forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 238
/
net.c
1579 lines (1349 loc) · 39.5 KB
/
net.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
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/net.h>
#include <linux/compat.h>
#include <net/compat.h>
#include <linux/io_uring.h>
#include <uapi/linux/io_uring.h>
#include "io_uring.h"
#include "kbuf.h"
#include "alloc_cache.h"
#include "net.h"
#include "notif.h"
#include "rsrc.h"
#if defined(CONFIG_NET)
struct io_shutdown {
struct file *file;
int how;
};
struct io_accept {
struct file *file;
struct sockaddr __user *addr;
int __user *addr_len;
int flags;
u32 file_slot;
unsigned long nofile;
};
struct io_socket {
struct file *file;
int domain;
int type;
int protocol;
int flags;
u32 file_slot;
unsigned long nofile;
};
struct io_connect {
struct file *file;
struct sockaddr __user *addr;
int addr_len;
bool in_progress;
bool seen_econnaborted;
};
struct io_sr_msg {
struct file *file;
union {
struct compat_msghdr __user *umsg_compat;
struct user_msghdr __user *umsg;
void __user *buf;
};
unsigned len;
unsigned done_io;
unsigned msg_flags;
unsigned nr_multishot_loops;
u16 flags;
/* initialised and used only by !msg send variants */
u16 addr_len;
u16 buf_group;
void __user *addr;
void __user *msg_control;
/* used only for send zerocopy */
struct io_kiocb *notif;
};
/*
* Number of times we'll try and do receives if there's more data. If we
* exceed this limit, then add us to the back of the queue and retry from
* there. This helps fairness between flooding clients.
*/
#define MULTISHOT_MAX_RETRY 32
static inline bool io_check_multishot(struct io_kiocb *req,
unsigned int issue_flags)
{
/*
* When ->locked_cq is set we only allow to post CQEs from the original
* task context. Usual request completions will be handled in other
* generic paths but multipoll may decide to post extra cqes.
*/
return !(issue_flags & IO_URING_F_IOWQ) ||
!(req->flags & REQ_F_APOLL_MULTISHOT) ||
!req->ctx->task_complete;
}
int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
if (unlikely(sqe->off || sqe->addr || sqe->rw_flags ||
sqe->buf_index || sqe->splice_fd_in))
return -EINVAL;
shutdown->how = READ_ONCE(sqe->len);
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
struct socket *sock;
int ret;
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
ret = __sys_shutdown_sock(sock, shutdown->how);
io_req_set_res(req, ret, 0);
return IOU_OK;
}
static bool io_net_retry(struct socket *sock, int flags)
{
if (!(flags & MSG_WAITALL))
return false;
return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
}
static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_async_msghdr *hdr = req->async_data;
if (!req_has_async_data(req) || issue_flags & IO_URING_F_UNLOCKED)
return;
/* Let normal cleanup path reap it if we fail adding to the cache */
if (io_alloc_cache_put(&req->ctx->netmsg_cache, &hdr->cache)) {
req->async_data = NULL;
req->flags &= ~REQ_F_ASYNC_DATA;
}
}
static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req,
unsigned int issue_flags)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_cache_entry *entry;
struct io_async_msghdr *hdr;
if (!(issue_flags & IO_URING_F_UNLOCKED)) {
entry = io_alloc_cache_get(&ctx->netmsg_cache);
if (entry) {
hdr = container_of(entry, struct io_async_msghdr, cache);
hdr->free_iov = NULL;
req->flags |= REQ_F_ASYNC_DATA;
req->async_data = hdr;
return hdr;
}
}
if (!io_alloc_async_data(req)) {
hdr = req->async_data;
hdr->free_iov = NULL;
return hdr;
}
return NULL;
}
static inline struct io_async_msghdr *io_msg_alloc_async_prep(struct io_kiocb *req)
{
/* ->prep_async is always called from the submission context */
return io_msg_alloc_async(req, 0);
}
static int io_setup_async_msg(struct io_kiocb *req,
