%%%----------------------------------------------------------------------
%%% File : mod_proxy65_stream.erl
%%% Author : Evgeniy Khramtsov <xram@jabber.ru>
%%% Purpose : Bytestream process.
%%% Created : 12 Oct 2006 by Evgeniy Khramtsov <xram@jabber.ru>
%%%
%%% ejabberd, Copyright (C) 2002-2022 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_proxy65_stream).
-author('xram@jabber.ru').
-behaviour(p1_fsm).
-behaviour(ejabberd_listener).
%% gen_fsm callbacks.
-export([init/1, handle_event/3, handle_sync_event/4,
code_change/4, handle_info/3, terminate/3]).
%% gen_fsm states.
-export([accepting/2, wait_for_init/2, wait_for_auth/2,
wait_for_request/2, wait_for_activation/2,
stream_established/2]).
-export([start/3, stop/1, start_link/3, activate/2,
relay/3, accept/1, listen_options/0]).
-include("mod_proxy65.hrl").
-include("logger.hrl").
-define(WAIT_TIMEOUT, 60000).
-record(state,
{socket :: inet:socket(),
timer = make_ref() :: reference(),
sha1 = <<"">> :: binary(),
host = <<"">> :: binary(),
auth_type = anonymous :: plain | anonymous,
shaper = none :: ejabberd_shaper:shaper()}).
%% Unused callbacks
handle_event(_Event, StateName, StateData) ->
{next_state, StateName, StateData}.
code_change(_OldVsn, StateName, StateData, _Extra) ->
{ok, StateName, StateData}.
%%-------------------------------
start(gen_tcp, Socket, Opts) ->
Host = proplists:get_value(server_host, Opts),
p1_fsm:start(?MODULE, [Socket, Host], []).
start_link(gen_tcp, Socket, Opts) ->
Host = proplists:get_value(server_host, Opts),
p1_fsm:start_link(?MODULE, [Socket, Host], []).
init([Socket, Host]) ->
process_flag(trap_exit, true),
AuthType = mod_proxy65_opt:auth_type(Host),
Shaper = mod_proxy65_opt:shaper(Host),
RecvBuf = mod_proxy65_opt:recbuf(Host),
SendBuf = mod_proxy65_opt:sndbuf(Host),
TRef = erlang:send_after(?WAIT_TIMEOUT, self(), stop),
inet:setopts(Socket, [{recbuf, RecvBuf}, {sndbuf, SendBuf}]),
{ok, accepting,
#state{host = Host, auth_type = AuthType,
socket = Socket, shaper = Shaper, timer = TRef}}.
terminate(_Reason, StateName, #state{sha1 = SHA1}) ->
Mod = gen_mod:ram_db_mod(global, mod_proxy65),
Mod:unregister_stream(SHA1),
if StateName == stream_established ->
?INFO_MSG("(~w) Bytestream terminated", [self()]);
true -> ok
end.
%%%------------------------------
%%% API.
%%%------------------------------
accept(StreamPid) ->
p1_fsm:send_event(StreamPid, accept).
stop(StreamPid) -> StreamPid ! stop.
activate({P1, J1}, {P2, J2}) ->
case catch {p1_fsm:sync_send_all_state_event(P1,
get_socket),
p1_fsm:sync_send_all_state_event(P2, get_socket)}
of
{S1, S2} when is_port(S1), is_port(S2) ->
P1 ! {activate, P2, S2, J1, J2},
P2 ! {activate, P1, S1, J1, J2},
JID1 = jid:encode(J1),
JID2 = jid:encode(J2),
?INFO_MSG("(~w:~w) Activated bytestream for ~ts "
"-> ~ts",
[P1, P2, JID1, JID2]),
ok;
_ -> error
end.
%%%-----------------------
%%% States
%%%-----------------------
accepting(accept, State) ->
inet:setopts(State#state.socket, [{active, true}]),
{next_state, wait_for_init, State}.
wait_for_init(Packet,
#state{socket = Socket, auth_type = AuthType} =
StateData) ->
case mod_proxy65_lib:unpack_init_message(Packet) of
{ok, AuthMethods} ->
Method = select_auth_method(AuthType, AuthMethods),
gen_tcp:send(Socket,
mod_proxy65_lib:make_init_reply(Method)),
case Method of
?AUTH_ANONYMOUS ->
{next_state, wait_for_request, StateData};
?AUTH_PLAIN -> {next_state, wait_for_auth, StateData};
?AUTH_NO_METHODS -> {stop, normal, StateData}
end;
error -> {stop, normal, StateData}
end.
wait_for_auth(Packet,
#state{socket = Socket, host = Host} = StateData) ->
case mod_proxy65_lib:unpack_auth_request(Packet) of
{User, Pass} ->
Result = ejabberd_auth:check_password(User, <<"">>, Host, Pass),
gen_tcp:send(Socket,
mod_proxy65_lib:make_auth_reply(Result)),
case Result of
true -> {next_state, wait_for_request, StateData};
false -> {stop, normal, StateData}
end;
_ -> {stop, normal, StateData}
end.
