QT DBUS NetworkManager get Address from IP4Config interface

Question

I have a question for StackOverflow. I have been using QtDBus and NetworkManager for a while but have run into a problem. I need to access the wifi devices IP address and the way to obtain it is to get the Wifi device object, get its IP4Config property (a QDbusObjectPath object) and then to get the AddressData . The problem is that as soon as I try to obtain the AddressData using the interfaces property method, my application crashes.

I believe I need to register a meta type (I have done this for other types) but cant seem to figure out how to unpack the aa{sv} data returned from the property. Using qdbusviewer I can see the data for the IP address.

Does anyone, or has anyone ever found how to get this information from the property? I have spent almost 1/2 day trying.

Here is a snippet of the code which is encountering the problem. It seems I can get the QString property of Gateway but as soon as I try to get the AddressData my process crashes (as shown below).

    cout << wifi_args.size() << endl;
    cout << wifi_args[0].path().toStdString() << endl;
    if (wifi_args.size() > 0) {

        QDBusInterface wifi_device(NM_DBUS_SERVICE, wifi_args[0].path(),
                                   NM_DBUS_INTERFACE_DEVICE,
                                   QDBusConnection::systemBus());

        const auto wifiInterface = wifi_device.property("Interface").toString();
        // auto wifiIPv4 = wifi_device.property("Ip4Address").toInt();
        auto ip4_config_path =
            qdbus_cast<QDBusObjectPath>(wifi_device.property("Ip4Config"));

        cout << "config path = " << ip4_config_path.path().toStdString()
             << endl;

        QDBusInterface wifi_ip4_if(NM_DBUS_SERVICE, ip4_config_path.path(),
                                   NM_DBUS_INTERFACE_IP4_CONFIG,
                                   QDBusConnection::systemBus());

        auto gateway = wifi_ip4_if.property("Gateway").toString();
        auto ipv4 = wifi_ip4_if.property("AddressData");

        // for (auto item : wifiIPv4) {
        //     cout << "Item";
        // }

        cout << "Interface = " << wifiInterface.toStdString() << endl;
        cout << "Gateway   = " << gateway.toStdString() << endl;
        // cout << "Address   = " << int_to_ipv4(wifiIPv4) << endl;
    } else {
        cerr << "ERROR: Multiple wifi devices found!" << endl;
    }

Here is the output from the run:

michael_uman@ThinkPad-X1-Carbon-7th ~/gitroot/UXHUB-development (development)$ ./build-host/app/kylixctl/kylixctl list wifi
1
/org/freedesktop/NetworkManager/Devices/3
config path = /org/freedesktop/NetworkManager/IP4Config/8
Cannot construct placeholder type QDBusRawType
Aborted (core dumped)

Any help will be greatly appreciated, if you don't know the answer, maybe you know someone who might? There has to be something i am missing here.

Thank you, Michael Uman

Sr Firmware Engineer

Cana Technology