1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _NET_NEIGHBOUR_H
3 #define _NET_NEIGHBOUR_H
4 
5 #include <linux/neighbour.h>
6 
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 
20 #include <linux/atomic.h>
21 #include <linux/refcount.h>
22 #include <linux/netdevice.h>
23 #include <linux/skbuff.h>
24 #include <linux/rcupdate.h>
25 #include <linux/seq_file.h>
26 #include <linux/bitmap.h>
27 
28 #include <linux/err.h>
29 #include <linux/sysctl.h>
30 #include <linux/workqueue.h>
31 #include <net/rtnetlink.h>
32 
33 /*
34  * NUD stands for "neighbor unreachability detection"
35  */
36 
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 
43 enum {
44 	NEIGH_VAR_MCAST_PROBES,
45 	NEIGH_VAR_UCAST_PROBES,
46 	NEIGH_VAR_APP_PROBES,
47 	NEIGH_VAR_MCAST_REPROBES,
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 
70 struct neigh_parms {
71 	possible_net_t net;
72 	struct net_device *dev;
73 	struct list_head list;
74 	int	(*neigh_setup)(struct neighbour *);
75 	struct neigh_table *tbl;
76 
77 	void	*sysctl_table;
78 
79 	int dead;
80 	refcount_t refcnt;
81 	struct rcu_head rcu_head;
82 
83 	int	reachable_time;
84 	int	data[NEIGH_VAR_DATA_MAX];
85 	DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX);
86 };
87 
neigh_var_set(struct neigh_parms * p,int index,int val)88 static inline void neigh_var_set(struct neigh_parms *p, int index, int val)
89 {
90 	set_bit(index, p->data_state);
91 	p->data[index] = val;
92 }
93 
94 #define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr])
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)
100 #define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val)
101 
neigh_parms_data_state_setall(struct neigh_parms * p)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 
neigh_parms_data_state_cleanall(struct neigh_parms * p)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 
112 struct neigh_statistics {
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 
117 	unsigned long res_failed;	/* number of failed resolutions */
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 */
127 
128 	unsigned long unres_discards;	/* number of unresolved drops */
129 	unsigned long table_fulls;      /* times even gc couldn't help */
130 };
131 
132 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
133 
134 struct neighbour {
135 	struct neighbour __rcu	*next;
136 	struct neigh_table	*tbl;
137 	struct neigh_parms	*parms;
138 	unsigned long		confirmed;
139 	unsigned long		updated;
140 	rwlock_t		lock;
141 	refcount_t		refcnt;
142 	unsigned int		arp_queue_len_bytes;
143 	struct sk_buff_head	arp_queue;
144 	struct timer_list	timer;
145 	unsigned long		used;
146 	atomic_t		probes;
147 	u8			nud_state;
148 	u8			type;
149 	u8			dead;
150 	u8			protocol;
151 	u32			flags;
152 	seqlock_t		ha_lock;
153 	unsigned char		ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))] __aligned(8);
154 	struct hh_cache		hh;
155 	int			(*output)(struct neighbour *, struct sk_buff *);
156 	const struct neigh_ops	*ops;
157 	struct list_head	gc_list;
158 	struct list_head	managed_list;
159 	struct rcu_head		rcu;
160 	struct net_device	*dev;
161 	u8			primary_key[0];
162 } __randomize_layout;
163 
164 struct neigh_ops {
165 	int			family;
166 	void			(*solicit)(struct neighbour *, struct sk_buff *);
167 	void			(*error_report)(struct neighbour *, struct sk_buff *);
168 	int			(*output)(struct neighbour *, struct sk_buff *);
169 	int			(*connected_output)(struct neighbour *, struct sk_buff *);
170 };
171 
172 struct pneigh_entry {
173 	struct pneigh_entry	*next;
174 	possible_net_t		net;
175 	struct net_device	*dev;
176 	u32			flags;
177 	u8			protocol;
178 	u8			key[];
179 };
180 
181 /*
182  *	neighbour table manipulation
183  */
184 
185 #define NEIGH_NUM_HASH_RND	4
186 
187 struct neigh_hash_table {
188 	struct neighbour __rcu	**hash_buckets;
189 	unsigned int		hash_shift;
190 	__u32			hash_rnd[NEIGH_NUM_HASH_RND];
191 	struct rcu_head		rcu;
192 };
193 
194 
195 struct neigh_table {
196 	int			family;
197 	unsigned int		entry_size;
198 	unsigned int		key_len;
199 	__be16			protocol;
200 	__u32			(*hash)(const void *pkey,
201 					const struct net_device *dev,
202 					__u32 *hash_rnd);
203 	bool			(*key_eq)(const struct neighbour *, const void *pkey);
204 	int			(*constructor)(struct neighbour *);
205 	int			(*pconstructor)(struct pneigh_entry *);
206 	void			(*pdestructor)(struct pneigh_entry *);
207 	void			(*proxy_redo)(struct sk_buff *skb);
