Added more stuff to the PacketHandler

eSpigot-Server/src/main/java/com/elevatemc/spigot/eSpigot.java

@@ -19,6 +19,8 @@ import java.util.concurrent.*;
 
 public class eSpigot {
     private final Set<PacketHandler> packetHandlers = new HashSet<>();
+
+    private final Set<PacketHandler> cancellablePacketHandlers  = new HashSet<>();
     private final Set<MovementHandler> movementHandlers = new HashSet<>();
     public static final ScheduledExecutorService EXECUTOR_SERVICE =
             Executors.newSingleThreadScheduledExecutor();
@@ -49,6 +51,7 @@ public class eSpigot {
 
     public void addPacketHandler(PacketHandler handler) {
         Bukkit.getLogger().info("Adding packet handler: " + handler.getClass().getPackage().getName() + "." + handler.getClass().getSimpleName());
+        if (handler.handlesCancellable()) this.cancellablePacketHandlers.add(handler);
         this.packetHandlers.add(handler);
     }
 
@@ -61,6 +64,10 @@ public class eSpigot {
         return this.movementHandlers;
     }
 
+    public Set<PacketHandler> getCancellablePacketHandlers() {
+        return this.cancellablePacketHandlers;
+    }
+
     public Set<PacketHandler> getPacketHandlers() {
         return this.packetHandlers;
     }

eSpigot-Server/src/main/java/com/elevatemc/spigot/handler/PacketHandler.java

@@ -5,13 +5,23 @@ import net.minecraft.server.PlayerConnection;
 
 public interface PacketHandler {
 
-    default void handleReceivedPacket(PlayerConnection connection, Packet<?> packet) {}
+    default void handleReceivedPacket(PlayerConnection connection, Packet<?> packet) {
+    }
 
-    default void handleSentPacket(PlayerConnection connection, Packet<?> packet) {}
+    default void handleSentPacket(PlayerConnection connection, Packet<?> packet) {
+    }
 
     default boolean handleSentPacketCancellable(PlayerConnection connection, Packet<?> packet) {
         return true;
     }
 
+    default boolean handleReceivedPacketCancellable(PlayerConnection connection, Packet<?> packet) {
+        return true;
+    }
+
+    default boolean handlesCancellable() {
+        return false;
+    }
+
 }
 

eSpigot-Server/src/main/java/net/minecraft/server/NetworkManager.java

@@ -3,6 +3,7 @@ package net.minecraft.server;
 import com.elevatemc.spigot.eSpigot;
 import com.elevatemc.spigot.exception.CryptException;
 import com.elevatemc.spigot.exception.ExploitException;
+import com.elevatemc.spigot.handler.PacketHandler;
 import com.velocitypowered.natives.compression.VelocityCompressor; // Paper
 import com.velocitypowered.natives.util.Natives; // Paper
 import com.google.common.collect.Queues;
@@ -157,7 +158,6 @@ public class NetworkManager extends SimpleChannelInboundHandler<Packet<?>> {
         }
 
         this.close(chatmessage);
-//        if (MinecraftServer.getServer().isDebugging()) throwable.printStackTrace(); // Spigot
     }
 
     protected void a(ChannelHandlerContext channelhandlercontext, Packet packet) throws Exception {
@@ -166,8 +166,21 @@ public class NetworkManager extends SimpleChannelInboundHandler<Packet<?>> {
                 packet.a(this.m);
 
                 if (this.m instanceof PlayerConnection) {
+                    //ImHacking Start
+                    for (PacketHandler handler : eSpigot.getInstance().getCancellablePacketHandlers()) {
+                        try {
+                            if (!handler.handleReceivedPacketCancellable((PlayerConnection) this.m, packet)) {
+                                return;
+                            }
+                        } catch (Exception e) {
+                            e.printStackTrace();
+                        }
+                    }
+                    //ImHacking End
                     try {
-                        eSpigot.getInstance().getPacketHandlers().forEach(packetHandler -> packetHandler.handleReceivedPacket((PlayerConnection) this.m, packet));
+                        for (PacketHandler handler : eSpigot.getInstance().getPacketHandlers()) {
+                            handler.handleReceivedPacket((PlayerConnection) this.m, packet);
+                        }
                     } catch (Exception e) {
                         e.printStackTrace();
                     }

eSpigot-Server/src/main/java/net/minecraft/server/PlayerConnection.java

@@ -967,6 +967,7 @@ public class PlayerConnection implements PacketListenerPlayIn, IUpdatePlayerList
         // CraftBukkit end
 
         try {
+            // ImHacking - Start
             // Loop through cancellable handlers first
             for (PacketHandler handler : eSpigot.getInstance().getPacketHandlers()) {
                 try {
@@ -977,13 +978,16 @@ public class PlayerConnection implements PacketListenerPlayIn, IUpdatePlayerList
                     e.printStackTrace();
                 }
             }
-
-            // Loop through normal handlers
             for (PacketHandler handler : eSpigot.getInstance().getPacketHandlers()) {
-                handler.handleSentPacket(this, packet);
+                try {
+                    handler.handleSentPacket(this, packet);
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
             }
-
             this.networkManager.handle(packet);
+            // ImHacking - End
+
         } catch (Throwable throwable) {
             CrashReport crashreport = CrashReport.a(throwable, "Sending packet");
             CrashReportSystemDetails crashreportsystemdetails = crashreport.a("Packet being sent");