public static List <IPAddress> GetHostAddresses(Resolver r, string domain, string NSServer)
{
try
{
Resolver currentResolver = r.Clone();
currentResolver.DnsServer = NSServer;
List <IPAddress> lst = new List <IPAddress>();
Response response = currentResolver.Query(domain, QType.A, QClass.IN);
foreach (RecordA rA in response.RecordsA)
{
lst.Add(rA.Address);
}
response = currentResolver.Query(domain, QType.AAAA, QClass.IN);
foreach (RecordAAAA rAAAA in response.RecordsAAAA)
{
lst.Add(rAAAA.Address);
}
return(lst);
}
catch
{
return(new List <IPAddress>());
}
}
/// <summary>
/// Devuelve todos los DNS que funcionen para un determinado dominio
/// </summary>
/// <param name="r"></param>
/// <param name="domain"></param>
/// <param name="NSServer"></param>
/// <param name="previosNSrecords"></param>
/// <returns></returns>
public static ICollection <string> GetNSServer(Resolver r, string domain, string NSServer, ICollection <string> previosNSrecords = null)
{
try
{
Resolver currentResolver = r.Clone();
HashSet <string> ips = new HashSet <string>(StringComparer.OrdinalIgnoreCase);
if (previosNSrecords == null)
{
previosNSrecords = new HashSet <string>(StringComparer.OrdinalIgnoreCase);
}
previosNSrecords.Add(NSServer);
currentResolver.DnsServer = NSServer;
Response response = currentResolver.Query(domain, QType.NS);
if (response.RecordsNS.Length > 0)
{
HashSet <string> nameservers = new HashSet <string>();
//No es autoritativa, volver a preguntar
if (!response.header.AA)
{
nameservers.UnionWith(response.RecordsNS.Where(p => !previosNSrecords.Contains(p.NSDNAME)).Select(p => p.NSDNAME));
foreach (string rNS in nameservers)
{
ips.UnionWith(GetNSServer(currentResolver, domain, rNS, previosNSrecords));
}
}
else
{
foreach (RecordNS rNS in response.RecordsNS)
{
nameservers.Add(RemoveLastPoint(rNS.NSDNAME));
}
}
//Resuelve los dominios de los DNS
foreach (string ns in nameservers)
{
foreach (IPAddress ip in DNSUtil.GetHostAddresses(ns))
{
if (!ips.Contains(ip.ToString()))
{
if (TestDNS(ip.ToString()))
{
ips.Add(ip.ToString());
}
}
}
}
return(ips);
}
//Hay servidores autoritativos para esta petición
else if (response.Authorities.Count > 0)
{
try
{
//Se devuelve el servidor DNS autoritativo
if (response.Authorities[0].RECORD is RecordSOA recordSOA)
{
string dns = RemoveLastPoint(recordSOA.MNAME);
if (TestDNS(dns))
{
return(new List <string>()
{
dns
});
}
}
if (response.Authorities[0].RECORD is RecordNS recordNS)
{
string dns = RemoveLastPoint(recordNS.NSDNAME);
if (TestDNS(dns))
{
return(new List <string>()
{
dns
});
}
}
}
catch { }
}
}
catch { }
return(new List <string>());
}