ftp.cpp

一个用QT开发的FTP客户端

	closeConnection();
	return ftpOpenControlConnection(host, port, true);
      }
    }
  }

  // if there was a problem - report it ...
  if(iErrorCode == 0)             // OK, return success
    return true;
  closeConnection();              // clean-up on error
  error(iErrorCode, sErrorMsg);
  return false;
}

/**
 * Called by @ref openConnection. It logs us in.
 * @ref m_initialPath is set to the current working directory
 * if logging on was successful.
 *
 * @return true on success.
 */
bool Ftp::ftpLogin()
{
  infoMessage( i18n("Sending login information") );

  assert( !m_bLoggedOn );

  QString user = m_user;
  QString pass = m_pass;

  if ( config()->readEntry("EnableAutoLogin", false) )
  {
    QString au = config()->readEntry("autoLoginUser");
    if ( !au.isEmpty() )
    {
        user = au;
        pass = config()->readEntry("autoLoginPass");
    }
  }

  // Try anonymous login if both username/password
  // information is blank.
  if (user.isEmpty() && pass.isEmpty())
  {
    user = FTP_LOGIN;
    pass = FTP_PASSWD;
  }

  AuthInfo info;
  info.url.setProtocol( "ftp" );
  info.url.setHost( m_host );
  if ( m_port > 0 && m_port != DEFAULT_FTP_PORT )
      info.url.setPort( m_port );
  info.url.setUser( user );

  QByteArray tempbuf;
  int failedAuth = 0;

  do
  {
    // Check the cache and/or prompt user for password if 1st
    // login attempt failed OR the user supplied a login name,
    // but no password.
    if ( failedAuth > 0 || (!user.isEmpty() && pass.isEmpty()) )
    {
      QString errorMsg;
      kDebug(7102) << "Prompting user for login info...";

      // Ask user if we should retry after when login fails!
      if( failedAuth > 0 )
      {
        errorMsg = i18n("Message sent:\nLogin using username=%1 and "
                        "password=[hidden]\n\nServer replied:\n%2\n\n"
                        , user, ftpResponse(0));
      }

      if ( user != FTP_LOGIN )
        info.username = user;

      info.prompt = i18n("You need to supply a username and a password "
                          "to access this site.");
      info.commentLabel = i18n( "Site:" );
      info.comment = i18n("<b>%1</b>",  m_host );
      info.keepPassword = true; // Prompt the user for persistence as well.
      info.readOnly = (!m_user.isEmpty() && m_user != FTP_LOGIN);

      bool disablePassDlg = config()->readEntry( "DisablePassDlg", false );
      if ( disablePassDlg || !openPasswordDialog( info, errorMsg ) )
      {
        error( ERR_USER_CANCELED, m_host );
        return false;
      }
      else
      {
        user = info.username;
        pass = info.password;
      }
    }

    tempbuf = "USER ";
    tempbuf += user.toLatin1();
    if ( m_bUseProxy )
    {
      tempbuf += '@';
      tempbuf += m_host.toLatin1();
      if ( m_port > 0 && m_port != DEFAULT_FTP_PORT )
      {
        tempbuf += ':';
        tempbuf += QString::number(m_port).toLatin1();
      }
    }

    kDebug(7102) << "Sending Login name: " << tempbuf;

    bool loggedIn = ( ftpSendCmd(tempbuf) && (m_iRespCode == 230) );
    bool needPass = (m_iRespCode == 331);
    // Prompt user for login info if we do not
    // get back a "230" or "331".
    if ( !loggedIn && !needPass )
    {
      kDebug(7102) << "Login failed: " << ftpResponse(0);
      ++failedAuth;
      continue;  // Well we failed, prompt the user please!!
    }

    if( needPass )
    {
      tempbuf = "pass ";
      tempbuf += pass.toLatin1();
      kDebug(7102) << "Sending Login password: " << "[protected]";
      loggedIn = ( ftpSendCmd(tempbuf) && (m_iRespCode == 230) );
    }

    if ( loggedIn )
    {
      // Do not cache the default login!!
      if( user != FTP_LOGIN && pass != FTP_PASSWD )
        cacheAuthentication( info );
      failedAuth = -1;
    }

  } while( ++failedAuth );


  kDebug(7102) << "Login OK";
  infoMessage( i18n("Login OK") );

  // Okay, we're logged in. If this is IIS 4, switch dir listing style to Unix:
  // Thanks to [e-mail] (Jens Kristian Sgaard) for this hint
  if( ftpSendCmd("SYST") && (m_iRespType == 2) )
  {
    if( !strncmp( ftpResponse(0), "215 Windows_NT", 14 ) ) // should do for any version
    {
      ftpSendCmd( "site dirstyle" );
      // Check if it was already in Unix style
      // Patch from Keith Refson <[e-mail]>
      if( !strncmp( ftpResponse(0), "200 MSDOS-like directory output is on", 37 ))
         //It was in Unix style already!
         ftpSendCmd( "site dirstyle" );
      // windows won't support chmod before KDE konquers their desktop...
      m_extControl |= chmodUnknown;
    }
  }
  else
    kWarning(7102) << "SYST failed";

  if ( config()->readEntry ("EnableAutoLoginMacro", false) )
    ftpAutoLoginMacro ();

