/* * Copyright (c) Contributors, http://opensimulator.org/ * See CONTRIBUTORS.TXT for a full list of copyright holders. * * 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. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of the OpenSim Project 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 DEVELOPERS ``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 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.Collections; using System.Collections.Generic; using System.Net; using System.Net.Sockets; using System.Threading; using System.Timers; using System.Reflection; using OpenMetaverse; using OpenMetaverse.Packets; using Timer = System.Timers.Timer; using OpenSim.Framework; using OpenSim.Region.ClientStack.LindenUDP; using log4net; namespace OpenSim.Region.ClientStack.LindenUDP { public delegate void PacketStats(int inPackets, int outPackets, int unAckedBytes); public delegate void PacketDrop(Packet pack, Object id); public delegate bool SynchronizeClientHandler(IScene scene, Packet packet, UUID agentID, ThrottleOutPacketType throttlePacketType); public interface IPacketHandler { event PacketStats OnPacketStats; event PacketDrop OnPacketDrop; SynchronizeClientHandler SynchronizeClient { set; } int PacketsReceived { get; } int PacketsReceivedReported { get; } uint ResendTimeout { get; set; } bool ReliableIsImportant { get; set; } int MaxReliableResends { get; set; } void InPacket(Packet packet); void ProcessInPacket(LLQueItem item); void ProcessOutPacket(LLQueItem item); void OutPacket(Packet NewPack, ThrottleOutPacketType throttlePacketType); void OutPacket(Packet NewPack, ThrottleOutPacketType throttlePacketType, Object id); LLPacketQueue PacketQueue { get; } void Stop(); void Flush(); void Clear(); ClientInfo GetClientInfo(); void SetClientInfo(ClientInfo info); void AddImportantPacket(PacketType type); void RemoveImportantPacket(PacketType type); } public class LLPacketHandler : IPacketHandler { //private static readonly ILog m_log // = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType); //private int m_resentCount; // Packet queues // LLPacketQueue m_PacketQueue; public LLPacketQueue PacketQueue { get { return m_PacketQueue; } } // Timer to run stats and acks on // private Timer m_AckTimer = new Timer(250); // A list of the packets we haven't acked yet // private Dictionary m_PendingAcks = new Dictionary(); private Dictionary m_NeedAck = new Dictionary(); /// /// The number of milliseconds that can pass before a packet that needs an ack is resent. /// private uint m_ResendTimeout = 4000; public uint ResendTimeout { get { return m_ResendTimeout; } set { m_ResendTimeout = value; } } private int m_MaxReliableResends = 3; public int MaxReliableResends { get { return m_MaxReliableResends; } set { m_MaxReliableResends = value; } } // Track duplicated packets. This uses a Dictionary. Both insertion // and lookup are common operations and need to take advantage of // the hashing. Expiration is less common and can be allowed the // time for a linear scan. // private Dictionary m_DupeTracker = new Dictionary(); private uint m_DupeTrackerWindow = 30; private int m_DupeTrackerLastCheck = System.Environment.TickCount; // Values for the SimStatsReporter // private int m_PacketsReceived = 0; private int m_PacketsReceivedReported = 0; private int m_PacketsSent = 0; private int m_PacketsSentReported = 0; private int m_UnackedBytes = 0; private int m_LastResend = 0; public int PacketsReceived { get { return m_PacketsReceived; } } public int PacketsReceivedReported { get { return m_PacketsReceivedReported; } } // The client we are working for // private IClientAPI m_Client; // Some events // public event PacketStats OnPacketStats; public event PacketDrop OnPacketDrop; private SynchronizeClientHandler m_SynchronizeClient = null; public SynchronizeClientHandler SynchronizeClient { set { m_SynchronizeClient = value; } } // Packet sequencing // private uint m_Sequence = 0; private object m_SequenceLock = new object(); private const int MAX_SEQUENCE = 0xFFFFFF; // Packet dropping // List m_ImportantPackets = new List(); private bool m_ReliableIsImportant = false; public bool ReliableIsImportant { get { return m_ReliableIsImportant; } set { m_ReliableIsImportant = value; } } private int m_DropSafeTimeout; LLPacketServer