[mirror_ubuntu-hirsute-kernel.git] / include / net / neighbour.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NET_NEIGHBOUR_H
#define _NET_NEIGHBOUR_H

#include <linux/neighbour.h>

/*
 *	Generic neighbour manipulation
 *
 *	Authors:
 *	Pedro Roque		<roque@di.fc.ul.pt>
 *	Alexey Kuznetsov	<kuznet@ms2.inr.ac.ru>
 *
 * 	Changes:
 *
 *	Harald Welte:		<laforge@gnumonks.org>
 *		- Add neighbour cache statistics like rtstat
 */

#include <linux/atomic.h>
#include <linux/refcount.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/rcupdate.h>
#include <linux/seq_file.h>
#include <linux/bitmap.h>

#include <linux/err.h>
#include <linux/sysctl.h>
#include <linux/workqueue.h>
#include <net/rtnetlink.h>

/*
 * NUD stands for "neighbor unreachability detection"
 */

#define NUD_IN_TIMER	(NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
#define NUD_VALID	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
#define NUD_CONNECTED	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)

struct neighbour;

enum {
	NEIGH_VAR_MCAST_PROBES,
	NEIGH_VAR_UCAST_PROBES,
	NEIGH_VAR_APP_PROBES,
	NEIGH_VAR_MCAST_REPROBES,
	NEIGH_VAR_RETRANS_TIME,
	NEIGH_VAR_BASE_REACHABLE_TIME,
	NEIGH_VAR_DELAY_PROBE_TIME,
	NEIGH_VAR_GC_STALETIME,
	NEIGH_VAR_QUEUE_LEN_BYTES,
	NEIGH_VAR_PROXY_QLEN,
	NEIGH_VAR_ANYCAST_DELAY,
	NEIGH_VAR_PROXY_DELAY,
	NEIGH_VAR_LOCKTIME,
#define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1)
	/* Following are used as a second way to access one of the above */
	NEIGH_VAR_QUEUE_LEN, /* same data as NEIGH_VAR_QUEUE_LEN_BYTES */
	NEIGH_VAR_RETRANS_TIME_MS, /* same data as NEIGH_VAR_RETRANS_TIME */
	NEIGH_VAR_BASE_REACHABLE_TIME_MS, /* same data as NEIGH_VAR_BASE_REACHABLE_TIME */
	/* Following are used by "default" only */
	NEIGH_VAR_GC_INTERVAL,
	NEIGH_VAR_GC_THRESH1,
	NEIGH_VAR_GC_THRESH2,
	NEIGH_VAR_GC_THRESH3,
	NEIGH_VAR_MAX
};

struct neigh_parms {
	possible_net_t net;
	struct net_device *dev;
	struct list_head list;
	int	(*neigh_setup)(struct neighbour *);
	struct neigh_table *tbl;

	void	*sysctl_table;

	int dead;
	refcount_t refcnt;
	struct rcu_head rcu_head;

	int	reachable_time;
	int	data[NEIGH_VAR_DATA_MAX];
	DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX);
};

static inline void neigh_var_set(struct neigh_parms *p, int index, int val)
{
	set_bit(index, p->data_state);
	p->data[index] = val;
}

#define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr])

/* In ndo_neigh_setup, NEIGH_VAR_INIT should be used.
 * In other cases, NEIGH_VAR_SET should be used.
 */
#define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val)
#define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val)

static inline void neigh_parms_data_state_setall(struct neigh_parms *p)
{
	bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX);
}

static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p)
{
	bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX);
}

struct neigh_statistics {
	unsigned long allocs;		/* number of allocated neighs */
	unsigned long destroys;		/* number of destroyed neighs */
	unsigned long hash_grows;	/* number of hash resizes */

	unsigned long res_failed;	/* number of failed resolutions */

	unsigned long lookups;		/* number of lookups */
	unsigned long hits;		/* number of hits (among lookups) */

	unsigned long rcv_probes_mcast;	/* number of received mcast ipv6 */
	unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */

	unsigned long periodic_gc_runs;	/* number of periodic GC runs */
	unsigned long forced_gc_runs;	/* number of forced GC runs */

	unsigned long unres_discards;	/* number of unresolved drops */
	unsigned long table_fulls;      /* times even gc couldn't help */
};

#define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)

struct neighbour {
	struct neighbour __rcu	*next;
	struct neigh_table	*tbl;
	struct neigh_parms	*parms;
	unsigned long		confirmed;
	unsigned long		updated;
	rwlock_t		lock;
	refcount_t		refcnt;
	unsigned int		arp_queue_len_bytes;
	struct sk_buff_head	arp_queue;
	struct timer_list	timer;
	unsigned long		used;
	atomic_t		probes;
	__u8			flags;
	__u8			nud_state;
	__u8			type;
	__u8			dead;
	u8			protocol;
	seqlock_t		ha_lock;
	unsigned char		ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))] __aligned(8);
	struct hh_cache		hh;
	int			(*output)(struct neighbour *, struct sk_buff *);
	const struct neigh_ops	*ops;
	struct list_head	gc_list;
	struct rcu_head		rcu;
	struct net_device	*dev;
	u8			primary_key[0];
} __randomize_layout;

struct neigh_ops {
	int			family;
	void			(*solicit)(struct neighbour *, struct sk_buff *);
	void			(*error_report)(struct neighbour *, struct sk_buff *);
	int			(*output)(struct neighbour *, struct sk_buff *);
	int			(*connected_output)(struct neighbour *, struct sk_buff *);
};

struct pneigh_entry {
	struct pneigh_entry	*next;
	possible_net_t		net;
	struct net_device	*dev;
	u8			flags;
	u8			protocol;
	u8			key[];
};

