include/net/neighbour.h

   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         netdevice_tracker dev_tracker;
  74         struct list_head list;
  75         int     (*neigh_setup)(struct neighbour *);
  76         struct neigh_table *tbl;
  77
  78         void    *sysctl_table;
  79
  80         int dead;
  81         refcount_t refcnt;
  82         struct rcu_head rcu_head;
  83
  84         int     reachable_time;
  85         int     data[NEIGH_VAR_DATA_MAX];
  86         DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX);
  87 };
  88
  89 static inline void neigh_var_set(struct neigh_parms *p, int index, int val)
  90 {
  91         set_bit(index, p->data_state);
  92         p->data[index] = val;
  93 }
  94
  95 #define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr])
  96
  97 /* In ndo_neigh_setup, NEIGH_VAR_INIT should be used.
  98  * In other cases, NEIGH_VAR_SET should be used.
  99  */
 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)
 102
 103 static inline void neigh_parms_data_state_setall(struct neigh_parms *p)
 104 {
 105         bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX);
 106 }
 107
 108 static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p)
 109 {
 110         bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX);
 111 }
 112
 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 */
 117
 118         unsigned long res_failed;       /* number of failed resolutions */
 119
 120         unsigned long lookups;          /* number of lookups */
 121         unsigned long hits;             /* number of hits (among lookups) */
 122
 123         unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
 124         unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
 125
 126         unsigned long periodic_gc_runs; /* number of periodic GC runs */
 127         unsigned long forced_gc_runs;   /* number of forced GC runs */
 128
 129         unsigned long unres_discards;   /* number of unresolved drops */
 130         unsigned long table_fulls;      /* times even gc couldn't help */
 131 };
 132
 133 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
 134
 135 struct neighbour {
 136         struct neighbour __rcu  *next;
 137         struct neigh_table      *tbl;
 138         struct neigh_parms      *parms;
 139         unsigned long           confirmed;
 140         unsigned long           updated;
 141         rwlock_t                lock;
 142         refcount_t              refcnt;
 143         unsigned int            arp_queue_len_bytes;
 144         struct sk_buff_head     arp_queue;
 145         struct timer_list       timer;
 146         unsigned long           used;
 147         atomic_t                probes;
 148         u8                      nud_state;
 149         u8                      type;
 150         u8                      dead;
 151         u8                      protocol;
 152         u32                     flags;
 153         seqlock_t               ha_lock;
 154         unsigned char           ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))] __aligned(8);
 155         struct hh_cache         hh;
 156         int                     (*output)(struct neighbour *, struct sk_buff *);
 157         const struct neigh_ops  *ops;
 158         struct list_head        gc_list;
 159         struct list_head        managed_list;
 160         struct rcu_head         rcu;
 161         struct net_device       *dev;
 162         netdevice_tracker       dev_tracker;
 163         u8                      primary_key[0];
 164 } __randomize_layout;
 165
 166 struct neigh_ops {
 167         int                     family;
 168         void                    (*solicit)(struct neighbour *, struct sk_buff *);
 169         void                    (*error_report)(struct neighbour *, struct sk_buff *);
 170         int                     (*output)(struct neighbour *, struct sk_buff *);
 171         int                     (*connected_output)(struct neighbour *, struct sk_buff *);
 172 };
 173
 174 struct pneigh_entry {
 175         struct pneigh_entry     *next;
 176         possible_net_t          net;
 177         struct net_device       *dev;
 178         netdevice_tracker       dev_tracker;
 179         u32                     flags;
 180         u8                      protocol;
 181         u8                      key[];
 182 };
 183
 184 /*
 185  *      neighbour table manipulation
 186  */
 187
 188 #define NEIGH_NUM_HASH_RND      4
 189
 190 struct neigh_hash_table {
 191         struct neighbour __rcu  **hash_buckets;
 192         unsigned int            hash_shift;
 193         __u32                   hash_rnd[NEIGH_NUM_HASH_RND];
 194         struct rcu_head         rcu;
 195 };
 196
 197
 198 struct neigh_table {
 199         int                     family;
 200         unsigned int            entry_size;
 201         unsigned int            key_len;
 202         __be16                  protocol;
 203         __u32                   (*hash)(const void *pkey,
 204                                         const struct net_device *dev,
 205                                         __u32 *hash_rnd);
 206         bool                    (*key_eq)(const struct neighbour *, const void *pkey);
 207         int                     (*constructor)(struct neighbour *);
