cfg80211: allow aborting in-progress connection atttempts

On a disconnect request from userspace, cfg80211 currently calls
called rdev_disconnect() only in case that 'current_bss' was set,
i.e. connection had been established.

Change this to allow the userspace call to succeed and call the
driver's disconnect() method also while the connection attempt is
in progress, to be able to abort attempts.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
[change commit subject/message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -2564,9 +2564,10 @@ struct cfg80211_nan_func {
  *	cases, the result of roaming is indicated with a call to
  *	cfg80211_roamed() or cfg80211_roamed_bss().
  *	(invoked with the wireless_dev mutex held)
- * @disconnect: Disconnect from the BSS/ESS. Once done, call
- *	cfg80211_disconnected().
- *	(invoked with the wireless_dev mutex held)
+ * @disconnect: Disconnect from the BSS/ESS or stop connection attempts if
+ *      connection is in progress. Once done, call cfg80211_disconnected() in
+ *      case connection was already established (invoked with the
+ *      wireless_dev mutex held), otherwise call cfg80211_connect_timeout().
  *
  * @join_ibss: Join the specified IBSS (or create if necessary). Once done, call
  *	cfg80211_ibss_joined(), also call that function when changing BSSID due

net/wireless/sme.c

@@ -1088,7 +1088,7 @@ int cfg80211_disconnect(struct cfg80211_registered_device *rdev,
 		err = cfg80211_sme_disconnect(wdev, reason);
 	else if (!rdev->ops->disconnect)
 		cfg80211_mlme_down(rdev, dev);
-	else if (wdev->current_bss)
+	else if (wdev->ssid_len)
 		err = rdev_disconnect(rdev, dev, reason);
 
 	return err;