From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: ayunami2000 <spwilliamsiam@gmail.com>
Date: Mon, 28 Mar 2022 17:02:21 -0400
Subject: [PATCH] Block server-side chunkbans


diff --git a/src/main/java/net/minecraft/network/PacketEncoder.java b/src/main/java/net/minecraft/network/PacketEncoder.java
index b039a32b805fc02033fa862a1c40c4a51639e69a..b2227f01bc90351a4a3f73fa835dd89bde15632e 100644
--- a/src/main/java/net/minecraft/network/PacketEncoder.java
+++ b/src/main/java/net/minecraft/network/PacketEncoder.java
@@ -5,8 +5,22 @@ import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.MessageToByteEncoder;
 import io.papermc.paper.adventure.PaperAdventure; // Paper
 import java.io.IOException;
+import java.util.Collections;
+import net.minecraft.ChatFormatting;
+import net.minecraft.core.NonNullList;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.Packet;
 import net.minecraft.network.protocol.PacketFlow;
+import net.minecraft.network.protocol.game.ClientboundBlockEntityDataPacket;
+import net.minecraft.network.protocol.game.ClientboundChatPacket;
+import net.minecraft.network.protocol.game.ClientboundContainerSetContentPacket;
+import net.minecraft.network.protocol.game.ClientboundContainerSetSlotPacket;
+import net.minecraft.network.protocol.game.ClientboundLevelChunkPacket;
+import net.minecraft.network.protocol.game.ClientboundMapItemDataPacket;
+import net.minecraft.network.protocol.game.ClientboundSetEntityDataPacket;
+import net.minecraft.network.protocol.game.ClientboundSetEquipmentPacket;
+import net.minecraft.world.item.ItemStack;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.Marker;
@@ -21,6 +35,23 @@ public class PacketEncoder extends MessageToByteEncoder<Packet<?>> {
         this.flow = side;
     }
 
+    // Scissors start
+    private static int tryWrite(Packet packet, FriendlyByteBuf friendlyByteBuf, ChannelHandlerContext channelHandlerContext, int i) {
+        friendlyByteBuf.writeVarInt(i);
+        friendlyByteBuf.adventure$locale = channelHandlerContext.channel().attr(PaperAdventure.LOCALE_ATTRIBUTE).get();
+
+        int j = friendlyByteBuf.writerIndex();
+        packet.write(friendlyByteBuf);
+        int k = friendlyByteBuf.writerIndex() - j;
+        int packetLength = friendlyByteBuf.readableBytes();
+        if (k > 8388608 || packetLength > MAX_PACKET_SIZE) {   
+            throw new SkipPacketException(new IllegalArgumentException("Packet too big (is " + k + "): " + packet));
+        }
+
+        return k;
+    }
+    // Scissors end
+
     @Override
     protected void encode(ChannelHandlerContext channelHandlerContext, Packet<?> packet, ByteBuf byteBuf) throws Exception {
         ConnectionProtocol connectionProtocol = channelHandlerContext.channel().attr(Connection.ATTRIBUTE_PROTOCOL).get();
@@ -36,35 +67,68 @@ public class PacketEncoder extends MessageToByteEncoder<Packet<?>> {
                 throw new IOException("Can't serialize unregistered packet");
             } else {
                 FriendlyByteBuf friendlyByteBuf = new FriendlyByteBuf(byteBuf);
-                friendlyByteBuf.writeVarInt(integer);
-                friendlyByteBuf.adventure$locale = channelHandlerContext.channel().attr(PaperAdventure.LOCALE_ATTRIBUTE).get(); // Paper
-
+                // Scissors start
+                int k;
                 try {
-                    int i = friendlyByteBuf.writerIndex();
-                    packet.write(friendlyByteBuf);
-                    int j = friendlyByteBuf.writerIndex() - i;
-                    if (j > 8388608) {
-                        throw new IllegalArgumentException("Packet too big (is " + j + ", should be less than 8388608): " + packet);
-                    }
+                    k = tryWrite(packet, friendlyByteBuf, channelHandlerContext, integer);
                 } catch (Throwable var9) {
-                    LOGGER.error("Packet encoding of packet ID {} threw (skippable? {})", integer, packet.isSkippable(), var9); // Paper - WHAT WAS IT? WHO DID THIS TO YOU? WHAT DID YOU SEE?
-                    if (packet.isSkippable()) {
-                        throw new SkipPacketException(var9);
-                    } else {
-                        throw var9;
+                    packet = capPacket(packet, integer);
+                    if (packet == null) {
+                        throw new SkipPacketException(new IllegalArgumentException("Packet too big: " + packet));
                     }
+                    friendlyByteBuf.clear();
+                    k = tryWrite(packet, friendlyByteBuf, channelHandlerContext, integer);
                 }
-
-                // Paper start
-                int packetLength = friendlyByteBuf.readableBytes();
-                if (packetLength > MAX_PACKET_SIZE) {
-                    throw new PacketTooLargeException(packet, packetLength);
-                }
-                // Paper end
+                // Scissors end
             }
         }
     }
 
