packet: create mrt package

move mrt stuff from bgp to mrt package.

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

1 files changed, 799 insertions, 0 deletions

diff --git a/packet/mrt/mrt.go b/packet/mrt/mrt.go
new file mode 100644
index 00000000..041a2802
--- /dev/null
+++ b/packet/mrt/mrt.go
@@ -0,0 +1,799 @@
+// Copyright (C) 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 mrt
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"github.com/osrg/gobgp/packet/bgp"
+	"math"
+	"net"
+	"time"
+)
+
+const (
+	MRT_COMMON_HEADER_LEN = 12
+)
+
+type MRTType uint16
+
+const (
+	NULL         MRTType = 0  // deprecated
+	START        MRTType = 1  // deprecated
+	DIE          MRTType = 2  // deprecated
+	I_AM_DEAD    MRTType = 3  // deprecated
+	PEER_DOWN    MRTType = 4  // deprecated
+	BGP          MRTType = 5  // deprecated
+	RIP          MRTType = 6  // deprecated
+	IDRP         MRTType = 7  // deprecated
+	RIPNG        MRTType = 8  // deprecated
+	BGP4PLUS     MRTType = 9  // deprecated
+	BGP4PLUS01   MRTType = 10 // deprecated
+	OSPFv2       MRTType = 11
+	TABLE_DUMP   MRTType = 12
+	TABLE_DUMPv2 MRTType = 13
+	BGP4MP       MRTType = 16
+	BGP4MP_ET    MRTType = 17
+	ISIS         MRTType = 32
+	ISIS_ET      MRTType = 33
+	OSPFv3       MRTType = 48
+	OSPFv3_ET    MRTType = 49
+)
+
+type MRTSubTyper interface {
+	ToUint16() uint16
+}
+
+type MRTSubTypeTableDumpv2 uint16
+
+const (
+	PEER_INDEX_TABLE   MRTSubTypeTableDumpv2 = 1
+	RIB_IPV4_UNICAST   MRTSubTypeTableDumpv2 = 2
+	RIB_IPV4_MULTICAST MRTSubTypeTableDumpv2 = 3
+	RIB_IPV6_UNICAST   MRTSubTypeTableDumpv2 = 4
+	RIB_IPV6_MULTICAST MRTSubTypeTableDumpv2 = 5
+	RIB_GENERIC        MRTSubTypeTableDumpv2 = 6
+)
+
+func (t MRTSubTypeTableDumpv2) ToUint16() uint16 {
+	return uint16(t)
+}
+
+type MRTSubTypeBGP4MP uint16
+
+const (
+	STATE_CHANGE      MRTSubTypeBGP4MP = 0
+	MESSAGE           MRTSubTypeBGP4MP = 1
+	MESSAGE_AS4       MRTSubTypeBGP4MP = 4
+	STATE_CHANGE_AS4  MRTSubTypeBGP4MP = 5
+	MESSAGE_LOCAL     MRTSubTypeBGP4MP = 6
+	MESSAGE_AS4_LOCAL MRTSubTypeBGP4MP = 7
+)
+
+func (t MRTSubTypeBGP4MP) ToUint16() uint16 {
+	return uint16(t)
+}
+
+type BGPState uint16
+
+const (
+	IDLE        BGPState = 1
+	CONNECT     BGPState = 2
+	ACTIVE      BGPState = 3
+	OPENSENT    BGPState = 4
+	OPENCONFIRM BGPState = 5
+	ESTABLISHED BGPState = 6
+)
+
+func packValues(values []interface{}) ([]byte, error) {
+	b := new(bytes.Buffer)
+	for _, v := range values {
+		err := binary.Write(b, binary.BigEndian, v)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return b.Bytes(), nil
+}
+
+type MRTHeader struct {
+	Timestamp uint32
+	Type      MRTType
+	SubType   uint16
+	Len       uint32
+}
+
+func (h *MRTHeader) DecodeFromBytes(data []byte) error {
