[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>

#define CONNLIMIT_SLOTS	256
#define CONNLIMIT_LOCK_SLOTS	32

/* 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[CONNLIMIT_SLOTS];
	spinlock_t		locks[CONNLIMIT_LOCK_SLOTS];
};

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) % CONNLIMIT_SLOTS;
}

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) % CONNLIMIT_SLOTS;
}

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 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 ntohl(addr->ip & mask->ip) -
		       ntohl(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));
	}
}

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) == 0)
			/* 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->locks[hash % CONNLIMIT_LOCK_SLOTS]);
	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->locks[hash % CONNLIMIT_LOCK_SLOTS]);

	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;
	}

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

	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;

	BUILD_BUG_ON(CONNLIMIT_LOCK_SLOTS > CONNLIMIT_SLOTS);
	BUILD_BUG_ON((CONNLIMIT_SLOTS % CONNLIMIT_LOCK_SLOTS) != 0);

	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	33
1442e750 FW	34	#define CONNLIMIT_SLOTS 256
	35	#define CONNLIMIT_LOCK_SLOTS 32
	36
370786f9 JE	37	/* we will save the tuples of all connections we care about */
370786f9 JE	38	struct xt_connlimit_conn {
3e0d5149	39	struct hlist_node node;
8183e3a8 CG	40	struct nf_conntrack_tuple tuple;
8183e3a8 CG	41	union nf_inet_addr addr;
370786f9 JE	42	};
	43
	44	struct xt_connlimit_data {
1442e750 FW	45	struct hlist_head iphash[CONNLIMIT_SLOTS];
1442e750 FW	46	spinlock_t locks[CONNLIMIT_LOCK_SLOTS];
370786f9 JE	47	};
370786f9 JE	48
294188ae	49	static u_int32_t connlimit_rnd __read_mostly;
14e1a977	50	static struct kmem_cache *connlimit_conn_cachep __read_mostly;
370786f9	51
a34c4589	52	static inline unsigned int connlimit_iphash(__be32 addr)
370786f9	53	{
1442e750 FW	54	return jhash_1word((__force __u32)addr,
1442e750 FW	55	connlimit_rnd) % CONNLIMIT_SLOTS;
370786f9 JE	56	}
	57
	58	static inline unsigned int
643a2c15 JE	59	connlimit_iphash6(const union nf_inet_addr *addr,
643a2c15 JE	60	const union nf_inet_addr *mask)
370786f9	61	{
643a2c15	62	union nf_inet_addr res;
370786f9 JE	63	unsigned int i;
370786f9 JE	64
370786f9 JE	65	for (i = 0; i < ARRAY_SIZE(addr->ip6); ++i)
	66	res.ip6[i] = addr->ip6[i] & mask->ip6[i];
	67
1442e750 FW	68	return jhash2((u32 *)res.ip6, ARRAY_SIZE(res.ip6),
1442e750 FW	69	connlimit_rnd) % CONNLIMIT_SLOTS;
370786f9 JE	70	}
	71
	72	static inline bool already_closed(const struct nf_conn *conn)
	73	{
5e8fbe2a	74	if (nf_ct_protonum(conn) == IPPROTO_TCP)
d2ee3f2c DW	75	return conn->proto.tcp.state == TCP_CONNTRACK_TIME_WAIT \|\|
d2ee3f2c DW	76	conn->proto.tcp.state == TCP_CONNTRACK_CLOSE;
370786f9 JE	77	else
	78	return 0;
	79	}
	80
50e0e9b1	81	static int
643a2c15 JE	82	same_source_net(const union nf_inet_addr *addr,
643a2c15 JE	83	const union nf_inet_addr *mask,
76108cea	84	const union nf_inet_addr *u3, u_int8_t family)
370786f9	85	{
ee999d8b	86	if (family == NFPROTO_IPV4) {
50e0e9b1 FW	87	return ntohl(addr->ip & mask->ip) -
50e0e9b1 FW	88	ntohl(u3->ip & mask->ip);
370786f9	89	} else {
643a2c15	90	union nf_inet_addr lh, rh;
370786f9 JE	91	unsigned int i;
	92
	93	for (i = 0; i < ARRAY_SIZE(addr->ip6); ++i) {
	94	lh.ip6[i] = addr->ip6[i] & mask->ip6[i];
	95	rh.ip6[i] = u3->ip6[i] & mask->ip6[i];
	96	}
	97
50e0e9b1	98	return memcmp(&lh.ip6, &rh.ip6, sizeof(lh.ip6));
370786f9 JE	99	}
	100	}
	101
15cfd528 FW	102	static int count_hlist(struct net *net,
	103	struct hlist_head *head,
	104	const struct nf_conntrack_tuple *tuple,
	105	const union nf_inet_addr *addr,
	106	const union nf_inet_addr *mask,
