[deliverable/linux.git] / net / netfilter / xt_connlimit.c

/*
 * netfilter module to limit the number of parallel tcp
 * connections per IP address.
 *   (c) 2000 Gerd Knorr <kraxel@bytesex.org>
 *   Nov 2002: Martin Bene <martin.bene@icomedias.com>:
 *		only ignore TIME_WAIT or gone connections
 *   (C) CC Computer Consultants GmbH, 2007
 *
 * based on ...
 *
 * Kernel module to match connection tracking information.
 * GPL (C) 1999  Rusty Russell (rusty@rustcorp.com.au).
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/jhash.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/netfilter/nf_conntrack_tcp.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_connlimit.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_tuple.h>
#include <net/netfilter/nf_conntrack_zones.h>

/* we will save the tuples of all connections we care about */
struct xt_connlimit_conn {
	struct hlist_node		node;
	struct nf_conntrack_tuple	tuple;
	union nf_inet_addr		addr;
};

struct xt_connlimit_data {
	struct hlist_head	iphash[256];
	spinlock_t		lock;
};

static u_int32_t connlimit_rnd __read_mostly;
static struct kmem_cache *connlimit_conn_cachep __read_mostly;

static inline unsigned int connlimit_iphash(__be32 addr)
{
	return jhash_1word((__force __u32)addr, connlimit_rnd) & 0xFF;
}

static inline unsigned int
connlimit_iphash6(const union nf_inet_addr *addr,
                  const union nf_inet_addr *mask)
{
	union nf_inet_addr res;
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(addr->ip6); ++i)
		res.ip6[i] = addr->ip6[i] & mask->ip6[i];

	return jhash2((u32 *)res.ip6, ARRAY_SIZE(res.ip6), connlimit_rnd) & 0xFF;
}

static inline bool already_closed(const struct nf_conn *conn)
{
	if (nf_ct_protonum(conn) == IPPROTO_TCP)
		return conn->proto.tcp.state == TCP_CONNTRACK_TIME_WAIT ||
		       conn->proto.tcp.state == TCP_CONNTRACK_CLOSE;
	else
		return 0;
}

static inline unsigned int
same_source_net(const union nf_inet_addr *addr,
		const union nf_inet_addr *mask,
		const union nf_inet_addr *u3, u_int8_t family)
{
	if (family == NFPROTO_IPV4) {
		return (addr->ip & mask->ip) == (u3->ip & mask->ip);
	} else {
		union nf_inet_addr lh, rh;
		unsigned int i;

		for (i = 0; i < ARRAY_SIZE(addr->ip6); ++i) {
			lh.ip6[i] = addr->ip6[i] & mask->ip6[i];
			rh.ip6[i] = u3->ip6[i] & mask->ip6[i];
		}

		return memcmp(&lh.ip6, &rh.ip6, sizeof(lh.ip6)) == 0;
	}
}

static int count_hlist(struct net *net,
		       struct hlist_head *head,
		       const struct nf_conntrack_tuple *tuple,
		       const union nf_inet_addr *addr,
		       const union nf_inet_addr *mask,
		       u_int8_t family, bool *addit)
{
	const struct nf_conntrack_tuple_hash *found;
	struct xt_connlimit_conn *conn;
	struct hlist_node *n;
	struct nf_conn *found_ct;
	int matches = 0;

	rcu_read_lock();

	/* check the saved connections */
	hlist_for_each_entry_safe(conn, n, head, node) {
		found    = nf_conntrack_find_get(net, NF_CT_DEFAULT_ZONE,
						 &conn->tuple);
		if (found == NULL) {
			hlist_del(&conn->node);
			kmem_cache_free(connlimit_conn_cachep, conn);
			continue;
		}

		found_ct = nf_ct_tuplehash_to_ctrack(found);

		if (nf_ct_tuple_equal(&conn->tuple, tuple)) {
			/*
			 * Just to be sure we have it only once in the list.
			 * We should not see tuples twice unless someone hooks
			 * this into a table without "-p tcp --syn".
			 */
			*addit = false;
		} else if (already_closed(found_ct)) {
			/*
			 * we do not care about connections which are
			 * closed already -> ditch it
			 */
			nf_ct_put(found_ct);
			hlist_del(&conn->node);
			kmem_cache_free(connlimit_conn_cachep, conn);
			continue;
		}

		if (same_source_net(addr, mask, &conn->addr, family))
			/* same source network -> be counted! */
			++matches;
		nf_ct_put(found_ct);
	}

