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
|
%% 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 Dispatch requests according to a hostname and path.
-module(cowboy_dispatcher).
-export([split_host/1, split_path/1, match/3]). %% API.
-type bindings() :: list({atom(), binary()}).
-type path_tokens() :: list(binary()).
-type match_rule() :: '_' | '*' | list(binary() | '_' | '...' | atom()).
-type dispatch_path() :: list({match_rule(), module(), any()}).
-type dispatch_rule() :: {Host::match_rule(), Path::dispatch_path()}.
-type dispatch_rules() :: list(dispatch_rule()).
-export_type([bindings/0, path_tokens/0, dispatch_rules/0]).
-include_lib("eunit/include/eunit.hrl").
%% API.
%% @doc Split a hostname into a list of tokens.
-spec split_host(binary())
-> {path_tokens(), binary(), undefined | inet:ip_port()}.
split_host(<<>>) ->
{[], <<>>, undefined};
split_host(Host) ->
case binary:split(Host, <<":">>) of
[Host] ->
{binary:split(Host, <<".">>, [global, trim]), Host, undefined};
[Host2, Port] ->
{binary:split(Host2, <<".">>, [global, trim]), Host2,
list_to_integer(binary_to_list(Port))}
end.
%% @doc Split a path into a list of path segments.
%%
%% Following RFC2396, this function may return path segments containing any
%% character, including <em>/</em> if, and only if, a <em>/</em> was escaped
%% and part of a path segment.
-spec split_path(binary()) -> {path_tokens(), binary(), binary()}.
split_path(Path) ->
case binary:split(Path, <<"?">>) of
[Path] -> {do_split_path(Path, <<"/">>), Path, <<>>};
[<<>>, Qs] -> {[], <<>>, Qs};
[Path2, Qs] -> {do_split_path(Path2, <<"/">>), Path2, Qs}
end.
-spec do_split_path(binary(), <<_:8>>) -> path_tokens().
do_split_path(RawPath, Separator) ->
EncodedPath = case binary:split(RawPath, Separator, [global, trim]) of
[<<>>|Path] -> Path;
Path -> Path
end,
[quoted:from_url(Token) || Token <- EncodedPath].
%% @doc Match hostname tokens and path tokens against dispatch rules.
%%
%% It is typically used for matching tokens for the hostname and path of
%% the request against a global dispatch rule for your listener.
%%
%% Dispatch rules are a list of <em>{Hostname, PathRules}</em> tuples, with
%% <em>PathRules</em> being a list of <em>{Path, HandlerMod, HandlerOpts}</em>.
%%
%% <em>Hostname</em> and <em>Path</em> are match rules and can be either the
%% atom <em>'_'</em>, which matches everything for a single token, the atom
%% <em>'*'</em>, which matches everything for the rest of the tokens, or a
%% list of tokens. Each token can be either a binary, the atom <em>'_'</em>,
%% the atom '...' or a named atom. A binary token must match exactly,
%% <em>'_'</em> matches everything for a single token, <em>'...'</em> matches
%% everything for the rest of the tokens and a named atom will bind the
%% corresponding token value and return it.
%%
%% The list of hostname tokens is reversed before matching. For example, if
%% we were to match "www.dev-extend.eu", we would first match "eu", then
%% "dev-extend", then "www". This means that in the context of hostnames,
%% the <em>'...'</em> atom matches properly the lower levels of the domain
%% as would be expected.
%%
%% When a result is found, this function will return the handler module and
%% options found in the dispatch list, a key-value list of bindings and
%% the tokens that were matched by the <em>'...'</em> atom for both the
%% hostname and path.
-spec match(Host::path_tokens(), Path::path_tokens(), dispatch_rules())
-> {ok, module(), any(), bindings(),
HostInfo::undefined | path_tokens(),
PathInfo::undefined | path_tokens()}
| {error, notfound, host} | {error, notfound, path}.
match(_Host, _Path, []) ->
{error, notfound, host};
match(_Host, Path, [{'_', PathMatchs}|_Tail]) ->
match_path(Path, PathMatchs, [], undefined);
match(Host, Path, [{HostMatch, PathMatchs}|Tail]) ->
case try_match(host, Host, HostMatch) of
false ->
match(Host, Path, Tail);
{true, HostBinds, undefined} ->
match_path(Path, PathMatchs, HostBinds, undefined);
{true, HostBinds, HostInfo} ->
match_path(Path, PathMatchs, HostBinds, lists:reverse(HostInfo))
end.