struct io_async_msghdr *kmsg,
unsigned int issue_flags)
{
struct io_async_msghdr *async_msg;
if (req_has_async_data(req))
return -EAGAIN;
async_msg = io_msg_alloc_async(req, issue_flags);
if (!async_msg) {
kfree(kmsg->free_iov);
return -ENOMEM;
}
req->flags |= REQ_F_NEED_CLEANUP;
memcpy(async_msg, kmsg, sizeof(*kmsg));
if (async_msg->msg.msg_name)
async_msg->msg.msg_name = &async_msg->addr;
if ((req->flags & REQ_F_BUFFER_SELECT) && !async_msg->msg.msg_iter.nr_segs)
return -EAGAIN;
/* if were using fast_iov, set it to the new one */
if (iter_is_iovec(&kmsg->msg.msg_iter) && !kmsg->free_iov) {
size_t fast_idx = iter_iov(&kmsg->msg.msg_iter) - kmsg->fast_iov;
async_msg->msg.msg_iter.__iov = &async_msg->fast_iov[fast_idx];
}
return -EAGAIN;
}
#ifdef CONFIG_COMPAT
static int io_compat_msg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg,
struct compat_msghdr *msg, int ddir)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
struct compat_iovec __user *uiov;
int ret;
if (copy_from_user(msg, sr->umsg_compat, sizeof(*msg)))
return -EFAULT;
uiov = compat_ptr(msg->msg_iov);
if (req->flags & REQ_F_BUFFER_SELECT) {
compat_ssize_t clen;
iomsg->free_iov = NULL;
if (msg->msg_iovlen == 0) {
sr->len = 0;
} else if (msg->msg_iovlen > 1) {
return -EINVAL;
} else {
if (!access_ok(uiov, sizeof(*uiov)))
return -EFAULT;
if (__get_user(clen, &uiov->iov_len))
return -EFAULT;
if (clen < 0)
return -EINVAL;
sr->len = clen;
}
return 0;
}
iomsg->free_iov = iomsg->fast_iov;
ret = __import_iovec(ddir, (struct iovec __user *)uiov, msg->msg_iovlen,
UIO_FASTIOV, &iomsg->free_iov,
&iomsg->msg.msg_iter, true);
if (unlikely(ret < 0))
return ret;
return 0;
}
#endif
static int io_msg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg,
struct user_msghdr *msg, int ddir)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
int ret;
if (copy_from_user(msg, sr->umsg, sizeof(*sr->umsg)))
return -EFAULT;
if (req->flags & REQ_F_BUFFER_SELECT) {
if (msg->msg_iovlen == 0) {
sr->len = iomsg->fast_iov[0].iov_len = 0;
iomsg->fast_iov[0].iov_base = NULL;
iomsg->free_iov = NULL;
} else if (msg->msg_iovlen > 1) {
return -EINVAL;
} else {
if (copy_from_user(iomsg->fast_iov, msg->msg_iov,
sizeof(*msg->msg_iov)))
return -EFAULT;
sr->len = iomsg->fast_iov[0].iov_len;
iomsg->free_iov = NULL;
}
return 0;
}
iomsg->free_iov = iomsg->fast_iov;
ret = __import_iovec(ddir, msg->msg_iov, msg->msg_iovlen, UIO_FASTIOV,
&iomsg->free_iov, &iomsg->msg.msg_iter, false);
if (unlikely(ret < 0))
return ret;
return 0;
}
static int io_sendmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
struct user_msghdr msg;
int ret;
iomsg->msg.msg_name = &iomsg->addr;
iomsg->msg.msg_iter.nr_segs = 0;
#ifdef CONFIG_COMPAT
if (unlikely(req->ctx->compat)) {
struct compat_msghdr cmsg;
ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ITER_SOURCE);
if (unlikely(ret))
return ret;
return __get_compat_msghdr(&iomsg->msg, &cmsg, NULL);
}
#endif
ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_SOURCE);
if (unlikely(ret))
return ret;
ret = __copy_msghdr(&iomsg->msg, &msg, NULL);
/* save msg_control as sys_sendmsg() overwrites it */
sr->msg_control = iomsg->msg.msg_control_user;
return ret;
}
int io_send_prep_async(struct io_kiocb *req)
{
struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
struct io_async_msghdr *io;
int ret;
if (!zc->addr || req_has_async_data(req))
return 0;
io = io_msg_alloc_async_prep(req);
if (!io)
return -ENOMEM;
ret = move_addr_to_kernel(zc->addr, zc->addr_len, &io->addr);
return ret;
}
static int io_setup_async_addr(struct io_kiocb *req,
struct sockaddr_storage *addr_storage,
unsigned int issue_flags)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
struct io_async_msghdr *io;