	rcu_read_unlock();

	return matches;
}

static bool add_hlist(struct hlist_head *head,
		      const struct nf_conntrack_tuple *tuple,
		      const union nf_inet_addr *addr)
{
	struct xt_connlimit_conn *conn;

	conn = kmem_cache_alloc(connlimit_conn_cachep, GFP_ATOMIC);
	if (conn == NULL)
		return false;
	conn->tuple = *tuple;
	conn->addr = *addr;
	hlist_add_head(&conn->node, head);
	return true;
}

static int count_them(struct net *net,
		      struct xt_connlimit_data *data,
		      const struct nf_conntrack_tuple *tuple,
		      const union nf_inet_addr *addr,
		      const union nf_inet_addr *mask,
		      u_int8_t family)
{
	struct hlist_head *hhead;
	int count;
	u32 hash;
	bool addit = true;

	if (family == NFPROTO_IPV6)
		hash = connlimit_iphash6(addr, mask);
	else
		hash = connlimit_iphash(addr->ip & mask->ip);

	hhead = &data->iphash[hash];

	spin_lock_bh(&data->lock);
	count = count_hlist(net, hhead, tuple, addr, mask, family, &addit);
	if (addit) {
		if (add_hlist(hhead, tuple, addr))
			count++;
		else
			count = -ENOMEM;
	}
	spin_unlock_bh(&data->lock);

	return count;
}

static bool
connlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
	struct net *net = dev_net(par->in ? par->in : par->out);
	const struct xt_connlimit_info *info = par->matchinfo;
	union nf_inet_addr addr;
	struct nf_conntrack_tuple tuple;
	const struct nf_conntrack_tuple *tuple_ptr = &tuple;
	enum ip_conntrack_info ctinfo;
	const struct nf_conn *ct;
	int connections;

	ct = nf_ct_get(skb, &ctinfo);
	if (ct != NULL)
		tuple_ptr = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
	else if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
				    par->family, &tuple))
		goto hotdrop;

	if (par->family == NFPROTO_IPV6) {
		const struct ipv6hdr *iph = ipv6_hdr(skb);
		memcpy(&addr.ip6, (info->flags & XT_CONNLIMIT_DADDR) ?
		       &iph->daddr : &iph->saddr, sizeof(addr.ip6));
	} else {
		const struct iphdr *iph = ip_hdr(skb);
		addr.ip = (info->flags & XT_CONNLIMIT_DADDR) ?
			  iph->daddr : iph->saddr;
	}

	connections = count_them(net, info->data, tuple_ptr, &addr,
	                         &info->mask, par->family);

	if (connections < 0)
		/* kmalloc failed, drop it entirely */
		goto hotdrop;

	return (connections > info->limit) ^
	       !!(info->flags & XT_CONNLIMIT_INVERT);

 hotdrop:
	par->hotdrop = true;
	return false;
}

static int connlimit_mt_check(const struct xt_mtchk_param *par)
{
	struct xt_connlimit_info *info = par->matchinfo;
	unsigned int i;
	int ret;

	if (unlikely(!connlimit_rnd)) {
		u_int32_t rand;

		do {
			get_random_bytes(&rand, sizeof(rand));
		} while (!rand);
		cmpxchg(&connlimit_rnd, 0, rand);
	}
	ret = nf_ct_l3proto_try_module_get(par->family);
	if (ret < 0) {
		pr_info("cannot load conntrack support for "
			"address family %u\n", par->family);
		return ret;
	}

	/* init private data */
	info->data = kmalloc(sizeof(struct xt_connlimit_data), GFP_KERNEL);
	if (info->data == NULL) {
		nf_ct_l3proto_module_put(par->family);
		return -ENOMEM;
	}

	spin_lock_init(&info->data->lock);
	for (i = 0; i < ARRAY_SIZE(info->data->iphash); ++i)
		INIT_HLIST_HEAD(&info->data->iphash[i]);

	return 0;
}

static void connlimit_mt_destroy(const struct xt_mtdtor_param *par)
{
	const struct xt_connlimit_info *info = par->matchinfo;
	struct xt_connlimit_conn *conn;
	struct hlist_node *n;
	struct hlist_head *hash = info->data->iphash;
	unsigned int i;

	nf_ct_l3proto_module_put(par->family);