/*
 *	neighbour table manipulation
 */

#define NEIGH_NUM_HASH_RND	4

struct neigh_hash_table {
	struct neighbour __rcu	**hash_buckets;
	unsigned int		hash_shift;
	__u32			hash_rnd[NEIGH_NUM_HASH_RND];
	struct rcu_head		rcu;
};


struct neigh_table {
	int			family;
	unsigned int		entry_size;
	unsigned int		key_len;
	__be16			protocol;
	__u32			(*hash)(const void *pkey,
					const struct net_device *dev,
					__u32 *hash_rnd);
	bool			(*key_eq)(const struct neighbour *, const void *pkey);
	int			(*constructor)(struct neighbour *);
	int			(*pconstructor)(struct pneigh_entry *);
	void			(*pdestructor)(struct pneigh_entry *);
	void			(*proxy_redo)(struct sk_buff *skb);
	bool			(*allow_add)(const struct net_device *dev,
					     struct netlink_ext_ack *extack);
	char			*id;
	struct neigh_parms	parms;
	struct list_head	parms_list;
	int			gc_interval;
	int			gc_thresh1;
	int			gc_thresh2;
	int			gc_thresh3;
	unsigned long		last_flush;
	struct delayed_work	gc_work;
	struct timer_list 	proxy_timer;
	struct sk_buff_head	proxy_queue;
	atomic_t		entries;
	atomic_t		gc_entries;
	struct list_head	gc_list;
	rwlock_t		lock;
	unsigned long		last_rand;
	struct neigh_statistics	__percpu *stats;
	struct neigh_hash_table __rcu *nht;
	struct pneigh_entry	**phash_buckets;
};

enum {
	NEIGH_ARP_TABLE = 0,
	NEIGH_ND_TABLE = 1,
	NEIGH_DN_TABLE = 2,
	NEIGH_NR_TABLES,
	NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
};

static inline int neigh_parms_family(struct neigh_parms *p)
{
	return p->tbl->family;
}

#define NEIGH_PRIV_ALIGN	sizeof(long long)
#define NEIGH_ENTRY_SIZE(size)	ALIGN((size), NEIGH_PRIV_ALIGN)

static inline void *neighbour_priv(const struct neighbour *n)
{
	return (char *)n + n->tbl->entry_size;
}

/* flags for neigh_update() */
#define NEIGH_UPDATE_F_OVERRIDE			0x00000001
#define NEIGH_UPDATE_F_WEAK_OVERRIDE		0x00000002
#define NEIGH_UPDATE_F_OVERRIDE_ISROUTER	0x00000004
#define NEIGH_UPDATE_F_EXT_LEARNED		0x20000000
#define NEIGH_UPDATE_F_ISROUTER			0x40000000
#define NEIGH_UPDATE_F_ADMIN			0x80000000

extern const struct nla_policy nda_policy[];

static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey)
{
	return *(const u16 *)n->primary_key == *(const u16 *)pkey;
}

static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey)
{
	return *(const u32 *)n->primary_key == *(const u32 *)pkey;
}

static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey)
{
	const u32 *n32 = (const u32 *)n->primary_key;
	const u32 *p32 = pkey;

	return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
		(n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0;
}

static inline struct neighbour *___neigh_lookup_noref(
	struct neigh_table *tbl,
	bool (*key_eq)(const struct neighbour *n, const void *pkey),
	__u32 (*hash)(const void *pkey,
		      const struct net_device *dev,
		      __u32 *hash_rnd),
	const void *pkey,
	struct net_device *dev)
{
	struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht);
	struct neighbour *n;
	u32 hash_val;

	hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
	     n != NULL;
	     n = rcu_dereference_bh(n->next)) {
		if (n->dev == dev && key_eq(n, pkey))
			return n;
	}

	return NULL;
}

static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl,
						     const void *pkey,
						     struct net_device *dev)
{
	return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
}

void neigh_table_init(int index, struct neigh_table *tbl);
int neigh_table_clear(int index, struct neigh_table *tbl);
struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
			       struct net_device *dev);
struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
				     const void *pkey);
struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
				 struct net_device *dev, bool want_ref);
static inline struct neighbour *neigh_create(struct neigh_table *tbl,
					     const void *pkey,
					     struct net_device *dev)
{
	return __neigh_create(tbl, pkey, dev, true);
}
void neigh_destroy(struct neighbour *neigh);
int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
		 u32 nlmsg_pid);
void __neigh_set_probe_once(struct neighbour *neigh);
bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev);
int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
struct neighbour *neigh_event_ns(struct neigh_table *tbl,
						u8 *lladdr, void *saddr,
						struct net_device *dev);

struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
				      struct neigh_table *tbl);
void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);

static inline
struct net *neigh_parms_net(const struct neigh_parms *parms)
{
	return read_pnet(&parms->net);
}

unsigned long neigh_rand_reach_time(unsigned long base);

