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 "config.h"
  17 #include <stdio.h>
  18 #include <string.h>
  19 #include <stdlib.h>
  20 #include <time.h>
  21 #include <unistd.h>
  22 #include <fcntl.h>
  23 #include <ctype.h>
  24 #include <sys/types.h>
  25 #ifdef HAVE_SYS_STAT_H
  26 #include <sys/stat.h>
  27 #endif
  28 #ifdef HAVE_SYS_MKDEV_H
  29 #include <sys/mkdev.h>
  30 #endif
  31 #ifdef __linux__
  32 #include <sys/utsname.h>
  33 #endif
  34 #ifdef HAVE_ERRNO_H
  35 #include <errno.h>
  36 #endif
  37 #include "blkidP.h"
  38 #include "uuid/uuid.h"
  39 #include "probe.h"
  40
  41 static int figure_label_len(const unsigned char *label, int len)
  42 {
  43         const unsigned char *end = label + len - 1;
  44
  45         while (end >= label && (*end == ' ' || *end == 0))
  46                 --end;
  47         if (end >= label)
  48                 return end - label + 1;
  49         return 0;
  50 }
  51
  52 static unsigned char *get_buffer(struct blkid_probe *pr,
  53                           blkid_loff_t off, size_t len)
  54 {
  55         ssize_t         ret_read;
  56         unsigned char   *newbuf;
  57
  58         if (off + len <= SB_BUFFER_SIZE) {
  59                 if (!pr->sbbuf) {
  60                         pr->sbbuf = malloc(SB_BUFFER_SIZE);
  61                         if (!pr->sbbuf)
  62                                 return NULL;
  63                         if (lseek(pr->fd, 0, SEEK_SET) < 0)
  64                                 return NULL;
  65                         ret_read = read(pr->fd, pr->sbbuf, SB_BUFFER_SIZE);
  66                         if (ret_read < 0)
  67                                 ret_read = 0;
  68                         pr->sb_valid = ret_read;
  69                 }
  70                 if (off+len > pr->sb_valid)
  71                         return NULL;
  72                 return pr->sbbuf + off;
  73         } else {
  74                 if (len > pr->buf_max) {
  75                         newbuf = realloc(pr->buf, len);
  76                         if (newbuf == NULL)
  77                                 return NULL;
  78                         pr->buf = newbuf;
  79                         pr->buf_max = len;
  80                 }
  81                 if (blkid_llseek(pr->fd, off, SEEK_SET) < 0)
  82                         return NULL;
  83                 ret_read = read(pr->fd, pr->buf, len);
  84                 if (ret_read != (ssize_t) len)
  85                         return NULL;
  86                 return pr->buf;
  87         }
  88 }
  89
  90
  91 /*
  92  * This is a special case code to check for an MDRAID device.  We do
  93  * this special since it requires checking for a superblock at the end
  94  * of the device.
  95  */
  96 static int check_mdraid(int fd, unsigned char *ret_uuid)
  97 {
  98         struct mdp_superblock_s *md;
  99         blkid_loff_t            offset;
 100         char                    buf[4096];
 101
 102         if (fd < 0)
 103                 return -BLKID_ERR_PARAM;
 104
 105         offset = (blkid_get_dev_size(fd) & ~((blkid_loff_t)65535)) - 65536;
 106
 107         if (blkid_llseek(fd, offset, 0) < 0 ||
 108             read(fd, buf, 4096) != 4096)
 109                 return -BLKID_ERR_IO;
 110         /* Check for magic number */
 111         if (memcmp("\251+N\374", buf, 4) && memcmp("\374N+\251", buf, 4))
 112                 return -BLKID_ERR_PARAM;
 113
 114         if (!ret_uuid)
 115                 return 0;
 116         *ret_uuid = 0;
 117
 118         /* The MD UUID is not contiguous in the superblock, make it so */
 119         md = (struct mdp_superblock_s *)buf;
 120         if (md->set_uuid0 || md->set_uuid1 || md->set_uuid2 || md->set_uuid3) {
 121                 memcpy(ret_uuid, &md->set_uuid0, 4);
 122                 memcpy(ret_uuid + 4, &md->set_uuid1, 12);
 123         }
 124         return 0;
 125 }
 126
 127 static void set_uuid(blkid_dev dev, uuid_t uuid, const char *tag)
 128 {
 129         char    str[37];
 130
 131         if (!uuid_is_null(uuid)) {
 132                 uuid_unparse(uuid, str);
 133                 blkid_set_tag(dev, tag ? tag : "UUID", str, sizeof(str));
 134         }
 135 }
 136
 137 static void get_ext2_info(blkid_dev dev, struct blkid_magic *id,
 138                           unsigned char *buf)
 139 {
 140         struct ext2_super_block *es = (struct ext2_super_block *) buf;
 141         const char *label = 0;
 142
 143         DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",
 144                    blkid_le32(es->s_feature_compat),
 145                    blkid_le32(es->s_feature_incompat),
 146                    blkid_le32(es->s_feature_ro_compat)));
 147
 148         if (es->s_volume_name[0])
 149                 label = es->s_volume_name;
 150         blkid_set_tag(dev, "LABEL", label, sizeof(es->s_volume_name));
 151
 152         set_uuid(dev, es->s_uuid, 0);
 153
 154         if ((es->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
 155             !uuid_is_null(es->s_journal_uuid))
 156                 set_uuid(dev, es->s_journal_uuid, "EXT_JOURNAL");
 157
 158         if (strcmp(id->bim_type, "ext2") &&
 159             ((blkid_le32(es->s_feature_incompat) &
 160               EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0))
 161                 blkid_set_tag(dev, "SEC_TYPE", "ext2", sizeof("ext2"));
 162 }
 163
 164 /*
 165  * Check to see if a filesystem is in /proc/filesystems.
 166  * Returns 1 if found, 0 if not
 167  */
 168 static int fs_proc_check(const char *fs_name)
 169 {
 170         FILE    *f;
 171         char    buf[80], *cp, *t;
 172
 173         f = fopen("/proc/filesystems", "r");
 174         if (!f)
 175                 return (0);
 176         while (!feof(f)) {
 177                 if (!fgets(buf, sizeof(buf), f))
 178                         break;
 179                 cp = buf;
 180                 if (!isspace(*cp)) {
 181                         while (*cp && !isspace(*cp))
 182                                 cp++;
 183                 }
 184                 while (*cp && isspace(*cp))
 185                         cp++;
 186                 if ((t = strchr(cp, '\n')) != NULL)
 187                         *t = 0;
 188                 if ((t = strchr(cp, '\t')) != NULL)
 189                         *t = 0;
 190                 if ((t = strchr(cp, ' ')) != NULL)
 191                         *t = 0;
 192                 if (!strcmp(fs_name, cp)) {
 193                         fclose(f);
 194                         return (1);
 195                 }
 196         }
 197         fclose(f);
 198         return (0);
 199 }
 200
 201 /*
 202  * Check to see if a filesystem is available as a module
 203  * Returns 1 if found, 0 if not
 204  */
 205 static int check_for_modules(const char *fs_name)
 206 {
 207 #ifdef __linux__
 208         struct utsname  uts;
 209         FILE            *f;
 210         char            buf[1024], *cp;
 211         int             namesz;
 212
 213         if (uname(&uts))
 214                 return (0);
 215         snprintf(buf, sizeof(buf), "/lib/modules/%s/modules.dep", uts.release);
 216
 217         f = fopen(buf, "r");
 218         if (!f)
 219                 return (0);
 220
 221         namesz = strlen(fs_name);
 222
 223         while (!feof(f)) {
 224                 if (!fgets(buf, sizeof(buf), f))
 225                         break;
 226                 if ((cp = strchr(buf, ':')) != NULL)
 227                         *cp = 0;
 228                 else
 229                         continue;
 230                 if ((cp = strrchr(buf, '/')) != NULL)
 231                         cp++;
 232                 else
 233                         cp = buf;
 234                 if (!strncmp(cp, fs_name, namesz) &&
 235                     (!strcmp(cp + namesz, ".ko") ||
 236                      !strcmp(cp + namesz, ".ko.gz"))) {
 237                         fclose(f);
 238                         return (1);
 239                 }
 240         }
 241         fclose(f);
 242 #endif
 243         return (0);
 244 }
 245
 246 static int linux_version_code(void)
 247 {
 248 #ifdef __linux__
 249         struct utsname  ut;
 250         static int      version_code = -1;
 251         int             major, minor, rev;
 252         char            *endptr;
 253         const char      *cp;
 254
 255         if (version_code > 0)
 256                 return version_code;
 257
 258         if (uname(&ut))
 259                 return 0;
 260         cp = ut.release;
 261
 262         major = strtol(cp, &endptr, 10);
 263         if (cp == endptr || *endptr != '.')
 264                 return 0;
 265         cp = endptr + 1;
 266         minor = strtol(cp, &endptr, 10);
 267         if (cp == endptr || *endptr != '.')