+	if len(data) < MRT_COMMON_HEADER_LEN {
+		return fmt.Errorf("not all MRTHeader bytes are available. expected: %d, actual: %d", MRT_COMMON_HEADER_LEN, len(data))
+	}
+	h.Timestamp = binary.BigEndian.Uint32(data[:4])
+	h.Type = MRTType(binary.BigEndian.Uint16(data[4:6]))
+	h.SubType = binary.BigEndian.Uint16(data[6:8])
+	h.Len = binary.BigEndian.Uint32(data[8:12])
+	return nil
+}
+
+func (h *MRTHeader) Serialize() ([]byte, error) {
+	return packValues([]interface{}{h.Timestamp, h.Type, h.SubType, h.Len})
+}
+
+func NewMRTHeader(timestamp uint32, t MRTType, subtype MRTSubTyper, l uint32) (*MRTHeader, error) {
+	return &MRTHeader{
+		Timestamp: timestamp,
+		Type:      t,
+		SubType:   subtype.ToUint16(),
+		Len:       l,
+	}, nil
+}
+
+func (h *MRTHeader) GetTime() time.Time {
+	t := int64(h.Timestamp)
+	return time.Unix(t, 0)
+}
+
+type MRTMessage struct {
+	Header MRTHeader
+	Body   Body
+}
+
+func (m *MRTMessage) Serialize() ([]byte, error) {
+	buf, err := m.Body.Serialize()
+	if err != nil {
+		return nil, err
+	}
+	m.Header.Len = uint32(len(buf))
+	bbuf, err := m.Header.Serialize()
+	if err != nil {
+		return nil, err
+	}
+	return append(bbuf, buf...), nil
+}
+
+func NewMRTMessage(timestamp uint32, t MRTType, subtype MRTSubTyper, body Body) (*MRTMessage, error) {
+	header, err := NewMRTHeader(timestamp, t, subtype, 0)
+	if err != nil {
+		return nil, err
+	}
+	return &MRTMessage{
+		Header: *header,
+		Body:   body,
+	}, nil
+}
+
+type Body interface {
+	DecodeFromBytes([]byte) error
+	Serialize() ([]byte, error)
+}
+
+type Peer struct {
+	Type      uint8
+	BgpId     net.IP
+	IpAddress net.IP
+	AS        uint32
+}
+
+func (p *Peer) DecodeFromBytes(data []byte) ([]byte, error) {
+	notAllBytesAvail := fmt.Errorf("not all Peer bytes are available")
+	if len(data) < 5 {
+		return nil, notAllBytesAvail
+	}
+	p.Type = uint8(data[0])
+	p.BgpId = net.IP(data[1:5])
+	data = data[5:]
+
+	if p.Type&1 > 0 {
+		if len(data) < 16 {
+			return nil, notAllBytesAvail
+		}
+		p.IpAddress = net.IP(data[:16])
+		data = data[16:]
+	} else {
+		if len(data) < 4 {
+			return nil, notAllBytesAvail
+		}
+		p.IpAddress = net.IP(data[:4])
+		data = data[4:]
+	}
+
+	if p.Type&(1<<1) > 0 {
+		if len(data) < 4 {
+			return nil, notAllBytesAvail
+		}
+		p.AS = binary.BigEndian.Uint32(data[:4])
+		data = data[4:]
+	} else {
+		if len(data) < 2 {
+			return nil, notAllBytesAvail
+		}
+		p.AS = uint32(binary.BigEndian.Uint16(data[:2]))
+		data = data[2:]
+	}
+
+	return data, nil
+}
+
+func (p *Peer) Serialize() ([]byte, error) {
+	var err error
+	var bbuf []byte
+	buf := make([]byte, 5)
+	buf[0] = uint8(p.Type)
+	copy(buf[1:], p.BgpId.To4())
+	if p.Type&1 > 0 {
+		buf = append(buf, p.IpAddress.To16()...)
+	} else {
+		buf = append(buf, p.IpAddress.To4()...)
