VOID
CmpDereferenceNameControlBlockWithLock(
PCM_NAME_CONTROL_BLOCK Ncb
)
{
PCM_NAME_HASH *Prev;
PCM_NAME_HASH Current;
if (--Ncb->RefCount == 0) {
//
// Remove it from the the Hash Table
//
Prev = &(GET_HASH_ENTRY(CmpNameCacheTable, Ncb->ConvKey));
while (TRUE) {
Current = *Prev;
ASSERT(Current != NULL);
if (Current == &(Ncb->NameHash)) {
*Prev = Current->NextHash;
break;
}
Prev = &Current->NextHash;
}
//
// Free storage
//
ExFreePoolWithTag(Ncb, CM_NAME_TAG | PROTECTED_POOL);
}
return;
}
VOID
NTAPI
CmpRemoveKeyHash(IN PCM_KEY_HASH KeyHash)
{
PCM_KEY_HASH *Prev;
PCM_KEY_HASH Current;
ASSERT_VALID_HASH(KeyHash);
/* Lookup all the keys in this index entry */
Prev = &GET_HASH_ENTRY(CmpCacheTable, KeyHash->ConvKey).Entry;
while (TRUE)
{
/* Save the current one and make sure it's valid */
Current = *Prev;
ASSERT(Current != NULL);
ASSERT_VALID_HASH(Current);
/* Check if it matches */
if (Current == KeyHash)
{
/* Then write the previous one */
*Prev = Current->NextHash;
if (*Prev) ASSERT_VALID_HASH(*Prev);
break;
}
/* Otherwise, keep going */
Prev = &Current->NextHash;
}
}
VOID
NTAPI
CmpDereferenceNameControlBlockWithLock(IN PCM_NAME_CONTROL_BLOCK Ncb)
{
PCM_NAME_HASH Current, *Next;
ULONG ConvKey = Ncb->ConvKey;
/* Lock the NCB */
CmpAcquireNcbLockExclusiveByKey(ConvKey);
/* Decrease the reference count */
ASSERT(Ncb->RefCount >= 1);
if (!(--Ncb->RefCount))
{
/* Find the NCB in the table */
Next = &GET_HASH_ENTRY(CmpNameCacheTable, Ncb->ConvKey).Entry;
while (TRUE)
{
/* Check the current entry */
Current = *Next;
ASSERT(Current != NULL);
if (Current == &Ncb->NameHash)
{
/* Unlink it */
*Next = Current->NextHash;
break;
}
/* Get to the next one */
Next = &Current->NextHash;
}
/* Found it, now free it */
CmpFree(Ncb, 0);
}
/* Release the lock */
CmpReleaseNcbLockByKey(ConvKey);
}
PCM_NAME_CONTROL_BLOCK
NTAPI
CmpGetNameControlBlock(IN PUNICODE_STRING NodeName)
{
PCM_NAME_CONTROL_BLOCK Ncb = NULL;
ULONG ConvKey = 0;
PWCHAR p, pp;
ULONG i;
BOOLEAN IsCompressed = TRUE, Found = FALSE;
PCM_NAME_HASH HashEntry;
ULONG Length, NcbSize;
/* Loop the name */
p = NodeName->Buffer;
for (i = 0; i < NodeName->Length; i += sizeof(WCHAR))
{
/* Make sure it's not a slash */
if (*p != OBJ_NAME_PATH_SEPARATOR)
{
/* Add it to the hash */
ConvKey = 37 * ConvKey + RtlUpcaseUnicodeChar(*p);
}
/* Next character */
p++;
}
/* Set assumed lengh and loop to check */
Length = NodeName->Length / sizeof(WCHAR);
for (i = 0; i < (NodeName->Length / sizeof(WCHAR)); i++)
{
/* Check if this is a 16-bit character */
if (NodeName->Buffer[i] > (UCHAR)-1)
{
/* This is the actual size, and we know we're not compressed */
Length = NodeName->Length;
IsCompressed = FALSE;
break;
}
}
/* Lock the NCB entry */
CmpAcquireNcbLockExclusiveByKey(ConvKey);
/* Get the hash entry */
HashEntry = GET_HASH_ENTRY(CmpNameCacheTable, ConvKey).Entry;
while (HashEntry)
{
/* Get the current NCB */
Ncb = CONTAINING_RECORD(HashEntry, CM_NAME_CONTROL_BLOCK, NameHash);
/* Check if the hash matches */
if ((ConvKey == HashEntry->ConvKey) && (Length == Ncb->NameLength))
{
/* Assume success */
Found = TRUE;
/* If the NCB is compressed, do a compressed name compare */
if (Ncb->Compressed)
{
/* Compare names */
if (CmpCompareCompressedName(NodeName, Ncb->Name, Length))
{
/* We failed */
Found = FALSE;
}
}
else
{
/* Do a manual compare */
p = NodeName->Buffer;
pp = Ncb->Name;
for (i = 0; i < Ncb->NameLength; i += sizeof(WCHAR))
{
/* Compare the character */
if (RtlUpcaseUnicodeChar(*p) != RtlUpcaseUnicodeChar(*pp))
{
/* Failed */
Found = FALSE;
break;
}
/* Next chars */
p++;
pp++;
}
}
/* Check if we found a name */
if (Found)
{
/* Reference it */
ASSERT(Ncb->RefCount != 0xFFFF);
Ncb->RefCount++;
break;
}
}
/* Go to the next hash */
HashEntry = HashEntry->NextHash;
}
/* Check if we didn't find it */
if (!Found)
{
/* Allocate one */
NcbSize = FIELD_OFFSET(CM_NAME_CONTROL_BLOCK, Name) + Length;
Ncb = CmpAllocate(NcbSize, TRUE, TAG_CM);
if (!Ncb)
{
/* Release the lock and fail */
CmpReleaseNcbLockByKey(ConvKey);
return NULL;
}
/* Clear it out */
RtlZeroMemory(Ncb, NcbSize);
/* Check if the name was compressed */
if (IsCompressed)
{
/* Copy the compressed name */
for (i = 0; i < NodeName->Length / sizeof(WCHAR); i++)
{
/* Copy Unicode to ANSI */
((PCHAR)Ncb->Name)[i] = (CHAR)RtlUpcaseUnicodeChar(NodeName->Buffer[i]);
}
}
else
{
/* Copy the name directly */
for (i = 0; i < NodeName->Length / sizeof(WCHAR); i++)
{
/* Copy each unicode character */
Ncb->Name[i] = RtlUpcaseUnicodeChar(NodeName->Buffer[i]);
}
}
/* Setup the rest of the NCB */
Ncb->Compressed = IsCompressed;
Ncb->ConvKey = ConvKey;
Ncb->RefCount++;
Ncb->NameLength = Length;
/* Insert the name in the hash table */
HashEntry = &Ncb->NameHash;
HashEntry->NextHash = GET_HASH_ENTRY(CmpNameCacheTable, ConvKey).Entry;
GET_HASH_ENTRY(CmpNameCacheTable, ConvKey).Entry = HashEntry;
}
/* Release NCB lock */
CmpReleaseNcbLockByKey(ConvKey);
/* Return the NCB found */
return Ncb;
}
