lib/blkid/probe.c

   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
  37 static 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
  50 static 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  */
  94 static 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
 126 static 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
 136 static 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  */
 167 static 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  */
 204 static 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
 240 static 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
 253 static 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
 266 static 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
 303 static 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
 344 static 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
 370 static 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
 393 static 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
 413 static const char *no_name = "NO NAME    ";
 414
 415 static 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 */
 438 static 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  */
 565 static 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
 593 static 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
 701 static 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
 717 static 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
 745 static 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
 761 static 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
 777 static 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
 783         /* 168 is the offset to the 40 character uuid:
 784          * http://luks.endorphin.org/LUKS-on-disk-format.pdf */
 785         strncpy(uuid, (char *) buf+168, 40);
 786         blkid_set_tag(probe->dev, "UUID", uuid, sizeof(uuid));
 787         return 0;
 788 }
 789
 790 static int probe_romfs(struct blkid_probe *probe,
 791                        struct blkid_magic *id __BLKID_ATTR((unused)),
 792                        unsigned char *buf)
 793 {
 794         struct romfs_super_block *ros;
 795         const char *label = 0;
 796
 797         ros = (struct romfs_super_block *)buf;
 798
 799         if (strlen((char *) ros->ros_volume))
 800                 label = (char *) ros->ros_volume;
 801         blkid_set_tag(probe->dev, "LABEL", label, 0);
 802         return 0;
 803 }
 804
 805 static int probe_cramfs(struct blkid_probe *probe,
 806                         struct blkid_magic *id __BLKID_ATTR((unused)),
 807                         unsigned char *buf)
 808 {
 809         struct cramfs_super_block *csb;
 810         const char *label = 0;
 811
 812         csb = (struct cramfs_super_block *)buf;
 813
 814         if (strlen((char *) csb->name))
 815                 label = (char *) csb->name;
 816         blkid_set_tag(probe->dev, "LABEL", label, 0);
 817         return 0;
 818 }
 819
 820 static int probe_swap0(struct blkid_probe *probe,
 821                        struct blkid_magic *id __BLKID_ATTR((unused)),
 822                        unsigned char *buf __BLKID_ATTR((unused)))
 823 {
 824         blkid_set_tag(probe->dev, "UUID", 0, 0);
 825         blkid_set_tag(probe->dev, "LABEL", 0, 0);
 826         return 0;
 827 }
 828
 829 static int probe_swap1(struct blkid_probe *probe,
 830                        struct blkid_magic *id,
 831                        unsigned char *buf __BLKID_ATTR((unused)))
 832 {
 833         struct swap_id_block *sws;
 834
 835         probe_swap0(probe, id, buf);
 836         /*
 837          * Version 1 swap headers are always located at offset of 1024
 838          * bytes, although the swap signature itself is located at the
 839          * end of the page (which may vary depending on hardware
 840          * pagesize).
