From cb8a3725b4cd1cef2b8091f252dba711d69c3429 Mon Sep 17 00:00:00 2001
From: JianBo He <heeejianbo@gmail.com>
Date: Mon, 20 Dec 2021 14:22:06 +0800
Subject: [PATCH 1/2] fix: disconnect the client due to exceed receive-maximum
 packets

As described in the 5.0 specification, we should disconnect clients that
exceed the receive-maximum limit.

> If it receives more than Receive Maximum QoS 1 and QoS 2 PUBLISH packets
where it has not sent a PUBACK or PUBCOMP in response, **the Server uses a
DISCONNECT packet with Reason Code 0x9**

fix: #6447
---
 src/emqx_channel.erl        | 2 +-
 test/emqx_channel_SUITE.erl | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/emqx_channel.erl b/src/emqx_channel.erl
index f33b3b337..2774ac264 100644
--- a/src/emqx_channel.erl
+++ b/src/emqx_channel.erl
@@ -599,7 +599,7 @@ do_publish(PacketId, Msg = #message{qos = ?QOS_2},
             ?LOG(warning, "Dropped the qos2 packet ~w "
                  "due to awaiting_rel is full.", [PacketId]),
             ok = emqx_metrics:inc('packets.publish.dropped'),
-            handle_out(pubrec, {PacketId, RC}, Channel)
+            handle_out(disconnect, RC, Channel)
     end.
 
 ensure_quota(_, Channel = #channel{quota = undefined}) ->
diff --git a/test/emqx_channel_SUITE.erl b/test/emqx_channel_SUITE.erl
index 3249eb991..97b77ca88 100644
--- a/test/emqx_channel_SUITE.erl
+++ b/test/emqx_channel_SUITE.erl
@@ -209,7 +209,8 @@ t_handle_in_qos2_publish_with_error_return(_) ->
     {ok, ?PUBREC_PACKET(2, ?RC_NO_MATCHING_SUBSCRIBERS), Channel1} =
         emqx_channel:handle_in(Publish2, Channel),
     Publish3 = ?PUBLISH_PACKET(?QOS_2, <<"topic">>, 3, <<"payload">>),
-    {ok, ?PUBREC_PACKET(3, ?RC_RECEIVE_MAXIMUM_EXCEEDED), Channel1} =
+    {ok, [{outgoing, ?DISCONNECT_PACKET(?RC_RECEIVE_MAXIMUM_EXCEEDED)},
+          {close, receive_maximum_exceeded}], Channel1} =
         emqx_channel:handle_in(Publish3, Channel1).
 
 t_handle_in_puback_ok(_) ->

From 02dc216173b024eb616ac83fa7d80167cdb3f027 Mon Sep 17 00:00:00 2001
From: JianBo He <heeejianbo@gmail.com>
Date: Mon, 20 Dec 2021 14:34:40 +0800
Subject: [PATCH 2/2] chore: update appup.src

---
 src/emqx.app.src   | 2 +-
 src/emqx.appup.src | 8 ++++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/emqx.app.src b/src/emqx.app.src
index b0e1664cc..1119deccb 100644
--- a/src/emqx.app.src
+++ b/src/emqx.app.src
@@ -1,7 +1,7 @@
 {application, emqx,
  [{id, "emqx"},
   {description, "EMQ X"},
-  {vsn, "4.3.12"}, % strict semver, bump manually!
+  {vsn, "4.3.13"}, % strict semver, bump manually!
   {modules, []},
   {registered, []},
   {applications, [kernel,stdlib,gproc,gen_rpc,esockd,cowboy,sasl,os_mon]},
diff --git a/src/emqx.appup.src b/src/emqx.appup.src
index 456f89e6c..c4885b7b1 100644
--- a/src/emqx.appup.src
+++ b/src/emqx.appup.src
@@ -1,6 +1,8 @@
 %% -*- mode: erlang -*-
 {VSN,
-  [{"4.3.11",
+  [{"4.3.12",
+    [{load_module,emqx_channel,brutal_purge,soft_purge,[]}]},
+   {"4.3.11",
     [{load_module,emqx_connection,brutal_purge,soft_purge,[]},
      {load_module,emqx_channel,brutal_purge,soft_purge,[]},
      {load_module,emqx_vm,brutal_purge,soft_purge,[]},
@@ -196,7 +198,9 @@
      {load_module,emqx_rpc,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]}]},
    {<<".*">>,[]}],
-  [{"4.3.11",
+  [{"4.3.12",
+    [{load_module,emqx_channel,brutal_purge,soft_purge,[]}]},
+   {"4.3.11",
     [{load_module,emqx_connection,brutal_purge,soft_purge,[]},
      {load_module,emqx_channel,brutal_purge,soft_purge,[]},
      {load_module,emqx_vm,brutal_purge,soft_purge,[]},