electron/lib/common/asar.js
Alexey Kuzmin 382afc03ae chore: clean up asar stuff (#14505)
* chore: reformat code

* refactor: getOrCreateArchive() for ASARs

 - store cached archive in a Map
 - return `null` instead of `false` on failures

* refactor: splitPath() for ASARs

 - store custom extension in a constant
 - remove magic numbers
 - add comments

* refactor: explicitly use assert() for a developer error

* chore: remove console.log() calls

* refactor: replace "p" arguments with "pathArgument"

"path" would be a better name, but it is already taken
but the "path" Node module.

* refactor: createError() for ASARs

 - return an `Error` instance
 - use enum for error types
 - minor improvements

* refactor: use more meaningful name for an arg than just "arg"
2018-09-10 08:29:19 -07:00

756 lines
23 KiB
JavaScript

(function () {
const asar = process.binding('atom_common_asar')
const assert = require('assert')
const {Buffer} = require('buffer')
const childProcess = require('child_process')
const path = require('path')
const util = require('util')
const envNoAsar = process.env.ELECTRON_NO_ASAR &&
process.type !== 'browser' &&
process.type !== 'renderer'
const isAsarDisabled = () => process.noAsar || envNoAsar
/**
* @param {!Function} functionToCall
* @param {!Array|undefined} args
*/
const nextTick = (functionToCall, args = []) => {
process.nextTick(() => functionToCall(...args))
}
// Cache asar archive objects.
const cachedArchives = new Map()
const getOrCreateArchive = archivePath => {
const isCached = cachedArchives.has(archivePath)
if (isCached) {
return cachedArchives.get(archivePath)
}
const newArchive = asar.createArchive(archivePath)
if (!newArchive) return null
cachedArchives.set(archivePath, newArchive)
return newArchive
}
// Clean cache on quit.
process.on('exit', () => {
for (const archive of cachedArchives.values()) {
archive.destroy()
}
cachedArchives.clear()
})
const ASAR_EXTENSION = '.asar'
// Separate asar package's path from full path.
const splitPath = archivePathOrBuffer => {
// Shortcut for disabled asar.
if (isAsarDisabled()) return {isAsar: false}
// Check for a bad argument type.
let archivePath = archivePathOrBuffer
if (Buffer.isBuffer(archivePathOrBuffer)) {
archivePath = archivePathOrBuffer.toString()
}
if (typeof archivePath !== 'string') return {isAsar: false}
if (archivePath.endsWith(ASAR_EXTENSION)) {
return {isAsar: true, asarPath: archivePath, filePath: ''}
}
archivePath = path.normalize(archivePath)
const index = archivePath.lastIndexOf(`${ASAR_EXTENSION}${path.sep}`)
if (index === -1) return {isAsar: false}
// E.g. for "//some/path/to/archive.asar/then/internal.file"...
return {
isAsar: true,
// "//some/path/to/archive.asar"
asarPath: archivePath.substr(0, index + ASAR_EXTENSION.length),
// "then/internal.file" (with a path separator excluded)
filePath: archivePath.substr(index + ASAR_EXTENSION.length + 1)
}
}
// Convert asar archive's Stats object to fs's Stats object.
let nextInode = 0
const uid = process.getuid != null ? process.getuid() : 0
const gid = process.getgid != null ? process.getgid() : 0
const fakeTime = new Date()
const msec = (date) => (date || fakeTime).getTime()
const asarStatsToFsStats = function (stats) {
const {Stats, constants} = require('fs')
let mode = constants.S_IROTH ^ constants.S_IRGRP ^ constants.S_IRUSR ^ constants.S_IWUSR
if (stats.isFile) {
mode ^= constants.S_IFREG
} else if (stats.isDirectory) {
mode ^= constants.S_IFDIR
} else if (stats.isLink) {
mode ^= constants.S_IFLNK
}
return new Stats(
1, // dev
mode, // mode
1, // nlink
uid,
gid,
0, // rdev
undefined, // blksize
++nextInode, // ino
stats.size,
undefined, // blocks,
msec(stats.atime), // atim_msec
msec(stats.mtime), // mtim_msec
msec(stats.ctime), // ctim_msec
msec(stats.birthtime) // birthtim_msec
)
}
const AsarError = {
NOT_FOUND: 'NOT_FOUND',
NOT_DIR: 'NOT_DIR',
NO_ACCESS: 'NO_ACCESS',
INVALID_ARCHIVE: 'INVALID_ARCHIVE'
}
const createError = (errorType, {asarPath, filePath} = {}) => {
let error
switch (errorType) {
case AsarError.NOT_FOUND:
error = new Error(`ENOENT, ${filePath} not found in ${asarPath}`)
