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 __rcu *next;
95 struct neigh_table *tbl;
96 struct neigh_parms *parms;
97 unsigned long confirmed;
98 unsigned long updated;
99 rwlock_t lock;
100 atomic_t refcnt;
101 struct sk_buff_head arp_queue;
102 struct timer_list timer;
103 unsigned long used;
104 atomic_t probes;
105 __u8 flags;
106 __u8 nud_state;
107 __u8 type;
108 __u8 dead;
109 seqlock_t ha_lock;
110 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
111 struct hh_cache *hh;
112 int (*output)(struct sk_buff *skb);
113 const struct neigh_ops *ops;
114 struct rcu_head rcu;
115 struct net_device *dev;
116 u8 primary_key[0];
117 };
118
119 struct neigh_ops {
120 int family;
121 void (*solicit)(struct neighbour *, struct sk_buff*);
122 void (*error_report)(struct neighbour *, struct sk_buff*);
123 int (*output)(struct sk_buff*);
124 int (*connected_output)(struct sk_buff*);
125 int (*hh_output)(struct sk_buff*);
126 int (*queue_xmit)(struct sk_buff*);
127 };
128
129 struct pneigh_entry {
130 struct pneigh_entry *next;
131 #ifdef CONFIG_NET_NS
132 struct net *net;
133 #endif
134 struct net_device *dev;
135 u8 flags;
136 u8 key[0];
137 };
138
139 /*
140 * neighbour table manipulation
141 */
142
143 struct neigh_hash_table {
144 struct neighbour __rcu **hash_buckets;
145 unsigned int hash_mask;
146 __u32 hash_rnd;
147 struct rcu_head rcu;
148 };
149
150
151 struct neigh_table {
152 struct neigh_table *next;
153 int family;
154 int entry_size;
155 int key_len;
156 __u32 (*hash)(const void *pkey,
157 const struct net_device *dev,
158 __u32 hash_rnd);
159 int (*constructor)(struct neighbour *);
160 int (*pconstructor)(struct pneigh_entry *);
161 void (*pdestructor)(struct pneigh_entry *);
162 void (*proxy_redo)(struct sk_buff *skb);
163 char *id;
164 struct neigh_parms parms;
165 /* HACK. gc_* should follow parms without a gap! */
166 int gc_interval;
167 int gc_thresh1;
168 int gc_thresh2;
169 int gc_thresh3;
170 unsigned long last_flush;
171 struct delayed_work gc_work;
172 struct timer_list proxy_timer;
173 struct sk_buff_head proxy_queue;
174 atomic_t entries;
175 rwlock_t lock;
176 unsigned long last_rand;
177 struct kmem_cache *kmem_cachep;
178 struct neigh_statistics __percpu *stats;
179 struct neigh_hash_table __rcu *nht;
180 struct pneigh_entry **phash_buckets;
181 };
182
183 /* flags for neigh_update() */
184 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001
185 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002
186 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004
187 #define NEIGH_UPDATE_F_ISROUTER 0x40000000
188 #define NEIGH_UPDATE_F_ADMIN 0x80000000
189
190 extern void neigh_table_init(struct neigh_table *tbl);
191 extern void neigh_table_init_no_netlink(struct neigh_table *tbl);
192 extern int neigh_table_clear(struct neigh_table *tbl);
193 extern struct neighbour * neigh_lookup(struct neigh_table *tbl,
194 const void *pkey,
195 struct net_device *dev);
196 extern struct neighbour * neigh_lookup_nodev(struct neigh_table *tbl,
197 struct net *net,
198 const void *pkey);
199 extern struct neighbour * neigh_create(struct neigh_table *tbl,
200 const void *pkey,
201 struct net_device *dev);
202 extern void neigh_destroy(struct neighbour *neigh);
203 extern int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
204 extern int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
205 u32 flags);
206 extern void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
207 extern int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
208 extern int neigh_resolve_output(struct sk_buff *skb);
209 extern int neigh_connected_output(struct sk_buff *skb);
210 extern int neigh_compat_output(struct sk_buff *skb);
211 extern struct neighbour *neigh_event_ns(struct neigh_table *tbl,
212 u8 *lladdr, void *saddr,
213 struct net_device *dev);
214
215 extern struct neigh_parms *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
216 extern void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
217
218 static inline
neigh_parms_net(const struct neigh_parms * parms)219 struct net *neigh_parms_net(const struct neigh_parms *parms)
220 {
221 return read_pnet(&parms->net);
222 }
223
224 extern unsigned long neigh_rand_reach_time(unsigned long base);
225
226 extern void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
227 struct sk_buff *skb);
228 extern struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
229 extern struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl,
230 struct net *net,
231 const void *key,
232 struct net_device *dev);
233 extern int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
234
235 static inline
