+#ifdef CONFIG_IPV6_ROUTE_INFO
+int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
+ struct in6_addr *gwaddr)
+{
+ struct route_info *rinfo = (struct route_info *) opt;
+ struct in6_addr prefix_buf, *prefix;
+ unsigned int pref;
+ u32 lifetime;
+ struct rt6_info *rt;
+
+ if (len < sizeof(struct route_info)) {
+ return -EINVAL;
+ }
+
+ /* Sanity check for prefix_len and length */
+ if (rinfo->length > 3) {
+ return -EINVAL;
+ } else if (rinfo->prefix_len > 128) {
+ return -EINVAL;
+ } else if (rinfo->prefix_len > 64) {
+ if (rinfo->length < 2) {
+ return -EINVAL;
+ }
+ } else if (rinfo->prefix_len > 0) {
+ if (rinfo->length < 1) {
+ return -EINVAL;
+ }
+ }
+
+ pref = rinfo->route_pref;
+ if (pref == ICMPV6_ROUTER_PREF_INVALID)
+ pref = ICMPV6_ROUTER_PREF_MEDIUM;
+
+ lifetime = htonl(rinfo->lifetime);
+ if (lifetime == 0xffffffff) {
+ /* infinity */
+ } else if (lifetime > 0x7fffffff/HZ) {
+ /* Avoid arithmetic overflow */
+ lifetime = 0x7fffffff/HZ - 1;
+ }
+
+ if (rinfo->length == 3)
+ prefix = (struct in6_addr *)rinfo->prefix;
+ else {
+ /* this function is safe */
+ ipv6_addr_prefix(&prefix_buf,
+ (struct in6_addr *)rinfo->prefix,
+ rinfo->prefix_len);
+ prefix = &prefix_buf;
+ }
+
+ rt = rt6_get_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex);
+
+ if (rt && !lifetime) {
+ ip6_del_rt(rt, NULL, NULL, NULL);
+ rt = NULL;
+ }
+
+ if (!rt && lifetime)
+ rt = rt6_add_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex,
+ pref);
+ else if (rt)
+ rt->rt6i_flags = RTF_ROUTEINFO |
+ (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
+
+ if (rt) {
+ if (lifetime == 0xffffffff) {
+ rt->rt6i_flags &= ~RTF_EXPIRES;
+ } else {
+ rt->rt6i_expires = jiffies + HZ * lifetime;
+ rt->rt6i_flags |= RTF_EXPIRES;
+ }
+ dst_release(&rt->u.dst);
+ }
+ return 0;
+}
+#endif
+