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 #ifdef __linux__
  30 #include <sys/utsname.h>
  31 #endif
  32 #ifdef HAVE_ERRNO_H
  33 #include <errno.h>
  34 #endif
  35 #include "blkidP.h"
  36 #include "uuid/uuid.h"
  37 #include "probe.h"
  38
  39 static int figure_label_len(const unsigned char *label, int len)
  40 {
  41         const unsigned char *end = label + len - 1;
  42
  43         while ((*end == ' ' || *end == 0) && end >= label)
  44                 --end;
  45         if (end >= label) {
  46                 label = label;
  47                 return end - label + 1;
  48         }
  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
 111         /* Check for magic number */
 112         if (memcmp("\251+N\374", buf, 4) && memcmp("\374N+\251", buf, 4))
 113                 return -BLKID_ERR_PARAM;
 114
 115         if (!ret_uuid)
 116                 return 0;
 117         *ret_uuid = 0;
 118
 119         /* The MD UUID is not contiguous in the superblock, make it so */
 120         md = (struct mdp_superblock_s *)buf;
 121         if (md->set_uuid0 || md->set_uuid1 || md->set_uuid2 || md->set_uuid3) {
 122                 memcpy(ret_uuid, &md->set_uuid0, 4);
 123                 memcpy(ret_uuid + 4, &md->set_uuid1, 12);
 124         }
 125         return 0;
 126 }
 127
 128 static void set_uuid(blkid_dev dev, uuid_t uuid, const char *tag)
 129 {
 130         char    str[37];
 131
 132         if (!uuid_is_null(uuid)) {
 133                 uuid_unparse(uuid, str);
 134                 blkid_set_tag(dev, tag ? tag : "UUID", str, sizeof(str));
 135         }
 136 }
 137
 138 static void get_ext2_info(blkid_dev dev, struct blkid_magic *id,
 139                           unsigned char *buf)
 140 {
 141         struct ext2_super_block *es = (struct ext2_super_block *) buf;
 142         const char *label = 0;
 143
 144         DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",
 145                    blkid_le32(es->s_feature_compat),
 146                    blkid_le32(es->s_feature_incompat),
 147                    blkid_le32(es->s_feature_ro_compat)));
 148
 149         if (strlen(es->s_volume_name))
 150                 label = es->s_volume_name;
 151         blkid_set_tag(dev, "LABEL", label, sizeof(es->s_volume_name));
 152
 153         set_uuid(dev, es->s_uuid, 0);
 154
 155         if ((es->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
 156             !uuid_is_null(es->s_journal_uuid))
 157                 set_uuid(dev, es->s_journal_uuid, "EXT_JOURNAL");
 158
 159         if (strcmp(id->bim_type, "ext2") &&
 160             ((blkid_le32(es->s_feature_incompat) &
 161               EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0))
 162                 blkid_set_tag(dev, "SEC_TYPE", "ext2", sizeof("ext2"));
 163 }
 164
 165 /*
 166  * Check to see if a filesystem is in /proc/filesystems.
 167  * Returns 1 if found, 0 if not
 168  */
 169 static int fs_proc_check(const char *fs_name)
 170 {
 171         FILE    *f;
 172         char    buf[80], *cp, *t;
 173
 174         f = fopen("/proc/filesystems", "r");
 175         if (!f)
 176                 return (0);
 177         while (!feof(f)) {
 178                 if (!fgets(buf, sizeof(buf), f))
 179                         break;
 180                 cp = buf;
 181                 if (!isspace(*cp)) {
 182                         while (*cp && !isspace(*cp))
 183                                 cp++;
 184                 }
 185                 while (*cp && isspace(*cp))
 186                         cp++;
 187                 if ((t = strchr(cp, '\n')) != NULL)
 188                         *t = 0;
 189                 if ((t = strchr(cp, '\t')) != NULL)
 190                         *t = 0;
 191                 if ((t = strchr(cp, ' ')) != NULL)
 192                         *t = 0;
 193                 if (!strcmp(fs_name, cp)) {
 194                         fclose(f);
 195                         return (1);
 196                 }
 197         }
 198         fclose(f);
 199         return (0);
 200 }
 201
 202 /*
 203  * Check to see if a filesystem is available as a module
 204  * Returns 1 if found, 0 if not
 205  */
 206 static int check_for_modules(const char *fs_name)
 207 {
 208 #ifdef __linux__
 209         struct utsname  uts;
 210         FILE            *f;
 211         char            buf[1024], *cp, *t;
 212         int             i;
 213
 214         if (uname(&uts))
 215                 return (0);
 216         snprintf(buf, sizeof(buf), "/lib/modules/%s/modules.dep", uts.release);
 217
 218         f = fopen(buf, "r");
 219         if (!f)
 220                 return (0);
 221         while (!feof(f)) {
 222                 if (!fgets(buf, sizeof(buf), f))
 223                         break;
 224                 if ((cp = strchr(buf, ':')) != NULL)
 225                         *cp = 0;
 226                 else
 227                         continue;
 228                 if ((cp = strrchr(buf, '/')) != NULL)
 229                         cp++;
 230                 i = strlen(cp);
 231                 if (i > 3) {
 232                         t = cp + i - 3;
 233                         if (!strcmp(t, ".ko"))
 234                                 *t = 0;
 235                 }
 236                 if (!strcmp(cp, fs_name)) {
 237                         fclose(f);
 238                         return (1);
 239                 }
 240         }
 241         fclose(f);
 242 #endif
 243         return (0);
 244 }
 245
 246 static int system_supports_ext4(void)
 247 {
 248         static time_t   last_check = 0;
 249         static int      ret = -1;
 250         time_t          now = time(0);
 251
 252         if (ret != -1 || (now - last_check) < 5)
 253                 return ret;
 254         last_check = now;
 255         ret = (fs_proc_check("ext4") || check_for_modules("ext4"));
 256         return ret;
 257 }
 258
 259 static int system_supports_ext4dev(void)
 260 {
 261         static time_t   last_check = 0;
 262         static int      ret = -1;
 263         time_t          now = time(0);
 264
 265         if (ret != -1 || (now - last_check) < 5)
 266                 return ret;
 267         last_check = now;
 268         ret = (fs_proc_check("ext4dev") || check_for_modules("ext4dev"));
 269         return ret;
 270 }
 271
 272 static int probe_ext4dev(struct blkid_probe *probe,
 273                          struct blkid_magic *id,
 274                          unsigned char *buf)
 275 {
 276         struct ext2_super_block *es;
 277         es = (struct ext2_super_block *)buf;
 278
 279         /* Distinguish from jbd */
 280         if (blkid_le32(es->s_feature_incompat) &
 281             EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
 282                 return -BLKID_ERR_PARAM;
 283
 284         /* ext4dev requires a journal */
 285         if (!(blkid_le32(es->s_feature_compat) &
 286               EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 287                 return -BLKID_ERR_PARAM;
 288
 289         /*
 290          * If the filesystem is marked as OK for use by in-development
 291          * filesystem code, but ext4dev is not supported, and ext4 is,
 292          * then don't call ourselves ext4dev, since we should be
 293          * detected as ext4 in that case.
 294          *
 295          * If the filesystem is marked as in use by production
 296          * filesystem, then it can only be used by ext4 and NOT by
 297          * ext4dev, so always disclaim we are ext4dev in that case.
