feat(dbus): Add InterfaceWlan for WLAN configuration management

Introduced `InterfaceWlan` to enable/disable WLAN hardware, check
availability, and track status via D-Bus. Integrated the new interface
with the bus provider initialization to ensure proper registration.

Signed-off-by: Sven Sager <s.sager@kunbus.com>

.gitignore

@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH <support@kunbus.com>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]

.gitlab-ci.yml

@@ -0,0 +1,40 @@
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH <support@kunbus.com>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+default:
+  tags:
+    - self-hosted
+    - host-arm64
+    - high-perf
+
+include:
+  - project: "revolutionpi/infrastructure/ci-templates"
+    file: "base.yml"
+  - project: "revolutionpi/infrastructure/ci-templates"
+    file: "check-commit/lint-commit.yml"
+  - project: "revolutionpi/infrastructure/ci-templates"
+    file: "reuse-lint.yml"
+  - project: "revolutionpi/infrastructure/ci-templates"
+    file: "package-devel.yml"
+  - local: debian/gitlab-ci.yml
+    rules:
+      - exists:
+          - debian/gitlab-ci.yml
+
+run_tests:
+  stage: test
+  image: python:3.11-bookworm
+  script:
+    - apt-get update
+    - apt-get -y install dbus libgirepository1.0-dev
+    - dbus-uuidgen --ensure=/etc/machine-id
+    - pip install -r requirements.txt
+    - PYTHONPATH=src dbus-run-session -- pytest -v --junitxml=report.xml --cov=src --cov-report term --cov-report xml:coverage.xml
+  coverage: '/(?i)total.*? (100(?:\.0+)?\%|[1-9]?\d(?:\.\d+)?\%)$/'
+  artifacts:
+    reports:
+      junit: ${CI_PROJECT_DIR}/report.xml
+      coverage_report:
+        coverage_format: cobertura
+        path: coverage.xml

MANIFEST.in

@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH <support@kunbus.com>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 recursive-include .reuse *
 recursive-include data *
 recursive-include LICENSES *

Makefile

@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH <support@kunbus.com>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 SHELL        := bash
 MAKEFLAGS     = --no-print-directory --no-builtin-rules
 .DEFAULT_GOAL = all

README.md

@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2025 KUNBUS GmbH <support@kunbus.com>
+
+SPDX-License-Identifier: GPL-2.0-or-later
+-->
+
 # Middleware for Revolution Pi
 
 This middleware will support D-Bus as IPC interface.

examples/revpi-config

@@ -0,0 +1,100 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH
+# SPDX-License-Identifier: GPL-2.0-or-later
+from argparse import ArgumentParser, SUPPRESS
+from typing import NamedTuple
+
+from pydbus import SessionBus, SystemBus
+
+FeatureMapping = NamedTuple("FeatureMapping", [("dbus_interface", str), ("name", str)])
+
+REVPI_DBUS_NAME = "com.revolutionpi.middleware1"
+REVPI_DBUS_BASE_PATH = "/com/revolutionpi/middleware1"
+IFACE_SOFTWARE_SERVICES = "com.revolutionpi.middleware1.SoftwareServices"
+IFACE_REVPI_CONFIG = "com.revolutionpi.middleware1.RevpiConfig"
+
+REVPI_FEATURE_MAPPINGS = {
+    "gui": FeatureMapping(IFACE_REVPI_CONFIG, "gui"),
+    "revpi-con-can": FeatureMapping(IFACE_REVPI_CONFIG, "revpi-con-can"),
+    "dphys-swapfile": FeatureMapping(IFACE_REVPI_CONFIG, "swapfile"),
+    "pimodbus-master": FeatureMapping(IFACE_SOFTWARE_SERVICES, "pimodbus-master"),
+    "pimodbus-slave": FeatureMapping(IFACE_SOFTWARE_SERVICES, "pimodbus-slave"),
+    "systemd-timesyncd": FeatureMapping(IFACE_SOFTWARE_SERVICES, "ntp"),
+    "ssh": FeatureMapping(IFACE_SOFTWARE_SERVICES, "ssh"),
+    "nodered": FeatureMapping(IFACE_SOFTWARE_SERVICES, "nodered"),
+    "noderedrevpinodes-server": FeatureMapping(IFACE_SOFTWARE_SERVICES, "noderedrevpinodes-server"),
+    "revpipyload": FeatureMapping(IFACE_SOFTWARE_SERVICES, "revpipyload"),
+    "bluetooth": FeatureMapping(IFACE_REVPI_CONFIG, "bluetooth"),
+    "ieee80211": FeatureMapping(IFACE_REVPI_CONFIG, "wlan"),
+    "avahi": FeatureMapping(IFACE_SOFTWARE_SERVICES, "avahi"),
+    "external-antenna": FeatureMapping(IFACE_REVPI_CONFIG, "external-antenna"),
+}
+
+# Generate command arguments
+parser = ArgumentParser(
+    prog="revpi-config",
+    description="Configuration tool for Revolution Pi.",
+)
+parser.add_argument(
+    "--use-session-bus",
+    dest="use_session_bus",
+    action="store_true",
+    default=False,
+    help=SUPPRESS,
+)
+parser.add_argument(
+    "action",
+    choices=["enable", "disable", "status", "available", "availstat"],
+    help="Action to be executed: enable, disable, status or available.",
+)
+parser.add_argument(
+    "feature",
+    nargs="*",
+    help="Name of the feature to configure.",
+)
+args = parser.parse_args()
+
+# Init dbus
+bus = SessionBus() if args.use_session_bus else SystemBus()
+revpi_middleware = bus.get(REVPI_DBUS_NAME, REVPI_DBUS_BASE_PATH)
+
+lst_results = []
+for feature in args.feature:
+
+    # Get the mappings
+    feature_mapping = REVPI_FEATURE_MAPPINGS.get(feature, None)
+
+    if feature_mapping is None:
+        if args.action in ("enable", "disable"):
+            # Missing feature with action enable/disable will return 5
+            lst_results.append(5)
+        elif args.action == "availstat":
+            # Missing feature with action availstat will return 2
+            lst_results.append(2)
+        else:
+            # Missing feature with action status/available will return 0
+            lst_results.append(0)
+
+        continue
+
+    dbus_interface = revpi_middleware[feature_mapping.dbus_interface]
+
+    if args.action == "enable":
+        dbus_interface.Enable(feature_mapping.name)
+        lst_results.append(0)
+
+    elif args.action == "disable":
+        dbus_interface.Disable(feature_mapping.name)
+        lst_results.append(0)
+
+    elif args.action in ("status", "availstat"):
+        status = dbus_interface.GetStatus(feature_mapping.name)
+        lst_results.append(int(status))
+
+    elif args.action == "available":
+        availability = dbus_interface.GetAvailability(feature_mapping.name)
+        lst_results.append(int(availability))
+
+if lst_results:
+    print(" ".join(map(str, lst_results)))

