
+      console.debug("handleNotificationReply: Handling update", update);
+      if (typeof update.channelID !== "string") {
+        console.debug("handleNotificationReply: Invalid update at index",
+          i, update);
+        continue;
+      }
+
+      if (update.version === undefined) {
+        console.debug("handleNotificationReply: Missing version", update);
+        continue;
+      }
+
+      let version = update.version;
+
+      if (typeof version === "string") {
+        version = parseInt(version, 10);
+      }
+
+      if (typeof version === "number" && version >= 0) {
+        // FIXME(nsm): this relies on app update notification being infallible!
+        // eventually fix this
+        this._receivedUpdate(update.channelID, version);
+      }
+    }
+  },
+
+  reportDeliveryError(messageID, reason) {
+    console.debug("reportDeliveryError()");
+    let code = kDELIVERY_REASON_TO_CODE[reason];
+    if (!code) {
+      throw new Error('Invalid delivery error reason');
+    }
+    let data = {messageType: 'nack',
+                version: messageID,
+                code: code};
+    this._queueRequest(data);
+  },
+
+  _sendAck(channelID, version, status) {
+    console.debug("sendAck()");
+    let code = kACK_STATUS_TO_CODE[status];
+    if (!code) {
+      throw new Error('Invalid ack status');
+    }
+    let data = {messageType: 'ack',
+                updates: [{channelID: channelID,
+                           version: version,
+                           code: code}]};
+    this._queueRequest(data);
+  },
+
+  _generateID: function() {
+    let uuidGenerator = Cc["@mozilla.org/uuid-generator;1"]
+                          .getService(Ci.nsIUUIDGenerator);
+    // generateUUID() gives a UUID surrounded by {...}, slice them off.
+    return uuidGenerator.generateUUID().toString().slice(1, -1);
+  },
+
+  register(record) {
+    console.debug("register() ", record);
+
+    let data = {channelID: this._generateID(),
+                messageType: "register"};
+
+    if (record.appServerKey) {
+      data.key = ChromeUtils.base64URLEncode(record.appServerKey, {
+        // The Push server requires padding.
+        pad: true,
+      });
+    }
+
+    return this._sendRequestForReply(record, data).then(record => {
+      if (!this._dataEnabled) {
+        return record;
+      }
+      return PushCrypto.generateKeys()
+        .then(([publicKey, privateKey]) => {
+          record.p256dhPublicKey = publicKey;
+          record.p256dhPrivateKey = privateKey;
+          record.authenticationSecret = PushCrypto.generateAuthenticationSecret();
+          return record;
+        });
+    });
+  },
+
+  unregister(record, reason) {
+    console.debug("unregister() ", record, reason);
+
+    return Promise.resolve().then(_ => {
+      let code = kUNREGISTER_REASON_TO_CODE[reason];
+      if (!code) {
+        throw new Error('Invalid unregister reason');
+      }
+      let data = {channelID: record.channelID,
+                  messageType: "unregister",
+                  code: code};
+
+      return this._sendRequestForReply(record, data);
+    });
+  },
+
+  _queueStart: Promise.resolve(),
+  _notifyRequestQueue: null,
+  _queue: null,
+  _enqueue: function(op) {
+    console.debug("enqueue()");
+    if (!this._queue) {
+      this._queue = this._queueStart;
+    }
+    this._queue = this._queue
+                    .then(op)
+                    .catch(_ => {});
+  },
+
+  /** Sends a request to the server. */
+  _send(data) {
+    if (this._currentState != STATE_READY) {
+      console.warn("send: Unexpected state; ignoring message",
+        this._currentState);
+      return;
+    }
+    if (!this._requestHasReply(data)) {
+      this._wsSendMessage(data);
+      return;
+    }
+    // If we're expecting a reply, check that we haven't cancelled the request.
+    let key = this._makePendingRequestKey(data);
+    if (!this._pendingRequests.has(key)) {
+      console.log("send: Request cancelled; ignoring message", key);
+      return;
+    }
+    this._wsSendMessage(data);
+  },
+
+  /** Indicates whether a request has a corresponding reply from the server. */
+  _requestHasReply(data) {
+    return data.messageType == "register" || data.messageType == "unregister";
+  },
+
+  /**
+   * Sends all pending requests that expect replies. Called after the connection
+   * is established and the handshake is complete.
