IPV6_TCLASS
#ifdef IPV6_TCLASS
IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1)
# ifdef IPV6_TCLASS
if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS,
IPV6_TCLASS, IPPROTO_IPV6);
case IPV6_TCLASS:
case IPV6_TCLASS:
case IPV6_TCLASS:
if (optname == -1 || optname == IPV6_TCLASS)
case IPV6_TCLASS:
case IPV6_TCLASS: