1 files changed, 86 insertions, 34 deletions

diff --git a/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs b/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs
index 545a0bc..74175d0 100644
--- a/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs
+++ b/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs
@@ -89,6 +89,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
     /// </summary>
     public class LLUDPServer : OpenSimUDPBase
     {
+        /// <summary>Maximum transmission unit, or UDP packet size, for the LLUDP protocol</summary>
+        public const int MTU = 1400;
+
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
 
         /// <summary>Handlers for incoming packets</summary>
@@ -104,7 +107,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// <summary>Manages authentication for agent circuits</summary>
         private AgentCircuitManager m_circuitManager;
         /// <summary>Reference to the scene this UDP server is attached to</summary>
-        private IScene m_scene;
+        private Scene m_scene;
         /// <summary>The X/Y coordinates of the scene this UDP server is attached to</summary>
         private Location m_location;
         /// <summary>The measured resolution of Environment.TickCount</summary>
@@ -181,15 +184,20 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
         public void AddScene(IScene scene)
         {
-            if (m_scene == null)
+            if (m_scene != null)
             {
-                m_scene = scene;
-                m_location = new Location(m_scene.RegionInfo.RegionHandle);
+                m_log.Error("[LLUDPSERVER]: AddScene() called on an LLUDPServer that already has a scene");
+                return;
             }
-            else
+
+            if (!(scene is Scene))
             {
-                m_log.Error("[LLUDPSERVER]: AddScene() called on an LLUDPServer that already has a scene");
+                m_log.Error("[LLUDPSERVER]: AddScene() called with an unrecognized scene type " + scene.GetType());
+                return;
             }
+
+            m_scene = (Scene)scene;
+            m_location = new Location(m_scene.RegionInfo.RegionHandle);
         }
 
         public bool HandlesRegion(Location x)
@@ -267,38 +275,54 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         {
             int dataLength = data.Length;
             bool doZerocode = (data[0] & Helpers.MSG_ZEROCODED) != 0;
+            bool doCopy = true;
 
             // Frequency analysis of outgoing packet sizes shows a large clump of packets at each end of the spectrum.
             // The vast majority of packets are less than 200 bytes, although due to asset transfers and packet splitting
             // there are a decent number of packets in the 1000-1140 byte range. We allocate one of two sizes of data here
             // to accomodate for both common scenarios and provide ample room for ACK appending in both
-            int bufferSize = (dataLength > 180) ? Packet.MTU : 200;
+            int bufferSize = (dataLength > 180) ? LLUDPServer.MTU : 200;
 
             UDPPacketBuffer buffer = new UDPPacketBuffer(udpClient.RemoteEndPoint, bufferSize);
 
             // Zerocode if needed
             if (doZerocode)
             {
-                try { dataLength = Helpers.ZeroEncode(data, dataLength, buffer.Data); }
+                try
+                {
+                    dataLength = Helpers.ZeroEncode(data, dataLength, buffer.Data);
+                    doCopy = false;
+                }
                 catch (IndexOutOfRangeException)
                 {
                     // The packet grew larger than the bufferSize while zerocoding.
                     // Remove the MSG_ZEROCODED flag and send the unencoded data
                     // instead
-                    m_log.Debug("[LLUDPSERVER]: Packet exceeded buffer size during zerocoding for " + type + ". Removing MSG_ZEROCODED flag");
+                    m_log.Debug("[LLUDPSERVER]: Packet exceeded buffer size during zerocoding for " + type + ". DataLength=" + dataLength +
+                        " and BufferLength=" + buffer.Data.Length + ". Removing MSG_ZEROCODED flag");
                     data[0] = (byte)(data[0] & ~Helpers.MSG_ZEROCODED);
-                    Buffer.BlockCopy(data, 0, buffer.Data, 0, dataLength);
                 }
             }
-            else
+
+            // If the packet data wasn't already copied during zerocoding, copy it now
+            if (doCopy)
             {
-                Buffer.BlockCopy(data, 0, buffer.Data, 0, dataLength);
+                if (dataLength <= buffer.Data.Length)
+                {
+                    Buffer.BlockCopy(data, 0, buffer.Data, 0, dataLength);
+                }
+                else
+                {
+                    m_log.Error("[LLUDPSERVER]: Packet exceeded buffer size! This could be an indication of packet assembly not obeying the MTU. Type=" +
+                        type + ", DataLength=" + dataLength + ", BufferLength=" + buffer.Data.Length + ". Dropping packet");
+                    return;
+                }
             }
+
             buffer.DataLength = dataLength;
 
