-
Notifications
You must be signed in to change notification settings - Fork 55k
/
Copy pathinet_connection_sock.c
1598 lines (1377 loc) · 43.4 KB
/
inet_connection_sock.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Support for INET connection oriented protocols.
*
* Authors: See the TCP sources
*/
#include <linux/module.h>
#include <linux/jhash.h>
#include <net/inet_connection_sock.h>
#include <net/inet_hashtables.h>
#include <net/inet_timewait_sock.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/tcp_states.h>
#include <net/xfrm.h>
#include <net/tcp.h>
#include <net/sock_reuseport.h>
#include <net/addrconf.h>
#if IS_ENABLED(CONFIG_IPV6)
/* match_sk*_wildcard == true: IPV6_ADDR_ANY equals to any IPv6 addresses
* if IPv6 only, and any IPv4 addresses
* if not IPv6 only
* match_sk*_wildcard == false: addresses must be exactly the same, i.e.
* IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
* and 0.0.0.0 equals to 0.0.0.0 only
*/
static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6,
const struct in6_addr *sk2_rcv_saddr6,
__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
bool sk1_ipv6only, bool sk2_ipv6only,
bool match_sk1_wildcard,
bool match_sk2_wildcard)
{
int addr_type = ipv6_addr_type(sk1_rcv_saddr6);
int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
/* if both are mapped, treat as IPv4 */
if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
if (!sk2_ipv6only) {
if (sk1_rcv_saddr == sk2_rcv_saddr)
return true;
return (match_sk1_wildcard && !sk1_rcv_saddr) ||
(match_sk2_wildcard && !sk2_rcv_saddr);
}
return false;
}
if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
return true;
if (addr_type2 == IPV6_ADDR_ANY && match_sk2_wildcard &&
!(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
return true;
if (addr_type == IPV6_ADDR_ANY && match_sk1_wildcard &&
!(sk1_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
return true;
if (sk2_rcv_saddr6 &&
ipv6_addr_equal(sk1_rcv_saddr6, sk2_rcv_saddr6))
return true;
return false;
}
#endif
/* match_sk*_wildcard == true: 0.0.0.0 equals to any IPv4 addresses
* match_sk*_wildcard == false: addresses must be exactly the same, i.e.
* 0.0.0.0 only equals to 0.0.0.0
*/
static bool ipv4_rcv_saddr_equal(__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
bool sk2_ipv6only, bool match_sk1_wildcard,
bool match_sk2_wildcard)
{
if (!sk2_ipv6only) {
if (sk1_rcv_saddr == sk2_rcv_saddr)
return true;
return (match_sk1_wildcard && !sk1_rcv_saddr) ||
(match_sk2_wildcard && !sk2_rcv_saddr);
}
return false;
}
bool inet_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
bool match_wildcard)
{
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6)
return ipv6_rcv_saddr_equal(&sk->sk_v6_rcv_saddr,
inet6_rcv_saddr(sk2),
sk->sk_rcv_saddr,
sk2->sk_rcv_saddr,
ipv6_only_sock(sk),
ipv6_only_sock(sk2),
match_wildcard,
match_wildcard);
#endif
return ipv4_rcv_saddr_equal(sk->sk_rcv_saddr, sk2->sk_rcv_saddr,
ipv6_only_sock(sk2), match_wildcard,
match_wildcard);
}
EXPORT_SYMBOL(inet_rcv_saddr_equal);
bool inet_rcv_saddr_any(const struct sock *sk)
{
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6)
return ipv6_addr_any(&sk->sk_v6_rcv_saddr);
#endif
return !sk->sk_rcv_saddr;
}
/**
* inet_sk_get_local_port_range - fetch ephemeral ports range
* @sk: socket
* @low: pointer to low port
* @high: pointer to high port
*
* Fetch netns port range (/proc/sys/net/ipv4/ip_local_port_range)
* Range can be overridden if socket got IP_LOCAL_PORT_RANGE option.