 841          */
 842         sws = (struct swap_id_block *) get_buffer(probe, 1024, 1024);
 843         if (!sws)
 844                 return 1;
 845
 846         /* check for wrong version or zeroed pagecount, for sanity */
 847         if (!memcmp(id->bim_magic, "SWAPSPACE2", id->bim_len) &&
 848                         (sws->sws_version != 1 || sws->sws_lastpage == 0))
 849                 return 1;
 850
 851         /* arbitrary sanity check.. is there any garbage down there? */
 852         if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0)  {
 853                 if (sws->sws_volume[0])
 854                         blkid_set_tag(probe->dev, "LABEL", sws->sws_volume,
 855                                       sizeof(sws->sws_volume));
 856                 if (sws->sws_uuid[0])
 857                         set_uuid(probe->dev, sws->sws_uuid, 0);
 858         }
 859         return 0;
 860 }
 861
 862 static int probe_iso9660(struct blkid_probe *probe,
 863                          struct blkid_magic *id __BLKID_ATTR((unused)),
 864                          unsigned char *buf)
 865 {
 866         struct iso_volume_descriptor *iso;
 867         const unsigned char *label;
 868
 869         iso = (struct iso_volume_descriptor *) buf;
 870         label = iso->volume_id;
 871
 872         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 873                       figure_label_len(label, 32));
 874         return 0;
 875 }
 876
 877
 878 static const char
 879 *udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
 880                  "NSR03", "TEA01", 0 };
 881
 882 static int probe_udf(struct blkid_probe *probe,
 883                      struct blkid_magic *id __BLKID_ATTR((unused)),
 884                      unsigned char *buf __BLKID_ATTR((unused)))
 885 {
 886         int j, bs;
 887         struct iso_volume_descriptor *isosb;
 888         const char ** m;
 889
 890         /* determine the block size by scanning in 2K increments
 891            (block sizes larger than 2K will be null padded) */
 892         for (bs = 1; bs < 16; bs++) {
 893                 isosb = (struct iso_volume_descriptor *)
 894                         get_buffer(probe, bs*2048+32768, sizeof(isosb));
 895                 if (!isosb)
 896                         return 1;
 897                 if (isosb->vd_id[0])
 898                         break;
 899         }
 900
 901         /* Scan up to another 64 blocks looking for additional VSD's */
 902         for (j = 1; j < 64; j++) {
 903                 if (j > 1) {
 904                         isosb = (struct iso_volume_descriptor *)
 905                                 get_buffer(probe, j*bs*2048+32768,
 906                                            sizeof(isosb));
 907                         if (!isosb)
 908                                 return 1;
 909                 }
 910                 /* If we find NSR0x then call it udf:
 911                    NSR01 for UDF 1.00
 912                    NSR02 for UDF 1.50
 913                    NSR03 for UDF 2.00 */
 914                 if (!memcmp(isosb->vd_id, "NSR0", 4))
 915                         return probe_iso9660(probe, id, buf);
 916                 for (m = udf_magic; *m; m++)
 917                         if (!memcmp(*m, isosb->vd_id, 5))
 918                                 break;
 919                 if (*m == 0)
 920                         return 1;
 921         }
 922         return 1;
 923 }
 924
 925 static int probe_ocfs(struct blkid_probe *probe,
 926                       struct blkid_magic *id __BLKID_ATTR((unused)),
 927                       unsigned char *buf)
 928 {
 929         struct ocfs_volume_header ovh;
 930         struct ocfs_volume_label ovl;
 931         __u32 major;
 932
 933         memcpy(&ovh, buf, sizeof(ovh));
 934         memcpy(&ovl, buf+512, sizeof(ovl));
 935
 936         major = ocfsmajor(ovh);
 937         if (major == 1)
 938                 blkid_set_tag(probe->dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
 939         else if (major >= 9)
 940                 blkid_set_tag(probe->dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
 941
 942         blkid_set_tag(probe->dev, "LABEL", ovl.label, ocfslabellen(ovl));
 943         blkid_set_tag(probe->dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
 944         set_uuid(probe->dev, ovl.vol_id, 0);
 945         return 0;
 946 }
 947
 948 static int probe_ocfs2(struct blkid_probe *probe,
 949                        struct blkid_magic *id __BLKID_ATTR((unused)),
 950                        unsigned char *buf)
 951 {
 952         struct ocfs2_super_block *osb;
 953
 954         osb = (struct ocfs2_super_block *)buf;
 955
 956         blkid_set_tag(probe->dev, "LABEL", osb->s_label, sizeof(osb->s_label));
 957         set_uuid(probe->dev, osb->s_uuid, 0);
 958         return 0;
 959 }
 960
 961 static int probe_oracleasm(struct blkid_probe *probe,
 962                            struct blkid_magic *id __BLKID_ATTR((unused)),
 963                            unsigned char *buf)
 964 {
 965         struct oracle_asm_disk_label *dl;
 966
