README
¶
Overview
This package provides a module for the GPRS Tunnel Protocol (GTP) version 2. GTPv2 is documented in 3GPP TS 29.274.
Installation
go get github.com/blorticus/gtpv2
Basic Usage
package main
import (
gtpv2 "github.com/blorticus/gtpv2"
"net"
"fmt"
)
func main() {
modifyBearerRequest := gtpv2.NewPDU(gtpv2.ModifyBearerRequest, 0x00001acc, []*gtpv2.IE{
gtpv2.NewIEWithRawData(gtpv2.UserLocationInformation, []byte{
0x18, 0x00, 0x11, 0x00, 0xff, 0x00, 0x00, 0x11,
0x00, 0x0f, 0x42, 0x4d, 0x00,
}),
gtpv2.NewIEWithRawData(gtpv2.RATType, []byte{0x06}),
gtpv2.NewIEWithRawData(gtpv2.DelayValue, []byte{0x00}),
gtpv2.NewIEWithRawData(gtpv2.BearerContext, []byte{
0x49, 0x00, 0x01, 0x00, 0x05, 0x57, 0x00, 0x09,
0x00, 0x80, 0xe4, 0x03, 0xfb, 0x94, 0xac, 0x13,
0x01, 0xb2,
}),
gtpv2.NewIEWithRawData(gtpv2.RecoveryRestartCounter, []byte{0x95}),
})
conn, err := net.Dial("udp", "10.1.10.10:2123")
if err != nil {
panic(err)
}
conn.Write(modifyBearerRequest.Encode())
incomingByteStream := make([]byte, 65536)
dgLength, err := conn.Read(incomingByteStream)
if err != nil {
panic(err)
}
incomingGtpPDU, piggybackedGtpPDU, err := gtpv2.DecodePDU(incomingByteStream[:dgLength])
if err != nil {
panic(err)
}
for _, ie := range incomingGtpPDU.InformationElements {
fmt.Printf("IE name = (%s), value = (%02x)\n", gtpv2.NameOfIEForType(ie.Type), ie.Data)
}
}
Information Elements
There is no support for interpretation of Information Elements. They are created, stored, and presented as a byte stream. So, for example, when one uses the IMSI IE, it is not decoded to its natural string representation.
Documentation
¶
Index ¶
- Constants
- func DecodePDU(stream []byte) (pdu *PDU, piggybackedPdu *PDU, err error)
- func NameOfIEForType(ieType IEType) string
- func NameOfMessageForType(msgType MessageType) string
- type GtpDefinitionRootYaml
- type Gtpv2PduYaml
- type IE
- func DecodeIE(stream []byte) (*IE, error)
- func ExtractGroupedIEsFrom(groupedIE *IE) ([]*IE, error)
- func NewGroupedIE(ieType IEType, groupedIEs []*IE) *IE
- func NewGroupedIEErrorable(ieType IEType, groupedIEs []*IE) (*IE, error)
- func NewIEWithRawData(ieType IEType, data []byte) *IE
- func NewIEWithRawDataErrorable(ieType IEType, data []byte) (*IE, error)
- type IEType
- type IEYaml
- type MessageType
- type PDU
- type Template
- type TypedFTEID
- type TypedIE
- type TypedIMSI
Constants ¶
const ( InternationalMobileSubscriberIdentity = 1 IMSI = 1 Cause = 2 RecoveryRestartCounter = 3 STNSR = 51 AccessPointName = 71 APN = 71 AggregateMaximumBitRate = 72 AMBR = 72 EPSBearerID = 73 EBI = 73 IPAddress = 74 MobileEquipmentIdentity = 75 MEI = 75 MSISDN = 76 Indication = 77 ProtocolConfigurationOptions = 78 PCI = 78 PDNAddressAllocation = 79 PAA = 79 BearerLevelQualityofService = 80 BearerQoS = 80 FlowQualityofService = 81 FlowQoS = 81 RATType = 82 ServingNetwork = 83 EPSBearerLevelTrafficFlowTemplate = 84 BearerTFT = 84 TrafficAggregationDescription = 85 TAD = 85 UserLocationInformation = 86 ULI = 86 FullyQualifiedTunnelEndpointIdentifier = 87 FTEID = 87 TMSI = 88 GlobalCNId = 89 S103PDNDataForwardingInfo = 90 S103PDF = 90 S1UDataForwardingInfo = 91 S1UDF = 91 DelayValue = 92 BearerContext = 93 ChargingID = 94 ChargingCharacteristics = 95 TraceInformation = 96 BearerFlags = 97 PDNType = 99 ProcedureTransactionID = 100 MMContextGSMKeyandTriplets = 103 MMContextUMTSKeyUsedCipherandQuintuplets = 104 MMContextGSMKeyUsedCipherandQuintuplets = 105 MMContextUMTSKeyandQuintuplets = 106 MMContextEPSSecurityContextQuadrupletsandQuintuplets = 107 MMContextUMTSKeyQuadrupletsandQuintuplets = 108 PDNConnection = 109 PDUNumbers = 110 PTMSI = 111 PTMSISignature = 112 HopCounter = 113 UETimeZone = 114 TraceReference = 115 CompleteRequestMessage = 116 GUTI = 117 FContainer = 118 FCause = 119 PLMNID = 120 TargetIdentification = 121 PacketFlowID = 123 RABContext = 124 SourceRNCPDCPContextInfo = 125 PortNumber = 126 APNRestriction = 127 SelectionMode = 128 SourceIdentification = 129 ChangeReportingAction = 131 FullyQualifiedPDNConnectionSetIdentifier = 132 FQCSID = 132 Channelneeded = 133 NodeType = 135 FullyQualifiedDomainName = 136 FQDN = 136 TransactionIdentifier = 137 TI = 137 MBMSSessionDuration = 138 MBMSServiceArea = 139 MBMSSessionIdentifier = 140 MBMSFlowIdentifier = 141 MBMSIPMulticastDistribution = 142 MBMSDistributionAcknowledge = 143 RFSPIndex = 144 UserCSGInformation = 145 UCI = 145 CSGInformationReportingAction = 146 CSGID = 147 CSGMembershipIndication = 148 CMI = 148 Serviceindicator = 149 DetachType = 150 LocalDistiguishedName = 151 LDN = 151 NodeFeatures = 152 MBMSTimetoDataTransfer = 153 Throttling = 154 AllocationRetentionPriority = 155 ARP = 155 EPCTimer = 156 SignallingPriorityIndication = 157 TemporaryMobileGroupIdentity = 158 TMGI = 158 AdditionalMMcontextforSRVCC = 159 AdditionalflagsforSRVCC = 160 MDTConfiguration = 162 AdditionalProtocolConfigurationOptions = 163 APCO = 163 AbsoluteTimeofMBMSDataTransfer = 164 HeNBInformationReporting = 165 IPv4ConfigurationParameters = 166 IP4CP = 166 ChangetoReportFlags = 167 ActionIndication = 168 TWANIdentifier = 169 ULITimestamp = 170 MBMSFlags = 171 RANNASCause = 172 CNOperatorSelectionEntity = 173 TrustedWLANModeIndication = 174 NodeNumber = 175 NodeIdentifier = 176 PresenceReportingAreaAction = 177 PresenceReportingAreaInformation = 178 TWANIdentifierTimestamp = 179 OverloadControlInformation = 180 LoadControlInformation = 181 Metric = 182 SequenceNumber = 183 APNandRelativeCapacity = 184 WLANOffloadabilityIndication = 185 PagingandServiceInformation = 186 IntegerNumber = 187 MillisecondTimeStamp = 188 MonitoringEventInformation = 189 ECGIList = 190 RemoteUEContext = 191 RemoteUserID = 192 RemoteUEIPinformation = 193 CIoTOptimizationsSupportIndication = 194 SCEFPDNConnection = 195 HeaderCompressionConfiguration = 196 ExtendedProtocolConfigurationOptions = 197 ServingPLMNRateControl = 198 Counter = 199 MappedUEUsageType = 200 SecondaryRATUsageDataReport = 201 UPFunctionSelectionIndicationFlags = 202 ExtensionType = 254 PrivateExtension = 255 )
These represent possible GTPv2 IE types. In some cases, includes the full name and its abbreviation (e.g., for IMSI)
Variables ¶
This section is empty.
