Implemented ViaBedrock TransferProvider

src/main/java/net/raphimc/viaproxy/protocolhack/impl/ViaProxyVLLoader.java

@@ -22,6 +22,7 @@ import com.viaversion.viaversion.api.protocol.version.VersionProvider;
 import com.viaversion.viaversion.protocols.protocol1_9to1_8.providers.CompressionProvider;
 import com.viaversion.viaversion.protocols.protocol1_9to1_8.providers.HandItemProvider;
 import net.raphimc.viabedrock.protocol.providers.NettyPipelineProvider;
+import net.raphimc.viabedrock.protocol.providers.TransferProvider;
 import net.raphimc.vialegacy.protocols.classic.protocola1_0_15toc0_28_30.providers.ClassicCustomCommandProvider;
 import net.raphimc.vialegacy.protocols.classic.protocola1_0_15toc0_28_30.providers.ClassicMPPassProvider;
 import net.raphimc.vialegacy.protocols.classic.protocola1_0_15toc0_28_30.providers.ClassicWorldHeightProvider;
@@ -54,6 +55,7 @@ public class ViaProxyVLLoader extends VLLoader {
 
         // ViaBedrock
         Via.getManager().getProviders().use(NettyPipelineProvider.class, new ViaProxyNettyPipelineProvider());
+        Via.getManager().getProviders().use(TransferProvider.class, new ViaProxyTransferProvider());
 
         // ViaProxy plugins
         PluginManager.EVENT_MANAGER.call(new ViaLoadingEvent());

src/main/java/net/raphimc/viaproxy/protocolhack/providers/ViaProxyTransferProvider.java

@@ -0,0 +1,39 @@
+/*
+ * 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.protocolhack.providers;
+
+import com.viaversion.viaversion.api.connection.UserConnection;
+import net.raphimc.viabedrock.protocol.providers.TransferProvider;
+import net.raphimc.viaproxy.protocolhack.viaproxy.ViaBedrockTransferHolder;
+import net.raphimc.viaproxy.proxy.session.ProxyConnection;
+import net.raphimc.viaproxy.proxy.util.CloseAndReturn;
+
+import java.net.InetSocketAddress;
+
+public class ViaProxyTransferProvider extends TransferProvider {
+
+    @Override
+    public void connectToServer(UserConnection user, InetSocketAddress newAddress) {
+        ViaBedrockTransferHolder.addTempRedirect(user.getChannel(), newAddress);
+        try {
+            ProxyConnection.fromUserConnection(user).kickClient("§aThe server transferred you to another server §7(§e"+ newAddress.getHostName() + ":" + newAddress.getPort() + "§7)§a. Please reconnect to ViaProxy.");
+        } catch (CloseAndReturn ignored) {
+        }
+    }
+
+}

src/main/java/net/raphimc/viaproxy/protocolhack/viaproxy/ViaBedrockTransferHolder.java

@@ -0,0 +1,51 @@
+/*
+ * 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.protocolhack.viaproxy;
+
+import io.netty.channel.Channel;
+
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class ViaBedrockTransferHolder {
+
+    private static final Map<InetAddress, InetSocketAddress> TEMP_REDIRECTS = new ConcurrentHashMap<>();
+
+    public static void addTempRedirect(final Channel channel, final InetSocketAddress redirect) {
+        TEMP_REDIRECTS.put(getChannelAddress(channel), redirect);
+    }
+
+    public static InetSocketAddress removeTempRedirect(final Channel channel) {
+        return TEMP_REDIRECTS.remove(getChannelAddress(channel));
+    }
+
+    public static boolean hasTempRedirect(final Channel channel) {
+        return TEMP_REDIRECTS.containsKey(getChannelAddress(channel));
+    }
+
+    public static InetSocketAddress getTempRedirect(final Channel channel) {
+        return TEMP_REDIRECTS.get(getChannelAddress(channel));
+    }
+
+    private static InetAddress getChannelAddress(final Channel channel) {
+        return ((InetSocketAddress) channel.remoteAddress()).getAddress();
+    }
+
+}

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

@@ -44,6 +44,7 @@ import net.raphimc.viaproxy.plugins.PluginManager;
 import net.raphimc.viaproxy.plugins.events.PreConnectEvent;
 import net.raphimc.viaproxy.plugins.events.Proxy2ServerHandlerCreationEvent;
 import net.raphimc.viaproxy.plugins.events.ResolveSrvEvent;
+import net.raphimc.viaproxy.protocolhack.viaproxy.ViaBedrockTransferHolder;
 import net.raphimc.viaproxy.proxy.LoginState;
 import net.raphimc.viaproxy.proxy.external_interface.AuthLibServices;
 import net.raphimc.viaproxy.proxy.external_interface.ExternalInterface;
@@ -76,13 +77,9 @@ import java.util.regex.Pattern;
 
 public class Client2ProxyHandler extends SimpleChannelInboundHandler<IPacket> {
 
-    private static final KeyPair KEY_PAIR;
+    private static final KeyPair KEY_PAIR = CryptUtil.generateKeyPair();
     private static final Random RANDOM = new Random();
 
-    static {
-        KEY_PAIR = CryptUtil.generateKeyPair();
-    }
-
     private ProxyConnection proxyConnection;
     private LoginState loginState = LoginState.FIRST_PACKET;
 
@@ -227,6 +224,12 @@ public class Client2ProxyHandler extends SimpleChannelInboundHandler<IPacket> {
             }
         }
 
+        if (serverVersion.equals(VersionEnum.bedrockLatest) && packet.intendedState == ConnectionState.LOGIN && ViaBedrockTransferHolder.hasTempRedirect(this.proxyConnection.getC2P())) {
+            final InetSocketAddress newAddress = ViaBedrockTransferHolder.removeTempRedirect(this.proxyConnection.getC2P());
+            connectIP = newAddress.getHostString();
+            connectPort = newAddress.getPort();
+        }
+
         final ResolveSrvEvent resolveSrvEvent = PluginManager.EVENT_MANAGER.call(new ResolveSrvEvent(serverVersion, connectIP, connectPort));
         connectIP = resolveSrvEvent.getHost();
         connectPort = resolveSrvEvent.getPort();