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 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 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 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 }; 130 131 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field) 132 133 struct neighbour { 134 struct neighbour __rcu *next; 135 struct neigh_table *tbl; 136 struct neigh_parms *parms; 137 unsigned long confirmed; 138 unsigned long updated; 139 rwlock_t lock; 140 atomic_t refcnt; 141 struct sk_buff_head arp_queue; 142 unsigned int arp_queue_len_bytes; 143 struct timer_list timer; 144 unsigned long used; 145 atomic_t probes; 146 __u8 flags; 147 __u8 nud_state; 148 __u8 type; 149 __u8 dead; 150 seqlock_t ha_lock; 151 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))]; 152 struct hh_cache hh; 153 int (*output)(struct neighbour *, struct sk_buff *); 154 const struct neigh_ops *ops; 155 struct rcu_head rcu; 156 struct net_device *dev; 157 u8 primary_key[0]; 158 }; 159 160 struct neigh_ops { 161 int family; 162 void (*solicit)(struct neighbour *, struct sk_buff *); 163 void (*error_report)(struct neighbour *, struct sk_buff *); 164 int (*output)(struct neighbour *, struct sk_buff *); 165 int (*connected_output)(struct neighbour *, struct sk_buff *); 166 }; 167 168 struct pneigh_entry { 169 struct pneigh_entry *next; 170 #ifdef CONFIG_NET_NS 171 struct net *net; 172 #endif 173 struct net_device *dev; 174 u8 flags; 175 u8 key[0]; 176 }; 177 178 /* 179 * neighbour table manipulation 180 */ 181 182 #define NEIGH_NUM_HASH_RND 4 183 184 struct neigh_hash_table { 185 struct neighbour __rcu **hash_buckets; 186 unsigned int hash_shift; 187 __u32 hash_rnd[NEIGH_NUM_HASH_RND]; 188 struct rcu_head rcu; 189 }; 190 191 192 struct neigh_table { 193 int family; 194 int entry_size; 195 int key_len; 196 __be16 protocol; 197 __u32 (*hash)(const void *pkey, 198 const struct net_device *dev, 199 __u32 *hash_rnd); 200 bool (*key_eq)(const struct neighbour *, const void *pkey); 201 int (*constructor)(struct neighbour *); 202 int (*pconstructor)(struct pneigh_entry *); 203 void (*pdestructor)(struct pneigh_entry *); 204 void (*proxy_redo)(struct sk_buff *skb); 205 char *id; 206 struct neigh_parms parms; 207 struct list_head parms_list; 208 int gc_interval; 209 int gc_thresh1; 210 int gc_thresh2; 211 int gc_thresh3; 212 unsigned long last_flush; 213 struct delayed_work gc_work; 214 struct timer_list proxy_timer; 215 struct sk_buff_head proxy_queue; 216 atomic_t entries; 217 rwlock_t lock; 218 unsigned long last_rand; 219 struct neigh_statistics __percpu *stats; 220 struct neigh_hash_table __rcu *nht; 221 struct pneigh_entry **phash_buckets; 222 }; 223 224 enum { 225 NEIGH_ARP_TABLE = 0, 226 NEIGH_ND_TABLE = 1, 227 NEIGH_DN_TABLE = 2, 228 NEIGH_NR_TABLES, 229 NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */ 230 }; 231 232 static inline int neigh_parms_family(struct neigh_parms *p) 233 { 234 return p->tbl->family; 235 } 236 237 #define NEIGH_PRIV_ALIGN sizeof(long long) 238 #define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN) 239 240 static inline void *neighbour_priv(const struct neighbour *n) 241 { 242 return (char *)n + n->tbl->entry_size; 243 } 244 245 /* flags for neigh_update() */ 246 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 247 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 248 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 249 #define NEIGH_UPDATE_F_ISROUTER 0x40000000 250 #define NEIGH_UPDATE_F_ADMIN 0x80000000 251 252 253 static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey) 254 { 255 return *(const u16 *)n->primary_key == *(const u16 *)pkey; 256 } 257 258 static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey) 259 { 260 return *(const u32 *)n->primary_key == *(const u32 *)pkey; 261 } 262 263 static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey) 264 { 265 const u32 *n32 = (const u32 *)n->primary_key; 266 const u32 *p32 = pkey; 267 268 return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) | 269 (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0; 270 } 271 272 static inline struct neighbour *___neigh_lookup_noref( 273 struct neigh_table *tbl, 274 bool (*key_eq)(const struct neighbour *n, const void *pkey), 275 __u32 (*hash)(const void *pkey, 276 const struct net_device *dev, 277 __u32 *hash_rnd), 278 const void *pkey, 279 struct net_device *dev) 280 { 281 struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht); 282 struct neighbour *n; 283 u32 hash_val; 284 285 hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift); 286 for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]); 287 n != NULL; 288 n = rcu_dereference_bh(n->next)) { 289 if (n->dev == dev && key_eq(n, pkey)) 290 return n; 291 } 292 293 return NULL; 294 } 295 296 static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl, 297 const void *pkey, 298 struct net_device *dev) 299 { 300 return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev); 301 } 302 303 void neigh_table_init(int index, struct neigh_table *tbl); 304 int neigh_table_clear(int index, struct neigh_table *tbl); 305 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, 306 struct net_device *dev); 307 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net, 308 const void *pkey); 309 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey, 310 struct net_device *dev, bool want_ref); 311 static inline struct neighbour *neigh_create(struct neigh_table *tbl, 312 const void *pkey, 313 struct net_device *dev) 314 { 315 return __neigh_create(tbl, pkey, dev, true); 316 } 317 void neigh_destroy(struct neighbour *neigh); 318 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 319 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags); 320 void __neigh_set_probe_once(struct neighbour *neigh); 321 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 322 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 323 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 324 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 325 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 326 struct neighbour *neigh_event_ns(struct neigh_table *tbl, 327 u8 *lladdr, void *saddr, 328 struct net_device *dev); 329 330 struct neigh_parms *neigh_parms_alloc(struct net_device *dev, 331 struct neigh_table *tbl); 332 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 333 334 static inline 335 struct net *neigh_parms_net(const struct neigh_parms *parms) 336 { 337 return read_pnet(&parms->net); 338 } 339 340 unsigned long neigh_rand_reach_time(unsigned long base); 341 342 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 343 struct sk_buff *skb); 344 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, 345 const void *key, struct net_device *dev, 346 int creat); 347 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, 348 const void *key, struct net_device *dev); 349 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, 350 struct net_device *dev); 351 352 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh) 353 { 354 return read_pnet(&pneigh->net); 355 } 356 357 void neigh_app_ns(struct neighbour *n); 358 void neigh_for_each(struct neigh_table *tbl, 359 void (*cb)(struct neighbour *, void *), void *cookie); 360 void __neigh_for_each_release(struct neigh_table *tbl, 361 int (*cb)(struct neighbour *)); 362 int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *); 363 void pneigh_for_each(struct neigh_table *tbl, 364 void (*cb)(struct pneigh_entry *)); 365 366 struct neigh_seq_state { 367 struct seq_net_private p; 368 struct neigh_table *tbl; 369 struct neigh_hash_table *nht; 370 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 371 struct neighbour *n, loff_t *pos); 372 unsigned int bucket; 373 unsigned int flags; 374 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 375 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 376 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 377 }; 378 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, 379 unsigned int); 380 void *neigh_seq_next(struct seq_file *, void *, loff_t *); 381 void neigh_seq_stop(struct seq_file *, void *); 382 383 int neigh_proc_dointvec(struct ctl_table *ctl, int write, 384 void __user *buffer, size_t *lenp, loff_t *ppos); 385 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, 386 void __user *buffer, 387 size_t *lenp, loff_t *ppos); 388 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write, 389 void __user *buffer, 390 size_t *lenp, loff_t *ppos); 391 392 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, 393 proc_handler *proc_handler); 394 void neigh_sysctl_unregister(struct neigh_parms *p); 395 396 static inline void __neigh_parms_put(struct neigh_parms *parms) 397 { 398 atomic_dec(&parms->refcnt); 399 } 400 401 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 402 { 403 atomic_inc(&parms->refcnt); 404 return parms; 405 } 406 407 /* 408 * Neighbour references 409 */ 410 411 static inline void neigh_release(struct neighbour *neigh) 412 { 413 if (atomic_dec_and_test(&neigh->refcnt)) 414 neigh_destroy(neigh); 415 } 416 417 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 418 { 419 if (neigh) 420 atomic_inc(&neigh->refcnt); 421 return neigh; 422 } 423 424 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 425 426 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 427 { 428 unsigned long now = jiffies; 429 430 if (neigh->used != now) 431 neigh->used = now; 432 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 433 return __neigh_event_send(neigh, skb); 434 return 0; 435 } 436 437 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 438 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 439 { 440 unsigned int seq, hh_alen; 441 442 do { 443 seq = read_seqbegin(&hh->hh_lock); 444 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 445 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 446 } while (read_seqretry(&hh->hh_lock, seq)); 447 return 0; 448 } 449 #endif 450 451 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) 452 { 453 unsigned int seq; 454 int hh_len; 455 456 do { 457 seq = read_seqbegin(&hh->hh_lock); 458 hh_len = hh->hh_len; 459 if (likely(hh_len <= HH_DATA_MOD)) { 460 /* this is inlined by gcc */ 461 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD); 462 } else { 463 int hh_alen = HH_DATA_ALIGN(hh_len); 464 465 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 466 } 467 } while (read_seqretry(&hh->hh_lock, seq)); 468 469 skb_push(skb, hh_len); 470 return dev_queue_xmit(skb); 471 } 472 473 static inline struct neighbour * 474 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 475 { 476 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 477 478 if (n || !creat) 479 return n; 480 481 n = neigh_create(tbl, pkey, dev); 482 return IS_ERR(n) ? NULL : n; 483 } 484 485 static inline struct neighbour * 486 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 487 struct net_device *dev) 488 { 489 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 490 491 if (n) 492 return n; 493 494 return neigh_create(tbl, pkey, dev); 495 } 496 497 struct neighbour_cb { 498 unsigned long sched_next; 499 unsigned int flags; 500 }; 501 502 #define LOCALLY_ENQUEUED 0x1 503 504 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 505 506 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 507 const struct net_device *dev) 508 { 509 unsigned int seq; 510 511 do { 512 seq = read_seqbegin(&n->ha_lock); 513 memcpy(dst, n->ha, dev->addr_len); 514 } while (read_seqretry(&n->ha_lock, seq)); 515 } 516 517 518 #endif 519