             #region Queue or Send
 
-            // Look up the UDPClient this is going to
             OutgoingPacket outgoingPacket = new OutgoingPacket(udpClient, buffer, category);
 
             if (!outgoingPacket.Client.EnqueueOutgoing(outgoingPacket))
@@ -513,7 +537,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             IClientAPI client;
             if (!m_scene.ClientManager.TryGetValue(address, out client) || !(client is LLClientView))
             {
-                m_log.Warn("[LLUDPSERVER]: Received a " + packet.Type + " packet from an unrecognized source: " + address +
+                m_log.Debug("[LLUDPSERVER]: Received a " + packet.Type + " packet from an unrecognized source: " + address +
                     " in " + m_scene.RegionInfo.RegionName + ", currently tracking " + m_scene.ClientManager.Count + " clients");
                 return;
             }
@@ -553,6 +577,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     for (int i = 0; i < ackPacket.Packets.Length; i++)
                         AcknowledgePacket(udpClient, ackPacket.Packets[i].ID, now, packet.Header.Resent);
                 }
+
+                // We don't need to do anything else with PacketAck packets
+                return;
             }
 
             #endregion ACK Receiving
@@ -560,20 +587,22 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             #region ACK Sending
 
             if (packet.Header.Reliable)
+            {
                 udpClient.PendingAcks.Enqueue(packet.Header.Sequence);
 
-            // This is a somewhat odd sequence of steps to pull the client.BytesSinceLastACK value out,
-            // add the current received bytes to it, test if 2*MTU bytes have been sent, if so remove
-            // 2*MTU bytes from the value and send ACKs, and finally add the local value back to
-            // client.BytesSinceLastACK. Lockless thread safety
-            int bytesSinceLastACK = Interlocked.Exchange(ref udpClient.BytesSinceLastACK, 0);
-            bytesSinceLastACK += buffer.DataLength;
-            if (bytesSinceLastACK > Packet.MTU * 2)
-            {
-                bytesSinceLastACK -= Packet.MTU * 2;
-                SendAcks(udpClient);
+                // This is a somewhat odd sequence of steps to pull the client.BytesSinceLastACK value out,
+                // add the current received bytes to it, test if 2*MTU bytes have been sent, if so remove
+                // 2*MTU bytes from the value and send ACKs, and finally add the local value back to
+                // client.BytesSinceLastACK. Lockless thread safety
+                int bytesSinceLastACK = Interlocked.Exchange(ref udpClient.BytesSinceLastACK, 0);
+                bytesSinceLastACK += buffer.DataLength;
+                if (bytesSinceLastACK > LLUDPServer.MTU * 2)
+                {
+                    bytesSinceLastACK -= LLUDPServer.MTU * 2;
+                    SendAcks(udpClient);
+                }
+                Interlocked.Add(ref udpClient.BytesSinceLastACK, bytesSinceLastACK);
             }
-            Interlocked.Add(ref udpClient.BytesSinceLastACK, bytesSinceLastACK);
 
             #endregion ACK Sending
 
@@ -593,12 +622,28 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             #endregion Incoming Packet Accounting
 
-            // Don't bother clogging up the queue with PacketAck packets that are already handled here
-            if (packet.Type != PacketType.PacketAck)
+            #region Ping Check Handling
+
+            if (packet.Type == PacketType.StartPingCheck)
+            {
+                // We don't need to do anything else with ping checks
+                StartPingCheckPacket startPing = (StartPingCheckPacket)packet;
+
+                CompletePingCheckPacket completePing = new CompletePingCheckPacket();
+                completePing.PingID.PingID = startPing.PingID.PingID;
+                SendPacket(udpClient, completePing, ThrottleOutPacketType.Unknown, false);
+                return;
+            }
+            else if (packet.Type == PacketType.CompletePingCheck)
             {
-                // Inbox insertion
-                packetInbox.Enqueue(new IncomingPacket(udpClient, packet));
+                // We don't currently track client ping times
+                return;
             }
+
+            #endregion Ping Check Handling
+
+            // Inbox insertion
+            packetInbox.Enqueue(new IncomingPacket(udpClient, packet));
         }
 
         protected override void PacketSent(UDPPacketBuffer buffer, int bytesSent)
@@ -693,12 +738,19 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             // on to en-US to avoid number parsing issues
             Culture.SetCurrentCulture();
 
-            IncomingPacket incomingPacket = null;
-
             while (base.IsRunning)
             {
-                if (packetInbox.Dequeue(100, ref incomingPacket))
-                    Util.FireAndForget(ProcessInPacket, incomingPacket);
+                IncomingPacket incomingPacket = null;
+
+                try
+                {
+                    if (packetInbox.Dequeue(100, ref incomingPacket))
+                        Util.FireAndForget(ProcessInPacket, incomingPacket);
+                }
+                catch (Exception ex)
+                {
+                    m_log.Error("[LLUDPSERVER]: Error in the incoming packet handler loop: " + ex.Message, ex);
+                }
             }
 
             if (packetInbox.Count > 0)
@@ -747,7 +799,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     elapsed500MS = 0;
                 }
 
-                m_scene.ClientManager.ForEach(
+                m_scene.ClientManager.ForEachSync(
                     delegate(IClientAPI client)
                     {
                         if (client is LLClientView)