/src/PcapPlusPlus/Packet++/header/GtpLayer.h

Source (jump to first uncovered line)
#ifndef PACKETPP_GTP_LAYER
#define PACKETPP_GTP_LAYER

#include "Layer.h"

/// @file


/**
 * \namespace pcpp
 * \brief The main namespace for the PcapPlusPlus lib
 */
namespace pcpp
{

#pragma pack(push, 1)
  /**
   * @struct gtpv1_header
   * GTP v1 common message header
   */
  struct gtpv1_header
  {
#if (BYTE_ORDER == LITTLE_ENDIAN)
    /** A 1-bit value that states whether there is a N-PDU number optional field */
    uint8_t npduNumberFlag:1,
    /** A 1-bit value that states whether there is a Sequence Number optional field */
    sequenceNumberFlag:1,
    /** A 1-bit value that states whether there is an extension header optional field */
    extensionHeaderFlag:1,
    /** Reserved bit */
    reserved:1,
    /** A 1-bit value that differentiates GTP (value 1) from GTP' (value 0) */
    protocolType:1,
    /** GTP version */
    version:3;
#else
    /** GTP version */
    uint8_t version:3,
    /** A 1-bit value that differentiates GTP (value 1) from GTP' (value 0) */
    protocolType:1,
    /** Reserved bit */
    reserved:1,
    /** A 1-bit value that states whether there is an extension header optional field */
    extensionHeaderFlag:1,
    /** A 1-bit value that states whether there is a Sequence Number optional field */
    sequenceNumberFlag:1,
    /** A 1-bit value that states whether there is a N-PDU number optional field */
    npduNumberFlag:1;
#endif
    /** An 8-bit field that indicates the type of GTP message */
    uint8_t messageType;

    /** A 16-bit field that indicates the length of the payload in bytes (rest of the packet following the mandatory 8-byte GTP header). Includes the optional fields */
    uint16_t messageLength;

    /** Tunnel endpoint identifier - A 32-bit(4-octet) field used to multiplex different connections in the same GTP tunnel */
    uint32_t teid;
  };

#pragma pack(pop)

