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 <sys/types.h>
  22 #ifdef HAVE_SYS_STAT_H
  23 #include <sys/stat.h>
  24 #endif
  25 #ifdef HAVE_SYS_MKDEV_H
  26 #include <sys/mkdev.h>
  27 #endif
  28 #ifdef HAVE_ERRNO_H
  29 #include <errno.h>
  30 #endif
  31 #include "blkidP.h"
  32 #include "uuid/uuid.h"
  33 #include "probe.h"
  34
  35 static int figure_label_len(const unsigned char *label, int len)
  36 {
  37         const unsigned char *end = label + len - 1;
  38
  39         while ((*end == ' ' || *end == 0) && end >= label)
  40                 --end;
  41         if (end >= label) {
  42                 label = label;
  43                 return end - label + 1;
  44         }
  45         return 0;
  46 }
  47
  48 static unsigned char *get_buffer(struct blkid_probe *pr,
  49                           unsigned off, size_t len)
  50 {
  51         ssize_t         ret_read;
  52         unsigned char   *newbuf;
  53
  54         if (off + len <= SB_BUFFER_SIZE) {
  55                 if (!pr->sbbuf) {
  56                         pr->sbbuf = malloc(SB_BUFFER_SIZE);
  57                         if (!pr->sbbuf)
  58                                 return NULL;
  59                         if (lseek(pr->fd, 0, SEEK_SET) < 0)
  60                                 return NULL;
  61                         ret_read = read(pr->fd, pr->sbbuf, SB_BUFFER_SIZE);
  62                         if (ret_read < 0)
  63                                 ret_read = 0;
  64                         pr->sb_valid = ret_read;
  65                 }
  66                 if (off+len > pr->sb_valid)
  67                         return NULL;
  68                 return pr->sbbuf + off;
  69         } else {
  70                 if (len > pr->buf_max) {
  71                         newbuf = realloc(pr->buf, len);
  72                         if (newbuf == NULL)
  73                                 return NULL;
  74                         pr->buf = newbuf;
  75                         pr->buf_max = len;
  76                 }
  77                 if (lseek(pr->fd, off, SEEK_SET) < 0)
  78                         return NULL;
  79                 ret_read = read(pr->fd, pr->buf, len);
  80                 if (ret_read != (ssize_t) len)
  81                         return NULL;
  82                 return pr->buf;
  83         }
  84 }
  85
  86
  87 /*
  88  * This is a special case code to check for an MDRAID device.  We do
  89  * this special since it requires checking for a superblock at the end
  90  * of the device.
  91  */
  92 static int check_mdraid(int fd, unsigned char *ret_uuid)
  93 {
  94         struct mdp_superblock_s *md;
  95         blkid_loff_t            offset;
  96         char                    buf[4096];
  97
  98         if (fd < 0)
  99                 return -BLKID_ERR_PARAM;
 100
 101         offset = (blkid_get_dev_size(fd) & ~((blkid_loff_t)65535)) - 65536;
 102
 103         if (blkid_llseek(fd, offset, 0) < 0 ||
 104             read(fd, buf, 4096) != 4096)
 105                 return -BLKID_ERR_IO;
 106
 107         /* Check for magic number */
 108         if (memcmp("\251+N\374", buf, 4))
 109                 return -BLKID_ERR_PARAM;
 110
 111         if (!ret_uuid)
 112                 return 0;
 113         *ret_uuid = 0;
 114
 115         /* The MD UUID is not contiguous in the superblock, make it so */
 116         md = (struct mdp_superblock_s *)buf;
 117         if (md->set_uuid0 || md->set_uuid1 || md->set_uuid2 || md->set_uuid3) {
 118                 memcpy(ret_uuid, &md->set_uuid0, 4);
 119                 memcpy(ret_uuid, &md->set_uuid1, 12);
 120         }
 121         return 0;
 122 }
 123
 124 static void set_uuid(blkid_dev dev, uuid_t uuid, char *tag)
 125 {
 126         char    str[37];
 127
 128         if (!uuid_is_null(uuid)) {
 129                 uuid_unparse(uuid, str);
 130                 blkid_set_tag(dev, tag ? tag : "UUID", str, sizeof(str));
 131         }
 132 }
 133
 134 static void get_ext2_info(blkid_dev dev, unsigned char *buf)
 135 {
 136         struct ext2_super_block *es = (struct ext2_super_block *) buf;
 137         const char *label = 0;
 138
 139         DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",
 140                    blkid_le32(es->s_feature_compat),
 141                    blkid_le32(es->s_feature_incompat),
 142                    blkid_le32(es->s_feature_ro_compat)));
 143
 144         if (strlen(es->s_volume_name))
 145                 label = es->s_volume_name;
 146         blkid_set_tag(dev, "LABEL", label, sizeof(es->s_volume_name));
 147
 148         set_uuid(dev, es->s_uuid, 0);
