From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <praupadhyaya@gmail.com>
Received: from mail-we0-f169.google.com (mail-we0-f169.google.com
 [74.125.82.169]) by dpdk.org (Postfix) with ESMTP id 64114255
 for <dev@dpdk.org>; Wed, 28 Jan 2015 12:25:00 +0100 (CET)
Received: by mail-we0-f169.google.com with SMTP id u56so20205566wes.0
 for <dev@dpdk.org>; Wed, 28 Jan 2015 03:25:00 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113;
 h=mime-version:date:message-id:subject:from:to:content-type;
 bh=kH5DfshZmPyUrTaFJeM4Z/qsy37C9Hxvday49HNiZtw=;
 b=CTuJmkjzMlXs33InPdWEDvClaG5SAr4wO/8GfNcQ+clPeCwRh6EeZXrBUXWnmiMZnM
 zmxzN+1YSvcqyLyXl5QVdELTVm6ASBl8JUOdWLTrYavgbFTGDk8XTLwNlAvbDjVaNy+e
 LQmkvLtaOTiKMj9ck4g9E56gsdMPWRDlqb9FRvaBgvfq+No6FZJE9LDPWpFNyJ8vP1/2
 WvbjivEvGPdl0cGQmac5F8fxuA+i59F6eA+fx9/6JtVLyGtq6rCJpNHlK7+h6OryTgMc
 iyXfIm4yw5nOteDBy1FfnD1KmJEEZJCYhUiVaEHvQlLgN2LrwOwDPSvZ8Ins/DqQNsif
 7rsg==
MIME-Version: 1.0
X-Received: by 10.194.187.235 with SMTP id fv11mr6560732wjc.16.1422444300223; 
 Wed, 28 Jan 2015 03:25:00 -0800 (PST)
Received: by 10.194.2.10 with HTTP; Wed, 28 Jan 2015 03:25:00 -0800 (PST)
Date: Wed, 28 Jan 2015 16:55:00 +0530
Message-ID: <CAPBAu3V594AoWqzWoFBhwyqq9uodkcrof88eHoE3QpF75uXuwA@mail.gmail.com>
From: Prashant Upadhyaya <praupadhyaya@gmail.com>
To: dev@dpdk.org
Content-Type: text/plain; charset=UTF-8
X-Content-Filtered-By: Mailman/MimeDel 2.1.15
Subject: [dpdk-dev] Regarding UDP checksum offload
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: patches and discussions about DPDK <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Wed, 28 Jan 2015 11:25:00 -0000

Hi,

I am aware that this topic has been discussed several times before, but I
am somehow still stuck with this.

I am using dpdk 1.6r1, intel 82599 NIC.
I have an mbuf, I have hand-constructed a UDP packet (IPv4) in the data
portion, filled the relevant fields of the headers and I do a tx burst. No
problems, the destination gets the packet. I filled UDP checksum as zero
and there was no checksum offloaded in ol_flags.

Now in the same usecase, I want to offload UDP checksum.
I am aware that the checksum field in UDP header has to be filled with the
pseudo header checksum, I did that, duly added the PKT_TX_UDP_CKSUM flag in
ol_flags, did a tx_burst and the packet does not reach the destination.

I realized that I have to fill the following fields as well (my packet does
not have vlan tag)
mbuf->pkt.vlan_macip.f.l2_len
mbuf->pkt.vlan_macip.f.l3_len

so I filled the l2_len as 14 and l3_len as 20 (IP header with no options)
Yet the packet did not reach the destination.

So my question is -- am I filling the l2_len and l3_len properly ?
Is there anything else to be done before I can get this UDP checksum
offload to work properly for me.

Regards
-Prashant