summaryrefslogtreecommitdiff
path: root/net/rxrpc/af_rxrpc.c
blob: d72ddb67bb742a0f6db6db765dd0035c94f636e8 (plain)
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
// SPDX-License-Identifier: GPL-2.0-or-later
/* AF_RXRPC implementation
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/random.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/key-type.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#define CREATE_TRACE_POINTS
#include "ar-internal.h"

MODULE_DESCRIPTION("RxRPC network protocol");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_RXRPC);

unsigned int rxrpc_debug; // = RXRPC_DEBUG_KPROTO;
module_param_named(debug, rxrpc_debug, uint, 0644);
MODULE_PARM_DESC(debug, "RxRPC debugging mask");

static struct proto rxrpc_proto;
static const struct proto_ops rxrpc_rpc_ops;

/* current debugging ID */
atomic_t rxrpc_debug_id;
EXPORT_SYMBOL(rxrpc_debug_id);

/* count of skbs currently in use */
atomic_t rxrpc_n_tx_skbs, rxrpc_n_rx_skbs;

struct workqueue_struct *rxrpc_workqueue;

static void rxrpc_sock_destructor(struct sock *);

/*
 * see if an RxRPC socket is currently writable
 */
static inline int rxrpc_writable(struct sock *sk)
{
	return refcount_read(&sk->sk_wmem_alloc) < (size_t) sk->sk_sndbuf;
}

/*
 * wait for write bufferage to become available
 */
static void rxrpc_write_space(struct sock *sk)
{
	_enter("%p", sk);
	rcu_read_lock();
	if (rxrpc_writable(sk)) {
		struct socket_wq *wq = rcu_dereference(sk->sk_wq);

		if (skwq_has_sleeper(wq))
			wake_up_interruptible(&wq->wait);
		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
	}
	rcu_read_unlock();
}

/*
 * validate an RxRPC address
 */
static int rxrpc_validate_address(struct rxrpc_sock *rx,
				  struct sockaddr_rxrpc *srx,
				  int len)
{
	unsigned int tail;

	if (len < sizeof(struct sockaddr_rxrpc))
		return -EINVAL;

	if (srx->srx_family != AF_RXRPC)
		return -EAFNOSUPPORT;

	if (srx->transport_type != SOCK_DGRAM)
		return -ESOCKTNOSUPPORT;

	len -= offsetof(struct sockaddr_rxrpc, transport);
	if (srx->transport_len < sizeof(sa_family_t) ||
	    srx->transport_len > len)
		return -EINVAL;

	if (srx->transport.family != rx->family &&
	    srx->transport.family == AF_INET && rx->family != AF_INET6)
		return -EAFNOSUPPORT;

	switch (srx->transport.family) {
	case AF_INET:
		if (srx->transport_len < sizeof(struct sockaddr_in))
			return -EINVAL;
		tail = offsetof(struct sockaddr_rxrpc, transport.sin.__pad);
		break;

#ifdef CONFIG_AF_RXRPC_IPV6
	case AF_INET6:
		if (srx->transport_len < sizeof(struct sockaddr_in6))
			return -EINVAL;
		tail = offsetof(struct sockaddr_rxrpc, transport) +
			sizeof(struct sockaddr_in6);
		break;
#endif

	default:
		return -EAFNOSUPPORT;
	}

	if (tail < len)
		memset((void *)srx + tail, 0, len - tail);
	_debug("INET: %pISp", &srx->transport);
	return 0;
}

/*
 * bind a local address to an RxRPC socket
 */
static int rxrpc_bind(struct socket *sock, struct sockaddr *saddr, int len)
{
	struct sockaddr_rxrpc *srx = (struct sockaddr_rxrpc *)saddr;
	struct rxrpc_local *local;
	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
	u16 service_id;
	int ret;

