1 files changed, 462 insertions, 0 deletions
diff --git a/remote/marionette/server.sys.mjs b/remote/marionette/server.sys.mjs
new file mode 100644
index 0000000000..49d8055ea6
--- /dev/null
+++ b/remote/marionette/server.sys.mjs
@@ -0,0 +1,462 @@
+/* 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/. */
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  assert: "chrome://remote/content/shared/webdriver/Assert.sys.mjs",
+  Command: "chrome://remote/content/marionette/message.sys.mjs",
+  DebuggerTransport: "chrome://remote/content/marionette/transport.sys.mjs",
+  error: "chrome://remote/content/shared/webdriver/Errors.sys.mjs",
+  GeckoDriver: "chrome://remote/content/marionette/driver.sys.mjs",
+  Log: "chrome://remote/content/shared/Log.sys.mjs",
+  MarionettePrefs: "chrome://remote/content/marionette/prefs.sys.mjs",
+  Message: "chrome://remote/content/marionette/message.sys.mjs",
+  PollPromise: "chrome://remote/content/shared/Sync.sys.mjs",
+  Response: "chrome://remote/content/marionette/message.sys.mjs",
+});
+
+XPCOMUtils.defineLazyGetter(lazy, "logger", () =>
+  lazy.Log.get(lazy.Log.TYPES.MARIONETTE)
+);
+XPCOMUtils.defineLazyGetter(lazy, "ServerSocket", () => {
+  return Components.Constructor(
+    "@mozilla.org/network/server-socket;1",
+    "nsIServerSocket",
+    "initSpecialConnection"
+  );
+});
+
+const { KeepWhenOffline, LoopbackOnly } = Ci.nsIServerSocket;
+
+const PROTOCOL_VERSION = 3;
+
+/**
+ * Bootstraps Marionette and handles incoming client connections.
+ *
+ * Starting the Marionette server will open a TCP socket sporting the
+ * debugger transport interface on the provided `port`.  For every
+ * new connection, a {@link TCPConnection} is created.
+ */
+export class TCPListener {
+  /**
+   * @param {number} port
+   *     Port for server to listen to.
+   */
+  constructor(port) {
+    this.port = port;
+    this.socket = null;
+    this.conns = new Set();
+    this.nextConnID = 0;
+    this.alive = false;
+  }
+
+  /**
+   * Function produces a {@link GeckoDriver}.
+   *
+   * Determines the application to initialise the driver with.
+   *
+   * @returns {GeckoDriver}
+   *     A driver instance.
+   */
+  driverFactory() {
+    return new lazy.GeckoDriver(this);
+  }
+
+  async setAcceptConnections(value) {
+    if (value) {
+      if (!this.socket) {
+        await lazy.PollPromise(
+          (resolve, reject) => {
+            try {
+              const flags = KeepWhenOffline | LoopbackOnly;
+              const backlog = 1;
+              this.socket = new lazy.ServerSocket(this.port, flags, backlog);
+              resolve();
+            } catch (e) {
+              lazy.logger.debug(
+                `Could not bind to port ${this.port} (${e.name})`
+              );
+              reject();
+            }
+          },
+          { interval: 250, timeout: 5000 }
+        );
+
+        // Since PollPromise doesn't throw when timeout expires,
+        // we can end up in the situation when the socket is undefined.
+        if (!this.socket) {
+          throw new Error(`Could not bind to port ${this.port}`);
+        }
+
+        this.port = this.socket.port;
+
+        this.socket.asyncListen(this);
+        lazy.logger.info(`Listening on port ${this.port}`);
+      }
+    } else if (this.socket) {
+      // Note that closing the server socket will not close currently active
+      // connections.
+      this.socket.close();
+      this.socket = null;
+      lazy.logger.info(`Stopped listening on port ${this.port}`);
+    }
+  }
+
+  /**
+   * Bind this listener to {@link #port} and start accepting incoming
+   * socket connections on {@link #onSocketAccepted}.
+   *
+   * The marionette.port preference will be populated with the value
+   * of {@link #port}.
+   */
+  async start() {
+    if (this.alive) {
+      return;
+    }
+
+    // Start socket server and listening for connection attempts
+    await this.setAcceptConnections(true);
+    lazy.MarionettePrefs.port = this.port;
+    this.alive = true;
+  }
+
+  async stop() {
+    if (!this.alive) {
+      return;
+    }
+
+    // Shutdown server socket, and no longer listen for new connections
+    await this.setAcceptConnections(false);
+    this.alive = false;
+  }
+
+  onSocketAccepted(serverSocket, clientSocket) {
+    let input = clientSocket.openInputStream(0, 0, 0);
+    let output = clientSocket.openOutputStream(0, 0, 0);
+    let transport = new lazy.DebuggerTransport(input, output);
+
+    // Only allow a single active WebDriver session at a time
+    const hasActiveSession = [...this.conns].find(
+      conn => !!conn.driver.currentSession
+    );
+    if (hasActiveSession) {
+      lazy.logger.warn(
+        "Connection attempt denied because an active session has been found"
+      );
+
+      // Ideally we should stop the server to listen for new connection
+      // attempts, but the current architecture doesn't allow us to do that.
