1 files changed, 499 insertions, 0 deletions
diff --git a/browser/components/shell/ShellService.sys.mjs b/browser/components/shell/ShellService.sys.mjs
new file mode 100644
index 0000000000..c4af0be7de
--- /dev/null
+++ b/browser/components/shell/ShellService.sys.mjs
@@ -0,0 +1,499 @@
+/* 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 { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  NimbusFeatures: "resource://nimbus/ExperimentAPI.sys.mjs",
+});
+
+XPCOMUtils.defineLazyServiceGetter(
+  lazy,
+  "XreDirProvider",
+  "@mozilla.org/xre/directory-provider;1",
+  "nsIXREDirProvider"
+);
+
+ChromeUtils.defineLazyGetter(lazy, "log", () => {
+  let { ConsoleAPI } = ChromeUtils.importESModule(
+    "resource://gre/modules/Console.sys.mjs"
+  );
+  let consoleOptions = {
+    // tip: set maxLogLevel to "debug" and use log.debug() to create detailed
+    // messages during development. See LOG_LEVELS in Console.sys.mjs for details.
+    maxLogLevel: "error",
+    maxLogLevelPref: "browser.shell.loglevel",
+    prefix: "ShellService",
+  };
+  return new ConsoleAPI(consoleOptions);
+});
+
+/**
+ * Internal functionality to save and restore the docShell.allow* properties.
+ */
+let ShellServiceInternal = {
+  /**
+   * Used to determine whether or not to offer "Set as desktop background"
+   * functionality. Even if shell service is available it is not
+   * guaranteed that it is able to set the background for every desktop
+   * which is especially true for Linux with its many different desktop
+   * environments.
+   */
+  get canSetDesktopBackground() {
+    if (AppConstants.platform == "win" || AppConstants.platform == "macosx") {
+      return true;
+    }
+
+    if (AppConstants.platform == "linux") {
+      if (this.shellService) {
+        let linuxShellService = this.shellService.QueryInterface(
+          Ci.nsIGNOMEShellService
+        );
+        return linuxShellService.canSetDesktopBackground;
+      }
+    }
+
+    return false;
+  },
+
+  /**
+   * Used to determine whether or not to show a "Set Default Browser"
+   * query dialog. This attribute is true if the application is starting
+   * up and "browser.shell.checkDefaultBrowser" is true, otherwise it
+   * is false.
+   */
+  _checkedThisSession: false,
+  get shouldCheckDefaultBrowser() {
+    // If we've already checked, the browser has been started and this is a
+    // new window open, and we don't want to check again.
+    if (this._checkedThisSession) {
+      return false;
+    }
+
+    if (!Services.prefs.getBoolPref("browser.shell.checkDefaultBrowser")) {
+      return false;
+    }
+
+    return true;
+  },
+
+  set shouldCheckDefaultBrowser(shouldCheck) {
+    Services.prefs.setBoolPref(
+      "browser.shell.checkDefaultBrowser",
+      !!shouldCheck
+    );
+  },
+
+  isDefaultBrowser(startupCheck, forAllTypes) {
+    // If this is the first browser window, maintain internal state that we've
+    // checked this session (so that subsequent window opens don't show the
+    // default browser dialog).
+    if (startupCheck) {
+      this._checkedThisSession = true;
+    }
+    if (this.shellService) {
+      return this.shellService.isDefaultBrowser(forAllTypes);
+    }
+    return false;
+  },
+
+  /*
+   * Check if UserChoice is impossible.
+   *
+   * Separated for easy stubbing in tests.
+   *
+   * @return string telemetry result like "Err*", or null if UserChoice
+   * is possible.
+   */
+  _userChoiceImpossibleTelemetryResult() {
+    if (!ShellService.checkAllProgIDsExist()) {
+      return "ErrProgID";
+    }
+    if (!ShellService.checkBrowserUserChoiceHashes()) {
+      return "ErrHash";
+    }
+    return null;
+  },
+
+  /*
+   * Accommodate `setDefaultPDFHandlerOnlyReplaceBrowsers` feature.
+   * @return true if Firefox should set itself as default PDF handler, false
+   * otherwise.
+   */
+  _shouldSetDefaultPDFHandler() {
+    if (
+      !lazy.NimbusFeatures.shellService.getVariable(
+        "setDefaultPDFHandlerOnlyReplaceBrowsers"
+      )
+    ) {
+      return true;
+    }
+
+    const handler = this.getDefaultPDFHandler();
+    if (handler === null) {
+      // We only get an exception when something went really wrong.  Fail
+      // safely: don't set Firefox as default PDF handler.
