private AuthZone GetOrAddSubDomainZone(string domain)
{
return(_root.GetOrAdd(domain, delegate(string key)
{
_ = _root.FindZone(domain, out _, out AuthZone authZone, out _);
if (authZone == null)
{
throw new DnsServerException("Zone was not found for domain: " + domain);
}
if (authZone is PrimaryZone)
{
return new PrimarySubDomainZone(authZone as PrimaryZone, domain);
}
else if (authZone is SecondaryZone)
{
return new SecondarySubDomainZone(domain);
}
else if (authZone is ForwarderZone)
{
return new ForwarderSubDomainZone(domain);
}
throw new DnsServerException("Zone cannot have sub domains.");
}));
}
private List <DnsResourceRecord> GetAdditionalRecords(IReadOnlyCollection <DnsResourceRecord> nsRecords, bool serveStale)
{
List <DnsResourceRecord> additionalRecords = new List <DnsResourceRecord>();
foreach (DnsResourceRecord nsRecord in nsRecords)
{
if (nsRecord.Type != DnsResourceRecordType.NS)
{
continue;
}
CacheZone cacheZone = _root.FindZone((nsRecord.RDATA as DnsNSRecord).NameServer, out _, out _, out _);
if (cacheZone != null)
{
{
IReadOnlyList <DnsResourceRecord> records = cacheZone.QueryRecords(DnsResourceRecordType.A, serveStale);
if ((records.Count > 0) && (records[0].RDATA is DnsARecord))
{
additionalRecords.AddRange(records);
}
}
{
IReadOnlyList <DnsResourceRecord> records = cacheZone.QueryRecords(DnsResourceRecordType.AAAA, serveStale);
if ((records.Count > 0) && (records[0].RDATA is DnsAAAARecord))
{
additionalRecords.AddRange(records);
}
}
}
}
return(additionalRecords);
}
public DnsDatagram QueryClosestDelegation(DnsDatagram request)
{
_ = _root.FindZone(request.Question[0].Name, out CacheZone delegation, out _, out _);
if (delegation is not null)
{
//return closest name servers in delegation
IReadOnlyList <DnsResourceRecord> closestAuthority = delegation.QueryRecords(DnsResourceRecordType.NS, false, true);
if ((closestAuthority.Count > 0) && (closestAuthority[0].Type == DnsResourceRecordType.NS) && (closestAuthority[0].Name.Length > 0)) //dont trust root name servers from cache!
{
IReadOnlyList <DnsResourceRecord> additional = GetAdditionalRecords(closestAuthority, false);
return(new DnsDatagram(request.Identifier, true, DnsOpcode.StandardQuery, false, false, request.RecursionDesired, true, false, false, DnsResponseCode.NoError, request.Question, null, closestAuthority, additional));
}
}
//no cached delegation found
return(null);
}
private void ResolveAdditionalRecords(DnsResourceRecord refRecord, string domain, bool serveStale, List <DnsResourceRecord> additionalRecords)
{
IReadOnlyList <DnsResourceRecord> glueRecords = refRecord.GetGlueRecords();
if (glueRecords.Count > 0)
{
bool added = false;
foreach (DnsResourceRecord glueRecord in glueRecords)
{
if (!glueRecord.IsStale)
{
added = true;
additionalRecords.Add(glueRecord);
}
}
if (added)
{
return;
}
}
CacheZone cacheZone = _root.FindZone(domain, out _, out _, out _);
if (cacheZone != null)
{
{
IReadOnlyList <DnsResourceRecord> records = cacheZone.QueryRecords(DnsResourceRecordType.A, serveStale, true);
if ((records.Count > 0) && (records[0].RDATA is DnsARecord))
{
additionalRecords.AddRange(records);
}
}
{
IReadOnlyList <DnsResourceRecord> records = cacheZone.QueryRecords(DnsResourceRecordType.AAAA, serveStale, true);
if ((records.Count > 0) && (records[0].RDATA is DnsAAAARecord))
{
additionalRecords.AddRange(records);
}
}
}
}
private void ResolveAdditionalRecords(string domain, bool serveStale, List <DnsResourceRecord> additionalRecords)
{
CacheZone cacheZone = _root.FindZone(domain, out _, out _, out _);
if (cacheZone != null)
{
{
IReadOnlyList <DnsResourceRecord> records = cacheZone.QueryRecords(DnsResourceRecordType.A, serveStale);
if ((records.Count > 0) && (records[0].RDATA is DnsARecord))
{
additionalRecords.AddRange(records);
}
}
{
IReadOnlyList <DnsResourceRecord> records = cacheZone.QueryRecords(DnsResourceRecordType.AAAA, serveStale);
if ((records.Count > 0) && (records[0].RDATA is DnsAAAARecord))
{
additionalRecords.AddRange(records);
}
}
}
}
