netfilter: nf_tables: rename set implementations

Use nft_set_* prefix for backend set implementations, thus we can use
nft_hash for the new hash expression.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 395 insertions, 0 deletions

diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
new file mode 100644
index 000000000000..564fa7929ed5
--- /dev/null
+++ b/net/netfilter/nft_set_hash.c
@@ -0,0 +1,395 @@
+/*
+ * Copyright (c) 2008-2014 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/log2.h>
+#include <linux/jhash.h>
+#include <linux/netlink.h>
+#include <linux/workqueue.h>
+#include <linux/rhashtable.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+
+/* We target a hash table size of 4, element hint is 75% of final size */
+#define NFT_HASH_ELEMENT_HINT 3
+
+struct nft_hash {
+	struct rhashtable		ht;
+	struct delayed_work		gc_work;
+};
+
+struct nft_hash_elem {
+	struct rhash_head		node;
+	struct nft_set_ext		ext;
+};
+
+struct nft_hash_cmp_arg {
+	const struct nft_set		*set;
+	const u32			*key;
+	u8				genmask;
+};
+
+static const struct rhashtable_params nft_hash_params;
+
+static inline u32 nft_hash_key(const void *data, u32 len, u32 seed)
+{
+	const struct nft_hash_cmp_arg *arg = data;
+
+	return jhash(arg->key, len, seed);
+}
+
+static inline u32 nft_hash_obj(const void *data, u32 len, u32 seed)
+{
+	const struct nft_hash_elem *he = data;
+
+	return jhash(nft_set_ext_key(&he->ext), len, seed);
+}
+
+static inline int nft_hash_cmp(struct rhashtable_compare_arg *arg,
+			       const void *ptr)
+{
+	const struct nft_hash_cmp_arg *x = arg->key;
+	const struct nft_hash_elem *he = ptr;
+
+	if (memcmp(nft_set_ext_key(&he->ext), x->key, x->set->klen))
+		return 1;
+	if (nft_set_elem_expired(&he->ext))
+		return 1;
+	if (!nft_set_elem_active(&he->ext, x->genmask))
+		return 1;
+	return 0;
+}
+
+static bool nft_hash_lookup(const struct net *net, const struct nft_set *set,
+			    const u32 *key, const struct nft_set_ext **ext)
+{
+	struct nft_hash *priv = nft_set_priv(set);
+	const struct nft_hash_elem *he;
+	struct nft_hash_cmp_arg arg = {
+		.genmask = nft_genmask_cur(net),
+		.set	 = set,
+		.key	 = key,
+	};
+
+	he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
+	if (he != NULL)
+		*ext = &he->ext;
+
+	return !!he;
+}
+
+static bool nft_hash_update(struct nft_set *set, const u32 *key,
+			    void *(*new)(struct nft_set *,
+					 const struct nft_expr *,
+					 struct nft_regs *regs),
+			    const struct nft_expr *expr,
+			    struct nft_regs *regs,
+			    const struct nft_set_ext **ext)
+{
+	struct nft_hash *priv = nft_set_priv(set);
+	struct nft_hash_elem *he;
+	struct nft_hash_cmp_arg arg = {
+		.genmask = NFT_GENMASK_ANY,
+		.set	 = set,
+		.key	 = key,
+	};
+
+	he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
+	if (he != NULL)
+		goto out;
+
+	he = new(set, expr, regs);
+	if (he == NULL)
+		goto err1;
+	if (rhashtable_lookup_insert_key(&priv->ht, &arg, &he->node,
+					 nft_hash_params))
+		goto err2;
+out:
+	*ext = &he->ext;
+	return true;
+
+err2:
+	nft_set_elem_destroy(set, he);
+err1:
+	return false;
+}
+
+static int nft_hash_insert(const struct net *net, const struct nft_set *set,
