LanSpider/NetworkBrowser.cs

   1 using System;
   2 using System.Collections.Generic;
   3 using System.Runtime.InteropServices;
   4 using System.Security;
   5 using System.Windows.Forms;
   6
   7 namespace LanSpider
   8 {
   9     /// <summary>
  10     /// Gets a list of machines and open shares on LAN. Uses DllImport of Netapi32.dll.
  11     /// </summary>
  12     public sealed class NetworkBrowser
  13     {
  14         #region Dll Imports
  15
  16         /// <summary>
  17         /// Netapi32.dll : Get list of servers on the network.
  18         /// </summary>
  19         [DllImport( "Netapi32", CharSet = CharSet.Auto, SetLastError = true ), SuppressUnmanagedCodeSecurity]
  20         private static extern int NetServerEnum(
  21             string ServerNane, // must be null
  22             int dwLevel,
  23             ref IntPtr pBuf,
  24             int dwPrefMaxLen,
  25             out int dwEntriesRead,
  26             out int dwTotalEntries,
  27             int dwServerType,
  28             string domain, // null for login domain
  29             out int dwResumeHandle
  30             );
  31
  32         /// <summary>
  33         /// Netapi32.dll : Get list of shares on given machine.
  34         /// </summary>
  35         /// <returns></returns>
  36         [DllImport( "Netapi32", CharSet = CharSet.Auto, SetLastError = true ), SuppressUnmanagedCodeSecurity]
  37         private static extern int NetShareEnum(
  38             string servername,
  39             int level,
  40             ref IntPtr bufptr,
  41             int prefmaxlen,
  42             out int entriesread,
  43             out int totalentries,
  44             out int resume_handle
  45             );
  46
  47
  48         /// <summary>
  49         /// Netapi32.dll : The NetApiBufferFree function frees the memory
  50         /// that the NetApiBufferAllocate function allocates.
  51         /// Call NetApiBufferFree to free the memory that other network management functions return.
  52         /// </summary>
  53         [DllImport( "Netapi32", SetLastError = true ), SuppressUnmanagedCodeSecurity]
  54         private static extern int NetApiBufferFree(
  55             IntPtr pBuf );
  56
  57         /// <summary>
  58         /// ServerInfo structure holds information on network servers returned by <see cref="NetServerEnum"/>.
  59         /// </summary>
  60         [StructLayout( LayoutKind.Sequential )]
  61         private struct _SERVER_INFO_100
  62         {
  63             internal int sv100_platform_id;
  64             [MarshalAs( UnmanagedType.LPWStr )] internal string sv100_name;
  65         }
  66
  67         /// <summary>
  68         /// ShareInfo1 structure hold share infomation as returned by <see cref="NetShareEnum"/> level 1.
  69         /// </summary>
  70         [StructLayout( LayoutKind.Sequential )]
  71         private struct _SHARE_INFO_1
  72         {
  73             [MarshalAs( UnmanagedType.LPWStr )] internal string shi1_netname;
  74
  75             internal uint shi1_type;
  76             [MarshalAs( UnmanagedType.LPWStr )] internal string shi1_remark;
  77         }
  78
  79         #endregion
  80
  81         #region Constants
  82
  83         private const int MAX_PREFERRED_LENGTH = -1;
  84
  85         private const int SV_TYPE_WORKSTATION = 1;
  86         private const int SV_TYPE_SERVER = 2;
  87
  88         private const uint STYPE_DISKTREE = 0;
  89         private const uint STYPE_PRINTQ = 1;
  90         private const uint STYPE_DEVICE = 2;
  91         private const uint STYPE_IPC = 3;
  92
  93         private const uint STYPE_SPECIAL = 0x80000000;
  94         private const uint STYPE_TEMPORARY = 0x40000000;
  95
  96         #endregion
  97
  98         #region Public Methods
  99
 100         /// <summary>
 101         /// Get list of share names available on given server.
