probe.c revision cb0c5d701a8852f72fe75c9bd223643fb5222399
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			  blkid_loff_t 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 (blkid_llseek(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) && memcmp("\374N+\251", 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 + 4, &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	es = (struct ext2_super_block *)buf;
157
158	/* Distinguish between jbd and ext2/3 fs */
159	if (blkid_le32(es->s_feature_incompat) &
160	    EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
161		return -BLKID_ERR_PARAM;
162
163	/* Distinguish between ext3 and ext2 */
164	if (!(blkid_le32(es->s_feature_compat) &
165	      EXT3_FEATURE_COMPAT_HAS_JOURNAL))
166		return -BLKID_ERR_PARAM;
167
168	get_ext2_info(probe->dev, buf);
169
170	if ((es->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
171	    !uuid_is_null(es->s_journal_uuid))
172		set_uuid(probe->dev, es->s_journal_uuid, "EXT_JOURNAL");
173
174	blkid_set_tag(probe->dev, "SEC_TYPE", "ext2", sizeof("ext2"));
175
176	return 0;
177}
178
179static int probe_ext2(struct blkid_probe *probe,
180		      struct blkid_magic *id __BLKID_ATTR((unused)),
181		      unsigned char *buf)
182{
183	struct ext2_super_block *es;
184
185	es = (struct ext2_super_block *)buf;
186
187	/* Distinguish between jbd and ext2/3 fs */
188	if (blkid_le32(es->s_feature_incompat) &
189	    EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
190		return -BLKID_ERR_PARAM;
191
192	/* Distinguish between ext3 and ext2 */
193	if ((blkid_le32(es->s_feature_compat) &
194	      EXT3_FEATURE_COMPAT_HAS_JOURNAL))
195		return -BLKID_ERR_PARAM;
196
197	get_ext2_info(probe->dev, buf);
198
199	return 0;
200}
201
202static int probe_jbd(struct blkid_probe *probe,
203		     struct blkid_magic *id __BLKID_ATTR((unused)),
204		     unsigned char *buf)
205{
206	struct ext2_super_block *es = (struct ext2_super_block *) buf;
207
208	if (!(blkid_le32(es->s_feature_incompat) &
209	      EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
210		return -BLKID_ERR_PARAM;
211
212	get_ext2_info(probe->dev, buf);
213
214	return 0;
215}
216
217#define FAT_ATTR_VOLUME_ID		0x08
218#define FAT_ATTR_DIR			0x10
219#define FAT_ATTR_LONG_NAME		0x0f
220#define FAT_ATTR_MASK			0x3f
221#define FAT_ENTRY_FREE			0xe5
222
223static char *no_name = "NO NAME    ";
224
225static unsigned char *search_fat_label(struct vfat_dir_entry *dir, int count)
226{
227	int i;
228
229	for (i = 0; i < count; i++) {
230		if (dir[i].name[0] == 0x00)
231			break;
232
233		if ((dir[i].name[0] == FAT_ENTRY_FREE) ||
234		    (dir[i].cluster_high != 0 || dir[i].cluster_low != 0) ||
235		    ((dir[i].attr & FAT_ATTR_MASK) == FAT_ATTR_LONG_NAME))
236			continue;
237
238		if ((dir[i].attr & (FAT_ATTR_VOLUME_ID | FAT_ATTR_DIR)) ==
239		    FAT_ATTR_VOLUME_ID) {
240			return dir[i].name;
241		}
242	}
243	return 0;
244}
245
246/* FAT label extraction from the root directory taken from Kay
247 * Sievers's volume_id library */
248static int probe_fat(struct blkid_probe *probe,
249		      struct blkid_magic *id __BLKID_ATTR((unused)),
250		      unsigned char *buf)
251{
252	struct vfat_super_block *vs = (struct vfat_super_block *) buf;
253	struct msdos_super_block *ms = (struct msdos_super_block *) buf;
254	struct vfat_dir_entry *dir;
255	char serno[10];
256	const unsigned char *label = 0, *vol_label = 0, *tmp;
257	unsigned char	*vol_serno;
258	int label_len = 0, maxloop = 100;
259	__u16 sector_size, dir_entries, reserved;
260	__u32 sect_count, fat_size, dir_size, cluster_count, fat_length;
