Remove use of process dictionary in decode

By passing additional arguments through it.

9 files changed, 730 insertions, 910 deletions

diff --git a/lib/diameter/include/diameter_gen.hrl b/lib/diameter/include/diameter_gen.hrl
index 67b9f890a7..1683d93557 100644
--- a/lib/diameter/include/diameter_gen.hrl
+++ b/lib/diameter/include/diameter_gen.hrl
@@ -29,18 +29,6 @@
 %% Tag common to generated dictionaries.
 -define(TAG, diameter_gen).
 
-%% Key to a value in the process dictionary that determines whether or
-%% not an unrecognized AVP setting the M-bit should be regarded as an
-%% error or not. See is_strict/0. This is only used to relax M-bit
-%% interpretation inside Grouped AVPs not setting the M-bit. The
-%% service_opt() strict_mbit can be used to disable the check
-%% globally.
--define(STRICT_KEY, strict).
-
-%% Key that says whether or not we should do a best-effort decode
-%% within Failed-AVP.
--define(FAILED_KEY, failed).
-
 -type parent_name()   :: atom().  %% parent = Message or AVP
 -type parent_record() :: tuple(). %%
 -type avp_name()   :: atom().
@@ -51,33 +39,21 @@
 -type grouped_avp() :: nonempty_improper_list(#diameter_avp{}, [avp()]).
 -type avp() :: non_grouped_avp() | grouped_avp().
 
-%% Use a (hopefully) unique key when manipulating the process
-%% dictionary.
-
-putr(K,V) ->
-    put({?TAG, K}, V).
-
-getr(K) ->
-    get({?TAG, K}).
-
-eraser(K) ->
-    erase({?TAG, K}).
-
 %% ---------------------------------------------------------------------------
-%% # encode_avps/2
+%% # encode_avps/3
 %% ---------------------------------------------------------------------------
 
--spec encode_avps(parent_name(), parent_record() | avp_values())
+-spec encode_avps(parent_name(), parent_record() | avp_values(), term())
    -> iolist()
     | no_return().
 
-encode_avps(Name, Vals)
+encode_avps(Name, Vals, Opts)
   when is_list(Vals) ->
-    encode_avps(Name, '#set-'(Vals, newrec(Name)));
+    encode_avps(Name, '#set-'(Vals, newrec(Name)), Opts);
 
-encode_avps(Name, Rec) ->
+encode_avps(Name, Rec, Opts) ->
     try
-        encode(Name, Rec)
+        encode(Name, Rec, Opts)
     catch
         throw: {?MODULE, Reason} ->
             diameter_lib:log({encode, error},
@@ -94,99 +70,99 @@ encode_avps(Name, Rec) ->
             erlang:error({encode_failure, Reason, Name, Stack})
     end.
 
-%% encode/2
+%% encode/3
 
-encode(Name, Rec) ->
-    [encode(Name, F, V) || {F,V} <- '#get-'(Rec)].
+encode(Name, Rec, Opts) ->
+    [encode(Name, F, V, Opts) || {F,V} <- '#get-'(Rec)].
 
-%% encode/3
+%% encode/4
 
-encode(Name, AvpName, Values) ->
-    e(Name, AvpName, avp_arity(Name, AvpName), Values).
+encode(Name, AvpName, Values, Opts) ->
+    enc(Name, AvpName, avp_arity(Name, AvpName), Values, Opts).
 
-%% e/4
+%% enc/5
 
-e(_, AvpName, 1, undefined) ->
+enc(_, AvpName, 1, undefined, _) ->
     ?THROW([mandatory_avp_missing, AvpName]);
 
-e(Name, AvpName, 1, Value) ->
-    e(Name, AvpName, [Value]);
+enc(Name, AvpName, 1, Value, Opts) ->
+    enc(Name, AvpName, [Value], Opts);
 
-e(_, _, {0,_}, []) ->
+enc(_, _, {0,_}, [], _) ->
     [];
 
-e(_, AvpName, _, T)
+enc(_, AvpName, _, T, _)
   when not is_list(T) ->
     ?THROW([repeated_avp_as_non_list, AvpName, T]);
 
-e(_, AvpName, {Min, _}, L)
+enc(_, AvpName, {Min, _}, L, _)
   when length(L) < Min ->
     ?THROW([repeated_avp_insufficient_arity, AvpName, Min, L]);
 
-e(_, AvpName, {_, Max}, L)
+enc(_, AvpName, {_, Max}, L, _)
   when Max < length(L) ->
     ?THROW([repeated_avp_excessive_arity, AvpName, Max, L]);
 
-e(Name, AvpName, _, Values) ->
-    e(Name, AvpName, Values).
+enc(Name, AvpName, _, Values, Opts) ->
+    enc(Name, AvpName, Values, Opts).
 
-%% e/3
+%% enc/4
 
-e(Name, 'AVP', Values) ->
-    [pack_AVP(Name, A) || A <- Values];
+enc(Name, 'AVP', Values, Opts) ->
+    [enc_AVP(Name, A, Opts) || A <- Values];
 
-e(_, AvpName, Values) ->
-    e(AvpName, Values).
+enc(_, AvpName, Values, Opts) ->
+    enc(AvpName, Values, Opts).
 
-%% e/2
+%% env/3
 
-e(AvpName, Values) ->
+enc(AvpName, Values, Opts) ->
     H = avp_header(AvpName),
-    [diameter_codec:pack_avp(H, avp(encode, V, AvpName)) || V <- Values].
+    [diameter_codec:pack_data(H, avp(encode, V, AvpName, Opts))
+     || V <- Values].
 
-%% pack_AVP/2
+%% enc_AVP/3
 
 %% No value: assume AVP data is already encoded. The normal case will
 %% be when this is passed back from #diameter_packet.errors as a
 %% consequence of a failed decode. Any AVP can be encoded this way
 %% however, which side-steps any arity checks for known AVP's and
 %% could potentially encode something unfortunate.
-pack_AVP(_, #diameter_avp{value = undefined} = A) ->
-    diameter_codec:pack_avp(A);
+enc_AVP(_, #diameter_avp{value = undefined} = A, Opts) ->
+    diameter_codec:pack_avp(A, Opts);
 
 %% Missing name for value encode.
-pack_AVP(_, #diameter_avp{name = N, value = V})
+enc_AVP(_, #diameter_avp{name = N, value = V}, _)
   when N == undefined;
        N == 'AVP' ->
     ?THROW([value_with_nameless_avp, N, V]);
 
 %% Or not. Ensure that 'AVP' is the appropriate field. Note that if we
 %% don't know this AVP at all then the encode will fail.
-pack_AVP(Name, #diameter_avp{name = AvpName,
-                             value = Data}) ->
+enc_AVP(Name, #diameter_avp{name = AvpName, value = Data}, Opts) ->
     0 == avp_arity(Name, AvpName)
         orelse ?THROW([known_avp_as_AVP, Name, AvpName, Data]),
-    e(AvpName, [Data]);
+    enc(AvpName, [Data], Opts);
 
 %% The backdoor ...
-pack_AVP(_, {AvpName, Value}) ->
-    e(AvpName, [Value]);
+enc_AVP(_, {AvpName, Value}, Opts) ->
+    enc(AvpName, [Value], Opts);
 
 %% ... and the side door.
-pack_AVP(_Name, {_Dict, _AvpName, _Data}= T) ->
-    diameter_codec:pack_avp(#diameter_avp{data = T}).
+enc_AVP(_Name, {_Dict, _AvpName, _Data} = T, Opts) ->
+    diameter_codec:pack_avp(#diameter_avp{data = T}, Opts).
 
 %% ---------------------------------------------------------------------------
 %% # decode_avps/2
 %% ---------------------------------------------------------------------------
 
--spec decode_avps(parent_name(), [#diameter_avp{}])
+-spec decode_avps(parent_name(), [#diameter_avp{}], map())
    -> {parent_record(), [avp()], Failed}
  when Failed :: [{5000..5999, #diameter_avp{}}].
 
-decode_avps(Name, Recs) ->
+decode_avps(Name, Recs, Opts) ->
     {Avps, {Rec, Failed}}
-        = mapfoldl(fun(T,A) -> decode(Name, T, A) end,
+        = mapfoldl(fun(T,A) -> decode(Name, Opts, T, A) end,
                       {newrec(Name), []},
                       Recs),
     {Rec, Avps, Failed ++ missing(Rec, Name, Failed)}.
@@ -284,20 +260,16 @@ empty_avp(Name, {Code, Flags, VId}) ->
 %%   specific errors that can be described by this AVP are described in
 %%   the following section.
 
-%% decode/3
-
-decode(Name, #diameter_avp{code = Code, vendor_id = Vid} = Avp, Acc) ->
-    decode(Name, avp_name(Code, Vid), Avp, Acc).
-
 %% decode/4
 
-%% AVP is defined in the dictionary ...
-decode(Name, {AvpName, Type}, Avp, Acc) ->
-    d(Name, Avp#diameter_avp{name = AvpName, type = Type}, Acc);
+decode(Name, Opts, #diameter_avp{code = Code, vendor_id = Vid} = Avp, Acc) ->
+    decode(Name, Opts, avp_name(Code, Vid), Avp, Acc).
 
-%% ... or not.
-decode(Name, 'AVP', Avp, Acc) ->
-    decode_AVP(Name, Avp, Acc).
+%% decode/5
+
+%% AVP not in dictionary.
+decode(Name, Opts, 'AVP', Avp, Acc) ->
+    decode_AVP(Name, Avp, Opts, Acc);
 
 %% 6733, 4.4:
 %%
@@ -346,47 +318,63 @@ decode(Name, 'AVP', Avp, Acc) ->
 %% defined the RFC's "unrecognized", which is slightly stronger than
 %% "not defined".)
 
-%% d/3
-
-d(Name, Avp, Acc) ->
-    #diameter_avp{name = AvpName,
-                  data = Data,
-                  type = Type,
-                  is_mandatory = M}
+decode(Name, Opts0, {AvpName, Type}, Avp, Acc) ->
+    #diameter_avp{data = Data, is_mandatory = M}
         = Avp,
 
-    %% Use the process dictionary is to keep track of whether or not
-    %% to ignore an M-bit on an encapsulated AVP. Not ideal, but the
-    %% alternative requires widespread changes to be able to pass the
-    %% value around through the entire decode. The solution here is
-    %% simple in comparison, both to implement and to understand.
+    %% Whether or not to ignore an M-bit on an encapsulated AVP, or on
+    %% all AVPs with the service_opt() strict_mbit.
+    Opts1 = set_strict(Type, M, Opts0),
 
-    Strict = relax(Type, M),
+    %% Whether or not we're decoding within Failed-AVP and should
+    %% ignore decode errors.
+    #{dictionary := AppMod, failed_avp := Failed}
+        = Opts
+        = set_failed(Name, Opts1), %% Not AvpName or else a failed Failed-AVP
+                                   %% decode is packed into 'AVP'.
 
-    %% Use the process dictionary again to keep track of whether we're
-    %% decoding within Failed-AVP and should ignore decode errors
-    %% altogether.
-
-    Failed = relax(Name),  %% Not AvpName or else a failed Failed-AVP
-                           %% decode is packed into 'AVP'.
-    Mod = dict(Failed),    %% Dictionary to decode in.
+    %% Reset the dictionary for best-effort decode of Failed-AVP.
+    Mod = if Failed ->
+                  AppMod;
+             true ->
+                  ?MODULE
+          end,
 
     %% On decode, a Grouped AVP is represented as a #diameter_avp{}
     %% list with AVP as head and component AVPs as tail. On encode,
     %% data can be a list of component AVPs.
 
-    try Mod:avp(decode, Data, AvpName) of
-        V ->
-            {H, A} = ungroup(V, Avp),
-            {H, pack_avp(Name, A, Acc)}
+    try Mod:avp(decode, Data, AvpName, Opts) of
+        {Rec, As} when Type == 'Grouped' ->
+            A = Avp#diameter_avp{name = AvpName,
+                                 value = Rec,
+                                 type = Type},
+            {[A|As], pack_avp(Name, A, Opts, Acc)};
+
+        V when Type /= 'Grouped' ->
+            A = Avp#diameter_avp{name = AvpName,
+                                 value = V,
+                                 type = Type},
+            {A, pack_avp(Name, A, Opts, Acc)}
     catch
         throw: {?TAG, {grouped, Error, ComponentAvps}} ->
-            g(is_failed(), Error, Name, trim(Avp), Acc, ComponentAvps);
+            decode_error(Name,
+                         Error,
+                         ComponentAvps,
+                         Opts,
+                         Avp#diameter_avp{name = AvpName,
+                                          data = trim(Avp#diameter_avp.data),
+                                          type = Type},
+                         Acc);
+
         error: Reason ->
-            d(is_failed(), Reason, Name, trim(Avp), Acc)
-    after
-        reset(?STRICT_KEY, Strict),
-        reset(?FAILED_KEY, Failed)
+            decode_error(Name,
+                         Reason,
+                         Opts,
+                         Avp#diameter_avp{name = AvpName,
+                                          data = trim(Avp#diameter_avp.data),
+                                          type = Type},
+                         Acc)
     end.
 
 %% trim/1
@@ -407,123 +395,66 @@ trim(Avps)
 trim(Avp) ->
     Avp.
 
-%% dict/1
-%%
-%% Retrieve the dictionary for the best-effort decode of Failed-AVP,
-%% as put by diameter_codec:decode/2. See that function for the
-%% explanation.
-
-dict(true) ->
-    case get({diameter_codec, dictionary}) of
-        undefined ->
-            ?MODULE;
-        Mod ->
-            Mod
-    end;
-
-dict(_) ->
-    ?MODULE.
-
-%% g/5
-
-%% Ignore decode errors within Failed-AVP (best-effort) ...
-g(true, [_Error | Rec], Name, Avp, Acc, _ComponentAvps) ->
-    decode_AVP(Name, Avp#diameter_avp{value = Rec}, Acc);
-g(true, _Error, Name, Avp, Acc, _ComponentAvps) ->
-    decode_AVP(Name, Avp, Acc);
-
-%% ... or not.
-g(false, [Error | _Rec], _Name, Avp, Acc, ComponentAvps) ->
-    g(Error, Avp, Acc, ComponentAvps);
-g(false, Error, _Name, Avp, Acc, ComponentAvps) ->
-    g(Error, Avp, Acc, ComponentAvps).
-
-%% g/4
-
-g({RC, ErrorData}, Avp, Acc, ComponentAvps) ->
-    {Rec, Errors} = Acc,
-    E = Avp#diameter_avp{data = [ErrorData]},
-    {[Avp | trim(ComponentAvps)], {Rec, [{RC, E} | Errors]}}.
+%% decode_error/6
+
+decode_error(Name, [_ | Rec], _, #{failed_avp := true} = Opts, Avp, Acc) ->
+    decode_AVP(Name, Avp#diameter_avp{value = Rec}, Opts, Acc);
+
+decode_error(Name, _, _, #{failed_avp := true} = Opts, Avp, Acc) ->
+    decode_AVP(Name, Avp, Opts, Acc);
 
-%% d/5
+decode_error(_, [Error | _], ComponentAvps, _, Avp, Acc) ->
+    decode_error(Error, Avp, Acc, ComponentAvps);
 
-%% Ignore a decode error within Failed-AVP ...
-d(true, _, Name, Avp, Acc) ->
-    decode_AVP(Name, Avp, Acc);
+decode_error(_, Error, ComponentAvps, _, Avp, Acc) ->
+    decode_error(Error, Avp, Acc, ComponentAvps).
 
