New hook: muc_filter_presence

Add a hook that allows for modifying or dropping presence stanzas sent
to MUC rooms.

diff --git a/src/mod_muc_room.erl b/src/mod_muc_room.erl
index df06bce4f825e1964230b62802967dc32ed3bc49..495852d5a3042f8dc0262fd19f3cf3de38e405cb 100644 (file)
--- a/src/mod_muc_room.erl
+++ b/src/mod_muc_room.erl
@@ -1035,117 +1035,125 @@ get_participant_data(From, StateData) ->
     end.
 
 process_presence(From, Nick,
-                #xmlel{name = <<"presence">>, attrs = Attrs} = Packet,
+                #xmlel{name = <<"presence">>, attrs = Attrs0} = Packet0,
                 StateData) ->
-    Type = xml:get_attr_s(<<"type">>, Attrs),
-    Lang = xml:get_attr_s(<<"xml:lang">>, Attrs),
-    StateData1 = case Type of
-                  <<"unavailable">> ->
-                      case is_user_online(From, StateData) of
-                        true ->
-                            NewPacket = case
-                                          {(StateData#state.config)#config.allow_visitor_status,
-                                           is_visitor(From, StateData)}
-                                            of
-                                          {false, true} ->
-                                              strip_status(Packet);
-                                          _ -> Packet
-                                        end,
-                            NewState = add_user_presence_un(From, NewPacket,
-                                                            StateData),
-                            case (?DICT):find(Nick, StateData#state.nicks) of
-                              {ok, [_, _ | _]} -> ok;
-                              _ -> send_new_presence(From, NewState)
-                            end,
-                            Reason = case xml:get_subtag(NewPacket,
-                                                         <<"status">>)
-                                         of
-                                       false -> <<"">>;
-                                       Status_el ->
-                                           xml:get_tag_cdata(Status_el)
-                                     end,
-                            remove_online_user(From, NewState, Reason);
-                        _ -> StateData
-                      end;
-                  <<"error">> ->
-                      case is_user_online(From, StateData) of
-                        true ->
-                            ErrorText =
-                                <<"This participant is kicked from the "
-                                  "room because he sent an error presence">>,
-                            expulse_participant(Packet, From, StateData,
-                                                translate:translate(Lang,
-                                                                    ErrorText));
-                        _ -> StateData
-                      end;
-                  <<"">> ->
-                      case is_user_online(From, StateData) of
-                        true ->
-                            case is_nick_change(From, Nick, StateData) of
-                              true ->
-                                  case {nick_collision(From, Nick, StateData),
-                                        mod_muc:can_use_nick(StateData#state.server_host,
-                                                             StateData#state.host,
-                                                             From, Nick),
-                                        {(StateData#state.config)#config.allow_visitor_nickchange,
-                                         is_visitor(From, StateData)}}
-                                      of
-                                    {_, _, {false, true}} ->
-                                        ErrText =
-                                            <<"Visitors are not allowed to change their "
-                                              "nicknames in this room">>,
-                                        Err = jlib:make_error_reply(Packet,
-                                                                    ?ERRT_NOT_ALLOWED(Lang,
-                                                                                      ErrText)),
-                                        ejabberd_router:route(jlib:jid_replace_resource(StateData#state.jid,
-                                                                               Nick),
-                                                     From, Err),
-                                        StateData;
-                                    {true, _, _} ->
-                                        Lang = xml:get_attr_s(<<"xml:lang">>,
-                                                              Attrs),
-                                        ErrText =
-                                            <<"That nickname is already in use by another "
-                                              "occupant">>,
-                                        Err = jlib:make_error_reply(Packet,
-                                                                    ?ERRT_CONFLICT(Lang,
-                                                                                   ErrText)),
-                                        ejabberd_router:route(jlib:jid_replace_resource(StateData#state.jid,
-                                                                               Nick), % TODO: s/Nick/""/
-                                                     From, Err),
-                                        StateData;
-                                    {_, false, _} ->
-                                        ErrText =
-                                            <<"That nickname is registered by another "
-                                              "person">>,
-                                        Err = jlib:make_error_reply(Packet,
-                                                                    ?ERRT_CONFLICT(Lang,
-                                                                                   ErrText)),
-                                        ejabberd_router:route(jlib:jid_replace_resource(StateData#state.jid,
-                                                                               Nick),
-                                                     From, Err),
-                                        StateData;
-                                    _ -> change_nick(From, Nick, StateData)
-                                  end;
-                              _NotNickChange ->
-                                  Stanza = case
-                                             {(StateData#state.config)#config.allow_visitor_status,
-                                              is_visitor(From, StateData)}
-                                               of
-                                             {false, true} ->
-                                                 strip_status(Packet);
-                                             _Allowed -> Packet
-                                           end,
-                                  NewState = add_user_presence(From, Stanza,
-                                                               StateData),
-                                  send_new_presence(From, NewState),
-                                  NewState
-                            end;
-                        _ -> add_new_user(From, Nick, Packet, StateData)
-                      end;
-                  _ -> StateData
-                end,
-    close_room_if_temporary_and_empty(StateData1).
+    Type0 = xml:get_attr_s(<<"type">>, Attrs0),
+    IsOnline = is_user_online(From, StateData),
+    if Type0 == <<"">>;
+       IsOnline and ((Type0 == <<"unavailable">>) or (Type0 == <<"error">>)) ->
+          case ejabberd_hooks:run_fold(muc_filter_presence,
+                                       StateData#state.server_host,
+                                       Packet0,
+                                       [StateData,
+                                        StateData#state.jid,
+                                        From, Nick]) of
