Merge branch 'anders/diameter/3xxx_callback/OTP-10686'

* anders/diameter/3xxx_callback/OTP-10686:
  Add 3xxx suite for testing application_opt() request_errors
  Minor suite simplification
  Add application_opt() request_errors

12 files changed, 399 insertions, 150 deletions

diff --git a/lib/diameter/doc/src/diameter.xml b/lib/diameter/doc/src/diameter.xml
index ba9225da8b..accf21cf98 100644
--- a/lib/diameter/doc/src/diameter.xml
+++ b/lib/diameter/doc/src/diameter.xml
@@ -16,7 +16,7 @@
 <header>
 
 <copyright>
-<year>2011</year><year>2012</year>
+<year>2011</year><year>2013</year>
 <holder>Ericsson AB. All Rights Reserved.</holder>
 </copyright>
 <legalnotice>
@@ -206,11 +206,13 @@ probably avoid it.</p>
 <item>
 <p>
 Determines the manner in which incoming answer messages containing
-decode errors are handled.
+decode errors are handled.</p>
+
+<p>
 If <c>callback</c> then errors result in a &app_handle_answer;
 callback in the same fashion as for &app_handle_request;, with
 errors communicated in the <c>errors</c> field of the
-<c>#diameter_packet{}</c> record passed to the callback.
+<c>#diameter_packet{}</c> passed to the callback.
 If <c>report</c> then an answer containing errors is discarded
 without a callback and a warning report is written to the log.
 If <c>discard</c> then an answer containing errors is silently
@@ -224,6 +226,24 @@ question is as if a callback had taken place and returned
 Defaults to <c>report</c> if unspecified.</p>
 </item>
 
+<tag><c>{request_errors, answer_3xxx|callback}</c></tag>
+<item>
+<p>
+Determines the manner in which incoming requests are handled when an
+error other than 3007, DIAMETER_APPLICATION_UNSUPPORTED. (With which no
+application callback module can be associated.)</p>
+
+<p>
+If <c>answer_3xxx</c> then the request is answered by diameter
+without a &app_handle_request; callback taking place if a 3xxx series
+error (protocol errors) is detected.
+If <c>callback</c> then even 3xxx errors result in an application
+&app_handle_request; callback.</p>
+
+<p>
+Defaults to <c>answer_3xxx</c> if unspecified.</p>
+</item>
+
 </taglist>
 
 <marker id="call_opt"/>
@@ -534,7 +554,7 @@ Pkt    = #diameter_packet{}
 The RFC 3539 watchdog state machine has
 transitioned into (<c>up</c>) or out of (<c>down</c>) the OKAY
 state.
-If a <c>#diameter_packet{}</c> record is present in an <c>up</c> event
+If a <c>#diameter_packet{}</c> is present in an <c>up</c> event
 then there has been a capabilties exchange on a newly established
 transport connection and the record contains the received CER or CEA.
 Otherwise a connection has reestablished without the loss or
diff --git a/lib/diameter/include/diameter.hrl b/lib/diameter/include/diameter.hrl
index 5ee898c3dd..513665cec1 100644
--- a/lib/diameter/include/diameter.hrl
+++ b/lib/diameter/include/diameter.hrl
@@ -143,6 +143,6 @@
          init_state, %% option 'state', initial callback state
          id,         %% 32-bit unsigned application identifier = Dict:id()
          mutable = false, %% boolean(), do traffic callbacks modify state?
-         options = [{answer_errors, report}]}).  %% | callback | discard
-
+         options = [{answer_errors, report},      %% | callback | discard
+                    {request_errors, answer_3xxx}]}). %% | callback
 -endif. %% -ifdef(diameter_hrl).
diff --git a/lib/diameter/src/base/diameter.erl b/lib/diameter/src/base/diameter.erl
index f563d244f6..7359688404 100644
--- a/lib/diameter/src/base/diameter.erl
+++ b/lib/diameter/src/base/diameter.erl
@@ -306,7 +306,8 @@ call(SvcName, App, Message) ->
     | {module, app_module()}
     | {state, any()}
     | {call_mutates_state, boolean()}
-    | {answer_errors, callback|report|discard}.
+    | {answer_errors, callback|report|discard}
+    | {request_errors, callback|answer_3xxx}.
 