 268                 return 0;
 269         cp = endptr + 1;
 270         rev = strtol(cp, &endptr, 10);
 271         if (cp == endptr)
 272                 return 0;
 273         version_code = (((major * 256) + minor) * 256) + rev;
 274         return version_code;
 275 #else
 276         return 0;
 277 #endif
 278 }
 279
 280 #define EXT4_SUPPORTS_EXT2 (2 * 65536 + 6*256 + 29)
 281
 282 static int system_supports_ext2(void)
 283 {
 284         static time_t   last_check = 0;
 285         static int      ret = -1;
 286         time_t          now = time(0);
 287
 288         if (ret != -1 || (now - last_check) < 5)
 289                 return ret;
 290         last_check = now;
 291         ret = (fs_proc_check("ext2") || check_for_modules("ext2"));
 292         return ret;
 293 }
 294
 295 static int system_supports_ext4(void)
 296 {
 297         static time_t   last_check = 0;
 298         static int      ret = -1;
 299         time_t          now = time(0);
 300
 301         if (ret != -1 || (now - last_check) < 5)
 302                 return ret;
 303         last_check = now;
 304         ret = (fs_proc_check("ext4") || check_for_modules("ext4"));
 305         return ret;
 306 }
 307
 308 static int system_supports_ext4dev(void)
 309 {
 310         static time_t   last_check = 0;
 311         static int      ret = -1;
 312         time_t          now = time(0);
 313
 314         if (ret != -1 || (now - last_check) < 5)
 315                 return ret;
 316         last_check = now;
 317         ret = (fs_proc_check("ext4dev") || check_for_modules("ext4dev"));
 318         return ret;
 319 }
 320
 321 static int probe_ext4dev(struct blkid_probe *probe,
 322                          struct blkid_magic *id,
 323                          unsigned char *buf)
 324 {
 325         struct ext2_super_block *es;
 326         es = (struct ext2_super_block *)buf;
 327
 328         /* Distinguish from jbd */
 329         if (blkid_le32(es->s_feature_incompat) &
 330             EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
 331                 return -BLKID_ERR_PARAM;
 332
 333         /*
 334          * If the filesystem does not have a journal and ext2 and ext4
 335          * is not present, then force this to be detected as an
 336          * ext4dev filesystem.
 337          */
 338         if (!(blkid_le32(es->s_feature_compat) &
 339               EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
 340             !system_supports_ext2() && !system_supports_ext4() &&
 341             system_supports_ext4dev() &&
 342             linux_version_code() >= EXT4_SUPPORTS_EXT2)
 343                 goto force_ext4dev;
 344
 345         /*
 346          * If the filesystem is marked as OK for use by in-development
 347          * filesystem code, but ext4dev is not supported, and ext4 is,
 348          * then don't call ourselves ext4dev, since we should be
 349          * detected as ext4 in that case.
 350          *
 351          * If the filesystem is marked as in use by production
 352          * filesystem, then it can only be used by ext4 and NOT by
 353          * ext4dev, so always disclaim we are ext4dev in that case.
 354          */
 355         if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) {
 356                 if (!system_supports_ext4dev() && system_supports_ext4())
 357                         return -BLKID_ERR_PARAM;
 358         } else
 359                 return -BLKID_ERR_PARAM;
 360
 361 force_ext4dev:
 362         get_ext2_info(probe->dev, id, buf);
 363         return 0;
 364 }
 365
 366 static int probe_ext4(struct blkid_probe *probe, struct blkid_magic *id,
 367                       unsigned char *buf)
 368 {
 369         struct ext2_super_block *es;
 370         es = (struct ext2_super_block *)buf;
 371
 372         /* Distinguish from jbd */
 373         if (blkid_le32(es->s_feature_incompat) &
 374             EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
 375                 return -BLKID_ERR_PARAM;
 376
 377         /*
 378          * If the filesystem does not have a journal and ext2 is not
 379          * present, then force this to be detected as an ext2
 380          * filesystem.
 381          */
 382         if (!(blkid_le32(es->s_feature_compat) &
 383               EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
 384             !system_supports_ext2() && system_supports_ext4() &&
 385             linux_version_code() >= EXT4_SUPPORTS_EXT2)
 386                 goto force_ext4;
 387
 388         /* Ext4 has at least one feature which ext3 doesn't understand */
 389         if (!(blkid_le32(es->s_feature_ro_compat) &
 390               EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) &&
 391             !(blkid_le32(es->s_feature_incompat) &
 392               EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
 393                 return -BLKID_ERR_PARAM;
 394
 395 force_ext4:
 396         /*
 397          * If the filesystem is a OK for use by in-development
 398          * filesystem code, and ext4dev is supported or ext4 is not
 399          * supported, then don't call ourselves ext4, so we can redo
 400          * the detection and mark the filesystem as ext4dev.
 401          *
 402          * If the filesystem is marked as in use by production
 403          * filesystem, then it can only be used by ext4 and NOT by
 404          * ext4dev.
 405          */
 406         if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) {
 407                 if (system_supports_ext4dev() || !system_supports_ext4())
 408                         return -BLKID_ERR_PARAM;
 409         }
 410         get_ext2_info(probe->dev, id, buf);
 411         return 0;
 412 }
 413
 414 static int probe_ext3(struct blkid_probe *probe, struct blkid_magic *id,
 415                       unsigned char *buf)
 416 {
 417         struct ext2_super_block *es;
 418         es = (struct ext2_super_block *)buf;
 419
 420         /* ext3 requires journal */
 421         if (!(blkid_le32(es->s_feature_compat) &
 422               EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 423                 return -BLKID_ERR_PARAM;
 424
 425         /* Any features which ext3 doesn't understand */
 426         if ((blkid_le32(es->s_feature_ro_compat) &
 427              EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) ||
 428             (blkid_le32(es->s_feature_incompat) &
 429              EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
 430                 return -BLKID_ERR_PARAM;
 431
 432         get_ext2_info(probe->dev, id, buf);
 433         return 0;
 434 }
 435
 436 static int probe_ext2(struct blkid_probe *probe, struct blkid_magic *id,
 437                       unsigned char *buf)
 438 {
 439         struct ext2_super_block *es;
 440
 441         es = (struct ext2_super_block *)buf;
 442
 443         /* Distinguish between ext3 and ext2 */
 444         if ((blkid_le32(es->s_feature_compat) &
 445               EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 446                 return -BLKID_ERR_PARAM;
 447
 448         /* Any features which ext2 doesn't understand */
 449         if ((blkid_le32(es->s_feature_ro_compat) &
 450              EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) ||
 451             (blkid_le32(es->s_feature_incompat) &
 452              EXT2_FEATURE_INCOMPAT_UNSUPPORTED))
 453                 return -BLKID_ERR_PARAM;
 454
 455         /*
 456          * If ext2 is not present, but ext4 or ext4dev are, then
 457          * disclaim we are ext2
 458          */
 459         if (!system_supports_ext2() &&
 460             (system_supports_ext4() || system_supports_ext4dev()) &&
 461             linux_version_code() >= EXT4_SUPPORTS_EXT2)
 462                 return -BLKID_ERR_PARAM;
 463
 464         get_ext2_info(probe->dev, id, buf);
 465         return 0;
 466 }
 467
 468 static int probe_jbd(struct blkid_probe *probe, struct blkid_magic *id,
 469                      unsigned char *buf)
 470 {
 471         struct ext2_super_block *es = (struct ext2_super_block *) buf;
 472
 473         if (!(blkid_le32(es->s_feature_incompat) &
 474               EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
 475                 return -BLKID_ERR_PARAM;
 476
 477         get_ext2_info(probe->dev, id, buf);
 478
 479         return 0;
 480 }
 481
 482 #define FAT_ATTR_VOLUME_ID              0x08
 483 #define FAT_ATTR_DIR                    0x10
 484 #define FAT_ATTR_LONG_NAME              0x0f
 485 #define FAT_ATTR_MASK                   0x3f
 486 #define FAT_ENTRY_FREE                  0xe5
 487
 488 static const char *no_name = "NO NAME    ";
 489
 490 static unsigned char *search_fat_label(struct vfat_dir_entry *dir, int count)
 491 {
 492         int i;
 493
 494         for (i = 0; i < count; i++) {
 495                 if (dir[i].name[0] == 0x00)
 496                         break;
 497
 498                 if ((dir[i].name[0] == FAT_ENTRY_FREE) ||
 499                     (dir[i].cluster_high != 0 || dir[i].cluster_low != 0) ||
 500                     ((dir[i].attr & FAT_ATTR_MASK) == FAT_ATTR_LONG_NAME))
 501                         continue;
 502
