extras/volume_id/volume_id/iso9660/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
  21 #ifndef _GNU_SOURCE
  22 #define _GNU_SOURCE 1
  23 #endif
  24
  25 #ifdef HAVE_CONFIG_H
  26 #  include <config.h>
  27 #endif
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <string.h>
  33 #include <errno.h>
  34 #include <ctype.h>
  35 #include <asm/types.h>
  36
  37 #include "../volume_id.h"
  38 #include "../logging.h"
  39 #include "../util.h"
  40 #include "iso9660.h"
  41
  42 #define ISO_SUPERBLOCK_OFFSET           0x8000
  43 #define ISO_SECTOR_SIZE                 0x800
  44 #define ISO_VD_OFFSET                   (ISO_SUPERBLOCK_OFFSET + ISO_SECTOR_SIZE)
  45 #define ISO_VD_PRIMARY                  0x1
  46 #define ISO_VD_SUPPLEMENTARY            0x2
  47 #define ISO_VD_END                      0xff
  48 #define ISO_VD_MAX                      16
  49
  50 int volume_id_probe_iso9660(struct volume_id *id, __u64 off)
  51 {
  52         union iso_super_block {
  53                 struct iso_header {
  54                         __u8    type;
  55                         __u8    id[5];
  56                         __u8    version;
  57                         __u8    unused1;
  58                         __u8            system_id[32];
  59                         __u8            volume_id[32];
  60                 } __attribute__((__packed__)) iso;
  61                 struct hs_header {
  62                         __u8    foo[8];
  63                         __u8    type;
  64                         __u8    id[4];
  65                         __u8    version;
  66                 } __attribute__((__packed__)) hs;
  67         } __attribute__((__packed__)) *is;
  68
  69         is = (union iso_super_block *) volume_id_get_buffer(id, off + ISO_SUPERBLOCK_OFFSET, 0x200);
  70         if (is == NULL)
  71                 return -1;
  72
  73         if (strncmp(is->iso.id, "CD001", 5) == 0) {
  74                 char root_label[VOLUME_ID_LABEL_SIZE+1];
  75                 int vd_offset;
  76                 int i;
  77                 int found_svd;
  78
  79                 memset(root_label, 0, sizeof(root_label));
  80                 strncpy(root_label, is->iso.volume_id, sizeof(root_label)-1);
  81
  82                 found_svd = 0;
  83                 vd_offset = ISO_VD_OFFSET;
  84                 for (i = 0; i < ISO_VD_MAX; i++) {
  85                         is = (union iso_super_block *) volume_id_get_buffer(id, off + vd_offset, 0x200);
  86                         if (is == NULL || is->iso.type == ISO_VD_END)
  87                                 break;
  88                         if (is->iso.type == ISO_VD_SUPPLEMENTARY) {
  89                                 dbg("found ISO supplementary VD at offset 0x%llx", off + vd_offset);
  90                                 volume_id_set_label_raw(id, is->iso.volume_id, 32);
  91                                 volume_id_set_label_unicode16(id, is->iso.volume_id, BE, 32);
  92                                 found_svd = 1;
  93                                 break;
  94                         }
  95                         vd_offset += ISO_SECTOR_SIZE;
  96                 }
  97
  98                 if (!found_svd ||
  99                     (found_svd && !strncmp(root_label, id->label, 16)))
 100                 {
 101                         volume_id_set_label_raw(id, root_label, 32);
 102                         volume_id_set_label_string(id, root_label, 32);
 103                 }
 104                 goto found;
 105         }
 106         if (strncmp(is->hs.id, "CDROM", 5) == 0)
 107                 goto found;
 108         return -1;
 109
 110 found:
 111         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 112         id->type = "iso9660";
 113
 114         return 0;
 115 }