nix-config-v2/modules/networking/core.nix

{
  config,
  lib,
  ...
}: let
  cfg = config.networking;
in {
  options.networking = {
    # Firewall Configuration
    firewall = {
      enable = lib.mkEnableOption {
        type = lib.types.bool;
        default = true;
        description = "Enable system firewall";
      };

      tcpPorts = {
        # Predefined, default common service ports
        ssh = {
          enable = lib.mkEnableOption {
            type = lib.types.bool;
            default = false;
            description = "Open SSH service port (22)";
          };
        };
        web = {
          enable = lib.mkEnableOption {
            type = lib.types.bool;
            default = false;
            description = "Open common web service ports (80, 443)";
          };
        };
        smtp = {
          enable = lib.mkEnableOption {
            type = lib.types.bool;
            default = false;
            description = "Open SMTP service ports (25, 465, 587)";
          };
        };
        imap = {
          enable = lib.mkEnableOption {
            type = lib.types.bool;
            default = false;
            description = "Open IMAP service ports (143, 993)";
          };
        };
        mysql = {
          enable = lib.mkEnableOption {
            type = lib.types.bool;
            default = false;
            description = "Open MySQL service port (3306)";
          };
        };
        mssql = {
          enable = lib.mkEnableOption {
            type = lib.types.bool;
            default = false;
            description = "Open Microsoft SQL Server service port (1433)";
          };
        };
        postgres = {
          enable = lib.mkEnableOption {
            type = lib.types.bool;
            default = false;
            description = "Open Postgres service port (5432)";
          };
        };
        allowedPorts = lib.mkOption {
          type = lib.types.listOf lib.types.port;
          default = [];
          description = "List of custom TCP ports to open";
        };
      };

      udpPorts = {
        dns = {
          enable = lib.mkEnableOption {
            type = lib.types.bool;
            default = false;
            description = "Open DNS service port (53)";
          };
        };
        ntp = {
          enable = lib.mkEnableOption {
            type = lib.types.bool;
            default = false;
            description = "Open NTP service port (123)";
          };
        };
        allowedPorts = lib.mkOption {
          type = lib.types.listOf lib.types.port;
          default = [];
          description = "List of custom UDP ports to open";
        };
      };
    };

    networkManager = {
      enable = lib.mkEnableOption {
        type = lib.types.bool;
        default = true;
        description = "Enable NetworkManager for network connection management";
      };

      extraPlugins = lib.mkOption {
        type = lib.types.listOf lib.types.package;
        default = [];
        description = "Additional NetworkManager plugins to install";
      };
    };
  };

  config = {
    networking.firewall = {
      enable = cfg.firewall.enable;

      allowedTCPPorts =
        (
          lib.optionals
          cfg.firewall.tcpPorts.ssh.enable [22]
          cfg.firewall.tcpPorts.web.enable [80 443]
          cfg.firewall.tcpPorts.smtp.enable [25 465 587]
          cfg.firewall.tcpPorts.imap.enable [143 993]
          cfg.firewall.tcpPorts.mysql.enable [3306]
          cfg.firewall.tcpPorts.mssql.enable [1433]
          cfg.firewall.tcpPorts.postgres.enable [5432]
        )
        ++ cfg.firewall.tcpPorts.allowedPorts;

      allowedUDPPorts =
        (
          lib.optionals
          cfg.firewall.udpPorts.dns.enable [53]
          cfg.firewall.udpPorts.ntp.enable [123]
        )
        ++ cfg.firewall.udpPorts.allowedPorts;
    };

    networking.networkmanager = {
      enable = lib.mkForce cfg.networkManager.enable;
      packages = cfg.networkManager.extraPlugins;
    };
  };
}