ejabberd_local用于注册发到服务器本身的IQ以及路由到本地的ejabberd_sm（message）

对外主要提供route，register_iq_handler，unregister_iq_response_handler方法

route(From, To, Packet) ->    case catch do_route(From, To, Packet) of      {
     'EXIT', Reason} ->      ?ERROR_MSG("~p~nwhen processing: ~p",             [Reason, {From, To, Packet}]);      _ -> ok    end.do_route(From, To, Packet) ->    ?DEBUG("local route~n\tfrom ~p~n\tto ~p~n\tpacket "       "~P~n",       [From, To, Packet, 8]),    if To#jid.luser /= <<"">> ->       ejabberd_sm:route(From, To, Packet);       To#jid.lresource == <<"">> ->       #xmlel{name = Name} = Packet,       case Name of         <<"iq">> -> process_iq(From, To, Packet);         <<"message">> -> ok;         <<"presence">> -> ok;         _ -> ok       end;       true ->       #xmlel{attrs = Attrs} = Packet,       case xml:get_attr_s(<<"type">>, Attrs) of         <<"error">> -> ok;         <<"result">> -> ok;         _ ->         ejabberd_hooks:run(local_send_to_resource_hook,                    To#jid.lserver, [From, To, Packet])       end    end.

route当是完整的message的信息的时候，通过ejabberd_sm:route路由信息

当是IQ信息的时候route:process_iq(From, To, Packet)处理，根据register_iq_handler注册的信息