Further parse bunches till their channel receives them

src/Prospect.Unreal/Core/Names/UnrealConstants.cs

@@ -0,0 +1,6 @@
+namespace Prospect.Unreal.Core.Names;
+
+public class UnrealConstants
+{
+    public const int IndexNone = -1;
+}

src/Prospect.Unreal/Net/Channels/EChannelType.cs

@@ -1,13 +1,11 @@
 namespace Prospect.Unreal.Net.Channels;
 
-public static class EChannelType
+public enum EChannelType
 {
-    public const int CHTYPE_None = 0; // Invalid type.
+    CHTYPE_None = 0, // Invalid type.
-    public const int CHTYPE_Control = 1; // Connection control.
+    CHTYPE_Control = 1, // Connection control.
-    public const int CHTYPE_Actor = 2; // Actor-update channel.
+    CHTYPE_Actor = 2, // Actor-update channel.
-
+    CHTYPE_File = 3, // Binary file transfer.
-    public const int CHTYPE_File = 3; // Binary file transfer.
+    CHTYPE_Voice = 4, // VoIP data channel
-
+    CHTYPE_MAX = 8, // Maximum.
-    public const int CHTYPE_Voice = 4; // VoIP data channel
-    public const int CHTYPE_MAX = 8; // Maximum.
 }

src/Prospect.Unreal/Net/Channels/UActorChannel.cs

@@ -0,0 +1,21 @@
+using Prospect.Unreal.Core.Names;
+using Prospect.Unreal.Net.Packets.Bunch;
+
+namespace Prospect.Unreal.Net.Channels;
+
+public class UActorChannel : UChannel
+{
+    public UActorChannel()
+    {
+        ChType = EChannelType.CHTYPE_Actor;
+        ChName = UnrealNames.FNames[UnrealNameKey.Actor];
+        // bClearRecentActorRefs = true;
+        // bHoldQueuedExportBunchesAndGUIDs = false;
+        // QueuedCloseReason = EChannelCloseReason::Destroyed;
+    }
+
+    protected override void ReceivedBunch(FInBunch bunch)
+    {
+        throw new NotImplementedException();
+    }
+}

