Fix req_scan-deplete-timeout and update eloop API for this

Commit e2f5a9889a3a2bb8f1eed0cf274c7fbbabe3e9de was supposed to prevent
new scan request from pushing out the old one. However, it did not
really do that since eloop_deplete_timeout() returned 0 both for the
case where the old timeout existed (and was sooner) and if the old
timeout did not exist. It returned 1 only for the case where an old
timeout did exist and was larger than the new requested value. That case
used to result in wpa_supplicant_req_scan() rescheduling the timeout,
but hew code in eloop_deplete_timeout() did the exact same thing and as
such, did not really change anything apart from the debug log message.

Extend the eloop_deplete_timeout() (and eloop_replenish_timeout() for
that matter since it is very similar) to return three different values
based on whether the timeout existed or not and if yes, whether it was
modified. This allows wpa_supplicant_req_scan() to schedule a new
timeout only in the case there was no old timeout.

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

src/ap/sta_info.c

@@ -494,7 +494,7 @@ void ap_sta_replenish_timeout(struct hostapd_data *hapd, struct sta_info *sta,
 			      u32 session_timeout)
 {
 	if (eloop_replenish_timeout(session_timeout, 0,
-				    ap_handle_session_timer, hapd, sta)) {
+				    ap_handle_session_timer, hapd, sta) == 1) {
 		hostapd_logger(hapd, sta->addr, HOSTAPD_MODULE_IEEE80211,
 			       HOSTAPD_LEVEL_DEBUG, "setting session timeout "
 			       "to %d seconds", session_timeout);

src/ap/wps_hostapd.c

@@ -295,7 +295,8 @@ void hostapd_wps_eap_completed(struct hostapd_data *hapd)
 	 * timeout to happen after EAP completion rather than the originally
 	 * scheduled 100 ms after new configuration became known.
 	 */
-	if (eloop_deplete_timeout(0, 0, wps_reload_config, hapd->iface, NULL))
+	if (eloop_deplete_timeout(0, 0, wps_reload_config, hapd->iface, NULL) ==
+	    1)
 		wpa_printf(MSG_DEBUG, "WPS: Reschedule immediate configuration reload");
 }
 

src/utils/eloop.c

@@ -623,10 +623,11 @@ int eloop_deplete_timeout(unsigned int req_secs, unsigned int req_usecs,
 						       user_data);
 				return 1;
 			}
+			return 0;
 		}
 	}
 
-	return 0;
+	return -1;
 }
 
 
@@ -654,10 +655,11 @@ int eloop_replenish_timeout(unsigned int req_secs, unsigned int req_usecs,
 						       user_data);
 				return 1;
 			}
+			return 0;
 		}
 	}
 
-	return 0;
+	return -1;
 }
 
 

src/utils/eloop.h

@@ -229,7 +229,8 @@ int eloop_is_timeout_registered(eloop_timeout_handler handler,
  * @handler: Matching callback function
  * @eloop_data: Matching eloop_data
  * @user_data: Matching user_data
- * Returns: 1 if the timeout is depleted, 0 if no change is made
+ * Returns: 1 if the timeout is depleted, 0 if no change is made, -1 if no
+ * timeout matched
  *
  * Find a registered matching <handler,eloop_data,user_data> timeout. If found,
  * deplete the timeout if remaining time is more than the requested time.
@@ -245,7 +246,8 @@ int eloop_deplete_timeout(unsigned int req_secs, unsigned int req_usecs,
  * @handler: Matching callback function
  * @eloop_data: Matching eloop_data
  * @user_data: Matching user_data
- * Returns: 1 if the timeout is replenished, 0 if no change is made
+ * Returns: 1 if the timeout is replenished, 0 if no change is made, -1 if no
+ * timeout matched
  *
  * Find a registered matching <handler,eloop_data,user_data> timeout. If found,
  * replenish the timeout if remaining time is less than the requested time.

src/utils/eloop_win.c

@@ -378,10 +378,11 @@ int eloop_deplete_timeout(unsigned int req_secs, unsigned int req_usecs,
 						       user_data);
 				return 1;
 			}
+			return 0;
 		}
 	}
 
-	return 0;
+	return -1;
 }
 
 
@@ -409,10 +410,11 @@ int eloop_replenish_timeout(unsigned int req_secs, unsigned int req_usecs,
 						       user_data);
 				return 1;
 			}
+			return 0;
 		}
 	}
 
-	return 0;
+	return -1;
 }
 
 

wpa_supplicant/scan.c

@@ -888,17 +888,19 @@ void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
  */
 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 {
-	if (eloop_deplete_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL))
-	{
-		wpa_dbg(wpa_s, MSG_DEBUG, "Rescheduling scan request: %d sec %d usec",
+	int res = eloop_deplete_timeout(sec, usec, wpa_supplicant_scan, wpa_s,
+					NULL);
+	if (res == 1) {
+		wpa_dbg(wpa_s, MSG_DEBUG, "Rescheduling scan request: %d.%06d sec",
 			sec, usec);
-		return;
+	} else if (res == 0) {
+		wpa_dbg(wpa_s, MSG_DEBUG, "Ignore new scan request for %d.%06d sec since an earlier request is scheduled to trigger sooner",
+			sec, usec);
+	} else {
+		wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d.%06d sec",
+			sec, usec);
+		eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 	}
-
-	wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
-		sec, usec);
-	eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
-	eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 }