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 <linux/atomic.h>
20 #include <linux/netdevice.h>
21 #include <linux/skbuff.h>
22 #include <linux/rcupdate.h>
23 #include <linux/seq_file.h>
24 #include <linux/bitmap.h>
25
26 #include <linux/err.h>
27 #include <linux/sysctl.h>
28 #include <linux/workqueue.h>
29 #include <net/rtnetlink.h>
30
31 /*
32 * NUD stands for "neighbor unreachability detection"
33 */
34
35 #define NUD_IN_TIMER (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
36 #define NUD_VALID (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
37 #define NUD_CONNECTED (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
38
39 struct neighbour;
40
41 enum {
42 NEIGH_VAR_MCAST_PROBES,
43 NEIGH_VAR_UCAST_PROBES,
44 NEIGH_VAR_APP_PROBES,
45 NEIGH_VAR_RETRANS_TIME,
46 NEIGH_VAR_BASE_REACHABLE_TIME,
47 NEIGH_VAR_DELAY_PROBE_TIME,
48 NEIGH_VAR_GC_STALETIME,
49 NEIGH_VAR_QUEUE_LEN_BYTES,
50 NEIGH_VAR_PROXY_QLEN,
51 NEIGH_VAR_ANYCAST_DELAY,
52 NEIGH_VAR_PROXY_DELAY,
53 NEIGH_VAR_LOCKTIME,
54 #define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1)
55 /* Following are used as a second way to access one of the above */
56 NEIGH_VAR_QUEUE_LEN, /* same data as NEIGH_VAR_QUEUE_LEN_BYTES */
57 NEIGH_VAR_RETRANS_TIME_MS, /* same data as NEIGH_VAR_RETRANS_TIME */
58 NEIGH_VAR_BASE_REACHABLE_TIME_MS, /* same data as NEIGH_VAR_BASE_REACHABLE_TIME */
59 /* Following are used by "default" only */
60 NEIGH_VAR_GC_INTERVAL,
61 NEIGH_VAR_GC_THRESH1,
62 NEIGH_VAR_GC_THRESH2,
63 NEIGH_VAR_GC_THRESH3,
64 NEIGH_VAR_MAX
65 };
66
67 struct neigh_parms {
68 #ifdef CONFIG_NET_NS
69 struct net *net;
70 #endif
71 struct net_device *dev;
72 struct neigh_parms *next;
73 int (*neigh_setup)(struct neighbour *);
74 void (*neigh_cleanup)(struct neighbour *);
75 struct neigh_table *tbl;
76
77 void *sysctl_table;
78
79 int dead;
80 atomic_t refcnt;
81 struct rcu_head rcu_head;
82
83 int reachable_time;
84 int data[NEIGH_VAR_DATA_MAX];
85 DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX);
86 };
87
neigh_var_set(struct neigh_parms * p,int index,int val)88 static inline void neigh_var_set(struct neigh_parms *p, int index, int val)
89 {
90 set_bit(index, p->data_state);
91 p->data[index] = val;
92 }
93
94 #define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr])
95
96 /* In ndo_neigh_setup, NEIGH_VAR_INIT should be used.
97 * In other cases, NEIGH_VAR_SET should be used.
98 */
99 #define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val)
100 #define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val)
101
neigh_parms_data_state_setall(struct neigh_parms * p)102 static inline void neigh_parms_data_state_setall(struct neigh_parms *p)
103 {
104 bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX);
105 }
106
neigh_parms_data_state_cleanall(struct neigh_parms * p)107 static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p)
108 {
109 bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX);
110 }
111
112 struct neigh_statistics {
113 unsigned long allocs; /* number of allocated neighs */
114 unsigned long destroys; /* number of destroyed neighs */
115 unsigned long hash_grows; /* number of hash resizes */
116
117 unsigned long res_failed; /* number of failed resolutions */
118
119 unsigned long lookups; /* number of lookups */
120 unsigned long hits; /* number of hits (among lookups) */
121
122 unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
123 unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
124
125 unsigned long periodic_gc_runs; /* number of periodic GC runs */
126 unsigned long forced_gc_runs; /* number of forced GC runs */
127
128 unsigned long unres_discards; /* number of unresolved drops */
129 };
130
131 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
132
133 struct neighbour {
134 struct neighbour __rcu *next;
135 struct neigh_table *tbl;
136 struct neigh_parms *parms;
137 unsigned long confirmed;
138 unsigned long updated;
139 rwlock_t lock;
140 atomic_t refcnt;
141 struct sk_buff_head arp_queue;
142 unsigned int arp_queue_len_bytes;
143 struct timer_list timer;
144 unsigned long used;
145 atomic_t probes;
146 __u8 flags;
147 __u8 nud_state;
148 __u8 type;
149 __u8 dead;
150 seqlock_t ha_lock;
151 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
152 struct hh_cache hh;
153 int (*output)(struct neighbour *, struct sk_buff *);
154 const struct neigh_ops *ops;
155 struct rcu_head rcu;
156 struct net_device *dev;
157 u8 primary_key[0];
158 };
159
160 struct neigh_ops {
161 int family;
162 void (*solicit)(struct neighbour *, struct sk_buff *);
163 void (*error_report)(struct neighbour *, struct sk_buff *);
164 int (*output)(struct neighbour *, struct sk_buff *);
