summaryrefslogtreecommitdiffstats
path: root/src/nvme/fabrics.c
blob: 3c32e2715c9373edb6e3a54b975b12ab71913d40 (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
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
// SPDX-License-Identifier: LGPL-2.1-or-later
/*
 * This file is part of libnvme.
 * Copyright (c) 2020 Western Digital Corporation or its affiliates.
 *
 * Authors: Keith Busch <keith.busch@wdc.com>
 * 	    Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
 */

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <dirent.h>
#include <inttypes.h>

#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <net/if.h>

#include <ccan/endian/endian.h>
#include <ccan/list/list.h>
#include <ccan/array_size/array_size.h>

#include "fabrics.h"
#include "linux.h"
#include "ioctl.h"
#include "util.h"
#include "log.h"
#include "private.h"

#define NVMF_HOSTID_SIZE	37

#define NVMF_HOSTNQN_FILE	SYSCONFDIR "/nvme/hostnqn"
#define NVMF_HOSTID_FILE	SYSCONFDIR "/nvme/hostid"

const char *nvmf_dev = "/dev/nvme-fabrics";

/**
 * strchomp() - Strip trailing white space
 * @str: String to strip
 * @max: Maximum length of string
 */
static void strchomp(char *str, int max)
{
	int i;

	for (i = max - 1; i >= 0; i--) {
		if (str[i] != '\0' && str[i] != ' ')
			return;
		else
			str[i] = '\0';
	}
}

const char *arg_str(const char * const *strings,
		size_t array_size, size_t idx)
{
	if (idx < array_size && strings[idx])
		return strings[idx];
	return "unrecognized";
}

const char * const trtypes[] = {
	[NVMF_TRTYPE_RDMA]	= "rdma",
	[NVMF_TRTYPE_FC]	= "fc",
	[NVMF_TRTYPE_TCP]	= "tcp",
	[NVMF_TRTYPE_LOOP]	= "loop",
};

const char *nvmf_trtype_str(__u8 trtype)
{
	return arg_str(trtypes, ARRAY_SIZE(trtypes), trtype);
}

static const char * const adrfams[] = {
	[NVMF_ADDR_FAMILY_PCI]	= "pci",
	[NVMF_ADDR_FAMILY_IP4]	= "ipv4",
	[NVMF_ADDR_FAMILY_IP6]	= "ipv6",
	[NVMF_ADDR_FAMILY_IB]	= "infiniband",
	[NVMF_ADDR_FAMILY_FC]	= "fibre-channel",
};

const char *nvmf_adrfam_str(__u8 adrfam)
{
	return arg_str(adrfams, ARRAY_SIZE(adrfams), adrfam);
}

static const char * const subtypes[] = {
	[NVME_NQN_DISC]		= "discovery subsystem referral",
	[NVME_NQN_NVME]		= "nvme subsystem",
	[NVME_NQN_CURR]		= "current discovery subsystem",
};

const char *nvmf_subtype_str(__u8 subtype)
{
	return arg_str(subtypes, ARRAY_SIZE(subtypes), subtype);
}

static const char * const treqs[] = {
	[NVMF_TREQ_NOT_SPECIFIED]	= "not specified",
	[NVMF_TREQ_REQUIRED]		= "required",
	[NVMF_TREQ_NOT_REQUIRED]	= "not required",
	[NVMF_TREQ_NOT_SPECIFIED |
	 NVMF_TREQ_DISABLE_SQFLOW]	= "not specified, "
				"sq flow control disable supported",
	[NVMF_TREQ_REQUIRED |
	 NVMF_TREQ_DISABLE_SQFLOW]	= "required, "
				"sq flow control disable supported",
	[NVMF_TREQ_NOT_REQUIRED |
	 NVMF_TREQ_DISABLE_SQFLOW]	= "not required, "
				"sq flow control disable supported",
};

const char *nvmf_treq_str(__u8 treq)
{
	return arg_str(treqs, ARRAY_SIZE(treqs), treq);
}

static const char * const eflags_strings[] = {
	[NVMF_DISC_EFLAGS_NONE]		= "none",
	[NVMF_DISC_EFLAGS_EPCSD]	= "explicit discovery connections",
	[NVMF_DISC_EFLAGS_DUPRETINFO]	= "duplicate discovery information",
	[NVMF_DISC_EFLAGS_EPCSD |
	 NVMF_DISC_EFLAGS_DUPRETINFO]	= "explicit discovery connections, "
					  "duplicate discovery information",
	[NVMF_DISC_EFLAGS_NCC]		= "no cdc connectivity",
	[NVMF_DISC_EFLAGS_EPCSD |
	 NVMF_DISC_EFLAGS_NCC]		= "explicit discovery connections, "
					  "no cdc connectivity",
	[NVMF_DISC_EFLAGS_DUPRETINFO |
	 NVMF_DISC_EFLAGS_NCC]		= "duplicate discovery information, "
					  "no cdc connectivity",
	[NVMF_DISC_EFLAGS_EPCSD |
	 NVMF_DISC_EFLAGS_DUPRETINFO |
	 NVMF_DISC_EFLAGS_NCC]		= "explicit discovery connections, "
					  "duplicate discovery information, "
					  "no cdc connectivity",
};

const char *nvmf_eflags_str(__u16 eflags)
{
	return arg_str(eflags_strings, ARRAY_SIZE(eflags_strings), eflags);
}

static const char * const sectypes[] = {
	[NVMF_TCP_SECTYPE_NONE]		= "none",
	[NVMF_TCP_SECTYPE_TLS]		= "tls",
	[NVMF_TCP_SECTYPE_TLS13]	= "tls13",
};

const char *nvmf_sectype_str(__u8 sectype)
{
	return arg_str(sectypes, ARRAY_SIZE(sectypes), sectype);
}

static const char * const prtypes[] = {
	[NVMF_RDMA_PRTYPE_NOT_SPECIFIED]	= "not specified",
	[NVMF_RDMA_PRTYPE_IB]			= "infiniband",
	[NVMF_RDMA_PRTYPE_ROCE]			= "roce",
	[NVMF_RDMA_PRTYPE_ROCEV2]		= "roce-v2",
	[NVMF_RDMA_PRTYPE_IWARP]		= "iwarp",
};

const char *nvmf_prtype_str(__u8 prtype)
{
	return arg_str(prtypes, ARRAY_SIZE(prtypes), prtype);
}

static const char * const qptypes[] = {
	[NVMF_RDMA_QPTYPE_CONNECTED]	= "connected",
	[NVMF_RDMA_QPTYPE_DATAGRAM]	= "datagram",
};

const char *nvmf_qptype_str(__u8 qptype)
{
	return arg_str(qptypes, ARRAY_SIZE(qptypes), qptype);
}

static const char * const cms[] = {
	[NVMF_RDMA_CMS_RDMA_CM]	= "rdma-cm",
};

const char *nvmf_cms_str(__u8 cm)
{
	return arg_str(cms, ARRAY_SIZE(cms), cm);
}

void nvmf_default_config(struct nvme_fabrics_config *cfg)
{
	memset(cfg, 0, sizeof(*cfg));
	cfg->tos = -1;
	cfg->ctrl_loss_tmo = NVMF_DEF_CTRL_LOSS_TMO;
}

#define MERGE_CFG_OPTION(c, n, o, d)			\
	if ((c)->o == d) (c)->o = (n)->o
#define MERGE_CFG_OPTION_STR(c, n, o, d)		\
	if ((c)->o == d && (n)->o) (c)->o = strdup((n)->o)
static struct nvme_fabrics_config *merge_config(nvme_ctrl_t c,
		const struct nvme_fabrics_config *cfg)
{
	struct nvme_fabrics_config *ctrl_cfg = nvme_ctrl_get_config(c);

	MERGE_CFG_OPTION_STR(ctrl_cfg, cfg, host_traddr, NULL);
	MERGE_CFG_OPTION_STR(ctrl_cfg, cfg, host_iface, NULL);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, nr_io_queues, 0);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, nr_write_queues, 0);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, nr_poll_queues, 0);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, queue_size, 0);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, keep_alive_tmo, 0);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, reconnect_delay, 0);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, ctrl_loss_tmo,
			  NVMF_DEF_CTRL_LOSS_TMO);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, fast_io_fail_tmo, 0);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, tos, -1);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, keyring, 0);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, tls_key, 0);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, duplicate_connect, false);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, disable_sqflow, false);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, hdr_digest, false);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, data_digest, false);
	MERGE_CFG_OPTION(ctrl_cfg, cfg, tls, false);

	return ctrl_cfg;
}

#define UPDATE_CFG_OPTION(c, n, o, d)			\
	if ((n)->o != d) (c)->o = (n)->o
void nvmf_update_config(nvme_ctrl_t c, const struct nvme_fabrics_config *cfg)
{
	struct nvme_fabrics_config *ctrl_cfg = nvme_ctrl_get_config(c);

	UPDATE_CFG_OPTION(ctrl_cfg, cfg, host_traddr, NULL);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, host_iface, NULL);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, nr_io_queues, 0);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, nr_write_queues, 0);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, nr_poll_queues, 0);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, queue_size, 0);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, keep_alive_tmo, 0);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, reconnect_delay, 0);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, ctrl_loss_tmo,
			  NVMF_DEF_CTRL_LOSS_TMO);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, fast_io_fail_tmo, 0);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, tos, -1);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, keyring, 0);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, tls_key, 0);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, duplicate_connect, false);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, disable_sqflow, false);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, hdr_digest, false);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, data_digest, false);
	UPDATE_CFG_OPTION(ctrl_cfg, cfg, tls, false);
}

static int add_bool_argument(char **argstr, char *tok, bool arg)
{
	char *nstr;

	if (!arg)
		return 0;
	if (asprintf(&nstr, "%s,%s", *argstr, tok) < 0) {
		errno = ENOMEM;
		return -1;
	}
	free(*argstr);
	*argstr = nstr;

	return 0;
}

static int add_int_argument(char **argstr, char *tok, int arg, bool allow_zero)
{
	char *nstr;

	if (arg < 0 || (!arg && !allow_zero))
		return 0;
	if (asprintf(&nstr, "%s,%s=%d", *argstr, tok, arg) < 0) {
		errno = ENOMEM;
		return -1;
	}
	free(*argstr);
	*argstr = nstr;

	return 0;
}

static int add_int_or_minus_one_argument(char **argstr, char *tok, int arg)
{
	char *nstr;

	if (arg < -1)
		return 0;
	if (asprintf(&nstr, "%s,%s=%d", *argstr, tok, arg) < 0) {
		errno = ENOMEM;
		return -1;
	}
	free(*argstr);
	*argstr = nstr;

	return 0;
}

static int add_argument(char **argstr, const char *tok, const char *arg)
{
	char *nstr;

	if (!arg || arg[0] == '\0' || !strcmp(arg, "none"))
		return 0;
	if (asprintf(&nstr, "%s,%s=%s", *argstr, tok, arg) < 0) {
		errno = ENOMEM;
		return -1;
	}
	free(*argstr);
	*argstr = nstr;

	return 0;
}

static int inet4_pton(const char *src, uint16_t port,
		      struct sockaddr_storage *addr)
{
	struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;

	if (strlen(src) > INET_ADDRSTRLEN)
		return -EINVAL;

	if (inet_pton(AF_INET, src, &addr4->sin_addr.s_addr) <= 0)
		return -EINVAL;

	addr4->sin_family = AF_INET;
	addr4->sin_port = htons(port);

	return 0;
}

static int inet6_pton(nvme_root_t r, const char *src, uint16_t port,
		      struct sockaddr_storage *addr)
{
	int ret = -EINVAL;
	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
	const char *scope = NULL;
	char *p;

	if (strlen(src) > INET6_ADDRSTRLEN)
		return -EINVAL;

	char  *tmp = strdup(src);
	if (!tmp) {
		nvme_msg(r, LOG_ERR, "cannot copy: %s\n", src);
		return -ENOMEM;
	}

	p = strchr(tmp, '%');
	if (p) {
		*p = '\0';
		scope = src + (p - tmp) + 1;
	}

	if (inet_pton(AF_INET6, tmp, &addr6->sin6_addr) != 1)
		goto free_tmp;

	if (IN6_IS_ADDR_LINKLOCAL(&addr6->sin6_addr) && scope) {
		addr6->sin6_scope_id = if_nametoindex(scope);
		if (addr6->sin6_scope_id == 0) {
			nvme_msg(r, LOG_ERR,
				 "can't find iface index for: %s (%m)\n", scope);
			goto free_tmp;
		}
	}

	addr6->sin6_family = AF_INET6;
	addr6->sin6_port = htons(port);
	ret = 0;

free_tmp:
	free(tmp);
	return ret;
}

/**
 * inet_pton_with_scope - convert an IPv4/IPv6 to socket address
 * @r: nvme_root_t object
 * @af: address family, AF_INET, AF_INET6 or AF_UNSPEC for either
 * @src: the start of the address string
 * @trsvcid: transport service identifier
 * @addr: output socket address
 *
 * Return 0 on success, errno otherwise.
 */
static int inet_pton_with_scope(nvme_root_t r, int af,
				const char *src, const char * trsvcid,
				struct sockaddr_storage *addr)
{
	int      ret  = -EINVAL;
	uint16_t port = 0;

	if (trsvcid) {
		unsigned long long tmp = strtoull(trsvcid, NULL, 0);
		port = (uint16_t)tmp;
		if (tmp != port) {
			nvme_msg(r, LOG_ERR, "trsvcid out of range: %s\n",
				 trsvcid);
			return -ERANGE;
		}
	} else {
		port = 0;
	}

	switch (af) {
	case AF_INET:
		ret = inet4_pton(src, port, addr);
		break;
	case AF_INET6:
		ret = inet6_pton(r, src, port, addr);
		break;
	case AF_UNSPEC:
		ret = inet4_pton(src, port, addr);
		if (ret)
			ret = inet6_pton(r, src, port, addr);
		break;
	default:
		nvme_msg(r, LOG_ERR, "unexpected address family %d\n", af);
	}

	return ret;
}

static bool traddr_is_hostname(nvme_root_t r, nvme_ctrl_t c)
{
	struct sockaddr_storage addr;

	if (!c->traddr)
		return false;
	if (strcmp(c->transport, "tcp") && strcmp(c->transport, "rdma"))
		return false;
	if (inet_pton_with_scope(r, AF_UNSPEC, c->traddr, c->trsvcid, &addr) == 0)
		return false;
	return true;
}

static int build_options(nvme_host_t h, nvme_ctrl_t c, char **argstr)
{
	struct nvme_fabrics_config *cfg = nvme_ctrl_get_config(c);
	const char *transport = nvme_ctrl_get_transport(c);
	const char *hostnqn, *hostid, *hostkey, *ctrlkey;
	bool discover = false, discovery_nqn = false;

	if (!transport) {
		nvme_msg(h->r, LOG_ERR, "need a transport (-t) argument\n");
		errno = ENVME_CONNECT_TARG;
		return -1;
	}

	if (strncmp(transport, "loop", 4)) {
		if (!nvme_ctrl_get_traddr(c)) {
			nvme_msg(h->r, LOG_ERR, "need a address (-a) argument\n");
			errno = ENVME_CONNECT_AARG;
			return -1;
		}
	}

	/* always specify nqn as first arg - this will init the string */
	if (asprintf(argstr, "nqn=%s",
		     nvme_ctrl_get_subsysnqn(c)) < 0) {
		errno = ENOMEM;
		return -1;
	}
	if (!strcmp(nvme_ctrl_get_subsysnqn(c), NVME_DISC_SUBSYS_NAME)) {
		nvme_ctrl_set_discovery_ctrl(c, true);
		nvme_ctrl_set_unique_discovery_ctrl(c, false);
		discovery_nqn = true;
	}
	if (nvme_ctrl_is_discovery_ctrl(c))
		discover = true;
	hostnqn = nvme_host_get_hostnqn(h);
	hostid = nvme_host_get_hostid(h);
	hostkey = nvme_host_get_dhchap_key(h);
	if (!hostkey)
		hostkey = nvme_ctrl_get_dhchap_host_key(c);
	ctrlkey = nvme_ctrl_get_dhchap_key(c);
	if (add_argument(argstr, "transport", transport) ||
	    add_argument(argstr, "traddr",
			 nvme_ctrl_get_traddr(c)) ||
	    add_argument(argstr, "host_traddr",
			 cfg->host_traddr) ||
	    add_argument(argstr, "host_iface",
			 cfg->host_iface) ||
	    add_argument(argstr, "trsvcid",
			 nvme_ctrl_get_trsvcid(c)) ||
	    (hostnqn && add_argument(argstr, "hostnqn", hostnqn)) ||
	    (hostid && add_argument(argstr, "hostid", hostid)) ||
	    (discover && !discovery_nqn &&
	     add_bool_argument(argstr, "discovery", true)) ||
	    (!discover && hostkey &&
	     add_argument(argstr, "dhchap_secret", hostkey)) ||
	    (!discover && ctrlkey &&
	     add_argument(argstr, "dhchap_ctrl_secret", ctrlkey)) ||
	    (!discover &&
	     add_int_argument(argstr, "nr_io_queues",
			      cfg->nr_io_queues, false)) ||
	    (!discover &&
	     add_int_argument(argstr, "nr_write_queues",
			      cfg->nr_write_queues, false)) ||
	    (!discover &&
	     add_int_argument(argstr, "nr_poll_queues",
			      cfg->nr_poll_queues, false)) ||
	    (!discover &&
	     add_int_argument(argstr, "queue_size",
			      cfg->queue_size, false)) ||
	    add_int_argument(argstr, "keep_alive_tmo",
			     cfg->keep_alive_tmo, false) ||
	    add_int_argument(argstr, "reconnect_delay",
			     cfg->reconnect_delay, false) ||
	    (strcmp(transport, "loop") &&
	     add_int_or_minus_one_argument(argstr, "ctrl_loss_tmo",
			      cfg->ctrl_loss_tmo)) ||
	    (strcmp(transport, "loop") &&
	     add_int_argument(argstr, "fast_io_fail_tmo",
			      cfg->fast_io_fail_tmo, false)) ||
	    (strcmp(transport, "loop") &&
	     add_int_argument(argstr, "tos", cfg->tos, true)) ||
	    add_int_argument(argstr, "keyring", cfg->keyring, false) ||
	    (!strcmp(transport, "tcp") &&
	     add_int_argument(argstr, "tls_key", cfg->tls_key, false)) ||
	    add_bool_argument(argstr, "duplicate_connect",
			      cfg->duplicate_connect) ||
	    add_bool_argument(argstr, "disable_sqflow",
			      cfg->disable_sqflow) ||
	    (!strcmp(transport, "tcp") &&
	     add_bool_argument(argstr, "hdr_digest", cfg->hdr_digest)) ||
	    (!strcmp(transport, "tcp") &&
	     add_bool_argument(argstr, "data_digest", cfg->data_digest)) ||
	    (!strcmp(transport, "tcp") &&
	     add_bool_argument(argstr, "tls", cfg->tls))) {
		free(*argstr);
		return -1;
	}

	return 0;
}

static int __nvmf_add_ctrl(nvme_root_t r, const char *argstr)
{
	int ret, fd, len = strlen(argstr);
	char buf[0x1000], *options, *p;

	fd = open(nvmf_dev, O_RDWR);
	if (fd < 0) {
		nvme_msg(r, LOG_ERR, "Failed to open %s: %s\n",
			 nvmf_dev, strerror(errno));
		return -ENVME_CONNECT_OPEN;
	}

	nvme_msg(r, LOG_DEBUG, "connect ctrl, '%.*s'\n",
		 (int)strcspn(argstr,"\n"), argstr);
	ret = write(fd, argstr, len);
	if (ret != len) {
		nvme_msg(r, LOG_NOTICE, "Failed to write to %s: %s\n",
			 nvmf_dev, strerror(errno));
		switch (errno) {
		case EALREADY:
			ret = -ENVME_CONNECT_ALREADY;
			break;
		case EINVAL:
			ret = -ENVME_CONNECT_INVAL;
			break;
		case EADDRINUSE:
			ret = -ENVME_CONNECT_ADDRINUSE;
			break;
		case ENODEV:
			ret = -ENVME_CONNECT_NODEV;
			break;
		case EOPNOTSUPP:
			ret = -ENVME_CONNECT_OPNOTSUPP;
			break;
		case ECONNREFUSED :
			ret = -ENVME_CONNECT_CONNREFUSED;
			break;
		default:
			ret = -ENVME_CONNECT_WRITE;
			break;
		}
		goto out_close;
	}

	memset(buf, 0x0, sizeof(buf));
	len = read(fd, buf, sizeof(buf) - 1);
	if (len < 0) {
		nvme_msg(r, LOG_ERR, "Failed to read from %s: %s\n",
			 nvmf_dev, strerror(errno));
		ret = -ENVME_CONNECT_READ;
		goto out_close;
	}
	nvme_msg(r, LOG_DEBUG, "connect ctrl, response '%.*s'\n",
		 (int)strcspn(buf, "\n"), buf);
	buf[len] = '\0';
	options = buf;
	while ((p = strsep(&options, ",\n")) != NULL) {
		if (!*p)
			continue;
		if (sscanf(p, "instance=%d", &ret) == 1)
			goto out_close;
	}

	nvme_msg(r, LOG_ERR, "Failed to parse ctrl info for \"%s\"\n", argstr);
	ret = -ENVME_CONNECT_PARSE;
out_close:
	close(fd);
	return ret;
}

int nvmf_add_ctrl(nvme_host_t h, nvme_ctrl_t c,
		  const struct nvme_fabrics_config *cfg)
{
	nvme_subsystem_t s;
	char *argstr;
	int ret;

	/* highest prio have configs from command line */
	cfg = merge_config(c, cfg);

	/* apply configuration from config file (JSON) */
	s = nvme_lookup_subsystem(h, NULL, nvme_ctrl_get_subsysnqn(c));
	if (s) {
		nvme_ctrl_t fc;

		fc = __nvme_lookup_ctrl(s, nvme_ctrl_get_transport(c),
					nvme_ctrl_get_traddr(c),
					nvme_ctrl_get_host_traddr(c),
					nvme_ctrl_get_host_iface(c),
					nvme_ctrl_get_trsvcid(c),
					NULL);
		if (fc) {
			const char *key;

			cfg = merge_config(c, nvme_ctrl_get_config(fc));
			/*
			 * An authentication key might already been set
			 * in @cfg, so ensure to update @c with the correct
			 * controller key.
			 */
			key = nvme_ctrl_get_dhchap_host_key(fc);
			if (key)
				nvme_ctrl_set_dhchap_host_key(c, key);
			key = nvme_ctrl_get_dhchap_key(fc);
			if (key)
				nvme_ctrl_set_dhchap_key(c, key);
		}

	}

	nvme_ctrl_set_discovered(c, true);
	if (traddr_is_hostname(h->r, c)) {
		char *traddr = c->traddr;

		c->traddr = hostname2traddr(h->r, traddr);
		if (!c->traddr) {
			c->traddr = traddr;
			errno = ENVME_CONNECT_TRADDR;
			return -1;
		}
		free(traddr);
	}

	ret = build_options(h, c, &argstr);
	if (ret)
		return ret;

	ret = __nvmf_add_ctrl(h->r, argstr);
	free(argstr);
	if (ret < 0) {
		errno = -ret;
		return -1;
	}

	nvme_msg(h->r, LOG_INFO, "nvme%d: %s connected\n", ret,
		 nvme_ctrl_get_subsysnqn(c));
	return nvme_init_ctrl(h, c, ret);
}

nvme_ctrl_t nvmf_connect_disc_entry(nvme_host_t h,
				    struct nvmf_disc_log_entry *e,
				    const struct nvme_fabrics_config *cfg,
				    bool *discover)
{
	const char *transport;
	char *traddr = NULL, *trsvcid = NULL;
	nvme_ctrl_t c;
	int ret;

	switch (e->trtype) {
	case NVMF_TRTYPE_RDMA:
	case NVMF_TRTYPE_TCP:
		switch (e->adrfam) {
		case NVMF_ADDR_FAMILY_IP4:
		case NVMF_ADDR_FAMILY_IP6:
			traddr = e->traddr;
			trsvcid = e->trsvcid;
			break;
		default:
			nvme_msg(h->r, LOG_ERR,
				 "skipping unsupported adrfam %d\n",
				 e->adrfam);
			errno = EINVAL;
			return NULL;
		}
		break;
        case NVMF_TRTYPE_FC:
		switch (e->adrfam) {
		case NVMF_ADDR_FAMILY_FC:
			traddr = e->traddr;
			break;
		default:
			nvme_msg(h->r, LOG_ERR,
				 "skipping unsupported adrfam %d\n",
				 e->adrfam);
			errno = EINVAL;
			return NULL;
		}
		break;
	case NVMF_TRTYPE_LOOP:
		traddr = strlen(e->traddr) ? e->traddr : NULL;
		break;
	default:
		nvme_msg(h->r, LOG_ERR, "skipping unsupported transport %d\n",
			 e->trtype);
		errno = EINVAL;
		return NULL;
	}

	transport = nvmf_trtype_str(e->trtype);

	nvme_msg(h->r, LOG_DEBUG, "lookup ctrl "
		 "(transport: %s, traddr: %s, trsvcid %s)\n",
		 transport, traddr, trsvcid);
	c = nvme_create_ctrl(h->r, e->subnqn, transport, traddr,
			     cfg->host_traddr, cfg->host_iface, trsvcid);
	if (!c) {
		nvme_msg(h->r, LOG_DEBUG, "skipping discovery entry, "
			 "failed to allocate %s controller with traddr %s\n",
			 transport, traddr);
		errno = ENOMEM;
		return NULL;
	}

	switch (e->subtype) {
	case NVME_NQN_CURR:
		nvme_ctrl_set_discovered(c, true);
		nvme_ctrl_set_unique_discovery_ctrl(c,
				strcmp(e->subnqn, NVME_DISC_SUBSYS_NAME));
		break;
	case NVME_NQN_DISC:
		if (discover)
			*discover = true;
		nvme_ctrl_set_discovery_ctrl(c, true);
		nvme_ctrl_set_unique_discovery_ctrl(c,
				strcmp(e->subnqn, NVME_DISC_SUBSYS_NAME));
		break;
	default:
		nvme_msg(h->r, LOG_ERR, "unsupported subtype %d\n",
			 e->subtype);
		fallthrough;
	case NVME_NQN_NVME:
		nvme_ctrl_set_discovery_ctrl(c, false);
		nvme_ctrl_set_unique_discovery_ctrl(c, false);
		break;
	}

	if (nvme_ctrl_is_discovered(c)) {
		nvme_free_ctrl(c);
		errno = EAGAIN;
		return NULL;
	}

	if (e->treq & NVMF_TREQ_DISABLE_SQFLOW)
		c->cfg.disable_sqflow = true;

	if (e->trtype == NVMF_TRTYPE_TCP &&
	    (e->treq & NVMF_TREQ_REQUIRED ||
	     e->treq & NVMF_TREQ_NOT_REQUIRED))
		c->cfg.tls = true;

	ret = nvmf_add_ctrl(h, c, cfg);
	if (!ret)
		return c;

	if (errno == EINVAL && c->cfg.disable_sqflow) {
		errno = 0;
		/* disable_sqflow is unrecognized option on older kernels */
		nvme_msg(h->r, LOG_INFO, "failed to connect controller, "
			 "retry with disabling SQ flow control\n");
		c->cfg.disable_sqflow = false;
		ret = nvmf_add_ctrl(h, c, cfg);
		if (!ret)
			return c;
	}
	nvme_free_ctrl(c);
	return NULL;
}

static struct nvmf_discovery_log *nvme_discovery_log(nvme_ctrl_t c,
						     struct nvme_get_log_args *args,
						     int max_retries)
{
	nvme_root_t r = c->s && c->s->h ? c->s->h->r : NULL;
	struct nvmf_discovery_log *log = NULL;
	int ret, retries = 0;
	const char *name = nvme_ctrl_get_name(c);
	uint64_t genctr, numrec;
	unsigned int size;
	int fd = nvme_ctrl_get_fd(c);

	args->fd = fd;

	do {
		size = sizeof(struct nvmf_discovery_log);

		free(log);
		log = calloc(1, size);
		if (!log) {
			nvme_msg(r, LOG_ERR,
				 "could not allocate memory for discovery log header\n");
			errno = ENOMEM;
			return NULL;
		}

		nvme_msg(r, LOG_DEBUG, "%s: get header (try %d/%d)\n",
			name, retries, max_retries);
		args->rae = true;
		args->len = size;
		args->log = log;
		ret = nvme_get_log_page(fd, 4096, args);
		if (ret) {
			nvme_msg(r, LOG_INFO,
				 "%s: discover try %d/%d failed, error %d\n",
				 name, retries, max_retries, errno);
			goto out_free_log;
		}

		numrec = le64_to_cpu(log->numrec);
		genctr = le64_to_cpu(log->genctr);

		if (numrec == 0)
			break;

		size = sizeof(struct nvmf_discovery_log) +
			sizeof(struct nvmf_disc_log_entry) * numrec;

		free(log);
		log = calloc(1, size);
		if (!log) {
			nvme_msg(r, LOG_ERR,
				 "could not alloc memory for discovery log page\n");
			errno = ENOMEM;
			return NULL;
		}

		nvme_msg(r, LOG_DEBUG,
			 "%s: get header and %" PRIu64
			 " records (length %d genctr %" PRIu64 ")\n",
			 name, numrec, size, genctr);

		args->rae = false;
		args->len = size;
		args->log = log;
		ret = nvme_get_log_page(fd, 4096, args);

		if (ret) {
			nvme_msg(r, LOG_INFO,
				 "%s: discover try %d/%d failed, error %d\n",
				 name, retries, max_retries, errno);
			goto out_free_log;
		}
	} while (genctr != le64_to_cpu(log->genctr) &&
		 ++retries < max_retries);

	if (genctr != le64_to_cpu(log->genctr)) {
		nvme_msg(r, LOG_INFO, "%s: discover genctr mismatch\n", name);
		errno = EAGAIN;
	} else if (numrec != le64_to_cpu(log->numrec)) {
		nvme_msg(r, LOG_INFO,
			 "%s: could only fetch %" PRIu64 " of %" PRIu64 " records\n",
			 name, numrec, le64_to_cpu(log->numrec));
		errno = EBADSLT;
	} else {
		return log;
	}

out_free_log:
	free(log);
	return NULL;
}

static void sanitize_discovery_log_entry(struct nvmf_disc_log_entry  *e)
{
	switch (e->trtype) {
	case NVMF_TRTYPE_RDMA:
	case NVMF_TRTYPE_TCP:
		switch (e->adrfam) {
		case NVMF_ADDR_FAMILY_IP4:
		case NVMF_ADDR_FAMILY_IP6:
			strchomp(e->traddr, NVMF_TRADDR_SIZE);
			strchomp(e->trsvcid, NVMF_TRSVCID_SIZE);
			break;
		}
		break;
        case NVMF_TRTYPE_FC:
		switch (e->adrfam) {
		case NVMF_ADDR_FAMILY_FC:
			strchomp(e->traddr, NVMF_TRADDR_SIZE);
			break;
		}
		break;
	case NVMF_TRTYPE_LOOP:
		strchomp(e->traddr, NVMF_TRADDR_SIZE);
		break;
	}
}

int nvmf_get_discovery_log(nvme_ctrl_t c, struct nvmf_discovery_log **logp,
			   int max_retries)
{
	struct nvmf_discovery_log *log;

	struct nvme_get_log_args args = {
		.args_size = sizeof(args),
		.fd = nvme_ctrl_get_fd(c),
		.nsid = NVME_NSID_NONE,
		.lsp = NVMF_LOG_DISC_LSP_NONE,
		.lsi = NVME_LOG_LSI_NONE,
		.uuidx = NVME_UUID_NONE,
		.timeout = NVME_DEFAULT_IOCTL_TIMEOUT,
		.result = NULL,
		.lid = NVME_LOG_LID_DISCOVER,
		.log = NULL,
		.len = 0,
		.csi = NVME_CSI_NVM,
		.rae = false,
		.ot = false,
	};

	log = nvme_discovery_log(c, &args, max_retries);
	if (!log)
		return -1;

	for (int i = 0; i < le64_to_cpu(log->numrec); i++)
		sanitize_discovery_log_entry(&log->entries[i]);

	*logp = log;
	return 0;
}

struct nvmf_discovery_log *nvmf_get_discovery_wargs(struct nvme_get_discovery_args *args)
{
	struct nvmf_discovery_log *log;

	struct nvme_get_log_args _args = {
		.args_size = sizeof(_args),
		.fd = nvme_ctrl_get_fd(args->c),
		.nsid = NVME_NSID_NONE,
		.lsp = args->lsp,
		.lsi = NVME_LOG_LSI_NONE,
		.uuidx = NVME_UUID_NONE,
		.timeout = args->timeout,
		.result = args->result,
		.lid = NVME_LOG_LID_DISCOVER,
		.log = NULL,
		.len = 0,
		.csi = NVME_CSI_NVM,
		.rae = false,
		.ot = false,
	};

	log = nvme_discovery_log(args->c, &_args, args->max_retries);
	if (!log)
		return NULL;

	for (int i = 0; i < le64_to_cpu(log->numrec); i++)
		sanitize_discovery_log_entry(&log->entries[i]);

	return log;
}

#define PATH_UUID_IBM	"/proc/device-tree/ibm,partition-uuid"

static int uuid_from_device_tree(char *system_uuid)
{
	ssize_t len;
	int f;

	f = open(PATH_UUID_IBM, O_RDONLY);
	if (f < 0)
		return -ENXIO;

	memset(system_uuid, 0, NVME_UUID_LEN_STRING);
	len = read(f, system_uuid, NVME_UUID_LEN_STRING - 1);
	close(f);
	if (len < 0)
		return -ENXIO;

	return strlen(system_uuid) ? 0 : -ENXIO;
}

#define PATH_DMI_ENTRIES       "/sys/firmware/dmi/entries"

/*
 * See System Management BIOS (SMBIOS) Reference Specification
 * https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.2.0.pdf
 */
#define DMI_SYSTEM_INFORMATION	1

static bool is_dmi_uuid_valid(const char *buf, size_t len)
{
	int i;

	/* UUID bytes are from byte 8 to 23 */
	if (len < 24)
		return false;

	/* Test it's a invalid UUID with all zeros */
	for (i = 8; i < 24; i++) {
		if (buf[i])
			break;
	}
	if (i == 24)
		return false;

	return true;
}

static int uuid_from_dmi_entries(char *system_uuid)
{
	int f;
	DIR *d;
	struct dirent *de;
	char buf[512] = {0};

	system_uuid[0] = '\0';
	d = opendir(PATH_DMI_ENTRIES);
	if (!d)
		return -ENXIO;
	while ((de = readdir(d))) {
		char filename[PATH_MAX];
		int len, type;

		if (de->d_name[0] == '.')
			continue;
		sprintf(filename, "%s/%s/type", PATH_DMI_ENTRIES, de->d_name);
		f = open(filename, O_RDONLY);
		if (f < 0)
			continue;
		len = read(f, buf, 512);
		close(f);
		if (len <= 0)
			continue;
		if (sscanf(buf, "%d", &type) != 1)
			continue;
		if (type != DMI_SYSTEM_INFORMATION)
			continue;
		sprintf(filename, "%s/%s/raw", PATH_DMI_ENTRIES, de->d_name);
		f = open(filename, O_RDONLY);
		if (f < 0)
			continue;
		len = read(f, buf, 512);
		close(f);

		if (!is_dmi_uuid_valid(buf, len))
			continue;

		/* Sigh. https://en.wikipedia.org/wiki/Overengineering */
		/* DMTF SMBIOS 3.0 Section 7.2.1 System UUID */
		sprintf(system_uuid,
			"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-"
			"%02x%02x%02x%02x%02x%02x",
			(uint8_t)buf[8 + 3], (uint8_t)buf[8 + 2],
			(uint8_t)buf[8 + 1], (uint8_t)buf[8 + 0],
			(uint8_t)buf[8 + 5], (uint8_t)buf[8 + 4],
			(uint8_t)buf[8 + 7], (uint8_t)buf[8 + 6],
			(uint8_t)buf[8 + 8], (uint8_t)buf[8 + 9],
			(uint8_t)buf[8 + 10], (uint8_t)buf[8 + 11],
			(uint8_t)buf[8 + 12], (uint8_t)buf[8 + 13],
			(uint8_t)buf[8 + 14], (uint8_t)buf[8 + 15]);
		break;
	}
	closedir(d);
	return strlen(system_uuid) ? 0 : -ENXIO;
}

#define PATH_DMI_PROD_UUID  "/sys/class/dmi/id/product_uuid"

/**
 * uuid_from_product_uuid() - Get system UUID from product_uuid
 * @system_uuid: Where to save the system UUID.
 *
 * Return: 0 on success, -ENXIO otherwise.
 */
static int uuid_from_product_uuid(char *system_uuid)
{
	FILE *stream;
	ssize_t nread;
	int ret;
	char *line = NULL;
	size_t len = 0;

	stream = fopen(PATH_DMI_PROD_UUID, "re");
	if (!stream)
		return -ENXIO;
	system_uuid[0] = '\0';

	nread = getline(&line, &len, stream);
	if (nread != NVME_UUID_LEN_STRING) {
		ret = -ENXIO;
		goto out;
	}

	/* The kernel is handling the byte swapping according DMTF
	 * SMBIOS 3.0 Section 7.2.1 System UUID */

	memcpy(system_uuid, line, NVME_UUID_LEN_STRING - 1);
	system_uuid[NVME_UUID_LEN_STRING - 1] = '\0';

	ret = 0;

out:
	free(line);
	fclose(stream);

	return ret;
}

/**
 * uuid_from_dmi() - read system UUID
 * @system_uuid: buffer for the UUID
 *
 * The system UUID can be read from two different locations:
 *
 *     1) /sys/class/dmi/id/product_uuid
 *     2) /sys/firmware/dmi/entries
 *
 * Note that the second location is not present on Debian-based systems.
 *
 * Return: 0 on success, negative errno otherwise.
 */
static int uuid_from_dmi(char *system_uuid)
{
	int ret = uuid_from_product_uuid(system_uuid);
	if (ret != 0)
		ret = uuid_from_dmi_entries(system_uuid);
	return ret;
}

char *nvmf_hostnqn_generate()
{
	char *hostnqn;
	int ret;
	char uuid_str[NVME_UUID_LEN_STRING];
	unsigned char uuid[NVME_UUID_LEN];

	ret = uuid_from_dmi(uuid_str);
	if (ret < 0) {
		ret = uuid_from_device_tree(uuid_str);
	}
	if (ret < 0) {
		if (nvme_uuid_random(uuid) < 0)
			memset(uuid, 0, NVME_UUID_LEN);
		nvme_uuid_to_string(uuid, uuid_str);
	}

	if (asprintf(&hostnqn, "nqn.2014-08.org.nvmexpress:uuid:%s", uuid_str) < 0)
		return NULL;

	return hostnqn;
}

static char *nvmf_read_file(const char *f, int len)
{
	char buf[len];
	int ret, fd;

	fd = open(f, O_RDONLY);
	if (fd < 0)
		return NULL;

	memset(buf, 0, len);
	ret = read(fd, buf, len - 1);
	close (fd);

	if (ret < 0 || !strlen(buf))
		return NULL;
	return strndup(buf, strcspn(buf, "\n"));
}

char *nvmf_hostnqn_from_file()
{
	return nvmf_read_file(NVMF_HOSTNQN_FILE, NVMF_NQN_SIZE);
}

char *nvmf_hostid_from_file()
{
	return nvmf_read_file(NVMF_HOSTID_FILE, NVMF_HOSTID_SIZE);
}

/**
 * nvmf_get_tel() - Calculate the amount of memory needed for a DIE.
 * @hostsymname:	Symbolic name (may be NULL)
 *
 * Each Discovery Information Entry (DIE) must contain at a minimum an
 * Extended Attribute for the HostID. The Entry may optionally contain an
 * Extended Attribute for the Symbolic Name.
 *
 * Return: Total Entry Length
 */
static __u32 nvmf_get_tel(const char *hostsymname)
{
	__u32 tel = sizeof(struct nvmf_ext_die);
	__u16 len;

	/* Host ID is mandatory */
	tel += nvmf_exat_size(NVME_UUID_LEN);

	/* Symbolic name is optional */
	len = hostsymname ? strlen(hostsymname) : 0;
	if (len)
		tel += nvmf_exat_size(len);

	return tel;
}

/**
 * nvmf_fill_die() - Fill a Discovery Information Entry.
 * @die:	Pointer to Discovery Information Entry to be filled
 * @h:		Pointer to the host data structure
 * @tel:	Length of the DIE
 * @trtype:	Transport type
 * @adrfam:	Address family
 * @reg_addr:	Address to register. Setting this to an empty string tells
 *		the DC to infer address from the source address of the socket.
 * @tsas:	Transport Specific Address Subtype for the address being
 *		registered.
 */
static void nvmf_fill_die(struct nvmf_ext_die *die, struct nvme_host *h,
			  __u32 tel, __u8 trtype, __u8 adrfam,
			  const char *reg_addr, union nvmf_tsas *tsas)
{
	__u16 numexat = 0;
	size_t symname_len;
	struct nvmf_ext_attr *exat;

	die->tel = cpu_to_le32(tel);
	die->trtype = trtype;
	die->adrfam = adrfam;

	memcpy(die->nqn, h->hostnqn, MIN(sizeof(die->nqn), strlen(h->hostnqn)));
	memcpy(die->traddr, reg_addr, MIN(sizeof(die->traddr), strlen(reg_addr)));

	if (tsas)
		memcpy(&die->tsas, tsas, sizeof(die->tsas));

	/* Extended Attribute for the HostID (mandatory) */
	numexat++;
	exat = die->exat;
	exat->exattype = cpu_to_le16(NVMF_EXATTYPE_HOSTID);
	exat->exatlen  = cpu_to_le16(nvmf_exat_len(NVME_UUID_LEN));
	nvme_uuid_from_string(h->hostid, exat->exatval);

	/* Extended Attribute for the Symbolic Name (optional) */
	symname_len = h->hostsymname ? strlen(h->hostsymname) : 0;
	if (symname_len) {
		__u16 exatlen = nvmf_exat_len(symname_len);

		numexat++;
		exat = nvmf_exat_ptr_next(exat);
		exat->exattype = cpu_to_le16(NVMF_EXATTYPE_SYMNAME);
		exat->exatlen  = cpu_to_le16(exatlen);
		memcpy(exat->exatval, h->hostsymname, symname_len);
		/* Per Base specs, ASCII strings must be padded with spaces */
		memset(&exat->exatval[symname_len], ' ', exatlen - symname_len);
	}

	die->numexat = cpu_to_le16(numexat);
}

/**
 * nvmf_dim() - Explicit reg, dereg, reg-update issuing DIM
 * @c:		Host NVMe controller instance maintaining the admin queue used to
 *		submit the DIM command to the DC.
 * @tas:	Task field of the Command Dword 10 (cdw10). Indicates whether to
 *		perform a Registration, Deregistration, or Registration-update.
 * @trtype:	Transport type (&enum nvmf_trtype - must be NVMF_TRTYPE_TCP)
 * @adrfam:	Address family (&enum nvmf_addr_family)
 * @reg_addr:	Address to register. Setting this to an empty string tells
 *		the DC to infer address from the source address of the socket.
 * @tsas:	Transport Specific Address Subtype for the address being
 *		registered.
 * @result:	Location where to save the command-specific result returned by
 *		the discovery controller.
 *
 * Perform explicit registration, deregistration, or
 * registration-update (specified by @tas) by sending a Discovery
 * Information Management (DIM) command to the Discovery Controller
 * (DC).
 *
 * Return: 0 on success; on failure -1 is returned and errno is set
 */
static int nvmf_dim(nvme_ctrl_t c, enum nvmf_dim_tas tas, __u8 trtype,
		    __u8 adrfam, const char *reg_addr, union nvmf_tsas *tsas,
		    __u32 *result)
{
	nvme_root_t r = c->s && c->s->h ? c->s->h->r : NULL;
	struct nvmf_dim_data *dim;
	struct nvmf_ext_die  *die;
	__u32 tdl;
	__u32 tel;
	int ret;

	struct nvme_dim_args args = {
		.args_size = sizeof(args),
		.fd = nvme_ctrl_get_fd(c),
		.result = result,
		.timeout = NVME_DEFAULT_IOCTL_TIMEOUT,
		.tas = tas
	};

	if (!c->s) {
		nvme_msg(r, LOG_ERR,
			 "%s: failed to perform DIM. subsystem undefined.\n",
			 c->name);
		errno = EINVAL;
		return -1;
	}

	if (!c->s->h) {
		nvme_msg(r, LOG_ERR,
			 "%s: failed to perform DIM. host undefined.\n",
			 c->name);
		errno = EINVAL;
		return -1;
	}

	if (!c->s->h->hostid) {
		nvme_msg(r, LOG_ERR,
			 "%s: failed to perform DIM. hostid undefined.\n",
			 c->name);
		errno = EINVAL;
		return -1;
	}

	if (!c->s->h->hostnqn) {
		nvme_msg(r, LOG_ERR,
			 "%s: failed to perform DIM. hostnqn undefined.\n",
			 c->name);
		errno = EINVAL;
		return -1;
	}

	if (strcmp(c->transport, "tcp")) {
		nvme_msg(r, LOG_ERR,
			 "%s: DIM only supported for TCP connections.\n",
			 c->name);
		errno = EINVAL;
		return -1;
	}

	/* Register one Discovery Information Entry (DIE) of size TEL */
	tel = nvmf_get_tel(c->s->h->hostsymname);
	tdl = sizeof(struct nvmf_dim_data) + tel;

	dim = (struct nvmf_dim_data *)calloc(1, tdl);
	if (!dim) {
		errno = ENOMEM;
		return -1;
	}

	dim->tdl    = cpu_to_le32(tdl);
	dim->nument = cpu_to_le64(1);    /* only one DIE to register */
	dim->entfmt = cpu_to_le16(NVMF_DIM_ENTFMT_EXTENDED);
	dim->etype  = cpu_to_le16(NVMF_DIM_ETYPE_HOST);
	dim->ektype = cpu_to_le16(0x5F); /* must be 0x5F per specs */

	memcpy(dim->eid, c->s->h->hostnqn,
	       MIN(sizeof(dim->eid), strlen(c->s->h->hostnqn)));

	ret = get_entity_name(dim->ename, sizeof(dim->ename));
	if (ret <= 0)
		nvme_msg(r, LOG_INFO, "%s: Failed to retrieve ENAME. %s.\n",
			 c->name, strerror(errno));

	ret = get_entity_version(dim->ever, sizeof(dim->ever));
	if (ret <= 0)
		nvme_msg(r, LOG_INFO, "%s: Failed to retrieve EVER.\n", c->name);

	die = &dim->die->extended;
	nvmf_fill_die(die, c->s->h, tel, trtype, adrfam, reg_addr, tsas);

	args.data_len = tdl;
	args.data = dim;
	ret = nvme_dim_send(&args);

	free(dim);

	return ret;
}

/**
 * nvme_get_adrfam() - Get address family for the address we're registering
 * with the DC.
 *
 * We retrieve this info from the socket itself. If we can't get the source
 * address from the socket, then we'll infer the address family from the
 * address of the DC since the DC address has the same address family.
 *
 * @ctrl: Host NVMe controller instance maintaining the admin queue used to
 *   submit the DIM command to the DC.
 *
 * Return: The address family of the source address associated with the
 *   socket connected to the DC.
 */
static __u8 nvme_get_adrfam(nvme_ctrl_t c)
{
	struct sockaddr_storage addr;
	__u8 adrfam = NVMF_ADDR_FAMILY_IP4;
	nvme_root_t r = c->s && c->s->h ? c->s->h->r : NULL;

	if (!inet_pton_with_scope(r, AF_UNSPEC, c->traddr, c->trsvcid, &addr)) {
		if (addr.ss_family == AF_INET6)
			adrfam = NVMF_ADDR_FAMILY_IP6;
	}

	return adrfam;
}

/* These string definitions must match with the kernel */
static const char *cntrltype_str[] = {
	[NVME_CTRL_CNTRLTYPE_IO] = "io",
	[NVME_CTRL_CNTRLTYPE_DISCOVERY] = "discovery",
	[NVME_CTRL_CNTRLTYPE_ADMIN] = "admin",
};

static const char *dctype_str[] = {
	[NVME_CTRL_DCTYPE_NOT_REPORTED] = "none",
	[NVME_CTRL_DCTYPE_DDC] = "ddc",
	[NVME_CTRL_DCTYPE_CDC] = "cdc",
};

/**
 * nvme_fetch_cntrltype_dctype_from_id - Get cntrltype and dctype from identify command
 * @c:	Controller instance
 *
 * On legacy kernels the cntrltype and dctype are not exposed through the
 * sysfs. We must get them directly from the controller by performing an
 * identify command.
 */
static int nvme_fetch_cntrltype_dctype_from_id(nvme_ctrl_t c)
{
	struct nvme_id_ctrl id = { 0 };
	int ret;

	ret = nvme_ctrl_identify(c, &id);
	if (ret)
		return ret;

	if (!c->cntrltype) {
		if (id.cntrltype > NVME_CTRL_CNTRLTYPE_ADMIN || !cntrltype_str[id.cntrltype])
			c->cntrltype = strdup("reserved");
		else
			c->cntrltype = strdup(cntrltype_str[id.cntrltype]);
	}

	if (!c->dctype)	{
		if (id.dctype > NVME_CTRL_DCTYPE_CDC || !dctype_str[id.dctype])
			c->dctype = strdup("reserved");
		else
			c->dctype = strdup(dctype_str[id.dctype]);
	}
	return 0;
}

bool nvmf_is_registration_supported(nvme_ctrl_t c)
{
	if (!c->cntrltype || !c->dctype)
		if (nvme_fetch_cntrltype_dctype_from_id(c))
			return false;

	return !strcmp(c->dctype, "ddc") || !strcmp(c->dctype, "cdc");
}

int nvmf_register_ctrl(nvme_ctrl_t c, enum nvmf_dim_tas tas, __u32 *result)
{
	if (!nvmf_is_registration_supported(c)) {
		errno = ENOTSUP;
		return -1;
	}

	/* We're registering our source address with the DC. To do
	 * that, we can simply send an empty string. This tells the DC
	 * to retrieve the source address from the socket and use that
	 * as the registration address.
	 */
	return nvmf_dim(c, tas, NVMF_TRTYPE_TCP, nvme_get_adrfam(c), "", NULL, result);
}