diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/websocket/connection.js | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/lib/websocket/connection.js b/lib/websocket/connection.js new file mode 100644 index 0000000..e0fa697 --- /dev/null +++ b/lib/websocket/connection.js @@ -0,0 +1,291 @@ +'use strict' + +const diagnosticsChannel = require('diagnostics_channel') +const { uid, states } = require('./constants') +const { + kReadyState, + kSentClose, + kByteParser, + kReceivedClose +} = require('./symbols') +const { fireEvent, failWebsocketConnection } = require('./util') +const { CloseEvent } = require('./events') +const { makeRequest } = require('../fetch/request') +const { fetching } = require('../fetch/index') +const { Headers } = require('../fetch/headers') +const { getGlobalDispatcher } = require('../global') +const { kHeadersList } = require('../core/symbols') + +const channels = {} +channels.open = diagnosticsChannel.channel('undici:websocket:open') +channels.close = diagnosticsChannel.channel('undici:websocket:close') +channels.socketError = diagnosticsChannel.channel('undici:websocket:socket_error') + +/** @type {import('crypto')} */ +let crypto +try { + crypto = require('crypto') +} catch { + +} + +/** + * @see https://websockets.spec.whatwg.org/#concept-websocket-establish + * @param {URL} url + * @param {string|string[]} protocols + * @param {import('./websocket').WebSocket} ws + * @param {(response: any) => void} onEstablish + * @param {Partial<import('../../types/websocket').WebSocketInit>} options + */ +function establishWebSocketConnection (url, protocols, ws, onEstablish, options) { + // 1. Let requestURL be a copy of url, with its scheme set to "http", if url’s + // scheme is "ws", and to "https" otherwise. + const requestURL = url + + requestURL.protocol = url.protocol === 'ws:' ? 'http:' : 'https:' + + // 2. Let request be a new request, whose URL is requestURL, client is client, + // service-workers mode is "none", referrer is "no-referrer", mode is + // "websocket", credentials mode is "include", cache mode is "no-store" , + // and redirect mode is "error". + const request = makeRequest({ + urlList: [requestURL], + serviceWorkers: 'none', + referrer: 'no-referrer', + mode: 'websocket', + credentials: 'include', + cache: 'no-store', + redirect: 'error' + }) + + // Note: undici extension, allow setting custom headers. + if (options.headers) { + const headersList = new Headers(options.headers)[kHeadersList] + + request.headersList = headersList + } + + // 3. Append (`Upgrade`, `websocket`) to request’s header list. + // 4. Append (`Connection`, `Upgrade`) to request’s header list. + // Note: both of these are handled by undici currently. + // https://github.com/nodejs/undici/blob/68c269c4144c446f3f1220951338daef4a6b5ec4/lib/client.js#L1397 + + // 5. Let keyValue be a nonce consisting of a randomly selected + // 16-byte value that has been forgiving-base64-encoded and + // isomorphic encoded. + const keyValue = crypto.randomBytes(16).toString('base64') + + // 6. Append (`Sec-WebSocket-Key`, keyValue) to request’s + // header list. + request.headersList.append('sec-websocket-key', keyValue) + + // 7. Append (`Sec-WebSocket-Version`, `13`) to request’s + // header list. + request.headersList.append('sec-websocket-version', '13') + + // 8. For each protocol in protocols, combine + // (`Sec-WebSocket-Protocol`, protocol) in request’s header + // list. + for (const protocol of protocols) { + request.headersList.append('sec-websocket-protocol', protocol) + } + + // 9. Let permessageDeflate be a user-agent defined + // "permessage-deflate" extension header value. + // https://github.com/mozilla/gecko-dev/blob/ce78234f5e653a5d3916813ff990f053510227bc/netwerk/protocol/websocket/WebSocketChannel.cpp#L2673 + // TODO: enable once permessage-deflate is supported + const permessageDeflate = '' // 'permessage-deflate; 15' + + // 10. Append (`Sec-WebSocket-Extensions`, permessageDeflate) to + // request’s header list. + // request.headersList.append('sec-websocket-extensions', permessageDeflate) + + // 11. Fetch request with useParallelQueue set to true, and + // processResponse given response being these steps: + const controller = fetching({ + request, + useParallelQueue: true, + dispatcher: options.dispatcher ?? getGlobalDispatcher(), + processResponse (response) { + // 1. If response is a network error or its status is not 101, + // fail the WebSocket connection. + if (response.type === 'error' || response.status !== 101) { + failWebsocketConnection(ws, 'Received network error or non-101 status code.') + return + } + + // 2. If protocols is not the empty list and extracting header + // list values given `Sec-WebSocket-Protocol` and response’s + // header list results in null, failure, or the empty byte + // sequence, then fail the WebSocket connection. + if (protocols.length !== 0 && !response.headersList.get('Sec-WebSocket-Protocol')) { + failWebsocketConnection(ws, 'Server did not respond with sent protocols.') + return + } + + // 3. Follow the requirements stated step 2 to step 6, inclusive, + // of the last set of steps in section 4.1 of The WebSocket + // Protocol to validate response. This either results in fail + // the WebSocket connection or the WebSocket connection is + // established. + + // 2. If the response lacks an |Upgrade| header field or the |Upgrade| + // header field contains a value that is not an ASCII case- + // insensitive match for the value "websocket", the client MUST + // _Fail the WebSocket Connection_. + if (response.headersList.get('Upgrade')?.toLowerCase() !