* Returns true if IP_LOCAL_PORT_RANGE was set on this socket.
*/
bool inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high)
{
int lo, hi, sk_lo, sk_hi;
bool local_range = false;
u32 sk_range;
inet_get_local_port_range(sock_net(sk), &lo, &hi);
sk_range = READ_ONCE(inet_sk(sk)->local_port_range);
if (unlikely(sk_range)) {
sk_lo = sk_range & 0xffff;
sk_hi = sk_range >> 16;
if (lo <= sk_lo && sk_lo <= hi)
lo = sk_lo;
if (lo <= sk_hi && sk_hi <= hi)
hi = sk_hi;
local_range = true;
}
*low = lo;
*high = hi;
return local_range;
}
EXPORT_SYMBOL(inet_sk_get_local_port_range);
static bool inet_use_bhash2_on_bind(const struct sock *sk)
{
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6) {
int addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
if (addr_type == IPV6_ADDR_ANY)
return false;
if (addr_type != IPV6_ADDR_MAPPED)
return true;
}
#endif
return sk->sk_rcv_saddr != htonl(INADDR_ANY);
}
static bool inet_bind_conflict(const struct sock *sk, struct sock *sk2,
kuid_t sk_uid, bool relax,
bool reuseport_cb_ok, bool reuseport_ok)
{
int bound_dev_if2;
if (sk == sk2)
return false;
bound_dev_if2 = READ_ONCE(sk2->sk_bound_dev_if);
if (!sk->sk_bound_dev_if || !bound_dev_if2 ||
sk->sk_bound_dev_if == bound_dev_if2) {
if (sk->sk_reuse && sk2->sk_reuse &&
sk2->sk_state != TCP_LISTEN) {
if (!relax || (!reuseport_ok && sk->sk_reuseport &&
sk2->sk_reuseport && reuseport_cb_ok &&
(sk2->sk_state == TCP_TIME_WAIT ||
uid_eq(sk_uid, sock_i_uid(sk2)))))
return true;
} else if (!reuseport_ok || !sk->sk_reuseport ||
!sk2->sk_reuseport || !reuseport_cb_ok ||
(sk2->sk_state != TCP_TIME_WAIT &&
!uid_eq(sk_uid, sock_i_uid(sk2)))) {
return true;
}
}
return false;
}
static bool __inet_bhash2_conflict(const struct sock *sk, struct sock *sk2,
kuid_t sk_uid, bool relax,
bool reuseport_cb_ok, bool reuseport_ok)
{
if (ipv6_only_sock(sk2)) {
if (sk->sk_family == AF_INET)
return false;
#if IS_ENABLED(CONFIG_IPV6)
if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
return false;
#endif
}
return inet_bind_conflict(sk, sk2, sk_uid, relax,
reuseport_cb_ok, reuseport_ok);
}
static bool inet_bhash2_conflict(const struct sock *sk,
const struct inet_bind2_bucket *tb2,
kuid_t sk_uid,
bool relax, bool reuseport_cb_ok,
bool reuseport_ok)
{
struct sock *sk2;
sk_for_each_bound(sk2, &tb2->owners) {
if (__inet_bhash2_conflict(sk, sk2, sk_uid, relax,
reuseport_cb_ok, reuseport_ok))
return true;
}
return false;
}
#define sk_for_each_bound_bhash(__sk, __tb2, __tb) \
hlist_for_each_entry(__tb2, &(__tb)->bhash2, bhash_node) \
sk_for_each_bound((__sk), &(__tb2)->owners)
/* This should be called only when the tb and tb2 hashbuckets' locks are held */
static int inet_csk_bind_conflict(const struct sock *sk,
const struct inet_bind_bucket *tb,
const struct inet_bind2_bucket *tb2, /* may be null */
bool relax, bool reuseport_ok)
{
kuid_t uid = sock_i_uid((struct sock *)sk);
struct sock_reuseport *reuseport_cb;
bool reuseport_cb_ok;
struct sock *sk2;
rcu_read_lock();
reuseport_cb = rcu_dereference(sk->sk_reuseport_cb);
/* paired with WRITE_ONCE() in __reuseport_(add|detach)_closed_sock */
reuseport_cb_ok = !reuseport_cb || READ_ONCE(reuseport_cb->num_closed_socks);
rcu_read_unlock();
/* Conflicts with an existing IPV6_ADDR_ANY (if ipv6) or INADDR_ANY (if
* ipv4) should have been checked already. We need to do these two
* checks separately because their spinlocks have to be acquired/released
* independently of each other, to prevent possible deadlocks
*/
if (inet_use_bhash2_on_bind(sk))
return tb2 && inet_bhash2_conflict(sk, tb2, uid, relax,
reuseport_cb_ok, reuseport_ok);
/* Unlike other sk lookup places we do not check
* for sk_net here, since _all_ the socks listed
* in tb->owners and tb2->owners list belong
* to the same net - the one this bucket belongs to.
