packet: separate bmp stuff from bgp.go

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

2 files changed, 371 insertions, 350 deletions

diff --git a/packet/bgp.go b/packet/bgp.go
index c3e3c045..ed827327 100644
--- a/packet/bgp.go
+++ b/packet/bgp.go
@@ -5656,353 +5656,3 @@ func (msg *BGPMessage) Serialize() ([]byte, error) {
 	}
 	return append(h, b...), nil
 }
-
-// BMP
-
-type BMPHeader struct {
-	Version uint8
-	Length  uint32
-	Type    uint8
-}
-
-const (
-	BMP_HEADER_SIZE = 6
-)
-
-func (msg *BMPHeader) DecodeFromBytes(data []byte) error {
-	msg.Version = data[0]
-	if data[0] != 3 {
-		return fmt.Errorf("error version")
-	}
-	msg.Length = binary.BigEndian.Uint32(data[1:5])
-	msg.Type = data[5]
-	return nil
-}
-
-func (msg *BMPHeader) Len() int {
-	return int(msg.Length)
-}
-
-type BMPPeerHeader struct {
-	PeerType          uint8
-	IsPostPolicy      bool
-	PeerDistinguisher uint64
-	PeerAddress       net.IP
-	PeerAS            uint32
-	PeerBGPID         net.IP
-	Timestamp         float64
-	flags             uint8
-}
-
-func (msg *BMPPeerHeader) DecodeFromBytes(data []byte) error {
-	data = data[6:]
-
-	msg.PeerType = data[0]
-	flags := data[1]
-	msg.flags = flags
-	if flags&1<<6 == 1 {
-		msg.IsPostPolicy = true
-	} else {
-		msg.IsPostPolicy = false
-	}
-	msg.PeerDistinguisher = binary.BigEndian.Uint64(data[2:10])
-	if flags&1<<7 == 1 {
-		msg.PeerAddress = data[10:26]
-	} else {
-		msg.PeerAddress = data[10:14]
-	}
-	msg.PeerAS = binary.BigEndian.Uint32(data[26:30])
-	msg.PeerBGPID = data[30:34]
-
-	timestamp1 := binary.BigEndian.Uint32(data[34:38])
-	timestamp2 := binary.BigEndian.Uint32(data[38:42])
-	msg.Timestamp = float64(timestamp1) + float64(timestamp2)*math.Pow(10, -6)
-
-	return nil
-}
-
-type BMPRouteMonitoring struct {
-	BGPUpdate *BGPMessage
-}
-
-func (body *BMPRouteMonitoring) ParseBody(msg *BMPMessage, data []byte) error {
-	update, err := ParseBGPMessage(data)
-	if err != nil {
-		return err
-	}
-	body.BGPUpdate = update
-	return nil
-}
-
-const (
-	BMP_STAT_TYPE_REJECTED = iota
-	BMP_STAT_TYPE_DUPLICATE_PREFIX
-	BMP_STAT_TYPE_DUPLICATE_WITHDRAW
-	BMP_STAT_TYPE_INV_UPDATE_DUE_TO_CLUSTER_LIST_LOOP
-	BMP_STAT_TYPE_INV_UPDATE_DUE_TO_AS_PATH_LOOP
-	BMP_STAT_TYPE_INV_UPDATE_DUE_TO_ORIGINATOR_ID
-	BMP_STAT_TYPE_INV_UPDATE_DUE_TO_AS_CONFED_LOOP
-	BMP_STAT_TYPE_ADJ_RIB_IN
-	BMP_STAT_TYPE_LOC_RIB
-)
-
-type BMPStatsTLV struct {
-	Type   uint16
-	Length uint16
-	Value  uint64
-}
-
-type BMPStatisticsReport struct {
-	Stats []BMPStatsTLV
-}
-
-const (
-	BMP_PEER_DOWN_REASON_UNKNOWN = iota
-	BMP_PEER_DOWN_REASON_LOCAL_BGP_NOTIFICATION
-	BMP_PEER_DOWN_REASON_LOCAL_NO_NOTIFICATION
-	BMP_PEER_DOWN_REASON_REMOTE_BGP_NOTIFICATION
-	BMP_PEER_DOWN_REASON_REMOTE_NO_NOTIFICATION
-)
-
-type BMPPeerDownNotification struct {
-	Reason          uint8
-	BGPNotification *BGPMessage
-	Data            []byte
-}
-
-func (body *BMPPeerDownNotification) ParseBody(msg *BMPMessage, data []byte) error {
