make the SG AS/ASP supervisor hierarchy work

src/sctp_m2ua.erl

@@ -0,0 +1,143 @@
+% M2UA in accordance with RFC3331 (http://tools.ietf.org/html/rfc3331)
+
+% (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/>.
+
+-module(sctp_m2ua).
+-author('Harald Welte <laforge@gnumonks.org>').
+-behaviour(sctp_core).
+
+-include_lib("kernel/include/inet_sctp.hrl").
+-include("osmo_util.hrl").
+-include("m2ua.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(m2ua_state, {
+		asp_pid,
+		last_bsn_received,
+		last_fsn_sent
+	}).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% gen_fsm callbacks
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+init(_InitOpts) ->
+	{ok, Asp} = gen_fsm:start_link(xua_asp_fsm, [sua_asp, [], Fun, [self()], self()], [{debug, [trace]}]),
+	{ok, #m2ua_state{last_bsn_received=16#ffffff, last_fsn_sent=16#ffffff, asp_pid=Asp}}
+
+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(_Info, State, LoopDat) ->
+	{next_state, State, LoopDat}.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% sctp_core callbacks
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+prim_up(#primitive{subsystem='M', gen_name = 'SCTP_ESTABLISH', spec_name = confirm}, State, LoopDat) ->
+	Asp = LoopDat#m2ua_state.asp_pid,
+	gen_fsm:send_event(Asp, osmo_util:make_prim('M','ASP_UP',request)),
+	{ignore, LoopDat};
+prim_up(#primitive{subsystem='M', gen_name = 'ASP_UP', spec_name = confirm}, State, LoopDat) ->
+	Asp = LoopDat#m2ua_state.asp_pid,
+	gen_fsm:send_event(Asp, osmo_util:make_prim('M','ASP_ACTIVE',request)),
+	{ignore, LoopDat};
+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 = ?M2UA_PPID}, Data, State, LoopDat) ->
+	Asp = LoopDat#m2ua_state.asp_pid,
+	{ok, M2ua} = xua_codec:parse_msg(Data),
+	% FIXME: check sequenc number linearity
+	case M2ua of
+		#xua_msg{msg_class = ?M3UA_MSGC_SSNM} ->
+			% FIXME
+			{ignore, LoopDat};
+		#xua_msg{msg_class = ?M3UA_MSGC_ASPSM} ->
+			gen_fsm:send_event(Asp, M2ua),
+			{ignore, LoopDat};
+		#xua_msg{msg_class = ?M3UA_MSGC_ASPTM} ->
+			gen_fsm:send_event(Asp, M2ua),
+			{ignore, LoopDat};
+		#xua_msg{msg_class = ?M2UA_CLASS_M2UA,
+			  msg_type = ?M2UA_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;
+		_ ->
+			% do something with link related msgs
+			io:format("M2UA 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),
+	M2ua = #xua_msg{msg_class = ?M2UA_CLASS_M2UA,
+			 msg_type = ?M2UA_TYPE_USER,
+			 mtp3 = Mtp3},
+	M2paBin = xua_codec:encode_msg(M2ua),
+	tx_sctp(?M2UA_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
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+tx_sctp(Stream, Payload) when is_integer(Stream), is_binary(Payload) ->
+	Param = {Stream, ?M2UA_PPID, Payload},
+	% sent to 'ourselves' (behaviour master module)
+	gen_fsm:send_event(self(), osmo_util:make_prim('SCTP','TRANSFER',request,Param)).

src/sg_as_sup.erl

@@ -39,7 +39,7 @@
 
 init([Name, Options]) ->
 	AsName = list_to_atom("sg_as_" ++ Name ++ "_fsm"),
-	StartArgs = [{local, AsName}, xua_as_fsm, [], Options],
+	StartArgs = [{local, AsName}, xua_as_fsm, [self()], Options],
 	StartFunc = {gen_fsm, start_link, StartArgs},
 	ChildSpec = {as_fsm, StartFunc, permanent, 4000, worker, [xua_as_fsm]},
 

src/sg_asp_sup.erl

@@ -39,6 +39,7 @@
 
 init([Name, AsSupPid]) ->
 	%AsName = list_to_atom("sg_as_" ++ Name ++ "_fsm"),
+	% supervisor:start_child/2 will append to this list of arguments
 	StartFunc = {xua_asp_fsm, start_link, []},
 	ChildSpec = {xua_asp_fsm, StartFunc, permanent, infinity, worker, [xua_asp_fsm]},
 	% simple_one_for_one will not start any children!

src/xua_as_fsm.erl

@@ -39,7 +39,7 @@
 -include("m3ua.hrl").
 
 % gen_fsm exports
--export([init/1, terminate/3, code_change/4, handle_event/3, handle_info/3]).
+-export([init/1, terminate/3, code_change/4, handle_event/3, handle_sync_event/4, handle_info/3]).
 
 % states in this FSM
 -export([as_down/2, as_inactive/2, as_active/2, as_pending/2]).
@@ -48,6 +48,7 @@
 -define(T_R_TIMEOUT, 2*60*100).
 
 -record(as_state, {
+		as_sup_pid,
 		role,
 		t_r,
 		asp_list
@@ -57,8 +58,9 @@
 % gen_fsm callbacks
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
-init([]) ->
+init([AsSupPid]) when is_pid(AsSupPid) ->
 	AsState = #as_state{asp_list = [],
+			    as_sup_pid = AsSupPid,
 			    role = sg},
 	{ok, as_down, AsState}.
 
@@ -70,6 +72,26 @@ terminate(Reason, State, _LoopDat) ->
 code_change(_OldVsn, StateName, LoopDat, _Extra) ->
 	{ok, StateName, LoopDat}.
 
+handle_sync_event({create_asp, Args}, From, State, LoopDat) ->
+	% resolve the ASP supervisor PID
+	AsSupPid = LoopDat#as_state.as_sup_pid,
+	AsChildList = supervisor:which_children(AsSupPid),
+	io:format("AsSupPid ~p, ChildList ~p~n", [AsSupPid, AsChildList]),
+	{asp_sup, AspSupPid, _, _} = lists:keyfind(asp_sup, 1, AsChildList),
+	% actually tell it to start a new ASP, prepend our own Pid
+	Ret = supervisor:start_child(AspSupPid, [self()|Args]),
+	LoopDatOut = case Ret of
+		{ok, AspPid} ->
+			link(AspPid),
+			LoopDat#as_state{asp_list = [AspPid|LoopDat#as_state.asp_list]};
+		{ok, AspPid, _} ->
+			link(AspPid),
+			LoopDat#as_state{asp_list = [AspPid|LoopDat#as_state.asp_list]};
+		_ ->
+			LoopDat
+	end,
+	{reply, Ret, State, LoopDatOut}.
+
 handle_event(Event, State, LoopDat) ->
 	io:format("Unknown Event ~p in state ~p~n", [Event, State]),
 	{next_state, State, LoopDat}.
@@ -78,7 +100,8 @@ handle_info({'EXIT', Pid, Reason}, State, LoopDat) ->
 	io:format("EXIT from Process ~p (~p), cleaning up ASP list~n",
 		  [Pid, Reason]),
 	% FIXME: send fake ASP-DOWN event about ASP to self
-	{next_state, State, LoopDat};
+	NewAspList = lists:delete(Pid, LoopDat#as_state.asp_list),
+	{next_state, State, LoopDat#as_state{asp_list = NewAspList}};
 
 handle_info(Info, State, LoopDat) ->
 	io:format("Unknown Info ~p in state ~p~n", [Info, State]),