+			   const struct nft_set_elem *elem)
+{
+	struct nft_hash *priv = nft_set_priv(set);
+	struct nft_hash_elem *he = elem->priv;
+	struct nft_hash_cmp_arg arg = {
+		.genmask = nft_genmask_next(net),
+		.set	 = set,
+		.key	 = elem->key.val.data,
+	};
+
+	return rhashtable_lookup_insert_key(&priv->ht, &arg, &he->node,
+					    nft_hash_params);
+}
+
+static void nft_hash_activate(const struct net *net, const struct nft_set *set,
+			      const struct nft_set_elem *elem)
+{
+	struct nft_hash_elem *he = elem->priv;
+
+	nft_set_elem_change_active(net, set, &he->ext);
+	nft_set_elem_clear_busy(&he->ext);
+}
+
+static void *nft_hash_deactivate(const struct net *net,
+				 const struct nft_set *set,
+				 const struct nft_set_elem *elem)
+{
+	struct nft_hash *priv = nft_set_priv(set);
+	struct nft_hash_elem *he;
+	struct nft_hash_cmp_arg arg = {
+		.genmask = nft_genmask_next(net),
+		.set	 = set,
+		.key	 = elem->key.val.data,
+	};
+
+	rcu_read_lock();
+	he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
+	if (he != NULL) {
+		if (!nft_set_elem_mark_busy(&he->ext) ||
+		    !nft_is_active(net, &he->ext))
+			nft_set_elem_change_active(net, set, &he->ext);
+		else
+			he = NULL;
+	}
+	rcu_read_unlock();
+
+	return he;
+}
+
+static void nft_hash_remove(const struct nft_set *set,
+			    const struct nft_set_elem *elem)
+{
+	struct nft_hash *priv = nft_set_priv(set);
+	struct nft_hash_elem *he = elem->priv;
+
+	rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
+}
+
+static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
+			  struct nft_set_iter *iter)
+{
+	struct nft_hash *priv = nft_set_priv(set);
+	struct nft_hash_elem *he;
+	struct rhashtable_iter hti;
+	struct nft_set_elem elem;
+	int err;
+
+	err = rhashtable_walk_init(&priv->ht, &hti, GFP_KERNEL);
+	iter->err = err;
+	if (err)
+		return;
+
+	err = rhashtable_walk_start(&hti);
+	if (err && err != -EAGAIN) {
+		iter->err = err;
+		goto out;
+	}
+
+	while ((he = rhashtable_walk_next(&hti))) {
+		if (IS_ERR(he)) {
+			err = PTR_ERR(he);
+			if (err != -EAGAIN) {
+				iter->err = err;
+				goto out;
+			}
+
+			continue;
+		}
+
+		if (iter->count < iter->skip)
+			goto cont;
+		if (nft_set_elem_expired(&he->ext))
+			goto cont;
+		if (!nft_set_elem_active(&he->ext, iter->genmask))
+			goto cont;
+
+		elem.priv = he;
+
+		iter->err = iter->fn(ctx, set, iter, &elem);
+		if (iter->err < 0)
+			goto out;
+
+cont:
+		iter->count++;
+	}
+
+out:
+	rhashtable_walk_stop(&hti);
+	rhashtable_walk_exit(&hti);
+}
+
+static void nft_hash_gc(struct work_struct *work)
+{
+	struct nft_set *set;
+	struct nft_hash_elem *he;
+	struct nft_hash *priv;
+	struct nft_set_gc_batch *gcb = NULL;
+	struct rhashtable_iter hti;
+	int err;
+
+	priv = container_of(work, struct nft_hash, gc_work.work);
+	set  = nft_set_container_of(priv);
+
+	err = rhashtable_walk_init(&priv->ht, &hti, GFP_KERNEL);
+	if (err)
+		goto schedule;
+
+	err = rhashtable_walk_start(&hti);
+	if (err && err != -EAGAIN)
+		goto out;
+
+	while ((he = rhashtable_walk_next(&hti))) {
+		if (IS_ERR(he)) {
+			if (PTR_ERR(he) != -EAGAIN)
+				goto out;
+			continue;
