From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexei Starovoitov <ast@plumgrid.com>
Subject: Re: [PATCH] filter: introduce SKF_AD_VLAN_PROTO BPF extension
Date: Wed, 04 Mar 2015 15:47:06 -0800
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Cc: Michal Sekletar <msekleta@redhat.com>, netdev@vger.kernel.org,
	Jiri Pirko <jpirko@redhat.com>
To: Guy Harris <guy@alum.mit.edu>
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On 3/4/15 1:14 PM, Guy Harris wrote:
>
> On Mar 4, 2015, at 1:03 PM, Alexei Starovoitov <ast@plumgrid.com> wrote:
>
>> the patch is correct and looks clean, but I don't understand
>> the motivation for the patch.
>> There is already SKF_AD_VLAN_TAG_PRESENT. If it is set then only
>> two possible values of vlan_proto are ETH_P_8021Q or ETH_P_8021AD.
>> If there another vlan header inside the packet, it's AD.
>> So you can do the filtering already without adding new bpf extension...
>
> I presume he's referring to
>
> 	https://github.com/the-tcpdump-group/libpcap/issues/397
>
> or
>
> 	https://github.com/the-tcpdump-group/libpcap/issues/390

ok. context is clear.
yet, it still sounds like something to fix inside libpcap.