+	}
+	if p.Type&(1<<1) > 0 {
+		bbuf, err = packValues([]interface{}{p.AS})
+	} else {
+		if p.AS > uint32(math.MaxUint16) {
+			return nil, fmt.Errorf("AS number is beyond 2 octet. %d > %d", p.AS, math.MaxUint16)
+		}
+		bbuf, err = packValues([]interface{}{uint16(p.AS)})
+	}
+	if err != nil {
+		return nil, err
+	}
+	return append(buf, bbuf...), nil
+}
+
+func NewPeer(bgpid string, ipaddr string, asn uint32, isAS4 bool) *Peer {
+	t := 0
+	addr := net.ParseIP(ipaddr).To4()
+	if addr == nil {
+		t |= 1
+		addr = net.ParseIP(ipaddr).To16()
+	}
+	if isAS4 {
+		t |= (1 << 1)
+	}
+	return &Peer{
+		Type:      uint8(t),
+		BgpId:     net.ParseIP(bgpid).To4(),
+		IpAddress: addr,
+		AS:        asn,
+	}
+}
+
+func (p *Peer) String() string {
+	return fmt.Sprintf("PEER ENTRY: ID [%s] Addr [%s] AS [%d]", p.BgpId, p.IpAddress, p.AS)
+}
+
+type PeerIndexTable struct {
+	CollectorBgpId net.IP
+	ViewName       string
+	Peers          []*Peer
+}
+
+func (t *PeerIndexTable) DecodeFromBytes(data []byte) error {
+	notAllBytesAvail := fmt.Errorf("not all PeerIndexTable bytes are available")
+	if len(data) < 6 {
+		return notAllBytesAvail
+	}
+	t.CollectorBgpId = net.IP(data[:4])
+	viewLen := binary.BigEndian.Uint16(data[4:6])
+	if len(data) < 6+int(viewLen) {
+		return notAllBytesAvail
+	}
+	t.ViewName = string(data[6 : 6+viewLen])
+
+	data = data[6+viewLen:]
+
+	if len(data) < 2 {
+		return notAllBytesAvail
+	}
+	peerNum := binary.BigEndian.Uint16(data[:2])
+	data = data[2:]
+	t.Peers = make([]*Peer, 0, peerNum)
+	var err error
+	for i := 0; i < int(peerNum); i++ {
+		p := &Peer{}
+		data, err = p.DecodeFromBytes(data)
+		if err != nil {
+			return err
+		}
+		t.Peers = append(t.Peers, p)
+	}
+
+	return nil
+}
+
+func (t *PeerIndexTable) Serialize() ([]byte, error) {
+	buf := make([]byte, 8+len(t.ViewName))
+	copy(buf, t.CollectorBgpId.To4())
+	binary.BigEndian.PutUint16(buf[4:], uint16(len(t.ViewName)))
+	copy(buf[6:], t.ViewName)
+	binary.BigEndian.PutUint16(buf[6+len(t.ViewName):], uint16(len(t.Peers)))
+	for _, peer := range t.Peers {
+		bbuf, err := peer.Serialize()
+		if err != nil {
+			return nil, err
+		}
+		buf = append(buf, bbuf...)
+	}
+	return buf, nil
+}
+
+func NewPeerIndexTable(bgpid string, viewname string, peers []*Peer) *PeerIndexTable {
+	return &PeerIndexTable{
+		CollectorBgpId: net.ParseIP(bgpid).To4(),
+		ViewName:       viewname,
+		Peers:          peers,
+	}
+}
+
+func (t *PeerIndexTable) String() string {
+	return fmt.Sprintf("PEER_INDEX_TABLE: CollectorBgpId [%s] ViewName [%s] Peers [%s]", t.CollectorBgpId, t.ViewName, t.Peers)
+}
+
+type RibEntry struct {
+	PeerIndex      uint16
+	OriginatedTime uint32
+	PathAttributes []bgp.PathAttributeInterface
+}
+
+func (e *RibEntry) DecodeFromBytes(data []byte) ([]byte, error) {
+	notAllBytesAvail := fmt.Errorf("not all RibEntry bytes are available")
+	if len(data) < 8 {
+		return nil, notAllBytesAvail
+	}
+	e.PeerIndex = binary.BigEndian.Uint16(data[:2])
+	e.OriginatedTime = binary.BigEndian.Uint32(data[2:6])
+	totalLen := binary.BigEndian.Uint16(data[6:8])
+	data = data[8:]
+	for attrLen := totalLen; attrLen > 0; {
+		p, err := bgp.GetPathAttribute(data)
+		if err != nil {
+			return nil, err
+		}
+		err = p.DecodeFromBytes(data)
+		if err != nil {
+			return nil, err
+		}
+		attrLen -= uint16(p.Len())
+		if len(data) < p.Len() {
+			return nil, notAllBytesAvail
+		}
+		data = data[p.Len():]
+		e.PathAttributes = append(e.PathAttributes, p)
+	}
+	return data, nil
+}
+
+func (e *RibEntry) Serialize() ([]byte, error) {
+	buf := make([]byte, 8)
+	binary.BigEndian.PutUint16(buf, e.PeerIndex)
+	binary.BigEndian.PutUint32(buf[2:], e.OriginatedTime)
+	totalLen := 0
+	binary.BigEndian.PutUint16(buf[6:], uint16(totalLen))
+	for _, pattr := range e.PathAttributes {
+		// TODO special modification is needed for MP_REACH_NLRI
+		// but also Quagga doesn't implement this.
