+ /*
+ * If "service" is specified, then the kernel is indicating that
+ * we must use machine credentials for this request. (Regardless
+ * of the uid value or the setting of root_uses_machine_creds.)
+ * If the service value is "*", then any service name can be used.
+ * Otherwise, it specifies the service name that should be used.
+ * (For now, the values of service will only be "*" or "nfs".)
+ *
+ * Restricting gssd to use "nfs" service name is needed for when
+ * the NFS server is doing a callback to the NFS client. In this
+ * case, the NFS server has to authenticate itself as "nfs" --
+ * even if there are other service keys such as "host" or "root"
+ * in the keytab.
+ *
+ * Another case when the kernel may specify the service attribute
+ * is when gssd is being asked to create the context for a
+ * SETCLIENT_ID operation. In this case, machine credentials
+ * must be used for the authentication. However, the service name
+ * used for this case is not important.
+ *
+ */
+ printerr(2, "%s: service is '%s'\n", __func__,
+ service ? service : "<null>");
+ if (uid != 0 || (uid == 0 && root_uses_machine_creds == 0 &&
+ service == NULL)) {