xref: /linux/include/net/neighbour.h (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 
28 #define NUD_IN_TIMER	(NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
29 #define NUD_VALID	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
30 #define NUD_CONNECTED	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
31 
32 struct neighbour;
33 
34 struct neigh_parms
35 {
36 	struct net_device *dev;
37 	struct neigh_parms *next;
38 	int	(*neigh_setup)(struct neighbour *);
39 	void	(*neigh_destructor)(struct neighbour *);
40 	struct neigh_table *tbl;
41 
42 	void	*sysctl_table;
43 
44 	int dead;
45 	atomic_t refcnt;
46 	struct rcu_head rcu_head;
47 
48 	int	base_reachable_time;
49 	int	retrans_time;
50 	int	gc_staletime;
51 	int	reachable_time;
52 	int	delay_probe_time;
53 
54 	int	queue_len;
55 	int	ucast_probes;
56 	int	app_probes;
57 	int	mcast_probes;
58 	int	anycast_delay;
59 	int	proxy_delay;
60 	int	proxy_qlen;
61 	int	locktime;
62 };
63 
64 struct neigh_statistics
65 {
66 	unsigned long allocs;		/* number of allocated neighs */
67 	unsigned long destroys;		/* number of destroyed neighs */
68 	unsigned long hash_grows;	/* number of hash resizes */
69 
70 	unsigned long res_failed;	/* nomber of failed resolutions */
71 
72 	unsigned long lookups;		/* number of lookups */
73 	unsigned long hits;		/* number of hits (among lookups) */
74 
75 	unsigned long rcv_probes_mcast;	/* number of received mcast ipv6 */
76 	unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
77 
78 	unsigned long periodic_gc_runs;	/* number of periodic GC runs */
79 	unsigned long forced_gc_runs;	/* number of forced GC runs */
80 };
81 
82 #define NEIGH_CACHE_STAT_INC(tbl, field)				\
83 	do {								\
84 		preempt_disable();					\
85 		(per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
86 		preempt_enable();					\
87 	} while (0)
88 
89 struct neighbour
90 {
91 	struct neighbour	*next;
92 	struct neigh_table	*tbl;
93 	struct neigh_parms	*parms;
94 	struct net_device		*dev;
95 	unsigned long		used;
96 	unsigned long		confirmed;
97 	unsigned long		updated;
98 	__u8			flags;
99 	__u8			nud_state;
100 	__u8			type;
101 	__u8			dead;
102 	atomic_t		probes;
103 	rwlock_t		lock;
104 	unsigned char		ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
105 	struct hh_cache		*hh;
106 	atomic_t		refcnt;
107 	int			(*output)(struct sk_buff *skb);
108 	struct sk_buff_head	arp_queue;
109 	struct timer_list	timer;
110 	struct neigh_ops	*ops;
111 	u8			primary_key[0];
112 };
113 
114 struct neigh_ops
115 {
116 	int			family;
117 	void			(*solicit)(struct neighbour *, struct sk_buff*);
118 	void			(*error_report)(struct neighbour *, struct sk_buff*);
119 	int			(*output)(struct sk_buff*);
120 	int			(*connected_output)(struct sk_buff*);
121 	int			(*hh_output)(struct sk_buff*);
122 	int			(*queue_xmit)(struct sk_buff*);
123 };
124 
125 struct pneigh_entry
126 {
127 	struct pneigh_entry	*next;
128 	struct net_device		*dev;
129 	u8			flags;
130 	u8			key[0];
131 };
132 
133 /*
134  *	neighbour table manipulation
135  */
136 
137 
138 struct neigh_table
139 {
140 	struct neigh_table	*next;
141 	int			family;
142 	int			entry_size;
143 	int			key_len;
144 	__u32			(*hash)(const void *pkey, const struct net_device *);
145 	int			(*constructor)(struct neighbour *);
146 	int			(*pconstructor)(struct pneigh_entry *);
147 	void			(*pdestructor)(struct pneigh_entry *);
148 	void			(*proxy_redo)(struct sk_buff *skb);
149 	char			*id;
150 	struct neigh_parms	parms;
151 	/* HACK. gc_* shoul follow parms without a gap! */
152 	int			gc_interval;
153 	int			gc_thresh1;
154 	int			gc_thresh2;
155 	int			gc_thresh3;
156 	unsigned long		last_flush;
157 	struct timer_list 	gc_timer;
158 	struct timer_list 	proxy_timer;
159 	struct sk_buff_head	proxy_queue;
160 	atomic_t		entries;
161 	rwlock_t		lock;
162 	unsigned long		last_rand;
163 	struct kmem_cache		*kmem_cachep;
164 	struct neigh_statistics	*stats;
165 	struct neighbour	**hash_buckets;
166 	unsigned int		hash_mask;
167 	__u32			hash_rnd;
168 	unsigned int		hash_chain_gc;
169 	struct pneigh_entry	**phash_buckets;
170 #ifdef CONFIG_PROC_FS
171 	struct proc_dir_entry	*pde;
172 #endif
173 };
174 
175 /* flags for neigh_update() */
176 #define NEIGH_UPDATE_F_OVERRIDE			0x00000001
177 #define NEIGH_UPDATE_F_WEAK_OVERRIDE		0x00000002
178 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER	0x00000004
179 #define NEIGH_UPDATE_F_ISROUTER			0x40000000
180 #define NEIGH_UPDATE_F_ADMIN			0x80000000
181 
182 extern void			neigh_table_init(struct neigh_table *tbl);
183 extern void			neigh_table_init_no_netlink(struct neigh_table *tbl);
184 extern int			neigh_table_clear(struct neigh_table *tbl);
185 extern struct neighbour *	neigh_lookup(struct neigh_table *tbl,
186 					     const void *pkey,
187 					     struct net_device *dev);
188 extern struct neighbour *	neigh_lookup_nodev(struct neigh_table *tbl,
189 						   const void *pkey);
190 extern struct neighbour *	neigh_create(struct neigh_table *tbl,
191 					     const void *pkey,
192 					     struct net_device *dev);
193 extern void			neigh_destroy(struct neighbour *neigh);
194 extern int			__neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
195 extern int			neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
