v4.19.13 snapshot.
diff --git a/include/linux/if_arp.h b/include/linux/if_arp.h
new file mode 100644
index 0000000..6756fea
--- /dev/null
+++ b/include/linux/if_arp.h
@@ -0,0 +1,63 @@
+/*
+ * 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.
+ *
+ * Global definitions for the ARP (RFC 826) protocol.
+ *
+ * Version: @(#)if_arp.h 1.0.1 04/16/93
+ *
+ * Authors: Original taken from Berkeley UNIX 4.3, (c) UCB 1986-1988
+ * Portions taken from the KA9Q/NOS (v2.00m PA0GRI) source.
+ * Ross Biro
+ * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ * Florian La Roche,
+ * Jonathan Layes <layes@loran.com>
+ * Arnaldo Carvalho de Melo <acme@conectiva.com.br> ARPHRD_HWX25
+ *
+ * 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_IF_ARP_H
+#define _LINUX_IF_ARP_H
+
+#include <linux/skbuff.h>
+#include <uapi/linux/if_arp.h>
+
+static inline struct arphdr *arp_hdr(const struct sk_buff *skb)
+{
+ return (struct arphdr *)skb_network_header(skb);
+}
+
+static inline unsigned int arp_hdr_len(const struct net_device *dev)
+{
+ switch (dev->type) {
+#if IS_ENABLED(CONFIG_FIREWIRE_NET)
+ case ARPHRD_IEEE1394:
+ /* ARP header, device address and 2 IP addresses */
+ return sizeof(struct arphdr) + dev->addr_len + sizeof(u32) * 2;
+#endif
+ default:
+ /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
+ return sizeof(struct arphdr) + (dev->addr_len + sizeof(u32)) * 2;
+ }
+}
+
+static inline bool dev_is_mac_header_xmit(const struct net_device *dev)
+{
+ switch (dev->type) {
+ case ARPHRD_TUNNEL:
+ case ARPHRD_TUNNEL6:
+ case ARPHRD_SIT:
+ case ARPHRD_IPGRE:
+ case ARPHRD_VOID:
+ case ARPHRD_NONE:
+ return false;
+ default:
+ return true;
+ }
+}
+
+#endif /* _LINUX_IF_ARP_H */