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grub/grub-core/lib/gpt.c

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/* gpt.c - Read/Verify/Write GUID Partition Tables (GPT). */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2002,2005,2006,2007,2008 Free Software Foundation, Inc.
* Copyright (C) 2014 CoreOS, 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 <http://www.gnu.org/licenses/>.
*/
#include <grub/charset.h>
#include <grub/crypto.h>
#include <grub/device.h>
#include <grub/disk.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/dl.h>
#include <grub/msdos_partition.h>
#include <grub/gpt_partition.h>
GRUB_MOD_LICENSE ("GPLv3+");
static grub_uint8_t grub_gpt_magic[] = GRUB_GPT_HEADER_MAGIC;
static grub_err_t
grub_gpt_read_entries (grub_disk_t disk, grub_gpt_t gpt,
struct grub_gpt_header *header,
void **ret_entries,
grub_size_t *ret_entries_size);
char *
grub_gpt_guid_to_str (grub_gpt_part_guid_t *guid)
{
return grub_xasprintf ("%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
grub_le_to_cpu32 (guid->data1),
grub_le_to_cpu16 (guid->data2),
grub_le_to_cpu16 (guid->data3),
guid->data4[0], guid->data4[1],
guid->data4[2], guid->data4[3],
guid->data4[4], guid->data4[5],
guid->data4[6], guid->data4[7]);
}
static grub_err_t
grub_gpt_device_partentry (grub_device_t device,
struct grub_gpt_partentry *entry)
{
grub_disk_t disk = device->disk;
grub_partition_t p;
grub_err_t err;
if (!disk || !disk->partition)
return grub_error (GRUB_ERR_BUG, "not a partition");
if (grub_strcmp (disk->partition->partmap->name, "gpt"))
return grub_error (GRUB_ERR_BAD_ARGUMENT, "not a GPT partition");
p = disk->partition;
disk->partition = p->parent;
err = grub_disk_read (disk, p->offset, p->index, sizeof (*entry), entry);
disk->partition = p;
return err;
}
grub_err_t
grub_gpt_part_label (grub_device_t device, char **label)
{
struct grub_gpt_partentry entry;
const grub_size_t name_len = ARRAY_SIZE (entry.name);
const grub_size_t label_len = name_len * GRUB_MAX_UTF8_PER_UTF16 + 1;
grub_size_t i;
grub_uint8_t *end;
if (grub_gpt_device_partentry (device, &entry))
return grub_errno;
*label = grub_malloc (label_len);
if (!*label)
return grub_errno;
for (i = 0; i < name_len; i++)
entry.name[i] = grub_le_to_cpu16 (entry.name[i]);
end = grub_utf16_to_utf8 ((grub_uint8_t *) *label, entry.name, name_len);
*end = '\0';
return GRUB_ERR_NONE;
}
grub_err_t
grub_gpt_part_uuid (grub_device_t device, char **uuid)
{
struct grub_gpt_partentry entry;
if (grub_gpt_device_partentry (device, &entry))
return grub_errno;
*uuid = grub_gpt_guid_to_str (&entry.guid);
if (!*uuid)
return grub_errno;
return GRUB_ERR_NONE;
}
static struct grub_gpt_header *
grub_gpt_get_header (grub_gpt_t gpt)
{
if (gpt->status & GRUB_GPT_PRIMARY_HEADER_VALID)
return &gpt->primary;
else if (gpt->status & GRUB_GPT_BACKUP_HEADER_VALID)
return &gpt->backup;
grub_error (GRUB_ERR_BUG, "No valid GPT header");
return NULL;
}
grub_err_t
grub_gpt_disk_uuid (grub_device_t device, char **uuid)
{
struct grub_gpt_header *header;
grub_gpt_t gpt = grub_gpt_read (device->disk);
if (!gpt)
goto done;
header = grub_gpt_get_header (gpt);
if (!header)
goto done;
*uuid = grub_gpt_guid_to_str (&header->guid);
done:
grub_gpt_free (gpt);
return grub_errno;
}
static grub_uint64_t
grub_gpt_size_to_sectors (grub_gpt_t gpt, grub_size_t size)
{
unsigned int sector_size;
grub_uint64_t sectors;
sector_size = 1U << gpt->log_sector_size;
sectors = size / sector_size;
if (size % sector_size)
sectors++;
return sectors;
}
/* Copied from grub-core/kern/disk_common.c grub_disk_adjust_range so we can
* avoid attempting to use disk->total_sectors when GRUB won't let us.