pyproject.toml

@@ -1,2 +1,6 @@
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH <support@kunbus.com>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 [tool.black]
 line-length = 100

requirements.txt

@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH <support@kunbus.com>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 # Build dependencies
 pip-licenses
 Pyinstaller

src/revpi_middleware/dbus_middleware1/bus_provider.py

@@ -10,7 +10,7 @@ from pydbus import SessionBus, SystemBus
 
 from . import REVPI_DBUS_NAME
 from .process_image import InterfacePiControl
-from .system_config import InterfaceRevpiConfig
+from .system_config import InterfaceRevpiConfig, InterfaceSoftwareServices, InterfaceWlan
 
 log = getLogger(__name__)
 
@@ -41,8 +41,10 @@ class BusProvider(Thread):
         #   ("Subdir2", Example()),
         #   ("Subdir2/Whatever", Example())
         lst_interfaces = [
-            InterfacePiControl(self.picontrol_device, self.config_rsc),
+            InterfacePiControl(self._bus, self.picontrol_device, self.config_rsc),
-            InterfaceRevpiConfig(),
+            InterfaceRevpiConfig(self._bus),
+            InterfaceSoftwareServices(self._bus),
+            InterfaceWlan(self._bus),
         ]
 
         try:

src/revpi_middleware/dbus_middleware1/dbus_helper.py

@@ -2,8 +2,10 @@
 # SPDX-FileCopyrightText: 2025 KUNBUS GmbH
 # SPDX-License-Identifier: GPL-2.0-or-later
 """Helper for dbus."""
-
 from logging import getLogger
+from typing import Union
+
+from pydbus import SessionBus, SystemBus
 
 log = getLogger(__name__)
 
@@ -13,6 +15,9 @@ REVPI_DBUS_BASE_PATH = "/com/revolutionpi/middleware1"
 
 class DbusInterface:
 
+    def __init__(self, bus: Union[SessionBus, SystemBus]):
+        self.bus = bus
+
     def cleanup(self):
         """
         Represents a method responsible for performing cleanup operations. This method is executed to properly

src/revpi_middleware/dbus_middleware1/process_image/interface_picontrol.py

@@ -26,7 +26,9 @@ class InterfacePiControl(DbusInterface):
 
     NotifyDriverReset = signal()
 
-    def __init__(self, picontrol_device: str, config_rsc: str):
+    def __init__(self, bus, picontrol_device: str, config_rsc: str):
+        super().__init__(bus)
+
         self.picontrol_device = picontrol_device
         self.config_rsc = config_rsc
 

src/revpi_middleware/dbus_middleware1/system_config/__init__.py

@@ -3,3 +3,5 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 """D-Bus interfaces for system configuration."""
 from .interface_config import InterfaceRevpiConfig
+from .interface_services import InterfaceSoftwareServices
+from .interface_wlan import InterfaceWlan

src/revpi_middleware/dbus_middleware1/system_config/interface_config.py

@@ -5,16 +5,15 @@
 from collections import namedtuple
 from logging import getLogger
 