261	__u32 buf_size, start_data_sect, next, root_start, root_dir_entries;
262
263	/* sector size check */
264	tmp = (unsigned char *)&ms->ms_sector_size;
265	sector_size = tmp[0] + (tmp[1] << 8);
266	if (sector_size != 0x200 && sector_size != 0x400 &&
267	    sector_size != 0x800 && sector_size != 0x1000)
268		return 1;
269
270	tmp = (unsigned char *)&ms->ms_dir_entries;
271	dir_entries = tmp[0] + (tmp[1] << 8);
272	reserved =  blkid_le16(ms->ms_reserved);
273	tmp = (unsigned char *)&ms->ms_sectors;
274	sect_count = tmp[0] + (tmp[1] << 8);
275	if (sect_count == 0)
276		sect_count = blkid_le32(ms->ms_total_sect);
277
278	fat_length = blkid_le16(ms->ms_fat_length);
279	if (fat_length == 0)
280		fat_length = blkid_le32(vs->vs_fat32_length);
281
282	fat_size = fat_length * ms->ms_fats;
283	dir_size = ((dir_entries * sizeof(struct vfat_dir_entry)) +
284			(sector_size-1)) / sector_size;
285
286	cluster_count = sect_count - (reserved + fat_size + dir_size);
287	cluster_count /= ms->ms_cluster_size;
288
289	if (cluster_count > FAT32_MAX)
290		return 1;
291
292	if (ms->ms_fat_length) {
293		/* the label may be an attribute in the root directory */
294		root_start = (reserved + fat_size) * sector_size;
295		root_dir_entries = vs->vs_dir_entries[0] +
296			(vs->vs_dir_entries[1] << 8);
297
298		buf_size = root_dir_entries * sizeof(struct vfat_dir_entry);
299		dir = (struct vfat_dir_entry *) get_buffer(probe, root_start,
300							   buf_size);
301		if (dir)
302			vol_label = search_fat_label(dir, root_dir_entries);
303
304		if (!vol_label || !memcmp(vol_label, no_name, 11))
305			vol_label = ms->ms_label;
306		vol_serno = ms->ms_serno;
307
308		blkid_set_tag(probe->dev, "SEC_TYPE", "msdos",
309			      sizeof("msdos"));
310	} else {
311		/* Search the FAT32 root dir for the label attribute */
312		buf_size = vs->vs_cluster_size * sector_size;
313		start_data_sect = reserved + fat_size;
314
315		next = blkid_le32(vs->vs_root_cluster);
316		while (next && --maxloop) {
317			__u32 next_sect_off;
318			__u64 next_off, fat_entry_off;
319			int count;
320
321			next_sect_off = (next - 2) * vs->vs_cluster_size;
322			next_off = (start_data_sect + next_sect_off) *
323				sector_size;
324
325			dir = (struct vfat_dir_entry *)
326				get_buffer(probe, next_off, buf_size);
327			if (dir == NULL)
328				break;
329
330			count = buf_size / sizeof(struct vfat_dir_entry);
331
332			vol_label = search_fat_label(dir, count);
333			if (vol_label)
334				break;
335
336			/* get FAT entry */
337			fat_entry_off = (reserved * sector_size) +
338				(next * sizeof(__u32));
339			buf = get_buffer(probe, fat_entry_off, buf_size);
340			if (buf == NULL)
341				break;
342
343			/* set next cluster */
344			next = blkid_le32(*((__u32 *) buf) & 0x0fffffff);
345		}
346
347		if (!vol_label || !memcmp(vol_label, no_name, 11))
348			vol_label = vs->vs_label;
349		vol_serno = vs->vs_serno;
350	}
351
352	if (vol_label && memcmp(vol_label, no_name, 11)) {
353		if ((label_len = figure_label_len(vol_label, 11)))
354			label = vol_label;
355	}
356
357	/* We can't just print them as %04X, because they are unaligned */
358	sprintf(serno, "%02X%02X-%02X%02X", vol_serno[3], vol_serno[2],
359		vol_serno[1], vol_serno[0]);
360
361	blkid_set_tag(probe->dev, "LABEL", (const char *) label, label_len);
362	blkid_set_tag(probe->dev, "UUID", serno, sizeof(serno)-1);
363
364	return 0;
365}
366
367/*
368 * The FAT filesystem could be without a magic string in superblock
369 * (e.g. old floppies).  This heuristic for FAT detection is inspired
370 * by http://vrfy.org/projects/volume_id/ and Linux kernel.
