503 lines
14 KiB
JavaScript
503 lines
14 KiB
JavaScript
|
'use strict';
|
||
|
|
|
||
|
|
const Limiter = require('async-limiter');
|
||
|
|
const zlib = require('zlib');
|
||
|
|
|
||
|
|
const bufferUtil = require('./buffer-util');
|
||
|
|
const { kStatusCode, NOOP } = require('./constants');
|
||
|
|
|
||
|
|
const TRAILER = Buffer.from([0x00, 0x00, 0xff, 0xff]);
|
||
|
|
const EMPTY_BLOCK = Buffer.from([0x00]);
|
||
|
|
|
||
|
|
const kPerMessageDeflate = Symbol('permessage-deflate');
|
||
|
|
const kTotalLength = Symbol('total-length');
|
||
|
|
const kCallback = Symbol('callback');
|
||
|
|
const kBuffers = Symbol('buffers');
|
||
|
|
const kError = Symbol('error');
|
||
|
|
|
||
|
|
//
|
||
|
|
// We limit zlib concurrency, which prevents severe memory fragmentation
|
||
|
|
// as documented in https://github.com/nodejs/node/issues/8871#issuecomment-250915913
|
||
|
|
// and https://github.com/websockets/ws/issues/1202
|
||
|
|
//
|
||
|
|
// Intentionally global; it's the global thread pool that's an issue.
|
||
|
|
//
|
||
|
|
let zlibLimiter;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* permessage-deflate implementation.
|
||
|
|
*/
|
||
|
|
class PerMessageDeflate {
|
||
|
|
/**
|
||
|
|
* Creates a PerMessageDeflate instance.
|
||
|
|
*
|
||
|
|
* @param {Object} options Configuration options
|
||
|
|
* @param {Boolean} options.serverNoContextTakeover Request/accept disabling
|
||
|
|
* of server context takeover
|
||
|
|
* @param {Boolean} options.clientNoContextTakeover Advertise/acknowledge
|
||
|
|
* disabling of client context takeover
|
||
|
|
* @param {(Boolean|Number)} options.serverMaxWindowBits Request/confirm the
|
||
|
|
* use of a custom server window size
|
||
|
|
* @param {(Boolean|Number)} options.clientMaxWindowBits Advertise support
|
||
|
|
* for, or request, a custom client window size
|
||
|
|
* @param {Object} options.zlibDeflateOptions Options to pass to zlib on deflate
|
||
|
|
* @param {Object} options.zlibInflateOptions Options to pass to zlib on inflate
|
||
|
|
* @param {Number} options.threshold Size (in bytes) below which messages
|
||
|
|
* should not be compressed
|
||
|
|
* @param {Number} options.concurrencyLimit The number of concurrent calls to
|
||
|
|
* zlib
|
||
|
|
* @param {Boolean} isServer Create the instance in either server or client
|
||
|
|
* mode
|
||
|
|
* @param {Number} maxPayload The maximum allowed message length
|
||
|
|
*/
|
||
|
|
constructor(options, isServer, maxPayload) {
|
||
|
|
this._maxPayload = maxPayload | 0;
|
||
|
|
this._options = options || {};
|
||
|
|
this._threshold =
|
||
|
|
this._options.threshold !== undefined ? this._options.threshold : 1024;
|
||
|
|
this._isServer = !!isServer;
|
||
|
|
this._deflate = null;
|
||
|
|
this._inflate = null;
|
||
|
|
|
||
|
|
this.params = null;
|
||
|
|
|
||
|
|
if (!zlibLimiter) {
|
||
|
|
const concurrency =
|
||
|
|
this._options.concurrencyLimit !== undefined
|
||
|
|
? this._options.concurrencyLimit
|
||
|
|
: 10;
|
||
|
|
zlibLimiter = new Limiter({ concurrency });
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @type {String}
|
||
|
|
*/
|
||
|
|
static get extensionName() {
|
||
|
|
return 'permessage-deflate';
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Create an extension negotiation offer.
