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-module(mochiweb_websocket).
-author('lukasz.lalik@zadane.pl').
%% The MIT License (MIT)
%% Copyright (c) 2012 Zadane.pl sp. z o.o.
%% Permission is hereby granted, free of charge, to any person obtaining a copy
%% of this software and associated documentation files (the "Software"), to deal
%% in the Software without restriction, including without limitation the rights
%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
%% copies of the Software, and to permit persons to whom the Software is
%% furnished to do so, subject to the following conditions:
%% The above copyright notice and this permission notice shall be included in
%% all copies or substantial portions of the Software.
%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
%% THE SOFTWARE.
%% @doc Websockets module for Mochiweb. Based on Misultin websockets module.
-export([loop/5, request/5, upgrade_connection/2]).
-export([send/3]).
-ifdef(TEST).
-export([hixie_handshake/7, make_handshake/1,
parse_hixie_frames/2, parse_hybi_frames/3]).
-endif.
loop(Socket, Body, State, WsVersion, ReplyChannel) ->
ok =
mochiweb_socket:exit_if_closed(mochiweb_socket:setopts(Socket,
[{packet, 0},
{active,
once}])),
proc_lib:hibernate(?MODULE, request,
[Socket, Body, State, WsVersion, ReplyChannel]).
request(Socket, Body, State, WsVersion, ReplyChannel) ->
receive
{tcp_closed, _} ->
mochiweb_socket:close(Socket), exit(normal);
{ssl_closed, _} ->
mochiweb_socket:close(Socket), exit(normal);
{tcp_error, _, _} ->
mochiweb_socket:close(Socket), exit(normal);
{Proto, _, WsFrames}
when Proto =:= tcp orelse Proto =:= ssl ->
case parse_frames(WsVersion, WsFrames, Socket) of
close -> mochiweb_socket:close(Socket), exit(normal);
error -> mochiweb_socket:close(Socket), exit(normal);
Payload ->
NewState = call_body(Body, Payload, State,
ReplyChannel),
loop(Socket, Body, NewState, WsVersion, ReplyChannel)
end;
_ -> mochiweb_socket:close(Socket), exit(normal)
end.
call_body({M, F, A}, Payload, State, ReplyChannel) ->
erlang:apply(M, F, [Payload, State, ReplyChannel | A]);
call_body({M, F}, Payload, State, ReplyChannel) ->
M:F(Payload, State, ReplyChannel);
call_body(Body, Payload, State, ReplyChannel) ->
Body(Payload, State, ReplyChannel).
send(Socket, Payload, hybi) ->
Prefix = <<1:1, 0:3, 1:4,
(payload_length(iolist_size(Payload)))/binary>>,
mochiweb_socket:send(Socket, [Prefix, Payload]);
send(Socket, Payload, hixie) ->
mochiweb_socket:send(Socket, [0, Payload, 255]).
upgrade_connection({ReqM, _} = Req, Body) ->
case make_handshake(Req) of
{Version, Response} ->
ReqM:respond(Response, Req),
Socket = ReqM:get(socket, Req),
ReplyChannel = fun (Payload) ->
(?MODULE):send(Socket, Payload, Version)
end,
Reentry = fun (State) ->
(?MODULE):loop(Socket, Body, State, Version,
ReplyChannel)
end,
{Reentry, ReplyChannel};
_ ->
mochiweb_socket:close(ReqM:get(socket, Req)),
exit(normal)
end.
make_handshake({ReqM, _} = Req) ->
SecKey = ReqM:get_header_value("sec-websocket-key",
Req),
Sec1Key = ReqM:get_header_value("Sec-WebSocket-Key1",
Req),
Sec2Key = ReqM:get_header_value("Sec-WebSocket-Key2",
Req),
Origin = ReqM:get_header_value(origin, Req),
if SecKey =/= undefined -> hybi_handshake(SecKey);
Sec1Key =/= undefined andalso Sec2Key =/= undefined ->
Host = ReqM:get_header_value("Host", Req),
Path = ReqM:get(path, Req),
Body = ReqM:recv(8, Req),
Scheme = scheme(Req),
hixie_handshake(Scheme, Host, Path, Sec1Key, Sec2Key,
Body, Origin);
true -> error
end.
hybi_handshake(SecKey) ->
BinKey = list_to_binary(SecKey),
Bin = <<BinKey/binary,
"258EAFA5-E914-47DA-95CA-C5AB0DC85B11">>,
Challenge = base64:encode(crypto:hash(sha, Bin)),
Response = {101,
[{"Connection", "Upgrade"}, {"Upgrade", "websocket"},
{"Sec-Websocket-Accept", Challenge}],
""},
{hybi, Response}.
scheme(Req) ->
case mochiweb_request:get(scheme, Req) of
http -> "ws://";
https -> "wss://"
end.
hixie_handshake(Scheme, Host, Path, Key1, Key2, Body,
Origin) ->
Ikey1 = [D || D <- Key1, $0 =< D, D =< $9],
Ikey2 = [D || D <- Key2, $0 =< D, D =< $9],
Blank1 = length([D || D <- Key1, D =:= 32]),
Blank2 = length([D || D <- Key2, D =:= 32]),
Part1 = erlang:list_to_integer(Ikey1) div Blank1,
Part2 = erlang:list_to_integer(Ikey2) div Blank2,
Ckey = <<Part1:4/big-unsigned-integer-unit:8,
Part2:4/big-unsigned-integer-unit:8, Body/binary>>,
Challenge = erlang:md5(Ckey),
Location = lists:concat([Scheme, Host, Path]),
Response = {101,
[{"Upgrade", "WebSocket"}, {"Connection", "Upgrade"},
{"Sec-WebSocket-Origin", Origin},
{"Sec-WebSocket-Location", Location}],
Challenge},
{hixie, Response}.