* TODO: Why is disk->total_sectors not set to GRUB_DISK_SIZE_UNKNOWN? */
static int
grub_gpt_disk_size_valid (grub_disk_t disk)
{
grub_disk_addr_t total_sectors;
/* Transform total_sectors to number of 512B blocks. */
total_sectors = disk->total_sectors << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS);
/* Some drivers have problems with disks above reasonable.
Treat unknown as 1EiB disk. While on it, clamp the size to 1EiB.
Just one condition is enough since GRUB_DISK_UNKNOWN_SIZE << ls is always
above 9EiB.
*/
if (total_sectors > (1ULL << 51))
return 0;
return 1;
}
static void
grub_gpt_lecrc32 (grub_uint32_t *crc, const void *data, grub_size_t len)
{
grub_uint32_t crc32_val;
grub_crypto_hash (GRUB_MD_CRC32, &crc32_val, data, len);
/* GRUB_MD_CRC32 always uses big endian, gpt is always little. */
*crc = grub_swap_bytes32 (crc32_val);
}
static void
grub_gpt_header_lecrc32 (grub_uint32_t *crc, struct grub_gpt_header *header)
{
grub_uint32_t old, new;
/* crc32 must be computed with the field cleared. */
old = header->crc32;
header->crc32 = 0;
grub_gpt_lecrc32 (&new, header, sizeof (*header));
header->crc32 = old;
*crc = new;
}
/* Make sure the MBR is a protective MBR and not a normal MBR. */
grub_err_t
grub_gpt_pmbr_check (struct grub_msdos_partition_mbr *mbr)
{
unsigned int i;
if (mbr->signature !=
grub_cpu_to_le16_compile_time (GRUB_PC_PARTITION_SIGNATURE))
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid MBR signature");
for (i = 0; i < sizeof (mbr->entries); i++)
if (mbr->entries[i].type == GRUB_PC_PARTITION_TYPE_GPT_DISK)
return GRUB_ERR_NONE;
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid protective MBR");
}
static grub_uint64_t
grub_gpt_entries_size (struct grub_gpt_header *gpt)
{
return (grub_uint64_t) grub_le_to_cpu32 (gpt->maxpart) *
(grub_uint64_t) grub_le_to_cpu32 (gpt->partentry_size);
}
static grub_uint64_t
grub_gpt_entries_sectors (struct grub_gpt_header *gpt,
unsigned int log_sector_size)
{
grub_uint64_t sector_bytes, entries_bytes;
sector_bytes = 1ULL << log_sector_size;
entries_bytes = grub_gpt_entries_size (gpt);
return grub_divmod64(entries_bytes + sector_bytes - 1, sector_bytes, NULL);
}
static int
is_pow2 (grub_uint32_t n)
{
return (n & (n - 1)) == 0;
}
grub_err_t
grub_gpt_header_check (struct grub_gpt_header *gpt,
unsigned int log_sector_size)
{
grub_uint32_t crc = 0, size;
grub_uint64_t start, end;
if (grub_memcmp (gpt->magic, grub_gpt_magic, sizeof (grub_gpt_magic)) != 0)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid GPT signature");
if (gpt->version != GRUB_GPT_HEADER_VERSION)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "unknown GPT version");
grub_gpt_header_lecrc32 (&crc, gpt);
if (gpt->crc32 != crc)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid GPT header crc32");
/* The header size "must be greater than or equal to 92 and must be less
* than or equal to the logical block size." */
size = grub_le_to_cpu32 (gpt->headersize);
if (size < 92U || size > (1U << log_sector_size))
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid GPT header size");
/* The partition entry size must be "a value of 128*(2^n) where n is an
* integer greater than or equal to zero (e.g., 128, 256, 512, etc.)." */
size = grub_le_to_cpu32 (gpt->partentry_size);
if (size < 128U || size % 128U || !is_pow2 (size / 128U))
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid GPT entry size");
/* The minimum entries table size is specified in terms of bytes,
* regardless of how large the individual entry size is. */
if (grub_gpt_entries_size (gpt) < GRUB_GPT_DEFAULT_ENTRIES_SIZE)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid GPT entry table size");
/* And of course there better be some space for partitions! */
start = grub_le_to_cpu64 (gpt->start);
end = grub_le_to_cpu64 (gpt->end);
if (start > end)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid usable sectors");
return GRUB_ERR_NONE;
}
static int
grub_gpt_headers_equal (grub_gpt_t gpt)
{
/* Assume headers passed grub_gpt_header_check so skip magic and version.
