mirror of
https://github.com/reactos/reactos.git
synced 2024-09-11 05:12:43 +00:00
554 lines
16 KiB
C
554 lines
16 KiB
C
/*
|
|
* PROJECT: ReactOS Kernel
|
|
* LICENSE: GPL - See COPYING in the top level directory
|
|
* FILE: ntoskrnl/ob/oblink.c
|
|
* PURPOSE: Implements symbolic links
|
|
* PROGRAMMERS: Alex Ionescu (alex@relsoft.net)
|
|
* David Welch (welch@mcmail.com)
|
|
*/
|
|
|
|
/* INCLUDES *****************************************************************/
|
|
|
|
#include <ntoskrnl.h>
|
|
#define NDEBUG
|
|
#include <debug.h>
|
|
|
|
/* GLOBALS ******************************************************************/
|
|
|
|
POBJECT_TYPE ObSymbolicLinkType = NULL;
|
|
|
|
/* PRIVATE FUNCTIONS *********************************************************/
|
|
|
|
VOID
|
|
NTAPI
|
|
ObpDeleteSymbolicLinkName(IN POBJECT_SYMBOLIC_LINK SymbolicLink)
|
|
{
|
|
/* FIXME: Device maps not supported yet */
|
|
|
|
}
|
|
|
|
VOID
|
|
NTAPI
|
|
ObpCreateSymbolicLinkName(IN POBJECT_SYMBOLIC_LINK SymbolicLink)
|
|
{
|
|
POBJECT_HEADER ObjectHeader;
|
|
POBJECT_HEADER_NAME_INFO ObjectNameInfo;
|
|
|
|
/* Get header data */
|
|
ObjectHeader = OBJECT_TO_OBJECT_HEADER(SymbolicLink);
|
|
ObjectNameInfo = OBJECT_HEADER_TO_NAME_INFO(ObjectHeader);
|
|
|
|
/* Check if we are not actually in a directory with a device map */
|
|
if (!(ObjectNameInfo) ||
|
|
!(ObjectNameInfo->Directory) ||
|
|
!(ObjectNameInfo->Directory->DeviceMap))
|
|
{
|
|
/* There's nothing to do, return */
|
|
return;
|
|
}
|
|
|
|
/* FIXME: We don't support device maps yet */
|
|
DPRINT1("Unhandled path!\n");
|
|
ASSERT(FALSE);
|
|
}
|
|
|
|
/*++
|
|
* @name ObpDeleteSymbolicLink
|
|
*
|
|
* The ObpDeleteSymbolicLink routine <FILLMEIN>
|
|
*
|
|
* @param ObjectBody
|
|
* <FILLMEIN>
|
|
*
|
|
* @return None.
|
|
*
|
|
* @remarks None.
|
|
*
|
|
*--*/
|
|
VOID
|
|
NTAPI
|
|
ObpDeleteSymbolicLink(PVOID ObjectBody)
|
|
{
|
|
POBJECT_SYMBOLIC_LINK SymlinkObject = (POBJECT_SYMBOLIC_LINK)ObjectBody;
|
|
|
|
/* Make sure that the symbolic link has a name */
|
|
if (SymlinkObject->LinkTarget.Buffer)
|
|
{
|
|
/* Free the name */
|
|
ExFreePool(SymlinkObject->LinkTarget.Buffer);
|
|
SymlinkObject->LinkTarget.Buffer = NULL;
|
|
}
|
|
}
|
|
|
|
/*++
|
|
* @name ObpParseSymbolicLink
|
|
*
|
|
* The ObpParseSymbolicLink routine <FILLMEIN>
|
|
*
|
|
* @param Object
|
|
* <FILLMEIN>
|
|
*
|
|
* @param NextObject
|
|
* <FILLMEIN>
|
|
*
|
|
* @param FullPath
|
|
* <FILLMEIN>
|
|
*
|
|
* @param RemainingPath
|
|
* <FILLMEIN>
|
|
*
|
|
* @param Attributes
|
|
* <FILLMEIN>
|
|
*
|
|
* @return STATUS_SUCCESS or appropriate error value.
|
|
*
|
|
* @remarks None.
