probe.c revision 292811f2aaa39c3f1ee2cbb56fe2b586f8337946
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 <sys/types.h>
22#ifdef HAVE_SYS_STAT_H
23#include <sys/stat.h>
24#endif
25#ifdef HAVE_SYS_MKDEV_H
26#include <sys/mkdev.h>
27#endif
28#ifdef HAVE_ERRNO_H
29#include <errno.h>
30#endif
31#include "blkidP.h"
32#include "uuid/uuid.h"
33#include "probe.h"
34
35static int figure_label_len(const unsigned char *label, int len)
36{
37	const unsigned char *end = label + len - 1;
38
39	while ((*end == ' ' || *end == 0) && end >= label)
40		--end;
41	if (end >= label) {
42		label = label;
43		return end - label + 1;
44	}
45	return 0;
46}
47
48static unsigned char *get_buffer(struct blkid_probe *pr,
49			  unsigned off, size_t len)
50{
51	ssize_t		ret_read;
52	unsigned char	*newbuf;
53
54	if (off + len <= SB_BUFFER_SIZE) {
55		if (!pr->sbbuf) {
56			pr->sbbuf = malloc(SB_BUFFER_SIZE);
57			if (!pr->sbbuf)
58				return NULL;
59			if (lseek(pr->fd, 0, SEEK_SET) < 0)
60				return NULL;
61			ret_read = read(pr->fd, pr->sbbuf, SB_BUFFER_SIZE);
62			if (ret_read < 0)
63				ret_read = 0;
64			pr->sb_valid = ret_read;
65		}
66		if (off+len > pr->sb_valid)
67			return NULL;
68		return pr->sbbuf + off;
69	} else {
70		if (len > pr->buf_max) {
71			newbuf = realloc(pr->buf, len);
72			if (newbuf == NULL)
73				return NULL;
74			pr->buf = newbuf;
75			pr->buf_max = len;
76		}
77		if (lseek(pr->fd, off, SEEK_SET) < 0)
78			return NULL;
79		ret_read = read(pr->fd, pr->buf, len);
80		if (ret_read != (ssize_t) len)
81			return NULL;
82		return pr->buf;
83	}
84}
85
86
87/*
88 * This is a special case code to check for an MDRAID device.  We do
89 * this special since it requires checking for a superblock at the end
90 * of the device.
91 */
92static int check_mdraid(int fd, unsigned char *ret_uuid)
93{
94	struct mdp_superblock_s *md;
95	blkid_loff_t		offset;
96	char			buf[4096];
97
98	if (fd < 0)
99		return -BLKID_ERR_PARAM;
100
101	offset = (blkid_get_dev_size(fd) & ~((blkid_loff_t)65535)) - 65536;
102
103	if (blkid_llseek(fd, offset, 0) < 0 ||
104	    read(fd, buf, 4096) != 4096)
105		return -BLKID_ERR_IO;
106
107	/* Check for magic number */
108	if (memcmp("\251+N\374", buf, 4))
109		return -BLKID_ERR_PARAM;
110
111	if (!ret_uuid)
112		return 0;
113	*ret_uuid = 0;
114
115	/* The MD UUID is not contiguous in the superblock, make it so */
116	md = (struct mdp_superblock_s *)buf;
117	if (md->set_uuid0 || md->set_uuid1 || md->set_uuid2 || md->set_uuid3) {
118		memcpy(ret_uuid, &md->set_uuid0, 4);
119		memcpy(ret_uuid, &md->set_uuid1, 12);
120	}
121	return 0;
122}
123
124static void set_uuid(blkid_dev dev, uuid_t uuid, char *tag)
125{
126	char	str[37];
127
128	if (!uuid_is_null(uuid)) {
129		uuid_unparse(uuid, str);
130		blkid_set_tag(dev, tag ? tag : "UUID", str, sizeof(str));
131	}
132}
133
134static void get_ext2_info(blkid_dev dev, unsigned char *buf)
135{
136	struct ext2_super_block *es = (struct ext2_super_block *) buf;
137	const char *label = 0;
138
139	DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",
140		   blkid_le32(es->s_feature_compat),
141		   blkid_le32(es->s_feature_incompat),
142		   blkid_le32(es->s_feature_ro_compat)));
143
144	if (strlen(es->s_volume_name))
145		label = es->s_volume_name;
146	blkid_set_tag(dev, "LABEL", label, sizeof(es->s_volume_name));
147
148	set_uuid(dev, es->s_uuid, 0);
149}
150
151static int probe_ext3(struct blkid_probe *probe,
