Move some low-level object access control into Presents from Crowd (default all

objects to non-modifiable, restrict client object subscriptions to the client
in question). Modified Peer code to not log a warning when a peer is not online
in an expected way (not listening for connections).


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4598 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/presents/server/PresentsObjectAccess.java

@@ -0,0 +1,99 @@
+//
+// $Id$
+//
+// Narya library - tools for developing networked games
+// Copyright (C) 2002-2006 Three Rings Design, Inc., All Rights Reserved
+// http://www.threerings.net/code/narya/
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.threerings.presents.server;
+
+import com.threerings.presents.Log;
+import com.threerings.presents.data.ClientObject;
+import com.threerings.presents.dobj.AccessController;
+import com.threerings.presents.dobj.DEvent;
+import com.threerings.presents.dobj.DObject;
+import com.threerings.presents.dobj.InvocationRequestEvent;
+import com.threerings.presents.dobj.MessageEvent;
+import com.threerings.presents.dobj.NamedEvent;
+import com.threerings.presents.dobj.Subscriber;
+
+/**
+ * Defines the various object access controllers used by the Presents server.
+ */
+public class PresentsObjectAccess
+{
+    /**
+     * Our default access controller. Disallows modification of any object but allows anyone to
+     * subscribe.
+     */
+    public static AccessController DEFAULT = new AccessController()
+    {
+        // documentation inherited from interface
+        public boolean allowSubscribe (DObject object, Subscriber subscriber)
+        {
+            // allow anyone to subscribe
+            return true;
+        }
+
+        // documentation inherited from interface
+        public boolean allowDispatch (DObject object, DEvent event)
+        {
+            // if the event came from the server, it's cool
+            if (event.getSourceOid() == -1) {
+                return true;
+
+            } else {
+                // if it came from the client, it better be a non-modification event
+                return (event instanceof MessageEvent || event instanceof InvocationRequestEvent);
+            }
+        }
+    };
+
+    /**
+     * Provides access control for client objects.
+     */
+    public static AccessController CLIENT = new AccessController()
+    {
+        // documentation inherited from interface
+        public boolean allowSubscribe (DObject object, Subscriber sub)
+        {
+            boolean allowed = true;
+            // if the subscriber is a client, ensure that they are this same user
+            if (sub instanceof PresentsClient) {
+                allowed = ((PresentsClient)sub).getClientObject() == object;
+                if (!allowed) {
+                    Log.warning("Refusing ClientObject subscription request " +
+                                "[obj=" + ((ClientObject)object).who() + ", sub=" + sub + "].");
+                }
+            }
+            return allowed;
+        }
+
+        // documentation inherited from interface
+        public boolean allowDispatch (DObject object, DEvent event)
+        {
+            // if the event came from the server, it's cool
+            if (event.getSourceOid() == -1) {
+                return true;
+            }
+
+            // the client is only allowed to modify the RECEIVERS field
+            return ((event instanceof NamedEvent) &&
+                    ((NamedEvent)event).getName().equals(ClientObject.RECEIVERS));
+        }
+    };
+}