1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Generic INET transport hashtables
8 *
9 * Authors: Lotsa people, from code originally in tcp
10 */
11
12 #include <linux/module.h>
13 #include <linux/random.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
16 #include <linux/wait.h>
17 #include <linux/vmalloc.h>
18 #include <linux/memblock.h>
19
20 #include <net/addrconf.h>
21 #include <net/inet_connection_sock.h>
22 #include <net/inet_hashtables.h>
23 #include <net/secure_seq.h>
24 #include <net/ip.h>
25 #include <net/tcp.h>
26 #include <net/sock_reuseport.h>
27
inet_ehashfn(const struct net * net,const __be32 laddr,const __u16 lport,const __be32 faddr,const __be16 fport)28 static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
29 const __u16 lport, const __be32 faddr,
30 const __be16 fport)
31 {
32 static u32 inet_ehash_secret __read_mostly;
33
34 net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret));
35
36 return __inet_ehashfn(laddr, lport, faddr, fport,
37 inet_ehash_secret + net_hash_mix(net));
38 }
39
40 /* This function handles inet_sock, but also timewait and request sockets
41 * for IPv4/IPv6.
42 */
sk_ehashfn(const struct sock * sk)43 static u32 sk_ehashfn(const struct sock *sk)
44 {
45 #if IS_ENABLED(CONFIG_IPV6)
46 if (sk->sk_family == AF_INET6 &&
47 !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
48 return inet6_ehashfn(sock_net(sk),
49 &sk->sk_v6_rcv_saddr, sk->sk_num,
50 &sk->sk_v6_daddr, sk->sk_dport);
51 #endif
52 return inet_ehashfn(sock_net(sk),
53 sk->sk_rcv_saddr, sk->sk_num,
54 sk->sk_daddr, sk->sk_dport);
55 }
56
57 /*
58 * Allocate and initialize a new local port bind bucket.
59 * The bindhash mutex for snum's hash chain must be held here.
60 */
inet_bind_bucket_create(struct kmem_cache * cachep,struct net * net,struct inet_bind_hashbucket * head,const unsigned short snum,int l3mdev)61 struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
62 struct net *net,
63 struct inet_bind_hashbucket *head,
64 const unsigned short snum,
65 int l3mdev)
66 {
67 struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
68
69 if (tb) {
70 write_pnet(&tb->ib_net, net);
71 tb->l3mdev = l3mdev;
72 tb->port = snum;
73 tb->fastreuse = 0;
74 tb->fastreuseport = 0;
75 INIT_HLIST_HEAD(&tb->owners);
76 hlist_add_head(&tb->node, &head->chain);
77 }
78 return tb;
79 }
80
81 /*
82 * Caller must hold hashbucket lock for this tb with local BH disabled
83 */
inet_bind_bucket_destroy(struct kmem_cache * cachep,struct inet_bind_bucket * tb)84 void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
85 {
86 if (hlist_empty(&tb->owners)) {
87 __hlist_del(&tb->node);
88 kmem_cache_free(cachep, tb);
89 }
90 }
91
inet_bind_hash(struct sock * sk,struct inet_bind_bucket * tb,const unsigned short snum)92 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
93 const unsigned short snum)
94 {
95 inet_sk(sk)->inet_num = snum;
96 sk_add_bind_node(sk, &tb->owners);
97 inet_csk(sk)->icsk_bind_hash = tb;
98 }
99
100 /*
101 * Get rid of any references to a local port held by the given sock.
