L3 RRC/NAS developments

tools/rls-wireshark-dissector.lua

 --[[
+--
 -- Dissector for Radio Link Simulation Protocol
--- (used by UERANSIM <https://github.com/aligungr/UERANSIM>).
+-- (UERANSIM project <https://github.com/aligungr/UERANSIM>).
 --
 -- CC0-1.0 2021 - Louis Royer (<https://github.com/louisroyer/RLS-wireshark-dissector>)
+--
 --]]
 
---[[
--- ProtoFields
---]]
-local rls_protocol = Proto("RLS", "Radio Link Simulation Protocol")
-local version_major = ProtoField.uint8("rls.version_major", "RLS Version Major", base.DEC)
-local version_minor = ProtoField.uint8("rls.version_minor", "RLS Version Minor", base.DEC)
-local version_patch = ProtoField.uint8("rls.version_patch", "RLS Version Patch", base.DEC)
+local rlsProtocol = Proto("RLS", "UERANSIM Radio Link Simulation (RLS) Protocol")
+local fields = rlsProtocol.fields
 
-local message_type_name = {
-	[0] = "Reserved",
-	[1] = "Cell Info Request",
-	[2] = "Cell Info Response",
-	[3] = "PDU Delivery"
+local msgTypeNames = {
+    [0] = "[Reserved]",
+    [1] = "[Reserved]",
+    [2] = "[Reserved]",
+    [3] = "[Reserved]",
+    [4] = "Heartbeat",
+    [5] = "Heartbeat ACK",
+    [6] = "PDU Transmission",
+    [7] = "PDU Transmission ACK",
 }
 
-local message_type = ProtoField.uint8("rls.message_type", "RLS Message Type", base.DEC, message_type_name)
-local sti = ProtoField.uint64("rls.sti", "RLS Temporary Identifier", base.HEX)
-
--- For cell Info Request
-local sim_pos_x = ProtoField.uint32("rls.sim_pos_x", "RLS Position X", base.DEC)
-local sim_pos_y = ProtoField.uint32("rls.sim_pos_y", "RLS Position Y", base.DEC)
-local sim_pos_z = ProtoField.uint32("rls.sim_pos_z", "RLS Position Z", base.DEC)
+local pduTypeNames = {
+    [0] = "[Reserved]",
+    [1] = "RRC",
+    [2] = "Data"
+}
 
--- For cell Info Response
-local mcc = ProtoField.uint16("rls.mcc", "MCC", base.DEC)
-local mnc = ProtoField.uint16("rls.mnc", "MNC", base.DEC)
-local long_mnc = ProtoField.bool("rls.long_mnc", "MNC is 3-digit", base.BOOL)
-local nci = ProtoField.uint64("rls.nci", "NR Cell Identity", base.HEX)
-local tac = ProtoField.uint32("rls.tac", "Tracking Area Code", base.DEC)
-local dbm = ProtoField.int32("rls.dbm", "RLS Signal Strength (dBm)", base.DEC)
-local gnb_name = ProtoField.string("rls.gnb_name", "gNB Name")
-local link_ip = ProtoField.string("rls.link_ip", "gNB Link IP")
+local rrcMsgTypeNames = {
+    [0] = "BCCH-BCH",
+    [1] = "BCCH-DL-SCH",
+    [2] = "DL-CCCH",
+    [3] = "DL-DCCH",
+    [4] = "PCCH",
+    [5] = "UL-CCCH",
+    [6] = "UL-CCCH1",
+    [7] = "UL-DCCH",
+}
 
--- For PDU Delivery
-local pdu_type_name = {
-	[0] = "Reserved",
-	[1] = "RRC",
-	[2] = "Data"
+local nrRrcDissectors = {
+    [0] = "nr-rrc.bcch.bch",
+    [1] = "nr-rrc.bcch.dl.sch",
+    [2] = "nr-rrc.dl.ccch",
+    [3] = "nr-rrc.dl.dcch",
+    [4] = "nr-rrc.pcch",
+    [5] = "nr-rrc.ul.ccch",
+    [6] = "nr-rrc.ul.ccch1",
+    [7] = "nr-rrc.ul.dcch",
 }
 
