Bluetooth: mgmt: Translate HCI reason in Device Disconnected event

MGMT_EV_DEVICE_DISCONNECTED carries a reason field which is defined to
be one of MGMT_DEV_DISCONN_* (0x00..0x05). hci_disconn_complete_evt()
converts the HCI error with hci_to_mgmt_reason(), but two other paths
pass the raw HCI error straight through:

  hci_cs_disconnect()   -> cp->reason
  mgmt_connect_failed() -> status

The latter is reached whenever the adapter is powered off or suspended:
hci_disconnect_all_sync() aborts every link with
HCI_ERROR_REMOTE_POWER_OFF, hci_disconnect_sync() deliberately does not
wait for HCI_EV_DISCONN_COMPLETE for that reason, so that
hci_abort_conn_sync() finishes the connection off through
hci_conn_failed() instead.

As a result userspace sees an out of range reason:

  @ MGMT Event: Device Disconnected (0x000c) plen 8
        BR/EDR Address: 8C:A9:6F:2C:51:46
        Reason: Reserved (0x15)

  bluetoothd: btd_bearer_disconnected() Unknown disconnection value: 21
  bluetoothd: device_disconnected() Unknown disconnection value: 21

Export hci_to_mgmt_reason() and use it in both places, so that a power
off is reported as MGMT_DEV_DISCONN_REMOTE rather than as the raw
HCI_ERROR_REMOTE_POWER_OFF (0x15).

Fixes: d47da6bd4cfa ("Bluetooth: hci_core: Fix sending MGMT_EV_CONNECT_FAILED")
Fixes: 182ee45da083 ("Bluetooth: hci_sync: Rework hci_suspend_notifier")
Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

include/net/bluetooth/hci_core.h

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 4ca0929..e7133ff 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -2430,6 +2430,7 @@ void mgmt_new_link_key(struct hci_dev *hdev, struct link_key *key,
 		       bool persistent);
 void mgmt_device_connected(struct hci_dev *hdev, struct hci_conn *conn,
 			   u8 *name, u8 name_len);
+u8 hci_to_mgmt_reason(u8 err);
 void mgmt_device_disconnected(struct hci_dev *hdev, bdaddr_t *bdaddr,
 			      u8 link_type, u8 addr_type, u8 reason,
 			      bool mgmt_connected);

net/bluetooth/hci_event.c

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 5b867aa..ea85839 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2766,7 +2766,7 @@ static void hci_cs_disconnect(struct hci_dev *hdev, u8 status)
 	}
 
 	mgmt_device_disconnected(hdev, &conn->dst, conn->type, conn->dst_type,
-				 cp->reason, mgmt_conn);
+				 hci_to_mgmt_reason(cp->reason), mgmt_conn);
 
 	hci_disconn_cfm(conn, cp->reason);
 
@@ -3384,22 +3384,6 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
 	hci_dev_unlock(hdev);
 }
 
-static u8 hci_to_mgmt_reason(u8 err)
-{
-	switch (err) {
-	case HCI_ERROR_CONNECTION_TIMEOUT:
-		return MGMT_DEV_DISCONN_TIMEOUT;
-	case HCI_ERROR_REMOTE_USER_TERM:
-	case HCI_ERROR_REMOTE_LOW_RESOURCES:
-	case HCI_ERROR_REMOTE_POWER_OFF:
-		return MGMT_DEV_DISCONN_REMOTE;
-	case HCI_ERROR_LOCAL_HOST_TERM:
-		return MGMT_DEV_DISCONN_LOCAL_HOST;
-	default:
-		return MGMT_DEV_DISCONN_UNKNOWN;
-	}
-}
-
 static void hci_disconn_complete_evt(struct hci_dev *hdev, void *data,
 				     struct sk_buff *skb)
 {

net/bluetooth/mgmt.c

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 23a1ade..1db10e0 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -9908,6 +9908,22 @@ bool mgmt_powering_down(struct hci_dev *hdev)
 	return false;
 }
 
+u8 hci_to_mgmt_reason(u8 err)
+{
+	switch (err) {
+	case HCI_ERROR_CONNECTION_TIMEOUT:
+		return MGMT_DEV_DISCONN_TIMEOUT;
+	case HCI_ERROR_REMOTE_USER_TERM:
+	case HCI_ERROR_REMOTE_LOW_RESOURCES:
+	case HCI_ERROR_REMOTE_POWER_OFF:
+		return MGMT_DEV_DISCONN_REMOTE;
+	case HCI_ERROR_LOCAL_HOST_TERM:
+		return MGMT_DEV_DISCONN_LOCAL_HOST;
+	default:
+		return MGMT_DEV_DISCONN_UNKNOWN;
+	}
+}
+
 void mgmt_device_disconnected(struct hci_dev *hdev, bdaddr_t *bdaddr,
 			      u8 link_type, u8 addr_type, u8 reason,
 			      bool mgmt_connected)
@@ -9969,7 +9985,8 @@ void mgmt_connect_failed(struct hci_dev *hdev, struct hci_conn *conn, u8 status)
 
 	if (test_and_clear_bit(HCI_CONN_MGMT_CONNECTED, &conn->flags)) {
 		mgmt_device_disconnected(hdev, &conn->dst, conn->type,
-					 conn->dst_type, status, true);
+					 conn->dst_type,
+					 hci_to_mgmt_reason(status), true);
 		return;
 	}