QUdpSocket Rebroadcaster

webzoid

I'm developing a simple tray application which acts as a UDP socket re-broadcaster.

One thing I have realised is that as I'm listening for UDP broadcasts, any re-broadcast sent out from my application is automatically picked up again and then re-broadcasted again and again and again.

The setup code I have is as follows is:

// Create a QUdpSocket to listen for Oculus status messages
m_listener = new QUdpSocket(this);
connect(m_listener, SIGNAL(readyRead()), this, SLOT(readDatagrams()));
m_listener->bind(52102, QUdpSocket::ShareAddress | QUdpSocket::ReuseAddressHint);

The code to read and re-broadcast is as follows:

// Read through any available datagrams
while (m_listener->hasPendingDatagrams())
{
    // Read the datagram out of the socket buffer
    QByteArray rx;

    rx.resize(m_listener->pendingDatagramSize());
    m_listener->readDatagram(rx.data(), rx.size());

    // Validate and modify the UDP packet...

    m_listener->writeDatagram(rx, QHostAddress::Broadcast, 52102);
}

One possible solution could be to disconnect the readyRead signal during the writeDatagram phase so that it is not re-received by my application but this seems a little numb. Another possible solution would be to check the "source IP" address during the readyRead slot.

Are there any better solutions?

VRonin

instead of using m_listener->readDatagram you could use m_listener->receiveDatagram that contains the sender address. then just compare the sender address with yours and if they are the same ignore it