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   1 #ifndef _NET_NEIGHBOUR_H
   2 #define _NET_NEIGHBOUR_H
   3
   4 /*
   5  *      Generic neighbour manipulation
   6  *
   7  *      Authors:
   8  *      Pedro Roque             <roque@di.fc.ul.pt>
   9  *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
  10  *
  11  *      Changes:
  12  *
  13  *      Harald Welte:           <laforge@gnumonks.org>
  14  *              - Add neighbour cache statistics like rtstat
  15  */
  16
  17 /* The following flags & states are exported to user space,
  18    so that they should be moved to include/linux/ directory.
  19  */
  20
  21 /*
  22  *      Neighbor Cache Entry Flags
  23  */
  24
  25 #define NTF_PROXY       0x08    /* == ATF_PUBL */
  26 #define NTF_ROUTER      0x80
  27
  28 /*
  29  *      Neighbor Cache Entry States.
  30  */
  31
  32 #define NUD_INCOMPLETE  0x01
  33 #define NUD_REACHABLE   0x02
  34 #define NUD_STALE       0x04
  35 #define NUD_DELAY       0x08
  36 #define NUD_PROBE       0x10
  37 #define NUD_FAILED      0x20
  38
  39 /* Dummy states */
  40 #define NUD_NOARP       0x40
  41 #define NUD_PERMANENT   0x80
  42 #define NUD_NONE        0x00
  43
  44 /* NUD_NOARP & NUD_PERMANENT are pseudostates, they never change
  45    and make no address resolution or NUD.
  46    NUD_PERMANENT is also cannot be deleted by garbage collectors.
  47  */
  48
  49 #ifdef __KERNEL__
  50
  51 #include <asm/atomic.h>
  52 #include <linux/netdevice.h>
  53 #include <linux/skbuff.h>
  54 #include <linux/rcupdate.h>
  55 #include <linux/seq_file.h>
  56
  57 #include <linux/err.h>
  58 #include <linux/sysctl.h>
  59
  60 #define NUD_IN_TIMER    (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
  61 #define NUD_VALID       (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
  62 #define NUD_CONNECTED   (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
  63
  64 struct neighbour;
  65
  66 struct neigh_parms
  67 {
  68         struct net_device *dev;
  69         struct neigh_parms *next;
  70         int     (*neigh_setup)(struct neighbour *);
  71         void    (*neigh_destructor)(struct neighbour *);
  72         struct neigh_table *tbl;
  73
  74         void    *sysctl_table;
  75
  76         int dead;
  77         atomic_t refcnt;
  78         struct rcu_head rcu_head;
  79
  80         int     base_reachable_time;
  81         int     retrans_time;
  82         int     gc_staletime;
  83         int     reachable_time;
  84         int     delay_probe_time;
  85
  86         int     queue_len;
  87         int     ucast_probes;
  88         int     app_probes;
  89         int     mcast_probes;
  90         int     anycast_delay;
  91         int     proxy_delay;
  92         int     proxy_qlen;
  93         int     locktime;
  94 };
  95
  96 struct neigh_statistics
  97 {
  98         unsigned long allocs;           /* number of allocated neighs */
  99         unsigned long destroys;         /* number of destroyed neighs */
 100         unsigned long hash_grows;       /* number of hash resizes */
 101
 102         unsigned long res_failed;       /* nomber of failed resolutions */
 103
 104         unsigned long lookups;          /* number of lookups */
 105         unsigned long hits;             /* number of hits (among lookups) */
 106
 107         unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
 108         unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
 109
 110         unsigned long periodic_gc_runs; /* number of periodic GC runs */
 111         unsigned long forced_gc_runs;   /* number of forced GC runs */
 112 };
 113
 114 #define NEIGH_CACHE_STAT_INC(tbl, field)                                \
 115         do {                                                            \
 116                 preempt_disable();                                      \
 117                 (per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
 118                 preempt_enable();                                       \
 119         } while (0)
 120
 121 struct neighbour
 122 {
 123         struct neighbour        *next;
 124         struct neigh_table      *tbl;
 125         struct neigh_parms      *parms;
 126         struct net_device               *dev;
 127         unsigned long           used;
 128         unsigned long           confirmed;
 129         unsigned long           updated;
 130         __u8                    flags;
 131         __u8                    nud_state;
 132         __u8                    type;
 133         __u8                    dead;
 134         atomic_t                probes;
 135         rwlock_t                lock;
 136         unsigned char           ha[(MAX_ADDR_LEN+sizeof(unsigned long)-1)&~(sizeof(unsigned long)-1)];
 137         struct hh_cache         *hh;
 138         atomic_t                refcnt;
 139         int                     (*output)(struct sk_buff *skb);
 140         struct sk_buff_head     arp_queue;
