teleport/lib/srv/db/sqlserver/test.go

/*
Copyright 2022 Gravitational, Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package sqlserver

import (
	"context"
	"io"
	"net"
	"strconv"

	"github.com/gravitational/trace"
	mssql "github.com/microsoft/go-mssqldb"
	"github.com/microsoft/go-mssqldb/msdsn"
	"github.com/sirupsen/logrus"

	"github.com/gravitational/teleport/lib/defaults"
	"github.com/gravitational/teleport/lib/srv/db/common"
	"github.com/gravitational/teleport/lib/srv/db/sqlserver/protocol"
	"github.com/gravitational/teleport/lib/utils"
)

// MakeTestClient returns SQL Server client used in tests.
func MakeTestClient(ctx context.Context, config common.TestClientConfig) (*mssql.Conn, error) {
	host, port, err := net.SplitHostPort(config.Address)
	if err != nil {
		return nil, trace.Wrap(err)
	}

	portI, err := strconv.ParseUint(port, 10, 64)
	if err != nil {
		return nil, trace.Wrap(err)
	}

	connector := mssql.NewConnectorConfig(msdsn.Config{
		Host:       host,
		Port:       portI,
		User:       config.RouteToDatabase.Username,
		Database:   config.RouteToDatabase.Database,
		Encryption: msdsn.EncryptionDisabled,
		Protocols:  []string{"tcp"},
	}, nil)

	conn, err := connector.Connect(ctx)
	if err != nil {
		return nil, trace.Wrap(err)
	}

	mssqlConn, ok := conn.(*mssql.Conn)
	if !ok {
		return nil, trace.BadParameter("expected *mssql.Conn, got: %T", conn)
	}

	return mssqlConn, nil
}

// TestConnector is used in tests to mock connections to SQL Server.
type TestConnector struct{}

// Connect simulates successful connection to a SQL Server.
func (c *TestConnector) Connect(ctx context.Context, sessionCtx *common.Session, loginPacket *protocol.Login7Packet) (io.ReadWriteCloser, []mssql.Token, error) {
	host, port, err := net.SplitHostPort(sessionCtx.Database.GetURI())
	if err != nil {
		return nil, nil, trace.Wrap(err)
	}

	portI, err := strconv.ParseUint(port, 10, 64)
	if err != nil {
		return nil, nil, trace.Wrap(err)
	}

	// Pass all login options from the client to the server.
	options := msdsn.LoginOptions{
		OptionFlags1: loginPacket.OptionFlags1(),
		OptionFlags2: loginPacket.OptionFlags2(),
		TypeFlags:    loginPacket.TypeFlags(),
	}

	connector := mssql.NewConnectorConfig(msdsn.Config{
		Host:         host,
		Port:         portI,
		LoginOptions: options,
		Protocols:    []string{"tcp"},
	}, nil)

	conn, err := connector.Connect(ctx)
	if err != nil {
		return nil, nil, trace.Wrap(err)
	}

	mssqlConn, ok := conn.(*mssql.Conn)
	if !ok {
		return nil, nil, trace.BadParameter("expected *mssql.Conn, got: %T", conn)
	}

	return mssqlConn.GetUnderlyingConn(), mssqlConn.GetLoginFlags(), nil
}

// TestServer is a test MSServer server used in functional database
// access tests.
type TestServer struct {
	cfg      common.TestServerConfig
	listener net.Listener
	port     string
	log      logrus.FieldLogger
}

// NewTestServer returns a new instance of a test MSServer.
func NewTestServer(config common.TestServerConfig) (svr *TestServer, err error) {
	err = config.CheckAndSetDefaults()
	if err != nil {
		return nil, trace.Wrap(err)
	}
	defer config.CloseOnError(&err)

	port, err := config.Port()
	if err != nil {
		return nil, trace.Wrap(err)
	}
	log := logrus.WithFields(logrus.Fields{
		trace.Component: defaults.ProtocolSQLServer,
		"name":          config.Name,
	})
	server := &TestServer{
		cfg:      config,
		listener: config.Listener,
		port:     port,
		log:      log,
	}
	return server, nil
}

// Port returns SQL Server port.
func (s *TestServer) Port() string {
	return s.port
}

