liminix/modules/bridge/primary.nix

{
  liminix
, ifwait
, lib
}:
{ ifname, macAddressFromInterface ? null, untagged } :
let
  inherit (liminix.services) oneshot;
  inherit (lib) optional optionalString;
  # This enables vlan_filtering if we do make use of it.
  extra = if untagged.enable then " vlan_filtering 1 vlan_default_pvid ${toString untagged.default-pvid}" else "";
in oneshot rec {
  name = "${ifname}.link";
  up = ''
    ${if macAddressFromInterface == null then
      "ip link add name ${ifname} type bridge${extra}"
      else
      "ip link add name ${ifname} address $(output ${macAddressFromInterface} ether) type bridge${extra}"}

      ${optionalString untagged.enable 
        "bridge vlan add vid ${toString untagged.pvid} dev ${ifname} pvid untagged self"}

      (in_outputs ${name}
        echo ${ifname} > ifname
        cat /sys/class/net/${ifname}/address > ether
      )
  '';
  down = "ip link delete ${ifname}";

  dependencies = optional (macAddressFromInterface != null) macAddressFromInterface;
}