error.code = 'ENOENT'
error.errno = -2
break
case AsarError.NOT_DIR:
error = new Error('ENOTDIR, not a directory')
error.code = 'ENOTDIR'
error.errno = -20
break
case AsarError.NO_ACCESS:
error = new Error(`EACCES: permission denied, access '${filePath}'`)
error.code = 'EACCES'
error.errno = -13
break
case AsarError.INVALID_ARCHIVE:
error = new Error(`Invalid package ${asarPath}`)
break
default:
assert.fail(`Invalid error type "${errorType}" passed to createError.`)
}
return error
}
const overrideAPISync = function (module, name, pathArgumentIndex) {
if (pathArgumentIndex == null) pathArgumentIndex = 0
const old = module[name]
module[name] = function () {
const pathArgument = arguments[pathArgumentIndex]
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return old.apply(this, arguments)
const archive = getOrCreateArchive(asarPath)
if (!archive) throw createError(AsarError.INVALID_ARCHIVE, {asarPath})
const newPath = archive.copyFileOut(filePath)
if (!newPath) throw createError(AsarError.NOT_FOUND, {asarPath, filePath})
arguments[pathArgumentIndex] = newPath
return old.apply(this, arguments)
}
}
const overrideAPI = function (module, name, pathArgumentIndex) {
if (pathArgumentIndex == null) pathArgumentIndex = 0
const old = module[name]
module[name] = function () {
const pathArgument = arguments[pathArgumentIndex]
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return old.apply(this, arguments)
const callback = arguments[arguments.length - 1]
if (typeof callback !== 'function') {
return overrideAPISync(module, name, pathArgumentIndex)
}
const archive = getOrCreateArchive(asarPath)
if (!archive) {
const error = createError(AsarError.INVALID_ARCHIVE, {asarPath})
nextTick(callback, [error])
return
}
const newPath = archive.copyFileOut(filePath)
if (!newPath) {
const error = createError(AsarError.NOT_FOUND, {asarPath, filePath})
nextTick(callback, [error])
return
}
arguments[pathArgumentIndex] = newPath
return old.apply(this, arguments)
}
if (old[util.promisify.custom]) {
module[name][util.promisify.custom] = function () {
const pathArgument = arguments[pathArgumentIndex]
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return old[util.promisify.custom].apply(this, arguments)
const archive = getOrCreateArchive(asarPath)
if (!archive) {
return Promise.reject(createError(AsarError.INVALID_ARCHIVE, {asarPath}))
}
const newPath = archive.copyFileOut(filePath)
if (!newPath) {
return Promise.reject(createError(AsarError.NOT_FOUND, {asarPath, filePath}))
}
arguments[pathArgumentIndex] = newPath
return old[util.promisify.custom].apply(this, arguments)
}
}
}
// Override fs APIs.
exports.wrapFsWithAsar = fs => {
const logFDs = {}
const logASARAccess = (asarPath, filePath, offset) => {
if (!process.env.ELECTRON_LOG_ASAR_READS) return
if (!logFDs[asarPath]) {
const path = require('path')
const logFilename = `${path.basename(asarPath, '.asar')}-access-log.txt`
const logPath = path.join(require('os').tmpdir(), logFilename)
logFDs[asarPath] = fs.openSync(logPath, 'a')
}
fs.writeSync(logFDs[asarPath], `${offset}: ${filePath}\n`)
}
const {lstatSync} = fs
fs.lstatSync = pathArgument => {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return lstatSync(pathArgument)
const archive = getOrCreateArchive(asarPath)
if (!archive) throw createError(AsarError.INVALID_ARCHIVE, {asarPath})
const stats = archive.stat(filePath)
if (!stats) throw createError(AsarError.NOT_FOUND, {asarPath, filePath})
return asarStatsToFsStats(stats)
}
const {lstat} = fs
fs.lstat = (pathArgument, callback) => {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return lstat(pathArgument, callback)
const archive = getOrCreateArchive(asarPath)
if (!archive) {
const error = createError(AsarError.INVALID_ARCHIVE, {asarPath})
nextTick(callback, [error])
return
}
const stats = archive.stat(filePath)
if (!stats) {
const error = createError(AsarError.NOT_FOUND, {asarPath, filePath})
nextTick(callback, [error])
return
}
const fsStats = asarStatsToFsStats(stats)
nextTick(callback, [null, fsStats])
}
const {statSync} = fs
fs.statSync = pathArgument => {
const {isAsar} = splitPath(pathArgument)
