import * as electron from 'electron/main'; import { EventEmitter } from 'events'; import objectsRegistry from '@electron/internal/browser/remote/objects-registry'; import { ipcMainInternal } from '@electron/internal/browser/ipc-main-internal'; import { isPromise, isSerializableObject, deserialize, serialize } from '@electron/internal/common/type-utils'; import type { MetaTypeFromRenderer, ObjectMember, MetaType, ObjProtoDescriptor } from '@electron/internal/common/remote/types'; import { IPC_MESSAGES } from '@electron/internal/common/remote/ipc-messages'; const v8Util = process._linkedBinding('electron_common_v8_util'); const eventBinding = process._linkedBinding('electron_browser_event'); const features = process._linkedBinding('electron_common_features'); if (!features.isRemoteModuleEnabled()) { throw new Error('remote module is disabled'); } // The internal properties of Function. const FUNCTION_PROPERTIES = [ 'length', 'name', 'arguments', 'caller', 'prototype' ]; type RendererFunctionId = [string, number] // [contextId, funcId] type FinalizerInfo = { id: RendererFunctionId, webContents: electron.WebContents, frameId: number }; type CallIntoRenderer = (...args: any[]) => void // The remote functions in renderer processes. const rendererFunctionCache = new Map>(); // eslint-disable-next-line no-undef const finalizationRegistry = new FinalizationRegistry((fi: FinalizerInfo) => { const mapKey = fi.id[0] + '~' + fi.id[1]; const ref = rendererFunctionCache.get(mapKey); if (ref !== undefined && ref.deref() === undefined) { rendererFunctionCache.delete(mapKey); if (!fi.webContents.isDestroyed()) { fi.webContents.sendToFrame(fi.frameId, IPC_MESSAGES.RENDERER_RELEASE_CALLBACK, fi.id[0], fi.id[1]); } } }); function getCachedRendererFunction (id: RendererFunctionId): CallIntoRenderer | undefined { const mapKey = id[0] + '~' + id[1]; const ref = rendererFunctionCache.get(mapKey); if (ref !== undefined) { const deref = ref.deref(); if (deref !== undefined) return deref; } } function setCachedRendererFunction (id: RendererFunctionId, wc: electron.WebContents, frameId: number, value: CallIntoRenderer) { // eslint-disable-next-line no-undef const wr = new WeakRef(value); const mapKey = id[0] + '~' + id[1]; rendererFunctionCache.set(mapKey, wr); finalizationRegistry.register(value, { id, webContents: wc, frameId } as FinalizerInfo); return value; } // Return the description of object's members: const getObjectMembers = function (object: any): ObjectMember[] { let names = Object.getOwnPropertyNames(object); // For Function, we should not override following properties even though they // are "own" properties. if (typeof object === 'function') { names = names.filter((name) => { return !FUNCTION_PROPERTIES.includes(name); }); } // Map properties to descriptors. return names.map((name) => { const descriptor = Object.getOwnPropertyDescriptor(object, name)!; let type: ObjectMember['type']; let writable = false; if (descriptor.get === undefined && typeof object[name] === 'function') { type = 'method'; } else { if (descriptor.set || descriptor.writable) writable = true; type = 'get'; } return { name, enumerable: descriptor.enumerable, writable, type }; }); }; // Return the description of object's prototype. const getObjectPrototype = function (object: any): ObjProtoDescriptor { const proto = Object.getPrototypeOf(object); if (proto === null || proto === Object.prototype) return null; return { members: getObjectMembers(proto), proto: getObjectPrototype(proto) }; }; // Convert a real value into meta data. const valueToMeta = function (sender: electron.WebContents, contextId: string, value: any, optimizeSimpleObject = false): MetaType { // Determine the type of value. let type: MetaType['type']; switch (typeof value) { case 'object': // Recognize certain types of objects. if (value instanceof Buffer) { type = 'buffer'; } else if (value && value.constructor && value.constructor.name === 'NativeImage') { type = 'nativeimage'; } else if (Array.isArray(value)) { type = 'array'; } else if (value instanceof Error) { type = 'error'; } else if (isSerializableObject(value)) { type = 'value'; } else if (isPromise(value)) { type = 'promise'; } else if (Object.prototype.hasOwnProperty.call(value, 'callee') && value.length != null) { // Treat the arguments object as array. type = 'array'; } else if (optimizeSimpleObject && v8Util.getHiddenValue(value, 'simple')) { // Treat simple objects as value. type = 'value'; } else { type = 'object'; } break; case 'function': type = 'function'; break; default: type = 'value'; break; } // Fill the meta object according to value's type. if (type === 'array') { return { type, members: value.map((el: any) => valueToMeta(sender, contextId, el, optimizeSimpleObject)) }; } else if (type === 'nativeimage') { return { type, value: serialize(value) }; } else if (type === 'object' || type === 'function') { return { type, name: value.constructor ? value.constructor.name : '', // Reference the original value if it's an object, because when it's // passed to renderer we would assume the renderer keeps a reference of // it. id: objectsRegistry.add(sender, contextId, value), members: getObjectMembers(value), proto: getObjectPrototype(value) }; } else if (type === 'buffer') { return { type, value }; } else if (type === 'promise') { // Add default handler to prevent unhandled rejections in main process // Instead they should appear in the renderer process value.then(function () {}, function () {}); return { type, then: valueToMeta(sender, contextId, function (onFulfilled: Function, onRejected: Function) { value.then(onFulfilled, onRejected); }) }; } else if (type === 'error') { return { type, value, members: Object.keys(value).map(name => ({ name, value: valueToMeta(sender, contextId, value[name]) })) }; } else { return { type: 'value', value }; } }; const throwRPCError = function (message: string) { const error = new Error(message) as Error & {code: string, errno: number}; error.code = 'EBADRPC'; error.errno = -72; throw error; }; const removeRemoteListenersAndLogWarning = (sender: any, callIntoRenderer: (...args: any[]) => void) => { const location = v8Util.getHiddenValue(callIntoRenderer, 'location'); let message = 'Attempting to call a function in a renderer window that has been closed or released.' + `\nFunction provided here: ${location}`; if (sender instanceof EventEmitter) { const remoteEvents = sender.eventNames().filter((eventName) => { return sender.listeners(eventName).includes(callIntoRenderer); }); if (remoteEvents.length > 0) { message += `\nRemote event names: ${remoteEvents.join(', ')}`; remoteEvents.forEach((eventName) => { sender.removeListener(eventName as any, callIntoRenderer); }); } } console.warn(message); }; const fakeConstructor = (constructor: Function, name: string) => new Proxy(Object, { get (target, prop, receiver) { if (prop === 'name') { return name; } else { return Reflect.get(target, prop, receiver); } } }); // Convert array of meta data from renderer into array of real values. const unwrapArgs = function (sender: electron.WebContents, frameId: number, contextId: string, args: any[]) { const metaToValue = function (meta: MetaTypeFromRenderer): any { switch (meta.type) { case 'nativeimage': return deserialize(meta.value); case 'value': return meta.value; case 'remote-object': return objectsRegistry.get(meta.id); case 'array': return unwrapArgs(sender, frameId, contextId, meta.value); case 'buffer': return Buffer.from(meta.value.buffer, meta.value.byteOffset, meta.value.byteLength); case 'promise': return Promise.resolve({ then: metaToValue(meta.then) }); case 'object': { const ret: any = meta.name !== 'Object' ? Object.create({ constructor: fakeConstructor(Object, meta.name) }) : {}; for (const { name, value } of meta.members) { ret[name] = metaToValue(value); } return ret; } case 'function-with-return-value': { const returnValue = metaToValue(meta.value); return function () { return returnValue; }; } case 'function': { // Merge contextId and meta.id, since meta.id can be the same in // different webContents. const objectId: [string, number] = [contextId, meta.id]; // Cache the callbacks in renderer. const cachedFunction = getCachedRendererFunction(objectId); if (cachedFunction !