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TOMOYO Linux Cross Reference
Linux/net/ipv4/inet_hashtables.c

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  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 INET transport hashtables
  7  *
  8  * Authors:     Lotsa people, from code originally in tcp
  9  *
 10  *      This program is free software; you can redistribute it and/or
 11  *      modify it under the terms of the GNU General Public License
 12  *      as published by the Free Software Foundation; either version
 13  *      2 of the License, or (at your option) any later version.
 14  */
 15 
 16 #include <linux/module.h>
 17 #include <linux/random.h>
 18 #include <linux/sched.h>
 19 #include <linux/slab.h>
 20 #include <linux/wait.h>
 21 #include <linux/vmalloc.h>
 22 
 23 #include <net/addrconf.h>
 24 #include <net/inet_connection_sock.h>
 25 #include <net/inet_hashtables.h>
 26 #include <net/secure_seq.h>
 27 #include <net/ip.h>
 28 #include <net/tcp.h>
 29 #include <net/sock_reuseport.h>
 30 
 31 static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
 32                         const __u16 lport, const __be32 faddr,
 33                         const __be16 fport)
 34 {
 35         static u32 inet_ehash_secret __read_mostly;
 36 
 37         net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret));
 38 
 39         return __inet_ehashfn(laddr, lport, faddr, fport,
 40                               inet_ehash_secret + net_hash_mix(net));
 41 }
 42 
 43 /* This function handles inet_sock, but also timewait and request sockets
 44  * for IPv4/IPv6.
 45  */
 46 u32 sk_ehashfn(const struct sock *sk)
 47 {
 48 #if IS_ENABLED(CONFIG_IPV6)
 49         if (sk->sk_family == AF_INET6 &&
 50             !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 51                 return inet6_ehashfn(sock_net(sk),
 52                                      &sk->sk_v6_rcv_saddr, sk->sk_num,
 53                                      &sk->sk_v6_daddr, sk->sk_dport);
 54 #endif
 55         return inet_ehashfn(sock_net(sk),
 56                             sk->sk_rcv_saddr, sk->sk_num,
 57                             sk->sk_daddr, sk->sk_dport);
 58 }
 59 
 60 /*
 61  * Allocate and initialize a new local port bind bucket.
 62  * The bindhash mutex for snum's hash chain must be held here.
 63  */
 64 struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
 65                                                  struct net *net,
 66                                                  struct inet_bind_hashbucket *head,
 67                                                  const unsigned short snum)
 68 {
 69         struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
 70 
 71         if (tb) {
 72                 write_pnet(&tb->ib_net, net);
 73                 tb->port      = snum;
 74                 tb->fastreuse = 0;
 75                 tb->fastreuseport = 0;
 76                 INIT_HLIST_HEAD(&tb->owners);
 77                 hlist_add_head(&tb->node, &head->chain);
 78         }
 79         return tb;
 80 }
 81 
 82 /*
 83  * Caller must hold hashbucket lock for this tb with local BH disabled
 84  */
 85 void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
 86 {
 87         if (hlist_empty(&tb->owners)) {
 88                 __hlist_del(&tb->node);
 89                 kmem_cache_free(cachep, tb);
 90         }
 91 }
 92 
 93 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
 94                     const unsigned short snum)
 95 {
 96         inet_sk(sk)->inet_num = snum;
 97         sk_add_bind_node(sk, &tb->owners);
 98         inet_csk(sk)->icsk_bind_hash = tb;
 99 }
100 
101 /*
102  * Get rid of any references to a local port held by the given sock.
