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Commit | Line | Data |
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e48c414e ACM |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * Generic TIME_WAIT sockets functions | |
7 | * | |
8 | * From code orinally in TCP | |
9 | */ | |
10 | ||
172589cc | 11 | #include <linux/kernel.h> |
9e337b0f | 12 | #include <linux/kmemcheck.h> |
e48c414e ACM |
13 | #include <net/inet_hashtables.h> |
14 | #include <net/inet_timewait_sock.h> | |
696ab2d3 | 15 | #include <net/ip.h> |
e48c414e | 16 | |
13475a30 ED |
17 | |
18 | /* | |
19 | * unhash a timewait socket from established hash | |
20 | * lock must be hold by caller | |
21 | */ | |
22 | int inet_twsk_unhash(struct inet_timewait_sock *tw) | |
23 | { | |
24 | if (hlist_nulls_unhashed(&tw->tw_node)) | |
25 | return 0; | |
26 | ||
27 | hlist_nulls_del_rcu(&tw->tw_node); | |
28 | sk_nulls_node_init(&tw->tw_node); | |
29 | return 1; | |
30 | } | |
31 | ||
e48c414e | 32 | /* Must be called with locally disabled BHs. */ |
acd159b6 AB |
33 | static void __inet_twsk_kill(struct inet_timewait_sock *tw, |
34 | struct inet_hashinfo *hashinfo) | |
e48c414e ACM |
35 | { |
36 | struct inet_bind_hashbucket *bhead; | |
37 | struct inet_bind_bucket *tb; | |
13475a30 | 38 | int refcnt; |
e48c414e | 39 | /* Unlink from established hashes. */ |
9db66bdc | 40 | spinlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash); |
e48c414e | 41 | |
9db66bdc | 42 | spin_lock(lock); |
13475a30 | 43 | refcnt = inet_twsk_unhash(tw); |
9db66bdc | 44 | spin_unlock(lock); |
e48c414e ACM |
45 | |
46 | /* Disassociate with bind bucket. */ | |
7f635ab7 PE |
47 | bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), tw->tw_num, |
48 | hashinfo->bhash_size)]; | |
e48c414e ACM |
49 | spin_lock(&bhead->lock); |
50 | tb = tw->tw_tb; | |
13475a30 ED |
51 | if (tb) { |
52 | __hlist_del(&tw->tw_bind_node); | |
53 | tw->tw_tb = NULL; | |
54 | inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); | |
55 | refcnt++; | |
56 | } | |
e48c414e ACM |
57 | spin_unlock(&bhead->lock); |
58 | #ifdef SOCK_REFCNT_DEBUG | |
59 | if (atomic_read(&tw->tw_refcnt) != 1) { | |
60 | printk(KERN_DEBUG "%s timewait_sock %p refcnt=%d\n", | |
61 | tw->tw_prot->name, tw, atomic_read(&tw->tw_refcnt)); | |
62 | } | |
63 | #endif | |
13475a30 ED |
64 | while (refcnt) { |
65 | inet_twsk_put(tw); | |
66 | refcnt--; | |
67 | } | |
e48c414e ACM |
68 | } |
69 | ||
4dbc8ef7 | 70 | static noinline void inet_twsk_free(struct inet_timewait_sock *tw) |
7054fb93 | 71 | { |
4dbc8ef7 ACM |
72 | struct module *owner = tw->tw_prot->owner; |
73 | twsk_destructor((struct sock *)tw); | |
7054fb93 | 74 | #ifdef SOCK_REFCNT_DEBUG |
4dbc8ef7 | 75 | pr_debug("%s timewait_sock %p released\n", tw->tw_prot->name, tw); |
7054fb93 | 76 | #endif |
4dbc8ef7 ACM |
77 | release_net(twsk_net(tw)); |
78 | kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw); | |
79 | module_put(owner); | |
80 | } | |
81 | ||
82 | void inet_twsk_put(struct inet_timewait_sock *tw) | |
83 | { | |
84 | if (atomic_dec_and_test(&tw->tw_refcnt)) | |
85 | inet_twsk_free(tw); | |
7054fb93 PE |
86 | } |
87 | EXPORT_SYMBOL_GPL(inet_twsk_put); | |
