Waterfall/BungeeCord-Patches/0044-Provide-an-option-to-disable-entity-metadata-rewriti.patch

From 8525fdb1e67b91ffd9d11342c505ecf351a29619 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Mon, 14 Jan 2019 03:35:21 +0000
Subject: [PATCH] Provide an option to disable entity metadata rewriting

The work here is derived from the research and guidance of
various members of the minecraft community

This patch provides the ability to disable entity remapping,
which creates various incompatability issues with mods, however,
may also create various issues with mods which do not support this,
hence why the configuration option is provided

diff --git a/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java b/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java
index e0baca9c..f3bced0a 100644
--- a/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java
+++ b/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java
@@ -252,4 +252,9 @@ public interface ProxyConfig
      * @return should we disable the tab completion limit for 1.13+ clients
      */
     boolean isDisableModernTabLimiter();
+
+    /**
+     * @return Should we disable entity metadata rewriting?
+     */
+    boolean isDisableEntityMetadataRewrite();
 }
diff --git a/proxy/src/main/java/io/github/waterfallmc/waterfall/conf/WaterfallConfiguration.java b/proxy/src/main/java/io/github/waterfallmc/waterfall/conf/WaterfallConfiguration.java
index 4ff8da6d..e860214f 100644
--- a/proxy/src/main/java/io/github/waterfallmc/waterfall/conf/WaterfallConfiguration.java
+++ b/proxy/src/main/java/io/github/waterfallmc/waterfall/conf/WaterfallConfiguration.java
@@ -42,6 +42,8 @@ public class WaterfallConfiguration extends Configuration {
     private int tabThrottle = 1000;
     private boolean disableModernTabLimiter = true;
 
+    private boolean disableEntityMetadataRewrite = false;
+
     @Override
     public void load() {
         super.load();
@@ -53,6 +55,7 @@ public class WaterfallConfiguration extends Configuration {
         // Throttling options
         tabThrottle = config.getInt("throttling.tab_complete", tabThrottle);
         disableModernTabLimiter = config.getBoolean("disable_modern_tab_limiter", disableModernTabLimiter);
+        disableEntityMetadataRewrite = config.getBoolean("disable_entity_metadata_rewrite", disableEntityMetadataRewrite);
     }
 
     @Override
@@ -79,4 +82,9 @@ public class WaterfallConfiguration extends Configuration {
     public boolean isDisableModernTabLimiter() {
         return disableModernTabLimiter;
     }
+
+    @Override
+    public boolean isDisableEntityMetadataRewrite() {
+        return disableEntityMetadataRewrite;
+    }
 }
diff --git a/proxy/src/main/java/net/md_5/bungee/ServerConnector.java b/proxy/src/main/java/net/md_5/bungee/ServerConnector.java
index 2624dd37..55218447 100644
--- a/proxy/src/main/java/net/md_5/bungee/ServerConnector.java
+++ b/proxy/src/main/java/net/md_5/bungee/ServerConnector.java
@@ -255,7 +255,7 @@ public class ServerConnector extends PacketHandler
             ch.write( new PluginMessage( user.getPendingConnection().getVersion() >= ProtocolConstants.MINECRAFT_1_13 ? "minecraft:register" : "REGISTER", Joiner.on( "\0" ).join( registeredChannels ).getBytes( StandardCharsets.UTF_8 ), false ) );
         }
 
-        if ( user.getSettings() != null )
+        if (!user.isDisableEntityMetadataRewrite() && user.getSettings() != null )
         {
             ch.write( user.getSettings() );
         }
@@ -310,6 +310,7 @@ public class ServerConnector extends PacketHandler
             user.getTabListHandler().onServerChange();
 