|
|
*
|
|
*--*/
|
|
NTSTATUS
|
|
NTAPI
|
|
ObpParseSymbolicLink(IN PVOID ParsedObject,
|
|
IN PVOID ObjectType,
|
|
IN OUT PACCESS_STATE AccessState,
|
|
IN KPROCESSOR_MODE AccessMode,
|
|
IN ULONG Attributes,
|
|
IN OUT PUNICODE_STRING FullPath,
|
|
IN OUT PUNICODE_STRING RemainingName,
|
|
IN OUT PVOID Context OPTIONAL,
|
|
IN PSECURITY_QUALITY_OF_SERVICE SecurityQos OPTIONAL,
|
|
OUT PVOID *NextObject)
|
|
{
|
|
POBJECT_SYMBOLIC_LINK SymlinkObject = (POBJECT_SYMBOLIC_LINK)ParsedObject;
|
|
PUNICODE_STRING TargetPath;
|
|
PWSTR NewTargetPath;
|
|
ULONG LengthUsed, MaximumLength;
|
|
NTSTATUS Status;
|
|
PAGED_CODE();
|
|
|
|
/* Assume failure */
|
|
*NextObject = NULL;
|
|
|
|
/* Check if we're out of name to parse */
|
|
if (!RemainingName->Length)
|
|
{
|
|
/* Check if we got an object type */
|
|
if (ObjectType)
|
|
{
|
|
/* Reference the object only */
|
|
Status = ObReferenceObjectByPointer(ParsedObject,
|
|
0,
|
|
ObjectType,
|
|
AccessMode);
|
|
if (NT_SUCCESS(Status))
|
|
{
|
|
/* Return it */
|
|
*NextObject = ParsedObject;
|
|
}
|
|
|
|
if ((NT_SUCCESS(Status)) || (Status != STATUS_OBJECT_TYPE_MISMATCH))
|
|
{
|
|
/* Fail */
|
|
return Status;
|
|
}
|
|
}
|
|
}
|
|
else if (RemainingName->Buffer[0] != OBJ_NAME_PATH_SEPARATOR)
|
|
{
|
|
/* Symbolic links must start with a backslash */
|
|
return STATUS_OBJECT_TYPE_MISMATCH;
|
|
}
|
|
|
|
/* Set the target path and length */
|
|
TargetPath = &SymlinkObject->LinkTarget;
|
|
LengthUsed = TargetPath->Length + RemainingName->Length;
|
|
|
|
/* Optimization: check if the new name is shorter */
|
|
if (FullPath->MaximumLength <= LengthUsed)
|
|
{
|
|
/* It's not, allocate a new one */
|
|
MaximumLength = LengthUsed + sizeof(WCHAR);
|
|
NewTargetPath = ExAllocatePoolWithTag(NonPagedPool,
|
|
MaximumLength,
|
|
TAG_SYMLINK_TTARGET);
|
|
if (!NewTargetPath) return STATUS_INSUFFICIENT_RESOURCES;
|
|
}
|
|
else
|
|
{
|
|
/* It is! Reuse the name... */
|
|
MaximumLength = FullPath->MaximumLength;
|
|
NewTargetPath = FullPath->Buffer;
|
|
}
|
|
|
|
/* Make sure we have a length */
|
|
if (RemainingName->Length)
|
|
{
|
|
/* Copy the new path */
|
|
RtlMoveMemory((PVOID)((ULONG_PTR)NewTargetPath + TargetPath->Length),
|
|
RemainingName->Buffer,
|
|
RemainingName->Length);
|
|
}
|
|
|
|
/* Copy the target path and null-terminate it */
|
|
RtlCopyMemory(NewTargetPath, TargetPath->Buffer, TargetPath->Length);
|
|
NewTargetPath[LengthUsed / sizeof(WCHAR)] = UNICODE_NULL;
|
|
|
|
/* If the optimization didn't work, free the old buffer */
|
|
if (NewTargetPath != FullPath->Buffer) ExFreePool(FullPath->Buffer);
|
|
|
|
/* Update the path values */
|
|
FullPath->Length = (USHORT)LengthUsed;
|
|
FullPath->MaximumLength = (USHORT)MaximumLength;
|
|
FullPath->Buffer = NewTargetPath;
|
|
|
|
/* Tell the parse routine to start reparsing */
|
|
return STATUS_REPARSE;
|
|
}
|
|
|
|
/* PUBLIC FUNCTIONS **********************************************************/
|
|
|
|
/*++
|
|
* @name NtCreateSymbolicLinkObject
|
|
* @implemented NT4
|
|
*
|
|
* The NtCreateSymbolicLinkObject opens or creates a symbolic link object.