void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
		    struct sk_buff *skb);
struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
				   const void *key, struct net_device *dev,
				   int creat);
struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
				     const void *key, struct net_device *dev);
int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
		  struct net_device *dev);

static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
{
	return read_pnet(&pneigh->net);
}

void neigh_app_ns(struct neighbour *n);
void neigh_for_each(struct neigh_table *tbl,
		    void (*cb)(struct neighbour *, void *), void *cookie);
void __neigh_for_each_release(struct neigh_table *tbl,
			      int (*cb)(struct neighbour *));
int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *);
void pneigh_for_each(struct neigh_table *tbl,
		     void (*cb)(struct pneigh_entry *));

struct neigh_seq_state {
	struct seq_net_private p;
	struct neigh_table *tbl;
	struct neigh_hash_table *nht;
	void *(*neigh_sub_iter)(struct neigh_seq_state *state,
				struct neighbour *n, loff_t *pos);
	unsigned int bucket;
	unsigned int flags;
#define NEIGH_SEQ_NEIGH_ONLY	0x00000001
#define NEIGH_SEQ_IS_PNEIGH	0x00000002
#define NEIGH_SEQ_SKIP_NOARP	0x00000004
};
void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
		      unsigned int);
void *neigh_seq_next(struct seq_file *, void *, loff_t *);
void neigh_seq_stop(struct seq_file *, void *);

int neigh_proc_dointvec(struct ctl_table *ctl, int write,
			void *buffer, size_t *lenp, loff_t *ppos);
int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
				void *buffer,
				size_t *lenp, loff_t *ppos);
int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
				   void *buffer, size_t *lenp, loff_t *ppos);

int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
			  proc_handler *proc_handler);
void neigh_sysctl_unregister(struct neigh_parms *p);

static inline void __neigh_parms_put(struct neigh_parms *parms)
{
	refcount_dec(&parms->refcnt);
}

static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
{
	refcount_inc(&parms->refcnt);
	return parms;
}

/*
 *	Neighbour references
 */

static inline void neigh_release(struct neighbour *neigh)
{
	if (refcount_dec_and_test(&neigh->refcnt))
		neigh_destroy(neigh);
}

static inline struct neighbour * neigh_clone(struct neighbour *neigh)
{
	if (neigh)
		refcount_inc(&neigh->refcnt);
	return neigh;
}

#define neigh_hold(n)	refcount_inc(&(n)->refcnt)

static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
{
	unsigned long now = jiffies;
	
	if (READ_ONCE(neigh->used) != now)
		WRITE_ONCE(neigh->used, now);
	if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
		return __neigh_event_send(neigh, skb);
	return 0;
}

#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
{
	unsigned int seq, hh_alen;

	do {
		seq = read_seqbegin(&hh->hh_lock);
		hh_alen = HH_DATA_ALIGN(ETH_HLEN);
		memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
	} while (read_seqretry(&hh->hh_lock, seq));
	return 0;
}
#endif

static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
{
	unsigned int hh_alen = 0;
	unsigned int seq;
	unsigned int hh_len;

	do {
		seq = read_seqbegin(&hh->hh_lock);
		hh_len = READ_ONCE(hh->hh_len);
		if (likely(hh_len <= HH_DATA_MOD)) {
			hh_alen = HH_DATA_MOD;

			/* skb_push() would proceed silently if we have room for
			 * the unaligned size but not for the aligned size:
			 * check headroom explicitly.
			 */
			if (likely(skb_headroom(skb) >= HH_DATA_MOD)) {
				/* this is inlined by gcc */
				memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
				       HH_DATA_MOD);
			}
		} else {
			hh_alen = HH_DATA_ALIGN(hh_len);

			if (likely(skb_headroom(skb) >= hh_alen)) {
				memcpy(skb->data - hh_alen, hh->hh_data,
				       hh_alen);
			}
		}
	} while (read_seqretry(&hh->hh_lock, seq));

	if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) {
		kfree_skb(skb);
		return NET_XMIT_DROP;
	}

	__skb_push(skb, hh_len);
	return dev_queue_xmit(skb);
}

static inline int neigh_output(struct neighbour *n, struct sk_buff *skb,
			       bool skip_cache)
{
	const struct hh_cache *hh = &n->hh;

	if ((n->nud_state & NUD_CONNECTED) && hh->hh_len && !skip_cache)
		return neigh_hh_output(hh, skb);
	else
		return n->output(n, skb);
}

static inline struct neighbour *
__neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
{
	struct neighbour *n = neigh_lookup(tbl, pkey, dev);

	if (n || !creat)
		return n;

	n = neigh_create(tbl, pkey, dev);
	return IS_ERR(n) ? NULL : n;
}

static inline struct neighbour *
__neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
  struct net_device *dev)
{
	struct neighbour *n = neigh_lookup(tbl, pkey, dev);

	if (n)
		return n;

	return neigh_create(tbl, pkey, dev);
}

struct neighbour_cb {
	unsigned long sched_next;
	unsigned int flags;
};