 -type app_alias()
    :: any().
diff --git a/lib/diameter/src/base/diameter_config.erl b/lib/diameter/src/base/diameter_config.erl
index 1486071573..889c75e3da 100644
--- a/lib/diameter/src/base/diameter_config.erl
+++ b/lib/diameter/src/base/diameter_config.erl
@@ -672,13 +672,15 @@ app_acc({application, Opts}, Acc) ->
     ModS  = get_opt(state, Opts, Alias),
     M = get_opt(call_mutates_state, Opts, false),
     A = get_opt(answer_errors, Opts, report),
+    R = get_opt(request_errors, Opts, answer_3xxx),
     [#diameter_app{alias = Alias,
                    dictionary = Dict,
                    id = cb(Dict, id),
                    module = init_mod(Mod),
                    init_state = ModS,
                    mutable = init_mutable(M),
-                   options = [{answer_errors, init_answers(A)}]}
+                   options = [{answer_errors, init_answers(A)},
+                              {request_errors, init_request_errors(R)}]}
      | Acc];
 app_acc(_, Acc) ->
     Acc.
@@ -722,6 +724,13 @@ init_answers(A)
 init_answers(A) ->
     ?THROW({answer_errors, A}).
 
+init_request_errors(P)
+  when callback == P;
+       answer_3xxx == P ->
+    P;
+init_request_errors(P) ->
+    ?THROW({request_errors, P}).
+
 %% Get a single value at the specified key.
 get_opt(Keys, List)
   when is_list(Keys) ->
diff --git a/lib/diameter/src/base/diameter_traffic.erl b/lib/diameter/src/base/diameter_traffic.erl
index 0de3825943..c3b9c195fb 100644
--- a/lib/diameter/src/base/diameter_traffic.erl
+++ b/lib/diameter/src/base/diameter_traffic.erl
@@ -205,16 +205,25 @@ recv_request({#diameter_app{id = Id, dictionary = Dict} = App, Caps},
            Caps,
            Dict0,
            RecvData,
-           diameter_codec:decode(Id, Dict, Pkt));
+           errors(Id, diameter_codec:decode(Id, Dict, Pkt)));
 %% Note that the decode is different depending on whether or not Id is
 %% ?APP_ID_RELAY.
 
 %%   DIAMETER_APPLICATION_UNSUPPORTED   3007
 %%      A request was sent for an application that is not supported.
 
-recv_request(#diameter_caps{} = Caps, TPid, Pkt, Dict0, _) ->
-    As = collect_avps(Pkt),
-    protocol_error(3007, TPid, Caps, Dict0, Pkt#diameter_packet{avps = As});
+recv_request(#diameter_caps{}
+             = Caps,
+             TPid,
+             #diameter_packet{errors = Es}
+             = Pkt,
+             Dict0,
+             _) ->
+    protocol_error(TPid,
+                   Caps,
+                   Dict0,
+                   Pkt#diameter_packet{avps = collect_avps(Pkt),
+                                       errors = [3007 | Es]});
 
 recv_request(false, _, _, _, _) ->  %% transport has gone down
     ok.
@@ -229,75 +238,25 @@ collect_avps(Pkt) ->
 
 %% recv_R/6
 
-%% Wrong number of bits somewhere in the message: reply.
-%%
-%%   DIAMETER_INVALID_AVP_BITS          3009
-%%      A request was received that included an AVP whose flag bits are
-%%      set to an unrecognized value, or that is inconsistent with the
-%%      AVP's definition.
-%%
-recv_R(_App,
+%% Answer 3xxx errors ourselves ...
+recv_R(#diameter_app{options = [_, {request_errors, answer_3xxx} | _]},
        TPid,
        Caps,
        Dict0,
        _RecvData,
-       #diameter_packet{errors = [Bs | _]} = Pkt)
-  when is_bitstring(Bs) ->
-    protocol_error(3009, TPid, Caps, Dict0, Pkt);
+       #diameter_packet{errors = [RC|_]} = Pkt)
+  when 3 == RC div 1000 ->
+    protocol_error(TPid, Caps, Dict0, Pkt);
 
