Function in6_ifattach

freebsd/netinet6/in6_ifattach.c:674–742

* XXX multiple loopback interface needs more care. for instance, * nodelocal address needs to be configured onto only one of them. * XXX multiple link-local address case * * altifp - secondary EUI64 source */

 * altifp - secondary EUI64 source
 */
void
in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
{
	struct in6_ifaddr *ia;

	if (ifp->if_afdata[AF_INET6] == NULL)
		return;
	/*
	 * quirks based on interface type
	 */
	switch (ifp->if_type) {
	case IFT_STF:
		/*
		 * 6to4 interface is a very special kind of beast.
		 * no multicast, no linklocal.  RFC2529 specifies how to make
		 * linklocals for 6to4 interface, but there's no use and
		 * it is rather harmful to have one.
		 */
		ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL;
		ND_IFINFO(ifp)->flags |= ND6_IFF_NO_DAD;
		break;
	default:
		break;
	}

	/*
	 * usually, we require multicast capability to the interface
	 */
	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
		nd6log((LOG_INFO, "in6_ifattach: "
		    "%s is not multicast capable, IPv6 not enabled\n",
		    if_name(ifp)));
		return;
	}

	/*
	 * assign loopback address for loopback interface.
	 */
	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
		/*
		 * check that loopback address doesn't exist yet.
		 */
		ia = in6ifa_ifwithaddr(&in6addr_loopback, 0);
		if (ia == NULL)
			in6_ifattach_loopback(ifp);
		else
			ifa_free(&ia->ia_ifa);
	}

	/*
	 * assign a link-local address, if there's none.
	 */
	if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
	    ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) {
		struct epoch_tracker et;

		NET_EPOCH_ENTER(et);
		ia = in6ifa_ifpforlinklocal(ifp, 0);