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 #include <linux/bitmap.h> 25 26 #include <linux/err.h> 27 #include <linux/sysctl.h> 28 #include <linux/workqueue.h> 29 #include <net/rtnetlink.h> 30 31 /* 32 * NUD stands for "neighbor unreachability detection" 33 */ 34 35 #define NUD_IN_TIMER (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE) 36 #define NUD_VALID (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY) 37 #define NUD_CONNECTED (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE) 38 39 struct neighbour; 40 41 enum { 42 NEIGH_VAR_MCAST_PROBES, 43 NEIGH_VAR_UCAST_PROBES, 44 NEIGH_VAR_APP_PROBES, 45 NEIGH_VAR_RETRANS_TIME, 46 NEIGH_VAR_BASE_REACHABLE_TIME, 47 NEIGH_VAR_DELAY_PROBE_TIME, 48 NEIGH_VAR_GC_STALETIME, 49 NEIGH_VAR_QUEUE_LEN_BYTES, 50 NEIGH_VAR_PROXY_QLEN, 51 NEIGH_VAR_ANYCAST_DELAY, 52 NEIGH_VAR_PROXY_DELAY, 53 NEIGH_VAR_LOCKTIME, 54 #define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1) 55 /* Following are used as a second way to access one of the above */ 56 NEIGH_VAR_QUEUE_LEN, /* same data as NEIGH_VAR_QUEUE_LEN_BYTES */ 57 NEIGH_VAR_RETRANS_TIME_MS, /* same data as NEIGH_VAR_RETRANS_TIME */ 58 NEIGH_VAR_BASE_REACHABLE_TIME_MS, /* same data as NEIGH_VAR_BASE_REACHABLE_TIME */ 59 /* Following are used by "default" only */ 60 NEIGH_VAR_GC_INTERVAL, 61 NEIGH_VAR_GC_THRESH1, 62 NEIGH_VAR_GC_THRESH2, 63 NEIGH_VAR_GC_THRESH3, 64 NEIGH_VAR_MAX 65 }; 66 67 struct neigh_parms { 68 #ifdef CONFIG_NET_NS 69 struct net *net; 70 #endif 71 struct net_device *dev; 72 struct neigh_parms *next; 73 int (*neigh_setup)(struct neighbour *); 74 void (*neigh_cleanup)(struct neighbour *); 75 struct neigh_table *tbl; 76 77 void *sysctl_table; 78 79 int dead; 80 atomic_t refcnt; 81 struct rcu_head rcu_head; 82 83 int reachable_time; 84 int data[NEIGH_VAR_DATA_MAX]; 85 DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX); 86 }; 87 88 static inline void neigh_var_set(struct neigh_parms *p, int index, int val) 89 { 90 set_bit(index, p->data_state); 91 p->data[index] = val; 92 } 93 94 #define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr]) 95 #define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val) 96 97 static inline void neigh_parms_data_state_setall(struct neigh_parms *p) 98 { 99 bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX); 100 } 101 102 static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p) 103 { 104 bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX); 105 } 106 107 struct neigh_statistics { 108 unsigned long allocs; /* number of allocated neighs */ 109 unsigned long destroys; /* number of destroyed neighs */ 110 unsigned long hash_grows; /* number of hash resizes */ 111 112 unsigned long res_failed; /* number of failed resolutions */ 113 114 unsigned long lookups; /* number of lookups */ 115 unsigned long hits; /* number of hits (among lookups) */ 116 117 unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */ 118 unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */ 119 120 unsigned long periodic_gc_runs; /* number of periodic GC runs */ 121 unsigned long forced_gc_runs; /* number of forced GC runs */ 122 123 unsigned long unres_discards; /* number of unresolved drops */ 124 }; 125 126 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field) 127 128 struct neighbour { 129 struct neighbour __rcu *next; 130 struct neigh_table *tbl; 131 struct neigh_parms *parms; 132 unsigned long confirmed; 133 unsigned long updated; 134 rwlock_t lock; 135 atomic_t refcnt; 136 struct sk_buff_head arp_queue; 137 unsigned int arp_queue_len_bytes; 138 struct timer_list timer; 139 unsigned long used; 140 atomic_t probes; 141 __u8 flags; 142 __u8 nud_state; 143 __u8 type; 144 __u8 dead; 145 seqlock_t ha_lock; 146 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))]; 147 struct hh_cache hh; 148 int (*output)(struct neighbour *, struct sk_buff *); 149 const struct neigh_ops *ops; 150 struct rcu_head rcu; 151 struct net_device *dev; 152 u8 primary_key[0]; 153 }; 154 155 struct neigh_ops { 156 int family; 157 void (*solicit)(struct neighbour *, struct sk_buff *); 158 void (*error_report)(struct neighbour *, struct sk_buff *); 159 int (*output)(struct neighbour *, struct sk_buff *); 160 int (*connected_output)(struct neighbour *, struct sk_buff *); 161 }; 162 163 struct pneigh_entry { 164 struct pneigh_entry *next; 165 #ifdef CONFIG_NET_NS 166 struct net *net; 167 #endif 168 struct net_device *dev; 169 u8 flags; 170 u8 key[0]; 171 }; 172 173 /* 174 * neighbour table manipulation 175 */ 176 177 #define NEIGH_NUM_HASH_RND 4 178 179 struct neigh_hash_table { 180 struct neighbour __rcu **hash_buckets; 181 unsigned int hash_shift; 182 __u32 hash_rnd[NEIGH_NUM_HASH_RND]; 183 struct rcu_head rcu; 184 }; 185 186 187 struct neigh_table { 188 struct neigh_table *next; 189 int family; 190 int entry_size; 191 int key_len; 192 __u32 (*hash)(const void *pkey, 193 const struct net_device *dev, 194 __u32 *hash_rnd); 195 int (*constructor)(struct neighbour *); 196 int (*pconstructor)(struct pneigh_entry *); 197 void (*pdestructor)(struct pneigh_entry *); 198 void (*proxy_redo)(struct sk_buff *skb); 199 char *id; 200 struct neigh_parms parms; 201 /* HACK. gc_* should follow parms without a gap! */ 202 int gc_interval; 203 int gc_thresh1; 204 int gc_thresh2; 205 int gc_thresh3; 206 unsigned long last_flush; 207 struct delayed_work gc_work; 208 struct timer_list proxy_timer; 209 struct sk_buff_head proxy_queue; 210 atomic_t entries; 211 rwlock_t lock; 212 unsigned long last_rand; 213 struct neigh_statistics __percpu *stats; 214 struct neigh_hash_table __rcu *nht; 215 struct pneigh_entry **phash_buckets; 216 }; 217 218 static inline int neigh_parms_family(struct neigh_parms *p) 219 { 220 return p->tbl->family; 221 } 222 223 #define NEIGH_PRIV_ALIGN sizeof(long long) 224 #define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN) 225 226 static inline void *neighbour_priv(const struct neighbour *n) 227 { 228 return (char *)n + n->tbl->entry_size; 229 } 230 231 /* flags for neigh_update() */ 232 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 233 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 234 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 235 #define NEIGH_UPDATE_F_ISROUTER 0x40000000 236 #define NEIGH_UPDATE_F_ADMIN 0x80000000 237 238 void neigh_table_init(struct neigh_table *tbl); 239 int neigh_table_clear(struct neigh_table *tbl); 240 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, 241 struct net_device *dev); 242 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net, 243 const void *pkey); 244 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey, 245 struct net_device *dev, bool want_ref); 246 static inline struct neighbour *neigh_create(struct neigh_table *tbl, 247 const void *pkey, 248 struct net_device *dev) 249 { 250 return __neigh_create(tbl, pkey, dev, true); 251 } 252 void neigh_destroy(struct neighbour *neigh); 253 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 254 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags); 255 void __neigh_set_probe_once(struct neighbour *neigh); 256 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 257 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 258 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 259 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 260 int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb); 261 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 262 struct neighbour *neigh_event_ns(struct neigh_table *tbl, 263 u8 *lladdr, void *saddr, 264 struct net_device *dev); 265 266 struct neigh_parms *neigh_parms_alloc(struct net_device *dev, 267 struct neigh_table *tbl); 268 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 269 270 static inline 271 struct net *neigh_parms_net(const struct neigh_parms *parms) 272 { 273 return read_pnet(&parms->net); 274 } 275 276 unsigned long neigh_rand_reach_time(unsigned long base); 277 278 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 279 struct sk_buff *skb); 280 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, 281 const void *key, struct net_device *dev, 282 int creat); 283 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, 284 const void *key, struct net_device *dev); 285 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, 286 struct net_device *dev); 287 288 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh) 289 { 290 return read_pnet(&pneigh->net); 291 } 292 293 void neigh_app_ns(struct neighbour *n); 294 void neigh_for_each(struct neigh_table *tbl, 295 