-%% Either we support this application but don't recognize the command
-%% or we're a relay and the command isn't proxiable.
-%%
-%%   DIAMETER_COMMAND_UNSUPPORTED       3001
-%%      The Request contained a Command-Code that the receiver did not
-%%      recognize or support.  This MUST be used when a Diameter node
-%%      receives an experimental command that it does not understand.
-%%
-recv_R(#diameter_app{id = Id},
+%% ... or make a handle_request callback. Note that
+%% Pkt#diameter_packet.msg = undefined in the 3001 case.
+recv_R(App,
        TPid,
        Caps,
        Dict0,
-       _RecvData,
-       #diameter_packet{header = #diameter_header{is_proxiable = P},
-                        msg = M}
-       = Pkt)
-  when ?APP_ID_RELAY /= Id, undefined == M;
-       ?APP_ID_RELAY == Id, not P ->
-    protocol_error(3001, TPid, Caps, Dict0, Pkt);
-
-%% Error bit was set on a request.
-%%
-%%   DIAMETER_INVALID_HDR_BITS          3008
-%%      A request was received whose bits in the Diameter header were
-%%      either set to an invalid combination, or to a value that is
-%%      inconsistent with the command code's definition.
-%%
-recv_R(_App,
-       TPid,
-       Caps,
-       Dict0,
-       _RecvData,
-       #diameter_packet{header = #diameter_header{is_error = true}}
-       = Pkt) ->
-    protocol_error(3008, TPid, Caps, Dict0, Pkt);
-
-%% A message in a locally supported application or a proxiable message
-%% in the relay application. Don't distinguish between the two since
-%% each application has its own callback config. That is, the user can
-%% easily distinguish between the two cases.
-recv_R(App, TPid, Caps, Dict0, RecvData, Pkt) ->
-    request_cb(App, TPid, Caps, Dict0, RecvData, examine(Pkt)).
-
-%% Note that there may still be errors but these aren't protocol
-%% (3xxx) errors that lead to an answer-message.
-
-request_cb(App,
-           TPid,
-           Caps,
-           Dict0,
-           #recvdata{service_name = SvcName}
-           = RecvData,
-           Pkt) ->
+       #recvdata{service_name = SvcName}
+       = RecvData,
+       Pkt) ->
     request_cb(cb(App, handle_request, [Pkt, SvcName, {TPid, Caps}]),
                App,
                TPid,
@@ -307,20 +266,21 @@ request_cb(App,
                [],
                Pkt).
 
-%% examine/1
+%% errors/1
 %%
-%% Look for errors in a decoded message. It's odd/unfortunate that
-%% 501[15] aren't protocol errors.
+%% Look for errors in a decoded message, prepending the errors field
+%% with the first detected error. It's odd/unfortunate that 5011 isn't
+%% a protocol error.
 
 %%   DIAMETER_INVALID_MESSAGE_LENGTH 5015
 %%
 %%      This error is returned when a request is received with an invalid
 %%      message length.
 
-examine(#diameter_packet{header = #diameter_header{length = Len},
-                         bin = Bin,
-                         errors = Es}
-        = Pkt)
+errors(_, #diameter_packet{header = #diameter_header{length = Len},
+                           bin = Bin,
+                           errors = Es}
+          = Pkt)
   when Len < 20;
        0 /= Len rem 4;
        8*Len /= bit_size(Bin) ->
@@ -330,13 +290,47 @@ examine(#diameter_packet{header = #diameter_header{length = Len},
 %%      This error is returned when a request was received, whose version
 %%      number is unsupported.
 
-examine(#diameter_packet{header = #diameter_header{version = V},
-                         errors = Es}
-        = Pkt)
+errors(_, #diameter_packet{header = #diameter_header{version = V},
+                           errors = Es}
+          = Pkt)
   when V /= ?DIAMETER_VERSION ->
     Pkt#diameter_packet{errors = [5011 | Es]};
 
-examine(Pkt) ->
+%%   DIAMETER_INVALID_AVP_BITS          3009
+%%      A request was received that included an AVP whose flag bits are
+%%      set to an unrecognized value, or that is inconsistent with the
+%%      AVP's definition.
+
+errors(_, #diameter_packet{errors = [Bs | Es]} = Pkt)
+  when is_bitstring(Bs) ->
+    Pkt#diameter_packet{errors = [3009 | Es]};
+
+%%   DIAMETER_COMMAND_UNSUPPORTED       3001
+%%      The Request contained a Command-Code that the receiver did not
+%%      recognize or support.  This MUST be used when a Diameter node
+%%      receives an experimental command that it does not understand.
+
+errors(Id, #diameter_packet{header = #diameter_header{is_proxiable = P},
+                            msg = M,
+                            errors = Es}
+           = Pkt)
+  when ?APP_ID_RELAY /= Id, undefined == M;  %% don't know the command
+       ?APP_ID_RELAY == Id, not P ->         %% command isn't proxiable
+    Pkt#diameter_packet{errors = [3001 | Es]};
+
+%%   DIAMETER_INVALID_HDR_BITS          3008
+%%      A request was received whose bits in the Diameter header were
+%%      either set to an invalid combination, or to a value that is
+%%      inconsistent with the command code's definition.
+
+errors(_, #diameter_packet{header = #diameter_header{is_request = true,
+                                                     is_error = true},
+                            errors = Es}
+          = Pkt) ->
+    Pkt#diameter_packet{errors = [3008 | Es]};
+
+%% Green.
+errors(_, Pkt) ->
     Pkt.
 