208 	int			(*is_multicast)(const void *pkey);
209 	bool			(*allow_add)(const struct net_device *dev,
210 					     struct netlink_ext_ack *extack);
211 	char			*id;
212 	struct neigh_parms	parms;
213 	struct list_head	parms_list;
214 	int			gc_interval;
215 	int			gc_thresh1;
216 	int			gc_thresh2;
217 	int			gc_thresh3;
218 	unsigned long		last_flush;
219 	struct delayed_work	gc_work;
220 	struct delayed_work	managed_work;
221 	struct timer_list 	proxy_timer;
222 	struct sk_buff_head	proxy_queue;
223 	atomic_t		entries;
224 	atomic_t		gc_entries;
225 	struct list_head	gc_list;
226 	struct list_head	managed_list;
227 	rwlock_t		lock;
228 	unsigned long		last_rand;
229 	struct neigh_statistics	__percpu *stats;
230 	struct neigh_hash_table __rcu *nht;
231 	struct pneigh_entry	**phash_buckets;
232 };
233 
234 enum {
235 	NEIGH_ARP_TABLE = 0,
236 	NEIGH_ND_TABLE = 1,
237 	NEIGH_DN_TABLE = 2,
238 	NEIGH_NR_TABLES,
239 	NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
240 };
241 
neigh_parms_family(struct neigh_parms * p)242 static inline int neigh_parms_family(struct neigh_parms *p)
243 {
244 	return p->tbl->family;
245 }
246 
247 #define NEIGH_PRIV_ALIGN	sizeof(long long)
248 #define NEIGH_ENTRY_SIZE(size)	ALIGN((size), NEIGH_PRIV_ALIGN)
249 
neighbour_priv(const struct neighbour * n)250 static inline void *neighbour_priv(const struct neighbour *n)
251 {
252 	return (char *)n + n->tbl->entry_size;
253 }
254 
255 /* flags for neigh_update() */
256 #define NEIGH_UPDATE_F_OVERRIDE			BIT(0)
257 #define NEIGH_UPDATE_F_WEAK_OVERRIDE		BIT(1)
258 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER	BIT(2)
259 #define NEIGH_UPDATE_F_USE			BIT(3)
260 #define NEIGH_UPDATE_F_MANAGED			BIT(4)
261 #define NEIGH_UPDATE_F_EXT_LEARNED		BIT(5)
262 #define NEIGH_UPDATE_F_ISROUTER			BIT(6)
263 #define NEIGH_UPDATE_F_ADMIN			BIT(7)
264 
265 /* In-kernel representation for NDA_FLAGS_EXT flags: */
266 #define NTF_OLD_MASK		0xff
267 #define NTF_EXT_SHIFT		8
268 #define NTF_EXT_MASK		(NTF_EXT_MANAGED)
269 
270 #define NTF_MANAGED		(NTF_EXT_MANAGED << NTF_EXT_SHIFT)
271 
272 extern const struct nla_policy nda_policy[];
273 
neigh_key_eq16(const struct neighbour * n,const void * pkey)274 static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey)
275 {
276 	return *(const u16 *)n->primary_key == *(const u16 *)pkey;
277 }
278 
neigh_key_eq32(const struct neighbour * n,const void * pkey)279 static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey)
280 {
281 	return *(const u32 *)n->primary_key == *(const u32 *)pkey;
282 }
283 
neigh_key_eq128(const struct neighbour * n,const void * pkey)284 static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey)
285 {
286 	const u32 *n32 = (const u32 *)n->primary_key;
287 	const u32 *p32 = pkey;
288 
289 	return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
290 		(n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0;
291 }
292 
___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)293 static inline struct neighbour *___neigh_lookup_noref(
294 	struct neigh_table *tbl,
295 	bool (*key_eq)(const struct neighbour *n, const void *pkey),
296 	__u32 (*hash)(const void *pkey,
297 		      const struct net_device *dev,
298 		      __u32 *hash_rnd),
299 	const void *pkey,
300 	struct net_device *dev)
301 {
302 	struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht);
303 	struct neighbour *n;
304 	u32 hash_val;
305 
306 	hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
307 	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
308 	     n != NULL;
309 	     n = rcu_dereference_bh(n->next)) {
310 		if (n->dev == dev && key_eq(n, pkey))
311 			return n;
312 	}
313 
314 	return NULL;
315 }
316 
__neigh_lookup_noref(struct neigh_table * tbl,const void * pkey,struct net_device * dev)317 static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl,
318 						     const void *pkey,
319 						     struct net_device *dev)
320 {
321 	return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
322 }
323 
324 void neigh_table_init(int index, struct neigh_table *tbl);
325 int neigh_table_clear(int index, struct neigh_table *tbl);
326 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
327 			       struct net_device *dev);
328 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
329 				     const void *pkey);
330 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
331 				 struct net_device *dev, bool want_ref);