if (!isAsar) return statSync(pathArgument)
// Do not distinguish links for now.
return fs.lstatSync(pathArgument)
}
const {stat} = fs
fs.stat = (pathArgument, callback) => {
const {isAsar} = splitPath(pathArgument)
if (!isAsar) return stat(pathArgument, callback)
// Do not distinguish links for now.
process.nextTick(() => fs.lstat(pathArgument, callback))
}
const {statSyncNoException} = fs
fs.statSyncNoException = pathArgument => {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return statSyncNoException(pathArgument)
const archive = getOrCreateArchive(asarPath)
if (!archive) return false
const stats = archive.stat(filePath)
if (!stats) return false
return asarStatsToFsStats(stats)
}
const {realpathSync} = fs
fs.realpathSync = function (pathArgument) {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return realpathSync.apply(this, arguments)
const archive = getOrCreateArchive(asarPath)
if (!archive) {
throw createError(AsarError.INVALID_ARCHIVE, {asarPath})
}
const fileRealPath = archive.realpath(filePath)
if (fileRealPath === false) {
throw createError(AsarError.NOT_FOUND, {asarPath, filePath})
}
return path.join(realpathSync(asarPath), fileRealPath)
}
fs.realpathSync.native = function (pathArgument) {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return realpathSync.native.apply(this, arguments)
const archive = getOrCreateArchive(asarPath)
if (!archive) {
throw createError(AsarError.INVALID_ARCHIVE, {asarPath})
}
const fileRealPath = archive.realpath(filePath)
if (fileRealPath === false) {
throw createError(AsarError.NOT_FOUND, {asarPath, filePath})
}
return path.join(realpathSync.native(asarPath), fileRealPath)
}
const {realpath} = fs
fs.realpath = function (pathArgument, cache, callback) {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return realpath.apply(this, arguments)
if (typeof cache === 'function') {
callback = cache
cache = undefined
}
const archive = getOrCreateArchive(asarPath)
if (!archive) {
const error = createError(AsarError.INVALID_ARCHIVE, {asarPath})
nextTick(callback, [error])
return
}
const fileRealPath = archive.realpath(filePath)
if (fileRealPath === false) {
const error = createError(AsarError.NOT_FOUND, {asarPath, filePath})
nextTick(callback, [error])
return
}
realpath(asarPath, (error, archiveRealPath) => {
if (error === null) {
const fullPath = path.join(archiveRealPath, fileRealPath)
callback(null, fullPath)
} else {
callback(error)
}
})
}
fs.realpath.native = function (pathArgument, cache, callback) {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return realpath.native.apply(this, arguments)
if (typeof cache === 'function') {
callback = cache
cache = undefined
}
const archive = getOrCreateArchive(asarPath)
if (!archive) {
const error = createError(AsarError.INVALID_ARCHIVE, {asarPath})
nextTick(callback, [error])
return
}
const fileRealPath = archive.realpath(filePath)
if (fileRealPath === false) {
const error = createError(AsarError.NOT_FOUND, {asarPath, filePath})
nextTick(callback, [error])
return
}
realpath.native(asarPath, (error, archiveRealPath) => {
if (error === null) {
const fullPath = path.join(archiveRealPath, fileRealPath)
callback(null, fullPath)
} else {
callback(error)
}
})
}
const {exists} = fs
fs.exists = (pathArgument, callback) => {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return exists(pathArgument, callback)
const archive = getOrCreateArchive(asarPath)
if (!archive) {
const error = createError(AsarError.INVALID_ARCHIVE, {asarPath})
nextTick(callback, [error])
return
}
const pathExists = (archive.stat(filePath) !== false)
nextTick(callback, [pathExists])
}
fs.exists[util.promisify.custom] = pathArgument => {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return exists[util.promisify.custom](pathArgument)
const archive = getOrCreateArchive(asarPath)
if (!archive) {
const error = createError(AsarError.INVALID_ARCHIVE, {asarPath})
return Promise.reject(error)
}
return Promise.resolve(archive.stat(filePath) !== false)
}
const {existsSync} = fs
fs.existsSync = pathArgument => {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return existsSync(pathArgument)
