/*
 * volume_id - reads filesystem label and uuid
 *
 * Copyright (C) 2007 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, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <byteswap.h>

#include "libvolume_id.h"
#include "libvolume_id-private.h"

/* http://www.snia.org/standards/home */

#define DDF_GUID_LENGTH			24
#define DDF_REV_LENGTH			8

struct ddf_header {
	uint8_t		signature[4];
	uint32_t	crc;
	uint8_t		guid[DDF_GUID_LENGTH];
	uint8_t		ddf_rev[DDF_REV_LENGTH];
} PACKED;

int volume_id_probe_ddf_raid(struct volume_id *id, uint64_t off, uint64_t size)
{
	uint64_t ddf_off;
	const uint8_t *buf;
	struct ddf_header *ddf;

	info("probing at offset 0x%" PRIx64 ", size 0x%" PRIx64 "\n", off, size);
	if (size < 0x30000)
		return -1;

	/* header at last sector */
	ddf_off = ((size / 0x200)-1) * 0x200;
	buf = volume_id_get_buffer(id, off + ddf_off, 0x200);
	if (buf == NULL)
		return -1;
	ddf = (struct ddf_header *) buf;
	if (memcmp(ddf->signature, "\x11\xde\x11\xde", 4) == 0) {
		info("header (little endian) found at %" PRIu64 "\n", (off + ddf_off));
		goto found;
	}
	if (memcmp(ddf->signature, "\xde\x11\xde\x11", 4) == 0) {
		info("header (big endian) found at %" PRIu64 "\n", (off + ddf_off));
		goto found;
	}

	/* adaptec non-standard header location */
	ddf_off = ((size / 0x200)-257) * 0x200;
	buf = volume_id_get_buffer(id, off + ddf_off, 0x200);
	if (buf == NULL)
		return -1;
	ddf = (struct ddf_header *) buf;
	if (memcmp(ddf->signature, "\x11\xde\x11\xde", 4) == 0) {
		info("header adaptec (little endian) found at %" PRIu64 "\n", (off + ddf_off));
		goto found;
	}
	if (memcmp(ddf->signature, "\xde\x11\xde\x11", 4) == 0) {
		info("header adaptec (big endian) found at %" PRIu64 "\n", (off + ddf_off));
		goto found;
	}

	return -1;
found:
	volume_id_set_uuid(id, ddf->guid, DDF_GUID_LENGTH, UUID_STRING);
	snprintf(id->type_version, DDF_REV_LENGTH + 1, "%s", ddf->ddf_rev);
	volume_id_set_usage(id, VOLUME_ID_RAID);
	id->type = "ddf_raid_member";
	return 0;
}