nixos/create_ap: init

Co-authored-by: Silvan Mosberger <contact@infinisil.com>

nixos/modules/module-list.nix

@@ -613,6 +613,7 @@
   ./services/networking/hylafax/default.nix
   ./services/networking/i2pd.nix
   ./services/networking/i2p.nix
+  ./services/networking/create_ap.nix
   ./services/networking/iodine.nix
   ./services/networking/iperf3.nix
   ./services/networking/ircd-hybrid/default.nix

nixos/modules/services/networking/create_ap.nix

@@ -0,0 +1,134 @@
+{ config, lib, pkgs, ... }:
+with lib;
+
+let
+  cfg = config.services.create_ap;
+
+  valueToText =
+    let
+      conversions = {
+        string = id;
+        int = toString;
+        bool = value: if value then "1" else "0";
+      };
+    in value: conversions.${builtins.typeOf value} value;
+
+  configFile = pkgs.writeText "create_ap.conf"
+    (concatStrings (mapAttrsToList (name: value:
+      "${name}=${valueToText value}\n"
+    ) (filterAttrs (_: value: value != null) cfg.settings)));
+
+  wifiIface = cfg.settings.WIFI_IFACE;
+  inetIface = cfg.settings.INTERNET_IFACE;
+
+in {
+
+  options.services.create_ap = with types; {
+    enable = mkEnableOption "Enable Create Access Point Service";
+
+    settings = mkOption {
+      type = attrsOf (nullOr (oneOf [ str int bool ]));
+      description = ''
+        create_ap configuration, see <link xlink:href="https://github.com/oblique/create_ap/blob/master/create_ap.conf"/>
+        for information on supported values.
+      '';
+      example = literalExample ''
+        {
+          HIDDEN = true;
+          FREQ_BAND = 5;
+          DHCP_DNS = "1.1.1.1";
+          COUNTRY = "US";
+        }
+      '';
+    };
+
+    wifiInterface = mkOption {
+      description = ''
+        Wi-Fi interface to use (Use <command>ip link show</command> to list available).
+      '';
+      type = str;
+      example = "wlan0";
+    };
+
+    internetInterface = mkOption {
+      description = ''
+        Interface to use for internet connection (Use <command>ip link show</command> to list available).
+      '';
+      type = str;
+      example = "enp0";
+    };
+
+    ssid = mkOption {
+      description = "SSID of the access point.";
+      type = str;
+      example = "MyAccessPoint";
+    };
+
+    passphrase = mkOption {
+      description = "Passphrase to use for access point.";
+      type = str;
+      example = "12345678";
+    };
+
+    gateway = mkOption {
+      description = "IPv4 Gateway for the Access Point.";
+      type = str;
+      default = "192.168.12.1";
+      example = "10.0.0.1";
+    };
+
+    channel = mkOption {
+      type = either str int;
+      example = 1;
+      default = "default";
+      description = "WLAN Channel number.";
+    };
+  };
+
+  config = mkIf cfg.enable {
+
+    services.create_ap.settings = {
+      DAEMONIZE = false;
+      CHANNEL = mkDefault cfg.channel;
+      GATEWAY = mkDefault cfg.gateway;
+      WIFI_IFACE = mkDefault cfg.wifiInterface;
+      INTERNET_IFACE = mkDefault cfg.internetInterface;
+      SSID = mkDefault cfg.ssid;
+      PASSPHRASE = mkDefault cfg.passphrase;
+    };
+
+    environment.systemPackages =  [ pkgs.create_ap ];
+
+    systemd.services.create_ap = {
+      description = "Create AP Service";
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target"
+                "sys-subsystem-net-devices-${wifiIface}.device"
+                "sys-subsystem-net-devices-${inetIface}.device" ];
+      bindsTo = [ "sys-subsystem-net-devices-${wifiIface}.device"
+                  "sys-subsystem-net-devices-${inetIface}.device" ];
+      serviceConfig =
+        let capabilities = [
+          "CAP_CHOWN"
+          "CAP_DAC_OVERRIDE"
+          "CAP_DAC_READ_SEARCH"
+          "CAP_KILL"
+          "CAP_NET_ADMIN"
+          "CAP_NET_RAW"
+          "CAP_NET_BIND_SERVICE"
+        ]; in {
+          KillSignal = "SIGINT";
+          Restart = "on-failure";
+          RestartSec = 5;
+          DynamicUser = true;
+          ProtectSystem = "strict";
+          ProtectHome = true;
+          # create_ap parses and updates NetworkManager.conf
+          ReadWritePaths = "-/etc/NetworkManager/";
+          AmbientCapabilities = capabilities;
+          CapabilityBoundingSet = capabilities;
+          ExecStart = "${pkgs.create_ap}/bin/create_ap --config ${configFile}";
+        };
+    };
+  };
+}