linux/include/net/neighbour.h
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   1#ifndef _NET_NEIGHBOUR_H
   2#define _NET_NEIGHBOUR_H
   3
   4#include <linux/neighbour.h>
   5
   6/*
   7 *      Generic neighbour manipulation
   8 *
   9 *      Authors:
  10 *      Pedro Roque             <roque@di.fc.ul.pt>
  11 *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
  12 *
  13 *      Changes:
  14 *
  15 *      Harald Welte:           <laforge@gnumonks.org>
  16 *              - Add neighbour cache statistics like rtstat
  17 */
  18
  19#include <asm/atomic.h>
  20#include <linux/netdevice.h>
  21#include <linux/skbuff.h>
  22#include <linux/rcupdate.h>
  23#include <linux/seq_file.h>
  24
  25#include <linux/err.h>
  26#include <linux/sysctl.h>
  27#include <linux/workqueue.h>
  28#include <net/rtnetlink.h>
  29
  30/*
  31 * NUD stands for "neighbor unreachability detection"
  32 */
  33
  34#define NUD_IN_TIMER    (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
  35#define NUD_VALID       (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
  36#define NUD_CONNECTED   (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
  37
  38struct neighbour;
  39
  40struct neigh_parms
  41{
  42#ifdef CONFIG_NET_NS
  43        struct net *net;
  44#endif
  45        struct net_device *dev;
  46        struct neigh_parms *next;
  47        int     (*neigh_setup)(struct neighbour *);
  48        void    (*neigh_cleanup)(struct neighbour *);
  49        struct neigh_table *tbl;
  50
  51        void    *sysctl_table;
  52
  53        int dead;
  54        atomic_t refcnt;
  55        struct rcu_head rcu_head;
  56
  57        int     base_reachable_time;
  58        int     retrans_time;
  59        int     gc_staletime;
  60        int     reachable_time;
  61        int     delay_probe_time;
  62
  63        int     queue_len;
  64        int     ucast_probes;
  65        int     app_probes;
  66        int     mcast_probes;
  67        int     anycast_delay;
  68        int     proxy_delay;
  69        int     proxy_qlen;
  70        int     locktime;
  71};
  72
  73struct neigh_statistics
  74{
  75        unsigned long allocs;           /* number of allocated neighs */
  76        unsigned long destroys;         /* number of destroyed neighs */
  77        unsigned long hash_grows;       /* number of hash resizes */
  78
  79        unsigned long res_failed;       /* number of failed resolutions */
  80
  81        unsigned long lookups;          /* number of lookups */
  82        unsigned long hits;             /* number of hits (among lookups) */
  83
  84        unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
  85        unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
  86
  87        unsigned long periodic_gc_runs; /* number of periodic GC runs */
  88        unsigned long forced_gc_runs;   /* number of forced GC runs */
  89
  90        unsigned long unres_discards;   /* number of unresolved drops */
  91};
  92
  93#define NEIGH_CACHE_STAT_INC(tbl, field)                                \
  94        do {                                                            \
  95                preempt_disable();                                      \
  96                (per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
  97                preempt_enable();                                       \
  98        } while (0)
  99
 100struct neighbour
 101{
 102        struct neighbour        *next;
 103        struct neigh_table      *tbl;
 104        struct neigh_parms      *parms;
 105        struct net_device               *dev;
 106        unsigned long           used;
 107        unsigned long           confirmed;
 108        unsigned long           updated;
 109        __u8                    flags;
 110        __u8                    nud_state;
 111        __u8                    type;
 112        __u8                    dead;
 113        atomic_t                probes;
 114        rwlock_t                lock;
 115        unsigned char           ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
 116        struct hh_cache         *hh;
 117        atomic_t                refcnt;
 118        int                     (*output)(struct sk_buff *skb);
 119        struct sk_buff_head     arp_queue;
 120        struct timer_list       timer;
 121        const struct neigh_ops  *ops;
 122        u8                      primary_key[0];
 123};
 124
 125struct neigh_ops
 126{
 127        int                     family;
 128        void                    (*solicit)(struct neighbour *, struct sk_buff*);
 129        void                    (*error_report)(struct neighbour *, struct sk_buff*);
 130        int                     (*output)(struct sk_buff*);
 131        int                     (*connected_output)(struct sk_buff*);
