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/refcount.h> 21 #include <linux/netdevice.h> 22 #include <linux/skbuff.h> 23 #include <linux/rcupdate.h> 24 #include <linux/seq_file.h> 25 #include <linux/bitmap.h> 26 27 #include <linux/err.h> 28 #include <linux/sysctl.h> 29 #include <linux/workqueue.h> 30 #include <net/rtnetlink.h> 31 32 /* 33 * NUD stands for "neighbor unreachability detection" 34 */ 35 36 #define NUD_IN_TIMER (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE) 37 #define NUD_VALID (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY) 38 #define NUD_CONNECTED (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE) 39 40 struct neighbour; 41 42 enum { 43 NEIGH_VAR_MCAST_PROBES, 44 NEIGH_VAR_UCAST_PROBES, 45 NEIGH_VAR_APP_PROBES, 46 NEIGH_VAR_MCAST_REPROBES, 47 NEIGH_VAR_RETRANS_TIME, 48 NEIGH_VAR_BASE_REACHABLE_TIME, 49 NEIGH_VAR_DELAY_PROBE_TIME, 50 NEIGH_VAR_GC_STALETIME, 51 NEIGH_VAR_QUEUE_LEN_BYTES, 52 NEIGH_VAR_PROXY_QLEN, 53 NEIGH_VAR_ANYCAST_DELAY, 54 NEIGH_VAR_PROXY_DELAY, 55 NEIGH_VAR_LOCKTIME, 56 #define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1) 57 /* Following are used as a second way to access one of the above */ 58 NEIGH_VAR_QUEUE_LEN, /* same data as NEIGH_VAR_QUEUE_LEN_BYTES */ 59 NEIGH_VAR_RETRANS_TIME_MS, /* same data as NEIGH_VAR_RETRANS_TIME */ 60 NEIGH_VAR_BASE_REACHABLE_TIME_MS, /* same data as NEIGH_VAR_BASE_REACHABLE_TIME */ 61 /* Following are used by "default" only */ 62 NEIGH_VAR_GC_INTERVAL, 63 NEIGH_VAR_GC_THRESH1, 64 NEIGH_VAR_GC_THRESH2, 65 NEIGH_VAR_GC_THRESH3, 66 NEIGH_VAR_MAX 67 }; 68 69 struct neigh_parms { 70 possible_net_t net; 71 struct net_device *dev; 72 struct list_head list; 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 refcount_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 96 /* In ndo_neigh_setup, NEIGH_VAR_INIT should be used. 97 * In other cases, NEIGH_VAR_SET should be used. 98 */ 99 #define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val) 100 #define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val) 101 102 static inline void neigh_parms_data_state_setall(struct neigh_parms *p) 103 { 104 bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX); 105 } 106 107 static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p) 108 { 109 bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX); 110 } 111 112 struct neigh_statistics { 113 unsigned long allocs; /* number of allocated neighs */ 114 unsigned long destroys; /* number of destroyed neighs */ 115 unsigned long hash_grows; /* number of hash resizes */ 116 117 unsigned long res_failed; /* number of failed resolutions */ 118 119 unsigned long lookups; /* number of lookups */ 120 unsigned long hits; /* number of hits (among lookups) */ 121 122 unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */ 123 unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */ 124 125 unsigned long periodic_gc_runs; /* number of periodic GC runs */ 126 unsigned long forced_gc_runs; /* number of forced GC runs */ 127 128 unsigned long unres_discards; /* number of unresolved drops */ 129 unsigned long table_fulls; /* times even gc couldn't help */ 130 }; 131 132 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field) 133 134 struct neighbour { 135 struct neighbour __rcu *next; 136 struct neigh_table *tbl; 137 struct neigh_parms *parms; 138 unsigned long confirmed; 139 unsigned long updated; 140 rwlock_t lock; 141 refcount_t refcnt; 142 struct sk_buff_head arp_queue; 143 unsigned int arp_queue_len_bytes; 144 struct timer_list timer; 145 unsigned long used; 146 atomic_t probes; 147 __u8 flags; 148 __u8 nud_state; 149 __u8 type; 150 __u8 dead; 151 seqlock_t ha_lock; 152 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))]; 153 struct hh_cache hh; 154 int (*output)(struct neighbour *, struct sk_buff *); 155 const struct neigh_ops *ops; 156 struct rcu_head rcu; 157 struct net_device *dev; 158 u8 primary_key[0]; 159 } __randomize_layout; 160 161 struct neigh_ops { 162 int family; 163 void (*solicit)(struct neighbour *, struct sk_buff *); 164 void (*error_report)(struct neighbour *, struct sk_buff *); 165 int (*output)(struct neighbour *, struct sk_buff *); 166 int (*connected_output)(struct neighbour *, struct sk_buff *); 167 }; 168 169 struct pneigh_entry { 170 struct pneigh_entry *next; 171 possible_net_t net; 172 struct net_device *dev; 173 u8 flags; 174 u8 key[0]; 175 }; 176 177 /* 178 * neighbour table manipulation 179 */ 180 181 #define NEIGH_NUM_HASH_RND 4 182 183 struct neigh_hash_table { 184 struct neighbour __rcu **hash_buckets; 185 unsigned int hash_shift; 186 __u32 hash_rnd[NEIGH_NUM_HASH_RND]; 187 struct rcu_head rcu; 188 }; 189 190 191 struct neigh_table { 192 int family; 193 int entry_size; 194 int key_len; 195 __be16 protocol; 196 __u32 (*hash)(const void *pkey, 197 const struct net_device *dev, 198 __u32 *hash_rnd); 199 bool (*key_eq)(const struct neighbour *, const void *pkey); 200 int (*constructor)(struct neighbour *); 201 int (*pconstructor)(struct pneigh_entry *); 202 void (*pdestructor)(struct pneigh_entry *); 203 void (*proxy_redo)(struct sk_buff *skb); 204 char *id; 205 struct neigh_parms parms; 206 struct list_head parms_list; 207 int gc_interval; 208 int gc_thresh1; 209 int gc_thresh2; 210 int gc_thresh3; 211 unsigned long last_flush; 212 struct delayed_work gc_work; 213 struct timer_list proxy_timer; 214 struct sk_buff_head proxy_queue; 215 atomic_t entries; 216 rwlock_t lock; 217 unsigned long last_rand; 218 struct neigh_statistics __percpu *stats; 219 struct neigh_hash_table __rcu *nht; 220 struct pneigh_entry **phash_buckets; 221 }; 222 223 enum { 224 NEIGH_ARP_TABLE = 0, 225 NEIGH_ND_TABLE = 1, 226 NEIGH_DN_TABLE = 2, 227 NEIGH_NR_TABLES, 228 NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */ 229 }; 230 231 static inline int neigh_parms_family(struct neigh_parms *p) 232 { 233 return p->tbl->family; 234 } 235 236 #define NEIGH_PRIV_ALIGN sizeof(long long) 237 #define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN) 238 239 static inline void *neighbour_priv(const struct neighbour *n) 240 { 241 return (char *)n + n->tbl->entry_size; 242 } 243 244 /* flags for neigh_update() */ 245 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 246 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 247 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 248 #define NEIGH_UPDATE_F_ISROUTER 0x40000000 249 #define NEIGH_UPDATE_F_ADMIN 0x80000000 250 251 252 static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey) 253 { 254 return *(const u16 *)n->primary_key == *(const u16 *)pkey; 255 } 256 257 static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey) 258 { 259 return *(const u32 *)n->primary_key == *(const u32 *)pkey; 260 } 261 262 static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey) 263 { 264 const u32 *n32 = (const u32 *)n->primary_key; 265 const u32 *p32 = pkey; 266 267 return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) | 268 (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0; 269 } 270 271 static inline struct neighbour *___neigh_lookup_noref( 272 struct neigh_table *tbl, 273 bool (*key_eq)(const struct neighbour *n, const void *pkey), 274 __u32 (*hash)(const void *pkey, 275 const struct net_device *dev, 276 __u32 *hash_rnd), 277 const void *pkey, 278 struct net_device *dev) 279 { 280 struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht); 281 struct neighbour *n; 282 u32 hash_val; 283 284 hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift); 285 for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]); 286 n != NULL; 287 n = rcu_dereference_bh(n->next)) { 288 if (n->dev == dev && key_eq(n, pkey)) 289 return n; 290 } 291 292 return NULL; 293 } 294 295 static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl, 296 const void *pkey, 297 struct net_device *dev) 298 { 299 return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev); 300 } 301 302 void neigh_table_init(int index, struct neigh_table *tbl); 303 int neigh_table_clear(int index, struct neigh_table *tbl); 304 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, 305 struct net_device *dev); 306 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net, 307 const void *pkey); 308 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey, 309 struct net_device *dev, bool want_ref); 310 static inline struct neighbour *neigh_create(struct neigh_table *tbl, 311 const void *pkey, 312 struct net_device *dev) 313 { 314 return __neigh_create(tbl, pkey, dev, true); 315 } 316 void neigh_destroy(struct neighbour *neigh); 317 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 318 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags, 319 u32 nlmsg_pid); 320 void __neigh_set_probe_once(struct neighbour *neigh); 321 bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl); 322 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 323 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 324 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 325 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 326 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 327 struct neighbour *neigh_event_ns(struct neigh_table *tbl, 328 u8 *lladdr, void *saddr, 329 struct net_device *dev); 330 331 struct neigh_parms *neigh_parms_alloc(struct net_device *dev, 332 struct neigh_table *tbl); 333 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 334 335 static inline 336 struct net *neigh_parms_net(const struct neigh_parms *parms) 337 { 338 return read_pnet(&parms->net); 339 } 340 341 unsigned long neigh_rand_reach_time(unsigned long base); 342 343 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 344 struct sk_buff *skb); 345 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, 346 const void *key, struct net_device *dev, 347 int creat); 348 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, 349 const void *key, struct net_device *dev); 