 149 }
 150
 151 static int probe_ext3(struct blkid_probe *probe,
 152                       struct blkid_magic *id __BLKID_ATTR((unused)),
 153                       unsigned char *buf)
 154 {
 155         struct ext2_super_block *es;
 156         es = (struct ext2_super_block *)buf;
 157
 158         /* Distinguish between jbd and ext2/3 fs */
 159         if (blkid_le32(es->s_feature_incompat) &
 160             EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
 161                 return -BLKID_ERR_PARAM;
 162
 163         /* Distinguish between ext3 and ext2 */
 164         if (!(blkid_le32(es->s_feature_compat) &
 165               EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 166                 return -BLKID_ERR_PARAM;
 167
 168         get_ext2_info(probe->dev, buf);
 169
 170         if ((es->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
 171             !uuid_is_null(es->s_journal_uuid))
 172                 set_uuid(probe->dev, es->s_journal_uuid, "EXT_JOURNAL");
 173
 174         blkid_set_tag(probe->dev, "SEC_TYPE", "ext2", sizeof("ext2"));
 175
 176         return 0;
 177 }
 178
 179 static int probe_ext2(struct blkid_probe *probe,
 180                       struct blkid_magic *id __BLKID_ATTR((unused)),
 181                       unsigned char *buf)
 182 {
 183         struct ext2_super_block *es;
 184
 185         es = (struct ext2_super_block *)buf;
 186
 187         /* Distinguish between jbd and ext2/3 fs */
 188         if (blkid_le32(es->s_feature_incompat) &
 189             EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
 190                 return -BLKID_ERR_PARAM;
 191
 192         /* Distinguish between ext3 and ext2 */
 193         if ((blkid_le32(es->s_feature_compat) &
 194               EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 195                 return -BLKID_ERR_PARAM;
 196
 197         get_ext2_info(probe->dev, buf);
 198
 199         return 0;
 200 }
 201
 202 static int probe_jbd(struct blkid_probe *probe,
 203                      struct blkid_magic *id __BLKID_ATTR((unused)),
 204                      unsigned char *buf)
 205 {
 206         struct ext2_super_block *es = (struct ext2_super_block *) buf;
 207
 208         if (!(blkid_le32(es->s_feature_incompat) &
 209               EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
 210                 return -BLKID_ERR_PARAM;
 211
 212         get_ext2_info(probe->dev, buf);
 213
 214         return 0;
 215 }
 216
 217 #define FAT_ATTR_VOLUME_ID              0x08
 218 #define FAT_ATTR_DIR                    0x10
 219 #define FAT_ATTR_LONG_NAME              0x0f
 220 #define FAT_ATTR_MASK                   0x3f
 221 #define FAT_ENTRY_FREE                  0xe5
 222
 223 static char *no_name = "NO NAME    ";
 224
 225 static unsigned char *search_fat_label(struct vfat_dir_entry *dir, int count)
 226 {
 227         unsigned int i;
 228
 229         for (i = 0; i < count; i++) {
 230                 if (dir[i].name[0] == 0x00)
 231                         break;
 232
 233                 if ((dir[i].name[0] == FAT_ENTRY_FREE) ||
 234                     (dir[i].cluster_high != 0 || dir[i].cluster_low != 0) ||
 235                     ((dir[i].attr & FAT_ATTR_MASK) == FAT_ATTR_LONG_NAME))
 236                         continue;
 237
 238                 if ((dir[i].attr & (FAT_ATTR_VOLUME_ID | FAT_ATTR_DIR)) ==
 239                     FAT_ATTR_VOLUME_ID) {
 240                         return dir[i].name;
 241                 }
 242         }
 243         return 0;
 244 }
 245
 246 /* FAT label extraction from the root directory taken from Kay
 247  * Sievers's volume_id library */
 248 static int probe_fat(struct blkid_probe *probe,
 249                       struct blkid_magic *id __BLKID_ATTR((unused)),
 250                       unsigned char *buf)
 251 {
 252         struct vfat_super_block *vs = (struct vfat_super_block *) buf;
 253         struct msdos_super_block *ms = (struct msdos_super_block *) buf;
 254         struct vfat_dir_entry *dir;
 255         char serno[10];
 256         const unsigned char *label = 0, *vol_label = 0;
 257         unsigned char   *vol_serno;
 258         int label_len = 0, maxloop = 100;
 259         __u16 sector_size, dir_entries, reserved;
 260         __u32 sect_count, fat_size, dir_size, cluster_count, fat_length;
 261         __u32 buf_size, start_data_sect, next, root_start, root_dir_entries;
 262
 263         /* sector size check */
 264         sector_size = blkid_le16(*((__u16 *) &ms->ms_sector_size));
 265         if (sector_size != 0x200 && sector_size != 0x400 &&