 132        int                     (*hh_output)(struct sk_buff*);
 133        int                     (*queue_xmit)(struct sk_buff*);
 134};
 135
 136struct pneigh_entry
 137{
 138        struct pneigh_entry     *next;
 139#ifdef CONFIG_NET_NS
 140        struct net              *net;
 141#endif
 142        struct net_device       *dev;
 143        u8                      flags;
 144        u8                      key[0];
 145};
 146
 147/*
 148 *      neighbour table manipulation
 149 */
 150
 151
 152struct neigh_table
 153{
 154        struct neigh_table      *next;
 155        int                     family;
 156        int                     entry_size;
 157        int                     key_len;
 158        __u32                   (*hash)(const void *pkey, const struct net_device *);
 159        int                     (*constructor)(struct neighbour *);
 160        int                     (*pconstructor)(struct pneigh_entry *);
 161        void                    (*pdestructor)(struct pneigh_entry *);
 162        void                    (*proxy_redo)(struct sk_buff *skb);
 163        char                    *id;
 164        struct neigh_parms      parms;
 165        /* HACK. gc_* shoul follow parms without a gap! */
 166        int                     gc_interval;
 167        int                     gc_thresh1;
 168        int                     gc_thresh2;
 169        int                     gc_thresh3;
 170        unsigned long           last_flush;
 171        struct delayed_work     gc_work;
 172        struct timer_list       proxy_timer;
 173        struct sk_buff_head     proxy_queue;
 174        atomic_t                entries;
 175        rwlock_t                lock;
 176        unsigned long           last_rand;
 177        struct kmem_cache               *kmem_cachep;
 178        struct neigh_statistics *stats;
 179        struct neighbour        **hash_buckets;
 180        unsigned int            hash_mask;
 181        __u32                   hash_rnd;
 182        struct pneigh_entry     **phash_buckets;
 183};
 184
 185/* flags for neigh_update() */
 186#define NEIGH_UPDATE_F_OVERRIDE                 0x00000001
 187#define NEIGH_UPDATE_F_WEAK_OVERRIDE            0x00000002
 188#define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        0x00000004
 189#define NEIGH_UPDATE_F_ISROUTER                 0x40000000
 190#define NEIGH_UPDATE_F_ADMIN                    0x80000000
 191
 192extern void                     neigh_table_init(struct neigh_table *tbl);
 193extern void                     neigh_table_init_no_netlink(struct neigh_table *tbl);
 194extern int                      neigh_table_clear(struct neigh_table *tbl);
 195extern struct neighbour *       neigh_lookup(struct neigh_table *tbl,
 196                                             const void *pkey,
 197                                             struct net_device *dev);
 198extern struct neighbour *       neigh_lookup_nodev(struct neigh_table *tbl,
 199                                                   struct net *net,
 200                                                   const void *pkey);
 201extern struct neighbour *       neigh_create(struct neigh_table *tbl,
 202                                             const void *pkey,
 203                                             struct net_device *dev);
 204extern void                     neigh_destroy(struct neighbour *neigh);
 205extern int                      __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
 206extern int                      neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 
 207                                             u32 flags);
 208extern void                     neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 209extern int                      neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 210extern int                      neigh_resolve_output(struct sk_buff *skb);
 211extern int                      neigh_connected_output(struct sk_buff *skb);
 212extern int                      neigh_compat_output(struct sk_buff *skb);
 213extern struct neighbour         *neigh_event_ns(struct neigh_table *tbl,
 214                                                u8 *lladdr, void *saddr,
 215                                                struct net_device *dev);
 216
 217extern struct neigh_parms       *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 218extern void                     neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
 219
 220static inline
 221struct net                      *neigh_parms_net(const struct neigh_parms *parms)
 222{
 223        return read_pnet(&parms->net);
 224}
 225
 226extern unsigned long            neigh_rand_reach_time(unsigned long base);
 227
