[PATCH 2/4] hostapd: add RSSI based association rejection support

[Jouni Malinen]

On Mon, Aug 21, 2017 at 07:43:53PM +0300, Andrei Otcheretianski wrote:
> An AP might reject a STA association request due to low RSSI.
> In such case, the AP informs the STA the desired RSSI improvement and a retry
> timeout. The STA might retry to associate even if the RSSI hasn't improved
> if the retry timeout expired.

> diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c

> @@ -2931,6 +2938,12 @@ static void handle_assoc(struct hostapd_data *hapd,
>  	}
>  
>  	sta = ap_get_sta(hapd, mgmt->sa);
> +
> +	if (hapd->iconf->rssi_reject_assoc_rssi &&
> +	    rssi < hapd->iconf->rssi_reject_assoc_rssi) {
> +		resp = WLAN_STATUS_DENIED_POOR_CHANNEL_CONDITIONS;
> +		goto fail;
> +	}

Making a decision to reject an association based on the RSSI of a single
frame sounds like a bad idea to me. That value can vary a lot from frame
to frame.. At minimum, I'd expect the AP to include the RSSI of the
Authentication frame received just before this (Re)Association Request
frame and reject the association only if both those frames show too low
RSSI.

-- 
Jouni Malinen                                            PGP id EFC895FA