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

Change-Id: I609ba349c429bc7e87c74b66bb1121841f9caef6
diff --git a/internal/pkg/onuadaptercore/olt_onu_msg.go b/internal/pkg/onuadaptercore/olt_onu_msg.go
new file mode 100644
index 0000000..f18910a
--- /dev/null
+++ b/internal/pkg/onuadaptercore/olt_onu_msg.go
@@ -0,0 +1,67 @@
+/*
+ * 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 adaptercoreonu
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/opencord/voltha-lib-go/v3/pkg/log"
+	ic "github.com/opencord/voltha-protos/v3/go/inter_container"
+	oop "github.com/opencord/voltha-protos/v3/go/openolt"
+)
+
+//AdditionalMessage ...
+type AdditionalMessage struct {
+}
+
+/*
+func (dh *deviceHandler) receivedMsgFromOlt(msg *ic.InterAdapterMessage) error {
+	msgBody := msg.GetBody()
+	ind := &oop.OnuIndication{}
+
+	err := ptypes.UnmarshalAny(msgBody, ind)
+	if err != nil {
+		logger.Debugw("cannot-unmarshal-onu-indication-body", log.Fields{"error": err})
+	} else {
+		var info AdditionalMessage
+		err = json.Unmarshal(ind.SerialNumber.VendorSpecific, &info)
+		if err != nil {
+			logger.Debugw("cannot-unmarshal-additional-message", log.Fields{"error": err})
+		}
+	}
+
+	return err
+}
+*/
+func (dh *deviceHandler) sendMsgToOlt(ctx context.Context, msg string, option interface{}) error {
+	bytes, _ := json.Marshal(option)
+	info := oop.OnuIndication{
+		SerialNumber: &oop.SerialNumber{
+			VendorSpecific: bytes,
+		},
+	}
+
+	err := dh.AdapterProxy.SendInterAdapterMessage(ctx, &info,
+		ic.InterAdapterMessageType_ONU_IND_REQUEST,
+		dh.DeviceType, dh.ProxyAddressType,
+		dh.deviceID, dh.parentID, msg)
+
+	if err != nil {
+		logger.Debugw("err-sending-message", log.Fields{"device": dh})
+	}
+	return err
+}