xref: /linux/include/net/neighbour.h (revision e26207a3819684e9b4450a2d30bdd065fa92d9c7)
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 <linux/workqueue.h>
28 #include <net/rtnetlink.h>
29 
30 /*
31  * NUD stands for "neighbor unreachability detection"
32  */
33 
34 #define NUD_IN_TIMER	(NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
35 #define NUD_VALID	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
36 #define NUD_CONNECTED	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
37 
38 struct neighbour;
39 
40 struct neigh_parms {
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 	unsigned long allocs;		/* number of allocated neighs */
74 	unsigned long destroys;		/* number of destroyed neighs */
75 	unsigned long hash_grows;	/* number of hash resizes */
76 
77 	unsigned long res_failed;	/* number of failed resolutions */
78 
79 	unsigned long lookups;		/* number of lookups */
80 	unsigned long hits;		/* number of hits (among lookups) */
81 
82 	unsigned long rcv_probes_mcast;	/* number of received mcast ipv6 */
83 	unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
84 
85 	unsigned long periodic_gc_runs;	/* number of periodic GC runs */
86 	unsigned long forced_gc_runs;	/* number of forced GC runs */
87 
88 	unsigned long unres_discards;	/* number of unresolved drops */
89 };
90 
91 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
92 
93 struct neighbour {
94 	struct neighbour	*next;
95 	struct neigh_table	*tbl;
96 	struct neigh_parms	*parms;
97 	struct net_device		*dev;
98 	unsigned long		used;
99 	unsigned long		confirmed;
100 	unsigned long		updated;
101 	__u8			flags;
102 	__u8			nud_state;
103 	__u8			type;
104 	__u8			dead;
105 	atomic_t		probes;
106 	rwlock_t		lock;
107 	unsigned char		ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
108 	struct hh_cache		*hh;
109 	atomic_t		refcnt;
110 	int			(*output)(struct sk_buff *skb);
111 	struct sk_buff_head	arp_queue;
112 	struct timer_list	timer;
113 	const struct neigh_ops	*ops;
114 	u8			primary_key[0];
115 };
116 
117 struct neigh_ops {
118 	int			family;
119 	void			(*solicit)(struct neighbour *, struct sk_buff*);
120 	void			(*error_report)(struct neighbour *, struct sk_buff*);
121 	int			(*output)(struct sk_buff*);
122 	int			(*connected_output)(struct sk_buff*);
123 	int			(*hh_output)(struct sk_buff*);
124 	int			(*queue_xmit)(struct sk_buff*);
125 };
126 
127 struct pneigh_entry {
128 	struct pneigh_entry	*next;
129 #ifdef CONFIG_NET_NS
130 	struct net		*net;
131 #endif
132 	struct net_device	*dev;
133 	u8			flags;
134 	u8			key[0];
135 };
136 
137 /*
138  *	neighbour table manipulation
139  */
140 
141 
142 struct neigh_table {
143 	struct neigh_table	*next;
144 	int			family;
145 	int			entry_size;
146 	int			key_len;
147 	__u32			(*hash)(const void *pkey, const struct net_device *);
148 	int			(*constructor)(struct neighbour *);
149 	int			(*pconstructor)(struct pneigh_entry *);
150 	void			(*pdestructor)(struct pneigh_entry *);
151 	void			(*proxy_redo)(struct sk_buff *skb);
152 	char			*id;
153 	struct neigh_parms	parms;
154 	/* HACK. gc_* shoul follow parms without a gap! */
155 	int			gc_interval;
156 	int			gc_thresh1;
157 	int			gc_thresh2;
158 	int			gc_thresh3;
159 	unsigned long		last_flush;
160 	struct delayed_work	gc_work;
161 	struct timer_list 	proxy_timer;
162 	struct sk_buff_head	proxy_queue;
163 	atomic_t		entries;
164 	rwlock_t		lock;
165 	unsigned long		last_rand;
166 	struct kmem_cache		*kmem_cachep;
167 	struct neigh_statistics	*stats;
168 	struct neighbour	**hash_buckets;
169 	unsigned int		hash_mask;
170 	__u32			hash_rnd;
171 	struct pneigh_entry	**phash_buckets;
172 };
173 
174 /* flags for neigh_update() */
175 #define NEIGH_UPDATE_F_OVERRIDE			0x00000001
176 #define NEIGH_UPDATE_F_WEAK_OVERRIDE		0x00000002
177 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER	0x00000004
178 #define NEIGH_UPDATE_F_ISROUTER			0x40000000
179 #define NEIGH_UPDATE_F_ADMIN			0x80000000
180 
181 extern void			neigh_table_init(struct neigh_table *tbl);
182 extern void			neigh_table_init_no_netlink(struct neigh_table *tbl);
183 extern int			neigh_table_clear(struct neigh_table *tbl);
184 extern struct neighbour *	neigh_lookup(struct neigh_table *tbl,
185 					     const void *pkey,
