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/* nbdkit
* Copyright Red Hat
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Red Hat nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
#include <inttypes.h>
#include <string.h>
#include <unistd.h>
#include <nbdkit-plugin.h>
#include "byte-swapping.h"
#include "efi-crc32.h"
#include "gpt.h"
#include "isaligned.h"
#include "rounding.h"
#include "regions.h"
#include "virtual-disk.h"
#define PARTITION_TYPE_GUID "0FC63DAF-8483-4772-8E79-3D69D8477DE4"
static void create_gpt_protective_mbr (struct virtual_disk *disk,
unsigned char *out);
static void create_gpt_partition_header (struct virtual_disk *disk,
const void *pt, bool is_primary,
unsigned char *out);
static void create_gpt_partition_table (struct virtual_disk *disk,
unsigned char *out);
/* Initialize the partition table structures. */
int
create_partition_table (struct virtual_disk *disk)
{
create_gpt_protective_mbr (disk, disk->protective_mbr);
create_gpt_partition_table (disk, disk->pt);
create_gpt_partition_header (disk, disk->pt, true, disk->primary_header);
create_gpt_partition_header (disk, disk->pt, false, disk->secondary_header);
return 0;
}
static void
chs_too_large (unsigned char *out)
{
const int c = 1023, h = 254, s = 63;
out[0] = h;
out[1] = (c & 0x300) >> 2 | s;
out[2] = c & 0xff;
}
static void
create_mbr_partition_table_entry (const struct region *region,
bool bootable, int partition_id,
unsigned char *out)
{
uint64_t start_sector, nr_sectors;
uint32_t u32;
assert (IS_ALIGNED (region->start, SECTOR_SIZE));
start_sector = region->start / SECTOR_SIZE;
nr_sectors = DIV_ROUND_UP (region->len, SECTOR_SIZE);
assert (start_sector <= UINT32_MAX);
assert (nr_sectors <= UINT32_MAX);
out[0] = bootable ? 0x80 : 0;
chs_too_large (&out[1]);
out[4] = partition_id;
chs_too_large (&out[5]);
u32 = htole32 (start_sector);
memcpy (&out[8], &u32, 4);
u32 = htole32 (nr_sectors);
memcpy (&out[12], &u32, 4);
}
static void
create_gpt_protective_mbr (struct virtual_disk *disk, unsigned char *out)
{
struct region region;
uint64_t end;
/* Protective MBR creates an MBR partition with partition ID 0xee
* which covers the whole of the disk, or as much of the disk as
* expressible with MBR.
*/
region.start = 512;
end = virtual_size (&disk->regions) - 1;
if (end > UINT32_MAX * SECTOR_SIZE)
end = UINT32_MAX * SECTOR_SIZE;
region.end = end;
region.len = region.end - region.start + 1;
create_mbr_partition_table_entry (®ion, false, 0xee, &out[0x1be]);
/* Boot sector signature. */
out[0x1fe] = 0x55;
out[0x1ff] = 0xaa;
}
static void
create_gpt_partition_header (struct virtual_disk *disk,
const void *pt, bool is_primary,
unsigned char *out)
{
uint64_t nr_lbas;
struct gpt_header *header = (struct gpt_header *) out;
nr_lbas = virtual_size (&disk->regions) / SECTOR_SIZE;
memset (header, 0, sizeof *header);
memcpy (header->signature, GPT_SIGNATURE, sizeof (header->signature));
memcpy (header->revision, GPT_REVISION, sizeof (header->revision));
header->header_size = htole32 (sizeof *header);
if (is_primary) {
header->current_lba = htole64 (1);
header->backup_lba = htole64 (nr_lbas - 1);
}
else {
header->current_lba = htole64 (nr_lbas - 1);
header->backup_lba = htole64 (1);
}
header->first_usable_lba = htole64 (34);
header->last_usable_lba = htole64 (nr_lbas - 34);
if (is_primary)
header->partition_entries_lba = htole64 (2);
else
header->partition_entries_lba = htole64 (nr_lbas - 33);
header->nr_partition_entries = htole32 (GPT_MIN_PARTITIONS);
header->size_partition_entry = htole32 (GPT_PT_ENTRY_SIZE);
header->crc_partitions =
htole32 (efi_crc32 (pt, GPT_PT_ENTRY_SIZE * GPT_MIN_PARTITIONS));
/* Must be computed last. */
header->crc = htole32 (efi_crc32 (header, sizeof *header));
}
static void
create_gpt_partition_table_entry (const struct region *region,
bool bootable,
char partition_type_guid[16],
char guid[16],
unsigned char *out)
{
struct gpt_entry *entry = (struct gpt_entry *) out;
assert (sizeof (struct gpt_entry) == GPT_PT_ENTRY_SIZE);
memcpy (entry->partition_type_guid, partition_type_guid, 16);
memcpy (entry->unique_guid, guid, 16);
entry->first_lba = htole64 (region->start / SECTOR_SIZE);
entry->last_lba = htole64 (region->end / SECTOR_SIZE);
entry->attributes = htole64 (bootable ? 4 : 0);
}
static void
create_gpt_partition_table (struct virtual_disk *disk, unsigned char *out)
{
size_t j;
for (j = 0; j < nr_regions (&disk->regions); ++j) {
const struct region *region = &disk->regions.ptr[j];
/* Find the (only) partition region, which has type region_file. */
if (region->type == region_file) {
create_gpt_partition_table_entry (region, true,
PARTITION_TYPE_GUID,
disk->guid,
out);
out += GPT_PT_ENTRY_SIZE;
}
}
}
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