 266             sector_size != 0x800 && sector_size != 0x1000)
 267                 return 1;
 268
 269         dir_entries = blkid_le16(*((__u16 *) &ms->ms_dir_entries));
 270         reserved =  blkid_le16(ms->ms_reserved);
 271         sect_count = blkid_le16(*((__u16 *) &ms->ms_sectors));
 272         if (sect_count == 0)
 273                 sect_count = blkid_le32(ms->ms_total_sect);
 274
 275         fat_length = blkid_le16(ms->ms_fat_length);
 276         if (fat_length == 0)
 277                 fat_length = blkid_le32(vs->vs_fat32_length);
 278
 279         fat_size = fat_length * ms->ms_fats;
 280         dir_size = ((dir_entries * sizeof(struct vfat_dir_entry)) +
 281                         (sector_size-1)) / sector_size;
 282
 283         cluster_count = sect_count - (reserved + fat_size + dir_size);
 284         cluster_count /= ms->ms_cluster_size;
 285
 286         if (cluster_count > FAT32_MAX)
 287                 return 1;
 288
 289         if (ms->ms_fat_length) {
 290                 /* the label may be an attribute in the root directory */
 291                 root_start = (reserved + fat_size) * sector_size;
 292                 root_dir_entries = vs->vs_dir_entries[0] +
 293                         (vs->vs_dir_entries[1] << 8);
 294
 295                 buf_size = root_dir_entries * sizeof(struct vfat_dir_entry);
 296                 dir = (struct vfat_dir_entry *) get_buffer(probe, root_start,
 297                                                            buf_size);
 298                 if (dir)
 299                         vol_label = search_fat_label(dir, root_dir_entries);
 300
 301                 if (!vol_label || !memcmp(vol_label, no_name, 11))
 302                         vol_label = ms->ms_label;
 303                 vol_serno = ms->ms_serno;
 304
 305                 blkid_set_tag(probe->dev, "SEC_TYPE", "msdos",
 306                               sizeof("msdos"));
 307         } else {
 308                 /* Search the FAT32 root dir for the label attribute */
 309                 buf_size = vs->vs_cluster_size * sector_size;
 310                 start_data_sect = reserved + fat_size;
 311
 312                 next = blkid_le32(vs->vs_root_cluster);
 313                 while (next && --maxloop) {
 314                         __u32 next_sect_off;
 315                         __u64 next_off, fat_entry_off;
 316                         int count;
 317
 318                         next_sect_off = (next - 2) * vs->vs_cluster_size;
 319                         next_off = (start_data_sect + next_sect_off) *
 320                                 sector_size;
 321
 322                         dir = (struct vfat_dir_entry *)
 323                                 get_buffer(probe, next_off, buf_size);
 324                         if (dir == NULL)
 325                                 break;
 326
 327                         count = buf_size / sizeof(struct vfat_dir_entry);
 328
 329                         vol_label = search_fat_label(dir, count);
 330                         if (vol_label)
 331                                 break;
 332
 333                         /* get FAT entry */
 334                         fat_entry_off = (reserved * sector_size) +
 335                                 (next * sizeof(__u32));
 336                         buf = get_buffer(probe, fat_entry_off, buf_size);
 337                         if (buf == NULL)
 338                                 break;
 339
 340                         /* set next cluster */
 341                         next = blkid_le32(*((__u32 *) buf) & 0x0fffffff);
 342                 }
 343
 344                 if (!vol_label || !memcmp(vol_label, no_name, 11))
 345                         vol_label = vs->vs_label;
 346                 vol_serno = vs->vs_serno;
 347         }
 348
 349         if (vol_label && memcmp(vol_label, no_name, 11)) {
 350                 label = vol_label;
 351                 label_len = figure_label_len(vol_label, 11);
 352         }
 353
 354         /* We can't just print them as %04X, because they are unaligned */
 355         sprintf(serno, "%02X%02X-%02X%02X", vol_serno[3], vol_serno[2],
 356                 vol_serno[1], vol_serno[0]);
 357
 358         blkid_set_tag(probe->dev, "LABEL", (const char *) label, label_len);
 359         blkid_set_tag(probe->dev, "UUID", serno, sizeof(serno)-1);
 360
 361         return 0;
 362 }
 363
 364 /*
 365  * The FAT filesystem could be without a magic string in superblock
 366  * (e.g. old floppies).  This heuristic for FAT detection is inspired
 367  * by http://vrfy.org/projects/volume_id/ and Linux kernel.
