v4.19.13 snapshot.
diff --git a/include/net/stp.h b/include/net/stp.h
new file mode 100644
index 0000000..2914e6d
--- /dev/null
+++ b/include/net/stp.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NET_STP_H
+#define _NET_STP_H
+
+struct stp_proto {
+	unsigned char	group_address[ETH_ALEN];
+	void		(*rcv)(const struct stp_proto *, struct sk_buff *,
+			       struct net_device *);
+	void		*data;
+};
+
+int stp_proto_register(const struct stp_proto *proto);
+void stp_proto_unregister(const struct stp_proto *proto);
+
+#endif /* _NET_STP_H */