Merge pull request #298 from weiss/csi

Add support for XEP-0352: Client State Indication (CSI)

11 files changed, 633 insertions, 119 deletions

diff --git a/doc/guide.tex b/doc/guide.tex
index 8e2b91049..27fcfc181 100644
--- a/doc/guide.tex
+++ b/doc/guide.tex
@@ -66,6 +66,7 @@
 \newcommand{\module}[1]{\texttt{#1}}
 \newcommand{\modadhoc}{\module{mod\_adhoc}}
 \newcommand{\modannounce}{\module{mod\_announce}}
+\newcommand{\modclientstate}{\module{mod\_client\_state}}
 \newcommand{\modblocking}{\module{mod\_blocking}}
 \newcommand{\modcaps}{\module{mod\_caps}}
 \newcommand{\modcarboncopy}{\module{mod\_carboncopy}}
@@ -2781,6 +2782,7 @@ The following table lists all modules included in \ejabberd{}.
     \hline \modblocking{} & Simple Communications Blocking (\xepref{0191}) & \modprivacy{} \\
     \hline \modcaps{} &  Entity Capabilities (\xepref{0115}) & \\
     \hline \modcarboncopy{} & Message Carbons (\xepref{0280}) & \\
+    \hline \ahrefloc{modclientstate}{\modclientstate{}} & Filter stanzas for inactive clients &  \\
     \hline \modconfigure{} & Server configuration using Ad-Hoc & \modadhoc{} \\
     \hline \ahrefloc{moddisco}{\moddisco{}} & Service Discovery (\xepref{0030}) &  \\
     \hline \ahrefloc{modecho}{\modecho{}} & Echoes XMPP stanzas &  \\
@@ -3001,6 +3003,38 @@ Note that \modannounce{} can be resource intensive on large
 deployments as it can broadcast lot of messages. This module should be
 disabled for instances of \ejabberd{} with hundreds of thousands users.
 
+\makesubsection{modclientstate}{\modclientstate{}}
+\ind{modules!\modclientstate{}}\ind{Client State Indication}
+\ind{protocols!XEP-0352: Client State Indication}
+
+This module allows for queueing or dropping certain types of stanzas
+when a client indicates that the user is not actively using the client
+at the moment (see \xepref{0352}). This can save bandwidth and
+resources.
+
+Options:
+\begin{description}
+\titem{drop\_chat\_states: true|false} \ind{options!drop\_chat\_states}
+  Drop most "standalone" Chat State Notifications (as defined in
+  \xepref{0085}) while a client indicates inactivity. The default value
+  is \term{false}.
+\titem{queue\_presence: true|false} \ind{options!queue\_presence}
+  While a client is inactive, queue presence stanzas that indicate
+  (un)availability. The latest queued stanza of each contact is
+  delivered as soon as the client becomes active again. The default
+  value is \term{false}.
+\end{description}
+
+Example:
+\begin{verbatim}
+modules:
+  ...
+  mod_client_state:
+    drop_chat_states: true
+    queue_presence: true
+  ...
+\end{verbatim}
+
 \makesubsection{moddisco}{\moddisco{}}
 \ind{modules!\moddisco{}}
 \ind{protocols!XEP-0030: Service Discovery}
diff --git a/ejabberd.yml.example b/ejabberd.yml.example
index 8f108bf52..4755a7d44 100644
--- a/ejabberd.yml.example
+++ b/ejabberd.yml.example
@@ -558,6 +558,9 @@ modules:
   mod_blocking: {} # requires mod_privacy
   mod_caps: {}
   mod_carboncopy: {}
+  mod_client_state:
+    drop_chat_states: true
+    queue_presence: false
   mod_configure: {} # requires mod_adhoc
   mod_disco: {}
   ## mod_echo: {}
diff --git a/include/ns.hrl b/include/ns.hrl
index 6eb54fc3d..3ec19aca8 100644
--- a/include/ns.hrl
+++ b/include/ns.hrl
@@ -147,5 +147,6 @@
 -define(NS_CARBONS_2, <<"urn:xmpp:carbons:2">>).
 -define(NS_CARBONS_1, <<"urn:xmpp:carbons:1">>).
 -define(NS_FORWARD, <<"urn:xmpp:forward:0">>).
+-define(NS_CLIENT_STATE,  <<"urn:xmpp:csi:0">>).
 -define(NS_STREAM_MGMT_2,  <<"urn:xmpp:sm:2">>).
 -define(NS_STREAM_MGMT_3,  <<"urn:xmpp:sm:3">>).
diff --git a/src/ejabberd_c2s.erl b/src/ejabberd_c2s.erl
index 87f1bbdfb..cb6f9e6d8 100644
--- a/src/ejabberd_c2s.erl
+++ b/src/ejabberd_c2s.erl
@@ -108,6 +108,8 @@
 		auth_module = unknown,
 		ip,
 		aux_fields = [],
+		csi_state = active,
+		csi_queue = [],
 		mgmt_state,
 		mgmt_xmlns,
 		mgmt_queue,
@@ -475,6 +477,10 @@ wait_for_stream({xmlstreamstart, _Name, Attrs}, StateData) ->
 					      false ->
 						  []
 					    end,
+					ClientStateFeature =
+					    [#xmlel{name = <<"csi">>,
+						    attrs = [{<<"xmlns">>, ?NS_CLIENT_STATE}],
+						    children = []}],
 					StreamFeatures = [#xmlel{name = <<"bind">>,
 								attrs = [{<<"xmlns">>, ?NS_BIND}],
 								children = []},
@@ -484,6 +490,7 @@ wait_for_stream({xmlstreamstart, _Name, Attrs}, StateData) ->
 							    ++
 							    RosterVersioningFeature ++
 							    StreamManagementFeature ++
+							    ClientStateFeature ++
 							    ejabberd_hooks:run_fold(c2s_stream_features,
 								Server, [], [Server]),
 					send_element(StateData,
@@ -1165,6 +1172,17 @@ wait_for_session(closed, StateData) ->
 session_established({xmlstreamelement, #xmlel{name = Name} = El}, StateData)
     when ?IS_STREAM_MGMT_TAG(Name) ->
     fsm_next_state(session_established, dispatch_stream_mgmt(El, StateData));
+session_established({xmlstreamelement,
+		     #xmlel{name = <<"active">>,
+			    attrs = [{<<"xmlns">>, ?NS_CLIENT_STATE}]}},
+		    StateData) ->
+    NewStateData = csi_queue_flush(StateData),
+    fsm_next_state(session_established, NewStateData#state{csi_state = active});
+session_established({xmlstreamelement,
+		     #xmlel{name = <<"inactive">>,
+			    attrs = [{<<"xmlns">>, ?NS_CLIENT_STATE}]}},
+		    StateData) ->
+    fsm_next_state(session_established, StateData#state{csi_state = inactive});
 session_established({xmlstreamelement, El},
 		    StateData) ->
     FromJID = StateData#state.jid,
@@ -1855,6 +1873,8 @@ send_element(StateData, El) when StateData#state.xml_socket ->
 send_element(StateData, El) ->
     send_text(StateData, xml:element_to_binary(El)).
 
