//internal class SockInterfacePair
//{
// internal UdpSocket sock;
// internal IPAddress extInterface;
// public bool Initialized;
// internal SockInterfacePair(UdpSocket sock, IPAddress extIntf)
// {
// this.sock = sock;
// this.extInterface = extIntf;
// Initialized = false;
// }
//}
// Apparently binding to the same ports on UDPSender and UDPListener causes problems in unicast.
// Sharing the socket though, allows us to tunnel through firewalls as data is sent and received
// on the same endpoint.
// This region of code enables sharing sockets between the two classes.
//internal static SockInterfacePair GetSharedSocket(IPEndPoint endPoint)
//{
// lock (socks)
// {
// object sockObj = socks[endPoint];
// if (sockObj != null)
// {
// SockInterfacePair sip = (SockInterfacePair)sockObj;
// ++sip.sock.refCount;
// return sip;
// }
// else
// {
// // Create the socket
// UdpSocket sock = new UdpSocket(endPoint.AddressFamily);
// // Get the External Interface, save it for future use
// IPAddress externalInterface = Utility.GetLocalRoutingInterface(endPoint.Address);
// if (externalInterface == null)
// {
// // Pri3: Do something more helpful here
// throw new Exception(Strings.UnableToFindLocalRoutingInterface);
// }
// if (Utility.IsMulticast(endPoint.Address))
// {
// // Allow multiple binds to this socket, as it will still function properly
// // (this is only the case if it is a multicast socket. Unicast sockets fail to
// // receive all data on all sockets)
// sock.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, -1);
// // We don't join the multicast group here, because we may not want to listen
// // to our own data (halfing our throughput). jasonv - 10/28/2004
// }
// // Add the socket to the hashtable
// SockInterfacePair sip = new SockInterfacePair(sock, externalInterface);
// socks.Add(endPoint, sip);
// // Increase the socket's reference count
// ++sock.refCount;
// return sip;
// }
// }
//}
//internal static void ReleaseSharedSocket(IPEndPoint endPoint, UdpSocket sock)
//{
// object sockObj = socks[endPoint];
// if (sockObj == null)
// throw new InvalidOperationException(Strings.SockDoesNotExistAsASharedSocket);
// lock (socks)
// {
// if (--sock.refCount <= 0)
// {
// // Leave the multicast group
// if (Utility.IsMulticast(endPoint.Address))
// {
// try
// {
// if (endPoint.AddressFamily == AddressFamily.InterNetworkV6)
// {
// IPv6MulticastOption mo = new IPv6MulticastOption(endPoint.Address);
// sock.SetSocketOption(SocketOptionLevel.IPv6, SocketOptionName.DropMembership, mo);
// }
// else
// {
// MulticastOption mo = new MulticastOption(endPoint.Address);
// sock.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.DropMembership, mo);
// }
// }
// catch { } // The user of the socket *may* not have joined the multicast group (?)
// }
// // Remove ourselves from the shared pool
// socks.Remove(endPoint);
// // Close the socket
// try
// {
// sock.Close();
// }
// catch (ObjectDisposedException) { }
// }
// }
//}
internal static void ReleaseSocket(IPEndPoint endPoint, UdpSocket sock)
{
// Leave the multicast group
if (Utility.IsMulticast(endPoint.Address))
{
try
{
if (endPoint.AddressFamily == AddressFamily.InterNetworkV6)
{
IPv6MulticastOption mo = new IPv6MulticastOption(endPoint.Address);
sock.SetSocketOption(SocketOptionLevel.IPv6, SocketOptionName.DropMembership, mo);
}
else
{
MulticastOption mo = new MulticastOption(endPoint.Address);
sock.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.DropMembership, mo);
}
}
catch { } // The user of the socket *may* not have joined the multicast group (?)
}
// Close the socket
try
{
sock.Close();
}
catch (ObjectDisposedException) { }
}
//returns the port number used...
public static int CreateListenSocketsOnUniquePort(IPAddress ipv4Address, IPAddress ipv6Address, int receiveBufferSize, int timeToLive, out UdpSocket ipv4Socket, out UdpSocket ipv6Socket)
{
// We need both IPv4 and IPv6 on the same port. We can't atomicly bind for IPv4 and IPv6,
// so we try 10 times, which even with a 50% failure rate will statistically succeed 99.9% of the time.
//
// We look in the range of 49152-65534 for Vista default behavior parity.
// http://www.iana.org/assignments/port-numbers
//
// We also grab the 10 random numbers in a row to reduce collisions between multiple people somehow
// colliding on the same seed.
const int retries = 10;
const int lowWatermark = 49152;
const int highWatermark = 65535;
ipv4Socket = null;
ipv6Socket = null;
int[] portNumbers = new int[retries];
Random randomNumberGenerator = new Random(AppDomain.CurrentDomain.GetHashCode() | Environment.TickCount);
for (int i = 0; i < retries; i++)
{
portNumbers[i] = randomNumberGenerator.Next(lowWatermark, highWatermark);
}
int port = -1;
for (int i = 0; i < retries; i++)
{
port = portNumbers[i];
try
{
ipv4Socket = UdpUtility.CreateUnicastListenSocket(ipv4Address, ref port, receiveBufferSize, timeToLive);
ipv6Socket = UdpUtility.CreateUnicastListenSocket(ipv6Address, ref port, receiveBufferSize, timeToLive);
break;
}
catch (AddressAlreadyInUseException)
{
if (ipv4Socket != null)
{
ipv4Socket.Close();
ipv4Socket = null;
}
ipv6Socket = null;
}
catch (AddressAccessDeniedException)
{
if (ipv4Socket != null)
{
ipv4Socket.Close();
ipv4Socket = null;
}
ipv6Socket = null;
}
}
if (ipv4Socket == null)
{
throw FxTrace.Exception.AsError(new AddressAlreadyInUseException(SR.UniquePortNotAvailable));
}
Fx.Assert(ipv4Socket != null, "An exception should have been thrown if the ipv4Socket socket is null");
Fx.Assert(ipv6Socket != null, "An exception should have been thrown if the ipv6Socket socket is null");
Fx.Assert(port > 0, "The port number should have been greater than 0. Actual value was " + port);
return port;
}