-	body.Reason = data[0]
-	data = data[1:]
-	if body.Reason == BMP_PEER_DOWN_REASON_LOCAL_BGP_NOTIFICATION || body.Reason == BMP_PEER_DOWN_REASON_REMOTE_BGP_NOTIFICATION {
-		notification, err := ParseBGPMessage(data)
-		if err != nil {
-			return err
-		}
-		body.BGPNotification = notification
-	} else {
-		body.Data = data
-	}
-	return nil
-}
-
-type BMPPeerUpNotification struct {
-	LocalAddress    net.IP
-	LocalPort       uint16
-	RemotePort      uint16
-	SentOpenMsg     *BGPMessage
-	ReceivedOpenMsg *BGPMessage
-}
-
-func (body *BMPPeerUpNotification) ParseBody(msg *BMPMessage, data []byte) error {
-	if msg.PeerHeader.flags&1<<7 == 1 {
-		body.LocalAddress = data[:16]
-	} else {
-		body.LocalAddress = data[:4]
-	}
-
-	body.LocalPort = binary.BigEndian.Uint16(data[16:18])
-	body.RemotePort = binary.BigEndian.Uint16(data[18:20])
-
-	data = data[20:]
-	sentopen, err := ParseBGPMessage(data)
-	if err != nil {
-		return err
-	}
-	body.SentOpenMsg = sentopen
-	data = data[body.SentOpenMsg.Header.Len:]
-	body.ReceivedOpenMsg, err = ParseBGPMessage(data)
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
-func (body *BMPStatisticsReport) ParseBody(msg *BMPMessage, data []byte) error {
-	_ = binary.BigEndian.Uint32(data[0:4])
-	data = data[4:]
-	for len(data) >= 4 {
-		s := BMPStatsTLV{}
-		s.Type = binary.BigEndian.Uint16(data[0:2])
-		s.Length = binary.BigEndian.Uint16(data[2:4])
-
-		if s.Type == BMP_STAT_TYPE_ADJ_RIB_IN || s.Type == BMP_STAT_TYPE_LOC_RIB {
-			s.Value = binary.BigEndian.Uint64(data[4:12])
-		} else {
-			s.Value = uint64(binary.BigEndian.Uint32(data[4:8]))
-		}
-		body.Stats = append(body.Stats, s)
-		data = data[4+s.Length:]
-	}
-	return nil
-}
-
-type BMPTLV struct {
-	Type   uint16
-	Length uint16
-	Value  []byte
-}
-
-type BMPInitiation struct {
-	Info []BMPTLV
-}
-
-func (body *BMPInitiation) ParseBody(msg *BMPMessage, data []byte) error {
-	for len(data) >= 4 {
-		tlv := BMPTLV{}
-		tlv.Type = binary.BigEndian.Uint16(data[0:2])
-		tlv.Length = binary.BigEndian.Uint16(data[2:4])
-		tlv.Value = data[4 : 4+tlv.Length]
-
-		body.Info = append(body.Info, tlv)
-		data = data[4+tlv.Length:]
-	}
-	return nil
-}
-
-type BMPTermination struct {
-	Info []BMPTLV
-}
-
-func (body *BMPTermination) ParseBody(msg *BMPMessage, data []byte) error {
-	for len(data) >= 4 {
-		tlv := BMPTLV{}
-		tlv.Type = binary.BigEndian.Uint16(data[0:2])
-		tlv.Length = binary.BigEndian.Uint16(data[2:4])
-		tlv.Value = data[4 : 4+tlv.Length]
-
-		body.Info = append(body.Info, tlv)
-		data = data[4+tlv.Length:]
-	}
-	return nil
-}
-
-type BMPBody interface {
-	ParseBody(*BMPMessage, []byte) error
-}
-
-type BMPMessage struct {
-	Header     BMPHeader
-	PeerHeader BMPPeerHeader
-	Body       BMPBody
-}
-
-func (msg *BMPMessage) Len() int {
-	return int(msg.Header.Length)
-}
-
-const (
-	BMP_MSG_ROUTE_MONITORING = iota
-	BMP_MSG_STATISTICS_REPORT
