+++ /dev/null
-'use strict';
-
-const stream = require('stream');
-
-const PerMessageDeflate = require('./permessage-deflate');
-const bufferUtil = require('./buffer-util');
-const validation = require('./validation');
-const constants = require('./constants');
-
-const GET_INFO = 0;
-const GET_PAYLOAD_LENGTH_16 = 1;
-const GET_PAYLOAD_LENGTH_64 = 2;
-const GET_MASK = 3;
-const GET_DATA = 4;
-const INFLATING = 5;
-
-/**
- * HyBi Receiver implementation.
- *
- * @extends stream.Writable
- */
-class Receiver extends stream.Writable {
- /**
- * Creates a Receiver instance.
- *
- * @param {String} binaryType The type for binary data
- * @param {Object} extensions An object containing the negotiated extensions
- * @param {Number} maxPayload The maximum allowed message length
- */
- constructor (binaryType, extensions, maxPayload) {
- super();
-
- this._binaryType = binaryType || constants.BINARY_TYPES[0];
- this[constants.kWebSocket] = undefined;
- this._extensions = extensions || {};
- this._maxPayload = maxPayload | 0;
-
- this._bufferedBytes = 0;
- this._buffers = [];
-
- this._compressed = false;
- this._payloadLength = 0;
- this._mask = undefined;
- this._fragmented = 0;
- this._masked = false;
- this._fin = false;
- this._opcode = 0;
-
- this._totalPayloadLength = 0;
- this._messageLength = 0;
- this._fragments = [];
-
- this._state = GET_INFO;
- this._loop = false;
- }
-
- /**
- * Implements `Writable.prototype._write()`.
- *
- * @param {Buffer} chunk The chunk of data to write
- * @param {String} encoding The character encoding of `chunk`
- * @param {Function} cb Callback
- */
- _write (chunk, encoding, cb) {
- if (this._opcode === 0x08) return cb();
-
- this._bufferedBytes += chunk.length;
- this._buffers.push(chunk);
- this.startLoop(cb);
- }
-
- /**
- * Consumes `n` bytes from the buffered data.
- *
- * @param {Number} n The number of bytes to consume
- * @return {Buffer} The consumed bytes
- * @private
- */
- consume (n) {
- this._bufferedBytes -= n;
-
- if (n === this._buffers[0].length) return this._buffers.shift();
-
- if (n < this._buffers[0].length) {
- const buf = this._buffers[0];
- this._buffers[0] = buf.slice(n);
- return buf.slice(0, n);
- }
-
- const dst = Buffer.allocUnsafe(n);
-
- do {
- const buf = this._buffers[0];
-
- if (n >= buf.length) {
- this._buffers.shift().copy(dst, dst.length - n);
- } else {
- buf.copy(dst, dst.length - n, 0, n);
- this._buffers[0] = buf.slice(n);
- }
-
- n -= buf.length;
- } while (n > 0);
-
- return dst;
- }
-
- /**
- * Starts the parsing loop.
- *
- * @param {Function} cb Callback
- * @private
- */
- startLoop (cb) {
- var err;
- this._loop = true;
-
- do {
- switch (this._state) {
- case GET_INFO:
- err = this.getInfo();
- break;
- case GET_PAYLOAD_LENGTH_16:
- err = this.getPayloadLength16();
- break;
- case GET_PAYLOAD_LENGTH_64:
- err = this.getPayloadLength64();
- break;
- case GET_MASK:
- this.getMask();
- break;
- case GET_DATA:
- err = this.getData(cb);
- break;
- default: // `INFLATING`
- this._loop = false;
- return;
- }
- } while (this._loop);
-
- cb(err);
- }
-
- /**
- * Reads the first two bytes of a frame.
