netdev - Re: [PATCH 3/5] netfilter: xt_TCPMSS: Fix violation of RFC879 in absence of MSS option

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 10 Jun 2013 03:19:54 -0400
From:	Phil Oester <kernel@...uxace.com>
To:	David Laight <David.Laight@...LAB.COM>
Cc:	Pablo Neira Ayuso <pablo@...filter.org>,
	netfilter-devel@...r.kernel.org, davem@...emloft.net,
	netdev@...r.kernel.org
Subject: Re: [PATCH 3/5] netfilter: xt_TCPMSS: Fix violation of RFC879 in
 absence of MSS option

On Tue, Jun 11, 2013 at 09:43:07AM +0100, David Laight wrote:
> Is setting the mss to 536 actually ever sensible?
> RFC 879 might say that it is the default (and the minimum
> that must be supported), but in practise the actual mss
> is very likely to be only slightly shorter than the standard
> ethernet mss.
> Although strict conformance with RFC 879 might require the mss
> be clamped to 536, pragmatically a value much nearer 1400 would
> make sense - systems with very low mtu/mss are probably likely
> to advertise it.

Read the associated bugzilla - there was at least one real world
example where setting a higher MSS was causing breakage.

Phil

https://bugzilla.netfilter.org/show_bug.cgi?id=662
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html