PERFORCE change 136138 for review

[Sam Leffler]

Sam Leffler wrote:
> http://perforce.freebsd.org/chv.cgi?CH=136138
>
> Change 136138 by sam at sam_ebb on 2008/02/25 02:54:10
>
> 	o require drivers to allocate the ifnet w/ IFT_IEEE80211
> 	  instead of blindly clobbering if_type in ieee80211_ifattach;
> 	  this is effectively a noop but codifies the fact drivers
> 	  are 802.11-specific
> 	o fix various radiotap bogosity in drivers; in particular
> 	  we no longer need to use bpfattach2 or maintain a private
> 	  sc_drvbpf as if_bpf isn't used by way of attaching as an
> 	  802.11 device (and not calling ether_ifattach)
>
>   
FWIW switching over to use if_bpf is required to make tcpdump work on 
the parent device as otherwise BIOCSETIF fails because it checks for 
if_bpf being NULL and that doesn't happen any more as a side effect of 
calling ether_ifattach.  netbsd is smarter about this; it walks the 
bpf_iflist regardless of if_bpf.

    Sam