 503                 if ((dir[i].attr & (FAT_ATTR_VOLUME_ID | FAT_ATTR_DIR)) ==
 504                     FAT_ATTR_VOLUME_ID) {
 505                         return dir[i].name;
 506                 }
 507         }
 508         return 0;
 509 }
 510
 511 /* FAT label extraction from the root directory taken from Kay
 512  * Sievers's volume_id library */
 513 static int probe_fat(struct blkid_probe *probe,
 514                       struct blkid_magic *id __BLKID_ATTR((unused)),
 515                       unsigned char *buf)
 516 {
 517         struct vfat_super_block *vs = (struct vfat_super_block *) buf;
 518         struct msdos_super_block *ms = (struct msdos_super_block *) buf;
 519         struct vfat_dir_entry *dir;
 520         char serno[10];
 521         const unsigned char *label = 0, *vol_label = 0, *tmp;
 522         unsigned char   *vol_serno;
 523         int label_len = 0, maxloop = 100;
 524         __u16 sector_size, dir_entries, reserved;
 525         __u32 sect_count, fat_size, dir_size, cluster_count, fat_length;
 526         __u32 buf_size, start_data_sect, next, root_start, root_dir_entries;
 527
 528         /* sector size check */
 529         tmp = (unsigned char *)&ms->ms_sector_size;
 530         sector_size = tmp[0] + (tmp[1] << 8);
 531         if (sector_size != 0x200 && sector_size != 0x400 &&
 532             sector_size != 0x800 && sector_size != 0x1000)
 533                 return 1;
 534
 535         tmp = (unsigned char *)&ms->ms_dir_entries;
 536         dir_entries = tmp[0] + (tmp[1] << 8);
 537         reserved =  blkid_le16(ms->ms_reserved);
 538         tmp = (unsigned char *)&ms->ms_sectors;
 539         sect_count = tmp[0] + (tmp[1] << 8);
 540         if (sect_count == 0)
 541                 sect_count = blkid_le32(ms->ms_total_sect);
 542
 543         fat_length = blkid_le16(ms->ms_fat_length);
 544         if (fat_length == 0)
 545                 fat_length = blkid_le32(vs->vs_fat32_length);
 546
 547         fat_size = fat_length * ms->ms_fats;
 548         dir_size = ((dir_entries * sizeof(struct vfat_dir_entry)) +
 549                         (sector_size-1)) / sector_size;
 550
 551         cluster_count = sect_count - (reserved + fat_size + dir_size);
 552         if (ms->ms_cluster_size == 0)
 553                 return 1;
 554         cluster_count /= ms->ms_cluster_size;
 555
 556         if (cluster_count > FAT32_MAX)
 557                 return 1;
 558
 559         if (ms->ms_fat_length) {
 560                 /* the label may be an attribute in the root directory */
 561                 root_start = (reserved + fat_size) * sector_size;
 562                 root_dir_entries = vs->vs_dir_entries[0] +
 563                         (vs->vs_dir_entries[1] << 8);
 564
 565                 buf_size = root_dir_entries * sizeof(struct vfat_dir_entry);
 566                 dir = (struct vfat_dir_entry *) get_buffer(probe, root_start,
 567                                                            buf_size);
 568                 if (dir)
 569                         vol_label = search_fat_label(dir, root_dir_entries);
 570
 571                 if (!vol_label || !memcmp(vol_label, no_name, 11))
 572                         vol_label = ms->ms_label;
 573                 vol_serno = ms->ms_serno;
 574
 575                 blkid_set_tag(probe->dev, "SEC_TYPE", "msdos",
 576                               sizeof("msdos"));
 577         } else {
 578                 /* Search the FAT32 root dir for the label attribute */
 579                 buf_size = vs->vs_cluster_size * sector_size;
 580                 start_data_sect = reserved + fat_size;
 581
 582                 next = blkid_le32(vs->vs_root_cluster);
 583                 while (next && --maxloop) {
 584                         __u32 next_sect_off;
 585                         __u64 next_off, fat_entry_off;
 586                         int count;
 587
 588                         next_sect_off = (next - 2) * vs->vs_cluster_size;
 589                         next_off = (__u64) (start_data_sect + next_sect_off) *
 590                                 sector_size;
 591
 592                         dir = (struct vfat_dir_entry *)
 593                                 get_buffer(probe, next_off, buf_size);
 594                         if (dir == NULL)
 595                                 break;
 596
 597                         count = buf_size / sizeof(struct vfat_dir_entry);
 598
 599                         vol_label = search_fat_label(dir, count);
 600                         if (vol_label)
 601                                 break;
 602
 603                         /* get FAT entry */
 604                         fat_entry_off =
 605                                 ((unsigned int) reserved *
 606                                  (unsigned int) sector_size) +
 607                                 (next * sizeof(__u32));
 608                         buf = get_buffer(probe, fat_entry_off, buf_size);
 609                         if (buf == NULL)
 610                                 break;
 611
 612                         /* set next cluster */
 613                         next = blkid_le32(*((__u32 *) buf) & 0x0fffffff);
 614                 }
 615
 616                 if (!vol_label || !memcmp(vol_label, no_name, 11))
 617                         vol_label = vs->vs_label;
 618                 vol_serno = vs->vs_serno;
 619         }
 620
 621         if (vol_label && memcmp(vol_label, no_name, 11)) {
 622                 if ((label_len = figure_label_len(vol_label, 11)))
 623                         label = vol_label;
 624         }
 625
 626         /* We can't just print them as %04X, because they are unaligned */
 627         sprintf(serno, "%02X%02X-%02X%02X", vol_serno[3], vol_serno[2],
 628                 vol_serno[1], vol_serno[0]);
 629
 630         blkid_set_tag(probe->dev, "LABEL", (const char *) label, label_len);
 631         blkid_set_tag(probe->dev, "UUID", serno, sizeof(serno)-1);
 632
 633         return 0;
 634 }
 635
 636 /*
 637  * The FAT filesystem could be without a magic string in superblock
 638  * (e.g. old floppies).  This heuristic for FAT detection is inspired
 639  * by http://vrfy.org/projects/volume_id/ and Linux kernel.
 640  * [7-Jul-2005, Karel Zak <kzak@redhat.com>]
 641  */
 642 static int probe_fat_nomagic(struct blkid_probe *probe,
 643                              struct blkid_magic *id __BLKID_ATTR((unused)),
 644                              unsigned char *buf)
 645 {
 646         struct msdos_super_block *ms;
 647
 648         ms = (struct msdos_super_block *)buf;
 649
 650         /* heads check */
 651         if (ms->ms_heads == 0)
 652                 return 1;
 653
 654         /* cluster size check*/
 655         if (ms->ms_cluster_size == 0 ||
 656             (ms->ms_cluster_size & (ms->ms_cluster_size-1)))
 657                 return 1;
 658
 659         /* media check */
 660         if (ms->ms_media < 0xf8 && ms->ms_media != 0xf0)
 661                 return 1;
 662
 663         /* fat counts(Linux kernel expects at least 1 FAT table) */
 664         if (!ms->ms_fats)
 665                 return 1;
 666
 667         /*
 668          * OS/2 and apparently DFSee will place a FAT12/16-like
 669          * pseudo-superblock in the first 512 bytes of non-FAT
 670          * filesystems --- at least JFS and HPFS, and possibly others.
 671          * So we explicitly check for those filesystems at the
 672          * FAT12/16 filesystem magic field identifier, and if they are
 673          * present, we rule this out as a FAT filesystem, despite the
 674          * FAT-like pseudo-header.
 675          */
 676         if ((memcmp(ms->ms_magic, "JFS     ", 8) == 0) ||
 677             (memcmp(ms->ms_magic, "HPFS    ", 8) == 0))
 678                 return 1;
 679
 680         return probe_fat(probe, id, buf);
 681 }
 682
 683 static int probe_ntfs(struct blkid_probe *probe,
 684                       struct blkid_magic *id __BLKID_ATTR((unused)),
 685                       unsigned char *buf)
 686 {
 687         struct ntfs_super_block *ns;
 688         struct master_file_table_record *mft;
 689         struct file_attribute *attr;
 690         char            uuid_str[17], label_str[129], *cp;
 691         int             bytes_per_sector, sectors_per_cluster;
 692         int             mft_record_size, attr_off, attr_len;
 693         unsigned int    i, attr_type, val_len;
 694         int             val_off;
 695         __u64           nr_clusters;
 696         blkid_loff_t off;
 697         unsigned char *buf_mft, *val;
 698
 699         ns = (struct ntfs_super_block *) buf;
 700
 701         bytes_per_sector = ns->bios_parameter_block[0] +
 702                 (ns->bios_parameter_block[1]  << 8);
 703         sectors_per_cluster = ns->bios_parameter_block[2];
 704
 705         if ((bytes_per_sector < 512) || (sectors_per_cluster == 0))
 706                 return 1;
 707
 708         if (ns->cluster_per_mft_record < 0)
 709                 mft_record_size = 1 << (0-ns->cluster_per_mft_record);
 710         else
 711                 mft_record_size = ns->cluster_per_mft_record *
 712                         sectors_per_cluster * bytes_per_sector;