 368  * [7-Jul-2005, Karel Zak <kzak@redhat.com>]
 369  */
 370 static int probe_fat_nomagic(struct blkid_probe *probe,
 371                              struct blkid_magic *id __BLKID_ATTR((unused)),
 372                              unsigned char *buf)
 373 {
 374         struct vfat_super_block *vs;
 375
 376         vs = (struct vfat_super_block *)buf;
 377
 378         /* heads check */
 379         if (vs->vs_heads == 0)
 380                 return 1;
 381
 382         /* cluster size check*/
 383         if (vs->vs_cluster_size == 0 ||
 384             (vs->vs_cluster_size & (vs->vs_cluster_size-1)))
 385                 return 1;
 386
 387         /* media check */
 388         if (vs->vs_media < 0xf8 && vs->vs_media != 0xf0)
 389                 return 1;
 390
 391         /* fat counts(Linux kernel expects at least 1 FAT table) */
 392         if (!vs->vs_fats)
 393                 return 1;
 394
 395         return probe_fat(probe, id, buf);
 396 }
 397
 398 static int probe_xfs(struct blkid_probe *probe,
 399                      struct blkid_magic *id __BLKID_ATTR((unused)),
 400                      unsigned char *buf)
 401 {
 402         struct xfs_super_block *xs;
 403         const char *label = 0;
 404
 405         xs = (struct xfs_super_block *)buf;
 406
 407         if (strlen(xs->xs_fname))
 408                 label = xs->xs_fname;
 409         blkid_set_tag(probe->dev, "LABEL", label, sizeof(xs->xs_fname));
 410         set_uuid(probe->dev, xs->xs_uuid, 0);
 411         return 0;
 412 }
 413
 414 static int probe_reiserfs(struct blkid_probe *probe,
 415                           struct blkid_magic *id, unsigned char *buf)
 416 {
 417         struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
 418         unsigned int blocksize;
 419         const char *label = 0;
 420
 421         blocksize = blkid_le16(rs->rs_blocksize);
 422
 423         /* If the superblock is inside the journal, we have the wrong one */
 424         if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
 425                 return -BLKID_ERR_BIG;
 426
 427         /* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
 428         if (id->bim_magic[6] == '2' || id->bim_magic[6] == '3') {
 429                 if (strlen(rs->rs_label))
 430                         label = rs->rs_label;
 431                 set_uuid(probe->dev, rs->rs_uuid, 0);
 432         }
 433         blkid_set_tag(probe->dev, "LABEL", label, sizeof(rs->rs_label));
 434
 435         return 0;
 436 }
 437
 438 static int probe_reiserfs4(struct blkid_probe *probe,
 439                            struct blkid_magic *id __BLKID_ATTR((unused)),
 440                            unsigned char *buf)
 441 {
 442         struct reiser4_super_block *rs4 = (struct reiser4_super_block *) buf;
 443         const unsigned char *label = 0;
 444
 445         if (strlen((char *) rs4->rs4_label))
 446                 label = rs4->rs4_label;
 447         set_uuid(probe->dev, rs4->rs4_uuid, 0);
 448         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 449                       sizeof(rs4->rs4_label));
 450
 451         return 0;
 452 }
 453
 454 static int probe_jfs(struct blkid_probe *probe,
 455                      struct blkid_magic *id __BLKID_ATTR((unused)),
 456                      unsigned char *buf)
 457 {
 458         struct jfs_super_block *js;
 459         const char *label = 0;
 460
 461         js = (struct jfs_super_block *)buf;
 462
 463         if (strlen((char *) js->js_label))
 464                 label = (char *) js->js_label;
 465         blkid_set_tag(probe->dev, "LABEL", label, sizeof(js->js_label));
 466         set_uuid(probe->dev, js->js_uuid, 0);
 467         return 0;
 468 }
 469
 470 static int probe_romfs(struct blkid_probe *probe,
 471                        struct blkid_magic *id __BLKID_ATTR((unused)),
 472                        unsigned char *buf)
 473 {
 474         struct romfs_super_block *ros;
 475         const char *label = 0;
 476
 477         ros = (struct romfs_super_block *)buf;
 478
 479         if (strlen((char *) ros->ros_volume))
 480                 label = (char *) ros->ros_volume;
 481         blkid_set_tag(probe->dev, "LABEL", label, 0);
 482         return 0;
 483 }
 484
 485 static int probe_cramfs(struct blkid_probe *probe,
 486                         struct blkid_magic *id __BLKID_ATTR((unused)),
 487                         unsigned char *buf)
 488 {
 489         struct cramfs_super_block *csb;
 490         const char *label = 0;
 491
 492         csb = (struct cramfs_super_block *)buf;
 493
 494         if (strlen((char *) csb->name))
 495                 label = (char *) csb->name;
 496         blkid_set_tag(probe->dev, "LABEL", label, 0);
 497         return 0;
 498 }
 499
 500 static int probe_swap0(struct blkid_probe *probe,
 501                        struct blkid_magic *id __BLKID_ATTR((unused)),
 502                        unsigned char *buf __BLKID_ATTR((unused)))
 503 {
 504         blkid_set_tag(probe->dev, "UUID", 0, 0);
 505         blkid_set_tag(probe->dev, "LABEL", 0, 0);
 506         return 0;
 507 }
 508
 509 static int probe_swap1(struct blkid_probe *probe,
 510                        struct blkid_magic *id __BLKID_ATTR((unused)),
 511                        unsigned char *buf __BLKID_ATTR((unused)))
 512 {
 513         struct swap_id_block *sws;
 514
 515         probe_swap0(probe, id, buf);
 516         /*
 517          * Version 1 swap headers are always located at offset of 1024
 518          * bytes, although the swap signature itself is located at the
 519          * end of the page (which may vary depending on hardware
 520          * pagesize).
