public static unsafe void GetAddrInfoAsync(DnsResolveAsyncResult asyncResult)
{
GetAddrInfoExContext *context = GetAddrInfoExContext.AllocateContext();
try
{
var state = new GetAddrInfoExState(asyncResult);
context->QueryStateHandle = state.CreateHandle();
}
catch
{
GetAddrInfoExContext.FreeContext(context);
throw;
}
AddressInfoEx hints = new AddressInfoEx();
hints.ai_flags = AddressInfoHints.AI_CANONNAME;
hints.ai_family = AddressFamily.Unspecified; // Gets all address families
SocketError errorCode =
(SocketError)Interop.Winsock.GetAddrInfoExW(asyncResult.HostName, null, 0 /* NS_ALL*/, IntPtr.Zero, ref hints, out context->Result, IntPtr.Zero, ref context->Overlapped, s_getAddrInfoExCallback, out context->CancelHandle);
if (errorCode != SocketError.IOPending)
{
ProcessResult(errorCode, context);
}
}
private static unsafe void ProcessResult(SocketError errorCode, GetAddrInfoExContext *context)
{
try
{
GetAddrInfoExState state = GetAddrInfoExState.FromHandleAndFree(context->QueryStateHandle);
if (errorCode != SocketError.Success)
{
state.CompleteAsyncResult(new SocketException((int)errorCode));
return;
}
AddressInfoEx *result = context->Result;
string canonicalName = null;
List <IPAddress> addresses = new List <IPAddress>();
while (result != null)
{
if (canonicalName == null && result->ai_canonname != IntPtr.Zero)
{
canonicalName = Marshal.PtrToStringUni(result->ai_canonname);
}
var socketAddress = new ReadOnlySpan <byte>(result->ai_addr, result->ai_addrlen);
if (result->ai_family == AddressFamily.InterNetwork)
{
if (socketAddress.Length == SocketAddressPal.IPv4AddressSize)
{
addresses.Add(CreateIPv4Address(socketAddress));
}
}
else if (SocketProtocolSupportPal.OSSupportsIPv6 && result->ai_family == AddressFamily.InterNetworkV6)
{
if (socketAddress.Length == SocketAddressPal.IPv6AddressSize)
{
addresses.Add(CreateIPv6Address(socketAddress));
}
}
result = result->ai_next;
}
if (canonicalName == null)
{
canonicalName = state.HostName;
}
state.CompleteAsyncResult(new IPHostEntry
{
HostName = canonicalName,
Aliases = Array.Empty <string>(),
AddressList = addresses.ToArray()
});
}
finally
{
GetAddrInfoExContext.FreeContext(context);
}
}