+            drop ->
+                {next_state, normal_state, StateData};
+            #xmlel{attrs = Attrs} = Packet ->
+                Type = xml:get_attr_s(<<"xml:lang">>, Attrs),
+                Lang = xml:get_attr_s(<<"xml:lang">>, Attrs),
+                StateData1 = case Type of
+                               <<"unavailable">> ->
+                                   NewPacket = case
+                                                 {(StateData#state.config)#config.allow_visitor_status,
+                                                  is_visitor(From, StateData)}
+                                                   of
+                                                 {false, true} ->
+                                                     strip_status(Packet);
+                                                 _ -> Packet
+                                               end,
+                                   NewState = add_user_presence_un(From, NewPacket,
+                                                                   StateData),
+                                   case (?DICT):find(Nick, StateData#state.nicks) of
+                                     {ok, [_, _ | _]} -> ok;
+                                     _ -> send_new_presence(From, NewState)
+                                   end,
+                                   Reason = case xml:get_subtag(NewPacket,
+                                                                <<"status">>)
+                                                of
+                                              false -> <<"">>;
+                                              Status_el ->
+                                                  xml:get_tag_cdata(Status_el)
+                                            end,
+                                   remove_online_user(From, NewState, Reason);
+                               <<"error">> ->
+                                   ErrorText =
+                                       <<"This participant is kicked from the "
+                                         "room because he sent an error presence">>,
+                                   expulse_participant(Packet, From, StateData,
+                                                       translate:translate(Lang,
+                                                                           ErrorText));
+                               <<"">> ->
+                                   if not IsOnline ->
+                                          add_new_user(From, Nick, Packet, StateData);
+                                      true ->
+                                          case is_nick_change(From, Nick, StateData) of
+                                            true ->
+                                                case {nick_collision(From, Nick, StateData),
+                                                      mod_muc:can_use_nick(StateData#state.server_host,
+                                                                           StateData#state.host,
+                                                                           From, Nick),
+                                                      {(StateData#state.config)#config.allow_visitor_nickchange,
+                                                       is_visitor(From, StateData)}}
+                                                    of
+                                                  {_, _, {false, true}} ->
+                                                      ErrText =
+                                                          <<"Visitors are not allowed to change their "
+                                                            "nicknames in this room">>,
+                                                      Err = jlib:make_error_reply(Packet,
+                                                                                  ?ERRT_NOT_ALLOWED(Lang,
+                                                                                                    ErrText)),
+                                                      ejabberd_router:route(jlib:jid_replace_resource(StateData#state.jid,
+                                                                                             Nick),
+                                                                   From, Err),
+                                                      StateData;
+                                                  {true, _, _} ->
+                                                      Lang = xml:get_attr_s(<<"xml:lang">>,
+                                                                            Attrs),
+                                                      ErrText =
+                                                          <<"That nickname is already in use by another "
+                                                            "occupant">>,
+                                                      Err = jlib:make_error_reply(Packet,
+                                                                                  ?ERRT_CONFLICT(Lang,
+                                                                                                 ErrText)),
+                                                      ejabberd_router:route(jlib:jid_replace_resource(StateData#state.jid,
+                                                                                             Nick), % TODO: s/Nick/""/
+                                                                   From, Err),
+                                                      StateData;
+                                                  {_, false, _} ->
+                                                      ErrText =
+                                                          <<"That nickname is registered by another "
+                                                            "person">>,
+                                                      Err = jlib:make_error_reply(Packet,
+                                                                                  ?ERRT_CONFLICT(Lang,
+                                                                                                 ErrText)),
+                                                      ejabberd_router:route(jlib:jid_replace_resource(StateData#state.jid,
+                                                                                             Nick),
+                                                                  From, Err),
+                                                      StateData;
+                                                  _ -> change_nick(From, Nick, StateData)
+                                                end;
+                                            _NotNickChange ->
+                                                Stanza = case
+                                                           {(StateData#state.config)#config.allow_visitor_status,
+                                                            is_visitor(From, StateData)}
+                                                             of
+                                                           {false, true} ->
+                                                               strip_status(Packet);
+                                                           _Allowed -> Packet
+                                                         end,
+                                                NewState = add_user_presence(From, Stanza,
+                                                                             StateData),
+                                                send_new_presence(From, NewState),
+                                                NewState
+                                          end
+                                   end
+                             end,
+                close_room_if_temporary_and_empty(StateData1)
+          end;
+       true ->
+          {next_state, normal_state, StateData}
+    end.
 
 close_room_if_temporary_and_empty(StateData1) ->
     case not (StateData1#state.config)#config.persistent