103  */
104 static void __inet_put_port(struct sock *sk)
105 {
106         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
107         const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num,
108                         hashinfo->bhash_size);
109         struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
110         struct inet_bind_bucket *tb;
111 
112         spin_lock(&head->lock);
113         tb = inet_csk(sk)->icsk_bind_hash;
114         __sk_del_bind_node(sk);
115         inet_csk(sk)->icsk_bind_hash = NULL;
116         inet_sk(sk)->inet_num = 0;
117         inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
118         spin_unlock(&head->lock);
119 }
120 
121 void inet_put_port(struct sock *sk)
122 {
123         local_bh_disable();
124         __inet_put_port(sk);
125         local_bh_enable();
126 }
127 EXPORT_SYMBOL(inet_put_port);
128 
129 int __inet_inherit_port(const struct sock *sk, struct sock *child)
130 {
131         struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
132         unsigned short port = inet_sk(child)->inet_num;
133         const int bhash = inet_bhashfn(sock_net(sk), port,
134                         table->bhash_size);
135         struct inet_bind_hashbucket *head = &table->bhash[bhash];
136         struct inet_bind_bucket *tb;
137 
138         spin_lock(&head->lock);
139         tb = inet_csk(sk)->icsk_bind_hash;
140         if (unlikely(!tb)) {
141                 spin_unlock(&head->lock);
142                 return -ENOENT;
143         }
144         if (tb->port != port) {
145                 /* NOTE: using tproxy and redirecting skbs to a proxy
146                  * on a different listener port breaks the assumption
147                  * that the listener socket's icsk_bind_hash is the same
148                  * as that of the child socket. We have to look up or
149                  * create a new bind bucket for the child here. */
150                 inet_bind_bucket_for_each(tb, &head->chain) {
151                         if (net_eq(ib_net(tb), sock_net(sk)) &&
152                             tb->port == port)
153                                 break;
154                 }
155                 if (!tb) {
156                         tb = inet_bind_bucket_create(table->bind_bucket_cachep,
157                                                      sock_net(sk), head, port);
158                         if (!tb) {
159                                 spin_unlock(&head->lock);
160                                 return -ENOMEM;
161                         }
162                 }
163         }
164         inet_bind_hash(child, tb, port);
165         spin_unlock(&head->lock);
166 
167         return 0;
168 }
169 EXPORT_SYMBOL_GPL(__inet_inherit_port);
170 
171 static inline int compute_score(struct sock *sk, struct net *net,
172                                 const unsigned short hnum, const __be32 daddr,
173                                 const int dif, bool exact_dif)
174 {
175         int score = -1;
176         struct inet_sock *inet = inet_sk(sk);
177 
178         if (net_eq(sock_net(sk), net) && inet->inet_num == hnum &&
179                         !ipv6_only_sock(sk)) {
180                 __be32 rcv_saddr = inet->inet_rcv_saddr;
181                 score = sk->sk_family == PF_INET ? 2 : 1;
182                 if (rcv_saddr) {
183                         if (rcv_saddr != daddr)
184                                 return -1;
185                         score += 4;
186                 }
187                 if (sk->sk_bound_dev_if || exact_dif) {
188                         if (sk->sk_bound_dev_if != dif)
189                                 return -1;
190                         score += 4;
191                 }
192                 if (sk->sk_incoming_cpu == raw_smp_processor_id())
193                         score++;
194         }
195         return score;
196 }
197 
198 /*
199  * Here are some nice properties to exploit here. The BSD API
200  * does not allow a listening sock to specify the remote port nor the
201  * remote address for the connection. So always assume those are both
202  * wildcarded during the search since they can never be otherwise.
