private void ProcessUdpRequestAsync(object parameter)
{
object[] parameters = parameter as object[];
EndPoint remoteEP = parameters[0] as EndPoint;
DnsDatagram request = parameters[1] as DnsDatagram;
try
{
DnsDatagram response = ProcessQuery(request, remoteEP);
//send response
if (response != null)
{
FixMemoryStream sendBufferStream = new FixMemoryStream(512);
try
{
response.WriteTo(sendBufferStream);
}
catch (EndOfStreamException)
{
DnsHeader header = response.Header;
response = new DnsDatagram(new DnsHeader(header.Identifier, true, header.OPCODE, header.AuthoritativeAnswer, true, header.RecursionDesired, header.RecursionAvailable, header.AuthenticData, header.CheckingDisabled, header.RCODE, header.QDCOUNT, 0, 0, 0), response.Question, null, null, null);
sendBufferStream.Position = 0;
response.WriteTo(sendBufferStream);
}
//send dns datagram
_udpListener.SendTo(sendBufferStream.Buffer, 0, (int)sendBufferStream.Position, SocketFlags.None, remoteEP);
LogManager queryLog = _queryLog;
if (queryLog != null)
{
queryLog.Write((IPEndPoint)remoteEP, false, request, response);
}
}
}
catch (Exception ex)
{
LogManager queryLog = _queryLog;
if (queryLog != null)
{
queryLog.Write((IPEndPoint)remoteEP, false, request, null);
}
LogManager log = _log;
if (log != null)
{
log.Write((IPEndPoint)remoteEP, ex);
}
}
}
private void ReadResponsePacketsAsync(object parameter)
{
Socket udpClient = parameter as Socket;
EndPoint remoteEP;
FixMemoryStream recvStream = new FixMemoryStream(BUFFER_MAX_SIZE);
byte[] bufferRecv = recvStream.Buffer;
int bytesRecv;
if (udpClient.AddressFamily == AddressFamily.InterNetwork)
{
remoteEP = new IPEndPoint(IPAddress.Any, 0);
}
else
{
remoteEP = new IPEndPoint(IPAddress.IPv6Any, 0);
}
try
{
while (true)
{
bytesRecv = udpClient.ReceiveFrom(bufferRecv, ref remoteEP);
if (bytesRecv > 0)
{
recvStream.SetLength(bytesRecv);
recvStream.Position = 0;
IPEndPoint remoteNodeEP = remoteEP as IPEndPoint;
if (NetUtilities.IsIPv4MappedIPv6Address(remoteNodeEP.Address))
{
remoteNodeEP = new IPEndPoint(NetUtilities.ConvertFromIPv4MappedIPv6Address(remoteNodeEP.Address), remoteNodeEP.Port);
}
try
{
DhtRpcPacket response = new DhtRpcPacket(recvStream, remoteNodeEP.Address);
ProcessPacket(response);
}
catch
{ }
}
}
}
catch (Exception ex)
{
Debug.Write("DhtClient.ReadResponsePacketsAsync", ex);
}
}
private void RecvDataAsync(object parameter)
{
Socket udpListener = parameter as Socket;
EndPoint remoteEP = null;
FixMemoryStream dataRecv = new FixMemoryStream(BUFFER_MAX_SIZE);
int bytesRecv;
if (udpListener.AddressFamily == AddressFamily.InterNetwork)
{
remoteEP = new IPEndPoint(IPAddress.Any, 0);
}
else
{
remoteEP = new IPEndPoint(IPAddress.IPv6Any, 0);
}
try
{
while (true)
{
//receive message from remote
bytesRecv = udpListener.ReceiveFrom(dataRecv.Buffer, ref remoteEP);
if (bytesRecv > 0)
{
IPAddress peerIP = (remoteEP as IPEndPoint).Address;
if (NetUtilities.IsIPv4MappedIPv6Address(peerIP))
{
peerIP = NetUtilities.ConvertFromIPv4MappedIPv6Address(peerIP);
}
dataRecv.Position = 0;
dataRecv.SetLength(bytesRecv);
try
{
ReceivedPacket(new DiscoveryPacket(dataRecv), peerIP);
}
catch (Exception ex)
{
Debug.Write("LocalPeerDiscovery.Listner.RecvDataAsync", ex);
}
}
}
}
catch (Exception ex)
{
Debug.Write("LocalPeerDiscovery.Listner.RecvDataAsync", ex);
}
}
private void ReadQueryPacketsAsync(object parameter)
{
Socket udpListener = parameter as Socket;
EndPoint remoteEP;
FixMemoryStream recvBufferStream = new FixMemoryStream(BUFFER_MAX_SIZE);
FixMemoryStream sendBufferStream = new FixMemoryStream(BUFFER_MAX_SIZE);
int bytesRecv;
if (udpListener.AddressFamily == AddressFamily.InterNetwork)
{
remoteEP = new IPEndPoint(IPAddress.Any, 0);
}
else
{
remoteEP = new IPEndPoint(IPAddress.IPv6Any, 0);
}
try
{
while (true)
{
bytesRecv = udpListener.ReceiveFrom(recvBufferStream.Buffer, ref remoteEP);
if (bytesRecv > 0)
{
recvBufferStream.Position = 0;
recvBufferStream.SetLength(bytesRecv);
IPEndPoint remoteNodeEP = remoteEP as IPEndPoint;
if (NetUtilities.IsIPv4MappedIPv6Address(remoteNodeEP.Address))
{
remoteNodeEP = new IPEndPoint(NetUtilities.ConvertFromIPv4MappedIPv6Address(remoteNodeEP.Address), remoteNodeEP.Port);
}
try
{
DhtRpcPacket request = new DhtRpcPacket(recvBufferStream, remoteNodeEP.Address);