if (!sr->addr || req_has_async_data(req))
return -EAGAIN;
io = io_msg_alloc_async(req, issue_flags);
if (!io)
return -ENOMEM;
memcpy(&io->addr, addr_storage, sizeof(io->addr));
return -EAGAIN;
}
int io_sendmsg_prep_async(struct io_kiocb *req)
{
int ret;
if (!io_msg_alloc_async_prep(req))
return -ENOMEM;
ret = io_sendmsg_copy_hdr(req, req->async_data);
if (!ret)
req->flags |= REQ_F_NEED_CLEANUP;
return ret;
}
void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
{
struct io_async_msghdr *io = req->async_data;
kfree(io->free_iov);
}
int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
if (req->opcode == IORING_OP_SEND) {
if (READ_ONCE(sqe->__pad3[0]))
return -EINVAL;
sr->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
sr->addr_len = READ_ONCE(sqe->addr_len);
} else if (sqe->addr2 || sqe->file_index) {
return -EINVAL;
}
sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
sr->len = READ_ONCE(sqe->len);
sr->flags = READ_ONCE(sqe->ioprio);
if (sr->flags & ~IORING_RECVSEND_POLL_FIRST)
return -EINVAL;
sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
if (sr->msg_flags & MSG_DONTWAIT)
req->flags |= REQ_F_NOWAIT;
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
sr->msg_flags |= MSG_CMSG_COMPAT;
#endif
sr->done_io = 0;
return 0;
}
int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
struct io_async_msghdr iomsg, *kmsg;
struct socket *sock;
unsigned flags;
int min_ret = 0;
int ret;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
if (req_has_async_data(req)) {
kmsg = req->async_data;
kmsg->msg.msg_control_user = sr->msg_control;
} else {
ret = io_sendmsg_copy_hdr(req, &iomsg);
if (ret)
return ret;
kmsg = &iomsg;
}
if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
return io_setup_async_msg(req, kmsg, issue_flags);
flags = sr->msg_flags;
if (issue_flags & IO_URING_F_NONBLOCK)
flags |= MSG_DONTWAIT;
if (flags & MSG_WAITALL)
min_ret = iov_iter_count(&kmsg->msg.msg_iter);
ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
if (ret < min_ret) {
if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
return io_setup_async_msg(req, kmsg, issue_flags);
if (ret > 0 && io_net_retry(sock, flags)) {
kmsg->msg.msg_controllen = 0;
kmsg->msg.msg_control = NULL;
sr->done_io += ret;
req->flags |= REQ_F_PARTIAL_IO;
return io_setup_async_msg(req, kmsg, issue_flags);
}
if (ret == -ERESTARTSYS)
ret = -EINTR;
req_set_fail(req);
}
/* fast path, check for non-NULL to avoid function call */
if (kmsg->free_iov)
kfree(kmsg->free_iov);
req->flags &= ~REQ_F_NEED_CLEANUP;
io_netmsg_recycle(req, issue_flags);
if (ret >= 0)
ret += sr->done_io;
else if (sr->done_io)
ret = sr->done_io;
io_req_set_res(req, ret, 0);
return IOU_OK;
}
int io_send(struct io_kiocb *req, unsigned int issue_flags)
{
struct sockaddr_storage __address;
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
struct msghdr msg;
struct socket *sock;
unsigned flags;
int min_ret = 0;
int ret;
msg.msg_name = NULL;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_namelen = 0;
msg.msg_ubuf = NULL;
if (sr->addr) {
if (req_has_async_data(req)) {
struct io_async_msghdr *io = req->async_data;
msg.msg_name = &io->addr;
} else {
ret = move_addr_to_kernel(sr->addr, sr->addr_len, &__address);
if (unlikely(ret < 0))
return ret;
msg.msg_name = (struct sockaddr *)&__address;
}
msg.msg_namelen = sr->addr_len;
}
if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
return io_setup_async_addr(req, &__address, issue_flags);
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len, &msg.msg_iter);
if (unlikely(ret))
return ret;
flags = sr->msg_flags;
if (issue_flags & IO_URING_F_NONBLOCK)
flags |= MSG_DONTWAIT;
if (flags & MSG_WAITALL)
min_ret = iov_iter_count(&msg.msg_iter);
flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
