LXR busybox/util-linux/volume

   1/*
   2 * volume_id - reads filesystem label and uuid
   3 *
   4 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
   5 *
   6 *      This library is free software; you can redistribute it and/or
   7 *      modify it under the terms of the GNU Lesser General Public
   8 *      License as published by the Free Software Foundation; either
   9 *      version 2.1 of the License, or (at your option) any later version.
  10 *
  11 *      This library is distributed in the hope that it will be useful,
  12 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14 *      Lesser General Public License for more details.
  15 *
  16 *      You should have received a copy of the GNU Lesser General Public
  17 *      License along with this library; if not, write to the Free Software
  18 *      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19 */
  20
  21#include "volume_id_internal.h"
  22
  23#define ISO_SUPERBLOCK_OFFSET           0x8000
  24#define ISO_SECTOR_SIZE                 0x800
  25#define ISO_VD_OFFSET                   (ISO_SUPERBLOCK_OFFSET + ISO_SECTOR_SIZE)
  26#define ISO_VD_PRIMARY                  0x1
  27#define ISO_VD_SUPPLEMENTARY            0x2
  28#define ISO_VD_END                      0xff
  29#define ISO_VD_MAX                      16
  30
  31struct iso_volume_descriptor {
  32        uint8_t         vd_type;
  33        uint8_t         vd_id[5];
  34        uint8_t         vd_version;
  35        uint8_t         flags;
  36        uint8_t         system_id[32];
  37        uint8_t         volume_id[32];
  38        uint8_t         unused[8];
  39        uint8_t         space_size[8];
  40        uint8_t         escape_sequences[8];
  41} __attribute__((__packed__));
  42
  43struct high_sierra_volume_descriptor {
  44        uint8_t         foo[8];
  45        uint8_t         type;
  46        uint8_t         id[4];
  47        uint8_t         version;
  48} __attribute__((__packed__));
  49
  50int volume_id_probe_iso9660(struct volume_id *id, uint64_t off)
  51{
  52        uint8_t *buf;
  53        struct iso_volume_descriptor *is;
  54        struct high_sierra_volume_descriptor *hs;
  55
  56        dbg("probing at offset 0x%llx", (unsigned long long) off);
  57
  58        buf = volume_id_get_buffer(id, off + ISO_SUPERBLOCK_OFFSET, 0x200);
  59        if (buf == NULL)
  60                return -1;
  61
  62        is = (struct iso_volume_descriptor *) buf;
  63
  64        if (memcmp(is->vd_id, "CD001", 5) == 0) {
  65                int vd_offset;
  66                int i;
  67
  68                dbg("read label from PVD");
  69//              volume_id_set_label_raw(id, is->volume_id, 32);
  70                volume_id_set_label_string(id, is->volume_id, 32);
  71
  72                dbg("looking for SVDs");
  73                vd_offset = ISO_VD_OFFSET;
  74                for (i = 0; i < ISO_VD_MAX; i++) {
  75                        uint8_t svd_label[64];
  76
  77                        is = volume_id_get_buffer(id, off + vd_offset, 0x200);
  78                        if (is == NULL || is->vd_type == ISO_VD_END)
  79                                break;
  80                        if (is->vd_type != ISO_VD_SUPPLEMENTARY)
  81                                continue;
  82
  83                        dbg("found SVD at offset 0x%llx", (unsigned long long) (off + vd_offset));
  84                        if (memcmp(is->escape_sequences, "%/@", 3) == 0
  85                         || memcmp(is->escape_sequences, "%/C", 3) == 0
  86                         || memcmp(is->escape_sequences, "%/E", 3) == 0
  87                        ) {
  88                                dbg("Joliet extension found");
  89                                volume_id_set_unicode16((char *)svd_label, sizeof(svd_label), is->volume_id, BE, 32);
  90                                if (memcmp(id->label, svd_label, 16) == 0) {
  91                                        dbg("SVD label is identical, use the possibly longer PVD one");
  92                                        break;
  93                                }
  94
  95//                              volume_id_set_label_raw(id, is->volume_id, 32);
  96                                volume_id_set_label_string(id, svd_label, 32);
  97//                              strcpy(id->type_version, "Joliet Extension");
  98                                goto found;
  99                        }
 100                        vd_offset += ISO_SECTOR_SIZE;
 101                }
 102                goto found;
 103        }
 104
 105        hs = (struct high_sierra_volume_descriptor *) buf;
 106
 107        if (memcmp(hs->id, "CDROM", 5) == 0) {
 108//              strcpy(id->type_version, "High Sierra");
 109                goto found;
 110        }
 111
 112        return -1;
 113
 114 found:
 115//      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 116//      id->type = "iso9660";
 117
 118        return 0;
 119}
 120