[VOL-1349] EPON OLT adapter (package B)

Change-Id: I634ef62c53813dcf4456f54948f13e06358e263c
diff --git a/internal/pkg/core/l2oam/msg_get_mpcp_llid.go b/internal/pkg/core/l2oam/msg_get_mpcp_llid.go
new file mode 100644
index 0000000..f1f7a10
--- /dev/null
+++ b/internal/pkg/core/l2oam/msg_get_mpcp_llid.go
@@ -0,0 +1,200 @@
+/*
+ * Copyright 2020-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package l2oam
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"fmt"
+
+	"github.com/google/gopacket"
+	"github.com/google/gopacket/layers"
+)
+
+// GetMpcpLLIdReq is a structure for "MPCP/LLID" message
+type GetMpcpLLIdReq struct {
+	layers.BaseLayer
+	Opcode uint8
+	Flags      uint16
+	OAMPDUCode uint8
+	OUId       []byte // Organizationally Unique Identifier: 2a:ea:15 (Tibit Communications)
+	TOMIOpcode uint8
+	OCBranch   uint8
+	OCType     uint16
+	OCLength   uint8
+	OCInstance uint32
+	VdBranch uint8
+	VdLeaf   uint16
+	EndBranch uint8
+}
+
+// GenerateGetMpcpLLId generates "MPCP/LLID" message
+func GenerateGetMpcpLLId(oc *TomiObjectContext) gopacket.SerializableLayer {
+	tibitData := &GetMpcpLLIdReq{
+		// IEEE 1904.2
+		Opcode: 0x03,
+		// OMI Protocol
+		Flags:      0x0050,
+		OAMPDUCode: 0xfe,
+		OUId:       []byte{0x2a, 0xea, 0x15},
+		// TiBiT OLT Management Interface
+		TOMIOpcode: 0x01,
+		// Object Context
+		OCBranch:   oc.Branch,
+		OCType:     oc.Type,
+		OCLength:   oc.Length,
+		OCInstance: oc.Instance,
+		// Vd
+		VdBranch: 0xcc,
+		VdLeaf:   0x0007,
+		// End
+		EndBranch: 0,
+	}
+	return tibitData
+}
+
+// String returns the string expression of GetMpcpLLIdReq
+func (d *GetMpcpLLIdReq) String() string {
+	message := fmt.Sprintf("Opcode:%02x, Flags:%04x, OAMPDUCode:%02x, OUId:%v", d.Opcode, d.Flags, d.OAMPDUCode, hex.EncodeToString(d.OUId))
+	message = fmt.Sprintf("%s, TOMIOpcode:%02x", message, d.TOMIOpcode)
+	message = fmt.Sprintf("%s, OCBranch:%02x, OCType:%04x, OCLength:%02x, OCInstance:%08x", message, d.OCBranch, d.OCType, d.OCLength, d.OCInstance)
+	message = fmt.Sprintf("%s, VdBranch:%02x, VdLeaf:%04x, EndBranch:%02x", message, d.VdBranch, d.VdLeaf, d.EndBranch)
+	return message
+}
+
+// Len returns the length of GetMpcpLLIdReq
+func (d *GetMpcpLLIdReq) Len() int {
+	return 21
+}
+
+// LayerType returns the ethernet type of GetMpcpLLIdReq
+func (d *GetMpcpLLIdReq) LayerType() gopacket.LayerType { return layers.LayerTypeEthernet }
+
+// SerializeTo serializes a data structure to byte arrays
+func (d *GetMpcpLLIdReq) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	plen := int(d.Len())
+	data, err := b.PrependBytes(plen)
+	if err != nil {
+		return err
+	}
+
+	i := 0
+	data[i] = byte(d.Opcode)
+	i++
+	binary.BigEndian.PutUint16(data[i:i+2], d.Flags)
+	i += 2
+	data[i] = byte(d.OAMPDUCode)
+	i++
