Paper/patches/server/0297-Book-Size-Limits.patch
2021-06-14 09:38:41 +02:00

83 lines
4.3 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Fri, 16 Nov 2018 23:08:50 -0500
Subject: [PATCH] Book Size Limits
Puts some limits on the size of books.
diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java
index 11d628869a9a6eda8bf21a4f213ff23ad753b18e..8bf4d2b8c38c02d6a5b2fea37113689a252f1571 100644
--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
@@ -347,6 +347,13 @@ public class PaperConfig {
}
}
+ public static int maxBookPageSize = 2560;
+ public static double maxBookTotalSizeMultiplier = 0.98D;
+ private static void maxBookSize() {
+ maxBookPageSize = getInt("settings.book-size.page-max", maxBookPageSize);
+ maxBookTotalSizeMultiplier = getDouble("settings.book-size.total-multiplier", maxBookTotalSizeMultiplier);
+ }
+
public static boolean asyncChunks = false;
private static void asyncChunks() {
ConfigurationSection section;
diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 8b716c625c363d7143fe6fbc26d3d674d62a5833..f1a8470d0b314c8fa5eade198cffc1f8cd5e6832 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -1002,6 +1002,52 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
@Override
public void handleEditBook(ServerboundEditBookPacket packet) {
+ // Paper start
+ ItemStack testStack = packet.getBook();
+ if (!this.cserver.isPrimaryThread() && !testStack.isEmpty() && testStack.getTag() != null) {
+ ListTag pageList = testStack.getTag().getList("pages", 8);
+ if (pageList.size() > 100) {
+ ServerGamePacketListenerImpl.LOGGER.warn(this.player.getScoreboardName() + " tried to send a book with too many pages");
+ server.scheduleOnMain(() -> this.disconnect("Book too large!"));
+ return;
+ }
+ long byteTotal = 0;
+ int maxBookPageSize = com.destroystokyo.paper.PaperConfig.maxBookPageSize;
+ double multiplier = Math.max(0.3D, Math.min(1D, com.destroystokyo.paper.PaperConfig.maxBookTotalSizeMultiplier));
+ long byteAllowed = maxBookPageSize;
+ for (int i = 0; i < pageList.size(); ++i) {
+ String testString = pageList.getString(i);
+ int byteLength = testString.getBytes(java.nio.charset.StandardCharsets.UTF_8).length;
+ if (byteLength > 256 * 4) {
+ ServerGamePacketListenerImpl.LOGGER.warn(this.player.getScoreboardName() + " tried to send a book with with a page too large!");
+ server.scheduleOnMain(() -> this.disconnect("Book too large!"));
+ return;
+ }
+ byteTotal += byteLength;
+ int length = testString.length();
+ int multibytes = 0;
+ if (byteLength != length) {
+ for (char c : testString.toCharArray()) {
+ if (c > 127) {
+ multibytes++;
+ }
+ }
+ }
+ byteAllowed += (maxBookPageSize * Math.min(1, Math.max(0.1D, (double) length / 255D))) * multiplier;
+
+ if (multibytes > 1) {
+ // penalize MB
+ byteAllowed -= multibytes;
+ }
+ }
+
+ if (byteTotal > byteAllowed) {
+ ServerGamePacketListenerImpl.LOGGER.warn(this.player.getScoreboardName() + " tried to send too large of a book. Book Size: " + byteTotal + " - Allowed: "+ byteAllowed + " - Pages: " + pageList.size());
+ server.scheduleOnMain(() -> this.disconnect("Book too large!"));
+ return;
+ }
+ }
+ // Paper end
// CraftBukkit start
if (this.lastBookTick + 20 > MinecraftServer.currentTick) {
this.disconnect("Book edited too quickly!");