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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 <linux/android_kabi.h>
32 #include <net/rtnetlink.h>
33 
34 /*
35  * NUD stands for "neighbor unreachability detection"
36  */
37 
38 #define NUD_IN_TIMER	(NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
39 #define NUD_VALID	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
40 #define NUD_CONNECTED	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
41 
42 struct neighbour;
43 
44 enum {
45 	NEIGH_VAR_MCAST_PROBES,
46 	NEIGH_VAR_UCAST_PROBES,
47 	NEIGH_VAR_APP_PROBES,
48 	NEIGH_VAR_MCAST_REPROBES,
49 	NEIGH_VAR_RETRANS_TIME,
50 	NEIGH_VAR_BASE_REACHABLE_TIME,
51 	NEIGH_VAR_DELAY_PROBE_TIME,
52 	NEIGH_VAR_INTERVAL_PROBE_TIME_MS,
53 	NEIGH_VAR_GC_STALETIME,
54 	NEIGH_VAR_QUEUE_LEN_BYTES,
55 	NEIGH_VAR_PROXY_QLEN,
56 	NEIGH_VAR_ANYCAST_DELAY,
57 	NEIGH_VAR_PROXY_DELAY,
58 	NEIGH_VAR_LOCKTIME,
59 #define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1)
60 	/* Following are used as a second way to access one of the above */
61 	NEIGH_VAR_QUEUE_LEN, /* same data as NEIGH_VAR_QUEUE_LEN_BYTES */
62 	NEIGH_VAR_RETRANS_TIME_MS, /* same data as NEIGH_VAR_RETRANS_TIME */
63 	NEIGH_VAR_BASE_REACHABLE_TIME_MS, /* same data as NEIGH_VAR_BASE_REACHABLE_TIME */
64 	/* Following are used by "default" only */
65 	NEIGH_VAR_GC_INTERVAL,
66 	NEIGH_VAR_GC_THRESH1,
67 	NEIGH_VAR_GC_THRESH2,
68 	NEIGH_VAR_GC_THRESH3,
69 	NEIGH_VAR_MAX
70 };
71 
72 struct neigh_parms {
73 	possible_net_t net;
74 	struct net_device *dev;
75 	netdevice_tracker dev_tracker;
76 	struct list_head list;
77 	int	(*neigh_setup)(struct neighbour *);
78 	struct neigh_table *tbl;
79 
80 	void	*sysctl_table;
81 
82 	int dead;
83 	refcount_t refcnt;
84 	struct rcu_head rcu_head;
85 
86 	int	reachable_time;
87 	u32	qlen;
88 	int	data[NEIGH_VAR_DATA_MAX];
89 	DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX);
90 
91 	ANDROID_KABI_RESERVE(1);
92 };
93 
neigh_var_set(struct neigh_parms * p,int index,int val)94 static inline void neigh_var_set(struct neigh_parms *p, int index, int val)
95 {
96 	set_bit(index, p->data_state);
97 	p->data[index] = val;
98 }
99 
100 #define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr])
101 
102 /* In ndo_neigh_setup, NEIGH_VAR_INIT should be used.
103  * In other cases, NEIGH_VAR_SET should be used.
