Qt/C++ : How to get remote PC (communication peer) MAC address?

Question

I am using Qt5 on Windows 7.
In my application (TCP server), I am currently using some methods from QTcpSocket class:
- QAbstractSocket::peerAddress() in order to get the peer address;
- QAbstractSocket::peerPort() in order to get the peer port.

I would also want to get the MAC address of the communication peer.
Is this possible, without using a custom protocol (i.e. without having to exchange some custom messages between my app and the peer)? If yes, how?

Late Edit: There is now a very good solution - that I implemented few months ago. I tested it in the meantime and it works 100% flawlessly. Enjoy :)

Answer 1

Here is the code to get the MAC address of the communication peer.
Under the hood, it uses the Windows command arp.
Using Qt5.8, tested on Windows 7:

QString getMacForIP(QString ipAddress)
{
    QString MAC;
    QProcess process;
    //
    process.start(QString("arp -a %1").arg(ipAddress));
    if(process.waitForFinished())
    {
        QString result = process.readAll();
        QStringList list = result.split(QRegularExpression("\\s+"));
        if(list.contains(ipAddress))
            MAC = list.at(list.indexOf(ipAddress) + 1);
    }
    //
    return MAC;
}

Remark: remote peer must be on the same LAN.
Another remark: you'll get an empty string for MAC if the IP address is not present.