/***********************************************************************
 * 
 *  Copyright (C) 2005-2006 Novell, Inc. All Rights Reserved.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; version 2.1
 *  of the License.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, Novell, Inc.
 * 
 *  To contact Novell about this file by physical or electronic mail, 
 *  you may find current contact information at www.novell.com.
 * 
 ***********************************************************************/


using System;
using System.Text;
using System.Security;
using System.Runtime.InteropServices;

namespace AppModule.NamedPipes {
	#region Comments
	/// <summary>
	/// This utility class exposes kernel32.dll methods for named pipes communication.
	/// </summary>
	/// <remarks>
	/// Use the following links for complete information about the exposed methods:
	/// <list type="bullet">
	/// <item>
	/// <description><a href="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ipc/base/pipe_functions.asp" target="_blank">Named Pipe Functions</a></description>
	/// </item>
	/// <item>
	/// <description><a href="http://msdn.microsoft.com/library/en-us/fileio/base/file_management_functions.asp" target="_blank">File Management Functions</a></description>
	/// </item>
	/// <item>
	/// <description><a href="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/sysinfo/base/handle_and_object_functions.asp" target="_blank">Handle and Object Functions</a></description>
	/// </item>
	/// <item>
	/// <description><a href="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/debug/base/system_error_codes.asp" target="_blank">System Error Codes</a></description>
	/// </item>
	/// </list>
	/// </remarks>
	#endregion
	[SuppressUnmanagedCodeSecurity]
	public sealed class ImpersonateNative 
	{
		#region Comments
		/// <summary>
		/// 
		/// </summary>
		#endregion
		public const int TOKEN_QUERY = 0X00000008;
		
		public enum TOKEN_INFORMATION_CLASS
		{
			TokenUser = 1,
			TokenGroups,
			TokenPrivileges,
			TokenOwner,
			TokenPrimaryGroup,
			TokenDefaultDacl,
			TokenSource,
			TokenType,
			TokenImpersonationLevel,
			TokenStatistics,
			TokenRestrictedSids,
			TokenSessionId
		}

		[StructLayout(LayoutKind.Sequential)]
			public struct TOKEN_USER
		{
			public _SID_AND_ATTRIBUTES User;
		}

		[StructLayout(LayoutKind.Sequential)]
			public struct _SID_AND_ATTRIBUTES
		{
			public IntPtr Sid;
			public int Attributes;
		}

		[StructLayout(LayoutKind.Sequential)]
			public struct _LUID 
		{ 
			public int LowPart ; 
			public int HighPart; 
		} //LUID, *PLUID; 


		[StructLayout(LayoutKind.Sequential)]
			public struct TOKEN_STATISTICS 
		{ 
			public _LUID TokenId; 
			public _LUID AuthenticationId; 
			public int ExpirationTime; 
			public int TokenType;			// enum ini in 1 TOKEN_TYPE 
			public int ImpersonationLevel;	//SECURITY_IMPERSONATION_LEVEL ImpersonationLevel; 
			public int DynamicCharged;		////DWORD 
			public int DynamicAvailable;	//DWORD 
			public int GroupCount;			//DWORD 
			public int PrivilegeCount;		//DWORD 
			public _LUID ModifiedId; 
		}// TOKEN_STATISTICS, *PTOKEN_STATISTICS; 


