%%%----------------------------------------------------------------------
%%% File : mod_echo.erl
%%% Author : Alexey Shchepin <alexey@process-one.net>
%%% Purpose : Simple ejabberd module.
%%% Created : 15 Jan 2003 by Alexey Shchepin <alexey@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2013 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., 59 Temple Place, Suite 330, Boston, MA
%%% 02111-1307 USA
%%%
%%%----------------------------------------------------------------------
-module(mod_echo).
-author('alexey@process-one.net').
-behaviour(gen_server).
-behaviour(gen_mod).
%% API
-export([start_link/2, start/2, stop/1,
do_client_version/3]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2,
handle_info/2, terminate/2, code_change/3]).
-include("ejabberd.hrl").
-include("logger.hrl").
-include("jlib.hrl").
-record(state, {host = <<"">> :: binary()}).
-define(PROCNAME, ejabberd_mod_echo).
%%====================================================================
%% API
%%====================================================================
%%--------------------------------------------------------------------
%% Function: start_link() -> {ok,Pid} | ignore | {error,Error}
%% Description: Starts the server
%%--------------------------------------------------------------------
start_link(Host, Opts) ->
Proc = gen_mod:get_module_proc(Host, ?PROCNAME),
gen_server:start_link({local, Proc}, ?MODULE,
[Host, Opts], []).
start(Host, Opts) ->
Proc = gen_mod:get_module_proc(Host, ?PROCNAME),
ChildSpec = {Proc, {?MODULE, start_link, [Host, Opts]},
temporary, 1000, worker, [?MODULE]},
supervisor:start_child(ejabberd_sup, ChildSpec).
stop(Host) ->
Proc = gen_mod:get_module_proc(Host, ?PROCNAME),
gen_server:call(Proc, stop),
supervisor:terminate_child(ejabberd_sup, Proc),
supervisor:delete_child(ejabberd_sup, Proc).
%%====================================================================
%% gen_server callbacks
%%====================================================================
%%--------------------------------------------------------------------
%% Function: init(Args) -> {ok, State} |
%% {ok, State, Timeout} |
%% ignore |
%% {stop, Reason}
%% Description: Initiates the server
%%--------------------------------------------------------------------
init([Host, Opts]) ->
MyHost = gen_mod:get_opt_host(Host, Opts,
<<"echo.@HOST@">>),
ejabberd_router:register_route(MyHost),
{ok, #state{host = MyHost}}.
%%--------------------------------------------------------------------
%% Function: %% handle_call(Request, From, State) -> {reply, Reply, State} |
%% {reply, Reply, State, Timeout} |
%% {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, Reply, State} |
%% {stop, Reason, State}
%% Description: Handling call messages
%%--------------------------------------------------------------------
handle_call(stop, _From, State) ->
{stop, normal, ok, State}.
%%--------------------------------------------------------------------
%% Function: handle_cast(Msg, State) -> {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State}
%% Description: Handling cast messages
%%--------------------------------------------------------------------
handle_cast(_Msg, State) -> {noreply, State}.
%%--------------------------------------------------------------------
%% Function: handle_info(Info, State) -> {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State}
%% Description: Handling all non call/cast messages
%%--------------------------------------------------------------------
handle_info({route, From, To, Packet}, State) ->
Packet2 = case From#jid.user of
<<"">> ->
jlib:make_error_reply(Packet, ?ERR_BAD_REQUEST);
_ -> Packet
end,
do_client_version(disabled, To, From),
ejabberd_router:route(To, From, Packet2),
{noreply, State};
handle_info(_Info, State) -> {noreply, State}.
%%--------------------------------------------------------------------
%% Function: terminate(Reason, State) -> void()
%% Description: This function is called by a gen_server when it is about to
%% terminate. It should be the opposite of Module:init/1 and do any necessary
%% cleaning up. When it returns, the gen_server terminates with Reason.
%% The return value is ignored.
%%--------------------------------------------------------------------
terminate(_Reason, State) ->
ejabberd_router:unregister_route(State#state.host), ok.
%%--------------------------------------------------------------------
%% Func: code_change(OldVsn, State, Extra) -> {ok, NewState}
%% Description: Convert process state when code is changed
%%--------------------------------------------------------------------
code_change(_OldVsn, State, _Extra) -> {ok, State}.
%%--------------------------------------------------------------------
%% Example of routing XMPP packets using Erlang's message passing
%%--------------------------------------------------------------------
%% To enable this educational example, edit the function handle_info:
%% replace the argument 'disabled' with 'enabled' in the call to the
%% function do_client_version.
%% ejabberd provides a method to receive XMPP packets using Erlang's
%% message passing mechanism.
%%
%% The packets received by ejabberd are sent
%% to the local destination process by sending an Erlang message.
%% This means that you can receive XMPP stanzas in an Erlang process
%% using Erlang's Receive, as long as this process is registered in
%% ejabberd as the process which handles the destination JID.
%%
%% This example function is called when a client queries the echo service.
%% This function then sends a query to the client, and waits 5 seconds to
%% receive an answer. The answer will only be accepted if it was sent
%% using exactly the same JID. We add a (mostly) random resource to
%% try to guarantee that the received response matches the request sent.
%% Finally, the received response is printed in the ejabberd log file.
do_client_version(disabled, _From, _To) -> ok;
do_client_version(enabled, From, To) ->
ToS = jlib:jid_to_string(To),
Random_resource =
iolist_to_binary(integer_to_list(random:uniform(100000))),
From2 = From#jid{resource = Random_resource,
lresource = Random_resource},
Packet = #xmlel{name = <<"iq">>,
attrs = [{<<"to">>, ToS}, {<<"type">>, <<"get">>}],
children =
[#xmlel{name = <<"query">>,
attrs = [{<<"xmlns">>, ?NS_VERSION}],
children = []}]},
ejabberd_router:route(From2, To, Packet),
Els = receive
{route, To, From2, IQ} ->
#xmlel{name = <<"query">>, children = List} =
xml:get_subtag(IQ, <<"query">>),
List
after 5000 -> % Timeout in miliseconds: 5 seconds
[]
end,
Values = [{Name, Value}
|| #xmlel{name = Name, attrs = [],
children = [{xmlcdata, Value}]}
<- Els],
Values_string1 = [io_lib:format("~n~s: ~p", [N, V])
|| {N, V} <- Values],
Values_string2 = iolist_to_binary(Values_string1),
?INFO_MSG("Information of the client: ~s~s",
[ToS, Values_string2]).
