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From: David Miller <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
Subject: Re: [RFC 1/3] bpf/wireless: add wifimon program type
Date: Wed, 12 Apr 2017 11:19:13 -0400 (EDT)
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From: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
Date: Wed, 12 Apr 2017 16:27:34 +0200

> This works. An example BPF program is here:
> https://p.sipsolutions.net/ca32264f2b705e5e.txt
 ...
> One thing I'm not so sure about is the usage of __sk_buff.
 ...
> Instead it may make more sense to just have a "wifi_info(skb, info)"
> function you can call, e.g. with a structure that has various fields
> and flags to see which you care about.

I would advise against this, let the parsing part use __sk_buff and
therefore have maximum flexibility.  You really cannot predict the
future, so in my opinion it might be unwise to constrain at this point.