1 files changed, 551 insertions, 0 deletions
diff --git a/toolkit/components/webextensions/ExtensionParent.jsm b/toolkit/components/webextensions/ExtensionParent.jsm
new file mode 100644
index 000000000..b88500d1e
--- /dev/null
+++ b/toolkit/components/webextensions/ExtensionParent.jsm
@@ -0,0 +1,551 @@
+/* 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";
+
+/**
+ * This module contains code for managing APIs that need to run in the
+ * parent process, and handles the parent side of operations that need
+ * to be proxied from ExtensionChild.jsm.
+ */
+
+const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
+
+/* exported ExtensionParent */
+
+this.EXPORTED_SYMBOLS = ["ExtensionParent"];
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "AddonManager",
+                                  "resource://gre/modules/AddonManager.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "AppConstants",
+                                  "resource://gre/modules/AppConstants.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "MessageChannel",
+                                  "resource://gre/modules/MessageChannel.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "NativeApp",
+                                  "resource://gre/modules/NativeMessaging.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
+                                  "resource://gre/modules/NetUtil.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Schemas",
+                                  "resource://gre/modules/Schemas.jsm");
+
+Cu.import("resource://gre/modules/ExtensionCommon.jsm");
+Cu.import("resource://gre/modules/ExtensionUtils.jsm");
+
+var {
+  BaseContext,
+  SchemaAPIManager,
+} = ExtensionCommon;
+
+var {
+  MessageManagerProxy,
+  SpreadArgs,
+  defineLazyGetter,
+  findPathInObject,
+} = ExtensionUtils;
+
+const BASE_SCHEMA = "chrome://extensions/content/schemas/manifest.json";
+const CATEGORY_EXTENSION_SCHEMAS = "webextension-schemas";
+const CATEGORY_EXTENSION_SCRIPTS = "webextension-scripts";
+
+let schemaURLs = new Set();
+
+if (!AppConstants.RELEASE_OR_BETA) {
+  schemaURLs.add("chrome://extensions/content/schemas/experiments.json");
+}
+
+let GlobalManager;
+let ParentAPIManager;
+let ProxyMessenger;
+
+// This object loads the ext-*.js scripts that define the extension API.
+let apiManager = new class extends SchemaAPIManager {
+  constructor() {
+    super("main");
+    this.initialized = null;
+  }
+
+  // Loads all the ext-*.js scripts currently registered.
+  lazyInit() {
+    if (this.initialized) {
+      return this.initialized;
+    }
+
+    // Load order matters here. The base manifest defines types which are
+    // extended by other schemas, so needs to be loaded first.
+    let promise = Schemas.load(BASE_SCHEMA).then(() => {
+      let promises = [];
+      for (let [/* name */, url] of XPCOMUtils.enumerateCategoryEntries(CATEGORY_EXTENSION_SCHEMAS)) {
+        promises.push(Schemas.load(url));
+      }
+      for (let url of schemaURLs) {
+        promises.push(Schemas.load(url));
+      }
+      return Promise.all(promises);
+    });
+
+    for (let [/* name */, value] of XPCOMUtils.enumerateCategoryEntries(CATEGORY_EXTENSION_SCRIPTS)) {
+      this.loadScript(value);
+    }
+
+    this.initialized = promise;
+    return this.initialized;
+  }
+
+  registerSchemaAPI(namespace, envType, getAPI) {
+    if (envType == "addon_parent" || envType == "content_parent") {
+      super.registerSchemaAPI(namespace, envType, getAPI);
+    }
+  }
+}();
+
+// Subscribes to messages related to the extension messaging API and forwards it
+// to the relevant message manager. The "sender" field for the `onMessage` and
+// `onConnect` events are updated if needed.
+ProxyMessenger = {
+  _initialized: false,
+  init() {
+    if (this._initialized) {
+      return;
+    }
+    this._initialized = true;
+
+    // TODO(robwu): When addons move to a separate process, we should use the
+    // parent process manager(s) of the addon process(es) instead of the
+    // in-process one.
+    let pipmm = Services.ppmm.getChildAt(0);
+    // Listen on the global frame message manager because content scripts send
+    // and receive extension messages via their frame.
+    // Listen on the parent process message manager because `runtime.connect`
+    // and `runtime.sendMessage` requests must be delivered to all frames in an
+    // addon process (by the API contract).
+    // And legacy addons are not associated with a frame, so that is another
+    // reason for having a parent process manager here.
