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 int (*hh_output)(struct sk_buff*); 126 int (*queue_xmit)(struct sk_buff*); 127 }; 128 129 struct pneigh_entry { 130 struct pneigh_entry *next; 131 #ifdef CONFIG_NET_NS 132 struct net *net; 133 #endif 134 struct net_device *dev; 135 u8 flags; 136 u8 key[0]; 137 }; 138 139 /* 140 * neighbour table manipulation 141 */ 142 143 struct neigh_hash_table { 144 struct neighbour __rcu **hash_buckets; 145 unsigned int hash_mask; 146 __u32 hash_rnd; 147 struct rcu_head rcu; 148 }; 149 150 151 struct neigh_table { 152 struct neigh_table *next; 153 int family; 154 int entry_size; 155 int key_len; 156 __u32 (*hash)(const void *pkey, 157 const struct net_device *dev, 158 __u32 hash_rnd); 159 int (*constructor)(struct neighbour *); 160 int (*pconstructor)(struct pneigh_entry *); 161 void (*pdestructor)(struct pneigh_entry *); 162 void (*proxy_redo)(struct sk_buff *skb); 163 char *id; 164 struct neigh_parms parms; 165 /* HACK. gc_* should follow parms without a gap! */ 166 int gc_interval; 167 int gc_thresh1; 168 int gc_thresh2; 169 int gc_thresh3; 170 unsigned long last_flush; 171 struct delayed_work gc_work; 172 struct timer_list proxy_timer; 173 struct sk_buff_head proxy_queue; 174 atomic_t entries; 175 rwlock_t lock; 176 unsigned long last_rand; 177 struct kmem_cache *kmem_cachep; 178 struct neigh_statistics __percpu *stats; 179 struct neigh_hash_table __rcu *nht; 180 struct pneigh_entry **phash_buckets; 181 }; 182 183 /* flags for neigh_update() */ 184 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 185 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 186 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 187 #define NEIGH_UPDATE_F_ISROUTER 0x40000000 188 #define NEIGH_UPDATE_F_ADMIN 0x80000000 189 190 extern void neigh_table_init(struct neigh_table *tbl); 191 extern void neigh_table_init_no_netlink(struct neigh_table *tbl); 192 extern int neigh_table_clear(struct neigh_table *tbl); 193 extern struct neighbour * neigh_lookup(struct neigh_table *tbl, 194 const void *pkey, 195 struct net_device *dev); 196 extern struct neighbour * neigh_lookup_nodev(struct neigh_table *tbl, 197 struct net *net, 198 const void *pkey); 199 extern struct neighbour * neigh_create(struct neigh_table *tbl, 200 const void *pkey, 201 struct net_device *dev); 202 extern void neigh_destroy(struct neighbour *neigh); 203 extern int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 204 extern int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 205 u32 flags); 206 extern void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 207 extern int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 208 extern int neigh_resolve_output(struct sk_buff *skb); 209 extern int neigh_connected_output(struct sk_buff *skb); 210 extern int neigh_compat_output(struct sk_buff *skb); 211 extern struct neighbour *neigh_event_ns(struct neigh_table *tbl, 212 u8 *lladdr, void *saddr, 213 struct net_device *dev); 214 215 extern struct neigh_parms *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl); 216 extern void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 217 218 static inline 219 struct net *neigh_parms_net(const struct neigh_parms *parms) 220 { 221 return read_pnet(&parms->net); 222 } 223 224 extern unsigned long neigh_rand_reach_time(unsigned long base); 225 226 extern void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 227 struct sk_buff *skb); 228 extern struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat); 229 extern struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, 230 struct net *net, 231 const void *key, 232 struct net_device *dev); 233 extern int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); 234 235 static inline 236 struct net *pneigh_net(const struct pneigh_entry *pneigh) 237 { 238 return read_pnet(&pneigh->net); 239 } 240 241 extern void neigh_app_ns(struct neighbour *n); 242 extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie); 243 extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *)); 244 extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *)); 245 246 struct neigh_seq_state { 247 struct seq_net_private p; 248 struct neigh_table *tbl; 249 struct neigh_hash_table *nht; 250 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 251 struct neighbour *n, loff_t *pos); 252 unsigned int bucket; 253 unsigned int flags; 254 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 255 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 256 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 257 }; 258 extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int); 259 extern void *neigh_seq_next(struct seq_file *, void *, loff_t *); 260 extern void neigh_seq_stop(struct seq_file *, void *); 261 262 extern int neigh_sysctl_register(struct net_device *dev, 263 struct neigh_parms *p, 264 char *p_name, 265 proc_handler *proc_handler); 266 extern void neigh_sysctl_unregister(struct neigh_parms *p); 267 268 static inline void __neigh_parms_put(struct neigh_parms *parms) 269 { 270 atomic_dec(&parms->refcnt); 271 } 272 273 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 274 { 275 atomic_inc(&parms->refcnt); 276 return parms; 277 } 278 279 /* 280 * Neighbour references 281 */ 282 283 static inline void neigh_release(struct neighbour *neigh) 284 { 285 if (atomic_dec_and_test(&neigh->refcnt)) 286 neigh_destroy(neigh); 287 } 288 289 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 290 { 291 if (neigh) 292 atomic_inc(&neigh->refcnt); 293 return neigh; 294 } 295 296 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 297 298 static inline void neigh_confirm(struct neighbour *neigh) 299 { 300 if (neigh) 301 neigh->confirmed = jiffies; 302 } 303 304 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 305 { 306 unsigned long now = ACCESS_ONCE(jiffies); 307 308 if (neigh->used != now) 309 neigh->used = now; 310 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 311 return __neigh_event_send(neigh, skb); 312 return 0; 313 } 314 315 #ifdef CONFIG_BRIDGE_NETFILTER 316 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 317 { 318 unsigned seq, hh_alen; 319 320 do { 321 seq = read_seqbegin(&hh->hh_lock); 322 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 323 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 324 } while (read_seqretry(&hh->hh_lock, seq)); 325 return 0; 326 } 327 #endif 328 329 static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb) 330 { 331 unsigned seq; 332 int hh_len; 333 334 do { 335 int hh_alen; 336 337 seq = read_seqbegin(&hh->hh_lock); 338 hh_len = hh->hh_len; 339 hh_alen = HH_DATA_ALIGN(hh_len); 340 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 341 } while (read_seqretry(&hh->hh_lock, seq)); 342 343 skb_push(skb, hh_len); 344 return hh->hh_output(skb); 345 } 346 347 static inline struct neighbour * 348 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 349 { 350 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 351 352 if (n || !creat) 353 return n; 354 355 n = neigh_create(tbl, pkey, dev); 356 return IS_ERR(n) ? NULL : n; 357 } 358 359 static inline struct neighbour * 360 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 361 struct net_device *dev) 362 { 363 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 364 365 if (n) 366 return n; 367 368 return neigh_create(tbl, pkey, dev); 369 } 370 371 struct neighbour_cb { 372 unsigned long sched_next; 373 unsigned int flags; 374 }; 375 376 #define LOCALLY_ENQUEUED 0x1 377 378 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 379 380 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 381 const struct net_device *dev) 382 { 383 unsigned int seq; 384 385 do { 386 seq = read_seqbegin(&n->ha_lock); 387 memcpy(dst, n->ha, dev->addr_len); 388 } while (read_seqretry(&n->ha_lock, seq)); 389 } 390 #endif 391