src/Prospect.Unreal/Net/Channels/UChannel.cs

@@ -0,0 +1,513 @@
+using Prospect.Unreal.Core.Names;
+using Prospect.Unreal.Exceptions;
+using Prospect.Unreal.Net.Packets.Bunch;
+using Serilog;
+
+namespace Prospect.Unreal.Net.Channels;
+
+public abstract class UChannel
+{
+    private static readonly ILogger Logger = Log.ForContext<UChannel>();
+    
+    private const int NetMaxConstructedPartialBunchSizeBytes = 1024 * 64;
+
+    /// <summary>
+    ///     Owner connection.
+    /// </summary>
+    public UNetConnection Connection { get; set; }
+
+    /// <summary>
+    ///     If OpenedLocally is true, this means we have acknowledged the packet we sent the bOpen bunch on.
+    ///     Otherwise, it means we have received the bOpen bunch from the server.
+    /// </summary>
+    public bool OpenAcked { get; set; }
+
+    /// <summary>
+    ///     State of the channel.
+    /// </summary>
+    public bool Closing { get; set; }
+
+    /// <summary>
+    ///     Channel is going dormant (it will close but the client will not destroy).
+    /// </summary>
+    public bool Dormant { get; set; }
+
+    /// <summary>
+    ///     Replication is being paused, but channel will not be closed.
+    /// </summary>
+    public bool bIsReplicationPaused { get; set; }
+
+    /// <summary>
+    ///     Opened temporarily.
+    /// </summary>
+    public bool OpenTemporary { get; set; }
+
+    /// <summary>
+    ///     Has encountered errors and is ignoring subsequent packets.
+    /// </summary>
+    public bool Broken { get; set; }
+
+    /// <summary>
+    ///     Actor associated with this channel was torn off.
+    /// </summary>
+    public bool bTornOff { get; set; }
+
+    /// <summary>
+    ///     Channel wants to go dormant (it will check during tick if it can go dormant).
+    /// </summary>
+    public bool bPendingDormancy { get; set; }
+
+    /// <summary>
+    ///     Channel wants to go dormant, and is otherwise ready to become dormant, but is waiting for a timeout before doing so.
+    /// </summary>
+    public bool bIsInDormancyHysteresis { get; set; }
+
+    /// <summary>
+    ///     Unreliable property replication is paused until all reliables are ack'd.
+    /// </summary>
+    public bool bPausedUntilReliableACK { get; set; }
+
+    /// <summary>
+    ///     Set when sending closing bunch to avoid recursion in send-failure-close case.
+    /// </summary>
+    public bool SentClosingBunch { get; set; }
+
+    /// <summary>
+    ///     Set when placed in the actor channel pool
+    /// </summary>
+    public bool bPooled { get; set; }
+
+    /// <summary>
+    ///     Whether channel was opened locally or by remote.
+    /// </summary>
+    public bool OpenedLocally { get; set; }
+
+    /// <summary>
+    ///     Whether channel was opened by replay checkpoint recording
+    /// </summary>
+    public bool bOpenedForCheckpoint { get; set; }
+
+    /// <summary>
+    ///     Index of this channel.
+    /// </summary>
+    public int ChIndex { get; set; }
+
+    /// <summary>
+    ///     If OpenedLocally is true, this is the packet we sent the bOpen bunch on.
+    ///     Otherwise, it's the packet we received the bOpen bunch on.
+    /// </summary>
+    public FPacketIdRange OpenPacketId { get; set; }
+
+    /// <summary>
+    ///     Type of this channel.
+    /// </summary>
+    public EChannelType ChType { get; set; }
+
+    /// <summary>
+    ///     Name of the type of this channel.
+    /// </summary>
+    public FName ChName { get; set; }
+
+    /// <summary>
+    ///     Number of packets in InRec.
+    /// </summary>
+    public int NumInRec { get; set; }
+
+    /// <summary>
+    ///     Number of packets in OutRec.
+    /// </summary>
+    public int NumOutRec { get; set; }
+
+    /// <summary>
+    ///     Incoming data with queued dependencies.
+    /// </summary>
+    public FInBunch? InRec { get; set; }
+
+    // public FOutBunch OutRec { get; set; }
+
+    /// <summary>
+    ///     Partial bunch we are receiving (incoming partial bunches are appended to this).
+    /// </summary>
+    public FInBunch? InPartialBunch { get; set; }
+
+    public virtual void Init(UNetConnection inConnection, int inChIndex, EChannelCreateFlags createFlags)
+    {
+        Connection = inConnection;
+        ChIndex = inChIndex;
+        OpenedLocally = (createFlags & EChannelCreateFlags.OpenedLocally) != 0;
+        OpenPacketId = new FPacketIdRange();
+        bPausedUntilReliableACK = false;
+        SentClosingBunch = false;
+    }
+
+    public void ReceivedRawBunch(FInBunch bunch, out bool bOutSkipAck)
+    {
+        bOutSkipAck = false;
+
+        // Immediately consume the NetGUID portion of this bunch, regardless if it is partial or reliable.
+        // NOTE - For replays, we do this even earlier, to try and load this as soon as possible, in case there is an issue creating the channel
+        // If a replay fails to create a channel, we want to salvage as much as possible
+        if (bunch.bHasPackageMapExports && !Connection.IsInternalAck())
+        {
+            throw new NotImplementedException();
+        }
+
+        if (Connection.IsInternalAck() && Broken)
+        {
+            return;
+        }
+
+        if (bunch.bReliable && bunch.ChSequence != Connection.InReliable[ChIndex] + 1)
+        {
+            if (Connection.IsInternalAck())
+            {
+                throw new UnrealNetException("Shouldn't hit this path on 100% reliable connections");
+            }
+
+            if (bunch.ChSequence <= Connection.InReliable[ChIndex])
+            {
+                throw new UnrealNetException("Invalid bunch");
+            }
+
+            // TODO: (InRec) Queue
+            throw new NotImplementedException();
+        }
+        else
+        {
+            var bDeleted = ReceivedNextBunch(bunch, out bOutSkipAck);
+
+            if (bunch.IsError())
+            {
+                Logger.Error("Bunch.IsError() after ReceivedNextBunch 1");
+                return;
+            }
+
+            if (bDeleted)
+            {
+                return;
+            }
+            
+            // TODO: (InRec) Dispatch waiting bunches
+            while (InRec != null)
+            {
+                throw new NotImplementedException();
+            }
+        }
+    }
+
+    private bool ReceivedNextBunch(FInBunch bunch, out bool bOutSkipAck)
+    {
+        bOutSkipAck = false;
+        
+        // We received the next bunch. Basically at this point:
+        //	-We know this is in order if reliable
+        //	-We dont know if this is partial or not
+        // If its not a partial bunch, of it completes a partial bunch, we can call ReceivedSequencedBunch to actually handle it
+
+        // Note this bunch's retirement.
+        if (bunch.bReliable)
+        {
+            // Reliables should be ordered properly at this point
+            if (bunch.ChSequence != Connection.InReliable[bunch.ChIndex] + 1)
+            {
+                throw new UnrealNetException("Reliables should be ordered properly at this point");
+            }
+
+            Connection.InReliable[bunch.ChIndex] = bunch.ChSequence;
+        }
+
+        var handleBunch = bunch;
+        
+        if (bunch.bPartial)
+        {
+            handleBunch = null;
+            
+            if (bunch.bPartialInitial)
+            {
+                // Create new InPartialBunch if this is the initial bunch of a new sequence.
+                if (InPartialBunch != null)
+                {
+                    if (!InPartialBunch.bPartialFinal)
+                    {
+                        if (InPartialBunch.bReliable)
+                        {
+                            if (bunch.bReliable)
+                            {
+                                Logger.Warning("Reliable partial trying to destroy reliable partial 1");
+                                bunch.SetError();
+                                return false;
+                            }
+                            
+                            Logger.Information("Unreliable partial trying to destroy reliable partial 1");
+                            bOutSkipAck = true;
+                            return false;
+                        }
+                        
+                        // We didn't complete the last partial bunch - this isn't fatal since they can be unreliable, but may want to log it.
+                        Logger.Verbose("Incomplete partial bunch. Channel: {ChIndex} ChSequence: {ChSequence}", InPartialBunch.ChIndex, InPartialBunch.ChSequence);
+                    }
+
+                    InPartialBunch = null;
+                }
+                
+                InPartialBunch = new FInBunch(bunch, false);
+
+                if (!bunch.bHasPackageMapExports && bunch.GetBitsLeft() > 0)
+                {
+                    if (bunch.GetBitsLeft() % 8 != 0)
+                    {
+                        Logger.Warning("Corrupt partial bunch. Initial partial bunches are expected to be byte-aligned. BitsLeft = {BitCount}", bunch.GetBitsLeft());
+                        bunch.SetError();
+                        return false;
+                    }
+
+                    InPartialBunch.AppendDataFromChecked(bunch.GetBufferPosChecked(), bunch.GetBuffer(), bunch.GetBitsLeft());
+                    
+                    Log.Verbose("Received new partial bunch");
+                }
+                else
+                {
+                    Log.Verbose("Received New partial bunch. It only contained NetGUIDs");
+                }
+            }
+            else
+            {
+                // Merge in next partial bunch to InPartialBunch if:
+                //	-We have a valid InPartialBunch
+                //	-The current InPartialBunch wasn't already complete
+                //  -ChSequence is next in partial sequence
+                //	-Reliability flag matches
+
+                var bSequenceMatches = false;
+                
+                if (InPartialBunch != null)
+                {
+                    var bReliableSequencesMatches = bunch.ChSequence == InPartialBunch.ChSequence + 1;
+                    var bUnreliableSequenceMatches = bReliableSequencesMatches || bunch.ChSequence == InPartialBunch.ChSequence;
+                    
+                    // Unreliable partial bunches use the packet sequence, and since we can merge multiple bunches into a single packet,
+                    // it's perfectly legal for the ChSequence to match in this case.