 713         nr_clusters = blkid_le64(ns->number_of_sectors) / sectors_per_cluster;
 714
 715         if ((blkid_le64(ns->mft_cluster_location) > nr_clusters) ||
 716             (blkid_le64(ns->mft_mirror_cluster_location) > nr_clusters))
 717                 return 1;
 718
 719         off = blkid_le64(ns->mft_mirror_cluster_location) *
 720                 bytes_per_sector * sectors_per_cluster;
 721
 722         buf_mft = get_buffer(probe, off, mft_record_size);
 723         if (!buf_mft)
 724                 return 1;
 725
 726         if (memcmp(buf_mft, "FILE", 4))
 727                 return 1;
 728
 729         off = blkid_le64(ns->mft_cluster_location) * bytes_per_sector *
 730                 sectors_per_cluster;
 731
 732         buf_mft = get_buffer(probe, off, mft_record_size);
 733         if (!buf_mft)
 734                 return 1;
 735
 736         if (memcmp(buf_mft, "FILE", 4))
 737                 return 1;
 738
 739         off += MFT_RECORD_VOLUME * mft_record_size;
 740
 741         buf_mft = get_buffer(probe, off, mft_record_size);
 742         if (!buf_mft)
 743                 return 1;
 744
 745         if (memcmp(buf_mft, "FILE", 4))
 746                 return 1;
 747
 748         mft = (struct master_file_table_record *) buf_mft;
 749
 750         attr_off = blkid_le16(mft->attrs_offset);
 751         label_str[0] = 0;
 752
 753         while (1) {
 754                 attr = (struct file_attribute *) (buf_mft + attr_off);
 755                 attr_len = blkid_le16(attr->len);
 756                 attr_type = blkid_le32(attr->type);
 757                 val_off = blkid_le16(attr->value_offset);
 758                 val_len = blkid_le32(attr->value_len);
 759
 760                 attr_off += attr_len;
 761
 762                 if ((attr_off > mft_record_size) ||
 763                     (attr_len == 0))
 764                         break;
 765
 766                 if (attr_type == MFT_RECORD_ATTR_END)
 767                         break;
 768
 769                 if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
 770                         if (val_len > sizeof(label_str))
 771                                 val_len = sizeof(label_str)-1;
 772
 773                         for (i=0, cp=label_str; i < val_len; i+=2,cp++) {
 774                                 val = ((__u8 *) attr) + val_off + i;
 775                                 *cp = val[0];
 776                                 if (val[1])
 777                                         *cp = '?';
 778                         }
 779                         *cp = 0;
 780                 }
 781         }
 782
 783         sprintf(uuid_str, "%016llX", blkid_le64(ns->volume_serial));
 784         blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
 785         if (label_str[0])
 786                 blkid_set_tag(probe->dev, "LABEL", label_str, 0);
 787         return 0;
 788 }
 789
 790
 791 static int probe_xfs(struct blkid_probe *probe,
 792                      struct blkid_magic *id __BLKID_ATTR((unused)),
 793                      unsigned char *buf)
 794 {
 795         struct xfs_super_block *xs;
 796         const char *label = 0;
 797
 798         xs = (struct xfs_super_block *)buf;
 799
 800         if (strlen(xs->xs_fname))
 801                 label = xs->xs_fname;
 802         blkid_set_tag(probe->dev, "LABEL", label, sizeof(xs->xs_fname));
 803         set_uuid(probe->dev, xs->xs_uuid, 0);
 804         return 0;
 805 }
 806
 807 static int probe_reiserfs(struct blkid_probe *probe,
 808                           struct blkid_magic *id, unsigned char *buf)
 809 {
 810         struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
 811         unsigned int blocksize;
 812         const char *label = 0;
 813
 814         blocksize = blkid_le16(rs->rs_blocksize);
 815
 816         /* The blocksize must be at least 1k */
 817         if ((blocksize >> 10) == 0)
 818                 return -BLKID_ERR_PARAM;
 819
 820         /* If the superblock is inside the journal, we have the wrong one */
 821         if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
 822                 return -BLKID_ERR_BIG;
 823
 824         /* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
 825         if (id->bim_magic[6] == '2' || id->bim_magic[6] == '3') {
 826                 if (strlen(rs->rs_label))
 827                         label = rs->rs_label;
 828                 set_uuid(probe->dev, rs->rs_uuid, 0);
 829         }
 830         blkid_set_tag(probe->dev, "LABEL", label, sizeof(rs->rs_label));
 831
 832         return 0;
 833 }
 834
 835 static int probe_reiserfs4(struct blkid_probe *probe,
 836                            struct blkid_magic *id __BLKID_ATTR((unused)),
 837                            unsigned char *buf)
 838 {
 839         struct reiser4_super_block *rs4 = (struct reiser4_super_block *) buf;
 840         const unsigned char *label = 0;
 841
 842         if (strlen((char *) rs4->rs4_label))
 843                 label = rs4->rs4_label;
 844         set_uuid(probe->dev, rs4->rs4_uuid, 0);
 845         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 846                       sizeof(rs4->rs4_label));
 847
 848         return 0;
 849 }
 850
 851 static int probe_jfs(struct blkid_probe *probe,
 852                      struct blkid_magic *id __BLKID_ATTR((unused)),
 853                      unsigned char *buf)
 854 {
 855         struct jfs_super_block *js;
 856         const char *label = 0;
 857
 858         js = (struct jfs_super_block *)buf;
 859
 860         if (blkid_le32(js->js_bsize) != (1U << blkid_le16(js->js_l2bsize)))
 861                 return 1;
 862
 863         if (blkid_le32(js->js_pbsize) != (1U << blkid_le16(js->js_l2pbsize)))
 864                 return 1;
 865
 866         if ((blkid_le16(js->js_l2bsize) - blkid_le16(js->js_l2pbsize)) !=
 867             blkid_le16(js->js_l2bfactor))
 868                 return 1;
 869
 870         if (strlen((char *) js->js_label))
 871                 label = (char *) js->js_label;
 872         blkid_set_tag(probe->dev, "LABEL", label, sizeof(js->js_label));
 873         set_uuid(probe->dev, js->js_uuid, 0);
 874         return 0;
 875 }
 876
 877 static int probe_zfs(struct blkid_probe *probe __BLKID_ATTR((unused)),
 878                      struct blkid_magic *id __BLKID_ATTR((unused)),
 879                      unsigned char *buf __BLKID_ATTR((unused)))
 880 {
 881 #if 0
 882         char *vdev_label;
 883         const char *pool_name = 0;
 884
 885         /* read nvpair data for pool name, pool GUID (complex) */
 886         blkid_set_tag(probe->dev, "LABEL", pool_name, sizeof(pool_name));
 887         set_uuid(probe->dev, pool_guid, 0);
 888 #endif
 889         return 0;
 890 }
 891
 892 static int probe_luks(struct blkid_probe *probe,
 893                        struct blkid_magic *id __BLKID_ATTR((unused)),
 894                        unsigned char *buf)
 895 {
 896         char uuid[41];
 897
 898         /* 168 is the offset to the 40 character uuid:
 899          * http://luks.endorphin.org/LUKS-on-disk-format.pdf */
 900         strncpy(uuid, (char *) buf+168, 40);
 901         uuid[40] = 0;
 902         blkid_set_tag(probe->dev, "UUID", uuid, 40);
 903         return 0;
 904 }
 905
 906 static int probe_romfs(struct blkid_probe *probe,
 907                        struct blkid_magic *id __BLKID_ATTR((unused)),
 908                        unsigned char *buf)
 909 {
 910         struct romfs_super_block *ros;
 911         const char *label = 0;
 912
 913         ros = (struct romfs_super_block *)buf;
 914
 915         if (strlen((char *) ros->ros_volume))
 916                 label = (char *) ros->ros_volume;
 917         blkid_set_tag(probe->dev, "LABEL", label, 0);
 918         return 0;
 919 }
 920
 921 static int probe_cramfs(struct blkid_probe *probe,
 922                         struct blkid_magic *id __BLKID_ATTR((unused)),
 923                         unsigned char *buf)
 924 {
 925         struct cramfs_super_block *csb;
 926         const char *label = 0;
 927
 928         csb = (struct cramfs_super_block *)buf;
 929
 930         if (strlen((char *) csb->name))
 931                 label = (char *) csb->name;
 932         blkid_set_tag(probe->dev, "LABEL", label, 0);
 933         return 0;
 934 }
 935
 936 static int probe_swap0(struct blkid_probe *probe,
 937                        struct blkid_magic *id __BLKID_ATTR((unused)),
 938                        unsigned char *buf __BLKID_ATTR((unused)))
 939 {
 940         blkid_set_tag(probe->dev, "UUID", 0, 0);
 941         blkid_set_tag(probe->dev, "LABEL", 0, 0);
 942         return 0;
 943 }
 944
 945 static int probe_swap1(struct blkid_probe *probe,
 946                        struct blkid_magic *id,
 947                        unsigned char *buf __BLKID_ATTR((unused)))
 948 {
 949         struct swap_id_block *sws;
 950
 951         probe_swap0(probe, id, buf);
 952         /*
 953          * Version 1 swap headers are always located at offset of 1024
 954          * bytes, although the swap signature itself is located at the
 955          * end of the page (which may vary depending on hardware
 956          * pagesize).