const archive = getOrCreateArchive(asarPath)
if (!archive) return false
return archive.stat(filePath) !== false
}
const {access} = fs
fs.access = function (pathArgument, mode, callback) {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return access.apply(this, arguments)
if (typeof mode === 'function') {
callback = mode
mode = fs.constants.F_OK
}
const archive = getOrCreateArchive(asarPath)
if (!archive) {
const error = createError(AsarError.INVALID_ARCHIVE, {asarPath})
nextTick(callback, [error])
return
}
const info = archive.getFileInfo(filePath)
if (!info) {
const error = createError(AsarError.NOT_FOUND, {asarPath, filePath})
nextTick(callback, [error])
return
}
if (info.unpacked) {
const realPath = archive.copyFileOut(filePath)
return fs.access(realPath, mode, callback)
}
const stats = archive.stat(filePath)
if (!stats) {
const error = createError(AsarError.NOT_FOUND, {asarPath, filePath})
nextTick(callback, [error])
return
}
if (mode & fs.constants.W_OK) {
const error = createError(AsarError.NO_ACCESS, {asarPath, filePath})
nextTick(callback, [error])
return
}
nextTick(callback)
}
const {accessSync} = fs
fs.accessSync = function (pathArgument, mode) {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return accessSync.apply(this, arguments)
if (mode == null) mode = fs.constants.F_OK
const archive = getOrCreateArchive(asarPath)
if (!archive) {
throw createError(AsarError.INVALID_ARCHIVE, {asarPath})
}
const info = archive.getFileInfo(filePath)
if (!info) {
throw createError(AsarError.NOT_FOUND, {asarPath, filePath})
}
if (info.unpacked) {
const realPath = archive.copyFileOut(filePath)
return fs.accessSync(realPath, mode)
}
const stats = archive.stat(filePath)
if (!stats) {
throw createError(AsarError.NOT_FOUND, {asarPath, filePath})
}
if (mode & fs.constants.W_OK) {
throw createError(AsarError.NO_ACCESS, {asarPath, filePath})
}
}
const {readFile} = fs
fs.readFile = function (pathArgument, options, callback) {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return readFile.apply(this, arguments)
if (typeof options === 'function') {
callback = options
options = { encoding: null }
} else if (typeof options === 'string') {
options = { encoding: options }
} else if (options === null || options === undefined) {
options = { encoding: null }
} else if (typeof options !== 'object') {
throw new TypeError('Bad arguments')
}
const {encoding} = options
const archive = getOrCreateArchive(asarPath)
if (!archive) {
const error = createError(AsarError.INVALID_ARCHIVE, {asarPath})
nextTick(callback, [error])
return
}
const info = archive.getFileInfo(filePath)
if (!info) {
const error = createError(AsarError.NOT_FOUND, {asarPath, filePath})
nextTick(callback, [error])
return
}
if (info.size === 0) {
nextTick(callback, [null, encoding ? '' : Buffer.alloc(0)])
return
}
if (info.unpacked) {
const realPath = archive.copyFileOut(filePath)
return fs.readFile(realPath, options, callback)
}
const buffer = Buffer.alloc(info.size)
const fd = archive.getFd()
if (!(fd >= 0)) {
const error = createError(AsarError.NOT_FOUND, {asarPath, filePath})
nextTick(callback, [error])
return
}
logASARAccess(asarPath, filePath, info.offset)
fs.read(fd, buffer, 0, info.size, info.offset, error => {
callback(error, encoding ? buffer.toString(encoding) : buffer)
})
}
const {readFileSync} = fs
fs.readFileSync = function (pathArgument, options) {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return readFileSync.apply(this, arguments)
const archive = getOrCreateArchive(asarPath)
if (!archive) throw createError(AsarError.INVALID_ARCHIVE, {asarPath})
const info = archive.getFileInfo(filePath)
if (!info) throw createError(AsarError.NOT_FOUND, {asarPath, filePath})
if (info.size === 0) return (options) ? '' : Buffer.alloc(0)
if (info.unpacked) {
const realPath = archive.copyFileOut(filePath)
return fs.readFileSync(realPath, options)
}
if (!options) {
options = { encoding: null }
} else if (typeof options === 'string') {
options = { encoding: options }
} else if (typeof options !== 'object') {
throw new TypeError('Bad arguments')
}
const {encoding} = options