196 					     u32 flags);
197 extern void			neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
198 extern int			neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
199 extern int			neigh_resolve_output(struct sk_buff *skb);
200 extern int			neigh_connected_output(struct sk_buff *skb);
201 extern int			neigh_compat_output(struct sk_buff *skb);
202 extern struct neighbour 	*neigh_event_ns(struct neigh_table *tbl,
203 						u8 *lladdr, void *saddr,
204 						struct net_device *dev);
205 
206 extern struct neigh_parms	*neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
207 extern void			neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
208 extern void			neigh_parms_destroy(struct neigh_parms *parms);
209 extern unsigned long		neigh_rand_reach_time(unsigned long base);
210 
211 extern void			pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
212 					       struct sk_buff *skb);
213 extern struct pneigh_entry	*pneigh_lookup(struct neigh_table *tbl, const void *key, struct net_device *dev, int creat);
214 extern int			pneigh_delete(struct neigh_table *tbl, const void *key, struct net_device *dev);
215 
216 struct netlink_callback;
217 struct nlmsghdr;
218 extern int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
219 extern int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
220 extern int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
221 extern void neigh_app_ns(struct neighbour *n);
222 
223 extern int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
224 extern int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
225 
226 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
227 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
228 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
229 
230 struct neigh_seq_state {
231 	struct neigh_table *tbl;
232 	void *(*neigh_sub_iter)(struct neigh_seq_state *state,
233 				struct neighbour *n, loff_t *pos);
234 	unsigned int bucket;
235 	unsigned int flags;
236 #define NEIGH_SEQ_NEIGH_ONLY	0x00000001
237 #define NEIGH_SEQ_IS_PNEIGH	0x00000002
238 #define NEIGH_SEQ_SKIP_NOARP	0x00000004
239 };
240 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
241 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
242 extern void neigh_seq_stop(struct seq_file *, void *);
243 
244 extern int			neigh_sysctl_register(struct net_device *dev,
245 						      struct neigh_parms *p,
246 						      int p_id, int pdev_id,
247 						      char *p_name,
248 						      proc_handler *proc_handler,
249 						      ctl_handler *strategy);
250 extern void			neigh_sysctl_unregister(struct neigh_parms *p);
251 
252 static inline void __neigh_parms_put(struct neigh_parms *parms)
253 {
254 	atomic_dec(&parms->refcnt);
255 }
256 
257 static inline void neigh_parms_put(struct neigh_parms *parms)
258 {
259 	if (atomic_dec_and_test(&parms->refcnt))
260 		neigh_parms_destroy(parms);
261 }
262 
263 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
264 {
265 	atomic_inc(&parms->refcnt);
266 	return parms;
267 }
268 
269 /*
270  *	Neighbour references
271  */
272 
273 static inline void neigh_release(struct neighbour *neigh)
274 {
275 	if (atomic_dec_and_test(&neigh->refcnt))
276 		neigh_destroy(neigh);
277 }
278 
279 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
280 {
281 	if (neigh)
282 		atomic_inc(&neigh->refcnt);
283 	return neigh;
284 }
285 
286 #define neigh_hold(n)	atomic_inc(&(n)->refcnt)
287 
288 static inline void neigh_confirm(struct neighbour *neigh)
289 {
290 	if (neigh)
291 		neigh->confirmed = jiffies;
292 }
293 
294 static inline int neigh_is_connected(struct neighbour *neigh)
295 {
296 	return neigh->nud_state&NUD_CONNECTED;
297 }
298 
299 static inline int neigh_is_valid(struct neighbour *neigh)
300 {
301 	return neigh->nud_state&NUD_VALID;
302 }
303 
304 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
305 {
306 	neigh->used = jiffies;
307 	if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
308 		return __neigh_event_send(neigh, skb);
309 	return 0;
310 }
311 
312 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
313 {
314 	unsigned seq;
315 	int hh_len;
316 
317 	do {
318 		int hh_alen;
319 
320 		seq = read_seqbegin(&hh->hh_lock);
321 		hh_len = hh->hh_len;
322 		hh_alen = HH_DATA_ALIGN(hh_len);
323 		memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
324 	} while (read_seqretry(&hh->hh_lock, seq));
325 
326 	skb_push(skb, hh_len);
327 	return hh->hh_output(skb);
328 }
329 
330 static inline struct neighbour *
331 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
332 {
333 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
334 
335 	if (n || !creat)
336 		return n;
337 
338 	n = neigh_create(tbl, pkey, dev);
339 	return IS_ERR(n) ? NULL : n;
340 }
341 
342 static inline struct neighbour *
343 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
344   struct net_device *dev)
345 {
346 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
347 
348 	if (n)
349 		return n;
350 
351 	return neigh_create(tbl, pkey, dev);
352 }
353 
354 struct neighbour_cb {
355 	unsigned long sched_next;
356 	unsigned int flags;
357 };
358 
359 #define LOCALLY_ENQUEUED 0x1
360 
361 #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)
362 
363 #endif
364