Paper/Spigot-Server-Patches/0182-Expose-client-protocol-version-and-virtual-host.patch

From 4cf6d5926062d486f4a50f535729040c2f737f20 Mon Sep 17 00:00:00 2001
From: Minecrell <minecrell@minecrell.net>
Date: Tue, 10 Oct 2017 18:45:20 +0200
Subject: [PATCH] Expose client protocol version and virtual host


diff --git a/src/main/java/com/destroystokyo/paper/network/PaperNetworkClient.java b/src/main/java/com/destroystokyo/paper/network/PaperNetworkClient.java
new file mode 100644
index 0000000000..5caca6439d
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/network/PaperNetworkClient.java
@@ -0,0 +1,50 @@
+package com.destroystokyo.paper.network;
+
+import net.minecraft.server.NetworkManager;
+
+import java.net.InetSocketAddress;
+
+import javax.annotation.Nullable;
+
+public class PaperNetworkClient implements NetworkClient {
+
+    private final NetworkManager networkManager;
+
+    PaperNetworkClient(NetworkManager networkManager) {
+        this.networkManager = networkManager;
+    }
+
+    @Override
+    public InetSocketAddress getAddress() {
+        return (InetSocketAddress) this.networkManager.getSocketAddress();
+    }
+
+    @Override
+    public int getProtocolVersion() {
+        return this.networkManager.protocolVersion;
+    }
+
+    @Nullable
+    @Override
+    public InetSocketAddress getVirtualHost() {
+        return this.networkManager.virtualHost;
+    }
+
+    public static InetSocketAddress prepareVirtualHost(String host, int port) {
+        int len = host.length();
+
+        // FML appends a marker to the host to recognize FML clients (\0FML\0)
+        int pos = host.indexOf('\0');
+        if (pos >= 0) {
+            len = pos;
+        }
+
+        // When clients connect with a SRV record, their host contains a trailing '.'
+        if (len > 0 && host.charAt(len -  1) == '.') {
+            len--;
+        }
+
+        return InetSocketAddress.createUnresolved(host.substring(0, len), port);
+    }
+
+}
diff --git a/src/main/java/net/minecraft/server/HandshakeListener.java b/src/main/java/net/minecraft/server/HandshakeListener.java
index 66dda900b6..07d85e5353 100644
--- a/src/main/java/net/minecraft/server/HandshakeListener.java
+++ b/src/main/java/net/minecraft/server/HandshakeListener.java
@@ -15,6 +15,7 @@ public class HandshakeListener implements PacketHandshakingInListener {
 
     private final MinecraftServer a;
     private final NetworkManager b;
+    private NetworkManager getNetworkManager() { return b; } // Paper - OBFHELPER
 
     public HandshakeListener(MinecraftServer minecraftserver, NetworkManager networkmanager) {
         this.a = minecraftserver;
@@ -129,6 +130,10 @@ public class HandshakeListener implements PacketHandshakingInListener {
                 throw new UnsupportedOperationException("Invalid intention " + packethandshakinginsetprotocol.b());
         }
 
+        // Paper start - NetworkClient implementation
+        this.getNetworkManager().protocolVersion = packethandshakinginsetprotocol.getProtocolVersion();
+        this.getNetworkManager().virtualHost = com.destroystokyo.paper.network.PaperNetworkClient.prepareVirtualHost(packethandshakinginsetprotocol.hostname, packethandshakinginsetprotocol.port);
+        // Paper end
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/server/NetworkManager.java b/src/main/java/net/minecraft/server/NetworkManager.java
index d4c59baf8f..ae60f757e3 100644
--- a/src/main/java/net/minecraft/server/NetworkManager.java
+++ b/src/main/java/net/minecraft/server/NetworkManager.java
@@ -62,6 +62,10 @@ public class NetworkManager extends SimpleChannelInboundHandler<Packet<?>> {
     private float t;
     private int u;
     private boolean v;
+    // Paper start - NetworkClient implementation
+    public int protocolVersion;
+    public java.net.InetSocketAddress virtualHost;
+    // Paper end
 
     public NetworkManager(EnumProtocolDirection enumprotocoldirection) {
         this.h = enumprotocoldirection;
diff --git a/src/main/java/net/minecraft/server/PacketHandshakingInSetProtocol.java b/src/main/java/net/minecraft/server/PacketHandshakingInSetProtocol.java
index 4f008e4723..8545146fb1 100644
--- a/src/main/java/net/minecraft/server/PacketHandshakingInSetProtocol.java
+++ b/src/main/java/net/minecraft/server/PacketHandshakingInSetProtocol.java
@@ -35,6 +35,7 @@ public class PacketHandshakingInSetProtocol implements Packet<PacketHandshakingI
         return this.d;
     }
 
+    public int getProtocolVersion() { return c(); } // Paper - OBFHELPER
     public int c() {
         return this.a;
     }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index d064153829..9d2a8a2da0 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -184,6 +184,20 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
         }
     }
 
+    // Paper start - Implement NetworkClient
+    @Override
+    public int getProtocolVersion() {
+        if (getHandle().playerConnection == null) return -1;
+        return getHandle().playerConnection.networkManager.protocolVersion;
+    }
+
+    @Override
+    public InetSocketAddress getVirtualHost() {
+        if (getHandle().playerConnection == null) return null;
+        return getHandle().playerConnection.networkManager.virtualHost;
+    }
+    // Paper end
+
     @Override
     public double getEyeHeight(boolean ignorePose) {
         if (ignorePose) {
-- 
2.22.0