%%%---------------------------------------------------------------------- %%% File : mod_push_keepalive.erl %%% Author : Holger Weiss %%% Purpose : Keep pending XEP-0198 sessions alive with XEP-0357 %%% Created : 15 Jul 2017 by Holger Weiss %%% %%% %%% ejabberd, Copyright (C) 2017-2020 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., %%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. %%% %%%---------------------------------------------------------------------- -module(mod_push_keepalive). -author('holger@zedat.fu-berlin.de'). -behaviour(gen_mod). %% gen_mod callbacks. -export([start/2, stop/1, reload/3, mod_opt_type/1, mod_options/1, depends/2]). -export([mod_doc/0]). %% ejabberd_hooks callbacks. -export([c2s_session_pending/1, c2s_session_resumed/1, c2s_copy_session/2, c2s_handle_cast/2, c2s_handle_info/2, c2s_stanza/3]). -include("logger.hrl"). -include("xmpp.hrl"). -include("translate.hrl"). -define(PUSH_BEFORE_TIMEOUT_PERIOD, 120000). % 2 minutes. -type c2s_state() :: ejabberd_c2s:state(). %%-------------------------------------------------------------------- %% gen_mod callbacks. %%-------------------------------------------------------------------- -spec start(binary(), gen_mod:opts()) -> ok. start(Host, Opts) -> case mod_push_keepalive_opt:wake_on_start(Opts) of true -> wake_all(Host); false -> ok end, register_hooks(Host). -spec stop(binary()) -> ok. stop(Host) -> unregister_hooks(Host). -spec reload(binary(), gen_mod:opts(), gen_mod:opts()) -> ok. reload(Host, NewOpts, OldOpts) -> case {mod_push_keepalive_opt:wake_on_start(NewOpts), mod_push_keepalive_opt:wake_on_start(OldOpts)} of {true, false} -> wake_all(Host); _ -> ok end. -spec depends(binary(), gen_mod:opts()) -> [{module(), hard | soft}]. depends(_Host, _Opts) -> [{mod_push, hard}, {mod_client_state, soft}, {mod_stream_mgmt, soft}]. -spec mod_opt_type(atom()) -> econf:validator(). mod_opt_type(resume_timeout) -> econf:either( econf:int(0, 0), econf:timeout(second)); mod_opt_type(wake_on_start) -> econf:bool(); mod_opt_type(wake_on_timeout) -> econf:bool(). mod_options(_Host) -> [{resume_timeout, timer:seconds(259200)}, {wake_on_start, false}, {wake_on_timeout, true}]. mod_doc() -> #{desc => [?T("This module tries to keep the stream management " "session (see 'mod_stream_mgmt') of a disconnected " "mobile client alive if the client enabled push " "notifications for that session. However, the normal " "session resumption timeout is restored once a push " "notification is issued, so the session will be closed " "if the client doesn't respond to push notifications."), "", ?T("The module depends on 'mod_push'.")], opts => [{resume_timeout, #{value => "timeout()", desc => ?T("This option specifies the period of time until " "the session of a disconnected push client times out. " "This timeout is only in effect as long as no push " "notification is issued. Once that happened, the " "resumption timeout configured for the 'mod_stream_mgmt' " "module is restored. " "The default value is '72' minutes.")}}, {wake_on_start, #{value => "true | false", desc => ?T("If this option is set to 'true', notifications " "are generated for **all** registered push clients " "during server startup. This option should not be " "enabled on servers with many push clients as it " "can generate significant load on the involved push " "services and the server itself. " "The default value is 'false'.")}}, {wake_on_timeout, #{value => "true | false", desc => ?T("If this option is set to 'true', a notification " "is generated shortly before the session would time " "out as per the 'resume_timeout' option. " "The default value is 'true'.")}}]}. %%-------------------------------------------------------------------- %% Register/unregister hooks. %%-------------------------------------------------------------------- -spec register_hooks(binary()) -> ok. register_hooks(Host) -> ejabberd_hooks:add(c2s_session_pending, Host, ?MODULE, c2s_session_pending, 50), ejabberd_hooks:add(c2s_session_resumed, Host, ?MODULE, c2s_session_resumed, 50), ejabberd_hooks:add(c2s_copy_session, Host, ?MODULE, c2s_copy_session, 50), ejabberd_hooks:add(c2s_handle_cast, Host, ?MODULE, c2s_handle_cast, 40), ejabberd_hooks:add(c2s_handle_info, Host, ?MODULE, c2s_handle_info, 50), ejabberd_hooks:add(c2s_handle_send, Host, ?MODULE, c2s_stanza, 50). -spec unregister_hooks(binary()) -> ok. unregister_hooks(Host) -> ejabberd_hooks:delete(c2s_session_pending, Host, ?MODULE, c2s_session_pending, 50), ejabberd_hooks:delete(c2s_session_resumed, Host, ?MODULE, c2s_session_resumed, 