+		//
+		// RFC 6396 4.3.4
+		// There is one exception to the encoding of BGP attributes for the BGP
+		// MP_REACH_NLRI attribute (BGP Type Code 14).
+		// Since the AFI, SAFI, and NLRI information is already encoded
+		// in the RIB Entry Header or RIB_GENERIC Entry Header,
+		// only the Next Hop Address Length and Next Hop Address fields are included.
+
+		bbuf, err := pattr.Serialize()
+		if err != nil {
+			return nil, err
+		}
+		buf = append(buf, bbuf...)
+		totalLen += len(bbuf)
+	}
+	binary.BigEndian.PutUint16(buf[6:], uint16(totalLen))
+	return buf, nil
+}
+
+func NewRibEntry(index uint16, time uint32, pathattrs []bgp.PathAttributeInterface) *RibEntry {
+	return &RibEntry{
+		PeerIndex:      index,
+		OriginatedTime: time,
+		PathAttributes: pathattrs,
+	}
+}
+
+func (e *RibEntry) String() string {
+	return fmt.Sprintf("RIB_ENTRY: PeerIndex [%d] OriginatedTime [%d] PathAttrs [%v]", e.PeerIndex, e.OriginatedTime, e.PathAttributes)
+}
+
+type Rib struct {
+	SequenceNumber uint32
+	Prefix         bgp.AddrPrefixInterface
+	Entries        []*RibEntry
+	RouteFamily    bgp.RouteFamily
+}
+
+func (u *Rib) DecodeFromBytes(data []byte) error {
+	if len(data) < 4 {
+		return fmt.Errorf("Not all RibIpv4Unicast message bytes available")
+	}
+	u.SequenceNumber = binary.BigEndian.Uint32(data[:4])
+	data = data[4:]
+	afi, safi := bgp.RouteFamilyToAfiSafi(u.RouteFamily)
+	if afi == 0 && safi == 0 {
+		afi = binary.BigEndian.Uint16(data[:2])
+		safi = data[2]
+		data = data[3:]
+	}
+	prefix, err := bgp.NewPrefixFromRouteFamily(afi, safi)
+	if err != nil {
+		return err
+	}
+	err = prefix.DecodeFromBytes(data)
+	if err != nil {
+		return err
+	}
+	u.Prefix = prefix
+	data = data[prefix.Len():]
+	entryNum := binary.BigEndian.Uint16(data[:2])
+	data = data[2:]
+	u.Entries = make([]*RibEntry, 0, entryNum)
+	for i := 0; i < int(entryNum); i++ {
+		e := &RibEntry{}
+		data, err = e.DecodeFromBytes(data)
+		if err != nil {
+			return err
+		}
+		u.Entries = append(u.Entries, e)
+	}
+	return nil
+}
+
+func (u *Rib) Serialize() ([]byte, error) {
+	buf := make([]byte, 4)
+	binary.BigEndian.PutUint32(buf, u.SequenceNumber)
+	rf := bgp.AfiSafiToRouteFamily(u.Prefix.AFI(), u.Prefix.SAFI())
+	switch rf {
+	case bgp.RF_IPv4_UC, bgp.RF_IPv4_MC, bgp.RF_IPv6_UC, bgp.RF_IPv6_MC:
+	default:
+		bbuf := make([]byte, 0, 2)
+		binary.BigEndian.PutUint16(bbuf, u.Prefix.AFI())
+		buf = append(buf, bbuf...)
+		buf = append(buf, u.Prefix.SAFI())
+	}
+	bbuf, err := u.Prefix.Serialize()
+	if err != nil {
+		return nil, err
+	}
+	buf = append(buf, bbuf...)
