tun_attach
err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER,
ret = tun_attach(tun, file, false, tun->flags & IFF_NAPI,
err = tun_attach(tun, tun->file, false, ifr->ifr_flags & IFF_NAPI,
EXPECT_EQ(tun_attach(self->fd, self->ifname), 0);
EXPECT_EQ(tun_attach(self->fd, self->ifname), 0);