203  */
204 
205 /* called with rcu_read_lock() : No refcount taken on the socket */
206 struct sock *__inet_lookup_listener(struct net *net,
207                                     struct inet_hashinfo *hashinfo,
208                                     struct sk_buff *skb, int doff,
209                                     const __be32 saddr, __be16 sport,
210                                     const __be32 daddr, const unsigned short hnum,
211                                     const int dif)
212 {
213         unsigned int hash = inet_lhashfn(net, hnum);
214         struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
215         int score, hiscore = 0, matches = 0, reuseport = 0;
216         bool exact_dif = inet_exact_dif_match(net, skb);
217         struct sock *sk, *result = NULL;
218         u32 phash = 0;
219 
220         sk_for_each_rcu(sk, &ilb->head) {
221                 score = compute_score(sk, net, hnum, daddr, dif, exact_dif);
222                 if (score > hiscore) {
223                         reuseport = sk->sk_reuseport;
224                         if (reuseport) {
225                                 phash = inet_ehashfn(net, daddr, hnum,
226                                                      saddr, sport);
227                                 result = reuseport_select_sock(sk, phash,
228                                                                skb, doff);
229                                 if (result)
230                                         return result;
231                                 matches = 1;
232                         }
233                         result = sk;
234                         hiscore = score;
235                 } else if (score == hiscore && reuseport) {
236                         matches++;
237                         if (reciprocal_scale(phash, matches) == 0)
238                                 result = sk;
239                         phash = next_pseudo_random32(phash);
240                 }
241         }
242         return result;
243 }
244 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
245 
246 /* All sockets share common refcount, but have different destructors */
247 void sock_gen_put(struct sock *sk)
248 {
249         if (!atomic_dec_and_test(&sk->sk_refcnt))
250                 return;
251 
252         if (sk->sk_state == TCP_TIME_WAIT)
253                 inet_twsk_free(inet_twsk(sk));
254         else if (sk->sk_state == TCP_NEW_SYN_RECV)
255                 reqsk_free(inet_reqsk(sk));
256         else
257                 sk_free(sk);
258 }
259 EXPORT_SYMBOL_GPL(sock_gen_put);
260 
261 void sock_edemux(struct sk_buff *skb)
262 {
263         sock_gen_put(skb->sk);
264 }
265 EXPORT_SYMBOL(sock_edemux);
266 
267 struct sock *__inet_lookup_established(struct net *net,
268                                   struct inet_hashinfo *hashinfo,
269                                   const __be32 saddr, const __be16 sport,
270                                   const __be32 daddr, const u16 hnum,
271                                   const int dif)
272 {
273         INET_ADDR_COOKIE(acookie, saddr, daddr);
274         const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
275         struct sock *sk;
276         const struct hlist_nulls_node *node;
277         /* Optimize here for direct hit, only listening connections can
278          * have wildcards anyways.
279          */
280         unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
281         unsigned int slot = hash & hashinfo->ehash_mask;
282         struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
283 
284 begin:
285         sk_nulls_for_each_rcu(sk, node, &head->chain) {
286                 if (sk->sk_hash != hash)
287                         continue;
288                 if (likely(INET_MATCH(sk, net, acookie,
289                                       saddr, daddr, ports, dif))) {
290                         if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
291                                 goto out;
292                         if (unlikely(!INET_MATCH(sk, net, acookie,
293                                                  saddr, daddr, ports, dif))) {
294                                 sock_gen_put(sk);
295                                 goto begin;
296                         }
297                         goto found;
298                 }
299         }
300         /*
301          * if the nulls value we got at the end of this lookup is
302          * not the expected one, we must restart lookup.
303          * We probably met an item that was moved to another chain.
304          */
305         if (get_nulls_value(node) != slot)
306                 goto begin;
307 out:
308         sk = NULL;
309 found:
310         return sk;
311 }
312 EXPORT_SYMBOL_GPL(__inet_lookup_established);
313 
314 /* called with local bh disabled */
315 static int __inet_check_established(struct inet_timewait_death_row *death_row,
316                                     struct sock *sk, __u16 lport,
317                                     struct inet_timewait_sock **twp)
318 {
319         struct inet_hashinfo *hinfo = death_row->hashinfo;
320         struct inet_sock *inet = inet_sk(sk);
321         __be32 daddr = inet->inet_rcv_saddr;
322         __be32 saddr = inet->inet_daddr;
323         int dif = sk->sk_bound_dev_if;
324         INET_ADDR_COOKIE(acookie, saddr, daddr);
325         const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
326         struct net *net = sock_net(sk);
327         unsigned int hash = inet_ehashfn(net, daddr, lport,
328                                          saddr, inet->inet_dport);
329         struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
330         spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
331         struct sock *sk2;
332         const struct hlist_nulls_node *node;
333         struct inet_timewait_sock *tw = NULL;
334 
335         spin_lock(lock);
336 
337         sk_nulls_for_each(sk2, node, &head->chain) {
338                 if (sk2->sk_hash != hash)
339                         continue;
340 
341                 if (likely(INET_MATCH(sk2, net, acookie,
342                                          saddr, daddr, ports, dif))) {
343                         if (sk2->sk_state == TCP_TIME_WAIT) {
344                                 tw = inet_twsk(sk2);
345                                 if (twsk_unique(sk, sk2, twp))
346                                         break;
347                         }
348                         goto not_unique;
349                 }
350         }
351 
352         /* Must record num and sport now. Otherwise we will see
353          * in hash table socket with a funny identity.
