251 lines
8.1 KiB
Erlang
251 lines
8.1 KiB
Erlang
% M2PA in accordance with RFC4165 (http://tools.ietf.org/html/rfc4665)
|
|
|
|
% (C) 2011-2012 by Harald Welte <laforge@gnumonks.org>
|
|
%
|
|
% 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 <http://www.gnu.org/licenses/>.
|
|
%
|
|
% 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(sctp_m2pa).
|
|
-author('Harald Welte <laforge@gnumonks.org>').
|
|
-behaviour(sctp_core).
|
|
|
|
-include_lib("kernel/include/inet_sctp.hrl").
|
|
-include("osmo_util.hrl").
|
|
-include("m2pa.hrl").
|
|
|
|
-export([init/1, terminate/3, code_change/4, handle_event/3, handle_info/3]).
|
|
|
|
-export([rx_sctp/4, mtp_xfer/2, state_change/3, prim_up/3]).
|
|
|
|
-record(m2pa_state, {
|
|
last_bsn_received,
|
|
last_fsn_sent,
|
|
lsc_pid,
|
|
iac_pid,
|
|
msu_fisu_accepted
|
|
}).
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
% gen_fsm callbacks
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
init(_InitOpts) ->
|
|
% start MTP2 IAC FSM pointing LSC, AERM and TXC to us
|
|
{ok, Lsc} = gen_fsm:start_link(mtp2_lsc, [self(), self(), self(), self(),self()], [{debug, [trace]}]),
|
|
{ok, Iac} = gen_fsm:sync_send_event(Lsc, get_iac_pid),
|
|
gen_fsm:send_event(Lsc, power_on),
|
|
{ok, #m2pa_state{last_bsn_received=16#ffffff, last_fsn_sent=16#ffffff,
|
|
lsc_pid=Lsc, iac_pid=Iac,
|
|
msu_fisu_accepted = 0}}.
|
|
|
|
terminate(Reason, _State, _LoopDat) ->
|
|
io:format("Terminating ~p (Reason ~p)~n", [?MODULE, Reason]),
|
|
ok.
|
|
|
|
code_change(_OldVsn, _State, LoopDat, _Extra) ->
|
|
{ok, LoopDat}.
|
|
|
|
handle_event(_Event, State, LoopDat) ->
|
|
{next_state, State, LoopDat}.
|
|
|
|
handle_info({lsc_txc, What}, State, LoopDat) when
|
|
What == start; What == retrieval_request_and_fsnc ->
|
|
{next_state, State, LoopDat};
|
|
handle_info({lsc_rc, accept_msu_fisu}, State, LoopDat) ->
|
|
{next_state, State, LoopDat#m2pa_state{msu_fisu_accepted = 1}};
|
|
handle_info({lsc_rc, reject_msu_fisu}, State, LoopDat) ->
|
|
{next_state, State, LoopDat#m2pa_state{msu_fisu_accepted = 0}};
|
|
handle_info({Who, What}, established, LoopDat) when Who == iac_txc; Who == lsc_txc ->
|
|
Ls = iac_to_ls(What),
|
|
send_linkstate(Ls, LoopDat),
|
|
{next_state, established, LoopDat};
|
|
handle_info(_Info, State, LoopDat) ->
|
|
{next_state, State, LoopDat}.
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
% sctp_core callbacks
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
prim_up(Prim, State, LoopDat) ->
|
|
% default: forward all primitives to the user
|
|
{ok, Prim, LoopDat}.
|
|
|
|
|
|
% sctp_core indicates that we have received some data...
