/*
gpt.[ch]
Copyright (C) 2000-2001 Dell Computer Corporation <Matt_Domsch@dell.com>
EFI GUID Partition Table handling
Per Intel EFI Specification v1.02
http://developer.intel.com/technology/efi/efi.htm
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/>.
*/
#define _FILE_OFFSET_BITS 64
#include "gpt.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <inttypes.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <endian.h>
#include <byteswap.h>
#include <linux/fs.h>
#include "crc32.h"
#include "kpartx.h"
#if BYTE_ORDER == LITTLE_ENDIAN
# define __le16_to_cpu(x) (uint16_t)(x)
# define __le32_to_cpu(x) (uint32_t)(x)
# define __le64_to_cpu(x) (uint64_t)(x)
# define __cpu_to_le32(x) (x)
#elif BYTE_ORDER == BIG_ENDIAN
# define __le16_to_cpu(x) bswap_16(x)
# define __le32_to_cpu(x) bswap_32(x)
# define __le64_to_cpu(x) bswap_64(x)
# define __cpu_to_le32(x) bswap_32(x)
#endif
#ifndef BLKGETLASTSECT
#define BLKGETLASTSECT _IO(0x12,108) /* get last sector of block device */
#endif
#ifndef BLKGETSIZE
#define BLKGETSIZE _IO(0x12,96) /* return device size */
#endif
#ifndef BLKSSZGET
#define BLKSSZGET _IO(0x12,104) /* get block device sector size */
#endif
#ifndef BLKGETSIZE64
#define BLKGETSIZE64 _IOR(0x12,114,sizeof(uint64_t)) /* return device size in bytes (u64 *arg) */
#endif
struct blkdev_ioctl_param {
unsigned int block;
size_t content_length;
char * block_contents;
};
/**
* efi_crc32() - EFI version of crc32 function
* @buf: buffer to calculate crc32 of
* @len - length of buf
*
* Description: Returns EFI-style CRC32 value for @buf
*
* This function uses the little endian Ethernet polynomial
* but seeds the function with ~0, and xor's with ~0 at the end.
* Note, the EFI Specification, v1.02, has a reference to
* Dr. Dobbs Journal, May 1994 (actually it's in May 1992).
*/
static inline uint32_t
efi_crc32(const void *buf, unsigned long len)
{
return (crc32(~0L, buf, len) ^ ~0L);
}
/**
* is_pmbr_valid(): test Protective MBR for validity
* @mbr: pointer to a legacy mbr structure
*
* Description: Returns 1 if PMBR is valid, 0 otherwise.
* Validity depends on two things:
* 1) MSDOS signature is in the last two bytes of the MBR
* 2) One partition of type 0xEE is found
*/
static int
is_pmbr_valid(legacy_mbr *mbr)
{
int i, found = 0, signature = 0;
if (!mbr)
return 0;
signature = (__le16_to_cpu(mbr->signature) == MSDOS_MBR_SIGNATURE);
for (i = 0; signature && i < 4; i++) {
if (mbr->partition[i].sys_type ==
EFI_PMBR_OSTYPE_EFI_GPT) {
found = 1;
break;
}
}
return (signature && found);
}
/************************************************************
* _get_num_sectors
* Requires:
* - filedes is an open file descriptor, suitable for reading
* Modifies: nothing
* Returns:
* Last LBA value on success
* 0 on error
*
* Try getting BLKGETSIZE64 and BLKSSZGET first,
* then BLKGETSIZE if necessary.
* Kernels 2.4.15-2.4.18 and 2.5.0-2.5.3 have a broken BLKGETSIZE64
* which returns the number of 512-byte sectors, not the size of
* the disk in bytes. Fixed in kernels 2.4.18-pre8 and 2.5.4-pre3.
************************************************************/
static uint64_t
_get_num_sectors(int filedes)
{
int rc;
uint64_t bytes=0;
rc = ioctl(filedes, BLKGETSIZE64, &bytes);
if (!rc)
return bytes / get_sector_size(filedes);
return 0;
}
/************************************************************
* last_lba(): return number of last logical block of device
*
* @fd
*
* Description: returns Last LBA value on success, 0 on error.