354          */
355         inet->inet_num = lport;
356         inet->inet_sport = htons(lport);
357         sk->sk_hash = hash;
358         WARN_ON(!sk_unhashed(sk));
359         __sk_nulls_add_node_rcu(sk, &head->chain);
360         if (tw) {
361                 sk_nulls_del_node_init_rcu((struct sock *)tw);
362                 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
363         }
364         spin_unlock(lock);
365         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
366 
367         if (twp) {
368                 *twp = tw;
369         } else if (tw) {
370                 /* Silly. Should hash-dance instead... */
371                 inet_twsk_deschedule_put(tw);
372         }
373         return 0;
374 
375 not_unique:
376         spin_unlock(lock);
377         return -EADDRNOTAVAIL;
378 }
379 
380 static u32 inet_sk_port_offset(const struct sock *sk)
381 {
382         const struct inet_sock *inet = inet_sk(sk);
383 
384         return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
385                                           inet->inet_daddr,
386                                           inet->inet_dport);
387 }
388 
389 /* insert a socket into ehash, and eventually remove another one
390  * (The another one can be a SYN_RECV or TIMEWAIT
391  */
392 bool inet_ehash_insert(struct sock *sk, struct sock *osk)
393 {
394         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
395         struct hlist_nulls_head *list;
396         struct inet_ehash_bucket *head;
397         spinlock_t *lock;
398         bool ret = true;
399 
400         WARN_ON_ONCE(!sk_unhashed(sk));
401 
402         sk->sk_hash = sk_ehashfn(sk);
403         head = inet_ehash_bucket(hashinfo, sk->sk_hash);
404         list = &head->chain;
405         lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
406 
407         spin_lock(lock);
408         if (osk) {
409                 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
410                 ret = sk_nulls_del_node_init_rcu(osk);
411         }
412         if (ret)
413                 __sk_nulls_add_node_rcu(sk, list);
414         spin_unlock(lock);
415         return ret;
416 }
417 
418 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk)
419 {
420         bool ok = inet_ehash_insert(sk, osk);
421 
422         if (ok) {
423                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
424         } else {
425                 percpu_counter_inc(sk->sk_prot->orphan_count);
426                 sk->sk_state = TCP_CLOSE;
427                 sock_set_flag(sk, SOCK_DEAD);
428                 inet_csk_destroy_sock(sk);
429         }
430         return ok;
431 }
432 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
433 
434 static int inet_reuseport_add_sock(struct sock *sk,
435                                    struct inet_listen_hashbucket *ilb)
436 {
437         struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
438         struct sock *sk2;
439         kuid_t uid = sock_i_uid(sk);
440 
441         sk_for_each_rcu(sk2, &ilb->head) {
442                 if (sk2 != sk &&
443                     sk2->sk_family == sk->sk_family &&
444                     ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
445                     sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
446                     inet_csk(sk2)->icsk_bind_hash == tb &&
447                     sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
448                     inet_rcv_saddr_equal(sk, sk2, false))
449                         return reuseport_add_sock(sk, sk2);
450         }
451 
452         /* Initial allocation may have already happened via setsockopt */
453         if (!rcu_access_pointer(sk->sk_reuseport_cb))
454                 return reuseport_alloc(sk);
455         return 0;
456 }
457 
458 int __inet_hash(struct sock *sk, struct sock *osk)
459 {
460         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
461         struct inet_listen_hashbucket *ilb;
462         int err = 0;
463 
464         if (sk->sk_state != TCP_LISTEN) {
465                 inet_ehash_nolisten(sk, osk);