+      lazy.log.warn(
+        "Could not determine default PDF handler: not setting Firefox as " +
+          "default PDF handler!"
+      );
+      return false;
+    }
+
+    if (!handler.registered) {
+      lazy.log.debug(
+        "Current default PDF handler has no registered association; " +
+          "should set as default PDF handler."
+      );
+      return true;
+    }
+
+    if (handler.knownBrowser) {
+      lazy.log.debug(
+        "Current default PDF handler progID matches known browser; should " +
+          "set as default PDF handler."
+      );
+      return true;
+    }
+
+    lazy.log.debug(
+      "Current default PDF handler progID does not match known browser " +
+        "prefix; should not set as default PDF handler."
+    );
+    return false;
+  },
+
+  getDefaultPDFHandler() {
+    const knownBrowserPrefixes = [
+      "AppXq0fevzme2pys62n3e0fbqa7peapykr8v", // Edge before Blink, per https://stackoverflow.com/a/32724723.
+      "AppXd4nrz8ff68srnhf9t5a8sbjyar1cr723", // Another pre-Blink Edge identifier. See Bug 1858729.
+      "Brave", // For "BraveFile".
+      "Chrome", // For "ChromeHTML".
+      "Firefox", // For "FirefoxHTML-*" or "FirefoxPDF-*".  Need to take from other installations of Firefox!
+      "IE", // Best guess.
+      "MSEdge", // For "MSEdgePDF".  Edgium.
+      "Opera", // For "OperaStable", presumably varying with channel.
+      "Yandex", // For "YandexPDF.IHKFKZEIOKEMR6BGF62QXCRIKM", presumably varying with installation.
+    ];
+
+    let currentProgID = "";
+    try {
+      // Returns the empty string when no association is registered, in
+      // which case the prefix matching will fail and we'll set Firefox as
+      // the default PDF handler.
+      currentProgID = this.queryCurrentDefaultHandlerFor(".pdf");
+    } catch (e) {
+      // We only get an exception when something went really wrong.  Fail
+      // safely: don't set Firefox as default PDF handler.
+      lazy.log.warn("Failed to queryCurrentDefaultHandlerFor:");
+      return null;
+    }
+
+    if (currentProgID == "") {
+      return { registered: false, knownBrowser: false };
+    }
+
+    const knownBrowserPrefix = knownBrowserPrefixes.find(it =>
+      currentProgID.startsWith(it)
+    );
+
+    if (knownBrowserPrefix) {
+      lazy.log.debug(`Found known browser prefix: ${knownBrowserPrefix}`);
+    }
+
+    return {
+      registered: true,
+      knownBrowser: !!knownBrowserPrefix,
+    };
+  },
+
+  /*
+   * Set the default browser through the UserChoice registry keys on Windows.
+   *
+   * NOTE: This does NOT open the System Settings app for manual selection
+   * in case of failure. If that is desired, catch the exception and call
+   * setDefaultBrowser().
+   *
+   * @return Promise, resolves when successful, rejects with Error on failure.