#define LOCALLY_ENQUEUED 0x1

#define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)

static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
				     const struct net_device *dev)
{
	unsigned int seq;

	do {
		seq = read_seqbegin(&n->ha_lock);
		memcpy(dst, n->ha, dev->addr_len);
	} while (read_seqretry(&n->ha_lock, seq));
}

static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags,
					  int *notify)
{
	u8 ndm_flags = 0;

	ndm_flags |= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0;
	if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) {
		if (ndm_flags & NTF_ROUTER)
			neigh->flags |= NTF_ROUTER;
		else
			neigh->flags &= ~NTF_ROUTER;
		*notify = 1;
	}
}
#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	#ifndef _NET_NEIGHBOUR_H
	3	#define _NET_NEIGHBOUR_H
	4
9067c722 TG	5	#include <linux/neighbour.h>
9067c722 TG	6
1da177e4 LT	7	/*
	8	* Generic neighbour manipulation
	9	*
	10	* Authors:
	11	* Pedro Roque <roque@di.fc.ul.pt>
	12	* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
	13	*
	14	* Changes:
	15	*
	16	* Harald Welte: <laforge@gnumonks.org>
	17	* - Add neighbour cache statistics like rtstat
	18	*/
	19
60063497	20	#include <linux/atomic.h>
9f237430	21	#include <linux/refcount.h>
1da177e4	22	#include <linux/netdevice.h>
14c85021	23	#include <linux/skbuff.h>
1da177e4 LT	24	#include <linux/rcupdate.h>
1da177e4 LT	25	#include <linux/seq_file.h>
1d4c8c29	26	#include <linux/bitmap.h>
1da177e4 LT	27
	28	#include <linux/err.h>
	29	#include <linux/sysctl.h>
e4c4e448	30	#include <linux/workqueue.h>
c8822a4e	31	#include <net/rtnetlink.h>
1da177e4	32
39971554 PE	33	/*
	34	* NUD stands for "neighbor unreachability detection"
	35	*/
	36
1da177e4 LT	37	#define NUD_IN_TIMER (NUD_INCOMPLETE\|NUD_REACHABLE\|NUD_DELAY\|NUD_PROBE)
	38	#define NUD_VALID (NUD_PERMANENT\|NUD_NOARP\|NUD_REACHABLE\|NUD_PROBE\|NUD_STALE\|NUD_DELAY)
	39	#define NUD_CONNECTED (NUD_PERMANENT\|NUD_NOARP\|NUD_REACHABLE)
	40
	41	struct neighbour;
	42
1f9248e5 JP	43	enum {
	44	NEIGH_VAR_MCAST_PROBES,
	45	NEIGH_VAR_UCAST_PROBES,
	46	NEIGH_VAR_APP_PROBES,
8da86466	47	NEIGH_VAR_MCAST_REPROBES,
1f9248e5 JP	48	NEIGH_VAR_RETRANS_TIME,
	49	NEIGH_VAR_BASE_REACHABLE_TIME,
	50	NEIGH_VAR_DELAY_PROBE_TIME,
	51	NEIGH_VAR_GC_STALETIME,
	52	NEIGH_VAR_QUEUE_LEN_BYTES,
	53	NEIGH_VAR_PROXY_QLEN,
	54	NEIGH_VAR_ANYCAST_DELAY,
	55	NEIGH_VAR_PROXY_DELAY,
	56	NEIGH_VAR_LOCKTIME,
	57	#define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1)
	58	/* Following are used as a second way to access one of the above */
	59	NEIGH_VAR_QUEUE_LEN, /* same data as NEIGH_VAR_QUEUE_LEN_BYTES */
	60	NEIGH_VAR_RETRANS_TIME_MS, /* same data as NEIGH_VAR_RETRANS_TIME */
	61	NEIGH_VAR_BASE_REACHABLE_TIME_MS, /* same data as NEIGH_VAR_BASE_REACHABLE_TIME */
	62	/* Following are used by "default" only */
	63	NEIGH_VAR_GC_INTERVAL,
	64	NEIGH_VAR_GC_THRESH1,
	65	NEIGH_VAR_GC_THRESH2,
	66	NEIGH_VAR_GC_THRESH3,
	67	NEIGH_VAR_MAX
	68	};
	69
fd2c3ef7	70	struct neigh_parms {
0c5c9fb5	71	possible_net_t net;
c7fb64db	72	struct net_device *dev;
75fbfd33	73	struct list_head list;
447f2191	74	int (neigh_setup)(struct neighbour );
1da177e4	75	struct neigh_table *tbl;
1da177e4 LT	76
	77	void *sysctl_table;
	78
	79	int dead;
6343944b	80	refcount_t refcnt;
1da177e4 LT	81	struct rcu_head rcu_head;
1da177e4 LT	82
1da177e4	83	int reachable_time;
1f9248e5	84	int data[NEIGH_VAR_DATA_MAX];
1d4c8c29	85	DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX);
1da177e4 LT	86	};
1da177e4 LT	87
1f9248e5 JP	88	static inline void neigh_var_set(struct neigh_parms *p, int index, int val)
1f9248e5 JP	89	{
1d4c8c29	90	set_bit(index, p->data_state);
1f9248e5 JP	91	p->data[index] = val;
	92	}
	93
	94	#define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr])
89740ca7 JP	95
	96	/* In ndo_neigh_setup, NEIGH_VAR_INIT should be used.
	97	* In other cases, NEIGH_VAR_SET should be used.
	98	*/
	99	#define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val)
1f9248e5 JP	100	#define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val)
1f9248e5 JP	101
1d4c8c29 JP	102	static inline void neigh_parms_data_state_setall(struct neigh_parms *p)
	103	{
	104	bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX);
	105	}
	106
