%%%---------------------------------------------------------------------- %%% File : ejabberd_sm.erl %%% Author : Alexey Shchepin %%% Purpose : Session manager %%% Created : 24 Nov 2002 by Alexey Shchepin %%% %%% %%% ejabberd, Copyright (C) 2002-2015 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(ejabberd_sm). -author('alexey@process-one.net'). -behaviour(gen_server). %% API -export([start/0, start_link/0, route/3, open_session/5, open_session/6, close_session/4, check_in_subscription/6, bounce_offline_message/3, disconnect_removed_user/2, get_user_resources/2, get_user_present_resources/2, set_presence/7, unset_presence/6, close_session_unset_presence/5, dirty_get_sessions_list/0, dirty_get_my_sessions_list/0, get_vh_session_list/1, get_vh_session_number/1, register_iq_handler/4, register_iq_handler/5, unregister_iq_handler/2, force_update_presence/1, connected_users/0, connected_users_number/0, user_resources/2, kick_user/2, get_session_pid/3, get_user_info/3, get_user_ip/3, get_max_user_sessions/2, get_all_pids/0, is_existing_resource/3 ]). %% gen_server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). -include("ejabberd.hrl"). -include("logger.hrl"). -include("jlib.hrl"). -include("ejabberd_commands.hrl"). -include("mod_privacy.hrl"). -include("ejabberd_sm.hrl"). -callback init() -> ok | {error, any()}. -callback set_session(#session{}) -> ok. -callback delete_session(binary(), binary(), binary(), sid()) -> {ok, #session{}} | {error, notfound}. -callback get_sessions() -> [#session{}]. -callback get_sessions(binary()) -> [#session{}]. -callback get_sessions(binary(), binary()) -> [#session{}]. -callback get_sessions(binary(), binary(), binary()) -> [#session{}]. -record(state, {}). %% default value for the maximum number of user connections -define(MAX_USER_SESSIONS, infinity). %%==================================================================== %% API %%==================================================================== %%-------------------------------------------------------------------- %% Function: start_link() -> {ok,Pid} | ignore | {error,Error} %% Description: Starts the server %%-------------------------------------------------------------------- -export_type([sid/0]). start() -> ChildSpec = {?MODULE, {?MODULE, start_link, []}, transient, 1000, worker, [?MODULE]}, supervisor:start_child(ejabberd_sup, ChildSpec). start_link() -> gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). -spec route(jid(), jid(), xmlel() | broadcast()) -> ok. route(From, To, Packet) -> case catch do_route(From, To, Packet) of {'EXIT', Reason} -> ?ERROR_MSG("~p~nwhen processing: ~p", [Reason, {From, To, Packet}]); _ -> ok end. -spec open_session(sid(), binary(), binary(), binary(), prio(), info()) -> ok. open_session(SID, User, Server, Resource, Priority, Info) -> set_session(SID, User, Server, Resource, Priority, Info), check_for_sessions_to_replace(User, Server, Resource), JID = jlib:make_jid(User, Server, Resource), ejabberd_hooks:run(sm_register_connection_hook, JID#jid.lserver, [SID, JID, Info]). -spec open_session(sid(), binary(), binary(), binary(), info()) -> ok. open_session(SID, User, Server, Resource, Info) -> open_session(SID, User, Server, Resource, undefined, Info). -spec close_session(sid(), binary(), binary(), binary()) -> ok. close_session(SID, User, Server, Resource) -> Mod = get_sm_backend(), LUser = jlib:nodeprep(User), LServer = jlib:nameprep(Server), LResource = jlib:resourceprep(Resource), Info = case Mod:delete_session(LUser, LServer, LResource, SID) of {ok, #session{info = I}} -> I; {error, notfound} -> [] end, JID = jlib:make_jid(User, Server, Resource), ejabberd_hooks:run(sm_remove_connection_hook, JID#jid.lserver, [SID, JID, Info]). check_in_subscription(Acc, User, Server, _JID, _Type, _Reason) -> case ejabberd_auth:is_user_exists(User, Server) of true -> Acc; false -> {stop, false} end. -spec bounce_offline_message(jid(), jid(), xmlel()) -> stop. bounce_offline_message(From, To, Packet) -> Err = jlib:make_error_reply(Packet, ?ERR_SERVICE_UNAVAILABLE), ejabberd_router:route(To, From, Err), stop. -spec disconnect_removed_user(binary(), binary()) -> ok. disconnect_removed_user(User, Server) -> ejabberd_sm:route(jlib:make_jid(<<"">>, <<"">>, <<"">>), jlib:make_jid(User, Server, <<"">>), {broadcast, {exit, <<"User removed">>}}). get_user_resources(User, Server) -> LUser = jlib:nodeprep(User), LServer = jlib:nameprep(Server), Mod = get_sm_backend(), Ss = Mod:get_sessions(LUser, LServer), [element(3, S#session.usr) || S <- clean_session_list(Ss)]. -spec get_user_present_resources(binary(), binary()) -> [tuple()]. get_user_present_resources(LUser, LServer) -> Mod = get_sm_backend(), Ss = Mod:get_sessions(LUser, LServer), [{S#session.priority, element(3, S#session.usr)} || S <- clean_session_list(Ss), is_integer(S#session.priority)]. -spec get_user_ip(binary(), binary(), binary()) -> ip(). get_user_ip(User, Server, Resource) -> LUser = jlib:nodeprep(User), LServer = jlib:nameprep(Server), LResource = jlib:resourceprep(Resource), Mod = get_sm_backend(), case Mod:get_sessions(LUser, LServer, LResource) of [] -> undefined; Ss -> Session = lists:max(Ss), proplists:get_value(ip, Session#session.info) end. -spec get_user_info(binary(), binary(), binary()) -> info() | offline. get_user_info(User, Server, Resource) -> LUser = jlib:nodeprep(User), LServer = jlib:nameprep(Server), LResource = jlib:resourceprep(Resource), Mod = get_sm_backend(), case Mod:get_sessions(LUser, LServer, LResource) of [] -> offline; Ss -> Session = lists:max(Ss), Node = node(element(2, Session#session.sid)), Conn = proplists:get_value(conn, Session#session.info), IP = proplists:get_value(ip, Session#session.info), [{node, Node}, {conn, Conn}, {ip, IP}] end. -spec set_presence(sid(), binary(), binary(), binary(), prio(), xmlel(), info()) -> ok. set_presence(SID, User, Server, Resource, Priority, Presence, Info) -> set_session(SID, User, Server, Resource, Priority, Info), ejabberd_hooks:run(set_presence_hook, jlib:nameprep(Server), [User, Server, Resource, Presence]). -spec unset_presence(sid(), binary(), binary(), binary(), binary(), info()) -> ok. unset_presence(SID, User, Server, Resource, Status, Info) -> set_session(SID, User, Server, Resource, undefined, Info), ejabberd_hooks:run(unset_presence_hook, jlib:nameprep(Server), [User, Server, Resource, Status]). -spec close_session_unset_presence(sid(), binary(), binary(), binary(), binary()) -> ok. close_session_unset_presence(SID, User, Server, Resource, Status) -> close_session(SID, User, Server, Resource), ejabberd_hooks:run(unset_presence_hook, jlib:nameprep(Server), [User, Server, Resource, Status]). -spec get_session_pid(binary(), binary(), binary()) -> none | pid(). get_session_pid(User, Server, Resource) -> LUser = jlib:nodeprep(User), LServer = jlib:nameprep(Server), LResource = jlib:resourceprep(Resource), Mod = get_sm_backend(), case Mod:get_sessions(LUser, LServer, LResource) of [#session{sid = {_, Pid}}] -> Pid; _ -> none end. -spec dirty_get_sessions_list() -> [ljid()]. dirty_get_sessions_list() -> Mod = get_sm_backend(), [S#session.usr || S <- Mod:get_sessions()]. dirty_get_my_sessions_list() -> Mod = get_sm_backend(), [S || S <- Mod:get_sessions(), node(element(2, S#session.sid)) == node()]. -spec get_vh_session_list(binary()) -> [ljid()]. get_vh_session_list(Server) -> LServer = jlib:nameprep(Server), Mod = get_sm_backend(), [S#session.usr || S <- Mod:get_sessions(LServer)]. -spec get_all_pids() -> [pid()]. get_all_pids() -> Mod = get_sm_backend(), [element(2, S#session.sid) || S <- Mod:get_sessions()]. get_vh_session_number(Server) -> LServer = jlib:nameprep(Server), Mod = get_sm_backend(), length(Mod:get_sessions(LServer)). register_iq_handler(Host, XMLNS, Module, Fun) -> ejabberd_sm ! {register_iq_handler, Host, XMLNS, Module, Fun}. -spec register_iq_handler(binary(), binary(), atom(), atom(), list()) -> any(). register_iq_handler(Host, XMLNS, Module, Fun, Opts) -> ejabberd_sm ! {register_iq_handler, Host, XMLNS, Module, Fun, Opts}. -spec unregister_iq_handler(binary(), binary()) -> any(). unregister_iq_handler(Host, XMLNS) -> ejabberd_sm ! {unregister_iq_handler, Host, XMLNS}. %%==================================================================== %% gen_server callbacks %%==================================================================== %%-------------------------------------------------------------------- %% Function: init(Args) -> {ok, State} | %% {ok, State, Timeout} | %% ignore | %% {stop, Reason} %% Description: Initiates the server %%-------------------------------------------------------------------- init([]) -> Mod = get_sm_backend(), Mod:init(), ets:new(sm_iqtable, [named_table]), lists:foreach( fun(Host) -> ejabberd_hooks:add(roster_in_subscription, Host, ejabberd_sm, check_in_subscription, 20), ejabberd_hooks:add(offline_message_hook, Host, ejabberd_sm, bounce_offline_message, 100), ejabberd_hooks:add(remove_user, Host, ejabberd_sm, disconnect_removed_user, 100) end, ?MYHOSTS), ejabberd_commands:register_commands(commands()), {ok, #state{}}. %%-------------------------------------------------------------------- %% Function: %% handle_call(Request, From, State) -> {reply, Reply, State} | %% {reply, Reply, State, Timeout} | %% {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, Reply, State} | %% {stop, Reason, State} %% Description: Handling call messages %%-------------------------------------------------------------------- handle_call(_Request, _From, State) -> Reply = ok, {reply, Reply, State}. %%-------------------------------------------------------------------- %% Function: handle_cast(Msg, State) -> {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, State} %% Description: Handling cast messages %%-------------------------------------------------------------------- handle_cast(_Msg, State) -> {noreply, State}. %%-------------------------------------------------------------------- %% Function: handle_info(Info, State) -> {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, State} %% Description: Handling all non call/cast messages %%-------------------------------------------------------------------- handle_info({route, From, To, Packet}, State) -> case catch do_route(From, To, Packet) of {'EXIT', Reason} -> ?ERROR_MSG("~p~nwhen processing: ~p", [Reason, {From, To, Packet}]); _ -> ok end, {noreply, State}; handle_info({register_iq_handler, Host, XMLNS, Module, Function}, State) -> ets:insert(sm_iqtable, {{XMLNS, Host}, Module, Function}), {noreply, State}; handle_info({register_iq_handler, Host, XMLNS, Module, Function, Opts}, State) -> ets:insert(sm_iqtable, {{XMLNS, Host}, Module, Function, Opts}), {noreply, State}; handle_info({unregister_iq_handler, Host, XMLNS}, State) -> case ets:lookup(sm_iqtable, {XMLNS, Host}) of [{_, Module, Function, Opts}] -> gen_iq_handler:stop_iq_handler(Module, Function, Opts); _ -> ok end, ets:delete(sm_iqtable, {XMLNS, Host}), {noreply, State}; handle_info(_Info, State) -> {noreply, State}. %%-------------------------------------------------------------------- %% Function: terminate(Reason, State) -> void() %% Description: This function is called by a gen_server when it is about to %% terminate. It should be the opposite of Module:init/1 and do any necessary %% cleaning up. When it returns, the gen_server terminates with Reason. %% The return value is ignored. %%-------------------------------------------------------------------- terminate(_Reason, _State) -> ejabberd_commands:unregister_commands(commands()), ok. %%-------------------------------------------------------------------- %% Func: code_change(OldVsn, State, Extra) -> {ok, NewState} %% Description: Convert process state when code is changed %%-------------------------------------------------------------------- code_change(_OldVsn, State, _Extra) -> {ok, State}. %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- set_session(SID, User, Server, Resource, Priority, Info) -> LUser = jlib:nodeprep(User), LServer = jlib:nameprep(Server), LResource = jlib:resourceprep(Resource), US = {LUser, LServer}, USR = {LUser, LServer, LResource}, Mod = get_sm_backend(), Mod:set_session(#session{sid = SID, usr = USR, us = US, priority = Priority, info = Info}). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% do_route(From, To, {broadcast, _} = Packet) -> case To#jid.lresource of <<"">> -> lists:foreach(fun(R) -> do_route(From, jlib:jid_replace_resource(To, R), Packet) end, get_user_resources(To#jid.user, To#jid.server)); _ -> {U, S, R} = jlib:jid_tolower(To), Mod = get_sm_backend(), case Mod:get_sessions(U, S, R) of [] -> ?DEBUG("packet dropped~n", []); Ss -> Session = lists:max(Ss), Pid = element(2, Session#session.sid), ?DEBUG("sending to process ~p~n", [Pid]), Pid ! {route, From, To, Packet} end end; do_route(From, To, #xmlel{} = Packet) -> ?DEBUG("session manager~n\tfrom ~p~n\tto ~p~n\tpacket " "~P~n", [From, To, Packet, 8]), #jid{user = User, server = Server, luser = LUser, lserver = LServer, lresource = LResource} = To, #xmlel{name = Name, attrs = Attrs} = Packet, case LResource of <<"">> -> case Name of <<"presence">> -> {Pass, _Subsc} = case xml:get_attr_s(<<"type">>, Attrs) of <<"subscribe">> -> Reason = xml:get_path_s(Packet, [{elem, <<"status">>}, cdata]), {is_privacy_allow(From, To, Packet) andalso ejabberd_hooks:run_fold(roster_in_subscription, LServer, false, [User, Server, From, subscribe, Reason]), true}; <<"subscribed">> -> {is_privacy_allow(From, To, Packet) andalso ejabberd_hooks:run_fold(roster_in_subscription, LServer, false, [User, Server, From, subscribed, <<"">>]), true}; <<"unsubscribe">> -> {is_privacy_allow(From, To, Packet) andalso ejabberd_hooks:run_fold(roster_in_subscription, LServer, false, [User, Server, From, unsubscribe, <<"">>]), true}; <<"unsubscribed">> -> {is_privacy_allow(From, To, Packet) andalso ejabberd_hooks:run_fold(roster_in_subscription, LServer, false, [User, Server, From, unsubscribed, <<"">>]), true}; _ -> {true, false} end, if Pass -> PResources = get_user_present_resources(LUser, LServer), lists:foreach(fun ({_, R}) -> do_route(From, jlib:jid_replace_resource(To, R), Packet) end, PResources); true -> ok end; <<"message">> -> route_message(From, To, Packet); <<"iq">> -> process_iq(From, To, Packet); _ -> ok end; _ -> Mod = get_sm_backend(), case Mod:get_sessions(LUser, LServer, LResource) of [] -> case Name of <<"message">> -> route_message(From, To, Packet); <<"iq">> -> case xml:get_attr_s(<<"type">>, Attrs) of <<"error">> -> ok; <<"result">> -> ok; _ -> Err = jlib:make_error_reply(Packet, ?ERR_SERVICE_UNAVAILABLE), ejabberd_router:route(To, From, Err) end; _ -> ?DEBUG("packet dropped~n", []) end; Ss -> Session = lists:max(Ss), Pid = element(2, Session#session.sid), ?DEBUG("sending to process ~p~n", [Pid]), Pid ! {route, From, To, Packet} end end. %% The default list applies to the user as a whole, %% and is processed if there is no active list set %% for the target session/resource to which a stanza is addressed, %% or if there are no current sessions for the user. is_privacy_allow(From, To, Packet) -> User = To#jid.user, Server = To#jid.server, PrivacyList = ejabberd_hooks:run_fold(privacy_get_user_list, Server, #userlist{}, [User, Server]), is_privacy_allow(From, To, Packet, PrivacyList). %% Check if privacy rules allow this delivery %% Function copied from ejabberd_c2s.erl is_privacy_allow(From, To, Packet, PrivacyList) -> User = To#jid.user, Server = To#jid.server, allow == ejabberd_hooks:run_fold(privacy_check_packet, Server, allow, [User, Server, PrivacyList, {From, To, Packet}, in]). route_message(From, To, Packet) -> LUser = To#jid.luser, LServer = To#jid.lserver, PrioRes = get_user_present_resources(LUser, LServer), case catch lists:max(PrioRes) of {Priority, _R} when is_integer(Priority), Priority >= 0 -> lists:foreach(fun ({P, R}) when P == Priority -> LResource = jlib:resourceprep(R), Mod = get_sm_backend(), case Mod:get_sessions(LUser, LServer, LResource) of [] -> ok; % Race condition Ss -> Session = lists:max(Ss), Pid = element(2, Session#session.sid), ?DEBUG("sending to process ~p~n", [Pid]), Pid ! {route, From, To, Packet} end; %% Ignore other priority: ({_Prio, _Res}) -> ok end, PrioRes); _ -> case xml:get_tag_attr_s(<<"type">>, Packet) of <<"error">> -> ok; <<"groupchat">> -> bounce_offline_message(From, To, Packet); <<"headline">> -> bounce_offline_message(From, To, Packet); _ -> case ejabberd_auth:is_user_exists(LUser, LServer) of true -> case is_privacy_allow(From, To, Packet) of true -> ejabberd_hooks:run(offline_message_hook, LServer, [From, To, Packet]); false -> ok end; _ -> Err = jlib:make_error_reply(Packet, ?ERR_SERVICE_UNAVAILABLE), ejabberd_router:route(To, From, Err) end end end. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% clean_session_list(Ss) -> clean_session_list(lists:keysort(#session.usr, Ss), []). clean_session_list([], Res) -> Res; clean_session_list([S], Res) -> [S | Res]; clean_session_list([S1, S2 | Rest], Res) -> if S1#session.usr == S2#session.usr -> if S1#session.sid > S2#session.sid -> clean_session_list([S1 | Rest], Res); true -> clean_session_list([S2 | Rest], Res) end; true -> clean_session_list([S2 | Rest], [S1 | Res]) end. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% On new session, check if some existing connections need to be replace check_for_sessions_to_replace(User, Server, Resource) -> LUser = jlib:nodeprep(User), LServer = jlib:nameprep(Server), LResource = jlib:resourceprep(Resource), check_existing_resources(LUser, LServer, LResource), check_max_sessions(LUser, LServer). check_existing_resources(LUser, LServer, LResource) -> SIDs = get_resource_sessions(LUser, LServer, LResource), if SIDs == [] -> ok; true -> MaxSID = lists:max(SIDs), lists:foreach(fun ({_, Pid} = S) when S /= MaxSID -> Pid ! replaced; (_) -> ok end, SIDs) end. -spec is_existing_resource(binary(), binary(), binary()) -> boolean(). is_existing_resource(LUser, LServer, LResource) -> [] /= get_resource_sessions(LUser, LServer, LResource). get_resource_sessions(User, Server, Resource) -> LUser = jlib:nodeprep(User), LServer = jlib:nameprep(Server), LResource = jlib:resourceprep(Resource), Mod = get_sm_backend(), [S#session.sid || S <- Mod:get_sessions(LUser, LServer, LResource)]. check_max_sessions(LUser, LServer) -> Mod = get_sm_backend(), SIDs = [S#session.sid || S <- Mod:get_sessions(LUser, LServer)], MaxSessions = get_max_user_sessions(LUser, LServer), if length(SIDs) =< MaxSessions -> ok; true -> {_, Pid} = lists:min(SIDs), Pid ! replaced end. %% Get the user_max_session setting %% This option defines the max number of time a given users are allowed to %% log in %% Defaults to infinity get_max_user_sessions(LUser, Host) -> case acl:match_rule(Host, max_user_sessions, jlib:make_jid(LUser, Host, <<"">>)) of Max when is_integer(Max) -> Max; infinity -> infinity; _ -> ?MAX_USER_SESSIONS end. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% process_iq(From, To, Packet) -> IQ = jlib:iq_query_info(Packet), case IQ of #iq{xmlns = XMLNS} -> Host = To#jid.lserver, case ets:lookup(sm_iqtable, {XMLNS, Host}) of [{_, Module, Function}] -> ResIQ = Module:Function(From, To, IQ), if ResIQ /= ignore -> ejabberd_router:route(To, From, jlib:iq_to_xml(ResIQ)); true -> ok end; [{_, Module, Function, Opts}] -> gen_iq_handler:handle(Host, Module, Function, Opts, From, To, IQ); [] -> Err = jlib:make_error_reply(Packet, ?ERR_SERVICE_UNAVAILABLE), ejabberd_router:route(To, From, Err) end; reply -> ok; _ -> Err = jlib:make_error_reply(Packet, ?ERR_BAD_REQUEST), ejabberd_router:route(To, From, Err), ok end. -spec force_update_presence({binary(), binary()}) -> any(). force_update_presence({LUser, LServer}) -> Mod = get_sm_backend(), Ss = Mod:get_sessions(LUser, LServer), lists:foreach(fun (#session{sid = {_, Pid}}) -> Pid ! {force_update_presence, LUser} end, Ss). -spec get_sm_backend() -> module(). get_sm_backend() -> DBType = ejabberd_config:get_option(sm_db_type, fun(mnesia) -> mnesia; (internal) -> mnesia; (odbc) -> odbc; (redis) -> redis end, mnesia), list_to_atom("ejabberd_sm_" ++ atom_to_list(DBType)). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%% ejabberd commands commands() -> [#ejabberd_commands{name = connected_users, tags = [session], desc = "List all established sessions", module = ?MODULE, function = connected_users, args = [], result = {connected_users, {list, {sessions, string}}}}, #ejabberd_commands{name = connected_users_number, tags = [session, stats], desc = "Get the number of established sessions", module = ?MODULE, function = connected_users_number, args = [], result = {num_sessions, integer}}, #ejabberd_commands{name = user_resources, tags = [session], desc = "List user's connected resources", module = ?MODULE, function = user_resources, args = [{user, binary}, {host, binary}], result = {resources, {list, {resource, string}}}}, #ejabberd_commands{name = kick_user, tags = [session], desc = "Disconnect user's active sessions", module = ?MODULE, function = kick_user, args = [{user, binary}, {host, binary}], result = {num_resources, integer}}]. -spec connected_users() -> [binary()]. connected_users() -> USRs = dirty_get_sessions_list(), SUSRs = lists:sort(USRs), lists:map(fun ({U, S, R}) -> <> end, SUSRs). connected_users_number() -> length(dirty_get_sessions_list()). user_resources(User, Server) -> Resources = get_user_resources(User, Server), lists:sort(Resources). kick_user(User, Server) -> Resources = get_user_resources(User, Server), lists:foreach( fun(Resource) -> PID = get_session_pid(User, Server, Resource), PID ! kick end, Resources), length(Resources).