bool Packaging::ExtractTar(QTemporaryFile& tarFile, PackageData *packageData)
{
TarHeader tarHeader;
if (!tarFile.open())
{
Alerts::DisplayError(QString("Error opening temporary TAR archive:\n%1").arg(tarFile.fileName()));
return (false);
}
bool previousEmpty = false;
QProgressDialog progressDialog("Extracting files...", "Cancel", 0, tarFile.size());
progressDialog.setWindowModality(Qt::ApplicationModal);
progressDialog.setWindowTitle("Heimdall Frontend");
while (!tarFile.atEnd())
{
qint64 dataRead = tarFile.read(tarHeader.buffer, TarHeader::kBlockLength);
if (dataRead != TarHeader::kBlockLength)
{
progressDialog.close();
Alerts::DisplayError("Package's TAR archive is malformed.");
tarFile.close();
return (false);
}
progressDialog.setValue(tarFile.pos());
if (progressDialog.wasCanceled())
{
tarFile.close();
progressDialog.close();
return (false);
}
//bool ustarFormat = strcmp(tarHeader.fields.magic, ustarMagic) == 0;
bool empty = true;
for (int i = 0; i < TarHeader::kBlockLength; i++)
{
if (tarHeader.buffer[i] != 0)
{
empty = false;
break;
}
}
if (empty)
{
if (previousEmpty)
{
// Two empty blocks in a row means we've reached the end of the archive.
break;
}
}
else
{
int checksum = 0;
for (char *bufferIndex = tarHeader.buffer; bufferIndex < tarHeader.fields.checksum; bufferIndex++)
checksum += static_cast<unsigned char>(*bufferIndex);
checksum += 8 * ' ';
checksum += static_cast<unsigned char>(tarHeader.fields.typeFlag);
// Both the TAR and USTAR formats have terrible documentation, it's not clear if the following code is required.
/*if (ustarFormat)
{
for (char *bufferIndex = tarHeader.fields.linkName; bufferIndex < tarHeader.fields.prefix + 155; bufferIndex++)
checksum += static_cast<unsigned char>(*bufferIndex);
}*/
bool parsed = false;
// The size field is not always null terminated, so we must create a copy and null terminate it for parsing.
char fileSizeString[13];
memcpy(fileSizeString, tarHeader.fields.size, 12);
fileSizeString[12] = '\0';
qulonglong fileSize = QString(fileSizeString).toULongLong(&parsed, 8);
if (!parsed)
{
progressDialog.close();
Alerts::DisplayError("Tar header contained an invalid file size.");
tarFile.close();
return (false);
}
if (fileSize > 0 && tarHeader.fields.typeFlag == '0')
{
// We're working with a file.
QString filename = QString::fromUtf8(tarHeader.fields.name);
QTemporaryFile *outputFile = new QTemporaryFile("XXXXXX-" + filename);
packageData->GetFiles().append(outputFile);
if (!outputFile->open())
{
progressDialog.close();
Alerts::DisplayError(QString("Failed to open output file: \n%1").arg(outputFile->fileName()));
tarFile.close();
return (false);
}
qulonglong dataRemaining = fileSize;
char readBuffer[TarHeader::kBlockReadCount * TarHeader::kBlockLength];
// Copy the file contents from tarFile to outputFile
while (dataRemaining > 0)
{
qint64 fileDataToRead = (dataRemaining < TarHeader::kBlockReadCount * TarHeader::kBlockLength)
? dataRemaining : TarHeader::kBlockReadCount * TarHeader::kBlockLength;
qint64 dataRead = tarFile.read(readBuffer, fileDataToRead + (TarHeader::kBlockLength - fileDataToRead % TarHeader::kBlockLength) % TarHeader::kBlockLength);
if (dataRead < fileDataToRead || dataRead % TarHeader::kBlockLength != 0)
{
progressDialog.close();
Alerts::DisplayError("Unexpected read error whilst extracting package files.");
tarFile.close();
outputFile->close();
remove(outputFile->fileName().toStdString().c_str());
return (false);
}
outputFile->write(readBuffer, fileDataToRead);
dataRemaining -= fileDataToRead;
progressDialog.setValue(tarFile.pos());
if (progressDialog.wasCanceled())
{
tarFile.close();
outputFile->close();
remove(outputFile->fileName().toStdString().c_str());
progressDialog.close();
return (false);
}
}
outputFile->close();
}
else
{
progressDialog.close();
Alerts::DisplayError("Heimdall packages shouldn't contain links or directories.");
tarFile.close();
return (false);
}
}
previousEmpty = empty;
}
progressDialog.close();
tarFile.close();
return (true);
}
