Check topic level for publish packet and optimize the handling of rap

src/emqx_channel.erl

@@ -1064,11 +1064,11 @@ check_pub_alias(_Packet, _Channel) -> ok.
 
 %% Check Pub Caps
 check_pub_caps(#mqtt_packet{header = #mqtt_packet_header{qos = QoS,
-                                                         retain = Retain
-                                                        }
+                                                         retain = Retain},
+                            variable = #mqtt_packet_publish{topic_name = Topic}
                            },
                #channel{clientinfo = #{zone := Zone}}) ->
-    emqx_mqtt_caps:check_pub(Zone, #{qos => QoS, retain => Retain}).
+    emqx_mqtt_caps:check_pub(Zone, #{qos => QoS, retain => Retain, topic => Topic}).
 
 %% Check Sub
 check_subscribe(TopicFilter, SubOpts, Channel) ->

src/emqx_mqtt_caps.erl

@@ -46,7 +46,7 @@
 
 -define(UNLIMITED, 0).
 
--define(PUBCAP_KEYS, [max_topic_alias,
+-define(PUBCAP_KEYS, [max_topic_levels,
                       max_qos_allowed,
                       retain_available
                      ]).
@@ -73,8 +73,16 @@
                   retain => boolean()})
       -> ok_or_error(emqx_types:reason_code())).
 check_pub(Zone, Flags) when is_map(Flags) ->
-    do_check_pub(Flags, get_caps(Zone, publish)).
+    do_check_pub(case maps:take(topic, Flags) of
+                     {Topic, Flags1} ->
+                         Flags1#{topic_levels => emqx_topic:levels(Topic)};
+                     error ->
+                         Flags
+                 end, get_caps(Zone, publish)).
 
+do_check_pub(#{topic_levels := Levels}, #{max_topic_levels := Limit})
+  when Limit > 0, Levels > Limit ->
+    {error, ?RC_TOPIC_NAME_INVALID};
 do_check_pub(#{qos := QoS}, #{max_qos_allowed := MaxQoS})
   when QoS > MaxQoS ->
     {error, ?RC_QOS_NOT_SUPPORTED};

src/emqx_session.erl

@@ -539,12 +539,12 @@ enrich_subopt([{qos, SubQoS}|Opts], Msg = #message{qos = PubQoS},
 enrich_subopt([{qos, SubQoS}|Opts], Msg = #message{qos = PubQoS},
               Session = #session{upgrade_qos= false}) ->
     enrich_subopt(Opts, Msg#message{qos = min(SubQoS, PubQoS)}, Session);
-enrich_subopt([{rap, 1}|Opts], Msg, Session) ->
-    enrich_subopt(Opts, Msg, Session);
-enrich_subopt([{rap, 0}|Opts], Msg = #message{headers = #{retained := true}}, Session) ->
-    enrich_subopt(Opts, Msg, Session);
+enrich_subopt([{rap, _}|Opts], Msg = #message{headers = #{retained := true}}, Session) ->
+    enrich_subopt(Opts, emqx_message:set_flag(retain, true, Msg), Session);
 enrich_subopt([{rap, 0}|Opts], Msg, Session) ->
     enrich_subopt(Opts, emqx_message:set_flag(retain, false, Msg), Session);
+enrich_subopt([{rap, 1}|Opts], Msg, Session) ->
+    enrich_subopt(Opts, Msg, Session);
 enrich_subopt([{subid, SubId}|Opts], Msg, Session) ->
     Msg1 = emqx_message:set_header('Subscription-Identifier', SubId, Msg),
     enrich_subopt(Opts, Msg1, Session).