README
¶
v1: GTPv1 in Golang
Package v1 provides simple and painless handling of GTPv1-C and GTPv1-U protocols in pure Golang.
Getting Started
This package is still under construction. The networking feature is only available for GTPv1-U. GTPv1-C feature would be available in the future.
See message and ie directory for what you can do with the current implementation.
Creating a PDP Context as a client
NOT IMPLEMENTED YET!
Waiting for a PDP Context to be created as a server
NOT IMPLEMENTED YET!
Opening a U-Plane connection
Retrieve UPlaneConn first, using DialUPlane (for client) or NewUPlaneConn (for server).
Client
DialUPlane sends Echo Request and returns UPlaneConn if it succeeds.
If you don't need Echo, see Server section. As GTP is UDP-based connection, and there are no session management on UPlaneConn, the behavior of Dial and ListenAndServe is not quite different.
uConn, err := v1.Dial(ctx, laddr, raddr)
if err != nil {
// ...
}
defer uConn.Close()
Server
Retrieve UPlaneConn with NewUPlaneConn, and ListenAndServe to start listening.
uConn := v1.NewUPlaneConn(laddr)
if err != nil {
// ...
}
defer uConn.Close()
// This blocks, and returns an error when it's fatal.
if err := uConn.ListenAndServe(ctx); err != nil {
// ...
}
Manupulating UPlaneConn
With UPlaneConn, you can add and delete tunnels, and manipulate device directly.
Using Linux Kernel GTP-U
Linux Kernel GTP-U is quite performant and easy to handle, but it requires root privilege, and of course it works only on Linux. So it is disabled by default. To get started, enable it first. Note that it cannot be disabled while the program is working.
if err := uConn.EnableKernelGTP("gtp0", v1.roleSGSN); err != nil {
// ...
}
Then, when the bearer information is ready, use AddTunnel or AddTunnelOverride to add a tunnel.
The latter one deletes the existing tunnel with the same IP and/or incoming TEID before creating a tunnel,
while the former fails if there's any duplication.
// add a tunnel by giving GTP peer's IP, subscriber's IP,
if err := uConn.AddTunnelOverride(
net.ParseIP("10.10.10.10"), // GTP peer's IP
net.ParseIP("1.1.1.1"), // subscriber's IP
0x55667788, // outgoing TEID
0x11223344, // incoming TEID
); err != nil {
// ...
}
When the tunnel is no longer necessary, use DelTunnelByITEI or DelTunnelByMSAddress to delete it.
Or, by Close-ing the UPlaneConn, all the tunnels associated will the cleared.
// delete a tunnel by giving an incoming TEID.
if err := uConn.DelTunnelByITEI(0x11223344); err != nil {
// ...
}
// delete a tunnel by giving an IP address assigned to a subscriber.
if err := uConn.DelTunnelByMSAddress(net.ParseIP("1.1.1.1")); err != nil {
// ...
}
The packets NOT forwarded by the Kernel can be handled automatically by giving a handler to UPlaneConn.
Handlers for T-PDU, Echo Request/Response, and Error Indication are registered by default, but you can override them using AddHandler.
uConn.AddHandler(message.MsgTypeEchoRequest, func(c v1.Conn, senderAddr net.Addr, msg message.Message) error {
// do anything you want for Echo Request here.
// errors returned here are passed to `errCh` that is given to UPlaneConn at the beginning.
return nil
})
If the tunnel with appropriate IP or TEID is not found for a T-PDU packet, Kernel sends it to userland. You can manipulate it with ReadFromGTP.
buf := make([]byte, 1500)
// the 3rd returned value is TEID in GTPv1-U Header.
n, raddr, teid, err := uConn.ReadFromGTP(buf)
if err != nil {
// ...
}
fmt.Printf("%x", buf[:n]) // prints only the payload, no GTP header included.
Also, you can send any payload by using WriteToGTP. It writes the given payload with GTP header to the specified addr over UPlaneConn.
// first return value is the number of bytes written.
if _, err := uConn.WriteToGTP(teid, payload, addr); err != nil {
// ...
}
Using userland GTP-U
Note: package v1 does provide the encapsulation/decapsulation and some networking features, but it does NOT provide routing of the decapsulated packets, nor capturing IP layer and above on the specified interface. This is because such kind of operations cannot be done without platform-specific codes.
You can use to ReadFromGTP read the packets coming into uConn. This does not work for the packets which are handled by RelayTo.
buf := make([]byte, 1500)
n, raddr, teid, err := uConn.ReadFromGTP(buf)
if err != nil {
// ...
}
fmt.Printf("%x", buf[:n]) // prints the payload encapsulated in the GTP header.
Also, you can send any payload by using WriteToGTP. It writes the given payload with GTP header to the specified addr over UPlaneConn.
// first return value is the number of bytes written.
if _, err := uConn.WriteToGTP(teid, payload, addr); err != nil {
// ...
}
Especially or SGSN/S-GW-ish nodes(=have multiple GTP tunnels and its raison d'être is just to forward traffic right to left/left to right) we provide a method to swap TEID and forward T-PDU packets automatically and efficiently.
By using RelayTo, the UPlaneConn automatically handles the T-PDU packet in background with the least cost. Note that it's performed on the userland and thus it's not so performant.
// this is the example for S-GW that completed establishing a session and ready to forward U-Plane packets.
s1uConn.RelayTo(s5uConn, s1usgwTEID, s5uBearer.OutgoingTEID, s5uBearer.RemoteAddress)
s5uConn.RelayTo(s1uConn, s5usgwTEID, s1uBearer.OutgoingTEID, s1uBearer.RemoteAddress)
Handling Extension Headers
AddExtensionHeaders adds ExtensionHeader(s) to the Header of a Message, set the E flag, and checks if the types given are consistent (error will be returned if not).
msg := message.NewTPDU(0x11223344, []byte{0xde, 0xad, 0xbe, 0xef})
if err := msg.AddExtensionHeaders(
// We don't support construction of the specific type of an ExtensionHeader.
