Function in6_ifattach_linklocal

freebsd/netinet6/in6_ifattach.c:420–532

* altifp - secondary EUI64 source */

 * altifp - secondary EUI64 source
 */
static int
in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
{
	struct in6_ifaddr *ia;
	struct in6_aliasreq ifra;
	struct nd_prefixctl pr0;
	struct epoch_tracker et;
	struct nd_prefix *pr;
	int error;

	/*
	 * configure link-local address.
	 */
	in6_prepare_ifra(&ifra, NULL, &in6mask64);

	ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
	} else {
		NET_EPOCH_ENTER(et);
		error = get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr);
		NET_EPOCH_EXIT(et);
		if (error != 0) {
			nd6log((LOG_ERR,
			    "%s: no ifid available\n", if_name(ifp)));
			return (-1);
		}
	}
	if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
		return (-1);

	/* link-local addresses should NEVER expire. */
	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;

	/*
	 * Now call in6_update_ifa() to do a bunch of procedures to configure
	 * a link-local address. We can set the 3rd argument to NULL, because
	 * we know there's no other link-local address on the interface
	 * and therefore we are adding one (instead of updating one).
	 */
	if ((error = in6_update_ifa(ifp, &ifra, NULL,
				    IN6_IFAUPDATE_DADDELAY)) != 0) {
		/*
		 * XXX: When the interface does not support IPv6, this call
		 * would fail in the SIOCSIFADDR ioctl.  I believe the
		 * notification is rather confusing in this case, so just
		 * suppress it.  (jinmei@kame.net 20010130)
		 */
		if (error != EAFNOSUPPORT)
			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
			    "configure a link-local address on %s "
			    "(errno=%d)\n",
			    if_name(ifp), error));
		return (-1);
	}