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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _NET_NEIGHBOUR_H
3#define _NET_NEIGHBOUR_H
4
5#include <linux/neighbour.h>
6
7/*
8 * Generic neighbour manipulation
9 *
10 * Authors:
11 * Pedro Roque <roque@di.fc.ul.pt>
12 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
13 *
14 * Changes:
15 *
16 * Harald Welte: <laforge@gnumonks.org>
17 * - Add neighbour cache statistics like rtstat
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 * NUD stands for "neighbor unreachability detection"
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 /* 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,
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/* 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
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; /* 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 unsigned long table_fulls; /* times even gc couldn't help */
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 * neighbour table manipulation
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 bool (*allow_add)(const struct net_device *dev,
208 struct netlink_ext_ack *extack);
209 char *id;
210 struct neigh_parms parms;
211 struct list_head parms_list;
212 int gc_interval;
213 int gc_thresh1;
214 int gc_thresh2;
215 int gc_thresh3;
216 unsigned long last_flush;
217 struct delayed_work gc_work;
218 struct timer_list proxy_timer;
219 struct sk_buff_head proxy_queue;
220 atomic_t entries;
221 atomic_t gc_entries;
222 struct list_head gc_list;
223 rwlock_t lock;
224 unsigned long last_rand;
225 struct neigh_statistics __percpu *stats;
226 struct neigh_hash_table __rcu *nht;
227 struct pneigh_entry **phash_buckets;
228};
229
230enum {
231 NEIGH_ARP_TABLE = 0,
232 NEIGH_ND_TABLE = 1,
233 NEIGH_DN_TABLE = 2,
234 NEIGH_NR_TABLES,
235 NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
236};
237
238static inline int neigh_parms_family(struct neigh_parms *p)
239{
240 return p->tbl->family;
241}
242
243#define NEIGH_PRIV_ALIGN sizeof(long long)
244#define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN)
245
246static inline void *neighbour_priv(const struct neighbour *n)
247{
248 return (char *)n + n->tbl->entry_size;
249}
250
251/* flags for neigh_update() */
252#define NEIGH_UPDATE_F_OVERRIDE 0x00000001
253#define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002
254#define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004
255#define NEIGH_UPDATE_F_EXT_LEARNED 0x20000000
256#define NEIGH_UPDATE_F_ISROUTER 0x40000000
257#define NEIGH_UPDATE_F_ADMIN 0x80000000
258
259extern const struct nla_policy nda_policy[];
260
261static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey)
262{
263 return *(const u16 *)n->primary_key == *(const u16 *)pkey;
264}
265
266static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey)
267{
268 return *(const u32 *)n->primary_key == *(const u32 *)pkey;
269}
270
271static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey)
272{
273 const u32 *n32 = (const u32 *)n->primary_key;
274 const u32 *p32 = pkey;
275
276 return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
277 (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0;
278}
279
280static inline struct neighbour *___neigh_lookup_noref(
281 struct neigh_table *tbl,
282 bool (*key_eq)(const struct neighbour *n, const void *pkey),
283 __u32 (*hash)(const void *pkey,
284 const struct net_device *dev,
285 __u32 *hash_rnd),
286 const void *pkey,
287 struct net_device *dev)
288{
289 struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht);
290 struct neighbour *n;
291 u32 hash_val;
292
293 hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
294 for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
295 n != NULL;
296 n = rcu_dereference_bh(n->next)) {
297 if (n->dev == dev && key_eq(n, pkey))
298 return n;
299 }
300
301 return NULL;
302}
303
304static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl,
305 const void *pkey,
306 struct net_device *dev)
307{
308 return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
309}
310
311void neigh_table_init(int index, struct neigh_table *tbl);
312int neigh_table_clear(int index, struct neigh_table *tbl);
313struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
314 struct net_device *dev);
315struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
316 const void *pkey);
317struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
318 struct net_device *dev, bool want_ref);
319static inline struct neighbour *neigh_create(struct neigh_table *tbl,
320 const void *pkey,
321 struct net_device *dev)
322{
323 return __neigh_create(tbl, pkey, dev, true);
324}
325void neigh_destroy(struct neighbour *neigh);
326int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
327int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
328 u32 nlmsg_pid);
329void __neigh_set_probe_once(struct neighbour *neigh);
330bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
331void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
332int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
333int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev);
334int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
335int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
336int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
337struct neighbour *neigh_event_ns(struct neigh_table *tbl,
338 u8 *lladdr, void *saddr,
339 struct net_device *dev);
340
341struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
342 struct neigh_table *tbl);
343void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
344
345static inline
346struct net *neigh_parms_net(const struct neigh_parms *parms)
347{
348 return read_pnet(&parms->net);
349}
350
351unsigned long neigh_rand_reach_time(unsigned long base);
352
353void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
354 struct sk_buff *skb);
355struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
356 const void *key, struct net_device *dev,
357 int creat);
358struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
359 const void *key, struct net_device *dev);
360int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
361 struct net_device *dev);
362
363static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
364{
365 return read_pnet(&pneigh->net);
366}
367
368void neigh_app_ns(struct neighbour *n);
369void neigh_for_each(struct neigh_table *tbl,
370 void (*cb)(struct neighbour *, void *), void *cookie);
371void __neigh_for_each_release(struct neigh_table *tbl,
372 int (*cb)(struct neighbour *));
373int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *);
374void pneigh_for_each(struct neigh_table *tbl,
375 void (*cb)(struct pneigh_entry *));
376
377struct neigh_seq_state {
378 struct seq_net_private p;
379 struct neigh_table *tbl;
380 struct neigh_hash_table *nht;
381 void *(*neigh_sub_iter)(struct neigh_seq_state *state,
382 struct neighbour *n, loff_t *pos);
383 unsigned int bucket;
384 unsigned int flags;
385#define NEIGH_SEQ_NEIGH_ONLY 0x00000001
386#define NEIGH_SEQ_IS_PNEIGH 0x00000002
387#define NEIGH_SEQ_SKIP_NOARP 0x00000004
388};
389void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
390 unsigned int);
391void *neigh_seq_next(struct seq_file *, void *, loff_t *);
392void neigh_seq_stop(struct seq_file *, void *);
393
394int neigh_proc_dointvec(struct ctl_table *ctl, int write,
395 void *buffer, size_t *lenp, loff_t *ppos);
396int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
397 void *buffer,
398 size_t *lenp, loff_t *ppos);
399int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
400 void *buffer, size_t *lenp, loff_t *ppos);
401
402int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
403 proc_handler *proc_handler);
404void neigh_sysctl_unregister(struct neigh_parms *p);
405
406static inline void __neigh_parms_put(struct neigh_parms *parms)
407{
408 refcount_dec(&parms->refcnt);
409}
410
411static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
412{
413 refcount_inc(&parms->refcnt);
414 return parms;
415}
416
417/*
418 * Neighbour references
419 */
420
421static inline void neigh_release(struct neighbour *neigh)
422{
423 if (refcount_dec_and_test(&neigh->refcnt))
424 neigh_destroy(neigh);
425}
426
427static inline struct neighbour * neigh_clone(struct neighbour *neigh)
428{
429 if (neigh)
430 refcount_inc(&neigh->refcnt);
431 return neigh;
432}
433
434#define neigh_hold(n) refcount_inc(&(n)->refcnt)
435
436static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
437{
438 unsigned long now = jiffies;
439
440 if (READ_ONCE(neigh->used) != now)
441 WRITE_ONCE(neigh->used, now);
442 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
443 return __neigh_event_send(neigh, skb);
444 return 0;
445}
446
447#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
448static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
449{
450 unsigned int seq, hh_alen;
451
452 do {
453 seq = read_seqbegin(&hh->hh_lock);
454 hh_alen = HH_DATA_ALIGN(ETH_HLEN);
455 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
456 } while (read_seqretry(&hh->hh_lock, seq));
457 return 0;
458}
459#endif
460
461static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
462{
463 unsigned int hh_alen = 0;
464 unsigned int seq;
465 unsigned int hh_len;
466
467 do {
468 seq = read_seqbegin(&hh->hh_lock);
469 hh_len = READ_ONCE(hh->hh_len);
470 if (likely(hh_len <= HH_DATA_MOD)) {
471 hh_alen = HH_DATA_MOD;
472
473 /* skb_push() would proceed silently if we have room for
474 * the unaligned size but not for the aligned size:
475 * check headroom explicitly.
476 */
477 if (likely(skb_headroom(skb) >= HH_DATA_MOD)) {
478 /* this is inlined by gcc */
479 memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
480 HH_DATA_MOD);
481 }
482 } else {
483 hh_alen = HH_DATA_ALIGN(hh_len);
484
485 if (likely(skb_headroom(skb) >= hh_alen)) {
486 memcpy(skb->data - hh_alen, hh->hh_data,
487 hh_alen);
488 }
489 }
490 } while (read_seqretry(&hh->hh_lock, seq));
491
492 if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) {
493 kfree_skb(skb);
494 return NET_XMIT_DROP;
495 }
496
497 __skb_push(skb, hh_len);
498 return dev_queue_xmit(skb);
499}
500
501static inline int neigh_output(struct neighbour *n, struct sk_buff *skb,
502 bool skip_cache)
503{
504 const struct hh_cache *hh = &n->hh;
505
506 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len && !skip_cache)
507 return neigh_hh_output(hh, skb);
508 else
509 return n->output(n, skb);
510}
511
512static inline struct neighbour *
513__neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
514{
515 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
516
517 if (n || !creat)
518 return n;
519
520 n = neigh_create(tbl, pkey, dev);
521 return IS_ERR(n) ? NULL : n;
522}
523
524static inline struct neighbour *
525__neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
526 struct net_device *dev)
527{
528 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
529
530 if (n)
531 return n;
532
533 return neigh_create(tbl, pkey, dev);
534}
535
536struct neighbour_cb {
537 unsigned long sched_next;
538 unsigned int flags;
539};
540
541#define LOCALLY_ENQUEUED 0x1
542
543#define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
544
545static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
546 const struct net_device *dev)
547{
548 unsigned int seq;
549
550 do {
551 seq = read_seqbegin(&n->ha_lock);
552 memcpy(dst, n->ha, dev->addr_len);
553 } while (read_seqretry(&n->ha_lock, seq));
554}
555
556static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags,
557 int *notify)
558{
559 u8 ndm_flags = 0;
560
561 ndm_flags |= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0;
562 if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) {
563 if (ndm_flags & NTF_ROUTER)
564 neigh->flags |= NTF_ROUTER;
565 else
566 neigh->flags &= ~NTF_ROUTER;
567 *notify = 1;
568 }
569}
570#endif
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _NET_NEIGHBOUR_H
3#define _NET_NEIGHBOUR_H
4
5#include <linux/neighbour.h>
6
7/*
8 * Generic neighbour manipulation
9 *
10 * Authors:
11 * Pedro Roque <roque@di.fc.ul.pt>
12 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
13 *
14 * Changes:
15 *
16 * Harald Welte: <laforge@gnumonks.org>
17 * - Add neighbour cache statistics like rtstat
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 * NUD stands for "neighbor unreachability detection"
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_INTERVAL_PROBE_TIME_MS,
52 NEIGH_VAR_GC_STALETIME,
53 NEIGH_VAR_QUEUE_LEN_BYTES,
54 NEIGH_VAR_PROXY_QLEN,
55 NEIGH_VAR_ANYCAST_DELAY,
56 NEIGH_VAR_PROXY_DELAY,
57 NEIGH_VAR_LOCKTIME,
58#define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1)
59 /* Following are used as a second way to access one of the above */
60 NEIGH_VAR_QUEUE_LEN, /* same data as NEIGH_VAR_QUEUE_LEN_BYTES */
61 NEIGH_VAR_RETRANS_TIME_MS, /* same data as NEIGH_VAR_RETRANS_TIME */
62 NEIGH_VAR_BASE_REACHABLE_TIME_MS, /* same data as NEIGH_VAR_BASE_REACHABLE_TIME */
63 /* Following are used by "default" only */
64 NEIGH_VAR_GC_INTERVAL,
65 NEIGH_VAR_GC_THRESH1,
66 NEIGH_VAR_GC_THRESH2,
67 NEIGH_VAR_GC_THRESH3,
68 NEIGH_VAR_MAX
69};
70
71struct neigh_parms {
72 possible_net_t net;
73 struct net_device *dev;
74 netdevice_tracker dev_tracker;
75 struct list_head list;
76 int (*neigh_setup)(struct neighbour *);
77 struct neigh_table *tbl;
78
79 void *sysctl_table;
80
81 int dead;
82 refcount_t refcnt;
83 struct rcu_head rcu_head;
84
85 int reachable_time;
86 u32 qlen;
87 int data[NEIGH_VAR_DATA_MAX];
88 DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX);
89};
90
91static inline void neigh_var_set(struct neigh_parms *p, int index, int val)
92{
93 set_bit(index, p->data_state);
94 p->data[index] = val;
95}
96
97#define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr])
98
99/* In ndo_neigh_setup, NEIGH_VAR_INIT should be used.
100 * In other cases, NEIGH_VAR_SET should be used.
101 */
102#define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val)
103#define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val)
104
105static inline void neigh_parms_data_state_setall(struct neigh_parms *p)
106{
107 bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX);
108}
109
110static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p)
111{
112 bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX);
113}
114
115struct neigh_statistics {
116 unsigned long allocs; /* number of allocated neighs */
117 unsigned long destroys; /* number of destroyed neighs */
118 unsigned long hash_grows; /* number of hash resizes */
119
120 unsigned long res_failed; /* number of failed resolutions */
121
122 unsigned long lookups; /* number of lookups */
123 unsigned long hits; /* number of hits (among lookups) */
124
125 unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
126 unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
127
128 unsigned long periodic_gc_runs; /* number of periodic GC runs */
129 unsigned long forced_gc_runs; /* number of forced GC runs */
130
131 unsigned long unres_discards; /* number of unresolved drops */
132 unsigned long table_fulls; /* times even gc couldn't help */
133};
134
135#define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
136
137struct neighbour {
138 struct neighbour __rcu *next;
139 struct neigh_table *tbl;
140 struct neigh_parms *parms;
141 unsigned long confirmed;
142 unsigned long updated;
143 rwlock_t lock;
144 refcount_t refcnt;
145 unsigned int arp_queue_len_bytes;
146 struct sk_buff_head arp_queue;
147 struct timer_list timer;
148 unsigned long used;
149 atomic_t probes;
150 u8 nud_state;
151 u8 type;
152 u8 dead;
153 u8 protocol;
154 u32 flags;
155 seqlock_t ha_lock;
156 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))] __aligned(8);
157 struct hh_cache hh;
158 int (*output)(struct neighbour *, struct sk_buff *);
159 const struct neigh_ops *ops;
160 struct list_head gc_list;
161 struct list_head managed_list;
162 struct rcu_head rcu;
163 struct net_device *dev;
164 netdevice_tracker dev_tracker;
165 u8 primary_key[0];
166} __randomize_layout;
167
168struct neigh_ops {
169 int family;
170 void (*solicit)(struct neighbour *, struct sk_buff *);
171 void (*error_report)(struct neighbour *, struct sk_buff *);
172 int (*output)(struct neighbour *, struct sk_buff *);
173 int (*connected_output)(struct neighbour *, struct sk_buff *);
174};
175
176struct pneigh_entry {
177 struct pneigh_entry *next;
178 possible_net_t net;
179 struct net_device *dev;
180 netdevice_tracker dev_tracker;
181 u32 flags;
182 u8 protocol;
183 u8 key[];
184};
185
186/*
187 * neighbour table manipulation
188 */
189
190#define NEIGH_NUM_HASH_RND 4
191
192struct neigh_hash_table {
193 struct neighbour __rcu **hash_buckets;
194 unsigned int hash_shift;
195 __u32 hash_rnd[NEIGH_NUM_HASH_RND];
196 struct rcu_head rcu;
197};
198
199
200struct neigh_table {
201 int family;
202 unsigned int entry_size;
203 unsigned int key_len;
204 __be16 protocol;
205 __u32 (*hash)(const void *pkey,
206 const struct net_device *dev,
207 __u32 *hash_rnd);
208 bool (*key_eq)(const struct neighbour *, const void *pkey);
209 int (*constructor)(struct neighbour *);
210 int (*pconstructor)(struct pneigh_entry *);
211 void (*pdestructor)(struct pneigh_entry *);
212 void (*proxy_redo)(struct sk_buff *skb);
213 int (*is_multicast)(const void *pkey);
214 bool (*allow_add)(const struct net_device *dev,
215 struct netlink_ext_ack *extack);
216 char *id;
217 struct neigh_parms parms;
218 struct list_head parms_list;
219 int gc_interval;
220 int gc_thresh1;
221 int gc_thresh2;
222 int gc_thresh3;
223 unsigned long last_flush;
224 struct delayed_work gc_work;
225 struct delayed_work managed_work;
226 struct timer_list proxy_timer;
227 struct sk_buff_head proxy_queue;
228 atomic_t entries;
229 atomic_t gc_entries;
230 struct list_head gc_list;
231 struct list_head managed_list;
232 rwlock_t lock;
233 unsigned long last_rand;
234 struct neigh_statistics __percpu *stats;
235 struct neigh_hash_table __rcu *nht;
236 struct pneigh_entry **phash_buckets;
237};
238
239enum {
240 NEIGH_ARP_TABLE = 0,
241 NEIGH_ND_TABLE = 1,
242 NEIGH_DN_TABLE = 2,
243 NEIGH_NR_TABLES,
244 NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
245};
246
247static inline int neigh_parms_family(struct neigh_parms *p)
248{
249 return p->tbl->family;
250}
251
252#define NEIGH_PRIV_ALIGN sizeof(long long)
253#define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN)
254
255static inline void *neighbour_priv(const struct neighbour *n)
256{
257 return (char *)n + n->tbl->entry_size;
258}
259
260/* flags for neigh_update() */
261#define NEIGH_UPDATE_F_OVERRIDE BIT(0)
262#define NEIGH_UPDATE_F_WEAK_OVERRIDE BIT(1)
263#define NEIGH_UPDATE_F_OVERRIDE_ISROUTER BIT(2)
264#define NEIGH_UPDATE_F_USE BIT(3)
265#define NEIGH_UPDATE_F_MANAGED BIT(4)
266#define NEIGH_UPDATE_F_EXT_LEARNED BIT(5)
267#define NEIGH_UPDATE_F_ISROUTER BIT(6)
268#define NEIGH_UPDATE_F_ADMIN BIT(7)
269
270/* In-kernel representation for NDA_FLAGS_EXT flags: */
271#define NTF_OLD_MASK 0xff
272#define NTF_EXT_SHIFT 8
273#define NTF_EXT_MASK (NTF_EXT_MANAGED)
274
275#define NTF_MANAGED (NTF_EXT_MANAGED << NTF_EXT_SHIFT)
276
277extern const struct nla_policy nda_policy[];
278
279static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey)
280{
281 return *(const u32 *)n->primary_key == *(const u32 *)pkey;
282}
283
284static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey)
285{
286 const u32 *n32 = (const u32 *)n->primary_key;
287 const u32 *p32 = pkey;
288
289 return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
290 (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0;
291}
292
293static inline struct neighbour *___neigh_lookup_noref(
294 struct neigh_table *tbl,
295 bool (*key_eq)(const struct neighbour *n, const void *pkey),
296 __u32 (*hash)(const void *pkey,
297 const struct net_device *dev,
298 __u32 *hash_rnd),
299 const void *pkey,
300 struct net_device *dev)
301{
302 struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht);
303 struct neighbour *n;
304 u32 hash_val;
305
306 hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
307 for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
308 n != NULL;
309 n = rcu_dereference_bh(n->next)) {
310 if (n->dev == dev && key_eq(n, pkey))
311 return n;
312 }
313
314 return NULL;
315}
316
317static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl,
318 const void *pkey,
319 struct net_device *dev)
320{
321 return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
322}
323
324static inline void neigh_confirm(struct neighbour *n)
325{
326 if (n) {
327 unsigned long now = jiffies;
328
329 /* avoid dirtying neighbour */
330 if (READ_ONCE(n->confirmed) != now)
331 WRITE_ONCE(n->confirmed, now);
332 }
333}
334
335void neigh_table_init(int index, struct neigh_table *tbl);
336int neigh_table_clear(int index, struct neigh_table *tbl);
337struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
338 struct net_device *dev);
339struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
340 const void *pkey);
341struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
342 struct net_device *dev, bool want_ref);
343static inline struct neighbour *neigh_create(struct neigh_table *tbl,
344 const void *pkey,
345 struct net_device *dev)
346{
347 return __neigh_create(tbl, pkey, dev, true);
348}
349void neigh_destroy(struct neighbour *neigh);
350int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb,
351 const bool immediate_ok);
352int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
353 u32 nlmsg_pid);
354void __neigh_set_probe_once(struct neighbour *neigh);
355bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
356void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
357int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
358int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev);
359int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
360int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
361int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
362struct neighbour *neigh_event_ns(struct neigh_table *tbl,
363 u8 *lladdr, void *saddr,
364 struct net_device *dev);
365
366struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
367 struct neigh_table *tbl);
368void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
369
370static inline
371struct net *neigh_parms_net(const struct neigh_parms *parms)
372{
373 return read_pnet(&parms->net);
374}
375
376unsigned long neigh_rand_reach_time(unsigned long base);
377
378void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
379 struct sk_buff *skb);
380struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
381 const void *key, struct net_device *dev,
382 int creat);
383struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
384 const void *key, struct net_device *dev);
385int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
386 struct net_device *dev);
387
388static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
389{
390 return read_pnet(&pneigh->net);
391}
392
393void neigh_app_ns(struct neighbour *n);
394void neigh_for_each(struct neigh_table *tbl,
395 void (*cb)(struct neighbour *, void *), void *cookie);
396void __neigh_for_each_release(struct neigh_table *tbl,
397 int (*cb)(struct neighbour *));
398int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *);
399void pneigh_for_each(struct neigh_table *tbl,
400 void (*cb)(struct pneigh_entry *));
401
402struct neigh_seq_state {
403 struct seq_net_private p;
404 struct neigh_table *tbl;
405 struct neigh_hash_table *nht;
406 void *(*neigh_sub_iter)(struct neigh_seq_state *state,
407 struct neighbour *n, loff_t *pos);
408 unsigned int bucket;
409 unsigned int flags;
410#define NEIGH_SEQ_NEIGH_ONLY 0x00000001
411#define NEIGH_SEQ_IS_PNEIGH 0x00000002
412#define NEIGH_SEQ_SKIP_NOARP 0x00000004
413};
414void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
415 unsigned int);
416void *neigh_seq_next(struct seq_file *, void *, loff_t *);
417void neigh_seq_stop(struct seq_file *, void *);
418
419int neigh_proc_dointvec(struct ctl_table *ctl, int write,
420 void *buffer, size_t *lenp, loff_t *ppos);
421int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
422 void *buffer,
423 size_t *lenp, loff_t *ppos);
424int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
425 void *buffer, size_t *lenp, loff_t *ppos);
426
427int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
428 proc_handler *proc_handler);
429void neigh_sysctl_unregister(struct neigh_parms *p);
430
431static inline void __neigh_parms_put(struct neigh_parms *parms)
432{
433 refcount_dec(&parms->refcnt);
434}
435
436static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
437{
438 refcount_inc(&parms->refcnt);
439 return parms;
440}
441
442/*
443 * Neighbour references
444 */
445
446static inline void neigh_release(struct neighbour *neigh)
447{
448 if (refcount_dec_and_test(&neigh->refcnt))
449 neigh_destroy(neigh);
450}
451
452static inline struct neighbour * neigh_clone(struct neighbour *neigh)
453{
454 if (neigh)
455 refcount_inc(&neigh->refcnt);
456 return neigh;
457}
458
459#define neigh_hold(n) refcount_inc(&(n)->refcnt)
460
