xref: /openbmc/linux/include/net/neighbour.h (revision 643d1f7f)
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 	struct net *net;
42 	struct net_device *dev;
43 	struct neigh_parms *next;
44 	int	(*neigh_setup)(struct neighbour *);
45 	void	(*neigh_cleanup)(struct neighbour *);
46 	struct neigh_table *tbl;
47 
48 	void	*sysctl_table;
49 
50 	int dead;
51 	atomic_t refcnt;
52 	struct rcu_head rcu_head;
53 
54 	int	base_reachable_time;
55 	int	retrans_time;
56 	int	gc_staletime;
57 	int	reachable_time;
58 	int	delay_probe_time;
59 
60 	int	queue_len;
61 	int	ucast_probes;
62 	int	app_probes;
63 	int	mcast_probes;
64 	int	anycast_delay;
65 	int	proxy_delay;
66 	int	proxy_qlen;
67 	int	locktime;
68 };
69 
70 struct neigh_statistics
71 {
72 	unsigned long allocs;		/* number of allocated neighs */
73 	unsigned long destroys;		/* number of destroyed neighs */
74 	unsigned long hash_grows;	/* number of hash resizes */
75 
76 	unsigned long res_failed;	/* nomber of failed resolutions */
77 
78 	unsigned long lookups;		/* number of lookups */
79 	unsigned long hits;		/* number of hits (among lookups) */
80 
81 	unsigned long rcv_probes_mcast;	/* number of received mcast ipv6 */
82 	unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
83 
84 	unsigned long periodic_gc_runs;	/* number of periodic GC runs */
85 	unsigned long forced_gc_runs;	/* number of forced GC runs */
86 };
87 
88 #define NEIGH_CACHE_STAT_INC(tbl, field)				\
89 	do {								\
90 		preempt_disable();					\
91 		(per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
92 		preempt_enable();					\
93 	} while (0)
94 
95 struct neighbour
96 {
97 	struct neighbour	*next;
98 	struct neigh_table	*tbl;
99 	struct neigh_parms	*parms;
100 	struct net_device		*dev;
101 	unsigned long		used;
102 	unsigned long		confirmed;
103 	unsigned long		updated;
104 	__u8			flags;
105 	__u8			nud_state;
106 	__u8			type;
107 	__u8			dead;
108 	atomic_t		probes;
109 	rwlock_t		lock;
110 	unsigned char		ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
111 	struct hh_cache		*hh;
112 	atomic_t		refcnt;
113 	int			(*output)(struct sk_buff *skb);
114 	struct sk_buff_head	arp_queue;
115 	struct timer_list	timer;
116 	struct neigh_ops	*ops;
117 	u8			primary_key[0];
118 };
119 
120 struct neigh_ops
121 {
122 	int			family;
123 	void			(*solicit)(struct neighbour *, struct sk_buff*);
124 	void			(*error_report)(struct neighbour *, struct sk_buff*);
125 	int			(*output)(struct sk_buff*);
126 	int			(*connected_output)(struct sk_buff*);
127 	int			(*hh_output)(struct sk_buff*);
128 	int			(*queue_xmit)(struct sk_buff*);
129 };
130 
131 struct pneigh_entry
132 {
133 	struct pneigh_entry	*next;
134 	struct net		*net;
135 	struct net_device	*dev;
136 	u8			flags;
137 	u8			key[0];
138 };
139 
140 /*
141  *	neighbour table manipulation
142  */
143 
144 
145 struct neigh_table
146 {
147 	struct neigh_table	*next;
148 	int			family;
149 	int			entry_size;
150 	int			key_len;
151 	__u32			(*hash)(const void *pkey, const struct net_device *);
152 	int			(*constructor)(struct neighbour *);
153 	int			(*pconstructor)(struct pneigh_entry *);
154 	void			(*pdestructor)(struct pneigh_entry *);
155 	void			(*proxy_redo)(struct sk_buff *skb);
156 	char			*id;
157 	struct neigh_parms	parms;
158 	/* HACK. gc_* shoul follow parms without a gap! */
159 	int			gc_interval;
160 	int			gc_thresh1;
161 	int			gc_thresh2;
162 	int			gc_thresh3;
163 	unsigned long		last_flush;
164 	struct timer_list 	gc_timer;
165 	struct timer_list 	proxy_timer;
166 	struct sk_buff_head	proxy_queue;
167 	atomic_t		entries;
168 	rwlock_t		lock;
169 	unsigned long		last_rand;
170 	struct kmem_cache		*kmem_cachep;
171 	struct neigh_statistics	*stats;
172 	struct neighbour	**hash_buckets;
173 	unsigned int		hash_mask;
174 	__u32			hash_rnd;
175 	unsigned int		hash_chain_gc;
176 	struct pneigh_entry	**phash_buckets;
177 #ifdef CONFIG_PROC_FS
178 	struct proc_dir_entry	*pde;
179 #endif
180 };
181 
182 /* flags for neigh_update() */
183 #define NEIGH_UPDATE_F_OVERRIDE			0x00000001
184 #define NEIGH_UPDATE_F_WEAK_OVERRIDE		0x00000002
185 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER	0x00000004
186 #define NEIGH_UPDATE_F_ISROUTER			0x40000000
187 #define NEIGH_UPDATE_F_ADMIN			0x80000000
188 
189 extern void			neigh_table_init(struct neigh_table *tbl);
190 extern void			neigh_table_init_no_netlink(struct neigh_table *tbl);
191 extern int			neigh_table_clear(struct neigh_table *tbl);
192 extern struct neighbour *	neigh_lookup(struct neigh_table *tbl,
193 					     const void *pkey,
194 					     struct net_device *dev);
195 extern struct neighbour *	neigh_lookup_nodev(struct neigh_table *tbl,
196 						   struct net *net,
197 						   const void *pkey);
198 extern struct neighbour *	neigh_create(struct neigh_table *tbl,