+                    // Reliable partial bunches must be in consecutive order though
+                    bSequenceMatches = InPartialBunch.bReliable ? bReliableSequencesMatches : bUnreliableSequenceMatches;
+                }
+
+                if (InPartialBunch != null && !InPartialBunch.bPartialFinal && bSequenceMatches && InPartialBunch.bReliable == bunch.bReliable)
+                {
+                    // Merge.
+                    Logger.Verbose("Merging Partial Bunch: {BytesLeft} Bytes", bunch.GetBytesLeft());
+
+                    if (!bunch.bHasPackageMapExports && bunch.GetBitsLeft() > 0)
+                    {
+                        // TODO: Check if works.
+                        InPartialBunch.AppendDataFromChecked(bunch.GetBufferPosChecked(), bunch.GetBuffer(), bunch.GetBitsLeft());
+                    }
+                    
+                    // Only the final partial bunch should ever be non byte aligned. This is enforced during partial bunch creation
+                    // This is to ensure fast copies/appending of partial bunches. The final partial bunch may be non byte aligned.
+                    if (!bunch.bHasPackageMapExports && !bunch.bPartialFinal && bunch.GetBitsLeft() % 8 != 0)
+                    {
+                        Logger.Warning("Corrupt partial bunch. Non-final partial bunches are expected to be byte-aligned. bHasPackageMapExports = {HasPackageMapExports}, bPartialFinal = {PartialFinal}, BitsLeft = {BitsLeft}",
+                            bunch.bHasPackageMapExports ? 1 : 0,
+                            bunch.bPartialFinal ? 1 : 0,
+                            bunch.GetBitsLeft());
+                        bunch.SetError();
+                        return false;
+                    }
+                    
+                    // Advance the sequence of the current partial bunch so we know what to expect next
+                    InPartialBunch.ChSequence = bunch.ChSequence;
+
+                    if (bunch.bPartialFinal)
+                    {
+                        Logger.Verbose("Completed Partial Bunch ({BytesLeft} left)", bunch.GetBytesLeft());
+
+                        if (bunch.bHasPackageMapExports)
+                        {
+                            // Shouldn't have these, they only go in initial partial export bunches
+                            Logger.Warning("Corrupt partial bunch. Final partial bunch has package map exports");
+                            bunch.SetError();
+                            return false;
+                        }
+
+                        handleBunch = InPartialBunch;
+
+                        InPartialBunch.bPartialFinal = true;
+                        InPartialBunch.bClose = bunch.bClose;
+                        InPartialBunch.bDormant = bunch.bDormant;
+                        InPartialBunch.CloseReason = bunch.CloseReason;
+                        InPartialBunch.bIsReplicationPaused = bunch.bIsReplicationPaused;
+                        InPartialBunch.bHasMustBeMappedGUIDs = bunch.bHasMustBeMappedGUIDs;
+                    }
+                    else
+                    {
+                        Logger.Verbose("Received Partial Bunch");
+                    }
+                }
+                else
+                {
+                    // Merge problem - delete InPartialBunch.
+                    // This is mainly so that in the unlikely chance that ChSequence wraps around, we wont merge two completely separate partial bunches.
+                    // We shouldn't hit this path on 100% reliable connections
+
+                    if (Connection.IsInternalAck())
+                    {
+                        throw new UnrealNetException("We shouldn't hit this path on 100% reliable connections");
+                    }
+
+                    bOutSkipAck = true; // Don't ack the packet, since we didn't process the bunch
+
+                    if (InPartialBunch != null && InPartialBunch.bReliable)
+                    {
+                        if (bunch.bReliable)
+                        {
+                            Logger.Warning("Reliable partial trying to destroy reliable partial 2");
+                            bunch.SetError();
+                            return false;
+                        }
+                        
+                        Logger.Warning("Unreliable partial trying to destroy reliable partial 2");
+                        return false;
+                    }
+
+                    if (InPartialBunch != null)
+                    {
+                        InPartialBunch = null;
+                    }
+                }
+            }
+            
+            // Fairly large number, and probably a bad idea to even have a bunch this size, but want to be safe for now and not throw out legitimate data
+            if (IsBunchTooLarge(Connection, InPartialBunch))
+            {
+                Logger.Error("Received a partial bunch exceeding max allowed size. BunchSize={Size}, MaximumSize={MaxSize}", InPartialBunch!.GetNumBytes(), NetMaxConstructedPartialBunchSizeBytes);
+                bunch.SetError();
+                return false;
+            }
+        }
+
+        if (handleBunch != null)
+        {
+            var bBothSidesCanOpen = Connection.Driver != null &&
+                                    Connection.Driver.ChannelDefinitionMap[ChName].ServerOpen &&
+                                    Connection.Driver.ChannelDefinitionMap[ChName].ClientOpen;
+                
+            if (handleBunch.bOpen)
+            {
+                // Voice channels can open from both side simultaneously, so ignore this logic until we resolve this
+                if (!bBothSidesCanOpen)
+                {
+                    // If we opened the channel, we shouldn't be receiving bOpen commands from the other side
+                    if (OpenedLocally)
+                    {
+                        throw new UnrealNetException("Received channel open command for channel that was already opened locally.");
+                    }
+
+                    if (OpenPacketId.First != UnrealConstants.IndexNone || OpenPacketId.Last != UnrealConstants.IndexNone)
+                    {
+                        Logger.Error("This should be the first and only assignment of the packet range (we should only receive one bOpen bunch)");
+                        bunch.SetError();
+                        return false;
+                    }
+                }
+
+                // Remember the range.
+                // In the case of a non partial, HandleBunch == Bunch
+                // In the case of a partial, HandleBunch should == InPartialBunch, and Bunch should be the last bunch.
+                OpenPacketId.First = handleBunch.PacketId;
+                OpenPacketId.Last = bunch.PacketId;
+                OpenAcked = true;
+
+                Logger.Verbose("ReceivedNextBunch: Channel now fully open. ChIndex: {ChIndex}, OpenPacketId.First: {First}, OpenPacketId.Last: {Last}", ChIndex, OpenPacketId.First, OpenPacketId.Last);
+            }
+
+            // Voice channels can open from both side simultaneously, so ignore this logic until we resolve this
+            if (!bBothSidesCanOpen)
+            {
+                // Don't process any packets until we've fully opened this channel 
+                // (unless we opened it locally, in which case it's safe to process packets)
+                if (!OpenedLocally && !OpenAcked)
+                {
+                    if (handleBunch.bReliable)
+                    {
+                        Logger.Error("ReceivedNextBunch: Reliable bunch before channel was fully open");
+                        bunch.SetError();
+                        return false;
+                    }
+
+                    if (Connection.IsInternalAck())
+                    {
+                        // Shouldn't be possible for 100% reliable connections
+                        Broken = true;
+                        return false;
+                    }
+
+                    // Don't ack this packet (since we won't process all of it)
+                    bOutSkipAck = true;
+                    
+                    Logger.Verbose("ReceivedNextBunch: Skipping bunch since channel isn't fully open. ChIndex: {ChIndex}", ChIndex);
+                    return false;
+                }
+
+                // At this point, we should have the open packet range
+                // This is because if we opened the channel locally, we set it immediately when we sent the first bOpen bunch
+                // If we opened it from a remote connection, then we shouldn't be processing any packets until it's fully opened (which is handled above)
+                if (OpenPacketId.First == -1)
+                {
+                    throw new UnrealNetException("Should have open packet range.");
+                }
+
+                if (OpenPacketId.Last == -1)
+                {
+                    throw new UnrealNetException("Should have open packet range.");
+                }
+            }
+            
+            // Receive it in sequence.
+            return ReceivedSequencedBunch(handleBunch);
+        }
+
+        return false;
+    }
+
+    private bool ReceivedSequencedBunch(FInBunch bunch)
+    {
+        // Handle a regular bunch.
+        if (!Closing)
+        {
+            ReceivedBunch(bunch);
+        }
+        
+        // We have fully received the bunch, so process it.
+        if (bunch.bClose)
+        {
+            Dormant = bunch.bDormant || (bunch.CloseReason == EChannelCloseReason.Dormancy);
+
+            if (InRec != null)
+            {
+                Logger.Warning("Close Anomaly {Seq} / {InRecSeq}", bunch.ChSequence, InRec.ChSequence);
+            }
+
+            if (ChIndex == 0)
+            {
+                Logger.Debug("UChannel::ReceivedSequencedBunch: Bunch.bClose == true. ChIndex == 0. Calling ConditionalCleanUp");   
+            }
+            
+            ConditionalCleanUp(false, bunch.CloseReason);
+            return true;
+        }
+
+        return false;
+    }
+
+    protected abstract void ReceivedBunch(FInBunch bunch);
+
+    public void ConditionalCleanUp(bool bForDestroy, EChannelCloseReason closeReason)
+    {
+        throw new NotImplementedException();
+    }
+
+    private static bool IsBunchTooLarge(UNetConnection connection, FInBunch? bunch)
+    {
+        return !connection.IsInternalAck() && bunch != null && bunch.GetNumBytes() > NetMaxConstructedPartialBunchSizeBytes;
+    }
+}

