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 <linux/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 #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_bytes; 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 unsigned long allocs; /* number of allocated neighs */ 74 unsigned long destroys; /* number of destroyed neighs */ 75 unsigned long hash_grows; /* number of hash resizes */ 76 77 unsigned long res_failed; /* number of failed resolutions */ 78 79 unsigned long lookups; /* number of lookups */ 80 unsigned long hits; /* number of hits (among lookups) */ 81 82 unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */ 83 unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */ 84 85 unsigned long periodic_gc_runs; /* number of periodic GC runs */ 86 unsigned long forced_gc_runs; /* number of forced GC runs */ 87 88 unsigned long unres_discards; /* number of unresolved drops */ 89 }; 90 91 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field) 92 93 struct neighbour { 94 struct neighbour __rcu *next; 95 struct neigh_table *tbl; 96 struct neigh_parms *parms; 97 unsigned long confirmed; 98 unsigned long updated; 99 rwlock_t lock; 100 atomic_t refcnt; 101 struct sk_buff_head arp_queue; 102 unsigned int arp_queue_len_bytes; 103 struct timer_list timer; 104 unsigned long used; 105 atomic_t probes; 106 __u8 flags; 107 __u8 nud_state; 108 __u8 type; 109 __u8 dead; 110 seqlock_t ha_lock; 111 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))]; 112 struct hh_cache hh; 113 int (*output)(struct neighbour *, struct sk_buff *); 114 const struct neigh_ops *ops; 115 struct rcu_head rcu; 116 struct net_device *dev; 117 u8 primary_key[0]; 118 }; 119 120 struct neigh_ops { 121 int family; 122 void (*solicit)(struct neighbour *, struct sk_buff *); 123 void (*error_report)(struct neighbour *, struct sk_buff *); 124 int (*output)(struct neighbour *, struct sk_buff *); 125 int (*connected_output)(struct neighbour *, struct sk_buff *); 126 }; 127 128 struct pneigh_entry { 129 struct pneigh_entry *next; 130 #ifdef CONFIG_NET_NS 131 struct net *net; 132 #endif 133 struct net_device *dev; 134 u8 flags; 135 u8 key[0]; 136 }; 137 138 /* 139 * neighbour table manipulation 140 */ 141 142 #define NEIGH_NUM_HASH_RND 4 143 144 struct neigh_hash_table { 145 struct neighbour __rcu **hash_buckets; 146 unsigned int hash_shift; 147 __u32 hash_rnd[NEIGH_NUM_HASH_RND]; 148 struct rcu_head rcu; 149 }; 150 151 152 struct neigh_table { 153 struct neigh_table *next; 154 int family; 155 int entry_size; 156 int key_len; 157 __u32 (*hash)(const void *pkey, 158 const struct net_device *dev, 159 __u32 *hash_rnd); 160 int (*constructor)(struct neighbour *); 161 int (*pconstructor)(struct pneigh_entry *); 162 void (*pdestructor)(struct pneigh_entry *); 163 void (*proxy_redo)(struct sk_buff *skb); 164 char *id; 165 struct neigh_parms parms; 166 /* HACK. gc_* should follow parms without a gap! */ 167 int gc_interval; 168 int gc_thresh1; 169 int gc_thresh2; 170 int gc_thresh3; 171 unsigned long last_flush; 172 struct delayed_work gc_work; 173 struct timer_list proxy_timer; 174 struct sk_buff_head proxy_queue; 175 atomic_t entries; 176 rwlock_t lock; 177 unsigned long last_rand; 178 struct neigh_statistics __percpu *stats; 179 struct neigh_hash_table __rcu *nht; 180 struct pneigh_entry **phash_buckets; 181 }; 182 183 #define NEIGH_PRIV_ALIGN sizeof(long long) 184 185 static inline void *neighbour_priv(const struct neighbour *n) 186 { 187 return (char *)n + ALIGN(sizeof(*n) + n->tbl->key_len, NEIGH_PRIV_ALIGN); 188 } 189 190 /* flags for neigh_update() */ 191 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 192 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 193 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 194 #define NEIGH_UPDATE_F_ISROUTER 0x40000000 195 #define NEIGH_UPDATE_F_ADMIN 0x80000000 196 197 extern void neigh_table_init(struct neigh_table *tbl); 198 extern int neigh_table_clear(struct neigh_table *tbl); 199 extern struct neighbour * neigh_lookup(struct neigh_table *tbl, 200 const void *pkey, 201 struct net_device *dev); 202 extern struct neighbour * neigh_lookup_nodev(struct neigh_table *tbl, 203 struct net *net, 204 const void *pkey); 205 extern struct neighbour * __neigh_create(struct neigh_table *tbl, 206 const void *pkey, 207 struct net_device *dev, 208 bool want_ref); 209 static inline struct neighbour *neigh_create(struct neigh_table *tbl, 210 const void *pkey, 211 struct net_device *dev) 212 { 213 return __neigh_create(tbl, pkey, dev, true); 214 } 215 extern void neigh_destroy(struct neighbour *neigh); 216 extern int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 217 extern int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 218 u32 flags); 219 extern void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 220 extern int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 221 extern int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 222 extern