+from pydbus.generic import signal
+
 from .revpi_config import (
     ConfigActions,
-    configure_avahi_daemon,
     configure_bluetooth,
     configure_con_can,
     configure_dphys_swapfile,
     configure_external_antenna,
     configure_gui,
-    configure_wlan,
-    simple_systemd,
 )
 from ..dbus_helper import DbusInterface
 
@@ -42,19 +41,32 @@ class InterfaceRevpiConfig(DbusInterface):
                 <arg name="available" type="b" direction="out"/>
             </method>
             <property name="available_features" type="as" access="read"/>
+            <signal name="StatusChanged">
+                <arg name="feature" type="s"/>
+                <arg name="status" type="b"/>
+            </signal>
+            <signal name="AvailabilityChanged">
+                <arg name="feature" type="s"/>
+                <arg name="available" type="b"/>
+            </signal>
         </interface>
     </node>
     """
 
+    AvailabilityChanged = signal()
+    StatusChanged = signal()
+
     def Disable(self, feature: str) -> None:
         """Disable the feature."""
         feature_function = get_feature(feature)
         feature_function.function(ConfigActions.DISABLE, *feature_function.args)
+        self.StatusChanged(feature, False)
 
     def Enable(self, feature: str) -> None:
         """Enable the feature."""
         feature_function = get_feature(feature)
         feature_function.function(ConfigActions.ENABLE, *feature_function.args)
+        self.StatusChanged(feature, True)
 
     def GetStatus(self, feature: str) -> bool:
         """Get feature status."""
@@ -83,18 +95,7 @@ def get_feature(feature: str) -> FeatureFunction:
 AVAILABLE_FEATURES = {
     "gui": FeatureFunction(configure_gui, []),
     "revpi-con-can": FeatureFunction(configure_con_can, []),
-    "dphys-swapfile": FeatureFunction(configure_dphys_swapfile, []),
+    "swapfile": FeatureFunction(configure_dphys_swapfile, []),
-    "pimodbus-master": FeatureFunction(simple_systemd, ["pimodbus-master.service"]),
-    "pimodbus-slave": FeatureFunction(simple_systemd, ["pimodbus-slave.service"]),
-    "systemd-timesyncd": FeatureFunction(simple_systemd, ["systemd-timesyncd.service"]),
-    "ssh": FeatureFunction(simple_systemd, ["ssh.service"]),
-    "nodered": FeatureFunction(simple_systemd, ["nodered.service"]),
-    "noderedrevpinodes-server": FeatureFunction(
-        simple_systemd, ["noderedrevpinodes-server.service"]
-    ),
-    "revpipyload": FeatureFunction(simple_systemd, ["revpipyload.service"]),
     "bluetooth": FeatureFunction(configure_bluetooth, []),
-    "wlan": FeatureFunction(configure_wlan, []),
-    "avahi": FeatureFunction(configure_avahi_daemon, []),
     "external-antenna": FeatureFunction(configure_external_antenna, []),
 }

