Added HAProxy support

README.md

@@ -59,7 +59,8 @@ let result = await mc.lookup({
     timeout: 10000,
     throwOnParseError: true,
     SRVLookup: true,
-    JSONParse: true
+    JSONParse: true,
+    HAProxy: false
 })
 
 console.log(result);
@@ -89,6 +90,8 @@ console.log(result);
       > Whether to perform a SRV lookup on the provided hostname. Set to `true` in order to skip. Useful to disable when you're only looking up the basic DNS records and a server with a specific port.
     * <b>`JSONParse?:`</b> boolean <i>`default: true`</i>
       > Whether to parse the JSON `status` field. Useful to disable when you only need the raw plaintext response. If false, the `status` field will be null.
+    * <b>`HAProxy?:`</b> boolean <i>`default: false`</i>
+      > Whether to send a HAProxy protocol header to the server. Useful when the server is behind a HAProxy load balancer. If true, the `status` field will be null.
   * ServerStatus
     * <b>`latency?:`</b> number
       > The time it takes to receive back a response after sending a small payload to a server, in milliseconds. Will be null if the `ping` option is false.

src/index.ts

@@ -19,7 +19,8 @@ import { promises as dns } from "node:dns";
  *    protocolVersion: 767
  *    throwOnParseError: false,
  *    SRVLookup: true,
- *    JSONParse: true
+ *    JSONParse: true,
+ *    HAProxy: false
  * })
  * ```
  */
@@ -38,14 +39,23 @@ export async function lookup(options?: ServerStatusOptions): Promise<ServerStatu
         let throwOnParseError = options.throwOnParseError != null ? options.throwOnParseError : true;
         let SRVLookup = options.SRVLookup != null ? options.SRVLookup : true;
         let JSONParse = options.JSONParse != null ? options.JSONParse : true;
+        let HAProxy = options.HAProxy != null ? options.HAProxy : false;
         if (SRVLookup) ({ hostname, port } = await processSRV(hostname, port))
         // Default port of 25565, default timeout of 10 seconds.
         // Ping is sent by default. 
 
         let portal = net.createConnection({ port: port, host: hostname, lookup: customLookup }, async () => {
-            // Send first the handshake, and then the status request to the server.
-            let handshake = await packetGen.craftHandshake(hostname, port, protocolVersion);
+            // 1. Send HAProxy message if enabled
+            // 2. Send handshake
+            // 3. Send status request
+
+            if (HAProxy) {
+                // I don't know what other data I could send, so just send local IP and 0
+                let HAProxyMessage = packetGen.craftHAProxyMessagePacket("127.0.0.1", '127.0.0.1', 0, port);
+                portal.write(HAProxyMessage);
+            }
 
+            let handshake = await packetGen.craftHandshake(hostname, port, protocolVersion);
             let statusRequest = await packetGen.craftEmptyPacket(0);
 
             portal.write(handshake);

src/packetGenerator.ts

@@ -79,6 +79,40 @@ async function craftPingPacket() {
     return craftedPacket;
 }
 
+export function craftHAProxyMessagePacket(
+    sourceIP: string,
+    destIP: string,
+    sourcePort: number,
+    destPort: number
+): Buffer {
+    const signature = Buffer.from('0D0A0D0A000D0A515549540A', 'hex'); // HAProxy v2 signature
+    const versionCommand = 0x21; // Version 2, command PROXY
+    const protocol = 0x11; // TCP over IPv4
+
+    // Convert IP addresses and ports to binary format
+    const sourceIPParts = sourceIP.split('.').map(part => parseInt(part, 10));
+    const destIPParts = destIP.split('.').map(part => parseInt(part, 10));
+
+    const sourcePortBuffer = Buffer.alloc(2);
+    sourcePortBuffer.writeUInt16BE(sourcePort);
+
+    const destPortBuffer = Buffer.alloc(2);
+    destPortBuffer.writeUInt16BE(destPort);
+
+    const addresses = Buffer.concat([
+        Buffer.from(sourceIPParts),
+        Buffer.from(destIPParts),
+        sourcePortBuffer,
+        destPortBuffer
+    ]);
+
+    const length = addresses.length;
+    const lengthBuffer = Buffer.alloc(2);
+    lengthBuffer.writeUInt16BE(length);
+
+    return Buffer.concat([signature, Buffer.from([versionCommand, protocol]), lengthBuffer, addresses]);
+}
+
 
 
-export default { craftHandshake, craftEmptyPacket, craftPingPacket } 
+export default { craftHandshake, craftEmptyPacket, craftPingPacket, craftHAProxyMessagePacket } 

src/types.ts

@@ -54,6 +54,7 @@ interface _ServerStatusOptions {
     throwOnParseError?: boolean,
     SRVLookup?: boolean,
     JSONParse?: boolean,
+    HAProxy?: boolean
 }
 
 type NotBoth =