Re: [PATCH] Don't use 802.11r Fast Transition if the driver doesn't support it

On 2/25/2020 7:45 AM, Alex Henrie wrote:
> Since version 1.20, NetworkManager supports 802.11r Fast Transition by
> passing both "wpa-psk-sha256" and "ft-psk" to wpa_supplicant as possible
> authentication mechanisms. However, wireless adapters such as the
> Raspberry Pi 3B's BCM43438 do not support Fast Transition and fail to
> connect when wpa_supplicant tries to use it instead of ordinary (slow)
> authentication. This patch skips over "ft-psk" in
> wpa_supplicant_set_suites if the user's hardware doesn't support it,
> making the latest NetworkManager work seamlessly on the Raspberry Pi.
> 
> There was already a check in wpa_supplicant_set_suites that disables
> Fast Transition if neither SME nor IES is available. However, it is
> evident that support for SME or IES is a necessary but not sufficient
> condition for supporting Fast Transition.
> 
> Signed-off-by: Alex Henrie <[email protected]>
> ---
>   wpa_supplicant/wpa_supplicant.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/wpa_supplicant/wpa_supplicant.c b/wpa_supplicant/wpa_supplicant.c
> index 634fb290e..567dbfe77 100644
> --- a/wpa_supplicant/wpa_supplicant.c
> +++ b/wpa_supplicant/wpa_supplicant.c
> @@ -1460,8 +1460,15 @@ int wpa_supplicant_set_suites(struct wpa_supplicant *wpa_s,
>   #endif /* CONFIG_SAE */
>   #ifdef CONFIG_IEEE80211R
>   	if (!(wpa_s->drv_flags & (WPA_DRIVER_FLAGS_SME |
> -				  WPA_DRIVER_FLAGS_UPDATE_FT_IES)))
> +				  WPA_DRIVER_FLAGS_UPDATE_FT_IES))) {
>   		sel &= ~WPA_KEY_MGMT_FT;
> +	} else {

Not sure why you need an else branch. The if conditions check individual 
bits *not* being set. So I think all if statements can be in same 
indentation level:

	if (!x)
		clear_x;
	if (!y)
		clear_y;
	if (!z)
		clear_z;

Regards,
Arend