165 int (*connected_output)(struct neighbour *, struct sk_buff *);
166 };
167
168 struct pneigh_entry {
169 struct pneigh_entry *next;
170 #ifdef CONFIG_NET_NS
171 struct net *net;
172 #endif
173 struct net_device *dev;
174 u8 flags;
175 u8 key[0];
176 };
177
178 /*
179 * neighbour table manipulation
180 */
181
182 #define NEIGH_NUM_HASH_RND 4
183
184 struct neigh_hash_table {
185 struct neighbour __rcu **hash_buckets;
186 unsigned int hash_shift;
187 __u32 hash_rnd[NEIGH_NUM_HASH_RND];
188 struct rcu_head rcu;
189 };
190
191
192 struct neigh_table {
193 struct neigh_table *next;
194 int family;
195 int entry_size;
196 int key_len;
197 __u32 (*hash)(const void *pkey,
198 const struct net_device *dev,
199 __u32 *hash_rnd);
200 int (*constructor)(struct neighbour *);
201 int (*pconstructor)(struct pneigh_entry *);
202 void (*pdestructor)(struct pneigh_entry *);
203 void (*proxy_redo)(struct sk_buff *skb);
204 char *id;
205 struct neigh_parms parms;
206 int gc_interval;
207 int gc_thresh1;
208 int gc_thresh2;
209 int gc_thresh3;
210 unsigned long last_flush;
211 struct delayed_work gc_work;
212 struct timer_list proxy_timer;
213 struct sk_buff_head proxy_queue;
214 atomic_t entries;
215 rwlock_t lock;
216 unsigned long last_rand;
217 struct neigh_statistics __percpu *stats;
218 struct neigh_hash_table __rcu *nht;
219 struct pneigh_entry **phash_buckets;
220 };
221
neigh_parms_family(struct neigh_parms * p)222 static inline int neigh_parms_family(struct neigh_parms *p)
223 {
224 return p->tbl->family;
225 }
226
227 #define NEIGH_PRIV_ALIGN sizeof(long long)
228 #define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN)
229
neighbour_priv(const struct neighbour * n)230 static inline void *neighbour_priv(const struct neighbour *n)
231 {
232 return (char *)n + n->tbl->entry_size;
233 }
234
235 /* flags for neigh_update() */
236 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001
237 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002
238 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004
239 #define NEIGH_UPDATE_F_ISROUTER 0x40000000
240 #define NEIGH_UPDATE_F_ADMIN 0x80000000
241
242 void neigh_table_init(struct neigh_table *tbl);
243 int neigh_table_clear(struct neigh_table *tbl);
244 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
245 struct net_device *dev);
246 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
247 const void *pkey);
248 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
249 struct net_device *dev, bool want_ref);
neigh_create(struct neigh_table * tbl,const void * pkey,struct net_device * dev)250 static inline struct neighbour *neigh_create(struct neigh_table *tbl,
251 const void *pkey,
252 struct net_device *dev)
253 {
254 return __neigh_create(tbl, pkey, dev, true);
255 }
256 void neigh_destroy(struct neighbour *neigh);
257 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
258 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags);
259 void __neigh_set_probe_once(struct neighbour *neigh);
260 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
261 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
262 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
263 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
264 int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb);
265 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
266 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
267 u8 *lladdr, void *saddr,
268 struct net_device *dev);
269
270 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
271 struct neigh_table *tbl);
272 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
273
274 static inline
neigh_parms_net(const struct neigh_parms * parms)275 struct net *neigh_parms_net(const struct neigh_parms *parms)
276 {
277 return read_pnet(&parms->net);
278 }
279
280 unsigned long neigh_rand_reach_time(unsigned long base);
281
282 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
283 struct sk_buff *skb);
284 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
285 const void *key, struct net_device *dev,
286 int creat);
287 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
288 const void *key, struct net_device *dev);
289 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
290 struct net_device *dev);
291
pneigh_net(const struct pneigh_entry * pneigh)292 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
293 {
294 return read_pnet(&pneigh->net);
295 }
296
297 void neigh_app_ns(struct neighbour *n);
298 void neigh_for_each(struct neigh_table *tbl,
299 void (*cb)(struct neighbour *, void *), void *cookie);
300 void __neigh_for_each_release(struct neigh_table *tbl,
301 int (*cb)(struct neighbour *));
