probe.c revision 45e338f5332a54295893dba2e32cc093d1316f60
1/*
2 * probe.c - identify a block device by its contents, and return a dev
3 *           struct with the details
4 *
5 * Copyright (C) 1999 by Andries Brouwer
6 * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o
7 * Copyright (C) 2001 by Andreas Dilger
8 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
9 *
10 * %Begin-Header%
11 * This file may be redistributed under the terms of the
12 * GNU Lesser General Public License.
13 * %End-Header%
14 */
15
16#include <stdio.h>
17#include <string.h>
18#include <stdlib.h>
19#include <unistd.h>
20#include <fcntl.h>
21#include <ctype.h>
22#include <sys/types.h>
23#ifdef HAVE_SYS_STAT_H
24#include <sys/stat.h>
25#endif
26#ifdef HAVE_SYS_MKDEV_H
27#include <sys/mkdev.h>
28#endif
29#ifdef __linux__
30#include <sys/utsname.h>
31#endif
32#ifdef HAVE_ERRNO_H
33#include <errno.h>
34#endif
35#include "blkidP.h"
36#include "uuid/uuid.h"
37#include "probe.h"
38
39static int figure_label_len(const unsigned char *label, int len)
40{
41	const unsigned char *end = label + len - 1;
42
43	while ((*end == ' ' || *end == 0) && end >= label)
44		--end;
45	if (end >= label) {
46		label = label;
47		return end - label + 1;
48	}
49	return 0;
50}
51
52static unsigned char *get_buffer(struct blkid_probe *pr,
53			  blkid_loff_t off, size_t len)
54{
55	ssize_t		ret_read;
56	unsigned char	*newbuf;
57
58	if (off + len <= SB_BUFFER_SIZE) {
59		if (!pr->sbbuf) {
60			pr->sbbuf = malloc(SB_BUFFER_SIZE);
61			if (!pr->sbbuf)
62				return NULL;
63			if (lseek(pr->fd, 0, SEEK_SET) < 0)
64				return NULL;
65			ret_read = read(pr->fd, pr->sbbuf, SB_BUFFER_SIZE);
66			if (ret_read < 0)
67				ret_read = 0;
68			pr->sb_valid = ret_read;
69		}
70		if (off+len > pr->sb_valid)
71			return NULL;
72		return pr->sbbuf + off;
73	} else {
74		if (len > pr->buf_max) {
75			newbuf = realloc(pr->buf, len);
76			if (newbuf == NULL)
77				return NULL;
78			pr->buf = newbuf;
79			pr->buf_max = len;
80		}
81		if (blkid_llseek(pr->fd, off, SEEK_SET) < 0)
82			return NULL;
83		ret_read = read(pr->fd, pr->buf, len);
84		if (ret_read != (ssize_t) len)
85			return NULL;
86		return pr->buf;
87	}
88}
89
90
91/*
92 * This is a special case code to check for an MDRAID device.  We do
93 * this special since it requires checking for a superblock at the end
94 * of the device.
95 */
96static int check_mdraid(int fd, unsigned char *ret_uuid)
97{
98	struct mdp_superblock_s *md;
99	blkid_loff_t		offset;
100	char			buf[4096];
101
102	if (fd < 0)
103		return -BLKID_ERR_PARAM;
104
105	offset = (blkid_get_dev_size(fd) & ~((blkid_loff_t)65535)) - 65536;
106
107	if (blkid_llseek(fd, offset, 0) < 0 ||
108	    read(fd, buf, 4096) != 4096)
109		return -BLKID_ERR_IO;
110
111	/* Check for magic number */
112	if (memcmp("\251+N\374", buf, 4) && memcmp("\374N+\251", buf, 4))
113		return -BLKID_ERR_PARAM;
114
115	if (!ret_uuid)
116		return 0;
117	*ret_uuid = 0;
118
119	/* The MD UUID is not contiguous in the superblock, make it so */
120	md = (struct mdp_superblock_s *)buf;
121	if (md->set_uuid0 || md->set_uuid1 || md->set_uuid2 || md->set_uuid3) {
122		memcpy(ret_uuid, &md->set_uuid0, 4);
123		memcpy(ret_uuid + 4, &md->set_uuid1, 12);
124	}
125	return 0;
126}
127
128static void set_uuid(blkid_dev dev, uuid_t uuid, const char *tag)
129{
130	char	str[37];
131
132	if (!uuid_is_null(uuid)) {
133		uuid_unparse(uuid, str);
134		blkid_set_tag(dev, tag ? tag : "UUID", str, sizeof(str));
135	}
136}
137
138static void get_ext2_info(blkid_dev dev, struct blkid_magic *id,
139			  unsigned char *buf)
140{
141	struct ext2_super_block *es = (struct ext2_super_block *) buf;
142	const char *label = 0;
143
144	DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",
145		   blkid_le32(es->s_feature_compat),
146		   blkid_le32(es->s_feature_incompat),
147		   blkid_le32(es->s_feature_ro_compat)));
148
149	if (strlen(es->s_volume_name))
150		label = es->s_volume_name;
151	blkid_set_tag(dev, "LABEL", label, sizeof(es->s_volume_name));
152
153	set_uuid(dev, es->s_uuid, 0);
154
155	if ((es->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
156	    !uuid_is_null(es->s_journal_uuid))
157		set_uuid(dev, es->s_journal_uuid, "EXT_JOURNAL");
158
159	if (strcmp(id->bim_type, "ext2") &&
160	    ((blkid_le32(es->s_feature_incompat) &
161	      EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0))
162		blkid_set_tag(dev, "SEC_TYPE", "ext2", sizeof("ext2"));
163}
164
165/*
166 * Check to see if a filesystem is in /proc/filesystems.
167 * Returns 1 if found, 0 if not
168 */
169static int fs_proc_check(const char *fs_name)
170{
171	FILE	*f;
172	char	buf[80], *cp, *t;
173
174	f = fopen("/proc/filesystems", "r");
175	if (!f)
176		return (0);
177	while (!feof(f)) {
178		if (!fgets(buf, sizeof(buf), f))
179			break;
180		cp = buf;
181		if (!isspace(*cp)) {
182			while (*cp && !isspace(*cp))
183				cp++;
184		}
185		while (*cp && isspace(*cp))
186			cp++;
187		if ((t = strchr(cp, '\n')) != NULL)
188			*t = 0;
189		if ((t = strchr(cp, '\t')) != NULL)
190			*t = 0;
191		if ((t = strchr(cp, ' ')) != NULL)
192			*t = 0;
193		if (!strcmp(fs_name, cp)) {
194			fclose(f);
195			return (1);
196		}
197	}
198	fclose(f);
199	return (0);
200}
201
202/*
203 * Check to see if a filesystem is available as a module
204 * Returns 1 if found, 0 if not
205 */
206static int check_for_modules(const char *fs_name)
207{
208#ifdef __linux__
209	struct utsname	uts;
210	FILE		*f;
211	char		buf[1024], *cp, *t;
212	int		i;
213
214	if (uname(&uts))
215		return (0);
216	snprintf(buf, sizeof(buf), "/lib/modules/%s/modules.dep", uts.release);
217
218	f = fopen(buf, "r");
219	if (!f)
220		return (0);
221	while (!feof(f)) {
222		if (!fgets(buf, sizeof(buf), f))
223			break;
224		if ((cp = strchr(buf, ':')) != NULL)
225			*cp = 0;
226		else
227			continue;
228		if ((cp = strrchr(buf, '/')) != NULL)
229			cp++;
230		else
231			cp = buf;
232		i = strlen(cp);
233		if (i > 3) {
234			t = cp + i - 3;
235			if (!strcmp(t, ".ko"))
236				*t = 0;
237		}
238		if (!strcmp(cp, fs_name)) {
239			fclose(f);
240			return (1);
241		}
242	}
243	fclose(f);
244#endif
245	return (0);
246}
247
248static int linux_version_code()
249{
250#ifdef __linux__
251	struct utsname	ut;
252	static		version_code = -1;
253	int		major, minor, rev;
254	char		*endptr;
255	const char 	*cp;
256
257	if (version_code > 0)
258		return version_code;
259
260	if (uname(&ut))
261		return 0;
262	cp = ut.release;
263
264	major = strtol(cp, &endptr, 10);
265	if (cp == endptr || *endptr != '.')