	107	static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p)
	108	{
	109	bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX);
	110	}
	111
fd2c3ef7	112	struct neigh_statistics {
1da177e4 LT	113	unsigned long allocs; /* number of allocated neighs */
	114	unsigned long destroys; /* number of destroyed neighs */
	115	unsigned long hash_grows; /* number of hash resizes */
	116
9a6d276e	117	unsigned long res_failed; /* number of failed resolutions */
1da177e4 LT	118
	119	unsigned long lookups; /* number of lookups */
	120	unsigned long hits; /* number of hits (among lookups) */
	121
	122	unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
	123	unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
	124
	125	unsigned long periodic_gc_runs; /* number of periodic GC runs */
	126	unsigned long forced_gc_runs; /* number of forced GC runs */
9a6d276e NH	127
9a6d276e NH	128	unsigned long unres_discards; /* number of unresolved drops */
fb811395	129	unsigned long table_fulls; /* times even gc couldn't help */
1da177e4 LT	130	};
1da177e4 LT	131
4ea7334b	132	#define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
1da177e4	133
fd2c3ef7	134	struct neighbour {
767e97e1	135	struct neighbour __rcu *next;
1da177e4 LT	136	struct neigh_table *tbl;
1da177e4 LT	137	struct neigh_parms *parms;
1da177e4 LT	138	unsigned long confirmed;
1da177e4 LT	139	unsigned long updated;
46b13fc5	140	rwlock_t lock;
9f237430	141	refcount_t refcnt;
8b5c171b	142	unsigned int arp_queue_len_bytes;
4b7cd11f	143	struct sk_buff_head arp_queue;
e37ef961 ED	144	struct timer_list timer;
e37ef961 ED	145	unsigned long used;
1da177e4	146	atomic_t probes;
46b13fc5 ED	147	__u8 flags;
	148	__u8 nud_state;
	149	__u8 type;
	150	__u8 dead;
df9b0e30	151	u8 protocol;
0ed8ddf4	152	seqlock_t ha_lock;
4b7cd11f	153	unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))] __aligned(8);
f6b72b62	154	struct hh_cache hh;
8f40b161	155	int (output)(struct neighbour , struct sk_buff *);
89d69d2b	156	const struct neigh_ops *ops;
58956317	157	struct list_head gc_list;
767e97e1	158	struct rcu_head rcu;
e37ef961	159	struct net_device *dev;
1da177e4	160	u8 primary_key[0];
3859a271	161	} __randomize_layout;
1da177e4	162
fd2c3ef7	163	struct neigh_ops {
1da177e4	164	int family;
8f40b161 DM	165	void (solicit)(struct neighbour , struct sk_buff *);
	166	void (error_report)(struct neighbour , struct sk_buff *);
	167	int (output)(struct neighbour , struct sk_buff *);
	168	int (connected_output)(struct neighbour , struct sk_buff *);
1da177e4 LT	169	};
1da177e4 LT	170
fd2c3ef7	171	struct pneigh_entry {
1da177e4	172	struct pneigh_entry *next;
0c5c9fb5	173	possible_net_t net;
426b5303	174	struct net_device *dev;
62dd9318	175	u8 flags;
df9b0e30	176	u8 protocol;
08ca27d0	177	u8 key[];
1da177e4 LT	178	};
	179
	180	/*
	181	* neighbour table manipulation
	182	*/
	183
2c2aba6c DM	184	#define NEIGH_NUM_HASH_RND 4
2c2aba6c DM	185
d6bf7817	186	struct neigh_hash_table {
767e97e1	187	struct neighbour __rcu **hash_buckets;
cd089336	188	unsigned int hash_shift;
2c2aba6c	189	__u32 hash_rnd[NEIGH_NUM_HASH_RND];
d6bf7817 ED	190	struct rcu_head rcu;
	191	};
	192
1da177e4	193
fd2c3ef7	194	struct neigh_table {
1da177e4	195	int family;
e451ae8e	196	unsigned int entry_size;
01ccdf12	197	unsigned int key_len;
bdf53c58	198	__be16 protocol;
d6bf7817 ED	199	__u32 (hash)(const void pkey,
d6bf7817 ED	200	const struct net_device *dev,
2c2aba6c	201	__u32 *hash_rnd);
60395a20	202	bool (key_eq)(const struct neighbour , const void *pkey);
1da177e4 LT	203	int (constructor)(struct neighbour );
	204	int (pconstructor)(struct pneigh_entry );
	205	void (pdestructor)(struct pneigh_entry );
	206	void (proxy_redo)(struct sk_buff skb);
b8fb1ab4 DA	207	bool (allow_add)(const struct net_device dev,
b8fb1ab4 DA	208	struct netlink_ext_ack *extack);
1da177e4 LT	209	char *id;
1da177e4 LT	210	struct neigh_parms parms;
75fbfd33	211	struct list_head parms_list;
1da177e4 LT	212	int gc_interval;
	213	int gc_thresh1;
	214	int gc_thresh2;
	215	int gc_thresh3;
	216	unsigned long last_flush;
e4c4e448	217	struct delayed_work gc_work;
1da177e4 LT	218	struct timer_list proxy_timer;
	219	struct sk_buff_head proxy_queue;
	220	atomic_t entries;
58956317 DA	221	atomic_t gc_entries;