*/
sk_for_each_bound_bhash(sk2, tb2, tb) {
if (!inet_bind_conflict(sk, sk2, uid, relax, reuseport_cb_ok, reuseport_ok))
continue;
if (inet_rcv_saddr_equal(sk, sk2, true))
return true;
}
return false;
}
/* Determine if there is a bind conflict with an existing IPV6_ADDR_ANY (if ipv6) or
* INADDR_ANY (if ipv4) socket.
*
* Caller must hold bhash hashbucket lock with local bh disabled, to protect
* against concurrent binds on the port for addr any
*/
static bool inet_bhash2_addr_any_conflict(const struct sock *sk, int port, int l3mdev,
bool relax, bool reuseport_ok)
{
kuid_t uid = sock_i_uid((struct sock *)sk);
const struct net *net = sock_net(sk);
struct sock_reuseport *reuseport_cb;
struct inet_bind_hashbucket *head2;
struct inet_bind2_bucket *tb2;
bool conflict = false;
bool reuseport_cb_ok;
rcu_read_lock();
reuseport_cb = rcu_dereference(sk->sk_reuseport_cb);
/* paired with WRITE_ONCE() in __reuseport_(add|detach)_closed_sock */
reuseport_cb_ok = !reuseport_cb || READ_ONCE(reuseport_cb->num_closed_socks);
rcu_read_unlock();
head2 = inet_bhash2_addr_any_hashbucket(sk, net, port);
spin_lock(&head2->lock);
inet_bind_bucket_for_each(tb2, &head2->chain) {
if (!inet_bind2_bucket_match_addr_any(tb2, net, port, l3mdev, sk))
continue;
if (!inet_bhash2_conflict(sk, tb2, uid, relax, reuseport_cb_ok, reuseport_ok))
continue;
conflict = true;
break;
}
spin_unlock(&head2->lock);
return conflict;
}
/*
* Find an open port number for the socket. Returns with the
* inet_bind_hashbucket locks held if successful.
*/
static struct inet_bind_hashbucket *
inet_csk_find_open_port(const struct sock *sk, struct inet_bind_bucket **tb_ret,
struct inet_bind2_bucket **tb2_ret,
struct inet_bind_hashbucket **head2_ret, int *port_ret)
{
struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk);
int i, low, high, attempt_half, port, l3mdev;
struct inet_bind_hashbucket *head, *head2;
struct net *net = sock_net(sk);
struct inet_bind2_bucket *tb2;
struct inet_bind_bucket *tb;
u32 remaining, offset;
bool relax = false;
l3mdev = inet_sk_bound_l3mdev(sk);
ports_exhausted:
attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
other_half_scan:
inet_sk_get_local_port_range(sk, &low, &high);
high++; /* [32768, 60999] -> [32768, 61000[ */
if (high - low < 4)
attempt_half = 0;
if (attempt_half) {
int half = low + (((high - low) >> 2) << 1);
if (attempt_half == 1)
high = half;
else
low = half;
}
remaining = high - low;
if (likely(remaining > 1))
remaining &= ~1U;
offset = get_random_u32_below(remaining);
/* __inet_hash_connect() favors ports having @low parity
* We do the opposite to not pollute connect() users.
