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 <unistd.h>
  21 #include <fcntl.h>
  22 #include <ctype.h>
  23 #include <sys/types.h>
  24 #ifdef HAVE_SYS_STAT_H
  25 #include <sys/stat.h>
  26 #endif
  27 #ifdef HAVE_SYS_MKDEV_H
  28 #include <sys/mkdev.h>
  29 #endif
  30 #ifdef __linux__
  31 #include <sys/utsname.h>
  32 #endif
  33 #ifdef HAVE_ERRNO_H
  34 #include <errno.h>
  35 #endif
  36 #include "blkidP.h"
  37 #include "uuid/uuid.h"
  38 #include "probe.h"
  39
  40 static int figure_label_len(const unsigned char *label, int len)
  41 {
  42         const unsigned char *end = label + len - 1;
  43
  44         while ((*end == ' ' || *end == 0) && end >= label)
  45                 --end;
  46         if (end >= label)
  47                 return end - label + 1;
  48         return 0;
  49 }
  50
  51 static unsigned char *get_buffer(struct blkid_probe *pr,
  52                           blkid_loff_t off, size_t len)
  53 {
  54         ssize_t         ret_read;
  55         unsigned char   *newbuf;
  56
  57         if (off + len <= SB_BUFFER_SIZE) {
  58                 if (!pr->sbbuf) {
  59                         pr->sbbuf = malloc(SB_BUFFER_SIZE);
  60                         if (!pr->sbbuf)
  61                                 return NULL;
  62                         if (lseek(pr->fd, 0, SEEK_SET) < 0)
  63                                 return NULL;
  64                         ret_read = read(pr->fd, pr->sbbuf, SB_BUFFER_SIZE);
  65                         if (ret_read < 0)
  66                                 ret_read = 0;
  67                         pr->sb_valid = ret_read;
  68                 }
  69                 if (off+len > pr->sb_valid)
  70                         return NULL;
  71                 return pr->sbbuf + off;
  72         } else {
  73                 if (len > pr->buf_max) {
  74                         newbuf = realloc(pr->buf, len);
  75                         if (newbuf == NULL)
  76                                 return NULL;
  77                         pr->buf = newbuf;
  78                         pr->buf_max = len;
  79                 }
  80                 if (blkid_llseek(pr->fd, off, SEEK_SET) < 0)
  81                         return NULL;
  82                 ret_read = read(pr->fd, pr->buf, len);
  83                 if (ret_read != (ssize_t) len)
  84                         return NULL;
  85                 return pr->buf;
  86         }
  87 }
  88
  89
  90 /*
  91  * This is a special case code to check for an MDRAID device.  We do
  92  * this special since it requires checking for a superblock at the end
  93  * of the device.
  94  */
  95 static int check_mdraid(int fd, unsigned char *ret_uuid)
  96 {
  97         struct mdp_superblock_s *md;
  98         blkid_loff_t            offset;
  99         char                    buf[4096];
 100
 101         if (fd < 0)
 102                 return -BLKID_ERR_PARAM;
 103
 104         offset = (blkid_get_dev_size(fd) & ~((blkid_loff_t)65535)) - 65536;
 105
 106         if (blkid_llseek(fd, offset, 0) < 0 ||
 107             read(fd, buf, 4096) != 4096)
 108                 return -BLKID_ERR_IO;
 109
 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 (strlen(es->s_volume_name))
 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()
 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 = (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 = (reserved * sector_size) +
 605                                 (next * sizeof(__u32));
 606                         buf = get_buffer(probe, fat_entry_off, buf_size);
 607                         if (buf == NULL)
 608                                 break;
 609
 610                         /* set next cluster */
 611                         next = blkid_le32(*((__u32 *) buf) & 0x0fffffff);
 612                 }
 613
 614                 if (!vol_label || !memcmp(vol_label, no_name, 11))
 615                         vol_label = vs->vs_label;
 616                 vol_serno = vs->vs_serno;
 617         }
 618
 619         if (vol_label && memcmp(vol_label, no_name, 11)) {
 620                 if ((label_len = figure_label_len(vol_label, 11)))
 621                         label = vol_label;
 622         }
 623
 624         /* We can't just print them as %04X, because they are unaligned */
 625         sprintf(serno, "%02X%02X-%02X%02X", vol_serno[3], vol_serno[2],
 626                 vol_serno[1], vol_serno[0]);
 627
 628         blkid_set_tag(probe->dev, "LABEL", (const char *) label, label_len);
 629         blkid_set_tag(probe->dev, "UUID", serno, sizeof(serno)-1);
 630
 631         return 0;
 632 }
 633
 634 /*
 635  * The FAT filesystem could be without a magic string in superblock
 636  * (e.g. old floppies).  This heuristic for FAT detection is inspired
 637  * by http://vrfy.org/projects/volume_id/ and Linux kernel.
 638  * [7-Jul-2005, Karel Zak <kzak@redhat.com>]
 639  */
 640 static int probe_fat_nomagic(struct blkid_probe *probe,
 641                              struct blkid_magic *id __BLKID_ATTR((unused)),
 642                              unsigned char *buf)
 643 {
 644         struct msdos_super_block *ms;
 645
 646         ms = (struct msdos_super_block *)buf;
 647
 648         /* heads check */
 649         if (ms->ms_heads == 0)
 650                 return 1;
 651
 652         /* cluster size check*/
 653         if (ms->ms_cluster_size == 0 ||
 654             (ms->ms_cluster_size & (ms->ms_cluster_size-1)))
 655                 return 1;
 656
 657         /* media check */
 658         if (ms->ms_media < 0xf8 && ms->ms_media != 0xf0)
 659                 return 1;
 660
 661         /* fat counts(Linux kernel expects at least 1 FAT table) */
 662         if (!ms->ms_fats)
 663                 return 1;
 664
 665         /*
 666          * OS/2 and apparently DFSee will place a FAT12/16-like
 667          * pseudo-superblock in the first 512 bytes of non-FAT
 668          * filesystems --- at least JFS and HPFS, and possibly others.
 669          * So we explicitly check for those filesystems at the
 670          * FAT12/16 filesystem magic field identifier, and if they are
 671          * present, we rule this out as a FAT filesystem, despite the
 672          * FAT-like pseudo-header.
