Bug 852599 - Block downloads when they are disallowed globally by the parental control service. r=paolo

toolkit/components/jsdownloads/src/DownloadCore.jsm

@@ -54,6 +54,8 @@ const Cr = Components.results;
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
+XPCOMUtils.defineLazyModuleGetter(this, "DownloadIntegration",
+                                  "resource://gre/modules/DownloadIntegration.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
                                   "resource://gre/modules/NetUtil.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "OS",
@@ -269,6 +271,14 @@ Download.prototype = {
         yield this._promiseCanceled;
       }
 
+      // Disallow download if parental controls service restricts it.
+      if (yield DownloadIntegration.shouldBlockForParentalControls(this)) {
+        let error = new DownloadError(Cr.NS_ERROR_FAILURE, "Download blocked.");
+        error.becauseBlocked = true;
+        error.becauseBlockedByParentalControls = true;
+        throw error;
+      }
+
       try {
         // Execute the actual download through the saver object.
         yield this.saver.execute(DS_setProgressBytes.bind(this));
@@ -541,6 +551,18 @@ DownloadError.prototype = {
    * Indicates an error occurred while writing to the local target.
    */
   becauseTargetFailed: false,
+
+  /**
+   * Indicates the download failed because it was blocked.  If the reason for
+   * blocking is known, the corresponding property will be also set.
+   */
+  becauseBlocked: false,
+
+  /**
+   * Indicates the download was blocked because downloads are globally
+   * disallowed by the Parental Controls or Family Safety features on Windows.
+   */
+  becauseBlockedByParentalControls: false,
 };
 
 ////////////////////////////////////////////////////////////////////////////////

toolkit/components/jsdownloads/src/DownloadIntegration.jsm

@@ -30,7 +30,9 @@ XPCOMUtils.defineLazyModuleGetter(this, "DownloadStore",
 XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
                                   "resource://gre/modules/FileUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "OS",
-                                  "resource://gre/modules/osfile.jsm")
+                                  "resource://gre/modules/osfile.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Promise",
+                                  "resource://gre/modules/commonjs/sdk/core/promise.js");
 XPCOMUtils.defineLazyModuleGetter(this, "Services",
                                   "resource://gre/modules/Services.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "Task",
@@ -38,6 +40,14 @@ XPCOMUtils.defineLazyModuleGetter(this, "Task",
 XPCOMUtils.defineLazyServiceGetter(this, "env",
                                    "@mozilla.org/process/environment;1",
                                    "nsIEnvironment");
+XPCOMUtils.defineLazyGetter(this, "gParentalControlsService", function() {
+  if ("@mozilla.org/parental-controls-service;1" in Cc) {
+    return Cc["@mozilla.org/parental-controls-service;1"]
+      .createInstance(Ci.nsIParentalControlsService);
+  }
+  return null;
+});
+
 XPCOMUtils.defineLazyGetter(this, "gStringBundle", function() {
   return Services.strings.
     createBundle("chrome://mozapps/locale/downloads/downloads.properties");
@@ -54,6 +64,8 @@ this.DownloadIntegration = {
   // For testing only
   testMode: false,
   dontLoad: false,
+  dontCheckParentalControls: false,
+  shouldBlockInTest: false,
 
   /**
    * Main DownloadStore object for loading and saving the list of persistent
@@ -182,7 +194,6 @@ this.DownloadIntegration = {
             directory = Services.prefs.getComplexValue("browser.download.dir",
                                                        Ci.nsIFile);
             yield OS.File.makeDir(directory.path, { ignoreExisting: true });
-
           } catch(ex) {
             // Either the preference isn't set or the directory cannot be created.
             directory = yield this.getSystemDownloadsDirectory();
@@ -221,6 +232,34 @@ this.DownloadIntegration = {
     }.bind(this));
   },
 
+  /**
+   * Checks to determine whether to block downloads for parental controls.
+   *
+   * aParam aDownload
+   *        The download object.
+   *
+   * @return {Promise}
+   * @resolves The boolean indicates to block downloads or not.
+   */
+  shouldBlockForParentalControls: function DI_shouldBlockForParentalControls(aDownload) {
+    if (this.dontCheckParentalControls) {
+      return Promise.resolve(this.shouldBlockInTest);
+    }
+
+    let isEnabled = gParentalControlsService &&
+                    gParentalControlsService.parentalControlsEnabled;
+    let shouldBlock = isEnabled &&
+                      gParentalControlsService.blockFileDownloadsEnabled;
+
+    // Log the event if required by parental controls settings.
+    if (isEnabled && gParentalControlsService.loggingEnabled) {
+      gParentalControlsService.log(gParentalControlsService.ePCLog_FileDownload,
+                                   shouldBlock, aDownload.source.uri, null);
+    }
+
+    return Promise.resolve(shouldBlock);
+  },
+
   /**
    * Determines whether it's a Windows Metro app.
    */

