% M3UA in accordance with RFC4666 (http://tools.ietf.org/html/rfc4666) % (C) 2011 by Harald Welte % % All Rights Reserved % % This program is free software; you can redistribute it and/or modify % it under the terms of the GNU Affero General Public License as % published by the Free Software Foundation; either version 3 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 Affero General Public License % along with this program. If not, see . % % Additional Permission under GNU AGPL version 3 section 7: % % If you modify this Program, or any covered work, by linking or % combining it with runtime libraries of Erlang/OTP as released by % Ericsson on http://www.erlang.org (or a modified version of these % libraries), containing parts covered by the terms of the Erlang Public % License (http://www.erlang.org/EPLICENSE), the licensors of this % Program grant you additional permission to convey the resulting work % without the need to license the runtime libraries of Erlang/OTP under % the GNU Affero General Public License. Corresponding Source for a % non-source form of such a combination shall include the source code % for the parts of the runtime libraries of Erlang/OTP used as well as % that of the covered work. -module(m3ua_core). -author('Harald Welte '). -behaviour(gen_fsm). -include_lib("kernel/include/inet_sctp.hrl"). -include("osmo_util.hrl"). -include("sccp.hrl"). -include("m3ua.hrl"). -export([start_link/1]). -export([init/1, terminate/3, code_change/4, handle_event/3, handle_info/3]). % FSM states: -export([asp_down/2, asp_inactive/2, asp_active/2]). -define(T_ACK_TIMEOUT, 2*60*100). % Loop Data -record(m3ua_state, { role, % asp | sgp asp_state, % down, inactive, active t_ack, user_fun, user_args, sctp_remote_ip, sctp_remote_port, sctp_sock, sctp_assoc_id }). start_link(InitOpts) -> gen_fsm:start_link(?MODULE, InitOpts, [{debug, [trace]}]). reconnect_sctp(L = #m3ua_state{sctp_remote_ip = Ip, sctp_remote_port = Port, sctp_sock = Sock}) -> timer:sleep(1*1000), io:format("SCTP Reconnect ~p:~p~n", [Ip, Port]), InitMsg = #sctp_initmsg{num_ostreams = 2, max_instreams = 2}, case gen_sctp:connect(Sock, Ip, Port, [{active, once}, {reuseaddr, true}, {sctp_initmsg, InitMsg}]) of {ok, Assoc} -> send_prim_to_user(L, osmo_util:make_prim('M','SCTP_ESTABLISH',confirm)), L#m3ua_state{sctp_assoc_id = Assoc#sctp_assoc_change.assoc_id}; {error, Error } -> io:format("SCTP Error ~p, reconnecting~n", [Error]), reconnect_sctp(L) end. build_openopt({sctp_local_port, Port}) -> {port, Port}; build_openopt({sctp_local_ip, undefined}) -> []; build_openopt({sctp_local_ip, Ip}) -> {ip, Ip}; build_openopt(_) -> []. build_openopts(PropList) -> [{active, once}, {reuseaddr, true}] ++ lists:flatten(lists:map(fun build_openopt/1, PropList)). init(InitOpts) -> {ok, SctpSock} = gen_sctp:open(build_openopts(InitOpts)), LoopDat = #m3ua_state{role = asp, sctp_sock = SctpSock, user_fun = proplists:get_value(user_fun, InitOpts), user_args = proplists:get_value(user_args, InitOpts), sctp_remote_ip = proplists:get_value(sctp_remote_ip, InitOpts), sctp_remote_port = proplists:get_value(sctp_remote_port, InitOpts)}, LoopDat2 = reconnect_sctp(LoopDat), {ok, asp_down, LoopDat2}. terminate(Reason, _State, LoopDat) -> io:format("Terminating ~p (Reason: ~p)~n", [?MODULE, Reason]), gen_sctp:close(LoopDat#m3ua_state.sctp_sock). code_change(_OldVsn, StateName, StateData, _Extra) -> {ok, StateName, StateData}. % Helper function to send data to the SCTP peer send_sctp_to_peer(LoopDat, PktData, StreamId) when is_binary(PktData) -> #m3ua_state{sctp_sock = Sock, sctp_assoc_id = Assoc} = LoopDat, SndRcvInfo = #sctp_sndrcvinfo{assoc_id = Assoc, ppid = 3, stream = StreamId}, gen_sctp:send(Sock, SndRcvInfo, PktData). % same as above, but for un-encoded #m3ua_msg{} send_sctp_to_peer(LoopDat, M3uaMsg) when is_record(M3uaMsg, m3ua_msg) -> MsgBin = m3ua_codec:encode_m3ua_msg(M3uaMsg), StreamId = sctp_stream_for_m3ua(M3uaMsg), send_sctp_to_peer(LoopDat, MsgBin, StreamId). % resolve the Stream ID depending on the m3ua_msg: 0 == management, 1 == trafic sctp_stream_for_m3ua(#m3ua_msg{msg_class = Class}) when Class == ?M3UA_MSGC_TRANSFER -> 1; sctp_stream_for_m3ua(#m3ua_msg{}) -> 0. send_prim_to_user(LoopDat, Prim) when is_record(LoopDat, m3ua_state), is_record(Prim, primitive) -> #m3ua_state{user_fun = Fun, user_args = Args} = LoopDat, Fun(Prim, Args). % helper to send one of the up/down/act/inact management messages + start timer send_msg_start_tack(LoopDat, State, MsgClass, MsgType, Params) -> % generate and send the respective message Msg = #m3ua_msg{version = 1, msg_class = MsgClass, msg_type = MsgType, payload = Params}, send_sctp_to_peer(LoopDat, Msg), % start T(ack) timer and wait for ASP_UP_ACK timer:cancel(LoopDat#m3ua_state.t_ack), {ok, Tack} = timer:apply_after(?T_ACK_TIMEOUT, gen_fsm, send_event, [self(), {timer_expired, t_ack, {MsgClass, MsgType, Params}}]), {next_state, State, LoopDat#m3ua_state{t_ack = Tack}}. handle_event(Event, State, LoopDat) -> io:format("Unknown Event ~p in state ~p~n", [Event, State]), {next_state, State, LoopDat}. handle_info({sctp, Socket, _RemoteIp, _RemotePort, {ANC, SAC}}, _State, LoopDat) when is_record(SAC, sctp_assoc_change) -> io:format("SCTP Assoc Change ~p ~p~n", [ANC, SAC]), #sctp_assoc_change{state = SacState, outbound_streams = _OutStreams, inbound_streams = _InStreams, assoc_id = _AssocId} = SAC, case SacState of comm_up -> % primmitive to the user send_prim_to_user(LoopDat, osmo_util:make_prim('M','SCTP_ESTABLISH',confirm)), LoopDat2 = LoopDat; comm_lost -> send_prim_to_user(LoopDat, osmo_util:make_prim('M','SCTP_RELEASE',indication)), LoopDat2 = reconnect_sctp(LoopDat); shutdown_comp -> send_prim_to_user(LoopDat, osmo_util:make_prim('M','SCTP_RELEASE',indication)), LoopDat2 = reconnect_sctp(LoopDat); addr_unreachable -> LoopDat2 = reconnect_sctp(LoopDat) end, inet:setopts(Socket, [{active, once}]), {next_state, asp_down, LoopDat2}; handle_info({sctp, Socket, _RemoteIp, _RemotePort, {ANC, SPC}}, State, LoopDat) when is_record(SPC, sctp_paddr_change) -> io:format("SCTP Peer address change ~p ~p~n", [ANC, SPC]), {NewState, LoopDat2} = case SPC#sctp_paddr_change.state of addr_available -> % we don't care {State, LoopDat}; addr_unreachable -> send_prim_to_user(LoopDat, osmo_util:make_prim('M','SCTP_RELEASE',indication)), {asp_down, reconnect_sctp(LoopDat)}; addr_removed -> % FIXME: what if the last one is removed {State, LoopDat}; addr_added -> % we don't care {State, LoopDat}; addr_made_prim -> % FIXME: do we need to change remote_ip in our LoopDat? {State, LoopDat} end, inet:setopts(Socket, [{active, once}]), {next_state, NewState, LoopDat2}; handle_info({sctp, Socket, RemoteIp, RemotePort, {[Anc], Data}}, State, LoopDat) -> io:format("SCTP rx data: ~p ~p~n", [Anc, Data]), % process incoming SCTP data if Socket == LoopDat#m3ua_state.sctp_sock, RemoteIp == LoopDat#m3ua_state.sctp_remote_ip, RemotePort == LoopDat#m3ua_state.sctp_remote_port, 3 == Anc#sctp_sndrcvinfo.ppid -> Ret = rx_sctp(Anc, Data, State, LoopDat); true -> io:format("unknown SCTP: ~p ~p~n", [Anc, Data]), Ret = {next_state, State, LoopDat} end, inet:setopts(Socket, [{active, once}]), Ret; handle_info({sctp, Socket, RemoteIp, RemotePort, {_Anc, Data}}, _State, LoopDat) when is_record(Data, sctp_shutdown_event) -> io:format("SCTP remote ~p:~p shutdown~n", [RemoteIp, RemotePort]), inet:setopts(Socket, [{active, once}]), {next_state, asp_down, LoopDat}. asp_down(#primitive{subsystem = 'M', gen_name = 'ASP_UP', spec_name = request, parameters = _Params}, LoopDat) -> % M-ASP_UP.req from user, generate message and send to remote peer send_msg_start_tack(LoopDat, asp_down, ?M3UA_MSGC_ASPSM, ?M3UA_MSGT_ASPSM_ASPUP, []); asp_down({timer_expired, t_ack, {?M3UA_MSGC_ASPSM, ?M3UA_MSGT_ASPSM_ASPUP, Params}}, LoopDat) -> send_msg_start_tack(LoopDat, asp_down, ?M3UA_MSGC_ASPSM, ?M3UA_MSGT_ASPSM_ASPUP, Params); asp_down(#m3ua_msg{msg_class = ?M3UA_MSGC_ASPSM, msg_type = ?M3UA_MSGT_ASPSM_ASPUP_ACK}, LoopDat) -> timer:cancel(LoopDat#m3ua_state.t_ack), % transition into ASP_INACTIVE send_prim_to_user(LoopDat, osmo_util:make_prim('M','ASP_UP',confirm)), {next_state, asp_inactive, LoopDat}; asp_down(M3uaMsg, LoopDat) when is_record(M3uaMsg, m3ua_msg) -> rx_m3ua(M3uaMsg, asp_down, LoopDat). asp_inactive(#primitive{subsystem = 'M', gen_name = 'ASP_ACTIVE', spec_name = request, parameters = _Params}, LoopDat) -> % M-ASP_ACTIVE.req from user, generate message and send to remote peer