wpa_supplicant: Use relative time for TKIP Michael MIC failures

The MMIC failure code should use monotonic time to check
whether 60 seconds have elapsed or not. For type-safety,
use struct os_reltime for the timestamp variable, and
also convert to using os_reltime_expired().

Signed-hostap: Johannes Berg <johannes.berg@intel.com>

wpa_supplicant/events.c

@@ -2183,13 +2183,13 @@ wpa_supplicant_event_michael_mic_failure(struct wpa_supplicant *wpa_s,
 					 union wpa_event_data *data)
 {
 	int pairwise;
-	struct os_time t;
+	struct os_reltime t;
 
 	wpa_msg(wpa_s, MSG_WARNING, "Michael MIC failure detected");
 	pairwise = (data && data->michael_mic_failure.unicast);
-	os_get_time(&t);
-	if ((wpa_s->last_michael_mic_error &&
-	     t.sec - wpa_s->last_michael_mic_error <= 60) ||
+	os_get_reltime(&t);
+	if ((wpa_s->last_michael_mic_error.sec &&
+	     !os_reltime_expired(&t, &wpa_s->last_michael_mic_error, 60)) ||
 	    wpa_s->pending_mic_error_report) {
 		if (wpa_s->pending_mic_error_report) {
 			/*
@@ -2267,7 +2267,7 @@ wpa_supplicant_event_michael_mic_failure(struct wpa_supplicant *wpa_s,
 		wpa_sm_key_request(wpa_s->wpa, 1, pairwise);
 #endif /* CONFIG_DELAYED_MIC_ERROR_REPORT */
 	}
-	wpa_s->last_michael_mic_error = t.sec;
+	wpa_s->last_michael_mic_error = t;
 	wpa_s->mic_errors_seen++;
 }
 

wpa_supplicant/wpa_supplicant_i.h

@@ -344,7 +344,7 @@ struct wpa_supplicant {
 	char *confanother;
 	struct wpa_config *conf;
 	int countermeasures;
-	os_time_t last_michael_mic_error;
+	struct os_reltime last_michael_mic_error;
 	u8 bssid[ETH_ALEN];
 	u8 pending_bssid[ETH_ALEN]; /* If wpa_state == WPA_ASSOCIATING, this
 				     * field contains the target BSSID. */