int ip_defrag(struct sk_buff *skb, u32 user)
{
	struct ipq *qp;
	struct net *net;

	net = skb->dev ? dev_net(skb->dev) : dev_net(skb_dst(skb)->dev);
	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS);

	/* Start by cleaning up the memory. */
	if (atomic_read(&net->ipv4.frags.mem) > net->ipv4.frags.high_thresh)
		ip_evictor(net);

	/* Lookup (or create) queue header */
	if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) {
		int ret;

		spin_lock(&qp->q.lock);

		ret = ip_frag_queue(qp, skb);

		spin_unlock(&qp->q.lock);
		ipq_put(qp);
		return ret;
	}

	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
	kfree_skb(skb);
	return -ENOMEM;
}

Unknown