517 lines
16 KiB
C
517 lines
16 KiB
C
|
//+-------------------------------------------------------------------------
|
||
|
//
|
||
|
// Microsoft Windows
|
||
|
// Copyright (C) Microsoft Corporation, 1992 - 1992.
|
||
|
//
|
||
|
// File: prefix.c
|
||
|
//
|
||
|
// Contents: PREFIX table implementation
|
||
|
//
|
||
|
// History: SethuR -- Implemented
|
||
|
//
|
||
|
// Notes:
|
||
|
//
|
||
|
//--------------------------------------------------------------------------
|
||
|
|
||
|
#ifdef KERNEL_MODE
|
||
|
#include "dfsprocs.h"
|
||
|
|
||
|
#define Dbg DEBUG_TRACE_RTL
|
||
|
|
||
|
#else
|
||
|
|
||
|
#define DfsDbgTrace(x,y,z,a)
|
||
|
|
||
|
#endif
|
||
|
|
||
|
#include <prefix.h>
|
||
|
#include <prefixp.h>
|
||
|
|
||
|
PDFS_PREFIX_TABLE_ENTRY
|
||
|
DfspNextUnicodeTableEntry(
|
||
|
IN PDFS_PREFIX_TABLE_ENTRY pEntry);
|
||
|
|
||
|
#ifdef ALLOC_PRAGMA
|
||
|
|
||
|
#pragma alloc_text( PAGE, DfsInitializePrefixTable )
|
||
|
#pragma alloc_text( PAGE, DfsInsertInPrefixTable )
|
||
|
#pragma alloc_text( PAGE, DfsLookupPrefixTable )
|
||
|
#pragma alloc_text( PAGE, DfsFindUnicodePrefix )
|
||
|
#pragma alloc_text( PAGE, DfsRemoveFromPrefixTable )
|
||
|
|
||
|
#endif // ALLOC_PRAGMA
|
||
|
|
||
|
//+---------------------------------------------------------------------------
|
||
|
//
|
||
|
// Function: DfsInitializePrefixTable
|
||
|
//
|
||
|
// Synopsis: API for initializing the prefix table
|
||
|
//
|
||
|
// Arguments: [pTable] -- the DFS prefix table instance
|
||
|
//
|
||
|
// Returns: one of the following NTSTATUS codes
|
||
|
// STATUS_SUCCESS -- call was successfull.
|
||
|
//
|
||
|
// History: 04-18-94 SethuR Created
|
||
|
//
|
||
|
// Notes:
|
||
|
//
|
||
|
//----------------------------------------------------------------------------
|
||
|
|
||
|
NTSTATUS DfsInitializePrefixTable(PDFS_PREFIX_TABLE pTable, BOOLEAN fCaseSensitive)
|
||
|
{
|
||
|
NTSTATUS status = STATUS_SUCCESS;
|
||
|
|
||
|
DfsDbgTrace(+1, Dbg,"DfsInitializePrefixTable -- Entry\n", 0);
|
||
|
|
||
|
if (pTable != NULL)
|
||
|
{
|
||
|
ULONG i;
|
||
|
|
||
|
// Initialize flags
|
||
|
pTable->CaseSensitive = fCaseSensitive;
|
||
|
|
||
|
// Initialize the root entry
|
||
|
INITIALIZE_PREFIX_TABLE_ENTRY(&pTable->RootEntry);
|
||
|
|
||
|
// Initialize the various buckets.
|
||
|
for (i = 0;i < NO_OF_HASH_BUCKETS;i++)
|
||
|
{
|
||
|
INITIALIZE_BUCKET(pTable->Buckets[i]);
|
||
|
}
|
||
|
|
||
|
// Initialize the name page list.
|
||
|
pTable->NamePageList.pFirstPage = ALLOCATE_NAME_PAGE();
|
||
|
if (pTable->NamePageList.pFirstPage != NULL)
|
||
|
{
|
||
|
INITIALIZE_NAME_PAGE(pTable->NamePageList.pFirstPage);
|
||
|
|
||
|
// Initialize the prefix table entry allocation mechanism.
