replace context key tupels with records (#279)

Instead of having to count fields in tuples, records allow us to
specify matches with the more readable record syntax.
They also give us `tagged keys`, that means we can deduce the type
of the key from the record tag.

This was originally part of the stateless work, but will also be
helpful for the cluster registry.

include/ergw.hrl

@@ -172,3 +172,7 @@
 	  ip                        :: {inet:ip4_address(),1..32}|
 				       {inet:ip6_address(),1..128}
 	}).
+
+-record(seid_key, {seid}).
+-record(context_key, {socket, id}).
+-record(socket_teid_key, {name, type, teid}).

src/ergw.erl

@@ -27,6 +27,7 @@
 	 terminate/2, code_change/3]).
 
 -include_lib("kernel/include/logger.hrl").
+-include("include/ergw.hrl").
 
 -define(SERVER, ?MODULE).
 -record(state, {tid :: ets:tid()}).
@@ -208,7 +209,7 @@ i(memory, path) ->
 
 i(memory, context) ->
     MemUsage =
-	lists:foldl(fun({{seid, _}, {_, Pid}}, Mem) ->
+	lists:foldl(fun({#seid_key{}, {_, Pid}}, Mem) ->
 			    {memory, M} = erlang:process_info(Pid, memory),
 			    Mem + M;
 		       (_, Mem) ->

src/ergw_api.erl

@@ -14,6 +14,8 @@
 
 -ignore_xref([peer/1, tunnel/1, memory/1]).
 
+-include("include/ergw.hrl").
+
 %%%===================================================================
 %%% API
 %%%===================================================================
@@ -38,8 +40,8 @@ tunnel(Socket) when is_atom(Socket) ->
     lists:foldl(fun collext_path_contexts/2, [], gtp_path_reg:all(Socket)).
 
 contexts(all) ->
-    lists:usort([Pid || {{_Socket, {teid, 'gtp-c', _TEID}}, {_, Pid}}
-				       <- gtp_context_reg:all(), is_pid(Pid)]).
+    lists:usort([Pid || {#socket_teid_key{type = 'gtp-c'}, {_, Pid}}
+			    <- gtp_context_reg:all(), is_pid(Pid)]).
 
 delete_contexts(all) ->
     lists:foreach(fun(Context) ->

src/ergw_context.erl

@@ -39,18 +39,23 @@
 %%% -----------------------------------------------------------------
 
 sx_report(#pfcp{type = session_report_request, seid = SEID} = Report) ->
-    apply2context({seid, SEID}, sx_report, [Report]).
+    apply2context(#seid_key{seid = SEID}, sx_report, [Report]).
 
 %% port_message/2
 port_message(Request, Msg) ->
     proc_lib:spawn(fun() -> port_message_h(Request, Msg) end),
     ok.
 
 %% port_message/3
-port_message(Keys, #request{socket = Socket} = Request, Msg)
-  when is_list(Keys) ->
-    Contexts = gtp_context_reg:match_keys(Socket, Keys),
-    port_message_ctx(Contexts, Request, Msg).
+port_message(Id, #request{socket = Socket} = Request, Msg) ->
+    Key = gtp_context:context_key(Socket, Id),
+    case gtp_context_reg:select(Key) of
+	[{Handler, Server}] when is_atom(Handler), is_pid(Server) ->
+	    Handler:port_message(Server, Request, Msg, false);
+	_Other ->
+	    ?LOG(debug, "unable to find context ~p", [Key]),
+	    throw({error, not_found})
+    end.
 
 %% port_message/4
 port_message(Key, Request, Msg, Resent) ->
@@ -69,9 +74,6 @@ apply2context(Key, F, A) ->
 	    {error, not_found}
     end.
 
-port_request_key(#request{key = ReqKey, socket = Socket}) ->
-    gtp_context:socket_key(Socket, ReqKey).
-
 %% TODO - MAYBE
 %%  it might be benificial to first perform the lookup and then enqueue
 %%
@@ -94,9 +96,9 @@ port_message_h(Request, #gtp{} = Msg) ->
 
 port_message_run(Request, #gtp{type = g_pdu} = Msg) ->
     port_message_p(Request, Msg);
-port_message_run(Request, Msg0) ->
+port_message_run(#request{key = ReqKey} = Request, Msg0) ->
     Msg = gtp_packet:decode_ies(Msg0),
-    case port_message(port_request_key(Request), Request, Msg, true) of
+    case port_message(ReqKey, Request, Msg, true) of
 	{error, not_found} ->
 	    port_message_p(Request, Msg);
 	Result ->
@@ -113,12 +115,6 @@ port_message_p(#request{socket = Socket} = Request, #gtp{tei = TEI} = Msg) ->
 	    Result
     end.
 