		#region Comments
		/// <summary>
		/// Creates an instance of a named pipe and returns a handle for 
		/// subsequent pipe operations.
		/// </summary>
		/// <param name="lpName">Pointer to the null-terminated string that 
		/// uniquely identifies the pipe.</param>
		/// <param name="dwOpenMode">Pipe access mode, the overlapped mode, 
		/// the write-through mode, and the security access mode of the pipe handle.</param>
		/// <param name="dwPipeMode">Type, read, and wait modes of the pipe handle.</param>
		/// <param name="nMaxInstances">Maximum number of instances that can be 
		/// created for this pipe.</param>
		/// <param name="nOutBufferSize">Number of bytes to reserve for the output buffer.</param>
		/// <param name="nInBufferSize">Number of bytes to reserve for the input buffer.</param>
		/// <param name="nDefaultTimeOut">Default time-out value, in milliseconds.</param>
		/// <param name="pipeSecurityDescriptor">Pointer to a 
		/// <see cref="AppModule.NamedPipes.SecurityAttributes">SecurityAttributes</see> 
		/// object that specifies a security descriptor for the new named pipe.</param>
		/// <returns>If the function succeeds, the return value is a handle 
		/// to the server end of a named pipe instance.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern IntPtr CreateNamedPipe(
			String lpName,									// pipe name
			uint dwOpenMode,								// pipe open mode
			uint dwPipeMode,								// pipe-specific modes
			uint nMaxInstances,							// maximum number of instances
			uint nOutBufferSize,						// output buffer size
			uint nInBufferSize,							// input buffer size
			uint nDefaultTimeOut,						// time-out interval
			IntPtr pipeSecurityDescriptor		// SD
			);
		#region Comments
		/// <summary>
		/// Enables a named pipe server process to wait for a client 
		/// process to connect to an instance of a named pipe.
		/// </summary>
		/// <param name="hHandle">Handle to the server end of a named pipe instance.</param>
		/// <param name="lpOverlapped">Pointer to an 
		/// <see cref="AppModule.NamedPipes.Overlapped">Overlapped</see> object.</param>
		/// <returns>If the function succeeds, the return value is nonzero.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool ConnectNamedPipe(
			IntPtr hHandle,									// handle to named pipe
			Overlapped lpOverlapped					// overlapped structure
			);
		#region Comments
		/// <summary>
		/// Connects to a message-type pipe (and waits if an instance of the 
		/// pipe is not available), writes to and reads from the pipe, and then closes the pipe.
		/// </summary>
		/// <param name="lpNamedPipeName">Pointer to a null-terminated string 
		/// specifying the pipe name.</param>
		/// <param name="lpInBuffer">Pointer to the buffer containing the data written 
		/// to the pipe.</param>
		/// <param name="nInBufferSize">Size of the write buffer, in bytes.</param>
		/// <param name="lpOutBuffer">Pointer to the buffer that receives the data 
		/// read from the pipe.</param>
		/// <param name="nOutBufferSize">Size of the read buffer, in bytes.</param>
		/// <param name="lpBytesRead">Pointer to a variable that receives the number 
		/// of bytes read from the pipe.</param>
		/// <param name="nTimeOut">Number of milliseconds to wait for the 
		/// named pipe to be available.</param>
		/// <returns>If the function succeeds, the return value is nonzero.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool CallNamedPipe(
			string lpNamedPipeName,
			byte[] lpInBuffer,
			uint nInBufferSize,
			byte[] lpOutBuffer,
			uint nOutBufferSize,
			byte[] lpBytesRead,
			int nTimeOut
			);
		#region Comments
		/// <summary>
		/// Creates or opens a file, directory, physical disk, volume, console buffer, 
		/// tape drive, communications resource, mailslot, or named pipe.
		/// </summary>
		/// <param name="lpFileName">Pointer to a null-terminated string that 
		/// specifies the name of the object to create or open.</param>
		/// <param name="dwDesiredAccess">Access to the object (reading, writing, or both).</param>
		/// <param name="dwShareMode">Sharing mode of the object (reading, writing, both, or neither).</param>
		/// <param name="attr">Pointer to a 
		/// <see cref="AppModule.NamedPipes.SecurityAttributes">SecurityAttributes</see> 
		/// object that determines whether the returned handle can be inherited 
		/// by child processes.</param>
		/// <param name="dwCreationDisposition">Action to take on files that exist, 
		/// and which action to take when files do not exist.</param>
		/// <param name="dwFlagsAndAttributes">File attributes and flags.</param>
		/// <param name="hTemplateFile">Handle to a template file, with the GENERIC_READ access right.</param>
		/// <returns>If the function succeeds, the return value is an open handle to the specified file.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern IntPtr CreateFile(
			String lpFileName,						  // file name
			uint dwDesiredAccess,					  // access mode
			uint dwShareMode,								// share mode
			SecurityAttributes attr,				// SD
			uint dwCreationDisposition,			// how to create
			uint dwFlagsAndAttributes,			// file attributes
			uint hTemplateFile);					  // handle to template file
		#region Comments
		/// <summary>
		/// Reads data from a file, starting at the position indicated by the file pointer.
		/// </summary>
		/// <param name="hHandle">Handle to the file to be read.</param>
		/// <param name="lpBuffer">Pointer to the buffer that receives the data read from the file.</param>
		/// <param name="nNumberOfBytesToRead">Number of bytes to be read from the file.</param>
		/// <param name="lpNumberOfBytesRead">Pointer to the variable that receives the number of bytes read.</param>
		/// <param name="lpOverlapped">Pointer to an 
		/// <see cref="AppModule.NamedPipes.Overlapped">Overlapped</see> object.</param>
		/// <returns>The ReadFile function returns when one of the following 
		/// conditions is met: a write operation completes on the write end of 
		/// the pipe, the number of bytes requested has been read, or an error occurs.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool ReadFile(
			IntPtr hHandle,											// handle to file
			byte[] lpBuffer,								// data buffer
