From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Aikar Date: Fri, 15 Feb 2019 01:08:19 -0500 Subject: [PATCH] Allow Saving of Oversized Chunks Note 1.17 update: With 1.17, Entities are no longer stored in chunk slices, so this needs updating!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! The Minecraft World Region File format has a hard cap of 1MB per chunk. This is due to the fact that the header of the file format only allocates a single byte for sector count, meaning a maximum of 256 sectors, at 4k per sector. This limit can be reached fairly easily with books, resulting in the chunk being unable to save to the world. Worse off, is that nothing printed when this occured, and silently performed a chunk rollback on next load. This leads to security risk with duplication and is being actively exploited. This patch catches the too large scenario, falls back and moves any large Entity or Tile Entity into a new compound, and this compound is saved into a different file. On Chunk Load, we check for oversized status, and if so, we load the extra file and merge the Entities and Tile Entities from the oversized chunk back into the level to then be loaded as normal. Once a chunk is returned back to normal size, the oversized flag will clear, and no extra data file will exist. This fix maintains compatability with all existing Anvil Region Format tools as it does not alter the save format. They will just not know about the extra entities. This fix also maintains compatability if someone switches server jars to one without this fix, as the data will remain in the oversized file. Once the server returns to a jar with this fix, the data will be restored. diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java index 307196b2a58d4f8db3e6e3c3517a8004d4908b13..c9fd589b1354ac788b63d163d427e8cc5fbba3c5 100644 --- a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java +++ b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java @@ -18,10 +18,13 @@ import java.nio.file.LinkOption; import java.nio.file.Path; import java.nio.file.StandardCopyOption; import java.nio.file.StandardOpenOption; +import java.util.zip.InflaterInputStream; // Paper import javax.annotation.Nullable; import net.minecraft.Util; import net.minecraft.resources.ResourceLocation; import net.minecraft.util.profiling.jfr.JvmProfiler; +import net.minecraft.nbt.CompoundTag; // Paper +import net.minecraft.nbt.NbtIo; // Paper import net.minecraft.world.level.ChunkPos; import org.slf4j.Logger; @@ -56,6 +59,7 @@ public class RegionFile implements AutoCloseable { public RegionFile(RegionStorageInfo storageKey, Path path, Path directory, RegionFileVersion compressionFormat, boolean dsync) throws IOException { this.header = ByteBuffer.allocateDirect(8192); + initOversizedState(); // Paper this.usedSectors = new RegionBitmap(); this.info = storageKey; this.path = path; @@ -453,6 +457,74 @@ public class RegionFile implements AutoCloseable { } public static final int MAX_CHUNK_SIZE = 500 * 1024 * 1024; // Paper - don't write garbage data to disk if writing serialization fails + // Paper start + private final byte[] oversized = new byte[1024]; + private int oversizedCount; + + private synchronized void initOversizedState() throws IOException { + Path metaFile = getOversizedMetaFile(); + if (Files.exists(metaFile)) { + final byte[] read = java.nio.file.Files.readAllBytes(metaFile); + System.arraycopy(read, 0, oversized, 0, oversized.length); + for (byte temp : oversized) { + oversizedCount += temp; + } + } + } + + private static int getChunkIndex(int x, int z) { + return (x & 31) + (z & 31) * 32; + } + synchronized boolean isOversized(int x, int z) { + return this.oversized[getChunkIndex(x, z)] == 1; + } + synchronized void setOversized(int x, int z, boolean oversized) throws IOException { + final int offset = getChunkIndex(x, z); + boolean previous = this.oversized[offset] == 1; + this.oversized[offset] = (byte) (oversized ? 