#include <sys/mac_provider.h>

/*
 * Note, this example merely shows the structure of this function.
 * Different devices will have different ways to manage the set of
 * multicast MAC addresses that they can program into their filters and
 * they have different ways of keeping track of them. Like other
 * examples, this assumes that there is a lock which protects this data.
 * In this case we assume we have an array of structures that is used to
 * track each multicast entry and a count of valid entries.
 */

#define	EXAMPLE_NMULTICAST_ADDRS	100

static int
example_multicast_add(example_t *ep, const uint8_t *mac_addr)
{
	int i, ret;

	mutex_enter(&ep->ep_lock);
	for (i = 0; i < ep->ep_nmcast_addrs; i++) {
		if (bcmp(ep->ep_nmcast_addrs[i].ema_addr, mac_addr,
		    ETHERADDRL) == 0) {
			/*
			 * The address is alread in our list, so we can
			 * return and say we're done.
			 */
			mutex_exit(&ep->ep_lock);
			return (0);
		}
	}

	/*
	 * We need to add this multicast address to a filter, make sure
	 * we have enough space to do so.
	 */
	if (ep->ep_nmcast_addrs >= EXAMPLE_NMULTICAST_ADDRS) {
		mutex_exit(&ep->ep_lock);
		return (ENOSPC);
	}

	/*
	 * Program the device before we add it to our list. Assume zero
	 * means success.
	 */
	ret = example_program_add_mcast_filter(ep, mac_addr);
	if (ret == 0) {
		bcopy(mac_addr,
		    ep->ep_nmcast_addrs[ep->ep_nmcast_addrs].ema_addr,
		    ETHERADDRL);
		ep->ep_nmcast_addrs++;
	}

	mutex_exit(&ep->ep_lock);

	return (ret);
}

static int
example_multicast_remove(example_t *ep, const uint8_t *mac_addr)
{
	int i, ret;
	boolean_t found = B_FALSE;

	mutex_enter(&ep->ep_lock);
	for (i = 0; i < ep->ep_nmcast_addrs; i++) {
		if (bcmp(ep->ep_mcast_addrs[i].ema_addr, mac_addr,
		    ETHERADDRL) == 0) {
			found = B_TRUE;
			break;
		}
	}

	if (found == B_FALSE) {
		mutex_exit(&ep->ep_lock);
		return (ENOENT);
	}

	/*
	 * Assume that a return value of zero indicates that the removal
	 * was successful. Note that i still has the index of this
	 * entry.
	 */
	ret = example_program_rem_mcast_filter(ep, mac_addr);
	if (ret == 0) {
		int last = ep->ep_nmcast_addrs - 1;
		if (i != last) {
			bcopy(ep->ep_mcast_addrs[last].ema_addr,
			    ep->ep_mcast_addrs[i].ema_addr,
			    ETHERADDRL);
		}
		bzero(ep->ep_mcast_addrs[last].ema_addr,
		    ETHERADDRL);
		VERIFY(ep->ep_nmcast_addrs > 0);
		ep->ep_nmcast_addrs--;
	}

	mutex_exit(&ep->ep_lock);
	return (ret);
}

static int
example_m_multicst(void *arg, boolean_t add, const uint8_t *mac_addr)
{
	example_t *ep = arg;

	/*
	 * We sanity check that we've been given a multicast address.
	 */
	if ((mac_addr[0] & 0x01) == 0)
		return (EINVAL);

	if (add)
		return (example_multicast_add(ep, mac_addr);
	else
		return (example_multicast_remove(ep, mac_addr));
}