xref: /Linux-v6.1/net/netfilter/ipset/ip_set_hash_gen.h

/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (C) 2013 Jozsef Kadlecsik <kadlec@netfilter.org> */

#ifndef _IP_SET_HASH_GEN_H
#define _IP_SET_HASH_GEN_H

#include <linux/rcupdate.h>
#include <linux/jhash.h>
#include <linux/types.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/ipset/ip_set.h>

#define __ipset_dereference(p)		\
	rcu_dereference_protected(p, 1)
#define ipset_dereference_nfnl(p)	\
	rcu_dereference_protected(p,	\
		lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET))
#define ipset_dereference_set(p, set) 	\
	rcu_dereference_protected(p,	\
		lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET) || \
		lockdep_is_held(&(set)->lock))
#define ipset_dereference_bh_nfnl(p)	\
	rcu_dereference_bh_check(p, 	\
		lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET))

/* Hashing which uses arrays to resolve clashing. The hash table is resized
 * (doubled) when searching becomes too long.
 * Internally jhash is used with the assumption that the size of the
 * stored data is a multiple of sizeof(u32).
 *
 * Readers and resizing
 *
 * Resizing can be triggered by userspace command only, and those
 * are serialized by the nfnl mutex. During resizing the set is
 * read-locked, so the only possible concurrent operations are
 * the kernel side readers. Those must be protected by proper RCU locking.
 */

/* Number of elements to store in an initial array block */
#define AHASH_INIT_SIZE			2
/* Max number of elements to store in an array block */
#define AHASH_MAX_SIZE			(6 * AHASH_INIT_SIZE)
/* Max muber of elements in the array block when tuned */
#define AHASH_MAX_TUNED			64
#define AHASH_MAX(h)			((h)->bucketsize)

/* A hash bucket */
struct hbucket {
	struct rcu_head rcu;	/* for call_rcu */
	/* Which positions are used in the array */
	DECLARE_BITMAP(used, AHASH_MAX_TUNED);
	u8 size;		/* size of the array */
	u8 pos;			/* position of the first free entry */
	unsigned char value[]	/* the array of the values */
		__aligned(__alignof__(u64));
};

/* Region size for locking == 2^HTABLE_REGION_BITS */
#define HTABLE_REGION_BITS	10
#define ahash_numof_locks(htable_bits)		\
	((htable_bits) < HTABLE_REGION_BITS ? 1	\
		: jhash_size((htable_bits) - HTABLE_REGION_BITS))
#define ahash_sizeof_regions(htable_bits)		\
	(ahash_numof_locks(htable_bits) * sizeof(struct ip_set_region))
#define ahash_region(n, htable_bits)		\
	((n) % ahash_numof_locks(htable_bits))
#define ahash_bucket_start(h,  htable_bits)	\
	((htable_bits) < HTABLE_REGION_BITS ? 0	\
		: (h) * jhash_size(HTABLE_REGION_BITS))
#define ahash_bucket_end(h,  htable_bits)	\
	((htable_bits) < HTABLE_REGION_BITS ? jhash_size(htable_bits)	\
		: ((h) + 1) * jhash_size(HTABLE_REGION_BITS))

struct htable_gc {
	struct delayed_work dwork;
	struct ip_set *set;	/* Set the gc belongs to */
	u32 region;		/* Last gc run position */
};

/* The hash table: the table size stored here in order to make resizing easy */
struct htable {
	atomic_t ref;		/* References for resizing */
	atomic_t uref;		/* References for dumping and gc */
	u8 htable_bits;		/* size of hash table == 2^htable_bits */
	u32 maxelem;		/* Maxelem per region */
	struct ip_set_region *hregion;	/* Region locks and ext sizes */
	struct hbucket __rcu *bucket[]; /* hashtable buckets */
};

#define hbucket(h, i)		((h)->bucket[i])
#define ext_size(n, dsize)	\
	(sizeof(struct hbucket) + (n) * (dsize))

#ifndef IPSET_NET_COUNT
#define IPSET_NET_COUNT		1
#endif

/* Book-keeping of the prefixes added to the set */
struct net_prefixes {
	u32 nets[IPSET_NET_COUNT]; /* number of elements for this cidr */
	u8 cidr[IPSET_NET_COUNT];  /* the cidr value */
};

/* Compute the hash table size */
static size_t
htable_size(u8 hbits)
{
	size_t hsize;

	/* We must fit both into u32 in jhash and INT_MAX in kvmalloc_node() */
	if (hbits > 31)
		return 0;
	hsize = jhash_size(hbits);
	if ((INT_MAX - sizeof(struct htable)) / sizeof(struct hbucket *)
	    < hsize)
		return 0;

	return hsize * sizeof(struct hbucket *) + sizeof(struct htable);
}

#ifdef IP_SET_HASH_WITH_NETS
#if IPSET_NET_COUNT > 1
#define __CIDR(cidr, i)		(cidr[i])
#else
#define __CIDR(cidr, i)		(cidr)
#endif

/* cidr + 1 is stored in net_prefixes to support /0 */
#define NCIDR_PUT(cidr)		((cidr) + 1)
#define NCIDR_GET(cidr)		((cidr) - 1)

#ifdef IP_SET_HASH_WITH_NETS_PACKED
/* When cidr is packed with nomatch, cidr - 1 is stored in the data entry */
#define DCIDR_PUT(cidr)		((cidr) - 1)
#define DCIDR_GET(cidr, i)	(__CIDR(cidr, i) + 1)
#else
#define DCIDR_PUT(cidr)		(cidr)
#define DCIDR_GET(cidr, i)	__CIDR(cidr, i)
#endif

#define INIT_CIDR(cidr, host_mask)	\
	DCIDR_PUT(((cidr) ? NCIDR_GET(cidr) : host_mask))

#ifdef IP_SET_HASH_WITH_NET0
/* cidr from 0 to HOST_MASK value and c = cidr + 1 */
#define NLEN			(HOST_MASK + 1)
#define CIDR_POS(c)		((c) - 1)
#else
/* cidr from 1 to HOST_MASK value and c = cidr + 1 */
#define NLEN			HOST_MASK
#define CIDR_POS(c)		((c) - 2)
#endif

#else
#define NLEN			0
#endif /* IP_SET_HASH_WITH_NETS */

#define SET_ELEM_EXPIRED(set, d)	\
	(SET_WITH_TIMEOUT(set) &&	\
	 ip_set_timeout_expired(ext_timeout(d, set)))

#endif /* _IP_SET_HASH_GEN_H */

#ifndef MTYPE
#error "MTYPE is not defined!"
#endif

#ifndef HTYPE
#error "HTYPE is not defined!"
#endif

#ifndef HOST_MASK
#error "HOST_MASK is not defined!"
#endif

/* Family dependent templates */

#undef ahash_data
#undef mtype_data_equal
#undef mtype_do_data_match
#undef mtype_data_set_flags
#undef mtype_data_reset_elem
#undef mtype_data_reset_flags
#undef mtype_data_netmask
#undef mtype_data_list
#undef mtype_data_next
#undef mtype_elem

#undef mtype_ahash_destroy
#undef mtype_ext_cleanup
#undef mtype_add_cidr
#undef mtype_del_cidr
#undef mtype_ahash_memsize
#undef mtype_flush
#undef mtype_destroy
#undef mtype_same_set
#undef mtype_kadt
#undef mtype_uadt

