/// <summary>
/// Build and Send Query, Return Response
/// </summary>
public string TransactQuery()
{
try
{
// Generate the Request
var hostnameParts = _hostname.Split(".");
var request = new byte[41 + _hostname.Length + hostnameParts.Length];
request[0] = 33;
request[1] = 33;
request[2] = 1;
request[3] = 32;
request[5] = 1;
request[11] = 1;
var bitIdx = 12;
for (int partIdx = 0; partIdx < hostnameParts.Length; partIdx++)
{
request[bitIdx] = BitConverter.GetBytes(hostnameParts[partIdx].Length)[0];
bitIdx++;
foreach (var chr in hostnameParts[partIdx])
{
request[bitIdx] = BitConverter.GetBytes(chr)[0];
bitIdx++;
}
}
request[bitIdx] = 0;
bitIdx++;
request[bitIdx] = 0;
bitIdx++;
switch (_type)
{
case QueryType.a:
request[bitIdx] = 1;
break;
case QueryType.aaaa:
request[bitIdx] = 28;
break;
case QueryType.cname:
request[bitIdx] = 5;
break;
}
bitIdx++;
request[bitIdx] = 0;
bitIdx++;
request[bitIdx] = 1;
bitIdx += 3;
request[bitIdx] = 41;
bitIdx++;
request[bitIdx] = 16;
bitIdx += 7;
request[bitIdx] = 12;
bitIdx += 2;
request[bitIdx] = 10;
bitIdx += 2;
request[bitIdx] = 8;
bitIdx++;
request[bitIdx] = 78;
bitIdx++;
request[bitIdx] = 31;
bitIdx++;
request[bitIdx] = 252;
bitIdx++;
request[bitIdx] = 130;
bitIdx++;
request[bitIdx] = 235;
bitIdx++;
request[bitIdx] = 126;
bitIdx++;
request[bitIdx] = 94;
bitIdx++;
request[bitIdx] = 41;
// Initialize the client by binding the socket
var client = new UdpClient(_dnsserver.AddressFamily.Equals(AddressFamily.InterNetwork) ? AddressFamily.InterNetwork : AddressFamily.InterNetworkV6);
var ep = new IPEndPoint(_dnsserver, 53);
// Send the Query and Retrieve the Result
var requestMade = DateTime.Now;
var timer = new Stopwatch();
timer.Start();
client.Send(request, request.Length, ep);
var response = client.Receive(ref ep);
timer.Stop();
// Parse the Response
DnsResponse res = OutputData(response);
// Format the Request/Response
var responseString =
"->>HEADER<<- " + res + "\nQUESTION SECTION:\n" + res.QuestionsToString() + "\nANSWER SECTION:\n" + res.AnswersToString() + "\n";
responseString += "Query time: " + timer.ElapsedMilliseconds + " msec\nSERVER: " + _dnsserver + "#53(" + _dnsserver + ")\n";
responseString += "WHEN: " + String.Format("{0:ddd MMM dd HH:mm:ss} EDT {1:yyyy}", requestMade, requestMade) + "\nMSG SIZE rcvd: " + response.Length;
return(responseString);
}
catch (Exception)
{
// Connection Error Occured so return that instead of null valued strings
return("Error: Unable To Connect To DNS Server");
}
}
