xref: /openbmc/linux/include/net/neighbour.h (revision 384740dc)
1 #ifndef _NET_NEIGHBOUR_H
2 #define _NET_NEIGHBOUR_H
3 
4 #include <linux/neighbour.h>
5 
6 /*
7  *	Generic neighbour manipulation
8  *
9  *	Authors:
10  *	Pedro Roque		<roque@di.fc.ul.pt>
11  *	Alexey Kuznetsov	<kuznet@ms2.inr.ac.ru>
12  *
13  * 	Changes:
14  *
15  *	Harald Welte:		<laforge@gnumonks.org>
16  *		- Add neighbour cache statistics like rtstat
17  */
18 
19 #include <asm/atomic.h>
20 #include <linux/netdevice.h>
21 #include <linux/skbuff.h>
22 #include <linux/rcupdate.h>
23 #include <linux/seq_file.h>
24 
25 #include <linux/err.h>
26 #include <linux/sysctl.h>
27 #include <net/rtnetlink.h>
28 
29 /*
30  * NUD stands for "neighbor unreachability detection"
31  */
32 
33 #define NUD_IN_TIMER	(NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
34 #define NUD_VALID	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
35 #define NUD_CONNECTED	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
36 
37 struct neighbour;
38 
39 struct neigh_parms
40 {
41 #ifdef CONFIG_NET_NS
42 	struct net *net;
43 #endif
44 	struct net_device *dev;
45 	struct neigh_parms *next;
46 	int	(*neigh_setup)(struct neighbour *);
47 	void	(*neigh_cleanup)(struct neighbour *);
48 	struct neigh_table *tbl;
49 
50 	void	*sysctl_table;
51 
52 	int dead;
53 	atomic_t refcnt;
54 	struct rcu_head rcu_head;
55 
56 	int	base_reachable_time;
57 	int	retrans_time;
58 	int	gc_staletime;
59 	int	reachable_time;
60 	int	delay_probe_time;
61 
62 	int	queue_len;
63 	int	ucast_probes;
64 	int	app_probes;
65 	int	mcast_probes;
66 	int	anycast_delay;
67 	int	proxy_delay;
68 	int	proxy_qlen;
69 	int	locktime;
70 };
71 
72 struct neigh_statistics
73 {
74 	unsigned long allocs;		/* number of allocated neighs */
75 	unsigned long destroys;		/* number of destroyed neighs */
76 	unsigned long hash_grows;	/* number of hash resizes */
77 
78 	unsigned long res_failed;	/* number of failed resolutions */
79 
80 	unsigned long lookups;		/* number of lookups */
81 	unsigned long hits;		/* number of hits (among lookups) */
82 
83 	unsigned long rcv_probes_mcast;	/* number of received mcast ipv6 */
84 	unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
85 
86 	unsigned long periodic_gc_runs;	/* number of periodic GC runs */
87 	unsigned long forced_gc_runs;	/* number of forced GC runs */
88 
89 	unsigned long unres_discards;	/* number of unresolved drops */
90 };
91 
92 #define NEIGH_CACHE_STAT_INC(tbl, field)				\
93 	do {								\
94 		preempt_disable();					\
95 		(per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
96 		preempt_enable();					\
97 	} while (0)
98 
99 struct neighbour
100 {
101 	struct neighbour	*next;
102 	struct neigh_table	*tbl;
103 	struct neigh_parms	*parms;
104 	struct net_device		*dev;
105 	unsigned long		used;
106 	unsigned long		confirmed;
107 	unsigned long		updated;
108 	__u8			flags;
109 	__u8			nud_state;
110 	__u8			type;
111 	__u8			dead;
112 	atomic_t		probes;
113 	rwlock_t		lock;
114 	unsigned char		ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
115 	struct hh_cache		*hh;
116 	atomic_t		refcnt;
117 	int			(*output)(struct sk_buff *skb);
118 	struct sk_buff_head	arp_queue;
119 	struct timer_list	timer;
120 	struct neigh_ops	*ops;
121 	u8			primary_key[0];
122 };
123 
124 struct neigh_ops
125 {
126 	int			family;
127 	void			(*solicit)(struct neighbour *, struct sk_buff*);
128 	void			(*error_report)(struct neighbour *, struct sk_buff*);
129 	int			(*output)(struct sk_buff*);
130 	int			(*connected_output)(struct sk_buff*);
131 	int			(*hh_output)(struct sk_buff*);
132 	int			(*queue_xmit)(struct sk_buff*);
133 };
134 
135 struct pneigh_entry
136 {