#undef mtype_add
#undef mtype_del
#undef mtype_test_cidrs
#undef mtype_test
#undef mtype_uref
#undef mtype_resize
#undef mtype_ext_size
#undef mtype_resize_ad
#undef mtype_head
#undef mtype_list
#undef mtype_gc_do
#undef mtype_gc
#undef mtype_gc_init
#undef mtype_variant
#undef mtype_data_match

#undef htype
#undef HKEY

#define mtype_data_equal	IPSET_TOKEN(MTYPE, _data_equal)
#ifdef IP_SET_HASH_WITH_NETS
#define mtype_do_data_match	IPSET_TOKEN(MTYPE, _do_data_match)
#else
#define mtype_do_data_match(d)	1
#endif
#define mtype_data_set_flags	IPSET_TOKEN(MTYPE, _data_set_flags)
#define mtype_data_reset_elem	IPSET_TOKEN(MTYPE, _data_reset_elem)
#define mtype_data_reset_flags	IPSET_TOKEN(MTYPE, _data_reset_flags)
#define mtype_data_netmask	IPSET_TOKEN(MTYPE, _data_netmask)
#define mtype_data_list		IPSET_TOKEN(MTYPE, _data_list)
#define mtype_data_next		IPSET_TOKEN(MTYPE, _data_next)
#define mtype_elem		IPSET_TOKEN(MTYPE, _elem)

#define mtype_ahash_destroy	IPSET_TOKEN(MTYPE, _ahash_destroy)
#define mtype_ext_cleanup	IPSET_TOKEN(MTYPE, _ext_cleanup)
#define mtype_add_cidr		IPSET_TOKEN(MTYPE, _add_cidr)
#define mtype_del_cidr		IPSET_TOKEN(MTYPE, _del_cidr)
#define mtype_ahash_memsize	IPSET_TOKEN(MTYPE, _ahash_memsize)
#define mtype_flush		IPSET_TOKEN(MTYPE, _flush)
#define mtype_destroy		IPSET_TOKEN(MTYPE, _destroy)
#define mtype_same_set		IPSET_TOKEN(MTYPE, _same_set)
#define mtype_kadt		IPSET_TOKEN(MTYPE, _kadt)
#define mtype_uadt		IPSET_TOKEN(MTYPE, _uadt)

#define mtype_add		IPSET_TOKEN(MTYPE, _add)
#define mtype_del		IPSET_TOKEN(MTYPE, _del)
#define mtype_test_cidrs	IPSET_TOKEN(MTYPE, _test_cidrs)
#define mtype_test		IPSET_TOKEN(MTYPE, _test)
#define mtype_uref		IPSET_TOKEN(MTYPE, _uref)
#define mtype_resize		IPSET_TOKEN(MTYPE, _resize)
#define mtype_ext_size		IPSET_TOKEN(MTYPE, _ext_size)
#define mtype_resize_ad		IPSET_TOKEN(MTYPE, _resize_ad)
#define mtype_head		IPSET_TOKEN(MTYPE, _head)
#define mtype_list		IPSET_TOKEN(MTYPE, _list)
#define mtype_gc_do		IPSET_TOKEN(MTYPE, _gc_do)
#define mtype_gc		IPSET_TOKEN(MTYPE, _gc)
#define mtype_gc_init		IPSET_TOKEN(MTYPE, _gc_init)
#define mtype_variant		IPSET_TOKEN(MTYPE, _variant)
#define mtype_data_match	IPSET_TOKEN(MTYPE, _data_match)

#ifndef HKEY_DATALEN
#define HKEY_DATALEN		sizeof(struct mtype_elem)
#endif

#define htype			MTYPE

#define HKEY(data, initval, htable_bits)			\
({								\
	const u32 *__k = (const u32 *)data;			\
	u32 __l = HKEY_DATALEN / sizeof(u32);			\
								\
	BUILD_BUG_ON(HKEY_DATALEN % sizeof(u32) != 0);		\
								\
	jhash2(__k, __l, initval) & jhash_mask(htable_bits);	\
})

/* The generic hash structure */
struct htype {
	struct htable __rcu *table; /* the hash table */
	struct htable_gc gc;	/* gc workqueue */
	u32 maxelem;		/* max elements in the hash */
	u32 initval;		/* random jhash init value */
#ifdef IP_SET_HASH_WITH_MARKMASK
	u32 markmask;		/* markmask value for mark mask to store */
#endif
	u8 bucketsize;		/* max elements in an array block */
#ifdef IP_SET_HASH_WITH_NETMASK
	u8 netmask;		/* netmask value for subnets to store */
#endif
	struct list_head ad;	/* Resize add|del backlist */
	struct mtype_elem next; /* temporary storage for uadd */
#ifdef IP_SET_HASH_WITH_NETS
	struct net_prefixes nets[NLEN]; /* book-keeping of prefixes */
#endif
};

/* ADD|DEL entries saved during resize */
struct mtype_resize_ad {
	struct list_head list;
	enum ipset_adt ad;	/* ADD|DEL element */
	struct mtype_elem d;	/* Element value */
	struct ip_set_ext ext;	/* Extensions for ADD */
	struct ip_set_ext mext;	/* Target extensions for ADD */
	u32 flags;		/* Flags for ADD */
};

#ifdef IP_SET_HASH_WITH_NETS
/* Network cidr size book keeping when the hash stores different
 * sized networks. cidr == real cidr + 1 to support /0.
 */
static void
mtype_add_cidr(struct ip_set *set, struct htype *h, u8 cidr, u8 n)
{
	int i, j;

	spin_lock_bh(&set->lock);
	/* Add in increasing prefix order, so larger cidr first */
	for (i = 0, j = -1; i < NLEN && h->nets[i].cidr[n]; i++) {
		if (j != -1) {
			continue;
		} else if (h->nets[i].cidr[n] < cidr) {
			j = i;
		} else if (h->nets[i].cidr[n] == cidr) {
			h->nets[CIDR_POS(cidr)].nets[n]++;
			goto unlock;
		}
	}
	if (j != -1) {
		for (; i > j; i--)
			h->nets[i].cidr[n] = h->nets[i - 1].cidr[n];
	}
	h->nets[i].cidr[n] = cidr;
	h->nets[CIDR_POS(cidr)].nets[n] = 1;
unlock:
	spin_unlock_bh(&set->lock);
}

static void
mtype_del_cidr(struct ip_set *set, struct htype *h, u8 cidr, u8 n)
{
	u8 i, j, net_end = NLEN - 1;

	spin_lock_bh(&set->lock);
	for (i = 0; i < NLEN; i++) {
		if (h->nets[i].cidr[n] != cidr)
			continue;
		h->nets[CIDR_POS(cidr)].nets[n]--;
		if (h->nets[CIDR_POS(cidr)].nets[n] > 0)
			goto unlock;
		for (j = i; j < net_end && h->nets[j].cidr[n]; j++)
			h->nets[j].cidr[n] = h->nets[j + 1].cidr[n];
		h->nets[j].cidr[n] = 0;
		goto unlock;
	}
unlock:
	spin_unlock_bh(&set->lock);
}
#endif

/* Calculate the actual memory size of the set data */
static size_t
mtype_ahash_memsize(const struct htype *h, const struct htable *t)
{
	return sizeof(*h) + sizeof(*t) + ahash_sizeof_regions(t->htable_bits);
}

