--- zzzz-none-000/linux-4.9.218/include/uapi/linux/l2tp.h	2020-04-02 15:20:41.000000000 +0000
+++ seale-7590ax-750/linux-4.9.218/include/uapi/linux/l2tp.h	2023-03-29 10:59:08.000000000 +0000
@@ -108,7 +108,7 @@
 	L2TP_ATTR_VLAN_ID,		/* u16 */
 	L2TP_ATTR_COOKIE,		/* 0, 4 or 8 bytes */
 	L2TP_ATTR_PEER_COOKIE,		/* 0, 4 or 8 bytes */
-	L2TP_ATTR_DEBUG,		/* u32 */
+	L2TP_ATTR_DEBUG,		/* u32, enum l2tp_debug_flags */
 	L2TP_ATTR_RECV_SEQ,		/* u8 */
 	L2TP_ATTR_SEND_SEQ,		/* u8 */
 	L2TP_ATTR_LNS_MODE,		/* u8 */
@@ -175,6 +175,21 @@
 	L2TP_SEQ_ALL = 2,
 };
 
+/**
+ * enum l2tp_debug_flags - debug message categories for L2TP tunnels/sessions
+ *
+ * @L2TP_MSG_DEBUG: verbose debug (if compiled in)
+ * @L2TP_MSG_CONTROL: userspace - kernel interface
+ * @L2TP_MSG_SEQ: sequence numbers
+ * @L2TP_MSG_DATA: data packets
+ */
+enum l2tp_debug_flags {
+	L2TP_MSG_DEBUG		= (1 << 0),
+	L2TP_MSG_CONTROL	= (1 << 1),
+	L2TP_MSG_SEQ		= (1 << 2),
+	L2TP_MSG_DATA		= (1 << 3),
+};
+
 /*
  * NETLINK_GENERIC related info
  */