137 	struct pneigh_entry	*next;
138 #ifdef CONFIG_NET_NS
139 	struct net		*net;
140 #endif
141 	struct net_device	*dev;
142 	u8			flags;
143 	u8			key[0];
144 };
145 
146 /*
147  *	neighbour table manipulation
148  */
149 
150 
151 struct neigh_table
152 {
153 	struct neigh_table	*next;
154 	int			family;
155 	int			entry_size;
156 	int			key_len;
157 	__u32			(*hash)(const void *pkey, const struct net_device *);
158 	int			(*constructor)(struct neighbour *);
159 	int			(*pconstructor)(struct pneigh_entry *);
160 	void			(*pdestructor)(struct pneigh_entry *);
161 	void			(*proxy_redo)(struct sk_buff *skb);
162 	char			*id;
163 	struct neigh_parms	parms;
164 	/* HACK. gc_* shoul follow parms without a gap! */
165 	int			gc_interval;
166 	int			gc_thresh1;
167 	int			gc_thresh2;
168 	int			gc_thresh3;
169 	unsigned long		last_flush;
170 	struct timer_list 	gc_timer;
171 	struct timer_list 	proxy_timer;
172 	struct sk_buff_head	proxy_queue;
173 	atomic_t		entries;
174 	rwlock_t		lock;
175 	unsigned long		last_rand;
176 	struct kmem_cache		*kmem_cachep;
177 	struct neigh_statistics	*stats;
178 	struct neighbour	**hash_buckets;
179 	unsigned int		hash_mask;
180 	__u32			hash_rnd;
181 	unsigned int		hash_chain_gc;
182 	struct pneigh_entry	**phash_buckets;
183 #ifdef CONFIG_PROC_FS
184 	struct proc_dir_entry	*pde;
185 #endif
186 };
187 
188 /* flags for neigh_update() */
189 #define NEIGH_UPDATE_F_OVERRIDE			0x00000001
190 #define NEIGH_UPDATE_F_WEAK_OVERRIDE		0x00000002
191 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER	0x00000004
192 #define NEIGH_UPDATE_F_ISROUTER			0x40000000
193 #define NEIGH_UPDATE_F_ADMIN			0x80000000
194 
195 extern void			neigh_table_init(struct neigh_table *tbl);
196 extern void			neigh_table_init_no_netlink(struct neigh_table *tbl);
197 extern int			neigh_table_clear(struct neigh_table *tbl);
198 extern struct neighbour *	neigh_lookup(struct neigh_table *tbl,
199 					     const void *pkey,
200 					     struct net_device *dev);
201 extern struct neighbour *	neigh_lookup_nodev(struct neigh_table *tbl,
202 						   struct net *net,
203 						   const void *pkey);
204 extern struct neighbour *	neigh_create(struct neigh_table *tbl,
205 					     const void *pkey,
206 					     struct net_device *dev);
207 extern void			neigh_destroy(struct neighbour *neigh);
208 extern int			__neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
209 extern int			neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
210 					     u32 flags);
211 extern void			neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
212 extern int			neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
213 extern int			neigh_resolve_output(struct sk_buff *skb);
214 extern int			neigh_connected_output(struct sk_buff *skb);
215 extern int			neigh_compat_output(struct sk_buff *skb);
216 extern struct neighbour 	*neigh_event_ns(struct neigh_table *tbl,
217 						u8 *lladdr, void *saddr,
218 						struct net_device *dev);
219 
220 extern struct neigh_parms	*neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
221 extern void			neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
222 
223 static inline
224 struct net			*neigh_parms_net(const struct neigh_parms *parms)
225 {
226 #ifdef CONFIG_NET_NS
227 	return parms->net;
228 #else
229 	return &init_net;
230 #endif
231 }
232 
233 extern unsigned long		neigh_rand_reach_time(unsigned long base);
234 
235 extern void			pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
236 					       struct sk_buff *skb);
237 extern struct pneigh_entry	*pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
238 extern struct pneigh_entry	*__pneigh_lookup(struct neigh_table *tbl,
