include/net/neighbour.h

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