== 'websocket') { + failWebsocketConnection(ws, 'Server did not set Upgrade header to "websocket".') + return + } + + // 3. If the response lacks a |Connection| header field or the + // |Connection| header field doesn't contain a token that is an + // ASCII case-insensitive match for the value "Upgrade", the client + // MUST _Fail the WebSocket Connection_. + if (response.headersList.get('Connection')?.toLowerCase() !== 'upgrade') { + failWebsocketConnection(ws, 'Server did not set Connection header to "upgrade".') + return + } + + // 4. If the response lacks a |Sec-WebSocket-Accept| header field or + // the |Sec-WebSocket-Accept| contains a value other than the + // base64-encoded SHA-1 of the concatenation of the |Sec-WebSocket- + // Key| (as a string, not base64-decoded) with the string "258EAFA5- + // E914-47DA-95CA-C5AB0DC85B11" but ignoring any leading and + // trailing whitespace, the client MUST _Fail the WebSocket + // Connection_. + const secWSAccept = response.headersList.get('Sec-WebSocket-Accept') + const digest = crypto.createHash('sha1').update(keyValue + uid).digest('base64') + if (secWSAccept !== digest) { + failWebsocketConnection(ws, 'Incorrect hash received in Sec-WebSocket-Accept header.') + return + } + + // 5. If the response includes a |Sec-WebSocket-Extensions| header + // field and this header field indicates the use of an extension + // that was not present in the client's handshake (the server has + // indicated an extension not requested by the client), the client + // MUST _Fail the WebSocket Connection_. (The parsing of this + // header field to determine which extensions are requested is + // discussed in Section 9.1.) + const secExtension = response.headersList.get('Sec-WebSocket-Extensions') + + if (secExtension !== null && secExtension !== permessageDeflate) { + failWebsocketConnection(ws, 'Received different permessage-deflate than the one set.') + return + } + + // 6. If the response includes a |Sec-WebSocket-Protocol| header field + // and this header field indicates the use of a subprotocol that was + // not present in the client's handshake (the server has indicated a + // subprotocol not requested by the client), the client MUST _Fail + // the WebSocket Connection_. + const secProtocol = response.headersList.get('Sec-WebSocket-Protocol') + + if (secProtocol !== null && secProtocol !== request.headersList.get('Sec-WebSocket-Protocol')) { + failWebsocketConnection(ws, 'Protocol was not set in the opening handshake.') + return + } + + response.socket.on('data', onSocketData) + response.socket.on('close', onSocketClose) + response.socket.on('error', onSocketError) + + if (channels.open.hasSubscribers) { + channels.open.publish({ + address: response.socket.address(), + protocol: secProtocol, + extensions: secExtension + }) + } + + onEstablish(response) + } + }) + + return controller +} + +/** + * @param {Buffer} chunk + */ +function onSocketData (chunk) { + if (!this.ws[kByteParser].write(chunk)) { + this.pause() + } +} + +/** + * @see https://websockets.spec.whatwg.org/#feedback-from-the-protocol + * @see https://datatracker.ietf.org/doc/html/rfc6455#section-7.1.4 + */ +function onSocketClose () { + const { ws } = this + + // If the TCP connection was closed after the + // WebSocket closing handshake was completed, the WebSocket connection + // is said to have been closed _cleanly_. + const wasClean = ws[kSentClose] && ws[kReceivedClose] + + let code = 1005 + let reason = '' + + const result = ws[kByteParser].closingInfo + + if (result) { + code = result.code ?? 1005 + reason = result.reason + } else if (!ws[kSentClose]) { + // If _The WebSocket + // Connection is Closed_ and no Close control frame was received by the + // endpoint (such as could occur if the underlying transport connection + // is lost), _The WebSocket Connection Close Code_ is considered to be + // 1006. + code = 1006 + } + + // 1. Change the ready state to CLOSED (3). + ws[kReadyState] = states.CLOSED + + // 2. If the user agent was required to fail the WebSocket + // connection, or if the WebSocket connection was closed + // after being flagged as full, fire an event named error + // at the WebSocket object. + // TODO + + // 3. Fire an event named close at the WebSocket object, + // using CloseEvent, with the wasClean attribute + // initialized to true if the connection closed cleanly + // and false otherwise, the code attribute initialized to + // the WebSocket connection close code, and the reason + // attribute initialized to the result of applying UTF-8 + // decode without BOM to the WebSocket connection close + // reason. + fireEvent('close', ws, CloseEvent, { + wasClean, code, reason + }) + + if (channels.close.hasSubscribers) { + channels.close.publish({ + websocket: ws, + code, + reason + }) + } +} + +function onSocketError (error) { + const { ws } = this + + ws[kReadyState] = states.CLOSING + + if (channels.socketError.hasSubscribers) { + channels.socketError.publish(error) + } + + this.destroy() +} + +module.exports = { + establishWebSocketConnection +} |