gpt: part: Definition and declaration of GPT verification functions

This commit provides definition and declaration of GPT verification
functions - namely gpt_verify_headers() and gpt_verify_partitions().
The former is used to only check CRC32 of GPT's header and PTEs.
The latter examines each partition entry and compare attributes such as:
name, start offset and size with ones provided at '$partitions' env
variable.

Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Przemyslaw Marczak <p.marczak@samsung.com>
This commit is contained in:
Lukasz Majewski 2015-11-20 08:06:16 +01:00 committed by Tom Rini
parent 74f889b039
commit cef68bf904
2 changed files with 145 additions and 0 deletions

View File

@ -578,6 +578,116 @@ err:
return ret;
}
static void gpt_convert_efi_name_to_char(char *s, efi_char16_t *es, int n)
{
char *ess = (char *)es;
int i, j;
memset(s, '\0', n);
for (i = 0, j = 0; j < n; i += 2, j++) {
s[j] = ess[i];
if (!ess[i])
return;
}
}
int gpt_verify_headers(block_dev_desc_t *dev_desc, gpt_header *gpt_head,
gpt_entry **gpt_pte)
{
/*
* This function validates AND
* fills in the GPT header and PTE
*/
if (is_gpt_valid(dev_desc,
GPT_PRIMARY_PARTITION_TABLE_LBA,
gpt_head, gpt_pte) != 1) {
printf("%s: *** ERROR: Invalid GPT ***\n",
__func__);
return -1;
}
if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
gpt_head, gpt_pte) != 1) {
printf("%s: *** ERROR: Invalid Backup GPT ***\n",
__func__);
return -1;
}
return 0;
}
int gpt_verify_partitions(block_dev_desc_t *dev_desc,
disk_partition_t *partitions, int parts,
gpt_header *gpt_head, gpt_entry **gpt_pte)
{
char efi_str[PARTNAME_SZ + 1];
u64 gpt_part_size;
gpt_entry *gpt_e;
int ret, i;
ret = gpt_verify_headers(dev_desc, gpt_head, gpt_pte);
if (ret)
return ret;
gpt_e = *gpt_pte;
for (i = 0; i < parts; i++) {
if (i == gpt_head->num_partition_entries) {
error("More partitions than allowed!\n");
return -1;
}
/* Check if GPT and ENV partition names match */
gpt_convert_efi_name_to_char(efi_str, gpt_e[i].partition_name,
PARTNAME_SZ + 1);
debug("%s: part: %2d name - GPT: %16s, ENV: %16s ",
__func__, i, efi_str, partitions[i].name);
if (strncmp(efi_str, (char *)partitions[i].name,
sizeof(partitions->name))) {
error("Partition name: %s does not match %s!\n",
efi_str, (char *)partitions[i].name);
return -1;
}
/* Check if GPT and ENV sizes match */
gpt_part_size = le64_to_cpu(gpt_e[i].ending_lba) -
le64_to_cpu(gpt_e[i].starting_lba) + 1;
debug("size(LBA) - GPT: %8llu, ENV: %8llu ",
gpt_part_size, (u64) partitions[i].size);
if (le64_to_cpu(gpt_part_size) != partitions[i].size) {
error("Partition %s size: %llu does not match %llu!\n",
efi_str, gpt_part_size, (u64) partitions[i].size);
return -1;
}
/*
* Start address is optional - check only if provided
* in '$partition' variable
*/
if (!partitions[i].start) {
debug("\n");
continue;
}
/* Check if GPT and ENV start LBAs match */
debug("start LBA - GPT: %8llu, ENV: %8llu\n",
le64_to_cpu(gpt_e[i].starting_lba),
(u64) partitions[i].start);
if (le64_to_cpu(gpt_e[i].starting_lba) != partitions[i].start) {
error("Partition %s start: %llu does not match %llu!\n",
efi_str, le64_to_cpu(gpt_e[i].starting_lba),
(u64) partitions[i].start);
return -1;
}
}
return 0;
}
int is_valid_gpt_buf(block_dev_desc_t *dev_desc, void *buf)
{
gpt_header *gpt_h;

View File

@ -267,6 +267,41 @@ int is_valid_gpt_buf(block_dev_desc_t *dev_desc, void *buf);
* @return - '0' on success, otherwise error
*/
int write_mbr_and_gpt_partitions(block_dev_desc_t *dev_desc, void *buf);
/**
* gpt_verify_headers() - Function to read and CRC32 check of the GPT's header
* and partition table entries (PTE)
*
* As a side effect if sets gpt_head and gpt_pte so they point to GPT data.
*
* @param dev_desc - block device descriptor
* @param gpt_head - pointer to GPT header data read from medium
* @param gpt_pte - pointer to GPT partition table enties read from medium
*
* @return - '0' on success, otherwise error
*/
int gpt_verify_headers(block_dev_desc_t *dev_desc, gpt_header *gpt_head,
gpt_entry **gpt_pte);
/**
* gpt_verify_partitions() - Function to check if partitions' name, start and
* size correspond to '$partitions' env variable
*
* This function checks if on medium stored GPT data is in sync with information
* provided in '$partitions' environment variable. Specificially, name, start
* and size of the partition is checked.
*
* @param dev_desc - block device descriptor
* @param partitions - partition data read from '$partitions' env variable
* @param parts - number of partitions read from '$partitions' env variable
* @param gpt_head - pointer to GPT header data read from medium
* @param gpt_pte - pointer to GPT partition table enties read from medium
*
* @return - '0' on success, otherwise error
*/
int gpt_verify_partitions(block_dev_desc_t *dev_desc,
disk_partition_t *partitions, int parts,
gpt_header *gpt_head, gpt_entry **gpt_pte);
#endif
#endif /* _PART_H */