Paper/patches/server/1030-Lag-compensation-ticks.patch
Owen 89d51d5f29
Allow enabling sand duping (#10191)
Because this exploit has been widely known for years and has not been fixed by Mojang, we decided that it was worth allowing people to toggle it on/off due to how easy it is to make it configurable.

It should be noted that this decision does not promise all future exploits will be configurable.
2024-03-03 17:05:34 -05:00

130 lines
7.8 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Sat, 23 Sep 2023 22:05:35 -0700
Subject: [PATCH] Lag compensation ticks
Areas affected by lag comepnsation:
- Block breaking and destroying
- Eating food items
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index f12bf36a247a47b8d831536a4fefd2a2ce424494..d06185566b447c432d4dc2e3ba04d121bcdbc71b 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -311,6 +311,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
public volatile Thread shutdownThread; // Paper
public volatile boolean abnormalExit = false; // Paper
+ public static final long SERVER_INIT = System.nanoTime(); // Paper - Lag compensation
public static <S extends MinecraftServer> S spin(Function<Thread, S> serverFactory) {
AtomicReference<S> atomicreference = new AtomicReference();
@@ -1693,6 +1694,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
worldserver.hasPhysicsEvent = org.bukkit.event.block.BlockPhysicsEvent.getHandlerList().getRegisteredListeners().length > 0; // Paper - BlockPhysicsEvent
worldserver.hasEntityMoveEvent = io.papermc.paper.event.entity.EntityMoveEvent.getHandlerList().getRegisteredListeners().length > 0; // Paper - Add EntityMoveEvent
net.minecraft.world.level.block.entity.HopperBlockEntity.skipHopperEvents = worldserver.paperConfig().hopper.disableMoveEvent || org.bukkit.event.inventory.InventoryMoveItemEvent.getHandlerList().getRegisteredListeners().length == 0; // Paper - Perf: Optimize Hoppers
+ worldserver.updateLagCompensationTick(); // Paper - lag compensation
this.profiler.push(() -> {
return worldserver + " " + worldserver.dimension().location();
diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index c9405cbea1202e5603dde42637cf2a78592b92e1..8a5abc320137d045acba0c87cef9f2912d78b6fb 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -565,6 +565,17 @@ public class ServerLevel extends Level implements WorldGenLevel {
return player != null && player.level() == this ? player : null;
}
// Paper end - optimise getPlayerByUUID
+ // Paper start - lag compensation
+ private long lagCompensationTick = net.minecraft.server.MinecraftServer.SERVER_INIT;
+
+ public long getLagCompensationTick() {
+ return this.lagCompensationTick;
+ }
+
+ public void updateLagCompensationTick() {
+ this.lagCompensationTick = (System.nanoTime() - net.minecraft.server.MinecraftServer.SERVER_INIT) / (java.util.concurrent.TimeUnit.MILLISECONDS.toNanos(50L));
+ }
+ // Paper end - lag compensation
// Add env and gen to constructor, IWorldDataServer -> WorldDataServer
public ServerLevel(MinecraftServer minecraftserver, Executor executor, LevelStorageSource.LevelStorageAccess convertable_conversionsession, PrimaryLevelData iworlddataserver, ResourceKey<Level> resourcekey, LevelStem worlddimension, ChunkProgressListener worldloadlistener, boolean flag, long i, List<CustomSpawner> list, boolean flag1, @Nullable RandomSequences randomsequences, org.bukkit.World.Environment env, org.bukkit.generator.ChunkGenerator gen, org.bukkit.generator.BiomeProvider biomeProvider) {
diff --git a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
index ef3048a4748113538a0ee0af5b526b2cd51d5c29..a7b217ddbcbf92513bd38101fdfca2075505e267 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
@@ -124,7 +124,7 @@ public class ServerPlayerGameMode {
}
public void tick() {
- this.gameTicks = MinecraftServer.currentTick; // CraftBukkit;
+ this.gameTicks = (int)this.level.getLagCompensationTick(); // CraftBukkit; // Paper - lag compensation
BlockState iblockdata;
if (this.hasDelayedDestroy) {
diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
index 34e06b4f534215f7eead54a3b0467fd5e2d478db..23570a0b1227a840b9c1e6ae326827ea655bb5f7 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -3849,6 +3849,10 @@ public abstract class LivingEntity extends Entity implements Attackable {
this.getEntityData().resendPossiblyDesyncedDataValues(java.util.List.of(DATA_LIVING_ENTITY_FLAGS), serverPlayer);
}
// Paper end - Properly cancel usable items
+ // Paper start - lag compensate eating
+ protected long eatStartTime;
+ protected int totalEatTimeTicks;
+ // Paper end - lag compensate eating
private void updatingUsingItem() {
if (this.isUsingItem()) {
if (ItemStack.isSameItem(this.getItemInHand(this.getUsedItemHand()), this.useItem)) {
@@ -3867,7 +3871,12 @@ public abstract class LivingEntity extends Entity implements Attackable {
this.triggerItemUseEffects(stack, 5);
}
- if (--this.useItemRemaining == 0 && !this.level().isClientSide && !stack.useOnRelease()) {
+ // Paper start - lag compensate eating
+ // we add 1 to the expected time to avoid lag compensating when we should not
+ boolean shouldLagCompensate = this.useItem.getItem().isEdible() && this.eatStartTime != -1 && (System.nanoTime() - this.eatStartTime) > ((1 + this.totalEatTimeTicks) * 50 * (1000 * 1000));
+ if ((--this.useItemRemaining == 0 || shouldLagCompensate) && !this.level().isClientSide && !stack.useOnRelease()) {
+ this.useItemRemaining = 0;
+ // Paper end - lag compensate eating
this.completeUsingItem();
}
@@ -3915,7 +3924,10 @@ public abstract class LivingEntity extends Entity implements Attackable {
if (!itemstack.isEmpty() && !this.isUsingItem() || forceUpdate) { // Paper - Prevent consuming the wrong itemstack
this.useItem = itemstack;
- this.useItemRemaining = itemstack.getUseDuration();
+ // Paper start - lag compensate eating
+ this.useItemRemaining = this.totalEatTimeTicks = itemstack.getUseDuration();
+ this.eatStartTime = System.nanoTime();
+ // Paper end - lag compensate eating
if (!this.level().isClientSide) {
this.setLivingEntityFlag(1, true);
this.setLivingEntityFlag(2, hand == InteractionHand.OFF_HAND);
@@ -3940,7 +3952,10 @@ public abstract class LivingEntity extends Entity implements Attackable {
}
} else if (!this.isUsingItem() && !this.useItem.isEmpty()) {
this.useItem = ItemStack.EMPTY;
- this.useItemRemaining = 0;
+ // Paper start - lag compensate eating
+ this.useItemRemaining = this.totalEatTimeTicks = 0;
+ this.eatStartTime = -1L;
+ // Paper end - lag compensate eating
}
}
@@ -4075,7 +4090,10 @@ public abstract class LivingEntity extends Entity implements Attackable {
}
this.useItem = ItemStack.EMPTY;
- this.useItemRemaining = 0;
+ // Paper start - lag compensate eating
+ this.useItemRemaining = this.totalEatTimeTicks = 0;
+ this.eatStartTime = -1L;
+ // Paper end - lag compensate eating
}
public boolean isBlocking() {