src/codec_utils/e2ap.lua

   1 -------------------------------------------------------------------------------------
   2 -- script-name: e2ap.lua
   3 -- This script is a plugin to dissect packets that are exchanged over E2AP interface
   4 -------------------------------------------------------------------------------------
   5
   6 ----------------------------------------
   7 -- creates a Proto object, but doesn't register it yet
   8 local E2AP = Proto("E2AP","E2 Application Protocol")
   9
  10 ----------------------------------------
  11 local E2apPduEnum = {
  12                 [0] = "initiatingMessage",
  13                 [1] = "successfulOutcome",
  14                 [2] = "unsuccessfulOutcome" }
  15
  16 local E2ProcedureCode = {
  17                 [1] = "ProcedureCodeE2_id_E2setup",
  18                 [2] = "ProcedureCodeE2_id_ErrorIndicationE2",
  19                 [3] = "ProcedureCodeE2_id_Reset",
  20                 [4] = "ProcedureCodeE2_id_RICcontrol",
  21                 [5] = "ProcedureCodeE2_id_RICindication",
  22                 [6] = "ProcedureCodeE2_id_RICserviceQuery",
  23                 [7] = "ProcedureCodeE2_id_RICserviceUpdate",
  24                 [8] = "ProcedureCodeE2_id_RICsubscription",
  25                 [9] = "ProcedureCodeE2_id_RICsubscriptionDelete" }
  26
  27 local E2Criticality ={
  28                 [0] = "CriticalityE2_reject",
  29                 [1] = "CriticalityE2_ignore",
  30                 [2] = "CriticalityE2_notify" }
  31
  32 local E2InitiatingMessagePresenceEnum = {
  33                 [0] = "InitiatingMessageE2__value_PR_NOTHING",
  34                 [1] = "InitiatingMessageE2__value_PR_RICsubscriptionRequest",
  35                 [2] = "InitiatingMessageE2__value_PR_RICsubscriptionDeleteRequest",
  36                 [3] = "InitiatingMessageE2__value_PR_RICserviceUpdate",
  37                 [4] = "InitiatingMessageE2__value_PR_RICcontrolRequest",
  38                 [5] = "InitiatingMessageE2__value_PR_E2setupRequest",
  39                 [6] = "InitiatingMessageE2__value_PR_ResetRequest",
  40                 [7] = "InitiatingMessageE2__value_PR_RICindication",
  41                 [8] = "InitiatingMessageE2__value_PR_RICserviceQuery",
  42                 [9] = "InitiatingMessageE2__value_PR_ErrorIndicationE2" }
  43
  44 local E2PotocolIEs = {
  45         [1] = "id_CauseE2",
  46         [2] = "id_CriticalityDiagnosticsE2",
  47         [3] = "id_GlobalE2node_ID",
  48         [4] = "id_GlobalRIC_ID",
  49         [5] = "id_RANfunctionID",
  50         [6] = "id_RANfunctionID_Item",
  51         [7] = "id_RANfunctionIEcause_Item",
  52         [8] = "id_RANfunction_Item",
  53         [9] = "id_RANfunctionsAccepted",
  54         [10] = "id_RANfunctionsAdded",
  55         [11] = "id_RANfunctionsDeleted",
  56         [12] = "id_RANfunctionsModified",
  57         [13] = "id_RANfunctionsRejected",
  58         [14] = "id_RICaction_Admitted_Item",
  59         [15] = "id_RICactionID",
  60         [16] = "id_RICaction_NotAdmitted_Item",
  61         [17] = "id_RICactions_Admitted",
  62         [18] = "id_RICactions_NotAdmitted",
  63         [19] = "id_RICaction_ToBeSetup_Item",
  64         [20] = "id_RICcallProcessID",
  65         [21] = "id_RICcontrolAckRequest",
  66         [22] = "id_RICcontrolHeader",
  67         [23] = "id_RICcontrolMessage",
  68         [24] = "id_RICcontrolStatus",
  69         [25] = "id_RICindicationHeader",
  70         [26] = "id_RICindicationMessage",
  71         [27] = "id_RICindicationSN",
  72         [28] = "id_RICindicationType",
  73         [29] = "id_RICrequestID",
  74         [30] = "id_RICsubscriptionDetails",
  75         [31] = "id_TimeToWaitE2",
  76         [32] = "id_RICcontrolOutcome"
  77 }
  78
  79
  80 --payload fields start
  81 local RIC_indication = "Ric Indication Message"
  82
  83 local Initiating_Message_Type_Value = {
  84         value = "value"--, nil,E2InitiatingMessagePresenceEnum, 0xFF)
  85 }
  86
  87 local InitiatingMessageE2 = {
  88         Initiating_Message_E2 = "Initiating Message E2",
  89         procedureCode = "ProcedureCode: ",
  90         criticality   = "Criticality: "
  91 }
  92         --value       = ProtoField.uint16("Initiating_Message_Type_Value.value", "value")
  93
  94 local InitiatingMessageE2__value_u = {
  95 RICsubscriptionRequest           = "RIC subscription Request",