 298          */
 299         if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) {
 300                 if (!system_supports_ext4dev() && system_supports_ext4())
 301                         return -BLKID_ERR_PARAM;
 302         } else
 303                 return -BLKID_ERR_PARAM;
 304
 305         get_ext2_info(probe->dev, id, buf);
 306         return 0;
 307 }
 308
 309 static int probe_ext4(struct blkid_probe *probe, struct blkid_magic *id,
 310                       unsigned char *buf)
 311 {
 312         struct ext2_super_block *es;
 313         es = (struct ext2_super_block *)buf;
 314
 315         /* Distinguish from jbd */
 316         if (blkid_le32(es->s_feature_incompat) &
 317             EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
 318                 return -BLKID_ERR_PARAM;
 319
 320         /* ext4 requires journal */
 321         if (!(blkid_le32(es->s_feature_compat) &
 322               EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 323                 return -BLKID_ERR_PARAM;
 324
 325         /* Ext4 has at least one feature which ext3 doesn't understand */
 326         if (!(blkid_le32(es->s_feature_ro_compat) &
 327               EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) &&
 328             !(blkid_le32(es->s_feature_incompat) &
 329               EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
 330                 return -BLKID_ERR_PARAM;
 331
 332         /*
 333          * If the filesystem is a OK for use by in-development
 334          * filesystem code, and ext4dev is supported or ext4 is not
 335          * supported, then don't call ourselves ext4, so we can redo
 336          * the detection and mark the filesystem as ext4dev.
 337          *
 338          * If the filesystem is marked as in use by production
 339          * filesystem, then it can only be used by ext4 and NOT by
 340          * ext4dev.
 341          */
 342         if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) {
 343                 if (system_supports_ext4dev() || !system_supports_ext4())
 344                         return -BLKID_ERR_PARAM;
 345         }
 346         get_ext2_info(probe->dev, id, buf);
 347         return 0;
 348 }
 349
 350 static int probe_ext3(struct blkid_probe *probe, struct blkid_magic *id,
 351                       unsigned char *buf)
 352 {
 353         struct ext2_super_block *es;
 354         es = (struct ext2_super_block *)buf;
 355
 356         /* ext3 requires journal */
 357         if (!(blkid_le32(es->s_feature_compat) &
 358               EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 359                 return -BLKID_ERR_PARAM;
 360
 361         /* Any features which ext3 doesn't understand */
 362         if ((blkid_le32(es->s_feature_ro_compat) &
 363              EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) ||
 364             (blkid_le32(es->s_feature_incompat) &
 365              EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
 366                 return -BLKID_ERR_PARAM;
 367
 368         get_ext2_info(probe->dev, id, buf);
 369         return 0;
 370 }
 371
 372 static int probe_ext2(struct blkid_probe *probe, struct blkid_magic *id,
 373                       unsigned char *buf)
 374 {
 375         struct ext2_super_block *es;
 376
 377         es = (struct ext2_super_block *)buf;
 378
 379         /* Distinguish between ext3 and ext2 */
 380         if ((blkid_le32(es->s_feature_compat) &
 381               EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 382                 return -BLKID_ERR_PARAM;
 383
 384         /* Any features which ext2 doesn't understand */
 385         if ((blkid_le32(es->s_feature_ro_compat) &
 386              EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) ||
 387             (blkid_le32(es->s_feature_incompat) &
 388              EXT2_FEATURE_INCOMPAT_UNSUPPORTED))
 389                 return -BLKID_ERR_PARAM;
 390
 391         get_ext2_info(probe->dev, id, buf);
 392         return 0;
 393 }
 394
 395 static int probe_jbd(struct blkid_probe *probe, struct blkid_magic *id,
 396                      unsigned char *buf)
 397 {
 398         struct ext2_super_block *es = (struct ext2_super_block *) buf;
 399
 400         if (!(blkid_le32(es->s_feature_incompat) &
 401               EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
 402                 return -BLKID_ERR_PARAM;
 403
 404         get_ext2_info(probe->dev, id, buf);
 405
 406         return 0;
 407 }
 408
 409 #define FAT_ATTR_VOLUME_ID              0x08
 410 #define FAT_ATTR_DIR                    0x10
 411 #define FAT_ATTR_LONG_NAME              0x0f
 412 #define FAT_ATTR_MASK                   0x3f
 413 #define FAT_ENTRY_FREE                  0xe5
 414
 415 static const char *no_name = "NO NAME    ";
 416
 417 static unsigned char *search_fat_label(struct vfat_dir_entry *dir, int count)
 418 {
 419         int i;
 420
 421         for (i = 0; i < count; i++) {
 422                 if (dir[i].name[0] == 0x00)
 423                         break;
 424
 425                 if ((dir[i].name[0] == FAT_ENTRY_FREE) ||
 426                     (dir[i].cluster_high != 0 || dir[i].cluster_low != 0) ||
 427                     ((dir[i].attr & FAT_ATTR_MASK) == FAT_ATTR_LONG_NAME))
 428                         continue;
 429
 430                 if ((dir[i].attr & (FAT_ATTR_VOLUME_ID | FAT_ATTR_DIR)) ==
 431                     FAT_ATTR_VOLUME_ID) {
 432                         return dir[i].name;
 433                 }
 434         }
 435         return 0;
 436 }
 437
 438 /* FAT label extraction from the root directory taken from Kay
 439  * Sievers's volume_id library */
 440 static int probe_fat(struct blkid_probe *probe,
 441                       struct blkid_magic *id __BLKID_ATTR((unused)),
 442                       unsigned char *buf)
 443 {
 444         struct vfat_super_block *vs = (struct vfat_super_block *) buf;
 445         struct msdos_super_block *ms = (struct msdos_super_block *) buf;
 446         struct vfat_dir_entry *dir;
 447         char serno[10];
 448         const unsigned char *label = 0, *vol_label = 0, *tmp;
 449         unsigned char   *vol_serno;
 450         int label_len = 0, maxloop = 100;
 451         __u16 sector_size, dir_entries, reserved;
 452         __u32 sect_count, fat_size, dir_size, cluster_count, fat_length;
 453         __u32 buf_size, start_data_sect, next, root_start, root_dir_entries;
 454
 455         /* sector size check */
 456         tmp = (unsigned char *)&ms->ms_sector_size;
 457         sector_size = tmp[0] + (tmp[1] << 8);
 458         if (sector_size != 0x200 && sector_size != 0x400 &&
 459             sector_size != 0x800 && sector_size != 0x1000)
 460                 return 1;
 461
 462         tmp = (unsigned char *)&ms->ms_dir_entries;
 463         dir_entries = tmp[0] + (tmp[1] << 8);
 464         reserved =  blkid_le16(ms->ms_reserved);
 465         tmp = (unsigned char *)&ms->ms_sectors;
 466         sect_count = tmp[0] + (tmp[1] << 8);
 467         if (sect_count == 0)
 468                 sect_count = blkid_le32(ms->ms_total_sect);
 469
 470         fat_length = blkid_le16(ms->ms_fat_length);
 471         if (fat_length == 0)
 472                 fat_length = blkid_le32(vs->vs_fat32_length);
 473
 474         fat_size = fat_length * ms->ms_fats;
 475         dir_size = ((dir_entries * sizeof(struct vfat_dir_entry)) +
 476                         (sector_size-1)) / sector_size;
 477
 478         cluster_count = sect_count - (reserved + fat_size + dir_size);
 479         if (ms->ms_cluster_size == 0)
 480                 return 1;
 481         cluster_count /= ms->ms_cluster_size;
 482
 483         if (cluster_count > FAT32_MAX)
 484                 return 1;
 485
 486         if (ms->ms_fat_length) {
