feat: add support for multiple server IPs

src/models/server.ts

@@ -1,10 +1,11 @@
 import { Schema, model } from 'mongoose';
 import uniqueValidator from 'mongoose-unique-validator';
-import type { IServer, IServerMethods, ServerModel } from '@/types/mongoose/server';
+import type { IServer, IServerConnectInfo, IServerMethods, ServerModel } from '@/types/mongoose/server';
 
 const ServerSchema = new Schema<IServer, ServerModel, IServerMethods>({
 	client_id: String,
 	ip: String,
+	ipList: [String], // If specified, clients will be given a random IP from this list
 	port: Number,
 	service_name: String,
 	service_type: String,
@@ -18,4 +19,17 @@ const ServerSchema = new Schema<IServer, ServerModel, IServerMethods>({
 
 ServerSchema.plugin(uniqueValidator, { message: '{PATH} already in use.' });
 
+ServerSchema.method('getServerConnectInfo', async function (): Promise<IServerConnectInfo> {
+	const ipList = (this.ipList ?? [this.ip]).filter((v): v is string => !!v);
+	if (ipList.length === 0) {
+		throw new Error(`No IP configured for server ${this._id}`);
+	}
+
+	const randomIp = ipList[Math.floor(Math.random() * ipList.length)];
+	return {
+		ip: randomIp,
+		port: this.port
+	};
+});
+
 export const Server = model<IServer, ServerModel>('Server', ServerSchema);

src/provisioning.ts

@@ -13,7 +13,8 @@ const serverProvisioningSchema = z.object({
 	servers: z.array(z.object({
 		id: z.string(),
 		name: z.string(),
-		ip: z.string(),
+		ip: z.string().optional(),
+		ipList: z.array(z.string()).optional(),
 		port: z.coerce.number()
 	}))
 });
@@ -40,6 +41,7 @@ export async function handleServerProvisioning(): Promise<void> {
 			$set: {
 				_id: id,
 				service_name: server.name,
+				ipList: server.ipList,
 				ip: server.ip,
 				port: server.port
 			}

src/services/nasc/routes/ac.ts

@@ -51,7 +51,8 @@ router.post('/', async (request: express.Request, response: express.Response): P
 		return;
 	}
 
-	if (action === 'LOGIN' && server.port <= 0 && server.ip !== '0.0.0.0') {
+	const connectInfo = await server.getServerConnectInfo();
+	if (action === 'LOGIN' && connectInfo.port <= 0 && connectInfo.ip !== '0.0.0.0') {
 		// * Addresses of 0.0.0.0:0 are allowed
 		// * They are expected for titles with no NEX server
 		response.status(200).send(nascError('110').toString());
@@ -85,8 +86,9 @@ async function processLoginRequest(server: HydratedServerDocument, pid: number,
 	const nexTokenBuffer = await generateToken(server.aes_key, tokenOptions);
 	const nexToken = nintendoBase64Encode(nexTokenBuffer || '');
 
+	const connectInfo = await server.getServerConnectInfo();
 	return new URLSearchParams({
-		locator: nintendoBase64Encode(`${server.ip}:${server.port}`),
+		locator: nintendoBase64Encode(`${connectInfo.ip}:${connectInfo.port}`),
 		retry: nintendoBase64Encode('0'),
 		returncd: nintendoBase64Encode('001'),
 		token: nexToken,

src/services/nnas/routes/provider.ts

@@ -229,12 +229,13 @@ router.get('/nex_token/@me', async (request: express.Request, response: express.
 		nexToken = Buffer.from(nexToken || '', 'base64').toString('hex');
 	}
 
+	const connectInfo = await server.getServerConnectInfo();
 	response.send(xmlbuilder.create({
 		nex_token: {
-			host: server.ip,
+			host: connectInfo.ip,
 			nex_password: nexAccount.password,
 			pid: nexAccount.pid,
-			port: server.port,
+			port: connectInfo.port,
 			token: nexToken
 		}
 	}).end());

src/types/mongoose/server.ts

@@ -2,7 +2,8 @@ import type { Model, HydratedDocument } from 'mongoose';
 
 export interface IServer {
 	client_id: string;
-	ip: string;
+	ip?: string;
+	ipList?: string[];
 	port: number;
 	service_name: string;
 	service_type: string;
@@ -14,7 +15,14 @@ export interface IServer {
 	aes_key: string;
 }
 
-export interface IServerMethods {}
+export interface IServerConnectInfo {
+	ip: string;
+	port: number;
+}
+
+export interface IServerMethods {
+	getServerConnectInfo(): Promise<IServerConnectInfo>;
+}
 
 interface IServerQueryHelpers {}