diff --git a/vendor/github.com/google/gopacket/layers/stp.go b/vendor/github.com/google/gopacket/layers/stp.go
new file mode 100644
index 0000000..31c2a6e
--- /dev/null
+++ b/vendor/github.com/google/gopacket/layers/stp.go
@@ -0,0 +1,150 @@
+// Copyright 2017 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"
+)
+
+type STPSwitchID struct {
+	Priority uint16 // Bridge priority
+	SysID    uint16 // VLAN ID
+	HwAddr   net.HardwareAddr
+}
+
+// STP decode spanning tree protocol packets to transport BPDU (bridge protocol data unit) message.
+type STP struct {
+	BaseLayer
+	ProtocolID        uint16
+	Version           uint8
+	Type              uint8
+	TC, TCA           bool // TC: Topologie change ; TCA: Topologie change ack
+	RouteID, BridgeID STPSwitchID
+	Cost              uint32
+	PortID            uint16
+	MessageAge        uint16
+	MaxAge            uint16
+	HelloTime         uint16
+	FDelay            uint16
+}
+
+// LayerType returns gopacket.LayerTypeSTP.
+func (s *STP) LayerType() gopacket.LayerType { return LayerTypeSTP }
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (s *STP) CanDecode() gopacket.LayerClass {
+	return LayerTypeSTP
+}
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (stp *STP) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	stpLength := 35
+	if len(data) < stpLength {
+		df.SetTruncated()
+		return fmt.Errorf("STP length %d too short", len(data))
+	}
+
+	stp.ProtocolID = binary.BigEndian.Uint16(data[:2])
+	stp.Version = uint8(data[2])
+	stp.Type = uint8(data[3])
+	stp.TC = data[4]&0x01 != 0
+	stp.TCA = data[4]&0x80 != 0
+	stp.RouteID.Priority = binary.BigEndian.Uint16(data[5:7]) & 0xf000
+	stp.RouteID.SysID = binary.BigEndian.Uint16(data[5:7]) & 0x0fff
+	stp.RouteID.HwAddr = net.HardwareAddr(data[7:13])
+	stp.Cost = binary.BigEndian.Uint32(data[13:17])
+	stp.BridgeID.Priority = binary.BigEndian.Uint16(data[17:19]) & 0xf000
+	stp.BridgeID.SysID = binary.BigEndian.Uint16(data[17:19]) & 0x0fff
+	stp.BridgeID.HwAddr = net.HardwareAddr(data[19:25])
+	stp.PortID = binary.BigEndian.Uint16(data[25:27])
+	stp.MessageAge = binary.BigEndian.Uint16(data[27:29])
+	stp.MaxAge = binary.BigEndian.Uint16(data[29:31])
+	stp.HelloTime = binary.BigEndian.Uint16(data[31:33])
+	stp.FDelay = binary.BigEndian.Uint16(data[33:35])
+	stp.Contents = data[:stpLength]
+	stp.Payload = data[stpLength:]
+
+	return nil
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (stp *STP) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+// Check if the priority value is correct.
+func checkPriority(prio uint16) (uint16, error) {
+	if prio == 0 {
+		return prio, errors.New("Invalid Priority value must be in the rage <4096-61440> with an increment of 4096")
+	}
+	if prio%4096 == 0 {
+		return prio, nil
+	} else {
+		return prio, errors.New("Invalid Priority value must be in the rage <4096-61440> with an increment of 4096")
+	}
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (s *STP) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	var flags uint8 = 0x00
+	bytes, err := b.PrependBytes(35)
+	if err != nil {
+		return err
+	}
+	binary.BigEndian.PutUint16(bytes, s.ProtocolID)
+	bytes[2] = s.Version
+	bytes[3] = s.Type
+	if s.TC {
+		flags |= 0x01
+	}
+	if s.TCA {
+		flags |= 0x80
+	}
+	bytes[4] = flags
+
+	prioRoot, err := checkPriority(s.RouteID.Priority)
+	if err != nil {
+		panic(err)
+	}
+	if s.RouteID.SysID >= 4096 {
+		panic("Invalid VlanID value ..!")
+	}
+	binary.BigEndian.PutUint16(bytes[5:7], prioRoot|s.RouteID.SysID)
+	copy(bytes[7:13], s.RouteID.HwAddr)
+
+	binary.BigEndian.PutUint32(bytes[13:17], s.Cost)
+
+	prioBridge, err := checkPriority(s.BridgeID.Priority)
+	if err != nil {
+		panic(err)
+	}
+	if s.BridgeID.SysID >= 4096 {
+		panic("Invalid VlanID value ..!")
+	}
+	binary.BigEndian.PutUint16(bytes[17:19], prioBridge|s.BridgeID.SysID)
+	copy(bytes[19:25], s.BridgeID.HwAddr)
+
+	binary.BigEndian.PutUint16(bytes[25:27], s.PortID)
+	binary.BigEndian.PutUint16(bytes[27:29], s.MessageAge)
+	binary.BigEndian.PutUint16(bytes[29:31], s.MaxAge)
+	binary.BigEndian.PutUint16(bytes[31:33], s.HelloTime)
+	binary.BigEndian.PutUint16(bytes[33:35], s.FDelay)
+
+	return nil
+}
+
+func decodeSTP(data []byte, p gopacket.PacketBuilder) error {
+	stp := &STP{}
+	return decodingLayerDecoder(stp, data, p)
+}