// The second parameter should be the serialized bytes of contents.
message.NewExtensionHeader(
message.ExtHeaderTypeUDPPort,
[]byte{0x22, 0xb8},
message.ExtHeaderTypePDUSessionContainer,
),
message.NewExtensionHeader(
message.ExtHeaderTypePDUSessionContainer,
[]byte{0x00, 0xc2},
message.ExtHeaderTypeNoMoreExtensionHeaders,
),
); err != nil {
// ...
}
ExtensionHeaders decoded or added are stored in ExtensionHeaders field in the Header, which can be accessed like this.
// no need to write msg.Header.ExtensionHeaders, as the Header is embedded in messages.
for _, eh := range msg.ExtensionHeaders {
log.Println(eh.Type) // ExtensionHeader type has its own Type while it's not actually included in a packet.
log.Println(eh.Content) // We do not support decoding of each type of content yet. Decode them on your own.
log.Println(eh.NextType) // Don't sort the slice - it ruins the packet, or even cause a panic.
}
When you are directly manipulating a Header for some reason, WithExtensionHeaders would help you simplify your operation.
Be sure not to call it on a Message, as it returns *Header, not a Message interface.
header := message.NewHeader(
0x30, // no need to set E flag here - With... method will do that instead.
message.MsgTypeEchoRequest,
0xdeadbeef,
0x00,
[]byte{0xde, 0xad, 0xbe, 0xef},
).WithExtensionHeaders(
message.NewExtensionHeader(
message.ExtHeaderTypeUDPPort,
[]byte{0x22, 0xb8},
message.ExtHeaderTypePDUSessionContainer,
),
message.NewExtensionHeader(
message.ExtHeaderTypePDUSessionContainer,
[]byte{0x00, 0xc2},
message.ExtHeaderTypeNoMoreExtensionHeaders,
),
)
Supported Features
Messages
The following Messages marked with "Yes" are currently available with their own useful constructors.
Even there are some missing Messages, you can create any kind of Message by using message.NewGeneric.
| ID | Name | Supported |
|---|---|---|
| 0 | (Spare/Reserved) | - |
| 1 | Echo Request | Yes |
| 2 | Echo Response | Yes |
| 3 | Version Not Supported | Yes |
| 4 | Node Alive Request | |
| 5 | Node Alive Response | |
| 6 | Redirection Request | |
| 7 | Redirection Response | |
| 8-15 | (Spare/Reserved) | - |
| 16 | Create PDP Context Request | Yes |
| 17 | Create PDP Context Response | Yes |
| 18 | Update PDP Context Request | Yes |
| 19 | Update PDP Context Response | Yes |
| 20 | Delete PDP Context Request | Yes |
| 21 | Delete PDP Context Response | Yes |
| 22 | Initiate PDP Context Activation Request | |
| 23 | Initiate PDP Context Activation Response | |
| 24-25 | (Spare/Reserved) | - |
| 26 | Error Indication | Yes |
| 27 | PDU Notification Request | |
| 28 | PDU Notification Response | |
| 29 | PDU Notification Reject Request | |
| 30 | PDU Notification Reject Response | |
| 31 | Supported Extension Headers Notification | Yes |
| 32 | Send Routeing Information for GPRS Request | |
| 33 | Send Routeing Information for GPRS Response | |
| 34 | Failure Report Request | |
| 35 | Failure Report Response | |
| 36 | Note MS GPRS Present Request | |
| 37 | Note MS GPRS Present Response | |
| 38-47 | (Spare/Reserved) | - |
| 48 | Identification Request | |
| 49 | Identification Response | |
| 50 | SGSN Context Request | |
| 51 | SGSN Context Response | |
| 52 | SGSN Context Acknowledge | |
| 53 | Forward Relocation Request | |
| 54 | Forward Relocation Response | |
| 55 | Forward Relocation Complete | |
| 56 | Relocation Cancel Request | |
| 57 | Relocation Cancel Response | |
| 58 | Forward SRNS Context | |
| 59 | Forward Relocation Complete Acknowledge | |
| 60 | Forward SRNS Context Acknowledge | |
| 61 | UE Registration Query Request | |
| 62 | UE Registration Query Response | |
| 63-69 | (Spare/Reserved) | - |
| 70 | RAN Information Relay | |
| 71-95 | (Spare/Reserved) | - |
| 96 | MBMS Notification Request | |
| 97 | MBMS Notification Response | |
| 98 | MBMS Notification Reject Request | |
| 99 | MBMS Notification Reject Response | |
| 100 | Create MBMS Context Request | |
| 101 | Create MBMS Context Response | |
| 102 | Update MBMS Context Request | |
| 103 | Update MBMS Context Response | |
| 104 | Delete MBMS Context Request | |
| 105 | Delete MBMS Context Response | |
| 106 - 111 | (Spare/Reserved) | - |
| 112 | MBMS Registration Request | |
| 113 | MBMS Registration Response | |
| 114 | MBMS De-Registration Request | |
| 115 | MBMS De-Registration Response | |
| 116 | MBMS Session Start Request | |
| 117 | MBMS Session Start Response | |
| 118 | MBMS Session Stop Request | |
| 119 | MBMS Session Stop Response | |
| 120 | MBMS Session Update Request | |
| 121 | MBMS Session Update Response | |
| 122-127 | (Spare/Reserved) | - |
| 128 | MS Info Change Notification Request | |
| 129 | MS Info Change Notification Response | |
| 130-239 | (Spare/Reserved) | - |
| 240 | Data Record Transfer Request | |
| 241 | Data Record Transfer Response | |
| 242-253 | (Spare/Reserved) | - |
| 254 | End Marker | |
| 255 | G-PDU | Yes |
Information Elements
The following Information Elements marked with "Yes" are currently supported with their own useful constructors.