|
||
|
status = _InitializePrefixTableEntryAllocation(pTable);
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
status = STATUS_NO_MEMORY;
|
||
|
DfsDbgTrace(0, Dbg,"DfsInitializePrefixTable Error -- %lx\n",status);
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
status = STATUS_INVALID_PARAMETER;
|
||
|
DfsDbgTrace(0, Dbg,"DfsInitializePrefixTable Error -- %lx\n",status);
|
||
|
}
|
||
|
|
||
|
DfsDbgTrace(-1, Dbg, "DfsInitializePrefixTable -- Exit\n", 0);
|
||
|
return status;
|
||
|
}
|
||
|
|
||
|
//+---------------------------------------------------------------------------
|
||
|
//
|
||
|
// Function: DfsInsertInPrefixTable
|
||
|
//
|
||
|
// Synopsis: API for inserting a path in the prefix table
|
||
|
//
|
||
|
// Arguments: [pTable] -- the DFS prefix table instance
|
||
|
//
|
||
|
// [pPath] -- the path to be looked up.
|
||
|
//
|
||
|
// [pData] -- BLOB associated with the path
|
||
|
//
|
||
|
// Returns: one of the following NTSTATUS codes
|
||
|
// STATUS_SUCCESS -- call was successfull.
|
||
|
//
|
||
|
// History: 04-18-94 SethuR Created
|
||
|
//
|
||
|
// Notes:
|
||
|
//
|
||
|
//----------------------------------------------------------------------------
|
||
|
|
||
|
NTSTATUS DfsInsertInPrefixTable(PDFS_PREFIX_TABLE pTable,
|
||
|
PUNICODE_STRING pPath,
|
||
|
PVOID pData)
|
||
|
{
|
||
|
NTSTATUS status = STATUS_SUCCESS;
|
||
|
WCHAR Buffer[MAX_PATH_SEGMENT_SIZE];
|
||
|
PWCHAR NameBuffer = Buffer;
|
||
|
USHORT cbNameBuffer = sizeof(Buffer);
|
||
|
UNICODE_STRING Path,Name;
|
||
|
ULONG BucketNo;
|
||
|
PDFS_PREFIX_TABLE_ENTRY pEntry = NULL;
|
||
|
PDFS_PREFIX_TABLE_ENTRY pParentEntry = NULL;
|
||
|
BOOLEAN fNameFound = FALSE;
|
||
|
|
||
|
DfsDbgTrace(+1, Dbg, "DfsInsertInPrefixTable -- Entry\n", 0);
|
||
|
|
||
|
// There is one special case, i.e., in which the prefix is '\'.
|
||
|
// Since this is the PATH_DELIMITER which is treated in a special
|
||
|
// way, we do the processing upfront.
|
||
|
|
||
|
if (pPath->Length == 0)
|
||
|
{
|
||
|
return STATUS_SUCCESS;
|
||
|
}
|
||
|
else if ((pPath->Length == sizeof(WCHAR)) &&
|
||
|
(pPath->Buffer[0] == PATH_DELIMITER))
|
||
|
{
|
||
|
pTable->RootEntry.pData = pData;
|
||
|
return STATUS_SUCCESS;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
Path.Length = pPath->Length - sizeof(WCHAR);
|
||
|
Path.MaximumLength = pPath->MaximumLength;
|
||
|
Path.Buffer = &pPath->Buffer[1];
|
||
|
pParentEntry = &pTable->RootEntry;
|
||
|
}
|
||
|
|
||
|
if (Path.Length > MAX_PATH_SEGMENT_SIZE * sizeof(WCHAR) ) {
|
||
|
NameBuffer = ExAllocatePool( NonPagedPool, Path.Length + sizeof(WCHAR) );
|
||
|
if (NameBuffer == NULL) {
|
||
|
DfsDbgTrace(0, Dbg, "Unable to allocate %d non-paged bytes\n", (Path.Length + sizeof(WCHAR)) );
|
||
|
return( STATUS_INSUFFICIENT_RESOURCES );
|
||
|
} else {
|
||
|
cbNameBuffer = Path.Length + sizeof(WCHAR);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
while (Path.Length > 0)
|
||
|
{
|
||
|
Name.Length = 0;
|
||
|
Name.Buffer = NameBuffer;
|
||
|
Name.MaximumLength = cbNameBuffer;
|
||
|
|
||
|
// Process the name segment
|
||
|
if (pTable->CaseSensitive)
|
||
|
{
|
||
|
SPLIT_CASE_SENSITIVE_PATH(&Path,&Name,BucketNo);
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
SPLIT_CASE_INSENSITIVE_PATH(&Path,&Name,BucketNo);
|
||
|
}
|
||
|
|
||
|
if (Name.Length > 0)
|
||
|
{
|
||
|
// Lookup the table to see if the name segment already exists.
