Fixed HAProxy IPv6 issues and added HAProxy support to legacy passthrough

src/main/java/net/raphimc/viaproxy/proxy/client2proxy/Client2ProxyHandler.java

@@ -19,12 +19,10 @@ package net.raphimc.viaproxy.proxy.client2proxy;
 
 import com.google.common.collect.Lists;
 import com.viaversion.viaversion.api.protocol.version.ProtocolVersion;
-import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.SimpleChannelInboundHandler;
-import io.netty.handler.codec.haproxy.*;
 import net.raphimc.netminecraft.constants.ConnectionState;
 import net.raphimc.netminecraft.packet.IPacket;
 import net.raphimc.netminecraft.packet.impl.handshake.C2SHandshakePacket;
@@ -46,14 +44,13 @@ import net.raphimc.viaproxy.proxy.session.DummyProxyConnection;
 import net.raphimc.viaproxy.proxy.session.ProxyConnection;
 import net.raphimc.viaproxy.proxy.util.CloseAndReturn;
 import net.raphimc.viaproxy.proxy.util.ExceptionUtil;
+import net.raphimc.viaproxy.proxy.util.HAProxyUtil;
 import net.raphimc.viaproxy.util.ArrayHelper;
 import net.raphimc.viaproxy.util.logging.Logger;
 
 import java.net.ConnectException;
-import java.net.Inet4Address;
 import java.net.InetSocketAddress;
 import java.nio.channels.UnresolvedAddressException;
-import java.util.Collections;
 import java.util.List;
 import java.util.function.Supplier;
 import java.util.regex.Pattern;
@@ -236,13 +233,7 @@ public class Client2ProxyHandler extends SimpleChannelInboundHandler<IPacket> {
         }
 
         if (Options.SERVER_HAPROXY_PROTOCOL) {
-            final InetSocketAddress sourceAddress = (InetSocketAddress) this.proxyConnection.getC2P().remoteAddress();
+            this.proxyConnection.getChannel().writeAndFlush(HAProxyUtil.createMessage(this.proxyConnection.getC2P(), this.proxyConnection.getChannel(), clientVersion)).addListener(ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE);
-            final InetSocketAddress targetAddress = (InetSocketAddress) this.proxyConnection.getChannel().remoteAddress();
-            final HAProxyProxiedProtocol protocol = sourceAddress.getAddress() instanceof Inet4Address ? HAProxyProxiedProtocol.TCP4 : HAProxyProxiedProtocol.TCP6;
-            final HAProxyTLV tlv = new HAProxyTLV((byte) 0xE0, Unpooled.buffer().writeInt(clientVersion.getOriginalVersion()));
-
-            final HAProxyMessage haProxyMessage = new HAProxyMessage(HAProxyProtocolVersion.V2, HAProxyCommand.PROXY, protocol, sourceAddress.getAddress().getHostAddress(), targetAddress.getAddress().getHostAddress(), sourceAddress.getPort(), targetAddress.getPort(), Collections.singletonList(tlv));
-            this.proxyConnection.getChannel().writeAndFlush(haProxyMessage).addListener(ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE);
         }
 
         handshakeParts[0] = serverAddress.getAddress();

src/main/java/net/raphimc/viaproxy/proxy/client2proxy/passthrough/LegacyClientPassthroughHandler.java

@@ -20,10 +20,14 @@ package net.raphimc.viaproxy.proxy.client2proxy.passthrough;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.*;
+import io.netty.handler.codec.haproxy.HAProxyMessageEncoder;
+import net.raphimc.netminecraft.constants.MCPipeline;
 import net.raphimc.netminecraft.netty.connection.NetClient;
 import net.raphimc.netminecraft.util.ServerAddress;
 import net.raphimc.viaproxy.cli.options.Options;
+import net.raphimc.viaproxy.proxy.proxy2server.Proxy2ServerChannelInitializer;
 import net.raphimc.viaproxy.proxy.util.ExceptionUtil;
+import net.raphimc.viaproxy.proxy.util.HAProxyUtil;
 import net.raphimc.viaproxy.util.logging.Logger;
 
 import java.util.function.Function;
@@ -97,6 +101,10 @@ public class LegacyClientPassthroughHandler extends SimpleChannelInboundHandler<
             this.p2sConnection = null;
             this.c2pChannel.close();
         }
+
+        if (Options.SERVER_HAPROXY_PROTOCOL) {
+            this.p2sConnection.getChannel().writeAndFlush(HAProxyUtil.createMessage(this.c2pChannel, this.p2sConnection.getChannel(), null)).addListener(ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE);
+        }
     }
 
     protected ServerAddress getServerAddress() {
@@ -104,10 +112,13 @@ public class LegacyClientPassthroughHandler extends SimpleChannelInboundHandler<
     }
 
