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 possible_net_t net; 69 struct net_device *dev; 70 struct list_head list; 71 int (*neigh_setup)(struct neighbour *); 72 void (*neigh_cleanup)(struct neighbour *); 73 struct neigh_table *tbl; 74 75 void *sysctl_table; 76 77 int dead; 78 atomic_t refcnt; 79 struct rcu_head rcu_head; 80 81 int reachable_time; 82 int data[NEIGH_VAR_DATA_MAX]; 83 DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX); 84 }; 85 86 static inline void neigh_var_set(struct neigh_parms *p, int index, int val) 87 { 88 set_bit(index, p->data_state); 89 p->data[index] = val; 90 } 91 92 #define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr]) 93 94 /* In ndo_neigh_setup, NEIGH_VAR_INIT should be used. 95 * In other cases, NEIGH_VAR_SET should be used. 96 */ 97 #define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val) 98 #define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val) 99 100 static inline void neigh_parms_data_state_setall(struct neigh_parms *p) 101 { 102 bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX); 103 } 104 105 static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p) 106 { 107 bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX); 108 } 109 110 struct neigh_statistics { 111 unsigned long allocs; /* number of allocated neighs */ 112 unsigned long destroys; /* number of destroyed neighs */ 113 unsigned long hash_grows; /* number of hash resizes */ 114 115 unsigned long res_failed; /* number of failed resolutions */ 116 117 unsigned long lookups; /* number of lookups */ 118 unsigned long hits; /* number of hits (among lookups) */ 119 120 unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */ 121 unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */ 122 123 unsigned long periodic_gc_runs; /* number of periodic GC runs */ 124 unsigned long forced_gc_runs; /* number of forced GC runs */ 125 126 unsigned long unres_discards; /* number of unresolved drops */ 127 }; 128 129 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field) 130 131 struct neighbour { 132 struct neighbour __rcu *next; 133 struct neigh_table *tbl; 134 struct neigh_parms *parms; 135 unsigned long confirmed; 136 unsigned long updated; 137 rwlock_t lock; 138 atomic_t refcnt; 139 struct sk_buff_head arp_queue; 140 unsigned int arp_queue_len_bytes; 141 struct timer_list timer; 142 unsigned long used; 143 atomic_t probes; 144 __u8 flags; 145 __u8 nud_state; 146 __u8 type; 147 __u8 dead; 148 seqlock_t ha_lock; 149 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))]; 150 struct hh_cache hh; 151 int (*output)(struct neighbour *, struct sk_buff *); 152 const struct neigh_ops *ops; 153 struct rcu_head rcu; 154 struct net_device *dev; 155 u8 primary_key[0]; 156 }; 157 158 struct neigh_ops { 159 int family; 160 void (*solicit)(struct neighbour *, struct sk_buff *); 161 void (*error_report)(struct neighbour *, struct sk_buff *); 162 int (*output)(struct neighbour *, struct sk_buff *); 163 int (*connected_output)(struct neighbour *, struct sk_buff *); 164 }; 165 166 struct pneigh_entry { 167 struct pneigh_entry *next; 168 possible_net_t net; 169 struct net_device *dev; 170 u8 flags; 171 u8 key[0]; 172 }; 173 174 /* 175 * neighbour table manipulation 176 */ 177 178 #define NEIGH_NUM_HASH_RND 4 179 180 struct neigh_hash_table { 181 struct neighbour __rcu **hash_buckets; 182 unsigned int hash_shift; 183 __u32 hash_rnd[NEIGH_NUM_HASH_RND]; 184 struct rcu_head rcu; 185 }; 186 187 188 struct neigh_table { 189 int family; 190 int entry_size; 191 int key_len; 192 __be16 protocol; 193 __u32 (*hash)(const void *pkey, 194 const struct net_device *dev, 195 __u32 *hash_rnd); 196 bool (*key_eq)(const struct neighbour *, const void *pkey); 197 int (*constructor)(struct neighbour *); 198 int (*pconstructor)(struct pneigh_entry *); 199 void (*pdestructor)(struct pneigh_entry *); 200 void (*proxy_redo)(struct sk_buff *skb); 201 char *id; 202 struct neigh_parms parms; 203 struct list_head parms_list; 204 int gc_interval; 205 int gc_thresh1; 206 int gc_thresh2; 207 int gc_thresh3; 208 unsigned long last_flush; 209 struct delayed_work gc_work; 210 struct timer_list proxy_timer; 211 struct sk_buff_head proxy_queue; 212 atomic_t entries; 213 rwlock_t lock; 214 unsigned long last_rand; 215 struct neigh_statistics __percpu *stats; 216 struct neigh_hash_table __rcu *nht; 217 struct pneigh_entry **phash_buckets; 218 }; 219 220 enum { 221 