%%%----------------------------------------------------------------------
%%% File : ejabberd_websocket.erl
%%% Author : Eric Cestari <ecestari@process-one.net>
%%% Purpose : XMPP Websocket support
%%% Created : 09-10-2010 by Eric Cestari <ecestari@process-one.net>
%%%
%%% Some code lifted from MISULTIN - WebSocket misultin_websocket.erl - >-|-|-(°>
%%% (http://github.com/ostinelli/misultin/blob/master/src/misultin_websocket.erl)
%%% Copyright (C) 2010, Roberto Ostinelli <roberto@ostinelli.net>, Joe Armstrong.
%%% All rights reserved.
%%%
%%% Code portions from Joe Armstrong have been originally taken under MIT license at the address:
%%% <http://armstrongonsoftware.blogspot.com/2009/12/comet-is-dead-long-live-websockets.html>
%%%
%%% BSD License
%%%
%%% Redistribution and use in source and binary forms, with or without modification, are permitted provided
%%% that the following conditions are met:
%%%
%%% * Redistributions of source code must retain the above copyright notice, this list of conditions and the
%%% following disclaimer.
%%% * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
%%% the following disclaimer in the documentation and/or other materials provided with the distribution.
%%% * Neither the name of the authors nor the names of its contributors may be used to endorse or promote
%%% products derived from this software without specific prior written permission.
%%%
%%% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
%%% WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
%%% PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
%%% ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
%%% TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
%%% HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
%%% NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
%%% POSSIBILITY OF SUCH DAMAGE.
%%% ==========================================================================================================
%%% ejabberd, Copyright (C) 2002-2015 ProcessOne
%%%----------------------------------------------------------------------
-module(ejabberd_websocket).
-protocol({rfc, 6455}).
-author('ecestari@process-one.net').
-export([check/2, socket_handoff/8]).
-include("ejabberd.hrl").
-include("logger.hrl").
-include("jlib.hrl").
-include("ejabberd_http.hrl").
-define(CT_XML, {<<"Content-Type">>, <<"text/xml; charset=utf-8">>}).
-define(CT_PLAIN, {<<"Content-Type">>, <<"text/plain">>}).
-define(AC_ALLOW_ORIGIN, {<<"Access-Control-Allow-Origin">>, <<"*">>}).
-define(AC_ALLOW_METHODS, {<<"Access-Control-Allow-Methods">>, <<"GET, OPTIONS">>}).
-define(AC_ALLOW_HEADERS, {<<"Access-Control-Allow-Headers">>, <<"Content-Type">>}).
-define(AC_MAX_AGE, {<<"Access-Control-Max-Age">>, <<"86400">>}).
-define(OPTIONS_HEADER, [?CT_PLAIN, ?AC_ALLOW_ORIGIN, ?AC_ALLOW_METHODS,
?AC_ALLOW_HEADERS, ?AC_MAX_AGE]).
-define(HEADER, [?CT_XML, ?AC_ALLOW_ORIGIN, ?AC_ALLOW_HEADERS]).
check(_Path, Headers) ->
RequiredHeaders = [{'Upgrade', <<"websocket">>},
{'Connection', ignore}, {'Host', ignore},
{<<"Sec-Websocket-Key">>, ignore},
{<<"Sec-Websocket-Version">>, <<"13">>}],
F = fun ({Tag, Val}) ->
case lists:keyfind(Tag, 1, Headers) of
false -> true; % header not found, keep in list
{_, HVal} ->
case Val of
ignore -> false; % ignore value -> ok, remove from list
_ ->
% expected value -> ok, remove from list (false)
% value is different, keep in list (true)
str:to_lower(HVal) /= Val
end
end
end,
case lists:filter(F, RequiredHeaders) of
[] -> true;
_MissingHeaders -> false
end.
