util-linux/volume_id/iso9660.c

   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
  37 struct 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
  49 struct 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
  56 int 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 }