include/linux/neighbour.h

#ifndef __LINUX_NEIGHBOUR_H
#define __LINUX_NEIGHBOUR_H

#include <linux/netlink.h>

struct ndmsg
{
	__u8		ndm_family;
	__u8		ndm_pad1;
	__u16		ndm_pad2;
	__s32		ndm_ifindex;
	__u16		ndm_state;
	__u8		ndm_flags;
	__u8		ndm_type;
};

enum
{
	NDA_UNSPEC,
	NDA_DST,
	NDA_LLADDR,
	NDA_CACHEINFO,
	NDA_PROBES,
	__NDA_MAX
};

#define NDA_MAX (__NDA_MAX - 1)

/*
 *	Neighbor Cache Entry Flags
 */

#define NTF_PROXY	0x08	/* == ATF_PUBL */
#define NTF_ROUTER	0x80

/*
 *	Neighbor Cache Entry States.
 */

#define NUD_INCOMPLETE	0x01
#define NUD_REACHABLE	0x02
#define NUD_STALE	0x04
#define NUD_DELAY	0x08
#define NUD_PROBE	0x10
#define NUD_FAILED	0x20

/* Dummy states */
#define NUD_NOARP	0x40
#define NUD_PERMANENT	0x80
#define NUD_NONE	0x00

/* NUD_NOARP & NUD_PERMANENT are pseudostates, they never change
   and make no address resolution or NUD.
   NUD_PERMANENT is also cannot be deleted by garbage collectors.
 */

struct nda_cacheinfo
{
	__u32		ndm_confirmed;
	__u32		ndm_used;
	__u32		ndm_updated;
	__u32		ndm_refcnt;
};

#endif