util-linux/volume_id/udf.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 #include "volume_id_internal.h"
  22
  23 struct volume_descriptor {
  24         struct descriptor_tag {
  25                 uint16_t        id;
  26                 uint16_t        version;
  27                 uint8_t         checksum;
  28                 uint8_t         reserved;
  29                 uint16_t        serial;
  30                 uint16_t        crc;
  31                 uint16_t        crc_len;
  32                 uint32_t        location;
  33         } __attribute__((__packed__)) tag;
  34         union {
  35                 struct anchor_descriptor {
  36                         uint32_t        length;
  37                         uint32_t        location;
  38                 } __attribute__((__packed__)) anchor;
  39                 struct primary_descriptor {
  40                         uint32_t        seq_num;
  41                         uint32_t        desc_num;
  42                         struct dstring {
  43                                 uint8_t clen;
  44                                 uint8_t c[31];
  45                         } __attribute__((__packed__)) ident;
  46                 } __attribute__((__packed__)) primary;
  47         } __attribute__((__packed__)) type;
  48 } __attribute__((__packed__));
  49
  50 struct volume_structure_descriptor {
  51         uint8_t         type;
  52         uint8_t         id[5];
  53         uint8_t         version;
  54 } __attribute__((__packed__));
  55
  56 #define UDF_VSD_OFFSET                  0x8000
  57
  58 int volume_id_probe_udf(struct volume_id *id /*,uint64_t off*/)
  59 {
  60 #define off ((uint64_t)0)
  61         struct volume_descriptor *vd;
  62         struct volume_structure_descriptor *vsd;
  63         unsigned bs;
  64         unsigned b;
  65         unsigned type;
  66         unsigned count;
  67         unsigned loc;
  68         unsigned clen;
  69
  70         dbg("probing at offset 0x%llx", (unsigned long long) off);
  71
  72         vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET, 0x200);
  73         if (vsd == NULL)
  74                 return -1;
  75
  76         if (memcmp(vsd->id, "NSR02", 5) == 0)
  77                 goto blocksize;
  78         if (memcmp(vsd->id, "NSR03", 5) == 0)
  79                 goto blocksize;
  80         if (memcmp(vsd->id, "BEA01", 5) == 0)
  81                 goto blocksize;
  82         if (memcmp(vsd->id, "BOOT2", 5) == 0)
  83                 goto blocksize;
  84         if (memcmp(vsd->id, "CD001", 5) == 0)
  85                 goto blocksize;
  86         if (memcmp(vsd->id, "CDW02", 5) == 0)
  87                 goto blocksize;
  88         if (memcmp(vsd->id, "TEA03", 5) == 0)
  89                 goto blocksize;
  90         return -1;
  91
  92 blocksize:
  93         /* search the next VSD to get the logical block size of the volume */
  94         for (bs = 0x800; bs < 0x8000; bs += 0x800) {
  95                 vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET + bs, 0x800);
  96                 if (vsd == NULL)
  97                         return -1;
  98                 dbg("test for blocksize: 0x%x", bs);
  99                 if (vsd->id[0] != '\0')
 100                         goto nsr;
 101         }
 102         return -1;
 103
 104 nsr:
 105         /* search the list of VSDs for a NSR descriptor */
 106         for (b = 0; b < 64; b++) {
 107                 vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET + (b * bs), 0x800);
 108                 if (vsd == NULL)
 109                         return -1;
 110
 111                 dbg("vsd: %c%c%c%c%c",
 112                     vsd->id[0], vsd->id[1], vsd->id[2], vsd->id[3], vsd->id[4]);
 113
 114                 if (vsd->id[0] == '\0')
 115                         return -1;
 116                 if (memcmp(vsd->id, "NSR02", 5) == 0)
 117                         goto anchor;
 118                 if (memcmp(vsd->id, "NSR03", 5) == 0)
 119                         goto anchor;
 120         }
 121         return -1;
 122
 123 anchor:
 124         /* read anchor volume descriptor */
 125         vd = volume_id_get_buffer(id, off + (256 * bs), 0x200);
 126         if (vd == NULL)
 127                 return -1;
 128
 129         type = le16_to_cpu(vd->tag.id);
 130         if (type != 2) /* TAG_ID_AVDP */
 131                 goto found;
 132
 133         /* get desriptor list address and block count */
 134         count = le32_to_cpu(vd->type.anchor.length) / bs;
 135         loc = le32_to_cpu(vd->type.anchor.location);
 136         dbg("0x%x descriptors starting at logical secor 0x%x", count, loc);
 137
 138         /* pick the primary descriptor from the list */
 139         for (b = 0; b < count; b++) {
 140                 vd = volume_id_get_buffer(id, off + ((loc + b) * bs), 0x200);
 141                 if (vd == NULL)
 142                         return -1;
 143
 144                 type = le16_to_cpu(vd->tag.id);
 145                 dbg("descriptor type %i", type);
 146
 147                 /* check validity */
 148                 if (type == 0)
 149                         goto found;
 150                 if (le32_to_cpu(vd->tag.location) != loc + b)
 151                         goto found;
 152
 153                 if (type == 1) /* TAG_ID_PVD */
 154                         goto pvd;
 155         }
 156         goto found;
 157
 158  pvd:
 159 //      volume_id_set_label_raw(id, &(vd->type.primary.ident.clen), 32);
 160
 161         clen = vd->type.primary.ident.clen;
 162         dbg("label string charsize=%i bit", clen);
 163         if (clen == 8)
 164                 volume_id_set_label_string(id, vd->type.primary.ident.c, 31);
 165         else if (clen == 16)
 166                 volume_id_set_label_unicode16(id, vd->type.primary.ident.c, BE, 31);
 167
 168  found:
 169 //      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 170 //      id->type = "udf";
 171
 172         return 0;
 173 }