https://git.reactos.org/?p=reactos.git;a=commitdiff;h=7eefe702949da68e49c4365d466c5373099c3b1f
commit 7eefe702949da68e49c4365d466c5373099c3b1f
Author: Pierre Schweitzer <pie...@reactos.org>
AuthorDate: Sun Nov 12 22:26:18 2017 +0100
[NTOSKRNL] Implement IoComputeDesiredAccessFileObject() based on checks
performed in NtFlushBuffersFile()
CORE-14003
---
ntoskrnl/include/internal/io.h | 7 +++++++
ntoskrnl/io/iomgr/util.c | 27 +++++++++++++++++++++++++++
2 files changed, 34 insertions(+)
diff --git a/ntoskrnl/include/internal/io.h b/ntoskrnl/include/internal/io.h
index 54a46906db..2a4c62f42d 100644
--- a/ntoskrnl/include/internal/io.h
+++ b/ntoskrnl/include/internal/io.h
@@ -1230,6 +1230,13 @@ IopDoNameTransmogrify(
IN PREPARSE_DATA_BUFFER DataBuffer
);
+NTSTATUS
+NTAPI
+IoComputeDesiredAccessFileObject(
+ IN PFILE_OBJECT FileObject,
+ IN PACCESS_MASK DesiredAccess
+);
+
//
// I/O Timer Routines
//
diff --git a/ntoskrnl/io/iomgr/util.c b/ntoskrnl/io/iomgr/util.c
index 14bfafda7c..7329dbf8f1 100644
--- a/ntoskrnl/io/iomgr/util.c
+++ b/ntoskrnl/io/iomgr/util.c
@@ -19,6 +19,33 @@ NTAPI
RtlpGetStackLimits(PULONG_PTR StackBase,
PULONG_PTR StackLimit);
+/* PRIVATE FUNCTIONS *********************************************************/
+
+NTSTATUS
+NTAPI
+IoComputeDesiredAccessFileObject(IN PFILE_OBJECT FileObject,
+ IN PACCESS_MASK DesiredAccess)
+{
+ /* Assume failure */
+ *DesiredAccess = 0;
+
+ /* First check we really have a FileObject */
+ if (OBJECT_TO_OBJECT_HEADER(FileObject)->Type != IoFileObjectType)
+ {
+ return STATUS_OBJECT_TYPE_MISMATCH;
+ }
+
+ /* Then compute desired access:
+ * Check if the handle has either FILE_WRITE_DATA or FILE_APPEND_DATA was
+ * granted. However, if this is a named pipe, make sure we don't ask for
+ * FILE_APPEND_DATA as it interferes with the FILE_CREATE_PIPE_INSTANCE
+ * access right!
+ */
+ *DesiredAccess = ((!(FileObject->Flags & FO_NAMED_PIPE) ? FILE_APPEND_DATA
: 0) | FILE_WRITE_DATA);
+
+ return STATUS_SUCCESS;
+}
+
/* FUNCTIONS *****************************************************************/
/*