 521          */
 522         sws = (struct swap_id_block *) get_buffer(probe, 1024, 1024);
 523         if (!sws)
 524                 return 1;
 525
 526         /* arbitrary sanity check.. is there any garbage down there? */
 527         if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0)  {
 528                 if (sws->sws_volume[0])
 529                         blkid_set_tag(probe->dev, "LABEL", sws->sws_volume,
 530                                       sizeof(sws->sws_volume));
 531                 if (sws->sws_uuid[0])
 532                         set_uuid(probe->dev, sws->sws_uuid, 0);
 533         }
 534         return 0;
 535 }
 536
 537 static int probe_iso9660(struct blkid_probe *probe,
 538                          struct blkid_magic *id __BLKID_ATTR((unused)),
 539                          unsigned char *buf)
 540 {
 541         struct iso_volume_descriptor *iso;
 542         const unsigned char *label;
 543
 544         iso = (struct iso_volume_descriptor *) buf;
 545         label = iso->volume_id;
 546
 547         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 548                       figure_label_len(label, 32));
 549         return 0;
 550 }
 551
 552
 553 static const char
 554 *udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
 555                  "NSR03", "TEA01", 0 };
 556
 557 static int probe_udf(struct blkid_probe *probe,
 558                      struct blkid_magic *id __BLKID_ATTR((unused)),
 559                      unsigned char *buf __BLKID_ATTR((unused)))
 560 {
 561         int j, bs;
 562         struct iso_volume_descriptor *isosb;
 563         const char ** m;
 564
 565         /* determine the block size by scanning in 2K increments
 566            (block sizes larger than 2K will be null padded) */
 567         for (bs = 1; bs < 16; bs++) {
 568                 isosb = (struct iso_volume_descriptor *)
 569                         get_buffer(probe, bs*2048+32768, sizeof(isosb));
 570                 if (!isosb)
 571                         return 1;
 572                 if (isosb->vd_id[0])
 573                         break;
 574         }
 575
 576         /* Scan up to another 64 blocks looking for additional VSD's */
 577         for (j = 1; j < 64; j++) {
 578                 if (j > 1) {
 579                         isosb = (struct iso_volume_descriptor *)
 580                                 get_buffer(probe, j*bs*2048+32768,
 581                                            sizeof(isosb));
 582                         if (!isosb)
 583                                 return 1;
 584                 }
 585                 /* If we find NSR0x then call it udf:
 586                    NSR01 for UDF 1.00
 587                    NSR02 for UDF 1.50
 588                    NSR03 for UDF 2.00 */
 589                 if (!memcmp(isosb->vd_id, "NSR0", 4))
 590                         return 0;
 591                 for (m = udf_magic; *m; m++)
 592                         if (!memcmp(*m, isosb->vd_id, 5))
 593                                 break;
 594                 if (*m == 0)
 595                         return 1;
 596         }
 597         return 1;
 598 }
 599
 600 static int probe_ocfs(struct blkid_probe *probe,
 601                       struct blkid_magic *id __BLKID_ATTR((unused)),
 602                       unsigned char *buf)
 603 {
 604         struct ocfs_volume_header ovh;
 605         struct ocfs_volume_label ovl;
 606         __u32 major;
 607
 608         memcpy(&ovh, buf, sizeof(ovh));
 609         memcpy(&ovl, buf+512, sizeof(ovl));
 610
 611         major = ocfsmajor(ovh);
 612         if (major == 1)
 613                 blkid_set_tag(probe->dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
 614         else if (major >= 9)
 615                 blkid_set_tag(probe->dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
 616
 617         blkid_set_tag(probe->dev, "LABEL", ovl.label, ocfslabellen(ovl));
 618         blkid_set_tag(probe->dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
 619         set_uuid(probe->dev, ovl.vol_id, 0);
 620         return 0;
 621 }
 622
 623 static int probe_ocfs2(struct blkid_probe *probe,
 624                        struct blkid_magic *id __BLKID_ATTR((unused)),
 625                        unsigned char *buf)
 626 {
 627         struct ocfs2_super_block *osb;
 628
 629         osb = (struct ocfs2_super_block *)buf;
 630
 631         blkid_set_tag(probe->dev, "LABEL", osb->s_label, sizeof(osb->s_label));
 632         set_uuid(probe->dev, osb->s_uuid, 0);
 633         return 0;
 634 }
 635
 636 static int probe_oracleasm(struct blkid_probe *probe,
 637                            struct blkid_magic *id __BLKID_ATTR((unused)),
 638                            unsigned char *buf)
 639 {
 640         struct oracle_asm_disk_label *dl;
 641
 642         dl = (struct oracle_asm_disk_label *)buf;
 643
 644         blkid_set_tag(probe->dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
 645         return 0;
 646 }
 647
 648 /*
 649  * BLKID_BLK_OFFS is at least as large as the highest bim_kboff defined
 650  * in the type_array table below + bim_kbalign.