== undefined) { return cachedFunction; } const callIntoRenderer = function (this: any, ...args: any[]) { let succeed = false; if (!sender.isDestroyed()) { succeed = sender._sendToFrameInternal(frameId, IPC_MESSAGES.RENDERER_CALLBACK, contextId, meta.id, valueToMeta(sender, contextId, args)); } if (!succeed) { removeRemoteListenersAndLogWarning(this, callIntoRenderer); } }; v8Util.setHiddenValue(callIntoRenderer, 'location', meta.location); Object.defineProperty(callIntoRenderer, 'length', { value: meta.length }); setCachedRendererFunction(objectId, sender, frameId, callIntoRenderer); return callIntoRenderer; } default: throw new TypeError(`Unknown type: ${(meta as any).type}`); } }; return args.map(metaToValue); }; const isRemoteModuleEnabledImpl = function (contents: electron.WebContents) { const webPreferences = contents.getLastWebPreferences() || {}; return webPreferences.enableRemoteModule != null ? !!webPreferences.enableRemoteModule : false; }; const isRemoteModuleEnabledCache = new WeakMap(); export const isRemoteModuleEnabled = function (contents: electron.WebContents) { if (!isRemoteModuleEnabledCache.has(contents)) { isRemoteModuleEnabledCache.set(contents, isRemoteModuleEnabledImpl(contents)); } return isRemoteModuleEnabledCache.get(contents); }; const handleRemoteCommand = function (channel: string, handler: (event: ElectronInternal.IpcMainInternalEvent, contextId: string, ...args: any[]) => void) { ipcMainInternal.on(channel, (event, contextId: string, ...args: any[]) => { let returnValue; if (!isRemoteModuleEnabled(event.sender)) { event.returnValue = null; return; } try { returnValue = handler(event, contextId, ...args); } catch (error) { returnValue = { type: 'exception', value: valueToMeta(event.sender, contextId, error) }; } if (returnValue !== undefined) { event.returnValue = returnValue; } }); }; const emitCustomEvent = function (contents: electron.WebContents, eventName: string, ...args: any[]) { const event = eventBinding.createWithSender(contents); electron.app.emit(eventName, event, contents, ...args); contents.emit(eventName, event, ...args); return event; }; const logStack = function (contents: electron.WebContents, code: string, stack: string | undefined) { if (stack) { console.warn(`WebContents (${contents.id}): ${code}`, stack); } }; handleRemoteCommand(IPC_MESSAGES.BROWSER_WRONG_CONTEXT_ERROR, function (event, contextId, passedContextId, id) { const objectId: [string, number] = [passedContextId, id]; const cachedFunction = getCachedRendererFunction(objectId); if (cachedFunction === undefined) { // Do nothing if the error has already been reported before. return; } removeRemoteListenersAndLogWarning(event.sender, cachedFunction); }); handleRemoteCommand(IPC_MESSAGES.BROWSER_REQUIRE, function (event, contextId, moduleName, stack) { logStack(event.sender, `remote.require('${moduleName}')`, stack); const customEvent = emitCustomEvent(event.sender, 'remote-require', moduleName); if (customEvent.returnValue === undefined) { if (customEvent.defaultPrevented) { throw new Error(`Blocked remote.require('${moduleName}')`); } else { customEvent.returnValue = (process as any).mainModule.require(moduleName); } } return valueToMeta(event.sender, contextId, customEvent.returnValue); }); handleRemoteCommand(IPC_MESSAGES.BROWSER_GET_BUILTIN, function (event, contextId, moduleName, stack) { logStack(event.sender, `remote.getBuiltin('${moduleName}')`, stack); const customEvent = emitCustomEvent(event.sender, 'remote-get-builtin', moduleName); if (customEvent.returnValue === undefined) { if (customEvent.defaultPrevented) { throw new Error(`Blocked remote.getBuiltin('${moduleName}')`); } else { customEvent.returnValue = (electron as any)[moduleName]; } } return valueToMeta(event.sender, contextId, customEvent.returnValue); }); handleRemoteCommand(IPC_MESSAGES.BROWSER_GET_GLOBAL, function (event, contextId, globalName, stack) { logStack(event.sender, `remote.getGlobal('${globalName}')`, stack); const customEvent = emitCustomEvent(event.sender, 'remote-get-global', globalName); if (customEvent.returnValue === undefined) { if (customEvent.defaultPrevented) { throw new Error(`Blocked remote.getGlobal('${globalName}')`); } else { customEvent.returnValue = (global as any)[globalName]; } } return valueToMeta(event.sender, contextId, customEvent.returnValue); }); handleRemoteCommand(IPC_MESSAGES.BROWSER_GET_CURRENT_WINDOW, function (event, contextId, stack) { logStack(event.sender, 'remote.getCurrentWindow()', stack); const customEvent = emitCustomEvent(event.sender, 'remote-get-current-window'); if (customEvent.returnValue === undefined) { if (customEvent.defaultPrevented) { throw new Error('Blocked remote.getCurrentWindow()'); } else { customEvent.returnValue = event.sender.getOwnerBrowserWindow(); } } return valueToMeta(event.sender, contextId, customEvent.returnValue); }); handleRemoteCommand(IPC_MESSAGES.BROWSER_GET_CURRENT_WEB_CONTENTS, function (event, contextId, stack) { logStack(event.sender, 'remote.getCurrentWebContents()', stack); const customEvent = emitCustomEvent(event.sender, 'remote-get-current-web-contents'); if (customEvent.returnValue === undefined) { if (customEvent.defaultPrevented) { throw new Error('Blocked remote.getCurrentWebContents()'); } else { customEvent.returnValue = event.sender; } } return valueToMeta(event.sender, contextId, customEvent.returnValue); }); handleRemoteCommand(IPC_MESSAGES.BROWSER_CONSTRUCTOR, function (event, contextId, id, args) { args = unwrapArgs(event.sender, event.frameId, contextId, args); const constructor = objectsRegistry.get(id); if (constructor == null) { throwRPCError(`Cannot call constructor on missing remote object ${id}`); } return valueToMeta(event.sender, contextId, new constructor(...args)); }); handleRemoteCommand(IPC_MESSAGES.BROWSER_FUNCTION_CALL, function (event, contextId, id, args) { args = unwrapArgs(event.sender, event.frameId, contextId, args); const func = objectsRegistry.get(id); if (func == null) { throwRPCError(`Cannot call function on missing remote object ${id}`); } try { return valueToMeta(event.sender, contextId, func(...args), true); } catch (error) { const err = new Error(`Could not call remote function '${func.name || 'anonymous'}'. Check that the function signature is correct. Underlying error: ${error.message}\nUnderlying stack: ${error.stack}\n`); (err as any).cause = error; throw err; } }); handleRemoteCommand(IPC_MESSAGES.BROWSER_MEMBER_CONSTRUCTOR, function (event, contextId, id, method, args) { args = unwrapArgs(event.sender, event.frameId, contextId, args); const object = objectsRegistry.get(id); if (object == null) { throwRPCError(`Cannot call constructor '${method}' on missing remote object ${id}`); } return valueToMeta(event.sender, contextId, new object[method](...args)); }); handleRemoteCommand(IPC_MESSAGES.BROWSER_MEMBER_CALL, function (event, contextId, id, method, args) { args = unwrapArgs(event.sender, event.frameId, contextId, args); const object = objectsRegistry.get(id); if (object == null) { throwRPCError(`Cannot call method '${method}' on missing remote object ${id}`); } try { return valueToMeta(event.sender, contextId, object[method](...args), true); } catch (error) { const err = new Error(`Could not call remote method '${method}'. Check that the method signature is correct. Underlying error: ${error.message}\nUnderlying stack: ${error.stack}\n`); (err as any).cause = error; throw err; } }); handleRemoteCommand(IPC_MESSAGES.BROWSER_MEMBER_SET, function (event, contextId, id, name, args) { args = unwrapArgs(event.sender, event.frameId, contextId, args); const obj = objectsRegistry.get(id); if (obj == null) { throwRPCError(`Cannot set property '${name}' on missing remote object ${id}`); } obj[name] = args[0]; return null; }); handleRemoteCommand(IPC_MESSAGES.BROWSER_MEMBER_GET, function (event, contextId, id, name) { const obj = objectsRegistry.get(id); if (obj == null) { throwRPCError(`Cannot get property '${name}' on missing remote object ${id}`); } return valueToMeta(event.sender, contextId, obj[name]); }); handleRemoteCommand(IPC_MESSAGES.BROWSER_DEREFERENCE, function (event, contextId, id) { objectsRegistry.remove(event.sender, contextId, id); }); handleRemoteCommand(IPC_MESSAGES.BROWSER_CONTEXT_RELEASE, (event, contextId) => { objectsRegistry.clear(event.sender, contextId); });