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 net_device *dev;
  69         struct neigh_parms *next;
  70         int     (*neigh_setup)(struct neighbour *);
  71         struct neigh_table *tbl;
  72         int     entries;
  73         void    *priv;
  74
  75         void    *sysctl_table;
  76
  77         int dead;
  78         atomic_t refcnt;
  79         struct rcu_head rcu_head;
  80
  81         int     base_reachable_time;
  82         int     retrans_time;
  83         int     gc_staletime;
  84         int     reachable_time;
  85         int     delay_probe_time;
  86
  87         int     queue_len;
  88         int     ucast_probes;
  89         int     app_probes;
  90         int     mcast_probes;
  91         int     anycast_delay;
  92         int     proxy_delay;
  93         int     proxy_qlen;
  94         int     locktime;
  95 };
  96
  97 struct neigh_statistics
  98 {
  99         unsigned long allocs;           /* number of allocated neighs */
 100         unsigned long destroys;         /* number of destroyed neighs */
 101         unsigned long hash_grows;       /* number of hash resizes */
 102
 103         unsigned long res_failed;       /* nomber of failed resolutions */
 104
 105         unsigned long lookups;          /* number of lookups */
 106         unsigned long hits;             /* number of hits (among lookups) */
 107
 108         unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
 109         unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
 110
 111         unsigned long periodic_gc_runs; /* number of periodic GC runs */
 112         unsigned long forced_gc_runs;   /* number of forced GC runs */
 113 };
 114
 115 #define NEIGH_CACHE_STAT_INC(tbl, field)                                \
 116         do {                                                            \
 117                 preempt_disable();                                      \
 118                 (per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
 119                 preempt_enable();                                       \
 120         } while (0)
 121
 122 struct neighbour
 123 {
 124         struct neighbour        *next;
 125         struct neigh_table      *tbl;
 126         struct neigh_parms      *parms;
 127         struct net_device               *dev;
 128         unsigned long           used;
 129         unsigned long           confirmed;
 130         unsigned long           updated;
 131         __u8                    flags;
 132         __u8                    nud_state;
 133         __u8                    type;
 134         __u8                    dead;
 135         atomic_t                probes;
 136         rwlock_t                lock;
 137         unsigned char           ha[(MAX_ADDR_LEN+sizeof(unsigned long)-1)&~(sizeof(unsigned long)-1)];
 138         struct hh_cache         *hh;
 139         atomic_t                refcnt;
 140         int                     (*output)(struct sk_buff *skb);
 141         struct sk_buff_head     arp_queue;
 142         struct timer_list       timer;
 143         struct neigh_ops        *ops;
 144         u8                      primary_key[0];
 145 };
 146
 147 struct neigh_ops
 148 {
 149         int                     family;
 150         void                    (*destructor)(struct neighbour *);
 151         void                    (*solicit)(struct neighbour *, struct sk_buff*);
 152         void                    (*error_report)(struct neighbour *, struct sk_buff*);
 153         int                     (*output)(struct sk_buff*);
 154         int                     (*connected_output)(struct sk_buff*);
 155         int                     (*hh_output)(struct sk_buff*);
 156         int                     (*queue_xmit)(struct sk_buff*);
 157 };
 158
 159 struct pneigh_entry
 160 {
 161         struct pneigh_entry     *next;
 162         struct net_device               *dev;
 163         u8                      key[0];
 164 };
 165
 166 /*
 167  *      neighbour table manipulation
 168  */
 169
 170
 171 struct neigh_table
 172 {
 173         struct neigh_table      *next;
 174         int                     family;
 175         int                     entry_size;
 176         int                     key_len;
 177         __u32                   (*hash)(const void *pkey, const struct net_device *);
 178         int                     (*constructor)(struct neighbour *);
 179         int                     (*pconstructor)(struct pneigh_entry *);
 180         void                    (*pdestructor)(struct pneigh_entry *);
 181         void                    (*proxy_redo)(struct sk_buff *skb);
 182         char                    *id;
 183         struct neigh_parms      parms;
 184         /* HACK. gc_* shoul follow parms without a gap! */
 185         int                     gc_interval;
 186         int                     gc_thresh1;
 187         int                     gc_thresh2;
 188         int                     gc_thresh3;
 189         unsigned long           last_flush;
 190         struct timer_list       gc_timer;
 191         struct timer_list       proxy_timer;
 192         struct sk_buff_head     proxy_queue;
 193         atomic_t                entries;
 194         rwlock_t                lock;
 195         unsigned long           last_rand;
 196         struct neigh_parms      *parms_list;
 197         kmem_cache_t            *kmem_cachep;
 198         struct neigh_statistics *stats;
 199         struct neighbour        **hash_buckets;
 200         unsigned int            hash_mask;
 201         __u32                   hash_rnd;
 202         unsigned int            hash_chain_gc;
 203         struct pneigh_entry     **phash_buckets;
 204 #ifdef CONFIG_PROC_FS
 205         struct proc_dir_entry   *pde;
 206 #endif
 207 };
 208
 209 /* flags for neigh_update() */
 210 #define NEIGH_UPDATE_F_OVERRIDE                 0x00000001
 211 #define NEIGH_UPDATE_F_WEAK_OVERRIDE            0x00000002
 212 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        0x00000004
 213 #define NEIGH_UPDATE_F_ISROUTER                 0x40000000
 214 #define NEIGH_UPDATE_F_ADMIN                    0x80000000
 215
 216 extern void                     neigh_table_init(struct neigh_table *tbl);
 217 extern int                      neigh_table_clear(struct neigh_table *tbl);
 218 extern struct neighbour *       neigh_lookup(struct neigh_table *tbl,