/* Get the ith element from the array block n */
#define ahash_data(n, i, dsize)	\
	((struct mtype_elem *)((n)->value + ((i) * (dsize))))

static void
mtype_ext_cleanup(struct ip_set *set, struct hbucket *n)
{
	int i;

	for (i = 0; i < n->pos; i++)
		if (test_bit(i, n->used))
			ip_set_ext_destroy(set, ahash_data(n, i, set->dsize));
}

/* Flush a hash type of set: destroy all elements */
static void
mtype_flush(struct ip_set *set)
{
	struct htype *h = set->data;
	struct htable *t;
	struct hbucket *n;
	u32 r, i;

	t = ipset_dereference_nfnl(h->table);
	for (r = 0; r < ahash_numof_locks(t->htable_bits); r++) {
		spin_lock_bh(&t->hregion[r].lock);
		for (i = ahash_bucket_start(r, t->htable_bits);
		     i < ahash_bucket_end(r, t->htable_bits); i++) {
			n = __ipset_dereference(hbucket(t, i));
			if (!n)
				continue;
			if (set->extensions & IPSET_EXT_DESTROY)
				mtype_ext_cleanup(set, n);
			/* FIXME: use slab cache */
			rcu_assign_pointer(hbucket(t, i), NULL);
			kfree_rcu(n, rcu);
		}
		t->hregion[r].ext_size = 0;
		t->hregion[r].elements = 0;
		spin_unlock_bh(&t->hregion[r].lock);
	}
#ifdef IP_SET_HASH_WITH_NETS
	memset(h->nets, 0, sizeof(h->nets));
#endif
}

/* Destroy the hashtable part of the set */
static void
mtype_ahash_destroy(struct ip_set *set, struct htable *t, bool ext_destroy)
{
	struct hbucket *n;
	u32 i;

	for (i = 0; i < jhash_size(t->htable_bits); i++) {
		n = __ipset_dereference(hbucket(t, i));
		if (!n)
			continue;
		if (set->extensions & IPSET_EXT_DESTROY && ext_destroy)
			mtype_ext_cleanup(set, n);
		/* FIXME: use slab cache */
		kfree(n);
	}

	ip_set_free(t->hregion);
	ip_set_free(t);
}

/* Destroy a hash type of set */
static void
mtype_destroy(struct ip_set *set)
{
	struct htype *h = set->data;
	struct list_head *l, *lt;

	if (SET_WITH_TIMEOUT(set))
		cancel_delayed_work_sync(&h->gc.dwork);

	mtype_ahash_destroy(set, ipset_dereference_nfnl(h->table), true);
	list_for_each_safe(l, lt, &h->ad) {
		list_del(l);
		kfree(l);
	}
	kfree(h);

	set->data = NULL;
}

static bool
mtype_same_set(const struct ip_set *a, const struct ip_set *b)
{
	const struct htype *x = a->data;
	const struct htype *y = b->data;

	/* Resizing changes htable_bits, so we ignore it */
	return x->maxelem == y->maxelem &&
	       a->timeout == b->timeout &&
#ifdef IP_SET_HASH_WITH_NETMASK
	       x->netmask == y->netmask &&
#endif
#ifdef IP_SET_HASH_WITH_MARKMASK
	       x->markmask == y->markmask &&
#endif
	       a->extensions == b->extensions;
}

static void
mtype_gc_do(struct ip_set *set, struct htype *h, struct htable *t, u32 r)
{
	struct hbucket *n, *tmp;
	struct mtype_elem *data;
	u32 i, j, d;
	size_t dsize = set->dsize;
#ifdef IP_SET_HASH_WITH_NETS
	u8 k;
#endif
	u8 htable_bits = t->htable_bits;

	spin_lock_bh(&t->hregion[r].lock);
	for (i = ahash_bucket_start(r, htable_bits);
	     i < ahash_bucket_end(r, htable_bits); i++) {
		n = __ipset_dereference(hbucket(t, i));
		if (!n)
			continue;
		for (j = 0, d = 0; j < n->pos; j++) {
			if (!test_bit(j, n->used)) {
				d++;
				continue;
			}
			data = ahash_data(n, j, dsize);
			if (!ip_set_timeout_expired(ext_timeout(data, set)))
				continue;
			pr_debug("expired %u/%u\n", i, j);
			clear_bit(j, n->used);
			smp_mb__after_atomic();
#ifdef IP_SET_HASH_WITH_NETS
			for (k = 0; k < IPSET_NET_COUNT; k++)
				mtype_del_cidr(set, h,
					NCIDR_PUT(DCIDR_GET(data->cidr, k)),
					k);
#endif
			t->hregion[r].elements--;
			ip_set_ext_destroy(set, data);
			d++;
		}
		if (d >= AHASH_INIT_SIZE) {
			if (d >= n->size) {
				t->hregion[r].ext_size -=
					ext_size(n->size, dsize);
				rcu_assign_pointer(hbucket(t, i), NULL);
				kfree_rcu(n, rcu);
				continue;
			}
			tmp = kzalloc(sizeof(*tmp) +
				(n->size - AHASH_INIT_SIZE) * dsize,
				GFP_ATOMIC);
			if (!tmp)
				/* Still try to delete expired elements. */
				continue;
			tmp->size = n->size - AHASH_INIT_SIZE;
			for (j = 0, d = 0; j < n->pos; j++) {
				if (!test_bit(j, n->used))
					continue;
				data = ahash_data(n, j, dsize);
				memcpy(tmp->value + d * dsize,
				       data, dsize);
				set_bit(d, tmp->used);
				d++;
			}
			tmp->pos = d;
			t->hregion[r].ext_size -=
				ext_size(AHASH_INIT_SIZE, dsize);
			rcu_assign_pointer(hbucket(t, i), tmp);
			kfree_rcu(n, rcu);
		}
	}
	spin_unlock_bh(&t->hregion[r].lock);
}

static void
mtype_gc(struct work_struct *work)
{
	struct htable_gc *gc;
	struct ip_set *set;
	struct htype *h;
	struct htable *t;
	u32 r, numof_locks;
	unsigned int next_run;

	gc = container_of(work, struct htable_gc, dwork.work);
	set = gc->set;
	h = set->data;

	spin_lock_bh(&set->lock);
	t = ipset_dereference_set(h->table, set);
	atomic_inc(&t->uref);
	numof_locks = ahash_numof_locks(t->htable_bits);
	r = gc->region++;
	if (r >= numof_locks) {
		r = gc->region = 0;
	}
	next_run = (IPSET_GC_PERIOD(set->timeout) * HZ) / numof_locks;
	if (next_run < HZ/10)
		next_run = HZ/10;
	spin_unlock_bh(&set->lock);

	mtype_gc_do(set, h, t, r);

	if (atomic_dec_and_test(&t->uref) && atomic_read(&t->ref)) {
		pr_debug("Table destroy after resize by expire: %p\n", t);
		mtype_ahash_destroy(set, t, false);
	}

	queue_delayed_work(system_power_efficient_wq, &gc->dwork, next_run);