102 */
__inet_put_port(struct sock * sk)103 static void __inet_put_port(struct sock *sk)
104 {
105 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
106 const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num,
107 hashinfo->bhash_size);
108 struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
109 struct inet_bind_bucket *tb;
110
111 spin_lock(&head->lock);
112 tb = inet_csk(sk)->icsk_bind_hash;
113 __sk_del_bind_node(sk);
114 inet_csk(sk)->icsk_bind_hash = NULL;
115 inet_sk(sk)->inet_num = 0;
116 inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
117 spin_unlock(&head->lock);
118 }
119
inet_put_port(struct sock * sk)120 void inet_put_port(struct sock *sk)
121 {
122 local_bh_disable();
123 __inet_put_port(sk);
124 local_bh_enable();
125 }
126 EXPORT_SYMBOL(inet_put_port);
127
__inet_inherit_port(const struct sock * sk,struct sock * child)128 int __inet_inherit_port(const struct sock *sk, struct sock *child)
129 {
130 struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
131 unsigned short port = inet_sk(child)->inet_num;
132 const int bhash = inet_bhashfn(sock_net(sk), port,
133 table->bhash_size);
134 struct inet_bind_hashbucket *head = &table->bhash[bhash];
135 struct inet_bind_bucket *tb;
136 int l3mdev;
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 l3mdev = inet_sk_bound_l3mdev(sk);
146
147 /* NOTE: using tproxy and redirecting skbs to a proxy
148 * on a different listener port breaks the assumption
149 * that the listener socket's icsk_bind_hash is the same
150 * as that of the child socket. We have to look up or
151 * create a new bind bucket for the child here. */
152 inet_bind_bucket_for_each(tb, &head->chain) {
153 if (net_eq(ib_net(tb), sock_net(sk)) &&
154 tb->l3mdev == l3mdev && tb->port == port)
155 break;
156 }
157 if (!tb) {
158 tb = inet_bind_bucket_create(table->bind_bucket_cachep,
159 sock_net(sk), head, port,
160 l3mdev);
161 if (!tb) {
162 spin_unlock(&head->lock);
163 return -ENOMEM;
164 }
165 }
166 }
167 inet_bind_hash(child, tb, port);
168 spin_unlock(&head->lock);
169
170 return 0;
171 }
172 EXPORT_SYMBOL_GPL(__inet_inherit_port);
173
174 static struct inet_listen_hashbucket *
inet_lhash2_bucket_sk(struct inet_hashinfo * h,struct sock * sk)175 inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk)
176 {
177 u32 hash;
178
179 #if IS_ENABLED(CONFIG_IPV6)
180 if (sk->sk_family == AF_INET6)
181 hash = ipv6_portaddr_hash(sock_net(sk),
182 &sk->sk_v6_rcv_saddr,
183 inet_sk(sk)->inet_num);
184 else
185 #endif
186 hash = ipv4_portaddr_hash(sock_net(sk),
187 inet_sk(sk)->inet_rcv_saddr,
188 inet_sk(sk)->inet_num);
189 return inet_lhash2_bucket(h, hash);
190 }
191
inet_hash2(struct inet_hashinfo * h,struct sock * sk)192 static void inet_hash2(struct inet_hashinfo *h, struct sock *sk)
193 {
194 struct inet_listen_hashbucket *ilb2;
195
196 if (!h->lhash2)
197 return;
198
199 ilb2 = inet_lhash2_bucket_sk(h, sk);
200
201 spin_lock(&ilb2->lock);
202 if (sk->sk_reuseport && sk->sk_family == AF_INET6)
203 hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,
204 &ilb2->head);
205 else
206 hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node,
207 &ilb2->head);
208 ilb2->count++;
209 spin_unlock(&ilb2->lock);
210 }
211
inet_unhash2(struct inet_hashinfo * h,struct sock * sk)212 static void inet_unhash2(struct inet_hashinfo *h, struct sock *sk)
213 {
214 struct inet_listen_hashbucket *ilb2;
215
216 if (!h->lhash2 ||
217 WARN_ON_ONCE(hlist_unhashed(&inet_csk(sk)->icsk_listen_portaddr_node)))
218 return;
219
220 ilb2 = inet_lhash2_bucket_sk(h, sk);
221
222 spin_lock(&ilb2->lock);
223 hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node);
224 ilb2->count--;
225 spin_unlock(&ilb2->lock);
226 }
227
compute_score(struct sock * sk,struct net * net,const unsigned short hnum,const __be32 daddr,const int dif,const int sdif,bool exact_dif)228 static inline int compute_score(struct sock *sk, struct net *net,
229 const unsigned short hnum, const __be32 daddr,
230 const int dif, const int sdif, bool exact_dif)
231 {
232 int score = -1;
233
234 if (net_eq(sock_net(sk), net) && sk->sk_num == hnum &&
235 !ipv6_only_sock(sk)) {
236 if (sk->sk_rcv_saddr != daddr)
237 return -1;
238
239 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
240 return -1;
241
242 score = sk->sk_family == PF_INET ? 2 : 1;
243 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
244 score++;
245 }
246 return score;
247 }
248
249 /*
250 * Here are some nice properties to exploit here. The BSD API
251 * does not allow a listening sock to specify the remote port nor the
252 * remote address for the connection. So always assume those are both
253 * wildcarded during the search since they can never be otherwise.