|
||
|
|
*
|
||
|
|
* @return {Object} Extension parameters
|
||
|
|
* @public
|
||
|
|
*/
|
||
|
|
offer() {
|
||
|
|
const params = {};
|
||
|
|
|
||
|
|
if (this._options.serverNoContextTakeover) {
|
||
|
|
params.server_no_context_takeover = true;
|
||
|
|
}
|
||
|
|
if (this._options.clientNoContextTakeover) {
|
||
|
|
params.client_no_context_takeover = true;
|
||
|
|
}
|
||
|
|
if (this._options.serverMaxWindowBits) {
|
||
|
|
params.server_max_window_bits = this._options.serverMaxWindowBits;
|
||
|
|
}
|
||
|
|
if (this._options.clientMaxWindowBits) {
|
||
|
|
params.client_max_window_bits = this._options.clientMaxWindowBits;
|
||
|
|
} else if (this._options.clientMaxWindowBits == null) {
|
||
|
|
params.client_max_window_bits = true;
|
||
|
|
}
|
||
|
|
|
||
|
|
return params;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Accept an extension negotiation offer/response.
|
||
|
|
*
|
||
|
|
* @param {Array} configurations The extension negotiation offers/reponse
|
||
|
|
* @return {Object} Accepted configuration
|
||
|
|
* @public
|
||
|
|
*/
|
||
|
|
accept(configurations) {
|
||
|
|
configurations = this.normalizeParams(configurations);
|
||
|
|
|
||
|
|
this.params = this._isServer
|
||
|
|
? this.acceptAsServer(configurations)
|
||
|
|
: this.acceptAsClient(configurations);
|
||
|
|
|
||
|
|
return this.params;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Releases all resources used by the extension.
|
||
|
|
*
|
||
|
|
* @public
|
||
|
|
*/
|
||
|
|
cleanup() {
|
||
|
|
if (this._inflate) {
|
||
|
|
this._inflate.close();
|
||
|
|
this._inflate = null;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (this._deflate) {
|
||
|
|
this._deflate.close();
|
||
|
|
this._deflate = null;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Accept an extension negotiation offer.
|
||
|
|
*
|
||
|
|
* @param {Array} offers The extension negotiation offers
|
||
|
|
* @return {Object} Accepted configuration
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
acceptAsServer(offers) {
|
||
|
|
const opts = this._options;
|
||
|
|
const accepted = offers.find((params) => {
|
||
|
|
if (
|
||
|
|
(opts.serverNoContextTakeover === false &&
|
||
|
|
params.server_no_context_takeover) ||
|
||
|
|
(params.server_max_window_bits &&
|
||
|
|
(opts.serverMaxWindowBits === false ||
|
||
|
|
(typeof opts.serverMaxWindowBits === 'number' &&
|
||
|
|
opts.serverMaxWindowBits > params.server_max_window_bits))) ||
|
||
|
|
(typeof opts.clientMaxWindowBits === 'number' &&
|
||
|
|
!params.client_max_window_bits)
|
||
|
|
) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
return true;
|
||
|
|
});
|
||
|
|
|
||
|
|
if (!accepted) {
|
||
|
|
throw new Error('None of the extension offers can be accepted');
|
||
|
|
}
|
||
|
|
|
||
|
|
if (opts.serverNoContextTakeover) {
|
||
|
|
accepted.server_no_context_takeover = true;
|
||
|
|
}
|
||
|
|
if (opts.clientNoContextTakeover) {
|
||
|
|
accepted.client_no_context_takeover = true;
|
||
|
|
}
|
||
|
|
if (typeof opts.serverMaxWindowBits === 'number') {
|
||
|
|
accepted.server_max_window_bits = opts.serverMaxWindowBits;
|
||
|
|
}
|
||
|
|
if (typeof opts.clientMaxWindowBits === 'number') {
|
||
|
|
accepted.client_max_window_bits = opts.clientMaxWindowBits;
|
||
|
|
} else if (
|
||
|
|
accepted.client_max_window_bits === true ||
|
||
|
|
opts.clientMaxWindowBits === false
|
||
|
|
) {
|
||
|
|
delete accepted.client_max_window_bits;
|
||
|
|
}
|
||
|
|
|
||
|
|
return accepted;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Accept the extension negotiation response.
