windows-nt/Source/XPSP1/NT/base/ntos/config/cmtree.c
2020-09-26 16:20:57 +08:00

410 lines
12 KiB
C

/*++
Copyright (c) 1991 Microsoft Corporation
Module Name:
cmtree.c
Abstract:
This module contains cm routines that understand the structure
of the registry tree.
Author:
Bryan M. Willman (bryanwi) 12-Sep-1991
Revision History:
--*/
#include "cmp.h"
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE,CmpGetValueListFromCache)
#pragma alloc_text(PAGE,CmpGetValueKeyFromCache)
#pragma alloc_text(PAGE,CmpFindValueByNameFromCache)
#endif
#ifndef _CM_LDR_
PCELL_DATA
CmpGetValueListFromCache(
IN PHHIVE Hive,
IN PCACHED_CHILD_LIST ChildList,
OUT BOOLEAN *IndexCached
)
/*++
Routine Description:
Get the Valve Index Array. Check if it is already cached, if not, cache it and return
the cached entry.
Arguments:
Hive - pointer to hive control structure for hive of interest
ChildList - pointer/index to the Value Index array
IndexCached - Indicating whether Value Index list is cached or not.
Return Value:
Pointer to the Valve Index Array.
NULL when we could not map view
--*/
{
PCELL_DATA List;
ULONG AllocSize;
PCM_CACHED_VALUE_INDEX CachedValueIndex;
ULONG i;
HCELL_INDEX CellToRelease;
#ifndef _WIN64
*IndexCached = TRUE;
if (CMP_IS_CELL_CACHED(ChildList->ValueList)) {
//
// The entry is already cached.
//
List = CMP_GET_CACHED_CELLDATA(ChildList->ValueList);
} else {
//
// The entry is not cached. The element contains the hive index.
//
CellToRelease = CMP_GET_CACHED_CELL_INDEX(ChildList->ValueList);
List = (PCELL_DATA) HvGetCell(Hive, CellToRelease);
if( List == NULL ) {
//
// we couldn't map a view for this cell
//
return NULL;
}
//
// Allocate a PagedPool to cache the value index cell.
//
AllocSize = ChildList->Count * sizeof(ULONG_PTR) + FIELD_OFFSET(CM_CACHED_VALUE_INDEX, Data);
// Dragos: Changed to catch the memory violator
// it didn't work
//CachedValueIndex = (PCM_CACHED_VALUE_INDEX) ExAllocatePoolWithTagPriority(PagedPool, AllocSize, CM_CACHE_VALUE_INDEX_TAG,NormalPoolPrioritySpecialPoolUnderrun);
CachedValueIndex = (PCM_CACHED_VALUE_INDEX) ExAllocatePoolWithTag(PagedPool, AllocSize, CM_CACHE_VALUE_INDEX_TAG);
if (CachedValueIndex) {
CachedValueIndex->CellIndex = CMP_GET_CACHED_CELL_INDEX(ChildList->ValueList);
for (i=0; i<ChildList->Count; i++) {
CachedValueIndex->Data.List[i] = (ULONG_PTR) List->u.KeyList[i];
}
ChildList->ValueList = CMP_MARK_CELL_CACHED(CachedValueIndex);
// Trying to catch the BAD guy who writes over our pool.
CmpMakeSpecialPoolReadOnly( CachedValueIndex );
//
// Now we have the stuff cached, use the cache data.
//
List = CMP_GET_CACHED_CELLDATA(ChildList->ValueList);
} else {
//
// If the allocation fails, just do not cache it. continue.