 673          */
 674         if ((memcmp(ms->ms_magic, "JFS     ", 8) == 0) ||
 675             (memcmp(ms->ms_magic, "HPFS    ", 8) == 0))
 676                 return 1;
 677
 678         return probe_fat(probe, id, buf);
 679 }
 680
 681 static int probe_ntfs(struct blkid_probe *probe,
 682                       struct blkid_magic *id __BLKID_ATTR((unused)),
 683                       unsigned char *buf)
 684 {
 685         struct ntfs_super_block *ns;
 686         struct master_file_table_record *mft;
 687         struct file_attribute *attr;
 688         char            uuid_str[17], label_str[129], *cp;
 689         int             bytes_per_sector, sectors_per_cluster;
 690         int             mft_record_size, attr_off, attr_len;
 691         unsigned int    i, attr_type, val_len;
 692         int             val_off;
 693         __u64           nr_clusters;
 694         blkid_loff_t off;
 695         unsigned char *buf_mft, *val;
 696
 697         ns = (struct ntfs_super_block *) buf;
 698
 699         bytes_per_sector = ns->bios_parameter_block[0] +
 700                 (ns->bios_parameter_block[1]  << 8);
 701         sectors_per_cluster = ns->bios_parameter_block[2];
 702
 703         if ((bytes_per_sector < 512) || (sectors_per_cluster == 0))
 704                 return 1;
 705
 706         if (ns->cluster_per_mft_record < 0)
 707                 mft_record_size = 1 << (0-ns->cluster_per_mft_record);
 708         else
 709                 mft_record_size = ns->cluster_per_mft_record *
 710                         sectors_per_cluster * bytes_per_sector;
 711         nr_clusters = blkid_le64(ns->number_of_sectors) / sectors_per_cluster;
 712
 713         if ((blkid_le64(ns->mft_cluster_location) > nr_clusters) ||
 714             (blkid_le64(ns->mft_mirror_cluster_location) > nr_clusters))
 715                 return 1;
 716
 717         off = blkid_le64(ns->mft_mirror_cluster_location) *
 718                 bytes_per_sector * sectors_per_cluster;
 719
 720         buf_mft = get_buffer(probe, off, mft_record_size);
 721         if (!buf_mft)
 722                 return 1;
 723
 724         if (memcmp(buf_mft, "FILE", 4))
 725                 return 1;
 726
 727         off = blkid_le64(ns->mft_cluster_location) * bytes_per_sector *
 728                 sectors_per_cluster;
 729
 730         buf_mft = get_buffer(probe, off, mft_record_size);
 731         if (!buf_mft)
 732                 return 1;
 733
 734         if (memcmp(buf_mft, "FILE", 4))
 735                 return 1;
 736
 737         off += MFT_RECORD_VOLUME * mft_record_size;
 738
 739         buf_mft = get_buffer(probe, off, mft_record_size);
 740         if (!buf_mft)
 741                 return 1;
 742
 743         if (memcmp(buf_mft, "FILE", 4))
 744                 return 1;
 745
 746         mft = (struct master_file_table_record *) buf_mft;
 747
 748         attr_off = blkid_le16(mft->attrs_offset);
 749         label_str[0] = 0;
 750
 751         while (1) {
 752                 attr = (struct file_attribute *) (buf_mft + attr_off);
 753                 attr_len = blkid_le16(attr->len);
 754                 attr_type = blkid_le32(attr->type);
 755                 val_off = blkid_le16(attr->value_offset);
 756                 val_len = blkid_le32(attr->value_len);
 757
 758                 attr_off += attr_len;
 759
 760                 if ((attr_off > mft_record_size) ||
 761                     (attr_len == 0))
 762                         break;
 763
 764                 if (attr_type == MFT_RECORD_ATTR_END)
 765                         break;
 766
 767                 if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
 768                         if (val_len > sizeof(label_str))
 769                                 val_len = sizeof(label_str)-1;
 770
 771                         for (i=0, cp=label_str; i < val_len; i+=2,cp++) {
 772                                 val = ((__u8 *) attr) + val_off + i;
 773                                 *cp = val[0];
 774                                 if (val[1])
 775                                         *cp = '?';
 776                         }
 777                         *cp = 0;
 778                 }
 779         }
 780
 781         sprintf(uuid_str, "%016llX", blkid_le64(ns->volume_serial));
 782         blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
 783         if (label_str[0])
 784                 blkid_set_tag(probe->dev, "LABEL", label_str, 0);
 785         return 0;
 786 }
 787
 788
 789 static int probe_xfs(struct blkid_probe *probe,
 790                      struct blkid_magic *id __BLKID_ATTR((unused)),
 791                      unsigned char *buf)
 792 {
 793         struct xfs_super_block *xs;
 794         const char *label = 0;
 795
 796         xs = (struct xfs_super_block *)buf;
 797
 798         if (strlen(xs->xs_fname))
 799                 label = xs->xs_fname;
 800         blkid_set_tag(probe->dev, "LABEL", label, sizeof(xs->xs_fname));
 801         set_uuid(probe->dev, xs->xs_uuid, 0);
 802         return 0;
 803 }
 804
 805 static int probe_reiserfs(struct blkid_probe *probe,
 806                           struct blkid_magic *id, unsigned char *buf)
 807 {
 808         struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
 809         unsigned int blocksize;
 810         const char *label = 0;
