src/codec_utils/e2ap.lua

   1 ----------------------------------------
   2 -- script-name: e2ap.lua
   3 ----------------------------------------
   4
   5 ----------------------------------------
   6 -- creates a Proto object, but doesn't register it yet
   7 local E2AP = Proto("E2AP","E2 Application Protocol")
   8
   9 ----------------------------------------
  10 local E2apPduEnum = {
  11                 [0] = "initiatingMessage",
  12                 [1] = "successfulOutcome",
  13                 [2] = "unsuccessfulOutcome" }
  14
  15 local ProcedureCodeE2 = {
  16                 [1] = "ProcedureCodeE2_id_E2setup",
  17                 [2] = "ProcedureCodeE2_id_ErrorIndicationE2",
  18                 [3] = "ProcedureCodeE2_id_Reset",
  19                 [4] = "ProcedureCodeE2_id_RICcontrol",
  20                 [5] = "ProcedureCodeE2_id_RICindication",
  21                 [6] = "ProcedureCodeE2_id_RICserviceQuery",
  22                 [7] = "ProcedureCodeE2_id_RICserviceUpdate",
  23                 [8] = "ProcedureCodeE2_id_RICsubscription",
  24                 [9] = "ProcedureCodeE2_id_RICsubscriptionDelete" }
  25
  26 local CriticalityE2 ={
  27                 [0] = "CriticalityE2_reject",
  28                 [1] = "CriticalityE2_ignore",
  29                 [2] = "CriticalityE2_notify" }
  30
  31 local InitiatingMessageE2ValuePrEnum = {
  32                 [0] = "InitiatingMessageE2__value_PR_NOTHING",
  33                 [1] = "InitiatingMessageE2__value_PR_RICsubscriptionRequest",
  34                 [2] = "InitiatingMessageE2__value_PR_RICsubscriptionDeleteRequest",
  35                 [3] = "InitiatingMessageE2__value_PR_RICserviceUpdate",
  36                 [4] = "InitiatingMessageE2__value_PR_RICcontrolRequest",
  37                 [5] = "InitiatingMessageE2__value_PR_E2setupRequest",
  38                 [6] = "InitiatingMessageE2__value_PR_ResetRequest",
  39                 [7] = "InitiatingMessageE2__value_PR_RICindication",
  40                 [8] = "InitiatingMessageE2__value_PR_RICserviceQuery",
  41                 [9] = "InitiatingMessageE2__value_PR_ErrorIndicationE2" }
  42
  43 --payload fields start
  44 local RIC_indication = "Ric Indication Message"
  45
  46 local Initiating_Message_Type_Value = {
  47         value = "value"--, nil,InitiatingMessageE2ValuePrEnum, 0xFF)
  48 }
  49
  50 local InitiatingMessageE2 = {
  51         Initiating_Message_E2 = "Initiating Message E2",
  52         procedureCode = "ProcedureCode: ",
  53         criticality   = "Criticality: "
  54 }
  55         --value       = ProtoField.uint16("Initiating_Message_Type_Value.value", "value")
  56
  57 local InitiatingMessageE2__value_u = {
  58 RICsubscriptionRequest           = "RIC subscription Request",
  59 RICsubscriptionDeleteRequest = "RIC subscription Delete Request",
  60 RICserviceUpdate                         = "RIC service Update",
  61 RICcontrolRequest                        = "RIC control Request",
  62 E2setupRequest                           = "E2 setup Request",
  63 ResetRequest                             = "Reset Request",
  64 RICindication                            = "RIC indication",
  65 RICserviceQuery                          = "RIC service Query",
  66 ErrorIndicationE2                        = "Error Indication E2"
  67 }
  68
  69 local successfulOutcomeE2 = {
  70         successOutcomeMsg = "successfulOutcome",
  71         procedureCode = "procedureCode: ",
  72         criticality = "criticality: "
  73 }
  74
  75 local e2SetupResponse = {
  76         e2SetupResponseMsg = "E2SetupResponse"
  77 }
  78
  79 E2AP.fields = {
  80         --successfulOutcomeE2.procedureCode
  81 }
  82
  83 function addE2apInitiatingMessageToTree(tvbuf, tree, offset, endianness)
  84
  85         local info = tvbuf:range(offset, 1)
  86         local initiatingMessageE2Tree = tree:add(info, InitiatingMessageE2.Initiating_Message_E2)
  87
  88         local procId = tvbuf:range(offset,1):le_uint()
  89         strId = tostring(ProcedureCodeE2[procId]) .. " (" .. tostring(procId) ..")"
  90         tree:add(tvbuf:range(offset,1), InitiatingMessageE2.procedureCode .. strId)
  91         offset = offset + 1
  92
  93         local criticalityId = tvbuf:range(offset,1):le_uint()
  94         strId = tostring(CriticalityE2[criticalityId]) .. " (" .. tostring(criticalityId) ..")"