  /**
   * An enum representing the possible GTP v1 message types.
   * All of the message types except for #GtpV1_GPDU are considered GTP-C messages. #GtpV1_GPDU is considered a GTP-U message
   */
  enum GtpV1MessageType
  {
    /** GTPv1 Message Type Unknown */
    GtpV1_MessageTypeUnknown = 0,
    /** Echo Request */
    GtpV1_EchoRequest = 1,
    /** Echo Response */
    GtpV1_EchoResponse = 2,
    /** Version Not Supported */
    GtpV1_VersionNotSupported = 3,
    /** Node Alive Request */
    GtpV1_NodeAliveRequest = 4,
    /** Node Alive Response */
    GtpV1_NodeAliveResponse = 5,
    /** Redirection Request */
    GtpV1_RedirectionRequest = 6,
    /** Create PDP Context Request */
    GtpV1_CreatePDPContextRequest = 7,
    /** Create PDP Context Response */
    GtpV1_CreatePDPContextResponse = 16,
    /** Update PDP Context Request */
    GtpV1_UpdatePDPContextRequest = 17,
    /** Update PDP Context Response */
    GtpV1_UpdatePDPContextResponse = 18,
    /** Delete PDP Context Request */
    GtpV1_DeletePDPContextRequest = 19,
    /** Delete PDP Context Response */
    GtpV1_DeletePDPContextResponse = 20,
    /** Initiate PDP Context Activation Request */
    GtpV1_InitiatePDPContextActivationRequest = 22,
    /** Initiate PDP Context Activation Response */
    GtpV1_InitiatePDPContextActivationResponse = 23,
    /** Error Indication */
    GtpV1_ErrorIndication = 26,
    /** PDU Notification Request */
    GtpV1_PDUNotificationRequest = 27,
    /** PDU Notification Response */
    GtpV1_PDUNotificationResponse = 28,
    /** PDU Notification Reject Request */
    GtpV1_PDUNotificationRejectRequest = 29,
    /** PDU Notification Reject Response */
    GtpV1_PDUNotificationRejectResponse = 30,
    /** Supported Extensions Header Notification */
    GtpV1_SupportedExtensionsHeaderNotification = 31,
    /** Send Routing for GPRS Request */
    GtpV1_SendRoutingforGPRSRequest = 32,
    /** Send Routing for GPRS Response */
    GtpV1_SendRoutingforGPRSResponse = 33,
    /** Failure Report Request */
    GtpV1_FailureReportRequest = 34,
    /** Failure Report Response */
    GtpV1_FailureReportResponse = 35,
    /** Note MS Present Request */
    GtpV1_NoteMSPresentRequest = 36,
    /** Note MS Present Response */
    GtpV1_NoteMSPresentResponse = 37,
    /** Identification Request */
    GtpV1_IdentificationRequest = 38,
    /** Identification Response */
    GtpV1_IdentificationResponse = 39,
    /** SGSN Context Request */
    GtpV1_SGSNContextRequest = 50,
    /** SGSN Context Response */
    GtpV1_SGSNContextResponse = 51,
    /** SGSN Context Acknowledge */
    GtpV1_SGSNContextAcknowledge = 52,
    /** Forward Relocation Request */
    GtpV1_ForwardRelocationRequest = 53,
    /** Forward Relocation Response */
    GtpV1_ForwardRelocationResponse = 54,
    /** Forward Relocation Complete */
    GtpV1_ForwardRelocationComplete = 55,
    /** Relocation Cancel Request */
    GtpV1_RelocationCancelRequest = 56,
    /** Relocation Cancel Response */
    GtpV1_RelocationCancelResponse = 57,
    /** Forward SRNS Context */
    GtpV1_ForwardSRNSContext = 58,
    /** Forward Relocation Complete Acknowledge */
    GtpV1_ForwardRelocationCompleteAcknowledge = 59,
    /** Forward SRNS Context Acknowledge */
    GtpV1_ForwardSRNSContextAcknowledge = 60,
    /** UE Registration Request */
    GtpV1_UERegistrationRequest = 61,
    /** UE Registration Response */
    GtpV1_UERegistrationResponse = 62,
    /** RAN Information Relay */
    GtpV1_RANInformationRelay = 70,
    /** MBMS Notification Request */
    GtpV1_MBMSNotificationRequest = 96,
    /** MBMS Notification Response */
    GtpV1_MBMSNotificationResponse = 97,
    /** MBMS Notification Reject Request */
    GtpV1_MBMSNotificationRejectRequest = 98,
    /** MBMS Notification Reject Response */
    GtpV1_MBMSNotificationRejectResponse = 99,
    /** Create MBMS Notification Request */
    GtpV1_CreateMBMSNotificationRequest = 100,
    /** Create MBMS Notification Response */
    GtpV1_CreateMBMSNotificationResponse = 101,
    /** Update MBMS Notification Request */
    GtpV1_UpdateMBMSNotificationRequest = 102,
    /** Update MBMS Notification Response */
    GtpV1_UpdateMBMSNotificationResponse = 103,
    /** Delete MBMS Notification Request */
    GtpV1_DeleteMBMSNotificationRequest = 104,
    /** Delete MBMS Notification Response */
    GtpV1_DeleteMBMSNotificationResponse = 105,
    /** MBMS Registration Request */
    GtpV1_MBMSRegistrationRequest = 112,
    /** MBMS Registration Response */
    GtpV1_MBMSRegistrationResponse = 113,
    /** MBMS De-Registration Request */
    GtpV1_MBMSDeRegistrationRequest = 114,
    /** MBMS De-Registration Response */
    GtpV1_MBMSDeRegistrationResponse = 115,
    /** MBMS Session Start Request */
    GtpV1_MBMSSessionStartRequest = 116,
    /** MBMS Session Start Response */
    GtpV1_MBMSSessionStartResponse = 117,
    /** MBMS Session Stop Request */
    GtpV1_MBMSSessionStopRequest = 118,
    /** MBMS Session Stop Response */
    GtpV1_MBMSSessionStopResponse = 119,
    /** MBMS Session Update Request */
    GtpV1_MBMSSessionUpdateRequest = 120,
    /** MBMS Session Update Response */
    GtpV1_MBMSSessionUpdateResponse = 121,
    /** MS Info Change Request */
    GtpV1_MSInfoChangeRequest = 128,
    /** MS Info Change Response */
    GtpV1_MSInfoChangeResponse = 129,
    /** Data Record Transfer Request */
    GtpV1_DataRecordTransferRequest = 240,
    /** Data Record Transfer Response */
    GtpV1_DataRecordTransferResponse = 241,
    /** End Marker */
    GtpV1_EndMarker = 254,
    /** G-PDU */
    GtpV1_GPDU = 255
  };


  /**
   * @class GtpV1Layer
   * A class representing the [GTP v1](https://en.wikipedia.org/wiki/GPRS_Tunnelling_Protocol) protocol.
   */
  class GtpV1Layer : public Layer
  {
  private:
    struct gtpv1_header_extra
    {
      uint16_t sequenceNumber;
      uint8_t npduNumber;
      uint8_t nextExtensionHeader;
    };

    gtpv1_header_extra* getHeaderExtra() const;

    void init(GtpV1MessageType messageType, uint32_t teid, bool setSeqNum, uint16_t seqNum, bool setNpduNum, uint8_t npduNum);

  public:

