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 __u32 (*hash)(const void *pkey, 197 const struct net_device *dev, 198 __u32 *hash_rnd); 199 int (*constructor)(struct neighbour *); 200 int (*pconstructor)(struct pneigh_entry *); 201 void (*pdestructor)(struct pneigh_entry *); 202 void (*proxy_redo)(struct sk_buff *skb); 203 char *id; 204 struct neigh_parms parms; 205 struct list_head parms_list; 206 int gc_interval; 207 int gc_thresh1; 208 int gc_thresh2; 209 int gc_thresh3; 210 unsigned long last_flush; 211 struct delayed_work gc_work; 212 struct timer_list proxy_timer; 213 struct sk_buff_head proxy_queue; 214 atomic_t entries; 215 rwlock_t lock; 216 unsigned long last_rand; 217 struct neigh_statistics __percpu *stats; 218 struct neigh_hash_table __rcu *nht; 219 struct pneigh_entry **phash_buckets; 220 }; 221 222 enum { 223 NEIGH_ARP_TABLE = 0, 224 NEIGH_ND_TABLE = 1, 225 NEIGH_DN_TABLE = 2, 226 NEIGH_NR_TABLES, 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 void neigh_table_init(int index, struct neigh_table *tbl); 250 int neigh_table_clear(int index, struct neigh_table *tbl); 251 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, 252 struct net_device *dev); 253 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net, 254 const void *pkey); 255 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey, 256 struct net_device *dev, bool want_ref); 257 static inline struct neighbour *neigh_create(struct neigh_table *tbl, 258 const void *pkey, 259 struct net_device *dev) 260 { 261 return __neigh_create(tbl, pkey, dev, true); 262 } 263 void neigh_destroy(struct neighbour *neigh); 264 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 265 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags); 266 void __neigh_set_probe_once(struct neighbour *neigh); 267 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 268 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 269 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); 270 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); 271 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); 272 struct neighbour *neigh_event_ns(struct neigh_table *tbl, 273 u8 *lladdr, void *saddr, 274 struct net_device *dev); 275 276 struct neigh_parms *neigh_parms_alloc(struct net_device *dev, 277 struct neigh_table *tbl); 278 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 279 280 static inline 281 struct net *neigh_parms_net(const struct neigh_parms *parms) 282 { 283 return read_pnet(&parms->net); 284 } 285 286 unsigned long neigh_rand_reach_time(unsigned long base); 287 288 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 289 struct sk_buff *skb); 290 struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, 291 const void *key, struct net_device *dev, 292 int creat); 293 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, 294 const void *key, struct net_device *dev); 295 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, 296 struct net_device *dev); 297 298 static inline struct net *pneigh_net(const struct pneigh_entry *pneigh) 299 { 300 return read_pnet(&pneigh->net); 301 } 302 303 void neigh_app_ns(struct neighbour *n); 304 void neigh_for_each(struct neigh_table *tbl, 305 void (*cb)(struct neighbour *, void *), void *cookie); 306 void __neigh_for_each_release(struct neigh_table *tbl, 307 int (*cb)(struct neighbour *)); 308 void pneigh_for_each(struct neigh_table *tbl, 309 void (*cb)(struct pneigh_entry *)); 310 311 struct neigh_seq_state { 312 struct seq_net_private p; 313 struct neigh_table *tbl; 314 struct neigh_hash_table *nht; 315 void *(*neigh_sub_iter)(struct neigh_seq_state *state, 316 struct neighbour *n, loff_t *pos); 317 unsigned int bucket; 318 unsigned int flags; 319 #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 320 #define NEIGH_SEQ_IS_PNEIGH 0x00000002 321 #define NEIGH_SEQ_SKIP_NOARP 0x00000004 322 }; 323 void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, 324 unsigned int); 325 void *neigh_seq_next(struct seq_file *, void *, loff_t *); 326 void neigh_seq_stop(struct seq_file *, void *); 327 328 int neigh_proc_dointvec(struct ctl_table *ctl, int write, 329 void __user *buffer, size_t *lenp, loff_t *ppos); 330 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, 331 void __user *buffer, 332 size_t *lenp, loff_t *ppos); 333 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write, 334 void __user *buffer, 335 size_t *lenp, loff_t *ppos); 336 337 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, 338 proc_handler *proc_handler); 339 void neigh_sysctl_unregister(struct neigh_parms *p); 340 341 static inline void __neigh_parms_put(struct neigh_parms *parms) 342 { 343 atomic_dec(&parms->refcnt); 344 } 345 346 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 347 { 348 atomic_inc(&parms->refcnt); 349 return parms; 350 } 351 352 /* 353 * Neighbour references 354 */ 355 356 static inline void neigh_release(struct neighbour *neigh) 357 { 358 if (atomic_dec_and_test(&neigh->refcnt)) 359 neigh_destroy(neigh); 360 } 361 362 static inline struct neighbour * neigh_clone(struct neighbour *neigh) 363 { 364 if (neigh) 365 atomic_inc(&neigh->refcnt); 366 return neigh; 367 } 368 369 #define neigh_hold(n) atomic_inc(&(n)->refcnt) 370 371 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 372 { 373 unsigned long now = jiffies; 374 375 if (neigh->used != now) 376 neigh->used = now; 377 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 378 return __neigh_event_send(neigh, skb); 379 return 0; 380 } 381 382 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 383 static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) 384 { 385 unsigned int seq, hh_alen; 386 387 do { 388 seq = read_seqbegin(&hh->hh_lock); 389 hh_alen = HH_DATA_ALIGN(ETH_HLEN); 390 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); 391 } while (read_seqretry(&hh->hh_lock, seq)); 392 return 0; 393 } 394 #endif 395 396 static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) 397 { 398 unsigned int seq; 399 int hh_len; 400 401 do { 402 seq = read_seqbegin(&hh->hh_lock); 403 hh_len = hh->hh_len; 404 if (likely(hh_len <= HH_DATA_MOD)) { 405 /* this is inlined by gcc */ 406 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD); 407 } else { 408 int hh_alen = HH_DATA_ALIGN(hh_len); 409 410 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 411 } 412 } while (read_seqretry(&hh->hh_lock, seq)); 413 414 skb_push(skb, hh_len); 415 return dev_queue_xmit(skb); 416 } 417 418 static inline struct neighbour * 419 __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 420 { 421 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 422 423 if (n || !creat) 424 return n; 425 426 n = neigh_create(tbl, pkey, dev); 427 return IS_ERR(n) ? NULL : n; 428 } 429 430 static inline struct neighbour * 431 __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 432 struct net_device *dev) 433 { 434 struct neighbour *n = neigh_lookup(tbl, pkey, dev); 435 436 if (n) 437 return n; 438 439 return neigh_create(tbl, pkey, dev); 440 } 441 442 struct neighbour_cb { 443 unsigned long sched_next; 444 unsigned int flags; 445 }; 446 447 #define LOCALLY_ENQUEUED 0x1 448 449 #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 450 451 static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, 452 const struct net_device *dev) 453 { 454 unsigned int seq; 455 456 do { 457 seq = read_seqbegin(&n->ha_lock); 458 memcpy(dst, n->ha, dev->addr_len); 459 } while (read_seqretry(&n->ha_lock, seq)); 460 } 461 #endif 462