~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

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

Version: ~ [ linux-5.10-rc5 ] ~ [ linux-5.9.10 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.79 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.159 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.208 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.245 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.245 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 #include <linux/bootmem.h>
 23 
 24 #include <net/addrconf.h>
 25 #include <net/inet_connection_sock.h>
 26 #include <net/inet_hashtables.h>
 27 #include <net/secure_seq.h>
 28 #include <net/ip.h>
 29 #include <net/tcp.h>
 30 #include <net/sock_reuseport.h>
 31 
 32 static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
 33                         const __u16 lport, const __be32 faddr,
 34                         const __be16 fport)
 35 {
 36         static u32 inet_ehash_secret __read_mostly;
 37 
 38         net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret));
 39 
 40         return __inet_ehashfn(laddr, lport, faddr, fport,
 41                               inet_ehash_secret + net_hash_mix(net));
 42 }
 43 
 44 /* This function handles inet_sock, but also timewait and request sockets
 45  * for IPv4/IPv6.
 46  */
 47 static u32 sk_ehashfn(const struct sock *sk)
 48 {
 49 #if IS_ENABLED(CONFIG_IPV6)
 50         if (sk->sk_family == AF_INET6 &&
 51             !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 52                 return inet6_ehashfn(sock_net(sk),
 53                                      &sk->sk_v6_rcv_saddr, sk->sk_num,
 54                                      &sk->sk_v6_daddr, sk->sk_dport);
 55 #endif
 56         return inet_ehashfn(sock_net(sk),
 57                             sk->sk_rcv_saddr, sk->sk_num,
 58                             sk->sk_daddr, sk->sk_dport);
 59 }
 60 
 61 /*
 62  * Allocate and initialize a new local port bind bucket.
 63  * The bindhash mutex for snum's hash chain must be held here.
 64  */
 65 struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
 66                                                  struct net *net,
 67                                                  struct inet_bind_hashbucket *head,
 68                                                  const unsigned short snum)
 69 {
 70         struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
 71 
 72         if (tb) {
 73                 write_pnet(&tb->ib_net, net);
 74                 tb->port      = snum;
 75                 tb->fastreuse = 0;
 76                 tb->fastreuseport = 0;
 77                 INIT_HLIST_HEAD(&tb->owners);
 78                 hlist_add_head(&tb->node, &head->chain);
 79         }
 80         return tb;
 81 }
 82 
 83 /*
 84  * Caller must hold hashbucket lock for this tb with local BH disabled
 85  */
 86 void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
 87 {
 88         if (hlist_empty(&tb->owners)) {
 89                 __hlist_del(&tb->node);
 90                 kmem_cache_free(cachep, tb);
 91         }
 92 }
 93 
 94 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
 95                     const unsigned short snum)
 96 {
 97         inet_sk(sk)->inet_num = snum;
 98         sk_add_bind_node(sk, &tb->owners);
 99         inet_csk(sk)->icsk_bind_hash = tb;
100 }
101 
102 /*
103  * Get rid of any references to a local port held by the given sock.
