get_kdc_offset
if (id->ops->get_kdc_offset == NULL) {
return (*id->ops->get_kdc_offset)(context, id, offset);
krb5_error_code (KRB5_CALLCONV * get_kdc_offset)(krb5_context, krb5_ccache, krb5_deltat *);
get_kdc_offset(context, cache);