public void TryConsumeSynPacketWithOptions()
{
var span = _tcpSynPacketWithOptions.AsSpan();
Assert.True(TcpHeaderWithOptions.TryConsume(span, out var header, out var data));
Assert.True(header.SackPermitted);
Assert.Equal(1460, header.MaximumSegmentSize);
Assert.Equal(2, header.WindowScale);
}
public void ProcessPacket(TcpHeaderWithOptions header, ReadOnlySpan <byte> data)
{
// If there is backpressure just drop the packet
if (!_flushTask.IsCompleted)
{
return;
}
_echoTimestamp = header.TimeStamp;
switch (_state)
{
case TcpConnectionState.Listen:
_maxSegmentSize = header.MaximumSegmentSize <= 50 || header.MaximumSegmentSize > 1460 ? 1460 : header.MaximumSegmentSize;
_sendSequenceNumber = GetRandomSequenceStart();
_receiveSequenceNumber = header.Header.SequenceNumber;
// We know we checked for syn in the upper layer so we can ignore that for now
_partialTcpHeader = Network.Header.Tcp.Create((ushort)LocalPort, (ushort)RemotePort);
WriteSyncAckPacket();
_state = TcpConnectionState.Syn_Rcvd;
break;
case TcpConnectionState.Syn_Rcvd:
if (header.Header.SYN)
{
//Console.WriteLine("Another Syn made");
return;
}
_connectionDispatcher.OnConnection(this);
var ignore = TransmitLoop();
_state = TcpConnectionState.Established;
break;
case TcpConnectionState.Established:
if (header.Header.FIN)
{
_receiveSequenceNumber++;
_state = TcpConnectionState.Fin_Wait_1;
return;
}
if (header.Header.RST)
{
//Console.WriteLine("Got RST Should shut down!");
return;
}
// First lets update our acked squence number;
_sendAckSequenceNumber = header.Header.AcknowledgmentNumber;
if (_receiveSequenceNumber != header.Header.SequenceNumber)
{
// We are just going to drop this and wait for a resend
return;
}
unchecked { _receiveSequenceNumber += (uint)data.Length; }
var output = Input.GetMemory(data.Length);
data.CopyTo(output.Span);
Input.Advance(data.Length);
// need to do something with the task and make sure we don't overlap the writes
var task = Input.FlushAsync();
if (!task.IsCompleted)
{
_flushTask = task.AsTask();
}
PendingAck = true;
_totalBytesWritten += data.Length;
break;
case TcpConnectionState.Fin_Wait_1:
case TcpConnectionState.Fin_Wait_2:
break;
default:
throw new NotImplementedException($"Unknown tcp state?? {_state}");
}
}
public void BadPacket()
{
Assert.True(TcpHeaderWithOptions.TryConsume(_tcpActualDataPacket.AsSpan(), out var header, out var data));
}