    /**
     * @class GtpExtension
     * A class that represents [GTP header extensions](https://en.wikipedia.org/wiki/GPRS_Tunnelling_Protocol)
     */
    class GtpExtension
    {
      friend class GtpV1Layer;

    private:
      uint8_t* m_Data;
      size_t m_DataLen;
      uint8_t m_ExtType;

      GtpExtension(uint8_t* data, size_t dataLen, uint8_t type);

      void setNextHeaderType(uint8_t nextHeaderType);

      static GtpExtension createGtpExtension(uint8_t* data, size_t dataLen, uint8_t extType, uint16_t content);

    public:

      /**
       * An empty c'tor that creates an empty object, meaning one that isNull() returns "true")
       */
      GtpExtension();

      /**
       * A copy c'tor for this class
       * @param[in] other The GTP extension to copy from
       */
      GtpExtension(const GtpExtension& other);

      /**
       * An assignment operator for this class
       * @param[in] other The extension to assign from
       * @return A reference to the assignee
       */
      GtpExtension& operator=(const GtpExtension& other);

      /**
       * @return Instances of this class may be initialized as empty, meaning they don't contain any data. In
       * these cases this method returns true
       */
      bool isNull() const;

      /**
       * @return The extension type. If the object is empty a value of zero is returned
       */
      uint8_t getExtensionType() const;

      /**
       * @return The total length of the extension including the length and next extension type fields.
       * If the object is empty a value of zero is returned
       */
      size_t getTotalLength() const;

      /**
       * @return The length of the extension's content, excluding the extension length and next extension type fields.
       * If the object is empty a value of zero is returned
       */
      size_t getContentLength() const;

      /**
       * @return A byte array that includes the extension's content. The length of this array can be determined by
       * getContentLength(). If the object is empty a null value is returned
       */
      uint8_t* getContent() const;

      /**
       * @return The extension type of the next header. If there are no more header extensions or if this object is empty
       * a value of zero is returned
       */
      uint8_t getNextExtensionHeaderType() const;

      /**
       * @return An instance of this class representing the next extension header, if exists in the message. If there are
       * no more header extensions or if this object is empty an empty instance of GtpExtension is returned, meaning
       * one that GtpExtension#isNull() returns "true"
       */
      GtpExtension getNextExtension() const;
    }; // GtpExtension

    virtual ~GtpV1Layer() {}

     /** A constructor that creates the layer from an existing packet raw data
     * @param[in] data A pointer to the raw data
     * @param[in] dataLen Size of the data in bytes
     * @param[in] prevLayer A pointer to the previous layer
     * @param[in] packet A pointer to the Packet instance where layer will be stored in
     */
    GtpV1Layer(uint8_t* data, size_t dataLen, Layer* prevLayer, Packet* packet) : Layer(data, dataLen, prevLayer, packet) { m_Protocol = GTPv1; }

    /**
     * A constructor that creates a new GTPv1 layer and sets the message type and the TEID value
     * @param[in] messageType The GTPv1 message type to be set in the newly created layer
     * @param[in] teid The TEID value to be set in the newly created layer
     */
    GtpV1Layer(GtpV1MessageType messageType, uint32_t teid);

    /**
     * A constructor that creates a new GTPv1 layer and sets various parameters
     * @param[in] messageType The GTPv1 message type to be set in the newly created layer
     * @param[in] teid The TEID value to be set in the newly created layer
     * @param[in] setSeqNum A flag indicating whether to set a sequence number. If set to "false" then the parameter "seqNum" will be ignored
     * @param[in] seqNum The sequence number to be set in the newly created later. If "setSeqNum" is set to false this parameter will be ignored
     * @param[in] setNpduNum A flag indicating whether to set the N-PDU number. If set to "false" then the parameter "npduNum" will be ignored
     * @param[in] npduNum The N-PDU number to be set in the newly created later. If "setNpduNum" is set to false this parameter will be ignored
     */
    GtpV1Layer(GtpV1MessageType messageType, uint32_t teid, bool setSeqNum, uint16_t seqNum, bool setNpduNum, uint8_t npduNum);

    /**
     * A static method that takes a byte array and detects whether it is a GTP v1 message
     * @param[in] data A byte array
     * @param[in] dataSize The byte array size (in bytes)
     * @return True if the data is identified as GTP v1 message (GTP-C or GTP-U)
     */
    static bool isGTPv1(const uint8_t* data, size_t dataSize);

    /**
     * @return The GTP v1 common header structure. Notice this points directly to the data, so every change will change the actual packet data
     */
    gtpv1_header* getHeader() const { return (gtpv1_header*)m_Data; }