* Notes: The value st_blocks gives the size of the file
* in 512-byte blocks, which is OK if
* EFI_BLOCK_SIZE_SHIFT == 9.
************************************************************/
static uint64_t
last_lba(int filedes)
{
int rc;
uint64_t sectors = 0;
struct stat s;
memset(&s, 0, sizeof (s));
rc = fstat(filedes, &s);
if (rc == -1) {
fprintf(stderr, "last_lba() could not stat: %s\n",
strerror(errno));
return 0;
}
if (S_ISBLK(s.st_mode)) {
sectors = _get_num_sectors(filedes);
} else {
fprintf(stderr,
"last_lba(): I don't know how to handle files with mode %x\n",
s.st_mode);
sectors = 1;
}
return sectors ? sectors - 1 : 0;
}
static ssize_t
read_lastoddsector(int fd, void *buffer, size_t count)
{
int rc;
struct blkdev_ioctl_param ioctl_param;
if (!buffer) return 0;
ioctl_param.block = 0; /* read the last sector */
ioctl_param.content_length = count;
ioctl_param.block_contents = buffer;
rc = ioctl(fd, BLKGETLASTSECT, &ioctl_param);
if (rc == -1) perror("read failed");
return !rc;
}
static ssize_t
read_lba(int fd, uint64_t lba, void *buffer, size_t bytes)
{
int sector_size = get_sector_size(fd);
off_t offset = lba * sector_size;
uint64_t lastlba;
ssize_t bytesread;
if (lseek(fd, offset, SEEK_SET) < 0)
return 0;
bytesread = read(fd, buffer, bytes);
lastlba = last_lba(fd);
if (!lastlba)
return bytesread;
/* Kludge. This is necessary to read/write the last
block of an odd-sized disk, until Linux 2.5.x kernel fixes.
This is only used by gpt.c, and only to read
one sector, so we don't have to be fancy.
*/
if (!bytesread && !(lastlba & 1) && lba == lastlba) {
bytesread = read_lastoddsector(fd, buffer, bytes);
}
return bytesread;
}
/**
* alloc_read_gpt_entries(): reads partition entries from disk
* @fd is an open file descriptor to the whole disk
* @gpt is a buffer into which the GPT will be put
* Description: Returns ptes on success, NULL on error.
* Allocates space for PTEs based on information found in @gpt.
* Notes: remember to free pte when you're done!
*/
static gpt_entry *
alloc_read_gpt_entries(int fd, gpt_header * gpt)
{
gpt_entry *pte;
size_t count = __le32_to_cpu(gpt->num_partition_entries) *
__le32_to_cpu(gpt->sizeof_partition_entry);
if (!count) return NULL;
pte = (gpt_entry *)malloc(count);
if (!pte)
return NULL;
memset(pte, 0, count);
if (!read_lba(fd, __le64_to_cpu(gpt->partition_entry_lba), pte,
count)) {
free(pte);
return NULL;
}
return pte;
}
/**
* alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
* @fd is an open file descriptor to the whole disk
* @lba is the Logical Block Address of the partition table
*
* Description: returns GPT header on success, NULL on error. Allocates
* and fills a GPT header starting at @ from @bdev.
* Note: remember to free gpt when finished with it.
*/
static gpt_header *
alloc_read_gpt_header(int fd, uint64_t lba)
{
gpt_header *gpt;
gpt = (gpt_header *)
malloc(sizeof (gpt_header));
if (!gpt)
return NULL;
memset(gpt, 0, sizeof (*gpt));
if (!read_lba(fd, lba, gpt, sizeof (gpt_header))) {
free(gpt);
return NULL;
}
return gpt;
}
/**
* is_gpt_valid() - tests one GPT header and PTEs for validity
* @fd is an open file descriptor to the whole disk
* @lba is the logical block address of the GPT header to test
* @gpt is a GPT header ptr, filled on return.
* @ptes is a PTEs ptr, filled on return.
*
* Description: returns 1 if valid, 0 on error.
* If valid, returns pointers to newly allocated GPT header and PTEs.