DhtRpcPacket response = ProcessPacket(request);
//send response
if (response != null)
{
sendBufferStream.Position = 0;
response.WriteTo(sendBufferStream);
udpListener.SendTo(sendBufferStream.Buffer, 0, (int)sendBufferStream.Position, SocketFlags.None, remoteEP);
}
//if contact doesnt exists then add contact else update last seen time
KBucket closestBucket = _routingTable.FindClosestBucket(request.SourceNode.NodeID);
NodeContact contact = closestBucket.FindContactInCurrentBucket(request.SourceNode.NodeID);
if (contact == null)
{
//check if the closest bucket can accomodate another contact
if (!closestBucket.IsCurrentBucketFull(true))
{
ThreadPool.QueueUserWorkItem(AddContactAfterPingAsync, request.SourceNode);
}
}
else
{
contact.UpdateLastSeenTime();
}
}
catch
{ }
}
}
}
catch (Exception ex)
{
Debug.Write("DhtClient.ReadQueryPacketsAsync", ex);
}
}
private void ProcessTcpRequestAsync(object parameter)
{
Socket tcpSocket = parameter as Socket;
DnsDatagram request = null;
try
{
FixMemoryStream recvBufferStream = new FixMemoryStream(128);
MemoryStream sendBufferStream = new MemoryStream(512);
int bytesRecv;
while (true)
{
//read dns datagram length
bytesRecv = tcpSocket.Receive(recvBufferStream.Buffer, 0, 2, SocketFlags.None);
if (bytesRecv < 1)
{
return; //do nothing
}
Array.Reverse(recvBufferStream.Buffer, 0, 2);
short length = BitConverter.ToInt16(recvBufferStream.Buffer, 0);
//read dns datagram
int offset = 0;
while (offset < length)
{
bytesRecv = tcpSocket.Receive(recvBufferStream.Buffer, offset, length, SocketFlags.None);
if (bytesRecv < 1)
{
throw new SocketException();
}
offset += bytesRecv;
}
bytesRecv = length;
if (bytesRecv > 0)
{
recvBufferStream.Position = 0;
recvBufferStream.SetLength(bytesRecv);
request = new DnsDatagram(recvBufferStream);
DnsDatagram response = ProcessQuery(request, tcpSocket.RemoteEndPoint);
//send response
if (response != null)
{
//write dns datagram
sendBufferStream.Position = 0;
response.WriteTo(sendBufferStream);
//prepare final buffer
byte[] lengthBytes = BitConverter.GetBytes(Convert.ToInt16(sendBufferStream.Position));
byte[] buffer = new byte[sendBufferStream.Position + 2];
//copy datagram length
buffer[0] = lengthBytes[1];
buffer[1] = lengthBytes[0];
//copy datagram
sendBufferStream.Position = 0;
sendBufferStream.Read(buffer, 2, buffer.Length - 2);
//send dns datagram
tcpSocket.Send(buffer, 0, buffer.Length, SocketFlags.None);
LogManager queryLog = _queryLog;
if (queryLog != null)
{
queryLog.Write((IPEndPoint)tcpSocket.RemoteEndPoint, true, request, response);
}
}
}
}
}
catch (Exception ex)
{
LogManager queryLog = _queryLog;
if ((queryLog != null) && (request != null))
{
queryLog.Write((IPEndPoint)tcpSocket.RemoteEndPoint, true, request, null);
}
LogManager log = _log;
if (log != null)
{
log.Write((IPEndPoint)tcpSocket.RemoteEndPoint, ex);
}
}
finally
{
if (tcpSocket != null)
{
tcpSocket.Dispose();
}
}
}
private void ReadUdpQueryPacketsAsync(object parameter)
{
#region this code ignores ICMP port unreachable responses which creates SocketException in ReceiveFrom()
if (Environment.OSVersion.Platform == PlatformID.Win32NT)
{
const uint IOC_IN = 0x80000000;
const uint IOC_VENDOR = 0x18000000;
const uint SIO_UDP_CONNRESET = IOC_IN | IOC_VENDOR | 12;
_udpListener.IOControl((IOControlCode)SIO_UDP_CONNRESET, new byte[] { Convert.ToByte(false) }, null);
}
#endregion
EndPoint remoteEP = null;
FixMemoryStream recvBufferStream = new FixMemoryStream(128);
int bytesRecv;
try
{
while (true)
{
if (_udpListener.AddressFamily == AddressFamily.InterNetwork)
{
remoteEP = new IPEndPoint(IPAddress.Any, 0);
}
else
{
remoteEP = new IPEndPoint(IPAddress.IPv6Any, 0);
}
try
{
bytesRecv = _udpListener.ReceiveFrom(recvBufferStream.Buffer, ref remoteEP);
}
catch (SocketException ex)
{
switch (ex.SocketErrorCode)
{
case SocketError.ConnectionReset:
case SocketError.HostUnreachable:
bytesRecv = 0;
break;
default:
throw;
}
}
if (bytesRecv > 0)
{
recvBufferStream.Position = 0;
recvBufferStream.SetLength(bytesRecv);
try
{
ThreadPool.QueueUserWorkItem(ProcessUdpRequestAsync, new object[] { remoteEP, new DnsDatagram(recvBufferStream) });
}
catch
{ }
}
}
}
catch (Exception ex)
{
LogManager log = _log;
if (log != null)
{
log.Write((IPEndPoint)remoteEP, ex);
}
if (_state == ServiceState.Running)
{
throw;
}
}
}
