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 /*
  30  * NUD stands for "neighbor unreachability detection"
  31  */
  32
  33 #define NUD_IN_TIMER    (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
  34 #define NUD_VALID       (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
  35 #define NUD_CONNECTED   (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
  36
  37 struct neighbour;
  38
  39 struct neigh_parms
  40 {
  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 {
  74         unsigned long allocs;           /* number of allocated neighs */
  75         unsigned long destroys;         /* number of destroyed neighs */
  76         unsigned long hash_grows;       /* number of hash resizes */
  77
  78         unsigned long res_failed;       /* nomber of failed resolutions */
  79
  80         unsigned long lookups;          /* number of lookups */
  81         unsigned long hits;             /* number of hits (among lookups) */
  82
  83         unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
  84         unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
  85
  86         unsigned long periodic_gc_runs; /* number of periodic GC runs */
  87         unsigned long forced_gc_runs;   /* number of forced GC runs */
  88 };
  89
  90 #define NEIGH_CACHE_STAT_INC(tbl, field)                                \
  91         do {                                                            \
  92                 preempt_disable();                                      \
  93                 (per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
  94                 preempt_enable();                                       \
  95         } while (0)
  96
  97 struct neighbour
  98 {
  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         struct neigh_ops        *ops;
 119         u8                      primary_key[0];
 120 };
 121
 122 struct neigh_ops
 123 {
 124         int                     family;
 125         void                    (*solicit)(struct neighbour *, struct sk_buff*);
 126         void                    (*error_report)(struct neighbour *, struct sk_buff*);
 127         int                     (*output)(struct sk_buff*);
 128         int                     (*connected_output)(struct sk_buff*);
 129         int                     (*hh_output)(struct sk_buff*);
 130         int                     (*queue_xmit)(struct sk_buff*);
 131 };
 132
 133 struct pneigh_entry
 134 {
 135         struct pneigh_entry     *next;
 136 #ifdef CONFIG_NET_NS
 137         struct net              *net;
 138 #endif
 139         struct net_device       *dev;
 140         u8                      flags;
 141         u8                      key[0];
 142 };
 143
 144 /*
 145  *      neighbour table manipulation
 146  */
 147
 148
 149 struct neigh_table
 150 {
 151         struct neigh_table      *next;
 152         int                     family;
 153         int                     entry_size;
 154         int                     key_len;
 155         __u32                   (*hash)(const void *pkey, const struct net_device *);
 156         int                     (*constructor)(struct neighbour *);
 157         int                     (*pconstructor)(struct pneigh_entry *);
 158         void                    (*pdestructor)(struct pneigh_entry *);
 159         void                    (*proxy_redo)(struct sk_buff *skb);
 160         char                    *id;
 161         struct neigh_parms      parms;
 162         /* HACK. gc_* shoul follow parms without a gap! */
 163         int                     gc_interval;
 164         int                     gc_thresh1;
 165         int                     gc_thresh2;
 166         int                     gc_thresh3;
 167         unsigned long           last_flush;
 168         struct timer_list       gc_timer;
 169         struct timer_list       proxy_timer;
 170         struct sk_buff_head     proxy_queue;
 171         atomic_t                entries;
 172         rwlock_t                lock;
 173         unsigned long           last_rand;
 174         struct kmem_cache               *kmem_cachep;
 175         struct neigh_statistics *stats;
 176         struct neighbour        **hash_buckets;
 177         unsigned int            hash_mask;
 178         __u32                   hash_rnd;
 179         unsigned int            hash_chain_gc;
 180         struct pneigh_entry     **phash_buckets;
 181 #ifdef CONFIG_PROC_FS
 182         struct proc_dir_entry   *pde;
 183 #endif
 184 };
 185
 186 /* flags for neigh_update() */
 187 #define NEIGH_UPDATE_F_OVERRIDE                 0x00000001
 188 #define NEIGH_UPDATE_F_WEAK_OVERRIDE            0x00000002
 189 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        0x00000004
 190 #define NEIGH_UPDATE_F_ISROUTER                 0x40000000
 191 #define NEIGH_UPDATE_F_ADMIN                    0x80000000
 192
 193 extern void                     neigh_table_init(struct neigh_table *tbl);
 194 extern void                     neigh_table_init_no_netlink(struct neigh_table *tbl);
 195 extern int                      neigh_table_clear(struct neigh_table *tbl);
 196 extern struct neighbour *       neigh_lookup(struct neigh_table *tbl,
 197                                              const void *pkey,
 198                                              struct net_device *dev);
 199 extern struct neighbour *       neigh_lookup_nodev(struct neigh_table *tbl,
 200                                                    struct net *net,
 201                                                    const void *pkey);
 202 extern struct neighbour *       neigh_create(struct neigh_table *tbl,
 203                                              const void *pkey,
 204                                              struct net_device *dev);
 205 extern void                     neigh_destroy(struct neighbour *neigh);
 206 extern int                      __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
 207 extern int                      neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 208                                              u32 flags);
