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Attach error codes to all receiver errors
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This change also moves message data and close codes into constants,
rather than repeating it at each point where the error is thrown.
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@pimterry
pimterry committed Jun 14, 2021
1 parent 074e6a8 commit 22d719f
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Showing 6 changed files with 77 additions and 34 deletions.
15 changes: 14 additions & 1 deletion lib/constants.js
View file
Expand Up @@ -6,5 +6,18 @@ module.exports = {
kStatusCode: Symbol('status-code'),
kWebSocket: Symbol('websocket'),
EMPTY_BUFFER: Buffer.alloc(0),
NOOP: () => {}
NOOP: () => {},
ERRORS: {
'WS_INVALID_OPCODE': { closeCode: 1002, message: "invalid opcode" },
'WS_INVALID_CLOSE_CODE': { closeCode: 1002, message: "invalid status code" },
'WS_UNEXPECTED_RSV_1': { closeCode: 1002, message: "RSV1 must be clear" },
'WS_UNEXPECTED_RSV_2_3': { closeCode: 1002, message: "RSV2 and RSV3 must be clear" },
'WS_EXPECTED_FIN': { closeCode: 1002, message: "FIN must be set" },
'WS_EXPECTED_MASK': { closeCode: 1002, message: "MASK must be set" },
'WS_UNEXPECTED_MASK': { closeCode: 1002, message: "MASK must be clear" },
'WS_INVALID_CONTROL_PAYLOAD_LENGTH': { closeCode: 1002, message: "invalid payload length" },

'WS_INVALID_UTF8': { closeCode: 1007, message: "invalid UTF-8 sequence" },
'WS_INVALID_DATA_PAYLOAD_LENGTH': { closeCode: 1009, message: "Max payload size exceeded" }
}
};
8 changes: 5 additions & 3 deletions lib/permessage-deflate.js
View file
Expand Up @@ -4,7 +4,7 @@ const zlib = require('zlib');

const bufferUtil = require('./buffer-util');
const Limiter = require('./limiter');
const { kStatusCode, NOOP } = require('./constants');
const { kStatusCode, NOOP, ERRORS } = require('./constants');

const TRAILER = Buffer.from([0x00, 0x00, 0xff, 0xff]);
const kPerMessageDeflate = Symbol('permessage-deflate');
Expand Down Expand Up @@ -494,8 +494,10 @@ function inflateOnData(chunk) {
return;
}

this[kError] = new RangeError('Max payload size exceeded');
this[kError][kStatusCode] = 1009;
const code = 'WS_INVALID_DATA_PAYLOAD_LENGTH';
this[kError] = new RangeError(ERRORS[code].message);
this[kError].code = code;
this[kError][kStatusCode] = ERRORS[code].closeCode;
this.removeListener('data', inflateOnData);
this.reset();
}
Expand Down
64 changes: 34 additions & 30 deletions lib/receiver.js
View file
Expand Up @@ -7,7 +7,8 @@ const {
BINARY_TYPES,
EMPTY_BUFFER,
kStatusCode,
kWebSocket
kWebSocket,
ERRORS
} = require('./constants');
const { concat, toArrayBuffer, unmask } = require('./buffer-util');
const { isValidStatusCode, isValidUTF8 } = require('./validation');
Expand Down Expand Up @@ -168,14 +169,14 @@ class Receiver extends Writable {

if ((buf[0] & 0x30) !== 0x00) {
this._loop = false;
return error(RangeError, 'RSV2 and RSV3 must be clear', true, 1002);
return error(RangeError, 'WS_UNEXPECTED_RSV_2_3');
}

const compressed = (buf[0] & 0x40) === 0x40;

if (compressed && !this._extensions[PerMessageDeflate.extensionName]) {
this._loop = false;
return error(RangeError, 'RSV1 must be clear', true, 1002);
return error(RangeError, 'WS_UNEXPECTED_RSV_1');
}

this._fin = (buf[0] & 0x80) === 0x80;
Expand All @@ -185,45 +186,44 @@ class Receiver extends Writable {
if (this._opcode === 0x00) {
if (compressed) {
this._loop = false;
return error(RangeError, 'RSV1 must be clear', true, 1002);
return error(RangeError, 'WS_UNEXPECTED_RSV_1');
}

if (!this._fragmented) {
this._loop = false;
return error(RangeError, 'invalid opcode 0', true, 1002);
return error(RangeError, 'WS_INVALID_OPCODE', 'invalid opcode 0');
}

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);
return error(RangeError, 'WS_INVALID_OPCODE', `invalid opcode ${this._opcode}`);
}

