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From: David Malone <dwmalone@maths.tcd.ie>
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Subject: Re: cvs commit: src/sys/net bpf.c 
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> > libpcap does not need to be modified; it works already for
> > wireless. The fact that the DLT is named DLT_IEEE802_11_RADIO is a
> > bit of a misnomer; it's not entirely 802.11-specific.

> Ah, you mean we just exploit DLT_IEEE802_11_RADIO.  Hmm...  How about 
> processing overhead?  Can we synchronize the timestamping with system 
> time?

It sounds to me like a reasonable thing to do would be to pass up
a raw version of the timestamp (as returned by the hardware). We'd
also pass up the regular microtime() timestamp. You can then do any
postprocessing to syncronise timestamps later in userland?

> Okay.  But I am worried about timecounter <-> timeval conversion 
> because I want to know timeval delta from system time, not just some 
> timer value.

If we do it in the kernel, then we probably need to look into
expanding the timecounter infrastructure quite a lot, particularly
if you want to be able to apply NTP adjustments to multiple counters
at the same time.

	David.