summaryrefslogblamecommitdiffstats
path: root/libblkid/partitions.c
blob: 93ec4d224e23b4a053c816043d510082d34c54e2 (plain) (tree)
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








































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































                                                                                                    
/*
 * partitions - partition tables parsing
 *
 * Copyright (C) 2008-2009 Karel Zak <kzak@redhat.com>
 *
 * This file may be redistributed under the terms of the
 * GNU Lesser General Public License.
 *
 */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdint.h>
#include <inttypes.h>
#include <stdarg.h>

#include "partitions.h"
#include "sysfs.h"

/**
 * SECTION: partitions
 * @title: Partitions probing
 * @short_description: partitions tables detection and parsing
 *
 * This chain supports binary and NAME=value interfaces, but complete PT
 * description is provided by binary interface only. The libblkid prober is
 * compatible with kernel partition tables parser. The parser does not return
 * empty (size=0) partitions or special hidden partitions.
 *
 * NAME=value interface, supported tags:
 *
 * @PTTYPE: partition table type (dos, gpt, etc.).
 *
 * @PART_ENTRY_SCHEME: partition table type
 *
 * @PART_ENTRY_NAME: partition name (gpt and mac only)
 *
 * @PART_ENTRY_UUID: partition UUID (gpt only)
 *
 * @PART_ENTRY_TYPE: partition type, 0xNN (e.g 0x82) or type UUID (gpt only) or type string (mac)
 *
 * @PART_ENTRY_FLAGS: partition flags (e.g. boot_ind) or  attributes (e.g. gpt attributes)
 *
 * @PART_ENTRY_NUMBER: partition number
 *
 * @PART_ENTRY_OFFSET: the begin of the partition
 *
 * @PART_ENTRY_SIZE: size of the partition
 *
 * @PART_ENTRY_DISK: whole-disk maj:min
 *
 * Example:
 *
 * <informalexample>
 *  <programlisting>
 * blkid_probe pr;
 * const char *ptname;
 *
 * pr = blkid_new_probe_from_filename(devname);
 * if (!pr)
 *	err("%s: faild to open device", devname);
 *
 * blkid_probe_enable_partitions(pr, TRUE);
 * blkid_do_fullprobe(pr);
 *
 * blkid_probe_lookup_value(pr, "PTTYPE", &ptname, NULL);
 * printf("%s partition type detected\n", pttype);
 *
 * blkid_free_probe(pr);
 *
 * // don't forget to check return codes in your code!
 *  </programlisting>
 * </informalexample>
 *
 * Binary interface:
 *
 * <informalexample>
 *  <programlisting>
 * blkid_probe pr;
 * blkid_partlist ls;
 * int nparts, i;
 *
 * pr = blkid_new_probe_from_filename(devname);
 * if (!pr)
 *	err("%s: faild to open device", devname);
 *
 * ls = blkid_probe_get_partitions(pr);
 * nparts = blkid_partlist_numof_partitions(ls);
 *
 * for (i = 0; i < nparts; i++) {
 *      blkid_partition par = blkid_partlist_get_partition(ls, i);
 *      printf("#%d: %llu %llu  0x%x",
 *               blkid_partition_get_partno(par),
 *               blkid_partition_get_start(par),
 *               blkid_partition_get_size(par),
 *               blkid_partition_get_type(par));
 * }
 *
 * blkid_free_probe(pr);
 *
 * // don't forget to check return codes in your code!
 *  </programlisting>
 * </informalexample>
 */

/*
 * Chain driver function
 */
static int partitions_probe(blkid_probe pr, struct blkid_chain *chn);
static void partitions_free_data(blkid_probe pr, void *data);

/*
 * Partitions chain probing functions
 */
static const struct blkid_idinfo *idinfos[] =
{
	&aix_pt_idinfo,
	&sgi_pt_idinfo,
	&sun_pt_idinfo,
	&dos_pt_idinfo,
	&gpt_pt_idinfo,
	&mac_pt_idinfo,
	&ultrix_pt_idinfo,
	&bsd_pt_idinfo,
	&unixware_pt_idinfo,
	&solaris_x86_pt_idinfo,
	&minix_pt_idinfo
};

/*
 * Driver definition
 */
const struct blkid_chaindrv partitions_drv = {
	.id           = BLKID_CHAIN_PARTS,
	.name         = "partitions",
	.dflt_enabled = FALSE,
	.idinfos      = idinfos,
	.nidinfos     = ARRAY_SIZE(idinfos),
	.has_fltr     = TRUE,
	.probe        = partitions_probe,
	.safeprobe    = partitions_probe,
	.free_data    = partitions_free_data
};


/*
 * For compatibility with the rest of libblkid API (with the old high-level
 * API) we use completely opaque typedefs for all structs. Don't forget that
 * the final blkid_* types are pointers! See blkid.h.
 *
 * [Just for the record, I hate typedef for pointers --kzak]
 */