-%% ... or not. Failures here won't be visible since they're a "normal"
-%% occurrence if the peer sends a faulty AVP that we need to respond
-%% sensibly to. Log the occurence for traceability, but the peer will
-%% also receive info in the resulting answer message.
-d(false, Reason, Name, Avp, Acc) ->
+%% decode_error/5
+
+decode_error(Name, _Reason, #{failed_avp := true} = Opts, Avp, Acc) ->
+    decode_AVP(Name, Avp, Opts, Acc);
+
+decode_error(Name, Reason, _, Avp, {Rec, Failed}) ->
     Stack = diameter_lib:get_stacktrace(),
     diameter_lib:log(decode_error,
                      ?MODULE,
                      ?LINE,
                      {Name, Avp#diameter_avp.name, Stack}),
-    {Rec, Failed} = Acc,
     {Avp, {Rec, [rc(Reason, Avp) | Failed]}}.
 
-%% relax/2
-
-%% Set false in the process dictionary as soon as we see a Grouped AVP
-%% that doesn't set the M-bit, so that is_strict() can say whether or
-%% not to ignore the M-bit on an encapsulated AVP.
-relax('Grouped', M) ->
-    case getr(?STRICT_KEY) of
-        undefined when not M ->
-            putr(?STRICT_KEY, M);
-        _ ->
-            false
-    end;
-relax(_, _) ->
-    false.
-
-is_strict() ->
-    diameter_codec:getopt(strict_mbit)
-        andalso false /= getr(?STRICT_KEY).
-
-%% relax/1
-%%
-%% Set true in the process dictionary as soon as we see Failed-AVP.
-%% Matching on 'Failed-AVP' assumes that this is the RFC AVP.
-%% Strictly, this doesn't need to be the case.
-
-relax('Failed-AVP') ->
-    putr(?FAILED_KEY, true);
+%% decode_error/4
 
-relax(_) ->
-    is_failed().
-
-%% is_failed/0
-%%
-%% Is the AVP currently being decoded nested within Failed-AVP? Note
-%% that this is only true when Failed-AVP is the parent. In
-%% particular, it's not true when Failed-AVP itself is being decoded
-%% (unless nested).
-
-is_failed() ->
-    true == getr(?FAILED_KEY).
+decode_error({RC, ErrorData}, Avp, {Rec, Failed}, ComponentAvps) ->
+    E = Avp#diameter_avp{data = [ErrorData]},
+    {[Avp | trim(ComponentAvps)], {Rec, [{RC, E} | Failed]}}.
 
-%% is_failed/1
+%% set_strict/3
 
-is_failed(Name) ->
-    'Failed-AVP' == Name orelse is_failed().
+%% Set false as soon as we see a Grouped AVP that doesn't set the
+%% M-bit, to ignore the M-bit on an encapsulated AVP.
+set_strict('Grouped', false = M, #{strict_mbit := true} = Opts) ->
+    Opts#{strict_mbit := M};
+set_strict(_, _, Opts) ->
+    Opts.
 
-%% reset/2
+%% set_failed/2
+%%
+%% Set true as soon as we see Failed-AVP. Matching on 'Failed-AVP'
+%% assumes that this is the RFC AVP. Strictly, this doesn't need to be
+%% the case.
 
-reset(Key, undefined) ->
-    eraser(Key);
-reset(_, _) ->
-    ok.
+set_failed('Failed-AVP', #{failed_avp := false} = Opts) ->
+    Opts#{failed_avp := true};
+set_failed(_, Opts) ->
+    Opts.
 
-%% decode_AVP/3
+%% decode_AVP/4
 %%
 %% Don't know this AVP: see if it can be packed in an 'AVP' field
 %% undecoded. Note that the type field is 'undefined' in this case.
 
-decode_AVP(Name, Avp, Acc) ->
-    {trim(Avp), pack_AVP(Name, Avp, Acc)}.
+decode_AVP(Name, Avp, Opts, Acc) ->
+    {trim(Avp), pack_AVP(Name, Avp, Opts, Acc)}.
 
 %% rc/1
 
@@ -543,37 +474,20 @@ rc({'DIAMETER', 5014 = RC, _}, #diameter_avp{name = AvpName} = Avp) ->
 rc(_, Avp) ->
     {5004, Avp}.
 
-%% ungroup/2
-
--spec ungroup(term(), #diameter_avp{})
-   -> {avp(), #diameter_avp{}}.
-
-%% The decoded value in the Grouped case is as returned by grouped_avp/3:
-%% a record and a list of component AVP's.
-ungroup(V, #diameter_avp{type = 'Grouped'} = Avp) ->
-    {Rec, As} = V,
-    A = Avp#diameter_avp{value = Rec},
-    {[A|As], A};
-
-%% Otherwise it's just a plain value.
-ungroup(V, #diameter_avp{} = Avp) ->
-    A = Avp#diameter_avp{value = V},
-    {A, A}.
-
-%% pack_avp/3
+%% pack_avp/4
 
-pack_avp(Name, #diameter_avp{name = AvpName} = Avp, Acc) ->
-    pack_avp(Name, avp_arity(Name, AvpName), Avp, Acc).
+pack_avp(Name, #diameter_avp{name = AvpName} = Avp, Opts, Acc) ->
+    pack_avp(Name, avp_arity(Name, AvpName), Avp, Opts, Acc).
 
-%% pack_avp/4
+%% pack_avp/5
 
-pack_avp(Name, 0, Avp, Acc) ->
-    pack_AVP(Name, Avp, Acc);
+pack_avp(Name, 0, Avp, Opts, Acc) ->
+    pack_AVP(Name, Avp, Opts, Acc);
 
-pack_avp(_, Arity, Avp, Acc) ->
-    pack(Arity, Avp#diameter_avp.name, Avp, Acc).
+pack_avp(_, Arity, #diameter_avp{name = AvpName} = Avp, _, Acc) ->
+    pack(Arity, AvpName, Avp, Acc).
 
-%% pack_AVP/3
+%% pack_AVP/4
 
 %% Length failure was induced because of a header/payload length
 %% mismatch. The AVP Length is reset to match the received data if
@@ -588,44 +502,47 @@ pack_avp(_, Arity, Avp, Acc) ->
 %% payload for the AVP's type, but in this case we don't know the
 %% type.
 
-pack_AVP(_, #diameter_avp{data = {5014 = RC, Data}} = Avp, Acc) ->
+pack_AVP(_, #diameter_avp{data = {5014 = RC, Data}} = Avp, _, Acc) ->
     {Rec, Failed} = Acc,
     {Rec, [{RC, Avp#diameter_avp{data = Data}} | Failed]};
 
-pack_AVP(Name, #diameter_avp{is_mandatory = M, name = AvpName} = Avp, Acc) ->
-    case pack_arity(Name, AvpName, M) of
-        0 ->
-            {Rec, Failed} = Acc,
-            {Rec, [{if M -> 5001; true -> 5008 end, Avp} | Failed]};
-        Arity ->
-            pack(Arity, 'AVP', Avp, Acc)
-    end.
+pack_AVP(Name, Avp, Opts, Acc) ->
+    pack_AVP(pack_arity(Name, Opts, Avp), Avp, Acc).
+
+%% pack_AVP/3
+
+pack_AVP(0, #diameter_avp{is_mandatory = M} = Avp, Acc) ->
+    {Rec, Failed} = Acc,
+    {Rec, [{if M -> 5001; true -> 5008 end, Avp} | Failed]};
+
+pack_AVP(Arity, Avp, Acc) ->
+    pack(Arity, 'AVP', Avp, Acc).
 
 %% Give Failed-AVP special treatment since (1) it'll contain any
 %% unrecognized mandatory AVP's and (2) the RFC 3588 grammar failed to
 %% allow for Failed-AVP in an answer-message.
 
-pack_arity(Name, AvpName, M) ->
+pack_arity(Name,
+           #{strict_mbit := Strict,
+             failed_avp := Failed},
+           #diameter_avp{is_mandatory = M,
+                         name = AvpName}) ->
 
     %% Not testing just Name /= 'Failed-AVP' means we're changing the
     %% packing of AVPs nested within Failed-AVP, but the point of
     %% ignoring errors within Failed-AVP is to decode as much as
     %% possible, and failing because a mandatory AVP couldn't be
-    %% packed into a dedicated field defeats that point. Note
-    %% is_failed/1 since is_failed/0 will return false when packing
-    %% 'AVP' within Failed-AVP.
-
-    pack_arity(is_failed(Name)
-                 orelse {Name, AvpName} == {'answer-message', 'Failed-AVP'}
-                 orelse not M
-                 orelse not is_strict(),
-               Name).
-
-pack_arity(true, Name) ->
-    avp_arity(Name, 'AVP');
-
-pack_arity(false, _) ->
-    0.
+    %% packed into a dedicated field defeats that point.
+
+    if Failed == true;
+       Name == 'Failed-AVP';
+       Name == 'answer-message', AvpName == 'Failed-AVP';
+       not M;
+       not Strict ->
+            avp_arity(Name, 'AVP');
+       true ->
+            0
+    end.
 
 %% 3588:
 %%
@@ -679,9 +596,9 @@ pack(L, {_, Max}, F, Avp, {Rec, Failed}) ->
 %% # grouped_avp/3
 %% ---------------------------------------------------------------------------
 
--spec grouped_avp(decode, avp_name(), binary() | {5014, binary()})
+-spec grouped_avp(decode, avp_name(), binary() | {5014, binary()}, term())
    -> {avp_record(), [avp()]};
-                 (encode, avp_name(), avp_record() | avp_values())
+                 (encode, avp_name(), avp_record() | avp_values(), term())
    -> iolist()
     | no_return().
 
@@ -689,14 +606,14 @@ pack(L, {_, Max}, F, Avp, {Rec, Failed}) ->
 %% length in the header was too short (insufficient for the extracted
 %% header) or too long (past the end of the message). An empty payload
 %% is sufficient according to the RFC text for 5014.
-grouped_avp(decode, _Name, {5014 = RC, _Bin}) ->
+grouped_avp(decode, _Name, {5014 = RC, _Bin}, _) ->
     throw({?TAG, {grouped, {RC, []}, []}});
 
-grouped_avp(decode, Name, Data) ->
-    grouped_decode(Name, diameter_codec:collect_avps(Data));
+grouped_avp(decode, Name, Data, Opts) ->
+    grouped_decode(Name, diameter_codec:collect_avps(Data), Opts);
 
-grouped_avp(encode, Name, Data) ->
-    encode_avps(Name, Data).
+grouped_avp(encode, Name, Data, Opts) ->
+    encode_avps(Name, Data, Opts).
 
 %% grouped_decode/2
 %%
@@ -705,7 +622,7 @@ grouped_avp(encode, Name, Data) ->
 %% records.
 
 %% Length error in trailing component AVP.
-grouped_decode(_Name, {Error, Acc}) ->
+grouped_decode(_Name, {Error, Acc}, _) ->
     {5014, Avp} = Error,
     throw({?TAG, {grouped, Error, [Avp | Acc]}});
 
@@ -723,8 +640,8 @@ grouped_decode(_Name, {Error, Acc}) ->
 %% component, which the catch in d/3 wraps in the Grouped AVP in
 %% question. A partially decoded record is only used when ignoring
 %% errors in Failed-AVP.
-grouped_decode(Name, ComponentAvps) ->
-    {Rec, Avps, Es} = decode_avps(Name, ComponentAvps),
+grouped_decode(Name, ComponentAvps, Opts) ->
+    {Rec, Avps, Es} = decode_avps(Name, ComponentAvps, Opts),
     [] == Es orelse throw({?TAG, {grouped, [{_,_} = hd(Es) | Rec], Avps}}),
     {Rec, Avps}.
 
@@ -745,7 +662,7 @@ z(Name, {Min, _}) ->
 z('AVP') ->
     <<0:64>>;  %% minimal header
 z(Name) ->
-    Bin = diameter_codec:pack_avp(avp_header(Name), empty_value(Name)),
+    Bin = diameter_codec:pack_data(avp_header(Name), empty_value(Name)),
     Sz = iolist_size(Bin),
     <<0:Sz/unit:8>>.
 
@@ -754,4 +671,4 @@ z(Name) ->
 %% ---------------------------------------------------------------------------
 
 empty(AvpName) ->
-    avp(encode, zero, AvpName).
+    avp(encode, zero, AvpName, _Opts = []).
diff --git a/lib/diameter/src/base/diameter_codec.erl b/lib/diameter/src/base/diameter_codec.erl
index 789395abe9..52eb10b8c2 100644
--- a/lib/diameter/src/base/diameter_codec.erl
+++ b/lib/diameter/src/base/diameter_codec.erl
@@ -21,10 +21,8 @@
 -module(diameter_codec).
 
 -export([encode/2,
-         decode/2,
          decode/3,
-         setopts/1,
-         getopt/1,
+         decode/4,
          collect_avps/1,
          decode_header/1,
          sequence_numbers/1,
@@ -33,7 +31,7 @@
          msg_id/1]).
 
 %% Towards generated encoders (from diameter_gen.hrl).
--export([pack_avp/1,
+-export([pack_data/2,
          pack_avp/2]).
 
