qftplib.cpp

See Appendix B for a description of the programs included on this companion disk. RESOURCE.WRI iden

    if (nCharRecv == 0)
    	{
    		_lclose(hFile);
				ReadFTPServerReply(hControlSocket);
    	}
 		
		return(nCharRecv);
	}

extern "C" void _export FAR PASCAL ExtractFileName(LPSTR lpPathString, 
			LPSTR lpszFileName)
	{
		LPSTR lp;									// General purpose pointer
		UINT i;										// General purpose index
		UINT iExtLength = 0;			// Length of file extension (following the dash)

		// Find the last forward slash (assume UNIX/NT directory conventions)		
		if (lp = _fstrrchr(lpPathString, '/'))
			lp++;
		else
			lp = lpPathString;
			
		// Loop while the length of the name is less than 8 characters 
		// (a valid DOS length), the character is not a dot and the 
		// pointer is valid
		for (i = 0; i < 8 && *lp != '.' && lp; i++)
			*(lpszFileName+i) = *(lp++);
				    
		// Add a dot to mark the start of the file extension
		*(lpszFileName+i) = '.';
		i++;
				
		// Find the last dot and use up to the next three characters for
		// the new file name.
		if (lp = _fstrrchr(lpPathString, '.'))
				for (iExtLength = 0; iExtLength < 3 && (*(lp)); iExtLength++)
						*(lpszFileName+(i++)) = *(++lp);
						
		// Null-terminate the new file name
		*(lpszFileName+i) = '\0';

		return;
	}

extern "C" HFILE _export FAR PASCAL  CreateTransferFile(LPSTR lpszFileName)
	{
		HFILE hFile;							// File handle for data file
    OFSTRUCT openFileBuff;		// The Windows open file data structure

		lpszFunctionName = "CreateTransferFile";
		
		if ((hFile = OpenFile(lpszFileName, (OFSTRUCT far *)&openFileBuff, 
					OF_CREATE)) == HFILE_ERROR)
			{
				_lclose(hFile);
				wsprintf(gszCommandBuffer,"Error creating file: %s\n", lpszFileName);
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, MB_OK|MB_ICONSTOP);
			}
		return(hFile);
	}
	
extern "C" SOCKET _export FAR PASCAL  ConnectFTPControlSocket(LPSTR lpszHost)
	{
		LPHOSTENT lpHostEnt;					// Internet host information structure
		SOCKADDR_IN sockAddr;					// Socket address structure
		LPSERVENT lpServEnt;					// Service information structure
		short nProtocolPort;					// Protocol port
		int nConnect;									// Socket connection results

		SOCKET hControlSocket = INVALID_SOCKET;	
		
		lpszFunctionName = "ConnectFTPControlSocket";

		if (!(lpHostEnt = gethostbyname(lpszHost)))
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer,
							"Error #%d while resolving address for %s", 
							iWinsockErr, lpszHost);
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(INVALID_SOCKET);
			}
			
		if ((hControlSocket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))
					== INVALID_SOCKET)
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer,
							"Error #%d occurred while creating socket!!", 
							iWinsockErr);
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(INVALID_SOCKET);
			}
						
		lpServEnt = getservbyname("ftp", DEFAULT_PROTOCOL);
						
		if (lpServEnt == NULL)
			nProtocolPort = htons(IPPORT_FTP);	
		else
			nProtocolPort = lpServEnt->s_port;

		// Define the socket address	
		sockAddr.sin_family = AF_INET;		
		sockAddr.sin_port = nProtocolPort;
		sockAddr.sin_addr = *((LPIN_ADDR)*lpHostEnt->h_addr_list);
						
		// Connect the socket
		if( nConnect = connect(hControlSocket, (LPSOCKADDR)&sockAddr, 
					sizeof(sockAddr)))
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer,
							"Error #%d occurred while connecting socket!!", 
							iWinsockErr);
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(INVALID_SOCKET);
			}

		// Make the control socket non-blocking before returning.
		IsReadyToRead(hControlSocket);
			
		if (ReadFTPServerReply(hControlSocket) >= 400)
			return(INVALID_SOCKET);
		else
			return(hControlSocket);
	}

extern "C" SOCKET FAR PASCAL RequestDataConnection(SOCKET hControlSocket, SOCKET hListenSocket)
	{
		SOCKADDR_IN sockAddr;					// Socket address structure
    int iLength;									// Length of the address structure
    UINT nLocalPort;							// Local port for listening
		UINT nReplyCode;							// FTP server reply code

		lpszFunctionName = "RequestDataConnection";

    // Get the address for the hListenSocket
		iLength = sizeof(sockAddr);
		if (getsockname(hListenSocket, (LPSOCKADDR)&sockAddr, 
					&iLength) == SOCKET_ERROR)
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer,
							"Error #%d occurred while getting listen socket name!!", 
							iWinsockErr);
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(INVALID_SOCKET);
			}

		// Extract the local port from the hListenSocket
		nLocalPort = sockAddr.sin_port;
								