152		      struct blkid_magic *id __BLKID_ATTR((unused)),
153		      unsigned char *buf)
154{
155	struct ext2_super_block *es;
156	char uuid[37];
157	es = (struct ext2_super_block *)buf;
158
159	/* Distinguish between jbd and ext2/3 fs */
160	if (blkid_le32(es->s_feature_incompat) &
161	    EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
162		return -BLKID_ERR_PARAM;
163
164	/* Distinguish between ext3 and ext2 */
165	if (!(blkid_le32(es->s_feature_compat) &
166	      EXT3_FEATURE_COMPAT_HAS_JOURNAL))
167		return -BLKID_ERR_PARAM;
168
169	get_ext2_info(probe->dev, buf);
170
171	if ((es->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
172	    !uuid_is_null(es->s_journal_uuid))
173		set_uuid(probe->dev, es->s_journal_uuid, "EXT_JOURNAL");
174
175	blkid_set_tag(probe->dev, "SEC_TYPE", "ext2", sizeof("ext2"));
176
177	return 0;
178}
179
180static int probe_ext2(struct blkid_probe *probe,
181		      struct blkid_magic *id __BLKID_ATTR((unused)),
182		      unsigned char *buf)
183{
184	struct ext2_super_block *es;
185
186	es = (struct ext2_super_block *)buf;
187
188	/* Distinguish between jbd and ext2/3 fs */
189	if (blkid_le32(es->s_feature_incompat) &
190	    EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
191		return -BLKID_ERR_PARAM;
192
193	/* Distinguish between ext3 and ext2 */
194	if ((blkid_le32(es->s_feature_compat) &
195	      EXT3_FEATURE_COMPAT_HAS_JOURNAL))
196		return -BLKID_ERR_PARAM;
197
198	get_ext2_info(probe->dev, buf);
199
200	return 0;
201}
202
203static int probe_jbd(struct blkid_probe *probe,
204		     struct blkid_magic *id __BLKID_ATTR((unused)),
205		     unsigned char *buf)
206{
207	struct ext2_super_block *es = (struct ext2_super_block *) buf;
208
209	if (!(blkid_le32(es->s_feature_incompat) &
210	      EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
211		return -BLKID_ERR_PARAM;
212
213	get_ext2_info(probe->dev, buf);
214
215	return 0;
216}
217
218#define FAT_ATTR_VOLUME_ID		0x08
219#define FAT_ATTR_DIR			0x10
220#define FAT_ATTR_LONG_NAME		0x0f
221#define FAT_ATTR_MASK			0x3f
222#define FAT_ENTRY_FREE			0xe5
223
224static char *no_name = "NO NAME    ";
225
226static unsigned char *search_fat_label(struct vfat_dir_entry *dir, int count)
227{
228	unsigned int i;
229
230	for (i = 0; i < count; i++) {
231		if (dir[i].name[0] == 0x00)
232			break;
233
234		if ((dir[i].name[0] == FAT_ENTRY_FREE) ||
235		    (dir[i].cluster_high != 0 || dir[i].cluster_low != 0) ||
236		    ((dir[i].attr & FAT_ATTR_MASK) == FAT_ATTR_LONG_NAME))
237			continue;
238
239		if ((dir[i].attr & (FAT_ATTR_VOLUME_ID | FAT_ATTR_DIR)) ==
240		    FAT_ATTR_VOLUME_ID) {
241			return dir[i].name;
242		}
243	}
244	return 0;
245}
246
247/* FAT label extraction from the root directory taken from Kay
248 * Sievers's volume_id library */
249static int probe_fat(struct blkid_probe *probe,
250		      struct blkid_magic *id __BLKID_ATTR((unused)),
251		      unsigned char *buf)
252{
253	struct vfat_super_block *vs = (struct vfat_super_block *) buf;
254	struct msdos_super_block *ms = (struct msdos_super_block *) buf;
255	struct vfat_dir_entry *dir;
256	char serno[10];
257	const unsigned char *label = 0, *vol_label = 0;
258	unsigned char	*vol_serno;
259	int label_len = 0, maxloop = 100;
260	__u16 sector_size, dir_entries, reserved;
261	__u32 sect_count, fat_size, dir_size, cluster_count, fat_length;
262	__u32 buf_size, start_data_sect, next, root_start, root_dir_entries;
263
