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**Lance Edmonds** · 12 Aug 2001, 10:43 PM

LARGE_INTEGER is approximately equivalent to a QUAD-integer, and since PowerBASIC directly supports QUAD-integers it seems that using one is the best choice.

If you need to break the QUAD apart, then either use a UNION, the UDT you describe (and is now deemed redundant), or use pointers to access the two halves of the QUAD-integer.

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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Semen Matusovski** · 13 Aug 2001, 01:29 AM

> LARGE_INTEGER is approximately equivalent to a QUAD-integer

It's necessary to ask Microsoft to rewrite MSDN.

Code:

BOOL LookupPrivilegeValue(
  LPCTSTR lpSystemName,  // system name
  LPCTSTR lpName,        // privilege name
  PLUID lpLuid           // locally unique identifier
);

MSDN do not use "LARGE_INTEGER" (unlike this is the same).

If you change LUID to QUAD, why do you leave TYPE LUID ?
Where is a logic ?

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E-MAIL: [email protected]

**Lance Edmonds** · 13 Aug 2001, 02:11 AM

Possibly because a famous Russian programmer may still actually *want* to use a LUID structure for some reason... For the rest of us that just want to retrieve the parameter and possibly pass it to another API (without actually dealing with it's content), then a QUAD-integer is as suitable as any 8-byte block.

Basically, the WIN32API.INC file is not "set in stone" and compusory to use - you are free to modify and adapt it's equates, declarations and structures to suit your own purposes. If you don't like our translation, edit your copy!

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Cecil Williams** · 13 Aug 2001, 05:22 AM

The following is the C/C++ definition:

Code:

The LARGE_INTEGER structure is used to represent a 64-bit signed
integer value. 

typedef union _LARGE_INTEGER { 
    struct {
        DWORD LowPart; 
        LONG  HighPart; 
    };
    LONGLONG QuadPart;
} LARGE_INTEGER;

Members

LowPart
Specifies the low-order 32 bits.
HighPart
Specifies the high-order 32 bits.
QuadPart
Specifies a 64-bit signed integer.

Remarks
The LARGE_INTEGER structure is actually a union. If your compiler
has built-in support for 64-bit integers, use the QuadPart
member to store the 64-bit integer. Otherwise, use the LowPart
and HighPart members to store the 64-bit integer.

Lance's point is right on!!!!!!!

Also:

An LUID is a 64-bit value guaranteed to be unique only on the
system on which it was generated. The uniqueness of a locally
unique identifier (LUID) is guaranteed only until the system
is restarted.

An LUID is not for direct manipulation. Applications are to use
functions and structures to manipulate LUID values.

typedef LARGE_INTEGER LUID

The LUID is typedefed to a LARGE_INTEGER for convienence.

Cheers,
Cecil

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[This message has been edited by Cecil Williams (edited August 13, 2001).]

**Semen Matusovski** · 13 Aug 2001, 06:03 AM

Cecil & Lance --
Again, I don't doubt that Luid = QUAD.
But if to declare x As Quad, how to fill Privileges in TOKEN_PRIVILEGES ?
From current Win32Api:

Code:

TYPE LUID
  LowPart AS DWORD
  HighPart AS LONG
END TYPE

TYPE LUID_AND_ATTRIBUTES
  pLuid AS LUID
  Attributes AS DWORD
END TYPE

TYPE TOKEN_PRIVILEGES
  PrivilegeCount AS DWORD
  Privileges(0 TO 0) AS LUID_AND_ATTRIBUTES ' array size may vary
END TYPE

If to declare x As Luid, it's necessary to use ByVal VarPtr(x) in LookupPrivilegeValue.
For what purpose it was necessary to change Jule's declaration ?
It was incorrect ?

I know that I can edit Win32Api.Inc by myself. But it's not an argument -
new releases of Win32Api have new declarations and - de-facto - no choice.

