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 
arp_hdr(const struct sk_buff * skb)25 static inline struct arphdr *arp_hdr(const struct sk_buff *skb)
26 {
27 	return (struct arphdr *)skb_network_header(skb);
28 }
29 
arp_hdr_len(const struct net_device * dev)30 static 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 
dev_is_mac_header_xmit(const struct net_device * dev)44 static 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