 811
 812         blocksize = blkid_le16(rs->rs_blocksize);
 813
 814         /* The blocksize must be at least 1k */
 815         if ((blocksize >> 10) == 0)
 816                 return -BLKID_ERR_PARAM;
 817
 818         /* If the superblock is inside the journal, we have the wrong one */
 819         if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
 820                 return -BLKID_ERR_BIG;
 821
 822         /* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
 823         if (id->bim_magic[6] == '2' || id->bim_magic[6] == '3') {
 824                 if (strlen(rs->rs_label))
 825                         label = rs->rs_label;
 826                 set_uuid(probe->dev, rs->rs_uuid, 0);
 827         }
 828         blkid_set_tag(probe->dev, "LABEL", label, sizeof(rs->rs_label));
 829
 830         return 0;
 831 }
 832
 833 static int probe_reiserfs4(struct blkid_probe *probe,
 834                            struct blkid_magic *id __BLKID_ATTR((unused)),
 835                            unsigned char *buf)
 836 {
 837         struct reiser4_super_block *rs4 = (struct reiser4_super_block *) buf;
 838         const unsigned char *label = 0;
 839
 840         if (strlen((char *) rs4->rs4_label))
 841                 label = rs4->rs4_label;
 842         set_uuid(probe->dev, rs4->rs4_uuid, 0);
 843         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 844                       sizeof(rs4->rs4_label));
 845
 846         return 0;
 847 }
 848
 849 static int probe_jfs(struct blkid_probe *probe,
 850                      struct blkid_magic *id __BLKID_ATTR((unused)),
 851                      unsigned char *buf)
 852 {
 853         struct jfs_super_block *js;
 854         const char *label = 0;
 855
 856         js = (struct jfs_super_block *)buf;
 857
 858         if (blkid_le32(js->js_bsize) != (1 << blkid_le16(js->js_l2bsize)))
 859                 return 1;
 860
 861         if (blkid_le32(js->js_pbsize) != (1 << blkid_le16(js->js_l2pbsize)))
 862                 return 1;
 863
 864         if ((blkid_le16(js->js_l2bsize) - blkid_le16(js->js_l2pbsize)) !=
 865             blkid_le16(js->js_l2bfactor))
 866                 return 1;
 867
 868         if (strlen((char *) js->js_label))
 869                 label = (char *) js->js_label;
 870         blkid_set_tag(probe->dev, "LABEL", label, sizeof(js->js_label));
 871         set_uuid(probe->dev, js->js_uuid, 0);
 872         return 0;
 873 }
 874
 875 static int probe_zfs(struct blkid_probe *probe, struct blkid_magic *id,
 876                      unsigned char *buf)
 877 {
 878 #if 0
 879         char *vdev_label;
 880         const char *pool_name = 0;
 881
 882         /* read nvpair data for pool name, pool GUID (complex) */
 883         blkid_set_tag(probe->dev, "LABEL", pool_name, sizeof(pool_name));
 884         set_uuid(probe->dev, pool_guid, 0);
 885 #endif
 886         return 0;
 887 }
 888
 889 static int probe_luks(struct blkid_probe *probe,
 890                        struct blkid_magic *id __BLKID_ATTR((unused)),
 891                        unsigned char *buf)
 892 {
 893         char uuid[40];
 894
 895         /* 168 is the offset to the 40 character uuid:
 896          * http://luks.endorphin.org/LUKS-on-disk-format.pdf */
 897         strncpy(uuid, (char *) buf+168, 40);
 898         blkid_set_tag(probe->dev, "UUID", uuid, sizeof(uuid));
 899         return 0;
 900 }
 901
 902 static int probe_romfs(struct blkid_probe *probe,
 903                        struct blkid_magic *id __BLKID_ATTR((unused)),
 904                        unsigned char *buf)
 905 {
 906         struct romfs_super_block *ros;
 907         const char *label = 0;
 908
 909         ros = (struct romfs_super_block *)buf;
 910
 911         if (strlen((char *) ros->ros_volume))
 912                 label = (char *) ros->ros_volume;
 913         blkid_set_tag(probe->dev, "LABEL", label, 0);
 914         return 0;
 915 }
 916
 917 static int probe_cramfs(struct blkid_probe *probe,
 918                         struct blkid_magic *id __BLKID_ATTR((unused)),
 919                         unsigned char *buf)
 920 {
 921         struct cramfs_super_block *csb;
 922         const char *label = 0;
 923
 924         csb = (struct cramfs_super_block *)buf;
 925
 926         if (strlen((char *) csb->name))
 927                 label = (char *) csb->name;
 928         blkid_set_tag(probe->dev, "LABEL", label, 0);
 929         return 0;
 930 }
 931
 932 static int probe_swap0(struct blkid_probe *probe,
 933                        struct blkid_magic *id __BLKID_ATTR((unused)),
 934                        unsigned char *buf __BLKID_ATTR((unused)))
 935 {
 936         blkid_set_tag(probe->dev, "UUID", 0, 0);
 937         blkid_set_tag(probe->dev, "LABEL", 0, 0);
 938         return 0;
 939 }
 940
 941 static int probe_swap1(struct blkid_probe *probe,
 942                        struct blkid_magic *id,
 943                        unsigned char *buf __BLKID_ATTR((unused)))
 944 {
 945         struct swap_id_block *sws;
 946
 947         probe_swap0(probe, id, buf);
 948         /*
 949          * Version 1 swap headers are always located at offset of 1024
 950          * bytes, although the swap signature itself is located at the
 951          * end of the page (which may vary depending on hardware
 952          * pagesize).
