From: Andrew Rybchenko <arybchenko@solarflare.com>
To: "N. Benes" <nbenes@eso.org>, dev <dev@dpdk.org>
Cc: Olivier Matz <olivier.matz@6wind.com>,
Stephen Hemminger <stephen@networkplumber.org>,
Thomas Monjalon <thomas@monjalon.net>
Subject: Re: [dpdk-dev] Bug in IPv4 header checksum computation?
Date: Tue, 2 Apr 2019 10:58:52 +0300 [thread overview]
Message-ID: <105860ec-b4b7-b045-05e0-6fb67bab237a@solarflare.com> (raw)
In-Reply-To: <65744706-bc88-f144-f85e-1b0292402cff@eso.org>
Hi,
added more people in CC.
On 4/1/19 6:29 PM, N. Benes wrote:
> Hi,
>
> I wrote to the users list a bit more a week ago concerning the IPv4
> Header Checksum computation and received no comments on it yet:
>
> https://mails.dpdk.org/archives/users/2019-March/004021.html
> https://mails.dpdk.org/archives/users/2019-March/004022.html
>
> I have the impression that the current implementation wrongly does a
> conditional final inversion of the computed sum. This is correct for
> e.g. UDP, but I think it is not for an IPv4 Header (header checksum is
> not optional).
>
> If it is a bug, this could result in a surprisingly high number of
> invalid/dropped IPv4 packets, when the checksum is calculated manually
> via the DPDK API (not NIC-offloaded) and the IPv4 header has an
> appropriate combination of values e.g. the IP Identification field.
I agree that it looks like a bug in DPDK. RFC 791 says nothing about
avoid zero value for IPv4 checksum.
Andrew.
next prev parent reply other threads:[~2019-04-02 7:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-01 15:29 N. Benes
2019-04-01 15:29 ` N. Benes
2019-04-02 7:58 ` Andrew Rybchenko [this message]
2019-04-02 7:58 ` Andrew Rybchenko
2019-04-02 8:46 ` Olivier Matz
2019-04-02 8:46 ` Olivier Matz
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