+send_stanza(StateData, Stanza) when StateData#state.csi_state == inactive ->
+    csi_filter_stanza(StateData, Stanza);
 send_stanza(StateData, Stanza) when StateData#state.mgmt_state == pending ->
     mgmt_queue_add(StateData, Stanza);
 send_stanza(StateData, Stanza) when StateData#state.mgmt_state == active ->
@@ -1869,18 +1889,14 @@ send_stanza(StateData, Stanza) ->
     send_element(StateData, Stanza),
     StateData.
 
-send_packet(StateData, Packet) when StateData#state.mgmt_state == active;
-				    StateData#state.mgmt_state == pending ->
+send_packet(StateData, Packet) ->
     case is_stanza(Packet) of
       true ->
 	  send_stanza(StateData, Packet);
       false ->
 	  send_element(StateData, Packet),
 	  StateData
-    end;
-send_packet(StateData, Stanza) ->
-    send_element(StateData, Stanza),
-    StateData.
+    end.
 
 send_header(StateData, Server, Version, Lang)
     when StateData#state.xml_socket ->
@@ -2762,9 +2778,11 @@ handle_resume(StateData, Attrs) ->
 		       #xmlel{name = <<"r">>,
 			      attrs = [{<<"xmlns">>, AttrXmlns}],
 			      children = []}),
+	  FlushedState = csi_queue_flush(NewState),
+	  NewStateData = FlushedState#state{csi_state = active},
 	  ?INFO_MSG("Resumed session for ~s",
-		    [jlib:jid_to_string(NewState#state.jid)]),
-	  {ok, NewState};
+		    [jlib:jid_to_string(NewStateData#state.jid)]),
+	  {ok, NewStateData};
       {error, El, Msg} ->
 	  send_element(StateData, El),
 	  ?INFO_MSG("Cannot resume session for ~s@~s: ~s",
@@ -2953,6 +2971,8 @@ inherit_session_state(#state{user = U, server = S} = StateData, ResumeID) ->
 					   pres_invis = OldStateData#state.pres_invis,
 					   privacy_list = OldStateData#state.privacy_list,
 					   aux_fields = OldStateData#state.aux_fields,
+					   csi_state = OldStateData#state.csi_state,
+					   csi_queue = OldStateData#state.csi_queue,
 					   mgmt_xmlns = OldStateData#state.mgmt_xmlns,
 					   mgmt_queue = OldStateData#state.mgmt_queue,
 					   mgmt_timeout = OldStateData#state.mgmt_timeout,
@@ -2977,6 +2997,71 @@ make_resume_id(StateData) ->
     jlib:term_to_base64({StateData#state.resource, Time}).
 
 %%%----------------------------------------------------------------------
+%%% XEP-0352
+%%%----------------------------------------------------------------------
+
+csi_filter_stanza(#state{csi_state = CsiState, jid = JID} = StateData,
+		  Stanza) ->
+    Action = ejabberd_hooks:run_fold(csi_filter_stanza,
+				     StateData#state.server,
+				     send, [Stanza]),
+    ?DEBUG("Going to ~p stanza for inactive client ~p",
+	   [Action, jlib:jid_to_string(JID)]),
+    case Action of
+      queue -> csi_queue_add(StateData, Stanza);
+      drop -> StateData;
+      send ->
+	  From = xml:get_tag_attr_s(<<"from">>, Stanza),
+	  StateData1 = csi_queue_send(StateData, From),
+	  StateData2 = send_stanza(StateData1#state{csi_state = active},
+				   Stanza),
+	  StateData2#state{csi_state = CsiState}
+    end.
+
+csi_queue_add(#state{csi_queue = Queue, server = Host} = StateData,
+	      #xmlel{children = Els} = Stanza) ->
+    From = xml:get_tag_attr_s(<<"from">>, Stanza),
+    Time = calendar:now_to_universal_time(os:timestamp()),
+    DelayTag = [jlib:timestamp_to_xml(Time, utc,
+				      jlib:make_jid(<<"">>, Host, <<"">>),
+				      <<"Client Inactive">>)],
+    NewStanza = Stanza#xmlel{children = Els ++ DelayTag},
+    case length(StateData#state.csi_queue) >= csi_max_queue(StateData) of
+      true -> csi_queue_add(csi_queue_flush(StateData), NewStanza);
+      false ->
+	  NewQueue = lists:keystore(From, 1, Queue, {From, NewStanza}),
+	  StateData#state{csi_queue = NewQueue}
+    end.
+
+csi_queue_send(#state{csi_queue = Queue, csi_state = CsiState} = StateData,
+		From) ->
+    case lists:keytake(From, 1, Queue) of
+      {value, {From, Stanza}, NewQueue} ->
+	  NewStateData = send_stanza(StateData#state{csi_state = active},
+				     Stanza),
+	  NewStateData#state{csi_queue = NewQueue, csi_state = CsiState};
+      false -> StateData
+    end.
+
+csi_queue_flush(#state{csi_queue = Queue, csi_state = CsiState, jid = JID} =
+		StateData) ->
+    ?DEBUG("Flushing CSI queue for ~s", [jlib:jid_to_string(JID)]),
+    NewStateData =
+	lists:foldl(fun({_From, Stanza}, AccState) ->
+			  send_stanza(AccState, Stanza)
+		    end, StateData#state{csi_state = active}, Queue),
+    NewStateData#state{csi_queue = [], csi_state = CsiState}.
+
+%% Make sure we won't push too many messages to the XEP-0198 queue when the
+%% client becomes 'active' again.  Otherwise, the client might not manage to
+%% acknowledge the message flood in time.  Also, don't let the queue grow to
+%% more than 100 stanzas.
+csi_max_queue(#state{mgmt_max_queue = infinity}) -> 100;
+csi_max_queue(#state{mgmt_max_queue = Max}) when Max > 200 -> 100;
+csi_max_queue(#state{mgmt_max_queue = Max}) when Max < 2 -> 1;
+csi_max_queue(#state{mgmt_max_queue = Max}) -> Max div 2.
+
+%%%----------------------------------------------------------------------
 %%% JID Set memory footprint reduction code
 %%%----------------------------------------------------------------------
 