*/
offset |= 1U;
other_parity_scan:
port = low + offset;
for (i = 0; i < remaining; i += 2, port += 2) {
if (unlikely(port >= high))
port -= remaining;
if (inet_is_local_reserved_port(net, port))
continue;
head = &hinfo->bhash[inet_bhashfn(net, port,
hinfo->bhash_size)];
spin_lock_bh(&head->lock);
if (inet_use_bhash2_on_bind(sk)) {
if (inet_bhash2_addr_any_conflict(sk, port, l3mdev, relax, false))
goto next_port;
}
head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
spin_lock(&head2->lock);
tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, sk);
inet_bind_bucket_for_each(tb, &head->chain)
if (inet_bind_bucket_match(tb, net, port, l3mdev)) {
if (!inet_csk_bind_conflict(sk, tb, tb2,
relax, false))
goto success;
spin_unlock(&head2->lock);
goto next_port;
}
tb = NULL;
goto success;
next_port:
spin_unlock_bh(&head->lock);
cond_resched();
}
offset--;
if (!(offset & 1))
goto other_parity_scan;
if (attempt_half == 1) {
/* OK we now try the upper half of the range */
attempt_half = 2;
goto other_half_scan;
}
if (READ_ONCE(net->ipv4.sysctl_ip_autobind_reuse) && !relax) {
/* We still have a chance to connect to different destinations */
relax = true;
goto ports_exhausted;
}
return NULL;
success:
*port_ret = port;
*tb_ret = tb;
*tb2_ret = tb2;
*head2_ret = head2;
return head;
}
static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
struct sock *sk)
{
kuid_t uid = sock_i_uid(sk);
if (tb->fastreuseport <= 0)
return 0;
if (!sk->sk_reuseport)
return 0;
if (rcu_access_pointer(sk->sk_reuseport_cb))
return 0;
if (!uid_eq(tb->fastuid, uid))
return 0;
/* We only need to check the rcv_saddr if this tb was once marked
* without fastreuseport and then was reset, as we can only know that
* the fast_*rcv_saddr doesn't have any conflicts with the socks on the
* owners list.
*/
if (tb->fastreuseport == FASTREUSEPORT_ANY)
return 1;
#if IS_ENABLED(CONFIG_IPV6)
if (tb->fast_sk_family == AF_INET6)
return ipv6_rcv_saddr_equal(&tb->fast_v6_rcv_saddr,
inet6_rcv_saddr(sk),
tb->fast_rcv_saddr,
sk->sk_rcv_saddr,
tb->fast_ipv6_only,
ipv6_only_sock(sk), true, false);
#endif
return ipv4_rcv_saddr_equal(tb->fast_rcv_saddr, sk->sk_rcv_saddr,
ipv6_only_sock(sk), true, false);
}
void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
struct sock *sk)
{
kuid_t uid = sock_i_uid(sk);
bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
if (hlist_empty(&tb->bhash2)) {
tb->fastreuse = reuse;
if (sk->sk_reuseport) {
tb->fastreuseport = FASTREUSEPORT_ANY;
tb->fastuid = uid;
tb->fast_rcv_saddr = sk->sk_rcv_saddr;
tb->fast_ipv6_only = ipv6_only_sock(sk);
tb->fast_sk_family = sk->sk_family;
#if IS_ENABLED(CONFIG_IPV6)
tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
#endif
} else {
tb->fastreuseport = 0;
}
} else {
if (!reuse)
tb->fastreuse = 0;
if (sk->sk_reuseport) {
/* We didn't match or we don't have fastreuseport set on
* the tb, but we have sk_reuseport set on this socket
* and we know that there are no bind conflicts with
* this socket in this tb, so reset our tb's reuseport
* settings so that any subsequent sockets that match
* our current socket will be put on the fast path.
