Re: [PATCH net 0/4] Fix checksum error when using stacked vlan

[David Miller <davem@davemloft.net>]

From: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Date: Thu, 29 Jan 2015 20:37:06 +0900

> When I was testing 802.1ad, I found several drivers don't take into
> account 802.1ad or multiple vlans when retrieving L3 (IP/IPv6) or
> L4 (TCP/UDP) protocol for checksum offload.
> 
> It is mainly due to vlan_get_protocol(), which extracts ether type only
> when it is tagged with single 802.1Q. When 802.1ad is used or there are
> multiple vlans, it extracts vlan protocol and drivers cannot determine
> which L3/L4 protocol is used.
> 
> Those drivers, most of which have IP_CSUM/IPV6_CSUM features, get L3/L4
> header-offset by software, so it seems that their checksum offload works
> with multiple vlans if we can parse protocols correctly.
> (They know mac header length, and probably don't care about what is in it.)
> 
> And another thing, some of Intel's drivers seem to use skb->protocol where
> vlan_get_protocol() is more suitable.
> 
> I tested that at least igb/igbvf on I350 works with this patch set.
> 
> Note:
> We can hand a double tagged packet with CHECKSUM_PARTIAL to a HW driver
> by creating a vlan device on a bridge device and enabling vlan_filtering
> of the bridge with 802.1ad protocol.

Series applied, thank you.