send_msg_start_tack(LoopDat, asp_inactive, ?M3UA_MSGC_ASPTM, ?M3UA_MSGT_ASPTM_ASPAC, [{?M3UA_IEI_TRAF_MODE_TYPE, <<0,0,0,1>>}]); asp_inactive({timer_expired, t_ack, {?M3UA_MSGC_ASPTM, ?M3UA_MSGT_ASPTM_ASPAC, Params}}, LoopDat) -> send_msg_start_tack(LoopDat, asp_inactive, ?M3UA_MSGC_ASPTM, ?M3UA_MSGT_ASPTM_ASPAC, Params); asp_inactive(#primitive{subsystem = 'M', gen_name = 'ASP_DOWN', spec_name = request, parameters = _Params}, LoopDat) -> % M-ASP_DOWN.req from user, generate message and send to remote peer send_msg_start_tack(LoopDat, asp_inactive, ?M3UA_MSGC_ASPSM, ?M3UA_MSGT_ASPSM_ASPDN, []); asp_inactive({timer_expired, t_ack, {?M3UA_MSGC_ASPSM, ?M3UA_MSGT_ASPSM_ASPDN, Params}}, LoopDat) -> send_msg_start_tack(LoopDat, asp_inactive, ?M3UA_MSGC_ASPSM, ?M3UA_MSGT_ASPSM_ASPDN, Params); asp_inactive(#m3ua_msg{msg_class = ?M3UA_MSGC_ASPTM, msg_type = ?M3UA_MSGT_ASPTM_ASPAC_ACK}, LoopDat) -> timer:cancel(LoopDat#m3ua_state.t_ack), % transition into ASP_ACTIVE % signal this to the user send_prim_to_user(LoopDat, osmo_util:make_prim('M','ASP_ACTIVE',confirm)), {next_state, asp_active, LoopDat}; asp_inactive(#m3ua_msg{msg_class = ?M3UA_MSGC_ASPSM, msg_type = ?M3UA_MSGT_ASPSM_ASPDN_ACK}, LoopDat) -> timer:cancel(LoopDat#m3ua_state.t_ack), % transition into ASP_DOWN % signal this to the user send_prim_to_user(LoopDat, osmo_util:make_prim('M','ASP_DOWN',confirm)), {next_state, asp_down, LoopDat}; asp_inactive(M3uaMsg, LoopDat) when is_record(M3uaMsg, m3ua_msg) -> rx_m3ua(M3uaMsg, asp_inactive, LoopDat). asp_active(#m3ua_msg{msg_class = ?M3UA_MSGC_ASPSM, msg_type = ?M3UA_MSGT_ASPSM_ASPDN_ACK}, LoopDat) -> timer:cancel(LoopDat#m3ua_state.t_ack), % transition into ASP_DOWN % signal this to the user send_prim_to_user(LoopDat, osmo_util:make_prim('M','ASP_DOWN',confirm)), {next_state, asp_down, LoopDat}; asp_active(#m3ua_msg{msg_class = ?M3UA_MSGC_ASPTM, msg_type = ?M3UA_MSGT_ASPTM_ASPIA_ACK}, LoopDat) -> timer:cancel(LoopDat#m3ua_state.t_ack), % transition into ASP_INACTIVE % signal this to the user send_prim_to_user(LoopDat, osmo_util:make_prim('M','ASP_INACTIVE',confirm)), {next_state, asp_inactive, LoopDat}; asp_active(#primitive{subsystem = 'M', gen_name = 'ASP_DOWN', spec_name = request, parameters = _Params}, LoopDat) -> % M-ASP_DOWN.req from user, generate message and send to remote peer send_msg_start_tack(LoopDat, asp_active, ?M3UA_MSGC_ASPSM, ?M3UA_MSGT_ASPSM_ASPDN, []); asp_active({timer_expired, t_ack, {?M3UA_MSGC_ASPSM, ?M3UA_MSGT_ASPSM_ASPDN, Params}}, LoopDat) -> send_msg_start_tack(LoopDat, asp_active, ?M3UA_MSGC_ASPSM, ?M3UA_MSGT_ASPSM_ASPDN, Params); asp_active(#primitive{subsystem = 'M', gen_name = 'ASP_INACTIVE', spec_name = request, parameters = _Params}, LoopDat) -> % M-ASP_INACTIVE.req from user, generate message and send to remote peer send_msg_start_tack(LoopDat, asp_active, ?M3UA_MSGC_ASPTM, ?M3UA_MSGT_ASPTM_ASPIA, []); asp_active({timer_expired, t_ack, {?M3UA_MSGC_ASPTM, ?M3UA_MSGT_ASPTM_ASPIA, Params}}, LoopDat) -> send_msg_start_tack(LoopDat, asp_active, ?M3UA_MSGC_ASPTM, ?M3UA_MSGT_ASPTM_ASPIA, Params); asp_active(#primitive{subsystem = 'MTP', gen_name = 'TRANSFER', spec_name = request, parameters = Params}, LoopDat) -> % MTP-TRANSFER.req from user app: Send message to remote peer OptList = [{?M3UA_IEI_PROTOCOL_DATA, Params}], Msg = #m3ua_msg{version = 1, msg_class = ?M3UA_MSGC_TRANSFER, msg_type = ?M3UA_MSGT_XFR_DATA, payload = OptList}, send_sctp_to_peer(LoopDat, Msg), {next_state, asp_active, LoopDat}; asp_active(#m3ua_msg{version = 1, msg_class = ?M3UA_MSGC_TRANSFER, msg_type = ?M3UA_MSGT_XFR_DATA, payload = Params}, LoopDat) -> % Data transfer from remote entity: Send MTP-TRANSFER.ind primitive to the user Mtp3 = proplists:get_value(?M3UA_IEI_PROTOCOL_DATA, Params), send_prim_to_user(LoopDat, osmo_util:make_prim('MTP','TRANSFER',indication,Mtp3)), {next_state, asp_active, LoopDat}; asp_active(#m3ua_msg{msg_class = ?M3UA_MSGC_ASPTM, msg_type = ?M3UA_MSGT_ASPTM_ASPIA_ACK}, LoopDat) -> timer:cancel(LoopDat#m3ua_state.t_ack), % transition to ASP_INACTIVE {next_state, asp_inactive, LoopDat}; asp_active(M3uaMsg, LoopDat) when is_record(M3uaMsg, m3ua_msg) -> rx_m3ua(M3uaMsg, asp_active, LoopDat). rx_sctp(_Anc, Data, State, LoopDat) -> M3uaMsg = m3ua_codec:parse_m3ua_msg(Data), gen_fsm:send_event(self(), M3uaMsg), {next_state, State, LoopDat}. rx_m3ua(Msg = #m3ua_msg{version = 1, msg_class = ?M3UA_MSGC_MGMT, msg_type = ?M3UA_MSGT_MGMT_NTFY}, State, LoopDat) -> send_prim_to_user(LoopDat, osmo_util:make_prim('M','NOTIFY',indication,[Msg])), {next_state, State, LoopDat}; rx_m3ua(Msg = #m3ua_msg{version = 1, msg_class = ?M3UA_MSGC_ASPSM, msg_type = ?M3UA_MSGT_ASPSM_BEAT}, State, LoopDat) -> % Send BEAT_ACK using the same payload as the BEAT msg send_sctp_to_peer(LoopDat, Msg#m3ua_msg{msg_type = ?M3UA_MSGT_ASPSM_BEAT_ACK}), {next_state, State, LoopDat}; rx_m3ua(Msg = #m3ua_msg{version = 1, msg_class = ?M3UA_MSGC_MGMT, msg_type = ?M3UA_MSGT_MGMT_ERR}, State, LoopDat) -> send_prim_to_user(LoopDat, osmo_util:make_prim('M','ERROR',indication,[Msg])), {next_state, State, LoopDat}; rx_m3ua(Msg = #m3ua_msg{version = 1, msg_class = ?M3UA_MSGC_SSNM, msg_type = MsgType, payload = Params}, State, LoopDat) -> % transform to classic MTP primitive and send up to the user Mtp = map_ssnm_to_mtp_prim(MsgType), send_prim_to_user(LoopDat, Mtp), {next_state, State, LoopDat}; rx_m3ua(Msg = #m3ua_msg{}, State, LoopDat) -> io:format("M3UA Unknown messge ~p in state ~p~n", [Msg, State]), {next_state, State, LoopDat}. % Transform the M3UA SSNM messages into classic MTP primitives map_ssnm_to_mtp_prim(MsgType) -> Mtp = #primitive{subsystem = 'MTP', spec_name = indication}, case MsgType of ?M3UA_MSGT_SSNM_DUNA -> Mtp#primitive{gen_name = 'PAUSE'}; ?M3UA_MSGT_SSNM_DAVA -> Mtp#primitive{gen_name = 'RESUME'}; ?M3UA_MSGT_SSNM_SCON -> Mtp#primitive{gen_name = 'STATUS'}; ?M3UA_MSGT_SSNM_DUPU -> Mtp#primitive{gen_name = 'STATUS'} end.