probe.c revision 0a84e9cae698b8ea5c3389429126c25816986d81
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#include <sys/utsname.h>
30#ifdef HAVE_ERRNO_H
31#include <errno.h>
32#endif
33#include "blkidP.h"
34#include "uuid/uuid.h"
35#include "probe.h"
36
37static int figure_label_len(const unsigned char *label, int len)
38{
39	const unsigned char *end = label + len - 1;
40
41	while ((*end == ' ' || *end == 0) && end >= label)
42		--end;
43	if (end >= label) {
44		label = label;
45		return end - label + 1;
46	}
47	return 0;
48}
49
50static unsigned char *get_buffer(struct blkid_probe *pr,
51			  blkid_loff_t off, size_t len)
52{
53	ssize_t		ret_read;
54	unsigned char	*newbuf;
55
56	if (off + len <= SB_BUFFER_SIZE) {
57		if (!pr->sbbuf) {
58			pr->sbbuf = malloc(SB_BUFFER_SIZE);
59			if (!pr->sbbuf)
60				return NULL;
61			if (lseek(pr->fd, 0, SEEK_SET) < 0)
62				return NULL;
63			ret_read = read(pr->fd, pr->sbbuf, SB_BUFFER_SIZE);
64			if (ret_read < 0)
65				ret_read = 0;
66			pr->sb_valid = ret_read;
67		}
68		if (off+len > pr->sb_valid)
69			return NULL;
70		return pr->sbbuf + off;
71	} else {
72		if (len > pr->buf_max) {
73			newbuf = realloc(pr->buf, len);
74			if (newbuf == NULL)
75				return NULL;
76			pr->buf = newbuf;
77			pr->buf_max = len;
78		}
79		if (blkid_llseek(pr->fd, off, SEEK_SET) < 0)
80			return NULL;
81		ret_read = read(pr->fd, pr->buf, len);
82		if (ret_read != (ssize_t) len)
83			return NULL;
84		return pr->buf;
85	}
86}
87
88
89/*
90 * This is a special case code to check for an MDRAID device.  We do
91 * this special since it requires checking for a superblock at the end
92 * of the device.
93 */
94static int check_mdraid(int fd, unsigned char *ret_uuid)
95{
96	struct mdp_superblock_s *md;
97	blkid_loff_t		offset;
98	char			buf[4096];
99
100	if (fd < 0)
101		return -BLKID_ERR_PARAM;
102
103	offset = (blkid_get_dev_size(fd) & ~((blkid_loff_t)65535)) - 65536;
104
105	if (blkid_llseek(fd, offset, 0) < 0 ||
106	    read(fd, buf, 4096) != 4096)
107		return -BLKID_ERR_IO;
108
109	/* Check for magic number */
110	if (memcmp("\251+N\374", buf, 4) && memcmp("\374N+\251", buf, 4))
111		return -BLKID_ERR_PARAM;
112
113	if (!ret_uuid)
114		return 0;
115	*ret_uuid = 0;
116
117	/* The MD UUID is not contiguous in the superblock, make it so */
118	md = (struct mdp_superblock_s *)buf;
119	if (md->set_uuid0 || md->set_uuid1 || md->set_uuid2 || md->set_uuid3) {
120		memcpy(ret_uuid, &md->set_uuid0, 4);
121		memcpy(ret_uuid + 4, &md->set_uuid1, 12);
122	}
123	return 0;
124}
125
126static void set_uuid(blkid_dev dev, uuid_t uuid, const char *tag)
127{
128	char	str[37];
129
130	if (!uuid_is_null(uuid)) {
131		uuid_unparse(uuid, str);
132		blkid_set_tag(dev, tag ? tag : "UUID", str, sizeof(str));
133	}
134}
135
136static void get_ext2_info(blkid_dev dev, struct blkid_magic *id,
137			  unsigned char *buf)
138{
139	struct ext2_super_block *es = (struct ext2_super_block *) buf;
140	const char *label = 0;
141
142	DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",
143		   blkid_le32(es->s_feature_compat),
144		   blkid_le32(es->s_feature_incompat),
145		   blkid_le32(es->s_feature_ro_compat)));
146
147	if (strlen(es->s_volume_name))
148		label = es->s_volume_name;
149	blkid_set_tag(dev, "LABEL", label, sizeof(es->s_volume_name));
150
151	set_uuid(dev, es->s_uuid, 0);
152
153	if ((es->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
154	    !uuid_is_null(es->s_journal_uuid))
155		set_uuid(dev, es->s_journal_uuid, "EXT_JOURNAL");
156
157	if (strcmp(id->bim_type, "ext2") &&
158	    ((blkid_le32(es->s_feature_incompat) &
159	      EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0))
160		blkid_set_tag(dev, "SEC_TYPE", "ext2", sizeof("ext2"));
161}
162
163/*
164 * Check to see if a filesystem is in /proc/filesystems.
