server/fsm: Logging Administrative Shutdown Communication

This patch enable to log the body of the Cease NOTIFICATION message
with "Administrative Shutdown" and "Administrative Reset" subcodes.

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>

2 files changed, 57 insertions, 13 deletions

diff --git a/server/fsm.go b/server/fsm.go
index c72f7f24..a8ca047a 100644
--- a/server/fsm.go
+++ b/server/fsm.go
@@ -696,13 +696,26 @@ func (h *FSMHandler) recvMessageWithError() (*FsmMsg, error) {
 				}
 			case bgp.BGP_MSG_NOTIFICATION:
 				body := m.Body.(*bgp.BGPNotification)
-				log.WithFields(log.Fields{
-					"Topic":   "Peer",
-					"Key":     h.fsm.pConf.Config.NeighborAddress,
-					"Code":    body.ErrorCode,
-					"Subcode": body.ErrorSubcode,
-					"Data":    body.Data,
-				}).Warn("received notification")
+				if body.ErrorCode == bgp.BGP_ERROR_CEASE && (body.ErrorSubcode == bgp.BGP_ERROR_SUB_ADMINISTRATIVE_SHUTDOWN || body.ErrorSubcode == bgp.BGP_ERROR_SUB_ADMINISTRATIVE_RESET) {
+					communication, rest := decodeAdministrativeCommunication(body.Data)
+					log.WithFields(log.Fields{
+						"Topic":               "Peer",
+						"Key":                 h.fsm.pConf.Config.NeighborAddress,
+						"Code":                body.ErrorCode,
+						"Subcode":             body.ErrorSubcode,
+						"Communicated-Reason": communication,
+						"Data":                rest,
+					}).Warn("received notification")
+				} else {
+					log.WithFields(log.Fields{
+						"Topic":   "Peer",
+						"Key":     h.fsm.pConf.Config.NeighborAddress,
+						"Code":    body.ErrorCode,
+						"Subcode": body.ErrorSubcode,
+						"Data":    body.Data,
+					}).Warn("received notification")
+				}
+
 				if s := h.fsm.pConf.GracefulRestart.State; s.Enabled && s.NotificationEnabled && body.ErrorCode == bgp.BGP_ERROR_CEASE && body.ErrorSubcode == bgp.BGP_ERROR_SUB_HARD_RESET {
 					sendToErrorCh(FSM_HARD_RESET)
 				} else {
@@ -1097,13 +1110,28 @@ func (h *FSMHandler) sendMessageloop() error {
 
 		switch m.Header.Type {
 		case bgp.BGP_MSG_NOTIFICATION:
-			log.WithFields(log.Fields{
-				"Topic": "Peer",
-				"Key":   fsm.pConf.Config.NeighborAddress,
-				"State": fsm.state.String(),
-				"Data":  m,
-			}).Warn("sent notification")
 			body := m.Body.(*bgp.BGPNotification)
+			if body.ErrorCode == bgp.BGP_ERROR_CEASE && (body.ErrorSubcode == bgp.BGP_ERROR_SUB_ADMINISTRATIVE_SHUTDOWN || body.ErrorSubcode == bgp.BGP_ERROR_SUB_ADMINISTRATIVE_RESET) {
+				communication, rest := decodeAdministrativeCommunication(body.Data)
+				log.WithFields(log.Fields{
+					"Topic":               "Peer",
+					"Key":                 fsm.pConf.Config.NeighborAddress,
+					"State":               fsm.state.String(),
+					"Code":                body.ErrorCode,
+					"Subcode":             body.ErrorSubcode,
+					"Communicated-Reason": communication,
+					"Data":                rest,
+				}).Warn("sent notification")
+			} else {
+				log.WithFields(log.Fields{
+					"Topic":   "Peer",
+					"Key":     fsm.pConf.Config.NeighborAddress,
+					"State":   fsm.state.String(),
+					"Code":    body.ErrorCode,
+					"Subcode": body.ErrorSubcode,
+					"Data":    body.Data,
+				}).Warn("sent notification")
+			}
 			h.errorCh <- FsmStateReason(fmt.Sprintf("%s %s", FSM_NOTIFICATION_SENT, bgp.NewNotificationErrorCode(body.ErrorCode, body.ErrorSubcode).String()))
 			conn.Close()
 			return fmt.Errorf("closed")
diff --git a/server/util.go b/server/util.go
index 9e11a0a1..951d712c 100644
--- a/server/util.go
+++ b/server/util.go
@@ -43,3 +43,19 @@ func newAdministrativeCommunication(communication string) (data []byte) {
 	}
 	return data
 }
+
+// Parses the given NOTIFICATION message data as a binary value and returns
+// the Administrative Shutdown Communication in string and the rest binary.
+func decodeAdministrativeCommunication(data []byte) (string, []byte) {
+	if len(data) == 0 {
+		return "", data
+	}
+	communicationLen := int(data[0])
+	if communicationLen > bgp.BGP_ERROR_ADMINISTRATIVE_COMMUNICATION_MAX {
+		communicationLen = bgp.BGP_ERROR_ADMINISTRATIVE_COMMUNICATION_MAX
+	}
+	if communicationLen > len(data)+1 {
+		communicationLen = len(data) + 1
+	}
+	return string(data[1 : communicationLen+1]), data[communicationLen+1:]
+}