264	/* sector size check */
265	sector_size = blkid_le16(*((__u16 *) &ms->ms_sector_size));
266	if (sector_size != 0x200 && sector_size != 0x400 &&
267	    sector_size != 0x800 && sector_size != 0x1000)
268		return 1;
269
270	dir_entries = blkid_le16(*((__u16 *) &ms->ms_dir_entries));
271	reserved =  blkid_le16(ms->ms_reserved);
272	sect_count = blkid_le16(*((__u16 *) &ms->ms_sectors));
273	if (sect_count == 0)
274		sect_count = blkid_le32(ms->ms_total_sect);
275
276	fat_length = blkid_le16(ms->ms_fat_length);
277	if (fat_length == 0)
278		fat_length = blkid_le32(vs->vs_fat32_length);
279
280	fat_size = fat_length * ms->ms_fats;
281	dir_size = ((dir_entries * sizeof(struct vfat_dir_entry)) +
282			(sector_size-1)) / sector_size;
283
284	cluster_count = sect_count - (reserved + fat_size + dir_size);
285	cluster_count /= ms->ms_cluster_size;
286
287	if (cluster_count > FAT32_MAX)
288		return 1;
289
290	if (ms->ms_fat_length) {
291		/* the label may be an attribute in the root directory */
292		root_start = (reserved + fat_size) * sector_size;
293		root_dir_entries = vs->vs_dir_entries[0] +
294			(vs->vs_dir_entries[1] << 8);
295
296		buf_size = root_dir_entries * sizeof(struct vfat_dir_entry);
297		dir = (struct vfat_dir_entry *) get_buffer(probe, root_start,
298							   buf_size);
299		if (dir)
300			vol_label = search_fat_label(dir, root_dir_entries);
301
302		if (!vol_label || !memcmp(vol_label, no_name, 11))
303			vol_label = ms->ms_label;
304		vol_serno = ms->ms_serno;
305
306		blkid_set_tag(probe->dev, "SEC_TYPE", "msdos",
307			      sizeof("msdos"));
308	} else {
309		/* Search the FAT32 root dir for the label attribute */
310		buf_size = vs->vs_cluster_size * sector_size;
311		start_data_sect = reserved + fat_size;
312
313		next = blkid_le32(vs->vs_root_cluster);
314		while (next && --maxloop) {
315			__u32 next_sect_off;
316			__u64 next_off, fat_entry_off;
317			int count;
318
319			next_sect_off = (next - 2) * vs->vs_cluster_size;
320			next_off = (start_data_sect + next_sect_off) *
321				sector_size;
322
323			dir = (struct vfat_dir_entry *)
324				get_buffer(probe, next_off, buf_size);
325			if (dir == NULL)
326				break;
327
328			count = buf_size / sizeof(struct vfat_dir_entry);
329
330			vol_label = search_fat_label(dir, count);
331			if (vol_label)
332				break;
333
334			/* get FAT entry */
335			fat_entry_off = (reserved * sector_size) +
336				(next * sizeof(__u32));
337			buf = get_buffer(probe, fat_entry_off, buf_size);
338			if (buf == NULL)
339				break;
340
341			/* set next cluster */
342			next = blkid_le32(*((__u32 *) buf) & 0x0fffffff);
343		}
344
345		if (!vol_label || !memcmp(vol_label, no_name, 11))
346			vol_label = vs->vs_label;
347		vol_serno = vs->vs_serno;
348	}
349
350	if (vol_label && memcmp(vol_label, no_name, 11)) {
351		label = vol_label;
352		label_len = figure_label_len(vol_label, 11);
353	}
354
355	/* We can't just print them as %04X, because they are unaligned */
356	sprintf(serno, "%02X%02X-%02X%02X", vol_serno[3], vol_serno[2],
357		vol_serno[1], vol_serno[0]);
358
359	blkid_set_tag(probe->dev, "LABEL", (const char *) label, label_len);
360	blkid_set_tag(probe->dev, "UUID", serno, sizeof(serno)-1);
361
362	return 0;
363}
364
365/*
366 * The FAT filesystem could be without a magic string in superblock
367 * (e.g. old floppies).  This heuristic for FAT detection is inspired
368 * by http://vrfy.org/projects/volume_id/ and Linux kernel.
