Re: IPv6-UDP 0x0000 checksum

[Eric Dumazet <eric.dumazet@xxxxxxxxx>]

On Thu, 2017-01-26 at 07:24 -0800, Eric Dumazet wrote:
> On Thu, 2017-01-26 at 15:49 +0100, Johannes Berg wrote:
> 
> > Unfortunately, I haven't been able to actually test this yet. I also
> > didn't find the code that would drop frames with CSUM 0 either, so I'm
> > thinking - for now - that if all the csum handling is skipped, dropping
> > 0 csum frames would also be, and then we'd accept a frame we should
> > actually have dropped.
> > 
> > I'll go test this I guess :)
> > 
> > Any pointers to where 0 csum frames are dropped?
> 
> Probably in udp6_csum_init()

vi +804 net/ipv6/udp.c

                if (!uh->check && !udp_sk(sk)->no_check6_rx) {
                        udp6_csum_zero_error(skb);
                        goto csum_error;
                }