src/revpi_middleware/dbus_middleware1/system_config/interface_services.py

@@ -0,0 +1,205 @@
+# -*- coding: utf-8 -*-
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH
+# SPDX-License-Identifier: GPL-2.0-or-later
+"""D-Bus interfaces for software services."""
+from logging import getLogger
+from typing import List
+
+from pydbus.generic import signal
+
+from ..dbus_helper import DbusInterface
+from ..systemd_helper import simple_systemd, ServiceActions
+
+log = getLogger(__name__)
+
+
+class InterfaceSoftwareServices(DbusInterface):
+    """
+    <node>
+        <interface name="com.revolutionpi.middleware1.SoftwareServices">
+            <method name="Disable">
+                <arg name="feature" type="s" direction="in"/>
+            </method>
+            <method name="Enable">
+                <arg name="feature" type="s" direction="in"/>
+            </method>
+            <method name="GetStatus">
+                <arg name="feature" type="s" direction="in"/>
+                <arg name="status" type="b" direction="out"/>
+            </method>
+            <method name="GetAvailability">
+                <arg name="feature" type="s" direction="in"/>
+                <arg name="available" type="b" direction="out"/>
+            </method>
+            <property name="available_features" type="as" access="read"/>
+            <signal name="StatusChanged">
+                <arg name="feature" type="s"/>
+                <arg name="status" type="b"/>
+            </signal>
+            <signal name="AvailabilityChanged">
+                <arg name="feature" type="s"/>
+                <arg name="available" type="b"/>
+            </signal>
+        </interface>
+    </node>
+    """
+
+    AvailabilityChanged = signal()
+    StatusChanged = signal()
+
+    def __init__(self, bus):
+        super().__init__(bus)
+
+        self.mrk_available = {}
+        self.mrk_status = {}
+
+        self.services = {
+            "pimodbus-master": ["pimodbus-master.service"],
+            "pimodbus-slave": ["pimodbus-slave.service"],
+            "ntp": ["systemd-timesyncd.service"],
+            "ssh": ["ssh.service"],
+            "nodered": ["nodered.service"],
+            "noderedrevpinodes-server": ["noderedrevpinodes-server.service"],
+            "revpipyload": ["revpipyload.service"],
+            "avahi": ["avahi-daemon.service", "avahi-daemon.socket"],
+        }
+
+        # Create a systemd manager interface object
+        systemd = self.bus.get(
+            "org.freedesktop.systemd1",
+            "/org/freedesktop/systemd1",
+        )
+        systemd_manager = systemd["org.freedesktop.systemd1.Manager"]
+
+        # Load all unit paths and subscribe to properties changed signal
+        self.object_paths = {}
+        for feature in self.services:
+
+            # Get the status and availability of the feature
+            self.mrk_available[feature] = self.GetAvailability(feature)
+            self.mrk_status[feature] = self.GetStatus(feature)
+
+            # Subscribe to properties changed signal for each unit
+            for unit_name in self.services[feature]:
+                unit_path = systemd_manager.LoadUnit(unit_name)
+                self.object_paths[unit_path] = feature
+
+                self.bus.subscribe(
+                    iface="org.freedesktop.DBus.Properties",
+                    signal="PropertiesChanged",
+                    object=unit_path,
+                    signal_fired=self._callback_properties_changed,
+                )
+
+        # Subscribe to the reloading signal to update the availability of the feature
+        self.bus.subscribe(
+            iface="org.freedesktop.systemd1.Manager",
+            signal="Reloading",
+            object="/org/freedesktop/systemd1",
+            signal_fired=self._callback_reloading_signal,
+        )
+
+    def _callback_reloading_signal(self, sender, object_path, interface, signal, parameters):
+        """
+        Handles the signal emitted for reloading and checks for changes in availability
+        and status for a set of services. If changes are identified, corresponding
+        update methods are triggered to reflect the new states.
+
+        Args:
+            sender: The entity sending the signal.
+            object_path: Path to the object emitting the signal.
+            interface: Interface through which the signal is sent.
+            signal: The signal being received.
+            parameters: A list of parameters associated with the signal.
+
+        Raises:
+            None
+        """
+        if parameters[0]:
+            return
+
+        for feature in self.services:
+            availability = self.GetAvailability(feature)
+            if self.mrk_available[feature] != availability:
+                self.mrk_available[feature] = availability
+                self.AvailabilityChanged(feature, availability)
+
+            status = self.GetStatus(feature)
+            if self.mrk_status[feature] != status:
+                self.mrk_status[feature] = status
+                self.StatusChanged(feature, status)
+
+    def _callback_properties_changed(self, sender, object_path, interface, signal, parameters):
+        """
+        Handles the 'PropertiesChanged' signal callback by updating internal status tracking for given
+        features and invoking status change notifications if necessary.
+
+        Args:
+            sender (Any): Information about the signal sender.
+            object_path (str): The path of the object emitting the signal.
+            interface (str): The interface where the signal was emitted.
+            signal (str): The name of the emitted signal.
+            parameters (tuple): Signal parameters containing interface name, changed properties, and
+                invalidated properties.
+
+        Raises:
+            TypeError: If the 'parameters' argument does not unpack to three expected values.
+        """
+        interface, changed_properties, invalidated_properties = parameters
+        if "ActiveState" not in changed_properties:
+            return
+
+        feature = self.object_paths[object_path]
+        status = self.GetStatus(feature)
+        if self.mrk_status[feature] != status:
+            self.mrk_status[feature] = status
+            self.StatusChanged(feature, status)
+
+    def _get_unit_names(self, feature: str) -> List[str]:
+        if feature not in self.services:
+            raise ValueError(f"feature {feature} does not exist")
+        return self.services[feature]
+
+    def Disable(self, feature: str) -> None:
+        """Disable the feature."""
+        action = ServiceActions.DISABLE
+        unit_names = self._get_unit_names(feature)
+
+        for unit_name in unit_names:
+            simple_systemd(action, unit_name)
+
+    def Enable(self, feature: str) -> None:
+        """Enable the feature."""
+        action = ServiceActions.ENABLE
+        unit_names = self._get_unit_names(feature)
+
+        for unit_name in unit_names:
+            simple_systemd(action, unit_name)
+
+    def GetStatus(self, feature: str) -> bool:
+        """Get feature status."""
+        unit_names = self._get_unit_names(feature)
+        rc_status = True
+
+        for unit_name in unit_names:
+            if not simple_systemd(ServiceActions.STATUS, unit_name):
+                rc_status = False
+                break
+
+        return rc_status
+
+    def GetAvailability(self, feature: str) -> bool:
+        """Get feature availability on the RevPi."""
+        unit_names = self._get_unit_names(feature)
+        rc_available = True
+
+        for unit_name in unit_names:
+            if not simple_systemd(ServiceActions.AVAILABLE, unit_name):
+                rc_available = False
+                break
+
+        return rc_available
+
+    @property
+    def available_features(self) -> list[str]:
+        return list(self.services.keys())