|
||
|
DfsDbgTrace(0, Dbg, "LOOKUP_BUCKET: Bucket(%ld)\n", BucketNo);
|
||
|
DfsDbgTrace(0, Dbg, " for Name(%wZ)\n", &Name);
|
||
|
|
||
|
LOOKUP_BUCKET(pTable->Buckets[BucketNo],Name,pParentEntry,pEntry,fNameFound);
|
||
|
|
||
|
DfsDbgTrace(0, Dbg, "returned pEntry(%lx)", pEntry);
|
||
|
DfsDbgTrace(0, Dbg, " fNameFound(%s)\n", fNameFound ? "TRUE" : "FALSE");
|
||
|
|
||
|
if (pEntry == NULL)
|
||
|
{
|
||
|
// Initialize the new entry and initialize the name segment.
|
||
|
pEntry = ALLOCATE_DFS_PREFIX_TABLE_ENTRY(pTable);
|
||
|
if (pEntry != NULL)
|
||
|
{
|
||
|
INITIALIZE_PREFIX_TABLE_ENTRY(pEntry);
|
||
|
|
||
|
// Allocate the name space entry if there is no entry in the
|
||
|
// name page.
|
||
|
if (!fNameFound)
|
||
|
{
|
||
|
PWSTR pBuffer;
|
||
|
|
||
|
// Allocate the entry in the name page.
|
||
|
pBuffer = ALLOCATE_NAME_PAGE_ENTRY((pTable->NamePageList),(Name.Length/sizeof(WCHAR)));
|
||
|
|
||
|
if (pBuffer != NULL)
|
||
|
{
|
||
|
RtlCopyMemory(pBuffer,Name.Buffer,Name.Length);
|
||
|
pEntry->PathSegment = Name;
|
||
|
pEntry->PathSegment.Buffer = pBuffer;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
status = STATUS_NO_MEMORY;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
pEntry->PathSegment = Name;
|
||
|
|
||
|
// thread the entry to point to the parent.
|
||
|
pEntry->pParentEntry = pParentEntry;
|
||
|
|
||
|
// Insert the entry in the bucket.
|
||
|
INSERT_IN_BUCKET(pTable->Buckets[BucketNo],pEntry);
|
||
|
|
||
|
// Insert the entry in the parent's children list.
|
||
|
INSERT_IN_CHILD_LIST(pEntry, pParentEntry);
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
status = STATUS_NO_MEMORY;
|
||
|
DfsDbgTrace(0, Dbg, "DfsInsertInPrefixTable Error -- %lx\n",status);
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
// Increment the no. of children associated with this entry
|
||
|
|
||
|
pEntry->NoOfChildren++;
|
||
|
}
|
||
|
|
||
|
pParentEntry = pEntry;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
status = STATUS_INVALID_PARAMETER;
|
||
|
DfsDbgTrace(0, Dbg, "DfsInsertInPrefixTable Error -- %lx\n",status);
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// If a new entry was not successfully inserted we need to walk up the chain
|
||
|
// of parent entries to undo the increment to the reference count and
|
||
|
// remove the entries from their parent links.
|
||
|
if (NT_SUCCESS(status))
|
||
|
{
|
||
|
// The entry was successfully inserted in the prefix table. Update
|
||
|
// the data (BLOB) associated with it.
|
||
|
// We do it outside the loop to prevent redundant comparisons within
|
||
|
// the loop.
|
||
|
|
||
|
pEntry->pData = pData;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
while (pParentEntry != NULL)
|
||
|
{
|
||
|
PDFS_PREFIX_TABLE_ENTRY pMaybeTempEntry;
|
||
|
|
||
|
pMaybeTempEntry = pParentEntry;
|
||
|
pParentEntry = pParentEntry->pParentEntry;
|
||
|
|
||
|
if (--pMaybeTempEntry->NoOfChildren == 0) {
|
||
|
//
|
||
|
// If pParentEntry == NULL, pMaybeTempEntry is
|
||
|
// pTable->RootEntry. Do not try to remove it.
|
||
|
//
|
||
|
if (pParentEntry != NULL) {
|
||
|
REMOVE_FROM_CHILD_LIST(pMaybeTempEntry);
|
||
|
REMOVE_FROM_BUCKET(pMaybeTempEntry);
|
||
|
FREE_DFS_PREFIX_TABLE_ENTRY(pTable, pMaybeTempEntry);
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (NameBuffer != Buffer) {
|
||
|
ExFreePool( NameBuffer );
|
||
|
}
|
||
|
|
||
|
DfsDbgTrace(-1, Dbg, "DfsInsertInPrefixTable -- Exit\n", 0);
|
||
|
return status;
|
||
|
}
|
||
|
|
||
|
//+---------------------------------------------------------------------------
|
||
|
//
|
||
|
// Function: DfsLookupPrefixTable
|
||
|
//
|
||
|
// Synopsis: private fn. for looking up a name segment in a prefix table
|
||
|
//
|
||
|
// Arguments: [pTable] -- the DFS prefix table instance
|
||
|
//
|
||
|
// [pPath] -- the path to be looked up.