*
* If we reset we need to set FASTREUSEPORT_STRICT so we
* do extra checking for all subsequent sk_reuseport
* socks.
*/
if (!sk_reuseport_match(tb, sk)) {
tb->fastreuseport = FASTREUSEPORT_STRICT;
tb->fastuid = uid;
tb->fast_rcv_saddr = sk->sk_rcv_saddr;
tb->fast_ipv6_only = ipv6_only_sock(sk);
tb->fast_sk_family = sk->sk_family;
#if IS_ENABLED(CONFIG_IPV6)
tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
#endif
}
} else {
tb->fastreuseport = 0;
}
}
}
/* Obtain a reference to a local port for the given sock,
* if snum is zero it means select any available local port.
* We try to allocate an odd port (and leave even ports for connect())
*/
int inet_csk_get_port(struct sock *sk, unsigned short snum)
{
struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk);
bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
bool found_port = false, check_bind_conflict = true;
bool bhash_created = false, bhash2_created = false;
int ret = -EADDRINUSE, port = snum, l3mdev;
struct inet_bind_hashbucket *head, *head2;
struct inet_bind2_bucket *tb2 = NULL;
struct inet_bind_bucket *tb = NULL;
bool head2_lock_acquired = false;
struct net *net = sock_net(sk);
l3mdev = inet_sk_bound_l3mdev(sk);
if (!port) {
head = inet_csk_find_open_port(sk, &tb, &tb2, &head2, &port);
if (!head)
return ret;
head2_lock_acquired = true;
if (tb && tb2)
goto success;
found_port = true;
} else {
head = &hinfo->bhash[inet_bhashfn(net, port,
hinfo->bhash_size)];
spin_lock_bh(&head->lock);
inet_bind_bucket_for_each(tb, &head->chain)
if (inet_bind_bucket_match(tb, net, port, l3mdev))
break;
}
if (!tb) {
tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, net,
head, port, l3mdev);
if (!tb)
goto fail_unlock;
bhash_created = true;
}
if (!found_port) {
if (!hlist_empty(&tb->bhash2)) {
if (sk->sk_reuse == SK_FORCE_REUSE ||
(tb->fastreuse > 0 && reuse) ||
sk_reuseport_match(tb, sk))
check_bind_conflict = false;
}
if (check_bind_conflict && inet_use_bhash2_on_bind(sk)) {
if (inet_bhash2_addr_any_conflict(sk, port, l3mdev, true, true))
goto fail_unlock;
}
head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
spin_lock(&head2->lock);
head2_lock_acquired = true;
tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, sk);
}
if (!tb2) {
tb2 = inet_bind2_bucket_create(hinfo->bind2_bucket_cachep,
net, head2, tb, sk);
if (!tb2)
goto fail_unlock;
bhash2_created = true;
}
if (!found_port && check_bind_conflict) {
if (inet_csk_bind_conflict(sk, tb, tb2, true, true))
goto fail_unlock;
}
success:
inet_csk_update_fastreuse(tb, sk);
if (!inet_csk(sk)->icsk_bind_hash)
inet_bind_hash(sk, tb, tb2, port);
WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
WARN_ON(inet_csk(sk)->icsk_bind2_hash != tb2);
ret = 0;
fail_unlock:
if (ret) {
if (bhash2_created)
inet_bind2_bucket_destroy(hinfo->bind2_bucket_cachep, tb2);
if (bhash_created)
inet_bind_bucket_destroy(hinfo->bind_bucket_cachep, tb);
}
if (head2_lock_acquired)
spin_unlock(&head2->lock);
spin_unlock_bh(&head->lock);
return ret;
}
EXPORT_SYMBOL_GPL(inet_csk_get_port);
/*
* Wait for an incoming connection, avoid race conditions. This must be called
* with the socket locked.
*/
static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
{
struct inet_connection_sock *icsk = inet_csk(sk);
DEFINE_WAIT(wait);
int err;
/*
* True wake-one mechanism for incoming connections: only
* one process gets woken up, not the 'whole herd'.
