WIP [VOL-2811] - Incorporate preliminary onu-adapter-go code into opencord repo

- reason "discovery-mibsync-complete" reached (via full MibUpload only, received data won't be stored yet)
- first review comments of patchset #4 considered
 (please have a look into our inline-comments in Gerrit to know more about the current state)
- no refactoring done yet

Change-Id: Iac47817f8ce4bd28dd8132f530b0570d57ae99b8
Signed-off-by: Holger Hildebrandt <holger.hildebrandt@adtran.com>
diff --git a/vendor/github.com/google/gopacket/layers/dhcpv6.go b/vendor/github.com/google/gopacket/layers/dhcpv6.go
new file mode 100644
index 0000000..052b394
--- /dev/null
+++ b/vendor/github.com/google/gopacket/layers/dhcpv6.go
@@ -0,0 +1,341 @@
+// Copyright 2018 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"net"
+
+	"github.com/google/gopacket"
+)
+
+// DHCPv6MsgType represents a DHCPv6 operation
+type DHCPv6MsgType byte
+
+// Constants that represent DHCP operations
+const (
+	DHCPv6MsgTypeUnspecified DHCPv6MsgType = iota
+	DHCPv6MsgTypeSolicit
+	DHCPv6MsgTypeAdverstise
+	DHCPv6MsgTypeRequest
+	DHCPv6MsgTypeConfirm
+	DHCPv6MsgTypeRenew
+	DHCPv6MsgTypeRebind
+	DHCPv6MsgTypeReply
+	DHCPv6MsgTypeRelease
+	DHCPv6MsgTypeDecline
+	DHCPv6MsgTypeReconfigure
+	DHCPv6MsgTypeInformationRequest
+	DHCPv6MsgTypeRelayForward
+	DHCPv6MsgTypeRelayReply
+)
+
+// String returns a string version of a DHCPv6MsgType.
+func (o DHCPv6MsgType) String() string {
+	switch o {
+	case DHCPv6MsgTypeUnspecified:
+		return "Unspecified"
+	case DHCPv6MsgTypeSolicit:
+		return "Solicit"
+	case DHCPv6MsgTypeAdverstise:
+		return "Adverstise"
+	case DHCPv6MsgTypeRequest:
+		return "Request"
+	case DHCPv6MsgTypeConfirm:
+		return "Confirm"
+	case DHCPv6MsgTypeRenew:
+		return "Renew"
+	case DHCPv6MsgTypeRebind:
+		return "Rebind"
+	case DHCPv6MsgTypeReply:
+		return "Reply"
+	case DHCPv6MsgTypeRelease:
+		return "Release"
+	case DHCPv6MsgTypeDecline:
+		return "Decline"
+	case DHCPv6MsgTypeReconfigure:
+		return "Reconfigure"
+	case DHCPv6MsgTypeInformationRequest:
+		return "InformationRequest"
+	case DHCPv6MsgTypeRelayForward:
+		return "RelayForward"
+	case DHCPv6MsgTypeRelayReply:
+		return "RelayReply"
+	default:
+		return "Unknown"
+	}
+}
+
+// DHCPv6 contains data for a single DHCP packet.
+type DHCPv6 struct {
+	BaseLayer
+	MsgType       DHCPv6MsgType
+	HopCount      uint8
+	LinkAddr      net.IP
+	PeerAddr      net.IP
+	TransactionID []byte
+	Options       DHCPv6Options
+}
+
+// LayerType returns gopacket.LayerTypeDHCPv6
+func (d *DHCPv6) LayerType() gopacket.LayerType { return LayerTypeDHCPv6 }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (d *DHCPv6) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	d.BaseLayer = BaseLayer{Contents: data}
+	d.Options = d.Options[:0]
+	d.MsgType = DHCPv6MsgType(data[0])
+
+	offset := 0
+	if d.MsgType == DHCPv6MsgTypeRelayForward || d.MsgType == DHCPv6MsgTypeRelayReply {
+		d.HopCount = data[1]
+		d.LinkAddr = net.IP(data[2:18])
+		d.PeerAddr = net.IP(data[18:34])
+		offset = 34
+	} else {
+		d.TransactionID = data[1:4]
+		offset = 4
+	}
+
+	stop := len(data)
+	for offset < stop {
+		o := DHCPv6Option{}
+		if err := o.decode(data[offset:]); err != nil {
+			return err
+		}
+		d.Options = append(d.Options, o)
+		offset += int(o.Length) + 4 // 2 from option code, 2 from option length
+	}
+
+	return nil
+}
+
+// Len returns the length of a DHCPv6 packet.
