add OptVendorClass (#148)

1 files changed, 81 insertions, 0 deletions

diff --git a/dhcpv6/option_vendorclass.go b/dhcpv6/option_vendorclass.go
new file mode 100644
index 0000000..b920fa7
--- /dev/null
+++ b/dhcpv6/option_vendorclass.go
@@ -0,0 +1,81 @@
+package dhcpv6
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// OptVendorClass represents a DHCPv6 Vendor Class option
+type OptVendorClass struct {
+	EnterpriseNumber uint32
+	Data             [][]byte
+}
+
+// Code returns the option code
+func (op *OptVendorClass) Code() OptionCode {
+	return OptionVendorClass
+}
+
+// ToBytes serializes the option and returns it as a sequence of bytes
+func (op *OptVendorClass) ToBytes() []byte {
+	buf := make([]byte, 8)
+	binary.BigEndian.PutUint16(buf[0:2], uint16(OptionVendorClass))
+	binary.BigEndian.PutUint16(buf[2:4], uint16(op.Length()))
+	binary.BigEndian.PutUint32(buf[4:8], uint32(op.EnterpriseNumber))
+	u16 := make([]byte, 2)
+	for _, data := range op.Data {
+		binary.BigEndian.PutUint16(u16, uint16(len(data)))
+		buf = append(buf, u16...)
+		buf = append(buf, data...)
+	}
+	return buf
+}
+
+// Length returns the option length
+func (op *OptVendorClass) Length() int {
+	ret := 0
+	for _, data := range op.Data {
+		ret += 2 + len(data)
+	}
+	return 4 + ret
+}
+
+// String returns a string representation of the VendorClass data
+func (op *OptVendorClass) String() string {
+	vcStrings := make([]string, 0)
+	for _, data := range op.Data {
+		vcStrings = append(vcStrings, string(data))
+	}
+	return fmt.Sprintf("OptVendorClass{enterprisenum=%d, data=[%s]}", op.EnterpriseNumber, strings.Join(vcStrings, ", "))
+}
+
+// ParseOptVendorClass builds an OptVendorClass structure from a sequence of
+// bytes. The input data does not include option code and length bytes.
+func ParseOptVendorClass(data []byte) (*OptVendorClass, error) {
+	opt := OptVendorClass{}
+	if len(data) < 4 {
+		return nil, fmt.Errorf("Invalid vendor opts data length. Expected at least 4 bytes, got %v", len(data))
+	}
+	opt.EnterpriseNumber = binary.BigEndian.Uint32(data[:4])
+	data = data[4:]
+	for {
+		if len(data) == 0 {
+			break
+		}
+		if len(data) < 2 {
+			return nil, errors.New("ParseOptVendorClass: short data: missing length field")
+		}
+		vcLen := int(binary.BigEndian.Uint16(data[:2]))
+		if len(data) < vcLen+2 {
+			return nil, fmt.Errorf("ParseOptVendorClass: short data: less than %d bytes", vcLen+2)
+		}
+		opt.Data = append(opt.Data, data[2:vcLen+2])
+		data = data[2+vcLen:]
+	}
+	if len(opt.Data) < 1 {
+		return nil, errors.New("ParseOptVendorClass: at least one vendor class data is required")
+	}
+	return &opt, nil
+}