%%%----------------------------------------------------------------------
%%% 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) 2002-2018 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'}).
-behaviour(gen_mod).
%% API:
-export([start/2, stop/1, reload/3]).
-export([user_send_packet/1, user_receive_packet/1,
iq_handler/1, remove_connection/4, disco_features/5,
is_carbon_copy/1, mod_opt_type/1, depends/2, clean_cache/1,
mod_options/1]).
-include("logger.hrl").
-include("xmpp.hrl").
-include("mod_carboncopy.hrl").
-type direction() :: sent | received.
-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(), node()}].
-callback use_cache(binary()) -> boolean().
-callback cache_nodes(binary()) -> [node()].
-optional_callbacks([use_cache/1, cache_nodes/1]).
-spec is_carbon_copy(stanza()) -> boolean().
is_carbon_copy(#message{meta = #{carbon_copy := true}}) ->
true;
is_carbon_copy(_) ->
false.
start(Host, Opts) ->
ejabberd_hooks:add(disco_local_features, Host, ?MODULE, disco_features, 50),
Mod = gen_mod:ram_db_mod(Host, ?MODULE),
init_cache(Mod, Host, Opts),
Mod:init(Host, Opts),
clean_cache(),
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_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(unset_presence_hook,Host, ?MODULE, remove_connection, 10).
reload(Host, NewOpts, OldOpts) ->
NewMod = gen_mod:ram_db_mod(Host, NewOpts, ?MODULE),
OldMod = gen_mod:ram_db_mod(Host, OldOpts, ?MODULE),
if NewMod /= OldMod ->
NewMod:init(Host, NewOpts);
true ->
ok
end,
case use_cache(NewMod, Host) of
true ->
ets_cache:new(?CARBONCOPY_CACHE, cache_opts(NewOpts));
false ->
ok
end.
-spec disco_features({error, stanza_error()} | {result, [binary()]} | empty,
jid(), jid(), binary(), binary()) ->
{error, stanza_error()} | {result, [binary()]}.
disco_features({error, Err}, _From, _To, _Node, _Lang) ->
{error, Err};
disco_features(empty, _From, _To, <<"">>, _Lang) ->
{result, [?NS_CARBONS_2]};
disco_features({result, Feats}, _From, _To, <<"">>, _Lang) ->
{result, [?NS_CARBONS_2|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{} ->
?DEBUG("Carbons enabled for user ~s@~s/~s", [U,S,R]),
enable(S, U, R, ?NS_CARBONS_2);
#carbons_disable{} ->
?DEBUG("Carbons disabled for user ~s@~s/~s", [U,S,R]),
disable(S, U, R)
end,
case Result of
ok ->
?DEBUG("carbons IQ result: ok", []),
xmpp:make_iq_result(IQ);
{error,_Error} ->
?ERROR_MSG("Error enabling / disabling carbons: ~p", [Result]),
Txt = <<"Database failure">>,
xmpp:make_error(IQ, xmpp:err_internal_server_error(Txt, Lang))
end;
iq_handler(#iq{type = set, lang = Lang} = IQ) ->
Txt = <<"Only <enable/> or <disable/> tags are allowed">>,
xmpp:make_error(IQ, xmpp:err_bad_request(Txt, Lang));
iq_handler(#iq{type = get, lang = Lang} = IQ)->
Txt = <<"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({Packet, C2SState}) ->
From = xmpp:get_from(Packet),
To = xmpp:get_to(Packet),
case check_and_forward(From, To, Packet, sent) of
{stop, Pkt} -> {stop, {Pkt, C2SState}};
Pkt -> {Pkt, C2SState}
end.
-spec user_receive_packet({stanza(), ejabberd_c2s:state()})
-> {stanza(), ejabberd_c2s:state()} | {stop, {stanza(), ejabberd_c2s:state()}}.
user_receive_packet({Packet, #{jid := JID} = C2SState}) ->
To = xmpp:get_to(Packet),
case check_and_forward(JID, To, Packet, received) of
{stop, Pkt} -> {stop, {Pkt, C2SState}};
Pkt -> {Pkt, C2SState}
end.
% 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(), stanza(), direction()) ->
stanza() | {stop, stanza()}.
check_and_forward(JID, To, Packet, Direction)->
case is_chat_message(Packet) andalso
not is_received_muc_pm(To, Packet, Direction) andalso
not xmpp:has_subtag(Packet, #carbons_private{}) andalso
not xmpp:has_subtag(Packet, #hint{type = 'no-copy'}) 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.
-spec remove_connection(binary(), binary(), binary(), binary()) -> ok.
remove_connection(User, Server, Resource, _Status)->
disable(Server, User, Resource),
ok.
%%% Internal
%% Direction = received | sent <received xmlns='urn:xmpp:carbons:1'/>
-spec send_copies(jid(), jid(), message(), direction()) -> ok.
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, Packet} 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: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),
ejabberd_router:route(xmpp:set_from_to(New, Sender, Dest))
end, TargetJIDs),
ok.
