[mirror_ubuntu-artful-kernel.git] / net / netfilter / nft_set_hash.c

/*
 * 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, *prev;
	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;

	prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node,
						nft_hash_params);
	if (IS_ERR(prev))
		goto err2;

	/* Another cpu may race to insert the element with the same key */
	if (prev) {
		nft_set_elem_destroy(set, he, true);
		he = prev;
	}

out:
	*ext = &he->ext;
	return true;

err2:
	nft_set_elem_destroy(set, he, true);
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_set_ext **ext)
{
	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,
	};
	struct nft_hash_elem *prev;

	prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node,
					       nft_hash_params);
	if (IS_ERR(prev))
		return PTR_ERR(prev);
	if (prev) {
		*ext = &prev->ext;
		return -EEXIST;
	}
	return 0;
}

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 bool nft_hash_flush(const struct net *net,
			   const struct nft_set *set, void *priv)
{
	struct nft_hash_elem *he = priv;

	if (!nft_set_elem_mark_busy(&he->ext) ||
	    !nft_is_active(net, &he->ext)) {
		nft_set_elem_change_active(net, set, &he->ext);
		return true;
	}
	return false;
}

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 &&
	    !nft_hash_flush(net, set, he))
		he = NULL;

	rcu_read_unlock();

	return he;
}

static void nft_hash_remove(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;

	rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
}

static void nft_hash_walk(const struct nft_ctx *ctx, 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, true);
}

