Subject: Re: generic 802.11 stack

From: Vladimir Kondratiev <[email-masked]>
Date: Tue, 7 Sep 2004 21:06:24 +0300

DS> > - there are cases when PHY information needed, to make decisions (like
 select DS> > AP from list), or for information purposes (sniffer). What is
 your vision how DS> > to do this? I.e. provide some standard PHY header
 before MAC header, out of DS> > band (use cb?)
DS>
DS> This should be stored in the 802.11 specific information struct which
DS> I allocate for each generic device which registers with the 802.11
DS> layer.  There should be a standard 802.11 stack interface the driver
DS> can use the pass the information in so that the details of the layout
DS> inside of the 802.11 device information structure need not be exported
DS> publicly.
DS>
DS> > - there is PHY level information that may be needed for Tx:
DS> > modulation;rate;retry policy and rates;Tx power;protection(RTS/CTS, CTS
 to DS> > self). Same question as above: how to provide it?
DS>
DS> Same way.

May be I did not stated the question clearly. This information need to be 
specified per packet. So question ramains: how to specify PHY info per skb.

DS>
DS> > - there is some interesting information that may come from Tx status,
 like DS> > success indication, last rate, retry count, energy in channel
 after packet, DS> > actual backoff time.
DS>
DS> Feed it back into the software stack with some kind of function call.
DS>
I tend to agree, with one note that it should be some mechanism to associate 
this information with original packet. One implementation example would be to 
keep original skb in some "in process" queue, and actually free it after Tx 
status arrival.