GTP-U: complete rework of the Extension Headers
This commit is contained in:
p1-bmu
parent
5d42082fba
commit
11c791572c
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@ -1,7 +1,7 @@
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# -*- coding: UTF-8 -*-
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#/**
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# * Software Name : pycrate
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# * Version : 0.4
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# * Version : 0.5
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# *
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# * Copyright 2019. Benoit Michau. P1Sec.
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# *
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@ -27,25 +27,15 @@
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# *--------------------------------------------------------
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#*/
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'''
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__all__ = [
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# GTPU extension headers
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'GTPUHdrExtAuto',
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'GTPUHdrExt3',
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'GTPUHdrExt32',
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'GTPUHdrExt64',
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'GTPUHdrExt129',
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'GTPUHdrExt131',
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'GTPUHdrExt132',
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'GTPUHdrExt133',
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'GTPUHdrExt192',
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# GTPU Messages
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'GTPUMsg',
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'GTPUEchoRequest',
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'GTPUEchoResponse',
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'GTPUErrorInd',
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'GTPUSuppExtHdrNotif',
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'GTPUEndMarker',
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'GTPUTunnelStatus',
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'GPDU',
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# GTPU Message parser and associated errors
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'parse_GTPU',
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@ -53,7 +43,7 @@ __all__ = [
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'ERR_GTPU_BUF_INVALID',
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'ERR_GTPU_TYPE_NONEXIST'
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]
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'''
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#------------------------------------------------------------------------------#
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# 3GPP TS 29.281: General Packet Radio System (GPRS) Tunnelling Protocol
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@ -74,12 +64,12 @@ from pycrate_core.base import *
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#------------------------------------------------------------------------------#
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GTPUNextExtHeader_dict = {
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0 : 'No more extension headers',
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1 : 'Reserved - Control Plane only',
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2 : 'Reserved - Control Plane only',
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3 : 'Long PDCP PDU Number',
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32 : 'Service Class Indicator',
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64 : 'UDP source port of the triggering message',
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0 : 'No more extension headers',
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1 : 'Reserved - Control Plane only',
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2 : 'Reserved - Control Plane only',
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3 : 'Long PDCP PDU Number',
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32 : 'Service Class Indicator',
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64 : 'UDP source port of the triggering message',
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129 : 'RAN Container',
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130 : 'Long PDCP PDU Number',
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131 : 'Xw RAN Container',
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@ -90,28 +80,10 @@ GTPUNextExtHeader_dict = {
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194 : 'Reserved - Control Plane only'
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}
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# non-automated base class
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class GTPUHdrExt(Envelope):
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_ID = 0xff
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_GEN = (
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Uint8('Len'),
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Buf('Content'),
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Uint8('NextExt', dic=GTPUNextExtHeader_dict)
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)
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def __init__(self, *args, **kwargs):
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Envelope.__init__(self, *args, **kwargs)
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self[-1].set_valauto(lambda: self._get_next_hdr())
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def _get_next_hdr(self):
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n = self.get_next()
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if n and hasattr(n, '_ID'):
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return n._ID
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else:
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return 0
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# buffer that makes the Ext Header 32-bit-aligned
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class BufAligned(Buf):
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PAD = b'\0'
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def set_val(self, val):
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@ -122,135 +94,107 @@ class BufAligned(Buf):
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Buf.set_val(self, val)
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# automated base class
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class GTPUHdrExtAuto(GTPUHdrExt):
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_ID = 0xff
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# prototype for the content of a generic Ext Header
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class _GTPUHdrExtCont(Envelope):
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_GEN = (
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BufAligned('Value', val=b'\0\0', rep=REPR_HEX),
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)
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_ID = 1
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def __init__(self, *args, **kwargs):
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if 'ID' in kwargs:
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self._ID = kwargs['ID']
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del kwargs['ID']
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Envelope.__init__(self, *args, **kwargs)
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def clone(self):
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c = Envelope.clone(self)
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c._ID = self._ID
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return c
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class _LongPDCPPDUNumber(_GTPUHdrExtCont):
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_GEN = (
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Uint('spare', bl=6, rep=REPR_HEX),
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Uint('Value', bl=18),
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Uint24('spare', rep=REPR_HEX),
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)
