IPPROTO_* should match the protocol field on the wire, which I gather isn't different. And I'm assuming there is no standard API defined already...
What about using a socket option? +-DLS - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html