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 struct neigh_table *tbl;
81 struct rcu_head rcu_head;
84 int data[NEIGH_VAR_DATA_MAX];
85 DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX);
88 static inline void neigh_var_set(struct neigh_parms *p, int index, int val)
90 set_bit(index, p->data_state);
94 #define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr])
96 /* In ndo_neigh_setup, NEIGH_VAR_INIT should be used.
97 * In other cases, NEIGH_VAR_SET should be used.
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)
102 static inline void neigh_parms_data_state_setall(struct neigh_parms *p)
104 bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX);
107 static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p)
109 bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX);
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 */
117 unsigned long res_failed; /* number of failed resolutions */
119 unsigned long lookups; /* number of lookups */
120 unsigned long hits; /* number of hits (among lookups) */
122 unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
123 unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
125 unsigned long periodic_gc_runs; /* number of periodic GC runs */
126 unsigned long forced_gc_runs; /* number of forced GC runs */
128 unsigned long unres_discards; /* number of unresolved drops */
129 unsigned long table_fulls; /* times even gc couldn't help */
132 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
135 struct neighbour __rcu *next;
136 struct neigh_table *tbl;
137 struct neigh_parms *parms;
138 unsigned long confirmed;
139 unsigned long updated;
142 unsigned int arp_queue_len_bytes;
143 struct sk_buff_head arp_queue;
144 struct timer_list timer;
153 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))] __aligned(8);
155 int (*output)(struct neighbour *, struct sk_buff *);
156 const struct neigh_ops *ops;
157 struct list_head gc_list;
159 struct net_device *dev;
161 } __randomize_layout;
165 void (*solicit)(struct neighbour *, struct sk_buff *);
166 void (*error_report)(struct neighbour *, struct sk_buff *);
167 int (*output)(struct neighbour *, struct sk_buff *);
168 int (*connected_output)(struct neighbour *, struct sk_buff *);
171 struct pneigh_entry {
172 struct pneigh_entry *next;
174 struct net_device *dev;
181 * neighbour table manipulation
184 #define NEIGH_NUM_HASH_RND 4
186 struct neigh_hash_table {
187 struct neighbour __rcu **hash_buckets;
188 unsigned int hash_shift;
189 __u32 hash_rnd[NEIGH_NUM_HASH_RND];
196 unsigned int entry_size;
197 unsigned int key_len;
199 __u32 (*hash)(const void *pkey,
200 const struct net_device *dev,
202 bool (*key_eq)(const struct neighbour *, const void *pkey);
203 int (*constructor)(struct neighbour *);
204 int (*pconstructor)(struct pneigh_entry *);
205 void (*pdestructor)(struct pneigh_entry *);
206 void (*proxy_redo)(struct sk_buff *skb);
207 int (*is_multicast)(const void *pkey);
208 bool (*allow_add)(const struct net_device *dev,
209 struct netlink_ext_ack *extack);
211 struct neigh_parms parms;
212 struct list_head parms_list;
217 unsigned long last_flush;
218 struct delayed_work gc_work;
219 struct timer_list proxy_timer;
220 struct sk_buff_head proxy_queue;
223 struct list_head gc_list;
225 unsigned long last_rand;
226 struct neigh_statistics __percpu *stats;
227 struct neigh_hash_table __rcu *nht;
228 struct pneigh_entry **phash_buckets;
236 NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
239 static inline int neigh_parms_family(struct neigh_parms *p)
241 return p->tbl->family;
244 #define NEIGH_PRIV_ALIGN sizeof(long long)
245 #define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN)
247 static inline void *neighbour_priv(const struct neighbour *n)
249 return (char *)n + n->tbl->entry_size;
252 /* flags for neigh_update() */
253 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001
254 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002
255 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004
256 #define NEIGH_UPDATE_F_USE 0x10000000
257 #define NEIGH_UPDATE_F_EXT_LEARNED 0x20000000
258 #define NEIGH_UPDATE_F_ISROUTER 0x40000000
259 #define NEIGH_UPDATE_F_ADMIN 0x80000000
261 extern const struct nla_policy nda_policy[];
263 static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey)
265 return *(const u16 *)n->primary_key == *(const u16 *)pkey;
268 static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey)
270 return *(const u32 *)n->primary_key == *(const u32 *)pkey;
273 static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey)
275 const u32 *n32 = (const u32 *)n->primary_key;
276 const u32 *p32 = pkey;
278 return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
279 (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0;
282 static inline struct neighbour *___neigh_lookup_noref(
283 struct neigh_table *tbl,
284 bool (*key_eq)(const struct neighbour *n, const void *pkey),
285 __u32 (*hash)(const void *pkey,
286 const struct net_device *dev,
289 struct net_device *dev)
291 struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht);
295 hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
296 for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
298 n = rcu_dereference_bh(n->next)) {
299 if (n->dev == dev && key_eq(n, pkey))
306 static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl,
308 struct net_device *dev)
310 return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
313 void neigh_table_init(int index, struct neigh_table *tbl);
314 int neigh_table_clear(int index, struct neigh_table *tbl);
315 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
316 struct net_device *dev);
317 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
319 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
320 struct net_device *dev, bool want_ref);
321 static inline struct neighbour *neigh_create(struct neigh_table *tbl,
323 struct net_device *dev)
325 return __neigh_create(tbl, pkey, dev, true);
327 void neigh_destroy(struct neighbour *neigh);
328 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
329 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
