%%%---------------------------------------------------------------------- %%% File : mod_carboncopy.erl %%% Author : Eric Cestari %%% Purpose : Message Carbons XEP-0280 0.8 %%% Created : 5 May 2008 by Mickael Remond %%% Usage : Add the following line in modules section of ejabberd.yml: %%% {mod_carboncopy, []} %%% %%% %%% ejabberd, Copyright (C) 2002-2020 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_carboncopy). -author ('ecestari@process-one.net'). -protocol({xep, 280, '0.13.2'}). -behaviour(gen_mod). %% API: -export([start/2, stop/1, reload/3]). -export([user_send_packet/1, user_receive_packet/1, iq_handler/1, disco_features/5, depends/2, mod_options/1, mod_doc/0]). -export([c2s_copy_session/2, c2s_session_opened/1, c2s_session_resumed/1]). %% For debugging purposes -export([list/2]). -include("logger.hrl"). -include("xmpp.hrl"). -include("translate.hrl"). -type direction() :: sent | received. -type c2s_state() :: ejabberd_c2s:state(). start(Host, _Opts) -> ejabberd_hooks:add(disco_local_features, Host, ?MODULE, disco_features, 50), %% why priority 89: to define clearly that we must run BEFORE mod_logdb hook (90) ejabberd_hooks:add(user_send_packet,Host, ?MODULE, user_send_packet, 89), ejabberd_hooks:add(user_receive_packet,Host, ?MODULE, user_receive_packet, 89), ejabberd_hooks:add(c2s_copy_session, Host, ?MODULE, c2s_copy_session, 50), ejabberd_hooks:add(c2s_session_resumed, Host, ?MODULE, c2s_session_resumed, 50), ejabberd_hooks:add(c2s_session_opened, Host, ?MODULE, c2s_session_opened, 50), gen_iq_handler:add_iq_handler(ejabberd_sm, Host, ?NS_CARBONS_2, ?MODULE, iq_handler). stop(Host) -> gen_iq_handler:remove_iq_handler(ejabberd_sm, Host, ?NS_CARBONS_2), ejabberd_hooks:delete(disco_local_features, Host, ?MODULE, disco_features, 50), %% why priority 89: to define clearly that we must run BEFORE mod_logdb hook (90) ejabberd_hooks:delete(user_send_packet,Host, ?MODULE, user_send_packet, 89), ejabberd_hooks:delete(user_receive_packet,Host, ?MODULE, user_receive_packet, 89), ejabberd_hooks:delete(c2s_copy_session, Host, ?MODULE, c2s_copy_session, 50), ejabberd_hooks:delete(c2s_session_resumed, Host, ?MODULE, c2s_session_resumed, 50), ejabberd_hooks:delete(c2s_session_opened, Host, ?MODULE, c2s_session_opened, 50). reload(_Host, _NewOpts, _OldOpts) -> ok. -spec disco_features({error, stanza_error()} | {result, [binary()]} | empty, jid(), jid(), binary(), binary()) -> {error, stanza_error()} | {result, [binary()]}. disco_features(empty, From, To, <<"">>, Lang) -> disco_features({result, []}, From, To, <<"">>, Lang); disco_features({result, Feats}, _From, _To, <<"">>, _Lang) -> {result, [?NS_CARBONS_2,?NS_CARBONS_RULES_0|Feats]}; disco_features(Acc, _From, _To, _Node, _Lang) -> Acc. -spec iq_handler(iq()) -> iq(). iq_handler(#iq{type = set, lang = Lang, from = From, sub_els = [El]} = IQ) when is_record(El, carbons_enable); is_record(El, carbons_disable) -> {U, S, R} = jid:tolower(From), Result = case El of #carbons_enable{} -> enable(S, U, R, ?NS_CARBONS_2); #carbons_disable{} -> disable(S, U, R) end, case Result of ok -> xmpp:make_iq_result(IQ); {error, _} -> Txt = ?T("Database failure"), xmpp:make_error(IQ, xmpp:err_internal_server_error(Txt, Lang)) end; iq_handler(#iq{type = set, lang = Lang} = IQ) -> Txt = ?T("Only or tags are allowed"), xmpp:make_error(IQ, xmpp:err_bad_request(Txt, Lang)); iq_handler(#iq{type = get, lang = Lang} = IQ)-> Txt = ?T("Value 'get' of 'type' attribute is not