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Diffstat (limited to 'browser/components/downloads/DownloadSpamProtection.sys.mjs')
| -rw-r--r-- | browser/components/downloads/DownloadSpamProtection.sys.mjs | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/browser/components/downloads/DownloadSpamProtection.sys.mjs b/browser/components/downloads/DownloadSpamProtection.sys.mjs new file mode 100644 index 0000000000..fa0cb97476 --- /dev/null +++ b/browser/components/downloads/DownloadSpamProtection.sys.mjs @@ -0,0 +1,300 @@ +/* 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/. */ + +/** + * Provides functions to prevent multiple automatic downloads. + */ + +import { + Download, + DownloadError, +} from "resource://gre/modules/DownloadCore.sys.mjs"; + +import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs"; + +const lazy = {}; + +ChromeUtils.defineESModuleGetters(lazy, { + DownloadList: "resource://gre/modules/DownloadList.sys.mjs", + Downloads: "resource://gre/modules/Downloads.sys.mjs", + DownloadsCommon: "resource:///modules/DownloadsCommon.sys.mjs", +}); + +XPCOMUtils.defineLazyModuleGetters(lazy, { + BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm", +}); + +/** + * Each window tracks download spam independently, so one of these objects is + * constructed for each window. This is responsible for tracking the spam and + * updating the window's downloads UI accordingly. + */ +class WindowSpamProtection { + constructor(window) { + this._window = window; + } + + /** + * This map stores blocked spam downloads for the window, keyed by the + * download's source URL. This is done so we can track the number of times a + * given download has been blocked. + * @type {Map<String, DownloadSpam>} + */ + _downloadSpamForUrl = new Map(); + + /** + * This set stores views that are waiting to have download notification + * listeners attached. They will be attached when the spamList is created + * (i.e. when the first spam download is blocked). + * @type {Set<Object>} + */ + _pendingViews = new Set(); + + /** + * Set to true when we first start _blocking downloads in the window. This is + * used to lazily load the spamList. Spam downloads are rare enough that many + * sessions will have no blocked downloads. So we don't want to create a + * DownloadList unless we actually need it. + * @type {Boolean} + */ + _blocking = false; + + /** + * A per-window DownloadList for blocked spam downloads. Registered views will + * be sent notifications about downloads in this list, so that blocked spam + * downloads can be represented in the UI. If spam downloads haven't been + * blocked in the window, this will be undefined. See DownloadList.sys.mjs. + * @type {DownloadList | undefined} + */ + get spamList() { + if (!this._blocking) { + return undefined; + } + if (!this._spamList) { + this._spamList = new lazy.DownloadList(); + } + return this._spamList; + } + + /** + * A per-window downloads indicator whose state depends on notifications from + * DownloadLists registered in the window (for example, the visual state of + * the downloads toolbar button). See DownloadsCommon.sys.mjs for more details. + * @type {DownloadsIndicatorData} + */ + get indicator() { + if (!this._indicator) { + this._indicator = lazy.DownloadsCommon.getIndicatorData(this._window); + } + return this._indicator; + } + + /** + * Add a blocked download to the spamList or increment the count of an + * existing blocked download, then notify listeners about this. + * @param {String} url + */ + addDownloadSpam(url) { + this._blocking = true; + // Start listening on registered downloads views, if any exist. + this._maybeAddViews(); + // If this URL is already paired with a DownloadSpam object, increment its + // blocked downloads count by 1 and don't open the downloads panel. + if (this._downloadSpamForUrl.has(url)) { + let downloadSpam = this._downloadSpamForUrl.get(url); + downloadSpam.blockedDownloadsCount += 1; + this.indicator.onDownloadStateChanged(downloadSpam); + return; + } + // Otherwise, create a new DownloadSpam object for the URL, add it to the + // spamList, and open the downloads panel. + let downloadSpam = new DownloadSpam(url); + this.spamList.add(downloadSpam); + this._downloadSpamForUrl.set(url, downloadSpam); + this._notifyDownloadSpamAdded(downloadSpam); + } + + /** + * Notify the downloads panel that a new download has been added to the + * spamList. This is invoked when a new DownloadSpam object is created. + * @param {DownloadSpam} downloadSpam + */ + _notifyDownloadSpamAdded(downloadSpam) { + let hasActiveDownloads = lazy.DownloadsCommon.summarizeDownloads( + this.indicator._activeDownloads() + ).numDownloading; + if ( + !hasActiveDownloads && + this._window === lazy.BrowserWindowTracker.getTopWindow() + ) { + // If there are no active downloads, open