Paper/Remapped-Spigot-Server-Patches/0311-Book-Size-Limits.patch
2021-06-11 13:56:17 +02:00

81 lines
4.2 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 3139c194f9b1bc3510d51a81f13ae43d00a3dc29..13edb435b3fa65b4980bd7472aa5a5196f4d5b2b 100644
--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
@@ -339,4 +339,11 @@ public class PaperConfig {
velocitySecretKey = secret.getBytes(StandardCharsets.UTF_8);
}
}
+
+ 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);
+ }
}
diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index a6ad7747396f94def688b4d2783137180dc2bb84..b1c505d3fdcc2fb3496f80bee85e4895b9069dcb 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -999,6 +999,52 @@ public class ServerGamePacketListenerImpl implements ServerGamePacketListener {
@Override
public void handleEditBook(ServerboundEditBookPacket packet) {
+ // Paper start
+ ItemStack testStack = packet.getBook();
+ if (!craftServer.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!");