Fix registration (#5)

Managing modules load order using require doesn't always work (especially when installing the plugin globally. It is better to register subprotocols in init() function which is called when every module is registered.

.luacheckrc

@@ -12,5 +12,7 @@ stds.wireshark = {
 		"ProtoField",
 		"base",
 		"ftypes",
+		"package",
+		"set_plugin_info",
 	}
 }

rls-3-1.lua → protocol/rls-3-1.lua

@@ -6,8 +6,6 @@
 -- CC0-1.0 2021 - Louis Royer (<https://github.com/louisroyer/RLS-wireshark-dissector>)
 --
 --]]
-require("rls")
-
 local rlsProtocol31 = Proto("RLS-3.1", "UERANSIM 3.1.x Radio Link Simulation (RLS) Protocol")
 local fields = rlsProtocol31.fields
 
@@ -128,7 +126,9 @@ function rlsProtocol31.dissector(buffer, pinfo, tree)
 	end
 end
 
-local rls = DissectorTable.get("rls")
-rls:add(0x0301, rlsProtocol31)
-local udp_port = DissectorTable.get("udp.port")
-udp_port:add_for_decode_as(rlsProtocol31)
+function rlsProtocol31.init()
+	local rls = DissectorTable.get("rls")
+	rls:add(0x0301, rlsProtocol31)
+	local udp_port = DissectorTable.get("udp.port")
+	udp_port:add_for_decode_as(rlsProtocol31)
+end

rls-3-2.lua → protocol/rls-3-2.lua

@@ -6,8 +6,6 @@
 -- CC0-1.0 2021 - Louis Royer (<https://github.com/louisroyer/RLS-wireshark-dissector>)
 --
 --]]
-require("rls")
-
 local rlsProtocol32 = Proto("RLS-3.2", "UERANSIM 3.2.x Radio Link Simulation (RLS) Protocol")
 local fields = rlsProtocol32.fields
 
@@ -124,7 +122,9 @@ function rlsProtocol32.dissector(buffer, pinfo, tree)
 	end
 end
 
-local rls = DissectorTable.get("rls")
-rls:add(0x0302, rlsProtocol32)
-local udp_port = DissectorTable.get("udp.port")
-udp_port:add_for_decode_as(rlsProtocol32)
+function rlsProtocol32.init()
+	local rls = DissectorTable.get("rls")
+	rls:add(0x0302, rlsProtocol32)
+	local udp_port = DissectorTable.get("udp.port")
+	udp_port:add_for_decode_as(rlsProtocol32)
+end

rls.lua

@@ -7,53 +7,59 @@
 --
 --]]
 
--- This file must only be loaded once, but each version requires it.
-if package.loaded['rls'] == nil then
-	-- Update the following when adding new versions
-	local latestVersion = 0x0302
-	local oldestVersion = 0x0301
+local pluginVersion = "1.1.1"
+-- Update the following when adding new versions
+local latestVersion = 0x0302
+local oldestVersion = 0x0301
 
-	local rlsProtocol = Proto("RLS", "UERANSIM Radio Link Simulation (RLS) Protocol")
+local rlsProtocol = Proto("RLS", "UERANSIM Radio Link Simulation (RLS) Protocol")
+set_plugin_info({
+	version = pluginVersion,
+	author = "Louis Royer",
+	repository = "https://github.com/louisroyer/RLS-wireshark-dissector",
+	description = "Dissector for Radio Link Simulation Protocol"
+})
 
-	-- Create a DissectorTable to register dissector for each version of RLS
-	DissectorTable.new("rls", "RLS version", ftypes.UINT32, base.HEX, rlsProtocol)
+-- Create a DissectorTable to register dissector for each version of RLS
+DissectorTable.new("rls", "RLS version", ftypes.UINT32, base.HEX, rlsProtocol)
 
-	-- Preferences
-	rlsProtocol.prefs.udp_port = Pref.uint("RLS UDP port", 4997, "UDP port for RLS")
+-- Preferences
+rlsProtocol.prefs.udp_port = Pref.uint("RLS UDP port", 4997, "UDP port for RLS")
 
-	-- Add version field
-	local fields = rlsProtocol.fields
-	fields.Version = ProtoField.string("rls.version", "Version")
+-- Add version field
+local fields = rlsProtocol.fields
+fields.Version = ProtoField.string("rls.version", "Version")
 
-	function rlsProtocol.dissector(buffer, pinfo, tree)
-		-- Generic check
-		if buffer:len() == 0 then return end
-		if buffer(0, 1):uint() ~= 0x03 then return end
+function rlsProtocol.dissector(buffer, pinfo, tree)
+	-- Generic check
+	if buffer:len() == 0 then return end
+	if buffer(0, 1):uint() ~= 0x03 then return end
 
-		pinfo.cols.protocol = rlsProtocol.name
+	pinfo.cols.protocol = rlsProtocol.name
 
-		local version = buffer(1,2):uint()
-		local subprotocol = DissectorTable.get("rls"):get_dissector(version)
+	local version = buffer(1,2):uint()
+	local subprotocol = DissectorTable.get("rls"):get_dissector(version)
+	if subprotocol == nil then
+		if version > latestVersion then
+			-- fallback to latest version
+			version = latestVersion
+		elseif version < oldestVersion then
+			-- fallback to oldest version
+			version = oldestVersion
+		end
+		subprotocol = DissectorTable.get("rls"):get_dissector(version)
 		if subprotocol == nil then
-			if version > latestVersion then
-				-- fallback to latest version
-				version = latestVersion
-			elseif version < oldestVersion then
-				-- fallback to oldest version
-				version = oldestVersion
-			end
-			subprotocol = DissectorTable.get("rls"):get_dissector(version)
-			if subprotocol == nil then
-				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")
-				pinfo.cols.info = "Unsupported version - Cannot decode"
-				subtree:add(fields.Version, buffer(1, 3), versionNumber)
-				return 4
-			end
+			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")
+			pinfo.cols.info = "Unsupported version - Cannot decode"
+			subtree:add(fields.Version, buffer(1, 3), versionNumber)
+			return 4
 		end
-		subprotocol:call(buffer():tvb(), pinfo, tree)
 	end
+	subprotocol:call(buffer():tvb(), pinfo, tree)
+end
 
+function rlsProtocol.init()
 	-- Export protocol
 	local udp_port = DissectorTable.get("udp.port")
 	udp_port:add(rlsProtocol.prefs.udp_port, rlsProtocol)