Better handling of invalid XML: a) prevent infinite loop on EOF; b) better logging

If the XML was truncated for some reason then ExecuteReadProcessors() would get into an infinite loop, using high CPU. Now it detects EOF (and several other error cases) and aborts.

The rest of the changes just improve logging of XML in case of errors, so that we can see what the bad XML is.

1 files changed, 56 insertions, 53 deletions

diff --git a/OpenSim/Region/Framework/Scenes/Serialization/SceneObjectSerializer.cs b/OpenSim/Region/Framework/Scenes/Serialization/SceneObjectSerializer.cs
index 463ef22..4caa9cb 100644
--- a/OpenSim/Region/Framework/Scenes/Serialization/SceneObjectSerializer.cs
+++ b/OpenSim/Region/Framework/Scenes/Serialization/SceneObjectSerializer.cs
@@ -62,8 +62,20 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
         {
             String fixedData = ExternalRepresentationUtils.SanitizeXml(xmlData);
             using (XmlTextReader wrappedReader = new XmlTextReader(fixedData, XmlNodeType.Element, null))
+            {
                 using (XmlReader reader = XmlReader.Create(wrappedReader, new XmlReaderSettings() { IgnoreWhitespace = true, ConformanceLevel = ConformanceLevel.Fragment }))
-                    return FromOriginalXmlFormat(reader);
+                {
+                    try {
+                        return FromOriginalXmlFormat(reader);
+                    }
+                    catch (Exception e)
+                    {
+                        m_log.Error("[SERIALIZER]: Deserialization of xml failed ", e);
+                        Util.LogFailedXML("[SERIALIZER]:", fixedData);
+                        return null;
+                    }
+                }
+            }
         }
 
         /// <summary>
@@ -76,43 +88,33 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
             //m_log.DebugFormat("[SOG]: Starting deserialization of SOG");
             //int time = System.Environment.TickCount;
 
-            SceneObjectGroup sceneObject = null;
+            int linkNum;
 
-            try
-            {
-                int           linkNum;
+            reader.ReadToFollowing("RootPart");
+            reader.ReadToFollowing("SceneObjectPart");
+            SceneObjectGroup sceneObject = new SceneObjectGroup(SceneObjectPart.FromXml(reader));
+            reader.ReadToFollowing("OtherParts");
 
-                reader.ReadToFollowing("RootPart");
-                reader.ReadToFollowing("SceneObjectPart");
-                sceneObject = new SceneObjectGroup(SceneObjectPart.FromXml(reader));
-                reader.ReadToFollowing("OtherParts");
-
-                if (reader.ReadToDescendant("Part"))
+            if (reader.ReadToDescendant("Part"))
+            {
+                do
                 {
-                    do
+                    if (reader.ReadToDescendant("SceneObjectPart"))
                     {
-                        if (reader.ReadToDescendant("SceneObjectPart"))
-                        {
-                            SceneObjectPart part = SceneObjectPart.FromXml(reader);
-                            linkNum = part.LinkNum;
-                            sceneObject.AddPart(part);
-                            part.LinkNum = linkNum;
-                            part.TrimPermissions();
-                        }
-                    }                    
-                    while (reader.ReadToNextSibling("Part"));
-                }
-
-                // Script state may, or may not, exist. Not having any, is NOT
-                // ever a problem.
-                sceneObject.LoadScriptState(reader);
-            }
-            catch (Exception e)
-            {
-                m_log.ErrorFormat("[SERIALIZER]: Deserialization of xml failed.  Exception {0}", e);
-                return null;
+                        SceneObjectPart part = SceneObjectPart.FromXml(reader);
+                        linkNum = part.LinkNum;
+                        sceneObject.AddPart(part);
+                        part.LinkNum = linkNum;
+                        part.TrimPermissions();
+                    }
+                }                    
+                while (reader.ReadToNextSibling("Part"));
             }
 
+            // Script state may, or may not, exist. Not having any, is NOT
+            // ever a problem.
+            sceneObject.LoadScriptState(reader);
+
             return sceneObject;
         }
 