266		return 0;
267	cp = endptr + 1;
268	minor = strtol(cp, &endptr, 10);
269	if (cp == endptr || *endptr != '.')
270		return 0;
271	cp = endptr + 1;
272	rev = strtol(cp, &endptr, 10);
273	if (cp == endptr)
274		return 0;
275	version_code = (((major * 256) + minor) * 256) + rev;
276	return version_code;
277#else
278	return 0;
279#endif
280}
281
282#define EXT4_SUPPORTS_EXT2 (2 * 65536 + 6*256 + 29)
283
284static int system_supports_ext2(void)
285{
286	static time_t	last_check = 0;
287	static int	ret = -1;
288	time_t		now = time(0);
289
290	if (ret != -1 || (now - last_check) < 5)
291		return ret;
292	last_check = now;
293	ret = (fs_proc_check("ext2") || check_for_modules("ext2"));
294	return ret;
295}
296
297static int system_supports_ext4(void)
298{
299	static time_t	last_check = 0;
300	static int	ret = -1;
301	time_t		now = time(0);
302
303	if (ret != -1 || (now - last_check) < 5)
304		return ret;
305	last_check = now;
306	ret = (fs_proc_check("ext4") || check_for_modules("ext4"));
307	return ret;
308}
309
310static int system_supports_ext4dev(void)
311{
312	static time_t	last_check = 0;
313	static int	ret = -1;
314	time_t		now = time(0);
315
316	if (ret != -1 || (now - last_check) < 5)
317		return ret;
318	last_check = now;
319	ret = (fs_proc_check("ext4dev") || check_for_modules("ext4dev"));
320	return ret;
321}
322
323static int probe_ext4dev(struct blkid_probe *probe,
324			 struct blkid_magic *id,
325			 unsigned char *buf)
326{
327	struct ext2_super_block *es;
328	es = (struct ext2_super_block *)buf;
329
330	/* Distinguish from jbd */
331	if (blkid_le32(es->s_feature_incompat) &
332	    EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
333		return -BLKID_ERR_PARAM;
334
335	/*
336	 * If the filesystem does not have a journal and ext2 and ext4
337	 * is not present, then force this to be detected as an
338	 * ext4dev filesystem.
339	 */
340	if (!(blkid_le32(es->s_feature_compat) &
341	      EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
342	    !system_supports_ext2() && !system_supports_ext4() &&
343	    system_supports_ext4dev() &&
344	    linux_version_code() >= EXT4_SUPPORTS_EXT2)
345		goto force_ext4dev;
346
347	/*
348	 * If the filesystem is marked as OK for use by in-development
349	 * filesystem code, but ext4dev is not supported, and ext4 is,
350	 * then don't call ourselves ext4dev, since we should be
351	 * detected as ext4 in that case.
352	 *
353	 * If the filesystem is marked as in use by production
354	 * filesystem, then it can only be used by ext4 and NOT by
355	 * ext4dev, so always disclaim we are ext4dev in that case.
356	 */
357	if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) {
358		if (!system_supports_ext4dev() && system_supports_ext4())
359			return -BLKID_ERR_PARAM;
360	} else
361		return -BLKID_ERR_PARAM;
362
363force_ext4dev:
364    	get_ext2_info(probe->dev, id, buf);
365	return 0;
366}
367
368static int probe_ext4(struct blkid_probe *probe, struct blkid_magic *id,
369		      unsigned char *buf)
370{
371	struct ext2_super_block *es;
372	es = (struct ext2_super_block *)buf;
373
374	/* Distinguish from jbd */
375	if (blkid_le32(es->s_feature_incompat) &
376	    EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
377		return -BLKID_ERR_PARAM;
378
379	/*
380	 * If the filesystem does not have a journal and ext2 is not
381	 * present, then force this to be detected as an ext2
382	 * filesystem.
383	 */
384	if (!(blkid_le32(es->s_feature_compat) &
385	      EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
386	    !system_supports_ext2() && system_supports_ext4() &&
387	    linux_version_code() >= EXT4_SUPPORTS_EXT2)
388		goto force_ext4;
389
390	/* Ext4 has at least one feature which ext3 doesn't understand */
391	if (!(blkid_le32(es->s_feature_ro_compat) &
392	      EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) &&
393	    !(blkid_le32(es->s_feature_incompat) &
394	      EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
395		return -BLKID_ERR_PARAM;
396
397force_ext4:
398	/*
399	 * If the filesystem is a OK for use by in-development
400	 * filesystem code, and ext4dev is supported or ext4 is not
401	 * supported, then don't call ourselves ext4, so we can redo
402	 * the detection and mark the filesystem as ext4dev.
403	 *
404	 * If the filesystem is marked as in use by production
405	 * filesystem, then it can only be used by ext4 and NOT by
406	 * ext4dev.
407	 */
408	if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) {
409		if (system_supports_ext4dev() || !system_supports_ext4())
410			return -BLKID_ERR_PARAM;
411	}
412    	get_ext2_info(probe->dev, id, buf);
413	return 0;
414}
415
416static int probe_ext3(struct blkid_probe *probe, struct blkid_magic *id,
417		      unsigned char *buf)
418{
419	struct ext2_super_block *es;
420	es = (struct ext2_super_block *)buf;
421
422	/* ext3 requires journal */
423	if (!(blkid_le32(es->s_feature_compat) &
424	      EXT3_FEATURE_COMPAT_HAS_JOURNAL))
425		return -BLKID_ERR_PARAM;
426
427	/* Any features which ext3 doesn't understand */
428	if ((blkid_le32(es->s_feature_ro_compat) &
429	     EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) ||
430	    (blkid_le32(es->s_feature_incompat) &
431	     EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
432		return -BLKID_ERR_PARAM;
433
434    	get_ext2_info(probe->dev, id, buf);
435	return 0;
436}
437
438static int probe_ext2(struct blkid_probe *probe, struct blkid_magic *id,
439		      unsigned char *buf)
440{
441	struct ext2_super_block *es;
442
443	es = (struct ext2_super_block *)buf;
444
445	/* Distinguish between ext3 and ext2 */
446	if ((blkid_le32(es->s_feature_compat) &
447	      EXT3_FEATURE_COMPAT_HAS_JOURNAL))
448		return -BLKID_ERR_PARAM;
449
450	/* Any features which ext2 doesn't understand */
451	if ((blkid_le32(es->s_feature_ro_compat) &
452	     EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) ||
453	    (blkid_le32(es->s_feature_incompat) &
454	     EXT2_FEATURE_INCOMPAT_UNSUPPORTED))
455		return -BLKID_ERR_PARAM;
456
457	/*
458	 * If ext2 is not present, but ext4 or ext4dev are, then
459	 * disclaim we are ext2
460	 */
461	if (!system_supports_ext2() &&
462	    (system_supports_ext4() || system_supports_ext4dev()) &&
463	    linux_version_code() >= EXT4_SUPPORTS_EXT2)
464		return -BLKID_ERR_PARAM;
465
466	get_ext2_info(probe->dev, id, buf);
467	return 0;
468}
469
470static int probe_jbd(struct blkid_probe *probe, struct blkid_magic *id,
471		     unsigned char *buf)
472{