Even there are some missing IEs, you can create any kind of IEs by using ie.New function or by initializing ie.IE directly.
| ID | Name | Supported |
|---|---|---|
| 0 | (Spare/Reserved) | - |
| 1 | Cause | Yes |
| 2 | IMSI | Yes |
| 3 | Routeing Area Identity | Yes |
| 4 | Temporary Logical Link Identity | |
| 5 | Packet TMSI | Yes |
| 6 | (Spare/Reserved) | - |
| 7 | (Spare/Reserved) | - |
| 8 | Reordering Required | Yes |
| 9 | Authentication Triplet | Yes |
| 10 | (Spare/Reserved) | - |
| 11 | MAP Cause | Yes |
| 12 | P-TMSI Signature | Yes |
| 13 | MS Validated | Yes |
| 14 | Recovery | Yes |
| 15 | Selection Mode | Yes |
| 16 | TEID Data I | Yes |
| 17 | TEID C-Plane | Yes |
| 18 | TEID Data II | Yes |
| 19 | Teardown Indication | Yes |
| 20 | NSAPI | Yes |
| 21 | RANAP Cause | Yes |
| 22 | RAB Context | |
| 23 | Radio Priority SMS | |
| 24 | Radio Priority | |
| 25 | Packet Flow ID | |
| 26 | Charging Characteristics | |
| 27 | Trace Reference | |
| 28 | Trace Type | |
| 29 | MS Not Reachable Reason | |
| 30-126 | (Spare/Reserved) | - |
| 127 | Charging ID | Yes |
| 128 | End User Address | Yes |
| 129 | MM Context | |
| 130 | PDP Context | |
| 131 | Access Point Name | Yes |
| 132 | Protocol Configuration Options | Yes |
| 133 | GSN Address | Yes |
| 134 | MSISDN | Yes |
| 135 | QoS Profile | |
| 136 | Authentication Quintuplet | Yes |
| 137 | Traffic Flow Template | |
| 138 | Target Identification | |
| 139 | UTRAN Transparent Container | |
| 140 | RAB Setup Information | |
| 141 | Extension Header Type List | Yes |
| 142 | Trigger Id | |
| 143 | OMC Identity | |
| 144 | RAN Transparent Container | |
| 145 | PDP Context Prioritization | |
| 146 | Additional RAB Setup Information | |
| 147 | SGSN Number | |
| 148 | Common Flags | Yes |
| 149 | APN Restriction | Yes |
| 150 | Radio Priority LCS | |
| 151 | RAT Type | Yes |
| 152 | User Location Information | Yes |
| 153 | MS Time Zone | Yes |
| 154 | IMEISV | Yes |
| 155 | CAMEL Charging Information Container | |
| 156 | MBMS UE Context | |
| 157 | Temporary Mobile Group Identity | |
| 158 | RIM Routing Address | |
| 159 | MBMS Protocol Configuration Options | |
| 160 | MBMS Service Area | |
| 161 | Source RNC PDCP Context Info | |
| 162 | Additional Trace Info | |
| 163 | Hop Counter | |
| 164 | Selected PLMN Id | |
| 165 | MBMS Session Identifier | |
| 166 | MBMS 2G/3G Indicator | |
| 167 | Enhanced NSAPI | |
| 168 | MBMS Session Duration | |
| 169 | Additional MBMS Trace Info | |
| 170 | MBMS Session Repetition Number | |
| 171 | MBMS Time To Data Transfer | |
| 172 | (Spare/Reserved) | - |
| 173 | BSS Container | |
| 174 | Cell Identification | |
| 175 | PDU Numbers | |
| 176 | BSS GP Cause | |
| 177 | Required MBMS Bearer Capabilities | |
| 178 | RIM Routing Address Discriminator | |
| 179 | List of Setup PFCs | |
| 180 | PS Handover XID Parameters | |
| 181 | MS Info Change Reporting Action | |
| 182 | Direct Tunnel Flags | |
| 183 | Correlation Id | |
| 184 | Bearer Control Mode | |
| 185 | MBMS Flow Identifier | |
| 186 | MBMS IP Multicast Distribution | |
| 187 | MBMS Distribution Acknowledgement | |
| 188 | Reliable InterRAT Handover Info | |
| 189 | RFSP Index | |
| 190 | Fully Qualified Domain Name | |
| 191 | Evolved Allocation Retention Priority I | |
| 192 | Evolved Allocation Retention Priority II | |
| 193 | Extended Common Flags | Yes |
| 194 | User CSG Information | |
| 195 | CSG Information Reporting Action | |
| 196 | CSG ID | |
| 197 | CSG Membership Indication | |
| 198 | Aggregate Maximum Bit Rate | |
| 199 | UE Network Capability | |
| 200 | UE-AMBR | |
| 201 | APN-AMBR with NSAPI | |
| 202 | GGSN Back-Off Time | |
| 203 | Signalling Priority Indication | |
| 204 | Signalling Priority Indication with NSAPI | |
| 205 | Higher Bitrates than 16Mbps Flag | |
| 206 | (Spare/Reserved) | - |
| 207 | Additional MM Context for SRVCC | |
| 208 | Additional Flags for SRVCC | |
| 209 | STN-SR | |
| 210 | C-MSISDN | |
| 211 | Extended RANAP Cause | |
| 212 | eNodeB ID | |
| 213 | Selection Mode with NSAPI | |
| 214 | ULI Timestamp | Yes |
| 215 | LHN Id with NSAPI | |
| 216 | CN Operator Selection Entity | |
| 217 | UE Usage Type | |
| 218 | Extended Common Flags II | Yes |
| 219 | Node Identifier | |
| 220 | CIoT Optimizations Support Indication | |
| 221 | SCEF PDN Connection | |
| 222 | IOV Updates Counter | |
| 223-237 | (Spare/Reserved) | - |
| 238 | Special IE Type for IE Type Extension | |
| 239-250 | (Spare/Reserved) | - |
| 251 | Charging Gateway Address | |
| 252-254 | (Spare/Reserved) | - |
| 255 | Private Extension |
Documentation
¶
Overview ¶
Package gtpv1 provides simple and painless handling of GTPv1-C and GTPv1-U protocol in pure Golang.