254 */
255
256 /* called with rcu_read_lock() : No refcount taken on the socket */
inet_lhash2_lookup(struct net * net,struct inet_listen_hashbucket * ilb2,struct sk_buff * skb,int doff,const __be32 saddr,__be16 sport,const __be32 daddr,const unsigned short hnum,const int dif,const int sdif)257 static struct sock *inet_lhash2_lookup(struct net *net,
258 struct inet_listen_hashbucket *ilb2,
259 struct sk_buff *skb, int doff,
260 const __be32 saddr, __be16 sport,
261 const __be32 daddr, const unsigned short hnum,
262 const int dif, const int sdif)
263 {
264 bool exact_dif = inet_exact_dif_match(net, skb);
265 struct inet_connection_sock *icsk;
266 struct sock *sk, *result = NULL;
267 int score, hiscore = 0;
268 u32 phash = 0;
269
270 inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
271 sk = (struct sock *)icsk;
272 score = compute_score(sk, net, hnum, daddr,
273 dif, sdif, exact_dif);
274 if (score > hiscore) {
275 if (sk->sk_reuseport) {
276 phash = inet_ehashfn(net, daddr, hnum,
277 saddr, sport);
278 result = reuseport_select_sock(sk, phash,
279 skb, doff);
280 if (result)
281 return result;
282 }
283 result = sk;
284 hiscore = score;
285 }
286 }
287
288 return result;
289 }
290
__inet_lookup_listener(struct net * net,struct inet_hashinfo * hashinfo,struct sk_buff * skb,int doff,const __be32 saddr,__be16 sport,const __be32 daddr,const unsigned short hnum,const int dif,const int sdif)291 struct sock *__inet_lookup_listener(struct net *net,
292 struct inet_hashinfo *hashinfo,
293 struct sk_buff *skb, int doff,
294 const __be32 saddr, __be16 sport,
295 const __be32 daddr, const unsigned short hnum,
296 const int dif, const int sdif)
297 {
298 struct inet_listen_hashbucket *ilb2;
299 struct sock *result = NULL;
300 unsigned int hash2;
301
302 hash2 = ipv4_portaddr_hash(net, daddr, hnum);
303 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
304
305 result = inet_lhash2_lookup(net, ilb2, skb, doff,
306 saddr, sport, daddr, hnum,
307 dif, sdif);
308 if (result)
309 goto done;
310
311 /* Lookup lhash2 with INADDR_ANY */
312 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
313 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
314
315 result = inet_lhash2_lookup(net, ilb2, skb, doff,
316 saddr, sport, htonl(INADDR_ANY), hnum,
317 dif, sdif);
318 done:
319 if (IS_ERR(result))
320 return NULL;
321 return result;
322 }
323 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
324
325 /* All sockets share common refcount, but have different destructors */
sock_gen_put(struct sock * sk)326 void sock_gen_put(struct sock *sk)
327 {
328 if (!refcount_dec_and_test(&sk->sk_refcnt))
329 return;
330
331 if (sk->sk_state == TCP_TIME_WAIT)
332 inet_twsk_free(inet_twsk(sk));
333 else if (sk->sk_state == TCP_NEW_SYN_RECV)
334 reqsk_free(inet_reqsk(sk));
335 else
336 sk_free(sk);
337 }
338 EXPORT_SYMBOL_GPL(sock_gen_put);
339
sock_edemux(struct sk_buff * skb)340 void sock_edemux(struct sk_buff *skb)
341 {
342 sock_gen_put(skb->sk);
343 }
344 EXPORT_SYMBOL(sock_edemux);
345
__inet_lookup_established(struct net * net,struct inet_hashinfo * hashinfo,const __be32 saddr,const __be16 sport,const __be32 daddr,const u16 hnum,const int dif,const int sdif)346 struct sock *__inet_lookup_established(struct net *net,
347 struct inet_hashinfo *hashinfo,
348 const __be32 saddr, const __be16 sport,
349 const __be32 daddr, const u16 hnum,
350 const int dif, const int sdif)
351 {
352 INET_ADDR_COOKIE(acookie, saddr, daddr);
353 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
354 struct sock *sk;
355 const struct hlist_nulls_node *node;
356 /* Optimize here for direct hit, only listening connections can
357 * have wildcards anyways.