-	BMP_MSG_PEER_DOWN_NOTIFICATION
-	BMP_MSG_PEER_UP_NOTIFICATION
-	BMP_MSG_INITIATION
-	BMP_MSG_TERMINATION
-)
-
-// move somewhere else
-func ReadBMPMessage(conn net.Conn) (*BMPMessage, error) {
-	buf := make([]byte, BMP_HEADER_SIZE)
-	for offset := 0; offset < BMP_HEADER_SIZE; {
-		rlen, err := conn.Read(buf[offset:])
-		if err != nil {
-			return nil, err
-		}
-		offset += rlen
-	}
-
-	h := BMPHeader{}
-	err := h.DecodeFromBytes(buf)
-	if err != nil {
-		return nil, err
-	}
-
-	data := make([]byte, h.Len())
-	copy(data, buf)
-	data = data[BMP_HEADER_SIZE:]
-	for offset := 0; offset < h.Len()-BMP_HEADER_SIZE; {
-		rlen, err := conn.Read(data[offset:])
-		if err != nil {
-			return nil, err
-		}
-		offset += rlen
-	}
-	msg := &BMPMessage{Header: h}
-
-	switch msg.Header.Type {
-	case BMP_MSG_ROUTE_MONITORING:
-		msg.Body = &BMPRouteMonitoring{}
-	case BMP_MSG_STATISTICS_REPORT:
-		msg.Body = &BMPStatisticsReport{}
-	case BMP_MSG_PEER_DOWN_NOTIFICATION:
-		msg.Body = &BMPPeerDownNotification{}
-	case BMP_MSG_PEER_UP_NOTIFICATION:
-		msg.Body = &BMPPeerUpNotification{}
-	case BMP_MSG_INITIATION:
-		msg.Body = &BMPInitiation{}
-	case BMP_MSG_TERMINATION:
-		msg.Body = &BMPTermination{}
-	}
-
-	if msg.Header.Type != BMP_MSG_INITIATION && msg.Header.Type != BMP_MSG_INITIATION {
-		msg.PeerHeader.DecodeFromBytes(data)
-		data = data[42:]
-	}
-
-	err = msg.Body.ParseBody(msg, data)
-	if err != nil {
-		return nil, err
-	}
-	return msg, nil
-}
-
-func ParseBMPMessage(data []byte) (*BMPMessage, error) {
-	msg := &BMPMessage{}
-	msg.Header.DecodeFromBytes(data)
-	data = data[6:msg.Header.Length]
-
-	switch msg.Header.Type {
-	case BMP_MSG_ROUTE_MONITORING:
-		msg.Body = &BMPRouteMonitoring{}
-	case BMP_MSG_STATISTICS_REPORT:
-		msg.Body = &BMPStatisticsReport{}
-	case BMP_MSG_PEER_DOWN_NOTIFICATION:
-		msg.Body = &BMPPeerDownNotification{}
-	case BMP_MSG_PEER_UP_NOTIFICATION:
-		msg.Body = &BMPPeerUpNotification{}
-	case BMP_MSG_INITIATION:
-		msg.Body = &BMPInitiation{}
-	case BMP_MSG_TERMINATION:
-		msg.Body = &BMPTermination{}
-	}
-
-	if msg.Header.Type != BMP_MSG_INITIATION && msg.Header.Type != BMP_MSG_INITIATION {
-		msg.PeerHeader.DecodeFromBytes(data)
-		data = data[42:]
-	}
-
-	err := msg.Body.ParseBody(msg, data)
-	if err != nil {
-		return nil, err
-	}
-	return msg, nil
-}
-
-type MessageError struct {
-	TypeCode    uint8
-	SubTypeCode uint8
-	Data        []byte
-	Message     string
-}
-
-func NewMessageError(typeCode, subTypeCode uint8, data []byte, msg string) error {
-	return &MessageError{
-		TypeCode:    typeCode,
-		SubTypeCode: subTypeCode,
-		Data:        data,
-		Message:     msg,
-	}
-}
-
-func (e *MessageError) Error() string {
-	return e.Message
-}
diff --git a/packet/bmp.go b/packet/bmp.go
new file mode 100644
index 00000000..d7758120
--- /dev/null
+++ b/packet/bmp.go
@@ -0,0 +1,371 @@
+// Copyright (C) 2014,2015 Nippon Telegraph and Telephone Corporation.