 487                 /* the label may be an attribute in the root directory */
 488                 root_start = (reserved + fat_size) * sector_size;
 489                 root_dir_entries = vs->vs_dir_entries[0] +
 490                         (vs->vs_dir_entries[1] << 8);
 491
 492                 buf_size = root_dir_entries * sizeof(struct vfat_dir_entry);
 493                 dir = (struct vfat_dir_entry *) get_buffer(probe, root_start,
 494                                                            buf_size);
 495                 if (dir)
 496                         vol_label = search_fat_label(dir, root_dir_entries);
 497
 498                 if (!vol_label || !memcmp(vol_label, no_name, 11))
 499                         vol_label = ms->ms_label;
 500                 vol_serno = ms->ms_serno;
 501
 502                 blkid_set_tag(probe->dev, "SEC_TYPE", "msdos",
 503                               sizeof("msdos"));
 504         } else {
 505                 /* Search the FAT32 root dir for the label attribute */
 506                 buf_size = vs->vs_cluster_size * sector_size;
 507                 start_data_sect = reserved + fat_size;
 508
 509                 next = blkid_le32(vs->vs_root_cluster);
 510                 while (next && --maxloop) {
 511                         __u32 next_sect_off;
 512                         __u64 next_off, fat_entry_off;
 513                         int count;
 514
 515                         next_sect_off = (next - 2) * vs->vs_cluster_size;
 516                         next_off = (start_data_sect + next_sect_off) *
 517                                 sector_size;
 518
 519                         dir = (struct vfat_dir_entry *)
 520                                 get_buffer(probe, next_off, buf_size);
 521                         if (dir == NULL)
 522                                 break;
 523
 524                         count = buf_size / sizeof(struct vfat_dir_entry);
 525
 526                         vol_label = search_fat_label(dir, count);
 527                         if (vol_label)
 528                                 break;
 529
 530                         /* get FAT entry */
 531                         fat_entry_off = (reserved * sector_size) +
 532                                 (next * sizeof(__u32));
 533                         buf = get_buffer(probe, fat_entry_off, buf_size);
 534                         if (buf == NULL)
 535                                 break;
 536
 537                         /* set next cluster */
 538                         next = blkid_le32(*((__u32 *) buf) & 0x0fffffff);
 539                 }
 540
 541                 if (!vol_label || !memcmp(vol_label, no_name, 11))
 542                         vol_label = vs->vs_label;
 543                 vol_serno = vs->vs_serno;
 544         }
 545
 546         if (vol_label && memcmp(vol_label, no_name, 11)) {
 547                 if ((label_len = figure_label_len(vol_label, 11)))
 548                         label = vol_label;
 549         }
 550
 551         /* We can't just print them as %04X, because they are unaligned */
 552         sprintf(serno, "%02X%02X-%02X%02X", vol_serno[3], vol_serno[2],
 553                 vol_serno[1], vol_serno[0]);
 554
 555         blkid_set_tag(probe->dev, "LABEL", (const char *) label, label_len);
 556         blkid_set_tag(probe->dev, "UUID", serno, sizeof(serno)-1);
 557
 558         return 0;
 559 }
 560
 561 /*
 562  * The FAT filesystem could be without a magic string in superblock
 563  * (e.g. old floppies).  This heuristic for FAT detection is inspired
 564  * by http://vrfy.org/projects/volume_id/ and Linux kernel.
 565  * [7-Jul-2005, Karel Zak <kzak@redhat.com>]
 566  */
 567 static int probe_fat_nomagic(struct blkid_probe *probe,
 568                              struct blkid_magic *id __BLKID_ATTR((unused)),
 569                              unsigned char *buf)
 570 {
 571         struct msdos_super_block *ms;
 572
 573         ms = (struct msdos_super_block *)buf;
 574
 575         /* heads check */
 576         if (ms->ms_heads == 0)
 577                 return 1;
 578
 579         /* cluster size check*/
 580         if (ms->ms_cluster_size == 0 ||
 581             (ms->ms_cluster_size & (ms->ms_cluster_size-1)))
 582                 return 1;
 583
 584         /* media check */
 585         if (ms->ms_media < 0xf8 && ms->ms_media != 0xf0)
 586                 return 1;
 587
 588         /* fat counts(Linux kernel expects at least 1 FAT table) */
 589         if (!ms->ms_fats)
 590                 return 1;
 591
 592         /*
 593          * OS/2 and apparently DFSee will place a FAT12/16-like
 594          * pseudo-superblock in the first 512 bytes of non-FAT
 595          * filesystems --- at least JFS and HPFS, and possibly others.
 596          * So we explicitly check for those filesystems at the
 597          * FAT12/16 filesystem magic field identifier, and if they are
 598          * present, we rule this out as a FAT filesystem, despite the
 599          * FAT-like pseudo-header.
 600          */
 601         if ((memcmp(ms->ms_magic, "JFS     ", 8) == 0) ||
 602             (memcmp(ms->ms_magic, "HPFS    ", 8) == 0))
 603                 return 1;
 604
 605         return probe_fat(probe, id, buf);
 606 }
 607
 608 static int probe_ntfs(struct blkid_probe *probe,
 609                       struct blkid_magic *id __BLKID_ATTR((unused)),
 610                       unsigned char *buf)
 611 {
 612         struct ntfs_super_block *ns;
 613         struct master_file_table_record *mft;
 614         struct file_attribute *attr;
 615         char            uuid_str[17], label_str[129], *cp;
 616         int             bytes_per_sector, sectors_per_cluster;
 617         int             mft_record_size, attr_off, attr_len;
 618         unsigned int    i, attr_type, val_len;
 619         int             val_off;
 620         __u64           nr_clusters;
 621         blkid_loff_t off;
 622         unsigned char *buf_mft, *val;
 623
 624         ns = (struct ntfs_super_block *) buf;
 625
 626         bytes_per_sector = ns->bios_parameter_block[0] +
 627                 (ns->bios_parameter_block[1]  << 8);
 628         sectors_per_cluster = ns->bios_parameter_block[2];
 629
 630         if ((bytes_per_sector < 512) || (sectors_per_cluster == 0))
 631                 return 1;
 632
 633         if (ns->cluster_per_mft_record < 0)
 634                 mft_record_size = 1 << (0-ns->cluster_per_mft_record);
 635         else
 636                 mft_record_size = ns->cluster_per_mft_record *
 637                         sectors_per_cluster * bytes_per_sector;
 638         nr_clusters = blkid_le64(ns->number_of_sectors) / sectors_per_cluster;
 639
 640         if ((blkid_le64(ns->mft_cluster_location) > nr_clusters) ||
 641             (blkid_le64(ns->mft_mirror_cluster_location) > nr_clusters))
 642                 return 1;
 643
 644         off = blkid_le64(ns->mft_mirror_cluster_location) *
 645                 bytes_per_sector * sectors_per_cluster;
 646
 647         buf_mft = get_buffer(probe, off, mft_record_size);
 648         if (!buf_mft)
 649                 return 1;
 650
 651         if (memcmp(buf_mft, "FILE", 4))
 652                 return 1;
 653
 654         off = blkid_le64(ns->mft_cluster_location) * bytes_per_sector *
 655                 sectors_per_cluster;
 656
 657         buf_mft = get_buffer(probe, off, mft_record_size);
 658         if (!buf_mft)
 659                 return 1;
 660
 661         if (memcmp(buf_mft, "FILE", 4))
 662                 return 1;
 663
 664         off += MFT_RECORD_VOLUME * mft_record_size;
 665
 666         buf_mft = get_buffer(probe, off, mft_record_size);
 667         if (!buf_mft)
 668                 return 1;
 669
 670         if (memcmp(buf_mft, "FILE", 4))
 671                 return 1;
 672
