PaperMC/patches/server/0221-Break-up-and-make-tab-spam-limits-configurable.patch

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 bcceb9d18524ddcf7cdf2ab6dcb95a67f1155414..816b53894c6420a6b1603252e53facacecc07c52 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -7,6 +7,7 @@ import com.mojang.brigadier.ParseResults;
 import com.mojang.brigadier.StringReader;
 import com.mojang.brigadier.suggestion.Suggestions;
 import com.mojang.logging.LogUtils;
+import io.papermc.paper.configuration.GlobalConfiguration;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap.Entry;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMaps;
 import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
@@ -272,6 +273,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
     private int tickCount;
     private int ackBlockChangesUpTo = -1;
     private final TickThrottler chatSpamThrottler = new TickThrottler(20, 200);
+    private final TickThrottler tabSpamThrottler = new TickThrottler(GlobalConfiguration.get().spamLimiter.tabSpamIncrement, GlobalConfiguration.get().spamLimiter.tabSpamLimit); // Paper - configurable tab spam limits
     private final TickThrottler dropSpamThrottler = new TickThrottler(20, 1480);
     private double firstGoodX;
     private double firstGoodY;
@@ -387,6 +389,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
 
         this.keepConnectionAlive();
         this.chatSpamThrottler.tick();
+        this.tabSpamThrottler.tick(); // Paper - configurable tab spam limits
         this.dropSpamThrottler.tick();
         if (this.player.getLastActionTime() > 0L && this.server.getPlayerIdleTimeout() > 0 && Util.getMillis() - this.player.getLastActionTime() > (long) this.server.getPlayerIdleTimeout() * 1000L * 60L) {
             this.player.resetLastActionTime(); // CraftBukkit - SPIGOT-854
@@ -722,7 +725,7 @@ 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.chatSpamThrottler.isIncrementAndUnderThreshold(1, 500) && !this.server.getPlayerList().isOp(this.player.getGameProfile()) && !this.server.isSingleplayerOwner(this.player.getGameProfile())) {
+        if (!this.tabSpamThrottler.isIncrementAndUnderThreshold() && !this.server.getPlayerList().isOp(this.player.getGameProfile()) && !this.server.isSingleplayerOwner(this.player.getGameProfile())) { // Paper - configurable tab spam limits
             this.disconnect(Component.translatable("disconnect.spam"));
             return;
         }