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                           blkid_loff_t 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 (blkid_llseek(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) && memcmp("\374N+\251", 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 + 4, &md->set_uuid1, 12);
 120         }
 121         return 0;
 122 }
 123
 124 static void set_uuid(blkid_dev dev, uuid_t uuid, const 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 const char *no_name = "NO NAME    ";
 224
 225 static unsigned char *search_fat_label(struct vfat_dir_entry *dir, int count)
 226 {
 227         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, *tmp;
 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         tmp = (unsigned char *)&ms->ms_sector_size;
 265         sector_size = tmp[0] + (tmp[1] << 8);
 266         if (sector_size != 0x200 && sector_size != 0x400 &&
 267             sector_size != 0x800 && sector_size != 0x1000)
 268                 return 1;
 269
 270         tmp = (unsigned char *)&ms->ms_dir_entries;
 271         dir_entries = tmp[0] + (tmp[1] << 8);
 272         reserved =  blkid_le16(ms->ms_reserved);
 273         tmp = (unsigned char *)&ms->ms_sectors;
 274         sect_count = tmp[0] + (tmp[1] << 8);
 275         if (sect_count == 0)
 276                 sect_count = blkid_le32(ms->ms_total_sect);
 277
 278         fat_length = blkid_le16(ms->ms_fat_length);
 279         if (fat_length == 0)
 280                 fat_length = blkid_le32(vs->vs_fat32_length);
 281
 282         fat_size = fat_length * ms->ms_fats;
 283         dir_size = ((dir_entries * sizeof(struct vfat_dir_entry)) +
 284                         (sector_size-1)) / sector_size;
 285
 286         cluster_count = sect_count - (reserved + fat_size + dir_size);
 287         if (ms->ms_cluster_size == 0)
 288                 return 1;
 289         cluster_count /= ms->ms_cluster_size;
 290
 291         if (cluster_count > FAT32_MAX)
 292                 return 1;
 293
 294         if (ms->ms_fat_length) {
 295                 /* the label may be an attribute in the root directory */
 296                 root_start = (reserved + fat_size) * sector_size;
 297                 root_dir_entries = vs->vs_dir_entries[0] +
 298                         (vs->vs_dir_entries[1] << 8);
 299
 300                 buf_size = root_dir_entries * sizeof(struct vfat_dir_entry);
 301                 dir = (struct vfat_dir_entry *) get_buffer(probe, root_start,
 302                                                            buf_size);
 303                 if (dir)
 304                         vol_label = search_fat_label(dir, root_dir_entries);
 305
 306                 if (!vol_label || !memcmp(vol_label, no_name, 11))
 307                         vol_label = ms->ms_label;
 308                 vol_serno = ms->ms_serno;
 309
 310                 blkid_set_tag(probe->dev, "SEC_TYPE", "msdos",
 311                               sizeof("msdos"));
 312         } else {
 313                 /* Search the FAT32 root dir for the label attribute */
 314                 buf_size = vs->vs_cluster_size * sector_size;
 315                 start_data_sect = reserved + fat_size;
 316
 317                 next = blkid_le32(vs->vs_root_cluster);
 318                 while (next && --maxloop) {
 319                         __u32 next_sect_off;
 320                         __u64 next_off, fat_entry_off;
 321                         int count;
 322
 323                         next_sect_off = (next - 2) * vs->vs_cluster_size;
 324                         next_off = (start_data_sect + next_sect_off) *
 325                                 sector_size;
 326
 327                         dir = (struct vfat_dir_entry *)
 328                                 get_buffer(probe, next_off, buf_size);
 329                         if (dir == NULL)
 330                                 break;
 331
 332                         count = buf_size / sizeof(struct vfat_dir_entry);
 333
 334                         vol_label = search_fat_label(dir, count);
 335                         if (vol_label)
 336                                 break;
 337
 338                         /* get FAT entry */
 339                         fat_entry_off = (reserved * sector_size) +
 340                                 (next * sizeof(__u32));
 341                         buf = get_buffer(probe, fat_entry_off, buf_size);
 342                         if (buf == NULL)
 343                                 break;
 344
 345                         /* set next cluster */
 346                         next = blkid_le32(*((__u32 *) buf) & 0x0fffffff);
 347                 }
 348
 349                 if (!vol_label || !memcmp(vol_label, no_name, 11))
 350                         vol_label = vs->vs_label;
 351                 vol_serno = vs->vs_serno;
 352         }
 353
 354         if (vol_label && memcmp(vol_label, no_name, 11)) {
 355                 if ((label_len = figure_label_len(vol_label, 11)))
 356                         label = vol_label;
 357         }
 358
 359         /* We can't just print them as %04X, because they are unaligned */
 360         sprintf(serno, "%02X%02X-%02X%02X", vol_serno[3], vol_serno[2],
 361                 vol_serno[1], vol_serno[0]);
 362
 363         blkid_set_tag(probe->dev, "LABEL", (const char *) label, label_len);
 364         blkid_set_tag(probe->dev, "UUID", serno, sizeof(serno)-1);
 365
 366         return 0;
 367 }
 368
 369 /*
 370  * The FAT filesystem could be without a magic string in superblock
 371  * (e.g. old floppies).  This heuristic for FAT detection is inspired
 372  * by http://vrfy.org/projects/volume_id/ and Linux kernel.
