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) this_cpu_inc((tbl)->stats->field)
  92
  93 struct neighbour {
  94         struct neighbour        *next;
  95         struct neigh_table      *tbl;
  96         struct neigh_parms      *parms;
  97         struct net_device               *dev;
  98         unsigned long           used;
  99         unsigned long           confirmed;
 100         unsigned long           updated;
 101         __u8                    flags;
 102         __u8                    nud_state;
 103         __u8                    type;
 104         __u8                    dead;
 105         atomic_t                probes;
 106         rwlock_t                lock;
 107         unsigned char           ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
 108         struct hh_cache         *hh;
 109         atomic_t                refcnt;
 110         int                     (*output)(struct sk_buff *skb);
 111         struct sk_buff_head     arp_queue;
 112         struct timer_list       timer;
 113         const struct neigh_ops  *ops;
 114         u8                      primary_key[0];
 115 };
 116
 117 struct neigh_ops {
 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         struct pneigh_entry     *next;
 129 #ifdef CONFIG_NET_NS
 130         struct net              *net;
 131 #endif
 132         struct net_device       *dev;
 133         u8                      flags;
 134         u8                      key[0];
 135 };
 136
 137 /*
 138  *      neighbour table manipulation
 139  */
 140
 141
 142 struct neigh_table {
 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 delayed_work     gc_work;
 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         struct pneigh_entry     **phash_buckets;
 172 };
 173
 174 /* flags for neigh_update() */
 175 #define NEIGH_UPDATE_F_OVERRIDE                 0x00000001
 176 #define NEIGH_UPDATE_F_WEAK_OVERRIDE            0x00000002
 177 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        0x00000004
 178 #define NEIGH_UPDATE_F_ISROUTER                 0x40000000
 179 #define NEIGH_UPDATE_F_ADMIN                    0x80000000
 180
 181 extern void                     neigh_table_init(struct neigh_table *tbl);
 182 extern void                     neigh_table_init_no_netlink(struct neigh_table *tbl);
 183 extern int                      neigh_table_clear(struct neigh_table *tbl);
 184 extern struct neighbour *       neigh_lookup(struct neigh_table *tbl,
 185                                              const void *pkey,
 186                                              struct net_device *dev);
 187 extern struct neighbour *       neigh_lookup_nodev(struct neigh_table *tbl,
 188                                                    struct net *net,
 189                                                    const void *pkey);
 190 extern struct neighbour *       neigh_create(struct neigh_table *tbl,
 191                                              const void *pkey,
 192                                              struct net_device *dev);
 193 extern void                     neigh_destroy(struct neighbour *neigh);
 194 extern int                      __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
 195 extern int                      neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 196                                              u32 flags);
 197 extern void                     neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 198 extern int                      neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 199 extern int                      neigh_resolve_output(struct sk_buff *skb);
 200 extern int                      neigh_connected_output(struct sk_buff *skb);
 201 extern int                      neigh_compat_output(struct sk_buff *skb);
 202 extern struct neighbour         *neigh_event_ns(struct neigh_table *tbl,
 203                                                 u8 *lladdr, void *saddr,
 204                                                 struct net_device *dev);
 205
 206 extern struct neigh_parms       *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 207 extern void                     neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
 208
 209 static inline
 210 struct net                      *neigh_parms_net(const struct neigh_parms *parms)
 211 {
 212         return read_pnet(&parms->net);
 213 }
 214
 215 extern unsigned long            neigh_rand_reach_time(unsigned long base);
 216
 217 extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 218                                                struct sk_buff *skb);
 219 extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
 220 extern struct pneigh_entry      *__pneigh_lookup(struct neigh_table *tbl,
 221                                                  struct net *net,
 222                                                  const void *key,
 223                                                  struct net_device *dev);
 224 extern int                      pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
 225
 226 static inline
 227 struct net                      *pneigh_net(const struct pneigh_entry *pneigh)
 228 {
 229         return read_pnet(&pneigh->net);
 230 }
 231
 232 extern void neigh_app_ns(struct neighbour *n);
 233 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
 234 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
 235 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
 236
 237 struct neigh_seq_state {
 238         struct seq_net_private p;
 239         struct neigh_table *tbl;
 240         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 241                                 struct neighbour *n, loff_t *pos);
 242         unsigned int bucket;
 243         unsigned int flags;
 244 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 245 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
 246 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
 247 };
 248 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
 249 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 250 extern void neigh_seq_stop(struct seq_file *, void *);
 251
 252 extern int                      neigh_sysctl_register(struct net_device *dev,
 253                                                       struct neigh_parms *p,
 254                                                       int p_id, int pdev_id,
 255                                                       char *p_name,
 256                                                       proc_handler *proc_handler);
 257 extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
 258
 259 static inline void __neigh_parms_put(struct neigh_parms *parms)
 260 {
 261         atomic_dec(&parms->refcnt);
 262 }
 263
 264 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 265 {
 266         atomic_inc(&parms->refcnt);
 267         return parms;
 268 }
 269
 270 /*
 271  *      Neighbour references
 272  */
 273
 274 static inline void neigh_release(struct neighbour *neigh)
 275 {
 276         if (atomic_dec_and_test(&neigh->refcnt))
 277                 neigh_destroy(neigh);
 278 }
 279
 280 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 281 {
 282         if (neigh)
 283                 atomic_inc(&neigh->refcnt);
 284         return neigh;
 285 }
 286
 287 #define neigh_hold(n)   atomic_inc(&(n)->refcnt)
 288
 289 static inline void neigh_confirm(struct neighbour *neigh)
 290 {
 291         if (neigh)
 292                 neigh->confirmed = jiffies;
 293 }
 294
 295 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 296 {
 297         neigh->used = jiffies;
 298         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
 299                 return __neigh_event_send(neigh, skb);
 300         return 0;
 301 }
 302
 303 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
 304 {
 305         unsigned seq;
 306         int hh_len;
 307
 308         do {
 309                 int hh_alen;
 310
 311                 seq = read_seqbegin(&hh->hh_lock);
 312                 hh_len = hh->hh_len;
 313                 hh_alen = HH_DATA_ALIGN(hh_len);
 314                 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 315         } while (read_seqretry(&hh->hh_lock, seq));
 316
 317         skb_push(skb, hh_len);
 318         return hh->hh_output(skb);
 319 }
 320
 321 static inline struct neighbour *
 322 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 323 {
 324         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 325
 326         if (n || !creat)
 327                 return n;
 328
 329         n = neigh_create(tbl, pkey, dev);
 330         return IS_ERR(n) ? NULL : n;
 331 }
 332
 333 static inline struct neighbour *
 334 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 335   struct net_device *dev)
 336 {
 337         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 338
 339         if (n)
 340                 return n;
 341
 342         return neigh_create(tbl, pkey, dev);
 343 }
 344
 345 struct neighbour_cb {
 346         unsigned long sched_next;
 347         unsigned int flags;
 348 };
 349
 350 #define LOCALLY_ENQUEUED 0x1
 351
 352 #define NEIGH_CB(skb)   ((struct neighbour_cb *)(skb)->cb)
 353
 354 #endif