+      // As such just close the transport if no further connections are allowed.
+      transport.close();
+      return;
+    }
+
+    let conn = new TCPConnection(
+      this.nextConnID++,
+      transport,
+      this.driverFactory.bind(this)
+    );
+    conn.onclose = this.onConnectionClosed.bind(this);
+    this.conns.add(conn);
+
+    lazy.logger.debug(
+      `Accepted connection ${conn.id} ` +
+        `from ${clientSocket.host}:${clientSocket.port}`
+    );
+    conn.sayHello();
+    transport.ready();
+  }
+
+  onConnectionClosed(conn) {
+    lazy.logger.debug(`Closed connection ${conn.id}`);
+    this.conns.delete(conn);
+  }
+}
+
+/**
+ * Marionette client connection.
+ *
+ * Dispatches packets received to their correct service destinations
+ * and sends back the service endpoint's return values.
+ *
+ * @param {number} connID
+ *     Unique identifier of the connection this dispatcher should handle.
+ * @param {DebuggerTransport} transport
+ *     Debugger transport connection to the client.
+ * @param {function(): GeckoDriver} driverFactory
+ *     Factory function that produces a {@link GeckoDriver}.
+ */
+export class TCPConnection {
+  constructor(connID, transport, driverFactory) {
+    this.id = connID;
+    this.conn = transport;
+
+    // transport hooks are TCPConnection#onPacket
+    // and TCPConnection#onClosed
+    this.conn.hooks = this;
+
+    // callback for when connection is closed
+    this.onclose = null;
+
+    // last received/sent message ID
+    this.lastID = 0;
+
+    this.driver = driverFactory();
+  }
+
+  #log(msg) {
+    let dir = msg.origin == lazy.Message.Origin.Client ? "->" : "<-";
+    lazy.logger.debug(`${this.id} ${dir} ${msg.toString()}`);
+  }
+
+  /**
+   * Debugger transport callback that cleans up
+   * after a connection is closed.
+   */
+  onClosed() {
+    this.driver.deleteSession();
+    if (this.onclose) {
+      this.onclose(this);
+    }
+  }
+
+  /**
+   * Callback that receives data packets from the client.
+   *
+   * If the message is a Response, we look up the command previously
+   * issued to the client and run its callback, if any.  In case of
+   * a Command, the corresponding is executed.
+   *
+   * @param {Array.<number, number, ?, ?>} data
+   *     A four element array where the elements, in sequence, signifies
+   *     message type, message ID, method name or error, and parameters
+   *     or result.
+   */
+  onPacket(data) {
+    // unable to determine how to respond
+    if (!Array.isArray(data)) {
+      let e = new TypeError(
+        "Unable to unmarshal packet data: " + JSON.stringify(data)
+      );
+      lazy.error.report(e);
+      return;
+    }
+
+    // return immediately with any error trying to unmarshal message
+    let msg;
+    try {
+      msg = lazy.Message.fromPacket(data);
+      msg.origin = lazy.Message.Origin.Client;
+      this.#log(msg);
+    } catch (e) {
+      let resp = this.createResponse(data[1]);
+      resp.sendError(e);
+      return;
+    }
+
+    // execute new command
+    if (msg instanceof lazy.Command) {
+      (async () => {
+        await this.execute(msg);
+      })();
+    } else {
+      lazy.logger.fatal("Cannot process messages other than Command");
+    }
+  }
+
+  /**
+   * Executes a Marionette command and sends back a response when it
+   * has finished executing.
+   *
+   * If the command implementation sends the response itself by calling
+   * <code>resp.send()</code>, the response is guaranteed to not be
+   * sent twice.
+   *
+   * Errors thrown in commands are marshaled and sent back, and if they
+   * are not {@link WebDriverError} instances, they are additionally
+   * propagated and reported to {@link Components.utils.reportError}.
+   *
+   * @param {Command} cmd
+   *     Command to execute.
+   */
+  async execute(cmd) {
+    let resp = this.createResponse(cmd.id);
+    let sendResponse = () => resp.sendConditionally(resp => !resp.sent);
+    let sendError = resp.sendError.bind(resp);
+
+    await this.despatch(cmd, resp)
+      .then(sendResponse, sendError)
+      .catch(lazy.error.report);
+  }
+
+  /**
+   * Despatches command to appropriate Marionette service.
+   *
+   * @param {Command} cmd
+   *     Command to run.
+   * @param {Response} resp
+   *     Mutable response where the command's return value will be
+   *     assigned.