 373  * [7-Jul-2005, Karel Zak <kzak@redhat.com>]
 374  */
 375 static int probe_fat_nomagic(struct blkid_probe *probe,
 376                              struct blkid_magic *id __BLKID_ATTR((unused)),
 377                              unsigned char *buf)
 378 {
 379         struct vfat_super_block *vs;
 380
 381         vs = (struct vfat_super_block *)buf;
 382
 383         /* heads check */
 384         if (vs->vs_heads == 0)
 385                 return 1;
 386
 387         /* cluster size check*/
 388         if (vs->vs_cluster_size == 0 ||
 389             (vs->vs_cluster_size & (vs->vs_cluster_size-1)))
 390                 return 1;
 391
 392         /* media check */
 393         if (vs->vs_media < 0xf8 && vs->vs_media != 0xf0)
 394                 return 1;
 395
 396         /* fat counts(Linux kernel expects at least 1 FAT table) */
 397         if (!vs->vs_fats)
 398                 return 1;
 399
 400         return probe_fat(probe, id, buf);
 401 }
 402
 403 static int probe_ntfs(struct blkid_probe *probe,
 404                       struct blkid_magic *id __BLKID_ATTR((unused)),
 405                       unsigned char *buf)
 406 {
 407         struct ntfs_super_block *ns;
 408         struct master_file_table_record *mft;
 409         struct file_attribute *attr;
 410         char            uuid_str[17], label_str[129], *cp;
 411         int             bytes_per_sector, sectors_per_cluster;
 412         int             mft_record_size, attr_off, attr_len;
 413         unsigned int    i, attr_type, val_len;
 414         int             val_off;
 415         __u64           nr_clusters;
 416         blkid_loff_t off;
 417         unsigned char *buf_mft, *val;
 418
 419         ns = (struct ntfs_super_block *) buf;
 420
 421         bytes_per_sector = ns->bios_parameter_block[0] +
 422                 (ns->bios_parameter_block[1]  << 8);
 423         sectors_per_cluster = ns->bios_parameter_block[2];
 424
 425         if ((bytes_per_sector < 512) || (sectors_per_cluster == 0))
 426                 return 1;
 427
 428         if (ns->cluster_per_mft_record < 0)
 429                 mft_record_size = 1 << (0-ns->cluster_per_mft_record);
 430         else
 431                 mft_record_size = ns->cluster_per_mft_record *
 432                         sectors_per_cluster * bytes_per_sector;
 433         nr_clusters = blkid_le64(ns->number_of_sectors) / sectors_per_cluster;
 434
 435         if ((blkid_le64(ns->mft_cluster_location) > nr_clusters) ||
 436             (blkid_le64(ns->mft_mirror_cluster_location) > nr_clusters))
 437                 return 1;
 438
 439         off = blkid_le64(ns->mft_mirror_cluster_location) *
 440                 bytes_per_sector * sectors_per_cluster;
 441
 442         buf_mft = get_buffer(probe, off, mft_record_size);
 443         if (!buf_mft)
 444                 return 1;
 445
 446         if (memcmp(buf_mft, "FILE", 4))
 447                 return 1;
 448
 449         off = blkid_le64(ns->mft_cluster_location) * bytes_per_sector *
 450                 sectors_per_cluster;
 451
 452         buf_mft = get_buffer(probe, off, mft_record_size);
 453         if (!buf_mft)
 454                 return 1;
 455
 456         if (memcmp(buf_mft, "FILE", 4))
 457                 return 1;
 458
 459         off += MFT_RECORD_VOLUME * mft_record_size;
 460
 461         buf_mft = get_buffer(probe, off, mft_record_size);
 462         if (!buf_mft)
 463                 return 1;
 464
 465         if (memcmp(buf_mft, "FILE", 4))
 466                 return 1;
 467
 468         mft = (struct master_file_table_record *) buf_mft;
 469
 470         attr_off = blkid_le16(mft->attrs_offset);
 471         label_str[0] = 0;
 472
 473         while (1) {
 474                 attr = (struct file_attribute *) (buf_mft + attr_off);
 475                 attr_len = blkid_le16(attr->len);
 476                 attr_type = blkid_le32(attr->type);
 477                 val_off = blkid_le16(attr->value_offset);
 478                 val_len = blkid_le32(attr->value_len);
 479
 480                 attr_off += attr_len;
 481
 482                 if ((attr_off > mft_record_size) ||
 483                     (attr_len == 0))
 484                         break;
 485
 486                 if (attr_type == MFT_RECORD_ATTR_END)
