1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
|
%% Copyright (c) 2011, 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 draft hixie-76 implementation.
%%
%% Known to work with the following browsers:
%% <ul>
%% <li>Mozilla Firefox 4.0 (disabled by default)</li>
%% <li>Google Chrome 6+</li>
%% <li>Safari 5.0.1+</li>
%% <li>Opera 11.00+ (disabled by default)</li>
%% </ul>
-module(cowboy_http_websocket).
-export([upgrade/3]). %% API.
-export([handler_loop/4]). %% Internal.
-include("include/http.hrl").
-include_lib("eunit/include/eunit.hrl").
-record(state, {
handler :: module(),
opts :: any(),
origin = undefined :: undefined | binary(),
challenge = undefined :: undefined | binary(),
timeout = infinity :: timeout(),
messages = undefined :: undefined | {atom(), atom(), atom()},
eop :: tuple(),
hibernate = false :: boolean()
}).
%% @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(module(), any(), #http_req{}) -> ok.
upgrade(Handler, Opts, Req) ->
EOP = binary:compile_pattern(<< 255 >>),
case catch websocket_upgrade(#state{handler=Handler, opts=Opts, eop=EOP}, 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) ->
{<<"Upgrade">>, Req2} = cowboy_http_req:header('Connection', Req),
{<<"WebSocket">>, Req3} = cowboy_http_req:header('Upgrade', Req2),
{Origin, Req4} = cowboy_http_req:header(<<"Origin">>, Req3),
{Key1, Req5} = cowboy_http_req:header(<<"Sec-Websocket-Key1">>, Req4),
{Key2, Req6} = cowboy_http_req:header(<<"Sec-Websocket-Key2">>, Req5),
false = lists:member(undefined, [Origin, Key1, Key2]),
{ok, Key3, Req7} = cowboy_http_req:body(8, Req6),
Challenge = challenge(Key1, Key2, Key3),
{ok, State#state{origin=Origin, challenge=Challenge}, Req7}.
-spec challenge(binary(), binary(), binary()) -> binary().
challenge(Key1, Key2, Key3) ->
IntKey1 = key_to_integer(Key1),
IntKey2 = key_to_integer(Key2),
erlang:md5(<< IntKey1:32, IntKey2:32, Key3/binary >>).
-spec key_to_integer(binary()) -> integer().
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 handler_init(#state{}, #http_req{}) -> ok.
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, Timeout} ->
websocket_handshake(State#state{timeout=Timeout},
Req2, HandlerState)
catch Class:Reason ->
upgrade_error(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, Req, erlang:get_stacktrace()])
end.
-spec upgrade_error(#http_req{}) -> ok.
upgrade_error(Req=#http_req{socket=Socket, transport=Transport}) ->
{ok, _Req} = cowboy_http_req:reply(400, [], [],
Req#http_req{resp_state=waiting}),
Transport:close(Socket).
-spec websocket_handshake(#state{}, #http_req{}, any()) -> ok.
websocket_handshake(State=#state{origin=Origin, challenge=Challenge},
Req=#http_req{transport=Transport, raw_host=Host, port=Port,
raw_path=Path}, HandlerState) ->
Location = websocket_location(Transport:name(), Host, Port, Path),
{ok, Req2} = cowboy_http_req:reply(
<<"101 WebSocket Protocol Handshake">>,
[{<<"Connection">>, <<"Upgrade">>},
{<<"Upgrade">>, <<"WebSocket">>},
{<<"Sec-WebSocket-Location">>, Location},
{<<"Sec-WebSocket-Origin">>, Origin}],
Challenge, Req#http_req{resp_state=waiting}),
handler_before_loop(State#state{messages=Transport:messages()},
Req2, HandlerState, <<>>).
-spec websocket_location(atom(), binary(), inet:ip_port(), binary())
-> binary().
websocket_location(Protocol, Host, Port, Path) ->
<< (websocket_location_protocol(Protocol))/binary, "://", Host/binary,
(websocket_location_port(ssl, Port))/binary, Path/binary >>.
-spec websocket_location_protocol(atom()) -> binary().
websocket_location_protocol(ssl) -> <<"wss">>;
websocket_location_protocol(_) -> <<"ws">>.
-spec websocket_location_port(atom(), inet:ip_port()) -> binary().
websocket_location_port(ssl, 443) -> <<"">>;
websocket_location_port(_, 80) -> <<"">>;
websocket_location_port(_, Port) -> <<":", (list_to_binary(integer_to_list(Port)))/binary>>.
