%%%----------------------------------------------------------------------
%%% File : mod_carboncopy.erl
%%% Author : Eric Cestari <ecestari@process-one.net>
%%% Purpose : Message Carbons XEP-0280 0.8
%%% Created : 5 May 2008 by Mickael Remond <mremond@process-one.net>
%%% Usage : Add the following line in modules section of ejabberd.yml:
%%% {mod_carboncopy, []}
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2016 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, '0.8'}).
-behavior(gen_mod).
%% API:
-export([start/2,
stop/1]).
-export([user_send_packet/4, user_receive_packet/5,
iq_handler2/3, iq_handler1/3, remove_connection/4,
is_carbon_copy/1, mod_opt_type/1, depends/2]).
-include("ejabberd.hrl").
-include("logger.hrl").
-include("jlib.hrl").
-define(PROCNAME, ?MODULE).
-callback init(binary(), gen_mod:opts()) -> any().
-callback enable(binary(), binary(), binary(), binary()) -> ok | {error, any()}.
-callback disable(binary(), binary(), binary()) -> ok | {error, any()}.
-callback list(binary(), binary()) -> [{binary(), binary()}].
is_carbon_copy(Packet) ->
is_carbon_copy(Packet, <<"sent">>) orelse
is_carbon_copy(Packet, <<"received">>).
is_carbon_copy(Packet, Direction) ->
case fxml:get_subtag(Packet, Direction) of
#xmlel{name = Direction, attrs = Attrs} ->
case fxml:get_attr_s(<<"xmlns">>, Attrs) of
?NS_CARBONS_2 -> true;
?NS_CARBONS_1 -> true;
_ -> false
end;
_ -> false
end.
start(Host, Opts) ->
IQDisc = gen_mod:get_opt(iqdisc, Opts,fun gen_iq_handler:check_type/1, one_queue),
mod_disco:register_feature(Host, ?NS_CARBONS_1),
mod_disco:register_feature(Host, ?NS_CARBONS_2),
Mod = gen_mod:db_mod(Host, ?MODULE),
Mod:init(Host, Opts),
ejabberd_hooks:add(unset_presence_hook,Host, ?MODULE, remove_connection, 10),
%% 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),
gen_iq_handler:add_iq_handler(ejabberd_sm, Host, ?NS_CARBONS_2, ?MODULE, iq_handler2, IQDisc),
gen_iq_handler:add_iq_handler(ejabberd_sm, Host, ?NS_CARBONS_1, ?MODULE, iq_handler1, IQDisc).
stop(Host) ->
gen_iq_handler:remove_iq_handler(ejabberd_sm, Host, ?NS_CARBONS_1),
gen_iq_handler:remove_iq_handler(ejabberd_sm, Host, ?NS_CARBONS_2),
mod_disco:unregister_feature(Host, ?NS_CARBONS_2),
mod_disco:unregister_feature(Host, ?NS_CARBONS_1),
%% 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(unset_presence_hook,Host, ?MODULE, remove_connection, 10).
iq_handler2(From, To, IQ) ->
iq_handler(From, To, IQ, ?NS_CARBONS_2).
iq_handler1(From, To, IQ) ->
iq_handler(From, To, IQ, ?NS_CARBONS_1).
iq_handler(From, _To,
#iq{type=set, lang = Lang,
sub_el = #xmlel{name = Operation} = SubEl} = IQ, CC)->
?DEBUG("carbons IQ received: ~p", [IQ]),
{U, S, R} = jid:tolower(From),
Result = case Operation of
<<"enable">>->
?INFO_MSG("carbons enabled for user ~s@~s/~s", [U,S,R]),
enable(S,U,R,CC);
<<"disable">>->
?INFO_MSG("carbons disabled for user ~s@~s/~s", [U,S,R]),
disable(S, U, R)
end,
case Result of
ok ->
?DEBUG("carbons IQ result: ok", []),
IQ#iq{type=result, sub_el=[]};
{error,_Error} ->
?ERROR_MSG("Error enabling / disabling carbons: ~p", [Result]),
Txt = <<"Database failure">>,
IQ#iq{type=error,sub_el = [SubEl, ?ERRT_INTERNAL_SERVER_ERROR(Lang, Txt)]}
end;
iq_handler(_From, _To, #iq{lang = Lang, sub_el = SubEl} = IQ, _CC)->
Txt = <<"Value 'get' of 'type' attribute is not allowed">>,
IQ#iq{type=error, sub_el = [SubEl, ?ERRT_NOT_ALLOWED(Lang, Txt)]}.
user_send_packet(Packet, _C2SState, From, To) ->
check_and_forward(From, To, Packet, sent).
user_receive_packet(Packet, _C2SState, JID, _From, To) ->
check_and_forward(JID, To, Packet, received).
