public int Send(ConnectionState state, byte[] data)
{
if (!Connected)
{
Log("Cannot send in state 'not connected'");
return(-1);
}
TPKT resPkt = new TPKT();
TPDU resPdu = new TPDU();
if (data.Length <= m_MaxTPDUSize)
{
// No fragmentation
resPdu.MakeDataPacket(data);
resPkt.SetPayload(resPdu.GetBytes());
TCPSend(state, resPkt.GetBytes());
}
else
{
// With fragmentation
int workedLength = 0;
int fragLength;
bool lastDataUnit;
while (workedLength < data.Length)
{
fragLength = data.Length - workedLength;
if (fragLength > m_MaxTPDUSize)
{
fragLength = m_MaxTPDUSize;
lastDataUnit = false;
}
else
{
lastDataUnit = true;
}
resPdu.MakeDataPacket(data, workedLength, fragLength, lastDataUnit);
resPkt.SetPayload(resPdu.GetBytes());
TCPSend(state, resPkt.GetBytes());
workedLength += fragLength;
}
}
return(0);
}
public void Process(IsoServiceProvider client, byte[] inPacket, int len)
{
int workedLen;
TPKT PKT;
TPDU PDU;
byte[] packet = new byte[len];
Array.Copy(inPacket, packet, len);
workedLen = 0;
while (workedLen < len)
{
PKT = new TPKT(packet, len);
PDU = new TPDU(PKT.Payload);
switch (PDU.PDUType)
{
case (byte)TPDU.TPDU_TYPES.CR:
{
if (Connected)
{
break;
}
TPKT resPkt = new TPKT();
TPDU resPdu = new TPDU();
resPdu.PDUType = (byte)TPDU.TPDU_TYPES.CC;
Connected = false;
m_payloadFragmentData = new MemoryStream(1024); // Stream for TPDU fragments, S7 PDU has max. 960 bytes
// get connect confirm, if tsaps not equal a exception is thrown
try
{
resPdu.PduCon = PDU.PduCon.HandleConnectRequest(LocalTsaps, m_ProposedMaxTPDUSize, EnableLocalTsapCheck);
// Add TPDU to TPKT
resPkt.SetPayload(resPdu.GetBytes());
// send connect confirm
TCPSend(client.client, resPkt.GetBytes());
Connected = true;
m_MaxTPDUSize = resPdu.PduCon.GetMaxTPDUSize();
}
catch (Exception)
{
}
}
break;
case (byte)TPDU.TPDU_TYPES.DT:
{
if (!Connected)
{
Log("DT packet before state 'connected' received.");
m_payloadFragmentData.SetLength(0);
break;
}
// Handle DT TPDU fragments
if (PDU.PduData.EOT == false)
{
m_payloadFragmentData.Write(PDU.PduData.Payload, 0, PDU.PduData.Payload.Length);
}
else
{
if (m_payloadFragmentData.Length == 0)
{
OnReceived(client, PDU.PduData.Payload);
}
else
{
m_payloadFragmentData.Write(PDU.PduData.Payload, 0, PDU.PduData.Payload.Length);
byte[] payload = new byte[m_payloadFragmentData.Length];
payload = m_payloadFragmentData.ToArray();
OnReceived(client, payload);
m_payloadFragmentData.SetLength(0);
}
}
}
break;
case (byte)TPDU.TPDU_TYPES.DR:
// Disconnect Request
client.client.EndConnection();
break;
default:
Log("Cannot handle pdu type " + PDU.PDUType);
break;
}
// Build next packet to work on
workedLen += PKT.Length;
Array.Copy(inPacket, workedLen, packet, 0, len - workedLen);
}
}