nixos-config/nixos/modules/services/enthalpy/clat.nix

85 lines
2.4 KiB
Nix

# Portions of this file are sourced from
# https://github.com/NickCao/flakes/blob/3b03efb676ea602575c916b2b8bc9d9cd13b0d85/nixos/mainframe/gravity.nix
{
config,
lib,
pkgs,
mylib,
...
}:
with lib;
let
inherit (mylib.network) cidr;
cfg = config.services.enthalpy;
in
{
options.services.enthalpy.clat = {
enable = mkEnableOption "464XLAT for IPv4 connectivity";
address = mkOption {
type = types.str;
default = cidr.host 2 cfg.prefix;
description = ''
IPv6 address used for 464XLAT as the mapped source address.
'';
};
segment = mkOption {
type = types.listOf types.str;
description = ''
SRv6 segments used for NAT64.
'';
};
};
config = mkIf (cfg.enable && cfg.clat.enable) {
systemd.services.enthalpy-clat = {
path = with pkgs; [
iproute2
tayga
];
preStart = ''
ip -6 route replace 64:ff9b::/96 from ${cfg.clat.address} encap seg6 mode encap \
segs ${concatStringsSep "," cfg.clat.segment} dev enthalpy mtu 1280
'';
script = ''
exec tayga --config ${pkgs.writeText "tayga.conf" ''
tun-device clat
prefix 64:ff9b::/96
ipv4-addr 192.0.0.1
map 192.0.0.2 ${cfg.clat.address}
''}
'';
postStart = ''
ip link set clat up
ip -4 addr add 192.0.0.2/32 dev clat
ip -6 route add ${cfg.clat.address} dev clat
ip -4 route add 0.0.0.0/0 dev clat src 192.0.0.2
'';
preStop = ''
ip -6 route del 64:ff9b::/96 from ${cfg.clat.address} encap seg6 mode encap \
segs ${concatStringsSep "," cfg.clat.segment} dev enthalpy mtu 1280
'';
serviceConfig = {
Type = "forking";
Restart = "on-failure";
RestartSec = 5;
DynamicUser = true;
RuntimeDirectory = "enthalpy";
CapabilityBoundingSet = [ "CAP_NET_ADMIN" ];
AmbientCapabilities = [ "CAP_NET_ADMIN" ];
ProtectSystem = "full";
ProtectHome = "yes";
ProtectKernelTunables = true;
ProtectControlGroups = true;
PrivateTmp = true;
SystemCallFilter = "~@cpu-emulation @debug @keyring @module @mount @obsolete @raw-io";
MemoryDenyWriteExecute = "yes";
};
wants = [ "network.target" ];
after = [ "network.target" ];
wantedBy = [ "multi-user.target" ];
};
services.enthalpy.services.enthalpy-clat = { };
};
}