Re: BPF code generation for radiotap

[Guy Harris <guy-FrUbXkNCsVf2fBVCVOL8/A@public.gmane.org>]

David Young wrote:

> Right now, all radiotap fields can be found without a loop.

I.e., can be found with a completely unrolled loop.

I might have to work on the optimizer to handle code such as

	if (field XXX is present)
		add AAA to the offset into the packet;
	if (field YYY is present)
		add BBB to the offset into the packet;

etc. - I remember seeing problems such as that when trying to handle 
either the token ring header (which is variable-length, with source 
routing stuff) or the 802.11 header in full generality (some frames have 
4 MAC addresses - those are frames being sent from one access point to 
another access point, right?).