Add option for overriding scan result handler for a single scan

wpa_supplicant/events.c

@@ -899,6 +899,13 @@ static void wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
 		return;
 	}
 
+	if (wpa_s->scan_res_handler) {
+		wpa_s->scan_res_handler(wpa_s, scan_res);
+		wpa_s->scan_res_handler = NULL;
+		wpa_scan_results_free(scan_res);
+		return;
+	}
+
 	/*
 	 * Don't post the results if this was the initial cached
 	 * and there were no results.

wpa_supplicant/wpa_supplicant_i.h

@@ -33,6 +33,7 @@ struct wpa_supplicant;
 struct ibss_rsn;
 struct scan_info;
 struct wpa_bss;
+struct wpa_scan_results;
 
 /*
  * Forward declarations of private structures used within the ctrl_iface
@@ -343,6 +344,8 @@ struct wpa_supplicant {
 					  */
 #define WILDCARD_SSID_SCAN ((struct wpa_ssid *) 1)
 
+	void (*scan_res_handler)(struct wpa_supplicant *wpa_s,
+				 struct wpa_scan_results *scan_res);
 	struct dl_list bss; /* struct wpa_bss::list */
 	struct dl_list bss_id; /* struct wpa_bss::list_id */
 	size_t num_bss;