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zip_utils.c: factorize initial bytes and magic read+check

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This commit is contained in:
Hugues Delorme 2017-01-09 15:27:14 +01:00
parent f1a6bf764c
commit 3914e51863
2 changed files with 53 additions and 49 deletions
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100
src/gmio_core/internal/zip_utils.c
View File

@ -89,12 +89,6 @@ static size_t gmio_zip_write_returnhelper(
return written;
}
static bool gmio_zip_read_checkhelper(
struct gmio_stream* stream, size_t read, size_t expected)
{
return read == expected && !gmio_stream_error(stream);
}
/* Helper to facilitate return from gmio_zip_[read,write]_xxx() API functions */
static size_t gmio_zip_io_returnerr(size_t io_len, int error, int* ptr_error)
{
@ -103,6 +97,36 @@ static size_t gmio_zip_io_returnerr(size_t io_len, int error, int* ptr_error)
return io_len;
}
/* Helper to read and check a 32b uint from buffer */
static bool gmio_zip_readcheckmagic(
const uint8_t** ptr_buff, uint32_t expected_magic, int* ptr_error)
{
if (gmio_adv_decode_uint32_le(ptr_buff) != expected_magic) {
if (ptr_error != NULL)
*ptr_error = GMIO_ZIP_UTILS_ERROR_BAD_MAGIC;
return false;
}
return true;
}
/* Helper to read and check some bytes from buffer */
static bool gmio_zip_readcheckbytes(
struct gmio_stream* stream,
uint8_t* buff,
size_t expected_len,
size_t* ptr_read_len,
int* ptr_error)
{
*ptr_read_len = gmio_stream_read_bytes(stream, buff, expected_len);
const int error =
(*ptr_read_len == expected_len && !gmio_stream_error(stream)) ?
GMIO_ERROR_OK :
GMIO_ERROR_STREAM;
if (ptr_error != NULL)
*ptr_error = error;
return gmio_no_error(error);
}
/* ----------
* API functions
* ---------- */
@ -113,16 +137,13 @@ size_t gmio_zip_read_local_file_header(
int *ptr_error)
{
uint8_t bytes[GMIO_ZIP_SIZE_LOCAL_FILE_HEADER];
size_t read_len = 0;
if (!gmio_zip_readcheckbytes(stream, bytes, sizeof(bytes), &read_len, ptr_error))
return read_len;
const uint8_t* buff = bytes;
const size_t read_len = gmio_stream_read_bytes(stream, bytes, sizeof(bytes));
if (!gmio_zip_read_checkhelper(stream, read_len, sizeof(bytes)))
return gmio_zip_io_returnerr(read_len, GMIO_ERROR_STREAM, ptr_error);
if (gmio_adv_decode_uint32_le(&buff) != 0x04034b50) {
return gmio_zip_io_returnerr(
read_len, GMIO_ZIP_UTILS_ERROR_BAD_MAGIC, ptr_error);
}
if (!gmio_zip_readcheckmagic(&buff, 0x04034b50, ptr_error))
return read_len;
info->version_needed_to_extract = gmio_adv_decode_uint16_le(&buff);
info->general_purpose_flags = gmio_adv_decode_uint16_le(&buff);
info->compress_method = gmio_adv_decode_uint16_le(&buff);
@ -194,16 +215,11 @@ size_t gmio_zip_read_central_directory_header(
{
uint8_t bytes[GMIO_ZIP_SIZE_CENTRAL_DIRECTORY_HEADER];
const uint8_t* buff = bytes;
const size_t read_len = gmio_stream_read_bytes(stream, bytes, sizeof(bytes));
if (!gmio_zip_read_checkhelper(stream, read_len, sizeof(bytes)))
return gmio_zip_io_returnerr(read_len, GMIO_ERROR_STREAM, ptr_error);
if (gmio_adv_decode_uint32_le(&buff) != 0x02014b50) {
return gmio_zip_io_returnerr(
