[RESOLVED] Make TCPListener wait for full command

[chris128]

OK I am probably going to completely fail but I thought I would just try making an SMTP server (which came from another thread on here I was posting in earlier). At the moment I am just concentrating on RECEIVING emails via SMTP, I dont care about sending them yet.

So the first thing I want to do is just make my server program be able to receive a simple HELO command from Telnet on port 25. Simple enough eh? Apparently not

The problem I have is that my program starts reading the data as soon as 1 character is typed into telnet, rather than it waiting for the telnet user to press Enter before it starts to process the command. I've had a look around and looked at Athiest's examples but cant figure out how to make it wait. Here is what I have so far:

Private Sub StartBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles StartBtn.Click
        Dim bgthread As New Threading.Thread(AddressOf StartServer)
        bgthread.IsBackground = True
        bgthread.Start()
    End Sub
 
    ''' <summary>
    ''' Starts listening on port 25
    ''' </summary>
    Private Sub StartServer()
        Dim TListener As New TcpListener(Net.IPAddress.Any, 25)
        TListener.Start()
        Dim TClient As TcpClient
 
        Do
            TClient = TListener.AcceptTcpClient()
            Invoke(New Action(Of String)(AddressOf WriteToLog), TClient.Client.RemoteEndPoint.ToString & " Connected")
            WriteToClientStream(TClient.GetStream, "Hello from SMTP Server!")
 
            '<This is where I am struggling>
            Dim DataAsBytes(1024) As Byte
            TClient.GetStream.Read(DataAsBytes, 0, 1024) '<-- This line executes as soon as one character is typed in telnet
            Dim DataAsString As String = System.Text.Encoding.ASCII.GetString(DataAsBytes)
            Invoke(New Action(Of String)(AddressOf WriteToLog), DataAsString)
            '</Struggle>
        Loop
 
    End Sub
 
    ''' <summary>
    ''' Writes a message back to the client's stream.
    ''' If the client is a telnet client then this message will appear in the telnet console
    ''' </summary>
    ''' <param name="stream">The underlying stream to write to</param>
    ''' <param name="msg">The string to write to the stream</param>
    Private Sub WriteToClientStream(ByVal stream As IO.Stream, ByVal msg As String)
        Dim Writer As New IO.StreamWriter(stream)
        Writer.WriteLine(msg)
        Writer.Flush()
    End Sub
 
    ''' <summary>
    ''' Writes to the log file (currently just an RTB on screen)
    ''' </summary>
    ''' <param name="msg">The string to write to the log</param>
    Private Sub WriteToLog(ByVal msg As String)
        logbox.AppendText(msg & vbNewLine)
    End Sub

See the comments in the StartServer sub for info on where exactly the problem is.

Any ideas?

Thanks
Chris