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,
	.flush		= nft_hash_flush,
	.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();
Commit	Line	Data
96518518	1	/*
ce6eb0d7	2	* Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
96518518 PM	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*
	8	* Development of this code funded by Astaro AG (http://www.astaro.com/)
	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/init.h>
	13	#include <linux/module.h>
	14	#include <linux/list.h>
c50b960c	15	#include <linux/log2.h>
96518518 PM	16	#include <linux/jhash.h>
96518518 PM	17	#include <linux/netlink.h>
9d098292	18	#include <linux/workqueue.h>
cfe4a9dd	19	#include <linux/rhashtable.h>
96518518 PM	20	#include <linux/netfilter.h>
	21	#include <linux/netfilter/nf_tables.h>
	22	#include <net/netfilter/nf_tables.h>
	23
cfe4a9dd TG	24	/* We target a hash table size of 4, element hint is 75% of final size */
cfe4a9dd TG	25	#define NFT_HASH_ELEMENT_HINT 3
96518518	26
745f5450 PM	27	struct nft_hash {
745f5450 PM	28	struct rhashtable ht;
9d098292	29	struct delayed_work gc_work;
745f5450 PM	30	};
745f5450 PM	31
96518518	32	struct nft_hash_elem {
cfe4a9dd	33	struct rhash_head node;
fe2811eb	34	struct nft_set_ext ext;
96518518 PM	35	};
96518518 PM	36
bfd6e327 PM	37	struct nft_hash_cmp_arg {
bfd6e327 PM	38	const struct nft_set *set;
8cd8937a	39	const u32 *key;
cc02e457	40	u8 genmask;
bfd6e327 PM	41	};
bfd6e327 PM	42
fa377321 HX	43	static const struct rhashtable_params nft_hash_params;
fa377321 HX	44
bfd6e327 PM	45	static inline u32 nft_hash_key(const void *data, u32 len, u32 seed)
	46	{
	47	const struct nft_hash_cmp_arg *arg = data;
	48
	49	return jhash(arg->key, len, seed);
	50	}
	51
	52	static inline u32 nft_hash_obj(const void *data, u32 len, u32 seed)
	53	{
	54	const struct nft_hash_elem *he = data;
	55
fe2811eb	56	return jhash(nft_set_ext_key(&he->ext), len, seed);
bfd6e327 PM	57	}
	58
	59	static inline int nft_hash_cmp(struct rhashtable_compare_arg *arg,
	60	const void *ptr)
	61	{
	62	const struct nft_hash_cmp_arg *x = arg->key;
	63	const struct nft_hash_elem *he = ptr;
	64
e562d860	65	if (memcmp(nft_set_ext_key(&he->ext), x->key, x->set->klen))
bfd6e327	66	return 1;
9d098292 PM	67	if (nft_set_elem_expired(&he->ext))
9d098292 PM	68	return 1;
cc02e457 PM	69	if (!nft_set_elem_active(&he->ext, x->genmask))
cc02e457 PM	70	return 1;
bfd6e327 PM	71	return 0;
	72	}
	73
42a55769 PNA	74	static bool nft_hash_lookup(const struct net net, const struct nft_set set,
42a55769 PNA	75	const u32 key, const struct nft_set_ext *ext)
96518518	76	{
745f5450	77	struct nft_hash *priv = nft_set_priv(set);
20a69341	78	const struct nft_hash_elem *he;
bfd6e327	79	struct nft_hash_cmp_arg arg = {
42a55769	80	.genmask = nft_genmask_cur(net),
bfd6e327 PM	81	.set = set,
	82	.key = key,
	83	};
ce6eb0d7	84
bfd6e327	85	he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
b2832dd6 PM	86	if (he != NULL)
b2832dd6 PM	87	*ext = &he->ext;
ce6eb0d7	88
cfe4a9dd	89	return !!he;
96518518 PM	90	}
96518518 PM	91
8cd8937a	92	static bool nft_hash_update(struct nft_set set, const u32 key,
22fe54d5 PM	93	void (new)(struct nft_set *,
22fe54d5 PM	94	const struct nft_expr *,
a55e22e9	95	struct nft_regs *regs),
22fe54d5	96	const struct nft_expr *expr,
a55e22e9	97	struct nft_regs *regs,
22fe54d5 PM	98	const struct nft_set_ext **ext)
	99	{
	100	struct nft_hash *priv = nft_set_priv(set);
dab45060	101	struct nft_hash_elem he, prev;
22fe54d5 PM	102	struct nft_hash_cmp_arg arg = {
	103	.genmask = NFT_GENMASK_ANY,
	104	.set = set,
	105	.key = key,
	106	};
	107
	108	he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
	109	if (he != NULL)
	110	goto out;
	111
a55e22e9	112	he = new(set, expr, regs);
22fe54d5 PM	113	if (he == NULL)
22fe54d5 PM	114	goto err1;
dab45060 LZ	115
	116	prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node,
	117	nft_hash_params);
	118	if (IS_ERR(prev))
22fe54d5	119	goto err2;
dab45060 LZ	120
	121	/* Another cpu may race to insert the element with the same key */
	122	if (prev) {
	123	nft_set_elem_destroy(set, he, true);
	124	he = prev;
	125	}
	126
22fe54d5 PM	127	out:
	128	*ext = &he->ext;
	129	return true;
	130
	131	err2:
61f9e292	132	nft_set_elem_destroy(set, he, true);
22fe54d5 PM	133	err1:
	134	return false;
	135	}
	136
42a55769	137	static int nft_hash_insert(const struct net net, const struct nft_set set,
c016c7e4 PNA	138	const struct nft_set_elem *elem,
c016c7e4 PNA	139	struct nft_set_ext **ext)
96518518	140	{
745f5450	141	struct nft_hash *priv = nft_set_priv(set);
