Set incoming_only flag on the host side when NAT traversal is disabled.

remoting/protocol/transport_config.h

Index: remoting/protocol/transport_config.h
diff --git a/remoting/protocol/transport_config.h b/remoting/protocol/transport_config.h
index 7599bf65813e3123bd37a17669c1a45e48650eb9..e6c73a4d3e2edb31c9a64c388a1379772d873025 100644
--- a/remoting/protocol/transport_config.h
+++ b/remoting/protocol/transport_config.h
@@ -14,7 +14,20 @@ struct TransportConfig {
   TransportConfig();
   ~TransportConfig();
 
-  bool nat_traversal;
+  enum NatTraversalMode {

[Wez, 2012/03/01 19:36:35]

nit: Is a single enum the best way to express this, versus separate "NAT
traversal" and "initiator" flags?

[Sergey Ulanov, 2012/03/01 20:48:29]

Yes, I considered two separate flags, but incoming_only flag doesn't make sense
with NAT traversal enabled. You can't use STUN/relay servers if you are not
allowed to connect to them.

+    // Don't use STUN or relay servers and don't make any outgoing
+    // connections. Note that connection will always fail if both ends

[Wez, 2012/03/01 19:36:35]

nit: "outgoing" is a little confusing in a p2p context.  What we're saying is
that we will respond to incoming p2p channel connection attempts, but not
initiate any ourselves.

[Sergey Ulanov, 2012/03/01 20:48:29]

Done.

+    // use this mode.
+    NAT_TRAVERSAL_DISABLED,
+
+    // Don't use STUN or relay servers but make outgoing connections.
+    NAT_TRAVERSAL_PASSIVE,

[Wez, 2012/03/01 19:36:35]

nit: It's not really "passive" if you make an outgoing connection; perhaps
"client"/"disabled_client" or "outgoing"?

[Wez, 2012/03/01 19:36:35]

We don't actually use PASSIVE right now, so perhaps it's best not to have it at
all?

[Sergey Ulanov, 2012/03/01 20:48:29]

It's not used anywhere right now, but it might be useful in the future.

[Sergey Ulanov, 2012/03/01 20:48:29]

It is passive in terms of not actively trying to traverse NAT. Changed to
OUTGOING, though it seems confusing as well.

+
+    // Active NAT traversal using STUN and relay servers.
+    NAT_TRAVERSAL_ENABLED,
+  };
+
+  NatTraversalMode nat_traversal_mode;
   std::string stun_server;
   std::string relay_server;
   std::string relay_token;