wait_for_request(Packet,
#state{socket = Socket} = StateData) ->
Request = mod_proxy65_lib:unpack_request(Packet),
case Request of
#s5_request{sha1 = SHA1, cmd = connect} ->
Mod = gen_mod:ram_db_mod(global, mod_proxy65),
case Mod:register_stream(SHA1, self()) of
ok ->
inet:setopts(Socket, [{active, false}]),
gen_tcp:send(Socket,
mod_proxy65_lib:make_reply(Request)),
{next_state, wait_for_activation,
StateData#state{sha1 = SHA1}};
_ ->
Err = mod_proxy65_lib:make_error_reply(Request),
gen_tcp:send(Socket, Err),
{stop, normal, StateData}
end;
#s5_request{cmd = udp} ->
Err = mod_proxy65_lib:make_error_reply(Request,
?ERR_COMMAND_NOT_SUPPORTED),
gen_tcp:send(Socket, Err),
{stop, normal, StateData};
_ -> {stop, normal, StateData}
end.
wait_for_activation(_Data, StateData) ->
{next_state, wait_for_activation, StateData}.
stream_established(_Data, StateData) ->
{next_state, stream_established, StateData}.
%%%-----------------------
%%% Callbacks processing
%%%-----------------------
%% SOCKS5 packets.
handle_info({tcp, _S, Data}, StateName, StateData)
when StateName /= wait_for_activation ->
misc:cancel_timer(StateData#state.timer),
TRef = erlang:send_after(?WAIT_TIMEOUT, self(), stop),
p1_fsm:send_event(self(), Data),
{next_state, StateName, StateData#state{timer = TRef}};
%% Activation message.
handle_info({activate, PeerPid, PeerSocket, IJid, TJid},
wait_for_activation, StateData) ->
erlang:monitor(process, PeerPid),
misc:cancel_timer(StateData#state.timer),
MySocket = StateData#state.socket,
Shaper = StateData#state.shaper,
Host = StateData#state.host,
MaxRate = find_maxrate(Shaper, IJid, TJid, Host),
spawn_link(?MODULE, relay,
[MySocket, PeerSocket, MaxRate]),
{next_state, stream_established, StateData};
%% Socket closed
handle_info({tcp_closed, _Socket}, _StateName,
StateData) ->
{stop, normal, StateData};
handle_info({tcp_error, _Socket, _Reason}, _StateName,
StateData) ->
{stop, normal, StateData};
%% Got stop message.
handle_info(stop, _StateName, StateData) ->
{stop, normal, StateData};
%% Either linked process or peer process died.
handle_info({'EXIT', _, _}, _StateName, StateData) ->
{stop, normal, StateData};
handle_info({'DOWN', _, _, _, _}, _StateName,
StateData) ->
{stop, normal, StateData};
%% Packets of no interest
handle_info(_Info, StateName, StateData) ->
{next_state, StateName, StateData}.
%% Socket request.
handle_sync_event(get_socket, _From,
wait_for_activation, StateData) ->
Socket = StateData#state.socket,
{reply, Socket, wait_for_activation, StateData};
handle_sync_event(_Event, _From, StateName,
StateData) ->
{reply, error, StateName, StateData}.
%%%-------------------------------------------------
%%% Relay Process.
%%%-------------------------------------------------
relay(MySocket, PeerSocket, Shaper) ->
case gen_tcp:recv(MySocket, 0) of
{ok, Data} ->
case gen_tcp:send(PeerSocket, Data) of
ok ->
{NewShaper, Pause} = ejabberd_shaper:update(Shaper, byte_size(Data)),
if Pause > 0 -> timer:sleep(Pause);
true -> pass
end,
relay(MySocket, PeerSocket, NewShaper);
{error, _} = Err ->
Err
end;
{error, _} = Err ->
Err
end.
%%%------------------------
%%% Auxiliary functions
%%%------------------------
select_auth_method(plain, AuthMethods) ->
case lists:member(?AUTH_PLAIN, AuthMethods) of
true -> ?AUTH_PLAIN;
false -> ?AUTH_NO_METHODS
end;
select_auth_method(anonymous, AuthMethods) ->
case lists:member(?AUTH_ANONYMOUS, AuthMethods) of
true -> ?AUTH_ANONYMOUS;
false -> ?AUTH_NO_METHODS
end.
%% Obviously, we must use shaper with maximum rate.
find_maxrate(Shaper, JID1, JID2, Host) ->
R1 = ejabberd_shaper:match(Host, Shaper, JID1),
R2 = ejabberd_shaper:match(Host, Shaper, JID2),
R = case ejabberd_shaper:get_max_rate(R1) >= ejabberd_shaper:get_max_rate(R2) of
true -> R1;
false -> R2
end,
ejabberd_shaper:new(R).
listen_options() ->
[].
