%% Copyright (c) 2011, Loïc Hoguin %% %% Permission to use, copy, modify, and/or distribute this software for any %% purpose with or without fee is hereby granted, provided that the above %% copyright notice and this permission notice appear in all copies. %% %% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES %% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF %% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR %% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES %% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN %% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF %% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. %% @doc WebSocket protocol draft hixie-76 implementation. %% %% Known to work with the following browsers: %% -module(cowboy_http_websocket). -export([upgrade/3]). %% API. -export([handler_loop/4]). %% Internal. -include("include/http.hrl"). -include_lib("eunit/include/eunit.hrl"). -record(state, { handler :: module(), opts :: any(), origin = undefined :: undefined | binary(), challenge = undefined :: undefined | binary(), timeout = infinity :: timeout(), messages = undefined :: undefined | {atom(), atom(), atom()}, eop :: tuple(), hibernate = false :: boolean() }). %% @doc Upgrade a HTTP request to the WebSocket protocol. %% %% You do not need to call this function manually. To upgrade to the WebSocket %% protocol, you simply need to return {upgrade, protocol, {@module}} %% in your cowboy_http_handler:init/3 handler function. -spec upgrade(module(), any(), #http_req{}) -> ok. upgrade(Handler, Opts, Req) -> EOP = binary:compile_pattern(<< 255 >>), case catch websocket_upgrade(#state{handler=Handler, opts=Opts, eop=EOP}, Req) of {ok, State, Req2} -> handler_init(State, Req2); {'EXIT', _Reason} -> upgrade_error(Req) end. -spec websocket_upgrade(#state{}, #http_req{}) -> {ok, #state{}, #http_req{}}. websocket_upgrade(State, Req) -> {<<"Upgrade">>, Req2} = cowboy_http_req:header('Connection', Req), {<<"WebSocket">>, Req3} = cowboy_http_req:header('Upgrade', Req2), {Origin, Req4} = cowboy_http_req:header(<<"Origin">>, Req3), {Key1, Req5} = cowboy_http_req:header(<<"Sec-Websocket-Key1">>, Req4), {Key2, Req6} = cowboy_http_req:header(<<"Sec-Websocket-Key2">>, Req5), false = lists:member(undefined, [Origin, Key1, Key2]), {ok, Key3, Req7} = cowboy_http_req:body(8, Req6), Challenge = challenge(Key1, Key2, Key3), {ok, State#state{origin=Origin, challenge=Challenge}, Req7}. -spec challenge(binary(), binary(), binary()) -> binary(). challenge(Key1, Key2, Key3) -> IntKey1 = key_to_integer(Key1), IntKey2 = key_to_integer(Key2), erlang:md5(<< IntKey1:32, IntKey2:32, Key3/binary >>). -spec key_to_integer(binary()) -> integer(). key_to_integer(Key) -> Number = list_to_integer([C || << C >> <= Key, C >= $0, C =< $9]), Spaces = length([C || << C >> <= Key, C =:= 32]), Number div Spaces. -spec handler_init(#state{}, #http_req{}) -> ok. handler_init(State=#state{handler=Handler, opts=Opts}, Req=#http_req{transport=Transport}) -> try Handler:websocket_init(Transport:name(), Req, Opts) of {ok, Req2, HandlerState} -> websocket_handshake(State, Req2, HandlerState); {ok, Req2, HandlerState, Timeout} -> websocket_handshake(State#state{timeout=Timeout}, Req2, HandlerState) catch Class:Reason -> upgrade_error(Req), error_logger:error_msg( "** Handler ~p terminating in websocket_init/3~n" " for