the downloads panel. + this._window.DownloadsPanel.showPanel(); + } else { + // Otherwise, flash a taskbar/dock icon notification if available. + this._window.getAttention(); + } + this.indicator.onDownloadAdded(downloadSpam); + } + + /** + * Remove the download spam data for a given source URL. + * @param {String} url + */ + removeDownloadSpamForUrl(url) { + if (this._downloadSpamForUrl.has(url)) { + let downloadSpam = this._downloadSpamForUrl.get(url); + this.spamList.remove(downloadSpam); + this.indicator.onDownloadRemoved(downloadSpam); + this._downloadSpamForUrl.delete(url); + } + } + + /** + * Set up a downloads view (e.g. the downloads panel) to receive notifications + * about downloads in the spamList. + * @param {Object} view An object that implements handlers for download + * related notifications, like onDownloadAdded. + */ + registerView(view) { + if (!view || this.spamList?._views.has(view)) { + return; + } + this._pendingViews.add(view); + this._maybeAddViews(); + } + + /** + * If any downloads have been blocked in the window, add download notification + * listeners for each downloads view that has been registered. + */ + _maybeAddViews() { + if (this.spamList) { + for (let view of this._pendingViews) { + if (!this.spamList._views.has(view)) { + this.spamList.addView(view); + } + } + this._pendingViews.clear(); + } + } + + /** + * Remove download notification listeners for all views. This is invoked when + * the window is closed. + */ + removeAllViews() { + if (this.spamList) { + for (let view of this.spamList._views) { + this.spamList.removeView(view); + } + } + this._pendingViews.clear(); + } +} + +/** + * Responsible for detecting events related to downloads spam and notifying the + * relevant window's WindowSpamProtection object. This is a singleton object, + * constructed by DownloadIntegration.sys.mjs when the first download is blocked. + */ +export class DownloadSpamProtection { + /** + * Stores spam protection data per-window. + * @type {WeakMap<Window, WindowSpamProtection>} + */ + _forWindowMap = new WeakMap(); + + /** + * Add download spam data for a given source URL in the window where the + * download was blocked. This is invoked when a download is blocked by + * nsExternalAppHandler::IsDownloadSpam + * @param {String} url + * @param {Window} window + */ + update(url, window) { + if (window == null) { + lazy.DownloadsCommon.log( + "Download spam blocked in a non-chrome window. URL: ", + url + ); + return; + } + // Get the spam protection object for a given window or create one if it + // does not already exist. Also attach notification listeners to any pending + // downloads views. + let wsp = + this._forWindowMap.get(window) ?? new WindowSpamProtection(window); + this._forWindowMap.set(window, wsp); + wsp.addDownloadSpam(url); + } + + /** + * Get the spam list for a given window (provided it exists). + * @param {Window} window + * @returns {DownloadList} + */ + getSpamListForWindow(window) { + return this._forWindowMap.get(window)?.spamList; + } + + /** + * Remove the download spam data for a given source URL in the passed window, + * if any exists. + * @param {String} url + * @param {Window} window + */ + removeDownloadSpamForWindow(url, window) { + let wsp = this._forWindowMap.get(window); + wsp?.removeDownloadSpamForUrl(url); + } + + /** + * Create the spam protection object for a given window (if not already + * created) and prepare to start listening for notifications on the passed + * downloads view. The bulk of resources won't be expended until a download is + * blocked. To add multiple views, call this method multiple times. + * @param {Object} view An object that implements handlers for download + * related notifications, like onDownloadAdded. + * @param {Window} window + */ + register(view, window) { + let wsp = + this._forWindowMap.get(window) ?? new WindowSpamProtection(window); + // Try setting up the view now; it will be deferred if there's no spam. + wsp.registerView(view); + this._forWindowMap.set(window, wsp); + } + + /** + * Remove the spam protection object for a window when it is closed. + * @param {Window} window + */ + unregister(window) { + let wsp = this._forWindowMap.get(window); + if (wsp) { + // Stop listening on the view if it was previously set up. + wsp.removeAllViews(); + this._forWindowMap.delete(window); + } + } +} + +/** + * Represents a special Download object for download spam. + * @extends Download + */ +class DownloadSpam extends Download { + constructor(url) { + super(); + this.hasBlockedData = true; + this.stopped = true; + this.error = new DownloadError({ + becauseBlockedByReputationCheck: true, + reputationCheckVerdict: lazy.Downloads.Error.BLOCK_VERDICT_DOWNLOAD_SPAM, + }); + this.target = { path: "" }; + this.source = { url }; + this.blockedDownloadsCount = 1; + } +} |