88 | ||
e48c414e ACM |
89 | /* |
90 | * Enter the time wait state. This is called with locally disabled BH. | |
91 | * Essentially we whip up a timewait bucket, copy the relevant info into it | |
92 | * from the SK, and mess with hash chains and list linkage. | |
93 | */ | |
94 | void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, | |
95 | struct inet_hashinfo *hashinfo) | |
96 | { | |
97 | const struct inet_sock *inet = inet_sk(sk); | |
463c84b9 | 98 | const struct inet_connection_sock *icsk = inet_csk(sk); |
81c3d547 | 99 | struct inet_ehash_bucket *ehead = inet_ehash_bucket(hashinfo, sk->sk_hash); |
9db66bdc | 100 | spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash); |
e48c414e ACM |
101 | struct inet_bind_hashbucket *bhead; |
102 | /* Step 1: Put TW into bind hash. Original socket stays there too. | |
103 | Note, that any socket with inet->num != 0 MUST be bound in | |
104 | binding cache, even if it is closed. | |
105 | */ | |
c720c7e8 | 106 | bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), inet->inet_num, |
7f635ab7 | 107 | hashinfo->bhash_size)]; |
e48c414e | 108 | spin_lock(&bhead->lock); |
463c84b9 | 109 | tw->tw_tb = icsk->icsk_bind_hash; |
547b792c | 110 | WARN_ON(!icsk->icsk_bind_hash); |
e48c414e ACM |
111 | inet_twsk_add_bind_node(tw, &tw->tw_tb->owners); |
112 | spin_unlock(&bhead->lock); | |
113 | ||
9db66bdc | 114 | spin_lock(lock); |
e48c414e | 115 | |
3ab5aee7 ED |
116 | /* |
117 | * Step 2: Hash TW into TIMEWAIT chain. | |
118 | * Should be done before removing sk from established chain | |
119 | * because readers are lockless and search established first. | |
120 | */ | |
3ab5aee7 ED |
121 | inet_twsk_add_node_rcu(tw, &ehead->twchain); |
122 | ||
123 | /* Step 3: Remove SK from established hash. */ | |
124 | if (__sk_nulls_del_node_init_rcu(sk)) | |
125 | sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); | |
e48c414e | 126 | |
47e1c323 ED |
127 | /* |
128 | * Notes : | |
129 | * - We initially set tw_refcnt to 0 in inet_twsk_alloc() | |
130 | * - We add one reference for the bhash link | |
131 | * - We add one reference for the ehash link | |
132 | * - We want this refcnt update done before allowing other | |
133 | * threads to find this tw in ehash chain. | |
134 | */ | |
135 | atomic_add(1 + 1 + 1, &tw->tw_refcnt); | |
136 | ||
9db66bdc | 137 | spin_unlock(lock); |
e48c414e | 138 | } |
c676270b | 139 | |
696ab2d3 ACM |
140 | EXPORT_SYMBOL_GPL(__inet_twsk_hashdance); |
141 | ||
c676270b ACM |
142 | struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int state) |
143 | { | |
6d6ee43e ACM |
144 | struct inet_timewait_sock *tw = |
145 | kmem_cache_alloc(sk->sk_prot_creator->twsk_prot->twsk_slab, | |
54e6ecb2 | 146 | GFP_ATOMIC); |
c676270b ACM |
147 | if (tw != NULL) { |
148 | const struct inet_sock *inet = inet_sk(sk); | |
149 | ||
9e337b0f VN |
150 | kmemcheck_annotate_bitfield(tw, flags); |
151 | ||
c676270b | 152 | /* Give us an identity. */ |
c720c7e8 ED |
153 | tw->tw_daddr = inet->inet_daddr; |
154 | tw->tw_rcv_saddr = inet->inet_rcv_saddr; | |
c676270b | 155 | tw->tw_bound_dev_if = sk->sk_bound_dev_if; |
c720c7e8 | 156 | tw->tw_num = inet->inet_num; |
