%% Copyright (c) 2011-2013, 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 implementation. %% %% Cowboy supports versions 7 through 17 of the Websocket drafts. %% It also supports RFC6455, the proposed standard for Websocket. -module(cowboy_websocket). %% API. -export([upgrade/4]). %% Internal. -export([handler_loop/4]). -type frame() :: close | ping | pong | {text | binary | close | ping | pong, binary()} | {close, 1000..4999, binary()}. -export_type([frame/0]). -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, { env :: cowboy_middleware:env(), socket = undefined :: inet:socket(), transport = undefined :: module(), handler :: module(), handler_opts :: any(), key = undefined :: undefined | binary(), timeout = infinity :: timeout(), timeout_ref = undefined :: undefined | reference(), messages = undefined :: undefined | {atom(), atom(), atom()}, hibernate = false :: boolean(), frag_state = undefined :: frag_state() }). %% @doc Upgrade an 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(Req, Env, module(), any()) -> {ok, Req, Env} | {error, 400, Req} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(), Env::cowboy_middleware:env(). upgrade(Req, Env, Handler, HandlerOpts) -> {_, ListenerPid} = lists:keyfind(listener, 1, Env), ranch_listener:remove_connection(ListenerPid), [Socket, Transport] = cowboy_req:get([socket, transport], Req), State = #state{env=Env, socket=Socket, transport=Transport, handler=Handler, handler_opts=HandlerOpts}, case catch websocket_upgrade(State, Req) of {ok, State2, Req2} -> handler_init(State2, Req2); {'EXIT', _Reason} -> upgrade_error(Req, Env) end. -spec websocket_upgrade(#state{}, Req) -> {ok, #state{}, Req} when Req::cowboy_req:req(). websocket_upgrade(State, Req) -> {ok, 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. {ok, [<<"websocket">>], Req3} = cowboy_req:parse_header(<<"upgrade">>, Req2), {Version, Req4} = cowboy_req:header(<<"sec-websocket-version">>, Req3), IntVersion = list_to_integer(binary_to_list(Version)), true = (IntVersion =:= 7) orelse (IntVersion =:= 8) orelse (IntVersion =:= 13), {Key, Req5} = cowboy_req:header(<<"sec-websocket-key">>, Req4), false = Key =:= undefined, {ok, State#state{key=Key}, cowboy_req:set_meta(websocket_version, IntVersion, Req5)}. -spec handler_init(#state{}, Req) -> {ok, Req, cowboy_middleware:env()} | {error, 400, Req} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). handler_init(State=#state{env=Env, transport=Transport, handler=Handler, handler_opts=HandlerOpts}, Req) -> try Handler:websocket_init(Transport:name(), Req, HandlerOpts) 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} -> cowboy_req:ensure_response(Req2, 400), {ok, Req2, [{result, closed}|Env]} catch Class:Reason -> error_logger:error_msg( "** Cowboy handler ~p terminating in ~p/~p~n" " for the reason ~p:~p~n** Options were ~p~n" "** Request was ~p~n** Stacktrace: ~p~n~n", [Handler, websocket_init, 3, Class, Reason, HandlerOpts, cowboy_req:to_list(Req),erlang:get_stacktrace()]), upgrade_error(Req, Env) end. -spec upgrade_error(Req, Env) -> {ok, Req, Env} | {error, 400, Req} when Req::cowboy_req:req(), Env::cowboy_middleware:env(). upgrade_error(Req, Env) -> receive {cowboy_req, resp_sent} -> {ok, Req, [{result, closed}|Env]} after 0 -> {error, 400, Req} end. -spec websocket_handshake(#state{}, Req, any()) -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). websocket_handshake(State=#state{transport=Transport, key=Key}, Req, HandlerState) -> Challenge = base64:encode(crypto:sha( << Key/binary, "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" >>)), {ok, Req2} = cowboy_req:upgrade_reply( 101, [{<<"upgrade">>, <<"websocket">>}, {<<"sec-websocket-accept">>, Challenge}], Req), %% Flush the resp_sent message before moving on. receive {cowboy_req, resp_sent} -> ok after 0 -> ok end, State2 = handler_loop_timeout(State), handler_before_loop(State2#state{key=undefined, messages=Transport:messages()}, Req2, HandlerState, <<>>). -spec