DPDK patches and discussions
 help / color / mirror / Atom feed
From: Olivier MATZ <olivier.matz@6wind.com>
To: Prashant Upadhyaya <praupadhyaya@gmail.com>, dev@dpdk.org
Subject: Re: [dpdk-dev] Regarding UDP checksum offload
Date: Wed, 28 Jan 2015 14:02:43 +0100	[thread overview]
Message-ID: <54C8DDF3.2000802@6wind.com> (raw)
In-Reply-To: <CAPBAu3V594AoWqzWoFBhwyqq9uodkcrof88eHoE3QpF75uXuwA@mail.gmail.com>

Hi Prashant,

On 01/28/2015 12:25 PM, Prashant Upadhyaya wrote:
> 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.


As far as I remember, this should be working on 1.6r1.
When you say "did not reach the destination", do you mean that the
packet is not transmitted at all? Or is it transmitted with a wrong
checksum?

I think you should try to reproduce the issue with the latest DPDK
which is known to work with test-pmd (csum forward engine).

Regards,
Olivier

  reply	other threads:[~2015-01-28 13:03 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-28 11:25 Prashant Upadhyaya
2015-01-28 13:02 ` Olivier MATZ [this message]
2015-01-28 14:57   ` Prashant Upadhyaya
2015-01-28 15:09     ` Olivier MATZ
2015-01-29 12:56       ` Prashant Upadhyaya
2015-01-30  9:15         ` Olivier MATZ

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=54C8DDF3.2000802@6wind.com \
    --to=olivier.matz@6wind.com \
    --cc=dev@dpdk.org \
    --cc=praupadhyaya@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).