 228extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 229                                               struct sk_buff *skb);
 230extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
 231extern struct pneigh_entry      *__pneigh_lookup(struct neigh_table *tbl,
 232                                                 struct net *net,
 233                                                 const void *key,
 234                                                 struct net_device *dev);
 235extern int                      pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
 236
 237static inline
 238struct net                      *pneigh_net(const struct pneigh_entry *pneigh)
 239{
 240        return read_pnet(&pneigh->net);
 241}
 242
 243extern void neigh_app_ns(struct neighbour *n);
 244extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
 245extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
 246extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
 247
 248struct neigh_seq_state {
 249        struct seq_net_private p;
 250        struct neigh_table *tbl;
 251        void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 252                                struct neighbour *n, loff_t *pos);
 253        unsigned int bucket;
 254        unsigned int flags;
 255#define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 256#define NEIGH_SEQ_IS_PNEIGH     0x00000002
 257#define NEIGH_SEQ_SKIP_NOARP    0x00000004
 258};
 259extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
 260extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 261extern void neigh_seq_stop(struct seq_file *, void *);
 262
 263extern int                      neigh_sysctl_register(struct net_device *dev, 
 264                                                      struct neigh_parms *p,
 265                                                      int p_id, int pdev_id,
 266                                                      char *p_name,
 267                                                      proc_handler *proc_handler,
 268                                                      ctl_handler *strategy);
 269extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
 270
 271static inline void __neigh_parms_put(struct neigh_parms *parms)
 272{
 273        atomic_dec(&parms->refcnt);
 274}
 275
 276static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 277{
 278        atomic_inc(&parms->refcnt);
 279        return parms;
 280}
 281
 282/*
 283 *      Neighbour references
 284 */
 285
 286static inline void neigh_release(struct neighbour *neigh)
 287{
 288        if (atomic_dec_and_test(&neigh->refcnt))
 289                neigh_destroy(neigh);
 290}
 291
 292static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 293{
 294        if (neigh)
 295                atomic_inc(&neigh->refcnt);
 296        return neigh;
 297}
 298
 299#define neigh_hold(n)   atomic_inc(&(n)->refcnt)
 300
 301static inline void neigh_confirm(struct neighbour *neigh)
 302{
 303        if (neigh)
 304                neigh->confirmed = jiffies;
 305}
 306
 307static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 308{
 309        neigh->used = jiffies;
 310        if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
 311                return __neigh_event_send(neigh, skb);
 312        return 0;
 313}
 314
 315static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
 316{
 317        unsigned seq;
 318        int hh_len;
 319
 320        do {
 321                int hh_alen;
 322
 323                seq = read_seqbegin(&hh->hh_lock);
 324                hh_len = hh->hh_len;
 325                hh_alen = HH_DATA_ALIGN(hh_len);
 326                memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 327        } while (read_seqretry(&hh->hh_lock, seq));
 328
 329        skb_push(skb, hh_len);
 330        return hh->hh_output(skb);
 331}
 332
 333static inline struct neighbour *
 334__neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 335{
 336        struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 337
 338        if (n || !creat)
 339                return n;
 340
 341        n = neigh_create(tbl, pkey, dev);
 342        return IS_ERR(n) ? NULL : n;
 343}
 344
 345static inline struct neighbour *
 346__neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 347  struct net_device *dev)
 348{
 349        struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 350
 351        if (n)
 352                return n;
 353
 354        return neigh_create(tbl, pkey, dev);
 355}
 356
 357struct neighbour_cb {
 358        unsigned long sched_next;
 359        unsigned int flags;
 360};
 361
 362#define LOCALLY_ENQUEUED 0x1
 363
 364#define NEIGH_CB(skb)   ((struct neighbour_cb *)(skb)->cb)
 365
 366#endif
 367
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