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//config:config FEATURE_VOLUMEID_ISO9660
  21//config:       bool "iso9660 filesystem"
  22//config:       default y
  23//config:       depends on VOLUMEID
  24
  25//kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_ISO9660) += iso9660.o
  26
  27#include "volume_id_internal.h"
  28
  29#define ISO_SUPERBLOCK_OFFSET           0x8000
  30#define ISO_SECTOR_SIZE                 0x800
  31#define ISO_VD_OFFSET                   (ISO_SUPERBLOCK_OFFSET + ISO_SECTOR_SIZE)
  32#define ISO_VD_PRIMARY                  0x1
  33#define ISO_VD_SUPPLEMENTARY            0x2
  34#define ISO_VD_END                      0xff
  35#define ISO_VD_MAX                      16
  36
  37struct iso_volume_descriptor {
  38        uint8_t         vd_type;
  39        uint8_t         vd_id[5];
  40        uint8_t         vd_version;
  41        uint8_t         flags;
  42        uint8_t         system_id[32];
  43        uint8_t         volume_id[32];
  44        uint8_t         unused[8];
  45        uint8_t         space_size[8];
  46        uint8_t         escape_sequences[8];
  47} PACKED;
  48
  49struct high_sierra_volume_descriptor {
  50        uint8_t         foo[8];
  51        uint8_t         type;
  52        uint8_t         id[4];
  53        uint8_t         version;
  54} PACKED;
  55
  56int FAST_FUNC volume_id_probe_iso9660(struct volume_id *id /*,uint64_t off*/)
  57{
  58#define off ((uint64_t)0)
  59        uint8_t *buf;
  60        struct iso_volume_descriptor *is;
  61        struct high_sierra_volume_descriptor *hs;
  62
  63        dbg("probing at offset 0x%llx", (unsigned long long) off);
  64
  65        buf = volume_id_get_buffer(id, off + ISO_SUPERBLOCK_OFFSET, 0x200);
  66        if (buf == NULL)
  67                return -1;
  68
  69        is = (struct iso_volume_descriptor *) buf;
  70
  71        if (memcmp(is->vd_id, "CD001", 5) == 0) {
  72                int vd_offset;
  73                int i;
  74
  75                dbg("read label from PVD");
  76//              volume_id_set_label_raw(id, is->volume_id, 32);
  77                volume_id_set_label_string(id, is->volume_id, 32);
  78
  79                dbg("looking for SVDs");
  80                vd_offset = ISO_VD_OFFSET;
  81                for (i = 0; i < ISO_VD_MAX; i++) {
  82                        uint8_t svd_label[64];
  83
  84                        is = volume_id_get_buffer(id, off + vd_offset, 0x200);
  85                        if (is == NULL || is->vd_type == ISO_VD_END)
  86                                break;
  87                        if (is->vd_type != ISO_VD_SUPPLEMENTARY)
  88                                continue;
  89
  90                        dbg("found SVD at offset 0x%llx", (unsigned long long) (off + vd_offset));
  91                        if (memcmp(is->escape_sequences, "%/@", 3) == 0
  92                         || memcmp(is->escape_sequences, "%/C", 3) == 0
  93                         || memcmp(is->escape_sequences, "%/E", 3) == 0
  94                        ) {
  95                                dbg("Joliet extension found");
  96                                volume_id_set_unicode16((char *)svd_label, sizeof(svd_label), is->volume_id, BE, 32);
  97                                if (memcmp(id->label, svd_label, 16) == 0) {
  98                                        dbg("SVD label is identical, use the possibly longer PVD one");
  99                                        break;
 100                                }
 101
 102//                              volume_id_set_label_raw(id, is->volume_id, 32);
 103                                volume_id_set_label_string(id, svd_label, 32);
 104//                              strcpy(id->type_version, "Joliet Extension");
 105                                goto found;
 106                        }
 107                        vd_offset += ISO_SECTOR_SIZE;
 108                }
 109                goto found;
 110        }
 111
 112        hs = (struct high_sierra_volume_descriptor *) buf;
 113
 114        if (memcmp(hs->id, "CDROM", 5) == 0) {
 115//              strcpy(id->type_version, "High Sierra");
 116                goto found;
 117        }
 118
 119        return -1;
 120
 121 found:
 122//      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 123        IF_FEATURE_BLKID_TYPE(id->type = "iso9660";)
 124
 125        return 0;
 126}
 127