104  */
105 static void __inet_put_port(struct sock *sk)
106 {
107         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
108         const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num,
109                         hashinfo->bhash_size);
110         struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
111         struct inet_bind_bucket *tb;
112 
113         spin_lock(&head->lock);
114         tb = inet_csk(sk)->icsk_bind_hash;
115         __sk_del_bind_node(sk);
116         inet_csk(sk)->icsk_bind_hash = NULL;
117         inet_sk(sk)->inet_num = 0;
118         inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
119         spin_unlock(&head->lock);
120 }
121 
122 void inet_put_port(struct sock *sk)
123 {
124         local_bh_disable();
125         __inet_put_port(sk);
126         local_bh_enable();
127 }
128 EXPORT_SYMBOL(inet_put_port);
129 
130 int __inet_inherit_port(const struct sock *sk, struct sock *child)
131 {
132         struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
133         unsigned short port = inet_sk(child)->inet_num;
134         const int bhash = inet_bhashfn(sock_net(sk), port,
135                         table->bhash_size);
136         struct inet_bind_hashbucket *head = &table->bhash[bhash];
137         struct inet_bind_bucket *tb;
138 
139         spin_lock(&head->lock);
140         tb = inet_csk(sk)->icsk_bind_hash;
141         if (unlikely(!tb)) {
142                 spin_unlock(&head->lock);
143                 return -ENOENT;
144         }
145         if (tb->port != port) {
146                 /* NOTE: using tproxy and redirecting skbs to a proxy
147                  * on a different listener port breaks the assumption
148                  * that the listener socket's icsk_bind_hash is the same
149                  * as that of the child socket. We have to look up or
150                  * create a new bind bucket for the child here. */
151                 inet_bind_bucket_for_each(tb, &head->chain) {
152                         if (net_eq(ib_net(tb), sock_net(sk)) &&
153                             tb->port == port)
154                                 break;
155                 }
156                 if (!tb) {
157                         tb = inet_bind_bucket_create(table->bind_bucket_cachep,
158                                                      sock_net(sk), head, port);
159                         if (!tb) {
160                                 spin_unlock(&head->lock);
161                                 return -ENOMEM;
162                         }
163                 }
164         }
165         inet_bind_hash(child, tb, port);
166         spin_unlock(&head->lock);
167 
168         return 0;
169 }
170 EXPORT_SYMBOL_GPL(__inet_inherit_port);
171 
172 static struct inet_listen_hashbucket *
173 inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk)
174 {
175         u32 hash;
176 
177 #if IS_ENABLED(CONFIG_IPV6)
178         if (sk->sk_family == AF_INET6)
179                 hash = ipv6_portaddr_hash(sock_net(sk),
180                                           &sk->sk_v6_rcv_saddr,
181                                           inet_sk(sk)->inet_num);
182         else
183 #endif
184                 hash = ipv4_portaddr_hash(sock_net(sk),
185                                           inet_sk(sk)->inet_rcv_saddr,
186                                           inet_sk(sk)->inet_num);
187         return inet_lhash2_bucket(h, hash);
188 }
189 
190 static void inet_hash2(struct inet_hashinfo *h, struct sock *sk)
191 {
192         struct inet_listen_hashbucket *ilb2;
193 
194         if (!h->lhash2)
195                 return;
196 
197         ilb2 = inet_lhash2_bucket_sk(h, sk);
198 
199         spin_lock(&ilb2->lock);
200         if (sk->sk_reuseport && sk->sk_family == AF_INET6)
201                 hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,
202                                    &ilb2->head);
203         else
204                 hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,
205                                    &ilb2->head);
206         ilb2->count++;
207         spin_unlock(&ilb2->lock);
208 }
209 
210 static void inet_unhash2(struct inet_hashinfo *h, struct sock *sk)
211 {
212         struct inet_listen_hashbucket *ilb2;
213 
214         if (!h->lhash2 ||
215             WARN_ON_ONCE(hlist_unhashed(&inet_csk(sk)->icsk_listen_portaddr_node)))
216                 return;
217 
218         ilb2 = inet_lhash2_bucket_sk(h, sk);
219 
220         spin_lock(&ilb2->lock);
221         hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node);
222         ilb2->count--;
223         spin_unlock(&ilb2->lock);
224 }
225 
226 static inline int compute_score(struct sock *sk, struct net *net,
227                                 const unsigned short hnum, const __be32 daddr,
228                                 const int dif, const int sdif, bool exact_dif)
229 {
230         int score = -1;
231         struct inet_sock *inet = inet_sk(sk);
232 
233         if (net_eq(sock_net(sk), net) && inet->inet_num == hnum &&
234                         !ipv6_only_sock(sk)) {
235                 __be32 rcv_saddr = inet->inet_rcv_saddr;
236                 score = sk->sk_family == PF_INET ? 2 : 1;
237                 if (rcv_saddr) {
238                         if (rcv_saddr != daddr)
239                                 return -1;
240                         score += 4;
241                 }
242                 if (sk->sk_bound_dev_if || exact_dif) {
243                         bool dev_match = (sk->sk_bound_dev_if == dif ||
244                                           sk->sk_bound_dev_if == sdif);
245 
246                         if (!dev_match)
247                                 return -1;
248                         if (sk->sk_bound_dev_if)
249                                 score += 4;
250                 }
251                 if (sk->sk_incoming_cpu == raw_smp_processor_id())
252                         score++;
253         }
254         return score;
255 }
256 
257 /*
258  * Here are some nice properties to exploit here. The BSD API
259  * does not allow a listening sock to specify the remote port nor the
260  * remote address for the connection. So always assume those are both
261  * wildcarded during the search since they can never be otherwise.
