Add support for PROXY protocol

api/src/main/java/net/md_5/bungee/api/config/ListenerInfo.java

@@ -3,15 +3,15 @@ package net.md_5.bungee.api.config;
 import java.net.InetSocketAddress;
 import java.util.List;
 import java.util.Map;
-import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
 import lombok.Data;
-import lombok.Getter;
 
 /**
  * Class representing the configuration of a server listener. Used for allowing
  * multiple listeners on different ports.
  */
 @Data
+@AllArgsConstructor
 public class ListenerInfo
 {
 
@@ -67,6 +67,16 @@ public class ListenerInfo
      * Whether to enable udp query.
      */
     private final boolean queryEnabled;
+    /**
+     * Whether to support HAProxy PROXY protocol.
+     */
+    private final boolean proxyProtocol;
+
+    @Deprecated
+    public ListenerInfo(InetSocketAddress host, String motd, int maxPlayers, int tabListSize, List<String> serverPriority, boolean forceDefault, Map<String, String> forcedHosts, String tabListType, boolean setLocalAddress, boolean pingPassthrough, int queryPort, boolean queryEnabled)
+    {
+        this( host, motd, maxPlayers, tabListSize, serverPriority, forceDefault, forcedHosts, tabListType, setLocalAddress, pingPassthrough, queryPort, queryEnabled, false );
+    }
 
     /**
      * Gets the highest priority server to join.

proxy/pom.xml

@@ -29,6 +29,12 @@
             <version>1.0.0</version>
             <scope>compile</scope>
         </dependency>
+        <dependency>
+            <groupId>io.netty</groupId>
+            <artifactId>netty-codec-haproxy</artifactId>
+            <version>${netty.version}</version>
+            <scope>compile</scope>
+        </dependency>
         <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-codec-http</artifactId>

proxy/src/main/java/net/md_5/bungee/BungeeCord.java

@@ -296,6 +296,11 @@ public class BungeeCord extends ProxyServer
     {
         for ( final ListenerInfo info : config.getListeners() )
         {
+            if ( info.isProxyProtocol() )
+            {
+                getLogger().log( Level.WARNING, "Using PROXY protocol for listener {0}, please ensure this listener is adequately firewalled.", info.getHost() );
+            }
+
             ChannelFutureListener listener = new ChannelFutureListener()
             {
                 @Override

proxy/src/main/java/net/md_5/bungee/UserConnection.java

@@ -452,7 +452,7 @@ public final class UserConnection implements ProxiedPlayer
     @Override
     public InetSocketAddress getAddress()
     {
-        return (InetSocketAddress) ch.getHandle().remoteAddress();
+        return ch.getRemoteAddress();
     }
 
     @Override

proxy/src/main/java/net/md_5/bungee/conf/YamlConfig.java

@@ -247,6 +247,7 @@ public class YamlConfig implements ConfigurationAdapter
             boolean query = get( "query_enabled", false, val );
             int queryPort = get( "query_port", 25577, val );
 
+            boolean proxyProtocol = get( "proxy_protocol", false, val );
             List<String> serverPriority = new ArrayList<>( get( "priorities", Collections.EMPTY_LIST, val ) );
 
             // Default server list migration
@@ -271,7 +272,7 @@ public class YamlConfig implements ConfigurationAdapter
             }
             set( "priorities", serverPriority, val );
 
-            ListenerInfo info = new ListenerInfo( address, motd, maxPlayers, tabListSize, serverPriority, forceDefault, forced, value.toString(), setLocalAddress, pingPassthrough, queryPort, query );
+            ListenerInfo info = new ListenerInfo( address, motd, maxPlayers, tabListSize, serverPriority, forceDefault, forced, value.toString(), setLocalAddress, pingPassthrough, queryPort, query, proxyProtocol );
             ret.add( info );
         }
 

proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java

@@ -574,7 +574,7 @@ public class InitialHandler extends PacketHandler implements PendingConnection
     @Override
     public InetSocketAddress getAddress()
     {
-        return (InetSocketAddress) ch.getHandle().remoteAddress();
+        return ch.getRemoteAddress();
     }
 
