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   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         struct net *net;
  42         struct net_device *dev;
  43         struct neigh_parms *next;
  44         int     (*neigh_setup)(struct neighbour *);
  45         void    (*neigh_cleanup)(struct neighbour *);
  46         struct neigh_table *tbl;
  47
  48         void    *sysctl_table;
  49
  50         int dead;
  51         atomic_t refcnt;
  52         struct rcu_head rcu_head;
  53
  54         int     base_reachable_time;
  55         int     retrans_time;
  56         int     gc_staletime;
  57         int     reachable_time;
  58         int     delay_probe_time;
  59
  60         int     queue_len;
  61         int     ucast_probes;
  62         int     app_probes;
  63         int     mcast_probes;
  64         int     anycast_delay;
  65         int     proxy_delay;
  66         int     proxy_qlen;
  67         int     locktime;
  68 };
  69
  70 struct neigh_statistics
  71 {
  72         unsigned long allocs;           /* number of allocated neighs */
  73         unsigned long destroys;         /* number of destroyed neighs */
  74         unsigned long hash_grows;       /* number of hash resizes */
  75
  76         unsigned long res_failed;       /* nomber of failed resolutions */
  77
  78         unsigned long lookups;          /* number of lookups */
  79         unsigned long hits;             /* number of hits (among lookups) */
  80
  81         unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
  82         unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
  83
  84         unsigned long periodic_gc_runs; /* number of periodic GC runs */
  85         unsigned long forced_gc_runs;   /* number of forced GC runs */
  86 };
  87
  88 #define NEIGH_CACHE_STAT_INC(tbl, field)                                \
  89         do {                                                            \
  90                 preempt_disable();                                      \
  91                 (per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
  92                 preempt_enable();                                       \
  93         } while (0)
  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         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         struct net              *net;
 135         struct net_device       *dev;
 136         u8                      flags;
 137         u8                      key[0];
 138 };
 139
 140 /*
 141  *      neighbour table manipulation
 142  */
 143
 144
 145 struct neigh_table
 146 {
 147         struct neigh_table      *next;
 148         int                     family;
 149         int                     entry_size;
 150         int                     key_len;
 151         __u32                   (*hash)(const void *pkey, const struct net_device *);
 152         int                     (*constructor)(struct neighbour *);
 153         int                     (*pconstructor)(struct pneigh_entry *);
 154         void                    (*pdestructor)(struct pneigh_entry *);
 155         void                    (*proxy_redo)(struct sk_buff *skb);
 156         char                    *id;
 157         struct neigh_parms      parms;
 158         /* HACK. gc_* shoul follow parms without a gap! */
 159         int                     gc_interval;
 160         int                     gc_thresh1;
 161         int                     gc_thresh2;
 162         int                     gc_thresh3;
 163         unsigned long           last_flush;
 164         struct timer_list       gc_timer;
 165         struct timer_list       proxy_timer;
 166         struct sk_buff_head     proxy_queue;
 167         atomic_t                entries;
 168         rwlock_t                lock;
 169         unsigned long           last_rand;
 170         struct kmem_cache               *kmem_cachep;
 171         struct neigh_statistics *stats;
 172         struct neighbour        **hash_buckets;
 173         unsigned int            hash_mask;
 174         __u32                   hash_rnd;
 175         unsigned int            hash_chain_gc;
 176         struct pneigh_entry     **phash_buckets;
 177 #ifdef CONFIG_PROC_FS
 178         struct proc_dir_entry   *pde;
 179 #endif
 180 };
 181
 182 /* flags for neigh_update() */
 183 #define NEIGH_UPDATE_F_OVERRIDE                 0x00000001
 184 #define NEIGH_UPDATE_F_WEAK_OVERRIDE            0x00000002
 185 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER        0x00000004
 186 #define NEIGH_UPDATE_F_ISROUTER                 0x40000000
 187 #define NEIGH_UPDATE_F_ADMIN                    0x80000000
 188
 189 extern void                     neigh_table_init(struct neigh_table *tbl);
 190 extern void                     neigh_table_init_no_netlink(struct neigh_table *tbl);
 191 extern int                      neigh_table_clear(struct neigh_table *tbl);
 192 extern struct neighbour *       neigh_lookup(struct neigh_table *tbl,
 193                                              const void *pkey,
 194                                              struct net_device *dev);
 195 extern struct neighbour *       neigh_lookup_nodev(struct neigh_table *tbl,
 196                                                    struct net *net,
 197                                                    const void *pkey);
 198 extern struct neighbour *       neigh_create(struct neigh_table *tbl,
 199                                              const void *pkey,
 200                                              struct net_device *dev);
 201 extern void                     neigh_destroy(struct neighbour *neigh);