473	struct ext2_super_block *es = (struct ext2_super_block *) buf;
474
475	if (!(blkid_le32(es->s_feature_incompat) &
476	      EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
477		return -BLKID_ERR_PARAM;
478
479	get_ext2_info(probe->dev, id, buf);
480
481	return 0;
482}
483
484#define FAT_ATTR_VOLUME_ID		0x08
485#define FAT_ATTR_DIR			0x10
486#define FAT_ATTR_LONG_NAME		0x0f
487#define FAT_ATTR_MASK			0x3f
488#define FAT_ENTRY_FREE			0xe5
489
490static const char *no_name = "NO NAME    ";
491
492static unsigned char *search_fat_label(struct vfat_dir_entry *dir, int count)
493{
494	int i;
495
496	for (i = 0; i < count; i++) {
497		if (dir[i].name[0] == 0x00)
498			break;
499
500		if ((dir[i].name[0] == FAT_ENTRY_FREE) ||
501		    (dir[i].cluster_high != 0 || dir[i].cluster_low != 0) ||
502		    ((dir[i].attr & FAT_ATTR_MASK) == FAT_ATTR_LONG_NAME))
503			continue;
504
505		if ((dir[i].attr & (FAT_ATTR_VOLUME_ID | FAT_ATTR_DIR)) ==
506		    FAT_ATTR_VOLUME_ID) {
507			return dir[i].name;
508		}
509	}
510	return 0;
511}
512
513/* FAT label extraction from the root directory taken from Kay
514 * Sievers's volume_id library */
515static int probe_fat(struct blkid_probe *probe,
516		      struct blkid_magic *id __BLKID_ATTR((unused)),
517		      unsigned char *buf)
518{
519	struct vfat_super_block *vs = (struct vfat_super_block *) buf;
520	struct msdos_super_block *ms = (struct msdos_super_block *) buf;
521	struct vfat_dir_entry *dir;
522	char serno[10];
523	const unsigned char *label = 0, *vol_label = 0, *tmp;
524	unsigned char	*vol_serno;
525	int label_len = 0, maxloop = 100;
526	__u16 sector_size, dir_entries, reserved;
527	__u32 sect_count, fat_size, dir_size, cluster_count, fat_length;
528	__u32 buf_size, start_data_sect, next, root_start, root_dir_entries;
529
530	/* sector size check */
531	tmp = (unsigned char *)&ms->ms_sector_size;
532	sector_size = tmp[0] + (tmp[1] << 8);
533	if (sector_size != 0x200 && sector_size != 0x400 &&
534	    sector_size != 0x800 && sector_size != 0x1000)
535		return 1;
536
537	tmp = (unsigned char *)&ms->ms_dir_entries;
538	dir_entries = tmp[0] + (tmp[1] << 8);
539	reserved =  blkid_le16(ms->ms_reserved);
540	tmp = (unsigned char *)&ms->ms_sectors;
541	sect_count = tmp[0] + (tmp[1] << 8);
542	if (sect_count == 0)
543		sect_count = blkid_le32(ms->ms_total_sect);
544
545	fat_length = blkid_le16(ms->ms_fat_length);
546	if (fat_length == 0)
547		fat_length = blkid_le32(vs->vs_fat32_length);
548
549	fat_size = fat_length * ms->ms_fats;
550	dir_size = ((dir_entries * sizeof(struct vfat_dir_entry)) +
551			(sector_size-1)) / sector_size;
552
553	cluster_count = sect_count - (reserved + fat_size + dir_size);
554	if (ms->ms_cluster_size == 0)
555		return 1;
556	cluster_count /= ms->ms_cluster_size;
557
558	if (cluster_count > FAT32_MAX)
559		return 1;
560
561	if (ms->ms_fat_length) {
562		/* the label may be an attribute in the root directory */
563		root_start = (reserved + fat_size) * sector_size;
564		root_dir_entries = vs->vs_dir_entries[0] +
565			(vs->vs_dir_entries[1] << 8);
566
567		buf_size = root_dir_entries * sizeof(struct vfat_dir_entry);
568		dir = (struct vfat_dir_entry *) get_buffer(probe, root_start,
569							   buf_size);
570		if (dir)
571			vol_label = search_fat_label(dir, root_dir_entries);
572
573		if (!vol_label || !memcmp(vol_label, no_name, 11))
574			vol_label = ms->ms_label;
575		vol_serno = ms->ms_serno;
576
577		blkid_set_tag(probe->dev, "SEC_TYPE", "msdos",
578			      sizeof("msdos"));
579	} else {
580		/* Search the FAT32 root dir for the label attribute */
581		buf_size = vs->vs_cluster_size * sector_size;
582		start_data_sect = reserved + fat_size;
583
584		next = blkid_le32(vs->vs_root_cluster);
585		while (next && --maxloop) {
586			__u32 next_sect_off;
587			__u64 next_off, fat_entry_off;
588			int count;
589
590			next_sect_off = (next - 2) * vs->vs_cluster_size;
591			next_off = (start_data_sect + next_sect_off) *
592				sector_size;
593
594			dir = (struct vfat_dir_entry *)
595				get_buffer(probe, next_off, buf_size);
596			if (dir == NULL)
597				break;
598
599			count = buf_size / sizeof(struct vfat_dir_entry);
600
601			vol_label = search_fat_label(dir, count);
602			if (vol_label)
603				break;
604
605			/* get FAT entry */
606			fat_entry_off = (reserved * sector_size) +
607				(next * sizeof(__u32));
608			buf = get_buffer(probe, fat_entry_off, buf_size);
609			if (buf == NULL)
610				break;
611
612			/* set next cluster */
613			next = blkid_le32(*((__u32 *) buf) & 0x0fffffff);
614		}
615
616		if (!vol_label || !memcmp(vol_label, no_name, 11))
617			vol_label = vs->vs_label;
618		vol_serno = vs->vs_serno;
619	}
620
621	if (vol_label && memcmp(vol_label, no_name, 11)) {
622		if ((label_len = figure_label_len(vol_label, 11)))
623			label = vol_label;
624	}
625
626	/* We can't just print them as %04X, because they are unaligned */
627	sprintf(serno, "%02X%02X-%02X%02X", vol_serno[3], vol_serno[2],
628		vol_serno[1], vol_serno[0]);
629
630	blkid_set_tag(probe->dev, "LABEL", (const char *) label, label_len);
631	blkid_set_tag(probe->dev, "UUID", serno, sizeof(serno)-1);
632
633	return 0;
634}
635
636/*
637 * The FAT filesystem could be without a magic string in superblock
638 * (e.g. old floppies).  This heuristic for FAT detection is inspired
639 * by http://vrfy.org/projects/volume_id/ and Linux kernel.
640 * [7-Jul-2005, Karel Zak <kzak@redhat.com>]
641 */
642static int probe_fat_nomagic(struct blkid_probe *probe,
643			     struct blkid_magic *id __BLKID_ATTR((unused)),
644			     unsigned char *buf)
645{
646	struct msdos_super_block *ms;
647
648	ms = (struct msdos_super_block *)buf;
649
650	/* heads check */
651	if (ms->ms_heads == 0)
652		return 1;
653
654	/* cluster size check*/
655	if (ms->ms_cluster_size == 0 ||
656	    (ms->ms_cluster_size & (ms->ms_cluster_size-1)))
657		return 1;
658
659	/* media check */
660	if (ms->ms_media < 0xf8 && ms->ms_media != 0xf0)
661		return 1;
662
663	/* fat counts(Linux kernel expects at least 1 FAT table) */
664	if (!ms->ms_fats)
665		return 1;
666
667	/*
668	 * OS/2 and apparently DFSee will place a FAT12/16-like
669	 * pseudo-superblock in the first 512 bytes of non-FAT
670	 * filesystems --- at least JFS and HPFS, and possibly others.
671	 * So we explicitly check for those filesystems at the
672	 * FAT12/16 filesystem magic field identifier, and if they are
673	 * present, we rule this out as a FAT filesystem, despite the
674	 * FAT-like pseudo-header.