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# All defined Ext Header
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GTPUHdrExtCont_dict = {
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3 : _LongPDCPPDUNumber('LongPDCPPDUNumber',
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ID=3),
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32 : _GTPUHdrExtCont('ServiceClassInd', GEN=(
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Uint8('Value'),
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Uint8('spare', rep=REPR_HEX),
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), ID=32),
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64 : _GTPUHdrExtCont('UDPPort', GEN=(
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Uint16('Value'),
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), ID=64),
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129 : _GTPUHdrExtCont('RANContainer',
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ID=129),
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130 : _LongPDCPPDUNumber('LongPDCPPDUNumber',
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ID=130),
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131 : _GTPUHdrExtCont('XwRANContainer',
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ID=131),
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132 : _GTPUHdrExtCont('NRRANContainer',
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D=132),
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133 : _GTPUHdrExtCont('PDUSessionContainer',
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ID=133),
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192 : _GTPUHdrExtCont('PDCPPDUNumber', GEN=(
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Uint('Value', bl=15),
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Uint('spare', bl=1, rep=REPR_HEX),
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), ID=192)
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}
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class GTPUHdrExt(Envelope):
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_GEN = (
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Uint8('Len'),
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BufAligned('Content', rep=REPR_HEX),
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_GTPUHdrExtCont('Content', rep=REPR_HEX),
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Uint8('NextExt', dic=GTPUNextExtHeader_dict)
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)
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def __init__(self, *args, **kwargs):
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GTPUHdrExt.__init__(self, *args, **kwargs)
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Envelope.__init__(self, *args, **kwargs)
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self[0].set_valauto(lambda: (2 + self[1].get_len()) >> 2)
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self[1].set_blauto(lambda: max(0, (self[0].get_val()*32) - 16))
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#------------------------------------------------------------------------------#
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# UDP Port
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# TS 29.281, section 5.2.2.1
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#------------------------------------------------------------------------------#
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class GTPUHdrExt64(GTPUHdrExt):
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_ID = 64
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_GEN = (
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Uint8('Len', val=1),
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Uint16('UDPPort'),
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Uint8('NextExt')
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)
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#------------------------------------------------------------------------------#
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# PDCP PDU Number
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# TS 29.281, section 5.2.2.2
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#------------------------------------------------------------------------------#
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class GTPUHdrExt192(GTPUHdrExt):
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_ID = 192
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_GEN = (
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Uint8('Len', val=1),
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Uint('PDCPPDUNumber', bl=15),
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Uint('spare', bl=1, rep=REPR_HEX),
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Uint8('NextExt')
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)
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#------------------------------------------------------------------------------#
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# Long PDCP PDU Number
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# TS 29.281, section 5.2.2.2A
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#------------------------------------------------------------------------------#
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class GTPUHdrExt3(GTPUHdrExt):
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_ID = 3
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_GEN = (
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Uint8('Len', val=2),
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Uint('spare', bl=6, rep=REPR_HEX),
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Uint('LongPDCPPDUNumber', bl=18),
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Uint24('spare', rep=REPR_HEX),
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Uint8('NextExt')
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)
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#------------------------------------------------------------------------------#
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# Service Class Indicator
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# TS 29.281, section 5.2.2.3
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#------------------------------------------------------------------------------#
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class GTPUHdrExt32(GTPUHdrExt):
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_ID = 32
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_GEN = (
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Uint8('Len', val=1),
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Uint8('ServiceClassInd'),
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Uint8('spare', rep=REPR_HEX),
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Uint8('NextExt')
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)
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#------------------------------------------------------------------------------#
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# RAN Container
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# TS 29.281, section 5.2.2.4
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#------------------------------------------------------------------------------#
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class GTPUHdrExt129(GTPUHdrExtAuto):
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_ID = 129
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_GEN = (
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Uint8('Len'),
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BufAligned('RANContainer', rep=REPR_HEX),
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Uint8('NextExt')
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)
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#------------------------------------------------------------------------------#
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# Xw RAN Container
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# TS 29.281, section 5.2.2.5
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#------------------------------------------------------------------------------#
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class GTPUHdrExt131(GTPUHdrExtAuto):
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_ID = 131
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_GEN = (
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Uint8('Len'),