diff --git a/src/mod_client_state.erl b/src/mod_client_state.erl
new file mode 100644
index 000000000..83363162d
--- /dev/null
+++ b/src/mod_client_state.erl
@@ -0,0 +1,91 @@
+%%%----------------------------------------------------------------------
+%%% File    : mod_client_state.erl
+%%% Author  : Holger Weiss
+%%% Purpose : Filter stanzas sent to inactive clients (XEP-0352)
+%%% Created : 11 Sep 2014 by Holger Weiss
+%%%
+%%%
+%%% ejabberd, Copyright (C) 2014   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_client_state).
+-author('holger@zedat.fu-berlin.de').
+
+-behavior(gen_mod).
+
+-export([start/2, stop/1, filter_presence/2, filter_chat_states/2]).
+
+-include("ejabberd.hrl").
+-include("logger.hrl").
+-include("jlib.hrl").
+
+start(Host, Opts) ->
+    QueuePresence = gen_mod:get_opt(queue_presence, Opts,
+				    fun(true) -> true end, false),
+    DropChatStates = gen_mod:get_opt(drop_chat_states, Opts,
+				     fun(true) -> true end, false),
+    if QueuePresence ->
+	   ejabberd_hooks:add(csi_filter_stanza, Host, ?MODULE,
+			      filter_presence, 50);
+       true -> ok
+    end,
+    if DropChatStates ->
+	   ejabberd_hooks:add(csi_filter_stanza, Host, ?MODULE,
+			      filter_chat_states, 50);
+       true -> ok
+    end,
+    ok.
+
+stop(Host) ->
+    ejabberd_hooks:delete(csi_filter_stanza, Host, ?MODULE,
+			  filter_presence, 50),
+    ejabberd_hooks:delete(csi_filter_stanza, Host, ?MODULE,
+			  filter_chat_states, 50),
+    ok.
+
+filter_presence(_Action, #xmlel{name = <<"presence">>, attrs = Attrs}) ->
+    case xml:get_attr(<<"type">>, Attrs) of
+      {value, Type} when Type /= <<"unavailable">> ->
+	  ?DEBUG("Got important presence stanza", []),
+	  {stop, send};
+      _ ->
+	  ?DEBUG("Got availability presence stanza", []),
+	  {stop, queue}
+    end;
+filter_presence(Action, _Stanza) -> Action.
+
+filter_chat_states(_Action, #xmlel{name = <<"message">>} = Stanza) ->
+    %% All XEP-0085 chat states except for <gone/>:
+    ChatStates = [<<"active">>, <<"inactive">>, <<"composing">>, <<"paused">>],
+    Stripped =
+	lists:foldl(fun(ChatState, AccStanza) ->
+			    xml:remove_subtags(AccStanza, ChatState,
+					       {<<"xmlns">>, ?NS_CHATSTATES})
+		    end, Stanza, ChatStates),
+    case Stripped of
+      #xmlel{children = [#xmlel{name = <<"thread">>}]} ->
+	  ?DEBUG("Got standalone chat state notification", []),
+	  {stop, drop};
+      #xmlel{children = []} ->
+	  ?DEBUG("Got standalone chat state notification", []),
+	  {stop, drop};
+      _ ->
+	  ?DEBUG("Got message with chat state notification", []),
+	  {stop, send}
+    end;
+filter_chat_states(Action, _Stanza) -> Action.
diff --git a/test/ejabberd_SUITE.erl b/test/ejabberd_SUITE.erl
index fbf2444b6..0cc5afec3 100644
--- a/test/ejabberd_SUITE.erl
+++ b/test/ejabberd_SUITE.erl
@@ -237,6 +237,8 @@ db_tests(mnesia) ->
       [offline_master, offline_slave]},
      {test_carbons, [parallel],
       [carbons_master, carbons_slave]},
+     {test_client_state, [parallel],
+      [client_state_master, client_state_slave]},
      {test_muc, [parallel],
       [muc_master, muc_slave]},
      {test_announce, [sequence],
@@ -1505,6 +1507,42 @@ carbons_slave(Config) ->
     #presence{from = Peer, type = unavailable} = recv(),
     disconnect(Config).
 