165 * Returns 1 if found, 0 if not
166 */
167static int fs_proc_check(const char *fs_name)
168{
169	FILE	*f;
170	char	buf[80], *cp, *t;
171
172	f = fopen("/proc/filesystems", "r");
173	if (!f)
174		return (0);
175	while (!feof(f)) {
176		if (!fgets(buf, sizeof(buf), f))
177			break;
178		cp = buf;
179		if (!isspace(*cp)) {
180			while (*cp && !isspace(*cp))
181				cp++;
182		}
183		while (*cp && isspace(*cp))
184			cp++;
185		if ((t = strchr(cp, '\n')) != NULL)
186			*t = 0;
187		if ((t = strchr(cp, '\t')) != NULL)
188			*t = 0;
189		if ((t = strchr(cp, ' ')) != NULL)
190			*t = 0;
191		if (!strcmp(fs_name, cp)) {
192			fclose(f);
193			return (1);
194		}
195	}
196	fclose(f);
197	return (0);
198}
199
200/*
201 * Check to see if a filesystem is available as a module
202 * Returns 1 if found, 0 if not
203 */
204static int check_for_modules(const char *fs_name)
205{
206	struct utsname	uts;
207	FILE		*f;
208	char		buf[1024], *cp, *t;
209	int		i;
210
211	if (uname(&uts))
212		return (0);
213	snprintf(buf, sizeof(buf), "/lib/modules/%s/modules.dep", uts.release);
214
215	f = fopen(buf, "r");
216	if (!f)
217		return (0);
218	while (!feof(f)) {
219		if (!fgets(buf, sizeof(buf), f))
220			break;
221		if ((cp = strchr(buf, ':')) != NULL)
222			*cp = 0;
223		else
224			continue;
225		if ((cp = strrchr(buf, '/')) != NULL)
226			cp++;
227		i = strlen(cp);
228		if (i > 3) {
229			t = cp + i - 3;
230			if (!strcmp(t, ".ko"))
231				*t = 0;
232		}
233		if (!strcmp(cp, fs_name))
234			return (1);
235	}
236	fclose(f);
237	return (0);
238}
239
240static int system_supports_ext4(void)
241{
242	static time_t	last_check = 0;
243	static int	ret = -1;
244	time_t		now = time(0);
245
246	if (ret != -1 || (last_check - now) < 5)
247		return ret;
248	last_check = now;
249	ret = (fs_proc_check("ext4") || check_for_modules("ext4"));
250	return ret;
251}
252
253static int system_supports_ext4dev(void)
254{
255	static time_t	last_check = 0;
256	static int	ret = -1;
257	time_t		now = time(0);
258
259	if (ret != -1 || (last_check - now) < 5)
260		return ret;
261	last_check = now;
262	ret = (fs_proc_check("ext4dev") || check_for_modules("ext4dev"));
263	return ret;
264}
265
266static int probe_ext4dev(struct blkid_probe *probe,
267			 struct blkid_magic *id,
268			 unsigned char *buf)
269{
270	struct ext2_super_block *es;
271	es = (struct ext2_super_block *)buf;
272
273	/* Distinguish from jbd */
274	if (blkid_le32(es->s_feature_incompat) &
275	    EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
276		return -BLKID_ERR_PARAM;
277
278	/* ext4dev requires a journal */
279	if (!(blkid_le32(es->s_feature_compat) &
280	      EXT3_FEATURE_COMPAT_HAS_JOURNAL))
281		return -BLKID_ERR_PARAM;
282
283	/*
284	 * If the filesystem is marked as OK for use by in-development
285	 * filesystem code, but ext4dev is not supported, and ext4 is,
286	 * then don't call ourselves ext4dev, since we should be
287	 * detected as ext4 in that case.
288	 *
289	 * If the filesystem is marked as in use by production
290	 * filesystem, then it can only be used by ext4 and NOT by
291	 * ext4dev, so always disclaim we are ext4dev in that case.
292	 */
293	if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) {
294		if (!system_supports_ext4dev() && system_supports_ext4())
295			return -BLKID_ERR_PARAM;
296	} else
297		return -BLKID_ERR_PARAM;
298
299    	get_ext2_info(probe->dev, id, buf);
300	return 0;
301}
302
303static int probe_ext4(struct blkid_probe *probe, struct blkid_magic *id,
304		      unsigned char *buf)
305{
306	struct ext2_super_block *es;
307	es = (struct ext2_super_block *)buf;
308
309	/* Distinguish from jbd */
310	if (blkid_le32(es->s_feature_incompat) &
311	    EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
312		return -BLKID_ERR_PARAM;
313
314	/* ext4 requires journal */
315	if (!(blkid_le32(es->s_feature_compat) &
316	      EXT3_FEATURE_COMPAT_HAS_JOURNAL))
317		return -BLKID_ERR_PARAM;
318
319	/* Ext4 has at least one feature which ext3 doesn't understand */
320	if (!(blkid_le32(es->s_feature_ro_compat) &
321	      EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) &&
322	    !(blkid_le32(es->s_feature_incompat) &
323	      EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
324		return -BLKID_ERR_PARAM;
325
326	/*
327	 * If the filesystem is a OK for use by in-development
328	 * filesystem code, and ext4dev is supported or ext4 is not
329	 * supported, then don't call ourselves ext4, so we can redo
330	 * the detection and mark the filesystem as ext4dev.
331	 *
332	 * If the filesystem is marked as in use by production
333	 * filesystem, then it can only be used by ext4 and NOT by
334	 * ext4dev.
335	 */
336	if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) {
337		if (system_supports_ext4dev() || !system_supports_ext4())
338			return -BLKID_ERR_PARAM;
339	}
340    	get_ext2_info(probe->dev, id, buf);
341	return 0;
342}
343
344static int probe_ext3(struct blkid_probe *probe, struct blkid_magic *id,
345		      unsigned char *buf)
346{
347	struct ext2_super_block *es;
348	es = (struct ext2_super_block *)buf;
349
350	/* Distinguish from ext4dev */
351	if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)
352		return -BLKID_ERR_PARAM;
353
354	/* ext3 requires journal */
355	if (!(blkid_le32(es->s_feature_compat) &
356	      EXT3_FEATURE_COMPAT_HAS_JOURNAL))
357		return -BLKID_ERR_PARAM;
358
359	/* Any features which ext3 doesn't understand */
360	if ((blkid_le32(es->s_feature_ro_compat) &
361	     EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) ||
362	    (blkid_le32(es->s_feature_incompat) &
363	     EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
364		return -BLKID_ERR_PARAM;
365
366    	get_ext2_info(probe->dev, id, buf);
367	return 0;
368}
369
370static int probe_ext2(struct blkid_probe *probe, struct blkid_magic *id,
371		      unsigned char *buf)
372{
373	struct ext2_super_block *es;
374
375	es = (struct ext2_super_block *)buf;
376
377	/* Distinguish between ext3 and ext2 */
