807 lines
16 KiB
C
807 lines
16 KiB
C
/*++
|
|
|
|
Copyright (c) 1989 Microsoft Corporation
|
|
|
|
Module Name:
|
|
|
|
PrefxSup.c
|
|
|
|
Abstract:
|
|
|
|
This module implements the Udfs Prefix support routines
|
|
|
|
Author:
|
|
|
|
Dan Lovinger [DanLo] 8-Oct-1996
|
|
|
|
Revision History:
|
|
|
|
--*/
|
|
|
|
#include "UdfProcs.h"
|
|
|
|
|
|
// The Bug check file id for this module
|
|
|
|
|
|
#define BugCheckFileId (UDFS_BUG_CHECK_PREFXSUP)
|
|
|
|
|
|
// The local debug trace level
|
|
|
|
|
|
#define Dbg (UDFS_DEBUG_LEVEL_READ)
|
|
|
|
|
|
// Local support routines.
|
|
|
|
|
|
PLCB
|
|
UdfFindNameLink (
|
|
IN PIRP_CONTEXT IrpContext,
|
|
IN PRTL_SPLAY_LINKS *RootNode,
|
|
IN PUNICODE_STRING Name
|
|
);
|
|
|
|
BOOLEAN
|
|
UdfInsertNameLink (
|
|
IN PIRP_CONTEXT IrpContext,
|
|
IN PRTL_SPLAY_LINKS *RootNode,
|
|
IN PLCB NameLink
|
|
);
|
|
|
|
#ifdef ALLOC_PRAGMA
|
|
#pragma alloc_text(PAGE, UdfFindNameLink)
|
|
#pragma alloc_text(PAGE, UdfFindPrefix)
|
|
#pragma alloc_text(PAGE, UdfInitializeLcbFromDirContext)
|
|
#pragma alloc_text(PAGE, UdfInsertNameLink)
|
|
#pragma alloc_text(PAGE, UdfInsertPrefix)
|
|
#pragma alloc_text(PAGE, UdfRemovePrefix)
|
|
#endif
|
|
|
|
|
|
PLCB
|
|
UdfInsertPrefix (
|
|
IN PIRP_CONTEXT IrpContext,
|
|
IN PFCB Fcb,
|
|
IN PUNICODE_STRING Name,
|
|
IN BOOLEAN ShortNameMatch,
|
|
IN BOOLEAN IgnoreCase,
|
|
IN PFCB ParentFcb
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This routine inserts an Lcb linking the two Fcbs together.
|
|
|
|
Arguments:
|
|
|
|
Fcb - This is the Fcb whose name is being inserted into the tree.
|
|
|
|
Name - This is the name for the component.
|
|
|
|
ShortNameMatch - Indicates whether this name was found on an explicit 8.3 search
|
|
|
|
IgnoreCase - Indicates if we should insert into the case-insensitive tree.
|
|
|
|
ParentFcb - This is the ParentFcb. The prefix tree is attached to this.
|
|
|
|
Return Value:
|
|
|
|
PLCB - the Lcb inserted.
|
|
|
|
--*/
|
|
|
|
{
|
|
PLCB Lcb;
|
|
PRTL_SPLAY_LINKS *TreeRoot;
|
|
PLIST_ENTRY ListLinks;
|
|
ULONG Flags;
|
|
|
|
PWCHAR NameBuffer;
|
|
|
|
PAGED_CODE();
|
|
|
|
|
|
// Check inputs.
|
|
|
|
|
|
ASSERT_IRP_CONTEXT( IrpContext );
|
|
ASSERT_FCB( Fcb );
|
|
|
|
ASSERT_EXCLUSIVE_FCB( Fcb );
|
|
ASSERT_EXCLUSIVE_FCB( ParentFcb );
|
|
ASSERT_FCB_INDEX( ParentFcb );
|
|
|
|
|
|
// It must be the case that an index Fcb is only referenced by a single index. Now
|
|
// we walk the child's Lcb queue to insure that if any prefixes have already been
|
|
// inserted, they all refer to the index Fcb we are linking to. This is the only way
|
|
// we can detect directory cross-linkage.
