Extract our permission policy into a separate class so that a system can more

easily make use of different permission policies in different circumstances
(one can imagine a hypothetical partner who has different access control
requirements, perhaps).


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5118 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/crowd/data/BodyObject.java

@@ -24,10 +24,7 @@ package com.threerings.crowd.data;
 import com.threerings.util.Name;
 
 import com.threerings.presents.data.ClientObject;
-import com.threerings.presents.data.InvocationCodes;
-import com.threerings.presents.data.Permission;
 
-import com.threerings.crowd.chat.data.ChatCodes;
 import com.threerings.crowd.chat.data.SpeakObject;
 
 /**
@@ -137,18 +134,6 @@ public class BodyObject extends ClientObject
         setLocation(null);
     }
 
-    @Override // from ClientObject
-    public String checkAccess (Permission perm, Object context)
-    {
-        if (perm == ChatCodes.BROADCAST_ACCESS) {
-            return getTokens().isAdmin() ? null : ChatCodes.ACCESS_DENIED;
-        } else if (perm == ChatCodes.CHAT_ACCESS) {
-            return null;
-        } else {
-            return super.checkAccess(perm, context);
-        }
-    }
-
     // documentation inherited
     public void applyToListeners (ListenerOp op)
     {

src/java/com/threerings/crowd/data/CrowdPermissionPolicy.java

@@ -0,0 +1,51 @@
+//
+// $Id$
+//
+// Narya library - tools for developing networked games
+// Copyright (C) 2002-2008 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.crowd.data;
+
+import com.threerings.presents.data.ClientObject;
+import com.threerings.presents.data.Permission;
+import com.threerings.presents.data.PermissionPolicy;
+
+import com.threerings.crowd.chat.data.ChatCodes;
+
+/**
+ * Implements some Crowd permissions.
+ */
+public class CrowdPermissionPolicy extends PermissionPolicy
+{
+    @Override // from PermissionPolicy
+    public String checkAccess (ClientObject clobj, Permission perm, Object context)
+    {
+        if (!(clobj instanceof BodyObject)) {
+            return super.checkAccess(clobj, perm, context);
+        }
+
+        BodyObject body = (BodyObject)clobj;
+        if (perm == ChatCodes.BROADCAST_ACCESS) {
+            return body.getTokens().isAdmin() ? null : ACCESS_DENIED;
+        } else if (perm == ChatCodes.CHAT_ACCESS) {
+            return null;
+        } else {
+            return super.checkAccess(clobj, perm, context);
+        }
+    }
+}

src/java/com/threerings/crowd/data/TokenRing.java

@@ -26,12 +26,11 @@ import com.threerings.io.SimpleStreamableObject;
 /**
  * Defines access control tokens that convey certain privileges to users.
  *
- * @see BodyObject#checkAccess
+ * @see CrowdPermissionPolicy
  */
 public class TokenRing extends SimpleStreamableObject
 {
-    /** Indicates that this user is an administrator and can do things like broadcast, shutdown the
-     * server and whatnot. */
+    /** Indicates that this user is an administrator. */
     public static final int ADMIN = (1 << 0);
 
     /**

src/java/com/threerings/crowd/server/CrowdClientResolver.java

@@ -22,22 +22,30 @@
 package com.threerings.crowd.server;
 
 import com.threerings.presents.data.ClientObject;
+import com.threerings.presents.data.PermissionPolicy;
 import com.threerings.presents.server.ClientResolver;
 
 import com.threerings.crowd.data.BodyObject;
+import com.threerings.crowd.data.CrowdPermissionPolicy;
 
 /**
  * Used to configure crowd-specific client object data.
  */
 public class CrowdClientResolver extends ClientResolver
 {
-    // documentation inherited
+    @Override // from ClientResolver
     public ClientObject createClientObject ()
     {
         return new BodyObject();
     }
 
