netdev - Re: [PATCH net-next 2/2] openvswitch: Fix skb->protocol for vlan frames.

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Date:   Mon, 28 Nov 2016 14:58:33 -0800
From:   Jarno Rajahalme <jarno@....org>
To:     Jiri Benc <jbenc@...hat.com>
Cc:     netdev@...r.kernel.org
Subject: Re: [PATCH net-next 2/2] openvswitch: Fix skb->protocol for vlan frames.

> On Nov 28, 2016, at 2:42 PM, Jiri Benc <jbenc@...hat.com> wrote:
> 
> On Mon, 28 Nov 2016 14:29:39 -0800, Jarno Rajahalme wrote:
>> I’m not sure what you suggest here. Obviously the kernel ABI can not
>> be changed as existing userspace code expects upcalled packets to be
>> non-accelerated. Also, if userspace pushes vlan headers, the packet
>> will actually have them.
> 
> The user space API needs to be preserved, of course. I'm talking about
> what happens internally in the kernel.
> 
> See this patchset: https://www.spinics.net/lists/netdev/msg398827.html
> 

I did not try to apply this series yet, but given the recent L3 changes maybe it needs a rebase?

>> Would this incremental fix this:
>> 
>> diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
>> index 9be9fda..37f1bb9 100644
>> --- a/net/openvswitch/flow.c
>> +++ b/net/openvswitch/flow.c
>> @@ -354,6 +354,8 @@ static int parse_vlan(struct sk_buff *skb, struct
>> sw_flow_key *key) res = parse_vlan_tag(skb, &key->eth.vlan);
>> 		if (res <= 0)
>> 			return res;
>> +		if (skb->protocol == htons(ETH_P_TEB))
>> +			skb->protocol = key->eth.vlan.tpid;
>> 	}
>> 
>> 	/* Parse inner vlan tag. */
> 
> I'll look at this tomorrow. But it seems we're adding more and more
> hacks instead of cleaning up the vlan handling.
> 

Right, I just noticed that the incremental only handles the VLAN case.

I’ll post a v2 later today with a proper fix that solves the immediate issue. IMO this should be fixed independently of the VLAN handling series for which I have no informed opinion yet.

  Jarno

> Jiri