From: Daniel Borkmann <dborkman@redhat.com>
To: Tom Herbert <therbert@google.com>
Cc: Linux Netdev List <netdev@vger.kernel.org>,
Thomas Graf <tgraf@redhat.com>
Subject: Re: Does CHECKSUM_COMPLETE work at all?
Date: Sat, 22 Feb 2014 13:31:04 +0100 [thread overview]
Message-ID: <53089888.5020307@redhat.com> (raw)
In-Reply-To: <CA+mtBx8safaPpcntjqT+eUQBDEOxJBoVf-a9djX_qgYsSdACeA@mail.gmail.com>
On 02/22/2014 03:11 AM, Tom Herbert wrote:
> If a driver sets CHECKSUM_COMPLETE in a packet, I don't see anywhere
> in either the Ethernet rcv path or ip_rcv where the skb->csum is being
> pulled (no *pull_rcsum calls). I believe CHECKSUM_COMPLETE means the
> checksum is over the whole packet (L2, L3, and L4), so it looks like
> TCP would never see a usable value.
Funny you ask, we had recently similar question [1]. ;) So, yes, it
should be over the whole packet as seen by Linux, and is therefore not
usable as is by protocols like TCP.
[1] http://thread.gmane.org/gmane.linux.network/292443/
prev parent reply other threads:[~2014-02-22 12:31 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-22 2:11 Does CHECKSUM_COMPLETE work at all? Tom Herbert
2014-02-22 2:36 ` Dimitrios Michailidis
2014-02-22 3:08 ` Tom Herbert
2014-02-22 12:42 ` Daniel Borkmann
2014-02-22 17:32 ` Tom Herbert
2014-02-22 12:31 ` Daniel Borkmann [this message]
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