/* exported as opaque type "blkid_parttable" */
struct blkid_struct_parttable {
	const char	*type;		/* partition table type */
	blkid_loff_t	offset;		/* begin of the partition table */
	int		nparts;		/* number of partitions */
	blkid_partition	parent;		/* parent of nested partition table */
	char		id[37];		/* PT identifier (e.g. UUID for GPT) */

	struct list_head t_tabs;	/* all tables */
};

/* exported as opaque type "blkid_partition" */
struct blkid_struct_partition {
	blkid_loff_t	start;		/* begin of the partition */
	blkid_loff_t	size;		/* size of the partitions */

	int		type;		/* partition type */
	char		typestr[37];	/* partition type string (GPT and Mac) */

	unsigned long long flags;	/* partition flags / attributes */

	int		partno;		/* partition number */
	char		uuid[37];	/* UUID (when supported by PT), e.g GPT */
	unsigned char	name[128];	/* Partition in UTF8 name (when supporte by PT), e.g. Mac */

	blkid_parttable	tab;		/* partition table */
};

/* exported as opaque type "blkid_partlist" */
struct blkid_struct_partlist {
	int		next_partno;	/* next partition number */
	blkid_partition next_parent;	/* next parent if parsing nested PT */

	int		nparts;		/* number of partitions */
	int		nparts_max;	/* max.number of partitions */
	blkid_partition	parts;		/* array of partitions */

	struct list_head l_tabs;	/* list of partition tables */
};

static int blkid_partitions_probe_partition(blkid_probe pr);

/**
 * blkid_probe_enable_partitions:
 * @pr: probe
 * @enable: TRUE/FALSE
 *
 * Enables/disables the partitions probing for non-binary interface.
 *
 * Returns: 0 on success, or -1 in case of error.
 */
int blkid_probe_enable_partitions(blkid_probe pr, int enable)
{
	if (!pr)
		return -1;
	pr->chains[BLKID_CHAIN_PARTS].enabled = enable;
	return 0;
}

/**
 * blkid_probe_set_partitions_flags:
 * @pr: prober
 * @flags: BLKID_PARTS_* flags
 *
 * Sets probing flags to the partitions prober. This function is optional.
 *
 * Returns: 0 on success, or -1 in case of error.
 */
int blkid_probe_set_partitions_flags(blkid_probe pr, int flags)
{
	if (!pr)
		return -1;
	pr->chains[BLKID_CHAIN_PARTS].flags = flags;
	return 0;
}

/**
 * blkid_probe_reset_partitions_filter:
 * @pr: prober
 *
 * Resets partitions probing filter
 *
 * Returns: 0 on success, or -1 in case of error.
 */
int blkid_probe_reset_partitions_filter(blkid_probe pr)
{
	return __blkid_probe_reset_filter(pr, BLKID_CHAIN_PARTS);
}

/**
 * blkid_probe_invert_partitions_filter:
 * @pr: prober
 *
 * Inverts partitions probing filter
 *
 * Returns: 0 on success, or -1 in case of error.
 */
int blkid_probe_invert_partitions_filter(blkid_probe pr)
{
	return __blkid_probe_invert_filter(pr, BLKID_CHAIN_PARTS);
}

/**
 * blkid_probe_filter_partitions_type:
 * @pr: prober
 * @flag: filter BLKID_FLTR_{NOTIN,ONLYIN} flag
 * @names: NULL terminated array of probing function names (e.g. "vfat").
 *
 *  %BLKID_FLTR_NOTIN  - probe for all items which are NOT IN @names
 *
 *  %BLKID_FLTR_ONLYIN - probe for items which are IN @names
 *
 * Returns: 0 on success, or -1 in case of error.
 */
int blkid_probe_filter_partitions_type(blkid_probe pr, int flag, char *names[])
{
	return __blkid_probe_filter_types(pr, BLKID_CHAIN_PARTS, flag, names);
}

/**
 * blkid_probe_get_partitions:
 * @pr: probe
 *
 * This is a binary interface for partitions. See also blkid_partlist_*
 * functions.
 *
 * This function is independent on blkid_do_[safe,full]probe() and
 * blkid_probe_enable_partitions() calls.
 *
 * WARNING: the returned object will be overwritten by the next
 *          blkid_probe_get_partitions() call for the same @pr. If you want to
 *          use more blkid_partlist objects in the same time you have to create
 *          more blkid_probe handlers (see blkid_new_probe()).
 *
 * Returns: list of partitions, or NULL in case of error.
 */
blkid_partlist blkid_probe_get_partitions(blkid_probe pr)
{
	return (blkid_partlist) blkid_probe_get_binary_data(pr,
			&pr->chains[BLKID_CHAIN_PARTS]);
}

/* for internal usage only */
blkid_partlist blkid_probe_get_partlist(blkid_probe pr)
{
	return (blkid_partlist) pr->chains[BLKID_CHAIN_PARTS].data;
}

static void blkid_probe_set_partlist(blkid_probe pr, blkid_partlist ls)
{
	pr->chains[BLKID_CHAIN_PARTS].data = ls;
}

static void ref_parttable(blkid_parttable tab)
{
	tab->nparts++;
}

static void unref_parttable(blkid_parttable tab)
{
	tab->nparts--;

	if (tab->nparts <= 0) {
		list_del(&tab->t_tabs);
		free(tab);
	}
}

/* free all allocated parttables */
static void free_parttables(blkid_partlist ls)
{
	if (!ls || !ls->l_tabs.next)
		return;