src/Prospect.Unreal/Net/Channels/UControlChannel.cs

@@ -0,0 +1,18 @@
+using Prospect.Unreal.Core.Names;
+using Prospect.Unreal.Net.Packets.Bunch;
+
+namespace Prospect.Unreal.Net.Channels;
+
+public class UControlChannel : UChannel
+{
+    public UControlChannel()
+    {
+        ChType = EChannelType.CHTYPE_Control;
+        ChName = UnrealNames.FNames[UnrealNameKey.Control];
+    }
+
+    protected override void ReceivedBunch(FInBunch bunch)
+    {
+        throw new NotImplementedException();
+    }
+}

src/Prospect.Unreal/Net/Channels/UVoiceChannel.cs

@@ -0,0 +1,18 @@
+using Prospect.Unreal.Core.Names;
+using Prospect.Unreal.Net.Packets.Bunch;
+
+namespace Prospect.Unreal.Net.Channels;
+
+public class UVoiceChannel : UChannel
+{
+    public UVoiceChannel()
+    {
+        ChType = EChannelType.CHTYPE_Voice;
+        ChName = UnrealNames.FNames[UnrealNameKey.Control];
+    }
+
+    protected override void ReceivedBunch(FInBunch bunch)
+    {
+        throw new NotImplementedException();
+    }
+}

src/Prospect.Unreal/Net/EAcceptConnection.cs

@@ -0,0 +1,11 @@
+namespace Prospect.Unreal.Net;
+
+public enum EAcceptConnection
+{
+    /** Reject the connection */
+    Reject,
+    /** Accept the connection */
+    Accept,
+    /** Ignore the connection, sending no reply, while server traveling */
+    Ignore
+}

src/Prospect.Unreal/Net/FChannelCloseInfo.cs

@@ -0,0 +1,15 @@
+using Prospect.Unreal.Net.Channels;
+
+namespace Prospect.Unreal.Net;
+
+public readonly struct FChannelCloseInfo
+{
+    public FChannelCloseInfo(uint id, EChannelCloseReason closeReason)
+    {
+        Id = id;
+        CloseReason = closeReason;
+    }
+
+    public uint Id { get; }
+    public EChannelCloseReason CloseReason { get; }
+}

src/Prospect.Unreal/Net/FChannelDefinition.cs

@@ -1,3 +1,5 @@
-namespace Prospect.Unreal.Net;
+using Prospect.Unreal.Core.Names;
 
-public record FChannelDefinition(string Name, Type Class, int StaticChannelIndex, bool TickOnCreate, bool ServerOpen, bool ClientOpen, bool InitialServer, bool InitialClient);
+namespace Prospect.Unreal.Net;
+
+public record FChannelDefinition(FName Name, Type Class, int StaticChannelIndex, bool TickOnCreate, bool ServerOpen, bool ClientOpen, bool InitialServer, bool InitialClient);

src/Prospect.Unreal/Net/FNetworkNotify.cs

@@ -0,0 +1,28 @@
+using Prospect.Unreal.Net.Channels;
+using Prospect.Unreal.Net.Packets.Bunch;
+
+namespace Prospect.Unreal.Net;
+
+public interface FNetworkNotify
+{
+    EAcceptConnection NotifyAcceptingConnection();
+    
+    /// <summary>
+    ///     Notification that a new connection has been created/established as a result of a
+    ///     remote request, previously approved by NotifyAcceptingConnection
+    /// </summary>
+    void NotifyAcceptedConnection(UNetConnection connection);
+    
+    /// <summary>
+    ///     Notification that a new channel is being created/opened as a result of a remote request (Actor creation, etc)
+    /// </summary>
+    bool NotifyAcceptingChannel(UChannel channel);
+
+    /// <summary>
+    ///     Handler for messages sent through a remote connection's control channel not required to handle the message,
+    ///     but if it reads any data from Bunch, it MUST read the ENTIRE data stream for that message
+    ///
+    ///     (i.e. use FNetControlMessage::Receive())
+    /// </summary>
+    void NotifyControlMessage(UNetConnection connection, byte messageType, FInBunch bunch);
+}

src/Prospect.Unreal/Net/FPacketIdRange.cs

@@ -0,0 +1,12 @@
+namespace Prospect.Unreal.Net;
+
+public class FPacketIdRange
+{
+    public int First = -1;
+    public int Last = -1;
+
+    public bool InRange(int packetId)
+    {
+        return First <= packetId && packetId <= Last;
+    }
+}

src/Prospect.Unreal/Net/Packets/Bunch/FInBunch.cs

@@ -6,14 +6,46 @@ namespace Prospect.Unreal.Net.Packets.Bunch
 {
     public class FInBunch : FNetBitReader
     {
+        public FInBunch(FInBunch inBunch, bool copyBuffer) : base(inBunch.PackageMap, null, 0)
+        {
+            PacketId = inBunch.PacketId;
+            Next = inBunch.Next;
+            Connection = inBunch.Connection;
+            ChIndex = inBunch.ChIndex;
+            ChType = inBunch.ChType;
+            ChName = inBunch.ChName;
+            ChSequence = inBunch.ChSequence;
+            bOpen = inBunch.bOpen;
+            bClose = inBunch.bClose;
+            bDormant = inBunch.bDormant;
+            bIsReplicationPaused = inBunch.bIsReplicationPaused;
+            bReliable = inBunch.bReliable;
+            bPartial = inBunch.bPartial;
+            bPartialInitial = inBunch.bPartialInitial;
+            bPartialFinal = inBunch.bPartialFinal;
+            bHasPackageMapExports = inBunch.bHasPackageMapExports;
+            bHasMustBeMappedGUIDs = inBunch.bHasMustBeMappedGUIDs;
+            bIgnoreRPCs = inBunch.bIgnoreRPCs;
+            CloseReason = inBunch.CloseReason;
+            
+            // Copy network version info
+            SetEngineNetVer(inBunch.EngineNetVer());
+            SetGameNetVer(inBunch.GameNetVer());
+
+            if (copyBuffer)
+            {
+                throw new NotImplementedException();
+            }
+        }
+        
         public FInBunch(UNetConnection inConnection, byte[]? src = null, int countBits = 0) : base(inConnection.PackageMap, src, countBits)
         {
             PacketId = 0;
             Next = null;
             Connection = inConnection;
             ChIndex = 0;
-            ChType = 0; // TODO: CHTYPE_None
+            ChType = EChannelType.CHTYPE_None;
-            ChName = UnrealNames.FNames[UnrealNameKey.None]; // TODO: NAME_None
+            ChName = UnrealNames.FNames[UnrealNameKey.None];
             ChSequence = 0;
             bOpen = false;
             bClose = false;
@@ -41,7 +73,7 @@ namespace Prospect.Unreal.Net.Packets.Bunch
 
         public int ChIndex { get; set; }
 
-        public int ChType { get; set; }
+        public EChannelType ChType { get; set; }
         
         public FName ChName { get; set; }
 

src/Prospect.Unreal/Net/Packets/Header/FNetPacketNotify.cs

@@ -71,7 +71,7 @@ public class FNetPacketNotify
         var inSeqDelta = GetSequenceDelta(notificationData);
         if (inSeqDelta > 0)
         {
-            Logger.Verbose("FNetPacketNotify::Update - Seq {Seq}, InSeq {InSeq}", notificationData.Seq.Value, _inSeq.Value);
+            Logger.Verbose("Update - Seq {Seq}, InSeq {InSeq}", notificationData.Seq.Value, _inSeq.Value);
 
