Function ng_ether_rcv_lower

freebsd/netgraph/ng_ether.c:662–705

* Handle an mbuf received on the "lower" or "orphan" hook. */

 * Handle an mbuf received on the "lower" or "orphan" hook.
 */
static int
ng_ether_rcv_lower(hook_p hook, item_p item)
{
	struct mbuf *m;
	const node_p node = NG_HOOK_NODE(hook);
	const priv_p priv = NG_NODE_PRIVATE(node);
 	struct ifnet *const ifp = priv->ifp;

	NGI_GET_M(item, m);
	NG_FREE_ITEM(item);

	/* Check whether interface is ready for packets */

	if (!((ifp->if_flags & IFF_UP) &&
	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
		NG_FREE_M(m);
		return (ENETDOWN);
	}

	/* Make sure header is fully pulled up */
	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
		NG_FREE_M(m);
		return (EINVAL);
	}
	if (m->m_len < sizeof(struct ether_header)
	    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
		return (ENOBUFS);

	/* Drop in the MAC address if desired */
	if (priv->autoSrcAddr) {
		/* Make the mbuf writable if it's not already */
		if (!M_WRITABLE(m)
		    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
			return (ENOBUFS);

		/* Overwrite source MAC address */
		bcopy(IF_LLADDR(ifp),
		    mtod(m, struct ether_header *)->ether_shost,
		    ETHER_ADDR_LEN);
	}

	/* Send it on its way */
	return ether_output_frame(ifp, m);
}

/*
 * Handle an mbuf received on the "upper" hook.