Function tunioctl

freebsd/net/if_tuntap.c:1456–1665

* the cdevsw interface is now pretty minimal. */

 * the cdevsw interface is now pretty minimal.
 */
static	int
tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
    struct thread *td)
{
	struct ifreq ifr, *ifrp;
	struct tuntap_softc *tp = dev->si_drv1;
	struct ifnet *ifp = TUN2IFP(tp);
	struct tuninfo *tunp;
	int error, iflags, ival;
	bool	l2tun;

	l2tun = (tp->tun_flags & TUN_L2) != 0;
	if (l2tun) {
		/* tap specific ioctls */
		switch(cmd) {
		/* VMware/VMnet port ioctl's */
#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD4)
		case _IO('V', 0):
			ival = IOCPARM_IVAL(data);
			data = (caddr_t)&ival;
			/* FALLTHROUGH */
#endif
		case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
			iflags = *(int *)data;
			iflags &= TUN_VMIO_FLAG_MASK;
			iflags &= ~IFF_CANTCHANGE;
			iflags |= IFF_UP;

			TUN_LOCK(tp);
			ifp->if_flags = iflags |
			    (ifp->if_flags & IFF_CANTCHANGE);
			TUN_UNLOCK(tp);

			return (0);
		case SIOCGIFADDR:	/* get MAC address of the remote side */
			TUN_LOCK(tp);
			bcopy(&tp->tun_ether.octet, data,
			    sizeof(tp->tun_ether.octet));
			TUN_UNLOCK(tp);

			return (0);
		case SIOCSIFADDR:	/* set MAC address of the remote side */
			TUN_LOCK(tp);
			bcopy(data, &tp->tun_ether.octet,
			    sizeof(tp->tun_ether.octet));
			TUN_UNLOCK(tp);

			return (0);
		case TAPSVNETHDR:
			ival = *(int *)data;
			if (ival != 0 &&
			    ival != sizeof(struct virtio_net_hdr) &&
			    ival != sizeof(struct virtio_net_hdr_mrg_rxbuf)) {
				return (EINVAL);
			}
			TUN_LOCK(tp);
			tun_vnethdr_set(ifp, ival);