/* bsdlabel.c - Read BSD style partition tables.  */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2002,2004,2005,2006,2007,2008,2009  Free Software Foundation, Inc.
 *
 *  GRUB 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 3 of the License, or
 *(at your option) any later version.
 *
 *  GRUB 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 GRUB.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <grub/partition.h>
#include <grub/bsdlabel.h>
#include <grub/disk.h>
#include <grub/mm.h>
#include <grub/misc.h>

struct grub_partition_map grub_bsdlabel_partition_map;

static grub_err_t
bsdlabel_partition_map_iterate(grub_disk_t disk,
	int (*hook) (grub_disk_t disk,
		const grub_partition_t partition,
		void *closure),
	void *closure) {
	struct grub_partition_bsd_disk_label label;
	struct grub_partition p;
	grub_disk_addr_t delta = 0;
	unsigned pos;

	/* BSDLabel offsets are absolute even when it's embed inside partition.  */
	delta = grub_partition_get_start (disk->partition);

	/* Read the BSD label.  */
	if (grub_disk_read (disk, GRUB_PC_PARTITION_BSD_LABEL_SECTOR, 0, sizeof (label), &label)) {
		return grub_errno;
	}

	/* Check if it is valid.  */
	if (label.magic != grub_cpu_to_le32 (GRUB_PC_PARTITION_BSD_LABEL_MAGIC)) {
		return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature");
	}

	pos = sizeof (label) + GRUB_PC_PARTITION_BSD_LABEL_SECTOR * GRUB_DISK_SECTOR_SIZE;

	for (p.number = 0;
		p.number < grub_cpu_to_le16 (label.num_partitions);
		p.number++) {
		struct grub_partition_bsd_entry be;

		p.offset = pos / GRUB_DISK_SECTOR_SIZE;
		p.index = pos % GRUB_DISK_SECTOR_SIZE;

		if (grub_disk_read (disk, p.offset, p.index, sizeof (be), &be)) {
			return grub_errno;
		}

		p.start = grub_le_to_cpu32 (be.offset) - delta;
		p.len = grub_le_to_cpu32 (be.size);
		p.partmap = &grub_bsdlabel_partition_map;

		if (be.fs_type != GRUB_PC_PARTITION_BSD_TYPE_UNUSED) {
			if (hook (disk, &p, closure)) {
				return grub_errno;
			}
		}

		pos += sizeof (struct grub_partition_bsd_entry);
	}

	return GRUB_ERR_NONE;
}

/* Partition map type.  */
struct grub_partition_map grub_bsdlabel_partition_map = {
	.name = "bsd",
	.iterate = bsdlabel_partition_map_iterate,
};