104  */
105 #define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val)
106 #define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val)
107 
neigh_parms_data_state_setall(struct neigh_parms * p)108 static inline void neigh_parms_data_state_setall(struct neigh_parms *p)
109 {
110 	bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX);
111 }
112 
neigh_parms_data_state_cleanall(struct neigh_parms * p)113 static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p)
114 {
115 	bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX);
116 }
117 
118 struct neigh_statistics {
119 	unsigned long allocs;		/* number of allocated neighs */
120 	unsigned long destroys;		/* number of destroyed neighs */
121 	unsigned long hash_grows;	/* number of hash resizes */
122 
123 	unsigned long res_failed;	/* number of failed resolutions */
124 
125 	unsigned long lookups;		/* number of lookups */
126 	unsigned long hits;		/* number of hits (among lookups) */
127 
128 	unsigned long rcv_probes_mcast;	/* number of received mcast ipv6 */
129 	unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
130 
131 	unsigned long periodic_gc_runs;	/* number of periodic GC runs */
132 	unsigned long forced_gc_runs;	/* number of forced GC runs */
133 
134 	unsigned long unres_discards;	/* number of unresolved drops */
135 	unsigned long table_fulls;      /* times even gc couldn't help */
136 };
137 
138 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
139 
140 struct neighbour {
141 	struct neighbour __rcu	*next;
142 	struct neigh_table	*tbl;
143 	struct neigh_parms	*parms;
144 	unsigned long		confirmed;
145 	unsigned long		updated;
146 	rwlock_t		lock;
147 	refcount_t		refcnt;
148 	unsigned int		arp_queue_len_bytes;
149 	struct sk_buff_head	arp_queue;
150 	struct timer_list	timer;
151 	unsigned long		used;
152 	atomic_t		probes;
153 	u8			nud_state;
154 	u8			type;
155 	u8			dead;
156 	u8			protocol;
157 	u32			flags;
158 	seqlock_t		ha_lock;
159 	unsigned char		ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))] __aligned(8);
160 	struct hh_cache		hh;
161 	int			(*output)(struct neighbour *, struct sk_buff *);
162 	const struct neigh_ops	*ops;
163 	struct list_head	gc_list;
164 	struct list_head	managed_list;
165 	struct rcu_head		rcu;
166 	struct net_device	*dev;
167 	netdevice_tracker	dev_tracker;
168 
169 	ANDROID_KABI_RESERVE(1);
170 
171 	u8			primary_key[0];
172 } __randomize_layout;
173 
174 struct neigh_ops {
175 	int			family;
176 	void			(*solicit)(struct neighbour *, struct sk_buff *);
177 	void			(*error_report)(struct neighbour *, struct sk_buff *);
178 	int			(*output)(struct neighbour *, struct sk_buff *);
179 	int			(*connected_output)(struct neighbour *, struct sk_buff *);
180 };
181 
182 struct pneigh_entry {
183 	struct pneigh_entry	*next;
184 	possible_net_t		net;
185 	struct net_device	*dev;
186 	netdevice_tracker	dev_tracker;
187 	u32			flags;
188 	u8			protocol;
189 	u32			key[];
190 };
191 
192 /*
193  *	neighbour table manipulation
194  */
195 
196 #define NEIGH_NUM_HASH_RND	4
197 
198 struct neigh_hash_table {
199 	struct neighbour __rcu	**hash_buckets;
200 	unsigned int		hash_shift;
201 	__u32			hash_rnd[NEIGH_NUM_HASH_RND];
202 	struct rcu_head		rcu;
203 };
204 
205 
206 struct neigh_table {
207 	int			family;
208 	unsigned int		entry_size;
209 	unsigned int		key_len;
210 	__be16			protocol;
211 	__u32			(*hash)(const void *pkey,
212 					const struct net_device *dev,
213 					__u32 *hash_rnd);
214 	bool			(*key_eq)(const struct neighbour *, const void *pkey);
215 	int			(*constructor)(struct neighbour *);
216 	int			(*pconstructor)(struct pneigh_entry *);
217 	void			(*pdestructor)(struct pneigh_entry *);
218 	void			(*proxy_redo)(struct sk_buff *skb);
219 	int			(*is_multicast)(const void *pkey);
220 	bool			(*allow_add)(const struct net_device *dev,
221 					     struct netlink_ext_ack *extack);
222 	char			*id;
223 	struct neigh_parms	parms;
224 	struct list_head	parms_list;
225 	int			gc_interval;
226 	int			gc_thresh1;
227 	int			gc_thresh2;
228 	int			gc_thresh3;
229 	unsigned long		last_flush;
230 	struct delayed_work	gc_work;
231 	struct delayed_work	managed_work;
232 	struct timer_list 	proxy_timer;
233 	struct sk_buff_head	proxy_queue;
234 	atomic_t		entries;
235 	atomic_t		gc_entries;
236 	struct list_head	gc_list;
237 	struct list_head	managed_list;
238 	rwlock_t		lock;
239 	unsigned long		last_rand;
240 	struct neigh_statistics	__percpu *stats;
241 	struct neigh_hash_table __rcu *nht;
242 	struct pneigh_entry	**phash_buckets;
243 
244 	ANDROID_KABI_RESERVE(1);
245 };
246 
247 enum {
248 	NEIGH_ARP_TABLE = 0,
249 	NEIGH_ND_TABLE = 1,
250 	NEIGH_DN_TABLE = 2,
251 	NEIGH_NR_TABLES,
252 	NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
253 };
254 
