+ /*
+ * Purge or update corresponding prefix
+ *
+ * 1) we don't purge prefix here if address was not permanent.
+ * prefix is managed by its own lifetime.
+ * 2) if there're no addresses, delete prefix.
+ * 3) if there're still other permanent address(es),
+ * corresponding prefix is still permanent.
+ * 4) otherwise, update prefix lifetime to the
+ * longest valid lifetime among the corresponding
+ * addresses on the device.
+ * Note: subsequent RA will update lifetime.
+ *
+ * --yoshfuji
+ */
+ if ((ifp->flags & IFA_F_PERMANENT) && onlink < 1) {
+ struct in6_addr prefix;
+ struct rt6_info *rt;
+
+ ipv6_addr_prefix(&prefix, &ifp->addr, ifp->prefix_len);
+ rt = rt6_lookup(&prefix, NULL, ifp->idev->dev->ifindex, 1);
+
+ if (rt && ((rt->rt6i_flags & (RTF_GATEWAY | RTF_DEFAULT)) == 0)) {
+ if (onlink == 0) {
+ ip6_del_rt(rt, NULL, NULL);
+ rt = NULL;
+ } else if (!(rt->rt6i_flags & RTF_EXPIRES)) {
+ rt->rt6i_expires = expires;
+ rt->rt6i_flags |= RTF_EXPIRES;
+ }
+ }
+ dst_release(&rt->u.dst);
+ }
+