 967         dl = (struct oracle_asm_disk_label *)buf;
 968
 969         blkid_set_tag(probe->dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
 970         return 0;
 971 }
 972
 973 static int probe_gfs(struct blkid_probe *probe,
 974                      struct blkid_magic *id __BLKID_ATTR((unused)),
 975                      unsigned char *buf)
 976 {
 977         struct gfs2_sb *sbd;
 978         const char *label = 0;
 979
 980         sbd = (struct gfs2_sb *)buf;
 981
 982         if (blkid_be32(sbd->sb_fs_format) == GFS_FORMAT_FS &&
 983             blkid_be32(sbd->sb_multihost_format) == GFS_FORMAT_MULTI)
 984         {
 985                 blkid_set_tag(probe->dev, "UUID", 0, 0);
 986
 987                 if (strlen(sbd->sb_locktable))
 988                         label = sbd->sb_locktable;
 989                 blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
 990                 return 0;
 991         }
 992         return 1;
 993 }
 994
 995 static int probe_gfs2(struct blkid_probe *probe,
 996                      struct blkid_magic *id __BLKID_ATTR((unused)),
 997                      unsigned char *buf)
 998 {
 999         struct gfs2_sb *sbd;
1000         const char *label = 0;
1001
1002         sbd = (struct gfs2_sb *)buf;
1003
1004         if (blkid_be32(sbd->sb_fs_format) == GFS2_FORMAT_FS &&
1005             blkid_be32(sbd->sb_multihost_format) == GFS2_FORMAT_MULTI)
1006         {
1007                 blkid_set_tag(probe->dev, "UUID", 0, 0);
1008
1009                 if (strlen(sbd->sb_locktable))
1010                         label = sbd->sb_locktable;
1011                 blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
1012                 return 0;
1013         }
1014         return 1;
1015 }
1016
1017 static int probe_hfsplus(struct blkid_probe *probe __BLKID_ATTR((unused)),
1018                          struct blkid_magic *id __BLKID_ATTR((unused)),
1019                          unsigned char *buf)
1020 {
1021         struct hfs_mdb *sbd = (struct hfs_mdb *)buf;
1022
1023         /* Check for a HFS+ volume embedded in a HFS volume */
1024         if (memcmp(sbd->embed_sig, "H+", 2) == 0)
1025                 return 0;
1026
1027         return 1;
1028 }
1029
1030 #define LVM2_LABEL_SIZE 512
1031 static unsigned int lvm2_calc_crc(const void *buf, unsigned int size)
1032 {
1033         static const unsigned int crctab[] = {
1034                 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
1035                 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
1036                 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
1037                 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
1038         };
1039         unsigned int i, crc = 0xf597a6cf;
1040         const __u8 *data = (const __u8 *) buf;
1041
1042         for (i = 0; i < size; i++) {
1043                 crc ^= *data++;
1044                 crc = (crc >> 4) ^ crctab[crc & 0xf];
1045                 crc = (crc >> 4) ^ crctab[crc & 0xf];
1046         }
1047         return crc;
1048 }
1049
1050 static int probe_lvm2(struct blkid_probe *probe,
1051                         struct blkid_magic *id __BLKID_ATTR((unused)),
1052                         unsigned char *buf)
1053 {
1054         int sector = (id->bim_kboff) << 1;;
1055         struct lvm2_pv_label_header *label;
1056         label = (struct lvm2_pv_label_header *)buf;
1057         char *p, *q, uuid[40];
1058         unsigned int i, b;
1059
1060         /* buf is at 0k or 1k offset; find label inside */
1061         if (memcmp(buf, "LABELONE", 8) == 0) {
1062                 label = (struct lvm2_pv_label_header *)buf;
1063         } else if (memcmp(buf + 512, "LABELONE", 8) == 0) {
1064                 label = (struct lvm2_pv_label_header *)(buf + 512);
1065                 sector++;
1066         } else {
1067                 return 1;
1068         }
1069
1070         if (blkid_le64(label->sector_xl) != (unsigned) sector) {
1071                 DBG(DEBUG_PROBE,
1072                     printf("LVM2: label for sector %llu found at sector %d\n",
1073                            blkid_le64(label->sector_xl), sector));
1074                 return 1;
1075         }
1076
1077         if (lvm2_calc_crc(&label->offset_xl, LVM2_LABEL_SIZE -
1078                           ((char *)&label->offset_xl - (char *)label)) !=
1079                         blkid_le32(label->crc_xl)) {
1080                 DBG(DEBUG_PROBE,
1081                     printf("LVM2: label checksum incorrect at sector %d\n",
1082                            sector));
1083                 return 1;
1084         }
1085
1086         for (i=0, b=1, p=uuid, q= (char *) label->pv_uuid; i <= 32;
1087              i++, b <<= 1) {
1088                 if (b & 0x4444440)
1089                         *p++ = '-';
1090                 *p++ = *q++;
1091         }
1092
1093         blkid_set_tag(probe->dev, "UUID", uuid, LVM2_ID_LEN+6);
1094
1095         return 0;
1096 }
1097 /*
1098  * BLKID_BLK_OFFS is at least as large as the highest bim_kboff defined
1099  * in the type_array table below + bim_kbalign.
