{ config, lib, pkgs, ... }: with lib; let cfg = config.networking.wg-quick; kernel = config.boot.kernelPackages; # interface options interfaceOpts = { ... }: { options = { address = mkOption { example = [ "192.168.2.1/24" ]; default = []; type = with types; listOf str; description = "The IP addresses of the interface."; }; dns = mkOption { example = [ "192.168.2.2" ]; default = []; type = with types; listOf str; description = "The IP addresses of DNS servers to configure."; }; privateKey = mkOption { example = "yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk="; type = with types; nullOr str; default = null; description = '' Base64 private key generated by wg genkey. Warning: Consider using privateKeyFile instead if you do not want to store the key in the world-readable Nix store. ''; }; privateKeyFile = mkOption { example = "/private/wireguard_key"; type = with types; nullOr str; default = null; description = '' Private key file as generated by wg genkey. ''; }; listenPort = mkOption { default = null; type = with types; nullOr int; example = 51820; description = '' 16-bit port for listening. Optional; if not specified, automatically generated based on interface name. ''; }; preUp = mkOption { example = literalExpression ''"''${pkgs.iproute2}/bin/ip netns add foo"''; default = ""; type = with types; coercedTo (listOf str) (concatStringsSep "\n") lines; description = '' Commands called at the start of the interface setup. ''; }; preDown = mkOption { example = literalExpression ''"''${pkgs.iproute2}/bin/ip netns del foo"''; default = ""; type = with types; coercedTo (listOf str) (concatStringsSep "\n") lines; description = '' Command called before the interface is taken down. ''; }; postUp = mkOption { example = literalExpression ''"''${pkgs.iproute2}/bin/ip netns add foo"''; default = ""; type = with types; coercedTo (listOf str) (concatStringsSep "\n") lines; description = '' Commands called after the interface setup. ''; }; postDown = mkOption { example = literalExpression ''"''${pkgs.iproute2}/bin/ip netns del foo"''; default = ""; type = with types; coercedTo (listOf str) (concatStringsSep "\n") lines; description = '' Command called after the interface is taken down. ''; }; table = mkOption { example = "main"; default = null; type = with types; nullOr str; description = '' The kernel routing table to add this interface's associated routes to. Setting this is useful for e.g. policy routing ("ip rule") or virtual routing and forwarding ("ip vrf"). Both numeric table IDs and table names (/etc/rt_tables) can be used. Defaults to "main". ''; }; mtu = mkOption { example = 1248; default = null; type = with types; nullOr int; description = '' If not specified, the MTU is automatically determined from the endpoint addresses or the system default route, which is usually a sane choice. However, to manually specify an MTU to override this automatic discovery, this value may be specified explicitly. ''; }; peers = mkOption { default = []; description = "Peers linked to the interface."; type = with types; listOf (submodule peerOpts); }; }; }; # peer options peerOpts = { options = { publicKey = mkOption { example = "xTIBA5rboUvnH4htodjb6e697QjLERt1NAB4mZqp8Dg="; type = types.str; description = "The base64 public key to the peer."; }; presharedKey = mkOption { default = null; example = "rVXs/Ni9tu3oDBLS4hOyAUAa1qTWVA3loR8eL20os3I="; type = with types; nullOr str; description = '' Base64 preshared key generated by wg genpsk. Optional, and may be omitted. This option adds an additional layer of symmetric-key cryptography to be mixed into the already existing public-key cryptography, for post-quantum resistance. Warning: Consider using presharedKeyFile instead if you do not want to store the key in the world-readable Nix store. ''; }; presharedKeyFile = mkOption { default = null; example = "/private/wireguard_psk"; type = with types; nullOr str; description = '' File pointing to preshared key as generated by wg genpsk. Optional, and may be omitted. This option adds an additional layer of symmetric-key cryptography to be mixed into the already existing public-key cryptography, for post-quantum resistance. ''; }; allowedIPs = mkOption { example = [ "10.192.122.3/32" "10.192.124.1/24" ]; type = with types; listOf str; description = ''List of IP (v4 or v6) addresses with CIDR masks from which this peer is allowed to send incoming traffic and to which outgoing traffic for this peer is directed. The catch-all 0.0.0.0/0 may be specified for matching all IPv4 addresses, and ::/0 may be specified for matching all IPv6 addresses.''; }; endpoint = mkOption { default = null; example = "demo.wireguard.io:12913"; type = with types; nullOr str; description = ''Endpoint IP or hostname of