beginnings of a fully exposed dns class for c#

dns.cs

using System;
using System.Collections.Generic;
using System.Collections;
using System.ComponentModel;
using System.Linq;
using System.Text;

using System.Runtime.InteropServices;

namespace MACE_DataCollector_wrapper
{
    class dns
    {
        public class DnsQuerier
        {
            //http://www.eggheadcafe.com/articles/20050129.asp
            //more specifically: http://stackoverflow.com/a/5504091/843000
            
            private enum QueryOptions
            {
                //http://msdn.microsoft.com/en-us/library/cc982162(v=vs.85).aspx
                DNS_QUERY_STANDARD = 0x00000000,
                DNS_QUERY_ACCEPT_TRUNCATED_RESPONSE = 0x00000001,
                DNS_QUERY_USE_TCP_ONLY = 0x00000002,
                DNS_QUERY_NO_RECURSION = 0x00000004,
                DNS_QUERY_BYPASS_CACHE = 0x00000008,
                DNS_QUERY_NO_WIRE_QUERY = 0x00000010,
                DNS_QUERY_NO_LOCAL_NAME = 0x00000020,
                DNS_QUERY_NO_HOSTS_FILE = 0x00000040,
                DNS_QUERY_NO_NETBT = 0x00000080,
                DNS_QUERY_WIRE_ONLY = 0x00000100,
                DNS_QUERY_RETURN_MESSAGE = 0x00000200,
                DNS_QUERY_MULTICAST_ONLY = 0x00000400,
                DNS_QUERY_NO_MULTICAST = 0x00000800,
                DNS_QUERY_TREAT_AS_FQDN = 0x00001000,
                DNS_QUERY_ADDRCONFIG = 0x00002000,
                DNS_QUERY_DUAL_ADDR = 0x00004000,
                DNS_QUERY_MULTICAST_WAIT = 0x00020000,
                DNS_QUERY_MULTICAST_VERIFY = 0x00040000,
                DNS_QUERY_DONT_RESET_TTL_VALUES = 0x00100000,
                DNS_QUERY_DISABLE_IDN_ENCODING = 0x00200000,
                DNS_QUERY_APPEND_MULTILABEL = 0x00800000,
                DNS_QUERY_RESERVED = 0xf0000000,

            }

            private enum RecordTypes
            {
                //http://msdn.microsoft.com/en-us/library/cc982162(v=vs.85).aspx
                DNS_TYPE_A = 0x0001,
                DNS_TYPE_NS = 0x0002,
                DNS_TYPE_MD = 0x0003,
                DNS_TYPE_MF = 0x0004,
                DNS_TYPE_CNAME = 0x0005,
                DNS_TYPE_SOA = 0x0006,
                DNS_TYPE_MB = 0x0007,
                DNS_TYPE_MG = 0x0008,
                DNS_TYPE_MR = 0x0009,
                DNS_TYPE_NULL = 0x000a,
                DNS_TYPE_WKS = 0x000b,
                DNS_TYPE_PTR = 0x000c,
                DNS_TYPE_HINFO = 0x000d,
                DNS_TYPE_MINFO = 0x000e,
                DNS_TYPE_MX = 0x000f,
                DNS_TYPE_TEXT = 0x0010,
                DNS_TYPE_RP = 0x0011,
                DNS_TYPE_AFSDB = 0x0012,
                DNS_TYPE_X25 = 0x0013,
                DNS_TYPE_ISDN = 0x0014,
                DNS_TYPE_RT = 0x0015,
                DNS_TYPE_NSAP = 0x0016,
                DNS_TYPE_NSAPPTR = 0x0017,
                DNS_TYPE_SIG = 0x0018,
                DNS_TYPE_KEY = 0x0019,
                DNS_TYPE_PX = 0x001a,
                DNS_TYPE_GPOS = 0x001b,
                DNS_TYPE_AAAA = 0x001c,
                DNS_TYPE_LOC = 0x001d,
                DNS_TYPE_NXT = 0x001e,
                DNS_TYPE_EID = 0x001f,
                DNS_TYPE_NIMLOC = 0x0020,
                DNS_TYPE_SRV = 0x0021,
                DNS_TYPE_ATMA = 0x0022,
                DNS_TYPE_NAPTR = 0x0023,
                DNS_TYPE_KX = 0x0024,
                DNS_TYPE_CERT = 0x0025,
                DNS_TYPE_A6 = 0x0026,
                DNS_TYPE_DNAME = 0x0027,
                DNS_TYPE_SINK = 0x0028,
                DNS_TYPE_OPT = 0x0029,
                DNS_TYPE_DS = 0x002B,
                DNS_TYPE_RRSIG = 0x002E,
                DNS_TYPE_NSEC = 0x002F,
                DNS_TYPE_DNSKEY = 0x0030,
                DNS_TYPE_DHCID = 0x0031,
                DNS_TYPE_UINFO = 0x0064,
                DNS_TYPE_UID = 0x0065,
                DNS_TYPE_GID = 0x0066,
                DNS_TYPE_UNSPEC = 0x0067,
                DNS_TYPE_ADDRS = 0x00f8,
                DNS_TYPE_TKEY = 0x00f9,
                DNS_TYPE_TSIG = 0x00fa,
                DNS_TYPE_IXFR = 0x00fb,
                DNS_TYPE_AXFR = 0x00fc,
                DNS_TYPE_MAILB = 0x00fd,
                DNS_TYPE_MAILA = 0x00fe,
                DNS_TYPE_ALL = 0x00ff,
                DNS_TYPE_ANY = 0x00ff,
                DNS_TYPE_WINS = 0xff01,
                DNS_TYPE_WINSR = 0xff02,
                DNS_TYPE_NBSTAT = DNS_TYPE_WINSR
            }

