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[NEIGH]: Make /proc/net/arp opening consistent with seq_net_open semantics
[linux-2.6] / include / net / neighbour.h
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 #define NUD_IN_TIMER    (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
30 #define NUD_VALID       (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
31 #define NUD_CONNECTED   (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
32
33 struct neighbour;
34
35 struct neigh_parms
36 {
37         struct net *net;
38         struct net_device *dev;
39         struct neigh_parms *next;
40         int     (*neigh_setup)(struct neighbour *);
41         void    (*neigh_cleanup)(struct neighbour *);
42         struct neigh_table *tbl;
43
44         void    *sysctl_table;
45
46         int dead;
47         atomic_t refcnt;
48         struct rcu_head rcu_head;
49
50         int     base_reachable_time;
51         int     retrans_time;
52         int     gc_staletime;
53         int     reachable_time;
54         int     delay_probe_time;
55
56         int     queue_len;
57         int     ucast_probes;
58         int     app_probes;
59         int     mcast_probes;
60         int     anycast_delay;
61         int     proxy_delay;
62         int     proxy_qlen;
63         int     locktime;
64 };
65
66 struct neigh_statistics
67 {
68         unsigned long allocs;           /* number of allocated neighs */
69         unsigned long destroys;         /* number of destroyed neighs */
70         unsigned long hash_grows;       /* number of hash resizes */
71
72         unsigned long res_failed;       /* nomber of failed resolutions */
73
74         unsigned long lookups;          /* number of lookups */
75         unsigned long hits;             /* number of hits (among lookups) */
76
77         unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
78         unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
79
80         unsigned long periodic_gc_runs; /* number of periodic GC runs */
81         unsigned long forced_gc_runs;   /* number of forced GC runs */
82 };
83
84 #define NEIGH_CACHE_STAT_INC(tbl, field)                                \
85         do {                                                            \
86                 preempt_disable();                                      \
87                 (per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
88                 preempt_enable();                                       \
89         } while (0)
90
91 struct neighbour
92 {
93         struct neighbour        *next;
94         struct neigh_table      *tbl;
95         struct neigh_parms      *parms;
96         struct net_device               *dev;
97         unsigned long           used;
98         unsigned long           confirmed;
99         unsigned long           updated;
100         __u8                    flags;
101         __u8                    nud_state;
102         __u8                    type;
103         __u8                    dead;
104         atomic_t                probes;
105         rwlock_t                lock;
106         unsigned char           ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
107         struct hh_cache         *hh;
108         atomic_t                refcnt;
109         int                     (*output)(struct sk_buff *skb);
110         struct sk_buff_head     arp_queue;
111         struct timer_list       timer;
112         struct neigh_ops        *ops;
113         u8                      primary_key[0];
114 };
115
116 struct neigh_ops
117 {
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 {
129         struct pneigh_entry     *next;
130         struct net              *net;
131         struct net_device       *dev;
132         u8                      flags;
133         u8                      key[0];
134 };
135
136 /*
137  *      neighbour table manipulation
138  */
139
140
141 struct neigh_table
142 {
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 timer_list       gc_timer;
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         unsigned int            hash_chain_gc;
172         struct pneigh_entry     **phash_buckets;
173 #ifdef CONFIG_PROC_FS
174         struct proc_dir_entry   *pde;
175 #endif
176 };
177
178 /* flags for neigh_update() */
179 #define NEIGH_UPDATE_F_OVERRIDE                 0x00000001
180 #define NEIGH_UPDATE_F_WEAK_OVERRIDE            0x00000002
181 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        0x00000004
182 #define NEIGH_UPDATE_F_ISROUTER                 0x40000000
183 #define NEIGH_UPDATE_F_ADMIN                    0x80000000
184
185 extern void                     neigh_table_init(struct neigh_table *tbl);
186 extern void                     neigh_table_init_no_netlink(struct neigh_table *tbl);
187 extern int                      neigh_table_clear(struct neigh_table *tbl);
188 extern struct neighbour *       neigh_lookup(struct neigh_table *tbl,
189                                              const void *pkey,
190                                              struct net_device *dev);
191 extern struct neighbour *       neigh_lookup_nodev(struct neigh_table *tbl,
192                                                    struct net *net,
193                                                    const void *pkey);
194 extern struct neighbour *       neigh_create(struct neigh_table *tbl,
195                                              const void *pkey,
196                                              struct net_device *dev);
197 extern void                     neigh_destroy(struct neighbour *neigh);
198 extern int                      __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
