Re: mac80211 / iwl3945 + dynamic wep (again)

[Dan Williams <dcbw@redhat.com>]

On Sun, 2007-11-25 at 12:00 +0100, drago01 wrote:
> Johannes Berg wrote:
> > Hi,
> >
> >   
> >> First  sorry for the late report, the patches from the old thread fixed 
> >> the privacy mismatch issue and now I can connect to a dynamic wep 
> >> network. But the connection is not very stable because I get tons of wep 
> >> decrypt errors in dmesg (while the connection is working but slow).
> >> The same network works fine with ipw3945. Also iwl3945 works fine with 
> >> static wep. I tryed the hwcrypt engine (hwcrypt=1) but it did not change 
> >> anything.
> >> While connectiong with wpa_supplicant I saw that mac80211 does not 
> >> support the IW_AUTH_DROP_UNENCRYPTED ioctl while ipw3945 (ieee80211 
> >> based) does.
> >> Could this be related? ie. mac80211 tryes to decrypt unencrypted frames 
> >> instead of dropping them?
> >>     
> >
> > Odd. I'll have to take a look. I recently noticed that mac80211 would
> > always *accept* unencrypted frames but it shouldn't try to decrypt them.
> >
> >   
> ok thx, let me now if you need more info / tests.
> >> Second problem is that ssid is hidden. I was able to connect to it using 
> >> iwl3945 (even with hw_scan) but only with ap_scan=1 (while ap_scan=2 
> >> should be used for hidden ssid and thats what nm uses). Non mac80211 
> >> based drivers do not work with ap_scan=1 but with ap_scan=2. So this 
> >> needs to be fixed somehow so that nm can support both wireless stacks.
> >>     
> >
> > Uh so say that again what works where and what doesn't?
> >
> >   
> sorry for being confusing.
> what works:
> connect to a hidden ssid with ap_scan=1 in wpa_supplicant.conf
> what does not work:
> connect to a hidden ssid with ap_scan=2 in wpa_supplicant.conf
> ---
> for non mac80211 drivers its the opposite ie.  ap_scan=2 can connect to 
> hidden ssid while ap_scan=1 works
> (thats also whats documented in the wpa_supplicant docs and what nm uses).
> 
> so NM can't support mac80211 and non mac80211 drivers at the same time 
> without ugly hacks due to this issue.

Let me rant that ap_scan is the single thing that has given me the most
headaches with NetworkManager.  It's simply impossible use correctly on
Linux.  There's _got_ to be a better way to deal with hidden SSIDs.

Dan