netfilter: ipset: Unified hash type generation

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 1039 insertions, 0 deletions

diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h
new file mode 100644
index 000000000000..2ba7d4e76cde
--- /dev/null
+++ b/net/netfilter/ipset/ip_set_hash_gen.h
@@ -0,0 +1,1039 @@
+/* Copyright (C) 2013 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
+ *
+ * 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.
+ */
+
+#ifndef _IP_SET_HASH_GEN_H
+#define _IP_SET_HASH_GEN_H
+
+#include <linux/rcupdate.h>
+#include <linux/jhash.h>
+#include <linux/netfilter/ipset/ip_set_timeout.h>
+#ifndef rcu_dereference_bh
+#define rcu_dereference_bh(p)	rcu_dereference(p)
+#endif
+
+#define CONCAT(a, b)		a##b
+#define TOKEN(a, b)		CONCAT(a, b)
+
+/* 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). If storage supports timeout,
+ * the timeout field must be the last one in the data structure - that field
+ * is ignored when computing the hash key.
+ *
+ * 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			4
+/* Max number of elements to store in an array block */
+#define AHASH_MAX_SIZE			(3*AHASH_INIT_SIZE)
+
+/* Max number of elements can be tuned */
+#ifdef IP_SET_HASH_WITH_MULTI
+#define AHASH_MAX(h)			((h)->ahash_max)
+
+static inline u8
+tune_ahash_max(u8 curr, u32 multi)
+{
+	u32 n;
+
+	if (multi < curr)
+		return curr;
+
+	n = curr + AHASH_INIT_SIZE;
+	/* Currently, at listing one hash bucket must fit into a message.
+	 * Therefore we have a hard limit here.
+	 */
+	return n > curr && n <= 64 ? n : curr;
+}
+#define TUNE_AHASH_MAX(h, multi)	\
+	((h)->ahash_max = tune_ahash_max((h)->ahash_max, multi))
+#else
+#define AHASH_MAX(h)			AHASH_MAX_SIZE
+#define TUNE_AHASH_MAX(h, multi)
+#endif
+
+/* A hash bucket */
+struct hbucket {
+	void *value;		/* the array of the values */
+	u8 size;		/* size of the array */
+	u8 pos;			/* position of the first free entry */
+};
+
+/* The hash table: the table size stored here in order to make resizing easy */
+struct htable {
+	u8 htable_bits;		/* size of hash table == 2^htable_bits */
+	struct hbucket bucket[0]; /* hashtable buckets */
+};
+
+#define hbucket(h, i)		(&((h)->bucket[i]))
+
+/* Book-keeping of the prefixes added to the set */
+struct net_prefixes {
+	u8 cidr;		/* the different cidr values in the set */
+	u32 nets;		/* number of elements per cidr */
+};
+
+/* Compute the hash table size */
+static size_t
+htable_size(u8 hbits)
+{
+	size_t hsize;
+
+	/* We must fit both into u32 in jhash and size_t */
+	if (hbits > 31)
+		return 0;
+	hsize = jhash_size(hbits);
+	if ((((size_t)-1) - sizeof(struct htable))/sizeof(struct hbucket)
+	    < hsize)
+		return 0;
+
+	return hsize * sizeof(struct hbucket) + sizeof(struct htable);
+}
+
+/* Compute htable_bits from the user input parameter hashsize */
+static u8
+htable_bits(u32 hashsize)
+{
+	/* Assume that hashsize == 2^htable_bits */
+	u8 bits = fls(hashsize - 1);
+	if (jhash_size(bits) != hashsize)
+		/* Round up to the first 2^n value */
+		bits = fls(hashsize);
+
+	return bits;
+}
+
+/* Destroy the hashtable part of the set */
