private void HandleReceiveSequenceNumber(APdu aPdu)
{
if (acknowledgedSendSequenceNumber != aPdu.GetReceiveSeqNumber())
{
if (GetSequenceNumberDifference(aPdu.GetReceiveSeqNumber(), acknowledgedSendSequenceNumber) >
GetNumUnconfirmedIPdusSent())
{
throw new IOException("Got unexpected receive sequence number: " + aPdu.GetReceiveSeqNumber()
+ ", expected a number between: " + acknowledgedSendSequenceNumber + " and "
+ sendSequenceNumber);
}
if (maxTimeNoAckReceivedFuture != null)
{
maxTimeNoAckReceivedFuture.Cancel();
maxTimeNoAckReceivedFuture = null;
}
acknowledgedSendSequenceNumber = aPdu.GetReceiveSeqNumber();
if (sendSequenceNumber != acknowledgedSendSequenceNumber)
{
ScheduleMaxTimeNoAckReceivedFuture();
}
}
}
public void Send(ASdu aSdu)
{
acknowledgedReceiveSequenceNumber = receiveSequenceNumber;
var requestAPdu = new APdu(sendSequenceNumber, receiveSequenceNumber, APdu.ApciType.I_FORMAT, aSdu);
sendSequenceNumber = (sendSequenceNumber + 1) % 32768;
if (maxTimeNoAckSentFuture != null)
{
maxTimeNoAckSentFuture.Cancel();
maxTimeNoAckSentFuture = null;
}
if (maxTimeNoAckReceivedFuture == null)
{
ScheduleMaxTimeNoAckReceivedFuture();
}
var length = requestAPdu.Encode(buffer, settings);
writer.Write(buffer, 0, length);
writer.Flush();
ResetMaxIdleTimeTimer();
}
private void SendSFormatPdu()
{
var requestAPdu = new APdu(0, receiveSequenceNumber, APdu.ApciType.S_FORMAT, null);
requestAPdu.Encode(buffer, settings);
writer.Write(buffer, 0, 6);
writer.Flush();
acknowledgedReceiveSequenceNumber = receiveSequenceNumber;
ResetMaxIdleTimeTimer();
}
public override void Run()
{
try
{
var reader = innerConnection.reader;
while (true)
{
if (reader.ReadByte() != 0x68)
{
throw new IOException("Message does not start with 0x68");
}
var aPdu = new APdu(reader, innerConnection.settings);
switch (aPdu.GetApciType())
{
case APdu.ApciType.I_FORMAT:
if (innerConnection.receiveSequenceNumber != aPdu.GetSendSeqNumber())
{
throw new IOException("Got unexpected send sequence number: " +
aPdu.GetSendSeqNumber()
+ ", expected: " + innerConnection.receiveSequenceNumber);
}
innerConnection.receiveSequenceNumber = (aPdu.GetSendSeqNumber() + 1) % 32768;
innerConnection.HandleReceiveSequenceNumber(aPdu);
innerConnection.NewASdu?.Invoke(aPdu.GetASdu());
var numUnconfirmedIPdusReceived = innerConnection.GetSequenceNumberDifference(
innerConnection.receiveSequenceNumber,
innerConnection.acknowledgedReceiveSequenceNumber);
if (numUnconfirmedIPdusReceived > innerConnection.settings.MaxUnconfirmedIPdusReceived)
{
innerConnection.SendSFormatPdu();
if (innerConnection.maxTimeNoAckSentFuture != null)
{
innerConnection.maxTimeNoAckSentFuture.Cancel();
innerConnection.maxTimeNoAckSentFuture = null;
}
}
else
{
if (innerConnection.maxTimeNoAckSentFuture == null)
{
innerConnection.maxTimeNoAckSentFuture =
PeriodicTaskFactory.Start(() =>
{
innerConnection.SendSFormatPdu();
innerConnection.maxTimeNoAckSentFuture = null;
}, innerConnection.settings.MaxTimeNoAckSent);
}
}
innerConnection.ResetMaxIdleTimeTimer();
break;
case APdu.ApciType.STARTDT_CON:
innerConnection.startdtConSignal?.CountDown();
innerConnection.ResetMaxIdleTimeTimer();
break;
case APdu.ApciType.STARTDT_ACT:
innerConnection.startdtactSignal?.CountDown();
break;
case APdu.ApciType.S_FORMAT:
innerConnection.HandleReceiveSequenceNumber(aPdu);
innerConnection.ResetMaxIdleTimeTimer();
break;
case APdu.ApciType.TESTFR_ACT:
try
{
innerConnection.writer.Write(TestfrConBuffer, 0, TestfrConBuffer.Length);
innerConnection.writer.Flush();
}
catch (Exception e)
{
throw new IOException(e.Message);
}
innerConnection.ResetMaxIdleTimeTimer();
break;
case APdu.ApciType.TESTFR_CON:
if (innerConnection.maxTimeNoTestConReceivedFuture != null)
{
innerConnection.maxTimeNoTestConReceivedFuture.Cancel();
innerConnection.maxTimeNoTestConReceivedFuture = null;
}
innerConnection.ResetMaxIdleTimeTimer();
break;
default:
throw new IOException("Got unexpected message with APCI Type: " + aPdu.GetApciType());
}
}
}
catch (IOException e)
{
innerConnection.closedIoException = e;
}
catch (Exception e)
{
innerConnection.closedIoException = new IOException(e.Message);
}
finally
{
innerConnection.ConnectionClosed?.Invoke(innerConnection.closedIoException);
innerConnection.Close();
}
}