 -include_lib("diameter/include/diameter.hrl").
@@ -66,52 +64,6 @@
 %%    +-+-+-+-+-+-+-+-+-+-+-+-+-
 
 %%% ---------------------------------------------------------------------------
-%%% # setopts/1
-%%% # getopt/1
-%%% ---------------------------------------------------------------------------
-
-%% These functions are a compromise in the same vein as the use of the
-%% process dictionary in diameter_gen.hrl in generated codec modules.
-%% Instead of rewriting the entire dictionary generation to pass
-%% encode/decode options around, the calling process sets them by
-%% calling setopts/1. At current, the only option is whether or not to
-%% decode binaries as strings, which is used by diameter_types.
-
-setopts(Opts)
-  when is_list(Opts) ->
-    lists:foreach(fun setopt/1, Opts).
-
-%% The default string_decode true is for backwards compatibility.
-setopt({K, false = B})
-  when K == string_decode;
-       K == strict_mbit ->
-    setopt(K, B);
-
-%% Regard anything but the generated RFC 3588 dictionary as modern.
-%% This affects the interpretation of defaults during the decode
-%% of values of type DiameterURI, this having changed from RFC 3588.
-%% (So much for backwards compatibility.)
-setopt({common_dictionary, diameter_gen_base_rfc3588}) ->
-    setopt(rfc, 3588);
-
-setopt(_) ->
-    ok.
-
-setopt(Key, Value) ->
-    put({diameter, Key}, Value).
-
-getopt(Key) ->
-    case get({diameter, Key}) of
-        undefined when Key == string_decode;
-                       Key == strict_mbit ->
-            true;
-        undefined when Key == rfc ->
-            6733;
-        V ->
-            V
-    end.
-
-%%% ---------------------------------------------------------------------------
 %%% # encode/2
 %%% ---------------------------------------------------------------------------
 
@@ -121,7 +73,7 @@ getopt(Key) ->
 
 encode(Mod, #diameter_packet{} = Pkt) ->
     try
-        e(Mod, Pkt)
+        encode(Mod, _Opts = [], Pkt)
     catch
         exit: {Reason, Stack, #diameter_header{} = H} = T ->
             %% Exit with a header in the reason to let the caller
@@ -139,11 +91,14 @@ encode(Mod, Msg) ->
     Hdr = #diameter_header{version = ?DIAMETER_VERSION,
                            end_to_end_id = Seq,
                            hop_by_hop_id = Seq},
-    encode(Mod,  #diameter_packet{header = Hdr,
-                                  msg = Msg}).
+    encode(Mod, #diameter_packet{header = Hdr,
+                                 msg = Msg}).
 
-e(_, #diameter_packet{msg = [#diameter_header{} = Hdr | As]} = Pkt) ->
-    try encode_avps(reorder(As)) of
+%% encode/3
+
+encode(_, Opts, #diameter_packet{msg = [#diameter_header{} = Hdr | As]}
+                = Pkt) ->
+    try encode_avps(reorder(As), Opts) of
         Avps ->
             Bin = list_to_binary(Avps),
             Len = 20 + size(Bin),
@@ -171,7 +126,7 @@ e(_, #diameter_packet{msg = [#diameter_header{} = Hdr | As]} = Pkt) ->
             exit({Reason, diameter_lib:get_stacktrace(), Hdr})
     end;
 
-e(Mod, #diameter_packet{header = Hdr0, msg = Msg} = Pkt) ->
+encode(Mod, Opts, #diameter_packet{header = Hdr0, msg = Msg} = Pkt) ->
     MsgName = rec2msg(Mod, Msg),
     {Code, Flags, Aid} = msg_header(Mod, MsgName, Hdr0),
 
@@ -191,7 +146,7 @@ e(Mod, #diameter_packet{header = Hdr0, msg = Msg} = Pkt) ->
 
     Values = values(Msg),
 
-    try encode_avps(Mod, MsgName, Values) of
+    try encode_avps(Mod, MsgName, Values, Opts) of
         Avps ->
             Bin = list_to_binary(Avps),
             Len = 20 + size(Bin),
@@ -230,7 +185,7 @@ values([H|T])
 values(Avps) ->
     Avps.
 
-%% encode_avps/3
+%% encode_avps/4
 
 %% Specifying values as a #diameter_avp list bypasses arity and other
 %% checks: the values are expected to be already encoded and the AVP's
@@ -238,12 +193,12 @@ values(Avps) ->
 %% these have to be able to resend whatever comes.
 
 %% Message as a list of #diameter_avp{} ...
-encode_avps(_, _, [#diameter_avp{} | _] = Avps) ->
-    encode_avps(reorder(Avps));
+encode_avps(_, _, [#diameter_avp{} | _] = Avps, Opts) ->
+    encode_avps(reorder(Avps), Opts);
 
 %% ... or as a tuple list or record.
-encode_avps(Mod, MsgName, Values) ->
-    Mod:encode_avps(MsgName, Values).
+encode_avps(Mod, MsgName, Values, Opts) ->
+    Mod:encode_avps(MsgName, Values, Opts).
 
 %% reorder/1
 %%
@@ -284,10 +239,10 @@ reorder([H | T], Acc) ->
 reorder([], _) ->
     false.
 
-%% encode_avps/1
+%% encode_avps/2
 
-encode_avps(Avps) ->
-    lists:map(fun pack_avp/1, Avps).
+encode_avps(Avps, Opts) ->
+    [pack_avp(A, Opts) || A <- Avps].
 
 %% msg_header/3
 
@@ -312,41 +267,39 @@ rec2msg(Mod, Rec) ->
     Mod:rec2msg(element(1, Rec)).
 
 %%% ---------------------------------------------------------------------------
-%%% # decode/2
+%%% # decode/3
 %%% ---------------------------------------------------------------------------
 
 %% Unsuccessfully decoded AVPs will be placed in #diameter_packet.errors.
 
--spec decode(module() | {module(), module()}, #diameter_packet{} | binary())
+-spec decode(module() | {module(), module()},
+             map(),
+             #diameter_packet{} | binary())
    -> #diameter_packet{}.
 
 %% An Answer setting the E-bit. The application dictionary is needed
-%% for the best-effort decode of Failed-AVP, and the best way to make
-%% this available to the AVP decode in diameter_gen.hrl, without
-%% having to rewrite the entire codec generation, is to place it in
-%% the process dictionary. It's the code in diameter_gen.hrl (that's
-%% included by every generated codec module) that looks for the entry.
-%% Not ideal, but it solves the problem relatively simply.
-decode({Mod, Mod}, Pkt) ->
-    decode(Mod, Pkt);
-decode({Mod, AppMod}, Pkt) ->
-    Key = {?MODULE, dictionary},
-    put(Key, AppMod),
-    try
-        decode(Mod, Pkt)
-    after
-        erase(Key)
-    end;
+%% for the best-effort decode of Failed-AVP.
+decode({Mod, AppMod}, Opts, Pkt) ->
+    decode(Mod, AppMod, Opts, Pkt);
 
 %% Or not: a request, or an answer not setting the E-bit.
-decode(Mod, Pkt) ->
-    decode(Mod:id(), Mod, Pkt).
+decode(Mod, Opts, Pkt) ->
+    decode(Mod, Mod, Opts, Pkt).
+
+%% decode/4
 
-%% decode/3
+decode(Id, Mod, Opts, Pkt)
+  when is_integer(Id) ->
+    decode(Id, Mod, Mod, Opts, Pkt);
+
+decode(Mod, AppMod, Opts, Pkt) ->
+    decode(Mod:id(), Mod, AppMod, Opts, Pkt).
+
+%% decode/5
 
 %% Relay application: just extract the avp's without any decoding of
 %% their data since we don't know the application in question.
-decode(?APP_ID_RELAY, _, #diameter_packet{} = Pkt) ->
+decode(?APP_ID_RELAY, _, _, _, #diameter_packet{} = Pkt) ->
     case collect_avps(Pkt) of
         {E, As} ->
             Pkt#diameter_packet{avps = As,
@@ -356,7 +309,7 @@ decode(?APP_ID_RELAY, _, #diameter_packet{} = Pkt) ->
     end;
 
 %% Otherwise decode using the dictionary.
-decode(_, Mod, #diameter_packet{header = Hdr} = Pkt) ->
+decode(_, Mod, AppMod, Opts, #diameter_packet{header = Hdr} = Pkt) ->
     #diameter_header{cmd_code = CmdCode,
                      is_request = IsRequest,
                      is_error = IsError}
@@ -368,29 +321,33 @@ decode(_, Mod, #diameter_packet{header = Hdr} = Pkt) ->
                       Mod:msg_name(CmdCode, IsRequest)
               end,
 
-    decode_avps(MsgName, Mod, Pkt, collect_avps(Pkt));
+    decode_avps(MsgName, Mod, AppMod, Opts, Pkt, collect_avps(Pkt));
 
-decode(Id, Mod, Bin)
+decode(Id, Mod, AppMod, Opts, Bin)
   when is_binary(Bin) ->
-    decode(Id, Mod, #diameter_packet{header = decode_header(Bin), bin = Bin}).
+    decode(Id, Mod, AppMod, Opts, #diameter_packet{header = decode_header(Bin),
+                                                   bin = Bin}).
 
-%% decode_avps/4
+%% decode_avps/6
 
-decode_avps(MsgName, Mod, Pkt, {E, Avps}) ->
+decode_avps(MsgName, Mod, AppMod, Opts, Pkt, {E, Avps}) ->
     ?LOG(invalid_avp_length, Pkt#diameter_packet.header),
     #diameter_packet{errors = Failed}
         = P
-        = decode_avps(MsgName, Mod, Pkt, Avps),
+        = decode_avps(MsgName, Mod, AppMod, Opts, Pkt, Avps),
     P#diameter_packet{errors = [E | Failed]};
 
-decode_avps('', _, Pkt, Avps) ->  %% unknown message ...
+decode_avps('', _, _, _, Pkt, Avps) ->  %% unknown message ...
     ?LOG(unknown_message, Pkt#diameter_packet.header),
     Pkt#diameter_packet{avps = lists:reverse(Avps),
                         errors = [3001]};   %% DIAMETER_COMMAND_UNSUPPORTED
 %% msg = undefined identifies this case.
 
-decode_avps(MsgName, Mod, Pkt, Avps) ->  %% ... or not
-    {Rec, As, Errors} = Mod:decode_avps(MsgName, Avps),
+decode_avps(MsgName, Mod, AppMod, Opts, Pkt, Avps) ->  %% ... or not
+    {Rec, As, Errors} = Mod:decode_avps(MsgName,
+                                        Avps,
+                                        Opts#{dictionary => AppMod,
+                                              failed_avp => false}),
     ?LOGC([] /= Errors, decode_errors, Pkt#diameter_packet.header),
     Pkt#diameter_packet{msg = Rec,
                         errors = Errors,
@@ -655,7 +612,7 @@ collect_avps(Code, VendorId, M, P, Len, Pad, Rest, N, Acc) ->
 %% (2) the last sentence covers this case.
 
 %%% ---------------------------------------------------------------------------
-%%% # pack_avp/1
+%%% # pack_avp/2
 %%% ---------------------------------------------------------------------------
 
 %% The normal case here is data as an #diameter_avp{} list or an
@@ -665,34 +622,36 @@ collect_avps(Code, VendorId, M, P, Len, Pad, Rest, N, Acc) ->
 
 %% Decoded Grouped AVP with decoded components: ignore components
 %% since they're already encoded in the Grouped AVP.
-pack_avp([#diameter_avp{} = Grouped | _Components]) ->
-    pack_avp(Grouped);
+pack_avp([#diameter_avp{} = Grouped | _Components], Opts) ->
+    pack_avp(Grouped, Opts);
 
 %% Grouped AVP whose components need packing. It's intentional that
 %% this isn't equivalent to [Grouped | Components]: here the
 %% components need to be encoded before wrapping with the Grouped AVP,
 %% and the list is flat, nesting being accomplished in the data
 %% fields.
-pack_avp(#diameter_avp{data = [#diameter_avp{} | _] = Components} = Grouped) ->
-    pack_data(encode_avps(Components), Grouped);
+pack_avp(#diameter_avp{data = [#diameter_avp{} | _] = Components}
+         = Grouped,
+         Opts) ->
+    pack_data(Grouped, encode_avps(Components, Opts));
 
 %% Data as a type/value tuple ...
-pack_avp(#diameter_avp{data = {Type, Value}} = A)
+pack_avp(#diameter_avp{data = {Type, Value}} = A, Opts)
   when is_atom(Type) ->
-    pack_data(diameter_types:Type(encode, Value), A);
+    pack_data(A, diameter_types:Type(encode, Value, Opts));
 
 %% ... with a header in various forms ...
-pack_avp(#diameter_avp{data = {T, {Type, Value}}}) ->
-    pack_avp(T, diameter_types:Type(encode, Value));
+pack_avp(#diameter_avp{data = {T, {Type, Value}}}, Opts) ->
+    pack_data(T, diameter_types:Type(encode, Value, Opts));
 
-pack_avp(#diameter_avp{data = {T, Data}}) ->
-    pack_avp(T, Data);
+pack_avp(#diameter_avp{data = {T, Data}}, _) ->
+    pack_data(T, Data);
 
-pack_avp(#diameter_avp{data = {Dict, Name, Data}}) ->
-    pack_avp(Dict:avp_header(Name), Dict:avp(encode, Data, Name));
+pack_avp(#diameter_avp{data = {Dict, Name, Data}}, Opts) ->
+    pack_data(Dict:avp_header(Name), Dict:avp(encode, Data, Name, Opts));
 
 %% ... with a truncated header ...
-pack_avp(#diameter_avp{code = undefined, data = B})
+pack_avp(#diameter_avp{code = undefined, data = B}, _)
   when is_binary(B) ->
     %% Reset the AVP Length of an AVP Header resulting from a 5014
     %% error. The RFC doesn't explicitly say to do this but the
@@ -706,54 +665,53 @@ pack_avp(#diameter_avp{code = undefined, data = B})
     <<B:Sz/binary, 0:(5-Sz)/unit:8, Len:24, 0:(Len-8)/unit:8>>;
 
 %% Ignoring errors in Failed-AVP or during a relay encode.
-pack_avp(#diameter_avp{data = {5014, Data}} = A) ->
-    pack_data(Data, A);
+pack_avp(#diameter_avp{data = {5014, Data}} = A, _) ->
+    pack_data(A, Data);
 
-pack_avp(#diameter_avp{data = Data} = A) ->
-    pack_data(Data, A).
+pack_avp(#diameter_avp{data = Data} = A, _) ->
+    pack_data(A, Data).
 
 header_length(<<_:32, 1:1, _/bits>>) ->
     12;
 header_length(_) ->
     8.
 
-%% pack_data/2
+%%% ---------------------------------------------------------------------------
+%%% # pack_data/2
+%%% ---------------------------------------------------------------------------
 
-pack_data(Data, #diameter_avp{code = Code,
-                              vendor_id = V,
-                              is_mandatory = M,
-                              need_encryption = P}) ->
+pack_data(#diameter_avp{code = Code,
+                        vendor_id = V,
+                        is_mandatory = M,
+                        need_encryption = P},
+          Data) ->
     Flags = ?BIT(V /= undefined, 2#10000000)
         bor ?BIT(M, 2#01000000)
         bor ?BIT(P, 2#00100000),
-    pack_avp(Code, Flags, V, Data).
-
-%%% ---------------------------------------------------------------------------
-%%% # pack_avp/2
-%%% ---------------------------------------------------------------------------
+    pack(Code, Flags, V, Data);
 
-pack_avp({Code, Flags, VendorId}, Data) ->
-    pack_avp(Code, Flags, VendorId, Data).
+pack_data({Code, Flags, VendorId}, Data) ->
+    pack(Code, Flags, VendorId, Data).
 
-%% pack_avp/4
+%% pack/4
 
-pack_avp(Code, Flags, VendorId, Data) ->
+pack(Code, Flags, VendorId, Data) ->
     Sz = iolist_size(Data),
-    pack_avp(Code, Flags, Sz, VendorId, Data, ?PAD(Sz)).
+    pack(Code, Flags, Sz, VendorId, Data, ?PAD(Sz)).
 %% Padding is not included in the length field, as mandated by the RFC.
 