 487                         break;
 488
 489                 if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
 490                         if (val_len > sizeof(label_str))
 491                                 val_len = sizeof(label_str)-1;
 492
 493                         for (i=0, cp=label_str; i < val_len; i+=2,cp++) {
 494                                 val = ((__u8 *) attr) + val_off + i;
 495                                 *cp = val[0];
 496                                 if (val[1])
 497                                         *cp = '?';
 498                         }
 499                         *cp = 0;
 500                 }
 501         }
 502
 503         sprintf(uuid_str, "%llX", blkid_le64(ns->volume_serial));
 504         blkid_set_tag(probe->dev, "UUID", uuid_str, 0);
 505         if (label_str[0])
 506                 blkid_set_tag(probe->dev, "LABEL", label_str, 0);
 507         return 0;
 508 }
 509
 510
 511 static int probe_xfs(struct blkid_probe *probe,
 512                      struct blkid_magic *id __BLKID_ATTR((unused)),
 513                      unsigned char *buf)
 514 {
 515         struct xfs_super_block *xs;
 516         const char *label = 0;
 517
 518         xs = (struct xfs_super_block *)buf;
 519
 520         if (strlen(xs->xs_fname))
 521                 label = xs->xs_fname;
 522         blkid_set_tag(probe->dev, "LABEL", label, sizeof(xs->xs_fname));
 523         set_uuid(probe->dev, xs->xs_uuid, 0);
 524         return 0;
 525 }
 526
 527 static int probe_reiserfs(struct blkid_probe *probe,
 528                           struct blkid_magic *id, unsigned char *buf)
 529 {
 530         struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
 531         unsigned int blocksize;
 532         const char *label = 0;
 533
 534         blocksize = blkid_le16(rs->rs_blocksize);
 535
 536         /* If the superblock is inside the journal, we have the wrong one */
 537         if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
 538                 return -BLKID_ERR_BIG;
 539
 540         /* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
 541         if (id->bim_magic[6] == '2' || id->bim_magic[6] == '3') {
 542                 if (strlen(rs->rs_label))
 543                         label = rs->rs_label;
 544                 set_uuid(probe->dev, rs->rs_uuid, 0);
 545         }
 546         blkid_set_tag(probe->dev, "LABEL", label, sizeof(rs->rs_label));
 547
 548         return 0;
 549 }
 550
 551 static int probe_reiserfs4(struct blkid_probe *probe,
 552                            struct blkid_magic *id __BLKID_ATTR((unused)),
 553                            unsigned char *buf)
 554 {
 555         struct reiser4_super_block *rs4 = (struct reiser4_super_block *) buf;
 556         const unsigned char *label = 0;
 557
 558         if (strlen((char *) rs4->rs4_label))
 559                 label = rs4->rs4_label;
 560         set_uuid(probe->dev, rs4->rs4_uuid, 0);
 561         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 562                       sizeof(rs4->rs4_label));
 563
 564         return 0;
 565 }
 566
 567 static int probe_jfs(struct blkid_probe *probe,
 568                      struct blkid_magic *id __BLKID_ATTR((unused)),
 569                      unsigned char *buf)
 570 {
 571         struct jfs_super_block *js;
 572         const char *label = 0;
 573
 574         js = (struct jfs_super_block *)buf;
 575
 576         if (strlen((char *) js->js_label))
 577                 label = (char *) js->js_label;
 578         blkid_set_tag(probe->dev, "LABEL", label, sizeof(js->js_label));
 579         set_uuid(probe->dev, js->js_uuid, 0);
 580         return 0;
 581 }
 582
 583 static int probe_luks(struct blkid_probe *probe,
 584                        struct blkid_magic *id __BLKID_ATTR((unused)),
 585                        unsigned char *buf)
 586 {
 587         char uuid[40];
 588
 589         /* 168 is the offset to the 40 character uuid:
 590          * http://luks.endorphin.org/LUKS-on-disk-format.pdf */
 591         strncpy(uuid, (char *) buf+168, 40);
 592         blkid_set_tag(probe->dev, "UUID", uuid, sizeof(uuid));
 593         return 0;
 594 }
 595
 596 static int probe_romfs(struct blkid_probe *probe,
 597                        struct blkid_magic *id __BLKID_ATTR((unused)),
