vncproxy/server/server-conn.go

package server

import (
	"encoding/binary"
	"fmt"
	"io"
	"sync"
	"vncproxy/common"
	"vncproxy/logger"
)

type ServerConn struct {
	c   io.ReadWriter
	cfg *ServerConfig

	protocol string
	m        sync.Mutex
	// If the pixel format uses a color map, then this is the color
	// map that is used. This should not be modified directly, since
	// the data comes from the server.
	colorMap *common.ColorMap

	// Name associated with the desktop, sent from the server.
	desktopName string

	// Encodings supported by the client. This should not be modified
	// directly. Instead, MsgSetEncodings() should be used.
	encodings []common.IEncoding

	// Height of the frame buffer in pixels, sent to the client.
	fbHeight uint16

	// Width of the frame buffer in pixels, sent to the client.
	fbWidth uint16

	// The pixel format associated with the connection. This shouldn't
	// be modified. If you wish to set a new pixel format, use the
	// SetPixelFormat method.
	pixelFormat *common.PixelFormat

	// a consumer for the parsed messages, to allow for recording and proxy
	Listeners *common.MultiListener

	SessionId string

	quit chan struct{}
}

// func (c *IServerConn) UnreadByte() error {
// 	return c.br.UnreadByte()
// }

func NewServerConn(c io.ReadWriter, cfg *ServerConfig) (*ServerConn, error) {
	// if cfg.ClientMessageCh == nil {
	// 	return nil, fmt.Errorf("ClientMessageCh nil")
	// }

	if len(cfg.ClientMessages) == 0 {
		return nil, fmt.Errorf("ClientMessage 0")
	}

	return &ServerConn{
		c: c,
		//br:          bufio.NewReader(c),
		//bw:          bufio.NewWriter(c),
		cfg:         cfg,
		quit:        make(chan struct{}),
		encodings:   cfg.Encodings,
		pixelFormat: cfg.PixelFormat,
		fbWidth:     cfg.Width,
		fbHeight:    cfg.Height,
		Listeners:   &common.MultiListener{},
	}, nil
}

func (c *ServerConn) Conn() io.ReadWriter {
	return c.c
}

func (c *ServerConn) SetEncodings(encs []common.EncodingType) error {
	encodings := make(map[int32]common.IEncoding)
	for _, enc := range c.cfg.Encodings {
		encodings[enc.Type()] = enc
	}
	for _, encType := range encs {
		if enc, ok := encodings[int32(encType)]; ok {
			c.encodings = append(c.encodings, enc)
		}
	}
	return nil
}

func (c *ServerConn) SetProtoVersion(pv string) {
	c.protocol = pv
}

func (c *ServerConn) Close() error {
	return c.c.(io.ReadWriteCloser).Close()
}

func (c *ServerConn) Read(buf []byte) (int, error) {
	return c.c.Read(buf)
}

func (c *ServerConn) Write(buf []byte) (int, error) {
	//	c.m.Lock()
	//	defer c.m.Unlock()
	return c.c.Write(buf)
}

func (c *ServerConn) ColorMap() *common.ColorMap {
	return c.colorMap
}

func (c *ServerConn) SetColorMap(cm *common.ColorMap) {
	c.colorMap = cm
}
func (c *ServerConn) DesktopName() string {
	return c.desktopName
}
func (c *ServerConn) CurrentPixelFormat() *common.PixelFormat {
	return c.pixelFormat
}
func (c *ServerConn) SetDesktopName(name string) {
	c.desktopName = name
}
func (c *ServerConn) SetPixelFormat(pf *common.PixelFormat) error {
	c.pixelFormat = pf
	return nil
}
func (c *ServerConn) Encodings() []common.IEncoding {
	return c.encodings
}
func (c *ServerConn) Width() uint16 {
	return c.fbWidth
}
func (c *ServerConn) Height() uint16 {
	return c.fbHeight
}
func (c *ServerConn) Protocol() string {
	return c.protocol
}
func (c *ServerConn) SetWidth(w uint16) {
	c.fbWidth = w
}
func (c *ServerConn) SetHeight(h uint16) {
	c.fbHeight = h
}

func (c *ServerConn) handle() error {

	defer func() {
		c.Listeners.Consume(&common.RfbSegment{
			SegmentType: common.SegmentConnectionClosed,
		})
	}()