     protected Function<Supplier<ChannelHandler>, ChannelInitializer<Channel>> getChannelInitializerSupplier() {
-        return s -> new ChannelInitializer<Channel>() {
+        return s -> new ChannelInitializer<>() {
             @Override
             protected void initChannel(Channel channel) {
-                channel.pipeline().addLast(s.get());
+                if (Options.SERVER_HAPROXY_PROTOCOL) {
+                    channel.pipeline().addLast(Proxy2ServerChannelInitializer.VIAPROXY_HAPROXY_ENCODER_NAME, HAProxyMessageEncoder.INSTANCE);
+                }
+                channel.pipeline().addLast(MCPipeline.HANDLER_HANDLER_NAME, s.get());
             }
         };
     }

src/main/java/net/raphimc/viaproxy/proxy/proxy2server/Proxy2ServerChannelInitializer.java

@@ -87,17 +87,19 @@ public class Proxy2ServerChannelInitializer extends MinecraftChannelInitializer
         final String password = proxyUrl.getUserInfo() != null && proxyUrl.getUserInfo().contains(":") ? proxyUrl.getUserInfo().split(":")[1] : null;
 
         switch (proxyUrl.getScheme().toUpperCase(Locale.ROOT)) {
-            case "HTTP":
+            case "HTTP", "HTTPS" -> {
-            case "HTTPS":
                 if (username != null && password != null) return new HttpProxyHandler(proxyAddress, username, password);
                 else return new HttpProxyHandler(proxyAddress);
-            case "SOCKS4":
+            }
+            case "SOCKS4" -> {
                 if (username != null) return new Socks4ProxyHandler(proxyAddress, username);
                 else return new Socks4ProxyHandler(proxyAddress);
-            case "SOCKS5":
+            }
+            case "SOCKS5" -> {
                 if (username != null && password != null) return new Socks5ProxyHandler(proxyAddress, username, password);
                 else return new Socks5ProxyHandler(proxyAddress);
             }
+        }
 
         throw new IllegalArgumentException("Unknown proxy type: " + proxyUrl.getScheme());
     }

src/main/java/net/raphimc/viaproxy/proxy/util/HAProxyUtil.java

@@ -0,0 +1,74 @@
+/*
+ * This file is part of ViaProxy - https://github.com/RaphiMC/ViaProxy
+ * Copyright (C) 2023 RK_01/RaphiMC and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package net.raphimc.viaproxy.proxy.util;
+
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
+import io.netty.handler.codec.haproxy.*;
+import net.raphimc.vialoader.util.VersionEnum;
+
+import java.net.*;
+import java.util.ArrayList;
+import java.util.List;
+
+public class HAProxyUtil {
+
+    public static HAProxyMessage createMessage(final Channel sourceChannel, final Channel targetChannel, final VersionEnum clientVersion) {
+        final InetSocketAddress sourceAddress = (InetSocketAddress) sourceChannel.remoteAddress();
+        final InetSocketAddress targetAddress = (InetSocketAddress) targetChannel.remoteAddress();
+        final HAProxyProxiedProtocol protocol = sourceAddress.getAddress() instanceof Inet4Address ? HAProxyProxiedProtocol.TCP4 : HAProxyProxiedProtocol.TCP6;
+        final List<HAProxyTLV> tlvs = new ArrayList<>();
+        if (clientVersion != null) {
+            tlvs.add(new HAProxyTLV((byte) 0xE0, Unpooled.buffer().writeInt(clientVersion.getOriginalVersion())));
+        }
+
+        final String sourceAddressString = sourceAddress.getAddress().getHostAddress();
+        final String targetAddressString = protocol.addressFamily().equals(HAProxyProxiedProtocol.AddressFamily.AF_IPv6) ? getIPv6Address(targetAddress.getHostString()).getHostAddress() : getIPv4Address(targetAddress.getHostString()).getHostAddress();
+
+        return new HAProxyMessage(HAProxyProtocolVersion.V2, HAProxyCommand.PROXY, protocol, sourceAddressString, targetAddressString, sourceAddress.getPort(), targetAddress.getPort(), tlvs);
+    }
+
+    private static Inet6Address getIPv6Address(final String host) {
+        try {
+            final InetAddress[] addresses = InetAddress.getAllByName(host);
+            for (InetAddress addr : addresses) {
+                if (addr instanceof Inet6Address) {
+                    return (Inet6Address) addr;
+                }
+            }
+        } catch (UnknownHostException e) {
+            throw new RuntimeException(e);
+        }
+        return null;
+    }
+
+    private static Inet4Address getIPv4Address(final String host) {
+        try {
+            final InetAddress[] addresses = InetAddress.getAllByName(host);
+            for (InetAddress addr : addresses) {
+                if (addr instanceof Inet4Address) {
+                    return (Inet4Address) addr;
+                }
+            }
+        } catch (UnknownHostException e) {
+            throw new RuntimeException(e);
+        }
+        return null;
+    }
+
+}