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 extern void neigh_table_init(struct neigh_table *tbl); 199 extern int neigh_table_clear(struct neigh_table *tbl); 200 extern struct neighbour * neigh_lookup(struct neigh_table *tbl, 201 const void *pkey, 202 struct net_device *dev); 203 extern struct neighbour * neigh_lookup_nodev(struct neigh_table *tbl, 204 struct net *net, 205 const void *pkey); 206 extern struct neighbour * __neigh_create(struct neigh_table *tbl, 207 const void *pkey, 208 struct net_device *dev, 209 bool want_ref); 210 static inline struct neighbour *neigh_create(struct neigh_table *tbl, 211 const void *pkey, 212 struct net_device *dev) 213 { 214 return __neigh_create(tbl, pkey, dev, true); 215 } 216 extern void neigh_destroy(struct neighbour *neigh); 217 extern int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 218 extern int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 219 u32 flags); 220 extern void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 221 extern int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 222 extern int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 223 extern int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 224 extern int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb); 225 extern int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 226 extern struct neighbour *neigh_event_ns(struct neigh_table *tbl, 227 u8 *lladdr, void *saddr, 228 struct net_device *dev); 229 230 extern struct neigh_parms *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl); 231 extern void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 232 233 static inline 234 struct net *neigh_parms_net(const struct neigh_parms *parms) 235 { 236 return read_pnet(&parms->net); 237 } 238 239 extern unsigned long neigh_rand_reach_time(unsigned long base); 240 241 extern void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 242 struct sk_buff *skb); 243 extern struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat); 244 extern struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, 245 struct net *net, 246 const void *key, 247 struct net_device *dev); 248 extern int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); 249 250 static inline 251 struct net *pneigh_net(const struct pneigh_entry *pneigh) 252 { 253 return read_pnet(&pneigh->net); 254 } 255 256 extern void neigh_app_ns(struct neighbour *n); 257 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie); 258 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *)); 259 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *)); 260 261 struct neigh_seq_state { 262 struct seq_net_private p; 263 struct neigh_table *tbl; 264 struct neigh_hash_table *nht; 265 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 266 struct neighbour *n, loff_t *pos); 267 unsigned int bucket; 268 unsigned int flags; 269 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 270 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 271 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 272 }; 273 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int); 274 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *); 275 extern void neigh_seq_stop(struct seq_file *, void *); 276 277 extern int neigh_sysctl_register(struct net_device *dev, 278 struct neigh_parms *p, 279 char *p_name, 280 proc_handler *proc_handler); 281 extern void neigh_sysctl_unregister(struct neigh_parms *p); 282 283 static inline void __neigh_parms_put(struct neigh_parms *parms) 284 { 285 atomic_dec(&parms->refcnt); 286 } 287 288 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 289 { 290 atomic_inc(&parms->refcnt); 291 return parms; 292 } 293 294 /* 295 * Neighbour references 296 */ 297 298 static inline void neigh_release(struct neighbour *neigh) 299 { 300 if (atomic_dec_and_test(&neigh->refcnt)) 301 neigh_destroy(neigh); 302 } 303 304 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 305 { 306 if (neigh) 307 atomic_inc(&neigh->refcnt); 308 return neigh; 309 } 310 311 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 312 313 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 314 { 315 unsigned long now = jiffies; 316 317 if (neigh->used != now) 318 neigh->used = now; 319 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 320 return __neigh_event_send(neigh, skb); 321 return 0; 322 } 323 324 #ifdef CONFIG_BRIDGE_NETFILTER 325 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 326 { 327 unsigned int seq, hh_alen; 328 329 do { 330 seq = read_seqbegin(&hh->hh_lock); 331 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 332 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 333 } while (read_seqretry(&hh->hh_lock, seq)); 334 return 0; 335 } 336 #endif 337 338 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) 339 { 340 unsigned int seq; 341 int hh_len; 342 343 do { 344 seq = read_seqbegin(&hh->hh_lock); 345 hh_len = hh->hh_len; 346 if (likely(hh_len <= HH_DATA_MOD)) { 347 /* this is inlined by gcc */ 348 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD); 349 } else { 350 int hh_alen = HH_DATA_ALIGN(hh_len); 351 352 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 353 } 354 } while (read_seqretry(&hh->hh_lock, seq)); 355 356 skb_push(skb, hh_len); 357 return dev_queue_xmit(skb); 358 } 359 360 static inline struct neighbour * 361 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 362 { 363 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 364 365 if (n || !creat) 366 return n; 367 368 n = neigh_create(tbl, pkey, dev); 369 return IS_ERR(n) ? NULL : n; 370 } 371 372 static inline struct neighbour * 373 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 374 struct net_device *dev) 375 { 376 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 377 378 if (n) 379 return n; 380 381 return neigh_create(tbl, pkey, dev); 382 } 383 384 struct neighbour_cb { 385 unsigned long sched_next; 386 unsigned int flags; 387 }; 388 389 #define LOCALLY_ENQUEUED 0x1 390 391 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 392 393 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 394 const struct net_device *dev) 395 { 396 unsigned int seq; 397 398 do { 399 seq = read_seqbegin(&n->ha_lock); 400 memcpy(dst, n->ha, dev->addr_len); 401 } while (read_seqretry(&n->ha_lock, seq)); 402 } 403 #endif 404