             ProcessReceivedAcks(notificationData, func);
 
@@ -143,4 +143,34 @@ public class FNetPacketNotify
 
         return new SequenceNumber((ushort)(ackedSeq.Value - MaxSequenceHistoryLength));
     }
+
+    /// <summary>
+    ///     Mark Seq as received and update current InSeq, missing sequence numbers will be marked as lost
+    /// </summary>
+    public void AckSeq(SequenceNumber seq)
+    {
+        AckSeq(seq, true);
+    }
+
+    /// <summary>
+    ///     Explicitly mark Seq as not received and update current InSeq, additional missing sequence numbers will be marked as lost
+    /// </summary>
+    public void NakSeq(SequenceNumber seq)
+    {
+        AckSeq(seq, false);
+    }
+
+    private void AckSeq(SequenceNumber ackedSeq, bool isAck)
+    {
+        while (ackedSeq.Greater(_inAckSeq))
+        {
+            _inAckSeq.IncrementAndGet();
+
+            var bReportAcked = _inAckSeq.Equals(ackedSeq) ? isAck : false;
+            
+            Logger.Verbose("AckSeq - AckedSeq: {Seq}, IsAck {IsAck}", _inAckSeq.Value, bReportAcked);
+
+            _inSeqHistory.AddDeliveryStatus(bReportAcked);
+        }
+    }
 }

src/Prospect.Unreal/Net/Packets/Header/Sequence/SequenceHistory.cs

@@ -18,15 +18,6 @@ public readonly struct SequenceHistory
     {
         _storage = new uint[WordCount];
     }
-    
-    public void Read(FBitReader reader, uint numWords)
-    {
-        numWords = Math.Min(numWords, WordCount);
-        for (var i = 0; i < numWords; i++)
-        {
-            _storage[i] = reader.ReadUInt32();
-        }
-    }
 
     public void Reset()
     {
@@ -36,6 +27,20 @@ public readonly struct SequenceHistory
         }
     }
 
+    public void AddDeliveryStatus(bool delivered)
+    {
+        var carry = delivered ? 1u : 0u;
+        var valueMask = 1u << (int)(BitsPerWord - 1);
+
+        for (var i = 0; i < WordCount; i++)
+        {
+            var oldValue = carry;
+
+            carry = (_storage[i] & valueMask) >> (int)(BitsPerWord - 1);
+            _storage[i] = (_storage[i] << 1) | oldValue;
+        }
+    }
+
     public bool IsDelivered(int index)
     {
         var wordIndex = (int)(index / BitsPerWord);
@@ -43,4 +48,13 @@ public readonly struct SequenceHistory
 
         return (_storage[wordIndex] & wordMask) != 0;
     }
+    
+    public void Read(FBitReader reader, uint numWords)
+    {
+        numWords = Math.Min(numWords, WordCount);
+        for (var i = 0; i < numWords; i++)
+        {
+            _storage[i] = reader.ReadUInt32();
+        }
+    }
 }

src/Prospect.Unreal/Net/Player/APlayerController.cs

@@ -0,0 +1,6 @@
+namespace Prospect.Unreal.Net.Player;
+
+public class APlayerController
+{
+    
+}

src/Prospect.Unreal/Net/Player/UPlayer.cs

@@ -0,0 +1,6 @@
+namespace Prospect.Unreal.Net.Player;
+
+public class UPlayer
+{
+    public APlayerController? PlayerController { get; set; }
+}

src/Prospect.Unreal/Net/UChannel.cs

@@ -1,8 +0,0 @@
-using Prospect.Unreal.Core.Names;
-
-namespace Prospect.Unreal.Net;
-
-public class UChannel
-{
-    public FName ChName { get; }
-}

src/Prospect.Unreal/Net/UIpConnection.cs

@@ -55,7 +55,13 @@ public class UIpConnection : UNetConnection
 
     public override string LowLevelGetRemoteAddress(bool bAppendPort = false)
     {
-        throw new NotImplementedException();
+        if (RemoteAddr != null)
+        {
+            // TODO: Remove port
+            return RemoteAddr.ToString();
+        }
+
+        return string.Empty;
     }
 
     public override string LowLevelDescribe()

src/Prospect.Unreal/Net/UIpNetDriver.cs

@@ -22,8 +22,13 @@ public class UIpNetDriver : UNetDriver
     public UdpClient Socket { get; }
     public FReceiveThreadRunnable ReceiveThread { get; }
 
-    public override bool Init()
+    public override bool Init(FNetworkNotify notify)
     {
+        if (!base.Init(notify))
+        {
+            return false;
+        }
+        
         // Initialize connectionless packet handler.
         InitConnectionlessHandler();
         

src/Prospect.Unreal/Net/UNetConnection.cs

@@ -1,4 +1,5 @@
-using System.Net;
+using System.Diagnostics.CodeAnalysis;
+using System.Net;
 using System.Net.Sockets;
 using Prospect.Unreal.Core;
 using Prospect.Unreal.Core.Names;
@@ -7,12 +8,13 @@ using Prospect.Unreal.Net.Channels;
 using Prospect.Unreal.Net.Packets.Bunch;
 using Prospect.Unreal.Net.Packets.Header;
 using Prospect.Unreal.Net.Packets.Header.Sequence;
+using Prospect.Unreal.Net.Player;
 using Prospect.Unreal.Serialization;
 using Serilog;
 
 namespace Prospect.Unreal.Net;
 
-public abstract class UNetConnection
+public abstract class UNetConnection : UPlayer
 {
     private static readonly ILogger Logger = Log.ForContext<UNetConnection>();
     
@@ -30,6 +32,7 @@ public abstract class UNetConnection
     public const EEngineNetworkVersionHistory DefaultEngineNetworkProtocolVersion = EEngineNetworkVersionHistory.HISTORY_ENGINENETVERSION_LATEST;
     public const uint DefaultGameNetworkProtocolVersion = 0;
 
+    private HashSet<UChannel> _channelsToTick;
     private List<FBitReader>? _packetOrderCache;
     private int _packetOrderCacheStartIdx;
     private int _packetOrderCacheCount;
@@ -38,8 +41,17 @@ public abstract class UNetConnection
     private bool _bInternalAck;
     private bool _bReplay;
 
+    private double _statUpdateTime;
+    private double _lastReceiveTime;
+    private double _lastReceiveRealTime;
+    private double _lastGoodPacketRealtime;
+    private double _lastTime;
+    private double _lastSendTime;
+    private double _lastTickTime;
+
     public UNetConnection()
     {
+        _channelsToTick = new HashSet<UChannel>();
         _packetOrderCache = null;
         _packetOrderCacheStartIdx = 0;
         _packetOrderCacheCount = 0;
@@ -49,6 +61,7 @@ public abstract class UNetConnection
         
         Driver = null;
         PackageMap = null;
+        OpenChannels = new List<UChannel>();
         MaxPacket = 0;
         Url = new FUrl();
         RemoteAddr = new IPEndPoint(IPAddress.None, 0);
@@ -85,6 +98,8 @@ public abstract class UNetConnection
     /// </summary>
     public UPackageMapClient? PackageMap { get; private set; }
     
