First Commit of Voltha-Go-Controller from Radisys

Change-Id: I8e2e908e7ab09a4fe3d86849da18b6d69dcf4ab0
diff --git a/vendor/github.com/google/gopacket/layers/loopback.go b/vendor/github.com/google/gopacket/layers/loopback.go
new file mode 100644
index 0000000..839f760
--- /dev/null
+++ b/vendor/github.com/google/gopacket/layers/loopback.go
@@ -0,0 +1,80 @@
+// Copyright 2012 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"
+
+	"github.com/google/gopacket"
+)
+
+// Loopback contains the header for loopback encapsulation.  This header is
+// used by both BSD and OpenBSD style loopback decoding (pcap's DLT_NULL
+// and DLT_LOOP, respectively).
+type Loopback struct {
+	BaseLayer
+	Family ProtocolFamily
+}
+
+// LayerType returns LayerTypeLoopback.
+func (l *Loopback) LayerType() gopacket.LayerType { return LayerTypeLoopback }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (l *Loopback) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 4 {
+		return errors.New("Loopback packet too small")
+	}
+
+	// The protocol could be either big-endian or little-endian, we're
+	// not sure.  But we're PRETTY sure that the value is less than
+	// 256, so we can check the first two bytes.
+	var prot uint32
+	if data[0] == 0 && data[1] == 0 {
+		prot = binary.BigEndian.Uint32(data[:4])
+	} else {
+		prot = binary.LittleEndian.Uint32(data[:4])
+	}
+	if prot > 0xFF {
+		return fmt.Errorf("Invalid loopback protocol %q", data[:4])
+	}
+
+	l.Family = ProtocolFamily(prot)
+	l.BaseLayer = BaseLayer{data[:4], data[4:]}
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (l *Loopback) CanDecode() gopacket.LayerClass {
+	return LayerTypeLoopback
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (l *Loopback) NextLayerType() gopacket.LayerType {
+	return l.Family.LayerType()
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+func (l *Loopback) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	bytes, err := b.PrependBytes(4)
+	if err != nil {
+		return err
+	}
+	binary.LittleEndian.PutUint32(bytes, uint32(l.Family))
+	return nil
+}
+
+func decodeLoopback(data []byte, p gopacket.PacketBuilder) error {
+	l := Loopback{}
+	if err := l.DecodeFromBytes(data, gopacket.NilDecodeFeedback); err != nil {
+		return err
+	}
+	p.AddLayer(&l)
+	return p.NextDecoder(l.Family)
+}