systemd-stable/extras/volume_id/lib/hpfs.c

/*
 * volume_id - reads filesystem label and uuid
 *
 * Copyright (C) 2005 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"

struct hpfs_super
{
	uint8_t		magic[4];
	uint8_t		version;
} PACKED;

#define HPFS_SUPERBLOCK_OFFSET			0x2000

int volume_id_probe_hpfs(struct volume_id *id, uint64_t off)
{
	struct hpfs_super *hs;

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

	hs = (struct hpfs_super *) volume_id_get_buffer(id, off + HPFS_SUPERBLOCK_OFFSET, 0x200);
	if (hs == NULL)
		return -1;

	if (memcmp(hs->magic, "\x49\xe8\x95\xf9", 4) == 0) {
		sprintf(id->type_version, "%u", hs->version);

		volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
		id->type = "hpfs";
		return 0;
	}

	return -1;
}