Enumerate a list of machines in the local workgroup or domain

Category:

Network/Internet

Type:

Classes

Difficulty:

Advanced

Author: Anonymous

Version Compatibility: Visual Basic.NET

More information:

This class allows you to enumerate a list of machines and the services they offer in the local domain and/or workgroup. This can be used to offer a browse list of boxes on the network, or to search for specific services running (like only showing a list of SQL Servers.)

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
' (None)

Code:

Imports System.Runtime.InteropServices

Public Class MasterBrowseList

Private Const MAX_PREFERRED_LENGTH As Integer = -1&
    Private Const NERR_SUCCESS As Long = 0&
    Private Const ERROR_MORE_DATA As Long = 234&
    Private Const SV_TYPE_WORKSTATION As Long = &H1
    Private Const SV_TYPE_SERVER As Long = &H2
    Private Const SV_TYPE_SQLSERVER As Long = &H4
    Private Const SV_TYPE_DOMAIN_CTRL As Long = &H8
    Private Const SV_TYPE_DOMAIN_BAKCTRL As Long = &H10
    Private Const SV_TYPE_TIME_SOURCE As Long = &H20
    Private Const SV_TYPE_AFP As Long = &H40
    Private Const SV_TYPE_NOVELL As Long = &H80
    Private Const SV_TYPE_DOMAIN_MEMBER As Long = &H100
    Private Const SV_TYPE_PRINTQ_SERVER As Long = &H200
    Private Const SV_TYPE_DIALIN_SERVER As Long = &H400
    Private Const SV_TYPE_XENIX_SERVER As Long = &H800
    Private Const SV_TYPE_SERVER_UNIX As Long = SV_TYPE_XENIX_SERVER
    Private Const SV_TYPE_NT As Long = &H1000
    Private Const SV_TYPE_WFW As Long = &H2000
    Private Const SV_TYPE_SERVER_MFPN As Long = &H4000
    Private Const SV_TYPE_SERVER_NT As Long = &H8000
    Private Const SV_TYPE_POTENTIAL_BROWSER As Long = &H10000
    Private Const SV_TYPE_BACKUP_BROWSER As Long = &H20000
    Private Const SV_TYPE_MASTER_BROWSER As Long = &H40000
    Private Const SV_TYPE_DOMAIN_MASTER As Long = &H80000
    Private Const SV_TYPE_SERVER_OSF As Long = &H100000
    Private Const SV_TYPE_SERVER_VMS As Long = &H200000
    Private Const SV_TYPE_WINDOWS As Long = &H400000              'Windows95 +
    Private Const SV_TYPE_DFS As Long = &H800000                  'Root of a DFS tree
    Private Const SV_TYPE_CLUSTER_NT As Long = &H1000000          'NT Cluster
    Private Const SV_TYPE_TERMINALSERVER As Long = &H2000000      'Terminal Server
    Private Const SV_TYPE_DCE As Long = &H10000000                'IBM DSS
    Private Const SV_TYPE_ALTERNATE_XPORT As Long = &H20000000    'return alternate transport
    Private Const SV_TYPE_LOCAL_LIST_ONLY As Long = &H40000000    'return local only
    Private Const SV_TYPE_DOMAIN_ENUM As Long = &H80000000
    Private Const SV_TYPE_ALL As Long = &HFFFFFFFF
    Private Const MAJOR_VERSION_MASK As Long = &HF

Private Structure SERVER_INFO_101
        Dim PlatformID As Integer
        Dim Name As IntPtr
        Dim VersionMajor As Integer
        Dim VersionMinor As Integer
        Dim Type As Integer
        Dim Comment As IntPtr
    End Structure

Private Declare Auto Function NetApiBufferFree Lib "netapi32.dll" (ByVal bufptr As IntPtr) As Integer

Private Declare Auto Function NetServerEnum Lib "netapi32.dll" _
                                        (ByVal nullptr As Integer, _
                                        ByVal Level As Integer, _
                                        ByRef BufPtr As IntPtr, _
                                        ByVal BufMaxLen As Integer, _
                                        ByRef EntriesRead As Integer, _
                                        ByRef TotalEntries As Integer, _
                                        ByVal ServerType As Integer, _
                                        ByVal Domain As IntPtr, _
                                        ByVal ResumeHandle As Integer) As Integer