fe2811eb	142	struct nft_hash_elem *he = elem->priv;
bfd6e327	143	struct nft_hash_cmp_arg arg = {
42a55769	144	.genmask = nft_genmask_next(net),
bfd6e327	145	.set = set,
7d740264	146	.key = elem->key.val.data,
bfd6e327	147	};
c016c7e4 PNA	148	struct nft_hash_elem *prev;
	149
	150	prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node,
	151	nft_hash_params);
	152	if (IS_ERR(prev))
	153	return PTR_ERR(prev);
	154	if (prev) {
	155	*ext = &prev->ext;
	156	return -EEXIST;
	157	}
	158	return 0;
96518518 PM	159	}
96518518 PM	160
42a55769	161	static void nft_hash_activate(const struct net net, const struct nft_set set,
cc02e457	162	const struct nft_set_elem *elem)
96518518	163	{
cc02e457	164	struct nft_hash_elem *he = elem->priv;
ce6eb0d7	165
42a55769	166	nft_set_elem_change_active(net, set, &he->ext);
9d098292	167	nft_set_elem_clear_busy(&he->ext);
20a69341	168	}
96518518	169
1ba1c414 PNA	170	static bool nft_hash_flush(const struct net *net,
1ba1c414 PNA	171	const struct nft_set set, void priv)
37df5301 PNA	172	{
	173	struct nft_hash_elem *he = priv;
	174
	175	if (!nft_set_elem_mark_busy(&he->ext) \|\|
	176	!nft_is_active(net, &he->ext)) {
	177	nft_set_elem_change_active(net, set, &he->ext);
	178	return true;
	179	}
	180	return false;
	181	}
	182
42a55769 PNA	183	static void nft_hash_deactivate(const struct net net,
42a55769 PNA	184	const struct nft_set *set,
cc02e457	185	const struct nft_set_elem *elem)
20a69341	186	{
745f5450	187	struct nft_hash *priv = nft_set_priv(set);
fa377321	188	struct nft_hash_elem *he;
bfd6e327	189	struct nft_hash_cmp_arg arg = {
8eee54be	190	.genmask = nft_genmask_next(net),
bfd6e327	191	.set = set,
7d740264	192	.key = elem->key.val.data,
bfd6e327	193	};
fa377321	194
9d098292	195	rcu_read_lock();
bfd6e327	196	he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
37df5301	197	if (he != NULL &&
1ba1c414	198	!nft_hash_flush(net, set, he))
37df5301 PNA	199	he = NULL;
37df5301 PNA	200
9d098292	201	rcu_read_unlock();
8d24c0b4	202
cc02e457 PM	203	return he;
cc02e457 PM	204	}
8d24c0b4	205
5cb82a38 PNA	206	static void nft_hash_remove(const struct net *net,
5cb82a38 PNA	207	const struct nft_set *set,
cc02e457 PM	208	const struct nft_set_elem *elem)
	209	{
	210	struct nft_hash *priv = nft_set_priv(set);
	211	struct nft_hash_elem *he = elem->priv;
	212
	213	rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
96518518 PM	214	}
96518518 PM	215
de70185d	216	static void nft_hash_walk(const struct nft_ctx ctx, struct nft_set set,
20a69341	217	struct nft_set_iter *iter)
96518518	218	{
745f5450	219	struct nft_hash *priv = nft_set_priv(set);
fe2811eb	220	struct nft_hash_elem *he;
9a776628	221	struct rhashtable_iter hti;
20a69341	222	struct nft_set_elem elem;
9a776628	223	int err;
96518518	224
8f6fd83c	225	err = rhashtable_walk_init(&priv->ht, &hti, GFP_KERNEL);
9a776628 HX	226	iter->err = err;
	227	if (err)
	228	return;
88d6ed15	229
9a776628 HX	230	err = rhashtable_walk_start(&hti);
	231	if (err && err != -EAGAIN) {
	232	iter->err = err;
	233	goto out;
	234	}
	235
	236	while ((he = rhashtable_walk_next(&hti))) {
	237	if (IS_ERR(he)) {
	238	err = PTR_ERR(he);
	239	if (err != -EAGAIN) {
	240	iter->err = err;
	241	goto out;
	242	}
d8bdff59 HX	243
d8bdff59 HX	244	continue;
9a776628 HX	245	}
	246
	247	if (iter->count < iter->skip)
	248	goto cont;
9d098292 PM	249	if (nft_set_elem_expired(&he->ext))
9d098292 PM	250	goto cont;
8588ac09	251	if (!nft_set_elem_active(&he->ext, iter->genmask))
cc02e457	252	goto cont;
20a69341	253
fe2811eb	254	elem.priv = he;
9a776628 HX	255
	256	iter->err = iter->fn(ctx, set, iter, &elem);
	257	if (iter->err < 0)
	258	goto out;
20a69341	259
20a69341	260	cont:
9a776628	261	iter->count++;
96518518	262	}
9a776628 HX	263
	264	out:
	265	rhashtable_walk_stop(&hti);
	266	rhashtable_walk_exit(&hti);
96518518 PM	267	}
96518518 PM	268
9d098292 PM	269	static void nft_hash_gc(struct work_struct *work)
9d098292 PM	270	{
3dd0673a	271	struct nft_set *set;
9d098292 PM	272	struct nft_hash_elem *he;
	273	struct nft_hash *priv;
	274	struct nft_set_gc_batch *gcb = NULL;
	275	struct rhashtable_iter hti;
	276	int err;
	277
	278	priv = container_of(work, struct nft_hash, gc_work.work);
	279	set = nft_set_container_of(priv);
	280
8f6fd83c	281	err = rhashtable_walk_init(&priv->ht, &hti, GFP_KERNEL);
9d098292 PM	282	if (err)
	283	goto schedule;
	284
	285	err = rhashtable_walk_start(&hti);
	286	if (err && err != -EAGAIN)
	287	goto out;
	288
	289	while ((he = rhashtable_walk_next(&hti))) {
	290	if (IS_ERR(he)) {
	291	if (PTR_ERR(he) != -EAGAIN)
