From a508428df8af14437f1a4766ec68294d1d736915 Mon Sep 17 00:00:00 2001 From: Ingela Anderton Andin Date: Thu, 23 Aug 2018 14:29:36 +0200 Subject: ssl: Improve close handling We want to make sure that the sender process that may get stuck in prim_inet:send will die if the tls_connection process is terminated. And we also like to make sure that it terminates as gracefully as possible. So when the tls_connection process dies it spawns a killer process that will brutaly kill the sender if it is unresponsive and does not terminate due to its monitor of the tls_connetion process triggering. When the sender process also acts as distribution controller it may also have other processess that it is linked with that it should bring down or that could bring the connection down. --- lib/ssl/src/tls_connection.erl | 44 +++++++++++++++++++++++------------------- 1 file changed, 24 insertions(+), 20 deletions(-) (limited to 'lib/ssl/src/tls_connection.erl') diff --git a/lib/ssl/src/tls_connection.erl b/lib/ssl/src/tls_connection.erl index 8277569281..6c7511d2b3 100644 --- a/lib/ssl/src/tls_connection.erl +++ b/lib/ssl/src/tls_connection.erl @@ -65,7 +65,7 @@ %% gen_statem state functions -export([init/3, error/3, downgrade/3, %% Initiation and take down states hello/3, user_hello/3, certify/3, cipher/3, abbreviated/3, %% Handshake states - connection/3, death_row/3]). + connection/3]). %% gen_statem callbacks -export([callback_mode/0, terminate/3, code_change/4, format_status/2]). @@ -135,7 +135,7 @@ init([Role, Sender, Host, Port, Socket, {SslOpts, _, _} = Options, User, CbInfo gen_statem:enter_loop(?MODULE, [], error, EState) end. -pids(#state{protocol_specific = #{sender := {_, Sender}}}) -> +pids(#state{protocol_specific = #{sender := Sender}}) -> [self(), Sender]. %%==================================================================== @@ -307,7 +307,7 @@ queue_change_cipher(Msg, #state{negotiated_version = Version, State0#state{connection_states = ConnectionStates, flight_buffer = Flight0 ++ [BinChangeCipher]}. -reinit(#state{protocol_specific = #{sender := {_,Sender}}, +reinit(#state{protocol_specific = #{sender := Sender}, negotiated_version = Version, connection_states = #{current_write := Write}} = State) -> tls_sender:update_connection_state(Sender, Write, Version), @@ -353,7 +353,7 @@ send_alert(Alert, #state{negotiated_version = Version, Connection:send(Transport, Socket, BinMsg), StateData0#state{connection_states = ConnectionStates}. -send_alert_in_connection(Alert, #state{protocol_specific = #{sender := {_, Sender}}}) -> +send_alert_in_connection(Alert, #state{protocol_specific = #{sender := Sender}}) -> tls_sender:send_alert(Sender, Alert). %% User closes or recursive call! @@ -597,7 +597,7 @@ connection(internal, #hello_request{}, connection(internal, #client_hello{} = Hello, #state{role = server, allow_renegotiate = true, connection_states = CS, %%protocol_cb = Connection, - protocol_specific = #{sender := {_, Sender}} + protocol_specific = #{sender := Sender} } = State0) -> %% Mitigate Computational DoS attack %% http://www.educatedguesswork.org/2011/10/ssltls_and_computational_dos.html @@ -621,13 +621,6 @@ connection(internal, #client_hello{}, connection(Type, Event, State) -> ssl_connection:?FUNCTION_NAME(Type, Event, State, ?MODULE). -%%-------------------------------------------------------------------- --spec death_row(gen_statem:event_type(), term(), #state{}) -> - gen_statem:state_function_result(). -%%-------------------------------------------------------------------- -death_row(Type, Event, State) -> - ssl_connection:death_row(Type, Event, State, ?MODULE). - %%-------------------------------------------------------------------- -spec downgrade(gen_statem:event_type(), term(), #state{}) -> gen_statem:state_function_result(). @@ -642,6 +635,7 @@ callback_mode() -> state_functions. terminate(Reason, StateName, State) -> + ensure_sender_terminate(Reason, State), catch ssl_connection:terminate(Reason, StateName, State). format_status(Type, Data) -> @@ -668,7 +662,6 @@ initial_state(Role, Sender, Host, Port, Socket, {SSLOptions, SocketOptions, Trac end, UserMonitor = erlang:monitor(process, User), - SendMonitor = erlang:monitor(process, Sender), #state{socket_options = SocketOptions, ssl_options = SSLOptions, @@ -693,7 +686,7 @@ initial_state(Role, Sender, Host, Port, Socket, {SSLOptions, SocketOptions, Trac protocol_cb = ?MODULE, tracker = Tracker, flight_buffer = [], - protocol_specific = #{sender => {SendMonitor, Sender}} + protocol_specific = #{sender => Sender} }. erl_dist_data(true) -> @@ -711,7 +704,7 @@ initialize_tls_sender(#state{role = Role, negotiated_version = Version, ssl_options = #ssl_options{renegotiate_at = RenegotiateAt}, connection_states = #{current_write := ConnectionWriteState}, - protocol_specific = #{sender := {_, Sender}}}) -> + protocol_specific = #{sender := Sender}}) -> Init = #{current_write => ConnectionWriteState, role => Role, socket => Socket, @@ -794,11 +787,9 @@ handle_info({CloseTag, Socket}, StateName, %% and then receive the final message. next_event(StateName, no_record, State) end; -handle_info({'DOWN', Mon, _, _, _}, _, #state{ssl_options = #ssl_options{erl_dist = true}, - protocol_specific = #{sender:= {Mon, _}}} = State) -> - ssl_connection:death_row(State, disconnect); -handle_info({'DOWN', Mon, _, _, Reason}, _, #state{protocol_specific = #{sender:= {Mon, _}}} = State) -> - {stop, {shudown, sender_died, Reason}, State}; +handle_info({'EXIT', Pid, Reason}, _, + #state{protocol_specific = Pid} = State) -> + {stop, {shutdown, sender_died, Reason}, State}; handle_info(Msg, StateName, State) -> ssl_connection:StateName(info, Msg, State, ?MODULE). @@ -888,3 +879,16 @@ assert_buffer_sanity(Bin, _) -> throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, malformed_handshake_data)) end. + +ensure_sender_terminate(downgrade, _) -> + ok; %% Do not terminate sender during downgrade phase +ensure_sender_terminate(_, #state{protocol_specific = #{sender := Sender}}) -> + %% Make sure TLS sender dies when connection process is terminated normally + %% This is needed if the tls_sender is blocked in prim_inet:send + Kill = fun() -> + receive + after 5000 -> + catch (exit(Sender, kill)) + end + end, + spawn(Kill). -- cgit v1.2.3