%%%----------------------------------------------------------------------
%%% File : ejabberd_s2s.erl
%%% Author : Alexey Shchepin <alexey@process-one.net>
%%% Purpose : S2S connections manager
%%% Created : 7 Dec 2002 by Alexey Shchepin <alexey@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2013 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(ejabberd_s2s).
-author('alexey@process-one.net').
-behaviour(gen_server).
%% API
-export([start_link/0, route/3, have_connection/1,
has_key/2, get_connections_pids/1, try_register/1,
remove_connection/3, find_connection/2,
dirty_get_connections/0, allow_host/2,
incoming_s2s_number/0, outgoing_s2s_number/0,
clean_temporarily_blocked_table/0,
list_temporarily_blocked_hosts/0,
external_host_overloaded/1, is_temporarly_blocked/1]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2,
handle_info/2, terminate/2, code_change/3]).
%% ejabberd API
-export([get_info_s2s_connections/1]).
-include("ejabberd.hrl").
-include("logger.hrl").
-include("jlib.hrl").
-include("ejabberd_commands.hrl").
-define(DEFAULT_MAX_S2S_CONNECTIONS_NUMBER, 1).
-define(DEFAULT_MAX_S2S_CONNECTIONS_NUMBER_PER_NODE, 1).
-define(S2S_OVERLOAD_BLOCK_PERIOD, 60).
%% once a server is temporarly blocked, it stay blocked for 60 seconds
-record(s2s, {fromto = {<<"">>, <<"">>} :: {binary(), binary()},
pid = self() :: pid() | '_',
key = <<"">> :: binary() | '_'}).
-record(state, {}).
-record(temporarily_blocked, {host = <<"">> :: binary(),
timestamp = now() :: erlang:timestamp()}).
-type temporarily_blocked() :: #temporarily_blocked{}.
%%====================================================================
%% API
%%====================================================================
%%--------------------------------------------------------------------
%% Function: start_link() -> {ok,Pid} | ignore | {error,Error}
%% Description: Starts the server
%%--------------------------------------------------------------------
start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [],
[]).
-spec route(jid(), jid(), xmlel()) -> 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.
clean_temporarily_blocked_table() ->
mnesia:clear_table(temporarily_blocked).
-spec list_temporarily_blocked_hosts() -> [temporarily_blocked()].
list_temporarily_blocked_hosts() ->
ets:tab2list(temporarily_blocked).
-spec external_host_overloaded(binary()) -> {aborted, any()} | {atomic, ok}.
external_host_overloaded(Host) ->
?INFO_MSG("Disabling connections from ~s for ~p "
"seconds",
[Host, ?S2S_OVERLOAD_BLOCK_PERIOD]),
mnesia:transaction(fun () ->
mnesia:write(#temporarily_blocked{host = Host,
timestamp =
now()})
end).
-spec is_temporarly_blocked(binary()) -> boolean().
is_temporarly_blocked(Host) ->
case mnesia:dirty_read(temporarily_blocked, Host) of
[] -> false;
[#temporarily_blocked{timestamp = T} = Entry] ->
case timer:now_diff(now(), T) of
N when N > (?S2S_OVERLOAD_BLOCK_PERIOD) * 1000 * 1000 ->
mnesia:dirty_delete_object(Entry), false;
_ -> true
end
end.
-spec remove_connection({binary(), binary()},
pid(), binary()) -> {atomic, ok} |
ok |
{aborted, any()}.
remove_connection(FromTo, Pid, Key) ->
case catch mnesia:dirty_match_object(s2s,
#s2s{fromto = FromTo, pid = Pid,
_ = '_'})
of
[#s2s{pid = Pid, key = Key}] ->
F = fun () ->
mnesia:delete_object(#s2s{fromto = FromTo, pid = Pid,
key = Key})
end,
mnesia:transaction(F);
_ -> ok
end.
-spec have_connection({binary(), binary()}) -> boolean().
have_connection(FromTo) ->
case catch mnesia:dirty_read(s2s, FromTo) of
[_] ->
true;
_ ->
false
end.
-spec has_key({binary(), binary()}, binary()) -> boolean().
has_key(FromTo, Key) ->
case mnesia:dirty_select(s2s,
[{#s2s{fromto = FromTo, key = Key, _ = '_'},
[],
['$_']}]) of
[] ->
false;
_ ->
true
end.
