include/net/neighbour.h

   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/skbuff.h>
  53 #include <linux/netdevice.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 neigh_parms *next;
  69         int     (*neigh_setup)(struct neighbour *);
  70         struct neigh_table *tbl;
  71         int     entries;
  72         void    *priv;
  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                 (per_cpu_ptr((tbl)->stats, smp_processor_id())->field++)
 116
 117 struct neighbour
 118 {
 119         struct neighbour        *next;
 120         struct neigh_table      *tbl;
 121         struct neigh_parms      *parms;
 122         struct net_device               *dev;
 123         unsigned long           used;
 124         unsigned long           confirmed;
 125         unsigned long           updated;
 126         __u8                    flags;
 127         __u8                    nud_state;
 128         __u8                    type;
 129         __u8                    dead;
 130         atomic_t                probes;
 131         rwlock_t                lock;
 132         unsigned char           ha[(MAX_ADDR_LEN+sizeof(unsigned long)-1)&~(sizeof(unsigned long)-1)];
 133         struct hh_cache         *hh;
 134         atomic_t                refcnt;
 135         int                     (*output)(struct sk_buff *skb);
 136         struct sk_buff_head     arp_queue;
 137         struct timer_list       timer;
 138         struct neigh_ops        *ops;
 139         u8                      primary_key[0];
 140 };
 141
 142 struct neigh_ops
 143 {
 144         int                     family;
 145         void                    (*destructor)(struct neighbour *);
 146         void                    (*solicit)(struct neighbour *, struct sk_buff*);
 147         void                    (*error_report)(struct neighbour *, struct sk_buff*);
 148         int                     (*output)(struct sk_buff*);
 149         int                     (*connected_output)(struct sk_buff*);
 150         int                     (*hh_output)(struct sk_buff*);
 151         int                     (*queue_xmit)(struct sk_buff*);
 152 };
 153
 154 struct pneigh_entry
 155 {
 156         struct pneigh_entry     *next;
 157         struct net_device               *dev;
 158         u8                      key[0];
 159 };
 160
 161 /*
 162  *      neighbour table manipulation
 163  */
 164
 165
 166 struct neigh_table
 167 {
 168         struct neigh_table      *next;
 169         int                     family;
 170         int                     entry_size;
 171         int                     key_len;
 172         __u32                   (*hash)(const void *pkey, const struct net_device *);
 173         int                     (*constructor)(struct neighbour *);
 174         int                     (*pconstructor)(struct pneigh_entry *);
 175         void                    (*pdestructor)(struct pneigh_entry *);
 176         void                    (*proxy_redo)(struct sk_buff *skb);
 177         char                    *id;
 178         struct neigh_parms      parms;
 179         /* HACK. gc_* shoul follow parms without a gap! */
 180         int                     gc_interval;
 181         int                     gc_thresh1;
 182         int                     gc_thresh2;
 183         int                     gc_thresh3;
 184         unsigned long           last_flush;
 185         struct timer_list       gc_timer;
 186         struct timer_list       proxy_timer;
 187         struct sk_buff_head     proxy_queue;
 188         int                     entries;
 189         rwlock_t                lock;
 190         unsigned long           last_rand;
 191         struct neigh_parms      *parms_list;
 192         kmem_cache_t            *kmem_cachep;
 193         struct neigh_statistics *stats;
 194         struct neighbour        **hash_buckets;
 195         unsigned int            hash_mask;
 196         __u32                   hash_rnd;
 197         unsigned int            hash_chain_gc;
 198         struct pneigh_entry     **phash_buckets;
 199 #ifdef CONFIG_PROC_FS
 200         struct proc_dir_entry   *pde;
 201 #endif
 202 };
 203
 204 /* flags for neigh_update() */
 205 #define NEIGH_UPDATE_F_OVERRIDE                 0x00000001
 206 #define NEIGH_UPDATE_F_WEAK_OVERRIDE            0x00000002
 207 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        0x00000004
 208 #define NEIGH_UPDATE_F_ISROUTER                 0x40000000
 209 #define NEIGH_UPDATE_F_ADMIN                    0x80000000
 210
 211 extern void                     neigh_table_init(struct neigh_table *tbl);
 212 extern int                      neigh_table_clear(struct neigh_table *tbl);
 213 extern struct neighbour *       neigh_lookup(struct neigh_table *tbl,
 214                                              const void *pkey,
 215                                              struct net_device *dev);
 216 extern struct neighbour *       neigh_lookup_nodev(struct neigh_table *tbl,
 217                                                    const void *pkey);
 218 extern struct neighbour *       neigh_create(struct neigh_table *tbl,
 219                                              const void *pkey,
 220                                              struct net_device *dev);
 221 extern void                     neigh_destroy(struct neighbour *neigh);
 222 extern int                      __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