 673         mft = (struct master_file_table_record *) buf_mft;
 674
 675         attr_off = blkid_le16(mft->attrs_offset);
 676         label_str[0] = 0;
 677
 678         while (1) {
 679                 attr = (struct file_attribute *) (buf_mft + attr_off);
 680                 attr_len = blkid_le16(attr->len);
 681                 attr_type = blkid_le32(attr->type);
 682                 val_off = blkid_le16(attr->value_offset);
 683                 val_len = blkid_le32(attr->value_len);
 684
 685                 attr_off += attr_len;
 686
 687                 if ((attr_off > mft_record_size) ||
 688                     (attr_len == 0))
 689                         break;
 690
 691                 if (attr_type == MFT_RECORD_ATTR_END)
 692                         break;
 693
 694                 if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
 695                         if (val_len > sizeof(label_str))
 696                                 val_len = sizeof(label_str)-1;
 697
 698                         for (i=0, cp=label_str; i < val_len; i+=2,cp++) {
 699                                 val = ((__u8 *) attr) + val_off + i;
 700                                 *cp = val[0];
 701                                 if (val[1])
 702                                         *cp = '?';
 703                         }
 704                         *cp = 0;
 705                 }
 706         }
 707
 708         sprintf(uuid_str, "%016llX", blkid_le64(ns->volume_serial));
 709         blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
 710         if (label_str[0])
 711                 blkid_set_tag(probe->dev, "LABEL", label_str, 0);
 712         return 0;
 713 }
 714
 715
 716 static int probe_xfs(struct blkid_probe *probe,
 717                      struct blkid_magic *id __BLKID_ATTR((unused)),
 718                      unsigned char *buf)
 719 {
 720         struct xfs_super_block *xs;
 721         const char *label = 0;
 722
 723         xs = (struct xfs_super_block *)buf;
 724
 725         if (strlen(xs->xs_fname))
 726                 label = xs->xs_fname;
 727         blkid_set_tag(probe->dev, "LABEL", label, sizeof(xs->xs_fname));
 728         set_uuid(probe->dev, xs->xs_uuid, 0);
 729         return 0;
 730 }
 731
 732 static int probe_reiserfs(struct blkid_probe *probe,
 733                           struct blkid_magic *id, unsigned char *buf)
 734 {
 735         struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
 736         unsigned int blocksize;
 737         const char *label = 0;
 738
 739         blocksize = blkid_le16(rs->rs_blocksize);
 740
 741         /* The blocksize must be at least 1k */
 742         if ((blocksize >> 10) == 0)
 743                 return -BLKID_ERR_PARAM;
 744
 745         /* If the superblock is inside the journal, we have the wrong one */
 746         if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
 747                 return -BLKID_ERR_BIG;
 748
 749         /* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
 750         if (id->bim_magic[6] == '2' || id->bim_magic[6] == '3') {
 751                 if (strlen(rs->rs_label))
 752                         label = rs->rs_label;
 753                 set_uuid(probe->dev, rs->rs_uuid, 0);
 754         }
 755         blkid_set_tag(probe->dev, "LABEL", label, sizeof(rs->rs_label));
 756
 757         return 0;
 758 }
 759
 760 static int probe_reiserfs4(struct blkid_probe *probe,
 761                            struct blkid_magic *id __BLKID_ATTR((unused)),
 762                            unsigned char *buf)
 763 {
 764         struct reiser4_super_block *rs4 = (struct reiser4_super_block *) buf;
 765         const unsigned char *label = 0;
 766
 767         if (strlen((char *) rs4->rs4_label))
 768                 label = rs4->rs4_label;
 769         set_uuid(probe->dev, rs4->rs4_uuid, 0);
 770         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 771                       sizeof(rs4->rs4_label));
 772
 773         return 0;
 774 }
 775
 776 static int probe_jfs(struct blkid_probe *probe,
 777                      struct blkid_magic *id __BLKID_ATTR((unused)),
 778                      unsigned char *buf)
 779 {
 780         struct jfs_super_block *js;
 781         const char *label = 0;
 782
 783         js = (struct jfs_super_block *)buf;
 784
 785         if (blkid_le32(js->js_bsize) != (1 << blkid_le16(js->js_l2bsize)))
 786                 return 1;
 787
 788         if (blkid_le32(js->js_pbsize) != (1 << blkid_le16(js->js_l2pbsize)))
 789                 return 1;
 790
 791         if ((blkid_le16(js->js_l2bsize) - blkid_le16(js->js_l2pbsize)) !=
 792             blkid_le16(js->js_l2bfactor))
 793                 return 1;
 794
 795         if (strlen((char *) js->js_label))
 796                 label = (char *) js->js_label;
 797         blkid_set_tag(probe->dev, "LABEL", label, sizeof(js->js_label));
 798         set_uuid(probe->dev, js->js_uuid, 0);
 799         return 0;
 800 }
 801
 802 static int probe_zfs(struct blkid_probe *probe, struct blkid_magic *id,
 803                      unsigned char *buf)
 804 {
 805 #if 0
 806         char *vdev_label;
 807         const char *pool_name = 0;
 808
 809         /* read nvpair data for pool name, pool GUID (complex) */
 810         blkid_set_tag(probe->dev, "LABEL", pool_name, sizeof(pool_name));
 811         set_uuid(probe->dev, pool_guid, 0);
 812 #endif
 813         return 0;
 814 }
 815
 816 static int probe_luks(struct blkid_probe *probe,
 817                        struct blkid_magic *id __BLKID_ATTR((unused)),
 818                        unsigned char *buf)
 819 {
 820         char uuid[40];
 821
 822         /* 168 is the offset to the 40 character uuid:
 823          * http://luks.endorphin.org/LUKS-on-disk-format.pdf */
 824         strncpy(uuid, (char *) buf+168, 40);
 825         blkid_set_tag(probe->dev, "UUID", uuid, sizeof(uuid));
 826         return 0;
 827 }
 828
 829 static int probe_romfs(struct blkid_probe *probe,
 830                        struct blkid_magic *id __BLKID_ATTR((unused)),
 831                        unsigned char *buf)
 832 {
 833         struct romfs_super_block *ros;
 834         const char *label = 0;
 835
 836         ros = (struct romfs_super_block *)buf;
 837
 838         if (strlen((char *) ros->ros_volume))
 839                 label = (char *) ros->ros_volume;
 840         blkid_set_tag(probe->dev, "LABEL", label, 0);
 841         return 0;
 842 }
 843
 844 static int probe_cramfs(struct blkid_probe *probe,
 845                         struct blkid_magic *id __BLKID_ATTR((unused)),
 846                         unsigned char *buf)
 847 {
 848         struct cramfs_super_block *csb;
 849         const char *label = 0;
 850
 851         csb = (struct cramfs_super_block *)buf;
 852
 853         if (strlen((char *) csb->name))
 854                 label = (char *) csb->name;
 855         blkid_set_tag(probe->dev, "LABEL", label, 0);
 856         return 0;
 857 }
 858
 859 static int probe_swap0(struct blkid_probe *probe,
 860                        struct blkid_magic *id __BLKID_ATTR((unused)),
 861                        unsigned char *buf __BLKID_ATTR((unused)))
 862 {
 863         blkid_set_tag(probe->dev, "UUID", 0, 0);
 864         blkid_set_tag(probe->dev, "LABEL", 0, 0);
 865         return 0;
 866 }
 867
 868 static int probe_swap1(struct blkid_probe *probe,
 869                        struct blkid_magic *id,
 870                        unsigned char *buf __BLKID_ATTR((unused)))
 871 {
 872         struct swap_id_block *sws;
 873
 874         probe_swap0(probe, id, buf);
 875         /*
 876          * Version 1 swap headers are always located at offset of 1024
 877          * bytes, although the swap signature itself is located at the
 878          * end of the page (which may vary depending on hardware
 879          * pagesize).