neigh_parms_family(struct neigh_parms * p)255 static inline int neigh_parms_family(struct neigh_parms *p)
256 {
257 	return p->tbl->family;
258 }
259 
260 #define NEIGH_PRIV_ALIGN	sizeof(long long)
261 #define NEIGH_ENTRY_SIZE(size)	ALIGN((size), NEIGH_PRIV_ALIGN)
262 
neighbour_priv(const struct neighbour * n)263 static inline void *neighbour_priv(const struct neighbour *n)
264 {
265 	return (char *)n + n->tbl->entry_size;
266 }
267 
268 /* flags for neigh_update() */
269 #define NEIGH_UPDATE_F_OVERRIDE			BIT(0)
270 #define NEIGH_UPDATE_F_WEAK_OVERRIDE		BIT(1)
271 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER	BIT(2)
272 #define NEIGH_UPDATE_F_USE			BIT(3)
273 #define NEIGH_UPDATE_F_MANAGED			BIT(4)
274 #define NEIGH_UPDATE_F_EXT_LEARNED		BIT(5)
275 #define NEIGH_UPDATE_F_ISROUTER			BIT(6)
276 #define NEIGH_UPDATE_F_ADMIN			BIT(7)
277 
278 /* In-kernel representation for NDA_FLAGS_EXT flags: */
279 #define NTF_OLD_MASK		0xff
280 #define NTF_EXT_SHIFT		8
281 #define NTF_EXT_MASK		(NTF_EXT_MANAGED)
282 
283 #define NTF_MANAGED		(NTF_EXT_MANAGED << NTF_EXT_SHIFT)
284 
285 extern const struct nla_policy nda_policy[];
286 
neigh_key_eq32(const struct neighbour * n,const void * pkey)287 static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey)
288 {
289 	return *(const u32 *)n->primary_key == *(const u32 *)pkey;
290 }
291 
neigh_key_eq128(const struct neighbour * n,const void * pkey)292 static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey)
293 {
294 	const u32 *n32 = (const u32 *)n->primary_key;
295 	const u32 *p32 = pkey;
296 
297 	return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
298 		(n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0;
299 }
300 
___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)301 static inline struct neighbour *___neigh_lookup_noref(
302 	struct neigh_table *tbl,
303 	bool (*key_eq)(const struct neighbour *n, const void *pkey),
304 	__u32 (*hash)(const void *pkey,
305 		      const struct net_device *dev,
306 		      __u32 *hash_rnd),
307 	const void *pkey,
308 	struct net_device *dev)
309 {
310 	struct neigh_hash_table *nht = rcu_dereference(tbl->nht);
311 	struct neighbour *n;
312 	u32 hash_val;
313 
314 	hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
315 	for (n = rcu_dereference(nht->hash_buckets[hash_val]);
316 	     n != NULL;
317 	     n = rcu_dereference(n->next)) {
318 		if (n->dev == dev && key_eq(n, pkey))
319 			return n;
320 	}
321 
322 	return NULL;
323 }
324 
__neigh_lookup_noref(struct neigh_table * tbl,const void * pkey,struct net_device * dev)325 static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl,
326 						     const void *pkey,
327 						     struct net_device *dev)
328 {
329 	return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
330 }
331 
neigh_confirm(struct neighbour * n)332 static inline void neigh_confirm(struct neighbour *n)
333 {
334 	if (n) {
335 		unsigned long now = jiffies;
336 
337 		/* avoid dirtying neighbour */
338 		if (READ_ONCE(n->confirmed) != now)
339 			WRITE_ONCE(n->confirmed, now);
340 	}
341 }
342 
343 void neigh_table_init(int index, struct neigh_table *tbl);
344 int neigh_table_clear(int index, struct neigh_table *tbl);
345 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
346 			       struct net_device *dev);
347 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
348 				 struct net_device *dev, bool want_ref);
neigh_create(struct neigh_table * tbl,const void * pkey,struct net_device * dev)349 static inline struct neighbour *neigh_create(struct neigh_table *tbl,
350 					     const void *pkey,
351 					     struct net_device *dev)
352 {
353 	return __neigh_create(tbl, pkey, dev, true);
354 }
355 void neigh_destroy(struct neighbour *neigh);
356 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb,
357 		       const bool immediate_ok);
358 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
359 		 u32 nlmsg_pid);
360 void __neigh_set_probe_once(struct neighbour *neigh);
361 bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
362 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
363 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
364 int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev);
365 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
366 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
367 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
368 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
369 						u8 *lladdr, void *saddr,
370 						struct net_device *dev);
371 
372 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
373 				      struct neigh_table *tbl);
374 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
375 
376 static inline
neigh_parms_net(const struct neigh_parms * parms)377 struct net *neigh_parms_net(const struct neigh_parms *parms)
378 {