allowed"), xmpp:make_error(IQ, xmpp:err_not_allowed(Txt, Lang)). -spec user_send_packet({stanza(), ejabberd_c2s:state()}) -> {stanza(), ejabberd_c2s:state()} | {stop, {stanza(), ejabberd_c2s:state()}}. user_send_packet({#message{meta = #{carbon_copy := true}}, _C2SState} = Acc) -> %% Stop the hook chain, we don't want logging modules to duplicate this %% message. {stop, Acc}; user_send_packet({#message{from = From, to = To} = Msg, C2SState}) -> {check_and_forward(From, To, Msg, sent), C2SState}; user_send_packet(Acc) -> Acc. -spec user_receive_packet({stanza(), ejabberd_c2s:state()}) -> {stanza(), ejabberd_c2s:state()} | {stop, {stanza(), ejabberd_c2s:state()}}. user_receive_packet({#message{meta = #{carbon_copy := true}}, _C2SState} = Acc) -> %% Stop the hook chain, we don't want logging modules to duplicate this %% message. {stop, Acc}; user_receive_packet({#message{to = To} = Msg, #{jid := JID} = C2SState}) -> {check_and_forward(JID, To, Msg, received), C2SState}; user_receive_packet(Acc) -> Acc. -spec c2s_copy_session(c2s_state(), c2s_state()) -> c2s_state(). c2s_copy_session(State, #{user := U, server := S, resource := R}) -> case ejabberd_sm:get_user_info(U, S, R) of offline -> State; Info -> case lists:keyfind(carboncopy, 1, Info) of {_, CC} -> State#{carboncopy => CC}; false -> State end end. -spec c2s_session_resumed(c2s_state()) -> c2s_state(). c2s_session_resumed(#{user := U, server := S, resource := R, carboncopy := CC} = State) -> ejabberd_sm:set_user_info(U, S, R, carboncopy, CC), maps:remove(carboncopy, State); c2s_session_resumed(State) -> State. -spec c2s_session_opened(c2s_state()) -> c2s_state(). c2s_session_opened(State) -> maps:remove(carboncopy, State). % Modified from original version: % - registered to the user_send_packet hook, to be called only once even for multicast % - do not support "private" message mode, and do not modify the original packet in any way % - we also replicate "read" notifications -spec check_and_forward(jid(), jid(), message(), direction()) -> message(). check_and_forward(JID, To, Msg, Direction)-> case (is_chat_message(Msg) orelse is_received_muc_invite(Msg, Direction)) andalso not is_received_muc_pm(To, Msg, Direction) andalso not xmpp:has_subtag(Msg, #carbons_private{}) andalso not xmpp:has_subtag(Msg, #hint{type = 'no-copy'}) of true -> send_copies(JID, To, Msg, Direction); false -> ok end, Msg. %%% Internal %% Direction = received | sent -spec send_copies(jid(), jid(), message(), direction()) -> ok. send_copies(JID, To, Msg, Direction)-> {U, S, R} = jid:tolower(JID), PrioRes = ejabberd_sm:get_user_present_resources(U, S), {_, AvailRs} = lists:unzip(PrioRes), {MaxPrio, _MaxRes} = case catch lists:max(PrioRes) of {Prio, Res} -> {Prio, Res}; _ -> {0, undefined} end, %% unavailable resources are handled like bare JIDs IsBareTo = case {Direction, To} of {received, #jid{lresource = <<>>}} -> true; {received, #jid{lresource = LRes}} -> not lists:member(LRes, AvailRs); _ -> false end, %% list of JIDs that should receive a carbon copy of this message (excluding the %% receiver(s) of the original message TargetJIDs = case {IsBareTo, Msg} of {true, #message{meta = #{sm_copy := true}}} -> %% The message was sent to our bare JID, and we currently have %% multiple resources with the same highest priority, so the session %% manager routes the message to each of them. We create carbon %% copies only from one of those resources in order to avoid %% duplicates. []; {true, _} -> OrigTo = fun(Res) -> lists:member({MaxPrio, Res}, PrioRes) end, [ {jid:make({U, S, CCRes}), CC_Version} || {CCRes, CC_Version} <- list(U, S), lists:member(CCRes, AvailRs), not OrigTo(CCRes) ]; {false, _} -> [ {jid:make({U, S, CCRes}), CC_Version} || {CCRes, CC_Version} <- list(U, S), lists:member(CCRes, AvailRs), CCRes /= R ] %TargetJIDs = lists:delete(JID, [ jid:make({U, S, CCRes}) || CCRes <- list(U, S) ]), end, lists:foreach( fun({Dest, _Version}) -> {_, _, Resource} = jid:tolower(Dest), ?DEBUG("Sending: ~p =/= ~p", [R, Resource]), Sender = jid:make({U, S, <<>>}), New = build_forward_packet(Msg, Sender, Dest, Direction), ejabberd_router:route(xmpp:set_from_to(New, Sender, Dest)) end, TargetJIDs). -spec build_forward_packet(message(), jid(), jid(), direction()) -> message(). build_forward_packet(#message{type = T} = Msg, Sender, Dest, Direction) -> Forwarded = #forwarded{sub_els = [Msg]}, Carbon = case Direction of sent -> #carbons_sent{forwarded = Forwarded}; received -> #carbons_received{forwarded = Forwarded} end, #message{from = Sender, to = Dest, type = T, sub_els = [Carbon], meta = #{carbon_copy => true}}. -spec enable(binary(), binary(), binary(), binary()) -> ok | {error, any()}. enable(Host, U, R, CC)-> ?DEBUG("Enabling carbons for ~ts@~ts/~ts", [U, Host, R]), case ejabberd_sm:set_user_info(U, Host, R, carboncopy, CC) of ok -> ok; {error, Reason} = Err -> ?ERROR_MSG("Failed to enable carbons for ~ts@~ts/~ts: ~p", [U, Host, R, Reason]), Err end. -spec disable(binary(), binary(), binary()) -> ok | {error, any()}. disable(Host, U, R)-> ?DEBUG("Disabling carbons for ~ts@~ts/~ts", [U, Host, R]), case ejabberd_sm:del_user_info(U, Host, R, carboncopy) of ok -> ok; {error, notfound} -> ok; {error, Reason} = Err -> ?ERROR_MSG("Failed to disable carbons for ~ts@~ts/~ts: ~p", [U, Host, R, Reason]), Err end. -spec is_chat_message(message()) -> boolean(). is_chat_message(#message{type = chat}) -> true; is_chat_message(#message{type = normal, body = [_|_]}) -> true; is_chat_message(#message{type = Type} = Msg) when Type == chat; Type == normal -> has_chatstate(Msg) orelse xmpp:has_subtag(Msg, #receipt_response{}); is_chat_message(_) -> false. -spec is_received_muc_invite(message(), direction()) -> boolean(). is_received_muc_invite(_Msg, sent) -> false; is_received_muc_invite(Msg, received) -> case xmpp:get_subtag(Msg, #muc_user{}) of #muc_user{invites = [_|_]} -> true; _ -> xmpp:has_subtag(Msg, #x_conference{jid = jid:make(<<"">>)}) end. -spec is_received_muc_pm(jid(), message(), direction()) -> boolean(). is_received_muc_pm(#jid{lresource = <<>>}, _Msg, _Direction) -> false; is_received_muc_pm(_To, _Msg, sent) -> false; is_received_muc_pm(_To, Msg, received) -> xmpp:has_subtag(Msg, #muc_user{}). -spec has_chatstate(message()) -> boolean(). has_chatstate(#message{sub_els = Els}) -> lists:any(fun(El) -> xmpp:get_ns(El) == ?NS_CHATSTATES end, Els). -spec list(binary(), binary()) -> [{Resource :: binary(), Namespace :: binary()}]. list(User, Server) -> lists:filtermap( fun({Resource, Info}) -> case lists:keyfind(carboncopy, 1, Info) of {_, NS} -> {true, {Resource, NS}}; false -> false end end, ejabberd_sm:get_user_info(User, Server)). depends(_Host, _Opts) -> []. mod_options(_) -> []. mod_doc() -> #{desc => ?T("The module implements https://xmpp.org/extensions/xep-0280.html" "[XEP-0280: Message Carbons]. " "The module broadcasts messages on all connected " "user resources (devices).")}.