 957          */
 958         sws = (struct swap_id_block *) get_buffer(probe, 1024, 1024);
 959         if (!sws)
 960                 return 1;
 961
 962         /* check for wrong version or zeroed pagecount, for sanity */
 963         if (!memcmp(id->bim_magic, "SWAPSPACE2", id->bim_len) &&
 964                         (sws->sws_version != 1 || sws->sws_lastpage == 0))
 965                 return 1;
 966
 967         /* arbitrary sanity check.. is there any garbage down there? */
 968         if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0)  {
 969                 if (sws->sws_volume[0])
 970                         blkid_set_tag(probe->dev, "LABEL", sws->sws_volume,
 971                                       sizeof(sws->sws_volume));
 972                 if (sws->sws_uuid[0])
 973                         set_uuid(probe->dev, sws->sws_uuid, 0);
 974         }
 975         return 0;
 976 }
 977
 978 static int probe_iso9660(struct blkid_probe *probe,
 979                          struct blkid_magic *id __BLKID_ATTR((unused)),
 980                          unsigned char *buf)
 981 {
 982         struct iso_volume_descriptor *iso;
 983         const unsigned char *label;
 984
 985         iso = (struct iso_volume_descriptor *) buf;
 986         label = iso->volume_id;
 987
 988         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 989                       figure_label_len(label, 32));
 990         return 0;
 991 }
 992
 993
 994 static const char
 995 *udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
 996                  "NSR03", "TEA01", 0 };
 997
 998 static int probe_udf(struct blkid_probe *probe,
 999                      struct blkid_magic *id __BLKID_ATTR((unused)),
1000                      unsigned char *buf __BLKID_ATTR((unused)))
1001 {
1002         int j, bs;
1003         struct iso_volume_descriptor *isosb;
1004         const char ** m;
1005
1006         /* determine the block size by scanning in 2K increments
1007            (block sizes larger than 2K will be null padded) */
1008         for (bs = 1; bs < 16; bs++) {
1009                 isosb = (struct iso_volume_descriptor *)
1010                         get_buffer(probe, (blkid_loff_t) bs*2048+32768,
1011                                    sizeof(*isosb));
1012                 if (!isosb)
1013                         return 1;
1014                 if (isosb->vd_id[0])
1015                         break;
1016         }
1017
1018         /* Scan up to another 64 blocks looking for additional VSD's */
1019         for (j = 1; j < 64; j++) {
1020                 if (j > 1) {
1021                         isosb = (struct iso_volume_descriptor *)
1022                                 get_buffer(probe, j*bs*2048+32768,
1023                                            sizeof(*isosb));
1024                         if (!isosb)
1025                                 return 1;
1026                 }
1027                 /* If we find NSR0x then call it udf:
1028                    NSR01 for UDF 1.00
1029                    NSR02 for UDF 1.50
1030                    NSR03 for UDF 2.00 */
1031                 if (!memcmp(isosb->vd_id, "NSR0", 4))
1032                         return probe_iso9660(probe, id, buf);
1033                 for (m = udf_magic; *m; m++)
1034                         if (!memcmp(*m, isosb->vd_id, 5))
1035                                 break;
1036                 if (*m == 0)
1037                         return 1;
1038         }
1039         return 1;
1040 }
1041
1042 static int probe_ocfs(struct blkid_probe *probe,
1043                       struct blkid_magic *id __BLKID_ATTR((unused)),
1044                       unsigned char *buf)
1045 {
1046         struct ocfs_volume_header ovh;
1047         struct ocfs_volume_label ovl;
1048         __u32 major;
1049
1050         memcpy(&ovh, buf, sizeof(ovh));
1051         memcpy(&ovl, buf+512, sizeof(ovl));
1052
1053         major = ocfsmajor(ovh);
1054         if (major == 1)
1055                 blkid_set_tag(probe->dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
1056         else if (major >= 9)
1057                 blkid_set_tag(probe->dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
1058
1059         blkid_set_tag(probe->dev, "LABEL", ovl.label, ocfslabellen(ovl));
1060         blkid_set_tag(probe->dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
1061         set_uuid(probe->dev, ovl.vol_id, 0);
1062         return 0;
1063 }
1064
1065 static int probe_ocfs2(struct blkid_probe *probe,
1066                        struct blkid_magic *id __BLKID_ATTR((unused)),
1067                        unsigned char *buf)
1068 {
1069         struct ocfs2_super_block *osb;
1070
1071         osb = (struct ocfs2_super_block *)buf;
1072
1073         blkid_set_tag(probe->dev, "LABEL", osb->s_label, sizeof(osb->s_label));
1074         set_uuid(probe->dev, osb->s_uuid, 0);
1075         return 0;
1076 }
1077
1078 static int probe_oracleasm(struct blkid_probe *probe,
1079                            struct blkid_magic *id __BLKID_ATTR((unused)),
1080                            unsigned char *buf)
1081 {
1082         struct oracle_asm_disk_label *dl;
1083
1084         dl = (struct oracle_asm_disk_label *)buf;
1085
1086         blkid_set_tag(probe->dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
1087         return 0;
1088 }
1089
1090 static int probe_gfs(struct blkid_probe *probe,
1091                      struct blkid_magic *id __BLKID_ATTR((unused)),
1092                      unsigned char *buf)
1093 {
1094         struct gfs2_sb *sbd;
1095         const char *label = 0;
1096
1097         sbd = (struct gfs2_sb *)buf;
1098
1099         if (blkid_be32(sbd->sb_fs_format) == GFS_FORMAT_FS &&
1100             blkid_be32(sbd->sb_multihost_format) == GFS_FORMAT_MULTI)
1101         {
1102                 blkid_set_tag(probe->dev, "UUID", 0, 0);
1103
1104                 if (strlen(sbd->sb_locktable))
1105                         label = sbd->sb_locktable;
1106                 blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
1107                 return 0;
1108         }
1109         return 1;
1110 }
1111
1112 static int probe_gfs2(struct blkid_probe *probe,
1113                      struct blkid_magic *id __BLKID_ATTR((unused)),
1114                      unsigned char *buf)
1115 {
1116         struct gfs2_sb *sbd;
1117         const char *label = 0;
1118
1119         sbd = (struct gfs2_sb *)buf;
1120
1121         if (blkid_be32(sbd->sb_fs_format) == GFS2_FORMAT_FS &&
1122             blkid_be32(sbd->sb_multihost_format) == GFS2_FORMAT_MULTI)
1123         {
1124                 blkid_set_tag(probe->dev, "UUID", 0, 0);
1125
1126                 if (strlen(sbd->sb_locktable))
1127                         label = sbd->sb_locktable;
1128                 blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
1129                 return 0;
1130         }
1131         return 1;
1132 }
1133
1134 static void unicode_16be_to_utf8(unsigned char *str, int out_len,
1135                                  const unsigned char *buf, int in_len)
1136 {
1137         int i, j;
1138         unsigned int c;
1139
1140         for (i = j = 0; i + 2 <= in_len; i += 2) {
1141                 c = (buf[i] << 8) | buf[i+1];
1142                 if (c == 0) {
1143                         str[j] = '\0';
1144                         break;
1145                 } else if (c < 0x80) {
1146                         if (j+1 >= out_len)
1147                                 break;
1148                         str[j++] = (unsigned char) c;
1149                 } else if (c < 0x800) {
1150                         if (j+2 >= out_len)
1151                                 break;
1152                         str[j++] = (unsigned char) (0xc0 | (c >> 6));
1153                         str[j++] = (unsigned char) (0x80 | (c & 0x3f));
1154                 } else {
1155                         if (j+3 >= out_len)
1156                                 break;
1157                         str[j++] = (unsigned char) (0xe0 | (c >> 12));
1158                         str[j++] = (unsigned char) (0x80 | ((c >> 6) & 0x3f));
1159                         str[j++] = (unsigned char) (0x80 | (c & 0x3f));
1160                 }
1161         }
1162         str[j] = '\0';
1163 }
1164
1165 static void unicode_16le_to_utf8(unsigned char *str, int out_len,
1166                                  const unsigned char *buf, int in_len)
1167 {
1168         int i, j;
1169         unsigned int c;
1170
1171         for (i = j = 0; i + 2 <= in_len; i += 2) {
1172                 c = (buf[i+1] << 8) | buf[i];
1173                 if (c == 0) {
1174                         str[j] = '\0';
1175                         break;
1176                 } else if (c < 0x80) {
1177                         if (j+1 >= out_len)
1178                                 break;
1179                         str[j++] = (unsigned char) c;
1180                 } else if (c < 0x800) {
1181                         if (j+2 >= out_len)
1182                                 break;
1183                         str[j++] = (unsigned char) (0xc0 | (c >> 6));
1184                         str[j++] = (unsigned char) (0x80 | (c & 0x3f));
1185                 } else {
1186                         if (j+3 >= out_len)
1187                                 break;
1188                         str[j++] = (unsigned char) (0xe0 | (c >> 12));
1189                         str[j++] = (unsigned char) (0x80 | ((c >> 6) & 0x3f));
1190                         str[j++] = (unsigned char) (0x80 | (c & 0x3f));
1191                 }
1192         }
1193         str[j] = '\0';
1194 }
1195
