From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id C99DB214A for ; Fri, 7 Oct 2016 22:53:03 +0200 (CEST) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 07 Oct 2016 13:53:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,456,1473145200"; d="scan'208";a="1061944249" Received: from irsmsx105.ger.corp.intel.com ([163.33.3.28]) by orsmga002.jf.intel.com with ESMTP; 07 Oct 2016 13:53:03 -0700 Received: from irsmsx108.ger.corp.intel.com ([169.254.11.164]) by irsmsx105.ger.corp.intel.com ([169.254.7.196]) with mapi id 14.03.0248.002; Fri, 7 Oct 2016 21:53:00 +0100 From: "De Lara Guarch, Pablo" To: Akhil Goyal , "Gonzalez Monroy, Sergio" , "dev@dpdk.org" Thread-Topic: [PATCH] examples/ipsec-secgw: Update checksum while decrementing ttl Thread-Index: AQHSHtJJ2RZYZPK2TU2VpeQvRbL0OaCdZMYw Date: Fri, 7 Oct 2016 20:53:00 +0000 Message-ID: References: <20160926163300.22990-1-akhil.goyal@nxp.com> <53327b5c-9a6f-9336-fbb7-109204a8ff0b@nxp.com> In-Reply-To: <53327b5c-9a6f-9336-fbb7-109204a8ff0b@nxp.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiNzIyYmM3Y2YtM2Y1My00NjEzLWJmMzktYjU3YzY3MTA0YTkzIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6IkJJRzZnQ1RHVHFxYlE0QlVOck1RZnVFbkprY0xkaG1VaFFuaWtsU1FvaEE9In0= x-ctpclassification: CTP_IC x-originating-ip: [163.33.239.182] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH] examples/ipsec-secgw: Update checksum while decrementing ttl X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 07 Oct 2016 20:53:04 -0000 > -----Original Message----- > From: Akhil Goyal [mailto:akhil.goyal@nxp.com] > Sent: Tuesday, October 04, 2016 11:33 PM > To: De Lara Guarch, Pablo; Gonzalez Monroy, Sergio; dev@dpdk.org > Subject: Re: [PATCH] examples/ipsec-secgw: Update checksum while > decrementing ttl >=20 > On 10/5/2016 6:04 AM, De Lara Guarch, Pablo wrote: > > > > > >> -----Original Message----- > >> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Sergio Gonzalez > >> Monroy > >> Sent: Monday, September 26, 2016 6:28 AM > >> To: akhil.goyal@nxp.com; dev@dpdk.org > >> Subject: Re: [dpdk-dev] [PATCH] examples/ipsec-secgw: Update checksum > >> while decrementing ttl > >> > >> Hi Akhil, > >> > >> This application relies on checksum offload in both outbound and > inbound > >> paths (PKT_TX_IP_CKSUM flag). > [Akhil]Agreed that the application relies on checksum offload, but here > we are talking about the inner ip header. Inner IP checksum will be > updated on the next end point after decryption. This would expect that > the next end point must have checksum offload capability. What if we are > capturing the encrypted packets on wireshark or say send it to some > other machine which does not run DPDK and do not know about checksum > offload, then wireshark/other machine will not be able to get the > correct the checksum and will show error. > >> > >> Because we assume that we always forward the packet in both paths, we > >> decrement the ttl in both inbound and outbound. > >> You seem to only increment (recalculate) the checksum of the inner IP > >> header in the outbound path but not the inbound path. > [Akhil]Correct I missed out the inbound path. > >> > >> Also, in the inbound path you have to consider a possible ECN value > update. > [Akhil]If I take care of the ECN then it would mean I need to calculate > the checksum completely, incremental checksum wont give correct results. > This would surely impact performance. Any suggestion on how should we > take care of ECN update. Should I recalculate the checksum and send the > patch for ECN update? Or do we have a better solution. > > > > Any further comments here, Akhil? > > > > Thanks, > > Pablo > > > [Akhil] Sorry I missed out the previous reply from Sergio. Any more comments, Sergio? Pablo >=20 > Thanks, > Akhil > >>