PaperMC/Spigot-Server-Patches/0173-Expose-client-protocol-version-and-virtual-host.patch

From 0000000000000000000000000000000000000000 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 0000000000000000000000000000000000000000..5caca6439d2135e34880d501397fe2ea197d7249
--- /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 ad2861cde180403069c96f5fd7e4d26ee918bbea..07d5036ce3b04c78f332deed65b9177b70b4361a 100644
--- a/src/main/java/net/minecraft/server/HandshakeListener.java
+++ b/src/main/java/net/minecraft/server/HandshakeListener.java
@@ -133,6 +133,10 @@ 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 5a0129d007459fbb868784f53585fd26f495358c..aeee6bfbc1c0113beef35bf33e8c6928a1db2844 100644
--- a/src/main/java/net/minecraft/server/NetworkManager.java
+++ b/src/main/java/net/minecraft/server/NetworkManager.java
@@ -60,6 +60,10 @@ public class NetworkManager extends SimpleChannelInboundHandler<Packet<?>> {
     private float s;
     private int t;
     private boolean u;
+    // 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 4f008e4723d2cb0bcabb2d5621203d63c40c4923..8545146fb1f093f821e3b966d9337049575c6773 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 6ca7a7a3267d3c8477c8333dea9ac2bbad230056..6eb02d0a69a0375ba099f776636de765612911e5 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -188,6 +188,20 @@ 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) {