+//
+// 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 bgp
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math"
+	"net"
+)
+
+type BMPHeader struct {
+	Version uint8
+	Length  uint32
+	Type    uint8
+}
+
+const (
+	BMP_HEADER_SIZE = 6
+)
+
+func (msg *BMPHeader) DecodeFromBytes(data []byte) error {
+	msg.Version = data[0]
+	if data[0] != 3 {
+		return fmt.Errorf("error version")
+	}
+	msg.Length = binary.BigEndian.Uint32(data[1:5])
+	msg.Type = data[5]
+	return nil
+}
+
+func (msg *BMPHeader) Len() int {
+	return int(msg.Length)
+}
+
+type BMPPeerHeader struct {
+	PeerType          uint8
+	IsPostPolicy      bool
+	PeerDistinguisher uint64
+	PeerAddress       net.IP
+	PeerAS            uint32
+	PeerBGPID         net.IP
+	Timestamp         float64
+	flags             uint8
+}
+
+func (msg *BMPPeerHeader) DecodeFromBytes(data []byte) error {
+	data = data[6:]
+
+	msg.PeerType = data[0]
+	flags := data[1]
+	msg.flags = flags
+	if flags&1<<6 == 1 {
+		msg.IsPostPolicy = true
+	} else {
+		msg.IsPostPolicy = false
+	}
+	msg.PeerDistinguisher = binary.BigEndian.Uint64(data[2:10])
+	if flags&1<<7 == 1 {
+		msg.PeerAddress = data[10:26]
+	} else {
+		msg.PeerAddress = data[10:14]
+	}
+	msg.PeerAS = binary.BigEndian.Uint32(data[26:30])
+	msg.PeerBGPID = data[30:34]
+
+	timestamp1 := binary.BigEndian.Uint32(data[34:38])
+	timestamp2 := binary.BigEndian.Uint32(data[38:42])
+	msg.Timestamp = float64(timestamp1) + float64(timestamp2)*math.Pow(10, -6)
+
+	return nil
+}
+
+type BMPRouteMonitoring struct {
+	BGPUpdate *BGPMessage
+}
+
+func (body *BMPRouteMonitoring) ParseBody(msg *BMPMessage, data []byte) error {
+	update, err := ParseBGPMessage(data)
+	if err != nil {
+		return err
+	}
+	body.BGPUpdate = update
+	return nil
+}
+
+const (
+	BMP_STAT_TYPE_REJECTED = iota
+	BMP_STAT_TYPE_DUPLICATE_PREFIX
+	BMP_STAT_TYPE_DUPLICATE_WITHDRAW
+	BMP_STAT_TYPE_INV_UPDATE_DUE_TO_CLUSTER_LIST_LOOP
+	BMP_STAT_TYPE_INV_UPDATE_DUE_TO_AS_PATH_LOOP
+	BMP_STAT_TYPE_INV_UPDATE_DUE_TO_ORIGINATOR_ID
+	BMP_STAT_TYPE_INV_UPDATE_DUE_TO_AS_CONFED_LOOP
+	BMP_STAT_TYPE_ADJ_RIB_IN
+	BMP_STAT_TYPE_LOC_RIB
+)
+
+type BMPStatsTLV struct {
+	Type   uint16
+	Length uint16
+	Value  uint64
+}
+
+type BMPStatisticsReport struct {
+	Stats []BMPStatsTLV
+}
+
+const (
+	BMP_PEER_DOWN_REASON_UNKNOWN = iota
+	BMP_PEER_DOWN_REASON_LOCAL_BGP_NOTIFICATION
+	BMP_PEER_DOWN_REASON_LOCAL_NO_NOTIFICATION
+	BMP_PEER_DOWN_REASON_REMOTE_BGP_NOTIFICATION
+	BMP_PEER_DOWN_REASON_REMOTE_NO_NOTIFICATION
+)
+
+type BMPPeerDownNotification struct {
+	Reason          uint8
+	BGPNotification *BGPMessage
+	Data            []byte
+}
+
+func (body *BMPPeerDownNotification) ParseBody(msg *BMPMessage, data []byte) error {
+	body.Reason = data[0]
+	data = data[1:]