     @Override

proxy/src/main/java/net/md_5/bungee/netty/ChannelWrapper.java

@@ -5,8 +5,10 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
+import java.net.InetSocketAddress;
 import java.util.concurrent.TimeUnit;
 import lombok.Getter;
+import lombok.Setter;
 import net.md_5.bungee.compress.PacketCompressor;
 import net.md_5.bungee.compress.PacketDecompressor;
 import net.md_5.bungee.protocol.MinecraftDecoder;
@@ -20,6 +22,9 @@ public class ChannelWrapper
 
     private final Channel ch;
     @Getter
+    @Setter
+    private InetSocketAddress remoteAddress;
+    @Getter
     private volatile boolean closed;
     @Getter
     private volatile boolean closing;
@@ -27,6 +32,7 @@ public class ChannelWrapper
     public ChannelWrapper(ChannelHandlerContext ctx)
     {
         this.ch = ctx.channel();
+        this.remoteAddress = (InetSocketAddress) this.ch.remoteAddress();
     }
 
     public void setProtocol(Protocol protocol)

proxy/src/main/java/net/md_5/bungee/netty/HandlerBoss.java

@@ -4,8 +4,10 @@ import com.google.common.base.Preconditions;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.handler.codec.DecoderException;
+import io.netty.handler.codec.haproxy.HAProxyMessage;
 import io.netty.handler.timeout.ReadTimeoutException;
 import java.io.IOException;
+import java.net.InetSocketAddress;
 import java.util.logging.Level;
 import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.connection.CancelSendSignal;
@@ -65,6 +67,20 @@ public class HandlerBoss extends ChannelInboundHandlerAdapter
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
     {
+        if ( msg instanceof HAProxyMessage )
+        {
+            HAProxyMessage proxy = (HAProxyMessage) msg;
+            InetSocketAddress newAddress = new InetSocketAddress( proxy.sourceAddress(), proxy.sourcePort() );
+
+            ProxyServer.getInstance().getLogger().log( Level.FINE, "Set remote address via PROXY {0} -> {1}", new Object[]
+            {
+                channel.getRemoteAddress(), newAddress
+            } );
+
+            channel.setRemoteAddress( newAddress );
+            return;
+        }
+
         if ( handler != null )
         {
             PacketWrapper packet = (PacketWrapper) msg;

proxy/src/main/java/net/md_5/bungee/netty/PipelineUtils.java

@@ -16,6 +16,7 @@ import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.nio.NioDatagramChannel;
 import io.netty.channel.socket.nio.NioServerSocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
+import io.netty.handler.codec.haproxy.HAProxyMessageDecoder;
 import io.netty.handler.timeout.ReadTimeoutHandler;
 import io.netty.util.AttributeKey;
 import io.netty.util.internal.PlatformDependent;
@@ -48,12 +49,19 @@ public class PipelineUtils
         @Override
         protected void initChannel(Channel ch) throws Exception
         {
+            ListenerInfo listener = ch.attr( LISTENER ).get();
+
             BASE.initChannel( ch );
             ch.pipeline().addBefore( FRAME_DECODER, LEGACY_DECODER, new LegacyDecoder() );
             ch.pipeline().addAfter( FRAME_DECODER, PACKET_DECODER, new MinecraftDecoder( Protocol.HANDSHAKE, true, ProxyServer.getInstance().getProtocolVersion() ) );
             ch.pipeline().addAfter( FRAME_PREPENDER, PACKET_ENCODER, new MinecraftEncoder( Protocol.HANDSHAKE, true, ProxyServer.getInstance().getProtocolVersion() ) );
             ch.pipeline().addBefore( FRAME_PREPENDER, LEGACY_KICKER, new KickStringWriter() );
-            ch.pipeline().get( HandlerBoss.class ).setHandler( new InitialHandler( BungeeCord.getInstance(), ch.attr( LISTENER ).get() ) );
+            ch.pipeline().get( HandlerBoss.class ).setHandler( new InitialHandler( BungeeCord.getInstance(), listener ) );
+
+            if ( listener.isProxyProtocol() )
+            {
+                ch.pipeline().addFirst( new HAProxyMessageDecoder() );
+            }
         }
     };
     public static final Base BASE = new Base();