Re: [PATCH] ieee80211 subsystem

["Randy.Dunlap" <rddunlap@osdl.org>]

James Ketrenos wrote:
> Attached is the patch against 2.6.11-rc3-mm1 that adds the ieee80211 
> subsystem used by the ipw2100 and ipw2200 projects.
> 
> I'll be sending out the patches for ipw2100-1.0.0 and ipw2200-1.0.0 that 
> use thist stack to the list on Monday.
> 
> In terms of what the stack currently does:
> 
> * HW independent -- it only knows about 802.11 data and structures
> * Performs an 802.3 <-> 802.11 transform for data Tx/Rx
> * Host based support for fragmentation, WEP, and WPA using the kernel's 
> crypto functions
> * Beacon and probe response collection and parsing
> * Default implementation of some of the WE handlers that can be managed 
> without hardware knowledge
> 
> We are working to merge in Dave Miller's p80211 code into the ieee80211 
> subsystem so that it hooks into the kernel as a true network layer as 
> opposed to a mutated offspring of ethernet.
> Once that is done, hopefully the skb to txb code can be reworked and 
> 802.11 fragments can be treated either as normal skbs, or skbs can be 
> modified to directly support them (ideally so that encrypted 802.11 
> frames in support of IP packets can be cached by the stack instead of 
> having to be re-encrypted on TCP retries)
> 
> Support for HW/FW crypto and fragmentation offload, in a HW independent 
> fashion, is also on the short-term list.
> 
> When you look through the patch you'll likely notice the #ifdef 
> NOTYET/#endif sequences surrounding portions of code from the hostap 
> project.  Portions of this subsystem were based on an earlier version of 
> the hostap project.  Those areas that weren't directly supported by the 
> ipw* projects weren't ported to be completely hardware independent 
> (since I don't have the hardware to test it), and so are still wrapped 
> in the ifdefs.  These sections mainly cover support for MASTER and WDS 
> modes.
> 
> Anyway, please let me know what you think.  Hopefully I built the patch 
> right...

Here are a few more comments.

1.  No need to check ptr for NULL before kfree(ptr), so several
places like this can be simplified:

+fail:
+	if (priv) {
+		if (priv->tfm)
+			crypto_free_tfm(priv->tfm);
+		kfree(priv);
+	}

2.  drivers/net/wireless/ieee80211/ieee80211_rx.c
includes:  +#include "ieee80211.h"
Should that be ../ieee80211.h (which I dislike), or
should the Makefile specify -I to the parent directory, or what?
IOW, I don't see how it finds the header file, but the
"able to build request" will fix this one.

3.  +static inline int ieee80211_network_init()
is more than 200 lines.  Somebody likes huge inline functions.

(wow, 1/2 thru a 4900 line patch :)
-- 
~Randy