1 files changed, 280 insertions, 0 deletions

diff --git a/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs b/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs
new file mode 100644
index 0000000..d2779ba
--- /dev/null
+++ b/OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs
@@ -0,0 +1,280 @@
+/*
+ * Copyright (c) 2006, Clutch, Inc.
+ * Original Author: Jeff Cesnik
+ * All rights reserved.
+ *
+ * - Redistribution and use in source and binary forms, with or without 
+ *   modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ * - Neither the name of the openmetaverse.org nor the names 
+ *   of its contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using log4net;
+
+namespace OpenMetaverse
+{
+    /// <summary>
+    /// Base UDP server
+    /// </summary>
+    public abstract class OpenSimUDPBase
+    {
+        private static readonly ILog m_log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+
+        /// <summary>
+        /// This method is called when an incoming packet is received
+        /// </summary>
+        /// <param name="buffer">Incoming packet buffer</param>
+        protected abstract void PacketReceived(UDPPacketBuffer buffer);
+
+        /// <summary>UDP port to bind to in server mode</summary>
+        protected int m_udpPort;
+
+        /// <summary>Local IP address to bind to in server mode</summary>
+        protected IPAddress m_localBindAddress;
+
+        /// <summary>UDP socket, used in either client or server mode</summary>
+        private Socket m_udpSocket;
+
+        /// <summary>Flag to process packets asynchronously or synchronously</summary>
+        private bool m_asyncPacketHandling;
+
+        /// <summary>The all important shutdown flag</summary>
+        private volatile bool m_shutdownFlag = true;
+
+        /// <summary>Returns true if the server is currently listening, otherwise false</summary>
+        public bool IsRunning { get { return !m_shutdownFlag; } }
+
+        /// <summary>
+        /// Default constructor
+        /// </summary>
+        /// <param name="bindAddress">Local IP address to bind the server to</param>
+        /// <param name="port">Port to listening for incoming UDP packets on</param>
+        public OpenSimUDPBase(IPAddress bindAddress, int port)
+        {
+            m_localBindAddress = bindAddress;
+            m_udpPort = port;
+        }
+
+        /// <summary>
+        /// Start the UDP server
+        /// </summary>
+        /// <param name="recvBufferSize">The size of the receive buffer for 
+        /// the UDP socket. This value is passed up to the operating system 
+        /// and used in the system networking stack. Use zero to leave this
+        /// value as the default</param>
+        /// <param name="asyncPacketHandling">Set this to true to start
+        /// receiving more packets while current packet handler callbacks are
+        /// still running. Setting this to false will complete each packet
+        /// callback before the next packet is processed</param>
+        /// <remarks>This method will attempt to set the SIO_UDP_CONNRESET flag
+        /// on the socket to get newer versions of Windows to behave in a sane
+        /// manner (not throwing an exception when the remote side resets the
+        /// connection). This call is ignored on Mono where the flag is not
+        /// necessary</remarks>
+        public void Start(int recvBufferSize, bool asyncPacketHandling)
+        {
+            m_asyncPacketHandling = asyncPacketHandling;
+
+            if (m_shutdownFlag)
+            {
+                const int SIO_UDP_CONNRESET = -1744830452;
+
+                IPEndPoint ipep = new IPEndPoint(m_localBindAddress, m_udpPort);
+
+                m_udpSocket = new Socket(
+                    AddressFamily.InterNetwork,
+                    SocketType.Dgram,
+                    ProtocolType.Udp);
+
+                try
+                {
+                    // This udp socket flag is not supported under mono, 
+                    // so we'll catch the exception and continue
+                    m_udpSocket.IOControl(SIO_UDP_CONNRESET, new byte[] { 0 }, null);
+                    m_log.Debug("[UDPBASE]: SIO_UDP_CONNRESET flag set");
+                }
+                catch (SocketException)
+                {
+                    m_log.Debug("[UDPBASE]: SIO_UDP_CONNRESET flag not supported on this platform, ignoring");
+                }
+
+                if (recvBufferSize != 0)
+                    m_udpSocket.ReceiveBufferSize = recvBufferSize;
+
+                m_udpSocket.Bind(ipep);
+
+                // we're not shutting down, we're starting up
+                m_shutdownFlag = false;
+
+                // kick off an async receive.  The Start() method will return, the
+                // actual receives will occur asynchronously and will be caught in
+                // AsyncEndRecieve().
+                AsyncBeginReceive();
+            }
+        }
+
+        /// <summary>
+        /// Stops the UDP server
+        /// </summary>
+        public void Stop()
+        {
+            if (!m_shutdownFlag)
+            {
+                // wait indefinitely for a writer lock.  Once this is called, the .NET runtime
+                // will deny any more reader locks, in effect blocking all other send/receive
+                // threads.  Once we have the lock, we set shutdownFlag to inform the other
+                // threads that the socket is closed.
