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
  28 #define NUD_IN_TIMER    (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
  29 #define NUD_VALID       (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
  30 #define NUD_CONNECTED   (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
  31
  32 struct neighbour;
  33
  34 struct neigh_parms
  35 {
  36         struct net_device *dev;
  37         struct neigh_parms *next;
  38         int     (*neigh_setup)(struct neighbour *);
  39         void    (*neigh_destructor)(struct neighbour *);
  40         struct neigh_table *tbl;
  41
  42         void    *sysctl_table;
  43
  44         int dead;
  45         atomic_t refcnt;
  46         struct rcu_head rcu_head;
  47
  48         int     base_reachable_time;
  49         int     retrans_time;
  50         int     gc_staletime;
  51         int     reachable_time;
  52         int     delay_probe_time;
  53
  54         int     queue_len;
  55         int     ucast_probes;
  56         int     app_probes;
  57         int     mcast_probes;
  58         int     anycast_delay;
  59         int     proxy_delay;
  60         int     proxy_qlen;
  61         int     locktime;
  62 };
  63
  64 struct neigh_statistics
  65 {
  66         unsigned long allocs;           /* number of allocated neighs */
  67         unsigned long destroys;         /* number of destroyed neighs */
  68         unsigned long hash_grows;       /* number of hash resizes */
  69
  70         unsigned long res_failed;       /* nomber of failed resolutions */
  71
  72         unsigned long lookups;          /* number of lookups */
  73         unsigned long hits;             /* number of hits (among lookups) */
  74
  75         unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
  76         unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
  77
  78         unsigned long periodic_gc_runs; /* number of periodic GC runs */
  79         unsigned long forced_gc_runs;   /* number of forced GC runs */
  80 };
  81
  82 #define NEIGH_CACHE_STAT_INC(tbl, field)                                \
  83         do {                                                            \
  84                 preempt_disable();                                      \
  85                 (per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
  86                 preempt_enable();                                       \
  87         } while (0)
  88
  89 struct neighbour
  90 {
  91         struct neighbour        *next;
  92         struct neigh_table      *tbl;
  93         struct neigh_parms      *parms;
  94         struct net_device               *dev;
  95         unsigned long           used;
  96         unsigned long           confirmed;
  97         unsigned long           updated;
  98         __u8                    flags;
  99         __u8                    nud_state;
 100         __u8                    type;
 101         __u8                    dead;
 102         atomic_t                probes;
 103         rwlock_t                lock;
 104         unsigned char           ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
 105         struct hh_cache         *hh;
 106         atomic_t                refcnt;
 107         int                     (*output)(struct sk_buff *skb);
 108         struct sk_buff_head     arp_queue;
 109         struct timer_list       timer;
 110         struct neigh_ops        *ops;
 111         u8                      primary_key[0];
 112 };
 113
 114 struct neigh_ops
 115 {
 116         int                     family;
 117         void                    (*solicit)(struct neighbour *, struct sk_buff*);
 118         void                    (*error_report)(struct neighbour *, struct sk_buff*);
 119         int                     (*output)(struct sk_buff*);
 120         int                     (*connected_output)(struct sk_buff*);
 121         int                     (*hh_output)(struct sk_buff*);
 122         int                     (*queue_xmit)(struct sk_buff*);
 123 };
 124
 125 struct pneigh_entry
 126 {
 127         struct pneigh_entry     *next;
 128         struct net_device               *dev;
 129         u8                      flags;
 130         u8                      key[0];
 131 };
 132
 133 /*
 134  *      neighbour table manipulation
 135  */
 136
 137
 138 struct neigh_table
 139 {
 140         struct neigh_table      *next;
 141         int                     family;
 142         int                     entry_size;
 143         int                     key_len;
 144         __u32                   (*hash)(const void *pkey, const struct net_device *);
 145         int                     (*constructor)(struct neighbour *);
 146         int                     (*pconstructor)(struct pneigh_entry *);
 147         void                    (*pdestructor)(struct pneigh_entry *);
 148         void                    (*proxy_redo)(struct sk_buff *skb);
 149         char                    *id;
 150         struct neigh_parms      parms;
 151         /* HACK. gc_* shoul follow parms without a gap! */
 152         int                     gc_interval;
 153         int                     gc_thresh1;
 154         int                     gc_thresh2;
 155         int                     gc_thresh3;
 156         unsigned long           last_flush;
 157         struct timer_list       gc_timer;
 158         struct timer_list       proxy_timer;
 159         struct sk_buff_head     proxy_queue;
 160         atomic_t                entries;
 161         rwlock_t                lock;
 162         unsigned long           last_rand;
 163         struct kmem_cache               *kmem_cachep;
 164         struct neigh_statistics *stats;
 165         struct neighbour        **hash_buckets;
 166         unsigned int            hash_mask;
 167         __u32                   hash_rnd;
 168         unsigned int            hash_chain_gc;
 169         struct pneigh_entry     **phash_buckets;
 170 #ifdef CONFIG_PROC_FS
 171         struct proc_dir_entry   *pde;
 172 #endif
 173 };
 174
 175 /* flags for neigh_update() */
 176 #define NEIGH_UPDATE_F_OVERRIDE                 0x00000001
 177 #define NEIGH_UPDATE_F_WEAK_OVERRIDE            0x00000002
 178 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        0x00000004
 179 #define NEIGH_UPDATE_F_ISROUTER                 0x40000000
 180 #define NEIGH_UPDATE_F_ADMIN                    0x80000000
 181
 182 extern void                     neigh_table_init(struct neigh_table *tbl);
 183 extern void                     neigh_table_init_no_netlink(struct neigh_table *tbl);
 184 extern int                      neigh_table_clear(struct neigh_table *tbl);
 185 extern struct neighbour *       neigh_lookup(struct neigh_table *tbl,
 186                                              const void *pkey,
 187                                              struct net_device *dev);
 188 extern struct neighbour *       neigh_lookup_nodev(struct neigh_table *tbl,
 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 extern void                     neigh_parms_destroy(struct neigh_parms *parms);
 209 extern unsigned long            neigh_rand_reach_time(unsigned long base);
 210
 211 extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 212                                                struct sk_buff *skb);
 213 extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, const void *key, struct net_device *dev, int creat);
 214 extern int                      pneigh_delete(struct neigh_table *tbl, const void *key, struct net_device *dev);
 215
 216 struct netlink_callback;
 217 struct nlmsghdr;
 218 extern int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
 219 extern int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 220 extern int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 221 extern void neigh_app_ns(struct neighbour *n);
 222
 223 extern int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
 224 extern int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 225
 226 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
 227 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
 228 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
 229
 230 struct neigh_seq_state {
 231         struct neigh_table *tbl;
 232         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 233                                 struct neighbour *n, loff_t *pos);
 234         unsigned int bucket;
 235         unsigned int flags;
 236 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 237 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
 238 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
 239 };
 240 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
 241 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 242 extern void neigh_seq_stop(struct seq_file *, void *);
 243
 244 extern int                      neigh_sysctl_register(struct net_device *dev,
 245                                                       struct neigh_parms *p,
 246                                                       int p_id, int pdev_id,
 247                                                       char *p_name,
 248                                                       proc_handler *proc_handler,
 249                                                       ctl_handler *strategy);
 250 extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
 251
 252 static inline void __neigh_parms_put(struct neigh_parms *parms)
 253 {
 254         atomic_dec(&parms->refcnt);
 255 }
 256
 257 static inline void neigh_parms_put(struct neigh_parms *parms)
 258 {
 259         if (atomic_dec_and_test(&parms->refcnt))
 260                 neigh_parms_destroy(parms);
 261 }
 262
 263 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 264 {
 265         atomic_inc(&parms->refcnt);
 266         return parms;
 267 }
 268
 269 /*
 270  *      Neighbour references
 271  */
 272
 273 static inline void neigh_release(struct neighbour *neigh)
 274 {
 275         if (atomic_dec_and_test(&neigh->refcnt))
 276                 neigh_destroy(neigh);
 277 }
 278
 279 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 280 {
 281         if (neigh)
 282                 atomic_inc(&neigh->refcnt);
 283         return neigh;
 284 }
 285
 286 #define neigh_hold(n)   atomic_inc(&(n)->refcnt)
 287
 288 static inline void neigh_confirm(struct neighbour *neigh)
 289 {
 290         if (neigh)
 291                 neigh->confirmed = jiffies;
 292 }
 293
 294 static inline int neigh_is_connected(struct neighbour *neigh)
 295 {
 296         return neigh->nud_state&NUD_CONNECTED;
 297 }
 298
 299 static inline int neigh_is_valid(struct neighbour *neigh)
 300 {
 301         return neigh->nud_state&NUD_VALID;
 302 }
 303
 304 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 305 {
 306         neigh->used = jiffies;
 307         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
 308                 return __neigh_event_send(neigh, skb);
 309         return 0;
 310 }
 311
 312 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
 313 {
 314         unsigned seq;
 315         int hh_len;
 316
 317         do {
 318                 int hh_alen;
 319
 320                 seq = read_seqbegin(&hh->hh_lock);
 321                 hh_len = hh->hh_len;
 322                 hh_alen = HH_DATA_ALIGN(hh_len);
 323                 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 324         } while (read_seqretry(&hh->hh_lock, seq));
 325
 326         skb_push(skb, hh_len);
 327         return hh->hh_output(skb);
 328 }
 329
 330 static inline struct neighbour *
 331 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 332 {
 333         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 334
 335         if (n || !creat)
 336                 return n;
 337
 338         n = neigh_create(tbl, pkey, dev);
 339         return IS_ERR(n) ? NULL : n;
 340 }
 341
 342 static inline struct neighbour *
 343 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 344   struct net_device *dev)
 345 {
 346         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 347
 348         if (n)
 349                 return n;
 350
 351         return neigh_create(tbl, pkey, dev);
 352 }
 353
 354 struct neighbour_cb {
 355         unsigned long sched_next;
 356         unsigned int flags;
 357 };
 358
 359 #define LOCALLY_ENQUEUED 0x1
 360
 361 #define NEIGH_CB(skb)   ((struct neighbour_cb *)(skb)->cb)
 362
 363 #endif