NEIGH_ARP_TABLE = 0, 222 NEIGH_ND_TABLE = 1, 223 NEIGH_DN_TABLE = 2, 224 NEIGH_NR_TABLES, 225 NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */ 226 }; 227 228 static inline int neigh_parms_family(struct neigh_parms *p) 229 { 230 return p->tbl->family; 231 } 232 233 #define NEIGH_PRIV_ALIGN sizeof(long long) 234 #define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN) 235 236 static inline void *neighbour_priv(const struct neighbour *n) 237 { 238 return (char *)n + n->tbl->entry_size; 239 } 240 241 /* flags for neigh_update() */ 242 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 243 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 244 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 245 #define NEIGH_UPDATE_F_ISROUTER 0x40000000 246 #define NEIGH_UPDATE_F_ADMIN 0x80000000 247 248 249 static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey) 250 { 251 return *(const u16 *)n->primary_key == *(const u16 *)pkey; 252 } 253 254 static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey) 255 { 256 return *(const u32 *)n->primary_key == *(const u32 *)pkey; 257 } 258 259 static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey) 260 { 261 const u32 *n32 = (const u32 *)n->primary_key; 262 const u32 *p32 = pkey; 263 264 return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) | 265 (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0; 266 } 267 268 static inline struct neighbour *___neigh_lookup_noref( 269 struct neigh_table *tbl, 270 bool (*key_eq)(const struct neighbour *n, const void *pkey), 271 __u32 (*hash)(const void *pkey, 272 const struct net_device *dev, 273 __u32 *hash_rnd), 274 const void *pkey, 275 struct net_device *dev) 276 { 277 struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht); 278 struct neighbour *n; 279 u32 hash_val; 280 281 hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift); 282 for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]); 283 n != NULL; 284 n = rcu_dereference_bh(n->next)) { 285 if (n->dev == dev && key_eq(n, pkey)) 286 return n; 287 } 288 289 return NULL; 290 } 291 292 static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl, 293 const void *pkey, 294 struct net_device *dev) 295 { 296 return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev); 297 } 298 299 void neigh_table_init(int index, struct neigh_table *tbl); 300 int neigh_table_clear(int index, struct neigh_table *tbl); 301 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, 302 struct net_device *dev); 303 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net, 304 const void *pkey); 305 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey, 306 struct net_device *dev, bool want_ref); 307 static inline struct neighbour *neigh_create(struct neigh_table *tbl, 308 const void *pkey, 309 struct net_device *dev) 310 { 311 return __neigh_create(tbl, pkey, dev, true); 312 } 313 void neigh_destroy(struct neighbour *neigh); 314 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 315 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags); 316 void __neigh_set_probe_once(struct neighbour *neigh); 317 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 318 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 319 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 320 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 321 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 322 struct neighbour *neigh_event_ns(struct neigh_table *tbl, 323 u8 *lladdr, void *saddr, 324 struct net_device *dev); 325 326 struct neigh_parms *neigh_parms_alloc(struct net_device *dev, 327 struct neigh_table *tbl); 328 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 329 330 static inline 331 struct net *neigh_parms_net(const struct neigh_parms *parms) 332 { 333 return read_pnet(&parms->net); 334 } 335 336 unsigned long neigh_rand_reach_time(unsigned long base); 337 338 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 339 struct sk_buff *skb); 340 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, 341 const void *key, struct net_device *dev, 342 int creat); 343 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, 344 const void *key, struct net_device *dev); 345 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, 346 struct net_device *dev); 347 348 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh) 349 { 350 return read_pnet(&pneigh->net); 351 } 352 353 void neigh_app_ns(struct neighbour *n); 354 void neigh_for_each(struct neigh_table *tbl, 355 void (*cb)(struct neighbour *, void *), void *cookie); 356 void __neigh_for_each_release(struct neigh_table *tbl, 357 int (*cb)(struct neighbour *)); 358 int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *); 359 void pneigh_for_each(struct neigh_table *tbl, 360 void (*cb)(struct pneigh_entry *)); 361 362 struct neigh_seq_state { 363 struct seq_net_private p; 364 struct neigh_table *tbl; 365 struct neigh_hash_table *nht; 366 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 367 struct neighbour *n, loff_t *pos); 368 unsigned int bucket; 369 unsigned int flags; 370 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 371 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 372 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 373 }; 374 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, 375 unsigned int); 376 void *neigh_seq_next(struct seq_file *, void *, loff_t *); 377 void neigh_seq_stop(struct seq_file *, void *); 378 379 int neigh_proc_dointvec(struct ctl_table *ctl, int write, 380 void __user *buffer, size_t *lenp, loff_t *ppos); 381 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, 382 void __user *buffer, 383 size_t *lenp, loff_t *ppos); 384 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write, 385 void __user *buffer, 386 size_t *lenp, loff_t *ppos); 387 388 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, 389 proc_handler *proc_handler); 390 void neigh_sysctl_unregister(struct neigh_parms *p); 391 392 static inline void __neigh_parms_put(struct neigh_parms *parms) 393 { 394 atomic_dec(&parms->refcnt); 395 } 396 397 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 398 { 399 atomic_inc(&parms->refcnt); 400 return parms; 401 } 402 403 /* 404 * Neighbour references 405 */ 406 407 static inline void neigh_release(struct neighbour *neigh) 408 { 409 if (atomic_dec_and_test(&neigh->refcnt)) 410 neigh_destroy(neigh); 411 } 412 413 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 414 { 415 if (neigh) 416 atomic_inc(&neigh->refcnt); 417 return neigh; 418 } 419 420 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 421 422 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 423 { 424 unsigned long now = jiffies; 425 426 if (neigh->used != now) 427 neigh->used = now; 428 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 429 return __neigh_event_send(neigh, skb); 430 return 0; 431 } 432 433 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 434 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 435 { 436 unsigned int seq, hh_alen; 437 438 do { 439 seq = read_seqbegin(&hh->hh_lock); 440 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 441 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 442 } while (read_seqretry(&hh->hh_lock, seq)); 443 return 0; 444 } 445 #endif 446 447 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) 448 { 449 unsigned int seq; 450 int hh_len; 451 452 do { 453 seq = read_seqbegin(&hh->hh_lock); 454 hh_len = hh->hh_len; 455 if (likely(hh_len <= HH_DATA_MOD)) { 456 /* this is inlined by gcc */ 457 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD); 458 } else { 459 int hh_alen = HH_DATA_ALIGN(hh_len); 460 461 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 462 } 463 } while (read_seqretry(&hh->hh_lock, seq)); 464 465 skb_push(skb, hh_len); 466 return dev_queue_xmit(skb); 467 } 468 469 static inline struct neighbour * 470 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 471 { 472 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 473 474 if (n || !creat) 475 return n; 476 477 n = neigh_create(tbl, pkey, dev); 478 return IS_ERR(n) ? NULL : n; 479 } 480 481 static inline struct neighbour * 482 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 483 struct net_device *dev) 484 { 485 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 486 487 if (n) 488 return n; 489 490 return neigh_create(tbl, pkey, dev); 491 } 492 493 struct neighbour_cb { 494 unsigned long sched_next; 495 unsigned int flags; 496 }; 497 498 #define LOCALLY_ENQUEUED 0x1 499 500 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 501 502 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 503 const struct net_device *dev) 504 { 505 unsigned int seq; 506 507 do { 508 seq = read_seqbegin(&n->ha_lock); 509 memcpy(dst, n->ha, dev->addr_len); 510 } while (read_seqretry(&n->ha_lock, seq)); 511 } 512 513 514 #endif 515