From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 725072CA6 for ; Wed, 11 May 2022 15:22:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1652282567; x=1683818567; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=L+nuBF7MplyUdywP4Gq83RRfCgGSbCvlCCOVzMyGdu0=; b=WiIx5nxWFJj4Rqvum8rJV3Xvg1/Mz8k/93SUQx5UiAnWDHqs89mqphER +17Ctt28TUsc8qvg55BtU1X5mJo+/01y9+Cfo0Sd+dV+OuhoeVFm+7Ck5 SgEYs7bbiJRS0Eaktj4ViKumAvd8m+O5nnYlWnUbpoSySFzi4sbv2CM2p Bx0BA6JUvWfWLCdCyF/Q1T82aoMElCR8VyNkC0j/A0qOIURwDNPO2V2H7 RbA/wRN4w194zc3GnAr9SQpmwQGtw04MG2OwkHvSsAts1u5RrXFlPuY/v USbbRmKORxyauGSZ84LdBDPFWhMKFlBWWrucemKoG2aQkmpgjr5RfraXJ A==; X-IronPort-AV: E=McAfee;i="6400,9594,10344"; a="268565614" X-IronPort-AV: E=Sophos;i="5.91,217,1647327600"; d="scan'208";a="268565614" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2022 08:22:45 -0700 X-IronPort-AV: E=Sophos;i="5.91,217,1647327600"; d="scan'208";a="572130201" Received: from rdstein-mobl.amr.corp.intel.com ([10.212.177.197]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2022 08:22:45 -0700 Date: Wed, 11 May 2022 08:22:36 -0700 (PDT) From: Mat Martineau To: Paolo Abeni cc: mptcp@lists.linux.dev Subject: Re: [PATCH mptcp-next v2] mptcp: fix checksum byte order In-Reply-To: <2bf857cc4abe21426ce2418645667663ca7cefcb.camel@redhat.com> Message-ID: References: <595f104803a212df58db6d20f84947325b33a9d6.1652196378.git.pabeni@redhat.com> <331ef61b-19b7-ea0-6832-ebf3c97aa9c@linux.intel.com> <2bf857cc4abe21426ce2418645667663ca7cefcb.camel@redhat.com> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed On Wed, 11 May 2022, Paolo Abeni wrote: > On Tue, 2022-05-10 at 16:10 -0700, Mat Martineau wrote: >> On Tue, 10 May 2022, Paolo Abeni wrote: >> >>> The MPTCP code typecasts the checksum value to u16 and >>> then convert it to big endian while storing the value into >>> the MPTCP option. >>> >>> As a result, the wire encoding for little endian host is >>> wrong, and that causes interoperabilty interoperability >>> issues with other implementation or host with different endianess. >>> >>> Address the issue writing in the packet the unmodified __sum16 value. >>> >>> MPTCP checksum is disabled by default, interoperating with systems >>> with bad mptcp-level csum encodying should cause fallback to TCP. >>> >>> Fixes: c5b39e26d003 ("mptcp: send out checksum for DSS") >>> Fixes: 390b95a5fb84 ("mptcp: receive checksum for DSS") >>> Signed-off-by: Paolo Abeni >>> --- >>> v1 -> v2: >>> - move the typecast inside put_len_csum (Mat) >>> - updated the commit message (Mat) >>> - fix a few sparse issues >> >> Hi Paolo, thanks for the v2: >> >> Reviewed-by: Mat Martineau >> >> (for export-net) >> >> Still ok with you to apply this to export-net? There are a couple of minor >> conflicts when rebasing to export-net, and it also creates a merge >> conflict with net-next. But I think it's worth it to be able to say "every >> 5.18 and later kernel has the checksum fix". > > Agreed. > >> Have you tried backporting this commit to 5.17-stable or 5.15-stable? > > No, that is likely worthy, but I really have my hands full :( I think I > can have a look not earlier than next week. No problem - I can handle the backporting and sending to the stable trees. -- Mat Martineau Intel