379 	return read_pnet(&parms->net);
380 }
381 
382 unsigned long neigh_rand_reach_time(unsigned long base);
383 
384 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
385 		    struct sk_buff *skb);
386 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
387 				   const void *key, struct net_device *dev,
388 				   int creat);
389 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
390 				     const void *key, struct net_device *dev);
391 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
392 		  struct net_device *dev);
393 
pneigh_net(const struct pneigh_entry * pneigh)394 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
395 {
396 	return read_pnet(&pneigh->net);
397 }
398 
399 void neigh_app_ns(struct neighbour *n);
400 void neigh_for_each(struct neigh_table *tbl,
401 		    void (*cb)(struct neighbour *, void *), void *cookie);
402 void __neigh_for_each_release(struct neigh_table *tbl,
403 			      int (*cb)(struct neighbour *));
404 int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *);
405 void pneigh_for_each(struct neigh_table *tbl,
406 		     void (*cb)(struct pneigh_entry *));
407 
408 struct neigh_seq_state {
409 	struct seq_net_private p;
410 	struct neigh_table *tbl;
411 	struct neigh_hash_table *nht;
412 	void *(*neigh_sub_iter)(struct neigh_seq_state *state,
413 				struct neighbour *n, loff_t *pos);
414 	unsigned int bucket;
415 	unsigned int flags;
416 #define NEIGH_SEQ_NEIGH_ONLY	0x00000001
417 #define NEIGH_SEQ_IS_PNEIGH	0x00000002
418 #define NEIGH_SEQ_SKIP_NOARP	0x00000004
419 };
420 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
421 		      unsigned int);
422 void *neigh_seq_next(struct seq_file *, void *, loff_t *);
423 void neigh_seq_stop(struct seq_file *, void *);
424 
425 int neigh_proc_dointvec(struct ctl_table *ctl, int write,
426 			void *buffer, size_t *lenp, loff_t *ppos);
427 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
428 				void *buffer,
429 				size_t *lenp, loff_t *ppos);
430 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
431 				   void *buffer, size_t *lenp, loff_t *ppos);
432 
433 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
434 			  proc_handler *proc_handler);
435 void neigh_sysctl_unregister(struct neigh_parms *p);
436 
__neigh_parms_put(struct neigh_parms * parms)437 static inline void __neigh_parms_put(struct neigh_parms *parms)
438 {
439 	refcount_dec(&parms->refcnt);
440 }
441 
neigh_parms_clone(struct neigh_parms * parms)442 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
443 {
444 	refcount_inc(&parms->refcnt);
445 	return parms;
446 }
447 
448 /*
449  *	Neighbour references
450  */
451 
neigh_release(struct neighbour * neigh)452 static inline void neigh_release(struct neighbour *neigh)
453 {
454 	if (refcount_dec_and_test(&neigh->refcnt))
455 		neigh_destroy(neigh);
456 }
457 
neigh_clone(struct neighbour * neigh)458 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
459 {
460 	if (neigh)
461 		refcount_inc(&neigh->refcnt);
462 	return neigh;
463 }
464 
465 #define neigh_hold(n)	refcount_inc(&(n)->refcnt)
466 
neigh_event_send_probe(struct neighbour * neigh,struct sk_buff * skb,const bool immediate_ok)467 static __always_inline int neigh_event_send_probe(struct neighbour *neigh,
468 						  struct sk_buff *skb,
469 						  const bool immediate_ok)
470 {
471 	unsigned long now = jiffies;
472 
473 	if (READ_ONCE(neigh->used) != now)
474 		WRITE_ONCE(neigh->used, now);
475 	if (!(READ_ONCE(neigh->nud_state) & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE)))
476 		return __neigh_event_send(neigh, skb, immediate_ok);
477 	return 0;
478 }
479 
neigh_event_send(struct neighbour * neigh,struct sk_buff * skb)480 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
481 {
482 	return neigh_event_send_probe(neigh, skb, true);
483 }
484 
485 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
neigh_hh_bridge(struct hh_cache * hh,struct sk_buff * skb)486 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
487 {
488 	unsigned int seq, hh_alen;
489 
490 	do {
491 		seq = read_seqbegin(&hh->hh_lock);
492 		hh_alen = HH_DATA_ALIGN(ETH_HLEN);
493 		memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
494 	} while (read_seqretry(&hh->hh_lock, seq));
495 	return 0;
496 }
497 #endif
498 
neigh_hh_output(const struct hh_cache * hh,struct sk_buff * skb)499 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
500 {
501 	unsigned int hh_alen = 0;
502 	unsigned int seq;
503 	unsigned int hh_len;
504 
505 	do {
506 		seq = read_seqbegin(&hh->hh_lock);
507 		hh_len = READ_ONCE(hh->hh_len);
508 		if (likely(hh_len <= HH_DATA_MOD)) {
509 			hh_alen = HH_DATA_MOD;
510 
511 			/* skb_push() would proceed silently if we have room for
512 			 * the unaligned size but not for the aligned size:
513 			 * check headroom explicitly.