+   *
+   * @throws {Error}
+   *     A command's implementation may throw at any time.
+   */
+  async despatch(cmd, resp) {
+    const startTime = Cu.now();
+
+    let fn = this.driver.commands[cmd.name];
+    if (typeof fn == "undefined") {
+      throw new lazy.error.UnknownCommandError(cmd.name);
+    }
+
+    if (cmd.name != "WebDriver:NewSession") {
+      lazy.assert.session(this.driver.currentSession);
+    }
+
+    let rv = await fn.bind(this.driver)(cmd);
+
+    // Bug 1819029: Some older commands cannot return a response wrapped within
+    // a value field because it would break compatibility with geckodriver and
+    // Marionette client. It's unlikely that we are going to fix that.
+    //
+    // Warning: No more commands should be added to this list!
+    const commandsNoValueResponse = [
+      "Marionette:Quit",
+      "WebDriver:FindElements",
+      "WebDriver:FindElementsFromShadowRoot",
+      "WebDriver:CloseChromeWindow",
+      "WebDriver:CloseWindow",
+      "WebDriver:FullscreenWindow",
+      "WebDriver:GetCookies",
+      "WebDriver:GetElementRect",
+      "WebDriver:GetTimeouts",
+      "WebDriver:GetWindowHandles",
+      "WebDriver:GetWindowRect",
+      "WebDriver:MaximizeWindow",
+      "WebDriver:MinimizeWindow",
+      "WebDriver:NewSession",
+      "WebDriver:NewWindow",
+      "WebDriver:SetWindowRect",
+    ];
+
+    if (rv != null) {
+      // By default the Response' constructor sets the body to `{ value: null }`.
+      // As such we only want to override the value if it's neither `null` nor
+      // `undefined`.
+      if (commandsNoValueResponse.includes(cmd.name)) {
+        resp.body = rv;
+      } else {
+        resp.body.value = rv;
+      }
+    }
+
+    if (Services.profiler?.IsActive()) {
+      ChromeUtils.addProfilerMarker(
+        "Marionette: Command",
+        { startTime, category: "Remote-Protocol" },
+        `${cmd.name} (${cmd.id})`
+      );
+    }
+  }
+
+  /**
+   * Fail-safe creation of a new instance of {@link Response}.
+   *
+   * @param {number} msgID
+   *     Message ID to respond to.  If it is not a number, -1 is used.
+   *
+   * @returns {Response}
+   *     Response to the message with `msgID`.
+   */
+  createResponse(msgID) {
+    if (typeof msgID != "number") {
+      msgID = -1;
+    }
+    return new lazy.Response(msgID, this.send.bind(this));
+  }
+
+  sendError(err, cmdID) {
+    let resp = new lazy.Response(cmdID, this.send.bind(this));
+    resp.sendError(err);
+  }
+
+  /**
+   * When a client connects we send across a JSON Object defining the
+   * protocol level.
+   *
+   * This is the only message sent by Marionette that does not follow
+   * the regular message format.
+   */
+  sayHello() {
+    let whatHo = {
+      applicationType: "gecko",
+      marionetteProtocol: PROTOCOL_VERSION,
+    };
+    this.sendRaw(whatHo);
+  }
+
+  /**
+   * Delegates message to client based on the provided  {@code cmdID}.
+   * The message is sent over the debugger transport socket.
+   *
+   * The command ID is a unique identifier assigned to the client's request
+   * that is used to distinguish the asynchronous responses.
+   *
+   * Whilst responses to commands are synchronous and must be sent in the
+   * correct order.
+   *
+   * @param {Message} msg
+   *     The command or response to send.
+   */
+  send(msg) {
+    msg.origin = lazy.Message.Origin.Server;
+    if (msg instanceof lazy.Response) {
+      this.sendToClient(msg);
+    } else {
+      lazy.logger.fatal("Cannot send messages other than Response");
+    }
+  }
+
+  // Low-level methods:
+
+  /**
+   * Send given response to the client over the debugger transport socket.
+   *
+   * @param {Response} resp
+   *     The response to send back to the client.
+   */
+  sendToClient(resp) {
+    this.sendMessage(resp);
+  }
+
+  /**
+   * Marshal message to the Marionette message format and send it.
+   *
+   * @param {Message} msg
+   *     The message to send.
+   */
+  sendMessage(msg) {
+    this.#log(msg);
+    let payload = msg.toPacket();
+    this.sendRaw(payload);
+  }
+
+  /**
+   * Send the given payload over the debugger transport socket to the
+   * connected client.
+   *
+   * @param {Object<string, ?>} payload
+   *     The payload to ship.
+   */
+  sendRaw(payload) {
+    this.conn.send(payload);
+  }
+
+  toString() {
+    return `[object TCPConnection ${this.id}]`;
+  }
+}