262  */
263 
264 /* called with rcu_read_lock() : No refcount taken on the socket */
265 static struct sock *inet_lhash2_lookup(struct net *net,
266                                 struct inet_listen_hashbucket *ilb2,
267                                 struct sk_buff *skb, int doff,
268                                 const __be32 saddr, __be16 sport,
269                                 const __be32 daddr, const unsigned short hnum,
270                                 const int dif, const int sdif)
271 {
272         bool exact_dif = inet_exact_dif_match(net, skb);
273         struct inet_connection_sock *icsk;
274         struct sock *sk, *result = NULL;
275         int score, hiscore = 0;
276         u32 phash = 0;
277 
278         inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
279                 sk = (struct sock *)icsk;
280                 score = compute_score(sk, net, hnum, daddr,
281                                       dif, sdif, exact_dif);
282                 if (score > hiscore) {
283                         if (sk->sk_reuseport) {
284                                 phash = inet_ehashfn(net, daddr, hnum,
285                                                      saddr, sport);
286                                 result = reuseport_select_sock(sk, phash,
287                                                                skb, doff);
288                                 if (result)
289                                         return result;
290                         }
291                         result = sk;
292                         hiscore = score;
293                 }
294         }
295 
296         return result;
297 }
298 
299 struct sock *__inet_lookup_listener(struct net *net,
300                                     struct inet_hashinfo *hashinfo,
301                                     struct sk_buff *skb, int doff,
302                                     const __be32 saddr, __be16 sport,
303                                     const __be32 daddr, const unsigned short hnum,
304                                     const int dif, const int sdif)
305 {
306         unsigned int hash = inet_lhashfn(net, hnum);
307         struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
308         bool exact_dif = inet_exact_dif_match(net, skb);
309         struct inet_listen_hashbucket *ilb2;
310         struct sock *sk, *result = NULL;
311         int score, hiscore = 0;
312         unsigned int hash2;
313         u32 phash = 0;
314 
315         if (ilb->count <= 10 || !hashinfo->lhash2)
316                 goto port_lookup;
317 
318         /* Too many sk in the ilb bucket (which is hashed by port alone).
319          * Try lhash2 (which is hashed by port and addr) instead.
320          */
321 
322         hash2 = ipv4_portaddr_hash(net, daddr, hnum);
323         ilb2 = inet_lhash2_bucket(hashinfo, hash2);
324         if (ilb2->count > ilb->count)
325                 goto port_lookup;
326 
327         result = inet_lhash2_lookup(net, ilb2, skb, doff,
328                                     saddr, sport, daddr, hnum,
329                                     dif, sdif);
330         if (result)
331                 return result;
332 
333         /* Lookup lhash2 with INADDR_ANY */
334 
335         hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
336         ilb2 = inet_lhash2_bucket(hashinfo, hash2);
337         if (ilb2->count > ilb->count)
338                 goto port_lookup;
339 
340         return inet_lhash2_lookup(net, ilb2, skb, doff,
341                                   saddr, sport, daddr, hnum,
342                                   dif, sdif);
343 
344 port_lookup:
345         sk_for_each_rcu(sk, &ilb->head) {
346                 score = compute_score(sk, net, hnum, daddr,
347                                       dif, sdif, exact_dif);
348                 if (score > hiscore) {
349                         if (sk->sk_reuseport) {
350                                 phash = inet_ehashfn(net, daddr, hnum,
351                                                      saddr, sport);
352                                 result = reuseport_select_sock(sk, phash,
353                                                                skb, doff);
354                                 if (result)
355                                         return result;
356                         }
357                         result = sk;
358                         hiscore = score;
359                 }
360         }
361         return result;
362 }
363 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
364 
365 /* All sockets share common refcount, but have different destructors */
