From: "\"Thomas B. Rücker\"" <dm8tbr@openpma.org>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: shemminger@linux-foundation.org, pg@futureware.at,
netdev@vger.kernel.org
Subject: Re: UDP checksum broken since 2.6.18?
Date: Wed, 23 May 2007 10:33:16 +0000 [thread overview]
Message-ID: <4654186C.8050505@openpma.org> (raw)
In-Reply-To: <E1Hqnea-0006Af-00@gondolin.me.apana.org.au>
Herbert Xu wrote:
> "Thomas B. R??cker" <dm8tbr@openpma.org> wrote:
>
>> Stephen Hemminger wrote:
>>
>>> The packet passed to packet capture programs may not have a valid checksum
>>> if you have checksum offload configured on the device. What kind of hardware
>>> do you have on sender and receiver?
>>>
>> The c-snippet uses 127.x.x.x --> loopback
>>
>
> We never compute the complete checksum for loopback so that explains
> the bogus checksum.
>
Does this also explain why wireshark thinks the checksum is right when
tested on <=2.6.17?
Cheers
Thomas
next prev parent reply other threads:[~2007-05-23 10:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-22 21:47 UDP checksum broken since 2.6.18? "Thomas B. Rücker"
2007-05-22 23:12 ` Stephen Hemminger
2007-05-22 23:33 ` "Thomas B. Rücker"
2007-05-23 10:01 ` Herbert Xu
2007-05-23 10:33 ` "Thomas B. Rücker" [this message]
2007-05-23 11:50 ` Herbert Xu
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