-%% pack_avp/6
+%% pack/6
 %%
 %% Prepend the vendor id as required.
 
-pack_avp(Code, Flags, Sz, _Vid, Data, Pad) 
+pack(Code, Flags, Sz, _Vid, Data, Pad)
   when 0 == Flags band 2#10000000 ->
-    pack_avp(Code, Flags, Sz, 0, 0, Data, Pad);
+    pack(Code, Flags, Sz, 0, 0, Data, Pad);
 
-pack_avp(Code, Flags, Sz, Vid, Data, Pad) ->
-    pack_avp(Code, Flags, Sz+4, Vid, 1, Data, Pad).
+pack(Code, Flags, Sz, Vid, Data, Pad) ->
+    pack(Code, Flags, Sz+4, Vid, 1, Data, Pad).
 
-%% pack_avp/7
+%% pack/7
 
-pack_avp(Code, Flags, Sz, VId, V, Data, Pad) ->
+pack(Code, Flags, Sz, VId, V, Data, Pad) ->
     [<<Code:32, Flags:8, (8+Sz):24, VId:V/unit:32>>, Data, <<0:Pad/unit:8>>].
diff --git a/lib/diameter/src/base/diameter_config.erl b/lib/diameter/src/base/diameter_config.erl
index 38781d5c23..1db9b52dfa 100644
--- a/lib/diameter/src/base/diameter_config.erl
+++ b/lib/diameter/src/base/diameter_config.erl
@@ -535,12 +535,12 @@ stop(SvcName) ->
 %% restrict applications so that that there's one while the service
 %% has many.
 
-add(SvcName, Type, Opts) ->
+add(SvcName, Type, Opts0) ->
     %% Ensure acceptable transport options. This won't catch all
     %% possible errors (faulty callbacks for example) but it catches
     %% many. diameter_service:merge_service/2 depends on usable
     %% capabilities for example.
-    ok = transport_opts(Opts),
+    Opts = transport_opts(Opts0),
 
     Ref = make_ref(),
     true = diameter_reg:add_new(?TRANSPORT_KEY(Ref)),
@@ -560,7 +560,17 @@ add(SvcName, Type, Opts) ->
     end.
 
 transport_opts(Opts) ->
-    lists:foreach(fun(T) -> opt(T) orelse ?THROW({invalid, T}) end, Opts).
+    lists:map(fun topt/1, Opts).
+
+topt(T) ->
+    case opt(T) of
+        {value, X} ->
+            X;
+        true ->
+            T;
+        false ->
+            ?THROW({invalid, T})
+    end.
 
 opt({transport_module, M}) ->
     is_atom(M);
@@ -600,8 +610,12 @@ opt({watchdog_timer, Tmo}) ->
 opt({watchdog_config, L}) ->
     is_list(L) andalso lists:all(fun wdopt/1, L);
 
-opt({spawn_opt, Opts}) ->
-    is_list(Opts);
+opt({spawn_opt = K, Opts}) ->
+    if is_list(Opts) ->
+            {value, {K, spawn_opts(Opts)}};
+       true ->
+            false
+    end;
 
 opt({pool_size, N}) ->
     is_integer(N) andalso 0 < N;
@@ -727,7 +741,7 @@ opt(incoming_maxlen, N)
 
 opt(spawn_opt, L)
   when is_list(L) ->
-    L;
+    spawn_opts(L);
 
 opt(K, false = B)
   when K == share_peers;
@@ -789,6 +803,9 @@ opt(sequence = K, F) ->
 opt(K, _) ->
     ?THROW({value, K}).
 
+spawn_opts(L) ->
+    [T || T <- L, T /= link, T /= monitor].
+
 sequence({H,N} = T)
   when 0 =< N, N =< 32, 0 =< H, 0 == H bsr (32-N) ->
     T;
diff --git a/lib/diameter/src/base/diameter_peer_fsm.erl b/lib/diameter/src/base/diameter_peer_fsm.erl
index 2383d830e6..e0bcc565e7 100644
--- a/lib/diameter/src/base/diameter_peer_fsm.erl
+++ b/lib/diameter/src/base/diameter_peer_fsm.erl
@@ -128,6 +128,9 @@
                        %% outgoing DPR; boolean says whether or not
                        %% the request was sent explicitly with
                        %% diameter:call/4.
+         codec :: #{string_decode := boolean(),
+                    strict_mbit := boolean(),
+                    rfc := 3588 | 6733},
          strict :: boolean(),
          ack = false :: boolean(),
          length_errors :: exit | handle | discard,
@@ -160,10 +163,7 @@
 %% # start/3
 %% ---------------------------------------------------------------------------
 
--spec start(T, [Opt], {[diameter:service_opt()],
-                       [node()],
-                       module(),
-                       #diameter_service{}})
+-spec start(T, [Opt], {map(), [node()], module(), #diameter_service{}})
    -> {reference(), pid()}
  when T   :: {connect|accept, diameter:transport_ref()},
       Opt :: diameter:transport_opt().
@@ -222,9 +222,10 @@ i({Ack, WPid, {M, Ref} = T, Opts, {SvcOpts, Nodes, Dict0, Svc}}) ->
     erlang:monitor(process, WPid),
     wait(Ack, WPid),
     diameter_stats:reg(Ref),
-    diameter_codec:setopts([{common_dictionary, Dict0} | SvcOpts]),
-    {_,_} = Mask = proplists:get_value(sequence, SvcOpts),
-    Maxlen = proplists:get_value(incoming_maxlen, SvcOpts, 16#FFFFFF),
+
+    #{sequence := Mask, incoming_maxlen := Maxlen}
+        = SvcOpts,
+
     {[Cs,Ds], Rest} = proplists:split(Opts, [capabilities_cb, disconnect_cb]),
     putr(?CB_KEY, {Ref, [F || {_,F} <- Cs]}),
     putr(?DPR_KEY, [F || {_, F} <- Ds]),
@@ -250,7 +251,8 @@ i({Ack, WPid, {M, Ref} = T, Opts, {SvcOpts, Nodes, Dict0, Svc}}) ->
            service = svc(Svc, Addrs),
            length_errors = LengthErr,
            strict = Strictness,
-           incoming_maxlen = Maxlen}.
+           incoming_maxlen = Maxlen,
+           codec = maps:with([string_decode, strict_mbit, rfc], SvcOpts)}.
 %% The transport returns its local ip addresses so that different
 %% transports on the same service can use different local addresses.
 %% The local addresses are put into Host-IP-Address avps here when
@@ -797,14 +799,15 @@ rcv('DPA' = N,
     = Pkt,
     #state{dictionary = Dict0,
            transport = TPid,
-           dpr = {X, Hid, Eid}}) ->
+           dpr = {X, Hid, Eid},
+           codec = Opts}) ->
     ?LOG(recv, N),
     X orelse begin
                  %% Only count DPA in response to a DPR sent by the
                  %% service: explicit DPR is counted in the same way
                  %% as other explicitly sent requests.
                  incr(recv, H, Dict0),
-                 incr_rc(recv, diameter_codec:decode(Dict0, Pkt), Dict0)
+                 incr_rc(recv, diameter_codec:decode(Dict0, Opts, Pkt), Dict0)
              end,
     diameter_peer:close(TPid),
     {stop, N};
@@ -901,11 +904,14 @@ header(Bin) ->  %% DWR
 %% Incoming CER or DPR.
 
 handle_request(Name,
-               #diameter_packet{header = H} = Pkt,
-               #state{dictionary = Dict0} = S) ->
+               #diameter_packet{header = H}
+               = Pkt,
+               #state{dictionary = Dict0,
+                      codec = Opts}
+               = S) ->
     ?LOG(recv, Name),
     incr(recv, H, Dict0),
-    send_answer(Name, diameter_codec:decode(Dict0, Pkt), S).
+    send_answer(Name, diameter_codec:decode(Dict0, Opts, Pkt), S).
 
 %% send_answer/3
 
@@ -955,8 +961,6 @@ build_answer('CER',
              = Pkt,
              #state{dictionary = Dict0}
              = S) ->
-    diameter_codec:setopts([{string_decode, false}]),
-
     {SupportedApps, RCaps, CEA} = recv_CER(CER, S),
 
     [RC, IS] = Dict0:'#get-'(['Result-Code', 'Inband-Security-Id'], CEA),
@@ -1157,18 +1161,16 @@ recv_CER(CER, #state{service = Svc, dictionary = Dict}) ->
 handle_CEA(#diameter_packet{header = H}
            = Pkt,
            #state{dictionary = Dict0,
-                  service = #diameter_service{capabilities = LCaps}}
+                  service = #diameter_service{capabilities = LCaps},
+                  codec = Opts}
            = S) ->
     incr(recv, H, Dict0),
 
     #diameter_packet{}
         = DPkt
-        = diameter_codec:decode(Dict0, Pkt),
-
-    diameter_codec:setopts([{string_decode, false}]),
+        = diameter_codec:decode(Dict0, Opts, Pkt),
 
     RC = result_code(incr_rc(recv, DPkt, Dict0)),
-
     {SApps, IS, RCaps} = recv_CEA(DPkt, S),
 
     #diameter_caps{origin_host = {OH, DH}}
diff --git a/lib/diameter/src/base/diameter_service.erl b/lib/diameter/src/base/diameter_service.erl
index d6fe8d7e05..78bc5afdf1 100644
--- a/lib/diameter/src/base/diameter_service.erl
+++ b/lib/diameter/src/base/diameter_service.erl
@@ -88,12 +88,6 @@
 %% outside of the service process.
 -define(STATE_TABLE, ?MODULE).
 
-%% The default sequence mask.
--define(NOMASK, {0,32}).
-
-%% The default restrict_connections.
--define(RESTRICT, nodes).
-
 %% Workaround for dialyzer's lack of understanding of match specs.
 -type match(T)
    :: T | '_' | '$1' | '$2'.
@@ -113,15 +107,14 @@
          local  :: {ets:tid(), ets:tid(), ets:tid()},
          remote :: {ets:tid(), ets:tid(), ets:tid()},
          monitor = false :: false | pid(),   %% process to die with
-         options
-         :: [{sequence, diameter:sequence()}  %% sequence mask
-             | {share_peers, diameter:remotes()}       %% broadcast to
-             | {use_shared_peers, diameter:remotes()}  %% use from
-             | {restrict_connections, diameter:restriction()}
-             | {strict_mbit, boolean()}
-             | {string_decode, boolean()}
-             | {incoming_maxlen, diameter:message_length()}]}).
-%% shared_peers reflects the peers broadcast from remote nodes.
+         options :: #{sequence := diameter:sequence(),  %% sequence mask
+                      share_peers := diameter:remotes(),%% broadcast to
+                      use_shared_peers := diameter:remotes(),%% use from
+                      restrict_connections := diameter:restriction(),
+                      incoming_maxlen := diameter:message_length(),
+                      strict_mbit := boolean(),
+                      string_decode := boolean(),
+                      spawn_opt := list()}}).
 
 %% Record representing an RFC 3539 watchdog process implemented by
 %% diameter_watchdog.
@@ -281,7 +274,7 @@ whois(SvcName) ->
 %% ---------------------------------------------------------------------------
 
 -spec pick_peer(SvcName, AppOrAlias, Opts)
-   -> {{TPid, Caps, App}, Mask, SvcOpts}
+   -> {{TPid, Caps, App}, SvcOpts}
     | false  %% no selection
     | {error, no_service}
  when SvcName :: diameter:service_name(),
@@ -293,10 +286,7 @@ whois(SvcName) ->
       TPid :: pid(),
       Caps :: #diameter_caps{},
       App  :: #diameter_app{},
-      Mask :: diameter:sequence(),
-      SvcOpts :: [diameter:service_opt()].
-%% Extract Mask in the returned tuple so that diameter_traffic doesn't
-%% need to know about the ordering of SvcOpts used here.
+      SvcOpts :: map().
 
 pick_peer(SvcName, App, Opts) ->
     pick(lookup_state(SvcName), App, Opts).
@@ -316,7 +306,7 @@ pick(#state{service = #diameter_service{applications = Apps}}
 pick(_, false = No, _) ->
     No;
 
-pick(#state{options = [{_, Mask} | SvcOpts]}
+pick(#state{options = SvcOpts}
      = S,
      #diameter_app{module = ModX, dictionary = Dict}
      = App0,
@@ -325,7 +315,7 @@ pick(#state{options = [{_, Mask} | SvcOpts]}
     [_,_] = RealmAndHost = diameter_lib:eval([DestF, Dict]),
     case pick_peer(App, RealmAndHost, Filter, S) of
         {TPid, Caps} ->
-            {{TPid, Caps, App}, Mask, SvcOpts};
+            {{TPid, Caps, App}, SvcOpts};
         false = No ->
             No
     end.
@@ -693,7 +683,7 @@ cfg_acc({SvcName, #diameter_service{applications = Apps} = Rec, Opts},
                local   = init_peers(),
                remote  = init_peers(),
                monitor = mref(get_value(monitor, Opts)),
-               options = service_options(Opts)},
+               options = service_options(lists:keydelete(monitor, 1, Opts))},
     {S, Acc};
 
 cfg_acc({_Ref, Type, _Opts} = T, {S, Acc})
@@ -709,24 +699,14 @@ init_peers() ->
                                %%  TPid}
 
 service_options(Opts) ->
-    [{sequence, proplists:get_value(sequence, Opts, ?NOMASK)},
-     {share_peers, get_value(share_peers, Opts)},
-     {use_shared_peers, get_value(use_shared_peers, Opts)},
-     {restrict_connections, proplists:get_value(restrict_connections,
-                                                Opts,
-                                                ?RESTRICT)},
-     {spawn_opt, proplists:get_value(spawn_opt, Opts, [])},
-     {string_decode, proplists:get_value(string_decode, Opts, true)},
-     {incoming_maxlen, proplists:get_value(incoming_maxlen, Opts, 16#FFFFFF)},
-     {strict_mbit, proplists:get_value(strict_mbit, Opts, true)}].
-%% The order of options is significant since we match against the list.
+    maps:from_list(Opts).
 
 mref(false = No) ->
     No;
 mref(P) ->
     monitor(process, P).
 
-init_shared(#state{options = [_, _, {_,T} | _],
+init_shared(#state{options = #{use_shared_peers := T},
                    service_name = Svc}) ->
     notify(T, Svc, {service, self()}).
 