 651  *
 652  * When probing for a lot of magics, we handle everything in 1kB buffers so
 653  * that we don't have to worry about reading each combination of block sizes.
 654  */
 655 #define BLKID_BLK_OFFS  64      /* currently reiserfs */
 656
 657 /*
 658  * Various filesystem magics that we can check for.  Note that kboff and
 659  * sboff are in kilobytes and bytes respectively.  All magics are in
 660  * byte strings so we don't worry about endian issues.
 661  */
 662 static struct blkid_magic type_array[] = {
 663 /*  type     kboff   sboff len  magic                   probe */
 664   { "oracleasm", 0,     32,  8, "ORCLDISK",             probe_oracleasm },
 665   { "ntfs",      0,      3,  8, "NTFS    ",             0 },
 666   { "jbd",       1,   0x38,  2, "\123\357",             probe_jbd },
 667   { "ext3",      1,   0x38,  2, "\123\357",             probe_ext3 },
 668   { "ext2",      1,   0x38,  2, "\123\357",             probe_ext2 },
 669   { "reiserfs",  8,   0x34,  8, "ReIsErFs",             probe_reiserfs },
 670   { "reiserfs", 64,   0x34,  9, "ReIsEr2Fs",            probe_reiserfs },
 671   { "reiserfs", 64,   0x34,  9, "ReIsEr3Fs",            probe_reiserfs },
 672   { "reiserfs", 64,   0x34,  8, "ReIsErFs",             probe_reiserfs },
 673   { "reiserfs",  8,     20,  8, "ReIsErFs",             probe_reiserfs },
 674   { "reiser4",  64,      0,  7, "ReIsEr4",              probe_reiserfs4 },
 675   { "vfat",      0,   0x52,  5, "MSWIN",                probe_fat },
 676   { "vfat",      0,   0x52,  8, "FAT32   ",             probe_fat },
 677   { "vfat",      0,   0x36,  5, "MSDOS",                probe_fat },
 678   { "vfat",      0,   0x36,  8, "FAT16   ",             probe_fat },
 679   { "vfat",      0,   0x36,  8, "FAT12   ",             probe_fat },
 680   { "vfat",      0,      0,  2, "\353\220",             probe_fat_nomagic },
 681   { "vfat",      0,      0,  1, "\351",                 probe_fat_nomagic },
 682   { "minix",     1,   0x10,  2, "\177\023",             0 },
 683   { "minix",     1,   0x10,  2, "\217\023",             0 },
 684   { "minix",     1,   0x10,  2, "\150\044",             0 },
 685   { "minix",     1,   0x10,  2, "\170\044",             0 },
 686   { "vxfs",      1,      0,  4, "\365\374\001\245",     0 },
 687   { "xfs",       0,      0,  4, "XFSB",                 probe_xfs },
 688   { "romfs",     0,      0,  8, "-rom1fs-",             probe_romfs },
 689   { "bfs",       0,      0,  4, "\316\372\173\033",     0 },
 690   { "cramfs",    0,      0,  4, "E=\315\050",           probe_cramfs },
 691   { "qnx4",      0,      4,  6, "QNX4FS",               0 },
 692   { "udf",      32,      1,  5, "BEA01",                probe_udf },
 693   { "udf",      32,      1,  5, "BOOT2",                probe_udf },
 694   { "udf",      32,      1,  5, "CD001",                probe_udf },
 695   { "udf",      32,      1,  5, "CDW02",                probe_udf },
 696   { "udf",      32,      1,  5, "NSR02",                probe_udf },