+	if body.Reason == BMP_PEER_DOWN_REASON_LOCAL_BGP_NOTIFICATION || body.Reason == BMP_PEER_DOWN_REASON_REMOTE_BGP_NOTIFICATION {
+		notification, err := ParseBGPMessage(data)
+		if err != nil {
+			return err
+		}
+		body.BGPNotification = notification
+	} else {
+		body.Data = data
+	}
+	return nil
+}
+
+type BMPPeerUpNotification struct {
+	LocalAddress    net.IP
+	LocalPort       uint16
+	RemotePort      uint16
+	SentOpenMsg     *BGPMessage
+	ReceivedOpenMsg *BGPMessage
+}
+
+func (body *BMPPeerUpNotification) ParseBody(msg *BMPMessage, data []byte) error {
+	if msg.PeerHeader.flags&1<<7 == 1 {
+		body.LocalAddress = data[:16]
+	} else {
+		body.LocalAddress = data[:4]
+	}
+
+	body.LocalPort = binary.BigEndian.Uint16(data[16:18])
+	body.RemotePort = binary.BigEndian.Uint16(data[18:20])
+
+	data = data[20:]
+	sentopen, err := ParseBGPMessage(data)
+	if err != nil {
+		return err
+	}
+	body.SentOpenMsg = sentopen
+	data = data[body.SentOpenMsg.Header.Len:]
+	body.ReceivedOpenMsg, err = ParseBGPMessage(data)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (body *BMPStatisticsReport) ParseBody(msg *BMPMessage, data []byte) error {
+	_ = binary.BigEndian.Uint32(data[0:4])
+	data = data[4:]
+	for len(data) >= 4 {
+		s := BMPStatsTLV{}
+		s.Type = binary.BigEndian.Uint16(data[0:2])
+		s.Length = binary.BigEndian.Uint16(data[2:4])
+
+		if s.Type == BMP_STAT_TYPE_ADJ_RIB_IN || s.Type == BMP_STAT_TYPE_LOC_RIB {
+			s.Value = binary.BigEndian.Uint64(data[4:12])
+		} else {
+			s.Value = uint64(binary.BigEndian.Uint32(data[4:8]))
+		}
+		body.Stats = append(body.Stats, s)
+		data = data[4+s.Length:]
+	}
+	return nil
+}
+
+type BMPTLV struct {
+	Type   uint16
+	Length uint16
+	Value  []byte
+}
+
+type BMPInitiation struct {
+	Info []BMPTLV
+}
+
+func (body *BMPInitiation) ParseBody(msg *BMPMessage, data []byte) error {
+	for len(data) >= 4 {
+		tlv := BMPTLV{}
+		tlv.Type = binary.BigEndian.Uint16(data[0:2])
+		tlv.Length = binary.BigEndian.Uint16(data[2:4])
+		tlv.Value = data[4 : 4+tlv.Length]
+
+		body.Info = append(body.Info, tlv)
+		data = data[4+tlv.Length:]
+	}
+	return nil
+}
+
+type BMPTermination struct {
+	Info []BMPTLV
+}
+
+func (body *BMPTermination) ParseBody(msg *BMPMessage, data []byte) error {
+	for len(data) >= 4 {
+		tlv := BMPTLV{}
+		tlv.Type = binary.BigEndian.Uint16(data[0:2])
+		tlv.Length = binary.BigEndian.Uint16(data[2:4])
+		tlv.Value = data[4 : 4+tlv.Length]
+
+		body.Info = append(body.Info, tlv)
+		data = data[4+tlv.Length:]
+	}
+	return nil
+}
+
+type BMPBody interface {
+	ParseBody(*BMPMessage, []byte) error
+}
+
+type BMPMessage struct {
+	Header     BMPHeader
+	PeerHeader BMPPeerHeader
+	Body       BMPBody
+}
+
+func (msg *BMPMessage) Len() int {
+	return int(msg.Header.Length)
+}
+
+const (
