Re: [tcpm] Flaw in RFC793 (Fwd: New Version Notification for draft-gont-tcpm-tcp-seq-validation-03.txt)

["Eggert, Lars" <[e-mail]>]

Hi,

isn't this something that could simply go into 793bis, after there is consensus that something needs to be fixed?

Lars

On 2018-3-6, at 19:38, Fernando Gont <[e-mail]> wrote:
> 
> Folks,
> 
> There is bug in the TCP Sequence Number validation algorithm from
> RFC793. Most major implementations have addressed it, but the bug still
> remains in our specs.
> 
> We got a bit of extra energy to try to get this one fixed. Our I-D
> (draft-gont-tcpm-tcp-seq-validation) is available at the usual repository.
> 
> We have incorporated some minor edits done after the cut-off here:
> <https://www.si6networks.com/publications/drafts/draft-gont-tcpm-tcp-seq-validation-04.txt>
> -- but modulo minor grammar corrections, version -03 is the same.
> 
> We'd like to receive feedback from the wg regarding the "problem
> statement" (so to speak), and the proposed/described fixes.
> 
> Thanks!
> 
> Cheers,
> Fernando
> 
> 
> 
> 
> -------- Forwarded Message --------
> Subject: New Version Notification for
> draft-gont-tcpm-tcp-seq-validation-03.txt
> Date: Mon, 05 Mar 2018 15:43:15 -0800
> From: [e-mail]
> To: Fernando Gont <[e-mail]>, David Borman
> <[e-mail]>
> 
> 
> A new version of I-D, draft-gont-tcpm-tcp-seq-validation-03.txt
> has been successfully submitted by Fernando Gont and posted to the
> IETF repository.
> 
> Name:		draft-gont-tcpm-tcp-seq-validation
> Revision:	03
> Title:		On the Validation of TCP Sequence Numbers
> Document date:	2018-03-05
> Group:		Individual Submission
> Pages:		16
> URL:
> https://www.ietf.org/internet-drafts/draft-gont-tcpm-tcp-seq-validation-03.txt
> Status:
> https://datatracker.ietf.org/doc/draft-gont-tcpm-tcp-seq-validation/
> Htmlized:
> https://tools.ietf.org/html/draft-gont-tcpm-tcp-seq-validation-03
> Htmlized:
> https://datatracker.ietf.org/doc/html/draft-gont-tcpm-tcp-seq-validation-03
> Diff:
> https://www.ietf.org/rfcdiff?url2=draft-gont-tcpm-tcp-seq-validation-03
> 
> Abstract:
>   When TCP receives packets that lie outside of the receive window, the
>   corresponding packets are dropped and either an ACK, RST or no
>   response is generated due to the out-of-window packet, with no
>   further processing of the packet.  Most of the time, this works just
>   fine and TCP remains stable, especially when a TCP connection has
>   unidirectional data flow.  However, there are three scenarios in
>   which packets that are outside of the receive window should still
>   have their ACK field processed, or else a packet war will take place.
>   The aforementioned issues have affected a number of popular TCP
>   implementations, typically leading to connection failures, system
>   crashes, or other undesirable behaviors.  This document describes the
>   three scenarios in which the aforementioned issues might arise, and
>   formally updates RFC 793 such that these potential problems are
>   mitigated.
> 
> 
> 
> 
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at tools.ietf.org.
> 
> The IETF Secretariat
> 
> 
> 
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