+static void
+ahash_destroy(struct htable *t)
+{
+	struct hbucket *n;
+	u32 i;
+
+	for (i = 0; i < jhash_size(t->htable_bits); i++) {
+		n = hbucket(t, i);
+		if (n->size)
+			/* FIXME: use slab cache */
+			kfree(n->value);
+	}
+
+	ip_set_free(t);
+}
+
+static int
+hbucket_elem_add(struct hbucket *n, u8 ahash_max, size_t dsize)
+{
+	if (n->pos >= n->size) {
+		void *tmp;
+
+		if (n->size >= ahash_max)
+			/* Trigger rehashing */
+			return -EAGAIN;
+
+		tmp = kzalloc((n->size + AHASH_INIT_SIZE) * dsize,
+			      GFP_ATOMIC);
+		if (!tmp)
+			return -ENOMEM;
+		if (n->size) {
+			memcpy(tmp, n->value, n->size * dsize);
+			kfree(n->value);
+		}
+		n->value = tmp;
+		n->size += AHASH_INIT_SIZE;
+	}
+	return 0;
+}
+
+#ifdef IP_SET_HASH_WITH_NETS
+#ifdef IP_SET_HASH_WITH_NETS_PACKED
+/* When cidr is packed with nomatch, cidr - 1 is stored in the entry */
+#define CIDR(cidr)		(cidr + 1)
+#else
+#define CIDR(cidr)		(cidr)
+#endif
+
+#define SET_HOST_MASK(family)	(family == AF_INET ? 32 : 128)
+
+#ifdef IP_SET_HASH_WITH_MULTI
+#define NETS_LENGTH(family)	(SET_HOST_MASK(family) + 1)
+#else
+#define NETS_LENGTH(family)	SET_HOST_MASK(family)
+#endif
+
+#else
+#define NETS_LENGTH(family)	0
+#endif /* IP_SET_HASH_WITH_NETS */
+
+#define ext_timeout(e, h)	\
+(unsigned long *)(((void *)(e)) + (h)->offset[IPSET_OFFSET_TIMEOUT])
+
+#endif /* _IP_SET_HASH_GEN_H */
+
+/* Family dependent templates */
+
+#undef ahash_data
+#undef mtype_data_equal
+#undef mtype_do_data_match
+#undef mtype_data_set_flags
+#undef mtype_data_reset_flags
+#undef mtype_data_netmask
+#undef mtype_data_list
+#undef mtype_data_next
+#undef mtype_elem
+
+#undef mtype_add_cidr
+#undef mtype_del_cidr
+#undef mtype_ahash_memsize
+#undef mtype_flush
+#undef mtype_destroy
+#undef mtype_gc_init
+#undef mtype_same_set
+#undef mtype_kadt
+#undef mtype_uadt
+#undef mtype
+
+#undef mtype_add
+#undef mtype_del
+#undef mtype_test_cidrs
+#undef mtype_test
+#undef mtype_expire
+#undef mtype_resize
+#undef mtype_head
+#undef mtype_list
+#undef mtype_gc
+#undef mtype_gc_init
+#undef mtype_variant
+#undef mtype_data_match
+
+#undef HKEY
+
+#define mtype_data_equal	TOKEN(MTYPE, _data_equal)
+#ifdef IP_SET_HASH_WITH_NETS
+#define mtype_do_data_match	TOKEN(MTYPE, _do_data_match)
+#else
+#define mtype_do_data_match(d)	1
+#endif
+#define mtype_data_set_flags	TOKEN(MTYPE, _data_set_flags)
+#define mtype_data_reset_flags	TOKEN(MTYPE, _data_reset_flags)
+#define mtype_data_netmask	TOKEN(MTYPE, _data_netmask)
+#define mtype_data_list		TOKEN(MTYPE, _data_list)
+#define mtype_data_next		TOKEN(MTYPE, _data_next)
+#define mtype_elem		TOKEN(MTYPE, _elem)
+#define mtype_add_cidr		TOKEN(MTYPE, _add_cidr)
+#define mtype_del_cidr		TOKEN(MTYPE, _del_cidr)
+#define mtype_ahash_memsize	TOKEN(MTYPE, _ahash_memsize)
+#define mtype_flush		TOKEN(MTYPE, _flush)
+#define mtype_destroy		TOKEN(MTYPE, _destroy)
+#define mtype_gc_init		TOKEN(MTYPE, _gc_init)
+#define mtype_same_set		TOKEN(MTYPE, _same_set)
+#define mtype_kadt		TOKEN(MTYPE, _kadt)
+#define mtype_uadt		TOKEN(MTYPE, _uadt)
+#define mtype			MTYPE
+
+#define mtype_elem		TOKEN(MTYPE, _elem)
