From: David Miller <davem@davemloft.net>
To: herbert@gondor.apana.org.au
Cc: xiaosuo@gmail.com, hadi@cyberus.ca, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, kaber@trash.net
Subject: Re: [PATCH] act_nat: the checksum of ICMP doesn't have pseudo header
Date: Sat, 31 Jul 2010 22:05:18 -0700 (PDT) [thread overview]
Message-ID: <20100731.220518.212680999.davem@davemloft.net> (raw)
In-Reply-To: <20100730143016.GA10543@gondor.apana.org.au>
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Fri, 30 Jul 2010 22:30:16 +0800
> On Fri, Jul 30, 2010 at 10:16:05PM +0800, Changli Gao wrote:
>>
>> I know we need to update the ICMP checksum if we alter the payload(the
>> inner IP header here) of ICMP. But I doubt if the update is really
>> necessary if the checksum is partial, as the checksum will be done
>> later(by ether skb_checksum_help() or NIC hardware). In fact, as there
>> isn't any pseudo header, the icmph->checksum should be always ZERO,
>> otherwise skb_checksum_help() or NIC will give the wrong checksums,
>> when the checksum is partial.
>
> Actually you are right. I suppose the only reason this has never
> shown up is because CHEKSUM_PARTIAL doesn't usually occur with
> forwarded packets.
>
> Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Also applied, thanks.
prev parent reply other threads:[~2010-08-01 5:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-30 0:04 [PATCH] act_nat: the checksum of ICMP doesn't have pseudo header Changli Gao
2010-07-30 9:09 ` Herbert Xu
2010-07-30 10:10 ` Changli Gao
2010-07-30 10:24 ` Herbert Xu
2010-07-30 14:16 ` Changli Gao
2010-07-30 14:30 ` Herbert Xu
2010-08-01 5:05 ` David Miller [this message]
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