nettrans.cpp

通过用SOCKET发包来实现PING命令

		printf("\n   Error   in   Binding   socket.");
		WSACleanup();
		return   -3; 
	};  
   
	if(::listen(listen_socket,5)!=0)  
	{
		printf("\n   Error   in   Listen.");   WSACleanup();
		return   -4;
	}  
	gListen_Socket=listen_socket;    
//	CreateThread(UserToProxyThread,NULL);       //启动侦听  
	UserToProxyThreadHandle = (HANDLE)_beginthreadex( NULL, 0, &UserToProxyThread, NULL, 0, &UserToProxyThreadID);

	return   1;  
}  
int   CloseServer()     //关闭服务  
{  
	closesocket(gListen_Socket);  
	WSACleanup();  
	return   1;  
}  
//分析接收到的字符，得到远程主机地址  
int   GetAddressAndPort(   char   *   str,   char   *address,   int   *   port)  
{  
	char   buf[BUFSIZE],   command[512],   proto[128] ;
	char *p;  
	unsigned int   j;  
  sscanf(str,"%s%s%s",command,buf,proto);  
  p=strstr(buf,HTTP);  
  //HTTP  
  if(p)  
  {  
  p+=strlen(HTTP);
  unsigned int i=0  ;
  for(i=0; i<strlen(p); i++ ) 
	   if(   *(p+i)=='/')
		   break;  
  *(p+i)=0;  
  strcpy(address,p);  
  p=strstr(str,HTTP);  
  for(unsigned int j=0; j< i+strlen(HTTP);j++)  
  *(p+j)=' ';     //去掉远程主机名:   GET   http://www.njust.edu.cn/   HTTP1.1     ==   >   GET   /   HTTP1.1  
  *port=80;             //缺省的   http   端口    
  }  
  else  
  {//FTP,   不支持,   下面的代码可以省略.  
    p=strstr(buf,FTP);  
    if(!p)   return   0;  
    p+=strlen(FTP);  
  for(unsigned int   i=0;i<   strlen(p);i++)  
  if(   *(p+i)=='/')   break;             //Get   The   Remote   Host  
  *(p+i)=0;  
  for(j=0;j<   strlen(p);j++)  
  if(*(p+j)==':')    
  {*port=atoi(p+j+1);         //Get   The   Port  
            *(p+j)=0;  
  }  
    else   *port=21;                                
   
  strcpy(address,p);  
  p=strstr(str,FTP);  
  for(j=0;j<   i+strlen(FTP);j++)  
  *(p+j)=' ';  
  }  
  return   1;    
  }  
   
  //   取到本地的数据，发往远程主机
//UINT   UserToProxyThread(void   *pParam)  
unsigned _stdcall UserToProxyThread(void *prarm)
{
    
    char   Buffer[BUFSIZE];  
    int     Len; 
	unsigned int UserToProxyThreadID;
	unsigned int ProxyToServerID;
    sockaddr_in   from;  
    SOCKET   msg_socket;  
    int   fromlen,retval;  
    SocketPair   SPair;  
    ProxyParam   ProxyP;  
    HANDLE   pChildThread;  
            fromlen=sizeof(from);  
    msg_socket=accept(gListen_Socket,(struct   sockaddr*)&from,&fromlen);  
      //AfxBeginThread(UserToProxyThread,pParam);   //启动另一侦听.
	_beginthreadex( NULL, 0, &UserToProxyThread, NULL, 0, &UserToProxyThreadID);
	  
	if(   msg_socket==INVALID_SOCKET)  
	{  
		printf(   "\nError     in   accept   "); 
		return   -5;
	}  
     
  //读客户的第一行数据  
   
    SPair.IsUser_ProxyClosed=FALSE;  
    SPair.IsProxy_ServerClosed=TRUE;  
    SPair.user_proxy=msg_socket;  
   
    retval=recv(SPair.user_proxy,Buffer,sizeof(Buffer),0);  
     
    if(retval==SOCKET_ERROR)  
  {   printf("\nError   Recv");    
              if(SPair.IsUser_ProxyClosed==FALSE)  
  {closesocket(SPair.user_proxy);  
    SPair.IsUser_ProxyClosed=TRUE;  
  }  
  }  
    if(retval==0)  
  {printf("Client   Close   connection\n");  
            if(SPair.IsUser_ProxyClosed==FALSE)  
  {closesocket(SPair.user_proxy);  
    SPair.IsUser_ProxyClosed=TRUE;  
  }  
  }  
    Len=retval;  
  #ifdef   _DEBUG  
   