-port_message_ctx([{Handler, Server} | _], Request, Msg)
-  when is_atom(Handler), is_pid(Server) ->
-    Handler:port_message(Server, Request, Msg, false);
-port_message_ctx(_, _Request, _Msg) ->
-    throw({error, not_found}).
-
 load_class(#gtp{version = v1} = Msg) ->
     gtp_v1_c:load_class(Msg);
 load_class(#gtp{version = v2} = Msg) ->

src/ergw_gtp_socket.erl

@@ -166,10 +166,11 @@ make_seq_id(#gtp{version = Version, seq_no = SeqNo})
 make_seq_id(_) ->
     undefined.
 
-make_request(ArrivalTS, Src, IP, Port, Msg = #gtp{version = Version, type = Type}, Socket, Info) ->
+make_request(ArrivalTS, Src, IP, Port, Msg = #gtp{version = Version, type = Type},
+	     #socket{name = SocketName} = Socket, Info) ->
     SeqId = make_seq_id(Msg),
     #request{
-       key = {Socket, IP, Port, Type, SeqId},
+       key = {request, {SocketName, IP, Port, Type, SeqId}},
        socket = Socket,
        info = Info,
        src = Src,

src/ergw_pfcp.erl

@@ -158,7 +158,7 @@ outer_header_removal(v6) ->
     #outer_header_removal{header = 'GTP-U/UDP/IPv6'}.
 
 ctx_teid_key(#pfcp_ctx{name = Name}, TEI) ->
-    {Name, {teid, 'gtp-u', TEI}}.
+    #socket_teid_key{name = Name, type = 'gtp-u', teid = TEI}.
 
 up_inactivity_timer(#pfcp_ctx{up_inactivity_timer = Timer})
   when is_integer(Timer) ->

src/ergw_pfcp_context.erl

@@ -755,7 +755,7 @@ make_pctx_bearer_key(_, _, _, Keys) ->
     Keys.
 
 make_pctx_keys(Bearer, #pfcp_ctx{seid = #seid{cp = SEID}} = PCtx) ->
-    maps:fold(make_pctx_bearer_key(_, _, PCtx, _), [{seid, SEID}], Bearer).
+    maps:fold(make_pctx_bearer_key(_, _, PCtx, _), [#seid_key{seid = SEID}], Bearer).
 
 register_ctx_ids(Handler, Bearer, PCtx) ->
     Keys = make_pctx_keys(Bearer, PCtx),

src/ergw_sx_node.erl

@@ -183,7 +183,7 @@ init([Parent, Node, NodeSelect, IP4, IP6, NotifyUp]) ->
 
     RegKeys =
 	[gtp_context:socket_teid_key(Socket, TEI),
-	 {seid, SEID}],
+	 #seid_key{seid = SEID}],
     gtp_context_reg:register(RegKeys, ?MODULE, self()),
 
     Nodes = setup:get_env(ergw, nodes, #{}),

src/gtp_context.erl

@@ -28,7 +28,7 @@
 	 validate_options/3,
 	 validate_option/2,
 	 generic_error/3,
-	 socket_key/2, socket_teid_key/2]).
+	 context_key/2, socket_teid_key/2]).
 -export([usage_report_to_accounting/1,
 	 collect_charging_events/2]).
 
@@ -167,7 +167,7 @@ collect_charging_events(OldS, NewS) ->
 %% preexisting context should be deleted locally. This function does that.
 terminate_colliding_context(#tunnel{socket = Socket}, #context{context_id = Id})
   when Id /= undefined ->
-    case gtp_context_reg:lookup(socket_key(Socket, Id)) of
+    case gtp_context_reg:lookup(context_key(Socket, Id)) of
 	{?MODULE, Server} when is_pid(Server) ->
 	    gtp_context:terminate_context(Server);
 	_ ->
@@ -276,15 +276,15 @@ sx_report(Server, Report) ->
 port_message(Request, #gtp{version = v2, type = MsgType, tei = 0} = Msg)
   when MsgType == change_notification_request;
        MsgType == change_notification_response ->
-    Keys = gtp_v2_c:get_msg_keys(Msg),
-    ergw_context:port_message(Keys, Request, Msg);
+    Id = gtp_v2_c:get_context_id(Msg),
+    ergw_context:port_message(Id, Request, Msg);
 