186 					     struct net_device *dev);
187 extern struct neighbour *	neigh_lookup_nodev(struct neigh_table *tbl,
188 						   struct net *net,
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 
209 static inline
210 struct net			*neigh_parms_net(const struct neigh_parms *parms)
211 {
212 	return read_pnet(&parms->net);
213 }
214 
215 extern unsigned long		neigh_rand_reach_time(unsigned long base);
216 
217 extern void			pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
218 					       struct sk_buff *skb);
219 extern struct pneigh_entry	*pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
220 extern struct pneigh_entry	*__pneigh_lookup(struct neigh_table *tbl,
221 						 struct net *net,
222 						 const void *key,
223 						 struct net_device *dev);
224 extern int			pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
225 
226 static inline
227 struct net			*pneigh_net(const struct pneigh_entry *pneigh)
228 {
229 	return read_pnet(&pneigh->net);
230 }
231 
232 extern void neigh_app_ns(struct neighbour *n);
233 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
234 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
235 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
236 
237 struct neigh_seq_state {
238 	struct seq_net_private p;
239 	struct neigh_table *tbl;
240 	void *(*neigh_sub_iter)(struct neigh_seq_state *state,
241 				struct neighbour *n, loff_t *pos);
242 	unsigned int bucket;
243 	unsigned int flags;
244 #define NEIGH_SEQ_NEIGH_ONLY	0x00000001
245 #define NEIGH_SEQ_IS_PNEIGH	0x00000002
246 #define NEIGH_SEQ_SKIP_NOARP	0x00000004
247 };
248 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
249 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
250 extern void neigh_seq_stop(struct seq_file *, void *);
251 
252 extern int			neigh_sysctl_register(struct net_device *dev,
253 						      struct neigh_parms *p,
254 						      int p_id, int pdev_id,
255 						      char *p_name,
256 						      proc_handler *proc_handler);
257 extern void			neigh_sysctl_unregister(struct neigh_parms *p);
258 
259 static inline void __neigh_parms_put(struct neigh_parms *parms)
260 {
261 	atomic_dec(&parms->refcnt);
262 }
263 
264 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
265 {
266 	atomic_inc(&parms->refcnt);
267 	return parms;
268 }
269 
270 /*
271  *	Neighbour references
272  */
273 
274 static inline void neigh_release(struct neighbour *neigh)
275 {
276 	if (atomic_dec_and_test(&neigh->refcnt))
277 		neigh_destroy(neigh);
278 }
279 
280 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
281 {
282 	if (neigh)
283 		atomic_inc(&neigh->refcnt);
284 	return neigh;
285 }
286 
287 #define neigh_hold(n)	atomic_inc(&(n)->refcnt)
288 
289 static inline void neigh_confirm(struct neighbour *neigh)
290 {
291 	if (neigh)
292 		neigh->confirmed = jiffies;
293 }
294 
295 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
296 {
297 	neigh->used = jiffies;
298 	if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
299 		return __neigh_event_send(neigh, skb);
300 	return 0;
301 }
302 
303 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
304 {
305 	unsigned seq;
306 	int hh_len;
307 
308 	do {
309 		int hh_alen;
310 
311 		seq = read_seqbegin(&hh->hh_lock);
312 		hh_len = hh->hh_len;
313 		hh_alen = HH_DATA_ALIGN(hh_len);
314 		memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
315 	} while (read_seqretry(&hh->hh_lock, seq));
316 
317 	skb_push(skb, hh_len);
318 	return hh->hh_output(skb);
319 }
320 
321 static inline struct neighbour *
322 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
323 {
324 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
325 
326 	if (n || !creat)
327 		return n;
328 
329 	n = neigh_create(tbl, pkey, dev);
330 	return IS_ERR(n) ? NULL : n;
331 }
332 
333 static inline struct neighbour *
334 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
335   struct net_device *dev)
336 {
337 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
338 
339 	if (n)
340 		return n;
341 
342 	return neigh_create(tbl, pkey, dev);
343 }
344 
345 struct neighbour_cb {
346 	unsigned long sched_next;
347 	unsigned int flags;
348 };
349 
350 #define LOCALLY_ENQUEUED 0x1
351 
352 #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)
353 
354 #endif
355