-spec match_path(path_tokens(), dispatch_path(), bindings(),
HostInfo::undefined | path_tokens())
-> {ok, module(), any(), bindings(),
HostInfo::undefined | path_tokens(),
PathInfo::undefined | path_tokens()}
| {error, notfound, path}.
match_path(_Path, [], _HostBinds, _HostInfo) ->
{error, notfound, path};
match_path(_Path, [{'_', Handler, Opts}|_Tail], HostBinds, HostInfo) ->
{ok, Handler, Opts, HostBinds, HostInfo, undefined};
match_path('*', [{'*', Handler, Opts}|_Tail], HostBinds, HostInfo) ->
{ok, Handler, Opts, HostBinds, HostInfo, undefined};
match_path(Path, [{PathMatch, Handler, Opts}|Tail], HostBinds, HostInfo) ->
case try_match(path, Path, PathMatch) of
false ->
match_path(Path, Tail, HostBinds, HostInfo);
{true, PathBinds, PathInfo} ->
{ok, Handler, Opts, HostBinds ++ PathBinds, HostInfo, PathInfo}
end.
%% Internal.
-spec try_match(host | path, path_tokens(), match_rule())
-> {true, bindings(), undefined | path_tokens()} | false.
try_match(host, List, Match) ->
list_match(lists:reverse(List), lists:reverse(Match), []);
try_match(path, List, Match) ->
list_match(List, Match, []).
-spec list_match(path_tokens(), match_rule(), bindings())
-> {true, bindings(), undefined | path_tokens()} | false.
%% Atom '...' matches any trailing path, stop right now.
list_match(List, ['...'], Binds) ->
{true, Binds, List};
%% Atom '_' matches anything, continue.
list_match([_E|Tail], ['_'|TailMatch], Binds) ->
list_match(Tail, TailMatch, Binds);
%% Both values match, continue.
list_match([E|Tail], [E|TailMatch], Binds) ->
list_match(Tail, TailMatch, Binds);
%% Bind E to the variable name V and continue.
list_match([E|Tail], [V|TailMatch], Binds) when is_atom(V) ->
list_match(Tail, TailMatch, [{V, E}|Binds]);
%% Match complete.
list_match([], [], Binds) ->
{true, Binds, undefined};
%% Values don't match, stop.
list_match(_List, _Match, _Binds) ->
false.
%% Tests.
-ifdef(TEST).
split_host_test_() ->
%% {Host, Result}
Tests = [
{<<"">>, {[], <<"">>, undefined}},
{<<".........">>, {[], <<".........">>, undefined}},
{<<"*">>, {[<<"*">>], <<"*">>, undefined}},
{<<"cowboy.dev-extend.eu">>,
{[<<"cowboy">>, <<"dev-extend">>, <<"eu">>],
<<"cowboy.dev-extend.eu">>, undefined}},
{<<"dev-extend..eu">>,
{[<<"dev-extend">>, <<>>, <<"eu">>],
<<"dev-extend..eu">>, undefined}},
{<<"dev-extend.eu">>,
{[<<"dev-extend">>, <<"eu">>], <<"dev-extend.eu">>, undefined}},
{<<"dev-extend.eu:8080">>,
{[<<"dev-extend">>, <<"eu">>], <<"dev-extend.eu">>, 8080}},
{<<"a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z">>,
{[<<"a">>, <<"b">>, <<"c">>, <<"d">>, <<"e">>, <<"f">>, <<"g">>,
<<"h">>, <<"i">>, <<"j">>, <<"k">>, <<"l">>, <<"m">>, <<"n">>,
<<"o">>, <<"p">>, <<"q">>, <<"r">>, <<"s">>, <<"t">>, <<"u">>,
<<"v">>, <<"w">>, <<"x">>, <<"y">>, <<"z">>],
<<"a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z">>,
undefined}}
],
[{H, fun() -> R = split_host(H) end} || {H, R} <- Tests].
split_host_fail_test_() ->
Tests = [
<<"dev-extend.eu:owns">>,
<<"dev-extend.eu: owns">>,
<<"dev-extend.eu:42fun">>,
<<"dev-extend.eu: 42fun">>,
<<"dev-extend.eu:42 fun">>,
<<"dev-extend.eu:fun 42">>,
<<"dev-extend.eu: 42">>,
<<":owns">>,
<<":42 fun">>
],
[{H, fun() -> case catch split_host(H) of
{'EXIT', _Reason} -> ok
end end} || H <- Tests].
split_path_test_() ->
%% {Path, Result, QueryString}
Tests = [
{<<"?">>, [], <<"">>, <<"">>},
{<<"???">>, [], <<"">>, <<"??">>},
{<<"/">>, [], <<"/">>, <<"">>},
{<<"/users">>, [<<"users">>], <<"/users">>, <<"">>},
{<<"/users?">>, [<<"users">>], <<"/users">>, <<"">>},
{<<"/users?a">>, [<<"users">>], <<"/users">>, <<"a">>},
{<<"/users/42/friends?a=b&c=d&e=notsure?whatever">>,
[<<"users">>, <<"42">>, <<"friends">>],
<<"/users/42/friends">>, <<"a=b&c=d&e=notsure?whatever">>},
{<<"/users/a+b/c%21d?e+f=g+h">>,
[<<"users">>, <<"a b">>, <<"c!d">>],
<<"/users/a+b/c%21d">>, <<"e+f=g+h">>}
],
[{P, fun() -> {R, RawP, Qs} = split_path(P) end}
|| {P, R, RawP, Qs} <- Tests].
