From owner-freebsd-net@FreeBSD.ORG Tue Aug 21 16:17:57 2007 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4D0AD16A419 for ; Tue, 21 Aug 2007 16:17:57 +0000 (UTC) (envelope-from jacek@ipv6.jacek.it.pl) Received: from smtpauth.ipartners.pl (smtpauth3.ipartners.pl [IPv6:2001:4190:8002:1::270]) by mx1.freebsd.org (Postfix) with ESMTP id 8A26013C45E for ; Tue, 21 Aug 2007 16:17:56 +0000 (UTC) (envelope-from jacek@ipv6.jacek.it.pl) Received: from kx.jacek.it.pl (cl-158.mbx-01.si.sixxs.net [IPv6:2001:15c0:65ff:9d::2]) (authenticated bits=0) by smtpauth.ipartners.pl with ESMTP id l7LGHntF014505 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Tue, 21 Aug 2007 18:17:51 +0200 (CEST) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by kx.jacek.it.pl (Postfix) with ESMTP id CF36E5982AD; Tue, 21 Aug 2007 18:17:48 +0200 (CEST) From: Jacek Zapala To: Daniel Hartmeier In-Reply-To: <20070821145047.GC32421@insomnia.benzedrine.cx> References: <200708211010.l7LAA6V7082258@freefall.freebsd.org> <20070821121118.GF27160@insomnia.benzedrine.cx> <1187703472.22531.4.camel@localhost.localdomain> <20070821135048.GA32421@insomnia.benzedrine.cx> <1187705811.30269.5.camel@localhost.localdomain> <20070821143125.GB32421@insomnia.benzedrine.cx> <1187707117.846.3.camel@localhost.localdomain> <20070821145047.GC32421@insomnia.benzedrine.cx> Content-Type: text/plain Date: Tue, 21 Aug 2007 18:17:48 +0200 Message-Id: <1187713068.3973.6.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: kern/115413: [ipv6] ipv6 pmtu not working X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Aug 2007 16:17:57 -0000 On Tue, 2007-08-21 at 16:50 +0200, Daniel Hartmeier wrote: > Could you possibly try the patch below, and see if it fixes the > problem > (with rfc1323 enabled again)? > > We're accessing th_flags from the TCP header embedded in the ICMPv6 > packet, even though we only pulled up the first 8 bytes of the mbuf, > because the sender doesn't have to provide more of the header. > > There could be random garbage there, and the bit corresponding to > TH_SYN might be set, so the window scale factor is not applied. Not > sure > if that would be reproducable so reliably, but it sure is a bug ;) > I have applied the patch and it looks like it has helped. But I'm not sure if I understood well - you suspect that only 8 bytes of tcp header are copied from the original tcp packet to the icmp message by the router? TCP packet in the icmp message looks like almost complete (of course it is shorter than the original due to 1280 bytes icmp packet limit). I have captured that traffic so I can send you full packets if you would like to look at them. Jacek