//
*IndexCached = FALSE;
}
HvReleaseCell(Hive, CellToRelease);
}
#else
CellToRelease = CMP_GET_CACHED_CELL_INDEX(ChildList->ValueList);
List = (PCELL_DATA) HvGetCell(Hive, CMP_GET_CACHED_CELL_INDEX(ChildList->ValueList));
*IndexCached = FALSE;
if( List == NULL ) {
//
// we couldn't map a view for this cell
// OBS: we can drop this as we return List anyway; just for clarity
//
return NULL;
}
HvReleaseCell(Hive, CellToRelease);
#endif
return (List);
}
PCM_KEY_VALUE
CmpGetValueKeyFromCache(
IN PHHIVE Hive,
IN PCELL_DATA List,
IN ULONG Index,
OUT PPCM_CACHED_VALUE *ContainingList,
IN BOOLEAN IndexCached,
OUT BOOLEAN *ValueCached,
OUT PHCELL_INDEX CellToRelease
)
/*++
Routine Description:
Get the Valve Node. Check if it is already cached, if not but the index is cached,
cache and return the value node.
Arguments:
Hive - pointer to hive control structure for hive of interest.
List - pointer to the Value Index Array (of ULONG_PTR if cached and ULONG if non-cached)
Index - Index in the Value index array
ContainlingList - The address of the entry that will receive the found cached value.
IndexCached - Indicate if the index list is cached. If not, everything is from the
original registry data.
ValueCached - Indicating whether Value is cached or not.
Return Value:
Pointer to the Value Node.
NULL when we couldn't map a view
--*/
{
PCM_KEY_VALUE pchild;
PULONG_PTR CachedList;
ULONG AllocSize;
ULONG CopySize;
PCM_CACHED_VALUE CachedValue;
*CellToRelease = HCELL_NIL;
if (IndexCached) {
//
// The index array is cached, so List is pointing to an array of ULONG_PTR.
// Use CachedList.
//
CachedList = (PULONG_PTR) List;
*ValueCached = TRUE;
if (CMP_IS_CELL_CACHED(CachedList[Index])) {
pchild = CMP_GET_CACHED_KEYVALUE(CachedList[Index]);
*ContainingList = &((PCM_CACHED_VALUE) CachedList[Index]);
} else {
pchild = (PCM_KEY_VALUE) HvGetCell(Hive, List->u.KeyList[Index]);
if( pchild == NULL ) {
//
// we couldn't map a view for this cell
// just return NULL; the caller must handle it gracefully
//
return NULL;
}
*CellToRelease = List->u.KeyList[Index];
//
// Allocate a PagedPool to cache the value node.
//
CopySize = (ULONG) HvGetCellSize(Hive, pchild);
AllocSize = CopySize + FIELD_OFFSET(CM_CACHED_VALUE, KeyValue);
// Dragos: Changed to catch the memory violator
// it didn't work
//CachedValue = (PCM_CACHED_VALUE) ExAllocatePoolWithTagPriority(PagedPool, AllocSize, CM_CACHE_VALUE_TAG,NormalPoolPrioritySpecialPoolUnderrun);
CachedValue = (PCM_CACHED_VALUE) ExAllocatePoolWithTag(PagedPool, AllocSize, CM_CACHE_VALUE_TAG);
if (CachedValue) {
//
// Set the information for later use if we need to cache data as well.
//
CachedValue->DataCacheType = CM_CACHE_DATA_NOT_CACHED;
CachedValue->ValueKeySize = (USHORT) CopySize;
RtlCopyMemory((PVOID)&(CachedValue->KeyValue), pchild, CopySize);
// Trying to catch the BAD guy who writes over our pool.
CmpMakeSpecialPoolReadWrite( CMP_GET_CACHED_ADDRESS(CachedList) );
CachedList[Index] = CMP_MARK_CELL_CACHED(CachedValue);
// Trying to catch the BAD guy who writes over our pool.
CmpMakeSpecialPoolReadOnly( CMP_GET_CACHED_ADDRESS(CachedList) );
// Trying to catch the BAD guy who writes over our pool.
CmpMakeSpecialPoolReadOnly(CachedValue);
*ContainingList = &((PCM_CACHED_VALUE) CachedList[Index]);
//
// Now we have the stuff cached, use the cache data.
//
pchild = CMP_GET_CACHED_KEYVALUE(CachedValue);
} else {
//
// If the allocation fails, just do not cache it. continue.
