include/net/neighbour.h

   1 #ifndef _NET_NEIGHBOUR_H
   2 #define _NET_NEIGHBOUR_H
   3
   4 /*
   5  *      Generic neighbour manipulation
   6  *
   7  *      Authors:
   8  *      Pedro Roque             <pedro_m@yahoo.com>
   9  *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
  10  *
  11  *      Changes:
  12  *
  13  *      Harald Welte:           <laforge@gnumonks.org>
  14  *              - Add neighbour cache statistics like rtstat
  15  */
  16
  17 /* The following flags & states are exported to user space,
  18    so that they should be moved to include/linux/ directory.
  19  */
  20
  21 /*
  22  *      Neighbor Cache Entry Flags
  23  */
  24
  25 #define NTF_PROXY       0x08    /* == ATF_PUBL */
  26 #define NTF_ROUTER      0x80
  27
  28 /*
  29  *      Neighbor Cache Entry States.
  30  */
  31
  32 #define NUD_INCOMPLETE  0x01
  33 #define NUD_REACHABLE   0x02
  34 #define NUD_STALE       0x04
  35 #define NUD_DELAY       0x08
  36 #define NUD_PROBE       0x10
  37 #define NUD_FAILED      0x20
  38
  39 /* Dummy states */
  40 #define NUD_NOARP       0x40
  41 #define NUD_PERMANENT   0x80
  42 #define NUD_NONE        0x00
  43
  44 /* NUD_NOARP & NUD_PERMANENT are pseudostates, they never change
  45    and make no address resolution or NUD.
  46    NUD_PERMANENT is also cannot be deleted by garbage collectors.
  47  */
  48
  49 #ifdef __KERNEL__
  50
  51 #include <asm/atomic.h>
  52 #include <linux/skbuff.h>
  53 #include <linux/seq_file.h>
  54
  55 #define NUD_IN_TIMER    (NUD_INCOMPLETE|NUD_DELAY|NUD_PROBE)
  56 #define NUD_VALID       (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
  57 #define NUD_CONNECTED   (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
  58
  59 struct neigh_parms
  60 {
  61         struct neigh_parms *next;
  62         int     (*neigh_setup)(struct neighbour *);
  63         struct neigh_table *tbl;
  64         int     entries;
  65         void    *priv;
  66
  67         void    *sysctl_table;
  68
  69         int     base_reachable_time;
  70         int     retrans_time;
  71         int     gc_staletime;
  72         int     reachable_time;
  73         int     delay_probe_time;
  74
  75         int     queue_len;
  76         int     ucast_probes;
  77         int     app_probes;
  78         int     mcast_probes;
  79         int     anycast_delay;
  80         int     proxy_delay;
  81         int     proxy_qlen;
  82         int     locktime;
  83 };
  84
  85 struct neigh_statistics
  86 {
  87         unsigned long allocs;           /* number of allocated neighs */
  88         unsigned long destroys;         /* number of destroyed neighs */
  89         unsigned long hash_grows;       /* number of hash resizes */
  90
  91         unsigned long res_failed;       /* nomber of failed resolutions */
  92
  93         unsigned long lookups;          /* number of lookups */
  94         unsigned long hits;             /* number of hits (among lookups) */
  95
  96         unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
  97         unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
  98
  99         unsigned long periodic_gc_runs; /* number of periodic GC runs */
 100         unsigned long forced_gc_runs;   /* number of forced GC runs */
 101 };
 102
 103 #define NEIGH_CACHE_STAT_INC(tbl, field)                                \
 104                 ((tbl)->stats[smp_processor_id()].field++)
 105
 106 struct neighbour
 107 {
 108         struct neighbour        *next;
 109         struct neigh_table      *tbl;
 110         struct neigh_parms      *parms;
 111         struct net_device               *dev;
 112         unsigned long           used;
 113         unsigned long           confirmed;
 114         unsigned long           updated;
 115         __u8                    flags;
 116         __u8                    nud_state;
 117         __u8                    type;
 118         __u8                    dead;
 119         atomic_t                probes;
 120         rwlock_t                lock;
 121         unsigned char           ha[(MAX_ADDR_LEN+sizeof(unsigned long)-1)&~(sizeof(unsigned long)-1)];
 122         struct hh_cache         *hh;
 123         atomic_t                refcnt;
 124         int                     (*output)(struct sk_buff *skb);
 125         struct sk_buff_head     arp_queue;
 126         struct timer_list       timer;
 127         struct neigh_ops        *ops;
 128         u8                      primary_key[0];
 129 };
 130
 131 struct neigh_ops
 132 {
 133         int                     family;
 134         void                    (*destructor)(struct neighbour *);
 135         void                    (*solicit)(struct neighbour *, struct sk_buff*);
 136         void                    (*error_report)(struct neighbour *, struct sk_buff*);
 137         int                     (*output)(struct sk_buff*);
 138         int                     (*connected_output)(struct sk_buff*);
 139         int                     (*hh_output)(struct sk_buff*);
 140         int                     (*queue_xmit)(struct sk_buff*);
 141 };
 142
 143 struct pneigh_entry
 144 {
 145         struct pneigh_entry     *next;
 146         struct net_device               *dev;
 147         u8                      key[0];
 148 };
 149
 150 /*
 151  *      neighbour table manipulation
 152  */
 153
 154
 155 struct neigh_table
 156 {
 157         struct neigh_table      *next;
 158         int                     family;
 159         int                     entry_size;
 160         int                     key_len;
 161         __u32                   (*hash)(const void *pkey, const struct net_device *);
 162         int                     (*constructor)(struct neighbour *);
 163         int                     (*pconstructor)(struct pneigh_entry *);
 164         void                    (*pdestructor)(struct pneigh_entry *);
 165         void                    (*proxy_redo)(struct sk_buff *skb);
