some cleanup and assume Linux/mono DNS is just broken...

OpenSim/Framework/Util.cs

@@ -1009,6 +1009,9 @@ namespace OpenSim.Framework
         public static IPAddress GetHostFromDNS(string dnsAddress)
         {
             // If it is already an IP, avoid possible broken mono from seeing it 
+            if(String.IsNullOrWhiteSpace(dnsAddress))
+                return null;
+
             IPAddress ia = null;
             if (IPAddress.TryParse(dnsAddress, out ia) && ia != null)
             {
@@ -1016,11 +1019,22 @@ namespace OpenSim.Framework
                     return null;
                 return ia;
             }
-            // Reset for next check
+
-            ia = null;
+            IPHostEntry IPH;
             try
             {
-                foreach (IPAddress Adr in Dns.GetHostAddresses(dnsAddress))
+                IPH = Dns.GetHostEntry(dnsAddress);
+            }
+            catch // (SocketException e)
+            {
+                    return null;
+            }
+
+            if(IPH == null || IPH.AddressList.Length == 0)
+                return null;
+
+            ia = null;
+            foreach (IPAddress Adr in IPH.AddressList)
             {
                 if (ia == null)
                     ia = Adr;
@@ -1031,17 +1045,6 @@ namespace OpenSim.Framework
                     break;
                 }
             }
-            }
-            catch // (SocketException e)
-            {
-                /*throw new Exception(
-                    "Unable to resolve local hostname " + m_externalHostName + " innerException of type '" +
-                    e + "' attached to this exception", e);*/
-                // Don't throw a fatal exception here, instead, return Null and handle it in the caller.
-                // Reason is, on systems such as OSgrid it has occured that known hostnames stop
-                // resolving and thus make surrounding regions crash out with this exception.
-                return null;
-            }
             return ia;
         }
 
@@ -1076,11 +1079,21 @@ namespace OpenSim.Framework
                 return getEndPoint(ia, port);
             }
             
-            // Reset for next check
+            IPHostEntry IPH;
-            ia = null;
             try
             {
-                foreach (IPAddress Adr in Dns.GetHostAddresses(hostname))
+                IPH = Dns.GetHostEntry(hostname);
+            }
+            catch // (SocketException e)
+            {
+                    return null;
+            }
+
+            if(IPH == null || IPH.AddressList.Length == 0)
+                return null;
+
+            ia = null;
+            foreach (IPAddress Adr in IPH.AddressList)
             {
                 if (ia == null)
                     ia = Adr;
@@ -1091,11 +1104,6 @@ namespace OpenSim.Framework
                     break;
                 }
             }
-            }
-            catch // (SocketException e)
-            {
-                    ia = null;
-            }
 
             return getEndPoint(ia,port);
         }

OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs

@@ -157,7 +157,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                     m_idCache = new ExpiringCache<ulong, DateTime>();
                     m_bannedRegions.Add(pAgentID, m_idCache, TimeSpan.FromSeconds(newTime));
                 }
-                m_idCache.Add(pRegionHandle, DateTime.UtcNow + TimeSpan.FromSeconds(extendTime), TimeSpan.FromSeconds(extendTime));
+                m_idCache.Add(pRegionHandle, DateTime.UtcNow + TimeSpan.FromSeconds(extendTime), extendTime);
             }
 
             // Remove the agent from the region's banned list
@@ -1488,13 +1488,11 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                                 Math.Max(scene.RegionInfo.RegionSizeX, scene.RegionInfo.RegionSizeY));
 
             if (neighbourRegion == null)
-            {
-                failureReason = "no region found"; // debug -> to remove
                 return null;
-            }
+
             if (m_bannedRegionCache.IfBanned(neighbourRegion.RegionHandle, agentID))
             {
-                failureReason = "Access Denied";
+                failureReason = "Access Denied or Temporary not possible";
                 return null;
             }
 
@@ -1513,6 +1511,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             {
                 // remember the fail
                 m_bannedRegionCache.Add(neighbourRegion.RegionHandle, agentID);
+                if(String.IsNullOrWhiteSpace(failureReason))
                     failureReason = "Access Denied";
                 return null;
             }
@@ -2171,7 +2170,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                                     InformClientOfNeighbourAsync(sp, cagents[count], neighbour, ipe, true);
                                 else
                                 {
-                                    m_log.DebugFormat("[ENTITY TRANSFER MODULE]: DNS for neighbour {0} lost", neighbour.ExternalHostName);
+                                    m_log.DebugFormat("[ENTITY TRANSFER MODULE]:  lost DNS resolution for neighbour {0}", neighbour.ExternalHostName);
                                 }
                                 count++;
                             }

OpenSim/Services/Connectors/Hypergrid/UserAgentServiceConnector.cs

@@ -70,10 +70,15 @@ namespace OpenSim.Services.Connectors.Hypergrid
                 {
                     Uri m_Uri = new Uri(m_ServerURL);
                     IPAddress ip = Util.GetHostFromDNS(m_Uri.Host);
+                    if(ip != null)
+                    {
                         m_ServerURL = m_ServerURL.Replace(m_Uri.Host, ip.ToString());
                         if (!m_ServerURL.EndsWith("/"))
                             m_ServerURL += "/";
                     }
+                    else
+                        m_log.DebugFormat("[USER AGENT CONNECTOR]: Failed to resolv address of {0}", url);
+                }
                 catch (Exception e)
                 {
                     m_log.DebugFormat("[USER AGENT CONNECTOR]: Malformed Uri {0}: {1}", url, e.Message);