	292	goto out;
	293	continue;
	294	}
	295
	296	if (!nft_set_elem_expired(&he->ext))
	297	continue;
	298	if (nft_set_elem_mark_busy(&he->ext))
	299	continue;
	300
	301	gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
	302	if (gcb == NULL)
	303	goto out;
	304	rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
3dd0673a	305	atomic_dec(&set->nelems);
9d098292 PM	306	nft_set_gc_batch_add(gcb, he);
	307	}
	308	out:
	309	rhashtable_walk_stop(&hti);
	310	rhashtable_walk_exit(&hti);
	311
	312	nft_set_gc_batch_complete(gcb);
	313	schedule:
	314	queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
	315	nft_set_gc_interval(set));
	316	}
	317
20a69341 PM	318	static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
20a69341 PM	319	{
745f5450	320	return sizeof(struct nft_hash);
cfe4a9dd TG	321	}
cfe4a9dd TG	322
fa377321	323	static const struct rhashtable_params nft_hash_params = {
45d84751	324	.head_offset = offsetof(struct nft_hash_elem, node),
bfd6e327 PM	325	.hashfn = nft_hash_key,
	326	.obj_hashfn = nft_hash_obj,
	327	.obj_cmpfn = nft_hash_cmp,
45d84751	328	.automatic_shrinking = true,
fa377321 HX	329	};
fa377321 HX	330
20a69341	331	static int nft_hash_init(const struct nft_set *set,
c50b960c	332	const struct nft_set_desc *desc,
96518518 PM	333	const struct nlattr * const tb[])
96518518 PM	334	{
745f5450	335	struct nft_hash *priv = nft_set_priv(set);
fa377321	336	struct rhashtable_params params = nft_hash_params;
9d098292	337	int err;
fa377321 HX	338
fa377321 HX	339	params.nelem_hint = desc->size ?: NFT_HASH_ELEMENT_HINT;
45d84751	340	params.key_len = set->klen;
96518518	341
9d098292 PM	342	err = rhashtable_init(&priv->ht, &params);
	343	if (err < 0)
	344	return err;
	345
	346	INIT_DEFERRABLE_WORK(&priv->gc_work, nft_hash_gc);
	347	if (set->flags & NFT_SET_TIMEOUT)
	348	queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
	349	nft_set_gc_interval(set));
	350	return 0;
96518518 PM	351	}
96518518 PM	352
61edafbb	353	static void nft_hash_elem_destroy(void ptr, void arg)
96518518	354	{
61f9e292	355	nft_set_elem_destroy((const struct nft_set *)arg, ptr, true);
6b6f302c	356	}
97defe1e	357
6b6f302c TG	358	static void nft_hash_destroy(const struct nft_set *set)
6b6f302c TG	359	{
745f5450 PM	360	struct nft_hash *priv = nft_set_priv(set);
745f5450 PM	361
9d098292	362	cancel_delayed_work_sync(&priv->gc_work);
61edafbb PM	363	rhashtable_free_and_destroy(&priv->ht, nft_hash_elem_destroy,
61edafbb PM	364	(void *)set);
96518518 PM	365	}
96518518 PM	366
c50b960c PM	367	static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
	368	struct nft_set_estimate *est)
	369	{
	370	unsigned int esize;
	371
	372	esize = sizeof(struct nft_hash_elem);
c50b960c	373	if (desc->size) {
745f5450	374	est->size = sizeof(struct nft_hash) +
cfe4a9dd	375	roundup_pow_of_two(desc->size * 4 / 3) *
c50b960c PM	376	sizeof(struct nft_hash_elem *) +
	377	desc->size * esize;
	378	} else {
	379	/* Resizing happens when the load drops below 30% or goes
	380	* above 75%. The average of 52.5% load (approximated by 50%)
	381	* is used for the size estimation of the hash buckets,
	382	* meaning we calculate two buckets per element.
	383	*/
	384	est->size = esize + 2 * sizeof(struct nft_hash_elem *);
	385	}
	386
	387	est->class = NFT_SET_CLASS_O_1;
	388
	389	return true;
	390	}
	391
20a69341 PM	392	static struct nft_set_ops nft_hash_ops __read_mostly = {
20a69341 PM	393	.privsize = nft_hash_privsize,
fe2811eb	394	.elemsize = offsetof(struct nft_hash_elem, ext),
c50b960c	395	.estimate = nft_hash_estimate,
96518518 PM	396	.init = nft_hash_init,
96518518 PM	397	.destroy = nft_hash_destroy,
20a69341	398	.insert = nft_hash_insert,
cc02e457 PM	399	.activate = nft_hash_activate,
cc02e457 PM	400	.deactivate = nft_hash_deactivate,
1ba1c414	401	.flush = nft_hash_flush,
20a69341 PM	402	.remove = nft_hash_remove,
20a69341 PM	403	.lookup = nft_hash_lookup,
22fe54d5	404	.update = nft_hash_update,
20a69341	405	.walk = nft_hash_walk,
9d098292	406	.features = NFT_SET_MAP \| NFT_SET_TIMEOUT,
20a69341	407	.owner = THIS_MODULE,
96518518 PM	408	};
	409
	410	static int __init nft_hash_module_init(void)
	411	{
20a69341	412	return nft_register_set(&nft_hash_ops);
96518518 PM	413	}
	414
	415	static void __exit nft_hash_module_exit(void)
	416	{
20a69341	417	nft_unregister_set(&nft_hash_ops);
96518518 PM	418	}
	419
	420	module_init(nft_hash_module_init);
	421	module_exit(nft_hash_module_exit);
	422
	423	MODULE_LICENSE("GPL");
	424	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
20a69341	425	MODULE_ALIAS_NFT_SET();