}

static void
mtype_gc_init(struct htable_gc *gc)
{
	INIT_DEFERRABLE_WORK(&gc->dwork, mtype_gc);
	queue_delayed_work(system_power_efficient_wq, &gc->dwork, HZ);
}

static int
mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext,
	  struct ip_set_ext *mext, u32 flags);
static int
mtype_del(struct ip_set *set, void *value, const struct ip_set_ext *ext,
	  struct ip_set_ext *mext, u32 flags);

/* Resize a hash: create a new hash table with doubling the hashsize
 * and inserting the elements to it. Repeat until we succeed or
 * fail due to memory pressures.
 */
static int
mtype_resize(struct ip_set *set, bool retried)
{
	struct htype *h = set->data;
	struct htable *t, *orig;
	u8 htable_bits;
	size_t hsize, dsize = set->dsize;
#ifdef IP_SET_HASH_WITH_NETS
	u8 flags;
	struct mtype_elem *tmp;
#endif
	struct mtype_elem *data;
	struct mtype_elem *d;
	struct hbucket *n, *m;
	struct list_head *l, *lt;
	struct mtype_resize_ad *x;
	u32 i, j, r, nr, key;
	int ret;

#ifdef IP_SET_HASH_WITH_NETS
	tmp = kmalloc(dsize, GFP_KERNEL);
	if (!tmp)
		return -ENOMEM;
#endif
	orig = ipset_dereference_bh_nfnl(h->table);
	htable_bits = orig->htable_bits;

retry:
	ret = 0;
	htable_bits++;
	if (!htable_bits)
		goto hbwarn;
	hsize = htable_size(htable_bits);
	if (!hsize)
		goto hbwarn;
	t = ip_set_alloc(hsize);
	if (!t) {
		ret = -ENOMEM;
		goto out;
	}
	t->hregion = ip_set_alloc(ahash_sizeof_regions(htable_bits));
	if (!t->hregion) {
		ip_set_free(t);
		ret = -ENOMEM;
		goto out;
	}
	t->htable_bits = htable_bits;
	t->maxelem = h->maxelem / ahash_numof_locks(htable_bits);
	for (i = 0; i < ahash_numof_locks(htable_bits); i++)
		spin_lock_init(&t->hregion[i].lock);

	/* There can't be another parallel resizing,
	 * but dumping, gc, kernel side add/del are possible
	 */
	orig = ipset_dereference_bh_nfnl(h->table);
	atomic_set(&orig->ref, 1);
	atomic_inc(&orig->uref);
	pr_debug("attempt to resize set %s from %u to %u, t %p\n",
		 set->name, orig->htable_bits, htable_bits, orig);
	for (r = 0; r < ahash_numof_locks(orig->htable_bits); r++) {
		/* Expire may replace a hbucket with another one */
		rcu_read_lock_bh();
		for (i = ahash_bucket_start(r, orig->htable_bits);
		     i < ahash_bucket_end(r, orig->htable_bits); i++) {
			n = __ipset_dereference(hbucket(orig, i));
			if (!n)
				continue;
			for (j = 0; j < n->pos; j++) {
				if (!test_bit(j, n->used))
					continue;
				data = ahash_data(n, j, dsize);
				if (SET_ELEM_EXPIRED(set, data))
					continue;
#ifdef IP_SET_HASH_WITH_NETS
				/* We have readers running parallel with us,
				 * so the live data cannot be modified.
				 */
				flags = 0;
				memcpy(tmp, data, dsize);
				data = tmp;
				mtype_data_reset_flags(data, &flags);
#endif
				key = HKEY(data, h->initval, htable_bits);
				m = __ipset_dereference(hbucket(t, key));
				nr = ahash_region(key, htable_bits);
				if (!m) {
					m = kzalloc(sizeof(*m) +
					    AHASH_INIT_SIZE * dsize,
					    GFP_ATOMIC);
					if (!m) {
						ret = -ENOMEM;
						goto cleanup;
					}
					m->size = AHASH_INIT_SIZE;
					t->hregion[nr].ext_size +=
						ext_size(AHASH_INIT_SIZE,
							 dsize);
					RCU_INIT_POINTER(hbucket(t, key), m);
				} else if (m->pos >= m->size) {
					struct hbucket *ht;

					if (m->size >= AHASH_MAX(h)) {
						ret = -EAGAIN;
					} else {
						ht = kzalloc(sizeof(*ht) +
						(m->size + AHASH_INIT_SIZE)
						* dsize,
						GFP_ATOMIC);
						if (!ht)
							ret = -ENOMEM;
					}
					if (ret < 0)
						goto cleanup;
					memcpy(ht, m, sizeof(struct hbucket) +
					       m->size * dsize);
					ht->size = m->size + AHASH_INIT_SIZE;
					t->hregion[nr].ext_size +=
						ext_size(AHASH_INIT_SIZE,
							 dsize);
					kfree(m);
					m = ht;
					RCU_INIT_POINTER(hbucket(t, key), ht);
				}
				d = ahash_data(m, m->pos, dsize);
				memcpy(d, data, dsize);
				set_bit(m->pos++, m->used);
				t->hregion[nr].elements++;
#ifdef IP_SET_HASH_WITH_NETS
				mtype_data_reset_flags(d, &flags);
#endif
			}
		}
		rcu_read_unlock_bh();
	}

	/* There can't be any other writer. */
	rcu_assign_pointer(h->table, t);

	/* Give time to other readers of the set */
	synchronize_rcu();

	pr_debug("set %s resized from %u (%p) to %u (%p)\n", set->name,
		 orig->htable_bits, orig, t->htable_bits, t);
	/* Add/delete elements processed by the SET target during resize.
	 * Kernel-side add cannot trigger a resize and userspace actions
	 * are serialized by the mutex.
	 */
	list_for_each_safe(l, lt, &h->ad) {
		x = list_entry(l, struct mtype_resize_ad, list);
		if (x->ad == IPSET_ADD) {
			mtype_add(set, &x->d, &x->ext, &x->mext, x->flags);
		} else {
			mtype_del(set, &x->d, NULL, NULL, 0);
		}
		list_del(l);
		kfree(l);
	}
	/* If there's nobody else using the table, destroy it */
	if (atomic_dec_and_test(&orig->uref)) {
		pr_debug("Table destroy by resize %p\n", orig);
		mtype_ahash_destroy(set, orig, false);
	}

out:
#ifdef IP_SET_HASH_WITH_NETS
	kfree(tmp);
#endif
	return ret;

cleanup:
	rcu_read_unlock_bh();
	atomic_set(&orig->ref, 0);
	atomic_dec(&orig->uref);
	mtype_ahash_destroy(set, t, false);
	if (ret == -EAGAIN)
		goto retry;
	goto out;

hbwarn:
	/* In case we have plenty of memory :-) */
	pr_warn("Cannot increase the hashsize of set %s further\n", set->name);
	ret = -IPSET_ERR_HASH_FULL;
	goto out;
}

/* Get the current number of elements and ext_size in the set  */
static void
mtype_ext_size(struct ip_set *set, u32 *elements, size_t *ext_size)
{
	struct htype *h = set->data;
	const struct htable *t;
	u32 i, j, r;
	struct hbucket *n;
	struct mtype_elem *data;

	t = rcu_dereference_bh(h->table);
	for (r = 0; r < ahash_numof_locks(t->htable_bits); r++) {
		for (i = ahash_bucket_start(r, t->htable_bits);
		     i < ahash_bucket_end(r, t->htable_bits); i++) {
			n = rcu_dereference_bh(hbucket(t, i));
			if (!n)
				continue;
			for (j = 0; j < n->pos; j++) {
				if (!test_bit(j, n->used))
					continue;
				data = ahash_data(n, j, set->dsize);
				if (!SET_ELEM_EXPIRED(set, data))
					(*elements)++;
			}
		}
		*ext_size += t->hregion[r].ext_size;
	}
}