-local pdu_type = ProtoField.uint8("rls.pdu_type", "RLS PDU Type", base.DEC, pdu_type_name)
+fields.Version = ProtoField.string("rls.version", "Version")
+fields.MsgType = ProtoField.uint8("rls.message_type", "Message Type", base.DEC, msgTypeNames)
+fields.Sti = ProtoField.uint64("rls.sti", "Sender Node Temporary ID", base.DEC)
+fields.PduType = ProtoField.uint8("rls.pdu_type", "PDU Type", base.DEC, pduTypeNames)
+fields.PduId = ProtoField.uint32("rls.pdu_id", "PDU ID", base.DEC)
+fields.RrcMsgType = ProtoField.uint32("rls.rrc_message_type", "RRC Message Type", base.DEC, rrcMsgTypeNames)
+fields.PduLength = ProtoField.uint32("rls.pdu_length", "PDU Length", base.DEC)
+fields.PduSessionId = ProtoField.uint32("rls.pdu_session_id", "PDU Session ID", base.DEC)
+fields.AcknowledgeItem = ProtoField.uint32("rls.ack_item", "PDU ID")
+fields.Dbm = ProtoField.int32("rls.dbm", "RLS Signal Strength (dBm)", base.DEC)
+fields.PosX = ProtoField.uint32("rls.pos_x", "RLS Position X", base.DEC)
+fields.PosY = ProtoField.uint32("rls.pos_y", "RLS Position Y", base.DEC)
+fields.PosZ = ProtoField.uint32("rls.pos_z", "RLS Position Z", base.DEC)
 
-local rrc_channel_name = {
-	[0] = "BCCH-BCH",
-	[1] = "BCCH-DL-SCH",
-	[2] = "DL-CCCH",
-	[3] = "DL-DCCH",
-	[4] = "PCCH",
-	[5] = "UL-CCCH",
-	[6] = "UL-CCCH1",
-	[7] = "UL-DCCH",
-}
+function rlsProtocol.dissector(buffer, pinfo, tree)
+    if buffer:len() == 0 then return end
+    if buffer(0, 1):uint() ~= 0x03 then return end
 
-local rrc_channel_dissector = {
-	[0] = "nr-rrc.bcch.bch",
-	[1] = "nr-rrc.bcch.dl.sch",
-	[2] = "nr-rrc.dl.ccch",
-	[3] = "nr-rrc.dl.dcch",
-	[4] = "nr-rrc.pcch",
-	[5] = "nr-rrc.ul.ccch",
-	[6] = "nr-rrc.ul.ccch1",
-	[7] = "nr-rrc.ul.dcch",
-}
+    pinfo.cols.protocol = rlsProtocol.name
 
-local rrc_channel = ProtoField.uint32("rls.rrc_channel", "RRC Channel", base.DEC, rrc_channel_name)
-local session_id = ProtoField.uint32("rls.session_id", "PDU Session ID", base.DEC)
+    local versionNumber = buffer(1, 1):uint() .. "." .. buffer(2, 1):uint() .. "." .. buffer(3, 1):uint()
+    local subtree = tree:add(rlsProtocol, buffer(), "UERANSIM Radio Link Simulation (RLS) protocol")
 
---[[
--- Dissector definition
---]]
-rls_protocol.fields = {
-	version_major, version_minor, version_patch, message_type, sti,
-	sim_pos_x, sim_pos_y, sim_pos_z,
-	mcc, mnc, long_mnc, nci, tac, dbm, gnb_name, link_ip,
-	pdu_type, rrc_channel, session_id,
-}
+    subtree:add(fields.Version, buffer(1, 3), versionNumber)
+    subtree:add(fields.MsgType, buffer(4, 1))
+    local msgType = buffer(4, 1):uint()
 
-function rls_protocol.dissector(buffer, pinfo, tree)
-	local length = buffer:len()
-	if length == 0 then return end
-	if buffer(0,1):uint() ~= 0x03 then return end
+    pinfo.cols.info = msgTypeNames[msgType]
+    subtree:add(fields.Sti, buffer(5, 8))
 
