1 files changed, 393 insertions, 0 deletions
diff --git a/modules/ContentWebRTC.jsm b/modules/ContentWebRTC.jsm
new file mode 100644
index 0000000..fd50176
--- /dev/null
+++ b/modules/ContentWebRTC.jsm
@@ -0,0 +1,393 @@
+/* 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 {classes: Cc, interfaces: Ci, results: Cr, utils: Cu} = Components;
+
+this.EXPORTED_SYMBOLS = [ "ContentWebRTC" ];
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+XPCOMUtils.defineLazyServiceGetter(this, "MediaManagerService",
+                                   "@mozilla.org/mediaManagerService;1",
+                                   "nsIMediaManagerService");
+
+const kBrowserURL = "chrome://browser/content/browser.xul";
+
+this.ContentWebRTC = {
+  _initialized: false,
+
+  init: function() {
+    if (this._initialized)
+      return;
+
+    this._initialized = true;
+    Services.obs.addObserver(handleGUMRequest, "getUserMedia:request", false);
+    Services.obs.addObserver(handlePCRequest, "PeerConnection:request", false);
+    Services.obs.addObserver(updateIndicators, "recording-device-events", false);
+    Services.obs.addObserver(removeBrowserSpecificIndicator, "recording-window-ended", false);
+
+    if (Services.appinfo.processType == Services.appinfo.PROCESS_TYPE_CONTENT)
+      Services.obs.addObserver(processShutdown, "content-child-shutdown", false);
+  },
+
+  uninit: function() {
+    Services.obs.removeObserver(handleGUMRequest, "getUserMedia:request");
+    Services.obs.removeObserver(handlePCRequest, "PeerConnection:request");
+    Services.obs.removeObserver(updateIndicators, "recording-device-events");
+    Services.obs.removeObserver(removeBrowserSpecificIndicator, "recording-window-ended");
+
+    if (Services.appinfo.processType == Services.appinfo.PROCESS_TYPE_CONTENT)
+      Services.obs.removeObserver(processShutdown, "content-child-shutdown");
+
+    this._initialized = false;
+  },
+
+  // Called only for 'unload' to remove pending gUM prompts in reloaded frames.
+  handleEvent: function(aEvent) {
+    let contentWindow = aEvent.target.defaultView;
+    let mm = getMessageManagerForWindow(contentWindow);
+    for (let key of contentWindow.pendingGetUserMediaRequests.keys()) {
+      mm.sendAsyncMessage("webrtc:CancelRequest", key);
+    }
+    for (let key of contentWindow.pendingPeerConnectionRequests.keys()) {
+      mm.sendAsyncMessage("rtcpeer:CancelRequest", key);
+    }
+  },
+
+  receiveMessage: function(aMessage) {
+    switch (aMessage.name) {
+      case "rtcpeer:Allow":
+      case "rtcpeer:Deny": {
+        let callID = aMessage.data.callID;
+        let contentWindow = Services.wm.getOuterWindowWithId(aMessage.data.windowID);
+        forgetPCRequest(contentWindow, callID);
+        let topic = (aMessage.name == "rtcpeer:Allow") ? "PeerConnection:response:allow" :
+                                                         "PeerConnection:response:deny";
+        Services.obs.notifyObservers(null, topic, callID);
+        break;
+      }
+      case "webrtc:Allow": {
+        let callID = aMessage.data.callID;
+        let contentWindow = Services.wm.getOuterWindowWithId(aMessage.data.windowID);
+        let devices = contentWindow.pendingGetUserMediaRequests.get(callID);
+        forgetGUMRequest(contentWindow, callID);
+
+        let allowedDevices = Cc["@mozilla.org/array;1"]
+                               .createInstance(Ci.nsIMutableArray);
+        for (let deviceIndex of aMessage.data.devices)
+           allowedDevices.appendElement(devices[deviceIndex], /* weak =*/ false);
+
+        Services.obs.notifyObservers(allowedDevices, "getUserMedia:response:allow", callID);
+        break;
+      }
+      case "webrtc:Deny":
+        denyGUMRequest(aMessage.data);
+        break;
+      case "webrtc:StopSharing":
+        Services.obs.notifyObservers(null, "getUserMedia:revoke", aMessage.data);
+        break;
+    }
+  }
+};
+
+function handlePCRequest(aSubject, aTopic, aData) {
+  let { windowID, innerWindowID, callID, isSecure } = aSubject;
+  let contentWindow = Services.wm.getOuterWindowWithId(windowID);
+
+  let mm = getMessageManagerForWindow(contentWindow);
+  if (!mm) {
+    // Workaround for Bug 1207784. To use WebRTC, add-ons right now use
+    // hiddenWindow.mozRTCPeerConnection which is only privileged on OSX. Other
+    // platforms end up here without a message manager.