	/* remove unassigned partition tables */
	while (!list_empty(&ls->l_tabs)) {
		blkid_parttable tab = list_entry(ls->l_tabs.next,
					struct blkid_struct_parttable, t_tabs);
		unref_parttable(tab);
	}
}

static void reset_partlist(blkid_partlist ls)
{
	if (!ls)
		return;

	free_parttables(ls);

	if (ls->next_partno) {
		/* already initialized - reset */
		int tmp_nparts = ls->nparts_max;
		blkid_partition tmp_parts = ls->parts;

		memset(ls, 0, sizeof(struct blkid_struct_partlist));

		ls->nparts_max = tmp_nparts;
		ls->parts = tmp_parts;
	}

	ls->nparts = 0;
	ls->next_partno = 1;
	INIT_LIST_HEAD(&ls->l_tabs);

	DBG(DEBUG_LOWPROBE, printf("partlist reset\n"));
}

static blkid_partlist partitions_init_data(struct blkid_chain *chn)
{
	blkid_partlist ls;

	if (chn->data)
		ls = (blkid_partlist) chn->data;
	else {
		/* allocate the new list of partitions */
		ls = calloc(1, sizeof(struct blkid_struct_partlist));
		if (!ls)
			return NULL;
		chn->data = (void *) ls;
	}

	reset_partlist(ls);

	DBG(DEBUG_LOWPROBE,
		printf("parts: initialized partitions list (%p, size=%d)\n",
		ls, ls->nparts_max));
	return ls;
}

static void partitions_free_data(blkid_probe pr __attribute__((__unused__)),
				 void *data)
{
	blkid_partlist ls = (blkid_partlist) data;

	if (!ls)
		return;

	free_parttables(ls);

	/* deallocate partitions and partlist */
	free(ls->parts);
	free(ls);
}

blkid_parttable blkid_partlist_new_parttable(blkid_partlist ls,
				const char *type, blkid_loff_t offset)
{
	blkid_parttable tab;

	tab = calloc(1, sizeof(struct blkid_struct_parttable));
	if (!tab)
		return NULL;
	tab->type = type;
	tab->offset = offset;
	tab->parent = ls->next_parent;

	INIT_LIST_HEAD(&tab->t_tabs);
	list_add_tail(&tab->t_tabs, &ls->l_tabs);

	DBG(DEBUG_LOWPROBE,
		printf("parts: create a new partition table "
		       "(%p, type=%s, offset=%"PRId64")\n", tab, type, offset));
	return tab;
}

static blkid_partition new_partition(blkid_partlist ls, blkid_parttable tab)
{
	blkid_partition par;

	if (ls->nparts + 1 > ls->nparts_max) {
		/* Linux kernel has DISK_MAX_PARTS=256, but it's too much for
		 * generic Linux machine -- let start with 32 partititions.
		 */
		ls->parts = realloc(ls->parts, (ls->nparts_max + 32) *
					sizeof(struct blkid_struct_partition));
		if (!ls->parts)
			return NULL;
		ls->nparts_max += 32;
	}

	par = &ls->parts[ls->nparts++];
	memset(par, 0, sizeof(struct blkid_struct_partition));

	ref_parttable(tab);
	par->tab = tab;
	par->partno = blkid_partlist_increment_partno(ls);

	return par;
}

blkid_partition blkid_partlist_add_partition(blkid_partlist ls,
					blkid_parttable tab,
					blkid_loff_t start, blkid_loff_t size)
{
	blkid_partition par = new_partition(ls, tab);

	if (!par)
		return NULL;

	par->start = start;
	par->size = size;

	DBG(DEBUG_LOWPROBE,
		printf("parts: add partition (%p start=%"
		PRId64 ", size=%" PRId64 ", table=%p)\n",
		par, par->start, par->size, tab));
	return par;
}

/* allows to modify used partitions numbers (for example for logical partitions) */
int blkid_partlist_set_partno(blkid_partlist ls, int partno)
{
	if (!ls)
		return -1;
	ls->next_partno = partno;
	return 0;
}

int blkid_partlist_increment_partno(blkid_partlist ls)
{
	return ls ? ls->next_partno++ : -1;
}