 208         int                     (*pconstructor)(struct pneigh_entry *);
 209         void                    (*pdestructor)(struct pneigh_entry *);
 210         void                    (*proxy_redo)(struct sk_buff *skb);
 211         int                     (*is_multicast)(const void *pkey);
 212         bool                    (*allow_add)(const struct net_device *dev,
 213                                              struct netlink_ext_ack *extack);
 214         char                    *id;
 215         struct neigh_parms      parms;
 216         struct list_head        parms_list;
 217         int                     gc_interval;
 218         int                     gc_thresh1;
 219         int                     gc_thresh2;
 220         int                     gc_thresh3;
 221         unsigned long           last_flush;
 222         struct delayed_work     gc_work;
 223         struct delayed_work     managed_work;
 224         struct timer_list       proxy_timer;
 225         struct sk_buff_head     proxy_queue;
 226         atomic_t                entries;
 227         atomic_t                gc_entries;
 228         struct list_head        gc_list;
 229         struct list_head        managed_list;
 230         rwlock_t                lock;
 231         unsigned long           last_rand;
 232         struct neigh_statistics __percpu *stats;
 233         struct neigh_hash_table __rcu *nht;
 234         struct pneigh_entry     **phash_buckets;
 235 };
 236
 237 enum {
 238         NEIGH_ARP_TABLE = 0,
 239         NEIGH_ND_TABLE = 1,
 240         NEIGH_DN_TABLE = 2,
 241         NEIGH_NR_TABLES,
 242         NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */
 243 };
 244
 245 static inline int neigh_parms_family(struct neigh_parms *p)
 246 {
 247         return p->tbl->family;
 248 }
 249
 250 #define NEIGH_PRIV_ALIGN        sizeof(long long)
 251 #define NEIGH_ENTRY_SIZE(size)  ALIGN((size), NEIGH_PRIV_ALIGN)
 252
 253 static inline void *neighbour_priv(const struct neighbour *n)
 254 {
 255         return (char *)n + n->tbl->entry_size;
 256 }
 257
 258 /* flags for neigh_update() */
 259 #define NEIGH_UPDATE_F_OVERRIDE                 BIT(0)
 260 #define NEIGH_UPDATE_F_WEAK_OVERRIDE            BIT(1)
 261 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        BIT(2)
 262 #define NEIGH_UPDATE_F_USE                      BIT(3)
 263 #define NEIGH_UPDATE_F_MANAGED                  BIT(4)
 264 #define NEIGH_UPDATE_F_EXT_LEARNED              BIT(5)
 265 #define NEIGH_UPDATE_F_ISROUTER                 BIT(6)
 266 #define NEIGH_UPDATE_F_ADMIN                    BIT(7)
 267
 268 /* In-kernel representation for NDA_FLAGS_EXT flags: */
 269 #define NTF_OLD_MASK            0xff
 270 #define NTF_EXT_SHIFT           8
 271 #define NTF_EXT_MASK            (NTF_EXT_MANAGED)
 272
 273 #define NTF_MANAGED             (NTF_EXT_MANAGED << NTF_EXT_SHIFT)
 274
 275 extern const struct nla_policy nda_policy[];
 276
 277 static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey)
 278 {
 279         return *(const u16 *)n->primary_key == *(const u16 *)pkey;
 280 }
 281
 282 static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey)
 283 {
 284         return *(const u32 *)n->primary_key == *(const u32 *)pkey;
 285 }
 286
 287 static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey)
 288 {
 289         const u32 *n32 = (const u32 *)n->primary_key;
 290         const u32 *p32 = pkey;
 291
 292         return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
 293                 (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0;
 294 }
 295
 296 static inline struct neighbour *___neigh_lookup_noref(
 297         struct neigh_table *tbl,
 298         bool (*key_eq)(const struct neighbour *n, const void *pkey),
 299         __u32 (*hash)(const void *pkey,
 300                       const struct net_device *dev,
 301                       __u32 *hash_rnd),
 302         const void *pkey,
 303         struct net_device *dev)
 304 {
 305         struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht);
 306         struct neighbour *n;
 307         u32 hash_val;
 308
 309         hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
 310         for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
 311              n != NULL;
 312              n = rcu_dereference_bh(n->next)) {
 313                 if (n->dev == dev && key_eq(n, pkey))
 314                         return n;
 315         }
 316
 317         return NULL;
 318 }
 319
 320 static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl,
 321                                                      const void *pkey,
 322                                                      struct net_device *dev)
 323 {
 324         return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
 325 }
 326
 327 static inline void neigh_confirm(struct neighbour *n)
 328 {
 329         if (n) {
 330                 unsigned long now = jiffies;
 331
 332                 /* avoid dirtying neighbour */
 333                 if (READ_ONCE(n->confirmed) != now)
 334                         WRITE_ONCE(n->confirmed, now);
 335         }
 336 }
 337
 338 void neigh_table_init(int index, struct neigh_table *tbl);
 339 int neigh_table_clear(int index, struct neigh_table *tbl);
