From 03408cbda8a6111c864f4515e1136608c4709fcd Mon Sep 17 00:00:00 2001
From: Charlie Groves <charlie@threerings.net>
Date: Sun, 5 Jul 2009 23:18:51 +0000
Subject: [PATCH] Don't allow the dummy DObject to be destroyed.  That
 shouldn't happen in the normal course of operations, but previously if
 someone called destroy on an uninitialized DObject or called
 PresentsDObjectManager.destroyObject with its oid, it'd be destroyed. 
 Subscribing to objects depends on that object existing, so if it's destroyed,
 the server will continue to function normally except that subscription
 requests will be silently dropped.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5851 542714f4-19e9-0310-aa3c-eee0fc999fb1
---
 .../com/threerings/presents/dobj/DObject.java |  4 ++++
 .../presents/server/PresentsDObjectMgr.java   | 21 ++++++++++++++++---
 .../presents/server/PresentsSession.java      |  2 +-
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/java/com/threerings/presents/dobj/DObject.java b/src/java/com/threerings/presents/dobj/DObject.java
index a2164047c..e793b388e 100644
--- a/src/java/com/threerings/presents/dobj/DObject.java
+++ b/src/java/com/threerings/presents/dobj/DObject.java
@@ -367,6 +367,10 @@ public class DObject
      */
     public void destroy ()
     {
+        if (_oid == 0) {
+            log.warning("Denying request to destroy an uninitialized object!", new Exception());
+            return;
+        }
         postEvent(new ObjectDestroyedEvent(_oid));
     }
 
diff --git a/src/java/com/threerings/presents/server/PresentsDObjectMgr.java b/src/java/com/threerings/presents/server/PresentsDObjectMgr.java
index ddb01e87a..8c657a1fc 100644
--- a/src/java/com/threerings/presents/server/PresentsDObjectMgr.java
+++ b/src/java/com/threerings/presents/server/PresentsDObjectMgr.java
@@ -96,9 +96,9 @@ public class PresentsDObjectMgr
     {
         // create a dummy object to live as oid zero and use that for some internal event trickery
         DObject dummy = new DObject();
-        dummy.setOid(0);
+        dummy.setOid(DUMMY_OID);
         dummy.setManager(this);
-        _objects.put(0, new DObject());
+        _objects.put(DUMMY_OID, new DObject());
 
         // register a couple of reports with the report manager
         repmgr.registerReporter(ReportManager.DEFAULT_TYPE, new ReportManager.Reporter() {
@@ -268,6 +268,10 @@ public class PresentsDObjectMgr
     // from interface RootDObjectManager
     public void destroyObject (int oid)
     {
+        if (oid == DUMMY_OID) {
+            log.warning("Denying request to destroy the dummy object!", new Exception());
+            return;
+        }
         // queue up an object destroyed event
         postEvent(new ObjectDestroyedEvent(oid));
     }
@@ -412,6 +416,11 @@ public class PresentsDObjectMgr
     {
         int oid = target.getOid();
 
+        if (oid == DUMMY_OID) {
+            log.warning("Denying attempt to destroy dummy object!", new Exception());
+            return false;
+        }
+
 //         log.info("Removing destroyed object from table", "oid", oid);
 
         // remove the object from the table
@@ -871,7 +880,7 @@ public class PresentsDObjectMgr
 
         public AccessObjectEvent (int oid, Subscriber<T> target, int action)
         {
-            super(0); // target the bogus object
+            super(DUMMY_OID); // target the bogus object
             _oid = oid;
             _target = target;
             _action = action;
@@ -1067,4 +1076,10 @@ public class PresentsDObjectMgr
 
     /** The default size of an oid list refs vector. */
     protected static final int DEFREFVEC_SIZE = 4;
+
+    /**
+     * The oid of the DOject created during object manager startup that isn't actually
+     * distributed.
+     */
+    protected static final int DUMMY_OID = 0;
 }
diff --git a/src/java/com/threerings/presents/server/PresentsSession.java b/src/java/com/threerings/presents/server/PresentsSession.java
index 2d40301f4..13da993b7 100644
--- a/src/java/com/threerings/presents/server/PresentsSession.java
+++ b/src/java/com/threerings/presents/server/PresentsSession.java
@@ -962,7 +962,7 @@ public class PresentsSession
         // from interface ProxySubscriber
         public void eventReceived (DEvent event)
         {
-            if (event instanceof PresentsDObjectMgr.AccessObjectEvent) {
+            if (event instanceof PresentsDObjectMgr.AccessObjectEvent<?>) {
                 log.warning("Ignoring event that shouldn't be forwarded " + event + ".",
                             new Exception());
                 return;