pneigh_net(const struct pneigh_entry * pneigh)236 struct net *pneigh_net(const struct pneigh_entry *pneigh)
237 {
238 return read_pnet(&pneigh->net);
239 }
240
241 extern void neigh_app_ns(struct neighbour *n);
242 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
243 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
244 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
245
246 struct neigh_seq_state {
247 struct seq_net_private p;
248 struct neigh_table *tbl;
249 struct neigh_hash_table *nht;
250 void *(*neigh_sub_iter)(struct neigh_seq_state *state,
251 struct neighbour *n, loff_t *pos);
252 unsigned int bucket;
253 unsigned int flags;
254 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001
255 #define NEIGH_SEQ_IS_PNEIGH 0x00000002
256 #define NEIGH_SEQ_SKIP_NOARP 0x00000004
257 };
258 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
259 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
260 extern void neigh_seq_stop(struct seq_file *, void *);
261
262 extern int neigh_sysctl_register(struct net_device *dev,
263 struct neigh_parms *p,
264 char *p_name,
265 proc_handler *proc_handler);
266 extern void neigh_sysctl_unregister(struct neigh_parms *p);
267
__neigh_parms_put(struct neigh_parms * parms)268 static inline void __neigh_parms_put(struct neigh_parms *parms)
269 {
270 atomic_dec(&parms->refcnt);
271 }
272
neigh_parms_clone(struct neigh_parms * parms)273 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
274 {
275 atomic_inc(&parms->refcnt);
276 return parms;
277 }
278
279 /*
280 * Neighbour references
281 */
282
neigh_release(struct neighbour * neigh)283 static inline void neigh_release(struct neighbour *neigh)
284 {
285 if (atomic_dec_and_test(&neigh->refcnt))
286 neigh_destroy(neigh);
287 }
288
neigh_clone(struct neighbour * neigh)289 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
290 {
291 if (neigh)
292 atomic_inc(&neigh->refcnt);
293 return neigh;
294 }
295
296 #define neigh_hold(n) atomic_inc(&(n)->refcnt)
297
neigh_confirm(struct neighbour * neigh)298 static inline void neigh_confirm(struct neighbour *neigh)
299 {
300 if (neigh)
301 neigh->confirmed = jiffies;
302 }
303
neigh_event_send(struct neighbour * neigh,struct sk_buff * skb)304 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
305 {
306 unsigned long now = jiffies;
307
308 if (neigh->used != now)
309 neigh->used = now;
310 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
311 return __neigh_event_send(neigh, skb);
312 return 0;
313 }
314
315 #ifdef CONFIG_BRIDGE_NETFILTER
neigh_hh_bridge(struct hh_cache * hh,struct sk_buff * skb)316 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
317 {
318 unsigned seq, hh_alen;
319
320 do {
321 seq = read_seqbegin(&hh->hh_lock);
322 hh_alen = HH_DATA_ALIGN(ETH_HLEN);
323 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
324 } while (read_seqretry(&hh->hh_lock, seq));
325 return 0;
326 }
327 #endif
328
neigh_hh_output(struct hh_cache * hh,struct sk_buff * skb)329 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
330 {
331 unsigned seq;
332 int hh_len;
333
334 do {
335 int hh_alen;
336
337 seq = read_seqbegin(&hh->hh_lock);
338 hh_len = hh->hh_len;
339 hh_alen = HH_DATA_ALIGN(hh_len);
340 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
341 } while (read_seqretry(&hh->hh_lock, seq));
342
343 skb_push(skb, hh_len);
344 return hh->hh_output(skb);
345 }
346
347 static inline struct neighbour *
__neigh_lookup(struct neigh_table * tbl,const void * pkey,struct net_device * dev,int creat)348 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
349 {
350 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
351
352 if (n || !creat)
353 return n;
354
355 n = neigh_create(tbl, pkey, dev);
356 return IS_ERR(n) ? NULL : n;
357 }
358
359 static inline struct neighbour *
__neigh_lookup_errno(struct neigh_table * tbl,const void * pkey,struct net_device * dev)360 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
361 struct net_device *dev)
362 {
363 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
364
365 if (n)
366 return n;
367
368 return neigh_create(tbl, pkey, dev);
369 }
370
371 struct neighbour_cb {
372 unsigned long sched_next;
373 unsigned int flags;
374 };
375
376 #define LOCALLY_ENQUEUED 0x1
377
378 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
379
neigh_ha_snapshot(char * dst,const struct neighbour * n,const struct net_device * dev)380 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
381 const struct net_device *dev)
382 {
383 unsigned int seq;
384
385 do {
386 seq = read_seqbegin(&n->ha_lock);
387 memcpy(dst, n->ha, dev->addr_len);
388 } while (read_seqretry(&n->ha_lock, seq));
389 }
390 #endif
391