/* allows to set "parent" for the next nested partition */
int blkid_partlist_set_parent(blkid_partlist ls, blkid_partition par)
{
	if (!ls)
		return -1;
	ls->next_parent = par;
	return 0;
}

blkid_partition blkid_partlist_get_parent(blkid_partlist ls)
{
	if (!ls)
		return NULL;
	return ls->next_parent;
}

int blkid_partitions_need_typeonly(blkid_probe pr)
{
	struct blkid_chain *chn = blkid_probe_get_chain(pr);

	return chn && chn->data && chn->binary ? FALSE : TRUE;
}

/* get private chain flags */
int blkid_partitions_get_flags(blkid_probe pr)
{
	struct blkid_chain *chn = blkid_probe_get_chain(pr);

	return chn ? chn->flags : 0;
}

/* check if @start and @size are within @par partition */
int blkid_is_nested_dimension(blkid_partition par,
			blkid_loff_t start, blkid_loff_t size)
{
	blkid_loff_t pstart;
	blkid_loff_t psize;

	if (!par)
		return 0;

	pstart = blkid_partition_get_start(par);
	psize = blkid_partition_get_size(par);

	if (start < pstart || start + size > pstart + psize)
		return 0;

	return 1;
}

static int idinfo_probe(blkid_probe pr, const struct blkid_idinfo *id,
			struct blkid_chain *chn)
{
	const struct blkid_idmag *mag = NULL;
	blkid_loff_t off;
	int rc = 1;		/* = nothing detected */

	if (pr->size <= 0 || (id->minsz && id->minsz > pr->size))
		goto nothing;	/* the device is too small */

	if (blkid_probe_get_idmag(pr, id, &off, &mag))
		goto nothing;

	/* final check by probing function */
	if (id->probefunc) {
		DBG(DEBUG_LOWPROBE, printf(
			"%s: ---> call probefunc()\n", id->name));
		rc = id->probefunc(pr, mag);
	        if (rc == -1) {
			/* reset after error */
			reset_partlist(blkid_probe_get_partlist(pr));
			if (chn && !chn->binary)
				blkid_probe_chain_reset_vals(pr, chn);
			DBG(DEBUG_LOWPROBE, printf(
				"%s probefunc failed\n", id->name));
		}
		if (rc == 0 && mag && chn && !chn->binary)
			rc = blkid_probe_set_magic(pr, off, mag->len,
					(unsigned char *) mag->magic);

		DBG(DEBUG_LOWPROBE, printf(
			"%s: <--- (rc = %d)\n", id->name, rc));
	}

nothing:
	return rc;
}

/*
 * The blkid_do_probe() backend.
 */
static int partitions_probe(blkid_probe pr, struct blkid_chain *chn)
{
	int rc = 1;
	size_t i;

	if (!pr || chn->idx < -1)
		return -1;
	blkid_probe_chain_reset_vals(pr, chn);

	if (chn->binary)
		partitions_init_data(chn);

	if (!pr->wipe_size && (pr->prob_flags & BLKID_PROBE_FL_IGNORE_PT))
		goto details_only;

	DBG(DEBUG_LOWPROBE,
		printf("--> starting probing loop [PARTS idx=%d]\n",
		chn->idx));

	i = chn->idx < 0 ? 0 : chn->idx + 1U;

	for ( ; i < ARRAY_SIZE(idinfos); i++) {
		const char *name;

		chn->idx = i;

		/* apply filter */
		if (chn->fltr && blkid_bmp_get_item(chn->fltr, i))
			continue;

		/* apply checks from idinfo */
		if (idinfo_probe(pr, idinfos[i], chn) != 0)
			continue;

		name = idinfos[i]->name;

		/* all checks passed */
		if (!chn->binary)
			blkid_probe_set_value(pr, "PTTYPE",
						(unsigned char *) name,
						strlen(name) + 1);
		DBG(DEBUG_LOWPROBE,
			printf("<-- leaving probing loop (type=%s) [PARTS idx=%d]\n",
			name, chn->idx));
		rc = 0;
		break;
	}

	if (rc == 1) {
		DBG(DEBUG_LOWPROBE,
			printf("<-- leaving probing loop (failed) [PARTS idx=%d]\n",
			chn->idx));
	}

details_only:
	/*
	 * Gather PART_ENTRY_* values if the current device is a partition.
	 */
	if (!chn->binary &&
	    (blkid_partitions_get_flags(pr) & BLKID_PARTS_ENTRY_DETAILS)) {

		if (!blkid_partitions_probe_partition(pr))
			rc = 0;
	}

	return rc;
}

/* Probe for nested partition table within the parental partition */
int blkid_partitions_do_subprobe(blkid_probe pr, blkid_partition parent,
		const struct blkid_idinfo *id)
{
	blkid_probe prc;
	int rc = 1;
	blkid_partlist ls;
	blkid_loff_t sz, off;

	DBG(DEBUG_LOWPROBE, printf(
		"parts: ----> %s subprobe requested (parent=%p)\n",
		id->name, parent));

	if (!pr || !parent || !parent->size)
		return -1;

	/* range defined by parent */
	sz = ((blkid_loff_t) parent->size) << 9;
	off = ((blkid_loff_t) parent->start) << 9;

	if (off < pr->off || pr->off + pr->size < off + sz) {
		DBG(DEBUG_LOWPROBE, printf(
			"ERROR: parts: <---- '%s' subprobe: overflow detected.\n",
			id->name));
		return -1;
	}

	/* create private prober */
	prc = blkid_clone_probe(pr);
	if (!prc)
		return -1;

	blkid_probe_set_dimension(prc, off, sz);

	/* clone is always with reset chain, fix it */
	prc->cur_chain = blkid_probe_get_chain(pr);