 141         struct timer_list       timer;
 142         struct neigh_ops        *ops;
 143         u8                      primary_key[0];
 144 };
 145
 146 struct neigh_ops
 147 {
 148         int                     family;
 149         void                    (*solicit)(struct neighbour *, struct sk_buff*);
 150         void                    (*error_report)(struct neighbour *, struct sk_buff*);
 151         int                     (*output)(struct sk_buff*);
 152         int                     (*connected_output)(struct sk_buff*);
 153         int                     (*hh_output)(struct sk_buff*);
 154         int                     (*queue_xmit)(struct sk_buff*);
 155 };
 156
 157 struct pneigh_entry
 158 {
 159         struct pneigh_entry     *next;
 160         struct net_device               *dev;
 161         u8                      key[0];
 162 };
 163
 164 /*
 165  *      neighbour table manipulation
 166  */
 167
 168
 169 struct neigh_table
 170 {
 171         struct neigh_table      *next;
 172         int                     family;
 173         int                     entry_size;
 174         int                     key_len;
 175         __u32                   (*hash)(const void *pkey, const struct net_device *);
 176         int                     (*constructor)(struct neighbour *);
 177         int                     (*pconstructor)(struct pneigh_entry *);
 178         void                    (*pdestructor)(struct pneigh_entry *);
 179         void                    (*proxy_redo)(struct sk_buff *skb);
 180         char                    *id;
 181         struct neigh_parms      parms;
 182         /* HACK. gc_* shoul follow parms without a gap! */
 183         int                     gc_interval;
 184         int                     gc_thresh1;
 185         int                     gc_thresh2;
 186         int                     gc_thresh3;
 187         unsigned long           last_flush;
 188         struct timer_list       gc_timer;
 189         struct timer_list       proxy_timer;
 190         struct sk_buff_head     proxy_queue;
 191         atomic_t                entries;
 192         rwlock_t                lock;
 193         unsigned long           last_rand;
 194         kmem_cache_t            *kmem_cachep;
 195         struct neigh_statistics *stats;
 196         struct neighbour        **hash_buckets;
 197         unsigned int            hash_mask;
 198         __u32                   hash_rnd;
 199         unsigned int            hash_chain_gc;
 200         struct pneigh_entry     **phash_buckets;
 201 #ifdef CONFIG_PROC_FS
 202         struct proc_dir_entry   *pde;
 203 #endif
 204 };
 205
 206 /* flags for neigh_update() */
 207 #define NEIGH_UPDATE_F_OVERRIDE                 0x00000001
 208 #define NEIGH_UPDATE_F_WEAK_OVERRIDE            0x00000002
 209 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        0x00000004
 210 #define NEIGH_UPDATE_F_ISROUTER                 0x40000000
 211 #define NEIGH_UPDATE_F_ADMIN                    0x80000000
 212
 213 extern void                     neigh_table_init(struct neigh_table *tbl);
 214 extern void                     neigh_table_init_no_netlink(struct neigh_table *tbl);
 215 extern int                      neigh_table_clear(struct neigh_table *tbl);
 216 extern struct neighbour *       neigh_lookup(struct neigh_table *tbl,
 217                                              const void *pkey,
 218                                              struct net_device *dev);
 219 extern struct neighbour *       neigh_lookup_nodev(struct neigh_table *tbl,
 220                                                    const void *pkey);
 221 extern struct neighbour *       neigh_create(struct neigh_table *tbl,
 222                                              const void *pkey,
 223                                              struct net_device *dev);
 224 extern void                     neigh_destroy(struct neighbour *neigh);
 225 extern int                      __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
 226 extern int                      neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 227                                              u32 flags);
 228 extern void                     neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 229 extern int                      neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 230 extern int                      neigh_resolve_output(struct sk_buff *skb);
 231 extern int                      neigh_connected_output(struct sk_buff *skb);
 232 extern int                      neigh_compat_output(struct sk_buff *skb);
 233 extern struct neighbour         *neigh_event_ns(struct neigh_table *tbl,
 234                                                 u8 *lladdr, void *saddr,
 235                                                 struct net_device *dev);
 236
 237 extern struct neigh_parms       *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 238 extern void                     neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
