feat: send socket.io error only through middleware

src/lib/ws/gateway.ts

@@ -10,7 +10,6 @@ import { handleStatsReport } from '../../probe/handler/stats.js';
 import { scopedLogger } from '../logger.js';
 import { getWsServer, PROBES_NAMESPACE } from './server.js';
 import { probeMetadata } from './middleware/probe-metadata.js';
-import { verifyIpLimit } from './helper/probe-ip-limit.js';
 import { errorHandler } from './helper/error-handler.js';
 import { subscribeWithHandler } from './helper/subscribe-handler.js';
 
@@ -22,8 +21,6 @@ io
 	.of(PROBES_NAMESPACE)
 	.use(probeMetadata)
 	.on('connect', errorHandler(async (socket: Socket) => {
-		await verifyIpLimit(socket);
-
 		const probe = socket.data['probe'] as Probe;
 		socket.emit('api:connect:location', probe.location);
 		logger.info(`ws client ${socket.id} connected from ${probe.location.city}, ${probe.location.country} [${probe.ipAddress} - ${probe.location.network}]`);

src/lib/ws/helper/error-handler.ts

@@ -1,7 +1,6 @@
 import type { Socket } from 'socket.io';
 import getProbeIp from '../../get-probe-ip.js';
 import { scopedLogger } from '../../logger.js';
-import { WsError } from '../ws-error.js';
 
 const logger = scopedLogger('ws:error');
 
@@ -27,10 +26,6 @@ export const errorHandler = (next: NextArgument) => (socket: Socket, mwNext?: (e
 		logger.info(`disconnecting client ${socket.id} for (${reason}) [${clientIp}]`);
 		logger.debug(error);
 
-		if (error instanceof WsError) {
-			socket.emit('api:error', error.toJson());
-		}
-
 		if (mwNext) {
 			mwNext(error);
 		}

src/lib/ws/helper/probe-ip-limit.ts

@@ -1,32 +1,20 @@
 import * as process from 'node:process';
-import type { Socket } from 'socket.io';
-import type { Probe } from '../../../probe/types.js';
-import { WsError } from '../ws-error.js';
 import { fetchSockets } from '../server.js';
 import { scopedLogger } from '../../logger.js';
+import { InternalError } from '../../internal-error.js';
 
 const logger = scopedLogger('ws:limit');
 
-export const verifyIpLimit = async (socket: Socket): Promise<void> => {
+export const verifyIpLimit = async (ip: string, socketId: string): Promise<void> => {
 	if (process.env['FAKE_PROBE_IP']) {
 		return;
 	}
 
-	const probe = socket.data['probe'] as Probe;
-
 	const socketList = await fetchSockets();
-	const previousSocket = socketList.find(s => s.data.probe.ipAddress === probe.ipAddress && s.id !== socket.id);
+	const previousSocket = socketList.find(s => s.data.probe.ipAddress === ip && s.id !== socketId);
 
 	if (previousSocket) {
-		logger.info(`ws client ${socket.id} has reached the concurrent IP limit.`, { message: previousSocket.data.probe.ipAddress });
-		throw new WsError(
-			'IP Limit',
-			{
-				code: 'ip_limit',
-				socketId: socket.id,
-				probe,
-				ipAddress: probe.ipAddress,
-			},
-		);
+		logger.info(`ws client ${socketId} has reached the concurrent IP limit.`, { message: previousSocket.data.probe.ipAddress });
+		throw new InternalError('ip limit', true);
 	}
 };

src/lib/ws/middleware/probe-metadata.ts

@@ -24,7 +24,6 @@ export const probeMetadata = errorHandler(async (socket: Socket, next: (error?:
 		}
 
 		throw new WsError(message, {
-			socketId: socket.id,
 			ipAddress: clientIp ?? '',
 		});
 	}

src/lib/ws/ws-error.ts

@@ -1,31 +1,12 @@
-import type { Probe } from '../../probe/types.js';
-
-type Info = {
-	socketId: string;
+type Data = {
 	ipAddress: string;
-	// A string used for message parsing
-	code?: string;
-	probe?: Probe;
-	cause?: unknown;
-};
-
-type JsonResponse = {
-	message: string;
-	info: Info;
 };
 
 export class WsError extends Error {
-	info: Info;
-	constructor (message: string, info: Info) {
+	data: Data;
+	constructor (message: string, data: Data) {
 		super(message);
-		this.info = info;
-	}
-
-	toJson (): JsonResponse {
-		return {
-			message: this.message,
-			info: this.info,
-		};
+		this.data = data;
 	}
 }
 

src/probe/builder.ts

@@ -17,6 +17,7 @@ import { createGeoipClient } from '../lib/geoip/client.js';
 import getProbeIp from '../lib/get-probe-ip.js';
 import { getRegion } from '../lib/ip-ranges.js';
 import type { Probe, ProbeLocation, Tag } from './types.js';
+import { verifyIpLimit } from '../lib/ws/helper/probe-ip-limit.js';
 
 const fakeIpForDebug = () => {
 	return _.sample([
@@ -62,6 +63,8 @@ export const buildProbe = async (socket: Socket): Promise<Probe> => {
 		throw new Error(`couldn't detect probe location for ip ${clientIp}`);
 	}
 
+	await verifyIpLimit(clientIp, socket.id);
+
 	const location = getLocation(ipInfo);
 
 	const tags = getTags(clientIp);