Functions ¶
func DecodePDU ¶
DecodePDU decodes a stream of bytes that contain either exactly one well-formed GTPv2 PDU, or two GTPv2 PDUs when the piggyback flag on the first is set to true. Returns an error if the stream cannot be decoded into one or two PDUs.
func NameOfIEForType ¶
NameOfIEForType returns a string identifier (from TS 29.274 section 8.1) for a GTPv2 IE based on the type integer
func NameOfMessageForType ¶
func NameOfMessageForType(msgType MessageType) string
NameOfMessageForType returns a string identifier (from TS 29.274 section 8.1) for a GTPv2 IE based on the type integer value
Types ¶
type GtpDefinitionRootYaml ¶
type GtpDefinitionRootYaml struct {
Gtpv2Pdus []Gtpv2PduYaml
}
type Gtpv2PduYaml ¶
type IE ¶
IE is a GTPv2 Information Element. DataLength is the length of just the contained data, in bytes. TotalLength is the DataLength plus the header length. InstanceNumber is actually uint4. Data is the BigEndian data bytes.
func DecodeIE ¶
DecodeIE consumes bytes from the start of stream to produce a GTPv2 IE. The TotalLength field of the resulting IE provides the count of bytes from stream that are consumed to produce this IE. Return an error if decoding fails.
func ExtractGroupedIEsFrom ¶ added in v0.1.1
func NewGroupedIE ¶
NewGroupedIE is a convenience method to generate a grouped IE (e.g., BearerContext) from IE sub-elements inside the group. Panics if an error occurs.
func NewGroupedIEErrorable ¶
NewGroupedIEErrorable is the same as NewGroupedIE(), but returns an error if one occurs, rather than panicing.
func NewIEWithRawData ¶
NewIEWithRawData creates a new GTPv2 IE, providing it with the data as a raw byte array. The data are not validated for length or value. The instance number is set to 0, but may be changed directly or as the result of encoding order. The data are not copied, so if you require that, you must manually copy() the data first. The data must be in network byte order (i.e., big endian order). This method panics on an error. Use NewV2IEWithRawDataErrorable() to make the error catchable.
func NewIEWithRawDataErrorable ¶
NewIEWithRawDataErrorable does the same as NewV2IEWithRawData() but returns an error if it occurs, rather than panicing.
func (*IE) Encode ¶
Encode encodes the Information Element as a series of bytes in network byte order. There is no effort to validate that the IE Data field is correct for the type. This permits the creation of structurally correct but semantically incorrect. The IE TotalLength field is ignored for encoding and the actual length is recalculated.
func (*IE) TypedDataErrorable ¶
type MessageType ¶
type MessageType uint8
MessageType represents possible GTPv2 message type values
const ( EchoRequest MessageType = 1 EchoResponse MessageType = 2 CreateSessionRequest MessageType = 32 CreateSessionResponse MessageType = 33 ModifyBearerRequest MessageType = 34 ModifyBearerResponse MessageType = 35 DeleteSessionRequest MessageType = 36 DeleteSessionResponse MessageType = 37 RemoteUEReportNotification MessageType = 40 RemoteUEReportAcknowlegement MessageType = 41 ChangeNotificationRequest MessageType = 38 ChangeNotificationResponse MessageType = 39 ModifyBearerCommand MessageType = 64 ModifyBearerFailureIndication MessageType = 65 DeleteBearerCommand MessageType = 66 DeleteBearerFailureIndication MessageType = 67 BearerResourceCommand MessageType = 68 BearerResourceFailureIndication MessageType = 69 DownlinkDataNotificationFailureIndication MessageType = 70 TraceSessionActivation MessageType = 71 TraceSessionDeactivation MessageType = 72 StopPagingIndication MessageType = 73 CreateBearerRequest MessageType = 95 CreateBearerResponse MessageType = 96 UpdateBearerRequest MessageType = 97 UpdateBearerResponse MessageType = 98 DeleteBearerRequest MessageType = 99 DeleteBearerResponse MessageType = 100 DeletePDNConnectionSetRequest MessageType = 101 DeletePDNConnectionSetResponse MessageType = 102 PGWDownlinkTriggeringNotification MessageType = 103 PGWDownlinkTriggeringAcknowledge MessageType = 104 IdentificationRequest MessageType = 128 IdentificationResponse MessageType = 129 ContextRequest MessageType = 130 ContextResponse MessageType = 131 ContextAcknowledge