c676270b ACM |
157 | tw->tw_state = TCP_TIME_WAIT; |
158 | tw->tw_substate = state; | |
c720c7e8 ED |
159 | tw->tw_sport = inet->inet_sport; |
160 | tw->tw_dport = inet->inet_dport; | |
c676270b ACM |
161 | tw->tw_family = sk->sk_family; |
162 | tw->tw_reuse = sk->sk_reuse; | |
81c3d547 | 163 | tw->tw_hash = sk->sk_hash; |
c676270b | 164 | tw->tw_ipv6only = 0; |
f5715aea | 165 | tw->tw_transparent = inet->transparent; |
c676270b | 166 | tw->tw_prot = sk->sk_prot_creator; |
cd5342d9 | 167 | twsk_net_set(tw, hold_net(sock_net(sk))); |
47e1c323 ED |
168 | /* |
169 | * Because we use RCU lookups, we should not set tw_refcnt | |
170 | * to a non null value before everything is setup for this | |
171 | * timewait socket. | |
172 | */ | |
173 | atomic_set(&tw->tw_refcnt, 0); | |
c676270b | 174 | inet_twsk_dead_node_init(tw); |
eeb2b856 | 175 | __module_get(tw->tw_prot->owner); |
c676270b ACM |
176 | } |
177 | ||
178 | return tw; | |
179 | } | |
696ab2d3 ACM |
180 | |
181 | EXPORT_SYMBOL_GPL(inet_twsk_alloc); | |
182 | ||
183 | /* Returns non-zero if quota exceeded. */ | |
184 | static int inet_twdr_do_twkill_work(struct inet_timewait_death_row *twdr, | |
185 | const int slot) | |
186 | { | |
187 | struct inet_timewait_sock *tw; | |
188 | struct hlist_node *node; | |
189 | unsigned int killed; | |
190 | int ret; | |
191 | ||
192 | /* NOTE: compare this to previous version where lock | |
193 | * was released after detaching chain. It was racy, | |
194 | * because tw buckets are scheduled in not serialized context | |
195 | * in 2.3 (with netfilter), and with softnet it is common, because | |
196 | * soft irqs are not sequenced. | |
197 | */ | |
198 | killed = 0; | |
199 | ret = 0; | |
200 | rescan: | |
201 | inet_twsk_for_each_inmate(tw, node, &twdr->cells[slot]) { | |
202 | __inet_twsk_del_dead_node(tw); | |
203 | spin_unlock(&twdr->death_lock); | |
204 | __inet_twsk_kill(tw, twdr->hashinfo); | |
f2bf415c PE |
205 | #ifdef CONFIG_NET_NS |
206 | NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITED); | |
207 | #endif | |
696ab2d3 ACM |
208 | inet_twsk_put(tw); |
209 | killed++; | |
210 | spin_lock(&twdr->death_lock); | |
211 | if (killed > INET_TWDR_TWKILL_QUOTA) { | |
212 | ret = 1; | |
213 | break; | |
214 | } | |
215 | ||
216 | /* While we dropped twdr->death_lock, another cpu may have | |
217 | * killed off the next TW bucket in the list, therefore | |
218 | * do a fresh re-read of the hlist head node with the | |
219 | * lock reacquired. We still use the hlist traversal | |
220 | * macro in order to get the prefetches. | |
221 | */ | |
222 | goto rescan; | |
223 | } | |
224 | ||
225 | twdr->tw_count -= killed; | |
f2bf415c PE |
226 | #ifndef CONFIG_NET_NS |
227 | NET_ADD_STATS_BH(&init_net, LINUX_MIB_TIMEWAITED, killed); | |
228 | #endif | |
696ab2d3 ACM |
229 | return ret; |
230 | } | |
231 | ||
232 | void inet_twdr_hangman(unsigned long data) | |
233 | { | |
234 | struct inet_timewait_death_row *twdr; | |
235 | int unsigned need_timer; | |
236 | ||
237 | twdr = (struct inet_timewait_death_row *)data; | |
238 | spin_lock(&twdr->death_lock); | |
239 | ||
240 | if (twdr->tw_count == 0) | |
