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