socket_handoff(LocalPath, #request{method = 'GET', ip = IP, q = Q, path = Path,
headers = Headers, host = Host, port = Port},
Socket, SockMod, Buf, _Opts, HandlerModule, InfoMsgFun) ->
case check(LocalPath, Headers) of
true ->
WS = #ws{socket = Socket,
sockmod = SockMod,
ip = IP,
q = Q,
host = Host,
port = Port,
path = Path,
headers = Headers,
local_path = LocalPath,
buf = Buf},
connect(WS, HandlerModule);
_ ->
{200, ?HEADER, InfoMsgFun()}
end;
socket_handoff(_, #request{method = 'OPTIONS'}, _, _, _, _, _, _) ->
{200, ?OPTIONS_HEADER, []};
socket_handoff(_, #request{method = 'HEAD'}, _, _, _, _, _, _) ->
{200, ?HEADER, []};
socket_handoff(_, _, _, _, _, _, _, _) ->
{400, ?HEADER, #xmlel{name = <<"h1">>,
children = [{xmlcdata, <<"400 Bad Request">>}]}}.
connect(#ws{socket = Socket, sockmod = SockMod} = Ws, WsLoop) ->
{NewWs, HandshakeResponse} = handshake(Ws),
SockMod:send(Socket, HandshakeResponse),
?DEBUG("Sent handshake response : ~p",
[HandshakeResponse]),
Ws0 = {Ws, self()},
{ok, WsHandleLoopPid} = WsLoop:start_link(Ws0),
erlang:monitor(process, WsHandleLoopPid),
case NewWs#ws.buf of
<<>> ->
ok;
Data ->
self() ! {raw, Socket, Data}
end,
% set opts
case SockMod of
gen_tcp ->
inet:setopts(Socket, [{packet, 0}, {active, true}]);
_ ->
SockMod:setopts(Socket, [{packet, 0}, {active, true}])
end,
ws_loop(none, Socket, WsHandleLoopPid, SockMod).
handshake(#ws{headers = Headers} = State) ->
{_, Key} = lists:keyfind(<<"Sec-Websocket-Key">>, 1,
Headers),
SubProtocolHeader = case find_subprotocol(Headers) of
false ->
[];
V ->
[<<"Sec-Websocket-Protocol:">>, V, <<"\r\n">>]
end,
Hash = jlib:encode_base64(
p1_sha:sha1(<<Key/binary, "258EAFA5-E914-47DA-95CA-C5AB0DC85B11">>)),
{State, [<<"HTTP/1.1 101 Switching Protocols\r\n">>,
<<"Upgrade: websocket\r\n">>,
<<"Connection: Upgrade\r\n">>,
SubProtocolHeader,
<<"Sec-WebSocket-Accept: ">>, Hash, <<"\r\n\r\n">>]}.
find_subprotocol(Headers) ->
case lists:keysearch(<<"Sec-Websocket-Protocol">>, 1, Headers) of
false ->
case lists:keysearch(<<"Websocket-Protocol">>, 1, Headers) of
false ->
false;
{value, {_, Protocol2}} ->
Protocol2
end;
{value, {_, Protocol}} ->
Protocol
end.
ws_loop(FrameInfo, Socket, WsHandleLoopPid, SocketMode) ->
receive
{DataType, _Socket, Data} when DataType =:= tcp orelse DataType =:= raw ->
case handle_data(DataType, FrameInfo, Data, Socket, WsHandleLoopPid, SocketMode) of
{error, Error} ->
?DEBUG("tls decode error ~p", [Error]),
websocket_close(Socket, WsHandleLoopPid, SocketMode, 1002); % protocol error
{NewFrameInfo, ToSend} ->
lists:foreach(fun(Pkt) -> SocketMode:send(Socket, Pkt)
end, ToSend),
ws_loop(NewFrameInfo, Socket, WsHandleLoopPid, SocketMode)
end;
{tcp_closed, _Socket} ->
?DEBUG("tcp connection was closed, exit", []),
websocket_close(Socket, WsHandleLoopPid, SocketMode, 0);
{'DOWN', Ref, process, WsHandleLoopPid, Reason} ->
Code = case Reason of
normal ->
1000; % normal close
_ ->
?ERROR_MSG("linked websocket controlling loop crashed "
"with reason: ~p",
[Reason]),
1011 % internal error
end,
erlang:demonitor(Ref),
websocket_close(Socket, WsHandleLoopPid, SocketMode, Code);
{send, Data} ->
SocketMode:send(Socket, encode_frame(Data, 1)),
ws_loop(FrameInfo, Socket, WsHandleLoopPid,
SocketMode);
{ping, Data} ->
SocketMode:send(Socket, encode_frame(Data, 9)),
ws_loop(FrameInfo, Socket, WsHandleLoopPid,
SocketMode);
shutdown ->
?DEBUG("shutdown request received, closing websocket "
"with pid ~p",
[self()]),
websocket_close(Socket, WsHandleLoopPid, SocketMode, 1001); % going away
_Ignored ->
?WARNING_MSG("received unexpected message, ignoring: ~p",
[_Ignored]),
ws_loop(FrameInfo, Socket, WsHandleLoopPid,
SocketMode)
end.
