Allow disabling keep-alive for HTTP/1.0 connections

doc/src/manual/cowboy_http.asciidoc

@@ -19,6 +19,7 @@ as a Ranch protocol.
 opts() :: #{
     connection_type         => worker | supervisor,
     env                     => cowboy_middleware:env(),
+    http10_keepalive        => boolean(),
     idle_timeout            => timeout(),
     inactivity_timeout      => timeout(),
     linger_timeout          => timeout(),
@@ -58,6 +59,10 @@ env (#{})::
 
 Middleware environment.
 
+http10_keepalive (true)::
+
+Whether keep-alive is enabled for HTTP/1.0 connections.
+
 idle_timeout (60000)::
 
 Time in ms with no data received before Cowboy closes the connection.

src/cowboy_http.erl

@@ -28,6 +28,7 @@
 	compress_threshold => non_neg_integer(),
 	connection_type => worker | supervisor,
 	env => cowboy_middleware:env(),
+	http10_keepalive => boolean(),
 	idle_timeout => timeout(),
 	inactivity_timeout => timeout(),
 	linger_timeout => timeout(),
@@ -1233,7 +1234,8 @@ stream_call_terminate(StreamID, Reason, StreamState, #state{opts=Opts}) ->
 			Class, Exception, erlang:get_stacktrace()), Opts)
 	end.
 
-%% @todo max_reqs also
+maybe_req_close(#state{opts=#{http10_keepalive := false}}, _, 'HTTP/1.0') ->
+	close;
 maybe_req_close(_, #{<<"connection">> := Conn}, 'HTTP/1.0') ->
 	Conns = cow_http_hd:parse_connection(Conn),
 	case lists:member(<<"keep-alive">>, Conns) of
@@ -1247,7 +1249,7 @@ maybe_req_close(_, #{<<"connection">> := Conn}, 'HTTP/1.1') ->
 		true -> close;
 		false -> keepalive
 	end;
-maybe_req_close(_State, _, _) ->
+maybe_req_close(_, _, _) ->
 	keepalive.
 
 connection(State=#state{last_streamid=StreamID}, Headers=#{<<"connection">> := Conn}, StreamID, _) ->

test/http_SUITE.erl

@@ -21,6 +21,9 @@
 -import(ct_helper, [get_remote_pid_tcp/1]).
 -import(ct_helper, [name/0]).
 -import(cowboy_test, [gun_open/1]).
+-import(cowboy_test, [raw_open/1]).
+-import(cowboy_test, [raw_send/2]).
+-import(cowboy_test, [raw_recv_head/1]).
 
 all() -> [{group, clear}].
 
@@ -33,6 +36,31 @@ init_routes(_) -> [
 	]}
 ].
 
+http10_keepalive_false(Config) ->
+	doc("Confirm the option {http10_keepalive, false} disables keep-alive "
+		"completely for HTTP/1.0 connections."),
+	{ok, _} = cowboy:start_clear(name(), [{port, 0}], #{
+		env => #{dispatch => cowboy_router:compile(init_routes(Config))},
+		http10_keepalive => false
+	}),
+	Port = ranch:get_port(name()),
+	Keepalive = "GET / HTTP/1.0\r\nhost: localhost\r\nConnection: keep-alive\r\n\r\n",
+	Client = raw_open([{type, tcp}, {port, Port}, {opts, []}|Config]),
+	ok = raw_send(Client, Keepalive),
+	_ = case catch raw_recv_head(Client) of
+		{'EXIT', _} -> error(closed);
+		Data ->
+			%% Cowboy always advertises itself as HTTP/1.1.
+			{'HTTP/1.1', 200, _, Rest} = cow_http:parse_status_line(Data),
+			{Headers, _} = cow_http:parse_headers(Rest),
+			{_, <<"close">>} = lists:keyfind(<<"connection">>, 1, Headers)
+	end,
+	ok = raw_send(Client, Keepalive),
+	case catch raw_recv_head(Client) of
+		{'EXIT', _} -> closed;
+		_ -> error(not_closed)
+	end.
+
 idle_timeout_infinity(Config) ->
 	doc("Ensure the idle_timeout option accepts the infinity value."),
 	{ok, _} = cowboy:start_clear(name(), [{port, 0}], #{