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);
return error(RangeError, 'WS_EXPECTED_FIN');
}

if (compressed) {
this._loop = false;
return error(RangeError, 'RSV1 must be clear', true, 1002);
return error(RangeError, 'WS_UNEXPECTED_RSV_1');
}

if (this._payloadLength > 0x7d) {
this._loop = false;
return error(
RangeError,
`invalid payload length ${this._payloadLength}`,
true,
1002
'WS_INVALID_CONTROL_PAYLOAD_LENGTH',
`invalid payload length ${this._payloadLength}`
);
}
} else {
this._loop = false;
return error(RangeError, `invalid opcode ${this._opcode}`, true, 1002);
return error(RangeError, 'WS_INVALID_OPCODE', `invalid opcode ${this._opcode}`);
}

if (!this._fin && !this._fragmented) this._fragmented = this._opcode;
Expand All @@ -232,11 +232,11 @@ class Receiver extends Writable {
if (this._isServer) {
if (!this._masked) {
this._loop = false;
return error(RangeError, 'MASK must be set', true, 1002);
return error(RangeError, 'WS_EXPECTED_MASK');
}
} else if (this._masked) {
this._loop = false;
return error(RangeError, 'MASK must be clear', true, 1002);
return error(RangeError, 'WS_UNEXPECTED_MASK');
}

if (this._payloadLength === 126) this._state = GET_PAYLOAD_LENGTH_16;
Expand Down Expand Up @@ -283,9 +283,8 @@ class Receiver extends Writable {
this._loop = false;
return error(
RangeError,
'Unsupported WebSocket frame: payload length > 2^53 - 1',
false,
1009
'WS_INVALID_DATA_PAYLOAD_LENGTH',
'Unsupported WebSocket frame: payload length > 2^53 - 1'
);
}

Expand All @@ -304,7 +303,7 @@ class Receiver extends Writable {
this._totalPayloadLength += this._payloadLength;
if (this._totalPayloadLength > this._maxPayload && this._maxPayload > 0) {
this._loop = false;
return error(RangeError, 'Max payload size exceeded', false, 1009);
return error(RangeError, 'WS_INVALID_DATA_PAYLOAD_LENGTH');
}
}

Expand Down Expand Up @@ -384,7 +383,7 @@ class Receiver extends Writable {
this._messageLength += buf.length;
if (this._messageLength > this._maxPayload && this._maxPayload > 0) {
return cb(
error(RangeError, 'Max payload size exceeded', false, 1009)
error(RangeError, 'WS_INVALID_DATA_PAYLOAD_LENGTH')
);
}

Expand Down Expand Up @@ -431,7 +430,7 @@ class Receiver extends Writable {

if (!isValidUTF8(buf)) {
this._loop = false;
return error(Error, 'invalid UTF-8 sequence', true, 1007);
return error(Error, 'WS_INVALID_UTF8');
}

this.emit('message', buf.toString());
Expand All @@ -456,18 +455,18 @@ class Receiver extends Writable {
this.emit('conclude', 1005, '');
this.end();
} else if (data.length === 1) {
return error(RangeError, 'invalid payload length 1', true, 1002);
return error(RangeError, 'WS_INVALID_CONTROL_PAYLOAD_LENGTH', 'invalid payload length 1');
} else {
const code = data.readUInt16BE(0);

if (!isValidStatusCode(code)) {
return error(RangeError, `invalid status code ${code}`, true, 1002);
return error(RangeError, 'WS_INVALID_CLOSE_CODE', `invalid status code ${code}`);
}

const buf = data.slice(2);

if (!isValidUTF8(buf)) {
return error(Error, 'invalid UTF-8 sequence', true, 1007);
return error(Error, 'WS_INVALID_UTF8');
}

this.emit('conclude', code, buf.toString());
Expand All @@ -489,19 +488,24 @@ 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
* @param {String} errorCode The exposed error code (must be a key of ERRORS constant)
* @param {String} message An optional error message, overriding the default for the code
* @return {(Error|RangeError)} The error
* @private
*/
function error(ErrorCtor, message, prefix, statusCode) {
function error(ErrorCtor, errorCode, customMessage) {
const errorDefinition = ERRORS[errorCode];

const shouldPrefix = errorDefinition.closeCode !== 1009; // Long payloads aren't technically 'invalid frames'

const message = customMessage || errorDefinition.message;

const err = new ErrorCtor(
prefix ? `Invalid WebSocket frame: ${message}` : message
shouldPrefix ? `Invalid WebSocket frame: ${message}` : message
);

Error.captureStackTrace(err, error);
err[kStatusCode] = statusCode;
err.code = errorCode;
err[kStatusCode] = errorDefinition.closeCode;
return err;
}
1 change: 1 addition & 0 deletions test/create-websocket-stream.test.js
View file
Expand Up @@ -210,6 +210,7 @@ describe('createWebSocketStream', () => {

duplex.on('error', (err) => {
assert.ok(err instanceof RangeError);
assert.strictEqual(err.code, 'WS_INVALID_OPCODE');
assert.strictEqual(
err.message,
'Invalid WebSocket frame: invalid opcode 5'
Expand Down

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