*: Notification support for BGP GR

implement draft-ietf-idr-bgp-gr-notification-07

Signed-off-by: Wataru Ishida <ishida.wataru@lab.ntt.co.jp>

6 files changed, 38 insertions, 8 deletions

diff --git a/config/bgp_configs.go b/config/bgp_configs.go
index 17ae937d..f56a3750 100644
--- a/config/bgp_configs.go
+++ b/config/bgp_configs.go
@@ -3549,6 +3549,9 @@ type GracefulRestartState struct {
 	Mode Mode `mapstructure:"mode"`
 	// original -> gobgp:deferral-time
 	DeferralTime uint16 `mapstructure:"deferral-time"`
+	// original -> gobgp:notification-enabled
+	//gobgp:notification-enabled's original type is boolean
+	NotificationEnabled bool `mapstructure:"notification-enabled"`
 }
 
 func (lhs *GracefulRestartState) Equal(rhs *GracefulRestartState) bool {
@@ -3582,6 +3585,9 @@ func (lhs *GracefulRestartState) Equal(rhs *GracefulRestartState) bool {
 	if lhs.DeferralTime != rhs.DeferralTime {
 		return false
 	}
+	if lhs.NotificationEnabled != rhs.NotificationEnabled {
+		return false
+	}
 	return true
 }
 
@@ -3600,6 +3606,9 @@ type GracefulRestartConfig struct {
 	HelperOnly bool `mapstructure:"helper-only"`
 	// original -> gobgp:deferral-time
 	DeferralTime uint16 `mapstructure:"deferral-time"`
+	// original -> gobgp:notification-enabled
+	//gobgp:notification-enabled's original type is boolean
+	NotificationEnabled bool `mapstructure:"notification-enabled"`
 }
 
 func (lhs *GracefulRestartConfig) Equal(rhs *GracefulRestartConfig) bool {
@@ -3621,6 +3630,9 @@ func (lhs *GracefulRestartConfig) Equal(rhs *GracefulRestartConfig) bool {
 	if lhs.DeferralTime != rhs.DeferralTime {
 		return false
 	}
+	if lhs.NotificationEnabled != rhs.NotificationEnabled {
+		return false
+	}
 	return true
 }
 
diff --git a/packet/bgp/bgp.go b/packet/bgp/bgp.go
index 916a5f69..b14eb8a5 100644
--- a/packet/bgp/bgp.go
+++ b/packet/bgp/bgp.go
@@ -426,11 +426,14 @@ func (c *CapGracefulRestart) MarshalJSON() ([]byte, error) {
 	})
 }
 
-func NewCapGracefulRestart(restarting bool, time uint16, tuples []*CapGracefulRestartTuple) *CapGracefulRestart {
+func NewCapGracefulRestart(restarting, notification bool, time uint16, tuples []*CapGracefulRestartTuple) *CapGracefulRestart {
 	flags := 0
 	if restarting {
 		flags = 0x08
 	}
+	if notification {
+		flags |= 0x04
+	}
 	return &CapGracefulRestart{
 		DefaultParameterCapability: DefaultParameterCapability{
 			CapCode: BGP_CAP_GRACEFUL_RESTART,
@@ -3914,6 +3917,7 @@ const (
 	BGP_ERROR_SUB_OTHER_CONFIGURATION_CHANGE
 	BGP_ERROR_SUB_CONNECTION_COLLISION_RESOLUTION
 	BGP_ERROR_SUB_OUT_OF_RESOURCES
+	BGP_ERROR_SUB_HARD_RESET //draft-ietf-idr-bgp-gr-notification-07
 )
 
 // NOTIFICATION Error Subcode for BGP_ERROR_ROUTE_REFRESH
diff --git a/packet/bgp/helper.go b/packet/bgp/helper.go
index 423361b1..1a06db1e 100644
--- a/packet/bgp/helper.go
+++ b/packet/bgp/helper.go
@@ -26,7 +26,7 @@ func NewTestBGPOpenMessage() *BGPMessage {
 		[]ParameterCapabilityInterface{NewCapMultiProtocol(RF_IPv4_UC)})
 	g := &CapGracefulRestartTuple{4, 2, 3}
 	p3 := NewOptionParameterCapability(
-		[]ParameterCapabilityInterface{NewCapGracefulRestart(false, 100,
+		[]ParameterCapabilityInterface{NewCapGracefulRestart(false, true, 100,
 			[]*CapGracefulRestartTuple{g})})
 	p4 := NewOptionParameterCapability(
 		[]ParameterCapabilityInterface{NewCapFourOctetASNumber(100000)})
diff --git a/server/fsm.go b/server/fsm.go
index 5ac3e6a2..d86a5ff1 100644
--- a/server/fsm.go
+++ b/server/fsm.go
@@ -47,6 +47,7 @@ const (
 	FSM_NEW_CONNECTION          = "new-connection"
 	FSM_OPEN_MSG_RECEIVED       = "open-msg-received"
 	FSM_OPEN_MSG_NEGOTIATED     = "open-msg-negotiated"
+	FSM_HARD_RESET              = "hard-reset"
 )
 
