Re: [PATCHv2] sctp: ABORT if receive queue is not empty while closing socket

[Thomas Graf <tgraf@infradead.org>]

On Fri, Jul 08, 2011 at 09:49:52AM -0400, Vladislav Yasevich wrote:
> On 07/08/2011 06:57 AM, Thomas Graf wrote:
> > Trigger user ABORT if application closes a socket which has data
> > queued on the socket receive queue as this would imply data being
> > lost which defeats the point of a graceful shutdown.
> > 
> > This behavior is already practiced in TCP.
> > 
> > We do not check the input queue because that would mean to parse
> > all chunks on it to look for unacknowledged data which seems too
> > much of an effort. Control chunks or duplicated chunks may also
> > be in the input queue and should not be stopping a graceful
> > shutdown.
> 
> I think you need to check the ulpq as well.
> 
> It is possible to have a condition where you only have data
> in the ulpq (imagine a few lost out of order packets or a few lost
> fragments from very large messages).  In those circumstances, either fragmentation
> or ordering queues may consume all of the window (especially if the buffer was
> set small) and you would never trigger the abort.

Good point. Updating the patch.