From 6a4d823b2435652bf18992f488bf8b67262475f0 Mon Sep 17 00:00:00 2001
From: JianBo He <heeejianbo@gmail.com>
Date: Fri, 25 Mar 2022 17:31:31 +0800
Subject: [PATCH 1/2] fix(sys): compatible with binary type protocol

---
 apps/emqx/src/emqx_sys.erl | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/apps/emqx/src/emqx_sys.erl b/apps/emqx/src/emqx_sys.erl
index 9fa116313..d3bf72fc3 100644
--- a/apps/emqx/src/emqx_sys.erl
+++ b/apps/emqx/src/emqx_sys.erl
@@ -365,10 +365,13 @@ event_topic(Event, #{clientid := ClientId, protocol := GwName}) ->
         [
             systop("gateway"),
             "/",
-            atom_to_binary(GwName),
+            bin(GwName),
             "/clients/",
             ClientId,
             "/",
-            atom_to_binary(Event)
+            bin(Event)
         ]
     ).
+
+bin(A) when is_atom(A) -> atom_to_binary(A);
+bin(B) when is_binary(B) -> B.

From 84313874085d125594158b4650025bfc5ea93954 Mon Sep 17 00:00:00 2001
From: JianBo He <heeejianbo@gmail.com>
Date: Fri, 25 Mar 2022 18:15:27 +0800
Subject: [PATCH 2/2] chore(exproto): set proto_name default to exproto

---
 .../emqx_gateway/src/exproto/emqx_exproto_channel.erl | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/apps/emqx_gateway/src/exproto/emqx_exproto_channel.erl b/apps/emqx_gateway/src/exproto/emqx_exproto_channel.erl
index 137682ff8..a5c889516 100644
--- a/apps/emqx_gateway/src/exproto/emqx_exproto_channel.erl
+++ b/apps/emqx_gateway/src/exproto/emqx_exproto_channel.erl
@@ -610,7 +610,7 @@ enrich_conninfo(InClientInfo, ConnInfo) ->
 enrich_clientinfo(InClientInfo = #{proto_name := ProtoName}, ClientInfo) ->
     Ks = [clientid, username, mountpoint],
     NClientInfo = maps:merge(ClientInfo, maps:with(Ks, InClientInfo)),
-    NClientInfo#{protocol => ProtoName}.
+    NClientInfo#{protocol => proto_name_to_protocol(ProtoName)}.
 
 default_conninfo(ConnInfo) ->
     ConnInfo#{clean_start => true,
@@ -619,6 +619,8 @@ default_conninfo(ConnInfo) ->
               conn_mod => undefined,
               conn_props => #{},
               connected => true,
+              proto_name => <<"exproto">>,
+              proto_ver => <<"1.0">>,
               connected_at => erlang:system_time(millisecond),
               keepalive => 0,
               receive_maximum => 0,
@@ -627,7 +629,7 @@ default_conninfo(ConnInfo) ->
 default_clientinfo(#{peername := {PeerHost, _},
                      sockname := {_, SockPort}}) ->
     #{zone         => default,
-      protocol     => undefined,
+      protocol     => exproto,
       peerhost     => PeerHost,
       sockport     => SockPort,
       clientid     => undefined,
@@ -642,3 +644,8 @@ stringfy(Reason) ->
 fmt_from(undefined) -> <<>>;
 fmt_from(Bin) when is_binary(Bin) -> Bin;
 fmt_from(T) -> stringfy(T).
+
+proto_name_to_protocol(<<>>) ->
+    exproto;
+proto_name_to_protocol(ProtoName) when is_binary(ProtoName) ->
+    binary_to_atom(ProtoName).