mrt: use on-wire original update data for mrt

bgpd parse on-wire original update data to construct BGPMessage object
and serialize it. Sometimes the both data is not idential. For
example, the original data sets the extended length for attribute even
if the length is less than 256.

This commit fixes the above issue.

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

4 files changed, 16 insertions, 4 deletions

diff --git a/packet/mrt.go b/packet/mrt.go
index 7c336684..15dbc839 100644
--- a/packet/mrt.go
+++ b/packet/mrt.go
@@ -641,8 +641,9 @@ func NewBGP4MPStateChange(peeras, localas uint32, intfindex uint16, peerip, loca
 
 type BGP4MPMessage struct {
 	*BGP4MPHeader
-	BGPMessage *BGPMessage
-	isLocal    bool
+	BGPMessage        *BGPMessage
+	BGPMessagePayload []byte
+	isLocal           bool
 }
 
 func (m *BGP4MPMessage) DecodeFromBytes(data []byte) error {
@@ -668,6 +669,9 @@ func (m *BGP4MPMessage) Serialize() ([]byte, error) {
 	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
diff --git a/server/fsm.go b/server/fsm.go
index 9377b5a8..15d935bb 100644
--- a/server/fsm.go
+++ b/server/fsm.go
@@ -43,6 +43,7 @@ type FsmMsg struct {
 	MsgData   interface{}
 	PathList  []*table.Path
 	timestamp time.Time
+	payload   []byte
 }
 
 const (
@@ -471,6 +472,7 @@ func (h *FSMHandler) recvMessageWithError() error {
 		return err
 	}
 
+	now := time.Now()
 	m, err := bgp.ParseBGPBody(hd, bodyBuf)
 	if err == nil {
 		h.fsm.bgpMessageStateUpdate(m.Header.Type, true)
@@ -482,7 +484,7 @@ func (h *FSMHandler) recvMessageWithError() error {
 		MsgType:   FSM_MSG_BGP_MESSAGE,
 		MsgSrc:    h.fsm.pConf.NeighborConfig.NeighborAddress.String(),
 		MsgDst:    h.fsm.pConf.Transport.TransportConfig.LocalAddress.String(),
-		timestamp: time.Now(),
+		timestamp: now,
 	}
 	if err != nil {
 		log.WithFields(log.Fields{
@@ -514,6 +516,9 @@ func (h *FSMHandler) recvMessageWithError() error {
 					h.fsm.peer.ApplyPolicy(table.POLICY_DIRECTION_IN, fmsg.PathList)
 					policyMutex.RUnlock()
 				}
+				fmsg.payload = make([]byte, len(headerBuf)+len(bodyBuf))
+				copy(fmsg.payload, headerBuf)
+				copy(fmsg.payload[len(headerBuf):], bodyBuf)
 				fallthrough
 			case bgp.BGP_MSG_KEEPALIVE:
 				// if the lenght of h.holdTimerResetCh
diff --git a/server/server.go b/server/server.go
index 52d917ac..ecdbc8c2 100644
--- a/server/server.go
+++ b/server/server.go
@@ -801,6 +801,7 @@ func (server *BgpServer) handleFSMMessage(peer *Peer, e *FsmMsg, incoming chan *
 						localAddress: net.ParseIP(l),
 						fourBytesAs:  y,
 						timestamp:    e.timestamp,
+						payload:      e.payload,
 					}
 					for _, ch := range listener {
 						bm := &broadcastWatcherMsg{
diff --git a/server/watcher.go b/server/watcher.go
index 73c3f251..d186e9cf 100644
--- a/server/watcher.go
+++ b/server/watcher.go
@@ -64,6 +64,7 @@ type watcherEventUpdateMsg struct {
 	localAddress net.IP
 	fourBytesAs  bool
 	timestamp    time.Time
+	payload      []byte
 }
 
 type watcher interface {
@@ -115,7 +116,8 @@ func (w *mrtWatcher) loop() error {
 		write := func(ev watcherEvent) {
 			m := ev.(*watcherEventUpdateMsg)
 			subtype := bgp.MESSAGE_AS4
-			mp := bgp.NewBGP4MPMessage(m.peerAS, m.localAS, 0, m.peerAddress.String(), m.localAddress.String(), m.fourBytesAs, m.message)
+			mp := bgp.NewBGP4MPMessage(m.peerAS, m.localAS, 0, m.peerAddress.String(), m.localAddress.String(), m.fourBytesAs, nil)
+			mp.BGPMessagePayload = m.payload
 			if m.fourBytesAs == false {
 				subtype = bgp.MESSAGE
 			}