+    public List<UChannel> OpenChannels { get; private set; }
+    
     /// <summary>
     ///     Maximum packet size.
     /// </summary>
@@ -168,7 +183,17 @@ public abstract class UNetConnection
         Driver = inDriver;
         
         // TODO: ConnectionId
+        
+        var driverElapsedTime = Driver.GetElapsedTime();
 
+        _statUpdateTime = driverElapsedTime;
+        _lastReceiveTime = driverElapsedTime;
+        _lastReceiveRealTime = 0;
+        _lastGoodPacketRealtime = 0;
+        _lastTime = 0;
+        _lastSendTime = driverElapsedTime;
+        _lastTickTime = driverElapsedTime;
+        
         State = inState;
 
         Url.Protocol = inURL.Protocol;
@@ -263,7 +288,8 @@ public abstract class UNetConnection
         }
 
         var resetReaderMark = new FBitReaderMark(reader);
-
+        var channelsToClose = new List<FChannelCloseInfo>();
+        
         if (_bInternalAck)
         {
             ++InPacketId;
@@ -369,7 +395,7 @@ public abstract class UNetConnection
         }
 
         var bIgnoreRPCS = Driver!.ShouldIgnoreRPCs();
-        var bSickAcp = false;
+        var bSkipAck = false;
         
         // Track channels that were rejected while processing this packet - used to avoid sending multiple close-channel bunches,
         // which would cause a disconnect serverside
@@ -471,7 +497,7 @@ public abstract class UNetConnection
                 
                 if (bunch.EngineNetVer() < EEngineNetworkVersionHistory.HISTORY_CHANNEL_NAMES)
                 {
-                    bunch.ChType = (bunch.bReliable || bunch.bOpen) ? (int) reader.ReadInt(EChannelType.CHTYPE_MAX) : EChannelType.CHTYPE_None;
+                    bunch.ChType = ((bunch.bReliable || bunch.bOpen) ? (EChannelType) reader.ReadInt((int) EChannelType.CHTYPE_MAX) : EChannelType.CHTYPE_None);
 
                     switch (bunch.ChType)
                     {
@@ -533,10 +559,225 @@ public abstract class UNetConnection
                     // TODO: Close();
                     return;
                 }
+
+                var bunchDataBits = reader.ReadInt((uint)(MaxPacket * 8));
+                var headerPos = reader.GetPosBits();
+                if (reader.IsError())
+                {
+                    Logger.Error("Bunch header overflow");
+                    // TODO: Close();
+                    return;
+                }
+                
+                bunch.SetData(reader, bunchDataBits);
+
+                if (reader.IsError())
+                {
+                    Logger.Fatal("Bunch data overflowed ({IncomingStartPos} {HeaderPos}+{BunchDataBits}/{NumBits})", incomingStartPos, headerPos, bunchDataBits, reader.GetNumBits());
+                    // TOOD: Close();
+                    return;
+                }
+
+                if (bunch.bHasPackageMapExports)
+                {
+                    throw new NotImplementedException();
+                }
+
+                if (bunch.bReliable)
+                {
+                    Logger.Verbose("  Reliable Bunch, Channel {Ch} Sequence {Seq}: Size {A.0}+{B.0}", bunch.ChIndex, bunch.ChSequence, (headerPos - incomingStartPos)/8.0f, (reader.GetPosBits()-headerPos)/8.0f);
+                }
+                else
+                {
+                    Logger.Verbose("  Unreliable Bunch, Channel {Ch}: Size {A.0}+{B.0}", bunch.ChIndex, (headerPos - incomingStartPos)/8.0f, (reader.GetPosBits()-headerPos)/8.0f);
+                }
+
+                if (bunch.bOpen)
+                {
+                    Logger.Verbose("  bOpen Bunch, Channel {Ch} Sequence {Seq}: Size {A.0}+{B.0}", bunch.ChIndex, bunch.ChSequence, (headerPos - incomingStartPos)/8.0f, (reader.GetPosBits()-headerPos)/8.0f);
+                }
+
+                if (Channels[bunch.ChIndex] == null && (bunch.ChIndex != 0 || bunch.ChName != UnrealNames.FNames[UnrealNameKey.Control]))
+                {
+                    if (Channels[0] == null)
+                    {
+                        Logger.Fatal("  Received non-control bunch before control channel was created. ChIndex: {Ch}, ChName: {Name}", bunch.ChIndex, bunch.ChName);
+                        // TODO: Close();
+                        return;
+                    } 
+                    else if (PlayerController == null && Driver.ClientConnections.Contains(this))
+                    {
+                        Logger.Fatal("  Received non-control bunch before player controller was assigned. ChIndex: {Ch}, ChName: {Name}", bunch.ChIndex, bunch.ChName);
+                        // TODO: Close();
+                        return;
+                    }
+                }
+
+                // ignore control channel close if it hasn't been opened yet
+                if (bunch.ChIndex == 0 && Channels[0] == null && bunch.bClose && bunch.ChName == UnrealNames.FNames[UnrealNameKey.Control])
+                {
+                    Logger.Fatal("Received control channel close before open");
+                    // Close();
+                    return;
+                }
+
+                // We're on a 100% reliable connection and we are rolling back some data.
+                // In that case, we can generally ignore these bunches.
+                if (_bInternalAck /* && _bAllowExistingChannelIndex */)
+                {
+                    throw new NotImplementedException();
+                }
+                
+                // Ignore if reliable packet has already been processed.
+                if (bunch.bReliable && bunch.ChSequence <= InReliable[bunch.ChIndex])
+                {
+                    Logger.Warning("Received outdated bunch (Channel {Ch} Current Sequence {Seq})", bunch.ChIndex, InReliable[bunch.ChIndex]);
+                    continue;
+                }
+
+                // If opening the channel with an unreliable packet, check that it is "bNetTemporary", otherwise discard it
+                if (channel == null && !bunch.bReliable)
+                {
+                    // Unreliable bunches that open channels should be bOpen && (bClose || bPartial)
+                    // NetTemporary usually means one bunch that is unreliable (bOpen and bClose):	1(bOpen, bClose)
+                    // But if that bunch export NetGUIDs, it will get split into 2 bunches:			1(bOpen, bPartial) - 2(bClose).
+                    // (the initial actor bunch itself could also be split into multiple bunches. So bPartial is the right check here)
+
+                    var validUnreliableOpen = bunch.bOpen && (bunch.bClose || bunch.bPartial);
+                    if (!validUnreliableOpen)
+                    {
+                        if (_bInternalAck)
+                        {
+                            // Should be impossible with 100% reliable connections
+                            Logger.Error("Received unreliable bunch before open with reliable connection (Channel {Ch} Current Sequence {Seq})", bunch.ChIndex, InReliable[bunch.ChIndex]);
+                        }
+                        else
+                        {
+                            // Simply a log (not a warning, since this can happen under normal conditions, like from a re-join, etc)
+                            Logger.Information("Received unreliable bunch before open (Channel {Ch} Current Sequence {Seq})", bunch.ChIndex, InReliable[bunch.ChIndex]);
+                        }
+
+                        // Since we won't be processing this packet, don't ack it
+                        // We don't want the sender to think this bunch was processed when it really wasn't
+                        bSkipAck = true;
+                        continue;
+                    }
+                }
+
+                // Create channel if necessary.
+                if (channel == null)
+                {
+                    if (rejectedChans.Contains(bunch.ChIndex))
+                    {
+                        Logger.Warning("Ignoring Bunch for ChIndex {Ch}, as the channel was already rejected while processing this packet", bunch.ChIndex);
+                        continue;
+                    }
+                    
+                    // Validate channel type.
+                    if (!Driver.IsKnownChannelName(bunch.ChName))
+                    {
+                        // Unknown type.
+                        Logger.Fatal("Connection unknown channel type ({Name})", bunch.ChName);
+                        // TODO: Close()
+                        return;
+                    }
+
+                    // Ignore incoming data on channel types that the client are not allowed to create. This can occur if we have in-flight data when server is closing a channel
+                    if (Driver.IsServer() && (Driver.ChannelDefinitionMap[bunch.ChName].ClientOpen == false))
+                    {
+                        Logger.Warning("Ignoring Bunch Create received from client since only server is allowed to create this type of channel: Bunch  {Ch}: ChName {Name}, ChSequence: {Seq}", bunch.ChIndex, bunch.ChName, bunch.ChSequence);
+                        rejectedChans.Add(bunch.ChIndex);
+                        continue;
+                    }
+
+                    // peek for guid
+                    if (_bInternalAck /* && bIgnoreActorBunches */)
+                    {
+                        throw new NotImplementedException();
+                    }
+                    
+                    // Reliable (either open or later), so create new channel.
+                    Logger.Information("  Bunch Create {ChIndex}: ChName {ChName}, ChSequence: {ChSequence}, bReliable: {Reliable}, bPartial: {Partial}, bPartialInitial: {PartInit}, bPartialFinal: {PartFin}",
+                        bunch.ChIndex,
+                        bunch.ChName,
+                        bunch.ChSequence,
+                        bunch.bReliable,
+                        bunch.bPartial,
+                        bunch.bPartialInitial,
+                        bunch.bPartialFinal);
+
+                    channel = CreateChannelByName(bunch.ChName, EChannelCreateFlags.None, bunch.ChIndex);
+
+                    // Notify the server of the new channel.
+                    if (!Driver.Notify.NotifyAcceptingChannel(channel))
+                    {
+                        // Channel refused, so close it, flush it, and delete it.
+                        Logger.Verbose("NotifyAcceptingChannel Failed! Channel: {Channel}", channel);
+                        rejectedChans.Add(bunch.ChIndex);
+                        
+                        // TODO: FOutBunch
+                        continue;
+                    }
+                }
+
+                bunch.bIgnoreRPCs = bIgnoreRPCS;
+                
+                // Dispatch the raw, unsequenced bunch to the channel.
+                channel.ReceivedRawBunch(bunch, out var bLocalSkipAck);
+
+                if (bLocalSkipAck)
+                {
+                    bSkipAck = true;
+                }
+                
+                // Disconnect if we received a corrupted packet from the client (eg server crash attempt).
+                if (Driver.IsServer() && (bunch.IsCriticalError() || bunch.IsError()))
+                {
+                    Logger.Error("Received corrupted packet data from client {RemoteAddress}.  Disconnecting", LowLevelGetRemoteAddress());
+                    // TODO: Close()
+                    return;
+                }
             }
         }
 
