static int _loki_write_loki_header(MbBiWriter *biw, MbFile *file,
const LokiHeader *lhdr)
{
LokiHeader dup = *lhdr;
size_t n;
int ret;
loki_fix_header_byte_order(&dup);
ret = mb_file_seek(file, LOKI_MAGIC_OFFSET, SEEK_SET, nullptr);
if (ret != MB_FILE_OK) {
mb_bi_writer_set_error(biw, mb_file_error(file),
"Failed to seek to Loki header offset: %s",
mb_file_error_string(file));
return ret == MB_FILE_FATAL ? MB_BI_FATAL : MB_BI_FAILED;
}
ret = mb_file_write_fully(file, &dup, sizeof(dup), &n);
if (ret != MB_FILE_OK) {
mb_bi_writer_set_error(biw, mb_file_error(file),
"Failed to write Loki header: %s",
mb_file_error_string(file));
return ret == MB_FILE_FATAL ? MB_BI_FATAL : MB_BI_FAILED;
} else if (n != sizeof(dup)) {
mb_bi_writer_set_error(biw, MB_BI_ERROR_FILE_FORMAT,
"Unexpected EOF when writing Loki header: %s",
mb_file_error_string(file));
return MB_BI_FAILED;
}
return MB_BI_OK;
}
/*!
* \brief Find and read Loki boot image header
*
* \note The integral fields in the header will be converted to the host's byte
* order.
*
* \pre The file position can be at any offset prior to calling this function.
*
* \post The file pointer position is undefined after this function returns.
* Use File::seek() to return to a known position.
*
* \param[in] reader Reader
* \param[in] file File handle
* \param[out] header_out Pointer to store header
* \param[out] offset_out Pointer to store header offset
*
* \return
* * Nothing if the header is found
* * A LokiError if the header is not found
* * A specified error code if any file operation fails
*/
oc::result<void> LokiFormatReader::find_loki_header(Reader &reader, File &file,
LokiHeader &header_out,
uint64_t &offset_out)
{
LokiHeader header;
auto seek_ret = file.seek(LOKI_MAGIC_OFFSET, SEEK_SET);
if (!seek_ret) {
if (file.is_fatal()) { reader.set_fatal(); }
return seek_ret.as_failure();
}
auto ret = file_read_exact(file, &header, sizeof(header));
if (!ret) {
if (ret.error() == FileError::UnexpectedEof) {
return LokiError::LokiHeaderTooSmall;
} else {
if (file.is_fatal()) { reader.set_fatal(); }
return ret.as_failure();
}
}
if (memcmp(header.magic, LOKI_MAGIC, LOKI_MAGIC_SIZE) != 0) {
return LokiError::InvalidLokiMagic;
}
loki_fix_header_byte_order(header);
header_out = header;
offset_out = LOKI_MAGIC_OFFSET;
return oc::success();
}
MB_BEGIN_C_DECLS
/*!
* \brief Find and read Loki boot image header
*
* \note The integral fields in the header will be converted to the host's byte
* order.
*
* \pre The file position can be at any offset prior to calling this function.
*
* \post The file pointer position is undefined after this function returns.
* Use mb_file_seek() to return to a known position.
*
* \param[in] bir MbBiReader
* \param[in] file MbFile handle
* \param[out] header_out Pointer to store header
* \param[out] offset_out Pointer to store header offset
*
* \return
* * #MB_BI_OK if the header is found
* * #MB_BI_WARN if the header is not found
* * #MB_BI_FAILED if any file operation fails non-fatally
* * #MB_BI_FATAL if any file operation fails fatally
*/
int find_loki_header(MbBiReader *bir, MbFile *file,
LokiHeader *header_out, uint64_t *offset_out)
{
LokiHeader header;
size_t n;
int ret;
ret = mb_file_seek(file, LOKI_MAGIC_OFFSET, SEEK_SET, nullptr);
if (ret < 0) {
mb_bi_reader_set_error(bir, mb_file_error(file),
"Loki magic not found: %s",
mb_file_error_string(file));
return ret == MB_FILE_FATAL ? MB_BI_FATAL : MB_BI_WARN;
}
ret = mb_file_read_fully(file, &header, sizeof(header), &n);
if (ret < 0) {
mb_bi_reader_set_error(bir, mb_file_error(file),
"Failed to read header: %s",
mb_file_error_string(file));
return ret == MB_FILE_FATAL ? MB_BI_FATAL : MB_BI_FAILED;
} else if (n != sizeof(header)) {
mb_bi_reader_set_error(bir, MB_BI_ERROR_FILE_FORMAT,
"Too small to be Loki image");
return MB_BI_WARN;
}
if (memcmp(header.magic, LOKI_MAGIC, LOKI_MAGIC_SIZE) != 0) {
mb_bi_reader_set_error(bir, MB_BI_ERROR_FILE_FORMAT,
"Invalid loki magic");
return MB_BI_WARN;
}
loki_fix_header_byte_order(&header);
*header_out = header;
*offset_out = LOKI_MAGIC_OFFSET;
return MB_BI_OK;
}