350 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, 351 struct net_device *dev); 352 353 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh) 354 { 355 return read_pnet(&pneigh->net); 356 } 357 358 void neigh_app_ns(struct neighbour *n); 359 void neigh_for_each(struct neigh_table *tbl, 360 void (*cb)(struct neighbour *, void *), void *cookie); 361 void __neigh_for_each_release(struct neigh_table *tbl, 362 int (*cb)(struct neighbour *)); 363 int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *); 364 void pneigh_for_each(struct neigh_table *tbl, 365 void (*cb)(struct pneigh_entry *)); 366 367 struct neigh_seq_state { 368 struct seq_net_private p; 369 struct neigh_table *tbl; 370 struct neigh_hash_table *nht; 371 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 372 struct neighbour *n, loff_t *pos); 373 unsigned int bucket; 374 unsigned int flags; 375 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 376 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 377 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 378 }; 379 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, 380 unsigned int); 381 void *neigh_seq_next(struct seq_file *, void *, loff_t *); 382 void neigh_seq_stop(struct seq_file *, void *); 383 384 int neigh_proc_dointvec(struct ctl_table *ctl, int write, 385 void __user *buffer, size_t *lenp, loff_t *ppos); 386 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, 387 void __user *buffer, 388 size_t *lenp, loff_t *ppos); 389 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write, 390 void __user *buffer, 391 size_t *lenp, loff_t *ppos); 392 393 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, 394 proc_handler *proc_handler); 395 void neigh_sysctl_unregister(struct neigh_parms *p); 396 397 static inline void __neigh_parms_put(struct neigh_parms *parms) 398 { 399 refcount_dec(&parms->refcnt); 400 } 401 402 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 403 { 404 refcount_inc(&parms->refcnt); 405 return parms; 406 } 407 408 /* 409 * Neighbour references 410 */ 411 412 static inline void neigh_release(struct neighbour *neigh) 413 { 414 if (refcount_dec_and_test(&neigh->refcnt)) 415 neigh_destroy(neigh); 416 } 417 418 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 419 { 420 if (neigh) 421 refcount_inc(&neigh->refcnt); 422 return neigh; 423 } 424 425 #define neigh_hold(n) refcount_inc(&(n)->refcnt) 426 427 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 428 { 429 unsigned long now = jiffies; 430 431 if (neigh->used != now) 432 neigh->used = now; 433 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 434 return __neigh_event_send(neigh, skb); 435 return 0; 436 } 437 438 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 439 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 440 { 441 unsigned int seq, hh_alen; 442 443 do { 444 seq = read_seqbegin(&hh->hh_lock); 445 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 446 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 447 } while (read_seqretry(&hh->hh_lock, seq)); 448 return 0; 449 } 450 #endif 451 452 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) 453 { 454 unsigned int seq; 455 unsigned int hh_len; 456 457 do { 458 seq = read_seqbegin(&hh->hh_lock); 459 hh_len = hh->hh_len; 460 if (likely(hh_len <= HH_DATA_MOD)) { 461 /* this is inlined by gcc */ 462 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD); 463 } else { 464 unsigned int hh_alen = HH_DATA_ALIGN(hh_len); 465 466 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 467 } 468 } while (read_seqretry(&hh->hh_lock, seq)); 469 470 skb_push(skb, hh_len); 471 return dev_queue_xmit(skb); 472 } 473 474 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb) 475 { 476 const struct hh_cache *hh = &n->hh; 477 478 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len) 479 return neigh_hh_output(hh, skb); 480 else 481 return n->output(n, skb); 482 } 483 484 static inline struct neighbour * 485 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 486 { 487 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 488 489 if (n || !creat) 490 return n; 491 492 n = neigh_create(tbl, pkey, dev); 493 return IS_ERR(n) ? NULL : n; 494 } 495 496 static inline struct neighbour * 497 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 498 struct net_device *dev) 499 { 500 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 501 502 if (n) 503 return n; 504 505 return neigh_create(tbl, pkey, dev); 506 } 507 508 struct neighbour_cb { 509 unsigned long sched_next; 510 unsigned int flags; 511 }; 512 513 #define LOCALLY_ENQUEUED 0x1 514 515 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 516 517 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 518 const struct net_device *dev) 519 { 520 unsigned int seq; 521 522 do { 523 seq = read_seqbegin(&n->ha_lock); 524 memcpy(dst, n->ha, dev->addr_len); 525 } while (read_seqretry(&n->ha_lock, seq)); 526 } 527 528 529 #endif 530