nixos/bluetooth: add support for disabling plugins

nixos/modules/services/hardware/bluetooth.nix

@@ -1,12 +1,39 @@
 { config, lib, pkgs, ... }:
-
-with lib;
-
 let
   cfg = config.hardware.bluetooth;
-  bluez-bluetooth = cfg.package;
+  package = cfg.package;
 
-in {
+  inherit (lib)
+    mkDefault mkEnableOption mkIf mkOption
+    mkRenamedOptionModule mkRemovedOptionModule
+    concatStringsSep escapeShellArgs
+    optional optionals optionalAttrs recursiveUpdate types;
+
+  cfgFmt = pkgs.formats.ini { };
+
+  # bluez will complain if some of the sections are not found, so just make them
+  # empty (but present in the file) for now
+  defaults = {
+    General.ControllerMode = "dual";
+    Controller = { };
+    GATT = { };
+    Policy.AutoEnable = cfg.powerOnBoot;
+  };
+
+  hasDisabledPlugins = builtins.length cfg.disabledPlugins > 0;
+
+in
+{
+  imports = [
+    (mkRenamedOptionModule [ "hardware" "bluetooth" "config" ] [ "hardware" "bluetooth" "settings" ])
+    (mkRemovedOptionModule [ "hardware" "bluetooth" "extraConfig" ] ''
+      Use hardware.bluetooth.settings instead.
+
+      This is part of the general move to use structured settings instead of raw
+      text for config as introduced by RFC0042:
+      https://github.com/NixOS/rfcs/blob/master/rfcs/0042-config-option.md
+    '')
+  ];
 
   ###### interface
 
@@ -38,8 +65,15 @@ in {
         '';
       };
 
-      config = mkOption {
+      disabledPlugins = mkOption {
-        type = with types; attrsOf (attrsOf (oneOf [ bool int str ]));
+        type = types.listOf types.str;
+        default = [ ];
+        description = "Built-in plugins to disable";
+      };
+
+      settings = mkOption {
+        type = cfgFmt.type;
+        default = { };
         example = {
           General = {
             ControllerMode = "bredr";
@@ -47,50 +81,40 @@ in {
         };
         description = "Set configuration for system-wide bluetooth (/etc/bluetooth/main.conf).";
       };
-
-      extraConfig = mkOption {
-        type = with types; nullOr lines;
-        default = null;
-        example = ''
-          [General]
-          ControllerMode = bredr
-        '';
-        description = ''
-          Set additional configuration for system-wide bluetooth (/etc/bluetooth/main.conf).
-        '';
     };
   };
 
-  };
-
   ###### implementation
 
   config = mkIf cfg.enable {
-    warnings = optional (cfg.extraConfig != null) "hardware.bluetooth.`extraConfig` is deprecated, please use hardware.bluetooth.`config`.";
+    environment.systemPackages = [ package ]
+      ++ optional cfg.hsphfpd.enable pkgs.hsphfpd;
 
-    hardware.bluetooth.config = {
+    environment.etc."bluetooth/main.conf".source =
-      Policy = {
+      cfgFmt.generate "main.conf" (recursiveUpdate defaults cfg.settings);
-        AutoEnable = mkDefault cfg.powerOnBoot;
+    services.udev.packages = [ package ];
-      };
+    services.dbus.packages = [ package ]
-    };
+      ++ optional cfg.hsphfpd.enable pkgs.hsphfpd;
-
+    systemd.packages = [ package ];
-    environment.systemPackages = [ bluez-bluetooth ]
-      ++ optionals cfg.hsphfpd.enable [ pkgs.hsphfpd ];
-
-    environment.etc."bluetooth/main.conf"= {
-      source = pkgs.writeText "main.conf"
-        (generators.toINI { } cfg.config + optionalString (cfg.extraConfig != null) cfg.extraConfig);
-    };
-
-    services.udev.packages = [ bluez-bluetooth ];
-    services.dbus.packages = [ bluez-bluetooth ]
-      ++ optionals cfg.hsphfpd.enable [ pkgs.hsphfpd ];
-    systemd.packages       = [ bluez-bluetooth ];
 
     systemd.services = {
-      bluetooth = {
+      bluetooth =
+        let
+          # `man bluetoothd` will refer to main.conf in the nix store but bluez
+          # will in fact load the configuration file at /etc/bluetooth/main.conf
+          # so force it here to avoid any ambiguity and things suddenly breaking
+          # if/when the bluez derivation is changed.
+          args = [ "-f /etc/bluetooth/main.conf" ]
+            ++ optional hasDisabledPlugins
+            "--noplugin=${concatStringsSep "," cfg.disabledPlugins}";
+        in
+        {
           wantedBy = [ "bluetooth.target" ];
           aliases = [ "dbus-org.bluez.service" ];
+          serviceConfig.ExecStart = [
+            ""
+            "${package}/libexec/bluetooth/bluetoothd ${escapeShellArgs " " args}"
+          ];
           # restarting can leave people without a mouse/keyboard
           unitConfig.X-RestartIfChanged = false;
         };
@@ -99,27 +123,23 @@ in {
       hsphfpd = {
         after = [ "bluetooth.service" ];
         requires = [ "bluetooth.service" ];
-          wantedBy = [ "multi-user.target" ];
+        wantedBy = [ "bluetooth.target" ];
 
         description = "A prototype implementation used for connecting HSP/HFP Bluetooth devices";
         serviceConfig.ExecStart = "${pkgs.hsphfpd}/bin/hsphfpd.pl";
       };
-      })
+    });
-      ;
 
     systemd.user.services = {
       obex.aliases = [ "dbus-org.bluez.obex.service" ];
     }
-      // (optionalAttrs cfg.hsphfpd.enable {
+    // optionalAttrs cfg.hsphfpd.enable {
       telephony_client = {
         wantedBy = [ "default.target" ];
 
         description = "telephony_client for hsphfpd";
         serviceConfig.ExecStart = "${pkgs.hsphfpd}/bin/telephony_client.pl";
       };
-      })
-      ;
-
     };
-
+  };
 }