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systemd-stable/extras/volume_id/lib/iso9660.c
2007-05-25 03:35:18 +02:00

125 lines
3.0 KiB
C

/*
* volume_id - reads filesystem label and uuid
*
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation version 2 of the License.
*/
#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 "libvolume_id.h"
#include "util.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 type;
uint8_t id[5];
uint8_t 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];
} PACKED;
struct high_sierra_volume_descriptor {
uint8_t foo[8];
uint8_t type;
uint8_t id[5];
uint8_t version;
} PACKED;
int volume_id_probe_iso9660(struct volume_id *id, uint64_t off, uint64_t size)
{
uint8_t *buf;
struct iso_volume_descriptor *is;
struct high_sierra_volume_descriptor *hs;
info("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->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 = (struct iso_volume_descriptor *) volume_id_get_buffer(id, off + vd_offset, 0x200);
if (is == NULL || is->type == ISO_VD_END)
break;
if (is->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(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;
}