C # - NetUseAdd from NetApi32.dll on Windows Server 2008 and IIS7

Question

I am trying to use NetUseAdd to add the share necessary for the application. My code is as follows.

[DllImport("NetApi32.dll", SetLastError = true, CharSet = CharSet.Unicode)] internal static extern uint NetUseAdd( string UncServerName, uint Level, IntPtr Buf, out uint ParmError); 

...

 USE_INFO_2 info = new USE_INFO_2(); info.ui2_local = null; info.ui2_asg_type = 0xFFFFFFFF; info.ui2_remote = remoteUNC; info.ui2_username = username; info.ui2_password = Marshal.StringToHGlobalAuto(password); info.ui2_domainname = domainName; IntPtr buf = Marshal.AllocHGlobal(Marshal.SizeOf(info)); try { Marshal.StructureToPtr(info, buf, true); uint paramErrorIndex; uint returnCode = NetUseAdd(null, 2, buf, out paramErrorIndex); if (returnCode != 0) { throw new Win32Exception((int)returnCode); } } finally { Marshal.FreeHGlobal(buf); } 

This works fine on our 2003 servers. But trying to upgrade to Server 2008 and IIS7, it no longer works. Thanks to liberal logging, I found that it hangs on the Marshal.StructureToPtr(info, buf, true); line Marshal.StructureToPtr(info, buf, true);

I have absolutely no idea why this could anyone shed light on him to tell me where I can find additional information?

Answer 1

The reason is this:

You pulled the p / invoke signature from pinvoke.net and you did not confirm it. The fool who originally wrote this p / invoke code example had no idea what he was doing, and created one that "works" on 32-bit systems but does not work on 64-bit systems. He somehow turned a very simple p / invoke signature into some kind of surprisingly complicated mess, and it spread like wildfire on the net.

Correct Signature:

  [DllImport( "NetApi32.dll", SetLastError = true, CharSet = CharSet.Unicode )] public static extern uint NetUseAdd( string UncServerName, UInt32 Level, ref USE_INFO_2 Buf, out UInt32 ParmError ); [StructLayout( LayoutKind.Sequential, CharSet = CharSet.Unicode )] public struct USE_INFO_2 { public string ui2_local; public string ui2_remote; public string ui2_password; public UInt32 ui2_status; public UInt32 ui2_asg_type; public UInt32 ui2_refcount; public UInt32 ui2_usecount; public string ui2_username; public string ui2_domainname; } 

And your code should read:

 USE_INFO_2 info = new USE_INFO_2(); info.ui2_local = null; info.ui2_asg_type = 0xFFFFFFFF; info.ui2_remote = remoteUNC; info.ui2_username = username; info.ui2_password = password; info.ui2_domainname = domainName; uint paramErrorIndex; uint returnCode = NetUseAdd(null, 2, ref info, out paramErrorIndex); if (returnCode != 0) { throw new Win32Exception((int)returnCode); } 

Hope this helps. I just spent half a day on the knee of deep remote debugging of someone elses trash code, trying to figure out what was going on, and that was it.

Answer 2

What is your structure for your structure? I believe USE_INFO_2 should be [StructLayout (LayoutKind.Sequential, CharSet = CharSet.Unicode)].

Also, have you tried just passing the structure by reference, and not to Marshal.StructureToPtr?

Answer 3

Good job! All that I could not see in my Windows browser. A few days later, ShellNotification came to my mind. This I previously used to associate file icons. And, as I recall, there was a trigger for adding NetShare. Yes, right!

In addition to NetShareAdd, you must run SHChangeNotify from shell32.dll.

 ShellNotification.NotifyCreateDrive(info.ui2_local); 

And this is the class I used for it:

