Reject Websocket frames sent over HTTP

2 files changed, 26 insertions, 0 deletions

diff --git a/src/gun_http.erl b/src/gun_http.erl
index d28600b..29cfa9c 100644
--- a/src/gun_http.erl
+++ b/src/gun_http.erl
@@ -35,6 +35,7 @@
 -export([stream_info/2]).
 -export([down/1]).
 -export([ws_upgrade/11]).
+-export([ws_send/6]).
 
 %% Functions shared with gun_http2 and gun_pool.
 -export([host_header/3]).
@@ -1051,3 +1052,16 @@ ws_handshake_end(Buffer, State=#http_state{streams=[#stream{flow=InitialFlow}|_]
 		handler => Handler,
 		opts => Opts
 	}}, ReplyTo, Buffer}.
+
+%% Reject attempts to send Websocket frames on HTTP.
+%% This can happen either because the user explicitly
+%% called ws_send on an HTTP connection, or because
+%% the connection was dropped and automatically
+%% reconnected. Automatic reconnection doesn't perform
+%% a Websocket upgrade automatically.
+ws_send(_, _, _, ReplyTo, _, EvHandlerState) ->
+	gun:reply(ReplyTo, {gun_error, self(), {badstate,
+		"This connection does not currently accept Websocket frames. "
+		"The Websocket upgrade was not performed. "
+		"This may happen as a result of automatic reconnect."}}),
+	{[], EvHandlerState}.
diff --git a/test/gun_SUITE.erl b/test/gun_SUITE.erl
index 1c9ba23..766b1e7 100644
--- a/test/gun_SUITE.erl
+++ b/test/gun_SUITE.erl
@@ -730,6 +730,18 @@ transform_header_name(_) ->
 	1 = length(HostLines),
 	gun:close(Pid).
 
+ws_send_http(_) ->
+	{ok, ListenSocket} = gen_tcp:listen(0, [binary, {active, false}]),
+	{ok, {_, Port}} = inet:sockname(ListenSocket),
+	{ok, ConnPid} = gun:open("localhost", Port, #{
+		protocols => [http]
+	}),
+	{ok, _ClientSocket} = gen_tcp:accept(ListenSocket, 5000),
+	{ok, http} = gun:await_up(ConnPid),
+	gun:ws_send(ConnPid, make_ref(), ping),
+	{error, {connection_error, {badstate, _}}} = gun:await(ConnPid, undefined),
+	gun:close(ConnPid).
+
 unix_socket_connect(_) ->
 	case os:type() of
 		{win32, _} ->