From 0000000000000000000000000000000000000000 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/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java index 2e35c6cfdf0cded5adc9f512612faaa68876961c..d69b678b2611f3d1b1ef64541863256868969671 100644 --- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java +++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java @@ -1043,6 +1043,40 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl @Override public void handleEditBook(ServerboundEditBookPacket packet) { + // Paper start - Book size limits + if (!this.cserver.isPrimaryThread()) { + List pageList = packet.pages(); + long byteTotal = 0; + int maxBookPageSize = io.papermc.paper.configuration.GlobalConfiguration.get().itemValidation.bookSize.pageMax; + double multiplier = Math.clamp(io.papermc.paper.configuration.GlobalConfiguration.get().itemValidation.bookSize.totalMultiplier, 0.3D, 1D); + long byteAllowed = maxBookPageSize; + for (String testString : pageList) { + int byteLength = testString.getBytes(java.nio.charset.StandardCharsets.UTF_8).length; + byteTotal += byteLength; + int length = testString.length(); + int multibytes = 0; + if (byteLength != length) { + for (char c : testString.toCharArray()) { + if (c > 127) { + multibytes++; + } + } + } + byteAllowed += maxBookPageSize * Math.clamp((double) length / 255D, 0.1D, 1) * multiplier; + + if (multibytes > 1) { + // penalize MB + byteAllowed -= multibytes; + } + } + + if (byteTotal > byteAllowed) { + ServerGamePacketListenerImpl.LOGGER.warn("{} tried to send a book too large. Book size: {} - Allowed: {} - Pages: {}", this.player.getScoreboardName(), byteTotal, byteAllowed, pageList.size()); + this.disconnect(Component.literal("Book too large!")); + return; + } + } + // Paper end - Book size limits // CraftBukkit start if (this.lastBookTick + 20 > MinecraftServer.currentTick) { this.disconnect(Component.literal("Book edited too quickly!"));