check session IDs in all UDP response packets

Author: KurtThiemann

package.json

@@ -1,7 +1,7 @@
 {
   "name": "craftping",
   "type": "module",
-  "version": "2.0.0",
+  "version": "2.0.1",
   "main": "index.js",
   "repository": "github:aternosorg/craftping",
   "scripts": {

src/BedrockPing/BedrockPing.js

@@ -1,16 +1,37 @@
 import UDPClient from "../UDPSocket/UDPClient.js";
 import UnconnectedPing from "../Packet/BedrockPing/UnconnectedPing.js";
 import UnconnectedPong from "../Packet/BedrockPing/UnconnectedPong.js";
+import * as crypto from "node:crypto";
 
 export default class BedrockPing extends UDPClient {
+    /** @type {BigInt} */ sessionId;
+
     /**
      * @return {Promise<UnconnectedPong>}
      */
     async ping() {
+        // Normally, the time field is used for the current ms timestamp, but we're using it as a session ID
+        // to identify which reply belongs to which request.
+        this.sessionId = crypto.randomBytes(8).readBigInt64BE();
         let startTime = BigInt(Date.now());
-        await this.sendPacket(new UnconnectedPing().setTime(startTime).generateClientGUID());
+        await this.sendPacket(new UnconnectedPing().setTime(this.sessionId).generateClientGUID());
         this.signal?.throwIfAborted();
 
-        return new UnconnectedPong().read(await this.readData());
+        // The time field in the response contains the session ID, but we replace it with the start time
+        // in case anyone relies on the time field containing an actual timestamp.
+        return new UnconnectedPong().read(await this.readData()).setTime(startTime);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    shouldAcceptPacket(packet) {
+        let data = packet.getData();
+        if (data.byteLength < 9) {
+            return false;
+        }
+
+        let timestamp = data.readBigInt64BE(1);
+        return timestamp === this.sessionId;
     }
 }

src/Query/Query.js

@@ -52,4 +52,17 @@ export default class Query extends UDPClient {
         this.signal?.throwIfAborted();
         return new FullStatResponse().read(await this.readData());
     }
+
+    /**
+     * @inheritDoc
+     */
+    shouldAcceptPacket(packet) {
+        let data = packet.getData();
+        if (data.byteLength < 5) {
+            return false;
+        }
+
+        let session = data.readUInt32BE(1);
+        return session === this.sessionId;
+    }
 }

src/UDPSocket/UDPSocket.js

@@ -115,6 +115,9 @@ export default class UDPSocket extends EventEmitter {
 
     handleMessage(data, info) {
         let message = new UDPMessage(data, info);
+        if (!this.shouldAcceptPacket(message)) {
+            return this;
+        }
 
         if (this.readQueue.length > 0) {
             this.readQueue.shift().resolve(message);
@@ -166,4 +169,12 @@ export default class UDPSocket extends EventEmitter {
             });
         });
     }
+
+    /**
+     * @param {UDPMessage} packet
+     * @return {boolean}
+     */
+    shouldAcceptPacket(packet) {
+        return true
+    }
 }