|
|
|
|
|
|
if (SafeNodeType( Fcb ) == UDFS_NTC_FCB_INDEX) {
|
|
|
|
for (ListLinks = Fcb->ParentLcbQueue.Flink;
|
|
ListLinks != &Fcb->ParentLcbQueue;
|
|
ListLinks = ListLinks->Flink) {
|
|
|
|
Lcb = CONTAINING_RECORD( ListLinks, LCB, ChildFcbLinks );
|
|
|
|
if (Lcb->ParentFcb != ParentFcb) {
|
|
|
|
UdfRaiseStatus( IrpContext, STATUS_DISK_CORRUPT_ERROR );
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
// Capture the separate cases.
|
|
|
|
|
|
if (IgnoreCase) {
|
|
|
|
TreeRoot = &ParentFcb->IgnoreCaseRoot;
|
|
Flags = LCB_FLAG_IGNORE_CASE;
|
|
|
|
} else {
|
|
|
|
TreeRoot = &ParentFcb->ExactCaseRoot;
|
|
Flags = 0;
|
|
}
|
|
|
|
if (ShortNameMatch) {
|
|
|
|
SetFlag( Flags, LCB_FLAG_SHORT_NAME );
|
|
}
|
|
|
|
|
|
// Allocate space for the Lcb.
|
|
|
|
|
|
if ( sizeof( LCB ) + Name->Length > SIZEOF_LOOKASIDE_LCB ) {
|
|
|
|
Lcb = FsRtlAllocatePoolWithTag( UdfPagedPool,
|
|
sizeof( LCB ) + Name->Length,
|
|
TAG_LCB );
|
|
|
|
SetFlag( Flags, LCB_FLAG_POOL_ALLOCATED );
|
|
|
|
} else {
|
|
|
|
Lcb = ExAllocateFromPagedLookasideList( &UdfLcbLookasideList );
|
|
}
|
|
|
|
|
|
// Set the type and size.
|
|
|
|
|
|
Lcb->NodeTypeCode = UDFS_NTC_LCB;
|
|
Lcb->NodeByteSize = sizeof( LCB ) + Name->Length;
|
|
|
|
|
|
// Initialize the name-based file attributes.
|
|
|
|
|
|
Lcb->FileAttributes = 0;
|
|
|
|
|
|
// Set up the filename in the Lcb.
|
|
|
|
|
|
Lcb->FileName.Length =
|
|
Lcb->FileName.MaximumLength = Name->Length;
|
|
|
|
Lcb->FileName.Buffer = Add2Ptr( Lcb, sizeof( LCB ), PWCHAR );
|
|
|
|
RtlCopyMemory( Lcb->FileName.Buffer,
|
|
Name->Buffer,
|
|
Name->Length );
|
|
|
|
|
|
// Insert the Lcb into the prefix tree.
|
|
|
|
|
|
Lcb->Flags = Flags;
|
|
|
|
if (!UdfInsertNameLink( IrpContext,
|
|
TreeRoot,
|
|
Lcb )) {
|
|
|
|
|
|
// This will very rarely occur.
|
|
|
|
|
|
UdfFreePool( &Lcb );
|
|
|
|
Lcb = UdfFindNameLink( IrpContext,
|
|
TreeRoot,
|
|
Name );
|
|
|
|
if (Lcb == NULL) {
|
|
|
|
|
|
// Even worse.
|
|
|
|
|
|
UdfRaiseStatus( IrpContext, STATUS_DRIVER_INTERNAL_ERROR );
|
|
}
|
|
|
|
return Lcb;
|
|
}
|
|
|
|
|
|
// Link the Fcbs together through the Lcb.
