Subject: get receiving interface index while no message is received

From: Yang Hongyang <[email-masked]>
Date: Fri, 08 Aug 2008 12:27:06 +0800

when I use getsockopt(sk, IPPROTO_IPV6, IPV6_2292PKTOPTIONS,(char *)incmsg, &cnt)
to get receiving interface index while no message is received,

What interface index should be returned?