	for (i = 0; i < ARRAY_SIZE(info->data->iphash); ++i) {
		hlist_for_each_entry_safe(conn, n, &hash[i], node) {
			hlist_del(&conn->node);
			kmem_cache_free(connlimit_conn_cachep, conn);
		}
	}

	kfree(info->data);
}

static struct xt_match connlimit_mt_reg __read_mostly = {
	.name       = "connlimit",
	.revision   = 1,
	.family     = NFPROTO_UNSPEC,
	.checkentry = connlimit_mt_check,
	.match      = connlimit_mt,
	.matchsize  = sizeof(struct xt_connlimit_info),
	.destroy    = connlimit_mt_destroy,
	.me         = THIS_MODULE,
};

static int __init connlimit_mt_init(void)
{
	int ret;
	connlimit_conn_cachep = kmem_cache_create("xt_connlimit_conn",
					   sizeof(struct xt_connlimit_conn),
					   0, 0, NULL);
	if (!connlimit_conn_cachep)
		return -ENOMEM;

	ret = xt_register_match(&connlimit_mt_reg);
	if (ret != 0)
		kmem_cache_destroy(connlimit_conn_cachep);
	return ret;
}

static void __exit connlimit_mt_exit(void)
{
	xt_unregister_match(&connlimit_mt_reg);
	kmem_cache_destroy(connlimit_conn_cachep);
}

