/*! * send * Copyright(c) 2012 TJ Holowaychuk * Copyright(c) 2014-2016 Douglas Christopher Wilson * MIT Licensed */ 'use strict' /** * Module dependencies. * @private */ var createError = require('http-errors') var debug = require('debug')('send') var deprecate = require('depd')('send') var destroy = require('destroy') var encodeUrl = require('encodeurl') var escapeHtml = require('escape-html') var etag = require('etag') var fresh = require('fresh') var fs = require('fs') var mime = require('mime') var ms = require('ms') var onFinished = require('on-finished') var parseRange = require('range-parser') var path = require('path') var statuses = require('statuses') var Stream = require('stream') var util = require('util') /** * Path function references. * @private */ var extname = path.extname var join = path.join var normalize = path.normalize var resolve = path.resolve var sep = path.sep /** * Regular expression for identifying a bytes Range header. * @private */ var BYTES_RANGE_REGEXP = /^ *bytes=/ /** * Maximum value allowed for the max age. * @private */ var MAX_MAXAGE = 60 * 60 * 24 * 365 * 1000 // 1 year /** * Regular expression to match a path with a directory up component. * @private */ var UP_PATH_REGEXP = /(?:^|[\\/])\.\.(?:[\\/]|$)/ /** * Module exports. * @public */ module.exports = send module.exports.mime = mime /** * Return a `SendStream` for `req` and `path`. * * @param {object} req * @param {string} path * @param {object} [options] * @return {SendStream} * @public */ function send (req, path, options) { return new SendStream(req, path, options) } /** * Initialize a `SendStream` with the given `path`. * * @param {Request} req * @param {String} path * @param {object} [options] * @private */ function SendStream (req, path, options) { Stream.call(this) var opts = options || {} this.options = opts this.path = path this.req = req this._acceptRanges = opts.acceptRanges !== undefined ? Boolean(opts.acceptRanges) : true this._cacheControl = opts.cacheControl !== undefined ? Boolean(opts.cacheControl) : true this._etag = opts.etag !== undefined ? Boolean(opts.etag) : true this._dotfiles = opts.dotfiles !== undefined ? opts.dotfiles : 'ignore' if (this._dotfiles !== 'ignore' && this._dotfiles !== 'allow' && this._dotfiles !== 'deny') { throw new TypeError('dotfiles option must be "allow", "deny", or "ignore"') } this._hidden = Boolean(opts.hidden) if (opts.hidden !== undefined) { deprecate('hidden: use dotfiles: \'' + (this._hidden ? 'allow' : 'ignore') + '\' instead') } // legacy support if (opts.dotfiles === undefined) { this._dotfiles = undefined } this._extensions = opts.extensions !== undefined ? normalizeList(opts.extensions, 'extensions option') : [] this._immutable = opts.immutable !== undefined ? Boolean(opts.immutable) : false this._index = opts.index !== undefined ? normalizeList(opts.index, 'index option') : ['index.html'] this._lastModified = opts.lastModified !== undefined ? Boolean(opts.lastModified) : true this._maxage = opts.maxAge || opts.maxage this._maxage = typeof this._maxage === 'string' ? ms(this._maxage) : Number(this._maxage) this._maxage = !isNaN(this._maxage) ? Math.min(Math.max(0, this._maxage), MAX_MAXAGE) : 0 this._root = opts.root ? resolve(opts.root) : null if (!this._root && opts.from) { this.from(opts.from) } } /** * Inherits from `Stream`. */ util.inherits(SendStream, Stream) /** * Enable or disable etag generation. * * @param {Boolean} val * @return {SendStream} * @api public */ SendStream.prototype.etag = deprecate.function(function etag (val) { this._etag = Boolean(val) debug('etag %s', this._etag) return this }, 'send.etag: pass etag as option') /** * Enable or disable "hidden" (dot) files. * * @param {Boolean} path * @return {SendStream} * @api public */ SendStream.prototype.hidden = deprecate.function(function hidden (val) { this._hidden = Boolean(val) this._dotfiles = undefined debug('hidden %s', this._hidden) return this }, 'send.hidden: use dotfiles option') /** * Set index `paths`, set to a falsy * value to disable index support. * * @param {String|Boolean|Array} paths * @return {SendStream} * @api public */ SendStream.prototype.index = deprecate.function(function index (paths) { var index = !paths ? [] : normalizeList(paths, 'paths argument') debug('index %o', paths) this._index = index return this }, 'send.index: pass index as option') /** * Set root `path`. * * @param {String} path * @return {SendStream} * @api public */ SendStream.prototype.root = function root (path) { this._root = resolve(String(path)) debug('root %s', this._root) return this } SendStream.prototype.from = deprecate.function(SendStream.prototype.root, 'send.from: pass root as option') SendStream.prototype.root = deprecate.function(SendStream.prototype.root, 'send.root: pass root as option') /** * Set max-age to `maxAge`. * * @param {Number} maxAge * @return {SendStream} * @api public */ SendStream.prototype.maxage = deprecate.function(function maxage (maxAge) { this._maxage = typeof maxAge === 'string' ? ms(maxAge) : Number(maxAge) this._maxage = !isNaN(this._maxage) ? Math.min(Math.max(0, this._maxage), MAX_MAXAGE) : 0 debug('max-age %d', this._maxage) return this }, 'send.maxage: pass maxAge as option') /** * Emit error with `status`. * * @param {number} status * @param {Error} [err] * @private */ SendStream.prototype.error = function error (status, err) { // emit if listeners instead of responding if (hasListeners(this, 'error')) { return this.emit('error', createError(status, err, { expose: false })) } var res = this.res var msg = statuses[status] || String(status) var doc = createHtmlDocument('Error', escapeHtml(msg)) // clear existing headers clearHeaders(res) // add error headers if (err && err.headers) { setHeaders(res, err.headers) } // send basic response res.statusCode = status res.setHeader('Content-Type', 'text/html; charset=UTF-8') res.setHeader('Content-Length', Buffer.byteLength(doc)) res.setHeader('Content-Security-Policy', "default-src 'self'") res.setHeader('X-Content-Type-Options', 'nosniff') res.end(doc) } /** * Check if the pathname ends with "/". * * @return {boolean} * @private */ SendStream.prototype.hasTrailingSlash = function hasTrailingSlash () { return this.path[this.path.length - 1] === '/' } /** * Check if this is a conditional GET request. * * @return {Boolean} * @api private */ SendStream.prototype.isConditionalGET = function isConditionalGET () { return this.req.headers['if-match'] || this.req.headers['if-unmodified-since'] || this.req.headers['if-none-match'] || this.req.headers['if-modified-since'] } /** * Check if the request preconditions failed. * * @return {boolean} * @private */ SendStream.prototype.isPreconditionFailure = function isPreconditionFailure () { var req = this.req var res = this.res // if-match var match = req.headers['if-match'] if (match) { var etag = res.getHeader('ETag') return !etag || (match !== '*' && parseTokenList(match).every(function (match) { return match !== etag && match !== 'W/' + etag && 'W/' + match !== etag })) } // if-unmodified-since var unmodifiedSince = parseHttpDate(req.headers['if-unmodified-since']) if (!isNaN(unmodifiedSince)) { var lastModified = parseHttpDate(res.getHeader('Last-Modified')) return isNaN(lastModified) || lastModified > unmodifiedSince } return false } /** * Strip content-* header fields. * * @private */ SendStream.prototype.removeContentHeaderFields = function removeContentHeaderFields () { var res = this.res var headers = getHeaderNames(res) for (var i = 0; i < headers.length; i++) { var header = headers[i] if (header.substr(0, 8) === 'content-' && header !== 'content-location') { res.removeHeader(header) } } } /** * Respond with 304 not modified. * * @api private */ SendStream.prototype.notModified = function notModified () { var res = this.res debug('not modified') this.removeContentHeaderFields() res.statusCode = 304 res.end() } /** * Raise error that headers already sent. * * @api private */ SendStream.prototype.headersAlreadySent = function headersAlreadySent () { var err = new Error('Can\'t set headers after they are sent.') debug('headers already sent') this.error(500, err) } /** * Check if the request is cacheable, aka * responded with 2xx or 304 (see RFC 2616 section 14.2{5,6}). * * @return {Boolean} * @api private */ SendStream.prototype.isCachable = function isCachable () { var statusCode = this.res.statusCode return (statusCode >= 200 && statusCode < 300) || statusCode === 304 } /** * Handle stat() error. * * @param {Error} error * @private */ SendStream.prototype.onStatError = function onStatError (error) { switch (error.code) { case 'ENAMETOOLONG': case 'ENOENT': case 'ENOTDIR': this.error(404, error) break default: this.error(500, error) break } } /** * Check if the cache is fresh. * * @return {Boolean} * @api private */ SendStream.prototype.isFresh = function isFresh () { return fresh(this.req.headers, { 'etag': this.res.getHeader('ETag'), 'last-modified': this.res.getHeader('Last-Modified') }) } /** * Check if the range is fresh. * * @return {Boolean} * @api private */ SendStream.prototype.isRangeFresh = function isRangeFresh () { var ifRange = this.req.headers['if-range'] if (!ifRange) { return true } // if-range as etag if (ifRange.indexOf('"') !== -1) { var etag = this.res.getHeader('ETag') return Boolean(etag && ifRange.indexOf(etag) !== -1) } // if-range as modified date var lastModified = this.res.getHeader('Last-Modified') return parseHttpDate(lastModified) <= parseHttpDate(ifRange) } /** * Redirect to path. * * @param {string} path * @private */ SendStream.prototype.redirect = function redirect (path) { var res = this.res if (hasListeners(this, 'directory')) { this.emit('directory', res, path) return } if (this.hasTrailingSlash()) { this.error(403) return } var loc = encodeUrl(collapseLeadingSlashes(this.path + '/')) var doc = createHtmlDocument('Redirecting', 'Redirecting to <a href="' + escapeHtml(loc) + '">' + escapeHtml(loc) + '</a>') // redirect res.statusCode = 301 res.setHeader('Content-Type', 'text/html; charset=UTF-8') res.setHeader('Content-Length', Buffer.byteLength(doc)) res.setHeader('Content-Security-Policy', "default-src 'self'") res.setHeader('X-Content-Type-Options', 'nosniff') res.setHeader('Location', loc) res.end(doc) } /** * Pipe to `res. * * @param {Stream} res * @return {Stream} res * @api public */ SendStream.prototype.pipe = function pipe (res) { // root path var root = this._root // references this.res = res // decode the path var path = decode(this.path) if (path === -1) { this.error(400) return res } // null byte(s) if (~path.indexOf('\0')) { this.error(400) return res } var parts if (root !== null) { // normalize if (path) { path = normalize('.' + sep + path) } // malicious path if (UP_PATH_REGEXP.test(path)) { debug('malicious path "%s"', path) this.error(403) return res } // explode path parts parts = path.split(sep) // join / normalize from optional root dir path = normalize(join(root, path)) root = normalize(root + sep) } else { // ".." is malicious without "root" if (UP_PATH_REGEXP.test(path)) { debug('malicious path "%s"', path) this.error(403) return res } // explode path parts parts = normalize(path).split(sep) // resolve the path path = resolve(path) } // dotfile handling if (containsDotFile(parts)) { var access = this._dotfiles // legacy support if (access === undefined) { access = parts[parts.length - 1][0] === '.' ? (this._hidden ? 'allow' : 'ignore') : 'allow' } debug('%s dotfile "%s"', access, path) switch (access) { case 'allow': break case 'deny': this.error(403) return res case 'ignore': default: this.error(404) return res } } // index file support if (this._index.length && this.hasTrailingSlash()) { this.sendIndex(path) return res } this.sendFile(path) return res } /** * Transfer `path`. * * @param {String} path * @api public */ SendStream.prototype.send = function send (path, stat) { var len = stat.size var options = this.options var opts = {} var res = this.res var req = this.req var ranges = req.headers.range var offset = options.start || 0 if (headersSent(res)) { // impossible to send now this.headersAlreadySent() return } debug('pipe "%s"', path) // set header fields this.setHeader(path, stat) // set content-type this.type(path) // conditional GET support if (this.isConditionalGET()) { if (this.isPreconditionFailure()) { this.error(412) return } if (this.isCachable() && this.isFresh()) { this.notModified() return } } // adjust len to start/end options len = Math.max(0, len - offset) if (options.end !