xref: /linux/include/net/neighbour.h (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 #ifndef _NET_NEIGHBOUR_H
2 #define _NET_NEIGHBOUR_H
3 
4 /*
5  *	Generic neighbour manipulation
6  *
7  *	Authors:
8  *	Pedro Roque		<roque@di.fc.ul.pt>
9  *	Alexey Kuznetsov	<kuznet@ms2.inr.ac.ru>
10  *
11  * 	Changes:
12  *
13  *	Harald Welte:		<laforge@gnumonks.org>
14  *		- Add neighbour cache statistics like rtstat
15  */
16 
17 /* The following flags & states are exported to user space,
18    so that they should be moved to include/linux/ directory.
19  */
20 
21 /*
22  *	Neighbor Cache Entry Flags
23  */
24 
25 #define NTF_PROXY	0x08	/* == ATF_PUBL */
26 #define NTF_ROUTER	0x80
27 
28 /*
29  *	Neighbor Cache Entry States.
30  */
31 
32 #define NUD_INCOMPLETE	0x01
33 #define NUD_REACHABLE	0x02
34 #define NUD_STALE	0x04
35 #define NUD_DELAY	0x08
36 #define NUD_PROBE	0x10
37 #define NUD_FAILED	0x20
38 
39 /* Dummy states */
40 #define NUD_NOARP	0x40
41 #define NUD_PERMANENT	0x80
42 #define NUD_NONE	0x00
43 
44 /* NUD_NOARP & NUD_PERMANENT are pseudostates, they never change
45    and make no address resolution or NUD.
46    NUD_PERMANENT is also cannot be deleted by garbage collectors.
47  */
48 
49 #ifdef __KERNEL__
50 
51 #include <asm/atomic.h>
52 #include <linux/netdevice.h>
53 #include <linux/skbuff.h>
54 #include <linux/rcupdate.h>
55 #include <linux/seq_file.h>
56 
57 #include <linux/err.h>
58 #include <linux/sysctl.h>
59 
60 #define NUD_IN_TIMER	(NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
61 #define NUD_VALID	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
62 #define NUD_CONNECTED	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
63 
64 struct neighbour;
65 
66 struct neigh_parms
67 {
68 	struct net_device *dev;
69 	struct neigh_parms *next;
70 	int	(*neigh_setup)(struct neighbour *);
71 	void	(*neigh_destructor)(struct neighbour *);
72 	struct neigh_table *tbl;
73 
74 	void	*sysctl_table;
75 
76 	int dead;
77 	atomic_t refcnt;
78 	struct rcu_head rcu_head;
79 
80 	int	base_reachable_time;
81 	int	retrans_time;
82 	int	gc_staletime;
83 	int	reachable_time;
84 	int	delay_probe_time;
85 
86 	int	queue_len;
87 	int	ucast_probes;
88 	int	app_probes;
89 	int	mcast_probes;
90 	int	anycast_delay;
91 	int	proxy_delay;
92 	int	proxy_qlen;
93 	int	locktime;
94 };
95 
96 struct neigh_statistics
97 {
98 	unsigned long allocs;		/* number of allocated neighs */
99 	unsigned long destroys;		/* number of destroyed neighs */
100 	unsigned long hash_grows;	/* number of hash resizes */
101 
102 	unsigned long res_failed;	/* nomber of failed resolutions */
103 
104 	unsigned long lookups;		/* number of lookups */
105 	unsigned long hits;		/* number of hits (among lookups) */
106 
107 	unsigned long rcv_probes_mcast;	/* number of received mcast ipv6 */
108 	unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
109 
110 	unsigned long periodic_gc_runs;	/* number of periodic GC runs */
111 	unsigned long forced_gc_runs;	/* number of forced GC runs */
112 };
113 
114 #define NEIGH_CACHE_STAT_INC(tbl, field)				\
115 	do {								\
116 		preempt_disable();					\
117 		(per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
118 		preempt_enable();					\
119 	} while (0)
120 
121 struct neighbour
122 {
123 	struct neighbour	*next;
124 	struct neigh_table	*tbl;
125 	struct neigh_parms	*parms;
126 	struct net_device		*dev;
127 	unsigned long		used;
128 	unsigned long		confirmed;
129 	unsigned long		updated;
130 	__u8			flags;
131 	__u8			nud_state;
132 	__u8			type;
133 	__u8			dead;
134 	atomic_t		probes;
135 	rwlock_t		lock;
136 	unsigned char		ha[(MAX_ADDR_LEN+sizeof(unsigned long)-1)&~(sizeof(unsigned long)-1)];
137 	struct hh_cache		*hh;
138 	atomic_t		refcnt;
139 	int			(*output)(struct sk_buff *skb);
140 	struct sk_buff_head	arp_queue;
141 	struct timer_list	timer;