//
*ValueCached = FALSE;
}
}
} else {
//
// The Valve Index Array is from the registry hive, just get the cell and move on.
//
pchild = (PCM_KEY_VALUE) HvGetCell(Hive, List->u.KeyList[Index]);
*ValueCached = FALSE;
if( pchild == NULL ) {
//
// we couldn't map a view for this cell
// just return NULL; the caller must handle it gracefully
// OBS: we may remove this as we return pchild anyway; just for clarity
//
return NULL;
}
*CellToRelease = List->u.KeyList[Index];
}
return (pchild);
}
PCM_KEY_VALUE
CmpFindValueByNameFromCache(
IN PHHIVE Hive,
IN PCACHED_CHILD_LIST ChildList,
IN PUNICODE_STRING Name,
OUT PPCM_CACHED_VALUE *ContainingList,
OUT ULONG *Index,
OUT BOOLEAN *ValueCached,
OUT PHCELL_INDEX CellToRelease
)
/*++
Routine Description:
Find a value node given a value list array and a value name. It sequentially walk
through each value node to look for a match. If the array and
value nodes touched are not already cached, cache them.
Arguments:
Hive - pointer to hive control structure for hive of interest
ChildList - pointer/index to the Value Index array
Name - name of value to find
ContainlingList - The address of the entry that will receive the found cached value.
Index - pointer to variable to receive index for child
ValueCached - Indicate if the value node is cached.
Return Value:
HCELL_INDEX for the found cell
HCELL_NIL if not found
Notes:
New hives (Minor >= 4) have ValueList sorted; this implies ValueCache is sorted too;
So, we can do a binary search here!
--*/
{
NTSTATUS status;
PCM_KEY_VALUE pchild;
UNICODE_STRING Candidate;
LONG Result;
PCELL_DATA List;
BOOLEAN IndexCached;
ULONG Current;
*CellToRelease = HCELL_NIL;
if (ChildList->Count != 0) {
List = CmpGetValueListFromCache(Hive, ChildList, &IndexCached);
if( List == NULL ) {
//
// couldn't map view; bail out
//
return NULL;
}
//
// old plain hive; simulate a for
//
Current = 0;
while( TRUE ) {
if( *CellToRelease != HCELL_NIL ) {
HvReleaseCell(Hive,*CellToRelease);
*CellToRelease = HCELL_NIL;
}
pchild = CmpGetValueKeyFromCache(Hive, List, Current, ContainingList, IndexCached, ValueCached, CellToRelease);
if( pchild == NULL ) {
//
// couldn't map view; bail out
//
return NULL;
}
try {
//
// Name has user-mode buffer.
//
if (pchild->Flags & VALUE_COMP_NAME) {
Result = CmpCompareCompressedName( Name,
pchild->Name,
pchild->NameLength,
0);
} else {
Candidate.Length = pchild->NameLength;
Candidate.MaximumLength = Candidate.Length;
Candidate.Buffer = pchild->Name;
Result = RtlCompareUnicodeString( Name,
&Candidate,
TRUE);
}
} except (EXCEPTION_EXECUTE_HANDLER) {
CmKdPrintEx((DPFLTR_CONFIG_ID,CML_EXCEPTION,"CmpFindValueByNameFromCache: code:%08lx\n", GetExceptionCode()));
//
// the caller will bail out. Some ,alicious caller altered the Name buffer since we probed it.
//
return NULL;
}
if (Result == 0) {
//
// Success, fill the index, return data to caller and exit
//
*Index = Current;
return(pchild);
}
//
// compute the next index to try: old'n plain hive; go on
//
Current++;
if( Current == ChildList->Count ) {
//
// we've reached the end of the list; nicely return
//
return NULL;
}
} // while(TRUE)
}
//
// in the new design we shouldn't get here; we should exit the while loop with return
//
ASSERT( ChildList->Count == 0 );
return NULL;
}
#endif