From ee62825c1ca752f401662529af7fe8fe247c2165 Mon Sep 17 00:00:00 2001
From: Anders Svensson <anders@erlang.org>
Date: Wed, 30 Aug 2017 18:04:04 +0200
Subject: Fix extraction of Experimental-Result for counter keys

The introduction of decode_format in commit 722fa415 (and then 55e65b26)
meant the value was not necessarily the intended tuple.
---
 lib/diameter/src/base/diameter_traffic.erl | 67 ++++++++++++++++++++----------
 1 file changed, 44 insertions(+), 23 deletions(-)

(limited to 'lib/diameter/src/base/diameter_traffic.erl')

diff --git a/lib/diameter/src/base/diameter_traffic.erl b/lib/diameter/src/base/diameter_traffic.erl
index 27a41d6eb0..4388175c3a 100644
--- a/lib/diameter/src/base/diameter_traffic.erl
+++ b/lib/diameter/src/base/diameter_traffic.erl
@@ -1891,16 +1891,12 @@ str(T) ->
 
 %% get_avp/3
 %%
-%% Find an AVP in a message of one of three forms:
-%%
-%% - a message record (as generated from a .dia spec) or
-%% - a list of an atom message name followed by 2-tuple, avp name/value pairs.
-%% - a list of a #diameter_header{} followed by #diameter_avp{} records,
-%%
-%% In the first two forms a dictionary module is used at encode to
-%% identify the type of the AVP and its arity in the message in
-%% question. The third form allows messages to be sent as is, without
-%% a dictionary, which is needed in the case of relay agents, for one.
+%% Find an AVP in a message in one of the decoded formats, or as a
+%% header/avps list. There are only four AVPs that are extracted here:
+%% Result-Code and Experimental-Result in order when constructing
+%% counter keys, and Destination-Host/Realm when selecting a next-hop
+%% peer. Experimental-Result is the only of type Grouped, and is given
+%% special treatment in order to return the value as a record.
 
 %% Messages will be header/avps list as a relay and the only AVP's we
 %% look for are in the common dictionary. This is required since the
@@ -1909,12 +1905,12 @@ str(T) ->
 get_avp(?RELAY, Name, Msg) ->
     get_avp(?BASE, Name, Msg);
 
-%% Message is a header/avps list.
+%% Message as header/avps list.
 get_avp(Dict, Name, [#diameter_header{} | Avps]) ->
     try
-        {Code, _, VId} = Dict:avp_header(Name),
-        A = find_avp(Code, VId, Avps),
-        (avp_decode(Dict, Name, ungroup(A)))#diameter_avp{name = Name}
+        {Code, _, Vid} = Dict:avp_header(Name),
+        A = find_avp(Code, Vid, Avps),
+        avp_decode(Dict, Name, ungroup(A))
     catch
         error: _ ->
             undefined
@@ -1924,20 +1920,33 @@ get_avp(Dict, Name, [#diameter_header{} | Avps]) ->
 get_avp(_, Name, [_MsgName | Avps]) ->
     case find(Name, Avps) of
         {_, V} ->
-            #diameter_avp{name = Name, value = V};
+            #diameter_avp{name = Name, value = value(Name, V)};
         _ ->
             undefined
     end;
 
-%% ... or record (but not necessarily).
+%% ... or record.
 get_avp(Dict, Name, Rec) ->
-    try
-        #diameter_avp{name = Name, value = Dict:'#get-'(Name, Rec)}
+    try Dict:'#get-'(Name, Rec) of
+        V ->
+            #diameter_avp{name = Name, value = value(Name, V)}
     catch
         error:_ ->
             undefined
     end.
 
+value('Experimental-Result' = N, #{'Vendor-Id' := Vid,
+                                   'Experimental-Result-Code' := RC}) ->
+    {N, Vid, RC};
+value('Experimental-Result' = N, [{'Experimental-Result-Code', RC},
+                                  {'Vendor-Id', Vid}]) ->
+    {N, Vid, RC};
+value('Experimental-Result' = N, [{'Vendor-Id', Vid},
+                                  {'Experimental-Result-Code', RC}]) ->
+    {N, Vid, RC};
+value(_, V) ->
+    V.
+
 %% find/2
 
 find(Key, Map)
@@ -1967,14 +1976,25 @@ ungroup(Avp) ->
 
 %% avp_decode/3
 
-avp_decode(Dict, Name, #diameter_avp{value = undefined,
+%% Ensure Experimental-Result is decoded as record, since this format
+%% is used for counter keys.
+avp_decode(Dict, 'Experimental-Result' = N, #diameter_avp{data = Bin}
+                                            = Avp)
+  when is_binary(Bin) ->
+    {V,_} = Dict:avp(decode, Bin, N, decode_opts(Dict)),
+    Avp#diameter_avp{name = N, value = V};
+
+avp_decode(Dict, Name, #diameter_avp{value = X,
                                      data = Bin}
                        = Avp)
-  when is_binary(Bin) ->
+  when is_binary(Bin), X == undefined orelse X == false ->
     V = Dict:avp(decode, Bin, Name, decode_opts(Dict)),
-    Avp#diameter_avp{value = V};
-avp_decode(_, _, #diameter_avp{} = Avp) ->
-    Avp.
+    Avp#diameter_avp{name = Name, value = V};
+
+avp_decode(_, Name, #diameter_avp{} = Avp) ->
+    Avp#diameter_avp{name = Name}.
+
+%% cb/3
 
 cb(#diameter_app{module = [_|_] = M}, F, A) ->
     eval(M, F, A).
@@ -1991,4 +2011,5 @@ decode_opts(Dict) ->
       string_decode => false,
       strict_mbit => false,
       failed_avp => false,
+      module => Dict,
       dictionary => Dict}.
-- 
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