-spec get_connections_pids({binary(), binary()}) -> [pid()].
get_connections_pids(FromTo) ->
case catch mnesia:dirty_read(s2s, FromTo) of
L when is_list(L) ->
[Connection#s2s.pid || Connection <- L];
_ ->
[]
end.
-spec try_register({binary(), binary()}) -> {key, binary()} | false.
try_register(FromTo) ->
Key = randoms:get_string(),
MaxS2SConnectionsNumber = max_s2s_connections_number(FromTo),
MaxS2SConnectionsNumberPerNode =
max_s2s_connections_number_per_node(FromTo),
F = fun () ->
L = mnesia:read({s2s, FromTo}),
NeededConnections = needed_connections_number(L,
MaxS2SConnectionsNumber,
MaxS2SConnectionsNumberPerNode),
if NeededConnections > 0 ->
mnesia:write(#s2s{fromto = FromTo, pid = self(),
key = Key}),
{key, Key};
true -> false
end
end,
case mnesia:transaction(F) of
{atomic, Res} -> Res;
_ -> false
end.
-spec dirty_get_connections() -> [{binary(), binary()}].
dirty_get_connections() ->
mnesia:dirty_all_keys(s2s).
%%====================================================================
%% gen_server callbacks
%%====================================================================
%%--------------------------------------------------------------------
%% Function: init(Args) -> {ok, State} |
%% {ok, State, Timeout} |
%% ignore |
%% {stop, Reason}
%% Description: Initiates the server
%%--------------------------------------------------------------------
init([]) ->
update_tables(),
mnesia:create_table(s2s, [{ram_copies, [node()]}, {type, bag},
{attributes, record_info(fields, s2s)}]),
mnesia:add_table_copy(s2s, node(), ram_copies),
mnesia:subscribe(system),
ejabberd_commands:register_commands(commands()),
mnesia:create_table(temporarily_blocked, [{ram_copies, [node()]}, {attributes, record_info(fields, temporarily_blocked)}]),
{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({mnesia_system_event, {mnesia_down, Node}}, State) ->
clean_table_from_bad_node(Node),
{noreply, State};
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(_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
%%--------------------------------------------------------------------
clean_table_from_bad_node(Node) ->
F = fun() ->
Es = mnesia:select(
s2s,
[{#s2s{pid = '$1', _ = '_'},
[{'==', {node, '$1'}, Node}],
['$_']}]),
lists:foreach(fun(E) ->
mnesia:delete_object(E)
end, Es)
end,
mnesia:async_dirty(F).
do_route(From, To, Packet) ->
?DEBUG("s2s manager~n\tfrom ~p~n\tto ~p~n\tpacket "
"~P~n",
[From, To, Packet, 8]),
case find_connection(From, To) of
{atomic, Pid} when is_pid(Pid) ->
?DEBUG("sending to process ~p~n", [Pid]),
#xmlel{name = Name, attrs = Attrs, children = Els} =
Packet,
NewAttrs =
jlib:replace_from_to_attrs(jlib:jid_to_string(From),
jlib:jid_to_string(To), Attrs),
#jid{lserver = MyServer} = From,
ejabberd_hooks:run(s2s_send_packet, MyServer,
[From, To, Packet]),
send_element(Pid,
#xmlel{name = Name, attrs = NewAttrs, children = Els}),
ok;
{aborted, _Reason} ->
case xml:get_tag_attr_s(<<"type">>, Packet) of
<<"error">> -> ok;
<<"result">> -> ok;
_ ->
Err = jlib:make_error_reply(Packet,
?ERR_SERVICE_UNAVAILABLE),
ejabberd_router:route(To, From, Err)
end,
false
end.
-spec find_connection(jid(), jid()) -> {aborted, any()} | {atomic, pid()}.
find_connection(From, To) ->
#jid{lserver = MyServer} = From,
#jid{lserver = Server} = To,
FromTo = {MyServer, Server},
MaxS2SConnectionsNumber =
max_s2s_connections_number(FromTo),
MaxS2SConnectionsNumberPerNode =
max_s2s_connections_number_per_node(FromTo),
?DEBUG("Finding connection for ~p~n", [FromTo]),
case catch mnesia:dirty_read(s2s, FromTo) of
{'EXIT', Reason} -> {aborted, Reason};
[] ->
%% We try to establish all the connections if the host is not a
%% service and if the s2s host is not blacklisted or
%% is in whitelist:
case not is_service(From, To) andalso
allow_host(MyServer, Server)
of
true ->
NeededConnections = needed_connections_number([],
MaxS2SConnectionsNumber,
MaxS2SConnectionsNumberPerNode),
open_several_connections(NeededConnections, MyServer,
Server, From, FromTo,
MaxS2SConnectionsNumber,
MaxS2SConnectionsNumberPerNode);
false -> {aborted, error}
end;
L when is_list(L) ->
NeededConnections = needed_connections_number(L,
MaxS2SConnectionsNumber,
MaxS2SConnectionsNumberPerNode),
if NeededConnections > 0 ->
%% We establish the missing connections for this pair.