378	if ((blkid_le32(es->s_feature_compat) &
379	      EXT3_FEATURE_COMPAT_HAS_JOURNAL))
380		return -BLKID_ERR_PARAM;
381
382	/* Any features which ext2 doesn't understand */
383	if ((blkid_le32(es->s_feature_ro_compat) &
384	     EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) ||
385	    (blkid_le32(es->s_feature_incompat) &
386	     EXT2_FEATURE_INCOMPAT_UNSUPPORTED))
387		return -BLKID_ERR_PARAM;
388
389	get_ext2_info(probe->dev, id, buf);
390	return 0;
391}
392
393static int probe_jbd(struct blkid_probe *probe, struct blkid_magic *id,
394		     unsigned char *buf)
395{
396	struct ext2_super_block *es = (struct ext2_super_block *) buf;
397
398	if (!(blkid_le32(es->s_feature_incompat) &
399	      EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
400		return -BLKID_ERR_PARAM;
401
402	get_ext2_info(probe->dev, id, buf);
403
404	return 0;
405}
406
407#define FAT_ATTR_VOLUME_ID		0x08
408#define FAT_ATTR_DIR			0x10
409#define FAT_ATTR_LONG_NAME		0x0f
410#define FAT_ATTR_MASK			0x3f
411#define FAT_ENTRY_FREE			0xe5
412
413static const char *no_name = "NO NAME    ";
414
415static unsigned char *search_fat_label(struct vfat_dir_entry *dir, int count)
416{
417	int i;
418
419	for (i = 0; i < count; i++) {
420		if (dir[i].name[0] == 0x00)
421			break;
422
423		if ((dir[i].name[0] == FAT_ENTRY_FREE) ||
424		    (dir[i].cluster_high != 0 || dir[i].cluster_low != 0) ||
425		    ((dir[i].attr & FAT_ATTR_MASK) == FAT_ATTR_LONG_NAME))
426			continue;
427
428		if ((dir[i].attr & (FAT_ATTR_VOLUME_ID | FAT_ATTR_DIR)) ==
429		    FAT_ATTR_VOLUME_ID) {
430			return dir[i].name;
431		}
432	}
433	return 0;
434}
435
436/* FAT label extraction from the root directory taken from Kay
437 * Sievers's volume_id library */
438static int probe_fat(struct blkid_probe *probe,
439		      struct blkid_magic *id __BLKID_ATTR((unused)),
440		      unsigned char *buf)
441{
442	struct vfat_super_block *vs = (struct vfat_super_block *) buf;
443	struct msdos_super_block *ms = (struct msdos_super_block *) buf;
444	struct vfat_dir_entry *dir;
445	char serno[10];
446	const unsigned char *label = 0, *vol_label = 0, *tmp;
447	unsigned char	*vol_serno;
448	int label_len = 0, maxloop = 100;
449	__u16 sector_size, dir_entries, reserved;
450	__u32 sect_count, fat_size, dir_size, cluster_count, fat_length;
451	__u32 buf_size, start_data_sect, next, root_start, root_dir_entries;
452
453	/* sector size check */
454	tmp = (unsigned char *)&ms->ms_sector_size;
455	sector_size = tmp[0] + (tmp[1] << 8);
456	if (sector_size != 0x200 && sector_size != 0x400 &&
457	    sector_size != 0x800 && sector_size != 0x1000)
458		return 1;
459
460	tmp = (unsigned char *)&ms->ms_dir_entries;
461	dir_entries = tmp[0] + (tmp[1] << 8);
462	reserved =  blkid_le16(ms->ms_reserved);
463	tmp = (unsigned char *)&ms->ms_sectors;
464	sect_count = tmp[0] + (tmp[1] << 8);
465	if (sect_count == 0)
466		sect_count = blkid_le32(ms->ms_total_sect);
467
468	fat_length = blkid_le16(ms->ms_fat_length);
469	if (fat_length == 0)
470		fat_length = blkid_le32(vs->vs_fat32_length);
471
472	fat_size = fat_length * ms->ms_fats;
473	dir_size = ((dir_entries * sizeof(struct vfat_dir_entry)) +
474			(sector_size-1)) / sector_size;
475
476	cluster_count = sect_count - (reserved + fat_size + dir_size);
477	if (ms->ms_cluster_size == 0)
478		return 1;
479	cluster_count /= ms->ms_cluster_size;
480
481	if (cluster_count > FAT32_MAX)
482		return 1;
483
484	if (ms->ms_fat_length) {
485		/* the label may be an attribute in the root directory */
486		root_start = (reserved + fat_size) * sector_size;
487		root_dir_entries = vs->vs_dir_entries[0] +
488			(vs->vs_dir_entries[1] << 8);
489
490		buf_size = root_dir_entries * sizeof(struct vfat_dir_entry);
491		dir = (struct vfat_dir_entry *) get_buffer(probe, root_start,
492							   buf_size);
493		if (dir)
494			vol_label = search_fat_label(dir, root_dir_entries);
495
496		if (!vol_label || !memcmp(vol_label, no_name, 11))
497			vol_label = ms->ms_label;
498		vol_serno = ms->ms_serno;
499
500		blkid_set_tag(probe->dev, "SEC_TYPE", "msdos",
501			      sizeof("msdos"));
502	} else {
503		/* Search the FAT32 root dir for the label attribute */
504		buf_size = vs->vs_cluster_size * sector_size;
505		start_data_sect = reserved + fat_size;
506
507		next = blkid_le32(vs->vs_root_cluster);
508		while (next && --maxloop) {
509			__u32 next_sect_off;
510			__u64 next_off, fat_entry_off;
511			int count;
512
513			next_sect_off = (next - 2) * vs->vs_cluster_size;
514			next_off = (start_data_sect + next_sect_off) *
515				sector_size;
516
517			dir = (struct vfat_dir_entry *)
518				get_buffer(probe, next_off, buf_size);
519			if (dir == NULL)
520				break;
521
522			count = buf_size / sizeof(struct vfat_dir_entry);
523
524			vol_label = search_fat_label(dir, count);
525			if (vol_label)
526				break;
527
528			/* get FAT entry */
529			fat_entry_off = (reserved * sector_size) +
530				(next * sizeof(__u32));
531			buf = get_buffer(probe, fat_entry_off, buf_size);
532			if (buf == NULL)
533				break;
534
535			/* set next cluster */
536			next = blkid_le32(*((__u32 *) buf) & 0x0fffffff);
537		}
538
539		if (!vol_label || !memcmp(vol_label, no_name, 11))
540			vol_label = vs->vs_label;
541		vol_serno = vs->vs_serno;
542	}
543
544	if (vol_label && memcmp(vol_label, no_name, 11)) {
545		if ((label_len = figure_label_len(vol_label, 11)))
546			label = vol_label;
547	}
548
549	/* We can't just print them as %04X, because they are unaligned */
550	sprintf(serno, "%02X%02X-%02X%02X", vol_serno[3], vol_serno[2],
551		vol_serno[1], vol_serno[0]);
552
553	blkid_set_tag(probe->dev, "LABEL", (const char *) label, label_len);
554	blkid_set_tag(probe->dev, "UUID", serno, sizeof(serno)-1);
555
556	return 0;
557}
558
559/*
560 * The FAT filesystem could be without a magic string in superblock
561 * (e.g. old floppies).  This heuristic for FAT detection is inspired
562 * by http://vrfy.org/projects/volume_id/ and Linux kernel.
