/***********************************************************************
 * 
 *  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.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 NamedPipeNative {
		#region Comments
		/// <summary>
		/// Outbound pipe access.
		/// </summary>
		#endregion
		public const uint PIPE_ACCESS_OUTBOUND = 0x00000002;
		#region Comments
		/// <summary>
		/// Duplex pipe access.
		/// </summary>
		#endregion
		public const uint PIPE_ACCESS_DUPLEX = 0x00000003;
		#region Comments
		/// <summary>
		/// Inbound pipe access.
		/// </summary>
		#endregion
		public const uint PIPE_ACCESS_INBOUND = 0x00000001;
		#region Comments
		/// <summary>
		/// Pipe blocking mode.
		/// </summary>
		#endregion
		public const uint PIPE_WAIT = 0x00000000;
		#region Comments
		/// <summary>
		/// Pipe non-blocking mode.
		/// </summary>
		#endregion
		public const uint PIPE_NOWAIT = 0x00000001;
		#region Comments
		/// <summary>
		/// Pipe read mode of type Byte.
		/// </summary>
		#endregion
		public const uint PIPE_READMODE_BYTE = 0x00000000;
		#region Comments
		/// <summary>
		/// Pipe read mode of type Message.
		/// </summary>
		#endregion
		public const uint PIPE_READMODE_MESSAGE = 0x00000002;
		#region Comments
		/// <summary>
		/// Byte pipe type.
		/// </summary>
		#endregion
		public const uint PIPE_TYPE_BYTE = 0x00000000;
		#region Comments
		/// <summary>
		/// Message pipe type.
		/// </summary>
		#endregion
		public const uint PIPE_TYPE_MESSAGE = 0x00000004;
		#region Comments
		/// <summary>
		/// Pipe client end.
		/// </summary>
		#endregion
		public const uint PIPE_CLIENT_END = 0x00000000;
		#region Comments
		/// <summary>
		/// Pipe server end.
		/// </summary>
		#endregion
		public const uint PIPE_SERVER_END = 0x00000001;
		#region Comments
		/// <summary>
		/// Unlimited server pipe instances.
		/// </summary>
		#endregion
		public const uint PIPE_UNLIMITED_INSTANCES = 255;
		#region Comments
		/// <summary>
		/// Waits indefinitely when connecting to a pipe.
		/// </summary>
		#endregion
		public const uint NMPWAIT_WAIT_FOREVER = 0xffffffff;
		#region Comments
		/// <summary>
		/// Does not wait for the named pipe.
		/// </summary>
		#endregion
		public const uint NMPWAIT_NOWAIT = 0x00000001;
		#region Comments
		/// <summary>
		/// Uses the default time-out specified in a call to the CreateNamedPipe method.
		/// </summary>
		#endregion
		public const uint NMPWAIT_USE_DEFAULT_WAIT = 0x00000000;
		#region Comments
		/// <summary>
		/// 
		/// </summary>
		#endregion
		public const uint GENERIC_READ = (0x80000000);
		#region Comments
		/// <summary>
		/// Generic write access to the pipe.
		/// </summary>
		#endregion
		public const uint GENERIC_WRITE = (0x40000000);
		#region Comments
		/// <summary>
		/// Generic execute access to the pipe.
		/// </summary>
		#endregion
		public const uint GENERIC_EXECUTE = (0x20000000);
		#region Comments
		/// <summary>
		/// Read, write, and execute access.
		/// </summary>
		#endregion
		public const uint GENERIC_ALL = (0x10000000);
		#region Comments
		/// <summary>
		/// Create new file. Fails if the file exists.
		/// </summary>
		#endregion
		public const uint CREATE_NEW        = 1;
		#region Comments
		/// <summary>
		/// Create new file. Overrides an existing file.
		/// </summary>
		#endregion
		public const uint CREATE_ALWAYS     = 2;
		#region Comments
		/// <summary>
		/// Open existing file.
		/// </summary>
		#endregion
		public const uint OPEN_EXISTING     = 3;
		#region Comments
		/// <summary>
		/// Open existing file. If the file does not exist, creates it.
		/// </summary>
		#endregion
		public const uint OPEN_ALWAYS       = 4;
		#region Comments
		/// <summary>
		/// Opens the file and truncates it so that its size is zero bytes.
		/// </summary>
		#endregion
		public const uint TRUNCATE_EXISTING = 5;
		#region Comments
		/// <summary>
		/// Invalid operating system handle.
		/// </summary>
		#endregion
		public const int INVALID_HANDLE_VALUE = -1;
		#region Comments
		/// <summary>
		/// The operation completed successfully.
		/// </summary>
		#endregion
		public const ulong ERROR_SUCCESS = 0;
		#region Comments
		/// <summary>
		/// The system cannot find the file specified.
		/// </summary>
		#endregion
		public const ulong ERROR_CANNOT_CONNECT_TO_PIPE = 2;
		#region Comments
		/// <summary>
		/// All pipe instances are busy.
		/// </summary>
		#endregion
		public const ulong ERROR_PIPE_BUSY = 231;
		#region Comments
		/// <summary>
		/// The pipe is being closed.
		/// </summary>
		#endregion
		public const ulong ERROR_NO_DATA = 232;
		#region Comments
		/// <summary>
		/// No process is on the other end of the pipe.
		/// </summary>
		#endregion
		public const ulong ERROR_PIPE_NOT_CONNECTED = 233;
		#region Comments
		/// <summary>
		/// More data is available.
		/// </summary>
		#endregion
		public const ulong ERROR_MORE_DATA = 234;
		#region Comments
		/// <summary>
		/// There is a process on other end of the pipe.
		/// </summary>
		#endregion
		public const ulong ERROR_PIPE_CONNECTED = 535;
		#region Comments
		/// <summary>
		/// Waiting for a process to open the other end of the pipe.
		/// </summary>
		#endregion
		public const ulong ERROR_PIPE_LISTENING = 536;
		#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.SECURITY_ATTRIBUTES">SECURITY_ATTRIBUTES</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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		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", SetLastError=true)]
		public static extern bool CloseHandle(
			IntPtr hHandle);
		#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 NamedPipeNative() {}
	}
	#region Comments
	/// <summary>
	/// Security Descriptor structure
	/// </summary>
	#endregion
	[StructLayout(LayoutKind.Sequential)]
	public struct SECURITY_DESCRIPTOR {
		private byte Revision;
		private byte Sbz1;
		private ushort Control;
		private IntPtr Owner;
		private IntPtr Group;
		private IntPtr Sacl;
		private IntPtr Dacl;
	}
	#region Comments
	/// <summary>
	/// Security Attributes structure.
	/// </summary>
	#endregion
	[StructLayout(LayoutKind.Sequential)]
	public struct SECURITY_ATTRIBUTES {
		public int nLength;
		public IntPtr lpSecurityDescriptor;
		public bool bInheritHandle;
	}
	#region Comments
	/// <summary>
	/// This class is used as a dummy parameter only.
	/// </summary>
	#endregion
	[StructLayout(LayoutKind.Sequential)]
	public class Overlapped {
	}
	#region Comments
	/// <summary>
	/// This class is used as a dummy parameter only.
	/// </summary>
	#endregion
	[StructLayout(LayoutKind.Sequential)]
	public class SecurityAttributes {
	}
}