1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _NET_NEIGHBOUR_H
3 #define _NET_NEIGHBOUR_H
5 #include <linux/neighbour.h>
8 * Generic neighbour manipulation
11 * Pedro Roque <roque@di.fc.ul.pt>
12 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
16 * Harald Welte: <laforge@gnumonks.org>
17 * - Add neighbour cache statistics like rtstat
20 #include <linux/atomic.h>
21 #include <linux/refcount.h>
22 #include <linux/netdevice.h>
23 #include <linux/skbuff.h>
24 #include <linux/rcupdate.h>
25 #include <linux/seq_file.h>
26 #include <linux/bitmap.h>
28 #include <linux/err.h>
29 #include <linux/sysctl.h>
30 #include <linux/workqueue.h>
31 #include <net/rtnetlink.h>
34 * NUD stands for "neighbor unreachability detection"
37 #define NUD_IN_TIMER (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
38 #define NUD_VALID (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
39 #define NUD_CONNECTED (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
44 NEIGH_VAR_MCAST_PROBES,
45 NEIGH_VAR_UCAST_PROBES,
47 NEIGH_VAR_MCAST_REPROBES,
48 NEIGH_VAR_RETRANS_TIME,
49 NEIGH_VAR_BASE_REACHABLE_TIME,
50 NEIGH_VAR_DELAY_PROBE_TIME,
51 NEIGH_VAR_GC_STALETIME,
52 NEIGH_VAR_QUEUE_LEN_BYTES,
54 NEIGH_VAR_ANYCAST_DELAY,
55 NEIGH_VAR_PROXY_DELAY,
57 #define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1)
58 /* Following are used as a second way to access one of the above */
59 NEIGH_VAR_QUEUE_LEN, /* same data as NEIGH_VAR_QUEUE_LEN_BYTES */
60 NEIGH_VAR_RETRANS_TIME_MS, /* same data as NEIGH_VAR_RETRANS_TIME */
61 NEIGH_VAR_BASE_REACHABLE_TIME_MS, /* same data as NEIGH_VAR_BASE_REACHABLE_TIME */
62 /* Following are used by "default" only */
63 NEIGH_VAR_GC_INTERVAL,
72 struct net_device *dev;
73 struct list_head list;
74 int (*neigh_setup)(struct neighbour *);
75 void (*neigh_cleanup)(struct neighbour *);
76 struct neigh_table *tbl;
82 struct rcu_head rcu_head;
85 int data[NEIGH_VAR_DATA_MAX];
86 DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX);
89 static inline void neigh_var_set(struct neigh_parms *p, int index, int val)
91 set_bit(index, p->data_state);
95 #define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr])
97 /* In ndo_neigh_setup, NEIGH_VAR_INIT should be used.
98 * In other cases, NEIGH_VAR_SET should be used.
100 #define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val)
101 #define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val)
103 static inline void neigh_parms_data_state_setall(struct neigh_parms *p)
105 bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX);
108 static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p)
110 bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX);
113 struct neigh_statistics {
114 unsigned long allocs; /* number of allocated neighs */
115 unsigned long destroys; /* number of destroyed neighs */
116 unsigned long hash_grows; /* number of hash resizes */
118 unsigned long res_failed; /* number of failed resolutions */
120 unsigned long lookups; /* number of lookups */
121 unsigned long hits; /* number of hits (among lookups) */
123 unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
124 unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
126 unsigned long periodic_gc_runs; /* number of periodic GC runs */
127 unsigned long forced_gc_runs; /* number of forced GC runs */
129 unsigned long unres_discards; /* number of unresolved drops */
130 unsigned long table_fulls; /* times even gc couldn't help */
133 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
136 struct neighbour __rcu *next;
137 struct neigh_table *tbl;
138 struct neigh_parms *parms;
139 unsigned long confirmed;
140 unsigned long updated;
143 struct sk_buff_head arp_queue;
144 unsigned int arp_queue_len_bytes;
145 struct timer_list timer;
153 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
155 int (*output)(struct neighbour *, struct sk_buff *);
156 const struct neigh_ops *ops;
158 struct net_device *dev;
160 } __randomize_layout;
164 void (*solicit)(struct neighbour *, struct sk_buff *);
165 void (*error_report)(struct neighbour *, struct sk_buff *);
166 int (*output)(struct neighbour *, struct sk_buff *);
167 int (*connected_output)(struct neighbour *, struct sk_buff *);
170 struct pneigh_entry {
171 struct pneigh_entry *next;
173 struct net_device *dev;
179 * neighbour table manipulation
182 #define NEIGH_NUM_HASH_RND 4
184 struct neigh_hash_table {
185 struct neighbour __rcu **hash_buckets;
186 unsigned int hash_shift;