MessageType = 132 ForwardRelocationRequest MessageType = 133 ForwardRelocationResponse MessageType = 134 ForwardRelocationCompleteNotification MessageType = 135 ForwardRelocationCompleteAcknowledge MessageType = 136 ForwardAccessContextNotification MessageType = 137 ForwardAccessContextAcknowledge MessageType = 138 RelocationCancelRequest MessageType = 139 RelocationCancelResponse MessageType = 140 ConfigurationTransferTunnel MessageType = 141 DetachNotification MessageType = 149 DetachAcknowledge MessageType = 150 CSPagingIndication MessageType = 151 RANInformationRelay MessageType = 152 AlertMMENotification MessageType = 153 AlertMMEAcknowledge MessageType = 154 UEActivityNotification MessageType = 155 UEActivityAcknowledge MessageType = 156 ISRStatusIndication MessageType = 157 UERegistrationQueryRequest MessageType = 158 UERegistrationQueryResponse MessageType = 159 CreateForwardingTunnelRequest MessageType = 160 CreateForwardingTunnelResponse MessageType = 161 SuspendNotification MessageType = 162 SuspendAcknowledge MessageType = 163 ResumeNotification MessageType = 164 ResumeAcknowledge MessageType = 165 CreateIndirectDataForwardingTunnelRequest MessageType = 166 CreateIndirectDataForwardingTunnelResponse MessageType = 167 DeleteIndirectDataForwardingTunnelRequest MessageType = 168 DeleteIndirectDataForwardingTunnelResponse MessageType = 169 ReleaseAccessBearersRequest MessageType = 170 ReleaseAccessBearersResponse MessageType = 171 DownlinkDataNotification MessageType = 176 DownlinkDataNotificationAcknowledge MessageType = 177 PGWRestartNotification MessageType = 179 PGWRestartNotificationAcknowledge MessageType = 180 UpdatePDNConnectionSetRequest MessageType = 200 UpdatePDNConnectionSetResponse MessageType = 201 )
GTPv2 MessageTypes
type PDU ¶
type PDU struct {
IsCarryingPiggybackedPDU bool
TEIDFieldIsPresent bool
PriorityFieldIsPresent bool
Type MessageType
TotalLength uint16
TEID uint32
SequenceNumber uint32
Priority uint8
InformationElements []*IE
}
PDU represents a GTPv2 PDU. Version field is omitted because it is always '2'. TEID should be 0 if TEIDFieldIsPresent is false. Similarly, Priority should be 0 if PriorityFieldIsPresent is false. TotalLength includes complete header length, and body length, but does not include a piggybacked message length if IsCarryingPiggybackedPDU is true. The SequenceNumber is actually a uint24 value. Priority is actually a uint4 value. For these two, upper bits beyond the actual encode size are ignored and should be zero.
func NewPDU ¶
func NewPDU(pduType MessageType, sequenceNumber uint32, ies []*IE) *PDU
NewPDU constructs a new base GTPv2 PDU. It uses a builder pattern to add non-mandatory elements, including a TEID and a priority. A piggybacked PDU is added at the time of encoding and revealed on decoding. If you change struct values after construction, Encode() may not operate as expected and may even panic, so the struct values should usually be treated as read-only. This version of the constructor will panic if the length of the IEs exceeds the maximum PDU length. If you want to be able to catch this condition, construct the PDU struct manually.
func (*PDU) AddPriority ¶
AddPriority sets the priority field and the priority presence flag
type Template ¶
type Template struct {
// contains filtered or unexported fields
}
t := gtpv2.ReadYamlTemplateFromFile( "/path/to/file.yaml" ) csr := t.GeneratePDUByName( "CSR01" )
type TypedFTEID ¶
TypedFTEID is a structured version of an F-TEID IE
func (*TypedFTEID) ToIE ¶
func (fteid *TypedFTEID) ToIE() *IE
ToIE creates an IE from the structured version of an F-TEID, and panics if there is an error
func (*TypedFTEID) ToIEErrorable ¶
func (fteid *TypedFTEID) ToIEErrorable() (*IE, error)
ToIEErrorable is the same as ToIE, but returns an error if one occurs, rather than panicing
type TypedIMSI ¶
type TypedIMSI struct {
AsString string
}
TypedIMSI is a structured version of an IMSI IE
func (*TypedIMSI) ToIE ¶
ToIE creates an IE from the structured version of an F-TEID, and panics if there is an error
func (*TypedIMSI) ToIEErrorable ¶
ToIEErrorable is the same as ToIE, but returns an error if one occurs, rather than panicing
Source Files