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 struct neigh_hash_table { 143 struct neighbour __rcu **hash_buckets; 144 unsigned int hash_shift; 145 __u32 hash_rnd; 146 struct rcu_head rcu; 147 }; 148 149 150 struct neigh_table { 151 struct neigh_table *next; 152 int family; 153 int entry_size; 154 int key_len; 155 __u32 (*hash)(const void *pkey, 156 const struct net_device *dev, 157 __u32 hash_rnd); 158 int (*constructor)(struct neighbour *); 159 int (*pconstructor)(struct pneigh_entry *); 160 void (*pdestructor)(struct pneigh_entry *); 161 void (*proxy_redo)(struct sk_buff *skb); 162 char *id; 163 struct neigh_parms parms; 164 /* HACK. gc_* should follow parms without a gap! */ 165 int gc_interval; 166 int gc_thresh1; 167 int gc_thresh2; 168 int gc_thresh3; 169 unsigned long last_flush; 170 struct delayed_work gc_work; 171 struct timer_list proxy_timer; 172 struct sk_buff_head proxy_queue; 173 atomic_t entries; 174 rwlock_t lock; 175 unsigned long last_rand; 176 struct neigh_statistics __percpu *stats; 177 struct neigh_hash_table __rcu *nht; 178 struct pneigh_entry **phash_buckets; 179 }; 180 181 #define NEIGH_PRIV_ALIGN sizeof(long long) 182 183 static inline void *neighbour_priv(const struct neighbour *n) 184 { 185 return (char *)n + ALIGN(sizeof(*n) + n->tbl->key_len, NEIGH_PRIV_ALIGN); 186 } 187 188 /* flags for neigh_update() */ 189 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 190 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 191 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 192 #define NEIGH_UPDATE_F_ISROUTER 0x40000000 193 #define NEIGH_UPDATE_F_ADMIN 0x80000000 194 195 extern void neigh_table_init(struct neigh_table *tbl); 196 extern void neigh_table_init_no_netlink(struct neigh_table *tbl); 197 extern int neigh_table_clear(struct neigh_table *tbl); 198 extern struct neighbour * neigh_lookup(struct neigh_table *tbl, 199 const void *pkey, 200 struct net_device *dev); 201 extern struct neighbour * neigh_lookup_nodev(struct neigh_table *tbl, 202 struct net *net, 203 const void *pkey); 204 extern struct neighbour * neigh_create(struct neigh_table *tbl, 205 const void *pkey, 206 struct net_device *dev); 207 extern void neigh_destroy(struct neighbour *neigh); 208 extern int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 209 extern int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 210 u32 flags); 211 extern void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 212 extern int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 213 extern int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 214 extern int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 215 extern int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb); 216 extern int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 217 extern struct neighbour *neigh_event_ns(struct neigh_table *tbl, 218 u8 *lladdr, void *saddr, 219 struct net_device *dev); 220 221 extern struct neigh_parms *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl); 222 extern void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 223 224 static inline 225 struct net *neigh_parms_net(const struct neigh_parms *parms) 226 { 227 return read_pnet(&parms->net); 228 } 229 230 extern unsigned long neigh_rand_reach_time(unsigned long base); 231 232 extern void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 233 struct sk_buff *skb); 234 extern struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat); 235 extern struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, 236 struct net *net, 237 const void *key, 238 struct net_device *dev); 239 extern int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); 240 241 static inline 242 struct net *pneigh_net(const struct pneigh_entry *pneigh) 243 { 244 return read_pnet(&pneigh->net); 245 } 246 247 extern void neigh_app_ns(struct neighbour *n); 248 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie); 249 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *)); 250 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *)); 251 252 struct neigh_seq_state { 253 struct seq_net_private p; 254 struct neigh_table *tbl; 255 struct neigh_hash_table *nht; 256 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 257 struct neighbour *n, loff_t *pos); 258 unsigned int bucket; 259 unsigned int flags; 260 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 261 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 262 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 263 }; 264 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int); 265 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *); 266 extern void neigh_seq_stop(struct seq_file *, void *); 267 268 extern int neigh_sysctl_register(struct net_device *dev, 269 struct neigh_parms *p, 270 char *p_name, 271 proc_handler *proc_handler); 272 extern void neigh_sysctl_unregister(struct neigh_parms *p); 273 274 static inline void __neigh_parms_put(struct neigh_parms *parms) 275 { 276 atomic_dec(&parms->refcnt); 277 } 278 279 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 280 { 281 atomic_inc(&parms->refcnt); 282 return parms; 283 } 284 285 /* 286 * Neighbour references 287 */ 288 289 static inline void neigh_release(struct neighbour *neigh) 290 { 291 if (atomic_dec_and_test(&neigh->refcnt)) 292 neigh_destroy(neigh); 293 } 294 295 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 296 { 297 if (neigh) 298 atomic_inc(&neigh->refcnt); 299 return neigh; 300 } 301 302 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 303 304 static inline void neigh_confirm(struct neighbour *neigh) 305 { 306 if (neigh) 307 neigh->confirmed = jiffies; 308 } 309 310 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 311 { 312 unsigned long now = jiffies; 313 314 if (neigh->used != now) 315 neigh->used = now; 316 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 317 return __neigh_event_send(neigh, skb); 318 return 0; 319 } 320 321 #ifdef CONFIG_BRIDGE_NETFILTER 322 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 323 { 324 unsigned seq, hh_alen; 325 326 do { 327 seq = read_seqbegin(&hh->hh_lock); 328 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 329 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 330 } while (read_seqretry(&hh->hh_lock, seq)); 331 return 0; 332 } 333 #endif 334 335 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb) 336 { 337 unsigned seq; 338 int hh_len; 339 340 do { 341 int hh_alen; 342 343 seq = read_seqbegin(&hh->hh_lock); 344 hh_len = hh->hh_len; 345 hh_alen = HH_DATA_ALIGN(hh_len); 346 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 347 } while (read_seqretry(&hh->hh_lock, seq)); 348 349 skb_push(skb, hh_len); 350 return dev_queue_xmit(skb); 351 } 352 353 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb) 354 { 355 struct hh_cache *hh = &n->hh; 356 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len) 357 return neigh_hh_output(hh, skb); 358 else 359 return n->output(n, skb); 360 } 361 362 static inline struct neighbour * 363 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 364 { 365 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 366 367 if (n || !creat) 368 return n; 369 370 n = neigh_create(tbl, pkey, dev); 371 return IS_ERR(n) ? NULL : n; 372 } 373 374 static inline struct neighbour * 375 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 376 struct net_device *dev) 377 { 378 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 379 380 if (n) 381 return n; 382 383 return neigh_create(tbl, pkey, dev); 384 } 385 386 struct neighbour_cb { 387 unsigned long sched_next; 388 unsigned int flags; 389 }; 390 391 #define LOCALLY_ENQUEUED 0x1 392 393 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 394 395 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 396 const struct net_device *dev) 397 { 398 unsigned int seq; 399 400 do { 401 seq = read_seqbegin(&n->ha_lock); 402 memcpy(dst, n->ha, dev->addr_len); 403 } while (read_seqretry(&n->ha_lock, seq)); 404 } 405 #endif 406