|
||
|
|
*
|
||
|
|
* @param {Array} response The extension negotiation response
|
||
|
|
* @return {Object} Accepted configuration
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
acceptAsClient(response) {
|
||
|
|
const params = response[0];
|
||
|
|
|
||
|
|
if (
|
||
|
|
this._options.clientNoContextTakeover === false &&
|
||
|
|
params.client_no_context_takeover
|
||
|
|
) {
|
||
|
|
throw new Error('Unexpected parameter "client_no_context_takeover"');
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!params.client_max_window_bits) {
|
||
|
|
if (typeof this._options.clientMaxWindowBits === 'number') {
|
||
|
|
params.client_max_window_bits = this._options.clientMaxWindowBits;
|
||
|
|
}
|
||
|
|
} else if (
|
||
|
|
this._options.clientMaxWindowBits === false ||
|
||
|
|
(typeof this._options.clientMaxWindowBits === 'number' &&
|
||
|
|
params.client_max_window_bits > this._options.clientMaxWindowBits)
|
||
|
|
) {
|
||
|
|
throw new Error(
|
||
|
|
'Unexpected or invalid parameter "client_max_window_bits"'
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
return params;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Normalize parameters.
|
||
|
|
*
|
||
|
|
* @param {Array} configurations The extension negotiation offers/reponse
|
||
|
|
* @return {Array} The offers/response with normalized parameters
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
normalizeParams(configurations) {
|
||
|
|
configurations.forEach((params) => {
|
||
|
|
Object.keys(params).forEach((key) => {
|
||
|
|
var value = params[key];
|
||
|
|
|
||
|
|
if (value.length > 1) {
|
||
|
|
throw new Error(`Parameter "${key}" must have only a single value`);
|
||
|
|
}
|
||
|
|
|
||
|
|
value = value[0];
|
||
|
|
|
||
|
|
if (key === 'client_max_window_bits') {
|
||
|
|
if (value !== true) {
|
||
|
|
const num = +value;
|
||
|
|
if (!Number.isInteger(num) || num < 8 || num > 15) {
|
||
|
|
throw new TypeError(
|
||
|
|
`Invalid value for parameter "${key}": ${value}`
|
||
|
|
);
|
||
|
|
}
|
||
|
|
value = num;
|
||
|
|
} else if (!this._isServer) {
|
||
|
|
throw new TypeError(
|
||
|
|
`Invalid value for parameter "${key}": ${value}`
|
||
|
|
);
|
||
|
|
}
|
||
|
|
} else if (key === 'server_max_window_bits') {
|
||
|
|
const num = +value;
|
||
|
|
if (!Number.isInteger(num) || num < 8 || num > 15) {
|
||
|
|
throw new TypeError(
|
||
|
|
`Invalid value for parameter "${key}": ${value}`
|
||
|
|
);
|
||
|
|
}
|
||
|
|
value = num;
|
||
|
|
} else if (
|
||
|
|
key === 'client_no_context_takeover' ||
|
||
|
|
key === 'server_no_context_takeover'
|
||
|
|
) {
|
||
|
|
if (value !== true) {
|
||
|
|
throw new TypeError(
|
||
|
|
`Invalid value for parameter "${key}": ${value}`
|
||
|
|
);
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
throw new Error(`Unknown parameter "${key}"`);
|
||
|
|
}
|
||
|
|
|
||
|
|
params[key] = value;
|
||
|
|
});
|
||
|
|
});
|
||
|
|
|
||
|
|
return configurations;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Decompress data. Concurrency limited by async-limiter.
|
||
|
|
*
|
||
|
|
* @param {Buffer} data Compressed data
|
||
|
|
* @param {Boolean} fin Specifies whether or not this is the last fragment
|
||
|
|
* @param {Function} callback Callback
|
||
|
|
* @public
|
||
|
|
*/
|
||
|
|
decompress(data, fin, callback) {
|
||
|
|
zlibLimiter.push((done) => {
|
||
|
|
this._decompress(data, fin, (err, result) => {
|
||
|
|
done();
|
||
|
|
callback(err, result);
|
||
|
|
});
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Compress data. Concurrency limited by async-limiter.
