[PATCH 2/2] Update IE after association regardless driver roaming support

Jouni Malinen j at w1.fi
Fri Jan 17 04:32:49 EST 2014


On Wed, Jan 15, 2014 at 10:30:12AM -0800, Dmitry Shmidt wrote:
> Update IE is necessary if roaming is done by driver / FW, but will
> not harm in other case

Could you please clarify why this would not do harm in other cases? The
WPA_DRIVER_FLAGS_BSS_SELECTION case is know to require this which is why
the IE update code is there. However, it is not known whether there
could be drivers that do not have correct information in scan results
for all cases (e.g., some of the hidden SSID/multi-SSID cases could be a
bit risky in this area). Consequently, I could see this change
potentially breaking some working cases. Since I see no real
justification for this change, I'd rather not add it.

Drivers that do BSS selection in the driver/firmware better indicate
that to the user space and the real fix here would be to make any driver
that could today need this change work properly in this area. Working
around them with a change in wpa_supplicant is not justifiable if there
is risk in breaking something for other drivers.

As far as being able to fix one known driver misbehavior in this area,
there is already a change in upstream kernel moving ahead with the
BSSID/frequency hint attributes. Once that hits wireless-testing.git, we
can add the wpa_supplicant changes to provide that information to the
driver even when WPA_DRIVER_FLAGS_BSS_SELECTION is advertised. That will
hopefully remove any assumed need for not advertising this capability
correctly.

-- 
Jouni Malinen                                            PGP id EFC895FA


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