241 | goto out; | |
242 | ||
243 | need_timer = 0; | |
244 | if (inet_twdr_do_twkill_work(twdr, twdr->slot)) { | |
245 | twdr->thread_slots |= (1 << twdr->slot); | |
696ab2d3 ACM |
246 | schedule_work(&twdr->twkill_work); |
247 | need_timer = 1; | |
248 | } else { | |
249 | /* We purged the entire slot, anything left? */ | |
250 | if (twdr->tw_count) | |
251 | need_timer = 1; | |
80a1096b | 252 | twdr->slot = ((twdr->slot + 1) & (INET_TWDR_TWKILL_SLOTS - 1)); |
696ab2d3 | 253 | } |
696ab2d3 ACM |
254 | if (need_timer) |
255 | mod_timer(&twdr->tw_timer, jiffies + twdr->period); | |
256 | out: | |
257 | spin_unlock(&twdr->death_lock); | |
258 | } | |
259 | ||
260 | EXPORT_SYMBOL_GPL(inet_twdr_hangman); | |
261 | ||
65f27f38 | 262 | void inet_twdr_twkill_work(struct work_struct *work) |
696ab2d3 | 263 | { |
65f27f38 DH |
264 | struct inet_timewait_death_row *twdr = |
265 | container_of(work, struct inet_timewait_death_row, twkill_work); | |
696ab2d3 ACM |
266 | int i; |
267 | ||
95c9382a PE |
268 | BUILD_BUG_ON((INET_TWDR_TWKILL_SLOTS - 1) > |
269 | (sizeof(twdr->thread_slots) * 8)); | |
696ab2d3 ACM |
270 | |
271 | while (twdr->thread_slots) { | |
272 | spin_lock_bh(&twdr->death_lock); | |
273 | for (i = 0; i < INET_TWDR_TWKILL_SLOTS; i++) { | |
274 | if (!(twdr->thread_slots & (1 << i))) | |
275 | continue; | |
276 | ||
277 | while (inet_twdr_do_twkill_work(twdr, i) != 0) { | |
278 | if (need_resched()) { | |
279 | spin_unlock_bh(&twdr->death_lock); | |
280 | schedule(); | |
281 | spin_lock_bh(&twdr->death_lock); | |
282 | } | |
283 | } | |
284 | ||
285 | twdr->thread_slots &= ~(1 << i); | |
286 | } | |
287 | spin_unlock_bh(&twdr->death_lock); | |
288 | } | |
289 | } | |
290 | ||
291 | EXPORT_SYMBOL_GPL(inet_twdr_twkill_work); | |
292 | ||
293 | /* These are always called from BH context. See callers in | |
294 | * tcp_input.c to verify this. | |
295 | */ | |
296 | ||
297 | /* This is for handling early-kills of TIME_WAIT sockets. */ | |
298 | void inet_twsk_deschedule(struct inet_timewait_sock *tw, | |
299 | struct inet_timewait_death_row *twdr) | |
300 | { | |
301 | spin_lock(&twdr->death_lock); | |
302 | if (inet_twsk_del_dead_node(tw)) { | |
303 | inet_twsk_put(tw); | |
304 | if (--twdr->tw_count == 0) | |
305 | del_timer(&twdr->tw_timer); | |
306 | } | |
307 | spin_unlock(&twdr->death_lock); | |
308 | __inet_twsk_kill(tw, twdr->hashinfo); | |
309 | } | |
310 | ||
311 | EXPORT_SYMBOL(inet_twsk_deschedule); | |
312 | ||
313 | void inet_twsk_schedule(struct inet_timewait_sock *tw, | |
314 | struct inet_timewait_death_row *twdr, | |
315 | const int timeo, const int timewait_len) | |
316 | { | |
317 | struct hlist_head *list; | |
318 | int slot; | |
319 | ||
320 | /* timeout := RTO * 3.5 | |
321 | * | |
322 | * 3.5 = 1+2+0.5 to wait for two retransmits. | |
323 | * | |
324 | * RATIONALE: if FIN arrived and we entered TIME-WAIT state, | |
325 | * our ACK acking that FIN can be lost. If N subsequent retransmitted | |
326 | * FINs (or previous seqments) are lost (probability of such event | |
327 | * is p^(N+1), where p is probability to lose single packet and | |
328 | * time to detect the loss is about RTO*(2^N - 1) with exponential | |