 697   { "udf",      32,      1,  5, "NSR03",                probe_udf },
 698   { "udf",      32,      1,  5, "TEA01",                probe_udf },
 699   { "iso9660",  32,      1,  5, "CD001",                probe_iso9660 },
 700   { "iso9660",  32,      9,  5, "CDROM",                probe_iso9660 },
 701   { "jfs",      32,      0,  4, "JFS1",                 probe_jfs },
 702   { "hfs",       1,      0,  2, "BD",                   0 },
 703   { "ufs",       8,  0x55c,  4, "T\031\001\000",        0 },
 704   { "hpfs",      8,      0,  4, "I\350\225\371",        0 },
 705   { "sysv",      0,  0x3f8,  4, "\020~\030\375",        0 },
 706   { "swap",      0,  0xff6, 10, "SWAP-SPACE",           probe_swap0 },
 707   { "swap",      0,  0xff6, 10, "SWAPSPACE2",           probe_swap1 },
 708   { "swsuspend", 0,  0xff6,  9, "S1SUSPEND",            probe_swap1 },
 709   { "swsuspend", 0,  0xff6,  9, "S2SUSPEND",            probe_swap1 },
 710   { "swap",      0, 0x1ff6, 10, "SWAP-SPACE",           probe_swap0 },
 711   { "swap",      0, 0x1ff6, 10, "SWAPSPACE2",           probe_swap1 },
 712   { "swsuspend", 0, 0x1ff6,  9, "S1SUSPEND",            probe_swap1 },
 713   { "swsuspend", 0, 0x1ff6,  9, "S2SUSPEND",            probe_swap1 },
 714   { "swap",      0, 0x3ff6, 10, "SWAP-SPACE",           probe_swap0 },
 715   { "swap",      0, 0x3ff6, 10, "SWAPSPACE2",           probe_swap1 },
 716   { "swsuspend", 0, 0x3ff6,  9, "S1SUSPEND",            probe_swap1 },
 717   { "swsuspend", 0, 0x3ff6,  9, "S2SUSPEND",            probe_swap1 },
 718   { "swap",      0, 0x7ff6, 10, "SWAP-SPACE",           probe_swap0 },
 719   { "swap",      0, 0x7ff6, 10, "SWAPSPACE2",           probe_swap1 },
 720   { "swsuspend", 0, 0x7ff6,  9, "S1SUSPEND",            probe_swap1 },
 721   { "swsuspend", 0, 0x7ff6,  9, "S2SUSPEND",            probe_swap1 },
 722   { "swap",      0, 0xfff6, 10, "SWAP-SPACE",           probe_swap0 },
 723   { "swap",      0, 0xfff6, 10, "SWAPSPACE2",           probe_swap1 },
 724   { "swsuspend", 0, 0xfff6,  9, "S1SUSPEND",            probe_swap1 },
 725   { "swsuspend", 0, 0xfff6,  9, "S2SUSPEND",            probe_swap1 },
 726   { "ocfs",      0,      8,  9, "OracleCFS",            probe_ocfs },
 727   { "ocfs2",     1,      0,  6, "OCFSV2",               probe_ocfs2 },
 728   { "ocfs2",     2,      0,  6, "OCFSV2",               probe_ocfs2 },
 729   { "ocfs2",     4,      0,  6, "OCFSV2",               probe_ocfs2 },
 730   { "ocfs2",     8,      0,  6, "OCFSV2",               probe_ocfs2 },
 731   {   NULL,      0,      0,  0, NULL,                   NULL }
 732 };
 733
 734 /*
 735  * Verify that the data in dev is consistent with what is on the actual
 736  * block device (using the devname field only).  Normally this will be
 737  * called when finding items in the cache, but for long running processes
 738  * is also desirable to revalidate an item before use.
 739  *
 740  * If we are unable to revalidate the data, we return the old data and
 741  * do not set the BLKID_BID_FL_VERIFIED flag on it.
