1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Global definitions for the ARP (RFC 826) protocol. 7 * 8 * Version: @(#)if_arp.h 1.0.1 04/16/93 9 * 10 * Authors: Original taken from Berkeley UNIX 4.3, (c) UCB 1986-1988 11 * Portions taken from the KA9Q/NOS (v2.00m PA0GRI) source. 12 * Ross Biro 13 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 14 * Florian La Roche, 15 * Jonathan Layes <layes@loran.com> 16 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> ARPHRD_HWX25 17 * 18 * This program is free software; you can redistribute it and/or 19 * modify it under the terms of the GNU General Public License 20 * as published by the Free Software Foundation; either version 21 * 2 of the License, or (at your option) any later version. 22 */ 23 #ifndef _LINUX_IF_ARP_H 24 #define _LINUX_IF_ARP_H 25 26 #include <linux/skbuff.h> 27 #include <uapi/linux/if_arp.h> 28 29 static inline struct arphdr *arp_hdr(const struct sk_buff *skb) 30 { 31 return (struct arphdr *)skb_network_header(skb); 32 } 33 34 static inline int arp_hdr_len(struct net_device *dev) 35 { 36 switch (dev->type) { 37 #if IS_ENABLED(CONFIG_FIREWIRE_NET) 38 case ARPHRD_IEEE1394: 39 /* ARP header, device address and 2 IP addresses */ 40 return sizeof(struct arphdr) + dev->addr_len + sizeof(u32) * 2; 41 #endif 42 default: 43 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 44 return sizeof(struct arphdr) + (dev->addr_len + sizeof(u32)) * 2; 45 } 46 } 47 #endif /* _LINUX_IF_ARP_H */ 48