514 			 */
515 			if (likely(skb_headroom(skb) >= HH_DATA_MOD)) {
516 				/* this is inlined by gcc */
517 				memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
518 				       HH_DATA_MOD);
519 			}
520 		} else {
521 			hh_alen = HH_DATA_ALIGN(hh_len);
522 
523 			if (likely(skb_headroom(skb) >= hh_alen)) {
524 				memcpy(skb->data - hh_alen, hh->hh_data,
525 				       hh_alen);
526 			}
527 		}
528 	} while (read_seqretry(&hh->hh_lock, seq));
529 
530 	if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) {
531 		kfree_skb(skb);
532 		return NET_XMIT_DROP;
533 	}
534 
535 	__skb_push(skb, hh_len);
536 	return dev_queue_xmit(skb);
537 }
538 
neigh_output(struct neighbour * n,struct sk_buff * skb,bool skip_cache)539 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb,
540 			       bool skip_cache)
541 {
542 	const struct hh_cache *hh = &n->hh;
543 
544 	/* n->nud_state and hh->hh_len could be changed under us.
545 	 * neigh_hh_output() is taking care of the race later.
546 	 */
547 	if (!skip_cache &&
548 	    (READ_ONCE(n->nud_state) & NUD_CONNECTED) &&
549 	    READ_ONCE(hh->hh_len))
550 		return neigh_hh_output(hh, skb);
551 
552 	return READ_ONCE(n->output)(n, skb);
553 }
554 
555 static inline struct neighbour *
__neigh_lookup(struct neigh_table * tbl,const void * pkey,struct net_device * dev,int creat)556 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
557 {
558 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
559 
560 	if (n || !creat)
561 		return n;
562 
563 	n = neigh_create(tbl, pkey, dev);
564 	return IS_ERR(n) ? NULL : n;
565 }
566 
567 static inline struct neighbour *
__neigh_lookup_errno(struct neigh_table * tbl,const void * pkey,struct net_device * dev)568 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
569   struct net_device *dev)
570 {
571 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
572 
573 	if (n)
574 		return n;
575 
576 	return neigh_create(tbl, pkey, dev);
577 }
578 
579 struct neighbour_cb {
580 	unsigned long sched_next;
581 	unsigned int flags;
582 };
583 
584 #define LOCALLY_ENQUEUED 0x1
585 
586 #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)
587 
neigh_ha_snapshot(char * dst,const struct neighbour * n,const struct net_device * dev)588 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
589 				     const struct net_device *dev)
590 {
591 	unsigned int seq;
592 
593 	do {
594 		seq = read_seqbegin(&n->ha_lock);
595 		memcpy(dst, n->ha, dev->addr_len);
596 	} while (read_seqretry(&n->ha_lock, seq));
597 }
598 
neigh_update_is_router(struct neighbour * neigh,u32 flags,int * notify)599 static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags,
600 					  int *notify)
601 {
602 	u8 ndm_flags = 0;
603 
604 	ndm_flags |= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0;
605 	if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) {
606 		if (ndm_flags & NTF_ROUTER)
607 			neigh->flags |= NTF_ROUTER;
608 		else
609 			neigh->flags &= ~NTF_ROUTER;
610 		*notify = 1;
611 	}
612 }
613 #endif
614