+   */
+  async setAsDefaultUserChoice() {
+    if (AppConstants.platform != "win") {
+      throw new Error("Windows-only");
+    }
+
+    lazy.log.info("Setting Firefox as default using UserChoice");
+
+    let telemetryResult = "ErrOther";
+
+    try {
+      telemetryResult =
+        this._userChoiceImpossibleTelemetryResult() ?? "ErrOther";
+      if (telemetryResult == "ErrProgID") {
+        throw new Error("checkAllProgIDsExist() failed");
+      }
+      if (telemetryResult == "ErrHash") {
+        throw new Error("checkBrowserUserChoiceHashes() failed");
+      }
+
+      const aumi = lazy.XreDirProvider.getInstallHash();
+
+      telemetryResult = "ErrLaunchExe";
+      const extraFileExtensions = [];
+      if (
+        lazy.NimbusFeatures.shellService.getVariable("setDefaultPDFHandler")
+      ) {
+        if (this._shouldSetDefaultPDFHandler()) {
+          lazy.log.info("Setting Firefox as default PDF handler");
+          extraFileExtensions.push(".pdf", "FirefoxPDF");
+        } else {
+          lazy.log.info("Not setting Firefox as default PDF handler");
+        }
+      }
+      try {
+        await this.defaultAgent.setDefaultBrowserUserChoiceAsync(
+          aumi,
+          extraFileExtensions
+        );
+      } catch (err) {
+        telemetryResult = "ErrOther";
+        this._handleWDBAResult(err.result || Cr.NS_ERROR_FAILURE);
+      }
+      telemetryResult = "Success";
+    } catch (ex) {
+      if (ex instanceof WDBAError) {
+        telemetryResult = ex.telemetryResult;
+      }
+
+      throw ex;
+    } finally {
+      try {
+        const histogram = Services.telemetry.getHistogramById(
+          "BROWSER_SET_DEFAULT_USER_CHOICE_RESULT"
+        );
+        histogram.add(telemetryResult);
+      } catch (ex) {}
+    }
+  },
+
+  async setAsDefaultPDFHandlerUserChoice() {
+    if (AppConstants.platform != "win") {
+      throw new Error("Windows-only");
+    }
+
+    let telemetryResult = "ErrOther";
+
+    try {
+      const aumi = lazy.XreDirProvider.getInstallHash();
+      try {
+        this.defaultAgent.setDefaultExtensionHandlersUserChoice(aumi, [
+          ".pdf",
+          "FirefoxPDF",
+        ]);
+      } catch (err) {
+        telemetryResult = "ErrOther";
+        this._handleWDBAResult(err.result || Cr.NS_ERROR_FAILURE);
+      }
+      telemetryResult = "Success";
+    } catch (ex) {
+      if (ex instanceof WDBAError) {
+        telemetryResult = ex.telemetryResult;
+      }
+
+      throw ex;
+    } finally {
+      try {
+        const histogram = Services.telemetry.getHistogramById(
+          "BROWSER_SET_DEFAULT_PDF_HANDLER_USER_CHOICE_RESULT"
+        );
+        histogram.add(telemetryResult);
+      } catch (ex) {}
+    }
+  },
+
+  // override nsIShellService.setDefaultBrowser() on the ShellService proxy.
+  async setDefaultBrowser(forAllUsers) {
+    // On Windows, our best chance is to set UserChoice, so try that first.
+    if (
+      AppConstants.platform == "win" &&
+      lazy.NimbusFeatures.shellService.getVariable(
+        "setDefaultBrowserUserChoice"
+      )
+    ) {
+      try {
+        await this.setAsDefaultUserChoice();
+        return;
+      } catch (err) {
+        lazy.log.warn(
+          "Error thrown during setAsDefaultUserChoice. Full exception:",
+          err
+        );
+
+        // intentionally fall through to setting via the non-user choice pathway on error
+      }
+    }
+
+    this.shellService.setDefaultBrowser(forAllUsers);
+  },
+
+  async setAsDefault() {
+    let setAsDefaultError = false;
+    try {
+      await ShellService.setDefaultBrowser(false);
+    } catch (ex) {
+      setAsDefaultError = true;
+      console.error(ex);
+    }
+    // Here BROWSER_IS_USER_DEFAULT and BROWSER_SET_USER_DEFAULT_ERROR appear
+    // to be inverse of each other, but that is only because this function is
+    // called when the browser is set as the default. During startup we record
+    // the BROWSER_IS_USER_DEFAULT value without recording BROWSER_SET_USER_DEFAULT_ERROR.
+    Services.telemetry
+      .getHistogramById("BROWSER_IS_USER_DEFAULT")
+      .add(!setAsDefaultError);
+    Services.telemetry
+      .getHistogramById("BROWSER_SET_DEFAULT_ERROR")
+      .add(setAsDefaultError);
+  },
+
+  setAsDefaultPDFHandler(onlyIfKnownBrowser = false) {
+    if (onlyIfKnownBrowser && !this.getDefaultPDFHandler().knownBrowser) {
+      return;
+    }
+
+    if (AppConstants.platform == "win") {
+      this.setAsDefaultPDFHandlerUserChoice();
+    }
+  },
+
+  /**
+   * Determine if we're the default handler for the given file extension (like
+   * ".pdf") or protocol (like "https").  Windows-only for now.
+   *
+   * @returns {boolean} true if we are the default handler, false otherwise.