*/
static int
is_gpt_valid(int fd, uint64_t lba,
gpt_header ** gpt, gpt_entry ** ptes)
{
int rc = 0; /* default to not valid */
uint32_t crc, origcrc;
if (!gpt || !ptes)
return 0;
if (!(*gpt = alloc_read_gpt_header(fd, lba)))
return 0;
/* Check the GUID Partition Table signature */
if (__le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
/*
printf("GUID Partition Table Header signature is wrong: %" PRIx64" != %" PRIx64 "\n",
__le64_to_cpu((*gpt)->signature), GUID_PT_HEADER_SIGNATURE);
*/
free(*gpt);
*gpt = NULL;
return rc;
}
/* Check the GUID Partition Table Header CRC */
origcrc = __le32_to_cpu((*gpt)->header_crc32);
(*gpt)->header_crc32 = 0;
crc = efi_crc32(*gpt, __le32_to_cpu((*gpt)->header_size));
if (crc != origcrc) {
// printf( "GPTH CRC check failed, %x != %x.\n", origcrc, crc);
(*gpt)->header_crc32 = __cpu_to_le32(origcrc);
free(*gpt);
*gpt = NULL;
return 0;
}
(*gpt)->header_crc32 = __cpu_to_le32(origcrc);
/* Check that the my_lba entry points to the LBA
* that contains the GPT we read */
if (__le64_to_cpu((*gpt)->my_lba) != lba) {
/*
printf( "my_lba % PRIx64 "x != lba %"PRIx64 "x.\n",
__le64_to_cpu((*gpt)->my_lba), lba);
*/
free(*gpt);
*gpt = NULL;
return 0;
}
/* Check that sizeof_partition_entry has the correct value */
if (__le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
// printf("GUID partition entry size check failed.\n");
free(*gpt);
*gpt = NULL;
return 0;
}
if (!(*ptes = alloc_read_gpt_entries(fd, *gpt))) {
free(*gpt);
*gpt = NULL;
return 0;
}
/* Check the GUID Partition Entry Array CRC */
crc = efi_crc32(*ptes,
__le32_to_cpu((*gpt)->num_partition_entries) *
__le32_to_cpu((*gpt)->sizeof_partition_entry));
if (crc != __le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
// printf("GUID Partitition Entry Array CRC check failed.\n");
free(*gpt);
*gpt = NULL;
free(*ptes);
*ptes = NULL;
return 0;
}
/* We're done, all's well */
return 1;
}
/**
* compare_gpts() - Search disk for valid GPT headers and PTEs
* @pgpt is the primary GPT header
* @agpt is the alternate GPT header
* @lastlba is the last LBA number
* Description: Returns nothing. Sanity checks pgpt and agpt fields
* and prints warnings on discrepancies.
*
*/
static void
compare_gpts(gpt_header *pgpt, gpt_header *agpt, uint64_t lastlba)
{
int error_found = 0;
if (!pgpt || !agpt)
return;
if (__le64_to_cpu(pgpt->my_lba) != __le64_to_cpu(agpt->alternate_lba)) {
error_found++;
fprintf(stderr,
"GPT:Primary header LBA != Alt. header alternate_lba\n");
#ifdef DEBUG
fprintf(stderr, "GPT:%" PRIx64 " != %" PRIx64 "\n",
__le64_to_cpu(pgpt->my_lba),
__le64_to_cpu(agpt->alternate_lba));
#endif
}
if (__le64_to_cpu(pgpt->alternate_lba) != __le64_to_cpu(agpt->my_lba)) {
error_found++;
fprintf(stderr,
"GPT:Primary header alternate_lba != Alt. header my_lba\n");
#ifdef DEBUG
