summaryrefslogtreecommitdiffstats
path: root/net/caif/caif_socket.c
blob: 90317e7d10b4c03c680fe94e2680365f8f68c412 (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
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
/*
 * Copyright (C) ST-Ericsson AB 2010
 * Author:	Sjur Brendeland sjur.brandeland@stericsson.com
 *		Per Sigmond per.sigmond@stericsson.com
 * License terms: GNU General Public License (GPL) version 2
 */

#include <linux/fs.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/tcp.h>
#include <linux/uaccess.h>
#include <asm/atomic.h>

#include <linux/caif/caif_socket.h>
#include <net/caif/caif_layer.h>
#include <net/caif/caif_dev.h>
#include <net/caif/cfpkt.h>

MODULE_LICENSE("GPL");

#define CHNL_SKT_READ_QUEUE_HIGH 200
#define CHNL_SKT_READ_QUEUE_LOW 100

static int caif_sockbuf_size = 40000;
static atomic_t caif_nr_socks = ATOMIC_INIT(0);

#define CONN_STATE_OPEN_BIT	      1
#define CONN_STATE_PENDING_BIT	      2
#define CONN_STATE_PEND_DESTROY_BIT   3
#define CONN_REMOTE_SHUTDOWN_BIT      4

#define TX_FLOW_ON_BIT		      1
#define RX_FLOW_ON_BIT		      2

#define STATE_IS_OPEN(cf_sk) test_bit(CONN_STATE_OPEN_BIT,\
				    (void *) &(cf_sk)->conn_state)
#define STATE_IS_REMOTE_SHUTDOWN(cf_sk) test_bit(CONN_REMOTE_SHUTDOWN_BIT,\
				    (void *) &(cf_sk)->conn_state)
#define STATE_IS_PENDING(cf_sk) test_bit(CONN_STATE_PENDING_BIT,\
				       (void *) &(cf_sk)->conn_state)
#define STATE_IS_PENDING_DESTROY(cf_sk) test_bit(CONN_STATE_PEND_DESTROY_BIT,\
				       (void *) &(cf_sk)->conn_state)

#define SET_STATE_PENDING_DESTROY(cf_sk) set_bit(CONN_STATE_PEND_DESTROY_BIT,\
				    (void *) &(cf_sk)->conn_state)
#define SET_STATE_OPEN(cf_sk) set_bit(CONN_STATE_OPEN_BIT,\
				    (void *) &(cf_sk)->conn_state)
#define SET_STATE_CLOSED(cf_sk) clear_bit(CONN_STATE_OPEN_BIT,\
					(void *) &(cf_sk)->conn_state)
#define SET_PENDING_ON(cf_sk) set_bit(CONN_STATE_PENDING_BIT,\
				    (void *) &(cf_sk)->conn_state)
#define SET_PENDING_OFF(cf_sk) clear_bit(CONN_STATE_PENDING_BIT,\
				       (void *) &(cf_sk)->conn_state)
#define SET_REMOTE_SHUTDOWN(cf_sk) set_bit(CONN_REMOTE_SHUTDOWN_BIT,\
				    (void *) &(cf_sk)->conn_state)

#define SET_REMOTE_SHUTDOWN_OFF(dev) clear_bit(CONN_REMOTE_SHUTDOWN_BIT,\
				    (void *) &(dev)->conn_state)
#define RX_FLOW_IS_ON(cf_sk) test_bit(RX_FLOW_ON_BIT,\
				    (void *) &(cf_sk)->flow_state)
#define TX_FLOW_IS_ON(cf_sk) test_bit(TX_FLOW_ON_BIT,\
				    (void *) &(cf_sk)->flow_state)

#define SET_RX_FLOW_OFF(cf_sk) clear_bit(RX_FLOW_ON_BIT,\
				       (void *) &(cf_sk)->flow_state)
#define SET_RX_FLOW_ON(cf_sk) set_bit(RX_FLOW_ON_BIT,\
				    (void *) &(cf_sk)->flow_state)
#define SET_TX_FLOW_OFF(cf_sk) clear_bit(TX_FLOW_ON_BIT,\
				       (void *) &(cf_sk)->flow_state)
#define SET_TX_FLOW_ON(cf_sk) set_bit(TX_FLOW_ON_BIT,\
				    (void *) &(cf_sk)->flow_state)

#define SKT_READ_FLAG 0x01
#define SKT_WRITE_FLAG 0x02
static struct dentry *debugfsdir;
#include <linux/debugfs.h>

#ifdef CONFIG_DEBUG_FS
struct debug_fs_counter {
	atomic_t num_open;
	atomic_t num_close;
	atomic_t num_init;
	atomic_t num_init_resp;
	atomic_t num_init_fail_resp;
	atomic_t num_deinit;
	atomic_t num_deinit_resp;
	atomic_t num_remote_shutdown_ind;
	atomic_t num_tx_flow_off_ind;
	atomic_t num_tx_flow_on_ind;
	atomic_t num_rx_flow_off;
	atomic_t num_rx_flow_on;
	atomic_t skb_in_use;
	atomic_t skb_alloc;
	atomic_t skb_free;
};
static struct debug_fs_counter cnt;
#define	dbfs_atomic_inc(v) atomic_inc(v)
#define	dbfs_atomic_dec(v) atomic_dec(v)
#else
#define	dbfs_atomic_inc(v)
#define	dbfs_atomic_dec(v)
#endif

/* The AF_CAIF socket */
struct caifsock {
	/* NOTE: sk has to be the first member */
	struct sock sk;
	struct cflayer layer;
	char name[CAIF_LAYER_NAME_SZ];
	u32 conn_state;
	u32 flow_state;
	struct cfpktq *pktq;
	int file_mode;
	struct caif_connect_request conn_req;
	int read_queue_len;
	/* protect updates of read_queue_len */
	spinlock_t read_queue_len_lock;
	struct dentry *debugfs_socket_dir;
};

static void drain_queue(struct caifsock *cf_sk);

