From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id 8B06DA0096 for ; Wed, 8 May 2019 15:58:53 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id EB4A52BD5; Wed, 8 May 2019 15:58:52 +0200 (CEST) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id D4B0D2862 for ; Wed, 8 May 2019 15:58:50 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 May 2019 06:58:49 -0700 X-ExtLoop1: 1 Received: from fmsmsx105.amr.corp.intel.com ([10.18.124.203]) by orsmga008.jf.intel.com with ESMTP; 08 May 2019 06:58:49 -0700 Received: from fmsmsx117.amr.corp.intel.com ([169.254.3.26]) by FMSMSX105.amr.corp.intel.com ([169.254.4.204]) with mapi id 14.03.0415.000; Wed, 8 May 2019 06:58:49 -0700 From: "Wiles, Keith" To: hirok borah CC: Anupama Laxmi , users Thread-Topic: [dpdk-users] UDP packet transmission issue - DPDK 18.08 Thread-Index: AQHU9y9clSoOGSL0j0qzYQapRzJp4aZhWTOAgAB6GAA= Date: Wed, 8 May 2019 13:58:48 +0000 Message-ID: <95C022B5-CB05-4C30-A57A-A9B183548107@intel.com> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.254.105.50] Content-Type: text/plain; charset="us-ascii" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-users] UDP packet transmission issue - DPDK 18.08 X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org Sender: "users" > On May 8, 2019, at 1:41 AM, hirok borah wrote: >=20 > Hi All, >=20 > Do we have any resolution for this issue yet ? > This looks like a defect in DPDK 18.08. DPDK does not understand UDP/TCP or any L4 Packet per say, it only sends th= e packets constructed in the application. It will send the packets as defin= ed and the only place DPDK tries to determine the packet type is when it re= ceives the packet which in this case is the kernel. I do not use testpmd much, but use pktgen-dpdk for my work. Please try with= testpmd or pktgen or TRex or moongen and see if the problem still exists. >=20 > Plz share if anyone have any inputs on this issue. >=20 > Regards > Hirok >=20 > On Sat, Apr 20, 2019 at 9:41 AM Anupama Laxmi > wrote: >=20 >> We have recently upgraded to DPDK 18.08 version. After upgrading to the >> latest version observing issue with UDP packets transmission errors for = few >> packets ( UDP size 736 bytes) .With older version of DPDK we never face= d >> this issue. >>=20 >> Attaching the filtered tcpdump which shows "Bad UDP length > IP payload >> length" for one such packet. >>=20 >> No issue observed while transferring UDP packets with size 28 bytes and = 48 >> bytes. I tried to print the packet length calculation in my program just >> before sending it out to the Kernel using rte_kni_tx_burst. The packet >> length calculation seems correct to me. >>=20 >> 1.) >> size_udp:48 >> sizeof(struct udp_hdr):8 >> size_ApplMsg:40 >> udphdr->dgram_len:12288 >> m->data_len:82 >> size_ip:68 >> l2_data_shift:14 >>=20 >> 2.) >> size_udp:28 >> sizeof(struct udp_hdr):8 >> size_ApplMsg:20 >> udphdr->dgram_len:7168 >> m->data_len:62 >> ip->total_length:12288 >> size_ip:48 >> l2_data_shift:14 >>=20 >> *** Packets with UDP size 736 are not getting transmitted to the >> receiving end and getting dropped. >>=20 >> 3.) >> size_udp:736 >> sizeof(struct udp_hdr):8 >> size_ApplMsg:728 >> udphdr->dgram_len:57346 >> m->data_len:770 >> size_ip:756 >> l2_data_shift:14 >>=20 >> Also MTU is set to 1500 in my program. So it shouldn't be an issue to >> transfer 736 bytes UDP data which is less than 1500 bytes MTU. >>=20 >> Looks like the kernel is dropping this packet. >>=20 >> So I tried to increase the kernel buffer size but that didn't help. >>=20 >> netstat -su -> output shows 0 send/receive buffer errors. >>=20 >>=20 >> What has changed in DPDK 18.08 with respect to UDP packets? Please sugge= st >> if I need to consider tuning udp ( using new API ) , offloading udp >> traffic(new offload flags) to resolve this issue. >>=20 >> Thanks, >> -------------- next part -------------- >> A non-text attachment was scrubbed... >> Name: bad_udp_length.png >> Type: image/png >> Size: 56015 bytes >> Desc: not available >> URL: < >> http://mails.dpdk.org/archives/users/attachments/20190420/f5dd6779/attac= hment.png >>>=20 >>=20 >=20 >=20 > --=20 > Regards, > -Hirok Regards, Keith