358 */
359 unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
360 unsigned int slot = hash & hashinfo->ehash_mask;
361 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
362
363 begin:
364 sk_nulls_for_each_rcu(sk, node, &head->chain) {
365 if (sk->sk_hash != hash)
366 continue;
367 if (likely(INET_MATCH(sk, net, acookie,
368 saddr, daddr, ports, dif, sdif))) {
369 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
370 goto out;
371 if (unlikely(!INET_MATCH(sk, net, acookie,
372 saddr, daddr, ports,
373 dif, sdif))) {
374 sock_gen_put(sk);
375 goto begin;
376 }
377 goto found;
378 }
379 }
380 /*
381 * if the nulls value we got at the end of this lookup is
382 * not the expected one, we must restart lookup.
383 * We probably met an item that was moved to another chain.
384 */
385 if (get_nulls_value(node) != slot)
386 goto begin;
387 out:
388 sk = NULL;
389 found:
390 return sk;
391 }
392 EXPORT_SYMBOL_GPL(__inet_lookup_established);
393
394 /* called with local bh disabled */
__inet_check_established(struct inet_timewait_death_row * death_row,struct sock * sk,__u16 lport,struct inet_timewait_sock ** twp)395 static int __inet_check_established(struct inet_timewait_death_row *death_row,
396 struct sock *sk, __u16 lport,
397 struct inet_timewait_sock **twp)
398 {
399 struct inet_hashinfo *hinfo = death_row->hashinfo;
400 struct inet_sock *inet = inet_sk(sk);
401 __be32 daddr = inet->inet_rcv_saddr;
402 __be32 saddr = inet->inet_daddr;
403 int dif = sk->sk_bound_dev_if;
404 struct net *net = sock_net(sk);
405 int sdif = l3mdev_master_ifindex_by_index(net, dif);
406 INET_ADDR_COOKIE(acookie, saddr, daddr);
407 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
408 unsigned int hash = inet_ehashfn(net, daddr, lport,
409 saddr, inet->inet_dport);
410 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
411 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
412 struct sock *sk2;
413 const struct hlist_nulls_node *node;
414 struct inet_timewait_sock *tw = NULL;
415
416 spin_lock(lock);
417
418 sk_nulls_for_each(sk2, node, &head->chain) {
419 if (sk2->sk_hash != hash)
420 continue;
421
422 if (likely(INET_MATCH(sk2, net, acookie,
423 saddr, daddr, ports, dif, sdif))) {
424 if (sk2->sk_state == TCP_TIME_WAIT) {
425 tw = inet_twsk(sk2);
426 if (twsk_unique(sk, sk2, twp))
427 break;
428 }
429 goto not_unique;
430 }
431 }
432
433 /* Must record num and sport now. Otherwise we will see
434 * in hash table socket with a funny identity.