371 * [7-Jul-2005, Karel Zak <kzak@redhat.com>]
372 */
373static int probe_fat_nomagic(struct blkid_probe *probe,
374			     struct blkid_magic *id __BLKID_ATTR((unused)),
375			     unsigned char *buf)
376{
377	struct vfat_super_block *vs;
378
379	vs = (struct vfat_super_block *)buf;
380
381	/* heads check */
382	if (vs->vs_heads == 0)
383		return 1;
384
385	/* cluster size check*/
386	if (vs->vs_cluster_size == 0 ||
387	    (vs->vs_cluster_size & (vs->vs_cluster_size-1)))
388		return 1;
389
390	/* media check */
391	if (vs->vs_media < 0xf8 && vs->vs_media != 0xf0)
392		return 1;
393
394	/* fat counts(Linux kernel expects at least 1 FAT table) */
395	if (!vs->vs_fats)
396		return 1;
397
398	return probe_fat(probe, id, buf);
399}
400
401static int probe_ntfs(struct blkid_probe *probe,
402		      struct blkid_magic *id __BLKID_ATTR((unused)),
403		      unsigned char *buf)
404{
405	struct ntfs_super_block *ns;
406	struct master_file_table_record *mft;
407	struct file_attribute *attr;
408	char		uuid_str[17], label_str[129], *cp;
409	int		bytes_per_sector, sectors_per_cluster;
410	int		mft_record_size, attr_off, attr_len;
411	unsigned int	i, attr_type, val_len;
412	int		val_off;
413	__u64		nr_clusters;
414	blkid_loff_t off;
415	unsigned char *buf_mft, *val;
416
417	ns = (struct ntfs_super_block *) buf;
418
419	bytes_per_sector = ns->bios_parameter_block[0] +
420		(ns->bios_parameter_block[1]  << 8);
421	sectors_per_cluster = ns->bios_parameter_block[2];
422
423	if (ns->cluster_per_mft_record < 0)
424		mft_record_size = 1 << - ns->cluster_per_mft_record;
425	else
426		mft_record_size = ns->cluster_per_mft_record *
427			sectors_per_cluster * bytes_per_sector;
428	nr_clusters = blkid_le64(ns->number_of_sectors) / sectors_per_cluster;
429
430	if ((blkid_le64(ns->mft_cluster_location) > nr_clusters) ||
431	    (blkid_le64(ns->mft_mirror_cluster_location) > nr_clusters))
432		return 1;
433
434	off = blkid_le64(ns->mft_mirror_cluster_location) *
435		bytes_per_sector * sectors_per_cluster;
436
437	buf_mft = get_buffer(probe, off, mft_record_size);
438	if (!buf_mft)
439		return 1;
440
441	if (memcmp(buf_mft, "FILE", 4))
442		return 1;
443
444	off = blkid_le64(ns->mft_cluster_location) * bytes_per_sector *
445		sectors_per_cluster;
446
447	buf_mft = get_buffer(probe, off, mft_record_size);
448	if (!buf_mft)
449		return 1;
450
451	if (memcmp(buf_mft, "FILE", 4))
452		return 1;
453
454	off += MFT_RECORD_VOLUME * mft_record_size;
455
456	buf_mft = get_buffer(probe, off, mft_record_size);
457	if (!buf_mft)
458		return 1;
459
460	if (memcmp(buf_mft, "FILE", 4))
461		return 1;
462
463	mft = (struct master_file_table_record *) buf_mft;
464
465	attr_off = blkid_le16(mft->attrs_offset);
466	label_str[0] = 0;
467
468	while (1) {
469		attr = (struct file_attribute *) (buf_mft + attr_off);
470		attr_len = blkid_le16(attr->len);
471		attr_type = blkid_le32(attr->type);
472		val_off = blkid_le16(attr->value_offset);
473		val_len = blkid_le32(attr->value_len);
474
475		attr_off += attr_len;
476
477		if ((attr_off > mft_record_size) ||
478		    (attr_len == 0))
479			break;
480
481		if (attr_type == MFT_RECORD_ATTR_END)
482			break;
483
484		if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
485			if (val_len > sizeof(label_str))
486				val_len = sizeof(label_str)-1;
487
488			for (i=0, cp=label_str; i < val_len; i+=2,cp++) {
489				val = ((__u8 *) attr) + val_off + i;
490				*cp = val[0];
491				if (val[1])
492					*cp = '?';
493			}
494			*cp = 0;
495		}
496	}
497
498	sprintf(uuid_str, "%llX", blkid_le64(ns->volume_serial));
499	blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
500	if (label_str[0])
501		blkid_set_tag(probe->dev, "LABEL", label_str, 0);
502	return 0;
503}
504