src/revpi_middleware/dbus_middleware1/system_config/interface_wlan.py

@@ -0,0 +1,90 @@
+# -*- coding: utf-8 -*-
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH
+# SPDX-License-Identifier: GPL-2.0-or-later
+"""D-Bus interfaces for wlan configuration."""
+from logging import getLogger
+from threading import Event, Thread
+
+from pydbus.generic import signal
+
+from .revpi_config import configure_wlan, ConfigActions
+from ..dbus_helper import DbusInterface
+
+log = getLogger(__name__)
+
+
+class InterfaceWlan(DbusInterface):
+    """
+    <node>
+        <interface name="com.revolutionpi.middleware1.WlanConfiguration">
+            <method name="Enable">
+                <annotation name="org.freedesktop.DBus.Method.NoReply" value="true"/>
+            </method>
+            <method name="Disable">
+                <annotation name="org.freedesktop.DBus.Method.NoReply" value="true"/>
+            </method>
+            <property name="available" type="b" access="read">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
+            </property>
+            <property name="status" type="s" access="read">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="true"/>
+            </property>
+        </interface>
+    </node>
+    """
+
+    PropertiesChanged = signal()
+
+    def __init__(self, bus):
+        super().__init__(bus)
+        self._status = ""
+
+        # NetworkManager-Objekt abrufen
+        self.bus_nm = self.bus.get(
+            "org.freedesktop.NetworkManager",
+            "/org/freedesktop/NetworkManager",
+        )
+
+        # Prepare status value and thread
+        self.evt_stop_threading = Event()
+        self._update_status(suppress_signal=True)
+        self.th_run_status_update = Thread(
+            target=self._run_status_update,
+            daemon=True,
+        ).start()
+
+    def _run_status_update(self, *args, **kwargs):
+        while not self.evt_stop_threading.wait(1.0):
+            self._update_status()
+
+    def _update_status(self, suppress_signal=False) -> None:
+        str_status = "enabled" if configure_wlan(ConfigActions.STATUS) else "disabled"
+        if self._status != str_status:
+            self._status = str_status
+
+            if not suppress_signal:
+                self.PropertiesChanged(
+                    "com.revolutionpi.middleware1.WlanConfiguration",
+                    {"status": str_status},
+                    [],
+                )
+
+    def cleanup(self):
+        self.evt_stop_threading.set()
+
+    def Disable(self) -> None:
+        """Disable integrated WLAN hardware."""
+        configure_wlan(ConfigActions.DISABLE)
+
+    def Enable(self) -> None:
+        """Enable integrated WLAN hardware."""
+        configure_wlan(ConfigActions.ENABLE)
+
+    @property
+    def available(self) -> bool:
+        """Check if WLAN hardware is available."""
+        return configure_wlan(ConfigActions.AVAILABLE)
+
+    @property
+    def status(self) -> str:
+        return self._status

src/revpi_middleware/dbus_middleware1/system_config/revpi_config.py

@@ -10,12 +10,13 @@ from glob import glob
 from logging import getLogger
 from os import X_OK, access
 from os.path import exists, join
-from threading import Thread
+from threading import Lock
 from typing import List, Optional
 
 from pydbus import SystemBus
 
 from ..dbus_helper import grep
+from ..systemd_helper import simple_systemd, ServiceActions
 
 log = getLogger(__name__)
 
@@ -24,6 +25,8 @@ ConfigVariable = namedtuple("ConfigVariable", ["name", "value", "line_index"])
 LINUX_BT_CLASS_PATH = "/sys/class/bluetooth"
 LINUX_WLAN_CLASS_PATH = "/sys/class/ieee80211"
 CONFIG_TXT_LOCATIONS = ("/boot/firmware/config.txt", "/boot/config.txt")
+CMDLINE_TXT_LOCK = Lock()
+CONFIG_TXT_LOCK = Lock()
 
 
 class ComputeModuleTypes(IntEnum):
@@ -42,6 +45,7 @@ class ComputeModuleTypes(IntEnum):
         CM4S (int): Represents a Compute Module 4S.
         CM5 (int): Represents a Compute Module 5.
     """
+
     UNKNOWN = 0
     CM1 = 6
     CM3 = 10
@@ -58,6 +62,7 @@ class ConfigActions(Enum):
     actions. It can be used to ensure consistency when working with or defining
     such actions in a system.
     """
+
     ENABLE = "enable"
     DISABLE = "disable"
     STATUS = "status"
@@ -217,6 +222,87 @@ class RevPiConfig:
         return bool(self._wlan_class_path)
 