1100  *
1101  * When probing for a lot of magics, we handle everything in 1kB buffers so
1102  * that we don't have to worry about reading each combination of block sizes.
1103  */
1104 #define BLKID_BLK_OFFS  64      /* currently reiserfs */
1105
1106 /*
1107  * Various filesystem magics that we can check for.  Note that kboff and
1108  * sboff are in kilobytes and bytes respectively.  All magics are in
1109  * byte strings so we don't worry about endian issues.
1110  */
1111 static struct blkid_magic type_array[] = {
1112 /*  type     kboff   sboff len  magic                   probe */
1113   { "oracleasm", 0,     32,  8, "ORCLDISK",             probe_oracleasm },
1114   { "ntfs",      0,      3,  8, "NTFS    ",             probe_ntfs },
1115   { "jbd",       1,   0x38,  2, "\123\357",             probe_jbd },
1116   { "ext4dev",   1,   0x38,  2, "\123\357",             probe_ext4dev },
1117   { "ext4",      1,   0x38,  2, "\123\357",             probe_ext4 },
1118   { "ext3",      1,   0x38,  2, "\123\357",             probe_ext3 },
1119   { "ext2",      1,   0x38,  2, "\123\357",             probe_ext2 },
1120   { "reiserfs",  8,   0x34,  8, "ReIsErFs",             probe_reiserfs },
1121   { "reiserfs", 64,   0x34,  9, "ReIsEr2Fs",            probe_reiserfs },
1122   { "reiserfs", 64,   0x34,  9, "ReIsEr3Fs",            probe_reiserfs },
1123   { "reiserfs", 64,   0x34,  8, "ReIsErFs",             probe_reiserfs },
1124   { "reiserfs",  8,     20,  8, "ReIsErFs",             probe_reiserfs },
1125   { "reiser4",  64,      0,  7, "ReIsEr4",              probe_reiserfs4 },
1126   { "gfs2",     64,      0,  4, "\x01\x16\x19\x70",     probe_gfs2 },
1127   { "gfs",      64,      0,  4, "\x01\x16\x19\x70",     probe_gfs },
1128   { "vfat",      0,   0x52,  5, "MSWIN",                probe_fat },
1129   { "vfat",      0,   0x52,  8, "FAT32   ",             probe_fat },
1130   { "vfat",      0,   0x36,  5, "MSDOS",                probe_fat },
1131   { "vfat",      0,   0x36,  8, "FAT16   ",             probe_fat },
1132   { "vfat",      0,   0x36,  8, "FAT12   ",             probe_fat },
1133   { "vfat",      0,      0,  1, "\353",                 probe_fat_nomagic },
1134   { "vfat",      0,      0,  1, "\351",                 probe_fat_nomagic },
1135   { "vfat",      0,  0x1fe,  2, "\125\252",             probe_fat_nomagic },
1136   { "minix",     1,   0x10,  2, "\177\023",             0 },
1137   { "minix",     1,   0x10,  2, "\217\023",             0 },
1138   { "minix",     1,   0x10,  2, "\150\044",             0 },
1139   { "minix",     1,   0x10,  2, "\170\044",             0 },
1140   { "vxfs",      1,      0,  4, "\365\374\001\245",     0 },
1141   { "xfs",       0,      0,  4, "XFSB",                 probe_xfs },
1142   { "romfs",     0,      0,  8, "-rom1fs-",             probe_romfs },
1143   { "bfs",       0,      0,  4, "\316\372\173\033",     0 },
1144   { "cramfs",    0,      0,  4, "E=\315\050",           probe_cramfs },
1145   { "qnx4",      0,      4,  6, "QNX4FS",               0 },
1146   { "udf",      32,      1,  5, "BEA01",                probe_udf },
1147   { "udf",      32,      1,  5, "BOOT2",                probe_udf },
1148   { "udf",      32,      1,  5, "CD001",                probe_udf },
1149   { "udf",      32,      1,  5, "CDW02",                probe_udf },
1150   { "udf",      32,      1,  5, "NSR02",                probe_udf },
1151   { "udf",      32,      1,  5, "NSR03",                probe_udf },
1152   { "udf",      32,      1,  5, "TEA01",                probe_udf },
1153   { "iso9660",  32,      1,  5, "CD001",                probe_iso9660 },
1154   { "iso9660",  32,      9,  5, "CDROM",                probe_iso9660 },
1155   { "jfs",      32,      0,  4, "JFS1",                 probe_jfs },
1156   { "hfsplus",   1,      0,  2, "BD",                   probe_hfsplus },
1157   { "hfsplus",   1,      0,  2, "H+",                   0 },
1158   { "hfs",       1,      0,  2, "BD",                   0 },
1159   { "ufs",       8,  0x55c,  4, "T\031\001\000",        0 },
1160   { "hpfs",      8,      0,  4, "I\350\225\371",        0 },
1161   { "sysv",      0,  0x3f8,  4, "\020~\030\375",        0 },
1162   { "swap",      0,  0xff6, 10, "SWAP-SPACE",           probe_swap0 },
1163   { "swap",      0,  0xff6, 10, "SWAPSPACE2",           probe_swap1 },
1164   { "swsuspend", 0,  0xff6,  9, "S1SUSPEND",            probe_swap1 },
1165   { "swsuspend", 0,  0xff6,  9, "S2SUSPEND",            probe_swap1 },
1166   { "swap",      0, 0x1ff6, 10, "SWAP-SPACE",           probe_swap0 },
1167   { "swap",      0, 0x1ff6, 10, "SWAPSPACE2",           probe_swap1 },
1168   { "swsuspend", 0, 0x1ff6,  9, "S1SUSPEND",            probe_swap1 },
1169   { "swsuspend", 0, 0x1ff6,  9, "S2SUSPEND",            probe_swap1 },
1170   { "swap",      0, 0x3ff6, 10, "SWAP-SPACE",           probe_swap0 },
1171   { "swap",      0, 0x3ff6, 10, "SWAPSPACE2",           probe_swap1 },
1172   { "swsuspend", 0, 0x3ff6,  9, "S1SUSPEND",            probe_swap1 },
1173   { "swsuspend", 0, 0x3ff6,  9, "S2SUSPEND",            probe_swap1 },
1174   { "swap",      0, 0x7ff6, 10, "SWAP-SPACE",           probe_swap0 },
1175   { "swap",      0, 0x7ff6, 10, "SWAPSPACE2",           probe_swap1 },
1176   { "swsuspend", 0, 0x7ff6,  9, "S1SUSPEND",            probe_swap1 },
1177   { "swsuspend", 0, 0x7ff6,  9, "S2SUSPEND",            probe_swap1 },
1178   { "swap",      0, 0xfff6, 10, "SWAP-SPACE",           probe_swap0 },
1179   { "swap",      0, 0xfff6, 10, "SWAPSPACE2",           probe_swap1 },
1180   { "swsuspend", 0, 0xfff6,  9, "S1SUSPEND",            probe_swap1 },
1181   { "swsuspend", 0, 0xfff6,  9, "S2SUSPEND",            probe_swap1 },
1182   { "ocfs",      0,      8,  9, "OracleCFS",            probe_ocfs },
1183   { "ocfs2",     1,      0,  6, "OCFSV2",               probe_ocfs2 },
1184   { "ocfs2",     2,      0,  6, "OCFSV2",               probe_ocfs2 },
1185   { "ocfs2",     4,      0,  6, "OCFSV2",               probe_ocfs2 },
1186   { "ocfs2",     8,      0,  6, "OCFSV2",               probe_ocfs2 },
1187   { "crypt_LUKS", 0,     0,  6, "LUKS\xba\xbe",         probe_luks },
1188   { "squashfs",  0,      0,  4, "sqsh",                 0 },
1189   { "squashfs",  0,      0,  4, "hsqs",                 0 },
1190   { "lvm2pv",    0,  0x218,  8, "LVM2 001",             probe_lvm2 },
1191   { "lvm2pv",    0,  0x018,  8, "LVM2 001",             probe_lvm2 },
1192   { "lvm2pv",    1,  0x018,  8, "LVM2 001",             probe_lvm2 },
1193   { "lvm2pv",    1,  0x218,  8, "LVM2 001",             probe_lvm2 },
1194   {   NULL,      0,      0,  0, NULL,                   NULL }
1195 };
1196
1197 /*
1198  * Verify that the data in dev is consistent with what is on the actual
1199  * block device (using the devname field only).  Normally this will be
1200  * called when finding items in the cache, but for long running processes
1201  * is also desirable to revalidate an item before use.
1202  *
1203  * If we are unable to revalidate the data, we return the old data and
1204  * do not set the BLKID_BID_FL_VERIFIED flag on it.
1205  */
1206 blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
1207 {
1208         struct blkid_magic *id;
1209         struct blkid_probe probe;
1210         blkid_tag_iterate iter;
1211         unsigned char *buf;
1212         const char *type, *value;
1213         struct stat st;
1214         time_t diff, now;
1215         int idx;
1216
1217         if (!dev)
1218                 return NULL;
1219
1220         now = time(0);
1221         diff = now - dev->bid_time;
1222
1223         if (stat(dev->bid_name, &st) < 0) {
1224                 DBG(DEBUG_PROBE,
1225                     printf("blkid_verify: error %s (%d) while "
1226                            "trying to stat %s\n", strerror(errno), errno,
1227                            dev->bid_name));
1228         open_err:
1229                 if ((errno == EPERM) || (errno == EACCES) || (errno == ENOENT)) {
1230                         /* We don't have read permission, just return cache data. */
1231                         DBG(DEBUG_PROBE, printf("returning unverified data for %s\n",
1232                                                 dev->bid_name));
1233                         return dev;
1234                 }
1235                 blkid_free_dev(dev);
1236                 return NULL;
1237         }
1238
1239         if ((now >= dev->bid_time) &&
1240             (st.st_mtime <= dev->bid_time) &&
1241             ((diff < BLKID_PROBE_MIN) ||
1242              (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
1243               diff < BLKID_PROBE_INTERVAL)))
1244                 return dev;
1245
1246         DBG(DEBUG_PROBE,
1247             printf("need to revalidate %s (cache time %d, stat time %d,\n\t"
1248                    "time since last check %lu)\n",
1249                    dev->bid_name, dev->bid_time, st.st_mtime, (unsigned long)diff));
1250
1251         if ((probe.fd = open(dev->bid_name, O_RDONLY)) < 0) {
1252                 DBG(DEBUG_PROBE, printf("blkid_verify: error %s (%d) while "
1253                                         "opening %s\n", strerror(errno), errno,
1254                                         dev->bid_name));
1255                 goto open_err;
1256         }
1257
1258         probe.cache = cache;
1259         probe.dev = dev;
1260         probe.sbbuf = 0;
1261         probe.buf = 0;
1262         probe.buf_max = 0;
1263
1264         /*
1265          * Iterate over the type array.  If we already know the type,
1266          * then try that first.  If it doesn't work, then blow away
1267          * the type information, and try again.