|
|
*
|
|
* @param LinkHandle
|
|
* Variable which receives the symlink handle.
|
|
*
|
|
* @param DesiredAccess
|
|
* Desired access to the symlink.
|
|
*
|
|
* @param ObjectAttributes
|
|
* Structure describing the symlink.
|
|
*
|
|
* @param LinkTarget
|
|
* Unicode string defining the symlink's target
|
|
*
|
|
* @return STATUS_SUCCESS or appropriate error value.
|
|
*
|
|
* @remarks None.
|
|
*
|
|
*--*/
|
|
NTSTATUS
|
|
NTAPI
|
|
NtCreateSymbolicLinkObject(OUT PHANDLE LinkHandle,
|
|
IN ACCESS_MASK DesiredAccess,
|
|
IN POBJECT_ATTRIBUTES ObjectAttributes,
|
|
IN PUNICODE_STRING LinkTarget)
|
|
{
|
|
HANDLE hLink;
|
|
POBJECT_SYMBOLIC_LINK SymbolicLink;
|
|
UNICODE_STRING CapturedLinkTarget;
|
|
KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
|
|
NTSTATUS Status;
|
|
PAGED_CODE();
|
|
|
|
/* Check if we need to probe parameters */
|
|
if (PreviousMode != KernelMode)
|
|
{
|
|
_SEH2_TRY
|
|
{
|
|
/* Probe the target */
|
|
CapturedLinkTarget = ProbeForReadUnicodeString(LinkTarget);
|
|
ProbeForRead(CapturedLinkTarget.Buffer,
|
|
CapturedLinkTarget.MaximumLength,
|
|
sizeof(WCHAR));
|
|
|
|
/* Probe the return handle */
|
|
ProbeForWriteHandle(LinkHandle);
|
|
}
|
|
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
|
|
{
|
|
/* Return the exception code */
|
|
_SEH2_YIELD(return _SEH2_GetExceptionCode());
|
|
}
|
|
_SEH2_END;
|
|
}
|
|
else
|
|
{
|
|
/* No need to capture */
|
|
CapturedLinkTarget = *LinkTarget;
|
|
}
|
|
|
|
/* Check if the maximum length is odd */
|
|
if (CapturedLinkTarget.MaximumLength % sizeof(WCHAR))
|
|
{
|
|
/* Round it down */
|
|
CapturedLinkTarget.MaximumLength =
|
|
(USHORT)ALIGN_DOWN(CapturedLinkTarget.MaximumLength, WCHAR);
|
|
}
|
|
|
|
/* Fail if the length is odd, or if the maximum is smaller or 0 */
|
|
if ((CapturedLinkTarget.Length % sizeof(WCHAR)) ||
|
|
(CapturedLinkTarget.MaximumLength < CapturedLinkTarget.Length) ||
|
|
!(CapturedLinkTarget.MaximumLength))
|
|
{
|
|
/* This message is displayed on the debugger in Windows */
|
|
DbgPrint("OB: Invalid symbolic link target - %wZ\n",
|
|
&CapturedLinkTarget);
|
|
return STATUS_INVALID_PARAMETER;
|
|
}
|
|
|
|
/* Create the object */
|
|
Status = ObCreateObject(PreviousMode,
|
|
ObSymbolicLinkType,
|
|
ObjectAttributes,
|
|
PreviousMode,
|
|
NULL,
|
|
sizeof(OBJECT_SYMBOLIC_LINK),
|
|
0,
|
|
0,
|
|
(PVOID*)&SymbolicLink);
|
|
if (NT_SUCCESS(Status))
|
|
{
|
|
/* Success! Fill in the creation time immediately */
|
|
KeQuerySystemTime(&SymbolicLink->CreationTime);
|
|
|
|
/* Setup the target name */
|
|
SymbolicLink->LinkTarget.Length = CapturedLinkTarget.Length;
|
|
SymbolicLink->LinkTarget.MaximumLength = CapturedLinkTarget.Length +
|
|
sizeof(WCHAR);
|
|
SymbolicLink->LinkTarget.Buffer =
|
|
ExAllocatePoolWithTag(PagedPool,
|
|
CapturedLinkTarget.MaximumLength,
|
|
TAG_SYMLINK_TARGET);
|
|
if (!SymbolicLink->LinkTarget.Buffer) return STATUS_NO_MEMORY;