 %% request_cb/8
@@ -365,7 +359,7 @@ request_cb({protocol_error, RC},
            _RecvData,
            Fs,
            Pkt)
-  when 3000 =< RC, RC < 4000 ->
+  when 3 == RC div 1000 ->
     protocol_error(RC, TPid, Caps, Dict0, Fs, Pkt);
 
 %% RFC 3588 says we must reply 3001 to anything unrecognized or
@@ -447,28 +441,36 @@ dict(Dict, Dict0, Rec) ->
         error:_ -> Dict
     end.
 
-%% protocol_error/6
-
-protocol_error(RC, TPid, Caps, Dict0, Fs, Pkt) ->
-    #diameter_caps{origin_host = {OH,_},
-                   origin_realm = {OR,_}}
-        = Caps,
-    #diameter_packet{avps = Avps, errors = Es}
-        = Pkt,
+%% protocol_error/5
 
+protocol_error(TPid,
+               #diameter_caps{origin_host  = {OH,_},
+                              origin_realm = {OR,_}},
+               Dict0,
+               Fs,
+               #diameter_packet{avps = Avps,
+                                errors = [RC|_]}
+               = Pkt) ->
     ?LOG({error, RC}, Pkt),
-    reply(answer_message({OH, OR, RC}, Dict0, Avps),
-          Dict0,
-          TPid,
-          Fs,
-          Pkt#diameter_packet{errors = [RC | Es]}).
+    reply(answer_message({OH, OR, RC}, Dict0, Avps), Dict0, TPid, Fs, Pkt).
 %% Note that reply/5 may set the result code once more. It's set in
 %% answer_message/3 in case reply/5 doesn't.
 
-%% protocol_error/5
+protocol_error(TPid, Caps, Dict0, Pkt) ->
+    protocol_error(TPid, Caps, Dict0, [], Pkt).
 
-protocol_error(RC, TPid, Caps, Dict0, Pkt) ->
-    protocol_error(RC, TPid, Caps, Dict0, [], Pkt).
+protocol_error(RC,
+               TPid,
+               Caps,
+               Dict0,
+               Fs,
+               #diameter_packet{errors = Es}
+               = Pkt) ->
+    protocol_error(TPid,
+                   Caps,
+                   Dict0,
+                   Fs,
+                   Pkt#diameter_packet{errors = [RC | Es]}).
 
 %% resend/7
 %%
@@ -661,15 +663,15 @@ rc(RC) ->
 
 %% rc/4
 
-rc(#diameter_packet{msg = Rec} = Pkt, RC, Failed, DictT) ->
-    Pkt#diameter_packet{msg = rc(Rec, RC, Failed, DictT)};
+rc(#diameter_packet{msg = Rec} = Pkt, RC, Failed, Dict) ->
+    Pkt#diameter_packet{msg = rc(Rec, RC, Failed, Dict)};
 
-rc(Rec, RC, Failed, DictT)
+rc(Rec, RC, Failed, Dict)
   when is_integer(RC) ->
     set(Rec,
-        lists:append([rc(Rec, {'Result-Code', RC}, DictT),
-                      failed_avp(Rec, Failed, DictT)]),
-        DictT).
+        lists:append([rc(Rec, {'Result-Code', RC}, Dict),
+                      failed_avp(Rec, Failed, Dict)]),
+        Dict).
 
 %% Reply as name and tuple list ...
 set([_|_] = Ans, Avps, _) ->
@@ -1268,11 +1270,12 @@ handle_answer(SvcName, App, {error, Req, Reason}) ->
     handle_error(App, Req, Reason, SvcName);
 