1 : 0); + if (!previous && oversized) { + oversizedCount++; + } else if (!oversized && previous) { + oversizedCount--; + } + if (previous && !oversized) { + Path oversizedFile = getOversizedFile(x, z); + if (Files.exists(oversizedFile)) { + Files.delete(oversizedFile); + } + } + if (oversizedCount > 0) { + if (previous != oversized) { + writeOversizedMeta(); + } + } else if (previous) { + Path oversizedMetaFile = getOversizedMetaFile(); + if (Files.exists(oversizedMetaFile)) { + Files.delete(oversizedMetaFile); + } + } + } + + private void writeOversizedMeta() throws IOException { + java.nio.file.Files.write(getOversizedMetaFile(), oversized); + } + + private Path getOversizedMetaFile() { + return this.path.getParent().resolve(this.path.getFileName().toString().replaceAll("\\.mca$", "") + ".oversized.nbt"); + } + + private Path getOversizedFile(int x, int z) { + return this.path.getParent().resolve(this.path.getFileName().toString().replaceAll("\\.mca$", "") + "_oversized_" + x + "_" + z + ".nbt"); + } + + synchronized CompoundTag getOversizedData(int x, int z) throws IOException { + Path file = getOversizedFile(x, z); + try (DataInputStream out = new DataInputStream(new java.io.BufferedInputStream(new InflaterInputStream(Files.newInputStream(file))))) { + return NbtIo.read((java.io.DataInput) out); + } + + } + // Paper end private class ChunkBuffer extends ByteArrayOutputStream { private final ChunkPos pos; diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java index 3f6955be976064eb542b5c50a9d6d74457c1833c..c2838ae91b7f078369b63503df57a1eb5d2b0df5 100644 --- a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java +++ b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java @@ -123,6 +123,43 @@ public class RegionFileStorage implements AutoCloseable { } } + // Paper start + private static void printOversizedLog(String msg, Path file, int x, int z) { + org.apache.logging.log4j.LogManager.getLogger().fatal(msg + " (" + file.toString().replaceAll(".+[\\\\/]", "") + " - " + x + "," + z + ") Go clean it up to remove this message. /minecraft:tp " + (x<<4)+" 128 "+(z<<4) + " - DO NOT REPORT THIS TO PAPER - You may ask for help on Discord, but do not file an issue. These error messages can not be removed."); + } + + private static CompoundTag readOversizedChunk(RegionFile regionfile, ChunkPos chunkCoordinate) throws IOException { + synchronized (regionfile) { + try (DataInputStream datainputstream = regionfile.getChunkDataInputStream(chunkCoordinate)) { + CompoundTag oversizedData = regionfile.getOversizedData(chunkCoordinate.x, chunkCoordinate.z); + CompoundTag chunk = NbtIo.read((DataInput) datainputstream); + if (oversizedData == null) { + return chunk; + } + CompoundTag oversizedLevel = oversizedData.getCompound("Level"); + + mergeChunkList(chunk.getCompound("Level"), oversizedLevel, "Entities", "Entities"); + mergeChunkList(chunk.getCompound("Level"), oversizedLevel, "TileEntities", "TileEntities"); + + return chunk; + } catch (Throwable throwable) { + throwable.printStackTrace(); + throw throwable; + } + } + } + + private static void mergeChunkList(CompoundTag level, CompoundTag oversizedLevel, String key, String oversizedKey) { + net.minecraft.nbt.ListTag levelList = level.getList(key, net.minecraft.nbt.Tag.TAG_COMPOUND); + net.minecraft.nbt.ListTag oversizedList = oversizedLevel.getList(oversizedKey, net.minecraft.nbt.Tag.TAG_COMPOUND); + + if (!oversizedList.isEmpty()) { + levelList.addAll(oversizedList); + level.put(key, levelList); + } + } + // Paper end + @Nullable public CompoundTag read(ChunkPos pos) throws IOException { // CraftBukkit start - SPIGOT-5680: There's no good reason to preemptively create files on read, save that for writing @@ -134,6 +171,12 @@ public class RegionFileStorage implements AutoCloseable { try { // Paper DataInputStream datainputstream = regionfile.getChunkDataInputStream(pos); + // Paper start + if (regionfile.isOversized(pos.x, pos.z)) { + printOversizedLog("Loading Oversized Chunk!", regionfile.getPath(), pos.x, pos.z); + return readOversizedChunk(regionfile, pos); + } + // Paper end CompoundTag nbttagcompound; label43: { @@ -225,6 +268,7 @@ public class RegionFileStorage implements AutoCloseable { try { NbtIo.write(nbt, (DataOutput) dataoutputstream); + regionfile.setOversized(pos.x, pos.z, false); // Paper - We don't do this anymore, mojang stores differently, but clear old meta flag if it exists to get rid of our own meta file once last oversized is gone // Paper start - don't write garbage data to disk if writing serialization fails dataoutputstream.close(); // Only write if successful } catch (final RegionFileSizeException e) {