fprintf(stderr, "GPT:%" PRIx64 " != %" PRIx64 "\n",
__le64_to_cpu(pgpt->alternate_lba),
__le64_to_cpu(agpt->my_lba));
#endif
}
if (__le64_to_cpu(pgpt->first_usable_lba) !=
__le64_to_cpu(agpt->first_usable_lba)) {
error_found++;
fprintf(stderr, "GPT:first_usable_lbas don't match.\n");
#ifdef DEBUG
fprintf(stderr, "GPT:%" PRIx64 " != %" PRIx64 "\n",
__le64_to_cpu(pgpt->first_usable_lba),
__le64_to_cpu(agpt->first_usable_lba));
#endif
}
if (__le64_to_cpu(pgpt->last_usable_lba) !=
__le64_to_cpu(agpt->last_usable_lba)) {
error_found++;
fprintf(stderr, "GPT:last_usable_lbas don't match.\n");
#ifdef DEBUG
fprintf(stderr, "GPT:%" PRIx64 " != %" PRIx64 "\n",
__le64_to_cpu(pgpt->last_usable_lba),
__le64_to_cpu(agpt->last_usable_lba));
#endif
}
if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
error_found++;
fprintf(stderr, "GPT:disk_guids don't match.\n");
}
if (__le32_to_cpu(pgpt->num_partition_entries) !=
__le32_to_cpu(agpt->num_partition_entries)) {
error_found++;
fprintf(stderr, "GPT:num_partition_entries don't match: "
"0x%x != 0x%x\n",
__le32_to_cpu(pgpt->num_partition_entries),
__le32_to_cpu(agpt->num_partition_entries));
}
if (__le32_to_cpu(pgpt->sizeof_partition_entry) !=
__le32_to_cpu(agpt->sizeof_partition_entry)) {
error_found++;
fprintf(stderr,
"GPT:sizeof_partition_entry values don't match: "
"0x%x != 0x%x\n",
__le32_to_cpu(pgpt->sizeof_partition_entry),
__le32_to_cpu(agpt->sizeof_partition_entry));
}
if (__le32_to_cpu(pgpt->partition_entry_array_crc32) !=
__le32_to_cpu(agpt->partition_entry_array_crc32)) {
error_found++;
fprintf(stderr,
"GPT:partition_entry_array_crc32 values don't match: "
"0x%x != 0x%x\n",
__le32_to_cpu(pgpt->partition_entry_array_crc32),
__le32_to_cpu(agpt->partition_entry_array_crc32));
}
if (__le64_to_cpu(pgpt->alternate_lba) != lastlba) {
error_found++;
fprintf(stderr,
"GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
#ifdef DEBUG
fprintf(stderr, "GPT:%" PRIx64 " != %" PRIx64 "\n",
__le64_to_cpu(pgpt->alternate_lba), lastlba);
#endif
}
if (__le64_to_cpu(agpt->my_lba) != lastlba) {
error_found++;
fprintf(stderr,
"GPT:Alternate GPT header not at the end of the disk.\n");
#ifdef DEBUG
fprintf(stderr, "GPT:%" PRIx64 " != %" PRIx64 "\n",
__le64_to_cpu(agpt->my_lba), lastlba);
#endif
}
if (error_found)
fprintf(stderr,
"GPT: Use GNU Parted to correct GPT errors.\n");
return;
}
/**
* find_valid_gpt() - Search disk for valid GPT headers and PTEs
* @fd is an open file descriptor to the whole disk
* @gpt is a GPT header ptr, filled on return.
* @ptes is a PTEs ptr, filled on return.
* Description: Returns 1 if valid, 0 on error.
* If valid, returns pointers to newly allocated GPT header and PTEs.
* Validity depends on finding either the Primary GPT header and PTEs valid,
* or the Alternate GPT header and PTEs valid, and the PMBR valid.