handler_before_loop(#state{}, Req, any(), binary()) -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). handler_before_loop(State=#state{ socket=Socket, transport=Transport, hibernate=true}, Req, HandlerState, SoFar) -> Transport:setopts(Socket, [{active, once}]), {suspend, ?MODULE, handler_loop, [State#state{hibernate=false}, Req, HandlerState, SoFar]}; handler_before_loop(State=#state{socket=Socket, transport=Transport}, Req, HandlerState, SoFar) -> Transport:setopts(Socket, [{active, once}]), handler_loop(State, 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{}, Req, any(), binary()) -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). handler_loop(State=#state{ socket=Socket, messages={OK, Closed, Error}, timeout_ref=TRef}, Req, HandlerState, SoFar) -> receive {OK, Socket, Data} -> State2 = handler_loop_timeout(State), websocket_data(State2, 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{}, Req, any(), binary()) -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). %% No more data. websocket_data(State, Req, HandlerState, <<>>) -> handler_before_loop(State, Req, HandlerState, <<>>); %% Incomplete. websocket_data(State, Req, HandlerState, Data) when 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{}, Req, any(), non_neg_integer(), non_neg_integer(), non_neg_integer(), non_neg_integer(), non_neg_integer(), binary(), binary()) -> {ok, Req, cowboy_middleware:env()} when Req::cowboy_req:req(). %% 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, Req, HandlerState, _Fin=1, _Rsv=0, Opcode, Mask, PayloadLen, Rest, Data) -> 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}). %% Routing depending on whether unmasking is needed. -spec websocket_before_unmask(#state{}, Req, any(), binary(), binary(), opcode(), 0 | 1, non_neg_integer() | undefined) -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). 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. %% Unmasking. -spec websocket_unmask(#state{}, Req, any(), binary(), opcode(), binary(), mask_key()) -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). websocket_unmask(State, Req, HandlerState, RemainingData, Opcode, Payload, MaskKey) -> websocket_unmask(State, Req, HandlerState, RemainingData, Opcode, Payload, MaskKey, <<>>). -spec websocket_unmask(#state{}, Req, any(), binary(), opcode(), binary(), mask_key(), binary()) -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). 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). %% Dispatching. -spec websocket_dispatch(#state{}, Req, any(), binary(), opcode(), binary()) -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). %% 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, <>}}, 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, <>); %% 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=#state{socket=Socket, transport=Transport}, Req, HandlerState, RemainingData, 9, Payload) -> Len = payload_length_to_binary(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{}, Req, any(), binary(), atom(), any(), fun()) -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). handler_call(State=#state{handler=Handler, handler_opts=HandlerOpts}, 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} when is_tuple(Payload) -> case websocket_send(Payload, State) of ok -> State2 = handler_loop_timeout(State), NextState(State2, Req2, HandlerState2, RemainingData); shutdown -> handler_terminate(State, Req2, HandlerState, {normal, shutdown}); {error, _} = Error -> handler_terminate(State, Req2, HandlerState2, Error) end; {reply, Payload, Req2, HandlerState2, hibernate} when is_tuple(Payload) -> case websocket_send(Payload, State) of ok -> State2 = handler_loop_timeout(State), NextState(State2#state{hibernate=true}, Req2, HandlerState2, RemainingData); shutdown -> handler_terminate(State, Req2, HandlerState, {normal, shutdown}); {error, _} = Error -> handler_terminate(State, Req2, HandlerState2, Error) end; {reply, Payload, Req2, HandlerState2} when is_list(Payload) -> case websocket_send_many(Payload, State) of