 880          */
 881         sws = (struct swap_id_block *) get_buffer(probe, 1024, 1024);
 882         if (!sws)
 883                 return 1;
 884
 885         /* check for wrong version or zeroed pagecount, for sanity */
 886         if (!memcmp(id->bim_magic, "SWAPSPACE2", id->bim_len) &&
 887                         (sws->sws_version != 1 || sws->sws_lastpage == 0))
 888                 return 1;
 889
 890         /* arbitrary sanity check.. is there any garbage down there? */
 891         if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0)  {
 892                 if (sws->sws_volume[0])
 893                         blkid_set_tag(probe->dev, "LABEL", sws->sws_volume,
 894                                       sizeof(sws->sws_volume));
 895                 if (sws->sws_uuid[0])
 896                         set_uuid(probe->dev, sws->sws_uuid, 0);
 897         }
 898         return 0;
 899 }
 900
 901 static int probe_iso9660(struct blkid_probe *probe,
 902                          struct blkid_magic *id __BLKID_ATTR((unused)),
 903                          unsigned char *buf)
 904 {
 905         struct iso_volume_descriptor *iso;
 906         const unsigned char *label;
 907
 908         iso = (struct iso_volume_descriptor *) buf;
 909         label = iso->volume_id;
 910
 911         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 912                       figure_label_len(label, 32));
 913         return 0;
 914 }
 915
 916
 917 static const char
 918 *udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
 919                  "NSR03", "TEA01", 0 };
 920
 921 static int probe_udf(struct blkid_probe *probe,
 922                      struct blkid_magic *id __BLKID_ATTR((unused)),
 923                      unsigned char *buf __BLKID_ATTR((unused)))
 924 {
 925         int j, bs;
 926         struct iso_volume_descriptor *isosb;
 927         const char ** m;
 928
 929         /* determine the block size by scanning in 2K increments
 930            (block sizes larger than 2K will be null padded) */
 931         for (bs = 1; bs < 16; bs++) {
 932                 isosb = (struct iso_volume_descriptor *)
 933                         get_buffer(probe, bs*2048+32768, sizeof(isosb));
 934                 if (!isosb)
 935                         return 1;
 936                 if (isosb->vd_id[0])
 937                         break;
 938         }
 939
 940         /* Scan up to another 64 blocks looking for additional VSD's */
 941         for (j = 1; j < 64; j++) {
 942                 if (j > 1) {
 943                         isosb = (struct iso_volume_descriptor *)
 944                                 get_buffer(probe, j*bs*2048+32768,
 945                                            sizeof(isosb));
 946                         if (!isosb)
 947                                 return 1;
 948                 }
 949                 /* If we find NSR0x then call it udf:
 950                    NSR01 for UDF 1.00
 951                    NSR02 for UDF 1.50
 952                    NSR03 for UDF 2.00 */
 953                 if (!memcmp(isosb->vd_id, "NSR0", 4))
 954                         return probe_iso9660(probe, id, buf);
 955                 for (m = udf_magic; *m; m++)
 956                         if (!memcmp(*m, isosb->vd_id, 5))
 957                                 break;
 958                 if (*m == 0)
 959                         return 1;
 960         }
 961         return 1;
 962 }
 963
 964 static int probe_ocfs(struct blkid_probe *probe,
 965                       struct blkid_magic *id __BLKID_ATTR((unused)),
 966                       unsigned char *buf)
 967 {
 968         struct ocfs_volume_header ovh;
 969         struct ocfs_volume_label ovl;
 970         __u32 major;
 971
 972         memcpy(&ovh, buf, sizeof(ovh));
 973         memcpy(&ovl, buf+512, sizeof(ovl));
 974
 975         major = ocfsmajor(ovh);
 976         if (major == 1)
 977                 blkid_set_tag(probe->dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
 978         else if (major >= 9)
 979                 blkid_set_tag(probe->dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
 980
 981         blkid_set_tag(probe->dev, "LABEL", ovl.label, ocfslabellen(ovl));
 982         blkid_set_tag(probe->dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
 983         set_uuid(probe->dev, ovl.vol_id, 0);
 984         return 0;
 985 }
 986
 987 static int probe_ocfs2(struct blkid_probe *probe,
 988                        struct blkid_magic *id __BLKID_ATTR((unused)),
 989                        unsigned char *buf)
 990 {
 991         struct ocfs2_super_block *osb;
 992
 993         osb = (struct ocfs2_super_block *)buf;
 994
 995         blkid_set_tag(probe->dev, "LABEL", osb->s_label, sizeof(osb->s_label));
 996         set_uuid(probe->dev, osb->s_uuid, 0);
 997         return 0;
 998 }
 999
1000 static int probe_oracleasm(struct blkid_probe *probe,
1001                            struct blkid_magic *id __BLKID_ATTR((unused)),
1002                            unsigned char *buf)
1003 {
1004         struct oracle_asm_disk_label *dl;
1005
1006         dl = (struct oracle_asm_disk_label *)buf;
1007
1008         blkid_set_tag(probe->dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
1009         return 0;
1010 }
1011
1012 static int probe_gfs(struct blkid_probe *probe,
1013                      struct blkid_magic *id __BLKID_ATTR((unused)),
1014                      unsigned char *buf)
1015 {
1016         struct gfs2_sb *sbd;
1017         const char *label = 0;
1018
1019         sbd = (struct gfs2_sb *)buf;
1020
1021         if (blkid_be32(sbd->sb_fs_format) == GFS_FORMAT_FS &&
1022             blkid_be32(sbd->sb_multihost_format) == GFS_FORMAT_MULTI)
1023         {
1024                 blkid_set_tag(probe->dev, "UUID", 0, 0);
1025
1026                 if (strlen(sbd->sb_locktable))
1027                         label = sbd->sb_locktable;
1028                 blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
1029                 return 0;
1030         }
1031         return 1;
1032 }
1033
1034 static int probe_gfs2(struct blkid_probe *probe,
1035                      struct blkid_magic *id __BLKID_ATTR((unused)),
1036                      unsigned char *buf)
1037 {
1038         struct gfs2_sb *sbd;
1039         const char *label = 0;
1040
1041         sbd = (struct gfs2_sb *)buf;
1042
1043         if (blkid_be32(sbd->sb_fs_format) == GFS2_FORMAT_FS &&
1044             blkid_be32(sbd->sb_multihost_format) == GFS2_FORMAT_MULTI)
1045         {
1046                 blkid_set_tag(probe->dev, "UUID", 0, 0);
1047
1048                 if (strlen(sbd->sb_locktable))
1049                         label = sbd->sb_locktable;
1050                 blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
1051                 return 0;
1052         }
1053         return 1;
1054 }
1055
1056 static void unicode_16be_to_utf8(unsigned char *str, int out_len,
1057                                  const unsigned char *buf, int in_len)
1058 {
1059         int i, j;
1060         unsigned int c;
1061
1062         for (i = j = 0; i + 2 <= in_len; i += 2) {
1063                 c = (buf[i] << 8) | buf[i+1];
1064                 if (c == 0) {
1065                         str[j] = '\0';
1066                         break;
1067                 } else if (c < 0x80) {
1068                         if (j+1 >= out_len)
1069                                 break;
1070                         str[j++] = (unsigned char) c;
1071                 } else if (c < 0x800) {
1072                         if (j+2 >= out_len)
1073                                 break;
1074                         str[j++] = (unsigned char) (0xc0 | (c >> 6));
1075                         str[j++] = (unsigned char) (0x80 | (c & 0x3f));
1076                 } else {
1077                         if (j+3 >= out_len)
1078                                 break;
1079                         str[j++] = (unsigned char) (0xe0 | (c >> 12));
1080                         str[j++] = (unsigned char) (0x80 | ((c >> 6) & 0x3f));
1081                         str[j++] = (unsigned char) (0x80 | (c & 0x3f));
1082                 }
1083         }
1084         str[j] = '\0';
1085 }
1086
1087 static int probe_hfs(struct blkid_probe *probe __BLKID_ATTR((unused)),
1088                          struct blkid_magic *id __BLKID_ATTR((unused)),
1089                          unsigned char *buf)
1090 {
1091         struct hfs_mdb *hfs = (struct hfs_mdb *) buf;
1092         char    uuid_str[17];
1093         __u64   uuid;
1094
1095         if ((memcmp(hfs->embed_sig, "H+", 2) == 0) ||
1096             (memcmp(hfs->embed_sig, "HX", 2) == 0))
1097                 return 1;       /* Not hfs, but an embedded HFS+ */
1098
1099         uuid = blkid_le64(*((unsigned long long *) hfs->finder_info.id));