	_enter("%p,%p,%d", rx, saddr, len);

	ret = rxrpc_validate_address(rx, srx, len);
	if (ret < 0)
		goto error;
	service_id = srx->srx_service;

	lock_sock(&rx->sk);

	switch (rx->sk.sk_state) {
	case RXRPC_UNBOUND:
		rx->srx = *srx;
		local = rxrpc_lookup_local(sock_net(&rx->sk), &rx->srx);
		if (IS_ERR(local)) {
			ret = PTR_ERR(local);
			goto error_unlock;
		}

		if (service_id) {
			write_lock(&local->services_lock);
			if (rcu_access_pointer(local->service))
				goto service_in_use;
			rx->local = local;
			rcu_assign_pointer(local->service, rx);
			write_unlock(&local->services_lock);

			rx->sk.sk_state = RXRPC_SERVER_BOUND;
		} else {
			rx->local = local;
			rx->sk.sk_state = RXRPC_CLIENT_BOUND;
		}
		break;

	case RXRPC_SERVER_BOUND:
		ret = -EINVAL;
		if (service_id == 0)
			goto error_unlock;
		ret = -EADDRINUSE;
		if (service_id == rx->srx.srx_service)
			goto error_unlock;
		ret = -EINVAL;
		srx->srx_service = rx->srx.srx_service;
		if (memcmp(srx, &rx->srx, sizeof(*srx)) != 0)
			goto error_unlock;
		rx->second_service = service_id;
		rx->sk.sk_state = RXRPC_SERVER_BOUND2;
		break;

	default:
		ret = -EINVAL;
		goto error_unlock;
	}

	release_sock(&rx->sk);
	_leave(" = 0");
	return 0;

service_in_use:
	write_unlock(&local->services_lock);
	rxrpc_unuse_local(local);
	ret = -EADDRINUSE;
error_unlock:
	release_sock(&rx->sk);
error:
	_leave(" = %d", ret);
	return ret;
}

/*
 * set the number of pending calls permitted on a listening socket
 */
static int rxrpc_listen(struct socket *sock, int backlog)
{
	struct sock *sk = sock->sk;
	struct rxrpc_sock *rx = rxrpc_sk(sk);
	unsigned int max, old;
	int ret;

	_enter("%p,%d", rx, backlog);

	lock_sock(&rx->sk);

	switch (rx->sk.sk_state) {
	case RXRPC_UNBOUND:
		ret = -EADDRNOTAVAIL;
		break;
	case RXRPC_SERVER_BOUND:
	case RXRPC_SERVER_BOUND2:
		ASSERT(rx->local != NULL);
		max = READ_ONCE(rxrpc_max_backlog);
		ret = -EINVAL;
		if (backlog == INT_MAX)
			backlog = max;
		else if (backlog < 0 || backlog > max)
			break;
		old = sk->sk_max_ack_backlog;
		sk->sk_max_ack_backlog = backlog;
		ret = rxrpc_service_prealloc(rx, GFP_KERNEL);
		if (ret == 0)
			rx->sk.sk_state = RXRPC_SERVER_LISTENING;
		else
			sk->sk_max_ack_backlog = old;
		break;
	case RXRPC_SERVER_LISTENING:
		if (backlog == 0) {
			rx->sk.sk_state = RXRPC_SERVER_LISTEN_DISABLED;
			sk->sk_max_ack_backlog = 0;
			rxrpc_discard_prealloc(rx);
			ret = 0;
			break;
		}
		/* Fall through */
	default:
		ret = -EBUSY;
		break;
	}

	release_sock(&rx->sk);
	_leave(" = %d", ret);
	return ret;
}

/**
 * rxrpc_kernel_begin_call - Allow a kernel service to begin a call
 * @sock: The socket on which to make the call
 * @srx: The address of the peer to contact
 * @key: The security context to use (defaults to socket setting)
 * @user_call_ID: The ID to use
 * @tx_total_len: Total length of data to transmit during the call (or -1)
 * @gfp: The allocation constraints
 * @notify_rx: Where to send notifications instead of socket queue
 * @upgrade: Request service upgrade for call
 * @intr: The call is interruptible
 * @debug_id: The debug ID for tracing to be assigned to the call
 *
 * Allow a kernel service to begin a call on the nominated socket.  This just
 * sets up all the internal tracking structures and allocates connection and
 * call IDs as appropriate.  The call to be used is returned.
 *
 * The default socket destination address and security may be overridden by
 * supplying @srx and @key.
 */
struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
					   struct sockaddr_rxrpc *srx,
					   struct key *key,
					   unsigned long user_call_ID,
					   s64 tx_total_len,
					   gfp_t gfp,
					   rxrpc_notify_rx_t notify_rx,
					   bool upgrade,
					   bool intr,
					   unsigned int debug_id)
{
	struct rxrpc_conn_parameters cp;
	struct rxrpc_call_params p;
	struct rxrpc_call *call;
	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
	int ret;