 
+class CmdLineTxt:
+    """
+    Represents operations on a `cmdline.txt` configuration file.
+
+    This class provides functionality to read, modify, and save the
+    `cmdline.txt` file commonly used for system configurations. It allows
+    setting key-value pairs, removing keys, and manages file locking to ensure
+    thread-safe modifications.
+    """
+
+    # Value is optional, "?:=" non-capturing the "="
+    re_name_value = re.compile(r"(?P<key>[^\s=]+)(?:=(?P<value>\S+))?")
+
+    def __init__(self):
+        self._cmdline_txt_path = ""
+        for path in CONFIG_TXT_LOCATIONS:
+            if exists(path):
+                self._cmdline_txt_path = path
+                break
+
+        if not self._cmdline_txt_path:
+            raise FileNotFoundError("no config.txt found")
+
+    def _get_cmdline_dict(self) -> dict:
+        with CMDLINE_TXT_LOCK:
+            with open(self._cmdline_txt_path, "r") as file:
+                cmdline = file.read()
+
+        return {
+            match.group("key"): match.group("value")
+            for match in self.re_name_value.finditer(cmdline)
+        }
+
+    def _write_cmdline_dict(self, cmdline_dict: dict) -> None:
+        with CMDLINE_TXT_LOCK:
+
+            tmp_path = f"{self._cmdline_txt_path}.tmp"
+            with open(tmp_path, "w") as file:
+                str_cmdline = ""
+                for key, value in cmdline_dict.items():
+                    if value is None:
+                        str_cmdline += f"{key} "
+                    else:
+                        str_cmdline += f"{key}={value} "
+
+                str_cmdline = str_cmdline.strip()
+                file.write(str_cmdline + "\n")
+
+            shutil.move(tmp_path, self._cmdline_txt_path)
+
+    def remove_key(self, key: str) -> None:
+        """
+        Removes a specified key from the config.txt file.
+
+        Parameters:
+        key: str
+            The key to be removed from the config.txt file.
+        """
+        dc_cmdline = self._get_cmdline_dict()
+        if key in dc_cmdline:
+            del dc_cmdline[key]
+            self._write_cmdline_dict(dc_cmdline)
+
+    def set_key_value(self, key: str, value: Optional[str] = None) -> None:
+        """
+        Sets a given key-value pair in the config.txt file. If the key does not
+        exist or the value differs from the current one, the pair is updated.
+        If the value is None, just the key is set without a value.
+
+        Parameters:
+        key: str
+            The key to set in the config.txt file.
+        value: Optional[str], default = None
+            The value to associate with the key, defaulting to None.
+        """
+        dc_cmdline = self._get_cmdline_dict()
+        if key not in dc_cmdline or dc_cmdline.get(key, value) != value:
+            dc_cmdline[key] = value
+            self._write_cmdline_dict(dc_cmdline)
+
+
 class ConfigTxt:
     """
     Configuration file handler for managing 'config.txt'.
@@ -226,12 +312,8 @@ class ConfigTxt:
     to manipulate specific parameters within the configuration and supports
     managing dtoverlay and dtparam entries. The primary aim of this class
     is to abstract file operations and make modifications user-friendly.
-
-    Attributes:
-        _config_txt_path (str): The path to the configuration file `config.txt`.
-        _config_txt_lines (list[str]): Contains all lines of the configuration
-            file as a list of strings, where each string represents a line.
     """
+
     re_name_value = re.compile(r"^\s*(?!#)(?P<name>[^=\s].+?)\s*=\s*(?P<value>\S+)\s*$")
 
     def __init__(self):
@@ -315,8 +397,9 @@ class ConfigTxt:
         Returns:
             None
         """
-        with open(self._config_txt_path, "r") as f:
+        with CONFIG_TXT_LOCK:
-            self._config_txt_lines = f.readlines()
+            with open(self._config_txt_path, "r") as f:
+                self._config_txt_lines = f.readlines()
 
     def save_config(self):
         """
@@ -330,10 +413,11 @@ class ConfigTxt:
         if not self._config_txt_lines:
             return
 
-        tmp_path = f"{self._config_txt_path}.tmp"
+        with CONFIG_TXT_LOCK:
-        with open(tmp_path, "w") as f:
+            tmp_path = f"{self._config_txt_path}.tmp"
-            f.writelines(self._config_txt_lines)
+            with open(tmp_path, "w") as f:
-        shutil.move(tmp_path, self._config_txt_path)
+                f.writelines(self._config_txt_lines)
+            shutil.move(tmp_path, self._config_txt_path)
 
         self._config_txt_lines.clear()
 