366 void sock_gen_put(struct sock *sk)
367 {
368         if (!refcount_dec_and_test(&sk->sk_refcnt))
369                 return;
370 
371         if (sk->sk_state == TCP_TIME_WAIT)
372                 inet_twsk_free(inet_twsk(sk));
373         else if (sk->sk_state == TCP_NEW_SYN_RECV)
374                 reqsk_free(inet_reqsk(sk));
375         else
376                 sk_free(sk);
377 }
378 EXPORT_SYMBOL_GPL(sock_gen_put);
379 
380 void sock_edemux(struct sk_buff *skb)
381 {
382         sock_gen_put(skb->sk);
383 }
384 EXPORT_SYMBOL(sock_edemux);
385 
386 struct sock *__inet_lookup_established(struct net *net,
387                                   struct inet_hashinfo *hashinfo,
388                                   const __be32 saddr, const __be16 sport,
389                                   const __be32 daddr, const u16 hnum,
390                                   const int dif, const int sdif)
391 {
392         INET_ADDR_COOKIE(acookie, saddr, daddr);
393         const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
394         struct sock *sk;
395         const struct hlist_nulls_node *node;
396         /* Optimize here for direct hit, only listening connections can
397          * have wildcards anyways.
398          */
399         unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
400         unsigned int slot = hash & hashinfo->ehash_mask;
401         struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
402 
403 begin:
404         sk_nulls_for_each_rcu(sk, node, &head->chain) {
405                 if (sk->sk_hash != hash)
406                         continue;
407                 if (likely(INET_MATCH(sk, net, acookie,
408                                       saddr, daddr, ports, dif, sdif))) {
409                         if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
410                                 goto out;
411                         if (unlikely(!INET_MATCH(sk, net, acookie,
412                                                  saddr, daddr, ports,
413                                                  dif, sdif))) {
414                                 sock_gen_put(sk);
415                                 goto begin;
416                         }
417                         goto found;
418                 }
419         }
420         /*
421          * if the nulls value we got at the end of this lookup is
422          * not the expected one, we must restart lookup.
423          * We probably met an item that was moved to another chain.
424          */
425         if (get_nulls_value(node) != slot)
426                 goto begin;
427 out:
428         sk = NULL;
429 found:
430         return sk;
431 }
432 EXPORT_SYMBOL_GPL(__inet_lookup_established);
433 
434 /* called with local bh disabled */
435 static int __inet_check_established(struct inet_timewait_death_row *death_row,
436                                     struct sock *sk, __u16 lport,
437                                     struct inet_timewait_sock **twp)
438 {
439         struct inet_hashinfo *hinfo = death_row->hashinfo;
440         struct inet_sock *inet = inet_sk(sk);
441         __be32 daddr = inet->inet_rcv_saddr;
442         __be32 saddr = inet->inet_daddr;
443         int dif = sk->sk_bound_dev_if;
444         struct net *net = sock_net(sk);
445         int sdif = l3mdev_master_ifindex_by_index(net, dif);
446         INET_ADDR_COOKIE(acookie, saddr, daddr);
447         const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
448         unsigned int hash = inet_ehashfn(net, daddr, lport,
449                                          saddr, inet->inet_dport);
450         struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
451         spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
452         struct sock *sk2;
453         const struct hlist_nulls_node *node;
454         struct inet_timewait_sock *tw = NULL;
455 
456         spin_lock(lock);
457 
458         sk_nulls_for_each(sk2, node, &head->chain) {
459                 if (sk2->sk_hash != hash)
460                         continue;
461 
462                 if (likely(INET_MATCH(sk2, net, acookie,
463                                          saddr, daddr, ports, dif, sdif))) {
464                         if (sk2->sk_state == TCP_TIME_WAIT) {
465                                 tw = inet_twsk(sk2);
466                                 if (twsk_unique(sk, sk2, twp))
467                                         break;
468                         }
469                         goto not_unique;
470                 }
471         }
472 
473         /* Must record num and sport now. Otherwise we will see
474          * in hash table socket with a funny identity.
