Implement kernel handle encoding

xtoskrnl/ob/handle.cc

@@ -0,0 +1,76 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/ob/handle.cc
+ * DESCRIPTION:     Object Manager Handle Management
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
+ */
+
+#include <xtos.hh>
+
+
+/**
+ * Encodes a standard handle into a kernel-space handle.
+ *
+ * @param Handle
+ *        Supplies the raw standard handle to be encoded.
+ *
+ * @return This routine returns the encoded kernel handle.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+HANDLE
+OB::Handle::DecodeKernelHandle(IN HANDLE Handle)
+{
+    /* Clear the kernel handle flag */
+    return (HANDLE)(OBJECT_HANDLE_KERNEL_MASK ^ (ULONG_PTR)Handle);
+}
+
+/**
+ * Decodes a kernel-space handle into a standard handle.
+ *
+ * @param Handle
+ *        Supplies the encoded kernel handle to be decoded.
+ *
+ * @return This routine returns the decoded standard handle.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+HANDLE
+OB::Handle::EncodeKernelHandle(IN HANDLE Handle)
+{
+    /* Set the kernel handle flag */
+    return (HANDLE)(OBJECT_HANDLE_KERNEL_MASK | (ULONG_PTR)Handle);
+}
+
+/**
+ * Retrieves and decodes the handle attributes from a given handle table entry.
+ *
+ * @param HandleTableEntry
+ *        Supplies a pointer to the handle table entry to inspect.
+ *
+ * @return This routine returns a bitmask representing the active handle attributes.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+ULONG
+OB::Handle::GetHandleAttributes(IN PHANDLE_TABLE_ENTRY HandleTableEntry)
+{
+    ULONG Attributes;
+
+    /* Extract the base attributes */
+    Attributes = HandleTableEntry->ObAttributes;
+
+    /* Check if the protect-on-close access bit is set */
+    if(HandleTableEntry->GrantedAccess & OBJECT_ACCESS_PROTECT_CLOSE_BIT)
+    {
+        /* Retain valid handle attributes and set the protect-close flag */
+        return (Attributes & OBJECT_HANDLE_ATTRIBUTES) | OBJECT_PROTECT_CLOSE;
+    }
+
+    /* Isolate and return the inherit and audit-on-close flags */
+    return Attributes & (OBJECT_INHERIT | OBJECT_AUDIT_OBJECT_CLOSE);
+}