142 	struct neigh_ops	*ops;
143 	u8			primary_key[0];
144 };
145 
146 struct neigh_ops
147 {
148 	int			family;
149 	void			(*solicit)(struct neighbour *, struct sk_buff*);
150 	void			(*error_report)(struct neighbour *, struct sk_buff*);
151 	int			(*output)(struct sk_buff*);
152 	int			(*connected_output)(struct sk_buff*);
153 	int			(*hh_output)(struct sk_buff*);
154 	int			(*queue_xmit)(struct sk_buff*);
155 };
156 
157 struct pneigh_entry
158 {
159 	struct pneigh_entry	*next;
160 	struct net_device		*dev;
161 	u8			key[0];
162 };
163 
164 /*
165  *	neighbour table manipulation
166  */
167 
168 
169 struct neigh_table
170 {
171 	struct neigh_table	*next;
172 	int			family;
173 	int			entry_size;
174 	int			key_len;
175 	__u32			(*hash)(const void *pkey, const struct net_device *);
176 	int			(*constructor)(struct neighbour *);
177 	int			(*pconstructor)(struct pneigh_entry *);
178 	void			(*pdestructor)(struct pneigh_entry *);
179 	void			(*proxy_redo)(struct sk_buff *skb);
180 	char			*id;
181 	struct neigh_parms	parms;
182 	/* HACK. gc_* shoul follow parms without a gap! */
183 	int			gc_interval;
184 	int			gc_thresh1;
185 	int			gc_thresh2;
186 	int			gc_thresh3;
187 	unsigned long		last_flush;
188 	struct timer_list 	gc_timer;
189 	struct timer_list 	proxy_timer;
190 	struct sk_buff_head	proxy_queue;
191 	atomic_t		entries;
192 	rwlock_t		lock;
193 	unsigned long		last_rand;
194 	kmem_cache_t		*kmem_cachep;
195 	struct neigh_statistics	*stats;
196 	struct neighbour	**hash_buckets;
197 	unsigned int		hash_mask;
198 	__u32			hash_rnd;
199 	unsigned int		hash_chain_gc;
200 	struct pneigh_entry	**phash_buckets;
201 #ifdef CONFIG_PROC_FS
202 	struct proc_dir_entry	*pde;
203 #endif
204 };
205 
206 /* flags for neigh_update() */
207 #define NEIGH_UPDATE_F_OVERRIDE			0x00000001
208 #define NEIGH_UPDATE_F_WEAK_OVERRIDE		0x00000002
209 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER	0x00000004
210 #define NEIGH_UPDATE_F_ISROUTER			0x40000000
211 #define NEIGH_UPDATE_F_ADMIN			0x80000000
212 
213 extern void			neigh_table_init(struct neigh_table *tbl);
214 extern void			neigh_table_init_no_netlink(struct neigh_table *tbl);
215 extern int			neigh_table_clear(struct neigh_table *tbl);
216 extern struct neighbour *	neigh_lookup(struct neigh_table *tbl,
217 					     const void *pkey,
218 					     struct net_device *dev);
219 extern struct neighbour *	neigh_lookup_nodev(struct neigh_table *tbl,
220 						   const void *pkey);
221 extern struct neighbour *	neigh_create(struct neigh_table *tbl,
222 					     const void *pkey,
223 					     struct net_device *dev);
224 extern void			neigh_destroy(struct neighbour *neigh);
225 extern int			__neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
226 extern int			neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
227 					     u32 flags);
228 extern void			neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
229 extern int			neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
230 extern int			neigh_resolve_output(struct sk_buff *skb);
231 extern int			neigh_connected_output(struct sk_buff *skb);
232 extern int			neigh_compat_output(struct sk_buff *skb);
233 extern struct neighbour 	*neigh_event_ns(struct neigh_table *tbl,
234 						u8 *lladdr, void *saddr,
235 						struct net_device *dev);
236 
237 extern struct neigh_parms	*neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
238 extern void			neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
239 extern void			neigh_parms_destroy(struct neigh_parms *parms);
240 extern unsigned long		neigh_rand_reach_time(unsigned long base);
241 
242 extern void			pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
243 					       struct sk_buff *skb);
244 extern struct pneigh_entry	*pneigh_lookup(struct neigh_table *tbl, const void *key, struct net_device *dev, int creat);