+   */
+  _sendPendingRequests() {
+    this._enqueue(_ => {
+      for (let request of this._pendingRequests.values()) {
+        this._send(request.data);
+      }
+    });
+  },
+
+  /** Queues an outgoing request, establishing a connection if necessary. */
+  _queueRequest(data) {
+    console.debug("queueRequest()", data);
+
+    if (this._currentState == STATE_READY) {
+      // If we're ready, no need to queue; just send the request.
+      this._send(data);
+      return;
+    }
+
+    // Otherwise, we're still setting up. If we don't have a request queue,
+    // make one now.
+    if (!this._notifyRequestQueue) {
+      let promise = new Promise((resolve, reject) => {
+        this._notifyRequestQueue = resolve;
+      });
+      this._enqueue(_ => promise);
+    }
+
+    let isRequest = this._requestHasReply(data);
+    if (!isRequest) {
+      // Don't queue requests, since they're stored in `_pendingRequests`, and
+      // `_sendPendingRequests` will send them after reconnecting. Without this
+      // check, we'd send requests twice.
+      this._enqueue(_ => this._send(data));
+    }
+
+    if (!this._ws) {
+      // This will end up calling notifyRequestQueue().
+      this._beginWSSetup();
+      // If beginWSSetup does not succeed to make ws, notifyRequestQueue will
+      // not be call.
+      if (!this._ws && this._notifyRequestQueue) {
+        this._notifyRequestQueue();
+        this._notifyRequestQueue = null;
+      }
+    }
+  },
+
+  _receivedUpdate: function(aChannelID, aLatestVersion) {
+    console.debug("receivedUpdate: Updating", aChannelID, "->", aLatestVersion);
+
+    this._mainPushService.receivedPushMessage(aChannelID, "", null, null, record => {
+      if (record.version === null ||
+          record.version < aLatestVersion) {
+        console.debug("receivedUpdate: Version changed for", aChannelID,
+          aLatestVersion);
+        record.version = aLatestVersion;
+        return record;
+      }
+      console.debug("receivedUpdate: No significant version change for",
+        aChannelID, aLatestVersion);
+      return null;
+    }).then(status => {
+      this._sendAck(aChannelID, aLatestVersion, status);
+    }).catch(err => {
+      console.error("receivedUpdate: Error acknowledging message", aChannelID,
+        aLatestVersion, err);
+    });
+  },
+
+  // begin Push protocol handshake
+  _wsOnStart: function(context) {
+    console.debug("wsOnStart()");
+
+    if (this._currentState != STATE_WAITING_FOR_WS_START) {
+      console.error("wsOnStart: NOT in STATE_WAITING_FOR_WS_START. Current",
+        "state", this._currentState, "Skipping");
+      return;
+    }
+
+    let data = {
+      messageType: "hello",
+      use_webpush: true,
+    };
+
+    if (this._UAID) {
+      data.uaid = this._UAID;
+    }
+
+    this._wsSendMessage(data);
+    this._currentState = STATE_WAITING_FOR_HELLO;
+  },
+
+  /**
+   * This statusCode is not the websocket protocol status code, but the TCP
+   * connection close status code.
+   *
+   * If we do not explicitly call ws.close() then statusCode is always
+   * NS_BASE_STREAM_CLOSED, even on a successful close.
+   */
+  _wsOnStop: function(context, statusCode) {
+    console.debug("wsOnStop()");
+
+    if (statusCode != Cr.NS_OK && !this._skipReconnect) {
+      console.debug("wsOnStop: Reconnecting after socket error", statusCode);
+      this._reconnect();
+      return;
+    }
+
+    this._shutdownWS();
+  },
+
+  _wsOnMessageAvailable: function(context, message) {
+    console.debug("wsOnMessageAvailable()", message);
+
+    // Clearing the last ping time indicates we're no longer waiting for a pong.
+    this._lastPingTime = 0;
+
+    let reply;
+    try {
+      reply = JSON.parse(message);
+    } catch(e) {
+      console.warn("wsOnMessageAvailable: Invalid JSON", message, e);
+      return;
+    }
+
+    // If we receive a message, we know the connection succeeded. Reset the
+    // connection attempt and ping interval counters.
