Use connection state to optimise packet type detection

src/Connection.ts

@@ -51,7 +51,7 @@ class Connection {
     /** @internal */
     public incomingPacketFragment(data: number) {
         if (this.currentPacketFragment.push(data)) {
-            const p = this.currentPacketFragment.getTypedClient();
+            const p = this.currentPacketFragment.getTypedClient(this);
             if (p) {
                 p.execute(this, this.server);
                 this.server.emit("packet", p, this);

src/Packet.ts

@@ -2,6 +2,7 @@ import ParsedPacket from "./ParsedPacket.js";
 import {TypedClientPacket, TypedClientPacketStatic} from "./types/TypedPacket";
 import HandshakePacket from "./packet/client/HandshakePacket.js";
 import LoginPacket from "./packet/client/LoginPacket.js";
+import Connection from "./Connection";
 
 export default class Packet {
     readonly #data: number[];
@@ -197,9 +198,9 @@ export default class Packet {
     /**
      * Get typed client packet
      */
-    public getTypedClient(): TypedClientPacket | null {
+    public getTypedClient(conn: Connection): TypedClientPacket | null {
         for (const type of Packet.clientTypes) {
-            const p = type.isThisPacket(this.parse());
+            const p = type.isThisPacket(this.parse(), conn);
             if (p !== null) return p;
         }
         return null;

src/packet/client/HandshakePacket.ts

@@ -31,9 +31,10 @@ export default class HandshakePacket {
 
     public static readonly id = 0x00;
 
-    public static isThisPacket(data: ParsedPacket): TypedClientPacket | null {
-        const p = new this(data);
+    public static isThisPacket(data: ParsedPacket, conn: Connection): TypedClientPacket | null {
+        if (conn.state !== Connection.State.NONE) return null;
         try {
+            const p = new this(data);
             return (p.packet.id === this.id && p.data.nextState === 2) ? p : null;
         }
         catch {

src/packet/client/LoginPacket.ts

@@ -30,9 +30,10 @@ export default class LoginPacket {
 
     public static readonly id = 0x00;
 
-    public static isThisPacket(data: ParsedPacket): TypedClientPacket | null {
-        const p = new this(data);
+    public static isThisPacket(data: ParsedPacket, conn: Connection): TypedClientPacket | null {
+        if (conn.state !== Connection.State.LOGIN) return null;
         try {
+            const p = new this(data);
             return (p.packet.id === this.id && p.data.username !== null && p.data.username.match(/^[.*]?[A-Za-z0-9_]{3,16}$/) !== null) ? p : null;
         }
         catch {

src/types/TypedPacket.d.ts

@@ -13,5 +13,5 @@ export interface TypedClientPacketStatic {
 
     readonly id: number;
 
-    isThisPacket(data: ParsedPacket): TypedClientPacket | null;
+    isThisPacket(data: ParsedPacket, conn: Connection): TypedClientPacket | null;
 }