aboutsummaryrefslogtreecommitdiffstats
path: root/src/cowboy_websocket.erl
diff options
context:
space:
mode:
Diffstat (limited to 'src/cowboy_websocket.erl')
-rw-r--r--src/cowboy_websocket.erl609
1 files changed, 609 insertions, 0 deletions
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.