+    this._retryFailCount = 0;
+
+    let doNotHandle = false;
+    if ((message === '{}') ||
+        (reply.messageType === undefined) ||
+        (reply.messageType === "ping") ||
+        (typeof reply.messageType != "string")) {
+      console.debug("wsOnMessageAvailable: Pong received");
+      doNotHandle = true;
+    }
+
+    // Reset the ping timer.  Note: This path is executed at every step of the
+    // handshake, so this timer does not need to be set explicitly at startup.
+    this._startPingTimer();
+
+    // If it is a ping, do not handle the message.
+    if (doNotHandle) {
+      return;
+    }
+
+    // A whitelist of protocol handlers. Add to these if new messages are added
+    // in the protocol.
+    let handlers = ["Hello", "Register", "Unregister", "Notification"];
+
+    // Build up the handler name to call from messageType.
+    // e.g. messageType == "register" -> _handleRegisterReply.
+    let handlerName = reply.messageType[0].toUpperCase() +
+                      reply.messageType.slice(1).toLowerCase();
+
+    if (handlers.indexOf(handlerName) == -1) {
+      console.warn("wsOnMessageAvailable: No whitelisted handler", handlerName,
+        "for message", reply.messageType);
+      return;
+    }
+
+    let handler = "_handle" + handlerName + "Reply";
+
+    if (typeof this[handler] !== "function") {
+      console.warn("wsOnMessageAvailable: Handler", handler,
+        "whitelisted but not implemented");
+      return;
+    }
+
+    this[handler](reply);
+  },
+
+  /**
+   * The websocket should never be closed. Since we don't call ws.close(),
+   * _wsOnStop() receives error code NS_BASE_STREAM_CLOSED (see comment in that
+   * function), which calls reconnect and re-establishes the WebSocket
+   * connection.
+   *
+   * If the server requested that we back off, we won't reconnect until the
+   * next network state change event, or until we need to send a new register
+   * request.
+   */
+  _wsOnServerClose: function(context, aStatusCode, aReason) {
+    console.debug("wsOnServerClose()", aStatusCode, aReason);
+
+    if (aStatusCode == kBACKOFF_WS_STATUS_CODE) {
+      console.debug("wsOnServerClose: Skipping automatic reconnect");
+      this._skipReconnect = true;
+    }
+  },
+
+  /**
+   * Rejects all pending register requests with errors.
+   */
+  _cancelPendingRequests() {
+    for (let request of this._pendingRequests.values()) {
+      request.reject(new Error("Request aborted"));
+    }
+    this._pendingRequests.clear();
+  },
+
+  /** Creates a case-insensitive map key for a request that expects a reply. */
+  _makePendingRequestKey(data) {
+    return (data.messageType + "|" + data.channelID).toLowerCase();
+  },
+
+  /** Sends a request and waits for a reply from the server. */
+  _sendRequestForReply(record, data) {
+    return Promise.resolve().then(_ => {
+      // start the timer since we now have at least one request
+      this._startRequestTimeoutTimer();
+
+      let key = this._makePendingRequestKey(data);
+      if (!this._pendingRequests.has(key)) {
+        let request = {
+          data: data,
+          record: record,
+          ctime: Date.now(),
+        };
+        request.promise = new Promise((resolve, reject) => {
+          request.resolve = resolve;
+          request.reject = reject;
+        });
+        this._pendingRequests.set(key, request);
+        this._queueRequest(data);
+      }
+
+      return this._pendingRequests.get(key).promise;
+    });
+  },
+
+  /** Removes and returns a pending request for a server reply. */
+  _takeRequestForReply(reply) {
+    if (typeof reply.channelID !== "string") {
+      return null;
+    }
+    let key = this._makePendingRequestKey(reply);
+    let request = this._pendingRequests.get(key);
+    if (!request) {
+      return null;
+    }
+    this._pendingRequests.delete(key);
+    if (!this._hasPendingRequests()) {
+      this._requestTimeoutTimer.cancel();
+    }
+    return request;
+  },
+};
+
+function PushRecordWebSocket(record) {
+  PushRecord.call(this, record);
+  this.channelID = record.channelID;
+  this.version = record.version;
+}
+
+PushRecordWebSocket.prototype = Object.create(PushRecord.prototype, {
+  keyID: {
+    get() {
+      return this.channelID;
+    },
+  },
+});
+
+PushRecordWebSocket.prototype.toSubscription = function() {
+  let subscription = PushRecord.prototype.toSubscription.call(this);
+  subscription.version = this.version;
+  return subscription;
+};