58956317 DA	222	struct list_head gc_list;
1da177e4 LT	223	rwlock_t lock;
1da177e4 LT	224	unsigned long last_rand;
7d720c3e	225	struct neigh_statistics __percpu *stats;
d6bf7817	226	struct neigh_hash_table __rcu *nht;
1da177e4	227	struct pneigh_entry **phash_buckets;
1da177e4 LT	228	};
1da177e4 LT	229
d7480fd3 WC	230	enum {
	231	NEIGH_ARP_TABLE = 0,
	232	NEIGH_ND_TABLE = 1,
	233	NEIGH_DN_TABLE = 2,
	234	NEIGH_NR_TABLES,
b79bda3d	235	NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
d7480fd3 WC	236	};
d7480fd3 WC	237
73af614a JP	238	static inline int neigh_parms_family(struct neigh_parms *p)
	239	{
	240	return p->tbl->family;
	241	}
	242
1026fec8	243	#define NEIGH_PRIV_ALIGN sizeof(long long)
daaba4fa	244	#define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN)
1026fec8 DM	245
	246	static inline void neighbour_priv(const struct neighbour n)
	247	{
08433eff	248	return (char *)n + n->tbl->entry_size;
1026fec8 DM	249	}
1026fec8 DM	250
1da177e4 LT	251	/* flags for neigh_update() */
	252	#define NEIGH_UPDATE_F_OVERRIDE 0x00000001
	253	#define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002
	254	#define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004
9ce33e46	255	#define NEIGH_UPDATE_F_EXT_LEARNED 0x20000000
1da177e4 LT	256	#define NEIGH_UPDATE_F_ISROUTER 0x40000000
	257	#define NEIGH_UPDATE_F_ADMIN 0x80000000
	258
82cbb5c6	259	extern const struct nla_policy nda_policy[];
60395a20 EB	260
	261	static inline bool neigh_key_eq16(const struct neighbour n, const void pkey)
	262	{
	263	return (const u16 )n->primary_key == (const u16 )pkey;
	264	}
	265
	266	static inline bool neigh_key_eq32(const struct neighbour n, const void pkey)
	267	{
	268	return (const u32 )n->primary_key == (const u32 )pkey;
	269	}
	270
	271	static inline bool neigh_key_eq128(const struct neighbour n, const void pkey)
	272	{
	273	const u32 n32 = (const u32 )n->primary_key;
	274	const u32 *p32 = pkey;
	275
	276	return ((n32[0] ^ p32[0]) \| (n32[1] ^ p32[1]) \|
	277	(n32[2] ^ p32[2]) \| (n32[3] ^ p32[3])) == 0;
	278	}
	279
	280	static inline struct neighbour *___neigh_lookup_noref(
	281	struct neigh_table *tbl,
	282	bool (key_eq)(const struct neighbour n, const void *pkey),
	283	__u32 (hash)(const void pkey,
	284	const struct net_device *dev,
	285	__u32 *hash_rnd),
	286	const void *pkey,
	287	struct net_device *dev)
	288	{
	289	struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht);
	290	struct neighbour *n;
	291	u32 hash_val;
	292
	293	hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
	294	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
	295	n != NULL;
	296	n = rcu_dereference_bh(n->next)) {
	297	if (n->dev == dev && key_eq(n, pkey))
	298	return n;
	299	}
	300
	301	return NULL;
	302	}
	303
	304	static inline struct neighbour __neigh_lookup_noref(struct neigh_table tbl,
	305	const void *pkey,
	306	struct net_device *dev)
	307	{
	308	return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
	309	}
	310
d7480fd3 WC	311	void neigh_table_init(int index, struct neigh_table *tbl);
d7480fd3 WC	312	int neigh_table_clear(int index, struct neigh_table *tbl);
90972b22 JP	313	struct neighbour neigh_lookup(struct neigh_table tbl, const void *pkey,
	314	struct net_device *dev);
	315	struct neighbour neigh_lookup_nodev(struct neigh_table tbl, struct net *net,
	316	const void *pkey);
	317	struct neighbour __neigh_create(struct neigh_table tbl, const void *pkey,
	318	struct net_device *dev, bool want_ref);
a263b309	319	static inline struct neighbour neigh_create(struct neigh_table tbl,
1da177e4	320	const void *pkey,
a263b309 DM	321	struct net_device *dev)
	322	{
	323	return __neigh_create(tbl, pkey, dev, true);
	324	}
90972b22 JP	325	void neigh_destroy(struct neighbour *neigh);
90972b22 JP	326	int __neigh_event_send(struct neighbour neigh, struct sk_buff skb);
7b8f7a40 RP	327	int neigh_update(struct neighbour neigh, const u8 lladdr, u8 new, u32 flags,
7b8f7a40 RP	328	u32 nlmsg_pid);
7e980569	329	void __neigh_set_probe_once(struct neighbour *neigh);
5071034e	330	bool neigh_remove_one(struct neighbour ndel, struct neigh_table tbl);
90972b22 JP	331	void neigh_changeaddr(struct neigh_table tbl, struct net_device dev);
90972b22 JP	332	int neigh_ifdown(struct neigh_table tbl, struct net_device dev);
