File 2481-dtls-Use-enter-actions.patch of Package erlang
From 0d4047e02fe2275bdd8a8c940b3c79753e18cba2 Mon Sep 17 00:00:00 2001
From: Ingela Anderton Andin <ingela@erlang.org>
Date: Thu, 1 Jun 2017 23:34:51 +0200
Subject: [PATCH 1/2] dtls: Use enter actions
Using enter actions for retransmission timers makes the code easier to
understand. Previously the retransmission timer was incorrectly started in
the connection state. Using enter actions feels like a cleaner approach
than bloating the state with more flags.
---
lib/ssl/src/dtls_connection.erl | 41 ++++++++++++++++++++++++++++++++---------
1 file changed, 32 insertions(+), 9 deletions(-)
diff --git a/lib/ssl/src/dtls_connection.erl b/lib/ssl/src/dtls_connection.erl
index 2de947d8b..b19f976cd 100644
--- a/lib/ssl/src/dtls_connection.erl
+++ b/lib/ssl/src/dtls_connection.erl
@@ -115,7 +115,7 @@ send_handshake_flight(#state{socket = Socket,
{Encoded, ConnectionStates} =
encode_handshake_flight(lists:reverse(Flight), Version, 1400, Epoch, ConnectionStates0),
send(Transport, Socket, Encoded),
- start_flight(State0#state{connection_states = ConnectionStates});
+ {State0#state{connection_states = ConnectionStates}, []};
send_handshake_flight(#state{socket = Socket,
transport_cb = Transport,
@@ -129,7 +129,7 @@ send_handshake_flight(#state{socket = Socket,
{EncChangeCipher, ConnectionStates} = encode_change_cipher(ChangeCipher, Version, Epoch, ConnectionStates1),
send(Transport, Socket, [HsBefore, EncChangeCipher]),
- start_flight(State0#state{connection_states = ConnectionStates});
+ {State0#state{connection_states = ConnectionStates}, []};
send_handshake_flight(#state{socket = Socket,
transport_cb = Transport,
@@ -145,7 +145,7 @@ send_handshake_flight(#state{socket = Socket,
{HsAfter, ConnectionStates} =
encode_handshake_flight(lists:reverse(Flight1), Version, 1400, Epoch, ConnectionStates2),
send(Transport, Socket, [HsBefore, EncChangeCipher, HsAfter]),
- start_flight(State0#state{connection_states = ConnectionStates});
+ {State0#state{connection_states = ConnectionStates}, []};
send_handshake_flight(#state{socket = Socket,
transport_cb = Transport,
@@ -159,7 +159,7 @@ send_handshake_flight(#state{socket = Socket,
{HsAfter, ConnectionStates} =
encode_handshake_flight(lists:reverse(Flight1), Version, 1400, Epoch, ConnectionStates1),
send(Transport, Socket, [EncChangeCipher, HsAfter]),
- start_flight(State0#state{connection_states = ConnectionStates}).
+ {State0#state{connection_states = ConnectionStates}, []}.
queue_change_cipher(ChangeCipher, #state{flight_buffer = Flight,
connection_states = ConnectionStates0} = State) ->
@@ -235,12 +235,14 @@ init([Role, Host, Port, Socket, Options, User, CbInfo]) ->
end.
callback_mode() ->
- state_functions.
+ [state_functions, state_enter].
%%--------------------------------------------------------------------
%% State functions
%%--------------------------------------------------------------------
+init(enter, _, State) ->
+ {keep_state, State};
init({call, From}, {start, Timeout},
#state{host = Host, port = Port, role = client,
ssl_options = SslOpts,
@@ -282,6 +284,8 @@ init({call, _} = Type, Event, #state{role = server} = State) ->
init(Type, Event, State) ->
ssl_connection:init(Type, Event, State, ?MODULE).
+error(enter, _, State) ->
+ {keep_state, State};
error({call, From}, {start, _Timeout}, {Error, State}) ->
{stop_and_reply, normal, {reply, From, {error, Error}}, State};
error({call, From}, Msg, State) ->
@@ -295,6 +299,11 @@ error(_, _, _) ->
#state{}) ->
gen_statem:state_function_result().
%%--------------------------------------------------------------------
+hello(enter, _, #state{role = server} = State) ->
+ {keep_state, State};
+hello(enter, _, #state{role = client} = State0) ->
+ {State, Actions} = handle_flight_timer(State0),
+ {keep_state, State, Actions};
hello(internal, #client_hello{cookie = <<>>,
client_version = Version} = Hello, #state{role = server,
transport_cb = Transport,
@@ -374,6 +383,9 @@ hello(state_timeout, Event, State) ->
hello(Type, Event, State) ->
ssl_connection:hello(Type, Event, State, ?MODULE).
+abbreviated(enter, _, State0) ->
+ {State, Actions} = handle_flight_timer(State0),
+ {keep_state, State, Actions};
abbreviated(info, Event, State) ->
handle_info(Event, abbreviated, State);
abbreviated(internal = Type,
@@ -391,6 +403,9 @@ abbreviated(state_timeout, Event, State) ->
abbreviated(Type, Event, State) ->
ssl_connection:abbreviated(Type, Event, State, ?MODULE).
+certify(enter, _, State0) ->
+ {State, Actions} = handle_flight_timer(State0),
+ {keep_state, State, Actions};
certify(info, Event, State) ->
handle_info(Event, certify, State);
certify(internal = Type, #server_hello_done{} = Event, State) ->
@@ -400,6 +415,9 @@ certify(state_timeout, Event, State) ->
certify(Type, Event, State) ->
ssl_connection:certify(Type, Event, State, ?MODULE).
+cipher(enter, _, State0) ->
+ {State, Actions} = handle_flight_timer(State0),
+ {keep_state, State, Actions};
cipher(info, Event, State) ->
handle_info(Event, cipher, State);
cipher(internal = Type, #change_cipher_spec{type = <<1>>} = Event,
@@ -417,6 +435,8 @@ cipher(state_timeout, Event, State) ->
cipher(Type, Event, State) ->
ssl_connection:cipher(Type, Event, State, ?MODULE).
+connection(enter, _, State) ->
+ {keep_state, State};
connection(info, Event, State) ->
handle_info(Event, connection, State);
connection(internal, #hello_request{}, #state{host = Host, port = Port,
@@ -449,6 +469,9 @@ connection(internal, #client_hello{}, #state{role = server, allow_renegotiate =
connection(Type, Event, State) ->
ssl_connection:connection(Type, Event, State, ?MODULE).
+%%TODO does this make sense for DTLS ?
+downgrade(enter, _, State) ->
+ {keep_state, State};
downgrade(Type, Event, State) ->
ssl_connection:downgrade(Type, Event, State, ?MODULE).
@@ -841,13 +864,13 @@ next_flight(Flight) ->
change_cipher_spec => undefined,
handshakes_after_change_cipher_spec => []}.
-start_flight(#state{transport_cb = gen_udp,
- flight_state = {retransmit, Timeout}} = State) ->
+handle_flight_timer(#state{transport_cb = gen_udp,
+ flight_state = {retransmit, Timeout}} = State) ->
start_retransmision_timer(Timeout, State);
-start_flight(#state{transport_cb = gen_udp,
+handle_flight_timer(#state{transport_cb = gen_udp,
flight_state = connection} = State) ->
{State, []};
-start_flight(State) ->
+handle_flight_timer(State) ->
%% No retransmision needed i.e DTLS over SCTP
{State#state{flight_state = reliable}, []}.
--
2.13.1