 953          */
 954         sws = (struct swap_id_block *) get_buffer(probe, 1024, 1024);
 955         if (!sws)
 956                 return 1;
 957
 958         /* check for wrong version or zeroed pagecount, for sanity */
 959         if (!memcmp(id->bim_magic, "SWAPSPACE2", id->bim_len) &&
 960                         (sws->sws_version != 1 || sws->sws_lastpage == 0))
 961                 return 1;
 962
 963         /* arbitrary sanity check.. is there any garbage down there? */
 964         if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0)  {
 965                 if (sws->sws_volume[0])
 966                         blkid_set_tag(probe->dev, "LABEL", sws->sws_volume,
 967                                       sizeof(sws->sws_volume));
 968                 if (sws->sws_uuid[0])
 969                         set_uuid(probe->dev, sws->sws_uuid, 0);
 970         }
 971         return 0;
 972 }
 973
 974 static int probe_iso9660(struct blkid_probe *probe,
 975                          struct blkid_magic *id __BLKID_ATTR((unused)),
 976                          unsigned char *buf)
 977 {
 978         struct iso_volume_descriptor *iso;
 979         const unsigned char *label;
 980
 981         iso = (struct iso_volume_descriptor *) buf;
 982         label = iso->volume_id;
 983
 984         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 985                       figure_label_len(label, 32));
 986         return 0;
 987 }
 988
 989
 990 static const char
 991 *udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
 992                  "NSR03", "TEA01", 0 };
 993
 994 static int probe_udf(struct blkid_probe *probe,
 995                      struct blkid_magic *id __BLKID_ATTR((unused)),
 996                      unsigned char *buf __BLKID_ATTR((unused)))
 997 {
 998         int j, bs;
 999         struct iso_volume_descriptor *isosb;
1000         const char ** m;
1001
1002         /* determine the block size by scanning in 2K increments
1003            (block sizes larger than 2K will be null padded) */
1004         for (bs = 1; bs < 16; bs++) {
1005                 isosb = (struct iso_volume_descriptor *)
1006                         get_buffer(probe, bs*2048+32768, sizeof(*isosb));
1007                 if (!isosb)
1008                         return 1;
1009                 if (isosb->vd_id[0])
1010                         break;
1011         }
1012
1013         /* Scan up to another 64 blocks looking for additional VSD's */
1014         for (j = 1; j < 64; j++) {
1015                 if (j > 1) {
1016                         isosb = (struct iso_volume_descriptor *)
1017                                 get_buffer(probe, j*bs*2048+32768,
1018                                            sizeof(*isosb));
1019                         if (!isosb)
1020                                 return 1;
1021                 }
1022                 /* If we find NSR0x then call it udf:
1023                    NSR01 for UDF 1.00
1024                    NSR02 for UDF 1.50
1025                    NSR03 for UDF 2.00 */
1026                 if (!memcmp(isosb->vd_id, "NSR0", 4))
1027                         return probe_iso9660(probe, id, buf);
1028                 for (m = udf_magic; *m; m++)
1029                         if (!memcmp(*m, isosb->vd_id, 5))
1030                                 break;
1031                 if (*m == 0)
1032                         return 1;
1033         }
1034         return 1;
1035 }
1036
1037 static int probe_ocfs(struct blkid_probe *probe,
1038                       struct blkid_magic *id __BLKID_ATTR((unused)),
1039                       unsigned char *buf)
1040 {
1041         struct ocfs_volume_header ovh;
1042         struct ocfs_volume_label ovl;
1043         __u32 major;
1044
1045         memcpy(&ovh, buf, sizeof(ovh));
1046         memcpy(&ovl, buf+512, sizeof(ovl));
1047
1048         major = ocfsmajor(ovh);
1049         if (major == 1)
1050                 blkid_set_tag(probe->dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
1051         else if (major >= 9)
1052                 blkid_set_tag(probe->dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
1053
1054         blkid_set_tag(probe->dev, "LABEL", ovl.label, ocfslabellen(ovl));
1055         blkid_set_tag(probe->dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
1056         set_uuid(probe->dev, ovl.vol_id, 0);
1057         return 0;
1058 }
1059
1060 static int probe_ocfs2(struct blkid_probe *probe,
1061                        struct blkid_magic *id __BLKID_ATTR((unused)),
1062                        unsigned char *buf)
1063 {
1064         struct ocfs2_super_block *osb;
1065
1066         osb = (struct ocfs2_super_block *)buf;
1067
1068         blkid_set_tag(probe->dev, "LABEL", osb->s_label, sizeof(osb->s_label));
1069         set_uuid(probe->dev, osb->s_uuid, 0);
1070         return 0;
1071 }
1072
1073 static int probe_oracleasm(struct blkid_probe *probe,
1074                            struct blkid_magic *id __BLKID_ATTR((unused)),
1075                            unsigned char *buf)
1076 {
1077         struct oracle_asm_disk_label *dl;
1078
1079         dl = (struct oracle_asm_disk_label *)buf;
1080
1081         blkid_set_tag(probe->dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
1082         return 0;
1083 }
1084
1085 static int probe_gfs(struct blkid_probe *probe,
1086                      struct blkid_magic *id __BLKID_ATTR((unused)),
1087                      unsigned char *buf)
1088 {
1089         struct gfs2_sb *sbd;
1090         const char *label = 0;
1091
1092         sbd = (struct gfs2_sb *)buf;
1093
1094         if (blkid_be32(sbd->sb_fs_format) == GFS_FORMAT_FS &&
1095             blkid_be32(sbd->sb_multihost_format) == GFS_FORMAT_MULTI)
1096         {
1097                 blkid_set_tag(probe->dev, "UUID", 0, 0);
1098
1099                 if (strlen(sbd->sb_locktable))
1100                         label = sbd->sb_locktable;
1101                 blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
1102                 return 0;
1103         }
1104         return 1;
1105 }
1106
1107 static int probe_gfs2(struct blkid_probe *probe,
1108                      struct blkid_magic *id __BLKID_ATTR((unused)),
1109                      unsigned char *buf)
1110 {
1111         struct gfs2_sb *sbd;
1112         const char *label = 0;
1113