369 * [7-Jul-2005, Karel Zak <kzak@redhat.com>]
370 */
371static int probe_fat_nomagic(struct blkid_probe *probe,
372			     struct blkid_magic *id __BLKID_ATTR((unused)),
373			     unsigned char *buf)
374{
375	struct vfat_super_block *vs;
376
377	vs = (struct vfat_super_block *)buf;
378
379	/* heads check */
380	if (vs->vs_heads == 0)
381		return 1;
382
383	/* cluster size check*/
384	if (vs->vs_cluster_size == 0 ||
385	    (vs->vs_cluster_size & (vs->vs_cluster_size-1)))
386		return 1;
387
388	/* media check */
389	if (vs->vs_media < 0xf8 && vs->vs_media != 0xf0)
390		return 1;
391
392	/* fat counts(Linux kernel expects at least 1 FAT table) */
393	if (!vs->vs_fats)
394		return 1;
395
396	return probe_fat(probe, id, buf);
397}
398
399static int probe_xfs(struct blkid_probe *probe,
400		     struct blkid_magic *id __BLKID_ATTR((unused)),
401		     unsigned char *buf)
402{
403	struct xfs_super_block *xs;
404	const char *label = 0;
405
406	xs = (struct xfs_super_block *)buf;
407
408	if (strlen(xs->xs_fname))
409		label = xs->xs_fname;
410	blkid_set_tag(probe->dev, "LABEL", label, sizeof(xs->xs_fname));
411	set_uuid(probe->dev, xs->xs_uuid, 0);
412	return 0;
413}
414
415static int probe_reiserfs(struct blkid_probe *probe,
416			  struct blkid_magic *id, unsigned char *buf)
417{
418	struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
419	unsigned int blocksize;
420	const char *label = 0;
421
422	blocksize = blkid_le16(rs->rs_blocksize);
423
424	/* If the superblock is inside the journal, we have the wrong one */
425	if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
426		return -BLKID_ERR_BIG;
427
428	/* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
429	if (id->bim_magic[6] == '2' || id->bim_magic[6] == '3') {
430		if (strlen(rs->rs_label))
431			label = rs->rs_label;
432		set_uuid(probe->dev, rs->rs_uuid, 0);
433	}
434	blkid_set_tag(probe->dev, "LABEL", label, sizeof(rs->rs_label));
435
436	return 0;
437}
438
439static int probe_reiserfs4(struct blkid_probe *probe,
440			   struct blkid_magic *id __BLKID_ATTR((unused)),
441			   unsigned char *buf)
442{
443	struct reiser4_super_block *rs4 = (struct reiser4_super_block *) buf;
444	const unsigned char *label = 0;
445
446	if (strlen((char *) rs4->rs4_label))
447		label = rs4->rs4_label;
448	set_uuid(probe->dev, rs4->rs4_uuid, 0);
449	blkid_set_tag(probe->dev, "LABEL", (const char *) label,
450		      sizeof(rs4->rs4_label));
451
452	return 0;
453}
454
455static int probe_jfs(struct blkid_probe *probe,
456		     struct blkid_magic *id __BLKID_ATTR((unused)),
457		     unsigned char *buf)
458{
459	struct jfs_super_block *js;
460	const char *label = 0;
461
462	js = (struct jfs_super_block *)buf;
463
464	if (strlen((char *) js->js_label))
465		label = (char *) js->js_label;
466	blkid_set_tag(probe->dev, "LABEL", label, sizeof(js->js_label));
467	set_uuid(probe->dev, js->js_uuid, 0);
468	return 0;
469}
470
471static int probe_romfs(struct blkid_probe *probe,
472		       struct blkid_magic *id __BLKID_ATTR((unused)),
473		       unsigned char *buf)
474{
475	struct romfs_super_block *ros;
476	const char *label = 0;
477
478	ros = (struct romfs_super_block *)buf;
479
480	if (strlen((char *) ros->ros_volume))
481		label = (char *) ros->ros_volume;
482	blkid_set_tag(probe->dev, "LABEL", label, 0);
483	return 0;
484}
485
486static int probe_cramfs(struct blkid_probe *probe,
487			struct blkid_magic *id __BLKID_ATTR((unused)),
488			unsigned char *buf)
489{
490	struct cramfs_super_block *csb;
491	const char *label = 0;
492
493	csb = (struct cramfs_super_block *)buf;
494
495	if (strlen((char *) csb->name))
496		label = (char *) csb->name;
497	blkid_set_tag(probe->dev, "LABEL", label, 0);
498	return 0;
499}
500
501static int probe_swap0(struct blkid_probe *probe,
502		       struct blkid_magic *id __BLKID_ATTR((unused)),
503		       unsigned char *buf __BLKID_ATTR((unused)))
504{
505	blkid_set_tag(probe->dev, "UUID", 0, 0);
506	blkid_set_tag(probe->dev, "LABEL", 0, 0);
507	return 0;
508}
509
510static int probe_swap1(struct blkid_probe *probe,
511		       struct blkid_magic *id __BLKID_ATTR((unused)),
512		       unsigned char *buf __BLKID_ATTR((unused)))
513{
514	struct swap_id_block *sws;
515
516	probe_swap0(probe, id, buf);
517	/*
518	 * Version 1 swap headers are always located at offset of 1024
519	 * bytes, although the swap signature itself is located at the
520	 * end of the page (which may vary depending on hardware
521	 * pagesize).
