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 af966cd751b73af9e01c8561d3e74972a241b0f5..8a6fd7616df0f81e4b67a217846786d9c7bcd21f 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -259,6 +259,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
     private long keepAliveChallenge;
     // 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;
@@ -413,6 +414,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
         this.server.getProfiler().pop();
         // CraftBukkit start
         for (int spam; (spam = this.chatSpamTickCount.get()) > 0 && !this.chatSpamTickCount.compareAndSet(spam, spam - 1); ) ;
+        if (tabSpamLimiter.get() > 0) tabSpamLimiter.getAndDecrement(); // Paper - split to seperate variable
         /* Use thread-safe field access instead
         if (this.chatSpamTickCount > 0) {
             --this.chatSpamTickCount;
@@ -786,7 +788,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
     public void handleCustomCommandSuggestions(ServerboundCommandSuggestionPacket packet) {
         // PacketUtils.ensureRunningOnSameThread(packet, this, this.player.getLevel()); // Paper - 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 start - split and make configurable
             server.scheduleOnMain(() -> this.disconnect(Component.translatable("disconnect.spam", new Object[0]))); // Paper
             return;
         }