Re: [PATCH,RFC] skb->network_header and __vlan_put_tag()

[Patrick McHardy <kaber@trash.net>]

[Don't trim CC lists please]

Benny Amorsen wrote:
> Lennert Buytenhek <buytenh@wantstofly.org> writes:
> 
>> I'm adding VLAN support to mv643xx_eth (which does not support HW
>> insertion of a VLAN tag, but it does support HW checksumming when
>> a VLAN tag is present, you just have to tell the HW how many bytes
>> there are between the start of the packet and the IP header), and
>> I'm ending up with code like this:
>>
>> 	if (skb->protocol == htons(ETH_P_8021Q))
>> 		ip_header = ip_hdr(skb) + 4;
>> 	else
>> 		ip_header = ip_hdr(skb);
> 
> How well does this work when doing QinQ or QinQinQ?

Currently probably doesn't work, so the patch makes even more
sense.