aboutsummaryrefslogtreecommitdiffstats
path: root/src/ranch.erl
blob: 752819e51a0b7acbbe922fb7ac778d4246b0ca2d (plain) (blame)
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
%% Copyright (c) 2011-2012, 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 Ranch API to start and stop listeners.
-module(ranch).

-export([start_listener/6]).
-export([stop_listener/1]).
-export([child_spec/6]).
-export([accept_ack/1]).
-export([get_port/1]).
-export([get_max_connections/1]).
-export([set_max_connections/2]).
-export([get_protocol_options/1]).
-export([set_protocol_options/2]).
-export([filter_options/3]).
-export([set_option_default/3]).
-export([require/1]).

-type max_conns() :: non_neg_integer() | infinity.
-export_type([max_conns/0]).

%% @doc Start a listener for the given transport and protocol.
%%
%% A listener is effectively a pool of <em>NbAcceptors</em> acceptors.
%% Acceptors accept connections on the given <em>Transport</em> and forward
%% connections to the given <em>Protocol</em> handler. Both transport and
%% protocol modules can be given options through the <em>TransOpts</em> and
%% the <em>ProtoOpts</em> arguments. Available options are documented in the
%% <em>listen</em> transport function and in the protocol module of your choice.
%%
%% All acceptor and connection processes are supervised by the listener.
%%
%% It is recommended to set a large enough number of acceptors to improve
%% performance. The exact number depends of course on your hardware, on the
%% protocol used and on the number of expected simultaneous connections.
%%
%% The <em>Transport</em> option <em>max_connections</em> allows you to define
%% the maximum number of simultaneous connections for this listener. It defaults
%% to 1024. See <em>ranch_listener</em> for more details on limiting the number
%% of connections.
%%
%% <em>Ref</em> can be used to stop the listener later on.
%%
%% This function will return `{error, badarg}` if and only if the transport
%% module given doesn't appear to be correct.
-spec start_listener(any(), non_neg_integer(), module(), any(), module(), any())
	-> {ok, pid()} | {error, badarg}.
start_listener(Ref, NbAcceptors, Transport, TransOpts, Protocol, ProtoOpts)
		when is_integer(NbAcceptors) andalso is_atom(Transport)
		andalso is_atom(Protocol) ->
	_ = code:ensure_loaded(Transport),
	case erlang:function_exported(Transport, name, 0) of
		false ->
			{error, badarg};
		true ->
			Res = supervisor:start_child(ranch_sup, child_spec(Ref, NbAcceptors,
					Transport, TransOpts, Protocol, ProtoOpts)),
			case proplists:get_value(socket, TransOpts) of
				undefined ->
					ok;
				Socket ->
					%% change the controlling process so the caller dying doesn't
					%% close the port
					ListenerPid = ranch_server:lookup_listener(Ref),
					%%% Note: the catch is here because SSL crashes when you change
					%%% the controlling process of a listen socket because of a bug.
					%%% The bug will be fixed in R16.
					catch(Transport:controlling_process(Socket, ListenerPid))
			end,
			Res
	end.

%% @doc Stop a listener identified by <em>Ref</em>.
%%
%% Note that stopping the listener will close all currently running
%% connections abruptly.
-spec stop_listener(any()) -> ok | {error, not_found}.
stop_listener(Ref) ->
	case supervisor:terminate_child(ranch_sup, {ranch_listener_sup, Ref}) of
		ok ->
			supervisor:delete_child(ranch_sup, {ranch_listener_sup, Ref});
		{error, Reason} ->
			{error, Reason}
	end.

