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_MCAST_REPROBES, 46 NEIGH_VAR_RETRANS_TIME, 47 NEIGH_VAR_BASE_REACHABLE_TIME, 48 NEIGH_VAR_DELAY_PROBE_TIME, 49 NEIGH_VAR_GC_STALETIME, 50 NEIGH_VAR_QUEUE_LEN_BYTES, 51 NEIGH_VAR_PROXY_QLEN, 52 NEIGH_VAR_ANYCAST_DELAY, 53 NEIGH_VAR_PROXY_DELAY, 54 NEIGH_VAR_LOCKTIME, 55 #define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1) 56 /* Following are used as a second way to access one of the above */ 57 NEIGH_VAR_QUEUE_LEN, /* same data as NEIGH_VAR_QUEUE_LEN_BYTES */ 58 NEIGH_VAR_RETRANS_TIME_MS, /* same data as NEIGH_VAR_RETRANS_TIME */ 59 NEIGH_VAR_BASE_REACHABLE_TIME_MS, /* same data as NEIGH_VAR_BASE_REACHABLE_TIME */ 60 /* Following are used by "default" only */ 61 NEIGH_VAR_GC_INTERVAL, 62 NEIGH_VAR_GC_THRESH1, 63 NEIGH_VAR_GC_THRESH2, 64 NEIGH_VAR_GC_THRESH3, 65 NEIGH_VAR_MAX 66 }; 67 68 struct neigh_parms { 69 possible_net_t net; 70 struct net_device *dev; 71 struct list_head list; 72 int (*neigh_setup)(struct neighbour *); 73 void (*neigh_cleanup)(struct neighbour *); 74 struct neigh_table *tbl; 75 76 void *sysctl_table; 77 78 int dead; 79 atomic_t refcnt; 80 struct rcu_head rcu_head; 81 82 int reachable_time; 83 int data[NEIGH_VAR_DATA_MAX]; 84 DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX); 85 }; 86 87 static inline void neigh_var_set(struct neigh_parms *p, int index, int val) 88 { 89 set_bit(index, p->data_state); 90 p->data[index] = val; 91 } 92 93 #define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr]) 94 95 /* In ndo_neigh_setup, NEIGH_VAR_INIT should be used. 96 * In other cases, NEIGH_VAR_SET should be used. 97 */ 98 #define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val) 99 #define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val) 100 101 static inline void neigh_parms_data_state_setall(struct neigh_parms *p) 102 { 103 bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX); 104 } 105 106 static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p) 107 { 108 bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX); 109 } 110 111 struct neigh_statistics { 112 unsigned long allocs; /* number of allocated neighs */ 113 unsigned long destroys; /* number of destroyed neighs */ 114 unsigned long hash_grows; /* number of hash resizes */ 115 116 unsigned long res_failed; /* number of failed resolutions */ 117 118 unsigned long lookups; /* number of lookups */ 119 unsigned long hits; /* number of hits (among lookups) */ 120 121 unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */ 122 unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */ 123 124 unsigned long periodic_gc_runs; /* number of periodic GC runs */ 125 unsigned long forced_gc_runs; /* number of forced GC runs */ 126 127 unsigned long unres_discards; /* number of unresolved drops */ 128 }; 129 130 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field) 131 132 struct neighbour { 133 struct neighbour __rcu *next; 134 struct neigh_table *tbl; 135 struct neigh_parms *parms; 136 unsigned long confirmed; 137 unsigned long updated; 138 rwlock_t lock; 139 atomic_t refcnt; 140 struct sk_buff_head arp_queue; 141 unsigned int arp_queue_len_bytes; 142 struct timer_list timer; 143 unsigned long used; 144 atomic_t probes; 145 __u8 flags; 146 __u8 nud_state; 147 __u8 type; 148 __u8 dead; 149 seqlock_t ha_lock; 150 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))]; 151 struct hh_cache hh; 152 int (*output)(struct neighbour *, struct sk_buff *); 153 const struct neigh_ops *ops; 154 struct rcu_head rcu; 155 struct net_device *dev; 156 u8 primary_key[0]; 157 }; 158 159 struct neigh_ops { 160 int family; 161 void (*solicit)(struct neighbour *, struct sk_buff *); 162 void (*error_report)(struct neighbour *, struct sk_buff *); 163 int (*output)(struct neighbour *, struct sk_buff *); 164 int (*connected_output)(struct neighbour *, struct sk_buff *); 165 }; 166 167 struct pneigh_entry { 168 struct pneigh_entry *next; 169 possible_net_t net; 170 struct net_device *dev; 171 u8 flags; 172 u8 key[0]; 173 }; 174 175 /* 176 * neighbour table manipulation 177 */ 178 179 #define NEIGH_NUM_HASH_RND 4 180 181 struct neigh_hash_table { 182 struct neighbour __rcu **hash_buckets; 183 unsigned int hash_shift; 184 __u32 hash_rnd[NEIGH_NUM_HASH_RND]; 185 struct rcu_head rcu; 186 }; 187 188 189 struct neigh_table { 190 int family; 191 int entry_size; 192 int key_len; 193 __be16 protocol; 194 __u32 (*hash)(const void *pkey, 195 const struct net_device *dev, 196 __u32 *hash_rnd); 197 bool (*key_eq)(const struct neighbour *, const void *pkey); 198 int (*constructor)(struct neighbour *); 199 int (*pconstructor)(struct pneigh_entry *); 200 void (*pdestructor)(struct pneigh_entry *); 201 