 handle_answer(SvcName,
-              #diameter_app{dictionary = Dict}
+              #diameter_app{dictionary = Dict,
+                            id = Id}
               = App,
               {answer, Req, Dict0, Pkt}) ->
     Mod = dict(Dict, Dict0, Pkt),
-    answer(examine(diameter_codec:decode(Mod, Pkt)),
+    answer(errors(Id, diameter_codec:decode(Mod, Pkt)),
            SvcName,
            Mod,
            App,
diff --git a/lib/diameter/test/diameter_3xxx_SUITE.erl b/lib/diameter/test/diameter_3xxx_SUITE.erl
new file mode 100644
index 0000000000..a87d5347db
--- /dev/null
+++ b/lib/diameter/test/diameter_3xxx_SUITE.erl
@@ -0,0 +1,214 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2013. All Rights Reserved.
+%%
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+%%
+%% Tests of application_opt() request_errors.
+%%
+
+-module(diameter_3xxx_SUITE).
+
+-export([suite/0,
+         all/0,
+         groups/0,
+         init_per_suite/1,
+         end_per_suite/1,
+         init_per_group/2,
+         end_per_group/2,
+         init_per_testcase/2,
+         end_per_testcase/2]).
+
+%% testcases
+-export([start/1,
+         send/1,
+         stop/1]).
+
+%% diameter callbacks
+-export([peer_up/3,
+         peer_down/3,
+         pick_peer/4,
+         prepare_request/3,
+         handle_answer/4,
+         handle_error/4,
+         handle_request/3]).
+
+-include("diameter.hrl").
+-include("diameter_gen_base_rfc6733.hrl").
+
+%% ===========================================================================
+
+-define(util, diameter_util).
+
+-define(CLIENT, "CLIENT").
+-define(SERVER, "SERVER").
+-define(REALM, "erlang.org").
+-define(HOST(Host, Realm), Host ++ [$.|Realm]).
+-define(DICT, diameter_gen_base_rfc6733).
+
+%% Config for diameter:start_service/2.
+-define(SERVICE(Name, RequestErrors),
+        [{'Origin-Host', Name ++ "." ++ ?REALM},
+         {'Origin-Realm', ?REALM},
+         {'Host-IP-Address', [{127,0,0,1}]},
+         {'Vendor-Id', 12345},
+         {'Product-Name', "OTP/diameter"},
+         {'Auth-Application-Id', [?DIAMETER_APP_ID_COMMON]},
+         {application, [{dictionary, ?DICT},
+                        {module, ?MODULE},
+                        {answer_errors, callback},
+                        {request_errors, RequestErrors}]}]).
+
+-define(SUCCESS,     ?'DIAMETER_BASE_RESULT-CODE_SUCCESS').
+-define(UNSUPPORTED, ?'DIAMETER_BASE_RESULT-CODE_COMMAND_UNSUPPORTED').
+
+-define(LOGOUT, ?'DIAMETER_BASE_TERMINATION-CAUSE_LOGOUT').
+
+-define(GROUPS, [answer_3xxx, callback]).
+-define(L, atom_to_list).
+
+%% ===========================================================================
+
+suite() ->
+    [{timetrap, {seconds, 60}}].
+
+all() ->
+    [{group, G} || G <- ?GROUPS].
+
+groups() ->
+    [{G, [], [start, send, stop]} || G <- ?GROUPS].
+
+init_per_suite(Config) ->
+    ok = diameter:start(),
+    Config.
+
+end_per_suite(_Config) ->
+    ok = diameter:stop().
+
+init_per_group(Group, Config) ->
+    [{group, Group} | Config].
+
+end_per_group(_, _) ->
+    ok.
+
+init_per_testcase(_Name, Config) ->
+    Config.
+
+end_per_testcase(_, _) ->
+    ok.
+
+origin(answer_3xxx)   -> 0;
+origin(callback) -> 1;
+
+origin(0) -> answer_3xxx;
+origin(1) -> callback.
+
+%% ===========================================================================
+
+%% start/1
+
+start(Config) ->
+    Group = proplists:get_value(group, Config),
+    ok = diameter:start_service(?SERVER, ?SERVICE(?L(Group), Group)),
+    ok = diameter:start_service(?CLIENT, ?SERVICE(?CLIENT, callback)),
+    LRef = ?util:listen(?SERVER, tcp),
+    ?util:connect(?CLIENT,
+                  tcp,
+                  LRef,
+                  [{capabilities, [{'Origin-State-Id', origin(Group)}]}]).
+
+%% stop/1
+
+stop(_Config) ->
+    ok = diameter:remove_transport(?CLIENT, true),
+    ok = diameter:remove_transport(?SERVER, true),
+    ok = diameter:stop_service(?SERVER),
+    ok = diameter:stop_service(?CLIENT).
+
+%% send/1
+%%
+%% Send a unknown command and expect a different result depending on
+%% whether or not the server gets a handle_request callback.
+
+%% Server handle_request discards the request.
+send(callback) ->
+    {error, timeout} = call();
+
+%% No handle_request, diameter answers.
+send(answer_3xxx) ->
+    #'diameter_base_answer-message'{'Result-Code' = ?UNSUPPORTED} = call();
+
+send(Config) ->
+    send(proplists:get_value(group, Config)).
+
+%% ===========================================================================
+
+call() ->
+    diameter:call(?CLIENT,
+                  ?DICT,
+                  #diameter_base_STR
+                  {'Termination-Cause' = ?LOGOUT,
+                   'Auth-Application-Id' = ?DIAMETER_APP_ID_COMMON}).
+
+%% ===========================================================================
+%% diameter callbacks
+
+%% peer_up/3
+
+peer_up(_SvcName, _Peer, State) ->
+    State.
+
+%% peer_down/3
+
+peer_down(_SvcName, _Peer, State) ->
+    State.
+
+%% pick_peer/4
+
+pick_peer([Peer], _, ?CLIENT, _State) ->
+    {ok, Peer}.
+
+%% prepare_request/3
+
+prepare_request(#diameter_packet{msg = Req0} = Pkt0, ?CLIENT, {_Ref, Caps}) ->
+    #diameter_caps{origin_host  = {OH, _},
+                   origin_realm = {OR, DR}}
+        = Caps,
+    Req = Req0#diameter_base_STR{'Session-Id' = diameter:session_id(OH),
+                                 'Origin-Host' = OH,
+                                 'Origin-Realm' = OR,
+                                 'Destination-Realm' = DR},
+    #diameter_packet{bin = <<H:5/binary, 275:24, T/binary>>}
+        = Pkt
+        = diameter_codec:encode(?DICT, Pkt0#diameter_packet{msg = Req}),
+
+    {send, Pkt#diameter_packet{bin = <<H/binary, 572:24, T/binary>>}}.
+
+%% handle_answer/4
+
+handle_answer(Pkt, _Req, ?CLIENT, _Peer) ->
+    Pkt#diameter_packet.msg.
+
+%% handle_error/4
+
+handle_error(Reason, _Req, ?CLIENT, _Peer) ->
+    {error, Reason}.
+
+%% handle_request/3
+
+handle_request(_, ?SERVER, _) ->
+    discard.
diff --git a/lib/diameter/test/diameter_failover_SUITE.erl b/lib/diameter/test/diameter_failover_SUITE.erl
index bb820a8bf2..0ea8ae2d4e 100644
--- a/lib/diameter/test/diameter_failover_SUITE.erl
+++ b/lib/diameter/test/diameter_failover_SUITE.erl
@@ -103,9 +103,9 @@
 -define(SUCCESS, 2001).
 