859bd2ef	333	int neigh_carrier_down(struct neigh_table tbl, struct net_device dev);
90972b22 JP	334	int neigh_resolve_output(struct neighbour neigh, struct sk_buff skb);
90972b22 JP	335	int neigh_connected_output(struct neighbour neigh, struct sk_buff skb);
90972b22 JP	336	int neigh_direct_output(struct neighbour neigh, struct sk_buff skb);
90972b22 JP	337	struct neighbour neigh_event_ns(struct neigh_table tbl,
1da177e4 LT	338	u8 lladdr, void saddr,
	339	struct net_device *dev);
	340
90972b22 JP	341	struct neigh_parms neigh_parms_alloc(struct net_device dev,
	342	struct neigh_table *tbl);
	343	void neigh_parms_release(struct neigh_table tbl, struct neigh_parms parms);
57da52c1 YH	344
57da52c1 YH	345	static inline
90972b22	346	struct net neigh_parms_net(const struct neigh_parms parms)
57da52c1	347	{
e42ea986	348	return read_pnet(&parms->net);
57da52c1 YH	349	}
57da52c1 YH	350
90972b22	351	unsigned long neigh_rand_reach_time(unsigned long base);
1da177e4	352
90972b22 JP	353	void pneigh_enqueue(struct neigh_table tbl, struct neigh_parms p,
	354	struct sk_buff *skb);
	355	struct pneigh_entry pneigh_lookup(struct neigh_table tbl, struct net *net,
	356	const void key, struct net_device dev,
	357	int creat);
	358	struct pneigh_entry __pneigh_lookup(struct neigh_table tbl, struct net *net,
	359	const void key, struct net_device dev);
	360	int pneigh_delete(struct neigh_table tbl, struct net net, const void *key,
	361	struct net_device *dev);
1da177e4	362
90972b22	363	static inline struct net pneigh_net(const struct pneigh_entry pneigh)
57da52c1	364	{
e42ea986	365	return read_pnet(&pneigh->net);
57da52c1 YH	366	}
57da52c1 YH	367
90972b22 JP	368	void neigh_app_ns(struct neighbour *n);
	369	void neigh_for_each(struct neigh_table *tbl,
	370	void (cb)(struct neighbour , void ), void cookie);
	371	void __neigh_for_each_release(struct neigh_table *tbl,
	372	int (cb)(struct neighbour ));
4fd3d7d9	373	int neigh_xmit(int fam, struct net_device , const void , struct sk_buff *);
90972b22 JP	374	void pneigh_for_each(struct neigh_table *tbl,
90972b22 JP	375	void (cb)(struct pneigh_entry ));
1da177e4 LT	376
1da177e4 LT	377	struct neigh_seq_state {
42508461	378	struct seq_net_private p;
1da177e4	379	struct neigh_table *tbl;
d6bf7817	380	struct neigh_hash_table *nht;
1da177e4 LT	381	void (neigh_sub_iter)(struct neigh_seq_state *state,
	382	struct neighbour n, loff_t pos);
	383	unsigned int bucket;
	384	unsigned int flags;
	385	#define NEIGH_SEQ_NEIGH_ONLY 0x00000001
	386	#define NEIGH_SEQ_IS_PNEIGH 0x00000002
	387	#define NEIGH_SEQ_SKIP_NOARP 0x00000004
	388	};
90972b22 JP	389	void neigh_seq_start(struct seq_file , loff_t , struct neigh_table ,
	390	unsigned int);
	391	void neigh_seq_next(struct seq_file , void , loff_t );
	392	void neigh_seq_stop(struct seq_file , void );
	393
cb5b09c1	394	int neigh_proc_dointvec(struct ctl_table *ctl, int write,
c7388c1f	395	void buffer, size_t lenp, loff_t *ppos);
cb5b09c1	396	int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
c7388c1f	397	void *buffer,
cb5b09c1 JP	398	size_t lenp, loff_t ppos);
cb5b09c1 JP	399	int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
c7388c1f	400	void buffer, size_t lenp, loff_t *ppos);
cb5b09c1	401
90972b22	402	int neigh_sysctl_register(struct net_device dev, struct neigh_parms p,
73af614a	403	proc_handler *proc_handler);
90972b22	404	void neigh_sysctl_unregister(struct neigh_parms *p);
1da177e4 LT	405
	406	static inline void __neigh_parms_put(struct neigh_parms *parms)
	407	{
6343944b	408	refcount_dec(&parms->refcnt);
1da177e4 LT	409	}
1da177e4 LT	410
1da177e4 LT	411	static inline struct neigh_parms neigh_parms_clone(struct neigh_parms parms)
1da177e4 LT	412	{
6343944b	413	refcount_inc(&parms->refcnt);
1da177e4 LT	414	return parms;
	415	}
	416
	417	/*
	418	* Neighbour references
	419	*/
	420
	421	static inline void neigh_release(struct neighbour *neigh)
	422	{
9f237430	423	if (refcount_dec_and_test(&neigh->refcnt))
1da177e4 LT	424	neigh_destroy(neigh);
	425	}
	426
	427	static inline struct neighbour * neigh_clone(struct neighbour *neigh)
	428	{
	429	if (neigh)
9f237430	430	refcount_inc(&neigh->refcnt);
1da177e4 LT	431	return neigh;
	432	}
	433