3bcc5fdf	107	u_int8_t family, bool *addit)
370786f9	108	{
3cf93c96	109	const struct nf_conntrack_tuple_hash *found;
370786f9	110	struct xt_connlimit_conn *conn;
b67bfe0d	111	struct hlist_node *n;
ea781f19	112	struct nf_conn *found_ct;
370786f9 JE	113	int matches = 0;
370786f9 JE	114
76507f69	115	rcu_read_lock();
370786f9 JE	116
370786f9 JE	117	/* check the saved connections */
15cfd528	118	hlist_for_each_entry_safe(conn, n, head, node) {
5d0aa2cc PM	119	found = nf_conntrack_find_get(net, NF_CT_DEFAULT_ZONE,
5d0aa2cc PM	120	&conn->tuple);
d9ec4f1e FW	121	if (found == NULL) {
d9ec4f1e FW	122	hlist_del(&conn->node);
14e1a977	123	kmem_cache_free(connlimit_conn_cachep, conn);
d9ec4f1e FW	124	continue;
d9ec4f1e FW	125	}
370786f9	126
d9ec4f1e	127	found_ct = nf_ct_tuplehash_to_ctrack(found);
370786f9	128
d9ec4f1e	129	if (nf_ct_tuple_equal(&conn->tuple, tuple)) {
370786f9 JE	130	/*
	131	* Just to be sure we have it only once in the list.
	132	* We should not see tuples twice unless someone hooks
	133	* this into a table without "-p tcp --syn".
	134	*/
3bcc5fdf	135	*addit = false;
d9ec4f1e	136	} else if (already_closed(found_ct)) {
370786f9 JE	137	/*
	138	* we do not care about connections which are
	139	* closed already -> ditch it
	140	*/
ea781f19	141	nf_ct_put(found_ct);
3e0d5149	142	hlist_del(&conn->node);
14e1a977	143	kmem_cache_free(connlimit_conn_cachep, conn);
370786f9 JE	144	continue;
	145	}
	146
50e0e9b1	147	if (same_source_net(addr, mask, &conn->addr, family) == 0)
370786f9 JE	148	/* same source network -> be counted! */
370786f9 JE	149	++matches;
ea781f19	150	nf_ct_put(found_ct);
370786f9 JE	151	}
370786f9 JE	152
76507f69	153	rcu_read_unlock();
370786f9	154
370786f9 JE	155	return matches;
	156	}
	157
3bcc5fdf FW	158	static bool add_hlist(struct hlist_head *head,
	159	const struct nf_conntrack_tuple *tuple,
	160	const union nf_inet_addr *addr)
	161	{
14e1a977 FW	162	struct xt_connlimit_conn *conn;
	163
	164	conn = kmem_cache_alloc(connlimit_conn_cachep, GFP_ATOMIC);
3bcc5fdf FW	165	if (conn == NULL)
	166	return false;
	167	conn->tuple = *tuple;
	168	conn->addr = *addr;
	169	hlist_add_head(&conn->node, head);
	170	return true;
	171	}
	172
15cfd528 FW	173	static int count_them(struct net *net,
	174	struct xt_connlimit_data *data,
	175	const struct nf_conntrack_tuple *tuple,
	176	const union nf_inet_addr *addr,
	177	const union nf_inet_addr *mask,
	178	u_int8_t family)
	179	{
	180	struct hlist_head *hhead;
	181	int count;
	182	u32 hash;
3bcc5fdf	183	bool addit = true;
15cfd528 FW	184
	185	if (family == NFPROTO_IPV6)
	186	hash = connlimit_iphash6(addr, mask);
	187	else
	188	hash = connlimit_iphash(addr->ip & mask->ip);
	189
	190	hhead = &data->iphash[hash];
	191
1442e750	192	spin_lock_bh(&data->locks[hash % CONNLIMIT_LOCK_SLOTS]);
3bcc5fdf FW	193	count = count_hlist(net, hhead, tuple, addr, mask, family, &addit);
	194	if (addit) {
	195	if (add_hlist(hhead, tuple, addr))
	196	count++;
	197	else
	198	count = -ENOMEM;
	199	}
1442e750	200	spin_unlock_bh(&data->locks[hash % CONNLIMIT_LOCK_SLOTS]);
15cfd528 FW	201
	202	return count;
	203	}
	204
d3c5ee6d	205	static bool
62fc8051	206	connlimit_mt(const struct sk_buff skb, struct xt_action_param par)
370786f9	207	{
83fc8102	208	struct net *net = dev_net(par->in ? par->in : par->out);
f7108a20	209	const struct xt_connlimit_info *info = par->matchinfo;
22c2d8bc	210	union nf_inet_addr addr;
370786f9 JE	211	struct nf_conntrack_tuple tuple;
	212	const struct nf_conntrack_tuple *tuple_ptr = &tuple;
	213	enum ip_conntrack_info ctinfo;
	214	const struct nf_conn *ct;
	215	int connections;
	216
	217	ct = nf_ct_get(skb, &ctinfo);
8183e3a8 CG	218	if (ct != NULL)
	219	tuple_ptr = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