msg.msg_flags = flags;
ret = sock_sendmsg(sock, &msg);
if (ret < min_ret) {
if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
return io_setup_async_addr(req, &__address, issue_flags);
if (ret > 0 && io_net_retry(sock, flags)) {
sr->len -= ret;
sr->buf += ret;
sr->done_io += ret;
req->flags |= REQ_F_PARTIAL_IO;
return io_setup_async_addr(req, &__address, issue_flags);
}
if (ret == -ERESTARTSYS)
ret = -EINTR;
req_set_fail(req);
}
if (ret >= 0)
ret += sr->done_io;
else if (sr->done_io)
ret = sr->done_io;
io_req_set_res(req, ret, 0);
return IOU_OK;
}
static int io_recvmsg_mshot_prep(struct io_kiocb *req,
struct io_async_msghdr *iomsg,
int namelen, size_t controllen)
{
if ((req->flags & (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) ==
(REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) {
int hdr;
if (unlikely(namelen < 0))
return -EOVERFLOW;
if (check_add_overflow(sizeof(struct io_uring_recvmsg_out),
namelen, &hdr))
return -EOVERFLOW;
if (check_add_overflow(hdr, controllen, &hdr))
return -EOVERFLOW;
iomsg->namelen = namelen;
iomsg->controllen = controllen;
return 0;
}
return 0;
}
static int io_recvmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
struct user_msghdr msg;
int ret;
iomsg->msg.msg_name = &iomsg->addr;
iomsg->msg.msg_iter.nr_segs = 0;
#ifdef CONFIG_COMPAT
if (unlikely(req->ctx->compat)) {
struct compat_msghdr cmsg;
ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ITER_DEST);
if (unlikely(ret))
return ret;
ret = __get_compat_msghdr(&iomsg->msg, &cmsg, &iomsg->uaddr);
if (unlikely(ret))
return ret;
return io_recvmsg_mshot_prep(req, iomsg, cmsg.msg_namelen,
cmsg.msg_controllen);
}
#endif
ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_DEST);
if (unlikely(ret))
return ret;
ret = __copy_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
if (unlikely(ret))
return ret;
return io_recvmsg_mshot_prep(req, iomsg, msg.msg_namelen,
msg.msg_controllen);
}
int io_recvmsg_prep_async(struct io_kiocb *req)
{
struct io_async_msghdr *iomsg;
int ret;
if (!io_msg_alloc_async_prep(req))
return -ENOMEM;
iomsg = req->async_data;
ret = io_recvmsg_copy_hdr(req, iomsg);
if (!ret)
req->flags |= REQ_F_NEED_CLEANUP;
return ret;
}
#define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)
int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
if (unlikely(sqe->file_index || sqe->addr2))
return -EINVAL;
sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
sr->len = READ_ONCE(sqe->len);
sr->flags = READ_ONCE(sqe->ioprio);
if (sr->flags & ~(RECVMSG_FLAGS))
return -EINVAL;
sr->msg_flags = READ_ONCE(sqe->msg_flags);
if (sr->msg_flags & MSG_DONTWAIT)
req->flags |= REQ_F_NOWAIT;
if (sr->msg_flags & MSG_ERRQUEUE)
req->flags |= REQ_F_CLEAR_POLLIN;
if (sr->flags & IORING_RECV_MULTISHOT) {
if (!(req->flags & REQ_F_BUFFER_SELECT))
return -EINVAL;
if (sr->msg_flags & MSG_WAITALL)
return -EINVAL;
if (req->opcode == IORING_OP_RECV && sr->len)
return -EINVAL;
req->flags |= REQ_F_APOLL_MULTISHOT;
/*
* Store the buffer group for this multishot receive separately,
* as if we end up doing an io-wq based issue that selects a
* buffer, it has to be committed immediately and that will
* clear ->buf_list. This means we lose the link to the buffer
* list, and the eventual buffer put on completion then cannot
* restore it.
*/
sr->buf_group = req->buf_index;
}
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
sr->msg_flags |= MSG_CMSG_COMPAT;
#endif
sr->done_io = 0;
sr->nr_multishot_loops = 0;
return 0;
}
static inline void io_recv_prep_retry(struct io_kiocb *req)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
sr->done_io = 0;
sr->len = 0; /* get from the provided buffer */
req->buf_index = sr->buf_group;
}
/*
* Finishes io_recv and io_recvmsg.