* Since we do not 'race & poll' for established sockets
* anymore, the common case will execute the loop only once.
*
* Subtle issue: "add_wait_queue_exclusive()" will be added
* after any current non-exclusive waiters, and we know that
* it will always _stay_ after any new non-exclusive waiters
* because all non-exclusive waiters are added at the
* beginning of the wait-queue. As such, it's ok to "drop"
* our exclusiveness temporarily when we get woken up without
* having to remove and re-insert us on the wait queue.
*/
for (;;) {
prepare_to_wait_exclusive(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
release_sock(sk);
if (reqsk_queue_empty(&icsk->icsk_accept_queue))
timeo = schedule_timeout(timeo);
sched_annotate_sleep();
lock_sock(sk);
err = 0;
if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
break;
err = -EINVAL;
if (sk->sk_state != TCP_LISTEN)
break;
err = sock_intr_errno(timeo);
if (signal_pending(current))
break;
err = -EAGAIN;
if (!timeo)
break;
}
finish_wait(sk_sleep(sk), &wait);
return err;
}
/*
* This will accept the next outstanding connection.
*/
struct sock *inet_csk_accept(struct sock *sk, struct proto_accept_arg *arg)
{
struct inet_connection_sock *icsk = inet_csk(sk);
struct request_sock_queue *queue = &icsk->icsk_accept_queue;
struct request_sock *req;
struct sock *newsk;
int error;
lock_sock(sk);
/* We need to make sure that this socket is listening,
* and that it has something pending.
*/
error = -EINVAL;
if (sk->sk_state != TCP_LISTEN)
goto out_err;
/* Find already established connection */
if (reqsk_queue_empty(queue)) {
long timeo = sock_rcvtimeo(sk, arg->flags & O_NONBLOCK);
/* If this is a non blocking socket don't sleep */
error = -EAGAIN;
if (!timeo)
goto out_err;
error = inet_csk_wait_for_connect(sk, timeo);
if (error)
goto out_err;
}
req = reqsk_queue_remove(queue, sk);
arg->is_empty = reqsk_queue_empty(queue);
newsk = req->sk;
if (sk->sk_protocol == IPPROTO_TCP &&
tcp_rsk(req)->tfo_listener) {
spin_lock_bh(&queue->fastopenq.lock);
if (tcp_rsk(req)->tfo_listener) {
/* We are still waiting for the final ACK from 3WHS
* so can't free req now. Instead, we set req->sk to
* NULL to signify that the child socket is taken
* so reqsk_fastopen_remove() will free the req
* when 3WHS finishes (or is aborted).
*/
req->sk = NULL;
req = NULL;
}
spin_unlock_bh(&queue->fastopenq.lock);
}
out:
release_sock(sk);
if (newsk && mem_cgroup_sockets_enabled) {
gfp_t gfp = GFP_KERNEL | __GFP_NOFAIL;
int amt = 0;
/* atomically get the memory usage, set and charge the
* newsk->sk_memcg.
*/
lock_sock(newsk);
mem_cgroup_sk_alloc(newsk);
if (newsk->sk_memcg) {
/* The socket has not been accepted yet, no need
* to look at newsk->sk_wmem_queued.
*/
amt = sk_mem_pages(newsk->sk_forward_alloc +
atomic_read(&newsk->sk_rmem_alloc));
}
if (amt)
mem_cgroup_charge_skmem(newsk->sk_memcg, amt, gfp);
kmem_cache_charge(newsk, gfp);
release_sock(newsk);
}
if (req)
reqsk_put(req);
if (newsk)
inet_init_csk_locks(newsk);
return newsk;
out_err:
newsk = NULL;
req = NULL;
arg->err = error;
goto out;
}
EXPORT_SYMBOL(inet_csk_accept);
/*
* Using different timers for retransmit, delayed acks and probes
* We may wish use just one timer maintaining a list of expire jiffies
* to optimize.