435 */
436 inet->inet_num = lport;
437 inet->inet_sport = htons(lport);
438 sk->sk_hash = hash;
439 WARN_ON(!sk_unhashed(sk));
440 __sk_nulls_add_node_rcu(sk, &head->chain);
441 if (tw) {
442 sk_nulls_del_node_init_rcu((struct sock *)tw);
443 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
444 }
445 spin_unlock(lock);
446 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
447
448 if (twp) {
449 *twp = tw;
450 } else if (tw) {
451 /* Silly. Should hash-dance instead... */
452 inet_twsk_deschedule_put(tw);
453 }
454 return 0;
455
456 not_unique:
457 spin_unlock(lock);
458 return -EADDRNOTAVAIL;
459 }
460
inet_sk_port_offset(const struct sock * sk)461 static u32 inet_sk_port_offset(const struct sock *sk)
462 {
463 const struct inet_sock *inet = inet_sk(sk);
464
465 return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
466 inet->inet_daddr,
467 inet->inet_dport);
468 }
469
470 /* insert a socket into ehash, and eventually remove another one
471 * (The another one can be a SYN_RECV or TIMEWAIT
472 */
inet_ehash_insert(struct sock * sk,struct sock * osk)473 bool inet_ehash_insert(struct sock *sk, struct sock *osk)
474 {
475 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
476 struct hlist_nulls_head *list;
477 struct inet_ehash_bucket *head;
478 spinlock_t *lock;
479 bool ret = true;
480
481 WARN_ON_ONCE(!sk_unhashed(sk));
482
483 sk->sk_hash = sk_ehashfn(sk);
484 head = inet_ehash_bucket(hashinfo, sk->sk_hash);
485 list = &head->chain;
486 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
487
488 spin_lock(lock);
489 if (osk) {
490 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
491 ret = sk_nulls_del_node_init_rcu(osk);
492 }
493 if (ret)
494 __sk_nulls_add_node_rcu(sk, list);
495 spin_unlock(lock);
496 return ret;
497 }
498
inet_ehash_nolisten(struct sock * sk,struct sock * osk)499 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk)
500 {
501 bool ok = inet_ehash_insert(sk, osk);
502
503 if (ok) {
504 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
505 } else {
506 percpu_counter_inc(sk->sk_prot->orphan_count);
507 inet_sk_set_state(sk, TCP_CLOSE);
508 sock_set_flag(sk, SOCK_DEAD);
509 inet_csk_destroy_sock(sk);
510 }
511 return ok;
512 }
513 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
514
inet_reuseport_add_sock(struct sock * sk,struct inet_listen_hashbucket * ilb)515 static int inet_reuseport_add_sock(struct sock *sk,
516 struct inet_listen_hashbucket *ilb)
517 {
518 struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
519 const struct hlist_nulls_node *node;
520 struct sock *sk2;
521 kuid_t uid = sock_i_uid(sk);
522
523 sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) {
524 if (sk2 != sk &&
525 sk2->sk_family == sk->sk_family &&
526 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
527 sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
528 inet_csk(sk2)->icsk_bind_hash == tb &&
529 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
530 inet_rcv_saddr_equal(sk, sk2, false))
531 return reuseport_add_sock(sk, sk2,
532 inet_rcv_saddr_any(sk));
533 }
534
535 return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
536 }
537
__inet_hash(struct sock * sk,struct sock * osk)538 int __inet_hash(struct sock *sk, struct sock *osk)
539 {
540 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
541 struct inet_listen_hashbucket *ilb;
542 int err = 0;
543
544 if (sk->sk_state != TCP_LISTEN) {
545 inet_ehash_nolisten(sk, osk);
546 return 0;
547 }
548 WARN_ON(!sk_unhashed(sk));
549 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
550
551 spin_lock(&ilb->lock);
552 if (sk->sk_reuseport) {
553 err = inet_reuseport_add_sock(sk, ilb);
554 if (err)
555 goto unlock;
556 }
557 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
558 sk->sk_family == AF_INET6)
559 __sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head);
560 else
561 __sk_nulls_add_node_rcu(sk, &ilb->nulls_head);
562 inet_hash2(hashinfo, sk);
563 ilb->count++;
564 sock_set_flag(sk, SOCK_RCU_FREE);
565 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
566 unlock:
567 spin_unlock(&ilb->lock);
568
569 return err;
570 }
571 EXPORT_SYMBOL(__inet_hash);
572
inet_hash(struct sock * sk)573 int inet_hash(struct sock *sk)
574 {
575 int err = 0;
576
577 if (sk->sk_state != TCP_CLOSE) {
578 local_bh_disable();
579 err = __inet_hash(sk, NULL);