 598                        unsigned char *buf)
 599 {
 600         struct romfs_super_block *ros;
 601         const char *label = 0;
 602
 603         ros = (struct romfs_super_block *)buf;
 604
 605         if (strlen((char *) ros->ros_volume))
 606                 label = (char *) ros->ros_volume;
 607         blkid_set_tag(probe->dev, "LABEL", label, 0);
 608         return 0;
 609 }
 610
 611 static int probe_cramfs(struct blkid_probe *probe,
 612                         struct blkid_magic *id __BLKID_ATTR((unused)),
 613                         unsigned char *buf)
 614 {
 615         struct cramfs_super_block *csb;
 616         const char *label = 0;
 617
 618         csb = (struct cramfs_super_block *)buf;
 619
 620         if (strlen((char *) csb->name))
 621                 label = (char *) csb->name;
 622         blkid_set_tag(probe->dev, "LABEL", label, 0);
 623         return 0;
 624 }
 625
 626 static int probe_swap0(struct blkid_probe *probe,
 627                        struct blkid_magic *id __BLKID_ATTR((unused)),
 628                        unsigned char *buf __BLKID_ATTR((unused)))
 629 {
 630         blkid_set_tag(probe->dev, "UUID", 0, 0);
 631         blkid_set_tag(probe->dev, "LABEL", 0, 0);
 632         return 0;
 633 }
 634
 635 static int probe_swap1(struct blkid_probe *probe,
 636                        struct blkid_magic *id __BLKID_ATTR((unused)),
 637                        unsigned char *buf __BLKID_ATTR((unused)))
 638 {
 639         struct swap_id_block *sws;
 640
 641         probe_swap0(probe, id, buf);
 642         /*
 643          * Version 1 swap headers are always located at offset of 1024
 644          * bytes, although the swap signature itself is located at the
 645          * end of the page (which may vary depending on hardware
 646          * pagesize).
 647          */
 648         sws = (struct swap_id_block *) get_buffer(probe, 1024, 1024);
 649         if (!sws)
 650                 return 1;
 651
 652         /* arbitrary sanity check.. is there any garbage down there? */
 653         if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0)  {
 654                 if (sws->sws_volume[0])
 655                         blkid_set_tag(probe->dev, "LABEL", sws->sws_volume,
 656                                       sizeof(sws->sws_volume));
 657                 if (sws->sws_uuid[0])
 658                         set_uuid(probe->dev, sws->sws_uuid, 0);
 659         }
 660         return 0;
 661 }
 662
 663 static int probe_iso9660(struct blkid_probe *probe,
 664                          struct blkid_magic *id __BLKID_ATTR((unused)),
 665                          unsigned char *buf)
 666 {
 667         struct iso_volume_descriptor *iso;
 668         const unsigned char *label;
 669
 670         iso = (struct iso_volume_descriptor *) buf;
 671         label = iso->volume_id;
 672
 673         blkid_set_tag(probe->dev, "LABEL", (const char *) label,
 674                       figure_label_len(label, 32));
 675         return 0;
 676 }
 677
 678
 679 static const char
 680 *udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
 681                  "NSR03", "TEA01", 0 };
 682
 683 static int probe_udf(struct blkid_probe *probe,
 684                      struct blkid_magic *id __BLKID_ATTR((unused)),
 685                      unsigned char *buf __BLKID_ATTR((unused)))
 686 {
 687         int j, bs;
 688         struct iso_volume_descriptor *isosb;
 689         const char ** m;
 690
 691         /* determine the block size by scanning in 2K increments
 692            (block sizes larger than 2K will be null padded) */
 693         for (bs = 1; bs < 16; bs++) {
 694                 isosb = (struct iso_volume_descriptor *)
 695                         get_buffer(probe, bs*2048+32768, sizeof(isosb));
 696                 if (!isosb)
 697                         return 1;
 698                 if (isosb->vd_id[0])
 699                         break;
 700         }
 701
 702         /* Scan up to another 64 blocks looking for additional VSD's */
 703         for (j = 1; j < 64; j++) {
 704                 if (j > 1) {
 705                         isosb = (struct iso_volume_descriptor *)
 706                                 get_buffer(probe, j*bs*2048+32768,
