https://git.reactos.org/?p=reactos.git;a=commitdiff;h=3b64f7f8fbbc64ada4dfdb6bdd1feff4bac10c1d
commit 3b64f7f8fbbc64ada4dfdb6bdd1feff4bac10c1d
Author: Pierre Schweitzer <pie...@reactos.org>
AuthorDate: Sun Nov 12 22:28:54 2017 +0100
[NTOSKRNL] Implement (with many FIXMEs) ObReferenceFileObjectForWrite() so
that it can already do the job!
CORE-14003
---
ntoskrnl/include/internal/ob.h | 9 ++++
ntoskrnl/ob/obref.c | 108 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 117 insertions(+)
diff --git a/ntoskrnl/include/internal/ob.h b/ntoskrnl/include/internal/ob.h
index a78b5ad457..374f4a2c3e 100644
--- a/ntoskrnl/include/internal/ob.h
+++ b/ntoskrnl/include/internal/ob.h
@@ -384,6 +384,15 @@ ObpDeleteObjectType(
IN PVOID Object
);
+NTSTATUS
+NTAPI
+ObReferenceFileObjectForWrite(
+ IN HANDLE Handle,
+ IN KPROCESSOR_MODE AccessMode,
+ OUT PFILE_OBJECT *FileObject,
+ OUT POBJECT_HANDLE_INFORMATION HandleInformation
+);
+
//
// DOS Devices Functions
//
diff --git a/ntoskrnl/ob/obref.c b/ntoskrnl/ob/obref.c
index 00e2188069..2f4da20149 100644
--- a/ntoskrnl/ob/obref.c
+++ b/ntoskrnl/ob/obref.c
@@ -15,6 +15,8 @@
#define NDEBUG
#include <debug.h>
+extern ULONG ObpAccessProtectCloseBit;
+
/* PRIVATE FUNCTIONS *********************************************************/
BOOLEAN
@@ -195,6 +197,112 @@ ObFastReplaceObject(IN PEX_FAST_REF FastRef,
return OldObject;
}
+NTSTATUS
+NTAPI
+ObReferenceFileObjectForWrite(IN HANDLE Handle,
+ IN KPROCESSOR_MODE AccessMode,
+ OUT PFILE_OBJECT *FileObject,
+ OUT POBJECT_HANDLE_INFORMATION HandleInformation)
+{
+ NTSTATUS Status;
+ PHANDLE_TABLE HandleTable;
+ POBJECT_HEADER ObjectHeader;
+ PHANDLE_TABLE_ENTRY HandleEntry;
+ ACCESS_MASK GrantedAccess, DesiredAccess;
+
+ /* Assume failure */
+ *FileObject = NULL;
+
+ /* Check if this is a special handle */
+ if (HandleToLong(Handle) < 0)
+ {
+ /* Make sure we have a valid kernel handle */
+ if (AccessMode != KernelMode || Handle == NtCurrentProcess() || Handle
== NtCurrentThread())
+ {
+ return STATUS_INVALID_HANDLE;
+ }
+
+ /* Use the kernel handle table and get the actual handle value */
+ Handle = ObKernelHandleToHandle(Handle);
+ HandleTable = ObpKernelHandleTable;
+ }
+ else
+ {
+ /* Otherwise use this process's handle table */
+ HandleTable = PsGetCurrentProcess()->ObjectTable;
+ }
+
+ ASSERT(HandleTable != NULL);
+ KeEnterCriticalRegion();
+
+ /* Get the handle entry */
+ HandleEntry = ExMapHandleToPointer(HandleTable, Handle);
+ if (HandleEntry)
+ {
+ /* Get the object header and validate the type*/
+ ObjectHeader = ObpGetHandleObject(HandleEntry);
+
+ /* Get the desired access from the file object */
+ if
(!NT_SUCCESS(IoComputeDesiredAccessFileObject((PFILE_OBJECT)&ObjectHeader->Body,
+ &DesiredAccess)))
+ {
+ Status = STATUS_OBJECT_TYPE_MISMATCH;
+ }
+ else
+ {
+ /* Extract the granted access from the handle entry */
+ if (BooleanFlagOn(NtGlobalFlag, FLG_KERNEL_STACK_TRACE_DB))
+ {
+ /* FIXME: Translate granted access */
+ GrantedAccess = HandleEntry->GrantedAccess;
+ }
+ else
+ {
+ GrantedAccess = HandleEntry->GrantedAccess &
~ObpAccessProtectCloseBit;
+ }
+
+ /* FIXME: Get handle information for audit */
+
+ HandleInformation->GrantedAccess = GrantedAccess;
+
+ /* FIXME: Get handle attributes */
+ HandleInformation->HandleAttributes = 0;
+
+ /* Do granted and desired access match? */
+ if (GrantedAccess & DesiredAccess)
+ {
+ /* FIXME: Audit access if required */
+
+ /* Reference the object directly since we have its header */
+ InterlockedIncrement(&ObjectHeader->PointerCount);
+
+ /* Unlock the handle */
+ ExUnlockHandleTableEntry(HandleTable, HandleEntry);
+ KeLeaveCriticalRegion();
+
+ *FileObject = (PFILE_OBJECT)&ObjectHeader->Body;
+
+ /* Return success */
+ ASSERT(*FileObject != NULL);
+ return STATUS_SUCCESS;
+ }
+
+ /* No match, deny write access */
+ Status = STATUS_ACCESS_DENIED;
+
+ ExUnlockHandleTableEntry(HandleTable, HandleEntry);
+ }
+ }
+ else
+ {
+ Status = STATUS_INVALID_HANDLE;
+ }
+
+ /* Return failure status */
+ KeLeaveCriticalRegion();
+ return Status;
+}
+
/* PUBLIC FUNCTIONS *********************************************************/
LONG_PTR