	/*
	 * Set 'parent' to the current list of the partitions and use the list
	 * in cloned prober (so the cloned prober will extend the current list
	 * of partitions rather than create a new).
	 */
	ls = blkid_probe_get_partlist(pr);
	blkid_partlist_set_parent(ls, parent);

	blkid_probe_set_partlist(prc, ls);

	rc = idinfo_probe(prc, id, blkid_probe_get_chain(pr));

	blkid_probe_set_partlist(prc, NULL);
	blkid_partlist_set_parent(ls, NULL);

	blkid_free_probe(prc);	/* free cloned prober */

	DBG(DEBUG_LOWPROBE, printf(
		"parts: <---- %s subprobe done (parent=%p, rc=%d)\n",
		id->name, parent, rc));

	return rc;
}

static int blkid_partitions_probe_partition(blkid_probe pr)
{
	int rc = 1;
	blkid_probe disk_pr = NULL;
	blkid_partlist ls;
	blkid_partition par;
	dev_t devno;

	devno = blkid_probe_get_devno(pr);
	if (!devno)
		goto nothing;

	disk_pr = blkid_probe_get_wholedisk_probe(pr);
	if (!disk_pr)
		goto nothing;

	/* parse PT */
	ls = blkid_probe_get_partitions(disk_pr);
	if (!ls)
		goto nothing;

	par = blkid_partlist_devno_to_partition(ls, devno);
	if (par) {
		const char *v;
		blkid_parttable tab = blkid_partition_get_table(par);
		dev_t disk = blkid_probe_get_devno(disk_pr);

		if (tab) {
			v = blkid_parttable_get_type(tab);
			if (v)
				blkid_probe_set_value(pr, "PART_ENTRY_SCHEME",
					(unsigned char *) v, strlen(v) + 1);
		}

		v = blkid_partition_get_name(par);
		if (v)
			blkid_probe_set_value(pr, "PART_ENTRY_NAME",
				(unsigned char *) v, strlen(v) + 1);

		v = blkid_partition_get_uuid(par);
		if (v)
			blkid_probe_set_value(pr, "PART_ENTRY_UUID",
				(unsigned char *) v, strlen(v) + 1);

		/* type */
		v = blkid_partition_get_type_string(par);
		if (v)
			blkid_probe_set_value(pr, "PART_ENTRY_TYPE",
				(unsigned char *) v, strlen(v) + 1);
		else
			blkid_probe_sprintf_value(pr, "PART_ENTRY_TYPE",
				"0x%x", blkid_partition_get_type(par));

		if (blkid_partition_get_flags(par))
			blkid_probe_sprintf_value(pr, "PART_ENTRY_FLAGS",
				"0x%llx", blkid_partition_get_flags(par));

		blkid_probe_sprintf_value(pr, "PART_ENTRY_NUMBER",
				"%d", blkid_partition_get_partno(par));

		blkid_probe_sprintf_value(pr, "PART_ENTRY_OFFSET", "%jd",
				blkid_partition_get_start(par));
		blkid_probe_sprintf_value(pr, "PART_ENTRY_SIZE", "%jd",
				blkid_partition_get_size(par));

		blkid_probe_sprintf_value(pr, "PART_ENTRY_DISK", "%u:%u",
				major(disk), minor(disk));
	}
	rc = 0;
nothing:
	return rc;
}

/*
 * Returns 1 if the device is whole-disk and the area specified by @offset and
 * @size is covered by any partition.
 */
int blkid_probe_is_covered_by_pt(blkid_probe pr,
				 blkid_loff_t offset, blkid_loff_t size)
{
	blkid_probe prc;
	blkid_partlist ls = NULL;
	blkid_loff_t start, end;
	int nparts, i, rc = 0;

	DBG(DEBUG_LOWPROBE, printf(
		"=> checking if off=%jd size=%jd covered by PT\n",
		offset, size));

	prc = blkid_clone_probe(pr);
	if (!prc)
		goto done;

	ls = blkid_probe_get_partitions(prc);
	if (!ls)
		goto done;

	nparts = blkid_partlist_numof_partitions(ls);
	if (!nparts)
		goto done;

	end = (offset + size) >> 9;
	start = offset >> 9;

	/* check if the partition table fits into the device */
	for (i = 0; i < nparts; i++) {
		blkid_partition par = &ls->parts[i];

		if (par->start + par->size > (pr->size >> 9)) {
			DBG(DEBUG_LOWPROBE, printf("partition #%d overflows "
				"device (off=%" PRId64 " size=%" PRId64 ")\n",
				par->partno, par->start, par->size));
			goto done;
		}
	}

	/* check if the requested area is covered by PT */
	for (i = 0; i < nparts; i++) {
		blkid_partition par = &ls->parts[i];

		if (start >= par->start && end <= par->start + par->size) {
			rc = 1;
			break;
		}
	}
done:
	blkid_free_probe(prc);

	DBG(DEBUG_LOWPROBE, printf("<= %s covered by PT\n", rc ? "IS" : "NOT"));
	return rc;
}