*/
static int
find_valid_gpt(int fd, gpt_header ** gpt, gpt_entry ** ptes)
{
int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
gpt_header *pgpt = NULL, *agpt = NULL;
gpt_entry *pptes = NULL, *aptes = NULL;
legacy_mbr *legacymbr = NULL;
uint64_t lastlba;
if (!gpt || !ptes)
return 0;
if (!(lastlba = last_lba(fd)))
return 0;
good_pgpt = is_gpt_valid(fd, GPT_PRIMARY_PARTITION_TABLE_LBA,
&pgpt, &pptes);
if (good_pgpt) {
good_agpt = is_gpt_valid(fd,
__le64_to_cpu(pgpt->alternate_lba),
&agpt, &aptes);
if (!good_agpt) {
good_agpt = is_gpt_valid(fd, lastlba,
&agpt, &aptes);
}
}
else {
good_agpt = is_gpt_valid(fd, lastlba,
&agpt, &aptes);
}
/* The obviously unsuccessful case */
if (!good_pgpt && !good_agpt) {
goto fail;
}
/* This will be added to the EFI Spec. per Intel after v1.02. */
legacymbr = malloc(sizeof (*legacymbr));
if (legacymbr) {
memset(legacymbr, 0, sizeof (*legacymbr));
read_lba(fd, 0, (uint8_t *) legacymbr,
sizeof (*legacymbr));
good_pmbr = is_pmbr_valid(legacymbr);
free(legacymbr);
legacymbr=NULL;
}
/* Failure due to bad PMBR */
if ((good_pgpt || good_agpt) && !good_pmbr && !force_gpt) {
fprintf(stderr,
" Warning: Disk has a valid GPT signature "
"but invalid PMBR.\n"
" Assuming this disk is *not* a GPT disk anymore.\n"
" Use gpt kernel option to override. "
"Use GNU Parted to correct disk.\n");
goto fail;
}
/* Would fail due to bad PMBR, but force GPT anyhow */
if ((good_pgpt || good_agpt) && !good_pmbr && force_gpt) {
fprintf(stderr,
" Warning: Disk has a valid GPT signature but "
"invalid PMBR.\n"
" Use GNU Parted to correct disk.\n"
" gpt option taken, disk treated as GPT.\n");
}
compare_gpts(pgpt, agpt, lastlba);
/* The good cases */
if (good_pgpt && (good_pmbr || force_gpt)) {
*gpt = pgpt;
*ptes = pptes;
if (agpt) { free(agpt); agpt = NULL; }
if (aptes) { free(aptes); aptes = NULL; }
if (!good_agpt) {
fprintf(stderr,
"Alternate GPT is invalid, "
"using primary GPT.\n");
}
return 1;
}
else if (good_agpt && (good_pmbr || force_gpt)) {
*gpt = agpt;
*ptes = aptes;
if (pgpt) { free(pgpt); pgpt = NULL; }
if (pptes) { free(pptes); pptes = NULL; }
fprintf(stderr,
"Primary GPT is invalid, using alternate GPT.\n");
return 1;
}
fail:
if (pgpt) { free(pgpt); pgpt=NULL; }
if (agpt) { free(agpt); agpt=NULL; }
if (pptes) { free(pptes); pptes=NULL; }
if (aptes) { free(aptes); aptes=NULL; }
*gpt = NULL;
*ptes = NULL;
return 0;
}
/**
* read_gpt_pt()
* @fd
* @all - slice with start/size of whole disk
*
* 0 if this isn't our partition table
* number of partitions if successful
*
*/
int
read_gpt_pt (int fd, __attribute__((unused)) struct slice all,
struct slice *sp, unsigned int ns)
{
gpt_header *gpt = NULL;
gpt_entry *ptes = NULL;
unsigned int i;
int n = 0;
int last_used_index=-1;
int sector_size_mul = get_sector_size(fd)/512;
if (!find_valid_gpt (fd, &gpt, &ptes) || !gpt || !ptes) {
if (gpt)
free (gpt);
if (ptes)
free (ptes);
return 0;
}
for (i = 0; i < __le32_to_cpu(gpt->num_partition_entries) && i < ns; i++) {
if (!efi_guidcmp (NULL_GUID, ptes[i].partition_type_guid)) {
sp[n].start = 0;
sp[n].size = 0;
n++;
} else {
sp[n].start = sector_size_mul *
__le64_to_cpu(ptes[i].starting_lba);
sp[n].size = sector_size_mul *
(__le64_to_cpu(ptes[i].ending_lba) -
__le64_to_cpu(ptes[i].starting_lba) + 1);
last_used_index=n;
n++;
}
}
free (ptes);
free (gpt);
return last_used_index+1;
}