	//create a map of all message types
	clientMessages := make(map[common.ClientMessageType]common.ClientMessage)
	for _, m := range c.cfg.ClientMessages {
		clientMessages[m.Type()] = m
	}

	for {
		select {
		case <-c.quit:
			return nil
		default:
			var messageType common.ClientMessageType
			if err := binary.Read(c, binary.BigEndian, &messageType); err != nil {
				logger.Errorf("IServerConn.handle error: %v", err)
				return err
			}
			msg, ok := clientMessages[messageType]
			if !ok {
				return fmt.Errorf("IServerConn.Handle: unsupported message-type: %v", messageType)
			}

			parsedMsg, err := msg.Read(c)

			//update connection for pixel format / color map changes
			switch parsedMsg.Type() {
			case common.SetPixelFormatMsgType:
				// update pixel format
				logger.Debugf("IServerConn.Handle: updating pixel format")
				pixFmtMsg := parsedMsg.(*MsgSetPixelFormat)
				c.SetPixelFormat(&pixFmtMsg.PF)
				if pixFmtMsg.PF.TrueColor != 0 {
					c.SetColorMap(&common.ColorMap{})
				}

			case common.FramebufferUpdateRequestMsgType:
				//logger.Infof("IServerConn.Handle:  msgBuff update request")
				//updMsg := parsedMsg.(*MsgFramebufferUpdateRequest)
				//updMsg.Inc = 1
			case common.SetEncodingsMsgType:
				encMsg := parsedMsg.(*MsgSetEncodings)
				// for i, enc := range encMsg.Encodings {
				// 	if enc > common.EncJPEGQualityLevelPseudo1 && enc < common.EncJPEGQualityLevelPseudo10 { //common.EncCursorPseudo
				// 		//encMsg.EncNum--
				// 		//encMsg.Encodings = append(encMsg.Encodings[:i], encMsg.Encodings[i+1:]...)
				// 		encMsg.Encodings[i] = encMsg.Encodings[len(encMsg.Encodings)-1]
				// 		encMsg.Encodings[len(encMsg.Encodings)-1] = common.EncJPEGQualityLevelPseudo9
				// 		break
				// 	}
				// 	// if enc == common.EncCompressionLevel3 {
				// 	// 	encMsg.Encodings[i] = common.EncJPEGQualityLevelPseudo9
				// 	// }
				// 	// if enc == common.EncJPEGQualityLevelPseudo7 {
				// 	// 	encMsg.Encodings[i] = common.EncJPEGQualityLevelPseudo9
				// 	// }
				// }

				encMsg.Encodings = []common.EncodingType{
					common.EncDesktopSizePseudo,
					common.EncExtendedDesktopSizePseudo,
					common.EncLastRectPseudo,
					common.EncContinuousUpdatesPseudo,
					common.EncCursorPseudo,
					common.EncFencePseudo,
					common.EncHextile,
					common.EncCopyRect,
					common.EncTight,
					common.EncZRLE,
					common.EncRRE,
					common.EncRaw,
					common.EncCompressionLevel2,
					common.EncJPEGQualityLevelPseudo1,
					common.EncQEMUExtendedKeyEventPseudo,
					common.EncTightPng,
					common.EncXvpPseudo,
				}
				encMsg.EncNum = uint16(len(encMsg.Encodings))

				//bad: EncCopyRect EncTight EncTightPng EncHextile EncRRE EncRaw EncJPEGQualityLevelPseudo7 EncCompressionLevel3 EncDesktopSizePseudo EncLastRectPseudo EncCursorPseudo EncQEMUExtendedKeyEventPseudo EncExtendedDesktopSizePseudo EncXvpPseudo EncFencePseudo EncContinuousUpdatesPseudo
			}

			////////

			if err != nil {
				logger.Errorf("srv err %s", err.Error())
				return err
			}

			logger.Infof("IServerConn.Handle got ClientMessage: %s, %v", parsedMsg.Type(), parsedMsg)
			//TODO: treat set encodings by allowing only supported encoding in proxy configurations
			//// if parsedMsg.Type() == common.SetEncodingsMsgType{
			//// 	c.cfg.Encodings
			//// }

			seg := &common.RfbSegment{
				SegmentType: common.SegmentFullyParsedClientMessage,
				Message:     parsedMsg,
			}
			err = c.Listeners.Consume(seg)
			if err != nil {
				logger.Errorf("IServerConn.Handle: listener consume err %s", err.Error())
				return err
			}
		}
	}
}