Function vlan_clone_create

freebsd/net/if_vlan.c:976–1130

}

static int
vlan_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
{
	char *dp;
	bool wildcard = false;
	bool subinterface = false;
	int unit;
	int error;
	int vid = 0;
	uint16_t proto = ETHERTYPE_VLAN;
	struct ifvlan *ifv;
	struct ifnet *ifp;
	struct ifnet *p = NULL;
	struct ifaddr *ifa;
	struct sockaddr_dl *sdl;
	struct vlanreq vlr;
	static const u_char eaddr[ETHER_ADDR_LEN];	/* 00:00:00:00:00:00 */


	/*
	 * There are three ways to specify the cloned device:
	 * o pass a parameter block with the clone request.
	 * o specify parameters in the text of the clone device name
	 * o specify no parameters and get an unattached device that
	 *   must be configured separately.
	 * The first technique is preferred; the latter two are supported
	 * for backwards compatibility.
	 *
	 * XXXRW: Note historic use of the word "tag" here.  New ioctls may be
	 * called for.
	 */

	if (params) {
		error = copyin(params, &vlr, sizeof(vlr));
		if (error)
			return error;
		vid = vlr.vlr_tag;
		proto = vlr.vlr_proto;

		p = ifunit_ref(vlr.vlr_parent);
		if (p == NULL)
			return (ENXIO);
	}

	if ((error = ifc_name2unit(name, &unit)) == 0) {

		/*
		 * vlanX interface. Set wildcard to true if the unit number
		 * is not fixed (-1)
		 */
		wildcard = (unit < 0);
	} else {
		struct ifnet *p_tmp = vlan_clone_match_ethervid(name, &vid);
		if (p_tmp != NULL) {
			error = 0;
			subinterface = true;
			unit = IF_DUNIT_NONE;
			wildcard = false;