From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE5A1C3F2CE for ; Thu, 5 Mar 2020 01:07:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF3642084E for ; Thu, 5 Mar 2020 01:07:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725839AbgCEBHV (ORCPT ); Wed, 4 Mar 2020 20:07:21 -0500 Received: from mga12.intel.com ([192.55.52.136]:28998 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725774AbgCEBHV (ORCPT ); Wed, 4 Mar 2020 20:07:21 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Mar 2020 17:07:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,516,1574150400"; d="scan'208";a="439322975" Received: from mlee22-mobl.amr.corp.intel.com ([10.251.30.98]) by fmsmga005.fm.intel.com with ESMTP; 04 Mar 2020 17:07:20 -0800 Date: Wed, 4 Mar 2020 17:07:20 -0800 (PST) From: Mat Martineau X-X-Sender: mjmartin@mlee22-mobl.amr.corp.intel.com To: Paolo Abeni cc: netdev@vger.kernel.org, Matthieu Baerts , "David S. Miller" , Christoph Paasch Subject: Re: [PATCH net v2] mptcp: always include dack if possible. In-Reply-To: Message-ID: References: User-Agent: Alpine 2.22 (OSX 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 4 Mar 2020, Paolo Abeni wrote: > Currently passive MPTCP socket can skip including the DACK > option - if the peer sends data before accept() completes. > > The above happens because the msk 'can_ack' flag is set > only after the accept() call. > > Such missing DACK option may cause - as per RFC spec - > unwanted fallback to TCP. > > This change addresses the issue using the key material > available in the current subflow, if any, to create a suitable > dack option when msk ack seq is not yet available. > > v1 -> v2: > - adavance the generated ack after the initial MPC packet > > Fixes: d22f4988ffec ("mptcp: process MP_CAPABLE data option") > Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau -- Mat Martineau Intel