open_several_connections(NeededConnections, MyServer,
Server, From, FromTo,
MaxS2SConnectionsNumber,
MaxS2SConnectionsNumberPerNode);
true ->
%% We choose a connexion from the pool of opened ones.
{atomic, choose_connection(From, L)}
end
end.
choose_connection(From, Connections) ->
choose_pid(From, [C#s2s.pid || C <- Connections]).
choose_pid(From, Pids) ->
Pids1 = case [P || P <- Pids, node(P) == node()] of
[] -> Pids;
Ps -> Ps
end,
Pid =
lists:nth(erlang:phash(jlib:jid_remove_resource(From),
length(Pids1)),
Pids1),
?DEBUG("Using ejabberd_s2s_out ~p~n", [Pid]),
Pid.
open_several_connections(N, MyServer, Server, From,
FromTo, MaxS2SConnectionsNumber,
MaxS2SConnectionsNumberPerNode) ->
ConnectionsResult = [new_connection(MyServer, Server,
From, FromTo, MaxS2SConnectionsNumber,
MaxS2SConnectionsNumberPerNode)
|| _N <- lists:seq(1, N)],
case [PID || {atomic, PID} <- ConnectionsResult] of
[] -> hd(ConnectionsResult);
PIDs -> {atomic, choose_pid(From, PIDs)}
end.
new_connection(MyServer, Server, From, FromTo,
MaxS2SConnectionsNumber, MaxS2SConnectionsNumberPerNode) ->
Key = randoms:get_string(),
{ok, Pid} = ejabberd_s2s_out:start(
MyServer, Server, {new, Key}),
F = fun() ->
L = mnesia:read({s2s, FromTo}),
NeededConnections = needed_connections_number(L,
MaxS2SConnectionsNumber,
MaxS2SConnectionsNumberPerNode),
if NeededConnections > 0 ->
mnesia:write(#s2s{fromto = FromTo, pid = Pid,
key = Key}),
?INFO_MSG("New s2s connection started ~p", [Pid]),
Pid;
true -> choose_connection(From, L)
end
end,
TRes = mnesia:transaction(F),
case TRes of
{atomic, Pid} -> ejabberd_s2s_out:start_connection(Pid);
_ -> ejabberd_s2s_out:stop_connection(Pid)
end,
TRes.
max_s2s_connections_number({From, To}) ->
case acl:match_rule(From, max_s2s_connections,
jlib:make_jid(<<"">>, To, <<"">>))
of
Max when is_integer(Max) -> Max;
_ -> ?DEFAULT_MAX_S2S_CONNECTIONS_NUMBER
end.
max_s2s_connections_number_per_node({From, To}) ->
case acl:match_rule(From, max_s2s_connections_per_node,
jlib:make_jid(<<"">>, To, <<"">>))
of
Max when is_integer(Max) -> Max;
_ -> ?DEFAULT_MAX_S2S_CONNECTIONS_NUMBER_PER_NODE
end.
needed_connections_number(Ls, MaxS2SConnectionsNumber,
MaxS2SConnectionsNumberPerNode) ->
LocalLs = [L || L <- Ls, node(L#s2s.pid) == node()],
lists:min([MaxS2SConnectionsNumber - length(Ls),
MaxS2SConnectionsNumberPerNode - length(LocalLs)]).
%%--------------------------------------------------------------------
%% Function: is_service(From, To) -> true | false
%% Description: Return true if the destination must be considered as a
%% service.