|
|
|
|
|
|
Lcb->ParentFcb = ParentFcb;
|
|
Lcb->ChildFcb = Fcb;
|
|
|
|
InsertHeadList( &ParentFcb->ChildLcbQueue, &Lcb->ParentFcbLinks );
|
|
InsertHeadList( &Fcb->ParentLcbQueue, &Lcb->ChildFcbLinks );
|
|
|
|
|
|
// Initialize the reference count.
|
|
|
|
|
|
Lcb->Reference = 0;
|
|
|
|
return Lcb;
|
|
}
|
|
|
|
|
|
VOID
|
|
UdfRemovePrefix (
|
|
IN PIRP_CONTEXT IrpContext,
|
|
IN PLCB Lcb
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This routine is called to remove a given prefix of an Fcb.
|
|
|
|
Arguments:
|
|
|
|
Lcb - the prefix being removed.
|
|
|
|
Return Value:
|
|
|
|
None
|
|
|
|
--*/
|
|
|
|
{
|
|
PAGED_CODE();
|
|
|
|
|
|
// Check inputs.
|
|
|
|
|
|
ASSERT_IRP_CONTEXT( IrpContext );
|
|
ASSERT_LCB( Lcb );
|
|
|
|
|
|
// Check the acquisition of the two Fcbs.
|
|
|
|
|
|
ASSERT_EXCLUSIVE_FCB_OR_VCB( Lcb->ParentFcb );
|
|
ASSERT_EXCLUSIVE_FCB_OR_VCB( Lcb->ChildFcb );
|
|
|
|
|
|
// Now remove the linkage and delete the Lcb.
|
|
|
|
|
|
RemoveEntryList( &Lcb->ParentFcbLinks );
|
|
RemoveEntryList( &Lcb->ChildFcbLinks );
|
|
|
|
if (FlagOn( Lcb->Flags, LCB_FLAG_IGNORE_CASE )) {
|
|
|
|
Lcb->ParentFcb->IgnoreCaseRoot = RtlDelete( &Lcb->Links );
|
|
|
|
} else {
|
|
|
|
Lcb->ParentFcb->ExactCaseRoot = RtlDelete( &Lcb->Links );
|
|
}
|
|
|
|
if (FlagOn( Lcb->Flags, LCB_FLAG_POOL_ALLOCATED )) {
|
|
|
|
ExFreePool( Lcb );
|
|
|
|
} else {
|
|
|
|
ExFreeToPagedLookasideList( &UdfLcbLookasideList, Lcb );
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
|
|
PLCB
|
|
UdfFindPrefix (
|
|
IN PIRP_CONTEXT IrpContext,
|
|
IN OUT PFCB *CurrentFcb,
|
|
IN OUT PUNICODE_STRING RemainingName,
|
|
IN BOOLEAN IgnoreCase
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This routine begins from the given CurrentFcb and walks through all of
|
|
components of the name looking for the longest match in the prefix
|
|
splay trees. The search is relative to the starting Fcb so the
|
|
full name may not begin with a '\'. On return this routine will
|
|
update Current Fcb with the lowest point it has travelled in the
|
|
tree. It will also hold only that resource on return and it must
|
|
hold that resource.
|
|
|
|
Arguments:
|
|
|
|
CurrentFcb - Address to store the lowest Fcb we find on this search.
|
|
On return we will have acquired this Fcb. On entry this is the
|
|
Fcb to examine.
|
|
|
|
RemainingName - Supplies a buffer to store the exact case of the name being
|
|
searched for. Initially will contain the upcase name based on the
|
|
IgnoreCase flag.
|
|
|
|
IgnoreCase - Indicates if we are doing a case-insensitive compare.
|
|
|
|
Return Value:
|
|
|
|
The Lcb used to find the current Fcb, NULL if we didn't find any prefix
|
|
Fcbs.
|
|
|
|
--*/
|
|
|
|
{
|
|
UNICODE_STRING LocalRemainingName;
|
|
UNICODE_STRING FinalName;
|
|
|
|
PLCB NameLink;
|
|
PLCB CurrentLcb = NULL;
|
|
|
|
PAGED_CODE();
|
|
|
|
|
|
// Check inputs.