@@ -824,7 +804,8 @@ start(Ref, Type, Opts, State) ->
 
 start(Ref, Type, Opts, N, #state{watchdogT = WatchdogT,
                                  local = {PeerT, _, _},
-                                 options = SvcOpts,
+                                 options = #{string_decode := SD}
+                                 = SvcOpts0,
                                  service_name = SvcName,
                                  service = Svc0})
   when Type == connect;
@@ -832,21 +813,25 @@ start(Ref, Type, Opts, N, #state{watchdogT = WatchdogT,
     #diameter_service{applications = Apps}
         = Svc1
         = merge_service(Opts, Svc0),
-    Svc = binary_caps(Svc1, proplists:get_value(string_decode, SvcOpts, true)),
-    RecvData = diameter_traffic:make_recvdata([SvcName,
-                                               PeerT,
-                                               Apps,
-                                               SvcOpts]),
-    T = {{spawn_opts([Opts, SvcOpts]), RecvData}, Opts, SvcOpts, Svc},
+    Svc = binary_caps(Svc1, SD),
+    SvcOpts = merge_options(Opts, SvcOpts0),
+    RecvData = diameter_traffic:make_recvdata([SvcName, PeerT, Apps, SvcOpts]),
+    T = {Opts, SvcOpts, RecvData, Svc},
     Rec = #watchdog{type = Type,
                     ref = Ref,
                     options = Opts},
+
     diameter_lib:fold_n(fun(_,A) ->
                                 [wd(Type, Ref, T, WatchdogT, Rec) | A]
                         end,
                         [],
                         N).
 
+merge_options(Opts, SvcOpts) ->
+    Keys = maps:keys(SvcOpts),
+    Map = maps:from_list([KV || {K,_} = KV <- Opts, lists:member(K, Keys)]),
+    maps:merge(SvcOpts, Map).
+
 binary_caps(Svc, true) ->
     Svc;
 binary_caps(#diameter_service{capabilities = Caps} = Svc, false) ->
@@ -861,12 +846,6 @@ wd(Type, Ref, T, WatchdogT, Rec) ->
 %% record so that each watchdog may get a different record. This
 %% record is what is passed back into application callbacks.
 
-spawn_opts(Optss) ->
-    SpawnOpts = get_value(spawn_opt, Optss, []),
-    [T || T <- SpawnOpts,
-          T /= link,
-          T /= monitor].
-
 start_watchdog(Type, Ref, T) ->
     {_MRef, Pid} = diameter_watchdog:start({Type, Ref}, T),
     Pid.
@@ -1079,18 +1058,6 @@ keyfind([Key | Rest], Pos, L) ->
             T
     end.
 
-%% get_value/3
-
-get_value(_, [], Def) ->
-    Def;
-get_value(Key, [L | Rest], Def) ->
-    case lists:keyfind(Key, 1, L) of
-        {_,V} ->
-            V;
-        _ ->
-            get_value(Key, Rest, Def)
-    end.
-
 %% find_outgoing_app/2
 
 find_outgoing_app(Alias, Apps) ->
@@ -1388,19 +1355,19 @@ send_event(#diameter_event{service = SvcName} = E) ->
 %% # share_peer/5
 %% ---------------------------------------------------------------------------
 
-share_peer(up, Caps, Apps, TPid, #state{options = [_, {_,T} | _],
+share_peer(up, Caps, Apps, TPid, #state{options = #{share_peers := SP},
                                         service_name = Svc}) ->
-    notify(T, Svc, {peer, TPid, [A || {_,A} <- Apps], Caps});
+    notify(SP, Svc, {peer, TPid, [A || {_,A} <- Apps], Caps});
 
-share_peer(down, _Caps, _Apps, TPid, #state{options = [_, {_,T} | _],
+share_peer(down, _Caps, _Apps, TPid, #state{options = #{share_peers := SP},
                                             service_name = Svc}) ->
-    notify(T, Svc, {peer, TPid}).
+    notify(SP, Svc, {peer, TPid}).
 
 %% ---------------------------------------------------------------------------
 %% # share_peers/2
 %% ---------------------------------------------------------------------------
 
-share_peers(Pid, #state{options = [_, {_,SP} | _],
+share_peers(Pid, #state{options = #{share_peers := SP},
                         local = {PeerT, AppT, _}}) ->
     is_remote(Pid, SP)
         andalso ets:foldl(fun(T, N) -> N + sp(Pid, AppT, T) end,
@@ -1432,7 +1399,8 @@ is_remote(Pid, T) ->
 %% # remote_peer_up/4
 %% ---------------------------------------------------------------------------
 
-remote_peer_up(TPid, Aliases, Caps, #state{options = [_, _, {_,T} | _]} = S) ->
+remote_peer_up(TPid, Aliases, Caps, #state{options = #{use_shared_peers := T}}
+                                    = S) ->
     is_remote(TPid, T) andalso rpu(TPid, Aliases, Caps, S).
 
 rpu(TPid, Aliases, Caps, #state{service = Svc, remote = RT}) ->
diff --git a/lib/diameter/src/base/diameter_traffic.erl b/lib/diameter/src/base/diameter_traffic.erl
index be934a6255..3489602a39 100644
--- a/lib/diameter/src/base/diameter_traffic.erl
+++ b/lib/diameter/src/base/diameter_traffic.erl
@@ -73,9 +73,9 @@
          service_name :: diameter:service_name(),
          apps         :: [#diameter_app{}],
          sequence     :: diameter:sequence(),
-         codec        :: [{string_decode, boolean()}
-                          | {strict_mbit, boolean()}
-                          | {incoming_maxlen, diameter:message_length()}]}).
+         codec        :: #{string_decode := boolean(),
+                           strict_mbit := boolean(),
+                           incoming_maxlen := diameter:message_length()}}).
 %% Note that incoming_maxlen is currently handled in diameter_peer_fsm,
 %% so that any message exceeding the maximum is discarded. Retain the
 %% option in case we want to extend the values and semantics.
@@ -94,15 +94,16 @@
 %% ---------------------------------------------------------------------------
 
 make_recvdata([SvcName, PeerT, Apps, SvcOpts | _]) ->
-    {_,_} = Mask = proplists:get_value(sequence, SvcOpts),
-    #recvdata{service_name = SvcName,
-              peerT = PeerT,
-              apps = Apps,
-              sequence = Mask,
-              codec = [T || {K,_} = T <- SvcOpts,
-                            lists:member(K, [string_decode,
-                                             incoming_maxlen,
-                                             strict_mbit])]}.
+    #{sequence := {_,_} = Mask, spawn_opt := Opts}
+        = SvcOpts,
+    {Opts, #recvdata{service_name = SvcName,
+                     peerT = PeerT,
+                     apps = Apps,
+                     sequence = Mask,
+                     codec = maps:with([string_decode,
+                                        strict_mbit,
+                                        incoming_maxlen],
+                                       SvcOpts)}}.
 
 %% ---------------------------------------------------------------------------
 %% peer_up/1
@@ -227,9 +228,9 @@ receive_message(TPid, Route, Pkt, Dict0, RecvData) ->
 %% recv/6
 
 %% Incoming request ...
-recv(true, Ack, TPid, Pkt, Dict0, T)
+recv(true, Ack, TPid, Pkt, Dict0, RecvData)
   when is_boolean(Ack) ->
-    spawn_request(Ack, TPid, Pkt, Dict0, T);
+    spawn_request(Ack, TPid, Pkt, Dict0, RecvData);
 
 %% ... answer to known request ...
 recv(false, {Pid, Ref, TPid}, _, Pkt, Dict0, _) ->
@@ -269,11 +270,9 @@ recv_request(Ack,
              = Pkt,
              Dict0,
              #recvdata{peerT = PeerT,
-                       apps = Apps,
-                       codec = Opts}
+                       apps = Apps}
              = RecvData) ->
     Ack andalso (TPid ! {handler, self()}),
-    diameter_codec:setopts([{common_dictionary, Dict0} | Opts]),
     send_A(recv_R(diameter_service:find_incoming_app(PeerT, TPid, Id, Apps),
                   TPid,
                   Pkt,
@@ -289,9 +288,10 @@ recv_R({#diameter_app{id = Id, dictionary = AppDict} = App, Caps},
        TPid,
        Pkt0,
        Dict0,
-       RecvData) ->
+       #recvdata{codec = Opts}
+       = RecvData) ->
     incr(recv, Pkt0, TPid, AppDict),
-    Pkt = errors(Id, diameter_codec:decode(Id, AppDict, Pkt0)),
+    Pkt = errors(Id, diameter_codec:decode(Id, AppDict, Opts, Pkt0)),
     incr_error(recv, Pkt, TPid, AppDict),
     {Caps, Pkt, App, recv_R(App, TPid, Dict0, Caps, RecvData, Pkt)};
 %% Note that the decode is different depending on whether or not Id is
@@ -667,7 +667,7 @@ is_loop(Code, Vid, OH, Dict0, [_ | Avps])
     is_loop(Code, Vid, OH, Dict0, Avps);
 
 is_loop(Code, Vid, OH, Dict0, Avps) ->
-    is_loop(Code, Vid, Dict0:avp(encode, OH, 'Route-Record'), Dict0, Avps).
+    is_loop(Code, Vid, list_to_binary(OH), Dict0, Avps).
 
 %% reply/5
 
@@ -963,14 +963,14 @@ answer_message(OH, OR, RC, Dict0, #diameter_packet{avps = Avps,
     ['answer-message', {'Origin-Host', OH},
                        {'Origin-Realm', OR},
                        {'Result-Code', RC}]
-        ++ session_id(Code, Vid, Dict0, Avps)
+        ++ session_id(Code, Vid, Avps)
         ++ failed_avp(RC, Es).
 
-session_id(Code, Vid, Dict0, Avps)
+session_id(Code, Vid, Avps)
   when is_list(Avps) ->
     try
         #diameter_avp{data = Bin} = find_avp(Code, Vid, Avps),
-        [{'Session-Id', [Dict0:avp(decode, Bin, 'Session-Id')]}]
+        [{'Session-Id', [Bin]}]
     catch
         error: _ ->
             []
@@ -1251,11 +1251,10 @@ answer_rc(_, _, Sent) ->
 %%
 %% In the process spawned for the outgoing request.
 
-send_R(SvcName, AppOrAlias, Msg, Opts, Caller) ->
-    case pick_peer(SvcName, AppOrAlias, Msg, Opts) of
-        {Transport, Mask, SvcOpts} ->
-            diameter_codec:setopts(SvcOpts),
-            send_request(Transport, Mask, Msg, Opts, Caller, SvcName);
+send_R(SvcName, AppOrAlias, Msg, CallOpts, Caller) ->
+    case pick_peer(SvcName, AppOrAlias, Msg, CallOpts) of
+        {{_,_,_} = Transport, SvcOpts} ->
+            send_request(Transport, SvcOpts, Msg, CallOpts, Caller, SvcName);
         {error, _} = No ->
             No
     end.
@@ -1302,42 +1301,45 @@ mo(T, _) ->
 
 send_request({TPid, Caps, App}
              = Transport,
-             Mask,
-             Msg,
-             Opts,
+             #{sequence := Mask}
+             = SvcOpts,
+             Msg0,
+             CallOpts,
              Caller,
              SvcName) ->
-    Pkt = make_prepare_packet(Mask, Msg),
-
-    send_R(cb(App, prepare_request, [Pkt, SvcName, {TPid, Caps}]),
-           Pkt,
-           Transport,
-           Opts,
-           Caller,
-           SvcName,
-           []).
+    Pkt = make_prepare_packet(Mask, Msg0),
+
+    case prepare(cb(App, prepare_request, [Pkt, SvcName, {TPid, Caps}]), []) of
+        [Msg | Fs] ->
+            ReqPkt = make_request_packet(Msg, Pkt),
+            EncPkt = encode(App#diameter_app.dictionary, TPid, ReqPkt, Fs),
+            T = send_R(ReqPkt, EncPkt, Transport, CallOpts, Caller, SvcName),
+            Ans = recv_answer(SvcName, App, CallOpts, T),
+            handle_answer(SvcName, SvcOpts, App, Ans);
+        {discard, Reason} ->
+            {error, Reason};
+        discard ->
+            {error, discarded};
+        {error, Reason} ->
+            ?ERROR({invalid_return, Reason, prepare_request, App})
+    end.
 
-%% send_R/7
+%% prepare/2
 
-send_R({send, Msg}, Pkt, Transport, Opts, Caller, SvcName, Fs) ->
-    send_R(make_request_packet(Msg, Pkt),
-           Transport,
-           Opts,
-           Caller,
-           SvcName,
-           Fs);
+prepare({send, Msg}, Fs) ->
+    [Msg | Fs];
 
-send_R({discard, Reason} , _, _, _, _, _, _) ->
-    {error, Reason};
+prepare({eval_packet, RC, F}, Fs) ->
+    prepare(RC, [F|Fs]);
 
-send_R(discard, _, _, _, _, _, _) ->
-    {error, discarded};
+prepare({discard, _Reason} = RC, _) ->
+    RC;
 
-send_R({eval_packet, RC, F}, Pkt, T, Opts, Caller, SvcName, Fs) ->
-    send_R(RC, Pkt, T, Opts, Caller, SvcName, [F|Fs]);
+prepare(discard = RC, _) ->
+    RC;
 
-send_R(E, _, {_, _, App}, _, _, _, _) ->
-    ?ERROR({invalid_return, E, prepare_request, App}).
+prepare(Reason, _) ->
+    {error, Reason}.
 
 %% make_prepare_packet/2
 %%
@@ -1445,34 +1447,27 @@ fold_record(Rec, R) ->
 
 %% send_R/6
 
-send_R(Pkt0,
-       {TPid, Caps, #diameter_app{dictionary = AppDict} = App},
-       Opts,
+send_R(ReqPkt,
+       EncPkt,
+       {TPid, Caps, #diameter_app{dictionary = AppDict}},
+       #options{timeout = Timeout},
        {Pid, Ref},
-       SvcName,
-       Fs) ->
-    Pkt = encode(AppDict, TPid, Pkt0, Fs),
-
-    #options{timeout = Timeout}
-        = Opts,
-
+       SvcName) ->
     Req = #request{ref = Ref,
                    caller = Pid,
                    handler = self(),
                    transport = TPid,
                    caps = Caps,
-                   packet = Pkt0},
+                   packet = ReqPkt},
 
-    incr(send, Pkt, TPid, AppDict),
-    {TRef, MRef} = zend_requezt(TPid, Pkt, Req, SvcName, Timeout),
+    incr(send, EncPkt, TPid, AppDict),
+    {TRef, MRef} = zend_requezt(TPid, EncPkt, Req, SvcName, Timeout),
     Pid ! Ref,  %% tell caller a send has been attempted
-    handle_answer(SvcName,
-                  App,
-                  recv_A(Timeout, SvcName, App, Opts, {TRef, MRef, Req})).
+    {TRef, MRef, Req}.
 
-%% recv_A/5
+%% recv_answer/4
 
-recv_A(Timeout, SvcName, App, Opts, {TRef, MRef, #request{ref = Ref} = Req}) ->
+recv_answer(SvcName, App, CallOpts, {TRef, MRef, #request{ref = Ref} = Req}) ->
     %% Matching on TRef below ensures we ignore messages that pertain
     %% to a previous transport prior to failover. The answer message
     %% includes the pid of the transport on which it was received,
@@ -1483,97 +1478,92 @@ recv_A(Timeout, SvcName, App, Opts, {TRef, MRef, #request{ref = Ref} = Req}) ->
         {timeout = Reason, TRef, _} ->        %% No timely reply
             {error, Req, Reason};
         {'DOWN', MRef, process, _, _} when false /= MRef -> %% local peer_down
-            failover(SvcName, App, Req, Opts, Timeout);
+            failover(SvcName, App, Req, CallOpts);
         {failover, TRef} ->                   %% local or remote peer_down
-            failover(SvcName, App, Req, Opts, Timeout)
+            failover(SvcName, App, Req, CallOpts)
     end.
 
