xref: /linux/include/linux/if_arp.h (revision bfd5bb6f90af092aa345b15cd78143956a13c2a8)
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 unsigned int arp_hdr_len(const 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 
48 static inline bool dev_is_mac_header_xmit(const struct net_device *dev)
49 {
50 	switch (dev->type) {
51 	case ARPHRD_TUNNEL:
52 	case ARPHRD_TUNNEL6:
53 	case ARPHRD_SIT:
54 	case ARPHRD_IPGRE:
55 	case ARPHRD_VOID:
56 	case ARPHRD_NONE:
57 		return false;
58 	default:
59 		return true;
60 	}
61 }
62 
63 #endif	/* _LINUX_IF_ARP_H */
64