v4.19.13 snapshot.
diff --git a/include/linux/in.h b/include/linux/in.h
new file mode 100644
index 0000000..31b4937
--- /dev/null
+++ b/include/linux/in.h
@@ -0,0 +1,104 @@
+/*
+ * 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 of the Internet Protocol.
+ *
+ * Version: @(#)in.h 1.0.1 04/21/93
+ *
+ * Authors: Original taken from the GNU Project <netinet/in.h> file.
+ * 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_IN_H
+#define _LINUX_IN_H
+
+
+#include <linux/errno.h>
+#include <uapi/linux/in.h>
+
+static inline int proto_ports_offset(int proto)
+{
+ switch (proto) {
+ case IPPROTO_TCP:
+ case IPPROTO_UDP:
+ case IPPROTO_DCCP:
+ case IPPROTO_ESP: /* SPI */
+ case IPPROTO_SCTP:
+ case IPPROTO_UDPLITE:
+ return 0;
+ case IPPROTO_AH: /* SPI */
+ return 4;
+ default:
+ return -EINVAL;
+ }
+}
+
+static inline bool ipv4_is_loopback(__be32 addr)
+{
+ return (addr & htonl(0xff000000)) == htonl(0x7f000000);
+}
+
+static inline bool ipv4_is_multicast(__be32 addr)
+{
+ return (addr & htonl(0xf0000000)) == htonl(0xe0000000);
+}
+
+static inline bool ipv4_is_local_multicast(__be32 addr)
+{
+ return (addr & htonl(0xffffff00)) == htonl(0xe0000000);
+}
+
+static inline bool ipv4_is_lbcast(__be32 addr)
+{
+ /* limited broadcast */
+ return addr == htonl(INADDR_BROADCAST);
+}
+
+static inline bool ipv4_is_zeronet(__be32 addr)
+{
+ return (addr & htonl(0xff000000)) == htonl(0x00000000);
+}
+
+/* Special-Use IPv4 Addresses (RFC3330) */
+
+static inline bool ipv4_is_private_10(__be32 addr)
+{
+ return (addr & htonl(0xff000000)) == htonl(0x0a000000);
+}
+
+static inline bool ipv4_is_private_172(__be32 addr)
+{
+ return (addr & htonl(0xfff00000)) == htonl(0xac100000);
+}
+
+static inline bool ipv4_is_private_192(__be32 addr)
+{
+ return (addr & htonl(0xffff0000)) == htonl(0xc0a80000);
+}
+
+static inline bool ipv4_is_linklocal_169(__be32 addr)
+{
+ return (addr & htonl(0xffff0000)) == htonl(0xa9fe0000);
+}
+
+static inline bool ipv4_is_anycast_6to4(__be32 addr)
+{
+ return (addr & htonl(0xffffff00)) == htonl(0xc0586300);
+}
+
+static inline bool ipv4_is_test_192(__be32 addr)
+{
+ return (addr & htonl(0xffffff00)) == htonl(0xc0000200);
+}
+
+static inline bool ipv4_is_test_198(__be32 addr)
+{
+ return (addr & htonl(0xfffe0000)) == htonl(0xc6120000);
+}
+#endif /* _LINUX_IN_H */