+                m_shutdownFlag = true;
+                m_udpSocket.Close();
+            }
+        }
+
+        private void AsyncBeginReceive()
+        {
+            // allocate a packet buffer
+            //WrappedObject<UDPPacketBuffer> wrappedBuffer = Pool.CheckOut();
+            UDPPacketBuffer buf = new UDPPacketBuffer();
+
+            if (!m_shutdownFlag)
+            {
+                try
+                {
+                    // kick off an async read
+                    m_udpSocket.BeginReceiveFrom(
+                        //wrappedBuffer.Instance.Data,
+                        buf.Data,
+                        0,
+                        UDPPacketBuffer.BUFFER_SIZE,
+                        SocketFlags.None,
+                        ref buf.RemoteEndPoint,
+                        AsyncEndReceive,
+                        //wrappedBuffer);
+                        buf);
+                }
+                catch (SocketException e)
+                {
+                    if (e.SocketErrorCode == SocketError.ConnectionReset)
+                    {
+                        m_log.Warn("[UDPBASE]: SIO_UDP_CONNRESET was ignored, attempting to salvage the UDP listener on port " + m_udpPort);
+                        bool salvaged = false;
+                        while (!salvaged)
+                        {
+                            try
+                            {
+                                m_udpSocket.BeginReceiveFrom(
+                                    //wrappedBuffer.Instance.Data,
+                                    buf.Data,
+                                    0,
+                                    UDPPacketBuffer.BUFFER_SIZE,
+                                    SocketFlags.None,
+                                    ref buf.RemoteEndPoint,
+                                    AsyncEndReceive,
+                                    //wrappedBuffer);
+                                    buf);
+                                salvaged = true;
+                            }
+                            catch (SocketException) { }
+                            catch (ObjectDisposedException) { return; }
+                        }
+
+                        m_log.Warn("[UDPBASE]: Salvaged the UDP listener on port " + m_udpPort);
+                    }
+                }
+                catch (ObjectDisposedException) { }
+            }
+        }
+
+        private void AsyncEndReceive(IAsyncResult iar)
+        {
+            // Asynchronous receive operations will complete here through the call
+            // to AsyncBeginReceive
+            if (!m_shutdownFlag)
+            {
+                // Asynchronous mode will start another receive before the
+                // callback for this packet is even fired. Very parallel :-)
+                if (m_asyncPacketHandling)
+                    AsyncBeginReceive();
+
+                // get the buffer that was created in AsyncBeginReceive
+                // this is the received data
+                //WrappedObject<UDPPacketBuffer> wrappedBuffer = (WrappedObject<UDPPacketBuffer>)iar.AsyncState;
+                //UDPPacketBuffer buffer = wrappedBuffer.Instance;
+                UDPPacketBuffer buffer = (UDPPacketBuffer)iar.AsyncState;
+
+                try
+                {
+                    // get the length of data actually read from the socket, store it with the
+                    // buffer
+                    buffer.DataLength = m_udpSocket.EndReceiveFrom(iar, ref buffer.RemoteEndPoint);
+
+                    // call the abstract method PacketReceived(), passing the buffer that
+                    // has just been filled from the socket read.
+                    PacketReceived(buffer);
+                }
+                catch (SocketException) { }
+                catch (ObjectDisposedException) { }
+                finally
+                {
+                    //wrappedBuffer.Dispose();
+
+                    // Synchronous mode waits until the packet callback completes
+                    // before starting the receive to fetch another packet
+                    if (!m_asyncPacketHandling)
+                        AsyncBeginReceive();
+                }
+
+            }
+        }
+
+        public void AsyncBeginSend(UDPPacketBuffer buf)
+        {
+            if (!m_shutdownFlag)
+            {
+                try
+                {
+                    m_udpSocket.BeginSendTo(
+                        buf.Data,
+                        0,
+                        buf.DataLength,
+                        SocketFlags.None,
+                        buf.RemoteEndPoint,
+                        AsyncEndSend,
+                        buf);
+                }
+                catch (SocketException) { }
+                catch (ObjectDisposedException) { }
+            }
+        }
+
+        void AsyncEndSend(IAsyncResult result)
+        {
+            try
+            {
+//                UDPPacketBuffer buf = (UDPPacketBuffer)result.AsyncState;
+                m_udpSocket.EndSendTo(result);
+            }
+            catch (SocketException) { }
+            catch (ObjectDisposedException) { }
+        }
+    }
+}