Function ng_ether_attach

freebsd/netgraph/ng_ether.c:303–347

* A new Ethernet interface has been attached. * Create a new node for it, etc. */

 * Create a new node for it, etc.
 */
static void
ng_ether_attach(struct ifnet *ifp)
{
	char name[IFNAMSIZ];
	priv_p priv;
	node_p node;

	/*
	 * Do not create / attach an ether node to this ifnet if
	 * a netgraph node with the same name already exists.
	 * This should prevent ether nodes to become attached to
	 * eiface nodes, which may be problematic due to naming
	 * clashes.
	 */
	ng_ether_sanitize_ifname(ifp->if_xname, name);
	if ((node = ng_name2noderef(NULL, name)) != NULL) {
		NG_NODE_UNREF(node);
		return;
	}

	/* Create node */
	KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __func__));
	if (ng_make_node_common(&ng_ether_typestruct, &node) != 0) {
		log(LOG_ERR, "%s: can't %s for %s\n",
		    __func__, "create node", ifp->if_xname);
		return;
	}

	/* Allocate private data */
	priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
	if (priv == NULL) {
		log(LOG_ERR, "%s: can't %s for %s\n",
		    __func__, "allocate memory", ifp->if_xname);
		NG_NODE_UNREF(node);
		return;
	}
	NG_NODE_SET_PRIVATE(node, priv);
	priv->ifp = ifp;
	IFP2NG(ifp) = node;
	priv->hwassist = ifp->if_hwassist;

	/* Try to give the node the same name as the interface */
	if (ng_name_node(node, name) != 0)
		log(LOG_WARNING, "%s: can't name node %s\n", __func__, name);
}

/*
 * An Ethernet interface is being detached.