+client_state_master(Config) ->
+    Peer = ?config(slave, Config),
+    Presence = #presence{to = Peer},
+    Message = #message{to = Peer, thread = <<"1">>,
+		       sub_els = [#chatstate_active{}]},
+    wait_for_slave(Config),
+    %% Should be queued (but see below):
+    send(Config, Presence),
+    %% Should be sent immediately, together with the previous presence:
+    send(Config, Message#message{body = [#text{data = <<"body">>}]}),
+    %% Should be dropped:
+    send(Config, Message),
+    %% Should be queued (but see below):
+    send(Config, Presence),
+    %% Should replace the previous presence in the queue:
+    send(Config, Presence#presence{type = unavailable}),
+    wait_for_slave(Config),
+    %% Should be sent immediately, as the client is active again.
+    send(Config, Message),
+    disconnect(Config).
+
+client_state_slave(Config) ->
+    true = ?config(csi, Config),
+    Peer = ?config(master, Config),
+    send(Config, #csi_inactive{}),
+    wait_for_master(Config),
+    #presence{from = Peer, sub_els = [#delay{}]} = recv(),
+    #message{from = Peer, thread = <<"1">>, sub_els = [#chatstate_active{}],
+	     body = [#text{data = <<"body">>}]} = recv(),
+    wait_for_master(Config),
+    send(Config, #csi_active{}),
+    ?recv2(#presence{from = Peer, type = unavailable, sub_els = [#delay{}]},
+	   #message{from = Peer, thread = <<"1">>,
+		    sub_els = [#chatstate_active{}]}),
+    disconnect(Config).
+
 %%%===================================================================
 %%% Aux functions
 %%%===================================================================
diff --git a/test/ejabberd_SUITE_data/ejabberd.yml b/test/ejabberd_SUITE_data/ejabberd.yml
index f096fc53f..597ba5be7 100644
--- a/test/ejabberd_SUITE_data/ejabberd.yml
+++ b/test/ejabberd_SUITE_data/ejabberd.yml
@@ -143,6 +143,9 @@ Welcome to this XMPP server."
         db_type: internal
       mod_carboncopy:
         db_type: internal
+      mod_client_state:
+        drop_chat_states: true
+        queue_presence: true
       mod_adhoc: []
       mod_configure: []
       mod_disco: []
diff --git a/test/suite.erl b/test/suite.erl
index a1043526f..a50bb64df 100644
--- a/test/suite.erl
+++ b/test/suite.erl
@@ -155,6 +155,8 @@ wait_auth_SASL_result(Config) ->
 	    lists:foldl(
 	      fun(#feature_sm{}, ConfigAcc) ->
 		      set_opt(sm, true, ConfigAcc);
+		 (#feature_csi{}, ConfigAcc) ->
+		      set_opt(csi, true, ConfigAcc);
 		 (_, ConfigAcc) ->
 		      ConfigAcc
 	      end, Config, Fs);
diff --git a/tools/xmpp_codec.erl b/tools/xmpp_codec.erl
index 2b9372973..d106fa8f4 100644
--- a/tools/xmpp_codec.erl
+++ b/tools/xmpp_codec.erl
@@ -47,6 +47,14 @@ decode({xmlel, _name, _attrs, _} = _el, Opts) ->
 	  decode_feature_sm(<<"urn:xmpp:sm:2">>, IgnoreEls, _el);
       {<<"sm">>, <<"urn:xmpp:sm:3">>} ->
 	  decode_feature_sm(<<"urn:xmpp:sm:3">>, IgnoreEls, _el);
+      {<<"inactive">>, <<"urn:xmpp:csi:0">>} ->
+	  decode_csi_inactive(<<"urn:xmpp:csi:0">>, IgnoreEls,
+			      _el);
+      {<<"active">>, <<"urn:xmpp:csi:0">>} ->
+	  decode_csi_active(<<"urn:xmpp:csi:0">>, IgnoreEls, _el);
+      {<<"csi">>, <<"urn:xmpp:csi:0">>} ->
+	  decode_feature_csi(<<"urn:xmpp:csi:0">>, IgnoreEls,
+			     _el);
       {<<"sent">>, <<"urn:xmpp:carbons:2">>} ->
 	  decode_carbons_sent(<<"urn:xmpp:carbons:2">>, IgnoreEls,
 			      _el);
@@ -163,6 +171,26 @@ decode({xmlel, _name, _attrs, _} = _el, Opts) ->
 			      _el);
       {<<"delay">>, <<"urn:xmpp:delay">>} ->
 	  decode_delay(<<"urn:xmpp:delay">>, IgnoreEls, _el);
+      {<<"paused">>,
+       <<"http://jabber.org/protocol/chatstates">>} ->
+	  decode_chatstate_paused(<<"http://jabber.org/protocol/chatstates">>,
+				  IgnoreEls, _el);
+      {<<"inactive">>,
+       <<"http://jabber.org/protocol/chatstates">>} ->
+	  decode_chatstate_inactive(<<"http://jabber.org/protocol/chatstates">>,
+				    IgnoreEls, _el);
+      {<<"gone">>,
+       <<"http://jabber.org/protocol/chatstates">>} ->
+	  decode_chatstate_gone(<<"http://jabber.org/protocol/chatstates">>,
+				IgnoreEls, _el);
+      {<<"composing">>,
+       <<"http://jabber.org/protocol/chatstates">>} ->
+	  decode_chatstate_composing(<<"http://jabber.org/protocol/chatstates">>,
+				     IgnoreEls, _el);
+      {<<"active">>,
+       <<"http://jabber.org/protocol/chatstates">>} ->
+	  decode_chatstate_active(<<"http://jabber.org/protocol/chatstates">>,
+				  IgnoreEls, _el);
       {<<"headers">>,
        <<"http://jabber.org/protocol/shim">>} ->
 	  decode_shim_headers(<<"http://jabber.org/protocol/shim">>,
@@ -998,6 +1026,9 @@ is_known_tag({xmlel, _name, _attrs, _} = _el) ->
       {<<"enable">>, <<"urn:xmpp:sm:3">>} -> true;
       {<<"sm">>, <<"urn:xmpp:sm:2">>} -> true;
       {<<"sm">>, <<"urn:xmpp:sm:3">>} -> true;
+      {<<"inactive">>, <<"urn:xmpp:csi:0">>} -> true;
+      {<<"active">>, <<"urn:xmpp:csi:0">>} -> true;
+      {<<"csi">>, <<"urn:xmpp:csi:0">>} -> true;
       {<<"sent">>, <<"urn:xmpp:carbons:2">>} -> true;
       {<<"received">>, <<"urn:xmpp:carbons:2">>} -> true;
       {<<"private">>, <<"urn:xmpp:carbons:2">>} -> true;
@@ -1074,6 +1105,21 @@ is_known_tag({xmlel, _name, _attrs, _} = _el) ->
 	  true;
       {<<"x">>, <<"jabber:x:delay">>} -> true;
       {<<"delay">>, <<"urn:xmpp:delay">>} -> true;
+      {<<"paused">>,
+       <<"http://jabber.org/protocol/chatstates">>} ->
+	  true;
+      {<<"inactive">>,
+       <<"http://jabber.org/protocol/chatstates">>} ->
+	  true;
+      {<<"gone">>,
+       <<"http://jabber.org/protocol/chatstates">>} ->
+	  true;
+      {<<"composing">>,
+       <<"http://jabber.org/protocol/chatstates">>} ->
+	  true;
+      {<<"active">>,
+       <<"http://jabber.org/protocol/chatstates">>} ->
+	  true;
       {<<"headers">>,
        <<"http://jabber.org/protocol/shim">>} ->
 	  true;
@@ -1856,6 +1902,26 @@ encode({pubsub, _, _, _, _, _, _, _, _} = Pubsub) ->
 encode({shim, _} = Headers) ->
     encode_shim_headers(Headers,
 			[{<<"xmlns">>, <<"http://jabber.org/protocol/shim">>}]);
+encode({chatstate_active} = Active) ->
+    encode_chatstate_active(Active,
+			    [{<<"xmlns">>,
+			      <<"http://jabber.org/protocol/chatstates">>}]);
+encode({chatstate_composing} = Composing) ->
+    encode_chatstate_composing(Composing,
+			       [{<<"xmlns">>,
+				 <<"http://jabber.org/protocol/chatstates">>}]);
+encode({chatstate_gone} = Gone) ->
+    encode_chatstate_gone(Gone,
+			  [{<<"xmlns">>,
+			    <<"http://jabber.org/protocol/chatstates">>}]);
+encode({chatstate_inactive} = Inactive) ->
+    encode_chatstate_inactive(Inactive,
+			      [{<<"xmlns">>,
+				<<"http://jabber.org/protocol/chatstates">>}]);
+encode({chatstate_paused} = Paused) ->
+    encode_chatstate_paused(Paused,
+			    [{<<"xmlns">>,
+			      <<"http://jabber.org/protocol/chatstates">>}]);
 encode({delay, _, _} = Delay) ->
     encode_delay(Delay,
 		 [{<<"xmlns">>, <<"urn:xmpp:delay">>}]);
@@ -1926,6 +1992,14 @@ encode({carbons_received, _} = Received) ->
 encode({carbons_sent, _} = Sent) ->
     encode_carbons_sent(Sent,
 			[{<<"xmlns">>, <<"urn:xmpp:carbons:2">>}]);
+encode({feature_csi, _} = Csi) ->
+    encode_feature_csi(Csi, []);
+encode({csi_active} = Active) ->
+    encode_csi_active(Active,
+		      [{<<"xmlns">>, <<"urn:xmpp:csi:0">>}]);
+encode({csi_inactive} = Inactive) ->
+    encode_csi_inactive(Inactive,
+			[{<<"xmlns">>, <<"urn:xmpp:csi:0">>}]);
 encode({feature_sm, _} = Sm) ->
     encode_feature_sm(Sm, []);
 encode({sm_enable, _, _, _} = Enable) ->
@@ -2084,6 +2158,16 @@ get_ns({pubsub, _, _, _, _, _, _, _, _}) ->
     <<"http://jabber.org/protocol/pubsub">>;
 get_ns({shim, _}) ->
     <<"http://jabber.org/protocol/shim">>;
+get_ns({chatstate_active}) ->
+    <<"http://jabber.org/protocol/chatstates">>;
+get_ns({chatstate_composing}) ->
+    <<"http://jabber.org/protocol/chatstates">>;
+get_ns({chatstate_gone}) ->
+    <<"http://jabber.org/protocol/chatstates">>;
+get_ns({chatstate_inactive}) ->
+    <<"http://jabber.org/protocol/chatstates">>;
+get_ns({chatstate_paused}) ->
+    <<"http://jabber.org/protocol/chatstates">>;
 get_ns({delay, _, _}) -> <<"urn:xmpp:delay">>;
 get_ns({legacy_delay, _, _}) -> <<"jabber:x:delay">>;
 get_ns({streamhost, _, _, _}) ->
@@ -2115,6 +2199,9 @@ get_ns({carbons_private}) -> <<"urn:xmpp:carbons:2">>;
 get_ns({carbons_received, _}) ->
     <<"urn:xmpp:carbons:2">>;
 get_ns({carbons_sent, _}) -> <<"urn:xmpp:carbons:2">>;
+get_ns({feature_csi, _}) -> <<"urn:xmpp:csi:0">>;
+get_ns({csi_active}) -> <<"urn:xmpp:csi:0">>;
+get_ns({csi_inactive}) -> <<"urn:xmpp:csi:0">>;
 get_ns(_) -> <<>>.
 
