On Wed, Dec 12, 2007 at 08:57:18PM -0500, Daniel Ouellet wrote:
> Otto Moerbeek wrote:
>> I did not follow the complete thread, but I like to mention one thing:
>> there might be half open connections involved here. A client might do a
>> half close (i.e. shutdown(SHUT_WR)) after sending
>> a request. This will make the connection a half-duplex one. iirc, after
>> the
>> shutdown, the server moves to CLOSE_WAIT, but will still be able to
>> send data to the client, until it decides that it is done and closes
>> down the connection.
>
> Thanks for your feedback Otto!
>
> I keep reading this and may be my English is not getting it fully. For my
> own knowledge and understanding, when you say half open and haft close. In
> both cases they needed and have done the full three step handshake or may
> be skip some of it?
>
> In other word they can or can't reach the CLOSE_WAIT without doing the full
> complete and proper three step handshake?
>
> I would appreciate to understand that for myself as I thought it was clear,
> but I guess I still have a gap unfill. (;>
I'm only talking about the tear-down. The three-way handshake happens
before that, both sockets are in ESTABSLIHED state. You have to read
half-close as a verb (action), and half-open as a description of the
state of the connection.
Check the state transition diagram, and maybe do some reading in
Stevens's TCP/Illustrated Volume I (which has the state diagram on the
inside cover ;-)
-Otto