module_init(connlimit_mt_init);
module_exit(connlimit_mt_exit);
MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
MODULE_DESCRIPTION("Xtables: Number of connections matching");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_connlimit");
MODULE_ALIAS("ip6t_connlimit");
Commit	Line	Data
370786f9 JE	1	/*
	2	* netfilter module to limit the number of parallel tcp
	3	* connections per IP address.
	4	* (c) 2000 Gerd Knorr <kraxel@bytesex.org>
	5	* Nov 2002: Martin Bene <martin.bene@icomedias.com>:
	6	* only ignore TIME_WAIT or gone connections
ba5dc275	7	* (C) CC Computer Consultants GmbH, 2007
370786f9 JE	8	*
	9	* based on ...
	10	*
	11	* Kernel module to match connection tracking information.
	12	* GPL (C) 1999 Rusty Russell (rusty@rustcorp.com.au).
	13	*/
8bee4bad	14	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
370786f9 JE	15	#include <linux/in.h>
	16	#include <linux/in6.h>
	17	#include <linux/ip.h>
	18	#include <linux/ipv6.h>
	19	#include <linux/jhash.h>
5a0e3ad6	20	#include <linux/slab.h>
370786f9 JE	21	#include <linux/list.h>
	22	#include <linux/module.h>
	23	#include <linux/random.h>
	24	#include <linux/skbuff.h>
	25	#include <linux/spinlock.h>
	26	#include <linux/netfilter/nf_conntrack_tcp.h>
	27	#include <linux/netfilter/x_tables.h>
	28	#include <linux/netfilter/xt_connlimit.h>
	29	#include <net/netfilter/nf_conntrack.h>
	30	#include <net/netfilter/nf_conntrack_core.h>
	31	#include <net/netfilter/nf_conntrack_tuple.h>
5d0aa2cc	32	#include <net/netfilter/nf_conntrack_zones.h>
370786f9 JE	33
	34	/* we will save the tuples of all connections we care about */
	35	struct xt_connlimit_conn {
3e0d5149	36	struct hlist_node node;
8183e3a8 CG	37	struct nf_conntrack_tuple tuple;
8183e3a8 CG	38	union nf_inet_addr addr;
370786f9 JE	39	};
	40
	41	struct xt_connlimit_data {
3e0d5149 CG	42	struct hlist_head iphash[256];
3e0d5149 CG	43	spinlock_t lock;
370786f9 JE	44	};
370786f9 JE	45
294188ae	46	static u_int32_t connlimit_rnd __read_mostly;
14e1a977	47	static struct kmem_cache *connlimit_conn_cachep __read_mostly;
370786f9	48
a34c4589	49	static inline unsigned int connlimit_iphash(__be32 addr)
370786f9	50	{
a34c4589	51	return jhash_1word((__force __u32)addr, connlimit_rnd) & 0xFF;
370786f9 JE	52	}
	53
	54	static inline unsigned int
643a2c15 JE	55	connlimit_iphash6(const union nf_inet_addr *addr,
643a2c15 JE	56	const union nf_inet_addr *mask)
370786f9	57	{
643a2c15	58	union nf_inet_addr res;
370786f9 JE	59	unsigned int i;
370786f9 JE	60
370786f9 JE	61	for (i = 0; i < ARRAY_SIZE(addr->ip6); ++i)
	62	res.ip6[i] = addr->ip6[i] & mask->ip6[i];
	63
a34c4589	64	return jhash2((u32 *)res.ip6, ARRAY_SIZE(res.ip6), connlimit_rnd) & 0xFF;
370786f9 JE	65	}
	66
	67	static inline bool already_closed(const struct nf_conn *conn)
	68	{
5e8fbe2a	69	if (nf_ct_protonum(conn) == IPPROTO_TCP)
d2ee3f2c DW	70	return conn->proto.tcp.state == TCP_CONNTRACK_TIME_WAIT \|\|
d2ee3f2c DW	71	conn->proto.tcp.state == TCP_CONNTRACK_CLOSE;
370786f9 JE	72	else
	73	return 0;
	74	}
	75
	76	static inline unsigned int
643a2c15 JE	77	same_source_net(const union nf_inet_addr *addr,
643a2c15 JE	78	const union nf_inet_addr *mask,
76108cea	79	const union nf_inet_addr *u3, u_int8_t family)
370786f9	80	{
ee999d8b	81	if (family == NFPROTO_IPV4) {
370786f9 JE	82	return (addr->ip & mask->ip) == (u3->ip & mask->ip);
370786f9 JE	83	} else {
643a2c15	84	union nf_inet_addr lh, rh;
370786f9 JE	85	unsigned int i;
	86
	87	for (i = 0; i < ARRAY_SIZE(addr->ip6); ++i) {
	88	lh.ip6[i] = addr->ip6[i] & mask->ip6[i];
	89	rh.ip6[i] = u3->ip6[i] & mask->ip6[i];
	90	}
	91
	92	return memcmp(&lh.ip6, &rh.ip6, sizeof(lh.ip6)) == 0;
	93	}
	94	}
	95
15cfd528 FW	96	static int count_hlist(struct net *net,
	97	struct hlist_head *head,
	98	const struct nf_conntrack_tuple *tuple,
	99	const union nf_inet_addr *addr,
	100	const union nf_inet_addr *mask,
3bcc5fdf	101	u_int8_t family, bool *addit)
370786f9	102	{
