1
2#ifndef _NET_NEIGHBOUR_H
3#define _NET_NEIGHBOUR_H
4
5#include <linux/neighbour.h>
6
7
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13
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17
18
19
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>
27
28#include <linux/err.h>
29#include <linux/sysctl.h>
30#include <linux/workqueue.h>
31#include <net/rtnetlink.h>
32
33
34
35
36
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)
40
41struct neighbour;
42
43enum {
44 NEIGH_VAR_MCAST_PROBES,
45 NEIGH_VAR_UCAST_PROBES,
46 NEIGH_VAR_APP_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,
53 NEIGH_VAR_PROXY_QLEN,
54 NEIGH_VAR_ANYCAST_DELAY,
55 NEIGH_VAR_PROXY_DELAY,
56 NEIGH_VAR_LOCKTIME,
57#define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1)
58
59 NEIGH_VAR_QUEUE_LEN,
60 NEIGH_VAR_RETRANS_TIME_MS,
61 NEIGH_VAR_BASE_REACHABLE_TIME_MS,
62
63 NEIGH_VAR_GC_INTERVAL,
64 NEIGH_VAR_GC_THRESH1,
65 NEIGH_VAR_GC_THRESH2,
66 NEIGH_VAR_GC_THRESH3,
67 NEIGH_VAR_MAX
68};
69
70struct neigh_parms {
71 possible_net_t net;
72 struct net_device *dev;
73 struct list_head list;
74 int (*neigh_setup)(struct neighbour *);
75 struct neigh_table *tbl;
76
77 void *sysctl_table;
78
79 int dead;
80 refcount_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
88static 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
97
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
102static inline void neigh_parms_data_state_setall(struct neigh_parms *p)
103{
104 bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX);
105}
106
107static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p)
108{
109 bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX);
110}
111
112struct neigh_statistics {
113 unsigned long allocs;
114 unsigned long destroys;
115 unsigned long hash_grows;
116
117 unsigned long res_failed;
118
119 unsigned long lookups;
120 unsigned long hits;
121
122 unsigned long rcv_probes_mcast;
123 unsigned long rcv_probes_ucast;
124
125 unsigned long periodic_gc_runs;
126 unsigned long forced_gc_runs;
127
128 unsigned long unres_discards;
129 unsigned long table_fulls;
130};
131
132#define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
133
134struct neighbour {
135 struct neighbour __rcu *next;
136 struct neigh_table *tbl;
137 struct neigh_parms *parms;
138 unsigned long confirmed;
139 unsigned long updated;
140 rwlock_t lock;
141 refcount_t refcnt;
142 unsigned int arp_queue_len_bytes;
143 struct sk_buff_head arp_queue;
144 struct timer_list timer;
145 unsigned long used;
146 atomic_t probes;
147 __u8 flags;
148 __u8 nud_state;
149 __u8 type;
150 __u8 dead;
151 u8 protocol;
152 seqlock_t ha_lock;
153 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))] __aligned(8);
154 struct hh_cache hh;
155 int (*output)(struct neighbour *, struct sk_buff *);
156 const struct neigh_ops *ops;
157 struct list_head gc_list;
158 struct rcu_head rcu;
159 struct net_device *dev;
160 u8 primary_key[0];
161} __randomize_layout;
162
163struct neigh_ops {
164 int family;
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 *);
169};
170
171struct pneigh_entry {
172 struct pneigh_entry *next;
173 possible_net_t net;
174 struct net_device *dev;
175 u8 flags;
176 u8 protocol;
177 u8 key[];
178};
179
180
181
182
183
184#define NEIGH_NUM_HASH_RND 4
185
186struct neigh_hash_table {
187 struct neighbour __rcu **hash_buckets;
188 unsigned int hash_shift;
189 __u32 hash_rnd[NEIGH_NUM_HASH_RND];
190 struct rcu_head rcu;
191};
192
193
194struct neigh_table {
195 int family;
196 unsigned int entry_size;
197 unsigned int key_len;
198 __be16 protocol;
199 __u32 (*hash)(const void *pkey,
200 const struct net_device *dev,
201 __u32 *hash_rnd);
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);
210 char *id;
211 struct neigh_parms parms;
212 struct list_head parms_list;
213 int gc_interval;
214 int gc_thresh1;
215 int gc_thresh2;
216 int gc_thresh3;
217 unsigned long last_flush;
218 struct delayed_work gc_work;
219 struct timer_list proxy_timer;
220 struct sk_buff_head proxy_queue;
221 atomic_t entries;
222 atomic_t gc_entries;
223 struct list_head gc_list;
224 rwlock_t lock;
225 unsigned long last_rand;
226 struct neigh_statistics __percpu *stats;
227 struct neigh_hash_table __rcu *nht;
228 struct pneigh_entry **phash_buckets;
229};
230
231enum {
232 NEIGH_ARP_TABLE = 0,
233 NEIGH_ND_TABLE = 1,
234 NEIGH_DN_TABLE = 2,
235 NEIGH_NR_TABLES,
236 NEIGH_LINK_TABLE = NEIGH_NR_TABLES
237};
238
239static inline int neigh_parms_family(struct neigh_parms *p)
240{
241 return p->tbl->family;
242}
243
244#define NEIGH_PRIV_ALIGN sizeof(long long)
245#define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN)
246