+		}
+
+		if (!nft_set_elem_expired(&he->ext))
+			continue;
+		if (nft_set_elem_mark_busy(&he->ext))
+			continue;
+
+		gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
+		if (gcb == NULL)
+			goto out;
+		rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
+		atomic_dec(&set->nelems);
+		nft_set_gc_batch_add(gcb, he);
+	}
+out:
+	rhashtable_walk_stop(&hti);
+	rhashtable_walk_exit(&hti);
+
+	nft_set_gc_batch_complete(gcb);
+schedule:
+	queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
+			   nft_set_gc_interval(set));
+}
+
+static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
+{
+	return sizeof(struct nft_hash);
+}
+
+static const struct rhashtable_params nft_hash_params = {
+	.head_offset		= offsetof(struct nft_hash_elem, node),
+	.hashfn			= nft_hash_key,
+	.obj_hashfn		= nft_hash_obj,
+	.obj_cmpfn		= nft_hash_cmp,
+	.automatic_shrinking	= true,
+};
+
+static int nft_hash_init(const struct nft_set *set,
+			 const struct nft_set_desc *desc,
+			 const struct nlattr * const tb[])
+{
+	struct nft_hash *priv = nft_set_priv(set);
+	struct rhashtable_params params = nft_hash_params;
+	int err;
+
+	params.nelem_hint = desc->size ?: NFT_HASH_ELEMENT_HINT;
+	params.key_len	  = set->klen;
+
+	err = rhashtable_init(&priv->ht, &params);
+	if (err < 0)
+		return err;
+
+	INIT_DEFERRABLE_WORK(&priv->gc_work, nft_hash_gc);
+	if (set->flags & NFT_SET_TIMEOUT)
+		queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
+				   nft_set_gc_interval(set));
+	return 0;
+}
+
+static void nft_hash_elem_destroy(void *ptr, void *arg)
+{
+	nft_set_elem_destroy((const struct nft_set *)arg, ptr);
+}
+
+static void nft_hash_destroy(const struct nft_set *set)
+{
+	struct nft_hash *priv = nft_set_priv(set);
+
+	cancel_delayed_work_sync(&priv->gc_work);
+	rhashtable_free_and_destroy(&priv->ht, nft_hash_elem_destroy,
+				    (void *)set);
+}
+
+static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
+			      struct nft_set_estimate *est)
+{
+	unsigned int esize;
+
+	esize = sizeof(struct nft_hash_elem);
+	if (desc->size) {
+		est->size = sizeof(struct nft_hash) +
+			    roundup_pow_of_two(desc->size * 4 / 3) *
+			    sizeof(struct nft_hash_elem *) +
+			    desc->size * esize;
+	} else {
+		/* Resizing happens when the load drops below 30% or goes
+		 * above 75%. The average of 52.5% load (approximated by 50%)
+		 * is used for the size estimation of the hash buckets,
+		 * meaning we calculate two buckets per element.
+		 */
+		est->size = esize + 2 * sizeof(struct nft_hash_elem *);
+	}
+
+	est->class = NFT_SET_CLASS_O_1;
+
+	return true;
+}
+
+static struct nft_set_ops nft_hash_ops __read_mostly = {
+	.privsize       = nft_hash_privsize,
+	.elemsize	= offsetof(struct nft_hash_elem, ext),
+	.estimate	= nft_hash_estimate,
+	.init		= nft_hash_init,
+	.destroy	= nft_hash_destroy,
+	.insert		= nft_hash_insert,
+	.activate	= nft_hash_activate,
+	.deactivate	= nft_hash_deactivate,
+	.remove		= nft_hash_remove,
+	.lookup		= nft_hash_lookup,
+	.update		= nft_hash_update,
+	.walk		= nft_hash_walk,
+	.features	= NFT_SET_MAP | NFT_SET_TIMEOUT,
+	.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();