1100         if (uuid) {
1101                 sprintf(uuid_str, "%016llX", uuid);
1102                 blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
1103         }
1104         blkid_set_tag(probe->dev, "LABEL", hfs->label, hfs->label_len);
1105         return 0;
1106 }
1107
1108
1109 static int probe_hfsplus(struct blkid_probe *probe,
1110                          struct blkid_magic *id,
1111                          unsigned char *buf)
1112 {
1113         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
1114         struct hfsplus_bnode_descriptor *descr;
1115         struct hfsplus_bheader_record *bnode;
1116         struct hfsplus_catalog_key *key;
1117         struct hfsplus_vol_header *hfsplus;
1118         struct hfs_mdb *sbd = (struct hfs_mdb *) buf;
1119         unsigned int alloc_block_size;
1120         unsigned int alloc_first_block;
1121         unsigned int embed_first_block;
1122         unsigned int off = 0;
1123         unsigned int blocksize;
1124         unsigned int cat_block;
1125         unsigned int ext_block_start;
1126         unsigned int ext_block_count;
1127         unsigned int record_count;
1128         unsigned int leaf_node_head;
1129         unsigned int leaf_node_count;
1130         unsigned int leaf_node_size;
1131         unsigned int leaf_block;
1132         unsigned int label_len;
1133         int ext;
1134         __u64 leaf_off, uuid;
1135         char    uuid_str[17], label[512];
1136
1137         /* Check for a HFS+ volume embedded in a HFS volume */
1138         if (memcmp(sbd->signature, "BD", 2) == 0) {
1139                 if ((memcmp(sbd->embed_sig, "H+", 2) != 0) &&
1140                     (memcmp(sbd->embed_sig, "HX", 2) != 0))
1141                         /* This must be an HFS volume, so fail */
1142                         return 1;
1143
1144                 alloc_block_size = blkid_be32(sbd->al_blk_size);
1145                 alloc_first_block = blkid_be16(sbd->al_bl_st);
1146                 embed_first_block = blkid_be16(sbd->embed_startblock);
1147                 off = (alloc_first_block * 512) +
1148                         (embed_first_block * alloc_block_size);
1149                 buf = get_buffer(probe, off + (id->bim_kboff * 1024),
1150                                  sizeof(sbd));
1151                 if (!buf)
1152                         return 1;
1153
1154                 hfsplus = (struct hfsplus_vol_header *) buf;
1155         }
1156
1157         hfsplus = (struct hfsplus_vol_header *) buf;
1158
1159         if ((memcmp(hfsplus->signature, "H+", 2) != 0) &&
1160             (memcmp(hfsplus->signature, "HX", 2) != 0))
1161                 return 1;
1162
1163         uuid = blkid_le64(*((unsigned long long *) hfsplus->finder_info.id));
1164         if (uuid) {
1165                 sprintf(uuid_str, "%016llX", uuid);
1166                 blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
1167         }
1168
1169         blocksize = blkid_be32(hfsplus->blocksize);
1170         memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
1171         cat_block = blkid_be32(extents[0].start_block);
1172
1173         buf = get_buffer(probe, off + (cat_block * blocksize), 0x2000);
1174         if (!buf)
1175                 return 0;
1176
1177         bnode = (struct hfsplus_bheader_record *)
1178                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
1179
1180         leaf_node_head = blkid_be32(bnode->leaf_head);
1181         leaf_node_size = blkid_be16(bnode->node_size);
1182         leaf_node_count = blkid_be32(bnode->leaf_count);
1183         if (leaf_node_count == 0)
1184                 return 0;
1185
1186         leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
1187
1188         /* get physical location */
1189         for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
1190                 ext_block_start = blkid_be32(extents[ext].start_block);
1191                 ext_block_count = blkid_be32(extents[ext].block_count);
1192                 if (ext_block_count == 0)
1193                         return 0;
1194
1195                 /* this is our extent */
1196                 if (leaf_block < ext_block_count)
1197                         break;
1198
1199                 leaf_block -= ext_block_count;
1200         }
1201         if (ext == HFSPLUS_EXTENT_COUNT)
1202                 return 0;
1203
1204         leaf_off = (ext_block_start + leaf_block) * blocksize;
1205
1206         buf = get_buffer(probe, off + leaf_off, leaf_node_size);
1207         if (!buf)
1208                 return 0;
1209
1210         descr = (struct hfsplus_bnode_descriptor *) buf;
1211         record_count = blkid_be16(descr->num_recs);
1212         if (record_count == 0)
1213                 return 0;
1214
1215         if (descr->type != HFS_NODE_LEAF)
1216                 return 0;
1217
1218         key = (struct hfsplus_catalog_key *)
1219                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
1220
1221         if (blkid_be32(key->parent_id) != HFSPLUS_POR_CNID)
1222                 return 0;
1223
1224         label_len = blkid_be16(key->unicode_len) * 2;
1225         unicode_16be_to_utf8(label, sizeof(label), key->unicode, label_len);
1226         blkid_set_tag(probe->dev, "LABEL", label, 0);
1227         return 0;
1228 }
1229
1230 #define LVM2_LABEL_SIZE 512
1231 static unsigned int lvm2_calc_crc(const void *buf, unsigned int size)
1232 {
1233         static const unsigned int crctab[] = {
1234                 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
1235                 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
1236                 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
1237                 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
1238         };
1239         unsigned int i, crc = 0xf597a6cf;
1240         const __u8 *data = (const __u8 *) buf;
1241
1242         for (i = 0; i < size; i++) {
1243                 crc ^= *data++;
1244                 crc = (crc >> 4) ^ crctab[crc & 0xf];
1245                 crc = (crc >> 4) ^ crctab[crc & 0xf];
1246         }
1247         return crc;
1248 }
1249
1250 static int probe_lvm2(struct blkid_probe *probe,
1251                         struct blkid_magic *id,
1252                         unsigned char *buf)
1253 {
1254         int sector = (id->bim_kboff) << 1;
1255         struct lvm2_pv_label_header *label= (struct lvm2_pv_label_header *)buf;
1256         char *p, *q, uuid[40];
1257         unsigned int i, b;
1258
1259         /* buf is at 0k or 1k offset; find label inside */
1260         if (memcmp(buf, "LABELONE", 8) == 0) {
1261                 label = (struct lvm2_pv_label_header *)buf;
1262         } else if (memcmp(buf + 512, "LABELONE", 8) == 0) {
1263                 label = (struct lvm2_pv_label_header *)(buf + 512);
1264                 sector++;
1265         } else {
1266                 return 1;
1267         }
1268
1269         if (blkid_le64(label->sector_xl) != (unsigned) sector) {
1270                 DBG(DEBUG_PROBE,
1271                     printf("LVM2: label for sector %llu found at sector %d\n",
1272                            blkid_le64(label->sector_xl), sector));
1273                 return 1;
1274         }
1275
1276         if (lvm2_calc_crc(&label->offset_xl, LVM2_LABEL_SIZE -
1277                           ((char *)&label->offset_xl - (char *)label)) !=
1278                         blkid_le32(label->crc_xl)) {
1279                 DBG(DEBUG_PROBE,
1280                     printf("LVM2: label checksum incorrect at sector %d\n",
1281                            sector));
1282                 return 1;
1283         }
1284
1285         for (i=0, b=1, p=uuid, q= (char *) label->pv_uuid; i <= 32;
1286              i++, b <<= 1) {
1287                 if (b & 0x4444440)
1288                         *p++ = '-';
1289                 *p++ = *q++;
1290         }
1291
1292         blkid_set_tag(probe->dev, "UUID", uuid, LVM2_ID_LEN+6);
1293
1294         return 0;
1295 }
1296
1297 static int probe_btrfs(struct blkid_probe *probe,
1298                         struct blkid_magic *id,
1299                         unsigned char *buf)
1300 {
1301         struct btrfs_super_block *bs;
1302         const char *label = 0;
1303
1304         bs = (struct btrfs_super_block *)buf;
1305
1306         if (strlen(bs->label))
1307                 label = bs->label;
1308         blkid_set_tag(probe->dev, "LABEL", label, sizeof(bs->label));
1309         set_uuid(probe->dev, bs->fsid, 0);
1310         return 0;
1311 }
1312 /*
1313  * Various filesystem magics that we can check for.  Note that kboff and
1314  * sboff are in kilobytes and bytes respectively.  All magics are in
1315  * byte strings so we don't worry about endian issues.