247static inline void *neighbour_priv(const struct neighbour *n)
248{
249 return (char *)n + n->tbl->entry_size;
250}
251
252
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_EXT_LEARNED 0x20000000
257#define NEIGH_UPDATE_F_ISROUTER 0x40000000
258#define NEIGH_UPDATE_F_ADMIN 0x80000000
259
260extern const struct nla_policy nda_policy[];
261
262static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey)
263{
264 return *(const u16 *)n->primary_key == *(const u16 *)pkey;
265}
266
267static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey)
268{
269 return *(const u32 *)n->primary_key == *(const u32 *)pkey;
270}
271
272static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey)
273{
274 const u32 *n32 = (const u32 *)n->primary_key;
275 const u32 *p32 = pkey;
276
277 return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
278 (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0;
279}
280
281static inline struct neighbour *___neigh_lookup_noref(
282 struct neigh_table *tbl,
283 bool (*key_eq)(const struct neighbour *n, const void *pkey),
284 __u32 (*hash)(const void *pkey,
285 const struct net_device *dev,
286 __u32 *hash_rnd),
287 const void *pkey,
288 struct net_device *dev)
289{
290 struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht);
291 struct neighbour *n;
292 u32 hash_val;
293
294 hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
295 for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
296 n != NULL;
297 n = rcu_dereference_bh(n->next)) {
298 if (n->dev == dev && key_eq(n, pkey))
299 return n;
300 }
301
302 return NULL;
303}
304
305static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl,
306 const void *pkey,
307 struct net_device *dev)
308{
309 return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
310}
311
312void neigh_table_init(int index, struct neigh_table *tbl);
313int neigh_table_clear(int index, struct neigh_table *tbl);
314struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
315 struct net_device *dev);
316struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
317 const void *pkey);
318struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
319 struct net_device *dev, bool want_ref);
320static inline struct neighbour *neigh_create(struct neigh_table *tbl,
321 const void *pkey,
322 struct net_device *dev)
323{
324 return __neigh_create(tbl, pkey, dev, true);
325}
326void neigh_destroy(struct neighbour *neigh);
327int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
328int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
329 u32 nlmsg_pid);
330void __neigh_set_probe_once(struct neighbour *neigh);
331bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
332void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
333int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
334int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev);
335int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
336int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
337int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
338struct neighbour *neigh_event_ns(struct neigh_table *tbl,
339 u8 *lladdr, void *saddr,
340 struct net_device *dev);
341
342struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
343 struct neigh_table *tbl);
344void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
345
346static inline
347struct net *neigh_parms_net(const struct neigh_parms *parms)
348{
349 return read_pnet(&parms->net);
350}
351
352unsigned long neigh_rand_reach_time(unsigned long base);
353
354void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
355 struct sk_buff *skb);
356struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
357 const void *key, struct net_device *dev,
358 int creat);
359struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
360 const void *key, struct net_device *dev);
361int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
362 struct net_device *dev);
363
364static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
365{
366 return read_pnet(&pneigh->net);
367}
368
369void neigh_app_ns(struct neighbour *n);
370void neigh_for_each(struct neigh_table *tbl,
371 void (*cb)(struct neighbour *, void *), void *cookie);
372void __neigh_for_each_release(struct neigh_table *tbl,
373 int (*cb)(struct neighbour *));
374int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *);
375void pneigh_for_each(struct neigh_table *tbl,
376 void (*cb)(struct pneigh_entry *));
377
378struct neigh_seq_state {
379 struct seq_net_private p;
380 struct neigh_table *tbl;
381 struct neigh_hash_table *nht;
382 void *(*neigh_sub_iter)(struct neigh_seq_state *state,
383 struct neighbour *n, loff_t *pos);
384 unsigned int bucket;
385 unsigned int flags;
