From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Nassim Jahnke Date: Wed, 1 Dec 2021 12:36:25 +0100 Subject: [PATCH] Prevent sending oversized item data in equipment and metadata diff --git a/src/main/java/net/minecraft/network/syncher/EntityDataSerializers.java b/src/main/java/net/minecraft/network/syncher/EntityDataSerializers.java index f9e15908143f4453c2a5817b412e8a13554553f0..06498788c169133bd563c5a87192b71802c4d4df 100644 --- a/src/main/java/net/minecraft/network/syncher/EntityDataSerializers.java +++ b/src/main/java/net/minecraft/network/syncher/EntityDataSerializers.java @@ -42,7 +42,7 @@ public class EntityDataSerializers { public static final EntityDataSerializer ITEM_STACK = new EntityDataSerializer() { @Override public void write(FriendlyByteBuf buf, ItemStack value) { - buf.writeItem(value); + buf.writeItem(net.minecraft.world.entity.LivingEntity.sanitizeItemStack(value, true)); // Paper - prevent oversized data } @Override diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java index 75b722ebc6c1fc6a45a0d3a3e57b5f131f2cf815..0a86e72e50d4aab7d19f588c3f11d7465c6fe817 100644 --- a/src/main/java/net/minecraft/server/level/ServerEntity.java +++ b/src/main/java/net/minecraft/server/level/ServerEntity.java @@ -335,7 +335,10 @@ public class ServerEntity { ItemStack itemstack = ((LivingEntity) this.entity).getItemBySlot(enumitemslot); if (!itemstack.isEmpty()) { - list.add(Pair.of(enumitemslot, itemstack.copy())); + // Paper start - prevent oversized data + final ItemStack sanitized = LivingEntity.sanitizeItemStack(itemstack.copy(), false); + list.add(Pair.of(enumitemslot, sanitized)); + // Paper end - prevent oversized data } } diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java index 24a7ded2966b5431bae938b4ac903683fa2a3da7..d43ac664cae11d2f7d0c6965a57234430086f8ca 100644 --- a/src/main/java/net/minecraft/world/entity/LivingEntity.java +++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java @@ -3187,7 +3187,10 @@ public abstract class LivingEntity extends Entity implements Attackable { equipmentChanges.forEach((enumitemslot, itemstack) -> { ItemStack itemstack1 = itemstack.copy(); - list.add(Pair.of(enumitemslot, itemstack1)); + // Paper start - prevent oversized data + ItemStack toSend = sanitizeItemStack(itemstack1, true); + list.add(Pair.of(enumitemslot, toSend)); + // Paper end - prevent oversized data switch (enumitemslot.getType()) { case HAND: this.setLastHandItem(enumitemslot, itemstack1); @@ -3200,6 +3203,34 @@ public abstract class LivingEntity extends Entity implements Attackable { ((ServerLevel) this.level()).getChunkSource().broadcast(this, new ClientboundSetEquipmentPacket(this.getId(), list)); } + // Paper start - prevent oversized data + public static ItemStack sanitizeItemStack(final ItemStack itemStack, final boolean copyItemStack) { + if (itemStack.isEmpty() || !itemStack.hasTag()) { + return itemStack; + } + + final ItemStack copy = copyItemStack ? itemStack.copy() : itemStack; + final CompoundTag tag = copy.getTag(); + if (copy.is(Items.BUNDLE) && tag.get("Items") instanceof ListTag oldItems && !oldItems.isEmpty()) { + // Bundles change their texture based on their fullness. + org.bukkit.inventory.meta.BundleMeta bundleMeta = (org.bukkit.inventory.meta.BundleMeta) copy.asBukkitMirror().getItemMeta(); + int sizeUsed = 0; + for (org.bukkit.inventory.ItemStack item : bundleMeta.getItems()) { + int scale = 64 / item.getMaxStackSize(); + sizeUsed += scale * item.getAmount(); + } + // Now we add a single fake item that uses the same amount of slots as all other items. + ListTag items = new ListTag(); + items.add(new ItemStack(Items.PAPER, sizeUsed).save(new CompoundTag())); + tag.put("Items", items); + } + if (tag.get("BlockEntityTag") instanceof CompoundTag blockEntityTag) { + blockEntityTag.remove("Items"); + } + return copy; + } + // Paper end - prevent oversized data + private ItemStack getLastArmorItem(EquipmentSlot slot) { return (ItemStack) this.lastArmorItemStacks.get(slot.getIndex()); }