encode_frame(Data, Opcode) ->
case byte_size(Data) of
S1 when S1 < 126 ->
<<1:1, 0:3, Opcode:4, 0:1, S1:7, Data/binary>>;
S2 when S2 < 65536 ->
<<1:1, 0:3, Opcode:4, 0:1, 126:7, S2:16, Data/binary>>;
S3 ->
<<1:1, 0:3, Opcode:4, 0:1, 127:7, S3:64, Data/binary>>
end.
-record(frame_info,
{mask = none, offset = 0, left, final_frame = true,
opcode, unprocessed = <<>>, unmasked = <<>>,
unmasked_msg = <<>>}).
decode_header(<<Final:1, _:3, Opcode:4, 0:1,
Len:7, Data/binary>>)
when Len < 126 ->
{Len, Final, Opcode, none, Data};
decode_header(<<Final:1, _:3, Opcode:4, 0:1,
126:7, Len:16/integer, Data/binary>>) ->
{Len, Final, Opcode, none, Data};
decode_header(<<Final:1, _:3, Opcode:4, 0:1,
127:7, Len:64/integer, Data/binary>>) ->
{Len, Final, Opcode, none, Data};
decode_header(<<Final:1, _:3, Opcode:4, 1:1,
Len:7, Mask:4/binary, Data/binary>>)
when Len < 126 ->
{Len, Final, Opcode, Mask, Data};
decode_header(<<Final:1, _:3, Opcode:4, 1:1,
126:7, Len:16/integer, Mask:4/binary, Data/binary>>) ->
{Len, Final, Opcode, Mask, Data};
decode_header(<<Final:1, _:3, Opcode:4, 1:1,
127:7, Len:64/integer, Mask:4/binary, Data/binary>>) ->
{Len, Final, Opcode, Mask, Data};
decode_header(_) -> none.
unmask_int(Offset, _, <<>>, Acc) ->
{Acc, Offset};
unmask_int(0, <<M:32>> = Mask,
<<N:32, Rest/binary>>, Acc) ->
unmask_int(0, Mask, Rest,
<<Acc/binary, (M bxor N):32>>);
unmask_int(0, <<M:8, _/binary>> = Mask,
<<N:8, Rest/binary>>, Acc) ->
unmask_int(1, Mask, Rest,
<<Acc/binary, (M bxor N):8>>);
unmask_int(1, <<_:8, M:8, _/binary>> = Mask,
<<N:8, Rest/binary>>, Acc) ->
unmask_int(2, Mask, Rest,
<<Acc/binary, (M bxor N):8>>);
unmask_int(2, <<_:16, M:8, _/binary>> = Mask,
<<N:8, Rest/binary>>, Acc) ->
unmask_int(3, Mask, Rest,
<<Acc/binary, (M bxor N):8>>);
unmask_int(3, <<_:24, M:8>> = Mask,
<<N:8, Rest/binary>>, Acc) ->
unmask_int(0, Mask, Rest,
<<Acc/binary, (M bxor N):8>>).
unmask(#frame_info{mask = none} = State, Data) ->
{State, Data};
unmask(#frame_info{mask = Mask, offset = Offset} = State, Data) ->
{Unmasked, NewOffset} = unmask_int(Offset, Mask,
Data, <<>>),
{State#frame_info{offset = NewOffset}, Unmasked}.