%% --------------------------------------------------------------------
is_service(From, To) ->
LFromDomain = From#jid.lserver,
case ejabberd_config:get_local_option(
{route_subdomains, LFromDomain},
fun(s2s) -> s2s end) of
s2s -> % bypass RFC 3920 10.3
false;
undefined ->
Hosts = (?MYHOSTS),
P = fun (ParentDomain) ->
lists:member(ParentDomain, Hosts)
end,
lists:any(P, parent_domains(To#jid.lserver))
end.
parent_domains(Domain) ->
lists:foldl(fun (Label, []) -> [Label];
(Label, [Head | Tail]) ->
[<<Label/binary, ".", Head/binary>>, Head | Tail]
end,
[], lists:reverse(str:tokens(Domain, <<".">>))).
send_element(Pid, El) -> Pid ! {send_element, El}.
%%%----------------------------------------------------------------------
%%% ejabberd commands
commands() ->
[#ejabberd_commands{name = incoming_s2s_number,
tags = [stats, s2s],
desc =
"Number of incoming s2s connections on "
"the node",
module = ?MODULE, function = incoming_s2s_number,
args = [], result = {s2s_incoming, integer}},
#ejabberd_commands{name = outgoing_s2s_number,
tags = [stats, s2s],
desc =
"Number of outgoing s2s connections on "
"the node",
module = ?MODULE, function = outgoing_s2s_number,
args = [], result = {s2s_outgoing, integer}}].
incoming_s2s_number() ->
length(supervisor:which_children(ejabberd_s2s_in_sup)).
outgoing_s2s_number() ->
length(supervisor:which_children(ejabberd_s2s_out_sup)).
%%%----------------------------------------------------------------------
%%% Update Mnesia tables
update_tables() ->
case catch mnesia:table_info(s2s, type) of
bag -> ok;
{'EXIT', _} -> ok;
_ -> mnesia:delete_table(s2s)
end,
case catch mnesia:table_info(s2s, attributes) of
[fromto, node, key] ->
mnesia:transform_table(s2s, ignore, [fromto, pid, key]),
mnesia:clear_table(s2s);
[fromto, pid, key] -> ok;
{'EXIT', _} -> ok
end,
case lists:member(local_s2s, mnesia:system_info(tables)) of
true ->
mnesia:delete_table(local_s2s);
false ->
ok
end.
%% Check if host is in blacklist or white list
allow_host(MyServer, S2SHost) ->
allow_host2(MyServer, S2SHost) andalso
not is_temporarly_blocked(S2SHost).
allow_host2(MyServer, S2SHost) ->
Hosts = (?MYHOSTS),
case lists:dropwhile(fun (ParentDomain) ->
not lists:member(ParentDomain, Hosts)
end,
parent_domains(MyServer))
of
[MyHost | _] -> allow_host1(MyHost, S2SHost);
[] -> allow_host1(MyServer, S2SHost)
end.
allow_host1(MyHost, S2SHost) ->
case ejabberd_config:get_local_option(
{{s2s_host, S2SHost}, MyHost},
fun(deny) -> deny; (allow) -> allow end)
of
deny -> false;
allow -> true;
undefined ->
case ejabberd_config:get_local_option(
{s2s_default_policy, MyHost},
fun(deny) -> deny; (allow) -> allow end)
of
deny -> false;
_ ->
case ejabberd_hooks:run_fold(s2s_allow_host, MyHost,
allow, [MyHost, S2SHost])
of
deny -> false;
allow -> true;
_ -> true
end
end
end.
%% Get information about S2S connections of the specified type.
%% @spec (Type) -> [Info]
%% where Type = in | out
%% Info = [{InfoName::atom(), InfoValue::any()}]
get_info_s2s_connections(Type) ->
ChildType = case Type of
in -> ejabberd_s2s_in_sup;
out -> ejabberd_s2s_out_sup
end,
Connections = supervisor:which_children(ChildType),
get_s2s_info(Connections, Type).
get_s2s_info(Connections, Type) ->
complete_s2s_info(Connections, Type, []).
complete_s2s_info([], _, Result) -> Result;
complete_s2s_info([Connection | T], Type, Result) ->
{_, PID, _, _} = Connection,
State = get_s2s_state(PID),
complete_s2s_info(T, Type, [State | Result]).
-spec get_s2s_state(pid()) -> [{status, open | closed | error} | {s2s_pid, pid()}].
get_s2s_state(S2sPid) ->
Infos = case gen_fsm:sync_send_all_state_event(S2sPid,
get_state_infos)
of
{state_infos, Is} -> [{status, open} | Is];
{noproc, _} -> [{status, closed}]; %% Connection closed
{badrpc, _} -> [{status, error}]
end,
[{s2s_pid, S2sPid} | Infos].