 102         /// </summary>
 103         /// <param name="serverName">Network machine name.</param>
 104         /// <returns>List of shares on server.</returns>
 105         public static IEnumerable<string> GetShares( string serverName )
 106         {
 107             IntPtr buffer = IntPtr.Zero;
 108             IntPtr tmpBuffer;
 109             int entriesRead;
 110             int totalEntries;
 111             int resHandle;
 112
 113             List<string> shares = new List<string>();
 114             int sizeofInfo = Marshal.SizeOf( typeof( _SHARE_INFO_1 ) );
 115
 116             try
 117             {
 118                 int ret = NetShareEnum( serverName, 1, ref buffer, MAX_PREFERRED_LENGTH, out entriesRead,
 119                                         out totalEntries,
 120                                         out resHandle );
 121
 122                 if ( ret == 0 )
 123                 {
 124                     for ( int i = 0; i < totalEntries; i++ )
 125                     {
 126                         // Get next pointer to share info structure
 127                         tmpBuffer = new IntPtr( (int) buffer + ( i * sizeofInfo ) );
 128
 129                         // Get structure from pointer
 130                         _SHARE_INFO_1 shareInfo =
 131                             (_SHARE_INFO_1) Marshal.PtrToStructure( tmpBuffer, typeof( _SHARE_INFO_1 ) );
 132
 133                         // Skipe special types of shares
 134                         if ( ( shareInfo.shi1_type & STYPE_TEMPORARY ) == STYPE_TEMPORARY
 135                              || ( shareInfo.shi1_type & STYPE_IPC ) == STYPE_IPC
 136                              || ( shareInfo.shi1_type & STYPE_DEVICE ) == STYPE_DEVICE
 137                              || ( shareInfo.shi1_type & STYPE_PRINTQ ) == STYPE_PRINTQ
 138                              || ( shareInfo.shi1_type & STYPE_SPECIAL ) == STYPE_SPECIAL
 139                              || shareInfo.shi1_remark == "Printer Drivers" )
 140                         {
 141                             continue;
 142                         }
 143
 144                         shares.Add( shareInfo.shi1_netname );
 145                     }
 146                 }
 147             }
 148             catch ( Exception ex )
 149             {
 150                 MessageBox.Show( "Problem with acessing " +
 151                                  "remote shares in NetworkBrowser " +
 152                                  "\r\n\r\n\r\n" + ex.Message,
 153                                  "Error", MessageBoxButtons.OK,
 154                                  MessageBoxIcon.Error );
 155                 return null;
 156             }
 157             finally
 158             {
 159                 // Free allocated memory
 160                 NetApiBufferFree( buffer );
 161             }
 162
 163             return shares;
 164         }
 165
 166         /// <summary>
 167         /// Get the list of network machine of types serves and workstation.
 168         /// </summary>
 169         /// <returns>List of machines in network.</returns>
 170         public static IEnumerable<string> GetNetworkComputers()
 171         {
 172             IntPtr buffer = IntPtr.Zero;
 173             IntPtr tmpBuffer;
 174             int entriesRead;
 175             int totalEntries;
 176             int resHandle;
 177             int sizeofInfo = Marshal.SizeOf( typeof( _SERVER_INFO_100 ) );
 178             string[] networkComputers = null;
 179             try
 180             {
 181                 // Get list of machines
 182                 int ret = NetServerEnum( null, 100, ref buffer,MAX_PREFERRED_LENGTH,out entriesRead,out totalEntries, SV_TYPE_WORKSTATION |SV_TYPE_SERVER, null, out resHandle );
 183
 184                 if ( ret == 0 )
 185                 {
 186                     networkComputers = new string[totalEntries];
 187                     for ( int i = 0; i < totalEntries; i++ )
 188                     {
 189                         // Get next pointer to server info structure
 190                         tmpBuffer = new IntPtr( (int) buffer +( i * sizeofInfo ) );
 191
 192                         // Get structure from pointer
 193                         _SERVER_INFO_100 svrInfo = (_SERVER_INFO_100)Marshal.PtrToStructure( tmpBuffer,typeof( _SERVER_INFO_100 ) );
 194
 195                         networkComputers[ i ] = svrInfo.sv100_name;
 196                     }
 197                 }
 198             }
 199             catch ( Exception ex )
 200             {
 201                 MessageBox.Show( "Problem with acessing " +
 202                                  "network computers in NetworkBrowser " +
 203                                  "\r\n\r\n\r\n" + ex.Message,
 204                                  "Error", MessageBoxButtons.OK,
 205                                  MessageBoxIcon.Error );
 206                 return null;
 207             }
 208             finally
 209             {
 210                 // Free allocated memory
 211                 NetApiBufferFree( buffer );
 212             }
 213
 214             return networkComputers;
 215         }
 216
 217         #endregion
 218     }
 219 }