  // Get the current working directory
  kDebug(7102) << "Searching for pwd";
  if( !ftpSendCmd("PWD") || (m_iRespType != 2) )
  {
    kDebug(7102) << "Couldn't issue pwd command";
    error( ERR_COULD_NOT_LOGIN, i18n("Could not login to %1.", m_host) ); // or anything better ?
    return false;
  }

  QString sTmp = remoteEncoding()->decode( ftpResponse(3) );
  int iBeg = sTmp.indexOf('"');
  int iEnd = sTmp.lastIndexOf('"');
  if(iBeg > 0 && iBeg < iEnd)
  {
    m_initialPath = sTmp.mid(iBeg+1, iEnd-iBeg-1);
    if(m_initialPath[0] != '/') m_initialPath.prepend('/');
    kDebug(7102) << "Initial path set to: " << m_initialPath;
    m_currentPath = m_initialPath;
  }
  return true;
}

void Ftp::ftpAutoLoginMacro ()
{
  QString macro = metaData( "autoLoginMacro" );

  if ( macro.isEmpty() )
    return;

  QStringList list = macro.split('\n',QString::SkipEmptyParts);

  for(QStringList::Iterator it = list.begin() ; it != list.end() ; ++it )
  {
    if ( (*it).startsWith("init") )
    {
      list = macro.split( '\\',QString::SkipEmptyParts);
      it = list.begin();
      ++it;  // ignore the macro name

      for( ; it != list.end() ; ++it )
      {
        // TODO: Add support for arbitrary commands
        // besides simply changing directory!!
        if ( (*it).startsWith( "cwd" ) )
          ftpFolder( (*it).mid(4).trimmed(), false );
      }

      break;
    }
  }
}


/**
 * ftpSendCmd - send a command (@p cmd) and read response
 *
 * @param maxretries number of time it should retry. Since it recursively
 * calls itself if it can't read the answer (this happens especially after
 * timeouts), we need to limit the recursiveness ;-)
 *
 * return true if any response received, false on error
 */
bool Ftp::ftpSendCmd( const QByteArray& cmd, int maxretries )
{
  assert(m_control != NULL);    // must have control connection socket

  if ( cmd.indexOf( '\r' ) != -1 || cmd.indexOf( '\n' ) != -1)
  {
    kWarning(7102) << "Invalid command received (contains CR or LF):"
                    << cmd.data();
    error( ERR_UNSUPPORTED_ACTION, m_host );
    return false;
  }

  // Don't print out the password...
  bool isPassCmd = (cmd.left(4).toLower() == "pass");
  if ( !isPassCmd )
    kDebug(7102) << "send> " << cmd.data();
  else
    kDebug(7102) << "send> pass [protected]";

  // Send the message...
  QByteArray buf = cmd;
  buf += "\r\n";      // Yes, must use CR/LF - see http://cr.yp.to/ftp/request.html
  int num = m_control->write(buf);
  while (m_control->bytesToWrite() && m_control->waitForBytesWritten()) {}

  // If we were able to successfully send the command, then we will
  // attempt to read the response. Otherwise, take action to re-attempt
  // the login based on the maximum number of retires specified...
  if( num > 0 )
    ftpResponse(-1);
  else
  {
    m_iRespType = m_iRespCode = 0;
  }

  // If respCh is NULL or the response is 421 (Timed-out), we try to re-send
  // the command based on the value of maxretries.
  if( (m_iRespType <= 0) || (m_iRespCode == 421) )
  {
    // We have not yet logged on...
    if (!m_bLoggedOn)
    {
      // The command was sent from the ftpLogin function, i.e. we are actually
      // attempting to login in. NOTE: If we already sent the username, we
      // return false and let the user decide whether (s)he wants to start from
      // the beginning...
      if (maxretries > 0 && !isPassCmd)
      {
        closeConnection ();
        if( ftpOpenConnection(loginDefered) )
          ftpSendCmd ( cmd, maxretries - 1 );
      }

      return false;
    }
    else
    {
      if ( maxretries < 1 )
        return false;
      else
      {
        kDebug(7102) << "Was not able to communicate with " << m_host
                      << "Attempting to re-establish connection.";

        closeConnection(); // Close the old connection...
        openConnection();  // Attempt to re-establish a new connection...