 dec_int(Val) -> dec_int(Val, infinity, infinity).
@@ -2272,6 +2359,11 @@ pp(pubsub, 8) ->
     [subscriptions, affiliations, publish, subscribe,
      unsubscribe, options, items, retract];
 pp(shim, 1) -> [headers];
+pp(chatstate_active, 0) -> [];
+pp(chatstate_composing, 0) -> [];
+pp(chatstate_gone, 0) -> [];
+pp(chatstate_inactive, 0) -> [];
+pp(chatstate_paused, 0) -> [];
 pp(delay, 2) -> [stamp, from];
 pp(legacy_delay, 2) -> [stamp, from];
 pp(streamhost, 3) -> [jid, host, port];
@@ -2298,6 +2390,9 @@ pp(carbons_enable, 0) -> [];
 pp(carbons_private, 0) -> [];
 pp(carbons_received, 1) -> [forwarded];
 pp(carbons_sent, 1) -> [forwarded];
+pp(feature_csi, 1) -> [xmlns];
+pp(csi_active, 0) -> [];
+pp(csi_inactive, 0) -> [];
 pp(feature_sm, 1) -> [xmlns];
 pp(sm_enable, 3) -> [max, resume, xmlns];
 pp(sm_enabled, 5) -> [id, location, max, resume, xmlns];
@@ -3268,6 +3363,54 @@ encode_feature_sm_attr_xmlns(undefined, _acc) -> _acc;
 encode_feature_sm_attr_xmlns(_val, _acc) ->
     [{<<"xmlns">>, _val} | _acc].
 