|
||
|
|
*
|
||
|
|
* @param {Buffer} data Data to compress
|
||
|
|
* @param {Boolean} fin Specifies whether or not this is the last fragment
|
||
|
|
* @param {Function} callback Callback
|
||
|
|
* @public
|
||
|
|
*/
|
||
|
|
compress(data, fin, callback) {
|
||
|
|
zlibLimiter.push((done) => {
|
||
|
|
this._compress(data, fin, (err, result) => {
|
||
|
|
done();
|
||
|
|
callback(err, result);
|
||
|
|
});
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Decompress data.
|
||
|
|
*
|
||
|
|
* @param {Buffer} data Compressed data
|
||
|
|
* @param {Boolean} fin Specifies whether or not this is the last fragment
|
||
|
|
* @param {Function} callback Callback
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
_decompress(data, fin, callback) {
|
||
|
|
const endpoint = this._isServer ? 'client' : 'server';
|
||
|
|
|
||
|
|
if (!this._inflate) {
|
||
|
|
const key = `${endpoint}_max_window_bits`;
|
||
|
|
const windowBits =
|
||
|
|
typeof this.params[key] !== 'number'
|
||
|
|
? zlib.Z_DEFAULT_WINDOWBITS
|
||
|
|
: this.params[key];
|
||
|
|
|
||
|
|
this._inflate = zlib.createInflateRaw(
|
||
|
|
Object.assign({}, this._options.zlibInflateOptions, { windowBits })
|
||
|
|
);
|
||
|
|
this._inflate[kPerMessageDeflate] = this;
|
||
|
|
this._inflate[kTotalLength] = 0;
|
||
|
|
this._inflate[kBuffers] = [];
|
||
|
|
this._inflate.on('error', inflateOnError);
|
||
|
|
this._inflate.on('data', inflateOnData);
|
||
|
|
}
|
||
|
|
|
||
|
|
this._inflate[kCallback] = callback;
|
||
|
|
|
||
|
|
this._inflate.write(data);
|
||
|
|
if (fin) this._inflate.write(TRAILER);
|
||
|
|
|
||
|
|
this._inflate.flush(() => {
|
||
|
|
const err = this._inflate[kError];
|
||
|
|
|
||
|
|
if (err) {
|
||
|
|
this._inflate.close();
|
||
|
|
this._inflate = null;
|
||
|
|
callback(err);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
const data = bufferUtil.concat(
|
||
|
|
this._inflate[kBuffers],
|
||
|
|
this._inflate[kTotalLength]
|
||
|
|
);
|
||
|
|
|
||
|
|
if (fin && this.params[`${endpoint}_no_context_takeover`]) {
|
||
|
|
this._inflate.close();
|
||
|
|
this._inflate = null;
|
||
|
|
} else {
|
||
|
|
this._inflate[kTotalLength] = 0;
|
||
|
|
this._inflate[kBuffers] = [];
|
||
|
|
}
|
||
|
|
|
||
|
|
callback(null, data);
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Compress data.
|
||
|
|
*
|
||
|
|
* @param {Buffer} data Data to compress
|
||
|
|
* @param {Boolean} fin Specifies whether or not this is the last fragment
|
||
|
|
* @param {Function} callback Callback
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
_compress(data, fin, callback) {
|
||
|
|
if (!data || data.length === 0) {
|
||
|
|
process.nextTick(callback, null, EMPTY_BLOCK);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
const endpoint = this._isServer ? 'server' : 'client';
|
||
|
|
|
||
|
|
if (!this._deflate) {
|
||
|
|
const key = `${endpoint}_max_window_bits`;
|
||
|
|
const windowBits =
|
||
|
|
typeof this.params[key] !== 'number'
|
||
|
|
? zlib.Z_DEFAULT_WINDOWBITS
|
||
|
|
: this.params[key];
|
||
|
|
|
||
|
|
this._deflate = zlib.createDeflateRaw(
|
||
|
|
Object.assign({}, this._options.zlibDeflateOptions, { windowBits })
|
||
|
|
);
|
||
|
|
|
||
|
|
this._deflate[kTotalLength] = 0;
|
||
|
|
this._deflate[kBuffers] = [];
|
||
|
|
|
||
|
|
//
|
||
|
|
// An `'error'` event is emitted, only on Node.js < 10.0.0, if the
|
||
|
|
// `zlib.DeflateRaw` instance is closed while data is being processed.