-spec handler_before_loop(#state{}, #http_req{}, any(), binary()) -> ok.
handler_before_loop(State=#state{hibernate=true},
Req=#http_req{socket=Socket, transport=Transport},
HandlerState, SoFar) ->
Transport:setopts(Socket, [{active, once}]),
erlang:hibernate(?MODULE, handler_loop, [State#state{hibernate=false},
Req, HandlerState, SoFar]);
handler_before_loop(State, Req=#http_req{socket=Socket, transport=Transport},
HandlerState, SoFar) ->
Transport:setopts(Socket, [{active, once}]),
handler_loop(State, Req, HandlerState, SoFar).
%% @private
-spec handler_loop(#state{}, #http_req{}, any(), binary()) -> ok.
handler_loop(State=#state{messages={OK, Closed, Error}, timeout=Timeout},
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});
Message ->
handler_call(State, Req, HandlerState,
SoFar, Message, fun handler_before_loop/4)
after Timeout ->
websocket_close(State, Req, HandlerState, {normal, timeout})
end.
-spec websocket_data(#state{}, #http_req{}, any(), binary()) -> ok.
websocket_data(State, Req, HandlerState, << 255, 0, _Rest/bits >>) ->
websocket_close(State, Req, HandlerState, {normal, closed});
websocket_data(State, Req, HandlerState, <<>>) ->
handler_before_loop(State, Req, HandlerState, <<>>);
websocket_data(State, Req, HandlerState, Data) ->
websocket_frame(State, Req, HandlerState, Data, binary:first(Data)).
%% We do not support any frame type other than 0 yet. Just like the specs.
-spec websocket_frame(#state{}, #http_req{}, any(), binary(), byte()) -> ok.
websocket_frame(State=#state{eop=EOP}, Req, HandlerState, Data, 0) ->
case binary:match(Data, EOP) of
{Pos, 1} ->
Pos2 = Pos - 1,
<< 0, Frame:Pos2/binary, 255, Rest/bits >> = Data,
handler_call(State, Req, HandlerState,
Rest, {websocket, Frame}, fun websocket_data/4);
nomatch ->
%% @todo We probably should allow limiting frame length.
handler_before_loop(State, Req, HandlerState, Data)
end;
websocket_frame(State, Req, HandlerState, _Data, _FrameType) ->
websocket_close(State, Req, HandlerState, {error, badframe}).
-spec handler_call(#state{}, #http_req{}, any(), binary(), any(), fun()) -> ok.
handler_call(State=#state{handler=Handler, opts=Opts}, Req, HandlerState,
RemainingData, Message, NextState) ->
try Handler:websocket_handle(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, Data, Req2, HandlerState2} ->
websocket_send(Data, Req2),
NextState(State, Req2, HandlerState2, RemainingData);
{reply, Data, Req2, HandlerState2, hibernate} ->
websocket_send(Data, Req2),
NextState(State#state{hibernate=true},
Req2, HandlerState2, RemainingData);
{shutdown, Req2, HandlerState2} ->
websocket_close(State, Req2, HandlerState2, {normal, shutdown})
catch Class:Reason ->
error_logger:error_msg(
"** Handler ~p terminating in websocket_handle/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, Class, Reason, Message, Opts,
HandlerState, Req, erlang:get_stacktrace()]),
websocket_close(State, Req, HandlerState, {error, handler})
end.
-spec websocket_send(binary(), #http_req{}) -> ok.
websocket_send(Data, #http_req{socket=Socket, transport=Transport}) ->
Transport:send(Socket, << 0, Data/binary, 255 >>).
-spec websocket_close(#state{}, #http_req{}, any(), {atom(), atom()}) -> ok.
websocket_close(State, Req=#http_req{socket=Socket, transport=Transport},
HandlerState, Reason) ->
Transport:send(Socket, << 255, 0 >>),
Transport:close(Socket),
handler_terminate(State, Req, HandlerState, Reason).
-spec handler_terminate(#state{}, #http_req{},
any(), atom() | {atom(), atom()}) -> ok.
handler_terminate(#state{handler=Handler, opts=Opts},
Req, HandlerState, TerminateReason) ->
try
Handler:websocket_terminate(TerminateReason, Req, HandlerState)
catch Class:Reason ->
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, Req, erlang:get_stacktrace()])
end.
%% eunit
-ifdef(TEST).
websocket_location_test() ->
?assertEqual(<<"ws://localhost/path">>, websocket_location(other, <<"localhost">>, 80, <<"/path">>)),
?assertEqual(<<"ws://localhost:8080/path">>, websocket_location(other, <<"localhost">>, 8080, <<"/path">>)),
?assertEqual(<<"wss://localhost/path">>, websocket_location(ssl, <<"localhost">>, 443, <<"/path">>)),
?assertEqual(<<"wss://localhost:8443/path">>, websocket_location(ssl, <<"localhost">>, 8443, <<"/path">>)),
ok.
-endif.
|