  96 RICsubscriptionDeleteRequest     = "RIC subscription Delete Request",
  97 RICserviceUpdate                 = "RIC service Update",
  98 RICcontrolRequest                = "RIC control Request",
  99 E2setupRequest                   = "E2 setup Request",
 100 ResetRequest                     = "Reset Request",
 101 RICindication                    = "RIC indication",
 102 RICserviceQuery                  = "RIC service Query",
 103 ErrorIndicationE2                = "Error Indication E2"
 104 }
 105
 106 local successfulOutcomeE2 = {
 107         successOutcomeMsg = "successfulOutcome",
 108         procedureCode = "procedureCode: ",
 109         criticality = "criticality: ",
 110         valueLen = "Value Length: ",
 111         value = "value"
 112 }
 113
 114 local e2SetupResponse = "E2SetupResponse"
 115 local protocolIE = "protocolIEs: "
 116 local protocolItem = "Item "
 117 local protocolIEField = {
 118         protocolIEFieldMsg = "ProtocolIE-Field",
 119         id = "id: ",
 120         criticality = "criticality: ",
 121         valueLen = "Value Length: ",
 122         value = "Value"
 123 }
 124
 125 E2AP.fields = {
 126         --successfulOutcomeE2.procedureCode
 127 }
 128
 129 function fetch2Bytes(tvbuf, offset)
 130         local fbyte = tvbuf:range(offset, 1):le_uint()
 131         local fbyte1 = bit.lshift(fbyte, 8)
 132         local sbyte = tvbuf:range(offset + 1, 1):le_uint()
 133         local result = bit.bor(fbyte1, sbyte)
 134         return result
 135 end
 136 function addE2apInitiatingMessageToTree(tvbuf, pktinfo, tree, offset, endianness)
 137
 138         local info = tvbuf:range(offset, 1)
 139         local initiatingMessageE2Tree = tree:add(info, InitiatingMessageE2.Initiating_Message_E2)
 140
 141         local procId = tvbuf:range(offset,1):le_uint()
 142         strId = tostring(E2ProcedureCode[procId]) .. " (" .. tostring(procId) ..")"
 143         tree:add(tvbuf:range(offset,1), InitiatingMessageE2.procedureCode .. strId)
 144         offset = offset + 1
 145
 146         local criticalityId = tvbuf:range(offset,1):le_uint()
 147         strId = tostring(E2Criticality[criticalityId]) .. " (" .. tostring(criticalityId) ..")"
 148         tree:add(tvbuf:range(offset,1), InitiatingMessageE2.criticality .. strId)
 149         offset = offset + 1
 150
 151         -- value cfg
 152         --local valueinitiatingMessageType = initiatingMessageE2Tree:add(tvbuf:range(offset,offset),Initiating_Message_E2.value)
 153
 154 end
 155
 156 function addGobalRICIdToTree(tvbuf, valueTree, offset, valueLen, endianness)
 157 end
 158
 159 function addE2SetupResponseToTree(tvbuf, pktinfo, valueTree, offset, pktlen, endianness)
 160         pktinfo.cols.info:set("E2 Setup Response")
 161
 162         local e2SetupResponseTree = valueTree:add(tvbuf:range(offset, pktlen), e2SetupResponse)
 163
 164 --        local extBit = tvbuf:range(offset,1):le_uint()
 165 --      if(extBit == 0) then
 166 --              e2SetupResponseTree:add(tvbuf:range(offset,1), "<" .. extBit .. "... .... Extension Bit: FALSE>")
 167 --      else
 168 --              e2SetupResponseTree:add(tvbuf:range(offset,1), "<" .. extBit .. "... .... Extension Bit: TRUE>")
 169 --      end
 170         offset = offset + 1
 171
 172         local seqLen = fetch2Bytes(tvbuf, offset)
 173 --      e2SetupResponseTree:add(tvbuf:range(offset, 2), "<Sequence-Of Length: " .. seqLen .. ">")
 174         local protoIeTree = e2SetupResponseTree:add(tvbuf:range(offset, 2), protocolIE .. seqLen .. " items")
 175         offset = offset + 2
 176
 177         for ie=0, seqLen-1, 1
 178         do
 179             local protocolIEId = fetch2Bytes(tvbuf, offset)
 180             strId = tostring(E2PotocolIEs[protocolIEId])
 181             local itemTree = protoIeTree:add(protocolItem .. ie .. ": " .. strId)
 182
 183             strId = strId .. " (" .. tostring(protocolIEId) ..")"
 184             local protocolFieldTree = itemTree:add(tvbuf:range(offset,2), protocolIEField.protocolIEFieldMsg)
 185                 protocolFieldTree:add(protocolIEField.id .. strId)
 186                 offset = offset + 2
 187
 188                 local criticalityId = tvbuf:range(offset,1):le_uint()
 189 --              protocolFieldTree:add(tvbuf:range(offset,1), "<Enumerated Index: " .. criticalityId ..">")
 190                 strId = tostring(E2Criticality[criticalityId]) .. " (" .. tostring(criticalityId) ..")"
