LXR linux/include/linux/if

   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
  29static inline struct arphdr *arp_hdr(const struct sk_buff *skb)
  30{
  31        return (struct arphdr *)skb_network_header(skb);
  32}
  33
  34static 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