/* Packet Receive Callback function called from CAIF Stack */
static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
{
	struct caifsock *cf_sk;
	int read_queue_high;
	cf_sk = container_of(layr, struct caifsock, layer);

	if (!STATE_IS_OPEN(cf_sk)) {
		/*FIXME: This should be allowed finally!*/
		pr_debug("CAIF: %s(): called after close request\n", __func__);
		cfpkt_destroy(pkt);
		return 0;
	}
	/* NOTE: This function may be called in Tasklet context! */

	/* The queue has its own lock */
	cfpkt_queue(cf_sk->pktq, pkt, 0);

	spin_lock(&cf_sk->read_queue_len_lock);
	cf_sk->read_queue_len++;

	read_queue_high = (cf_sk->read_queue_len > CHNL_SKT_READ_QUEUE_HIGH);
	spin_unlock(&cf_sk->read_queue_len_lock);

	if (RX_FLOW_IS_ON(cf_sk) && read_queue_high) {
		dbfs_atomic_inc(&cnt.num_rx_flow_off);
		SET_RX_FLOW_OFF(cf_sk);

		/* Send flow off (NOTE: must not sleep) */
		pr_debug("CAIF: %s():"
			" sending flow OFF (queue len = %d)\n",
			__func__,
		     cf_sk->read_queue_len);
		caif_assert(cf_sk->layer.dn);
		caif_assert(cf_sk->layer.dn->ctrlcmd);

		(void) cf_sk->layer.dn->modemcmd(cf_sk->layer.dn,
					       CAIF_MODEMCMD_FLOW_OFF_REQ);
	}

	/* Signal reader that data is available. */

	wake_up_interruptible(cf_sk->sk.sk_sleep);

	return 0;
}

/* Packet Flow Control Callback function called from CAIF */
static void caif_sktflowctrl_cb(struct cflayer *layr,
				enum caif_ctrlcmd flow,
				int phyid)
{
	struct caifsock *cf_sk;

	/* NOTE: This function may be called in Tasklet context! */
	pr_debug("CAIF: %s(): flowctrl func called: %s.\n",
		      __func__,
		      flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
		      flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
		      flow == CAIF_CTRLCMD_INIT_RSP ? "INIT_RSP" :
		      flow == CAIF_CTRLCMD_DEINIT_RSP ? "DEINIT_RSP" :
		      flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "INIT_FAIL_RSP" :
		      flow ==
		      CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ? "REMOTE_SHUTDOWN" :
		      "UKNOWN CTRL COMMAND");

	if (layr == NULL)
		return;

	cf_sk = container_of(layr, struct caifsock, layer);

	switch (flow) {
	case CAIF_CTRLCMD_FLOW_ON_IND:
		dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
		/* Signal reader that data is available. */
		SET_TX_FLOW_ON(cf_sk);
		wake_up_interruptible(cf_sk->sk.sk_sleep);
		break;

	case CAIF_CTRLCMD_FLOW_OFF_IND:
		dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
		SET_TX_FLOW_OFF(cf_sk);
		break;

	case CAIF_CTRLCMD_INIT_RSP:
		dbfs_atomic_inc(&cnt.num_init_resp);
		/* Signal reader that data is available. */
		caif_assert(STATE_IS_OPEN(cf_sk));
		SET_PENDING_OFF(cf_sk);
		SET_TX_FLOW_ON(cf_sk);
		wake_up_interruptible(cf_sk->sk.sk_sleep);
		break;

	case CAIF_CTRLCMD_DEINIT_RSP:
		dbfs_atomic_inc(&cnt.num_deinit_resp);
		caif_assert(!STATE_IS_OPEN(cf_sk));
		SET_PENDING_OFF(cf_sk);
		if (!STATE_IS_PENDING_DESTROY(cf_sk)) {
			if (cf_sk->sk.sk_sleep != NULL)
				wake_up_interruptible(cf_sk->sk.sk_sleep);
		}
		dbfs_atomic_inc(&cnt.num_deinit);
		sock_put(&cf_sk->sk);
		break;

	case CAIF_CTRLCMD_INIT_FAIL_RSP:
		dbfs_atomic_inc(&cnt.num_init_fail_resp);
		caif_assert(STATE_IS_OPEN(cf_sk));
		SET_STATE_CLOSED(cf_sk);
		SET_PENDING_OFF(cf_sk);
		SET_TX_FLOW_OFF(cf_sk);
		wake_up_interruptible(cf_sk->sk.sk_sleep);
		break;

	case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
		dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
		SET_REMOTE_SHUTDOWN(cf_sk);
		/* Use sk_shutdown to indicate remote shutdown indication */
		cf_sk->sk.sk_shutdown |= RCV_SHUTDOWN;
		cf_sk->file_mode = 0;
		wake_up_interruptible(cf_sk->sk.sk_sleep);
		break;

	default:
		pr_debug("CAIF: %s(): Unexpected flow command %d\n",
			      __func__, flow);
	}
}

static void skb_destructor(struct sk_buff *skb)
{
	dbfs_atomic_inc(&cnt.skb_free);
	dbfs_atomic_dec(&cnt.skb_in_use);
}


static int caif_recvmsg(struct kiocb *iocb, struct socket *sock,
				struct msghdr *m, size_t buf_len, int flags)

{
	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	struct cfpkt *pkt = NULL;
	size_t len;
	int result;
	struct sk_buff *skb;
	ssize_t ret = -EIO;
	int read_queue_low;

	if (cf_sk == NULL) {
		pr_debug("CAIF: %s(): private_data not set!\n",
			      __func__);
		ret = -EBADFD;
		goto read_error;
	}