|
|
|
|
/* Copy it */
|
|
RtlCopyMemory(SymbolicLink->LinkTarget.Buffer,
|
|
CapturedLinkTarget.Buffer,
|
|
CapturedLinkTarget.MaximumLength);
|
|
|
|
/* Initialize the remaining name, dos drive index and target object */
|
|
SymbolicLink->LinkTargetObject = NULL;
|
|
SymbolicLink->DosDeviceDriveIndex = 0;
|
|
RtlInitUnicodeString(&SymbolicLink->LinkTargetRemaining, NULL);
|
|
|
|
/* Insert it into the object tree */
|
|
Status = ObInsertObject(SymbolicLink,
|
|
NULL,
|
|
DesiredAccess,
|
|
0,
|
|
NULL,
|
|
&hLink);
|
|
if (NT_SUCCESS(Status))
|
|
{
|
|
_SEH2_TRY
|
|
{
|
|
/* Return the handle to caller */
|
|
*LinkHandle = hLink;
|
|
}
|
|
_SEH2_EXCEPT(ExSystemExceptionFilter())
|
|
{
|
|
/* Get exception code */
|
|
Status = _SEH2_GetExceptionCode();
|
|
}
|
|
_SEH2_END;
|
|
}
|
|
}
|
|
|
|
/* Return status to caller */
|
|
return Status;
|
|
}
|
|
|
|
/*++
|
|
* @name NtOpenSymbolicLinkObject
|
|
* @implemented NT4
|
|
*
|
|
* The NtOpenSymbolicLinkObject opens a symbolic link object.
|
|
*
|
|
* @param LinkHandle
|
|
* Variable which receives the symlink handle.
|
|
*
|
|
* @param DesiredAccess
|
|
* Desired access to the symlink.
|
|
*
|
|
* @param ObjectAttributes
|
|
* Structure describing the symlink.
|
|
*
|
|
* @return STATUS_SUCCESS or appropriate error value.
|
|
*
|
|
* @remarks None.
|
|
*
|
|
*--*/
|
|
NTSTATUS
|
|
NTAPI
|
|
NtOpenSymbolicLinkObject(OUT PHANDLE LinkHandle,
|
|
IN ACCESS_MASK DesiredAccess,
|
|
IN POBJECT_ATTRIBUTES ObjectAttributes)
|
|
{
|
|
HANDLE hLink;
|
|
KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
|
|
NTSTATUS Status;
|
|
PAGED_CODE();
|
|
|
|
/* Check if we need to probe parameters */
|
|
if (PreviousMode != KernelMode)
|
|
{
|
|
_SEH2_TRY
|
|
{
|
|
/* Probe the return handle */
|
|
ProbeForWriteHandle(LinkHandle);
|
|
}
|
|
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
|
|
{
|
|
/* Return the exception code */
|
|
_SEH2_YIELD(return _SEH2_GetExceptionCode());
|
|
}
|
|
_SEH2_END;
|
|
}
|
|
|
|
/* Open the object */
|
|
Status = ObOpenObjectByName(ObjectAttributes,
|
|
ObSymbolicLinkType,
|
|
PreviousMode,
|
|
NULL,
|
|
DesiredAccess,
|
|
NULL,
|
|
&hLink);
|
|
if (NT_SUCCESS(Status))
|
|
{
|
|
_SEH2_TRY
|
|
{
|
|
/* Return the handle to caller */
|
|
*LinkHandle = hLink;
|
|
}
|
|
_SEH2_EXCEPT(ExSystemExceptionFilter())
|
|
{
|
|
/* Get exception code */
|
|
Status = _SEH2_GetExceptionCode();
|
|
}
|
|
_SEH2_END;
|
|
}
|
|
|
|
/* Return status to caller */
|
|
return Status;
|
|
}
|
|
|
|
/*++
|
|
* @name NtQuerySymbolicLinkObject
|
|
* @implemented NT4
|
|
*
|
|
* The NtQuerySymbolicLinkObject queries a symbolic link object.
|
|
*
|
|
* @param LinkHandle
|
|
* Symlink handle to query
|
|
*
|
|
* @param LinkTarget
|
|
* Unicode string defining the symlink's target
|
|
*
|
|
* @param ResultLength
|
|
* Caller supplied storage for the number of bytes written (or NULL).
