Add the 'ranch_transport' behaviour

At the same time we make the 'port' option optional, defaulting to 0.

src/ranch.erl

@@ -22,6 +22,9 @@
 -export([get_port/1]).
 -export([get_protocol_options/1]).
 -export([set_protocol_options/2]).
+-export([filter_options/3]).
+-export([set_option_default/3]).
+-export([require/1]).
 
 %% @doc Start a listener for the given transport and protocol.
 %%
@@ -112,3 +115,38 @@ get_protocol_options(Ref) ->
 set_protocol_options(Ref, ProtoOpts) ->
 	ListenerPid = ranch_server:lookup_listener(Ref),
 	ok = ranch_listener:set_protocol_options(ListenerPid, ProtoOpts).
+
+%% @doc Filter a list of options and remove all unwanted values.
+%%
+%% It takes a list of options, a list of allowed keys and an accumulator.
+%% This accumulator can be used to set default options that should never
+%% be overriden.
+-spec filter_options([{atom(), any()}], [atom()], Acc)
+	-> Acc when Acc :: [any()].
+filter_options([], _, Acc) ->
+	Acc;
+filter_options([Opt = {Key, _}|Tail], AllowedKeys, Acc) ->
+	case lists:member(Key, AllowedKeys) of
+		true -> filter_options(Tail, AllowedKeys, [Opt|Acc]);
+		false -> filter_options(Tail, AllowedKeys, Acc)
+	end.
+
+%% @doc Add an option to a list, but only if it wasn't previously set.
+-spec set_option_default(Opts, atom(), any())
+	-> Opts when Opts :: [{atom(), any()}].
+set_option_default(Opts, Key, Value) ->
+	case lists:keymember(Key, 1, Opts) of
+		true -> Opts;
+		false -> [{Key, Value}|Opts]
+	end.
+
+%% @doc Start the given applications if they were not already started.
+-spec require(list(module())) -> ok.
+require([]) ->
+	ok;
+require([App|Tail]) ->
+	case application:start(App) of
+		ok -> ok;
+		{error, {already_started, App}} -> ok
+	end,
+	require(Tail).

src/ranch_ssl.erl

@@ -23,90 +23,79 @@
 %%
 %% @see ssl
 -module(ranch_ssl).
+-behaviour(ranch_transport).
 
 -export([name/0]).
 -export([messages/0]).
--export([connect/3]).
 -export([listen/1]).
 -export([accept/2]).
+-export([connect/3]).
 -export([recv/3]).
 -export([send/2]).
 -export([setopts/2]).
 -export([controlling_process/2]).
 -export([peername/1]).
--export([close/1]).
 -export([sockname/1]).
+-export([close/1]).
 
-%% @doc Name of this transport API, <em>ssl</em>.
--spec name() -> ssl.
+%% @doc Name of this transport, <em>ssl</em>.
 name() -> ssl.
 
-%% @doc Atoms used in the process messages sent by this API.
-%%
-%% They identify incoming data, closed connection and errors when receiving
-%% data in active mode.
--spec messages() -> {ssl, ssl_closed, ssl_error}.
+%% @doc Atoms used to identify messages in {active, once | true} mode.
 messages() -> {ssl, ssl_closed, ssl_error}.
 