== undefined) { var bytes = options.end - offset + 1 if (len > bytes) len = bytes } // Range support if (this._acceptRanges && BYTES_RANGE_REGEXP.test(ranges)) { // parse ranges = parseRange(len, ranges, { combine: true }) // If-Range support if (!this.isRangeFresh()) { debug('range stale') ranges = -2 } // unsatisfiable if (ranges === -1) { debug('range unsatisfiable') // Content-Range res.setHeader('Content-Range', contentRange('bytes', len)) // 416 Requested Range Not Satisfiable return this.error(416, { headers: {'Content-Range': res.getHeader('Content-Range')} }) } // valid (syntactically invalid/multiple ranges are treated as a regular response) if (ranges !== -2 && ranges.length === 1) { debug('range %j', ranges) // Content-Range res.statusCode = 206 res.setHeader('Content-Range', contentRange('bytes', len, ranges[0])) // adjust for requested range offset += ranges[0].start len = ranges[0].end - ranges[0].start + 1 } } // clone options for (var prop in options) { opts[prop] = options[prop] } // set read options opts.start = offset opts.end = Math.max(offset, offset + len - 1) // content-length res.setHeader('Content-Length', len) // HEAD support if (req.method === 'HEAD') { res.end() return } this.stream(path, opts) } /** * Transfer file for `path`. * * @param {String} path * @api private */ SendStream.prototype.sendFile = function sendFile (path) { var i = 0 var self = this debug('stat "%s"', path) fs.stat(path, function onstat (err, stat) { if (err && err.code === 'ENOENT' && !extname(path) && path[path.length - 1] !== sep) { // not found, check extensions return next(err) } if (err) return self.onStatError(err) if (stat.isDirectory()) return self.redirect(path) self.emit('file', path, stat) self.send(path, stat) }) function next (err) { if (self._extensions.length <= i) { return err ? self.onStatError(err) : self.error(404) } var p = path + '.' + self._extensions[i++] debug('stat "%s"', p) fs.stat(p, function (err, stat) { if (err) return next(err) if (stat.isDirectory()) return next() self.emit('file', p, stat) self.send(p, stat) }) } } /** * Transfer index for `path`. * * @param {String} path * @api private */ SendStream.prototype.sendIndex = function sendIndex (path) { var i = -1 var self = this function next (err) { if (++i >= self._index.length) { if (err) return self.onStatError(err) return self.error(404) } var p = join(path, self._index[i]) debug('stat "%s"', p) fs.stat(p, function (err, stat) { if (err) return next(err) if (stat.isDirectory()) return next() self.emit('file', p, stat) self.send(p, stat) }) } next() } /** * Stream `path` to the response. * * @param {String} path * @param {Object} options * @api private */ SendStream.prototype.stream = function stream (path, options) { // TODO: this is all lame, refactor meeee var finished = false var self = this var res = this.res // pipe var stream = fs.createReadStream(path, options) this.emit('stream', stream) stream.pipe(res) // response finished, done with the fd onFinished(res, function onfinished () { finished = true destroy(stream) }) // error handling code-smell stream.on('error', function onerror (err) { // request already finished if (finished) return // clean up stream finished = true destroy(stream) // error self.onStatError(err) }) // end stream.on('end', function onend () { self.emit('end') }) } /** * Set content-type based on `path` * if it hasn't been explicitly set. * * @param {String} path * @api private */ SendStream.prototype.type = function type (path) { var res = this.res if (res.getHeader('Content-Type')) return var type = mime.lookup(path) if (!type) { debug('no content-type') return } var charset = mime.charsets.lookup(type) debug('content-type %s', type) res.setHeader('Content-Type', type + (charset ? '; charset=' + charset : '')) } /** * Set response header fields, most * fields may be pre-defined. * * @param {String} path * @param {Object} stat * @api private */ SendStream.prototype.setHeader = function setHeader (path, stat) { var res = this.res this.emit('headers', res, path, stat) if (this._acceptRanges && !res.getHeader('Accept-Ranges')) { debug('accept ranges') res.setHeader('Accept-Ranges', 'bytes') } if (this._cacheControl && !res.getHeader('Cache-Control')) { var cacheControl = 'public, max-age=' + Math.floor(this._maxage / 1000) if (this._immutable) { cacheControl += ', immutable' } debug('cache-control %s', cacheControl) res.setHeader('Cache-Control', cacheControl) } if (this._lastModified && !res.getHeader('Last-Modified')) { var modified = stat.mtime.toUTCString() debug('modified %s', modified) res.setHeader('Last-Modified', modified) } if (this._etag && !res.getHeader('ETag')) { var val = etag(stat) debug('etag %s', val) res.setHeader('ETag', val) } } /** * Clear all headers from a response. * * @param {object} res * @private */ function clearHeaders (res) { var headers = getHeaderNames(res) for (var i = 0; i < headers.length; i++) { res.removeHeader(headers[i]) } } /** * Collapse all leading slashes into a single slash * * @param {string} str * @private */ function collapseLeadingSlashes (str) { for (var i = 0; i < str.length; i++) { if (str[i] !== '/') { break } } return i > 1 ? '/' + str.substr(i) : str } /** * Determine if path parts contain a dotfile. * * @api private */ function containsDotFile (parts) { for (var i = 0; i < parts.length; i++) { var part = parts[i] if (part.length > 1 && part[0] === '.') { return true } } return false } /** * Create a Content-Range header. * * @param {string} type * @param {number} size * @param {array} [range] */ function contentRange (type, size, range) { return type + ' ' + (range ? range.start + '-' + range.end : '*') + '/' + size } /** * Create a minimal HTML document. * * @param {string} title * @param {string} body * @private */ function createHtmlDocument (title, body) { return '<!DOCTYPE html>\n' + '<html lang="en">\n' + '<head>\n' + '<meta charset="utf-8">\n' + '<title>' + title + '</title>\n' + '</head>\n' + '<body>\n' + '<pre>' + body + '</pre>\n' + '</body>\n' + '<html>\n' } /** * decodeURIComponent. * * Allows V8 to only deoptimize this fn instead of all * of send(). * * @param {String} path * @api private */ function decode (path) { try { return decodeURIComponent(path) } catch (err) { return -1 } } /** * Get the header names on a respnse. * * @param {object} res * @returns {array[string]} * @private */ function getHeaderNames (res) { return typeof res.getHeaderNames !== 'function' ? Object.keys(res._headers || {}) : res.getHeaderNames() } /** * Determine if emitter has listeners of a given type. * * The way to do this check is done three different ways in Node.js >= 0.8 * so this consolidates them into a minimal set using instance methods. * * @param {EventEmitter} emitter * @param {string} type * @returns {boolean} * @private */ function hasListeners (emitter, type) { var count = typeof emitter.listenerCount !== 'function' ? emitter.listeners(type).length : emitter.listenerCount(type) return count > 0 } /** * Determine if the response headers have been sent. * * @param {object} res * @returns {boolean} * @private */ function headersSent (res) { return typeof res.headersSent !== 'boolean' ? Boolean(res._header) : res.headersSent } /** * Normalize the index option into an array. * * @param {boolean|string|array} val * @param {string} name * @private */ function normalizeList (val, name) { var list = [].concat(val || []) for (var i = 0; i < list.length; i++) { if (typeof list[i] !== 'string') { throw new TypeError(name + ' must be array of strings or false') } } return list } /** * Parse an HTTP Date into a number. * * @param {string} date * @private */ function parseHttpDate (date) { var timestamp = date && Date.parse(date) return typeof timestamp === 'number' ? timestamp : NaN } /** * Parse a HTTP token list. * * @param {string} str * @private */ function parseTokenList (str) { var end = 0 var list = [] var start = 0 // gather tokens for (var i = 0, len = str.length; i < len; i++) { switch (str.charCodeAt(i)) { case 0x20: /* */ if (start === end) { start = end = i + 1 } break case 0x2c: /* , */ list.push(str.substring(start, end)) start = end = i + 1 break default: end = i + 1 break } } // final token list.push(str.substring(start, end)) return list } /** * Set an object of headers on a response. * * @param {object} res * @param {object} headers * @private */ function setHeaders (res, headers) { var keys = Object.keys(headers) for (var i = 0; i < keys.length; i++) { var key = keys[i] res.setHeader(key, headers[key]) } }