void (*proxy_redo)(struct sk_buff *skb); 202 char *id; 203 struct neigh_parms parms; 204 struct list_head parms_list; 205 int gc_interval; 206 int gc_thresh1; 207 int gc_thresh2; 208 int gc_thresh3; 209 unsigned long last_flush; 210 struct delayed_work gc_work; 211 struct timer_list proxy_timer; 212 struct sk_buff_head proxy_queue; 213 atomic_t entries; 214 rwlock_t lock; 215 unsigned long last_rand; 216 struct neigh_statistics __percpu *stats; 217 struct neigh_hash_table __rcu *nht; 218 struct pneigh_entry **phash_buckets; 219 }; 220 221 enum { 222 NEIGH_ARP_TABLE = 0, 223 NEIGH_ND_TABLE = 1, 224 NEIGH_DN_TABLE = 2, 225 NEIGH_NR_TABLES, 226 NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */ 227 }; 228 229 static inline int neigh_parms_family(struct neigh_parms *p) 230 { 231 return p->tbl->family; 232 } 233 234 #define NEIGH_PRIV_ALIGN sizeof(long long) 235 #define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN) 236 237 static inline void *neighbour_priv(const struct neighbour *n) 238 { 239 return (char *)n + n->tbl->entry_size; 240 } 241 242 /* flags for neigh_update() */ 243 #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 244 #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 245 #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 246 #define NEIGH_UPDATE_F_ISROUTER 0x40000000 247 #define NEIGH_UPDATE_F_ADMIN 0x80000000 248 249 250 static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey) 251 { 252 return *(const u16 *)n->primary_key == *(const u16 *)pkey; 253 } 254 255 static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey) 256 { 257 return *(const u32 *)n->primary_key == *(const u32 *)pkey; 258 } 259 260 static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey) 261 { 262 const u32 *n32 = (const u32 *)n->primary_key; 263 const u32 *p32 = pkey; 264 265 return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) | 266 (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0; 267 } 268 269 static inline struct neighbour *___neigh_lookup_noref( 270 struct neigh_table *tbl, 271 bool (*key_eq)(const struct neighbour *n, const void *pkey), 272 __u32 (*hash)(const void *pkey, 273 const struct net_device *dev, 274 __u32 *hash_rnd), 275 const void *pkey, 276 struct net_device *dev) 277 { 278 struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht); 279 struct neighbour *n; 280 u32 hash_val; 281 282 hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift); 283 for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]); 284 n != NULL; 285 n = rcu_dereference_bh(n->next)) { 286 if (n->dev == dev && key_eq(n, pkey)) 287 return n; 288 } 289 290 return NULL; 291 } 292 293 static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl, 294 const void *pkey, 295 struct net_device *dev) 296 { 297 return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev); 298 } 299 300 void neigh_table_init(int index, struct neigh_table *tbl); 301 int neigh_table_clear(int index, struct neigh_table *tbl); 302 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, 303 struct net_device *dev); 304 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net, 305 const void *pkey); 306 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey, 307 struct net_device *dev, bool want_ref); 308 static inline struct neighbour *neigh_create(struct neigh_table *tbl, 309 const void *pkey, 310 struct net_device *dev) 311 { 312 return __neigh_create(tbl, pkey, dev, true); 313 } 314 void neigh_destroy(struct neighbour *neigh); 315 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 316 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags); 317 void __neigh_set_probe_once(struct neighbour *neigh); 318 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 319 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 320 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 321 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 322 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 323 struct neighbour *neigh_event_ns(struct neigh_table *tbl, 324 u8 *lladdr, void *saddr, 325 struct net_device *dev); 326 327 struct neigh_parms *neigh_parms_alloc(struct net_device *dev, 328 struct neigh_table *tbl); 329 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 330 331 static inline 332 struct net *neigh_parms_net(const struct neigh_parms *parms) 333 { 334 return read_pnet(&parms->net); 335 } 336 337 unsigned long neigh_rand_reach_time(unsigned long base); 338 339 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 340 struct sk_buff *skb); 341 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, 342 const void *key, struct net_device *dev, 343 int creat); 344 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, 345 const