Re: [patch nf-next] IPVS: ICMPv6 checksum calculation

[xiaoyu Du]

I just replied to thank for his idea then, as he gived me some ideas
on how to manipulate
checksum. I tested the code today, but it doesn't seem to work. (I just wrote a
netfilter module and hooked the code on local_out , then ping6 the
address on another PC,
It failed.). I'll find out why.

2010/8/18 Simon Horman <horms@xxxxxxxxxxxx>:
> On Wed, Aug 18, 2010 at 12:20:14PM +0800, xiaoyu Du wrote:
>> 2010/8/18 David Miller <davem@xxxxxxxxxxxxx>:
>> > From: Simon Horman <horms@xxxxxxxxxxxx>
>> > Date: Wed, 18 Aug 2010 09:21:49 +0900
>> >
>> >> [ CCing netdev for comment ]
>> >>
>> >> On Tue, Aug 17, 2010 at 12:25:56PM +0300, Julian Anastasov wrote:
>> > Â...
>> >>> Â Â ÂMay be ip_vs_checksum_complete() is not needed here?
>> >>> Also, skb->csum is not valid for every ip_summed value.
>> >>> May be we need to apply CHECKSUM_PARTIAL kind of setup for the IPv6.
>> >>> Such example is net/ipv6/udp.c:udp6_ufo_send_check().
>> >>> Later dev_queue_xmit() and skb_checksum_help() should take care
>> >>> for the next steps. Something like this can be tested:
>> >>>
>> >>> Â Â Âicmph->icmp6_cksum = csum_ipv6_magic(&iph->saddr,
>> >>> Â Â Â Â Â Â Â&iph->daddr,
>> >>> Â Â Â Â Â Â Âskb->len - icmp_offset, IPPROTO_ICMPV6,
>> >>> Â Â Â Â Â Â Â0);
>> >>> Â Â Âskb->csum_start = skb_network_header(skb) - skb->head +
>> >>> Â Â Â Â Â Â Â Â Â Â Â Âicmp_offset;
>> >>> Â Â Âskb->csum_offset = offsetof(struct icmp6hdr, icmp6_cksum);
>> >>> Â Â Âskb->ip_summed = CHECKSUM_PARTIAL;
>> >>>
>> >
>> > Yes, using CHECKSUM_PARTIAL unconditionally would work.
>> >
>> Thanks, I learned this. You gave me a big cake.
>
> [ please don't top-post ]
>
> Xiaoyu, are you in a position to test the code proposed by Julian?
>
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