1316  */
1317 static struct blkid_magic type_array[] = {
1318 /*  type     kboff   sboff len  magic                   probe */
1319   { "oracleasm", 0,     32,  8, "ORCLDISK",             probe_oracleasm },
1320   { "ntfs",      0,      3,  8, "NTFS    ",             probe_ntfs },
1321   { "jbd",       1,   0x38,  2, "\123\357",             probe_jbd },
1322   { "ext4dev",   1,   0x38,  2, "\123\357",             probe_ext4dev },
1323   { "ext4",      1,   0x38,  2, "\123\357",             probe_ext4 },
1324   { "ext3",      1,   0x38,  2, "\123\357",             probe_ext3 },
1325   { "ext2",      1,   0x38,  2, "\123\357",             probe_ext2 },
1326   { "reiserfs",  8,   0x34,  8, "ReIsErFs",             probe_reiserfs },
1327   { "reiserfs", 64,   0x34,  9, "ReIsEr2Fs",            probe_reiserfs },
1328   { "reiserfs", 64,   0x34,  9, "ReIsEr3Fs",            probe_reiserfs },
1329   { "reiserfs", 64,   0x34,  8, "ReIsErFs",             probe_reiserfs },
1330   { "reiserfs",  8,     20,  8, "ReIsErFs",             probe_reiserfs },
1331   { "reiser4",  64,      0,  7, "ReIsEr4",              probe_reiserfs4 },
1332   { "gfs2",     64,      0,  4, "\x01\x16\x19\x70",     probe_gfs2 },
1333   { "gfs",      64,      0,  4, "\x01\x16\x19\x70",     probe_gfs },
1334   { "vfat",      0,   0x52,  5, "MSWIN",                probe_fat },
1335   { "vfat",      0,   0x52,  8, "FAT32   ",             probe_fat },
1336   { "vfat",      0,   0x36,  5, "MSDOS",                probe_fat },
1337   { "vfat",      0,   0x36,  8, "FAT16   ",             probe_fat },
1338   { "vfat",      0,   0x36,  8, "FAT12   ",             probe_fat },
1339   { "vfat",      0,      0,  1, "\353",                 probe_fat_nomagic },
1340   { "vfat",      0,      0,  1, "\351",                 probe_fat_nomagic },
1341   { "vfat",      0,  0x1fe,  2, "\125\252",             probe_fat_nomagic },
1342   { "minix",     1,   0x10,  2, "\177\023",             0 },
1343   { "minix",     1,   0x10,  2, "\217\023",             0 },
1344   { "minix",     1,   0x10,  2, "\150\044",             0 },
1345   { "minix",     1,   0x10,  2, "\170\044",             0 },
1346   { "vxfs",      1,      0,  4, "\365\374\001\245",     0 },
1347   { "xfs",       0,      0,  4, "XFSB",                 probe_xfs },
1348   { "romfs",     0,      0,  8, "-rom1fs-",             probe_romfs },
1349   { "bfs",       0,      0,  4, "\316\372\173\033",     0 },
1350   { "cramfs",    0,      0,  4, "E=\315\050",           probe_cramfs },
1351   { "qnx4",      0,      4,  6, "QNX4FS",               0 },
1352   { "udf",      32,      1,  5, "BEA01",                probe_udf },
1353   { "udf",      32,      1,  5, "BOOT2",                probe_udf },
1354   { "udf",      32,      1,  5, "CD001",                probe_udf },
1355   { "udf",      32,      1,  5, "CDW02",                probe_udf },
1356   { "udf",      32,      1,  5, "NSR02",                probe_udf },
1357   { "udf",      32,      1,  5, "NSR03",                probe_udf },
1358   { "udf",      32,      1,  5, "TEA01",                probe_udf },
1359   { "iso9660",  32,      1,  5, "CD001",                probe_iso9660 },
1360   { "iso9660",  32,      9,  5, "CDROM",                probe_iso9660 },
1361   { "jfs",      32,      0,  4, "JFS1",                 probe_jfs },
1362   { "zfs",       8,      0,  8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", probe_zfs },
1363   { "zfs",       8,      0,  8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", probe_zfs },
1364   { "zfs",     264,      0,  8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", probe_zfs },
1365   { "zfs",     264,      0,  8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", probe_zfs },
1366   { "hfsplus",   1,      0,  2, "BD",                   probe_hfsplus },
1367   { "hfsplus",   1,      0,  2, "H+",                   probe_hfsplus },
1368   { "hfsplus",   1,      0,  2, "HX",                   probe_hfsplus },
1369   { "hfs",       1,      0,  2, "BD",                   probe_hfs },
1370   { "ufs",       8,  0x55c,  4, "T\031\001\000",        0 },
1371   { "hpfs",      8,      0,  4, "I\350\225\371",        0 },
1372   { "sysv",      0,  0x3f8,  4, "\020~\030\375",        0 },
1373   { "swap",      0,  0xff6, 10, "SWAP-SPACE",           probe_swap0 },
1374   { "swap",      0,  0xff6, 10, "SWAPSPACE2",           probe_swap1 },
1375   { "swsuspend", 0,  0xff6,  9, "S1SUSPEND",            probe_swap1 },
1376   { "swsuspend", 0,  0xff6,  9, "S2SUSPEND",            probe_swap1 },
1377   { "swap",      0, 0x1ff6, 10, "SWAP-SPACE",           probe_swap0 },
1378   { "swap",      0, 0x1ff6, 10, "SWAPSPACE2",           probe_swap1 },
1379   { "swsuspend", 0, 0x1ff6,  9, "S1SUSPEND",            probe_swap1 },
1380   { "swsuspend", 0, 0x1ff6,  9, "S2SUSPEND",            probe_swap1 },
1381   { "swap",      0, 0x3ff6, 10, "SWAP-SPACE",           probe_swap0 },
1382   { "swap",      0, 0x3ff6, 10, "SWAPSPACE2",           probe_swap1 },
1383   { "swsuspend", 0, 0x3ff6,  9, "S1SUSPEND",            probe_swap1 },
1384   { "swsuspend", 0, 0x3ff6,  9, "S2SUSPEND",            probe_swap1 },
1385   { "swap",      0, 0x7ff6, 10, "SWAP-SPACE",           probe_swap0 },
1386   { "swap",      0, 0x7ff6, 10, "SWAPSPACE2",           probe_swap1 },
1387   { "swsuspend", 0, 0x7ff6,  9, "S1SUSPEND",            probe_swap1 },
1388   { "swsuspend", 0, 0x7ff6,  9, "S2SUSPEND",            probe_swap1 },
1389   { "swap",      0, 0xfff6, 10, "SWAP-SPACE",           probe_swap0 },
1390   { "swap",      0, 0xfff6, 10, "SWAPSPACE2",           probe_swap1 },
1391   { "swsuspend", 0, 0xfff6,  9, "S1SUSPEND",            probe_swap1 },
1392   { "swsuspend", 0, 0xfff6,  9, "S2SUSPEND",            probe_swap1 },
1393   { "ocfs",      0,      8,  9, "OracleCFS",            probe_ocfs },
1394   { "ocfs2",     1,      0,  6, "OCFSV2",               probe_ocfs2 },
1395   { "ocfs2",     2,      0,  6, "OCFSV2",               probe_ocfs2 },
1396   { "ocfs2",     4,      0,  6, "OCFSV2",               probe_ocfs2 },
1397   { "ocfs2",     8,      0,  6, "OCFSV2",               probe_ocfs2 },
1398   { "crypt_LUKS", 0,     0,  6, "LUKS\xba\xbe",         probe_luks },
1399   { "squashfs",  0,      0,  4, "sqsh",                 0 },
1400   { "squashfs",  0,      0,  4, "hsqs",                 0 },
1401   { "lvm2pv",    0,  0x218,  8, "LVM2 001",             probe_lvm2 },
1402   { "lvm2pv",    0,  0x018,  8, "LVM2 001",             probe_lvm2 },
1403   { "lvm2pv",    1,  0x018,  8, "LVM2 001",             probe_lvm2 },
1404   { "lvm2pv",    1,  0x218,  8, "LVM2 001",             probe_lvm2 },
1405   { "btrfs",     64,  0x40,  8, "_BHRfS_M",             probe_btrfs },
1406   {   NULL,      0,      0,  0, NULL,                   NULL }
1407 };
1408
1409 /*
1410  * Verify that the data in dev is consistent with what is on the actual
1411  * block device (using the devname field only).  Normally this will be
1412  * called when finding items in the cache, but for long running processes
1413  * is also desirable to revalidate an item before use.