m_PacketServer; private byte[] m_ZeroOutBuffer = new byte[4096]; //////////////////////////////////////////////////////////////////// // Constructors // public LLPacketHandler(IClientAPI client, LLPacketServer server, ClientStackUserSettings userSettings) { m_Client = client; m_PacketServer = server; m_DropSafeTimeout = System.Environment.TickCount + 15000; m_PacketQueue = new LLPacketQueue(client.AgentId, userSettings); m_AckTimer.Elapsed += AckTimerElapsed; m_AckTimer.Start(); } public void Stop() { m_AckTimer.Stop(); m_PacketQueue.Enqueue(null); m_PacketQueue.Close(); m_Client = null; } // Send one packet. This actually doesn't send anything, it queues // it. Designed to be fire-and-forget, but there is an optional // notifier. // public void OutPacket( Packet packet, ThrottleOutPacketType throttlePacketType) { OutPacket(packet, throttlePacketType, null); } public void OutPacket( Packet packet, ThrottleOutPacketType throttlePacketType, Object id) { // Call the load balancer's hook. If this is not active here // we defer to the sim server this client is actually connected // to. Packet drop notifies will not be triggered in this // configuration! // if ((m_SynchronizeClient != null) && (!m_Client.IsActive)) { if (m_SynchronizeClient(m_Client.Scene, packet, m_Client.AgentId, throttlePacketType)) return; } packet.Header.Sequence = 0; lock (m_NeedAck) { DropResend(id); AddAcks(ref packet); QueuePacket(packet, throttlePacketType, id); } } private void AddAcks(ref Packet packet) { // These packet types have shown to have issues with // acks being appended to the payload, just don't send // any with them until libsl is fixed. // if (packet is OpenMetaverse.Packets.ViewerEffectPacket) return; if (packet is OpenMetaverse.Packets.SimStatsPacket) return; // Add acks to outgoing packets // if (m_PendingAcks.Count > 0) { int count = m_PendingAcks.Count; if (count > 10) count = 10; packet.Header.AckList = new uint[count]; packet.Header.AppendedAcks = true; int i = 0; foreach (uint ack in new List(m_PendingAcks.Keys)) { packet.Header.AckList[i] = ack; i++; m_PendingAcks.Remove(ack); if (i >= count) // That is how much space there is break; } } } private void QueuePacket( Packet packet, ThrottleOutPacketType throttlePacketType, Object id) { LLQueItem item = new LLQueItem(); item.Packet = packet; item.Incoming = false; item.throttleType = throttlePacketType; item.TickCount = System.Environment.TickCount; item.Identifier = id; item.Resends = 0; item.Length = packet.ToBytes().Length; m_PacketQueue.Enqueue(item); m_PacketsSent++; } private void ResendUnacked() { int now = System.Environment.TickCount; int intervalMs = 250; if (m_LastResend != 0) intervalMs = now - m_LastResend; lock (m_NeedAck) { if (m_DropSafeTimeout > now || intervalMs > 500) // We were frozen! { foreach (LLQueItem data in new List (m_NeedAck.Values)) { if (m_DropSafeTimeout > now) { m_NeedAck[data.Packet.Header.Sequence]. TickCount = now; } else { m_NeedAck[data.Packet.Header.Sequence]. TickCount += intervalMs; } } } } m_LastResend = now; // Unless we have received at least one ack, don't bother resending // anything. There may not be a client there, don't clog up the // pipes. // lock (m_NeedAck) { // Nothing to do // if (m_NeedAck.Count == 0) return; int resent = 0; foreach (LLQueItem data in new List(m_NeedAck.Values)) { Packet packet = data.Packet; // Packets this old get resent // if ((now - data.TickCount) > m_ResendTimeout) { if (resent < 20) { m_NeedAck[packet.Header.Sequence].Resends++; // The client needs to be told that a packet is being resent, otherwise it appears to believe // that it should reset its sequence to that packet number. packet.Header.Resent = true; if ((m_NeedAck[packet.Header.Sequence].Resends >= m_MaxReliableResends) && (!m_ReliableIsImportant)) { m_NeedAck.Remove(packet.Header.Sequence); TriggerOnPacketDrop(packet, data.Identifier); PacketPool.Instance.ReturnPacket(packet); continue; } m_NeedAck[packet.Header.Sequence].TickCount = System.Environment.TickCount; QueuePacket(packet, ThrottleOutPacketType.Resend, data.Identifier); resent++; } else { m_NeedAck[packet.Header.Sequence].TickCount += intervalMs; } } } } } // Send the pending packet acks to the client // Will send blocks of acks for up to 250 packets // private void SendAcks() { lock (m_NeedAck) { if (m_PendingAcks.Count == 0) return; PacketAckPacket acks = (PacketAckPacket)PacketPool.Instance.GetPacket(PacketType.PacketAck); // The case of equality is more common than one might think, // because this function will be called unconditionally when // the counter reaches 250. So there is a good chance another // packet with 250 blocks exists. // if (acks.Packets == null || acks.Packets.Length != m_PendingAcks.Count) acks.Packets = new PacketAckPacket.PacketsBlock[m_PendingAcks.Count]; int i = 0; foreach (uint ack in new List(m_PendingAcks.Keys)) { acks.Packets[i] = new PacketAckPacket.PacketsBlock(); acks.Packets[i].ID = ack; m_PendingAcks.Remove(ack); i++; } acks.Header.Reliable = false; OutPacket(acks, ThrottleOutPacketType.Unknown); } } // Queue a packet ack. It will be sent either after 250 acks are // queued, or when the timer fires. // private void AckPacket(Packet packet) { lock (m_NeedAck) { if (m_PendingAcks.Count < 250) { if (!m_PendingAcks.ContainsKey(packet.Header.Sequence)) m_PendingAcks.Add(packet.Header.Sequence, packet.Header.Sequence); return; } } SendAcks(); lock (m_NeedAck) { // If this is still full we have a truly exceptional // condition (means, can't happen) // if (m_PendingAcks.Count < 250) { if (!m_PendingAcks.ContainsKey(packet.Header.Sequence)) m_PendingAcks.Add(packet.Header.Sequence, packet.Header.Sequence); return; } } } // When the timer elapses, send the pending acks, trigger resends // and report all the stats. // private void AckTimerElapsed(object sender, ElapsedEventArgs ea) { SendAcks(); ResendUnacked(); SendPacketStats(); } // Push out pachet counts for the sim status reporter // private void SendPacketStats() { PacketStats handlerPacketStats = OnPacketStats; if (handlerPacketStats != null) { handlerPacketStats( m_PacketsReceived - m_PacketsReceivedReported, m_PacketsSent - m_PacketsSentReported, m_UnackedBytes); m_PacketsReceivedReported = m_PacketsReceived; m_PacketsSentReported = m_PacketsSent; } } // We can't keep an unlimited record of dupes. This will prune the // dictionary by age. // private void PruneDupeTracker() { lock (m_DupeTracker) { if (m_DupeTracker.Count < 1024) return; if (System.Environment.TickCount - m_DupeTrackerLastCheck < 2000) return; m_DupeTrackerLastCheck = System.Environment.TickCount; Dictionary packs = new Dictionary(m_DupeTracker); foreach (uint pack in packs.Keys) { if (Util.UnixTimeSinceEpoch() - m_DupeTracker[pack] > m_DupeTrackerWindow) m_DupeTracker.Remove(pack); } } } public void InPacket(Packet packet) { if (packet == null) return; // If this client is on another partial instance, no need // to handle packets // if (!m_Client.IsActive && packet.Type != PacketType.LogoutRequest) { PacketPool.Instance.ReturnPacket(packet); return; } // Any packet can have some packet acks in the header. // Process them here // if (packet.Header.AppendedAcks) { foreach (uint id in packet.Header.AckList) { ProcessAck(id); } } // When too many acks are needed to be sent, the client sends // a packet consisting of acks only // if (packet.Type == PacketType.PacketAck) { PacketAckPacket ackPacket = (PacketAckPacket)packet; foreach (PacketAckPacket.PacketsBlock block in ackPacket.Packets) { ProcessAck(block.ID); } PacketPool.Instance.ReturnPacket(packet); return; } else if (packet.Type == PacketType.StartPingCheck) { StartPingCheckPacket startPing = (StartPingCheckPacket)packet; CompletePingCheckPacket endPing = (CompletePingCheckPacket)PacketPool.Instance.GetPacket(PacketType.CompletePingCheck); endPing.PingID.PingID = startPing.PingID.PingID; OutPacket(endPing, ThrottleOutPacketType.Task); } else { LLQueItem item = new LLQueItem(); item.Packet = packet; item.Incoming = true; m_PacketQueue.Enqueue(item); } } public void ProcessInPacket(LLQueItem item) { Packet packet = item.Packet; // Always ack the packet! // if (packet.Header.Reliable) AckPacket(packet); if (packet.Type != PacketType.AgentUpdate) m_PacketsReceived++; PruneDupeTracker(); // Check for duplicate packets.. packets that the client is // resending because it didn't receive our ack // lock (m_DupeTracker) { if (m_DupeTracker.ContainsKey(packet.Header.Sequence)) return; m_DupeTracker.Add(packet.Header.Sequence, Util.UnixTimeSinceEpoch()); } m_Client.ProcessInPacket(packet); } public void