+	copy(data[i:i+len(d.OUId)], d.OUId)
+	i += len(d.OUId)
+	data[i] = byte(d.TOMIOpcode)
+	i++
+	data[i] = byte(d.OCBranch)
+	i++
+	binary.BigEndian.PutUint16(data[i:i+2], d.OCType)
+	i += 2
+	data[i] = byte(d.OCLength)
+	i++
+	binary.BigEndian.PutUint32(data[i:i+4], d.OCInstance)
+	i += 4
+	data[i] = byte(d.VdBranch)
+	i++
+	binary.BigEndian.PutUint16(data[i:i+2], d.VdLeaf)
+	i += 2
+	data[i] = byte(d.EndBranch)
+
+	return nil
+}
+
+// GetMpcpLLIdRes is a structure for a response of "MPCP/LLID" message
+type GetMpcpLLIdRes struct {
+	layers.BaseLayer
+	Opcode uint8
+	Flags      uint16
+	OAMPDUCode uint8
+	OUId       []byte // Organizationally Unique Identifier: 2a:ea:15 (Tibit Communications)
+	TOMIOpcode uint8
+	OCBranch   uint8
+	OCType     uint16
+	OCLength   uint8
+	OCInstance uint32
+	VcBranch uint8
+	VcLeaf   uint16
+	VcLength uint8
+	EcLength uint8
+	EcValue  []byte
+	EndBranch uint8
+}
+
+// String returns the string expression of GetMpcpLLIdRes
+func (d *GetMpcpLLIdRes) String() string {
+	message := fmt.Sprintf("Opcode:%02x, Flags:%04x, OAMPDUCode:%02x, OUId:%v", d.Opcode, d.Flags, d.OAMPDUCode, hex.EncodeToString(d.OUId))
+	message = fmt.Sprintf("%s, TOMIOpcode:%02x", message, d.TOMIOpcode)
+	message = fmt.Sprintf("%s, OCBranch:%02x, OCType:%04x, OCLength:%02x, OCInstance:%08x", message, d.OCBranch, d.OCType, d.OCLength, d.OCInstance)
+	message = fmt.Sprintf("%s, VcBranch:%02x, VcLeaf:%04x, VcLength:%02x", message, d.VcBranch, d.VcLeaf, d.VcLength)
+	message = fmt.Sprintf("%s, EcLength:%02x, EcValue:%v, EndBranch:%02x", message, d.EcLength, hex.EncodeToString(d.EcValue), d.EndBranch)
+	return message
+}
+
+// Len returns the length of GetMpcpLLIdRes
+func (d *GetMpcpLLIdRes) Len() int {
+	return 20 + int(d.VcLength) + 1
+}
+
+// LayerType returns the ethernet type of GetMpcpLLIdRes
+func (d *GetMpcpLLIdRes) LayerType() gopacket.LayerType { return layers.LayerTypeEthernet }
+
+// Decode decodes byte arrays to a data structure
+func (d *GetMpcpLLIdRes) Decode(data []byte) error {
+	i := 0
+	d.Opcode = data[i]
+	i++
+	d.Flags = binary.BigEndian.Uint16(data[i : i+2])
+	i += 2
+	d.OAMPDUCode = data[i]
+	i++
+	d.OUId = data[i : i+3]
+	i += len(d.OUId)
+	d.TOMIOpcode = data[i]
+	i++
+	d.OCBranch = data[i]
+	i++
+	d.OCType = binary.BigEndian.Uint16(data[i : i+2])
+	i += 2
+	d.OCLength = data[i]
+	i++
+	d.OCInstance = binary.BigEndian.Uint32(data[i : i+4])
+	i += 4
+	d.VcBranch = data[i]
+	i++
+	d.VcLeaf = binary.BigEndian.Uint16(data[i : i+2])
+	i += 2
+	d.VcLength = data[i]
+	i++
+	d.EcLength = data[i]
+	i++
+	d.EcValue = data[i : i+int(d.EcLength)]
+	i += int(d.EcLength)
+	d.EndBranch = data[i]
+
+	return nil
+}
+
+// GetLLID returns a LLID
+func (d *GetMpcpLLIdRes) GetLLID() uint16 {
+	return binary.BigEndian.Uint16(d.EcValue)
+}