		// Now, reuse the socket address structure to 
		// get the IP address from the control socket.
		if (getsockname(hControlSocket, (LPSOCKADDR)&sockAddr, 
					&iLength) == SOCKET_ERROR)
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer,
							"Error #%d occurred while getting control socket name!!", 
							iWinsockErr);
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(INVALID_SOCKET);
			}
					
		// Format the PORT command with the correct numbers.
		wsprintf(gszCommandBuffer, "PORT %d,%d,%d,%d,%d,%d\r\n", 
					sockAddr.sin_addr.S_un.S_un_b.s_b1, 
					sockAddr.sin_addr.S_un.S_un_b.s_b2,
					sockAddr.sin_addr.S_un.S_un_b.s_b3,
					sockAddr.sin_addr.S_un.S_un_b.s_b4,
					// Remember, the port is in network byte order. The FTP server
					// expects to see the high-order byte from the port (in terms of 
					// the network byte order) first. As such, from a PC, (which uses
					// little endian byte order) the program must transmit the low-order 
					// byte first and then the high-order. (If this is confusing, see the
					// "Internet Programming" chapter entitled "Time and the Network
					// Byte Order".
					nLocalPort & 0xFF,	
					nLocalPort >> 8);
																
		// Tell the server which port to use for data.
		if (nReplyCode = SendFTPCommand(hControlSocket, gszCommandBuffer)
					!= 200)
			{
				wsprintf(gszCommandBuffer, 
							"Error %d from PORT command to server!", 
							nReplyCode);
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(INVALID_SOCKET);
			}
		else
			return(hListenSocket);
	}
	
extern "C" SOCKET _export FAR PASCAL  CreateListenSocket(SOCKET hControlSocket)
	{
		SOCKADDR_IN sockAddr;					// Socket address structure
		SOCKET hListenSocket;					// Handle for the listener socket
		
		lpszFunctionName = "CreateListenSocket";

		if ((hListenSocket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) 
					== INVALID_SOCKET)
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer,
							"Error #%d occurred while creating socket!!", 
							iWinsockErr);
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(INVALID_SOCKET);
			}
		// Let the system assign a socket address	
		sockAddr.sin_family = AF_INET;		
		sockAddr.sin_port = htons(0);		// htons() is just a reminder.
		sockAddr.sin_addr.s_addr = INADDR_ANY;
						
		// Bind the socket
		if (bind(hListenSocket, (LPSOCKADDR)&sockAddr, sizeof(sockAddr)))
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer,
							"Error #%d occurred while binding socket!!", 
							iWinsockErr);
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(INVALID_SOCKET);
			}

		// Listen for the FTP server connection
		if (listen(hListenSocket, QUEUE_SIZE))	
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer, 
							"Error %d on listen socket!!", 
							iWinsockErr);   
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(INVALID_SOCKET);
			}
		
		// Ask the server to connect to the port monitored by the listener socket
		return(RequestDataConnection(hControlSocket, hListenSocket));
	}
		
extern "C" SOCKET _export FAR PASCAL  AcceptDataConnection(SOCKET hListenSocket)
	{
		SOCKET hDataSocket;				// Handle for socket that receives data
		SOCKADDR_IN sockAddr;			// Socket address structure
		int iAddrLength;					// The length of the socket address
	
		lpszFunctionName = "AcceptDataConnection";

		hDataSocket = accept(hListenSocket, (LPSOCKADDR)&sockAddr, 
				&iAddrLength); 
				
		// Close the listener socket since it is no longer needed
		closesocket(hListenSocket);
		
		if (hDataSocket == INVALID_SOCKET)
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer, 
							"Error %d while accepting a data socket connection!!", 
							iWinsockErr);   
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(INVALID_SOCKET);
			}
		else
			{
				// Make the data channel non-blocking before returning
				IsReadyToRead(hDataSocket);
				return(hDataSocket);
			}
	}

extern "C" BOOL _export FAR PASCAL  LoadWinsock(VOID)
	{
		WSADATA wsaData;							// Winsock implementation details

		if (WSAStartup(WINSOCK_VERSION, &wsaData))
			{
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, "Could not load Windows Sockets DLL.", 
							PROG_NAME, MB_OK|MB_ICONSTOP);
				return(FALSE);
			}
		else
			return(TRUE);
	}
	
extern "C" BOOL _export FAR PASCAL  CloseWinsock(VOID)
	{
		if (WSACleanup())
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer, 
							"WSACleanup() caused error# %d", 
							iWinsockErr);   
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, PROG_NAME, 
							MB_OK|MB_ICONSTOP);
				return(FALSE);
			}
		else
			return(TRUE);
	}
	
int _export FAR PASCAL LibMain(HANDLE hInstance, WORD wDataSeg,
			WORD wHeapSize, LPSTR lpszCmdParam)
	{
		if (wHeapSize > 0)	// Heap size defined in the DEF file. 
			UnlockData(0);		// Unlocks the current data segment. 
			
		return(1);
	}

int _export FAR PASCAL WEP(int nParam)
	{
		return(1);
	}