packet: fix addpath capability parser/serializer

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

2 files changed, 46 insertions, 19 deletions

diff --git a/packet/bgp/bgp.go b/packet/bgp/bgp.go
index 034a2bcb..a32ce069 100644
--- a/packet/bgp/bgp.go
+++ b/packet/bgp/bgp.go
@@ -590,52 +590,79 @@ func (m BGPAddPathMode) String() string {
 	}
 }
 
-type CapAddPath struct {
-	DefaultParameterCapability
+type CapAddPathTuple struct {
 	RouteFamily RouteFamily
 	Mode        BGPAddPathMode
 }
 
+func (t *CapAddPathTuple) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		RouteFamily RouteFamily `json:"family"`
+		Mode        uint8       `json:"mode"`
+	}{
+		RouteFamily: t.RouteFamily,
+		Mode:        uint8(t.Mode),
+	})
+}
+
+func NewCapAddPathTuple(family RouteFamily, mode BGPAddPathMode) *CapAddPathTuple {
+	return &CapAddPathTuple{
+		RouteFamily: family,
+		Mode:        mode,
+	}
+}
+
+type CapAddPath struct {
+	DefaultParameterCapability
+	Tuples []*CapAddPathTuple
+}
+
 func (c *CapAddPath) DecodeFromBytes(data []byte) error {
 	c.DefaultParameterCapability.DecodeFromBytes(data)
 	data = data[2:]
 	if len(data) < 4 {
 		return NewMessageError(BGP_ERROR_OPEN_MESSAGE_ERROR, BGP_ERROR_SUB_UNSUPPORTED_CAPABILITY, nil, "Not all CapabilityAddPath bytes available")
 	}
-	c.RouteFamily = AfiSafiToRouteFamily(binary.BigEndian.Uint16(data[:2]), data[2])
-	c.Mode = BGPAddPathMode(data[3])
+	c.Tuples = []*CapAddPathTuple{}
+	for len(data) >= 4 {
+		t := &CapAddPathTuple{
+			RouteFamily: AfiSafiToRouteFamily(binary.BigEndian.Uint16(data[:2]), data[2]),
+			Mode:        BGPAddPathMode(data[3]),
+		}
+		c.Tuples = append(c.Tuples, t)
+		data = data[4:]
+	}
 	return nil
 }
 
 func (c *CapAddPath) Serialize() ([]byte, error) {
-	buf := make([]byte, 4)
-	afi, safi := RouteFamilyToAfiSafi(c.RouteFamily)
-	binary.BigEndian.PutUint16(buf, afi)
-	buf[2] = safi
-	buf[3] = byte(c.Mode)
+	buf := make([]byte, len(c.Tuples)*4)
+	for i, t := range c.Tuples {
+		afi, safi := RouteFamilyToAfiSafi(t.RouteFamily)
+		binary.BigEndian.PutUint16(buf[i*4:i*4+2], afi)
+		buf[i*4+2] = safi
+		buf[i*4+3] = byte(t.Mode)
+	}
 	c.DefaultParameterCapability.CapValue = buf
 	return c.DefaultParameterCapability.Serialize()
 }
 
 func (c *CapAddPath) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		Code  BGPCapabilityCode `json:"code"`
-		Value RouteFamily       `json:"value"`
-		Mode  BGPAddPathMode    `json:"mode"`
+		Code   BGPCapabilityCode  `json:"code"`
+		Tuples []*CapAddPathTuple `json:"tuples"`
 	}{
-		Code:  c.Code(),
-		Value: c.RouteFamily,
-		Mode:  c.Mode,
+		Code:   c.Code(),
+		Tuples: c.Tuples,
 	})
 }
 
-func NewCapAddPath(rf RouteFamily, mode BGPAddPathMode) *CapAddPath {
+func NewCapAddPath(tuples []*CapAddPathTuple) *CapAddPath {
 	return &CapAddPath{
 		DefaultParameterCapability: DefaultParameterCapability{
 			CapCode: BGP_CAP_ADD_PATH,
 		},
-		RouteFamily: rf,
-		Mode:        mode,
+		Tuples: tuples,
 	}
 }
 
diff --git a/packet/bgp/helper.go b/packet/bgp/helper.go
index 1a06db1e..d97095f9 100644
--- a/packet/bgp/helper.go
+++ b/packet/bgp/helper.go
@@ -31,7 +31,7 @@ func NewTestBGPOpenMessage() *BGPMessage {
 	p4 := NewOptionParameterCapability(
 		[]ParameterCapabilityInterface{NewCapFourOctetASNumber(100000)})
 	p5 := NewOptionParameterCapability(
-		[]ParameterCapabilityInterface{NewCapAddPath(RF_IPv4_UC, BGP_ADD_PATH_BOTH)})
+		[]ParameterCapabilityInterface{NewCapAddPath([]*CapAddPathTuple{NewCapAddPathTuple(RF_IPv4_UC, BGP_ADD_PATH_BOTH)})})
 	return NewBGPOpenMessage(11033, 303, "100.4.10.3",
 		[]OptionParameterInterface{p1, p2, p3, p4, p5})
 }