The broker now sends the receive-maximum property for MQTT v5 CONNACKs.

ChangeLog.txt

@@ -55,6 +55,7 @@ Broker:
 - Document that X509_free() must be called after using
   mosquitto_client_certificate(). Closes #1842.
 - Add "deny" acl type. Closes #1611.
+- The broker now sends the receive-maximum property for MQTT v5 CONNACKs.
 
 Client library:
 - Client no longer generates random client ids for v3.1.1 clients, these are

src/send_connack.c

@@ -51,13 +51,20 @@ int send__connack(struct mosquitto_db *db, struct mosquitto *context, uint8_t ac
 				return rc;
 			}
 		}
-		if(db->config->max_packet_size > 0){
+		if(reason_code < 128 && db->config->max_packet_size > 0){
 			rc = mosquitto_property_add_int32(&connack_props, MQTT_PROP_MAXIMUM_PACKET_SIZE, db->config->max_packet_size);
 			if(rc){
 				mosquitto_property_free_all(&connack_props);
 				return rc;
 			}
 		}
+		if(reason_code < 128 && db->config->max_inflight_messages > 0){
+			rc = mosquitto_property_add_int16(&connack_props, MQTT_PROP_RECEIVE_MAXIMUM, db->config->max_inflight_messages);
+			if(rc){
+				mosquitto_property_free_all(&connack_props);
+				return rc;
+			}
+		}
 
 		remaining_length += property__get_remaining_length(connack_props);
 	}

test/broker/01-connect-zero-length-id.py

@@ -41,7 +41,7 @@ def do_test(per_listener, proto_ver, clean_start, allow_zero, client_port, expec
             # Remove the "xxxx" part - this means the front part of the packet
             # is correct (so remaining length etc. is correct), but we don't
             # need to match against the random id.
-            connack_packet = connack_packet[:-36]
+            connack_packet = connack_packet[:-39]
 
     broker = mosq_test.start_broker(filename=os.path.basename(__file__), port=port1, use_conf=True)
 

test/broker/03-publish-qos1-max-inflight.py

@@ -8,17 +8,20 @@ from mosq_test_helper import *
 def write_config(filename, port):
     with open(filename, 'w') as f:
         f.write("port %d\n" % (port))
+        f.write("allow_anonymous true\n")
         f.write("max_inflight_messages 1\n")
 
 def do_test(proto_ver):
     rc = 1
     keepalive = 60
     connect_packet = mosq_test.gen_connect("pub-qos1-test", keepalive=keepalive, proto_ver=proto_ver)
-    connack_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+    properties = mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_TOPIC_ALIAS_MAXIMUM, 10) \
+        + mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_RECEIVE_MAXIMUM, 1)
+    connack_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver, properties=properties, property_helper=False)
 
     mid = 311
     publish_packet = mosq_test.gen_publish("pub/qos1/test", qos=1, mid=mid, payload="message", proto_ver=proto_ver)
-    puback_packet = mosq_test.gen_puback(mid, proto_ver=proto_ver)
+    puback_packet = mosq_test.gen_puback(mid, reason_code=mqtt5_rc.MQTT_RC_NO_MATCHING_SUBSCRIBERS, proto_ver=proto_ver)
 
     port = mosq_test.get_port()
     conf_file = os.path.basename(__file__).replace('.py', '.conf')
@@ -47,5 +50,5 @@ def do_test(proto_ver):
 
 do_test(proto_ver=4)
 do_test(proto_ver=5)
-exit(rc)
+exit(0)
 

test/broker/03-publish-qos2-max-inflight.py

@@ -20,7 +20,9 @@ def do_test(proto_ver):
     rc = 1
     keepalive = 60
     connect_packet = mosq_test.gen_connect("pub-qos2-test", keepalive=keepalive, proto_ver=proto_ver)
-    connack_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+    properties = mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_TOPIC_ALIAS_MAXIMUM, 10) \
+        + mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_RECEIVE_MAXIMUM, 1)
+    connack_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver, properties=properties, property_helper=False)
 
     mid = 312
     publish_packet = mosq_test.gen_publish("pub/qos2/test", qos=2, mid=mid, payload="message", proto_ver=proto_ver)

test/broker/test.py

@@ -73,6 +73,7 @@ tests = [
     (1, './03-publish-dollar.py'),
     (1, './03-publish-invalid-utf8.py'),
     (1, './03-publish-long-topic.py'),
+    (1, './03-publish-qos1-max-inflight.py'),
     (1, './03-publish-qos1-no-subscribers-v5.py'),
     (1, './03-publish-qos1-retain-disabled.py'),
     (1, './03-publish-qos1.py'),

test/lib/03-publish-c2b-qos1-receive-maximum.py

@@ -12,7 +12,7 @@ keepalive = 60
 connect_packet = mosq_test.gen_connect("publish-qos1-test", keepalive=keepalive, proto_ver=5)
 
 props = mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_RECEIVE_MAXIMUM, 3)
-connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5, properties=props)
+connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5, properties=props, property_helper=False)
 
 disconnect_packet = mosq_test.gen_disconnect(proto_ver=5)
 

test/lib/03-publish-c2b-qos2-pubrec-error.py

@@ -13,7 +13,7 @@ keepalive = 60
 connect_packet = mosq_test.gen_connect("publish-qos2-test", keepalive=keepalive, proto_ver=5)
 
 props = mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_RECEIVE_MAXIMUM, 1)
-connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5, properties=props)
+connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5, properties=props, property_helper=False)
 
 disconnect_packet = mosq_test.gen_disconnect(proto_ver=5)
 

test/lib/03-publish-c2b-qos2-receive-maximum-1.py

@@ -12,7 +12,7 @@ keepalive = 60
 connect_packet = mosq_test.gen_connect("publish-qos2-test", keepalive=keepalive, proto_ver=5)
 
 props = mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_RECEIVE_MAXIMUM, 1)
-connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5, properties=props)
+connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5, properties=props, property_helper=False)
 
 disconnect_packet = mosq_test.gen_disconnect(proto_ver=5)
 

test/lib/03-publish-c2b-qos2-receive-maximum-2.py

@@ -12,7 +12,7 @@ keepalive = 60
 connect_packet = mosq_test.gen_connect("publish-qos2-test", keepalive=keepalive, proto_ver=5)
 
 props = mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_RECEIVE_MAXIMUM, 2)
-connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5, properties=props)
+connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5, properties=props, property_helper=False)
 
 disconnect_packet = mosq_test.gen_disconnect(proto_ver=5)
 

test/mosq_test.py

@@ -444,12 +444,14 @@ def gen_connect(client_id, clean_session=True, keepalive=60, username=None, pass
             packet = packet + struct.pack("!H"+str(len(password))+"s", len(password), password)
     return packet
 
-def gen_connack(flags=0, rc=0, proto_ver=4, properties=b""):
+def gen_connack(flags=0, rc=0, proto_ver=4, properties=b"", property_helper=True):
     if proto_ver == 5:
-        if properties is not None:
+        if property_helper == True:
-            properties = mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_TOPIC_ALIAS_MAXIMUM, 10) + properties
+            if properties is not None:
-        else:
+                properties = mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_TOPIC_ALIAS_MAXIMUM, 10) \
-            properties = b""
+                    + properties + mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_RECEIVE_MAXIMUM, 20)
+            else:
+                properties = b""
         properties = mqtt5_props.prop_finalise(properties)
 
         packet = struct.pack('!BBBB', 32, 2+len(properties), flags, rc) + properties