 707                                            sizeof(isosb));
 708                         if (!isosb)
 709                                 return 1;
 710                 }
 711                 /* If we find NSR0x then call it udf:
 712                    NSR01 for UDF 1.00
 713                    NSR02 for UDF 1.50
 714                    NSR03 for UDF 2.00 */
 715                 if (!memcmp(isosb->vd_id, "NSR0", 4))
 716                         return 0;
 717                 for (m = udf_magic; *m; m++)
 718                         if (!memcmp(*m, isosb->vd_id, 5))
 719                                 break;
 720                 if (*m == 0)
 721                         return 1;
 722         }
 723         return 1;
 724 }
 725
 726 static int probe_ocfs(struct blkid_probe *probe,
 727                       struct blkid_magic *id __BLKID_ATTR((unused)),
 728                       unsigned char *buf)
 729 {
 730         struct ocfs_volume_header ovh;
 731         struct ocfs_volume_label ovl;
 732         __u32 major;
 733
 734         memcpy(&ovh, buf, sizeof(ovh));
 735         memcpy(&ovl, buf+512, sizeof(ovl));
 736
 737         major = ocfsmajor(ovh);
 738         if (major == 1)
 739                 blkid_set_tag(probe->dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
 740         else if (major >= 9)
 741                 blkid_set_tag(probe->dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
 742
 743         blkid_set_tag(probe->dev, "LABEL", ovl.label, ocfslabellen(ovl));
 744         blkid_set_tag(probe->dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
 745         set_uuid(probe->dev, ovl.vol_id, 0);
 746         return 0;
 747 }
 748
 749 static int probe_ocfs2(struct blkid_probe *probe,
 750                        struct blkid_magic *id __BLKID_ATTR((unused)),
 751                        unsigned char *buf)
 752 {
 753         struct ocfs2_super_block *osb;
 754
 755         osb = (struct ocfs2_super_block *)buf;
 756
 757         blkid_set_tag(probe->dev, "LABEL", osb->s_label, sizeof(osb->s_label));
 758         set_uuid(probe->dev, osb->s_uuid, 0);
 759         return 0;
 760 }
 761
 762 static int probe_oracleasm(struct blkid_probe *probe,
 763                            struct blkid_magic *id __BLKID_ATTR((unused)),
 764                            unsigned char *buf)
 765 {
 766         struct oracle_asm_disk_label *dl;
 767
 768         dl = (struct oracle_asm_disk_label *)buf;
 769
 770         blkid_set_tag(probe->dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
 771         return 0;
 772 }
 773
 774 static int probe_gfs(struct blkid_probe *probe,
 775                      struct blkid_magic *id __BLKID_ATTR((unused)),
 776                      unsigned char *buf)
 777 {
 778         struct gfs2_sb *sbd;
 779         const char *label = 0;
 780
 781         sbd = (struct gfs2_sb *)buf;
 782
 783         if (blkid_be32(sbd->sb_fs_format) == GFS_FORMAT_FS &&
 784             blkid_be32(sbd->sb_multihost_format) == GFS_FORMAT_MULTI)
 785         {
 786                 blkid_set_tag(probe->dev, "UUID", 0, 0);
 787
 788                 if (strlen(sbd->sb_locktable))
 789                         label = sbd->sb_locktable;
 790                 blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
 791                 return 0;
 792         }
 793         return 1;
 794 }
 795
 796 static int probe_gfs2(struct blkid_probe *probe,
 797                      struct blkid_magic *id __BLKID_ATTR((unused)),
 798                      unsigned char *buf)
 799 {
 800         struct gfs2_sb *sbd;
 801         const char *label = 0;
 802
 803         sbd = (struct gfs2_sb *)buf;
 804
 805         if (blkid_be32(sbd->sb_fs_format) == GFS2_FORMAT_FS &&
 806             blkid_be32(sbd->sb_multihost_format) == GFS2_FORMAT_MULTI)
 807         {
 808                 blkid_set_tag(probe->dev, "UUID", 0, 0);
 809
 810                 if (strlen(sbd->sb_locktable))
 811                         label = sbd->sb_locktable;
 812                 blkid_set_tag(probe->dev, "LABEL", label, sizeof(sbd->sb_locktable));
 813                 return 0;
 814         }
 815         return 1;
 816 }
 817
 818 /*
 819  * BLKID_BLK_OFFS is at least as large as the highest bim_kboff defined
 820  * in the type_array table below + bim_kbalign.