read_len, GMIO_ZIP_UTILS_ERROR_BAD_MAGIC, ptr_error);
}
size_t read_len = 0;
if (!gmio_zip_readcheckbytes(stream, bytes, sizeof(bytes), &read_len, ptr_error))
return read_len;
if (!gmio_zip_readcheckmagic(&buff, 0x02014b50, ptr_error))
return read_len;
info->version_made_by = gmio_adv_decode_uint16_le(&buff);
info->version_needed_to_extract = gmio_adv_decode_uint16_le(&buff);
info->general_purpose_flags = gmio_adv_decode_uint16_le(&buff);
@ -238,17 +254,11 @@ size_t gmio_zip_read_end_of_central_directory_record(
{
uint8_t bytes[GMIO_ZIP_SIZE_END_OF_CENTRAL_DIRECTORY_RECORD];
const uint8_t* buff = bytes;
const size_t read_len = gmio_stream_read_bytes(stream, bytes, sizeof(bytes));
if (!gmio_zip_read_checkhelper(stream, read_len, sizeof(bytes)))
return gmio_zip_io_returnerr(read_len, GMIO_ERROR_STREAM, ptr_error);
/* 4-bytes magic */
if (gmio_adv_decode_uint32_le(&buff) != 0x06054b50) {
return gmio_zip_io_returnerr(
read_len, GMIO_ZIP_UTILS_ERROR_BAD_MAGIC, ptr_error);
}
size_t read_len = 0;
if (!gmio_zip_readcheckbytes(stream, bytes, sizeof(bytes), &read_len, ptr_error))
return read_len;
if (!gmio_zip_readcheckmagic(&buff, 0x06054b50, ptr_error))
return read_len;
info->disk_nb = gmio_adv_decode_uint16_le(&buff);
info->disk_nb_with_start_of_central_dir = gmio_adv_decode_uint16_le(&buff);
info->total_entry_count_in_central_dir_on_disk =
@ -311,15 +321,12 @@ size_t gmio_zip_read_data_descriptor(
{
uint8_t bytes[GMIO_ZIP_SIZE_DATA_DESCRIPTOR];
const uint8_t* buff = bytes;
const size_t read_len = gmio_stream_read_bytes(stream, bytes, sizeof(bytes));
if (!gmio_zip_read_checkhelper(stream, read_len, sizeof(bytes)))
return gmio_zip_io_returnerr(read_len, GMIO_ERROR_STREAM, ptr_error);
size_t read_len = 0;
if (!gmio_zip_readcheckbytes(stream, bytes, sizeof(bytes), &read_len, ptr_error))
return read_len;
info->crc32 = gmio_adv_decode_uint32_le(&buff);
info->compressed_size = gmio_adv_decode_uint32_le(&buff);
info->uncompressed_size = gmio_adv_decode_uint32_le(&buff);
return gmio_zip_io_returnerr(read_len, GMIO_ERROR_OK, ptr_error);
}
@ -331,15 +338,12 @@ size_t gmio_zip64_read_data_descriptor(
#ifdef GMIO_HAVE_INT64_TYPE
uint8_t bytes[GMIO_ZIP64_SIZE_DATA_DESCRIPTOR];
const uint8_t* buff = bytes;
const size_t read_len = gmio_stream_read_bytes(stream, bytes, sizeof(bytes));
if (!gmio_zip_read_checkhelper(stream, read_len, sizeof(bytes)))
return gmio_zip_io_returnerr(read_len, GMIO_ERROR_STREAM, ptr_error);
size_t read_len = 0;
if (!gmio_zip_readcheckbytes(stream, bytes, sizeof(bytes), &read_len, ptr_error))
return read_len;
info->crc32 = gmio_adv_decode_uint32_le(&buff);
info->compressed_size = gmio_adv_decode_uint64_le(&buff);
info->uncompressed_size = gmio_adv_decode_uint64_le(&buff);
return gmio_zip_io_returnerr(read_len, GMIO_ERROR_OK, ptr_error);
#else
/* TODO: error code */

2
src/gmio_core/internal/zip_utils.h
View File

@ -246,7 +246,7 @@ struct gmio_zip_write_result {
size_t written_len;
};
enum { GMIO_ZIP_UTILS_ERROR_TAG = 0x00AA0000 };
enum { GMIO_ZIP_UTILS_ERROR_TAG = 0xAA000000 };
enum gmio_zip_utils_error {
GMIO_ZIP_UTILS_ERROR_BAD_MAGIC = GMIO_ZIP_UTILS_ERROR_TAG + 0x01
};