 219                                              const void *pkey,
 220                                              struct net_device *dev);
 221 extern struct neighbour *       neigh_lookup_nodev(struct neigh_table *tbl,
 222                                                    const void *pkey);
 223 extern struct neighbour *       neigh_create(struct neigh_table *tbl,
 224                                              const void *pkey,
 225                                              struct net_device *dev);
 226 extern void                     neigh_destroy(struct neighbour *neigh);
 227 extern int                      __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
 228 extern int                      neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 229                                              u32 flags);
 230 extern void                     neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 231 extern int                      neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 232 extern int                      neigh_resolve_output(struct sk_buff *skb);
 233 extern int                      neigh_connected_output(struct sk_buff *skb);
 234 extern int                      neigh_compat_output(struct sk_buff *skb);
 235 extern struct neighbour         *neigh_event_ns(struct neigh_table *tbl,
 236                                                 u8 *lladdr, void *saddr,
 237                                                 struct net_device *dev);
 238
 239 extern struct neigh_parms       *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 240 extern void                     neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
 241 extern void                     neigh_parms_destroy(struct neigh_parms *parms);
 242 extern unsigned long            neigh_rand_reach_time(unsigned long base);
 243
 244 extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 245                                                struct sk_buff *skb);
 246 extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, const void *key, struct net_device *dev, int creat);
 247 extern int                      pneigh_delete(struct neigh_table *tbl, const void *key, struct net_device *dev);
 248
 249 struct netlink_callback;
 250 struct nlmsghdr;
 251 extern int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
 252 extern int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 253 extern int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 254 extern void neigh_app_ns(struct neighbour *n);
 255
 256 extern int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
 257 extern int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 258
 259 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
 260 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
 261 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
 262
 263 struct neigh_seq_state {
 264         struct neigh_table *tbl;
 265         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 266                                 struct neighbour *n, loff_t *pos);
 267         unsigned int bucket;
 268         unsigned int flags;
 269 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 270 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
 271 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
 272 };
 273 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
 274 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 275 extern void neigh_seq_stop(struct seq_file *, void *);
 276
 277 extern int                      neigh_sysctl_register(struct net_device *dev,
 278                                                       struct neigh_parms *p,
 279                                                       int p_id, int pdev_id,
 280                                                       char *p_name,
 281                                                       proc_handler *proc_handler,
 282                                                       ctl_handler *strategy);
 283 extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
 284
 285 static inline void __neigh_parms_put(struct neigh_parms *parms)
 286 {
 287         atomic_dec(&parms->refcnt);
 288 }
 289
 290 static inline void neigh_parms_put(struct neigh_parms *parms)
 291 {
 292         if (atomic_dec_and_test(&parms->refcnt))
 293                 neigh_parms_destroy(parms);
 294 }
 295
 296 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 297 {
 298         atomic_inc(&parms->refcnt);
 299         return parms;
 300 }
 301
 302 /*
 303  *      Neighbour references
 304  */
 305
 306 static inline void neigh_release(struct neighbour *neigh)
 307 {
 308         if (atomic_dec_and_test(&neigh->refcnt))
 309                 neigh_destroy(neigh);
 310 }
 311
 312 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 313 {
 314         if (neigh)
 315                 atomic_inc(&neigh->refcnt);
 316         return neigh;
 317 }
 318
 319 #define neigh_hold(n)   atomic_inc(&(n)->refcnt)
 320
 321 static inline void neigh_confirm(struct neighbour *neigh)
 322 {
 323         if (neigh)
 324                 neigh->confirmed = jiffies;
 325 }
 326
 327 static inline int neigh_is_connected(struct neighbour *neigh)
 328 {
 329         return neigh->nud_state&NUD_CONNECTED;
 330 }
 331
 332 static inline int neigh_is_valid(struct neighbour *neigh)
 333 {
 334         return neigh->nud_state&NUD_VALID;
 335 }
 336
 337 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 338 {
 339         neigh->used = jiffies;
 340         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
 341                 return __neigh_event_send(neigh, skb);
 342         return 0;
 343 }
 344
 345 static inline struct neighbour *
 346 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 347 {
 348         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 349
 350         if (n || !creat)
 351                 return n;
 352
 353         n = neigh_create(tbl, pkey, dev);
 354         return IS_ERR(n) ? NULL : n;
 355 }
 356
 357 static inline struct neighbour *
 358 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 359   struct net_device *dev)
 360 {
 361         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 362
 363         if (n)
 364                 return n;
 365
 366         return neigh_create(tbl, pkey, dev);
 367 }
 368
 369 #define LOCALLY_ENQUEUED -2
 370
 371 #endif
 372 #endif
 373
 374