Add CTRL-EVENT-SCAN-FAILED notification in case of scan failure

This is needed since the SCAN command with radio work returns before the
actual driver operation to trigger a scan has been executed and as such,
cannot return result of that operation.

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>

src/common/wpa_ctrl.h

@@ -58,6 +58,8 @@ extern "C" {
 #define WPA_EVENT_SCAN_STARTED "CTRL-EVENT-SCAN-STARTED "
 /** New scan results available */
 #define WPA_EVENT_SCAN_RESULTS "CTRL-EVENT-SCAN-RESULTS "
+/** Scan command failed */
+#define WPA_EVENT_SCAN_FAILED "CTRL-EVENT-SCAN-FAILED "
 /** wpa_supplicant state change */
 #define WPA_EVENT_STATE_CHANGE "CTRL-EVENT-STATE-CHANGE "
 /** A new BSS entry was added (followed by BSS entry id and BSSID) */

wpa_supplicant/scan.c

@@ -176,6 +176,8 @@ static void wpas_trigger_scan_cb(struct wpa_radio_work *work, int deinit)
 	if (ret) {
 		wpa_supplicant_notify_scanning(wpa_s, 0);
 		wpas_notify_scan_done(wpa_s, 0);
+		wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_FAILED "ret=%d",
+			     ret);
 		radio_work_done(work);
 		return;
 	}