qftp2.cpp

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

#include <stdlib.h>								// Required for atoi()
#include "..\winsock.h"						// Winsock header file

#define PROG_NAME "Quick FTP Version 2"

#define HOST_NAME "NIC.DDN.MIL"		// FTP server host
#define PASSWORD "PASS guest\r\n"	// Password for FTP server host
#define WINSOCK_VERSION 0x0101		// Program requires Winsock version 1.1
#define DEFAULT_PROTOCOL 0				// No protocol specified, use default
#define NO_FLAGS 0								// No special flags specified
#define QUEUE_SIZE 1							// Size of connection queue for listen()
#define LINEFEED 0x0A							// Line-feed character

char gsServerReplyBuffer[2048];		// FTP server reply buffer
char gszCommandBuffer[100];				// Buffer used to format FTP commands
LPSTR lpszFunctionName;						// Pointer to function names

UINT GetReplyCode(LPSTR lpszServerReply)
	{
		UINT nCode;																		// Reply code as a number
		char c;																				// Temporary storage

		// lpszFunctionName = "GetReplyCode";

		c = *(lpszServerReply+3);											// Save the character
		*(lpszServerReply+3) = '\0';									// Terminate the code

		nCode = atoi((const char *)lpszServerReply);	// Convert code to number
		*(lpszServerReply+3) = c;											// Restore the character

		return(nCode);																// Return the reply code
	}	

UINT ReadFTPServerReply(SOCKET hControlChannel)
	{
		// Note that the function now uses a global receive buffer so 
		// in the future other program modules can access the full
		// text of the server's reply rather than just the
		// server's reply code (which this function returns.)
		
		int iBytesRead;						// Bytes read from the control channel
		int iBufferLength;				// Length of the server reply buffer
		int iEnd;									// Index into the server reply buffer
		int iSpaceRemaining;			// Space remaining in the buffer
		
		lpszFunctionName = "ReadFTPServerReply";

		iEnd = 0;
		iBufferLength = iSpaceRemaining = sizeof(gsServerReplyBuffer);
		do
			{
				iSpaceRemaining -= iEnd;
				iBytesRead = recv(hControlChannel, 
							(LPSTR)(gsServerReplyBuffer+iEnd), iSpaceRemaining, NO_FLAGS);
    			
    		iEnd+=iBytesRead;
    		
    		// Make sure CRLF was not the the last byte pair received. 
    		// Otherwise, recv() will wait forever for the next packet.
    		if (*(gsServerReplyBuffer+(iEnd-2)) == '\r'  && 
    					*(gsServerReplyBuffer+(iEnd-1)) == '\n')
    			break;
			}
		while (iBytesRead > 0 && iEnd < iBufferLength); 
		
    if (iBytesRead == SOCKET_ERROR)
  		{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer, "Error %d from the recv() function!!", 
							iWinsockErr);   
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
			  // Return 999 to indicate an error has occurred
				return(999);
			} 
					
		gsServerReplyBuffer[iEnd] = '\0';
		MessageBeep(MB_ICONINFORMATION);
    MessageBox(NULL, (LPSTR)gsServerReplyBuffer, lpszFunctionName,
          MB_OK|MB_ICONINFORMATION);
          
    // Extract the reply code from the server reply and return as an integer
		return(GetReplyCode(gsServerReplyBuffer));	            
	}	
	
UINT SendFTPCommand(SOCKET hControlChannel, LPSTR gszCommandBuffer)
	{
		lpszFunctionName = "SendFTPCommand";

		// Send the FTP command
		if ((send(hControlChannel, (LPSTR)gszCommandBuffer, 
					lstrlen(gszCommandBuffer), NO_FLAGS)) == SOCKET_ERROR)
			{
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer, "Error %d from the send() function!!", 
							iWinsockErr);   
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
			  // Return 999 to indicate an error has occurred
				return(999);
			} 
		
		// Read the server's reply and return the reply code as an integer
		return(ReadFTPServerReply(hControlChannel));	            
	}	
	
BOOL ReadDataChannel(SOCKET hDataSocket, LPSTR lpszFileName)
	{
		char sDataBuffer[4096];		// Data-storage buffer for the data channel
		int nBytesRecv;						// Bytes received from the data channel
		HFILE hFile;							// File handle for data file
    OFSTRUCT openFileBuff;		// The Windows open file data structure 
		LONG lData = 0L;					// Bytes received and written to the data file

		lpszFunctionName = "ReadDataChannel";

		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(FALSE);
			}
			
    do	// Ready read and write
    	{
    		nBytesRecv = recv(hDataSocket, (LPSTR)&sDataBuffer, 
    					sizeof(sDataBuffer), NO_FLAGS);
    					
    		lData += nBytesRecv;
    		if (nBytesRecv > 0 )
    			{
    				if (HFILE_ERROR == _lwrite (hFile, sDataBuffer, nBytesRecv))
    					{
								wsprintf(gszCommandBuffer,"Error writing file: %s\n", lpszFileName);
								MessageBeep(MB_ICONSTOP);
								MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
											MB_OK|MB_ICONSTOP);
	    					break;
    					}
		    	}
			}
		while (nBytesRecv > 0);
								
		// Close the file and check for error returns.
		_lclose(hFile);
		if (nBytesRecv == SOCKET_ERROR)
			{ 
				int iWinsockErr = WSAGetLastError();
				wsprintf(gszCommandBuffer,
							"Error #%d occurred receiving: %s\n", 
							iWinsockErr, lpszFileName);
				MessageBeep(MB_ICONSTOP);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONSTOP);
				return(FALSE);
			}
		else
			{
				wsprintf(gszCommandBuffer,"%lu bytes written to %s\n", lData, 
							lpszFileName);
				MessageBeep(MB_ICONINFORMATION);
				MessageBox(NULL, gszCommandBuffer, lpszFunctionName, 
							MB_OK|MB_ICONINFORMATION);
			}

		return(TRUE);
	}	

UINT AnonymousFTPLogIn(SOCKET hControlSocket)
	{
		int nReplyCode;									// FTP server reply code
    int iMsg;												// Index subscript for FTP commands
    
		lpszFunctionName = "AnonymousFTPLogIn";
		
    char	*LoginCommand[]	=	
    		{
    			"USER anonymous\r\n",
    			PASSWORD,
			    0
			  };
			  
    iMsg = 0;
    do
    	{
    		nReplyCode = SendFTPCommand(hControlSocket, 
    					(LPSTR)LoginCommand[iMsg]);
				iMsg++;
			} 
		while (LoginCommand[iMsg] && nReplyCode < 400);
		
		return(nReplyCode);
	}	

SOCKET 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;				// Control socket handle
		
		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;