-        throw new NotImplementedException();
+        // Close/clean-up channels pending close due to received acks.
+        foreach (var info in channelsToClose)
+        {
+            var channel = Channels[info.Id];
+            if (channel != null)
+            {
+                channel.ConditionalCleanUp(false, info.CloseReason);
+            }
+        }
+
+        // TODO: ValidateSendBuffer();
+
+        if (!bSkipAck)
+        {
+            _lastGoodPacketRealtime = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+        }
+
+        if (!_bInternalAck)
+        {
+            if (bSkipAck)
+            {
+                PacketNotify.NakSeq(new SequenceNumber((ushort)InPacketId));
+            }
+            else
+            {
+                PacketNotify.AckSeq(new SequenceNumber((ushort)InPacketId));
+                
+                // TODO: Increment things
+                // ++OutTotalAcks;
+                // ++Driver->OutTotalAcks;
+            }
+            
+            // We do want to let the other side know about the ack, so even if there are no other outgoing data when we tick the connection we will send an ackpacket.
+            // TimeSensitive = 1;
+            // ++HasDirtyAcks;
+            
+            // TODO: FlushNet if HasDirtyAcks
+        }
     }
 
     private bool ReadPacketInfo(FBitReader reader, bool bHasPacketInfoPayload)
@@ -641,10 +882,93 @@ public abstract class UNetConnection
         Handler.InitializeComponents();
     }
 
-    public void CreateChannelByName(string chName, EChannelCreateFlags createFlags, int channelIndex)
+    public UChannel CreateChannelByName(FName chName, EChannelCreateFlags createFlags, int chIndex)
     {
-        // TODO: Implement
+        if (!Driver!.IsKnownChannelName(chName))
-        Logger.Verbose("Creating channel {Name} with index {Index}", chName, channelIndex);
+        {
+            throw new UnrealNetException("Unknown channel name was specified.");
+        }
+
+        if (chIndex == UnrealConstants.IndexNone)
+        {
+            chIndex = GetFreeChannelIndex(chName);
+
+            if (chIndex == UnrealConstants.IndexNone)
+            {
+                Logger.Warning("No free channel could be found in the channel list (current limit is {Max} channels)", MaxChannelSize);
+                throw new UnrealNetException("Exhausted channels");
+            }
+        }
+        
+        // Make sure channel is valid.
+        if (chIndex >= Channels.Length)
+        {
+            throw new UnrealNetException("Channel index is too high.");
+        }
+
+        if (Channels[chIndex] != null)
+        {
+            throw new UnrealNetException("Trying to replace an existing channel.");
+        }
+        
+        // Create channel.
+        var channel = Driver.GetOrCreateChannelByName(chName);
+        if (channel == null)
+        {
+            throw new UnrealNetException("Failed to create channel.");
+        }
+
+        channel.Init(this, chIndex, createFlags);
+        
+        Channels[chIndex] = channel;
+        OpenChannels.Add(channel);
+
+        if (Driver.ChannelDefinitionMap[chName].TickOnCreate)
+        {
+            StartTickingChannel(channel);
+        }
+        
+        Logger.Verbose("Created channel {Ch} of type {Name}", chIndex, chName);
+
+        return channel;
+    }
+
+    private int GetFreeChannelIndex(FName chName)
+    {
+        int chIndex;
+        var firstChannel = 1;
+
+        var staticChannelIndex = Driver!.ChannelDefinitionMap[chName].StaticChannelIndex;
+        if (staticChannelIndex != -1)
+        {
+            firstChannel = staticChannelIndex;
+        }
+                
+        // Search the channel array for an available location
+        for (chIndex = firstChannel; chIndex < Channels.Length; chIndex++)
+        {
+            if (Channels[chIndex] == null)
+            {
+                break;
+            }
+        }
+
+        if (chIndex == Channels.Length)
+        {
+            chIndex = UnrealConstants.IndexNone;
+        }
+
+        return chIndex;
+    }
+
+    private void StartTickingChannel(UChannel channel)
+    {
+        _channelsToTick.Add(channel);
+    }
+
+    private void StopTickingChannel(UChannel channel)
+    {
+        _channelsToTick.Remove(channel);
     }
 
     private protected void SetClientLoginState(EClientLoginState newState)
@@ -673,6 +997,11 @@ public abstract class UNetConnection
         ExpectedClientLoginMsgType = newType;
     }
 