580 local_bh_enable();
581 }
582
583 return err;
584 }
585 EXPORT_SYMBOL_GPL(inet_hash);
586
inet_unhash(struct sock * sk)587 void inet_unhash(struct sock *sk)
588 {
589 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
590 struct inet_listen_hashbucket *ilb = NULL;
591 spinlock_t *lock;
592
593 if (sk_unhashed(sk))
594 return;
595
596 if (sk->sk_state == TCP_LISTEN) {
597 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
598 lock = &ilb->lock;
599 } else {
600 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
601 }
602 spin_lock_bh(lock);
603 if (sk_unhashed(sk))
604 goto unlock;
605
606 if (rcu_access_pointer(sk->sk_reuseport_cb))
607 reuseport_detach_sock(sk);
608 if (ilb) {
609 inet_unhash2(hashinfo, sk);
610 ilb->count--;
611 }
612 __sk_nulls_del_node_init_rcu(sk);
613 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
614 unlock:
615 spin_unlock_bh(lock);
616 }
617 EXPORT_SYMBOL_GPL(inet_unhash);
618
__inet_hash_connect(struct inet_timewait_death_row * death_row,struct sock * sk,u32 port_offset,int (* check_established)(struct inet_timewait_death_row *,struct sock *,__u16,struct inet_timewait_sock **))619 int __inet_hash_connect(struct inet_timewait_death_row *death_row,
620 struct sock *sk, u32 port_offset,
621 int (*check_established)(struct inet_timewait_death_row *,
622 struct sock *, __u16, struct inet_timewait_sock **))
623 {
624 struct inet_hashinfo *hinfo = death_row->hashinfo;
625 struct inet_timewait_sock *tw = NULL;
626 struct inet_bind_hashbucket *head;
627 int port = inet_sk(sk)->inet_num;
628 struct net *net = sock_net(sk);
629 struct inet_bind_bucket *tb;
630 u32 remaining, offset;
631 int ret, i, low, high;
632 static u32 hint;
633 int l3mdev;
634
635 if (port) {
636 head = &hinfo->bhash[inet_bhashfn(net, port,
637 hinfo->bhash_size)];
638 tb = inet_csk(sk)->icsk_bind_hash;
639 spin_lock_bh(&head->lock);
640 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
641 inet_ehash_nolisten(sk, NULL);
642 spin_unlock_bh(&head->lock);
643 return 0;
644 }
645 spin_unlock(&head->lock);
646 /* No definite answer... Walk to established hash table */
647 ret = check_established(death_row, sk, port, NULL);
648 local_bh_enable();
649 return ret;
650 }
651
652 l3mdev = inet_sk_bound_l3mdev(sk);
653
654 inet_get_local_port_range(net, &low, &high);
655 high++; /* [32768, 60999] -> [32768, 61000[ */
656 remaining = high - low;
657 if (likely(remaining > 1))
658 remaining &= ~1U;
659
660 offset = (hint + port_offset) % remaining;
661 /* In first pass we try ports of @low parity.
662 * inet_csk_get_port() does the opposite choice.
663 */
664 offset &= ~1U;
665 other_parity_scan:
666 port = low + offset;
667 for (i = 0; i < remaining; i += 2, port += 2) {
668 if (unlikely(port >= high))
669 port -= remaining;
670 if (inet_is_local_reserved_port(net, port))
671 continue;
672 head = &hinfo->bhash[inet_bhashfn(net, port,
673 hinfo->bhash_size)];
674 spin_lock_bh(&head->lock);
675
676 /* Does not bother with rcv_saddr checks, because
677 * the established check is already unique enough.
678 */
679 inet_bind_bucket_for_each(tb, &head->chain) {
680 if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev &&
681 tb->port == port) {
682 if (tb->fastreuse >= 0 ||
683 tb->fastreuseport >= 0)
684 goto next_port;
685 WARN_ON(hlist_empty(&tb->owners));
686 if (!check_established(death_row, sk,
687 port, &tw))
688 goto ok;
689 goto next_port;
690 }
691 }
692
693 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
694 net, head, port, l3mdev);
695 if (!tb) {
696 spin_unlock_bh(&head->lock);
697 return -ENOMEM;
698 }
699 tb->fastreuse = -1;
700 tb->fastreuseport = -1;
701 goto ok;
702 next_port:
703 spin_unlock_bh(&head->lock);
704 cond_resched();
705 }
706
707 offset++;
708 if ((offset & 1) && remaining > 1)
709 goto other_parity_scan;
710
711 return -EADDRNOTAVAIL;
712
713 ok:
714 hint += i + 2;
715
716 /* Head lock still held and bh's disabled */
717 inet_bind_hash(sk, tb, port);
718 if (sk_unhashed(sk)) {
719 inet_sk(sk)->inet_sport = htons(port);
720 inet_ehash_nolisten(sk, (struct sock *)tw);
721 }
722 if (tw)
723 inet_twsk_bind_unhash(tw, hinfo);
724 spin_unlock(&head->lock);
725 if (tw)
726 inet_twsk_deschedule_put(tw);
727 local_bh_enable();
728 return 0;
729 }
730
731 /*
732 * Bind a port for a connect operation and hash it.
