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
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
|
%% Copyright (c) 2011, Loïc Hoguin <[email protected]>
%% Copyright (c) 2011, Anthony Ramine <[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 HTTP protocol handler.
%%
%% The available options are:
%% <dl>
%% <dt>dispatch</dt><dd>The dispatch list for this protocol.</dd>
%% <dt>max_empty_lines</dt><dd>Max number of empty lines before a request.
%% Defaults to 5.</dd>
%% <dt>timeout</dt><dd>Time in milliseconds before an idle keep-alive
%% connection is closed. Defaults to 5000 milliseconds.</dd>
%% </dl>
%%
%% Note that there is no need to monitor these processes when using Cowboy as
%% an application as it already supervises them under the listener supervisor.
%%
%% @see cowboy_dispatcher
%% @see cowboy_http_handler
-module(cowboy_http_protocol).
-export([start_link/3]). %% API.
-export([init/3, parse_request/1]). %% FSM.
-include("include/http.hrl").
-record(state, {
socket :: inet:socket(),
transport :: module(),
dispatch :: cowboy_dispatcher:dispatch_rules(),
handler :: {module(), any()},
req_empty_lines = 0 :: integer(),
max_empty_lines :: integer(),
timeout :: timeout(),
connection = keepalive :: keepalive | close,
buffer = <<>> :: binary()
}).
%% API.
%% @doc Start an HTTP protocol process.
-spec start_link(inet:socket(), module(), any()) -> {ok, pid()}.
start_link(Socket, Transport, Opts) ->
Pid = spawn_link(?MODULE, init, [Socket, Transport, Opts]),
{ok, Pid}.
%% FSM.
%% @private
-spec init(inet:socket(), module(), any()) -> ok.
init(Socket, Transport, Opts) ->
Dispatch = proplists:get_value(dispatch, Opts, []),
MaxEmptyLines = proplists:get_value(max_empty_lines, Opts, 5),
Timeout = proplists:get_value(timeout, Opts, 5000),
wait_request(#state{socket=Socket, transport=Transport,
dispatch=Dispatch, max_empty_lines=MaxEmptyLines, timeout=Timeout}).
%% @private
-spec parse_request(#state{}) -> ok.
%% @todo Use decode_packet options to limit length?
parse_request(State=#state{buffer=Buffer}) ->
case erlang:decode_packet(http_bin, Buffer, []) of
{ok, Request, Rest} -> request(Request, State#state{buffer=Rest});
{more, _Length} -> wait_request(State);
{error, _Reason} -> error_response(400, State)
end.
-spec wait_request(#state{}) -> ok.
wait_request(State=#state{socket=Socket, transport=Transport,
timeout=T, buffer=Buffer}) ->
case Transport:recv(Socket, 0, T) of
{ok, Data} -> parse_request(State#state{
buffer= << Buffer/binary, Data/binary >>});
{error, timeout} -> error_terminate(408, State);
{error, closed} -> terminate(State)
end.
-spec request({http_request, http_method(), http_uri(),
http_version()}, #state{}) -> ok.
%% @todo We probably want to handle some things differently between versions.
request({http_request, _Method, _URI, Version}, State)
when Version =/= {1, 0}, Version =/= {1, 1} ->
error_terminate(505, State);
%% @todo We need to cleanup the URI properly.
request({http_request, Method, {abs_path, AbsPath}, Version},
State=#state{socket=Socket, transport=Transport}) ->
{Path, RawPath, Qs} = cowboy_dispatcher:split_path(AbsPath),
ConnAtom = version_to_connection(Version),
parse_header(#http_req{socket=Socket, transport=Transport,
connection=ConnAtom, method=Method, version=Version,
path=Path, raw_path=RawPath, raw_qs=Qs},
State#state{connection=ConnAtom});
request({http_request, Method, '*', Version},
State=#state{socket=Socket, transport=Transport}) ->
ConnAtom = version_to_connection(Version),
parse_header(#http_req{socket=Socket, transport=Transport,
connection=ConnAtom, method=Method, version=Version,
path='*', raw_path= <<"*">>, raw_qs= <<>>},
State#state{connection=ConnAtom});
request({http_request, _Method, _URI, _Version}, State) ->
error_terminate(501, State);
request({http_error, <<"\r\n">>},
State=#state{req_empty_lines=N, max_empty_lines=N}) ->
error_terminate(400, State);
request({http_error, <<"\r\n">>}, State=#state{req_empty_lines=N}) ->
parse_request(State#state{req_empty_lines=N + 1});
request({http_error, _Any}, State) ->
error_terminate(400, State).