+	BMP_MSG_ROUTE_MONITORING = iota
+	BMP_MSG_STATISTICS_REPORT
+	BMP_MSG_PEER_DOWN_NOTIFICATION
+	BMP_MSG_PEER_UP_NOTIFICATION
+	BMP_MSG_INITIATION
+	BMP_MSG_TERMINATION
+)
+
+// move somewhere else
+func ReadBMPMessage(conn net.Conn) (*BMPMessage, error) {
+	buf := make([]byte, BMP_HEADER_SIZE)
+	for offset := 0; offset < BMP_HEADER_SIZE; {
+		rlen, err := conn.Read(buf[offset:])
+		if err != nil {
+			return nil, err
+		}
+		offset += rlen
+	}
+
+	h := BMPHeader{}
+	err := h.DecodeFromBytes(buf)
+	if err != nil {
+		return nil, err
+	}
+
+	data := make([]byte, h.Len())
+	copy(data, buf)
+	data = data[BMP_HEADER_SIZE:]
+	for offset := 0; offset < h.Len()-BMP_HEADER_SIZE; {
+		rlen, err := conn.Read(data[offset:])
+		if err != nil {
+			return nil, err
+		}
+		offset += rlen
+	}
+	msg := &BMPMessage{Header: h}
+
+	switch msg.Header.Type {
+	case BMP_MSG_ROUTE_MONITORING:
+		msg.Body = &BMPRouteMonitoring{}
+	case BMP_MSG_STATISTICS_REPORT:
+		msg.Body = &BMPStatisticsReport{}
+	case BMP_MSG_PEER_DOWN_NOTIFICATION:
+		msg.Body = &BMPPeerDownNotification{}
+	case BMP_MSG_PEER_UP_NOTIFICATION:
+		msg.Body = &BMPPeerUpNotification{}
+	case BMP_MSG_INITIATION:
+		msg.Body = &BMPInitiation{}
+	case BMP_MSG_TERMINATION:
+		msg.Body = &BMPTermination{}
+	}
+
+	if msg.Header.Type != BMP_MSG_INITIATION && msg.Header.Type != BMP_MSG_INITIATION {
+		msg.PeerHeader.DecodeFromBytes(data)
+		data = data[42:]
+	}
+
+	err = msg.Body.ParseBody(msg, data)
+	if err != nil {
+		return nil, err
+	}
+	return msg, nil
+}
+
+func ParseBMPMessage(data []byte) (*BMPMessage, error) {
+	msg := &BMPMessage{}
+	msg.Header.DecodeFromBytes(data)
+	data = data[6:msg.Header.Length]
+
+	switch msg.Header.Type {
+	case BMP_MSG_ROUTE_MONITORING:
+		msg.Body = &BMPRouteMonitoring{}
+	case BMP_MSG_STATISTICS_REPORT:
+		msg.Body = &BMPStatisticsReport{}
+	case BMP_MSG_PEER_DOWN_NOTIFICATION:
+		msg.Body = &BMPPeerDownNotification{}
+	case BMP_MSG_PEER_UP_NOTIFICATION:
+		msg.Body = &BMPPeerUpNotification{}
+	case BMP_MSG_INITIATION:
+		msg.Body = &BMPInitiation{}
+	case BMP_MSG_TERMINATION:
+		msg.Body = &BMPTermination{}
+	}
+
+	if msg.Header.Type != BMP_MSG_INITIATION && msg.Header.Type != BMP_MSG_INITIATION {
+		msg.PeerHeader.DecodeFromBytes(data)
+		data = data[42:]
+	}
+
+	err := msg.Body.ParseBody(msg, data)
+	if err != nil {
+		return nil, err
+	}
+	return msg, nil
+}
+
+type MessageError struct {
+	TypeCode    uint8
+	SubTypeCode uint8
+	Data        []byte
+	Message     string
+}
+
+func NewMessageError(typeCode, subTypeCode uint8, data []byte, msg string) error {
+	return &MessageError{
+		TypeCode:    typeCode,
+		SubTypeCode: subTypeCode,
+		Data:        data,
+		Message:     msg,
+	}
+}
+
+func (e *MessageError) Error() string {
+	return e.Message
+}