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Message-ID: <6d6a94c50704120331m36957148iae111ab7324c88c2@mail.gmail.com>
Date: Thu, 12 Apr 2007 18:31:30 +0800
From: "Aubrey Li" <aubreylee@gmail.com>
To: "Stephen Hemminger" <shemminger@osdl.org>,
       "Herbert Xu" <herbert@gondor.apana.org.au>,
       "Matt Mackall" <mpm@selenic.com>
Subject: udp checksum issue in netpoll mode.
Cc: netdev@vger.kernel.org, "Linux Kernel" <linux-kernel@vger.kernel.org>
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Sender: linux-kernel-owner@vger.kernel.org
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I think we discussed this issue before.

The current checksum function doesn't consider the kind of packet
which is padded to reach a specific minimum length. I believe that's
the problem caused my test case failed. Is this issue fixed? Or is it
acceptable if I make a patch not calculating this kind of packet?

Thanks,
-Aubrey
===============================================
static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
                            unsigned short ulen, __be32 saddr, __be32 daddr)
{
        __wsum psum;

        if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY)
                return 0;

        psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
        if (skb->ip_summed == CHECKSUM_COMPLETE &&
            !csum_fold(csum_add(psum, skb->csum)))
                return 0;

        skb->csum = psum;

        return __skb_checksum_complete(skb);
}
===============================================