 %% Value of Termination-Cause determines client/server behaviour.
--define(LOGOUT,   ?'DIAMETER_BASE_TERMINATION-CAUSE_DIAMETER_LOGOUT').
--define(MOVED,    ?'DIAMETER_BASE_TERMINATION-CAUSE_DIAMETER_USER_MOVED').
--define(TIMEOUT,  ?'DIAMETER_BASE_TERMINATION-CAUSE_DIAMETER_SESSION_TIMEOUT').
+-define(LOGOUT,   ?'DIAMETER_BASE_TERMINATION-CAUSE_LOGOUT').
+-define(MOVED,    ?'DIAMETER_BASE_TERMINATION-CAUSE_USER_MOVED').
+-define(TIMEOUT,  ?'DIAMETER_BASE_TERMINATION-CAUSE_SESSION_TIMEOUT').
 
 %% ===========================================================================
 
diff --git a/lib/diameter/test/diameter_length_SUITE.erl b/lib/diameter/test/diameter_length_SUITE.erl
index 4e413e6a42..ffb19d2288 100644
--- a/lib/diameter/test/diameter_length_SUITE.erl
+++ b/lib/diameter/test/diameter_length_SUITE.erl
@@ -41,10 +41,10 @@
 %% diameter callbacks
 -export([peer_up/3,
          peer_down/3,
-         pick_peer/6,
-         prepare_request/5,
-         handle_answer/6,
-         handle_error/6,
+         pick_peer/5,
+         prepare_request/4,
+         handle_answer/5,
+         handle_error/5,
          handle_request/3]).
 
 -include("diameter.hrl").
@@ -73,14 +73,14 @@
                         {answer_errors, callback}]}]).
 
 -define(SUCCESS,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_SUCCESS').
+        ?'DIAMETER_BASE_RESULT-CODE_SUCCESS').
 -define(MISSING_AVP,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_MISSING_AVP').
+        ?'DIAMETER_BASE_RESULT-CODE_MISSING_AVP').
 -define(INVALID_MESSAGE_LENGTH,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_INVALID_MESSAGE_LENGTH').
+        ?'DIAMETER_BASE_RESULT-CODE_INVALID_MESSAGE_LENGTH').
 
 -define(LOGOUT,
-        ?'DIAMETER_BASE_TERMINATION-CAUSE_DIAMETER_LOGOUT').
+        ?'DIAMETER_BASE_TERMINATION-CAUSE_LOGOUT').
 