1414  *
1415  * If we are unable to revalidate the data, we return the old data and
1416  * do not set the BLKID_BID_FL_VERIFIED flag on it.
1417  */
1418 blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
1419 {
1420         struct blkid_magic *id;
1421         struct blkid_probe probe;
1422         blkid_tag_iterate iter;
1423         unsigned char *buf;
1424         const char *type, *value;
1425         struct stat st;
1426         time_t diff, now;
1427         int idx;
1428
1429         if (!dev)
1430                 return NULL;
1431
1432         now = time(0);
1433         diff = now - dev->bid_time;
1434
1435         if (stat(dev->bid_name, &st) < 0) {
1436                 DBG(DEBUG_PROBE,
1437                     printf("blkid_verify: error %s (%d) while "
1438                            "trying to stat %s\n", strerror(errno), errno,
1439                            dev->bid_name));
1440         open_err:
1441                 if ((errno == EPERM) || (errno == EACCES) || (errno == ENOENT)) {
1442                         /* We don't have read permission, just return cache data. */
1443                         DBG(DEBUG_PROBE, printf("returning unverified data for %s\n",
1444                                                 dev->bid_name));
1445                         return dev;
1446                 }
1447                 blkid_free_dev(dev);
1448                 return NULL;
1449         }
1450
1451         if ((now >= dev->bid_time) &&
1452             (st.st_mtime <= dev->bid_time) &&
1453             ((diff < BLKID_PROBE_MIN) ||
1454              (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
1455               diff < BLKID_PROBE_INTERVAL)))
1456                 return dev;
1457
1458         DBG(DEBUG_PROBE,
1459             printf("need to revalidate %s (cache time %lu, stat time %lu,\n\t"
1460                    "time since last check %lu)\n",
1461                    dev->bid_name, (unsigned long)dev->bid_time,
1462                    (unsigned long)st.st_mtime, (unsigned long)diff));
1463
1464         if ((probe.fd = open(dev->bid_name, O_RDONLY)) < 0) {
1465                 DBG(DEBUG_PROBE, printf("blkid_verify: error %s (%d) while "
1466                                         "opening %s\n", strerror(errno), errno,
1467                                         dev->bid_name));
1468                 goto open_err;
1469         }
1470
1471         probe.cache = cache;
1472         probe.dev = dev;
1473         probe.sbbuf = 0;
1474         probe.buf = 0;
1475         probe.buf_max = 0;
1476
1477         /*
1478          * Iterate over the type array.  If we already know the type,
1479          * then try that first.  If it doesn't work, then blow away
1480          * the type information, and try again.
1481          *
1482          */
1483 try_again:
1484         type = 0;
1485         if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
1486                 uuid_t  uuid;
1487
1488                 if (check_mdraid(probe.fd, uuid) == 0) {
1489                         set_uuid(dev, uuid, 0);
1490                         type = "mdraid";
1491                         goto found_type;
1492                 }
1493         }
1494         for (id = type_array; id->bim_type; id++) {
1495                 if (dev->bid_type &&
1496                     strcmp(id->bim_type, dev->bid_type))
1497                         continue;
1498
1499                 idx = id->bim_kboff + (id->bim_sboff >> 10);
1500                 buf = get_buffer(&probe, idx << 10, 1024);
1501                 if (!buf)
1502                         continue;
1503
1504                 if (memcmp(id->bim_magic, buf + (id->bim_sboff & 0x3ff),
1505                            id->bim_len))
1506                         continue;
1507
1508                 if ((id->bim_probe == NULL) ||
1509                     (id->bim_probe(&probe, id, buf) == 0)) {
1510                         type = id->bim_type;
1511                         goto found_type;
1512                 }
1513         }
1514
1515         if (!id->bim_type && dev->bid_type) {
1516                 /*
1517                  * Zap the device filesystem information and try again
1518                  */
1519                 DBG(DEBUG_PROBE,
1520                     printf("previous fs type %s not valid, "
1521                            "trying full probe\n", dev->bid_type));
1522                 iter = blkid_tag_iterate_begin(dev);
1523                 while (blkid_tag_next(iter, &type, &value) == 0)
1524                         blkid_set_tag(dev, type, 0, 0);
1525                 blkid_tag_iterate_end(iter);
1526                 goto try_again;
1527         }
1528
1529         if (!dev->bid_type) {
1530                 blkid_free_dev(dev);
1531                 dev = 0;
1532                 goto found_type;
1533         }
1534
1535 found_type:
1536         if (dev && type) {
1537                 dev->bid_devno = st.st_rdev;
1538                 dev->bid_time = time(0);
1539                 dev->bid_flags |= BLKID_BID_FL_VERIFIED;
1540                 cache->bic_flags |= BLKID_BIC_FL_CHANGED;
1541
1542                 blkid_set_tag(dev, "TYPE", type, 0);
1543
1544                 DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
1545                            dev->bid_name, (long long)st.st_rdev, type));
1546         }
1547
1548         if (probe.sbbuf)
1549                 free(probe.sbbuf);
1550         if (probe.buf)
1551                 free(probe.buf);
1552         if (probe.fd >= 0)
1553                 close(probe.fd);
1554
1555         return dev;
1556 }
1557
1558 int blkid_known_fstype(const char *fstype)
1559 {
1560         struct blkid_magic *id;
1561
1562         for (id = type_array; id->bim_type; id++) {
1563                 if (strcmp(fstype, id->bim_type) == 0)
1564                         return 1;
1565         }
1566         return 0;
1567 }
1568
1569 #ifdef TEST_PROGRAM
1570 int main(int argc, char **argv)
1571 {
1572         blkid_dev dev;
1573         blkid_cache cache;
1574         int ret;
1575
1576         if (argc != 2) {
1577                 fprintf(stderr, "Usage: %s device\n"
1578                         "Probe a single device to determine type\n", argv[0]);
1579                 exit(1);
1580         }
1581         if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
1582                 fprintf(stderr, "%s: error creating cache (%d)\n",
1583                         argv[0], ret);
1584                 exit(1);
1585         }
1586         dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
1587         if (!dev) {
1588                 printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
1589                 return (1);
1590         }
1591         printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");
1592         if (dev->bid_label)
1593                 printf("LABEL='%s'\n", dev->bid_label);
1594         if (dev->bid_uuid)
1595                 printf("UUID='%s'\n", dev->bid_uuid);
1596
1597         blkid_free_dev(dev);
1598         return (0);
1599 }
1600 #endif