 type FsmMsgType int
@@ -544,7 +545,8 @@ func capabilitiesFromConfig(pConf *config.Neighbor) []bgp.ParameterCapabilityInt
 			}
 		}
 		time := c.RestartTime
-		caps = append(caps, bgp.NewCapGracefulRestart(restarting, time, tuples))
+		notification := c.NotificationEnabled
+		caps = append(caps, bgp.NewCapGracefulRestart(restarting, notification, time, tuples))
 	}
 	return caps
 }
@@ -693,8 +695,11 @@ func (h *FSMHandler) recvMessageWithError() (*FsmMsg, error) {
 					"Subcode": body.ErrorSubcode,
 					"Data":    body.Data,
 				}).Warn("received notification")
-
-				sendToErrorCh(FsmStateReason(fmt.Sprintf("%s %s", FSM_NOTIFICATION_RECV, bgp.NewNotificationErrorCode(body.ErrorCode, body.ErrorSubcode).String())))
+				if body.ErrorCode == bgp.BGP_ERROR_CEASE && body.ErrorSubcode == bgp.BGP_ERROR_SUB_HARD_RESET {
+					sendToErrorCh(FSM_HARD_RESET)
+				} else {
+					sendToErrorCh(FsmStateReason(fmt.Sprintf("%s %s", FSM_NOTIFICATION_RECV, bgp.NewNotificationErrorCode(body.ErrorCode, body.ErrorSubcode).String())))
+				}
 				return nil, nil
 			}
 		}
@@ -847,7 +852,7 @@ func (h *FSMHandler) opensent() (bgp.FSMState, FsmStateReason) {
 						// To re-establish the session with its peer, the Restarting Speaker
 						// MUST set the "Restart State" bit in the Graceful Restart Capability
 						// of the OPEN message.
-						if fsm.pConf.GracefulRestart.State.PeerRestarting && cap.Flags != 0x08 {
+						if fsm.pConf.GracefulRestart.State.PeerRestarting && cap.Flags&0x08 == 0 {
 							log.WithFields(log.Fields{
 								"Topic": "Peer",
 								"Key":   fsm.pConf.Config.NeighborAddress,
@@ -857,6 +862,9 @@ func (h *FSMHandler) opensent() (bgp.FSMState, FsmStateReason) {
 							h.conn.Close()
 							return bgp.BGP_FSM_IDLE, FSM_INVALID_MSG
 						}
+						if fsm.pConf.GracefulRestart.Config.NotificationEnabled && cap.Flags&0x04 > 0 {
+							fsm.pConf.GracefulRestart.State.NotificationEnabled = true
+						}
 					}
 
 					msg := bgp.NewBGPKeepAliveMessage()
@@ -1170,7 +1178,7 @@ func (h *FSMHandler) established() (bgp.FSMState, FsmStateReason) {
 		case err := <-h.errorCh:
 			h.conn.Close()
 			h.t.Kill(nil)
-			if s := fsm.pConf.GracefulRestart.State; s.Enabled && (err == FSM_READ_FAILED || err == FSM_WRITE_FAILED) {
+			if s := fsm.pConf.GracefulRestart.State; s.Enabled && ((s.NotificationEnabled && err != FSM_HARD_RESET) || err == FSM_READ_FAILED || err == FSM_WRITE_FAILED) {
 				err = FSM_GRACEFUL_RESTART
 				log.WithFields(log.Fields{
 					"Topic": "Peer",
diff --git a/server/fsm_test.go b/server/fsm_test.go
index f973fb76..5e31c67a 100644
--- a/server/fsm_test.go
+++ b/server/fsm_test.go
@@ -311,7 +311,7 @@ func open() *bgp.BGPMessage {
 		[]bgp.ParameterCapabilityInterface{bgp.NewCapMultiProtocol(bgp.RF_IPv4_UC)})
 	g := &bgp.CapGracefulRestartTuple{4, 2, 3}
 	p3 := bgp.NewOptionParameterCapability(
-		[]bgp.ParameterCapabilityInterface{bgp.NewCapGracefulRestart(true, 100,
+		[]bgp.ParameterCapabilityInterface{bgp.NewCapGracefulRestart(true, true, 100,
 			[]*bgp.CapGracefulRestartTuple{g})})
 	p4 := bgp.NewOptionParameterCapability(
 		[]bgp.ParameterCapabilityInterface{bgp.NewCapFourOctetASNumber(100000)})
diff --git a/tools/pyang_plugins/gobgp.yang b/tools/pyang_plugins/gobgp.yang
index a4f8e335..72c766ab 100644
--- a/tools/pyang_plugins/gobgp.yang
+++ b/tools/pyang_plugins/gobgp.yang
@@ -705,6 +705,9 @@ module gobgp {
     leaf deferral-time {
       type uint16;
     }
+    leaf notification-enabled {
+      type boolean;
+    }
   }
 
   augment "/bgp:bgp/bgp:neighbors/bgp:neighbor/bgp:graceful-restart/bgp:state" {
@@ -712,6 +715,9 @@ module gobgp {
     leaf deferral-time {
       type uint16;
     }
+    leaf notification-enabled {
+      type boolean;
+    }
   }
 
   augment "/bgp:bgp/bgp:peer-groups/bgp:peer-group" {