Function vlan_unconfig_locked

freebsd/net/if_vlan.c:1546–1619

}

static void
vlan_unconfig_locked(struct ifnet *ifp, int departing)
{
	struct ifvlantrunk *trunk;
	struct vlan_mc_entry *mc;
	struct ifvlan *ifv;
	struct ifnet  *parent;
	int error;

	VLAN_XLOCK_ASSERT();

	ifv = ifp->if_softc;
	trunk = ifv->ifv_trunk;
	parent = NULL;

	if (trunk != NULL) {
		parent = trunk->parent;

		/*
		 * Since the interface is being unconfigured, we need to
		 * empty the list of multicast groups that we may have joined
		 * while we were alive from the parent's list.
		 */
		while ((mc = CK_SLIST_FIRST(&ifv->vlan_mc_listhead)) != NULL) {
			/*
			 * If the parent interface is being detached,
			 * all its multicast addresses have already
			 * been removed.  Warn about errors if
			 * if_delmulti() does fail, but don't abort as
			 * all callers expect vlan destruction to
			 * succeed.
			 */
			if (!departing) {
				error = if_delmulti(parent,
				    (struct sockaddr *)&mc->mc_addr);
				if (error)
					if_printf(ifp,
		    "Failed to delete multicast address from parent: %d\n",
					    error);
			}
			CK_SLIST_REMOVE_HEAD(&ifv->vlan_mc_listhead, mc_entries);
			NET_EPOCH_CALL(vlan_mc_free, &mc->mc_epoch_ctx);
		}

		vlan_setflags(ifp, 0); /* clear special flags on parent */

		vlan_remhash(trunk, ifv);
		ifv->ifv_trunk = NULL;

		/*
		 * Check if we were the last.
		 */
		if (trunk->refcnt == 0) {
			parent->if_vlantrunk = NULL;
			NET_EPOCH_WAIT();
			trunk_destroy(trunk);
		}
	}