nixos/networkmanager: split modemmanager into a separate module (#316824)

Author: misuzu

nixos/doc/manual/release-notes/rl-2505.section.md

@@ -30,6 +30,8 @@
 
 - [MaryTTS](https://github.com/marytts/marytts), an open-source, multilingual text-to-speech synthesis system written in pure Java. Available as [services.marytts](options.html#opt-services.marytts).
 
+- [networking.modemmanager](options.html#opt-networking.modemmanager) has been split out of [networking.networkmanager](options.html#opt-networking.networkmanager). NetworkManager still enables ModemManager by default, but options exist now to run NetworkManager without ModemManager.
+
 - [Conduwuit](https://conduwuit.puppyirl.gay/), a federated chat server implementing the Matrix protocol, forked from Conduit. Available as [services.conduwuit](#opt-services.conduwuit.enable).
 
 - [Traccar](https://www.traccar.org/), a modern GPS Tracking Platform. Available as [services.traccar](#opt-services.traccar.enable).

nixos/modules/module-list.nix

@@ -1137,6 +1137,7 @@
   ./services/networking/miredo.nix
   ./services/networking/mjpg-streamer.nix
   ./services/networking/mmsd.nix
+  ./services/networking/modemmanager.nix
   ./services/networking/monero.nix
   ./services/networking/morty.nix
   ./services/networking/mosquitto.nix

nixos/modules/services/networking/modemmanager.nix

@@ -0,0 +1,97 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  cfg = config.networking.modemmanager;
+in
+{
+  meta = {
+    maintainers = lib.teams.freedesktop.members;
+  };
+
+  options = with lib; {
+    networking.modemmanager = {
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Whether to use ModemManager to manage modem devices.
+          This is usually used by some higher layer manager such as NetworkManager
+          but can be used standalone especially if using a modem for non-IP
+          connectivity (e.g. GPS).
+        '';
+      };
+
+      package = mkPackageOption pkgs "modemmanager" { };
+
+      fccUnlockScripts = mkOption {
+        type = types.listOf (
+          types.submodule {
+            options = {
+              id = mkOption {
+                type = types.str;
+                description = "vid:pid of either the PCI or USB vendor and product ID";
+              };
+              path = mkOption {
+                type = types.path;
+                description = "Path to the unlock script";
+              };
+            };
+          }
+        );
+        default = [ ];
+        example = literalExpression ''[{ id = "03f0:4e1d"; path = "''${pkgs.modemmanager}/share/ModemManager/fcc-unlock.available.d/03f0:4e1d"; }]'';
+        description = ''
+          List of FCC unlock scripts to enable on the system, behaving as described in
+          https://modemmanager.org/docs/modemmanager/fcc-unlock/#integration-with-third-party-fcc-unlock-tools.
+        '';
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    environment.etc = builtins.listToAttrs (
+      map (
+        e:
+        lib.nameValuePair "ModemManager/fcc-unlock.d/${e.id}" {
+          source = e.path;
+        }
+      ) cfg.fccUnlockScripts
+    );
+
+    systemd.services.ModemManager = {
+      aliases = [ "dbus-org.freedesktop.ModemManager1.service" ];
+      path = lib.optionals (cfg.fccUnlockScripts != [ ]) [
+        pkgs.libqmi
+        pkgs.libmbim
+      ];
+    };
+
+    /*
+      [modem-manager]
+      Identity=unix-group:networkmanager
+      Action=org.freedesktop.ModemManager*
+      ResultAny=yes
+      ResultInactive=no
+      ResultActive=yes
+    */
+    security.polkit.enable = true;
+    security.polkit.extraConfig = ''
+      polkit.addRule(function(action, subject) {
+        if (
+          subject.isInGroup("networkmanager")
+          && action.id.indexOf("org.freedesktop.ModemManager") == 0
+          )
+            { return polkit.Result.YES; }
+      });
+    '';
+
+    environment.systemPackages = [ cfg.package ];
+    systemd.packages = [ cfg.package ];
+    services.dbus.packages = [ cfg.package ];
+    services.udev.packages = [ cfg.package ];
+  };
+}