PIPEEX.C

/******************************************************************************\ 
*       This is a part of the Microsoft Source Code Samples.  
*       Copyright 1995 - 1997 Microsoft Corporation. 
*       All rights reserved.  
*       This source code is only intended as a supplement to  
*       Microsoft Development Tools and/or WinHelp documentation. 
*       See these sources for detailed information regarding the  
*       Microsoft samples programs. 
\******************************************************************************/ 
 
/*++ 
 
Copyright (c) 1997  Microsoft Corporation 
 
Module Name: 
 
    pipeex.c 
 
Abstract: 
 
    CreatePipe-like function that lets one or both handles be overlapped 
 
Author: 
 
    Dave Hart  Summer 1997 
 
Revision History: 
 
--*/ 
 
#include <windows.h> 
#include <stdio.h> 
 
ULONG PipeSerialNumber; 
 
BOOL 
APIENTRY 
MyCreatePipeEx( 
    OUT LPHANDLE lpReadPipe, 
    OUT LPHANDLE lpWritePipe, 
    IN LPSECURITY_ATTRIBUTES lpPipeAttributes, 
    IN DWORD nSize, 
    DWORD dwReadMode, 
    DWORD dwWriteMode 
    ) 
 
/*++ 
 
Routine Description: 
 
    The CreatePipeEx API is used to create an anonymous pipe I/O device. 
    Unlike CreatePipe FILE_FLAG_OVERLAPPED may be specified for one or 
    both handles. 
    Two handles to the device are created.  One handle is opened for 
    reading and the other is opened for writing.  These handles may be 
    used in subsequent calls to ReadFile and WriteFile to transmit data 
    through the pipe. 
 
Arguments: 
 
    lpReadPipe - Returns a handle to the read side of the pipe.  Data 
        may be read from the pipe by specifying this handle value in a 
        subsequent call to ReadFile. 
 
    lpWritePipe - Returns a handle to the write side of the pipe.  Data 
        may be written to the pipe by specifying this handle value in a 
        subsequent call to WriteFile. 
 
    lpPipeAttributes - An optional parameter that may be used to specify 
        the attributes of the new pipe.  If the parameter is not 
        specified, then the pipe is created without a security 
        descriptor, and the resulting handles are not inherited on 
        process creation.  Otherwise, the optional security attributes 
        are used on the pipe, and the inherit handles flag effects both 
        pipe handles. 
 
    nSize - Supplies the requested buffer size for the pipe.  This is 
        only a suggestion and is used by the operating system to 
        calculate an appropriate buffering mechanism.  A value of zero 
        indicates that the system is to choose the default buffering 
        scheme. 
 
Return Value: 
 
    TRUE - The operation was successful. 
 
    FALSE/NULL - The operation failed. Extended error status is available 
        using GetLastError. 
 
--*/ 
 
{ 
    HANDLE ReadPipeHandle, WritePipeHandle; 
    DWORD dwError; 
    UCHAR PipeNameBuffer[ MAX_PATH ]; 
 
    // 
    // Only one valid OpenMode flag - FILE_FLAG_OVERLAPPED 
    // 
 
    if ((dwReadMode | dwWriteMode) & (~FILE_FLAG_OVERLAPPED)) { 
        SetLastError(ERROR_INVALID_PARAMETER); 
        return FALSE; 
    } 
 
    // 
    //  Set the default timeout to 120 seconds 
    // 
 
    if (nSize == 0) { 
        nSize = 4096; 
        } 
 
    sprintf( PipeNameBuffer, 
             "\\\\.\\Pipe\\RemoteExeAnon.%08x.%08x", 
             GetCurrentProcessId(), 
             PipeSerialNumber++ 
           ); 
 
    ReadPipeHandle = CreateNamedPipeA( 
                         PipeNameBuffer, 
                         PIPE_ACCESS_INBOUND | dwReadMode, 
                         PIPE_TYPE_BYTE | PIPE_WAIT, 
                         1,             // Number of pipes 
                         nSize,         // Out buffer size 
                         nSize,         // In buffer size 
                         120 * 1000,    // Timeout in ms 
                         lpPipeAttributes 
                         ); 
 
    if (! ReadPipeHandle) { 
        return FALSE; 
    } 
 
    WritePipeHandle = CreateFileA( 
                        PipeNameBuffer, 
                        GENERIC_WRITE, 
                        0,                         // No sharing 
                        lpPipeAttributes, 
                        OPEN_EXISTING, 
                        FILE_ATTRIBUTE_NORMAL | dwWriteMode, 
                        NULL                       // Template file 
                      ); 
 
    if (INVALID_HANDLE_VALUE == WritePipeHandle) { 
        dwError = GetLastError(); 
        CloseHandle( ReadPipeHandle ); 
        SetLastError(dwError); 
        return FALSE; 
    } 
 
    *lpReadPipe = ReadPipeHandle; 
    *lpWritePipe = WritePipeHandle; 
    return( TRUE ); 
}