diff --git a/include/uapi/linux/hdlc/ioctl.h b/include/uapi/linux/hdlc/ioctl.h
index 0fe4238..b06341a 100644
--- a/include/uapi/linux/hdlc/ioctl.h
+++ b/include/uapi/linux/hdlc/ioctl.h
@@ -79,6 +79,15 @@ typedef struct {
     unsigned int timeout;
 } cisco_proto;
 
+typedef struct {
+	unsigned short dce; /* 1 for DCE (network side) operation */
+	unsigned int modulo; /* modulo (8 = basic / 128 = extended) */
+	unsigned int window; /* frame window size */
+	unsigned int t1; /* timeout t1 */
+	unsigned int t2; /* timeout t2 */
+	unsigned int n2; /* frame retry counter */
+} x25_hdlc_proto;
+
 /* PPP doesn't need any info now - supply length = 0 to ioctl */
 
 #endif /* __ASSEMBLY__ */
diff --git a/include/uapi/linux/if.h b/include/uapi/linux/if.h
index 495cdd2..626da39 100644
--- a/include/uapi/linux/if.h
+++ b/include/uapi/linux/if.h
@@ -210,6 +210,7 @@ struct if_settings {
 		fr_proto		*fr;
 		fr_proto_pvc		*fr_pvc;
 		fr_proto_pvc_info	*fr_pvc_info;
+		x25_hdlc_proto		*x25;
 
 		/* interface settings */
 		sync_serial_settings	*sync;
diff --git a/include/uapi/linux/udp.h b/include/uapi/linux/udp.h
new file mode 100644
index 0000000..d0a7223
--- /dev/null
+++ b/include/uapi/linux/udp.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Definitions for the UDP protocol.
+ *
+ * Version:	@(#)udp.h	1.0.2	04/28/93
+ *
+ * Author:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+#ifndef _LINUX_UDP_H
+#define _LINUX_UDP_H
+
+#include <linux/types.h>
+
+struct udphdr {
+	__be16	source;
+	__be16	dest;
+	__be16	len;
+	__sum16	check;
+};
+
+/* UDP socket options */
+#define UDP_CORK	1	/* Never send partially complete segments */
+#define UDP_ENCAP	100	/* Set the socket to accept encapsulated packets */
+#define UDP_NO_CHECK6_TX 101	/* Disable sending checksum for UDP6X */
+#define UDP_NO_CHECK6_RX 102	/* Disable accpeting checksum for UDP6 */
+#define UDP_SEGMENT	103	/* Set GSO segmentation size */
+#define UDP_GRO		104	/* This socket can receive UDP GRO packets */
+
+/* UDP encapsulation types */
+#define UDP_ENCAP_ESPINUDP_NON_IKE	1 /* draft-ietf-ipsec-nat-t-ike-00/01 */
+#define UDP_ENCAP_ESPINUDP	2 /* draft-ietf-ipsec-udp-encaps-06 */
+#define UDP_ENCAP_L2TPINUDP	3 /* rfc2661 */
+#define UDP_ENCAP_GTP0		4 /* GSM TS 09.60 */
+#define UDP_ENCAP_GTP1U		5 /* 3GPP TS 29.060 */
+#define UDP_ENCAP_RXRPC		6
+#define TCP_ENCAP_ESPINTCP	7 /* Yikes, this is really xfrm encap types. */
+
+#endif /* _LINUX_UDP_H */