%%%----------------------------------------------------------------------
%%% File : mod_ping.erl
%%% Author : Brian Cully <bjc@kublai.com>
%%% Purpose : Support XEP-0199 XMPP Ping and periodic keepalives
%%% Created : 11 Jul 2009 by Brian Cully <bjc@kublai.com>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2009 ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License
%%% along with this program; if not, write to the Free Software
%%% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
%%% 02111-1307 USA
%%%
%%%----------------------------------------------------------------------
-module(mod_ping).
-author('bjc@kublai.com').
-behavior(gen_mod).
-behavior(gen_server).
-include("ejabberd.hrl").
-include("jlib.hrl").
-define(SUPERVISOR, ejabberd_sup).
-define(NS_PING, "urn:xmpp:ping").
-define(DEFAULT_SEND_PINGS, false). % bool()
-define(DEFAULT_PING_INTERVAL, 60). % seconds
-define(DICT, dict).
%% API
-export([start_link/2, start_ping/2, stop_ping/2]).
%% gen_mod callbacks
-export([start/2, stop/1]).
%% gen_server callbacks
-export([init/1, terminate/2, handle_call/3, handle_cast/2,
handle_info/2, code_change/3]).
%% Hook callbacks
-export([iq_ping/3, user_online/3, user_offline/3, user_send/3]).
-record(state, {host = "",
send_pings = ?DEFAULT_SEND_PINGS,
ping_interval = ?DEFAULT_PING_INTERVAL,
timeout_action = none,
timers = ?DICT:new()}).
%%====================================================================
%% API
%%====================================================================
start_link(Host, Opts) ->
Proc = gen_mod:get_module_proc(Host, ?MODULE),
gen_server:start_link({local, Proc}, ?MODULE, [Host, Opts], []).
start_ping(Host, JID) ->
Proc = gen_mod:get_module_proc(Host, ?MODULE),
gen_server:cast(Proc, {start_ping, JID}).
stop_ping(Host, JID) ->
Proc = gen_mod:get_module_proc(Host, ?MODULE),
gen_server:cast(Proc, {stop_ping, JID}).
%%====================================================================
%% gen_mod callbacks
%%====================================================================
start(Host, Opts) ->
Proc = gen_mod:get_module_proc(Host, ?MODULE),
PingSpec = {Proc, {?MODULE, start_link, [Host, Opts]},
transient, 2000, worker, [?MODULE]},
supervisor:start_child(?SUPERVISOR, PingSpec).
stop(Host) ->
Proc = gen_mod:get_module_proc(Host, ?MODULE),
gen_server:call(Proc, stop),
supervisor:delete_child(?SUPERVISOR, Proc).
%%====================================================================
%% gen_server callbacks
%%====================================================================
init([Host, Opts]) ->
SendPings = gen_mod:get_opt(send_pings, Opts, ?DEFAULT_SEND_PINGS),
PingInterval = gen_mod:get_opt(ping_interval, Opts, ?DEFAULT_PING_INTERVAL),
TimeoutAction = gen_mod:get_opt(timeout_action, Opts, none),
IQDisc = gen_mod:get_opt(iqdisc, Opts, one_queue),
mod_disco:register_feature(Host, ?NS_PING),
gen_iq_handler:add_iq_handler(ejabberd_sm, Host, ?NS_PING,
?MODULE, iq_ping, IQDisc),
gen_iq_handler:add_iq_handler(ejabberd_local, Host, ?NS_PING,
?MODULE, iq_ping, IQDisc),
case SendPings of
true ->
ejabberd_hooks:add(sm_register_connection_hook, Host,
?MODULE, user_online, 100),
ejabberd_hooks:add(sm_remove_connection_hook, Host,
?MODULE, user_offline, 100),
ejabberd_hooks:add(user_send_packet, Host,
?MODULE, user_send, 100);
_ ->
ok
end,
{ok, #state{host = Host,
send_pings = SendPings,
ping_interval = PingInterval,
timeout_action = TimeoutAction,
timers = ?DICT:new()}}.
