/*
* Either initialize an input stream for files that exist on disk
* or open a handle through the Sleuthkit for file system files that
* have not been written to disk.
*/
void TskFileTsk::open()
{
if (m_isOpen)
return;
// Files inside of the file system
if (getTypeId() == TskImgDB::IMGDB_FILES_TYPE_FS)
{
// Otherwise, we open a handle to the file in ImageFile
m_handle = TskServices::Instance().getImageFile().openFile(m_id);
if (m_handle == -1)
{
LOGERROR(L"TskFileTsk::open - Error opening file.");
throw TskFileException("Error opening file");
}
}
else if (getTypeId() == TskImgDB::IMGDB_FILES_TYPE_UNUSED)
{
if (TskServices::Instance().getImgDB().getUnusedSector(getId(), m_unusedSectorsRecord) == -1) {
LOGERROR(L"TskFileTsk::open - Error opening file.");
throw TskFileException("Error opening file");
}
}
// CARVED and DERIVED
else if ((getTypeId() == TskImgDB::IMGDB_FILES_TYPE_CARVED) || (getTypeId() == TskImgDB::IMGDB_FILES_TYPE_DERIVED)) {
if (exists()) {
// Open our input stream if not already open
if (m_fileInStream == NULL)
{
m_fileInStream = new Poco::FileInputStream(m_file.path());
}
}
else {
std::wstringstream msg;
msg << L"TskFileTsk::open - Open failed because file id (" << m_id
<< ") does not exist on disk and is carved or derived.";
LOGERROR(msg.str());
throw TskFileException("Error opening file");
}
}
else
{
std::wstringstream msg;
msg << L"TskFileTsk::open - Open failed because file id (" << m_id
<< ") has unknown type (" << getTypeId() << ").";
LOGERROR(msg.str());
throw TskFileException("Error opening file");
}
m_offset = 0;
m_isOpen = true;
}
TSK_OFF_T TskFileTsk::seek(const TSK_OFF_T off, std::ios::seekdir origin)
{
if (!m_isOpen)
{
LOGERROR(L"TskFileTsk::seek : File not open.");
throw TskFileException("File not open.");
}
if (m_fileInStream != NULL)
{
// Clear all error flags before seeking since an earlier
// read may have set the eof flag.
m_fileInStream->clear();
m_fileInStream->seekg(off, origin);
return m_fileInStream->tellg();
}
else
{
if (origin == std::ios::beg)
{
if (off > getSize())
{
LOGERROR(L"TskFileTsk::seek - Attempt to seek beyond end of file.");
throw TskFileException("Attempt to seek beyond end of file.");
}
m_offset = off;
}
else if (origin == std::ios::end)
{
if (off > 0)
{
LOGERROR(L"TskFileTsk::seek - Offset must be a negative number when seeking from end of file.");
throw TskFileException("Seek from end requires negative offset.");
}
if (getSize() + off < 0)
{
LOGERROR(L"TskFileTsk::seek - Attempt to seek prior to start of file.");
throw TskFileException("Attempt to seek prior to start of file");
}
m_offset = getSize() + off;
}
else
{
if (m_offset + off > getSize())
{
LOGERROR(L"TskFileTsk::seek - Attempt to seek beyond end of file.");
throw TskFileException("Attempt to seek beyond end of file.");
}
if (m_offset + off < 0)
{
LOGERROR(L"TskFileTsk::seek - Attempt to seek prior to start of file.");
throw TskFileException("Attempt to seek prior to start of file.");
}
m_offset += off;
}
return m_offset;
}
}
TSK_OFF_T TskFileTsk::tell() const
{
if (!m_isOpen)
{
LOGERROR(L"TskFileTsk::tell : File not open.");
throw TskFileException("File not open.");
}
if (m_fileInStream != NULL)
return m_fileInStream->tellg();
else
return m_offset;
}
/* Create an uncompressed version of the file on the local file system.
* Note this will save zero-length files.
*/
int TskL01Extract::saveFile(const uint64_t fileId, const ArchivedFile &archivedFile)
{
try
{
// If a file with this id already exists we raise an error
std::auto_ptr<TskFile> pFile(TskServices::Instance().getFileManager().getFile(fileId));
if (pFile.get() != NULL && pFile->exists())
{
std::stringstream msg;
msg << "File id " << fileId << " already exists.";
throw TskFileException(msg.str());
}
// Create a blank file
Poco::Path destPath(TskUtilities::toUTF8(TskServices::Instance().getFileManager().getPath(fileId)));
Poco::File destFile(destPath);
destFile.createFile();
// Get data from archive
if (archivedFile.size > 0)
{
Poco::FileOutputStream fos(destFile.path(), std::ios::binary);
uint64_t chunkSize = ExtractChunkSize;
if (archivedFile.size < ExtractChunkSize)
{
chunkSize = archivedFile.size;
}
Poco::SharedPtr<char, Poco::ReferenceCounter, ArrayReleasePolicy<char> > dataBuf(new char[chunkSize]);
uint64_t accum = 0;
ewf::libewf_error_t *ewfError = NULL;
// Read and save data in chunks so that we only put <= ExtractChunkSize bytes on the heap at a time
while (accum < archivedFile.size)
{
ssize_t bytesRead = ewf::libewf_file_entry_read_buffer(archivedFile.entry, dataBuf, chunkSize, &ewfError);
if (bytesRead == -1)
{
std::stringstream logMessage;
char errorString[512];
errorString[0] = '\0';
ewf::libewf_error_backtrace_sprint(ewfError, errorString, 512);
logMessage << "TskL01Extract::saveFile - Error : " << errorString << std::endl;
LOGERROR(logMessage.str());
return -1;
}
fos.write(dataBuf, bytesRead);
accum += bytesRead;
}
fos.close();
}
return 0;
}
catch (Poco::Exception& ex)
{
std::wstringstream msg;
msg << L"TskL01Extract::saveFile - Error saving file from stream : " << ex.displayText().c_str();
LOGERROR(msg.str());
return -2;
}
}
