/// <summary>
/// Check whether or not there are MX or Address records associated with the given name.
/// </summary>
/// <returns></returns>
public bool CanMailExchange()
{
Results.ResolutionResult lastResult = null;
using (Iterators.ResolutionIterator iterator = GetIterator(QTYPE.ANY))
{
while (iterator.MoveNext())
{
lastResult = iterator.Current;
}
}
if (object.ReferenceEquals(null, lastResult))
{
throw new ResolverException("Resolution failed.");
}
switch (lastResult.Response.Header.RCODE)
{
case RCODE.NoError:
// check for Address or MX records
return(lastResult.Response.AnswerRecords.Where(
rr => typeof(Address).IsAssignableFrom(rr.GetType()) ||
typeof(MX).IsAssignableFrom(rr.GetType())).Any());
case RCODE.NameError: // Non-existent domain
return(false);
default: // failure
throw new ResolverException(String.Format(
"Unexpected RCODE {0} ({1}) from {2}.",
lastResult.Response.Header.RCODE.ToString(),
lastResult.Response.Header.RCODEValue,
lastResult.Authorities.Selected));
}
}
//public Iterators.RequestIterator GetIterator(DnsClient.DNS.QTYPE question)
//{
// return new Iterators.RequestIterator(this, question);
//}
public NameServerCollection GetNameServers(out bool isAuthoritative)
{
Results.ResolutionResult lastResult = null, lastNonEmptyResult = null;
using (Iterators.ResolutionIterator iterator = GetIterator(QTYPE.NS))
{
while (iterator.MoveNext())
{
lastResult = iterator.Current;
if (!lastResult.Authorities.IsEmpty)
{
lastNonEmptyResult = lastResult;
}
}
}
if (object.ReferenceEquals(null, lastResult) ||
object.ReferenceEquals(null, lastNonEmptyResult))
{
throw new ResolverException("Resolution failed.");
}
switch (lastResult.Response.Header.RCODE)
{
case RCODE.NoError:
isAuthoritative = lastResult.Response.AnswerRecords.Where(rr => null != rr as NS).Any();
return(lastNonEmptyResult.Authorities);
case RCODE.NameError: // Non-existent domain
isAuthoritative = true;
return(null);
default: // failure
throw new ResolverException(String.Format(
"Unexpected RCODE {0} ({1}) from {2}.",
lastResult.Response.Header.RCODE.ToString(),
lastResult.Response.Header.RCODEValue,
lastResult.Authorities.Selected));
}
}