331 void __neigh_set_probe_once(struct neighbour *neigh);
332 bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
333 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
334 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
335 int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev);
336 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
337 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
338 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
339 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
340 u8 *lladdr, void *saddr,
341 struct net_device *dev);
343 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
344 struct neigh_table *tbl);
345 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
348 struct net *neigh_parms_net(const struct neigh_parms *parms)
350 return read_pnet(&parms->net);
353 unsigned long neigh_rand_reach_time(unsigned long base);
355 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
356 struct sk_buff *skb);
357 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
358 const void *key, struct net_device *dev,
360 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
361 const void *key, struct net_device *dev);
362 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
363 struct net_device *dev);
365 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
367 return read_pnet(&pneigh->net);
370 void neigh_app_ns(struct neighbour *n);
371 void neigh_for_each(struct neigh_table *tbl,
372 void (*cb)(struct neighbour *, void *), void *cookie);
373 void __neigh_for_each_release(struct neigh_table *tbl,
374 int (*cb)(struct neighbour *));
375 int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *);
376 void pneigh_for_each(struct neigh_table *tbl,
377 void (*cb)(struct pneigh_entry *));
379 struct neigh_seq_state {
380 struct seq_net_private p;
381 struct neigh_table *tbl;
382 struct neigh_hash_table *nht;
383 void *(*neigh_sub_iter)(struct neigh_seq_state *state,
384 struct neighbour *n, loff_t *pos);
387 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001
388 #define NEIGH_SEQ_IS_PNEIGH 0x00000002
389 #define NEIGH_SEQ_SKIP_NOARP 0x00000004
391 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
393 void *neigh_seq_next(struct seq_file *, void *, loff_t *);
394 void neigh_seq_stop(struct seq_file *, void *);
396 int neigh_proc_dointvec(struct ctl_table *ctl, int write,
397 void *buffer, size_t *lenp, loff_t *ppos);
398 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
400 size_t *lenp, loff_t *ppos);
401 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
402 void *buffer, size_t *lenp, loff_t *ppos);
404 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
405 proc_handler *proc_handler);
406 void neigh_sysctl_unregister(struct neigh_parms *p);
408 static inline void __neigh_parms_put(struct neigh_parms *parms)
410 refcount_dec(&parms->refcnt);
413 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
415 refcount_inc(&parms->refcnt);
420 * Neighbour references
423 static inline void neigh_release(struct neighbour *neigh)
425 if (refcount_dec_and_test(&neigh->refcnt))
426 neigh_destroy(neigh);
429 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
432 refcount_inc(&neigh->refcnt);
436 #define neigh_hold(n) refcount_inc(&(n)->refcnt)
438 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
440 unsigned long now = jiffies;
442 if (READ_ONCE(neigh->used) != now)
443 WRITE_ONCE(neigh->used, now);
444 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
445 return __neigh_event_send(neigh, skb);
449 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
450 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
452 unsigned int seq, hh_alen;
455 seq = read_seqbegin(&hh->hh_lock);
456 hh_alen = HH_DATA_ALIGN(ETH_HLEN);
457 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
458 } while (read_seqretry(&hh->hh_lock, seq));
463 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
465 unsigned int hh_alen = 0;
470 seq = read_seqbegin(&hh->hh_lock);
471 hh_len = READ_ONCE(hh->hh_len);
472 if (likely(hh_len <= HH_DATA_MOD)) {
473 hh_alen = HH_DATA_MOD;
475 /* skb_push() would proceed silently if we have room for
476 * the unaligned size but not for the aligned size:
477 * check headroom explicitly.
479 if (likely(skb_headroom(skb) >= HH_DATA_MOD)) {
480 /* this is inlined by gcc */
481 memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
485 hh_alen = HH_DATA_ALIGN(hh_len);
487 if (likely(skb_headroom(skb) >= hh_alen)) {
488 memcpy(skb->data - hh_alen, hh->hh_data,
492 } while (read_seqretry(&hh->hh_lock, seq));
494 if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) {
496 return NET_XMIT_DROP;
499 __skb_push(skb, hh_len);
500 return dev_queue_xmit(skb);
503 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb,
506 const struct hh_cache *hh = &n->hh;
508 /* n->nud_state and hh->hh_len could be changed under us.
509 * neigh_hh_output() is taking care of the race later.
512 (READ_ONCE(n->nud_state) & NUD_CONNECTED) &&
513 READ_ONCE(hh->hh_len))
514 return neigh_hh_output(hh, skb);
516 return n->output(n, skb);
519 static inline struct neighbour *
520 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
522 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
527 n = neigh_create(tbl, pkey, dev);
528 return IS_ERR(n) ? NULL : n;
531 static inline struct neighbour *
532 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
533 struct net_device *dev)
535 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
540 return neigh_create(tbl, pkey, dev);
543 struct neighbour_cb {
544 unsigned long sched_next;
548 #define LOCALLY_ENQUEUED 0x1
550 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
552 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
553 const struct net_device *dev)
558 seq = read_seqbegin(&n->ha_lock);
559 memcpy(dst, n->ha, dev->addr_len);
560 } while (read_seqretry(&n->ha_lock, seq));
563 static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags,
568 ndm_flags |= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0;
569 if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) {
570 if (ndm_flags & NTF_ROUTER)
571 neigh->flags |= NTF_ROUTER;
573 neigh->flags &= ~NTF_ROUTER;