+func (d *DHCPv6) Len() int {
+	n := 1
+	if d.MsgType == DHCPv6MsgTypeRelayForward || d.MsgType == DHCPv6MsgTypeRelayReply {
+		n += 33
+	} else {
+		n += 3
+	}
+
+	for _, o := range d.Options {
+		n += int(o.Length) + 4 // 2 from option code, 2 from option length
+	}
+
+	return n
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (d *DHCPv6) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	plen := int(d.Len())
+
+	data, err := b.PrependBytes(plen)
+	if err != nil {
+		return err
+	}
+
+	offset := 0
+	data[0] = byte(d.MsgType)
+	if d.MsgType == DHCPv6MsgTypeRelayForward || d.MsgType == DHCPv6MsgTypeRelayReply {
+		data[1] = byte(d.HopCount)
+		copy(data[2:18], d.LinkAddr.To16())
+		copy(data[18:34], d.PeerAddr.To16())
+		offset = 34
+	} else {
+		copy(data[1:4], d.TransactionID)
+		offset = 4
+	}
+
+	if len(d.Options) > 0 {
+		for _, o := range d.Options {
+			if err := o.encode(data[offset:], opts); err != nil {
+				return err
+			}
+			offset += int(o.Length) + 4 // 2 from option code, 2 from option length
+		}
+	}
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (d *DHCPv6) CanDecode() gopacket.LayerClass {
+	return LayerTypeDHCPv6
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (d *DHCPv6) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+func decodeDHCPv6(data []byte, p gopacket.PacketBuilder) error {
+	dhcp := &DHCPv6{}
+	err := dhcp.DecodeFromBytes(data, p)
+	if err != nil {
+		return err
+	}
+	p.AddLayer(dhcp)
+	return p.NextDecoder(gopacket.LayerTypePayload)
+}
+
+// DHCPv6StatusCode represents a DHCP status code - RFC-3315
+type DHCPv6StatusCode uint16
+
+// Constants for the DHCPv6StatusCode.
+const (
+	DHCPv6StatusCodeSuccess DHCPv6StatusCode = iota
+	DHCPv6StatusCodeUnspecFail
+	DHCPv6StatusCodeNoAddrsAvail
+	DHCPv6StatusCodeNoBinding
+	DHCPv6StatusCodeNotOnLink
+	DHCPv6StatusCodeUseMulticast
+)
+
+// String returns a string version of a DHCPv6StatusCode.
+func (o DHCPv6StatusCode) String() string {
+	switch o {
+	case DHCPv6StatusCodeSuccess:
+		return "Success"
+	case DHCPv6StatusCodeUnspecFail:
+		return "UnspecifiedFailure"
+	case DHCPv6StatusCodeNoAddrsAvail:
+		return "NoAddressAvailable"
+	case DHCPv6StatusCodeNoBinding:
+		return "NoBinding"
+	case DHCPv6StatusCodeNotOnLink:
+		return "NotOnLink"
+	case DHCPv6StatusCodeUseMulticast:
+		return "UseMulticast"
+	default:
+		return "Unknown"
+	}
+}
+
+// DHCPv6DUIDType represents a DHCP DUID - RFC-3315
+type DHCPv6DUIDType uint16
+
+// Constants for the DHCPv6DUIDType.
+const (
+	DHCPv6DUIDTypeLLT DHCPv6DUIDType = iota + 1
+	DHCPv6DUIDTypeEN
+	DHCPv6DUIDTypeLL
+)
+
+// String returns a string version of a DHCPv6DUIDType.
