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.

3 files changed, 20 insertions, 2 deletions

diff --git a/lib/diameter/src/base/diameter.erl b/lib/diameter/src/base/diameter.erl
index e8f2f63f86..253f64133c 100644
--- a/lib/diameter/src/base/diameter.erl
+++ b/lib/diameter/src/base/diameter.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2010-2016. All Rights Reserved.
+%% Copyright Ericsson AB 2010-2017. All Rights Reserved.
 %%
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -377,6 +377,7 @@ call(SvcName, App, Message) ->
     | {capabilities, [capability()]}
     | {capabilities_cb, evaluable()}
     | {capx_timeout, 'Unsigned32'()}
+    | {capx_strictness, boolean()}
     | {disconnect_cb, evaluable()}
     | {dpr_timeout, 'Unsigned32'()}
     | {dpa_timeout, 'Unsigned32'()}
diff --git a/lib/diameter/src/base/diameter_config.erl b/lib/diameter/src/base/diameter_config.erl
index fdbbd412a1..245a3ea7ac 100644
--- a/lib/diameter/src/base/diameter_config.erl
+++ b/lib/diameter/src/base/diameter_config.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2010-2016. All Rights Reserved.
+%% Copyright Ericsson AB 2010-2017. All Rights Reserved.
 %%
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -580,6 +580,9 @@ opt({K, Tmo})
        K == dpa_timeout ->
     ?IS_UINT32(Tmo);
 
+opt({capx_strictness, B}) ->
+    is_boolean(B);
+
 opt({length_errors, T}) ->
     lists:member(T, [exit, handle, discard]);
 
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,