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)                                \
  94         do {                                                            \
  95                 preempt_disable();                                      \
  96                 (per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
  97                 preempt_enable();                                       \
  98         } while (0)
  99
 100 struct neighbour
 101 {
 102         struct neighbour        *next;
 103         struct neigh_table      *tbl;
 104         struct neigh_parms      *parms;
 105         struct net_device               *dev;
 106         unsigned long           used;
 107         unsigned long           confirmed;
 108         unsigned long           updated;
 109         __u8                    flags;
 110         __u8                    nud_state;
 111         __u8                    type;
 112         __u8                    dead;
 113         atomic_t                probes;
 114         rwlock_t                lock;
 115         unsigned char           ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
 116         struct hh_cache         *hh;
 117         atomic_t                refcnt;
 118         int                     (*output)(struct sk_buff *skb);
 119         struct sk_buff_head     arp_queue;
 120         struct timer_list       timer;
 121         const struct neigh_ops  *ops;
 122         u8                      primary_key[0];
 123 };
 124
 125 struct neigh_ops
 126 {
 127         int                     family;
 128         void                    (*solicit)(struct neighbour *, struct sk_buff*);
 129         void                    (*error_report)(struct neighbour *, struct sk_buff*);
 130         int                     (*output)(struct sk_buff*);
 131         int                     (*connected_output)(struct sk_buff*);
 132         int                     (*hh_output)(struct sk_buff*);
 133         int                     (*queue_xmit)(struct sk_buff*);
 134 };
 135
 136 struct pneigh_entry
 137 {
 138         struct pneigh_entry     *next;
 139 #ifdef CONFIG_NET_NS
 140         struct net              *net;
 141 #endif
 142         struct net_device       *dev;
 143         u8                      flags;
 144         u8                      key[0];
 145 };
 146
 147 /*
 148  *      neighbour table manipulation
 149  */
 150
 151
 152 struct neigh_table
 153 {
 154         struct neigh_table      *next;
 155         int                     family;
 156         int                     entry_size;
 157         int                     key_len;
 158         __u32                   (*hash)(const void *pkey, const struct net_device *);
 159         int                     (*constructor)(struct neighbour *);
 160         int                     (*pconstructor)(struct pneigh_entry *);
 161         void                    (*pdestructor)(struct pneigh_entry *);
 162         void                    (*proxy_redo)(struct sk_buff *skb);
 163         char                    *id;
 164         struct neigh_parms      parms;
 165         /* HACK. gc_* shoul follow parms without a gap! */
 166         int                     gc_interval;
 167         int                     gc_thresh1;
 168         int                     gc_thresh2;
 169         int                     gc_thresh3;
 170         unsigned long           last_flush;
 171         struct delayed_work     gc_work;
 172         struct timer_list       proxy_timer;
 173         struct sk_buff_head     proxy_queue;
 174         atomic_t                entries;
 175         rwlock_t                lock;
 176         unsigned long           last_rand;
 177         struct kmem_cache               *kmem_cachep;
 178         struct neigh_statistics *stats;
 179         struct neighbour        **hash_buckets;
 180         unsigned int            hash_mask;
 181         __u32                   hash_rnd;
 182         struct pneigh_entry     **phash_buckets;
 183 };
 184
 185 /* flags for neigh_update() */
 186 #define NEIGH_UPDATE_F_OVERRIDE                 0x00000001
 187 #define NEIGH_UPDATE_F_WEAK_OVERRIDE            0x00000002
 188 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        0x00000004
 189 #define NEIGH_UPDATE_F_ISROUTER                 0x40000000
 190 #define NEIGH_UPDATE_F_ADMIN                    0x80000000
 191
 192 extern void                     neigh_table_init(struct neigh_table *tbl);
 193 extern void                     neigh_table_init_no_netlink(struct neigh_table *tbl);
 194 extern int                      neigh_table_clear(struct neigh_table *tbl);
 195 extern struct neighbour *       neigh_lookup(struct neigh_table *tbl,
 196                                              const void *pkey,
 197                                              struct net_device *dev);
 198 extern struct neighbour *       neigh_lookup_nodev(struct neigh_table *tbl,
 199                                                    struct net *net,
 200                                                    const void *pkey);
 201 extern struct neighbour *       neigh_create(struct neigh_table *tbl,
 202                                              const void *pkey,
 203                                              struct net_device *dev);
 204 extern void                     neigh_destroy(struct neighbour *neigh);
 205 extern int                      __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
 206 extern int                      neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 207                                              u32 flags);
 208 extern void                     neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 209 extern int                      neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 210 extern int                      neigh_resolve_output(struct sk_buff *skb);
 211 extern int                      neigh_connected_output(struct sk_buff *skb);
 212 extern int                      neigh_compat_output(struct sk_buff *skb);
 213 extern struct neighbour         *neigh_event_ns(struct neigh_table *tbl,
 214                                                 u8 *lladdr, void *saddr,
 215                                                 struct net_device *dev);
 216
 217 extern struct neigh_parms       *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 218 extern void                     neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
 219
 220 static inline
 221 struct net                      *neigh_parms_net(const struct neigh_parms *parms)
 222 {
 223         return read_pnet(&parms->net);
 224 }
 225
 226 extern unsigned long            neigh_rand_reach_time(unsigned long base);
 227
 228 extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 229                                                struct sk_buff *skb);
 230 extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
 231 extern struct pneigh_entry      *__pneigh_lookup(struct neigh_table *tbl,
 232                                                  struct net *net,
 233                                                  const void *key,
 234                                                  struct net_device *dev);
 235 extern int                      pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
 236
 237 static inline
 238 struct net                      *pneigh_net(const struct pneigh_entry *pneigh)
 239 {
 240         return read_pnet(&pneigh->net);
 241 }
 242
 243 extern void neigh_app_ns(struct neighbour *n);
 244 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
 245 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
 246 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
 247
 248 struct neigh_seq_state {
 249         struct seq_net_private p;
 250         struct neigh_table *tbl;
 251         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 252                                 struct neighbour *n, loff_t *pos);
 253         unsigned int bucket;
 254         unsigned int flags;
 255 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 256 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
 257 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
 258 };
 259 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
 260 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 261 extern void neigh_seq_stop(struct seq_file *, void *);
 262
 263 extern int                      neigh_sysctl_register(struct net_device *dev,
 264                                                       struct neigh_parms *p,
 265                                                       int p_id, int pdev_id,
 266                                                       char *p_name,
 267                                                       proc_handler *proc_handler,
 268                                                       ctl_handler *strategy);
 269 extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
 270
 271 static inline void __neigh_parms_put(struct neigh_parms *parms)
 272 {
 273         atomic_dec(&parms->refcnt);
 274 }
 275
 276 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 277 {
 278         atomic_inc(&parms->refcnt);
 279         return parms;
 280 }
 281
 282 /*
 283  *      Neighbour references
 284  */
 285
 286 static inline void neigh_release(struct neighbour *neigh)
 287 {
 288         if (atomic_dec_and_test(&neigh->refcnt))
 289                 neigh_destroy(neigh);
 290 }
 291
 292 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 293 {
 294         if (neigh)
 295                 atomic_inc(&neigh->refcnt);
 296         return neigh;
 297 }
 298
 299 #define neigh_hold(n)   atomic_inc(&(n)->refcnt)
 300
 301 static inline void neigh_confirm(struct neighbour *neigh)
 302 {
 303         if (neigh)
 304                 neigh->confirmed = jiffies;
 305 }
 306
 307 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 308 {
 309         neigh->used = jiffies;
 310         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
 311                 return __neigh_event_send(neigh, skb);
 312         return 0;
 313 }
 314
 315 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
 316 {
 317         unsigned seq;
 318         int hh_len;
 319
 320         do {
 321                 int hh_alen;
 322
 323                 seq = read_seqbegin(&hh->hh_lock);
 324                 hh_len = hh->hh_len;
 325                 hh_alen = HH_DATA_ALIGN(hh_len);
 326                 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 327         } while (read_seqretry(&hh->hh_lock, seq));
 328
 329         skb_push(skb, hh_len);
 330         return hh->hh_output(skb);
 331 }
 332
 333 static inline struct neighbour *
 334 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 335 {
 336         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 337
 338         if (n || !creat)
 339                 return n;
 340
 341         n = neigh_create(tbl, pkey, dev);
 342         return IS_ERR(n) ? NULL : n;
 343 }
 344
 345 static inline struct neighbour *
 346 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 347   struct net_device *dev)
 348 {
 349         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 350
 351         if (n)
 352                 return n;
 353
 354         return neigh_create(tbl, pkey, dev);
 355 }
 356
 357 struct neighbour_cb {
 358         unsigned long sched_next;
 359         unsigned int flags;
 360 };
 361
 362 #define LOCALLY_ENQUEUED 0x1
 363
 364 #define NEIGH_CB(skb)   ((struct neighbour_cb *)(skb)->cb)
 365
 366 #endif