 209 extern void                     neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 210 extern int                      neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 211 extern int                      neigh_resolve_output(struct sk_buff *skb);
 212 extern int                      neigh_connected_output(struct sk_buff *skb);
 213 extern int                      neigh_compat_output(struct sk_buff *skb);
 214 extern struct neighbour         *neigh_event_ns(struct neigh_table *tbl,
 215                                                 u8 *lladdr, void *saddr,
 216                                                 struct net_device *dev);
 217
 218 extern struct neigh_parms       *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 219 extern void                     neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
 220
 221 static inline
 222 struct net                      *neigh_parms_net(const struct neigh_parms *parms)
 223 {
 224 #ifdef CONFIG_NET_NS
 225         return parms->net;
 226 #else
 227         return &init_net;
 228 #endif
 229 }
 230
 231 extern unsigned long            neigh_rand_reach_time(unsigned long base);
 232
 233 extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 234                                                struct sk_buff *skb);
 235 extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
 236 extern struct pneigh_entry      *__pneigh_lookup(struct neigh_table *tbl,
 237                                                  struct net *net,
 238                                                  const void *key,
 239                                                  struct net_device *dev);
 240 extern int                      pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
 241
 242 static inline
 243 struct net                      *pneigh_net(const struct pneigh_entry *pneigh)
 244 {
 245 #ifdef CONFIG_NET_NS
 246         return pneigh->net;
 247 #else
 248         return &init_net;
 249 #endif
 250 }
 251
 252 extern void neigh_app_ns(struct neighbour *n);
 253 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
 254 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
 255 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
 256
 257 struct neigh_seq_state {
 258         struct seq_net_private p;
 259         struct neigh_table *tbl;
 260         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 261                                 struct neighbour *n, loff_t *pos);
 262         unsigned int bucket;
 263         unsigned int flags;
 264 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 265 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
 266 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
 267 };
 268 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
 269 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 270 extern void neigh_seq_stop(struct seq_file *, void *);
 271
 272 extern int                      neigh_sysctl_register(struct net_device *dev,
 273                                                       struct neigh_parms *p,
 274                                                       int p_id, int pdev_id,
 275                                                       char *p_name,
 276                                                       proc_handler *proc_handler,
 277                                                       ctl_handler *strategy);
 278 extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
 279
 280 static inline void __neigh_parms_put(struct neigh_parms *parms)
 281 {
 282         atomic_dec(&parms->refcnt);
 283 }
 284
 285 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 286 {
 287         atomic_inc(&parms->refcnt);
 288         return parms;
 289 }
 290
 291 /*
 292  *      Neighbour references
 293  */
 294
 295 static inline void neigh_release(struct neighbour *neigh)
 296 {
 297         if (atomic_dec_and_test(&neigh->refcnt))
 298                 neigh_destroy(neigh);
 299 }
 300
 301 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 302 {
 303         if (neigh)
 304                 atomic_inc(&neigh->refcnt);
 305         return neigh;
 306 }
 307
 308 #define neigh_hold(n)   atomic_inc(&(n)->refcnt)
 309
 310 static inline void neigh_confirm(struct neighbour *neigh)
 311 {
 312         if (neigh)
 313                 neigh->confirmed = jiffies;
 314 }
 315
 316 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 317 {
 318         neigh->used = jiffies;
 319         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
 320                 return __neigh_event_send(neigh, skb);
 321         return 0;
 322 }
 323
 324 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
 325 {
 326         unsigned seq;
 327         int hh_len;
 328
 329         do {
 330                 int hh_alen;
 331
 332                 seq = read_seqbegin(&hh->hh_lock);
 333                 hh_len = hh->hh_len;
 334                 hh_alen = HH_DATA_ALIGN(hh_len);
 335                 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 336         } while (read_seqretry(&hh->hh_lock, seq));
 337
 338         skb_push(skb, hh_len);
 339         return hh->hh_output(skb);
 340 }
 341
 342 static inline struct neighbour *
 343 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 344 {
 345         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 346
 347         if (n || !creat)
 348                 return n;
 349
 350         n = neigh_create(tbl, pkey, dev);
 351         return IS_ERR(n) ? NULL : n;
 352 }
 353
 354 static inline struct neighbour *
 355 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 356   struct net_device *dev)
 357 {
 358         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 359
 360         if (n)
 361                 return n;
 362
 363         return neigh_create(tbl, pkey, dev);
 364 }
 365
 366 struct neighbour_cb {
 367         unsigned long sched_next;
 368         unsigned int flags;
 369 };
 370
 371 #define LOCALLY_ENQUEUED 0x1
 372
 373 #define NEIGH_CB(skb)   ((struct neighbour_cb *)(skb)->cb)
 374
 375 #endif