1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Global definitions for the ARP (RFC 826) protocol.
8 *
9 * Version: @(#)if_arp.h 1.0.1 04/16/93
10 *
11 * Authors: Original taken from Berkeley UNIX 4.3, (c) UCB 1986-1988
12 * Portions taken from the KA9Q/NOS (v2.00m PA0GRI) source.
13 * Ross Biro
14 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
15 * Florian La Roche,
16 * Jonathan Layes <layes@loran.com>
17 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> ARPHRD_HWX25
18 */
19#ifndef _LINUX_IF_ARP_H
20#define _LINUX_IF_ARP_H
21
22#include <linux/skbuff.h>
23#include <uapi/linux/if_arp.h>
24
25static inline struct arphdr *arp_hdr(const struct sk_buff *skb)
26{
27 return (struct arphdr *)skb_network_header(skb);
28}
29
30static inline unsigned int arp_hdr_len(const struct net_device *dev)
31{
32 switch (dev->type) {
33#if IS_ENABLED(CONFIG_FIREWIRE_NET)
34 case ARPHRD_IEEE1394:
35 /* ARP header, device address and 2 IP addresses */
36 return sizeof(struct arphdr) + dev->addr_len + sizeof(u32) * 2;
37#endif
38 default:
39 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
40 return sizeof(struct arphdr) + (dev->addr_len + sizeof(u32)) * 2;
41 }
42}
43
44static inline bool dev_is_mac_header_xmit(const struct net_device *dev)
45{
46 switch (dev->type) {
47 case ARPHRD_TUNNEL:
48 case ARPHRD_TUNNEL6:
49 case ARPHRD_SIT:
50 case ARPHRD_IPGRE:
51 case ARPHRD_IP6GRE:
52 case ARPHRD_VOID:
53 case ARPHRD_NONE:
54 case ARPHRD_RAWIP:
55 case ARPHRD_PIMREG:
56 /* PPP adds its l2 header automatically in ppp_start_xmit().
57 * This makes it look like an l3 device to __bpf_redirect() and tcf_mirred_init().
58 */
59 case ARPHRD_PPP:
60 return false;
61 default:
62 return true;
63 }
64}
65
66#endif /* _LINUX_IF_ARP_H */
67