Flush() { m_PacketQueue.Flush(); m_UnackedBytes = (-1 * m_UnackedBytes); SendPacketStats(); } public void Clear() { m_UnackedBytes = (-1 * m_UnackedBytes); SendPacketStats(); m_NeedAck.Clear(); m_PendingAcks.Clear(); m_Sequence += 1000000; } private void ProcessAck(uint id) { LLQueItem data; lock (m_NeedAck) { //m_log.DebugFormat("[CLIENT]: In {0} received ack for packet {1}", m_Client.Scene.RegionInfo.ExternalEndPoint.Port, id); if (!m_NeedAck.TryGetValue(id, out data)) return; m_NeedAck.Remove(id); PacketPool.Instance.ReturnPacket(data.Packet); m_UnackedBytes -= data.Length; } } // Allocate packet sequence numbers in a threadsave manner // protected uint NextPacketSequenceNumber() { // Set the sequence number uint seq = 1; lock (m_SequenceLock) { if (m_Sequence >= MAX_SEQUENCE) { m_Sequence = 1; } else { m_Sequence++; } seq = m_Sequence; } return seq; } public ClientInfo GetClientInfo() { ClientInfo info = new ClientInfo(); info.pendingAcks = m_PendingAcks; info.needAck = new Dictionary(); lock (m_NeedAck) { foreach (uint key in m_NeedAck.Keys) info.needAck.Add(key, m_NeedAck[key].Packet.ToBytes()); } LLQueItem[] queitems = m_PacketQueue.GetQueueArray(); for (int i = 0; i < queitems.Length; i++) { if (queitems[i].Incoming == false) info.out_packets.Add(queitems[i].Packet.ToBytes()); } info.sequence = m_Sequence; return info; } public void SetClientInfo(ClientInfo info) { m_PendingAcks = info.pendingAcks; m_NeedAck = new Dictionary(); Packet packet = null; int packetEnd = 0; byte[] zero = new byte[3000]; foreach (uint key in info.needAck.Keys) { byte[] buff = info.needAck[key]; packetEnd = buff.Length - 1; try { packet = PacketPool.Instance.GetPacket(buff, ref packetEnd, zero); } catch (Exception) { } LLQueItem item = new LLQueItem(); item.Packet = packet; item.Incoming = false; item.throttleType = 0; item.TickCount = System.Environment.TickCount; item.Identifier = 0; item.Resends = 0; item.Length = packet.ToBytes().Length; m_NeedAck.Add(key, item); } m_Sequence = info.sequence; } public void AddImportantPacket(PacketType type) { if (m_ImportantPackets.Contains(type)) return; m_ImportantPackets.Add(type); } public void RemoveImportantPacket(PacketType type) { if (!m_ImportantPackets.Contains(type)) return; m_ImportantPackets.Remove(type); } private void DropResend(Object id) { foreach (LLQueItem data in new List(m_NeedAck.Values)) { if (data.Identifier != null && data.Identifier == id) { m_NeedAck.Remove(data.Packet.Header.Sequence); PacketPool.Instance.ReturnPacket(data.Packet); return; } } } private void TriggerOnPacketDrop(Packet packet, Object id) { PacketDrop handlerPacketDrop = OnPacketDrop; if (handlerPacketDrop == null) return; handlerPacketDrop(packet, id); } // Convert the packet to bytes and stuff it onto the send queue // public void ProcessOutPacket(LLQueItem item) { Packet packet = item.Packet; // Assign sequence number here to prevent out of order packets if (packet.Header.Sequence == 0) { packet.Header.Sequence = NextPacketSequenceNumber(); lock (m_NeedAck) { // We want to see that packet arrive if it's reliable if (packet.Header.Reliable) { m_UnackedBytes += item.Length; // Keep track of when this packet was sent out item.TickCount = System.Environment.TickCount; m_NeedAck[packet.Header.Sequence] = item; } } } // If we sent a killpacket if (packet is KillPacket) Abort(); // Actually make the byte array and send it byte[] sendbuffer = item.Packet.ToBytes(); //m_log.DebugFormat( // "[CLIENT]: In {0} sending packet {1}", // m_Client.Scene.RegionInfo.ExternalEndPoint.Port, packet.Header.Sequence); if (packet.Header.Zerocoded) { int packetsize = Helpers.ZeroEncode(sendbuffer, sendbuffer.Length, m_ZeroOutBuffer); m_PacketServer.SendPacketTo(m_ZeroOutBuffer, packetsize, SocketFlags.None, m_Client.CircuitCode); } else { // Need some extra space in case we need to add proxy // information to the message later Buffer.BlockCopy(sendbuffer, 0, m_ZeroOutBuffer, 0, sendbuffer.Length); m_PacketServer.SendPacketTo(m_ZeroOutBuffer, sendbuffer.Length, SocketFlags.None, m_Client.CircuitCode); } // If this is a reliable packet, we are still holding a ref // Dont't return in that case // if (!packet.Header.Reliable) PacketPool.Instance.ReturnPacket(packet); } private void Abort() { m_PacketQueue.Close(); Thread.CurrentThread.Abort(); } } }