 223 extern int                      neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 224                                              u32 flags);
 225 extern void                     neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 226 extern int                      neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 227 extern int                      neigh_resolve_output(struct sk_buff *skb);
 228 extern int                      neigh_connected_output(struct sk_buff *skb);
 229 extern int                      neigh_compat_output(struct sk_buff *skb);
 230 extern struct neighbour         *neigh_event_ns(struct neigh_table *tbl,
 231                                                 u8 *lladdr, void *saddr,
 232                                                 struct net_device *dev);
 233
 234 extern struct neigh_parms       *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 235 extern void                     neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
 236 extern void                     neigh_parms_destroy(struct neigh_parms *parms);
 237 extern unsigned long            neigh_rand_reach_time(unsigned long base);
 238
 239 extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 240                                                struct sk_buff *skb);
 241 extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, const void *key, struct net_device *dev, int creat);
 242 extern int                      pneigh_delete(struct neigh_table *tbl, const void *key, struct net_device *dev);
 243
 244 struct netlink_callback;
 245 struct nlmsghdr;
 246 extern int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
 247 extern int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 248 extern int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 249 extern void neigh_app_ns(struct neighbour *n);
 250
 251 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
 252 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
 253 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
 254
 255 struct neigh_seq_state {
 256         struct neigh_table *tbl;
 257         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 258                                 struct neighbour *n, loff_t *pos);
 259         unsigned int bucket;
 260         unsigned int flags;
 261 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 262 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
 263 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
 264 };
 265 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
 266 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 267 extern void neigh_seq_stop(struct seq_file *, void *);
 268
 269 extern int                      neigh_sysctl_register(struct net_device *dev,
 270                                                       struct neigh_parms *p,
 271                                                       int p_id, int pdev_id,
 272                                                       char *p_name,
 273                                                       proc_handler *proc_handler);
 274 extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
 275
 276 static inline void __neigh_parms_put(struct neigh_parms *parms)
 277 {
 278         atomic_dec(&parms->refcnt);
 279 }
 280
 281 static inline void neigh_parms_put(struct neigh_parms *parms)
 282 {
 283         if (atomic_dec_and_test(&parms->refcnt))
 284                 neigh_parms_destroy(parms);
 285 }
 286
 287 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 288 {
 289         atomic_inc(&parms->refcnt);
 290         return parms;
 291 }
 292
 293 /*
 294  *      Neighbour references
 295  */
 296
 297 static inline void neigh_release(struct neighbour *neigh)
 298 {
 299         if (atomic_dec_and_test(&neigh->refcnt))
 300                 neigh_destroy(neigh);
 301 }
 302
 303 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 304 {
 305         if (neigh)
 306                 atomic_inc(&neigh->refcnt);
 307         return neigh;
 308 }
 309
 310 #define neigh_hold(n)   atomic_inc(&(n)->refcnt)
 311
 312 static inline void neigh_confirm(struct neighbour *neigh)
 313 {
 314         if (neigh)
 315                 neigh->confirmed = jiffies;
 316 }
 317
 318 static inline int neigh_is_connected(struct neighbour *neigh)
 319 {
 320         return neigh->nud_state&NUD_CONNECTED;
 321 }
 322
 323 static inline int neigh_is_valid(struct neighbour *neigh)
 324 {
 325         return neigh->nud_state&NUD_VALID;
 326 }
 327
 328 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 329 {
 330         neigh->used = jiffies;
 331         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
 332                 return __neigh_event_send(neigh, skb);
 333         return 0;
 334 }
 335
 336 static inline struct neighbour *
 337 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 338 {
 339         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 340
 341         if (n || !creat)
 342                 return n;
 343
 344         n = neigh_create(tbl, pkey, dev);
 345         return IS_ERR(n) ? NULL : n;
 346 }
 347
 348 static inline struct neighbour *
 349 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 350   struct net_device *dev)
 351 {
 352         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 353
 354         if (n)
 355                 return n;
 356
 357         return neigh_create(tbl, pkey, dev);
 358 }
 359
 360 #define LOCALLY_ENQUEUED -2
 361
 362 #endif
 363 #endif
 364
 365