Function in_purgemaddrs

freebsd/netinet/in.c:1209–1243

* Delete all IPv4 multicast address records, and associated link-layer * multicast address records, associated with ifp. * XXX It looks like domifdetach runs AFTER the link layer cleanup. * XXX This should not race with ifma_protospec being set during * a new allocation, if it does, we have bigger problems. */

 * a new allocation, if it does, we have bigger problems.
 */
static void
in_purgemaddrs(struct ifnet *ifp)
{
	struct in_multi_head purgeinms;
	struct in_multi		*inm;
	struct ifmultiaddr	*ifma, *next;

	SLIST_INIT(&purgeinms);
	IN_MULTI_LIST_LOCK();

	/*
	 * Extract list of in_multi associated with the detaching ifp
	 * which the PF_INET layer is about to release.
	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
	 * by code further down.
	 */
	IF_ADDR_WLOCK(ifp);
 restart:
	CK_STAILQ_FOREACH_SAFE(ifma, &ifp->if_multiaddrs, ifma_link, next) {
		if (ifma->ifma_addr->sa_family != AF_INET ||
		    ifma->ifma_protospec == NULL)
			continue;
		inm = (struct in_multi *)ifma->ifma_protospec;
		inm_rele_locked(&purgeinms, inm);
		if (__predict_false(ifma_restart)) {
			ifma_restart = true;
			goto restart;
		}
	}
	IF_ADDR_WUNLOCK(ifp);

	inm_release_list_deferred(&purgeinms);
	igmp_ifdetach(ifp);
	IN_MULTI_LIST_UNLOCK();
}

struct in_llentry {
	struct llentry		base;