+    // TODO: Remove once there's a better way (1215591).
+
+    // Skip permission check in the absence of a message manager.
+    Services.obs.notifyObservers(null, "PeerConnection:response:allow", callID);
+    return;
+  }
+
+  if (!contentWindow.pendingPeerConnectionRequests) {
+    setupPendingListsInitially(contentWindow);
+  }
+  contentWindow.pendingPeerConnectionRequests.add(callID);
+
+  let request = {
+    windowID: windowID,
+    innerWindowID: innerWindowID,
+    callID: callID,
+    documentURI: contentWindow.document.documentURI,
+    secure: isSecure,
+  };
+  mm.sendAsyncMessage("rtcpeer:Request", request);
+}
+
+function handleGUMRequest(aSubject, aTopic, aData) {
+  let constraints = aSubject.getConstraints();
+  let secure = aSubject.isSecure;
+  let contentWindow = Services.wm.getOuterWindowWithId(aSubject.windowID);
+
+  contentWindow.navigator.mozGetUserMediaDevices(
+    constraints,
+    function (devices) {
+      // If the window has been closed while we were waiting for the list of
+      // devices, there's nothing to do in the callback anymore.
+      if (contentWindow.closed)
+        return;
+
+      prompt(contentWindow, aSubject.windowID, aSubject.callID,
+             constraints, devices, secure);
+    },
+    function (error) {
+      // bug 827146 -- In the future, the UI should catch NotFoundError
+      // and allow the user to plug in a device, instead of immediately failing.
+      denyGUMRequest({callID: aSubject.callID}, error);
+    },
+    aSubject.innerWindowID,
+    aSubject.callID);
+}
+
+function prompt(aContentWindow, aWindowID, aCallID, aConstraints, aDevices, aSecure) {
+  let audioDevices = [];
+  let videoDevices = [];
+  let devices = [];
+
+  // MediaStreamConstraints defines video as 'boolean or MediaTrackConstraints'.
+  let video = aConstraints.video || aConstraints.picture;
+  let audio = aConstraints.audio;
+  let sharingScreen = video && typeof(video) != "boolean" &&
+                      video.mediaSource != "camera";
+  let sharingAudio = audio && typeof(audio) != "boolean" &&
+                     audio.mediaSource != "microphone";
+  for (let device of aDevices) {
+    device = device.QueryInterface(Ci.nsIMediaDevice);
+    switch (device.type) {
+      case "audio":
+        // Check that if we got a microphone, we have not requested an audio
+        // capture, and if we have requested an audio capture, we are not
+        // getting a microphone instead.
+        if (audio && (device.mediaSource == "microphone") != sharingAudio) {
+          audioDevices.push({name: device.name, deviceIndex: devices.length,
+                             id: device.rawId, mediaSource: device.mediaSource});
+          devices.push(device);
+        }
+        break;
+      case "video":
+        // Verify that if we got a camera, we haven't requested a screen share,
+        // or that if we requested a screen share we aren't getting a camera.
