grasskcpper-v2

A kcp library built for a certain cute game

Modification

• 4.6+ protocol support
• Kcp version detection support
• Proxy Protocol v2 support - Extract original client IP addresses when running behind proxy servers like FRP

How to add it to your project

Add the AnimeGameServers maven repo to your build file:

repositories {
    ...
    maven {
        name = "ags-mvn-Releases"
        url = uri("https://mvn.animegameservers.org/releases")
    }
}

Then add this to your dependencies in the gradle build file:

implementation "org.anime_game_servers:grasskcpper:0.1"

Proxy Protocol v2 Integration

This library now supports Proxy Protocol v2, enabling extraction of original client IP addresses when running behind proxy servers like FRP (Fast Reverse Proxy).

Quick Setup

// Enable proxy protocol support
ChannelConfig config = new ChannelConfig();
config.setProxyProtocolV2Enabled(true);

// Your KCP listener will receive the original client IP
KcpListener listener = new KcpListener() {
    @Override
    public void onConnected(Ukcp ukcp) {
        // ukcp.user().getRemoteAddress() now contains the ORIGINAL client IP
        InetSocketAddress originalClient = ukcp.user().getRemoteAddress();
        System.out.println("Client connected from: " + originalClient.getAddress().getHostAddress());
    }
    // ... other methods
};

KcpServer server = new KcpServer();
server.init(listener, config, new InetSocketAddress(9999));

Features

• Automatic Header Detection: Gracefully handles both proxied and direct connections
• IPv4 and IPv6 Support: Works with both address families
• Clean Payload Processing: Strips proxy headers and processes original game data
• FRP Compatible: Tested with Fast Reverse Proxy configurations
• Zero Configuration Fallback: Works normally when no proxy headers are present

For detailed configuration and troubleshooting, see PROXY_PROTOCOL_INTEGRATION.md.

Credits

Anime game changes: Simplxss

Version 4.6+ Changes: OcenWang-GI Commit

Original library: https://github.com/l42111996/java-Kcp