	/* Don't do multiple iovec entries yet */
	if (m->msg_iovlen != 1)
		return -EOPNOTSUPP;

	if (unlikely(!buf_len))
		return -EINVAL;

	lock_sock(&(cf_sk->sk));

	caif_assert(cf_sk->pktq);

	if (!STATE_IS_OPEN(cf_sk)) {
		/* Socket is closed or closing. */
		if (!STATE_IS_PENDING(cf_sk)) {
			pr_debug("CAIF: %s(): socket is closed (by remote)\n",
				 __func__);
			ret = -EPIPE;
		} else {
			pr_debug("CAIF: %s(): socket is closing..\n", __func__);
			ret = -EBADF;
		}
		goto read_error;
	}
	/* Socket is open or opening. */
	if (STATE_IS_PENDING(cf_sk)) {
		pr_debug("CAIF: %s(): socket is opening...\n", __func__);

		if (flags & MSG_DONTWAIT) {
			/* We can't block. */
			pr_debug("CAIF: %s():state pending and MSG_DONTWAIT\n",
				 __func__);
			ret = -EAGAIN;
			goto read_error;
		}

		/*
		 * Blocking mode; state is pending and we need to wait
		 * for its conclusion.
		 */
		release_sock(&cf_sk->sk);

		result =
		    wait_event_interruptible(*cf_sk->sk.sk_sleep,
					     !STATE_IS_PENDING(cf_sk));

		lock_sock(&(cf_sk->sk));

		if (result == -ERESTARTSYS) {
			pr_debug("CAIF: %s(): wait_event_interruptible"
				 " woken by a signal (1)", __func__);
			ret = -ERESTARTSYS;
			goto read_error;
		}
	}

	if (STATE_IS_REMOTE_SHUTDOWN(cf_sk) ||
		!STATE_IS_OPEN(cf_sk) ||
		STATE_IS_PENDING(cf_sk)) {

		pr_debug("CAIF: %s(): socket closed\n",
			__func__);
		ret = -ESHUTDOWN;
		goto read_error;
	}

	/*
	 * Block if we don't have any received buffers.
	 * The queue has its own lock.
	 */
	while ((pkt = cfpkt_qpeek(cf_sk->pktq)) == NULL) {

		if (flags & MSG_DONTWAIT) {
			pr_debug("CAIF: %s(): MSG_DONTWAIT\n", __func__);
			ret = -EAGAIN;
			goto read_error;
		}
		trace_printk("CAIF: %s() wait_event\n", __func__);

		/* Let writers in. */
		release_sock(&cf_sk->sk);

		/* Block reader until data arrives or socket is closed. */
		if (wait_event_interruptible(*cf_sk->sk.sk_sleep,
					cfpkt_qpeek(cf_sk->pktq)
					|| STATE_IS_REMOTE_SHUTDOWN(cf_sk)
					|| !STATE_IS_OPEN(cf_sk)) ==
		    -ERESTARTSYS) {
			pr_debug("CAIF: %s():"
				" wait_event_interruptible woken by "
				"a signal, signal_pending(current) = %d\n",
				__func__,
				signal_pending(current));
			return -ERESTARTSYS;
		}

		trace_printk("CAIF: %s() awake\n", __func__);
		if (STATE_IS_REMOTE_SHUTDOWN(cf_sk)) {
			pr_debug("CAIF: %s(): "
				 "received remote_shutdown indication\n",
				 __func__);
			ret = -ESHUTDOWN;
			goto read_error_no_unlock;
		}

		/* I want to be alone on cf_sk (except status and queue). */
		lock_sock(&(cf_sk->sk));

		if (!STATE_IS_OPEN(cf_sk)) {
			/* Someone closed the link, report error. */
			pr_debug("CAIF: %s(): remote end shutdown!\n",
				      __func__);
			ret = -EPIPE;
			goto read_error;
		}
	}

	/* The queue has its own lock. */
	len = cfpkt_getlen(pkt);

	/* Check max length that can be copied. */
	if (len <= buf_len)
		pkt = cfpkt_dequeue(cf_sk->pktq);
	else {
		pr_debug("CAIF: %s(): user buffer too small (%ld,%ld)\n",
			 __func__, (long) len, (long) buf_len);
		if (sock->type == SOCK_SEQPACKET) {
			ret = -EMSGSIZE;
			goto read_error;
		}
		len = buf_len;
	}


	spin_lock(&cf_sk->read_queue_len_lock);
	cf_sk->read_queue_len--;
	read_queue_low = (cf_sk->read_queue_len < CHNL_SKT_READ_QUEUE_LOW);
	spin_unlock(&cf_sk->read_queue_len_lock);

	if (!RX_FLOW_IS_ON(cf_sk) && read_queue_low) {
		dbfs_atomic_inc(&cnt.num_rx_flow_on);
		SET_RX_FLOW_ON(cf_sk);

		/* Send flow on. */
		pr_debug("CAIF: %s(): sending flow ON (queue len = %d)\n",
			 __func__, cf_sk->read_queue_len);
		caif_assert(cf_sk->layer.dn);
		caif_assert(cf_sk->layer.dn->ctrlcmd);
		(void) cf_sk->layer.dn->modemcmd(cf_sk->layer.dn,
					       CAIF_MODEMCMD_FLOW_ON_REQ);

		caif_assert(cf_sk->read_queue_len >= 0);
	}

	skb = cfpkt_tonative(pkt);
	result = skb_copy_datagram_iovec(skb, 0, m->msg_iov, len);
	skb_pull(skb, len);

	if (result) {
		pr_debug("CAIF: %s(): copy to_iovec failed\n", __func__);
		cfpkt_destroy(pkt);
		ret = -EFAULT;
		goto read_error;
	}

	/* Free packet and remove from queue */
	if (skb->len == 0)
		skb_free_datagram(sk, skb);

	/* Let the others in. */
	release_sock(&cf_sk->sk);
	return len;

read_error:
	release_sock(&cf_sk->sk);
read_error_no_unlock:
	return ret;
}

/* Send a signal as a consequence of sendmsg, sendto or caif_sendmsg. */
static int caif_sendmsg(struct kiocb *kiocb, struct socket *sock,
			struct msghdr *msg, size_t len)
{

	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	size_t payload_size = msg->msg_iov->iov_len;
	struct cfpkt *pkt = NULL;
	struct caif_payload_info info;
	unsigned char *txbuf;
	ssize_t ret = -EIO;
	int result;
	struct sk_buff *skb;
	caif_assert(msg->msg_iovlen == 1);

	if (cf_sk == NULL) {
		pr_debug("CAIF: %s(): private_data not set!\n",
			      __func__);
		ret = -EBADFD;
		goto write_error_no_unlock;
	}

	if (unlikely(msg->msg_iov->iov_base == NULL)) {
		pr_warning("CAIF: %s(): Buffer is NULL.\n", __func__);
		ret = -EINVAL;
		goto write_error_no_unlock;
	}

	if (payload_size > CAIF_MAX_PAYLOAD_SIZE) {
		pr_debug("CAIF: %s(): buffer too long\n", __func__);
		if (sock->type == SOCK_SEQPACKET) {
			ret = -EINVAL;
			goto write_error_no_unlock;
		}
		payload_size = CAIF_MAX_PAYLOAD_SIZE;
	}

	/* I want to be alone on cf_sk (except status and queue) */
	lock_sock(&(cf_sk->sk));

	caif_assert(cf_sk->pktq);

	if (!STATE_IS_OPEN(cf_sk)) {
		/* Socket is closed or closing */
		if (!STATE_IS_PENDING(cf_sk)) {
			pr_debug("CAIF: %s(): socket is closed (by remote)\n",
				 __func__);
			ret = -EPIPE;
		} else {
			pr_debug("CAIF: %s(): socket is closing...\n",
				 __func__);
			ret = -EBADF;
		}
		goto write_error;
	}

	/* Socket is open or opening */
	if (STATE_IS_PENDING(cf_sk)) {
		pr_debug("CAIF: %s(): socket is opening...\n", __func__);

		if (msg->msg_flags & MSG_DONTWAIT) {
			/* We can't block */
			trace_printk("CAIF: %s():state pending:"
				     "state=MSG_DONTWAIT\n", __func__);
			ret = -EAGAIN;
			goto write_error;
		}
		/* Let readers in */
		release_sock(&cf_sk->sk);

		/*
		 * Blocking mode; state is pending and we need to wait
		 * for its conclusion.
		 */
		result =
		    wait_event_interruptible(*cf_sk->sk.sk_sleep,
					     !STATE_IS_PENDING(cf_sk));
		/* I want to be alone on cf_sk (except status and queue) */
		lock_sock(&(cf_sk->sk));

		if (result == -ERESTARTSYS) {
			pr_debug("CAIF: %s(): wait_event_interruptible"
				 " woken by a signal (1)", __func__);
			ret = -ERESTARTSYS;
			goto write_error;
		}
	}
	if (STATE_IS_REMOTE_SHUTDOWN(cf_sk) ||
		!STATE_IS_OPEN(cf_sk) ||
		STATE_IS_PENDING(cf_sk)) {

		pr_debug("CAIF: %s(): socket closed\n",
			__func__);
		ret = -ESHUTDOWN;
		goto write_error;
	}

	if (!TX_FLOW_IS_ON(cf_sk)) {

		/* Flow is off. Check non-block flag */
		if (msg->msg_flags & MSG_DONTWAIT) {
			trace_printk("CAIF: %s(): MSG_DONTWAIT and tx flow off",
				 __func__);
			ret = -EAGAIN;
			goto write_error;
		}

		/* release lock before waiting */
		release_sock(&cf_sk->sk);

		/* Wait until flow is on or socket is closed */
		if (wait_event_interruptible(*cf_sk->sk.sk_sleep,
					TX_FLOW_IS_ON(cf_sk)
					|| !STATE_IS_OPEN(cf_sk)
					|| STATE_IS_REMOTE_SHUTDOWN(cf_sk)
					) == -ERESTARTSYS) {
			pr_debug("CAIF: %s():"
				 " wait_event_interruptible woken by a signal",
				 __func__);
			ret = -ERESTARTSYS;
			goto write_error_no_unlock;
		}

		/* I want to be alone on cf_sk (except status and queue) */
		lock_sock(&(cf_sk->sk));

		if (!STATE_IS_OPEN(cf_sk)) {
			/* someone closed the link, report error */
			pr_debug("CAIF: %s(): remote end shutdown!\n",
				      __func__);
			ret = -EPIPE;
			goto write_error;
		}

		if (STATE_IS_REMOTE_SHUTDOWN(cf_sk)) {
			pr_debug("CAIF: %s(): "
				 "received remote_shutdown indication\n",
				 __func__);
			ret = -ESHUTDOWN;
			goto write_error;
		}
	}

	pkt = cfpkt_create(payload_size);
	skb = (struct sk_buff *)pkt;
	skb->destructor = skb_destructor;
	skb->sk = sk;
	dbfs_atomic_inc(&cnt.skb_alloc);
	dbfs_atomic_inc(&cnt.skb_in_use);
	if (cfpkt_raw_append(pkt, (void **) &txbuf, payload_size) < 0) {
		pr_debug("CAIF: %s(): cfpkt_raw_append failed\n", __func__);
		cfpkt_destroy(pkt);
		ret = -EINVAL;
		goto write_error;
	}

	/* Copy data into buffer. */
	if (copy_from_user(txbuf, msg->msg_iov->iov_base, payload_size)) {
		pr_debug("CAIF: %s(): copy_from_user returned non zero.\n",
			 __func__);
		cfpkt_destroy(pkt);
		ret = -EINVAL;
		goto write_error;
	}
	memset(&info, 0, sizeof(info));

	/* Send the packet down the stack. */
	caif_assert(cf_sk->layer.dn);
	caif_assert(cf_sk->layer.dn->transmit);

	do {
		ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);

		if (likely((ret >= 0) || (ret != -EAGAIN)))
			break;

		/* EAGAIN - retry */
		if (msg->msg_flags & MSG_DONTWAIT) {
			pr_debug("CAIF: %s(): NONBLOCK and transmit failed,"
				 " error = %ld\n", __func__, (long) ret);
			ret = -EAGAIN;
			goto write_error;
		}

		/* Let readers in */
		release_sock(&cf_sk->sk);

		/* Wait until flow is on or socket is closed */
		if (wait_event_interruptible(*cf_sk->sk.sk_sleep,
					TX_FLOW_IS_ON(cf_sk)
					|| !STATE_IS_OPEN(cf_sk)
					|| STATE_IS_REMOTE_SHUTDOWN(cf_sk)
					) == -ERESTARTSYS) {
			pr_debug("CAIF: %s(): wait_event_interruptible"
				 " woken by a signal", __func__);
			ret = -ERESTARTSYS;
			goto write_error_no_unlock;
		}

		/* I want to be alone on cf_sk (except status and queue) */
		lock_sock(&(cf_sk->sk));

	} while (ret == -EAGAIN);

	if (ret < 0) {
		cfpkt_destroy(pkt);
		pr_debug("CAIF: %s(): transmit failed, error = %ld\n",
			 __func__, (long) ret);

		goto write_error;
	}

	release_sock(&cf_sk->sk);
	return payload_size;

write_error:
	release_sock(&cf_sk->sk);
write_error_no_unlock:
	return ret;
}

static unsigned int caif_poll(struct file *file, struct socket *sock,
						poll_table *wait)
{
	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	u32 mask = 0;
	poll_wait(file, sk_sleep(sk), wait);
	lock_sock(&(cf_sk->sk));
	if (!STATE_IS_OPEN(cf_sk)) {
		if (!STATE_IS_PENDING(cf_sk))
			mask |= POLLHUP;
	} else {
		if (cfpkt_qpeek(cf_sk->pktq) != NULL)
			mask |= (POLLIN | POLLRDNORM);
		if (TX_FLOW_IS_ON(cf_sk))
			mask |= (POLLOUT | POLLWRNORM);
	}
	release_sock(&cf_sk->sk);
	trace_printk("CAIF: %s(): poll mask=0x%04x\n",
		      __func__, mask);
	return mask;
}

static void drain_queue(struct caifsock *cf_sk)
{
	struct cfpkt *pkt = NULL;

	/* Empty the queue */
	do {
		/* The queue has its own lock */
		if (!cf_sk->pktq)
			break;

		pkt = cfpkt_dequeue(cf_sk->pktq);
		if (!pkt)
			break;
		pr_debug("CAIF: %s(): freeing packet from read queue\n",
			 __func__);
		cfpkt_destroy(pkt);

	} while (1);

	cf_sk->read_queue_len = 0;
}

static int setsockopt(struct socket *sock,
			int lvl, int opt, char __user *ov, unsigned int ol)
{
	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
	int prio, linksel;
	struct ifreq ifreq;

	if (STATE_IS_OPEN(cf_sk)) {
		pr_debug("CAIF: %s(): setsockopt "
			 "cannot be done on a connected socket\n",
			 __func__);
		return -ENOPROTOOPT;
	}
	switch (opt) {
	case CAIFSO_LINK_SELECT:
		if (ol < sizeof(int)) {
			pr_debug("CAIF: %s(): setsockopt"
				 " CAIFSO_CHANNEL_CONFIG bad size\n", __func__);
			return -EINVAL;
		}
		if (lvl != SOL_CAIF)
			goto bad_sol;
		if (copy_from_user(&linksel, ov, sizeof(int)))
			return -EINVAL;
		lock_sock(&(cf_sk->sk));
		cf_sk->conn_req.link_selector = linksel;
		release_sock(&cf_sk->sk);
		return 0;

	case SO_PRIORITY:
		if (lvl != SOL_SOCKET)
			goto bad_sol;
		if (ol < sizeof(int)) {
			pr_debug("CAIF: %s(): setsockopt"
				 " SO_PRIORITY bad size\n", __func__);
			return -EINVAL;
		}
		if (copy_from_user(&prio, ov, sizeof(int)))
			return -EINVAL;
		lock_sock(&(cf_sk->sk));
		cf_sk->conn_req.priority = prio;
		pr_debug("CAIF: %s(): Setting sockopt priority=%d\n", __func__,
			cf_sk->conn_req.priority);
		release_sock(&cf_sk->sk);
		return 0;

	case SO_BINDTODEVICE:
		if (lvl != SOL_SOCKET)
			goto bad_sol;
		if (ol < sizeof(struct ifreq)) {
			pr_debug("CAIF: %s(): setsockopt"
				 " SO_PRIORITY bad size\n", __func__);
			return -EINVAL;
		}
		if (copy_from_user(&ifreq, ov, sizeof(ifreq)))
			return -EFAULT;
		lock_sock(&(cf_sk->sk));
		strncpy(cf_sk->conn_req.link_name, ifreq.ifr_name,
			sizeof(cf_sk->conn_req.link_name));
		cf_sk->conn_req.link_name
			[sizeof(cf_sk->conn_req.link_name)-1] = 0;
		release_sock(&cf_sk->sk);
		return 0;

	case CAIFSO_REQ_PARAM:
		if (lvl != SOL_CAIF)
			goto bad_sol;
		if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
			return -ENOPROTOOPT;
		if (ol > sizeof(cf_sk->conn_req.param.data))
			goto req_param_bad_size;

		lock_sock(&(cf_sk->sk));
		cf_sk->conn_req.param.size = ol;
		if (copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
			release_sock(&cf_sk->sk);
req_param_bad_size:
			pr_debug("CAIF: %s(): setsockopt"
				 " CAIFSO_CHANNEL_CONFIG bad size\n", __func__);
			return -EINVAL;
		}

		release_sock(&cf_sk->sk);
		return 0;

	default:
		pr_debug("CAIF: %s(): unhandled option %d\n", __func__, opt);
		return -EINVAL;
	}

	return 0;
bad_sol:
	pr_debug("CAIF: %s(): setsockopt bad level\n", __func__);
	return -ENOPROTOOPT;