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**Florent Heyworth** · 13 Aug 2001, 06:34 AM

Hi

personally I think one is better served by declaring TOKEN_PRIVILEGES
as follows:

Code:

TYPE T_TOKEN_PRIVILEGES
  PrivilegeCount AS DWORD
  Privileges AS BYTE PTR ' array size may vary
END TYPE
 
#IF NOT %DEF(%TOKEN_ADJUST_PRIVILEGES)
%TOKEN_ADJUST_PRIVILEGES = &H0020
#ENDIF
 
#IF NOT %DEF(%TOKEN_QUERY)
%TOKEN_QUERY = &H0008
#ENDIF
                      
'example usage
FUNCTION enableprivs() AS LONG
    LOCAL hToken AS LONG
    LOCAL tToken AS T_TOKEN_PRIVILEGES
    DIM tLuid(0:1) AS LUID_AND_ATTRIBUTES
     
    tToken.Privileges = VARPTR(tLuid(0))
 
    IF ISFALSE( OpenProcessToken( GetCurrentProcess(), _
                                    %TOKEN_ADJUST_PRIVILEGES OR %TOKEN_QUERY, _
                                    hToken ) )  THEN
        FUNCTION = %FALSE
        GOTO Clean_Up
    END IF
 
    ' enable SeBackupPrivilege, SeRestorePrivilege
    IF ISFALSE( LookUpPrivilegeValue( BYVAL %NULL, $SE_BACKUP_NAME, BYVAL VARPTR(tLuid(0)) ) ) THEN
        FUNCTION = %FALSE
        GOTO Clean_Up
    END IF
 
    IF ISFALSE( LookUpPrivilegeValue( BYVAL %NULL, $SE_RESTORE_NAME, BYVAL VARPTR(tLuid(1)) ) ) THEN
        FUNCTION = %FALSE
        GOTO Clean_Up
    END IF
 
    tToken.PrivilegeCount = 2
    tLuid(0).Attributes = %SE_PRIVILEGE_ENABLED
    tLuid(1).Attributes = %SE_PRIVILEGE_ENABLED
 
    FUNCTION = AdjustTokenPrivileges( hToken, %FALSE, BYVAL VARPTR(tToken), 4 + (LEN(LUID_AND_ATTRIBUTES) * 2), _
                                        BYVAL %NULL, BYVAL %NULL )
     
Clean_Up:
    CALL CloseHandle( hToken )
 
END FUNCTION

since it is more convenient when setting multiple privileges..

Cheers

Florent

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**Tom Hanlin** · 13 Aug 2001, 10:33 AM

Microsoft invented LARGE_INTEGER because they didn't have a QUAD type. In most cases,
it's more useful to use QUAD if you have it, so we replaced LARGE_INTEGER with QUAD
in the Win32API update of 11 July 2001. This affected a few functions such as
LookupPrivilegeValue, which apparently had lpLuid defined as LARGE_INTEGER instead of
as LUID. For consistency, the LUID type will be used with LUIDs in the future.

Florent, it's not safe to define Priveleges AS BYTE PTR -- that's an actual array,
not a pointer. TOKEN_PRIVILEGES is one of Microsoft's "fake types", intended as
documentation rather than to be used in a program. You need to define your own
version of TOKEN_PRIVILEGES with the appropriate array size, or just allocate a
generic block of memory and map it in some convenient fashion.

------------------
Tom Hanlin
PowerBASIC Staff

**Florent Heyworth** · 13 Aug 2001, 10:38 AM

Tom

if you look at the code the byte ptr points to a separate
ARRAY of LUID_AND_ATTRIBUTES which is correctly dimensioned.
In which way is this unsafe?

Cheers

Florent

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**Tom Hanlin** · 13 Aug 2001, 11:14 AM

Windows is expecting the actual array element(s), not a pointer to them.
Or have I overlooked something?

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Tom Hanlin
PowerBASIC Staff

**Florent Heyworth** · 13 Aug 2001, 11:26 AM

[UPDATE added later]
Hi Tom

Oops - I ended up talking about TOKEN_PRIVILEGES whereas
the conversation is about LUID_AND_ATTRIBUTES. You are
correct in saying that Windows expects an array of
LUID_AND_ATTRIBUTES - however it seems windows *casts*
the memory to an internal structure which is why it works.

This may be a case of better safe than sorry - implementations
may change
[/UPDATE]

Hi Tom

Windows is expecting a pointer to TOKEN_PRIVILEGES (it's
declared as PTOKEN_PRIVILEGES) according to the MSDN
documentation of AdjustTokenPrivileges.

Quoting from MSDN:

NewState
Pointer to a TOKEN_PRIVILEGES structure that specifies
an array of privileges and their attributes

Declaring Privileges as a pointer or a DWORD would allow us to set it
to the required size without us having to edit Win32api.inc. Of course
not a big deal either way although adapting our own win32api.inc
may mean that some code we post may not be compatible with others^
versions...

Cheers

Florent

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[This message has been edited by Florent Heyworth (edited August 13, 2001).]

Announcement

Win32api.inc quirk - LookupPrivilegeValue and large_integer type

Win32api.inc quirk - LookupPrivilegeValue and large_integer type

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