    /**
     * Get the sequence number if exists on the message (sequence number is an optional field in GTP messages)
     * @param[out] seqNumber Set with the sequence number value if exists in the layer. Otherwise remains unchanged
     * @return True if the sequence number field exists in layer, in which case seqNumber is set with the value.
     * Or false otherwise
     */
    bool getSequenceNumber(uint16_t& seqNumber) const;

    /**
     * Set a sequence number
     * @param[in] seqNumber The sequence number to set
     * @return True if the value was set successfully, false otherwise. In case of failure a corresponding error message will be written to log
     */
    bool setSequenceNumber(const uint16_t seqNumber);

    /**
     * Get the N-PDU number if exists on the message (N-PDU number is an optional field in GTP messages)
     * @param[out] npduNum Set with the N-PDU number value if exists in the layer. Otherwise remains unchanged
     * @return True if the N-PDU number field exists in layer, in which case npduNum is set with the value.
     * Or false otherwise
     */
    bool getNpduNumber(uint8_t& npduNum) const;

    /**
     * Set an N-PDU number
     * @param[in] npduNum The N-PDU number to set
     * @return True if the value was set successfully, false otherwise. In case of failure a corresponding error message will be written to log
     */
    bool setNpduNumber(const uint8_t npduNum);

    /**
     * Get the type of the next header extension if exists on the message (extensions are optional in GTP messages)
     * @param[out] nextExtType Set with the next header extension type if exists in layer. Otherwise remains unchanged
     * @return True if the message contains header extensions, in which case nextExtType is set to the next
     * header extension type. If there are no header extensions false is returned and nextExtType remains unchanged
     */
    bool getNextExtensionHeaderType(uint8_t& nextExtType) const;

    /**
     * @return An object that represents the next extension header, if exists in the message. If there are no extensions
     * an empty object is returned, meaning an object which GtpExtension#isNull() returns "true"
     */
    GtpExtension getNextExtension() const;

    /**
     * Add a GTPv1 header extension. It is assumed that the extension is 4 bytes in length and its content is 2 bytes in length.
     * If you need a different content size please reach out to me. This method takes care of extending the layer to make room for
     * the new extension and also sets the relevant flags and fields
     * @param[in] extensionType The type of the new extension
     * @param[in] extensionContent A 2-byte long content
     * @return An object representing the newly added extension. If there was an error adding the extension a null object will be
     * returned (meaning GtpExtension#isNull() will return "true") and a corresponding error message will be written to log
     */
    GtpExtension addExtension(uint8_t extensionType, uint16_t extensionContent);

    /**
     * @return The message type of this GTP packet
     */
    GtpV1MessageType getMessageType() const;

    /**
     * @return A string representation of the packet's message type
     */
    std::string getMessageTypeAsString() const;

    /**
     * @return True if this is a GTP-U message, false otherwise
     */
    bool isGTPUMessage() const;

    /**
     * @return True if this is a GTP-C message, false otherwise
     */
    bool isGTPCMessage() const;

    /**
     * A static method that checks whether the port is considered as GTPv1
     * @param[in] port The port number to be checked
     * @return True if the port matches those associated with the BGP protocol
     */
    static bool isGTPv1Port(uint16_t port) { return port == 2152 /* GTP-U */ || port == 2123 /* GTP-C */; }


    // implement abstract methods

    /**
     * Identifies the following next layers for GTP-U packets: IPv4Layer, IPv6Layer. Otherwise sets PayloadLayer
     */
    void parseNextLayer();

    /**
     * @return The size of the GTP header. For GTP-C packets the size is determined by the value of
     * gtpv1_header#messageLength and for GTP-U the size only includes the GTP header itself (meaning
     * the size of gtpv1_header plus the size of the optional fields such as sequence number, N-PDU
     * or extensions if exist)
     */
    size_t getHeaderLen() const;

    /**
     * Calculate the following fields:
     * - gtpv1_header#messageLength
     */
    void computeCalculateFields();

    std::string toString() const;

