//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);
}
void InitSockets(bool updateListenPort)
{
bool ipV4;
bool ipV6;
UdpUtility.CheckSocketSupport(out ipV4, out ipV6);
Fx.Assert(this.listenSockets == null, "listen sockets should only be initialized once");
this.listenSockets = new List <UdpSocket>();
int port = (this.listenUri.IsDefaultPort ? 0 : this.listenUri.Port);
if (this.listenUri.HostNameType == UriHostNameType.IPv6 ||
this.listenUri.HostNameType == UriHostNameType.IPv4)
{
UdpUtility.ThrowOnUnsupportedHostNameType(this.listenUri);
IPAddress address = IPAddress.Parse(this.listenUri.DnsSafeHost);
if (UdpUtility.IsMulticastAddress(address))
{
this.isMulticast = true;
NetworkInterface[] adapters = UdpUtility.GetMulticastInterfaces(udpTransportBindingElement.MulticastInterfaceId);
//if listening on a specific adapter, don't disable multicast loopback on that adapter.
bool allowMulticastLoopback = !string.IsNullOrEmpty(this.udpTransportBindingElement.MulticastInterfaceId);
for (int i = 0; i < adapters.Length; i++)
{
if (adapters[i].OperationalStatus == OperationalStatus.Up)
{
IPInterfaceProperties properties = adapters[i].GetIPProperties();
bool isLoopbackAdapter = adapters[i].NetworkInterfaceType == NetworkInterfaceType.Loopback;
if (isLoopbackAdapter)
{
int interfaceIndex;
if (UdpUtility.TryGetLoopbackInterfaceIndex(adapters[i], address.AddressFamily == AddressFamily.InterNetwork, out interfaceIndex))
{
listenSockets.Add(UdpUtility.CreateListenSocket(address, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize, this.udpTransportBindingElement.TimeToLive,
interfaceIndex, allowMulticastLoopback, isLoopbackAdapter));
}
}
else if (this.listenUri.HostNameType == UriHostNameType.IPv6)
{
if (adapters[i].Supports(NetworkInterfaceComponent.IPv6))
{
IPv6InterfaceProperties v6Properties = properties.GetIPv6Properties();
if (v6Properties != null)
{
listenSockets.Add(UdpUtility.CreateListenSocket(address, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize,
this.udpTransportBindingElement.TimeToLive, v6Properties.Index, allowMulticastLoopback, isLoopbackAdapter));
}
}
}
else
{
if (adapters[i].Supports(NetworkInterfaceComponent.IPv4))
{
IPv4InterfaceProperties v4Properties = properties.GetIPv4Properties();
if (v4Properties != null)
{
listenSockets.Add(UdpUtility.CreateListenSocket(address, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize,
this.udpTransportBindingElement.TimeToLive, v4Properties.Index, allowMulticastLoopback, isLoopbackAdapter));
}
}
}
}
}
if (listenSockets.Count == 0)
{
throw FxTrace.Exception.AsError(new ArgumentException(SR.UdpFailedToFindMulticastAdapter(this.listenUri)));
}
}
else
{
//unicast - only sends on the default adapter...
this.listenSockets.Add(UdpUtility.CreateUnicastListenSocket(address, ref port,
this.udpTransportBindingElement.SocketReceiveBufferSize, this.udpTransportBindingElement.TimeToLive));
}
}
else
{
IPAddress v4Address = IPAddress.Any;
IPAddress v6Address = IPAddress.IPv6Any;
if (ipV4 && ipV6)
{
if (port == 0)
{
//port 0 is only allowed when ListenUriMode == ListenUriMode.Unique
UdpSocket ipv4Socket, ipv6Socket;
port = UdpUtility.CreateListenSocketsOnUniquePort(v4Address, v6Address, this.udpTransportBindingElement.SocketReceiveBufferSize, this.udpTransportBindingElement.TimeToLive, out ipv4Socket, out ipv6Socket);
this.listenSockets.Add(ipv4Socket);
this.listenSockets.Add(ipv6Socket);
}
else
{
this.listenSockets.Add(UdpUtility.CreateUnicastListenSocket(v4Address, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize, this.udpTransportBindingElement.TimeToLive));
this.listenSockets.Add(UdpUtility.CreateUnicastListenSocket(v6Address, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize, this.udpTransportBindingElement.TimeToLive));
}
}
else if (ipV4)
{
this.listenSockets.Add(UdpUtility.CreateUnicastListenSocket(v4Address, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize, this.udpTransportBindingElement.TimeToLive));
}
else if (ipV6)
{
this.listenSockets.Add(UdpUtility.CreateUnicastListenSocket(v6Address, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize, this.udpTransportBindingElement.TimeToLive));
}
}
if (updateListenPort && port != this.listenUri.Port)
{
UriBuilder uriBuilder = new UriBuilder(this.listenUri);
uriBuilder.Port = port;
this.listenUri = uriBuilder.Uri;
}
// Open all the sockets to keep ref counts consistent
foreach (UdpSocket udpSocket in this.ListenSockets)
{
udpSocket.Open();
}
}
//will only return > 1 socket when both of the following are true:
// 1) multicast
// 2) sending on all interfaces
UdpSocket[] GetSockets(Uri via, out IPEndPoint remoteEndPoint, out bool isMulticast)
{
UdpSocket[] results = null;
remoteEndPoint = null;
IPAddress[] remoteAddressList;
isMulticast = false;
UdpUtility.ThrowIfNoSocketSupport();
if (via.HostNameType == UriHostNameType.IPv6 || via.HostNameType == UriHostNameType.IPv4)
{
UdpUtility.ThrowOnUnsupportedHostNameType(via);
IPAddress address = IPAddress.Parse(via.DnsSafeHost);
isMulticast = UdpUtility.IsMulticastAddress(address);
remoteAddressList = new IPAddress[] { address };
}
else
{
remoteAddressList = DnsCache.Resolve(via).AddressList;
}
if (remoteAddressList.Length < 1)
{
// System.Net.Dns shouldn't ever allow this to happen, but...