675         */
676	if ((memcmp(ms->ms_magic, "JFS     ", 8) == 0) ||
677	    (memcmp(ms->ms_magic, "HPFS    ", 8) == 0))
678		return 1;
679
680	return probe_fat(probe, id, buf);
681}
682
683static int probe_ntfs(struct blkid_probe *probe,
684		      struct blkid_magic *id __BLKID_ATTR((unused)),
685		      unsigned char *buf)
686{
687	struct ntfs_super_block *ns;
688	struct master_file_table_record *mft;
689	struct file_attribute *attr;
690	char		uuid_str[17], label_str[129], *cp;
691	int		bytes_per_sector, sectors_per_cluster;
692	int		mft_record_size, attr_off, attr_len;
693	unsigned int	i, attr_type, val_len;
694	int		val_off;
695	__u64		nr_clusters;
696	blkid_loff_t off;
697	unsigned char *buf_mft, *val;
698
699	ns = (struct ntfs_super_block *) buf;
700
701	bytes_per_sector = ns->bios_parameter_block[0] +
702		(ns->bios_parameter_block[1]  << 8);
703	sectors_per_cluster = ns->bios_parameter_block[2];
704
705	if ((bytes_per_sector < 512) || (sectors_per_cluster == 0))
706		return 1;
707
708	if (ns->cluster_per_mft_record < 0)
709		mft_record_size = 1 << (0-ns->cluster_per_mft_record);
710	else
711		mft_record_size = ns->cluster_per_mft_record *
712			sectors_per_cluster * bytes_per_sector;
713	nr_clusters = blkid_le64(ns->number_of_sectors) / sectors_per_cluster;
714
715	if ((blkid_le64(ns->mft_cluster_location) > nr_clusters) ||
716	    (blkid_le64(ns->mft_mirror_cluster_location) > nr_clusters))
717		return 1;
718
719	off = blkid_le64(ns->mft_mirror_cluster_location) *
720		bytes_per_sector * sectors_per_cluster;
721
722	buf_mft = get_buffer(probe, off, mft_record_size);
723	if (!buf_mft)
724		return 1;
725
726	if (memcmp(buf_mft, "FILE", 4))
727		return 1;
728
729	off = blkid_le64(ns->mft_cluster_location) * bytes_per_sector *
730		sectors_per_cluster;
731
732	buf_mft = get_buffer(probe, off, mft_record_size);
733	if (!buf_mft)
734		return 1;
735
736	if (memcmp(buf_mft, "FILE", 4))
737		return 1;
738
739	off += MFT_RECORD_VOLUME * mft_record_size;
740
741	buf_mft = get_buffer(probe, off, mft_record_size);
742	if (!buf_mft)
743		return 1;
744
745	if (memcmp(buf_mft, "FILE", 4))
746		return 1;
747
748	mft = (struct master_file_table_record *) buf_mft;
749
750	attr_off = blkid_le16(mft->attrs_offset);
751	label_str[0] = 0;
752
753	while (1) {
754		attr = (struct file_attribute *) (buf_mft + attr_off);
755		attr_len = blkid_le16(attr->len);
756		attr_type = blkid_le32(attr->type);
757		val_off = blkid_le16(attr->value_offset);
758		val_len = blkid_le32(attr->value_len);
759
760		attr_off += attr_len;
761
762		if ((attr_off > mft_record_size) ||
763		    (attr_len == 0))
764			break;
765
766		if (attr_type == MFT_RECORD_ATTR_END)
767			break;
768
769		if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
770			if (val_len > sizeof(label_str))
771				val_len = sizeof(label_str)-1;
772
773			for (i=0, cp=label_str; i < val_len; i+=2,cp++) {
774				val = ((__u8 *) attr) + val_off + i;
775				*cp = val[0];
776				if (val[1])
777					*cp = '?';
778			}
779			*cp = 0;
780		}
781	}
782
783	sprintf(uuid_str, "%016llX", blkid_le64(ns->volume_serial));
784	blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
785	if (label_str[0])
786		blkid_set_tag(probe->dev, "LABEL", label_str, 0);
787	return 0;
788}
789
790
791static int probe_xfs(struct blkid_probe *probe,
792		     struct blkid_magic *id __BLKID_ATTR((unused)),
793		     unsigned char *buf)
794{
795	struct xfs_super_block *xs;
796	const char *label = 0;
797
798	xs = (struct xfs_super_block *)buf;
799
800	if (strlen(xs->xs_fname))
801		label = xs->xs_fname;
802	blkid_set_tag(probe->dev, "LABEL", label, sizeof(xs->xs_fname));
803	set_uuid(probe->dev, xs->xs_uuid, 0);
804	return 0;
805}
806
807static int probe_reiserfs(struct blkid_probe *probe,
808			  struct blkid_magic *id, unsigned char *buf)
809{
810	struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
811	unsigned int blocksize;
812	const char *label = 0;
813
814	blocksize = blkid_le16(rs->rs_blocksize);
815
816	/* The blocksize must be at least 1k */
817	if ((blocksize >> 10) == 0)
818		return -BLKID_ERR_PARAM;
819
820	/* If the superblock is inside the journal, we have the wrong one */
821	if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
822		return -BLKID_ERR_BIG;
823
824	/* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
825	if (id->bim_magic[6] == '2' || id->bim_magic[6] == '3') {
826		if (strlen(rs->rs_label))
827			label = rs->rs_label;
828		set_uuid(probe->dev, rs->rs_uuid, 0);
829	}
830	blkid_set_tag(probe->dev, "LABEL", label, sizeof(rs->rs_label));
831
832	return 0;
833}
834
835static int probe_reiserfs4(struct blkid_probe *probe,
836			   struct blkid_magic *id __BLKID_ATTR((unused)),
837			   unsigned char *buf)
838{
839	struct reiser4_super_block *rs4 = (struct reiser4_super_block *) buf;
840	const unsigned char *label = 0;
841
842	if (strlen((char *) rs4->rs4_label))
843		label = rs4->rs4_label;
844	set_uuid(probe->dev, rs4->rs4_uuid, 0);
845	blkid_set_tag(probe->dev, "LABEL", (const char *) label,
846		      sizeof(rs4->rs4_label));
847
848	return 0;
849}
850
851static int probe_jfs(struct blkid_probe *probe,
852		     struct blkid_magic *id __BLKID_ATTR((unused)),
853		     unsigned char *buf)
854{
855	struct jfs_super_block *js;
856	const char *label = 0;
857
858	js = (struct jfs_super_block *)buf;
859
860	if (blkid_le32(js->js_bsize) != (1 << blkid_le16(js->js_l2bsize)))
861		return 1;
862
863	if (blkid_le32(js->js_pbsize) != (1 << blkid_le16(js->js_l2pbsize)))
864		return 1;
865
866	if ((blkid_le16(js->js_l2bsize) - blkid_le16(js->js_l2pbsize)) !=
867	    blkid_le16(js->js_l2bfactor))
868		return 1;
869
870	if (strlen((char *) js->js_label))
871		label = (char *) js->js_label;
872	blkid_set_tag(probe->dev, "LABEL", label, sizeof(js->js_label));
873	set_uuid(probe->dev, js->js_uuid, 0);
874	return 0;
875}
876
877static int probe_zfs(struct blkid_probe *probe, struct blkid_magic *id,
878		     unsigned char *buf)
879{
880#if 0
881	char *vdev_label;
882	const char *pool_name = 0;
883
884	/* read nvpair data for pool name, pool GUID (complex) */
885	blkid_set_tag(probe->dev, "LABEL", pool_name, sizeof(pool_name));
886	set_uuid(probe->dev, pool_guid, 0);
887#endif
888	return 0;
889}
890
891static int probe_luks(struct blkid_probe *probe,
892		       struct blkid_magic *id __BLKID_ATTR((unused)),
893		       unsigned char *buf)
894{
895	char uuid[40];
896
897	/* 168 is the offset to the 40 character uuid:
898	 * http://luks.endorphin.org/LUKS-on-disk-format.pdf */
899	strncpy(uuid, (char *) buf+168, 40);
900	blkid_set_tag(probe->dev, "UUID", uuid, sizeof(uuid));
901	return 0;
902}
903
904static int probe_romfs(struct blkid_probe *probe,
905		       struct blkid_magic *id __BLKID_ATTR((unused)),
906		       unsigned char *buf)
907{
908	struct romfs_super_block *ros;
909	const char *label = 0;
910
911	ros = (struct romfs_super_block *)buf;
912
913	if (strlen((char *) ros->ros_volume))
914		label = (char *) ros->ros_volume;
915	blkid_set_tag(probe->dev, "LABEL", label, 0);
916	return 0;
917}
918
919static int probe_cramfs(struct blkid_probe *probe,
920			struct blkid_magic *id __BLKID_ATTR((unused)),
921			unsigned char *buf)
922{
923	struct cramfs_super_block *csb;
924	const char *label = 0;
925
926	csb = (struct cramfs_super_block *)buf;
927
928	if (strlen((char *) csb->name))
929		label = (char *) csb->name;
930	blkid_set_tag(probe->dev, "LABEL", label, 0);
931	return 0;
932}
933
934static int probe_swap0(struct blkid_probe *probe,
935		       struct blkid_magic *id __BLKID_ATTR((unused)),
936		       unsigned char *buf __BLKID_ATTR((unused)))
937{
938	blkid_set_tag(probe->dev, "UUID", 0, 0);
939	blkid_set_tag(probe->dev, "LABEL", 0, 0);
940	return 0;
941}
942
943static int probe_swap1(struct blkid_probe *probe,
944		       struct blkid_magic *id,
945		       unsigned char *buf __BLKID_ATTR((unused)))
946{
947	struct swap_id_block *sws;
948
949	probe_swap0(probe, id, buf);
950	/*
951	 * Version 1 swap headers are always located at offset of 1024
952	 * bytes, although the swap signature itself is located at the
953	 * end of the page (which may vary depending on hardware
954	 * pagesize).