@@ -432,18 +516,6 @@ class ConfigTxt:
         return self._config_txt_path
 
 
-def configure_avahi_daemon(action: ConfigActions):
-    return_value = simple_systemd(action, "avahi-daemon.service")
-
-    # Post actions for avahi-daemon
-    if action in (ConfigActions.ENABLE, ConfigActions.DISABLE):
-        # Apply the enable/disable action to the avahi socket AFTER the service
-        # unit, because a connected socket could interrupt stop
-        simple_systemd(action, "avahi-daemon.socket")
-
-    return return_value
-
-
 def configure_bluetooth(action: ConfigActions):
     hci_device = join(LINUX_BT_CLASS_PATH, "hci0")
     bt_rfkill_index = get_rfkill_index(hci_device)
@@ -509,7 +581,17 @@ def configure_con_can(action: ConfigActions):
 
 
 def configure_dphys_swapfile(action: ConfigActions):
-    return_value = simple_systemd(action, "dphys-swapfile.service")
+    # Translate config action to systemd action
+    if action is ConfigActions.ENABLE:
+        systemd_action = ServiceActions.ENABLE
+    elif action is ConfigActions.DISABLE:
+        systemd_action = ServiceActions.DISABLE
+    elif action is ConfigActions.STATUS:
+        systemd_action = ServiceActions.STATUS
+    else:
+        systemd_action = ServiceActions.AVAILABLE
+
+    return_value = simple_systemd(systemd_action, "dphys-swapfile.service")
 
     # Post actions for dphys-swapfile
     if action is ConfigActions.DISABLE:
@@ -634,98 +716,6 @@ def get_rfkill_index(device_class_path: str) -> Optional[int]:
     return None
 
 
-def simple_systemd(action: ConfigActions, unit: str):
-    """
-    Performs specified actions on systemd units.
-
-    This function allows interaction with systemd units for various operations
-    such as enabling, disabling, checking the status, and verifying availability.
-    It communicates with the systemd manager via the SystemBus and handles units
-    based on the action specified.
-
-    Parameters:
-        action (ConfigActions): Specifies the action to be performed on the
-                                systemd unit. Supported actions include ENABLE,
-                                DISABLE, STATUS, and AVAILABLE.
-        unit (str): The name of the systemd unit on which the action is to be
-                    performed.
-
-    Returns:
-        bool: For STATUS and AVAILABLE actions, returns True if the corresponding
-              criteria are met (e.g., enabled and active for STATUS, or not found
-              for AVAILABLE). Otherwise, returns False.
-
-    Raises:
-        ValueError: If the specified action is not supported.
-    """
-    bus = SystemBus()
-    systemd = bus.get(
-        "org.freedesktop.systemd1",
-        "/org/freedesktop/systemd1",
-    )
-    systemd_manager = systemd["org.freedesktop.systemd1.Manager"]
-
-    if action is ConfigActions.ENABLE:
-
-        def thread_unit_config():
-            """Change configuration asynchronously."""
-            # Dbus call: UnmaskUnitFiles(in as files, in b runtime, out a(sss) changes
-            lst_change_unmask = systemd_manager.UnmaskUnitFiles([unit], False)
-
-            # Dbus call: EnableUnitFiles(in as files, in b runtime, in b force,
-            #                            out b carries_install_info, out a(sss) changes
-            lst_change_enable = systemd_manager.EnableUnitFiles([unit], False, False)
-            if lst_change_unmask or lst_change_enable:
-                # Reload systemd after modified unit property
-                systemd_manager.Reload()
-
-        Thread(target=thread_unit_config, daemon=True).start()
-
-        # Dbus call: StartUnit(in s name, in s mode, out o job
-        systemd_manager.StartUnit(unit, "replace")
-
-    elif action is ConfigActions.DISABLE:
-
-        def thread_unit_config():
-            """Change configuration asynchronously."""
-            # Dbus call: DisableUnitFiles (in as files, in b runtime, out a(sss) changes)
-            change = systemd_manager.DisableUnitFiles([unit], False)
-            if change:
-                # Reload systemd after modified unit property
-                systemd_manager.Reload()
-
-        Thread(target=thread_unit_config, daemon=True).start()
-
-        # Dbus call: StopUnit(in s name,in s mode, out o job
-        systemd_manager.StopUnit(unit, "replace")
-
-
-    elif action is ConfigActions.STATUS:
-        try:
-            unit_path = systemd_manager.LoadUnit(unit)
-            properties = bus.get("org.freedesktop.systemd1", unit_path)
-        except Exception:
-            log.warning(f"could not get systemd unit {unit}")
-            return False
-
-        return properties.UnitFileState == "enabled" and properties.ActiveState == "active"
-
-    elif action is ConfigActions.AVAILABLE:
-        try:
-            unit_path = systemd_manager.LoadUnit(unit)
-            properties = bus.get("org.freedesktop.systemd1", unit_path)
-        except Exception:
-            log.warning(f"could not get systemd unit {unit}")
-            return False
-
-        return properties.LoadState != "not-found"
-
-    else:
-        raise ValueError(f"action {action} not supported")
-
-    return None
-
-
 if __name__ == "__main__":
     rc = RevPiConfig()
     print("Model:", rc.model)

