GRE_VERSION_0
if ((greh->flags & GRE_VERSION) != GRE_VERSION_0)
if ((greh->flags & GRE_VERSION) != GRE_VERSION_0)
case GRE_VERSION_0:
case GRE_VERSION_0:
if ((greh->flags & GRE_VERSION) != GRE_VERSION_0)
if ((greh->flags & GRE_VERSION) != GRE_VERSION_0)