/**
 * blkid_known_pttype:
 * @pttype: partiton name
 *
 * Returns: 1 for known or 0 for unknown partition type.
 */
int blkid_known_pttype(const char *pttype)
{
	size_t i;

	if (!pttype)
		return 0;

	for (i = 0; i < ARRAY_SIZE(idinfos); i++) {
		const struct blkid_idinfo *id = idinfos[i];
		if (strcmp(id->name, pttype) == 0)
			return 1;
	}
	return 0;
}

/**
 * blkid_partlist_numof_partitions:
 * @ls: partitions list
 *
 * Returns: number of partitions in the list or -1 in case of error.
 */
int blkid_partlist_numof_partitions(blkid_partlist ls)
{
	return ls ? ls->nparts : -1;
}

/**
 * blkid_partlist_get_table:
 * @ls: partitions list
 *
 * Returns: top-level partition table or NULL of there is not a partition table
 * on the device.
 */
blkid_parttable blkid_partlist_get_table(blkid_partlist ls)
{
	if (!ls || list_empty(&ls->l_tabs))
		return NULL;

	return list_entry(ls->l_tabs.next,
			struct blkid_struct_parttable, t_tabs);
}


/**
 * blkid_partlist_get_partition:
 * @ls: partitions list
 * @n: partition number in range 0..N, where 'N' is blkid_partlist_numof_partitions().
 *
 * It's possible that the list of partitions is *empty*, but there is a valid
 * partition table on the disk. This happen when on-disk details about
 * partitions are unknown or the partition table is empty.
 *
 * See also blkid_partlist_get_table().
 *
 * Returns: partition object or NULL in case or error.
 */
blkid_partition blkid_partlist_get_partition(blkid_partlist ls, int n)
{
	if (!ls || n < 0 || n >= ls->nparts)
		return NULL;

	return &ls->parts[n];
}

/**
 * blkid_partlist_devno_to_partition:
 * @ls: partitions list
 * @devno: requested partition
 *
 * This function tries to get start and size for @devno from sysfs and
 * returns a partition from @ls which matches with the values from sysfs.
 *
 * This function is necessary when you want to make a relation between an entry
 * in the partition table (@ls) and block devices in your system.
 *
 * Returns: partition object or NULL in case or error.
 */
blkid_partition blkid_partlist_devno_to_partition(blkid_partlist ls, dev_t devno)
{
	struct sysfs_cxt sysfs;
	uint64_t start, size;
	int i, rc, partno = 0;

	if (!ls)
		return NULL;

	DBG(DEBUG_LOWPROBE,
		printf("triyng to convert devno 0x%llx to partition\n",
			(long long) devno));

	if (sysfs_init(&sysfs, devno, NULL)) {
		DBG(DEBUG_LOWPROBE, printf("failed t init sysfs context\n"));
		return NULL;
	}
	rc = sysfs_read_u64(&sysfs, "size", &size);
	if (!rc) {
		rc = sysfs_read_u64(&sysfs, "start", &start);
		if (rc) {
			/* try to get partition number from DM uuid.
			 */
			char *uuid = sysfs_strdup(&sysfs, "dm/uuid");
			char *tmp = uuid;
			char *prefix = uuid ? strsep(&tmp, "-") : NULL;

			if (prefix && strncasecmp(prefix, "part", 4) == 0) {
				char *end = NULL;

				partno = strtol(prefix + 4, &end, 10);
				if (prefix == end || (end && *end))
					partno = 0;
				else
					rc = 0;		/* success */
			}
			free(uuid);
		}
	}

	sysfs_deinit(&sysfs);

	if (rc)
		return NULL;

	if (partno) {
		DBG(DEBUG_LOWPROBE, printf("mapped by DM, using partno %d\n", partno));

		/*
		 * Partition mapped by kpartx does not provide "start" offset
		 * in /sys, but if we know partno and size of the partition
		 * that we can probably make the releation bettween the device
		 * and an entry in partition table.
		 */
		 for (i = 0; i < ls->nparts; i++) {
			 blkid_partition par = &ls->parts[i];

			 if (partno != blkid_partition_get_partno(par))
				 continue;

			 if ((blkid_loff_t) size == blkid_partition_get_size(par) ||
			     (blkid_partition_is_extended(par) && size <= 1024))
				 return par;

		 }
		 return NULL;
	}

	DBG(DEBUG_LOWPROBE, printf("searching by offset/size\n"));

	for (i = 0; i < ls->nparts; i++) {
		blkid_partition par = &ls->parts[i];

		if (blkid_partition_get_start(par) == (blkid_loff_t) start &&
		    blkid_partition_get_size(par) == (blkid_loff_t) size)
			return par;

		/* exception for extended dos partitions */
		if (blkid_partition_get_start(par) == (blkid_loff_t) start &&
		    blkid_partition_is_extended(par) && size <= 1024)
			return par;

	}

	DBG(DEBUG_LOWPROBE, printf("not found partition for device\n"));
	return NULL;
}

int blkid_parttable_set_id(blkid_parttable tab, const unsigned char *id)
{
	if (!tab)
		return -1;

	if (strcmp(tab->type, "gpt") == 0)
		blkid_unparse_uuid(id, tab->id, sizeof(tab->id));
	else if (strcmp(tab->type, "dos") == 0)
		strncpy(tab->id, (const char *) id, sizeof(tab->id));

	return 0;
}

/**
 * blkid_parttable_get_id:
 * @tab: partition table
 *
 * The ID is GPT disk UUID or DOS disk ID (in hex format).
 *
 * Returns: partition table ID (for example GPT disk UUID) or NULL
 */
const char *blkid_parttable_get_id(blkid_parttable tab)
{
	return tab && tab->id && *tab->id ? tab->id : NULL;
}


int blkid_partition_set_type(blkid_partition par, int type)
{
	if (!par)
		return -1;
	par->type = type;
	return 0;
}

/**
 * blkid_parttable_get_type:
 * @tab: partition table
 *
 * Returns: partition table type (type name, e.g. "dos", "gpt", ...)
 */
const char *blkid_parttable_get_type(blkid_parttable tab)
{
	return tab ? tab->type : NULL;
}

/**
 * blkid_parttable_get_parent:
 * @tab: partition table
 *
 * Returns: parent for nexted partitition tables or NULL.
 */
blkid_partition blkid_parttable_get_parent(blkid_parttable tab)
{
	return tab ? tab->parent : NULL;
}

/**
 * blkid_parttable_get_offset:
 * @tab: partition table
 *
 * Note the position is relative to begin of the device as defined by
 * blkid_probe_set_device() for primary partition table, and relative
 * to parental partition for nested patition tables.
 *
 * <informalexample>
 *   <programlisting>
 * off_t offset;
 * blkid_partition parent = blkid_parttable_get_parent(tab);
 *
 * offset = blkid_parttable_get_offset(tab);
 *
 * if (parent)
 *      / * 'tab' is nested partition table * /
 *	offset += blkid_partition_get_start(parent);
 *   </programlisting>
 * </informalexample>

 * Returns: position (in bytes) of the partition table or -1 in case of error.
 *
 */
blkid_loff_t blkid_parttable_get_offset(blkid_parttable tab)
{
	return tab ? tab->offset : -1;
}

/**
 * blkid_partition_get_table:
 * @par: partition
 *
 * The "parttable" describes partition table. The table is usually the same for
 * all partitions -- except nested partition tables.
 *
 * For example bsd, solaris, etc. use a nested partition table within
 * standard primary dos partition:
 *
 * <informalexample>
 *   <programlisting>
 *
 *  -- dos partition table
 *  0: sda1     dos primary partition
 *  1: sda2     dos primary partition
 *     -- bsd partition table (with in sda2)
 *  2:    sda5  bds partition
 *  3:    sda6  bds partition
 *
 *   </programlisting>
 * </informalexample>
 *
 * The library does not to use a separate partition table object for dos logical
 * partitions (partitions within extended partition). It's possible to
 * differentiate between logical, extended and primary partitions by
 *
 *	blkid_partition_is_{extended,primary,logical}().
 *
 * Returns: partition table object or NULL in case of error.
 */
blkid_parttable blkid_partition_get_table(blkid_partition par)
{
	return par ? par->tab : NULL;
}

static int partition_get_logical_type(blkid_partition par)
{
	blkid_parttable tab;

	if (!par)
		return -1;

	tab = blkid_partition_get_table(par);
	if (!tab || !tab->type)
		return -1;

	if (tab->parent)
		return 'L';  /* report nested partitions as logical */

	if (!strcmp(tab->type, "dos")) {
		if (par->partno > 4)
			return 'L';	/* logical */

	        if(par->type == BLKID_DOS_EXTENDED_PARTITION ||
                   par->type == BLKID_W95_EXTENDED_PARTITION ||
		   par->type == BLKID_LINUX_EXTENDED_PARTITION)
			return 'E';
	}
	return 'P';
}

/**
 * blkid_partition_is_primary:
 * @par: partition
 *
 * Note, this function returns FALSE for DOS extended partitions and
 * all partitions in nested partition tables.
 *
 * Returns: 1 if the partitions is primary partition or 0 if not.
 */
int blkid_partition_is_primary(blkid_partition par)
{
	return partition_get_logical_type(par) == 'P' ? TRUE : FALSE;
}

/**
 * blkid_partition_is_extended:
 * @par: partition
 *
 * Returns: 1 if the partitions is extended (dos, windows or linux)
 * partition or 0 if not.
 */
int blkid_partition_is_extended(blkid_partition par)
{
	return partition_get_logical_type(par) == 'E' ? TRUE : FALSE;
}