+func (o DHCPv6DUIDType) String() string {
+	switch o {
+	case DHCPv6DUIDTypeLLT:
+		return "LLT"
+	case DHCPv6DUIDTypeEN:
+		return "EN"
+	case DHCPv6DUIDTypeLL:
+		return "LL"
+	default:
+		return "Unknown"
+	}
+}
+
+// DHCPv6DUID means DHCP Unique Identifier as stated in RFC 3315, section 9 (https://tools.ietf.org/html/rfc3315#page-19)
+type DHCPv6DUID struct {
+	Type DHCPv6DUIDType
+	// LLT, LL
+	HardwareType []byte
+	// EN
+	EnterpriseNumber []byte
+	// LLT
+	Time []byte
+	// LLT, LL
+	LinkLayerAddress net.HardwareAddr
+	// EN
+	Identifier []byte
+}
+
+// DecodeFromBytes decodes the given bytes into a DHCPv6DUID
+func (d *DHCPv6DUID) DecodeFromBytes(data []byte) error {
+	if len(data) < 2 {
+		return errors.New("Not enough bytes to decode: " + string(len(data)))
+	}
+
+	d.Type = DHCPv6DUIDType(binary.BigEndian.Uint16(data[:2]))
+	if d.Type == DHCPv6DUIDTypeLLT || d.Type == DHCPv6DUIDTypeLL {
+		d.HardwareType = data[2:4]
+	}
+
+	if d.Type == DHCPv6DUIDTypeLLT {
+		d.Time = data[4:8]
+		d.LinkLayerAddress = net.HardwareAddr(data[8:])
+	} else if d.Type == DHCPv6DUIDTypeEN {
+		d.EnterpriseNumber = data[2:6]
+		d.Identifier = data[6:]
+	} else { // DHCPv6DUIDTypeLL
+		d.LinkLayerAddress = net.HardwareAddr(data[4:])
+	}
+
+	return nil
+}
+
+// Encode encodes the DHCPv6DUID in a slice of bytes
+func (d *DHCPv6DUID) Encode() []byte {
+	length := d.Len()
+	data := make([]byte, length)
+	binary.BigEndian.PutUint16(data[0:2], uint16(d.Type))
+
+	if d.Type == DHCPv6DUIDTypeLLT || d.Type == DHCPv6DUIDTypeLL {
+		copy(data[2:4], d.HardwareType)
+	}
+
+	if d.Type == DHCPv6DUIDTypeLLT {
+		copy(data[4:8], d.Time)
+		copy(data[8:], d.LinkLayerAddress)
+	} else if d.Type == DHCPv6DUIDTypeEN {
+		copy(data[2:6], d.EnterpriseNumber)
+		copy(data[6:], d.Identifier)
+	} else {
+		copy(data[4:], d.LinkLayerAddress)
+	}
+
+	return data
+}
+
+// Len returns the length of the DHCPv6DUID, respecting the type
+func (d *DHCPv6DUID) Len() int {
+	length := 2 // d.Type
+	if d.Type == DHCPv6DUIDTypeLLT {
+		length += 2 /*HardwareType*/ + 4 /*d.Time*/ + len(d.LinkLayerAddress)
+	} else if d.Type == DHCPv6DUIDTypeEN {
+		length += 4 /*d.EnterpriseNumber*/ + len(d.Identifier)
+	} else { // LL
+		length += 2 /*d.HardwareType*/ + len(d.LinkLayerAddress)
+	}
+
+	return length
+}
+
+func (d *DHCPv6DUID) String() string {
+	duid := "Type: " + d.Type.String() + ", "
+	if d.Type == DHCPv6DUIDTypeLLT {
+		duid += fmt.Sprintf("HardwareType: %v, Time: %v, LinkLayerAddress: %v", d.HardwareType, d.Time, d.LinkLayerAddress)
+	} else if d.Type == DHCPv6DUIDTypeEN {
+		duid += fmt.Sprintf("EnterpriseNumber: %v, Identifier: %v", d.EnterpriseNumber, d.Identifier)
+	} else { // DHCPv6DUIDTypeLL
+		duid += fmt.Sprintf("HardwareType: %v, LinkLayerAddress: %v", d.HardwareType, d.LinkLayerAddress)
+	}
+	return duid
+}
+
+func decodeDHCPv6DUID(data []byte) (*DHCPv6DUID, error) {
+	duid := &DHCPv6DUID{}
+	err := duid.DecodeFromBytes(data)
+	if err != nil {
+		return nil, err
+	}
+	return duid, nil
+}