From 3530ed66d508897a04f7843df106dd02436f2d35 Mon Sep 17 00:00:00 2001
From: Serge Tupchii <serge.tupchii@protonmail.com>
Date: Tue, 28 Nov 2023 19:28:53 +0200
Subject: [PATCH] fix(emqx_gateway_coap): take subscribe options from uri_query

Closes #12031
---
 .../src/emqx_coap_pubsub_handler.erl          | 10 +++--
 .../test/emqx_coap_SUITE.erl                  | 39 +++++++++++++++++++
 changes/ce/fix-12048.en.md                    |  1 +
 3 files changed, 46 insertions(+), 4 deletions(-)
 create mode 100644 changes/ce/fix-12048.en.md

diff --git a/apps/emqx_gateway_coap/src/emqx_coap_pubsub_handler.erl b/apps/emqx_gateway_coap/src/emqx_coap_pubsub_handler.erl
index 3070ea891..cbb5d7c94 100644
--- a/apps/emqx_gateway_coap/src/emqx_coap_pubsub_handler.erl
+++ b/apps/emqx_gateway_coap/src/emqx_coap_pubsub_handler.erl
@@ -74,14 +74,16 @@ check_topic([]) ->
 check_topic(Path) ->
     {ok, emqx_http_lib:uri_decode(iolist_to_binary(lists:join(<<"/">>, Path)))}.
 
-get_sub_opts(#coap_message{options = Opts} = Msg) ->
-    SubOpts = maps:fold(fun parse_sub_opts/3, #{}, Opts),
+get_sub_opts(Msg) ->
+    SubOpts = maps:fold(
+        fun parse_sub_opts/3, #{}, emqx_coap_message:get_option(uri_query, Msg, #{})
+    ),
     case SubOpts of
         #{qos := _} ->
-            maps:merge(SubOpts, ?SUBOPTS);
+            maps:merge(?SUBOPTS, SubOpts);
         _ ->
             CfgType = emqx_conf:get([gateway, coap, subscribe_qos], ?QOS_0),
-            maps:merge(SubOpts, ?SUBOPTS#{qos => type_to_qos(CfgType, Msg)})
+            maps:merge(?SUBOPTS#{qos => type_to_qos(CfgType, Msg)}, SubOpts)
     end.
 
 parse_sub_opts(<<"qos">>, V, Opts) ->
diff --git a/apps/emqx_gateway_coap/test/emqx_coap_SUITE.erl b/apps/emqx_gateway_coap/test/emqx_coap_SUITE.erl
index c066b84ff..8f93164b5 100644
--- a/apps/emqx_gateway_coap/test/emqx_coap_SUITE.erl
+++ b/apps/emqx_gateway_coap/test/emqx_coap_SUITE.erl
@@ -345,6 +345,45 @@ t_subscribe(_) ->
         Topics
     ).
 
+t_subscribe_with_qos_opt(_) ->
+    Topics = [
+        {<<"abc">>, 0},
+        {<<"/abc">>, 1},
+        {<<"abc/d">>, 2}
+    ],
+    Fun = fun({Topic, Qos}, Channel, Token) ->
+        Payload = <<"123">>,
+        URI = pubsub_uri(binary_to_list(Topic), Token) ++ "&qos=" ++ integer_to_list(Qos),
+        Req = make_req(get, Payload, [{observe, 0}]),
+        {ok, content, _} = do_request(Channel, URI, Req),
+        ?LOGT("observer topic:~ts~n", [Topic]),
+
+        %% ensure subscribe succeed
+        timer:sleep(100),
+        [SubPid] = emqx:subscribers(Topic),
+        ?assert(is_pid(SubPid)),
+        ?assertEqual(Qos, maps:get(qos, emqx_broker:get_subopts(SubPid, Topic))),
+        %% publish a message
+        emqx:publish(emqx_message:make(Topic, Payload)),
+        {ok, content, Notify} = with_response(Channel),
+        ?LOGT("observer get Notif=~p", [Notify]),
+
+        #coap_content{payload = PayloadRecv} = Notify,
+
+        ?assertEqual(Payload, PayloadRecv)
+    end,
+
+    with_connection(Topics, Fun),
+
+    %% subscription removed if coap client disconnected
+    timer:sleep(100),
+    lists:foreach(
+        fun({Topic, _Qos}) ->
+            ?assertEqual([], emqx:subscribers(Topic))
+        end,
+        Topics
+    ).
+
 t_un_subscribe(_) ->
     %% can unsubscribe to a normal topic
     Topics = [
diff --git a/changes/ce/fix-12048.en.md b/changes/ce/fix-12048.en.md
new file mode 100644
index 000000000..cecd62222
--- /dev/null
+++ b/changes/ce/fix-12048.en.md
@@ -0,0 +1 @@
+Fix COAP gateway bug that caused it to ignore subscription options.