+        if (video && (device.mediaSource == "camera") != sharingScreen) {
+          let deviceObject = {name: device.name, deviceIndex: devices.length,
+                              id: device.rawId, mediaSource: device.mediaSource};
+          if (device.scary)
+            deviceObject.scary = true;
+          videoDevices.push(deviceObject);
+          devices.push(device);
+        }
+        break;
+    }
+  }
+
+  let requestTypes = [];
+  if (videoDevices.length)
+    requestTypes.push(sharingScreen ? "Screen" : "Camera");
+  if (audioDevices.length)
+    requestTypes.push(sharingAudio ? "AudioCapture" : "Microphone");
+
+  if (!requestTypes.length) {
+    denyGUMRequest({callID: aCallID}, "NotFoundError");
+    return;
+  }
+
+  if (!aContentWindow.pendingGetUserMediaRequests) {
+    setupPendingListsInitially(aContentWindow);
+  }
+  aContentWindow.pendingGetUserMediaRequests.set(aCallID, devices);
+
+  let request = {
+    callID: aCallID,
+    windowID: aWindowID,
+    origin: aContentWindow.origin,
+    documentURI: aContentWindow.document.documentURI,
+    secure: aSecure,
+    requestTypes: requestTypes,
+    sharingScreen: sharingScreen,
+    sharingAudio: sharingAudio,
+    audioDevices: audioDevices,
+    videoDevices: videoDevices
+  };
+
+  let mm = getMessageManagerForWindow(aContentWindow);
+  mm.sendAsyncMessage("webrtc:Request", request);
+}
+
+function denyGUMRequest(aData, aError) {
+  let msg = null;
+  if (aError) {
+    msg = Cc["@mozilla.org/supports-string;1"].createInstance(Ci.nsISupportsString);
+    msg.data = aError;
+  }
+  Services.obs.notifyObservers(msg, "getUserMedia:response:deny", aData.callID);
+
+  if (!aData.windowID)
+    return;
+  let contentWindow = Services.wm.getOuterWindowWithId(aData.windowID);
+  if (contentWindow.pendingGetUserMediaRequests)
+    forgetGUMRequest(contentWindow, aData.callID);
+}
+
+function forgetGUMRequest(aContentWindow, aCallID) {
+  aContentWindow.pendingGetUserMediaRequests.delete(aCallID);
+  forgetPendingListsEventually(aContentWindow);
+}
+
+function forgetPCRequest(aContentWindow, aCallID) {
+  aContentWindow.pendingPeerConnectionRequests.delete(aCallID);
+  forgetPendingListsEventually(aContentWindow);
+}
+
+function setupPendingListsInitially(aContentWindow) {
+  if (aContentWindow.pendingGetUserMediaRequests) {
+    return;
+  }
+  aContentWindow.pendingGetUserMediaRequests = new Map();
+  aContentWindow.pendingPeerConnectionRequests = new Set();
+  aContentWindow.addEventListener("unload", ContentWebRTC);
+}
+
+function forgetPendingListsEventually(aContentWindow) {
+  if (aContentWindow.pendingGetUserMediaRequests.size ||
+      aContentWindow.pendingPeerConnectionRequests.size) {
+    return;
+  }
+  aContentWindow.pendingGetUserMediaRequests = null;
+  aContentWindow.pendingPeerConnectionRequests = null;
+  aContentWindow.removeEventListener("unload", ContentWebRTC);
+}
+
+function updateIndicators(aSubject, aTopic, aData) {
+  if (aSubject instanceof Ci.nsIPropertyBag &&
+      aSubject.getProperty("requestURL") == kBrowserURL) {
+    // Ignore notifications caused by the browser UI showing previews.
+    return;
+  }
+
+  let contentWindowArray = MediaManagerService.activeMediaCaptureWindows;
+  let count = contentWindowArray.length;
+
+  let state = {
+    showGlobalIndicator: count > 0,
+    showCameraIndicator: false,
+    showMicrophoneIndicator: false,
+    showScreenSharingIndicator: ""
+  };
+
+  let cpmm = Cc["@mozilla.org/childprocessmessagemanager;1"]
+               .getService(Ci.nsIMessageSender);
+  cpmm.sendAsyncMessage("webrtc:UpdatingIndicators");
+
+  // If several iframes in the same page use media streams, it's possible to
+  // have the same top level window several times. We use a Set to avoid
+  // sending duplicate notifications.
