void remoteReceive(IAsyncResult ar)
{
NatEntryValue natEntry = ar.AsyncState as NatEntryValue;
EndPoint recipientEndPoint = new IPEndPoint(0, 0);
int size = natEntry.RemoteSocket.EndReceiveFrom(ar, ref recipientEndPoint);
if (size > 0)
{
Packet packet = new Packet
{
FromEndPoint = remoteEndPoint,
PacketData = natEntry.Buffer,
ToEndPoint = natEntry.LocalEndPoint as IPEndPoint,
PacketSize = size,
IsIncoming = true
};
if (PacketFilter != null)
{
PacketFilter(packet);
}
udpListener.SendTo(packet.PacketData, packet.PacketSize, SocketFlags.None, natEntry.LocalEndPoint);
}
if ((DateTime.UtcNow - natEntry.TimeStamp).TotalMilliseconds < NatLifeTime)
{
natEntry.RemoteSocket.BeginReceiveFrom(natEntry.Buffer, 0, natEntry.Buffer.Length, SocketFlags.None, ref recipientEndPoint, new AsyncCallback(remoteReceive), ar.AsyncState);
}
}
void listenerReceive(IAsyncResult ar)
{
EndPoint recipientEndPoint = new IPEndPoint(0, 0);
int size = udpListener.EndReceiveFrom(ar, ref recipientEndPoint);
byte[] buffer = ar.AsyncState as byte[];
if (size > 0)
{
NatEntryValue natEntry = null;
lock (natTable)
{
natTable.TryGetValue(recipientEndPoint, out natEntry);
}
if (natEntry == null)
{
natEntry = new NatEntryValue
{
RemoteSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp),
TimeStamp = DateTime.UtcNow,
Buffer = new byte[buffer.Length],
LocalEndPoint = recipientEndPoint
};
natEntry.RemoteSocket.Connect(remoteEndPoint);
EndPoint nullEndPoint = new IPEndPoint(0, 0);
natEntry.RemoteSocket.BeginReceiveFrom(natEntry.Buffer, 0, natEntry.Buffer.Length, SocketFlags.None, ref nullEndPoint, new AsyncCallback(remoteReceive), natEntry);
lock (natTable)
{
natTable.Add(recipientEndPoint, natEntry);
}
}
natEntry.TimeStamp = DateTime.UtcNow;
Packet packet = new Packet
{
FromEndPoint = recipientEndPoint as IPEndPoint,
PacketData = buffer,
ToEndPoint = remoteEndPoint,
PacketSize = size,
IsIncoming = false
};
if (PacketFilter != null)
{
PacketFilter(packet);
}
natEntry.RemoteSocket.SendTo(packet.PacketData, packet.PacketSize, SocketFlags.None, remoteEndPoint);
}
recipientEndPoint = new IPEndPoint(0, 0);
udpListener.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref recipientEndPoint, new AsyncCallback(listenerReceive), ar.AsyncState);
}