-spec parse_header(#http_req{}, #state{}) -> ok.
parse_header(Req, State=#state{buffer=Buffer}) ->
case erlang:decode_packet(httph_bin, Buffer, []) of
{ok, Header, Rest} -> header(Header, Req, State#state{buffer=Rest});
{more, _Length} -> wait_header(Req, State);
{error, _Reason} -> error_response(400, State)
end.
-spec wait_header(#http_req{}, #state{}) -> ok.
wait_header(Req, State=#state{socket=Socket,
transport=Transport, timeout=T, buffer=Buffer}) ->
case Transport:recv(Socket, 0, T) of
{ok, Data} -> parse_header(Req, State#state{
buffer= << Buffer/binary, Data/binary >>});
{error, timeout} -> error_terminate(408, State);
{error, closed} -> terminate(State)
end.
-spec header({http_header, integer(), http_header(), any(), binary()}
| http_eoh, #http_req{}, #state{}) -> ok.
header({http_header, _I, 'Host', _R, RawHost}, Req=#http_req{
transport=Transport, host=undefined}, State) ->
RawHost2 = binary_to_lower(RawHost),
case catch cowboy_dispatcher:split_host(RawHost2) of
{Host, RawHost3, undefined} ->
Port = default_port(Transport:name()),
dispatch(Req#http_req{host=Host, raw_host=RawHost3, port=Port,
headers=[{'Host', RawHost3}|Req#http_req.headers]}, State);
{Host, RawHost3, Port} ->
dispatch(Req#http_req{host=Host, raw_host=RawHost3, port=Port,
headers=[{'Host', RawHost3}|Req#http_req.headers]}, State);
{'EXIT', _Reason} ->
error_terminate(400, State)
end;
%% Ignore Host headers if we already have it.
header({http_header, _I, 'Host', _R, _V}, Req, State) ->
parse_header(Req, State);
header({http_header, _I, 'Connection', _R, Connection}, Req, State) ->
ConnAtom = connection_to_atom(Connection),
parse_header(Req#http_req{connection=ConnAtom,
headers=[{'Connection', Connection}|Req#http_req.headers]},
State#state{connection=ConnAtom});
header({http_header, _I, Field, _R, Value}, Req, State) ->
parse_header(Req#http_req{headers=[{Field, Value}|Req#http_req.headers]},
State);
%% The Host header is required.
header(http_eoh, #http_req{host=undefined}, State) ->
error_terminate(400, State);
header(http_eoh, Req, State=#state{buffer=Buffer}) ->
handler_init(Req#http_req{buffer=Buffer}, State#state{buffer= <<>>});
header({http_error, _Bin}, _Req, State) ->
error_terminate(500, State).
-spec dispatch(#http_req{}, #state{}) -> ok.
dispatch(Req=#http_req{host=Host, path=Path},
State=#state{dispatch=Dispatch}) ->
%% @todo We probably want to filter the Host and Path here to allow
%% things like url rewriting.
case cowboy_dispatcher:match(Host, Path, Dispatch) of
{ok, Handler, Opts, Binds, HostInfo, PathInfo} ->
parse_header(Req#http_req{host_info=HostInfo, path_info=PathInfo,
bindings=Binds},
State#state{handler={Handler, Opts}});
{error, notfound, host} ->
error_terminate(400, State);
{error, notfound, path} ->
error_terminate(404, State)
end.
-spec handler_init(#http_req{}, #state{}) -> ok.
handler_init(Req, State=#state{
transport=Transport, handler={Handler, Opts}}) ->
try Handler:init({Transport:name(), http}, Req, Opts) of
{ok, Req2, HandlerState} ->
handler_loop(HandlerState, Req2, State);
%% @todo {upgrade, transport, Module}
{upgrade, protocol, Module} ->
Module:upgrade(Handler, Opts, Req)
catch Class:Reason ->
error_terminate(500, State),
error_logger:error_msg(
"** Handler ~p terminating in init/3 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 handler_loop(any(), #http_req{}, #state{}) -> ok.
handler_loop(HandlerState, Req, State=#state{handler={Handler, Opts}}) ->
try Handler:handle(Req#http_req{resp_state=waiting}, HandlerState) of
{ok, Req2, HandlerState2} ->
next_request(HandlerState2, Req2, State)
catch Class:Reason ->
error_logger:error_msg(
"** Handler ~p terminating in handle/2 for the reason ~p:~p~n"
"** Options were ~p~n** Handler state was ~p~n"
"** Request was ~p~n** Stacktrace: ~p~n~n",
[Handler, Class, Reason, Opts,
HandlerState, Req, erlang:get_stacktrace()]),
handler_terminate(HandlerState, Req, State),
terminate(State)
end.