const buffer = Buffer.alloc(info.size)
const fd = archive.getFd()
if (!(fd >= 0)) throw createError(AsarError.NOT_FOUND, {asarPath, filePath})
logASARAccess(asarPath, filePath, info.offset)
fs.readSync(fd, buffer, 0, info.size, info.offset)
return (encoding) ? buffer.toString(encoding) : buffer
}
const {readdir} = fs
fs.readdir = function (pathArgument, callback) {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return readdir.apply(this, arguments)
const archive = getOrCreateArchive(asarPath)
if (!archive) {
const error = createError(AsarError.INVALID_ARCHIVE, {asarPath})
nextTick(callback, [error])
return
}
const files = archive.readdir(filePath)
if (!files) {
const error = createError(AsarError.NOT_FOUND, {asarPath, filePath})
nextTick(callback, [error])
return
}
nextTick(callback, [null, files])
}
const {readdirSync} = fs
fs.readdirSync = function (pathArgument) {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return readdirSync.apply(this, arguments)
const archive = getOrCreateArchive(asarPath)
if (!archive) {
throw createError(AsarError.INVALID_ARCHIVE, {asarPath})
}
const files = archive.readdir(filePath)
if (!files) {
throw createError(AsarError.NOT_FOUND, {asarPath, filePath})
}
return files
}
const {internalModuleReadJSON} = process.binding('fs')
process.binding('fs').internalModuleReadJSON = pathArgument => {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return internalModuleReadJSON(pathArgument)
const archive = getOrCreateArchive(asarPath)
if (!archive) return
const info = archive.getFileInfo(filePath)
if (!info) return
if (info.size === 0) return ''
if (info.unpacked) {
const realPath = archive.copyFileOut(filePath)
return fs.readFileSync(realPath, {encoding: 'utf8'})
}
const buffer = Buffer.alloc(info.size)
const fd = archive.getFd()
if (!(fd >= 0)) return
logASARAccess(asarPath, filePath, info.offset)
fs.readSync(fd, buffer, 0, info.size, info.offset)
return buffer.toString('utf8')
}
const {internalModuleStat} = process.binding('fs')
process.binding('fs').internalModuleStat = pathArgument => {
const {isAsar, asarPath, filePath} = splitPath(pathArgument)
if (!isAsar) return internalModuleStat(pathArgument)
// -ENOENT
const archive = getOrCreateArchive(asarPath)
if (!archive) return -34
// -ENOENT
const stats = archive.stat(filePath)
if (!stats) return -34
return (stats.isDirectory) ? 1 : 0
}
// Calling mkdir for directory inside asar archive should throw ENOTDIR
// error, but on Windows it throws ENOENT.
// This is to work around the recursive looping bug of mkdirp since it is
// widely used.
if (process.platform === 'win32') {
const {mkdir} = fs
fs.mkdir = (pathArgument, mode, callback) => {
if (typeof mode === 'function') {
callback = mode
mode = undefined
}
const {isAsar, filePath} = splitPath(pathArgument)
if (isAsar && filePath.length > 0) {
const error = createError(AsarError.NOT_DIR)
nextTick(callback, [error])
return
}
mkdir(pathArgument, mode, callback)
}
const {mkdirSync} = fs
fs.mkdirSync = function (pathArgument, mode) {
const {isAsar, filePath} = splitPath(pathArgument)
if (isAsar && filePath.length) throw createError(AsarError.NOT_DIR)
return mkdirSync(pathArgument, mode)
}
}
// Executing a command string containing a path to an asar
// archive confuses `childProcess.execFile`, which is internally
// called by `childProcess.{exec,execSync}`, causing
// Electron to consider the full command as a single path
// to an archive.
const {exec, execSync} = childProcess
childProcess.exec = invokeWithNoAsar(exec)
childProcess.exec[util.promisify.custom] = invokeWithNoAsar(exec[util.promisify.custom])
childProcess.execSync = invokeWithNoAsar(execSync)
function invokeWithNoAsar (func) {
return function () {
const processNoAsarOriginalValue = process.noAsar
process.noAsar = true
try {
return func.apply(this, arguments)
} finally {
process.noAsar = processNoAsarOriginalValue
}
}
}
overrideAPI(fs, 'open')
overrideAPI(childProcess, 'execFile')
overrideAPISync(process, 'dlopen', 1)
overrideAPISync(require('module')._extensions, '.node', 1)
overrideAPISync(fs, 'openSync')
overrideAPISync(childProcess, 'execFileSync')
}
})()