Public/Get-ALHDSDomainController.ps1

<#PSScriptInfo
 
.VERSION 1.0.1
 
.GUID e6e6b2bd-ffa8-4c53-a1fe-f383723729e1
 
.AUTHOR Dieter Koch
 
.COMPANYNAME
 
.COPYRIGHT (c) Dieter Koch
 
.TAGS
 
.LICENSEURI https://github.com/admins-little-helper/ALH/blob/main/LICENSE
 
.PROJECTURI https://github.com/admins-little-helper/ALH
 
.ICONURI
 
.EXTERNALMODULEDEPENDENCIES
 
.REQUIREDSCRIPTS
 
.EXTERNALSCRIPTDEPENDENCIES
 
.RELEASENOTES
    1.0.0
    Initial release
 
    1.0.1
    Changed type for parameter DomainName
 
#>



<#
 
.DESCRIPTION
 Function to query Active Directory Domain Controller based on DsGetDcName function
 https://docs.microsoft.com/en-us/windows/win32/api/dsgetdc/nf-dsgetdc-dsgetdcnamea
 
 Based on script from Jordan Borean (Jordan Borean (@jborean93) <jborean93@gmail.com>)
 https://gist.github.com/jborean93/6c3d8b64aa994c2676c6cc249bbf8833
 
 #>




function Get-ALHDSDomainController {
    <#
    .SYNOPSIS
        Locate a domain controller.
 
    .DESCRIPTION
        Locates a domain controller and returns the name and some additional information for about it.
 
    .PARAMETER DomainName
        The name of the Active Directory domain to search a DC for.
 
    .PARAMETER Server
        The name of the server to run the search from.
 
    .PARAMETER DomainGuid
        The GUID of the domain to find. This is used if the DC cannot be found by DomainName.
 
    .PARAMETER SiteName
        The name of the site where the DC should exist.
 
    .PARAMETER DirectoryServiceRequired
        Require the DC to support directory services.
 
    .PARAMETER DirectoryServicePreferred
        Prioritise DCs that support directory services over ones that do not.
 
    .PARAMETER GlobalCatalogRequired
        Require the DC to be a global catalog server for the forest of domains with this domain as the root.
 
    .PARAMETER PrimaryDCRequired
        Finds the DC that is the primary domain controller for the domain.
 
    .PARAMETER NoCache
        Forces cached information to be ignored.
 
    .PARAMETER UseCache
        Always use the cached information even when the function would normally refresh the data.
 
    .PARAMETER IpRequired
        The DC must have an IP address.
 
    .PARAMETER KdcRequired
        The DC must be a kerberos key distribution center.
 
    .PARAMETER TimeservRequired
        Requires the DC be currently running the Windows Time Service.
 
    .PARAMETER WritableRequired
        The DC must be writable and not a read only copy.
 
    .PARAMETER GoodTimeservPreferred
        Finds a DC that is a reliable time server.
 
    .PARAMETER AvoidSelf
        When calling from a domain controller, specified that the returned DC should not be the current host.
 
    .PARAMETER OnlyLdapNeeded
        Find a host that is an LDAP server and not necessarily a DC.
 
    .PARAMETER IsFlatName
        The -DomainName value is a flag name, e.g. DOMAIN. This cannot be combined with IsDnsName.
 
    .PARAMETER IsDnsName
        The -DomainName value is a DNS name, e.g. domain.com. This cannot be combined with IsFlagName.
 
    .PARAMETER TryNextClosestSite
        Attempt to find a DC in the same site but if nothing is found try the next closest site.
 
    .PARAMETER WebServiceRequired
        Requires the DC to be running the Active Directory web service.
 
    .PARAMETER Server2008OrLater
        DC must be running Windows Server 2008 or later.
 
    .PARAMETER Server2012OrLater
        DC must be running Windows Server 2012 or later.
 
    .PARAMETER Server2012R2OrLater
        DC must be running Windows Server 2012 R2 or later.
 
    .PARAMETER Server2016OrLater
        DC must be running Windows Server 2016 or later.
 
    .PARAMETER ReturnDnsName
        Returns the DNS names for Name and DomainName. This cannot be combined with ReturnFlatName.
 
    .PARAMETER ReturnFlatName
        Returns the flag name for Name and DOmain Name. This cannot be combined with ReturnDnsName.
 
    .EXAMPLE
        Get-ALHDSDomainController
 
    .INPUTS
        None
 
    .OUTPUTS
        Nothing
 
    .NOTES
        Author: Dieter Koch
        Email: diko@admins-little-helper.de
 
    .LINK
        https://github.com/admins-little-helper/ALH/blob/main/Help/Get-ALHDSDomainController.txt
    #>


    [CmdletBinding()]
    param (
        [String]
        $DomainName = (Get-CimInstance -ClassName "Win32_ComputerSystem").Domain,

        [String]
        $Server,

        [Nullable[Guid]]
        [AllowNull()]
        $DomainGuid = $null,

        [String]
        $SiteName,

        [Switch]
        $DirectoryServiceRequired,

        [Switch]
        $DirectoryServicePreferred,

        [Switch]
        $GlobalCatalogRequired,

        [Switch]
        $PrimaryDCRequired,

        [Switch]
        $NoCache,

        [Switch]
        $UseCache,

        [Switch]
        $IpRequired,

        [Switch]
        $KdcRequired,

        [Switch]
        $TimeservRequired,

        [Switch]
        $WritableRequired,

        [Switch]
        $GoodTimeservPreferred,

        [Switch]
        $AvoidSelf,

        [Switch]
        $OnlyLdapNeeded,

        [Switch]
        $IsFlatName,

        [Switch]
        $IsDnsName,

        [Switch]
        $TryNextClosestSite,

        [Switch]
        $WebServiceRequired,

        [Switch]
        $Server2008OrLater,

        [Switch]
        $Server2012OrLater,

        [Switch]
        $Server2012R2OrLater,

        [Switch]
        $Server2016OrLater,

        [Switch]
        $ReturnDnsName,

        [Switch]
        $ReturnFlatName
    )

    Add-Type -TypeDefinition @'
using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
 
namespace NetApi
{
    public class NativeHelpers
    {
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
        public struct DOMAIN_CONTROLLER_INFOW
        {
            public string DomainControllerName;
            public string DomainControllerAddress;
            public DCAddressType DomainControllerAddressType;
            public Guid DomainGuid;
            public string DomainName;
            public string DnsForestName;
            public DCFlags Flags;
            public string DcSiteName;
            public string ClientSiteName;
        }
    }
 
    public class NativeMethods
    {
        [DllImport("NetApi32.dll", CharSet = CharSet.Unicode)]
        private static extern Int32 DsGetDcNameW(
            string ComputerName,
            string DomainName,
            IntPtr DomainGuid,
            string SiteName,
            GetDcFlags Flags,
            out IntPtr DomainControllerInfo);
 
        [DllImport("NetApi32.dll")]
        private static extern Int32 NetApiBufferFree(
            IntPtr Buffer);
 
        public static ALHDSDCInfo DsGetDcName(string domainName, string computerName = null, string siteName = null,
            GetDcFlags flags = GetDcFlags.None, Guid? domainGuid = null)
        {
            IntPtr rawInfo;
            IntPtr domainGuidPtr = IntPtr.Zero;
            try
            {
                if (domainGuid != null)
                {
                    byte[] guidBytes = ((Guid)domainGuid).ToByteArray();
                    domainGuidPtr = Marshal.AllocHGlobal(guidBytes.Length);
                    Marshal.Copy(guidBytes, 0, domainGuidPtr, guidBytes.Length);
                }
 
                Int32 res = DsGetDcNameW(computerName, domainName, domainGuidPtr, siteName, flags, out rawInfo);
                if (res != 0)
                    throw new Win32Exception(res);
            }
            finally
            {
                if (domainGuidPtr != IntPtr.Zero)
                    Marshal.FreeHGlobal(domainGuidPtr);
            }
 
            try
            {
                var info = (NativeHelpers.DOMAIN_CONTROLLER_INFOW)Marshal.PtrToStructure(rawInfo,
                    typeof(NativeHelpers.DOMAIN_CONTROLLER_INFOW));
 
                return new ALHDSDCInfo()
                {
                    Name = info.DomainControllerName,
                    Address = info.DomainControllerAddress,
                    AddressType = info.DomainControllerAddressType,
                    DomainGuid = info.DomainGuid,
                    DomainName = info.DomainName,
                    DnsForestName = info.DnsForestName,
                    Flags = info.Flags,
                    DcSiteName = info.DcSiteName,
                    ClientSiteName = info.ClientSiteName,
                };
            }
            finally
            {
                NetApiBufferFree(rawInfo);
            }
        }
    }
 
    public class ALHDSDCInfo
    {
        public string Name { get; internal set; }
        public string Address { get; internal set; }
        public DCAddressType AddressType { get; internal set; }
        public Guid DomainGuid { get; internal set; }
        public string DomainName { get; internal set; }
        public string DnsForestName { get; internal set; }
        public DCFlags Flags { get; internal set; }
        public string DcSiteName { get; internal set; }
        public string ClientSiteName { get; internal set; }
    }
 
    public enum DCAddressType : uint
    {
        INetAddress = 1,
        NetbiosAddress = 2,
    }
 
