From c74b1c4a46c71bd3b258477ca4bf1b5d39c5095e Mon Sep 17 00:00:00 2001
From: Anders Svensson <anders@erlang.org>
Date: Thu, 13 Apr 2017 10:26:36 +0200
Subject: Let candidate peers be passed to diameter:call/4

To solve the problem of being able to send messages to a peer that
hasn't advertised support for the application in question, as discussed
in the parent commit. diameter:call/4 can be passed 'peer' options to
identify candidates, and the only requirement is that an appropriate
dictionary be configured for encode. Filters are applied as if
candidates had been selected by advertised application.
---
 lib/diameter/src/base/diameter_traffic.erl | 44 +++++++++++++++++-------------
 1 file changed, 25 insertions(+), 19 deletions(-)

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

diff --git a/lib/diameter/src/base/diameter_traffic.erl b/lib/diameter/src/base/diameter_traffic.erl
index 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};
-- 
cgit v1.2.3