239 						 struct net *net,
240 						 const void *key,
241 						 struct net_device *dev);
242 extern int			pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
243 
244 static inline
245 struct net			*pneigh_net(const struct pneigh_entry *pneigh)
246 {
247 #ifdef CONFIG_NET_NS
248 	return pneigh->net;
249 #else
250 	return &init_net;
251 #endif
252 }
253 
254 extern void neigh_app_ns(struct neighbour *n);
255 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
256 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
257 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
258 
259 struct neigh_seq_state {
260 	struct seq_net_private p;
261 	struct neigh_table *tbl;
262 	void *(*neigh_sub_iter)(struct neigh_seq_state *state,
263 				struct neighbour *n, loff_t *pos);
264 	unsigned int bucket;
265 	unsigned int flags;
266 #define NEIGH_SEQ_NEIGH_ONLY	0x00000001
267 #define NEIGH_SEQ_IS_PNEIGH	0x00000002
268 #define NEIGH_SEQ_SKIP_NOARP	0x00000004
269 };
270 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
271 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
272 extern void neigh_seq_stop(struct seq_file *, void *);
273 
274 extern int			neigh_sysctl_register(struct net_device *dev,
275 						      struct neigh_parms *p,
276 						      int p_id, int pdev_id,
277 						      char *p_name,
278 						      proc_handler *proc_handler,
279 						      ctl_handler *strategy);
280 extern void			neigh_sysctl_unregister(struct neigh_parms *p);
281 
282 static inline void __neigh_parms_put(struct neigh_parms *parms)
283 {
284 	atomic_dec(&parms->refcnt);
285 }
286 
287 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
288 {
289 	atomic_inc(&parms->refcnt);
290 	return parms;
291 }
292 
293 /*
294  *	Neighbour references
295  */
296 
297 static inline void neigh_release(struct neighbour *neigh)
298 {
299 	if (atomic_dec_and_test(&neigh->refcnt))
300 		neigh_destroy(neigh);
301 }
302 
303 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
304 {
305 	if (neigh)
306 		atomic_inc(&neigh->refcnt);
307 	return neigh;
308 }
309 
310 #define neigh_hold(n)	atomic_inc(&(n)->refcnt)
311 
312 static inline void neigh_confirm(struct neighbour *neigh)
313 {
314 	if (neigh)
315 		neigh->confirmed = jiffies;
316 }
317 
318 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
319 {
320 	neigh->used = jiffies;
321 	if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
322 		return __neigh_event_send(neigh, skb);
323 	return 0;
324 }
325 
326 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
327 {
328 	unsigned seq;
329 	int hh_len;
330 
331 	do {
332 		int hh_alen;
333 
334 		seq = read_seqbegin(&hh->hh_lock);
335 		hh_len = hh->hh_len;
336 		hh_alen = HH_DATA_ALIGN(hh_len);
337 		memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
338 	} while (read_seqretry(&hh->hh_lock, seq));
339 
340 	skb_push(skb, hh_len);
341 	return hh->hh_output(skb);
342 }
343 
344 static inline struct neighbour *
345 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
346 {
347 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
348 
349 	if (n || !creat)
350 		return n;
351 
352 	n = neigh_create(tbl, pkey, dev);
353 	return IS_ERR(n) ? NULL : n;
354 }
355 
356 static inline struct neighbour *
357 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
358   struct net_device *dev)
359 {
360 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
361 
362 	if (n)
363 		return n;
364 
365 	return neigh_create(tbl, pkey, dev);
366 }
367 
368 struct neighbour_cb {
369 	unsigned long sched_next;
370 	unsigned int flags;
371 };
372 
373 #define LOCALLY_ENQUEUED 0x1
374 
375 #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)
376 
377 #endif
378