Bluetooth: Track the AES-CCM encryption status of LE and BR/EDR links

When encryption for LE links has been enabled, it will always be use
AES-CCM encryption. In case of BR/EDR Secure Connections, the link
will also use AES-CCM encryption. In both cases track the AES-CCM
status in the connection flags.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

include/net/bluetooth/hci_core.h

@@ -448,6 +448,7 @@ enum {
 	HCI_CONN_MGMT_CONNECTED,
 	HCI_CONN_SSP_ENABLED,
 	HCI_CONN_SC_ENABLED,
+	HCI_CONN_AES_CCM,
 	HCI_CONN_POWER_SAVE,
 	HCI_CONN_REMOTE_OOB,
 	HCI_CONN_6LOWPAN,

net/bluetooth/hci_event.c

@@ -1997,8 +1997,14 @@ static void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff *skb)
 			conn->link_mode |= HCI_LM_AUTH;
 			conn->link_mode |= HCI_LM_ENCRYPT;
 			conn->sec_level = conn->pending_sec_level;
-		} else
+
+			if ((conn->type == ACL_LINK && ev->encrypt == 0x02) ||
+			    conn->type == LE_LINK)
+				set_bit(HCI_CONN_AES_CCM, &conn->flags);
+		} else {
 			conn->link_mode &= ~HCI_LM_ENCRYPT;
+			clear_bit(HCI_CONN_AES_CCM, &conn->flags);
+		}
 	}
 
 	clear_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags);