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
41 struct neighbour;
42
43 enum {
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
70 struct 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
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 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
134 struct 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 nud_state;
148 u8 type;
149 u8 dead;
150 u8 protocol;
151 u32 flags;
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 list_head managed_list;
159 struct rcu_head rcu;
160 struct net_device *dev;
161 u8 primary_key[0];
162 } __randomize_layout;
163
164 struct neigh_ops {
165 int family;
166 void (*solicit)(struct neighbour *, struct sk_buff *);
167 void (*error_report)(struct neighbour *, struct sk_buff *);
168 int (*output)(struct neighbour *, struct sk_buff *);
169 int (*connected_output)(struct neighbour *, struct sk_buff *);
170 };
171
172 struct pneigh_entry {
173 struct pneigh_entry *next;
174 possible_net_t net;
175 struct net_device *dev;
176 u32 flags;
177 u8 protocol;
178 u8 key[];
179 };
180
181 /*
182 * neighbour table manipulation
183 */
184
185 #define NEIGH_NUM_HASH_RND 4
186
187 struct neigh_hash_table {
188 struct neighbour __rcu **hash_buckets;
189 unsigned int hash_shift;
190 __u32 hash_rnd[NEIGH_NUM_HASH_RND];
191 struct rcu_head rcu;
192 };
193
194
195 struct neigh_table {
196 int family;
197 unsigned int entry_size;
198 unsigned int key_len;
199 __be16 protocol;
200 __u32 (*hash)(const void *pkey,
201 const struct net_device *dev,
202 __u32 *hash_rnd);
203 bool (*key_eq)(const struct neighbour *, const void *pkey);
204 int (*constructor)(struct neighbour *);
205 int (*pconstructor)(struct pneigh_entry *);
206 void (*pdestructor)(struct pneigh_entry *);
207 void (*proxy_redo)(struct sk_buff *skb);
208 int (*is_multicast)(const void *pkey);
209 bool (*allow_add)(const struct net_device *dev,
210 struct netlink_ext_ack *extack);
211 char *id;
212 struct neigh_parms parms;
213 struct list_head parms_list;
214 int gc_interval;
215 int gc_thresh1;
216 int gc_thresh2;
217 int gc_thresh3;
218 unsigned long last_flush;
219 struct delayed_work gc_work;
220 struct delayed_work managed_work;
221 struct timer_list proxy_timer;
222 struct sk_buff_head proxy_queue;
223 atomic_t entries;
224 atomic_t gc_entries;
225 struct list_head gc_list;
226 struct list_head managed_list;
227 rwlock_t lock;
228 unsigned long last_rand;
229 struct neigh_statistics __percpu *stats;
230 struct neigh_hash_table __rcu *nht;
231 struct pneigh_entry **phash_buckets;
232 };
233
234 enum {
235 NEIGH_ARP_TABLE = 0,
236 NEIGH_ND_TABLE = 1,
237 NEIGH_DN_TABLE = 2,
238 NEIGH_NR_TABLES,
239 NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
240 };
241
neigh_parms_family(struct neigh_parms * p)242 static inline int neigh_parms_family(struct neigh_parms *p)
243 {
244 return p->tbl->family;
245 }
246
247 #define NEIGH_PRIV_ALIGN sizeof(long long)
248 #define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN)
249
neighbour_priv(const struct neighbour * n)250 static inline void *neighbour_priv(const struct neighbour *n)
251 {
252 return (char *)n + n->tbl->entry_size;
253 }
254
255 /* flags for neigh_update() */
256 #define NEIGH_UPDATE_F_OVERRIDE BIT(0)
257 #define NEIGH_UPDATE_F_WEAK_OVERRIDE BIT(1)
258 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER BIT(2)
259 #define NEIGH_UPDATE_F_USE BIT(3)
260 #define NEIGH_UPDATE_F_MANAGED BIT(4)
261 #define NEIGH_UPDATE_F_EXT_LEARNED BIT(5)
262 #define NEIGH_UPDATE_F_ISROUTER BIT(6)
263 #define NEIGH_UPDATE_F_ADMIN BIT(7)
264
265 /* In-kernel representation for NDA_FLAGS_EXT flags: */
266 #define NTF_OLD_MASK 0xff
267 #define NTF_EXT_SHIFT 8
268 #define NTF_EXT_MASK (NTF_EXT_MANAGED)
269
270 #define NTF_MANAGED (NTF_EXT_MANAGED << NTF_EXT_SHIFT)
271
272 extern const struct nla_policy nda_policy[];
273
neigh_key_eq16(const struct neighbour * n,const void * pkey)274 static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey)
275 {
276 return *(const u16 *)n->primary_key == *(const u16 *)pkey;
277 }
278
neigh_key_eq32(const struct neighbour * n,const void * pkey)279 static 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
neigh_key_eq128(const struct neighbour * n,const void * pkey)284 static 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
___neigh_lookup_noref(struct neigh_table * tbl,bool (* key_eq)(const struct neighbour * n,const void * pkey),__u32 (* hash)(const void * pkey,const struct net_device * dev,__u32 * hash_rnd),const void * pkey,struct net_device * dev)293 static 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
__neigh_lookup_noref(struct neigh_table * tbl,const void * pkey,struct net_device * dev)317 static 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
324 void neigh_table_init(int index, struct neigh_table *tbl);
325 int neigh_table_clear(int index, struct neigh_table *tbl);
326 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
327 struct net_device *dev);
328 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
329 const void *pkey);
330 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
331 struct net_device *dev, bool want_ref);
neigh_create(struct neigh_table * tbl,const void * pkey,struct net_device * dev)332 static inline struct neighbour *neigh_create(struct neigh_table *tbl,
333 const void *pkey,
334 struct net_device *dev)
335 {
336 return __neigh_create(tbl, pkey, dev, true);
337 }
338 void neigh_destroy(struct neighbour *neigh);
339 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
340 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
341 u32 nlmsg_pid);
342 void __neigh_set_probe_once(struct neighbour *neigh);
343 bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
344 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
345 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
346 int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev);
347 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
348 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
349 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
350 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
351 u8 *lladdr, void *saddr,
352 struct net_device *dev);
353
354 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
355 struct neigh_table *tbl);
356 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
357
358 static inline
neigh_parms_net(const struct neigh_parms * parms)359 struct net *neigh_parms_net(const struct neigh_parms *parms)
360 {
361 return read_pnet(&parms->net);
362 }
363
364 unsigned long neigh_rand_reach_time(unsigned long base);
365
366 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
367 struct sk_buff *skb);
368 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
369 const void *key, struct net_device *dev,
370 int creat);
371 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
372 const void *key, struct net_device *dev);
373 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
374 struct net_device *dev);
375
pneigh_net(const struct pneigh_entry * pneigh)376 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
377 {
378 return read_pnet(&pneigh->net);
379 }
380
381 void neigh_app_ns(struct neighbour *n);
382 void neigh_for_each(struct neigh_table *tbl,
383 void (*cb)(struct neighbour *, void *), void *cookie);
384 void __neigh_for_each_release(struct neigh_table *tbl,
385 int (*cb)(struct neighbour *));
386 int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *);
387 void pneigh_for_each(struct neigh_table *tbl,
388 void (*cb)(struct pneigh_entry *));
389
390 struct neigh_seq_state {
391 struct seq_net_private p;
392 struct neigh_table *tbl;
393 struct neigh_hash_table *nht;
394 void *(*neigh_sub_iter)(struct neigh_seq_state *state,
395 struct neighbour *n, loff_t *pos);
396 unsigned int bucket;
397 unsigned int flags;
398 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001
399 #define NEIGH_SEQ_IS_PNEIGH 0x00000002
400 #define NEIGH_SEQ_SKIP_NOARP 0x00000004
401 };
402 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
403 unsigned int);
404 void *neigh_seq_next(struct seq_file *, void *, loff_t *);
405 void neigh_seq_stop(struct seq_file *, void *);
406
407 int neigh_proc_dointvec(struct ctl_table *ctl, int write,
408 void *buffer, size_t *lenp, loff_t *ppos);
409 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
410 void *buffer,
411 size_t *lenp, loff_t *ppos);
412 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
413 void *buffer, size_t *lenp, loff_t *ppos);
414
415 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
416 proc_handler *proc_handler);
417 void neigh_sysctl_unregister(struct neigh_parms *p);
418
__neigh_parms_put(struct neigh_parms * parms)419 static inline void __neigh_parms_put(struct neigh_parms *parms)
420 {
421 refcount_dec(&parms->refcnt);
422 }
423
neigh_parms_clone(struct neigh_parms * parms)424 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
425 {
426 refcount_inc(&parms->refcnt);
427 return parms;
428 }
429
430 /*
431 * Neighbour references
432 */
433