    Buffer[Len]=0;  
    printf("\n   Received   %d   bytes,data[%s]from   client\n",retval,Buffer);  
  #endif  
    //  
    SPair.IsUser_ProxyClosed=FALSE;  
    SPair.IsProxy_ServerClosed=TRUE;  
    SPair.user_proxy=msg_socket;  
   
    ProxyP.pPair=&SPair;  
    ProxyP.User_SvrOK=CreateEvent(NULL,TRUE,FALSE,NULL);  
     
    GetAddressAndPort(   Buffer,ProxyP.Address,&ProxyP.Port);  
   
  //  pChildThread=AfxBeginThread(ProxyToServer,(LPVOID)&ProxyP); 
	pChildThread = (HANDLE)_beginthreadex( NULL, 0, &ProxyToServer, (LPVOID)&ProxyP, 0, &ProxyToServerID);

    ::WaitForSingleObject(ProxyP.User_SvrOK,60000);     //等待联结  
    ::CloseHandle(ProxyP.User_SvrOK);  
   
      while(SPair.IsProxy_ServerClosed   ==FALSE   &&   SPair.IsUser_ProxyClosed==FALSE)  
    {  
        retval=send(SPair.proxy_server,Buffer,Len,0);  
        if(retval==SOCKET_ERROR)  
  {   printf("\n   send()   failed:error%d\n",WSAGetLastError());  
            if(SPair.IsProxy_ServerClosed==FALSE)  
  {  
  closesocket(SPair.proxy_server);  
  SPair.IsProxy_ServerClosed=TRUE;  
  }  
      continue;  
  }  
          retval=recv(SPair.user_proxy,Buffer,sizeof(Buffer),0);  
     
  if(retval==SOCKET_ERROR)  
  {   printf("\nError   Recv");    
              if(SPair.IsUser_ProxyClosed==FALSE)  
  {closesocket(SPair.user_proxy);  
    SPair.IsUser_ProxyClosed=TRUE;  
  }  
              continue;  
  }  
  if(retval==0)  
  {
		printf("Client   Close   connection\n");  
		if(SPair.IsUser_ProxyClosed==FALSE) 
		{
		   closesocket(SPair.user_proxy);  
		   SPair.IsUser_ProxyClosed=TRUE; 
		}  
		break;  
  }  
  Len=retval;  
  #ifdef   _DEBUG  
  Buffer[Len]=0;  
    printf("\n   Received   %d   bytes,data[%s]from   client\n",retval,Buffer);  
  #endif  
   
      }   //End   While  
   
            if(SPair.IsProxy_ServerClosed==FALSE)  
  {  
  closesocket(SPair.proxy_server);  
  SPair.IsProxy_ServerClosed=TRUE;  
  }  
    if(SPair.IsUser_ProxyClosed==FALSE)  
  {closesocket(SPair.user_proxy);  
    SPair.IsUser_ProxyClosed=TRUE;  
  }  
 // ::WaitForSingleObject(pChildThread->m_hThread,20000);     //Should   check   the   return   value  
  return   0;  
  }  
   
  //   读取远程主机数据，并发往本地客户机  
unsigned _stdcall  ProxyToServer(LPVOID   pParam)
{
	ProxyParam   *   pPar=(ProxyParam*)pParam;
	char   Buffer[BUFSIZE];  
	char   *server_name=   "localhost"; 
	unsigned   short   port   ;  
	int   retval,Len;  
	unsigned   int   addr;  
	int   socket_type   ;  
	struct   sockaddr_in   server;  
	struct   hostent   *hp;  
	SOCKET     conn_socket;  
	
