1 files changed, 231 insertions, 0 deletions
diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
new file mode 100644
index 000000000000..3d3f8fce10a5
--- /dev/null
+++ b/net/netfilter/nft_hash.c
@@ -0,0 +1,231 @@
+/*
+ * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Development of this code funded by Astaro AG (http://www.astaro.com/)
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/jhash.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+
+struct nft_hash {
+	struct hlist_head	*hash;
+	unsigned int		hsize;
+};
+
+struct nft_hash_elem {
+	struct hlist_node	hnode;
+	struct nft_data		key;
+	struct nft_data		data[];
+};
+
+static u32 nft_hash_rnd __read_mostly;
+static bool nft_hash_rnd_initted __read_mostly;
+
+static unsigned int nft_hash_data(const struct nft_data *data,
+				  unsigned int hsize, unsigned int len)
+{
+	unsigned int h;
+
+	h = jhash(data->data, len, nft_hash_rnd);
+	return ((u64)h * hsize) >> 32;
+}
+
+static bool nft_hash_lookup(const struct nft_set *set,
+			    const struct nft_data *key,
+			    struct nft_data *data)
+{
+	const struct nft_hash *priv = nft_set_priv(set);
+	const struct nft_hash_elem *he;
+	unsigned int h;
+
+	h = nft_hash_data(key, priv->hsize, set->klen);
+	hlist_for_each_entry(he, &priv->hash[h], hnode) {
+		if (nft_data_cmp(&he->key, key, set->klen))
+			continue;
+		if (set->flags & NFT_SET_MAP)
+			nft_data_copy(data, he->data);
+		return true;
+	}
+	return false;
+}
+
+static void nft_hash_elem_destroy(const struct nft_set *set,
+				  struct nft_hash_elem *he)
+{
+	nft_data_uninit(&he->key, NFT_DATA_VALUE);
+	if (set->flags & NFT_SET_MAP)
+		nft_data_uninit(he->data, set->dtype);
+	kfree(he);
+}
+
+static int nft_hash_insert(const struct nft_set *set,
+			   const struct nft_set_elem *elem)
+{
+	struct nft_hash *priv = nft_set_priv(set);
+	struct nft_hash_elem *he;
+	unsigned int size, h;
+
+	if (elem->flags != 0)
+		return -EINVAL;
+
+	size = sizeof(*he);
+	if (set->flags & NFT_SET_MAP)
+		size += sizeof(he->data[0]);
+
+	he = kzalloc(size, GFP_KERNEL);
+	if (he == NULL)
+		return -ENOMEM;
+
+	nft_data_copy(&he->key, &elem->key);
+	if (set->flags & NFT_SET_MAP)
+		nft_data_copy(he->data, &elem->data);
+
+	h = nft_hash_data(&he->key, priv->hsize, set->klen);
+	hlist_add_head_rcu(&he->hnode, &priv->hash[h]);
+	return 0;
+}
+
+static void nft_hash_remove(const struct nft_set *set,
+			    const struct nft_set_elem *elem)
+{
+	struct nft_hash_elem *he = elem->cookie;
+
+	hlist_del_rcu(&he->hnode);
+	kfree(he);
+}
+
+static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem)
+{
+	const struct nft_hash *priv = nft_set_priv(set);
+	struct nft_hash_elem *he;
+	unsigned int h;
+
+	h = nft_hash_data(&elem->key, priv->hsize, set->klen);
+	hlist_for_each_entry(he, &priv->hash[h], hnode) {
+		if (nft_data_cmp(&he->key, &elem->key, set->klen))
+			continue;
+
+		elem->cookie = he;
+		elem->flags  = 0;
+		if (set->flags & NFT_SET_MAP)
+			nft_data_copy(&elem->data, he->data);
+		return 0;
+	}
+	return -ENOENT;
+}
+
+static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
+			  struct nft_set_iter *iter)
+{
+	const struct nft_hash *priv = nft_set_priv(set);
+	const struct nft_hash_elem *he;
+	struct nft_set_elem elem;
+	unsigned int i;
+
+	for (i = 0; i < priv->hsize; i++) {
+		hlist_for_each_entry(he, &priv->hash[i], hnode) {
+			if (iter->count < iter->skip)
+				goto cont;
+
+			memcpy(&elem.key, &he->key, sizeof(elem.key));
+			if (set->flags & NFT_SET_MAP)
+				memcpy(&elem.data, he->data, sizeof(elem.data));
+			elem.flags = 0;
+
+			iter->err = iter->fn(ctx, set, iter, &elem);
+			if (iter->err < 0)
+				return;
+cont:
+			iter->count++;
+		}
+	}
+}
+
+static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
+{
+	return sizeof(struct nft_hash);
+}
+
+static int nft_hash_init(const struct nft_set *set,
+			 const struct nlattr * const tb[])
+{
+	struct nft_hash *priv = nft_set_priv(set);
+	unsigned int cnt, i;
+
+	if (unlikely(!nft_hash_rnd_initted)) {
+		get_random_bytes(&nft_hash_rnd, 4);
+		nft_hash_rnd_initted = true;
+	}
+
+	/* Aim for a load factor of 0.75 */
+	// FIXME: temporarily broken until we have set descriptions
+	cnt = 100;
+	cnt = cnt * 4 / 3;
+
+	priv->hash = kcalloc(cnt, sizeof(struct hlist_head), GFP_KERNEL);
+	if (priv->hash == NULL)
+		return -ENOMEM;
+	priv->hsize = cnt;
+
+	for (i = 0; i < cnt; i++)
+		INIT_HLIST_HEAD(&priv->hash[i]);
+
+	return 0;
+}
+
+static void nft_hash_destroy(const struct nft_set *set)
+{
+	const struct nft_hash *priv = nft_set_priv(set);
+	const struct hlist_node *next;
+	struct nft_hash_elem *elem;
+	unsigned int i;
+
+	for (i = 0; i < priv->hsize; i++) {
+		hlist_for_each_entry_safe(elem, next, &priv->hash[i], hnode) {
+			hlist_del(&elem->hnode);
+			nft_hash_elem_destroy(set, elem);
+		}
+	}
+	kfree(priv->hash);
+}
+
+static struct nft_set_ops nft_hash_ops __read_mostly = {
+	.privsize       = nft_hash_privsize,
+	.init		= nft_hash_init,
+	.destroy	= nft_hash_destroy,
+	.get		= nft_hash_get,
+	.insert		= nft_hash_insert,
+	.remove		= nft_hash_remove,
+	.lookup		= nft_hash_lookup,
+	.walk		= nft_hash_walk,
+	.features	= NFT_SET_MAP,
+	.owner		= THIS_MODULE,
+};
+
+static int __init nft_hash_module_init(void)
+{
+	return nft_register_set(&nft_hash_ops);
+}
+
+static void __exit nft_hash_module_exit(void)
+{
+	nft_unregister_set(&nft_hash_ops);
+}
+
+module_init(nft_hash_module_init);
+module_exit(nft_hash_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_ALIAS_NFT_SET();