*
* Returns true if it is actually finished, or false if it should run
* again (for multishot).
*/
static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
struct msghdr *msg, bool mshot_finished,
unsigned issue_flags)
{
unsigned int cflags;
cflags = io_put_kbuf(req, issue_flags);
if (msg->msg_inq && msg->msg_inq != -1)
cflags |= IORING_CQE_F_SOCK_NONEMPTY;
if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
io_req_set_res(req, *ret, cflags);
*ret = IOU_OK;
return true;
}
if (mshot_finished)
goto finish;
/*
* Fill CQE for this receive and see if we should keep trying to
* receive from this socket.
*/
if (io_fill_cqe_req_aux(req, issue_flags & IO_URING_F_COMPLETE_DEFER,
*ret, cflags | IORING_CQE_F_MORE)) {
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
int mshot_retry_ret = IOU_ISSUE_SKIP_COMPLETE;
io_recv_prep_retry(req);
/* Known not-empty or unknown state, retry */
if (cflags & IORING_CQE_F_SOCK_NONEMPTY || msg->msg_inq == -1) {
if (sr->nr_multishot_loops++ < MULTISHOT_MAX_RETRY)
return false;
/* mshot retries exceeded, force a requeue */
sr->nr_multishot_loops = 0;
mshot_retry_ret = IOU_REQUEUE;
}
if (issue_flags & IO_URING_F_MULTISHOT)
*ret = mshot_retry_ret;
else
*ret = -EAGAIN;
return true;
}
/* Otherwise stop multishot but use the current result. */
finish:
io_req_set_res(req, *ret, cflags);
if (issue_flags & IO_URING_F_MULTISHOT)
*ret = IOU_STOP_MULTISHOT;
else
*ret = IOU_OK;
return true;
}
static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
struct io_sr_msg *sr, void __user **buf,
size_t *len)
{
unsigned long ubuf = (unsigned long) *buf;
unsigned long hdr;
hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
kmsg->controllen;
if (*len < hdr)
return -EFAULT;
if (kmsg->controllen) {
unsigned long control = ubuf + hdr - kmsg->controllen;
kmsg->msg.msg_control_user = (void __user *) control;
kmsg->msg.msg_controllen = kmsg->controllen;
}
sr->buf = *buf; /* stash for later copy */
*buf = (void __user *) (ubuf + hdr);
kmsg->payloadlen = *len = *len - hdr;
return 0;
}
struct io_recvmsg_multishot_hdr {
struct io_uring_recvmsg_out msg;
struct sockaddr_storage addr;
};
static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
struct io_async_msghdr *kmsg,
unsigned int flags, bool *finished)
{
int err;
int copy_len;
struct io_recvmsg_multishot_hdr hdr;
if (kmsg->namelen)
kmsg->msg.msg_name = &hdr.addr;
kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
kmsg->msg.msg_namelen = 0;
if (sock->file->f_flags & O_NONBLOCK)
flags |= MSG_DONTWAIT;
err = sock_recvmsg(sock, &kmsg->msg, flags);
*finished = err <= 0;
if (err < 0)
return err;
hdr.msg = (struct io_uring_recvmsg_out) {
.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
};
hdr.msg.payloadlen = err;
if (err > kmsg->payloadlen)
err = kmsg->payloadlen;
copy_len = sizeof(struct io_uring_recvmsg_out);
if (kmsg->msg.msg_namelen > kmsg->namelen)
copy_len += kmsg->namelen;
else
copy_len += kmsg->msg.msg_namelen;
/*
* "fromlen shall refer to the value before truncation.."