- *
- * @return {(RangeError|undefined)} A possible error
- * @private
- */
- getInfo () {
- if (this._bufferedBytes < 2) {
- this._loop = false;
- return;
- }
-
- const buf = this.consume(2);
-
- if ((buf[0] & 0x30) !== 0x00) {
- this._loop = false;
- return error(RangeError, 'RSV2 and RSV3 must be clear', true, 1002);
- }
-
- const compressed = (buf[0] & 0x40) === 0x40;
-
- if (compressed && !this._extensions[PerMessageDeflate.extensionName]) {
- this._loop = false;
- return error(RangeError, 'RSV1 must be clear', true, 1002);
- }
-
- this._fin = (buf[0] & 0x80) === 0x80;
- this._opcode = buf[0] & 0x0f;
- this._payloadLength = buf[1] & 0x7f;
-
- if (this._opcode === 0x00) {
- if (compressed) {
- this._loop = false;
- return error(RangeError, 'RSV1 must be clear', true, 1002);
- }
-
- if (!this._fragmented) {
- this._loop = false;
- return error(RangeError, 'invalid opcode 0', true, 1002);
- }
-
- this._opcode = this._fragmented;
- } else if (this._opcode === 0x01 || this._opcode === 0x02) {
- if (this._fragmented) {
- this._loop = false;
- return error(RangeError, `invalid opcode ${this._opcode}`, true, 1002);
- }
-
- this._compressed = compressed;
- } else if (this._opcode > 0x07 && this._opcode < 0x0b) {
- if (!this._fin) {
- this._loop = false;
- return error(RangeError, 'FIN must be set', true, 1002);
- }
-
- if (compressed) {
- this._loop = false;
- return error(RangeError, 'RSV1 must be clear', true, 1002);
- }
-
- if (this._payloadLength > 0x7d) {
- this._loop = false;
- return error(
- RangeError,
- `invalid payload length ${this._payloadLength}`,
- true,
- 1002
- );
- }
- } else {
- this._loop = false;
- return error(RangeError, `invalid opcode ${this._opcode}`, true, 1002);
- }
-
- if (!this._fin && !this._fragmented) this._fragmented = this._opcode;
- this._masked = (buf[1] & 0x80) === 0x80;
-
- if (this._payloadLength === 126) this._state = GET_PAYLOAD_LENGTH_16;
- else if (this._payloadLength === 127) this._state = GET_PAYLOAD_LENGTH_64;
- else return this.haveLength();
- }
-
- /**
- * Gets extended payload length (7+16).
- *
- * @return {(RangeError|undefined)} A possible error
- * @private
- */
- getPayloadLength16 () {
- if (this._bufferedBytes < 2) {
- this._loop = false;
- return;
- }
-
- this._payloadLength = this.consume(2).readUInt16BE(0);
- return this.haveLength();
- }
-
- /**
- * Gets extended payload length (7+64).
- *
- * @return {(RangeError|undefined)} A possible error
- * @private
- */
- getPayloadLength64 () {
- if (this._bufferedBytes < 8) {
- this._loop = false;
- return;
- }
-
- const buf = this.consume(8);
- const num = buf.readUInt32BE(0);
-
- //
- // The maximum safe integer in JavaScript is 2^53 - 1. An error is returned
- // if payload length is greater than this number.
- //
- if (num > Math.pow(2, 53 - 32) - 1) {
- this._loop = false;
- return error(
- RangeError,
- 'Unsupported WebSocket frame: payload length > 2^53 - 1',
- false,
- 1009
- );
- }
-
- this._payloadLength = num * Math.pow(2, 32) + buf.readUInt32BE(4);
- return this.haveLength();
- }
-
- /**
- * Payload length has been read.
- *
- * @return {(RangeError|undefined)} A possible error
- * @private
- */
- haveLength () {
- if (this._payloadLength && this._opcode < 0x08) {
- this._totalPayloadLength += this._payloadLength;
- if (this._totalPayloadLength > this._maxPayload && this._maxPayload > 0) {
- this._loop = false;
- return error(RangeError, 'Max payload size exceeded', false, 1009);
- }
- }
-
- if (this._masked) this._state = GET_MASK;
- else this._state = GET_DATA;
- }
-
- /**
- * Reads mask bytes.
- *
- * @private
- */
- getMask () {
- if (this._bufferedBytes < 4) {
- this._loop = false;
- return;
- }
-
- this._mask = this.consume(4);
- this._state = GET_DATA;
- }
-
- /**
- * Reads data bytes.
- *
- * @param {Function} cb Callback
- * @return {(Error|RangeError|undefined)} A possible error
- * @private
- */
- getData (cb) {
- var data = constants.EMPTY_BUFFER;
-
- if (this._payloadLength) {
- if (this._bufferedBytes < this._payloadLength) {
- this._loop = false;
- return;
- }
-
- data = this.consume(this._payloadLength);
- if (this._masked) bufferUtil.unmask(data, this._mask);
- }
-
- if (this._opcode > 0x07) return this.controlMessage(data);
-
- if (this._compressed) {
- this._state = INFLATING;
- this.decompress(data, cb);
- return;
- }
-
- if (data.length) {
- //
- // This message is not compressed so its lenght is the sum of the payload
- // length of all fragments.
