Bluetooth: Notify adv monitor added event

This notifies management sockets on MGMT_EV_ADV_MONITOR_ADDED event.

The following test was performed.
- Start two btmgmt consoles, issue a btmgmt advmon-add command on one
console and observe a MGMT_EV_ADV_MONITOR_ADDED event on the other

Signed-off-by: Miao-chen Chou <mcchou@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

net/bluetooth/mgmt.c

@@ -191,6 +191,7 @@ static const u16 mgmt_untrusted_events[] = {
 	MGMT_EV_EXT_INDEX_REMOVED,
 	MGMT_EV_EXT_INFO_CHANGED,
 	MGMT_EV_EXP_FEATURE_CHANGED,
+	MGMT_EV_ADV_MONITOR_ADDED,
 };
 
 #define CACHE_TIMEOUT	msecs_to_jiffies(2 * 1000)
@@ -3977,6 +3978,16 @@ done:
 				 &cp->addr, sizeof(cp->addr));
 }
 
+static void mgmt_adv_monitor_added(struct sock *sk, struct hci_dev *hdev,
+				   u16 handle)
+{
+	struct mgmt_ev_adv_monitor_added ev;
+
+	ev.monitor_handle = cpu_to_le16(handle);
+
+	mgmt_event(MGMT_EV_ADV_MONITOR_ADDED, hdev, &ev, sizeof(ev), sk);
+}
+
 static int read_adv_mon_features(struct sock *sk, struct hci_dev *hdev,
 				 void *data, u16 len)
 {
@@ -4029,8 +4040,8 @@ static int add_adv_patterns_monitor(struct sock *sk, struct hci_dev *hdev,
 	struct mgmt_rp_add_adv_patterns_monitor rp;
 	struct adv_monitor *m = NULL;
 	struct adv_pattern *p = NULL;
+	unsigned int mp_cnt = 0, prev_adv_monitors_cnt;
 	__u8 cp_ofst = 0, cp_len = 0;
-	unsigned int mp_cnt = 0;
 	int err, i;
 
 	BT_DBG("request for %s", hdev->name);
@@ -4094,6 +4105,8 @@ static int add_adv_patterns_monitor(struct sock *sk, struct hci_dev *hdev,
 
 	hci_dev_lock(hdev);
 
+	prev_adv_monitors_cnt = hdev->adv_monitors_cnt;
+
 	err = hci_add_adv_monitor(hdev, m);
 	if (err) {
 		if (err == -ENOSPC) {
@@ -4104,6 +4117,9 @@ static int add_adv_patterns_monitor(struct sock *sk, struct hci_dev *hdev,
 		goto unlock;
 	}
 
+	if (hdev->adv_monitors_cnt > prev_adv_monitors_cnt)
+		mgmt_adv_monitor_added(sk, hdev, m->handle);
+
 	hci_dev_unlock(hdev);
 
 	rp.monitor_handle = cpu_to_le16(m->handle);