src/charging-station/ui-server/UIWebSocketServer.ts

   1 import type { IncomingMessage } from 'http';
   2 import type internal from 'stream';
   3
   4 import { StatusCodes } from 'http-status-codes';
   5 import * as uuid from 'uuid';
   6 import WebSocket, { RawData, WebSocketServer } from 'ws';
   7
   8 import type { UIServerConfiguration } from '../../types/ConfigurationData';
   9 import type { ProtocolRequest, ProtocolResponse } from '../../types/UIProtocol';
  10 import { WebSocketCloseEventStatusCode } from '../../types/WebSocket';
  11 import logger from '../../utils/Logger';
  12 import Utils from '../../utils/Utils';
  13 import { AbstractUIServer } from './AbstractUIServer';
  14 import { UIServiceUtils } from './ui-services/UIServiceUtils';
  15
  16 const moduleName = 'UIWebSocketServer';
  17
  18 export default class UIWebSocketServer extends AbstractUIServer {
  19   private readonly webSocketServer: WebSocketServer;
  20
  21   public constructor(protected readonly uiServerConfiguration: UIServerConfiguration) {
  22     super(uiServerConfiguration);
  23     this.webSocketServer = new WebSocketServer({
  24       handleProtocols: UIServiceUtils.handleProtocols,
  25       noServer: true,
  26     });
  27   }
  28
  29   public start(): void {
  30     this.webSocketServer.on('connection', (ws: WebSocket, req: IncomingMessage): void => {
  31       const [protocol, version] = UIServiceUtils.getProtocolAndVersion(ws.protocol);
  32       if (UIServiceUtils.isProtocolAndVersionSupported(protocol, version) === false) {
  33         logger.error(
  34           `${this.logPrefix(
  35             moduleName,
  36             'start.server.onconnection'
  37           )} Unsupported UI protocol version: '${protocol}${version}'`
  38         );
  39         ws.close(WebSocketCloseEventStatusCode.CLOSE_PROTOCOL_ERROR);
  40       }
  41       this.sockets.add(ws);
  42       this.registerProtocolVersionUIService(version);
  43       ws.on('message', (rawData) => {
  44         const request = this.validateRawDataRequest(rawData);
  45         if (request === false) {
  46           ws.close(WebSocketCloseEventStatusCode.CLOSE_INVALID_PAYLOAD);
  47           return;
  48         }
  49         const [messageId, procedureName, payload] = request as ProtocolRequest;
  50         this.uiServices
  51           .get(version)
  52           .requestHandler(this.buildProtocolRequest(messageId, procedureName, payload))
  53           .catch(() => {
  54             /* Error caught by AbstractUIService */
  55           });
  56       });
  57       ws.on('error', (error) => {
  58         logger.error(`${this.logPrefix(moduleName, 'start.ws.onerror')} WebSocket error:`, error);
  59       });
  60       ws.on('close', (code, reason) => {
  61         this.sockets.delete(ws);
  62         logger.debug(
  63           `${this.logPrefix(
  64             moduleName,
  65             'start.ws.onclose'
  66           )} WebSocket closed: '${Utils.getWebSocketCloseEventStatusString(
  67             code
  68           )}' - '${reason.toString()}'`
  69         );
  70       });
  71     });
  72     this.httpServer.on(
  73       'upgrade',
  74       (req: IncomingMessage, socket: internal.Duplex, head: Buffer): void => {
  75         this.authenticate(req, (err) => {
  76           if (err) {
  77             socket.write(`HTTP/1.1 ${StatusCodes.UNAUTHORIZED} Unauthorized\r\n\r\n`);
  78             socket.destroy();
  79             return;
  80           }
  81           this.webSocketServer.handleUpgrade(req, socket, head, (ws: WebSocket) => {
  82             this.webSocketServer.emit('connection', ws, req);
  83           });
  84         });
  85       }
  86     );
  87     if (this.httpServer.listening === false) {
  88       this.httpServer.listen(this.uiServerConfiguration.options);
  89     }
  90   }
  91
  92   public sendRequest(request: ProtocolRequest): void {
  93     this.broadcastToClients(JSON.stringify(request));
  94   }
  95
  96   public sendResponse(response: ProtocolResponse): void {
  97     // TODO: send response only to the client that sent the request
  98     this.broadcastToClients(JSON.stringify(response));
  99   }
 100
 101   public logPrefix(modName?: string, methodName?: string, prefixSuffix?: string): string {
 102     const logMsgPrefix = prefixSuffix
 103       ? `UI WebSocket Server ${prefixSuffix}`
 104       : 'UI WebSocket Server';
 105     const logMsg =
 106       modName && methodName ? ` ${logMsgPrefix} | ${modName}.${methodName}:` : ` ${logMsgPrefix} |`;
 107     return Utils.logPrefix(logMsg);
 108   }
 109
 110   private broadcastToClients(message: string): void {
 111     for (const client of this.webSocketServer.clients) {
 112       if (client?.readyState === WebSocket.OPEN) {
 113         client.send(message);
 114       }
 115     }
 116   }
 117
 118   private authenticate(req: IncomingMessage, next: (err?: Error) => void): void {
 119     if (this.isBasicAuthEnabled() === true) {
 120       if (this.isValidBasicAuth(req) === false) {
 121         next(new Error('Unauthorized'));
 122       } else {
 123         next();
 124       }
 125     } else {
 126       next();
 127     }
 128   }
 129
 130   private validateRawDataRequest(rawData: RawData): ProtocolRequest | false {
 131     // logger.debug(
 132     //   `${this.logPrefix(
 133     //     moduleName,
 134     //     'validateRawDataRequest'
 135     //   )} Raw data received in string format: ${rawData.toString()}`
 136     // );
 137
 138     const request = JSON.parse(rawData.toString()) as ProtocolRequest;
 139
 140     if (Array.isArray(request) === false) {
 141       logger.error(
 142         `${this.logPrefix(
 143           moduleName,
 144           'validateRawDataRequest'
 145         )} UI protocol request is not an array:`,
 146         request
 147       );
 148       return false;
 149     }
 150
 151     if (request.length !== 3) {
 152       logger.error(
 153         `${this.logPrefix(moduleName, 'validateRawDataRequest')} UI protocol request is malformed:`,
 154         request
 155       );
 156       return false;
 157     }
 158
 159     if (uuid.validate(request[0]) === false) {
 160       logger.error(
 161         `${this.logPrefix(
 162           moduleName,
 163           'validateRawDataRequest'
 164         )} UI protocol request UUID field is invalid:`,
 165         request
 166       );
 167       return false;
 168     }
 169
 170     return request;
 171   }
 172 }