Add Forge mod list support

proxy/src/main/java/com/velocitypowered/proxy/connection/client/ClientPlaySessionHandler.java

@@ -1,10 +1,9 @@
 package com.velocitypowered.proxy.connection.client;
 
-import com.velocitypowered.api.event.connection.DisconnectEvent;
 import com.velocitypowered.api.event.connection.PluginMessageEvent;
 import com.velocitypowered.api.event.player.PlayerChatEvent;
 import com.velocitypowered.api.proxy.messages.ChannelIdentifier;
-import com.velocitypowered.api.proxy.player.TabList;
+import com.velocitypowered.api.util.ModInfo;
 import com.velocitypowered.proxy.VelocityServer;
 import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
 import com.velocitypowered.proxy.connection.VelocityConstants;
@@ -13,7 +12,6 @@ import com.velocitypowered.proxy.protocol.MinecraftPacket;
 import com.velocitypowered.proxy.protocol.ProtocolConstants;
 import com.velocitypowered.proxy.protocol.packet.*;
 import com.velocitypowered.proxy.protocol.util.PluginMessageUtil;
-import com.velocitypowered.proxy.tablist.VelocityTabList;
 import com.velocitypowered.proxy.util.ThrowableUtils;
 import io.netty.buffer.ByteBuf;
 import net.kyori.text.TextComponent;
@@ -147,6 +145,11 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
             player.getConnectedServer().getConnection().write(PluginMessageUtil.rewriteMCBrand(packet));
         } else if (player.getConnectedServer().isLegacyForge() && !player.getConnectedServer().hasCompletedJoin()) {
             if (packet.getChannel().equals(VelocityConstants.FORGE_LEGACY_HANDSHAKE_CHANNEL)) {
+                List<ModInfo.Mod> mods = PluginMessageUtil.readModList(packet);
+                if (!mods.isEmpty()) {
+                    player.setModInfo(new ModInfo("FML", mods));
+                }
+                
                 // Always forward the FML handshake to the remote server.
                 player.getConnectedServer().getConnection().write(packet);
             } else {

proxy/src/main/java/com/velocitypowered/proxy/connection/client/ConnectedPlayer.java

@@ -4,6 +4,7 @@ import com.google.common.base.Preconditions;
 import com.google.gson.JsonObject;
 import com.velocitypowered.api.event.connection.DisconnectEvent;
 import com.velocitypowered.api.event.player.KickedFromServerEvent;
+import com.velocitypowered.api.event.player.PlayerModInfoEvent;
 import com.velocitypowered.api.event.player.PlayerSettingsChangedEvent;
 import com.velocitypowered.api.event.player.ServerPreConnectEvent;
 import com.velocitypowered.api.permission.PermissionFunction;
@@ -16,8 +17,8 @@ import com.velocitypowered.api.proxy.messages.ChannelIdentifier;
 import com.velocitypowered.api.proxy.player.PlayerSettings;
 import com.velocitypowered.api.proxy.server.RegisteredServer;
 import com.velocitypowered.api.util.GameProfile;
-import com.velocitypowered.api.proxy.player.TabList;
 import com.velocitypowered.api.util.MessagePosition;
+import com.velocitypowered.api.util.ModInfo;
 import com.velocitypowered.api.util.title.TextTitle;
 import com.velocitypowered.api.util.title.Title;
 import com.velocitypowered.api.util.title.Titles;
@@ -31,9 +32,6 @@ import com.velocitypowered.proxy.connection.util.ConnectionRequestResults;
 import com.velocitypowered.proxy.protocol.ProtocolConstants;
 import com.velocitypowered.proxy.protocol.packet.*;
 import com.velocitypowered.proxy.server.VelocityRegisteredServer;
-import com.velocitypowered.proxy.protocol.packet.Chat;
-import com.velocitypowered.proxy.protocol.packet.ClientSettings;
-import com.velocitypowered.proxy.protocol.packet.PluginMessage;
 import com.velocitypowered.proxy.tablist.VelocityTabList;
 import com.velocitypowered.proxy.util.ThrowableUtils;
 import net.kyori.text.Component;
@@ -69,6 +67,7 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
     private VelocityServerConnection connectedServer;
     private VelocityServerConnection connectionInFlight;
     private PlayerSettings settings;
+    private ModInfo modInfo;
     private final VelocityTabList tabList;
     private final VelocityServer server;
     
@@ -120,7 +119,16 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
         this.settings = new ClientSettingsWrapper(settings);
         server.getEventManager().fireAndForget(new PlayerSettingsChangedEvent(this, this.settings));
     }
-
+    
+    public Optional<ModInfo> getModInfo() {
+        return Optional.ofNullable(modInfo);
+    }
+    
+    void setModInfo(ModInfo modInfo) {
+        this.modInfo = modInfo;
+        server.getEventManager().fireAndForget(new PlayerModInfoEvent(this, this.modInfo));
+    }
+    
     @Override
     public InetSocketAddress getRemoteAddress() {
         return (InetSocketAddress) connection.getRemoteAddress();

proxy/src/main/java/com/velocitypowered/proxy/connection/client/StatusSessionHandler.java

@@ -4,6 +4,7 @@ import com.google.common.collect.ImmutableList;
 import com.velocitypowered.api.event.proxy.ProxyPingEvent;
 import com.velocitypowered.api.proxy.InboundConnection;
 import com.velocitypowered.api.proxy.server.ServerPing;
+import com.velocitypowered.api.util.ModInfo;
 import com.velocitypowered.proxy.VelocityServer;
 import com.velocitypowered.proxy.config.VelocityConfiguration;
 import com.velocitypowered.proxy.connection.MinecraftConnection;
@@ -42,7 +43,7 @@ public class StatusSessionHandler implements MinecraftSessionHandler {
                 new ServerPing.Players(server.getPlayerCount(), configuration.getShowMaxPlayers(), ImmutableList.of()),
                 configuration.getMotdComponent(),
                 configuration.getFavicon().orElse(null),
-                configuration.isAnnounceForge() ? ServerPing.ModInfo.DEFAULT : null
+                configuration.isAnnounceForge() ? ModInfo.DEFAULT : null
         );
 
         ProxyPingEvent event = new ProxyPingEvent(inboundWrapper, initialPing);

proxy/src/main/java/com/velocitypowered/proxy/protocol/util/PluginMessageUtil.java

@@ -2,6 +2,8 @@ package com.velocitypowered.proxy.protocol.util;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Lists;
+import com.velocitypowered.api.util.ModInfo;
 import com.velocitypowered.proxy.protocol.ProtocolConstants;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import com.velocitypowered.proxy.protocol.packet.PluginMessage;
@@ -76,4 +78,23 @@ public class PluginMessageUtil {
         newMsg.setData(rewrittenData);
         return newMsg;
     }
+    
+    public static List<ModInfo.Mod> readModList(PluginMessage message) {
+        List<ModInfo.Mod> mods = Lists.newArrayList();
+        
+        ByteBuf byteBuf = Unpooled.wrappedBuffer(message.getData());
+        byte discriminator = byteBuf.readByte();
+        
+        if (discriminator == 2) {
+            int modCount = ProtocolUtils.readVarInt(byteBuf);
+            
+            for (int index = 0; index < modCount; index++) {
+                String id = ProtocolUtils.readString(byteBuf);
+                String version = ProtocolUtils.readString(byteBuf);
+                mods.add(new ModInfo.Mod(id, version));
+            }
+        }
+        
+        return ImmutableList.copyOf(mods);
+    }
 }