522	 */
523	sws = (struct swap_id_block *) get_buffer(probe, 1024, 1024);
524	if (!sws)
525		return 1;
526
527	/* arbitrary sanity check.. is there any garbage down there? */
528	if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0)  {
529		if (sws->sws_volume[0])
530			blkid_set_tag(probe->dev, "LABEL", sws->sws_volume,
531				      sizeof(sws->sws_volume));
532		if (sws->sws_uuid[0])
533			set_uuid(probe->dev, sws->sws_uuid, 0);
534	}
535	return 0;
536}
537
538static int probe_iso9660(struct blkid_probe *probe,
539			 struct blkid_magic *id __BLKID_ATTR((unused)),
540			 unsigned char *buf)
541{
542	struct iso_volume_descriptor *iso;
543	const unsigned char *label;
544
545	iso = (struct iso_volume_descriptor *) buf;
546	label = iso->volume_id;
547
548	blkid_set_tag(probe->dev, "LABEL", (const char *) label,
549		      figure_label_len(label, 32));
550	return 0;
551}
552
553
554static const char
555*udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
556		 "NSR03", "TEA01", 0 };
557
558static int probe_udf(struct blkid_probe *probe,
559		     struct blkid_magic *id __BLKID_ATTR((unused)),
560		     unsigned char *buf __BLKID_ATTR((unused)))
561{
562	int j, bs;
563	struct iso_volume_descriptor *isosb;
564	const char ** m;
565
566	/* determine the block size by scanning in 2K increments
567	   (block sizes larger than 2K will be null padded) */
568	for (bs = 1; bs < 16; bs++) {
569		isosb = (struct iso_volume_descriptor *)
570			get_buffer(probe, bs*2048+32768, sizeof(isosb));
571		if (!isosb)
572			return 1;
573		if (isosb->vd_id[0])
574			break;
575	}
576
577	/* Scan up to another 64 blocks looking for additional VSD's */
578	for (j = 1; j < 64; j++) {
579		if (j > 1) {
580			isosb = (struct iso_volume_descriptor *)
581				get_buffer(probe, j*bs*2048+32768,
582					   sizeof(isosb));
583			if (!isosb)
584				return 1;
585		}
586		/* If we find NSR0x then call it udf:
587		   NSR01 for UDF 1.00
588		   NSR02 for UDF 1.50
589		   NSR03 for UDF 2.00 */
590		if (!strncmp(isosb->vd_id, "NSR0", 4))
591			return 0;
592		for (m = udf_magic; *m; m++)
593			if (!strncmp(*m, isosb->vd_id, 5))
594				break;
595		if (*m == 0)
596			return 1;
597	}
598	return 1;
599}
600
601static int probe_ocfs(struct blkid_probe *probe,
602		      struct blkid_magic *id __BLKID_ATTR((unused)),
603		      unsigned char *buf)
604{
605	struct ocfs_volume_header ovh;
606	struct ocfs_volume_label ovl;
607	__u32 major;
608
609	memcpy(&ovh, buf, sizeof(ovh));
610	memcpy(&ovl, buf+512, sizeof(ovl));
611
612	major = ocfsmajor(ovh);
613	if (major == 1)
614		blkid_set_tag(probe->dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
615	else if (major >= 9)
616		blkid_set_tag(probe->dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
617
618	blkid_set_tag(probe->dev, "LABEL", ovl.label, ocfslabellen(ovl));
619	blkid_set_tag(probe->dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
620	set_uuid(probe->dev, ovl.vol_id, 0);
621	return 0;
622}
623
624static int probe_ocfs2(struct blkid_probe *probe,
625		       struct blkid_magic *id __BLKID_ATTR((unused)),
626		       unsigned char *buf)
627{
628	struct ocfs2_super_block *osb;
629
630	osb = (struct ocfs2_super_block *)buf;
631
632	blkid_set_tag(probe->dev, "LABEL", osb->s_label, sizeof(osb->s_label));
633	set_uuid(probe->dev, osb->s_uuid, 0);
634	return 0;
635}
636
637static int probe_oracleasm(struct blkid_probe *probe,
638			   struct blkid_magic *id __BLKID_ATTR((unused)),
639			   unsigned char *buf)
640{
641	struct oracle_asm_disk_label *dl;
642
643	dl = (struct oracle_asm_disk_label *)buf;
644
645	blkid_set_tag(probe->dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
646	return 0;
647}
648
649/*
650 * BLKID_BLK_OFFS is at least as large as the highest bim_kboff defined
651 * in the type_array table below + bim_kbalign.
