windows-nt/Source/XPSP1/NT/ds/netapi/netlib/midluser.c
2020-09-26 16:20:57 +08:00

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/*++
Copyright (c) 1991-1992 Microsoft Corporation
Module Name:
MidlUser.c
Abstract:
This file contains common functions and utilities that the API
DLLs can use in making remote calls. This includes the
MIDL_USER_ALLOCATE functions.
The following routines are called by MIDL-generated code and the
NetApiBufferAllocate and NetApiBufferFree routines:
MIDL_user_allocate
MIDL_user_free
The following routines are NOT called by MIDL-generated code; they are
only called by the NetApiBufferReallocate and NetApiBufferSize routines:
MIDL_user_reallocate
MIDL_user_size
Author:
Dan Lafferty danl 06-Feb-1991
Environment:
User Mode - Win32
Revision History:
06-Feb-1991 danl
Created
25-Apr-1991 JohnRo
Split out MIDL user (allocate,free) into seperate source file, so
linker doesn't get confused.
03-Dec-1991 JohnRo
Added MIDL_user_reallocate and MIDL_user_size APIs. (These are so we
create the NetApiBufferAllocate, NetApiBufferReallocate, and
NetApiBufferSize APIs.)
Also check alignment of allocated data.
12-Jan-1992 JohnRo
Workaround a LocalReAlloc() bug where 2nd or 3rd realloc messes up.
(See WIN32_WORKAROUND code below.)
08-Jun-1992 JohnRo
RAID 9258: return non-null pointer when allocating zero bytes.
Also, SteveWo finally fixed LocalReAlloc() bug, so use it again.
Avoid calling LocalFree() with null pointer, to avoid access viol.
01-Dec-1992 JohnRo
Fix MIDL_user_ func signatures.
Avoid compiler warnings (const vs. volatile).
--*/
// These must be included first:
#include <windef.h> // win32 typedefs
#include <rpc.h> // rpc prototypes
// These may be included in any order:
#include <align.h> // POINTER_IS_ALIGNED(), ALIGN_WORST.
#include <rpcutil.h> // My prototypes.
#include <netdebug.h> // NetpAssert().
#include <stdarg.h> // memcpy().
#include <winbase.h> // LocalAlloc(), LMEM_ flags, etc.
#define LOCAL_ALLOCATION_FLAGS LMEM_FIXED
void __RPC_FAR * __RPC_API
MIDL_user_allocate(
IN size_t NumBytes
)
/*++
Routine Description:
Allocates storage for RPC transactions. The RPC stubs will either call
MIDL_user_allocate when it needs to un-marshall data into a buffer
that the user must free. RPC servers will use MIDL_user_allocate to
allocate storage that the RPC server stub will free after marshalling
the data.
Arguments:
NumBytes - The number of bytes to allocate. (Note that NetApiBufferAllocate
depends on being able to request that zero bytes be allocated and get
back a non-null pointer.)
Return Value:
Pointer to the allocated memory.
--*/
{
LPVOID NewPointer;
NewPointer = (LPVOID) LocalAlloc(
LOCAL_ALLOCATION_FLAGS,
NumBytes);
NetpAssert( POINTER_IS_ALIGNED( NewPointer, ALIGN_WORST) );
return (NewPointer);
} // MIDL_user_allocate
void __RPC_API
MIDL_user_free(
IN void __RPC_FAR *MemPointer
)
/*++
Routine Description:
Frees storage used in RPC transactions. The RPC client can call this
function to free buffer space that was allocated by the RPC client
stub when un-marshalling data that is to be returned to the client.
The Client calls MIDL_user_free when it is finished with the data and
desires to free up the storage.
The RPC server stub calls MIDL_user_free when it has completed
marshalling server data that is to be passed back to the client.
Arguments:
MemPointer - This points to the memory block that is to be released.
Return Value:
none.
--*/
{
NetpAssert( POINTER_IS_ALIGNED( MemPointer, ALIGN_WORST) );
if (MemPointer != NULL) {
(void) LocalFree(MemPointer);
}
} // MIDL_user_free
void *
MIDL_user_reallocate(
IN void * OldPointer OPTIONAL,
IN size_t NewByteCount
)
{
LPVOID NewPointer; // may be NULL.
NetpAssert( POINTER_IS_ALIGNED( OldPointer, ALIGN_WORST) );
// Special cases: something into nothing, or nothing into something.
if (OldPointer == NULL) {
NewPointer = (LPVOID) LocalAlloc(
LOCAL_ALLOCATION_FLAGS,
NewByteCount);
} else if (NewByteCount == 0) {
(void) LocalFree( OldPointer );
NewPointer = NULL;
} else { // must be realloc of something to something else.
HANDLE hOldMem;
HANDLE hNewMem; // handle for new (may = old handle)
hOldMem = LocalHandle( (LPSTR) OldPointer);
NetpAssert(hOldMem != NULL);
hNewMem = LocalReAlloc(
hOldMem, // old handle
NewByteCount, // new size in bytes
LOCAL_ALLOCATION_FLAGS | // flags
LMEM_MOVEABLE); // (motion okay)
if (hNewMem == NULL) {
return (NULL);
}
NewPointer = (LPVOID) hNewMem;
}
NetpAssert( POINTER_IS_ALIGNED( NewPointer, ALIGN_WORST) );
return (NewPointer);
} // MIDL_user_reallocate
unsigned long
MIDL_user_size(
IN void * Pointer
)
{
DWORD ByteCount;
HANDLE hMemory;
NetpAssert( Pointer != NULL );
NetpAssert( POINTER_IS_ALIGNED( Pointer, ALIGN_WORST ) );
hMemory = LocalHandle( (LPSTR) Pointer );
NetpAssert( hMemory != NULL );
ByteCount = (DWORD)LocalSize( hMemory );
NetpAssert( ByteCount > 0 );
return (ByteCount);
} // MIDL_user_size