-%% @private
-%% @todo Probably filter Opts?
--spec connect(string(), inet:port_number(), any())
-	-> {ok, inet:socket()} | {error, atom()}.
-connect(Host, Port, Opts) when is_list(Host), is_integer(Port) ->
-	ssl:connect(Host, Port,
-		Opts ++ [binary, {active, false}, {packet, raw}]).
-
-%% @doc Setup a socket to listen on the given port on the local host.
+%% @doc Listen for connections on the given port number.
 %%
+%% Calling this function returns a listening socket that can then
 %% The available options are:
+%%
 %% <dl>
-%%  <dt>port</dt><dd>Mandatory. TCP port number to open.</dd>
 %%  <dt>backlog</dt><dd>Maximum length of the pending connections queue.
 %%   Defaults to 1024.</dd>
-%%  <dt>ip</dt><dd>Interface to listen on. Listen on all interfaces
-%%   by default.</dd>
+%%  <dt>cacertfile</dt><dd>Optional. Path to file containing PEM encoded
+%%   CA certificates (trusted certificates used for verifying a peer
+%%   certificate).</dd>
 %%  <dt>certfile</dt><dd>Mandatory. Path to a file containing the user's
 %%   certificate.</dd>
+%%  <dt>ciphers</dt><dd>Optional. The cipher suites that should be supported.
+%%   The function ssl:cipher_suites/0 can be used to find all available
+%%   ciphers.</dd>
+%%  <dt>ip</dt><dd>Interface to listen on. Listen on all interfaces
+%%   by default.</dd>
 %%  <dt>keyfile</dt><dd>Optional. Path to the file containing the user's
 %%   private PEM encoded key.</dd>
-%%  <dt>cacertfile</dt><dd>Optional. Path to file containing PEM encoded
-%%   CA certificates (trusted certificates used for verifying a peer
-%%   certificate).</dd>
 %%  <dt>password</dt><dd>Optional. String containing the user's password.
 %%   All private keyfiles must be password protected currently.</dd>
-%%  <dt>ciphers</dt><dd>Optional. The cipher suites that should be supported.
-%%  The function ssl:cipher_suites/0 can be used to find all available
-%%  ciphers.</dd>
+%%  <dt>port</dt><dd>TCP port number to open. Defaults to 0 (see below)</dd>
 %% </dl>
 %%
+%% You can listen to a random port by setting the port option to 0.
+%% It is then possible to retrieve this port number by calling
+%% sockname/1 on the listening socket. If you are using Ranch's
+%% listener API, then this port number can obtained through
+%% ranch:get_port/1 instead.
+%%
 %% @see ssl:listen/2
--spec listen([{port, inet:port_number()} | {certfile, string()}
-	| {keyfile, string()} | {password, string()}
-	| {cacertfile, string()} | {ip, inet:ip_address()}])
+-spec listen([{backlog, non_neg_integer()} | {cacertfile, string()}
+	| {certfile, string()} | {ciphers, [ssl:erl_cipher_suite()] | string()}
+	| {ip, inet:ip_address()} | {keyfile, string()} | {password, string()}
+	| {port, inet:port_number()}])
 	-> {ok, ssl:sslsocket()} | {error, atom()}.
 listen(Opts) ->
-	require([crypto, public_key, ssl]),
-	{port, Port} = lists:keyfind(port, 1, Opts),
-	Backlog = proplists:get_value(backlog, Opts, 1024),
-	{certfile, CertFile} = lists:keyfind(certfile, 1, Opts),
-
-	ListenOpts0 = [binary, {active, false},
-		{backlog, Backlog}, {packet, raw}, {reuseaddr, true},
-		{certfile, CertFile}],
-	ListenOpts = lists:foldl(fun
-		({ip, _} = Ip, Acc) -> [Ip | Acc];
-		({keyfile, _} = KeyFile, Acc) -> [KeyFile | Acc];
-		({cacertfile, _} = CACertFile, Acc) -> [CACertFile | Acc];
-		({password, _} = Password, Acc) -> [Password | Acc];
-		({ciphers, _} = Ciphers, Acc) -> [Ciphers | Acc];
-		(_, Acc) -> Acc
-	end, ListenOpts0, Opts),
-	ssl:listen(Port, ListenOpts).
-
-%% @doc Accept an incoming connection on a listen socket.
+	ranch:require([crypto, public_key, ssl]),
+	{certfile, _} = lists:keyfind(certfile, 1, Opts),
+	Opts2 = ranch:set_option_default(Opts, backlog, 1024),
+	%% We set the port to 0 because it is given in the Opts directly.
+	%% The port in the options takes precedence over the one in the
+	%% first argument.
+	ssl:listen(0, ranch:filter_options(Opts2,
+		[backlog, cacertfile, certfile, ciphers, ip, keyfile, password, port],
+		[binary, {active, false}, {packet, raw}, {reuseaddr, true}])).
+
+%% @doc Accept connections with the given listening socket.
 %%
 %% Note that this function does both the transport accept and
-%% the SSL handshake.
+%% the SSL handshake. The returned socket is thus fully connected.
 %%
 %% @see ssl:transport_accept/2
 %% @see ssl:ssl_accept/2
@@ -120,63 +109,67 @@ accept(LSocket, Timeout) ->
 			{error, Reason}
 	end.
 