* Individual fields must be checked instead of just using memcmp because
* crc32, header, alternate, and partitions will all normally differ. */
if (gpt->primary.headersize != gpt->backup.headersize ||
gpt->primary.header_lba != gpt->backup.alternate_lba ||
gpt->primary.alternate_lba != gpt->backup.header_lba ||
gpt->primary.start != gpt->backup.start ||
gpt->primary.end != gpt->backup.end ||
gpt->primary.maxpart != gpt->backup.maxpart ||
gpt->primary.partentry_size != gpt->backup.partentry_size ||
gpt->primary.partentry_crc32 != gpt->backup.partentry_crc32)
return 0;
return grub_memcmp(&gpt->primary.guid, &gpt->backup.guid,
sizeof(grub_gpt_part_guid_t)) == 0;
}
static grub_err_t
grub_gpt_check_primary (grub_gpt_t gpt)
{
grub_uint64_t backup, primary, entries, entries_len, start, end;
primary = grub_le_to_cpu64 (gpt->primary.header_lba);
backup = grub_le_to_cpu64 (gpt->primary.alternate_lba);
entries = grub_le_to_cpu64 (gpt->primary.partitions);
entries_len = grub_gpt_entries_sectors(&gpt->primary, gpt->log_sector_size);
start = grub_le_to_cpu64 (gpt->primary.start);
end = grub_le_to_cpu64 (gpt->primary.end);
grub_dprintf ("gpt", "Primary GPT layout:\n"
"primary header = 0x%llx backup header = 0x%llx\n"
"entries location = 0x%llx length = 0x%llx\n"
"first usable = 0x%llx last usable = 0x%llx\n",
(unsigned long long) primary,
(unsigned long long) backup,
(unsigned long long) entries,
(unsigned long long) entries_len,
(unsigned long long) start,
(unsigned long long) end);
if (grub_gpt_header_check (&gpt->primary, gpt->log_sector_size))
return grub_errno;
if (primary != 1)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid primary GPT LBA");
if (entries <= 1 || entries+entries_len > start)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid entries location");
if (backup <= end)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid backup GPT LBA");
return GRUB_ERR_NONE;
}
static grub_err_t
grub_gpt_check_backup (grub_gpt_t gpt)
{
grub_uint64_t backup, primary, entries, entries_len, start, end;
backup = grub_le_to_cpu64 (gpt->backup.header_lba);
primary = grub_le_to_cpu64 (gpt->backup.alternate_lba);
entries = grub_le_to_cpu64 (gpt->backup.partitions);
entries_len = grub_gpt_entries_sectors(&gpt->backup, gpt->log_sector_size);
start = grub_le_to_cpu64 (gpt->backup.start);
end = grub_le_to_cpu64 (gpt->backup.end);
grub_dprintf ("gpt", "Backup GPT layout:\n"
"primary header = 0x%llx backup header = 0x%llx\n"
"entries location = 0x%llx length = 0x%llx\n"
"first usable = 0x%llx last usable = 0x%llx\n",
(unsigned long long) primary,
(unsigned long long) backup,
(unsigned long long) entries,
(unsigned long long) entries_len,
(unsigned long long) start,
(unsigned long long) end);
if (grub_gpt_header_check (&gpt->backup, gpt->log_sector_size))
return grub_errno;
if (primary != 1)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid primary GPT LBA");
if (entries <= end || entries+entries_len > backup)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid entries location");
if (backup <= end)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid backup GPT LBA");
/* If both primary and backup are valid but differ prefer the primary. */
if ((gpt->status & GRUB_GPT_PRIMARY_HEADER_VALID) &&
!grub_gpt_headers_equal (gpt))
return grub_error (GRUB_ERR_BAD_PART_TABLE, "backup GPT out of sync");
return GRUB_ERR_NONE;
}
static grub_err_t
grub_gpt_read_primary (grub_disk_t disk, grub_gpt_t gpt)
{
grub_disk_addr_t addr;
