Re: [PATCH v2] mac80211: Get IV len from key conf and not cipher scheme

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2015-03-10 at 16:46 +0000, Cedric Izoard wrote:
> > How can this be correct? You have a cipher scheme, so you want to
> > encrypt, but now you're not doing that? Perhaps you should drop the
> > frame instead?
> >
> On Tx, cipher scheme is "only" available trough sta pointer and is only 
> used in ieee80211_crypto_cs_encrypt to get security header len.
> Since sta pointer is NULL for bcast messages, the proposed patch get the 
> security header length using the key->conf.iv_len instead.
> 
> If the key is installed with a cs, then key->conf.iv_len is initialized 
> with cs->hdr_len.
> 
> If the key is installed without a cs, then  key->conf.iv_len is 0 (hence 
> the early exit in ieee80211_crypto_cs_encrypt)

So in reality, you're checking "is this a CS key"? Perhaps there's a
better way to do that?

johannes