			uint nNumberOfBytesToRead,			// number of bytes to read
			byte[] lpNumberOfBytesRead,			// number of bytes read
			uint lpOverlapped								// overlapped buffer
			);
		#region Comments
		/// <summary>
		/// Writes data to a file at the position specified by the file pointer.
		/// </summary>
		/// <param name="hHandle">Handle to the file.</param>
		/// <param name="lpBuffer">Pointer to the buffer containing the data to be written to the file.</param>
		/// <param name="nNumberOfBytesToWrite"></param>
		/// <param name="lpNumberOfBytesWritten">Pointer to the variable that receives the number of bytes written.</param>
		/// <param name="lpOverlapped">Pointer to an 
		/// <see cref="AppModule.NamedPipes.Overlapped">Overlapped</see> object.</param>
		/// <returns>If the function succeeds, the return value is nonzero.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool WriteFile(
			IntPtr hHandle,											// handle to file
			byte[] lpBuffer,							  // data buffer
			uint nNumberOfBytesToWrite,			// number of bytes to write
			byte[] lpNumberOfBytesWritten,	// number of bytes written
			uint lpOverlapped								// overlapped buffer
			);
		#region Comments
		/// <summary>
		/// Retrieves information about a specified named pipe.
		/// </summary>
		/// <param name="hHandle">Handle to the named pipe for which information is wanted.</param>
		/// <param name="lpState">Pointer to a variable that indicates the current 
		/// state of the handle.</param>
		/// <param name="lpCurInstances">Pointer to a variable that receives the 
		/// number of current pipe instances.</param>
		/// <param name="lpMaxCollectionCount">Pointer to a variable that receives 
		/// the maximum number of bytes to be collected on the client's computer 
		/// before transmission to the server.</param>
		/// <param name="lpCollectDataTimeout">Pointer to a variable that receives 
		/// the maximum time, in milliseconds, that can pass before a remote named 
		/// pipe transfers information over the network.</param>
		/// <param name="lpUserName">Pointer to a buffer that receives the 
		/// null-terminated string containing the user name string associated 
		/// with the client application. </param>
		/// <param name="nMaxUserNameSize">Size of the buffer specified by the 
		/// lpUserName parameter.</param>
		/// <returns>If the function succeeds, the return value is nonzero.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool GetNamedPipeHandleState(
			IntPtr hHandle,
			IntPtr lpState,
			ref uint lpCurInstances,
			IntPtr lpMaxCollectionCount,
			IntPtr lpCollectDataTimeout,
			IntPtr lpUserName,
			IntPtr nMaxUserNameSize
			);
		#region Comments
		/// <summary>
		/// Cancels all pending input and output (I/O) operations that were 
		/// issued by the calling thread for the specified file handle.
		/// </summary>
		/// <param name="hHandle">Handle to a file.</param>
		/// <returns>If the function succeeds, the return value is nonzero.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool CancelIo(
			IntPtr hHandle
			);
		#region Comments
		/// <summary>
		/// Waits until either a time-out interval elapses or an instance 
		/// of the specified named pipe is available for connection.
		/// </summary>
		/// <param name="name">Pointer to a null-terminated string that specifies 
		/// the name of the named pipe.</param>
		/// <param name="timeout">Number of milliseconds that the function will 
		/// wait for an instance of the named pipe to be available.</param>
		/// <returns>If an instance of the pipe is available before the 
		/// time-out interval elapses, the return value is nonzero.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool WaitNamedPipe(
			String name,
			int timeout);
		#region Comments
		/// <summary>
		/// Retrieves the calling thread's last-error code value.
		/// </summary>
		/// <returns>The return value is the calling thread's last-error code value.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern uint GetLastError();
		#region Comments
		/// <summary>
		/// Flushes the buffers of the specified file and causes all buffered data to be written to the file.
		/// </summary>
		/// <param name="hHandle">Handle to an open file.</param>
		/// <returns>If the function succeeds, the return value is nonzero.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool FlushFileBuffers(
			IntPtr hHandle);
		#region Comments
		/// <summary>
		/// Disconnects the server end of a named pipe instance from a client process.
		/// </summary>
		/// <param name="hHandle">Handle to an instance of a named pipe.</param>
		/// <returns>If the function succeeds, the return value is nonzero.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool DisconnectNamedPipe(
			IntPtr hHandle);
		#region Comments
		/// <summary>
		/// Sets the read mode and the blocking mode of the specified named pipe.
		/// </summary>
		/// <remarks>
		/// If the specified handle is to the client end of a named pipe and if 
		/// the named pipe server process is on a remote computer, the function 
		/// can also be used to control local buffering.
		/// </remarks>
		/// <param name="hHandle">Handle to the named pipe instance.</param>
		/// <param name="mode">Pointer to a variable that supplies the new mode.</param>
		/// <param name="cc">Pointer to a variable that specifies the maximum 
		/// number of bytes collected on the client computer before 
		/// transmission to the server.</param>
		/// <param name="cd">Pointer to a variable that specifies the 
		/// maximum time, in milliseconds, that can pass before a remote 
		/// named pipe transfers information over the network.</param>
		/// <returns>If the function succeeds, the return value is nonzero.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool SetNamedPipeHandleState(
			IntPtr hHandle,
			ref uint mode,
			IntPtr cc,
			IntPtr cd);
		#region Comments
		/// <summary>
		/// Closes an open object handle.
		/// </summary>
		/// <param name="hHandle">Handle to an open object.</param>
		/// <returns>If the function succeeds, the return value is nonzero.</returns>
		#endregion
		[DllImport("kernel32.dll")]
		public static extern bool CloseHandle(
			IntPtr hHandle);