+#define mtype_add		TOKEN(MTYPE, _add)
+#define mtype_del		TOKEN(MTYPE, _del)
+#define mtype_test_cidrs	TOKEN(MTYPE, _test_cidrs)
+#define mtype_test		TOKEN(MTYPE, _test)
+#define mtype_expire		TOKEN(MTYPE, _expire)
+#define mtype_resize		TOKEN(MTYPE, _resize)
+#define mtype_head		TOKEN(MTYPE, _head)
+#define mtype_list		TOKEN(MTYPE, _list)
+#define mtype_gc		TOKEN(MTYPE, _gc)
+#define mtype_variant		TOKEN(MTYPE, _variant)
+#define mtype_data_match	TOKEN(MTYPE, _data_match)
+
+#ifndef HKEY_DATALEN
+#define HKEY_DATALEN		sizeof(struct mtype_elem)
+#endif
+
+#define HKEY(data, initval, htable_bits)			\
+(jhash2((u32 *)(data), HKEY_DATALEN/sizeof(u32), initval)	\
+	& jhash_mask(htable_bits))
+
+#ifndef htype
+#define htype			HTYPE
+
+/* The generic hash structure */
+struct htype {
+	struct htable *table;	/* the hash table */
+	u32 maxelem;		/* max elements in the hash */
+	u32 elements;		/* current element (vs timeout) */
+	u32 initval;		/* random jhash init value */
+	u32 timeout;		/* timeout value, if enabled */
+	size_t dsize;		/* data struct size */
+	size_t offset[IPSET_OFFSET_MAX]; /* Offsets to extensions */
+	struct timer_list gc;	/* garbage collection when timeout enabled */
+	struct mtype_elem next; /* temporary storage for uadd */
+#ifdef IP_SET_HASH_WITH_MULTI
+	u8 ahash_max;		/* max elements in an array block */
+#endif
+#ifdef IP_SET_HASH_WITH_NETMASK
+	u8 netmask;		/* netmask value for subnets to store */
+#endif
+#ifdef IP_SET_HASH_WITH_RBTREE
+	struct rb_root rbtree;
+#endif
+#ifdef IP_SET_HASH_WITH_NETS
+	struct net_prefixes nets[0]; /* book-keeping of prefixes */
+#endif
+};
+#endif
+
+#ifdef IP_SET_HASH_WITH_NETS
+/* Network cidr size book keeping when the hash stores different
+ * sized networks */
+static void
+mtype_add_cidr(struct htype *h, u8 cidr, u8 nets_length)
+{
+	int i, j;
+
+	/* Add in increasing prefix order, so larger cidr first */
+	for (i = 0, j = -1; i < nets_length && h->nets[i].nets; i++) {
+		if (j != -1)
+			continue;
+		else if (h->nets[i].cidr < cidr)
+			j = i;
+		else if (h->nets[i].cidr == cidr) {
+			h->nets[i].nets++;
+			return;
+		}
+	}
+	if (j != -1) {
+		for (; i > j; i--) {
+			h->nets[i].cidr = h->nets[i - 1].cidr;
+			h->nets[i].nets = h->nets[i - 1].nets;
+		}
+	}
+	h->nets[i].cidr = cidr;
+	h->nets[i].nets = 1;
+}
+
+static void
+mtype_del_cidr(struct htype *h, u8 cidr, u8 nets_length)
+{
+	u8 i, j;
+
+	for (i = 0; i < nets_length - 1 && h->nets[i].cidr != cidr; i++)
+		;
+	h->nets[i].nets--;
+
+	if (h->nets[i].nets != 0)
+		return;
+
+	for (j = i; j < nets_length - 1 && h->nets[j].nets; j++) {
+		h->nets[j].cidr = h->nets[j + 1].cidr;
+		h->nets[j].nets = h->nets[j + 1].nets;
+	}
+}
+#endif
+
+/* Calculate the actual memory size of the set data */
+static size_t
+mtype_ahash_memsize(const struct htype *h, u8 nets_length)
+{
+	u32 i;
+	struct htable *t = h->table;
+	size_t memsize = sizeof(*h)
+			 + sizeof(*t)
+#ifdef IP_SET_HASH_WITH_NETS
+			 + sizeof(struct net_prefixes) * nets_length
+#endif
+			 + jhash_size(t->htable_bits) * sizeof(struct hbucket);
+
+	for (i = 0; i < jhash_size(t->htable_bits); i++)