@@ -236,7 +238,8 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
 
                 if (parts.Count == 0)
                 {
-                    m_log.ErrorFormat("[SERIALIZER]: Deserialization of xml failed: No SceneObjectPart nodes. xml was " + xmlData);
+                    m_log.Error("[SERIALIZER]: Deserialization of xml failed: No SceneObjectPart nodes");
+                    Util.LogFailedXML("[SERIALIZER]:", xmlData);
                     return null;
                 }
 
@@ -280,7 +283,8 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
             }
             catch (Exception e)
             {
-                m_log.ErrorFormat("[SERIALIZER]: Deserialization of xml failed with {0}.  xml was {1}", e, xmlData);
+                m_log.Error("[SERIALIZER]: Deserialization of xml failed ", e);
+                Util.LogFailedXML("[SERIALIZER]:", xmlData);
                 return null;
             }
         }
@@ -708,7 +712,7 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
         private static void ProcessShape(SceneObjectPart obj, XmlReader reader)
         {
             List<string> errorNodeNames;
-            obj.Shape = ReadShape(reader, "Shape", out errorNodeNames);
+            obj.Shape = ReadShape(reader, "Shape", out errorNodeNames, obj);
 
             if (errorNodeNames != null)
             {
@@ -1599,18 +1603,21 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
 
             reader.ReadStartElement("SceneObjectPart");
 
-            ExternalRepresentationUtils.ExecuteReadProcessors(
+            bool errors = ExternalRepresentationUtils.ExecuteReadProcessors(
                 obj,
                 m_SOPXmlProcessors,
                 reader,
-                (o, nodeName, e)
-                    => m_log.DebugFormat(
-                        "[SceneObjectSerializer]: Exception while parsing {0} in object {1} {2}: {3}{4}",
-                        ((SceneObjectPart)o).Name, ((SceneObjectPart)o).UUID, nodeName, e.Message, e.StackTrace));
+                (o, nodeName, e) => {
+                    m_log.Debug(string.Format("[SceneObjectSerializer]: Error while parsing element {0} in object {1} {2} ",
+                        nodeName, ((SceneObjectPart)o).Name, ((SceneObjectPart)o).UUID), e);
+                });
+
+            if (errors)
+                throw new XmlException(string.Format("Error parsing object {0} {1}", obj.Name, obj.UUID));
 
             reader.ReadEndElement(); // SceneObjectPart
 
-            //m_log.DebugFormat("[XXX]: parsed SOP {0} - {1}", obj.Name, obj.UUID);
+            // m_log.DebugFormat("[SceneObjectSerializer]: parsed SOP {0} {1}", obj.Name, obj.UUID);
             return obj;
         }
 
@@ -1655,7 +1662,7 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
         /// <param name="name">The name of the xml element containing the shape</param>
         /// <param name="errors">a list containing the failing node names.  If no failures then null.</param>
         /// <returns>The shape parsed</returns>
-        public static PrimitiveBaseShape ReadShape(XmlReader reader, string name, out List<string> errorNodeNames)
+        public static PrimitiveBaseShape ReadShape(XmlReader reader, string name, out List<string> errorNodeNames, SceneObjectPart obj)
         {
             List<string> internalErrorNodeNames = null;
 
@@ -1674,18 +1681,14 @@ namespace OpenSim.Region.Framework.Scenes.Serialization
                 shape,
                 m_ShapeXmlProcessors,
                 reader,
-                (o, nodeName, e)
-                    =>
-                    {
-//                        m_log.DebugFormat(
-//                            "[SceneObjectSerializer]: Exception while parsing Shape property {0}: {1}{2}",
-//                            nodeName, e.Message, e.StackTrace);
-                        if (internalErrorNodeNames == null)
-                            internalErrorNodeNames = new List<string>();
+                (o, nodeName, e) => {
+                    m_log.Debug(string.Format("[SceneObjectSerializer]: Error while parsing element {0} in Shape property of object {1} {2} ",
+                        nodeName, obj.Name, obj.UUID), e);
 
-                        internalErrorNodeNames.Add(nodeName);
-                    }
-            );
+                    if (internalErrorNodeNames == null)
+                            internalErrorNodeNames = new List<string>();
+                    internalErrorNodeNames.Add(nodeName);
+                });
 
             reader.ReadEndElement(); // Shape