supplicant: Assume external scans complete within 30 seconds.

When testing relatively buggy ath10k driver and firmware,
I saw cases where supplicant thought external scans were
active when in fact none were.  This effectively hangs supplicant
because it will never again scan to start the association logic.

This patch times out external scans after 30 seconds and continues
on as if the external scan had completed.

Signed-off-by: Ben Greear <greearb@candelatech.com>

wpa_supplicant/events.c

@@ -3432,6 +3432,7 @@ void wpa_supplicant_event(void *ctx, enum wpa_event_type event,
 		} else {
 			wpa_dbg(wpa_s, MSG_DEBUG, "External program started a scan");
 			wpa_s->radio->external_scan_running = 1;
+			os_get_reltime(&wpa_s->external_scan_start_time);
 			wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_STARTED);
 		}
 		break;

wpa_supplicant/wpa_supplicant.c

@@ -4246,8 +4246,21 @@ static void radio_start_next_work(void *eloop_ctx, void *timeout_ctx)
 			return; /* already started and still in progress */
 
 		if (wpa_s && wpa_s->radio->external_scan_running) {
-			wpa_printf(MSG_DEBUG, "Delay radio work start until externally triggered scan completes");
-			return;
+			/* If external scan has been running too long, then continue with our own,
+			 * we must have missed the scan-completed event somehow..or buggy os/driver
+			 * did not deliver it.
+			 */
+			struct os_reltime now, diff;
+			os_get_reltime(&now);
+			os_reltime_sub(&now, &wpa_s->external_scan_start_time, &diff);
+			if (diff.sec > 30) {
+				wpa_msg(wpa_s, MSG_INFO, "External scan took too long: %ld.%06ld seconds, will assume it is completed.",
+					diff.sec, diff.usec);
+				wpa_s->radio->external_scan_running = 0;
+			} else {
+				wpa_msg(wpa_s, MSG_DEBUG, "Delay radio work start until externally triggered scan completes");
+				return;
+			}
 		}
 	} else {
 		work = NULL;

wpa_supplicant/wpa_supplicant_i.h

@@ -617,6 +617,7 @@ struct wpa_supplicant {
 	struct os_reltime scan_trigger_time, scan_start_time;
 	/* Minimum freshness requirement for connection purposes */
 	struct os_reltime scan_min_time;
+	struct os_reltime external_scan_start_time;
 	int scan_runs; /* number of scan runs since WPS was started */
 	int *next_scan_freqs;
 	int *manual_scan_freqs;