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BufAligned('XwRANContainer', rep=REPR_HEX),
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Uint8('NextExt')
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)
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#------------------------------------------------------------------------------#
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# NR RAN Container
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# TS 29.281, section 5.2.2.6
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#------------------------------------------------------------------------------#
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class GTPUHdrExt132(GTPUHdrExtAuto):
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_ID = 132
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_GEN = (
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Uint8('Len'),
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BufAligned('NRRANContainer', rep=REPR_HEX),
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Uint8('NextExt')
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)
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#------------------------------------------------------------------------------#
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# PDU Session Container
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# TS 29.281, section 5.2.2.7
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#------------------------------------------------------------------------------#
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class GTPUHdrExt133(GTPUHdrExtAuto):
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_ID = 133
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_GEN = (
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Uint8('Len'),
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BufAligned('PDUSessionContainer', rep=REPR_HEX),
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Uint8('NextExt')
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)
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self[1].set_blauto(lambda: self._get_cont_len())
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self[2].set_valauto(lambda: self._get_ne())
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def _get_cont_len(self):
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return max(0, (self[0].get_val()*32) - 16)
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def _get_ne(self):
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n = self.get_next()
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if n:
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return n[1]._ID
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else:
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return 0
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def set_val(self, val):
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self._set_cont_cls()
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Envelope.set_val(self, val)
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def _from_char(self, char):
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self._set_cont_cls()
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Envelope._from_char(self, char)
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def _set_cont_cls(self):
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ne = 1
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if self._env:
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p = self.get_prev()
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if p:
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# get NextExt from previous GTPUHdrExt
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ne = p['NextExt'].get_val()
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elif self._env._env:
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# get NextExt from GTPUHdrOpt
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ne = self._env._env['GTPUHdrOpt']['NextExt'].get_val()
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if ne in GTPUHdrExtCont_dict:
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Cont = GTPUHdrExtCont_dict[ne].clone()
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Cont.set_blauto(lambda: self._get_cont_len())
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self.replace(self[1], Cont)
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#------------------------------------------------------------------------------#
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@ -258,35 +202,24 @@ class GTPUHdrExt133(GTPUHdrExtAuto):
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# TS 29.281, section 5.1
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#------------------------------------------------------------------------------#
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# Warning: this GTPUHdrExtList is not friendly to build, as the user requires to
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# explicitely add GTPUHdrExt.. into it when building a message
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class GTPUHdrExtList(Envelope):
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_GEN = ()
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_HdrExt = {
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3 : GTPUHdrExt3,
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32 : GTPUHdrExt32,
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64 : GTPUHdrExt64,
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129 : GTPUHdrExt129,
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130 : GTPUHdrExt3,
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131 : GTPUHdrExt131,
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132 : GTPUHdrExt132,
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133 : GTPUHdrExt133,
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192 : GTPUHdrExt192
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}
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class GTPUHdrExtList(Sequence):
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_GEN = GTPUHdrExt()
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def _from_char(self, char):
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if self.get_trans():
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return
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self.__init__()
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self.set_val(None)
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l = 0
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p = self.get_prev()
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if p and not p.get_trans():
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neid = p['NextExt'].get_val()
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while neid > 0 and char.len_bit() >= 32:
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ne = self._HdrExt.get(neid, GTPUHdrExtAuto)()
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ne._from_char(char)
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self.append(ne)
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neid = ne['NextExt'].get_val()
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if not p:
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return
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l += 1
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self.set_num(l)
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self[-1]._from_char(char)
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while self[-1]['NextExt'].get_val() != 0:
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l += 1
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self.set_num(l)
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self[-1]._from_char(char)
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class GTPUHdrOpt(Envelope):
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@ -298,19 +231,19 @@ class GTPUHdrOpt(Envelope):
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def __init__(self, *args, **kwargs):
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Envelope.__init__(self, *args, **kwargs)
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self[-1].set_valauto(lambda: self._get_next_hdr())
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self[-1].set_valauto(lambda: self._get_ne())
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def _get_next_hdr(self):
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def _get_ne(self):
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n = self.get_next()