652 *
653 * When probing for a lot of magics, we handle everything in 1kB buffers so
654 * that we don't have to worry about reading each combination of block sizes.
655 */
656#define BLKID_BLK_OFFS	64	/* currently reiserfs */
657
658/*
659 * Various filesystem magics that we can check for.  Note that kboff and
660 * sboff are in kilobytes and bytes respectively.  All magics are in
661 * byte strings so we don't worry about endian issues.
662 */
663static struct blkid_magic type_array[] = {
664/*  type     kboff   sboff len  magic			probe */
665  { "oracleasm", 0,	32,  8, "ORCLDISK",		probe_oracleasm },
666  { "ntfs",      0,      3,  8, "NTFS    ",             0 },
667  { "jbd",	 1,   0x38,  2, "\123\357",		probe_jbd },
668  { "ext3",	 1,   0x38,  2, "\123\357",		probe_ext3 },
669  { "ext2",	 1,   0x38,  2, "\123\357",		probe_ext2 },
670  { "reiserfs",	 8,   0x34,  8, "ReIsErFs",		probe_reiserfs },
671  { "reiserfs", 64,   0x34,  9, "ReIsEr2Fs",		probe_reiserfs },
672  { "reiserfs", 64,   0x34,  9, "ReIsEr3Fs",		probe_reiserfs },
673  { "reiserfs", 64,   0x34,  8, "ReIsErFs",		probe_reiserfs },
674  { "reiserfs",	 8,	20,  8, "ReIsErFs",		probe_reiserfs },
675  { "reiser4",  64,	 0,  7, "ReIsEr4",		probe_reiserfs4 },
676  { "vfat",      0,   0x52,  5, "MSWIN",                probe_fat },
677  { "vfat",      0,   0x52,  8, "FAT32   ",             probe_fat },
678  { "vfat",      0,   0x36,  5, "MSDOS",                probe_fat },
679  { "vfat",      0,   0x36,  8, "FAT16   ",             probe_fat },
680  { "vfat",      0,   0x36,  8, "FAT12   ",             probe_fat },
681  { "vfat",      0,      0,  2, "\353\220",             probe_fat_nomagic },
682  { "vfat",      0,      0,  1, "\351",                 probe_fat_nomagic },
683  { "minix",     1,   0x10,  2, "\177\023",             0 },
684  { "minix",     1,   0x10,  2, "\217\023",             0 },
685  { "minix",	 1,   0x10,  2, "\150\044",		0 },
686  { "minix",	 1,   0x10,  2, "\170\044",		0 },
687  { "vxfs",	 1,	 0,  4, "\365\374\001\245",	0 },
688  { "xfs",	 0,	 0,  4, "XFSB",			probe_xfs },
689  { "romfs",	 0,	 0,  8, "-rom1fs-",		probe_romfs },
690  { "bfs",	 0,	 0,  4, "\316\372\173\033",	0 },
691  { "cramfs",	 0,	 0,  4, "E=\315\050",		probe_cramfs },
692  { "qnx4",	 0,	 4,  6, "QNX4FS",		0 },
693  { "udf",	32,	 1,  5, "BEA01",		probe_udf },
694  { "udf",	32,	 1,  5, "BOOT2",		probe_udf },
695  { "udf",	32,	 1,  5, "CD001",		probe_udf },
696  { "udf",	32,	 1,  5, "CDW02",		probe_udf },
