From mboxrd@z Thu Jan 1 00:00:00 1970 From: Einar Lueck Subject: Re: [RFC PATCH V2] tcp: introduce raw access to experimental options Date: Tue, 08 Jan 2013 15:36:35 +0100 Message-ID: <50EC2EF3.5080506@linux.vnet.ibm.com> References: <1357575210-52926-1-git-send-email-elelueck@linux.vnet.ibm.com> <1357575210-52926-2-git-send-email-elelueck@linux.vnet.ibm.com> <1357577051.6919.3171.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, davem@davemloft.net, ubacher@de.ibm.com, raspl@de.ibm.com, frankbla@de.ibm.com, samudrala@us.ibm.com To: Eric Dumazet Return-path: Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:48399 "EHLO e06smtp13.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756428Ab3AHOgm (ORCPT ); Tue, 8 Jan 2013 09:36:42 -0500 Received: from /spool/local by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 8 Jan 2013 14:35:55 -0000 Received: from d06av01.portsmouth.uk.ibm.com (d06av01.portsmouth.uk.ibm.com [9.149.37.212]) by b06cxnps3075.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r08EaTbC55771238 for ; Tue, 8 Jan 2013 14:36:29 GMT Received: from d06av01.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av01.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r08EaaZN003649 for ; Tue, 8 Jan 2013 07:36:37 -0700 In-Reply-To: <1357577051.6919.3171.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On 01/07/2013 05:44 PM, Eric Dumazet wrote: > > Thats a big addition, and for example doesn't help if the SYNACK should > include an option that is depending on the content of SYN message. > > For TCP fastopen for example, the cookie we send to the client is not a > constant cookie. > > Also TCP coalescing of TCP collapse will merge several skbs, so storing > "the last received options" in the socket is kind of not well defined > semantic. > > It looks like you need to add hooks and kernel modules to fully use > experimental options, like congestion control modules. > > Thanks for the fast feedback, Eric. Let me try to make sure that I understand your suggestions correctly: You suggest to have a set of hooks that allow to move all code that exploits experimental options into dedicated modules (e.g. one module for TCP fastopen and one for cookies). Extensibility then comes on a per module granularity. Is my understanding correct? Thx, Einar.