Implement sequence masks

Code should be loaded in this order:

  diameter_session   (sequence/1)
  diameter_peer_fsm  (calls to sequence/1)
  diameter_service   (sequence config, mask in receive_message/3)
  diameter_watchdog  (mask in peer start and receive_message/3)
  diameter_config    (accept sequence config)

Order of diameter and diameter_peer doesn't matter.

1 files changed, 36 insertions, 11 deletions

diff --git a/lib/diameter/src/base/diameter_peer_fsm.erl b/lib/diameter/src/base/diameter_peer_fsm.erl
index 302540e76b..8ce6ea847a 100644
--- a/lib/diameter/src/base/diameter_peer_fsm.erl
+++ b/lib/diameter/src/base/diameter_peer_fsm.erl
@@ -55,10 +55,14 @@
 -define(TLS, 1).
 
 %% Keys in process dictionary.
--define(CB_KEY, cb).       %% capabilities callback
--define(DWA_KEY, dwa).     %% outgoing DWA
--define(Q_KEY, q).         %% transport start queue
--define(START_KEY, start). %% start of connected transport
+-define(CB_KEY, cb).         %% capabilities callback
+-define(DWA_KEY, dwa).       %% outgoing DWA
+-define(Q_KEY, q).           %% transport start queue
+-define(START_KEY, start).   %% start of connected transport
+-define(SEQUENCE_KEY, mask). %% mask for sequence numbers
+
+%% The default sequence mask.
+-define(NOMASK, {0,32}).
 
 %% A 2xxx series Result-Code. Not necessarily 2001.
 -define(IS_SUCCESS(N), 2 == (N) div 1000).
@@ -121,7 +125,8 @@
 %%% Output: Pid
 %%% ---------------------------------------------------------------------------
 
--spec start(T, [Opt], #diameter_service{})
+-spec start(T, [Opt], #diameter_service{}  %% from old code
+                    | {diameter:sequence(), #diameter_service{}})
    -> pid()
  when T   :: {connect|accept, diameter:transport_ref()},
       Opt :: diameter:transport_opt().
@@ -131,10 +136,8 @@
 %% specified on the transport in question. Check here that the list is
 %% still non-empty.
 
-start({_,_} = Type, Opts, #diameter_service{applications = Apps} = Svc) ->
-    [] /= Apps orelse ?ERROR({no_apps, Type, Opts}),
-    T = {self(), Type, Opts, Svc},
-    {ok, Pid} = diameter_peer_fsm_sup:start_child(T),
+start({_,_} = Type, Opts, MS) ->
+    {ok, Pid} = diameter_peer_fsm_sup:start_child({self(), Type, Opts, MS}),
     Pid.
 
 start_link(T) ->
@@ -153,12 +156,19 @@ init(T) ->
     proc_lib:init_ack({ok, self()}),
     gen_server:enter_loop(?MODULE, [], i(T)).
 
-i({WPid, T, Opts, #diameter_service{capabilities = Caps} = Svc}) ->
+i({WPid, Type, Opts, #diameter_service{} = Svc}) ->  %% from old code
+    i({WPid, Type, Opts, {?NOMASK, Svc}});
+
+i({WPid, T, Opts, {Mask, #diameter_service{applications = Apps,
+                                           capabilities = Caps}
+                         = Svc}}) ->
+    [] /= Apps orelse ?ERROR({no_apps, T, Opts}),
     putr(?DWA_KEY, dwa(Caps)),
     {M, Ref} = T,
     diameter_stats:reg(Ref),
     {[Ts], Rest} = proplists:split(Opts, [capabilities_cb]),
     putr(?CB_KEY, {Ref, [F || {_,F} <- Ts]}),
+    putr(?SEQUENCE_KEY, Mask),
     erlang:monitor(process, WPid),
     {TPid, Addrs} = start_transport(T, Rest, Svc),
     #state{parent = WPid,
@@ -464,9 +474,24 @@ build_CER(#state{service = #diameter_service{capabilities = Caps}}) ->
 %% encode/1
 
 encode(Rec) ->
-    #diameter_packet{bin = Bin} = diameter_codec:encode(?BASE, Rec),
+    Seq = diameter_session:sequence(sequence()),
+    Hdr = #diameter_header{version = ?DIAMETER_VERSION,
+                           end_to_end_id = Seq,
+                           hop_by_hop_id = Seq},
+    Pkt = #diameter_packet{header = Hdr,
+                           msg = Rec},
+    #diameter_packet{bin = Bin} = diameter_codec:encode(?BASE, Pkt),
     Bin.
 
+sequence() ->
+    case getr(?SEQUENCE_KEY) of
+        {_,_} = Mask ->
+            Mask;
+        undefined ->  %% started in old code
+            putr(?SEQUENCE_KEY, ?NOMASK),
+            ?NOMASK
+    end.
+
 %% recv/2
 
 %% RFC 3588 has result code 5015 for an invalid length but if a