199 					     const void *pkey,
200 					     struct net_device *dev);
201 extern void			neigh_destroy(struct neighbour *neigh);
202 extern int			__neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
203 extern int			neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
204 					     u32 flags);
205 extern void			neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
206 extern int			neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
207 extern int			neigh_resolve_output(struct sk_buff *skb);
208 extern int			neigh_connected_output(struct sk_buff *skb);
209 extern int			neigh_compat_output(struct sk_buff *skb);
210 extern struct neighbour 	*neigh_event_ns(struct neigh_table *tbl,
211 						u8 *lladdr, void *saddr,
212 						struct net_device *dev);
213 
214 extern struct neigh_parms	*neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
215 extern void			neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
216 extern unsigned long		neigh_rand_reach_time(unsigned long base);
217 
218 extern void			pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
219 					       struct sk_buff *skb);
220 extern struct pneigh_entry	*pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
221 extern int			pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
222 
223 extern void neigh_app_ns(struct neighbour *n);
224 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
225 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
226 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
227 
228 struct neigh_seq_state {
229 	struct seq_net_private p;
230 	struct neigh_table *tbl;
231 	void *(*neigh_sub_iter)(struct neigh_seq_state *state,
232 				struct neighbour *n, loff_t *pos);
233 	unsigned int bucket;
234 	unsigned int flags;
235 #define NEIGH_SEQ_NEIGH_ONLY	0x00000001
236 #define NEIGH_SEQ_IS_PNEIGH	0x00000002
237 #define NEIGH_SEQ_SKIP_NOARP	0x00000004
238 };
239 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
240 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
241 extern void neigh_seq_stop(struct seq_file *, void *);
242 
243 extern int			neigh_sysctl_register(struct net_device *dev,
244 						      struct neigh_parms *p,
245 						      int p_id, int pdev_id,
246 						      char *p_name,
247 						      proc_handler *proc_handler,
248 						      ctl_handler *strategy);
249 extern void			neigh_sysctl_unregister(struct neigh_parms *p);
250 
251 static inline void __neigh_parms_put(struct neigh_parms *parms)
252 {
253 	atomic_dec(&parms->refcnt);
254 }
255 
256 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
257 {
258 	atomic_inc(&parms->refcnt);
259 	return parms;
260 }
261 
262 /*
263  *	Neighbour references
264  */
265 
266 static inline void neigh_release(struct neighbour *neigh)
267 {
268 	if (atomic_dec_and_test(&neigh->refcnt))
269 		neigh_destroy(neigh);
270 }
271 
272 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
273 {
274 	if (neigh)
275 		atomic_inc(&neigh->refcnt);
276 	return neigh;
277 }
278 
279 #define neigh_hold(n)	atomic_inc(&(n)->refcnt)
280 
281 static inline void neigh_confirm(struct neighbour *neigh)
282 {
283 	if (neigh)
284 		neigh->confirmed = jiffies;
285 }
286 
287 static inline int neigh_is_connected(struct neighbour *neigh)
288 {
289 	return neigh->nud_state&NUD_CONNECTED;
290 }
291 
292 
293 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
294 {
295 	neigh->used = jiffies;
296 	if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
297 		return __neigh_event_send(neigh, skb);
298 	return 0;
299 }
300 
301 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
302 {
303 	unsigned seq;
304 	int hh_len;
305 
306 	do {
307 		int hh_alen;
308 
309 		seq = read_seqbegin(&hh->hh_lock);
310 		hh_len = hh->hh_len;
311 		hh_alen = HH_DATA_ALIGN(hh_len);
312 		memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
313 	} while (read_seqretry(&hh->hh_lock, seq));
314 
315 	skb_push(skb, hh_len);
316 	return hh->hh_output(skb);
317 }
318 
319 static inline struct neighbour *
320 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
321 {
322 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
323 
324 	if (n || !creat)
325 		return n;
326 
327 	n = neigh_create(tbl, pkey, dev);
328 	return IS_ERR(n) ? NULL : n;
329 }
330 
331 static inline struct neighbour *
332 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
333   struct net_device *dev)
334 {
335 	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
336 
337 	if (n)
338 		return n;
339 
340 	return neigh_create(tbl, pkey, dev);
341 }
342 
343 struct neighbour_cb {
344 	unsigned long sched_next;
345 	unsigned int flags;
346 };
347 
348 #define LOCALLY_ENQUEUED 0x1
349 
350 #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)
351 
352 #endif
353