void *key, struct net_device *dev); 346 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, 347 struct net_device *dev); 348 349 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh) 350 { 351 return read_pnet(&pneigh->net); 352 } 353 354 void neigh_app_ns(struct neighbour *n); 355 void neigh_for_each(struct neigh_table *tbl, 356 void (*cb)(struct neighbour *, void *), void *cookie); 357 void __neigh_for_each_release(struct neigh_table *tbl, 358 int (*cb)(struct neighbour *)); 359 int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *); 360 void pneigh_for_each(struct neigh_table *tbl, 361 void (*cb)(struct pneigh_entry *)); 362 363 struct neigh_seq_state { 364 struct seq_net_private p; 365 struct neigh_table *tbl; 366 struct neigh_hash_table *nht; 367 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 368 struct neighbour *n, loff_t *pos); 369 unsigned int bucket; 370 unsigned int flags; 371 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 372 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 373 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 374 }; 375 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, 376 unsigned int); 377 void *neigh_seq_next(struct seq_file *, void *, loff_t *); 378 void neigh_seq_stop(struct seq_file *, void *); 379 380 int neigh_proc_dointvec(struct ctl_table *ctl, int write, 381 void __user *buffer, size_t *lenp, loff_t *ppos); 382 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, 383 void __user *buffer, 384 size_t *lenp, loff_t *ppos); 385 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write, 386 void __user *buffer, 387 size_t *lenp, loff_t *ppos); 388 389 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, 390 proc_handler *proc_handler); 391 void neigh_sysctl_unregister(struct neigh_parms *p); 392 393 static inline void __neigh_parms_put(struct neigh_parms *parms) 394 { 395 atomic_dec(&parms->refcnt); 396 } 397 398 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 399 { 400 atomic_inc(&parms->refcnt); 401 return parms; 402 } 403 404 /* 405 * Neighbour references 406 */ 407 408 static inline void neigh_release(struct neighbour *neigh) 409 { 410 if (atomic_dec_and_test(&neigh->refcnt)) 411 neigh_destroy(neigh); 412 } 413 414 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 415 { 416 if (neigh) 417 atomic_inc(&neigh->refcnt); 418 return neigh; 419 } 420 421 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 422 423 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 424 { 425 unsigned long now = jiffies; 426 427 if (neigh->used != now) 428 neigh->used = now; 429 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 430 return __neigh_event_send(neigh, skb); 431 return 0; 432 } 433 434 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 435 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 436 { 437 unsigned int seq, hh_alen; 438 439 do { 440 seq = read_seqbegin(&hh->hh_lock); 441 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 442 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 443 } while (read_seqretry(&hh->hh_lock, seq)); 444 return 0; 445 } 446 #endif 447 448 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) 449 { 450 unsigned int seq; 451 int hh_len; 452 453 do { 454 seq = read_seqbegin(&hh->hh_lock); 455 hh_len = hh->hh_len; 456 if (likely(hh_len <= HH_DATA_MOD)) { 457 /* this is inlined by gcc */ 458 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD); 459 } else { 460 int hh_alen = HH_DATA_ALIGN(hh_len); 461 462 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 463 } 464 } while (read_seqretry(&hh->hh_lock, seq)); 465 466 skb_push(skb, hh_len); 467 return dev_queue_xmit(skb); 468 } 469 470 static inline struct neighbour * 471 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 472 { 473 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 474 475 if (n || !creat) 476 return n; 477 478 n = neigh_create(tbl, pkey, dev); 479 return IS_ERR(n) ? NULL : n; 480 } 481 482 static inline struct neighbour * 483 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 484 struct net_device *dev) 485 { 486 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 487 488 if (n) 489 return n; 490 491 return neigh_create(tbl, pkey, dev); 492 } 493 494 struct neighbour_cb { 495 unsigned long sched_next; 496 unsigned int flags; 497 }; 498 499 #define LOCALLY_ENQUEUED 0x1 500 501 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 502 503 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 504 const struct net_device *dev) 505 { 506 unsigned int seq; 507 508 do { 509 seq = read_seqbegin(&n->ha_lock); 510 memcpy(dst, n->ha, dev->addr_len); 511 } while (read_seqretry(&n->ha_lock, seq)); 512 } 513 514 515 #endif 516