-    // documentation inherited
+    @Override // from ClientResolver
+    public PermissionPolicy createPermissionPolicy ()
+    {
+        return new CrowdPermissionPolicy();
+    }
+
+    @Override // from ClientResolver
     protected void resolveClientData (ClientObject clobj)
         throws Exception
     {

src/java/com/threerings/presents/data/ClientObject.java

@@ -44,6 +44,14 @@ public class ClientObject extends DObject
     /** Used to publish all invocation service receivers registered on this client. */
     public DSet<InvocationReceiver.Registration> receivers = DSet.newDSet();
 
+    /**
+     * Configures this client with a permissions policy. This is done during client resolution.
+     */
+    public void setPermissionPolicy (PermissionPolicy policy)
+    {
+        _permPolicy = policy;
+    }
+
     /**
      * Returns a short string identifying this client.
      */
@@ -53,16 +61,16 @@ public class ClientObject extends DObject
     }
 
     /**
-     * Checks whether or not this client has access to the specified feature. Forms the basis of an
-     * extensible fine-grained permissions system.
+     * Checks whether or not this client has access to the specified feature.
      *
      * @return null if the user has access, a fully-qualified translatable message string
-     * indicating the reason for denial of access (or just {@link InvocationCodes#ACCESS_DENIED} if
-     * you don't want to be specific).
+     * indicating the reason for denial of access.
+     *
+     * @see PermissionPolicy
      */
     public String checkAccess (Permission feature, Object context)
     {
-        return InvocationCodes.ACCESS_DENIED;
+        return _permPolicy.checkAccess(this, feature, context);
     }
 
     /**
@@ -148,6 +156,9 @@ public class ClientObject extends DObject
     }
     // AUTO-GENERATED: METHODS END
 
+    /** Handles our fine-grained permissions. */
+    protected PermissionPolicy _permPolicy;
+
     /** Used to reference count resolved client objects. */
     protected transient int _references;
 }

src/java/com/threerings/presents/data/PermissionPolicy.java

@@ -0,0 +1,44 @@
+//
+// $Id$
+//
+// Narya library - tools for developing networked games
+// Copyright (C) 2002-2008 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.data;
+
+import com.threerings.io.Streamable;
+
+/**
+ * Encapsulates a fine-grained permissions policy. The default policy is to deny access to
+ * everything, systems using fine-grained permissions should create a custom policy and provide it
+ * at client resolution time via the ClientResolver.
+ */
+public class PermissionPolicy
+    implements Streamable, InvocationCodes
+{
+    /**
+     * Returns null if the specified client has the specified permission, an error code explaining
+     * the lack of access if they do not. {@link InvocationCodes#ACCESS_DENIED} should be returned
+     * if no more specific explanation is available.
+     */
+    public String checkAccess (ClientObject clobj, Permission perm, Object context)
+    {
+        // by default, you can't do it!
+        return ACCESS_DENIED;
+    }
+}

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

@@ -268,8 +268,9 @@ public class ClientManager
             final ClientResolver fclr = clr;
             PresentsServer.omgr.postRunnable(new Runnable() {
                 public void run () {
-                    fclr.objectAvailable(
-                        PresentsServer.omgr.registerObject(fclr.createClientObject()));
+                    ClientObject clobj = fclr.createClientObject();
+                    clobj.setPermissionPolicy(fclr.createPermissionPolicy());
+                    fclr.objectAvailable(PresentsServer.omgr.registerObject(clobj));
                 }
             });
 

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

@@ -28,6 +28,7 @@ import com.threerings.util.Name;
 
 import com.threerings.presents.Log;
 import com.threerings.presents.data.ClientObject;
+import com.threerings.presents.data.PermissionPolicy;
 import com.threerings.presents.dobj.DObject;
 import com.threerings.presents.dobj.ObjectAccessException;
 
@@ -66,6 +67,14 @@ public class ClientResolver extends Invoker.Unit
         return new ClientObject();
     }
 
+    /**
+     * Creates a permission policy for use by our client.
+     */
+    public PermissionPolicy createPermissionPolicy ()
+    {
+        return new PermissionPolicy();
+    }
+
     /**
      * Called once our client object is registered with the distributed object system.
      */