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 sk_buff *skb); 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 sk_buff*); 124 int (*connected_output)(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 sk_buff *skb); 207 extern int neigh_connected_output(struct sk_buff *skb); 208 extern int neigh_compat_output(struct sk_buff *skb); 209 extern struct neighbour *neigh_event_ns(struct neigh_table *tbl, 210 u8 *lladdr, void *saddr, 211 struct net_device *dev); 212 213 extern struct neigh_parms *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl); 214 extern void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 215 216 static inline 217 struct net *neigh_parms_net(const struct neigh_parms *parms) 218 { 219 return read_pnet(&parms->net); 220 } 221 222 extern unsigned long neigh_rand_reach_time(unsigned long base); 223 224 extern void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 225 struct sk_buff *skb); 226 extern struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat); 227 extern struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, 228 struct net *net, 229 const void *key, 230 struct net_device *dev); 231 extern int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); 232 233 static inline 234 struct net *pneigh_net(const struct pneigh_entry *pneigh) 235 { 236 return read_pnet(&pneigh->net); 237 } 238 239 extern void neigh_app_ns(struct neighbour *n); 240 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie); 241 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *)); 242 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *)); 243 244 struct neigh_seq_state { 245 struct seq_net_private p; 246 struct neigh_table *tbl; 247 struct neigh_hash_table *nht; 248 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 249 struct neighbour *n, loff_t *pos); 250 unsigned int bucket; 251 unsigned int flags; 252 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 253 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 254 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 255 }; 256 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int); 257 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *); 258 extern void neigh_seq_stop(struct seq_file *, void *); 259 260 extern int neigh_sysctl_register(struct net_device *dev, 261 struct neigh_parms *p, 262 char *p_name, 263 proc_handler *proc_handler); 264 extern void neigh_sysctl_unregister(struct neigh_parms *p); 265 266 static inline void __neigh_parms_put(struct neigh_parms *parms) 267 { 268 atomic_dec(&parms->refcnt); 269 } 270 271 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 272 { 273 atomic_inc(&parms->refcnt); 274 return parms; 275 } 276 277 /* 278 * Neighbour references 279 */ 280 281 static inline void neigh_release(struct neighbour *neigh) 282 { 283 if (atomic_dec_and_test(&neigh->refcnt)) 284 neigh_destroy(neigh); 285 } 286 287 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 288 { 289 if (neigh) 290 atomic_inc(&neigh->refcnt); 291 return neigh; 292 } 293 294 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 295 296 static inline void neigh_confirm(struct neighbour *neigh) 297 { 298 if (neigh) 299 neigh->confirmed = jiffies; 300 } 301 302 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 303 { 304 unsigned long now = jiffies; 305 306 if (neigh->used != now) 307 neigh->used = now; 308 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 309 return __neigh_event_send(neigh, skb); 310 return 0; 311 } 312 313 #ifdef CONFIG_BRIDGE_NETFILTER 314 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 315 { 316 unsigned seq, hh_alen; 317 318 do { 319 seq = read_seqbegin(&hh->hh_lock); 320 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 321 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 322 } while (read_seqretry(&hh->hh_lock, seq)); 323 return 0; 324 } 325 #endif 326 327 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb) 328 { 329 unsigned seq; 330 int hh_len; 331 332 do { 333 int hh_alen; 334 335 seq = read_seqbegin(&hh->hh_lock); 336 hh_len = hh->hh_len; 337 hh_alen = HH_DATA_ALIGN(hh_len); 338 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 339 } while (read_seqretry(&hh->hh_lock, seq)); 340 341 skb_push(skb, hh_len); 342 return dev_queue_xmit(skb); 343 } 344 345 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb) 346 { 347 struct hh_cache *hh = &n->hh; 348 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len) 349 return neigh_hh_output(hh, skb); 350 else 351 return n->output(skb); 352 } 353 354 static inline struct neighbour * 355 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 356 { 357 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 358 359 if (n || !creat) 360 return n; 361 362 n = neigh_create(tbl, pkey, dev); 363 return IS_ERR(n) ? NULL : n; 364 } 365 366 static inline struct neighbour * 367 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 368 struct net_device *dev) 369 { 370 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 371 372 if (n) 373 return n; 374 375 return neigh_create(tbl, pkey, dev); 376 } 377 378 struct neighbour_cb { 379 unsigned long sched_next; 380 unsigned int flags; 381 }; 382 383 #define LOCALLY_ENQUEUED 0x1 384 385 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 386 387 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 388 const struct net_device *dev) 389 { 390 unsigned int seq; 391 392 do { 393 seq = read_seqbegin(&n->ha_lock); 394 memcpy(dst, n->ha, dev->addr_len); 395 } while (read_seqretry(&n->ha_lock, seq)); 396 } 397 #endif 398