RE: [tcpm] TCP zero window timeout?

"Caitlin Bestler" <caitlinb@broadcom.com> Tue, 29 August 2006 19:34 UTC

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Subject: RE: [tcpm] TCP zero window timeout?
Date: Tue, 29 Aug 2006 12:34:15 -0700
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From: "Caitlin Bestler" <caitlinb@broadcom.com>
To: "MURALI BASHYAM" <murali_bashyam@yahoo.com>, "Ted Faber" <faber@ISI.EDU>
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MURALI BASHYAM wrote:
> --- Caitlin Bestler <caitlinb@broadcom.com> wrote:
> 
>> MURALI BASHYAM wrote:
>> 
>>>> 
>>> 
>>> I think the crux of the issue here is that this is left to
>>> the client side application control which means open game for
>>> hackers. 
>>> 
>>> Murali
>> 
>> I think it is a given that a server application can terminate the
>> connection to any client if the behaviour of that client means that
>> the server no longer wishes to maintain the connection.
>> 
> 
> The application is not aware of the client's behaviour here
> and as far as he is concerned the data is out of his control.
> 
>> I am not aware of any RFC that would impair the ability of the server
>> application to interact with the local TCP stack to achieve these
>> results.
> 
> Are u suggesting that the application query TCP to determine
> that the connection is stuck in persist state and how much of
> the data has been sent or not and so on? That sounds a little
> roundabout and complicated...

And/or the application convey an application specific tolerance
for such a state through a local interface.

If the behavior can be corrected through a local interface,
and there is no IETF language barring or discouraging such
an interface, then why is this something that TCPM should
consider?

At first glance, John Hefner's post would seem to show that
the required information is already available.

The nature of the Denial of Service attack presented does
not seem to require real-time defenses and definitely does
not present a strong case for any network element modifying
their "fast path" handling of packets.


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