Resolves a regression from commit b23816ab9626 where efibootguard would
skip config file probing for an entire device upon encountering a
partition with an indeterminable FAT bit size.
Additionally, simplified the implementation and added documentation for
clarity.
Fixes: b23816ab9626 ("fix: correctly calculate FAT bit size based on cluster
count")
Reported-by: Felix Moessbauer <[email protected]>
Signed-off-by: Michael Adler <[email protected]>
---
tools/ebgpart.c | 69 ++++++++++++++++++++++++++++---------------------
1 file changed, 39 insertions(+), 30 deletions(-)
diff --git a/tools/ebgpart.c b/tools/ebgpart.c
index fc754df..9a9e179 100644
--- a/tools/ebgpart.c
+++ b/tools/ebgpart.c
@@ -44,7 +44,7 @@ static void add_block_dev(PedDevice *dev)
d->next = dev;
}
-static char *GUID_to_str(uint8_t *g)
+static char *GUID_to_str(const uint8_t *g)
{
(void)snprintf(buffer, 37,
"%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-"
@@ -73,26 +73,35 @@ static char *type_to_name(char t)
return "not supported";
}
-static bool check_GPT_FAT_entry(int fd, struct EFIpartitionentry *e,
- PedFileSystemType *pfst, uint32_t i)
+/**
+ * @brief Determines the FAT bit size of a disk or partition.
+ *
+ * @param fd File descriptor to inspect.
+ * @param e A pointer to the EFI partition entry.
+ * @param fat_size A pointer where the detected FAT bit size will be stored.
+ *
+ * @return 0 if the FAT bit size is successfully determined and stored in
+ * `fat_size`; otherwise, returns a non-zero error code.
+ */
+static int check_GPT_FAT_entry(int fd, const struct EFIpartitionentry *e,
+ int *fat_size)
{
char *guid_str = GUID_to_str(e->type_GUID);
if (strcmp(GPT_PARTITION_GUID_FAT_NTFS, guid_str) != 0 &&
strcmp(GPT_PARTITION_GUID_ESP, guid_str) != 0) {
- if (asprintf(&pfst->name, "%s", "not supported") == -1) {
- goto error_asprintf;
- }
VERBOSE(stderr, "GPT entry has unsupported GUID: %s\n",
guid_str);
- return true;
+ *fat_size = 0;
+ return 0;
}
- VERBOSE(stdout, "GPT Partition #%u is FAT/NTFS.\n", i);
+ VERBOSE(stdout, "GPT Partition has a FAT/NTFS GUID\n");
+
/* Save current file offset */
off64_t curr = lseek64(fd, 0, SEEK_CUR);
if (curr == -1) {
VERBOSE(stderr, "Error getting current seek position: %s\n",
strerror(errno));
- return false;
+ return -1;
}
/* seek to partition start */
@@ -100,7 +109,7 @@ static bool check_GPT_FAT_entry(int fd, struct
EFIpartitionentry *e,
if (lseek64(fd, offset_start, SEEK_SET) == -1) {
VERBOSE(stderr, "Error seeking to partition start: %s\n",
strerror(errno));
- return false;
+ return -1;
}
/* read FAT header */
@@ -108,32 +117,17 @@ static bool check_GPT_FAT_entry(int fd, struct
EFIpartitionentry *e,
if (read(fd, &header, sizeof(header)) != sizeof(header)) {
VERBOSE(stderr, "Error reading FAT header: %s\n",
strerror(errno));
- return false;
+ return -1;
}
/* restore pos */
if (lseek64(fd, curr, SEEK_SET) == -1) {
VERBOSE(stderr, "Error restoring seek position (%s)",
strerror(errno));
- return false;
- }
-
- int fat_bits = determine_FAT_bits(&header);
- if (fat_bits <= 0) {
- /* not a FAT header */
- return false;
- }
- if (asprintf(&pfst->name, "fat%d", fat_bits) == -1) {
- VERBOSE(stderr,
- "Error in asprintf - possibly out of memory.\n");
- return false;
+ return -1;
}
- VERBOSE(stdout, "GPT Partition #%u is %s.\n", i, pfst->name);
- return true;
-
-error_asprintf:
- VERBOSE(stderr, "Error in asprintf - possibly out of memory.\n");
- return false;
+ *fat_size = determine_FAT_bits(&header);
+ return 0;
}
static void read_GPT_entries(int fd, uint64_t table_LBA, uint32_t num,
@@ -178,13 +172,28 @@ static void read_GPT_entries(int fd, uint64_t table_LBA,
uint32_t num,
tmpp->num = i + 1;
tmpp->fs_type = pfst;
- if (!check_GPT_FAT_entry(fd, &e, pfst, i)) {
+ int fat_size = 0;
+ if (check_GPT_FAT_entry(fd, &e, &fat_size)) {
+ VERBOSE(stderr,
+ "%u: error, skipping partitions on device\n",
+ i);
free(pfst->name);
free(pfst);
free(tmpp);
dev->part_list = NULL;
continue;
}
+ if (fat_size > 0) {
+ VERBOSE(stdout, "GPT Partition #%u is fat%d.\n", i,
+ fat_size);
+ if (asprintf(&pfst->name, "fat%d", fat_size) == -1) {
+ VERBOSE(stderr, "Error in asprintf - possibly "
+ "out of memory.\n");
+ return;
+ }
+ } else {
+ VERBOSE(stderr, "%u: not a FAT partition\n", i);
+ }
*list_end = tmpp;
list_end = &((*list_end)->next);
--
2.42.0
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