199 extern int                      neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 
200                                              u32 flags);
201 extern void                     neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
202 extern int                      neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
203 extern int                      neigh_resolve_output(struct sk_buff *skb);
204 extern int                      neigh_connected_output(struct sk_buff *skb);
205 extern int                      neigh_compat_output(struct sk_buff *skb);
206 extern struct neighbour         *neigh_event_ns(struct neigh_table *tbl,
207                                                 u8 *lladdr, void *saddr,
208                                                 struct net_device *dev);
209
210 extern struct neigh_parms       *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
211 extern void                     neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
212 extern void                     neigh_parms_destroy(struct neigh_parms *parms);
213 extern unsigned long            neigh_rand_reach_time(unsigned long base);
214
215 extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
216                                                struct sk_buff *skb);
217 extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
218 extern int                      pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
219
220 extern void neigh_app_ns(struct neighbour *n);
221 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
222 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
223 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
224
225 struct neigh_seq_state {
226         struct seq_net_private p;
227         struct neigh_table *tbl;
228         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
229                                 struct neighbour *n, loff_t *pos);
230         unsigned int bucket;
231         unsigned int flags;
232 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
233 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
234 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
235 };
236 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
237 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
238 extern void neigh_seq_stop(struct seq_file *, void *);
239
240 extern int                      neigh_sysctl_register(struct net_device *dev, 
241                                                       struct neigh_parms *p,
242                                                       int p_id, int pdev_id,
243                                                       char *p_name,
244                                                       proc_handler *proc_handler,
245                                                       ctl_handler *strategy);
246 extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
247
248 static inline void __neigh_parms_put(struct neigh_parms *parms)
249 {
250         atomic_dec(&parms->refcnt);
251 }
252
253 static inline void neigh_parms_put(struct neigh_parms *parms)
254 {
255         if (atomic_dec_and_test(&parms->refcnt))
256                 neigh_parms_destroy(parms);
257 }
258
259 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
260 {
261         atomic_inc(&parms->refcnt);
262         return parms;
263 }
264
265 /*
266  *      Neighbour references
267  */
268
269 static inline void neigh_release(struct neighbour *neigh)
270 {
271         if (atomic_dec_and_test(&neigh->refcnt))
272                 neigh_destroy(neigh);
273 }
274
275 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
276 {
277         if (neigh)
278                 atomic_inc(&neigh->refcnt);
279         return neigh;
280 }
281
282 #define neigh_hold(n)   atomic_inc(&(n)->refcnt)
283
284 static inline void neigh_confirm(struct neighbour *neigh)
285 {
286         if (neigh)
287                 neigh->confirmed = jiffies;
288 }
289
290 static inline int neigh_is_connected(struct neighbour *neigh)
291 {
292         return neigh->nud_state&NUD_CONNECTED;
293 }
294
295
296 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
297 {
298         neigh->used = jiffies;
299         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
300                 return __neigh_event_send(neigh, skb);
301         return 0;
302 }
303
304 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
305 {
306         unsigned seq;
307         int hh_len;
308
309         do {
310                 int hh_alen;
311
312                 seq = read_seqbegin(&hh->hh_lock);
313                 hh_len = hh->hh_len;
314                 hh_alen = HH_DATA_ALIGN(hh_len);
315                 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
316         } while (read_seqretry(&hh->hh_lock, seq));
317
318         skb_push(skb, hh_len);
319         return hh->hh_output(skb);
320 }
321
322 static inline struct neighbour *
323 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
324 {
325         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
326
327         if (n || !creat)
328                 return n;
329
330         n = neigh_create(tbl, pkey, dev);
331         return IS_ERR(n) ? NULL : n;
332 }
333
334 static inline struct neighbour *
335 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
336   struct net_device *dev)
337 {
338         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
339
340         if (n)
341                 return n;
342
343         return neigh_create(tbl, pkey, dev);
344 }
345
346 struct neighbour_cb {
347         unsigned long sched_next;
348         unsigned int flags;
349 };
350
351 #define LOCALLY_ENQUEUED 0x1
352
353 #define NEIGH_CB(skb)   ((struct neighbour_cb *)(skb)->cb)
354
355 #endif