xmpp.chapril.org-ejabberd/src/ejabberd_service.erl

%%%-------------------------------------------------------------------
%%% Created : 11 Dec 2016 by Evgeny Khramtsov <ekhramtsov@process-one.net>
%%%
%%%
%%% 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(ejabberd_service).
-behaviour(xmpp_stream_in).
-behaviour(ejabberd_config).
-behaviour(ejabberd_socket).

-protocol({xep, 114, '1.6'}).

%% ejabberd_socket callbacks
-export([start/2, start_link/2, socket_type/0]).
%% ejabberd_config callbacks
-export([opt_type/1, transform_listen_option/2]).
%% xmpp_stream_in callbacks
-export([init/1, handle_info/2, terminate/2, code_change/3]).
-export([handle_stream_start/2, handle_auth_success/4, handle_auth_failure/4,
	 handle_authenticated_packet/2, get_password_fun/1]).
%% API
-export([send/2]).

-include("ejabberd.hrl").
-include("xmpp.hrl").
-include("logger.hrl").

-type state() :: map().
-export_type([state/0]).

%%%===================================================================
%%% API
%%%===================================================================
start(SockData, Opts) ->
    xmpp_stream_in:start(?MODULE, [SockData, Opts],
			 ejabberd_config:fsm_limit_opts(Opts)).

start_link(SockData, Opts) ->
    xmpp_stream_in:start_link(?MODULE, [SockData, Opts],
			      ejabberd_config:fsm_limit_opts(Opts)).

socket_type() ->
    xml_stream.

-spec send(pid(), xmpp_element()) -> ok;
	  (state(), xmpp_element()) -> state().
send(Stream, Pkt) ->
    xmpp_stream_in:send(Stream, Pkt).

%%%===================================================================
%%% xmpp_stream_in callbacks
%%%===================================================================
init([State, Opts]) ->
    Access = gen_mod:get_opt(access, Opts, fun acl:access_rules_validator/1, all),
    Shaper = gen_mod:get_opt(shaper_rule, Opts, fun acl:shaper_rules_validator/1, none),
    HostOpts = case lists:keyfind(hosts, 1, Opts) of
		   {hosts, HOpts} ->
		       lists:foldl(
			 fun({H, Os}, D) ->
				 P = proplists:get_value(
				       password, Os,
				       p1_sha:sha(randoms:bytes(20))),
				 dict:store(H, P, D)
			 end, dict:new(), HOpts);
		   false ->
		       Pass = proplists:get_value(
				password, Opts,
				p1_sha:sha(randoms:bytes(20))),
		       dict:from_list([{global, Pass}])
	       end,
    CheckFrom = gen_mod:get_opt(check_from, Opts,
				fun(Flag) when is_boolean(Flag) -> Flag end,
				true),
    xmpp_stream_in:change_shaper(State, Shaper),
    State1 = State#{access => Access,
		    xmlns => ?NS_COMPONENT,
		    lang => ?MYLANG,
		    server => ?MYNAME,
		    host_opts => HostOpts,
		    check_from => CheckFrom},
    ejabberd_hooks:run_fold(component_init, {ok, State1}, [Opts]).

handle_stream_start(_StreamStart,
		    #{remote_server := RemoteServer,
		      lang := Lang,
		      host_opts := HostOpts} = State) ->
    case ejabberd_router:is_my_host(RemoteServer) of
	true ->
	    Txt = <<"Unable to register route on existing local domain">>,
	    xmpp_stream_in:send(State, xmpp:serr_conflict(Txt, Lang));
	false ->
	    NewHostOpts = case dict:is_key(RemoteServer, HostOpts) of
			      true ->
				  HostOpts;
			      false ->
				  case dict:find(global, HostOpts) of
				      {ok, GlobalPass} ->
					  dict:from_list([{RemoteServer, GlobalPass}]);
				      error ->
					  HostOpts
				  end
			  end,
	    State#{host_opts => NewHostOpts}
    end.

get_password_fun(#{remote_server := RemoteServer,
		   socket := Socket, sockmod := SockMod,
		   ip := IP,
		   host_opts := HostOpts}) ->
    fun(_) ->
	    case dict:find(RemoteServer, HostOpts) of
		{ok, Password} ->
		    {Password, undefined};
		error ->
		    ?ERROR_MSG("(~s) Domain ~s is unconfigured for "
			       "external component from ~s",
			       [SockMod:pp(Socket), RemoteServer,
				ejabberd_config:may_hide_data(jlib:ip_to_list(IP))]),
		    {false, undefined}
	    end
    end.

