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Sourcecode: udev version File versions

udf.c

/*
 * volume_id - reads filesystem label and uuid
 *
 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
 *
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation; either
 *    version 2.1 of the License, or (at your option) any later version.
 *
 *    This library is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *    Lesser General Public License for more details.
 *
 *    You should have received a copy of the GNU Lesser General Public
 *    License along with this library; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <asm/types.h>

#include "volume_id.h"
#include "logging.h"
#include "util.h"
#include "udf.h"

struct volume_descriptor {
      struct descriptor_tag {
            __u16 id;
            __u16 version;
            __u8  checksum;
            __u8  reserved;
            __u16 serial;
            __u16 crc;
            __u16 crc_len;
            __u32 location;
      } __attribute__((__packed__)) tag;
      union {
            struct anchor_descriptor {
                  __u32 length;
                  __u32 location;
            } __attribute__((__packed__)) anchor;
            struct primary_descriptor {
                  __u32 seq_num;
                  __u32 desc_num;
                  struct dstring {
                        __u8  clen;
                        __u8  c[31];
                  } __attribute__((__packed__)) ident;
            } __attribute__((__packed__)) primary;
      } __attribute__((__packed__)) type;
} __attribute__((__packed__));

struct volume_structure_descriptor {
      __u8  type;
      __u8  id[5];
      __u8  version;
} __attribute__((__packed__));

#define UDF_VSD_OFFSET              0x8000

int volume_id_probe_udf(struct volume_id *id, __u64 off)
{
      struct volume_descriptor *vd;
      struct volume_structure_descriptor *vsd;
      unsigned int bs;
      unsigned int b;
      unsigned int type;
      unsigned int count;
      unsigned int loc;
      unsigned int clen;

      dbg("probing at offset 0x%llx", (unsigned long long) off);

      vsd = (struct volume_structure_descriptor *) volume_id_get_buffer(id, off + UDF_VSD_OFFSET, 0x200);
      if (vsd == NULL)
            return -1;

      if (memcmp(vsd->id, "NSR02", 5) == 0)
            goto blocksize;
      if (memcmp(vsd->id, "NSR03", 5) == 0)
            goto blocksize;
      if (memcmp(vsd->id, "BEA01", 5) == 0)
            goto blocksize;
      if (memcmp(vsd->id, "BOOT2", 5) == 0)
            goto blocksize;
      if (memcmp(vsd->id, "CD001", 5) == 0)
            goto blocksize;
      if (memcmp(vsd->id, "CDW02", 5) == 0)
            goto blocksize;
      if (memcmp(vsd->id, "TEA03", 5) == 0)
            goto blocksize;
      return -1;

blocksize:
      /* search the next VSD to get the logical block size of the volume */
      for (bs = 0x800; bs < 0x8000; bs += 0x800) {
            vsd = (struct volume_structure_descriptor *) volume_id_get_buffer(id, off + UDF_VSD_OFFSET + bs, 0x800);
            if (vsd == NULL)
                  return -1;
            dbg("test for blocksize: 0x%x", bs);
            if (vsd->id[0] != '\0')
                  goto nsr;
      }
      return -1;

nsr:
      /* search the list of VSDs for a NSR descriptor */
      for (b = 0; b < 64; b++) {
            vsd = (struct volume_structure_descriptor *) volume_id_get_buffer(id, off + UDF_VSD_OFFSET + (b * bs), 0x800);
            if (vsd == NULL)
                  return -1;

            dbg("vsd: %c%c%c%c%c",
                vsd->id[0], vsd->id[1], vsd->id[2], vsd->id[3], vsd->id[4]);

            if (vsd->id[0] == '\0')
                  return -1;
            if (memcmp(vsd->id, "NSR02", 5) == 0)
                  goto anchor;
            if (memcmp(vsd->id, "NSR03", 5) == 0)
                  goto anchor;
      }
      return -1;

anchor:
      /* read anchor volume descriptor */
      vd = (struct volume_descriptor *) volume_id_get_buffer(id, off + (256 * bs), 0x200);
      if (vd == NULL)
            return -1;

      type = le16_to_cpu(vd->tag.id);
      if (type != 2) /* TAG_ID_AVDP */
            goto found;

      /* get desriptor list address and block count */
      count = le32_to_cpu(vd->type.anchor.length) / bs;
      loc = le32_to_cpu(vd->type.anchor.location);
      dbg("0x%x descriptors starting at logical secor 0x%x", count, loc);

      /* pick the primary descriptor from the list */
      for (b = 0; b < count; b++) {
            vd = (struct volume_descriptor *) volume_id_get_buffer(id, off + ((loc + b) * bs), 0x200);
            if (vd == NULL)
                  return -1;

            type = le16_to_cpu(vd->tag.id);
            dbg("descriptor type %i", type);

            /* check validity */
            if (type == 0)
                  goto found;
            if (le32_to_cpu(vd->tag.location) != loc + b)
                  goto found;

            if (type == 1) /* TAG_ID_PVD */
                  goto pvd;
      }
      goto found;

pvd:
      volume_id_set_label_raw(id, &(vd->type.primary.ident.clen), 32);

      clen = vd->type.primary.ident.clen;
      dbg("label string charsize=%i bit", clen);
      if (clen == 8)
            volume_id_set_label_string(id, vd->type.primary.ident.c, 31);
      else if (clen == 16)
            volume_id_set_label_unicode16(id, vd->type.primary.ident.c, BE,31);

found:
      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
      id->type = "udf";

      return 0;
}

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