/* Add an element to a hash and update the internal counters when succeeded,
 * otherwise report the proper error code.
 */
static int
mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext,
	  struct ip_set_ext *mext, u32 flags)
{
	struct htype *h = set->data;
	struct htable *t;
	const struct mtype_elem *d = value;
	struct mtype_elem *data;
	struct hbucket *n, *old = ERR_PTR(-ENOENT);
	int i, j = -1, ret;
	bool flag_exist = flags & IPSET_FLAG_EXIST;
	bool deleted = false, forceadd = false, reuse = false;
	u32 r, key, multi = 0, elements, maxelem;

	rcu_read_lock_bh();
	t = rcu_dereference_bh(h->table);
	key = HKEY(value, h->initval, t->htable_bits);
	r = ahash_region(key, t->htable_bits);
	atomic_inc(&t->uref);
	elements = t->hregion[r].elements;
	maxelem = t->maxelem;
	if (elements >= maxelem) {
		u32 e;
		if (SET_WITH_TIMEOUT(set)) {
			rcu_read_unlock_bh();
			mtype_gc_do(set, h, t, r);
			rcu_read_lock_bh();
		}
		maxelem = h->maxelem;
		elements = 0;
		for (e = 0; e < ahash_numof_locks(t->htable_bits); e++)
			elements += t->hregion[e].elements;
		if (elements >= maxelem && SET_WITH_FORCEADD(set))
			forceadd = true;
	}
	rcu_read_unlock_bh();

	spin_lock_bh(&t->hregion[r].lock);
	n = rcu_dereference_bh(hbucket(t, key));
	if (!n) {
		if (forceadd || elements >= maxelem)
			goto set_full;
		old = NULL;
		n = kzalloc(sizeof(*n) + AHASH_INIT_SIZE * set->dsize,
			    GFP_ATOMIC);
		if (!n) {
			ret = -ENOMEM;
			goto unlock;
		}
		n->size = AHASH_INIT_SIZE;
		t->hregion[r].ext_size +=
			ext_size(AHASH_INIT_SIZE, set->dsize);
		goto copy_elem;
	}
	for (i = 0; i < n->pos; i++) {
		if (!test_bit(i, n->used)) {
			/* Reuse first deleted entry */
			if (j == -1) {
				deleted = reuse = true;
				j = i;
			}
			continue;
		}
		data = ahash_data(n, i, set->dsize);
		if (mtype_data_equal(data, d, &multi)) {
			if (flag_exist || SET_ELEM_EXPIRED(set, data)) {
				/* Just the extensions could be overwritten */
				j = i;
				goto overwrite_extensions;
			}
			ret = -IPSET_ERR_EXIST;
			goto unlock;
		}
		/* Reuse first timed out entry */
		if (SET_ELEM_EXPIRED(set, data) && j == -1) {
			j = i;
			reuse = true;
		}
	}
	if (reuse || forceadd) {
		if (j == -1)
			j = 0;
		data = ahash_data(n, j, set->dsize);
		if (!deleted) {
#ifdef IP_SET_HASH_WITH_NETS
			for (i = 0; i < IPSET_NET_COUNT; i++)
				mtype_del_cidr(set, h,
					NCIDR_PUT(DCIDR_GET(data->cidr, i)),
					i);
#endif
			ip_set_ext_destroy(set, data);
			t->hregion[r].elements--;
		}
		goto copy_data;
	}
	if (elements >= maxelem)
		goto set_full;
	/* Create a new slot */
	if (n->pos >= n->size) {
#ifdef IP_SET_HASH_WITH_MULTI
		if (h->bucketsize >= AHASH_MAX_TUNED)
			goto set_full;
		else if (h->bucketsize <= multi)
			h->bucketsize += AHASH_INIT_SIZE;
#endif
		if (n->size >= AHASH_MAX(h)) {
			/* Trigger rehashing */
			mtype_data_next(&h->next, d);
			ret = -EAGAIN;
			goto resize;
		}
		old = n;
		n = kzalloc(sizeof(*n) +
			    (old->size + AHASH_INIT_SIZE) * set->dsize,
			    GFP_ATOMIC);
		if (!n) {
			ret = -ENOMEM;
			goto unlock;
		}
		memcpy(n, old, sizeof(struct hbucket) +
		       old->size * set->dsize);
		n->size = old->size + AHASH_INIT_SIZE;
		t->hregion[r].ext_size +=
			ext_size(AHASH_INIT_SIZE, set->dsize);
	}

copy_elem:
	j = n->pos++;
	data = ahash_data(n, j, set->dsize);
copy_data:
	t->hregion[r].elements++;
#ifdef IP_SET_HASH_WITH_NETS
	for (i = 0; i < IPSET_NET_COUNT; i++)
		mtype_add_cidr(set, h, NCIDR_PUT(DCIDR_GET(d->cidr, i)), i);
#endif
	memcpy(data, d, sizeof(struct mtype_elem));
overwrite_extensions:
#ifdef IP_SET_HASH_WITH_NETS
	mtype_data_set_flags(data, flags);
#endif
	if (SET_WITH_COUNTER(set))
		ip_set_init_counter(ext_counter(data, set), ext);
	if (SET_WITH_COMMENT(set))
		ip_set_init_comment(set, ext_comment(data, set), ext);
	if (SET_WITH_SKBINFO(set))
		ip_set_init_skbinfo(ext_skbinfo(data, set), ext);
	/* Must come last for the case when timed out entry is reused */
	if (SET_WITH_TIMEOUT(set))
		ip_set_timeout_set(ext_timeout(data, set), ext->timeout);
	smp_mb__before_atomic();
	set_bit(j, n->used);
	if (old != ERR_PTR(-ENOENT)) {
		rcu_assign_pointer(hbucket(t, key), n);
		if (old)
			kfree_rcu(old, rcu);
	}
	ret = 0;
resize:
	spin_unlock_bh(&t->hregion[r].lock);
	if (atomic_read(&t->ref) && ext->target) {
		/* Resize is in process and kernel side add, save values */
		struct mtype_resize_ad *x;

		x = kzalloc(sizeof(struct mtype_resize_ad), GFP_ATOMIC);
		if (!x)
			/* Don't bother */
			goto out;
		x->ad = IPSET_ADD;
		memcpy(&x->d, value, sizeof(struct mtype_elem));
		memcpy(&x->ext, ext, sizeof(struct ip_set_ext));
		memcpy(&x->mext, mext, sizeof(struct ip_set_ext));
		x->flags = flags;
		spin_lock_bh(&set->lock);
		list_add_tail(&x->list, &h->ad);
		spin_unlock_bh(&set->lock);
	}
	goto out;

set_full:
	if (net_ratelimit())
		pr_warn("Set %s is full, maxelem %u reached\n",
			set->name, maxelem);
	ret = -IPSET_ERR_HASH_FULL;
unlock:
	spin_unlock_bh(&t->hregion[r].lock);
out:
	if (atomic_dec_and_test(&t->uref) && atomic_read(&t->ref)) {
		pr_debug("Table destroy after resize by add: %p\n", t);
		mtype_ahash_destroy(set, t, false);
	}
	return ret;
}

