ssl: Implement DTLS state machine

Beta DTLS, not production ready. Only very basically tested, and
not everything in the SPEC is implemented and some things
are hard coded that should not be, so this implementation can not be consider
secure.

Refactor "TLS connection state" and socket handling, to facilitate
DTLS implementation.

Create dtls "listner" (multiplexor) process that spawns
DTLS connection process handlers.

Handle DTLS fragmentation.

Framework for handling retransmissions.

Replay Detection is not implemented yet.

Alerts currently always handled as in TLS.

1 files changed, 330 insertions, 0 deletions

diff --git a/lib/ssl/src/tls_socket.erl b/lib/ssl/src/tls_socket.erl
new file mode 100644
index 0000000000..e76d9c100a
--- /dev/null
+++ b/lib/ssl/src/tls_socket.erl
@@ -0,0 +1,330 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1998-2016. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(tls_socket).
+
+-behaviour(gen_server).
+
+-include("ssl_internal.hrl").
+-include("ssl_api.hrl").
+
+-export([send/3, listen/3, accept/3, socket/5, connect/4, upgrade/3,
+	 setopts/3, getopts/3, getstat/3, peername/2, sockname/2, port/2]).
+-export([split_options/1, get_socket_opts/3]).
+-export([emulated_options/0, internal_inet_values/0, default_inet_values/0,
+	 init/1, start_link/3, terminate/2, inherit_tracker/3, 
+	 emulated_socket_options/2, get_emulated_opts/1, 
+	 set_emulated_opts/2, get_all_opts/1, handle_call/3, handle_cast/2,
+	 handle_info/2, code_change/3]).
+
+-record(state, {
+	  emulated_opts,
+	  port,
+	  ssl_opts
+	 }).
+
+%%--------------------------------------------------------------------
+%%% Internal API
+%%--------------------------------------------------------------------
+send(Transport, Socket, Data) ->
+    Transport:send(Socket, Data).
+
+listen(Transport, Port, #config{transport_info = {Transport, _, _, _}, 
+				inet_user = Options, 
+				ssl = SslOpts, emulated = EmOpts} = Config) ->
+    case Transport:listen(Port, Options ++ internal_inet_values()) of
+	{ok, ListenSocket} ->
+	    {ok, Tracker} = inherit_tracker(ListenSocket, EmOpts, SslOpts),
+	    {ok, #sslsocket{pid = {ListenSocket, Config#config{emulated = Tracker}}}};
+	Err = {error, _} ->
+	    Err
+    end.
+
+accept(ListenSocket, #config{transport_info = {Transport,_,_,_} = CbInfo,
+			     connection_cb = ConnectionCb,
+			     ssl = SslOpts,
+			     emulated = Tracker}, Timeout) -> 
+    case Transport:accept(ListenSocket, Timeout) of
+	{ok, Socket} ->
+	    {ok, EmOpts} = get_emulated_opts(Tracker),
+	    {ok, Port} = tls_socket:port(Transport, Socket),
+	    ConnArgs = [server, "localhost", Port, Socket,
+			{SslOpts, emulated_socket_options(EmOpts, #socket_options{}), Tracker}, self(), CbInfo],
+	    case tls_connection_sup:start_child(ConnArgs) of
+		{ok, Pid} ->
+		    ssl_connection:socket_control(ConnectionCb, Socket, Pid, Transport, Tracker);
+		{error, Reason} ->
+		    {error, Reason}
+	    end;
+	{error, Reason} ->
+	    {error, Reason}
+    end.
+
+upgrade(Socket, #config{transport_info = {Transport,_,_,_}= CbInfo,
+			ssl = SslOptions,
+			emulated = EmOpts, connection_cb = ConnectionCb}, Timeout) ->
+    ok = setopts(Transport, Socket, tls_socket:internal_inet_values()),
+    case peername(Transport, Socket) of
+	{ok, {Address, Port}} ->
+	    ssl_connection:connect(ConnectionCb, Address, Port, Socket,
+				   {SslOptions, 
+				    emulated_socket_options(EmOpts, #socket_options{}), undefined},
+				   self(), CbInfo, Timeout);
+	{error, Error} ->
+	    {error, Error}
+    end.
+
+connect(Address, Port,
+	#config{transport_info = CbInfo, inet_user = UserOpts, ssl = SslOpts,
+		emulated = EmOpts, inet_ssl = SocketOpts, connection_cb = ConnetionCb},
+	Timeout) ->
+    {Transport, _, _, _} = CbInfo,
+    try Transport:connect(Address, Port,  SocketOpts, Timeout) of
+	{ok, Socket} ->
+	    ssl_connection:connect(ConnetionCb, Address, Port, Socket, 
+				   {SslOpts, 
+				    emulated_socket_options(EmOpts, #socket_options{}), undefined},
+				   self(), CbInfo, Timeout);
+	{error, Reason} ->
+	    {error, Reason}
+    catch
+	exit:{function_clause, _} ->
+	    {error, {options, {cb_info, CbInfo}}};
+	exit:badarg ->
+	    {error, {options, {socket_options, UserOpts}}};
+	exit:{badarg, _} ->
+	    {error, {options, {socket_options, UserOpts}}}
+    end.
+
+socket(Pid, Transport, Socket, ConnectionCb, Tracker) ->
+    #sslsocket{pid = Pid, 