+   */
+  isDefaultHandlerFor(aFileExtensionOrProtocol) {
+    if (AppConstants.platform == "win") {
+      return this.shellService
+        .QueryInterface(Ci.nsIWindowsShellService)
+        .isDefaultHandlerFor(aFileExtensionOrProtocol);
+    }
+    return false;
+  },
+
+  /**
+   * Checks if Firefox app can and isn't pinned to OS "taskbar."
+   *
+   * @throws if not called from main process.
+   */
+  async doesAppNeedPin(privateBrowsing = false) {
+    if (
+      Services.appinfo.processType !== Services.appinfo.PROCESS_TYPE_DEFAULT
+    ) {
+      throw new Components.Exception(
+        "Can't determine pinned from child process",
+        Cr.NS_ERROR_NOT_AVAILABLE
+      );
+    }
+
+    // Pretend pinning is not needed/supported if remotely disabled.
+    if (lazy.NimbusFeatures.shellService.getVariable("disablePin")) {
+      return false;
+    }
+
+    // Currently this only works on certain Windows versions.
+    try {
+      // First check if we can even pin the app where an exception means no.
+      await this.shellService
+        .QueryInterface(Ci.nsIWindowsShellService)
+        .checkPinCurrentAppToTaskbarAsync(privateBrowsing);
+      let winTaskbar = Cc["@mozilla.org/windows-taskbar;1"].getService(
+        Ci.nsIWinTaskbar
+      );
+
+      // Then check if we're already pinned.
+      return !(await this.shellService.isCurrentAppPinnedToTaskbarAsync(
+        privateBrowsing
+          ? winTaskbar.defaultPrivateGroupId
+          : winTaskbar.defaultGroupId
+      ));
+    } catch (ex) {}
+
+    // Next check mac pinning to dock.
+    try {
+      // Accessing this.macDockSupport will ensure we're actually running
+      // on Mac (it's possible to be on Linux in this block).
+      const isInDock = this.macDockSupport.isAppInDock;
+      // We can't pin Private Browsing mode on Mac, only a shortcut to the vanilla app
+      return privateBrowsing ? false : !isInDock;
+    } catch (ex) {}
+    return false;
+  },
+
+  /**
+   * Pin Firefox app to the OS "taskbar."
+   */
+  async pinToTaskbar(privateBrowsing = false) {
+    if (await this.doesAppNeedPin(privateBrowsing)) {
+      try {
+        if (AppConstants.platform == "win") {
+          await this.shellService.pinCurrentAppToTaskbarAsync(privateBrowsing);
+        } else if (AppConstants.platform == "macosx") {
+          this.macDockSupport.ensureAppIsPinnedToDock();
+        }
+      } catch (ex) {
+        console.error(ex);
+      }
+    }
+  },
+
+  _handleWDBAResult(exitCode) {
+    if (exitCode != Cr.NS_OK) {
+      const telemetryResult =
+        new Map([
+          [Cr.NS_ERROR_WDBA_NO_PROGID, "ErrExeProgID"],
+          [Cr.NS_ERROR_WDBA_HASH_CHECK, "ErrExeHash"],
+          [Cr.NS_ERROR_WDBA_REJECTED, "ErrExeRejected"],
+          [Cr.NS_ERROR_WDBA_BUILD, "ErrBuild"],
+        ]).get(exitCode) ?? "ErrExeOther";
+
+      throw new WDBAError(exitCode, telemetryResult);
+    }
+  },
+};
+
+XPCOMUtils.defineLazyServiceGetters(ShellServiceInternal, {
+  defaultAgent: ["@mozilla.org/default-agent;1", "nsIDefaultAgent"],
+  shellService: ["@mozilla.org/browser/shell-service;1", "nsIShellService"],
+  macDockSupport: ["@mozilla.org/widget/macdocksupport;1", "nsIMacDockSupport"],
+});
+
+/**
+ * The external API exported by this module.
+ */
+export var ShellService = new Proxy(ShellServiceInternal, {
+  get(target, name) {
+    if (name in target) {
+      return target[name];
+    }
+    if (target.shellService) {
+      return target.shellService[name];
+    }
+    Services.console.logStringMessage(
+      `${name} not found in ShellService: ${target.shellService}`
+    );
+    return undefined;
+  },
+});
+
+class WDBAError extends Error {
+  constructor(exitCode, telemetryResult) {
+    super(`WDBA nonzero exit code ${exitCode}: ${telemetryResult}`);
+
+    this.exitCode = exitCode;
+    this.telemetryResult = telemetryResult;
+  }
+}