475          */
476         inet->inet_num = lport;
477         inet->inet_sport = htons(lport);
478         sk->sk_hash = hash;
479         WARN_ON(!sk_unhashed(sk));
480         __sk_nulls_add_node_rcu(sk, &head->chain);
481         if (tw) {
482                 sk_nulls_del_node_init_rcu((struct sock *)tw);
483                 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
484         }
485         spin_unlock(lock);
486         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
487 
488         if (twp) {
489                 *twp = tw;
490         } else if (tw) {
491                 /* Silly. Should hash-dance instead... */
492                 inet_twsk_deschedule_put(tw);
493         }
494         return 0;
495 
496 not_unique:
497         spin_unlock(lock);
498         return -EADDRNOTAVAIL;
499 }
500 
501 static u32 inet_sk_port_offset(const struct sock *sk)
502 {
503         const struct inet_sock *inet = inet_sk(sk);
504 
505         return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
506                                           inet->inet_daddr,
507                                           inet->inet_dport);
508 }
509 
510 /* insert a socket into ehash, and eventually remove another one
511  * (The another one can be a SYN_RECV or TIMEWAIT
512  */
513 bool inet_ehash_insert(struct sock *sk, struct sock *osk)
514 {
515         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
516         struct hlist_nulls_head *list;
517         struct inet_ehash_bucket *head;
518         spinlock_t *lock;
519         bool ret = true;
520 
521         WARN_ON_ONCE(!sk_unhashed(sk));
522 
523         sk->sk_hash = sk_ehashfn(sk);
524         head = inet_ehash_bucket(hashinfo, sk->sk_hash);
525         list = &head->chain;
526         lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
527 
528         spin_lock(lock);
529         if (osk) {
530                 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
531                 ret = sk_nulls_del_node_init_rcu(osk);
532         }
533         if (ret)
534                 __sk_nulls_add_node_rcu(sk, list);
535         spin_unlock(lock);
536         return ret;
537 }
538 
539 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk)
540 {
541         bool ok = inet_ehash_insert(sk, osk);
542 
543         if (ok) {
544                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
545         } else {
546                 percpu_counter_inc(sk->sk_prot->orphan_count);
547                 inet_sk_set_state(sk, TCP_CLOSE);
548                 sock_set_flag(sk, SOCK_DEAD);
549                 inet_csk_destroy_sock(sk);
550         }
551         return ok;
552 }
553 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
554 
555 static int inet_reuseport_add_sock(struct sock *sk,
556                                    struct inet_listen_hashbucket *ilb)
557 {
558         struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
559         struct sock *sk2;
560         kuid_t uid = sock_i_uid(sk);
561 
562         sk_for_each_rcu(sk2, &ilb->head) {
563                 if (sk2 != sk &&
564                     sk2->sk_family == sk->sk_family &&
565                     ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
566                     sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
567                     inet_csk(sk2)->icsk_bind_hash == tb &&
568                     sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
569                     inet_rcv_saddr_equal(sk, sk2, false))
570                         return reuseport_add_sock(sk, sk2);
571         }
572 
573         return reuseport_alloc(sk);
574 }
575 
576 int __inet_hash(struct sock *sk, struct sock *osk)
577 {
578         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
579         struct inet_listen_hashbucket *ilb;
580         int err = 0;
581 
582         if (sk->sk_state != TCP_LISTEN) {
583                 inet_ehash_nolisten(sk, osk);
584                 return 0;
585         }
586         WARN_ON(!sk_unhashed(sk));
587         ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
588 
589         spin_lock(&ilb->lock);
590         if (sk->sk_reuseport) {
591                 err = inet_reuseport_add_sock(sk, ilb);
592                 if (err)
593                         goto unlock;
594         }
595         if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
596                 sk->sk_family == AF_INET6)