 821  *
 822  * When probing for a lot of magics, we handle everything in 1kB buffers so
 823  * that we don't have to worry about reading each combination of block sizes.
 824  */
 825 #define BLKID_BLK_OFFS  64      /* currently reiserfs */
 826
 827 /*
 828  * Various filesystem magics that we can check for.  Note that kboff and
 829  * sboff are in kilobytes and bytes respectively.  All magics are in
 830  * byte strings so we don't worry about endian issues.
 831  */
 832 static struct blkid_magic type_array[] = {
 833 /*  type     kboff   sboff len  magic                   probe */
 834   { "oracleasm", 0,     32,  8, "ORCLDISK",             probe_oracleasm },
 835   { "ntfs",      0,      3,  8, "NTFS    ",             probe_ntfs },
 836   { "jbd",       1,   0x38,  2, "\123\357",             probe_jbd },
 837   { "ext3",      1,   0x38,  2, "\123\357",             probe_ext3 },
 838   { "ext2",      1,   0x38,  2, "\123\357",             probe_ext2 },
 839   { "reiserfs",  8,   0x34,  8, "ReIsErFs",             probe_reiserfs },
 840   { "reiserfs", 64,   0x34,  9, "ReIsEr2Fs",            probe_reiserfs },
 841   { "reiserfs", 64,   0x34,  9, "ReIsEr3Fs",            probe_reiserfs },
 842   { "reiserfs", 64,   0x34,  8, "ReIsErFs",             probe_reiserfs },
 843   { "reiserfs",  8,     20,  8, "ReIsErFs",             probe_reiserfs },
 844   { "reiser4",  64,      0,  7, "ReIsEr4",              probe_reiserfs4 },
 845   { "gfs2",     64,      0,  4, "\x01\x16\x19\x70",     probe_gfs2 },
 846   { "gfs",      64,      0,  4, "\x01\x16\x19\x70",     probe_gfs },
 847   { "vfat",      0,   0x52,  5, "MSWIN",                probe_fat },
 848   { "vfat",      0,   0x52,  8, "FAT32   ",             probe_fat },
 849   { "vfat",      0,   0x36,  5, "MSDOS",                probe_fat },
 850   { "vfat",      0,   0x36,  8, "FAT16   ",             probe_fat },
 851   { "vfat",      0,   0x36,  8, "FAT12   ",             probe_fat },
 852   { "vfat",      0,      0,  1, "\353",                 probe_fat_nomagic },
 853   { "vfat",      0,      0,  1, "\351",                 probe_fat_nomagic },
 854   { "vfat",      0,  0x1fe,  2, "\125\252",             probe_fat_nomagic },
 855   { "minix",     1,   0x10,  2, "\177\023",             0 },
 856   { "minix",     1,   0x10,  2, "\217\023",             0 },
 857   { "minix",     1,   0x10,  2, "\150\044",             0 },
 858   { "minix",     1,   0x10,  2, "\170\044",             0 },
 859   { "vxfs",      1,      0,  4, "\365\374\001\245",     0 },
 860   { "xfs",       0,      0,  4, "XFSB",                 probe_xfs },
 861   { "romfs",     0,      0,  8, "-rom1fs-",             probe_romfs },
 862   { "bfs",       0,      0,  4, "\316\372\173\033",     0 },
 863   { "cramfs",    0,      0,  4, "E=\315\050",           probe_cramfs },
 864   { "qnx4",      0,      4,  6, "QNX4FS",               0 },
 865   { "udf",      32,      1,  5, "BEA01",                probe_udf },
 866   { "udf",      32,      1,  5, "BOOT2",                probe_udf },
 867   { "udf",      32,      1,  5, "CD001",                probe_udf },
 868   { "udf",      32,      1,  5, "CDW02",                probe_udf },
 869   { "udf",      32,      1,  5, "NSR02",                probe_udf },
 870   { "udf",      32,      1,  5, "NSR03",                probe_udf },
 871   { "udf",      32,      1,  5, "TEA01",                probe_udf },
 872   { "iso9660",  32,      1,  5, "CD001",                probe_iso9660 },
 873   { "iso9660",  32,      9,  5, "CDROM",                probe_iso9660 },
 874   { "jfs",      32,      0,  4, "JFS1",                 probe_jfs },
 875   { "hfs",       1,      0,  2, "BD",                   0 },
 876   { "ufs",       8,  0x55c,  4, "T\031\001\000",        0 },
 877   { "hpfs",      8,      0,  4, "I\350\225\371",        0 },
 878   { "sysv",      0,  0x3f8,  4, "\020~\030\375",        0 },
 879   { "swap",      0,  0xff6, 10, "SWAP-SPACE",           probe_swap0 },
 880   { "swap",      0,  0xff6, 10, "SWAPSPACE2",           probe_swap1 },
 881   { "swsuspend", 0,  0xff6,  9, "S1SUSPEND",            probe_swap1 },
 882   { "swsuspend", 0,  0xff6,  9, "S2SUSPEND",            probe_swap1 },
