tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
25#include <linux/err.h>
26#include <linux/sysctl.h>
27#include <linux/workqueue.h>
28#include <net/rtnetlink.h>
29
30/*
31 * NUD stands for "neighbor unreachability detection"
32 */
33
34#define NUD_IN_TIMER (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
35#define NUD_VALID (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
36#define NUD_CONNECTED (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
37
38struct neighbour;
39
40struct neigh_parms {
41#ifdef CONFIG_NET_NS
42 struct net *net;
43#endif
44 struct net_device *dev;
45 struct neigh_parms *next;
46 int (*neigh_setup)(struct neighbour *);
47 void (*neigh_cleanup)(struct neighbour *);
48 struct neigh_table *tbl;
49
50 void *sysctl_table;
51
52 int dead;
53 atomic_t refcnt;
54 struct rcu_head rcu_head;
55
56 int base_reachable_time;
57 int retrans_time;
58 int gc_staletime;
59 int reachable_time;
60 int delay_probe_time;
61
62 int queue_len_bytes;
63 int ucast_probes;
64 int app_probes;
65 int mcast_probes;
66 int anycast_delay;
67 int proxy_delay;
68 int proxy_qlen;
69 int locktime;
70};
71
72struct neigh_statistics {
73 unsigned long allocs; /* number of allocated neighs */
74 unsigned long destroys; /* number of destroyed neighs */
75 unsigned long hash_grows; /* number of hash resizes */
76
77 unsigned long res_failed; /* number of failed resolutions */
78
79 unsigned long lookups; /* number of lookups */
80 unsigned long hits; /* number of hits (among lookups) */
81
82 unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
83 unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
84
85 unsigned long periodic_gc_runs; /* number of periodic GC runs */
86 unsigned long forced_gc_runs; /* number of forced GC runs */
87
88 unsigned long unres_discards; /* number of unresolved drops */
89};
90
91#define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
92
93struct neighbour {
94 struct neighbour __rcu *next;
95 struct neigh_table *tbl;
96 struct neigh_parms *parms;
97 unsigned long confirmed;
98 unsigned long updated;
99 rwlock_t lock;
100 atomic_t refcnt;
101 struct sk_buff_head arp_queue;
102 unsigned int arp_queue_len_bytes;
103 struct timer_list timer;
104 unsigned long used;
105 atomic_t probes;
106 __u8 flags;
107 __u8 nud_state;
108 __u8 type;
109 __u8 dead;
110 seqlock_t ha_lock;
111 unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
112 struct hh_cache hh;
113 int (*output)(struct neighbour *, struct sk_buff *);
114 const struct neigh_ops *ops;
115 struct rcu_head rcu;
116 struct net_device *dev;
117 u8 primary_key[0];
118};
119
120struct neigh_ops {
121 int family;
122 void (*solicit)(struct neighbour *, struct sk_buff *);
123 void (*error_report)(struct neighbour *, struct sk_buff *);
124 int (*output)(struct neighbour *, struct sk_buff *);
125 int (*connected_output)(struct neighbour *, struct sk_buff *);
126};
127
128struct pneigh_entry {
129 struct pneigh_entry *next;
130#ifdef CONFIG_NET_NS
131 struct net *net;
132#endif
133 struct net_device *dev;
134 u8 flags;
135 u8 key[0];
136};
137
138/*
139 * neighbour table manipulation
140 */
141
142#define NEIGH_NUM_HASH_RND 4
143
144struct neigh_hash_table {
145 struct neighbour __rcu **hash_buckets;
146 unsigned int hash_shift;
147 __u32 hash_rnd[NEIGH_NUM_HASH_RND];
148 struct rcu_head rcu;
149};
150
151
152struct neigh_table {
153 struct neigh_table *next;
154 int family;
155 int entry_size;
156 int key_len;
157 __u32 (*hash)(const void *pkey,
158 const struct net_device *dev,
159 __u32 *hash_rnd);
160 int (*constructor)(struct neighbour *);
161 int (*pconstructor)(struct pneigh_entry *);
162 void (*pdestructor)(struct pneigh_entry *);
163 void (*proxy_redo)(struct sk_buff *skb);
164 char *id;
165 struct neigh_parms parms;
166 /* HACK. gc_* should follow parms without a gap! */
167 int gc_interval;
168 int gc_thresh1;
169 int gc_thresh2;
170 int gc_thresh3;
171 unsigned long last_flush;
172 struct delayed_work gc_work;
173 struct timer_list proxy_timer;
174 struct sk_buff_head proxy_queue;
175 atomic_t entries;
176 rwlock_t lock;
177 unsigned long last_rand;
178 struct neigh_statistics __percpu *stats;
179 struct neigh_hash_table __rcu *nht;
180 struct pneigh_entry **phash_buckets;
181};
182
183#define NEIGH_PRIV_ALIGN sizeof(long long)
184#define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN)
185
186static inline void *neighbour_priv(const struct neighbour *n)
187{
188 return (char *)n + n->tbl->entry_size;
189}
190
191/* flags for neigh_update() */
192#define NEIGH_UPDATE_F_OVERRIDE 0x00000001
193#define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002
194#define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004
195#define NEIGH_UPDATE_F_ISROUTER 0x40000000
196#define NEIGH_UPDATE_F_ADMIN 0x80000000
197
198extern void neigh_table_init(struct neigh_table *tbl);
199extern int neigh_table_clear(struct neigh_table *tbl);
200extern struct neighbour * neigh_lookup(struct neigh_table *tbl,
201 const void *pkey,
202 struct net_device *dev);
203extern struct neighbour * neigh_lookup_nodev(struct neigh_table *tbl,
204 struct net *net,
205 const void *pkey);
206extern struct neighbour * __neigh_create(struct neigh_table *tbl,
207 const void *pkey,
208 struct net_device *dev,
209 bool want_ref);
210static inline struct neighbour *neigh_create(struct neigh_table *tbl,
211 const void *pkey,
212 struct net_device *dev)
213{
214 return __neigh_create(tbl, pkey, dev, true);
215}
