xref: /openbmc/linux/include/net/neighbour.h (revision 22246614)
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;	/* nomber 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 
90 #define NEIGH_CACHE_STAT_INC(tbl, field)				\
91 	do {								\
92 		preempt_disable();					\
93 		(per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
94 		preempt_enable();					\
95 	} while (0)
96 
97 struct neighbour
98 {
99 	struct neighbour	*next;
100 	struct neigh_table	*tbl;
101 	struct neigh_parms	*parms;
102 	struct net_device		*dev;
103 	unsigned long		used;
104 	unsigned long		confirmed;
105 	unsigned long		updated;
106 	__u8			flags;
107 	__u8			nud_state;
108 	__u8			type;
109 	__u8			dead;
110 	atomic_t		probes;
111 	rwlock_t		lock;
112 	unsigned char		ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
113 	struct hh_cache		*hh;
114 	atomic_t		refcnt;
115 	int			(*output)(struct sk_buff *skb);
116 	struct sk_buff_head	arp_queue;
117 	struct timer_list	timer;
118 	struct neigh_ops	*ops;
119 	u8			primary_key[0];
120 };
121 
122 struct neigh_ops
123 {
124 	int			family;
125 	void			(*solicit)(struct neighbour *, struct sk_buff*);
126 	void			(*error_report)(struct neighbour *, struct sk_buff*);
127 	int			(*output)(struct sk_buff*);
128 	int			(*connected_output)(struct sk_buff*);
129 	int			(*hh_output)(struct sk_buff*);
130 	int			(*queue_xmit)(struct sk_buff*);
131 };
132 
133 struct pneigh_entry
134 {
135 	struct pneigh_entry	*next;
136 #ifdef CONFIG_NET_NS
137 	struct net		*net;
138 #endif
139 	struct net_device	*dev;
140 	u8			flags;
141 	u8			key[0];
142 };
143 
144 /*
145  *	neighbour table manipulation
146  */
147 
148 
149 struct neigh_table
150 {
151 	struct neigh_table	*next;
152 	int			family;
153 	int			entry_size;
154 	int			key_len;
155 	__u32			(*hash)(const void *pkey, const struct net_device *);
156 	int			(*constructor)(struct neighbour *);
157 	int			(*pconstructor)(struct pneigh_entry *);
158 	void			(*pdestructor)(struct pneigh_entry *);
159 	void			(*proxy_redo)(struct sk_buff *skb);
160 	char			*id;
161 	struct neigh_parms	parms;
162 	/* HACK. gc_* shoul follow parms without a gap! */
163 	int			gc_interval;
164 	int			gc_thresh1;
165 	int			gc_thresh2;
166 	int			gc_thresh3;
167 	unsigned long		last_flush;
168 	struct timer_list 	gc_timer;
169 	struct timer_list 	proxy_timer;
170 	struct sk_buff_head	proxy_queue;
171 	atomic_t		entries;
172 	rwlock_t		lock;
173 	unsigned long		last_rand;
174 	struct kmem_cache		*kmem_cachep;
175 	struct neigh_statistics	*stats;
176 	struct neighbour	**hash_buckets;
177 	unsigned int		hash_mask;
178 	__u32			hash_rnd;
179 	unsigned int		hash_chain_gc;
180 	struct pneigh_entry	**phash_buckets;
181 #ifdef CONFIG_PROC_FS
182 	struct proc_dir_entry	*pde;
183 #endif
184 };
185 
186 /* flags for neigh_update() */
187 #define NEIGH_UPDATE_F_OVERRIDE			0x00000001
188 #define NEIGH_UPDATE_F_WEAK_OVERRIDE		0x00000002
189 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER	0x00000004
190 #define NEIGH_UPDATE_F_ISROUTER			0x40000000
191 #define NEIGH_UPDATE_F_ADMIN			0x80000000
192 
193 extern void			neigh_table_init(struct neigh_table *tbl);
194 extern void			neigh_table_init_no_netlink(struct neigh_table *tbl);
195 extern int			neigh_table_clear(struct neigh_table *tbl);
196 extern struct neighbour *	neigh_lookup(struct neigh_table *tbl,
197 					     const void *pkey,
198 					     struct net_device *dev);
199 extern struct neighbour *	neigh_lookup_nodev(struct neigh_table *tbl,
200 						   struct net *net,
201 						   const void *pkey);
202 extern struct neighbour *	neigh_create(struct neigh_table *tbl,
203 					     const void *pkey,
204 					     struct net_device *dev);
205 extern void			neigh_destroy(struct neighbour *neigh);
206 extern int			__neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
207 extern int			neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
208 					     u32 flags);
209 extern void			neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
210 extern int			neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
211 extern int			neigh_resolve_output(struct sk_buff *skb);
212 extern int			neigh_connected_output(struct sk_buff *skb);
213 extern int			neigh_compat_output(struct sk_buff *skb);
214 extern struct neighbour 	*neigh_event_ns(struct neigh_table *tbl,
215 						u8 *lladdr, void *saddr,
216 						struct net_device *dev);