the reason ~p:~p~n** Options were ~p~n" "** Request was ~p~n** Stacktrace: ~p~n~n", [Handler, Class, Reason, Opts, Req, erlang:get_stacktrace()]) end. -spec upgrade_error(#http_req{}) -> ok. upgrade_error(Req=#http_req{socket=Socket, transport=Transport}) -> {ok, _Req} = cowboy_http_req:reply(400, [], [], Req#http_req{resp_state=waiting}), Transport:close(Socket). -spec websocket_handshake(#state{}, #http_req{}, any()) -> ok. websocket_handshake(State=#state{origin=Origin, challenge=Challenge}, Req=#http_req{transport=Transport, raw_host=Host, port=Port, raw_path=Path}, HandlerState) -> Location = websocket_location(Transport:name(), Host, Port, Path), {ok, Req2} = cowboy_http_req:reply( <<"101 WebSocket Protocol Handshake">>, [{<<"Connection">>, <<"Upgrade">>}, {<<"Upgrade">>, <<"WebSocket">>}, {<<"Sec-WebSocket-Location">>, Location}, {<<"Sec-WebSocket-Origin">>, Origin}], Challenge, Req#http_req{resp_state=waiting}), handler_before_loop(State#state{messages=Transport:messages()}, Req2, HandlerState, <<>>). -spec websocket_location(atom(), binary(), inet:ip_port(), binary()) -> binary(). websocket_location(Protocol, Host, Port, Path) -> << (websocket_location_protocol(Protocol))/binary, "://", Host/binary, (websocket_location_port(ssl, Port))/binary, Path/binary >>. -spec websocket_location_protocol(atom()) -> binary(). websocket_location_protocol(ssl) -> <<"wss">>; websocket_location_protocol(_) -> <<"ws">>. -spec websocket_location_port(atom(), inet:ip_port()) -> binary(). websocket_location_port(ssl, 443) -> <<"">>; websocket_location_port(_, 80) -> <<"">>; websocket_location_port(_, Port) -> <<":", (list_to_binary(integer_to_list(Port)))/binary>>. -spec handler_before_loop(#state{}, #http_req{}, any(), binary()) -> ok. handler_before_loop(State=#state{hibernate=true}, Req=#http_req{socket=Socket, transport=Transport}, HandlerState, SoFar) -> Transport:setopts(Socket, [{active, once}]), erlang:hibernate(?MODULE, handler_loop, [State#state{hibernate=false}, Req, HandlerState, SoFar]); handler_before_loop(State, Req=#http_req{socket=Socket, transport=Transport}, HandlerState, SoFar) -> Transport:setopts(Socket, [{active, once}]), handler_loop(State, Req, HandlerState, SoFar). %% @private -spec handler_loop(#state{}, #http_req{}, any(), binary()) -> ok. handler_loop(State=#state{messages={OK, Closed, Error}, timeout=Timeout}, Req=#http_req{socket=Socket}, HandlerState, SoFar) -> receive {OK, Socket, Data} -> websocket_data(State, Req, HandlerState, << SoFar/binary, Data/binary >>); {Closed, Socket} -> handler_terminate(State, Req, HandlerState, {error, closed}); {Error, Socket, Reason} -> handler_terminate(State, Req, HandlerState, {error, Reason}); Message -> handler_call(State, Req, HandlerState, SoFar, websocket_info, Message, fun handler_before_loop/4) after Timeout -> websocket_close(State, Req, HandlerState, {normal, timeout}) end. -spec websocket_data(#state{}, #http_req{}, any(), binary()) -> ok. websocket_data(State, Req, HandlerState, << 255, 0, _Rest/bits >>) -> websocket_close(State, Req, HandlerState, {normal, closed}); websocket_data(State, Req, HandlerState, <<>>) -> handler_before_loop(State, Req, HandlerState, <<>>); websocket_data(State, Req, HandlerState, Data) -> websocket_frame(State, Req, HandlerState, Data, binary:first(Data)). %% We do not support any frame type other than 0 yet. Just like