3cf93c96	103	const struct nf_conntrack_tuple_hash *found;
370786f9	104	struct xt_connlimit_conn *conn;
b67bfe0d	105	struct hlist_node *n;
ea781f19	106	struct nf_conn *found_ct;
370786f9 JE	107	int matches = 0;
370786f9 JE	108
76507f69	109	rcu_read_lock();
370786f9 JE	110
370786f9 JE	111	/* check the saved connections */
15cfd528	112	hlist_for_each_entry_safe(conn, n, head, node) {
5d0aa2cc PM	113	found = nf_conntrack_find_get(net, NF_CT_DEFAULT_ZONE,
5d0aa2cc PM	114	&conn->tuple);
d9ec4f1e FW	115	if (found == NULL) {
d9ec4f1e FW	116	hlist_del(&conn->node);
14e1a977	117	kmem_cache_free(connlimit_conn_cachep, conn);
d9ec4f1e FW	118	continue;
d9ec4f1e FW	119	}
370786f9	120
d9ec4f1e	121	found_ct = nf_ct_tuplehash_to_ctrack(found);
370786f9	122
d9ec4f1e	123	if (nf_ct_tuple_equal(&conn->tuple, tuple)) {
370786f9 JE	124	/*
	125	* Just to be sure we have it only once in the list.
	126	* We should not see tuples twice unless someone hooks
	127	* this into a table without "-p tcp --syn".
	128	*/
3bcc5fdf	129	*addit = false;
d9ec4f1e	130	} else if (already_closed(found_ct)) {
370786f9 JE	131	/*
	132	* we do not care about connections which are
	133	* closed already -> ditch it
	134	*/
ea781f19	135	nf_ct_put(found_ct);
3e0d5149	136	hlist_del(&conn->node);
14e1a977	137	kmem_cache_free(connlimit_conn_cachep, conn);
370786f9 JE	138	continue;
	139	}
	140
8183e3a8	141	if (same_source_net(addr, mask, &conn->addr, family))
370786f9 JE	142	/* same source network -> be counted! */
370786f9 JE	143	++matches;
ea781f19	144	nf_ct_put(found_ct);
370786f9 JE	145	}
370786f9 JE	146
76507f69	147	rcu_read_unlock();
370786f9	148
370786f9 JE	149	return matches;
	150	}
	151
3bcc5fdf FW	152	static bool add_hlist(struct hlist_head *head,
	153	const struct nf_conntrack_tuple *tuple,
	154	const union nf_inet_addr *addr)
	155	{
14e1a977 FW	156	struct xt_connlimit_conn *conn;
	157
	158	conn = kmem_cache_alloc(connlimit_conn_cachep, GFP_ATOMIC);
3bcc5fdf FW	159	if (conn == NULL)
	160	return false;
	161	conn->tuple = *tuple;
	162	conn->addr = *addr;
	163	hlist_add_head(&conn->node, head);
	164	return true;
	165	}
	166
15cfd528 FW	167	static int count_them(struct net *net,
	168	struct xt_connlimit_data *data,
	169	const struct nf_conntrack_tuple *tuple,
	170	const union nf_inet_addr *addr,
	171	const union nf_inet_addr *mask,
	172	u_int8_t family)
	173	{
	174	struct hlist_head *hhead;
	175	int count;
	176	u32 hash;
3bcc5fdf	177	bool addit = true;
15cfd528 FW	178
	179	if (family == NFPROTO_IPV6)
	180	hash = connlimit_iphash6(addr, mask);
	181	else
	182	hash = connlimit_iphash(addr->ip & mask->ip);
	183
	184	hhead = &data->iphash[hash];
	185
	186	spin_lock_bh(&data->lock);
3bcc5fdf FW	187	count = count_hlist(net, hhead, tuple, addr, mask, family, &addit);
	188	if (addit) {
	189	if (add_hlist(hhead, tuple, addr))
	190	count++;
	191	else
	192	count = -ENOMEM;
	193	}
15cfd528 FW	194	spin_unlock_bh(&data->lock);
	195
	196	return count;
	197	}
	198
d3c5ee6d	199	static bool
62fc8051	200	connlimit_mt(const struct sk_buff skb, struct xt_action_param par)
370786f9	201	{
83fc8102	202	struct net *net = dev_net(par->in ? par->in : par->out);
f7108a20	203	const struct xt_connlimit_info *info = par->matchinfo;
22c2d8bc	204	union nf_inet_addr addr;
370786f9 JE	205	struct nf_conntrack_tuple tuple;
	206	const struct nf_conntrack_tuple *tuple_ptr = &tuple;
	207	enum ip_conntrack_info ctinfo;
	208	const struct nf_conn *ct;
	209	int connections;
	210
	211	ct = nf_ct_get(skb, &ctinfo);
8183e3a8 CG	212	if (ct != NULL)
	213	tuple_ptr = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
	214	else if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
	215	par->family, &tuple))
370786f9 JE	216	goto hotdrop;
370786f9 JE	217
92f3b2b1	218	if (par->family == NFPROTO_IPV6) {
370786f9	219	const struct ipv6hdr *iph = ipv6_hdr(skb);
cc4fc022 JE	220	memcpy(&addr.ip6, (info->flags & XT_CONNLIMIT_DADDR) ?
cc4fc022 JE	221	&iph->daddr : &iph->saddr, sizeof(addr.ip6));