-spec build_forward_packet(jid(), message(), jid(), jid(), direction()) -> message().
build_forward_packet(JID, #message{type = T} = Msg, Sender, Dest, Direction) ->
Forwarded = #forwarded{sub_els = [complete_packet(JID, Msg, Direction)]},
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 for ~p", [U]),
Mod = gen_mod:ram_db_mod(Host, ?MODULE),
case Mod:enable(U, Host, R, CC) of
ok ->
delete_cache(Mod, U, Host);
{error, _} = Err ->
Err
end.
-spec disable(binary(), binary(), binary()) -> ok | {error, any()}.
disable(Host, U, R)->
?DEBUG("disabling for ~p", [U]),
Mod = gen_mod:ram_db_mod(Host, ?MODULE),
Res = Mod:disable(U, Host, R),
delete_cache(Mod, U, Host),
Res.
-spec complete_packet(jid(), message(), direction()) -> message().
complete_packet(From, #message{from = undefined} = Msg, sent) ->
%% if this is a packet sent by user on this host, then Packet doesn't
%% include the 'from' attribute. We must add it.
Msg#message{from = From};
complete_packet(_From, Msg, _Direction) ->
Msg.
-spec is_chat_message(stanza()) -> boolean().
is_chat_message(#message{type = chat}) ->
true;
is_chat_message(#message{type = normal, body = [_|_]}) ->
true;
is_chat_message(_) ->
false.
-spec is_received_muc_pm(jid(), message(), direction()) -> boolean().
is_received_muc_pm(#jid{lresource = <<>>}, _Packet, _Direction) ->
false;
is_received_muc_pm(_To, _Packet, sent) ->
false;
is_received_muc_pm(_To, Packet, received) ->
xmpp:has_subtag(Packet, #muc_user{}).
-spec list(binary(), binary()) -> [{Resource :: binary(), Namespace :: binary()}].
list(User, Server) ->
Mod = gen_mod:ram_db_mod(Server, ?MODULE),
case use_cache(Mod, Server) of
true ->
case ets_cache:lookup(
?CARBONCOPY_CACHE, {User, Server},
fun() ->
case Mod:list(User, Server) of
{ok, L} when L /= [] -> {ok, L};
_ -> error
end
end) of
{ok, L} -> [{Resource, NS} || {Resource, NS, _} <- L];
error -> []
end;
false ->
case Mod:list(User, Server) of
{ok, L} -> [{Resource, NS} || {Resource, NS, _} <- L];
error -> []
end
end.
-spec init_cache(module(), binary(), gen_mod:opts()) -> ok.
init_cache(Mod, Host, Opts) ->
case use_cache(Mod, Host) of
true ->
ets_cache:new(?CARBONCOPY_CACHE, cache_opts(Opts));
false ->
ets_cache:delete(?CARBONCOPY_CACHE)
end.
-spec cache_opts(gen_mod:opts()) -> [proplists:property()].
cache_opts(Opts) ->
MaxSize = gen_mod:get_opt(cache_size, Opts),
CacheMissed = gen_mod:get_opt(cache_missed, Opts),
LifeTime = case gen_mod:get_opt(cache_life_time, Opts) of
infinity -> infinity;
I -> timer:seconds(I)
end,
[{max_size, MaxSize}, {cache_missed, CacheMissed}, {life_time, LifeTime}].
-spec use_cache(module(), binary()) -> boolean().
use_cache(Mod, Host) ->
case erlang:function_exported(Mod, use_cache, 1) of
true -> Mod:use_cache(Host);
false -> gen_mod:get_module_opt(Host, ?MODULE, use_cache)
end.
-spec cache_nodes(module(), binary()) -> [node()].
cache_nodes(Mod, Host) ->
case erlang:function_exported(Mod, cache_nodes, 1) of
true -> Mod:cache_nodes(Host);
false -> ejabberd_cluster:get_nodes()
end.
-spec clean_cache(node()) -> ok.
clean_cache(Node) ->
ets_cache:filter(
?CARBONCOPY_CACHE,
fun(_, error) ->
false;
(_, {ok, L}) ->
not lists:any(fun({_, _, N}) -> N == Node end, L)
end).
-spec clean_cache() -> ok.
clean_cache() ->
ejabberd_cluster:eval_everywhere(?MODULE, clean_cache, [node()]).
-spec delete_cache(module(), binary(), binary()) -> ok.
delete_cache(Mod, User, Server) ->
case use_cache(Mod, Server) of
true ->
ets_cache:delete(?CARBONCOPY_CACHE, {User, Server},
cache_nodes(Mod, Server));
false ->
ok
end.
depends(_Host, _Opts) ->
[].
mod_opt_type(ram_db_type) -> fun(T) -> ejabberd_config:v_db(?MODULE, T) end;
mod_opt_type(O) when O == use_cache; O == cache_missed ->
fun(B) when is_boolean(B) -> B end;
mod_opt_type(O) when O == cache_size; O == cache_life_time ->
fun(I) when is_integer(I), I>0 -> I;
(unlimited) -> infinity;
(infinity) -> infinity
end.
mod_options(Host) ->
[{ram_db_type, ejabberd_config:default_ram_db(Host, ?MODULE)},
{use_cache, ejabberd_config:use_cache(Host)},
{cache_size, ejabberd_config:cache_size(Host)},
{cache_missed, ejabberd_config:cache_missed(Host)},
{cache_life_time, ejabberd_config:cache_life_time(Host)}].