/* TODO: The gpt partmap module searches for the primary header instead
* of relying on the disk's sector size. For now trust the disk driver
* but eventually this code should match the existing behavior. */
gpt->log_sector_size = disk->log_sector_size;
grub_dprintf ("gpt", "reading primary GPT from sector 0x1\n");
addr = grub_gpt_sector_to_addr (gpt, 1);
if (grub_disk_read (disk, addr, 0, sizeof (gpt->primary), &gpt->primary))
return grub_errno;
if (grub_gpt_check_primary (gpt))
return grub_errno;
gpt->status |= GRUB_GPT_PRIMARY_HEADER_VALID;
if (grub_gpt_read_entries (disk, gpt, &gpt->primary,
&gpt->entries, &gpt->entries_size))
return grub_errno;
gpt->status |= GRUB_GPT_PRIMARY_ENTRIES_VALID;
return GRUB_ERR_NONE;
}
static grub_err_t
grub_gpt_read_backup (grub_disk_t disk, grub_gpt_t gpt)
{
void *entries = NULL;
grub_size_t entries_size;
grub_uint64_t sector;
grub_disk_addr_t addr;
/* Assumes gpt->log_sector_size == disk->log_sector_size */
if (gpt->status & GRUB_GPT_PRIMARY_HEADER_VALID)
{
sector = grub_le_to_cpu64 (gpt->primary.alternate_lba);
if (grub_gpt_disk_size_valid (disk) && sector >= disk->total_sectors)
return grub_error (GRUB_ERR_OUT_OF_RANGE,
"backup GPT located at 0x%llx, "
"beyond last disk sector at 0x%llx",
(unsigned long long) sector,
(unsigned long long) disk->total_sectors - 1);
}
else if (grub_gpt_disk_size_valid (disk))
sector = disk->total_sectors - 1;
else
return grub_error (GRUB_ERR_OUT_OF_RANGE,
"size of disk unknown, cannot locate backup GPT");
grub_dprintf ("gpt", "reading backup GPT from sector 0x%llx\n",
(unsigned long long) sector);
addr = grub_gpt_sector_to_addr (gpt, sector);
if (grub_disk_read (disk, addr, 0, sizeof (gpt->backup), &gpt->backup))
return grub_errno;
if (grub_gpt_check_backup (gpt))
return grub_errno;
/* Ensure the backup header thinks it is located where we found it. */
if (grub_le_to_cpu64 (gpt->backup.header_lba) != sector)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid backup GPT LBA");
gpt->status |= GRUB_GPT_BACKUP_HEADER_VALID;
if (grub_gpt_read_entries (disk, gpt, &gpt->backup,
&entries, &entries_size))
return grub_errno;
if (gpt->status & GRUB_GPT_PRIMARY_ENTRIES_VALID)
{
if (entries_size != gpt->entries_size ||
grub_memcmp (entries, gpt->entries, entries_size) != 0)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "backup GPT out of sync");
grub_free (entries);
}
else
{
gpt->entries = entries;
gpt->entries_size = entries_size;
}
gpt->status |= GRUB_GPT_BACKUP_ENTRIES_VALID;
return GRUB_ERR_NONE;
}
static grub_err_t
grub_gpt_read_entries (grub_disk_t disk, grub_gpt_t gpt,
struct grub_gpt_header *header,
void **ret_entries,
grub_size_t *ret_entries_size)
{
void *entries = NULL;
grub_uint32_t count, size, crc;
grub_uint64_t sector;
grub_disk_addr_t addr;
grub_size_t entries_size;
/* Grub doesn't include calloc, hence the manual overflow check. */
count = grub_le_to_cpu32 (header->maxpart);
size = grub_le_to_cpu32 (header->partentry_size);
entries_size = count *size;
if (size && entries_size / size != count)
{
grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
goto fail;
}
/* Double check that the header was validated properly. */
if (entries_size < GRUB_GPT_DEFAULT_ENTRIES_SIZE)
return grub_error (GRUB_ERR_BUG, "invalid GPT entries table size");
entries = grub_malloc (entries_size);
if (!entries)
goto fail;
sector = grub_le_to_cpu64 (header->partitions);
grub_dprintf ("gpt", "reading GPT %lu entries from sector 0x%llx\n",