// Serve starts serving client connections.
func (s *TestServer) Serve() error {
	s.log.Debugf("Starting test MSServer server on %v.", s.listener.Addr())
	defer s.log.Debug("Test MSServer server stopped.")
	for {
		conn, err := s.listener.Accept()
		if err != nil {
			if utils.IsOKNetworkError(err) {
				return nil
			}
			s.log.WithError(err).Error("Failed to accept connection.")
			continue
		}
		s.log.Debug("Accepted connection.")
		go func() {
			defer s.log.Debug("Connection done.")
			defer conn.Close()
			err = s.handleConnection(conn)
			if err != nil {
				s.log.Errorf("Failed to handle connection: %v.",
					trace.DebugReport(err))
			}
		}()
	}
}

func (s *TestServer) handleConnection(conn net.Conn) error {
	if err := handleLogin(conn); err != nil {
		return trace.Wrap(err)
	}
	for {
		basicPacket, err := protocol.ReadPacket(conn)
		if err != nil {
			return trace.Wrap(err)
		}
		packet, err := protocol.ToSQLPacket(basicPacket)
		if err != nil {
			return trace.Wrap(err)
		}

		switch packet.(type) {
		case *protocol.SQLBatch:
			if _, err = conn.Write(mockSQLBatchServerResp); err != nil {
				return trace.Wrap(err)
			}
		}
	}
}

func handleLogin(conn net.Conn) error {
	if _, err := protocol.ReadPreLoginPacket(conn); err != nil {
		return trace.Wrap(err)
	}
	if err := protocol.WritePreLoginResponse(conn); err != nil {
		return trace.Wrap(err)
	}
	if _, err := protocol.ReadLogin7Packet(conn); err != nil {
		return trace.Wrap(err)
	}
	if _, err := conn.Write(mockLoginServerResp); err != nil {
		return trace.Wrap(err)
	}
	return nil
}

// Close closes the server listener.
func (s *TestServer) Close() error {
	return s.listener.Close()
}

var (
	mockLoginServerResp = []byte{
		0x04, 0x01, 0x00, 0xa7, 0x00, 0x00, 0x00, 0x00, 0xe3, 0x1b, 0x00, 0x01, 0x06, 0x6d, 0x00, 0x61,
		0x00, 0x73, 0x00, 0x74, 0x00, 0x65, 0x00, 0x72, 0x00, 0x06, 0x6d, 0x00, 0x61, 0x00, 0x73, 0x00,
		0x74, 0x00, 0x65, 0x00, 0x72, 0x00, 0xe3, 0x08, 0x00, 0x07, 0x05, 0x09, 0x04, 0xd0, 0x00, 0x34,
		0x00, 0xe3, 0x17, 0x00, 0x02, 0x0a, 0x75, 0x00, 0x73, 0x00, 0x5f, 0x00, 0x65, 0x00, 0x6e, 0x00,
		0x67, 0x00, 0x6c, 0x00, 0x69, 0x00, 0x73, 0x00, 0x68, 0x00, 0x00, 0xad, 0x36, 0x00, 0x01, 0x74,
		0x00, 0x00, 0x04, 0x16, 0x4d, 0x00, 0x69, 0x00, 0x63, 0x00, 0x72, 0x00, 0x6f, 0x00, 0x73, 0x00,
		0x6f, 0x00, 0x66, 0x00, 0x74, 0x00, 0x20, 0x00, 0x53, 0x00, 0x51, 0x00, 0x4c, 0x00, 0x20, 0x00,
		0x53, 0x00, 0x65, 0x00, 0x72, 0x00, 0x76, 0x00, 0x65, 0x00, 0x72, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x0f, 0x00, 0x0f, 0xe9, 0xe3, 0x13, 0x00, 0x04, 0x04, 0x34, 0x00, 0x30, 0x00, 0x39, 0x00, 0x36,
		0x00, 0x04, 0x34, 0x00, 0x30, 0x00, 0x39, 0x00, 0x36, 0x00, 0xfd, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	}
	mockSQLBatchServerResp = []byte{
		0x04, 0x01, 0x00, 0x2b, 0x00, 0x4a, 0x01, 0x00, 0xe3, 0x03, 0x00, 0x12, 0x00, 0x00, 0x81, 0x01,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0x00, 0x38, 0x00, 0xd1, 0x01, 0x00, 0x00, 0x00, 0xfd, 0x10,
		0x00, 0xc1, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	}
)