+		memsize += t->bucket[i].size * h->dsize;
+
+	return memsize;
+}
+
+/* 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 = h->table;
+	struct hbucket *n;
+	u32 i;
+
+	for (i = 0; i < jhash_size(t->htable_bits); i++) {
+		n = hbucket(t, i);
+		if (n->size) {
+			n->size = n->pos = 0;
+			/* FIXME: use slab cache */
+			kfree(n->value);
+		}
+	}
+#ifdef IP_SET_HASH_WITH_NETS
+	memset(h->nets, 0, sizeof(struct net_prefixes)
+			   * NETS_LENGTH(set->family));
+#endif
+	h->elements = 0;
+}
+
+/* Destroy a hash type of set */
+static void
+mtype_destroy(struct ip_set *set)
+{
+	struct htype *h = set->data;
+
+	if (set->extensions & IPSET_EXT_TIMEOUT)
+		del_timer_sync(&h->gc);
+
+	ahash_destroy(h->table);
+#ifdef IP_SET_HASH_WITH_RBTREE
+	rbtree_destroy(&h->rbtree);
+#endif
+	kfree(h);
+
+	set->data = NULL;
+}
+
+static void
+mtype_gc_init(struct ip_set *set, void (*gc)(unsigned long ul_set))
+{
+	struct htype *h = set->data;
+
+	init_timer(&h->gc);
+	h->gc.data = (unsigned long) set;
+	h->gc.function = gc;
+	h->gc.expires = jiffies + IPSET_GC_PERIOD(h->timeout) * HZ;
+	add_timer(&h->gc);
+	pr_debug("gc initialized, run in every %u\n",
+		 IPSET_GC_PERIOD(h->timeout));
+}
+
+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 &&
+	       x->timeout == y->timeout &&
+#ifdef IP_SET_HASH_WITH_NETMASK
+	       x->netmask == y->netmask &&
+#endif
+	       a->extensions == b->extensions;
+}
+
+/* Get the ith element from the array block n */
+#define ahash_data(n, i, dsize)	\
+	((struct mtype_elem *)((n)->value + ((i) * (dsize))))
+
+/* Delete expired elements from the hashtable */
+static void
+mtype_expire(struct htype *h, u8 nets_length, size_t dsize)
+{
+	struct htable *t = h->table;
+	struct hbucket *n;
+	struct mtype_elem *data;
+	u32 i;
+	int j;
+
+	for (i = 0; i < jhash_size(t->htable_bits); i++) {
+		n = hbucket(t, i);
+		for (j = 0; j < n->pos; j++) {
+			data = ahash_data(n, j, dsize);
+			if (ip_set_timeout_expired(ext_timeout(data, h))) {
+				pr_debug("expired %u/%u\n", i, j);
+#ifdef IP_SET_HASH_WITH_NETS
+				mtype_del_cidr(h, CIDR(data->cidr),
+					       nets_length);
+#endif
+				if (j != n->pos - 1)
+					/* Not last one */
+					memcpy(data,
+					       ahash_data(n, n->pos - 1, dsize),
+					       dsize);
+				n->pos--;
+				h->elements--;
+			}
+		}
+		if (n->pos + AHASH_INIT_SIZE < n->size) {
+			void *tmp = kzalloc((n->size - AHASH_INIT_SIZE)
+					    * dsize,
+					    GFP_ATOMIC);
+			if (!tmp)
+				/* Still try to delete expired elements */
+				continue;
+			n->size -= AHASH_INIT_SIZE;
+			memcpy(tmp, n->value, n->size * dsize);
+			kfree(n->value);
+			n->value = tmp;
+		}
+	}
+}
+
+static void
+mtype_gc(unsigned long ul_set)
+{
+	struct ip_set *set = (struct ip_set *) ul_set;
+	struct htype *h = set->data;
+
+	pr_debug("called\n");
+	write_lock_bh(&set->lock);
+	mtype_expire(h, NETS_LENGTH(set->family), h->dsize);
+	write_unlock_bh(&set->lock);
+
+	h->gc.expires = jiffies + IPSET_GC_PERIOD(h->timeout) * HZ;
+	add_timer(&h->gc);
+}
+
+/* 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 = h->table;
+	u8 htable_bits = orig->htable_bits;
