132 lines
3.8 KiB
Erlang
132 lines
3.8 KiB
Erlang
%%%----------------------------------------------------------------------
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%%% File : mod_pres_counter.erl
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%%% Author : Ahmed Omar
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%%% Purpose : Presence subscription flood prevention
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%%% Created : 23 Sep 2010 by Ahmed Omar
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%%%
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%%%
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%%% ejabberd, Copyright (C) 2002-2019 ProcessOne
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%%%
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%%% This program is free software; you can redistribute it and/or
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%%% modify it under the terms of the GNU General Public License as
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%%% published by the Free Software Foundation; either version 2 of the
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%%% License, or (at your option) any later version.
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%%%
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%%% This program is distributed in the hope that it will be useful,
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%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
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%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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%%% General Public License for more details.
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%%%
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%%% You should have received a copy of the GNU General Public License along
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%%% with this program; if not, write to the Free Software Foundation, Inc.,
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%%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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%%%
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%%%----------------------------------------------------------------------
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-module(mod_pres_counter).
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-behaviour(gen_mod).
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-export([start/2, stop/1, reload/3, check_packet/4,
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mod_opt_type/1, mod_options/1, depends/2]).
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-include("logger.hrl").
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-include("xmpp.hrl").
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-record(pres_counter,
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{dir, start, count, logged = false}).
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start(Host, _Opts) ->
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ejabberd_hooks:add(privacy_check_packet, Host, ?MODULE,
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check_packet, 25),
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ok.
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stop(Host) ->
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ejabberd_hooks:delete(privacy_check_packet, Host,
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?MODULE, check_packet, 25),
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ok.
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reload(_Host, _NewOpts, _OldOpts) ->
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ok.
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depends(_Host, _Opts) ->
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[].
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-spec check_packet(allow | deny, ejabberd_c2s:state() | jid(),
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stanza(), in | out) -> allow | deny.
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check_packet(Acc, #{jid := JID}, Packet, Dir) ->
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check_packet(Acc, JID, Packet, Dir);
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check_packet(_, #jid{lserver = LServer},
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#presence{from = From, to = To, type = Type}, Dir) ->
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IsSubscription = case Type of
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subscribe -> true;
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subscribed -> true;
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unsubscribe -> true;
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unsubscribed -> true;
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_ -> false
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end,
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if IsSubscription ->
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JID = case Dir of
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in -> To;
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out -> From
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end,
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update(LServer, JID, Dir);
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true -> allow
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end;
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check_packet(Acc, _, _, _) ->
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Acc.
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update(Server, JID, Dir) ->
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StormCount = gen_mod:get_module_opt(Server, ?MODULE, count),
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TimeInterval = gen_mod:get_module_opt(Server, ?MODULE, interval),
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TimeStamp = erlang:system_time(second),
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case read(Dir) of
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undefined ->
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write(Dir,
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#pres_counter{dir = Dir, start = TimeStamp, count = 1}),
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allow;
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#pres_counter{start = TimeStart, count = Count,
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logged = Logged} =
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R ->
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if TimeStamp - TimeStart > TimeInterval ->
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write(Dir,
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R#pres_counter{start = TimeStamp, count = 1}),
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allow;
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(Count =:= StormCount) and Logged -> {stop, deny};
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Count =:= StormCount ->
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write(Dir, R#pres_counter{logged = true}),
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case Dir of
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in ->
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?WARNING_MSG("User ~s is being flooded, ignoring received "
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"presence subscriptions",
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[jid:encode(JID)]);
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out ->
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IP = ejabberd_sm:get_user_ip(JID#jid.luser,
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JID#jid.lserver,
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JID#jid.lresource),
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?WARNING_MSG("Flooder detected: ~s, on IP: ~s ignoring "
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"sent presence subscriptions~n",
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[jid:encode(JID),
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misc:ip_to_list(IP)])
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end,
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{stop, deny};
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true ->
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write(Dir,
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R#pres_counter{start = TimeStamp, count = Count + 1}),
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allow
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end
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end.
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read(K) -> get({pres_counter, K}).
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write(K, V) -> put({pres_counter, K}, V).
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mod_opt_type(count) ->
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fun (I) when is_integer(I), I > 0 -> I end;
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mod_opt_type(interval) ->
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fun (I) when is_integer(I), I > 0 -> I end.
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mod_options(_) ->
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[{count, 5}, {interval, 60}].
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