563 * [7-Jul-2005, Karel Zak <kzak@redhat.com>]
564 */
565static int probe_fat_nomagic(struct blkid_probe *probe,
566			     struct blkid_magic *id __BLKID_ATTR((unused)),
567			     unsigned char *buf)
568{
569	struct vfat_super_block *vs;
570
571	vs = (struct vfat_super_block *)buf;
572
573	/* heads check */
574	if (vs->vs_heads == 0)
575		return 1;
576
577	/* cluster size check*/
578	if (vs->vs_cluster_size == 0 ||
579	    (vs->vs_cluster_size & (vs->vs_cluster_size-1)))
580		return 1;
581
582	/* media check */
583	if (vs->vs_media < 0xf8 && vs->vs_media != 0xf0)
584		return 1;
585
586	/* fat counts(Linux kernel expects at least 1 FAT table) */
587	if (!vs->vs_fats)
588		return 1;
589
590	return probe_fat(probe, id, buf);
591}
592
593static int probe_ntfs(struct blkid_probe *probe,
594		      struct blkid_magic *id __BLKID_ATTR((unused)),
595		      unsigned char *buf)
596{
597	struct ntfs_super_block *ns;
598	struct master_file_table_record *mft;
599	struct file_attribute *attr;
600	char		uuid_str[17], label_str[129], *cp;
601	int		bytes_per_sector, sectors_per_cluster;
602	int		mft_record_size, attr_off, attr_len;
603	unsigned int	i, attr_type, val_len;
604	int		val_off;
605	__u64		nr_clusters;
606	blkid_loff_t off;
607	unsigned char *buf_mft, *val;
608
609	ns = (struct ntfs_super_block *) buf;
610
611	bytes_per_sector = ns->bios_parameter_block[0] +
612		(ns->bios_parameter_block[1]  << 8);
613	sectors_per_cluster = ns->bios_parameter_block[2];
614
615	if ((bytes_per_sector < 512) || (sectors_per_cluster == 0))
616		return 1;
617
618	if (ns->cluster_per_mft_record < 0)
619		mft_record_size = 1 << (0-ns->cluster_per_mft_record);
620	else
621		mft_record_size = ns->cluster_per_mft_record *
622			sectors_per_cluster * bytes_per_sector;
623	nr_clusters = blkid_le64(ns->number_of_sectors) / sectors_per_cluster;
624
625	if ((blkid_le64(ns->mft_cluster_location) > nr_clusters) ||
626	    (blkid_le64(ns->mft_mirror_cluster_location) > nr_clusters))
627		return 1;
628
629	off = blkid_le64(ns->mft_mirror_cluster_location) *
630		bytes_per_sector * sectors_per_cluster;
631
632	buf_mft = get_buffer(probe, off, mft_record_size);
633	if (!buf_mft)
634		return 1;
635
636	if (memcmp(buf_mft, "FILE", 4))
637		return 1;
638
639	off = blkid_le64(ns->mft_cluster_location) * bytes_per_sector *
640		sectors_per_cluster;
641
642	buf_mft = get_buffer(probe, off, mft_record_size);
643	if (!buf_mft)
644		return 1;
645
646	if (memcmp(buf_mft, "FILE", 4))
647		return 1;
648
649	off += MFT_RECORD_VOLUME * mft_record_size;
650
651	buf_mft = get_buffer(probe, off, mft_record_size);
652	if (!buf_mft)
653		return 1;
654
655	if (memcmp(buf_mft, "FILE", 4))
656		return 1;
657
658	mft = (struct master_file_table_record *) buf_mft;
659
660	attr_off = blkid_le16(mft->attrs_offset);
661	label_str[0] = 0;
662
663	while (1) {
664		attr = (struct file_attribute *) (buf_mft + attr_off);
665		attr_len = blkid_le16(attr->len);
666		attr_type = blkid_le32(attr->type);
667		val_off = blkid_le16(attr->value_offset);
668		val_len = blkid_le32(attr->value_len);
669
670		attr_off += attr_len;
671
672		if ((attr_off > mft_record_size) ||
673		    (attr_len == 0))
674			break;
675
676		if (attr_type == MFT_RECORD_ATTR_END)
677			break;
678
679		if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
680			if (val_len > sizeof(label_str))
681				val_len = sizeof(label_str)-1;
682
683			for (i=0, cp=label_str; i < val_len; i+=2,cp++) {
684				val = ((__u8 *) attr) + val_off + i;
685				*cp = val[0];
686				if (val[1])
687					*cp = '?';
688			}
689			*cp = 0;
690		}
691	}
692
693	sprintf(uuid_str, "%016llX", blkid_le64(ns->volume_serial));
694	blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
695	if (label_str[0])
696		blkid_set_tag(probe->dev, "LABEL", label_str, 0);
697	return 0;
698}
699
700
701static int probe_xfs(struct blkid_probe *probe,
702		     struct blkid_magic *id __BLKID_ATTR((unused)),
703		     unsigned char *buf)
704{
705	struct xfs_super_block *xs;
706	const char *label = 0;
707
708	xs = (struct xfs_super_block *)buf;
709
710	if (strlen(xs->xs_fname))
711		label = xs->xs_fname;
712	blkid_set_tag(probe->dev, "LABEL", label, sizeof(xs->xs_fname));
713	set_uuid(probe->dev, xs->xs_uuid, 0);
714	return 0;
715}
716
717static int probe_reiserfs(struct blkid_probe *probe,
718			  struct blkid_magic *id, unsigned char *buf)
719{
720	struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
721	unsigned int blocksize;
722	const char *label = 0;
723
724	blocksize = blkid_le16(rs->rs_blocksize);
725
726	/* The blocksize must be at least 1k */
727	if ((blocksize >> 10) == 0)
728		return -BLKID_ERR_PARAM;
729
730	/* If the superblock is inside the journal, we have the wrong one */
731	if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
732		return -BLKID_ERR_BIG;
733
734	/* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
735	if (id->bim_magic[6] == '2' || id->bim_magic[6] == '3') {
736		if (strlen(rs->rs_label))
737			label = rs->rs_label;
738		set_uuid(probe->dev, rs->rs_uuid, 0);
739	}
740	blkid_set_tag(probe->dev, "LABEL", label, sizeof(rs->rs_label));
741
742	return 0;
743}
744
745static int probe_reiserfs4(struct blkid_probe *probe,
746			   struct blkid_magic *id __BLKID_ATTR((unused)),
747			   unsigned char *buf)
748{
749	struct reiser4_super_block *rs4 = (struct reiser4_super_block *) buf;
