FtpGetFile WinINEt never returns - c++

Question

I'm experiencing a curious problem (very strange, let me say hehe). During a FTP download of an EXE file (24 MB), if the connection is ever interrupted, it appears that the function FtpGetFile of the WinINEt library has a bug and it never returns. This causes that future file transfers fail (the connection is already opened).
Apparently, I found a workaround by increasing the timeout of the server transfers but I do not like it. I didn't found a similar problem by googling (maybe I introduced the wrong keywords).
I read some forums on the internet and it seems that everyone does not recommend using the FtpGetFile because it is buggy.
This appears in a network scenario that has a big lag (and not always) but in good conditions it disappears (downloads take place correctly and FtpGetFile returns always).
Here is how I use the function:
if( FtpGetFile(m_hFtpSession, strSourcePath.c_str(), strTargetPath.c_str(), 0, 0, FTP_TRANSFER_TYPE_BINARY, 0)==TRUE)
Can anyone confirm that? Should I refactor my code and look for an update?
Thank you

Answer 1

I found a way to download files without using FtpGetFile. I hope this code can help someone:
bool RetrieveFile(const string& strSource, const string& strTarget) {
/* The handle for the transfer */
HINTERNET hTransfer = NULL;
/*
* Set default error
*/
DWORD error = ERROR_SUCCESS;
if( !isConnected ) {
debug("%s(): ERROR not connected\n", __FUNCTION__);
return false;
}
/* Initiate access to a remote FTP connection */
hTransfer = FtpOpenFile(hFtpSession, strSource.c_str(), GENERIC_READ,
FTP_TRANSFER_TYPE_BINARY, 0);
if(hTransfer) {
std::ofstream myostream(strTarget.c_str(), std::ios::binary);
if ( myostream.is_open() ) {
static const DWORD SIZE = 1024;
BYTE data[SIZE];
DWORD size = 0;
do {
BOOL result = InternetReadFile(hTransfer, data, SIZE, &size);
if ( result == FALSE ) {
error = GetLastError();
Debug("InternetReadFile(): %lu\n", error);
}
myostream.write((const char*)data, size);
}
while ((error == ERROR_SUCCESS) && (size > 0));
// Close the stream
myostream.close();
}
else {
Debug("Could not open '%s'.\n", strTarget.c_str());
error = ERROR_FILE_NOT_FOUND; // Not necessarily not found, but it is to describe a file error which is different from ERROR_SUCCESS
}
// Close
const BOOL result = InternetCloseHandle(hTransfer);
if ( result == FALSE ) {
const DWORD error = GetLastError();
debug("InternetClose(): %lu\n", error);
}
/* Check error status of the process */
return (error == ERROR_SUCCESS);
}
DWORD dwInetError;
DWORD dwExtLength = 1000;
TCHAR *szExtErrMsg = NULL;
TCHAR errmsg[1000];
szExtErrMsg = errmsg;
int returned = InternetGetLastResponseInfo( &dwInetError, szExtErrMsg, &dwExtLength );
debug("dwInetError: %d Returned: %d\n", dwInetError, returned);
debug("Buffer: %s\n", szExtErrMsg);
debug("%s() : ERROR to get '%s' file (errorCode=%d)\n", __FUNCTION__, strSource.c_str(), GetLastError());
return false;
}