*/
void inet_csk_init_xmit_timers(struct sock *sk,
void (*retransmit_handler)(struct timer_list *t),
void (*delack_handler)(struct timer_list *t),
void (*keepalive_handler)(struct timer_list *t))
{
struct inet_connection_sock *icsk = inet_csk(sk);
timer_setup(&icsk->icsk_retransmit_timer, retransmit_handler, 0);
timer_setup(&icsk->icsk_delack_timer, delack_handler, 0);
timer_setup(&sk->sk_timer, keepalive_handler, 0);
icsk->icsk_pending = icsk->icsk_ack.pending = 0;
}
EXPORT_SYMBOL(inet_csk_init_xmit_timers);
void inet_csk_clear_xmit_timers(struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
smp_store_release(&icsk->icsk_pending, 0);
smp_store_release(&icsk->icsk_ack.pending, 0);
sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
sk_stop_timer(sk, &icsk->icsk_delack_timer);
sk_stop_timer(sk, &sk->sk_timer);
}
EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
void inet_csk_clear_xmit_timers_sync(struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
/* ongoing timer handlers need to acquire socket lock. */
sock_not_owned_by_me(sk);
smp_store_release(&icsk->icsk_pending, 0);
smp_store_release(&icsk->icsk_ack.pending, 0);
sk_stop_timer_sync(sk, &icsk->icsk_retransmit_timer);
sk_stop_timer_sync(sk, &icsk->icsk_delack_timer);
sk_stop_timer_sync(sk, &sk->sk_timer);
}
void inet_csk_delete_keepalive_timer(struct sock *sk)
{
sk_stop_timer(sk, &sk->sk_timer);
}
EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
{
sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
}
EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
struct dst_entry *inet_csk_route_req(const struct sock *sk,
struct flowi4 *fl4,
const struct request_sock *req)
{
const struct inet_request_sock *ireq = inet_rsk(req);
struct net *net = read_pnet(&ireq->ireq_net);
struct ip_options_rcu *opt;
struct rtable *rt;
rcu_read_lock();
opt = rcu_dereference(ireq->ireq_opt);
flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
ip_sock_rt_tos(sk), ip_sock_rt_scope(sk),
sk->sk_protocol, inet_sk_flowi_flags(sk),
(opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
ireq->ir_loc_addr, ireq->ir_rmt_port,
htons(ireq->ir_num), sk->sk_uid);
security_req_classify_flow(req, flowi4_to_flowi_common(fl4));
rt = ip_route_output_flow(net, fl4, sk);
if (IS_ERR(rt))
goto no_route;
if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
goto route_err;
rcu_read_unlock();
return &rt->dst;
route_err:
ip_rt_put(rt);
no_route:
rcu_read_unlock();
__IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
return NULL;
}
EXPORT_SYMBOL_GPL(inet_csk_route_req);
struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
struct sock *newsk,
const struct request_sock *req)
{
const struct inet_request_sock *ireq = inet_rsk(req);
struct net *net = read_pnet(&ireq->ireq_net);
struct inet_sock *newinet = inet_sk(newsk);
struct ip_options_rcu *opt;
struct flowi4 *fl4;
struct rtable *rt;
opt = rcu_dereference(ireq->ireq_opt);
fl4 = &newinet->cork.fl.u.ip4;
flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
ip_sock_rt_tos(sk), ip_sock_rt_scope(sk),
sk->sk_protocol, inet_sk_flowi_flags(sk),
(opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
ireq->ir_loc_addr, ireq->ir_rmt_port,
htons(ireq->ir_num), sk->sk_uid);
security_req_classify_flow(req, flowi4_to_flowi_common(fl4));
rt = ip_route_output_flow(net, fl4, sk);
if (IS_ERR(rt))
goto no_route;
if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
goto route_err;
return &rt->dst;
route_err:
ip_rt_put(rt);
no_route:
__IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
return NULL;
}
EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
/* Decide when to expire the request and when to resend SYN-ACK */
static void syn_ack_recalc(struct request_sock *req,
const int max_syn_ack_retries,
const u8 rskq_defer_accept,
int *expire, int *resend)
{
if (!rskq_defer_accept) {
*expire = req->num_timeout >= max_syn_ack_retries;
*resend = 1;
return;
}
*expire = req->num_timeout >= max_syn_ack_retries &&
(!inet_rsk(req)->acked || req->num_timeout >= rskq_defer_accept);
/* Do not resend while waiting for data after ACK,
* start to resend on end of deferring period to give
* last chance for data or ACK to create established socket.