    OsiModelLayer getOsiModelLayer() const { return OsiModelTransportLayer; }
  };
}

#endif //PACKETPP_GTP_LAYER

Coverage Report

Created: 2023-01-17 06:15

Line	Count	Source (jump to first uncovered line)
1		#ifndef PACKETPP_GTP_LAYER
2		#define PACKETPP_GTP_LAYER
3
4		#include "Layer.h"
5
6		/// @file
7
8
9		/**
10		* \namespace pcpp
11		* \brief The main namespace for the PcapPlusPlus lib
12		*/
13		namespace pcpp
14		{
15
16		#pragma pack(push, 1)
17		/**
18		* @struct gtpv1_header
19		* GTP v1 common message header
20		*/
21		struct gtpv1_header
22		{
23		#if (BYTE_ORDER == LITTLE_ENDIAN)
24		/** A 1-bit value that states whether there is a N-PDU number optional field */
25		uint8_t npduNumberFlag:1,
26		/** A 1-bit value that states whether there is a Sequence Number optional field */
27		sequenceNumberFlag:1,
28		/** A 1-bit value that states whether there is an extension header optional field */
29		extensionHeaderFlag:1,
30		/** Reserved bit */
31		reserved:1,
32		/** A 1-bit value that differentiates GTP (value 1) from GTP' (value 0) */
33		protocolType:1,
34		/** GTP version */
35		version:3;
36		#else
37		/** GTP version */
38		uint8_t version:3,
39		/** A 1-bit value that differentiates GTP (value 1) from GTP' (value 0) */
40		protocolType:1,
41		/** Reserved bit */
42		reserved:1,
43		/** A 1-bit value that states whether there is an extension header optional field */
44		extensionHeaderFlag:1,
45		/** A 1-bit value that states whether there is a Sequence Number optional field */
46		sequenceNumberFlag:1,
47		/** A 1-bit value that states whether there is a N-PDU number optional field */
48		npduNumberFlag:1;
49		#endif
50		/** An 8-bit field that indicates the type of GTP message */
51		uint8_t messageType;
52
53		/** A 16-bit field that indicates the length of the payload in bytes (rest of the packet following the mandatory 8-byte GTP header). Includes the optional fields */
54		uint16_t messageLength;
55
56		/** Tunnel endpoint identifier - A 32-bit(4-octet) field used to multiplex different connections in the same GTP tunnel */
57		uint32_t teid;
58		};
59
60		#pragma pack(pop)
61
62		/**
63		* An enum representing the possible GTP v1 message types.
64		* All of the message types except for #GtpV1_GPDU are considered GTP-C messages. #GtpV1_GPDU is considered a GTP-U message
65		*/
66		enum GtpV1MessageType
67		{
68		/** GTPv1 Message Type Unknown */
69		GtpV1_MessageTypeUnknown = 0,
70		/** Echo Request */
71		GtpV1_EchoRequest = 1,
72		/** Echo Response */
73		GtpV1_EchoResponse = 2,
74		/** Version Not Supported */
75		GtpV1_VersionNotSupported = 3,
76		/** Node Alive Request */
77		GtpV1_NodeAliveRequest = 4,
78		/** Node Alive Response */
79		GtpV1_NodeAliveResponse = 5,
80		/** Redirection Request */
81		GtpV1_RedirectionRequest = 6,
82		/** Create PDP Context Request */
83		GtpV1_CreatePDPContextRequest = 7,
84		/** Create PDP Context Response */
85		GtpV1_CreatePDPContextResponse = 16,
86		/** Update PDP Context Request */
87		GtpV1_UpdatePDPContextRequest = 17,
88		/** Update PDP Context Response */
89		GtpV1_UpdatePDPContextResponse = 18,
90		/** Delete PDP Context Request */
91		GtpV1_DeletePDPContextRequest = 19,
92		/** Delete PDP Context Response */
93		GtpV1_DeletePDPContextResponse = 20,
94		/** Initiate PDP Context Activation Request */
95		GtpV1_InitiatePDPContextActivationRequest = 22,
96		/** Initiate PDP Context Activation Response */
97		GtpV1_InitiatePDPContextActivationResponse = 23,
98		/** Error Indication */
99		GtpV1_ErrorIndication = 26,
100		/** PDU Notification Request */
101		GtpV1_PDUNotificationRequest = 27,
102		/** PDU Notification Response */
103		GtpV1_PDUNotificationResponse = 28,
104		/** PDU Notification Reject Request */
105		GtpV1_PDUNotificationRejectRequest = 29,
106		/** PDU Notification Reject Response */
107		GtpV1_PDUNotificationRejectResponse = 30,
108		/** Supported Extensions Header Notification */
109		GtpV1_SupportedExtensionsHeaderNotification = 31,
110		/** Send Routing for GPRS Request */
111		GtpV1_SendRoutingforGPRSRequest = 32,
112		/** Send Routing for GPRS Response */
113		GtpV1_SendRoutingforGPRSResponse = 33,
114		/** Failure Report Request */
115		GtpV1_FailureReportRequest = 34,
116		/** Failure Report Response */
117		GtpV1_FailureReportResponse = 35,
118		/** Note MS Present Request */
119		GtpV1_NoteMSPresentRequest = 36,
120		/** Note MS Present Response */
121		GtpV1_NoteMSPresentResponse = 37,
122		/** Identification Request */
123		GtpV1_IdentificationRequest = 38,
124		/** Identification Response */
125		GtpV1_IdentificationResponse = 39,
