os/modules/core/networking.nix

{
  flake,
  config,
  pkgs,
  lib,
  ...
}: {
  # disable NetworkManager and systemd-networkd -wait-online by default
  systemd.services.NetworkManager-wait-online.enable = lib.mkDefault false;
  systemd.services.systemd-networkd-wait-online.enable = lib.mkDefault false;

  networking.hosts = {
    "128.140.109.213" = ["vpn.b12f.io"];
    "2a01:4f8:c2c:b60::" = ["vpn.b12f.io"];
  };

  networking.networkmanager = {
    # Enable networkmanager. REMEMBER to add yourself to group in order to use nm related stuff.
    enable = lib.mkDefault true;
    wifi.backend = lib.mkDefault "iwd";
  };

  networking.firewall.enable = true;
  networking.nftables.enable = true;

  services.resolved = {
    enable = lib.mkDefault true;
    fallbackDns = [
      "193.110.81.0#dns0.eu"
      "2a0f:fc80::#dns0.eu"
      "185.253.5.0#dns0.eu"
      "2a0f:fc81::#dns0.eu"
    ];
    dnssec = "false";
    extraConfig = ''
      DNSOverTLS=opportunistic
    '';
  };

  # Don't expose SSH via public interfaces
  networking.firewall.interfaces.wg-private.allowedTCPPorts = [22];

  # For rage encryption, all hosts need a ssh key pair
  services.openssh = {
    enable = true;
    allowSFTP = lib.mkDefault false;

    openFirewall = lib.mkDefault false;

    settings.PasswordAuthentication = lib.mkDefault false;
    settings.KbdInteractiveAuthentication = false;

    extraConfig = ''
      AllowTcpForwarding yes
      X11Forwarding no
      AllowAgentForwarding no
      AllowStreamLocalForwarding no
      AuthenticationMethods publickey
    '';
  };
}