697  { "udf",	32,	 1,  5, "NSR02",		probe_udf },
698  { "udf",	32,	 1,  5, "NSR03",		probe_udf },
699  { "udf",	32,	 1,  5, "TEA01",		probe_udf },
700  { "iso9660",	32,	 1,  5, "CD001",		probe_iso9660 },
701  { "iso9660",	32,	 9,  5, "CDROM",		probe_iso9660 },
702  { "jfs",	32,	 0,  4, "JFS1",			probe_jfs },
703  { "hfs",	 1,	 0,  2, "BD",			0 },
704  { "ufs",	 8,  0x55c,  4, "T\031\001\000",	0 },
705  { "hpfs",	 8,	 0,  4, "I\350\225\371",	0 },
706  { "sysv",	 0,  0x3f8,  4, "\020~\030\375",	0 },
707  { "swap",	 0,  0xff6, 10, "SWAP-SPACE",		probe_swap0 },
708  { "swap",	 0,  0xff6, 10, "SWAPSPACE2",		probe_swap1 },
709  { "swsuspend", 0,  0xff6,  9, "S1SUSPEND",		probe_swap1 },
710  { "swsuspend", 0,  0xff6,  9, "S2SUSPEND",		probe_swap1 },
711  { "swap",	 0, 0x1ff6, 10, "SWAP-SPACE",		probe_swap0 },
712  { "swap",	 0, 0x1ff6, 10, "SWAPSPACE2",		probe_swap1 },
713  { "swsuspend", 0, 0x1ff6,  9, "S1SUSPEND",		probe_swap1 },
714  { "swsuspend", 0, 0x1ff6,  9, "S2SUSPEND",		probe_swap1 },
715  { "swap",	 0, 0x3ff6, 10, "SWAP-SPACE",		probe_swap0 },
716  { "swap",	 0, 0x3ff6, 10, "SWAPSPACE2",		probe_swap1 },
717  { "swsuspend", 0, 0x3ff6,  9, "S1SUSPEND",		probe_swap1 },
718  { "swsuspend", 0, 0x3ff6,  9, "S2SUSPEND",		probe_swap1 },
719  { "swap",	 0, 0x7ff6, 10, "SWAP-SPACE",		probe_swap0 },
720  { "swap",	 0, 0x7ff6, 10, "SWAPSPACE2",		probe_swap1 },
721  { "swsuspend", 0, 0x7ff6,  9, "S1SUSPEND",		probe_swap1 },
722  { "swsuspend", 0, 0x7ff6,  9, "S2SUSPEND",		probe_swap1 },
723  { "swap",	 0, 0xfff6, 10, "SWAP-SPACE",		probe_swap0 },
724  { "swap",	 0, 0xfff6, 10, "SWAPSPACE2",		probe_swap1 },
725  { "swsuspend", 0, 0xfff6,  9, "S1SUSPEND",		probe_swap1 },
726  { "swsuspend", 0, 0xfff6,  9, "S2SUSPEND",		probe_swap1 },
727  { "ocfs",	 0,	 8,  9,	"OracleCFS",		probe_ocfs },
728  { "ocfs2",	 1,	 0,  6,	"OCFSV2",		probe_ocfs2 },
729  { "ocfs2",	 2,	 0,  6,	"OCFSV2",		probe_ocfs2 },
730  { "ocfs2",	 4,	 0,  6,	"OCFSV2",		probe_ocfs2 },
731  { "ocfs2",	 8,	 0,  6,	"OCFSV2",		probe_ocfs2 },
732  {   NULL,	 0,	 0,  0, NULL,			NULL }
733};
734
735/*
736 * Verify that the data in dev is consistent with what is on the actual
737 * block device (using the devname field only).  Normally this will be
738 * called when finding items in the cache, but for long running processes
739 * is also desirable to revalidate an item before use.
740 *
741 * If we are unable to revalidate the data, we return the old data and
742 * do not set the BLKID_BID_FL_VERIFIED flag on it.
