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