match_test_() ->
Dispatch = [
{[<<"www">>, '_', <<"dev-extend">>, <<"eu">>], [
{[<<"users">>, '_', <<"mails">>], match_any_subdomain_users, []}
]},
{[<<"dev-extend">>, <<"eu">>], [
{[<<"users">>, id, <<"friends">>], match_extend_users_friends, []},
{'_', match_extend, []}
]},
{[<<"dev-extend">>, var], [
{[<<"threads">>, var], match_duplicate_vars,
[we, {expect, two}, var, here]}
]},
{[<<"erlang">>, ext], [
{'_', match_erlang_ext, []}
]},
{'_', [
{[<<"users">>, id, <<"friends">>], match_users_friends, []},
{'_', match_any, []}
]}
],
%% {Host, Path, Result}
Tests = [
{[<<"any">>], [], {ok, match_any, [], []}},
{[<<"www">>, <<"any">>, <<"dev-extend">>, <<"eu">>],
[<<"users">>, <<"42">>, <<"mails">>],
{ok, match_any_subdomain_users, [], []}},
{[<<"www">>, <<"dev-extend">>, <<"eu">>],
[<<"users">>, <<"42">>, <<"mails">>], {ok, match_any, [], []}},
{[<<"www">>, <<"dev-extend">>, <<"eu">>], [], {ok, match_any, [], []}},
{[<<"www">>, <<"any">>, <<"dev-extend">>, <<"eu">>],
[<<"not_users">>, <<"42">>, <<"mails">>], {error, notfound, path}},
{[<<"dev-extend">>, <<"eu">>], [], {ok, match_extend, [], []}},
{[<<"dev-extend">>, <<"eu">>], [<<"users">>, <<"42">>, <<"friends">>],
{ok, match_extend_users_friends, [], [{id, <<"42">>}]}},
{[<<"erlang">>, <<"fr">>], '_',
{ok, match_erlang_ext, [], [{ext, <<"fr">>}]}},
{[<<"any">>], [<<"users">>, <<"444">>, <<"friends">>],
{ok, match_users_friends, [], [{id, <<"444">>}]}},
{[<<"dev-extend">>, <<"fr">>], [<<"threads">>, <<"987">>],
{ok, match_duplicate_vars, [we, {expect, two}, var, here],
[{var, <<"fr">>}, {var, <<"987">>}]}}
],
[{lists:flatten(io_lib:format("~p, ~p", [H, P])), fun() ->
{ok, Handler, Opts, Binds, undefined, undefined} = match(H, P, Dispatch)
end} || {H, P, {ok, Handler, Opts, Binds}} <- Tests].
match_info_test_() ->
Dispatch = [
{[<<"www">>, <<"dev-extend">>, <<"eu">>], [
{[<<"pathinfo">>, <<"is">>, <<"next">>, '...'], match_path, []}
]},
{['...', <<"dev-extend">>, <<"eu">>], [
{'_', match_any, []}
]}
],
Tests = [
{[<<"dev-extend">>, <<"eu">>], [],
{ok, match_any, [], [], [], undefined}},
{[<<"bugs">>, <<"dev-extend">>, <<"eu">>], [],
{ok, match_any, [], [], [<<"bugs">>], undefined}},
{[<<"cowboy">>, <<"bugs">>, <<"dev-extend">>, <<"eu">>], [],
{ok, match_any, [], [], [<<"cowboy">>, <<"bugs">>], undefined}},
{[<<"www">>, <<"dev-extend">>, <<"eu">>],
[<<"pathinfo">>, <<"is">>, <<"next">>],
{ok, match_path, [], [], undefined, []}},
{[<<"www">>, <<"dev-extend">>, <<"eu">>],
[<<"pathinfo">>, <<"is">>, <<"next">>, <<"path_info">>],
{ok, match_path, [], [], undefined, [<<"path_info">>]}},
{[<<"www">>, <<"dev-extend">>, <<"eu">>],
[<<"pathinfo">>, <<"is">>, <<"next">>, <<"foo">>, <<"bar">>],
{ok, match_path, [], [], undefined, [<<"foo">>, <<"bar">>]}}
],
[{lists:flatten(io_lib:format("~p, ~p", [H, P])), fun() ->
R = match(H, P, Dispatch)
end} || {H, P, R} <- Tests].
-endif.
|