Please see README.md for detailed usage of the APIs provided by this package.
Index ¶
- Constants
- Variables
- func Decapsulate(b []byte) (uint32, []byte, error)
- func DecapsulateWithExtensionHeader(b []byte) (uint32, []byte, []*message.ExtensionHeader, error)
- func DisableLogging()
- func EnableLogging(l *log.Logger)
- func Encapsulate(teid uint32, payload []byte) *message.TPDU
- func EncapsulateWithExtensionHeader(teid uint32, payload []byte, extHdrs ...*message.ExtensionHeader) *message.TPDU
- func SetLogger(l *log.Logger)
- type Conn
- type ErrorIndicatedError
- type HandlerFunc
- type HandlerNotFoundError
- type KernelGTP
- type Relaydeprecated
- func (r *Relay) AddPeer(teidIn, teidOut uint32, raddr net.Addr)deprecated
- func (r *Relay) Close() errordeprecated
- func (r *Relay) Run()deprecated
- type Role
- type UPlaneConn
- func (u *UPlaneConn) AddHandler(msgType uint8, fn HandlerFunc)
- func (u *UPlaneConn) AddHandlers(funcs map[uint8]HandlerFunc)
- func (u *UPlaneConn) AddTunnel(peerIP, msIP net.IP, otei, itei uint32) error
- func (u *UPlaneConn) AddTunnelOverride(peerIP, msIP net.IP, otei, itei uint32) error
- func (u *UPlaneConn) Close() error
- func (u *UPlaneConn) CloseRelay(teidIn uint32) error
- func (u *UPlaneConn) DelTunnelByITEI(itei uint32) error
- func (u *UPlaneConn) DelTunnelByMSAddress(msIP net.IP) error
- func (u *UPlaneConn) DisableErrorIndication()
- func (u *UPlaneConn) EchoRequest(raddr net.Addr) error
- func (u *UPlaneConn) EchoResponse(raddr net.Addr) error
- func (u *UPlaneConn) EnableErrorIndication()
- func (u *UPlaneConn) EnableKernelGTP(devname string, role Role) error
- func (u *UPlaneConn) ErrorIndication(raddr net.Addr, received message.Message) error
- func (u *UPlaneConn) ListenAndServe(ctx context.Context) error
- func (u *UPlaneConn) LocalAddr() net.Addr
- func (u *UPlaneConn) NewFTEID(ifType uint8, v4, v6 string) (fteidIE *v2ie.IE)
- func (u *UPlaneConn) ReadFrom(p []byte) (n int, addr net.Addr, err error)
- func (u *UPlaneConn) ReadFromGTP(p []byte) (n int, addr net.Addr, teid uint32, err error)
- func (u *UPlaneConn) RelayTo(c *UPlaneConn, teidIn, teidOut uint32, raddr net.Addr) error
- func (u *UPlaneConn) RespondTo(raddr net.Addr, received, toBeSent message.Message) error
- func (u *UPlaneConn) Restarts() uint8
- func (u *UPlaneConn) SetDeadline(t time.Time) error
- func (u *UPlaneConn) SetReadDeadline(t time.Time) error
- func (u *UPlaneConn) SetWriteDeadline(t time.Time) error
- func (u *UPlaneConn) WriteTo(p []byte, addr net.Addr) (n int, err error)
- func (u *UPlaneConn) WriteToGTP(teid uint32, p []byte, addr net.Addr) (n int, err error)
- func (u *UPlaneConn) WriteToWithDSCPECN(p []byte, addr net.Addr, dscpecn int) (n int, err error)
Constants ¶
const ( GTPCPort = ":2123" GTPUPort = ":2152" )
Registered UDP ports
const ( ReqCauseRequestIMSI uint8 = iota ReqCauseRequestIMEI ReqCauseRequestIMSIAndIMEI ReqCauseNoIdentityNeeded ReqCauseMSRefuses ReqCauseMSIsNotGPRSResponding ReqCauseReactivationRequested ReqCausePDPAddressInactivityTimerExpires ReqCauseNetworkFailure ReqCauseQoSParameterMismatch )
Cause definitions.
const ( ResCauseRequestAccepted uint8 = iota + 128 ResCauseNewPDPTypeDueToNetworkPreference ResCauseNewPDPTypeDueToSingleAddressBearerOnly )
Cause definitions.
const ( ResCauseNonExistent uint8 = iota + 192 ResCauseInvalidMessageFormat ResCauseIMSIIMEINotKnown ResCauseMSIsGPRSDetached ResCauseMSIsNotGPRSResponding ResCauseMSRefuses ResCauseVersionNotSupported ResCauseNoResourcesAvailable ResCauseServiceNotSupported ResCauseMandatoryIEIncorrect ResCauseMandatoryIEMissing ResCauseOptionalIEIncorrect ResCauseSystemFailure ResCauseRoamingRestriction ResCausePTMSISignatureMismatch ResCauseGPRSConnectionSuspended ResCauseAuthenticationFailure ResCauseUserAuthenticationFailed ResCauseContextNotFound ResCauseAllDynamicPDPAddressesAreOccupied ResCauseNoMemoryIsAvailable ResCauseRelocationFailure ResCauseUnknownMandatoryExtensionHeader ResCauseSemanticErrorInTheTFTOperation ResCauseSyntacticErrorInTheTFTOperation ResCauseSemanticErrorsInPacketFilter ResCauseSyntacticErrorsInPacketFilter ResCauseMissingOrUnknownAPN ResCauseUnknownPDPAddressOrPDPType ResCausePDPContextWithoutTFTAlreadyActivated ResCauseAPNAccessDeniedNoSubscription ResCauseAPNRestrictionTypeIncompatibilityWithCurrentlyActivePDPContexts ResCauseMSMBMSCapabilitiesInsufficient ResCauseInvalidCorrelationID ResCauseMBMSBearerContextSuperseded ResCauseBearerControlModeViolation ResCauseCollisionWithNetworkInitiatedRequest ResCauseAPNCongestion ResCauseBearerHandlingNotSupported ResCauseTargetAccessRestrictedForTheSubscriber ResCauseUEIsTemporarilyNotReachableDueToPowerSaving ResCauseRelocationFailureDueToNASMessageRedirection )
Cause definitions.
