# The home gateway that replaces antigua's routing role (ported from antigua's
# hand-written networkd/pppd/dnsmasq/WireGuard configuration).
#
#   ISP -- switch port --+-- enp2s0 (untagged)  LAN 192.168.168.0/24 (+ ULA, + delegated /64)
#                        +-- enp2s0.1001        PPPoE session: IPv4 and IPv6 (IPv6CP)
#
# Secrets are NOT in this repository. Put them in the directory handed to
# `router-install --secrets`; it lands in /var/lib/router on the box:
#
#   pppoe-password             the PPPoE password (from the ISP)
#   cloudflare-ddns-token      Cloudflare API token for ddclient
#   wireguard/freifunk.key     private keys (the ones antigua uses today keep the
#   wireguard/family.key       peers working without any change on their side;
#   wireguard/family.psk       never run both boxes with the same keys at once)
#   wireguard/mobile-clients.key
#   wireguard/mobile-clients.psk
#
# Before installing: fill in the PPPoE username below.
{ config, lib, ... }:
let
  secrets = "/var/lib/router";
  k8s = {
    v4 = "10.43.162.50";
    v6 = "fd32:66ac:e01f::f294";
  };
in
{
  imports = [ ../../modules/installer/layout.nix ];

  networking.hostName = "gateway";
  time.timeZone = "Europe/Berlin";
  system.stateVersion = "26.11";

  users.users.root.openssh.authorizedKeys.keys = [
    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHqyMLgAhEdnrRrd2CeYbphGDMPq/cBDjFJ4q4ItZusn nils@Nilss-Mac-mini.mch.stinnesbeck.com"
    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBFxbNNk87tvMxruuKvrryK7iAdf4xgS4xFqjKejNAI6 nils@nixtop"
  ];

  router = {
    enable = true;

    wan = {
      interface = "enp2s0";
      ipv4 = {
        type = "pppoe";
        pppoe = {
          vlan = 1001;
          # From antigua's networking.nix (pppd `user`); kept out of this file.
          username = "CHANGE-ME";
          passwordFile = "${secrets}/pppoe-password";
        };
      };
      # IPv6 runs inside the PPP session, with one delegated /64.
      ipv6 = {
        enable = true;
        transport = "ppp";
      };
    };

    lans.lan = {
      interface = "enp2s0";
      internet = true;
      ipv4.address = "192.168.168.254";
      ipv6 = {
        pd = true;
        address = "fd2c:cdef:cde9::1/64";
      };
      dhcp = {
        pool = {
          start = "192.168.168.100";
          end = "192.168.168.200";
        };
        reservations.truenas = {
          mac = "a8:a1:59:0b:4b:97";
          address = "192.168.168.251";
        };
      };
    };

    dns = {
      domain = "mch.stinnesbeck.com";
      forwarders = [
        "1.1.1.1"
        "2606:4700:4700::1111"
      ];
      hosts = {
        gateway = [ "192.168.168.254" ];
        "photos.stinnesbeck.com" = [
          k8s.v4
          k8s.v6
        ];
        "git.stinnesbeck.com" = [
          k8s.v4
          k8s.v6
        ];
      };
      overrides."k8s.stinnesbeck.com" = [
        k8s.v4
        k8s.v6
      ];
      forwardZones."tdf.stinnesbeck.com" = [ "10.1.0.254" ];
    };

    wireguard = {
      # Provider-style dial-out: only the treasure-maps.com hosts go through
      # it (antigua accepts 0.0.0.0/0 but routes just these), masqueraded. The
      # kill switch keeps them from leaking out of the WAN if the tunnel is down.
      freifunk = {
        privateKeyFile = "${secrets}/wireguard/freifunk.key";
        zone = "freifunk";
        masquerade = true;
        addresses = [
          "10.255.1.8/32"
          "fd80:3ea2:e399:203a::8/128"
        ];
        peers.supernode = {
          publicKey = "5B/YTaDPVWVApUyHshJp899iXXlBy8rBqJUpYvKo+1s=";
          endpoint = "5.9.220.114:42001";
          persistentKeepalive = 15;
          allowedIPs = [
            "185.90.196.65/32"
            "185.90.196.97/32"
            "185.90.196.129/32"
          ];
        };
      };

      # Site-to-site with Troisdorf; no transfer network. The site may use the
      # router (SSH, DNS), and the router reaches it from its LAN addresses.
      family = {
        privateKeyFile = "${secrets}/wireguard/family.key";
        listenPort = 36432;
        zone = "family";
        allowManagement = true;
        dns = true;
        sourceAddresses = [
          "192.168.168.254"
          "fd2c:cdef:cde9::1"
        ];
        peers.troisdorf = {
          publicKey = "BsQODhcHnEN4tXn60t72iejZvgYvVNt5BDVK+69+RgM=";
          endpoint = "fw-tdf.stinnesbeck.com:36432";
          persistentKeepalive = 25;
          presharedKeyFile = "${secrets}/wireguard/family.psk";
          allowedIPs = [
            "10.1.0.0/24"
            "fd73:f65e:6b64::/48"
          ];
        };
      };

      # Road warrior.
      mobile = {
        privateKeyFile = "${secrets}/wireguard/mobile-clients.key";
        listenPort = 36433;
        zone = "mobile";
        allowManagement = true;
        dns = true;
        peers.laptop = {
          publicKey = "Jts5u8zIs28v6RIEYCCufDDiWXf+gbElT63wUFWQxX4=";
          persistentKeepalive = 25;
          presharedKeyFile = "${secrets}/wireguard/mobile-clients.psk";
          allowedIPs = [ "10.2.0.2/32" ];
        };
      };
    };

    # antigua trusted these interfaces completely and forwarded between all of
    # them. Here it is spelled out: the LAN and Troisdorf reach each other, the
    # LAN reaches the freifunk hosts, road warriors reach the LAN. Nothing
    # initiates from freifunk.
    firewall.rules = [
      {
        from = "lan";
        to = "family";
      }
      {
        from = "family";
        to = "lan";
      }
      {
        from = "lan";
        to = "freifunk";
      }
      {
        from = "mobile";
        to = "lan";
      }
    ];
  };

  # Dynamic DNS from the PPP device's addresses.
  services.ddclient = {
    enable = true;
    interval = "5min";
    protocol = "cloudflare";
    username = "token";
    passwordFile = "${secrets}/cloudflare-ddns-token";
    zone = "stinnesbeck.com";
    domains = [
      "fw-mch.stinnesbeck.com"
      "car.k8s.stinnesbeck.com"
      "photos.stinnesbeck.com"
      "git.stinnesbeck.com"
      "link.stinnesbeck.com"
      "pw.k8s.stinnesbeck.com"
    ];
    usev4 = "ifv4, ifv4=${config.router.wan.ipv4.interface}";
    usev6 = "ifv6, ifv6=${config.router.wan.ipv4.interface}";
    ssl = true;
    verbose = true;
  };
}