ok -> State2 = handler_loop_timeout(State), NextState(State2, Req2, HandlerState2, RemainingData); shutdown -> handler_terminate(State, Req2, HandlerState, {normal, shutdown}); {error, _} = Error -> handler_terminate(State, Req2, HandlerState2, Error) end; {reply, Payload, Req2, HandlerState2, hibernate} when is_list(Payload) -> case websocket_send_many(Payload, State) of ok -> State2 = handler_loop_timeout(State), NextState(State2#state{hibernate=true}, Req2, HandlerState2, RemainingData); shutdown -> handler_terminate(State, Req2, HandlerState, {normal, shutdown}); {error, _} = Error -> handler_terminate(State, Req2, HandlerState2, Error) end; {shutdown, Req2, HandlerState2} -> websocket_close(State, Req2, HandlerState2, {normal, shutdown}) catch Class:Reason -> PLReq = cowboy_req:to_list(Req), error_logger:error_msg( "** Cowboy handler ~p terminating in ~p/~p~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, 3, Class, Reason, Message, HandlerOpts, HandlerState, PLReq, erlang:get_stacktrace()]), websocket_close(State, Req, HandlerState, {error, handler}) end. websocket_opcode(text) -> 1; websocket_opcode(binary) -> 2; websocket_opcode(close) -> 8; websocket_opcode(ping) -> 9; websocket_opcode(pong) -> 10. -spec websocket_send(frame(), #state{}) -> ok | shutdown | {error, atom()}. websocket_send(Type, #state{socket=Socket, transport=Transport}) when Type =:= close -> Opcode = websocket_opcode(Type), case Transport:send(Socket, << 1:1, 0:3, Opcode:4, 0:8 >>) of ok -> shutdown; Error -> Error end; websocket_send(Type, #state{socket=Socket, transport=Transport}) when Type =:= ping; Type =:= pong -> Opcode = websocket_opcode(Type), Transport:send(Socket, << 1:1, 0:3, Opcode:4, 0:8 >>); websocket_send({close, Payload}, State) -> websocket_send({close, 1000, Payload}, State); websocket_send({Type = close, StatusCode, Payload}, #state{ socket=Socket, transport=Transport}) -> Opcode = websocket_opcode(Type), Len = 2 + iolist_size(Payload), %% Control packets must not be > 125 in length. true = Len =< 125, BinLen = payload_length_to_binary(Len), Transport:send(Socket, [<< 1:1, 0:3, Opcode:4, 0:1, BinLen/bits, StatusCode:16 >>, Payload]), shutdown; websocket_send({Type, Payload}, #state{socket=Socket, transport=Transport}) -> Opcode = websocket_opcode(Type), Len = iolist_size(Payload), %% Control packets must not be > 125 in length. true = if Type =:= ping; Type =:= pong -> Len =< 125; true -> true end, BinLen = payload_length_to_binary(Len), Transport:send(Socket, [<< 1:1, 0:3, Opcode:4, 0:1, BinLen/bits >>, Payload]). -spec websocket_send_many([frame()], #state{}) -> ok | shutdown | {error, atom()}. websocket_send_many([], _) -> ok; websocket_send_many([Frame|Tail], State) -> case websocket_send(Frame, State) of ok -> websocket_send_many(Tail, State); shutdown -> shutdown; Error -> Error end. -spec websocket_close(#state{}, Req, any(), {atom(), atom()}) -> {ok, Req, cowboy_middleware:env()} when Req::cowboy_req:req(). websocket_close(State=#state{socket=Socket, transport=Transport}, Req, HandlerState, Reason) -> Transport:send(Socket, << 1:1, 0:3, 8:4, 0:8 >>), handler_terminate(State, Req, HandlerState, Reason). -spec handler_terminate(#state{}, Req, any(), atom() | {atom(), atom()}) -> {ok, Req, cowboy_middleware:env()} when Req::cowboy_req:req(). handler_terminate(#state{env=Env, handler=Handler, handler_opts=HandlerOpts}, Req, HandlerState, TerminateReason) -> try Handler:websocket_terminate(TerminateReason, Req, HandlerState) catch Class:Reason -> PLReq = cowboy_req:to_list(Req), error_logger:error_msg( "** Cowboy handler ~p terminating in ~p/~p~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, websocket_terminate, 3, Class, Reason, TerminateReason, HandlerOpts, HandlerState, PLReq, erlang:get_stacktrace()]) end, {ok, Req, [{result, closed}|Env]}. -spec payload_length_to_binary(0..16#7fffffffffffffff) -> << _:7 >> | << _:23 >> | << _:71 >>. payload_length_to_binary(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.