+    let messageManagers = [Services.mm, pipmm];
+
+    MessageChannel.addListener(messageManagers, "Extension:Connect", this);
+    MessageChannel.addListener(messageManagers, "Extension:Message", this);
+    MessageChannel.addListener(messageManagers, "Extension:Port:Disconnect", this);
+    MessageChannel.addListener(messageManagers, "Extension:Port:PostMessage", this);
+  },
+
+  receiveMessage({target, messageName, channelId, sender, recipient, data, responseType}) {
+    if (recipient.toNativeApp) {
+      let {childId, toNativeApp} = recipient;
+      if (messageName == "Extension:Message") {
+        let context = ParentAPIManager.getContextById(childId);
+        return new NativeApp(context, toNativeApp).sendMessage(data);
+      }
+      if (messageName == "Extension:Connect") {
+        let context = ParentAPIManager.getContextById(childId);
+        NativeApp.onConnectNative(context, target.messageManager, data.portId, sender, toNativeApp);
+        return true;
+      }
+      // "Extension:Port:Disconnect" and "Extension:Port:PostMessage" for
+      // native messages are handled by NativeApp.
+      return;
+    }
+    let extension = GlobalManager.extensionMap.get(sender.extensionId);
+    let receiverMM = this._getMessageManagerForRecipient(recipient);
+    if (!extension || !receiverMM) {
+      return Promise.reject({
+        result: MessageChannel.RESULT_NO_HANDLER,
+        message: "No matching message handler for the given recipient.",
+      });
+    }
+
+    if ((messageName == "Extension:Message" ||
+         messageName == "Extension:Connect") &&
+        apiManager.global.tabGetSender) {
+      // From ext-tabs.js, undefined on Android.
+      apiManager.global.tabGetSender(extension, target, sender);
+    }
+    return MessageChannel.sendMessage(receiverMM, messageName, data, {
+      sender,
+      recipient,
+      responseType,
+    });
+  },
+
+  /**
+   * @param {object} recipient An object that was passed to
+   *     `MessageChannel.sendMessage`.
+   * @returns {object|null} The message manager matching the recipient if found.
+   */
+  _getMessageManagerForRecipient(recipient) {
+    let {extensionId, tabId} = recipient;
+    // tabs.sendMessage / tabs.connect
+    if (tabId) {
+      // `tabId` being set implies that the tabs API is supported, so we don't
+      // need to check whether `TabManager` exists.
+      let tab = apiManager.global.TabManager.getTab(tabId, null, null);
+      return tab && tab.linkedBrowser.messageManager;
+    }
+
+    // runtime.sendMessage / runtime.connect
+    if (extensionId) {
+      // TODO(robwu): map the extensionId to the addon parent process's message
+      // manager when they run in a separate process.
+      return Services.ppmm.getChildAt(0);
+    }
+
+    return null;
+  },
+};
+
+// Responsible for loading extension APIs into the right globals.
+GlobalManager = {
+  // Map[extension ID -> Extension]. Determines which extension is
+  // responsible for content under a particular extension ID.
+  extensionMap: new Map(),
+  initialized: false,
+
+  init(extension) {
+    if (this.extensionMap.size == 0) {
+      ProxyMessenger.init();
+      apiManager.on("extension-browser-inserted", this._onExtensionBrowser);
+      this.initialized = true;
+    }
+
+    this.extensionMap.set(extension.id, extension);
+  },
+
+  uninit(extension) {
+    this.extensionMap.delete(extension.id);
+
+    if (this.extensionMap.size == 0 && this.initialized) {
+      apiManager.off("extension-browser-inserted", this._onExtensionBrowser);
+      this.initialized = false;
+    }
+  },
+
+  _onExtensionBrowser(type, browser) {
+    browser.messageManager.loadFrameScript(`data:,
+      Components.utils.import("resource://gre/modules/ExtensionContent.jsm");
+      ExtensionContent.init(this);
+      addEventListener("unload", function() {
+        ExtensionContent.uninit(this);
+      });
+    `, false);
+  },
+
+  getExtension(extensionId) {
+    return this.extensionMap.get(extensionId);
+  },
+
+  injectInObject(context, isChromeCompat, dest) {
+    apiManager.generateAPIs(context, dest);
+    SchemaAPIManager.generateAPIs(context, context.extension.apis, dest);
+  },
+};
+
+/**
+ * The proxied parent side of a context in ExtensionChild.jsm, for the
+ * parent side of a proxied API.