466                 return 0;
467         }
468         WARN_ON(!sk_unhashed(sk));
469         ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
470 
471         spin_lock(&ilb->lock);
472         if (sk->sk_reuseport) {
473                 err = inet_reuseport_add_sock(sk, ilb);
474                 if (err)
475                         goto unlock;
476         }
477         if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
478                 sk->sk_family == AF_INET6)
479                 hlist_add_tail_rcu(&sk->sk_node, &ilb->head);
480         else
481                 hlist_add_head_rcu(&sk->sk_node, &ilb->head);
482         sock_set_flag(sk, SOCK_RCU_FREE);
483         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
484 unlock:
485         spin_unlock(&ilb->lock);
486 
487         return err;
488 }
489 EXPORT_SYMBOL(__inet_hash);
490 
491 int inet_hash(struct sock *sk)
492 {
493         int err = 0;
494 
495         if (sk->sk_state != TCP_CLOSE) {
496                 local_bh_disable();
497                 err = __inet_hash(sk, NULL);
498                 local_bh_enable();
499         }
500 
501         return err;
502 }
503 EXPORT_SYMBOL_GPL(inet_hash);
504 
505 void inet_unhash(struct sock *sk)
506 {
507         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
508         spinlock_t *lock;
509         bool listener = false;
510         int done;
511 
512         if (sk_unhashed(sk))
513                 return;
514 
515         if (sk->sk_state == TCP_LISTEN) {
516                 lock = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)].lock;
517                 listener = true;
518         } else {
519                 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
520         }
521         spin_lock_bh(lock);
522         if (rcu_access_pointer(sk->sk_reuseport_cb))
523                 reuseport_detach_sock(sk);
524         if (listener)
525                 done = __sk_del_node_init(sk);
526         else
527                 done = __sk_nulls_del_node_init_rcu(sk);
528         if (done)
529                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
530         spin_unlock_bh(lock);
531 }
532 EXPORT_SYMBOL_GPL(inet_unhash);
533 
534 int __inet_hash_connect(struct inet_timewait_death_row *death_row,
535                 struct sock *sk, u32 port_offset,
536                 int (*check_established)(struct inet_timewait_death_row *,
537                         struct sock *, __u16, struct inet_timewait_sock **))
538 {
539         struct inet_hashinfo *hinfo = death_row->hashinfo;
540         struct inet_timewait_sock *tw = NULL;
541         struct inet_bind_hashbucket *head;
542         int port = inet_sk(sk)->inet_num;
543         struct net *net = sock_net(sk);
544         struct inet_bind_bucket *tb;
545         u32 remaining, offset;
546         int ret, i, low, high;
547         static u32 hint;
548 
549         if (port) {
550                 head = &hinfo->bhash[inet_bhashfn(net, port,
551                                                   hinfo->bhash_size)];
552                 tb = inet_csk(sk)->icsk_bind_hash;
553                 spin_lock_bh(&head->lock);
554                 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
555                         inet_ehash_nolisten(sk, NULL);
556                         spin_unlock_bh(&head->lock);
557                         return 0;
558                 }
559                 spin_unlock(&head->lock);
560                 /* No definite answer... Walk to established hash table */
561                 ret = check_established(death_row, sk, port, NULL);
562                 local_bh_enable();
563                 return ret;
564         }
565 
566         inet_get_local_port_range(net, &low, &high);
567         high++; /* [32768, 60999] -> [32768, 61000[ */
568         remaining = high - low;
569         if (likely(remaining > 1))
570                 remaining &= ~1U;
571 
572         offset = (hint + port_offset) % remaining;
573         /* In first pass we try ports of @low parity.
574          * inet_csk_get_port() does the opposite choice.
