Respect Host-IP-Address configuration

Addresses returned from a transport module were always used to populate
Host-IP-Address AVP's in an outgoing CER/CEA, which precluded the
sending of a VIP address. Transport addresses are now only used if
Host-IP-Address is unspecified.

In other words, respect any configured Host-IP-Address, regardless of
the physical addresses returned by the transport. To use the physical
addresses, don't configure Host-IP-Address.

2 files changed, 15 insertions, 15 deletions

diff --git a/lib/diameter/doc/src/diameter_transport.xml b/lib/diameter/doc/src/diameter_transport.xml
index 8bccf6521e..9161bd1f48 100644
--- a/lib/diameter/doc/src/diameter_transport.xml
+++ b/lib/diameter/doc/src/diameter_transport.xml
@@ -137,15 +137,14 @@ passed to the former.</p>
 
 <p>
 The start function should use the <c>Host-IP-Address</c> list in
-<c>Svc</c> and/or <c>Config</c> to select an appropriate list of local
-IP addresses, and should return this list if different from the
-<c>Svc</c> addresses.
+<c>Svc</c> and/or <c>Config</c> to select and return an appropriate
+list of local IP addresses.
 In the connecting case, the local address list can instead be
 communicated in a <c>connected</c> message (see &MESSAGES; below)
 following connection establishment.
 In either case, the local address list is used to populate
 <c>Host-IP-Address</c> AVPs in outgoing capabilities exchange
-messages.</p>
+messages if <c>Host-IP-Address</c> is unspecified.</p>
 
 <p>
 A transport process must implement the message interface documented below.
diff --git a/lib/diameter/src/base/diameter_peer_fsm.erl b/lib/diameter/src/base/diameter_peer_fsm.erl
index 6be4259510..2f0f0a7781 100644
--- a/lib/diameter/src/base/diameter_peer_fsm.erl
+++ b/lib/diameter/src/base/diameter_peer_fsm.erl
@@ -233,20 +233,21 @@ start_transport(Addrs0, T) ->
         {TPid, Addrs, Tmo, Data} ->
             erlang:monitor(process, TPid),
             q_next(TPid, Addrs0, Tmo, Data),
-            {TPid, addrs(Addrs, Addrs0)};
+            {TPid, Addrs};
         No ->
             exit({shutdown, No})
     end.
 
-addrs([], Addrs0) ->
-    Addrs0;
-addrs(Addrs, _) ->
-    Addrs.
-
-svc(Svc, []) ->
-    Svc;
-svc(Svc, Addrs) ->
-    readdr(Svc, Addrs).
+svc(#diameter_service{capabilities = LCaps0} = Svc, Addrs) ->
+    #diameter_caps{host_ip_address = Addrs0}
+        = LCaps0,
+    case Addrs0 of
+        [] ->
+            LCaps = LCaps0#diameter_caps{host_ip_address = Addrs},
+            Svc#diameter_service{capabilities = LCaps};
+        [_|_] ->
+            Svc
+    end.
 
 readdr(#diameter_service{capabilities = LCaps0} = Svc, Addrs) ->
     LCaps = LCaps0#diameter_caps{host_ip_address = Addrs},
@@ -360,7 +361,7 @@ transition({diameter, {TPid, connected, Remote, LAddrs}},
                   service = Svc}
            = S) ->
     transition({diameter, {TPid, connected, Remote}},
-               S#state{service = readdr(Svc, LAddrs)});
+               S#state{service = svc(Svc, LAddrs)});
 
 %% Connection from peer.
 transition({diameter, {TPid, connected}},