|
|
|
|
|
|
ASSERT_IRP_CONTEXT( IrpContext );
|
|
ASSERT_FCB( *CurrentFcb );
|
|
ASSERT_EXCLUSIVE_FCB( *CurrentFcb );
|
|
|
|
|
|
// Make a local copy of the input strings.
|
|
|
|
|
|
LocalRemainingName = *RemainingName;
|
|
|
|
|
|
// Loop until we find the longest matching prefix.
|
|
|
|
|
|
while (TRUE) {
|
|
|
|
|
|
// If there are no characters left or we are not at an IndexFcb then
|
|
// return immediately.
|
|
|
|
|
|
if ((LocalRemainingName.Length == 0) ||
|
|
(SafeNodeType( *CurrentFcb ) != UDFS_NTC_FCB_INDEX)) {
|
|
|
|
return CurrentLcb;
|
|
}
|
|
|
|
|
|
// Split off the next component from the name.
|
|
|
|
|
|
UdfDissectName( IrpContext,
|
|
&LocalRemainingName,
|
|
&FinalName );
|
|
|
|
|
|
// Check if this name is in the splay tree for this Scb.
|
|
|
|
|
|
if (IgnoreCase) {
|
|
|
|
NameLink = UdfFindNameLink( IrpContext,
|
|
&(*CurrentFcb)->IgnoreCaseRoot,
|
|
&FinalName );
|
|
|
|
} else {
|
|
|
|
NameLink = UdfFindNameLink( IrpContext,
|
|
&(*CurrentFcb)->ExactCaseRoot,
|
|
&FinalName );
|
|
}
|
|
|
|
|
|
// If we didn't find a match then exit.
|
|
|
|
|
|
if (NameLink == NULL) {
|
|
|
|
break;
|
|
}
|
|
|
|
CurrentLcb = NameLink;
|
|
|
|
|
|
// If this is a case-insensitive match then copy the exact case of the name into
|
|
// the input buffer.
|
|
|
|
|
|
if (IgnoreCase) {
|
|
|
|
RtlCopyMemory( FinalName.Buffer,
|
|
NameLink->FileName.Buffer,
|
|
NameLink->FileName.Length );
|
|
}
|
|
|
|
|
|
// Update the caller's remaining name string to reflect the fact that we found
|
|
// a match.
|
|
|
|
|
|
*RemainingName = LocalRemainingName;
|
|
|
|
|
|
// Move down to the next component in the tree. Acquire without waiting.
|
|
// If this fails then lock the Fcb to reference this Fcb and then drop
|
|
// the parent and acquire the child.
|
|
|
|
|
|
ASSERT( NameLink->ParentFcb == *CurrentFcb );
|
|
|
|
if (!UdfAcquireFcbExclusive( IrpContext, NameLink->ChildFcb, TRUE )) {
|
|
|
|
|
|
// If we can't wait then raise CANT_WAIT.
|
|
|
|
|
|
if (!FlagOn( IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT )) {
|
|
|
|
UdfRaiseStatus( IrpContext, STATUS_CANT_WAIT );
|
|
}
|
|
|
|
UdfLockVcb( IrpContext, IrpContext->Vcb );
|
|
NameLink->ChildFcb->FcbReference += 1;
|
|
NameLink->Reference += 1;
|
|
UdfUnlockVcb( IrpContext, IrpContext->Vcb );
|
|
|
|
UdfReleaseFcb( IrpContext, *CurrentFcb );
|
|
UdfAcquireFcbExclusive( IrpContext, NameLink->ChildFcb, FALSE );
|
|
|
|
UdfLockVcb( IrpContext, IrpContext->Vcb );
|
|
NameLink->ChildFcb->FcbReference -= 1;
|
|
NameLink->Reference -= 1;
|
|
UdfUnlockVcb( IrpContext, IrpContext->Vcb );
|
|
|
|
} else {
|
|
|
|
UdfReleaseFcb( IrpContext, *CurrentFcb );
|
|
}
|
|
|
|
*CurrentFcb = NameLink->ChildFcb;
|
|
}
|
|
|
|
return CurrentLcb;
|
|
}
|
|
|
|
|
|
|
|
VOID
|
|
UdfInitializeLcbFromDirContext (
|
|
IN PIRP_CONTEXT IrpContext,
|
|
IN PLCB Lcb,
|
|
IN PDIR_ENUM_CONTEXT DirContext
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This routine performs common initialization of Lcbs from found directory
|
|
entries.