329 | * backoff). Normal timewait length is calculated so, that we | |
330 | * waited at least for one retransmitted FIN (maximal RTO is 120sec). | |
331 | * [ BTW Linux. following BSD, violates this requirement waiting | |
332 | * only for 60sec, we should wait at least for 240 secs. | |
333 | * Well, 240 consumes too much of resources 8) | |
334 | * ] | |
335 | * This interval is not reduced to catch old duplicate and | |
336 | * responces to our wandering segments living for two MSLs. | |
337 | * However, if we use PAWS to detect | |
338 | * old duplicates, we can reduce the interval to bounds required | |
339 | * by RTO, rather than MSL. So, if peer understands PAWS, we | |
340 | * kill tw bucket after 3.5*RTO (it is important that this number | |
341 | * is greater than TS tick!) and detect old duplicates with help | |
342 | * of PAWS. | |
343 | */ | |
344 | slot = (timeo + (1 << INET_TWDR_RECYCLE_TICK) - 1) >> INET_TWDR_RECYCLE_TICK; | |
345 | ||
346 | spin_lock(&twdr->death_lock); | |
347 | ||
348 | /* Unlink it, if it was scheduled */ | |
349 | if (inet_twsk_del_dead_node(tw)) | |
350 | twdr->tw_count--; | |
351 | else | |
352 | atomic_inc(&tw->tw_refcnt); | |
353 | ||
354 | if (slot >= INET_TWDR_RECYCLE_SLOTS) { | |
355 | /* Schedule to slow timer */ | |
356 | if (timeo >= timewait_len) { | |
357 | slot = INET_TWDR_TWKILL_SLOTS - 1; | |
358 | } else { | |
172589cc | 359 | slot = DIV_ROUND_UP(timeo, twdr->period); |
696ab2d3 ACM |
360 | if (slot >= INET_TWDR_TWKILL_SLOTS) |
361 | slot = INET_TWDR_TWKILL_SLOTS - 1; | |
362 | } | |
363 | tw->tw_ttd = jiffies + timeo; | |
364 | slot = (twdr->slot + slot) & (INET_TWDR_TWKILL_SLOTS - 1); | |
365 | list = &twdr->cells[slot]; | |
366 | } else { | |
367 | tw->tw_ttd = jiffies + (slot << INET_TWDR_RECYCLE_TICK); | |
368 | ||
369 | if (twdr->twcal_hand < 0) { | |
370 | twdr->twcal_hand = 0; | |
371 | twdr->twcal_jiffie = jiffies; | |
372 | twdr->twcal_timer.expires = twdr->twcal_jiffie + | |
373 | (slot << INET_TWDR_RECYCLE_TICK); | |
374 | add_timer(&twdr->twcal_timer); | |
375 | } else { | |
376 | if (time_after(twdr->twcal_timer.expires, | |
377 | jiffies + (slot << INET_TWDR_RECYCLE_TICK))) | |
378 | mod_timer(&twdr->twcal_timer, | |
379 | jiffies + (slot << INET_TWDR_RECYCLE_TICK)); | |
380 | slot = (twdr->twcal_hand + slot) & (INET_TWDR_RECYCLE_SLOTS - 1); | |
381 | } | |
382 | list = &twdr->twcal_row[slot]; | |
383 | } | |
384 | ||
385 | hlist_add_head(&tw->tw_death_node, list); | |
386 | ||
387 | if (twdr->tw_count++ == 0) | |
388 | mod_timer(&twdr->tw_timer, jiffies + twdr->period); | |
389 | spin_unlock(&twdr->death_lock); | |
390 | } | |
391 | ||
392 | EXPORT_SYMBOL_GPL(inet_twsk_schedule); | |
393 | ||
394 | void inet_twdr_twcal_tick(unsigned long data) | |
395 | { | |
396 | struct inet_timewait_death_row *twdr; | |
397 | int n, slot; | |
398 | unsigned long j; | |
399 | unsigned long now = jiffies; | |
400 | int killed = 0; | |
401 | int adv = 0; | |
402 | ||
403 | twdr = (struct inet_timewait_death_row *)data; | |
404 | ||
405 | spin_lock(&twdr->death_lock); | |
406 | if (twdr->twcal_hand < 0) | |
407 | goto out; | |
408 | ||