|
|
*
|
|
* @return STATUS_SUCCESS or appropriate error value.
|
|
*
|
|
* @remarks None.
|
|
*
|
|
*--*/
|
|
NTSTATUS
|
|
NTAPI
|
|
NtQuerySymbolicLinkObject(IN HANDLE LinkHandle,
|
|
OUT PUNICODE_STRING LinkTarget,
|
|
OUT PULONG ResultLength OPTIONAL)
|
|
{
|
|
UNICODE_STRING SafeLinkTarget = { 0, 0, NULL };
|
|
POBJECT_SYMBOLIC_LINK SymlinkObject;
|
|
KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
|
|
NTSTATUS Status;
|
|
ULONG LengthUsed;
|
|
PAGED_CODE();
|
|
|
|
if (PreviousMode != KernelMode)
|
|
{
|
|
_SEH2_TRY
|
|
{
|
|
/* Probe the unicode string for read and write */
|
|
ProbeForWriteUnicodeString(LinkTarget);
|
|
|
|
/* Probe the unicode string's buffer for write */
|
|
SafeLinkTarget = *LinkTarget;
|
|
ProbeForWrite(SafeLinkTarget.Buffer,
|
|
SafeLinkTarget.MaximumLength,
|
|
sizeof(WCHAR));
|
|
|
|
/* Probe the return length */
|
|
if (ResultLength) ProbeForWriteUlong(ResultLength);
|
|
}
|
|
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
|
|
{
|
|
/* Return the exception code */
|
|
_SEH2_YIELD(return _SEH2_GetExceptionCode());
|
|
}
|
|
_SEH2_END;
|
|
}
|
|
else
|
|
{
|
|
/* No need to probe */
|
|
SafeLinkTarget = *LinkTarget;
|
|
}
|
|
|
|
/* Reference the object */
|
|
Status = ObReferenceObjectByHandle(LinkHandle,
|
|
SYMBOLIC_LINK_QUERY,
|
|
ObSymbolicLinkType,
|
|
PreviousMode,
|
|
(PVOID *)&SymlinkObject,
|
|
NULL);
|
|
if (NT_SUCCESS(Status))
|
|
{
|
|
/* Lock the object */
|
|
ObpAcquireObjectLock(OBJECT_TO_OBJECT_HEADER(SymlinkObject));
|
|
|
|
/*
|
|
* So here's the thing: If you specify a return length, then the
|
|
* implementation will use the maximum length. If you don't, then
|
|
* it will use the length.
|
|
*/
|
|
LengthUsed = ResultLength ? SymlinkObject->LinkTarget.MaximumLength :
|
|
SymlinkObject->LinkTarget.Length;
|
|
|
|
/* Enter SEH so we can safely copy */
|
|
_SEH2_TRY
|
|
{
|
|
/* Make sure our buffer will fit */
|
|
if (LengthUsed <= SafeLinkTarget.MaximumLength)
|
|
{
|
|
/* Copy the buffer */
|
|
RtlCopyMemory(SafeLinkTarget.Buffer,
|
|
SymlinkObject->LinkTarget.Buffer,
|
|
LengthUsed);
|
|
|
|
/* Copy the new length */
|
|
LinkTarget->Length = SymlinkObject->LinkTarget.Length;
|
|
}
|
|
else
|
|
{
|
|
/* Otherwise set the failure status */
|
|
Status = STATUS_BUFFER_TOO_SMALL;
|
|
}
|
|
|
|
/* In both cases, check if the required length was requested */
|
|
if (ResultLength)
|
|
{
|
|
/* Then return it */
|
|
*ResultLength = SymlinkObject->LinkTarget.MaximumLength;
|
|
}
|
|
}
|
|
_SEH2_EXCEPT(ExSystemExceptionFilter())
|
|
{
|
|
/* Get the error code */
|
|
Status = _SEH2_GetExceptionCode();
|
|
}
|
|
_SEH2_END;
|
|
|
|
/* Unlock and dereference the object */
|
|
ObpReleaseObjectLock(OBJECT_TO_OBJECT_HEADER(SymlinkObject));
|
|
ObDereferenceObject(SymlinkObject);
|
|
}
|
|
|
|
/* Return query status */
|
|
return Status;
|
|
}
|
|
|
|
/* EOF */
|