static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
			    struct nl_info *info)
{
	struct rt6_info *iter = NULL;
	struct rt6_info **ins;
	int replace = (info->nlh &&
		       (info->nlh->nlmsg_flags & NLM_F_REPLACE));
	int add = (!info->nlh ||
		   (info->nlh->nlmsg_flags & NLM_F_CREATE));
	int found = 0;

	ins = &fn->leaf;

	for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) {
		/*
		 *	Search for duplicates
		 */

		if (iter->rt6i_metric == rt->rt6i_metric) {
			/*
			 *	Same priority level
			 */
			if (info->nlh &&
			    (info->nlh->nlmsg_flags & NLM_F_EXCL))
				return -EEXIST;
			if (replace) {
				found++;
				break;
			}

			if (iter->dst.dev == rt->dst.dev &&
			    iter->rt6i_idev == rt->rt6i_idev &&
			    ipv6_addr_equal(&iter->rt6i_gateway,
					    &rt->rt6i_gateway)) {
				if (!(iter->rt6i_flags & RTF_EXPIRES))
					return -EEXIST;
				if (!(rt->rt6i_flags & RTF_EXPIRES))
					rt6_clean_expires(iter);
				else
					rt6_set_expires(iter, rt->dst.expires);
				return -EEXIST;
			}
		}

		if (iter->rt6i_metric > rt->rt6i_metric)
			break;

		ins = &iter->dst.rt6_next;
	}

	/* Reset round-robin state, if necessary */
	if (ins == &fn->leaf)
		fn->rr_ptr = NULL;

	/*
	 *	insert node
	 */
	if (!replace) {
		if (!add)
			pr_warn("NLM_F_CREATE should be set when creating new route\n");

add:
		rt->dst.rt6_next = iter;
		*ins = rt;
		rt->rt6i_node = fn;
		atomic_inc(&rt->rt6i_ref);
		inet6_rt_notify(RTM_NEWROUTE, rt, info);
		info->nl_net->ipv6.rt6_stats->fib_rt_entries++;

		if (!(fn->fn_flags & RTN_RTINFO)) {
			info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
			fn->fn_flags |= RTN_RTINFO;
		}

	} else {
		if (!found) {
			if (add)
				goto add;
			pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
			return -ENOENT;
		}
		*ins = rt;
		rt->rt6i_node = fn;
		rt->dst.rt6_next = iter->dst.rt6_next;
		atomic_inc(&rt->rt6i_ref);
		inet6_rt_notify(RTM_NEWROUTE, rt, info);
		rt6_release(iter);
		if (!(fn->fn_flags & RTN_RTINFO)) {
			info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
			fn->fn_flags |= RTN_RTINFO;
		}
	}

	return 0;
}
Unknown