+	bbuf, err = packValues([]interface{}{uint16(len(u.Entries))})
+	if err != nil {
+		return nil, err
+	}
+	buf = append(buf, bbuf...)
+	for _, entry := range u.Entries {
+		bbuf, err = entry.Serialize()
+		if err != nil {
+			return nil, err
+		}
+		buf = append(buf, bbuf...)
+	}
+	return buf, nil
+}
+
+func NewRib(seq uint32, prefix bgp.AddrPrefixInterface, entries []*RibEntry) *Rib {
+	rf := bgp.AfiSafiToRouteFamily(prefix.AFI(), prefix.SAFI())
+	return &Rib{
+		SequenceNumber: seq,
+		Prefix:         prefix,
+		Entries:        entries,
+		RouteFamily:    rf,
+	}
+}
+
+func (u *Rib) String() string {
+	return fmt.Sprintf("RIB: Seq [%d] Prefix [%s] Entries [%s]", u.SequenceNumber, u.Prefix, u.Entries)
+}
+
+type BGP4MPHeader struct {
+	PeerAS         uint32
+	LocalAS        uint32
+	InterfaceIndex uint16
+	AddressFamily  uint16
+	PeerIpAddress  net.IP
+	LocalIpAddress net.IP
+	isAS4          bool
+}
+
+func (m *BGP4MPHeader) decodeFromBytes(data []byte) ([]byte, error) {
+	if m.isAS4 && len(data) < 8 {
+		return nil, fmt.Errorf("Not all BGP4MPMessageAS4 bytes available")
+	} else if !m.isAS4 && len(data) < 4 {
+		return nil, fmt.Errorf("Not all BGP4MPMessageAS bytes available")
+	}
+
+	if m.isAS4 {
+		m.PeerAS = binary.BigEndian.Uint32(data[:4])
+		m.LocalAS = binary.BigEndian.Uint32(data[4:8])
+		data = data[8:]
+	} else {
+		m.PeerAS = uint32(binary.BigEndian.Uint16(data[:2]))
+		m.LocalAS = uint32(binary.BigEndian.Uint16(data[2:4]))
+		data = data[4:]
+	}
+	m.InterfaceIndex = binary.BigEndian.Uint16(data[:2])
+	m.AddressFamily = binary.BigEndian.Uint16(data[2:4])
+	switch m.AddressFamily {
+	case bgp.AFI_IP:
+		m.PeerIpAddress = net.IP(data[4:8]).To4()
+		m.LocalIpAddress = net.IP(data[8:12]).To4()
+		data = data[12:]
+	case bgp.AFI_IP6:
+		m.PeerIpAddress = net.IP(data[4:20])
+		m.LocalIpAddress = net.IP(data[20:36])
+		data = data[36:]
+	default:
+		return nil, fmt.Errorf("unsupported address family: %d", m.AddressFamily)
+	}
+	return data, nil
+}
+
+func (m *BGP4MPHeader) serialize() ([]byte, error) {
+	var values []interface{}
+	if m.isAS4 {
+		values = []interface{}{m.PeerAS, m.LocalAS, m.InterfaceIndex, m.AddressFamily}
+	} else {
+		values = []interface{}{uint16(m.PeerAS), uint16(m.LocalAS), m.InterfaceIndex, m.AddressFamily}
+	}
+	buf, err := packValues(values)
+	if err != nil {
+		return nil, err
+	}
+	var bbuf []byte
+	switch m.AddressFamily {
+	case bgp.AFI_IP:
+		bbuf = make([]byte, 8)
+		copy(bbuf, m.PeerIpAddress.To4())
+		copy(bbuf[4:], m.LocalIpAddress.To4())
+	case bgp.AFI_IP6:
+		bbuf = make([]byte, 32)
+		copy(bbuf, m.PeerIpAddress)
+		copy(bbuf[16:], m.LocalIpAddress)
+	default:
+		return nil, fmt.Errorf("unsupported address family: %d", m.AddressFamily)
+	}
+	return append(buf, bbuf...), nil
+}
+
+func newBGP4MPHeader(peeras, localas uint32, intfindex uint16, peerip, localip string, isAS4 bool) (*BGP4MPHeader, error) {
+	var af uint16
+	paddr := net.ParseIP(peerip).To4()