 340 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
 341                                struct net_device *dev);
 342 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
 343                                      const void *pkey);
 344 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
 345                                  struct net_device *dev, bool want_ref);
 346 static inline struct neighbour *neigh_create(struct neigh_table *tbl,
 347                                              const void *pkey,
 348                                              struct net_device *dev)
 349 {
 350         return __neigh_create(tbl, pkey, dev, true);
 351 }
 352 void neigh_destroy(struct neighbour *neigh);
 353 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb,
 354                        const bool immediate_ok);
 355 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
 356                  u32 nlmsg_pid);
 357 void __neigh_set_probe_once(struct neighbour *neigh);
 358 bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
 359 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 360 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 361 int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev);
 362 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
 363 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
 364 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
 365 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
 366                                                 u8 *lladdr, void *saddr,
 367                                                 struct net_device *dev);
 368
 369 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
 370                                       struct neigh_table *tbl);
 371 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
 372
 373 static inline
 374 struct net *neigh_parms_net(const struct neigh_parms *parms)
 375 {
 376         return read_pnet(&parms->net);
 377 }
 378
 379 unsigned long neigh_rand_reach_time(unsigned long base);
 380
 381 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 382                     struct sk_buff *skb);
 383 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net,
 384                                    const void *key, struct net_device *dev,
 385                                    int creat);
 386 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net,
 387                                      const void *key, struct net_device *dev);
 388 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key,
 389                   struct net_device *dev);
 390
 391 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh)
 392 {
 393         return read_pnet(&pneigh->net);
 394 }
 395
 396 void neigh_app_ns(struct neighbour *n);
 397 void neigh_for_each(struct neigh_table *tbl,
 398                     void (*cb)(struct neighbour *, void *), void *cookie);
 399 void __neigh_for_each_release(struct neigh_table *tbl,
 400                               int (*cb)(struct neighbour *));
 401 int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *);
 402 void pneigh_for_each(struct neigh_table *tbl,
 403                      void (*cb)(struct pneigh_entry *));
 404
 405 struct neigh_seq_state {
 406         struct seq_net_private p;
 407         struct neigh_table *tbl;
 408         struct neigh_hash_table *nht;
 409         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 410                                 struct neighbour *n, loff_t *pos);
 411         unsigned int bucket;
 412         unsigned int flags;
 413 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 414 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
 415 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
 416 };
 417 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *,
 418                       unsigned int);
 419 void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 420 void neigh_seq_stop(struct seq_file *, void *);
 421
 422 int neigh_proc_dointvec(struct ctl_table *ctl, int write,
 423                         void *buffer, size_t *lenp, loff_t *ppos);
 424 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
 425                                 void *buffer,
 426                                 size_t *lenp, loff_t *ppos);
 427 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
 428                                    void *buffer, size_t *lenp, loff_t *ppos);
 429
 430 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
 431                           proc_handler *proc_handler);
 432 void neigh_sysctl_unregister(struct neigh_parms *p);
 433
 434 static inline void __neigh_parms_put(struct neigh_parms *parms)
 435 {
 436         refcount_dec(&parms->refcnt);
 437 }
 438
 439 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 440 {
 441         refcount_inc(&parms->refcnt);
 442         return parms;
 443 }
 444
 445 /*
 446  *      Neighbour references
 447  */
 448
 449 static inline void neigh_release(struct neighbour *neigh)
 450 {
 451         if (refcount_dec_and_test(&neigh->refcnt))
 452                 neigh_destroy(neigh);
 453 }
 454
 455 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 456 {
 457         if (neigh)
 458                 refcount_inc(&neigh->refcnt);
 459         return neigh;
 460 }
 461