955	 */
956	sws = (struct swap_id_block *) get_buffer(probe, 1024, 1024);
957	if (!sws)
958		return 1;
959
960	/* check for wrong version or zeroed pagecount, for sanity */
961	if (!memcmp(id->bim_magic, "SWAPSPACE2", id->bim_len) &&
962			(sws->sws_version != 1 || sws->sws_lastpage == 0))
963		return 1;
964
965	/* arbitrary sanity check.. is there any garbage down there? */
966	if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0)  {
967		if (sws->sws_volume[0])
968			blkid_set_tag(probe->dev, "LABEL", sws->sws_volume,
969				      sizeof(sws->sws_volume));
970		if (sws->sws_uuid[0])
971			set_uuid(probe->dev, sws->sws_uuid, 0);
972	}
973	return 0;
974}
975
976static int probe_iso9660(struct blkid_probe *probe,
977			 struct blkid_magic *id __BLKID_ATTR((unused)),
978			 unsigned char *buf)
979{
980	struct iso_volume_descriptor *iso;
981	const unsigned char *label;
982
983	iso = (struct iso_volume_descriptor *) buf;
984	label = iso->volume_id;
985
986	blkid_set_tag(probe->dev, "LABEL", (const char *) label,
987		      figure_label_len(label, 32));
988	return 0;
989}
990
991
992static const char
993*udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
994		 "NSR03", "TEA01", 0 };
995
996static int probe_udf(struct blkid_probe *probe,
997		     struct blkid_magic *id __BLKID_ATTR((unused)),
998		     unsigned char *buf __BLKID_ATTR((unused)))
999{
1000	int j, bs;
1001	struct iso_volume_descriptor *isosb;
1002	const char ** m;
1003
1004	/* determine the block size by scanning in 2K increments
1005	   (block sizes larger than 2K will be null padded) */
1006	for (bs = 1; bs < 16; bs++) {
1007		isosb = (struct iso_volume_descriptor *)
1008			get_buffer(probe, bs*2048+32768, sizeof(isosb));
1009		if (!isosb)
1010			return 1;
1011		if (isosb->vd_id[0])
1012			break;
1013	}
1014
1015	/* Scan up to another 64 blocks looking for additional VSD's */
1016	for (j = 1; j < 64; j++) {
1017		if (j > 1) {
1018			isosb = (struct iso_volume_descriptor *)
1019				get_buffer(probe, j*bs*2048+32768,
1020					   sizeof(isosb));
1021			if (!isosb)
1022				return 1;
1023		}
1024		/* If we find NSR0x then call it udf:
1025		   NSR01 for UDF 1.00
1026		   NSR02 for UDF 1.50
1027		   NSR03 for UDF 2.00 */
1028		if (!memcmp(isosb->vd_id, "NSR0", 4))
1029			return probe_iso9660(probe, id, buf);
1030		for (m = udf_magic; *m; m++)
1031			if (!memcmp(*m, isosb->vd_id, 5))
1032				break;
1033		if (*m == 0)
1034			return 1;
1035	}
1036	return 1;
1037}
1038
1039static int probe_ocfs(struct blkid_probe *probe,
1040		      struct blkid_magic *id __BLKID_ATTR((unused)),
1041		      unsigned char *buf)
1042{
1043	struct ocfs_volume_header ovh;
1044	struct ocfs_volume_label ovl;
1045	__u32 major;
1046
1047	memcpy(&ovh, buf, sizeof(ovh));
1048	memcpy(&ovl, buf+512, sizeof(ovl));
1049
1050	major = ocfsmajor(ovh);
1051	if (major == 1)
1052		blkid_set_tag(probe->dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
1053	else if (major >= 9)
1054		blkid_set_tag(probe->dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
1055
1056	blkid_set_tag(probe->dev, "LABEL", ovl.label, ocfslabellen(ovl));
1057	blkid_set_tag(probe->dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
1058	set_uuid(probe->dev, ovl.vol_id, 0);
1059	return 0;
1060}
1061
1062static int probe_ocfs2(struct blkid_probe *probe,
1063		       struct blkid_magic *id __BLKID_ATTR((unused)),
1064		       unsigned char *buf)
1065{
1066	struct ocfs2_super_block *osb;
1067
1068	osb = (struct ocfs2_super_block *)buf;
1069
1070	blkid_set_tag(probe->dev, "LABEL", osb->s_label, sizeof(osb->s_label));
1071	set_uuid(probe->dev, osb->s_uuid, 0);
1072	return 0;
1073}
1074
1075static int probe_oracleasm(struct blkid_probe *probe,
1076			   struct blkid_magic *id __BLKID_ATTR((unused)),
1077			   unsigned char *buf)
1078{
1079	struct oracle_asm_disk_label *dl;
1080
1081	dl = (struct oracle_asm_disk_label *)buf;
1082
1083	blkid_set_tag(probe->dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
1084	return 0;
1085}
1086
1087static int probe_gfs(struct blkid_probe *probe,
1088		     struct blkid_magic *id __BLKID_ATTR((unused)),
1089		     unsigned char *buf)
1090{
1091	struct gfs2_sb *sbd;
1092	const char *label = 0;
1093
1094	sbd = (struct gfs2_sb *)buf;
1095
1096	if (blkid_be32(sbd->sb_fs_format) == GFS_FORMAT_FS &&
1097	    blkid_be32(sbd->sb_multihost_format) == GFS_FORMAT_MULTI)
1098	{
1099		blkid_set_tag(probe->dev, "UUID", 0, 0);
1100
1101		if (strlen(sbd->sb_locktable))
1102			label = sbd->sb_locktable;
1103		blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
1104		return 0;
1105	}
1106	return 1;
1107}
1108
1109static int probe_gfs2(struct blkid_probe *probe,
1110		     struct blkid_magic *id __BLKID_ATTR((unused)),
1111		     unsigned char *buf)
1112{
1113	struct gfs2_sb *sbd;
1114	const char *label = 0;
1115
1116	sbd = (struct gfs2_sb *)buf;
1117
1118	if (blkid_be32(sbd->sb_fs_format) == GFS2_FORMAT_FS &&
1119	    blkid_be32(sbd->sb_multihost_format) == GFS2_FORMAT_MULTI)
1120	{
1121		blkid_set_tag(probe->dev, "UUID", 0, 0);
1122
1123		if (strlen(sbd->sb_locktable))
1124			label = sbd->sb_locktable;
1125		blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
1126		return 0;
1127	}
1128	return 1;
1129}
1130
1131static void unicode_16be_to_utf8(unsigned char *str, int out_len,
1132				 const unsigned char *buf, int in_len)
1133{
1134	int i, j;
1135	unsigned int c;
1136
1137	for (i = j = 0; i + 2 <= in_len; i += 2) {
1138		c = (buf[i] << 8) | buf[i+1];
1139		if (c == 0) {
1140			str[j] = '\0';
1141			break;
1142		} else if (c < 0x80) {
1143			if (j+1 >= out_len)
1144				break;
1145			str[j++] = (unsigned char) c;
1146		} else if (c < 0x800) {
1147			if (j+2 >= out_len)
1148				break;
1149			str[j++] = (unsigned char) (0xc0 | (c >> 6));
1150			str[j++] = (unsigned char) (0x80 | (c & 0x3f));
1151		} else {
1152			if (j+3 >= out_len)
1153				break;
1154			str[j++] = (unsigned char) (0xe0 | (c >> 12));
1155			str[j++] = (unsigned char) (0x80 | ((c >> 6) & 0x3f));
1156			str[j++] = (unsigned char) (0x80 | (c & 0x3f));
1157		}
1158	}
1159	str[j] = '\0';
1160}
1161
1162static int probe_hfs(struct blkid_probe *probe __BLKID_ATTR((unused)),
1163			 struct blkid_magic *id __BLKID_ATTR((unused)),
1164			 unsigned char *buf)
1165{
1166	struct hfs_mdb *hfs = (struct hfs_mdb *) buf;
1167	char	uuid_str[17];
1168	__u64	uuid;
1169
1170	if ((memcmp(hfs->embed_sig, "H+", 2) == 0) ||
1171	    (memcmp(hfs->embed_sig, "HX", 2) == 0))
1172		return 1;	/* Not hfs, but an embedded HFS+ */
1173
1174	uuid = blkid_le64(*((unsigned long long *) hfs->finder_info.id));
1175	if (uuid) {
1176		sprintf(uuid_str, "%016llX", uuid);
1177		blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
1178	}