9f237430	434	#define neigh_hold(n) refcount_inc(&(n)->refcnt)
1da177e4	435
1da177e4 LT	436	static inline int neigh_event_send(struct neighbour neigh, struct sk_buff skb)
1da177e4 LT	437	{
ef22b7b6	438	unsigned long now = jiffies;
0ed8ddf4	439
1b53d644 ED	440	if (READ_ONCE(neigh->used) != now)
1b53d644 ED	441	WRITE_ONCE(neigh->used, now);
1da177e4 LT	442	if (!(neigh->nud_state&(NUD_CONNECTED\|NUD_DELAY\|NUD_PROBE)))
	443	return __neigh_event_send(neigh, skb);
	444	return 0;
	445	}
	446
34666d46	447	#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
e179e632 BDS	448	static inline int neigh_hh_bridge(struct hh_cache hh, struct sk_buff skb)
e179e632 BDS	449	{
95c96174	450	unsigned int seq, hh_alen;
e179e632 BDS	451
	452	do {
	453	seq = read_seqbegin(&hh->hh_lock);
	454	hh_alen = HH_DATA_ALIGN(ETH_HLEN);
	455	memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
	456	} while (read_seqretry(&hh->hh_lock, seq));
	457	return 0;
	458	}
	459	#endif
	460
425f09ab	461	static inline int neigh_hh_output(const struct hh_cache hh, struct sk_buff skb)
3644f0ce	462	{
e6ac64d4	463	unsigned int hh_alen = 0;
95c96174	464	unsigned int seq;
5b3dc2f3	465	unsigned int hh_len;
3644f0ce SH	466
3644f0ce SH	467	do {
3644f0ce	468	seq = read_seqbegin(&hh->hh_lock);
c305c6ae	469	hh_len = READ_ONCE(hh->hh_len);
425f09ab	470	if (likely(hh_len <= HH_DATA_MOD)) {
e6ac64d4 SB	471	hh_alen = HH_DATA_MOD;
	472
	473	/* skb_push() would proceed silently if we have room for
	474	* the unaligned size but not for the aligned size:
	475	* check headroom explicitly.
	476	*/
	477	if (likely(skb_headroom(skb) >= HH_DATA_MOD)) {
	478	/* this is inlined by gcc */
	479	memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
	480	HH_DATA_MOD);
	481	}
425f09ab	482	} else {
e6ac64d4	483	hh_alen = HH_DATA_ALIGN(hh_len);
425f09ab	484
e6ac64d4 SB	485	if (likely(skb_headroom(skb) >= hh_alen)) {
	486	memcpy(skb->data - hh_alen, hh->hh_data,
	487	hh_alen);
	488	}
425f09ab	489	}
3644f0ce SH	490	} while (read_seqretry(&hh->hh_lock, seq));
3644f0ce SH	491
e6ac64d4 SB	492	if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) {
	493	kfree_skb(skb);
	494	return NET_XMIT_DROP;
	495	}
	496
	497	__skb_push(skb, hh_len);
b23b5455	498	return dev_queue_xmit(skb);
3644f0ce SH	499	}
3644f0ce SH	500
0353f282 DA	501	static inline int neigh_output(struct neighbour n, struct sk_buff skb,
0353f282 DA	502	bool skip_cache)
c16ec185 JA	503	{
	504	const struct hh_cache *hh = &n->hh;
	505
0353f282	506	if ((n->nud_state & NUD_CONNECTED) && hh->hh_len && !skip_cache)
c16ec185 JA	507	return neigh_hh_output(hh, skb);
	508	else
	509	return n->output(n, skb);
	510	}
	511
1da177e4 LT	512	static inline struct neighbour *
	513	__neigh_lookup(struct neigh_table tbl, const void pkey, struct net_device *dev, int creat)
	514	{
	515	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
	516
	517	if (n \|\| !creat)
	518	return n;
	519
	520	n = neigh_create(tbl, pkey, dev);
	521	return IS_ERR(n) ? NULL : n;
	522	}
	523
	524	static inline struct neighbour *
	525	__neigh_lookup_errno(struct neigh_table tbl, const void pkey,
	526	struct net_device *dev)
	527	{
	528	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
	529
	530	if (n)
	531	return n;
	532
	533	return neigh_create(tbl, pkey, dev);
	534	}
	535
a61bbcf2 PM	536	struct neighbour_cb {
	537	unsigned long sched_next;
	538	unsigned int flags;
	539	};
	540
	541	#define LOCALLY_ENQUEUED 0x1
	542
	543	#define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
1da177e4	544
0ed8ddf4 ED	545	static inline void neigh_ha_snapshot(char dst, const struct neighbour n,
	546	const struct net_device *dev)
	547	{
	548	unsigned int seq;
	549
	550	do {
	551	seq = read_seqbegin(&n->ha_lock);
	552	memcpy(dst, n->ha, dev->addr_len);
	553	} while (read_seqretry(&n->ha_lock, seq));
	554	}
4fd3d7d9	555
fc6e8073 RP	556	static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags,
	557	int *notify)
	558	{
	559	u8 ndm_flags = 0;
	560
	561	ndm_flags \|= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0;
	562	if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) {
	563	if (ndm_flags & NTF_ROUTER)
	564	neigh->flags \|= NTF_ROUTER;
	565	else
	566	neigh->flags &= ~NTF_ROUTER;
	567	*notify = 1;
	568	}
	569	}
1da177e4	570	#endif