system/fstools.if: Add fstools_use_fds interface

policy/modules/system/fstools.if

@@ -81,6 +81,24 @@ interface(`fstools_signal',`
 	allow $1 fsadm_t:process signal;
 ')
 
+########################################
+## <summary>
+##	Inherit fstools file descriptors.
+## </summary>
+## <param name="domain">
+##	<summary>
+##	The type of the process performing this action.
+##	</summary>
+## </param>
+#
+interface(`fstools_use_fds',`
+	gen_require(`
+		type fsadm_t;
+	')
+
+	allow $1 fsadm_t:fd use;
+')
+
 ########################################
 ## <summary>
 ##	Read fstools unnamed pipes.