% 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
check_and_forward(JID, To, Packet, Direction)->
case is_chat_message(Packet) andalso
fxml:get_subtag(Packet, <<"private">>) == false andalso
fxml:get_subtag(Packet, <<"no-copy">>) == false of
true ->
case is_carbon_copy(Packet) of
false ->
send_copies(JID, To, Packet, Direction),
Packet;
true ->
%% stop the hook chain, we don't want logging modules to duplicates
%% this message
{stop, Packet}
end;
_ ->
Packet
end.
remove_connection(User, Server, Resource, _Status)->
disable(Server, User, Resource),
ok.
%%% Internal
%% Direction = received | sent <received xmlns='urn:xmpp:carbons:1'/>
send_copies(JID, To, Packet, 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, R} of
{true, MaxRes} ->
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) ];
{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 (the one where R equals
%% MaxRes) in order to avoid duplicates.
[];
{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:map(fun({Dest,Version}) ->
{_, _, Resource} = jid:tolower(Dest),
?DEBUG("Sending: ~p =/= ~p", [R, Resource]),
Sender = jid:make({U, S, <<>>}),
%{xmlelement, N, A, C} = Packet,
New = build_forward_packet(JID, Packet, Sender, Dest, Direction, Version),
ejabberd_router:route(Sender, Dest, New)
end, TargetJIDs),
ok.
build_forward_packet(JID, Packet, Sender, Dest, Direction, ?NS_CARBONS_2) ->
#xmlel{name = <<"message">>,
attrs = [{<<"xmlns">>, <<"jabber:client">>},
{<<"type">>, message_type(Packet)},
{<<"from">>, jid:to_string(Sender)},
{<<"to">>, jid:to_string(Dest)}],
children = [
#xmlel{name = list_to_binary(atom_to_list(Direction)),
attrs = [{<<"xmlns">>, ?NS_CARBONS_2}],
children = [
#xmlel{name = <<"forwarded">>,
attrs = [{<<"xmlns">>, ?NS_FORWARD}],
children = [
complete_packet(JID, Packet, Direction)]}
]}
]};
build_forward_packet(JID, Packet, Sender, Dest, Direction, ?NS_CARBONS_1) ->
#xmlel{name = <<"message">>,
attrs = [{<<"xmlns">>, <<"jabber:client">>},
{<<"type">>, message_type(Packet)},
{<<"from">>, jid:to_string(Sender)},
{<<"to">>, jid:to_string(Dest)}],
children = [
#xmlel{name = list_to_binary(atom_to_list(Direction)),
attrs = [{<<"xmlns">>, ?NS_CARBONS_1}]},
#xmlel{name = <<"forwarded">>,
attrs = [{<<"xmlns">>, ?NS_FORWARD}],
children = [complete_packet(JID, Packet, Direction)]}
]}.
enable(Host, U, R, CC)->
?DEBUG("enabling for ~p", [U]),
Mod = gen_mod:db_mod(Host, ?MODULE),
Mod:enable(U, Host, R, CC).
disable(Host, U, R)->
?DEBUG("disabling for ~p", [U]),
Mod = gen_mod:db_mod(Host, ?MODULE),
Mod:disable(U, Host, R).
complete_packet(From, #xmlel{name = <<"message">>, attrs = OrigAttrs} = Packet, sent) ->
%% if this is a packet sent by user on this host, then Packet doesn't
%% include the 'from' attribute. We must add it.
Attrs = lists:keystore(<<"xmlns">>, 1, OrigAttrs, {<<"xmlns">>, <<"jabber:client">>}),
case proplists:get_value(<<"from">>, Attrs) of
undefined ->
Packet#xmlel{attrs = [{<<"from">>, jid:to_string(From)}|Attrs]};
_ ->
Packet#xmlel{attrs = Attrs}
end;
complete_packet(_From, #xmlel{name = <<"message">>, attrs=OrigAttrs} = Packet, received) ->
Attrs = lists:keystore(<<"xmlns">>, 1, OrigAttrs, {<<"xmlns">>, <<"jabber:client">>}),
Packet#xmlel{attrs = Attrs}.
message_type(#xmlel{attrs = Attrs}) ->
case fxml:get_attr(<<"type">>, Attrs) of
{value, Type} -> Type;
false -> <<"normal">>
end.
is_chat_message(#xmlel{name = <<"message">>} = Packet) ->
case message_type(Packet) of
<<"chat">> -> true;
<<"normal">> -> has_non_empty_body(Packet);
_ -> false
end;
is_chat_message(_Packet) -> false.
has_non_empty_body(Packet) ->
fxml:get_subtag_cdata(Packet, <<"body">>) =/= <<"">>.
%% list {resource, cc_version} with carbons enabled for given user and host
list(User, Server) ->
Mod = gen_mod:db_mod(Server, ?MODULE),
Mod:list(User, Server).
depends(_Host, _Opts) ->
[].
mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
mod_opt_type(db_type) -> fun(T) -> ejabberd_config:v_db(?MODULE, T) end;
mod_opt_type(_) -> [db_type, iqdisc].
