From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Spottedleaf 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 8b7e50c0bce9ff201e92fc6fff8934ea17f1b293..2ae08b21c63490bbf8cd870f9585d82ed131f815 100644 --- a/src/main/java/net/minecraft/network/Connection.java +++ b/src/main/java/net/minecraft/network/Connection.java @@ -132,6 +132,22 @@ public class Connection extends SimpleChannelInboundHandler> { 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>, 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; @@ -224,6 +240,55 @@ public class Connection extends SimpleChannelInboundHandler> { 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);