add DUID-UUID (#32)

2 files changed, 61 insertions, 6 deletions

diff --git a/dhcpv6/duid.go b/dhcpv6/duid.go
index 112412d..8572349 100644
--- a/dhcpv6/duid.go
+++ b/dhcpv6/duid.go
@@ -9,16 +9,19 @@ import (
 
 type DuidType uint16
 
+// DUID types
 const (
-	DUID_LLT DuidType = 1
-	DUID_EN  DuidType = 2
-	DUID_LL  DuidType = 3
+	DUID_LLT  DuidType = 1
+	DUID_EN   DuidType = 2
+	DUID_LL   DuidType = 3
+	DUID_UUID DuidType = 4
 )
 
 var DuidTypeToString = map[DuidType]string{
-	DUID_LL:  "DUID-LL",
-	DUID_LLT: "DUID-LLT",
-	DUID_EN:  "DUID-EN",
+	DUID_LL:   "DUID-LL",
+	DUID_LLT:  "DUID-LLT",
+	DUID_EN:   "DUID-EN",
+	DUID_UUID: "DUID-UUID",
 }
 
 type Duid struct {
@@ -28,6 +31,7 @@ type Duid struct {
 	LinkLayerAddr        []byte
 	EnterpriseNumber     uint32 // for DUID-EN. Ignored otherwise
 	EnterpriseIdentifier []byte // for DUID-EN. Ignored otherwise
+	Uuid                 []byte // for DUID-UUID. Ignored otherwise
 }
 
 func (d *Duid) Length() int {
@@ -37,6 +41,8 @@ func (d *Duid) Length() int {
 		return 4 + len(d.LinkLayerAddr)
 	} else if d.Type == DUID_EN {
 		return 6 + len(d.EnterpriseIdentifier)
+	} else if d.Type == DUID_UUID {
+		return 18
 	}
 	panic(fmt.Sprintf("Unknown DUID type: %v", d.Type))
 }
@@ -58,6 +64,10 @@ func (d *Duid) ToBytes() []byte {
 		binary.BigEndian.PutUint16(buf[0:2], uint16(d.Type))
 		binary.BigEndian.PutUint32(buf[2:6], d.EnterpriseNumber)
 		return append(buf, d.EnterpriseIdentifier...)
+	} else if d.Type == DUID_UUID {
+		buf := make([]byte, 2)
+		binary.BigEndian.PutUint16(buf[0:2], uint16(d.Type))
+		return append(buf, d.Uuid...)
 	}
 	panic(fmt.Sprintf("Unknown DUID type: %v", d.Type))
 }
@@ -108,6 +118,11 @@ func DuidFromBytes(data []byte) (*Duid, error) {
 		}
 		d.EnterpriseNumber = binary.BigEndian.Uint32(data[2:6])
 		d.EnterpriseIdentifier = data[6:]
+	} else if d.Type == DUID_UUID {
+		if len(data) != 18 {
+			return nil, fmt.Errorf("Invalid DUID-UUID length. Expected 18, got %v", len(data))
+		}
+		d.Uuid = data[2:18]
 	}
 	return &d, nil
 }
diff --git a/dhcpv6/duid_test.go b/dhcpv6/duid_test.go
new file mode 100644
index 0000000..23ce709
--- /dev/null
+++ b/dhcpv6/duid_test.go
@@ -0,0 +1,40 @@
+package dhcpv6
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestDuidUuid(t *testing.T) {
+	buf := []byte{
+		0x00, 0x04,                                                                                     // type
+		0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08, 0x00, 0x09, // uuid
+	}
+	duid, err := DuidFromBytes(buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if dt := duid.Type; dt != DUID_UUID {
+		t.Fatalf("Invalid Preferred Lifetime. Expected 4, got %d", dt)
+	}
+	if uuid := duid.Uuid; !bytes.Equal(uuid, buf[2:]) {
+		t.Fatalf("Invalid UUID. Expected %v, got %v", buf[2:], uuid)
+	}
+	if mac := duid.LinkLayerAddr; mac != nil {
+		t.Fatalf("Invalid MAC. Expected nil, got %v", mac)
+	}
+}
+
+func TestDuidUuidToBytes(t *testing.T) {
+	uuid := []byte{0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08, 0x00, 0x09}
+	expected := []byte{00, 04}
+	expected = append(expected, uuid...)
+	duid := Duid{
+		Type: DUID_UUID,
+		Uuid: uuid,
+	}
+	toBytes := duid.ToBytes()
+	if !bytes.Equal(toBytes, expected) {
+		t.Fatalf("Invalid ToBytes result. Expected %v, got %v", expected, toBytes)
+	}
+}