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11#include <linux/kernel.h>
12#include <linux/kmemcheck.h>
13#include <linux/slab.h>
14#include <linux/module.h>
15#include <net/inet_hashtables.h>
16#include <net/inet_timewait_sock.h>
17#include <net/ip.h>
18
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27
28int inet_twsk_unhash(struct inet_timewait_sock *tw)
29{
30 if (hlist_nulls_unhashed(&tw->tw_node))
31 return 0;
32
33 hlist_nulls_del_rcu(&tw->tw_node);
34 sk_nulls_node_init(&tw->tw_node);
35
36
37
38
39 return 1;
40}
41
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49
50
51int inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
52 struct inet_hashinfo *hashinfo)
53{
54 struct inet_bind_bucket *tb = tw->tw_tb;
55
56 if (!tb)
57 return 0;
58
59 __hlist_del(&tw->tw_bind_node);
60 tw->tw_tb = NULL;
61 inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
62
63
64
65
66 return 1;
67}
68
69
70static void __inet_twsk_kill(struct inet_timewait_sock *tw,
71 struct inet_hashinfo *hashinfo)
72{
73 struct inet_bind_hashbucket *bhead;
74 int refcnt;
75
76 spinlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash);
77
78 spin_lock(lock);
79 refcnt = inet_twsk_unhash(tw);
80 spin_unlock(lock);
81
82
83 bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), tw->tw_num,
84 hashinfo->bhash_size)];
85
86 spin_lock(&bhead->lock);
87 refcnt += inet_twsk_bind_unhash(tw, hashinfo);
88 spin_unlock(&bhead->lock);
89
90 BUG_ON(refcnt >= atomic_read(&tw->tw_refcnt));
91 atomic_sub(refcnt, &tw->tw_refcnt);
92}
93
94void inet_twsk_free(struct inet_timewait_sock *tw)
95{
96 struct module *owner = tw->tw_prot->owner;
97 twsk_destructor((struct sock *)tw);
98#ifdef SOCK_REFCNT_DEBUG
99 pr_debug("%s timewait_sock %p released\n", tw->tw_prot->name, tw);
100#endif
101 release_net(twsk_net(tw));
102 kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
103 module_put(owner);
104}
105
106void inet_twsk_put(struct inet_timewait_sock *tw)
107{
108 if (atomic_dec_and_test(&tw->tw_refcnt))
109 inet_twsk_free(tw);
110}
111EXPORT_SYMBOL_GPL(inet_twsk_put);
112
113static void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw,
114 struct hlist_nulls_head *list)
115{
116 hlist_nulls_add_head_rcu(&tw->tw_node, list);
117}
118
119static void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
120 struct hlist_head *list)
121{
122 hlist_add_head(&tw->tw_bind_node, list);
123}
124
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127
128
129
130void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
131 struct inet_hashinfo *hashinfo)
132{
133 const struct inet_sock *inet = inet_sk(sk);
134 const struct inet_connection_sock *icsk = inet_csk(sk);
135 struct inet_ehash_bucket *ehead = inet_ehash_bucket(hashinfo, sk->sk_hash);
136 spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
137 struct inet_bind_hashbucket *bhead;
138
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141
142 bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), inet->inet_num,