 239 extern void                     neigh_parms_destroy(struct neigh_parms *parms);
 240 extern unsigned long            neigh_rand_reach_time(unsigned long base);
 241
 242 extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 243                                                struct sk_buff *skb);
 244 extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, const void *key, struct net_device *dev, int creat);
 245 extern int                      pneigh_delete(struct neigh_table *tbl, const void *key, struct net_device *dev);
 246
 247 struct netlink_callback;
 248 struct nlmsghdr;
 249 extern int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
 250 extern int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 251 extern int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 252 extern void neigh_app_ns(struct neighbour *n);
 253
 254 extern int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
 255 extern int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 256
 257 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
 258 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
 259 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
 260
 261 struct neigh_seq_state {
 262         struct neigh_table *tbl;
 263         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 264                                 struct neighbour *n, loff_t *pos);
 265         unsigned int bucket;
 266         unsigned int flags;
 267 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 268 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
 269 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
 270 };
 271 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
 272 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 273 extern void neigh_seq_stop(struct seq_file *, void *);
 274
 275 extern int                      neigh_sysctl_register(struct net_device *dev,
 276                                                       struct neigh_parms *p,
 277                                                       int p_id, int pdev_id,
 278                                                       char *p_name,
 279                                                       proc_handler *proc_handler,
 280                                                       ctl_handler *strategy);
 281 extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
 282
 283 static inline void __neigh_parms_put(struct neigh_parms *parms)
 284 {
 285         atomic_dec(&parms->refcnt);
 286 }
 287
 288 static inline void neigh_parms_put(struct neigh_parms *parms)
 289 {
 290         if (atomic_dec_and_test(&parms->refcnt))
 291                 neigh_parms_destroy(parms);
 292 }
 293
 294 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 295 {
 296         atomic_inc(&parms->refcnt);
 297         return parms;
 298 }
 299
 300 /*
 301  *      Neighbour references
 302  */
 303
 304 static inline void neigh_release(struct neighbour *neigh)
 305 {
 306         if (atomic_dec_and_test(&neigh->refcnt))
 307                 neigh_destroy(neigh);
 308 }
 309
 310 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 311 {
 312         if (neigh)
 313                 atomic_inc(&neigh->refcnt);
 314         return neigh;
 315 }
 316
 317 #define neigh_hold(n)   atomic_inc(&(n)->refcnt)
 318
 319 static inline void neigh_confirm(struct neighbour *neigh)
 320 {
 321         if (neigh)
 322                 neigh->confirmed = jiffies;
 323 }
 324
 325 static inline int neigh_is_connected(struct neighbour *neigh)
 326 {
 327         return neigh->nud_state&NUD_CONNECTED;
 328 }
 329
 330 static inline int neigh_is_valid(struct neighbour *neigh)
 331 {
 332         return neigh->nud_state&NUD_VALID;
 333 }
 334
 335 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 336 {
 337         neigh->used = jiffies;
 338         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
 339                 return __neigh_event_send(neigh, skb);
 340         return 0;
 341 }
 342
 343 static inline struct neighbour *
 344 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 345 {
 346         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 347
 348         if (n || !creat)
 349                 return n;
 350
 351         n = neigh_create(tbl, pkey, dev);
 352         return IS_ERR(n) ? NULL : n;
 353 }
 354
 355 static inline struct neighbour *
 356 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 357   struct net_device *dev)
 358 {
 359         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 360
 361         if (n)
 362                 return n;
 363
 364         return neigh_create(tbl, pkey, dev);
 365 }
 366
 367 struct neighbour_cb {
 368         unsigned long sched_next;
 369         unsigned int flags;
 370 };
 371
 372 #define LOCALLY_ENQUEUED 0x1
 373
 374 #define NEIGH_CB(skb)   ((struct neighbour_cb *)(skb)->cb)
 375
 376 #endif
 377 #endif
 378
 379