%%%-------------------------------------------------------------------
%%% @author Evgeny Khramtsov <ekhramtsov@process-one.net>
%%% @copyright (C) 2014, Evgeny Khramtsov
%%% @doc
%%%
%%% @end
%%% Created : 15 Aug 2014 by Evgeny Khramtsov <ekhramtsov@process-one.net>
%%%
%%% ejabberd, Copyright (C) 2014-2015 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(mod_fail2ban).
-behaviour(gen_mod).
-behaviour(gen_server).
%% API
-export([start_link/2, start/2, stop/1, c2s_auth_result/4, check_bl_c2s/3]).
-export([init/1, handle_call/3, handle_cast/2,
handle_info/2, terminate/2, code_change/3,
mod_opt_type/1]).
-include_lib("stdlib/include/ms_transform.hrl").
-include("ejabberd.hrl").
-include("logger.hrl").
-define(C2S_AUTH_BAN_LIFETIME, 3600). %% 1 hour
-define(C2S_MAX_AUTH_FAILURES, 20).
-define(CLEAN_INTERVAL, timer:minutes(10)).
-record(state, {host = <<"">> :: binary()}).
%%%===================================================================
%%% API
%%%===================================================================
start_link(Host, Opts) ->
Proc = gen_mod:get_module_proc(Host, ?MODULE),
gen_server:start_link({local, Proc}, ?MODULE, [Host, Opts], []).
c2s_auth_result(false, _User, LServer, {Addr, _Port}) ->
case is_whitelisted(LServer, Addr) of
true ->
ok;
false ->
BanLifetime = gen_mod:get_module_opt(
LServer, ?MODULE, c2s_auth_ban_lifetime,
fun(T) when is_integer(T), T > 0 -> T end,
?C2S_AUTH_BAN_LIFETIME),
MaxFailures = gen_mod:get_module_opt(
LServer, ?MODULE, c2s_max_auth_failures,
fun(I) when is_integer(I), I > 0 -> I end,
?C2S_MAX_AUTH_FAILURES),
UnbanTS = unban_timestamp(BanLifetime),
case ets:lookup(failed_auth, Addr) of
[{Addr, N, _, _}] ->
ets:insert(failed_auth, {Addr, N+1, UnbanTS, MaxFailures});
[] ->
ets:insert(failed_auth, {Addr, 1, UnbanTS, MaxFailures})
end
end;
c2s_auth_result(true, _User, _Server, _AddrPort) ->
ok.
check_bl_c2s(_Acc, Addr, Lang) ->
case ets:lookup(failed_auth, Addr) of
[{Addr, N, TS, MaxFailures}] when N >= MaxFailures ->
case TS > now() of
true ->
IP = jlib:ip_to_list(Addr),
UnbanDate = format_date(
calendar:now_to_universal_time(TS)),
LogReason = io_lib:fwrite(
"Too many (~p) failed authentications "
"from this IP address (~s). The address "
"will be unblocked at ~s UTC",
[N, IP, UnbanDate]),
ReasonT = io_lib:fwrite(
translate:translate(
Lang,
<<"Too many (~p) failed authentications "
"from this IP address (~s). The address "
"will be unblocked at ~s UTC">>),
[N, IP, UnbanDate]),
{stop, {true, LogReason, ReasonT}};
false ->
ets:delete(failed_auth, Addr),
false
end;
_ ->
false
end.
%%====================================================================
%% gen_mod callbacks
%%====================================================================
start(Host, Opts) ->
catch ets:new(failed_auth, [named_table, public]),
Proc = gen_mod:get_module_proc(Host, ?MODULE),
ChildSpec = {Proc, {?MODULE, start_link, [Host, Opts]},
transient, 1000, worker, [?MODULE]},
supervisor:start_child(ejabberd_sup, ChildSpec).
stop(Host) ->
Proc = gen_mod:get_module_proc(Host, ?MODULE),
supervisor:terminate_child(ejabberd_sup, Proc),
supervisor:delete_child(ejabberd_sup, Proc).
%%%===================================================================
%%% gen_server callbacks
%%%===================================================================
init([Host, _Opts]) ->
ejabberd_hooks:add(c2s_auth_result, Host, ?MODULE, c2s_auth_result, 100),
ejabberd_hooks:add(check_bl_c2s, ?MODULE, check_bl_c2s, 100),
erlang:send_after(?CLEAN_INTERVAL, self(), clean),
{ok, #state{host = Host}}.
handle_call(_Request, _From, State) ->
Reply = ok,
{reply, Reply, State}.
handle_cast(_Msg, State) ->
?ERROR_MSG("got unexpected cast = ~p", [_Msg]),
{noreply, State}.
handle_info(clean, State) ->
?DEBUG("cleaning ~p ETS table", [failed_auth]),
Now = now(),
ets:select_delete(
failed_auth,
ets:fun2ms(fun({_, _, UnbanTS, _}) -> UnbanTS =< Now end)),
erlang:send_after(?CLEAN_INTERVAL, self(), clean),
{noreply, State};
handle_info(_Info, State) ->
?ERROR_MSG("got unexpected info = ~p", [_Info]),
{noreply, State}.
terminate(_Reason, #state{host = Host}) ->
ejabberd_hooks:delete(c2s_auth_result, Host, ?MODULE, c2s_auth_result, 100),
case is_loaded_at_other_hosts(Host) of
true ->
ok;
false ->
ejabberd_hooks:delete(check_bl_c2s, ?MODULE, check_bl_c2s, 100),
ets:delete(failed_auth)
end.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%%===================================================================
%%% Internal functions
%%%===================================================================
is_whitelisted(Host, Addr) ->
Access = gen_mod:get_module_opt(Host, ?MODULE, access,
fun(A) when is_atom(A) -> A end,
none),
acl:match_rule(Host, Access, Addr) == allow.
unban_timestamp(BanLifetime) ->
{MegaSecs, MSecs, USecs} = now(),
UnbanSecs = MegaSecs * 1000000 + MSecs + BanLifetime,
{UnbanSecs div 1000000, UnbanSecs rem 1000000, USecs}.
is_loaded_at_other_hosts(Host) ->
lists:any(
fun(VHost) when VHost == Host ->
false;
(VHost) ->
gen_mod:is_loaded(VHost, ?MODULE)
end, ?MYHOSTS).
format_date({{Year, Month, Day}, {Hour, Minute, Second}}) ->
io_lib:format("~2..0w:~2..0w:~2..0w ~2..0w.~2..0w.~4..0w",
[Hour, Minute, Second, Day, Month, Year]).
mod_opt_type(access) ->
fun (A) when is_atom(A) -> A end;
mod_opt_type(c2s_auth_ban_lifetime) ->
fun (T) when is_integer(T), T > 0 -> T end;
mod_opt_type(c2s_max_auth_failures) ->
fun (I) when is_integer(I), I > 0 -> I end;
mod_opt_type(_) ->
[access, c2s_auth_ban_lifetime, c2s_max_auth_failures].