-%% failover/5
+%% failover/4
 
-failover(SvcName, App, Req, Opts, Timeout) ->
-    retransmit(pick_peer(SvcName, App, Req, Opts),
-               Req,
-               Opts,
-               SvcName,
-               Timeout).
+failover(SvcName, App, Req, CallOpts) ->
+    resend_request(pick_peer(SvcName, App, Req, CallOpts),
+                   Req,
+                   CallOpts,
+                   SvcName).
 
-%% handle_answer/3
+%% handle_answer/4
 
-handle_answer(SvcName, App, {error, Req, Reason}) ->
-    handle_error(App, Req, Reason, SvcName);
+handle_answer(SvcName, _, App, {error, Req, Reason}) ->
+    #request{packet = Pkt,
+             transport = TPid,
+             caps = Caps}
+        = Req,
+    cb(App, handle_error, [Reason, msg(Pkt), SvcName, {TPid, Caps}]);
 
 handle_answer(SvcName,
-              #diameter_app{dictionary = AppDict,
-                            id = Id}
+              SvcOpts,
+              #diameter_app{id = Id,
+                            dictionary = AppDict,
+                            options = [{answer_errors, AE} | _]}
               = App,
               {answer, Req, Dict0, Pkt}) ->
     MsgDict = msg_dict(AppDict, Dict0, Pkt),
-    handle_A(errors(Id, diameter_codec:decode({MsgDict, AppDict}, Pkt)),
-             SvcName,
-             MsgDict,
-             Dict0,
-             App,
-             Req).
-
-%% We don't really need to do a full decode if we're a relay and will
-%% just resend with a new hop by hop identifier, but might a proxy
-%% want to examine the answer?
-
-handle_A(Pkt, SvcName, Dict, Dict0, App, #request{transport = TPid} = Req) ->
-    AppDict = App#diameter_app.dictionary,
-
-    incr(recv, Pkt, TPid, AppDict),
-
-    try
-        incr_result(recv, Pkt, TPid, {Dict, AppDict, Dict0}) %% count incoming
-    of
-        _ -> answer(Pkt, SvcName, App, Req)
-    catch
-        exit: {no_result_code, _} ->
-            %% RFC 6733 requires one of Result-Code or
-            %% Experimental-Result, but the decode will have detected
-            %% a missing AVP. If both are optional in the dictionary
-            %% then this isn't a decode error: just continue on.
-            answer(Pkt, SvcName, App, Req);
-        exit: {invalid_error_bit, {_, _, _, Avp}} ->
-            #diameter_packet{errors = Es}
-                = Pkt,
-            E = {5004, Avp},
-            answer(Pkt#diameter_packet{errors = [E|Es]}, SvcName, App, Req)
-    end.
-
-%% answer/4
-
-answer(Pkt,
-       SvcName,
-       #diameter_app{module = ModX,
-                     options = [{answer_errors, AE} | _]},
-       Req) ->
-    a(Pkt, SvcName, ModX, AE, Req).
-
--spec a(_, _, _) -> no_return().  %% silence dialyzer
-
-a(#diameter_packet{errors = Es}
-  = Pkt,
-  SvcName,
-  ModX,
-  AE,
-  #request{transport = TPid,
-           caps = Caps,
-           packet = P})
-  when [] == Es;
-       callback == AE ->
-    cb(ModX, handle_answer, [Pkt, msg(P), SvcName, {TPid, Caps}]);
-
-a(Pkt, SvcName, _, AE, _) ->
-    a(Pkt#diameter_packet.header, SvcName, AE).
-
-a(Hdr, SvcName, report) ->
+    DecPkt = errors(Id, diameter_codec:decode({MsgDict, AppDict},
+                                              SvcOpts,
+                                              Pkt)),
+    #request{transport = TPid}
+        = Req,
+
+    incr(recv, DecPkt, TPid, AppDict),
+
+    AnsPkt = try
+                 incr_result(recv, DecPkt, TPid, {MsgDict, AppDict, Dict0})
+             of
+                 _ -> DecPkt
+             catch
+                 exit: {no_result_code, _} ->
+                     %% RFC 6733 requires one of Result-Code or
+                     %% Experimental-Result, but the decode will have
+                     %% detected a missing AVP. If both are optional in
+                     %% the dictionary then this isn't a decode error:
+                     %% just continue on.
+                     DecPkt;
+                 exit: {invalid_error_bit, {_, _, _, Avp}} ->
+                     #diameter_packet{errors = Es}
+                         = DecPkt,
+                     E = {5004, Avp},
+                     DecPkt#diameter_packet{errors = [E|Es]}
+             end,
+
+    handle_answer(AnsPkt, SvcName, App, AE, Req).
+
+%% handle_answer/5
+
+handle_answer(#diameter_packet{errors = Es}
+              = Pkt,
+              SvcName,
+              App,
+              AE,
+              #request{transport = TPid,
+                       caps = Caps,
+                       packet = P})
+  when callback == AE;
+       [] == Es ->
+    cb(App, handle_answer, [Pkt, msg(P), SvcName, {TPid, Caps}]);
+
+handle_answer(#diameter_packet{header = H}, SvcName, _, AE, _) ->
+    handle_error(H, SvcName, AE).
+
+%% handle_error/3
+
+-spec handle_error(_, _, _) -> no_return().  %% silence dialyzer
+
+handle_error(Hdr, SvcName, report) ->
     MFA = {?MODULE, handle_answer, [SvcName, Hdr]},
     diameter_lib:warning_report(errors, MFA),
-    a(Hdr, SvcName, discard);
+    handle_error(Hdr, SvcName, discard);
 
-a(Hdr, SvcName, discard) ->
+handle_error(Hdr, SvcName, discard) ->
     x({answer_errors, {SvcName, Hdr}}).
 
 %% Note that we don't check that the application id in the answer's
@@ -1584,16 +1574,16 @@ a(Hdr, SvcName, discard) ->
 %% timer value is ignored. This means that an answer could be accepted
 %% from a peer after timeout in the case of failover.
 
-%% retransmit/5
+%% resend_request/4
 
-retransmit({{_,_,App} = Transport, _, _}, Req, Opts, SvcName, Timeout) ->
-    try retransmit(Transport, Req, SvcName, Timeout) of
-        T -> recv_A(Timeout, SvcName, App, Opts, T)
+resend_request({{_,_,App} = Transport, _}, Req, CallOpts, SvcName) ->
+    try retransmit(Transport, Req, SvcName, CallOpts#options.timeout) of
+        T -> recv_answer(SvcName, App, CallOpts, T)
     catch
         ?FAILURE(Reason) -> {error, Req, Reason}
     end;
 
-retransmit(_, Req, _, _, _) ->  %% no alternate peer
+resend_request(_, Req, _, _) ->  %% no alternate peer
     {error, Req, failover}.
 
 %% pick_peer/4
@@ -1603,8 +1593,8 @@ retransmit(_, Req, _, _, _) ->  %% no alternate peer
 pick_peer(SvcName,
           App,
           #request{packet = #diameter_packet{msg = Msg}},
-          Opts) ->
-    pick_peer(SvcName, App, Msg, Opts#options{extra = []});
+          CallOpts) ->
+    pick_peer(SvcName, App, Msg, CallOpts#options{extra = []});
 
 pick_peer(_, _, undefined, _) ->
     {error, no_connection};
@@ -1613,27 +1603,13 @@ pick_peer(SvcName,
           AppOrAlias,
           Msg,
           #options{filter = Filter, extra = Xtra}) ->
-    pick(diameter_service:pick_peer(SvcName,
-                                    AppOrAlias,
-                                    {fun(D) -> get_destination(D, Msg) end,
-                                     Filter,
-                                     Xtra})).
-
-pick(false) ->
-    {error, no_connection};
-
-pick(T) ->
-    T.
-
-%% handle_error/4
-
-handle_error(App,
-             #request{packet = Pkt,
-                      transport = TPid,
-                      caps = Caps},
-             Reason,
-             SvcName) ->
-    cb(App, handle_error, [Reason, msg(Pkt), SvcName, {TPid, Caps}]).
+    X = {fun(D) -> get_destination(D, Msg) end, Filter, Xtra},
+    case diameter_service:pick_peer(SvcName, AppOrAlias, X) of
+        false ->
+            {error, no_connection};
+        T ->
+            T
+    end.
 
 msg(#diameter_packet{msg = undefined, bin = Bin}) ->
     Bin;
@@ -1745,14 +1721,14 @@ send(Pid, Pkt, Route) ->
 
 retransmit({TPid, Caps, App}
            = Transport,
-           #request{packet = Pkt0}
+           #request{packet = ReqPkt}
            = Req,
            SvcName,
            Timeout) ->
     undefined == get(TPid)       %% Don't failover to a peer we've
         orelse ?THROW(timeout),  %% already sent to.
 
-    Pkt = make_retransmit_packet(Pkt0),
+    Pkt = make_retransmit_packet(ReqPkt),
 
     retransmit(cb(App, prepare_retransmit, [Pkt, SvcName, {TPid, Caps}]),
                Transport,
@@ -1789,21 +1765,21 @@ retransmit({eval_packet, RC, F}, Transport, Req, SvcName, Timeout, Fs) ->
 retransmit(T, {_, _, App}, _, _, _, _) ->
     ?ERROR({invalid_return, T, prepare_retransmit, App}).
 
-resend_request(Pkt0,
+resend_request(ReqPkt,
                {TPid, Caps, #diameter_app{dictionary = AppDict}},
                Req0,
                SvcName,
                Tmo,
                Fs) ->
-    Pkt = encode(AppDict, TPid, Pkt0, Fs),
+    EncPkt = encode(AppDict, TPid, ReqPkt, Fs),
 
     Req = Req0#request{transport = TPid,
-                       packet = Pkt0,
+                       packet = ReqPkt,
                        caps = Caps},
 
-    ?LOG(retransmission, Pkt#diameter_packet.header),
-    incr(TPid, {msg_id(Pkt, AppDict), send, retransmission}),
-    {TRef, MRef} = zend_requezt(TPid, Pkt, Req, SvcName, Tmo),
+    ?LOG(retransmission, EncPkt#diameter_packet.header),
+    incr(TPid, {msg_id(EncPkt, AppDict), send, retransmission}),
+    {TRef, MRef} = zend_requezt(TPid, EncPkt, Req, SvcName, Tmo),
     {TRef, MRef, Req}.
 
 %% peer_monitor/2
@@ -1905,7 +1881,7 @@ ungroup(Avp) ->
 avp_decode(Dict, Name, #diameter_avp{value = undefined,
                                      data = Bin}
                        = Avp) ->
-    try Dict:avp(decode, Bin, Name) of
+    try Dict:avp(decode, Bin, Name, decode_opts(Dict)) of
         V ->
             Avp#diameter_avp{value = V}
     catch
@@ -1916,8 +1892,6 @@ avp_decode(_, _, #diameter_avp{} = Avp) ->
     Avp.
 
 cb(#diameter_app{module = [_|_] = M}, F, A) ->
-    eval(M, F, A);
-cb([_|_] = M, F, A) ->
     eval(M, F, A).
 
 eval([M|X], F, A) ->
@@ -1925,3 +1899,10 @@ eval([M|X], F, A) ->
 
 choose(true, X, _)  -> X;
 choose(false, _, X) -> X.
+
+%% Decode options sufficient for AVP extraction.
+decode_opts(Dict) ->
+    #{string_decode => false,
+      strict_mbit => false,
+      failed_avp => false,
+      dictionary => Dict}.
diff --git a/lib/diameter/src/base/diameter_types.erl b/lib/diameter/src/base/diameter_types.erl
index 95361e8422..17164ec89a 100644
--- a/lib/diameter/src/base/diameter_types.erl
+++ b/lib/diameter/src/base/diameter_types.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2010-2015. 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.
@@ -26,32 +26,16 @@
 %%
 
 %% Basic types.
--export(['OctetString'/2,
-         'Integer32'/2,
-         'Integer64'/2,
-         'Unsigned32'/2,
-         'Unsigned64'/2,
-         'Float32'/2,
-         'Float64'/2]).
-
-%% Derived types.
--export(['Address'/2,
-         'Time'/2,
-         'UTF8String'/2,
-         'DiameterIdentity'/2,
-         'DiameterURI'/2,
-         'IPFilterRule'/2,
-         'QoSFilterRule'/2]).
-
-%% Functions taking the AVP name in question as second parameter.
 -export(['OctetString'/3,
          'Integer32'/3,
          'Integer64'/3,
          'Unsigned32'/3,
          'Unsigned64'/3,
          'Float32'/3,
-         'Float64'/3,
-         'Address'/3,
+         'Float64'/3]).
+
+%% Derived types.
+-export(['Address'/3,
          'Time'/3,
          'UTF8String'/3,
          'DiameterIdentity'/3,
@@ -89,81 +73,80 @@
 %%    AVP Data Format is needed, a new version of this RFC must be created.
 %% --------------------
 
-'OctetString'(decode, Bin)
+'OctetString'(decode, Bin, #{string_decode := true})
   when is_binary(Bin) ->
-    case diameter_codec:getopt(string_decode) of
-        true ->
-            binary_to_list(Bin);
-        false ->
-            Bin
-    end;
-
-'OctetString'(decode, B) ->
+    binary_to_list(Bin);
+
+'OctetString'(decode, Bin, _)
+  when is_binary(Bin) ->
+    Bin;
+
+'OctetString'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
-'OctetString'(encode, zero) ->
+'OctetString'(encode, zero, _) ->
     <<>>;
 
-'OctetString'(encode, Str) ->
+'OctetString'(encode, Str, _) ->
     iolist_to_binary(Str).
 
 %% --------------------
 
-'Integer32'(decode, <<X:32/signed>>) ->
+'Integer32'(decode, <<X:32/signed>>, _) ->
     X;
 
-'Integer32'(decode, B) ->
+'Integer32'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
-'Integer32'(encode, zero) ->
+'Integer32'(encode, zero, _) ->
     <<0:32/signed>>;
 
-'Integer32'(encode, I)
+'Integer32'(encode, I, _)
   when ?SINT(32,I) ->
     <<I:32/signed>>.
 
 %% --------------------
 
-'Integer64'(decode, <<X:64/signed>>) ->
+'Integer64'(decode, <<X:64/signed>>, _) ->
     X;
 
-'Integer64'(decode, B) ->
+'Integer64'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
-'Integer64'(encode, zero) ->
+'Integer64'(encode, zero, _) ->
     <<0:64/signed>>;
 
-'Integer64'(encode, I)
+'Integer64'(encode, I, _)
   when ?SINT(64,I) ->
     <<I:64/signed>>.
 
