busybox/util-linux/volume_id/iso9660.c
Denis Vlasenko de7684a309 support for mount by label (not yet tested)
Also adds findfs applet. Closes bug 1143.
2008-02-18 21:08:49 +00:00

119 lines
3.3 KiB
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
*/
#include "volume_id_internal.h"
#define ISO_SUPERBLOCK_OFFSET 0x8000
#define ISO_SECTOR_SIZE 0x800
#define ISO_VD_OFFSET (ISO_SUPERBLOCK_OFFSET + ISO_SECTOR_SIZE)
#define ISO_VD_PRIMARY 0x1
#define ISO_VD_SUPPLEMENTARY 0x2
#define ISO_VD_END 0xff
#define ISO_VD_MAX 16
struct iso_volume_descriptor {
uint8_t vd_type;
uint8_t vd_id[5];
uint8_t vd_version;
uint8_t flags;
uint8_t system_id[32];
uint8_t volume_id[32];
uint8_t unused[8];
uint8_t space_size[8];
uint8_t escape_sequences[8];
} __attribute__((__packed__));
struct high_sierra_volume_descriptor {
uint8_t foo[8];
uint8_t type;
uint8_t id[4];
uint8_t version;
} __attribute__((__packed__));
int volume_id_probe_iso9660(struct volume_id *id, uint64_t off)
{
uint8_t *buf;
struct iso_volume_descriptor *is;
struct high_sierra_volume_descriptor *hs;
dbg("probing at offset 0x%llx", (unsigned long long) off);
buf = volume_id_get_buffer(id, off + ISO_SUPERBLOCK_OFFSET, 0x200);
if (buf == NULL)
return -1;
is = (struct iso_volume_descriptor *) buf;
if (memcmp(is->vd_id, "CD001", 5) == 0) {
int vd_offset;
int i;
dbg("read label from PVD");
volume_id_set_label_raw(id, is->volume_id, 32);
volume_id_set_label_string(id, is->volume_id, 32);
dbg("looking for SVDs");
vd_offset = ISO_VD_OFFSET;
for (i = 0; i < ISO_VD_MAX; i++) {
uint8_t svd_label[64];
is = volume_id_get_buffer(id, off + vd_offset, 0x200);
if (is == NULL || is->vd_type == ISO_VD_END)
break;
if (is->vd_type != ISO_VD_SUPPLEMENTARY)
continue;
dbg("found SVD at offset 0x%llx", (unsigned long long) (off + vd_offset));
if (memcmp(is->escape_sequences, "%/@", 3) == 0||
memcmp(is->escape_sequences, "%/C", 3) == 0||
memcmp(is->escape_sequences, "%/E", 3) == 0) {
dbg("Joliet extension found");
volume_id_set_unicode16((char *)svd_label, sizeof(svd_label), is->volume_id, BE, 32);
if (memcmp(id->label, svd_label, 16) == 0) {
dbg("SVD label is identical, use the possibly longer PVD one");
break;
}
volume_id_set_label_raw(id, is->volume_id, 32);
volume_id_set_label_string(id, svd_label, 32);
strcpy(id->type_version, "Joliet Extension");
goto found;
}
vd_offset += ISO_SECTOR_SIZE;
}
goto found;
}
hs = (struct high_sierra_volume_descriptor *) buf;
if (memcmp(hs->id, "CDROM", 5) == 0) {
strcpy(id->type_version, "High Sierra");
goto found;
}
return -1;
found:
volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
id->type = "iso9660";
return 0;
}