process_frame(none, Data) ->
process_frame(#frame_info{}, Data);
process_frame(#frame_info{left = Left} = FrameInfo, <<>>) when Left > 0 ->
{FrameInfo, [], []};
process_frame(#frame_info{unprocessed = none,
unmasked = UnmaskedPre, left = Left} =
State,
Data)
when byte_size(Data) < Left ->
{State2, Unmasked} = unmask(State, Data),
{State2#frame_info{left = Left - byte_size(Data),
unmasked = [UnmaskedPre, Unmasked]},
[], []};
process_frame(#frame_info{unprocessed = none,
unmasked = UnmaskedPre, opcode = Opcode,
final_frame = Final, left = Left,
unmasked_msg = UnmaskedMsg} =
FrameInfo,
Data) ->
<<ToProcess:(Left)/binary, Unprocessed/binary>> = Data,
{_, Unmasked} = unmask(FrameInfo, ToProcess),
case Final of
true ->
{FrameInfo3, Recv, Send} = process_frame(#frame_info{},
Unprocessed),
case Opcode of
X when X < 3 ->
{FrameInfo3,
[iolist_to_binary([UnmaskedMsg, UnmaskedPre, Unmasked])
| Recv],
Send};
9 -> % Ping
Frame = encode_frame(Unprocessed, 10),
{FrameInfo3#frame_info{unmasked_msg = UnmaskedMsg}, [ping | Recv],
[Frame | Send]};
10 -> % Pong
{FrameInfo3, [pong | Recv], Send};
8 -> % Close
CloseCode = case Unmasked of
<<Code:16/integer-big, Message/binary>> ->
?DEBUG("WebSocket close op: ~p ~s",
[Code, Message]),
Code;
<<Code:16/integer-big>> ->
?DEBUG("WebSocket close op: ~p", [Code]),
Code;
_ ->
?DEBUG("WebSocket close op unknown: ~p",
[Unmasked]),
1000
end,
Frame = encode_frame(<<CloseCode:16/integer-big>>, 8),
{FrameInfo3#frame_info{unmasked_msg=UnmaskedMsg}, Recv,
[Frame | Send]};
_ ->
{FrameInfo3#frame_info{unmasked_msg = UnmaskedMsg}, Recv,
Send}
end;
_ ->
process_frame(#frame_info{unmasked_msg =
[UnmaskedMsg, UnmaskedPre,
Unmasked]},
Unprocessed)
end;
process_frame(#frame_info{unprocessed = <<>>} =
FrameInfo,
Data) ->
case decode_header(Data) of
none ->
{FrameInfo#frame_info{unprocessed = Data}, [], []};
{Len, Final, Opcode, Mask, Rest} ->
process_frame(FrameInfo#frame_info{mask = Mask,
final_frame = Final == 1,
left = Len, opcode = Opcode,
unprocessed = none},
Rest)
end;
process_frame(#frame_info{unprocessed =
UnprocessedPre} =
FrameInfo,
Data) ->
process_frame(FrameInfo#frame_info{unprocessed = <<>>},
<<UnprocessedPre/binary, Data/binary>>).
handle_data(tcp, FrameInfo, Data, Socket, WsHandleLoopPid, p1_tls) ->
case p1_tls:recv_data(Socket, Data) of
{ok, NewData} ->
handle_data_int(FrameInfo, NewData, Socket, WsHandleLoopPid, p1_tls);
{error, Error} ->
{error, Error}
end;
handle_data(_, FrameInfo, Data, Socket, WsHandleLoopPid, SockMod) ->
handle_data_int(FrameInfo, Data, Socket, WsHandleLoopPid, SockMod).
handle_data_int(FrameInfo, Data, _Socket, WsHandleLoopPid, _SocketMode) ->
{NewFrameInfo, Recv, Send} = process_frame(FrameInfo, Data),
lists:foreach(fun (El) ->
case El of
pong ->
WsHandleLoopPid ! pong;
ping ->
WsHandleLoopPid ! ping;
_ ->
WsHandleLoopPid ! {received, El}
end
end,
Recv),
{NewFrameInfo, Send}.
websocket_close(Socket, WsHandleLoopPid,
SocketMode, CloseCode) when CloseCode > 0 ->
Frame = encode_frame(<<CloseCode:16/integer-big>>, 8),
SocketMode:send(Socket, Frame),
websocket_close(Socket, WsHandleLoopPid, SocketMode, 0);
websocket_close(Socket, WsHandleLoopPid, SocketMode, _CloseCode) ->
WsHandleLoopPid ! closed,
SocketMode:close(Socket).
