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 <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; 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 struct timer_list timer; 103 unsigned long used; 104 atomic_t probes; 105 __u8 flags; 106 __u8 nud_state; 107 __u8 type; 108 __u8 dead; 109 seqlock_t ha_lock; 110 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))]; 111 struct hh_cache hh; 112 int (*output)(struct neighbour *, struct sk_buff *); 113 const struct neigh_ops *ops; 114 struct rcu_head rcu; 115 struct net_device *dev; 116 u8 primary_key[0]; 117 }; 118 119 struct neigh_ops { 120 int family; 121 void (*solicit)(struct neighbour *, struct sk_buff *); 122 void (*error_report)(struct neighbour *, struct sk_buff *); 123 int (*output)(struct neighbour *, struct sk_buff *); 124 int (*connected_output)(struct neighbour *, struct sk_buff *); 125 }; 126 127 struct pneigh_entry { 128 struct pneigh_entry *next; 129 #ifdef CONFIG_NET_NS 130 struct net *net; 131 #endif 132 struct net_device *dev; 133 u8 flags; 134 u8 key[0]; 135 }; 136 137 /* 138 * neighbour table manipulation 139 */ 140 141 struct neigh_hash_table { 142 struct neighbour __rcu **hash_buckets; 143 unsigned int hash_shift; 144 __u32 hash_rnd; 145 struct rcu_head rcu; 146 }; 147 148 149 struct neigh_table { 150 struct neigh_table *next; 151 int family; 152 int entry_size; 153 int key_len; 154 __u32 (*hash)(const void *pkey, 155 const struct net_device *dev, 156 __u32 hash_rnd); 157 int (*constructor)(struct neighbour *); 158 int (*pconstructor)(struct pneigh_entry *); 159 void (*pdestructor)(struct pneigh_entry *); 160 void (*proxy_redo)(struct sk_buff *skb); 161 char *id; 162 struct neigh_parms parms; 163 /* HACK. gc_* should follow parms without a gap! */ 164 int gc_interval; 165 int gc_thresh1; 166 int gc_thresh2; 167 int gc_thresh3; 168 unsigned long last_flush; 169 struct delayed_work gc_work; 170 struct timer_list proxy_timer; 171 struct sk_buff_head proxy_queue; 172 atomic_t entries; 173 rwlock_t lock; 174 unsigned long last_rand; 175 struct kmem_cache *kmem_cachep; 176 struct neigh_statistics __percpu *stats; 177 struct neigh_hash_table __rcu *nht; 178 struct pneigh_entry **phash_buckets; 179 }; 180 181 /* flags for neigh_update() */ 182 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 183 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 184 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 185 #define NEIGH_UPDATE_F_ISROUTER 0x40000000 186 #define NEIGH_UPDATE_F_ADMIN 0x80000000 187 188 extern void neigh_table_init(struct neigh_table *tbl); 189 extern void neigh_table_init_no_netlink(struct neigh_table *tbl); 190 extern int neigh_table_clear(struct neigh_table *tbl); 191 extern struct neighbour * neigh_lookup(struct neigh_table *tbl, 192 const void *pkey, 193 struct net_device *dev); 194 extern struct neighbour * neigh_lookup_nodev(struct neigh_table *tbl, 195 struct net *net, 196 const void *pkey); 197 extern struct neighbour * neigh_create(struct neigh_table *tbl, 198 const void *pkey, 199 struct net_device *dev); 200 extern void neigh_destroy(struct neighbour *neigh); 201 extern int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 202 extern int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 203 u32 flags); 204 extern void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 205 extern int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 206 extern int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 207 extern int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 208 extern int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb); 209 extern int neigh_direct_output(struct neighbour *neigh, 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); 216 217 static inline 218 struct net *neigh_parms_net(const struct neigh_parms *parms) 219 { 220 return read_pnet(&parms->net); 221 } 222 223 extern unsigned long neigh_rand_reach_time(unsigned long base); 224 225 extern void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 226 struct sk_buff *skb); 227 extern struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat); 228 extern struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, 229 struct net *net, 230 const void *key, 231 struct net_device *dev); 232 extern int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); 233 234 static inline 235 struct net *pneigh_net(const struct pneigh_entry *pneigh) 236 { 237 return read_pnet(&pneigh->net); 238 } 239 240 extern void neigh_app_ns(struct neighbour *n); 241 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie); 242 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *)); 243 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *)); 244 245 struct neigh_seq_state { 246 struct seq_net_private p; 247 struct neigh_table *tbl; 248 struct neigh_hash_table *nht; 249 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 250 struct neighbour *n, loff_t *pos); 251 unsigned int bucket; 252 unsigned int flags; 253 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 254 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 255 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 256 }; 257 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int); 258 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *); 259 extern void neigh_seq_stop(struct seq_file *, void *); 260 261 extern int neigh_sysctl_register(struct net_device *dev, 262 struct neigh_parms *p, 263 char *p_name, 264 proc_handler *proc_handler); 265 extern void neigh_sysctl_unregister(struct neigh_parms *p); 266 267 static inline void __neigh_parms_put(struct neigh_parms *parms) 268 { 269 atomic_dec(&parms->refcnt); 270 } 271 272 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 273 { 274 atomic_inc(&parms->refcnt); 275 return parms; 276 } 277 278 /* 279 * Neighbour references 280 */ 281 282 static inline void neigh_release(struct neighbour *neigh) 283 { 284 if (atomic_dec_and_test(&neigh->refcnt)) 285 neigh_destroy(neigh); 286 } 287 288 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 289 { 290 if (neigh) 291 atomic_inc(&neigh->refcnt); 292 return neigh; 293 } 294 295 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 296 297 static inline void neigh_confirm(struct neighbour *neigh) 298 { 299 if (neigh) 300 neigh->confirmed = jiffies; 301 } 302 303 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 304 { 305 unsigned long now = jiffies; 306 307 if (neigh->used != now) 308 neigh->used = now; 309 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 310 return __neigh_event_send(neigh, skb); 311 return 0; 312 } 313 314 #ifdef CONFIG_BRIDGE_NETFILTER 315 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 316 { 317 unsigned seq, hh_alen; 318 319 do { 320 seq = read_seqbegin(&hh->hh_lock); 321 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 322 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 323 } while (read_seqretry(&hh->hh_lock, seq)); 324 return 0; 325 } 326 #endif 327 328 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb) 329 { 330 unsigned seq; 331 int hh_len; 332 333 do { 334 int hh_alen; 335 336 seq = read_seqbegin(&hh->hh_lock); 337 hh_len = hh->hh_len; 338 hh_alen = HH_DATA_ALIGN(hh_len); 339 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 340 } while (read_seqretry(&hh->hh_lock, seq)); 341 342 skb_push(skb, hh_len); 343 return dev_queue_xmit(skb); 344 } 345 346 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb) 347 { 348 struct hh_cache *hh = &n->hh; 349 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len) 350 return neigh_hh_output(hh, skb); 351 else 352 return n->output(n, 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