 202 extern int                      __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
 203 extern int                      neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 204                                              u32 flags);
 205 extern void                     neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 206 extern int                      neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 207 extern int                      neigh_resolve_output(struct sk_buff *skb);
 208 extern int                      neigh_connected_output(struct sk_buff *skb);
 209 extern int                      neigh_compat_output(struct sk_buff *skb);
 210 extern struct neighbour         *neigh_event_ns(struct neigh_table *tbl,
 211                                                 u8 *lladdr, void *saddr,
 212                                                 struct net_device *dev);
 213
 214 extern struct neigh_parms       *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
 215 extern void                     neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
 216 extern unsigned long            neigh_rand_reach_time(unsigned long base);
 217
 218 extern void                     pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 219                                                struct sk_buff *skb);
 220 extern struct pneigh_entry      *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
 221 extern int                      pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
 222
 223 extern void neigh_app_ns(struct neighbour *n);
 224 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
 225 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
 226 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
 227
 228 struct neigh_seq_state {
 229         struct seq_net_private p;
 230         struct neigh_table *tbl;
 231         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
 232                                 struct neighbour *n, loff_t *pos);
 233         unsigned int bucket;
 234         unsigned int flags;
 235 #define NEIGH_SEQ_NEIGH_ONLY    0x00000001
 236 #define NEIGH_SEQ_IS_PNEIGH     0x00000002
 237 #define NEIGH_SEQ_SKIP_NOARP    0x00000004
 238 };
 239 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
 240 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
 241 extern void neigh_seq_stop(struct seq_file *, void *);
 242
 243 extern int                      neigh_sysctl_register(struct net_device *dev,
 244                                                       struct neigh_parms *p,
 245                                                       int p_id, int pdev_id,
 246                                                       char *p_name,
 247                                                       proc_handler *proc_handler,
 248                                                       ctl_handler *strategy);
 249 extern void                     neigh_sysctl_unregister(struct neigh_parms *p);
 250
 251 static inline void __neigh_parms_put(struct neigh_parms *parms)
 252 {
 253         atomic_dec(&parms->refcnt);
 254 }
 255
 256 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 257 {
 258         atomic_inc(&parms->refcnt);
 259         return parms;
 260 }
 261
 262 /*
 263  *      Neighbour references
 264  */
 265
 266 static inline void neigh_release(struct neighbour *neigh)
 267 {
 268         if (atomic_dec_and_test(&neigh->refcnt))
 269                 neigh_destroy(neigh);
 270 }
 271
 272 static inline struct neighbour * neigh_clone(struct neighbour *neigh)
 273 {
 274         if (neigh)
 275                 atomic_inc(&neigh->refcnt);
 276         return neigh;
 277 }
 278
 279 #define neigh_hold(n)   atomic_inc(&(n)->refcnt)
 280
 281 static inline void neigh_confirm(struct neighbour *neigh)
 282 {
 283         if (neigh)
 284                 neigh->confirmed = jiffies;
 285 }
 286
 287 static inline int neigh_is_connected(struct neighbour *neigh)
 288 {
 289         return neigh->nud_state&NUD_CONNECTED;
 290 }
 291
 292
 293 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 294 {
 295         neigh->used = jiffies;
 296         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
 297                 return __neigh_event_send(neigh, skb);
 298         return 0;
 299 }
 300
 301 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
 302 {
 303         unsigned seq;
 304         int hh_len;
 305
 306         do {
 307                 int hh_alen;
 308
 309                 seq = read_seqbegin(&hh->hh_lock);
 310                 hh_len = hh->hh_len;
 311                 hh_alen = HH_DATA_ALIGN(hh_len);
 312                 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 313         } while (read_seqretry(&hh->hh_lock, seq));
 314
 315         skb_push(skb, hh_len);
 316         return hh->hh_output(skb);
 317 }
 318
 319 static inline struct neighbour *
 320 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
 321 {
 322         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 323
 324         if (n || !creat)
 325                 return n;
 326
 327         n = neigh_create(tbl, pkey, dev);
 328         return IS_ERR(n) ? NULL : n;
 329 }
 330
 331 static inline struct neighbour *
 332 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
 333   struct net_device *dev)
 334 {
 335         struct neighbour *n = neigh_lookup(tbl, pkey, dev);
 336
 337         if (n)
 338                 return n;
 339
 340         return neigh_create(tbl, pkey, dev);
 341 }
 342
 343 struct neighbour_cb {
 344         unsigned long sched_next;
 345         unsigned int flags;
 346 };
 347
 348 #define LOCALLY_ENQUEUED 0x1
 349
 350 #define NEIGH_CB(skb)   ((struct neighbour_cb *)(skb)->cb)
 351
 352 #endif