|
||
|
//
|
||
|
// [pSuffix] -- the suffix that could not be found.
|
||
|
//
|
||
|
// [ppData] -- placeholder for the BLOB for the prefix.
|
||
|
//
|
||
|
//
|
||
|
// Returns: one of the following NTSTATUS codes
|
||
|
// STATUS_SUCCESS -- call was successfull.
|
||
|
// STATUS_OBJECT_PATH_NOT_FOUND -- no entry for the path
|
||
|
//
|
||
|
// History: 04-18-94 SethuR Created
|
||
|
//
|
||
|
// Notes:
|
||
|
//
|
||
|
//----------------------------------------------------------------------------
|
||
|
|
||
|
NTSTATUS DfsLookupPrefixTable(PDFS_PREFIX_TABLE pTable,
|
||
|
PUNICODE_STRING pPath,
|
||
|
PUNICODE_STRING pSuffix,
|
||
|
PVOID *ppData)
|
||
|
{
|
||
|
NTSTATUS status = STATUS_SUCCESS;
|
||
|
PDFS_PREFIX_TABLE_ENTRY pEntry = NULL;
|
||
|
|
||
|
DfsDbgTrace(+1, Dbg, "DfsLookupInPrefixTable -- Entry\n", 0);
|
||
|
|
||
|
if (pPath->Length == 0)
|
||
|
{
|
||
|
DfsDbgTrace(-1, Dbg, "DfsLookupInPrefixTable Exited - Null Path!\n", 0);
|
||
|
return STATUS_SUCCESS;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
status = _LookupPrefixTable(pTable,pPath,pSuffix,&pEntry);
|
||
|
|
||
|
// Update the BLOB placeholder with the results of the lookup.
|
||
|
if (NT_SUCCESS(status))
|
||
|
{
|
||
|
*ppData = pEntry->pData;
|
||
|
}
|
||
|
|
||
|
DfsDbgTrace(-1, Dbg, "DfsLookupInPrefixTable -- Exit\n", 0);
|
||
|
return status;
|
||
|
}
|
||
|
|
||
|
}
|
||
|
|
||
|
//+---------------------------------------------------------------------------
|
||
|
//
|
||
|
// Function: DfsFindUnicodePrefix
|
||
|
//
|
||
|
// Synopsis: fn. for looking up a name segment in a prefix table
|
||
|
//
|
||
|
// Arguments: [pTable] -- the DFS prefix table instance
|
||
|
//
|
||
|
// [pPath] -- the path to be looked up.
|
||
|
//
|
||
|
// [pSuffix] -- the suffix that could not be found.
|
||
|
//
|
||
|
// Returns: a valid ptr if successfull, NULL otherwise
|
||
|
//
|
||
|
// History: 04-18-94 SethuR Created
|
||
|
//
|
||
|
// Notes:
|
||
|
//
|
||
|
//----------------------------------------------------------------------------
|
||
|
|
||
|
PVOID DfsFindUnicodePrefix(PDFS_PREFIX_TABLE pTable,
|
||
|
PUNICODE_STRING pPath,
|
||
|
PUNICODE_STRING pSuffix)
|
||
|
{
|
||
|
NTSTATUS status = STATUS_SUCCESS;
|
||
|
PDFS_PREFIX_TABLE_ENTRY pEntry = NULL;
|
||
|
PVOID pData = NULL;
|
||
|
|
||
|
DfsDbgTrace(+1, Dbg, "DfsFindUnicodePrefix -- Entry\n", 0);
|
||
|
|
||
|
if (pPath->Length == 0)
|
||
|
{
|
||
|
DfsDbgTrace(-1, Dbg, "DfsFindUnicodePrefix Exited - Null Path!\n", 0);
|
||
|
return NULL;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
status = _LookupPrefixTable(pTable,pPath,pSuffix,&pEntry);
|
||
|
|
||
|
// Update the BLOB placeholder with the results of the lookup.
