dbus, init: add interface for pidfd usage

Commit 4e7511f4a previously added access for init to use DBUS system bus
file descriptors while the intended access was for pidfds. Add an
interface for pidfd usage so that when pidfds are eventually handled
separately from regular fds, this interface can be adjusted.

Signed-off-by: Kenton Groombridge <concord@gentoo.org>

policy/modules/services/dbus.if

@@ -621,6 +621,25 @@ interface(`dbus_use_system_bus_fds',`
 	allow $1 system_dbusd_t:fd use;
 ')
 
+########################################
+## <summary>
+##	Use PIDFD file descriptors from the
+##	DBUS system bus.
+## </summary>
+## <param name="domain">
+##	<summary>
+##	Domain allowed access.
+##	</summary>
+## </param>
+#
+interface(`dbus_use_system_bus_pidfds',`
+	gen_require(`
+		type system_dbusd_t;
+	')
+
+	allow $1 system_dbusd_t:fd use;
+')
+
 ########################################
 ## <summary>
 ##	Do not audit attempts to read and

policy/modules/system/init.te

@@ -610,7 +610,7 @@ ifdef(`init_systemd',`
 
 	optional_policy(`
 		dbus_connect_system_bus(init_t)
-		dbus_use_system_bus_fds(init_t)
+		dbus_use_system_bus_pidfds(init_t)
 	')
 
 	optional_policy(`