1114         sbd = (struct gfs2_sb *)buf;
1115
1116         if (blkid_be32(sbd->sb_fs_format) == GFS2_FORMAT_FS &&
1117             blkid_be32(sbd->sb_multihost_format) == GFS2_FORMAT_MULTI)
1118         {
1119                 blkid_set_tag(probe->dev, "UUID", 0, 0);
1120
1121                 if (strlen(sbd->sb_locktable))
1122                         label = sbd->sb_locktable;
1123                 blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
1124                 return 0;
1125         }
1126         return 1;
1127 }
1128
1129 static void unicode_16be_to_utf8(unsigned char *str, int out_len,
1130                                  const unsigned char *buf, int in_len)
1131 {
1132         int i, j;
1133         unsigned int c;
1134
1135         for (i = j = 0; i + 2 <= in_len; i += 2) {
1136                 c = (buf[i] << 8) | buf[i+1];
1137                 if (c == 0) {
1138                         str[j] = '\0';
1139                         break;
1140                 } else if (c < 0x80) {
1141                         if (j+1 >= out_len)
1142                                 break;
1143                         str[j++] = (unsigned char) c;
1144                 } else if (c < 0x800) {
1145                         if (j+2 >= out_len)
1146                                 break;
1147                         str[j++] = (unsigned char) (0xc0 | (c >> 6));
1148                         str[j++] = (unsigned char) (0x80 | (c & 0x3f));
1149                 } else {
1150                         if (j+3 >= out_len)
1151                                 break;
1152                         str[j++] = (unsigned char) (0xe0 | (c >> 12));
1153                         str[j++] = (unsigned char) (0x80 | ((c >> 6) & 0x3f));
1154                         str[j++] = (unsigned char) (0x80 | (c & 0x3f));
1155                 }
1156         }
1157         str[j] = '\0';
1158 }
1159
1160 static int probe_hfs(struct blkid_probe *probe __BLKID_ATTR((unused)),
1161                          struct blkid_magic *id __BLKID_ATTR((unused)),
1162                          unsigned char *buf)
1163 {
1164         struct hfs_mdb *hfs = (struct hfs_mdb *)buf;
1165         unsigned long long *uuid_ptr;
1166         char    uuid_str[17];
1167         __u64   uuid;
1168
1169         if ((memcmp(hfs->embed_sig, "H+", 2) == 0) ||
1170             (memcmp(hfs->embed_sig, "HX", 2) == 0))
1171                 return 1;       /* Not hfs, but an embedded HFS+ */
1172
1173         uuid_ptr = (unsigned long long *)hfs->finder_info.id;
1174         uuid = blkid_le64(*uuid_ptr);
1175         if (uuid) {
1176                 sprintf(uuid_str, "%016llX", uuid);
1177                 blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
1178         }
1179         blkid_set_tag(probe->dev, "LABEL", (char *)hfs->label, hfs->label_len);
1180         return 0;
1181 }
1182
1183
1184 static int probe_hfsplus(struct blkid_probe *probe,
1185                          struct blkid_magic *id,
1186                          unsigned char *buf)
1187 {
1188         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
1189         struct hfsplus_bnode_descriptor *descr;
1190         struct hfsplus_bheader_record *bnode;
1191         struct hfsplus_catalog_key *key;
1192         struct hfsplus_vol_header *hfsplus;
1193         struct hfs_mdb *sbd = (struct hfs_mdb *) buf;
1194         unsigned int alloc_block_size;
1195         unsigned int alloc_first_block;
1196         unsigned int embed_first_block;
1197         unsigned int off = 0;
1198         unsigned int blocksize;
1199         unsigned int cat_block;
1200         unsigned int ext_block_start;
1201         unsigned int ext_block_count;
1202         unsigned int record_count;
1203         unsigned int leaf_node_head;
1204         unsigned int leaf_node_count;
1205         unsigned int leaf_node_size;
1206         unsigned int leaf_block;
1207         unsigned int label_len;
1208         unsigned long long *uuid_ptr;
1209         __u64 leaf_off, uuid;
1210         char    uuid_str[17], label[512];
1211         int ext;
1212
1213         /* Check for a HFS+ volume embedded in a HFS volume */
1214         if (memcmp(sbd->signature, "BD", 2) == 0) {
1215                 if ((memcmp(sbd->embed_sig, "H+", 2) != 0) &&
1216                     (memcmp(sbd->embed_sig, "HX", 2) != 0))
1217                         /* This must be an HFS volume, so fail */
1218                         return 1;
1219
1220                 alloc_block_size = blkid_be32(sbd->al_blk_size);
1221                 alloc_first_block = blkid_be16(sbd->al_bl_st);
1222                 embed_first_block = blkid_be16(sbd->embed_startblock);
1223                 off = (alloc_first_block * 512) +
1224                         (embed_first_block * alloc_block_size);
1225                 buf = get_buffer(probe, off + (id->bim_kboff * 1024),
1226                                  sizeof(*sbd));
1227                 if (!buf)
1228                         return 1;
1229
1230                 hfsplus = (struct hfsplus_vol_header *) buf;
1231         }
1232
1233         hfsplus = (struct hfsplus_vol_header *) buf;
1234
1235         if ((memcmp(hfsplus->signature, "H+", 2) != 0) &&
1236             (memcmp(hfsplus->signature, "HX", 2) != 0))
1237                 return 1;
1238
1239         uuid_ptr = (unsigned long long *)hfsplus->finder_info.id;
1240         uuid = blkid_le64(*uuid_ptr);
1241         if (uuid) {
1242                 sprintf(uuid_str, "%016llX", uuid);
1243                 blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
1244         }
1245
1246         blocksize = blkid_be32(hfsplus->blocksize);
1247         memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
1248         cat_block = blkid_be32(extents[0].start_block);
1249
1250         buf = get_buffer(probe, off + (cat_block * blocksize), 0x2000);
1251         if (!buf)
1252                 return 0;
1253
1254         bnode = (struct hfsplus_bheader_record *)
1255                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
1256
1257         leaf_node_head = blkid_be32(bnode->leaf_head);
1258         leaf_node_size = blkid_be16(bnode->node_size);
1259         leaf_node_count = blkid_be32(bnode->leaf_count);
1260         if (leaf_node_count == 0)
1261                 return 0;
1262
1263         leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