 742  */
 743 blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
 744 {
 745         struct blkid_magic *id;
 746         struct blkid_probe probe;
 747         blkid_tag_iterate iter;
 748         unsigned char *buf;
 749         const char *type, *value;
 750         struct stat st;
 751         time_t diff, now;
 752         int idx;
 753
 754         if (!dev)
 755                 return NULL;
 756
 757         now = time(0);
 758         diff = now - dev->bid_time;
 759
 760         if ((now > dev->bid_time) && (diff > 0) &&
 761             ((diff < BLKID_PROBE_MIN) ||
 762              (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
 763               diff < BLKID_PROBE_INTERVAL)))
 764                 return dev;
 765
 766         DBG(DEBUG_PROBE,
 767             printf("need to revalidate %s (time since last check %lu)\n",
 768                    dev->bid_name, diff));
 769
 770         if (((probe.fd = open(dev->bid_name, O_RDONLY)) < 0) ||
 771             (fstat(probe.fd, &st) < 0)) {
 772                 if (probe.fd >= 0) close(probe.fd);
 773                 if (errno == ENXIO || errno == ENODEV || errno == ENOENT) {
 774                         blkid_free_dev(dev);
 775                         return NULL;
 776                 }
 777                 /* We don't have read permission, just return cache data. */
 778                 DBG(DEBUG_PROBE,
 779                     printf("returning unverified data for %s\n",
 780                            dev->bid_name));
 781                 return dev;
 782         }
 783
 784         probe.cache = cache;
 785         probe.dev = dev;
 786         probe.sbbuf = 0;
 787         probe.buf = 0;
 788         probe.buf_max = 0;
 789
 790         /*
 791          * Iterate over the type array.  If we already know the type,
 792          * then try that first.  If it doesn't work, then blow away
 793          * the type information, and try again.
 794          *
 795          */
 796 try_again:
 797         type = 0;
 798         if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
 799                 uuid_t  uuid;
 800
 801                 if (check_mdraid(probe.fd, uuid) == 0) {
 802                         set_uuid(dev, uuid, 0);
 803                         type = "mdraid";
 804                         goto found_type;
 805                 }
 806         }
 807         for (id = type_array; id->bim_type; id++) {
 808                 if (dev->bid_type &&
 809                     strcmp(id->bim_type, dev->bid_type))
 810                         continue;
 811
 812                 idx = id->bim_kboff + (id->bim_sboff >> 10);
 813                 buf = get_buffer(&probe, idx << 10, 1024);
 814                 if (!buf)
 815                         continue;
 816
 817                 if (memcmp(id->bim_magic, buf + (id->bim_sboff&0x3ff),
 818                            id->bim_len))
 819                         continue;
 820
 821                 if ((id->bim_probe == NULL) ||
 822                     (id->bim_probe(&probe, id, buf) == 0)) {
 823                         type = id->bim_type;
 824                         goto found_type;
 825                 }
 826         }
 827
 828         if (!id->bim_type && dev->bid_type) {
 829                 /*
 830                  * Zap the device filesystem information and try again
 831                  */
 832                 iter = blkid_tag_iterate_begin(dev);
 833                 while (blkid_tag_next(iter, &type, &value) == 0)
 834                         blkid_set_tag(dev, type, 0, 0);
 835                 blkid_tag_iterate_end(iter);
 836                 goto try_again;
 837         }
 838
 839         if (!dev->bid_type) {
 840                 if (probe.fd >= 0) close(probe.fd);
 841                 blkid_free_dev(dev);
 842                 return NULL;
 843         }
 844
 845 found_type:
 846         if (dev && type) {
 847                 dev->bid_devno = st.st_rdev;
 848                 dev->bid_time = time(0);
 849                 dev->bid_flags |= BLKID_BID_FL_VERIFIED;
 850                 cache->bic_flags |= BLKID_BIC_FL_CHANGED;
 851
 852                 blkid_set_tag(dev, "TYPE", type, 0);
 853
 854                 DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
 855                            dev->bid_name, st.st_rdev, type));
 856         }
 857
 858         if (probe.sbbuf)
 859                 free(probe.sbbuf);
 860         if (probe.buf)
 861                 free(probe.buf);
 862         close(probe.fd);
 863
 864         return dev;
 865 }
 866
 867 int blkid_known_fstype(const char *fstype)
 868 {
 869         struct blkid_magic *id;
 870
 871         for (id = type_array; id->bim_type; id++) {
 872                 if (strcmp(fstype, id->bim_type) == 0)
 873                         return 1;
 874         }
 875         return 0;
 876 }
 877
 878 #ifdef TEST_PROGRAM
 879 int main(int argc, char **argv)
 880 {
 881         blkid_dev dev;
 882         blkid_cache cache;
 883         int ret;
 884
 885         if (argc != 2) {
 886                 fprintf(stderr, "Usage: %s device\n"
 887                         "Probe a single device to determine type\n", argv[0]);
 888                 exit(1);
 889         }
 890         if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
 891                 fprintf(stderr, "%s: error creating cache (%d)\n",
 892                         argv[0], ret);
 893                 exit(1);
 894         }
 895         dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
 896         if (!dev) {
 897                 printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
 898                 return (1);
 899         }
 900         printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");
 901         if (dev->bid_label)
 902                 printf("LABEL='%s'\n", dev->bid_label);
 903         if (dev->bid_uuid)
 904                 printf("UUID='%s'\n", dev->bid_uuid);
 905
 906         blkid_free_dev(dev);
 907         return (0);
 908 }
 909 #endif