3 files changed, 38 insertions, 24 deletions

diff --git a/lib/diameter/src/base/diameter.erl b/lib/diameter/src/base/diameter.erl
index 253f64133c..bd92e16fba 100644
--- a/lib/diameter/src/base/diameter.erl
+++ b/lib/diameter/src/base/diameter.erl
@@ -406,4 +406,5 @@ call(SvcName, App, Message) ->
    :: {extra, list()}
     | {filter, peer_filter()}
     | {timeout, 'Unsigned32'()}
+    | {peer, peer_ref()}
     | detach.
diff --git a/lib/diameter/src/base/diameter_service.erl b/lib/diameter/src/base/diameter_service.erl
index be50e87179..4fc49309b5 100644
--- a/lib/diameter/src/base/diameter_service.erl
+++ b/lib/diameter/src/base/diameter_service.erl
@@ -282,7 +282,8 @@ whois(SvcName) ->
                   | {alias, diameter:app_alias()},
       Opts :: {fun((Dict :: module()) -> [term()]),
                diameter:peer_filter(),
-               Xtra :: list()},
+               Xtra :: list(),
+               [diameter:peer_ref()]},
       TPid :: pid(),
       Caps :: #diameter_caps{},
       App  :: #diameter_app{},
@@ -310,10 +311,10 @@ pick(#state{options = SvcOpts}
      = S,
      #diameter_app{module = ModX, dictionary = Dict}
      = App0,
-     {DestF, Filter, Xtra}) ->
+     {DestF, Filter, Xtra, TPids}) ->
     App = App0#diameter_app{module = ModX ++ Xtra},
     [_,_] = RealmAndHost = diameter_lib:eval([DestF, Dict]),
-    case pick_peer(App, RealmAndHost, Filter, S) of
+    case pick_peer(App, RealmAndHost, [Filter | TPids], S) of
         {_TPid, _Caps} = TC ->
             {{TC, App}, SvcOpts};
         false = No ->
@@ -1522,8 +1523,14 @@ pick_peer(Local,
 
 %% peers/4
 
-peers(Alias, RH, Filter, T) ->
-    filter(Alias, RH, Filter, T, true).
+%% No peer options pointing at specific peers: search for them.
+peers(Alias, RH, [Filter], T) ->
+    filter(Alias, RH, Filter, T, true);
+
+%% Or just lookup.
+peers(_Alias, RH, [Filter | TPids], {PeerT, _AppT, _IdentT}) ->
+    {Ts, _} = filter(caps(PeerT, TPids), RH, Filter),
+    Ts.
 
 %% filter/5
 %%
diff --git a/lib/diameter/src/base/diameter_traffic.erl b/lib/diameter/src/base/diameter_traffic.erl
index 54f39afbf0..7a5a3d662a 100644
--- a/lib/diameter/src/base/diameter_traffic.erl
+++ b/lib/diameter/src/base/diameter_traffic.erl
@@ -64,7 +64,8 @@
 
 %% Record diameter:call/4 options are parsed into.
 -record(options,
-        {filter = none  :: diameter:peer_filter(),
+        {peers = []     :: [diameter:peer_ref()],
+         filter = none  :: diameter:peer_filter(),
          extra = []     :: list(),
          timeout = 5000 :: 0..16#FFFFFFFF,  %% for outgoing requests
          detach = false :: boolean()}).
@@ -1275,36 +1276,41 @@ send_R(SvcName, AppOrAlias, Msg, CallOpts, Caller) ->
 %% make_options/1
 
 make_options(Options) ->
-    make_opts(Options, false, [], none, 5000).
+    make_opts(Options, [], false, [], none, 5000).
 
 %% Do our own recursion since this is faster than a lists:foldl/3
 %% setting elements in an #options{} accumulator.
 
-make_opts([], Detach, Extra, Filter, Tmo) ->
-    #options{detach = Detach,
+make_opts([], Peers, Detach, Extra, Filter, Tmo) ->
+    #options{peers = lists:reverse(Peers),
+             detach = Detach,
              extra = Extra,
              filter = Filter,
              timeout = Tmo};
 
-make_opts([{timeout, Tmo} | Rest], Detach, Extra, Filter, _)
+make_opts([{timeout, Tmo} | Rest], Peers, Detach, Extra, Filter, _)
   when is_integer(Tmo), 0 =< Tmo ->
-    make_opts(Rest, Detach, Extra, Filter, Tmo);
+    make_opts(Rest, Peers, Detach, Extra, Filter, Tmo);
 
-make_opts([{filter, F} | Rest], Detach, Extra, none, Tmo) ->
-    make_opts(Rest, Detach, Extra, F, Tmo);
-make_opts([{filter, F} | Rest], Detach, Extra, {all, Fs}, Tmo) ->
-    make_opts(Rest, Detach, Extra, {all, [F|Fs]}, Tmo);
-make_opts([{filter, F} | Rest], Detach, Extra, F0, Tmo) ->
-    make_opts(Rest, Detach, Extra, {all, [F0, F]}, Tmo);
+make_opts([{filter, F} | Rest], Peers, Detach, Extra, none, Tmo) ->
+    make_opts(Rest, Peers, Detach, Extra, F, Tmo);
+make_opts([{filter, F} | Rest], Peers, Detach, Extra, {all, Fs}, Tmo) ->
+    make_opts(Rest, Peers, Detach, Extra, {all, [F|Fs]}, Tmo);
+make_opts([{filter, F} | Rest], Peers, Detach, Extra, F0, Tmo) ->
+    make_opts(Rest, Peers, Detach, Extra, {all, [F0, F]}, Tmo);
 
-make_opts([{extra, L} | Rest], Detach, Extra, Filter, Tmo)
+make_opts([{extra, L} | Rest], Peers, Detach, Extra, Filter, Tmo)
   when is_list(L) ->
-    make_opts(Rest, Detach, Extra ++ L, Filter, Tmo);
+    make_opts(Rest, Peers, Detach, Extra ++ L, Filter, Tmo);
 
-make_opts([detach | Rest], _, Extra, Filter, Tmo) ->
-    make_opts(Rest, true, Extra, Filter, Tmo);
+make_opts([detach | Rest], Peers, _, Extra, Filter, Tmo) ->
+    make_opts(Rest, Peers, true, Extra, Filter, Tmo);
 
-make_opts([T | _], _, _, _, _) ->
+make_opts([{peer, TPid} | Rest], Peers, Detach, Extra, Filter, Tmo)
+  when is_pid(TPid) ->
+    make_opts(Rest, [TPid | Peers], Detach, Extra, Filter, Tmo);
+
+make_opts([T | _], _, _, _, _, _) ->
     ?ERROR({invalid_option, T}).
 
 %% ---------------------------------------------------------------------------
@@ -1654,8 +1660,8 @@ pick_peer(_, _, undefined, _) ->
 pick_peer(SvcName,
           AppOrAlias,
           Msg,
-          #options{filter = Filter, extra = Xtra}) ->
-    X = {fun(D) -> get_destination(D, Msg) end, Filter, Xtra},
+          #options{peers = TPids, filter = Filter, extra = Xtra}) ->
+    X = {fun(D) -> get_destination(D, Msg) end, Filter, Xtra, TPids},
     case diameter_service:pick_peer(SvcName, AppOrAlias, X) of
         false ->
             {error, no_connection};