		[DllImport("kernel32.dll")]
		public static extern IntPtr GetCurrentThread();

		// native for named pipes
		#region Comments
		/// <summary>
		/// Closes an open object handle.
		/// </summary>
		/// <param name="hHandle">Handle to an open object.</param>
		/// <returns>If the function succeeds, the return value is nonzero.</returns>
		#endregion
		[DllImport("advapi32" )]
		public static extern int ImpersonateNamedPipeClient(
			IntPtr hHandle);

		[DllImport("advapi32" )]
		public static extern bool RevertToSelf();

		[DllImport("advapi32",  SetLastError=true)]
		public static extern bool OpenThreadToken(
			IntPtr hThread,
			uint desiredInfo,
			bool openAsSelf,
			out IntPtr TokenHandle); // handle to open access token 

		[DllImport("advapi32")]
		public static extern bool OpenProcessToken(
			IntPtr ProcessHandle, // handle to process
			int DesiredAccess, // desired access to process
			ref IntPtr TokenHandle // handle to open access token
			);

		[DllImport("advapi32", CharSet=CharSet.Auto)]
		public static extern bool GetTokenInformation(
			IntPtr hToken,
			TOKEN_INFORMATION_CLASS tokenInfoClass,
			IntPtr TokenInformation,
			int tokeInfoLength,
			ref int reqLength);


		[DllImport("advapi32", CharSet=CharSet.Auto)]
		public static extern bool LookupAccountSid
			(
			[In,MarshalAs(UnmanagedType.LPTStr)] string lpSystemName, // name of local or remote computer
			IntPtr pSid, // security identifier
			StringBuilder Account, // account name buffer
			ref int cbName, // size of account name buffer
			StringBuilder DomainName, // domain name
			ref int cbDomainName, // size of domain name buffer
			ref int peUse // SID type
			// ref _SID_NAME_USE peUse // SID type
			);

		[DllImport("advapi32", CharSet=CharSet.Auto)]
		public static extern bool ConvertSidToStringSid(
			IntPtr pSID,
			[In,Out,MarshalAs(UnmanagedType.LPTStr)] ref string pStringSid);
	
		#region Comments
		/// <summary>
		/// Sets the security descriptor attributes
		/// </summary>
		/// <param name="sd">Reference to a SECURITY_DESCRIPTOR structure.</param>
		/// <param name="bDaclPresent"></param>
		/// <param name="Dacl"></param>
		/// <param name="bDaclDefaulted"></param>
		/// <returns></returns>
		#endregion
		[DllImport("Advapi32.dll", SetLastError=true)]
		public static extern bool SetSecurityDescriptorDacl(ref SECURITY_DESCRIPTOR sd, bool bDaclPresent, IntPtr Dacl, bool bDaclDefaulted);
		#region Comments
		/// <summary>
		/// Initializes a SECURITY_DESCRIPTOR structure.
		/// </summary>
		/// <param name="sd"></param>
		/// <param name="dwRevision"></param>
		/// <returns></returns>
		#endregion
		[DllImport("Advapi32.dll", SetLastError=true)]
		public static extern bool InitializeSecurityDescriptor(out SECURITY_DESCRIPTOR sd, int dwRevision);
		#region Comments
		/// <summary>
		/// Private constructor.
		/// </summary>
		#endregion
		private ImpersonateNative() {}
	}
}