+    public bool IsInternalAck()
+    {
+        return _bInternalAck;
+    }
+
     private static int BestSignedDifference(int value, int reference, int max)
     {
         return ((value - reference + max / 2) & (max - 1)) - max / 2;

src/Prospect.Unreal/Net/UNetDriver.cs

@@ -1,5 +1,7 @@
 using System.Collections.Concurrent;
 using System.Net;
+using Prospect.Unreal.Core.Names;
+using Prospect.Unreal.Exceptions;
 using Prospect.Unreal.Net.Channels;
 using Prospect.Unreal.Runtime;
 
@@ -13,14 +15,20 @@ public abstract class UNetDriver : IAsyncDisposable
     {
         GuidCache = new FNetGUIDCache(this);
         // TODO: Load from Engine ini
+        ChannelDefinitionMap = new Dictionary<FName, FChannelDefinition>();
         ChannelDefinitions = new List<FChannelDefinition>
         {
-            new FChannelDefinition("Control", typeof(string), 0, true, false, true, false, true),
+            new FChannelDefinition(UnrealNames.FNames[UnrealNameKey.Control], typeof(string), 0, true, false, true, false, true),
-            new FChannelDefinition("Voice", typeof(string), 1, true, true, true, true, true),
+            new FChannelDefinition(UnrealNames.FNames[UnrealNameKey.Voice], typeof(string), 1, true, true, true, true, true),
-            new FChannelDefinition("Actor", typeof(string), -1, false, true, false, false, false)
+            new FChannelDefinition(UnrealNames.FNames[UnrealNameKey.Actor], typeof(string), -1, false, true, false, false, false)
         };
         ClientConnections = new List<UNetConnection>();
         MappedClientConnections = new ConcurrentDictionary<IPEndPoint, UNetConnection>();
+        
+        foreach (var channel in ChannelDefinitions)
+        {
+            ChannelDefinitionMap[channel.Name] = channel;
+        }
     }
     
     /// <summary>
@@ -28,12 +36,19 @@ public abstract class UNetDriver : IAsyncDisposable
     /// </summary>
     public UWorld? World { get; private set; }
     
+    public FNetworkNotify Notify { get; private set; }
+    
     public FNetGUIDCache GuidCache { get; }
     
     /// <summary>
     ///     Used to specify available channel types and their associated UClass
     /// </summary>
     public List<FChannelDefinition> ChannelDefinitions { get; } 
+    
+    /// <summary>
+    ///     Used for faster lookup of channel definitions by name.
+    /// </summary>
+    public Dictionary<FName, FChannelDefinition> ChannelDefinitionMap { get; }
 
     /// <summary>
     ///     Array of connections to clients (this net driver is a host) - unsorted, and ordering changes depending on actor replication
@@ -66,9 +81,10 @@ public abstract class UNetDriver : IAsyncDisposable
         ConnectionlessHandler.InitializeComponents();
     }
 
-    public virtual bool Init()
+    public virtual bool Init(FNetworkNotify notify)
     {
-        throw new NotImplementedException();
+        Notify = notify;
+        return true;
     }
     
     public virtual void TickDispatch(float deltaTime)
@@ -103,6 +119,11 @@ public abstract class UNetDriver : IAsyncDisposable
         return true;
     }
 
+    public bool IsKnownChannelName(FName name)
+    {
+        return ChannelDefinitionMap.ContainsKey(name);
+    }
+
     public virtual bool ShouldIgnoreRPCs()
     {
         return false;
@@ -145,6 +166,19 @@ public abstract class UNetDriver : IAsyncDisposable
         }
     }
 
+    public UChannel GetOrCreateChannelByName(FName chName)
+    {
+        // TODO: Pool actor channels (?)
+
+        return (UnrealNameKey)chName.Number switch
+        {
+            UnrealNameKey.Actor => new UActorChannel(),
+            UnrealNameKey.Control => new UControlChannel(),
+            UnrealNameKey.Voice => new UVoiceChannel(),
+            _ => throw new UnrealNetException($"Attempted to create unknown channel {chName}")
+        };
+    }
+
     public virtual ValueTask DisposeAsync()
     {
         return ValueTask.CompletedTask;

src/Prospect.Unreal/Runtime/UWorld.cs

@@ -1,10 +1,12 @@
 using Prospect.Unreal.Core;
 using Prospect.Unreal.Net;
+using Prospect.Unreal.Net.Channels;
+using Prospect.Unreal.Net.Packets.Bunch;
 using Serilog;
 
 namespace Prospect.Unreal.Runtime;
 
-public abstract class UWorld : IAsyncDisposable
+public abstract class UWorld : FNetworkNotify, IAsyncDisposable
 {
     private static readonly ILogger Logger = Log.ForContext<UWorld>();
 
@@ -36,7 +38,7 @@ public abstract class UWorld : IAsyncDisposable
         NetDriver = new UIpNetDriver(Url.Host, Url.Port);
         NetDriver.SetWorld(this);
 
-        if (!NetDriver.Init())
+        if (!NetDriver.Init(this))
         {
             Logger.Error("Failed to listen");
             NetDriver = null;
@@ -46,6 +48,44 @@ public abstract class UWorld : IAsyncDisposable
         return true;
     }
 
+    public EAcceptConnection NotifyAcceptingConnection()
+    {
+        return EAcceptConnection.Accept;
+    }
+
+    public void NotifyAcceptedConnection(UNetConnection connection)
+    {
+        
+    }
+
+    public bool NotifyAcceptingChannel(UChannel channel)
+    {
+        var driver = channel.Connection.Driver!;
+        if (!driver.IsServer())
+        {
+            throw new NotSupportedException("Client code");
+        }
+        else
+        {
+            // We are the server.
+            if (driver.ChannelDefinitionMap[channel.ChName].ClientOpen)
+            {
+                // The client has opened initial channel.
+                Logger.Verbose("NotifyAcceptingChannel {ChName} {ChIndex} server {FullName}: Accepted", channel.ChName, channel.ChIndex, typeof(UWorld).FullName);
+                return true;
+            }
+
+            // Client can't open any other kinds of channels.
+            Logger.Verbose("NotifyAcceptingChannel {ChName} {ChIndex} server {FullName}: Refused", channel.ChName, channel.ChIndex, typeof(UWorld).FullName);
+            return false;
+        }
+    }
+
+    public void NotifyControlMessage(UNetConnection connection, byte messageType, FInBunch bunch)
+    {
+        
+    }
+
     public async ValueTask DisposeAsync()
     {
         if (NetDriver != null)

src/Prospect.Unreal/Serialization/FBitReaderMark.cs

@@ -1,6 +1,6 @@
 namespace Prospect.Unreal.Serialization;
 
-public class FBitReaderMark
+public struct FBitReaderMark
 {
     private long _pos;