+	laddr := net.ParseIP(localip).To4()
+	if paddr != nil && laddr != nil {
+		af = bgp.AFI_IP
+	} else {
+		paddr = net.ParseIP(peerip).To16()
+		laddr = net.ParseIP(localip).To16()
+		if paddr != nil && laddr != nil {
+			af = bgp.AFI_IP6
+		} else {
+			return nil, fmt.Errorf("Peer IP Address and Local IP Address must have the same address family")
+		}
+	}
+	return &BGP4MPHeader{
+		PeerAS:         peeras,
+		LocalAS:        localas,
+		InterfaceIndex: intfindex,
+		AddressFamily:  af,
+		PeerIpAddress:  paddr,
+		LocalIpAddress: laddr,
+		isAS4:          isAS4,
+	}, nil
+}
+
+type BGP4MPStateChange struct {
+	*BGP4MPHeader
+	OldState BGPState
+	NewState BGPState
+}
+
+func (m *BGP4MPStateChange) DecodeFromBytes(data []byte) error {
+	rest, err := m.decodeFromBytes(data)
+	if err != nil {
+		return err
+	}
+	if len(rest) < 4 {
+		return fmt.Errorf("Not all BGP4MPStateChange bytes available")
+	}
+	m.OldState = BGPState(binary.BigEndian.Uint16(rest[:2]))
+	m.NewState = BGPState(binary.BigEndian.Uint16(rest[2:4]))
+	return nil
+}
+
+func (m *BGP4MPStateChange) Serialize() ([]byte, error) {
+	buf, err := m.serialize()
+	if err != nil {
+		return nil, err
+	}
+	bbuf, err := packValues([]interface{}{m.OldState, m.NewState})
+	if err != nil {
+		return nil, err
+	}
+	return append(buf, bbuf...), nil
+}
+
+func NewBGP4MPStateChange(peeras, localas uint32, intfindex uint16, peerip, localip string, isAS4 bool, oldstate, newstate BGPState) *BGP4MPStateChange {
+	header, _ := newBGP4MPHeader(peeras, localas, intfindex, peerip, localip, isAS4)
+	return &BGP4MPStateChange{
+		BGP4MPHeader: header,
+		OldState:     oldstate,
+		NewState:     newstate,
+	}
+}
+
+type BGP4MPMessage struct {
+	*BGP4MPHeader
+	BGPMessage        *bgp.BGPMessage
+	BGPMessagePayload []byte
+	isLocal           bool
+}
+
+func (m *BGP4MPMessage) DecodeFromBytes(data []byte) error {
+	rest, err := m.decodeFromBytes(data)
+	if err != nil {
+		return err
+	}
+
+	if len(rest) < bgp.BGP_HEADER_LENGTH {
+		return fmt.Errorf("Not all BGP4MPMessageAS4 bytes available")
+	}
+
+	msg, err := bgp.ParseBGPMessage(rest)
+	if err != nil {
+		return err
+	}
+	m.BGPMessage = msg
+	return nil
+}
+
+func (m *BGP4MPMessage) Serialize() ([]byte, error) {
+	buf, err := m.serialize()
+	if err != nil {
+		return nil, err
+	}
+	if m.BGPMessagePayload != nil {
+		return append(buf, m.BGPMessagePayload...), nil
+	}
+	bbuf, err := m.BGPMessage.Serialize()
+	if err != nil {
+		return nil, err
+	}
+	return append(buf, bbuf...), nil
+}
+
+func NewBGP4MPMessage(peeras, localas uint32, intfindex uint16, peerip, localip string, isAS4 bool, msg *bgp.BGPMessage) *BGP4MPMessage {
+	header, _ := newBGP4MPHeader(peeras, localas, intfindex, peerip, localip, isAS4)
+	return &BGP4MPMessage{
+		BGP4MPHeader: header,
+		BGPMessage:   msg,
+	}
+}
+
+func NewBGP4MPMessageLocal(peeras, localas uint32, intfindex uint16, peerip, localip string, isAS4 bool, msg *bgp.BGPMessage) *BGP4MPMessage {