|
|
rx_sctp(#sctp_sndrcvinfo{ppid = ?M2PA_PPID}, Data, State, LoopDat) ->
|
|
{ok, M2pa} = m2pa_codec:parse_msg(Data),
|
|
FsnRecv = M2pa#m2pa_msg.fwd_seq_nr,
|
|
% FIXME: check sequenc number linearity
|
|
case M2pa of
|
|
#m2pa_msg{msg_class = ?M2PA_CLASS_M2PA,
|
|
msg_type = ?M2PA_TYPE_USER} ->
|
|
Mtp3 = M2pa#m2pa_msg.mtp3,
|
|
case LoopDat#m2pa_state.msu_fisu_accepted of
|
|
1 ->
|
|
LoopDat2 = LoopDat#m2pa_state{last_bsn_received = FsnRecv},
|
|
case Mtp3 of
|
|
undefined ->
|
|
ok;
|
|
_ ->
|
|
send_userdata_ack(LoopDat2)
|
|
end,
|
|
gen_fsm:send_event(LoopDat#m2pa_state.lsc_pid, fisu_msu_received),
|
|
Prim = osmo_util:make_prim('MTP','TRANSFER',indication, Mtp3),
|
|
{ok, Prim, LoopDat2};
|
|
_ ->
|
|
{ignore, LoopDat}
|
|
end;
|
|
#m2pa_msg{msg_type = ?M2PA_TYPE_LINK} ->
|
|
handle_linkstate(M2pa, LoopDat),
|
|
{ignore, LoopDat};
|
|
_ ->
|
|
% do something with link related msgs
|
|
io:format("M2PA Unknown message ~p in state ~p~n", [M2pa, State]),
|
|
{ignore, State, LoopDat}
|
|
end.
|
|
|
|
% MTP-TRANSFER.req has arrived at sctp_core, encapsulate+tx it
|
|
mtp_xfer(Mtp3, LoopDat) ->
|
|
Fsn = inc_seq_nr(LoopDat#m2pa_state.last_fsn_sent),
|
|
M2pa = #m2pa_msg{msg_class = ?M2PA_CLASS_M2PA,
|
|
msg_type = ?M2PA_TYPE_USER,
|
|
fwd_seq_nr = Fsn,
|
|
back_seq_nr = LoopDat#m2pa_state.last_bsn_received,
|
|
mtp3 = Mtp3},
|
|
M2paBin = m2pa_codec:encode_msg(M2pa),
|
|
LoopDat2 = LoopDat#m2pa_state{last_fsn_sent = Fsn},
|
|
tx_sctp(?M2PA_STREAM_USER, M2paBin),
|
|
LoopDat2.
|
|
|
|
state_change(_, established, LoopDat) ->
|
|
% emulate a 'start' from LSC
|
|
gen_fsm:send_event(LoopDat#m2pa_state.lsc_pid, start),
|
|
LoopDat;
|
|
state_change(established, _, LoopDat) ->
|
|
gen_fsm:send_event(LoopDat#m2pa_state.lsc_pid, link_failure),
|
|
LoopDat;
|
|
state_change(_, _, LoopDat) ->
|
|
LoopDat.
|
|
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
% helper functions
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
inc_seq_nr(SeqNr) when is_integer(SeqNr) ->
|
|
SeqNr + 1 rem 16#FFFFFF.
|
|
|
|
handle_linkstate(M2pa, LoopDat) when is_record(M2pa, m2pa_msg) ->
|
|
Linkstate = proplists:get_value(link_state, M2pa#m2pa_msg.parameters),
|
|
LsMtp2 = ls_to_iac(Linkstate),
|
|
if LsMtp2 == fisu ->
|
|
case LoopDat#m2pa_state.msu_fisu_accepted of
|
|
1 ->
|
|
gen_fsm:send_event(LoopDat#m2pa_state.lsc_pid,
|
|
fisu_msu_received);
|
|
0 -> ok
|
|
end;
|
|
LsMtp2 == si_po ->
|
|
gen_fsm:send_event(LoopDat#m2pa_state.lsc_pid, LsMtp2);
|
|
LsMtp2 == si_n; LsMtp2 == si_e; LsMtp2 == si_o; LsMtp2 == si_os ->
|
|
gen_fsm:send_event(LoopDat#m2pa_state.lsc_pid, LsMtp2)
|
|
% IAC will receive the event as pass-through from LSC
|
|
%gen_fsm:send_event(LoopDat#m2pa_state.iac_pid, LsMtp2)
|
|
end.