386#define NEIGH_SEQ_NEIGH_ONLY 0x00000001
387#define NEIGH_SEQ_IS_PNEIGH 0x00000002
388#define NEIGH_SEQ_SKIP_NOARP 0x00000004
389};
390void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
391 unsigned int);
392void *neigh_seq_next(struct seq_file *, void *, loff_t *);
393void neigh_seq_stop(struct seq_file *, void *);
394
395int neigh_proc_dointvec(struct ctl_table *ctl, int write,
396 void *buffer, size_t *lenp, loff_t *ppos);
397int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
398 void *buffer,
399 size_t *lenp, loff_t *ppos);
400int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
401 void *buffer, size_t *lenp, loff_t *ppos);
402
403int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
404 proc_handler *proc_handler);
405void neigh_sysctl_unregister(struct neigh_parms *p);
406
407static inline void __neigh_parms_put(struct neigh_parms *parms)
408{
409 refcount_dec(&parms->refcnt);
410}
411
412static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
413{
414 refcount_inc(&parms->refcnt);
415 return parms;
416}
417
418
419
420
421
422static inline void neigh_release(struct neighbour *neigh)
423{
424 if (refcount_dec_and_test(&neigh->refcnt))
425 neigh_destroy(neigh);
426}
427
428static inline struct neighbour * neigh_clone(struct neighbour *neigh)
429{
430 if (neigh)
431 refcount_inc(&neigh->refcnt);
432 return neigh;
433}
434
435#define neigh_hold(n) refcount_inc(&(n)->refcnt)
436
437static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
438{
439 unsigned long now = jiffies;
440
441 if (READ_ONCE(neigh->used) != now)
442 WRITE_ONCE(neigh->used, now);
443 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
444 return __neigh_event_send(neigh, skb);
445 return 0;
446}
447
448#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
449static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
450{
451 unsigned int seq, hh_alen;
452
453 do {
454 seq = read_seqbegin(&hh->hh_lock);
455 hh_alen = HH_DATA_ALIGN(ETH_HLEN);
456 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
457 } while (read_seqretry(&hh->hh_lock, seq));
458 return 0;
459}
460#endif
461
462static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
463{
464 unsigned int hh_alen = 0;
465 unsigned int seq;
466 unsigned int hh_len;
467
468 do {
469 seq = read_seqbegin(&hh->hh_lock);
470 hh_len = READ_ONCE(hh->hh_len);
471 if (likely(hh_len <= HH_DATA_MOD)) {
472 hh_alen = HH_DATA_MOD;
473
474
475
476
477
478 if (likely(skb_headroom(skb) >= HH_DATA_MOD)) {
479
480 memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
481 HH_DATA_MOD);
482 }
483 } else {
484 hh_alen = HH_DATA_ALIGN(hh_len);
485
486 if (likely(skb_headroom(skb) >= hh_alen)) {
487 memcpy(skb->data - hh_alen, hh->hh_data,
488 hh_alen);
489 }
490 }
491 } while (read_seqretry(&hh->hh_lock, seq));
492
493 if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) {
494 kfree_skb(skb);
495 return NET_XMIT_DROP;
496 }
497
498 __skb_push(skb, hh_len);
499 return dev_queue_xmit(skb);
500}
501
502static inline int neigh_output(struct neighbour *n, struct sk_buff *skb,
503 bool skip_cache)
504{
505 const struct hh_cache *hh = &n->hh;
506
507 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len && !skip_cache)
508 return neigh_hh_output(hh, skb);
509 else
510 return n->output(n, skb);
511}
512
513static inline struct neighbour *
514__neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
515{
516 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
517
518 if (n || !creat)
519 return n;
520
521 n = neigh_create(tbl, pkey, dev);
522 return IS_ERR(n) ? NULL : n;
523}
524
525static inline struct neighbour *
526__neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
527 struct net_device *dev)
528{
529 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
530
531 if (n)
532 return n;
533
534 return neigh_create(tbl, pkey, dev);
535}
536
537struct neighbour_cb {
538 unsigned long sched_next;
539 unsigned int flags;
540};
541
542#define LOCALLY_ENQUEUED 0x1
543
544#define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
545
546static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
547 const struct net_device *dev)
548{
549 unsigned int seq;
550
551 do {
552 seq = read_seqbegin(&n->ha_lock);
553 memcpy(dst, n->ha, dev->addr_len);
554 } while (read_seqretry(&n->ha_lock, seq));
555}
556
557static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags,
558 int *notify)
559{
560 u8 ndm_flags = 0;
561
562 ndm_flags |= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0;
563 if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) {
564 if (ndm_flags & NTF_ROUTER)
565 neigh->flags |= NTF_ROUTER;
566 else
567 neigh->flags &= ~NTF_ROUTER;
568 *notify = 1;
569 }
570}
571#endif
572
