Add CTRL-EVENT-SIGNAL-CHANGE for bgscan signal update events

This allows external programs to monitor driver signal change events
through wpa_supplicant when bgscan is used.

Signed-off-by: Jouni Malinen <j@w1.fi>

src/common/wpa_ctrl.h

@@ -64,6 +64,8 @@ extern "C" {
 #define WPA_EVENT_BSS_ADDED "CTRL-EVENT-BSS-ADDED "
 /** A BSS entry was removed (followed by BSS entry id and BSSID) */
 #define WPA_EVENT_BSS_REMOVED "CTRL-EVENT-BSS-REMOVED "
+/** Change in the signal level was reported by the driver */
+#define WPA_EVENT_SIGNAL_CHANGE "CTRL-EVENT-SIGNAL-CHANGE "
 
 /** RSN IBSS 4-way handshakes completed with specified peer */
 #define IBSS_RSN_COMPLETED "IBSS-RSN-COMPLETED "

wpa_supplicant/events.c

@@ -3268,6 +3268,12 @@ void wpa_supplicant_event(void *ctx, enum wpa_event_type event,
 					data->eapol_rx.data_len);
 		break;
 	case EVENT_SIGNAL_CHANGE:
+		wpa_msg(wpa_s, MSG_INFO, WPA_EVENT_SIGNAL_CHANGE
+			"above=%d signal=%d noise=%d txrate=%d",
+			data->signal_change.above_threshold,
+			data->signal_change.current_signal,
+			data->signal_change.current_noise,
+			data->signal_change.current_txrate);
 		bgscan_notify_signal_change(
 			wpa_s, data->signal_change.above_threshold,
 			data->signal_change.current_signal,