Add support for TURN server and allow configurable STUN server

.vscode/settings.json

@@ -0,0 +1,5 @@
+{
+    "search.exclude": {
+        "**/node_modules": false
+    }
+}

src/renderer/Voice.tsx

@@ -30,6 +30,7 @@ import Grid from '@material-ui/core/Grid';
 import makeStyles from '@material-ui/core/styles/makeStyles';
 import SupportLink from './SupportLink';
 import Divider from '@material-ui/core/Divider';
+import { validateClientPeerConfig } from './validateClientPeerConfig';
 // @ts-ignore
 import reverbOgx from 'arraybuffer-loader!../../static/reverb.ogx';
 
@@ -79,6 +80,19 @@ interface SocketError {
 	message?: string;
 }
 
+interface ClientPeerConfig {
+	forceRelayOnly: boolean;
+	iceServers: RTCIceServer[];
+}
+
+const DEFAULT_ICE_CONFIG: RTCConfiguration = {
+	iceServers: [
+		{
+			urls: 'stun:stun.l.google.com:19302',
+		},
+	],
+};
+
 function calculateVoiceAudio(
 	state: AmongUsState,
 	settings: ISettings,
@@ -408,10 +422,44 @@ const Voice: React.FC<VoiceProps> = function ({
 		socket.on('connect', () => {
 			setConnected(true);
 		});
+
 		socket.on('disconnect', () => {
 			setConnected(false);
 		});
 
+		let iceConfig: RTCConfiguration = DEFAULT_ICE_CONFIG;
+		socket.on('clientPeerConfig', (clientPeerConfig: ClientPeerConfig) => {
+			if (!validateClientPeerConfig(clientPeerConfig)) {
+				let errorsFormatted = '';
+				if (validateClientPeerConfig.errors) {
+					errorsFormatted = validateClientPeerConfig.errors
+						.map((error) => error.dataPath + ' ' + error.message)
+						.join('\n');
+				}
+				alert(
+					`Server sent a malformed peer config. Default config will be used. See errors below:\n${errorsFormatted}`
+				);
+				return;
+			}
+
+			if (
+				clientPeerConfig.forceRelayOnly &&
+				!clientPeerConfig.iceServers.some((server) =>
+					server.urls.toString().includes('turn:')
+				)
+			) {
+				alert(
+					'Server has forced relay mode enabled but provides no relay servers. Default config will be used.'
+				);
+				return;
+			}
+
+			iceConfig = {
+				iceTransportPolicy: clientPeerConfig.forceRelayOnly ? 'relay' : 'all',
+				iceServers: clientPeerConfig.iceServers,
+			};
+		});
+
 		// Initialize variables
 		let audioListener: {
 			connect: () => void;
@@ -494,13 +542,7 @@ const Voice: React.FC<VoiceProps> = function ({
 					const connection = new Peer({
 						stream,
 						initiator,
-						config: {
-							iceServers: [
-								{
-									urls: 'stun:stun.l.google.com:19302',
-								},
-							],
-						},
+						config: iceConfig,
 					});
 					setPeerConnections((connections) => {
 						connections[peer] = connection;

src/renderer/validateClientPeerConfig.ts

@@ -0,0 +1,34 @@
+import Ajv from 'ajv';
+
+export const validateClientPeerConfig = new Ajv({ format: 'full', allErrors: true }).compile({
+	type: 'object',
+	properties: {
+		forceRelayOnly: {
+			type: 'boolean'
+		},
+		iceServers: {
+			type: 'array',
+			items: {
+				type: 'object',
+				properties: {
+					urls: {
+						type: ['string', 'array'],
+						format: 'uri',
+						items: {
+							type: 'string',
+							format: 'uri'
+						}
+					},
+					username: {
+						type: 'string',
+					},
+					credential: {
+						type: 'string',
+					}
+				},
+				required: ['urls']
+			}
+		}
+	},
+	required: ['forceRelayOnly', 'iceServers']
+});