terminate(_Reason, #state{host = Host}) ->
ejabberd_hooks:delete(sm_remove_connection_hook, Host,
?MODULE, user_offline, 100),
ejabberd_hooks:delete(sm_register_connection_hook, Host,
?MODULE, user_online, 100),
ejabberd_hooks:delete(user_send_packet, Host,
?MODULE, user_send, 100),
gen_iq_handler:remove_iq_handler(ejabberd_local, Host, ?NS_PING),
gen_iq_handler:remove_iq_handler(ejabberd_sm, Host, ?NS_PING),
mod_disco:unregister_feature(Host, ?NS_PING).
handle_call(stop, _From, State) ->
{stop, normal, ok, State};
handle_call(_Req, _From, State) ->
{reply, {error, badarg}, State}.
handle_cast({start_ping, JID}, State) ->
Timers = add_timer(JID, State#state.ping_interval, State#state.timers),
{noreply, State#state{timers = Timers}};
handle_cast({stop_ping, JID}, State) ->
Timers = del_timer(JID, State#state.timers),
{noreply, State#state{timers = Timers}};
handle_cast({iq_pong, JID, timeout}, State) ->
Timers = del_timer(JID, State#state.timers),
ejabberd_hooks:run(user_ping_timeout, State#state.host, [JID]),
case State#state.timeout_action of
kill ->
#jid{user = User, server = Server, resource = Resource} = JID,
case ejabberd_sm:get_session_pid(User, Server, Resource) of
Pid when is_pid(Pid) ->
ejabberd_c2s:stop(Pid);
_ ->
ok
end;
_ ->
ok
end,
{noreply, State#state{timers = Timers}};
handle_cast(_Msg, State) ->
{noreply, State}.
handle_info({timeout, _TRef, {ping, JID}}, State) ->
IQ = #iq{type = get,
sub_el = [{xmlelement, "ping", [{"xmlns", ?NS_PING}], []}]},
Pid = self(),
F = fun(Response) ->
gen_server:cast(Pid, {iq_pong, JID, Response})
end,
From = jlib:make_jid("", State#state.host, ""),
ejabberd_local:route_iq(From, JID, IQ, F),
Timers = add_timer(JID, State#state.ping_interval, State#state.timers),
{noreply, State#state{timers = Timers}};
handle_info(_Info, State) ->
{noreply, State}.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%====================================================================
%% Hook callbacks
%%====================================================================
iq_ping(_From, _To, #iq{type = Type, sub_el = SubEl} = IQ) ->
case {Type, SubEl} of
{get, {xmlelement, "ping", _, _}} ->
IQ#iq{type = result, sub_el = []};
_ ->
IQ#iq{type = error, sub_el = [SubEl, ?ERR_FEATURE_NOT_IMPLEMENTED]}
end.
user_online(_SID, JID, _Info) ->
start_ping(JID#jid.lserver, JID).
user_offline(_SID, JID, _Info) ->
stop_ping(JID#jid.lserver, JID).
user_send(JID, _From, _Packet) ->
start_ping(JID#jid.lserver, JID).
%%====================================================================
%% Internal functions
%%====================================================================
add_timer(JID, Interval, Timers) ->
LJID = jlib:jid_tolower(JID),
NewTimers = case ?DICT:find(LJID, Timers) of
{ok, OldTRef} ->
cancel_timer(OldTRef),
?DICT:erase(LJID, Timers);
_ ->
Timers
end,
TRef = erlang:start_timer(Interval * 1000, self(), {ping, JID}),
?DICT:store(LJID, TRef, NewTimers).
del_timer(JID, Timers) ->
LJID = jlib:jid_tolower(JID),
case ?DICT:find(LJID, Timers) of
{ok, TRef} ->
cancel_timer(TRef),
?DICT:erase(LJID, Timers);
_ ->
Timers
end.
cancel_timer(TRef) ->
case erlang:cancel_timer(TRef) of
false ->
receive
{timeout, TRef, _} ->
ok
after 0 ->
ok
end;
_ ->
ok
end.
