Bluetooth: Add support for Local OOB Extended Data Update events

When a different user requests a new set of local out-of-band data, then
inform all previous users that the data has been updated. To limit the
scope of users, the updates are limited to previous users. If a user has
never requested out-of-band data, it will also not see the update.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

include/net/bluetooth/hci.h

@@ -186,6 +186,7 @@ enum {
 	HCI_MGMT_UNCONF_INDEX_EVENTS,
 	HCI_MGMT_EXT_INDEX_EVENTS,
 	HCI_MGMT_GENERIC_EVENTS,
+	HCI_MGMT_OOB_DATA_EVENTS,
 };
 
 /*

include/net/bluetooth/mgmt.h

@@ -735,3 +735,10 @@ struct mgmt_ev_ext_index {
 #define MGMT_EV_EXT_INDEX_ADDED		0x0020
 
 #define MGMT_EV_EXT_INDEX_REMOVED	0x0021
+
+#define MGMT_EV_LOCAL_OOB_DATA_UPDATED	0x0022
+struct mgmt_ev_local_oob_data_updated {
+	__u8    type;
+	__le16	eir_len;
+	__u8	eir[0];
+} __packed;

net/bluetooth/mgmt.c

@@ -133,6 +133,7 @@ static const u16 mgmt_events[] = {
 	MGMT_EV_NEW_CONFIG_OPTIONS,
 	MGMT_EV_EXT_INDEX_ADDED,
 	MGMT_EV_EXT_INDEX_REMOVED,
+	MGMT_EV_LOCAL_OOB_DATA_UPDATED,
 };
 
 #define CACHE_TIMEOUT	msecs_to_jiffies(2 * 1000)
@@ -262,6 +263,13 @@ static int mgmt_index_event(u16 event, struct hci_dev *hdev, void *data,
 			       flag, NULL);
 }
 
+static int mgmt_limited_event(u16 event, struct hci_dev *hdev, void *data,
+			      u16 len, int flag, struct sock *skip_sk)
+{
+	return mgmt_send_event(event, hdev, HCI_CHANNEL_CONTROL, data, len,
+			       flag, skip_sk);
+}
+
 static int mgmt_generic_event(u16 event, struct hci_dev *hdev, void *data,
 			      u16 len, struct sock *skip_sk)
 {
@@ -6387,8 +6395,16 @@ static int read_local_oob_ext_data(struct sock *sk, struct hci_dev *hdev,
 
 	hci_dev_unlock(hdev);
 
+	hci_sock_set_flag(sk, HCI_MGMT_OOB_DATA_EVENTS);
+
 	err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_READ_LOCAL_OOB_EXT_DATA,
 				MGMT_STATUS_SUCCESS, rp, sizeof(*rp) + eir_len);
+	if (err < 0)
+		goto done;
+
+	err = mgmt_limited_event(MGMT_EV_LOCAL_OOB_DATA_UPDATED, hdev,
+				 rp, sizeof(*rp) + eir_len,
+				 HCI_MGMT_OOB_DATA_EVENTS, sk);
 
 done:
 	kfree(rp);