|
||
|
if (NT_SUCCESS(status))
|
||
|
{
|
||
|
pData = pEntry->pData;
|
||
|
}
|
||
|
|
||
|
DfsDbgTrace(-1, Dbg, "DfsFindUnicodePrefix -- Exit\n", 0);
|
||
|
return pData;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
//+---------------------------------------------------------------------------
|
||
|
//
|
||
|
// Function: DfsRemoveFromPrefixTable
|
||
|
//
|
||
|
// Synopsis: private fn. for looking up a name segment in a prefix table
|
||
|
//
|
||
|
// Arguments: [pTable] -- the DFS prefix table instance
|
||
|
//
|
||
|
// [pPath] -- the path to be looked up.
|
||
|
//
|
||
|
// Returns: one of the following NTSTATUS codes
|
||
|
// STATUS_SUCCESS -- call was successfull.
|
||
|
// STATUS_OBJECT_PATH_NOT_FOUND -- no entry for the path
|
||
|
//
|
||
|
// History: 04-18-94 SethuR Created
|
||
|
//
|
||
|
// Notes:
|
||
|
//
|
||
|
//----------------------------------------------------------------------------
|
||
|
|
||
|
NTSTATUS DfsRemoveFromPrefixTable(PDFS_PREFIX_TABLE pTable,
|
||
|
PUNICODE_STRING pPath)
|
||
|
{
|
||
|
NTSTATUS status = STATUS_SUCCESS;
|
||
|
UNICODE_STRING Path,Suffix;
|
||
|
ULONG BucketNo;
|
||
|
|
||
|
PDFS_PREFIX_TABLE_ENTRY pEntry = NULL;
|
||
|
|
||
|
DfsDbgTrace(+1, Dbg, "DfsRemoveFromPrefixTable -- Entry\n", 0);
|
||
|
|
||
|
Suffix.Length = 0;
|
||
|
Suffix.Buffer = NULL;
|
||
|
|
||
|
if (pPath->Length == 0)
|
||
|
{
|
||
|
DfsDbgTrace(-1, Dbg, "DfsRemoveFromPrefixTable Exited -- Null Path!\n", 0);
|
||
|
return STATUS_SUCCESS;
|
||
|
}
|
||
|
|
||
|
else if ((pPath->Length == sizeof(WCHAR)) &&
|
||
|
(pPath->Buffer[0] == PATH_DELIMITER))
|
||
|
{
|
||
|
if (pTable->RootEntry.pData == NULL)
|
||
|
{
|
||
|
status = STATUS_OBJECT_PATH_NOT_FOUND;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
pTable->RootEntry.pData = NULL;
|
||
|
DfsDbgTrace(-1, Dbg, "DfsRemoveFromPrefixTable Exited.\n", 0);
|
||
|
return STATUS_SUCCESS;
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
Path.Length = pPath->Length - sizeof(WCHAR);
|
||
|
Path.MaximumLength = pPath->MaximumLength;
|
||
|
Path.Buffer = &pPath->Buffer[1];
|
||
|
|
||
|
status = _LookupPrefixTable(pTable,&Path,&Suffix,&pEntry);
|
||
|
|
||
|
if (NT_SUCCESS(status) && (Suffix.Length == 0))
|
||
|
{
|
||
|
// Destroy the association between the data associated with
|
||
|
// this prefix.
|
||
|
pEntry->pData = NULL;
|
||
|
|
||
|
// found an exact match for the given path name in the table.
|
||
|
// traverse the list of parent pointers and delete them if
|
||
|
// required.
|
||
|
|
||
|
while (pEntry != NULL)
|
||
|
{
|
||
|
if ((--pEntry->NoOfChildren) == 0)
|
||
|
{
|
||
|
PDFS_PREFIX_TABLE_ENTRY pTempEntry = pEntry;
|
||
|
pEntry = pEntry->pParentEntry;
|
||
|
|
||
|
//
|
||
|
// pEntry == NULL means pTempEntry is pTable->RootEntry.
|
||
|
// Do not try to remove it.
|
||
|
//
|
||
|
if (pEntry != NULL) {
|
||
|
REMOVE_FROM_CHILD_LIST(pTempEntry);
|
||
|
REMOVE_FROM_BUCKET(pTempEntry);
|
||
|
FREE_DFS_PREFIX_TABLE_ENTRY(pTable,pTempEntry);
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
DfsDbgTrace(-1, Dbg, "DfsRemoveFromPrefixTable -- Exit\n", 0);
|
||
|
return status;
|
||
|
}
|
||
|
|