private static void StartHelper(NetworkAddressChangedEventHandler caller, bool captureContext, StartIPOptions startIPOptions)
{
lock (s_callerArray)
{
// Setup changedEvent and native overlapped struct.
if (s_ipv4Socket == null)
{
int blocking;
// Sockets will be initialized by the call to OSSupportsIP*.
if (Socket.OSSupportsIPv4)
{
blocking = -1;
s_ipv4Socket = SafeCloseSocketAndEvent.CreateWSASocketWithEvent(AddressFamily.InterNetwork, SocketType.Dgram, (ProtocolType)0, true, false);
Interop.Winsock.ioctlsocket(s_ipv4Socket, Interop.Winsock.IoctlSocketConstants.FIONBIO, ref blocking);
s_ipv4WaitHandle = s_ipv4Socket.GetEventHandle();
}
if (Socket.OSSupportsIPv6)
{
blocking = -1;
s_ipv6Socket = SafeCloseSocketAndEvent.CreateWSASocketWithEvent(AddressFamily.InterNetworkV6, SocketType.Dgram, (ProtocolType)0, true, false);
Interop.Winsock.ioctlsocket(s_ipv6Socket, Interop.Winsock.IoctlSocketConstants.FIONBIO, ref blocking);
s_ipv6WaitHandle = s_ipv6Socket.GetEventHandle();
}
}
if ((caller != null) && (!s_callerArray.ContainsKey(caller)))
{
s_callerArray.Add(caller, captureContext ? ExecutionContext.Capture() : null);
}
if (s_isListening || s_callerArray.Count == 0)
{
return;
}
if (!s_isPending)
{
int length;
SocketError errorCode;
if (Socket.OSSupportsIPv4 && (startIPOptions & StartIPOptions.StartIPv4) != 0)
{
s_registeredWait = ThreadPool.RegisterWaitForSingleObject(
s_ipv4WaitHandle,
new WaitOrTimerCallback(AddressChangedCallback),
StartIPOptions.StartIPv4,
-1,
true);
errorCode = Interop.Winsock.WSAIoctl_Blocking(
s_ipv4Socket.DangerousGetHandle(),
(int)IOControlCode.AddressListChange,
null, 0, null, 0,
out length,
SafeNativeOverlapped.Zero, IntPtr.Zero);
if (errorCode != SocketError.Success)
{
NetworkInformationException exception = new NetworkInformationException();
if (exception.ErrorCode != (uint)SocketError.WouldBlock)
{
throw exception;
}
}
SafeWaitHandle s_ipv4SocketGetEventHandleSafeWaitHandle =
s_ipv4Socket.GetEventHandle().GetSafeWaitHandle();
errorCode = Interop.Winsock.WSAEventSelect(
s_ipv4Socket,
s_ipv4SocketGetEventHandleSafeWaitHandle,
Interop.Winsock.AsyncEventBits.FdAddressListChange);
if (errorCode != SocketError.Success)
{
throw new NetworkInformationException();
}
}
if (Socket.OSSupportsIPv6 && (startIPOptions & StartIPOptions.StartIPv6) != 0)
{
s_registeredWait = ThreadPool.RegisterWaitForSingleObject(
s_ipv6WaitHandle,
new WaitOrTimerCallback(AddressChangedCallback),
StartIPOptions.StartIPv6,
-1,
true);
errorCode = Interop.Winsock.WSAIoctl_Blocking(
s_ipv6Socket.DangerousGetHandle(),
(int)IOControlCode.AddressListChange,
null, 0, null, 0,
out length,
SafeNativeOverlapped.Zero, IntPtr.Zero);
if (errorCode != SocketError.Success)
{
NetworkInformationException exception = new NetworkInformationException();
if (exception.ErrorCode != (uint)SocketError.WouldBlock)
{
throw exception;
}
}
SafeWaitHandle s_ipv6SocketGetEventHandleSafeWaitHandle =
s_ipv6Socket.GetEventHandle().GetSafeWaitHandle();
errorCode = Interop.Winsock.WSAEventSelect(
s_ipv6Socket,
s_ipv6SocketGetEventHandleSafeWaitHandle,
Interop.Winsock.AsyncEventBits.FdAddressListChange);
if (errorCode != SocketError.Success)
{
throw new NetworkInformationException();
}
}
}
s_isListening = true;
s_isPending = true;
}
}
