Add basic modem device support

The modem device will have hardcoded capability which make it
compatible with GSM connection settings.
It will be seen with hardcoded ModemManager manager dbus object path
for the UDI property.
Add also a dbus test method to add the modem device.

Signed-off-by: Frederic Martinsons <frederic.martinsons@sigfox.com>

tools/test-networkmanager-service.py

@@ -391,6 +391,7 @@ IFACE_SETTINGS = "org.freedesktop.NetworkManager.Settings"
 IFACE_AGENT_MANAGER = "org.freedesktop.NetworkManager.AgentManager"
 IFACE_AGENT = "org.freedesktop.NetworkManager.SecretAgent"
 IFACE_WIRED = "org.freedesktop.NetworkManager.Device.Wired"
+IFACE_MODEM = "org.freedesktop.NetworkManager.Device.Modem"
 IFACE_VLAN = "org.freedesktop.NetworkManager.Device.Vlan"
 IFACE_WIFI_AP = "org.freedesktop.NetworkManager.AccessPoint"
 IFACE_ACTIVE_CONNECTION = "org.freedesktop.NetworkManager.Connection.Active"
@@ -843,8 +844,13 @@ class Device(ExportedObj):
 
         self.prp_state = NM.DeviceState.UNAVAILABLE
 
+        if devtype == NM.DeviceType.MODEM:
+            udi = "/org/freedesktop/ModemManager1/Modem/0"
+        else:
+            udi = "/sys/devices/virtual/%s" % iface
+
         props = {
-            PRP_DEVICE_UDI: "/sys/devices/virtual/%s" % (iface),
+            PRP_DEVICE_UDI: udi,
             PRP_DEVICE_IFACE: iface,
             PRP_DEVICE_DRIVER: "virtual",
             PRP_DEVICE_STATE: dbus.UInt32(self.prp_state),
@@ -1112,6 +1118,30 @@ class WiredDevice(Device):
         pass
 
 
+###############################################################################
+PM_CURRENT_CAPABILITIES = "CurrentCapabilities"
+PM_MODEM_CAPABILITIES = "ModemCapabilities"
+
+# capability to make device seen compatible with GSM connection
+NM_DEVICE_MODEM_CAPABILITY_GSM_UMTS = 0x00000004
+
+
+class ModemDevice(Device):
+    def __init__(self, iface):
+        Device.__init__(self, iface, NM.DeviceType.MODEM)
+
+        props = {
+            PM_CURRENT_CAPABILITIES: dbus.UInt32(NM_DEVICE_MODEM_CAPABILITY_GSM_UMTS),
+            PM_MODEM_CAPABILITIES: dbus.UInt32(0),
+        }
+
+        self.dbus_interface_add(IFACE_MODEM, props, ModemDevice.PropertiesChanged)
+
+    @dbus.service.signal(IFACE_MODEM, signature="a{sv}")
+    def PropertiesChanged(self, changed):
+        pass
+
+
 ###############################################################################
 
 PRP_VLAN_HW_ADDRESS = "HwAddress"
@@ -1807,6 +1837,11 @@ class NetworkManager(ExportedObj):
         dev = WiredDevice(ifname, mac, subchannels)
         return ExportedObj.to_path(self.add_device(dev))
 
+    @dbus.service.method(IFACE_TEST, in_signature="s", out_signature="o")
+    def AddModemDevice(self, ifname):
+        dev = ModemDevice(ifname)
+        return ExportedObj.to_path(self.add_device(dev))
+
     @dbus.service.method(IFACE_TEST, in_signature="s", out_signature="o")
     def AddWifiDevice(self, ifname):
         dev = WifiDevice(ifname)