 %% same as above for GTPv2
 port_message(Request, #gtp{version = v1, type = MsgType, tei = 0} = Msg)
   when MsgType == ms_info_change_notification_request;
        MsgType == ms_info_change_notification_response ->
-    Keys = gtp_v1_c:get_msg_keys(Msg),
-    ergw_context:port_message(Keys, Request, Msg);
+    Id = gtp_v1_c:get_context_id(Msg),
+    ergw_context:port_message(Id, Request, Msg);
 
 port_message(#request{socket = Socket, info = Info} = Request,
 		 #gtp{version = Version, tei = 0} = Msg) ->
@@ -733,11 +733,11 @@ generic_error(#request{socket = Socket} = Request,
 %%% Internal functions
 %%%===================================================================
 
-register_request(Handler, Server, #request{key = ReqKey, socket = Socket}) ->
-    gtp_context_reg:register([socket_key(Socket, ReqKey)], Handler, Server).
+register_request(Handler, Server, #request{key = ReqKey}) ->
+    gtp_context_reg:register([ReqKey], Handler, Server).
 
-unregister_request(#request{key = ReqKey, socket = Socket}) ->
-    gtp_context_reg:unregister([socket_key(Socket, ReqKey)], ?MODULE, self()).
+unregister_request(#request{key = ReqKey}) ->
+    gtp_context_reg:unregister([ReqKey], ?MODULE, self()).
 
 get_handler_if(Socket, #gtp{version = v1} = Msg) ->
     gtp_v1_c:get_handler(Socket, Msg);
@@ -794,7 +794,7 @@ context2keys(#tunnel{socket = Socket} = LeftTunnel, Bearer,
 	     #context{apn = APN, context_id = ContextId}) ->
     ordsets:from_list(
       tunnel2keys(LeftTunnel)
-      ++ [socket_key(Socket, ContextId) || ContextId /= undefined]
+      ++ [context_key(Socket, ContextId) || ContextId /= undefined]
       ++ maps:fold(bsf_keys(APN, _, _, _), [], Bearer)).
 
 tunnel2keys(Tunnel) ->
@@ -808,10 +808,8 @@ bsf_keys(APN, _, #bearer{vrf = VRF, local = #ue_ip{v4 = IPv4, v6 = IPv6}}, Keys)
 bsf_keys(_, _, _, Keys) ->
     Keys.
 
-socket_key(#socket{name = Name}, Key) ->
-    {Name, Key};
-socket_key({Name, _}, Key) ->
-    {Name, Key}.
+context_key(#socket{name = Name}, Id) ->
+    #context_key{socket = Name, id = Id}.
 
 tunnel_key(local, #tunnel{socket = Socket, local = #fq_teid{teid = TEID}}) ->
     socket_teid_key(Socket, TEID);
@@ -823,7 +821,7 @@ socket_teid_key(#socket{type = Type} = Socket, TEI) ->
     socket_teid_key(Socket, Type, TEI).
 
 socket_teid_key(#socket{name = Name}, Type, TEI) ->
-    {Name, {teid, Type, TEI}}.
+    #socket_teid_key{name = Name, type = Type, teid = TEI}.
 
 %%====================================================================
 %% Experimental Trigger Support

src/gtp_context_reg.erl

@@ -15,7 +15,6 @@
 -export([start_link/0]).
 -export([register/3, register_new/3, update/4, unregister/3,
 	 lookup/1, select/1,
-	 match_keys/2,
 	 await_unreg/1]).
 -export([all/0]).
 
@@ -50,19 +49,6 @@ lookup(Key) when is_tuple(Key) ->
 select(Key) ->
     ets:select(?SERVER, [{{Key, '$1'},[],['$1']}]).
 
-match_key(#socket{name = Name}, Key) ->
-    select({Name, Key}).
-
-match_keys(_, []) ->
-    throw({error, not_found});
-match_keys(Socket, [H|T]) ->
-    case match_key(Socket, H) of
-	[_|_] = Match ->
-	    Match;
-	_ ->
-	    match_keys(Socket, T)
-    end.
-
 register(Keys, Handler, Pid)
   when is_list(Keys), is_atom(Handler), is_pid(Pid) ->
     gen_server:call(?SERVER, {register, Keys, Handler, Pid}).

src/gtp_v1_c.erl

@@ -16,7 +16,7 @@
 	 build_echo_request/0,
 	 validate_teid/2,
 	 type/0, port/0,
-	 get_msg_keys/1, update_context_id/2,
+	 get_context_id/1, update_context_id/2,
 	 get_cause/1, get_common_flags/1,
 	 find_sender_teid/1,
 	 load_class/1]).
@@ -233,7 +233,7 @@ get_common_flags(IEs) ->
 get_ext_common_flags(IEs) ->
     get_element(?'Extended Common Flags', IEs, #extended_common_flags.flags, []).
 