505
506static int probe_xfs(struct blkid_probe *probe,
507		     struct blkid_magic *id __BLKID_ATTR((unused)),
508		     unsigned char *buf)
509{
510	struct xfs_super_block *xs;
511	const char *label = 0;
512
513	xs = (struct xfs_super_block *)buf;
514
515	if (strlen(xs->xs_fname))
516		label = xs->xs_fname;
517	blkid_set_tag(probe->dev, "LABEL", label, sizeof(xs->xs_fname));
518	set_uuid(probe->dev, xs->xs_uuid, 0);
519	return 0;
520}
521
522static int probe_reiserfs(struct blkid_probe *probe,
523			  struct blkid_magic *id, unsigned char *buf)
524{
525	struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
526	unsigned int blocksize;
527	const char *label = 0;
528
529	blocksize = blkid_le16(rs->rs_blocksize);
530
531	/* If the superblock is inside the journal, we have the wrong one */
532	if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
533		return -BLKID_ERR_BIG;
534
535	/* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
536	if (id->bim_magic[6] == '2' || id->bim_magic[6] == '3') {
537		if (strlen(rs->rs_label))
538			label = rs->rs_label;
539		set_uuid(probe->dev, rs->rs_uuid, 0);
540	}
541	blkid_set_tag(probe->dev, "LABEL", label, sizeof(rs->rs_label));
542
543	return 0;
544}
545
546static int probe_reiserfs4(struct blkid_probe *probe,
547			   struct blkid_magic *id __BLKID_ATTR((unused)),
548			   unsigned char *buf)
549{
550	struct reiser4_super_block *rs4 = (struct reiser4_super_block *) buf;
551	const unsigned char *label = 0;
552
553	if (strlen((char *) rs4->rs4_label))
554		label = rs4->rs4_label;
555	set_uuid(probe->dev, rs4->rs4_uuid, 0);
556	blkid_set_tag(probe->dev, "LABEL", (const char *) label,
557		      sizeof(rs4->rs4_label));
558
559	return 0;
560}
561
562static int probe_jfs(struct blkid_probe *probe,
563		     struct blkid_magic *id __BLKID_ATTR((unused)),
564		     unsigned char *buf)
565{
566	struct jfs_super_block *js;
567	const char *label = 0;
568
569	js = (struct jfs_super_block *)buf;
570
571	if (strlen((char *) js->js_label))
572		label = (char *) js->js_label;
573	blkid_set_tag(probe->dev, "LABEL", label, sizeof(js->js_label));
574	set_uuid(probe->dev, js->js_uuid, 0);
575	return 0;
576}
577
578static int probe_romfs(struct blkid_probe *probe,
579		       struct blkid_magic *id __BLKID_ATTR((unused)),
580		       unsigned char *buf)
581{
582	struct romfs_super_block *ros;
583	const char *label = 0;
584
585	ros = (struct romfs_super_block *)buf;
586
587	if (strlen((char *) ros->ros_volume))
588		label = (char *) ros->ros_volume;
589	blkid_set_tag(probe->dev, "LABEL", label, 0);
590	return 0;
591}
592
593static int probe_cramfs(struct blkid_probe *probe,
594			struct blkid_magic *id __BLKID_ATTR((unused)),
595			unsigned char *buf)
596{
597	struct cramfs_super_block *csb;
598	const char *label = 0;
599
600	csb = (struct cramfs_super_block *)buf;
601
602	if (strlen((char *) csb->name))
603		label = (char *) csb->name;
604	blkid_set_tag(probe->dev, "LABEL", label, 0);
605	return 0;
606}
607
608static int probe_swap0(struct blkid_probe *probe,
609		       struct blkid_magic *id __BLKID_ATTR((unused)),
610		       unsigned char *buf __BLKID_ATTR((unused)))
611{
612	blkid_set_tag(probe->dev, "UUID", 0, 0);
613	blkid_set_tag(probe->dev, "LABEL", 0, 0);
614	return 0;
615}
616
617static int probe_swap1(struct blkid_probe *probe,
618		       struct blkid_magic *id __BLKID_ATTR((unused)),
619		       unsigned char *buf __BLKID_ATTR((unused)))
620{
621	struct swap_id_block *sws;
622
623	probe_swap0(probe, id, buf);
624	/*
625	 * Version 1 swap headers are always located at offset of 1024
626	 * bytes, although the swap signature itself is located at the
627	 * end of the page (which may vary depending on hardware
628	 * pagesize).