597                 hlist_add_tail_rcu(&sk->sk_node, &ilb->head);
598         else
599                 hlist_add_head_rcu(&sk->sk_node, &ilb->head);
600         inet_hash2(hashinfo, sk);
601         ilb->count++;
602         sock_set_flag(sk, SOCK_RCU_FREE);
603         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
604 unlock:
605         spin_unlock(&ilb->lock);
606 
607         return err;
608 }
609 EXPORT_SYMBOL(__inet_hash);
610 
611 int inet_hash(struct sock *sk)
612 {
613         int err = 0;
614 
615         if (sk->sk_state != TCP_CLOSE) {
616                 local_bh_disable();
617                 err = __inet_hash(sk, NULL);
618                 local_bh_enable();
619         }
620 
621         return err;
622 }
623 EXPORT_SYMBOL_GPL(inet_hash);
624 
625 void inet_unhash(struct sock *sk)
626 {
627         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
628         struct inet_listen_hashbucket *ilb = NULL;
629         spinlock_t *lock;
630 
631         if (sk_unhashed(sk))
632                 return;
633 
634         if (sk->sk_state == TCP_LISTEN) {
635                 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
636                 lock = &ilb->lock;
637         } else {
638                 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
639         }
640         spin_lock_bh(lock);
641         if (sk_unhashed(sk))
642                 goto unlock;
643 
644         if (rcu_access_pointer(sk->sk_reuseport_cb))
645                 reuseport_detach_sock(sk);
646         if (ilb) {
647                 inet_unhash2(hashinfo, sk);
648                  __sk_del_node_init(sk);
649                  ilb->count--;
650         } else {
651                 __sk_nulls_del_node_init_rcu(sk);
652         }
653         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
654 unlock:
655         spin_unlock_bh(lock);
656 }
657 EXPORT_SYMBOL_GPL(inet_unhash);
658 
659 int __inet_hash_connect(struct inet_timewait_death_row *death_row,
660                 struct sock *sk, u32 port_offset,
661                 int (*check_established)(struct inet_timewait_death_row *,
662                         struct sock *, __u16, struct inet_timewait_sock **))
663 {
664         struct inet_hashinfo *hinfo = death_row->hashinfo;
665         struct inet_timewait_sock *tw = NULL;
666         struct inet_bind_hashbucket *head;
667         int port = inet_sk(sk)->inet_num;
668         struct net *net = sock_net(sk);
669         struct inet_bind_bucket *tb;
670         u32 remaining, offset;
671         int ret, i, low, high;
672         static u32 hint;
673 
674         if (port) {
675                 head = &hinfo->bhash[inet_bhashfn(net, port,
676                                                   hinfo->bhash_size)];
677                 tb = inet_csk(sk)->icsk_bind_hash;
678                 spin_lock_bh(&head->lock);
679                 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
680                         inet_ehash_nolisten(sk, NULL);
681                         spin_unlock_bh(&head->lock);
682                         return 0;
683                 }
684                 spin_unlock(&head->lock);
685                 /* No definite answer... Walk to established hash table */
686                 ret = check_established(death_row, sk, port, NULL);
687                 local_bh_enable();
688                 return ret;
689         }
690 
691         inet_get_local_port_range(net, &low, &high);
692         high++; /* [32768, 60999] -> [32768, 61000[ */
693         remaining = high - low;
694         if (likely(remaining > 1))
695                 remaining &= ~1U;
696 
697         offset = (hint + port_offset) % remaining;
698         /* In first pass we try ports of @low parity.
699          * inet_csk_get_port() does the opposite choice.
700          */
701         offset &= ~1U;
702 other_parity_scan:
703         port = low + offset;
704         for (i = 0; i < remaining; i += 2, port += 2) {
705                 if (unlikely(port >= high))
706                         port -= remaining;
707                 if (inet_is_local_reserved_port(net, port))
708                         continue;
709                 head = &hinfo->bhash[inet_bhashfn(net, port,
710                                                   hinfo->bhash_size)];
711                 spin_lock_bh(&head->lock);
712 
713                 /* Does not bother with rcv_saddr checks, because
714                  * the established check is already unique enough.