+decode_csi_inactive(__TopXMLNS, __IgnoreEls,
+		    {xmlel, <<"inactive">>, _attrs, _els}) ->
+    {csi_inactive}.
+
+encode_csi_inactive({csi_inactive}, _xmlns_attrs) ->
+    _els = [],
+    _attrs = _xmlns_attrs,
+    {xmlel, <<"inactive">>, _attrs, _els}.
+
+decode_csi_active(__TopXMLNS, __IgnoreEls,
+		  {xmlel, <<"active">>, _attrs, _els}) ->
+    {csi_active}.
+
+encode_csi_active({csi_active}, _xmlns_attrs) ->
+    _els = [],
+    _attrs = _xmlns_attrs,
+    {xmlel, <<"active">>, _attrs, _els}.
+
+decode_feature_csi(__TopXMLNS, __IgnoreEls,
+		   {xmlel, <<"csi">>, _attrs, _els}) ->
+    Xmlns = decode_feature_csi_attrs(__TopXMLNS, _attrs,
+				     undefined),
+    {feature_csi, Xmlns}.
+
+decode_feature_csi_attrs(__TopXMLNS,
+			 [{<<"xmlns">>, _val} | _attrs], _Xmlns) ->
+    decode_feature_csi_attrs(__TopXMLNS, _attrs, _val);
+decode_feature_csi_attrs(__TopXMLNS, [_ | _attrs],
+			 Xmlns) ->
+    decode_feature_csi_attrs(__TopXMLNS, _attrs, Xmlns);
+decode_feature_csi_attrs(__TopXMLNS, [], Xmlns) ->
+    decode_feature_csi_attr_xmlns(__TopXMLNS, Xmlns).
+
+encode_feature_csi({feature_csi, Xmlns},
+		   _xmlns_attrs) ->
+    _els = [],
+    _attrs = encode_feature_csi_attr_xmlns(Xmlns,
+					   _xmlns_attrs),
+    {xmlel, <<"csi">>, _attrs, _els}.
+
+decode_feature_csi_attr_xmlns(__TopXMLNS, undefined) ->
+    undefined;
+decode_feature_csi_attr_xmlns(__TopXMLNS, _val) -> _val.
+
+encode_feature_csi_attr_xmlns(undefined, _acc) -> _acc;
+encode_feature_csi_attr_xmlns(_val, _acc) ->
+    [{<<"xmlns">>, _val} | _acc].
+
 decode_carbons_sent(__TopXMLNS, __IgnoreEls,
 		    {xmlel, <<"sent">>, _attrs, _els}) ->
     Forwarded = decode_carbons_sent_els(__TopXMLNS,
@@ -5355,6 +5498,55 @@ encode_delay_attr_from(undefined, _acc) -> _acc;
 encode_delay_attr_from(_val, _acc) ->
     [{<<"from">>, enc_jid(_val)} | _acc].
 
+decode_chatstate_paused(__TopXMLNS, __IgnoreEls,
+			{xmlel, <<"paused">>, _attrs, _els}) ->
+    {chatstate_paused}.
+
+encode_chatstate_paused({chatstate_paused},
+			_xmlns_attrs) ->
+    _els = [],
+    _attrs = _xmlns_attrs,
+    {xmlel, <<"paused">>, _attrs, _els}.
+
+decode_chatstate_inactive(__TopXMLNS, __IgnoreEls,
+			  {xmlel, <<"inactive">>, _attrs, _els}) ->
+    {chatstate_inactive}.
+
+encode_chatstate_inactive({chatstate_inactive},
+			  _xmlns_attrs) ->
+    _els = [],
+    _attrs = _xmlns_attrs,
+    {xmlel, <<"inactive">>, _attrs, _els}.
+
+decode_chatstate_gone(__TopXMLNS, __IgnoreEls,
+		      {xmlel, <<"gone">>, _attrs, _els}) ->
+    {chatstate_gone}.
+
+encode_chatstate_gone({chatstate_gone}, _xmlns_attrs) ->
+    _els = [],
+    _attrs = _xmlns_attrs,
+    {xmlel, <<"gone">>, _attrs, _els}.
+
+decode_chatstate_composing(__TopXMLNS, __IgnoreEls,
+			   {xmlel, <<"composing">>, _attrs, _els}) ->
+    {chatstate_composing}.
+
+encode_chatstate_composing({chatstate_composing},
+			   _xmlns_attrs) ->
+    _els = [],
+    _attrs = _xmlns_attrs,
+    {xmlel, <<"composing">>, _attrs, _els}.
+
+decode_chatstate_active(__TopXMLNS, __IgnoreEls,
+			{xmlel, <<"active">>, _attrs, _els}) ->
+    {chatstate_active}.
+
+encode_chatstate_active({chatstate_active},
+			_xmlns_attrs) ->
+    _els = [],
+    _attrs = _xmlns_attrs,
+    {xmlel, <<"active">>, _attrs, _els}.
+
 decode_shim_headers(__TopXMLNS, __IgnoreEls,
 		    {xmlel, <<"headers">>, _attrs, _els}) ->
     Headers = decode_shim_headers_els(__TopXMLNS,
diff --git a/tools/xmpp_codec.hrl b/tools/xmpp_codec.hrl
index 549c6fb1b..6e142414f 100644
--- a/tools/xmpp_codec.hrl
+++ b/tools/xmpp_codec.hrl
@@ -8,6 +8,8 @@
 -record(text, {lang :: binary(),
                data :: binary()}).
 
+-record(chatstate_paused, {}).
+
 -record(streamhost, {jid :: any(),
                      host :: binary(),
                      port = 1080 :: non_neg_integer()}).
@@ -24,6 +26,8 @@
                              jid :: any(),
                              subid :: binary()}).
 
+-record(csi_inactive, {}).
+
 -record(ping, {}).
 
 -record(delay, {stamp :: any(),
@@ -57,6 +61,8 @@
                     resume = false :: any(),
                     xmlns :: binary()}).
 
+-record(chatstate_gone, {}).
+
 -record(starttls_failure, {}).
 
 -record(sasl_challenge, {text :: any()}).
@@ -123,14 +129,20 @@
 
 -record(sasl_response, {text :: any()}).
 
+-record(chatstate_inactive, {}).
+
 -record(pubsub_subscribe, {node :: binary(),
                            jid :: any()}).
 
+-record(chatstate_composing, {}).
+
 -record(sasl_auth, {mechanism :: binary(),
                     text :: any()}).
 
 -record(p1_push, {}).
 
+-record(feature_csi, {xmlns :: binary()}).
+
 -record(legacy_delay, {stamp :: binary(),
                        from :: any()}).
 
@@ -220,6 +232,8 @@
 
 -record(block_list, {}).
 
+-record(csi_active, {}).
+
 -record(xdata_field, {label :: binary(),
                       type :: 'boolean' | 'fixed' | 'hidden' | 'jid-multi' | 'jid-single' | 'list-multi' | 'list-single' | 'text-multi' | 'text-private' | 'text-single',
                       var :: binary(),
@@ -255,6 +269,8 @@
                       mode = tcp :: 'tcp' | 'udp',
                       sid :: binary()}).
 
+-record(chatstate_active, {}).
+
 -record(vcard_org, {name :: binary(),
                     units = [] :: [binary()]}).
 
@@ -475,114 +491,122 @@
 -record(time, {tzo :: any(),
                utc :: any()}).
 