+#ifdef IP_SET_HASH_WITH_NETS
+	u8 flags;
+#endif
+	struct mtype_elem *data;
+	struct mtype_elem *d;
+	struct hbucket *n, *m;
+	u32 i, j;
+	int ret;
+
+	/* Try to cleanup once */
+	if (SET_WITH_TIMEOUT(set) && !retried) {
+		i = h->elements;
+		write_lock_bh(&set->lock);
+		mtype_expire(set->data, NETS_LENGTH(set->family),
+			     h->dsize);
+		write_unlock_bh(&set->lock);
+		if (h->elements < i)
+			return 0;
+	}
+
+retry:
+	ret = 0;
+	htable_bits++;
+	pr_debug("attempt to resize set %s from %u to %u, t %p\n",
+		 set->name, orig->htable_bits, htable_bits, orig);
+	if (!htable_bits) {
+		/* In case we have plenty of memory :-) */
+		pr_warning("Cannot increase the hashsize of set %s further\n",
+			   set->name);
+		return -IPSET_ERR_HASH_FULL;
+	}
+	t = ip_set_alloc(sizeof(*t)
+			 + jhash_size(htable_bits) * sizeof(struct hbucket));
+	if (!t)
+		return -ENOMEM;
+	t->htable_bits = htable_bits;
+
+	read_lock_bh(&set->lock);
+	for (i = 0; i < jhash_size(orig->htable_bits); i++) {
+		n = hbucket(orig, i);
+		for (j = 0; j < n->pos; j++) {
+			data = ahash_data(n, j, h->dsize);
+#ifdef IP_SET_HASH_WITH_NETS
+			flags = 0;
+			mtype_data_reset_flags(data, &flags);
+#endif
+			m = hbucket(t, HKEY(data, h->initval, htable_bits));
+			ret = hbucket_elem_add(m, AHASH_MAX(h), h->dsize);
+			if (ret < 0) {
+#ifdef IP_SET_HASH_WITH_NETS
+				mtype_data_reset_flags(data, &flags);
+#endif
+				read_unlock_bh(&set->lock);
+				ahash_destroy(t);
+				if (ret == -EAGAIN)
+					goto retry;
+				return ret;
+			}
+			d = ahash_data(m, m->pos++, h->dsize);
+			memcpy(d, data, h->dsize);
+#ifdef IP_SET_HASH_WITH_NETS
+			mtype_data_reset_flags(d, &flags);
+#endif
+		}
+	}
+
+	rcu_assign_pointer(h->table, t);
+	read_unlock_bh(&set->lock);
+
+	/* Give time to other readers of the set */
+	synchronize_rcu_bh();
+
+	pr_debug("set %s resized from %u (%p) to %u (%p)\n", set->name,
+		 orig->htable_bits, orig, t->htable_bits, t);
+	ahash_destroy(orig);
+
+	return 0;
+}
+
+/* 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;
+	int i, ret = 0;
+	int j = AHASH_MAX(h) + 1;
+	bool flag_exist = flags & IPSET_FLAG_EXIST;
+	u32 key, multi = 0;
+
+	if (SET_WITH_TIMEOUT(set) && h->elements >= h->maxelem)
+		/* FIXME: when set is full, we slow down here */
+		mtype_expire(h, NETS_LENGTH(set->family), h->dsize);
+
+	if (h->elements >= h->maxelem) {
+		if (net_ratelimit())
+			pr_warning("Set %s is full, maxelem %u reached\n",
+				   set->name, h->maxelem);
+		return -IPSET_ERR_HASH_FULL;
+	}
+
+	rcu_read_lock_bh();
+	t = rcu_dereference_bh(h->table);
+	key = HKEY(value, h->initval, t->htable_bits);
+	n = hbucket(t, key);
+	for (i = 0; i < n->pos; i++) {
+		data = ahash_data(n, i, h->dsize);
+		if (mtype_data_equal(data, d, &multi)) {
+			if (flag_exist ||
+			    (SET_WITH_TIMEOUT(set) &&
+			     ip_set_timeout_expired(ext_timeout(data, h)))) {
+				/* Just the extensions could be overwritten */
+				j = i;
+				goto reuse_slot;
+			} else {
+				ret = -IPSET_ERR_EXIST;
+				goto out;
+			}
+		}
+		/* Reuse first timed out entry */
+		if (SET_WITH_TIMEOUT(set) &&
+		    ip_set_timeout_expired(ext_timeout(data, h)) &&
