/** \internal
*
* Reset the meta and name structures.
* @param a_fs_file File to reset
*/
void
tsk_fs_file_reset(TSK_FS_FILE * a_fs_file)
{
if (a_fs_file->meta)
tsk_fs_meta_reset(a_fs_file->meta);
if (a_fs_file->name)
tsk_fs_name_reset(a_fs_file->name);
}
/**
* \internal
* Searches an exFAT file system for its volume label directory entry, which
* should be in the root directory of the file system. If the entry is found,
* its metadata is copied into the TSK_FS_META object of a TSK_FS_FILE object.
*
* @param [in] a_fatfs Generic FAT file system info structure.
* @param [out] a_fatfs Generic file system file structure.
* @return 0 on success, 1 otherwise, per TSK convention.
*/
static uint8_t
exfatfs_find_volume_label_dentry(FATFS_INFO *a_fatfs, TSK_FS_FILE *a_fs_file)
{
const char *func_name = "exfatfs_find_volume_label_dentry";
TSK_FS_INFO *fs = (TSK_FS_INFO *)a_fatfs;
TSK_DADDR_T current_sector = 0;
TSK_DADDR_T last_sector_of_data_area = 0;
char *sector_buf = NULL;
ssize_t bytes_read = 0;
TSK_INUM_T current_inum = 0;
FATFS_DENTRY *dentry = NULL;
uint64_t i = 0;
assert(a_fatfs != NULL);
assert(a_fs_file != NULL);
tsk_error_reset();
if (fatfs_ptr_arg_is_null(a_fatfs, "a_fatfs", func_name) ||
fatfs_ptr_arg_is_null(a_fs_file, "a_fs_file", func_name)) {
return FATFS_FAIL;
}
/* Allocate or reset the TSK_FS_META object. */
if (a_fs_file->meta == NULL) {
if ((a_fs_file->meta =
tsk_fs_meta_alloc(FATFS_FILE_CONTENT_LEN)) == NULL) {
return FATFS_FAIL;
}
}
else {
tsk_fs_meta_reset(a_fs_file->meta);
}
/* Allocate a buffer for reading in sector-size chunks of the image. */
if ((sector_buf = (char*)tsk_malloc(a_fatfs->ssize)) == NULL) {
return FATFS_FAIL;
}
current_sector = a_fatfs->rootsect;
last_sector_of_data_area = a_fatfs->firstdatasect + (a_fatfs->clustcnt * a_fatfs->csize) - 1;
while (current_sector < last_sector_of_data_area) {
int8_t sector_is_alloc = 0;
/* Read in a sector from the root directory. The volume label
* directory entry will probably be near the beginning of the
* directory, probably in the first sector. */
bytes_read = tsk_fs_read_block(fs, current_sector, sector_buf, a_fatfs->ssize);
if (bytes_read != a_fatfs->ssize) {
if (bytes_read >= 0) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_READ);
}
tsk_error_set_errstr2("%s: error reading sector: %" PRIuDADDR, func_name, current_sector);
free(sector_buf);
return FATFS_FAIL;
}
/* Get the allocation status of the sector (yes, it should be allocated). */
sector_is_alloc = fatfs_is_sectalloc(a_fatfs, current_sector);
if (sector_is_alloc == -1) {
return FATFS_FAIL;
}
/* Get the inode address of the first directory entry of the sector. */
current_inum = FATFS_SECT_2_INODE(a_fatfs, current_sector);
/* Loop through the putative directory entries in the sector,
* until the volume label entry is found. */
for (i = 0; i < a_fatfs->ssize; i += sizeof(FATFS_DENTRY)) {
dentry = (FATFS_DENTRY*)&(sector_buf[i]);
/* The type of the directory entry is encoded in the first byte
* of the entry. See EXFATFS_DIR_ENTRY_TYPE_ENUM. */
if (exfatfs_get_enum_from_type(dentry->data[0]) == EXFATFS_DIR_ENTRY_TYPE_VOLUME_LABEL) {
if (!exfatfs_is_vol_label_dentry(dentry, FATFS_DATA_UNIT_ALLOC_STATUS_UNKNOWN)) {
continue;
}
/* Found it, save it to the TSK_FS_META object of the
* TSK_FS_FILE object and exit. */
if (exfatfs_dinode_copy(a_fatfs, current_inum, dentry,
sector_is_alloc, a_fs_file) == TSK_OK) {
return FATFS_OK;
}
else {
return FATFS_FAIL;
}
}
}
}
free(sector_buf);
return FATFS_OK;
}