|
|
|
|
Arguments:
|
|
|
|
Lcb - the Lcb to initialize.
|
|
|
|
DirContext - the directory enumeration context, enumerated to the FID associated
|
|
with this Lcb.
|
|
|
|
Return Value:
|
|
|
|
None.
|
|
|
|
--*/
|
|
|
|
{
|
|
PAGED_CODE();
|
|
|
|
|
|
// Check inputs.
|
|
|
|
|
|
ASSERT_IRP_CONTEXT( IrpContext );
|
|
ASSERT_LCB( Lcb );
|
|
|
|
ASSERT( DirContext->Fid != NULL );
|
|
|
|
|
|
// This is falling down trivial now. Simply update the hidden flag in the Lcb.
|
|
|
|
|
|
if (FlagOn( DirContext->Fid->Flags, NSR_FID_F_HIDDEN )) {
|
|
|
|
SetFlag( Lcb->FileAttributes, FILE_ATTRIBUTE_HIDDEN );
|
|
}
|
|
}
|
|
|
|
|
|
|
|
// Local support routine
|
|
|
|
|
|
PLCB
|
|
UdfFindNameLink (
|
|
IN PIRP_CONTEXT IrpContext,
|
|
IN PRTL_SPLAY_LINKS *RootNode,
|
|
IN PUNICODE_STRING Name
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This routine searches through a splay link tree looking for a match for the
|
|
input name. If we find the corresponding name we will rebalance the
|
|
tree.
|
|
|
|
Arguments:
|
|
|
|
RootNode - Supplies the parent to search.
|
|
|
|
Name - This is the name to search for. Note if we are doing a case
|
|
insensitive search the name would have been upcased already.
|
|
|
|
Return Value:
|
|
|
|
PLCB - The name link found or NULL if there is no match.
|
|
|
|
--*/
|
|
|
|
{
|
|
FSRTL_COMPARISON_RESULT Comparison;
|
|
PLCB Node;
|
|
PRTL_SPLAY_LINKS Links;
|
|
|
|
PAGED_CODE();
|
|
|
|
Links = *RootNode;
|
|
|
|
while (Links != NULL) {
|
|
|
|
Node = CONTAINING_RECORD( Links, LCB, Links );
|
|
|
|
|
|
// Compare the prefix in the tree with the full name
|
|
|
|
|
|
Comparison = UdfFullCompareNames( IrpContext, &Node->FileName, Name );
|
|
|
|
|
|
// See if they don't match
|
|
|
|
|
|
if (Comparison == GreaterThan) {
|
|
|
|
|
|
// The prefix is greater than the full name
|
|
// so we go down the left child
|
|
|
|
|
|
Links = RtlLeftChild( Links );
|
|
|
|
|
|
// And continue searching down this tree
|
|
|
|
|
|
} else if (Comparison == LessThan) {
|
|
|
|
|
|
// The prefix is less than the full name
|
|
// so we go down the right child
|
|
|
|
|
|
Links = RtlRightChild( Links );
|
|
|
|
|
|
// And continue searching down this tree
|
|
|
|
|
|
} else {
|
|
|
|
|
|
// We found it.
|
|
|
|
// Splay the tree and save the new root.
|
|
|
|
|
|
*RootNode = RtlSplay( Links );
|
|
|
|
return Node;
|
|
}
|
|
}
|
|
|
|
|
|
// We didn't find the Link.