/**
 * blkid_partition_is_logical:
 * @par: partition
 *
 * Note that this function returns TRUE for all partitions in all
 * nested partition tables (e.g. BSD labels).
 *
 * Returns: 1 if the partitions is logical partition or 0 if not.
 */
int blkid_partition_is_logical(blkid_partition par)
{
	return partition_get_logical_type(par) == 'L' ? TRUE : FALSE;
}

static void set_string(unsigned char *item, size_t max,
				const unsigned char *data, size_t len)
{
	if (len >= max)
		len = max - 1;

	memcpy(item, data, len);
	item[len] = '\0';

	blkid_rtrim_whitespace(item);
}

int blkid_partition_set_name(blkid_partition par,
		const unsigned char *name, size_t len)
{
	if (!par)
		return -1;

	set_string(par->name, sizeof(par->name), name, len);
	return 0;
}

int blkid_partition_set_utf8name(blkid_partition par, const unsigned char *name,
		size_t len, int enc)
{
	if (!par)
		return -1;

	blkid_encode_to_utf8(enc, par->name, sizeof(par->name), name, len);
	blkid_rtrim_whitespace(par->name);
	return 0;
}

int blkid_partition_set_uuid(blkid_partition par, const unsigned char *uuid)
{
	if (!par)
		return -1;

	blkid_unparse_uuid(uuid, par->uuid, sizeof(par->uuid));
	return 0;
}

/**
 * blkid_partition_get_name:
 * @par: partition
 *
 * Returns: partition name string if supported by PT (e.g. Mac) or NULL.
 */
const char *blkid_partition_get_name(blkid_partition par)
{
	return par && *par->name ? (char *) par->name : NULL;
}

/**
 * blkid_partition_get_uuid:
 * @par: partition
 *
 * Returns: partition UUID string if supported by PT (e.g. GPT) or NULL.
 */
const char *blkid_partition_get_uuid(blkid_partition par)
{
	return par && *par->uuid ? par->uuid : NULL;
}

/**
 * blkid_partition_get_partno:
 * @par: partition
 *
 * Returns: proposed partitin number (e.g. 'N' from sda'N') or -1 in case of
 * error. Note that the number is generate by library independenly on your OS.
 */
int blkid_partition_get_partno(blkid_partition par)
{
	return par ? par->partno : -1;
}

/**
 * blkid_partition_get_start:
 * @par: partition
 *
 * Be careful if you _not_ probe whole disk:
 *
 * 1) the offset is usully relative to begin of the disk -- but if you probe a
 *    fragment of the disk only -- then the offset could be still relative to
 *    the begin of the disk rather that relative to the fragment.
 *
 * 2) the offset for nested partitions could be releative to parent (e.g. Solaris)
 *    _or_ relative to the begin of the whole disk (e.g. bsd).
 *
 * You don't have to care about such details if you proble whole disk. In such
 * a case libblkid always returns the offset relative to the begin of the disk.
 *
 * Returns: start of the partition (in 512-sectors).
 */
blkid_loff_t blkid_partition_get_start(blkid_partition par)
{
	return par ? par->start : -1;
}

/**
 * blkid_partition_get_size:
 * @par: partition
 *
 * WARNING: be very careful when you work with MS-DOS extended partitions. The
 *          library always returns full size of the partition. If you want add
 *          the partition to the Linux system (BLKPG_ADD_PARTITION ioctl) you
 *          need to reduce the size of the partition to 1 or 2 blocks. The
 *          rest of the partition has to be unaccessible for mkfs or mkswap
 *          programs, we need a small space for boot loaders only.
 *
 *          For some unknown reason this (safe) practice is not to used for
 *          nested BSD, Solaris, ..., partition tables in Linux kernel.
 *
 * Returns: size of the partition (in 512-sectors).
 */
blkid_loff_t blkid_partition_get_size(blkid_partition par)
{
	return par ? par->size : -1;
}

/**
 * blkid_partition_get_type:
 * @par: partition
 *
 * Returns: partition type.
 */
int blkid_partition_get_type(blkid_partition par)
{
	return par->type;
}

/* Sets partition 'type' for PT where the type is defined by string rather
 * than by number
 */
int blkid_partition_set_type_string(blkid_partition par,
		const unsigned char *type, size_t len)
{
	if (!par)
		return -1;

	set_string((unsigned char *) par->typestr,
			sizeof(par->typestr), type, len);
	return 0;
}

/* Sets partition 'type' for PT where the type is defined by UUIDrather
 * than by number
 */
int blkid_partition_set_type_uuid(blkid_partition par, const unsigned char *uuid)
{
	if (!par)
		return -1;

	blkid_unparse_uuid(uuid, par->typestr, sizeof(par->typestr));
	return 0;
}

/**
 * blkid_partition_get_type_string:
 * @par: partition
 *
 * The type string is supported by a small subset of partition tables (e.g Mac
 * and EFI GPT).  Note that GPT uses type UUID and this function returns this
 * UUID as string.
 *
 * Returns: partition type string or NULL.
 */
const char *blkid_partition_get_type_string(blkid_partition par)
{
	return par && *par->typestr ? par->typestr : NULL;
}


int blkid_partition_set_flags(blkid_partition par, unsigned long long flags)
{
	if (!par)
		return -1;
	par->flags = flags;
	return 0;
}

/**
 * blkid_partition_get_flags
 * @par: partition
 *
 * Returns: partition flags (or attributes for gpt).
 */
unsigned long long blkid_partition_get_flags(blkid_partition par)
{
	return par->flags;
}