include/uapi/linux/neighbour.h

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef __LINUX_NEIGHBOUR_H
#define __LINUX_NEIGHBOUR_H

#include <linux/types.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_VLAN,
	NDA_PORT,
	NDA_VNI,
	NDA_IFINDEX,
	NDA_MASTER,
	NDA_LINK_NETNSID,
	NDA_SRC_VNI,
	NDA_PROTOCOL,  /* Originator of entry */
	NDA_NH_ID,
	NDA_FDB_EXT_ATTRS,
	NDA_FLAGS_EXT,
	NDA_NDM_STATE_MASK,
	NDA_NDM_FLAGS_MASK,
	__NDA_MAX
};

#define NDA_MAX (__NDA_MAX - 1)

/*
 *	Neighbor Cache Entry Flags
 */

#define NTF_USE		(1 << 0)
#define NTF_SELF	(1 << 1)
#define NTF_MASTER	(1 << 2)
#define NTF_PROXY	(1 << 3)	/* == ATF_PUBL */
#define NTF_EXT_LEARNED	(1 << 4)
#define NTF_OFFLOADED   (1 << 5)
#define NTF_STICKY	(1 << 6)
#define NTF_ROUTER	(1 << 7)
/* Extended flags under NDA_FLAGS_EXT: */
#define NTF_EXT_MANAGED	(1 << 0)

/*
 *	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 also cannot be deleted by garbage collectors. This holds true
 * for dynamic entries with NTF_EXT_LEARNED flag as well. However, upon carrier
 * down event, NUD_PERMANENT entries are not flushed whereas NTF_EXT_LEARNED
 * flagged entries explicitly are (which is also consistent with the routing
 * subsystem).
 *
 * When NTF_EXT_LEARNED is set for a bridge fdb entry the different cache entry
 * states don't make sense and thus are ignored. Such entries don't age and
 * can roam.
 *
 * NTF_EXT_MANAGED flagged neigbor entries are managed by the kernel on behalf
 * of a user space control plane, and automatically refreshed so that (if
 * possible) they remain in NUD_REACHABLE state.
 */

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

/*****************************************************************
 *		Neighbour tables specific messages.
 *
 * To retrieve the neighbour tables send RTM_GETNEIGHTBL with the
 * NLM_F_DUMP flag set. Every neighbour table configuration is
 * spread over multiple messages to avoid running into message
 * size limits on systems with many interfaces. The first message
 * in the sequence transports all not device specific data such as
 * statistics, configuration, and the default parameter set.
 * This message is followed by 0..n messages carrying device
 * specific parameter sets.
 * Although the ordering should be sufficient, NDTA_NAME can be
 * used to identify sequences. The initial message can be identified
 * by checking for NDTA_CONFIG. The device specific messages do
 * not contain this TLV but have NDTPA_IFINDEX set to the
 * corresponding interface index.
 *
 * To change neighbour table attributes, send RTM_SETNEIGHTBL
 * with NDTA_NAME set. Changeable attribute include NDTA_THRESH[1-3],
 * NDTA_GC_INTERVAL, and all TLVs in NDTA_PARMS unless marked
 * otherwise. Device specific parameter sets can be changed by
 * setting NDTPA_IFINDEX to the interface index of the corresponding
 * device.
 ****/

struct ndt_stats {
	__u64		ndts_allocs;
	__u64		ndts_destroys;
	__u64		ndts_hash_grows;
	__u64		ndts_res_failed;
	__u64		ndts_lookups;
	__u64		ndts_hits;
	__u64		ndts_rcv_probes_mcast;
	__u64		ndts_rcv_probes_ucast;
	__u64		ndts_periodic_gc_runs;
	__u64		ndts_forced_gc_runs;
	__u64		ndts_table_fulls;
};

enum {
	NDTPA_UNSPEC,
	NDTPA_IFINDEX,			/* u32, unchangeable */
	NDTPA_REFCNT,			/* u32, read-only */
	NDTPA_REACHABLE_TIME,		/* u64, read-only, msecs */
	NDTPA_BASE_REACHABLE_TIME,	/* u64, msecs */
	NDTPA_RETRANS_TIME,		/* u64, msecs */
	NDTPA_GC_STALETIME,		/* u64, msecs */
	NDTPA_DELAY_PROBE_TIME,		/* u64, msecs */
	NDTPA_QUEUE_LEN,		/* u32 */
	NDTPA_APP_PROBES,		/* u32 */
	NDTPA_UCAST_PROBES,		/* u32 */
	NDTPA_MCAST_PROBES,		/* u32 */
	NDTPA_ANYCAST_DELAY,		/* u64, msecs */
	NDTPA_PROXY_DELAY,		/* u64, msecs */
	NDTPA_PROXY_QLEN,		/* u32 */
	NDTPA_LOCKTIME,			/* u64, msecs */
	NDTPA_QUEUE_LENBYTES,		/* u32 */
	NDTPA_MCAST_REPROBES,		/* u32 */
	NDTPA_PAD,
	NDTPA_INTERVAL_PROBE_TIME_MS,	/* u64, msecs */
	__NDTPA_MAX
};
#define NDTPA_MAX (__NDTPA_MAX - 1)

struct ndtmsg {
	__u8		ndtm_family;
	__u8		ndtm_pad1;
	__u16		ndtm_pad2;
};

struct ndt_config {
	__u16		ndtc_key_len;
	__u16		ndtc_entry_size;
	__u32		ndtc_entries;
	__u32		ndtc_last_flush;	/* delta to now in msecs */
	__u32		ndtc_last_rand;		/* delta to now in msecs */
	__u32		ndtc_hash_rnd;
	__u32		ndtc_hash_mask;
	__u32		ndtc_hash_chain_gc;
	__u32		ndtc_proxy_qlen;
};

enum {
	NDTA_UNSPEC,
	NDTA_NAME,			/* char *, unchangeable */
	NDTA_THRESH1,			/* u32 */
	NDTA_THRESH2,			/* u32 */
	NDTA_THRESH3,			/* u32 */
	NDTA_CONFIG,			/* struct ndt_config, read-only */
	NDTA_PARMS,			/* nested TLV NDTPA_* */
	NDTA_STATS,			/* struct ndt_stats, read-only */
	NDTA_GC_INTERVAL,		/* u64, msecs */
	NDTA_PAD,
	__NDTA_MAX
};
#define NDTA_MAX (__NDTA_MAX - 1)

 /* FDB activity notification bits used in NFEA_ACTIVITY_NOTIFY:
  * - FDB_NOTIFY_BIT - notify on activity/expire for any entry
  * - FDB_NOTIFY_INACTIVE_BIT - mark as inactive to avoid multiple notifications
  */
enum {
	FDB_NOTIFY_BIT		= (1 << 0),
	FDB_NOTIFY_INACTIVE_BIT	= (1 << 1)
};

/* embedded into NDA_FDB_EXT_ATTRS:
 * [NDA_FDB_EXT_ATTRS] = {
 *     [NFEA_ACTIVITY_NOTIFY]
 *     ...
 * }
 */
enum {
	NFEA_UNSPEC,
	NFEA_ACTIVITY_NOTIFY,
	NFEA_DONT_REFRESH,
	__NFEA_MAX
};
#define NFEA_MAX (__NFEA_MAX - 1)

#endif