|
|
|
|
|
|
return NULL;
|
|
}
|
|
|
|
|
|
|
|
// Local support routine
|
|
|
|
|
|
BOOLEAN
|
|
UdfInsertNameLink (
|
|
IN PIRP_CONTEXT IrpContext,
|
|
IN PRTL_SPLAY_LINKS *RootNode,
|
|
IN PLCB NameLink
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This routine will insert a name in the splay tree pointed to
|
|
by RootNode.
|
|
|
|
Arguments:
|
|
|
|
RootNode - Supplies a pointer to the table.
|
|
|
|
NameLink - Contains the new link to enter.
|
|
|
|
Return Value:
|
|
|
|
BOOLEAN - TRUE if the name is inserted, FALSE otherwise.
|
|
|
|
--*/
|
|
|
|
{
|
|
FSRTL_COMPARISON_RESULT Comparison;
|
|
PLCB Node;
|
|
|
|
PAGED_CODE();
|
|
|
|
|
|
// Check inputs.
|
|
|
|
|
|
ASSERT_IRP_CONTEXT( IrpContext );
|
|
|
|
RtlInitializeSplayLinks( &NameLink->Links );
|
|
|
|
|
|
// If we are the first entry in the tree, just become the root.
|
|
|
|
|
|
if (*RootNode == NULL) {
|
|
|
|
*RootNode = &NameLink->Links;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
Node = CONTAINING_RECORD( *RootNode, LCB, Links );
|
|
|
|
while (TRUE) {
|
|
|
|
|
|
// Compare the prefix in the tree with the prefix we want
|
|
// to insert.
|
|
|
|
|
|
Comparison = UdfFullCompareNames( IrpContext, &Node->FileName, &NameLink->FileName );
|
|
|
|
|
|
// If we found the entry, return immediately.
|
|
|
|
|
|
if (Comparison == EqualTo) { return FALSE; }
|
|
|
|
|
|
// If the tree prefix is greater than the new prefix then
|
|
// we go down the left subtree
|
|
|
|
|
|
if (Comparison == GreaterThan) {
|
|
|
|
|
|
// We want to go down the left subtree, first check to see
|
|
// if we have a left subtree
|
|
|
|
|
|
if (RtlLeftChild( &Node->Links ) == NULL) {
|
|
|
|
|
|
// there isn't a left child so we insert ourselves as the
|
|
// new left child
|
|
|
|
|
|
RtlInsertAsLeftChild( &Node->Links, &NameLink->Links );
|
|
|
|
|
|
// and exit the while loop
|
|
|
|
|
|
break;
|
|
|
|
} else {
|
|
|
|
|
|
// there is a left child so simply go down that path, and
|
|
// go back to the top of the loop
|
|
|
|
|
|
Node = CONTAINING_RECORD( RtlLeftChild( &Node->Links ),
|
|
LCB,
|
|
Links );
|
|
}
|
|
|
|
} else {
|
|
|
|
|
|
// The tree prefix is either less than or a proper prefix
|
|
// of the new string. We treat both cases as less than when
|
|
// we do insert. So we want to go down the right subtree,
|
|
// first check to see if we have a right subtree
|
|
|
|
|
|
if (RtlRightChild( &Node->Links ) == NULL) {
|
|
|
|
|
|
// These isn't a right child so we insert ourselves as the
|
|
// new right child
|
|
|
|
|
|
RtlInsertAsRightChild( &Node->Links, &NameLink->Links );
|
|
|
|
|
|
// and exit the while loop
|
|
|
|
|
|
break;
|
|
|
|
} else {
|
|
|
|
|
|
// there is a right child so simply go down that path, and
|
|
// go back to the top of the loop
|
|
|
|
|
|
Node = CONTAINING_RECORD( RtlRightChild( &Node->Links ),
|
|
LCB,
|
|
Links );
|
|
}
|
|
}
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|