(unsigned long) count,
(unsigned long long) sector);
addr = grub_gpt_sector_to_addr (gpt, sector);
if (grub_disk_read (disk, addr, 0, entries_size, entries))
goto fail;
grub_gpt_lecrc32 (&crc, entries, entries_size);
if (crc != header->partentry_crc32)
{
grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid GPT entry crc32");
goto fail;
}
*ret_entries = entries;
*ret_entries_size = entries_size;
return GRUB_ERR_NONE;
fail:
grub_free (entries);
return grub_errno;
}
grub_gpt_t
grub_gpt_read (grub_disk_t disk)
{
grub_gpt_t gpt;
grub_dprintf ("gpt", "reading GPT from %s\n", disk->name);
gpt = grub_zalloc (sizeof (*gpt));
if (!gpt)
goto fail;
if (grub_disk_read (disk, 0, 0, sizeof (gpt->mbr), &gpt->mbr))
goto fail;
/* Check the MBR but errors aren't reported beyond the status bit. */
if (grub_gpt_pmbr_check (&gpt->mbr))
grub_errno = GRUB_ERR_NONE;
else
gpt->status |= GRUB_GPT_PROTECTIVE_MBR;
/* If both the primary and backup fail report the primary's error. */
if (grub_gpt_read_primary (disk, gpt))
{
grub_error_push ();
grub_gpt_read_backup (disk, gpt);
grub_error_pop ();
}
else
grub_gpt_read_backup (disk, gpt);
/* If either succeeded clear any possible error from the other. */
if (grub_gpt_primary_valid (gpt) || grub_gpt_backup_valid (gpt))
grub_errno = GRUB_ERR_NONE;
else
goto fail;
return gpt;
fail:
grub_gpt_free (gpt);
return NULL;
}
struct grub_gpt_partentry *
grub_gpt_get_partentry (grub_gpt_t gpt, grub_uint32_t n)
{
struct grub_gpt_header *header;
grub_size_t offset;
header = grub_gpt_get_header (gpt);
if (!header)
return NULL;
if (n >= grub_le_to_cpu32 (header->maxpart))
return NULL;
offset = (grub_size_t) grub_le_to_cpu32 (header->partentry_size) * n;
return (struct grub_gpt_partentry *) ((char *) gpt->entries + offset);
}
grub_err_t
grub_gpt_repair (grub_disk_t disk, grub_gpt_t gpt)
{
/* Skip if there is nothing to do. */
if (grub_gpt_both_valid (gpt))
return GRUB_ERR_NONE;
grub_dprintf ("gpt", "repairing GPT for %s\n", disk->name);
if (disk->log_sector_size != gpt->log_sector_size)
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"GPT sector size must match disk sector size");
if (grub_gpt_primary_valid (gpt))
{
grub_uint64_t backup_header;
grub_dprintf ("gpt", "primary GPT is valid\n");
/* Relocate backup to end if disk if the disk has grown. */
backup_header = grub_le_to_cpu64 (gpt->primary.alternate_lba);
if (grub_gpt_disk_size_valid (disk) &&
disk->total_sectors - 1 > backup_header)
{
backup_header = disk->total_sectors - 1;
grub_dprintf ("gpt", "backup GPT header relocated to 0x%llx\n",
(unsigned long long) backup_header);
gpt->primary.alternate_lba = grub_cpu_to_le64 (backup_header);
}
grub_memcpy (&gpt->backup, &gpt->primary, sizeof (gpt->backup));
gpt->backup.header_lba = gpt->primary.alternate_lba;
gpt->backup.alternate_lba = gpt->primary.header_lba;
gpt->backup.partitions = grub_cpu_to_le64 (backup_header -
grub_gpt_size_to_sectors (gpt, gpt->entries_size));
}
else if (grub_gpt_backup_valid (gpt))
{
grub_dprintf ("gpt", "backup GPT is valid\n");
grub_memcpy (&gpt->primary, &gpt->backup, sizeof (gpt->primary));
gpt->primary.header_lba = gpt->backup.alternate_lba;
gpt->primary.alternate_lba = gpt->backup.header_lba;
gpt->primary.partitions = grub_cpu_to_le64_compile_time (2);
}
else
return grub_error (GRUB_ERR_BUG, "No valid GPT");
if (grub_gpt_update (gpt))
return grub_errno;
grub_dprintf ("gpt", "repairing GPT for %s successful\n", disk->name);
return GRUB_ERR_NONE;
}
grub_err_t