the specs. -spec websocket_frame(#state{}, #http_req{}, any(), binary(), byte()) -> ok. websocket_frame(State=#state{eop=EOP}, Req, HandlerState, Data, 0) -> case binary:match(Data, EOP) of {Pos, 1} -> Pos2 = Pos - 1, << 0, Frame:Pos2/binary, 255, Rest/bits >> = Data, handler_call(State, Req, HandlerState, Rest, websocket_handle, Frame, fun websocket_data/4); nomatch -> %% @todo We probably should allow limiting frame length. handler_before_loop(State, Req, HandlerState, Data) end; websocket_frame(State, Req, HandlerState, _Data, _FrameType) -> websocket_close(State, Req, HandlerState, {error, badframe}). -spec handler_call(#state{}, #http_req{}, any(), binary(), atom(), any(), fun()) -> ok. handler_call(State=#state{handler=Handler, opts=Opts}, Req, HandlerState, RemainingData, Callback, Message, NextState) -> try Handler:Callback(Message, Req, HandlerState) of {ok, Req2, HandlerState2} -> NextState(State, Req2, HandlerState2, RemainingData); {ok, Req2, HandlerState2, hibernate} -> NextState(State#state{hibernate=true}, Req2, HandlerState2, RemainingData); {reply, Data, Req2, HandlerState2} -> websocket_send(Data, Req2), NextState(State, Req2, HandlerState2, RemainingData); {reply, Data, Req2, HandlerState2, hibernate} -> websocket_send(Data, Req2), NextState(State#state{hibernate=true}, Req2, HandlerState2, RemainingData); {shutdown, Req2, HandlerState2} -> websocket_close(State, Req2, HandlerState2, {normal, shutdown}) catch Class:Reason -> error_logger:error_msg( "** Handler ~p terminating in websocket_handle/3~n" " for the reason ~p:~p~n** Message was ~p~n" "** Options were ~p~n** Handler state was ~p~n" "** Request was ~p~n** Stacktrace: ~p~n~n", [Handler, Class, Reason, Message, Opts, HandlerState, Req, erlang:get_stacktrace()]), websocket_close(State, Req, HandlerState, {error, handler}) end. -spec websocket_send(binary(), #http_req{}) -> ok. websocket_send(Data, #http_req{socket=Socket, transport=Transport}) -> Transport:send(Socket, << 0, Data/binary, 255 >>). -spec websocket_close(#state{}, #http_req{}, any(), {atom(), atom()}) -> ok. websocket_close(State, Req=#http_req{socket=Socket, transport=Transport}, HandlerState, Reason) -> Transport:send(Socket, << 255, 0 >>), Transport:close(Socket), handler_terminate(State, Req, HandlerState, Reason). -spec handler_terminate(#state{}, #http_req{}, any(), atom() | {atom(), atom()}) -> ok. handler_terminate(#state{handler=Handler, opts=Opts}, Req, HandlerState, TerminateReason) -> try Handler:websocket_terminate(TerminateReason, Req, HandlerState) catch Class:Reason -> error_logger:error_msg( "** Handler ~p terminating in websocket_terminate/3~n" " for the reason ~p:~p~n** Initial reason was ~p~n" "** Options were ~p~n** Handler state was ~p~n" "** Request was ~p~n** Stacktrace: ~p~n~n", [Handler, Class, Reason, TerminateReason, Opts, HandlerState, Req, erlang:get_stacktrace()]) end. %% Tests. -ifdef(TEST). websocket_location_test() -> ?assertEqual(<<"ws://localhost/path">>, websocket_location(other, <<"localhost">>, 80, <<"/path">>)), ?assertEqual(<<"ws://localhost:8080/path">>, websocket_location(other, <<"localhost">>, 8080, <<"/path">>)), ?assertEqual(<<"wss://localhost/path">>, websocket_location(ssl, <<"localhost">>, 443, <<"/path">>)), ?assertEqual(<<"wss://localhost:8443/path">>, websocket_location(ssl, <<"localhost">>, 8443, <<"/path">>)), ok. -endif.