	socket_type   =   SOCK_STREAM; 
	server_name   =   pPar->Address; 
	port   =   pPar->Port;  
	if   (isalpha(server_name[0])) 
	{   
		/*   server   address   is   a   name    
		hp   =   gethostbyname(server_name);  
	}  
	else 
    { 
		/*   Convert   nnn.nnn   address   to   a   usable   one    
		addr   =   inet_addr(server_name);  
		hp   =   gethostbyaddr((char   *)&addr,4,AF_INET);  
	}  
	if   (hp   ==   NULL   )   
	{  
		fprintf(stderr,"Client:   Cannot   resolve   address   [%s]:   Error   %d\n",  
		server_name,WSAGetLastError());  
		::SetEvent(pPar->User_SvrOK);  
		return   0;  
	}   
  //   Copy   the   resolved   information   into   the   sockaddr_in   structure    
  memset(&server,0,sizeof(server));  
  memcpy(&(server.sin_addr),hp->h_addr,hp->h_length);  
  server.sin_family   =   hp->h_addrtype;  
  server.sin_port   =   htons(port);  
   
  conn_socket   =   socket(AF_INET,socket_type,0);   /*   打开一个   socket   
  if   (conn_socket   <   0   )   {  
  fprintf(stderr,"Client:   Error   Opening   socket:   Error   %d\n",  
  WSAGetLastError());  
  pPar->pPair->IsProxy_ServerClosed=TRUE;  
  ::SetEvent(pPar->User_SvrOK);  
  return   -1;  
  }  
   
   
  #ifdef   _DEBUG  
  printf("Client   connecting   to:   %s\n",hp->h_name);  
  #endif  
  if   (connect(conn_socket,(struct   sockaddr*)&server,sizeof(server))  
  ==   SOCKET_ERROR)   {  
  fprintf(stderr,"connect()   failed:   %d\n",WSAGetLastError());  
  pPar->pPair->IsProxy_ServerClosed=TRUE;  
  ::SetEvent(pPar->User_SvrOK);  
  return   -1;  
  }  
  pPar->pPair->proxy_server=conn_socket;  
  pPar->pPair->IsProxy_ServerClosed=FALSE;  
          ::SetEvent(pPar->User_SvrOK);  
  //   cook   up   a   string   to   send  
  while(!pPar->pPair->IsProxy_ServerClosed   &&!pPar->pPair->IsUser_ProxyClosed)  
  {  
  retval   =   recv(conn_socket,Buffer,sizeof   (Buffer),0   );  
  if   (retval   ==   SOCKET_ERROR   )   {  
  fprintf(stderr,"recv()   failed:   error   %d\n",WSAGetLastError());  
  closesocket(conn_socket);  
  pPar->pPair->IsProxy_ServerClosed=TRUE;  
  break;  
  }  
  Len=retval;  
  if   (retval   ==   0)   {  
  printf("Server   closed   connection\n");  
  closesocket(conn_socket);  
  pPar->pPair->IsProxy_ServerClosed=TRUE;  
  break;  
  }  
   
  retval   =   send(pPar->pPair->user_proxy,Buffer,Len,0);  
  if   (retval   ==   SOCKET_ERROR)   
  {  
		fprintf(stderr,"send()   failed:   error   %d\n",WSAGetLastError());  
	  closesocket(pPar->pPair->user_proxy);  
	  pPar->pPair->IsUser_ProxyClosed=TRUE;  
	  break;  
  }  
  #ifdef   _DEBUG  
  Buffer[Len]=0;  
  printf("Received   %d   bytes,   data   [%s]   from   server\n",retval,Buffer);  
  #endif  
  }  
  if(pPar->pPair->IsProxy_ServerClosed==FALSE)  
  {  
  closesocket(pPar->pPair->proxy_server);  
  pPar->pPair->IsProxy_ServerClosed=TRUE;  
  }  
    if(pPar->pPair->IsUser_ProxyClosed==FALSE)  
  {closesocket(pPar->pPair->user_proxy);  
    pPar->pPair->IsUser_ProxyClosed=TRUE;  
  }  
    return   1;  
  }  
   
   
   
int    main(int   argc,   TCHAR*   argv[],   TCHAR*   envp[])  
{  
		int   nRetCode   =   0;  
		//   初始化SOCKET  
		if   (0 )  
		{  
				//   错误处理  
				nRetCode   =   1;  
		}  
		else  
		{  
				//   主程序开始.  
				StartServer();  
				while(1)  
				{
					if(getchar()=='q') 
						break;  
				}
				CloseServer();  
		} 
		return   nRetCode;  
} 
*/