grub_gpt_update (grub_gpt_t gpt)
{
grub_uint32_t crc;
/* Clear status bits, require revalidation of everything. */
gpt->status &= ~(GRUB_GPT_PRIMARY_HEADER_VALID |
GRUB_GPT_PRIMARY_ENTRIES_VALID |
GRUB_GPT_BACKUP_HEADER_VALID |
GRUB_GPT_BACKUP_ENTRIES_VALID);
/* Writing headers larger than our header structure are unsupported. */
gpt->primary.headersize =
grub_cpu_to_le32_compile_time (sizeof (gpt->primary));
gpt->backup.headersize =
grub_cpu_to_le32_compile_time (sizeof (gpt->backup));
grub_gpt_lecrc32 (&crc, gpt->entries, gpt->entries_size);
gpt->primary.partentry_crc32 = crc;
gpt->backup.partentry_crc32 = crc;
grub_gpt_header_lecrc32 (&gpt->primary.crc32, &gpt->primary);
grub_gpt_header_lecrc32 (&gpt->backup.crc32, &gpt->backup);
if (grub_gpt_check_primary (gpt))
{
grub_error_push ();
return grub_error (GRUB_ERR_BUG, "Generated invalid GPT primary header");
}
gpt->status |= (GRUB_GPT_PRIMARY_HEADER_VALID |
GRUB_GPT_PRIMARY_ENTRIES_VALID);
if (grub_gpt_check_backup (gpt))
{
grub_error_push ();
return grub_error (GRUB_ERR_BUG, "Generated invalid GPT backup header");
}
gpt->status |= (GRUB_GPT_BACKUP_HEADER_VALID |
GRUB_GPT_BACKUP_ENTRIES_VALID);
return GRUB_ERR_NONE;
}
static grub_err_t
grub_gpt_write_table (grub_disk_t disk, grub_gpt_t gpt,
struct grub_gpt_header *header)
{
grub_disk_addr_t addr;
if (grub_le_to_cpu32 (header->headersize) != sizeof (*header))
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"Header size is %u, must be %u",
grub_le_to_cpu32 (header->headersize),
sizeof (*header));
addr = grub_gpt_sector_to_addr (gpt, grub_le_to_cpu64 (header->header_lba));
if (addr == 0)
return grub_error (GRUB_ERR_BUG,
"Refusing to write GPT header to address 0x0");
if (grub_disk_write (disk, addr, 0, sizeof (*header), header))
return grub_errno;
addr = grub_gpt_sector_to_addr (gpt, grub_le_to_cpu64 (header->partitions));
if (addr < 2)
return grub_error (GRUB_ERR_BUG,
"Refusing to write GPT entries to address 0x%llx",
(unsigned long long) addr);
if (grub_disk_write (disk, addr, 0, gpt->entries_size, gpt->entries))
return grub_errno;
return GRUB_ERR_NONE;
}
grub_err_t
grub_gpt_write (grub_disk_t disk, grub_gpt_t gpt)
{
grub_uint64_t backup_header;
/* TODO: update/repair protective MBRs too. */
if (!grub_gpt_both_valid (gpt))
return grub_error (GRUB_ERR_BAD_PART_TABLE, "Invalid GPT data");
/* Write the backup GPT first so if writing fails the update is aborted
* and the primary is left intact. However if the backup location is
* inaccessible we have to just skip and hope for the best, the backup
* will need to be repaired in the OS. */
backup_header = grub_le_to_cpu64 (gpt->backup.header_lba);
if (grub_gpt_disk_size_valid (disk) &&
backup_header >= disk->total_sectors)
{
grub_printf ("warning: backup GPT located at 0x%llx, "
"beyond last disk sector at 0x%llx\n",
(unsigned long long) backup_header,
(unsigned long long) disk->total_sectors - 1);
grub_printf ("warning: only writing primary GPT, "
"the backup GPT must be repaired from the OS\n");
}
else
{
grub_dprintf ("gpt", "writing backup GPT to %s\n", disk->name);
if (grub_gpt_write_table (disk, gpt, &gpt->backup))
return grub_errno;
}
grub_dprintf ("gpt", "writing primary GPT to %s\n", disk->name);
if (grub_gpt_write_table (disk, gpt, &gpt->primary))
return grub_errno;
return GRUB_ERR_NONE;
}
void
grub_gpt_free (grub_gpt_t gpt)
{
if (!gpt)
return;
grub_free (gpt->entries);
grub_free (gpt);
}
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