1264
1265         /* get physical location */
1266         for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
1267                 ext_block_start = blkid_be32(extents[ext].start_block);
1268                 ext_block_count = blkid_be32(extents[ext].block_count);
1269                 if (ext_block_count == 0)
1270                         return 0;
1271
1272                 /* this is our extent */
1273                 if (leaf_block < ext_block_count)
1274                         break;
1275
1276                 leaf_block -= ext_block_count;
1277         }
1278         if (ext == HFSPLUS_EXTENT_COUNT)
1279                 return 0;
1280
1281         leaf_off = (ext_block_start + leaf_block) * blocksize;
1282
1283         buf = get_buffer(probe, off + leaf_off, leaf_node_size);
1284         if (!buf)
1285                 return 0;
1286
1287         descr = (struct hfsplus_bnode_descriptor *) buf;
1288         record_count = blkid_be16(descr->num_recs);
1289         if (record_count == 0)
1290                 return 0;
1291
1292         if (descr->type != HFS_NODE_LEAF)
1293                 return 0;
1294
1295         key = (struct hfsplus_catalog_key *)
1296                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
1297
1298         if (blkid_be32(key->parent_id) != HFSPLUS_POR_CNID)
1299                 return 0;
1300
1301         label_len = blkid_be16(key->unicode_len) * 2;
1302         unicode_16be_to_utf8((unsigned char *)label, sizeof(label),
1303                              key->unicode, label_len);
1304         blkid_set_tag(probe->dev, "LABEL", label, 0);
1305         return 0;
1306 }
1307
1308 #define LVM2_LABEL_SIZE 512
1309 static unsigned int lvm2_calc_crc(const void *buf, unsigned int size)
1310 {
1311         static const unsigned int crctab[] = {
1312                 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
1313                 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
1314                 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
1315                 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
1316         };
1317         unsigned int i, crc = 0xf597a6cf;
1318         const __u8 *data = (const __u8 *) buf;
1319
1320         for (i = 0; i < size; i++) {
1321                 crc ^= *data++;
1322                 crc = (crc >> 4) ^ crctab[crc & 0xf];
1323                 crc = (crc >> 4) ^ crctab[crc & 0xf];
1324         }
1325         return crc;
1326 }
1327
1328 static int probe_lvm2(struct blkid_probe *probe,
1329                         struct blkid_magic *id,
1330                         unsigned char *buf)
1331 {
1332         int sector = (id->bim_kboff) << 1;
1333         struct lvm2_pv_label_header *label= (struct lvm2_pv_label_header *)buf;
1334         char *p, *q, uuid[40];
1335         unsigned int i, b;
1336
1337         /* buf is at 0k or 1k offset; find label inside */
1338         if (memcmp(buf, "LABELONE", 8) == 0) {
1339                 label = (struct lvm2_pv_label_header *)buf;
1340         } else if (memcmp(buf + 512, "LABELONE", 8) == 0) {
1341                 label = (struct lvm2_pv_label_header *)(buf + 512);
1342                 sector++;
1343         } else {
1344                 return 1;
1345         }
1346
1347         if (blkid_le64(label->sector_xl) != (unsigned) sector) {
1348                 DBG(DEBUG_PROBE,
1349                     printf("LVM2: label for sector %llu found at sector %d\n",
1350                            blkid_le64(label->sector_xl), sector));
1351                 return 1;
1352         }
1353
1354         if (lvm2_calc_crc(&label->offset_xl, LVM2_LABEL_SIZE -
1355                           ((char *)&label->offset_xl - (char *)label)) !=
1356                         blkid_le32(label->crc_xl)) {
1357                 DBG(DEBUG_PROBE,
1358                     printf("LVM2: label checksum incorrect at sector %d\n",
1359                            sector));
1360                 return 1;
1361         }
1362
1363         for (i=0, b=1, p=uuid, q= (char *) label->pv_uuid; i < LVM2_ID_LEN;
1364              i++, b <<= 1) {
1365                 if (b & 0x4444440)
1366                         *p++ = '-';
1367                 *p++ = *q++;
1368         }
1369
1370         blkid_set_tag(probe->dev, "UUID", uuid, LVM2_ID_LEN+6);
1371
1372         return 0;
1373 }
1374
1375 static int probe_btrfs(struct blkid_probe *probe,
1376                         struct blkid_magic *id,
1377                         unsigned char *buf)
1378 {
1379         struct btrfs_super_block *bs;
1380         const char *label = 0;
1381
1382         bs = (struct btrfs_super_block *)buf;
1383
1384         if (strlen(bs->label))
1385                 label = bs->label;
1386         blkid_set_tag(probe->dev, "LABEL", label, sizeof(bs->label));
1387         set_uuid(probe->dev, bs->fsid, 0);
1388         return 0;
1389 }
1390 /*
1391  * Various filesystem magics that we can check for.  Note that kboff and
1392  * sboff are in kilobytes and bytes respectively.  All magics are in
1393  * byte strings so we don't worry about endian issues.
1394  */
1395 static struct blkid_magic type_array[] = {
1396 /*  type     kboff   sboff len  magic                   probe */
1397   { "oracleasm", 0,     32,  8, "ORCLDISK",             probe_oracleasm },
1398   { "ntfs",      0,      3,  8, "NTFS    ",             probe_ntfs },
1399   { "jbd",       1,   0x38,  2, "\123\357",             probe_jbd },
1400   { "ext4dev",   1,   0x38,  2, "\123\357",             probe_ext4dev },
1401   { "ext4",      1,   0x38,  2, "\123\357",             probe_ext4 },
1402   { "ext3",      1,   0x38,  2, "\123\357",             probe_ext3 },
1403   { "ext2",      1,   0x38,  2, "\123\357",             probe_ext2 },
1404   { "reiserfs",  8,   0x34,  8, "ReIsErFs",             probe_reiserfs },
1405   { "reiserfs", 64,   0x34,  9, "ReIsEr2Fs",            probe_reiserfs },
1406   { "reiserfs", 64,   0x34,  9, "ReIsEr3Fs",            probe_reiserfs },
1407   { "reiserfs", 64,   0x34,  8, "ReIsErFs",             probe_reiserfs },
1408   { "reiserfs",  8,     20,  8, "ReIsErFs",             probe_reiserfs },
1409   { "reiser4",  64,      0,  7, "ReIsEr4",              probe_reiserfs4 },
1410   { "gfs2",     64,      0,  4, "\x01\x16\x19\x70",     probe_gfs2 },
1411   { "gfs",      64,      0,  4, "\x01\x16\x19\x70",     probe_gfs },
