Allow passive scan to be requested with SCAN passive=1

This allows external programs to request wpa_supplicant to execute
a passive scan (i.e., do not send any Probe Request frames).

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

wpa_supplicant/ctrl_iface.c

@@ -5263,6 +5263,8 @@ static void wpas_ctrl_scan(struct wpa_supplicant *wpa_s, char *params,
 		return;
 	}
 
+	wpa_s->manual_scan_passive = 0;
+
 	if (params) {
 		if (os_strncasecmp(params, "TYPE=ONLY", 9) == 0)
 			wpa_s->scan_res_handler = scan_only_handler;
@@ -5272,6 +5274,10 @@ static void wpas_ctrl_scan(struct wpa_supplicant *wpa_s, char *params,
 			*reply_len = -1;
 			return;
 		}
+
+		pos = os_strstr(params, "passive=");
+		if (pos)
+			wpa_s->manual_scan_passive = !!atoi(pos + 8);
 	} else {
 		os_free(wpa_s->manual_scan_freqs);
 		wpa_s->manual_scan_freqs = NULL;

wpa_supplicant/scan.c

@@ -698,6 +698,9 @@ static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 		wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 			"the scan request");
 		params.num_ssids++;
+	} else if (wpa_s->last_scan_req == MANUAL_SCAN_REQ &&
+		   wpa_s->manual_scan_passive && params.num_ssids == 0) {
+		wpa_dbg(wpa_s, MSG_DEBUG, "Use passive scan based on manual request");
 	} else {
 		wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 		params.num_ssids++;

wpa_supplicant/wpa_supplicant_i.h

@@ -482,6 +482,7 @@ struct wpa_supplicant {
 	int scan_runs; /* number of scan runs since WPS was started */
 	int *next_scan_freqs;
 	int *manual_scan_freqs;
+	unsigned int manual_scan_passive:1;
 	int scan_interval; /* time in sec between scans to find suitable AP */
 	int normal_scans; /* normal scans run before sched_scan */
 	int scan_for_connection; /* whether the scan request was triggered for