750	const unsigned char *label = 0;
751
752	if (strlen((char *) rs4->rs4_label))
753		label = rs4->rs4_label;
754	set_uuid(probe->dev, rs4->rs4_uuid, 0);
755	blkid_set_tag(probe->dev, "LABEL", (const char *) label,
756		      sizeof(rs4->rs4_label));
757
758	return 0;
759}
760
761static int probe_jfs(struct blkid_probe *probe,
762		     struct blkid_magic *id __BLKID_ATTR((unused)),
763		     unsigned char *buf)
764{
765	struct jfs_super_block *js;
766	const char *label = 0;
767
768	js = (struct jfs_super_block *)buf;
769
770	if (strlen((char *) js->js_label))
771		label = (char *) js->js_label;
772	blkid_set_tag(probe->dev, "LABEL", label, sizeof(js->js_label));
773	set_uuid(probe->dev, js->js_uuid, 0);
774	return 0;
775}
776
777static int probe_luks(struct blkid_probe *probe,
778		       struct blkid_magic *id __BLKID_ATTR((unused)),
779		       unsigned char *buf)
780{
781	char uuid[40];
782	/* 168 is the offset to the 40 character uuid:
783	 * http://luks.endorphin.org/LUKS-on-disk-format.pdf */
784	strncpy(uuid, (char *) buf+168, 40);
785	blkid_set_tag(probe->dev, "UUID", uuid, sizeof(uuid));
786	return 0;
787}
788
789static int probe_romfs(struct blkid_probe *probe,
790		       struct blkid_magic *id __BLKID_ATTR((unused)),
791		       unsigned char *buf)
792{
793	struct romfs_super_block *ros;
794	const char *label = 0;
795
796	ros = (struct romfs_super_block *)buf;
797
798	if (strlen((char *) ros->ros_volume))
799		label = (char *) ros->ros_volume;
800	blkid_set_tag(probe->dev, "LABEL", label, 0);
801	return 0;
802}
803
804static int probe_cramfs(struct blkid_probe *probe,
805			struct blkid_magic *id __BLKID_ATTR((unused)),
806			unsigned char *buf)
807{
808	struct cramfs_super_block *csb;
809	const char *label = 0;
810
811	csb = (struct cramfs_super_block *)buf;
812
813	if (strlen((char *) csb->name))
814		label = (char *) csb->name;
815	blkid_set_tag(probe->dev, "LABEL", label, 0);
816	return 0;
817}
818
819static int probe_swap0(struct blkid_probe *probe,
820		       struct blkid_magic *id __BLKID_ATTR((unused)),
821		       unsigned char *buf __BLKID_ATTR((unused)))
822{
823	blkid_set_tag(probe->dev, "UUID", 0, 0);
824	blkid_set_tag(probe->dev, "LABEL", 0, 0);
825	return 0;
826}
827
828static int probe_swap1(struct blkid_probe *probe,
829		       struct blkid_magic *id __BLKID_ATTR((unused)),
830		       unsigned char *buf __BLKID_ATTR((unused)))
831{
832	struct swap_id_block *sws;
833
834	probe_swap0(probe, id, buf);
835	/*
836	 * Version 1 swap headers are always located at offset of 1024
837	 * bytes, although the swap signature itself is located at the
838	 * end of the page (which may vary depending on hardware
839	 * pagesize).
840	 */
841	sws = (struct swap_id_block *) get_buffer(probe, 1024, 1024);
842	if (!sws)
843		return 1;
844
845	/* arbitrary sanity check.. is there any garbage down there? */
846	if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0)  {
847		if (sws->sws_volume[0])
848			blkid_set_tag(probe->dev, "LABEL", sws->sws_volume,
849				      sizeof(sws->sws_volume));
850		if (sws->sws_uuid[0])
851			set_uuid(probe->dev, sws->sws_uuid, 0);
852	}
853	return 0;
854}
855
856static int probe_iso9660(struct blkid_probe *probe,
857			 struct blkid_magic *id __BLKID_ATTR((unused)),
858			 unsigned char *buf)
859{
860	struct iso_volume_descriptor *iso;
861	const unsigned char *label;
862
863	iso = (struct iso_volume_descriptor *) buf;
864	label = iso->volume_id;
865
866	blkid_set_tag(probe->dev, "LABEL", (const char *) label,
867		      figure_label_len(label, 32));
868	return 0;
869}
870
871
872static const char
873*udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
874		 "NSR03", "TEA01", 0 };
875
876static int probe_udf(struct blkid_probe *probe,
877		     struct blkid_magic *id __BLKID_ATTR((unused)),
878		     unsigned char *buf __BLKID_ATTR((unused)))
879{
880	int j, bs;
881	struct iso_volume_descriptor *isosb;
882	const char ** m;
883
884	/* determine the block size by scanning in 2K increments
885	   (block sizes larger than 2K will be null padded) */
886	for (bs = 1; bs < 16; bs++) {
887		isosb = (struct iso_volume_descriptor *)
888			get_buffer(probe, bs*2048+32768, sizeof(isosb));
889		if (!isosb)
890			return 1;
891		if (isosb->vd_id[0])
892			break;
893	}
894
895	/* Scan up to another 64 blocks looking for additional VSD's */
896	for (j = 1; j < 64; j++) {
897		if (j > 1) {
898			isosb = (struct iso_volume_descriptor *)
899				get_buffer(probe, j*bs*2048+32768,
900					   sizeof(isosb));
901			if (!isosb)
902				return 1;
903		}
904		/* If we find NSR0x then call it udf:
905		   NSR01 for UDF 1.00
906		   NSR02 for UDF 1.50
907		   NSR03 for UDF 2.00 */
908		if (!memcmp(isosb->vd_id, "NSR0", 4))
909			return probe_iso9660(probe, id, buf);
910		for (m = udf_magic; *m; m++)
911			if (!memcmp(*m, isosb->vd_id, 5))
912				break;
913		if (*m == 0)
914			return 1;
915	}
916	return 1;
917}
918
919static int probe_ocfs(struct blkid_probe *probe,
920		      struct blkid_magic *id __BLKID_ATTR((unused)),
921		      unsigned char *buf)
922{
923	struct ocfs_volume_header ovh;
924	struct ocfs_volume_label ovl;
925	__u32 major;
926
927	memcpy(&ovh, buf, sizeof(ovh));
928	memcpy(&ovl, buf+512, sizeof(ovl));
929
930	major = ocfsmajor(ovh);
931	if (major == 1)
