Function nd6_free

freebsd/netinet6/nd6.c:1401–1538

* Free an nd6 llinfo entry. * Since the function would cause significant changes in the kernel, DO NOT * make it global, unless you have a strong reason for the change, and are sure * that the change is safe. * * Set noinline to be dtrace-friendly */

 * Set noinline to be dtrace-friendly
 */
static __noinline void
nd6_free(struct llentry **lnp, int gc)
{
	struct ifnet *ifp;
	struct llentry *ln;
	struct nd_defrouter *dr;

	ln = *lnp;
	*lnp = NULL;

	LLE_WLOCK_ASSERT(ln);
	ND6_RLOCK_ASSERT();

	ifp = lltable_get_ifp(ln->lle_tbl);
	if ((ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) != 0)
		dr = defrouter_lookup_locked(&ln->r_l3addr.addr6, ifp);
	else
		dr = NULL;
	ND6_RUNLOCK();

	if ((ln->la_flags & LLE_DELETED) == 0)
		EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);

	/*
	 * we used to have pfctlinput(PRC_HOSTDEAD) here.
	 * even though it is not harmful, it was not really necessary.
	 */

	/* cancel timer */
	nd6_llinfo_settimer_locked(ln, -1);

	if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
		if (dr != NULL && dr->expire &&
		    ln->ln_state == ND6_LLINFO_STALE && gc) {
			/*
			 * If the reason for the deletion is just garbage
			 * collection, and the neighbor is an active default
			 * router, do not delete it.  Instead, reset the GC
			 * timer using the router's lifetime.
			 * Simply deleting the entry would affect default
			 * router selection, which is not necessarily a good
			 * thing, especially when we're using router preference
			 * values.
			 * XXX: the check for ln_state would be redundant,
			 *      but we intentionally keep it just in case.
			 */
			if (dr->expire > time_uptime)
				nd6_llinfo_settimer_locked(ln,
				    (dr->expire - time_uptime) * hz);
			else
				nd6_llinfo_settimer_locked(ln,
				    (long)V_nd6_gctimer * hz);

			LLE_REMREF(ln);
			LLE_WUNLOCK(ln);
			defrouter_rele(dr);
			return;
		}