187 __u32 hash_rnd[NEIGH_NUM_HASH_RND];
194 unsigned int entry_size;
195 unsigned int key_len;
197 __u32 (*hash)(const void *pkey,
198 const struct net_device *dev,
200 bool (*key_eq)(const struct neighbour *, const void *pkey);
201 int (*constructor)(struct neighbour *);
202 int (*pconstructor)(struct pneigh_entry *);
203 void (*pdestructor)(struct pneigh_entry *);
204 void (*proxy_redo)(struct sk_buff *skb);
206 struct neigh_parms parms;
207 struct list_head parms_list;
212 unsigned long last_flush;
213 struct delayed_work gc_work;
214 struct timer_list proxy_timer;
215 struct sk_buff_head proxy_queue;
218 unsigned long last_rand;
219 struct neigh_statistics __percpu *stats;
220 struct neigh_hash_table __rcu *nht;
221 struct pneigh_entry **phash_buckets;
229 NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
232 static inline int neigh_parms_family(struct neigh_parms *p)
234 return p->tbl->family;
237 #define NEIGH_PRIV_ALIGN sizeof(long long)
238 #define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN)
240 static inline void *neighbour_priv(const struct neighbour *n)
242 return (char *)n + n->tbl->entry_size;
245 /* flags for neigh_update() */
246 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001
247 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002
248 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004
249 #define NEIGH_UPDATE_F_EXT_LEARNED 0x20000000
250 #define NEIGH_UPDATE_F_ISROUTER 0x40000000
251 #define NEIGH_UPDATE_F_ADMIN 0x80000000
254 static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey)
256 return *(const u16 *)n->primary_key == *(const u16 *)pkey;
259 static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey)
261 return *(const u32 *)n->primary_key == *(const u32 *)pkey;
264 static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey)
266 const u32 *n32 = (const u32 *)n->primary_key;
267 const u32 *p32 = pkey;
269 return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
270 (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0;
273 static inline struct neighbour *___neigh_lookup_noref(
274 struct neigh_table *tbl,
275 bool (*key_eq)(const struct neighbour *n, const void *pkey),
276 __u32 (*hash)(const void *pkey,
277 const struct net_device *dev,
280 struct net_device *dev)
282 struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht);
286 hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
287 for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
289 n = rcu_dereference_bh(n->next)) {
290 if (n->dev == dev && key_eq(n, pkey))
297 static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl,
299 struct net_device *dev)
301 return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
304 void neigh_table_init(int index, struct neigh_table *tbl);
305 int neigh_table_clear(int index, struct neigh_table *tbl);
306 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
307 struct net_device *dev);
308 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
310 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
311 struct net_device *dev, bool want_ref);
312 static inline struct neighbour *neigh_create(struct neigh_table *tbl,
314 struct net_device *dev)
316 return __neigh_create(tbl, pkey, dev, true);
318 void neigh_destroy(struct neighbour *neigh);
319 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
320 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
322 void __neigh_set_probe_once(struct neighbour *neigh);
323 bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
324 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
325 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
326 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
327 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
328 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
329 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
330 u8 *lladdr, void *saddr,
331 struct net_device *dev);
333 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
334 struct neigh_table *tbl);
335 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
338 struct net *neigh_parms_net(const struct neigh_parms *parms)
340 return read_pnet(&parms->net);
343 unsigned long neigh_rand_reach_time(unsigned long base);
345 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
346 struct sk_buff *skb);
347 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
348 const void *key, struct net_device *dev,
350 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
351 const void *key, struct net_device *dev);