}

static int caif_connect(struct socket *sock, struct sockaddr *uservaddr,
	       int sockaddr_len, int flags)
{
	struct caifsock *cf_sk = NULL;
	int result = -1;
	int mode = 0;
	int ret = -EIO;
	struct sock *sk = sock->sk;
	BUG_ON(sk == NULL);

	cf_sk = container_of(sk, struct caifsock, sk);

	trace_printk("CAIF: %s(): cf_sk=%p OPEN=%d, TX_FLOW=%d, RX_FLOW=%d\n",
		 __func__, cf_sk,
		STATE_IS_OPEN(cf_sk),
		TX_FLOW_IS_ON(cf_sk), RX_FLOW_IS_ON(cf_sk));


	if (sock->type == SOCK_SEQPACKET || sock->type == SOCK_STREAM)
		sock->state	= SS_CONNECTING;
	else
		goto out;

	/* I want to be alone on cf_sk (except status and queue) */
	lock_sock(&(cf_sk->sk));

	if (sockaddr_len != sizeof(struct sockaddr_caif)) {
		pr_debug("CAIF: %s(): Bad address len (%ld,%lu)\n",
			 __func__, (long) sockaddr_len,
			(long unsigned) sizeof(struct sockaddr_caif));
		ret = -EINVAL;
		goto open_error;
	}

	if (uservaddr->sa_family != AF_CAIF) {
		pr_debug("CAIF: %s(): Bad address family (%d)\n",
			 __func__, uservaddr->sa_family);
		ret = -EAFNOSUPPORT;
		goto open_error;
	}

	memcpy(&cf_sk->conn_req.sockaddr, uservaddr,
		sizeof(struct sockaddr_caif));

	dbfs_atomic_inc(&cnt.num_open);
	mode = SKT_READ_FLAG | SKT_WRITE_FLAG;

	/* If socket is not open, make sure socket is in fully closed state */
	if (!STATE_IS_OPEN(cf_sk)) {
		/* Has link close response been received (if we ever sent it)?*/
		if (STATE_IS_PENDING(cf_sk)) {
			/*
			 * Still waiting for close response from remote.
			 * If opened non-blocking, report "would block"
			 */
			if (flags & O_NONBLOCK) {
				pr_debug("CAIF: %s(): O_NONBLOCK"
					" && close pending\n", __func__);
				ret = -EAGAIN;
				goto open_error;
			}

			pr_debug("CAIF: %s(): Wait for close response"
				 " from remote...\n", __func__);

			release_sock(&cf_sk->sk);

			/*
			 * Blocking mode; close is pending and we need to wait
			 * for its conclusion.
			 */
			result =
			    wait_event_interruptible(*cf_sk->sk.sk_sleep,
						     !STATE_IS_PENDING(cf_sk));

			lock_sock(&(cf_sk->sk));
			if (result == -ERESTARTSYS) {
				pr_debug("CAIF: %s(): wait_event_interruptible"
					 "woken by a signal (1)", __func__);
				ret = -ERESTARTSYS;
				goto open_error;
			}
		}
	}

	/* socket is now either closed, pending open or open */
	if (STATE_IS_OPEN(cf_sk) && !STATE_IS_PENDING(cf_sk)) {
		/* Open */
		pr_debug("CAIF: %s(): Socket is already opened (cf_sk=%p)"
			" check access f_flags = 0x%x file_mode = 0x%x\n",
			 __func__, cf_sk, mode, cf_sk->file_mode);

	} else {
		/* We are closed or pending open.
		 * If closed:	    send link setup
		 * If pending open: link setup already sent (we could have been
		 *		    interrupted by a signal last time)
		 */
		if (!STATE_IS_OPEN(cf_sk)) {
			/* First opening of file; connect lower layers: */
			/* Drain queue (very unlikely) */
			drain_queue(cf_sk);

			cf_sk->layer.receive = caif_sktrecv_cb;
			SET_STATE_OPEN(cf_sk);
			SET_PENDING_ON(cf_sk);

			/* Register this channel. */
			result =
				caif_connect_client(&cf_sk->conn_req,
							&cf_sk->layer);
			if (result < 0) {
				pr_debug("CAIF: %s(): can't register channel\n",
					__func__);
				ret = -EIO;
				SET_STATE_CLOSED(cf_sk);
				SET_PENDING_OFF(cf_sk);
				goto open_error;
			}
			dbfs_atomic_inc(&cnt.num_init);
		}

		/* If opened non-blocking, report "success".
		 */
		if (flags & O_NONBLOCK) {
			pr_debug("CAIF: %s(): O_NONBLOCK success\n",
				 __func__);
			ret = -EINPROGRESS;
			cf_sk->sk.sk_err = -EINPROGRESS;
			goto open_error;
		}

		trace_printk("CAIF: %s(): Wait for connect response\n",
			     __func__);

		/* release lock before waiting */
		release_sock(&cf_sk->sk);

		result =
		    wait_event_interruptible(*cf_sk->sk.sk_sleep,
					     !STATE_IS_PENDING(cf_sk));

		lock_sock(&(cf_sk->sk));

		if (result == -ERESTARTSYS) {
			pr_debug("CAIF: %s(): wait_event_interruptible"
				 "woken by a signal (2)", __func__);
			ret = -ERESTARTSYS;
			goto open_error;
		}

		if (!STATE_IS_OPEN(cf_sk)) {
			/* Lower layers said "no" */
			pr_debug("CAIF: %s(): Closed received\n", __func__);
			ret = -EPIPE;
			goto open_error;
		}

		trace_printk("CAIF: %s(): Connect received\n", __func__);
	}
	/* Open is ok */
	cf_sk->file_mode |= mode;

	trace_printk("CAIF: %s(): Connected - file mode = %x\n",
		  __func__, cf_sk->file_mode);

	release_sock(&cf_sk->sk);
	return 0;
open_error:
	sock->state	= SS_UNCONNECTED;
	release_sock(&cf_sk->sk);
out:
	return ret;
}

static int caif_shutdown(struct socket *sock, int how)
{
	struct caifsock *cf_sk = NULL;
	int result = 0;
	int tx_flow_state_was_on;
	struct sock *sk = sock->sk;

	trace_printk("CAIF: %s(): enter\n", __func__);
	pr_debug("f_flags=%x\n", sock->file->f_flags);

	if (how != SHUT_RDWR)
		return -EOPNOTSUPP;

	cf_sk = container_of(sk, struct caifsock, sk);
	if (cf_sk == NULL) {
		pr_debug("CAIF: %s(): COULD NOT FIND SOCKET\n", __func__);
		return -EBADF;
	}

	/* I want to be alone on cf_sk (except status queue) */
	lock_sock(&(cf_sk->sk));
	sock_hold(&cf_sk->sk);

	/* IS_CLOSED have double meaning:
	 * 1) Spontanous Remote Shutdown Request.
	 * 2) Ack on a channel teardown(disconnect)
	 * Must clear bit in case we previously received
	 * remote shudown request.
	 */
	if (STATE_IS_OPEN(cf_sk) && !STATE_IS_PENDING(cf_sk)) {
		SET_STATE_CLOSED(cf_sk);
		SET_PENDING_ON(cf_sk);
		tx_flow_state_was_on = TX_FLOW_IS_ON(cf_sk);
		SET_TX_FLOW_OFF(cf_sk);

		/* Hold the socket until DEINIT_RSP is received */
		sock_hold(&cf_sk->sk);
		result = caif_disconnect_client(&cf_sk->layer);

		if (result < 0) {
			pr_debug("CAIF: %s(): "
					"caif_disconnect_client() failed\n",
					 __func__);
			SET_STATE_CLOSED(cf_sk);
			SET_PENDING_OFF(cf_sk);
			SET_TX_FLOW_OFF(cf_sk);
			release_sock(&cf_sk->sk);
			sock_put(&cf_sk->sk);
			return -EIO;
		}

	}
	if (STATE_IS_REMOTE_SHUTDOWN(cf_sk)) {
		SET_PENDING_OFF(cf_sk);
		SET_REMOTE_SHUTDOWN_OFF(cf_sk);
	}

	/*
	 * Socket is no longer in state pending close,
	 * and we can release the reference.
	 */

	dbfs_atomic_inc(&cnt.num_close);
	drain_queue(cf_sk);
	SET_RX_FLOW_ON(cf_sk);
	cf_sk->file_mode = 0;
	sock_put(&cf_sk->sk);
	release_sock(&cf_sk->sk);
	if (!result && (sock->file->f_flags & O_NONBLOCK)) {
		pr_debug("nonblocking shutdown returing -EAGAIN\n");
		return -EAGAIN;
	} else
		return result;
}

static ssize_t caif_sock_no_sendpage(struct socket *sock,
				     struct page *page,
				     int offset, size_t size, int flags)
{
	return -EOPNOTSUPP;
}

/* This function is called as part of close. */
static int caif_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	struct caifsock *cf_sk = NULL;
	int res;
	caif_assert(sk != NULL);
	cf_sk = container_of(sk, struct caifsock, sk);

	if (cf_sk->debugfs_socket_dir != NULL)
		debugfs_remove_recursive(cf_sk->debugfs_socket_dir);

	res = caif_shutdown(sock, SHUT_RDWR);
	if (res && res != -EINPROGRESS)
		return res;

	/*
	 * FIXME: Shutdown should probably be possible to do async
	 * without flushing queues, allowing reception of frames while
	 * waiting for DEINIT_IND.
	 * Release should always block, to allow secure decoupling of
	 * CAIF stack.
	 */
	if (!(sock->file->f_flags & O_NONBLOCK)) {
		res = wait_event_interruptible(*cf_sk->sk.sk_sleep,
						!STATE_IS_PENDING(cf_sk));

		if (res == -ERESTARTSYS) {
			pr_debug("CAIF: %s(): wait_event_interruptible"
				"woken by a signal (1)", __func__);
		}
	}
	lock_sock(&(cf_sk->sk));

	sock->sk = NULL;

	/* Detach the socket from its process context by making it orphan. */
	sock_orphan(sk);

	/*
	 * Setting SHUTDOWN_MASK means that both send and receive are shutdown
	 * for the socket.
	 */
	sk->sk_shutdown = SHUTDOWN_MASK;

	/*
	 * Set the socket state to closed, the TCP_CLOSE macro is used when
	 * closing any socket.
	 */

	/* Flush out this sockets receive queue. */
	drain_queue(cf_sk);

	/* Finally release the socket. */
	SET_STATE_PENDING_DESTROY(cf_sk);

	release_sock(&cf_sk->sk);

	sock_put(sk);

	/*
	 * The rest of the cleanup will be handled from the
	 * caif_sock_destructor
	 */
	return res;
}

static const struct proto_ops caif_ops = {
	.family = PF_CAIF,
	.owner = THIS_MODULE,
	.release = caif_release,
	.bind = sock_no_bind,
	.connect = caif_connect,
	.socketpair = sock_no_socketpair,
	.accept = sock_no_accept,
	.getname = sock_no_getname,
	.poll = caif_poll,
	.ioctl = sock_no_ioctl,
	.listen = sock_no_listen,
	.shutdown = caif_shutdown,
	.setsockopt = setsockopt,
	.getsockopt = sock_no_getsockopt,
	.sendmsg = caif_sendmsg,
	.recvmsg = caif_recvmsg,
	.mmap = sock_no_mmap,
	.sendpage = caif_sock_no_sendpage,
};

