nixos/profiles/wireguard/wg-intra.nix

   1 { inputs, lib, config, hostName, ... }:
   2 let
   3   wgIface = "wg-intra";
   4   peers = import wg-intra/peers.nix;
   5   wg = config.networking.wireguard.interfaces.${wgIface};
   6 in
   7 {
   8   # Each peer select the other peers allowed to connect to it
   9   options.networking.wireguard.${wgIface}.peers =
  10     lib.genAttrs (lib.attrNames peers) (_peerName: {
  11       enable = lib.mkEnableOption "this peer";
  12     });
  13   config = {
  14     systemd.services."wireguard-${wgIface}".serviceConfig.LoadCredentialEncrypted =
  15       [ "privateKey:${inputs.self}/hosts/${hostName}/wireguard/${wgIface}/privateKey.cred" ];
  16     networking.wireguard.interfaces.${wgIface} = lib.recursiveUpdate
  17       (removeAttrs peers.${hostName} [ "ipv4" "persistentKeepalive" "peer" ])
  18       {
  19         peers =
  20           lib.mapAttrsToList
  21             (_peerName: peer:
  22               lib.recursiveUpdate
  23                 {
  24                   persistentKeepalive =
  25                     peer.persistentKeepalive # Useful if this peer is behind a NAT
  26                       or peers.${hostName}.persistentKeepalive # Useful if this host is behind a NAT
  27                       or null;
  28                 }
  29                 peer.peer)
  30             (removeAttrs
  31               (lib.filterAttrs (peerName: _: config.networking.wireguard.${wgIface}.peers.${peerName}.enable) peers)
  32               [ hostName ]);
  33         privateKeyFile = "\$CREDENTIALS_DIRECTORY/privateKey";
  34
  35         # Set the MTU to a minimum
  36         # (IPv4 requires at least 68 but it's 1280 for IPv6).
  37         # This prevents connections to stall on huge packets,
  38         # or delaying their initializing due to TCP PMTU probing.
  39         postSetup = ''
  40           ip link set dev ${wgIface} mtu 1280
  41         '';
  42       };
  43     networking.hosts = lib.mkMerge [
  44       (lib.mapAttrs'
  45         (hostName: host:
  46           lib.nameValuePair host.ipv4 [ "${hostName}.wg" ])
  47         peers)
  48       {
  49         "${peers.losurdo.ipv4}" = [
  50           "nix-extracache.losurdo.wg"
  51           "nix-localcache.losurdo.wg"
  52           "sftp.losurdo.wg"
  53         ];
  54       }
  55     ];
  56     networking.firewall.extraCommands = lib.optionalString (wg.listenPort != null) ''
  57       ip46tables -A nixos-fw -i any -p udp -m udp --dport ${toString wg.listenPort} -j ACCEPT
  58     '';
  59
  60     networking.nftables.ruleset = lib.optionalString (wg.listenPort != null) ''
  61       table inet filter {
  62         chain input-lan {
  63           udp dport ${toString wg.listenPort} counter accept \
  64             comment "Wireguard ${wgIface} input from peers"
  65         }
  66         chain input-net {
  67           udp dport ${toString wg.listenPort} counter accept \
  68             comment "Wireguard ${wgIface} input from peers"
  69         }
  70         chain input-intra {
  71           ${lib.optionalString (peers.${hostName}.peer.endpointsUpdater.enable or false) ''
  72             tcp dport ${toString peers.${hostName}.listenPort} ip daddr ${peers.${hostName}.ipv4} counter accept comment "Wireguard ${wgIface} from peers to endpointUpdater"
  73             ''
  74           }
  75         }
  76         chain input {
  77           iifname ${wgIface} jump input-intra
  78           iifname ${wgIface} log level warn prefix "input-intra: " counter drop
  79         }
  80
  81         chain output-lan {
  82           udp sport ${toString wg.listenPort} counter accept \
  83             comment "Wireguard ${wgIface} output to peers"
  84         }
  85         chain output-net {
  86           udp sport ${toString wg.listenPort} counter accept \
  87             comment "Wireguard ${wgIface} output to peers"
  88         }
  89         chain output-intra {
  90           ${lib.concatStringsSep "\n"
  91               (lib.mapAttrsToList (peerName: peer: ''
  92                 ip daddr ${peer.ipv4} \
  93                   tcp dport ${toString peer.listenPort} \
  94                   counter accept \
  95                   comment "Wireguard ${wgIface} to endpointUpdater ${peerName}"
  96                 '')
  97                 (lib.filterAttrs (peerName: peer:
  98                   config.networking.wireguard.${wgIface}.peers.${peerName}.enable &&
  99                   (peers.${peerName}.peer.endpointsUpdater.enable or false))
 100                   peers))
 101           }
 102         }
 103         chain output {
 104           oifname ${wgIface} jump output-intra
 105           oifname ${wgIface} log level warn prefix "output-intra: " counter drop
 106         }
 107       }
 108     '';
 109
 110     services.fail2ban.ignoreIP = lib.concatMap
 111       (host: host.peer.allowedIPs)
 112       (lib.attrValues peers);
 113     networking.networkmanager.unmanaged = [ wgIface ];
 114   };
 115 }