protocol5: added making CONNACK packet type

Author: xHasKx

mqtt/protocol5.lua

@@ -476,6 +476,25 @@ local function make_packet_connect(args)
 	return combine(header, variable_header, payload)
 end
 
+-- Create CONNACK packet, DOC: 3.2 CONNACK – Connect acknowledgement
+local function make_packet_connack(args)
+	-- check args
+	assert(type(args.sp) == "boolean", "expecting .sp to be a boolean with Session Present flag")
+	assert(type(args.rc) == "number", "expecting .rc to be a number with Connect Reason Code")
+	-- DOC: 3.2.2 CONNACK Variable Header
+	local props = make_properties(packet_type.CONNACK, args)
+	local variable_header = combine(
+		make_uint8(args.sp and 1 or 0),		-- DOC: 3.2.2.1.1 Session Present
+		make_uint8(args.rc),				-- DOC: 3.2.2.2 Connect Reason Code
+		props								-- DOC: 3.2.2.3 CONNACK Properties
+	)
+	-- DOC: 3.2.3 CONNACK Payload
+	-- DOC: The CONNACK packet has no Payload.
+	-- DOC: 3.2.1 CONNACK Fixed Header
+	local header = make_header(packet_type.CONNACK, 0, variable_header:len())
+	return combine(header, variable_header)
+end
+
 -- Create PUBLISH packet, DOC: 3.3 PUBLISH – Publish message
 local function make_packet_publish(args)
 	-- check args
@@ -717,7 +736,8 @@ function protocol5.make_packet(args)
 	local ptype = args.type
 	if ptype == packet_type.CONNECT then			-- 1
 		return make_packet_connect(args)
-	-- TODO: CONNACK
+	elseif ptype == packet_type.CONNACK then		-- 3
+		return make_packet_connack(args)
 	elseif ptype == packet_type.PUBLISH then		-- 3
 		return make_packet_publish(args)
 	elseif ptype == packet_type.PUBACK then			-- 4

tests/spec/protocol5-make.lua

@@ -191,6 +191,89 @@ describe("MQTT v5.0 protocol: making packets: CONNECT[1]", function()
 	end)
 end)
 
+describe("MQTT v5.0 protocol: making packets: CONNACK[2]", function()
+	local tools = require("mqtt.tools")
+	local extract_hex = require("mqtt.tools").extract_hex
+	local protocol = require("mqtt.protocol")
+	local protocol5 = require("mqtt.protocol5")
+
+	it("CONNACK with minimum params", function()
+		assert.are.equal(
+			extract_hex[[
+				20						-- packet type == 2 (CONNACK), flags == 0
+				03						-- length == 3 bytes
+
+					00					-- Connect Acknowledge Flags, sp=false
+					00					-- Connect Reason Code == 0
+					00					-- no props
+			]],
+			tools.hex(tostring(protocol5.make_packet{
+				type = protocol.packet_type.CONNACK,
+				sp = false, rc = 0,
+			}))
+		)
+	end)
+
+	it("CONNACK with flags, rc, and full properties", function()
+		assert.are.equal(
+			extract_hex[[
+				20					-- packet type == 2 (CONNACK), flags == 0
+				75					-- variable length == 117 bytes
+
+					01				-- Connect Acknowledge Flags, sp=true
+					82				-- Connect Reason Code == 0x82
+					72				-- properties length
+
+					11 00000E10		-- property 0x11 == 3600, -- DOC: 3.2.2.3.2 Session Expiry Interval
+					12 0005 736C617665	-- property 0x12 == "slave", -- DOC: 3.2.2.3.7 Assigned Client Identifier
+					13 0078			-- property 0x13 == 120, -- DOC: 3.2.2.3.14 Server Keep Alive
+					15 0005 6775657373	-- property 0x15 == "guess", -- DOC: 3.2.2.3.17 Authentication Method
+					16 0002 3130		-- property 0x16 == "10", -- DOC: 3.2.2.3.18 Authentication Data
+					1A 0005 686572652F	-- property 0x1A == "here/", -- DOC: 3.2.2.3.15 Response Information
+					1C 000D 736565202F6465762F6E756C6C	-- property 0x1C == "see /dev/null", -- DOC: 3.2.2.3.16 Server Reference
+					1F 0007 70726F63656564	-- property 0x1F == "proceed", -- DOC: 3.2.2.3.9 Reason String
+					21 1234			-- property 0x21 == 0x1234, -- DOC: 3.2.2.3.3 Receive Maximum
+					22 4321			-- property 0x22 == 0x4321, -- DOC: 3.2.2.3.8 Topic Alias Maximum
+					24 01			-- property 0x24 == 1, -- DOC: 3.2.2.3.4 Maximum QoS
+					25 01			-- property 0x25 == 1, -- DOC: 3.2.2.3.5 Retain Available
+					27 00004567		-- property 0x27 == 0x4567, -- DOC: 3.2.2.3.6 Maximum Packet Size
+					28 01			-- property 0x28 == 1, -- DOC: 3.2.2.3.11 Wildcard Subscription Available
+					29 00			-- property 0x29 == 0, -- DOC: 3.2.2.3.12 Subscription Identifiers Available
+					2A 01			-- property 0x2A == 1, -- DOC: 3.2.2.3.13 Shared Subscription Available
+					26 0005 68656C6C6F 0005 776F726C64	-- property 0x26 (user) == ("hello", "world")  -- DOC: 3.2.2.3.10 User Property
+					26 0005 68656C6C6F 0005 616761696E	-- property 0x26 (user) == ("hello", "again")  -- DOC: 3.2.2.3.10 User Property
+			]],
+			tools.hex(tostring(protocol5.make_packet{
+				type = protocol.packet_type.CONNACK,
+				sp = true, rc = 0x82,
+				properties={
+					session_expiry_interval = 3600,
+					receive_maximum = 0x1234,
+					maximum_qos = 1,
+					retain_available = 1,
+					maximum_packet_size = 0x4567,
+					assigned_client_identifier = "slave",
+					topic_alias_maximum = 0x4321,
+					reason_string = "proceed",
+					wildcard_subscription_available = 1,
+					subscription_identifiers_available = 0,
+					shared_subscription_available = 1,
+					server_keep_alive = 120,
+					response_information = "here/",
+					server_reference = "see /dev/null",
+					authentication_method = "guess",
+					authentication_data = "10",
+				},
+				user_properties={
+					hello = "again", -- NOTE: that key+value pair is equivalent of {"hello", "again"} below, thus that pair will be skipped
+					{"hello", "world"},
+					{"hello", "again"},
+				},
+			}))
+		)
+	end)
+end)
+
 describe("MQTT v5.0 protocol: making packets: PUBLISH[3]", function()
 	local tools = require("mqtt.tools")
 	local extract_hex = require("mqtt.tools").extract_hex