Function bridge_ioctl_add

freebsd/net/if_bridge.c:1140–1269

}

static int
bridge_ioctl_add(struct bridge_softc *sc, void *arg)
{
	struct ifbreq *req = arg;
	struct bridge_iflist *bif = NULL;
	struct ifnet *ifs;
	int error = 0;

	ifs = ifunit(req->ifbr_ifsname);
	if (ifs == NULL)
		return (ENOENT);
	if (ifs->if_ioctl == NULL)	/* must be supported */
		return (EINVAL);

	/* If it's in the span list, it can't be a member. */
	CK_LIST_FOREACH(bif, &sc->sc_spanlist, bif_next)
		if (ifs == bif->bif_ifp)
			return (EBUSY);

	if (ifs->if_bridge == sc)
		return (EEXIST);

	if (ifs->if_bridge != NULL)
		return (EBUSY);

	switch (ifs->if_type) {
	case IFT_ETHER:
	case IFT_L2VLAN:
	case IFT_GIF:
		/* permitted interface types */
		break;
	default:
		return (EINVAL);
	}

#ifdef INET6
	/*
	 * Two valid inet6 addresses with link-local scope must not be
	 * on the parent interface and the member interfaces at the
	 * same time.  This restriction is needed to prevent violation
	 * of link-local scope zone.  Attempts to add a member
	 * interface which has inet6 addresses when the parent has
	 * inet6 triggers removal of all inet6 addresses on the member
	 * interface.
	 */

	/* Check if the parent interface has a link-local scope addr. */
	if (V_allow_llz_overlap == 0 &&
	    in6ifa_llaonifp(sc->sc_ifp) != NULL) {
		/*
		 * If any, remove all inet6 addresses from the member
		 * interfaces.
		 */
		CK_LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 			if (in6ifa_llaonifp(bif->bif_ifp)) {
				in6_ifdetach(bif->bif_ifp);
				if_printf(sc->sc_ifp,
				    "IPv6 addresses on %s have been removed "