1179	blkid_set_tag(probe->dev, "LABEL", hfs->label, hfs->label_len);
1180	return 0;
1181}
1182
1183
1184static int probe_hfsplus(struct blkid_probe *probe,
1185			 struct blkid_magic *id,
1186			 unsigned char *buf)
1187{
1188	struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
1189	struct hfsplus_bnode_descriptor *descr;
1190	struct hfsplus_bheader_record *bnode;
1191	struct hfsplus_catalog_key *key;
1192	struct hfsplus_vol_header *hfsplus;
1193	struct hfs_mdb *sbd = (struct hfs_mdb *) buf;
1194	unsigned int alloc_block_size;
1195	unsigned int alloc_first_block;
1196	unsigned int embed_first_block;
1197	unsigned int off = 0;
1198	unsigned int blocksize;
1199	unsigned int cat_block;
1200	unsigned int ext_block_start;
1201	unsigned int ext_block_count;
1202	unsigned int record_count;
1203	unsigned int leaf_node_head;
1204	unsigned int leaf_node_count;
1205	unsigned int leaf_node_size;
1206	unsigned int leaf_block;
1207	unsigned int label_len;
1208	int ext;
1209	__u64 leaf_off, uuid;
1210	char	uuid_str[17], label[512];
1211
1212	/* Check for a HFS+ volume embedded in a HFS volume */
1213	if (memcmp(sbd->signature, "BD", 2) == 0) {
1214		if ((memcmp(sbd->embed_sig, "H+", 2) != 0) &&
1215		    (memcmp(sbd->embed_sig, "HX", 2) != 0))
1216			/* This must be an HFS volume, so fail */
1217			return 1;
1218
1219		alloc_block_size = blkid_be32(sbd->al_blk_size);
1220		alloc_first_block = blkid_be16(sbd->al_bl_st);
1221		embed_first_block = blkid_be16(sbd->embed_startblock);
1222		off = (alloc_first_block * 512) +
1223			(embed_first_block * alloc_block_size);
1224		buf = get_buffer(probe, off + (id->bim_kboff * 1024),
1225				 sizeof(sbd));
1226		if (!buf)
1227			return 1;
1228
1229		hfsplus = (struct hfsplus_vol_header *) buf;
1230	}
1231
1232	hfsplus = (struct hfsplus_vol_header *) buf;
1233
1234	if ((memcmp(hfsplus->signature, "H+", 2) != 0) &&
1235	    (memcmp(hfsplus->signature, "HX", 2) != 0))
1236		return 1;
1237
1238	uuid = blkid_le64(*((unsigned long long *) hfsplus->finder_info.id));
1239	if (uuid) {
1240		sprintf(uuid_str, "%016llX", uuid);
1241		blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
1242	}
1243
1244	blocksize = blkid_be32(hfsplus->blocksize);
1245	memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
1246	cat_block = blkid_be32(extents[0].start_block);
1247
1248	buf = get_buffer(probe, off + (cat_block * blocksize), 0x2000);
1249	if (!buf)
1250		return 0;
1251
1252	bnode = (struct hfsplus_bheader_record *)
1253		&buf[sizeof(struct hfsplus_bnode_descriptor)];
1254
1255	leaf_node_head = blkid_be32(bnode->leaf_head);
1256	leaf_node_size = blkid_be16(bnode->node_size);
1257	leaf_node_count = blkid_be32(bnode->leaf_count);
1258	if (leaf_node_count == 0)
1259		return 0;
1260
1261	leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
1262
1263	/* get physical location */
1264	for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
1265		ext_block_start = blkid_be32(extents[ext].start_block);
1266		ext_block_count = blkid_be32(extents[ext].block_count);
1267		if (ext_block_count == 0)
1268			return 0;
1269
1270		/* this is our extent */
1271		if (leaf_block < ext_block_count)
1272			break;
1273
1274		leaf_block -= ext_block_count;
1275	}
1276	if (ext == HFSPLUS_EXTENT_COUNT)
1277		return 0;
1278
1279	leaf_off = (ext_block_start + leaf_block) * blocksize;
1280
1281	buf = get_buffer(probe, off + leaf_off, leaf_node_size);
1282	if (!buf)
1283		return 0;
1284
1285	descr = (struct hfsplus_bnode_descriptor *) buf;
1286	record_count = blkid_be16(descr->num_recs);
1287	if (record_count == 0)
1288		return 0;
1289
1290	if (descr->type != HFS_NODE_LEAF)
1291		return 0;
1292
1293	key = (struct hfsplus_catalog_key *)
1294		&buf[sizeof(struct hfsplus_bnode_descriptor)];
1295
1296	if (blkid_be32(key->parent_id) != HFSPLUS_POR_CNID)
1297		return 0;
1298
1299	label_len = blkid_be16(key->unicode_len) * 2;
1300	unicode_16be_to_utf8(label, sizeof(label), key->unicode, label_len);
1301	blkid_set_tag(probe->dev, "LABEL", label, 0);
1302	return 0;
1303}
1304
1305#define LVM2_LABEL_SIZE 512
1306static unsigned int lvm2_calc_crc(const void *buf, unsigned int size)
1307{
1308	static const unsigned int crctab[] = {
1309		0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
1310		0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
1311		0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
1312		0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
1313	};
1314	unsigned int i, crc = 0xf597a6cf;
1315	const __u8 *data = (const __u8 *) buf;
1316
1317	for (i = 0; i < size; i++) {
1318		crc ^= *data++;
1319		crc = (crc >> 4) ^ crctab[crc & 0xf];
1320		crc = (crc >> 4) ^ crctab[crc & 0xf];
1321	}
1322	return crc;
1323}
1324
1325static int probe_lvm2(struct blkid_probe *probe,
1326			struct blkid_magic *id,
1327			unsigned char *buf)
1328{
1329	int sector = (id->bim_kboff) << 1;
1330	struct lvm2_pv_label_header *label= (struct lvm2_pv_label_header *)buf;
1331	char *p, *q, uuid[40];
1332	unsigned int i, b;
1333
1334	/* buf is at 0k or 1k offset; find label inside */
1335	if (memcmp(buf, "LABELONE", 8) == 0) {
1336		label = (struct lvm2_pv_label_header *)buf;
1337	} else if (memcmp(buf + 512, "LABELONE", 8) == 0) {
1338		label = (struct lvm2_pv_label_header *)(buf + 512);
1339		sector++;
1340	} else {
1341		return 1;
1342	}
1343
1344	if (blkid_le64(label->sector_xl) != (unsigned) sector) {
1345		DBG(DEBUG_PROBE,
1346		    printf("LVM2: label for sector %llu found at sector %d\n",
1347			   blkid_le64(label->sector_xl), sector));
1348		return 1;
1349	}
1350
1351	if (lvm2_calc_crc(&label->offset_xl, LVM2_LABEL_SIZE -
1352			  ((char *)&label->offset_xl - (char *)label)) !=
1353			blkid_le32(label->crc_xl)) {
1354		DBG(DEBUG_PROBE,
1355		    printf("LVM2: label checksum incorrect at sector %d\n",
1356			   sector));
1357		return 1;
1358	}
1359
1360	for (i=0, b=1, p=uuid, q= (char *) label->pv_uuid; i <= 32;
1361	     i++, b <<= 1) {
1362		if (b & 0x4444440)
1363			*p++ = '-';
1364		*p++ = *q++;
1365	}
1366
1367	blkid_set_tag(probe->dev, "UUID", uuid, LVM2_ID_LEN+6);
1368
1369	return 0;
1370}
1371
1372static int probe_btrfs(struct blkid_probe *probe,
1373			struct blkid_magic *id,
1374			unsigned char *buf)
1375{
1376	struct btrfs_super_block *bs;
1377	const char *label = 0;
1378
1379	bs = (struct btrfs_super_block *)buf;
1380
1381	if (strlen(bs->label))
1382		label = bs->label;
1383	blkid_set_tag(probe->dev, "LABEL", label, sizeof(bs->label));
1384	set_uuid(probe->dev, bs->fsid, 0);
1385	return 0;
1386}
1387/*
1388 * Various filesystem magics that we can check for.  Note that kboff and
1389 * sboff are in kilobytes and bytes respectively.  All magics are in
1390 * byte strings so we don't worry about endian issues.