932		blkid_set_tag(probe->dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
933	else if (major >= 9)
934		blkid_set_tag(probe->dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
935
936	blkid_set_tag(probe->dev, "LABEL", ovl.label, ocfslabellen(ovl));
937	blkid_set_tag(probe->dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
938	set_uuid(probe->dev, ovl.vol_id, 0);
939	return 0;
940}
941
942static int probe_ocfs2(struct blkid_probe *probe,
943		       struct blkid_magic *id __BLKID_ATTR((unused)),
944		       unsigned char *buf)
945{
946	struct ocfs2_super_block *osb;
947
948	osb = (struct ocfs2_super_block *)buf;
949
950	blkid_set_tag(probe->dev, "LABEL", osb->s_label, sizeof(osb->s_label));
951	set_uuid(probe->dev, osb->s_uuid, 0);
952	return 0;
953}
954
955static int probe_oracleasm(struct blkid_probe *probe,
956			   struct blkid_magic *id __BLKID_ATTR((unused)),
957			   unsigned char *buf)
958{
959	struct oracle_asm_disk_label *dl;
960
961	dl = (struct oracle_asm_disk_label *)buf;
962
963	blkid_set_tag(probe->dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
964	return 0;
965}
966
967static int probe_gfs(struct blkid_probe *probe,
968		     struct blkid_magic *id __BLKID_ATTR((unused)),
969		     unsigned char *buf)
970{
971	struct gfs2_sb *sbd;
972	const char *label = 0;
973
974	sbd = (struct gfs2_sb *)buf;
975
976	if (blkid_be32(sbd->sb_fs_format) == GFS_FORMAT_FS &&
977	    blkid_be32(sbd->sb_multihost_format) == GFS_FORMAT_MULTI)
978	{
979		blkid_set_tag(probe->dev, "UUID", 0, 0);
980
981		if (strlen(sbd->sb_locktable))
982			label = sbd->sb_locktable;
983		blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
984		return 0;
985	}
986	return 1;
987}
988
989static int probe_gfs2(struct blkid_probe *probe,
990		     struct blkid_magic *id __BLKID_ATTR((unused)),
991		     unsigned char *buf)
992{
993	struct gfs2_sb *sbd;
994	const char *label = 0;
995
996	sbd = (struct gfs2_sb *)buf;
997
998	if (blkid_be32(sbd->sb_fs_format) == GFS2_FORMAT_FS &&
999	    blkid_be32(sbd->sb_multihost_format) == GFS2_FORMAT_MULTI)
1000	{
1001		blkid_set_tag(probe->dev, "UUID", 0, 0);
1002
1003		if (strlen(sbd->sb_locktable))
1004			label = sbd->sb_locktable;
1005		blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
1006		return 0;
1007	}
1008	return 1;
1009}
1010
1011static int probe_hfsplus(struct blkid_probe *probe __BLKID_ATTR((unused)),
1012			 struct blkid_magic *id __BLKID_ATTR((unused)),
1013			 unsigned char *buf)
1014{
1015	struct hfs_mdb *sbd = (struct hfs_mdb *)buf;
1016
1017	/* Check for a HFS+ volume embedded in a HFS volume */
1018	if (memcmp(sbd->embed_sig, "H+", 2) == 0)
1019		return 0;
1020
1021	return 1;
1022}
1023
1024#define LVM2_LABEL_SIZE 512
1025static unsigned int lvm2_calc_crc(const void *buf, unsigned int size)
1026{
1027	static const unsigned int crctab[] = {
1028		0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
1029		0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
1030		0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
1031		0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
1032	};
1033	unsigned int i, crc = 0xf597a6cf;
1034	const __u8 *data = (const __u8 *) buf;
1035
1036	for (i = 0; i < size; i++) {
1037		crc ^= *data++;
1038		crc = (crc >> 4) ^ crctab[crc & 0xf];
1039		crc = (crc >> 4) ^ crctab[crc & 0xf];
1040	}
1041	return crc;
1042}
1043
1044static int probe_lvm2(struct blkid_probe *probe,
1045			struct blkid_magic *id __BLKID_ATTR((unused)),
1046			unsigned char *buf)
1047{
1048	int sector = (id->bim_kboff) << 1;;
1049	struct lvm2_pv_label_header *label;
1050	label = (struct lvm2_pv_label_header *)buf;
1051	char *p, *q, uuid[40];
1052	unsigned int i, b;
1053
1054	/* buf is at 0k or 1k offset; find label inside */
1055	if (memcmp(buf, "LABELONE", 8) == 0) {
1056		label = (struct lvm2_pv_label_header *)buf;
1057	} else if (memcmp(buf + 512, "LABELONE", 8) == 0) {
1058		label = (struct lvm2_pv_label_header *)(buf + 512);
1059		sector++;
1060	} else {
1061		return 1;
1062	}
1063
1064	if (blkid_le64(label->sector_xl) != (unsigned) sector) {
1065		DBG(DEBUG_PROBE,
1066		    printf("LVM2: label for sector %llu found at sector %d\n",
1067			   blkid_le64(label->sector_xl), sector));
1068		return 1;
1069	}
1070
1071	if (lvm2_calc_crc(&label->offset_xl, LVM2_LABEL_SIZE -
1072			  ((char *)&label->offset_xl - (char *)label)) !=
1073			blkid_le32(label->crc_xl)) {
1074		DBG(DEBUG_PROBE,
1075		    printf("LVM2: label checksum incorrect at sector %d\n",
1076			   sector));
1077		return 1;
1078	}
1079
1080	for (i=0, b=1, p=uuid, q= (char *) label->pv_uuid; i <= 32;
1081	     i++, b <<= 1) {
1082		if (b & 0x4444440)
1083			*p++ = '-';
1084		*p++ = *q++;
1085	}
1086
1087	blkid_set_tag(probe->dev, "UUID", uuid, LVM2_ID_LEN+6);
1088
1089	return 0;
1090}
1091/*
1092 * BLKID_BLK_OFFS is at least as large as the highest bim_kboff defined
1093 * in the type_array table below + bim_kbalign.
1094 *
1095 * When probing for a lot of magics, we handle everything in 1kB buffers so
1096 * that we don't have to worry about reading each combination of block sizes.
1097 */
1098#define BLKID_BLK_OFFS	64	/* currently reiserfs */
1099
1100/*
1101 * Various filesystem magics that we can check for.  Note that kboff and
1102 * sboff are in kilobytes and bytes respectively.  All magics are in
1103 * byte strings so we don't worry about endian issues.
