/* * Copyright (C) 2021 Yomichan Authors * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <https://www.gnu.org/licenses/>. */ /** * This class is used to return the ancestor frame IDs for the current frame. * This is a workaround to using the `webNavigation.getAllFrames` API, which * would require an additional permission that is otherwise unnecessary. * It is also used to track the correlation between child frame elements and their IDs. */ class FrameAncestryHandler { /** * Creates a new instance. * @param frameId The frame ID of the current frame the instance is instantiated in. */ constructor(frameId) { this._frameId = frameId; this._isPrepared = false; this._requestMessageId = 'FrameAncestryHandler.requestFrameInfo'; this._responseMessageIdBase = `${this._requestMessageId}.response.`; this._getFrameAncestryInfoPromise = null; this._childFrameMap = new Map(); } /** * Gets the frame ID that the instance is instantiated in. */ get frameId() { return this._frameId; } /** * Initializes event event listening. */ prepare() { if (this._isPrepared) { return; } window.addEventListener('message', this._onWindowMessage.bind(this), false); this._isPrepared = true; } /** * Returns whether or not this frame is the root frame in the tab. * @returns `true` if it is the root, otherwise `false`. */ isRootFrame() { return (window === window.parent); } /** * Gets the frame ancestry information for the current frame. If the frame is the * root frame, an empty array is returned. Otherwise, an array of frame IDs is returned, * starting from the nearest ancestor. * @param timeout The maximum time to wait to receive a response to frame information requests. * @returns An array of frame IDs corresponding to the ancestors of the current frame. */ async getFrameAncestryInfo() { if (this._getFrameAncestryInfoPromise === null) { this._getFrameAncestryInfoPromise = this._getFrameAncestryInfo(5000); } return await this._getFrameAncestryInfoPromise; } /** * Gets the frame element of a child frame given a frame ID. * For this function to work, the `getFrameAncestryInfo` function needs to have * been invoked previously. * @param frameId The frame ID of the child frame to get. * @returns The element corresponding to the frame with ID `frameId`, otherwise `null`. */ getChildFrameElement(frameId) { const frameInfo = this._childFrameMap.get(frameId); if (typeof frameInfo === 'undefined') { return null; } let {frameElement} = frameInfo; if (typeof frameElement === 'undefined') { frameElement = this._findFrameElementWithContentWindow(frameInfo.window); frameInfo.frameElement = frameElement; } return frameElement; } // Private _getFrameAncestryInfo(timeout=5000) { return new Promise((resolve, reject) => { const targetWindow = window.parent; if (window === targetWindow) { resolve([]); return; } const uniqueId = generateId(16); let nonce = generateId(16); const responseMessageId = `${this._responseMessageIdBase}${uniqueId}`; const results = []; let timer = null; const cleanup = () => { if (timer !== null) { clearTimeout(timer); timer = null; } yomichan.crossFrame.unregisterHandler(responseMessageId); }; const onMessage = (params) => { if (params.nonce !== nonce) { return null; } // Add result const {frameId, more} = params; results.push(frameId); nonce = generateId(16); if (!more) { // Cleanup cleanup(); // Finish resolve(results); } return {nonce}; }; const onTimeout = () => { timer = null; cleanup(); reject(new Error(`Request for parent frame ID timed out after ${timeout}ms`)); }; const resetTimeout = () => { if (timer !== null) { clearTimeout(timer); } timer = setTimeout(onTimeout, timeout); }; // Start yomichan.crossFrame.registerHandlers([[responseMessageId, {async: false, handler: onMessage}]]); resetTimeout(); const frameId = this._frameId; this._requestFrameInfo(targetWindow, frameId, frameId, uniqueId, nonce); }); } _onWindowMessage(event) { const {source} = event; if (source === window || source.parent !== window) { return; } const {data} = event; if ( typeof data === 'object' && data !== null && data.action === this._requestMessageId ) { this._onRequestFrameInfo(data.params, source); } } async _onRequestFrameInfo(params, source) { try { let {originFrameId, childFrameId, uniqueId, nonce} = params; if ( !this._isNonNegativeInteger(originFrameId) || typeof uniqueId !== 'string' || typeof nonce !== 'string' ) { return; } const frameId = this._frameId; const {parent} = window; const more = (window !== parent); const responseParams = {frameId, nonce, more}; const responseMessageId = `${this._responseMessageIdBase}${uniqueId}`; try { const response = await yomichan.crossFrame.invoke(originFrameId, responseMessageId, responseParams); if (response === null) { return; } nonce = response.nonce; } catch (e) { return; } if (!this._childFrameMap.has(childFrameId)) { this._childFrameMap.set(childFrameId, {window: source, frameElement: void 0}); } if (more) { this._requestFrameInfo(parent, originFrameId, frameId, uniqueId, nonce); } } catch (e) { // NOP } } _requestFrameInfo(targetWindow, originFrameId, childFrameId, uniqueId, nonce) { targetWindow.postMessage({ action: this._requestMessageId, params: {originFrameId, childFrameId, uniqueId, nonce} }, '*'); } _isNonNegativeInteger(value) { return ( typeof value === 'number' && Number.isFinite(value) && value >= 0 && Math.floor(value) === value ); } _findFrameElementWithContentWindow(contentWindow) { // Check frameElement, for non-null same-origin frames try { const {frameElement} = contentWindow; if (frameElement !== null) { return frameElement; } } catch (e) { // NOP } // Check frames const frameTypes = ['iframe', 'frame', 'embed']; for (const frameType of frameTypes) { for (const frame of document.getElementsByTagName(frameType)) { if (frame.contentWindow === contentWindow) { return frame; } } } // Check for shadow roots const rootElements = [document.documentElement]; while (rootElements.length > 0) { const rootElement = rootElements.shift(); const walker = document.createTreeWalker(rootElement, NodeFilter.SHOW_ELEMENT); while (walker.nextNode()) { const element = walker.currentNode; if (element.contentWindow === contentWindow) { return element; } const shadowRoot = ( element.shadowRoot || element.openOrClosedShadowRoot // Available to Firefox 63+ for WebExtensions ); if (shadowRoot) { rootElements.push(shadowRoot); } } } // Not found return null; } }