PaperMC/patches/server/0612-Add-packet-limiter-config.patch
Bjarne Koll c5a10665b8
Remove wall-time / unused skip tick protection (#11412)
Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.
2024-09-19 16:36:07 +02:00

108 lines
6.1 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Fri, 30 Oct 2020 22:37:16 -0700
Subject: [PATCH] Add packet limiter config
Example config:
packet-limiter:
kick-message: '&cSent too many packets'
limits:
all:
interval: 7.0
max-packet-rate: 500.0
ServerboundPlaceRecipePacket:
interval: 4.0
max-packet-rate: 5.0
action: DROP
all section refers to all incoming packets, the action for all is
hard coded to KICK.
For specific limits, the section name is the class's name,
and an action can be defined: DROP or KICK
If interval or rate are less-than 0, the limit is ignored
diff --git a/src/main/java/net/minecraft/network/Connection.java b/src/main/java/net/minecraft/network/Connection.java
index 2b86415e4ea197c5c44c23072c9a1cda595544a8..4d9f1fc884050993287adfa4578a87da710623fb 100644
--- a/src/main/java/net/minecraft/network/Connection.java
+++ b/src/main/java/net/minecraft/network/Connection.java
@@ -137,6 +137,22 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
return null;
}
// Paper end - add utility methods
+ // Paper start - packet limiter
+ protected final Object PACKET_LIMIT_LOCK = new Object();
+ protected final @Nullable io.papermc.paper.util.IntervalledCounter allPacketCounts = io.papermc.paper.configuration.GlobalConfiguration.get().packetLimiter.allPackets.isEnabled() ? new io.papermc.paper.util.IntervalledCounter(
+ (long)(io.papermc.paper.configuration.GlobalConfiguration.get().packetLimiter.allPackets.interval() * 1.0e9)
+ ) : null;
+ protected final java.util.Map<Class<? extends net.minecraft.network.protocol.Packet<?>>, io.papermc.paper.util.IntervalledCounter> packetSpecificLimits = new java.util.HashMap<>();
+
+ private boolean stopReadingPackets;
+ private void killForPacketSpam() {
+ this.sendPacket(new ClientboundDisconnectPacket(io.papermc.paper.adventure.PaperAdventure.asVanilla(io.papermc.paper.configuration.GlobalConfiguration.get().packetLimiter.kickMessage)), PacketSendListener.thenRun(() -> {
+ this.disconnect(io.papermc.paper.adventure.PaperAdventure.asVanilla(io.papermc.paper.configuration.GlobalConfiguration.get().packetLimiter.kickMessage));
+ }), true);
+ this.setReadOnly();
+ this.stopReadingPackets = true;
+ }
+ // Paper end - packet limiter
public Connection(PacketFlow side) {
this.receiving = side;
@@ -215,6 +231,55 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
if (packetlistener == null) {
throw new IllegalStateException("Received a packet before the packet listener was initialized");
} else {
+ // Paper start - packet limiter
+ if (this.stopReadingPackets) {
+ return;
+ }
+ if (this.allPacketCounts != null ||
+ io.papermc.paper.configuration.GlobalConfiguration.get().packetLimiter.overrides.containsKey(packet.getClass())) {
+ long time = System.nanoTime();
+ synchronized (PACKET_LIMIT_LOCK) {
+ if (this.allPacketCounts != null) {
+ this.allPacketCounts.updateAndAdd(1, time);
+ if (this.allPacketCounts.getRate() >= io.papermc.paper.configuration.GlobalConfiguration.get().packetLimiter.allPackets.maxPacketRate()) {
+ this.killForPacketSpam();
+ return;
+ }
+ }
+
+ for (Class<?> check = packet.getClass(); check != Object.class; check = check.getSuperclass()) {
+ io.papermc.paper.configuration.GlobalConfiguration.PacketLimiter.PacketLimit packetSpecificLimit =
+ io.papermc.paper.configuration.GlobalConfiguration.get().packetLimiter.overrides.get(check);
+ if (packetSpecificLimit == null || !packetSpecificLimit.isEnabled()) {
+ continue;
+ }
+ io.papermc.paper.util.IntervalledCounter counter = this.packetSpecificLimits.computeIfAbsent((Class)check, (clazz) -> {
+ return new io.papermc.paper.util.IntervalledCounter((long)(packetSpecificLimit.interval() * 1.0e9));
+ });
+ counter.updateAndAdd(1, time);
+ if (counter.getRate() >= packetSpecificLimit.maxPacketRate()) {
+ switch (packetSpecificLimit.action()) {
+ case DROP:
+ return;
+ case KICK:
+ String deobfedPacketName = io.papermc.paper.util.ObfHelper.INSTANCE.deobfClassName(check.getName());
+
+ String playerName;
+ if (this.packetListener instanceof net.minecraft.server.network.ServerCommonPacketListenerImpl impl) {
+ playerName = impl.getOwner().getName();
+ } else {
+ playerName = this.getLoggableAddress(net.minecraft.server.MinecraftServer.getServer().logIPs());
+ }
+
+ Connection.LOGGER.warn("{} kicked for packet spamming: {}", playerName, deobfedPacketName.substring(deobfedPacketName.lastIndexOf(".") + 1));
+ this.killForPacketSpam();
+ return;
+ }
+ }
+ }
+ }
+ }
+ // Paper end - packet limiter
if (packetlistener.shouldHandleMessage(packet)) {
try {
Connection.genericsFtw(packet, packetlistener);