    [Flags]
    public enum DCFlags : uint
    {
        Pdc = 0x00000001,
        Gc = 0x00000004,
        Ldap = 0x00000008,
        Ds = 0x00000010,
        Kdc = 0x00000020,
        Timeserv = 0x00000040,
        Closest = 0x00000080,
        Writable = 0x00000100,
        GoodTimeserv = 0x00000200,
        Ndnc = 0x00000400,
        SelectSecretDomain6 = 0x00000800,
        FullSecretDomain6 = 0x00001000,
        Ws = 0x00002000,
        Ds8 = 0x00004000,
        Ds9 = 0x00008000,
        Ds10 = 0x00010000,
        Ping = 0x000FFFFF,
        DnsController = 0x20000000,
        DnsDOmain = 0x40000000,
        DnsForest = 0x80000000,
    }
 
    [Flags]
    public enum GetDcFlags : uint
    {
        None = 0x00000000,
        ForceRediscovery = 0x00000001,
        DirectoryServiceRequired = 0x00000010,
        DirectoryServicePreferred = 0x00000020,
        GcServerRequired = 0x00000040,
        PdcRequired = 0x00000080,
        BackgroundOnly = 0x00000100,
        IpRequired = 0x00000200,
        KdcRequired = 0x00000400,
        TimeservRequired = 0x00000800,
        WritableRequired = 0x00001000,
        GoodTimeservPreferred = 0x00002000,
        AvoidSelf = 0x00004000,
        OnlyLdapNeeded = 0x00008000,
        IsFlatName = 0x00010000,
        IsDnsName = 0x00020000,
        TryNextClosestSite = 0x00040000,
        DirectoryService6Required = 0x00080000,
        WebServiceRequired = 0x00100000,
        DirectoryService8Required = 0x00200000,
        DirectoryService9Required = 0x00400000,
        DirectoryService10Required = 0x00800000,
        ReturnDnsName = 0x40000000,
        ReturnFlatName = 0x80000000,
    }
}
'@


    $ServerValue = if ($Server) { $Server } else { [NullString]::Value }
    $siteNameValue = if ($SiteName) { $SiteName } else { [NullString]::Value }
    [NetApi.GetDcFlags]$flags = [NetApi.GetDcFlags]::None

    if ($DirectoryServiceRequired) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::DirectoryServiceRequired
    }

    if ($DirectoryServicePreferred) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::DirectoryServicePreferred
    }

    if ($GlobalCatalogRequired) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::GcServerRequired
    }

    if ($PrimaryDCRequired) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::PdcRequired
    }

    if ($NoCache) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::ForceRediscovery
    }

    if ($UseCache) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::BackgroundOnly
    }

    if ($IpRequired) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::IpRequired
    }

    if ($KdcRequired) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::KdcRequired
    }

    if ($TimeservRequired) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::TimeservRequired
    }

    if ($WritableRequired) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::WritableRequired
    }

    if ($GoodTimeservPreferred) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::GoodTimeservPreferred
    }

    if ($AvoidSelf) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::AvoidSelf
    }

    if ($OnlyLdapNeeded) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::OnlyLdapNeeded
    }

    if ($IsFlatName) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::IsFlatName
    }

    if ($IsDnsName) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::IsDnsName
    }

    if ($TryNextClosestSite) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::TryNextClosestSite
    }

    if ($WebServiceRequired) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::WebServiceRequired
    }

    if ($Server2008OrLater) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::DirectoryService6Required
    }

    if ($Server2012OrLater) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::DirectoryService8Required
    }

    if ($Server2012R2OrLater) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::DirectoryService9Required
    }

    if ($Server2016OrLater) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::DirectoryService10Required
    }

    if ($ReturnDnsName) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::ReturnDnsName
    }

    if ($ReturnFlatName) {
        $flags = [UInt32]$flags -bor [UInt32][NetApi.GetDcFlags]::ReturnFlatName
    }

    if ($IsDnsName -and $IsFlatName) {
        Write-Error -Message "Cannot specify IsDnsName and IsFlatName together" -Category InvalidArgument
        return
    }

    if ($ReturnDnsName -and $ReturnFlatName) {
        Write-Error -Message "Cannot specify ReturnDnsName and ReturnFlatName together" -Category InvalidArgument
        return
    }

    $ReturnVal = [NetApi.NativeMethods]::DsGetDcName(
        $DomainName,
        $ServerValue,
        $siteNameValue,
        $flags,
        $DomainGuid
    )

    $ReturnVal.PSObject.TypeNames.Insert(0, "ALHDSDCInfo")
    $ReturnVal
}

#region EndOfScript
<#
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# | |__ _ __ __| | ___ | |_ | (___ ___ _ __ _ _ __ | |_
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# | |____| | | | (_| | | (_) | | ____) | (__| | | | |_) | |_
# |______|_| |_|\__,_| \___/|_| |_____/ \___|_| |_| .__/ \__|
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# created with help of http://patorjk.com/software/taag/
#>

#endregion