216extern void neigh_destroy(struct neighbour *neigh);
217extern int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
218extern int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
219 u32 flags);
220extern void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
221extern int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
222extern int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
223extern int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
224extern int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb);
225extern int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
226extern struct neighbour *neigh_event_ns(struct neigh_table *tbl,
227 u8 *lladdr, void *saddr,
228 struct net_device *dev);
229
230extern struct neigh_parms *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
231extern void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
232
233static inline
234struct net *neigh_parms_net(const struct neigh_parms *parms)
235{
236 return read_pnet(&parms->net);
237}
238
239extern unsigned long neigh_rand_reach_time(unsigned long base);
240
241extern void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
242 struct sk_buff *skb);
243extern struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);
244extern struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl,
245 struct net *net,
246 const void *key,
247 struct net_device *dev);
248extern int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);
249
250static inline
251struct net *pneigh_net(const struct pneigh_entry *pneigh)
252{
253 return read_pnet(&pneigh->net);
254}
255
256extern void neigh_app_ns(struct neighbour *n);
257extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
258extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
259extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
260
261struct neigh_seq_state {
262 struct seq_net_private p;
263 struct neigh_table *tbl;
264 struct neigh_hash_table *nht;
265 void *(*neigh_sub_iter)(struct neigh_seq_state *state,
266 struct neighbour *n, loff_t *pos);
267 unsigned int bucket;
268 unsigned int flags;
269#define NEIGH_SEQ_NEIGH_ONLY 0x00000001
270#define NEIGH_SEQ_IS_PNEIGH 0x00000002
271#define NEIGH_SEQ_SKIP_NOARP 0x00000004
272};
273extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
274extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
275extern void neigh_seq_stop(struct seq_file *, void *);
276
277extern int neigh_sysctl_register(struct net_device *dev,
278 struct neigh_parms *p,
279 char *p_name,
280 proc_handler *proc_handler);
281extern void neigh_sysctl_unregister(struct neigh_parms *p);
282
283static inline void __neigh_parms_put(struct neigh_parms *parms)
284{
285 atomic_dec(&parms->refcnt);
286}
287
288static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
289{
290 atomic_inc(&parms->refcnt);
291 return parms;
292}
293
294/*
295 * Neighbour references
296 */
297
298static inline void neigh_release(struct neighbour *neigh)
299{
300 if (atomic_dec_and_test(&neigh->refcnt))
301 neigh_destroy(neigh);
302}
303
304static inline struct neighbour * neigh_clone(struct neighbour *neigh)
305{
306 if (neigh)
307 atomic_inc(&neigh->refcnt);
308 return neigh;
309}
310
311#define neigh_hold(n) atomic_inc(&(n)->refcnt)
312
313static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
314{
315 unsigned long now = jiffies;
316
317 if (neigh->used != now)
318 neigh->used = now;
319 if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
320 return __neigh_event_send(neigh, skb);
321 return 0;
322}
323
324#ifdef CONFIG_BRIDGE_NETFILTER
325static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
326{
327 unsigned int seq, hh_alen;
328
329 do {
330 seq = read_seqbegin(&hh->hh_lock);
331 hh_alen = HH_DATA_ALIGN(ETH_HLEN);
332 memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
333 } while (read_seqretry(&hh->hh_lock, seq));
334 return 0;
335}
336#endif
337
338static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
339{
340 unsigned int seq;
341 int hh_len;
342
343 do {
344 seq = read_seqbegin(&hh->hh_lock);
345 hh_len = hh->hh_len;
346 if (likely(hh_len <= HH_DATA_MOD)) {
347 /* this is inlined by gcc */
348 memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD);
349 } else {
350 int hh_alen = HH_DATA_ALIGN(hh_len);
351
352 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
353 }
354 } while (read_seqretry(&hh->hh_lock, seq));
355
356 skb_push(skb, hh_len);
357 return dev_queue_xmit(skb);
358}
359
360static inline struct neighbour *
361__neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
362{
363 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
364
365 if (n || !creat)
366 return n;
367
368 n = neigh_create(tbl, pkey, dev);
369 return IS_ERR(n) ? NULL : n;
370}
371
372static inline struct neighbour *
373__neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
374 struct net_device *dev)
375{
376 struct neighbour *n = neigh_lookup(tbl, pkey, dev);
377
378 if (n)
379 return n;
380
381 return neigh_create(tbl, pkey, dev);
382}
383
384struct neighbour_cb {
385 unsigned long sched_next;
386 unsigned int flags;
387};
388
389#define LOCALLY_ENQUEUED 0x1
390
391#define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
392
393static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
394 const struct net_device *dev)
395{
396 unsigned int seq;
397
398 do {
399 seq = read_seqbegin(&n->ha_lock);
400 memcpy(dst, n->ha, dev->addr_len);
401 } while (read_seqretry(&n->ha_lock, seq));
402}
403#endif