/* Delete an element from the hash and free up space if possible.
 */
static int
mtype_del(struct ip_set *set, void *value, const struct ip_set_ext *ext,
	  struct ip_set_ext *mext, u32 flags)
{
	struct htype *h = set->data;
	struct htable *t;
	const struct mtype_elem *d = value;
	struct mtype_elem *data;
	struct hbucket *n;
	struct mtype_resize_ad *x = NULL;
	int i, j, k, r, ret = -IPSET_ERR_EXIST;
	u32 key, multi = 0;
	size_t dsize = set->dsize;

	/* Userspace add and resize is excluded by the mutex.
	 * Kernespace add does not trigger resize.
	 */
	rcu_read_lock_bh();
	t = rcu_dereference_bh(h->table);
	key = HKEY(value, h->initval, t->htable_bits);
	r = ahash_region(key, t->htable_bits);
	atomic_inc(&t->uref);
	rcu_read_unlock_bh();

	spin_lock_bh(&t->hregion[r].lock);
	n = rcu_dereference_bh(hbucket(t, key));
	if (!n)
		goto out;
	for (i = 0, k = 0; i < n->pos; i++) {
		if (!test_bit(i, n->used)) {
			k++;
			continue;
		}
		data = ahash_data(n, i, dsize);
		if (!mtype_data_equal(data, d, &multi))
			continue;
		if (SET_ELEM_EXPIRED(set, data))
			goto out;

		ret = 0;
		clear_bit(i, n->used);
		smp_mb__after_atomic();
		if (i + 1 == n->pos)
			n->pos--;
		t->hregion[r].elements--;
#ifdef IP_SET_HASH_WITH_NETS
		for (j = 0; j < IPSET_NET_COUNT; j++)
			mtype_del_cidr(set, h,
				       NCIDR_PUT(DCIDR_GET(d->cidr, j)), j);
#endif
		ip_set_ext_destroy(set, data);

		if (atomic_read(&t->ref) && ext->target) {
			/* Resize is in process and kernel side del,
			 * save values
			 */
			x = kzalloc(sizeof(struct mtype_resize_ad),
				    GFP_ATOMIC);
			if (x) {
				x->ad = IPSET_DEL;
				memcpy(&x->d, value,
				       sizeof(struct mtype_elem));
				x->flags = flags;
			}
		}
		for (; i < n->pos; i++) {
			if (!test_bit(i, n->used))
				k++;
		}
		if (n->pos == 0 && k == 0) {
			t->hregion[r].ext_size -= ext_size(n->size, dsize);
			rcu_assign_pointer(hbucket(t, key), NULL);
			kfree_rcu(n, rcu);
		} else if (k >= AHASH_INIT_SIZE) {
			struct hbucket *tmp = kzalloc(sizeof(*tmp) +
					(n->size - AHASH_INIT_SIZE) * dsize,
					GFP_ATOMIC);
			if (!tmp)
				goto out;
			tmp->size = n->size - AHASH_INIT_SIZE;
			for (j = 0, k = 0; j < n->pos; j++) {
				if (!test_bit(j, n->used))
					continue;
				data = ahash_data(n, j, dsize);
				memcpy(tmp->value + k * dsize, data, dsize);
				set_bit(k, tmp->used);
				k++;
			}
			tmp->pos = k;
			t->hregion[r].ext_size -=
				ext_size(AHASH_INIT_SIZE, dsize);
			rcu_assign_pointer(hbucket(t, key), tmp);
			kfree_rcu(n, rcu);
		}
		goto out;
	}

out:
	spin_unlock_bh(&t->hregion[r].lock);
	if (x) {
		spin_lock_bh(&set->lock);
		list_add(&x->list, &h->ad);
		spin_unlock_bh(&set->lock);
	}
	if (atomic_dec_and_test(&t->uref) && atomic_read(&t->ref)) {
		pr_debug("Table destroy after resize by del: %p\n", t);
		mtype_ahash_destroy(set, t, false);
	}
	return ret;
}

static int
mtype_data_match(struct mtype_elem *data, const struct ip_set_ext *ext,
		 struct ip_set_ext *mext, struct ip_set *set, u32 flags)
{
	if (!ip_set_match_extensions(set, ext, mext, flags, data))
		return 0;
	/* nomatch entries return -ENOTEMPTY */
	return mtype_do_data_match(data);
}

#ifdef IP_SET_HASH_WITH_NETS
/* Special test function which takes into account the different network
 * sizes added to the set
 */
static int
mtype_test_cidrs(struct ip_set *set, struct mtype_elem *d,
		 const struct ip_set_ext *ext,
		 struct ip_set_ext *mext, u32 flags)
{
	struct htype *h = set->data;
	struct htable *t = rcu_dereference_bh(h->table);
	struct hbucket *n;
	struct mtype_elem *data;
#if IPSET_NET_COUNT == 2
	struct mtype_elem orig = *d;
	int ret, i, j = 0, k;
#else
	int ret, i, j = 0;
#endif
	u32 key, multi = 0;

	pr_debug("test by nets\n");
	for (; j < NLEN && h->nets[j].cidr[0] && !multi; j++) {
#if IPSET_NET_COUNT == 2
		mtype_data_reset_elem(d, &orig);
		mtype_data_netmask(d, NCIDR_GET(h->nets[j].cidr[0]), false);
		for (k = 0; k < NLEN && h->nets[k].cidr[1] && !multi;
		     k++) {
			mtype_data_netmask(d, NCIDR_GET(h->nets[k].cidr[1]),
					   true);
#else
		mtype_data_netmask(d, NCIDR_GET(h->nets[j].cidr[0]));
#endif
		key = HKEY(d, h->initval, t->htable_bits);
		n = rcu_dereference_bh(hbucket(t, key));
		if (!n)
			continue;
		for (i = 0; i < n->pos; i++) {
			if (!test_bit(i, n->used))
				continue;
			data = ahash_data(n, i, set->dsize);
			if (!mtype_data_equal(data, d, &multi))
				continue;
			ret = mtype_data_match(data, ext, mext, set, flags);
			if (ret != 0)
				return ret;
#ifdef IP_SET_HASH_WITH_MULTI
			/* No match, reset multiple match flag */
			multi = 0;
#endif
		}
#if IPSET_NET_COUNT == 2
		}
#endif
	}
	return 0;
}
#endif