126		/** SGSN Context Request */
127		GtpV1_SGSNContextRequest = 50,
128		/** SGSN Context Response */
129		GtpV1_SGSNContextResponse = 51,
130		/** SGSN Context Acknowledge */
131		GtpV1_SGSNContextAcknowledge = 52,
132		/** Forward Relocation Request */
133		GtpV1_ForwardRelocationRequest = 53,
134		/** Forward Relocation Response */
135		GtpV1_ForwardRelocationResponse = 54,
136		/** Forward Relocation Complete */
137		GtpV1_ForwardRelocationComplete = 55,
138		/** Relocation Cancel Request */
139		GtpV1_RelocationCancelRequest = 56,
140		/** Relocation Cancel Response */
141		GtpV1_RelocationCancelResponse = 57,
142		/** Forward SRNS Context */
143		GtpV1_ForwardSRNSContext = 58,
144		/** Forward Relocation Complete Acknowledge */
145		GtpV1_ForwardRelocationCompleteAcknowledge = 59,
146		/** Forward SRNS Context Acknowledge */
147		GtpV1_ForwardSRNSContextAcknowledge = 60,
148		/** UE Registration Request */
149		GtpV1_UERegistrationRequest = 61,
150		/** UE Registration Response */
151		GtpV1_UERegistrationResponse = 62,
152		/** RAN Information Relay */
153		GtpV1_RANInformationRelay = 70,
154		/** MBMS Notification Request */
155		GtpV1_MBMSNotificationRequest = 96,
156		/** MBMS Notification Response */
157		GtpV1_MBMSNotificationResponse = 97,
158		/** MBMS Notification Reject Request */
159		GtpV1_MBMSNotificationRejectRequest = 98,
160		/** MBMS Notification Reject Response */
161		GtpV1_MBMSNotificationRejectResponse = 99,
162		/** Create MBMS Notification Request */
163		GtpV1_CreateMBMSNotificationRequest = 100,
164		/** Create MBMS Notification Response */
165		GtpV1_CreateMBMSNotificationResponse = 101,
166		/** Update MBMS Notification Request */
167		GtpV1_UpdateMBMSNotificationRequest = 102,
168		/** Update MBMS Notification Response */
169		GtpV1_UpdateMBMSNotificationResponse = 103,
170		/** Delete MBMS Notification Request */
171		GtpV1_DeleteMBMSNotificationRequest = 104,
172		/** Delete MBMS Notification Response */
173		GtpV1_DeleteMBMSNotificationResponse = 105,
174		/** MBMS Registration Request */
175		GtpV1_MBMSRegistrationRequest = 112,
176		/** MBMS Registration Response */
177		GtpV1_MBMSRegistrationResponse = 113,
178		/** MBMS De-Registration Request */
179		GtpV1_MBMSDeRegistrationRequest = 114,
180		/** MBMS De-Registration Response */
181		GtpV1_MBMSDeRegistrationResponse = 115,
182		/** MBMS Session Start Request */
183		GtpV1_MBMSSessionStartRequest = 116,
184		/** MBMS Session Start Response */
185		GtpV1_MBMSSessionStartResponse = 117,
186		/** MBMS Session Stop Request */
187		GtpV1_MBMSSessionStopRequest = 118,
188		/** MBMS Session Stop Response */
189		GtpV1_MBMSSessionStopResponse = 119,
190		/** MBMS Session Update Request */
191		GtpV1_MBMSSessionUpdateRequest = 120,
192		/** MBMS Session Update Response */
193		GtpV1_MBMSSessionUpdateResponse = 121,
194		/** MS Info Change Request */
195		GtpV1_MSInfoChangeRequest = 128,
196		/** MS Info Change Response */
197		GtpV1_MSInfoChangeResponse = 129,
198		/** Data Record Transfer Request */
199		GtpV1_DataRecordTransferRequest = 240,
200		/** Data Record Transfer Response */
201		GtpV1_DataRecordTransferResponse = 241,
202		/** End Marker */
203		GtpV1_EndMarker = 254,
204		/** G-PDU */
205		GtpV1_GPDU = 255
206		};
207
208
209		/**
210		* @class GtpV1Layer
211		* A class representing the [GTP v1](https://en.wikipedia.org/wiki/GPRS_Tunnelling_Protocol) protocol.
212		*/
213		class GtpV1Layer : public Layer
214		{
215		private:
216		struct gtpv1_header_extra
217		{
218		uint16_t sequenceNumber;
219		uint8_t npduNumber;
220		uint8_t nextExtensionHeader;
221		};
222
223		gtpv1_header_extra* getHeaderExtra() const;
224
225		void init(GtpV1MessageType messageType, uint32_t teid, bool setSeqNum, uint16_t seqNum, bool setNpduNum, uint8_t npduNum);
226
227		public:
228
229		/**
230		* @class GtpExtension
231		* A class that represents [GTP header extensions](https://en.wikipedia.org/wiki/GPRS_Tunnelling_Protocol)
232		*/
233		class GtpExtension
234		{
235		friend class GtpV1Layer;
236
237		private:
238		uint8_t* m_Data;
239		size_t m_DataLen;
240		uint8_t m_ExtType;
241
242		GtpExtension(uint8_t* data, size_t dataLen, uint8_t type);
243
244		void setNextHeaderType(uint8_t nextHeaderType);
245
246		static GtpExtension createGtpExtension(uint8_t* data, size_t dataLen, uint8_t extType, uint16_t content);
247
248		public:
249
250		/**
251		* An empty c'tor that creates an empty object, meaning one that isNull() returns "true")
252		*/
253		GtpExtension();
254
255		/**
256		* A copy c'tor for this class