--type xmpp_element() :: #session{} |
-                        #compression{} |
-                        #pubsub_subscription{} |
-                        #version{} |
-                        #pubsub_affiliation{} |
-                        #muc_admin{} |
-                        #sm_a{} |
-                        #carbons_sent{} |
-                        #p1_rebind{} |
-                        #sasl_abort{} |
-                        #carbons_received{} |
-                        #pubsub_retract{} |
-                        #compressed{} |
-                        #block_list{} |
-                        #'see-other-host'{} |
-                        #starttls_proceed{} |
-                        #sm_resumed{} |
-                        #forwarded{} |
-                        #privacy_list{} |
-                        #text{} |
-                        #vcard_org{} |
-                        #feature_sm{} |
-                        #pubsub_item{} |
-                        #roster_item{} |
-                        #pubsub_event_item{} |
-                        #muc_item{} |
-                        #shim{} |
-                        #caps{} |
-                        #muc{} |
-                        #stream_features{} |
-                        #stats{} |
-                        #pubsub_items{} |
-                        #pubsub_event_items{} |
-                        #disco_items{} |
-                        #pubsub_options{} |
-                        #starttls{} |
-                        #sasl_mechanisms{} |
-                        #sasl_success{} |
-                        #compress{} |
-                        #bytestreams{} |
-                        #vcard_key{} |
-                        #identity{} |
-                        #legacy_delay{} |
-                        #muc_user_destroy{} |
-                        #muc_owner_destroy{} |
-                        #privacy{} |
-                        #delay{} |
-                        #muc_history{} |
-                        #bookmark_url{} |
-                        #vcard_email{} |
-                        #vcard_label{} |
-                        #vcard_tel{} |
-                        #disco_info{} |
-                        #vcard_logo{} |
-                        #vcard_geo{} |
-                        #vcard_photo{} |
-                        #muc_owner{} |
-                        #pubsub{} |
-                        #sm_r{} |
-                        #muc_actor{} |
-                        #error{} |
-                        #stream_error{} |
-                        #feature_register{} |
-                        #roster{} |
-                        #muc_user{} |
-                        #vcard_adr{} |
-                        #register{} |
-                        #muc_invite{} |
-                        #carbons_disable{} |
-                        #bookmark_conference{} |
-                        #time{} |
-                        #sasl_response{} |
-                        #pubsub_subscribe{} |
-                        #presence{} |
-                        #message{} |
-                        #sm_enable{} |
-                        #starttls_failure{} |
-                        #sasl_challenge{} |
-                        #gone{} |
-                        #private{} |
-                        #compress_failure{} |
-                        #sasl_failure{} |
-                        #bookmark_storage{} |
-                        #vcard_name{} |
-                        #sm_resume{} |
-                        #carbons_enable{} |
-                        #carbons_private{} |
-                        #pubsub_unsubscribe{} |
-                        #muc_decline{} |
-                        #sasl_auth{} |
-                        #p1_push{} |
-                        #pubsub_publish{} |
-                        #unblock{} |
-                        #p1_ack{} |
-                        #block{} |
-                        #xdata{} |
-                        #iq{} |
-                        #last{} |
-                        #redirect{} |
-                        #sm_enabled{} |
-                        #pubsub_event{} |
-                        #vcard_sound{} |
-                        #streamhost{} |
-                        #stat{} |
-                        #xdata_field{} |
-                        #bind{} |
-                        #sm_failed{} |
-                        #vcard{} |
-                        #ping{} |
-                        #disco_item{} |
-                        #privacy_item{}.
+-type xmpp_codec_type() :: #session{} |
+                           #compression{} |
+                           #pubsub_subscription{} |
+                           #version{} |
+                           #pubsub_affiliation{} |
+                           #muc_admin{} |
+                           #sm_a{} |
+                           #carbons_sent{} |
+                           #p1_rebind{} |
+                           #sasl_abort{} |
+                           #carbons_received{} |
+                           #pubsub_retract{} |
+                           #compressed{} |
+                           #block_list{} |
+                           #'see-other-host'{} |
+                           #starttls_proceed{} |
+                           #sm_resumed{} |
+                           #forwarded{} |
+                           #privacy_list{} |
+                           #text{} |
+                           #vcard_org{} |
+                           #feature_sm{} |
+                           #pubsub_item{} |
+                           #roster_item{} |
+                           #pubsub_event_item{} |
+                           #muc_item{} |
+                           #shim{} |
+                           #pubsub_event_items{} |
+                           #disco_items{} |
+                           #pubsub_options{} |
+                           #sasl_success{} |
+                           #compress{} |
+                           #bytestreams{} |
+                           #vcard_key{} |
+                           #identity{} |
+                           #feature_csi{} |
+                           #legacy_delay{} |
+                           #muc_user_destroy{} |
+                           #muc_owner_destroy{} |
+                           #privacy{} |
+                           #delay{} |
+                           #muc_history{} |
+                           #bookmark_url{} |
+                           #vcard_email{} |
+                           #vcard_label{} |
+                           #vcard_tel{} |
+                           #vcard_logo{} |
+                           #disco_info{} |
+                           #vcard_geo{} |
+                           #vcard_photo{} |
+                           #muc_owner{} |
+                           #pubsub{} |
+                           #sm_r{} |
+                           #muc_actor{} |
+                           #error{} |
+                           #stream_error{} |
+                           #feature_register{} |
+                           #roster{} |
+                           #muc_user{} |
+                           #vcard_adr{} |
+                           #register{} |
+                           #csi_active{} |
+                           #muc_invite{} |
+                           #carbons_disable{} |
+                           #chatstate_active{} |
+                           #bookmark_conference{} |
+                           #time{} |
+                           #sasl_response{} |
+                           #chatstate_inactive{} |
+                           #pubsub_subscribe{} |
+                           #presence{} |
+                           #message{} |
+                           #sm_enable{} |
+                           #chatstate_gone{} |
+                           #starttls_failure{} |
+                           #sasl_challenge{} |
+                           #gone{} |
+                           #private{} |
+                           #compress_failure{} |
+                           #sasl_failure{} |
+                           #bookmark_storage{} |
+                           #vcard_name{} |
+                           #sm_resume{} |
+                           #carbons_enable{} |
+                           #carbons_private{} |
+                           #pubsub_unsubscribe{} |
+                           #csi_inactive{} |
+                           #muc_decline{} |
+                           #sasl_auth{} |
+                           #p1_push{} |
+                           #pubsub_publish{} |
+                           #unblock{} |
+                           #p1_ack{} |
+                           #block{} |
+                           #xdata{} |
+                           #iq{} |
+                           #last{} |
+                           #redirect{} |
+                           #sm_enabled{} |
+                           #pubsub_event{} |
+                           #vcard_sound{} |
+                           #chatstate_paused{} |
+                           #streamhost{} |
+                           #stat{} |
+                           #xdata_field{} |
+                           #bind{} |
+                           #sm_failed{} |
+                           #vcard{} |
+                           #chatstate_composing{} |
+                           #ping{} |
+                           #disco_item{} |
+                           #privacy_item{} |
+                           #caps{} |
+                           #muc{} |
+                           #stream_features{} |
+                           #stats{} |
+                           #pubsub_items{} |
+                           #starttls{} |
+                           #sasl_mechanisms{}.
diff --git a/tools/xmpp_codec.spec b/tools/xmpp_codec.spec
index 4d218839b..c5d9013ed 100644
--- a/tools/xmpp_codec.spec
+++ b/tools/xmpp_codec.spec
@@ -1757,6 +1757,31 @@
            result = {shim, '$headers'},
            refs = [#ref{name = shim_header, label = '$headers'}]}).
 
+-xml(chatstate_active,
+     #elem{name = <<"active">>,
+           xmlns = <<"http://jabber.org/protocol/chatstates">>,
+           result = {chatstate_active}}).
+
+-xml(chatstate_composing,
+     #elem{name = <<"composing">>,
+           xmlns = <<"http://jabber.org/protocol/chatstates">>,
+           result = {chatstate_composing}}).
+
+-xml(chatstate_gone,
+     #elem{name = <<"gone">>,
+           xmlns = <<"http://jabber.org/protocol/chatstates">>,
+           result = {chatstate_gone}}).
+
+-xml(chatstate_inactive,
+     #elem{name = <<"inactive">>,
+           xmlns = <<"http://jabber.org/protocol/chatstates">>,
+           result = {chatstate_inactive}}).
+
+-xml(chatstate_paused,
+     #elem{name = <<"paused">>,
+           xmlns = <<"http://jabber.org/protocol/chatstates">>,
+           result = {chatstate_paused}}).
+
 -xml(delay,
      #elem{name = <<"delay">>,
            xmlns = <<"urn:xmpp:delay">>,
@@ -2070,6 +2095,22 @@
 	   refs = [#ref{name = forwarded, min = 1,
                         max = 1, label = '$forwarded'}]}).
 
+-xml(feature_csi,
+     #elem{name = <<"csi">>,
+	   xmlns = <<"urn:xmpp:csi:0">>,
+	   result = {feature_csi, '$xmlns'},
+	   attrs = [#attr{name = <<"xmlns">>}]}).
+
+-xml(csi_active,
+     #elem{name = <<"active">>,
+	   xmlns = <<"urn:xmpp:csi:0">>,
+	   result = {csi_active}}).
+
+-xml(csi_inactive,
+     #elem{name = <<"inactive">>,
+	   xmlns = <<"urn:xmpp:csi:0">>,
+	   result = {csi_inactive}}).
+
 -xml(feature_sm,
      #elem{name = <<"sm">>,
 	   xmlns = [<<"urn:xmpp:sm:2">>, <<"urn:xmpp:sm:3">>],