 %% --------------------
 
-'Unsigned32'(decode, <<X:32>>) ->
+'Unsigned32'(decode, <<X:32>>, _) ->
     X;
 
-'Unsigned32'(decode, B) ->
+'Unsigned32'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
-'Unsigned32'(encode, zero) ->
+'Unsigned32'(encode, zero, _) ->
     <<0:32>>;
 
-'Unsigned32'(encode, I)
+'Unsigned32'(encode, I, _)
   when ?UINT(32,I) ->
     <<I:32>>.
 
 %% --------------------
 
-'Unsigned64'(decode, <<X:64>>) ->
+'Unsigned64'(decode, <<X:64>>, _) ->
     X;
 
-'Unsigned64'(decode, B) ->
+'Unsigned64'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
-'Unsigned64'(encode, zero) ->
+'Unsigned64'(encode, zero, _) ->
     <<0:64>>;
 
-'Unsigned64'(encode, I)
+'Unsigned64'(encode, I, _)
   when ?UINT(64,I) ->
     <<I:64>>.
 
@@ -184,25 +167,25 @@
 %% arithmetic is performed on the decoded value. Better to be explicit
 %% that precision has been lost.
 
-'Float32'(decode, <<S:1, 255:8, _:23>>) ->
+'Float32'(decode, <<S:1, 255:8, _:23>>, _) ->
     choose(S, infinity, '-infinity');
 
-'Float32'(decode, <<X:32/float>>) ->
+'Float32'(decode, <<X:32/float>>, _) ->
     X;
 
-'Float32'(decode, B) ->
+'Float32'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
-'Float32'(encode, zero) ->
+'Float32'(encode, zero, _) ->
     <<0.0:32/float>>;
 
-'Float32'(encode, infinity) ->
+'Float32'(encode, infinity, _) ->
     <<0:1, 255:8, 0:23>>;
 
-'Float32'(encode, '-infinity') ->
+'Float32'(encode, '-infinity', _) ->
     <<1:1, 255:8, 0:23>>;
 
-'Float32'(encode, X)
+'Float32'(encode, X, _)
   when is_float(X) ->
     <<X:32/float>>.
 %% Note that this could also encode infinity/-infinity for large
@@ -222,25 +205,25 @@
 
 %% The 64 bit format is entirely analogous to the 32 bit format.
 
-'Float64'(decode, <<S:1, 2047:11, _:52>>) ->
+'Float64'(decode, <<S:1, 2047:11, _:52>>, _) ->
     choose(S, infinity, '-infinity');
 
-'Float64'(decode, <<X:64/float>>) ->
+'Float64'(decode, <<X:64/float>>, _) ->
     X;
 
-'Float64'(decode, B) ->
+'Float64'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
-'Float64'(encode, infinity) ->
+'Float64'(encode, infinity, _) ->
     <<0:1, 2047:11, 0:52>>;
 
-'Float64'(encode, '-infinity') ->
+'Float64'(encode, '-infinity', _) ->
     <<1:1, 2047:11, 0:52>>;
 
-'Float64'(encode, zero) ->
+'Float64'(encode, zero, _) ->
     <<0.0:64/float>>;
 
-'Float64'(encode, X)
+'Float64'(encode, X, _)
   when is_float(X) ->
     <<X:64/float>>.
 
@@ -256,18 +239,18 @@
 %%    format.
 %% --------------------
 
-'Address'(encode, zero) ->
+'Address'(encode, zero, _) ->
     <<0:48>>;
 
-'Address'(decode, <<A:16, B/binary>>)
+'Address'(decode, <<A:16, B/binary>>, _)
   when 1 == A,  4 == size(B);
        2 == A, 16 == size(B) ->
     list_to_tuple([N || <<N:A/unit:8>> <= B]);
 
-'Address'(decode, B) ->
+'Address'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
-'Address'(encode, T) ->
+'Address'(encode, T, _) ->
     Ns = tuple_to_list(diameter_lib:ipaddr(T)),  %% length 4 or 8
     A = length(Ns) div 4,                        %% 1 or 2
     B = << <<N:A/unit:8>> || N <- Ns >>,
@@ -278,36 +261,38 @@
 %% A DiameterIdentity is a FQDN as definined in RFC 1035, which is at
 %% least one character.
 
-'DiameterIdentity'(encode, zero) ->
+'DiameterIdentity'(encode, zero, _) ->
     <<0>>;
 
-'DiameterIdentity'(encode = M, X) ->
-    <<_,_/binary>> = 'OctetString'(M, X);
+'DiameterIdentity'(encode = M, X, Opts) ->
+    <<_,_/binary>> = 'OctetString'(M, X, Opts);
 
-'DiameterIdentity'(decode = M, <<_,_/binary>> = X) ->
-    'OctetString'(M, X);
+'DiameterIdentity'(decode = M, <<_,_/binary>> = X, Opts) ->
+    'OctetString'(M, X, Opts);
 
-'DiameterIdentity'(decode, X) ->
+'DiameterIdentity'(decode, X, _) ->
     ?INVALID_LENGTH(X).
 
 %% --------------------
 
-'DiameterURI'(decode, Bin)
+'DiameterURI'(decode, Bin, Opts)
   when is_binary(Bin) ->
-    scan_uri(Bin);
+    scan_uri(Bin, Opts);
 
-'DiameterURI'(decode, B) ->
+'DiameterURI'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
 %% The minimal DiameterURI is "aaa://x", 7 characters.
-'DiameterURI'(encode, zero) ->
+'DiameterURI'(encode, zero, _) ->
     <<0:7/unit:8>>;
 
-'DiameterURI'(encode, #diameter_uri{type = Type,
-                                    fqdn = DN,
-                                    port = PN,
-                                    transport = T,
-                                    protocol = P})
+'DiameterURI'(encode,
+              #diameter_uri{type = Type,
+                            fqdn = DN,
+                            port = PN,
+                            transport = T,
+                            protocol = P},
+              _)
   when (Type == 'aaa' orelse Type == 'aaas'),
        is_integer(PN),
        0 =< PN,
@@ -324,48 +309,47 @@
 %% defaults, so it's best to be explicit. Interpret defaults on decode
 %% since there's no choice.
 
-'DiameterURI'(encode, Str) ->
+'DiameterURI'(encode, Str, Opts) ->
     Bin = iolist_to_binary(Str),
-    #diameter_uri{} = scan_uri(Bin),  %% assert
+    #diameter_uri{} = scan_uri(Bin, Opts),  %% assert
     Bin.
 
 %% --------------------
 
 %% This minimal rule is "deny in 0 from 0.0.0.0 to 0.0.0.0", 33 characters.
-'IPFilterRule'(encode, zero) ->
+'IPFilterRule'(encode, zero, _) ->
     <<0:33/unit:8>>;
 
-'IPFilterRule'(M, X) ->
-    'OctetString'(M, X).
+'IPFilterRule'(M, X, Opts) ->
+    'OctetString'(M, X, Opts).
 
 %% --------------------
 
 %% This minimal rule is the same as for an IPFilterRule.
-'QoSFilterRule'(encode, zero) ->
+'QoSFilterRule'(encode, zero, _) ->
     <<0:33/unit:8>>;
 
-'QoSFilterRule'(M, X) ->
-    'OctetString'(M, X).
+'QoSFilterRule'(M, X, Opts) ->
+    'OctetString'(M, X, Opts).
 
 %% --------------------
 
-'UTF8String'(decode, Bin)
+'UTF8String'(decode, Bin, #{string_decode := true})
   when is_binary(Bin) ->
-    case diameter_codec:getopt(string_decode) of
-        true ->
-            %% assert list return
-            tl([0|_] = unicode:characters_to_list([0, Bin]));
-        false ->
-            <<_/binary>> = unicode:characters_to_binary(Bin)
-    end;
-
-'UTF8String'(decode, B) ->
+    %% assert list return
+    tl([0|_] = unicode:characters_to_list([0, Bin]));
+
+'UTF8String'(decode, Bin, _)
+  when is_binary(Bin) ->
+    <<_/binary>> = unicode:characters_to_binary(Bin);
+
+'UTF8String'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
-'UTF8String'(encode, zero) ->
+'UTF8String'(encode, zero, _) ->
     <<>>;
 
-'UTF8String'(encode, S) ->
+'UTF8String'(encode, S, _) ->
     <<_/binary>> = unicode:characters_to_binary(S).   %% assert binary return
 
 %% --------------------
@@ -414,67 +398,23 @@
 -define(TIME_MIN, {{1968,1,20},{3,14,8}}).  %% TIME_1900 + 1 bsl 31
 -define(TIME_MAX, {{2104,2,26},{9,42,24}}). %% TIME_2036 + 1 bsl 31
 
-'Time'(decode, <<Time:32>>) ->
+'Time'(decode, <<Time:32>>, _) ->
     Offset = msb(1 == Time bsr 31),
     calendar:gregorian_seconds_to_datetime(Time + Offset);
 
-'Time'(decode, B) ->
+'Time'(decode, B, _) ->
     ?INVALID_LENGTH(B);
 
-'Time'(encode, {{_Y,_M,_D},{_HH,_MM,_SS}} = Datetime)
+'Time'(encode, {{_Y,_M,_D},{_HH,_MM,_SS}} = Datetime, _)
   when ?TIME_MIN =< Datetime, Datetime < ?TIME_MAX ->
     S = calendar:datetime_to_gregorian_seconds(Datetime),
     T = S - msb(S < ?TIME_2036),
     0 = T bsr 32,  %% sanity check
     <<T:32>>;
 
-'Time'(encode, zero) ->
+'Time'(encode, zero, _) ->
     <<0:32>>.
 
-%% -------------------------------------------------------------------------
-
-'OctetString'(M, _, Data) ->
-    'OctetString'(M, Data).
-
-'Integer32'(M, _, Data) ->
-    'Integer32'(M, Data).
-
-'Integer64'(M, _, Data) ->
-    'Integer64'(M, Data).
-
-'Unsigned32'(M, _, Data) ->
-    'Unsigned32'(M, Data).
-
-'Unsigned64'(M, _, Data) ->
-    'Unsigned64'(M, Data).
-
-'Float32'(M, _, Data) ->
-    'Float32'(M, Data).
-
-'Float64'(M, _, Data) ->
-    'Float64'(M, Data).
-
-'Address'(M, _, Data) ->
-    'Address'(M, Data).
-
-'Time'(M, _, Data) ->
-    'Time'(M, Data).
-
-'UTF8String'(M, _, Data) ->
-    'UTF8String'(M, Data).
-
-'DiameterIdentity'(M, _, Data) ->
-    'DiameterIdentity'(M, Data).
-
-'DiameterURI'(M, _, Data) ->
-    'DiameterURI'(M, Data).
-
-'IPFilterRule'(M, _, Data) ->
-    'IPFilterRule'(M, Data).
-
-'QoSFilterRule'(M, _, Data) ->
-    'QoSFilterRule'(M, Data).
-
 %% ===========================================================================
 %% ===========================================================================
 
@@ -564,7 +504,7 @@ msb(false) -> ?TIME_2036.
 %%
 %%       aaa-protocol       = ( "diameter" / "radius" / "tacacs+" )
 
-scan_uri(Bin) ->
+scan_uri(Bin, Opts) ->
     RE = "^(aaas?)://"
          "([-a-zA-Z0-9.]{1,255})"
          "(:0{0,5}([0-9]{1,5}))?"
@@ -583,21 +523,21 @@ scan_uri(Bin) ->
                                         RE,
                                         [{capture, [1,2,4,6,8], binary}]),
     Type = to_atom(A),
-    {PN0, T0} = defaults(diameter_codec:getopt(rfc), Type),
+    {PN0, T0} = defaults(Opts, Type),
     PortNr = to_int(PN, PN0),
     0 = PortNr bsr 16,  %% assert
     #diameter_uri{type = Type,
-                  fqdn = 'OctetString'(decode, DN),
+                  fqdn = 'OctetString'(decode, DN, Opts),
                   port = PortNr,
                   transport = to_atom(T, T0),
                   protocol = to_atom(P, diameter)}.
 
 %% Choose defaults based on the RFC, since 6733 has changed them.
-defaults(3588, _) ->
+defaults(#{rfc := 3588}, _) ->
     {3868, sctp};
-defaults(6733, aaa) ->
+defaults(#{rfc := 6733}, aaa) ->
     {3868, tcp};
-defaults(6733, aaas) ->
+defaults(#{rfc := 6733}, aaas) ->
     {5658, tcp}.
 
 to_int(<<>>, N) ->
diff --git a/lib/diameter/src/base/diameter_watchdog.erl b/lib/diameter/src/base/diameter_watchdog.erl
index a2eb661870..b827925400 100644
--- a/lib/diameter/src/base/diameter_watchdog.erl
+++ b/lib/diameter/src/base/diameter_watchdog.erl
@@ -50,10 +50,6 @@
 
 -define(IS_NATURAL(N), (is_integer(N) andalso 0 =< N)).
 
--record(config,
-        {suspect = 1 :: non_neg_integer(),    %% OKAY -> SUSPECT
-         okay    = 3 :: non_neg_integer()}).  %% REOPEN -> OKAY
-
 -record(watchdog,
         {%% PCB - Peer Control Block; see RFC 3539, Appendix A
          status = initial :: initial | okay | suspect | down | reopen,
@@ -70,12 +66,18 @@
                | integer()        %% monotonic time
                | undefined,
          dictionary :: module(),  %% common dictionary
-         receive_data :: term(),
-                 %% term passed into diameter_service with incoming message
-         sequence :: diameter:sequence(),     %% mask
-         restrict :: {diameter:restriction(), boolean()},
-         shutdown = false :: boolean(),
-         config :: #config{}}).
+         receive_data :: term(),  %% term passed with incoming message
+         config :: #{sequence := diameter:sequence(),  %% mask
+                     restrict_connections := diameter:restriction(),
+                     restrict := boolean(),
+                     suspect := non_neg_integer(), %% OKAY -> SUSPECT
+                     okay := non_neg_integer()},   %% REOPEN -> OKAY
+         codec :: #{string_decode := false,
+                    strict_mbit := boolean(),
+                    failed_avp := false,
+                    rfc := 3588 | 6733,
+                    incoming_maxlen := diameter:message_length()},
+         shutdown = false :: boolean()}).
 
 %% ---------------------------------------------------------------------------
 %% start/2
@@ -85,12 +87,12 @@
 %% reason.
 %% ---------------------------------------------------------------------------
 
--spec start(Type, {RecvData, [Opt], SvcOpts, #diameter_service{}})
+-spec start(Type, {[Opt], SvcOpts, RecvData, #diameter_service{}})
    -> {reference(), pid()}
  when Type :: {connect|accept, diameter:transport_ref()},
-      RecvData :: term(),
       Opt :: diameter:transport_opt(),
-      SvcOpts :: [diameter:service_opt()].
+      SvcOpts :: map(),
+      RecvData :: term().
 
 start({_,_} = Type, T) ->
     Ack = make_ref(),
@@ -117,22 +119,23 @@ init(T) ->
     proc_lib:init_ack({ok, self()}),
     gen_server:enter_loop(?MODULE, [], i(T)).
 
