BGP-LS Problem:why cannot LsTLVIgpRouterID support length of 4 when decodeFromByte ?

[zhanggongc]

func (l *LsTLVIgpRouterID) DecodeFromBytes(data []byte) error { value, err := l.LsTLV.DecodeFromBytes(data) if err != nil { return err }

if l.Type != LS_TLV_IGP_ROUTER_ID {
	return malformedAttrListErr("Unexpected TLV type")
}

// https://tools.ietf.org/html/rfc7752#section-3.2.1.4
// 6, 7, and 8 are the only valid 

Why don't support length 4 ? but it can be 4 in RFC7752.. Misunderstanding or any other thinking ?

if len(value) < 6 || len(value) > 8 {
	return malformedAttrListErr("Incorrect IGP Router ID length")
}

l.RouterID = value

return nil

}

https://tools.ietf.org/html/rfc7752#section-3.2.1.4

[zhanggongc]

in order to support length of 4，I modify this code ,

but when gobgpd run, it report many errors:

[vasya4k]

You probably need to look into:

func (l *LsNodeNLRI) String() string {
	if l.LocalNodeDesc == nil {
		return "NODE { EMPTY }"
	}

	local := l.LocalNodeDesc.(*LsTLVNodeDescriptor).Extract()
	return fmt.Sprintf("NODE { AS:%v BGP-LS ID:%v %v %v:%v }", local.Asn, local.BGPLsID, local.IGPRouterID, l.ProtocolID.String(), l.Identifier)
}

The fmt.Sprintf most likely returns a a string which makes the below try to marshal malformed json.

func (l *LsAddrPrefix) MarshalJSON() ([]byte, error) {
	return json.Marshal(struct {
		Type   LsNLRIType `json:"type"`
		Length uint16     `json:"length"`
		NLRI   string     `json:"nlri"`
	}{
		l.Type,
		l.Length,
		l.String(),
	})
}