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Diffstat (limited to 'src/cowboy_websocket.erl')
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diff --git a/src/cowboy_websocket.erl b/src/cowboy_websocket.erl new file mode 100644 index 0000000..fe383c2 --- /dev/null +++ b/src/cowboy_websocket.erl @@ -0,0 +1,609 @@ +%% Copyright (c) 2011-2012, Loïc Hoguin <[email protected]> +%% +%% 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 implementation. +%% +%% When using websockets, make sure that the crypto application is +%% included in your release. If you are not using releases then there +%% is no need for concern as crypto is already included. +-module(cowboy_websocket). + +%% API. +-export([upgrade/4]). + +%% Internal. +-export([handler_loop/4]). + +-include("http.hrl"). +-include_lib("eunit/include/eunit.hrl"). + +-type opcode() :: 0 | 1 | 2 | 8 | 9 | 10. +-type mask_key() :: 0..16#ffffffff. + +%% The websocket_data/4 function may be called multiple times for a message. +%% The websocket_dispatch/4 function is only called once for each message. +-type frag_state() :: + undefined | %% no fragmentation has been seen. + {nofin, opcode()} | %% first fragment has been seen. + {nofin, opcode(), binary()} | %% first fragment has been unmasked. + {fin, opcode(), binary()}. %% last fragment has been seen. + +-record(state, { + version :: 0 | 7 | 8 | 13, + handler :: module(), + opts :: any(), + challenge = undefined :: undefined | binary() | {binary(), binary()}, + timeout = infinity :: timeout(), + timeout_ref = undefined :: undefined | reference(), + messages = undefined :: undefined | {atom(), atom(), atom()}, + hibernate = false :: boolean(), + eop :: undefined | tuple(), %% hixie-76 specific. + origin = undefined :: undefined | binary(), %% hixie-76 specific. + frag_state = undefined :: frag_state() +}). + +%% @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 <em>{upgrade, protocol, {@module}}</em> +%% in your <em>cowboy_http_handler:init/3</em> handler function. +-spec upgrade(pid(), module(), any(), #http_req{}) -> closed. +upgrade(ListenerPid, Handler, Opts, Req) -> + ranch_listener:remove_connection(ListenerPid), + case catch websocket_upgrade(#state{handler=Handler, opts=Opts}, 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) -> + {ConnTokens, Req2} + = cowboy_req:parse_header('Connection', Req), + true = lists:member(<<"upgrade">>, ConnTokens), + %% @todo Should probably send a 426 if the Upgrade header is missing. + {[<<"websocket">>], Req3} = cowboy_req:parse_header('Upgrade', Req2), + {Version, Req4} = cowboy_req:header(<<"Sec-Websocket-Version">>, Req3), + websocket_upgrade(Version, State, Req4). + +%% @todo Handle the Sec-Websocket-Protocol header. +%% @todo Reply a proper error, don't die, if a required header is undefined. +-spec websocket_upgrade(undefined | <<_:8>>, #state{}, #http_req{}) + -> {ok, #state{}, #http_req{}}. +%% No version given. Assuming hixie-76 draft. +%% +%% We need to wait to send a reply back before trying to read the +%% third part of the challenge key, because proxies will wait for +%% a reply before sending it. Therefore we calculate the challenge +%% key only in websocket_handshake/3. +websocket_upgrade(undefined, State, Req=#http_req{meta=Meta}) -> + {Origin, Req2} = cowboy_req:header(<<"Origin">>, Req), + {Key1, Req3} = cowboy_req:header(<<"Sec-Websocket-Key1">>, Req2), + {Key2, Req4} = cowboy_req:header(<<"Sec-Websocket-Key2">>, Req3), + false = lists:member(undefined, [Origin, Key1, Key2]), + EOP = binary:compile_pattern(<< 255 >>), + {ok, State#state{version=0, origin=Origin, challenge={Key1, Key2}, + eop=EOP}, Req4#http_req{meta=[{websocket_version, 0}|Meta]}}; +%% Versions 7 and 8. Implementation follows the hybi 7 through 17 drafts. +websocket_upgrade(Version, State, Req=#http_req{meta=Meta}) + when Version =:= <<"7">>; Version =:= <<"8">>; + Version =:= <<"13">> -> + {Key, Req2} = cowboy_req:header(<<"Sec-Websocket-Key">>, Req), + false = Key =:= undefined, + Challenge = hybi_challenge(Key), + IntVersion = list_to_integer(binary_to_list(Version)), + {ok, State#state{version=IntVersion, challenge=Challenge}, + Req2#http_req{meta=[{websocket_version, IntVersion}|Meta]}}. + +-spec handler_init(#state{}, #http_req{}) -> closed. +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, hibernate} -> + websocket_handshake(State#state{hibernate=true}, + Req2, HandlerState); + {ok, Req2, HandlerState, Timeout} -> + websocket_handshake(State#state{timeout=Timeout}, + Req2, HandlerState); + {ok, Req2, HandlerState, Timeout, hibernate} -> + websocket_handshake(State#state{timeout=Timeout, + hibernate=true}, Req2, HandlerState); + {shutdown, Req2} -> + upgrade_denied(Req2) + catch Class:Reason -> + upgrade_error(Req), + PLReq = lists:zip(record_info(fields, http_req), tl(tuple_to_list(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, PLReq, erlang:get_stacktrace()]) + end. + +-spec upgrade_error(#http_req{}) -> closed. +upgrade_error(Req) -> + {ok, _Req2} = cowboy_req:reply(400, [], [], + Req#http_req{resp_state=waiting}), + closed. + +%% @see cowboy_protocol:ensure_response/1 +-spec upgrade_denied(#http_req{}) -> closed. +upgrade_denied(#http_req{resp_state=done}) -> + closed; +upgrade_denied(Req=#http_req{resp_state=waiting}) -> + {ok, _Req2} = cowboy_req:reply(400, [], [], Req), + closed; +upgrade_denied(#http_req{method='HEAD', resp_state=chunks}) -> + closed; +upgrade_denied(#http_req{socket=Socket, transport=Transport, + resp_state=chunks}) -> + Transport:send(Socket, <<"0\r\n\r\n">>), + closed. + +-spec websocket_handshake(#state{}, #http_req{}, any()) -> closed. +websocket_handshake(State=#state{version=0, origin=Origin, + challenge={Key1, Key2}}, Req=#http_req{socket=Socket, + transport=Transport, raw_host=Host, port=Port, + raw_path=Path, raw_qs=QS}, HandlerState) -> + Location = hixie76_location(Transport:name(), Host, Port, Path, QS), + {ok, Req2} = cowboy_req:upgrade_reply( + <<"101 WebSocket Protocol Handshake">>, + [{<<"Upgrade">>, <<"WebSocket">>}, + {<<"Sec-Websocket-Location">>, Location}, + {<<"Sec-Websocket-Origin">>, Origin}], + Req#http_req{resp_state=waiting}), + %% Flush the resp_sent message before moving on. + receive {cowboy_req, resp_sent} -> ok after 0 -> ok end, + %% We replied with a proper response. Proxies should be happy enough, + %% we can now read the 8 last bytes of the challenge keys and send + %% the challenge response directly to the socket. + %% + %% We use a trick here to read exactly 8 bytes of the body regardless + %% of what's in the buffer. + {ok, Req3} = cowboy_req:init_stream( + fun cowboy_http:te_identity/2, {0, 8}, + fun cowboy_http:ce_identity/1, Req2), + case cowboy_req:body(Req3) of + {ok, Key3, Req4} -> + Challenge = hixie76_challenge(Key1, Key2, Key3), + Transport:send(Socket, Challenge), + handler_before_loop(State#state{messages=Transport:messages()}, + Req4, HandlerState, <<>>); + _Any -> + closed %% If an error happened reading the body, stop there. + end; +websocket_handshake(State=#state{challenge=Challenge}, + Req=#http_req{transport=Transport}, HandlerState) -> + {ok, Req2} = cowboy_req:upgrade_reply( + 