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if isinstance(n, GTPUHdrExtList) and len(n._content) and hasattr(n[0], '_ID'):
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return n[0]._ID
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if isinstance(n, GTPUHdrExtList) and n.get_num():
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return n[0][1]._ID
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else:
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return 0
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ProtType_dict = {
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0 : 'GTP prime',
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1 : 'GTP',
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1 : 'GTP', # the one for GTP-U
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}
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GTPUType_dict = {
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@ -324,13 +257,13 @@ GTPUType_dict = {
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}
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class GTPUType(IntEnum):
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EchoRequest = 1
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EchoResponse = 2
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ErrorIndication = 26
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SupportedExtensionHeadersNotification = 31
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TunnelStatus = 253
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EndMarker = 254
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GPDU = 255
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EchoRequest = 1
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EchoResponse = 2
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ErrorIndication = 26
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SupportedExtensionHeadersNotification = 31
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TunnelStatus = 253
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EndMarker = 254
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GPDU = 255
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class GTPUHdr(Envelope):
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@ -464,7 +397,7 @@ class GTPUIEPrivateExt(GTPUIE):
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# TS 29.281, section 7
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#------------------------------------------------------------------------------#
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class GTPUMsg(Envelope):
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class _GTPUMsg(Envelope):
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ENV_SEL_TRANS = False
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@ -499,9 +432,9 @@ class GTPUMsg(Envelope):
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# TS 29.281, section 7.2.1
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#------------------------------------------------------------------------------#
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class GTPUEchoRequest(GTPUMsg):
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class GTPUEchoRequest(_GTPUMsg):
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_GEN = (
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GTPUHdr(val={'Type': 1}),
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GTPUHdr(val={'Type': GTPUType.EchoRequest.value}),
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GTPUIEPrivateExt(hier=1, trans=True) # optional
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)
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@ -511,9 +444,9 @@ class GTPUEchoRequest(GTPUMsg):
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# TS 29.281, section 7.2.2
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#------------------------------------------------------------------------------#
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class GTPUEchoResponse(GTPUMsg):
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class GTPUEchoResponse(_GTPUMsg):
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_GEN = (
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GTPUHdr(val={'Type': 2}),
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GTPUHdr(val={'Type': GTPUType.EchoResponse.value}),
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GTPUIERecovery(hier=1),
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GTPUIEPrivateExt(hier=1, trans=True) # optional
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)
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@ -524,9 +457,9 @@ class GTPUEchoResponse(GTPUMsg):
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# TS 29.281, section 7.2.3
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#------------------------------------------------------------------------------#
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class GTPUSuppExtHdrNotif(GTPUMsg):
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class GTPUSuppExtHdrNotif(_GTPUMsg):
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_GEN = (
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GTPUHdr(val={'Type': 31}),
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GTPUHdr(val={'Type': GTPUType.SupportedExtensionHeadersNotification.value}),
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GTPUIEExtHdrList(hier=1)
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)
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@ -536,9 +469,9 @@ class GTPUSuppExtHdrNotif(GTPUMsg):
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# TS 29.281, section 7.3.1
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#------------------------------------------------------------------------------#
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class GTPUErrorInd(GTPUMsg):
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class GTPUErrorInd(_GTPUMsg):
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_GEN = (
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GTPUHdr(val={'Type': 26}),
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GTPUHdr(val={'Type': GTPUType.ErrorIndication.value}),
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GTPUIETEID(hier=1),
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GTPUIEPeerAddr(hier=1),
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GTPUIEPrivateExt(hier=1, trans=True) # optional
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@ -550,9 +483,9 @@ class GTPUErrorInd(GTPUMsg):
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# TS 29.281, section 7.3.2
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#------------------------------------------------------------------------------#
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class GTPUEndMarker(GTPUMsg):
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class GTPUEndMarker(_GTPUMsg):
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_GEN = (
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GTPUHdr(val={'Type': 254}),
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GTPUHdr(val={'Type': GTPUType.EndMarker.value}),
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GTPUIEPrivateExt(hier=1, trans=True) # optional
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)
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|
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@ -562,9 +495,9 @@ class GTPUEndMarker(GTPUMsg):
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# TS 29.281, section 7.3.3
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#------------------------------------------------------------------------------#
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class GTPUTunnelStatus(GTPUMsg):
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||||
class GTPUTunnelStatus(_GTPUMsg):
|
||||
_GEN = (
|
||||
GTPUHdr(val={'Type': 253}),
|
||||
GTPUHdr(val={'Type': GTPUType.TunnelStatus.value}),
|
||||
GTPUIEPrivateExt(hier=1, trans=True) # optional
|
||||
)
|
||||
|
||||
|
|
@ -576,7 +509,7 @@ class GTPUTunnelStatus(GTPUMsg):
|
|||
|
||||
class GPDU(Envelope):
|
||||
_GEN = (
|
||||
GTPUHdr(val={'Type': 255}),
|
||||
GTPUHdr(val={'Type': GTPUType.GPDU.value}),
|
||||
Buf('TPDU', hier=1, rep=REPR_HEX)
|
||||
)
|
||||
|
||||
|
|
@ -586,9 +519,10 @@ GTPUDispatcher = {
|
|||
2 : GTPUEchoResponse,
|
||||
26 : GTPUErrorInd,
|
||||
31 : GTPUSuppExtHdrNotif,
|
||||
253 : GTPUTunnelStatus,
|
||||
254 : GTPUEndMarker,
|
||||
255 : GPDU
|
||||
}
|
||||
255 : GPDU,
|
||||
}
|
||||
|
||||
|
||||
ERR_GTPU_BUF_TOO_SHORT = 1
|
||||
|
|
|
|||
Loading…
Reference in New Issue