 -define(GROUPS, [exit, handle, discard]).
 
@@ -196,21 +196,18 @@ send(discard) ->
         = call(0);
 
 send(Config) ->
-    Group = proplists:get_value(group, Config),
-    put({?MODULE, group}, Group),
-    send(Group).
+    send(proplists:get_value(group, Config)).
 
 %% ===========================================================================
 
 call(Delta) ->
-    Group = get({?MODULE, group}),
     diameter:call(?CLIENT,
                   ?DICT,
                   #diameter_base_STR
                   {'Termination-Cause' = ?LOGOUT,
                    'Auth-Application-Id' = ?DIAMETER_APP_ID_COMMON,
                    'Origin-State-Id' = [7]},
-                  [{extra, [Group, Delta]}]).
+                  [{extra, [Delta]}]).
 
 %% ===========================================================================
 %% diameter callbacks
@@ -225,14 +222,14 @@ peer_up(_SvcName, _Peer, State) ->
 peer_down(_SvcName, _Peer, State) ->
     State.
 
-%% pick_peer/6
+%% pick_peer/5
 
-pick_peer([Peer], _, ?CLIENT, _State, _Group, _Delta) ->
+pick_peer([Peer], _, ?CLIENT, _State, _Delta) ->
     {ok, Peer}.
 
-%% prepare_request/5
+%% prepare_request/4
 
-prepare_request(Pkt, ?CLIENT, {_Ref, Caps}, _Group, Delta) ->
+prepare_request(Pkt, ?CLIENT, {_Ref, Caps}, Delta) ->
     {send, resize(Delta, prepare(Pkt, Caps))}.
 
 prepare(#diameter_packet{msg = Req0} = Pkt, Caps) ->
@@ -253,14 +250,14 @@ resize(Delta, #diameter_packet{bin = Bin} = Pkt) ->
 resize(Delta, <<V, Len:24, T/binary>>) ->
     <<V, (Len + Delta):24, T/binary>>.
 
-%% handle_answer/6
+%% handle_answer/5
 
-handle_answer(Pkt, _Req, ?CLIENT, _Peer, _Group, _Delta) ->
+handle_answer(Pkt, _Req, ?CLIENT, _Peer, _Delta) ->
     Pkt#diameter_packet.msg.
 
-%% handle_error/6
+%% handle_error/5
 
-handle_error(Reason, _Req, ?CLIENT, _Peer, _Group, _Delta) ->
+handle_error(Reason, _Req, ?CLIENT, _Peer, _Delta) ->
     {error, Reason}.
 
 %% handle_request/3
@@ -280,8 +277,12 @@ handle_request(Pkt, ?SERVER, {_Ref, Caps}) ->
 answer(Group, #diameter_packet{errors = Es}, Ans) ->
     answer(Group, Es, Ans);
 
+%% No errors: just answer.
 answer(_, [], Ans) ->
     {reply, Ans};
+
+%% Otherwise an invalid length should only reach the callback if
+%% length_errors = handle.
 answer(Group, [RC|_], Ans)
   when RC == ?INVALID_MESSAGE_LENGTH, Group == handle;
        RC /= ?INVALID_MESSAGE_LENGTH ->
diff --git a/lib/diameter/test/diameter_relay_SUITE.erl b/lib/diameter/test/diameter_relay_SUITE.erl
index f10d82bdf8..614eb4d4ca 100644
--- a/lib/diameter/test/diameter_relay_SUITE.erl
+++ b/lib/diameter/test/diameter_relay_SUITE.erl
@@ -107,7 +107,7 @@
 -define(LOOP_DETECTED, 3005).
 -define(UNABLE_TO_DELIVER, 3002).
 
--define(LOGOUT, ?'DIAMETER_BASE_TERMINATION-CAUSE_DIAMETER_LOGOUT').
+-define(LOGOUT, ?'DIAMETER_BASE_TERMINATION-CAUSE_LOGOUT').
 -define(AUTHORIZE_ONLY, ?'DIAMETER_BASE_RE-AUTH-REQUEST-TYPE_AUTHORIZE_ONLY').
 
 %% ===========================================================================
diff --git a/lib/diameter/test/diameter_tls_SUITE.erl b/lib/diameter/test/diameter_tls_SUITE.erl
index 6cc34b20c5..92a1113758 100644
--- a/lib/diameter/test/diameter_tls_SUITE.erl
+++ b/lib/diameter/test/diameter_tls_SUITE.erl
@@ -122,7 +122,7 @@
                   {capabilities, Caps}]}).
 
