Add transport_opt() capx_strictness

To allow the Peer State Machine requirement that only the expected
capabilities exchange message be received in the relevant state to be
relaxed. If {capx_strictness, false} is configured then anything bu the
expected CER/CEA is ignored.

This is non-standard behaviour, and thusfar undocumented. Use at your
own risk.

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/diameter/src/base/diameter_peer_fsm.erl b/lib/diameter/src/base/diameter_peer_fsm.erl
index 996e75a8d3..83f4b2c856 100644
--- a/lib/diameter/src/base/diameter_peer_fsm.erl
+++ b/lib/diameter/src/base/diameter_peer_fsm.erl
@@ -128,6 +128,7 @@
                        %% outgoing DPR; boolean says whether or not
                        %% the request was sent explicitly with
                        %% diameter:call/4.
+         strict :: boolean(),
          length_errors :: exit | handle | discard,
          incoming_maxlen :: integer() | infinity}).
 
@@ -233,6 +234,7 @@ i({Ack, WPid, {M, Ref} = T, Opts, {SvcOpts, Nodes, Dict0, Svc}}) ->
                     proplists:get_value(dpa_timeout, Opts, ?DPA_TIMEOUT)}),
 
     Tmo = proplists:get_value(capx_timeout, Opts, ?CAPX_TIMEOUT),
+    Strictness = proplists:get_value(capx_strictness, Opts, true),
     OnLengthErr = proplists:get_value(length_errors, Opts, exit),
 
     {TPid, Addrs} = start_transport(T, Rest, Svc),
@@ -246,6 +248,7 @@ i({Ack, WPid, {M, Ref} = T, Opts, {SvcOpts, Nodes, Dict0, Svc}}) ->
            mode = M,
            service = svc(Svc, Addrs),
            length_errors = OnLengthErr,
+           strict = Strictness,
            incoming_maxlen = Maxlen}.
 %% The transport returns its local ip addresses so that different
 %% transports on the same service can use different local addresses.
@@ -614,6 +617,17 @@ recv1(_,
   when M < size(Bin) ->
     invalid(false, incoming_maxlen_exceeded, {size(Bin), H});
 
+%% Ignore anything but an expected CER/CEA if so configured. This is
+%% non-standard behaviour.
+recv1(Name, _, #state{state = {'Wait-CEA', _, _},
+                      strict = false})
+  when Name /= 'CEA' ->
+    ok;
+recv1(Name, _, #state{state = recv_CER,
+                      strict = false})
+  when Name /= 'CER' ->
+    ok;
+
 %% Incoming request after outgoing DPR: discard. Don't discard DPR, so
 %% both ends don't do so when sending simultaneously.
 recv1(Name,