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

From: Simon Horman
Date: Wed Aug 18 2010 - 01:57:30 EST


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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