733 */
inet_hash_connect(struct inet_timewait_death_row * death_row,struct sock * sk)734 int inet_hash_connect(struct inet_timewait_death_row *death_row,
735 struct sock *sk)
736 {
737 u32 port_offset = 0;
738
739 if (!inet_sk(sk)->inet_num)
740 port_offset = inet_sk_port_offset(sk);
741 return __inet_hash_connect(death_row, sk, port_offset,
742 __inet_check_established);
743 }
744 EXPORT_SYMBOL_GPL(inet_hash_connect);
745
inet_hashinfo_init(struct inet_hashinfo * h)746 void inet_hashinfo_init(struct inet_hashinfo *h)
747 {
748 int i;
749
750 for (i = 0; i < INET_LHTABLE_SIZE; i++) {
751 spin_lock_init(&h->listening_hash[i].lock);
752 INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].nulls_head,
753 i + LISTENING_NULLS_BASE);
754 h->listening_hash[i].count = 0;
755 }
756
757 h->lhash2 = NULL;
758 }
759 EXPORT_SYMBOL_GPL(inet_hashinfo_init);
760
init_hashinfo_lhash2(struct inet_hashinfo * h)761 static void init_hashinfo_lhash2(struct inet_hashinfo *h)
762 {
763 int i;
764
765 for (i = 0; i <= h->lhash2_mask; i++) {
766 spin_lock_init(&h->lhash2[i].lock);
767 INIT_HLIST_HEAD(&h->lhash2[i].head);
768 h->lhash2[i].count = 0;
769 }
770 }
771
inet_hashinfo2_init(struct inet_hashinfo * h,const char * name,unsigned long numentries,int scale,unsigned long low_limit,unsigned long high_limit)772 void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
773 unsigned long numentries, int scale,
774 unsigned long low_limit,
775 unsigned long high_limit)
776 {
777 h->lhash2 = alloc_large_system_hash(name,
778 sizeof(*h->lhash2),
779 numentries,
780 scale,
781 0,
782 NULL,
783 &h->lhash2_mask,
784 low_limit,
785 high_limit);
786 init_hashinfo_lhash2(h);
787 }
788
inet_hashinfo2_init_mod(struct inet_hashinfo * h)789 int inet_hashinfo2_init_mod(struct inet_hashinfo *h)
790 {
791 h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL);
792 if (!h->lhash2)
793 return -ENOMEM;
794
795 h->lhash2_mask = INET_LHTABLE_SIZE - 1;
796 /* INET_LHTABLE_SIZE must be a power of 2 */
797 BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask);
798
799 init_hashinfo_lhash2(h);
800 return 0;
801 }
802 EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod);
803
inet_ehash_locks_alloc(struct inet_hashinfo * hashinfo)804 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
805 {
806 unsigned int locksz = sizeof(spinlock_t);
807 unsigned int i, nblocks = 1;
808
809 if (locksz != 0) {
810 /* allocate 2 cache lines or at least one spinlock per cpu */
811 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
812 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
813
814 /* no more locks than number of hash buckets */
815 nblocks = min(nblocks, hashinfo->ehash_mask + 1);
816
817 hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL);
818 if (!hashinfo->ehash_locks)
819 return -ENOMEM;
820
821 for (i = 0; i < nblocks; i++)
822 spin_lock_init(&hashinfo->ehash_locks[i]);
823 }
824 hashinfo->ehash_locks_mask = nblocks - 1;
825 return 0;
826 }
827 EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);
828