int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 223 extern int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb); 224 extern int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 225 extern struct neighbour *neigh_event_ns(struct neigh_table *tbl, 226 u8 *lladdr, void *saddr, 227 struct net_device *dev); 228 229 extern struct neigh_parms *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl); 230 extern void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 231 232 static inline 233 struct net *neigh_parms_net(const struct neigh_parms *parms) 234 { 235 return read_pnet(&parms->net); 236 } 237 238 extern unsigned long neigh_rand_reach_time(unsigned long base); 239 240 extern void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 241 struct sk_buff *skb); 242 extern struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat); 243 extern struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, 244 struct net *net, 245 const void *key, 246 struct net_device *dev); 247 extern int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); 248 249 static inline 250 struct net *pneigh_net(const struct pneigh_entry *pneigh) 251 { 252 return read_pnet(&pneigh->net); 253 } 254 255 extern void neigh_app_ns(struct neighbour *n); 256 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie); 257 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *)); 258 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *)); 259 260 struct neigh_seq_state { 261 struct seq_net_private p; 262 struct neigh_table *tbl; 263 struct neigh_hash_table *nht; 264 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 265 struct neighbour *n, loff_t *pos); 266 unsigned int bucket; 267 unsigned int flags; 268 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 269 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 270 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 271 }; 272 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int); 273 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *); 274 extern void neigh_seq_stop(struct seq_file *, void *); 275 276 extern int neigh_sysctl_register(struct net_device *dev, 277 struct neigh_parms *p, 278 char *p_name, 279 proc_handler *proc_handler); 280 extern void neigh_sysctl_unregister(struct neigh_parms *p); 281 282 static inline void __neigh_parms_put(struct neigh_parms *parms) 283 { 284 atomic_dec(&parms->refcnt); 285 } 286 287 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 288 { 289 atomic_inc(&parms->refcnt); 290 return parms; 291 } 292 293 /* 294 * Neighbour references 295 */ 296 297 static inline void neigh_release(struct neighbour *neigh) 298 { 299 if (atomic_dec_and_test(&neigh->refcnt)) 300 neigh_destroy(neigh); 301 } 302 303 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 304 { 305 if (neigh) 306 atomic_inc(&neigh->refcnt); 307 return neigh; 308 } 309 310 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 311 312 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 313 { 314 unsigned long now = jiffies; 315 316 if (neigh->used != now) 317 neigh->used = now; 318 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 319 return __neigh_event_send(neigh, skb); 320 return 0; 321 } 322 323 #ifdef CONFIG_BRIDGE_NETFILTER 324 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 325 { 326 unsigned int seq, hh_alen; 327 328 do { 329 seq = read_seqbegin(&hh->hh_lock); 330 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 331 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 332 } while (read_seqretry(&hh->hh_lock, seq)); 333 return 0; 334 } 335 #endif 336 337 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb) 338 { 339 unsigned int seq; 340 int hh_len; 341 342 do { 343 int hh_alen; 344 345 seq = read_seqbegin(&hh->hh_lock); 346 hh_len = hh->hh_len; 347 hh_alen = HH_DATA_ALIGN(hh_len); 348 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 349 } while (read_seqretry(&hh->hh_lock, seq)); 350 351 skb_push(skb, hh_len); 352 return dev_queue_xmit(skb); 353 } 354 355 static inline struct neighbour * 356 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 357 { 358 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 359 360 if (n || !creat) 361 return n; 362 363 n = neigh_create(tbl, pkey, dev); 364 return IS_ERR(n) ? NULL : n; 365 } 366 367 static inline struct neighbour * 368 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 369 struct net_device *dev) 370 { 371 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 372 373 if (n) 374 return n; 375 376 return neigh_create(tbl, pkey, dev); 377 } 378 379 struct neighbour_cb { 380 unsigned long sched_next; 381 unsigned int flags; 382 }; 383 384 #define LOCALLY_ENQUEUED 0x1 385 386 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 387 388 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 389 const struct net_device *dev) 390 { 391 unsigned int seq; 392 393 do { 394 seq = read_seqbegin(&n->ha_lock); 395 memcpy(dst, n->ha, dev->addr_len); 396 } while (read_seqretry(&n->ha_lock, seq)); 397 } 398 #endif 399