1104 */
1105static struct blkid_magic type_array[] = {
1106/*  type     kboff   sboff len  magic			probe */
1107  { "oracleasm", 0,	32,  8, "ORCLDISK",		probe_oracleasm },
1108  { "ntfs",	 0,	 3,  8, "NTFS    ",		probe_ntfs },
1109  { "jbd",	 1,   0x38,  2, "\123\357",		probe_jbd },
1110  { "ext4dev",	 1,   0x38,  2, "\123\357",		probe_ext4dev },
1111  { "ext4",	 1,   0x38,  2, "\123\357",		probe_ext4 },
1112  { "ext3",	 1,   0x38,  2, "\123\357",		probe_ext3 },
1113  { "ext2",	 1,   0x38,  2, "\123\357",		probe_ext2 },
1114  { "reiserfs",	 8,   0x34,  8, "ReIsErFs",		probe_reiserfs },
1115  { "reiserfs", 64,   0x34,  9, "ReIsEr2Fs",		probe_reiserfs },
1116  { "reiserfs", 64,   0x34,  9, "ReIsEr3Fs",		probe_reiserfs },
1117  { "reiserfs", 64,   0x34,  8, "ReIsErFs",		probe_reiserfs },
1118  { "reiserfs",	 8,	20,  8, "ReIsErFs",		probe_reiserfs },
1119  { "reiser4",  64,	 0,  7, "ReIsEr4",		probe_reiserfs4 },
1120  { "gfs2",     64,      0,  4, "\x01\x16\x19\x70",     probe_gfs2 },
1121  { "gfs",      64,      0,  4, "\x01\x16\x19\x70",     probe_gfs },
1122  { "vfat",      0,   0x52,  5, "MSWIN",                probe_fat },
1123  { "vfat",      0,   0x52,  8, "FAT32   ",             probe_fat },
1124  { "vfat",      0,   0x36,  5, "MSDOS",                probe_fat },
1125  { "vfat",      0,   0x36,  8, "FAT16   ",             probe_fat },
1126  { "vfat",      0,   0x36,  8, "FAT12   ",             probe_fat },
1127  { "vfat",      0,      0,  1, "\353",                 probe_fat_nomagic },
1128  { "vfat",      0,      0,  1, "\351",                 probe_fat_nomagic },
1129  { "vfat",      0,  0x1fe,  2, "\125\252",             probe_fat_nomagic },
1130  { "minix",     1,   0x10,  2, "\177\023",             0 },
1131  { "minix",     1,   0x10,  2, "\217\023",             0 },
1132  { "minix",	 1,   0x10,  2, "\150\044",		0 },
1133  { "minix",	 1,   0x10,  2, "\170\044",		0 },
1134  { "vxfs",	 1,	 0,  4, "\365\374\001\245",	0 },
1135  { "xfs",	 0,	 0,  4, "XFSB",			probe_xfs },
1136  { "romfs",	 0,	 0,  8, "-rom1fs-",		probe_romfs },
1137  { "bfs",	 0,	 0,  4, "\316\372\173\033",	0 },
1138  { "cramfs",	 0,	 0,  4, "E=\315\050",		probe_cramfs },
1139  { "qnx4",	 0,	 4,  6, "QNX4FS",		0 },
1140  { "udf",	32,	 1,  5, "BEA01",		probe_udf },
1141  { "udf",	32,	 1,  5, "BOOT2",		probe_udf },
1142  { "udf",	32,	 1,  5, "CD001",		probe_udf },
1143  { "udf",	32,	 1,  5, "CDW02",		probe_udf },
1144  { "udf",	32,	 1,  5, "NSR02",		probe_udf },
1145  { "udf",	32,	 1,  5, "NSR03",		probe_udf },
1146  { "udf",	32,	 1,  5, "TEA01",		probe_udf },
1147  { "iso9660",	32,	 1,  5, "CD001",		probe_iso9660 },
1148  { "iso9660",	32,	 9,  5, "CDROM",		probe_iso9660 },
1149  { "jfs",	32,	 0,  4, "JFS1",			probe_jfs },
1150  { "hfsplus",	 1,	 0,  2, "BD",			probe_hfsplus },
1151  { "hfsplus",	 1,	 0,  2, "H+",			0 },
1152  { "hfs",	 1,	 0,  2, "BD",			0 },
1153  { "ufs",	 8,  0x55c,  4, "T\031\001\000",	0 },
1154  { "hpfs",	 8,	 0,  4, "I\350\225\371",	0 },
1155  { "sysv",	 0,  0x3f8,  4, "\020~\030\375",	0 },
1156  { "swap",	 0,  0xff6, 10, "SWAP-SPACE",		probe_swap0 },
1157  { "swap",	 0,  0xff6, 10, "SWAPSPACE2",		probe_swap1 },
1158  { "swsuspend", 0,  0xff6,  9, "S1SUSPEND",		probe_swap1 },
1159  { "swsuspend", 0,  0xff6,  9, "S2SUSPEND",		probe_swap1 },
1160  { "swap",	 0, 0x1ff6, 10, "SWAP-SPACE",		probe_swap0 },
1161  { "swap",	 0, 0x1ff6, 10, "SWAPSPACE2",		probe_swap1 },
1162  { "swsuspend", 0, 0x1ff6,  9, "S1SUSPEND",		probe_swap1 },
1163  { "swsuspend", 0, 0x1ff6,  9, "S2SUSPEND",		probe_swap1 },
1164  { "swap",	 0, 0x3ff6, 10, "SWAP-SPACE",		probe_swap0 },
1165  { "swap",	 0, 0x3ff6, 10, "SWAPSPACE2",		probe_swap1 },
1166  { "swsuspend", 0, 0x3ff6,  9, "S1SUSPEND",		probe_swap1 },
1167  { "swsuspend", 0, 0x3ff6,  9, "S2SUSPEND",		probe_swap1 },
1168  { "swap",	 0, 0x7ff6, 10, "SWAP-SPACE",		probe_swap0 },
1169  { "swap",	 0, 0x7ff6, 10, "SWAPSPACE2",		probe_swap1 },
1170  { "swsuspend", 0, 0x7ff6,  9, "S1SUSPEND",		probe_swap1 },
1171  { "swsuspend", 0, 0x7ff6,  9, "S2SUSPEND",		probe_swap1 },
1172  { "swap",	 0, 0xfff6, 10, "SWAP-SPACE",		probe_swap0 },
1173  { "swap",	 0, 0xfff6, 10, "SWAPSPACE2",		probe_swap1 },
1174  { "swsuspend", 0, 0xfff6,  9, "S1SUSPEND",		probe_swap1 },
1175  { "swsuspend", 0, 0xfff6,  9, "S2SUSPEND",		probe_swap1 },
1176  { "ocfs",	 0,	 8,  9,	"OracleCFS",		probe_ocfs },
1177  { "ocfs2",	 1,	 0,  6,	"OCFSV2",		probe_ocfs2 },
1178  { "ocfs2",	 2,	 0,  6,	"OCFSV2",		probe_ocfs2 },
1179  { "ocfs2",	 4,	 0,  6,	"OCFSV2",		probe_ocfs2 },
1180  { "ocfs2",	 8,	 0,  6,	"OCFSV2",		probe_ocfs2 },
1181  { "crypt_LUKS", 0,	 0,  6,	"LUKS\xba\xbe",		probe_luks },
1182  { "squashfs",	 0,	 0,  4,	"sqsh",			0 },
1183  { "squashfs",	 0,	 0,  4,	"hsqs",			0 },
1184  { "lvm2pv",	 0,  0x218,  8, "LVM2 001",		probe_lvm2 },
1185  { "lvm2pv",	 0,  0x018,  8, "LVM2 001",		probe_lvm2 },
1186  { "lvm2pv",	 1,  0x018,  8, "LVM2 001",		probe_lvm2 },
1187  { "lvm2pv",	 1,  0x218,  8, "LVM2 001",		probe_lvm2 },
1188  {   NULL,	 0,	 0,  0, NULL,			NULL }
1189};
1190
1191/*
1192 * Verify that the data in dev is consistent with what is on the actual
1193 * block device (using the devname field only).  Normally this will be
1194 * called when finding items in the cache, but for long running processes
1195 * is also desirable to revalidate an item before use.
