From 7e63bbbab3ac2aeeb7e598d9b036544f2541933f Mon Sep 17 00:00:00 2001 From: Aikar 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 bc74ea2f0..beec4e33c 100644 --- a/src/main/java/com/destroystokyo/paper/PaperConfig.java +++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java @@ -458,4 +458,11 @@ 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/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java index bb4498e0f..a9ef84d0e 100644 --- a/src/main/java/net/minecraft/server/PlayerConnection.java +++ b/src/main/java/net/minecraft/server/PlayerConnection.java @@ -748,6 +748,38 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable { } public void a(PacketPlayInBEdit packetplayinbedit) { + // Paper start + ItemStack testStack = packetplayinbedit.b(); + if (!server.isPrimaryThread() && !testStack.isEmpty() && testStack.getTag() != null) { + NBTTagList pageList = testStack.getTag().getList("pages", 8); + 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; + byteTotal += byteLength; + if (byteTotal > byteAllowed) { + PlayerConnection.LOGGER.warn(this.player.getName() + " tried to send too large of a book. Book Size: " + byteTotal + " - Allowed: "+ byteAllowed + " - Pages: " + pageList.size()); + minecraftServer.postToMainThread(() -> this.disconnect("Book too large!")); + return; + } + int length = testString.length(); + int multibytes = byteLength == length ? byteLength : (int) Math.round((double) byteLength / (double) length); + for (int x = 1; x < multibytes; x++) { + multiplier *= multiplier; + } + byteAllowed += (maxBookPageSize * Math.min(1, Math.max(0.1D, (double) length / 255D))) * multiplier; + multiplier *= multiplier; + + if (multibytes > 1) { + // penalize MB some more + byteAllowed -= length; + } + } + } + // Paper end // CraftBukkit start PlayerConnectionUtils.ensureMainThread(packetplayinbedit, this, this.player.getWorldServer()); if (this.lastBookTick + 20 > MinecraftServer.currentTick) { -- 2.19.2