handle_auth_success(_, Mech, _,
		    #{remote_server := RemoteServer, host_opts := HostOpts,
		      socket := Socket, sockmod := SockMod,
		      ip := IP} = State) ->
    ?INFO_MSG("(~s) Accepted external component ~s authentication "
	      "for ~s from ~s",
	      [SockMod:pp(Socket), Mech, RemoteServer,
	       ejabberd_config:may_hide_data(jlib:ip_to_list(IP))]),
    lists:foreach(
      fun (H) ->
	      ejabberd_router:register_route(H, ?MYNAME),
	      ejabberd_hooks:run(component_connected, [H])
      end, dict:fetch_keys(HostOpts)),
    State.

handle_auth_failure(_, Mech, Reason,
		    #{remote_server := RemoteServer,
		      sockmod := SockMod,
		      socket := Socket, ip := IP} = State) ->
    ?ERROR_MSG("(~s) Failed external component ~s authentication "
	       "for ~s from ~s: ~s",
	       [SockMod:pp(Socket), Mech, RemoteServer,
		ejabberd_config:may_hide_data(jlib:ip_to_list(IP)),
		Reason]),
    State.

handle_authenticated_packet(Pkt, #{lang := Lang} = State) ->
    From = xmpp:get_from(Pkt),
    case check_from(From, State) of
	true ->
	    To = xmpp:get_to(Pkt),
	    ejabberd_router:route(From, To, Pkt),
	    State;
	false ->
	    Txt = <<"Improper domain part of 'from' attribute">>,
	    Err = xmpp:serr_invalid_from(Txt, Lang),
	    xmpp_stream_in:send(State, Err)
    end.

handle_info({route, From, To, Packet}, #{access := Access} = State) ->
    case acl:match_rule(global, Access, From) of
	allow ->
	    Pkt = xmpp:set_from_to(Packet, From, To),
	    xmpp_stream_in:send(State, Pkt);
	deny ->
	    Lang = xmpp:get_lang(Packet),
	    Err = xmpp:err_not_allowed(<<"Denied by ACL">>, Lang),
	    ejabberd_router:route_error(To, From, Packet, Err),
	    State
    end;
handle_info(Info, State) ->
    ?ERROR_MSG("Unexpected info: ~p", [Info]),
    State.

terminate(Reason, #{stream_state := StreamState, host_opts := HostOpts}) ->
    case StreamState of
	established ->
	    lists:foreach(
	      fun(H) ->
		      ejabberd_router:unregister_route(H),
		      ejabberd_hooks:run(component_disconnected, [H, Reason])
	      end, dict:fetch_keys(HostOpts));
	_ ->
	    ok
    end.

code_change(_OldVsn, State, _Extra) ->
    {ok, State}.

%%%===================================================================
%%% Internal functions
%%%===================================================================
-spec check_from(jid(), state()) -> boolean().
check_from(_From, #{check_from := false}) ->
    %% If the admin does not want to check the from field
    %% when accept packets from any address.
    %% In this case, the component can send packet of
    %% behalf of the server users.
    true;
check_from(From, #{host_opts := HostOpts}) ->
    %% The default is the standard behaviour in XEP-0114
    Server = From#jid.lserver,
    dict:is_key(Server, HostOpts).

transform_listen_option({hosts, Hosts, O}, Opts) ->
    case lists:keyfind(hosts, 1, Opts) of
        {_, PrevHostOpts} ->
            NewHostOpts =
                lists:foldl(
                  fun(H, Acc) ->
                          dict:append_list(H, O, Acc)
                  end, dict:from_list(PrevHostOpts), Hosts),
            [{hosts, dict:to_list(NewHostOpts)}|
             lists:keydelete(hosts, 1, Opts)];
        _ ->
            [{hosts, [{H, O} || H <- Hosts]}|Opts]
    end;
transform_listen_option({host, Host, Os}, Opts) ->
    transform_listen_option({hosts, [Host], Os}, Opts);
transform_listen_option(Opt, Opts) ->
    [Opt|Opts].

opt_type(_) -> [].