629	 */
630	sws = (struct swap_id_block *) get_buffer(probe, 1024, 1024);
631	if (!sws)
632		return 1;
633
634	/* arbitrary sanity check.. is there any garbage down there? */
635	if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0)  {
636		if (sws->sws_volume[0])
637			blkid_set_tag(probe->dev, "LABEL", sws->sws_volume,
638				      sizeof(sws->sws_volume));
639		if (sws->sws_uuid[0])
640			set_uuid(probe->dev, sws->sws_uuid, 0);
641	}
642	return 0;
643}
644
645static int probe_iso9660(struct blkid_probe *probe,
646			 struct blkid_magic *id __BLKID_ATTR((unused)),
647			 unsigned char *buf)
648{
649	struct iso_volume_descriptor *iso;
650	const unsigned char *label;
651
652	iso = (struct iso_volume_descriptor *) buf;
653	label = iso->volume_id;
654
655	blkid_set_tag(probe->dev, "LABEL", (const char *) label,
656		      figure_label_len(label, 32));
657	return 0;
658}
659
660
661static const char
662*udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
663		 "NSR03", "TEA01", 0 };
664
665static int probe_udf(struct blkid_probe *probe,
666		     struct blkid_magic *id __BLKID_ATTR((unused)),
667		     unsigned char *buf __BLKID_ATTR((unused)))
668{
669	int j, bs;
670	struct iso_volume_descriptor *isosb;
671	const char ** m;
672
673	/* determine the block size by scanning in 2K increments
674	   (block sizes larger than 2K will be null padded) */
675	for (bs = 1; bs < 16; bs++) {
676		isosb = (struct iso_volume_descriptor *)
677			get_buffer(probe, bs*2048+32768, sizeof(isosb));
678		if (!isosb)
679			return 1;
680		if (isosb->vd_id[0])
681			break;
682	}
683
684	/* Scan up to another 64 blocks looking for additional VSD's */
685	for (j = 1; j < 64; j++) {
686		if (j > 1) {
687			isosb = (struct iso_volume_descriptor *)
688				get_buffer(probe, j*bs*2048+32768,
689					   sizeof(isosb));
690			if (!isosb)
691				return 1;
692		}
693		/* If we find NSR0x then call it udf:
694		   NSR01 for UDF 1.00
695		   NSR02 for UDF 1.50
696		   NSR03 for UDF 2.00 */
697		if (!memcmp(isosb->vd_id, "NSR0", 4))
698			return 0;
699		for (m = udf_magic; *m; m++)
700			if (!memcmp(*m, isosb->vd_id, 5))
701				break;
702		if (*m == 0)
703			return 1;
704	}
705	return 1;
706}
707
708static int probe_ocfs(struct blkid_probe *probe,
709		      struct blkid_magic *id __BLKID_ATTR((unused)),
710		      unsigned char *buf)
711{
712	struct ocfs_volume_header ovh;
713	struct ocfs_volume_label ovl;
714	__u32 major;
715
716	memcpy(&ovh, buf, sizeof(ovh));
717	memcpy(&ovl, buf+512, sizeof(ovl));
718
719	major = ocfsmajor(ovh);
720	if (major == 1)
721		blkid_set_tag(probe->dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
722	else if (major >= 9)
723		blkid_set_tag(probe->dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
724
725	blkid_set_tag(probe->dev, "LABEL", ovl.label, ocfslabellen(ovl));
726	blkid_set_tag(probe->dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
727	set_uuid(probe->dev, ovl.vol_id, 0);
728	return 0;
729}
730
731static int probe_ocfs2(struct blkid_probe *probe,
732		       struct blkid_magic *id __BLKID_ATTR((unused)),
733		       unsigned char *buf)
734{
735	struct ocfs2_super_block *osb;
736
737	osb = (struct ocfs2_super_block *)buf;
738
739	blkid_set_tag(probe->dev, "LABEL", osb->s_label, sizeof(osb->s_label));
740	set_uuid(probe->dev, osb->s_uuid, 0);
741	return 0;
742}
743
744static int probe_oracleasm(struct blkid_probe *probe,
745			   struct blkid_magic *id __BLKID_ATTR((unused)),
746			   unsigned char *buf)
747{
748	struct oracle_asm_disk_label *dl;
749
750	dl = (struct oracle_asm_disk_label *)buf;
751
752	blkid_set_tag(probe->dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
753	return 0;
754}
755
756static int probe_gfs(struct blkid_probe *probe,
757		     struct blkid_magic *id __BLKID_ATTR((unused)),
758		     unsigned char *buf)
759{
760	struct gfs2_sb *sbd;
761	const char *label = 0;
762
763	sbd = (struct gfs2_sb *)buf;
764
765	if (blkid_be32(sbd->sb_fs_format) == GFS_FORMAT_FS &&
766	    blkid_be32(sbd->sb_multihost_format) == GFS_FORMAT_MULTI)
767	{
768		blkid_set_tag(probe->dev, "UUID", 0, 0);
769
770		if (strlen(sbd->sb_locktable))
771			label = sbd->sb_locktable;
772		blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
773		return 0;
774	}
775	return 1;
776}
777
778static int probe_gfs2(struct blkid_probe *probe,
779		     struct blkid_magic *id __BLKID_ATTR((unused)),
780		     unsigned char *buf)
781{
782	struct gfs2_sb *sbd;
783	const char *label = 0;
784
785	sbd = (struct gfs2_sb *)buf;
786
787	if (blkid_be32(sbd->sb_fs_format) == GFS2_FORMAT_FS &&
788	    blkid_be32(sbd->sb_multihost_format) == GFS2_FORMAT_MULTI)
789	{
790		blkid_set_tag(probe->dev, "UUID", 0, 0);
791
792		if (strlen(sbd->sb_locktable))
793			label = sbd->sb_locktable;
794		blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
795		return 0;
796	}
797	return 1;
798}
799
800/*
801 * BLKID_BLK_OFFS is at least as large as the highest bim_kboff defined
802 * in the type_array table below + bim_kbalign.
