/// <summary>
/// Resolves this request into a response using the provided DNS information. The given
/// request strategy is used to retrieve the response.
/// </summary>
/// <exception cref="DnsResponseException">Throw if a malformed response is received from the server</exception>
/// <exception cref="IOException">Thrown if a IO error occurs</exception>
/// <exception cref="SocketException">Thrown if the reading or writing to the socket fails</exception>
/// <exception cref="OperationCanceledException">Thrown if reading or writing to the socket timeouts</exception>
/// <returns>The response received from server</returns>
public async Task <IDnsResponse> Resolve()
{
try
{
IDnsResponse response = await resolver.Resolve(this);
if (response.Id != this.Id)
{
throw new DnsResponseException(response, "Mismatching request/response IDs");
}
if (response.ResponseCode != DnsResponseCode.NoError)
{
throw new DnsResponseException(response);
}
return(response);
}
catch (ArgumentException e)
{
throw new DnsResponseException("Invalid response", e);
}
catch (IndexOutOfRangeException e)
{
throw new DnsResponseException("Invalid response", e);
}
}
public async Task <IDnsResponse> Resolve(IDnsRequest request)
{
using (UdpClient udp = new UdpClient())
{
await udp
.SendAsync(request.ToArray(), request.Size, dns)
.WithCancellationTimeout(timeout);
UdpReceiveResult result = await udp.ReceiveAsync().WithCancellationTimeout(timeout);
if (!result.RemoteEndPoint.Equals(dns))
{
throw new IOException("Remote endpoint mismatch");
}
byte[] buffer = result.Buffer;
DefaultDnsResponse response = DefaultDnsResponse.FromArray(buffer);
if (response.Truncated)
{
return(await fallback.Resolve(request));
}
return(new ClientDnsResponse(request, response, buffer));
}
}