/* This function is called when a socket is finally destroyed. */
static void caif_sock_destructor(struct sock *sk)
{
	struct caifsock *cf_sk = NULL;
	cf_sk = container_of(sk, struct caifsock, sk);
	/* Error checks. */
	caif_assert(!atomic_read(&sk->sk_wmem_alloc));
	caif_assert(sk_unhashed(sk));
	caif_assert(!sk->sk_socket);
	if (!sock_flag(sk, SOCK_DEAD)) {
		pr_debug("CAIF: %s(): 0x%p", __func__, sk);
		return;
	}

	if (STATE_IS_OPEN(cf_sk)) {
		pr_debug("CAIF: %s(): socket is opened (cf_sk=%p)"
			 " file_mode = 0x%x\n", __func__,
			 cf_sk, cf_sk->file_mode);
		return;
	}
	drain_queue(cf_sk);
	kfree(cf_sk->pktq);

	trace_printk("CAIF: %s(): caif_sock_destructor: Removing socket %s\n",
		__func__, cf_sk->name);
	atomic_dec(&caif_nr_socks);
}

static int caif_create(struct net *net, struct socket *sock, int protocol,
		       int kern)
{
	struct sock *sk = NULL;
	struct caifsock *cf_sk = NULL;
	int result = 0;
	static struct proto prot = {.name = "PF_CAIF",
		.owner = THIS_MODULE,
		.obj_size = sizeof(struct caifsock),
	};

	/*
	 * The sock->type specifies the socket type to use.
	 * in SEQPACKET mode packet boundaries are enforced.
	 */
	if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM)
		return -ESOCKTNOSUPPORT;

	if (net != &init_net)
		return -EAFNOSUPPORT;

	if (protocol < 0 || protocol >= CAIFPROTO_MAX)
		return -EPROTONOSUPPORT;
	/*
	 * Set the socket state to unconnected.	 The socket state is really
	 * not used at all in the net/core or socket.c but the
	 * initialization makes sure that sock->state is not uninitialized.
	 */
	sock->state = SS_UNCONNECTED;

	sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
	if (!sk)
		return -ENOMEM;

	cf_sk = container_of(sk, struct caifsock, sk);

	/* Store the protocol */
	sk->sk_protocol = (unsigned char) protocol;

	spin_lock_init(&cf_sk->read_queue_len_lock);

	/* Fill in some information concerning the misc socket. */
	snprintf(cf_sk->name, sizeof(cf_sk->name), "cf_sk%d",
		atomic_read(&caif_nr_socks));

	/*
	 * Lock in order to try to stop someone from opening the socket
	 * too early.
	 */
	lock_sock(&(cf_sk->sk));

	/* Initialize the nozero default sock structure data. */
	sock_init_data(sock, sk);
	sock->ops = &caif_ops;
	sk->sk_destruct = caif_sock_destructor;
	sk->sk_sndbuf = caif_sockbuf_size;
	sk->sk_rcvbuf = caif_sockbuf_size;

	cf_sk->pktq = cfpktq_create();

	if (!cf_sk->pktq) {
		pr_err("CAIF: %s(): queue create failed.\n", __func__);
		result = -ENOMEM;
		release_sock(&cf_sk->sk);
		goto err_failed;
	}
	cf_sk->layer.ctrlcmd = caif_sktflowctrl_cb;
	SET_STATE_CLOSED(cf_sk);
	SET_PENDING_OFF(cf_sk);
	SET_TX_FLOW_OFF(cf_sk);
	SET_RX_FLOW_ON(cf_sk);

	/* Set default options on configuration */
	cf_sk->conn_req.priority = CAIF_PRIO_NORMAL;
	cf_sk->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
	cf_sk->conn_req.protocol = protocol;
	/* Increase the number of sockets created. */
	atomic_inc(&caif_nr_socks);
	if (!IS_ERR(debugfsdir)) {
		cf_sk->debugfs_socket_dir =
			debugfs_create_dir(cf_sk->name, debugfsdir);
		debugfs_create_u32("conn_state", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir, &cf_sk->conn_state);
		debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
		debugfs_create_u32("read_queue_len", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir,
				(u32 *) &cf_sk->read_queue_len);
		debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
				cf_sk->debugfs_socket_dir,
				(u32 *) &cf_sk->layer.id);
	}
	release_sock(&cf_sk->sk);
	return 0;
err_failed:
	sk_free(sk);
	return result;
}

static struct net_proto_family caif_family_ops = {
	.family = PF_CAIF,
	.create = caif_create,
	.owner = THIS_MODULE,
};

static int af_caif_init(void)
{
	int err;
	err = sock_register(&caif_family_ops);

	if (!err)
		return err;

	return 0;
}

static int __init caif_sktinit_module(void)
{
	int stat;
#ifdef CONFIG_DEBUG_FS
	debugfsdir = debugfs_create_dir("chnl_skt", NULL);
	if (!IS_ERR(debugfsdir)) {
		debugfs_create_u32("skb_inuse", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.skb_in_use);
		debugfs_create_u32("skb_alloc", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.skb_alloc);
		debugfs_create_u32("skb_free", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.skb_free);
		debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &caif_nr_socks);
		debugfs_create_u32("num_open", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_open);
		debugfs_create_u32("num_close", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_close);
		debugfs_create_u32("num_init", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_init);
		debugfs_create_u32("num_init_resp", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_init_resp);
		debugfs_create_u32("num_init_fail_resp", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_init_fail_resp);
		debugfs_create_u32("num_deinit", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_deinit);
		debugfs_create_u32("num_deinit_resp", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_deinit_resp);
		debugfs_create_u32("num_remote_shutdown_ind",
				S_IRUSR | S_IWUSR, debugfsdir,
				(u32 *) &cnt.num_remote_shutdown_ind);
		debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_tx_flow_off_ind);
		debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_tx_flow_on_ind);
		debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_rx_flow_off);
		debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
				debugfsdir,
				(u32 *) &cnt.num_rx_flow_on);
	}
#endif
	stat = af_caif_init();
	if (stat) {
		pr_err("CAIF: %s(): Failed to initialize CAIF socket layer.",
		       __func__);
		return stat;
	}
	return 0;
}

static void __exit caif_sktexit_module(void)
{
	sock_unregister(PF_CAIF);
	if (debugfsdir != NULL)
		debugfs_remove_recursive(debugfsdir);
}

module_init(caif_sktinit_module);
module_exit(caif_sktexit_module);