const ( SelectionModeMSorNetworkProvidedAPNSubscribedVerified uint8 = iota | 0xf0 SelectionModeMSProvidedAPNSubscriptionNotVerified SelectionModeNetworkProvidedAPNSubscriptionNotVerified )
SelectionMode definitions.
const ( PDPTypeETSI uint8 = iota | 0xf0 PDPTypeIETF )
PDP Type Organization definitions.
const ( ProtoIDLCP uint16 = 0xc021 ProtoIDPAP uint16 = 0xc023 ProtoIDCHAP uint16 = 0xc223 ProtoIDIPCP uint16 = 0x8021 )
Protocol ID definitions. For more identifiers, see RFC 3232.
const ( ContIDPCSCFIPv6AddressRequest uint16 ContIDIMCNSubsystemSignalingFlag ContIDDNSServerIPv6AddressRequest ContIDNotSupported ContIDMSSupportofNetworkRequestedBearerControlIndicator ContIDDSMIPv6HomeAgentAddressRequest ContIDDSMIPv6HomeNetworkPrefixRequest ContIDDSMIPv6IPv4HomeAgentAddressRequest ContIDIPaddressAllocationViaNASSignalling ContIDIPv4addressAllocationViaDHCPv4 ContIDPCSCFIPv4AddressRequest ContIDDNSServerIPv4AddressRequest ContIDMSISDNRequest ContIDIFOMSupportRequest ContIDIPv4LinkMTURequest ContIDMSSupportOfLocalAddressInTFTIndicator ContIDPCSCFReselectionSupport ContIDNBIFOMRequestIndicator ContIDNBIFOMMode ContIDNonIPLinkMTURequest ContIDAPNRateControlSupportIndicator ContID3GPPPSDataOffUEStatus ContIDReliableDataServiceRequestIndicator ContIDAdditionalAPNRateControlForExceptionDataSupportIndicator ContIDPDUSessionID ContIDEthernetFramePayloadMTURequest ContIDUnstructuredLinkMTURequest ContID5GSMCauseValue )
Container ID definitions.
const ( RatTypeUTRAN uint8 RatTypeGERAN RatTypeWLAN RatTypeGAN RatTypeHSPAEvolution RatTypeEUTRAN )
RATType definitions.
const ( LocTypeCGI uint8 = iota LocTypeSAI LocTypeRAI )
UserLocationInformation GeographicLocationType definitions.
const ( APNRestrictionNoExistingContextsorRestriction uint8 = iota APNRestrictionPublic1 APNRestrictionPublic2 APNRestrictionPrivate1 APNRestrictionPrivate2 )
APN Restriction definitions.
const ( MAPCauseUnknownSubscriber uint8 MAPCauseUnknownBaseStation MAPCauseUnknownMSC MAPCauseSecureTransportError MAPCauseUnidentifiedSubscriber MAPCauseAbsentSubscriberSM MAPCauseUnknownEquipment MAPCauseRoamingNotAllowed MAPCauseIllegalSubscriber MAPCauseBearerServiceNotProvisioned MAPCauseTeleserviceNotProvisioned MAPCauseIllegalEquipment MAPCauseCallBarred MAPCauseForwardingViolation MAPCauseCUGReject MAPCauseIllegalSSOperation MAPCauseSSErrorStatus MAPCauseSSNotAvailable MAPCauseSSSubscriptionViolatio MAPCauseSSIncompatibility MAPCauseFacilityNotSupported MAPCauseOngoingGroupCall MAPCauseInvalidTargetBaseStation MAPCauseNoRadioResourceAvailable MAPCauseNoHandoverNumberAvailable MAPCauseSubsequentHandoverFailure MAPCauseAbsentSubscriber MAPCauseIncompatibleTerminal MAPCauseShortTermDenial MAPCauseLongTermDenial MAPCauseSubscriberBusyForMTSMS MAPCauseSMDeliveryFailure MAPCauseMessageWaitingListFull MAPCauseSystemFailure MAPCauseDataMissing MAPCauseUnexpectedDataValue MAPCausePWRegistrationFailure MAPCauseNegativePWCheck MAPCauseNoRoamingNumberAvailable MAPCauseTracingBufferFull MAPCauseTargetCellOutsideGroupCallArea MAPCauseNumberOfPWAttemptsViolation MAPCauseNumberChanged MAPCauseBusySubscriber MAPCauseNoSubscriberReply MAPCauseForwardingFailed MAPCauseORNotAllowed MAPCauseATINotAllowed MAPCauseNoGroupCallNumberAvailable MAPCauseResourceLimitation MAPCausePositionMethodFailure MAPCauseUnknownOrUnreachableLCSClient MAPCauseMMEventNotSupported MAPCauseATSINotAllowed MAPCauseATMNotAllowed MAPCauseInformationNotAvailabl MAPCauseUnknownAlphabe MAPCauseUSSDBusy )
MAP Cause definitions.