 883   { "swap",      0, 0x1ff6, 10, "SWAP-SPACE",           probe_swap0 },
 884   { "swap",      0, 0x1ff6, 10, "SWAPSPACE2",           probe_swap1 },
 885   { "swsuspend", 0, 0x1ff6,  9, "S1SUSPEND",            probe_swap1 },
 886   { "swsuspend", 0, 0x1ff6,  9, "S2SUSPEND",            probe_swap1 },
 887   { "swap",      0, 0x3ff6, 10, "SWAP-SPACE",           probe_swap0 },
 888   { "swap",      0, 0x3ff6, 10, "SWAPSPACE2",           probe_swap1 },
 889   { "swsuspend", 0, 0x3ff6,  9, "S1SUSPEND",            probe_swap1 },
 890   { "swsuspend", 0, 0x3ff6,  9, "S2SUSPEND",            probe_swap1 },
 891   { "swap",      0, 0x7ff6, 10, "SWAP-SPACE",           probe_swap0 },
 892   { "swap",      0, 0x7ff6, 10, "SWAPSPACE2",           probe_swap1 },
 893   { "swsuspend", 0, 0x7ff6,  9, "S1SUSPEND",            probe_swap1 },
 894   { "swsuspend", 0, 0x7ff6,  9, "S2SUSPEND",            probe_swap1 },
 895   { "swap",      0, 0xfff6, 10, "SWAP-SPACE",           probe_swap0 },
 896   { "swap",      0, 0xfff6, 10, "SWAPSPACE2",           probe_swap1 },
 897   { "swsuspend", 0, 0xfff6,  9, "S1SUSPEND",            probe_swap1 },
 898   { "swsuspend", 0, 0xfff6,  9, "S2SUSPEND",            probe_swap1 },
 899   { "ocfs",      0,      8,  9, "OracleCFS",            probe_ocfs },
 900   { "ocfs2",     1,      0,  6, "OCFSV2",               probe_ocfs2 },
 901   { "ocfs2",     2,      0,  6, "OCFSV2",               probe_ocfs2 },
 902   { "ocfs2",     4,      0,  6, "OCFSV2",               probe_ocfs2 },
 903   { "ocfs2",     8,      0,  6, "OCFSV2",               probe_ocfs2 },
 904   { "crypt_LUKS", 0,     0,  6, "LUKS\xba\xbe",         probe_luks },
 905   { "squashfs",  0,      0,  4, "sqsh",                 0 },
 906   { "squashfs",  0,      0,  4, "hsqs",                 0 },
 907   {   NULL,      0,      0,  0, NULL,                   NULL }
 908 };
 909
 910 /*
 911  * Verify that the data in dev is consistent with what is on the actual
 912  * block device (using the devname field only).  Normally this will be
 913  * called when finding items in the cache, but for long running processes
 914  * is also desirable to revalidate an item before use.
 915  *
 916  * If we are unable to revalidate the data, we return the old data and
 917  * do not set the BLKID_BID_FL_VERIFIED flag on it.
 918  */
 919 blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
 920 {
 921         struct blkid_magic *id;
 922         struct blkid_probe probe;
 923         blkid_tag_iterate iter;
 924         unsigned char *buf;
 925         const char *type, *value;
 926         struct stat st;
 927         time_t diff, now;
 928         int idx;
 929
 930         if (!dev)
 931                 return NULL;
 932
 933         now = time(0);
 934         diff = now - dev->bid_time;
 935
 936         if ((now > dev->bid_time) && (diff > 0) &&
 937             ((diff < BLKID_PROBE_MIN) ||
 938              (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
 939               diff < BLKID_PROBE_INTERVAL)))
 940                 return dev;
 941
 942         DBG(DEBUG_PROBE,
 943             printf("need to revalidate %s (time since last check %llu)\n",
 944                    dev->bid_name, (unsigned long long)diff));
 945
 946         if (((probe.fd = open(dev->bid_name, O_RDONLY)) < 0) ||
 947             (fstat(probe.fd, &st) < 0)) {
 948                 if (probe.fd >= 0) close(probe.fd);
 949                 if (errno == ENXIO || errno == ENODEV || errno == ENOENT) {
 950                         blkid_free_dev(dev);
 951                         return NULL;
 952                 }
 953                 /* We don't have read permission, just return cache data. */
 954                 DBG(DEBUG_PROBE,
 955                     printf("returning unverified data for %s\n",
 956                            dev->bid_name));
 957                 return dev;
 958         }
 959
 960         probe.cache = cache;
 961         probe.dev = dev;
 962         probe.sbbuf = 0;
 963         probe.buf = 0;
 964         probe.buf_max = 0;
 965
 966         /*
 967          * Iterate over the type array.  If we already know the type,
 968          * then try that first.  If it doesn't work, then blow away
 969          * the type information, and try again.