*/
*resend = !inet_rsk(req)->acked ||
req->num_timeout >= rskq_defer_accept - 1;
}
int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req)
{
int err = req->rsk_ops->rtx_syn_ack(parent, req);
if (!err)
req->num_retrans++;
return err;
}
EXPORT_SYMBOL(inet_rtx_syn_ack);
static struct request_sock *
reqsk_alloc_noprof(const struct request_sock_ops *ops, struct sock *sk_listener,
bool attach_listener)
{
struct request_sock *req;
req = kmem_cache_alloc_noprof(ops->slab, GFP_ATOMIC | __GFP_NOWARN);
if (!req)
return NULL;
req->rsk_listener = NULL;
if (attach_listener) {
if (unlikely(!refcount_inc_not_zero(&sk_listener->sk_refcnt))) {
kmem_cache_free(ops->slab, req);
return NULL;
}
req->rsk_listener = sk_listener;
}
req->rsk_ops = ops;
req_to_sk(req)->sk_prot = sk_listener->sk_prot;
sk_node_init(&req_to_sk(req)->sk_node);
sk_tx_queue_clear(req_to_sk(req));
req->saved_syn = NULL;
req->syncookie = 0;
req->timeout = 0;
req->num_timeout = 0;
req->num_retrans = 0;
req->sk = NULL;
refcount_set(&req->rsk_refcnt, 0);
return req;
}
#define reqsk_alloc(...) alloc_hooks(reqsk_alloc_noprof(__VA_ARGS__))
struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
struct sock *sk_listener,
bool attach_listener)
{
struct request_sock *req = reqsk_alloc(ops, sk_listener,
attach_listener);
if (req) {
struct inet_request_sock *ireq = inet_rsk(req);
ireq->ireq_opt = NULL;
#if IS_ENABLED(CONFIG_IPV6)
ireq->pktopts = NULL;
#endif
atomic64_set(&ireq->ir_cookie, 0);
ireq->ireq_state = TCP_NEW_SYN_RECV;
write_pnet(&ireq->ireq_net, sock_net(sk_listener));
ireq->ireq_family = sk_listener->sk_family;
req->timeout = TCP_TIMEOUT_INIT;
}
return req;
}
EXPORT_SYMBOL(inet_reqsk_alloc);
static struct request_sock *inet_reqsk_clone(struct request_sock *req,
struct sock *sk)
{
struct sock *req_sk, *nreq_sk;
struct request_sock *nreq;
nreq = kmem_cache_alloc(req->rsk_ops->slab, GFP_ATOMIC | __GFP_NOWARN);
if (!nreq) {
__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMIGRATEREQFAILURE);
/* paired with refcount_inc_not_zero() in reuseport_migrate_sock() */
sock_put(sk);
return NULL;
}
req_sk = req_to_sk(req);
nreq_sk = req_to_sk(nreq);
memcpy(nreq_sk, req_sk,
offsetof(struct sock, sk_dontcopy_begin));
unsafe_memcpy(&nreq_sk->sk_dontcopy_end, &req_sk->sk_dontcopy_end,
req->rsk_ops->obj_size - offsetof(struct sock, sk_dontcopy_end),
/* alloc is larger than struct, see above */);
sk_node_init(&nreq_sk->sk_node);
nreq_sk->sk_tx_queue_mapping = req_sk->sk_tx_queue_mapping;