1196 static int probe_hfs(struct blkid_probe *probe __BLKID_ATTR((unused)),
1197                          struct blkid_magic *id __BLKID_ATTR((unused)),
1198                          unsigned char *buf)
1199 {
1200         struct hfs_mdb *hfs = (struct hfs_mdb *)buf;
1201         char    uuid_str[17];
1202         __u64   uuid;
1203
1204         if ((memcmp(hfs->embed_sig, "H+", 2) == 0) ||
1205             (memcmp(hfs->embed_sig, "HX", 2) == 0))
1206                 return 1;       /* Not hfs, but an embedded HFS+ */
1207
1208         memcpy(&uuid, hfs->finder_info.id, 8);
1209         uuid = blkid_le64(uuid);
1210         if (uuid) {
1211                 sprintf(uuid_str, "%016llX", uuid);
1212                 blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
1213         }
1214         blkid_set_tag(probe->dev, "LABEL", (char *)hfs->label, hfs->label_len);
1215         return 0;
1216 }
1217
1218
1219 #define HFSPLUS_SECTOR_SIZE        512
1220
1221 static int probe_hfsplus(struct blkid_probe *probe,
1222                          struct blkid_magic *id,
1223                          unsigned char *buf)
1224 {
1225         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
1226         struct hfsplus_bnode_descriptor *descr;
1227         struct hfsplus_bheader_record *bnode;
1228         struct hfsplus_catalog_key *key;
1229         struct hfsplus_vol_header *hfsplus;
1230         struct hfs_mdb *sbd = (struct hfs_mdb *) buf;
1231         unsigned int alloc_block_size;
1232         unsigned int alloc_first_block;
1233         unsigned int embed_first_block;
1234         unsigned int off = 0;
1235         unsigned int blocksize;
1236         unsigned int cat_block;
1237         unsigned int ext_block_start;
1238         unsigned int ext_block_count;
1239         unsigned int record_count;
1240         unsigned int leaf_node_head;
1241         unsigned int leaf_node_count;
1242         unsigned int leaf_node_size;
1243         unsigned int leaf_block;
1244         unsigned int label_len;
1245         __u64 leaf_off, uuid;
1246         char    uuid_str[17], label[512];
1247         int ext;
1248
1249         /* Check for a HFS+ volume embedded in a HFS volume */
1250         if (memcmp(sbd->signature, "BD", 2) == 0) {
1251                 if ((memcmp(sbd->embed_sig, "H+", 2) != 0) &&
1252                     (memcmp(sbd->embed_sig, "HX", 2) != 0))
1253                         /* This must be an HFS volume, so fail */
1254                         return 1;
1255
1256                 alloc_block_size = blkid_be32(sbd->al_blk_size);
1257                 alloc_first_block = blkid_be16(sbd->al_bl_st);
1258                 embed_first_block = blkid_be16(sbd->embed_startblock);
1259                 off = (alloc_first_block * 512) +
1260                         (embed_first_block * alloc_block_size);
1261                 buf = get_buffer(probe, off + (id->bim_kboff * 1024),
1262                                  sizeof(*sbd));
1263                 if (!buf)
1264                         return 1;
1265
1266                 hfsplus = (struct hfsplus_vol_header *) buf;
1267         }
1268
1269         hfsplus = (struct hfsplus_vol_header *) buf;
1270
1271         if ((memcmp(hfsplus->signature, "H+", 2) != 0) &&
1272             (memcmp(hfsplus->signature, "HX", 2) != 0))
1273                 return 1;
1274
1275         memcpy(&uuid, hfsplus->finder_info.id, 8);
1276         uuid = blkid_le64(uuid);
1277         if (uuid) {
1278                 sprintf(uuid_str, "%016llX", uuid);
1279                 blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
1280         }
1281
1282         blocksize = blkid_be32(hfsplus->blocksize);
1283         if (blocksize < HFSPLUS_SECTOR_SIZE)
1284                 return 1;
1285
1286         memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
1287         cat_block = blkid_be32(extents[0].start_block);
1288
1289         buf = get_buffer(probe, off + ((__u64) cat_block * blocksize), 0x2000);
1290         if (!buf)
1291                 return 0;
1292
1293         bnode = (struct hfsplus_bheader_record *)
1294                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
1295
1296         leaf_node_head = blkid_be32(bnode->leaf_head);
1297         leaf_node_size = blkid_be16(bnode->node_size);
1298         leaf_node_count = blkid_be32(bnode->leaf_count);
1299         if (leaf_node_count == 0)
1300                 return 0;
1301
1302         leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
1303
1304         /* get physical location */
1305         for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
1306                 ext_block_start = blkid_be32(extents[ext].start_block);
1307                 ext_block_count = blkid_be32(extents[ext].block_count);
1308                 if (ext_block_count == 0)
1309                         return 0;
1310
1311                 /* this is our extent */
1312                 if (leaf_block < ext_block_count)
1313                         break;
1314
1315                 leaf_block -= ext_block_count;
1316         }
1317         if (ext == HFSPLUS_EXTENT_COUNT)
1318                 return 0;
1319
1320         leaf_off = (__u64) (ext_block_start + leaf_block) * blocksize;
1321
1322         buf = get_buffer(probe, off + leaf_off, leaf_node_size);
1323         if (!buf)
1324                 return 0;
1325
1326         descr = (struct hfsplus_bnode_descriptor *) buf;
1327         record_count = blkid_be16(descr->num_recs);
1328         if (record_count == 0)
1329                 return 0;
1330
1331         if (descr->type != HFS_NODE_LEAF)
1332                 return 0;
1333
1334         key = (struct hfsplus_catalog_key *)
1335                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
1336
1337         if (blkid_be32(key->parent_id) != HFSPLUS_POR_CNID)
1338                 return 0;
1339
1340         label_len = blkid_be16(key->unicode_len) * 2;
1341         unicode_16be_to_utf8((unsigned char *)label, sizeof(label),
1342                              key->unicode, label_len);
1343         blkid_set_tag(probe->dev, "LABEL", label, 0);
1344         return 0;
1345 }
1346
1347 #define LVM2_LABEL_SIZE 512
1348 static unsigned int lvm2_calc_crc(const void *buf, unsigned int size)
1349 {
1350         static const unsigned int crctab[] = {
1351                 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
1352                 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
1353                 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
1354                 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
1355         };
1356         unsigned int i, crc = 0xf597a6cf;
1357         const __u8 *data = (const __u8 *) buf;
1358
1359         for (i = 0; i < size; i++) {
1360                 crc ^= *data++;
1361                 crc = (crc >> 4) ^ crctab[crc & 0xf];
1362                 crc = (crc >> 4) ^ crctab[crc & 0xf];
1363         }
1364         return crc;
1365 }
1366
1367 static int probe_lvm2(struct blkid_probe *probe,
1368                         struct blkid_magic *id,
1369                         unsigned char *buf)
1370 {
1371         int sector = (id->bim_kboff) << 1;
1372         struct lvm2_pv_label_header *label= (struct lvm2_pv_label_header *)buf;
1373         char *p, *q, uuid[40];
1374         unsigned int i, b;
1375
1376         /* buf is at 0k or 1k offset; find label inside */
1377         if (memcmp(buf, "LABELONE", 8) == 0) {
1378                 label = (struct lvm2_pv_label_header *)buf;
1379         } else if (memcmp(buf + 512, "LABELONE", 8) == 0) {
1380                 label = (struct lvm2_pv_label_header *)(buf + 512);
1381                 sector++;
1382         } else {
1383                 return 1;
1384         }
1385
1386         if (blkid_le64(label->sector_xl) != (unsigned) sector) {
1387                 DBG(DEBUG_PROBE,
1388                     printf("LVM2: label for sector %llu found at sector %d\n",
1389                            blkid_le64(label->sector_xl), sector));
1390                 return 1;
1391         }
1392
1393         if (lvm2_calc_crc(&label->offset_xl, LVM2_LABEL_SIZE -
1394                           ((char *)&label->offset_xl - (char *)label)) !=
1395                         blkid_le32(label->crc_xl)) {
1396                 DBG(DEBUG_PROBE,
1397                     printf("LVM2: label checksum incorrect at sector %d\n",
1398                            sector));
1399                 return 1;
1400         }
1401
1402         for (i=0, b=1, p=uuid, q= (char *) label->pv_uuid; i < LVM2_ID_LEN;
1403              i++, b <<= 1) {
1404                 if (b & 0x4444440)
1405                         *p++ = '-';
1406                 *p++ = *q++;
1407         }
1408
1409         blkid_set_tag(probe->dev, "UUID", uuid, LVM2_ID_LEN+6);
1410
1411         return 0;
1412 }
1413
1414 static int probe_btrfs(struct blkid_probe *probe,
1415                         struct blkid_magic *id __BLKID_ATTR((unused)),
1416                         unsigned char *buf)
1417 {
1418         struct btrfs_super_block *bs;
1419         const char *label = 0;
1420
1421         bs = (struct btrfs_super_block *)buf;
1422
1423         if (strlen(bs->label))
1424                 label = bs->label;
1425         blkid_set_tag(probe->dev, "LABEL", label, sizeof(bs->label));
1426         set_uuid(probe->dev, bs->fsid, 0);
1427         return 0;
1428 }
1429
1430 static int probe_f2fs(struct blkid_probe *probe,
1431             struct blkid_magic *id __BLKID_ATTR((unused)),
1432             unsigned char *buf)
1433 {
1434     struct f2fs_super_block *bs;
1435