715                  */
716                 inet_bind_bucket_for_each(tb, &head->chain) {
717                         if (net_eq(ib_net(tb), net) && tb->port == port) {
718                                 if (tb->fastreuse >= 0 ||
719                                     tb->fastreuseport >= 0)
720                                         goto next_port;
721                                 WARN_ON(hlist_empty(&tb->owners));
722                                 if (!check_established(death_row, sk,
723                                                        port, &tw))
724                                         goto ok;
725                                 goto next_port;
726                         }
727                 }
728 
729                 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
730                                              net, head, port);
731                 if (!tb) {
732                         spin_unlock_bh(&head->lock);
733                         return -ENOMEM;
734                 }
735                 tb->fastreuse = -1;
736                 tb->fastreuseport = -1;
737                 goto ok;
738 next_port:
739                 spin_unlock_bh(&head->lock);
740                 cond_resched();
741         }
742 
743         offset++;
744         if ((offset & 1) && remaining > 1)
745                 goto other_parity_scan;
746 
747         return -EADDRNOTAVAIL;
748 
749 ok:
750         hint += i + 2;
751 
752         /* Head lock still held and bh's disabled */
753         inet_bind_hash(sk, tb, port);
754         if (sk_unhashed(sk)) {
755                 inet_sk(sk)->inet_sport = htons(port);
756                 inet_ehash_nolisten(sk, (struct sock *)tw);
757         }
758         if (tw)
759                 inet_twsk_bind_unhash(tw, hinfo);
760         spin_unlock(&head->lock);
761         if (tw)
762                 inet_twsk_deschedule_put(tw);
763         local_bh_enable();
764         return 0;
765 }
766 
767 /*
768  * Bind a port for a connect operation and hash it.
769  */
770 int inet_hash_connect(struct inet_timewait_death_row *death_row,
771                       struct sock *sk)
772 {
773         u32 port_offset = 0;
774 
775         if (!inet_sk(sk)->inet_num)
776                 port_offset = inet_sk_port_offset(sk);
777         return __inet_hash_connect(death_row, sk, port_offset,
778                                    __inet_check_established);
779 }
780 EXPORT_SYMBOL_GPL(inet_hash_connect);
781 
782 void inet_hashinfo_init(struct inet_hashinfo *h)
783 {
784         int i;
785 
786         for (i = 0; i < INET_LHTABLE_SIZE; i++) {
787                 spin_lock_init(&h->listening_hash[i].lock);
788                 INIT_HLIST_HEAD(&h->listening_hash[i].head);
789                 h->listening_hash[i].count = 0;
790         }
791 
792         h->lhash2 = NULL;
793 }
794 EXPORT_SYMBOL_GPL(inet_hashinfo_init);
795 
796 void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
797                                 unsigned long numentries, int scale,
798                                 unsigned long low_limit,
799                                 unsigned long high_limit)
800 {
801         unsigned int i;
802 
803         h->lhash2 = alloc_large_system_hash(name,
804                                             sizeof(*h->lhash2),
805                                             numentries,
806                                             scale,
807                                             0,
808                                             NULL,
809                                             &h->lhash2_mask,
810                                             low_limit,
811                                             high_limit);
812 
813         for (i = 0; i <= h->lhash2_mask; i++) {
814                 spin_lock_init(&h->lhash2[i].lock);
815                 INIT_HLIST_HEAD(&h->lhash2[i].head);
816                 h->lhash2[i].count = 0;
817         }
818 }
819 
820 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
821 {
822         unsigned int locksz = sizeof(spinlock_t);
823         unsigned int i, nblocks = 1;
824 
825         if (locksz != 0) {
826                 /* allocate 2 cache lines or at least one spinlock per cpu */
827                 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
828                 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
829 
830                 /* no more locks than number of hash buckets */
831                 nblocks = min(nblocks, hashinfo->ehash_mask + 1);
832 
833                 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL);
834                 if (!hashinfo->ehash_locks)
835                         return -ENOMEM;
836 
837                 for (i = 0; i < nblocks; i++)
838                         spin_lock_init(&hashinfo->ehash_locks[i]);
839         }
840         hashinfo->ehash_locks_mask = nblocks - 1;
841         return 0;
842 }
843 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);
844 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp