hosts/losurdo/networking/wireguard/intranet.nix

   1 { pkgs, lib, config, inputs, ... }:
   2 let
   3   inherit (config.boot) initrd;
   4   iface = "wg-intra";
   5   wg = config.networking.wireguard.interfaces.${iface};
   6   wg-intra-peers = import (inputs.julm-nix + "/nixos/profiles/wireguard/wg-intra/peers.nix");
   7   relay = wg-intra-peers.mermet;
   8 in
   9 {
  10 imports = [
  11   (inputs.julm-nix + "/nixos/profiles/wireguard/wg-intra.nix")
  12 ];
  13 networking.wireguard.${iface}.peers = {
  14   mermet.enable = true;
  15   oignon.enable = true;
  16   patate.enable = true;
  17   carotte.enable = true;
  18 };
  19 systemd.services."wireguard-${iface}" = {
  20   unitConfig.Upholds = [ "upnpc-${toString wg.listenPort}.service" ];
  21 };
  22 networking.nftables.ruleset = ''
  23   # Allow initiating connection to and from other peers
  24   add rule inet filter fw2net udp sport ${toString wg.listenPort} counter accept comment "WireGuard ${iface} output to peers"
  25   add rule inet filter net2fw udp dport ${toString wg.listenPort} counter accept comment "WireGuard ${iface} input from peers"
  26
  27   # Hook ${iface} into relevant chains
  28   add chain inet filter intra2fw
  29   #add rule  inet filter intra2fw counter accept
  30   add rule inet filter input  iifname "${iface}" jump intra2fw
  31   add rule inet filter input  iifname "${iface}" log level warn prefix "intra2fw: " counter drop
  32   add rule inet filter output oifname "${iface}" jump fw2intra
  33   add rule inet filter output oifname "${iface}" log level warn prefix "fw2intra: " counter drop
  34
  35   # ${iface} firewalling
  36   add chain inet filter fw2intra
  37   #add rule  inet filter fw2intra counter accept
  38   add rule inet filter fw2intra counter accept
  39   ${lib.concatMapStringsSep "\n" (ip: ''
  40     add rule inet filter intra2fw ip saddr ${ip} counter accept comment "relay"
  41   '') relay.ips}
  42
  43   add chain inet filter fwd-intra
  44   #add rule  inet filter fwd-intra counter accept
  45   add rule  inet filter forward iifname "${iface}" jump fwd-intra
  46 '';
  47 # Apparently required to get NAT reflection.
  48 services.upnpc.redirections = [
  49   { description = "WireGuard"; externalPort = wg.listenPort; protocol = "UDP"; duration = 30 * 60;
  50     service.requiredBy = [ "wireguard-${iface}.service" ];
  51     service.before     = [ "wireguard-${iface}.service" ];
  52   }
  53 ];
  54 boot.kernel.sysctl."net.ipv4.ip_forward" = 1;
  55
  56 # Open a wireguard tunnel to a relay
  57 # in case the host is hosted behind a NAT and has no SSH port forwarding.
  58 # This enables to send the disk password to the initrd, like that:
  59 # ssh -J mermet.sourcephile.fr root@losurdo.wg -p 2222
  60 boot.initrd.secrets."/root/initrd/${iface}.key" = "/root/initrd/${iface}.key";
  61 boot.initrd.kernelModules = [ "wireguard" ];
  62 boot.initrd.extraUtilsCommands = ''
  63   #copy_bin_and_libs ${pkgs.wireguard-tools}/bin/wg
  64   cp -fpdv ${pkgs.wireguard-tools}/bin/.wg-wrapped $out/bin/wg
  65 '';
  66 boot.initrd.network.postCommands = ''
  67   ip link add dev ${iface} type wireguard
  68   ${lib.concatMapStringsSep "\n" (ip: ''
  69     ip address add ${ip} dev ${iface}
  70   '') wg.ips}
  71   wg set ${iface} private-key /root/initrd/${iface}.key \
  72      listen-port ${toString wg.listenPort}
  73   ip link set up dev ${iface} mtu 1280
  74   wg set ${iface} peer ${relay.peer.publicKey} \
  75      endpoint ${relay.ipv4}:${toString relay.listenPort} \
  76      allowed-ips ${relay.ipv4}/32 \
  77      persistent-keepalive 5
  78   ip route replace ${relay.ipv4}/32 dev ${iface} table main
  79 '';
  80 boot.initrd.postMountCommands = lib.mkIf initrd.network.flushBeforeStage2 ''
  81   ip link del dev ${iface}
  82 '';
  83 }