1436     bs = (struct f2fs_super_block *)buf;
1437     set_uuid(probe->dev, bs->uuid, 0);
1438     return 0;
1439 }
1440
1441 static uint64_t exfat_block_to_offset(const struct exfat_super_block *sb,
1442                                       uint64_t block)
1443 {
1444     return block << sb->block_bits;
1445 }
1446
1447 static uint64_t exfat_cluster_to_block(const struct exfat_super_block *sb,
1448                                        uint32_t cluster)
1449 {
1450     return sb->cluster_block_start +
1451             ((uint64_t)(cluster - EXFAT_FIRST_DATA_CLUSTER) << sb->bpc_bits);
1452 }
1453
1454 static uint64_t exfat_cluster_to_offset(const struct exfat_super_block *sb,
1455                                         uint32_t cluster)
1456 {
1457     return exfat_block_to_offset(sb, exfat_cluster_to_block(sb, cluster));
1458 }
1459
1460 static uint32_t exfat_next_cluster(struct blkid_probe *probe,
1461                                    const struct exfat_super_block *sb,
1462                                    uint32_t cluster)
1463 {
1464     uint32_t *next;
1465     uint64_t offset;
1466
1467     offset = exfat_block_to_offset(sb, sb->fat_block_start)
1468             + (uint64_t) cluster * sizeof (cluster);
1469     next = (uint32_t *)get_buffer(probe, offset, sizeof (uint32_t));
1470
1471     return next ? *next : 0;
1472 }
1473
1474 static struct exfat_entry_label *find_exfat_entry_label(
1475     struct blkid_probe *probe, const struct exfat_super_block *sb)
1476 {
1477     uint32_t cluster = sb->rootdir_cluster;
1478     uint64_t offset = exfat_cluster_to_offset(sb, cluster);
1479     uint8_t *entry;
1480     const size_t max_iter = 10000;
1481     size_t i = 0;
1482
1483     for (; i < max_iter; ++i) {
1484         entry = (uint8_t *)get_buffer(probe, offset, EXFAT_ENTRY_SIZE);
1485         if (!entry)
1486             return NULL;
1487         if (entry[0] == EXFAT_ENTRY_EOD)
1488             return NULL;
1489         if (entry[0] == EXFAT_ENTRY_LABEL)
1490             return (struct exfat_entry_label*) entry;
1491
1492         offset += EXFAT_ENTRY_SIZE;
1493         if (offset % CLUSTER_SIZE(sb) == 0) {
1494             cluster = exfat_next_cluster(probe, sb, cluster);
1495             if (cluster < EXFAT_FIRST_DATA_CLUSTER)
1496                 return NULL;
1497             if (cluster > EXFAT_LAST_DATA_CLUSTER)
1498                 return NULL;
1499             offset = exfat_cluster_to_offset(sb, cluster);
1500         }
1501     }
1502
1503     return NULL;
1504 }
1505
1506 static int probe_exfat(struct blkid_probe *probe,
1507                        struct blkid_magic *id __BLKID_ATTR((unused)),
1508                        unsigned char *buf)
1509 {
1510     struct exfat_super_block *sb;
1511     struct exfat_entry_label *label;
1512     char uuid[40];
1513
1514     sb = (struct exfat_super_block *)buf;
1515     if (!sb || CLUSTER_SIZE(sb) == 0) {
1516         DBG(DEBUG_PROBE, printf("bad exfat superblock.\n"));
1517         return errno ? - errno : 1;
1518     }
1519
1520     label = find_exfat_entry_label(probe, sb);
1521     if (label) {
1522         unsigned char utf8_label[128];
1523         unicode_16le_to_utf8(utf8_label, sizeof(utf8_label), label->name, label->length * 2);
1524         blkid_set_tag(probe->dev, "LABEL", (char *) utf8_label, 0);
1525     } else {
1526         blkid_set_tag(probe->dev, "LABEL", "disk", 4);
1527     }
1528
1529     memset(uuid, 0, sizeof (uuid));
1530     snprintf(uuid, sizeof (uuid), "%02hhX%02hhX-%02hhX%02hhX",
1531              sb->volume_serial[3], sb->volume_serial[2],
1532              sb->volume_serial[1], sb->volume_serial[0]);
1533     blkid_set_tag(probe->dev, "UUID", uuid, strlen(uuid));
1534
1535     return 0;
1536 }
1537
1538 /*
1539  * Various filesystem magics that we can check for.  Note that kboff and
1540  * sboff are in kilobytes and bytes respectively.  All magics are in
1541  * byte strings so we don't worry about endian issues.
1542  */
1543 static struct blkid_magic type_array[] = {
1544 /*  type     kboff   sboff len  magic                   probe */
1545   { "oracleasm", 0,     32,  8, "ORCLDISK",             probe_oracleasm },
1546   { "ntfs",      0,      3,  8, "NTFS    ",             probe_ntfs },
1547   { "jbd",       1,   0x38,  2, "\123\357",             probe_jbd },
1548   { "ext4dev",   1,   0x38,  2, "\123\357",             probe_ext4dev },
1549   { "ext4",      1,   0x38,  2, "\123\357",             probe_ext4 },
1550   { "ext3",      1,   0x38,  2, "\123\357",             probe_ext3 },
1551   { "ext2",      1,   0x38,  2, "\123\357",             probe_ext2 },
1552   { "reiserfs",  8,   0x34,  8, "ReIsErFs",             probe_reiserfs },
1553   { "reiserfs", 64,   0x34,  9, "ReIsEr2Fs",            probe_reiserfs },
1554   { "reiserfs", 64,   0x34,  9, "ReIsEr3Fs",            probe_reiserfs },
1555   { "reiserfs", 64,   0x34,  8, "ReIsErFs",             probe_reiserfs },
1556   { "reiserfs",  8,     20,  8, "ReIsErFs",             probe_reiserfs },
1557   { "reiser4",  64,      0,  7, "ReIsEr4",              probe_reiserfs4 },
1558   { "gfs2",     64,      0,  4, "\x01\x16\x19\x70",     probe_gfs2 },
1559   { "gfs",      64,      0,  4, "\x01\x16\x19\x70",     probe_gfs },
1560   { "vfat",      0,   0x52,  5, "MSWIN",                probe_fat },
1561   { "vfat",      0,   0x52,  8, "FAT32   ",             probe_fat },
1562   { "vfat",      0,   0x36,  5, "MSDOS",                probe_fat },
1563   { "vfat",      0,   0x36,  8, "FAT16   ",             probe_fat },
1564   { "vfat",      0,   0x36,  8, "FAT12   ",             probe_fat },
1565   { "vfat",      0,      0,  1, "\353",                 probe_fat_nomagic },
1566   { "vfat",      0,      0,  1, "\351",                 probe_fat_nomagic },
1567   { "vfat",      0,  0x1fe,  2, "\125\252",             probe_fat_nomagic },
1568   { "minix",     1,   0x10,  2, "\177\023",             0 },
1569   { "minix",     1,   0x10,  2, "\217\023",             0 },
1570   { "minix",     1,   0x10,  2, "\150\044",             0 },
1571   { "minix",     1,   0x10,  2, "\170\044",             0 },
1572   { "vxfs",      1,      0,  4, "\365\374\001\245",     0 },
1573   { "xfs",       0,      0,  4, "XFSB",                 probe_xfs },
1574   { "romfs",     0,      0,  8, "-rom1fs-",             probe_romfs },
1575   { "bfs",       0,      0,  4, "\316\372\173\033",     0 },
1576   { "cramfs",    0,      0,  4, "E=\315\050",           probe_cramfs },
1577   { "qnx4",      0,      4,  6, "QNX4FS",               0 },
1578   { "udf",      32,      1,  5, "BEA01",                probe_udf },
1579   { "udf",      32,      1,  5, "BOOT2",                probe_udf },
1580   { "udf",      32,      1,  5, "CD001",                probe_udf },
1581   { "udf",      32,      1,  5, "CDW02",                probe_udf },
1582   { "udf",      32,      1,  5, "NSR02",                probe_udf },
1583   { "udf",      32,      1,  5, "NSR03",                probe_udf },
1584   { "udf",      32,      1,  5, "TEA01",                probe_udf },
1585   { "iso9660",  32,      1,  5, "CD001",                probe_iso9660 },
1586   { "iso9660",  32,      9,  5, "CDROM",                probe_iso9660 },
1587   { "jfs",      32,      0,  4, "JFS1",                 probe_jfs },
1588   /* ZFS has 128 root blocks (#4 is the first used), check only 6 of them */
1589   { "zfs",     128,      0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
1590   { "zfs",     128,      0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
1591   { "zfs",     132,      0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
1592   { "zfs",     132,      0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
1593   { "zfs",     136,      0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
1594   { "zfs",     136,      0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
1595   { "zfs",     384,      0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
1596   { "zfs",     384,      0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
1597   { "zfs",     388,      0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
1598   { "zfs",     388,      0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
1599   { "zfs",     392,      0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
1600   { "zfs",     392,      0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
1601   { "hfsplus",   1,      0,  2, "BD",                   probe_hfsplus },
1602   { "hfsplus",   1,      0,  2, "H+",                   probe_hfsplus },
1603   { "hfsplus",   1,      0,  2, "HX",                   probe_hfsplus },
1604   { "hfs",       1,      0,  2, "BD",                   probe_hfs },
1605   { "ufs",       8,  0x55c,  4, "T\031\001\000",        0 },
1606   { "hpfs",      8,      0,  4, "I\350\225\371",        0 },
1607   { "sysv",      0,  0x3f8,  4, "\020~\030\375",        0 },
1608   { "swap",      0,  0xff6, 10, "SWAP-SPACE",           probe_swap0 },
1609   { "swap",      0,  0xff6, 10, "SWAPSPACE2",           probe_swap1 },
1610   { "swsuspend", 0,  0xff6,  9, "S1SUSPEND",            probe_swap1 },
1611   { "swsuspend", 0,  0xff6,  9, "S2SUSPEND",            probe_swap1 },
1612   { "swsuspend", 0,  0xff6,  9, "ULSUSPEND",            probe_swap1 },
1613   { "swap",      0, 0x1ff6, 10, "SWAP-SPACE",           probe_swap0 },
1614   { "swap",      0, 0x1ff6, 10, "SWAPSPACE2",           probe_swap1 },
1615   { "swsuspend", 0, 0x1ff6,  9, "S1SUSPEND",            probe_swap1 },
1616   { "swsuspend", 0, 0x1ff6,  9, "S2SUSPEND",            probe_swap1 },
1617   { "swsuspend", 0, 0x1ff6,  9, "ULSUSPEND",            probe_swap1 },