- //
- this._messageLength = this._totalPayloadLength;
- this._fragments.push(data);
- }
-
- return this.dataMessage();
- }
-
- /**
- * Decompresses data.
- *
- * @param {Buffer} data Compressed data
- * @param {Function} cb Callback
- * @private
- */
- decompress (data, cb) {
- const perMessageDeflate = this._extensions[PerMessageDeflate.extensionName];
-
- perMessageDeflate.decompress(data, this._fin, (err, buf) => {
- if (err) return cb(err);
-
- if (buf.length) {
- this._messageLength += buf.length;
- if (this._messageLength > this._maxPayload && this._maxPayload > 0) {
- return cb(error(RangeError, 'Max payload size exceeded', false, 1009));
- }
-
- this._fragments.push(buf);
- }
-
- const er = this.dataMessage();
- if (er) return cb(er);
-
- this.startLoop(cb);
- });
- }
-
- /**
- * Handles a data message.
- *
- * @return {(Error|undefined)} A possible error
- * @private
- */
- dataMessage () {
- if (this._fin) {
- const messageLength = this._messageLength;
- const fragments = this._fragments;
-
- this._totalPayloadLength = 0;
- this._messageLength = 0;
- this._fragmented = 0;
- this._fragments = [];
-
- if (this._opcode === 2) {
- var data;
-
- if (this._binaryType === 'nodebuffer') {
- data = toBuffer(fragments, messageLength);
- } else if (this._binaryType === 'arraybuffer') {
- data = toArrayBuffer(toBuffer(fragments, messageLength));
- } else {
- data = fragments;
- }
-
- this.emit('message', data);
- } else {
- const buf = toBuffer(fragments, messageLength);
-
- if (!validation.isValidUTF8(buf)) {
- this._loop = false;
- return error(Error, 'invalid UTF-8 sequence', true, 1007);
- }
-
- this.emit('message', buf.toString());
- }
- }
-
- this._state = GET_INFO;
- }
-
- /**
- * Handles a control message.
- *
- * @param {Buffer} data Data to handle
- * @return {(Error|RangeError|undefined)} A possible error
- * @private
- */
- controlMessage (data) {
- if (this._opcode === 0x08) {
- this._loop = false;
-
- if (data.length === 0) {
- this.emit('conclude', 1005, '');
- this.end();
- } else if (data.length === 1) {
- return error(RangeError, 'invalid payload length 1', true, 1002);
- } else {
- const code = data.readUInt16BE(0);
-
- if (!validation.isValidStatusCode(code)) {
- return error(RangeError, `invalid status code ${code}`, true, 1002);
- }
-
- const buf = data.slice(2);
-
- if (!validation.isValidUTF8(buf)) {
- return error(Error, 'invalid UTF-8 sequence', true, 1007);
- }
-
- this.emit('conclude', code, buf.toString());
- this.end();
- }
-
- return;
- }
-
- if (this._opcode === 0x09) this.emit('ping', data);
- else this.emit('pong', data);
-
- this._state = GET_INFO;
- }
-}
-
-module.exports = Receiver;
-
-/**
- * Builds an error object.
- *
- * @param {(Error|RangeError)} ErrorCtor The error constructor
- * @param {String} message The error message
- * @param {Boolean} prefix Specifies whether or not to add a default prefix to
- * `message`
- * @param {Number} statusCode The status code
- * @return {(Error|RangeError)} The error
- * @private
- */
-function error (ErrorCtor, message, prefix, statusCode) {
- const err = new ErrorCtor(
- prefix ? `Invalid WebSocket frame: ${message}` : message
- );
-
- Error.captureStackTrace(err, error);
- err[constants.kStatusCode] = statusCode;
- return err;
-}
-
-/**
- * Makes a buffer from a list of fragments.
- *
- * @param {Buffer[]} fragments The list of fragments composing the message
- * @param {Number} messageLength The length of the message
- * @return {Buffer}
- * @private
- */
-function toBuffer (fragments, messageLength) {
- if (fragments.length === 1) return fragments[0];
- if (fragments.length > 1) return bufferUtil.concat(fragments, messageLength);
- return constants.EMPTY_BUFFER;
-}
-
-/**
- * Converts a buffer to an `ArrayBuffer`.
- *
- * @param {Buffer} The buffer to convert
- * @return {ArrayBuffer} Converted buffer
- */
-function toArrayBuffer (buf) {
- if (buf.byteOffset === 0 && buf.byteLength === buf.buffer.byteLength) {
- return buf.buffer;
- }
-
- return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
-}
projects / VSoRC / .git / blobdiff