101, + [{<<"Upgrade">>, <<"websocket">>}, + {<<"Sec-Websocket-Accept">>, Challenge}], + Req#http_req{resp_state=waiting}), + %% Flush the resp_sent message before moving on. + receive {cowboy_req, resp_sent} -> ok after 0 -> ok end, + handler_before_loop(State#state{messages=Transport:messages()}, + Req2, HandlerState, <<>>). + +-spec handler_before_loop(#state{}, #http_req{}, any(), binary()) -> closed. +handler_before_loop(State=#state{hibernate=true}, + Req=#http_req{socket=Socket, transport=Transport}, + HandlerState, SoFar) -> + Transport:setopts(Socket, [{active, once}]), + State2 = handler_loop_timeout(State), + catch erlang:hibernate(?MODULE, handler_loop, + [State2#state{hibernate=false}, Req, HandlerState, SoFar]), + closed; +handler_before_loop(State, Req=#http_req{socket=Socket, transport=Transport}, + HandlerState, SoFar) -> + Transport:setopts(Socket, [{active, once}]), + State2 = handler_loop_timeout(State), + handler_loop(State2, Req, HandlerState, SoFar). + +-spec handler_loop_timeout(#state{}) -> #state{}. +handler_loop_timeout(State=#state{timeout=infinity}) -> + State#state{timeout_ref=undefined}; +handler_loop_timeout(State=#state{timeout=Timeout, timeout_ref=PrevRef}) -> + _ = case PrevRef of undefined -> ignore; PrevRef -> + erlang:cancel_timer(PrevRef) end, + TRef = erlang:start_timer(Timeout, self(), ?MODULE), + State#state{timeout_ref=TRef}. + +%% @private +-spec handler_loop(#state{}, #http_req{}, any(), binary()) -> closed. +handler_loop(State=#state{messages={OK, Closed, Error}, timeout_ref=TRef}, + 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}); + {timeout, TRef, ?MODULE} -> + websocket_close(State, Req, HandlerState, {normal, timeout}); + {timeout, OlderTRef, ?MODULE} when is_reference(OlderTRef) -> + handler_loop(State, Req, HandlerState, SoFar); + Message -> + handler_call(State, Req, HandlerState, + SoFar, websocket_info, Message, fun handler_before_loop/4) + end. + +-spec websocket_data(#state{}, #http_req{}, any(), binary()) -> closed. +%% No more data. +websocket_data(State, Req, HandlerState, <<>>) -> + handler_before_loop(State, Req, HandlerState, <<>>); +%% hixie-76 close frame. +websocket_data(State=#state{version=0}, Req, HandlerState, + << 255, 0, _Rest/binary >>) -> + websocket_close(State, Req, HandlerState, {normal, closed}); +%% hixie-76 data frame. We only support the frame type 0, same as the specs. +websocket_data(State=#state{version=0, eop=EOP}, Req, HandlerState, + Data = << 0, _/binary >>) -> + case binary:match(Data, EOP) of + {Pos, 1} -> + Pos2 = Pos - 1, + << 0, Payload:Pos2/binary, 255, Rest/bits >> = Data, + handler_call(State, Req, HandlerState, + Rest, websocket_handle, {text, Payload}, fun websocket_data/4); + nomatch -> + %% @todo We probably should allow limiting frame length. + handler_before_loop(State, Req, HandlerState, Data) + end; +%% incomplete hybi data frame. +websocket_data(State=#state{version=Version}, Req, HandlerState, Data) + when Version =/= 0, byte_size(Data) =:= 1 -> + handler_before_loop(State, Req, HandlerState, Data); +%% 7 bit payload length prefix exists +websocket_data(State, Req, HandlerState, + << Fin:1, Rsv:3, Opcode:4, Mask:1, PayloadLen:7, Rest/bits >> + = Data) when PayloadLen < 126 -> + websocket_data(State, Req, HandlerState, + Fin, Rsv, Opcode, Mask, PayloadLen, Rest, Data); +%% 7+16 bits payload length prefix exists +websocket_data(State, Req, HandlerState, + << Fin:1, Rsv:3, Opcode:4, Mask:1, 126:7, PayloadLen:16, Rest/bits >> + = Data) when PayloadLen > 125 -> + websocket_data(State, Req, HandlerState, + Fin, Rsv, Opcode, Mask, PayloadLen, Rest, Data); +%% 7+16 bits payload length prefix missing +websocket_data(State, Req, HandlerState, + << _Fin:1, _Rsv:3, _Opcode:4, _Mask:1, 126:7, Rest/bits >> + = Data) when byte_size(Rest) < 2 -> + handler_before_loop(State, Req, HandlerState, Data); +%% 7+64 bits payload length prefix exists +websocket_data(State, Req, HandlerState, + << Fin:1, Rsv:3, Opcode:4, Mask:1, 127:7, 0:1, PayloadLen:63, + Rest/bits >> = Data) when PayloadLen > 16#FFFF -> + websocket_data(State, Req, HandlerState, + Fin, Rsv, Opcode, Mask, PayloadLen, Rest, Data); +%% 7+64 bits payload length prefix missing +websocket_data(State, Req, HandlerState, + << _Fin:1, _Rsv:3, _Opcode:4, _Mask:1, 127:7, Rest/bits >> + = Data) when byte_size(Rest) < 8 -> + handler_before_loop(State, Req, HandlerState, Data); +%% invalid payload length prefix. +websocket_data(State, Req, HandlerState, _Data) -> + websocket_close(State, Req, HandlerState, {error, badframe}). + + +-spec websocket_data(#state{}, #http_req{}, any(), non_neg_integer(), + non_neg_integer(), non_neg_integer(), non_neg_integer(), + non_neg_integer(), binary(), binary()) -> closed. +%% A fragmented message MUST start a non-zero opcode. +websocket_data(State=#state{frag_state=undefined}, Req, HandlerState, + _Fin=0, _Rsv=0, _Opcode=0, _Mask, _PayloadLen, _Rest, _Buffer) -> + websocket_close(State, Req, HandlerState, {error, badframe}); +%% A control message MUST NOT be fragmented. +websocket_data(State, Req, HandlerState, _Fin=0, _Rsv=0, Opcode, _Mask, + _PayloadLen, _Rest, _Buffer) when Opcode >= 8 -> + websocket_close(State, Req, HandlerState, {error, badframe}); +%% The opcode is only included in the first message fragment. +websocket_data(State=#state{frag_state=undefined}, Req, HandlerState, + _Fin=0, _Rsv=0, Opcode, Mask, PayloadLen, Rest, Data) -> + websocket_before_unmask( + State#state{frag_state={nofin, Opcode}}, Req, HandlerState, + Data, Rest, 0, Mask, PayloadLen); +%% non-control opcode when expecting control message or next fragment. +websocket_data(State=#state{frag_state={nofin, _, _}}, Req, HandlerState, _Fin, + _Rsv=0, Opcode, _Mask, _Ln, _Rest, _Data) when Opcode > 0, Opcode < 8 -> + websocket_close(State, Req, HandlerState, {error, badframe}); +%% If the first message fragment was incomplete, retry unmasking. +websocket_data(State=#state{frag_state={nofin, Opcode}}, Req, HandlerState, + _Fin=0, _Rsv=0, Opcode, Mask, PayloadLen, Rest, Data) -> + websocket_before_unmask( + State#state{frag_state={nofin, Opcode}}, Req, HandlerState, + Data, Rest, 0, Mask, PayloadLen); +%% if the opcode is zero and the fin flag is zero, unmask and await next. +websocket_data(State=#state{frag_state={nofin, _Opcode, _Payloads}}, Req, + HandlerState, _Fin=0, _Rsv=0, _Opcode2=0, Mask, PayloadLen, Rest, + Data) -> + websocket_before_unmask( + State, Req, HandlerState, Data, Rest, 0, Mask, PayloadLen); +%% when the last fragment is seen. Update the fragmentation status. +websocket_data(State=#state{frag_state={nofin, Opcode, Payloads}}, Req, + HandlerState, _Fin=1, _Rsv=0, _Opcode=0, Mask, PayloadLen, Rest, + Data) -> + websocket_before_unmask( + State#state{frag_state={fin, Opcode, Payloads}}, + Req, HandlerState, Data, Rest, 0, Mask, PayloadLen); +%% control messages MUST NOT use 7+16 bits or 7+64 bits payload length prefixes +websocket_data(State, Req, HandlerState, _Fin, _Rsv, Opcode, _Mask, PayloadLen, + _Rest, _Data) when Opcode >= 8, PayloadLen > 125 -> + websocket_close(State, Req, HandlerState, {error, badframe}); +%% unfragmented