TUN-6666: Define packet package

This package defines IP and ICMP packet, decoders, encoder and flow

vendor/github.com/google/gopacket/layers/base.go

@@ -0,0 +1,52 @@
+// 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 (
+	"github.com/google/gopacket"
+)
+
+// BaseLayer is a convenience struct which implements the LayerData and
+// LayerPayload functions of the Layer interface.
+type BaseLayer struct {
+	// Contents is the set of bytes that make up this layer.  IE: for an
+	// Ethernet packet, this would be the set of bytes making up the
+	// Ethernet frame.
+	Contents []byte
+	// Payload is the set of bytes contained by (but not part of) this
+	// Layer.  Again, to take Ethernet as an example, this would be the
+	// set of bytes encapsulated by the Ethernet protocol.
+	Payload []byte
+}
+
+// LayerContents returns the bytes of the packet layer.
+func (b *BaseLayer) LayerContents() []byte { return b.Contents }
+
+// LayerPayload returns the bytes contained within the packet layer.
+func (b *BaseLayer) LayerPayload() []byte { return b.Payload }
+
+type layerDecodingLayer interface {
+	gopacket.Layer
+	DecodeFromBytes([]byte, gopacket.DecodeFeedback) error
+	NextLayerType() gopacket.LayerType
+}
+
+func decodingLayerDecoder(d layerDecodingLayer, data []byte, p gopacket.PacketBuilder) error {
+	err := d.DecodeFromBytes(data, p)
+	if err != nil {
+		return err
+	}
+	p.AddLayer(d)
+	next := d.NextLayerType()
+	if next == gopacket.LayerTypeZero {
+		return nil
+	}
+	return p.NextDecoder(next)
+}
+
+// hacky way to zero out memory... there must be a better way?
+var lotsOfZeros [1024]byte