* 1003.1g
*/
hdr.msg.namelen = kmsg->msg.msg_namelen;
/* ensure that there is no gap between hdr and sockaddr_storage */
BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
sizeof(struct io_uring_recvmsg_out));
if (copy_to_user(io->buf, &hdr, copy_len)) {
*finished = true;
return -EFAULT;
}
return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
kmsg->controllen + err;
}
int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
struct io_async_msghdr iomsg, *kmsg;
struct socket *sock;
unsigned flags;
int ret, min_ret = 0;
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
bool mshot_finished = true;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
if (req_has_async_data(req)) {
kmsg = req->async_data;
} else {
ret = io_recvmsg_copy_hdr(req, &iomsg);
if (ret)
return ret;
kmsg = &iomsg;
}
if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
return io_setup_async_msg(req, kmsg, issue_flags);
if (!io_check_multishot(req, issue_flags))
return io_setup_async_msg(req, kmsg, issue_flags);
retry_multishot:
if (io_do_buffer_select(req)) {
void __user *buf;
size_t len = sr->len;
buf = io_buffer_select(req, &len, issue_flags);
if (!buf)
return -ENOBUFS;
if (req->flags & REQ_F_APOLL_MULTISHOT) {
ret = io_recvmsg_prep_multishot(kmsg, sr, &buf, &len);
if (ret) {
io_kbuf_recycle(req, issue_flags);
return ret;
}
}
iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, buf, len);
}
flags = sr->msg_flags;
if (force_nonblock)
flags |= MSG_DONTWAIT;
kmsg->msg.msg_get_inq = 1;
kmsg->msg.msg_inq = -1;
if (req->flags & REQ_F_APOLL_MULTISHOT) {
ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
&mshot_finished);
} else {
/* disable partial retry for recvmsg with cmsg attached */
if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen)
min_ret = iov_iter_count(&kmsg->msg.msg_iter);
ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
kmsg->uaddr, flags);
}
if (ret < min_ret) {
if (ret == -EAGAIN && force_nonblock) {
ret = io_setup_async_msg(req, kmsg, issue_flags);
if (ret == -EAGAIN && (issue_flags & IO_URING_F_MULTISHOT)) {
io_kbuf_recycle(req, issue_flags);
return IOU_ISSUE_SKIP_COMPLETE;
}
return ret;
}
if (ret > 0 && io_net_retry(sock, flags)) {
sr->done_io += ret;
req->flags |= REQ_F_PARTIAL_IO;
return io_setup_async_msg(req, kmsg, issue_flags);
}
if (ret == -ERESTARTSYS)
ret = -EINTR;
req_set_fail(req);
} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
req_set_fail(req);
}
if (ret > 0)
ret += sr->done_io;
else if (sr->done_io)
ret = sr->done_io;
else
io_kbuf_recycle(req, issue_flags);
if (!io_recv_finish(req, &ret, &kmsg->msg, mshot_finished, issue_flags))
goto retry_multishot;
if (mshot_finished) {
/* fast path, check for non-NULL to avoid function call */
if (kmsg->free_iov)
kfree(kmsg->free_iov);
io_netmsg_recycle(req, issue_flags);
req->flags &= ~REQ_F_NEED_CLEANUP;
} else if (ret == -EAGAIN)
return io_setup_async_msg(req, kmsg, issue_flags);
return ret;
}
int io_recv(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
struct msghdr msg;
struct socket *sock;
unsigned flags;
int ret, min_ret = 0;
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
size_t len = sr->len;
if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
return -EAGAIN;
if (!io_check_multishot(req, issue_flags))
return -EAGAIN;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_control = NULL;
msg.msg_get_inq = 1;
msg.msg_controllen = 0;
msg.msg_iocb = NULL;
msg.msg_ubuf = NULL;
retry_multishot:
if (io_do_buffer_select(req)) {
void __user *buf;
buf = io_buffer_select(req, &len, issue_flags);
if (!buf)
return -ENOBUFS;
sr->buf = buf;
sr->len = len;
}
ret = import_ubuf(ITER_DEST, sr->buf, len, &msg.msg_iter);
if (unlikely(ret))
goto out_free;
msg.msg_inq = -1;
msg.msg_flags = 0;
flags = sr->msg_flags;
if (force_nonblock)
flags |= MSG_DONTWAIT;
if (flags & MSG_WAITALL)
min_ret = iov_iter_count(&msg.msg_iter);
ret = sock_recvmsg(sock, &msg, flags);
if (ret < min_ret) {
if (ret == -EAGAIN && force_nonblock) {
if (issue_flags & IO_URING_F_MULTISHOT) {
io_kbuf_recycle(req, issue_flags);
return IOU_ISSUE_SKIP_COMPLETE;
}
return -EAGAIN;
}
if (ret > 0 && io_net_retry(sock, flags)) {
sr->len -= ret;
sr->buf += ret;
sr->done_io += ret;
req->flags |= REQ_F_PARTIAL_IO;
return -EAGAIN;
}
if (ret == -ERESTARTSYS)
ret = -EINTR;
req_set_fail(req);
} else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
out_free:
req_set_fail(req);
}