 public class ShellNotification { [DllImport("shell32.dll")] private static extern void SHChangeNotify( UInt32 wEventId, UInt32 uFlags, IntPtr dwItem1, IntPtr dwItem2); // Notify shell of change of file associations. public static void NotifyOfChange() { SHChangeNotify( (uint)ShellChangeNotificationEvents.SHCNE_ASSOCCHANGED, (uint)(ShellChangeNotificationFlags.SHCNF_IDLIST | ShellChangeNotificationFlags.SHCNF_FLUSHNOWAIT), IntPtr.Zero, IntPtr.Zero); } internal static void NotifyCreateDrive(string path) //path = "M:" { IntPtr strPtr = Marshal.StringToHGlobalUni(path); //A folder on the local computer is being shared via the network. SHCNF_IDLIST or SHCNF_PATHW must be specified in uFlags. dwItem1 contains the folder that is being shared. dwItem2 is not used and should be NULL. SHChangeNotify( (uint)ShellChangeNotificationEvents.SHCNE_NETSHARE, (uint)(ShellChangeNotificationFlags.SHCNF_IDLIST | ShellChangeNotificationFlags.SHCNF_PATHW), strPtr, IntPtr.Zero); //also, you need to make sure to free the unmanaged memory: Marshal.FreeHGlobal(strPtr); } [Flags] private enum ShellChangeNotificationEvents : uint { //The name of a nonfolder item has changed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the previous PIDL or name of the item. dwItem2 contains the new PIDL or name of the item. SHCNE_RENAMEITEM = 0x00000001, //A nonfolder item has been created. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the item that was created. dwItem2 is not used and should be NULL. SHCNE_CREATE = 0x00000002, //A nonfolder item has been deleted. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the item that was deleted. dwItem2 is not used and should be NULL. SHCNE_DELETE = 0x00000004, //A folder has been created. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the folder that was created. dwItem2 is not used and should be NULL. SHCNE_MKDIR = 0x00000008, //A folder has been removed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the folder that was removed. dwItem2 is not used and should be NULL. SHCNE_RMDIR = 0x00000010, //Storage media has been inserted into a drive. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive that contains the new media. dwItem2 is not used and should be NULL. SHCNE_MEDIAINSERTED = 0x00000020, //Storage media has been removed from a drive. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive from which the media was removed. dwItem2 is not used and should be NULL. SHCNE_MEDIAREMOVED = 0x00000040, //A drive has been removed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive that was removed. dwItem2 is not used and should be NULL. SHCNE_DRIVEREMOVED = 0x00000080, //A drive has been added. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive that was added. dwItem2 is not used and should be NULL. SHCNE_DRIVEADD = 0x00000100, //A folder on the local computer is being shared via the network. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the folder that is being shared. dwItem2 is not used and should be NULL. SHCNE_NETSHARE = 0x00000200, //A folder on the local computer is no longer being shared via the network. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the folder that is no longer being shared. dwItem2 is not used and should be NULL. SHCNE_NETUNSHARE = 0x00000400, //The attributes of an item or folder have changed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the item or folder that has changed. dwItem2 is not used and should be NULL. SHCNE_ATTRIBUTES = 0x00000800, //The contents of an existing folder have changed, but the folder still exists and has not been renamed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the folder that has changed. dwItem2 is not used and should be NULL. If a folder has been created, deleted, or renamed, use SHCNE_MKDIR, SHCNE_RMDIR, or SHCNE_RENAMEFOLDER, respectively, instead. SHCNE_UPDATEDIR = 0x00001000, //An existing nonfolder item has changed, but the item still exists and has not been renamed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the item that has changed. dwItem2 is not used and should be NULL. If a nonfolder item has been created, deleted, or renamed, use SHCNE_CREATE, SHCNE_DELETE, or SHCNE_RENAMEITEM, respectively, instead. SHCNE_UPDATEITEM = 0x00002000, //The computer has disconnected from a server. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the server from which the computer was disconnected. dwItem2 is not used and should be NULL. SHCNE_SERVERDISCONNECT = 0x00004000, //An image in the system image list has changed. SHCNF_DWORD must be specified in uFlags. dwItem1 contains the index in the system image list that has changed. dwItem2 is not used and should be NULL. SHCNE_UPDATEIMAGE = 0x00008000, //A drive has been added and the Shell should create a new window for the drive. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive that was added. dwItem2 is not used and should be NULL. SHCNE_DRIVEADDGUI = 0x00010000, //The name of a folder has changed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the previous pointer to an item identifier list (PIDL) or name of the folder. dwItem2 contains the new PIDL or name of the folder. SHCNE_RENAMEFOLDER = 0x00020000, //The amount of free space on a drive has changed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive on which the free space changed. dwItem2 is not used and should be NULL. SHCNE_FREESPACE = 0x00040000, //Not currently used. SHCNE_EXTENDED_EVENT = 0x04000000, //A file type association has changed. SHCNF_IDLIST must be specified in the uFlags parameter. dwItem1 and dwItem2 are not used and must be NULL. SHCNE_ASSOCCHANGED = 0x08000000, //Specifies a combination of all of the disk event identifiers. SHCNE_DISKEVENTS = 0x0002381F, //Specifies a combination of all of the global event identifiers. SHCNE_GLOBALEVENTS = 0x0C0581E0, //All events have occurred. SHCNE_ALLEVENTS = 0x7FFFFFFF, //The specified event occurred as a result of a system interrupt. As this value modifies other event values, it cannot be used alone. SHCNE_INTERRUPT = 0x80000000 } private enum ShellChangeNotificationFlags { //dwItem1 and dwItem2 are the addresses of ITEMIDLIST structures that represent the item(s) affected by the change. Each ITEMIDLIST must be relative to the desktop folder. SHCNF_IDLIST = 0x0000, //dwItem1 and dwItem2 are the addresses of null-terminated strings of maximum length MAX_PATH that contain the full path names of the items affected by the change. SHCNF_PATHA = 0x0001, //dwItem1 and dwItem2 are the addresses of null-terminated strings that represent the friendly names of the printer(s) affected by the change. SHCNF_PRINTERA = 0x0002, //The dwItem1 and dwItem2 parameters are DWORD values. SHCNF_DWORD = 0x0003, //like SHCNF_PATHA but unicode string SHCNF_PATHW = 0x0005, //like SHCNF_PRINTERA but unicode string SHCNF_PRINTERW = 0x0006, //? SHCNF_TYPE = 0x00FF, //The function should not return until the notification has been delivered to all affected components. As this flag modifies other data-type flags, it cannot by used by itself. SHCNF_FLUSH = 0x1000, //The function should begin delivering notifications to all affected components but should return as soon as the notification process has begun. As this flag modifies other data-type flags, it cannot by used by itself. } } 

I hope others will give a welcome addition.