Public Enum MACHINEPLATFORM As Integer
        DOS = 300
        OS2 = 400
        NT_2K_XP = 500
        OSF = 600
        VMS = 700
    End Enum

<Flags()> Public Enum MACHINETYPE As Integer
        Workstation = &H1
        Server = &H2
        SQLServer = &H4
        DomainController = &H8
        BackupDomainController = &H10
        TimeSource = &H20
        AppleFileProtocolServer = &H40
        NovellServer = &H80
        DomainMember = &H100
        PrintServer = &H200
        DialinServer = &H400
        UnixOrXenix = &H800
        NT_2K_XP = &H1000
        WinForWorkgroups = &H2000
        ServerFilePrintForNetware = &H4000
        ServerNT = &H8000
        PotentialBrowser = &H10000
        BackupBrowser = &H20000
        MasterBrowser = &H40000
        DomainMaster = &H80000
        ServerOSF = &H100000
        ServerVMS = &H200000
        Windows95OrHigher = &H400000
        DFSRoot = &H800000
        ClusterNode = &H1000000
        TerminalServer = &H2000000
        ClusterVirtualServer = &H4000000
    End Enum

Public Structure MACHINE
        Dim Platform As MACHINEPLATFORM
        Dim Name As String
        Dim VersionMajor As Integer
        Dim VersionMinor As Integer
        Dim TypeBits As MACHINETYPE
        Dim Comment As String
    End Structure

Public Shared Function GetMasterBrowseList() As MACHINE()
        Return GetMasterBrowseList(Nothing)
    End Function

Public Shared Function GetMasterBrowseList(ByVal Domain As String) As MACHINE()
        Dim BrowseList As New ArrayList

Dim BufPtr As IntPtr
        Dim se101 As SERVER_INFO_101
        Dim StructSize As Integer = Marshal.SizeOf(se101)

Dim EntriesRead As Integer
        Dim TotalEntries As Integer
        Dim ServerType As Integer = SV_TYPE_WORKSTATION Or SV_TYPE_SERVER
        Dim DomainPtr As IntPtr

If Domain Is Nothing Or Domain = "" Then
            DomainPtr = New IntPtr(0)
        Else
            'we are faking a constant string here with a BSTR by appending
            'a null character. we'll free it afterwards
            DomainPtr = Marshal.StringToBSTR(Domain & Chr(0))
        End If

Dim ret As Integer = NetServerEnum(0, _
                                        101, _
                                        BufPtr, _
                                        MAX_PREFERRED_LENGTH, _
                                        EntriesRead, _
                                        TotalEntries, _
                                        ServerType, _
                                        DomainPtr, _
                                        0)
        Marshal.FreeBSTR(DomainPtr)

Try
            If ret = NERR_SUCCESS Then
                Dim nextbufptr As IntPtr

For t As Integer = 0 To EntriesRead - 1
                    'copy memory chunk      OF SIZE StructSize
                    '                       FROM LOC bufptr + (StructSize + t)
                    '                       INTO LOC se101
                    nextbufptr = New IntPtr(BufPtr.ToInt32 + (StructSize * t))
                    se101 = Marshal.PtrToStructure(nextbufptr, GetType(SERVER_INFO_101))

Dim themachine As MACHINE
                    themachine.Name = Marshal.PtrToStringUni(se101.Name)
                    themachine.Comment = Marshal.PtrToStringUni(se101.Comment)
                    themachine.Platform = se101.PlatformID
                    themachine.TypeBits = se101.Type
                    themachine.VersionMajor = se101.VersionMajor And MAJOR_VERSION_MASK
                    themachine.VersionMinor = se101.VersionMinor

BrowseList.Add(themachine)
                Next
            End If
        Catch ex As Exception
            Throw ex
        Finally
            NetApiBufferFree(BufPtr)
        End Try

Return BrowseList.ToArray(GetType(MACHINE))

End Function

End Class