the peer, followed by a colon, and then a port number of the peer.''; }; persistentKeepalive = mkOption { default = null; type = with types; nullOr int; example = 25; description = ''This is optional and is by default off, because most users will not need it. It represents, in seconds, between 1 and 65535 inclusive, how often to send an authenticated empty packet to the peer, for the purpose of keeping a stateful firewall or NAT mapping valid persistently. For example, if the interface very rarely sends traffic, but it might at anytime receive traffic from a peer, and it is behind NAT, the interface might benefit from having a persistent keepalive interval of 25 seconds; however, most users will not need this.''; }; }; }; writeScriptFile = name: text: ((pkgs.writeShellScriptBin name text) + "/bin/${name}"); generateUnit = name: values: assert assertMsg ((values.privateKey != null) != (values.privateKeyFile != null)) "Only one of privateKey or privateKeyFile may be set"; let preUpFile = if values.preUp != "" then writeScriptFile "preUp.sh" values.preUp else null; postUp = optional (values.privateKeyFile != null) "wg set ${name} private-key <(cat ${values.privateKeyFile})" ++ (concatMap (peer: optional (peer.presharedKeyFile != null) "wg set ${name} peer ${peer.publicKey} preshared-key <(cat ${peer.presharedKeyFile})") values.peers) ++ optional (values.postUp != null) values.postUp; postUpFile = if postUp != [] then writeScriptFile "postUp.sh" (concatMapStringsSep "\n" (line: line) postUp) else null; preDownFile = if values.preDown != "" then writeScriptFile "preDown.sh" values.preDown else null; postDownFile = if values.postDown != "" then writeScriptFile "postDown.sh" values.postDown else null; configDir = pkgs.writeTextFile { name = "config-${name}"; executable = false; destination = "/${name}.conf"; text = '' [interface] ${concatMapStringsSep "\n" (address: "Address = ${address}" ) values.address} ${concatMapStringsSep "\n" (dns: "DNS = ${dns}" ) values.dns} '' + optionalString (values.table != null) "Table = ${values.table}\n" + optionalString (values.mtu != null) "MTU = ${toString values.mtu}\n" + optionalString (values.privateKey != null) "PrivateKey = ${values.privateKey}\n" + optionalString (values.listenPort != null) "ListenPort = ${toString values.listenPort}\n" + optionalString (preUpFile != null) "PreUp = ${preUpFile}\n" + optionalString (postUpFile != null) "PostUp = ${postUpFile}\n" + optionalString (preDownFile != null) "PreDown = ${preDownFile}\n" + optionalString (postDownFile != null) "PostDown = ${postDownFile}\n" + concatMapStringsSep "\n" (peer: assert assertMsg (!((peer.presharedKeyFile != null) && (peer.presharedKey != null))) "Only one of presharedKey or presharedKeyFile may be set"; "[Peer]\n" + "PublicKey = ${peer.publicKey}\n" + optionalString (peer.presharedKey != null) "PresharedKey = ${peer.presharedKey}\n" + optionalString (peer.endpoint != null) "Endpoint = ${peer.endpoint}\n" + optionalString (peer.persistentKeepalive != null) "PersistentKeepalive = ${toString peer.persistentKeepalive}\n" + optionalString (peer.allowedIPs != []) "AllowedIPs = ${concatStringsSep "," peer.allowedIPs}\n" ) values.peers; }; configPath = "${configDir}/${name}.conf"; in nameValuePair "wg-quick-${name}" { description = "wg-quick WireGuard Tunnel - ${name}"; requires = [ "network-online.target" ]; after = [ "network.target" "network-online.target" ]; wantedBy = [ "multi-user.target" ]; environment.DEVICE = name; path = [ pkgs.kmod pkgs.wireguard-tools ]; serviceConfig = { Type = "oneshot"; RemainAfterExit = true; }; script = '' ${optionalString (!config.boot.isContainer) "modprobe wireguard"} wg-quick up ${configPath} ''; preStop = '' wg-quick down ${configPath} ''; }; in { ###### interface options = { networking.wg-quick = { interfaces = mkOption { description = "Wireguard interfaces."; default = {}; example = { wg0 = { address = [ "192.168.20.4/24" ]; privateKey = "yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk="; peers = [ { allowedIPs = [ "192.168.20.1/32" ]; publicKey = "xTIBA5rboUvnH4htodjb6e697QjLERt1NAB4mZqp8Dg="; endpoint = "demo.wireguard.io:12913"; } ]; }; }; type = with types; attrsOf (submodule interfaceOpts); }; }; }; ###### implementation config = mkIf (cfg.interfaces != {}) { boot.extraModulePackages = optional (versionOlder kernel.kernel.version "5.6") kernel.wireguard; environment.systemPackages = [ pkgs.wireguard-tools ]; # This is forced to false for now because the default "--validmark" rpfilter we apply on reverse path filtering # breaks the wg-quick routing because wireguard packets leave with a fwmark from wireguard. networking.firewall.checkReversePath = false; systemd.services = mapAttrs' generateUnit cfg.interfaces; }; }