+	       %% "The name "fd" is keept for backwards compatibility
+	       fd = {Transport, Socket, ConnectionCb, Tracker}}.
+setopts(gen_tcp, #sslsocket{pid = {ListenSocket, #config{emulated = Tracker}}}, Options) ->
+    {SockOpts, EmulatedOpts} = split_options(Options),
+    ok = set_emulated_opts(Tracker, EmulatedOpts),
+    inet:setopts(ListenSocket, SockOpts);
+setopts(_, #sslsocket{pid = {ListenSocket, #config{transport_info = {Transport,_,_,_},
+						  emulated = Tracker}}}, Options) ->
+    {SockOpts, EmulatedOpts} = split_options(Options),
+    ok = set_emulated_opts(Tracker, EmulatedOpts),
+    Transport:setopts(ListenSocket, SockOpts);
+%%% Following clauses will not be called for emulated options, they are  handled in the connection process
+setopts(gen_tcp, Socket, Options) ->
+    inet:setopts(Socket, Options);
+setopts(Transport, Socket, Options) ->
+    Transport:setopts(Socket, Options).
+
+getopts(gen_tcp,  #sslsocket{pid = {ListenSocket, #config{emulated = Tracker}}}, Options) ->
+    {SockOptNames, EmulatedOptNames} = split_options(Options),
+    EmulatedOpts = get_emulated_opts(Tracker, EmulatedOptNames),
+    SocketOpts = get_socket_opts(ListenSocket, SockOptNames, inet),
+    {ok, EmulatedOpts ++ SocketOpts}; 
+getopts(Transport,  #sslsocket{pid = {ListenSocket, #config{emulated = Tracker}}}, Options) ->
+    {SockOptNames, EmulatedOptNames} = split_options(Options),
+    EmulatedOpts = get_emulated_opts(Tracker, EmulatedOptNames),
+    SocketOpts = get_socket_opts(ListenSocket, SockOptNames, Transport),
+    {ok, EmulatedOpts ++ SocketOpts}; 
+%%% Following clauses will not be called for emulated options, they are  handled in the connection process
+getopts(gen_tcp, Socket, Options) ->
+    inet:getopts(Socket, Options);
+getopts(Transport, Socket, Options) ->
+    Transport:getopts(Socket, Options).
+
+getstat(gen_tcp, Socket, Options) ->
+	inet:getstat(Socket, Options);
+getstat(Transport, Socket, Options) ->
+	Transport:getstat(Socket, Options).
+
+peername(gen_tcp, Socket) ->
+    inet:peername(Socket);
+peername(Transport, Socket) ->
+    Transport:peername(Socket).
+
+sockname(gen_tcp, Socket) ->
+    inet:sockname(Socket);
+sockname(Transport, Socket) ->
+    Transport:sockname(Socket).
+
+port(gen_tcp, Socket) ->
+    inet:port(Socket);
+port(Transport, Socket) ->
+    Transport:port(Socket).
+
+emulated_options() ->
+    [mode, packet, active, header, packet_size].
+
+internal_inet_values() ->
+    [{packet_size,0}, {packet, 0}, {header, 0}, {active, false}, {mode,binary}].
+
+default_inet_values() ->
+    [{packet_size, 0}, {packet,0}, {header, 0}, {active, true}, {mode, list}].
+
+inherit_tracker(ListenSocket, EmOpts, #ssl_options{erl_dist = false} = SslOpts) ->
+    ssl_listen_tracker_sup:start_child([ListenSocket, EmOpts, SslOpts]);
+inherit_tracker(ListenSocket, EmOpts, #ssl_options{erl_dist = true} = SslOpts) ->
+    ssl_listen_tracker_sup:start_child_dist([ListenSocket, EmOpts, SslOpts]).
+
+get_emulated_opts(TrackerPid) -> 
+    call(TrackerPid, get_emulated_opts).
+set_emulated_opts(TrackerPid, InetValues) -> 
+    call(TrackerPid, {set_emulated_opts, InetValues}).
+get_all_opts(TrackerPid) -> 
+    call(TrackerPid, get_all_opts).
+
+%%====================================================================
+%% ssl_listen_tracker_sup API
+%%====================================================================
+
+start_link(Port, SockOpts, SslOpts) ->
+    gen_server:start_link(?MODULE, [Port, SockOpts, SslOpts], []).
+
+%%--------------------------------------------------------------------
+-spec init(list()) -> {ok, #state{}}.
+%% Possible return values not used now. 
+%% |  {ok, #state{}, timeout()} | ignore | {stop, term()}.		  
+%%
+%% Description: Initiates the server
+%%--------------------------------------------------------------------
+init([Port, Opts, SslOpts]) ->
+    process_flag(trap_exit, true),
+    true = link(Port),
+    {ok, #state{emulated_opts = Opts, port = Port, ssl_opts = SslOpts}}.
+
+%%--------------------------------------------------------------------
+-spec handle_call(msg(), from(), #state{}) -> {reply, reply(), #state{}}. 
+%% Possible return values not used now.  
+%%					      {reply, reply(), #state{}, timeout()} |
+%%					      {noreply, #state{}} |
+%%					      {noreply, #state{}, timeout()} |
+%%					      {stop, reason(), reply(), #state{}} |
