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

Hello,

On Tue, Mar 6, 2018 at 11:05 AM, Eggert, Lars <lars@netapp.com> wrote:

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

I think the observation of the bug can go into 793bis (which has been done
in the current version).
However, I think the solution for it needs to be reviewed and discussed.

It will be really great if some implementers speak up if the solution in
the draft looks good or they take different approach to address the issue.
--
Yoshi

>
> On 2018-3-6, at 19:38, Fernando Gont <fgont@si6networks.com> 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: internet-drafts@ietf.org
> > To: Fernando Gont <fgont@si6networks.com>, David Borman
> > <david.borman@quantum.com>
> >
> >
> > 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-se
> q-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
> >
> >
> >
> > _______________________________________________
> > tcpm mailing list
> > tcpm@ietf.org
> > https://www.ietf.org/mailman/listinfo/tcpm
>
>
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