352 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
353 struct net_device *dev);
355 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
357 return read_pnet(&pneigh->net);
360 void neigh_app_ns(struct neighbour *n);
361 void neigh_for_each(struct neigh_table *tbl,
362 void (*cb)(struct neighbour *, void *), void *cookie);
363 void __neigh_for_each_release(struct neigh_table *tbl,
364 int (*cb)(struct neighbour *));
365 int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *);
366 void pneigh_for_each(struct neigh_table *tbl,
367 void (*cb)(struct pneigh_entry *));
369 struct neigh_seq_state {
370 struct seq_net_private p;
371 struct neigh_table *tbl;
372 struct neigh_hash_table *nht;
373 void *(*neigh_sub_iter)(struct neigh_seq_state *state,
374 struct neighbour *n, loff_t *pos);
377 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001
378 #define NEIGH_SEQ_IS_PNEIGH 0x00000002
379 #define NEIGH_SEQ_SKIP_NOARP 0x00000004
381 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
383 void *neigh_seq_next(struct seq_file *, void *, loff_t *);
384 void neigh_seq_stop(struct seq_file *, void *);
386 int neigh_proc_dointvec(struct ctl_table *ctl, int write,
387 void __user *buffer, size_t *lenp, loff_t *ppos);
388 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
390 size_t *lenp, loff_t *ppos);
391 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
393 size_t *lenp, loff_t *ppos);
395 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
396 proc_handler *proc_handler);
397 void neigh_sysctl_unregister(struct neigh_parms *p);
399 static inline void __neigh_parms_put(struct neigh_parms *parms)
401 refcount_dec(&parms->refcnt);
404 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
406 refcount_inc(&parms->refcnt);
411 * Neighbour references
414 static inline void neigh_release(struct neighbour *neigh)
416 if (refcount_dec_and_test(&neigh->refcnt))
417 neigh_destroy(neigh);
420 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
423 refcount_inc(&neigh->refcnt);
427 #define neigh_hold(n) refcount_inc(&(n)->refcnt)
429 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
431 unsigned long now = jiffies;
433 if (neigh->used != now)
435 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
436 return __neigh_event_send(neigh, skb);
440 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
441 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
443 unsigned int seq, hh_alen;
446 seq = read_seqbegin(&hh->hh_lock);
447 hh_alen = HH_DATA_ALIGN(ETH_HLEN);
448 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
449 } while (read_seqretry(&hh->hh_lock, seq));
454 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
460 seq = read_seqbegin(&hh->hh_lock);
462 if (likely(hh_len <= HH_DATA_MOD)) {
463 /* this is inlined by gcc */
464 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD);
466 unsigned int hh_alen = HH_DATA_ALIGN(hh_len);
468 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
470 } while (read_seqretry(&hh->hh_lock, seq));
472 skb_push(skb, hh_len);
473 return dev_queue_xmit(skb);
476 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb)
478 const struct hh_cache *hh = &n->hh;
480 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
481 return neigh_hh_output(hh, skb);
483 return n->output(n, skb);
486 static inline struct neighbour *
487 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
489 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
494 n = neigh_create(tbl, pkey, dev);
495 return IS_ERR(n) ? NULL : n;
498 static inline struct neighbour *
499 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
500 struct net_device *dev)
502 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
507 return neigh_create(tbl, pkey, dev);
510 struct neighbour_cb {
511 unsigned long sched_next;
515 #define LOCALLY_ENQUEUED 0x1
517 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
519 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
520 const struct net_device *dev)
525 seq = read_seqbegin(&n->ha_lock);
526 memcpy(dst, n->ha, dev->addr_len);
527 } while (read_seqretry(&n->ha_lock, seq));
530 static inline void neigh_update_ext_learned(struct neighbour *neigh, u32 flags,
535 if (!(flags & NEIGH_UPDATE_F_ADMIN))
538 ndm_flags |= (flags & NEIGH_UPDATE_F_EXT_LEARNED) ? NTF_EXT_LEARNED : 0;
539 if ((neigh->flags ^ ndm_flags) & NTF_EXT_LEARNED) {
540 if (ndm_flags & NTF_EXT_LEARNED)
541 neigh->flags |= NTF_EXT_LEARNED;
543 neigh->flags &= ~NTF_EXT_LEARNED;