+		    j != AHASH_MAX(h) + 1)
+			j = i;
+	}
+reuse_slot:
+	if (j != AHASH_MAX(h) + 1) {
+		/* Fill out reused slot */
+		data = ahash_data(n, j, h->dsize);
+#ifdef IP_SET_HASH_WITH_NETS
+		mtype_del_cidr(h, CIDR(data->cidr), NETS_LENGTH(set->family));
+		mtype_add_cidr(h, CIDR(d->cidr), NETS_LENGTH(set->family));
+#endif
+	} else {
+		/* Use/create a new slot */
+		TUNE_AHASH_MAX(h, multi);
+		ret = hbucket_elem_add(n, AHASH_MAX(h), h->dsize);
+		if (ret != 0) {
+			if (ret == -EAGAIN)
+				mtype_data_next(&h->next, d);
+			goto out;
+		}
+		data = ahash_data(n, n->pos++, h->dsize);
+#ifdef IP_SET_HASH_WITH_NETS
+		mtype_add_cidr(h, CIDR(d->cidr), NETS_LENGTH(set->family));
+#endif
+		h->elements++;
+	}
+	memcpy(data, d, sizeof(struct mtype_elem));
+#ifdef IP_SET_HASH_WITH_NETS
+	mtype_data_set_flags(data, flags);
+#endif
+	if (SET_WITH_TIMEOUT(set))
+		ip_set_timeout_set(ext_timeout(data, h), ext->timeout);
+
+out:
+	rcu_read_unlock_bh();
+	return ret;
+}
+
+/* Delete an element from the hash: swap it with the last element
+ * 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 = h->table;
+	const struct mtype_elem *d = value;
+	struct mtype_elem *data;
+	struct hbucket *n;
+	int i;
+	u32 key, multi = 0;
+
+	key = HKEY(value, h->initval, t->htable_bits);
+	n = hbucket(t, key);
+	for (i = 0; i < n->pos; i++) {
+		data = ahash_data(n, i, h->dsize);
+		if (!mtype_data_equal(data, d, &multi))
+			continue;
+		if (SET_WITH_TIMEOUT(set) &&
+		    ip_set_timeout_expired(ext_timeout(data, h)))
+			return -IPSET_ERR_EXIST;
+		if (i != n->pos - 1)
+			/* Not last one */
+			memcpy(data, ahash_data(n, n->pos - 1, h->dsize),
+			       h->dsize);
+
+		n->pos--;
+		h->elements--;
+#ifdef IP_SET_HASH_WITH_NETS
+		mtype_del_cidr(h, CIDR(d->cidr), NETS_LENGTH(set->family));
+#endif
+		if (n->pos + AHASH_INIT_SIZE < n->size) {
+			void *tmp = kzalloc((n->size - AHASH_INIT_SIZE)
+					    * h->dsize,
+					    GFP_ATOMIC);
+			if (!tmp)
+				return 0;
+			n->size -= AHASH_INIT_SIZE;
+			memcpy(tmp, n->value, n->size * h->dsize);
+			kfree(n->value);
+			n->value = tmp;
+		}
+		return 0;
+	}
+
+	return -IPSET_ERR_EXIST;
+}
+
+static inline 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)
+{
+	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 = h->table;
+	struct hbucket *n;
+	struct mtype_elem *data;
+	int i, j = 0;
+	u32 key, multi = 0;
+	u8 nets_length = NETS_LENGTH(set->family);
+
+	pr_debug("test by nets\n");
+	for (; j < nets_length && h->nets[j].nets && !multi; j++) {
+		mtype_data_netmask(d, h->nets[j].cidr);
+		key = HKEY(d, h->initval, t->htable_bits);
+		n = hbucket(t, key);
+		for (i = 0; i < n->pos; i++) {
+			data = ahash_data(n, i, h->dsize);
+			if (!mtype_data_equal(data, d, &multi))
+				continue;
+			if (SET_WITH_TIMEOUT(set)) {
+				if (!ip_set_timeout_expired(
+							ext_timeout(data, h)))
+					return mtype_data_match(data, ext,
+								mext, set,
+								flags);
+#ifdef IP_SET_HASH_WITH_MULTI
+				multi = 0;
+#endif
+			} else
+				return mtype_data_match(data, ext,
+							mext, set, flags);
+		}
+	}