 462 #define neigh_hold(n)   refcount_inc(&(n)->refcnt)
 463
 464 static __always_inline int neigh_event_send_probe(struct neighbour *neigh,
 465                                                   struct sk_buff *skb,
 466                                                   const bool immediate_ok)
 467 {
 468         unsigned long now = jiffies;
 469
 470         if (READ_ONCE(neigh->used) != now)
 471                 WRITE_ONCE(neigh->used, now);
 472         if (!(neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE)))
 473                 return __neigh_event_send(neigh, skb, immediate_ok);
 474         return 0;
 475 }
 476
 477 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 478 {
 479         return neigh_event_send_probe(neigh, skb, true);
 480 }
 481
 482 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 483 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
 484 {
 485         unsigned int seq, hh_alen;
 486
 487         do {
 488                 seq = read_seqbegin(&hh->hh_lock);
 489                 hh_alen = HH_DATA_ALIGN(ETH_HLEN);
 490                 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
 491         } while (read_seqretry(&hh->hh_lock, seq));
 492         return 0;
 493 }
 494 #endif
 495
 496 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
 497 {
 498         unsigned int hh_alen = 0;
 499         unsigned int seq;
 500         unsigned int hh_len;
 501
 502         do {
 503                 seq = read_seqbegin(&hh->hh_lock);
 504                 hh_len = READ_ONCE(hh->hh_len);
 505                 if (likely(hh_len <= HH_DATA_MOD)) {
 506                         hh_alen = HH_DATA_MOD;
 507
 508                         /* skb_push() would proceed silently if we have room for
 509                          * the unaligned size but not for the aligned size:
 510                          * check headroom explicitly.
 511                          */
 512                         if (likely(skb_headroom(skb) >= HH_DATA_MOD)) {
 513                                 /* this is inlined by gcc */
 514                                 memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
 515                                        HH_DATA_MOD);
 516                         }
 517                 } else {
 518                         hh_alen = HH_DATA_ALIGN(hh_len);
 519
 520                         if (likely(skb_headroom(skb) >= hh_alen)) {
 521                                 memcpy(skb->data - hh_alen, hh->hh_data,
 522                                        hh_alen);
 523                         }
 524                 }
 525         } while (read_seqretry(&hh->hh_lock, seq));
 526
 527         if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) {
 528                 kfree_skb(skb);
 529                 return NET_XMIT_DROP;
 530         }
 531
 532         __skb_push(skb, hh_len);
 533         return dev_queue_xmit(skb);
 534 }
 535
 536 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb,
 537                                bool skip_cache)
 538 {
 539         const struct hh_cache *hh = &n->hh;
 540
 541         /* n->nud_state and hh->hh_len could be changed under us.
 542          * neigh_hh_output() is taking care of the race later.
 543          */
 544         if (!skip_cache &&
 545             (READ_ONCE(n->nud_state) & NUD_CONNECTED) &&
 546             READ_ONCE(hh->hh_len))
 547                 return neigh_hh_output(hh, skb);
 548
 549         return n->output(n, skb);
 550 }
 551
 552 static inline struct neighbour *
 553 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 554 {
 555         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 556
 557         if (n || !creat)
 558                 return n;
 559
 560         n = neigh_create(tbl, pkey, dev);
 561         return IS_ERR(n) ? NULL : n;
 562 }
 563
 564 static inline struct neighbour *
 565 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 566   struct net_device *dev)
 567 {
 568         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 569
 570         if (n)
 571                 return n;
 572
 573         return neigh_create(tbl, pkey, dev);
 574 }
 575
 576 struct neighbour_cb {
 577         unsigned long sched_next;
 578         unsigned int flags;
 579 };
 580
 581 #define LOCALLY_ENQUEUED 0x1
 582
 583 #define NEIGH_CB(skb)   ((struct neighbour_cb *)(skb)->cb)
 584
 585 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
 586                                      const struct net_device *dev)
 587 {
 588         unsigned int seq;
 589
 590         do {
 591                 seq = read_seqbegin(&n->ha_lock);
 592                 memcpy(dst, n->ha, dev->addr_len);
 593         } while (read_seqretry(&n->ha_lock, seq));
 594 }
 595
 596 static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags,
 597                                           int *notify)
 598 {
 599         u8 ndm_flags = 0;
 600
 601         ndm_flags |= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0;
 602         if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) {
 603                 if (ndm_flags & NTF_ROUTER)
 604                         neigh->flags |= NTF_ROUTER;
 605                 else
 606                         neigh->flags &= ~NTF_ROUTER;
 607                 *notify = 1;
 608         }
 609 }
 610 #endif