/// <summary>
/// Reads COTP TPDU (Transport protocol data unit) from the network stream
/// See: https://tools.ietf.org/html/rfc905
/// </summary>
/// <param name="stream">The socket to read from</param>
/// <returns>COTP DPDU instance</returns>
public static TPDU Read(Stream stream)
{
var tpkt = TPKT.Read(stream);
if (tpkt.Length == 0)
{
throw new TPDUInvalidException("No protocol data received");
}
return(new TPDU(tpkt));
}
/// <summary>
/// Reads COTP TPDU (Transport protocol data unit) from the network stream
/// See: https://tools.ietf.org/html/rfc905
/// </summary>
/// <param name="stream">The socket to read from</param>
/// <returns>COTP DPDU instance</returns>
public static async Task <TPDU> ReadAsync(Stream stream, CancellationToken cancellationToken)
{
var tpkt = await TPKT.ReadAsync(stream, cancellationToken).ConfigureAwait(false);
if (tpkt.Length == 0)
{
throw new TPDUInvalidException("No protocol data received");
}
return(new TPDU(tpkt));
}
public TPDU(TPKT tPKT)
{
TPkt = tPKT;
HeaderLength = tPKT.Data[0]; // Header length excluding this length byte
if (HeaderLength >= 2)
{
PDUType = (PduType)tPKT.Data[1];
if (PDUType == PduType.Data) //DT Data
{
var flags = tPKT.Data[2];
TPDUNumber = flags & 0x7F;
LastDataUnit = (flags & 0x80) > 0;
Data = new byte[tPKT.Data.Length - HeaderLength - 1]; // substract header length byte + header length.
Array.Copy(tPKT.Data, HeaderLength + 1, Data, 0, Data.Length);
return;
}
//TODO: Handle other PDUTypes
}
Data = new byte[0];
}