	_enter(",,%x,%lx", key_serial(key), user_call_ID);

	ret = rxrpc_validate_address(rx, srx, sizeof(*srx));
	if (ret < 0)
		return ERR_PTR(ret);

	lock_sock(&rx->sk);

	if (!key)
		key = rx->key;
	if (key && !key->payload.data[0])
		key = NULL; /* a no-security key */

	memset(&p, 0, sizeof(p));
	p.user_call_ID = user_call_ID;
	p.tx_total_len = tx_total_len;
	p.intr = intr;

	memset(&cp, 0, sizeof(cp));
	cp.local		= rx->local;
	cp.key			= key;
	cp.security_level	= rx->min_sec_level;
	cp.exclusive		= false;
	cp.upgrade		= upgrade;
	cp.service_id		= srx->srx_service;
	call = rxrpc_new_client_call(rx, &cp, srx, &p, gfp, debug_id);
	/* The socket has been unlocked. */
	if (!IS_ERR(call)) {
		call->notify_rx = notify_rx;
		mutex_unlock(&call->user_mutex);
	}

	rxrpc_put_peer(cp.peer);
	_leave(" = %p", call);
	return call;
}
EXPORT_SYMBOL(rxrpc_kernel_begin_call);

/*
 * Dummy function used to stop the notifier talking to recvmsg().
 */
static void rxrpc_dummy_notify_rx(struct sock *sk, struct rxrpc_call *rxcall,
				  unsigned long call_user_ID)
{
}

/**
 * rxrpc_kernel_end_call - Allow a kernel service to end a call it was using
 * @sock: The socket the call is on
 * @call: The call to end
 *
 * Allow a kernel service to end a call it was using.  The call must be
 * complete before this is called (the call should be aborted if necessary).
 */
void rxrpc_kernel_end_call(struct socket *sock, struct rxrpc_call *call)
{
	_enter("%d{%d}", call->debug_id, atomic_read(&call->usage));

	mutex_lock(&call->user_mutex);
	rxrpc_release_call(rxrpc_sk(sock->sk), call);

	/* Make sure we're not going to call back into a kernel service */
	if (call->notify_rx) {
		spin_lock_bh(&call->notify_lock);
		call->notify_rx = rxrpc_dummy_notify_rx;
		spin_unlock_bh(&call->notify_lock);
	}

	mutex_unlock(&call->user_mutex);
	rxrpc_put_call(call, rxrpc_call_put_kernel);
}
EXPORT_SYMBOL(rxrpc_kernel_end_call);

/**
 * rxrpc_kernel_check_life - Check to see whether a call is still alive
 * @sock: The socket the call is on
 * @call: The call to check
 * @_life: Where to store the life value
 *
 * Allow a kernel service to find out whether a call is still alive - ie. we're
 * getting ACKs from the server.  Passes back in *_life a number representing
 * the life state which can be compared to that returned by a previous call and
 * return true if the call is still alive.
 *
 * If the life state stalls, rxrpc_kernel_probe_life() should be called and
 * then 2RTT waited.
 */
bool rxrpc_kernel_check_life(const struct socket *sock,
			     const struct rxrpc_call *call,
			     u32 *_life)
{
	*_life = call->acks_latest;
	return call->state != RXRPC_CALL_COMPLETE;
}
EXPORT_SYMBOL(rxrpc_kernel_check_life);

/**
 * rxrpc_kernel_probe_life - Poke the peer to see if it's still alive
 * @sock: The socket the call is on
 * @call: The call to check
 *
 * In conjunction with rxrpc_kernel_check_life(), allow a kernel service to
 * find out whether a call is still alive by pinging it.  This should cause the
 * life state to be bumped in about 2*RTT.
 *
 * The must be called in TASK_RUNNING state on pain of might_sleep() objecting.
 */
void rxrpc_kernel_probe_life(struct socket *sock, struct rxrpc_call *call)
{
	rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, true, false,
			  rxrpc_propose_ack_ping_for_check_life);
	rxrpc_send_ack_packet(call, true, NULL);
}
EXPORT_SYMBOL(rxrpc_kernel_probe_life);

/**
 * rxrpc_kernel_get_epoch - Retrieve the epoch value from a call.
 * @sock: The socket the call is on
 * @call: The call to query
 *
 * Allow a kernel service to retrieve the epoch value from a service call to
 * see if the client at the other end rebooted.
 */
u32 rxrpc_kernel_get_epoch(struct socket *sock, struct rxrpc_call *call)
{
	return call->conn->proto.epoch;
}
EXPORT_SYMBOL(rxrpc_kernel_get_epoch);

/**
 * rxrpc_kernel_new_call_notification - Get notifications of new calls
 * @sock: The socket to intercept received messages on
 * @notify_new_call: Function to be called when new calls appear
 * @discard_new_call: Function to discard preallocated calls
 *
 * Allow a kernel service to be given notifications about new calls.
 */
void rxrpc_kernel_new_call_notification(
	struct socket *sock,
	rxrpc_notify_new_call_t notify_new_call,
	rxrpc_discard_new_call_t discard_new_call)
{
	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);

	rx->notify_new_call = notify_new_call;
	rx->discard_new_call = discard_new_call;
}
EXPORT_SYMBOL(rxrpc_kernel_new_call_notification);

/**
 * rxrpc_kernel_set_max_life - Set maximum lifespan on a call
 * @sock: The socket the call is on
 * @call: The call to configure
 * @hard_timeout: The maximum lifespan of the call in jiffies
 *
 * Set the maximum lifespan of a call.  The call will end with ETIME or
 * ETIMEDOUT if it takes longer than this.
 */
void rxrpc_kernel_set_max_life(struct socket *sock, struct rxrpc_call *call,
			       unsigned long hard_timeout)
{
	unsigned long now;

	mutex_lock(&call->user_mutex);

	now = jiffies;
	hard_timeout += now;
	WRITE_ONCE(call->expect_term_by, hard_timeout);
	rxrpc_reduce_call_timer(call, hard_timeout, now, rxrpc_timer_set_for_hard);

	mutex_unlock(&call->user_mutex);
}
EXPORT_SYMBOL(rxrpc_kernel_set_max_life);

/*
 * connect an RxRPC socket
 * - this just targets it at a specific destination; no actual connection
 *   negotiation takes place
 */
static int rxrpc_connect(struct socket *sock, struct sockaddr *addr,
			 int addr_len, int flags)
{
	struct sockaddr_rxrpc *srx = (struct sockaddr_rxrpc *)addr;
	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
	int ret;

	_enter("%p,%p,%d,%d", rx, addr, addr_len, flags);

	ret = rxrpc_validate_address(rx, srx, addr_len);
	if (ret < 0) {
		_leave(" = %d [bad addr]", ret);
		return ret;
	}

	lock_sock(&rx->sk);

	ret = -EISCONN;
	if (test_bit(RXRPC_SOCK_CONNECTED, &rx->flags))
		goto error;

	switch (rx->sk.sk_state) {
	case RXRPC_UNBOUND:
		rx->sk.sk_state = RXRPC_CLIENT_UNBOUND;
	case RXRPC_CLIENT_UNBOUND:
	case RXRPC_CLIENT_BOUND:
		break;
	default:
		ret = -EBUSY;
		goto error;
	}

	rx->connect_srx = *srx;
	set_bit(RXRPC_SOCK_CONNECTED, &rx->flags);
	ret = 0;

error:
	release_sock(&rx->sk);
	return ret;
}

/*
 * send a message through an RxRPC socket
 * - in a client this does a number of things:
 *   - finds/sets up a connection for the security specified (if any)
 *   - initiates a call (ID in control data)
 *   - ends the request phase of a call (if MSG_MORE is not set)
 *   - sends a call data packet
 *   - may send an abort (abort code in control data)
 */
static int rxrpc_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
{
	struct rxrpc_local *local;
	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
	int ret;