             Scoreboard serverScoreboard = user.getServerSentScoreboard();
+            if ( !user.isDisableEntityMetadataRewrite() ) { // Waterfall
             for ( Objective objective : serverScoreboard.getObjectives() )
             {
                 user.unsafe().sendPacket( new ScoreboardObjective( objective.getName(), objective.getValue(), ScoreboardObjective.HealthDisplay.fromString( objective.getType() ), (byte) 1 ) );
@@ -322,6 +323,7 @@ public class ServerConnector extends PacketHandler
             {
                 user.unsafe().sendPacket( new net.md_5.bungee.protocol.packet.Team( team.getName() ) );
             }
+            } // Waterfall
             serverScoreboard.clear();
 
             for ( UUID bossbar : user.getSentBossBars() )
@@ -340,13 +342,34 @@ public class ServerConnector extends PacketHandler
             }
 
             user.setDimensionChange( true );
-            if ( login.getDimension() == user.getDimension() )
+            if ( !user.isDisableEntityMetadataRewrite() && login.getDimension() == user.getDimension() ) // Waterfall - defer
             {
                 user.unsafe().sendPacket( new Respawn( (Integer) login.getDimension() >= 0 ? -1 : 0, login.getWorldName(), login.getSeed(), login.getDifficulty(), login.getGameMode(), login.getPreviousGameMode(), login.getLevelType(), login.isDebug(), login.isFlat(),
                         (byte) 0, login.getDeathLocation(), login.getPortalCooldown() ) );
             }
 
             user.setServerEntityId( login.getEntityId() );
+
+            // Waterfall start
+            if ( user.isDisableEntityMetadataRewrite() ) {
+                // Ensure that we maintain consistency
+                user.setClientEntityId( login.getEntityId() );
+                // Only send if we are not in the same dimension
+                if ( login.getDimension() != user.getDimension() ) // Waterfall - defer
+                {
+                    user.unsafe().sendPacket( new Respawn( (Integer) user.getDimension() >= 0 ? -1 : 0, login.getWorldName(), login.getSeed(), login.getDifficulty(), login.getGameMode(), login.getPreviousGameMode(), login.getLevelType(), login.isDebug(), login.isFlat(), (byte) 0, login.getDeathLocation(), login.getPortalCooldown() ) );
+                }
+                Login modLogin = new Login( login.getEntityId(), login.isHardcore(), login.getGameMode(), login.getPreviousGameMode(), login.getWorldNames(), login.getDimensions(), login.getDimension(), login.getWorldName(), login.getSeed(), login.getDifficulty(),
+                        (byte) user.getPendingConnection().getListener().getTabListSize(), login.getLevelType(), login.getViewDistance(), login.getSimulationDistance(), login.isReducedDebugInfo(), login.isNormalRespawn(), login.isLimitedCrafting(), login.isDebug(), login.isFlat(), login.getDeathLocation(),
+                        login.getPortalCooldown() );
+                user.unsafe().sendPacket(modLogin);
+                // Only send if we're in the same dimension
+                if ( login.getDimension() == user.getDimension() ) // Waterfall - defer
+                {
+                    user.unsafe().sendPacket( new Respawn( (Integer) login.getDimension() >= 0 ? -1 : 0, login.getWorldName(), login.getSeed(), login.getDifficulty(), login.getGameMode(), login.getPreviousGameMode(), login.getLevelType(), login.isDebug(), login.isFlat(), (byte) 0, login.getDeathLocation(), login.getPortalCooldown() ) );
+                }
+            }
+            // Waterfall end
             user.unsafe().sendPacket( new Respawn( login.getDimension(), login.getWorldName(), login.getSeed(), login.getDifficulty(), login.getGameMode(), login.getPreviousGameMode(), login.getLevelType(), login.isDebug(), login.isFlat(),
                     (byte) 0, login.getDeathLocation(), login.getPortalCooldown() ) );
             if ( user.getPendingConnection().getVersion() >= ProtocolConstants.MINECRAFT_1_14 )
diff --git a/proxy/src/main/java/net/md_5/bungee/UserConnection.java b/proxy/src/main/java/net/md_5/bungee/UserConnection.java
index a129dc42..fe6eab9b 100644
--- a/proxy/src/main/java/net/md_5/bungee/UserConnection.java
+++ b/proxy/src/main/java/net/md_5/bungee/UserConnection.java
@@ -778,4 +778,10 @@ public final class UserConnection implements ProxiedPlayer
     {
         return serverSentScoreboard;
     }
+
+    // Waterfall start
+    public boolean isDisableEntityMetadataRewrite() {
+        return entityRewrite == net.md_5.bungee.entitymap.EntityMap_Dummy.INSTANCE;
+    }
+    // Waterfall end
 }
diff --git a/proxy/src/main/java/net/md_5/bungee/connection/DownstreamBridge.java b/proxy/src/main/java/net/md_5/bungee/connection/DownstreamBridge.java
index c412bbab..5966469b 100644
--- a/proxy/src/main/java/net/md_5/bungee/connection/DownstreamBridge.java
+++ b/proxy/src/main/java/net/md_5/bungee/connection/DownstreamBridge.java
@@ -741,6 +741,7 @@ public class DownstreamBridge extends PacketHandler
     @Override
     public void handle(net.md_5.bungee.protocol.packet.EntityEffect entityEffect) throws Exception
     {
+        if (con.isDisableEntityMetadataRewrite()) return; // Waterfall
         // Don't send any potions when switching between servers (which involves a handshake), which can trigger a race
         // condition on the client.
         if (this.con.getForgeClientHandler().isForgeUser() && !this.con.getForgeClientHandler().isHandshakeComplete()) {
@@ -752,6 +753,7 @@ public class DownstreamBridge extends PacketHandler
     @Override
     public void handle(net.md_5.bungee.protocol.packet.EntityRemoveEffect removeEffect) throws Exception
     {
+        if (con.isDisableEntityMetadataRewrite()) return; // Waterfall
         con.getPotions().remove(rewriteEntityId(removeEffect.getEntityId()), removeEffect.getEffectId());
     }
 