1412   { "vfat",      0,   0x52,  5, "MSWIN",                probe_fat },
1413   { "vfat",      0,   0x52,  8, "FAT32   ",             probe_fat },
1414   { "vfat",      0,   0x36,  5, "MSDOS",                probe_fat },
1415   { "vfat",      0,   0x36,  8, "FAT16   ",             probe_fat },
1416   { "vfat",      0,   0x36,  8, "FAT12   ",             probe_fat },
1417   { "vfat",      0,      0,  1, "\353",                 probe_fat_nomagic },
1418   { "vfat",      0,      0,  1, "\351",                 probe_fat_nomagic },
1419   { "vfat",      0,  0x1fe,  2, "\125\252",             probe_fat_nomagic },
1420   { "minix",     1,   0x10,  2, "\177\023",             0 },
1421   { "minix",     1,   0x10,  2, "\217\023",             0 },
1422   { "minix",     1,   0x10,  2, "\150\044",             0 },
1423   { "minix",     1,   0x10,  2, "\170\044",             0 },
1424   { "vxfs",      1,      0,  4, "\365\374\001\245",     0 },
1425   { "xfs",       0,      0,  4, "XFSB",                 probe_xfs },
1426   { "romfs",     0,      0,  8, "-rom1fs-",             probe_romfs },
1427   { "bfs",       0,      0,  4, "\316\372\173\033",     0 },
1428   { "cramfs",    0,      0,  4, "E=\315\050",           probe_cramfs },
1429   { "qnx4",      0,      4,  6, "QNX4FS",               0 },
1430   { "udf",      32,      1,  5, "BEA01",                probe_udf },
1431   { "udf",      32,      1,  5, "BOOT2",                probe_udf },
1432   { "udf",      32,      1,  5, "CD001",                probe_udf },
1433   { "udf",      32,      1,  5, "CDW02",                probe_udf },
1434   { "udf",      32,      1,  5, "NSR02",                probe_udf },
1435   { "udf",      32,      1,  5, "NSR03",                probe_udf },
1436   { "udf",      32,      1,  5, "TEA01",                probe_udf },
1437   { "iso9660",  32,      1,  5, "CD001",                probe_iso9660 },
1438   { "iso9660",  32,      9,  5, "CDROM",                probe_iso9660 },
1439   { "jfs",      32,      0,  4, "JFS1",                 probe_jfs },
1440   { "zfs",       8,      0,  8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", probe_zfs },
1441   { "zfs",       8,      0,  8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", probe_zfs },
1442   { "zfs",     264,      0,  8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", probe_zfs },
1443   { "zfs",     264,      0,  8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", probe_zfs },
1444   { "hfsplus",   1,      0,  2, "BD",                   probe_hfsplus },
1445   { "hfsplus",   1,      0,  2, "H+",                   probe_hfsplus },
1446   { "hfsplus",   1,      0,  2, "HX",                   probe_hfsplus },
1447   { "hfs",       1,      0,  2, "BD",                   probe_hfs },
1448   { "ufs",       8,  0x55c,  4, "T\031\001\000",        0 },
1449   { "hpfs",      8,      0,  4, "I\350\225\371",        0 },
1450   { "sysv",      0,  0x3f8,  4, "\020~\030\375",        0 },
1451   { "swap",      0,  0xff6, 10, "SWAP-SPACE",           probe_swap0 },
1452   { "swap",      0,  0xff6, 10, "SWAPSPACE2",           probe_swap1 },
1453   { "swsuspend", 0,  0xff6,  9, "S1SUSPEND",            probe_swap1 },
1454   { "swsuspend", 0,  0xff6,  9, "S2SUSPEND",            probe_swap1 },
1455   { "swsuspend", 0,  0xff6,  9, "ULSUSPEND",            probe_swap1 },
1456   { "swap",      0, 0x1ff6, 10, "SWAP-SPACE",           probe_swap0 },
1457   { "swap",      0, 0x1ff6, 10, "SWAPSPACE2",           probe_swap1 },
1458   { "swsuspend", 0, 0x1ff6,  9, "S1SUSPEND",            probe_swap1 },
1459   { "swsuspend", 0, 0x1ff6,  9, "S2SUSPEND",            probe_swap1 },
1460   { "swsuspend", 0, 0x1ff6,  9, "ULSUSPEND",            probe_swap1 },
1461   { "swap",      0, 0x3ff6, 10, "SWAP-SPACE",           probe_swap0 },
1462   { "swap",      0, 0x3ff6, 10, "SWAPSPACE2",           probe_swap1 },
1463   { "swsuspend", 0, 0x3ff6,  9, "S1SUSPEND",            probe_swap1 },
1464   { "swsuspend", 0, 0x3ff6,  9, "S2SUSPEND",            probe_swap1 },
1465   { "swsuspend", 0, 0x3ff6,  9, "ULSUSPEND",            probe_swap1 },
1466   { "swap",      0, 0x7ff6, 10, "SWAP-SPACE",           probe_swap0 },
1467   { "swap",      0, 0x7ff6, 10, "SWAPSPACE2",           probe_swap1 },
1468   { "swsuspend", 0, 0x7ff6,  9, "S1SUSPEND",            probe_swap1 },
1469   { "swsuspend", 0, 0x7ff6,  9, "S2SUSPEND",            probe_swap1 },
1470   { "swsuspend", 0, 0x7ff6,  9, "ULSUSPEND",            probe_swap1 },
1471   { "swap",      0, 0xfff6, 10, "SWAP-SPACE",           probe_swap0 },
1472   { "swap",      0, 0xfff6, 10, "SWAPSPACE2",           probe_swap1 },
1473   { "swsuspend", 0, 0xfff6,  9, "S1SUSPEND",            probe_swap1 },
1474   { "swsuspend", 0, 0xfff6,  9, "S2SUSPEND",            probe_swap1 },
1475   { "swsuspend", 0, 0xfff6,  9, "ULSUSPEND",            probe_swap1 },
1476   { "ocfs",      0,      8,  9, "OracleCFS",            probe_ocfs },
1477   { "ocfs2",     1,      0,  6, "OCFSV2",               probe_ocfs2 },
1478   { "ocfs2",     2,      0,  6, "OCFSV2",               probe_ocfs2 },
1479   { "ocfs2",     4,      0,  6, "OCFSV2",               probe_ocfs2 },
1480   { "ocfs2",     8,      0,  6, "OCFSV2",               probe_ocfs2 },
1481   { "crypt_LUKS", 0,     0,  6, "LUKS\xba\xbe",         probe_luks },
1482   { "squashfs",  0,      0,  4, "sqsh",                 0 },
1483   { "squashfs",  0,      0,  4, "hsqs",                 0 },
1484   { "lvm2pv",    0,  0x218,  8, "LVM2 001",             probe_lvm2 },
1485   { "lvm2pv",    0,  0x018,  8, "LVM2 001",             probe_lvm2 },
1486   { "lvm2pv",    1,  0x018,  8, "LVM2 001",             probe_lvm2 },
1487   { "lvm2pv",    1,  0x218,  8, "LVM2 001",             probe_lvm2 },
1488   { "btrfs",     64,  0x40,  8, "_BHRfS_M",             probe_btrfs },
1489   {   NULL,      0,      0,  0, NULL,                   NULL }
1490 };
1491
1492 /*
1493  * Verify that the data in dev is consistent with what is on the actual
1494  * block device (using the devname field only).  Normally this will be
1495  * called when finding items in the cache, but for long running processes
1496  * is also desirable to revalidate an item before use.
1497  *
1498  * If we are unable to revalidate the data, we return the old data and
1499  * do not set the BLKID_BID_FL_VERIFIED flag on it.
