Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754946AbaDVIUI (ORCPT ); Tue, 22 Apr 2014 04:20:08 -0400 Received: from smtp.sgsi.ucl.ac.be ([130.104.5.67]:33128 "EHLO smtp6.sgsi.ucl.ac.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753229AbaDVIT7 (ORCPT ); Tue, 22 Apr 2014 04:19:59 -0400 X-Greylist: delayed 331 seconds by postgrey-1.27 at vger.kernel.org; Tue, 22 Apr 2014 04:19:59 EDT X-DKIM: Sendmail DKIM Filter v2.8.3 smtp6.sgsi.ucl.ac.be DF945183485 Date: Tue, 22 Apr 2014 10:14:19 +0200 From: Christoph Paasch To: Madhan Cc: "linux-kernel@vger.kernel.org" Subject: Re: tcp option added by driver Message-ID: <20140422081419.GA5460@cpaasch-mac> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Sgsi-Spamcheck: SASL authenticated, X-SGSI-MailScanner-ID: DF945183485.A06C7 X-SGSI-MailScanner: Found to be clean X-SGSI-From: christoph.paasch@uclouvain.be X-SGSI-Spam-Status: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On 22/04/14 - 05:27:55, Madhan wrote: > hi , > Is it possible to update the option field of the tcp header dynamically by the driver rather than the change in tcp/ip stack . > i.e Can i add a driver to implement mptcp rather than building entire kernel again ? in principle it seems possible to do this at a driver-level. Alcatel-Lucent implemented something similar using netfilter-hooks: https://open-innovation.alcatel-lucent.com/projects/mptcp-proxy Regular TCP was running on top, and the netfilter hooks allowed to rewrite the TCP/IP header. However, I think that doing it that way will be huge implementation effort (considering that there exists already an open-source implementation at multipath-tcp.org) and it might be hard to achieve good performance and make it scale properly. You basically have to reimplement a full TCP-stack at the driver as each TCP-subflow has to behave as regular TCP (3-way handshake, retransmissions,...) Cheers, Christoph -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/