+ */
+class ProxyContextParent extends BaseContext {
+  constructor(envType, extension, params, xulBrowser, principal) {
+    super(envType, extension);
+
+    this.uri = NetUtil.newURI(params.url);
+
+    this.incognito = params.incognito;
+
+    // This message manager is used by ParentAPIManager to send messages and to
+    // close the ProxyContext if the underlying message manager closes. This
+    // message manager object may change when `xulBrowser` swaps docshells, e.g.
+    // when a tab is moved to a different window.
+    this.messageManagerProxy = new MessageManagerProxy(xulBrowser);
+
+    Object.defineProperty(this, "principal", {
+      value: principal, enumerable: true, configurable: true,
+    });
+
+    this.listenerProxies = new Map();
+
+    apiManager.emit("proxy-context-load", this);
+  }
+
+  get cloneScope() {
+    return this.sandbox;
+  }
+
+  get xulBrowser() {
+    return this.messageManagerProxy.eventTarget;
+  }
+
+  get parentMessageManager() {
+    return this.messageManagerProxy.messageManager;
+  }
+
+  shutdown() {
+    this.unload();
+  }
+
+  unload() {
+    if (this.unloaded) {
+      return;
+    }
+    this.messageManagerProxy.dispose();
+    super.unload();
+    apiManager.emit("proxy-context-unload", this);
+  }
+}
+
+defineLazyGetter(ProxyContextParent.prototype, "apiObj", function() {
+  let obj = {};
+  GlobalManager.injectInObject(this, false, obj);
+  return obj;
+});
+
+defineLazyGetter(ProxyContextParent.prototype, "sandbox", function() {
+  return Cu.Sandbox(this.principal);
+});
+
+/**
+ * The parent side of proxied API context for extension content script
+ * running in ExtensionContent.jsm.
+ */
+class ContentScriptContextParent extends ProxyContextParent {
+}
+
+/**
+ * The parent side of proxied API context for extension page, such as a
+ * background script, a tab page, or a popup, running in
+ * ExtensionChild.jsm.
+ */
+class ExtensionPageContextParent extends ProxyContextParent {
+  constructor(envType, extension, params, xulBrowser) {
+    super(envType, extension, params, xulBrowser, extension.principal);
+
+    this.viewType = params.viewType;
+  }
+
+  // The window that contains this context. This may change due to moving tabs.
+  get xulWindow() {
+    return this.xulBrowser.ownerGlobal;
+  }
+
+  get windowId() {
+    if (!apiManager.global.WindowManager || this.viewType == "background") {
+      return;
+    }
+    // viewType popup or tab:
+    return apiManager.global.WindowManager.getId(this.xulWindow);
+  }
+
+  get tabId() {
+    if (!apiManager.global.TabManager) {
+      return;  // Not yet supported on Android.
+    }
+    let {gBrowser} = this.xulBrowser.ownerGlobal;
+    let tab = gBrowser && gBrowser.getTabForBrowser(this.xulBrowser);
+    return tab && apiManager.global.TabManager.getId(tab);
+  }
+
+  onBrowserChange(browser) {
+    super.onBrowserChange(browser);
+    this.xulBrowser = browser;
+  }
+
+  shutdown() {
+    apiManager.emit("page-shutdown", this);
+    super.shutdown();
+  }
+}
+
+ParentAPIManager = {
+  proxyContexts: new Map(),
+
+  init() {
+    Services.obs.addObserver(this, "message-manager-close", false);
+
+    Services.mm.addMessageListener("API:CreateProxyContext", this);
+    Services.mm.addMessageListener("API:CloseProxyContext", this, true);
+    Services.mm.addMessageListener("API:Call", this);
+    Services.mm.addMessageListener("API:AddListener", this);
+    Services.mm.addMessageListener("API:RemoveListener", this);
+  },
+
+  observe(subject, topic, data) {
+    if (topic === "message-manager-close") {
+      let mm = subject;
+      for (let [childId, context] of this.proxyContexts) {
+        if (context.parentMessageManager === mm) {
+          this.closeProxyContext(childId);
+        }
+      }
+    }
+  },
+
+  shutdownExtension(extensionId) {
+    for (let [childId, context] of this.proxyContexts) {
+      if (context.extension.id == extensionId) {
+        context.shutdown();
+        this.proxyContexts.delete(childId);
+      }
+    }
+  },
+
+  receiveMessage({name, data, target}) {
+    switch (name) {
+      case "API:CreateProxyContext":
+        this.createProxyContext(data, target);
+        break;
+
+      case "API:CloseProxyContext":
+        this.closeProxyContext(data.childId);
+        break;
+
+      case "API:Call":
+        this.call(data, target);
+        break;
+
+      case "API:AddListener":
+        this.addListener(data, target);
+        break;
+
+      case "API:RemoveListener":
+        this.removeListener(data);
+        break;
+    }
+  },
+
+  createProxyContext(data, target) {
+    let {envType, extensionId, childId, principal} = data;
+    if (this.proxyContexts.has(childId)) {
+      throw new Error("A WebExtension context with the given ID already exists!");
+    }
+
+    let extension = GlobalManager.getExtension(extensionId);
+    if (!extension) {
+      throw new Error(`No WebExtension found with ID ${extensionId}`);
+    }
+
+    let context;
+    if (envType == "addon_parent") {
+      // Privileged addon contexts can only be loaded in documents whose main
+      // frame is also the same addon.
