public static KnxNetTunnelingDatagram FromBytes(byte[] datagram)
{
if ((datagram == null) || (datagram.Length < 8))
{
Debug.WriteLine("Received parial datagram " + BitConverter.ToString(datagram));
return(null);
}
if (datagram[4] + datagram[5] != datagram.Length)
{
Debug.WriteLine("Datagram length validaton failed " + BitConverter.ToString(datagram));
return(null);
}
var header = new KnxNetTunnelingDatagram()
{
header_length = datagram[0],
protocol_version = datagram[1],
service_type = (ushort)((datagram[2] << 8) + datagram[3]),
total_length = datagram[4] + datagram[5],
channel_id = datagram[6],
status = datagram[7]
};
if (datagram.Length >= 10)
{
header.sequence_number = datagram[8];
header.data = new byte[datagram.Length - 10];
Array.Copy(datagram, 10, header.data, 0, header.data.Length);
}
return(header);
}
private void UdpClientDataReceived(object sender, Spark.Universal.Net.DataReceivedEventArgs e)
{
// parse datagram
byte[] datagram = e.Data;
var tt = KnxNetTunnelingDatagram.FromBytes(e.Data);
switch (tt.service_type)
{
case (ushort)KnxHelper.SERVICE_TYPE.CONNECT_RESPONSE:
this.ProcessConnectResponse(datagram);
break;
case (ushort)KnxHelper.SERVICE_TYPE.CONNECTIONSTATE_RESPONSE:
this.ProcessStateResponse(datagram);
break;
case (ushort)KnxHelper.SERVICE_TYPE.TUNNELLING_ACK:
this.ProcessTunnelingAck(datagram);
break;
case (ushort)KnxHelper.SERVICE_TYPE.DISCONNECT_REQUEST:
this.ProcessDisconnectRequest(datagram);
break;
case (ushort)KnxHelper.SERVICE_TYPE.TUNNELLING_REQUEST:
ProcessDatagramHeaders(datagram);
break;
}
}
private void ProcessDatagramHeaders(byte[] datagram)
{
// HEADER
// TODO: Might be interesting to take out these magic numbers for the datagram indices
var knxDatagram = new KnxNetTunnelingDatagram
{
header_length = datagram[0],
protocol_version = datagram[1],
service_type = (ushort)((datagram[2] << 8) + datagram[3]),
total_length = datagram[4] + datagram[5]
};
var channelId = datagram[7];
if (channelId != _channelId)
{
return;
}
var sequenceNumber = datagram[8];
var process = sequenceNumber > _rxSequenceNo;
_rxSequenceNo = sequenceNumber;
if (process)
{
// TODO: Magic number 10, what is it?
var cemiBytes = new byte[datagram.Length - 10];
Array.Copy(datagram, 10, cemiBytes, 0, datagram.Length - 10);
var knxCEMI = KnxCEMI.FromBytes(_threeLevelGroupAssigning, cemiBytes);
if (knxCEMI.IsEvent)
{
Debug.WriteLine("KNX Event " + knxCEMI.destination_address + " " + BitConverter.ToString(knxCEMI.apdu));
this.KnxEvent?.Invoke(this, new KnxEventArgs()
{
Address = knxCEMI.destination_address,
Data = knxCEMI.apdu
});
}
else if (knxCEMI.IsStatus)
{
Debug.WriteLine("KNX Status " + knxCEMI.destination_address + " " + BitConverter.ToString(knxCEMI.apdu));
this.KnxStatus?.Invoke(this, new KnxEventArgs()
{
Address = knxCEMI.destination_address,
Data = knxCEMI.apdu
});
}
}
this.SendTunnelingAck(sequenceNumber);
}
private void ProcessStateResponse(byte[] datagram)
{
var knxDatagram = KnxNetTunnelingDatagram.FromBytes(datagram);
if (knxDatagram == null)
{
return;
}
if (knxDatagram.status != 0x21)
{
return; /* TODO: status should be 0 */
}
this.Disconnect();
}
private void ProcessDisconnectRequest(byte[] datagram)
{
var knxDatagram = KnxNetTunnelingDatagram.FromBytes(datagram);
if (knxDatagram == null)
{
return;
}
if (knxDatagram.channel_id != _channelId)
{
return;
}
this.Disconnected?.Invoke(this, EventArgs.Empty);
}
private void ProcessConnectResponse(byte[] datagram)
{
// HEADER
var knxDatagram = KnxNetTunnelingDatagram.FromBytes(datagram);
if (knxDatagram == null)
{
return;
}
if (knxDatagram.channel_id == 0x00 && knxDatagram.status == 0x24) /* TODO: status should be 0 */
{
// no more connections available
return;
}
_channelId = knxDatagram.channel_id;
_sequenceNo = 0;
this.Connected?.Invoke(this, EventArgs.Empty);
}