+  let contentWindows = new Set();
+  for (let i = 0; i < count; ++i) {
+    contentWindows.add(contentWindowArray.queryElementAt(i, Ci.nsISupports).top);
+  }
+
+  for (let contentWindow of contentWindows) {
+    if (contentWindow.document.documentURI == kBrowserURL) {
+      // There may be a preview shown at the same time as other streams.
+      continue;
+    }
+
+    let tabState = getTabStateForContentWindow(contentWindow);
+    if (tabState.camera)
+      state.showCameraIndicator = true;
+    if (tabState.microphone)
+      state.showMicrophoneIndicator = true;
+    if (tabState.screen) {
+      if (tabState.screen == "Screen") {
+        state.showScreenSharingIndicator = "Screen";
+      }
+      else if (tabState.screen == "Window") {
+        if (state.showScreenSharingIndicator != "Screen")
+          state.showScreenSharingIndicator = "Window";
+      }
+      else if (tabState.screen == "Application") {
+        if (!state.showScreenSharingIndicator)
+          state.showScreenSharingIndicator = "Application";
+      }
+      else if (tabState.screen == "Browser") {
+        if (!state.showScreenSharingIndicator)
+          state.showScreenSharingIndicator = "Browser";
+      }
+    }
+    let mm = getMessageManagerForWindow(contentWindow);
+    mm.sendAsyncMessage("webrtc:UpdateBrowserIndicators", tabState);
+  }
+
+  cpmm.sendAsyncMessage("webrtc:UpdateGlobalIndicators", state);
+}
+
+function removeBrowserSpecificIndicator(aSubject, aTopic, aData) {
+  let contentWindow = Services.wm.getOuterWindowWithId(aData).top;
+  if (contentWindow.document.documentURI == kBrowserURL) {
+    // Ignore notifications caused by the browser UI showing previews.
+    return;
+  }
+
+  let tabState = getTabStateForContentWindow(contentWindow);
+  if (!tabState.camera && !tabState.microphone && !tabState.screen)
+    tabState = {windowId: tabState.windowId};
+
+  let mm = getMessageManagerForWindow(contentWindow);
+  if (mm)
+    mm.sendAsyncMessage("webrtc:UpdateBrowserIndicators", tabState);
+}
+
+function getTabStateForContentWindow(aContentWindow) {
+  let camera = {}, microphone = {}, screen = {}, window = {}, app = {}, browser = {};
+  MediaManagerService.mediaCaptureWindowState(aContentWindow, camera, microphone,
+                                              screen, window, app, browser);
+  let tabState = {camera: camera.value, microphone: microphone.value};
+  if (screen.value)
+    tabState.screen = "Screen";
+  else if (window.value)
+    tabState.screen = "Window";
+  else if (app.value)
+    tabState.screen = "Application";
+  else if (browser.value)
+    tabState.screen = "Browser";
+
+  tabState.windowId = getInnerWindowIDForWindow(aContentWindow);
+  tabState.documentURI = aContentWindow.document.documentURI;
+
+  return tabState;
+}
+
+function getInnerWindowIDForWindow(aContentWindow) {
+  return aContentWindow.QueryInterface(Ci.nsIInterfaceRequestor)
+                       .getInterface(Ci.nsIDOMWindowUtils)
+                       .currentInnerWindowID;
+}
+
+function getMessageManagerForWindow(aContentWindow) {
+  let ir = aContentWindow.QueryInterface(Ci.nsIInterfaceRequestor)
+                         .getInterface(Ci.nsIDocShell)
+                         .sameTypeRootTreeItem
+                         .QueryInterface(Ci.nsIInterfaceRequestor);
+  try {
+    // If e10s is disabled, this throws NS_NOINTERFACE for closed tabs.
+    return ir.getInterface(Ci.nsIContentFrameMessageManager);
+  } catch (e) {
+    if (e.result == Cr.NS_NOINTERFACE) {
+      return null;
+    }
+    throw e;
+  }
+}
+
+function processShutdown() {
+  ContentWebRTC.uninit();
+}