217 
218 extern struct neigh_parms	*neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
219 extern void			neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
220 
221 static inline
222 struct net			*neigh_parms_net(const struct neigh_parms *parms)
223 {
224 #ifdef CONFIG_NET_NS
225 	return parms->net;
226 #else
227 	return &init_net;
228 #endif
229 }
230 
231 extern unsigned long		neigh_rand_reach_time(unsigned long base);
232 
233 extern void			pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
234 					       struct sk_buff *skb);
235 extern struct pneigh_entry	*pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
236 extern struct pneigh_entry	*__pneigh_lookup(struct neigh_table *tbl,
237 						 struct net *net,
238 						 const void *key,
239 						 struct net_device *dev);
240 extern int			pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
241 
242 static inline
243 struct net			*pneigh_net(const struct pneigh_entry *pneigh)
244 {
245 #ifdef CONFIG_NET_NS
246 	return pneigh->net;
247 #else
248 	return &init_net;
249 #endif
250 }
251 
252 extern void neigh_app_ns(struct neighbour *n);
253 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
254 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
255 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
256 
257 struct neigh_seq_state {
258 	struct seq_net_private p;
259 	struct neigh_table *tbl;
260 	void *(*neigh_sub_iter)(struct neigh_seq_state *state,
261 				struct neighbour *n, loff_t *pos);
262 	unsigned int bucket;
263 	unsigned int flags;
264 #define NEIGH_SEQ_NEIGH_ONLY	0x00000001
265 #define NEIGH_SEQ_IS_PNEIGH	0x00000002
266 #define NEIGH_SEQ_SKIP_NOARP	0x00000004
267 };
268 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
269 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
270 extern void neigh_seq_stop(struct seq_file *, void *);
271 
272 extern int			neigh_sysctl_register(struct net_device *dev,
273 						      struct neigh_parms *p,
274 						      int p_id, int pdev_id,
275 						      char *p_name,
276 						      proc_handler *proc_handler,
277 						      ctl_handler *strategy);
278 extern void			neigh_sysctl_unregister(struct neigh_parms *p);
279 
280 static inline void __neigh_parms_put(struct neigh_parms *parms)
281 {
282 	atomic_dec(&parms->refcnt);
283 }
284 
285 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
286 {
287 	atomic_inc(&parms->refcnt);
288 	return parms;
289 }
290 
291 /*
292  *	Neighbour references
293  */
294 
295 static inline void neigh_release(struct neighbour *neigh)
296 {
297 	if (atomic_dec_and_test(&neigh->refcnt))
298 		neigh_destroy(neigh);
299 }
300 
301 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
302 {
303 	if (neigh)
304 		atomic_inc(&neigh->refcnt);
305 	return neigh;
306 }
307 
308 #define neigh_hold(n)	atomic_inc(&(n)->refcnt)
309 
310 static inline void neigh_confirm(struct neighbour *neigh)
311 {
312 	if (neigh)
313 		neigh->confirmed = jiffies;
314 }
315 
316 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
317 {
318 	neigh->used = jiffies;
319 	if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
320 		return __neigh_event_send(neigh, skb);
321 	return 0;
322 }
323 
324 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
325 {
326 	unsigned seq;
327 	int hh_len;
328 
329 	do {
330 		int hh_alen;
331 
332 		seq = read_seqbegin(&hh->hh_lock);
333 		hh_len = hh->hh_len;
334 		hh_alen = HH_DATA_ALIGN(hh_len);
335 		memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
336 	} while (read_seqretry(&hh->hh_lock, seq));
337 
338 	skb_push(skb, hh_len);
339 	return hh->hh_output(skb);
340 }
341 
342 static inline struct neighbour *
343 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
344 {
345 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
346 
347 	if (n || !creat)
348 		return n;
349 
350 	n = neigh_create(tbl, pkey, dev);
351 	return IS_ERR(n) ? NULL : n;
352 }
353 
354 static inline struct neighbour *
355 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
356   struct net_device *dev)
357 {
358 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
359 
360 	if (n)
361 		return n;
362 
363 	return neigh_create(tbl, pkey, dev);
364 }
365 
366 struct neighbour_cb {
367 	unsigned long sched_next;
368 	unsigned int flags;
369 };
370 
371 #define LOCALLY_ENQUEUED 0x1
372 
373 #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)
374 
375 #endif
376