KGB 🚀

KCool Geo Blocker 🌍

KGB is a Go application that manages IP filtering based on country codes using nftables. It allows you to configure allowed or denied countries, gather metrics on the number of packets and bytes filtered, and expose metrics for Prometheus monitoring. 📊

Features ✨

• Country-based IP Filtering: Easily allow or block IP addresses from specific countries. 🚫
• Prometheus Metrics: Collect and expose metrics about the number of packets and bytes filtered, including the last update time and the status of blocked and allowed countries. 📈
• Periodic Updates: Automatically update the filtering rules at specified intervals. ⏲️
• Dynamic Configuration: Change the allowed or denied countries at runtime using command-line flags. ⚙️

Requirements 🛠️

• Go (version 1.16 or newer)
• nftables installed on your system
• Prometheus (if you wish to collect metrics)

Installation 🛠️

For any linux distro download binary

wget https://github.com/Split174/KGB/releases/download/0.0.1/kgb
chmod +x kgb

For Nixos

1. In configuration.nix download tarball with kgb

nixpkgs.config = {
   packageOverrides = pkgs: {
      kgbnur = import (builtins.fetchTarball "https://github.com/Split174/nur/archive/master.tar.gz") {
         inherit pkgs;
      };
   };
};

2. Add package

environment.systemPackages = with pkgs; [
   kgbnur.nur
];

3. (Optional) Run kgb as systemd service

systemd.services.kgb = {
   description = "KGB service with specific country allowlist";

   after = ["network.target"];
   wantedBy = ["multi-user.target"];

   path = with pkgs; [
      nftables
      wget
   ];

   serviceConfig = {
      ExecStart = "${pkgs.kgbnur.kgb}/bin/kgb --allow ru,nl";

      User = "root";

      Type = "simple";

      Restart = "always";
      RestartSec = "30s";
   };
};

Usage 🖥️

You can run the application with the following command-line flags:

• --allow: Comma-separated list of country codes to allow. ✅
• --deny: Comma-separated list of country codes to block. ❌
• --port: Port number for the Prometheus metrics endpoint (default is 9000).
• --timer: Update interval in minutes (default is 60 minutes).

Examples 📚

To allow traffic from Russia and Netherlands:

kgb --allow ru,nl

To deny traffic from China and South Korea:

kgb --deny cn,kr

Contributing 🤝

Contributions are welcome! Please feel free to submit issues or pull requests.

1. Fork the repository.
2. Create your feature branch (git checkout -b feature/AmazingFeature).
3. Commit your changes (git commit -m 'Add some amazing feature').
4. Push to the branch (git push origin feature/AmazingFeature).
5. Open a pull request.