cli: Communication on Administrative Shutdown NOTIFICATION

This patch enable to send an arbitrary message on the Cease NOTIFICATION
message with "Administrative Shutdown" and "Administrative Reset" subcodes
with "--reason" option.

Usage:
  $ gobgp neighbor <neighbor address> shutdown --reason "some messages"
  $ gobgp neighbor <neighbor address> reset --reason "some messages"

Reference: https://tools.ietf.org/html/draft-ietf-idr-shutdown-04

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

2 files changed, 27 insertions, 7 deletions

diff --git a/server/server.go b/server/server.go
index 902b6c8a..38b65422 100644
--- a/server/server.go
+++ b/server/server.go
@@ -1765,7 +1765,7 @@ func (s *BgpServer) addrToPeers(addr string) (l []*Peer, err error) {
 	return []*Peer{peer}, nil
 }
 
-func (s *BgpServer) resetNeighbor(op, addr string, subcode uint8) error {
+func (s *BgpServer) resetNeighbor(op, addr string, subcode uint8, data []byte) error {
 	log.WithFields(log.Fields{
 		"Topic": "Operation",
 		"Key":   addr,
@@ -1773,7 +1773,7 @@ func (s *BgpServer) resetNeighbor(op, addr string, subcode uint8) error {
 
 	peers, err := s.addrToPeers(addr)
 	if err == nil {
-		m := bgp.NewBGPNotificationMessage(bgp.BGP_ERROR_CEASE, subcode, nil)
+		m := bgp.NewBGPNotificationMessage(bgp.BGP_ERROR_CEASE, subcode, data)
 		for _, peer := range peers {
 			sendFsmOutgoingMsg(peer, nil, m, false)
 		}
@@ -1781,15 +1781,15 @@ func (s *BgpServer) resetNeighbor(op, addr string, subcode uint8) error {
 	return err
 }
 
-func (s *BgpServer) ShutdownNeighbor(addr string) error {
+func (s *BgpServer) ShutdownNeighbor(addr, communication string) error {
 	return s.mgmtOperation(func() error {
-		return s.resetNeighbor("Neighbor shutdown", addr, bgp.BGP_ERROR_SUB_ADMINISTRATIVE_SHUTDOWN)
+		return s.resetNeighbor("Neighbor shutdown", addr, bgp.BGP_ERROR_SUB_ADMINISTRATIVE_SHUTDOWN, newAdministrativeCommunication(communication))
 	}, true)
 }
 
-func (s *BgpServer) ResetNeighbor(addr string) error {
+func (s *BgpServer) ResetNeighbor(addr, communication string) error {
 	return s.mgmtOperation(func() error {
-		err := s.resetNeighbor("Neighbor reset", addr, bgp.BGP_ERROR_SUB_ADMINISTRATIVE_RESET)
+		err := s.resetNeighbor("Neighbor reset", addr, bgp.BGP_ERROR_SUB_ADMINISTRATIVE_RESET, newAdministrativeCommunication(communication))
 		if err != nil {
 			return err
 		}
diff --git a/server/util.go b/server/util.go
index 43c85bc1..9e11a0a1 100644
--- a/server/util.go
+++ b/server/util.go
@@ -15,7 +15,10 @@
 
 package server
 
-import "github.com/eapache/channels"
+import (
+	"github.com/eapache/channels"
+	"github.com/osrg/gobgp/packet/bgp"
+)
 
 func cleanInfiniteChannel(ch *channels.InfiniteChannel) {
 	ch.Close()
@@ -23,3 +26,20 @@ func cleanInfiniteChannel(ch *channels.InfiniteChannel) {
 	for range ch.Out() {
 	}
 }
+
+// Returns the binary formatted Administrative Shutdown Communication from the
+// given string value.
+func newAdministrativeCommunication(communication string) (data []byte) {
+	if communication == "" {
+		return nil
+	}
+	com := []byte(communication)
+	if len(com) > bgp.BGP_ERROR_ADMINISTRATIVE_COMMUNICATION_MAX {
+		data = []byte{bgp.BGP_ERROR_ADMINISTRATIVE_COMMUNICATION_MAX}
+		data = append(data, com[:bgp.BGP_ERROR_ADMINISTRATIVE_COMMUNICATION_MAX]...)
+	} else {
+		data = []byte{byte(len(com))}
+		data = append(data, com...)
+	}
+	return data
+}