const ( RABPreempted uint8 RANAPCauseTrelocoverallExpiry RANAPCauseTrelocprepExpiry RANAPCauseTreloccompleteExpiry RANAPCauseTqueuingExpiry RANAPCauseRelocationTriggered RANAPCauseTRELOCallocExpiry RANAPCauseUnableToEstablishDuringRelocation RANAPCauseUnknownTargetRNC RANAPCauseRelocationCancelled RANAPCauseSuccessfulRelocation RANAPCauseRequestedCipheringIntegrityProtectionAlgorithmsNotSupported RANAPCauseChangeOfCipheringIntegrityProtectionIsNotSupported RANAPCauseFailureInTheRadioInterfaceProcedure RANAPCauseReleaseDueToUTRANGeneratedReason RANAPCauseUserInactivity RANAPCauseTimeCriticalRelocation RANAPCauseRequestedTrafficClassNotAvailable RANAPCauseInvalidRABParametersValue RANAPCauseRequestedMaximumBitRateNotAvailable RANAPCauseRequestedGuaranteedBitRateNotAvailable RANAPCauseRequestedTransferDelayNotAchievable RANAPCauseInvalidRABParametersCombination RANAPCauseConditionViolationForSDUParameters RANAPCauseConditionViolationForTrafficHandlingPriority RANAPCauseConditionViolationForGuaranteedBitRate RANAPCauseUserPlaneVersionsNotSupported RANAPCauseIuUPFailure RANAPCauseRelocationFailureInTargetCNRNCOrTargetSystem RANAPCauseInvalidRABID RANAPCauseNoRemainingRAB RANAPCauseInteractionWithOtherProcedure RANAPCauseRequestedMaximumBitRateForDLNotAvailable RANAPCauseRequestedMaximumBitRateForULNotAvailable RANAPCauseRequestedGuaranteedBitRateForDLNotAvailable RANAPCauseRequestedGuaranteedBitRateForULNotAvailable RANAPCauseRepeatedIntegrityCheckingFailure RANAPCauseRequestedReportTypeNotSupported RANAPCauseRequestSuperseded RANAPCauseReleaseDueToUEWenRatedSignallingConnectionRelease RANAPCauseResourceOptimisationRelocation RANAPCauseRequestedInformationNotAvailable RANAPCauseRelocationDesirableForRadioReasons RANAPCauseRelocationNotSupportedInTargetRNCOrTargetSystem RANAPCauseDirectedRetry RANAPCauseRadioConnectionWithUELost RANAPCauseRNCUnableToEstablishAllRFCs RANAPCauseDecipheringKeysNotAvailable RANAPCauseDedicatedAssistanceDataNotAvailable RANAPCauseRelocationTargetNotAllowed RANAPCauseLocationReportingCongestion RANAPCauseReduceLoadInServingCell RANAPCauseNoRadioResourcesAvailableInTargetCell RANAPCauseGERANIuModeFailure RANAPCauseIncomingRelocationNotSupportedDueTodPUESBINEFeature RANAPCauseTrafficLoadInTheTargetCellHigherThanInTheSourceCell RANAPCauseMBMSNoMulticastServiceForThisUE RANAPCauseMBMSUnknownUEID RANAPCauseSuccessfulMBMSSessionStartNoDataBearerNecessary RANAPCauseMBMSSupersededDueToNNSF RANAPCauseMBMSUELinkingAlreadyDone RANAPCauseMBMSUEDeLinkingFailureNoExistingUELinking RANAPCauseTMGIUnknown RANAPCauseSignallingTransportResourceFailure RANAPCauseIuTransportConnectionFailedToEstablish RANAPCauseUserRestrictionStartIndication RANAPCauseUserRestrictionEndIndication RANAPCauseNormalRelease RANAPCauseTransferSyntaxError RANAPCauseSemanticError RANAPCauseMessageNotCompatibleWithReceiverState RANAPCauseAbstractSyntaxErrorReject RANAPCauseAbstractSyntaxErrorIgnoreAndNotify RANAPCauseAbstractSyntaxErrorFalselyConstructedMessage RANAPCauseOAMIntervention RANAPCauseNoResourceAvailable RANAPCauseUnspecifiedFailure RANAPCauseNetworkOptimisation )
RANAP Cause definitions.
const (
ConfigProtocolPPPWithIP uint8 = 0
)
Configuration Protocol definitions.
Variables ¶
var ( // ErrUnexpectedType indicates that the type of incoming message is not expected. ErrUnexpectedType = errors.New("got unexpected type of message") // ErrInvalidConnection indicates that the connection type(C-Plane or U-Plane) is // not the expected one. ErrInvalidConnection = errors.New("got invalid connection type") // ErrConnNotOpened indicates that some operation is failed due to the status of // Conn is not valid. ErrConnNotOpened = errors.New("connection is not opened") )
Functions ¶
func Decapsulate ¶
Decapsulate decapsulates given bytes and returns TEID and Payload.
func DecapsulateWithExtensionHeader ¶ added in v0.8.8
DecapsulateWithExtensionHeader decapsulates given bytes and returns TEID, Payload, and Extension Headers. It is always safe to use this even if there may be no Extension Headers.
func DisableLogging ¶
func DisableLogging()
DisableLogging disables the logging from the package. Logging is enabled by default.
func EnableLogging ¶
EnableLogging enables the logging from the package. If l is nil, it uses default logger provided by the package. Logging is enabled by default.
See also: SetLogger.
func Encapsulate ¶
Encapsulate encapsulates given payload with GTPv1-U Header and returns message.TPDU.
func EncapsulateWithExtensionHeader ¶ added in v0.8.8
func EncapsulateWithExtensionHeader(teid uint32, payload []byte, extHdrs ...*message.ExtensionHeader) *message.TPDU
EncapsulateWithExtensionHeader encapsulates given payload and Extension Headers with GTPv1-U Header and returns message.TPDU.
func SetLogger ¶
SetLogger replaces the standard logger with arbitrary *log.Logger.
This package prints just informational logs from goroutines working background that might help developers test the program but can be ignored safely. More important ones that needs any action by caller would be returned as errors.