	_enter(",{%d},,%zu", rx->sk.sk_state, len);

	if (m->msg_flags & MSG_OOB)
		return -EOPNOTSUPP;

	if (m->msg_name) {
		ret = rxrpc_validate_address(rx, m->msg_name, m->msg_namelen);
		if (ret < 0) {
			_leave(" = %d [bad addr]", ret);
			return ret;
		}
	}

	lock_sock(&rx->sk);

	switch (rx->sk.sk_state) {
	case RXRPC_UNBOUND:
	case RXRPC_CLIENT_UNBOUND:
		rx->srx.srx_family = AF_RXRPC;
		rx->srx.srx_service = 0;
		rx->srx.transport_type = SOCK_DGRAM;
		rx->srx.transport.family = rx->family;
		switch (rx->family) {
		case AF_INET:
			rx->srx.transport_len = sizeof(struct sockaddr_in);
			break;
#ifdef CONFIG_AF_RXRPC_IPV6
		case AF_INET6:
			rx->srx.transport_len = sizeof(struct sockaddr_in6);
			break;
#endif
		default:
			ret = -EAFNOSUPPORT;
			goto error_unlock;
		}
		local = rxrpc_lookup_local(sock_net(sock->sk), &rx->srx);
		if (IS_ERR(local)) {
			ret = PTR_ERR(local);
			goto error_unlock;
		}

		rx->local = local;
		rx->sk.sk_state = RXRPC_CLIENT_BOUND;
		/* Fall through */

	case RXRPC_CLIENT_BOUND:
		if (!m->msg_name &&
		    test_bit(RXRPC_SOCK_CONNECTED, &rx->flags)) {
			m->msg_name = &rx->connect_srx;
			m->msg_namelen = sizeof(rx->connect_srx);
		}
		/* Fall through */
	case RXRPC_SERVER_BOUND:
	case RXRPC_SERVER_LISTENING:
		ret = rxrpc_do_sendmsg(rx, m, len);
		/* The socket has been unlocked */
		goto out;
	default:
		ret = -EINVAL;
		goto error_unlock;
	}

error_unlock:
	release_sock(&rx->sk);
out:
	_leave(" = %d", ret);
	return ret;
}

/*
 * set RxRPC socket options
 */
static int rxrpc_setsockopt(struct socket *sock, int level, int optname,
			    char __user *optval, unsigned int optlen)
{
	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
	unsigned int min_sec_level;
	u16 service_upgrade[2];
	int ret;

	_enter(",%d,%d,,%d", level, optname, optlen);

	lock_sock(&rx->sk);
	ret = -EOPNOTSUPP;

	if (level == SOL_RXRPC) {
		switch (optname) {
		case RXRPC_EXCLUSIVE_CONNECTION:
			ret = -EINVAL;
			if (optlen != 0)
				goto error;
			ret = -EISCONN;
			if (rx->sk.sk_state != RXRPC_UNBOUND)
				goto error;
			rx->exclusive = true;
			goto success;

		case RXRPC_SECURITY_KEY:
			ret = -EINVAL;
			if (rx->key)
				goto error;
			ret = -EISCONN;
			if (rx->sk.sk_state != RXRPC_UNBOUND)
				goto error;
			ret = rxrpc_request_key(rx, optval, optlen);
			goto error;

		case RXRPC_SECURITY_KEYRING:
			ret = -EINVAL;
			if (rx->key)
				goto error;
			ret = -EISCONN;
			if (rx->sk.sk_state != RXRPC_UNBOUND)
				goto error;
			ret = rxrpc_server_keyring(rx, optval, optlen);
			goto error;

		case RXRPC_MIN_SECURITY_LEVEL:
			ret = -EINVAL;
			if (optlen != sizeof(unsigned int))
				goto error;
			ret = -EISCONN;
			if (rx->sk.sk_state != RXRPC_UNBOUND)
				goto error;
			ret = get_user(min_sec_level,
				       (unsigned int __user *) optval);
			if (ret < 0)
				goto error;
			ret = -EINVAL;
			if (min_sec_level > RXRPC_SECURITY_MAX)
				goto error;
			rx->min_sec_level = min_sec_level;
			goto success;

		case RXRPC_UPGRADEABLE_SERVICE:
			ret = -EINVAL;
			if (optlen != sizeof(service_upgrade) ||
			    rx->service_upgrade.from != 0)
				goto error;
			ret = -EISCONN;
			if (rx->sk.sk_state != RXRPC_SERVER_BOUND2)
				goto error;
			ret = -EFAULT;
			if (copy_from_user(service_upgrade, optval,
					   sizeof(service_upgrade)) != 0)
				goto error;
			ret = -EINVAL;
			if ((service_upgrade[0] != rx->srx.srx_service ||
			     service_upgrade[1] != rx->second_service) &&
			    (service_upgrade[0] != rx->second_service ||
			     service_upgrade[1] != rx->srx.srx_service))
				goto error;
			rx->service_upgrade.from = service_upgrade[0];
			rx->service_upgrade.to = service_upgrade[1];
			goto success;

		default:
			break;
		}
	}

success:
	ret = 0;
error:
	release_sock(&rx->sk);
	return ret;
}

/*
 * Get socket options.
 */
static int rxrpc_getsockopt(struct socket *sock, int level, int optname,
			    char __user *optval, int __user *_optlen)
{
	int optlen;

	if (level != SOL_RXRPC)
		return -EOPNOTSUPP;

	if (get_user(optlen, _optlen))
		return -EFAULT;

	switch (optname) {
	case RXRPC_SUPPORTED_CMSG:
		if (optlen < sizeof(int))
			return -ETOOSMALL;
		if (put_user(RXRPC__SUPPORTED - 1, (int __user *)optval) ||
		    put_user(sizeof(int), _optlen))
			return -EFAULT;
		return 0;

	default:
		return -EOPNOTSUPP;
	}
}

/*
 * permit an RxRPC socket to be polled
 */
static __poll_t rxrpc_poll(struct file *file, struct socket *sock,
			       poll_table *wait)
{
	struct sock *sk = sock->sk;
	struct rxrpc_sock *rx = rxrpc_sk(sk);
	__poll_t mask;

	sock_poll_wait(file, sock, wait);
	mask = 0;

	/* the socket is readable if there are any messages waiting on the Rx
	 * queue */
	if (!list_empty(&rx->recvmsg_q))
		mask |= EPOLLIN | EPOLLRDNORM;

	/* the socket is writable if there is space to add new data to the
	 * socket; there is no guarantee that any particular call in progress
	 * on the socket may have space in the Tx ACK window */
	if (rxrpc_writable(sk))
		mask |= EPOLLOUT | EPOLLWRNORM;

	return mask;
}

/*
 * create an RxRPC socket
 */
static int rxrpc_create(struct net *net, struct socket *sock, int protocol,
			int kern)
{
	struct rxrpc_net *rxnet;
	struct rxrpc_sock *rx;
	struct sock *sk;

	_enter("%p,%d", sock, protocol);

	/* we support transport protocol UDP/UDP6 only */
	if (protocol != PF_INET &&
	    IS_ENABLED(CONFIG_AF_RXRPC_IPV6) && protocol != PF_INET6)
		return -EPROTONOSUPPORT;

	if (sock->type != SOCK_DGRAM)
		return -ESOCKTNOSUPPORT;

	sock->ops = &rxrpc_rpc_ops;
	sock->state = SS_UNCONNECTED;

	sk = sk_alloc(net, PF_RXRPC, GFP_KERNEL, &rxrpc_proto, kern);
	if (!sk)
		return -ENOMEM;

	sock_init_data(sock, sk);
	sock_set_flag(sk, SOCK_RCU_FREE);
	sk->sk_state		= RXRPC_UNBOUND;
	sk->sk_write_space	= rxrpc_write_space;
	sk->sk_max_ack_backlog	= 0;
	sk->sk_destruct		= rxrpc_sock_destructor;

	rx = rxrpc_sk(sk);
	rx->family = protocol;
	rx->calls = RB_ROOT;

	spin_lock_init(&rx->incoming_lock);
	INIT_LIST_HEAD(&rx->sock_calls);
	INIT_LIST_HEAD(&rx->to_be_accepted);
	INIT_LIST_HEAD(&rx->recvmsg_q);
	rwlock_init(&rx->recvmsg_lock);
	rwlock_init(&rx->call_lock);
	memset(&rx->srx, 0, sizeof(rx->srx));

	rxnet = rxrpc_net(sock_net(&rx->sk));
	timer_reduce(&rxnet->peer_keepalive_timer, jiffies + 1);

	_leave(" = 0 [%p]", rx);
	return 0;
}

/*
 * Kill all the calls on a socket and shut it down.
 */
static int rxrpc_shutdown(struct socket *sock, int flags)
{
	struct sock *sk = sock->sk;
	struct rxrpc_sock *rx = rxrpc_sk(sk);
	int ret = 0;