+	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 = h->table;
+	struct mtype_elem *d = value;
+	struct hbucket *n;
+	struct mtype_elem *data;
+	int i;
+	u32 key, multi = 0;
+
+#ifdef IP_SET_HASH_WITH_NETS
+	/* If we test an IP address and not a network address,
+	 * try all possible network sizes */
+	if (CIDR(d->cidr) == SET_HOST_MASK(set->family))
+		return mtype_test_cidrs(set, d, ext, mext, flags);
+#endif
+
+	key = HKEY(d, h->initval, t->htable_bits);
+	n = hbucket(t, key);
+	for (i = 0; i < n->pos; i++) {
+		data = ahash_data(n, i, h->dsize);
+		if (mtype_data_equal(data, d, &multi) &&
+		    !(SET_WITH_TIMEOUT(set) &&
+		      ip_set_timeout_expired(ext_timeout(data, h))))
+			return mtype_data_match(data, ext, mext, set, flags);
+	}
+	return 0;
+}
+
+/* Reply a HEADER request: fill out the header part of the set */
+static int
+mtype_head(struct ip_set *set, struct sk_buff *skb)
+{
+	const struct htype *h = set->data;
+	struct nlattr *nested;
+	size_t memsize;
+
+	read_lock_bh(&set->lock);
+	memsize = mtype_ahash_memsize(h, NETS_LENGTH(set->family));
+	read_unlock_bh(&set->lock);
+
+	nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
+	if (!nested)
+		goto nla_put_failure;
+	if (nla_put_net32(skb, IPSET_ATTR_HASHSIZE,
+			  htonl(jhash_size(h->table->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
+	if (nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref - 1)) ||
+	    nla_put_net32(skb, IPSET_ATTR_MEMSIZE, htonl(memsize)) ||
+	    ((set->extensions & IPSET_EXT_TIMEOUT) &&
+	     nla_put_net32(skb, IPSET_ATTR_TIMEOUT, htonl(h->timeout))))
+		goto nla_put_failure;
+	ipset_nest_end(skb, nested);
+
+	return 0;
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+/* 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 htype *h = set->data;
+	const struct htable *t = h->table;
+	struct nlattr *atd, *nested;
+	const struct hbucket *n;
+	const struct mtype_elem *e;
+	u32 first = cb->args[2];
+	/* We assume that one hash bucket fills into one page */
+	void *incomplete;
+	int i;
+
+	atd = ipset_nest_start(skb, IPSET_ATTR_ADT);
+	if (!atd)
+		return -EMSGSIZE;
+	pr_debug("list hash set %s\n", set->name);
+	for (; cb->args[2] < jhash_size(t->htable_bits); cb->args[2]++) {
+		incomplete = skb_tail_pointer(skb);
+		n = hbucket(t, cb->args[2]);
+		pr_debug("cb->args[2]: %lu, t %p n %p\n", cb->args[2], t, n);
+		for (i = 0; i < n->pos; i++) {
+			e = ahash_data(n, i, h->dsize);
+			if (SET_WITH_TIMEOUT(set) &&
+			    ip_set_timeout_expired(ext_timeout(e, h)))
+				continue;
+			pr_debug("list hash %lu hbucket %p i %u, data %p\n",
+				 cb->args[2], n, i, e);
+			nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
+			if (!nested) {
+				if (cb->args[2] == first) {
+					nla_nest_cancel(skb, atd);
+					return -EMSGSIZE;
+				} else
+					goto nla_put_failure;
+			}
+			if (mtype_data_list(skb, e))
+				goto nla_put_failure;
+			if (SET_WITH_TIMEOUT(set) &&
+			    nla_put_net32(skb, IPSET_ATTR_TIMEOUT,
+					  htonl(ip_set_timeout_get(
+						ext_timeout(e, h)))))
+				goto nla_put_failure;
+			ipset_nest_end(skb, nested);
+		}
+	}
+	ipset_nest_end(skb, atd);