toolkit/components/jsdownloads/src/DownloadLegacy.js

@@ -83,6 +83,10 @@ DownloadLegacyTransfer.prototype = {
   onStateChange: function DLT_onStateChange(aWebProgress, aRequest, aStateFlags,
                                             aStatus)
   {
+    if (!Components.isSuccessCode(aStatus)) {
+      this._componentFailed = true;
+    }
+
     // Detect when the last file has been received, or the download failed.
     if ((aStateFlags & Ci.nsIWebProgressListener.STATE_STOP) &&
         (aStateFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK)) {
@@ -113,6 +117,8 @@ DownloadLegacyTransfer.prototype = {
     // change, but if no network request actually started, it is possible that
     // we only receive a status change with an error status code.
     if (!Components.isSuccessCode(aStatus)) {
+      this._componentFailed = true;
+
       // Wait for the associated Download object to be available.
       this._deferDownload.promise.then(function DLT_OSC_onDownload(aDownload) {
         aDownload.saver.onTransferFinished(aRequest, aStatus);
@@ -160,12 +166,18 @@ DownloadLegacyTransfer.prototype = {
       saver: { type: "legacy" },
     }).then(function DLT_I_onDownload(aDownload) {
       // Now that the saver is available, hook up the cancellation handler.
-      aDownload.saver.deferCanceled.promise
+      aDownload.saver.deferCanceled.promise.then(() => {
-                     .then(function () aCancelable.cancel(Cr.NS_ERROR_ABORT))
+        // Only cancel if the object executing the download is still running.
-                     .then(null, Cu.reportError);
+        if (!this._componentFailed) {
+          aCancelable.cancel(Cr.NS_ERROR_ABORT);
+        }
+      }).then(null, Cu.reportError);
 
       // Start the download before allowing it to be controlled.
-      aDownload.start();
+      aDownload.start().then(null, function () {
+        // In case the operation failed, ensure we stop downloading data.
+        aDownload.saver.deferCanceled.resolve();
+      });
 
       // Start processing all the other events received through nsITransfer.
       this._deferDownload.resolve(aDownload);
@@ -189,6 +201,13 @@ DownloadLegacyTransfer.prototype = {
    * object associated with this nsITransfer instance, when it is available.
    */
   _deferDownload: null,
+
+  /**
+   * Indicates that the component that executes the download has notified a
+   * failure condition.  In this case, we should never use the component methods
+   * that cancel the download.
+   */
+  _componentFailed: false,
 };
 
 ////////////////////////////////////////////////////////////////////////////////

toolkit/components/jsdownloads/test/unit/head.js

@@ -451,4 +451,6 @@ add_task(function test_common_initialize()
 
   // Disable integration with the host application requiring profile access.
   DownloadIntegration.dontLoad = true;
+  // Disable the parental controls checking.
+  DownloadIntegration.dontCheckParentalControls = true;
 });

toolkit/components/jsdownloads/test/unit/test_DownloadCore.js

@@ -873,3 +873,25 @@ add_task(function test_download_cancel_midway_restart_with_content_encoding()
   yield promiseVerifyContents(download.target.file, TEST_DATA_SHORT);
 });
 
+/**
+ * Download with parental controls enabled.
+ */
+add_task(function test_download_blocked_parental_controls()
+{
+  function cleanup() {
+    DownloadIntegration.shouldBlockInTest = false;
+  }
+  do_register_cleanup(cleanup);
+  DownloadIntegration.shouldBlockInTest = true;
+
+  let download = yield promiseSimpleDownload();
+
+  try {
+    yield download.start();
+    do_throw("The download should have blocked.");
+  } catch (ex if ex instanceof Downloads.Error && ex.becauseBlocked) {
+    do_check_true(ex.becauseBlockedByParentalControls);
+  }
+  cleanup();
+});
+

toolkit/components/jsdownloads/test/unit/test_DownloadIntegration.js

@@ -125,7 +125,6 @@ add_task(function test_getUserDownloadsDirectory()
   cleanup();
 });
 
-
 /**
  * Tests that the getTemporaryDownloadsDirectory returns a valid nsFile 
  * download directory object.

toolkit/components/jsdownloads/test/unit/test_DownloadLegacy.js

@@ -353,3 +353,27 @@ add_task(function test_download_public_and_private()
   cleanup();
 });
 
+/**
+ * Download with parental controls enabled.
+ */
+add_task(function test_download_blocked_parental_controls()
+{
+  function cleanup() {
+    DownloadIntegration.shouldBlockInTest = false;
+  }
+  do_register_cleanup(cleanup);
+  DownloadIntegration.shouldBlockInTest = true;
+
+  let download = yield promiseStartLegacyDownload();
+
+  try {
+    yield download.start();
+    do_throw("The download should have blocked.");
+  } catch (ex if ex instanceof Downloads.Error && ex.becauseBlocked) {
+    do_check_true(ex.becauseBlockedByParentalControls);
+  }
+
+  do_check_false(download.target.file.exists());
+
+  cleanup();
+});