+    // Scissors start
+    private static Packet capPacket(Packet packet, int i)
+    {
+        if (packet instanceof ClientboundBlockEntityDataPacket blockEntityDataPacket)
+        {
+            packet = new ClientboundBlockEntityDataPacket(blockEntityDataPacket.getPos(), blockEntityDataPacket.getType(), new CompoundTag());
+        }
+        else if (packet instanceof ClientboundLevelChunkPacket chunkPacket)
+        {
+            chunkPacket.clearNBT();
+        }
+        else if (packet instanceof ClientboundSetEntityDataPacket)
+        {
+            return null; // Skip
+        }
+        else if (packet instanceof ClientboundContainerSetContentPacket containerSetContentPacket)
+        {
+            packet = new ClientboundContainerSetContentPacket(containerSetContentPacket.getContainerId(), containerSetContentPacket.getStateId(), NonNullList.create(), ItemStack.EMPTY);
+        }
+        else if (packet instanceof ClientboundSetEquipmentPacket setEquipmentPacket)
+        {
+            packet = new ClientboundSetEquipmentPacket(setEquipmentPacket.getEntity(), Collections.emptyList());
+        }
+        else if (packet instanceof ClientboundContainerSetSlotPacket containerSetSlotPacket)
+        {
+            packet = new ClientboundContainerSetSlotPacket(containerSetSlotPacket.getContainerId(), containerSetSlotPacket.getStateId(), containerSetSlotPacket.getSlot(), ItemStack.EMPTY);
+        }
+        else if (packet instanceof ClientboundMapItemDataPacket mapItemDataPacket)
+        {
+            packet = new ClientboundMapItemDataPacket(mapItemDataPacket.getMapId(), mapItemDataPacket.getScale(), mapItemDataPacket.isLocked(), null, null);
+        }
+        else if (packet instanceof ClientboundChatPacket chatPacket)
+        {
+            return null;
+        }
+        else
+        {
+            LOGGER.error("Packet with ID {} was too large and was not caught. Please report this to the Scissors developers.", i);
+            return null;
+        }
+
+        return packet;
+    }
+    // Scissors end
+
     // Paper start
     private static int MAX_PACKET_SIZE = 2097152;
 
diff --git a/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacket.java b/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacket.java
index 60d72e488bc77cd913328be400ca374a873b4561..1af2260e7bab81fca24784172dd31e06e9adb1e1 100644
--- a/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacket.java
+++ b/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacket.java
@@ -50,6 +50,13 @@ public class ClientboundLevelChunkPacket implements Packet<ClientGamePacketListe
     }
     // Paper end
 
+    // Scissors start
+    public void clearNBT() {
+        this.blockEntitiesTags.clear();
+        this.extraPackets.clear();
+    }
+    // Scissors end
+
     // Paper start - Anti-Xray - Add chunk packet info
     @Deprecated public ClientboundLevelChunkPacket(LevelChunk chunk) { this(chunk, true); } // Notice for updates: Please make sure this constructor isn't used anywhere
     public ClientboundLevelChunkPacket(LevelChunk chunk, boolean modifyBlocks) {