Tell hypergridders when their teleports fail because of the 4096 limit rather than just saying "destination not found"

Instead of performing the 4096 check when the region is linked (and subsequently removing the link), leave the link in place and perform the check in the entity transfer module
This allows us to explicitly tell the hypergridder why the teleport failed (region out of range).
It also allows people on regions that are within range (on a large source grid) to teleport.
The Check4096 config parameter in the [GridService] section is replaced by a max_distance paramter in a new [EntityTransfer] section in OpenSimDefaults.ini
Since the parameter is in OpenSimDefaults.ini no action needs to be taken unless you want to increase this limit.  It could also be decreased.
The check is being made in the base entity transfer module, since I believe the viewer problem occurs both on extremely large grids and while hypergridding.

2 files changed, 47 insertions, 11 deletions

diff --git a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
index 1341533..d54216a 100644
--- a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
+++ b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
@@ -50,6 +50,11 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
     {
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
 
+        /// <summary>
+        /// The maximum distance, in standard region units (256m) that an agent is allowed to transfer.
+        /// </summary>
+        public int MaxTransferDistance { get; set; }
+
         protected bool m_Enabled = false;
         protected Scene m_aScene;
         protected List<Scene> m_Scenes = new List<Scene>();
@@ -78,13 +83,26 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                 string name = moduleConfig.GetString("EntityTransferModule", "");
                 if (name == Name)
                 {
-                    m_agentsInTransit = new List<UUID>();
-                    m_Enabled = true;
-                    m_log.InfoFormat("[ENTITY TRANSFER MODULE]: {0} enabled.", Name);
+                    InitialiseCommon(source);
+                    m_log.DebugFormat("[ENTITY TRANSFER MODULE]: {0} enabled.", Name);
                 }
             }
         }
 
+        /// <summary>
+        /// Initialize config common for this module and any descendents.
+        /// </summary>
+        /// <param name="source"></param>
+        protected virtual void InitialiseCommon(IConfigSource source)
+        {
+            IConfig transferConfig = source.Configs["EntityTransfer"];
+            if (transferConfig != null)
+                MaxTransferDistance = transferConfig.GetInt("max_distance", 4095);
+
+            m_agentsInTransit = new List<UUID>();
+            m_Enabled = true;
+        }
+
         public virtual void PostInitialise()
         {
         }
@@ -114,7 +132,6 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                 return;
         }
 
-
         public virtual void RemoveRegion(Scene scene)
         {
             if (!m_Enabled)
@@ -129,7 +146,6 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         {
             if (!m_Enabled)
                 return;
-
         }
 
         #endregion
@@ -204,8 +220,18 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                             sp.ControllingClient.SendTeleportFailed("Problem at destination");
                             return;
                         }
-                        m_log.DebugFormat("[ENTITY TRANSFER MODULE]: Final destination is x={0} y={1} {2}@{3}",
-                            finalDestination.RegionLocX / Constants.RegionSize, finalDestination.RegionLocY / Constants.RegionSize, finalDestination.RegionID, finalDestination.ServerURI);
+
+                        uint curX = 0, curY = 0;
+                        Utils.LongToUInts(sp.Scene.RegionInfo.RegionHandle, out curX, out curY);
+                        int curCellX = (int)(curX / Constants.RegionSize);
+                        int curCellY = (int)(curY / Constants.RegionSize);
+                        int destCellX = (int)(finalDestination.RegionLocX / Constants.RegionSize);
+                        int destCellY = (int)(finalDestination.RegionLocY / Constants.RegionSize);
+
+//                        m_log.DebugFormat("[ENTITY TRANSFER MODULE]: Source co-ords are x={0} y={1}", curRegionX, curRegionY);
+//
+//                        m_log.DebugFormat("[ENTITY TRANSFER MODULE]: Final dest is x={0} y={1} {2}@{3}",
+//                            destRegionX, destRegionY, finalDestination.RegionID, finalDestination.ServerURI);
 
                         // Check that these are not the same coordinates
                         if (finalDestination.RegionLocX == sp.Scene.RegionInfo.RegionLocX &&
@@ -216,6 +242,18 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                             return;
                         }
 
+                        if (Math.Abs(curCellX - destCellX) > MaxTransferDistance || Math.Abs(curCellY - destCellY) > MaxTransferDistance)
+                        {
+                            sp.ControllingClient.SendTeleportFailed(
+                                string.Format(
+                                  "Can't teleport to {0} ({1},{2}) from {3} ({4},{5}), destination is more than {6} regions way",
+                                  finalDestination.RegionName, destCellX, destCellY,
+                                  sp.Scene.RegionInfo.RegionName, curCellX, curCellY,
+                                  MaxTransferDistance));
+
+                            return;
+                        }
+
                         //
                         // This is it
                         //
diff --git a/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs b/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs
index 4d77ef4..a87279a 100644
--- a/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs
+++ b/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs
@@ -67,10 +67,8 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                 string name = moduleConfig.GetString("EntityTransferModule", "");
                 if (name == Name)
                 {
-                    m_agentsInTransit = new List<UUID>();
-                    
-                    m_Enabled = true;
-                    m_log.InfoFormat("[HG ENTITY TRANSFER MODULE]: {0} enabled.", Name);
+                    InitialiseCommon(source);
+                    m_log.DebugFormat("[HG ENTITY TRANSFER MODULE]: {0} enabled.", Name);
                 }
             }
         }