2 files changed, 51 insertions, 0 deletions
diff --git a/dhcpv6/option_interfaceid.go b/dhcpv6/option_interfaceid.go
new file mode 100644
index 0000000..4ba83f5
--- /dev/null
+++ b/dhcpv6/option_interfaceid.go
@@ -0,0 +1,49 @@
+package dhcpv6
+
+// This module defines the OptInterfaceId structure.
+// https://www.ietf.org/rfc/rfc3315.txt
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+type OptInterfaceId struct {
+	interfaceId []byte
+}
+
+func (op *OptInterfaceId) Code() OptionCode {
+	return OPTION_INTERFACE_ID
+}
+
+func (op *OptInterfaceId) ToBytes() []byte {
+	buf := make([]byte, 4)
+	binary.BigEndian.PutUint16(buf[0:2], uint16(OPTION_INTERFACE_ID))
+	binary.BigEndian.PutUint16(buf[2:4], 2)
+	buf = append(buf, op.interfaceId...)
+	return buf
+}
+
+func (op *OptInterfaceId) InterfaceID() []byte {
+	return op.interfaceId
+}
+
+func (op *OptInterfaceId) SetInterfaceID(interfaceId []byte) {
+	op.interfaceId = append([]byte(nil), interfaceId...)
+}
+
+func (op *OptInterfaceId) Length() int {
+	return 4 + len(op.interfaceId)
+}
+
+func (op *OptInterfaceId) String() string {
+	return fmt.Sprintf("OptInterfaceId{interfaceid=%v}", op.interfaceId)
+}
+
+// build an OptInterfaceId structure from a sequence of bytes.
+// The input data does not include option code and length bytes.
+func ParseOptInterfaceId(data []byte) (*OptInterfaceId, error) {
+	opt := OptInterfaceId{}
+	opt.interfaceId = append([]byte(nil), data[4:]...)
+	return &opt, nil
+}
diff --git a/dhcpv6/options.go b/dhcpv6/options.go
index d5d299f..4ac5977 100644
--- a/dhcpv6/options.go
+++ b/dhcpv6/options.go
@@ -92,6 +92,8 @@ func ParseOption(dataStart []byte) (Option, error) {
 		opt, err = ParseOptRelayMsg(optData)
 	case OPTION_REMOTE_ID:
 		opt, err = ParseOptRemoteId(optData)
+	case OPTION_INTERFACE_ID:
+		opt, err = ParseOptInterfaceId(optData)
 	default:
 		opt = &OptionGeneric{OptionCode: code, OptionData: optData}
 	}