743 */
744blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
745{
746	struct blkid_magic *id;
747	struct blkid_probe probe;
748	blkid_tag_iterate iter;
749	unsigned char *buf;
750	const char *type, *value;
751	struct stat st;
752	time_t diff, now;
753	int idx;
754
755	if (!dev)
756		return NULL;
757
758	now = time(0);
759	diff = now - dev->bid_time;
760
761	if ((now > dev->bid_time) && (diff > 0) &&
762	    ((diff < BLKID_PROBE_MIN) ||
763	     (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
764	      diff < BLKID_PROBE_INTERVAL)))
765		return dev;
766
767	DBG(DEBUG_PROBE,
768	    printf("need to revalidate %s (time since last check %lu)\n",
769		   dev->bid_name, diff));
770
771	if (((probe.fd = open(dev->bid_name, O_RDONLY)) < 0) ||
772	    (fstat(probe.fd, &st) < 0)) {
773		if (probe.fd >= 0) close(probe.fd);
774		if (errno == ENXIO || errno == ENODEV || errno == ENOENT) {
775			blkid_free_dev(dev);
776			return NULL;
777		}
778		/* We don't have read permission, just return cache data. */
779		DBG(DEBUG_PROBE,
780		    printf("returning unverified data for %s\n",
781			   dev->bid_name));
782		return dev;
783	}
784
785	probe.cache = cache;
786	probe.dev = dev;
787	probe.sbbuf = 0;
788	probe.buf = 0;
789	probe.buf_max = 0;
790
791	/*
792	 * Iterate over the type array.  If we already know the type,
793	 * then try that first.  If it doesn't work, then blow away
794	 * the type information, and try again.
795	 *
796	 */
797try_again:
798	type = 0;
799	if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
800		uuid_t	uuid;
801
802		if (check_mdraid(probe.fd, uuid) == 0) {
803			set_uuid(dev, uuid, 0);
804			type = "mdraid";
805			goto found_type;
806		}
807	}
808	for (id = type_array; id->bim_type; id++) {
809		if (dev->bid_type &&
810		    strcmp(id->bim_type, dev->bid_type))
811			continue;
812
813		idx = id->bim_kboff + (id->bim_sboff >> 10);
814		buf = get_buffer(&probe, idx << 10, 1024);
815		if (!buf)
816			continue;
817
818		if (memcmp(id->bim_magic, buf + (id->bim_sboff&0x3ff),
819			   id->bim_len))
820			continue;
821
822		if ((id->bim_probe == NULL) ||
823		    (id->bim_probe(&probe, id, buf) == 0)) {
824			type = id->bim_type;
825			goto found_type;
826		}
827	}
828
829	if (!id->bim_type && dev->bid_type) {
830		/*
831		 * Zap the device filesystem information and try again
832		 */
833		iter = blkid_tag_iterate_begin(dev);
834		while (blkid_tag_next(iter, &type, &value) == 0)
835			blkid_set_tag(dev, type, 0, 0);
836		blkid_tag_iterate_end(iter);
837		goto try_again;
838	}
839
840	if (!dev->bid_type) {
841		if (probe.fd >= 0) close(probe.fd);
842		blkid_free_dev(dev);
843		return NULL;
844	}
845
846found_type:
847	if (dev && type) {
848		dev->bid_devno = st.st_rdev;
849		dev->bid_time = time(0);
850		dev->bid_flags |= BLKID_BID_FL_VERIFIED;
851		cache->bic_flags |= BLKID_BIC_FL_CHANGED;
852
853		blkid_set_tag(dev, "TYPE", type, 0);
854
855		DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
856			   dev->bid_name, st.st_rdev, type));
857	}
858
859	if (probe.sbbuf)
860		free(probe.sbbuf);
861	if (probe.buf)
862		free(probe.buf);
863	close(probe.fd);
864
865	return dev;
866}
867
868int blkid_known_fstype(const char *fstype)
869{
870	struct blkid_magic *id;
871
872	for (id = type_array; id->bim_type; id++) {
873		if (strcmp(fstype, id->bim_type) == 0)
874			return 1;
875	}
876	return 0;
877}
878
879#ifdef TEST_PROGRAM
880int main(int argc, char **argv)
881{
882	blkid_dev dev;
883	blkid_cache cache;
884	int ret;
885
886	if (argc != 2) {
887		fprintf(stderr, "Usage: %s device\n"
888			"Probe a single device to determine type\n", argv[0]);
889		exit(1);
890	}
891	if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
892		fprintf(stderr, "%s: error creating cache (%d)\n",
893			argv[0], ret);
894		exit(1);
895	}
896	dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
897	if (!dev) {
898		printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
899		return (1);
900	}
901	printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");
902	if (dev->bid_label)
903		printf("LABEL='%s'\n", dev->bid_label);
904	if (dev->bid_uuid)
905		printf("UUID='%s'\n", dev->bid_uuid);
906
907	blkid_free_dev(dev);
908	return (0);
909}
910#endif
911