1391 */
1392static struct blkid_magic type_array[] = {
1393/*  type     kboff   sboff len  magic			probe */
1394  { "oracleasm", 0,	32,  8, "ORCLDISK",		probe_oracleasm },
1395  { "ntfs",	 0,	 3,  8, "NTFS    ",		probe_ntfs },
1396  { "jbd",	 1,   0x38,  2, "\123\357",		probe_jbd },
1397  { "ext4dev",	 1,   0x38,  2, "\123\357",		probe_ext4dev },
1398  { "ext4",	 1,   0x38,  2, "\123\357",		probe_ext4 },
1399  { "ext3",	 1,   0x38,  2, "\123\357",		probe_ext3 },
1400  { "ext2",	 1,   0x38,  2, "\123\357",		probe_ext2 },
1401  { "reiserfs",	 8,   0x34,  8, "ReIsErFs",		probe_reiserfs },
1402  { "reiserfs", 64,   0x34,  9, "ReIsEr2Fs",		probe_reiserfs },
1403  { "reiserfs", 64,   0x34,  9, "ReIsEr3Fs",		probe_reiserfs },
1404  { "reiserfs", 64,   0x34,  8, "ReIsErFs",		probe_reiserfs },
1405  { "reiserfs",	 8,	20,  8, "ReIsErFs",		probe_reiserfs },
1406  { "reiser4",  64,	 0,  7, "ReIsEr4",		probe_reiserfs4 },
1407  { "gfs2",     64,      0,  4, "\x01\x16\x19\x70",     probe_gfs2 },
1408  { "gfs",      64,      0,  4, "\x01\x16\x19\x70",     probe_gfs },
1409  { "vfat",      0,   0x52,  5, "MSWIN",                probe_fat },
1410  { "vfat",      0,   0x52,  8, "FAT32   ",             probe_fat },
1411  { "vfat",      0,   0x36,  5, "MSDOS",                probe_fat },
1412  { "vfat",      0,   0x36,  8, "FAT16   ",             probe_fat },
1413  { "vfat",      0,   0x36,  8, "FAT12   ",             probe_fat },
1414  { "vfat",      0,      0,  1, "\353",                 probe_fat_nomagic },
1415  { "vfat",      0,      0,  1, "\351",                 probe_fat_nomagic },
1416  { "vfat",      0,  0x1fe,  2, "\125\252",             probe_fat_nomagic },
1417  { "minix",     1,   0x10,  2, "\177\023",             0 },
1418  { "minix",     1,   0x10,  2, "\217\023",             0 },
1419  { "minix",	 1,   0x10,  2, "\150\044",		0 },
1420  { "minix",	 1,   0x10,  2, "\170\044",		0 },
1421  { "vxfs",	 1,	 0,  4, "\365\374\001\245",	0 },
1422  { "xfs",	 0,	 0,  4, "XFSB",			probe_xfs },
1423  { "romfs",	 0,	 0,  8, "-rom1fs-",		probe_romfs },
1424  { "bfs",	 0,	 0,  4, "\316\372\173\033",	0 },
1425  { "cramfs",	 0,	 0,  4, "E=\315\050",		probe_cramfs },
1426  { "qnx4",	 0,	 4,  6, "QNX4FS",		0 },
1427  { "udf",	32,	 1,  5, "BEA01",		probe_udf },
1428  { "udf",	32,	 1,  5, "BOOT2",		probe_udf },
1429  { "udf",	32,	 1,  5, "CD001",		probe_udf },
1430  { "udf",	32,	 1,  5, "CDW02",		probe_udf },
1431  { "udf",	32,	 1,  5, "NSR02",		probe_udf },
1432  { "udf",	32,	 1,  5, "NSR03",		probe_udf },
1433  { "udf",	32,	 1,  5, "TEA01",		probe_udf },
1434  { "iso9660",	32,	 1,  5, "CD001",		probe_iso9660 },
1435  { "iso9660",	32,	 9,  5, "CDROM",		probe_iso9660 },
1436  { "jfs",	32,	 0,  4, "JFS1",			probe_jfs },
1437  { "zfs",       8,	 0,  8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", probe_zfs },
1438  { "zfs",       8,	 0,  8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", probe_zfs },
1439  { "zfs",     264,	 0,  8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", probe_zfs },
1440  { "zfs",     264,	 0,  8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", probe_zfs },
1441  { "hfsplus",	 1,	 0,  2, "BD",			probe_hfsplus },
1442  { "hfsplus",	 1,	 0,  2, "H+",			probe_hfsplus },
1443  { "hfsplus",	 1,	 0,  2, "HX",			probe_hfsplus },
1444  { "hfs",	 1,	 0,  2, "BD",			probe_hfs },
1445  { "ufs",	 8,  0x55c,  4, "T\031\001\000",	0 },
1446  { "hpfs",	 8,	 0,  4, "I\350\225\371",	0 },
1447  { "sysv",	 0,  0x3f8,  4, "\020~\030\375",	0 },
1448  { "swap",	 0,  0xff6, 10, "SWAP-SPACE",		probe_swap0 },
1449  { "swap",	 0,  0xff6, 10, "SWAPSPACE2",		probe_swap1 },
1450  { "swsuspend", 0,  0xff6,  9, "S1SUSPEND",		probe_swap1 },
1451  { "swsuspend", 0,  0xff6,  9, "S2SUSPEND",		probe_swap1 },
1452  { "swsuspend", 0,  0xff6,  9, "ULSUSPEND",		probe_swap1 },
1453  { "swap",	 0, 0x1ff6, 10, "SWAP-SPACE",		probe_swap0 },
1454  { "swap",	 0, 0x1ff6, 10, "SWAPSPACE2",		probe_swap1 },
1455  { "swsuspend", 0, 0x1ff6,  9, "S1SUSPEND",		probe_swap1 },
1456  { "swsuspend", 0, 0x1ff6,  9, "S2SUSPEND",		probe_swap1 },
1457  { "swsuspend", 0, 0x1ff6,  9, "ULSUSPEND",		probe_swap1 },
1458  { "swap",	 0, 0x3ff6, 10, "SWAP-SPACE",		probe_swap0 },
1459  { "swap",	 0, 0x3ff6, 10, "SWAPSPACE2",		probe_swap1 },
1460  { "swsuspend", 0, 0x3ff6,  9, "S1SUSPEND",		probe_swap1 },
1461  { "swsuspend", 0, 0x3ff6,  9, "S2SUSPEND",		probe_swap1 },
1462  { "swsuspend", 0, 0x3ff6,  9, "ULSUSPEND",		probe_swap1 },
1463  { "swap",	 0, 0x7ff6, 10, "SWAP-SPACE",		probe_swap0 },
1464  { "swap",	 0, 0x7ff6, 10, "SWAPSPACE2",		probe_swap1 },
1465  { "swsuspend", 0, 0x7ff6,  9, "S1SUSPEND",		probe_swap1 },
1466  { "swsuspend", 0, 0x7ff6,  9, "S2SUSPEND",		probe_swap1 },
1467  { "swsuspend", 0, 0x7ff6,  9, "ULSUSPEND",		probe_swap1 },
1468  { "swap",	 0, 0xfff6, 10, "SWAP-SPACE",		probe_swap0 },
1469  { "swap",	 0, 0xfff6, 10, "SWAPSPACE2",		probe_swap1 },
1470  { "swsuspend", 0, 0xfff6,  9, "S1SUSPEND",		probe_swap1 },
1471  { "swsuspend", 0, 0xfff6,  9, "S2SUSPEND",		probe_swap1 },
1472  { "swsuspend", 0, 0xfff6,  9, "ULSUSPEND",		probe_swap1 },
1473  { "ocfs",	 0,	 8,  9,	"OracleCFS",		probe_ocfs },
1474  { "ocfs2",	 1,	 0,  6,	"OCFSV2",		probe_ocfs2 },
1475  { "ocfs2",	 2,	 0,  6,	"OCFSV2",		probe_ocfs2 },
1476  { "ocfs2",	 4,	 0,  6,	"OCFSV2",		probe_ocfs2 },
1477  { "ocfs2",	 8,	 0,  6,	"OCFSV2",		probe_ocfs2 },
1478  { "crypt_LUKS", 0,	 0,  6,	"LUKS\xba\xbe",		probe_luks },
1479  { "squashfs",	 0,	 0,  4,	"sqsh",			0 },
1480  { "squashfs",	 0,	 0,  4,	"hsqs",			0 },
1481  { "lvm2pv",	 0,  0x218,  8, "LVM2 001",		probe_lvm2 },
1482  { "lvm2pv",	 0,  0x018,  8, "LVM2 001",		probe_lvm2 },
1483  { "lvm2pv",	 1,  0x018,  8, "LVM2 001",		probe_lvm2 },
1484  { "lvm2pv",	 1,  0x218,  8, "LVM2 001",		probe_lvm2 },
1485  { "btrfs",	 64,  0x40,  8, "_BHRfS_M",		probe_btrfs },
1486  {   NULL,	 0,	 0,  0, NULL,			NULL }
1487};
1488
1489/*
1490 * Verify that the data in dev is consistent with what is on the actual
1491 * block device (using the devname field only).  Normally this will be
1492 * called when finding items in the cache, but for long running processes
1493 * is also desirable to revalidate an item before use.
