hosts/losurdo/networking/wireguard/intranet.nix

   1 { pkgs, lib, config, inputs, ... }:
   2 let
   3   inherit (config.boot) initrd;
   4   netIface = "enp5s0";
   5   wgIface = "wg-intra";
   6   wg = config.networking.wireguard.interfaces.${wgIface};
   7   wg-intra-peers = import (inputs.julm-nix + "/nixos/profiles/wireguard/wg-intra/peers.nix");
   8   relay = wg-intra-peers.mermet;
   9 in
  10 {
  11 imports = [
  12   (inputs.julm-nix + "/nixos/profiles/wireguard/wg-intra.nix")
  13 ];
  14 networking.wireguard.${wgIface}.peers = {
  15   mermet.enable = true;
  16   oignon.enable = true;
  17   patate.enable = true;
  18   carotte.enable = true;
  19   aubergine.enable = true;
  20 };
  21 systemd.services."wireguard-${wgIface}" = {
  22   unitConfig.Upholds = [ "upnpc-${toString wg.listenPort}.service" ];
  23 };
  24 networking.nftables.ruleset = ''
  25   table inet filter {
  26     chain input-intra {
  27       tcp dport ssh counter accept comment "SSH"
  28       udp dport 60000-61000 counter accept comment "Mosh"
  29     }
  30     chain output-intra {
  31       tcp dport { ssh, 2222 } counter accept comment "SSH"
  32       udp dport 60001-60010 counter accept comment "Mosh"
  33       tcp dport { http, https } counter accept comment "HTTP"
  34       tcp dport git counter accept comment "Git"
  35     }
  36   }
  37   table inet nat {
  38     chain postrouting {
  39       iifname ${wgIface} oifname netIface masquerade
  40     }
  41   }
  42 '';
  43 # Apparently required to get NAT reflection.
  44 services.upnpc.redirections = [
  45   { description = "WireGuard"; externalPort = wg.listenPort; protocol = "UDP"; duration = 30 * 60;
  46     service.requiredBy = [ "wireguard-${wgIface}.service" ];
  47     service.before     = [ "wireguard-${wgIface}.service" ];
  48   }
  49 ];
  50 boot.kernel.sysctl."net.ipv4.ip_forward" = 1;
  51
  52 # Open a wireguard tunnel to a relay
  53 # in case the host is hosted behind a NAT and has no SSH port forwarding.
  54 # This enables to send the disk password to the initrd, like that:
  55 # ssh -J mermet.sourcephile.fr root@losurdo.wg -p 2222
  56 boot.initrd.secrets."/root/initrd/${wgIface}.key" = "/root/initrd/${wgIface}.key";
  57 boot.initrd.kernelModules = [ "wireguard" ];
  58 boot.initrd.extraUtilsCommands = ''
  59   #copy_bin_and_libs ${pkgs.wireguard-tools}/bin/wg
  60   cp -fpdv ${pkgs.wireguard-tools}/bin/.wg-wrapped $out/bin/wg
  61 '';
  62 boot.initrd.network.postCommands = ''
  63   ip link add dev ${wgIface} type wireguard
  64   ${lib.concatMapStringsSep "\n" (ip: ''
  65     ip address add ${ip} dev ${wgIface}
  66   '') wg.ips}
  67   wg set ${wgIface} private-key /root/initrd/${wgIface}.key \
  68      listen-port ${toString wg.listenPort}
  69   ip link set up dev ${wgIface} mtu 1280
  70   wg set ${wgIface} peer ${relay.peer.publicKey} \
  71      endpoint ${relay.ipv4}:${toString relay.listenPort} \
  72      allowed-ips ${relay.ipv4}/32 \
  73      persistent-keepalive 5
  74   ip route replace ${relay.ipv4}/32 dev ${wgIface} table main
  75 '';
  76 boot.initrd.postMountCommands = lib.mkIf initrd.network.flushBeforeStage2 ''
  77   ip link del dev ${wgIface}
  78 '';
  79 }