1618   { "swap",      0, 0x3ff6, 10, "SWAP-SPACE",           probe_swap0 },
1619   { "swap",      0, 0x3ff6, 10, "SWAPSPACE2",           probe_swap1 },
1620   { "swsuspend", 0, 0x3ff6,  9, "S1SUSPEND",            probe_swap1 },
1621   { "swsuspend", 0, 0x3ff6,  9, "S2SUSPEND",            probe_swap1 },
1622   { "swsuspend", 0, 0x3ff6,  9, "ULSUSPEND",            probe_swap1 },
1623   { "swap",      0, 0x7ff6, 10, "SWAP-SPACE",           probe_swap0 },
1624   { "swap",      0, 0x7ff6, 10, "SWAPSPACE2",           probe_swap1 },
1625   { "swsuspend", 0, 0x7ff6,  9, "S1SUSPEND",            probe_swap1 },
1626   { "swsuspend", 0, 0x7ff6,  9, "S2SUSPEND",            probe_swap1 },
1627   { "swsuspend", 0, 0x7ff6,  9, "ULSUSPEND",            probe_swap1 },
1628   { "swap",      0, 0xfff6, 10, "SWAP-SPACE",           probe_swap0 },
1629   { "swap",      0, 0xfff6, 10, "SWAPSPACE2",           probe_swap1 },
1630   { "swsuspend", 0, 0xfff6,  9, "S1SUSPEND",            probe_swap1 },
1631   { "swsuspend", 0, 0xfff6,  9, "S2SUSPEND",            probe_swap1 },
1632   { "swsuspend", 0, 0xfff6,  9, "ULSUSPEND",            probe_swap1 },
1633   { "ocfs",      0,      8,  9, "OracleCFS",            probe_ocfs },
1634   { "ocfs2",     1,      0,  6, "OCFSV2",               probe_ocfs2 },
1635   { "ocfs2",     2,      0,  6, "OCFSV2",               probe_ocfs2 },
1636   { "ocfs2",     4,      0,  6, "OCFSV2",               probe_ocfs2 },
1637   { "ocfs2",     8,      0,  6, "OCFSV2",               probe_ocfs2 },
1638   { "crypt_LUKS", 0,     0,  6, "LUKS\xba\xbe",         probe_luks },
1639   { "squashfs",  0,      0,  4, "sqsh",                 0 },
1640   { "squashfs",  0,      0,  4, "hsqs",                 0 },
1641   { "lvm2pv",    0,  0x218,  8, "LVM2 001",             probe_lvm2 },
1642   { "lvm2pv",    0,  0x018,  8, "LVM2 001",             probe_lvm2 },
1643   { "lvm2pv",    1,  0x018,  8, "LVM2 001",             probe_lvm2 },
1644   { "lvm2pv",    1,  0x218,  8, "LVM2 001",             probe_lvm2 },
1645   { "btrfs",     64,  0x40,  8, "_BHRfS_M",             probe_btrfs },
1646   { "f2fs",      1,      0,  4, "\x10\x20\xf5\xf2",     probe_f2fs },
1647   { "exfat",     0,      3,  8, "EXFAT   ",             probe_exfat },
1648   {   NULL,      0,      0,  0, NULL,                   NULL }
1649 };
1650
1651 /*
1652  * Verify that the data in dev is consistent with what is on the actual
1653  * block device (using the devname field only).  Normally this will be
1654  * called when finding items in the cache, but for long running processes
1655  * is also desirable to revalidate an item before use.
1656  *
1657  * If we are unable to revalidate the data, we return the old data and
1658  * do not set the BLKID_BID_FL_VERIFIED flag on it.
1659  */
1660 blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
1661 {
1662         struct blkid_magic *id;
1663         struct blkid_probe probe;
1664         blkid_tag_iterate iter;
1665         unsigned char *buf;
1666         const char *type, *value;
1667         struct stat st;
1668         time_t now;
1669         double diff;
1670         int idx;
1671
1672         if (!dev)
1673                 return NULL;
1674
1675         now = time(0);
1676         diff = difftime(now, dev->bid_time);
1677
1678         if (stat(dev->bid_name, &st) < 0) {
1679                 DBG(DEBUG_PROBE,
1680                     printf("blkid_verify: error %s (%d) while "
1681                            "trying to stat %s\n", strerror(errno), errno,
1682                            dev->bid_name));
1683         open_err:
1684                 if ((errno == EPERM) || (errno == EACCES) || (errno == ENOENT)) {
1685                         /* We don't have read permission, just return cache data. */
1686                         DBG(DEBUG_PROBE, printf("returning unverified data for %s\n",
1687                                                 dev->bid_name));
1688                         return dev;
1689                 }
1690                 blkid_free_dev(dev);
1691                 return NULL;
1692         }
1693
1694         if ((now >= dev->bid_time) &&
1695             (st.st_mtime <= dev->bid_time) &&
1696             ((diff < BLKID_PROBE_MIN) ||
1697              (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
1698               diff < BLKID_PROBE_INTERVAL)))
1699                 return dev;
1700
1701         DBG(DEBUG_PROBE,
1702             printf("need to revalidate %s (cache time %lu, stat time %lu,\n\t"
1703                    "time since last check %lu)\n",
1704                    dev->bid_name, (unsigned long)dev->bid_time,
1705                    (unsigned long)st.st_mtime, (unsigned long)diff));
1706
1707         if ((probe.fd = open(dev->bid_name, O_RDONLY)) < 0) {
1708                 DBG(DEBUG_PROBE, printf("blkid_verify: error %s (%d) while "
1709                                         "opening %s\n", strerror(errno), errno,
1710                                         dev->bid_name));
1711                 goto open_err;
1712         }
1713
1714         probe.cache = cache;
1715         probe.dev = dev;
1716         probe.sbbuf = 0;
1717         probe.buf = 0;
1718         probe.buf_max = 0;
1719
1720         /*
1721          * Iterate over the type array.  If we already know the type,
1722          * then try that first.  If it doesn't work, then blow away
1723          * the type information, and try again.
1724          *
1725          */
1726 try_again:
1727         type = 0;
1728         if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
1729                 uuid_t  uuid;
1730
1731                 if (check_mdraid(probe.fd, uuid) == 0) {
1732                         set_uuid(dev, uuid, 0);
1733                         type = "mdraid";
1734                         goto found_type;
1735                 }
1736         }
1737         for (id = type_array; id->bim_type; id++) {
1738                 if (dev->bid_type &&
1739                     strcmp(id->bim_type, dev->bid_type))
1740                         continue;
1741
1742                 idx = id->bim_kboff + (id->bim_sboff >> 10);
1743                 buf = get_buffer(&probe, (__u64) idx << 10, 1024);
1744                 if (!buf)
1745                         continue;
1746
1747                 if (memcmp(id->bim_magic, buf + (id->bim_sboff & 0x3ff),
1748                            id->bim_len))
1749                         continue;
1750
1751                 if ((id->bim_probe == NULL) ||
1752                     (id->bim_probe(&probe, id, buf) == 0)) {
1753                         type = id->bim_type;
1754                         goto found_type;
1755                 }
1756         }
1757
1758         if (!id->bim_type && dev->bid_type) {
1759                 /*
1760                  * Zap the device filesystem information and try again
1761                  */
1762                 DBG(DEBUG_PROBE,
1763                     printf("previous fs type %s not valid, "
1764                            "trying full probe\n", dev->bid_type));
1765                 iter = blkid_tag_iterate_begin(dev);
1766                 while (blkid_tag_next(iter, &type, &value) == 0)
1767                         blkid_set_tag(dev, type, 0, 0);
1768                 blkid_tag_iterate_end(iter);
1769                 goto try_again;
1770         }
1771
1772         if (!dev->bid_type) {
1773                 blkid_free_dev(dev);
1774                 dev = 0;
1775                 goto found_type;
1776         }
1777
1778 found_type:
1779         if (dev && type) {
1780                 dev->bid_devno = st.st_rdev;
1781                 dev->bid_time = time(0);
1782                 dev->bid_flags |= BLKID_BID_FL_VERIFIED;
1783                 cache->bic_flags |= BLKID_BIC_FL_CHANGED;
1784
1785                 blkid_set_tag(dev, "TYPE", type, 0);
1786
1787                 DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
1788                            dev->bid_name, (long long)st.st_rdev, type));
1789         }
1790
1791         free(probe.sbbuf);
1792         free(probe.buf);
1793         if (probe.fd >= 0)
1794                 close(probe.fd);
1795
1796         return dev;
1797 }
1798
1799 int blkid_known_fstype(const char *fstype)
1800 {
1801         struct blkid_magic *id;
1802
1803         for (id = type_array; id->bim_type; id++) {
1804                 if (strcmp(fstype, id->bim_type) == 0)
1805                         return 1;
1806         }
1807         return 0;
1808 }
1809
1810 #ifdef TEST_PROGRAM
1811 int main(int argc, char **argv)
1812 {
1813         blkid_dev dev;
1814         blkid_cache cache;
1815         int ret;
1816
1817         if (argc != 2) {
1818                 fprintf(stderr, "Usage: %s device\n"
1819                         "Probe a single device to determine type\n", argv[0]);
1820                 exit(1);
1821         }
1822         if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
1823                 fprintf(stderr, "%s: error creating cache (%d)\n",
1824                         argv[0], ret);
1825                 exit(1);
1826         }
1827         dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
1828         if (!dev) {
1829                 printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
1830                 return (1);
1831         }
1832         printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");
1833         if (dev->bid_label)
1834                 printf("LABEL='%s'\n", dev->bid_label);
1835         if (dev->bid_uuid)
1836                 printf("UUID='%s'\n", dev->bid_uuid);
1837
1838         blkid_free_dev(dev);
1839         return (0);
1840 }
1841 #endif