-	pinfo.cols.protocol = rls_protocol.name
-	local version_number = buffer(1,1):uint().."."
-		..buffer(2,1):uint().."."
-		..buffer(3,1):uint()
-	local subtree = tree:add(rls_protocol, buffer(), "RLS Protocol Version "..version_number)
-	local version = subtree:add(rls_protocol, buffer(2,3), "Version: "..version_number)
-	version:add(version_major, buffer(1,1))
-	version:add(version_minor, buffer(2,1))
-	version:add(version_patch, buffer(3,1))
-	subtree:add(message_type, buffer(4,1))
-	local msg_type = buffer(4,1):uint()
-	if msg_type <=0 or msg_type > 3 then return end
-	pinfo.cols.info = message_type_name[msg_type]
-	subtree:append_text(" - "..message_type_name[msg_type])
-	subtree:add(sti, buffer(5,8))
-	if msg_type == 1 then -- Cell Info Request
-		subtree:add(sim_pos_x, buffer(13,4))
-		subtree:add(sim_pos_y, buffer(17,4))
-		subtree:add(sim_pos_z, buffer(21,4))
-	elseif msg_type == 2 then -- Cell Info Response
-		subtree:add(mcc, buffer(13,2))
-		local mnc_tree = subtree:add(rls_protocol, buffer(15,3), "MNC: "..tostring(buffer(15,2):uint()))
-		mnc_tree:add(mnc, buffer(15,2))
-		mnc_tree:add(long_mnc, buffer(17,1))
-		subtree:add(nci, buffer(18,8))
-		subtree:add(tac, buffer(26,4))
-		subtree:add(dbm, buffer(30,4))
-		local gnb_name_len = buffer(34,4):uint()
-		subtree:add(gnb_name, buffer(38,gnb_name_len))
-		local link_ip_size = buffer(38+gnb_name_len,4):uint()
-		subtree:add(link_ip, buffer(42+gnb_name_len,link_ip_size))
-	elseif msg_type == 3 then -- PDU Delivery
-		subtree:add(pdu_type, buffer(13,1))
-		local pdu_type_value = buffer(13,1):uint()
-		local pdu_len = buffer(14,4):uint()
-		local payload_len = buffer(18+pdu_len,4):uint()
-		if pdu_type_value == 1 then -- RRC
-			subtree:add(rrc_channel, buffer(22+pdu_len,payload_len))
-			local channel = buffer(22+pdu_len,payload_len):uint()
-			Dissector.get(rrc_channel_dissector[channel]):call(buffer(18,pdu_len):tvb(), pinfo, tree)
-		elseif pdu_type_value == 2 then -- DATA
-			subtree:add(session_id, buffer(22+pdu_len,payload_len))
-			Dissector.get("ip"):call(buffer(18,pdu_len):tvb(), pinfo, tree)
-		end
-	end
+    if msgType == 4 then -- Heartbeat
+        subtree:add(fields.PosX, buffer(13,4))
+        subtree:add(fields.PosY, buffer(17,4))
+        subtree:add(fields.PosZ, buffer(21,4))
+    elseif msgType == 5 then -- Heartbeat ACK
+        subtree:add(fields.Dbm, buffer(13,4))
+    elseif msgType == 6 then -- PDU Transmission
+        local pduType = buffer(13, 1):uint()
+        subtree:add(fields.PduType, buffer(13, 1))
+        subtree:add(fields.PduId, buffer(14, 4))
+        if pduType == 1 then -- RRC PDU
+            local rrcMsgType = buffer(18, 4):uint()
+            local pduLength = buffer(22, 4):uint()
+            subtree:add(fields.RrcMsgType, buffer(18, 4))
+            subtree:add(fields.PduLength, buffer(22, 4))
+            Dissector.get(nrRrcDissectors[rrcMsgType]):call(buffer(26, pduLength):tvb(), pinfo, tree)
+        elseif (pduType == 2) then -- Data PDU
+            subtree:add(fields.PduSessionId, buffer(18, 4))
+            local pduLength = buffer(22, 4):uint()
+            subtree:add(fields.PduLength, buffer(22, 4))
+            Dissector.get("ip"):call(buffer(26, pduLength):tvb(), pinfo, tree)
+        end
+    elseif msgType == 7 then -- PDU Transmission ACK
+        local ackCount = buffer(13, 4):uint()
+        local ackArray = subtree:add(rlsProtocol, buffer(13, 4), "Acknowledge List (" .. ackCount .. ")")
+        for i = 1,ackCount,1 do
+            ackArray:add(fields.AcknowledgeItem, buffer(17 + (i - 1) * 4, 4))
+        end
+    end
 end
 
 local udp_port = DissectorTable.get("udp.port")
-udp_port:add(4997, rls_protocol)
+udp_port:add(4997, rlsProtocol)