|
||
|
|
// This can happen if `PerMessageDeflate#cleanup()` is called at the wrong
|
||
|
|
// time due to an abnormal WebSocket closure.
|
||
|
|
//
|
||
|
|
this._deflate.on('error', NOOP);
|
||
|
|
this._deflate.on('data', deflateOnData);
|
||
|
|
}
|
||
|
|
|
||
|
|
this._deflate.write(data);
|
||
|
|
this._deflate.flush(zlib.Z_SYNC_FLUSH, () => {
|
||
|
|
if (!this._deflate) {
|
||
|
|
//
|
||
|
|
// This `if` statement is only needed for Node.js < 10.0.0 because as of
|
||
|
|
// commit https://github.com/nodejs/node/commit/5e3f5164, the flush
|
||
|
|
// callback is no longer called if the deflate stream is closed while
|
||
|
|
// data is being processed.
|
||
|
|
//
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
var data = bufferUtil.concat(
|
||
|
|
this._deflate[kBuffers],
|
||
|
|
this._deflate[kTotalLength]
|
||
|
|
);
|
||
|
|
|
||
|
|
if (fin) data = data.slice(0, data.length - 4);
|
||
|
|
|
||
|
|
if (fin && this.params[`${endpoint}_no_context_takeover`]) {
|
||
|
|
this._deflate.close();
|
||
|
|
this._deflate = null;
|
||
|
|
} else {
|
||
|
|
this._deflate[kTotalLength] = 0;
|
||
|
|
this._deflate[kBuffers] = [];
|
||
|
|
}
|
||
|
|
|
||
|
|
callback(null, data);
|
||
|
|
});
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
module.exports = PerMessageDeflate;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* The listener of the `zlib.DeflateRaw` stream `'data'` event.
|
||
|
|
*
|
||
|
|
* @param {Buffer} chunk A chunk of data
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
function deflateOnData(chunk) {
|
||
|
|
this[kBuffers].push(chunk);
|
||
|
|
this[kTotalLength] += chunk.length;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* The listener of the `zlib.InflateRaw` stream `'data'` event.
|
||
|
|
*
|
||
|
|
* @param {Buffer} chunk A chunk of data
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
function inflateOnData(chunk) {
|
||
|
|
this[kTotalLength] += chunk.length;
|
||
|
|
|
||
|
|
if (
|
||
|
|
this[kPerMessageDeflate]._maxPayload < 1 ||
|
||
|
|
this[kTotalLength] <= this[kPerMessageDeflate]._maxPayload
|
||
|
|
) {
|
||
|
|
this[kBuffers].push(chunk);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
this[kError] = new RangeError('Max payload size exceeded');
|
||
|
|
this[kError][kStatusCode] = 1009;
|
||
|
|
this.removeListener('data', inflateOnData);
|
||
|
|
this.reset();
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* The listener of the `zlib.InflateRaw` stream `'error'` event.
|
||
|
|
*
|
||
|
|
* @param {Error} err The emitted error
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
function inflateOnError(err) {
|
||
|
|
//
|
||
|
|
// There is no need to call `Zlib#close()` as the handle is automatically
|
||
|
|
// closed when an error is emitted.
|
||
|
|
//
|
||
|
|
this[kPerMessageDeflate]._inflate = null;
|
||
|
|
err[kStatusCode] = 1007;
|
||
|
|
this[kCallback](err);
|
||
|
|
}
|