+      if (principal.URI.prePath !== extension.baseURI.prePath ||
+          !target.contentPrincipal.subsumes(principal)) {
+        throw new Error(`Refused to create privileged WebExtension context for ${principal.URI.spec}`);
+      }
+      context = new ExtensionPageContextParent(envType, extension, data, target);
+    } else if (envType == "content_parent") {
+      context = new ContentScriptContextParent(envType, extension, data, target, principal);
+    } else {
+      throw new Error(`Invalid WebExtension context envType: ${envType}`);
+    }
+    this.proxyContexts.set(childId, context);
+  },
+
+  closeProxyContext(childId) {
+    let context = this.proxyContexts.get(childId);
+    if (context) {
+      context.unload();
+      this.proxyContexts.delete(childId);
+    }
+  },
+
+  call(data, target) {
+    let context = this.getContextById(data.childId);
+    if (context.parentMessageManager !== target.messageManager) {
+      throw new Error("Got message on unexpected message manager");
+    }
+
+    let reply = result => {
+      if (!context.parentMessageManager) {
+        Cu.reportError("Cannot send function call result: other side closed connection");
+        return;
+      }
+
+      context.parentMessageManager.sendAsyncMessage(
+        "API:CallResult",
+        Object.assign({
+          childId: data.childId,
+          callId: data.callId,
+        }, result));
+    };
+
+    try {
+      let args = Cu.cloneInto(data.args, context.sandbox);
+      let result = findPathInObject(context.apiObj, data.path)(...args);
+
+      if (data.callId) {
+        result = result || Promise.resolve();
+
+        result.then(result => {
+          result = result instanceof SpreadArgs ? [...result] : [result];
+
+          reply({result});
+        }, error => {
+          error = context.normalizeError(error);
+          reply({error: {message: error.message}});
+        });
+      }
+    } catch (e) {
+      if (data.callId) {
+        let error = context.normalizeError(e);
+        reply({error: {message: error.message}});
+      } else {
+        Cu.reportError(e);
+      }
+    }
+  },
+
+  addListener(data, target) {
+    let context = this.getContextById(data.childId);
+    if (context.parentMessageManager !== target.messageManager) {
+      throw new Error("Got message on unexpected message manager");
+    }
+
+    let {childId} = data;
+
+    function listener(...listenerArgs) {
+      return context.sendMessage(
+        context.parentMessageManager,
+        "API:RunListener",
+        {
+          childId,
+          listenerId: data.listenerId,
+          path: data.path,
+          args: listenerArgs,
+        },
+        {
+          recipient: {childId},
+        });
+    }
+
+    context.listenerProxies.set(data.listenerId, listener);
+
+    let args = Cu.cloneInto(data.args, context.sandbox);
+    findPathInObject(context.apiObj, data.path).addListener(listener, ...args);
+  },
+
+  removeListener(data) {
+    let context = this.getContextById(data.childId);
+    let listener = context.listenerProxies.get(data.listenerId);
+    findPathInObject(context.apiObj, data.path).removeListener(listener);
+  },
+
+  getContextById(childId) {
+    let context = this.proxyContexts.get(childId);
+    if (!context) {
+      let error = new Error("WebExtension context not found!");
+      Cu.reportError(error);
+      throw error;
+    }
+    return context;
+  },
+};
+
+ParentAPIManager.init();
+
+
+const ExtensionParent = {
+  GlobalManager,
+  ParentAPIManager,
+  apiManager,
+};