%% @doc Return a child spec suitable for embedding.
%%
%% When you want to embed Ranch in another application, you can use this
%% function to create a <em>ChildSpec</em> suitable for use in a supervisor.
%% The parameters are the same as in <em>start_listener/6</em> but rather
%% than hooking the listener to the Ranch internal supervisor, it just returns
%% the spec.
-spec child_spec(any(), non_neg_integer(), module(), any(), module(), any())
	-> supervisor:child_spec().
child_spec(Ref, NbAcceptors, Transport, TransOpts, Protocol, ProtoOpts)
		when is_integer(NbAcceptors) andalso is_atom(Transport)
		andalso is_atom(Protocol) ->
	{{ranch_listener_sup, Ref}, {ranch_listener_sup, start_link, [
		Ref, NbAcceptors, Transport, TransOpts, Protocol, ProtoOpts
	]}, permanent, 5000, supervisor, [ranch_listener_sup]}.

%% @doc Acknowledge the accepted connection.
%%
%% Effectively used to make sure the socket control has been given to
%% the protocol process before starting to use it.
-spec accept_ack(pid()) -> ok.
accept_ack(ListenerPid) ->
	receive {shoot, ListenerPid} -> ok end.

%% @doc Return the listener's port.
-spec get_port(any()) -> inet:port_number().
get_port(Ref) ->
	ListenerPid = ranch_server:lookup_listener(Ref),
	{ok, Port} = ranch_listener:get_port(ListenerPid),
	Port.

%% @doc Return the max number of connections allowed concurrently.
-spec get_max_connections(any()) -> max_conns().
get_max_connections(Ref) ->
	ListenerPid = ranch_server:lookup_listener(Ref),
	{ok, MaxConnections} = ranch_listener:get_max_connections(ListenerPid),
	MaxConnections.

%% @doc Set the max number of connections allowed concurrently.
-spec set_max_connections(any(), max_conns()) -> ok.
set_max_connections(Ref, MaxConnections) ->
	ListenerPid = ranch_server:lookup_listener(Ref),
	ok = ranch_listener:set_max_connections(ListenerPid, MaxConnections).

%% @doc Return the current protocol options for the given listener.
-spec get_protocol_options(any()) -> any().
get_protocol_options(Ref) ->
	ListenerPid = ranch_server:lookup_listener(Ref),
	{ok, ProtoOpts} = ranch_listener:get_protocol_options(ListenerPid),
	ProtoOpts.

%% @doc Upgrade the protocol options for the given listener.
%%
%% The upgrade takes place at the acceptor level, meaning that only the
%% newly accepted connections receive the new protocol options. This has
%% no effect on the currently opened connections.
-spec set_protocol_options(any(), any()) -> ok.
set_protocol_options(Ref, ProtoOpts) ->
	ListenerPid = ranch_server:lookup_listener(Ref),
	ok = ranch_listener:set_protocol_options(ListenerPid, ProtoOpts).

%% @doc Filter a list of options and remove all unwanted values.
%%
%% It takes a list of options, a list of allowed keys and an accumulator.
%% This accumulator can be used to set default options that should never
%% be overriden.
-spec filter_options([{atom(), any()}], [atom()], Acc)
	-> Acc when Acc :: [any()].
filter_options([], _, Acc) ->
	Acc;
filter_options([Opt = {Key, _}|Tail], AllowedKeys, Acc) ->
	case lists:member(Key, AllowedKeys) of
		true -> filter_options(Tail, AllowedKeys, [Opt|Acc]);
		false -> filter_options(Tail, AllowedKeys, Acc)
	end.

%% @doc Add an option to a list, but only if it wasn't previously set.
-spec set_option_default(Opts, atom(), any())
	-> Opts when Opts :: [{atom(), any()}].
set_option_default(Opts, Key, Value) ->
	case lists:keymember(Key, 1, Opts) of
		true -> Opts;
		false -> [{Key, Value}|Opts]
	end.

%% @doc Start the given applications if they were not already started.
-spec require(list(module())) -> ok.
require([]) ->
	ok;
require([App|Tail]) ->
	case application:start(App) of
		ok -> ok;
		{error, {already_started, App}} -> ok
	end,
	require(Tail).