143 hashinfo->bhash_size)];
144 spin_lock(&bhead->lock);
145 tw->tw_tb = icsk->icsk_bind_hash;
146 WARN_ON(!icsk->icsk_bind_hash);
147 inet_twsk_add_bind_node(tw, &tw->tw_tb->owners);
148 spin_unlock(&bhead->lock);
149
150 spin_lock(lock);
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161 atomic_set(&tw->tw_refcnt, 1 + 1 + 1);
162 inet_twsk_add_node_rcu(tw, &ehead->chain);
163
164
165 if (__sk_nulls_del_node_init_rcu(sk))
166 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
167
168 spin_unlock(lock);
169}
170EXPORT_SYMBOL_GPL(__inet_twsk_hashdance);
171
172struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int state)
173{
174 struct inet_timewait_sock *tw =
175 kmem_cache_alloc(sk->sk_prot_creator->twsk_prot->twsk_slab,
176 GFP_ATOMIC);
177 if (tw != NULL) {
178 const struct inet_sock *inet = inet_sk(sk);
179
180 kmemcheck_annotate_bitfield(tw, flags);
181
182
183 tw->tw_daddr = inet->inet_daddr;
184 tw->tw_rcv_saddr = inet->inet_rcv_saddr;
185 tw->tw_bound_dev_if = sk->sk_bound_dev_if;
186 tw->tw_tos = inet->tos;
187 tw->tw_num = inet->inet_num;
188 tw->tw_state = TCP_TIME_WAIT;
189 tw->tw_substate = state;
190 tw->tw_sport = inet->inet_sport;
191 tw->tw_dport = inet->inet_dport;
192 tw->tw_family = sk->sk_family;
193 tw->tw_reuse = sk->sk_reuse;
194 tw->tw_hash = sk->sk_hash;
195 tw->tw_ipv6only = 0;
196 tw->tw_transparent = inet->transparent;
197 tw->tw_prot = sk->sk_prot_creator;
198 twsk_net_set(tw, hold_net(sock_net(sk)));
199
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203
204 atomic_set(&tw->tw_refcnt, 0);
205 inet_twsk_dead_node_init(tw);
206 __module_get(tw->tw_prot->owner);
207 }
208
209 return tw;
210}
211EXPORT_SYMBOL_GPL(inet_twsk_alloc);
212
213
214static int inet_twdr_do_twkill_work(struct inet_timewait_death_row *twdr,
215 const int slot)
216{
217 struct inet_timewait_sock *tw;
218 unsigned int killed;
219 int ret;
220
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227 killed = 0;
228 ret = 0;
229rescan:
230 inet_twsk_for_each_inmate(tw, &twdr->cells[slot]) {
231 __inet_twsk_del_dead_node(tw);
232 spin_unlock(&twdr->death_lock);
233 __inet_twsk_kill(tw, twdr->hashinfo);
234#ifdef CONFIG_NET_NS
235 NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITED);
236#endif
237 inet_twsk_put(tw);
238 killed++;
239 spin_lock(&twdr->death_lock);
240 if (killed > INET_TWDR_TWKILL_QUOTA) {
241 ret = 1;
242 break;
243 }
244
245
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250
251 goto rescan;
252 }
253
254 twdr->tw_count -= killed;
255#ifndef CONFIG_NET_NS
256 NET_ADD_STATS_BH(&init_net, LINUX_MIB_TIMEWAITED, killed);
257#endif
258 return ret;
259}
260
261void inet_twdr_hangman(unsigned long data)
262{
263 struct inet_timewait_death_row *twdr;
264 unsigned int need_timer;
265
266 twdr = (struct inet_timewait_death_row *)data;
267 spin_lock(&twdr->death_lock);
268
269 if (twdr->tw_count == 0)
270 goto out;
271
272 need_timer = 0;
273 if (inet_twdr_do_twkill_work(twdr, twdr->slot)) {