src/revpi_middleware/dbus_middleware1/systemd_helper.py

@@ -0,0 +1,121 @@
+# -*- coding: utf-8 -*-
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH
+# SPDX-License-Identifier: GPL-2.0-or-later
+from enum import Enum
+from logging import getLogger
+from threading import Thread
+from typing import Optional
+
+from pydbus import SystemBus
+
+log = getLogger(__name__)
+
+
+class ServiceActions(Enum):
+    """
+    Enumeration class for defining configuration actions.
+
+    This enumeration provides predefined constants for common configuration
+    actions. It can be used to ensure consistency when working with or defining
+    such actions in a system.
+    """
+
+    ENABLE = "enable"
+    DISABLE = "disable"
+    STATUS = "status"
+    AVAILABLE = "available"
+
+
+def simple_systemd(action: ServiceActions, unit: str, unmask: bool = False) -> Optional[bool]:
+    """
+    Perform systemd service actions such as enable, disable, check status, or availability.
+
+    This function interacts with the systemd D-Bus API to manage and query the
+    state of services on a system. The supported actions include enabling a systemd
+    unit, disabling it, starting/stopping a unit, and checking its status or
+    availability. The function supports asynchronous configuration changes through
+    threads where applicable.
+
+    Parameters:
+        action (ServiceActions): The action to perform on the systemd service.
+            Supported actions are ENABLE, DISABLE, STATUS, and AVAILABLE.
+        unit (str): The name of the systemd unit to operate on (e.g., "example.service").
+        unmask (bool): When enabling a unit, if True, any masked unit file will
+            first be unmasked before proceeding with the operation. Defaults to False.
+
+    Returns:
+        Optional[bool]: The return value depends on the action. For STATUS or
+            AVAILABLE actions, it returns True if the unit satisfies the condition
+            (e.g., enabled and active, or available and loaded), False otherwise.
+            For other actions, it returns None.
+    """
+    bus = SystemBus()
+    systemd = bus.get(
+        "org.freedesktop.systemd1",
+        "/org/freedesktop/systemd1",
+    )
+    systemd_manager = systemd["org.freedesktop.systemd1.Manager"]
+
+    if action is ServiceActions.ENABLE:
+
+        def thread_unit_config():
+            """Change configuration asynchronously."""
+            lst_change_unmask = []
+            if unmask:
+                # Dbus call: UnmaskUnitFiles(in as files, in b runtime, out a(sss) changes
+                lst_change_unmask = systemd_manager.UnmaskUnitFiles([unit], False)
+
+            # Dbus call: EnableUnitFiles(in as files, in b runtime, in b force,
+            #                            out b carries_install_info, out a(sss) changes
+            lst_change_enable = systemd_manager.EnableUnitFiles([unit], False, False)
+            if lst_change_unmask or lst_change_enable:
+                # Reload systemd after modified unit property
+                systemd_manager.Reload()
+
+        Thread(target=thread_unit_config, daemon=True).start()
+
+        # Dbus call: StartUnit(in s name, in s mode, out o job
+        systemd_manager.StartUnit(unit, "replace")
+
+    elif action is ServiceActions.DISABLE:
+
+        def thread_unit_config():
+            """Change configuration asynchronously."""
+            # Dbus call: DisableUnitFiles (in as files, in b runtime, out a(sss) changes)
+            change = systemd_manager.DisableUnitFiles([unit], False)
+            if change:
+                # Reload systemd after modified unit property
+                systemd_manager.Reload()
+
+        Thread(target=thread_unit_config, daemon=True).start()
+
+        # Dbus call: StopUnit(in s name,in s mode, out o job
+        systemd_manager.StopUnit(unit, "replace")
+
+    elif action is ServiceActions.STATUS:
+        try:
+            unit_path = systemd_manager.LoadUnit(unit)
+            properties = bus.get("org.freedesktop.systemd1", unit_path)
+        except Exception:
+            log.warning(f"could not get systemd unit {unit}")
+            return False
+
+        return properties.UnitFileState == "enabled" and properties.ActiveState in (
+            "active",
+            "activating",
+        )
+
+    elif action is ServiceActions.AVAILABLE:
+        try:
+            unit_path = systemd_manager.LoadUnit(unit)
+            properties = bus.get("org.freedesktop.systemd1", unit_path)
+        except Exception:
+            log.warning(f"could not get systemd unit {unit}")
+            return False
+
+        return properties.LoadState != "not-found"
+
+    else:
+        raise ValueError(f"action {action} not supported")
+
+    return None