  95         tree:add(tvbuf:range(offset,1), InitiatingMessageE2.criticality .. strId)
  96         offset = offset + 1
  97
  98         -- value cfg
  99         --local valueinitiatingMessageType = initiatingMessageE2Tree:add(tvbuf:range(offset,offset),Initiating_Message_E2.value)
 100
 101 end
 102
 103 function addE2SetupResponseToTree(tvbuf, tree, offset, pktlen, endianness)
 104         local valueTree = tree:add(tvbuf:range(offset, (pktlen - offset)), "value")
 105                 local e2SetupResponseTree = valueTree:add(e2SetupResponse.e2SetupResponseMsg)
 106
 107                         local extBit = tvbuf:range(offset,1):le_uint()
 108                         if(extBit == 0) then
 109                                 e2SetupResponseTree:add(tvbuf:range(offset,1), "<" .. extBit .. "... .... Extension Bit: FALSE>")
 110                         else
 111                                 e2SetupResponseTree:add(tvbuf:range(offset,1), "<" .. extBit .. "... .... Extension Bit: TRUE>")
 112                         end
 113                         offset = offset + 1
 114
 115                         local seqLen = tvbuf:range(offset, 2):le_uint()
 116                         e2SetupResponseTree:add(tvbuf:range(offset, 2), "<Sequence-Of Length: " .. seqLen .. ">")
 117                         offset = offset + 2
 118
 119 end
 120
 121 function addE2apSuccessfulOutcomeToTree(tvbuf, tree, offset, pktlen, endianness)
 122         local successfulOutcomeTree = tree:add(tvbuf:range(offset, (pktlen-offset)), successfulOutcomeE2.successOutcomeMsg)
 123                 local procId = tvbuf:range(offset,1):le_uint()
 124                 strId = tostring(ProcedureCodeE2[procId]) .. " (" .. tostring(procId) ..")"
 125                 successfulOutcomeTree:add(tvbuf:range(offset,1), successfulOutcomeE2.procedureCode .. strId)
 126                 offset = offset + 1
 127
 128                 local criticalityId = tvbuf:range(offset,1):le_uint()
 129                 successfulOutcomeTree:add(tvbuf:range(offset,1), "<Enumerated Index: " .. criticalityId ..">")
 130         strId = tostring(CriticalityE2[criticalityId]) .. " (" .. tostring(criticalityId) ..")"
 131         successfulOutcomeTree:add(tvbuf:range(offset,1), successfulOutcomeE2.criticality .. strId)
 132         offset = offset + 1
 133
 134                 local valueLen = tvbuf:range(offset,1):le_uint()
 135                 successfulOutcomeTree:add(tvbuf:range(offset,1), "<Value length: " .. valueLen ..">")
 136                 offset = offset + 1
 137
 138                 if(procId == 1) then
 139                         addE2SetupResponseToTree(tvbuf, successfulOutcomeTree, offset, pktlen, endianness)
 140                 end
 141 end
 142 ----------------------------------------
 143 -- The following creates the callback function for the dissector.
 144 -- The 'tvbuf' is a Tvb object, 'pktinfo' is a Pinfo object, and 'root' is a TreeItem object.
 145 -- Whenever Wireshark dissects a packet that our Protocol is hooked into, it will call
 146 -- this function and pass it these arguments for the packet it's dissecting.
 147 function E2AP.dissector(tvbuf,pktinfo,root)
 148
 149     -- set the protocol column to show our protocol name
 150     pktinfo.cols.protocol:set("E2AP")
 151
 152     -- We want to check that the packet size is rational during dissection, so let's get the length of the
 153     -- packet buffer (Tvb).
 154     local pktlen = tvbuf:reported_length_remaining()
 155
 156     -- We start by adding our protocol to the dissection display tree.
 157     -- A call to tree:add_packet_field() returns the child created, so we can add more "under" it using that return value.
 158     -- The second argument is how much of the buffer/packet this added tree item covers/represents
 159     local offset = 0
 160     stream = " "
 161     local endianness = string.byte(string.dump(function() end), 7)
 162     local tree = root:add(E2AP, tvbuf:range(offset,pktlen))
 163
 164
 165     -- Now let's add our protocol header fields under the protocol tree we just created.
 166
 167     local fByte = tvbuf:range(offset,1):le_uint()
 168         local apiId = bit.rshift(fByte, 5)
 169         tree:add(tvbuf:range(offset,1), "<Choice Index: " .. apiId ..">")
 170     strId = tostring(E2apPduEnum[apiId]) .. " (" .. tostring(apiId) ..")"
 171     tree:add(tvbuf:range(offset,1), "E2AP-PDU: " .. strId)
 172         offset = offset + 1
 173
 174     -- Now let's add our protocol fields under the protocol tree we just created.
 175         if (apiId == 0) then
 176                 addE2apInitiatingMessageToTree(tvbuf, tree, offset, endianness)
 177         end
 178         if(apiId == 1) then
 179                 addE2apSuccessfulOutcomeToTree(tvbuf, tree, offset, pktlen, endianness)
 180         end
 181
 182 end -- end of dissector funciton
 183
 184         ----------------------------------------
 185         -- we want to have our protocol dissection invoked for a specific UDP port,
 186         -- so get the udp dissector table and add our protocol to it
 187         DissectorTable.get("sctp.port"):add(36421, E2AP)
 188         -- our protocol (Proto) gets automatically registered after this script finishes loading
 189         ----------------------------------------
 190