apps/iso9660/volume_descriptor.c

   1 /*
   2     iso9660 - An iso9660 CDI driver with Rockridge support
   3     Copyright (C) 2008  Janosch Gräf <janosch.graef@gmx.net>
   4
   5     This program is free software: you can redistribute it and/or modify
   6     it under the terms of the GNU Lesser General Public License as published by
   7     the Free Software Foundation, either version 3 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU Lesser General Public License for more details.
  14
  15     You should have received a copy of the GNU Lesser General Public License
  16     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 #include <stdint.h>
  20 #include <string.h>
  21
  22 #include "cdi/fs.h"
  23
  24 #include "iso9660_cdi.h"
  25
  26 #include "iso9660def.h"
  27 #include "volume_descriptor.h"
  28
  29 /**
  30  * Checks signature of volume descriptor
  31  *  @param sig Signature
  32  *  @return If signature is right
  33  */
  34 static int iso9660_voldesc_checksig(uint8_t sig[6]) {
  35   char right[6] = {'C','D','0','0','1',1};
  36   return memcmp(right,sig,6)==0;
  37 }
  38
  39 /**
  40  * Loads a volume descriptor
  41  *  @param fs Filesystem
  42  *  @param type Type of volume descriptor
  43  *  @param buf Buffer for volume descriptor
  44  *  @return 0=success; -1=failure
  45  */
  46 int iso9660_voldesc_load(struct cdi_fs_filesystem *fs,iso9660_voldesc_type_t type,void *buf) {
  47   debug("iso9660_voldesc_load(0x%x,%d,0x%x)\n",fs,type,buf);
  48   struct iso9660_voldesc header;
  49   size_t i;
  50
  51   for (i=ISO9660_FIRST_SECTOR;header.type!=type && header.type!=ISO9660_VOLDESC_TERM;i++) {
  52     if (iso9660_sector_read(fs,i*ISO9660_DEFAULT_SECTOR_SIZE,sizeof(header),&header)!=sizeof(header)) return -1;
  53     if (!iso9660_voldesc_checksig(header.signature)) return -1;
  54   }
  55   i--;
  56
  57   if (header.type==type) {
  58     iso9660_sector_read(fs,i*ISO9660_DEFAULT_SECTOR_SIZE,sizeof(struct iso9660_voldesc_prim),buf);
  59     return 0;
  60   }
  61   else {
  62     debug("Volume Descriptor: Wrong type: %d\n",header.type);
  63     return -1;
  64   }
  65 }