1494 *
1495 * If we are unable to revalidate the data, we return the old data and
1496 * do not set the BLKID_BID_FL_VERIFIED flag on it.
1497 */
1498blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
1499{
1500	struct blkid_magic *id;
1501	struct blkid_probe probe;
1502	blkid_tag_iterate iter;
1503	unsigned char *buf;
1504	const char *type, *value;
1505	struct stat st;
1506	time_t diff, now;
1507	int idx;
1508
1509	if (!dev)
1510		return NULL;
1511
1512	now = time(0);
1513	diff = now - dev->bid_time;
1514
1515	if (stat(dev->bid_name, &st) < 0) {
1516		DBG(DEBUG_PROBE,
1517		    printf("blkid_verify: error %s (%d) while "
1518			   "trying to stat %s\n", strerror(errno), errno,
1519			   dev->bid_name));
1520	open_err:
1521		if ((errno == EPERM) || (errno == EACCES) || (errno == ENOENT)) {
1522			/* We don't have read permission, just return cache data. */
1523			DBG(DEBUG_PROBE, printf("returning unverified data for %s\n",
1524						dev->bid_name));
1525			return dev;
1526		}
1527		blkid_free_dev(dev);
1528		return NULL;
1529	}
1530
1531	if ((now >= dev->bid_time) &&
1532	    (st.st_mtime <= dev->bid_time) &&
1533	    ((diff < BLKID_PROBE_MIN) ||
1534	     (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
1535	      diff < BLKID_PROBE_INTERVAL)))
1536		return dev;
1537
1538	DBG(DEBUG_PROBE,
1539	    printf("need to revalidate %s (cache time %lu, stat time %lu,\n\t"
1540		   "time since last check %lu)\n",
1541		   dev->bid_name, (unsigned long)dev->bid_time,
1542		   (unsigned long)st.st_mtime, (unsigned long)diff));
1543
1544	if ((probe.fd = open(dev->bid_name, O_RDONLY)) < 0) {
1545		DBG(DEBUG_PROBE, printf("blkid_verify: error %s (%d) while "
1546					"opening %s\n", strerror(errno), errno,
1547					dev->bid_name));
1548		goto open_err;
1549	}
1550
1551	probe.cache = cache;
1552	probe.dev = dev;
1553	probe.sbbuf = 0;
1554	probe.buf = 0;
1555	probe.buf_max = 0;
1556
1557	/*
1558	 * Iterate over the type array.  If we already know the type,
1559	 * then try that first.  If it doesn't work, then blow away
1560	 * the type information, and try again.
1561	 *
1562	 */
1563try_again:
1564	type = 0;
1565	if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
1566		uuid_t	uuid;
1567
1568		if (check_mdraid(probe.fd, uuid) == 0) {
1569			set_uuid(dev, uuid, 0);
1570			type = "mdraid";
1571			goto found_type;
1572		}
1573	}
1574	for (id = type_array; id->bim_type; id++) {
1575		if (dev->bid_type &&
1576		    strcmp(id->bim_type, dev->bid_type))
1577			continue;
1578
1579		idx = id->bim_kboff + (id->bim_sboff >> 10);
1580		buf = get_buffer(&probe, idx << 10, 1024);
1581		if (!buf)
1582			continue;
1583
1584		if (memcmp(id->bim_magic, buf + (id->bim_sboff & 0x3ff),
1585			   id->bim_len))
1586			continue;
1587
1588		if ((id->bim_probe == NULL) ||
1589		    (id->bim_probe(&probe, id, buf) == 0)) {
1590			type = id->bim_type;
1591			goto found_type;
1592		}
1593	}
1594
1595	if (!id->bim_type && dev->bid_type) {
1596		/*
1597		 * Zap the device filesystem information and try again
1598		 */
1599		DBG(DEBUG_PROBE,
1600		    printf("previous fs type %s not valid, "
1601			   "trying full probe\n", dev->bid_type));
1602		iter = blkid_tag_iterate_begin(dev);
1603		while (blkid_tag_next(iter, &type, &value) == 0)
1604			blkid_set_tag(dev, type, 0, 0);
1605		blkid_tag_iterate_end(iter);
1606		goto try_again;
1607	}
1608
1609	if (!dev->bid_type) {
1610		blkid_free_dev(dev);
1611		dev = 0;
1612		goto found_type;
1613	}
1614
1615found_type:
1616	if (dev && type) {
1617		dev->bid_devno = st.st_rdev;
1618		dev->bid_time = time(0);
1619		dev->bid_flags |= BLKID_BID_FL_VERIFIED;
1620		cache->bic_flags |= BLKID_BIC_FL_CHANGED;
1621
1622		blkid_set_tag(dev, "TYPE", type, 0);
1623
1624		DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
1625			   dev->bid_name, (long long)st.st_rdev, type));
1626	}
1627
1628	free(probe.sbbuf);
1629	free(probe.buf);
1630	if (probe.fd >= 0)
1631		close(probe.fd);
1632
1633	return dev;
1634}
1635
1636int blkid_known_fstype(const char *fstype)
1637{
1638	struct blkid_magic *id;
1639
1640	for (id = type_array; id->bim_type; id++) {
1641		if (strcmp(fstype, id->bim_type) == 0)
1642			return 1;
1643	}
1644	return 0;
1645}
1646
1647#ifdef TEST_PROGRAM
1648int main(int argc, char **argv)
1649{
1650	blkid_dev dev;
1651	blkid_cache cache;
1652	int ret;
1653
1654	if (argc != 2) {
1655		fprintf(stderr, "Usage: %s device\n"
1656			"Probe a single device to determine type\n", argv[0]);
1657		exit(1);
1658	}
1659	if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
1660		fprintf(stderr, "%s: error creating cache (%d)\n",
1661			argv[0], ret);
1662		exit(1);
1663	}
1664	dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
1665	if (!dev) {
1666		printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
1667		return (1);
1668	}
1669	printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");
1670	if (dev->bid_label)
1671		printf("LABEL='%s'\n", dev->bid_label);
1672	if (dev->bid_uuid)
1673		printf("UUID='%s'\n", dev->bid_uuid);
1674
1675	blkid_free_dev(dev);
1676	return (0);
1677}
1678#endif
1679