	_enter("%p,%d", sk, flags);

	if (flags != SHUT_RDWR)
		return -EOPNOTSUPP;
	if (sk->sk_state == RXRPC_CLOSE)
		return -ESHUTDOWN;

	lock_sock(sk);

	spin_lock_bh(&sk->sk_receive_queue.lock);
	if (sk->sk_state < RXRPC_CLOSE) {
		sk->sk_state = RXRPC_CLOSE;
		sk->sk_shutdown = SHUTDOWN_MASK;
	} else {
		ret = -ESHUTDOWN;
	}
	spin_unlock_bh(&sk->sk_receive_queue.lock);

	rxrpc_discard_prealloc(rx);

	release_sock(sk);
	return ret;
}

/*
 * RxRPC socket destructor
 */
static void rxrpc_sock_destructor(struct sock *sk)
{
	_enter("%p", sk);

	rxrpc_purge_queue(&sk->sk_receive_queue);

	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
	WARN_ON(!sk_unhashed(sk));
	WARN_ON(sk->sk_socket);

	if (!sock_flag(sk, SOCK_DEAD)) {
		printk("Attempt to release alive rxrpc socket: %p\n", sk);
		return;
	}
}

/*
 * release an RxRPC socket
 */
static int rxrpc_release_sock(struct sock *sk)
{
	struct rxrpc_sock *rx = rxrpc_sk(sk);

	_enter("%p{%d,%d}", sk, sk->sk_state, refcount_read(&sk->sk_refcnt));

	/* declare the socket closed for business */
	sock_orphan(sk);
	sk->sk_shutdown = SHUTDOWN_MASK;

	/* We want to kill off all connections from a service socket
	 * as fast as possible because we can't share these; client
	 * sockets, on the other hand, can share an endpoint.
	 */
	switch (sk->sk_state) {
	case RXRPC_SERVER_BOUND:
	case RXRPC_SERVER_BOUND2:
	case RXRPC_SERVER_LISTENING:
	case RXRPC_SERVER_LISTEN_DISABLED:
		rx->local->service_closed = true;
		break;
	}

	spin_lock_bh(&sk->sk_receive_queue.lock);
	sk->sk_state = RXRPC_CLOSE;
	spin_unlock_bh(&sk->sk_receive_queue.lock);

	if (rx->local && rcu_access_pointer(rx->local->service) == rx) {
		write_lock(&rx->local->services_lock);
		rcu_assign_pointer(rx->local->service, NULL);
		write_unlock(&rx->local->services_lock);
	}

	/* try to flush out this socket */
	rxrpc_discard_prealloc(rx);
	rxrpc_release_calls_on_socket(rx);
	flush_workqueue(rxrpc_workqueue);
	rxrpc_purge_queue(&sk->sk_receive_queue);

	rxrpc_unuse_local(rx->local);
	rx->local = NULL;
	key_put(rx->key);
	rx->key = NULL;
	key_put(rx->securities);
	rx->securities = NULL;
	sock_put(sk);

	_leave(" = 0");
	return 0;
}

/*
 * release an RxRPC BSD socket on close() or equivalent
 */
static int rxrpc_release(struct socket *sock)
{
	struct sock *sk = sock->sk;

	_enter("%p{%p}", sock, sk);

	if (!sk)
		return 0;

	sock->sk = NULL;

	return rxrpc_release_sock(sk);
}

/*
 * RxRPC network protocol
 */
static const struct proto_ops rxrpc_rpc_ops = {
	.family		= PF_RXRPC,
	.owner		= THIS_MODULE,
	.release	= rxrpc_release,
	.bind		= rxrpc_bind,
	.connect	= rxrpc_connect,
	.socketpair	= sock_no_socketpair,
	.accept		= sock_no_accept,
	.getname	= sock_no_getname,
	.poll		= rxrpc_poll,
	.ioctl		= sock_no_ioctl,
	.listen		= rxrpc_listen,
	.shutdown	= rxrpc_shutdown,
	.setsockopt	= rxrpc_setsockopt,
	.getsockopt	= rxrpc_getsockopt,
	.sendmsg	= rxrpc_sendmsg,
	.recvmsg	= rxrpc_recvmsg,
	.mmap		= sock_no_mmap,
	.sendpage	= sock_no_sendpage,
};

static struct proto rxrpc_proto = {
	.name		= "RXRPC",
	.owner		= THIS_MODULE,
	.obj_size	= sizeof(struct rxrpc_sock),
	.max_header	= sizeof(struct rxrpc_wire_header),
};

static const struct net_proto_family rxrpc_family_ops = {
	.family	= PF_RXRPC,
	.create = rxrpc_create,
	.owner	= THIS_MODULE,
};