+%%					      {stop, reason(), #state{}}.
+%%
+%% Description: Handling call messages
+%%--------------------------------------------------------------------
+handle_call({set_emulated_opts, Opts0}, _From,
+	    #state{emulated_opts = Opts1} = State) ->
+    Opts = do_set_emulated_opts(Opts0, Opts1),
+    {reply, ok, State#state{emulated_opts = Opts}};
+handle_call(get_emulated_opts, _From,
+	    #state{emulated_opts = Opts} = State) ->
+    {reply, {ok, Opts}, State};
+handle_call(get_all_opts, _From,
+	    #state{emulated_opts = EmOpts,
+		   ssl_opts = SslOpts} = State) ->
+    {reply, {ok, EmOpts, SslOpts}, State}.
+
+%%--------------------------------------------------------------------
+-spec  handle_cast(msg(), #state{}) -> {noreply, #state{}}.
+%% Possible return values not used now.  
+%%				      | {noreply, #state{}, timeout()} |
+%%				       {stop, reason(), #state{}}.
+%%
+%% Description: Handling cast messages
+%%--------------------------------------------------------------------
+handle_cast(_, State)-> 
+    {noreply, State}.
+
+%%--------------------------------------------------------------------
+-spec handle_info(msg(), #state{}) ->  {stop, reason(), #state{}}. 
+%% Possible return values not used now.
+%%			              {noreply, #state{}}.
+%%				      |{noreply, #state{}, timeout()} |
+%%				     
+%%
+%% Description: Handling all non call/cast messages
+%%-------------------------------------------------------------------
+handle_info({'EXIT', Port, _}, #state{port = Port} = State) ->
+    {stop, normal, State}.
+
+
+%%--------------------------------------------------------------------
+-spec terminate(reason(), #state{}) -> ok.
+%%		       
+%% Description: This function is called by a gen_server when it is about to
+%% terminate. It should be the opposite of Module:init/1 and do any necessary
+%% cleaning up. When it returns, the gen_server terminates with Reason.
+%% The return value is ignored.
+%%--------------------------------------------------------------------
+terminate(_Reason, _State) ->
+    ok.
+
+%%--------------------------------------------------------------------
+-spec code_change(term(), #state{}, list()) -> {ok, #state{}}.			 
+%%
+%% Description: Convert process state when code is changed
+%%--------------------------------------------------------------------
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+%%--------------------------------------------------------------------
+%%% Internal functions
+%%--------------------------------------------------------------------
+call(Pid, Msg) ->
+    gen_server:call(Pid, Msg, infinity).
+
+split_options(Opts) ->
+    split_options(Opts, emulated_options(), [], []).
+split_options([], _, SocketOpts, EmuOpts) ->
+    {SocketOpts, EmuOpts};
+split_options([{Name, _} = Opt | Opts], Emu, SocketOpts, EmuOpts) ->
+    case lists:member(Name, Emu) of
+	true ->
+	    split_options(Opts, Emu, SocketOpts, [Opt | EmuOpts]);
+	false ->
+	    split_options(Opts, Emu, [Opt | SocketOpts], EmuOpts)
+    end;
+split_options([Name | Opts], Emu, SocketOptNames, EmuOptNames) ->
+    case lists:member(Name, Emu) of
+	true ->
+	    split_options(Opts, Emu, SocketOptNames, [Name | EmuOptNames]);
+	false ->
+	    split_options(Opts, Emu, [Name | SocketOptNames], EmuOptNames)
+    end.
+
+do_set_emulated_opts([], Opts) ->
+    Opts;
+do_set_emulated_opts([{Name,_} = Opt | Rest], Opts) ->
+    do_set_emulated_opts(Rest, [Opt | proplists:delete(Name, Opts)]).
+
+get_socket_opts(_, [], _) ->
+    [];
+get_socket_opts(ListenSocket, SockOptNames, Cb) ->
+    {ok, Opts} = Cb:getopts(ListenSocket, SockOptNames),
+    Opts.
+
+get_emulated_opts(TrackerPid, EmOptNames) -> 
+    {ok, EmOpts} = get_emulated_opts(TrackerPid),
+    lists:map(fun(Name) -> {value, Value} = lists:keysearch(Name, 1, EmOpts),
+			   Value end,
+	      EmOptNames).
+
+emulated_socket_options(InetValues, #socket_options{
+				       mode   = Mode,
+				       header = Header,
+				       active = Active,
+				       packet = Packet,
+				       packet_size = Size}) ->
+    #socket_options{
+       mode   = proplists:get_value(mode, InetValues, Mode),
+       header = proplists:get_value(header, InetValues, Header),
+       active = proplists:get_value(active, InetValues, Active),
+       packet = proplists:get_value(packet, InetValues, Packet),
+       packet_size = proplists:get_value(packet_size, InetValues, Size)
+      }.