Types ¶
type Conn ¶
type Conn interface {
net.PacketConn
AddHandler(uint8, HandlerFunc)
RespondTo(net.Addr, message.Message, message.Message) error
Restarts() uint8
}
Conn is an abstraction of both GTPv1-C and GTPv1-U Conn.
type ErrorIndicatedError ¶
ErrorIndicatedError indicates that Error Indication message is received on U-Plane Connection.
func (*ErrorIndicatedError) Error ¶
func (e *ErrorIndicatedError) Error() string
type HandlerFunc ¶
HandlerFunc is a handler for specific GTPv1 message.
type HandlerNotFoundError ¶ added in v0.7.11
type HandlerNotFoundError struct {
MsgType string
}
HandlerNotFoundError indicates that the handler func is not registered in *Conn for the incoming GTPv2 message. In usual cases this error should not be taken as fatal, as the other endpoint can make your program stop working just by sending unregistered message.
func (*HandlerNotFoundError) Error ¶ added in v0.7.11
func (e *HandlerNotFoundError) Error() string
Error returns violating message type to handle.
type Relay
deprecated
type Relay struct {
// contains filtered or unexported fields
}
Relay is to relay packets between two UPlaneConn.
Deprecated: Use UPlaneConn.RelayTo() instead.
func NewRelay
deprecated
func NewRelay(leftConn, rightConn *UPlaneConn) *Relay
NewRelay creates a new Relay.
Deprecated: Use UPlaneConn.RelayTo() instead.
type UPlaneConn ¶
type UPlaneConn struct {
// for Linux kernel GTP with netlink
KernelGTP
// contains filtered or unexported fields
}
UPlaneConn represents a U-Plane Connection of GTPv1.
func DialUPlane ¶
DialUPlane sends Echo Request to raddr to check if the endpoint is alive and returns UPlaneConn.
func NewUPlaneConn ¶
func NewUPlaneConn(laddr net.Addr) *UPlaneConn
NewUPlaneConn creates a new UPlaneConn used for server. On client side, use DialUPlane instead.
func (*UPlaneConn) AddHandler ¶
func (u *UPlaneConn) AddHandler(msgType uint8, fn HandlerFunc)
AddHandler adds a message handler to *UPlaneConn.
By adding HandlerFuncs, *UPlaneConn (and *Session, *Bearer created by the *UPlaneConn) will handle the specified type of message with it's paired HandlerFunc when receiving. Messages without registered handlers are just ignored and discarded and the user will get ErrNoHandlersFound error.
This should be performed just after creating *UPlaneConn, otherwise the user cannot retrieve any values, which is in most cases vital to continue working as a node, from the incoming message.
HandlerFuncs for EchoResponse and ErrorIndication are registered by default. These HandlerFuncs can be overwritten by specifying message.MsgTypeEchoResponse and/or message.MsgTypeErrorIndication as msgType parameter.
func (*UPlaneConn) AddHandlers ¶
func (u *UPlaneConn) AddHandlers(funcs map[uint8]HandlerFunc)
AddHandlers adds multiple handler funcs at a time.
See AddHandler for detailed usage.
func (*UPlaneConn) AddTunnel ¶
func (u *UPlaneConn) AddTunnel(peerIP, msIP net.IP, otei, itei uint32) error
AddTunnel adds a GTP-U tunnel with Linux Kernel GTP-U via netlink.
func (*UPlaneConn) AddTunnelOverride ¶
func (u *UPlaneConn) AddTunnelOverride(peerIP, msIP net.IP, otei, itei uint32) error
AddTunnelOverride adds a GTP-U tunnel with Linux Kernel GTP-U via netlink. If there is already an existing tunnel that has the same msIP and/or incoming TEID, this deletes it before adding the tunnel.
func (*UPlaneConn) Close ¶
func (u *UPlaneConn) Close() error
Close closes the connection. Any blocked Read or Write operations will be unblocked and return errors.
func (*UPlaneConn) CloseRelay ¶
func (u *UPlaneConn) CloseRelay(teidIn uint32) error
CloseRelay stops relaying T-PDU from a conn to conn.
func (*UPlaneConn) DelTunnelByITEI ¶
func (u *UPlaneConn) DelTunnelByITEI(itei uint32) error
DelTunnelByITEI deletes a Linux Kernel GTP-U tunnel specified with the incoming TEID.
func (*UPlaneConn) DelTunnelByMSAddress ¶
func (u *UPlaneConn) DelTunnelByMSAddress(msIP net.IP) error
DelTunnelByMSAddress deletes a Linux Kernel GTP-U tunnel specified with the subscriber's IP.
func (*UPlaneConn) DisableErrorIndication ¶ added in v0.7.7
func (u *UPlaneConn) DisableErrorIndication()
DisableErrorIndication makes default T-PDU handler stop responding with Error Indication in case of receiving T-PDU with unknown TEID.
When disabled, it passes the unhandled T-PDU to user who calls ReadFromGTP instead.
func (*UPlaneConn) EchoRequest ¶
func (u *UPlaneConn) EchoRequest(raddr net.Addr) error
EchoRequest sends a EchoRequest.
func (*UPlaneConn) EchoResponse ¶
func (u *UPlaneConn) EchoResponse(raddr net.Addr) error
EchoResponse sends a EchoResponse.
func (*UPlaneConn) EnableErrorIndication ¶ added in v0.7.7
func (u *UPlaneConn) EnableErrorIndication()
EnableErrorIndication re-enables automatic sending of Error Indication to unknown messages, which is enabled by default.
See also: DisableErrorIndication.
func (*UPlaneConn) EnableKernelGTP ¶
func (u *UPlaneConn) EnableKernelGTP(devname string, role Role) error
EnableKernelGTP enables Linux Kernel GTP-U. Note that this removes all the existing userland tunnels, and cannot be disabled while the program is working (at least at this moment).