Fx.Assert("DnsCache returned a HostEntry with zero length address list");
throw FxTrace.Exception.AsError(new EndpointNotFoundException(SR.DnsResolveFailed(via.DnsSafeHost)));
}
remoteEndPoint = new IPEndPoint(remoteAddressList[0], via.Port);
IPAddress localAddress;
if (via.IsLoopback)
{
localAddress = (remoteEndPoint.AddressFamily == AddressFamily.InterNetwork ? IPAddress.Loopback : IPAddress.IPv6Loopback);
}
else
{
localAddress = (remoteEndPoint.AddressFamily == AddressFamily.InterNetwork ? IPAddress.Any : IPAddress.IPv6Any);
}
int port = 0;
if (isMulticast)
{
List <UdpSocket> socketList = new List <UdpSocket>();
NetworkInterface[] adapters = UdpUtility.GetMulticastInterfaces(this.udpTransportBindingElement.MulticastInterfaceId);
//if listening on a specific adapter, don't disable multicast loopback on that adapter.
bool allowMulticastLoopback = !string.IsNullOrEmpty(this.udpTransportBindingElement.MulticastInterfaceId);
for (int i = 0; i < adapters.Length; i++)
{
if (adapters[i].OperationalStatus == OperationalStatus.Up)
{
IPInterfaceProperties properties = adapters[i].GetIPProperties();
bool isLoopbackAdapter = adapters[i].NetworkInterfaceType == NetworkInterfaceType.Loopback;
if (isLoopbackAdapter)
{
int interfaceIndex;
if (UdpUtility.TryGetLoopbackInterfaceIndex(adapters[i], localAddress.AddressFamily == AddressFamily.InterNetwork, out interfaceIndex))
{
socketList.Add(UdpUtility.CreateListenSocket(localAddress, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize, this.udpTransportBindingElement.TimeToLive,
interfaceIndex, allowMulticastLoopback, isLoopbackAdapter));
}
}
else if (localAddress.AddressFamily == AddressFamily.InterNetworkV6)
{
if (adapters[i].Supports(NetworkInterfaceComponent.IPv6))
{
IPv6InterfaceProperties v6Properties = properties.GetIPv6Properties();
if (v6Properties != null)
{
socketList.Add(UdpUtility.CreateListenSocket(localAddress, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize,
this.udpTransportBindingElement.TimeToLive, v6Properties.Index, allowMulticastLoopback, isLoopbackAdapter));
}
}
}
else
{
if (adapters[i].Supports(NetworkInterfaceComponent.IPv4))
{
IPv4InterfaceProperties v4Properties = properties.GetIPv4Properties();
if (v4Properties != null)
{
socketList.Add(UdpUtility.CreateListenSocket(localAddress, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize,
this.udpTransportBindingElement.TimeToLive, v4Properties.Index, allowMulticastLoopback, isLoopbackAdapter));
}
}
}
}
//CreateListenSocket sets the port, but since we aren't listening
//on multicast, each socket can't share the same port.
port = 0;
}
if (socketList.Count == 0)
{
throw FxTrace.Exception.AsError(new ArgumentException(SR.UdpFailedToFindMulticastAdapter(via)));
}
results = socketList.ToArray();
}
else
{
UdpSocket socket = UdpUtility.CreateUnicastListenSocket(localAddress, ref port, this.udpTransportBindingElement.SocketReceiveBufferSize,
this.udpTransportBindingElement.TimeToLive);
results = new UdpSocket[] { socket };
}
Fx.Assert(results != null, "GetSockets(...) return results should never be null. An exception should have been thrown but wasn't.");
return(results);
}