@vinothnb/smb2/lib/tools/smb2-connection.js

SMB2 Client

/*
 * DEPENDENCIES
 */
var net = require('net');
var SMB2Forge = require('./smb2-forge');
var SMB2Request = SMB2Forge.request;

/*
 * CONNECTION MANAGER
 */
var SMB2Connection = (module.exports = {});

/*
 * CLOSE CONNECTION
 */
SMB2Connection.close = function(connection) {
  clearAutoCloseTimeout(connection);
  if (connection.connected) {
    connection.connected = false;
    connection.socket.end();
  }
};

/*
 * OPEN CONNECTION
 */
SMB2Connection.requireConnect = function(method) {
  return function() {
    var connection = this;
    var args = Array.prototype.slice.call(arguments);
    connect(connection, function(err) {
      // process the cb
      var cb = args.pop();
      if (typeof cb !== 'function') {
        args.push(cb);
        cb = function(err) {
          if (err) {
            if (!(err instanceof Error)) {
              err = new Error(String(err));
            }
            throw err;
          }
        };
      }
      cb = scheduleAutoClose(connection, cb);
      args.push(cb);

      // manage the connection error
      if (err) cb(err);
      else method.apply(connection, args);
    });
  };
};

/*
 * INIT CONNECTION
 */
SMB2Connection.init = function(connection) {
  // create a socket
  connection.connected = false;
  connection.socket = new net.Socket({
    allowHalfOpen: true,
  });

  // attach data events to socket
  connection.socket.on('data', SMB2Forge.response(connection));
  connection.errorHandler = [];
  connection.socket.on('error', function(err) {
    if (connection.errorHandler.length > 0) {
      connection.errorHandler[0].call(null, err);
    }
    if (connection.debug) {
      console.log('-- error'); // eslint-disable-line no-console
      console.log(arguments); // eslint-disable-line no-console
    }
  });
};

/*
 * PRIVATE FUNCTION TO HANDLE CONNECTION
 */
function connect(connection, cb) {
  if (connection.connected) {
    cb && cb(null);
    return;
  }

  cb = scheduleAutoClose(connection, cb);

  // set message id
  connection.messageId = 0;

  // set session id
  connection.SessionId = Math.floor(Math.random() * 256) & 0xff;

  // open TCP socket
  connection.socket.connect(connection.port, connection.ip);

  // SMB2 negotiate connection
  SMB2Request('negotiate', {}, connection, function(err) {
    if (err) cb && cb(err);
    // SMB2 setup session / negotiate ntlm
    else
      SMB2Request('session_setup_step1', {}, connection, function(err) {
        if (err) cb && cb(err);
        // SMB2 setup session / autheticate with ntlm
        else
          SMB2Request('session_setup_step2', {}, connection, function(err) {
            if (err) cb && cb(err);
            // SMB2 tree connect
            else
              SMB2Request('tree_connect', {}, connection, function(err) {
                if (err) cb && cb(err);
                else {
                  connection.connected = true;
                  cb && cb(null);
                }
              });
          });
      });
  });
}

/*
 * PRIVATE FUNCTION TO HANDLE CLOSING THE CONNECTION
 */
function clearAutoCloseTimeout(connection) {
  if (connection.scheduledAutoClose) {
    clearTimeout(connection.scheduledAutoClose);
    connection.scheduledAutoClose = null;
  }
}
function setAutoCloseTimeout(connection) {
  clearAutoCloseTimeout(connection);
  if (connection.autoCloseTimeout !== 0) {
    connection.scheduledAutoClose = setTimeout(function() {
      SMB2Connection.close(connection);
    }, connection.autoCloseTimeout);
  }
}
function scheduleAutoClose(connection, cb) {
  addErrorListener(connection, cb);
  clearAutoCloseTimeout(connection);
  return function() {
    removeErrorListener(connection);
    setAutoCloseTimeout(connection);
    cb.apply(null, arguments);
  };
}

/*
 * PRIVATE FUNCTIONS TO HANDLE ERRORS
 */
function addErrorListener(connection, callback) {
  connection.errorHandler.unshift(callback);
}
function removeErrorListener(connection) {
  connection.errorHandler.shift();
}