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 #define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN) 185 186 static inline void *neighbour_priv(const struct neighbour *n) 187 { 188 return (char *)n + n->tbl->entry_size; 189 } 190 191 /* flags for neigh_update() */ 192 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 193 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 194 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 195 #define NEIGH_UPDATE_F_ISROUTER 0x40000000 196 #define NEIGH_UPDATE_F_ADMIN 0x80000000 197 198 void neigh_table_init(struct neigh_table *tbl); 199 int neigh_table_clear(struct neigh_table *tbl); 200 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, 201 struct net_device *dev); 202 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net, 203 const void *pkey); 204 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey, 205 struct net_device *dev, bool want_ref); 206 static inline struct neighbour *neigh_create(struct neigh_table *tbl, 207 const void *pkey, 208 struct net_device *dev) 209 { 210 return __neigh_create(tbl, pkey, dev, true); 211 } 212 void neigh_destroy(struct neighbour *neigh); 213 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 214 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags); 215 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 216 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 217 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 218 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 219 int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb); 220 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 221 struct neighbour *neigh_event_ns(struct neigh_table *tbl, 222 u8 *lladdr, void *saddr, 223 struct net_device *dev); 224 225 struct neigh_parms *neigh_parms_alloc(struct net_device *dev, 226 struct neigh_table *tbl); 227 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 228 229 static inline 230 struct net *neigh_parms_net(const struct neigh_parms *parms) 231 { 232 return read_pnet(&parms->net); 233 } 234 235 unsigned long neigh_rand_reach_time(unsigned long base); 236 237 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 238 struct sk_buff *skb); 239 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, 240 const void *key, struct net_device *dev, 241 int creat); 242 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, 243 const void *key, struct net_device *dev); 244 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, 245 struct net_device *dev); 246 247 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh) 248 { 249 return read_pnet(&pneigh->net); 250 } 251 252 void neigh_app_ns(struct neighbour *n); 253 void neigh_for_each(struct neigh_table *tbl, 254 void (*cb)(struct neighbour *, void *), void *cookie); 255 void __neigh_for_each_release(struct neigh_table *tbl, 256 int (*cb)(struct neighbour *)); 257 void pneigh_for_each(struct neigh_table *tbl, 258 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 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, 273 unsigned int); 274 void *neigh_seq_next(struct seq_file *, void *, loff_t *); 275 void neigh_seq_stop(struct seq_file *, void *); 276 277 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, 278 char *p_name, proc_handler *proc_handler); 279 void neigh_sysctl_unregister(struct neigh_parms *p); 280 281 static inline void __neigh_parms_put(struct neigh_parms *parms) 282 { 283 atomic_dec(&parms->refcnt); 284 } 285 286 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 287 { 288 atomic_inc(&parms->refcnt); 289 return parms; 290 } 291 292 /* 293 * Neighbour references 294 */ 295 296 static inline void neigh_release(struct neighbour *neigh) 297 { 298 if (atomic_dec_and_test(&neigh->refcnt)) 299 neigh_destroy(neigh); 300 } 301 302 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 303 { 304 if (neigh) 305 atomic_inc(&neigh->refcnt); 306 return neigh; 307 } 308 309 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 310 311 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 312 { 313 unsigned long now = jiffies; 314 315 if (neigh->used != now) 316 neigh->used = now; 317 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 318 return __neigh_event_send(neigh, skb); 319 return 0; 320 } 321 322 #ifdef CONFIG_BRIDGE_NETFILTER 323 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 324 { 325 unsigned int seq, hh_alen; 326 327 do { 328 seq = read_seqbegin(&hh->hh_lock); 329 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 330 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 331 } while (read_seqretry(&hh->hh_lock, seq)); 332 return 0; 333 } 334 #endif 335 336 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) 337 { 338 unsigned int seq; 339 int hh_len; 340 341 do { 342 seq = read_seqbegin(&hh->hh_lock); 343 hh_len = hh->hh_len; 344 if (likely(hh_len <= HH_DATA_MOD)) { 345 /* this is inlined by gcc */ 346 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD); 347 } else { 348 int hh_alen = HH_DATA_ALIGN(hh_len); 349 350 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 351 } 352 } while (read_seqretry(&hh->hh_lock, seq)); 353 354 skb_push(skb, hh_len); 355 return dev_queue_xmit(skb); 356 } 357 358 static inline struct neighbour * 359 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 360 { 361 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 362 363 if (n || !creat) 364 return n; 365 366 n = neigh_create(tbl, pkey, dev); 367 return IS_ERR(n) ? NULL : n; 368 } 369 370 static inline struct neighbour * 371 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 372 struct net_device *dev) 373 { 374 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 375 376 if (n) 377 return n; 378 379 return neigh_create(tbl, pkey, dev); 380 } 381 382 struct neighbour_cb { 383 unsigned long sched_next; 384 unsigned int flags; 385 }; 386 387 #define LOCALLY_ENQUEUED 0x1 388 389 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 390 391 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 392 const struct net_device *dev) 393 { 394 unsigned int seq; 395 396 do { 397 seq = read_seqbegin(&n->ha_lock); 398 memcpy(dst, n->ha, dev->addr_len); 399 } while (read_seqretry(&n->ha_lock, seq)); 400 } 401 #endif 402