 191                 protocolFieldTree:add(tvbuf:range(offset,1), protocolIEField.criticality .. strId)
 192                 offset = offset + 1
 193
 194                 local valueLen = tvbuf:range(offset,1):le_uint()
 195 --              protocolFieldTree:add(tvbuf:range(offset,1), "<" .. protocolIEField.valueLen .. valueLen ..">")
 196                 offset = offset + 1
 197
 198                 local valueTree = protocolFieldTree:add(tvbuf:range(offset, valueLen), protocolIEField.value)
 199
 200                 if(protocolIEId == 4) then
 201                         addGobalRICIdToTree(tvbuf, valueTree, offset, valueLen, endianness)
 202                 end
 203         end
 204 end
 205
 206 function addE2apSuccessfulOutcomeToTree(tvbuf, pktinfo, tree, offset, pktlen, endianness)
 207         local successfulOutcomeTree = tree:add(tvbuf:range(offset, (pktlen-offset)), successfulOutcomeE2.successOutcomeMsg)
 208         local procId = tvbuf:range(offset,1):le_uint()
 209         strId = tostring(E2ProcedureCode[procId]) .. " (" .. tostring(procId) ..")"
 210         successfulOutcomeTree:add(tvbuf:range(offset,1), successfulOutcomeE2.procedureCode .. strId)
 211         offset = offset + 1
 212
 213         local criticalityId = tvbuf:range(offset,1):le_uint()
 214 --      successfulOutcomeTree:add(tvbuf:range(offset,1), "<Enumerated Index: " .. criticalityId ..">")
 215         strId = tostring(E2Criticality[criticalityId]) .. " (" .. tostring(criticalityId) ..")"
 216         successfulOutcomeTree:add(tvbuf:range(offset,1), successfulOutcomeE2.criticality .. strId)
 217         offset = offset + 1
 218
 219         local valueLen = tvbuf:range(offset,1):le_uint()
 220 --      successfulOutcomeTree:add(tvbuf:range(offset,1), "<" .. successfulOutcomeE2.valueLen .. valueLen ..">")
 221         offset = offset + 1
 222
 223         local valueTree = successfulOutcomeTree:add(tvbuf:range(offset, valueLen), successfulOutcomeE2.value)
 224
 225         if(procId == 1) then
 226                 addE2SetupResponseToTree(tvbuf, pktinfo, valueTree, offset, valueLen, endianness)
 227         end
 228 end
 229 ----------------------------------------
 230 -- The following creates the callback function for the dissector.
 231 -- The 'tvbuf' is a Tvb object, 'pktinfo' is a Pinfo object, and 'root' is a TreeItem object.
 232 -- Whenever Wireshark dissects a packet that our Protocol is hooked into, it will call
 233 -- this function and pass it these arguments for the packet it's dissecting.
 234 function E2AP.dissector(tvbuf,pktinfo,root)
 235
 236     -- set the protocol column to show our protocol name
 237     pktinfo.cols.protocol:set("E2AP")
 238
 239     -- We want to check that the packet size is rational during dissection, so let's get the length of the
 240     -- packet buffer (Tvb).
 241     local pktlen = tvbuf:reported_length_remaining()
 242
 243     -- We start by adding our protocol to the dissection display tree.
 244     -- A call to tree:add_packet_field() returns the child created, so we can add more "under" it using that return value.
 245     -- The second argument is how much of the buffer/packet this added tree item covers/represents
 246     local offset = 0
 247     stream = " "
 248     local endianness = string.byte(string.dump(function() end), 7)
 249     local tree = root:add(E2AP, tvbuf:range(offset,pktlen))
 250
 251
 252     -- Now let's add our protocol header fields under the protocol tree we just created.
 253
 254     local fByte = tvbuf:range(offset,1):le_uint()
 255     local apiId = bit.rshift(fByte, 5)
 256 --    tree:add(tvbuf:range(offset,1), "<Choice Index: " .. apiId ..">")
 257     strId = tostring(E2apPduEnum[apiId]) .. " (" .. tostring(apiId) ..")"
 258     local e2apTree = tree:add(tvbuf:range(offset,1), "E2AP-PDU: " .. strId)
 259         offset = offset + 1
 260
 261     -- Now let's add our protocol fields under the protocol tree we just created.
 262         if (apiId == 0) then
 263                 addE2apInitiatingMessageToTree(tvbuf, pktinfo, e2apTree, offset, endianness)
 264         end
 265         if(apiId == 1) then
 266                 addE2apSuccessfulOutcomeToTree(tvbuf, pktinfo, e2apTree, offset, pktlen, endianness)
 267         end
 268
 269 end -- end of dissector funciton
 270
 271         ----------------------------------------
 272         -- we want to have our protocol dissection invoked for a specific UDP port,
 273         -- so get the udp dissector table and add our protocol to it
 274         DissectorTable.get("sctp.port"):add(36421, E2AP)
 275         -- our protocol (Proto) gets automatically registered after this script finishes loading
 276         ----------------------------------------
 277