245 extern int			pneigh_delete(struct neigh_table *tbl, const void *key, struct net_device *dev);
246 
247 struct netlink_callback;
248 struct nlmsghdr;
249 extern int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
250 extern int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
251 extern int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
252 extern void neigh_app_ns(struct neighbour *n);
253 
254 extern int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
255 extern int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
256 
257 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
258 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
259 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
260 
261 struct neigh_seq_state {
262 	struct neigh_table *tbl;
263 	void *(*neigh_sub_iter)(struct neigh_seq_state *state,
264 				struct neighbour *n, loff_t *pos);
265 	unsigned int bucket;
266 	unsigned int flags;
267 #define NEIGH_SEQ_NEIGH_ONLY	0x00000001
268 #define NEIGH_SEQ_IS_PNEIGH	0x00000002
269 #define NEIGH_SEQ_SKIP_NOARP	0x00000004
270 };
271 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
272 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
273 extern void neigh_seq_stop(struct seq_file *, void *);
274 
275 extern int			neigh_sysctl_register(struct net_device *dev,
276 						      struct neigh_parms *p,
277 						      int p_id, int pdev_id,
278 						      char *p_name,
279 						      proc_handler *proc_handler,
280 						      ctl_handler *strategy);
281 extern void			neigh_sysctl_unregister(struct neigh_parms *p);
282 
283 static inline void __neigh_parms_put(struct neigh_parms *parms)
284 {
285 	atomic_dec(&parms->refcnt);
286 }
287 
288 static inline void neigh_parms_put(struct neigh_parms *parms)
289 {
290 	if (atomic_dec_and_test(&parms->refcnt))
291 		neigh_parms_destroy(parms);
292 }
293 
294 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
295 {
296 	atomic_inc(&parms->refcnt);
297 	return parms;
298 }
299 
300 /*
301  *	Neighbour references
302  */
303 
304 static inline void neigh_release(struct neighbour *neigh)
305 {
306 	if (atomic_dec_and_test(&neigh->refcnt))
307 		neigh_destroy(neigh);
308 }
309 
310 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
311 {
312 	if (neigh)
313 		atomic_inc(&neigh->refcnt);
314 	return neigh;
315 }
316 
317 #define neigh_hold(n)	atomic_inc(&(n)->refcnt)
318 
319 static inline void neigh_confirm(struct neighbour *neigh)
320 {
321 	if (neigh)
322 		neigh->confirmed = jiffies;
323 }
324 
325 static inline int neigh_is_connected(struct neighbour *neigh)
326 {
327 	return neigh->nud_state&NUD_CONNECTED;
328 }
329 
330 static inline int neigh_is_valid(struct neighbour *neigh)
331 {
332 	return neigh->nud_state&NUD_VALID;
333 }
334 
335 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
336 {
337 	neigh->used = jiffies;
338 	if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
339 		return __neigh_event_send(neigh, skb);
340 	return 0;
341 }
342 
343 static inline struct neighbour *
344 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
345 {
346 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
347 
348 	if (n || !creat)
349 		return n;
350 
351 	n = neigh_create(tbl, pkey, dev);
352 	return IS_ERR(n) ? NULL : n;
353 }
354 
355 static inline struct neighbour *
356 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
357   struct net_device *dev)
358 {
359 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
360 
361 	if (n)
362 		return n;
363 
364 	return neigh_create(tbl, pkey, dev);
365 }
366 
367 struct neighbour_cb {
368 	unsigned long sched_next;
369 	unsigned int flags;
370 };
371 
372 #define LOCALLY_ENQUEUED 0x1
373 
374 #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)
375 
376 #endif
377 #endif
378 
379 
380