            [DllImport("dnsapi", EntryPoint = "DnsQuery_W", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
            private static extern int DnsQuery([MarshalAs(UnmanagedType.VBByRefStr)]ref string pszName, RecordTypes wType, QueryOptions options, int aipServers, ref IntPtr ppQueryResults, int pReserved);

            [DllImport("dnsapi", CharSet = CharSet.Auto, SetLastError = true)]
            private static extern void DnsRecordListFree(IntPtr pRecordList, int FreeType);

            public static string[] GetMXRecords(string domain)
            {

                IntPtr ptr1 = IntPtr.Zero;
                IntPtr ptr2 = IntPtr.Zero;
                MXRecord recMx;
                if (Environment.OSVersion.Platform != PlatformID.Win32NT)
                {
                    throw new NotSupportedException();
                }
                ArrayList list1 = new ArrayList();
                int num1 = DnsQuerier.DnsQuery(ref domain, RecordTypes.DNS_TYPE_MX, QueryOptions.DNS_QUERY_BYPASS_CACHE, 0, ref ptr1, 0);
                if (num1 != 0)
                {
                    throw new Win32Exception(num1);
                }
                for (ptr2 = ptr1; !ptr2.Equals(IntPtr.Zero); ptr2 = recMx.pNext)
                {
                    recMx = (MXRecord)Marshal.PtrToStructure(ptr2, typeof(MXRecord));
                    if (recMx.wType == 15)
                    {
                        string text1 = Marshal.PtrToStringAuto(recMx.pNameExchange);
                        list1.Add(text1);
                    }
                }
                DnsQuerier.DnsRecordListFree(ptr2, 0);
                return (string[])list1.ToArray(typeof(string));
            }
            /*
            public static string[] GetARecords(string domain)
            {

                IntPtr ptr1 = IntPtr.Zero;
                IntPtr ptr2 = IntPtr.Zero;
                ARecord recA;
                if (Environment.OSVersion.Platform != PlatformID.Win32NT)
                {
                    throw new NotSupportedException();
                }
                ArrayList list1 = new ArrayList();
                int num1 = DnsQuerier.DnsQuery(ref domain, RecordTypes.DNS_TYPE_MX, QueryOptions.DNS_QUERY_BYPASS_CACHE, 0, ref ptr1, 0);
                if (num1 != 0)
                {
                    throw new Win32Exception(num1);
                }
                for (ptr2 = ptr1; !ptr2.Equals(IntPtr.Zero); ptr2 = recMx.pNext)
                {
                    recMx = (MXRecord)Marshal.PtrToStructure(ptr2, typeof(MXRecord));
                    if (recMx.wType == 15)
                    {
                        string text1 = Marshal.PtrToStringAuto(recMx.pNameExchange);
                        list1.Add(text1);
                    }
                }
                DnsQuerier.DnsRecordListFree(ptr2, 0);
                return (string[])list1.ToArray(typeof(string));
            }
            */

            [StructLayout(LayoutKind.Sequential)]
            //http://msdn.microsoft.com/en-us/library/ms682082(v=vs.85).aspx
            private struct MXRecord
            {
                public IntPtr pNext;
                public string pName;
                public short wType;
                public short wDataLength;
                public int flags;
                public int dwTtl;
                public int dwReserved;

                //type specific stuff:
                // http://msdn.microsoft.com/en-us/library/ms682070(v=vs.85).aspx
                public IntPtr pNameExchange;
                public short wPreference;
                public short Pad;
            }

            [StructLayout(LayoutKind.Sequential)]
            private struct ARecord
            {
                public IntPtr pNext;
                public string pName;
                public short wType;
                public short wDataLength;
                public int flags;
                public int dwTtl;
                public int dwReserved;

                //type specific stuff:
                // http://msdn.microsoft.com/en-us/library/ms682044(v=vs.85).aspx
                // IP4_ADDRESS data typs is only supported in windns.h Windows 8+: http://msdn.microsoft.com/en-us/library/cc982163(v=vs.85).aspx
                // it is a dword http://stackoverflow.com/a/5490439/843000
                public uint IpAddress;
            }
        }
    }
}