Function ifa_alloc

freebsd/net/if.c:1821–1855

* Initialization, destruction and refcounting functions for ifaddrs. */

 * Initialization, destruction and refcounting functions for ifaddrs.
 */
struct ifaddr *
ifa_alloc(size_t size, int flags)
{
	struct ifaddr *ifa;

	KASSERT(size >= sizeof(struct ifaddr),
	    ("%s: invalid size %zu", __func__, size));

	ifa = malloc(size, M_IFADDR, M_ZERO | flags);
	if (ifa == NULL)
		return (NULL);

	if ((ifa->ifa_opackets = counter_u64_alloc(flags)) == NULL)
		goto fail;
	if ((ifa->ifa_ipackets = counter_u64_alloc(flags)) == NULL)
		goto fail;
	if ((ifa->ifa_obytes = counter_u64_alloc(flags)) == NULL)
		goto fail;
	if ((ifa->ifa_ibytes = counter_u64_alloc(flags)) == NULL)
		goto fail;

	refcount_init(&ifa->ifa_refcnt, 1);

	return (ifa);

fail:
	/* free(NULL) is okay */
	counter_u64_free(ifa->ifa_opackets);
	counter_u64_free(ifa->ifa_ipackets);
	counter_u64_free(ifa->ifa_obytes);
	counter_u64_free(ifa->ifa_ibytes);
	free(ifa, M_IFADDR);

	return (NULL);
}

void
ifa_ref(struct ifaddr *ifa)