From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gilad Ben-Yossef Subject: Re: [PATCH v2 1/8] Only parse time stamp TCP option in time wait sock Date: Wed, 21 Oct 2009 12:07:33 +0200 Message-ID: <4ADEDD65.6070802@codefidence.com> References: <1256115421-12714-1-git-send-email-gilad@codefidence.com> <1256115421-12714-2-git-send-email-gilad@codefidence.com> <4ADED915.7000107@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: William Allen Simpson Return-path: Received: from xenbox.codefidence.com ([92.48.73.16]:38153 "EHLO xenbox.codefidence.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753243AbZJUKHc (ORCPT ); Wed, 21 Oct 2009 06:07:32 -0400 In-Reply-To: <4ADED915.7000107@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: William Allen Simpson wrote: > Gilad Ben-Yossef wrote: >> A time wait socket is established - we already know if time stamp >> option is called for or not. >> > Not so sure about this. A timewait sock isn't actually established, > and new/changed options could appear. There's all sorts of edge cases. If you examine the specific context where tcp_parse_options is being called here, the only TCP option which is of interest is the time stamp option, and this code path is only being taken when we already know that the original socket had used the time stamp option. So while I agree that in general you are right, I do believe that in the specific context of this patch we should call tcp_parse_options with the established flag on and let it know we are expecting to see a time stamp option, which is what I was referring to. > > There's also some current work to note: > > http://tools.ietf.org/html/draft-ietf-tcpm-1323bis > > http://tools.ietf.org/html/draft-gont-tcpm-tcp-timestamps Very interesting, thank you. As I noted above, my comment about TIME WAIT sockets being "established" should really only be considered in the context of the specific call to tcp_parse_options() and the "established" parameter of that function. Thanks, Gilad -- Gilad Ben-Yossef Chief Coffee Drinker & CTO Codefidence Ltd. Web: http://codefidence.com Cell: +972-52-8260388 Skype: gilad_codefidence Tel: +972-8-9316883 ext. 201 Fax: +972-8-9316884 Email: gilad@codefidence.com Check out our Open Source technology and training blog - http://tuxology.net "Sorry cannot parse this, its too long to be true :)" -- Eric Dumazet on netdev mailing list