-%% @doc Receive a packet from a socket in passive mode.
+%% @private Experimental. Open a connection to the given host and port number.
+%% @see ssl:connect/3
+%% @todo Probably filter Opts?
+-spec connect(string(), inet:port_number(), any())
+	-> {ok, inet:socket()} | {error, atom()}.
+connect(Host, Port, Opts) when is_list(Host), is_integer(Port) ->
+	ssl:connect(Host, Port,
+		Opts ++ [binary, {active, false}, {packet, raw}]).
+
+%% @doc Receive data from a socket in passive mode.
 %% @see ssl:recv/3
 -spec recv(ssl:sslsocket(), non_neg_integer(), timeout())
 	-> {ok, any()} | {error, closed | atom()}.
 recv(Socket, Length, Timeout) ->
 	ssl:recv(Socket, Length, Timeout).
 
-%% @doc Send a packet on a socket.
+%% @doc Send data on a socket.
 %% @see ssl:send/2
 -spec send(ssl:sslsocket(), iolist()) -> ok | {error, atom()}.
 send(Socket, Packet) ->
 	ssl:send(Socket, Packet).
 
-%% @doc Set one or more options for a socket.
+%% @doc Set options on the given socket.
 %% @see ssl:setopts/2
+%% @todo Probably filter Opts?
 -spec setopts(ssl:sslsocket(), list()) -> ok | {error, atom()}.
 setopts(Socket, Opts) ->
 	ssl:setopts(Socket, Opts).
 
-%% @doc Assign a new controlling process <em>Pid</em> to <em>Socket</em>.
+%% @doc Give control of the socket to a new process.
+%%
+%% Must be called from the process currently controlling the socket,
+%% otherwise an {error, not_owner} tuple will be returned.
+%%
 %% @see ssl:controlling_process/2
 -spec controlling_process(ssl:sslsocket(), pid())
 	-> ok | {error, closed | not_owner | atom()}.
 controlling_process(Socket, Pid) ->
 	ssl:controlling_process(Socket, Pid).
 
-%% @doc Return the address and port for the other end of a connection.
+%% @doc Return the remote address and port of the connection.
 %% @see ssl:peername/1
 -spec peername(ssl:sslsocket())
 	-> {ok, {inet:ip_address(), inet:port_number()}} | {error, atom()}.
 peername(Socket) ->
 	ssl:peername(Socket).
 
-%% @doc Close a TCP socket.
-%% @see ssl:close/1
--spec close(ssl:sslsocket()) -> ok.
-close(Socket) ->
-	ssl:close(Socket).
-
-%% @doc Get the local address and port of a socket
+%% @doc Return the local address and port of the connection.
 %% @see ssl:sockname/1
 -spec sockname(ssl:sslsocket())
 	-> {ok, {inet:ip_address(), inet:port_number()}} | {error, atom()}.
 sockname(Socket) ->
 	ssl:sockname(Socket).
 
-%% Internal.
+%% @doc Close the given socket.
+%% @see ssl:close/1
+-spec close(ssl:sslsocket()) -> ok.
+close(Socket) ->
+	ssl:close(Socket).
 
--spec require(list(module())) -> ok.
-require([]) ->
-	ok;
-require([App|Tail]) ->
-	case application:start(App) of
-		ok -> ok;
-		{error, {already_started, App}} -> ok
-	end,
-	require(Tail).
+%% Internal.
 
 -spec ssl_accept(ssl:sslsocket(), timeout())
 	-> {ok, ssl:sslsocket()} | {error, {ssl_accept, atom()}}.