added a vnc server and the required client messages parsers.

now I should get to tying up the proxying connections and checking what should be written to the file. (server init?)

common/encoding.go

@@ -1,5 +1,11 @@
 package common
 
+import (
+	"encoding/binary"
+	"bytes"
+	"io"
+)
+
 // An Encoding implements a method for encoding pixel data that is
 // sent by the server to the client.
 type Encoding interface {
@@ -22,3 +28,168 @@ const (
 	EncodingTight    = 7
 	EncodingZRLE     = 16
 )
+
+// EncodingType represents a known VNC encoding type.
+type EncodingType int32
+
+//go:generate stringer -type=EncodingType
+
+const (
+	EncRaw                           EncodingType = 0
+	EncCopyRect                      EncodingType = 1
+	EncRRE                           EncodingType = 2
+	EncCoRRE                         EncodingType = 4
+	EncHextile                       EncodingType = 5
+	EncZlib                          EncodingType = 6
+	EncTight                         EncodingType = 7
+	EncZlibHex                       EncodingType = 8
+	EncUltra1                        EncodingType = 9
+	EncUltra2                        EncodingType = 10
+	EncJPEG                          EncodingType = 21
+	EncJRLE                          EncodingType = 22
+	EncTRLE                          EncodingType = 15
+	EncZRLE                          EncodingType = 16
+	EncJPEGQualityLevelPseudo10      EncodingType = -23
+	EncJPEGQualityLevelPseudo9       EncodingType = -24
+	EncJPEGQualityLevelPseudo8       EncodingType = -25
+	EncJPEGQualityLevelPseudo7       EncodingType = -26
+	EncJPEGQualityLevelPseudo6       EncodingType = -27
+	EncJPEGQualityLevelPseudo5       EncodingType = -28
+	EncJPEGQualityLevelPseudo4       EncodingType = -29
+	EncJPEGQualityLevelPseudo3       EncodingType = -30
+	EncJPEGQualityLevelPseudo2       EncodingType = -31
+	EncJPEGQualityLevelPseudo1       EncodingType = -32
+	EncColorPseudo                   EncodingType = -239
+	EncDesktopSizePseudo             EncodingType = -223
+	EncLastRectPseudo                EncodingType = -224
+	EncCompressionLevel10            EncodingType = -247
+	EncCompressionLevel9             EncodingType = -248
+	EncCompressionLevel8             EncodingType = -249
+	EncCompressionLevel7             EncodingType = -250
+	EncCompressionLevel6             EncodingType = -251
+	EncCompressionLevel5             EncodingType = -252
+	EncCompressionLevel4             EncodingType = -253
+	EncCompressionLevel3             EncodingType = -254
+	EncCompressionLevel2             EncodingType = -255
+	EncCompressionLevel1             EncodingType = -256
+	EncQEMUPointerMotionChangePseudo EncodingType = -257
+	EncQEMUExtendedKeyEventPseudo    EncodingType = -258
+	EncTightPng                      EncodingType = -260
+	EncExtendedDesktopSizePseudo     EncodingType = -308
+	EncXvpPseudo                     EncodingType = -309
+	EncFencePseudo                   EncodingType = -312
+	EncContinuousUpdatesPseudo       EncodingType = -313
+	EncClientRedirect                EncodingType = -311
+)
+
+// PixelFormat describes the way a pixel is formatted for a VNC connection.
+//
+// See RFC 6143 Section 7.4 for information on each of the fields.
+type PixelFormat struct {
+	BPP        uint8
+	Depth      uint8
+	BigEndian  bool
+	TrueColor  bool
+	RedMax     uint16
+	GreenMax   uint16
+	BlueMax    uint16
+	RedShift   uint8
+	GreenShift uint8
+	BlueShift  uint8
+}
+
+func (format *PixelFormat) WriteTo(w io.Writer) ( error) {
+	var buf bytes.Buffer
+
+	// Byte 1
+	if err := binary.Write(&buf, binary.BigEndian, format.BPP); err != nil {
+		return  err
+	}
+
+	// Byte 2
+	if err := binary.Write(&buf, binary.BigEndian, format.Depth); err != nil {
+		return  err
+	}
+
+	var boolByte byte
+	if format.BigEndian {
+		boolByte = 1
+	} else {
+		boolByte = 0
+	}
+
+	// Byte 3 (BigEndian)
+	if err := binary.Write(&buf, binary.BigEndian, boolByte); err != nil {
+		return  err
+	}
+
+	if format.TrueColor {
+		boolByte = 1
+	} else {
+		boolByte = 0
+	}
+
+	// Byte 4 (TrueColor)
+	if err := binary.Write(&buf, binary.BigEndian, boolByte); err != nil {
+		return  err
+	}
+
+	// If we have true color enabled then we have to fill in the rest of the
+	// structure with the color values.
+	if format.TrueColor {
+		if err := binary.Write(&buf, binary.BigEndian, format.RedMax); err != nil {
+			return  err
+		}
+
+		if err := binary.Write(&buf, binary.BigEndian, format.GreenMax); err != nil {
+			return  err
+		}
+
+		if err := binary.Write(&buf, binary.BigEndian, format.BlueMax); err != nil {
+			return  err
+		}
+
+		if err := binary.Write(&buf, binary.BigEndian, format.RedShift); err != nil {
+			return  err
+		}
+
+		if err := binary.Write(&buf, binary.BigEndian, format.GreenShift); err != nil {
+			return  err
+		}
+
+		if err := binary.Write(&buf, binary.BigEndian, format.BlueShift); err != nil {
+			return  err
+		}
+	}
+
+	w.Write(buf.Bytes()[0:16])
+	return  nil
+}
+
+func NewPixelFormat(bpp uint8) *PixelFormat {
+	bigEndian := false
+	//	rgbMax := uint16(math.Exp2(float64(bpp))) - 1
+	rMax := uint16(255)
+	gMax := uint16(255)
+	bMax := uint16(255)
+	var (
+		tc         = true
+		rs, gs, bs uint8
+		depth      uint8
+	)
+	switch bpp {
+	case 8:
+		tc = false
+		depth = 8
+		rs, gs, bs = 0, 0, 0
+	case 16:
+		depth = 16
+		rs, gs, bs = 0, 4, 8
+	case 32:
+		depth = 24
+		//	rs, gs, bs = 0, 8, 16
+		rs, gs, bs = 16, 8, 0
+	}
+
+	return &PixelFormat{bpp, depth, bigEndian, tc, rMax, gMax, bMax, rs, gs, bs}
+}