302 void pneigh_for_each(struct neigh_table *tbl,
303 void (*cb)(struct pneigh_entry *));
304
305 struct neigh_seq_state {
306 struct seq_net_private p;
307 struct neigh_table *tbl;
308 struct neigh_hash_table *nht;
309 void *(*neigh_sub_iter)(struct neigh_seq_state *state,
310 struct neighbour *n, loff_t *pos);
311 unsigned int bucket;
312 unsigned int flags;
313 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001
314 #define NEIGH_SEQ_IS_PNEIGH 0x00000002
315 #define NEIGH_SEQ_SKIP_NOARP 0x00000004
316 };
317 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
318 unsigned int);
319 void *neigh_seq_next(struct seq_file *, void *, loff_t *);
320 void neigh_seq_stop(struct seq_file *, void *);
321
322 int neigh_proc_dointvec(struct ctl_table *ctl, int write,
323 void __user *buffer, size_t *lenp, loff_t *ppos);
324 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
325 void __user *buffer,
326 size_t *lenp, loff_t *ppos);
327 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
328 void __user *buffer,
329 size_t *lenp, loff_t *ppos);
330
331 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
332 proc_handler *proc_handler);
333 void neigh_sysctl_unregister(struct neigh_parms *p);
334
__neigh_parms_put(struct neigh_parms * parms)335 static inline void __neigh_parms_put(struct neigh_parms *parms)
336 {
337 atomic_dec(&parms->refcnt);
338 }
339
neigh_parms_clone(struct neigh_parms * parms)340 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
341 {
342 atomic_inc(&parms->refcnt);
343 return parms;
344 }
345
346 /*
347 * Neighbour references
348 */
349
neigh_release(struct neighbour * neigh)350 static inline void neigh_release(struct neighbour *neigh)
351 {
352 if (atomic_dec_and_test(&neigh->refcnt))
353 neigh_destroy(neigh);
354 }
355
neigh_clone(struct neighbour * neigh)356 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
357 {
358 if (neigh)
359 atomic_inc(&neigh->refcnt);
360 return neigh;
361 }
362
363 #define neigh_hold(n) atomic_inc(&(n)->refcnt)
364
neigh_event_send(struct neighbour * neigh,struct sk_buff * skb)365 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
366 {
367 unsigned long now = jiffies;
368
369 if (neigh->used != now)
370 neigh->used = now;
371 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
372 return __neigh_event_send(neigh, skb);
373 return 0;
374 }
375
376 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
neigh_hh_bridge(struct hh_cache * hh,struct sk_buff * skb)377 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
378 {
379 unsigned int seq, hh_alen;
380
381 do {
382 seq = read_seqbegin(&hh->hh_lock);
383 hh_alen = HH_DATA_ALIGN(ETH_HLEN);
384 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
385 } while (read_seqretry(&hh->hh_lock, seq));
386 return 0;
387 }
388 #endif
389
neigh_hh_output(const struct hh_cache * hh,struct sk_buff * skb)390 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
391 {
392 unsigned int seq;
393 int hh_len;
394
395 do {
396 seq = read_seqbegin(&hh->hh_lock);
397 hh_len = hh->hh_len;
398 if (likely(hh_len <= HH_DATA_MOD)) {
399 /* this is inlined by gcc */
400 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD);
401 } else {
402 int hh_alen = HH_DATA_ALIGN(hh_len);
403
404 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
405 }
406 } while (read_seqretry(&hh->hh_lock, seq));
407
408 skb_push(skb, hh_len);
409 return dev_queue_xmit(skb);
410 }
411
412 static inline struct neighbour *
__neigh_lookup(struct neigh_table * tbl,const void * pkey,struct net_device * dev,int creat)413 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
414 {
415 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
416
417 if (n || !creat)
418 return n;
419
420 n = neigh_create(tbl, pkey, dev);
421 return IS_ERR(n) ? NULL : n;
422 }
423
424 static inline struct neighbour *
__neigh_lookup_errno(struct neigh_table * tbl,const void * pkey,struct net_device * dev)425 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
426 struct net_device *dev)
427 {
428 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
429
430 if (n)
431 return n;
432
433 return neigh_create(tbl, pkey, dev);
434 }
435
436 struct neighbour_cb {
437 unsigned long sched_next;
438 unsigned int flags;
439 };
440
441 #define LOCALLY_ENQUEUED 0x1
442
443 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
444
neigh_ha_snapshot(char * dst,const struct neighbour * n,const struct net_device * dev)445 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
446 const struct net_device *dev)
447 {
448 unsigned int seq;
449
450 do {
451 seq = read_seqbegin(&n->ha_lock);
452 memcpy(dst, n->ha, dev->addr_len);
453 } while (read_seqretry(&n->ha_lock, seq));
454 }
455 #endif
456