803 *
804 * When probing for a lot of magics, we handle everything in 1kB buffers so
805 * that we don't have to worry about reading each combination of block sizes.
806 */
807#define BLKID_BLK_OFFS	64	/* currently reiserfs */
808
809/*
810 * Various filesystem magics that we can check for.  Note that kboff and
811 * sboff are in kilobytes and bytes respectively.  All magics are in
812 * byte strings so we don't worry about endian issues.
813 */
814static struct blkid_magic type_array[] = {
815/*  type     kboff   sboff len  magic			probe */
816  { "oracleasm", 0,	32,  8, "ORCLDISK",		probe_oracleasm },
817  { "ntfs",	 0,	 3,  8, "NTFS    ",		probe_ntfs },
818  { "jbd",	 1,   0x38,  2, "\123\357",		probe_jbd },
819  { "ext3",	 1,   0x38,  2, "\123\357",		probe_ext3 },
820  { "ext2",	 1,   0x38,  2, "\123\357",		probe_ext2 },
821  { "reiserfs",	 8,   0x34,  8, "ReIsErFs",		probe_reiserfs },
822  { "reiserfs", 64,   0x34,  9, "ReIsEr2Fs",		probe_reiserfs },
823  { "reiserfs", 64,   0x34,  9, "ReIsEr3Fs",		probe_reiserfs },
824  { "reiserfs", 64,   0x34,  8, "ReIsErFs",		probe_reiserfs },
825  { "reiserfs",	 8,	20,  8, "ReIsErFs",		probe_reiserfs },
826  { "reiser4",  64,	 0,  7, "ReIsEr4",		probe_reiserfs4 },
827  { "gfs2",     64,      0,  4, "\x01\x16\x19\x70",     probe_gfs2 },
828  { "gfs",      64,      0,  4, "\x01\x16\x19\x70",     probe_gfs },
829  { "vfat",      0,   0x52,  5, "MSWIN",                probe_fat },
830  { "vfat",      0,   0x52,  8, "FAT32   ",             probe_fat },
831  { "vfat",      0,   0x36,  5, "MSDOS",                probe_fat },
832  { "vfat",      0,   0x36,  8, "FAT16   ",             probe_fat },
833  { "vfat",      0,   0x36,  8, "FAT12   ",             probe_fat },
834  { "vfat",      0,      0,  2, "\353\220",             probe_fat_nomagic },
835  { "vfat",      0,      0,  1, "\351",                 probe_fat_nomagic },
836  { "minix",     1,   0x10,  2, "\177\023",             0 },
837  { "minix",     1,   0x10,  2, "\217\023",             0 },
838  { "minix",	 1,   0x10,  2, "\150\044",		0 },
839  { "minix",	 1,   0x10,  2, "\170\044",		0 },
840  { "vxfs",	 1,	 0,  4, "\365\374\001\245",	0 },
841  { "xfs",	 0,	 0,  4, "XFSB",			probe_xfs },
842  { "romfs",	 0,	 0,  8, "-rom1fs-",		probe_romfs },
843  { "bfs",	 0,	 0,  4, "\316\372\173\033",	0 },
844  { "cramfs",	 0,	 0,  4, "E=\315\050",		probe_cramfs },
845  { "qnx4",	 0,	 4,  6, "QNX4FS",		0 },
846  { "udf",	32,	 1,  5, "BEA01",		probe_udf },
847  { "udf",	32,	 1,  5, "BOOT2",		probe_udf },
848  { "udf",	32,	 1,  5, "CD001",		probe_udf },
849  { "udf",	32,	 1,  5, "CDW02",		probe_udf },
850  { "udf",	32,	 1,  5, "NSR02",		probe_udf },
851  { "udf",	32,	 1,  5, "NSR03",		probe_udf },
852  { "udf",	32,	 1,  5, "TEA01",		probe_udf },
853  { "iso9660",	32,	 1,  5, "CD001",		probe_iso9660 },
854  { "iso9660",	32,	 9,  5, "CDROM",		probe_iso9660 },
855  { "jfs",	32,	 0,  4, "JFS1",			probe_jfs },
856  { "hfs",	 1,	 0,  2, "BD",			0 },
857  { "ufs",	 8,  0x55c,  4, "T\031\001\000",	0 },
858  { "hpfs",	 8,	 0,  4, "I\350\225\371",	0 },
859  { "sysv",	 0,  0x3f8,  4, "\020~\030\375",	0 },
860  { "swap",	 0,  0xff6, 10, "SWAP-SPACE",		probe_swap0 },
861  { "swap",	 0,  0xff6, 10, "SWAPSPACE2",		probe_swap1 },
862  { "swsuspend", 0,  0xff6,  9, "S1SUSPEND",		probe_swap1 },
863  { "swsuspend", 0,  0xff6,  9, "S2SUSPEND",		probe_swap1 },
864  { "swap",	 0, 0x1ff6, 10, "SWAP-SPACE",		probe_swap0 },
865  { "swap",	 0, 0x1ff6, 10, "SWAPSPACE2",		probe_swap1 },
866  { "swsuspend", 0, 0x1ff6,  9, "S1SUSPEND",		probe_swap1 },
867  { "swsuspend", 0, 0x1ff6,  9, "S2SUSPEND",		probe_swap1 },
868  { "swap",	 0, 0x3ff6, 10, "SWAP-SPACE",		probe_swap0 },
869  { "swap",	 0, 0x3ff6, 10, "SWAPSPACE2",		probe_swap1 },
870  { "swsuspend", 0, 0x3ff6,  9, "S1SUSPEND",		probe_swap1 },
871  { "swsuspend", 0, 0x3ff6,  9, "S2SUSPEND",		probe_swap1 },
872  { "swap",	 0, 0x7ff6, 10, "SWAP-SPACE",		probe_swap0 },
873  { "swap",	 0, 0x7ff6, 10, "SWAPSPACE2",		probe_swap1 },
874  { "swsuspend", 0, 0x7ff6,  9, "S1SUSPEND",		probe_swap1 },
875  { "swsuspend", 0, 0x7ff6,  9, "S2SUSPEND",		probe_swap1 },
876  { "swap",	 0, 0xfff6, 10, "SWAP-SPACE",		probe_swap0 },
877  { "swap",	 0, 0xfff6, 10, "SWAPSPACE2",		probe_swap1 },
878  { "swsuspend", 0, 0xfff6,  9, "S1SUSPEND",		probe_swap1 },
879  { "swsuspend", 0, 0xfff6,  9, "S2SUSPEND",		probe_swap1 },
880  { "ocfs",	 0,	 8,  9,	"OracleCFS",		probe_ocfs },
881  { "ocfs2",	 1,	 0,  6,	"OCFSV2",		probe_ocfs2 },
882  { "ocfs2",	 2,	 0,  6,	"OCFSV2",		probe_ocfs2 },
883  { "ocfs2",	 4,	 0,  6,	"OCFSV2",		probe_ocfs2 },
884  { "ocfs2",	 8,	 0,  6,	"OCFSV2",		probe_ocfs2 },
885  {   NULL,	 0,	 0,  0, NULL,			NULL }
886};
887
888/*
889 * Verify that the data in dev is consistent with what is on the actual
890 * block device (using the devname field only).  Normally this will be
891 * called when finding items in the cache, but for long running processes
892 * is also desirable to revalidate an item before use.
893 *
894 * If we are unable to revalidate the data, we return the old data and
895 * do not set the BLKID_BID_FL_VERIFIED flag on it.
