3 files changed, 87 insertions, 9 deletions
diff --git a/dhcpv6/dhcpv6message.go b/dhcpv6/dhcpv6message.go
index 8368d6c..cd8ff61 100644
--- a/dhcpv6/dhcpv6message.go
+++ b/dhcpv6/dhcpv6message.go
@@ -152,15 +152,8 @@ func NewRequestFromAdvertise(advertise DHCPv6) (DHCPv6, error) {
 		},
 	}
 	req.AddOption(&nii)
-	// add OPTION_CLIENT_ARCH_TYPE
-	// TODO implement OptionClientArchType
-	cat := OptionGeneric{
-		OptionCode: OPTION_CLIENT_ARCH_TYPE,
-		OptionData: []byte{
-			0, // Intel - see rfc4578
-			7, // EFI BC
-		},
-	}
+	cat := OptClientArchType{}
+	cat.SetArchType(EFI_BC)
 	req.AddOption(&cat)
 	// add OPTION_VENDOR_CLASS, only if present in the original request
 	// TODO implement OptionVendorClass
diff --git a/dhcpv6/option_archtype.go b/dhcpv6/option_archtype.go
new file mode 100644
index 0000000..6ed13f8
--- /dev/null
+++ b/dhcpv6/option_archtype.go
@@ -0,0 +1,83 @@
+package dhcpv6
+
+// This module defines the OptClientArchType structure.
+// https://www.ietf.org/rfc/rfc5970.txt
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+type ArchType uint16
+
+const (
+	INTEL_X86PC ArchType = iota
+	NEC_PC98
+	EFI_ITANIUM
+	DEC_ALPHA
+	ARC_X86
+	INTEL_LEAN_CLIENT
+	EFI_IA32
+	EFI_BC
+	EFI_XSCALE
+	EFI_X86_64
+)
+
+var ArchTypeToStringMap = map[ArchType]string{
+	INTEL_X86PC:       "Intel x86PC",
+	NEC_PC98:          "NEC/PC98",
+	EFI_ITANIUM:       "EFI Itanium",
+	DEC_ALPHA:         "DEC Alpha",
+	ARC_X86:           "Arc x86",
+	INTEL_LEAN_CLIENT: "Intel Lean Client",
+	EFI_IA32:          "EFI IA32",
+	EFI_BC:            "EFI BC",
+	EFI_XSCALE:        "EFI Xscale",
+	EFI_X86_64:        "EFI x86-64",
+}
+
+type OptClientArchType struct {
+	archType ArchType
+}
+
+func (op *OptClientArchType) Code() OptionCode {
+	return OPTION_CLIENT_ARCH_TYPE
+}
+
+func (op *OptClientArchType) ToBytes() []byte {
+	buf := make([]byte, 6)
+	binary.BigEndian.PutUint16(buf[0:2], uint16(OPTION_CLIENT_ARCH_TYPE))
+	binary.BigEndian.PutUint16(buf[2:4], 2)
+	return buf
+}
+
+func (op *OptClientArchType) ArchType() ArchType {
+	return op.archType
+}
+
+func (op *OptClientArchType) SetArchType(archType ArchType) {
+	op.archType = archType
+}
+
+func (op *OptClientArchType) Length() int {
+	return 2
+}
+
+func (op *OptClientArchType) String() string {
+	name, ok := ArchTypeToStringMap[op.archType]
+	if !ok {
+		name = "Unknown"
+	}
+	return fmt.Sprintf("OptClientArchType{archtype=%v}", name)
+}
+
+// build an OptClientArchType structure from a sequence of bytes.
+// The input data does not include option code and length bytes.
+func ParseOptClientArchType(data []byte) (*OptClientArchType, error) {
+	opt := OptClientArchType{}
+	if len(data) != 2 {
+		return nil, fmt.Errorf("Invalid arch type data length. Expected 2 bytes, got %v", len(data))
+	}
+	opt.archType = ArchType(binary.BigEndian.Uint16(data))
+	return &opt, nil
+}
diff --git a/dhcpv6/options.go b/dhcpv6/options.go
index 4ac5977..0268d22 100644
--- a/dhcpv6/options.go
+++ b/dhcpv6/options.go
@@ -94,6 +94,8 @@ func ParseOption(dataStart []byte) (Option, error) {
 		opt, err = ParseOptRemoteId(optData)
 	case OPTION_INTERFACE_ID:
 		opt, err = ParseOptInterfaceId(optData)
+	case OPTION_CLIENT_ARCH_TYPE:
+		opt, err = ParseOptClientArchType(optData)
 	default:
 		opt = &OptionGeneric{OptionCode: code, OptionData: optData}
 	}