public void RecursiveResolveDomainName(DnsCache cache = null, NetProxy proxy = null, bool preferIPv6 = false, DnsTransportProtocol protocol = DnsTransportProtocol.Udp, int retries = 2, int timeout = 2000, DnsTransportProtocol recursiveResolveProtocol = DnsTransportProtocol.Udp) { if (_ipEndPoint != null) { try { DnsDatagram nsResponse = DnsClient.RecursiveResolve(new DnsQuestionRecord(_ipEndPoint.Address, DnsClass.IN), null, cache, proxy, preferIPv6, protocol, retries, timeout, recursiveResolveProtocol); if ((nsResponse.Header.RCODE == DnsResponseCode.NoError) && (nsResponse.Answer.Length > 0) && (nsResponse.Answer[0].Type == DnsResourceRecordType.PTR)) { _domainEndPoint = new DomainEndPoint((nsResponse.Answer[0].RDATA as DnsPTRRecord).PTRDomainName, _ipEndPoint.Port); } } catch { } } }
public void RecursiveResolveIPAddress(DnsCache cache = null, NetProxy proxy = null, bool preferIPv6 = false, DnsTransportProtocol protocol = DnsTransportProtocol.Udp, int retries = 2, int timeout = 2000, DnsTransportProtocol recursiveResolveProtocol = DnsTransportProtocol.Udp) { lock (_ipEndPointResolverLock) { if (_ipEndPointExpires && (DateTime.UtcNow < _ipEndPointExpiresOn)) { return; } string domain; if (_dohEndPoint != null) { domain = _dohEndPoint.Host; } else if (_domainEndPoint != null) { domain = _domainEndPoint.Address; } else { return; } if (domain == "localhost") { _ipEndPoint = new IPEndPoint((preferIPv6 ? IPAddress.IPv6Loopback : IPAddress.Loopback), this.Port); return; } if (IPAddress.TryParse(domain, out IPAddress address)) { _ipEndPoint = new IPEndPoint(address, this.Port); return; } IPEndPoint ipEndPoint = null; DateTime ipEndPointExpiresOn = DateTime.MinValue; if (preferIPv6) { DnsDatagram nsResponse = DnsClient.RecursiveResolve(new DnsQuestionRecord(domain, DnsResourceRecordType.AAAA, DnsClass.IN), null, cache, proxy, true, protocol, retries, timeout, recursiveResolveProtocol); if ((nsResponse.Header.RCODE == DnsResponseCode.NoError) && (nsResponse.Answer.Length > 0) && (nsResponse.Answer[0].Type == DnsResourceRecordType.AAAA)) { ipEndPoint = new IPEndPoint((nsResponse.Answer[0].RDATA as DnsAAAARecord).Address, this.Port); ipEndPointExpiresOn = DateTime.UtcNow.AddSeconds(nsResponse.Answer[0].TtlValue); } } if (ipEndPoint == null) { DnsDatagram nsResponse = DnsClient.RecursiveResolve(new DnsQuestionRecord(domain, DnsResourceRecordType.A, DnsClass.IN), null, cache, proxy, false, protocol, retries, timeout, recursiveResolveProtocol); if ((nsResponse.Header.RCODE == DnsResponseCode.NoError) && (nsResponse.Answer.Length > 0) && (nsResponse.Answer[0].Type == DnsResourceRecordType.A)) { ipEndPoint = new IPEndPoint((nsResponse.Answer[0].RDATA as DnsARecord).Address, this.Port); ipEndPointExpiresOn = DateTime.UtcNow.AddSeconds(nsResponse.Answer[0].TtlValue); } } if (ipEndPoint == null) { throw new DnsClientException("No IP address was found for name server: " + domain); } _ipEndPoint = ipEndPoint; _ipEndPointExpires = true; _ipEndPointExpiresOn = ipEndPointExpiresOn; } }