575          */
576         offset &= ~1U;
577 other_parity_scan:
578         port = low + offset;
579         for (i = 0; i < remaining; i += 2, port += 2) {
580                 if (unlikely(port >= high))
581                         port -= remaining;
582                 if (inet_is_local_reserved_port(net, port))
583                         continue;
584                 head = &hinfo->bhash[inet_bhashfn(net, port,
585                                                   hinfo->bhash_size)];
586                 spin_lock_bh(&head->lock);
587 
588                 /* Does not bother with rcv_saddr checks, because
589                  * the established check is already unique enough.
590                  */
591                 inet_bind_bucket_for_each(tb, &head->chain) {
592                         if (net_eq(ib_net(tb), net) && tb->port == port) {
593                                 if (tb->fastreuse >= 0 ||
594                                     tb->fastreuseport >= 0)
595                                         goto next_port;
596                                 WARN_ON(hlist_empty(&tb->owners));
597                                 if (!check_established(death_row, sk,
598                                                        port, &tw))
599                                         goto ok;
600                                 goto next_port;
601                         }
602                 }
603 
604                 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
605                                              net, head, port);
606                 if (!tb) {
607                         spin_unlock_bh(&head->lock);
608                         return -ENOMEM;
609                 }
610                 tb->fastreuse = -1;
611                 tb->fastreuseport = -1;
612                 goto ok;
613 next_port:
614                 spin_unlock_bh(&head->lock);
615                 cond_resched();
616         }
617 
618         offset++;
619         if ((offset & 1) && remaining > 1)
620                 goto other_parity_scan;
621 
622         return -EADDRNOTAVAIL;
623 
624 ok:
625         hint += i + 2;
626 
627         /* Head lock still held and bh's disabled */
628         inet_bind_hash(sk, tb, port);
629         if (sk_unhashed(sk)) {
630                 inet_sk(sk)->inet_sport = htons(port);
631                 inet_ehash_nolisten(sk, (struct sock *)tw);
632         }
633         if (tw)
634                 inet_twsk_bind_unhash(tw, hinfo);
635         spin_unlock(&head->lock);
636         if (tw)
637                 inet_twsk_deschedule_put(tw);
638         local_bh_enable();
639         return 0;
640 }
641 
642 /*
643  * Bind a port for a connect operation and hash it.
644  */
645 int inet_hash_connect(struct inet_timewait_death_row *death_row,
646                       struct sock *sk)
647 {
648         u32 port_offset = 0;
649 
650         if (!inet_sk(sk)->inet_num)
651                 port_offset = inet_sk_port_offset(sk);
652         return __inet_hash_connect(death_row, sk, port_offset,
653                                    __inet_check_established);
654 }
655 EXPORT_SYMBOL_GPL(inet_hash_connect);
656 
657 void inet_hashinfo_init(struct inet_hashinfo *h)
658 {
659         int i;
660 
661         for (i = 0; i < INET_LHTABLE_SIZE; i++) {
662                 spin_lock_init(&h->listening_hash[i].lock);
663                 INIT_HLIST_HEAD(&h->listening_hash[i].head);
664         }
665 }
666 EXPORT_SYMBOL_GPL(inet_hashinfo_init);
667 
668 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
669 {
670         unsigned int locksz = sizeof(spinlock_t);
671         unsigned int i, nblocks = 1;
672 
673         if (locksz != 0) {
674                 /* allocate 2 cache lines or at least one spinlock per cpu */
675                 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
676                 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
677 
678                 /* no more locks than number of hash buckets */
679                 nblocks = min(nblocks, hashinfo->ehash_mask + 1);
680 
681                 hashinfo->ehash_locks = kmalloc_array(nblocks, locksz,
682                                                       GFP_KERNEL | __GFP_NOWARN);
683                 if (!hashinfo->ehash_locks)
684                         hashinfo->ehash_locks = vmalloc(nblocks * locksz);
685 
686                 if (!hashinfo->ehash_locks)
687                         return -ENOMEM;
688 
689                 for (i = 0; i < nblocks; i++)
690                         spin_lock_init(&hashinfo->ehash_locks[i]);
691         }
692         hashinfo->ehash_locks_mask = nblocks - 1;
693         return 0;
694 }
695 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);
696 

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