 166         char                    *id;
 167         struct neigh_parms      parms;
 168         /* HACK. gc_* shoul follow parms without a gap! */
 169         int                     gc_interval;
 170         int                     gc_thresh1;
 171         int                     gc_thresh2;
 172         int                     gc_thresh3;
 173         unsigned long           last_flush;
 174         struct timer_list       gc_timer;
 175         struct timer_list       proxy_timer;
 176         struct sk_buff_head     proxy_queue;
 177         atomic_t                entries;
 178         rwlock_t                lock;
 179         unsigned long           last_rand;
 180         struct neigh_parms      *parms_list;
 181         kmem_cache_t            *kmem_cachep;
 182         struct tasklet_struct   gc_task;
 183         struct neigh_statistics stats[NR_CPUS];
 184         struct neighbour        **hash_buckets;
 185         unsigned int            hash_mask;
 186         __u32                   hash_rnd;
 187         unsigned int            hash_chain_gc;
 188         struct pneigh_entry     **phash_buckets;
 189 #ifdef CONFIG_PROC_FS
 190         struct proc_dir_entry   *pde;
 191 #endif
 192 };
 193
 194 extern void                     neigh_table_init(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                                                    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, int override, int arp);
 207 extern void                     neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 208 extern int                      neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 209 extern int                      neigh_resolve_output(struct sk_buff *skb);
 210 extern int                      neigh_connected_output(struct sk_buff *skb);
 211 extern int                      neigh_compat_output(struct sk_buff *skb);
 212 extern struct neighbour         *neigh_event_ns(struct neigh_table *tbl,
 213                                                 u8 *lladdr, void *saddr,
 214                                                 struct net_device *dev);
 215
 216 extern struct neigh_parms       *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 217 extern void                     neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
 218 extern unsigned long            neigh_rand_reach_time(unsigned long base);
 219
 220 extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 221                                                struct sk_buff *skb);
 222 extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, const void *key, struct net_device *dev, int creat);
 223 extern int                      pneigh_delete(struct neigh_table *tbl, const void *key, struct net_device *dev);
 224
 225 struct netlink_callback;
 226 struct nlmsghdr;
 227 extern int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
 228 extern int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 229 extern int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
 230 extern void neigh_app_ns(struct neighbour *n);
 231
 232 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
 233 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
 234 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
 235
 236 struct neigh_seq_state {
 237         struct neigh_table *tbl;
 238         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 239                                 struct neighbour *n, loff_t *pos);
 240         unsigned int bucket;
 241         unsigned int flags;
 242 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 243 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
 244 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
 245 };
 246 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
 247 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 248 extern void neigh_seq_stop(struct seq_file *, void *);
 249
 250 extern int                      neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
 251                                                       int p_id, int pdev_id, char *p_name);
 252 extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
 253
 254 /*
 255  *      Neighbour references
 256  */
 257
 258 static inline void neigh_release(struct neighbour *neigh)
 259 {
 260         if (atomic_dec_and_test(&neigh->refcnt))
 261                 neigh_destroy(neigh);
 262 }
 263
 264 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 265 {
 266         if (neigh)
 267                 atomic_inc(&neigh->refcnt);
 268         return neigh;
 269 }
 270
 271 #define neigh_hold(n)   atomic_inc(&(n)->refcnt)
 272
 273 static inline void neigh_confirm(struct neighbour *neigh)
 274 {
 275         if (neigh)
 276                 neigh->confirmed = jiffies;
 277 }
 278
 279 static inline int neigh_is_connected(struct neighbour *neigh)
 280 {
 281         return neigh->nud_state&NUD_CONNECTED;
 282 }
 283
 284 static inline int neigh_is_valid(struct neighbour *neigh)
 285 {
 286         return neigh->nud_state&NUD_VALID;
 287 }
 288
 289 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 290 {
 291         neigh->used = jiffies;
 292         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
 293                 return __neigh_event_send(neigh, skb);
 294         return 0;
 295 }
 296
 297 static inline struct neighbour *
 298 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 299 {
 300         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 301
 302         if (n || !creat)
 303                 return n;
 304
 305         n = neigh_create(tbl, pkey, dev);
 306         return IS_ERR(n) ? NULL : n;
 307 }
 308
 309 static inline struct neighbour *
 310 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 311   struct net_device *dev)
 312 {
 313         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 314
 315         if (n)
 316                 return n;
 317
 318         return neigh_create(tbl, pkey, dev);
 319 }
 320
 321 #endif
 322 #endif
 323
 324