+	header, _ := newBGP4MPHeader(peeras, localas, intfindex, peerip, localip, isAS4)
+	return &BGP4MPMessage{
+		BGP4MPHeader: header,
+		BGPMessage:   msg,
+		isLocal:      true,
+	}
+}
+
+func (m *BGP4MPMessage) String() string {
+	title := "BGP4MP_MSG"
+	if m.isAS4 {
+		title += "_AS4"
+	}
+	if m.isLocal {
+		title += "_LOCAL"
+	}
+	return fmt.Sprintf("%s: PeerAS [%d] LocalAS [%d] InterfaceIndex [%d] PeerIP [%s] LocalIP [%s] BGPMessage [%v]", title, m.PeerAS, m.LocalAS, m.InterfaceIndex, m.PeerIpAddress, m.LocalIpAddress, m.BGPMessage)
+}
+
+//This function can be passed into a bufio.Scanner.Split() to read buffered mrt msgs
+func SplitMrt(data []byte, atEOF bool) (advance int, token []byte, err error) {
+	if atEOF && len(data) == 0 {
+		return 0, nil, nil
+	}
+	if cap(data) < MRT_COMMON_HEADER_LEN { // read more
+		return 0, nil, nil
+	}
+	//this reads the data
+	hdr := &MRTHeader{}
+	errh := hdr.DecodeFromBytes(data[:MRT_COMMON_HEADER_LEN])
+	if errh != nil {
+		return 0, nil, errh
+	}
+	totlen := int(hdr.Len + MRT_COMMON_HEADER_LEN)
+	if len(data) < totlen { //need to read more
+		return 0, nil, nil
+	}
+	return totlen, data[0:totlen], nil
+}
+
+func ParseMRTBody(h *MRTHeader, data []byte) (*MRTMessage, error) {
+	if len(data) < int(h.Len) {
+		return nil, fmt.Errorf("Not all MRT message bytes available. expected: %d, actual: %d", int(h.Len), len(data))
+	}
+	msg := &MRTMessage{Header: *h}
+	switch h.Type {
+	case TABLE_DUMPv2:
+		subType := MRTSubTypeTableDumpv2(h.SubType)
+		rf := bgp.RouteFamily(0)
+		switch subType {
+		case PEER_INDEX_TABLE:
+			msg.Body = &PeerIndexTable{}
+		case RIB_IPV4_UNICAST:
+			rf = bgp.RF_IPv4_UC
+		case RIB_IPV4_MULTICAST:
+			rf = bgp.RF_IPv4_MC
+		case RIB_IPV6_UNICAST:
+			rf = bgp.RF_IPv6_UC
+		case RIB_IPV6_MULTICAST:
+			rf = bgp.RF_IPv6_MC
+		case RIB_GENERIC:
+		default:
+			return nil, fmt.Errorf("unsupported table dumpv2 subtype: %v\n", subType)
+		}
+
+		if subType != PEER_INDEX_TABLE {
+			msg.Body = &Rib{
+				RouteFamily: rf,
+			}
+		}
+	case BGP4MP:
+		subType := MRTSubTypeBGP4MP(h.SubType)
+		isAS4 := true
+		switch subType {
+		case STATE_CHANGE:
+			isAS4 = false
+			fallthrough
+		case STATE_CHANGE_AS4:
+			msg.Body = &BGP4MPStateChange{
+				BGP4MPHeader: &BGP4MPHeader{isAS4: isAS4},
+			}
+		case MESSAGE:
+			isAS4 = false
+			fallthrough
+		case MESSAGE_AS4:
+			msg.Body = &BGP4MPMessage{
+				BGP4MPHeader: &BGP4MPHeader{isAS4: isAS4},
+			}
+		case MESSAGE_LOCAL:
+			isAS4 = false
+			fallthrough
+		case MESSAGE_AS4_LOCAL:
+			msg.Body = &BGP4MPMessage{
+				BGP4MPHeader: &BGP4MPHeader{isAS4: isAS4},
+				isLocal:      true,
+			}
+		default:
+			return nil, fmt.Errorf("unsupported bgp4mp subtype: %v\n", subType)
+		}
+	default:
+		return nil, fmt.Errorf("unsupported type: %v\n", h.Type)
+	}
+	err := msg.Body.DecodeFromBytes(data)
+	if err != nil {
+		return nil, err
+	}
+	return msg, nil
+}