        if (!m_bLoggedOn)
        {
          if (m_control != NULL)  // if openConnection succeeded ...
          {
            kDebug(7102) << "Login failure, aborting";
            error (ERR_COULD_NOT_LOGIN, m_host);
            closeConnection ();
          }
          return false;
        }

        kDebug(7102) << "Logged back in, re-issuing command";

        // If we were able to login, resend the command...
        if (maxretries)
          maxretries--;

        return ftpSendCmd( cmd, maxretries );
      }
    }
  }

  return true;
}

/*
 * ftpOpenPASVDataConnection - set up data connection, using PASV mode
 *
 * return 0 if successful, ERR_INTERNAL otherwise
 * doesn't set error message, since non-pasv mode will always be tried if
 * this one fails
 */
int Ftp::ftpOpenPASVDataConnection()
{
  assert(m_control != NULL);    // must have control connection socket
  assert(m_data == NULL);       // ... but no data connection

  // Check that we can do PASV
  QHostAddress addr = m_control->peerAddress();
  if (addr.protocol() != QAbstractSocket::IPv4Protocol)
    return ERR_INTERNAL;       // no PASV for non-PF_INET connections

 if (m_extControl & pasvUnknown)
    return ERR_INTERNAL;       // already tried and got "unknown command"

  m_bPasv = true;

  /* Let's PASsiVe*/
  if( !ftpSendCmd("PASV") || (m_iRespType != 2) )
  {
    kDebug(7102) << "PASV attempt failed";
    // unknown command?
    if( m_iRespType == 5 )
    {
        kDebug(7102) << "disabling use of PASV";
        m_extControl |= pasvUnknown;
    }
    return ERR_INTERNAL;
  }

  // The usual answer is '227 Entering Passive Mode. (160,39,200,55,6,245)'
  // but anonftpd gives '227 =160,39,200,55,6,245'
  int i[6];
  const char *start = strchr(ftpResponse(3), '(');
  if ( !start )
    start = strchr(ftpResponse(3), '=');
  if ( !start ||
       ( sscanf(start, "(%d,%d,%d,%d,%d,%d)",&i[0], &i[1], &i[2], &i[3], &i[4], &i[5]) != 6 &&
         sscanf(start, "=%d,%d,%d,%d,%d,%d", &i[0], &i[1], &i[2], &i[3], &i[4], &i[5]) != 6 ) )
  {
    kError(7102) << "parsing IP and port numbers failed. String parsed: " << start;
    return ERR_INTERNAL;
  }

  // we ignore the host part on purpose for two reasons
  // a) it might be wrong anyway
  // b) it would make us being suceptible to a port scanning attack

  // now connect the data socket ...
  quint16 port = i[4] << 8 | i[5];
  kDebug(7102) << "Connecting to " << addr.toString() << " port " << port;

  m_data = new QSslSocket();
  KSocketFactory::synchronousConnectToHost(m_data, "ftp-data", addr.toString(), port, connectTimeout() * 1000);

  return m_data->state() == QAbstractSocket::ConnectedState ? 0 : ERR_INTERNAL;
}

/*
 * ftpOpenEPSVDataConnection - opens a data connection via EPSV
 */
int Ftp::ftpOpenEPSVDataConnection()
{
  assert(m_control != NULL);    // must have control connection socket
  assert(m_data == NULL);       // ... but no data connection

  QHostAddress address = m_control->peerAddress();
  int portnum;

  if (m_extControl & epsvUnknown)
    return ERR_INTERNAL;

  m_bPasv = true;
  if( !ftpSendCmd("EPSV") || (m_iRespType != 2) )
  {
    // unknown command?
    if( m_iRespType == 5 )
    {
       kDebug(7102) << "disabling use of EPSV";
       m_extControl |= epsvUnknown;
    }
    return ERR_INTERNAL;
  }

  const char *start = strchr(ftpResponse(3), '|');
  if ( !start || sscanf(start, "|||%d|", &portnum) != 1)
    return ERR_INTERNAL;

  m_data = new QSslSocket();
  KSocketFactory::synchronousConnectToHost(m_data, "ftp-data", address.toString(), portnum,
                                                    connectTimeout() * 1000);
  return m_data->isOpen() ? 0 : ERR_INTERNAL;
}

int Ftp::encryptDataChannel()
{
  if (m_bIgnoreSslErrors) m_data->ignoreSslErrors();

  if (m_bPasv) m_data->startClientEncryption();
  else m_data->startServerEncryption();

  if (!m_data->waitForEncrypted(connectTimeout() * 1000)) return ERR_SLAVE_DEFINED;

  return 0;
}

bool Ftp::requestDataEncryption()
{
  // initate tls transfer for data chanel on the control channel 

  bool pbszSucc = (ftpSendCmd("PBSZ 0") && (m_iRespType == 2));
  if (!pbszSucc) return false;
    
  // try protected data transfer first