/* Test whether the element is added to the set */
static int
mtype_test(struct ip_set *set, void *value, const struct ip_set_ext *ext,
	   struct ip_set_ext *mext, u32 flags)
{
	struct htype *h = set->data;
	struct htable *t;
	struct mtype_elem *d = value;
	struct hbucket *n;
	struct mtype_elem *data;
	int i, ret = 0;
	u32 key, multi = 0;

	rcu_read_lock_bh();
	t = rcu_dereference_bh(h->table);
#ifdef IP_SET_HASH_WITH_NETS
	/* If we test an IP address and not a network address,
	 * try all possible network sizes
	 */
	for (i = 0; i < IPSET_NET_COUNT; i++)
		if (DCIDR_GET(d->cidr, i) != HOST_MASK)
			break;
	if (i == IPSET_NET_COUNT) {
		ret = mtype_test_cidrs(set, d, ext, mext, flags);
		goto out;
	}
#endif

	key = HKEY(d, h->initval, t->htable_bits);
	n = rcu_dereference_bh(hbucket(t, key));
	if (!n) {
		ret = 0;
		goto out;
	}
	for (i = 0; i < n->pos; i++) {
		if (!test_bit(i, n->used))
			continue;
		data = ahash_data(n, i, set->dsize);
		if (!mtype_data_equal(data, d, &multi))
			continue;
		ret = mtype_data_match(data, ext, mext, set, flags);
		if (ret != 0)
			goto out;
	}
out:
	rcu_read_unlock_bh();
	return ret;
}

/* Reply a HEADER request: fill out the header part of the set */
static int
mtype_head(struct ip_set *set, struct sk_buff *skb)
{
	struct htype *h = set->data;
	const struct htable *t;
	struct nlattr *nested;
	size_t memsize;
	u32 elements = 0;
	size_t ext_size = 0;
	u8 htable_bits;

	rcu_read_lock_bh();
	t = rcu_dereference_bh(h->table);
	mtype_ext_size(set, &elements, &ext_size);
	memsize = mtype_ahash_memsize(h, t) + ext_size + set->ext_size;
	htable_bits = t->htable_bits;
	rcu_read_unlock_bh();

	nested = nla_nest_start(skb, IPSET_ATTR_DATA);
	if (!nested)
		goto nla_put_failure;
	if (nla_put_net32(skb, IPSET_ATTR_HASHSIZE,
			  htonl(jhash_size(htable_bits))) ||
	    nla_put_net32(skb, IPSET_ATTR_MAXELEM, htonl(h->maxelem)))
		goto nla_put_failure;
#ifdef IP_SET_HASH_WITH_NETMASK
	if (h->netmask != HOST_MASK &&
	    nla_put_u8(skb, IPSET_ATTR_NETMASK, h->netmask))
		goto nla_put_failure;
#endif
#ifdef IP_SET_HASH_WITH_MARKMASK
	if (nla_put_u32(skb, IPSET_ATTR_MARKMASK, h->markmask))
		goto nla_put_failure;
#endif
	if (set->flags & IPSET_CREATE_FLAG_BUCKETSIZE) {
		if (nla_put_u8(skb, IPSET_ATTR_BUCKETSIZE, h->bucketsize) ||
		    nla_put_net32(skb, IPSET_ATTR_INITVAL, htonl(h->initval)))
			goto nla_put_failure;
	}
	if (nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref)) ||
	    nla_put_net32(skb, IPSET_ATTR_MEMSIZE, htonl(memsize)) ||
	    nla_put_net32(skb, IPSET_ATTR_ELEMENTS, htonl(elements)))
		goto nla_put_failure;
	if (unlikely(ip_set_put_flags(skb, set)))
		goto nla_put_failure;
	nla_nest_end(skb, nested);

	return 0;
nla_put_failure:
	return -EMSGSIZE;
}

/* Make possible to run dumping parallel with resizing */
static void
mtype_uref(struct ip_set *set, struct netlink_callback *cb, bool start)
{
	struct htype *h = set->data;
	struct htable *t;

	if (start) {
		rcu_read_lock_bh();
		t = ipset_dereference_bh_nfnl(h->table);
		atomic_inc(&t->uref);
		cb->args[IPSET_CB_PRIVATE] = (unsigned long)t;
		rcu_read_unlock_bh();
	} else if (cb->args[IPSET_CB_PRIVATE]) {
		t = (struct htable *)cb->args[IPSET_CB_PRIVATE];
		if (atomic_dec_and_test(&t->uref) && atomic_read(&t->ref)) {
			pr_debug("Table destroy after resize "
				 " by dump: %p\n", t);
			mtype_ahash_destroy(set, t, false);
		}
		cb->args[IPSET_CB_PRIVATE] = 0;
	}
}

/* Reply a LIST/SAVE request: dump the elements of the specified set */
static int
mtype_list(const struct ip_set *set,
	   struct sk_buff *skb, struct netlink_callback *cb)
{
	const struct htable *t;
	struct nlattr *atd, *nested;
	const struct hbucket *n;
	const struct mtype_elem *e;
	u32 first = cb->args[IPSET_CB_ARG0];
	/* We assume that one hash bucket fills into one page */
	void *incomplete;
	int i, ret = 0;

	atd = nla_nest_start(skb, IPSET_ATTR_ADT);
	if (!atd)
		return -EMSGSIZE;

	pr_debug("list hash set %s\n", set->name);
	t = (const struct htable *)cb->args[IPSET_CB_PRIVATE];
	/* Expire may replace a hbucket with another one */
	rcu_read_lock();
	for (; cb->args[IPSET_CB_ARG0] < jhash_size(t->htable_bits);
	     cb->args[IPSET_CB_ARG0]++) {
		cond_resched_rcu();
		incomplete = skb_tail_pointer(skb);
		n = rcu_dereference(hbucket(t, cb->args[IPSET_CB_ARG0]));
		pr_debug("cb->arg bucket: %lu, t %p n %p\n",
			 cb->args[IPSET_CB_ARG0], t, n);
		if (!n)
			continue;
		for (i = 0; i < n->pos; i++) {
			if (!test_bit(i, n->used))
				continue;
			e = ahash_data(n, i, set->dsize);
			if (SET_ELEM_EXPIRED(set, e))
				continue;
			pr_debug("list hash %lu hbucket %p i %u, data %p\n",
				 cb->args[IPSET_CB_ARG0], n, i, e);
			nested = nla_nest_start(skb, IPSET_ATTR_DATA);
			if (!nested) {
				if (cb->args[IPSET_CB_ARG0] == first) {
					nla_nest_cancel(skb, atd);
					ret = -EMSGSIZE;
					goto out;
				}
				goto nla_put_failure;
			}
			if (mtype_data_list(skb, e))
				goto nla_put_failure;
			if (ip_set_put_extensions(skb, set, e, true))
				goto nla_put_failure;
			nla_nest_end(skb, nested);
		}
	}
	nla_nest_end(skb, atd);
	/* Set listing finished */
	cb->args[IPSET_CB_ARG0] = 0;

	goto out;

nla_put_failure:
	nlmsg_trim(skb, incomplete);
	if (unlikely(first == cb->args[IPSET_CB_ARG0])) {
		pr_warn("Can't list set %s: one bucket does not fit into a message. Please report it!\n",
			set->name);
		cb->args[IPSET_CB_ARG0] = 0;
		ret = -EMSGSIZE;
	} else {
		nla_nest_end(skb, atd);
	}
out:
	rcu_read_unlock();
	return ret;
}

static int
IPSET_TOKEN(MTYPE, _kadt)(struct ip_set *set, const struct sk_buff *skb,
			  const struct xt_action_param *par,
			  enum ipset_adt adt, struct ip_set_adt_opt *opt);

static int
IPSET_TOKEN(MTYPE, _uadt)(struct ip_set *set, struct nlattr *tb[],
			  enum ipset_adt adt, u32 *lineno, u32 flags,
			  bool retried);

static const struct ip_set_type_variant mtype_variant = {
	.kadt	= mtype_kadt,
	.uadt	= mtype_uadt,
	.adt	= {
		[IPSET_ADD] = mtype_add,
		[IPSET_DEL] = mtype_del,
		[IPSET_TEST] = mtype_test,
	},
	.destroy = mtype_destroy,
	.flush	= mtype_flush,
	.head	= mtype_head,
	.list	= mtype_list,
	.uref	= mtype_uref,
	.resize	= mtype_resize,
	.same_set = mtype_same_set,
	.region_lock = true,
};