neigh_create(struct neigh_table * tbl,const void * pkey,struct net_device * dev)332 static inline struct neighbour *neigh_create(struct neigh_table *tbl,
333 					     const void *pkey,
334 					     struct net_device *dev)
335 {
336 	return __neigh_create(tbl, pkey, dev, true);
337 }
338 void neigh_destroy(struct neighbour *neigh);
339 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
340 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
341 		 u32 nlmsg_pid);
342 void __neigh_set_probe_once(struct neighbour *neigh);
343 bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
344 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
345 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
346 int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev);
347 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
348 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
349 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
350 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
351 						u8 *lladdr, void *saddr,
352 						struct net_device *dev);
353 
354 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
355 				      struct neigh_table *tbl);
356 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
357 
358 static inline
neigh_parms_net(const struct neigh_parms * parms)359 struct net *neigh_parms_net(const struct neigh_parms *parms)
360 {
361 	return read_pnet(&parms->net);
362 }
363 
364 unsigned long neigh_rand_reach_time(unsigned long base);
365 
366 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
367 		    struct sk_buff *skb);
368 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
369 				   const void *key, struct net_device *dev,
370 				   int creat);
371 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
372 				     const void *key, struct net_device *dev);
373 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
374 		  struct net_device *dev);
375 
pneigh_net(const struct pneigh_entry * pneigh)376 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
377 {
378 	return read_pnet(&pneigh->net);
379 }
380 
381 void neigh_app_ns(struct neighbour *n);
382 void neigh_for_each(struct neigh_table *tbl,
383 		    void (*cb)(struct neighbour *, void *), void *cookie);
384 void __neigh_for_each_release(struct neigh_table *tbl,
385 			      int (*cb)(struct neighbour *));
386 int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *);
387 void pneigh_for_each(struct neigh_table *tbl,
388 		     void (*cb)(struct pneigh_entry *));
389 
390 struct neigh_seq_state {
391 	struct seq_net_private p;
392 	struct neigh_table *tbl;
393 	struct neigh_hash_table *nht;
394 	void *(*neigh_sub_iter)(struct neigh_seq_state *state,
395 				struct neighbour *n, loff_t *pos);
396 	unsigned int bucket;
397 	unsigned int flags;
398 #define NEIGH_SEQ_NEIGH_ONLY	0x00000001
399 #define NEIGH_SEQ_IS_PNEIGH	0x00000002
400 #define NEIGH_SEQ_SKIP_NOARP	0x00000004
401 };
402 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
403 		      unsigned int);
404 void *neigh_seq_next(struct seq_file *, void *, loff_t *);
405 void neigh_seq_stop(struct seq_file *, void *);
406 
407 int neigh_proc_dointvec(struct ctl_table *ctl, int write,
408 			void *buffer, size_t *lenp, loff_t *ppos);
409 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
410 				void *buffer,
411 				size_t *lenp, loff_t *ppos);
412 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
413 				   void *buffer, size_t *lenp, loff_t *ppos);
414 
415 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
416 			  proc_handler *proc_handler);
417 void neigh_sysctl_unregister(struct neigh_parms *p);
418 
__neigh_parms_put(struct neigh_parms * parms)419 static inline void __neigh_parms_put(struct neigh_parms *parms)
420 {
421 	refcount_dec(&parms->refcnt);
422 }
423 
neigh_parms_clone(struct neigh_parms * parms)424 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
425 {
426 	refcount_inc(&parms->refcnt);
427 	return parms;
428 }
429 
430 /*
431  *	Neighbour references
432  */
433 
neigh_release(struct neighbour * neigh)434 static inline void neigh_release(struct neighbour *neigh)
435 {
436 	if (refcount_dec_and_test(&neigh->refcnt))
437 		neigh_destroy(neigh);
438 }
439 
neigh_clone(struct neighbour * neigh)440 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
441 {
442 	if (neigh)
443 		refcount_inc(&neigh->refcnt);
444 	return neigh;
445 }
446 
