1 files changed, 155 insertions, 0 deletions
diff --git a/dhcpv6/option_ntp_server.go b/dhcpv6/option_ntp_server.go
new file mode 100644
index 0000000..a7aafb7
--- /dev/null
+++ b/dhcpv6/option_ntp_server.go
@@ -0,0 +1,155 @@
+package dhcpv6
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/insomniacslk/dhcp/rfc1035label"
+	"github.com/u-root/uio/uio"
+)
+
+// NTPSuboptionSrvAddr is NTP_SUBOPTION_SRV_ADDR according to RFC 5908.
+type NTPSuboptionSrvAddr net.IP
+
+// Code returns the suboption code.
+func (n *NTPSuboptionSrvAddr) Code() OptionCode {
+	return NTPSuboptionSrvAddrCode
+}
+
+// ToBytes returns the byte serialization of the suboption.
+func (n *NTPSuboptionSrvAddr) ToBytes() []byte {
+	buf := uio.NewBigEndianBuffer(nil)
+	buf.Write16(uint16(NTPSuboptionSrvAddrCode))
+	buf.Write16(uint16(net.IPv6len))
+	buf.WriteBytes(net.IP(*n).To16())
+	return buf.Data()
+}
+
+func (n *NTPSuboptionSrvAddr) String() string {
+	return fmt.Sprintf("Server Address: %s", net.IP(*n).String())
+}
+
+// NTPSuboptionMCAddr is NTP_SUBOPTION_MC_ADDR according to RFC 5908.
+type NTPSuboptionMCAddr net.IP
+
+// Code returns the suboption code.
+func (n *NTPSuboptionMCAddr) Code() OptionCode {
+	return NTPSuboptionMCAddrCode
+}
+
+// ToBytes returns the byte serialization of the suboption.
+func (n *NTPSuboptionMCAddr) ToBytes() []byte {
+	buf := uio.NewBigEndianBuffer(nil)
+	buf.Write16(uint16(NTPSuboptionMCAddrCode))
+	buf.Write16(uint16(net.IPv6len))
+	buf.WriteBytes(net.IP(*n).To16())
+	return buf.Data()
+}
+
+func (n *NTPSuboptionMCAddr) String() string {
+	return fmt.Sprintf("Multicast Address: %s", net.IP(*n).String())
+}
+
+// NTPSuboptionSrvFQDN is NTP_SUBOPTION_SRV_FQDN according to RFC 5908.
+type NTPSuboptionSrvFQDN rfc1035label.Labels
+
+// Code returns the suboption code.
+func (n *NTPSuboptionSrvFQDN) Code() OptionCode {
+	return NTPSuboptionSrvFQDNCode
+}
+
+// ToBytes returns the byte serialization of the suboption.
+func (n *NTPSuboptionSrvFQDN) ToBytes() []byte {
+	buf := uio.NewBigEndianBuffer(nil)
+	buf.Write16(uint16(NTPSuboptionSrvFQDNCode))
+	l := rfc1035label.Labels(*n)
+	buf.Write16(uint16(l.Length()))
+	buf.WriteBytes(l.ToBytes())
+	return buf.Data()
+}
+
+func (n *NTPSuboptionSrvFQDN) String() string {
+	l := rfc1035label.Labels(*n)
+	return fmt.Sprintf("Server FQDN: %s", l.String())
+}
+
+// NTPSuboptionSrvAddr is the value of NTP_SUBOPTION_SRV_ADDR according to RFC 5908.
+const (
+	NTPSuboptionSrvAddrCode = OptionCode(1)
+	NTPSuboptionMCAddrCode  = OptionCode(2)
+	NTPSuboptionSrvFQDNCode = OptionCode(3)
+)
+
+// parseNTPSuboption implements the OptionParser interface.
+func parseNTPSuboption(code OptionCode, data []byte) (Option, error) {
+	//var o Options
+	buf := uio.NewBigEndianBuffer(data)
+	length := len(data)
+	data, err := buf.ReadN(length)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read %d bytes for suboption: %w", length, err)
+	}
+	switch code {
+	case NTPSuboptionSrvAddrCode, NTPSuboptionMCAddrCode:
+		if length != net.IPv6len {
+			return nil, fmt.Errorf("invalid suboption length, want %d, got %d", net.IPv6len, length)
+		}
+		var so Option
+		switch code {
+		case NTPSuboptionSrvAddrCode:
+			sos := NTPSuboptionSrvAddr(data)
+			so = &sos
+		case NTPSuboptionMCAddrCode:
+			som := NTPSuboptionMCAddr(data)
+			so = &som
+		}
+		return so, nil
+	case NTPSuboptionSrvFQDNCode:
+		l, err := rfc1035label.FromBytes(data)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse rfc1035 labels: %w", err)
+		}
+		// TODO according to rfc3315, this label must not be compressed.
+		// Need to add support for compression detection to the
+		// `rfc1035label` package in order to do that.
+		so := NTPSuboptionSrvFQDN(*l)
+		return &so, nil
+	default:
+		gopt := OptionGeneric{OptionCode: code, OptionData: data}
+		return &gopt, nil
+	}
+}
+
+// ParseOptNTPServer parses a sequence of bytes into an OptNTPServer object.
+func ParseOptNTPServer(data []byte) (*OptNTPServer, error) {
+	var so Options
+	if err := so.FromBytesWithParser(data, parseNTPSuboption); err != nil {
+		return nil, err
+	}
+	return &OptNTPServer{
+		Suboptions: so,
+	}, nil
+}
+
+// OptNTPServer is an option NTP server as defined by RFC 5908.
+type OptNTPServer struct {
+	Suboptions Options
+}
+
+// Code returns the option code
+func (op *OptNTPServer) Code() OptionCode {
+	return OptionNTPServer
+}
+
+// ToBytes returns the option serialized to bytes.
+func (op *OptNTPServer) ToBytes() []byte {
+	buf := uio.NewBigEndianBuffer(nil)
+	for _, so := range op.Suboptions {
+		buf.WriteBytes(so.ToBytes())
+	}
+	return buf.Data()
+}
+
+func (op *OptNTPServer) String() string {
+	return fmt.Sprintf("NTP: %v", op.Suboptions)
+}