|
|
|
|
% convert M2PA link state to MTP2
|
|
ls_to_iac(?M2PA_LS_OOS) ->
|
|
si_os;
|
|
ls_to_iac(?M2PA_LS_ALIGNMENT) ->
|
|
si_o;
|
|
ls_to_iac(?M2PA_LS_PROVING_NORMAL) ->
|
|
si_n;
|
|
ls_to_iac(?M2PA_LS_PROVING_EMERG) ->
|
|
si_e;
|
|
ls_to_iac(?M2PA_LS_READY) ->
|
|
fisu;
|
|
ls_to_iac(?M2PA_LS_PROC_OUTAGE) ->
|
|
si_po;
|
|
ls_to_iac(?M2PA_LS_PROC_RECOVERED) ->
|
|
fisu;
|
|
ls_to_iac(?M2PA_LS_BUSY) ->
|
|
si_b.
|
|
% FIXME: what about BUSY_ENDED?
|
|
|
|
|
|
% convert MTP2 link state to M2PA
|
|
iac_to_ls(si_os) ->
|
|
?M2PA_LS_OOS;
|
|
iac_to_ls(si_o) ->
|
|
?M2PA_LS_ALIGNMENT;
|
|
iac_to_ls(si_n) ->
|
|
?M2PA_LS_PROVING_NORMAL;
|
|
iac_to_ls(si_e) ->
|
|
?M2PA_LS_PROVING_EMERG;
|
|
iac_to_ls(fisu) ->
|
|
?M2PA_LS_READY;
|
|
iac_to_ls(msu) ->
|
|
?M2PA_LS_READY;
|
|
iac_to_ls(si_po) ->
|
|
?M2PA_LS_PROC_OUTAGE;
|
|
iac_to_ls(si_b) ->
|
|
?M2PA_LS_BUSY.
|
|
|
|
% Chapter 4.1.2 of RFC4165
|
|
ls_stream(?M2PA_LS_PROC_OUTAGE) ->
|
|
1;
|
|
ls_stream(?M2PA_LS_PROC_RECOVERED) ->
|
|
1;
|
|
ls_stream(Foo) when is_integer(Foo) ->
|
|
0.
|
|
|
|
send_linkstate(Ls, LoopDat) when is_integer(Ls) ->
|
|
Stream = ls_stream(Ls),
|
|
M2pa = #m2pa_msg{msg_class = ?M2PA_CLASS_M2PA,
|
|
msg_type = ?M2PA_TYPE_LINK,
|
|
fwd_seq_nr = LoopDat#m2pa_state.last_fsn_sent,
|
|
back_seq_nr = LoopDat#m2pa_state.last_bsn_received,
|
|
parameters = [{link_state, Ls}]},
|
|
M2paBin = m2pa_codec:encode_msg(M2pa),
|
|
tx_sctp(Stream, M2paBin),
|
|
LoopDat.
|
|
|
|
send_userdata_ack(LoopDat) ->
|
|
M2pa = #m2pa_msg{msg_class = ?M2PA_CLASS_M2PA,
|
|
msg_type = ?M2PA_TYPE_USER,
|
|
fwd_seq_nr = LoopDat#m2pa_state.last_fsn_sent,
|
|
back_seq_nr = LoopDat#m2pa_state.last_bsn_received},
|
|
M2paBin = m2pa_codec:encode_msg(M2pa),
|
|
tx_sctp(0, M2paBin).
|
|
|
|
tx_sctp(Stream, Payload) when is_integer(Stream), is_binary(Payload) ->
|
|
Param = {Stream, ?M2PA_PPID, Payload},
|
|
% sent to 'ourselves' (behaviour master module)
|
|
gen_fsm:send_event(self(), osmo_util:make_prim('SCTP','TRANSFER',request,Param)).
|