370786f9 JE	222	} else {
370786f9 JE	223	const struct iphdr *iph = ip_hdr(skb);
cc4fc022 JE	224	addr.ip = (info->flags & XT_CONNLIMIT_DADDR) ?
cc4fc022 JE	225	iph->daddr : iph->saddr;
370786f9 JE	226	}
370786f9 JE	227
83fc8102	228	connections = count_them(net, info->data, tuple_ptr, &addr,
20b7975e	229	&info->mask, par->family);
370786f9	230
1cc34c30	231	if (connections < 0)
370786f9	232	/* kmalloc failed, drop it entirely */
1cc34c30	233	goto hotdrop;
370786f9	234
cc4fc022 JE	235	return (connections > info->limit) ^
cc4fc022 JE	236	!!(info->flags & XT_CONNLIMIT_INVERT);
370786f9 JE	237
370786f9 JE	238	hotdrop:
b4ba2611	239	par->hotdrop = true;
370786f9 JE	240	return false;
	241	}
	242
b0f38452	243	static int connlimit_mt_check(const struct xt_mtchk_param *par)
370786f9	244	{
9b4fce7a	245	struct xt_connlimit_info *info = par->matchinfo;
370786f9	246	unsigned int i;
4a5a5c73	247	int ret;
370786f9	248
4656c4d6 CG	249	if (unlikely(!connlimit_rnd)) {
	250	u_int32_t rand;
	251
	252	do {
	253	get_random_bytes(&rand, sizeof(rand));
	254	} while (!rand);
	255	cmpxchg(&connlimit_rnd, 0, rand);
294188ae	256	}
4a5a5c73 JE	257	ret = nf_ct_l3proto_try_module_get(par->family);
4a5a5c73 JE	258	if (ret < 0) {
8bee4bad JE	259	pr_info("cannot load conntrack support for "
8bee4bad JE	260	"address family %u\n", par->family);
4a5a5c73	261	return ret;
370786f9 JE	262	}
	263
	264	/* init private data */
	265	info->data = kmalloc(sizeof(struct xt_connlimit_data), GFP_KERNEL);
	266	if (info->data == NULL) {
92f3b2b1	267	nf_ct_l3proto_module_put(par->family);
4a5a5c73	268	return -ENOMEM;
370786f9 JE	269	}
	270
	271	spin_lock_init(&info->data->lock);
	272	for (i = 0; i < ARRAY_SIZE(info->data->iphash); ++i)
3e0d5149	273	INIT_HLIST_HEAD(&info->data->iphash[i]);
370786f9	274
bd414ee6	275	return 0;
370786f9 JE	276	}
370786f9 JE	277
6be3d859	278	static void connlimit_mt_destroy(const struct xt_mtdtor_param *par)
370786f9	279	{
6be3d859	280	const struct xt_connlimit_info *info = par->matchinfo;
370786f9	281	struct xt_connlimit_conn *conn;
b67bfe0d	282	struct hlist_node *n;
3e0d5149	283	struct hlist_head *hash = info->data->iphash;
370786f9 JE	284	unsigned int i;
370786f9 JE	285
92f3b2b1	286	nf_ct_l3proto_module_put(par->family);
370786f9 JE	287
370786f9 JE	288	for (i = 0; i < ARRAY_SIZE(info->data->iphash); ++i) {
b67bfe0d	289	hlist_for_each_entry_safe(conn, n, &hash[i], node) {
3e0d5149	290	hlist_del(&conn->node);
14e1a977	291	kmem_cache_free(connlimit_conn_cachep, conn);
370786f9 JE	292	}
	293	}
	294
	295	kfree(info->data);
	296	}
	297
68c07cb6 CW	298	static struct xt_match connlimit_mt_reg __read_mostly = {
	299	.name = "connlimit",
	300	.revision = 1,
	301	.family = NFPROTO_UNSPEC,
	302	.checkentry = connlimit_mt_check,
	303	.match = connlimit_mt,
	304	.matchsize = sizeof(struct xt_connlimit_info),
	305	.destroy = connlimit_mt_destroy,
	306	.me = THIS_MODULE,
370786f9 JE	307	};
370786f9 JE	308
d3c5ee6d	309	static int __init connlimit_mt_init(void)
370786f9	310	{
14e1a977 FW	311	int ret;
	312	connlimit_conn_cachep = kmem_cache_create("xt_connlimit_conn",
	313	sizeof(struct xt_connlimit_conn),
	314	0, 0, NULL);
	315	if (!connlimit_conn_cachep)
	316	return -ENOMEM;
	317
	318	ret = xt_register_match(&connlimit_mt_reg);
	319	if (ret != 0)
	320	kmem_cache_destroy(connlimit_conn_cachep);
	321	return ret;
370786f9 JE	322	}
370786f9 JE	323
d3c5ee6d	324	static void __exit connlimit_mt_exit(void)
370786f9	325	{
68c07cb6	326	xt_unregister_match(&connlimit_mt_reg);
14e1a977	327	kmem_cache_destroy(connlimit_conn_cachep);
370786f9 JE	328	}
370786f9 JE	329
d3c5ee6d JE	330	module_init(connlimit_mt_init);
d3c5ee6d JE	331	module_exit(connlimit_mt_exit);
92f3b2b1	332	MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
2ae15b64	333	MODULE_DESCRIPTION("Xtables: Number of connections matching");
370786f9 JE	334	MODULE_LICENSE("GPL");
	335	MODULE_ALIAS("ipt_connlimit");
	336	MODULE_ALIAS("ip6t_connlimit");