void (*cb)(struct neighbour *, void *), void *cookie); 296 void __neigh_for_each_release(struct neigh_table *tbl, 297 int (*cb)(struct neighbour *)); 298 void pneigh_for_each(struct neigh_table *tbl, 299 void (*cb)(struct pneigh_entry *)); 300 301 struct neigh_seq_state { 302 struct seq_net_private p; 303 struct neigh_table *tbl; 304 struct neigh_hash_table *nht; 305 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 306 struct neighbour *n, loff_t *pos); 307 unsigned int bucket; 308 unsigned int flags; 309 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 310 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 311 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 312 }; 313 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, 314 unsigned int); 315 void *neigh_seq_next(struct seq_file *, void *, loff_t *); 316 void neigh_seq_stop(struct seq_file *, void *); 317 318 int neigh_proc_dointvec(struct ctl_table *ctl, int write, 319 void __user *buffer, size_t *lenp, loff_t *ppos); 320 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, 321 void __user *buffer, 322 size_t *lenp, loff_t *ppos); 323 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write, 324 void __user *buffer, 325 size_t *lenp, loff_t *ppos); 326 327 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, 328 proc_handler *proc_handler); 329 void neigh_sysctl_unregister(struct neigh_parms *p); 330 331 static inline void __neigh_parms_put(struct neigh_parms *parms) 332 { 333 atomic_dec(&parms->refcnt); 334 } 335 336 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 337 { 338 atomic_inc(&parms->refcnt); 339 return parms; 340 } 341 342 /* 343 * Neighbour references 344 */ 345 346 static inline void neigh_release(struct neighbour *neigh) 347 { 348 if (atomic_dec_and_test(&neigh->refcnt)) 349 neigh_destroy(neigh); 350 } 351 352 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 353 { 354 if (neigh) 355 atomic_inc(&neigh->refcnt); 356 return neigh; 357 } 358 359 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 360 361 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 362 { 363 unsigned long now = jiffies; 364 365 if (neigh->used != now) 366 neigh->used = now; 367 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 368 return __neigh_event_send(neigh, skb); 369 return 0; 370 } 371 372 #ifdef CONFIG_BRIDGE_NETFILTER 373 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 374 { 375 unsigned int seq, hh_alen; 376 377 do { 378 seq = read_seqbegin(&hh->hh_lock); 379 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 380 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 381 } while (read_seqretry(&hh->hh_lock, seq)); 382 return 0; 383 } 384 #endif 385 386 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) 387 { 388 unsigned int seq; 389 int hh_len; 390 391 do { 392 seq = read_seqbegin(&hh->hh_lock); 393 hh_len = hh->hh_len; 394 if (likely(hh_len <= HH_DATA_MOD)) { 395 /* this is inlined by gcc */ 396 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD); 397 } else { 398 int hh_alen = HH_DATA_ALIGN(hh_len); 399 400 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 401 } 402 } while (read_seqretry(&hh->hh_lock, seq)); 403 404 skb_push(skb, hh_len); 405 return dev_queue_xmit(skb); 406 } 407 408 static inline struct neighbour * 409 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 410 { 411 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 412 413 if (n || !creat) 414 return n; 415 416 n = neigh_create(tbl, pkey, dev); 417 return IS_ERR(n) ? NULL : n; 418 } 419 420 static inline struct neighbour * 421 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 422 struct net_device *dev) 423 { 424 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 425 426 if (n) 427 return n; 428 429 return neigh_create(tbl, pkey, dev); 430 } 431 432 struct neighbour_cb { 433 unsigned long sched_next; 434 unsigned int flags; 435 }; 436 437 #define LOCALLY_ENQUEUED 0x1 438 439 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 440 441 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 442 const struct net_device *dev) 443 { 444 unsigned int seq; 445 446 do { 447 seq = read_seqbegin(&n->ha_lock); 448 memcpy(dst, n->ha, dev->addr_len); 449 } while (read_seqretry(&n->ha_lock, seq)); 450 } 451 #endif 452