message. unmask and dispatch the message. +websocket_data(State=#state{version=Version}, Req, HandlerState, _Fin=1, _Rsv=0, + Opcode, Mask, PayloadLen, Rest, Data) when Version =/= 0 -> + websocket_before_unmask( + State, Req, HandlerState, Data, Rest, Opcode, Mask, PayloadLen); +%% Something was wrong with the frame. Close the connection. +websocket_data(State, Req, HandlerState, _Fin, _Rsv, _Opcode, _Mask, + _PayloadLen, _Rest, _Data) -> + websocket_close(State, Req, HandlerState, {error, badframe}). + + +%% hybi routing depending on whether unmasking is needed. +-spec websocket_before_unmask(#state{}, #http_req{}, any(), binary(), + binary(), opcode(), 0 | 1, non_neg_integer() | undefined) -> closed. +websocket_before_unmask(State, Req, HandlerState, Data, + Rest, Opcode, Mask, PayloadLen) -> + case {Mask, PayloadLen} of + {0, 0} -> + websocket_dispatch(State, Req, HandlerState, Rest, Opcode, <<>>); + {1, N} when N + 4 > byte_size(Rest); N =:= undefined -> + %% @todo We probably should allow limiting frame length. + handler_before_loop(State, Req, HandlerState, Data); + {1, _N} -> + << MaskKey:32, Payload:PayloadLen/binary, Rest2/bits >> = Rest, + websocket_unmask(State, Req, HandlerState, Rest2, + Opcode, Payload, MaskKey) + end. + +%% hybi unmasking. +-spec websocket_unmask(#state{}, #http_req{}, any(), binary(), + opcode(), binary(), mask_key()) -> closed. +websocket_unmask(State, Req, HandlerState, RemainingData, + Opcode, Payload, MaskKey) -> + websocket_unmask(State, Req, HandlerState, RemainingData, + Opcode, Payload, MaskKey, <<>>). + +-spec websocket_unmask(#state{}, #http_req{}, any(), binary(), + opcode(), binary(), mask_key(), binary()) -> closed. +websocket_unmask(State, Req, HandlerState, RemainingData, + Opcode, << O:32, Rest/bits >>, MaskKey, Acc) -> + T = O bxor MaskKey, + websocket_unmask(State, Req, HandlerState, RemainingData, + Opcode, Rest, MaskKey, << Acc/binary, T:32 >>); +websocket_unmask(State, Req, HandlerState, RemainingData, + Opcode, << O:24 >>, MaskKey, Acc) -> + << MaskKey2:24, _:8 >> = << MaskKey:32 >>, + T = O bxor MaskKey2, + websocket_dispatch(State, Req, HandlerState, RemainingData, + Opcode, << Acc/binary, T:24 >>); +websocket_unmask(State, Req, HandlerState, RemainingData, + Opcode, << O:16 >>, MaskKey, Acc) -> + << MaskKey2:16, _:16 >> = << MaskKey:32 >>, + T = O bxor MaskKey2, + websocket_dispatch(State, Req, HandlerState, RemainingData, + Opcode, << Acc/binary, T:16 >>); +websocket_unmask(State, Req, HandlerState, RemainingData, + Opcode, << O:8 >>, MaskKey, Acc) -> + << MaskKey2:8, _:24 >> = << MaskKey:32 >>, + T = O bxor MaskKey2, + websocket_dispatch(State, Req, HandlerState, RemainingData, + Opcode, << Acc/binary, T:8 >>); +websocket_unmask(State, Req, HandlerState, RemainingData, + Opcode, <<>>, _MaskKey, Acc) -> + websocket_dispatch(State, Req, HandlerState, RemainingData, + Opcode, Acc). + +%% hybi dispatching. +-spec websocket_dispatch(#state{}, #http_req{}, any(), binary(), + opcode(), binary()) -> closed. +%% First frame of a fragmented message unmasked. Expect intermediate or last. +websocket_dispatch(State=#state{frag_state={nofin, Opcode}}, Req, HandlerState, + RemainingData, 0, Payload) -> + websocket_data(State#state{frag_state={nofin, Opcode, Payload}}, + Req, HandlerState, RemainingData); +%% Intermediate frame of a fragmented message unmasked. Add payload to buffer. +websocket_dispatch(State=#state{frag_state={nofin, Opcode, Payloads}}, Req, + HandlerState, RemainingData, 