diff --git a/proxy/src/main/java/net/md_5/bungee/entitymap/EntityMap.java b/proxy/src/main/java/net/md_5/bungee/entitymap/EntityMap.java
index c033118f..69accd42 100644
--- a/proxy/src/main/java/net/md_5/bungee/entitymap/EntityMap.java
+++ b/proxy/src/main/java/net/md_5/bungee/entitymap/EntityMap.java
@@ -27,6 +27,11 @@ public abstract class EntityMap
     // Returns the correct entity map for the protocol version
     public static EntityMap getEntityMap(int version)
     {
+        // Waterfall start
+        if (net.md_5.bungee.api.ProxyServer.getInstance().getConfig().isDisableEntityMetadataRewrite()) {
+            return EntityMap_Dummy.INSTANCE;
+        }
+        // Waterfall end
         switch ( version )
         {
             case ProtocolConstants.MINECRAFT_1_8:
@@ -300,7 +305,13 @@ public abstract class EntityMap
                     DefinedPacket.readVarInt( packet );
                     break;
                 default:
-                    throw new IllegalArgumentException( "Unknown meta type " + type );
+                    // Waterfall start - Don't lie
+                    if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_13 )
+                    {
+                        type++;
+                    }
+                    throw new IllegalArgumentException( "Unknown meta type " + type  + ": Using mods? refer to disable_entity_metadata_rewrite in waterfall.yml" );
+                    // Waterfall end
             }
         }
 
diff --git a/proxy/src/main/java/net/md_5/bungee/entitymap/EntityMap_Dummy.java b/proxy/src/main/java/net/md_5/bungee/entitymap/EntityMap_Dummy.java
new file mode 100644
index 00000000..cb81d1dd
--- /dev/null
+++ b/proxy/src/main/java/net/md_5/bungee/entitymap/EntityMap_Dummy.java
@@ -0,0 +1,30 @@
+
+package net.md_5.bungee.entitymap;
+
+import io.netty.buffer.ByteBuf;
+// Waterfall start
+
+public class EntityMap_Dummy extends EntityMap {
+
+    public static final EntityMap_Dummy INSTANCE = new EntityMap_Dummy();
+
+    EntityMap_Dummy() {
+    }
+
+    @Override
+    public void rewriteServerbound(ByteBuf packet, int oldId, int newId) {
+    }
+
+    @Override
+    public void rewriteServerbound(ByteBuf packet, int oldId, int newId, int protocolVersion) {
+    }
+
+    @Override
+    public void rewriteClientbound(ByteBuf packet, int oldId, int newId) {
+    }
+
+    @Override
+    public void rewriteClientbound(ByteBuf packet, int oldId, int newId, int protocolVersion) {
+    }
+}
+// Waterfall end
\ No newline at end of file
-- 
2.42.0