447 #define neigh_hold(n)	refcount_inc(&(n)->refcnt)
448 
neigh_event_send(struct neighbour * neigh,struct sk_buff * skb)449 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
450 {
451 	unsigned long now = jiffies;
452 
453 	if (READ_ONCE(neigh->used) != now)
454 		WRITE_ONCE(neigh->used, now);
455 	if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
456 		return __neigh_event_send(neigh, skb);
457 	return 0;
458 }
459 
460 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
neigh_hh_bridge(struct hh_cache * hh,struct sk_buff * skb)461 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
462 {
463 	unsigned int seq, hh_alen;
464 
465 	do {
466 		seq = read_seqbegin(&hh->hh_lock);
467 		hh_alen = HH_DATA_ALIGN(ETH_HLEN);
468 		memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
469 	} while (read_seqretry(&hh->hh_lock, seq));
470 	return 0;
471 }
472 #endif
473 
neigh_hh_output(const struct hh_cache * hh,struct sk_buff * skb)474 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
475 {
476 	unsigned int hh_alen = 0;
477 	unsigned int seq;
478 	unsigned int hh_len;
479 
480 	do {
481 		seq = read_seqbegin(&hh->hh_lock);
482 		hh_len = READ_ONCE(hh->hh_len);
483 		if (likely(hh_len <= HH_DATA_MOD)) {
484 			hh_alen = HH_DATA_MOD;
485 
486 			/* skb_push() would proceed silently if we have room for
487 			 * the unaligned size but not for the aligned size:
488 			 * check headroom explicitly.
489 			 */
490 			if (likely(skb_headroom(skb) >= HH_DATA_MOD)) {
491 				/* this is inlined by gcc */
492 				memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
493 				       HH_DATA_MOD);
494 			}
495 		} else {
496 			hh_alen = HH_DATA_ALIGN(hh_len);
497 
498 			if (likely(skb_headroom(skb) >= hh_alen)) {
499 				memcpy(skb->data - hh_alen, hh->hh_data,
500 				       hh_alen);
501 			}
502 		}
503 	} while (read_seqretry(&hh->hh_lock, seq));
504 
505 	if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) {
506 		kfree_skb(skb);
507 		return NET_XMIT_DROP;
508 	}
509 
510 	__skb_push(skb, hh_len);
511 	return dev_queue_xmit(skb);
512 }
513 
neigh_output(struct neighbour * n,struct sk_buff * skb,bool skip_cache)514 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb,
515 			       bool skip_cache)
516 {
517 	const struct hh_cache *hh = &n->hh;
518 
519 	/* n->nud_state and hh->hh_len could be changed under us.
520 	 * neigh_hh_output() is taking care of the race later.
521 	 */
522 	if (!skip_cache &&
523 	    (READ_ONCE(n->nud_state) & NUD_CONNECTED) &&
524 	    READ_ONCE(hh->hh_len))
525 		return neigh_hh_output(hh, skb);
526 
527 	return n->output(n, skb);
528 }
529 
530 static inline struct neighbour *
__neigh_lookup(struct neigh_table * tbl,const void * pkey,struct net_device * dev,int creat)531 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
532 {
533 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
534 
535 	if (n || !creat)
536 		return n;
537 
538 	n = neigh_create(tbl, pkey, dev);
539 	return IS_ERR(n) ? NULL : n;
540 }
541 
542 static inline struct neighbour *
__neigh_lookup_errno(struct neigh_table * tbl,const void * pkey,struct net_device * dev)543 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
544   struct net_device *dev)
545 {
546 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
547 
548 	if (n)
549 		return n;
550 
551 	return neigh_create(tbl, pkey, dev);
552 }
553 
554 struct neighbour_cb {
555 	unsigned long sched_next;
556 	unsigned int flags;
557 };
558 
559 #define LOCALLY_ENQUEUED 0x1
560 
561 #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)
562 
neigh_ha_snapshot(char * dst,const struct neighbour * n,const struct net_device * dev)563 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
564 				     const struct net_device *dev)
565 {
566 	unsigned int seq;
567 
568 	do {
569 		seq = read_seqbegin(&n->ha_lock);
570 		memcpy(dst, n->ha, dev->addr_len);
571 	} while (read_seqretry(&n->ha_lock, seq));
572 }
573 
neigh_update_is_router(struct neighbour * neigh,u32 flags,int * notify)574 static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags,
575 					  int *notify)
576 {
577 	u8 ndm_flags = 0;
578 
579 	ndm_flags |= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0;
580 	if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) {
581 		if (ndm_flags & NTF_ROUTER)
582 			neigh->flags |= NTF_ROUTER;
583 		else
584 			neigh->flags &= ~NTF_ROUTER;
585 		*notify = 1;
586 	}
587 }
588 #endif
589