neigh_release(struct neighbour * neigh)434 static inline void neigh_release(struct neighbour *neigh)
435 {
436 if (refcount_dec_and_test(&neigh->refcnt))
437 neigh_destroy(neigh);
438 }
439
neigh_clone(struct neighbour * neigh)440 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
441 {
442 if (neigh)
443 refcount_inc(&neigh->refcnt);
444 return neigh;
445 }
446
447 #define neigh_hold(n) refcount_inc(&(n)->refcnt)
448
neigh_event_send(struct neighbour * neigh,struct sk_buff * skb)449 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
450 {
451 unsigned long now = jiffies;
452
453 if (READ_ONCE(neigh->used) != now)
454 WRITE_ONCE(neigh->used, now);
455 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
456 return __neigh_event_send(neigh, skb);
457 return 0;
458 }
459
460 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
neigh_hh_bridge(struct hh_cache * hh,struct sk_buff * skb)461 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
462 {
463 unsigned int seq, hh_alen;
464
465 do {
466 seq = read_seqbegin(&hh->hh_lock);
467 hh_alen = HH_DATA_ALIGN(ETH_HLEN);
468 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
469 } while (read_seqretry(&hh->hh_lock, seq));
470 return 0;
471 }
472 #endif
473
neigh_hh_output(const struct hh_cache * hh,struct sk_buff * skb)474 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
475 {
476 unsigned int hh_alen = 0;
477 unsigned int seq;
478 unsigned int hh_len;
479
480 do {
481 seq = read_seqbegin(&hh->hh_lock);
482 hh_len = READ_ONCE(hh->hh_len);
483 if (likely(hh_len <= HH_DATA_MOD)) {
484 hh_alen = HH_DATA_MOD;
485
486 /* skb_push() would proceed silently if we have room for
487 * the unaligned size but not for the aligned size:
488 * check headroom explicitly.
489 */
490 if (likely(skb_headroom(skb) >= HH_DATA_MOD)) {
491 /* this is inlined by gcc */
492 memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
493 HH_DATA_MOD);
494 }
495 } else {
496 hh_alen = HH_DATA_ALIGN(hh_len);
497
498 if (likely(skb_headroom(skb) >= hh_alen)) {
499 memcpy(skb->data - hh_alen, hh->hh_data,
500 hh_alen);
501 }
502 }
503 } while (read_seqretry(&hh->hh_lock, seq));
504
505 if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) {
506 kfree_skb(skb);
507 return NET_XMIT_DROP;
508 }
509
510 __skb_push(skb, hh_len);
511 return dev_queue_xmit(skb);
512 }
513
neigh_output(struct neighbour * n,struct sk_buff * skb,bool skip_cache)514 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb,
515 bool skip_cache)
516 {
517 const struct hh_cache *hh = &n->hh;
518
519 /* n->nud_state and hh->hh_len could be changed under us.
520 * neigh_hh_output() is taking care of the race later.
521 */
522 if (!skip_cache &&
523 (READ_ONCE(n->nud_state) & NUD_CONNECTED) &&
524 READ_ONCE(hh->hh_len))
525 return neigh_hh_output(hh, skb);
526
527 return n->output(n, skb);
528 }
529
530 static inline struct neighbour *
__neigh_lookup(struct neigh_table * tbl,const void * pkey,struct net_device * dev,int creat)531 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
532 {
533 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
534
535 if (n || !creat)
536 return n;
537
538 n = neigh_create(tbl, pkey, dev);
539 return IS_ERR(n) ? NULL : n;
540 }
541
542 static inline struct neighbour *
__neigh_lookup_errno(struct neigh_table * tbl,const void * pkey,struct net_device * dev)543 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
544 struct net_device *dev)
545 {
546 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
547
548 if (n)
549 return n;
550
551 return neigh_create(tbl, pkey, dev);
552 }
553
554 struct neighbour_cb {
555 unsigned long sched_next;
556 unsigned int flags;
557 };
558
559 #define LOCALLY_ENQUEUED 0x1
560
561 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
562
neigh_ha_snapshot(char * dst,const struct neighbour * n,const struct net_device * dev)563 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
564 const struct net_device *dev)
565 {
566 unsigned int seq;
567
568 do {
569 seq = read_seqbegin(&n->ha_lock);
570 memcpy(dst, n->ha, dev->addr_len);
571 } while (read_seqretry(&n->ha_lock, seq));
572 }
573
neigh_update_is_router(struct neighbour * neigh,u32 flags,int * notify)574 static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags,
575 int *notify)
576 {
577 u8 ndm_flags = 0;
578
579 ndm_flags |= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0;
580 if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) {
581 if (ndm_flags & NTF_ROUTER)
582 neigh->flags |= NTF_ROUTER;
583 else
584 neigh->flags &= ~NTF_ROUTER;
585 *notify = 1;
586 }
587 }
588 #endif
589