done

Netch/3rd/DnsClient.NET/Interop/Windows/IpHlpApi/FixedNetworkInformation.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Net;
+using System.Runtime.InteropServices;
+
+#if !NET45
+
+namespace DnsClient.Windows.IpHlpApi
+{
+    internal class FixedNetworkInformation
+    {
+        private FixedNetworkInformation()
+        {
+        }
+
+        public ICollection<IPAddress> DnsAddresses { get; private set; }
+
+        public string DomainName { get; private set; }
+
+        public string HostName { get; private set; }
+
+        public static FixedNetworkInformation GetFixedInformation()
+        {
+            var info = new FixedNetworkInformation();
+            uint size = 0;
+            DisposableIntPtr buffer = null;
+            Interop.IpHlpApi.FIXED_INFO fixedInfo = new Interop.IpHlpApi.FIXED_INFO();
+
+            uint result = Interop.IpHlpApi.GetNetworkParams(IntPtr.Zero, ref size);
+
+            while (result == Interop.IpHlpApi.ERROR_BUFFER_OVERFLOW)
+            {
+                using (buffer = DisposableIntPtr.Alloc((int)size))
+                {
+                    if (buffer.IsValid)
+                    {
+                        result = Interop.IpHlpApi.GetNetworkParams(buffer.Ptr, ref size);
+                        if (result == Interop.IpHlpApi.ERROR_SUCCESS)
+                        {
+                            fixedInfo = Marshal.PtrToStructure<Interop.IpHlpApi.FIXED_INFO>(buffer.Ptr);
+                        }
+                        else
+                        {
+                            throw new Win32Exception((int)result);
+                        }
+
+                        var dnsAddresses = new List<IPAddress>();
+                        Interop.IpHlpApi.IP_ADDR_STRING addr = fixedInfo.DnsServerList;
+                        IPAddress ip;
+
+                        if (IPAddress.TryParse(addr.IpAddress, out ip))
+                        {
+                            dnsAddresses.Add(ip);
+
+                            while (addr.Next != IntPtr.Zero)
+                            {
+                                addr = Marshal.PtrToStructure<Interop.IpHlpApi.IP_ADDR_STRING>(addr.Next);
+                                if (IPAddress.TryParse(addr.IpAddress, out ip))
+                                {
+                                    dnsAddresses.Add(ip);
+                                }
+                            }
+                        }
+
+                        info.HostName = fixedInfo.hostName;
+                        info.DomainName = fixedInfo.domainName;
+                        info.DnsAddresses = dnsAddresses.ToArray();
+
+                        return info;
+                    }
+                    else
+                    {
+                        throw new OutOfMemoryException();
+                    }
+                }
+            }
+
+            return info;
+        }
+    }
+}
+#endif

Netch/3rd/DnsClient.NET/Interop/Windows/IpHlpApi/Interop.IpHlpApi.cs

@@ -0,0 +1,70 @@
+using System;
+using System.Net.Sockets;
+using System.Runtime.InteropServices;
+
+internal static partial class Interop
+{
+    internal static partial class IpHlpApi
+    {
+        internal const uint ERROR_SUCCESS = 0;
+        internal const uint ERROR_INVALID_FUNCTION = 1;
+        internal const uint ERROR_NO_SUCH_DEVICE = 2;
+        internal const uint ERROR_INVALID_DATA = 13;
+        internal const uint ERROR_INVALID_PARAMETER = 87;
+        internal const uint ERROR_BUFFER_OVERFLOW = 111;
+        internal const uint ERROR_INSUFFICIENT_BUFFER = 122;
+        internal const uint ERROR_NO_DATA = 232;
+        internal const uint ERROR_IO_PENDING = 997;
+        internal const uint ERROR_NOT_FOUND = 1168;
+
+        [DllImport(Libraries.IpHlpApi)]
+        internal extern static uint GetAdaptersAddresses(
+            AddressFamily family,
+            uint flags,
+            IntPtr pReserved,
+            IntPtr adapterAddresses,
+            ref uint outBufLen);
+
+        [DllImport(Libraries.IpHlpApi, ExactSpelling = true)]
+        internal extern static uint GetNetworkParams(IntPtr pFixedInfo, ref uint pOutBufLen);
+
+        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
+        internal struct FIXED_INFO
+        {
+            public const int MAX_HOSTNAME_LEN = 128;
+            public const int MAX_DOMAIN_NAME_LEN = 128;
+            public const int MAX_SCOPE_ID_LEN = 256;
+
+            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_HOSTNAME_LEN + 4)]
+            public string hostName;
+
+            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_DOMAIN_NAME_LEN + 4)]
+            public string domainName;
+
+            public IntPtr currentDnsServer; // IpAddressList*
+            public IP_ADDR_STRING DnsServerList;
+            public uint nodeType;
+
+            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_SCOPE_ID_LEN + 4)]
+            public string scopeId;
+
+            public bool enableRouting;
+            public bool enableProxy;
+            public bool enableDns;
+        }
+
+        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
+        internal struct IP_ADDR_STRING
+        {
+            public IntPtr Next; // struct _IpAddressList*
+
+            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 16)]
+            public string IpAddress;
+
+            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 16)]
+            public string IpMask;
+
+            public uint Context;
+        }
+    }
+}