aboutsummaryrefslogtreecommitdiff
path: root/src/mod_carboncopy.erl
blob: 5839a65b29c08e28a335c6be015ae66a4e12acc7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
%%%----------------------------------------------------------------------
%%% 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_handler/1, remove_connection/4,
	 is_carbon_copy/1, mod_opt_type/1, depends/2]).

-include("ejabberd.hrl").
-include("logger.hrl").
-include("xmpp.hrl").
-define(PROCNAME, ?MODULE).

-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()}].

-spec is_carbon_copy(stanza()) -> boolean().
is_carbon_copy(#message{meta = #{carbon_copy := true}}) ->
    true;
is_carbon_copy(_) ->
    false.

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_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_handler, IQDisc).

stop(Host) ->
    gen_iq_handler:remove_iq_handler(ejabberd_sm, Host, ?NS_CARBONS_2),
    mod_disco:unregister_feature(Host, ?NS_CARBONS_2),
    %% 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).

-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{} ->
		     ?INFO_MSG("carbons enabled for user ~s@~s/~s", [U,S,R]),
		     enable(S, U, R, ?NS_CARBONS_2);
		 #carbons_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", []),
	    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(), jid(), jid()) ->
			      stanza() | {stop, stanza()}.
user_send_packet(Packet, _C2SState, From, To) ->
    check_and_forward(From, To, Packet, sent).

-spec user_receive_packet(stanza(), ejabberd_c2s:state(),
			  jid(), jid(), jid()) ->
				 stanza() | {stop, stanza()}.
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
-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_muc_pm(To, Packet) andalso
	xmpp:has_subtag(Packet, #carbons_private{}) == false andalso
	xmpp:has_subtag(Packet, #hint{type = '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.

-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(Sender, Dest, New)
	      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{xml_els = [xmpp:encode(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:db_mod(Host, ?MODULE),
    Mod:enable(U, Host, R, CC).

-spec disable(binary(), binary(), binary()) -> ok | {error, any()}.
disable(Host, U, R)->
    ?DEBUG("disabling for ~p", [U]),
    Mod = gen_mod:db_mod(Host, ?MODULE),
    Mod:disable(U, Host, R).

-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.

is_muc_pm(#jid{lresource = <<>>}, _Packet) ->
    false;
is_muc_pm(_To, Packet) ->
    xmpp:has_subtag(Packet, #muc_user{}).

-spec list(binary(), binary()) -> [{binary(), binary()}].
%% 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].