896 */
897blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
898{
899	struct blkid_magic *id;
900	struct blkid_probe probe;
901	blkid_tag_iterate iter;
902	unsigned char *buf;
903	const char *type, *value;
904	struct stat st;
905	time_t diff, now;
906	int idx;
907
908	if (!dev)
909		return NULL;
910
911	now = time(0);
912	diff = now - dev->bid_time;
913
914	if ((now > dev->bid_time) && (diff > 0) &&
915	    ((diff < BLKID_PROBE_MIN) ||
916	     (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
917	      diff < BLKID_PROBE_INTERVAL)))
918		return dev;
919
920	DBG(DEBUG_PROBE,
921	    printf("need to revalidate %s (time since last check %llu)\n",
922		   dev->bid_name, (unsigned long long)diff));
923
924	if (((probe.fd = open(dev->bid_name, O_RDONLY)) < 0) ||
925	    (fstat(probe.fd, &st) < 0)) {
926		if (probe.fd >= 0) close(probe.fd);
927		if (errno == ENXIO || errno == ENODEV || errno == ENOENT) {
928			blkid_free_dev(dev);
929			return NULL;
930		}
931		/* We don't have read permission, just return cache data. */
932		DBG(DEBUG_PROBE,
933		    printf("returning unverified data for %s\n",
934			   dev->bid_name));
935		return dev;
936	}
937
938	probe.cache = cache;
939	probe.dev = dev;
940	probe.sbbuf = 0;
941	probe.buf = 0;
942	probe.buf_max = 0;
943
944	/*
945	 * Iterate over the type array.  If we already know the type,
946	 * then try that first.  If it doesn't work, then blow away
947	 * the type information, and try again.
948	 *
949	 */
950try_again:
951	type = 0;
952	if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
953		uuid_t	uuid;
954
955		if (check_mdraid(probe.fd, uuid) == 0) {
956			set_uuid(dev, uuid, 0);
957			type = "mdraid";
958			goto found_type;
959		}
960	}
961	for (id = type_array; id->bim_type; id++) {
962		if (dev->bid_type &&
963		    strcmp(id->bim_type, dev->bid_type))
964			continue;
965
966		idx = id->bim_kboff + (id->bim_sboff >> 10);
967		buf = get_buffer(&probe, idx << 10, 1024);
968		if (!buf)
969			continue;
970
971		if (memcmp(id->bim_magic, buf + (id->bim_sboff&0x3ff),
972			   id->bim_len))
973			continue;
974
975		if ((id->bim_probe == NULL) ||
976		    (id->bim_probe(&probe, id, buf) == 0)) {
977			type = id->bim_type;
978			goto found_type;
979		}
980	}
981
982	if (!id->bim_type && dev->bid_type) {
983		/*
984		 * Zap the device filesystem information and try again
985		 */
986		iter = blkid_tag_iterate_begin(dev);
987		while (blkid_tag_next(iter, &type, &value) == 0)
988			blkid_set_tag(dev, type, 0, 0);
989		blkid_tag_iterate_end(iter);
990		goto try_again;
991	}
992
993	if (!dev->bid_type) {
994		blkid_free_dev(dev);
995		dev = 0;
996		goto found_type;
997	}
998
999found_type:
1000	if (dev && type) {
1001		dev->bid_devno = st.st_rdev;
1002		dev->bid_time = time(0);
1003		dev->bid_flags |= BLKID_BID_FL_VERIFIED;
1004		cache->bic_flags |= BLKID_BIC_FL_CHANGED;
1005
1006		blkid_set_tag(dev, "TYPE", type, 0);
1007
1008		DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
1009			   dev->bid_name, (long long)st.st_rdev, type));
1010	}
1011
1012	if (probe.sbbuf)
1013		free(probe.sbbuf);
1014	if (probe.buf)
1015		free(probe.buf);
1016	if (probe.fd >= 0)
1017		close(probe.fd);
1018
1019	return dev;
1020}
1021
1022int blkid_known_fstype(const char *fstype)
1023{
1024	struct blkid_magic *id;
1025
1026	for (id = type_array; id->bim_type; id++) {
1027		if (strcmp(fstype, id->bim_type) == 0)
1028			return 1;
1029	}
1030	return 0;
1031}
1032
1033#ifdef TEST_PROGRAM
1034int main(int argc, char **argv)
1035{
1036	blkid_dev dev;
1037	blkid_cache cache;
1038	int ret;
1039
1040	if (argc != 2) {
1041		fprintf(stderr, "Usage: %s device\n"
1042			"Probe a single device to determine type\n", argv[0]);
1043		exit(1);
1044	}
1045	if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
1046		fprintf(stderr, "%s: error creating cache (%d)\n",
1047			argv[0], ret);
1048		exit(1);
1049	}
1050	dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
1051	if (!dev) {
1052		printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
1053		return (1);
1054	}
1055	printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");
1056	if (dev->bid_label)
1057		printf("LABEL='%s'\n", dev->bid_label);
1058	if (dev->bid_uuid)
1059		printf("UUID='%s'\n", dev->bid_uuid);
1060
1061	blkid_free_dev(dev);
1062	return (0);
1063}
1064#endif
1065