-get_context_id(IEs) ->
+get_context_id(#gtp{version = v1, ie = IEs}) ->
     NSAPI = get_element(?'NSAPI', IEs, #nsapi.nsapi, '_'),
     UIMSI = proplists:get_bool('Unauthenticated IMSI', get_ext_common_flags(IEs)),
     %% order of key selection, first match terminates:
@@ -251,16 +251,8 @@ get_context_id(IEs) ->
 	    undefined
     end.
 
-get_msg_keys(#gtp{version = v1, ie = IEs}) ->
-    case get_context_id(IEs) of
-	undefined ->
-	    [];
-	Id ->
-	    [Id]
-    end.
-
-update_context_id(#gtp{version = v1, ie = IEs}, Context) ->
-    case get_context_id(IEs) of
+update_context_id(Msg, Context) ->
+    case get_context_id(Msg) of
 	{_, _, NSAPI} = Id when is_integer(NSAPI) ->
 	    Context#context{context_id = Id};
 	_ ->

src/gtp_v2_c.erl

@@ -16,7 +16,7 @@
 	 build_echo_request/0,
 	 validate_teid/2,
 	 type/0, port/0,
-	 get_msg_keys/1, update_context_id/2,
+	 get_context_id/1, update_context_id/2,
 	 get_cause/1, get_indication_flags/1,
 	 find_sender_teid/1,
 	 load_class/1]).
@@ -258,7 +258,7 @@ get_context_ebi(#{?'Bearer Contexts' :=
 get_context_ebi(_) ->
     '_'.
 
-get_context_id(IEs) ->
+get_context_id(#gtp{version = v2, ie = IEs}) ->
     EBI = get_context_ebi(IEs),
     UIMSI = proplists:get_bool('UIMSI', get_indication_flags(IEs)),
     case {UIMSI, IEs} of
@@ -270,16 +270,8 @@ get_context_id(IEs) ->
 	    undefined
     end.
 
-get_msg_keys(#gtp{version = v2, ie = IEs}) ->
-    case get_context_id(IEs) of
-	undefined ->
-	    [];
-	Id ->
-	    [Id]
-    end.
-
-update_context_id(#gtp{version = v2, ie = IEs}, Context) ->
-    case get_context_id(IEs) of
+update_context_id(Msg, Context) ->
+    case get_context_id(Msg) of
 	{_, _, EBI} = Id when is_integer(EBI) ->
 	    Context#context{context_id = Id};
 	_Other ->

test/ergw_test_lib.erl

@@ -43,6 +43,7 @@
 -export([init_ets/1]).
 
 -include("ergw_test_lib.hrl").
+-include_lib("stdlib/include/ms_transform.hrl").
 -include_lib("kernel/include/logger.hrl").
 -include_lib("common_test/include/ct.hrl").
 -include_lib("gtplib/include/gtp_packet.hrl").
@@ -544,7 +545,8 @@ add_cfg_value([H | T], Value, Config) ->
 %%%===================================================================
 
 outstanding_requests() ->
-    ets:match_object(gtp_context_reg, {{'_', {'_', '_', '_', '_', '_'}}, '_'}).
+    Ms = ets:fun2ms(fun({Key, _} = Obj) when element(1, Key) == 'request' -> Obj end),
+    ets:select(gtp_context_reg, Ms).
 
 wait4tunnels(Cnt) ->
     case [X || X = #{tunnels := T} <- ergw_api:peer(all), T /= 0] of

test/ergw_test_sx_up.erl

@@ -172,7 +172,8 @@ handle_call({send, Msg}, _From,
 	    #state{gtp = GtpSocket, cp_ip = IP, up_ip = UpIP} = State)
   when is_binary(Msg) ->
     {ok, SxPid} = ergw_sx_node_reg:lookup(ergw_inet:bin2ip(UpIP)),
-    [[SxTEI]] = ets:match(gtp_context_reg, {{'cp-socket',{teid,'gtp-u','$1'}},{'_',SxPid}}),
+    TEIDMatch = #socket_teid_key{name = 'cp-socket', type = 'gtp-u', teid = '$1', _ = '_'},
+    [[SxTEI]] = ets:match(gtp_context_reg, {TEIDMatch, {'_',SxPid}}),
     BinMsg = gtp_packet:encode(#gtp{version = v1, type = g_pdu, tei = SxTEI, ie = Msg}),
     ok = gen_udp:send(GtpSocket, IP, ?GTP1u_PORT, BinMsg),
     {reply, ok, State};