+	/* Set listing finished */
+	cb->args[2] = 0;
+
+	return 0;
+
+nla_put_failure:
+	nlmsg_trim(skb, incomplete);
+	ipset_nest_end(skb, atd);
+	if (unlikely(first == cb->args[2])) {
+		pr_warning("Can't list set %s: one bucket does not fit into "
+			   "a message. Please report it!\n", set->name);
+		cb->args[2] = 0;
+		return -EMSGSIZE;
+	}
+	return 0;
+}
+
+static int
+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
+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,
+	.resize	= mtype_resize,
+	.same_set = mtype_same_set,
+};
+
+#ifdef IP_SET_EMIT_CREATE
+static int
+TOKEN(HTYPE, _create)(struct ip_set *set, struct nlattr *tb[], u32 flags)
+{
+	u32 hashsize = IPSET_DEFAULT_HASHSIZE, maxelem = IPSET_DEFAULT_MAXELEM;
+	u8 hbits;
+#ifdef IP_SET_HASH_WITH_NETMASK
+	u8 netmask;
+#endif
+	size_t hsize;
+	struct HTYPE *h;
+
+	if (!(set->family == NFPROTO_IPV4 || set->family == NFPROTO_IPV6))
+		return -IPSET_ERR_INVALID_FAMILY;
+#ifdef IP_SET_HASH_WITH_NETMASK
+	netmask = set->family == NFPROTO_IPV4 ? 32 : 128;
+	pr_debug("Create set %s with family %s\n",
+		 set->name, set->family == NFPROTO_IPV4 ? "inet" : "inet6");
+#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;
+
+	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]);
+
+#ifdef IP_SET_HASH_WITH_NETMASK
+	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
+
+	hsize = sizeof(*h);
+#ifdef IP_SET_HASH_WITH_NETS
+	hsize += sizeof(struct net_prefixes) *
+		(set->family == NFPROTO_IPV4 ? 32 : 128);
+#endif
+	h = kzalloc(hsize, GFP_KERNEL);
+	if (!h)
+		return -ENOMEM;
+
+	h->maxelem = maxelem;
+#ifdef IP_SET_HASH_WITH_NETMASK
+	h->netmask = netmask;
+#endif
+	get_random_bytes(&h->initval, sizeof(h->initval));
+	h->timeout = IPSET_NO_TIMEOUT;
+
+	hbits = htable_bits(hashsize);
+	hsize = htable_size(hbits);
+	if (hsize == 0) {
+		kfree(h);
+		return -ENOMEM;
+	}
+	h->table = ip_set_alloc(hsize);
+	if (!h->table) {
+		kfree(h);
+		return -ENOMEM;
+	}
+	h->table->htable_bits = hbits;
+
+	set->data = h;
+	if (set->family ==  NFPROTO_IPV4)
+		set->variant = &TOKEN(HTYPE, 4_variant);
+	else
+		set->variant = &TOKEN(HTYPE, 6_variant);
+
+	if (tb[IPSET_ATTR_TIMEOUT]) {
+		h->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
+		set->extensions |= IPSET_EXT_TIMEOUT;
+		if (set->family == NFPROTO_IPV4) {
+			h->dsize = sizeof(struct TOKEN(HTYPE, 4t_elem));
+			h->offset[IPSET_OFFSET_TIMEOUT] =
+				offsetof(struct TOKEN(HTYPE, 4t_elem),
+					 timeout);
+			TOKEN(HTYPE, 4_gc_init)(set, TOKEN(HTYPE, 4_gc));
+		} else {
+			h->dsize = sizeof(struct TOKEN(HTYPE, 6t_elem));
+			h->offset[IPSET_OFFSET_TIMEOUT] =
+				offsetof(struct TOKEN(HTYPE, 6t_elem),
+					 timeout);
+			TOKEN(HTYPE, 6_gc_init)(set, TOKEN(HTYPE, 6_gc));
+		}
+	} else {
+		if (set->family == NFPROTO_IPV4)
+			h->dsize = sizeof(struct TOKEN(HTYPE, 4_elem));
+		else
+			h->dsize = sizeof(struct TOKEN(HTYPE, 6_elem));
+	}
+
+	pr_debug("create %s hashsize %u (%u) maxelem %u: %p(%p)\n",
+		 set->name, jhash_size(h->table->htable_bits),
+		 h->table->htable_bits, h->maxelem, set->data, h->table);
+
+	return 0;
+}
+#endif /* IP_SET_EMIT_CREATE */