protected override async Task <IEnumerable <string>?> GetHostNameListImplAsync(IPAddress ip, Ref <DnsAdditionalResults>?additional = null, CancellationToken cancel = default)
{
DnsAdditionalResults additionalData = new DnsAdditionalResults(true, false);
try
{
var res = await Client.QueryReverseAsync(ip, cancel);
if (res.Header.ResponseCode == DnsHeaderResponseCode.NotExistentDomain)
{
additionalData = new DnsAdditionalResults(false, true);
}
if (res.HasError)
{
additionalData = new DnsAdditionalResults(true, false);
return(null);
}
return(res.Answers?.PtrRecords().Select(x => x.PtrDomainName.ToString()).ToArray() ?? null);
}
finally
{
additional?.Set(additionalData);
}
}
protected override async Task <IEnumerable <IPAddress>?> GetIpAddressListImplAsync(string hostname, DnsResolverQueryType queryType, Ref <DnsAdditionalResults>?additional = null, CancellationToken cancel = default)
{
DnsAdditionalResults additionalData = new DnsAdditionalResults(true, false);
QueryType qt;
switch (queryType)
{
case DnsResolverQueryType.A:
qt = QueryType.A;
break;
case DnsResolverQueryType.AAAA:
qt = QueryType.AAAA;
break;
default:
throw new ArgumentOutOfRangeException(nameof(queryType));
}
try
{
var res = await Client.QueryAsync(hostname, qt, queryClass : QueryClass.IN, cancel);
if (res.Header.ResponseCode == DnsHeaderResponseCode.NotExistentDomain)
{
additionalData = new DnsAdditionalResults(false, true);
}
if (res.HasError)
{
additionalData = new DnsAdditionalResults(true, false);
return(null);
}
if (qt == QueryType.A)
{
return(res.Answers?.ARecords().Where(x => x.Address.AddressFamily == AddressFamily.InterNetwork).Select(x => x.Address).ToArray() ?? null);
}
else
{
return(res.Answers?.AaaaRecords().Where(x => x.Address.AddressFamily == AddressFamily.InterNetworkV6).Select(x => x.Address).ToArray() ?? null);
}
}
finally
{
additional?.Set(additionalData);
}
}
public ReverseLookupCacheItem(List <string>?value, DnsAdditionalResults additionalResults)
{
Value = value;
AdditionalResults = additionalResults;
}
public ForwardLookupCacheItem(List <IPAddress>?value, DnsAdditionalResults additionalResults)
{
Value = value;
AdditionalResults = additionalResults;
}