1268          *
1269          */
1270 try_again:
1271         type = 0;
1272         if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
1273                 uuid_t  uuid;
1274
1275                 if (check_mdraid(probe.fd, uuid) == 0) {
1276                         set_uuid(dev, uuid, 0);
1277                         type = "mdraid";
1278                         goto found_type;
1279                 }
1280         }
1281         for (id = type_array; id->bim_type; id++) {
1282                 if (dev->bid_type &&
1283                     strcmp(id->bim_type, dev->bid_type))
1284                         continue;
1285
1286                 idx = id->bim_kboff + (id->bim_sboff >> 10);
1287                 buf = get_buffer(&probe, idx << 10, 1024);
1288                 if (!buf)
1289                         continue;
1290
1291                 if (memcmp(id->bim_magic, buf + (id->bim_sboff&0x3ff),
1292                            id->bim_len))
1293                         continue;
1294
1295                 if ((id->bim_probe == NULL) ||
1296                     (id->bim_probe(&probe, id, buf) == 0)) {
1297                         type = id->bim_type;
1298                         goto found_type;
1299                 }
1300         }
1301
1302         if (!id->bim_type && dev->bid_type) {
1303                 /*
1304                  * Zap the device filesystem information and try again
1305                  */
1306                 DBG(DEBUG_PROBE,
1307                     printf("previous fs type %s not valid, "
1308                            "trying full probe\n", dev->bid_type));
1309                 iter = blkid_tag_iterate_begin(dev);
1310                 while (blkid_tag_next(iter, &type, &value) == 0)
1311                         blkid_set_tag(dev, type, 0, 0);
1312                 blkid_tag_iterate_end(iter);
1313                 goto try_again;
1314         }
1315
1316         if (!dev->bid_type) {
1317                 blkid_free_dev(dev);
1318                 dev = 0;
1319                 goto found_type;
1320         }
1321
1322 found_type:
1323         if (dev && type) {
1324                 dev->bid_devno = st.st_rdev;
1325                 dev->bid_time = time(0);
1326                 dev->bid_flags |= BLKID_BID_FL_VERIFIED;
1327                 cache->bic_flags |= BLKID_BIC_FL_CHANGED;
1328
1329                 blkid_set_tag(dev, "TYPE", type, 0);
1330
1331                 DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
1332                            dev->bid_name, (long long)st.st_rdev, type));
1333         }
1334
1335         if (probe.sbbuf)
1336                 free(probe.sbbuf);
1337         if (probe.buf)
1338                 free(probe.buf);
1339         if (probe.fd >= 0)
1340                 close(probe.fd);
1341
1342         return dev;
1343 }
1344
1345 int blkid_known_fstype(const char *fstype)
1346 {
1347         struct blkid_magic *id;
1348
1349         for (id = type_array; id->bim_type; id++) {
1350                 if (strcmp(fstype, id->bim_type) == 0)
1351                         return 1;
1352         }
1353         return 0;
1354 }
1355
1356 #ifdef TEST_PROGRAM
1357 int main(int argc, char **argv)
1358 {
1359         blkid_dev dev;
1360         blkid_cache cache;
1361         int ret;
1362
1363         if (argc != 2) {
1364                 fprintf(stderr, "Usage: %s device\n"
1365                         "Probe a single device to determine type\n", argv[0]);
1366                 exit(1);
1367         }
1368         if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
1369                 fprintf(stderr, "%s: error creating cache (%d)\n",
1370                         argv[0], ret);
1371                 exit(1);
1372         }
1373         dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
1374         if (!dev) {
1375                 printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
1376                 return (1);
1377         }
1378         printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");
1379         if (dev->bid_label)
1380                 printf("LABEL='%s'\n", dev->bid_label);
1381         if (dev->bid_uuid)
1382                 printf("UUID='%s'\n", dev->bid_uuid);
1383
1384         blkid_free_dev(dev);
1385         return (0);
1386 }
1387 #endif