257		* @param[in] other The GTP extension to copy from
258		*/
259		GtpExtension(const GtpExtension& other);
260
261		/**
262		* An assignment operator for this class
263		* @param[in] other The extension to assign from
264		* @return A reference to the assignee
265		*/
266		GtpExtension& operator=(const GtpExtension& other);
267
268		/**
269		* @return Instances of this class may be initialized as empty, meaning they don't contain any data. In
270		* these cases this method returns true
271		*/
272		bool isNull() const;
273
274		/**
275		* @return The extension type. If the object is empty a value of zero is returned
276		*/
277		uint8_t getExtensionType() const;
278
279		/**
280		* @return The total length of the extension including the length and next extension type fields.
281		* If the object is empty a value of zero is returned
282		*/
283		size_t getTotalLength() const;
284
285		/**
286		* @return The length of the extension's content, excluding the extension length and next extension type fields.
287		* If the object is empty a value of zero is returned
288		*/
289		size_t getContentLength() const;
290
291		/**
292		* @return A byte array that includes the extension's content. The length of this array can be determined by
293		* getContentLength(). If the object is empty a null value is returned
294		*/
295		uint8_t* getContent() const;
296
297		/**
298		* @return The extension type of the next header. If there are no more header extensions or if this object is empty
299		* a value of zero is returned
300		*/
301		uint8_t getNextExtensionHeaderType() const;
302
303		/**
304		* @return An instance of this class representing the next extension header, if exists in the message. If there are
305		* no more header extensions or if this object is empty an empty instance of GtpExtension is returned, meaning
306		* one that GtpExtension#isNull() returns "true"
307		*/
308		GtpExtension getNextExtension() const;
309		}; // GtpExtension
310
311	0	virtual ~GtpV1Layer() {}
312
313		/** A constructor that creates the layer from an existing packet raw data
314		* @param[in] data A pointer to the raw data
315		* @param[in] dataLen Size of the data in bytes
316		* @param[in] prevLayer A pointer to the previous layer
317		* @param[in] packet A pointer to the Packet instance where layer will be stored in
318		*/
319	7.56k	GtpV1Layer(uint8_t* data, size_t dataLen, Layer* prevLayer, Packet* packet) : Layer(data, dataLen, prevLayer, packet) { m_Protocol = GTPv1; }
320
321		/**
322		* A constructor that creates a new GTPv1 layer and sets the message type and the TEID value
323		* @param[in] messageType The GTPv1 message type to be set in the newly created layer
324		* @param[in] teid The TEID value to be set in the newly created layer
325		*/
326		GtpV1Layer(GtpV1MessageType messageType, uint32_t teid);
327
328		/**
329		* A constructor that creates a new GTPv1 layer and sets various parameters
330		* @param[in] messageType The GTPv1 message type to be set in the newly created layer
331		* @param[in] teid The TEID value to be set in the newly created layer
332		* @param[in] setSeqNum A flag indicating whether to set a sequence number. If set to "false" then the parameter "seqNum" will be ignored
333		* @param[in] seqNum The sequence number to be set in the newly created later. If "setSeqNum" is set to false this parameter will be ignored
334		* @param[in] setNpduNum A flag indicating whether to set the N-PDU number. If set to "false" then the parameter "npduNum" will be ignored
335		* @param[in] npduNum The N-PDU number to be set in the newly created later. If "setNpduNum" is set to false this parameter will be ignored
336		*/
337		GtpV1Layer(GtpV1MessageType messageType, uint32_t teid, bool setSeqNum, uint16_t seqNum, bool setNpduNum, uint8_t npduNum);
338
339		/**
340		* A static method that takes a byte array and detects whether it is a GTP v1 message
341		* @param[in] data A byte array
342		* @param[in] dataSize The byte array size (in bytes)
343		* @return True if the data is identified as GTP v1 message (GTP-C or GTP-U)
344		*/
345		static bool isGTPv1(const uint8_t* data, size_t dataSize);
346
347		/**
348		* @return The GTP v1 common header structure. Notice this points directly to the data, so every change will change the actual packet data
349		*/
350	20.3k	gtpv1_header* getHeader() const { return (gtpv1_header*)m_Data; }
351
352		/**
353		* Get the sequence number if exists on the message (sequence number is an optional field in GTP messages)
354		* @param[out] seqNumber Set with the sequence number value if exists in the layer. Otherwise remains unchanged