1500  */
1501 blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
1502 {
1503         struct blkid_magic *id;
1504         struct blkid_probe probe;
1505         blkid_tag_iterate iter;
1506         unsigned char *buf;
1507         const char *type, *value;
1508         struct stat st;
1509         time_t diff, now;
1510         int idx;
1511
1512         if (!dev)
1513                 return NULL;
1514
1515         now = time(0);
1516         diff = now - dev->bid_time;
1517
1518         if (stat(dev->bid_name, &st) < 0) {
1519                 DBG(DEBUG_PROBE,
1520                     printf("blkid_verify: error %s (%d) while "
1521                            "trying to stat %s\n", strerror(errno), errno,
1522                            dev->bid_name));
1523         open_err:
1524                 if ((errno == EPERM) || (errno == EACCES) || (errno == ENOENT)) {
1525                         /* We don't have read permission, just return cache data. */
1526                         DBG(DEBUG_PROBE, printf("returning unverified data for %s\n",
1527                                                 dev->bid_name));
1528                         return dev;
1529                 }
1530                 blkid_free_dev(dev);
1531                 return NULL;
1532         }
1533
1534         if ((now >= dev->bid_time) &&
1535             (st.st_mtime <= dev->bid_time) &&
1536             ((diff < BLKID_PROBE_MIN) ||
1537              (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
1538               diff < BLKID_PROBE_INTERVAL)))
1539                 return dev;
1540
1541         DBG(DEBUG_PROBE,
1542             printf("need to revalidate %s (cache time %lu, stat time %lu,\n\t"
1543                    "time since last check %lu)\n",
1544                    dev->bid_name, (unsigned long)dev->bid_time,
1545                    (unsigned long)st.st_mtime, (unsigned long)diff));
1546
1547         if ((probe.fd = open(dev->bid_name, O_RDONLY)) < 0) {
1548                 DBG(DEBUG_PROBE, printf("blkid_verify: error %s (%d) while "
1549                                         "opening %s\n", strerror(errno), errno,
1550                                         dev->bid_name));
1551                 goto open_err;
1552         }
1553
1554         probe.cache = cache;
1555         probe.dev = dev;
1556         probe.sbbuf = 0;
1557         probe.buf = 0;
1558         probe.buf_max = 0;
1559
1560         /*
1561          * Iterate over the type array.  If we already know the type,
1562          * then try that first.  If it doesn't work, then blow away
1563          * the type information, and try again.
1564          *
1565          */
1566 try_again:
1567         type = 0;
1568         if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
1569                 uuid_t  uuid;
1570
1571                 if (check_mdraid(probe.fd, uuid) == 0) {
1572                         set_uuid(dev, uuid, 0);
1573                         type = "mdraid";
1574                         goto found_type;
1575                 }
1576         }
1577         for (id = type_array; id->bim_type; id++) {
1578                 if (dev->bid_type &&
1579                     strcmp(id->bim_type, dev->bid_type))
1580                         continue;
1581
1582                 idx = id->bim_kboff + (id->bim_sboff >> 10);
1583                 buf = get_buffer(&probe, idx << 10, 1024);
1584                 if (!buf)
1585                         continue;
1586
1587                 if (memcmp(id->bim_magic, buf + (id->bim_sboff & 0x3ff),
1588                            id->bim_len))
1589                         continue;
1590
1591                 if ((id->bim_probe == NULL) ||
1592                     (id->bim_probe(&probe, id, buf) == 0)) {
1593                         type = id->bim_type;
1594                         goto found_type;
1595                 }
1596         }
1597
1598         if (!id->bim_type && dev->bid_type) {
1599                 /*
1600                  * Zap the device filesystem information and try again
1601                  */
1602                 DBG(DEBUG_PROBE,
1603                     printf("previous fs type %s not valid, "
1604                            "trying full probe\n", dev->bid_type));
1605                 iter = blkid_tag_iterate_begin(dev);
1606                 while (blkid_tag_next(iter, &type, &value) == 0)
1607                         blkid_set_tag(dev, type, 0, 0);
1608                 blkid_tag_iterate_end(iter);
1609                 goto try_again;
1610         }
1611
1612         if (!dev->bid_type) {
1613                 blkid_free_dev(dev);
1614                 dev = 0;
1615                 goto found_type;
1616         }
1617
1618 found_type:
1619         if (dev && type) {
1620                 dev->bid_devno = st.st_rdev;
1621                 dev->bid_time = time(0);
1622                 dev->bid_flags |= BLKID_BID_FL_VERIFIED;
1623                 cache->bic_flags |= BLKID_BIC_FL_CHANGED;
1624
1625                 blkid_set_tag(dev, "TYPE", type, 0);
1626
1627                 DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
1628                            dev->bid_name, (long long)st.st_rdev, type));
1629         }
1630
1631         free(probe.sbbuf);
1632         free(probe.buf);
1633         if (probe.fd >= 0)
1634                 close(probe.fd);
1635
1636         return dev;
1637 }
1638
1639 int blkid_known_fstype(const char *fstype)
1640 {
1641         struct blkid_magic *id;
1642
1643         for (id = type_array; id->bim_type; id++) {
1644                 if (strcmp(fstype, id->bim_type) == 0)
1645                         return 1;
1646         }
1647         return 0;
1648 }
1649
1650 #ifdef TEST_PROGRAM
1651 int main(int argc, char **argv)
1652 {
1653         blkid_dev dev;
1654         blkid_cache cache;
1655         int ret;
1656
1657         if (argc != 2) {
1658                 fprintf(stderr, "Usage: %s device\n"
1659                         "Probe a single device to determine type\n", argv[0]);
1660                 exit(1);
1661         }
1662         if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
1663                 fprintf(stderr, "%s: error creating cache (%d)\n",
1664                         argv[0], ret);
1665                 exit(1);
1666         }
1667         dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
1668         if (!dev) {
1669                 printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
1670                 return (1);
1671         }
1672         printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");
1673         if (dev->bid_label)
1674                 printf("LABEL='%s'\n", dev->bid_label);
1675         if (dev->bid_uuid)
1676                 printf("UUID='%s'\n", dev->bid_uuid);
1677
1678         blkid_free_dev(dev);
1679         return (0);
1680 }
1681 #endif