274 twdr->thread_slots |= (1 << twdr->slot);
275 schedule_work(&twdr->twkill_work);
276 need_timer = 1;
277 } else {
278
279 if (twdr->tw_count)
280 need_timer = 1;
281 twdr->slot = ((twdr->slot + 1) & (INET_TWDR_TWKILL_SLOTS - 1));
282 }
283 if (need_timer)
284 mod_timer(&twdr->tw_timer, jiffies + twdr->period);
285out:
286 spin_unlock(&twdr->death_lock);
287}
288EXPORT_SYMBOL_GPL(inet_twdr_hangman);
289
290void inet_twdr_twkill_work(struct work_struct *work)
291{
292 struct inet_timewait_death_row *twdr =
293 container_of(work, struct inet_timewait_death_row, twkill_work);
294 int i;
295
296 BUILD_BUG_ON((INET_TWDR_TWKILL_SLOTS - 1) >
297 (sizeof(twdr->thread_slots) * 8));
298
299 while (twdr->thread_slots) {
300 spin_lock_bh(&twdr->death_lock);
301 for (i = 0; i < INET_TWDR_TWKILL_SLOTS; i++) {
302 if (!(twdr->thread_slots & (1 << i)))
303 continue;
304
305 while (inet_twdr_do_twkill_work(twdr, i) != 0) {
306 if (need_resched()) {
307 spin_unlock_bh(&twdr->death_lock);
308 schedule();
309 spin_lock_bh(&twdr->death_lock);
310 }
311 }
312
313 twdr->thread_slots &= ~(1 << i);
314 }
315 spin_unlock_bh(&twdr->death_lock);
316 }
317}
318EXPORT_SYMBOL_GPL(inet_twdr_twkill_work);
319
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323
324
325void inet_twsk_deschedule(struct inet_timewait_sock *tw,
326 struct inet_timewait_death_row *twdr)
327{
328 spin_lock(&twdr->death_lock);
329 if (inet_twsk_del_dead_node(tw)) {
330 inet_twsk_put(tw);
331 if (--twdr->tw_count == 0)
332 del_timer(&twdr->tw_timer);
333 }
334 spin_unlock(&twdr->death_lock);
335 __inet_twsk_kill(tw, twdr->hashinfo);
336}
337EXPORT_SYMBOL(inet_twsk_deschedule);
338
339void inet_twsk_schedule(struct inet_timewait_sock *tw,
340 struct inet_timewait_death_row *twdr,
341 const int timeo, const int timewait_len)
342{
343 struct hlist_head *list;
344 int slot;
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370 slot = (timeo + (1 << INET_TWDR_RECYCLE_TICK) - 1) >> INET_TWDR_RECYCLE_TICK;
371
372 spin_lock(&twdr->death_lock);
373
374
375 if (inet_twsk_del_dead_node(tw))
376 twdr->tw_count--;
377 else
378 atomic_inc(&tw->tw_refcnt);
379
380 if (slot >= INET_TWDR_RECYCLE_SLOTS) {
381
382 if (timeo >= timewait_len) {
383 slot = INET_TWDR_TWKILL_SLOTS - 1;
384 } else {
385 slot = DIV_ROUND_UP(timeo, twdr->period);
386 if (slot >= INET_TWDR_TWKILL_SLOTS)
387 slot = INET_TWDR_TWKILL_SLOTS - 1;
388 }
389 tw->tw_ttd = inet_tw_time_stamp() + timeo;
390 slot = (twdr->slot + slot) & (INET_TWDR_TWKILL_SLOTS - 1);
391 list = &twdr->cells[slot];
392 } else {
393 tw->tw_ttd = inet_tw_time_stamp() + (slot << INET_TWDR_RECYCLE_TICK);
394
395 if (twdr->twcal_hand < 0) {
396 twdr->twcal_hand = 0;
397 twdr->twcal_jiffie = jiffies;
398 twdr->twcal_timer.expires = twdr->twcal_jiffie +
399 (slot << INET_TWDR_RECYCLE_TICK);
400 add_timer(&twdr->twcal_timer);
401 } else {
402 if (time_after(twdr->twcal_timer.expires,
403 jiffies + (slot << INET_TWDR_RECYCLE_TICK)))
404 mod_timer(&twdr->twcal_timer,