355		* @return True if the sequence number field exists in layer, in which case seqNumber is set with the value.
356		* Or false otherwise
357		*/
358		bool getSequenceNumber(uint16_t& seqNumber) const;
359
360		/**
361		* Set a sequence number
362		* @param[in] seqNumber The sequence number to set
363		* @return True if the value was set successfully, false otherwise. In case of failure a corresponding error message will be written to log
364		*/
365		bool setSequenceNumber(const uint16_t seqNumber);
366
367		/**
368		* Get the N-PDU number if exists on the message (N-PDU number is an optional field in GTP messages)
369		* @param[out] npduNum Set with the N-PDU number value if exists in the layer. Otherwise remains unchanged
370		* @return True if the N-PDU number field exists in layer, in which case npduNum is set with the value.
371		* Or false otherwise
372		*/
373		bool getNpduNumber(uint8_t& npduNum) const;
374
375		/**
376		* Set an N-PDU number
377		* @param[in] npduNum The N-PDU number to set
378		* @return True if the value was set successfully, false otherwise. In case of failure a corresponding error message will be written to log
379		*/
380		bool setNpduNumber(const uint8_t npduNum);
381
382		/**
383		* Get the type of the next header extension if exists on the message (extensions are optional in GTP messages)
384		* @param[out] nextExtType Set with the next header extension type if exists in layer. Otherwise remains unchanged
385		* @return True if the message contains header extensions, in which case nextExtType is set to the next
386		* header extension type. If there are no header extensions false is returned and nextExtType remains unchanged
387		*/
388		bool getNextExtensionHeaderType(uint8_t& nextExtType) const;
389
390		/**
391		* @return An object that represents the next extension header, if exists in the message. If there are no extensions
392		* an empty object is returned, meaning an object which GtpExtension#isNull() returns "true"
393		*/
394		GtpExtension getNextExtension() const;
395
396		/**
397		* Add a GTPv1 header extension. It is assumed that the extension is 4 bytes in length and its content is 2 bytes in length.
398		* If you need a different content size please reach out to me. This method takes care of extending the layer to make room for
399		* the new extension and also sets the relevant flags and fields
400		* @param[in] extensionType The type of the new extension
401		* @param[in] extensionContent A 2-byte long content
402		* @return An object representing the newly added extension. If there was an error adding the extension a null object will be
403		* returned (meaning GtpExtension#isNull() will return "true") and a corresponding error message will be written to log
404		*/
405		GtpExtension addExtension(uint8_t extensionType, uint16_t extensionContent);
406
407		/**
408		* @return The message type of this GTP packet
409		*/
410		GtpV1MessageType getMessageType() const;
411
412		/**
413		* @return A string representation of the packet's message type
414		*/
415		std::string getMessageTypeAsString() const;
416
417		/**
418		* @return True if this is a GTP-U message, false otherwise
419		*/
420		bool isGTPUMessage() const;
421
422		/**
423		* @return True if this is a GTP-C message, false otherwise
424		*/
425		bool isGTPCMessage() const;
426
427		/**
428		* A static method that checks whether the port is considered as GTPv1
429		* @param[in] port The port number to be checked
430		* @return True if the port matches those associated with the BGP protocol
431		*/
432	48.7k	static bool isGTPv1Port(uint16_t port) { return port == 2152 /* GTP-U / \|\| port == 2123 / GTP-C */; }
433
434
435		// implement abstract methods
436
437		/**
438		* Identifies the following next layers for GTP-U packets: IPv4Layer, IPv6Layer. Otherwise sets PayloadLayer
439		*/
440		void parseNextLayer();
441
442		/**
443		* @return The size of the GTP header. For GTP-C packets the size is determined by the value of
444		* gtpv1_header#messageLength and for GTP-U the size only includes the GTP header itself (meaning
445		* the size of gtpv1_header plus the size of the optional fields such as sequence number, N-PDU
446		* or extensions if exist)
447		*/
448		size_t getHeaderLen() const;
449
450		/**
451		* Calculate the following fields:
452		* - gtpv1_header#messageLength
453		*/
454		void computeCalculateFields();
455
456		std::string toString() const;
457
458	7.56k	OsiModelLayer getOsiModelLayer() const { return OsiModelTransportLayer; }
459		};
460		}
461
462		#endif //PACKETPP_GTP_LAYER