50), ejabberd_hooks:delete(c2s_copy_session, Host, ?MODULE, c2s_copy_session, 50), ejabberd_hooks:delete(c2s_handle_cast, Host, ?MODULE, c2s_handle_cast, 40), ejabberd_hooks:delete(c2s_handle_info, Host, ?MODULE, c2s_handle_info, 50), ejabberd_hooks:delete(c2s_handle_send, Host, ?MODULE, c2s_stanza, 50). %%-------------------------------------------------------------------- %% Hook callbacks. %%-------------------------------------------------------------------- -spec c2s_stanza(c2s_state(), xmpp_element() | xmlel(), term()) -> c2s_state(). c2s_stanza(#{push_enabled := true, mgmt_state := pending} = State, Pkt, _SendResult) -> case mod_push:is_incoming_chat_msg(Pkt) of true -> maybe_restore_resume_timeout(State); false -> State end; c2s_stanza(State, _Pkt, _SendResult) -> State. -spec c2s_session_pending(c2s_state()) -> c2s_state(). c2s_session_pending(#{push_enabled := true, mgmt_queue := Queue} = State) -> case mod_stream_mgmt:queue_find(fun mod_push:is_incoming_chat_msg/1, Queue) of none -> State1 = maybe_adjust_resume_timeout(State), maybe_start_wakeup_timer(State1); _Msg -> State end; c2s_session_pending(State) -> State. -spec c2s_session_resumed(c2s_state()) -> c2s_state(). c2s_session_resumed(#{push_enabled := true} = State) -> maybe_restore_resume_timeout(State); c2s_session_resumed(State) -> State. -spec c2s_copy_session(c2s_state(), c2s_state()) -> c2s_state(). c2s_copy_session(State, #{push_enabled := true, push_resume_timeout := ResumeTimeout, push_wake_on_timeout := WakeOnTimeout} = OldState) -> State1 = case maps:find(push_resume_timeout_orig, OldState) of {ok, Val} -> State#{push_resume_timeout_orig => Val}; error -> State end, State1#{push_resume_timeout => ResumeTimeout, push_wake_on_timeout => WakeOnTimeout}; c2s_copy_session(State, _) -> State. -spec c2s_handle_cast(c2s_state(), any()) -> c2s_state(). c2s_handle_cast(#{lserver := LServer} = State, push_enable) -> ResumeTimeout = mod_push_keepalive_opt:resume_timeout(LServer), WakeOnTimeout = mod_push_keepalive_opt:wake_on_timeout(LServer), State#{push_resume_timeout => ResumeTimeout, push_wake_on_timeout => WakeOnTimeout}; c2s_handle_cast(State, push_disable) -> State1 = maps:remove(push_resume_timeout, State), maps:remove(push_wake_on_timeout, State1); c2s_handle_cast(State, _Msg) -> State. -spec c2s_handle_info(c2s_state(), any()) -> c2s_state() | {stop, c2s_state()}. c2s_handle_info(#{push_enabled := true, mgmt_state := pending, jid := JID} = State, {timeout, _, push_keepalive}) -> ?INFO_MSG("Waking ~ts before session times out", [jid:encode(JID)]), mod_push:notify(State, none, undefined), {stop, State}; c2s_handle_info(State, _) -> State. %%-------------------------------------------------------------------- %% Internal functions. %%-------------------------------------------------------------------- -spec maybe_adjust_resume_timeout(c2s_state()) -> c2s_state(). maybe_adjust_resume_timeout(#{push_resume_timeout := undefined} = State) -> State; maybe_adjust_resume_timeout(#{push_resume_timeout := Timeout} = State) -> OrigTimeout = mod_stream_mgmt:get_resume_timeout(State), ?DEBUG("Adjusting resume timeout to ~B seconds", [Timeout div 1000]), State1 = mod_stream_mgmt:set_resume_timeout(State, Timeout), State1#{push_resume_timeout_orig => OrigTimeout}. -spec maybe_restore_resume_timeout(c2s_state()) -> c2s_state(). maybe_restore_resume_timeout(#{push_resume_timeout_orig := Timeout} = State) -> ?DEBUG("Restoring resume timeout to ~B seconds", [Timeout div 1000]), State1 = mod_stream_mgmt:set_resume_timeout(State, Timeout), maps:remove(push_resume_timeout_orig, State1); maybe_restore_resume_timeout(State) -> State. -spec maybe_start_wakeup_timer(c2s_state()) -> c2s_state(). maybe_start_wakeup_timer(#{push_wake_on_timeout := true, push_resume_timeout := ResumeTimeout} = State) when is_integer(ResumeTimeout), ResumeTimeout > ?PUSH_BEFORE_TIMEOUT_PERIOD -> WakeTimeout = ResumeTimeout - ?PUSH_BEFORE_TIMEOUT_PERIOD, ?DEBUG("Scheduling wake-up timer to fire in ~B seconds", [WakeTimeout div 1000]), erlang:start_timer(WakeTimeout, self(), push_keepalive), State; maybe_start_wakeup_timer(State) -> State. -spec wake_all(binary()) -> ok. wake_all(LServer) -> ?INFO_MSG("Waking all push clients on ~ts", [LServer]), Mod = gen_mod:db_mod(LServer, mod_push), case Mod:lookup_sessions(LServer) of {ok, Sessions} -> IgnoreResponse = fun(_) -> ok end, lists:foreach(fun({_, PushLJID, Node, XData}) -> mod_push:notify(LServer, PushLJID, Node, XData, none, undefined, IgnoreResponse) end, Sessions); error -> ok end.