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