-i({Ack, T, Pid, {RecvData,
-                 Opts,
-                 SvcOpts,
+i({Ack, T, Pid, {Opts,
+                 #{restrict_connections := Restrict}
+                 = SvcOpts0,
+                 RecvData,
                  #diameter_service{applications = Apps,
                                    capabilities = Caps}
                  = Svc}}) ->
     monitor(process, Pid),
     wait(Ack, Pid),
+
+    Dict0 = common_dictionary(Apps),
+    SvcOpts = SvcOpts0#{rfc => rfc(Dict0)},
     putr(restart, {T, Opts, Svc, SvcOpts}),  %% save seeing it in trace
     putr(dwr, dwr(Caps)),                    %%
-    {_,_} = Mask = proplists:get_value(sequence, SvcOpts),
-    Restrict = proplists:get_value(restrict_connections, SvcOpts),
     Nodes = restrict_nodes(Restrict),
-    Dict0 = common_dictionary(Apps),
-    diameter_codec:setopts([{common_dictionary, Dict0},
-                            {string_decode, false}]),
+    CodecKeys = [string_decode, strict_mbit, incoming_maxlen, spawn_opt, rfc],
+
     #watchdog{parent = Pid,
               transport = start(T, Opts, SvcOpts, Nodes, Dict0, Svc),
               tw = proplists:get_value(watchdog_timer,
@@ -140,9 +143,13 @@ i({Ack, T, Pid, {RecvData,
                                        ?DEFAULT_TW_INIT),
               receive_data = RecvData,
               dictionary = Dict0,
-              sequence = Mask,
-              restrict = {Restrict, lists:member(node(), Nodes)},
-              config = config(Opts)}.
+              config =
+                  maps:without(CodecKeys,
+                               config(SvcOpts#{restrict => restrict(Nodes),
+                                               suspect => 1,
+                                               okay => 3},
+                                      Opts)),
+              codec = maps:with(CodecKeys, SvcOpts#{string_decode := false})}.
 
 wait(Ref, Pid) ->
     receive
@@ -152,22 +159,31 @@ wait(Ref, Pid) ->
             exit({shutdown, D})
     end.
 
-%% config/1
+%% Regard anything but the generated RFC 3588 dictionary as modern.
+%% This affects the interpretation of defaults during the decode
+%% of values of type DiameterURI, this having changed from RFC 3588.
+%% (So much for backwards compatibility.)
+rfc(?BASE) ->
+    3588;
+rfc(_) ->
+    6733.
+
+%% config/2
 %%
 %% Could also configure counts for SUSPECT to DOWN and REOPEN to DOWN,
 %% but don't.
 
-config(Opts) ->
+config(Map, Opts) ->
     Config = proplists:get_value(watchdog_config, Opts, []),
-    lists:foldl(fun config/2, #config{}, Config).
+    lists:foldl(fun cfg/2, Map, Config).
 
-config({suspect, N}, Rec)
+cfg({suspect, N}, Map)
   when ?IS_NATURAL(N) ->
-    Rec#config{suspect = N};
+    Map#{suspect := N};
 
-config({okay, N}, Rec)
+cfg({okay, N}, Map)
   when ?IS_NATURAL(N) ->
-    Rec#config{okay = N}.
+    Map#{okay := N}.
 
 %% start/6
 
@@ -377,8 +393,8 @@ transition({accepted = T, TPid}, #watchdog{transport = TPid,
 transition({open, TPid, Hosts, _} = Open,
            #watchdog{transport = TPid,
                      status = initial,
-                     restrict = {_,R},
-                     config = #config{suspect = OS}}
+                     config = #{restrict := R,
+                                suspect := OS}}
            = S) ->
     case okay(role(), Hosts, R) of
         okay ->
@@ -396,8 +412,8 @@ transition({open, TPid, Hosts, _} = Open,
 transition({open = Key, TPid, _Hosts, T},
            #watchdog{transport = TPid,
                      status = down,
-                     config = #config{suspect = OS,
-                                      okay = RO}}
+                     config = #{suspect := OS,
+                                okay := RO}}
            = S) ->
     case RO of
         0 ->  %% non-standard: skip REOPEN
@@ -430,7 +446,7 @@ transition({'DOWN', _, process, TPid, _Reason},
 transition({'DOWN', _, process, TPid, _Reason} = D,
            #watchdog{transport = TPid,
                      status = T,
-                     restrict = {_,R}}
+                     config = #{restrict := R}}
            = S0) ->
     S = S0#watchdog{pending = false,
                     transport = undefined},
@@ -577,7 +593,7 @@ tw({M,F,A}) ->
 send_watchdog(#watchdog{pending = false,
                         transport = TPid,
                         dictionary = Dict0,
-                        sequence = Mask}
+                        config = #{sequence := Mask}}
               = S) ->
     #diameter_packet{bin = Bin} = EPkt = encode(dwr, Dict0, Mask),
     diameter_traffic:incr(send, EPkt, TPid, Dict0),
@@ -601,10 +617,11 @@ incoming(Route, Name, Pkt, S) ->
 %% rcv/3
 
 rcv('DWR', Pkt, #watchdog{transport = TPid,
-                          dictionary = Dict0}
+                          dictionary = Dict0,
+                          codec = Opts}
                 = S) ->
     ?LOG(recv, 'DWR'),
-    DPkt = diameter_codec:decode(Dict0, Pkt),
+    DPkt = diameter_codec:decode(Dict0, Opts, Pkt),
     diameter_traffic:incr(recv, DPkt, TPid, Dict0),
     diameter_traffic:incr_error(recv, DPkt, TPid, Dict0),
     #diameter_packet{header = H,
@@ -623,12 +640,13 @@ rcv('DWR', Pkt, #watchdog{transport = TPid,
     throw(S);
 
 rcv('DWA', Pkt, #watchdog{transport = TPid,
-                          dictionary = Dict0}
+                          dictionary = Dict0,
+                          codec = Opts}
                 = S) ->
     ?LOG(recv, 'DWA'),
     diameter_traffic:incr(recv, Pkt, TPid, Dict0),
     diameter_traffic:incr_rc(recv,
-                             diameter_codec:decode(Dict0, Pkt),
+                             diameter_codec:decode(Dict0, Opts, Pkt),
                              TPid,
                              Dict0),
     throw(S);
@@ -690,12 +708,12 @@ rcv(_, #watchdog{status = okay} = S) ->
 %%   SUSPECT       Receive non-DWA      Failback()
 %%                                      SetWatchdog()        OKAY
 
-rcv('DWA', #watchdog{status = suspect, config = #config{suspect = OS}} = S) ->
+rcv('DWA', #watchdog{status = suspect, config = #{suspect := OS}} = S) ->
     set_watchdog(S#watchdog{status = okay,
                             num_dwa = OS,
                             pending = false});
 
-rcv(_, #watchdog{status = suspect, config = #config{suspect = OS}} = S) ->
+rcv(_, #watchdog{status = suspect, config = #{suspect := OS}} = S) ->
     set_watchdog(S#watchdog{status = okay,
                             num_dwa = OS});
 
@@ -705,8 +723,8 @@ rcv(_, #watchdog{status = suspect, config = #config{suspect = OS}} = S) ->
 
 rcv('DWA', #watchdog{status = reopen,
                      num_dwa = N,
-                     config = #config{suspect = OS,
-                                      okay = RO}}
+                     config = #{suspect := OS,
+                                okay := RO}}
            = S)
   when N+1 == RO ->
     S#watchdog{status = okay,
@@ -837,18 +855,19 @@ restart(S) ->  %% reconnect has won race with timeout
 
 restart({{connect, _} = T, Opts, Svc, SvcOpts},
         #watchdog{parent = Pid,
-                  restrict = {R,_},
+                  config = #{restrict_connections := R}
+                         = M,
                   dictionary = Dict0}
         = S) ->
     send(Pid, {reconnect, self()}),
     Nodes = restrict_nodes(R),
     S#watchdog{transport = start(T, Opts, SvcOpts, Nodes, Dict0, Svc),
-               restrict = {R, lists:member(node(), Nodes)}};
+               config = M#{restrict => restrict(Nodes)}};
 
 %% No restriction on the number of connections to the same peer: just
 %% die. Note that a state machine never enters state REOPEN in this
 %% case.
-restart({{accept, _}, _, _, _}, #watchdog{restrict = {_, false}}) ->
+restart({{accept, _}, _, _, _}, #watchdog{config = #{restrict := false}}) ->
     stop;
 
 %% Otherwise hang around until told to die, either by the service or
@@ -892,3 +911,8 @@ restrict_nodes(Nodes)
 
 restrict_nodes(F) ->
     diameter_lib:eval(F).
+
+%% restrict/1
+
+restrict(Nodes) ->
+    lists:member(node(), Nodes).
diff --git a/lib/diameter/src/compiler/diameter_codegen.erl b/lib/diameter/src/compiler/diameter_codegen.erl
index 9dd3930866..b6fc78b6cc 100644
--- a/lib/diameter/src/compiler/diameter_codegen.erl
+++ b/lib/diameter/src/compiler/diameter_codegen.erl
@@ -150,8 +150,8 @@ erl_forms(Mod, ParseD) ->
                                     {id, 0},
                                     {vendor_id, 0},
                                     {vendor_name, 0},
-                                    {decode_avps, 2}, %% in diameter_gen.hrl
-                                    {encode_avps, 2}, %%
+                                    {decode_avps, 3}, %% in diameter_gen.hrl
+                                    {encode_avps, 3}, %%
                                     {msg_name, 2},
                                     {msg_header, 1},
                                     {rec2msg, 1},
@@ -161,8 +161,8 @@ erl_forms(Mod, ParseD) ->
                                     {avp_arity, 1},
                                     {avp_arity, 2},
                                     {avp_header, 1},
-                                    {avp, 3},
-                                    {grouped_avp, 3},
+                                    {avp, 4},
+                                    {grouped_avp, 4},
                                     {enumerated_avp, 3},
                                     {empty_value, 1},
                                     {dict, 0}]},
@@ -476,7 +476,7 @@ c_arity(Name, Avp) ->
 %%% ------------------------------------------------------------------------
 
 f_avp(ParseD) ->
-    {?function, avp, 3, avp(ParseD) ++ [?BADARG(3)]}.
+    {?function, avp, 4, avp(ParseD) ++ [?BADARG(4)]}.
 
 avp(ParseD) ->
     Native     = get_value(avp_types, ParseD),
@@ -515,19 +515,25 @@ avp(Native, Imported, Custom, Enums) ->
 not_in(List, X) ->
     not lists:member(X, List).
 
-c_base_avp({AvpName, T}) ->
-    {?clause, [?VAR('T'), ?VAR('Data'), ?Atom(AvpName)],
+c_base_avp({AvpName, "Enumerated"}) ->
+    {?clause, [?VAR('T'), ?VAR('Data'), ?Atom(AvpName), ?VAR('_')],
      [],
-     [b_base_avp(AvpName, T)]}.
+     [?CALL(enumerated_avp, [?VAR('T'), ?Atom(AvpName), ?VAR('Data')])]};
 
-b_base_avp(AvpName, "Enumerated") ->
-    ?CALL(enumerated_avp, [?VAR('T'), ?Atom(AvpName), ?VAR('Data')]);
-
-b_base_avp(AvpName, "Grouped") ->
-    ?CALL(grouped_avp, [?VAR('T'), ?Atom(AvpName), ?VAR('Data')]);
+c_base_avp({AvpName, "Grouped"}) ->
+    {?clause, [?VAR('T'), ?VAR('Data'), ?Atom(AvpName), ?VAR('Opts')],
+     [],
+     [?CALL(grouped_avp, [?VAR('T'),
+                          ?Atom(AvpName),
+                          ?VAR('Data'),
+                          ?VAR('Opts')])]};
 
-b_base_avp(_, Type) ->
-    ?APPLY(diameter_types, ?A(Type), [?VAR('T'), ?VAR('Data')]).
+c_base_avp({AvpName, Type}) ->
+    {?clause, [?VAR('T'), ?VAR('Data'), ?Atom(AvpName), ?VAR('Opts')],
+     [],
+     [?APPLY(diameter_types, ?A(Type), [?VAR('T'),
+                                        ?VAR('Data'),
+                                        ?VAR('Opts')])]}.
 
 cs_imported_avp({Mod, Avps}, Enums, CustomNames) ->
     lists:map(fun(A) -> imported_avp(Mod, A, Enums) end,
@@ -549,11 +555,12 @@ imported_avp(Mod, {AvpName, _, _, _}, _) ->
     c_imported_avp(Mod, AvpName).
 
 c_imported_avp(Mod, AvpName) ->
-    {?clause, [?VAR('T'), ?VAR('Data'), ?Atom(AvpName)],
+    {?clause, [?VAR('T'), ?VAR('Data'), ?Atom(AvpName), ?VAR('Opts')],
      [],
      [?APPLY(Mod, avp, [?VAR('T'),
                         ?VAR('Data'),
-                        ?Atom(AvpName)])]}.
+                        ?Atom(AvpName),
+                        ?VAR('Opts')])]}.
 
 cs_custom_avp({Mod, Key, Avps}, Dict) ->
     lists:map(fun(N) -> c_custom_avp(Mod, Key, N, orddict:fetch(N, Dict)) end,
@@ -561,9 +568,11 @@ cs_custom_avp({Mod, Key, Avps}, Dict) ->
 
 c_custom_avp(Mod, Key, AvpName, Type) ->
     {F,A} = custom(Key, AvpName, Type),
-    {?clause, [?VAR('T'), ?VAR('Data'), ?Atom(AvpName)],
+    {?clause, [?VAR('T'), ?VAR('Data'), ?Atom(AvpName), ?VAR('_')],
      [],
-     [?APPLY(?A(Mod), ?A(F), [?VAR('T'), ?Atom(A), ?VAR('Data')])]}.
+     [?APPLY(?A(Mod), ?A(F), [?VAR('T'),
+                              ?Atom(A),
+                              ?VAR('Data')])]}.
 
 custom(custom_types, AvpName, Type) ->
     {AvpName, Type};
@@ -592,7 +601,11 @@ enumerated_avp(Mod, Es, Enums) ->
                   Es).
 
 cs_enumerated_avp(true, Mod, Name) ->
-    [c_imported_avp(Mod, Name)];
+    [{?clause, [?VAR('T'), ?Atom(Name), ?VAR('Data')],
+     [],
+     [?APPLY(Mod, enumerated_avp, [?VAR('T'),
+                                   ?Atom(Name),
+                                   ?VAR('Data')])]}];
 cs_enumerated_avp(false, _, _) ->
     [].