405 jiffies + (slot << INET_TWDR_RECYCLE_TICK));
406 slot = (twdr->twcal_hand + slot) & (INET_TWDR_RECYCLE_SLOTS - 1);
407 }
408 list = &twdr->twcal_row[slot];
409 }
410
411 hlist_add_head(&tw->tw_death_node, list);
412
413 if (twdr->tw_count++ == 0)
414 mod_timer(&twdr->tw_timer, jiffies + twdr->period);
415 spin_unlock(&twdr->death_lock);
416}
417EXPORT_SYMBOL_GPL(inet_twsk_schedule);
418
419void inet_twdr_twcal_tick(unsigned long data)
420{
421 struct inet_timewait_death_row *twdr;
422 int n, slot;
423 unsigned long j;
424 unsigned long now = jiffies;
425 int killed = 0;
426 int adv = 0;
427
428 twdr = (struct inet_timewait_death_row *)data;
429
430 spin_lock(&twdr->death_lock);
431 if (twdr->twcal_hand < 0)
432 goto out;
433
434 slot = twdr->twcal_hand;
435 j = twdr->twcal_jiffie;
436
437 for (n = 0; n < INET_TWDR_RECYCLE_SLOTS; n++) {
438 if (time_before_eq(j, now)) {
439 struct hlist_node *safe;
440 struct inet_timewait_sock *tw;
441
442 inet_twsk_for_each_inmate_safe(tw, safe,
443 &twdr->twcal_row[slot]) {
444 __inet_twsk_del_dead_node(tw);
445 __inet_twsk_kill(tw, twdr->hashinfo);
446#ifdef CONFIG_NET_NS
447 NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITKILLED);
448#endif
449 inet_twsk_put(tw);
450 killed++;
451 }
452 } else {
453 if (!adv) {
454 adv = 1;
455 twdr->twcal_jiffie = j;
456 twdr->twcal_hand = slot;
457 }
458
459 if (!hlist_empty(&twdr->twcal_row[slot])) {
460 mod_timer(&twdr->twcal_timer, j);
461 goto out;
462 }
463 }
464 j += 1 << INET_TWDR_RECYCLE_TICK;
465 slot = (slot + 1) & (INET_TWDR_RECYCLE_SLOTS - 1);
466 }
467 twdr->twcal_hand = -1;
468
469out:
470 if ((twdr->tw_count -= killed) == 0)
471 del_timer(&twdr->tw_timer);
472#ifndef CONFIG_NET_NS
473 NET_ADD_STATS_BH(&init_net, LINUX_MIB_TIMEWAITKILLED, killed);
474#endif
475 spin_unlock(&twdr->death_lock);
476}
477EXPORT_SYMBOL_GPL(inet_twdr_twcal_tick);
478
479void inet_twsk_purge(struct inet_hashinfo *hashinfo,
480 struct inet_timewait_death_row *twdr, int family)
481{
482 struct inet_timewait_sock *tw;
483 struct sock *sk;
484 struct hlist_nulls_node *node;
485 unsigned int slot;
486
487 for (slot = 0; slot <= hashinfo->ehash_mask; slot++) {
488 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
489restart_rcu:
490 rcu_read_lock();
491restart:
492 sk_nulls_for_each_rcu(sk, node, &head->chain) {
493 if (sk->sk_state != TCP_TIME_WAIT)
494 continue;
495 tw = inet_twsk(sk);
496 if ((tw->tw_family != family) ||
497 atomic_read(&twsk_net(tw)->count))
498 continue;
499
500 if (unlikely(!atomic_inc_not_zero(&tw->tw_refcnt)))
501 continue;
502
503 if (unlikely((tw->tw_family != family) ||
504 atomic_read(&twsk_net(tw)->count))) {
505 inet_twsk_put(tw);
506 goto restart;
507 }
508
509 rcu_read_unlock();
510 local_bh_disable();
511 inet_twsk_deschedule(tw, twdr);
512 local_bh_enable();
513 inet_twsk_put(tw);
514 goto restart_rcu;
515 }
516
517
518
519
520 if (get_nulls_value(node) != slot)
521 goto restart;
522 rcu_read_unlock();
523 }
524}
525EXPORT_SYMBOL_GPL(inet_twsk_purge);
526