-spec handler_terminate(any(), #http_req{}, #state{}) -> ok | error.
handler_terminate(HandlerState, Req, #state{handler={Handler, Opts}}) ->
try
Handler:terminate(Req#http_req{resp_state=locked}, HandlerState)
catch Class:Reason ->
error_logger:error_msg(
"** Handler ~p terminating in terminate/2 for the reason ~p:~p~n"
"** Options were ~p~n** Handler state was ~p~n"
"** Request was ~p~n** Stacktrace: ~p~n~n",
[Handler, Class, Reason, Opts,
HandlerState, Req, erlang:get_stacktrace()]),
error
end.
-spec next_request(any(), #http_req{}, #state{}) -> ok.
next_request(HandlerState, Req=#http_req{buffer=Buffer}, State) ->
HandlerRes = handler_terminate(HandlerState, Req, State),
BodyRes = ensure_body_processed(Req),
RespRes = ensure_response(Req, State),
case {HandlerRes, BodyRes, RespRes, State#state.connection} of
{ok, ok, ok, keepalive} ->
?MODULE:parse_request(State#state{buffer=Buffer});
_Closed ->
terminate(State)
end.
-spec ensure_body_processed(#http_req{}) -> ok | close.
ensure_body_processed(#http_req{body_state=done}) ->
ok;
ensure_body_processed(Req=#http_req{body_state=waiting}) ->
case cowboy_http_req:body(Req) of
{error, badarg} -> ok; %% No body.
{error, _Reason} -> close;
_Any -> ok
end.
-spec ensure_response(#http_req{}, #state{}) -> ok.
%% The handler has already fully replied to the client.
ensure_response(#http_req{resp_state=done}, _State) ->
ok;
%% No response has been sent but everything apparently went fine.
%% Reply with 204 No Content to indicate this.
ensure_response(#http_req{resp_state=waiting}, State) ->
error_response(204, State);
%% Close the chunked reply.
ensure_response(#http_req{socket=Socket, transport=Transport,
resp_state=chunks}, _State) ->
Transport:send(Socket, <<"0\r\n\r\n">>),
close.
-spec error_response(http_status(), #state{}) -> ok.
error_response(Code, #state{socket=Socket,
transport=Transport, connection=Connection}) ->
_ = cowboy_http_req:reply(Code, [], [], #http_req{
socket=Socket, transport=Transport,
connection=Connection, resp_state=waiting}),
ok.
-spec error_terminate(http_status(), #state{}) -> ok.
error_terminate(Code, State) ->
error_response(Code, State#state{connection=close}),
terminate(State).
-spec terminate(#state{}) -> ok.
terminate(#state{socket=Socket, transport=Transport}) ->
Transport:close(Socket),
ok.
%% Internal.
-spec version_to_connection(http_version()) -> keepalive | close.
version_to_connection({1, 1}) -> keepalive;
version_to_connection(_Any) -> close.
-spec connection_to_atom(binary()) -> keepalive | close.
connection_to_atom(<<"keep-alive">>) ->
keepalive;
connection_to_atom(<<"close">>) ->
close;
connection_to_atom(Connection) ->
case binary_to_lower(Connection) of
<<"close">> -> close;
_Any -> keepalive
end.
-spec default_port(atom()) -> 80 | 443.
default_port(ssl) -> 443;
default_port(_) -> 80.
%% We are excluding a few characters on purpose.
-spec binary_to_lower(binary()) -> binary().
binary_to_lower(L) ->
<< << (char_to_lower(C)) >> || << C >> <= L >>.
%% We gain noticeable speed by matching each value directly.
-spec char_to_lower(char()) -> char().
char_to_lower($A) -> $a;
char_to_lower($B) -> $b;
char_to_lower($C) -> $c;
char_to_lower($D) -> $d;
char_to_lower($E) -> $e;
char_to_lower($F) -> $f;
char_to_lower($G) -> $g;
char_to_lower($H) -> $h;
char_to_lower($I) -> $i;
char_to_lower($J) -> $j;
char_to_lower($K) -> $k;
char_to_lower($L) -> $l;
char_to_lower($M) -> $m;
char_to_lower($N) -> $n;
char_to_lower($O) -> $o;
char_to_lower($P) -> $p;
char_to_lower($Q) -> $q;
char_to_lower($R) -> $r;
char_to_lower($S) -> $s;
char_to_lower($T) -> $t;
char_to_lower($U) -> $u;
char_to_lower($V) -> $v;
char_to_lower($W) -> $w;
char_to_lower($X) -> $x;
char_to_lower($Y) -> $y;
char_to_lower($Z) -> $z;
char_to_lower(Ch) -> Ch.
|
