File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/net/wireless/ap.c b/net/wireless/ap.c
new file mode 100644
index 0000000..bdad1f9
--- /dev/null
+++ b/net/wireless/ap.c
@@ -0,0 +1,51 @@
+#include <linux/ieee80211.h>
+#include <linux/export.h>
+#include <net/cfg80211.h>
+#include "nl80211.h"
+#include "core.h"
+#include "rdev-ops.h"
+
+
+int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
+		       struct net_device *dev, bool notify)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	int err;
+
+	ASSERT_WDEV_LOCK(wdev);
+
+	if (!rdev->ops->stop_ap)
+		return -EOPNOTSUPP;
+
+	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_AP &&
+	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
+		return -EOPNOTSUPP;
+
+	if (!wdev->beacon_interval)
+		return -ENOENT;
+
+	err = rdev_stop_ap(rdev, dev);
+	if (!err) {
+		wdev->beacon_interval = 0;
+		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);
+	}
+
+	return err;
+}
+
+int cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
+		     struct net_device *dev, bool notify)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	int err;
+
+	wdev_lock(wdev);
+	err = __cfg80211_stop_ap(rdev, dev, notify);
+	wdev_unlock(wdev);
+
+	return err;
+}