From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Sun, 29 Jul 2018 05:02:15 +0100
Subject: [PATCH] Break up and make tab spam limits configurable

Due to the changes in 1.13, clients will send a tab completion request
for all bukkit commands in order to factor in the lack of support for
brigadier and provide backwards support in the API.

Craftbukkit, however; has moved the chat spam limiter to also interact
with the tab completion request, which while good for avoiding abuse,
causes 1.13 clients to easilly be kicked from a server in bukkit due
to this. Removing the spam limit could cause issues for servers, however,
there is no way for servers to manipulate this without blindly cancelling
kick events, which only causes additional complications. This also causes
issues in that the tab spam limit and chat share the same field but different
limits, meaning that a player having typed a long command may be kicked from
the server.

Splitting the field up and making it configurable allows for server owners
to take the burden of this into their own hand without having to rely on
plugins doing unsafe things.

diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 2e2bf7ba0a2511128cac1ff47b9a38a67b61522c..14dc58263afbdafb576bd10f7b98403466093834 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -256,6 +256,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
     private int ackBlockChangesUpTo = -1;
     // CraftBukkit start - multithreaded fields
     private final AtomicInteger chatSpamTickCount = new AtomicInteger();
+    private final java.util.concurrent.atomic.AtomicInteger tabSpamLimiter = new java.util.concurrent.atomic.AtomicInteger(); // Paper - configurable tab spam limits
     // CraftBukkit end
     private int dropSpamTickCount;
     private double firstGoodX;
@@ -373,6 +374,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
         this.keepConnectionAlive();
         // CraftBukkit start
         for (int spam; (spam = this.chatSpamTickCount.get()) > 0 && !this.chatSpamTickCount.compareAndSet(spam, spam - 1); ) ;
+        if (tabSpamLimiter.get() > 0) tabSpamLimiter.getAndDecrement(); // Paper - configurable tab spam limits
         /* Use thread-safe field access instead
         if (this.chatSpamTickCount > 0) {
             --this.chatSpamTickCount;
@@ -696,7 +698,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
     public void handleCustomCommandSuggestions(ServerboundCommandSuggestionPacket packet) {
         // PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel()); // Paper - AsyncTabCompleteEvent; run this async
         // CraftBukkit start
-        if (this.chatSpamTickCount.addAndGet(1) > 500 && !this.server.getPlayerList().isOp(this.player.getGameProfile())) {
+        if (this.chatSpamTickCount.addAndGet(io.papermc.paper.configuration.GlobalConfiguration.get().spamLimiter.tabSpamIncrement) > io.papermc.paper.configuration.GlobalConfiguration.get().spamLimiter.tabSpamLimit && !this.server.getPlayerList().isOp(this.player.getGameProfile())) { // Paper - configurable tab spam limits
             server.scheduleOnMain(() -> this.disconnect(Component.translatable("disconnect.spam"))); // Paper - AsyncTabCompleteEvent
             return;
         }