1196 *
1197 * If we are unable to revalidate the data, we return the old data and
1198 * do not set the BLKID_BID_FL_VERIFIED flag on it.
1199 */
1200blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
1201{
1202	struct blkid_magic *id;
1203	struct blkid_probe probe;
1204	blkid_tag_iterate iter;
1205	unsigned char *buf;
1206	const char *type, *value;
1207	struct stat st;
1208	time_t diff, now;
1209	int idx;
1210
1211	if (!dev)
1212		return NULL;
1213
1214	now = time(0);
1215	diff = now - dev->bid_time;
1216
1217	if ((now > dev->bid_time) && (diff > 0) &&
1218	    ((diff < BLKID_PROBE_MIN) ||
1219	     (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
1220	      diff < BLKID_PROBE_INTERVAL)))
1221		return dev;
1222
1223	DBG(DEBUG_PROBE,
1224	    printf("need to revalidate %s (time since last check %llu)\n",
1225		   dev->bid_name, (unsigned long long)diff));
1226
1227	if (((probe.fd = open(dev->bid_name, O_RDONLY)) < 0) ||
1228	    (fstat(probe.fd, &st) < 0)) {
1229		if (probe.fd >= 0) close(probe.fd);
1230		if (errno != EPERM) {
1231			blkid_free_dev(dev);
1232			return NULL;
1233		}
1234		/* We don't have read permission, just return cache data. */
1235		DBG(DEBUG_PROBE,
1236		    printf("returning unverified data for %s\n",
1237			   dev->bid_name));
1238		return dev;
1239	}
1240
1241	probe.cache = cache;
1242	probe.dev = dev;
1243	probe.sbbuf = 0;
1244	probe.buf = 0;
1245	probe.buf_max = 0;
1246
1247	/*
1248	 * Iterate over the type array.  If we already know the type,
1249	 * then try that first.  If it doesn't work, then blow away
1250	 * the type information, and try again.
1251	 *
1252	 */
1253try_again:
1254	type = 0;
1255	if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
1256		uuid_t	uuid;
1257
1258		if (check_mdraid(probe.fd, uuid) == 0) {
1259			set_uuid(dev, uuid, 0);
1260			type = "mdraid";
1261			goto found_type;
1262		}
1263	}
1264	for (id = type_array; id->bim_type; id++) {
1265		if (dev->bid_type &&
1266		    strcmp(id->bim_type, dev->bid_type))
1267			continue;
1268
1269		idx = id->bim_kboff + (id->bim_sboff >> 10);
1270		buf = get_buffer(&probe, idx << 10, 1024);
1271		if (!buf)
1272			continue;
1273
1274		if (memcmp(id->bim_magic, buf + (id->bim_sboff&0x3ff),
1275			   id->bim_len))
1276			continue;
1277
1278		if ((id->bim_probe == NULL) ||
1279		    (id->bim_probe(&probe, id, buf) == 0)) {
1280			type = id->bim_type;
1281			goto found_type;
1282		}
1283	}
1284
1285	if (!id->bim_type && dev->bid_type) {
1286		/*
1287		 * Zap the device filesystem information and try again
1288		 */
1289		DBG(DEBUG_PROBE,
1290		    printf("previous fs type %s not valid, "
1291			   "trying full probe\n", dev->bid_type));
1292		iter = blkid_tag_iterate_begin(dev);
1293		while (blkid_tag_next(iter, &type, &value) == 0)
1294			blkid_set_tag(dev, type, 0, 0);
1295		blkid_tag_iterate_end(iter);
1296		goto try_again;
1297	}
1298
1299	if (!dev->bid_type) {
1300		blkid_free_dev(dev);
1301		dev = 0;
1302		goto found_type;
1303	}
1304
1305found_type:
1306	if (dev && type) {
1307		dev->bid_devno = st.st_rdev;
1308		dev->bid_time = time(0);
1309		dev->bid_flags |= BLKID_BID_FL_VERIFIED;
1310		cache->bic_flags |= BLKID_BIC_FL_CHANGED;
1311
1312		blkid_set_tag(dev, "TYPE", type, 0);
1313
1314		DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
1315			   dev->bid_name, (long long)st.st_rdev, type));
1316	}
1317
1318	if (probe.sbbuf)
1319		free(probe.sbbuf);
1320	if (probe.buf)
1321		free(probe.buf);
1322	if (probe.fd >= 0)
1323		close(probe.fd);
1324
1325	return dev;
1326}
1327
1328int blkid_known_fstype(const char *fstype)
1329{
1330	struct blkid_magic *id;
1331
1332	for (id = type_array; id->bim_type; id++) {
1333		if (strcmp(fstype, id->bim_type) == 0)
1334			return 1;
1335	}
1336	return 0;
1337}
1338
1339#ifdef TEST_PROGRAM
1340int main(int argc, char **argv)
1341{
1342	blkid_dev dev;
1343	blkid_cache cache;
1344	int ret;
1345
1346	if (argc != 2) {
1347		fprintf(stderr, "Usage: %s device\n"
1348			"Probe a single device to determine type\n", argv[0]);
1349		exit(1);
1350	}
1351	if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
1352		fprintf(stderr, "%s: error creating cache (%d)\n",
1353			argv[0], ret);
1354		exit(1);
1355	}
1356	dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
1357	if (!dev) {
1358		printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
1359		return (1);
1360	}
1361	printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");
1362	if (dev->bid_label)
1363		printf("LABEL='%s'\n", dev->bid_label);
1364	if (dev->bid_uuid)
1365		printf("UUID='%s'\n", dev->bid_uuid);
1366
1367	blkid_free_dev(dev);
1368	return (0);
1369}
1370#endif
1371