/*
 * initialise and register the RxRPC protocol
 */
static int __init af_rxrpc_init(void)
{
	int ret = -1;
	unsigned int tmp;

	BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > FIELD_SIZEOF(struct sk_buff, cb));

	get_random_bytes(&tmp, sizeof(tmp));
	tmp &= 0x3fffffff;
	if (tmp == 0)
		tmp = 1;
	idr_set_cursor(&rxrpc_client_conn_ids, tmp);

	ret = -ENOMEM;
	rxrpc_call_jar = kmem_cache_create(
		"rxrpc_call_jar", sizeof(struct rxrpc_call), 0,
		SLAB_HWCACHE_ALIGN, NULL);
	if (!rxrpc_call_jar) {
		pr_notice("Failed to allocate call jar\n");
		goto error_call_jar;
	}

	rxrpc_workqueue = alloc_workqueue("krxrpcd", 0, 1);
	if (!rxrpc_workqueue) {
		pr_notice("Failed to allocate work queue\n");
		goto error_work_queue;
	}

	ret = rxrpc_init_security();
	if (ret < 0) {
		pr_crit("Cannot initialise security\n");
		goto error_security;
	}

	ret = register_pernet_subsys(&rxrpc_net_ops);
	if (ret)
		goto error_pernet;

	ret = proto_register(&rxrpc_proto, 1);
	if (ret < 0) {
		pr_crit("Cannot register protocol\n");
		goto error_proto;
	}

	ret = sock_register(&rxrpc_family_ops);
	if (ret < 0) {
		pr_crit("Cannot register socket family\n");
		goto error_sock;
	}

	ret = register_key_type(&key_type_rxrpc);
	if (ret < 0) {
		pr_crit("Cannot register client key type\n");
		goto error_key_type;
	}

	ret = register_key_type(&key_type_rxrpc_s);
	if (ret < 0) {
		pr_crit("Cannot register server key type\n");
		goto error_key_type_s;
	}

	ret = rxrpc_sysctl_init();
	if (ret < 0) {
		pr_crit("Cannot register sysctls\n");
		goto error_sysctls;
	}

	return 0;

error_sysctls:
	unregister_key_type(&key_type_rxrpc_s);
error_key_type_s:
	unregister_key_type(&key_type_rxrpc);
error_key_type:
	sock_unregister(PF_RXRPC);
error_sock:
	proto_unregister(&rxrpc_proto);
error_proto:
	unregister_pernet_subsys(&rxrpc_net_ops);
error_pernet:
	rxrpc_exit_security();
error_security:
	destroy_workqueue(rxrpc_workqueue);
error_work_queue:
	kmem_cache_destroy(rxrpc_call_jar);
error_call_jar:
	return ret;
}

/*
 * unregister the RxRPC protocol
 */
static void __exit af_rxrpc_exit(void)
{
	_enter("");
	rxrpc_sysctl_exit();
	unregister_key_type(&key_type_rxrpc_s);
	unregister_key_type(&key_type_rxrpc);
	sock_unregister(PF_RXRPC);
	proto_unregister(&rxrpc_proto);
	unregister_pernet_subsys(&rxrpc_net_ops);
	ASSERTCMP(atomic_read(&rxrpc_n_tx_skbs), ==, 0);
	ASSERTCMP(atomic_read(&rxrpc_n_rx_skbs), ==, 0);

	/* Make sure the local and peer records pinned by any dying connections
	 * are released.
	 */
	rcu_barrier();
	rxrpc_destroy_client_conn_ids();

	destroy_workqueue(rxrpc_workqueue);
	rxrpc_exit_security();
	kmem_cache_destroy(rxrpc_call_jar);
	_leave("");
}

module_init(af_rxrpc_init);
module_exit(af_rxrpc_exit);