cfg80211: send stop AP event only due to internal reason

Commit "nl80211: send event when AP operation is stopped" added an
event to notify user space that an AP interface has been stopped, to
handle cases such as suspend etc. The event is sent regardless
if the stop AP flow was triggered by user space or due to internal state
change.

This might cause issues with wpa_supplicant/hostapd flows that consider
stop AP flow as a synchronous one, e.g., AP/GO channel change in the
absence of CSA support. In such cases, the flow will restart the AP
immediately after the stop AP flow is done, and only handle the stop
AP event after the current flow is done, and as a result stop the AP
again.

Change the current implementation to only send the event in case the
stop AP was triggered due to an internal reason.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/ap.c

@@ -7,7 +7,7 @@
 
 
 static int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
-			      struct net_device *dev)
+			      struct net_device *dev, bool notify)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;
@@ -30,6 +30,7 @@ static int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
 		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
 		wdev->ssid_len = 0;
 		rdev_set_qos_map(rdev, dev, NULL);
+		if (notify)
 			nl80211_send_ap_stopped(wdev);
 	}
 
@@ -37,13 +38,13 @@ static int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
 }
 
 int cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
-		     struct net_device *dev)
+		     struct net_device *dev, bool notify)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;
 
 	wdev_lock(wdev);
-	err = __cfg80211_stop_ap(rdev, dev);
+	err = __cfg80211_stop_ap(rdev, dev, notify);
 	wdev_unlock(wdev);
 
 	return err;

net/wireless/core.c

@@ -783,7 +783,7 @@ void cfg80211_leave(struct cfg80211_registered_device *rdev,
 		break;
 	case NL80211_IFTYPE_AP:
 	case NL80211_IFTYPE_P2P_GO:
-		cfg80211_stop_ap(rdev, dev);
+		cfg80211_stop_ap(rdev, dev, true);
 		break;
 	default:
 		break;

net/wireless/core.h

@@ -283,7 +283,7 @@ int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 
 /* AP */
 int cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
-		     struct net_device *dev);
+		     struct net_device *dev, bool notify);
 
 /* MLME */
 int cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,

net/wireless/nl80211.c

@@ -3332,7 +3332,7 @@ static int nl80211_stop_ap(struct sk_buff *skb, struct genl_info *info)
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
 	struct net_device *dev = info->user_ptr[1];
 
-	return cfg80211_stop_ap(rdev, dev);
+	return cfg80211_stop_ap(rdev, dev, false);
 }
 
 static const struct nla_policy sta_flags_policy[NL80211_STA_FLAG_MAX + 1] = {

net/wireless/util.c

@@ -886,7 +886,7 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
 
 		switch (otype) {
 		case NL80211_IFTYPE_AP:
-			cfg80211_stop_ap(rdev, dev);
+			cfg80211_stop_ap(rdev, dev, true);
 			break;
 		case NL80211_IFTYPE_ADHOC:
 			cfg80211_leave_ibss(rdev, dev, false);