461static __always_inline int neigh_event_send_probe(struct neighbour *neigh,
462 struct sk_buff *skb,
463 const bool immediate_ok)
464{
465 unsigned long now = jiffies;
466
467 if (READ_ONCE(neigh->used) != now)
468 WRITE_ONCE(neigh->used, now);
469 if (!(neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE)))
470 return __neigh_event_send(neigh, skb, immediate_ok);
471 return 0;
472}
473
474static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
475{
476 return neigh_event_send_probe(neigh, skb, true);
477}
478
479#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
480static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
481{
482 unsigned int seq, hh_alen;
483
484 do {
485 seq = read_seqbegin(&hh->hh_lock);
486 hh_alen = HH_DATA_ALIGN(ETH_HLEN);
487 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
488 } while (read_seqretry(&hh->hh_lock, seq));
489 return 0;
490}
491#endif
492
493static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
494{
495 unsigned int hh_alen = 0;
496 unsigned int seq;
497 unsigned int hh_len;
498
499 do {
500 seq = read_seqbegin(&hh->hh_lock);
501 hh_len = READ_ONCE(hh->hh_len);
502 if (likely(hh_len <= HH_DATA_MOD)) {
503 hh_alen = HH_DATA_MOD;
504
505 /* skb_push() would proceed silently if we have room for
506 * the unaligned size but not for the aligned size:
507 * check headroom explicitly.
508 */
509 if (likely(skb_headroom(skb) >= HH_DATA_MOD)) {
510 /* this is inlined by gcc */
511 memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
512 HH_DATA_MOD);
513 }
514 } else {
515 hh_alen = HH_DATA_ALIGN(hh_len);
516
517 if (likely(skb_headroom(skb) >= hh_alen)) {
518 memcpy(skb->data - hh_alen, hh->hh_data,
519 hh_alen);
520 }
521 }
522 } while (read_seqretry(&hh->hh_lock, seq));
523
524 if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) {
525 kfree_skb(skb);
526 return NET_XMIT_DROP;
527 }
528
529 __skb_push(skb, hh_len);
530 return dev_queue_xmit(skb);
531}
532
533static inline int neigh_output(struct neighbour *n, struct sk_buff *skb,
534 bool skip_cache)
535{
536 const struct hh_cache *hh = &n->hh;
537
538 /* n->nud_state and hh->hh_len could be changed under us.
539 * neigh_hh_output() is taking care of the race later.
540 */
541 if (!skip_cache &&
542 (READ_ONCE(n->nud_state) & NUD_CONNECTED) &&
543 READ_ONCE(hh->hh_len))
544 return neigh_hh_output(hh, skb);
545
546 return n->output(n, skb);
547}
548
549static inline struct neighbour *
550__neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
551{
552 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
553
554 if (n || !creat)
555 return n;
556
557 n = neigh_create(tbl, pkey, dev);
558 return IS_ERR(n) ? NULL : n;
559}
560
561static inline struct neighbour *
562__neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
563 struct net_device *dev)
564{
565 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
566
567 if (n)
568 return n;
569
570 return neigh_create(tbl, pkey, dev);
571}
572
573struct neighbour_cb {
574 unsigned long sched_next;
575 unsigned int flags;
576};
577
578#define LOCALLY_ENQUEUED 0x1
579
580#define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
581
582static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
583 const struct net_device *dev)
584{
585 unsigned int seq;
586
587 do {
588 seq = read_seqbegin(&n->ha_lock);
589 memcpy(dst, n->ha, dev->addr_len);
590 } while (read_seqretry(&n->ha_lock, seq));
591}
592
593static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags,
594 int *notify)
595{
596 u8 ndm_flags = 0;
597
598 ndm_flags |= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0;
599 if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) {
600 if (ndm_flags & NTF_ROUTER)
601 neigh->flags |= NTF_ROUTER;
602 else
603 neigh->flags &= ~NTF_ROUTER;
604 *notify = 1;
605 }
606}
607#endif