 970          *
 971          */
 972 try_again:
 973         type = 0;
 974         if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
 975                 uuid_t  uuid;
 976
 977                 if (check_mdraid(probe.fd, uuid) == 0) {
 978                         set_uuid(dev, uuid, 0);
 979                         type = "mdraid";
 980                         goto found_type;
 981                 }
 982         }
 983         for (id = type_array; id->bim_type; id++) {
 984                 if (dev->bid_type &&
 985                     strcmp(id->bim_type, dev->bid_type))
 986                         continue;
 987
 988                 idx = id->bim_kboff + (id->bim_sboff >> 10);
 989                 buf = get_buffer(&probe, idx << 10, 1024);
 990                 if (!buf)
 991                         continue;
 992
 993                 if (memcmp(id->bim_magic, buf + (id->bim_sboff&0x3ff),
 994                            id->bim_len))
 995                         continue;
 996
 997                 if ((id->bim_probe == NULL) ||
 998                     (id->bim_probe(&probe, id, buf) == 0)) {
 999                         type = id->bim_type;
1000                         goto found_type;
1001                 }
1002         }
1003
1004         if (!id->bim_type && dev->bid_type) {
1005                 /*
1006                  * Zap the device filesystem information and try again
1007                  */
1008                 DBG(DEBUG_PROBE,
1009                     printf("previous fs type %s not valid, "
1010                            "trying full probe\n", dev->bid_type));
1011                 iter = blkid_tag_iterate_begin(dev);
1012                 while (blkid_tag_next(iter, &type, &value) == 0)
1013                         blkid_set_tag(dev, type, 0, 0);
1014                 blkid_tag_iterate_end(iter);
1015                 goto try_again;
1016         }
1017
1018         if (!dev->bid_type) {
1019                 blkid_free_dev(dev);
1020                 dev = 0;
1021                 goto found_type;
1022         }
1023
1024 found_type:
1025         if (dev && type) {
1026                 dev->bid_devno = st.st_rdev;
1027                 dev->bid_time = time(0);
1028                 dev->bid_flags |= BLKID_BID_FL_VERIFIED;
1029                 cache->bic_flags |= BLKID_BIC_FL_CHANGED;
1030
1031                 blkid_set_tag(dev, "TYPE", type, 0);
1032
1033                 DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
1034                            dev->bid_name, (long long)st.st_rdev, type));
1035         }
1036
1037         if (probe.sbbuf)
1038                 free(probe.sbbuf);
1039         if (probe.buf)
1040                 free(probe.buf);
1041         if (probe.fd >= 0)
1042                 close(probe.fd);
1043
1044         return dev;
1045 }
1046
1047 int blkid_known_fstype(const char *fstype)
1048 {
1049         struct blkid_magic *id;
1050
1051         for (id = type_array; id->bim_type; id++) {
1052                 if (strcmp(fstype, id->bim_type) == 0)
1053                         return 1;
1054         }
1055         return 0;
1056 }
1057
1058 #ifdef TEST_PROGRAM
1059 int main(int argc, char **argv)
1060 {
1061         blkid_dev dev;
1062         blkid_cache cache;
1063         int ret;
1064
1065         if (argc != 2) {
1066                 fprintf(stderr, "Usage: %s device\n"
1067                         "Probe a single device to determine type\n", argv[0]);
1068                 exit(1);
1069         }
1070         if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
1071                 fprintf(stderr, "%s: error creating cache (%d)\n",
1072                         argv[0], ret);
1073                 exit(1);
1074         }
1075         dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
1076         if (!dev) {
1077                 printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
1078                 return (1);
1079         }
1080         printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");
1081         if (dev->bid_label)
1082                 printf("LABEL='%s'\n", dev->bid_label);
1083         if (dev->bid_uuid)
1084                 printf("UUID='%s'\n", dev->bid_uuid);
1085
1086         blkid_free_dev(dev);
1087         return (0);
1088 }
1089 #endif