parse_frames(hybi, Frames, Socket) ->
try parse_hybi_frames(Socket, Frames, []) of
Parsed -> process_frames(Parsed, [])
catch
_:_ -> error
end;
parse_frames(hixie, Frames, _Socket) ->
try parse_hixie_frames(Frames, []) of
Payload -> Payload
catch
_:_ -> error
end.
%%
%% Websockets internal functions for RFC6455 and hybi draft
%%
process_frames([], Acc) -> lists:reverse(Acc);
process_frames([{Opcode, Payload} | Rest], Acc) ->
case Opcode of
8 -> close;
_ -> process_frames(Rest, [Payload | Acc])
end.
parse_hybi_frames(_, <<>>, Acc) -> lists:reverse(Acc);
parse_hybi_frames(S,
<<_Fin:1, _Rsv:3, Opcode:4, _Mask:1, PayloadLen:7,
MaskKey:4/binary, Payload:PayloadLen/binary-unit:8,
Rest/binary>>,
Acc)
when PayloadLen < 126 ->
Payload2 = hybi_unmask(Payload, MaskKey, <<>>),
parse_hybi_frames(S, Rest, [{Opcode, Payload2} | Acc]);
parse_hybi_frames(S,
<<_Fin:1, _Rsv:3, Opcode:4, _Mask:1, 126:7,
PayloadLen:16, MaskKey:4/binary,
Payload:PayloadLen/binary-unit:8, Rest/binary>>,
Acc) ->
Payload2 = hybi_unmask(Payload, MaskKey, <<>>),
parse_hybi_frames(S, Rest, [{Opcode, Payload2} | Acc]);
parse_hybi_frames(Socket,
<<_Fin:1, _Rsv:3, _Opcode:4, _Mask:1, 126:7,
_PayloadLen:16, _MaskKey:4/binary, _/binary-unit:8>> =
PartFrame,
Acc) ->
ok =
mochiweb_socket:exit_if_closed(mochiweb_socket:setopts(Socket,
[{packet, 0},
{active,
once}])),
receive
{tcp_closed, _} ->
mochiweb_socket:close(Socket), exit(normal);
{ssl_closed, _} ->
mochiweb_socket:close(Socket), exit(normal);
{tcp_error, _, _} ->
mochiweb_socket:close(Socket), exit(normal);
{Proto, _, Continuation}
when Proto =:= tcp orelse Proto =:= ssl ->
parse_hybi_frames(Socket,
<<PartFrame/binary, Continuation/binary>>, Acc);
_ -> mochiweb_socket:close(Socket), exit(normal)
after 5000 ->
mochiweb_socket:close(Socket), exit(normal)
end;
parse_hybi_frames(S,
<<_Fin:1, _Rsv:3, Opcode:4, _Mask:1, 127:7, 0:1,
PayloadLen:63, MaskKey:4/binary,
Payload:PayloadLen/binary-unit:8, Rest/binary>>,
Acc) ->
Payload2 = hybi_unmask(Payload, MaskKey, <<>>),
parse_hybi_frames(S, Rest, [{Opcode, Payload2} | Acc]).
%% Unmasks RFC 6455 message
hybi_unmask(<<O:32, Rest/bits>>, MaskKey, Acc) ->
<<MaskKey2:32>> = MaskKey,
hybi_unmask(Rest, MaskKey,
<<Acc/binary, (O bxor MaskKey2):32>>);
hybi_unmask(<<O:24>>, MaskKey, Acc) ->
<<MaskKey2:24, _:8>> = MaskKey,
<<Acc/binary, (O bxor MaskKey2):24>>;
hybi_unmask(<<O:16>>, MaskKey, Acc) ->
<<MaskKey2:16, _:16>> = MaskKey,
<<Acc/binary, (O bxor MaskKey2):16>>;
hybi_unmask(<<O:8>>, MaskKey, Acc) ->
<<MaskKey2:8, _:24>> = MaskKey,
<<Acc/binary, (O bxor MaskKey2):8>>;
hybi_unmask(<<>>, _MaskKey, Acc) -> Acc.
payload_length(N) ->
case N of
N when N =< 125 -> <<N>>;
N when N =< 65535 -> <<126, N:16>>;
N when N =< 9223372036854775807 -> <<127, N:64>>
end.
%%
%% Websockets internal functions for hixie-76 websocket version
%%
parse_hixie_frames(<<>>, Frames) ->
lists:reverse(Frames);
parse_hixie_frames(<<0, T/binary>>, Frames) ->
{Frame, Rest} = parse_hixie(T, <<>>),
parse_hixie_frames(Rest, [Frame | Frames]).
parse_hixie(<<255, Rest/binary>>, Buffer) ->
{Buffer, Rest};
parse_hixie(<<H, T/binary>>, Buffer) ->
parse_hixie(T, <<Buffer/binary, H>>).