0, Payload) -> + websocket_data(State#state{frag_state={nofin, Opcode, + <<Payloads/binary, Payload/binary>>}}, Req, HandlerState, + RemainingData); +%% Last frame of a fragmented message unmasked. Dispatch to handler. +websocket_dispatch(State=#state{frag_state={fin, Opcode, Payloads}}, Req, + HandlerState, RemainingData, 0, Payload) -> + websocket_dispatch(State#state{frag_state=undefined}, Req, HandlerState, + RemainingData, Opcode, <<Payloads/binary, Payload/binary>>); +%% Text frame. +websocket_dispatch(State, Req, HandlerState, RemainingData, 1, Payload) -> + handler_call(State, Req, HandlerState, RemainingData, + websocket_handle, {text, Payload}, fun websocket_data/4); +%% Binary frame. +websocket_dispatch(State, Req, HandlerState, RemainingData, 2, Payload) -> + handler_call(State, Req, HandlerState, RemainingData, + websocket_handle, {binary, Payload}, fun websocket_data/4); +%% Close control frame. +%% @todo Handle the optional Payload. +websocket_dispatch(State, Req, HandlerState, _RemainingData, 8, _Payload) -> + websocket_close(State, Req, HandlerState, {normal, closed}); +%% Ping control frame. Send a pong back and forward the ping to the handler. +websocket_dispatch(State, Req=#http_req{socket=Socket, transport=Transport}, + HandlerState, RemainingData, 9, Payload) -> + Len = hybi_payload_length(byte_size(Payload)), + Transport:send(Socket, << 1:1, 0:3, 10:4, 0:1, Len/bits, Payload/binary >>), + handler_call(State, Req, HandlerState, RemainingData, + websocket_handle, {ping, Payload}, fun websocket_data/4); +%% Pong control frame. +websocket_dispatch(State, Req, HandlerState, RemainingData, 10, Payload) -> + handler_call(State, Req, HandlerState, RemainingData, + websocket_handle, {pong, Payload}, fun websocket_data/4). + +-spec handler_call(#state{}, #http_req{}, any(), binary(), + atom(), any(), fun()) -> closed. +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, Payload, Req2, HandlerState2} -> + websocket_send(Payload, State, Req2), + NextState(State, Req2, HandlerState2, RemainingData); + {reply, Payload, Req2, HandlerState2, hibernate} -> + websocket_send(Payload, State, Req2), + NextState(State#state{hibernate=true}, + Req2, HandlerState2, RemainingData); + {shutdown, Req2, HandlerState2} -> + websocket_close(State, Req2, HandlerState2, {normal, shutdown}) + catch Class:Reason -> + PLReq = lists:zip(record_info(fields, http_req), tl(tuple_to_list(Req))), + error_logger:error_msg( + "** Handler ~p terminating in ~p/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, Callback, Class, Reason, Message, Opts, + HandlerState, PLReq, erlang:get_stacktrace()]), + websocket_close(State, Req, HandlerState, {error, handler}) + end. + +-spec websocket_send(binary(), #state{}, #http_req{}) -> closed | ignore. +%% hixie-76 text frame. +websocket_send({text, Payload}, #state{version=0}, + #http_req{socket=Socket, transport=Transport}) -> + Transport:send(Socket, [0, Payload, 255]); +%% Ignore all unknown frame types for compatibility with hixie 76. +websocket_send(_Any, #state{version=0}, _Req) -> + ignore; +websocket_send({Type, Payload}, _State, + #http_req{socket=Socket, transport=Transport}) -> + Opcode = case Type of + text -> 1; + binary -> 2; + ping -> 9; + pong -> 10 + end, + Len = hybi_payload_length(iolist_size(Payload)), + Transport:send(Socket, [<< 1:1, 0:3, Opcode:4, 0:1, Len/bits >>, + Payload]). + +-spec websocket_close(#state{}, #http_req{}, any(), {atom(), atom()}) -> closed. +websocket_close(State=#state{version=0}, Req=#http_req{socket=Socket, + transport=Transport}, HandlerState, Reason) -> + Transport:send(Socket, << 255, 0 >>), + handler_terminate(State, Req, HandlerState, Reason); +%% @todo Send a Payload? Using Reason is usually good but we're quite careless. +websocket_close(State, Req=#http_req{socket=Socket, + transport=Transport}, HandlerState, Reason) -> + Transport:send(Socket, << 1:1, 0:3, 8:4, 0:8 >>), + handler_terminate(State, Req, HandlerState, Reason). + +-spec handler_terminate(#state{}, #http_req{}, + any(), atom() | {atom(), atom()}) -> closed. +handler_terminate(#state{handler=Handler, opts=Opts}, + Req, HandlerState, TerminateReason) -> + try + Handler:websocket_terminate(TerminateReason, Req, HandlerState) + catch Class:Reason -> + PLReq = lists:zip(record_info(fields, http_req), tl(tuple_to_list(Req))), + 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, PLReq, erlang:get_stacktrace()]) + end, + closed. + +%% hixie-76 specific. + +-spec hixie76_challenge(binary(), binary(), binary()) -> binary(). +hixie76_challenge(Key1, Key2, Key3) -> + IntKey1 = hixie76_key_to_integer(Key1), + IntKey2 = hixie76_key_to_integer(Key2), + erlang:md5(<< IntKey1:32, IntKey2:32, Key3/binary >>). + +-spec hixie76_key_to_integer(binary()) -> integer(). +hixie76_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 hixie76_location(atom(), binary(), inet:port_number(), + binary(), binary()) -> binary(). +hixie76_location(Protocol, Host, Port, Path, <<>>) -> + << (hixie76_location_protocol(Protocol))/binary, "://", Host/binary, + (hixie76_location_port(Protocol, Port))/binary, Path/binary>>; +hixie76_location(Protocol, Host, Port, Path, QS) -> + << (hixie76_location_protocol(Protocol))/binary, "://", Host/binary, + (hixie76_location_port(Protocol, Port))/binary, Path/binary, "?", QS/binary >>. + +-spec hixie76_location_protocol(atom()) -> binary(). +hixie76_location_protocol(ssl) -> <<"wss">>; +hixie76_location_protocol(_) -> <<"ws">>. + +%% @todo We should add a secure/0 function to transports +%% instead of relying on their name. +-spec hixie76_location_port(atom(), inet:port_number()) -> binary(). +hixie76_location_port(ssl, 443) -> + <<>>; +hixie76_location_port(tcp, 80) -> + <<>>; +hixie76_location_port(_, Port) -> + <<":", (list_to_binary(integer_to_list(Port)))/binary>>. + +%% hybi specific. + +-spec hybi_challenge(binary()) -> binary(). +hybi_challenge(Key) -> + Bin = << Key/binary, "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" >>, + base64:encode(crypto:sha(Bin)). + +-spec hybi_payload_length(0..16#7fffffffffffffff) + -> << _:7 >> | << _:23 >> | << _:71 >>. +hybi_payload_length(N) -> + case N of + N when N =< 125 -> << N:7 >>; + N when N =< 16#ffff -> << 126:7, N:16 >>; + N when N =< 16#7fffffffffffffff -> << 127:7, N:64 >> + end. + +%% Tests. + +-ifdef(TEST). + +hixie76_location_test() -> + ?assertEqual(<<"ws://localhost/path">>, + hixie76_location(tcp, <<"localhost">>, 80, <<"/path">>, <<>>)), + ?assertEqual(<<"ws://localhost:443/path">>, + hixie76_location(tcp, <<"localhost">>, 443, <<"/path">>, <<>>)), + ?assertEqual(<<"ws://localhost:8080/path">>, + hixie76_location(tcp, <<"localhost">>, 8080, <<"/path">>, <<>>)), + ?assertEqual(<<"ws://localhost:8080/path?dummy=2785">>, + hixie76_location(tcp, <<"localhost">>, 8080, <<"/path">>, <<"dummy=2785">>)), + ?assertEqual(<<"wss://localhost/path">>, + hixie76_location(ssl, <<"localhost">>, 443, <<"/path">>, <<>>)), + ?assertEqual(<<"wss://localhost:8443/path">>, + hixie76_location(ssl, <<"localhost">>, 8443, <<"/path">>, <<>>)), + ?assertEqual(<<"wss://localhost:8443/path?dummy=2785">>, + hixie76_location(ssl, <<"localhost">>, 8443, <<"/path">>, <<"dummy=2785">>)), + ok. + +-endif. |