#ifdef IP_SET_EMIT_CREATE
static int
IPSET_TOKEN(HTYPE, _create)(struct net *net, struct ip_set *set,
			    struct nlattr *tb[], u32 flags)
{
	u32 hashsize = IPSET_DEFAULT_HASHSIZE, maxelem = IPSET_DEFAULT_MAXELEM;
#ifdef IP_SET_HASH_WITH_MARKMASK
	u32 markmask;
#endif
	u8 hbits;
#ifdef IP_SET_HASH_WITH_NETMASK
	u8 netmask;
#endif
	size_t hsize;
	struct htype *h;
	struct htable *t;
	u32 i;

	pr_debug("Create set %s with family %s\n",
		 set->name, set->family == NFPROTO_IPV4 ? "inet" : "inet6");

#ifdef IP_SET_PROTO_UNDEF
	if (set->family != NFPROTO_UNSPEC)
		return -IPSET_ERR_INVALID_FAMILY;
#else
	if (!(set->family == NFPROTO_IPV4 || set->family == NFPROTO_IPV6))
		return -IPSET_ERR_INVALID_FAMILY;
#endif

	if (unlikely(!ip_set_optattr_netorder(tb, IPSET_ATTR_HASHSIZE) ||
		     !ip_set_optattr_netorder(tb, IPSET_ATTR_MAXELEM) ||
		     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
		     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
		return -IPSET_ERR_PROTOCOL;

#ifdef IP_SET_HASH_WITH_MARKMASK
	/* Separated condition in order to avoid directive in argument list */
	if (unlikely(!ip_set_optattr_netorder(tb, IPSET_ATTR_MARKMASK)))
		return -IPSET_ERR_PROTOCOL;

	markmask = 0xffffffff;
	if (tb[IPSET_ATTR_MARKMASK]) {
		markmask = ntohl(nla_get_be32(tb[IPSET_ATTR_MARKMASK]));
		if (markmask == 0)
			return -IPSET_ERR_INVALID_MARKMASK;
	}
#endif

#ifdef IP_SET_HASH_WITH_NETMASK
	netmask = set->family == NFPROTO_IPV4 ? 32 : 128;
	if (tb[IPSET_ATTR_NETMASK]) {
		netmask = nla_get_u8(tb[IPSET_ATTR_NETMASK]);

		if ((set->family == NFPROTO_IPV4 && netmask > 32) ||
		    (set->family == NFPROTO_IPV6 && netmask > 128) ||
		    netmask == 0)
			return -IPSET_ERR_INVALID_NETMASK;
	}
#endif

	if (tb[IPSET_ATTR_HASHSIZE]) {
		hashsize = ip_set_get_h32(tb[IPSET_ATTR_HASHSIZE]);
		if (hashsize < IPSET_MIMINAL_HASHSIZE)
			hashsize = IPSET_MIMINAL_HASHSIZE;
	}

	if (tb[IPSET_ATTR_MAXELEM])
		maxelem = ip_set_get_h32(tb[IPSET_ATTR_MAXELEM]);

	hsize = sizeof(*h);
	h = kzalloc(hsize, GFP_KERNEL);
	if (!h)
		return -ENOMEM;

	/* Compute htable_bits from the user input parameter hashsize.
	 * Assume that hashsize == 2^htable_bits,
	 * otherwise round up to the first 2^n value.
	 */
	hbits = fls(hashsize - 1);
	hsize = htable_size(hbits);
	if (hsize == 0) {
		kfree(h);
		return -ENOMEM;
	}
	t = ip_set_alloc(hsize);
	if (!t) {
		kfree(h);
		return -ENOMEM;
	}
	t->hregion = ip_set_alloc(ahash_sizeof_regions(hbits));
	if (!t->hregion) {
		ip_set_free(t);
		kfree(h);
		return -ENOMEM;
	}
	h->gc.set = set;
	for (i = 0; i < ahash_numof_locks(hbits); i++)
		spin_lock_init(&t->hregion[i].lock);
	h->maxelem = maxelem;
#ifdef IP_SET_HASH_WITH_NETMASK
	h->netmask = netmask;
#endif
#ifdef IP_SET_HASH_WITH_MARKMASK
	h->markmask = markmask;
#endif
	if (tb[IPSET_ATTR_INITVAL])
		h->initval = ntohl(nla_get_be32(tb[IPSET_ATTR_INITVAL]));
	else
		get_random_bytes(&h->initval, sizeof(h->initval));
	h->bucketsize = AHASH_MAX_SIZE;
	if (tb[IPSET_ATTR_BUCKETSIZE]) {
		h->bucketsize = nla_get_u8(tb[IPSET_ATTR_BUCKETSIZE]);
		if (h->bucketsize < AHASH_INIT_SIZE)
			h->bucketsize = AHASH_INIT_SIZE;
		else if (h->bucketsize > AHASH_MAX_SIZE)
			h->bucketsize = AHASH_MAX_SIZE;
		else if (h->bucketsize % 2)
			h->bucketsize += 1;
	}
	t->htable_bits = hbits;
	t->maxelem = h->maxelem / ahash_numof_locks(hbits);
	RCU_INIT_POINTER(h->table, t);

	INIT_LIST_HEAD(&h->ad);
	set->data = h;
#ifndef IP_SET_PROTO_UNDEF
	if (set->family == NFPROTO_IPV4) {
#endif
		set->variant = &IPSET_TOKEN(HTYPE, 4_variant);
		set->dsize = ip_set_elem_len(set, tb,
			sizeof(struct IPSET_TOKEN(HTYPE, 4_elem)),
			__alignof__(struct IPSET_TOKEN(HTYPE, 4_elem)));
#ifndef IP_SET_PROTO_UNDEF
	} else {
		set->variant = &IPSET_TOKEN(HTYPE, 6_variant);
		set->dsize = ip_set_elem_len(set, tb,
			sizeof(struct IPSET_TOKEN(HTYPE, 6_elem)),
			__alignof__(struct IPSET_TOKEN(HTYPE, 6_elem)));
	}
#endif
	set->timeout = IPSET_NO_TIMEOUT;
	if (tb[IPSET_ATTR_TIMEOUT]) {
		set->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
#ifndef IP_SET_PROTO_UNDEF
		if (set->family == NFPROTO_IPV4)
#endif
			IPSET_TOKEN(HTYPE, 4_gc_init)(&h->gc);
#ifndef IP_SET_PROTO_UNDEF
		else
			IPSET_TOKEN(HTYPE, 6_gc_init)(&h->gc);
#endif
	}
	pr_debug("create %s hashsize %u (%u) maxelem %u: %p(%p)\n",
		 set->name, jhash_size(t->htable_bits),
		 t->htable_bits, h->maxelem, set->data, t);

	return 0;
}
#endif /* IP_SET_EMIT_CREATE */

#undef HKEY_DATALEN