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 39struct neighbour; 40 41enum { 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 68struct 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 87static 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 101static inline void neigh_parms_data_state_setall(struct neigh_parms *p) 102{ 103 bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX); 104} 105 106static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p) 107{ 108 bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX); 109} 110 111struct 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 132struct 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 159struct 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 167struct 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 181struct 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 189struct 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 221enum { 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 229static 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 237static 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 250static 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 255static 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 260static 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 269static 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 293static 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 300void neigh_table_init(int index, struct neigh_table *tbl); 301int neigh_table_clear(int index, struct neigh_table *tbl); 302struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, 303 struct net_device *dev); 304struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net, 305 const void *pkey); 306struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey, 307 struct net_device *dev, bool want_ref); 308static 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} 314void neigh_destroy(struct neighbour *neigh); 315int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 316int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags); 317void __neigh_set_probe_once(struct neighbour *neigh); 318void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 319int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 320int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 321int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 322int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 323struct neighbour *neigh_event_ns(struct neigh_table *tbl, 324 u8 *lladdr, void *saddr, 325 struct net_device *dev); 326 327struct neigh_parms *neigh_parms_alloc(struct net_device *dev, 328 struct neigh_table *tbl); 329void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 330 331static inline 332struct net *neigh_parms_net(const struct neigh_parms *parms) 333{ 334 return read_pnet(&parms->net); 335} 336 337unsigned long neigh_rand_reach_time(unsigned long base); 338 339void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 340 struct sk_buff *skb); 341struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, 342 const void *key, struct net_device *dev, 343 int creat); 344struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, 345 const void *key, struct net_device *dev); 346int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, 347 struct net_device *dev); 348 349static inline struct net *pneigh_net(const struct pneigh_entry *pneigh) 350{ 351 return read_pnet(&pneigh->net); 352} 353 354void neigh_app_ns(struct neighbour *n); 355void neigh_for_each(struct neigh_table *tbl, 356 void (*cb)(struct neighbour *, void *), void *cookie); 357void __neigh_for_each_release(struct neigh_table *tbl, 358 int (*cb)(struct neighbour *)); 359int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *); 360void pneigh_for_each(struct neigh_table *tbl, 361 void (*cb)(struct pneigh_entry *)); 362 363struct 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}; 375void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, 376 unsigned int); 377void *neigh_seq_next(struct seq_file *, void *, loff_t *); 378void neigh_seq_stop(struct seq_file *, void *); 379 380int neigh_proc_dointvec(struct ctl_table *ctl, int write, 381 void __user *buffer, size_t *lenp, loff_t *ppos); 382int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, 383 void __user *buffer, 384 size_t *lenp, loff_t *ppos); 385int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write, 386 void __user *buffer, 387 size_t *lenp, loff_t *ppos); 388 389int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, 390 proc_handler *proc_handler); 391void neigh_sysctl_unregister(struct neigh_parms *p); 392 393static inline void __neigh_parms_put(struct neigh_parms *parms) 394{ 395 atomic_dec(&parms->refcnt); 396} 397 398static 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 408static inline void neigh_release(struct neighbour *neigh) 409{ 410 if (atomic_dec_and_test(&neigh->refcnt)) 411 neigh_destroy(neigh); 412} 413 414static 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 423static 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) 435static 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 448static 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 470static 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 482static 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 494struct 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 503static 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