 -define(SUCCESS, 2001).
--define(LOGOUT, ?'DIAMETER_BASE_TERMINATION-CAUSE_DIAMETER_LOGOUT').
+-define(LOGOUT, ?'DIAMETER_BASE_TERMINATION-CAUSE_LOGOUT').
 
 %% ===========================================================================
 
diff --git a/lib/diameter/test/diameter_traffic_SUITE.erl b/lib/diameter/test/diameter_traffic_SUITE.erl
index 6727e88b66..d3d6fff705 100644
--- a/lib/diameter/test/diameter_traffic_SUITE.erl
+++ b/lib/diameter/test/diameter_traffic_SUITE.erl
@@ -178,27 +178,27 @@
                      diameter_gen_acct_rfc6733]]]).
 
 -define(SUCCESS,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_SUCCESS').
+        ?'DIAMETER_BASE_RESULT-CODE_SUCCESS').
 -define(COMMAND_UNSUPPORTED,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_COMMAND_UNSUPPORTED').
+        ?'DIAMETER_BASE_RESULT-CODE_COMMAND_UNSUPPORTED').
 -define(TOO_BUSY,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_TOO_BUSY').
+        ?'DIAMETER_BASE_RESULT-CODE_TOO_BUSY').
 -define(APPLICATION_UNSUPPORTED,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_APPLICATION_UNSUPPORTED').
+        ?'DIAMETER_BASE_RESULT-CODE_APPLICATION_UNSUPPORTED').
 -define(INVALID_HDR_BITS,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_INVALID_HDR_BITS').
+        ?'DIAMETER_BASE_RESULT-CODE_INVALID_HDR_BITS').
 -define(INVALID_AVP_BITS,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_INVALID_AVP_BITS').
+        ?'DIAMETER_BASE_RESULT-CODE_INVALID_AVP_BITS').
 -define(AVP_UNSUPPORTED,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_AVP_UNSUPPORTED').
+        ?'DIAMETER_BASE_RESULT-CODE_AVP_UNSUPPORTED').
 -define(UNSUPPORTED_VERSION,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_UNSUPPORTED_VERSION').
+        ?'DIAMETER_BASE_RESULT-CODE_UNSUPPORTED_VERSION').
 -define(REALM_NOT_SERVED,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_REALM_NOT_SERVED').
+        ?'DIAMETER_BASE_RESULT-CODE_REALM_NOT_SERVED').
 -define(UNABLE_TO_DELIVER,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_UNABLE_TO_DELIVER').
+        ?'DIAMETER_BASE_RESULT-CODE_UNABLE_TO_DELIVER').
 -define(INVALID_AVP_LENGTH,
-        ?'DIAMETER_BASE_RESULT-CODE_DIAMETER_INVALID_AVP_LENGTH').
+        ?'DIAMETER_BASE_RESULT-CODE_INVALID_AVP_LENGTH').
 
 -define(EVENT_RECORD,
         ?'DIAMETER_BASE_ACCOUNTING-RECORD-TYPE_EVENT_RECORD').
@@ -208,11 +208,11 @@
         ?'DIAMETER_BASE_RE-AUTH-REQUEST-TYPE_AUTHORIZE_AUTHENTICATE').
 
 -define(LOGOUT,
-        ?'DIAMETER_BASE_TERMINATION-CAUSE_DIAMETER_LOGOUT').
+        ?'DIAMETER_BASE_TERMINATION-CAUSE_LOGOUT').
 -define(BAD_ANSWER,
-        ?'DIAMETER_BASE_TERMINATION-CAUSE_DIAMETER_BAD_ANSWER').
+        ?'DIAMETER_BASE_TERMINATION-CAUSE_BAD_ANSWER').
 -define(USER_MOVED,
-        ?'DIAMETER_BASE_TERMINATION-CAUSE_DIAMETER_USER_MOVED').
+        ?'DIAMETER_BASE_TERMINATION-CAUSE_USER_MOVED').
 
 %% ===========================================================================
 
diff --git a/lib/diameter/test/modules.mk b/lib/diameter/test/modules.mk
index f575085843..32e5fb4613 100644
--- a/lib/diameter/test/modules.mk
+++ b/lib/diameter/test/modules.mk
@@ -42,7 +42,8 @@ MODULES = \
 	diameter_failover_SUITE \
 	diameter_dpr_SUITE \
 	diameter_event_SUITE \
-	diameter_length_SUITE
+	diameter_length_SUITE \
+	diameter_3xxx_SUITE
 
 HRL_FILES = \
 	diameter_ct.hrl