Using Kernel GTP-U is much more performant than userland, but requires root privilege. After enabled, users should add tunnels by AddTunnel func, and also add appropriate routing entries. For handling downlink traffic on P-GW, for example;
ip route add <UE's IP> dev <devname> table <table ID> ip rule add from <SGi side of I/F> lookup <table ID>
This let the traffic from SGi side of network I/F to be forwarded to GTP device, and if the UE's IP is known to Kernel GTP-U(by AddTunnel), it is encapsulated and forwarded to the peer(S-GW, in this case).
Please see the examples/gw-tester for how each node handles routing from the program.
func (*UPlaneConn) ErrorIndication ¶
ErrorIndication just sends ErrorIndication message.
func (*UPlaneConn) ListenAndServe ¶
func (u *UPlaneConn) ListenAndServe(ctx context.Context) error
ListenAndServe creates a new GTPv2-C *Conn and start serving. This blocks, and returns error only if it face the fatal one. Non-fatal errors are logged with logger. See SetLogger/EnableLogger/DisableLogger for handling of those logs.
func (*UPlaneConn) LocalAddr ¶
func (u *UPlaneConn) LocalAddr() net.Addr
LocalAddr returns the local network address.
func (*UPlaneConn) NewFTEID ¶
func (u *UPlaneConn) NewFTEID(ifType uint8, v4, v6 string) (fteidIE *v2ie.IE)
NewFTEID creates a new GTPv2 F-TEID with random TEID value that is unique within UPlaneConn. To ensure the uniqueness, don't create in the other way if you once use this method. This is meant to be used for creating F-TEID IE for non-local interface type, such as the ones that are used in U-Plane. For local interface, use (*Conn).NewSenderFTEID instead.
Note that in the case there's a lot of Session on the Conn, it may take a long time to find a new unique value.
TODO: optimize performance...
func (*UPlaneConn) ReadFrom ¶
ReadFrom reads a packet from the connection, copying the payload into p. It returns the number of bytes copied into p and the return address that was on the packet. It returns the number of bytes read (0 <= n <= len(p)) and any error encountered. Callers should always process the n > 0 bytes returned before considering the error err. ReadFrom can be made to time out and return an Error with Timeout() == true after a fixed time limit; see SetDeadline and SetReadDeadline.
Note that valid GTP-U packets handled by Kernel can NOT be retrieved by this.
func (*UPlaneConn) ReadFromGTP ¶
ReadFromGTP reads a packet from the connection, copying the payload without GTP header into p. It returns the number of bytes copied into p, the return address that was on the packet, TEID in the GTP header.
Note that valid GTP-U packets handled by Kernel can NOT be retrieved by this.
func (*UPlaneConn) RelayTo ¶
func (u *UPlaneConn) RelayTo(c *UPlaneConn, teidIn, teidOut uint32, raddr net.Addr) error
RelayTo relays T-PDU type of packet to peer node(specified by raddr) from the UPlaneConn given.
By using this, owner of UPlaneConn won't be able to Read and Write the packets that has teidIn.
func (*UPlaneConn) RespondTo ¶
RespondTo sends a message(specified with "toBeSent" param) in response to a message(specified with "received" param).
This is to make it easier to handle SequenceNumber.
func (*UPlaneConn) Restarts ¶
func (u *UPlaneConn) Restarts() uint8
Restarts returns the number of restarts in uint8.
func (*UPlaneConn) SetDeadline ¶
func (u *UPlaneConn) SetDeadline(t time.Time) error
SetDeadline sets the read and write deadlines associated with the connection. It is equivalent to calling both SetReadDeadline and SetWriteDeadline.
A deadline is an absolute time after which I/O operations fail with a timeout (see type Error) instead of blocking. The deadline applies to all future and pending I/O, not just the immediately following call to Read or Write. After a deadline has been exceeded, the connection can be refreshed by setting a deadline in the future.
An idle timeout can be implemented by repeatedly extending the deadline after successful Read or Write calls.
A zero value for t means I/O operations will not time out.
func (*UPlaneConn) SetReadDeadline ¶
func (u *UPlaneConn) SetReadDeadline(t time.Time) error
SetReadDeadline sets the deadline for future Read calls and any currently-blocked Read call. A zero value for t means Read will not time out.
func (*UPlaneConn) SetWriteDeadline ¶
func (u *UPlaneConn) SetWriteDeadline(t time.Time) error
SetWriteDeadline sets the deadline for future Write calls and any currently-blocked Write call. Even if write times out, it may return n > 0, indicating that some of the data was successfully written. A zero value for t means Write will not time out.
func (*UPlaneConn) WriteTo ¶
WriteTo writes a packet with payload p to addr. WriteTo can be made to time out and return an Error with Timeout() == true after a fixed time limit; see SetDeadline and SetWriteDeadline. On packet-oriented connections, write timeouts are rare.
func (*UPlaneConn) WriteToGTP ¶
WriteToGTP writes a packet with TEID and payload to addr.
func (*UPlaneConn) WriteToWithDSCPECN ¶ added in v0.8.2
WriteToWithDSCPECN writes a packet with payload p to addr using the given DSCP/ECN value. WriteToWithDSCPECN can be made to time out and return an Error with Timeout() == true after a fixed time limit; see SetDeadline and SetWriteDeadline. On packet-oriented connections, write timeouts are rare.
Source Files
¶
Directories
¶
| Path | Synopsis |
|---|---|
|
Package ie provides encoding/decoding feature of GTPv1 Information Elements.
|
Package ie provides encoding/decoding feature of GTPv1 Information Elements. |
|
Package message provides encoding/decoding feature of GTPv1 protocol.
|
Package message provides encoding/decoding feature of GTPv1 protocol. |
|
Package testutils is an internal package to be used for unit tests.
|
Package testutils is an internal package to be used for unit tests. |