WindowsXP/ds/security/passport/common/perflibrary/passportsharedmemory.cpp

#define _PassportExport_
#include "PassportExport.h"

#include "PassportSharedMemory.h"
#include <malloc.h>
#include <tchar.h>

#define PMUTEX_STRING _T("PASSPORTMUTEX")

//-------------------------------------------------------------
//
// PassportSharedMemory
//
//-------------------------------------------------------------
PassportSharedMemory::PassportSharedMemory()
{
	m_hShMem = 0;
	m_pbShMem = 0;
	m_bInited = 0;
	m_hMutex = 0;
	m_bUseMutex = FALSE;
}

//-------------------------------------------------------------
//
// ~PassportSharedMemory
//
//-------------------------------------------------------------
PassportSharedMemory::~PassportSharedMemory()
{
	CloseSharedMemory();
}


//-------------------------------------------------------------
//
// CreateSharedMemory
//
//-------------------------------------------------------------
BOOL PassportSharedMemory::CreateSharedMemory ( 
					const DWORD &dwMaximumSizeHigh, 
					const DWORD &dwMaximunSizeLow,
					LPCTSTR lpcName,
					BOOL	useMutex)
{

    BOOL fReturn  = FALSE;
	SID_IDENTIFIER_AUTHORITY siaWorld = SECURITY_WORLD_SID_AUTHORITY;

    // local param need to be freed before exit
	PSECURITY_DESCRIPTOR lpSD = NULL;
	SID *lpSID = NULL;
	LPSECURITY_ATTRIBUTES lpSA = NULL;

    // local param do not need to free
	TCHAR *pStr = NULL;

	if (!lpcName)
        goto exit;

	if (m_pbShMem != NULL && m_hShMem != NULL && m_bInited)
    {
        fReturn = TRUE;
        goto exit;
    }

	m_bUseMutex = useMutex;
	
	lpSD = malloc(1024);
	if (!lpSD)
        goto exit;

	if (!AllocateAndInitializeSid(	&siaWorld,				// Security, world authoity for ownership
									1,						// 1 relative sub-authority
									SECURITY_WORLD_RID,		// sub-authority, all users, world
									0, 0, 0, 0, 0, 0, 0,	// unused sub-authority types
									(void**)&lpSID))		// ** to security ID struct
	{
        goto exit;
	}

	InitializeSecurityDescriptor(lpSD, SECURITY_DESCRIPTOR_REVISION);

	SetSecurityDescriptorDacl(lpSD, TRUE, NULL, FALSE);		// allow access to DACL
	SetSecurityDescriptorGroup(lpSD, lpSID, FALSE);			// set owner group to lpSID
	SetSecurityDescriptorOwner(lpSD, NULL, FALSE);			// set owner to nobody
	SetSecurityDescriptorSacl(lpSD, FALSE, NULL, FALSE);	// disable system ACL access

	lpSA = new SECURITY_ATTRIBUTES;
    if( !lpSA )
        goto exit;

	lpSA->nLength = sizeof(SECURITY_ATTRIBUTES);
	lpSA->lpSecurityDescriptor = lpSD;
	lpSA->bInheritHandle = TRUE;

	m_hShMem = CreateFileMapping((INVALID_HANDLE_VALUE),                      
						lpSA,
						PAGE_READWRITE,                      
						dwMaximumSizeHigh,
						dwMaximunSizeLow,                      
						lpcName);
	
	if( !m_hShMem )
        goto exit;

	m_pbShMem = (BYTE*) MapViewOfFile( m_hShMem, 
		FILE_MAP_ALL_ACCESS, 
		0, 0, 0 );

	if( ! m_pbShMem )
		goto exit;

	if (useMutex)
	{
		pStr = (TCHAR *) _alloca ((_tcslen(lpcName) + _tcslen(PMUTEX_STRING) + 1) * sizeof(TCHAR));

		_tcscpy (pStr, lpcName);
		_tcscat (pStr, PMUTEX_STRING);
		m_hMutex = CreateMutex(lpSA,FALSE,pStr);
		
		if( !m_hMutex )
            goto exit;
	}
	
    // we are here because we are fully initialized :-)
	m_bInited = TRUE;
    fReturn = TRUE;

exit:
    // cleanup locally allocated heap
    if( lpSA ) 
        delete lpSA;

    if( lpSD )
		free(lpSD);

    if( lpSID )
        FreeSid(lpSID);

    // if we are not fully initialized, cleanup them
    if( !m_bInited )
	    CloseSharedMemory();

	return fReturn;
}	



//-------------------------------------------------------------
//
// OpenSharedMemory
//
//-------------------------------------------------------------
BOOL PassportSharedMemory::OpenSharedMemory( LPCTSTR lpcName, BOOL useMutex )
{
	
	if (!lpcName)
		return FALSE;

	if (m_pbShMem != NULL && m_hShMem != NULL && m_bInited)
		return TRUE;

	m_bUseMutex = useMutex;

	m_hShMem = OpenFileMapping( FILE_MAP_READ, FALSE, lpcName );
	if( ! m_hShMem )
	{
		return FALSE;
	}

	m_pbShMem = (BYTE*) MapViewOfFile( m_hShMem, FILE_MAP_READ, 0, 0, 0 );
	if( ! m_pbShMem )
	{
		CloseHandle( m_hShMem );
		m_hShMem = 0;
		return FALSE;
	}

	if (useMutex)
	{
		TCHAR *pStr = (TCHAR *) _alloca ((_tcslen(lpcName) + _tcslen(PMUTEX_STRING) + 1) * sizeof(TCHAR));
		_tcscpy (pStr, lpcName);
		_tcscat (pStr,PMUTEX_STRING);
		m_hMutex = OpenMutex(SYNCHRONIZE ,FALSE, pStr);
		if( !m_hMutex )
		{
			CloseSharedMemory();
			return FALSE;
		}
	}

	m_bInited = TRUE;
	return TRUE;
}

//-------------------------------------------------------------
//
// CloseSharedMemory
//
//-------------------------------------------------------------
void PassportSharedMemory::CloseSharedMemory( void )
{
	if( m_pbShMem )
	{
		UnmapViewOfFile( (void*) m_pbShMem );
		m_pbShMem = 0;
	}
	
	if( m_hShMem )
	{
		CloseHandle( m_hShMem );
		m_hShMem = 0;
	}

	if( m_hMutex )
	{
		ReleaseMutex(m_hMutex);
		m_hMutex = 0;;
	}
}