409 | slot = twdr->twcal_hand; | |
410 | j = twdr->twcal_jiffie; | |
411 | ||
412 | for (n = 0; n < INET_TWDR_RECYCLE_SLOTS; n++) { | |
413 | if (time_before_eq(j, now)) { | |
414 | struct hlist_node *node, *safe; | |
415 | struct inet_timewait_sock *tw; | |
416 | ||
417 | inet_twsk_for_each_inmate_safe(tw, node, safe, | |
418 | &twdr->twcal_row[slot]) { | |
419 | __inet_twsk_del_dead_node(tw); | |
420 | __inet_twsk_kill(tw, twdr->hashinfo); | |
f2bf415c PE |
421 | #ifdef CONFIG_NET_NS |
422 | NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITKILLED); | |
423 | #endif | |
696ab2d3 ACM |
424 | inet_twsk_put(tw); |
425 | killed++; | |
426 | } | |
427 | } else { | |
428 | if (!adv) { | |
429 | adv = 1; | |
430 | twdr->twcal_jiffie = j; | |
431 | twdr->twcal_hand = slot; | |
432 | } | |
433 | ||
434 | if (!hlist_empty(&twdr->twcal_row[slot])) { | |
435 | mod_timer(&twdr->twcal_timer, j); | |
436 | goto out; | |
437 | } | |
438 | } | |
439 | j += 1 << INET_TWDR_RECYCLE_TICK; | |
440 | slot = (slot + 1) & (INET_TWDR_RECYCLE_SLOTS - 1); | |
441 | } | |
442 | twdr->twcal_hand = -1; | |
443 | ||
444 | out: | |
445 | if ((twdr->tw_count -= killed) == 0) | |
446 | del_timer(&twdr->tw_timer); | |
f2bf415c PE |
447 | #ifndef CONFIG_NET_NS |
448 | NET_ADD_STATS_BH(&init_net, LINUX_MIB_TIMEWAITKILLED, killed); | |
449 | #endif | |
696ab2d3 ACM |
450 | spin_unlock(&twdr->death_lock); |
451 | } | |
452 | ||
453 | EXPORT_SYMBOL_GPL(inet_twdr_twcal_tick); | |
d315492b | 454 | |
b099ce26 | 455 | void inet_twsk_purge(struct inet_hashinfo *hashinfo, |
d315492b DL |
456 | struct inet_timewait_death_row *twdr, int family) |
457 | { | |
458 | struct inet_timewait_sock *tw; | |
459 | struct sock *sk; | |
3ab5aee7 | 460 | struct hlist_nulls_node *node; |
575f4cd5 | 461 | unsigned int slot; |
d315492b | 462 | |
575f4cd5 EB |
463 | for (slot = 0; slot <= hashinfo->ehash_mask; slot++) { |
464 | struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; | |
465 | restart_rcu: | |
466 | rcu_read_lock(); | |
d315492b | 467 | restart: |
575f4cd5 | 468 | sk_nulls_for_each_rcu(sk, node, &head->twchain) { |
d315492b | 469 | tw = inet_twsk(sk); |
b099ce26 EB |
470 | if ((tw->tw_family != family) || |
471 | atomic_read(&twsk_net(tw)->count)) | |
d315492b DL |
472 | continue; |
473 | ||
575f4cd5 EB |
474 | if (unlikely(!atomic_inc_not_zero(&tw->tw_refcnt))) |
475 | continue; | |
476 | ||
b099ce26 EB |
477 | if (unlikely((tw->tw_family != family) || |
478 | atomic_read(&twsk_net(tw)->count))) { | |
575f4cd5 EB |
479 | inet_twsk_put(tw); |
480 | goto restart; | |
481 | } | |
482 | ||
483 | rcu_read_unlock(); | |
d315492b DL |
484 | inet_twsk_deschedule(tw, twdr); |
485 | inet_twsk_put(tw); | |
575f4cd5 | 486 | goto restart_rcu; |
d315492b | 487 | } |
575f4cd5 EB |
488 | /* If the nulls value we got at the end of this lookup is |
489 | * not the expected one, we must restart lookup. | |
490 | * We probably met an item that was moved to another chain. | |
491 | */ | |
492 | if (get_nulls_value(node) != slot) | |
493 | goto restart; | |
494 | rcu_read_unlock(); | |
d315492b | 495 | } |
d315492b DL |
496 | } |
497 | EXPORT_SYMBOL_GPL(inet_twsk_purge); |