private IPAddress[] GetDnsRecords(string hostName, IPAddress dnsServer)
{
IntPtr ptr = default(IntPtr);
List <IPAddress> list = new List <IPAddress>();
IntPtr zero = IntPtr.Zero;
IPv4Array iPv4ArrayFromIPAddress = GetIPv4ArrayFromIPAddress(dnsServer);
if (DnsQueryA(hostName, 1, 72, ref iPv4ArrayFromIPAddress, ref ptr, ref zero) == 0)
{
DnsRecordA dnsRecordA = (DnsRecordA)Marshal.PtrToStructure(ptr, typeof(DnsRecordA));
IPAddress addressFromRecord = GetAddressFromRecord(dnsRecordA);
if (addressFromRecord != IPAddress.None)
{
list.Add(addressFromRecord);
}
while (!(dnsRecordA.NextRecord == IntPtr.Zero))
{
dnsRecordA = (DnsRecordA)Marshal.PtrToStructure(dnsRecordA.NextRecord, typeof(DnsRecordA));
addressFromRecord = GetAddressFromRecord(dnsRecordA);
if (addressFromRecord != IPAddress.None)
{
list.Add(addressFromRecord);
}
}
}
return(list.ToArray());
}
private IPv4Array GetIPv4ArrayFromIPAddress(IPAddress address)
{
IPv4Array result = default(IPv4Array);
if (address != null)
{
result.Count = 1;
result.Addresses = new uint[1]
{
BitConverter.ToUInt32(address.GetAddressBytes(), 0)
};
}
return(result);
}
private static extern int DnsQueryA(string hostName, short type, int options, ref IPv4Array dnsServers, ref IntPtr recordList, ref IntPtr reserved);
