Add 'SCAN TYPE=ONLY' functionality

Usual manual scan request may cause reassociation due to several
reasons. New command is intended to perform pure scan without taking any
automatic action based on the results.

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

wpa_supplicant/ctrl_iface.c

@@ -5125,10 +5125,14 @@ char * wpa_supplicant_ctrl_iface_process(struct wpa_supplicant *wpa_s,
 		wpa_supplicant_cancel_scan(wpa_s);
 		wpa_supplicant_deauthenticate(wpa_s,
 					      WLAN_REASON_DEAUTH_LEAVING);
-	} else if (os_strcmp(buf, "SCAN") == 0) {
+	} else if (os_strcmp(buf, "SCAN") == 0 ||
+		   os_strncmp(buf, "SCAN ", 5) == 0) {
 		if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED)
 			reply_len = -1;
 		else {
+			if (os_strlen(buf) > 4 &&
+			    os_strncasecmp(buf + 5, "TYPE=ONLY", 9) == 0)
+				wpa_s->scan_res_handler = scan_only_handler;
 			if (!wpa_s->sched_scanning && !wpa_s->scanning &&
 			    ((wpa_s->wpa_state <= WPA_SCANNING) ||
 			     (wpa_s->wpa_state == WPA_COMPLETED))) {

wpa_supplicant/events.c

@@ -1125,7 +1125,8 @@ static int _wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
 						   data ? &data->scan_info :
 						   NULL, 1);
 	if (scan_res == NULL) {
-		if (wpa_s->conf->ap_scan == 2 || ap)
+		if (wpa_s->conf->ap_scan == 2 || ap ||
+		    wpa_s->scan_res_handler == scan_only_handler)
 			return -1;
 		wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results - try "
 			"scanning again");

wpa_supplicant/scan.c

@@ -11,6 +11,7 @@
 #include "utils/common.h"
 #include "utils/eloop.h"
 #include "common/ieee802_11_defs.h"
+#include "common/wpa_ctrl.h"
 #include "config.h"
 #include "wpa_supplicant_i.h"
 #include "driver_i.h"
@@ -1580,3 +1581,16 @@ int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
 
 	return 0;
 }
+
+
+/**
+ * scan_only_handler - Reports scan results
+ */
+void scan_only_handler(struct wpa_supplicant *wpa_s,
+		       struct wpa_scan_results *scan_res)
+{
+	wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
+	wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
+	wpas_notify_scan_results(wpa_s);
+	wpas_notify_scan_done(wpa_s, 1);
+}

wpa_supplicant/scan.h

@@ -33,5 +33,7 @@ struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
 				      const u8 *bssid);
 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec);
+void scan_only_handler(struct wpa_supplicant *wpa_s,
+		       struct wpa_scan_results *scan_res);
 
 #endif /* SCAN_H */

wpa_supplicant/wpa_cli.c

@@ -1433,7 +1433,7 @@ static int wpa_cli_cmd_save_config(struct wpa_ctrl *ctrl, int argc,
 
 static int wpa_cli_cmd_scan(struct wpa_ctrl *ctrl, int argc, char *argv[])
 {
-	return wpa_ctrl_command(ctrl, "SCAN");
+	return wpa_cli_cmd(ctrl, "SCAN", 0, argc, argv);
 }