/*
   * 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 int arp_hdr_len(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;
  	}
  }
  #endif	/* _LINUX_IF_ARP_H */