private DnsPackage ResolveFromServer(DnsPackage request)
{
UdpClient udp = new UdpClient();
IPEndPoint dns = new IPEndPoint(IPAddress.Parse(SERVER_ADDRESS), DEFAULT_PORT);
udp.Client.ReceiveTimeout = UDP_TIMEOUT;
try
{
udp.Connect(dns);
var bytes = request.GetBytes();
udp.Send(bytes, bytes.Length);
byte[] buffer = udp.Receive(ref dns);
DnsPackage response = DnsPackage.FromArray(buffer); //null;
return(response);
}
catch
{
throw;
return(ResolveFromServer(request));
}
finally
{
udp.Close();
}
}
private void AcceptClients(UdpClient udp, IPEndPoint endPoint)
{
while (true)
{
byte[] clientMessage;
try
{
clientMessage = udp.Receive(ref endPoint);
Console.WriteLine("CONNECTED");
}
catch (SocketException)
{
continue;
}
var taskEndPoint = endPoint;
Task.Factory.StartNew(() =>
{
Console.WriteLine("I'M IN TASK");
var request = DnsPackage.FromArray(clientMessage);
DnsPackage response = ResolveRequest(request);
response.Header.ANCOUNT = (short)(response.Answers.Count);
response.Header.ARCOUNT = 0;
response.Header.NSCOUNT = 0;
var bytes = response.GetBytes();
udp.Send(bytes, bytes.Length, taskEndPoint);
});
}
}
public string Resolve(string domain, string requestType)
{
var endPoint = new IPEndPoint(IPAddress.Parse(ip), DEFAULT_PORT);
var udp = new UdpClient();
udp.Connect(endPoint);
udp.Client.SendTimeout = UDP_TIMEOUT;
var sender = new IPEndPoint(IPAddress.Any, DEFAULT_PORT);
var packageType = requestType == "NS" ? Package.Type.NS : Package.Type.A;
DnsPackage request = new DnsPackage(new PackageHeader(), new PackageQuestion(domain, packageType), new List <PackageAnswer>());
var bytes = request.GetBytes();
udp.Send(bytes, bytes.Length);
var serverMessage = udp.Receive(ref endPoint);
var answer = DnsPackage.FromArray(serverMessage);
return(answer.Answers.Select(x => x.GetAnswer(serverMessage)).Aggregate("", (current, ans) => current + ans + "\r\n"));
}
private DnsPackage ResolveRequest(DnsPackage request)
{
lock (storage)
{
if (storage.ContainKey(request.Question))
{
return(new DnsPackage(request.Header, request.Question, storage.Get(request.Question)));
}
}
try
{
var answer = ResolveFromServer(request);
lock (storage)
{
storage.Add(request.Question, answer.Answers);
foreach (var addit in answer.Additionals)
{
storage.Add(addit.Question, new List <PackageAnswer> {
addit
});
}
foreach (var a in answer.Auth)
{
storage.Add(a.Question, new List <PackageAnswer> {
a
});
}
}
return(answer);
}
catch
{
throw;
return(request);
}
}