	220	else if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
	221	par->family, &tuple))
370786f9 JE	222	goto hotdrop;
370786f9 JE	223
92f3b2b1	224	if (par->family == NFPROTO_IPV6) {
370786f9	225	const struct ipv6hdr *iph = ipv6_hdr(skb);
cc4fc022 JE	226	memcpy(&addr.ip6, (info->flags & XT_CONNLIMIT_DADDR) ?
cc4fc022 JE	227	&iph->daddr : &iph->saddr, sizeof(addr.ip6));
370786f9 JE	228	} else {
370786f9 JE	229	const struct iphdr *iph = ip_hdr(skb);
cc4fc022 JE	230	addr.ip = (info->flags & XT_CONNLIMIT_DADDR) ?
cc4fc022 JE	231	iph->daddr : iph->saddr;
370786f9 JE	232	}
370786f9 JE	233
83fc8102	234	connections = count_them(net, info->data, tuple_ptr, &addr,
20b7975e	235	&info->mask, par->family);
1cc34c30	236	if (connections < 0)
370786f9	237	/* kmalloc failed, drop it entirely */
1cc34c30	238	goto hotdrop;
370786f9	239
cc4fc022 JE	240	return (connections > info->limit) ^
cc4fc022 JE	241	!!(info->flags & XT_CONNLIMIT_INVERT);
370786f9 JE	242
370786f9 JE	243	hotdrop:
b4ba2611	244	par->hotdrop = true;
370786f9 JE	245	return false;
	246	}
	247
b0f38452	248	static int connlimit_mt_check(const struct xt_mtchk_param *par)
370786f9	249	{
9b4fce7a	250	struct xt_connlimit_info *info = par->matchinfo;
370786f9	251	unsigned int i;
4a5a5c73	252	int ret;
370786f9	253
4656c4d6 CG	254	if (unlikely(!connlimit_rnd)) {
	255	u_int32_t rand;
	256
	257	do {
	258	get_random_bytes(&rand, sizeof(rand));
	259	} while (!rand);
	260	cmpxchg(&connlimit_rnd, 0, rand);
294188ae	261	}
4a5a5c73 JE	262	ret = nf_ct_l3proto_try_module_get(par->family);
4a5a5c73 JE	263	if (ret < 0) {
8bee4bad JE	264	pr_info("cannot load conntrack support for "
8bee4bad JE	265	"address family %u\n", par->family);
4a5a5c73	266	return ret;
370786f9 JE	267	}
	268
	269	/* init private data */
	270	info->data = kmalloc(sizeof(struct xt_connlimit_data), GFP_KERNEL);
	271	if (info->data == NULL) {
92f3b2b1	272	nf_ct_l3proto_module_put(par->family);
4a5a5c73	273	return -ENOMEM;
370786f9 JE	274	}
370786f9 JE	275
1442e750 FW	276	for (i = 0; i < ARRAY_SIZE(info->data->locks); ++i)
	277	spin_lock_init(&info->data->locks[i]);
	278
370786f9	279	for (i = 0; i < ARRAY_SIZE(info->data->iphash); ++i)
3e0d5149	280	INIT_HLIST_HEAD(&info->data->iphash[i]);
370786f9	281
bd414ee6	282	return 0;
370786f9 JE	283	}
370786f9 JE	284
6be3d859	285	static void connlimit_mt_destroy(const struct xt_mtdtor_param *par)
370786f9	286	{
6be3d859	287	const struct xt_connlimit_info *info = par->matchinfo;
370786f9	288	struct xt_connlimit_conn *conn;
b67bfe0d	289	struct hlist_node *n;
3e0d5149	290	struct hlist_head *hash = info->data->iphash;
370786f9 JE	291	unsigned int i;
370786f9 JE	292
92f3b2b1	293	nf_ct_l3proto_module_put(par->family);
370786f9 JE	294
370786f9 JE	295	for (i = 0; i < ARRAY_SIZE(info->data->iphash); ++i) {
b67bfe0d	296	hlist_for_each_entry_safe(conn, n, &hash[i], node) {
3e0d5149	297	hlist_del(&conn->node);
14e1a977	298	kmem_cache_free(connlimit_conn_cachep, conn);
370786f9 JE	299	}
	300	}
	301
	302	kfree(info->data);
	303	}
	304
68c07cb6 CW	305	static struct xt_match connlimit_mt_reg __read_mostly = {
	306	.name = "connlimit",
	307	.revision = 1,
	308	.family = NFPROTO_UNSPEC,
	309	.checkentry = connlimit_mt_check,
	310	.match = connlimit_mt,
	311	.matchsize = sizeof(struct xt_connlimit_info),
	312	.destroy = connlimit_mt_destroy,
	313	.me = THIS_MODULE,
370786f9 JE	314	};
370786f9 JE	315
d3c5ee6d	316	static int __init connlimit_mt_init(void)
370786f9	317	{
14e1a977	318	int ret;
1442e750 FW	319
	320	BUILD_BUG_ON(CONNLIMIT_LOCK_SLOTS > CONNLIMIT_SLOTS);
	321	BUILD_BUG_ON((CONNLIMIT_SLOTS % CONNLIMIT_LOCK_SLOTS) != 0);
	322
14e1a977 FW	323	connlimit_conn_cachep = kmem_cache_create("xt_connlimit_conn",
	324	sizeof(struct xt_connlimit_conn),
	325	0, 0, NULL);
	326	if (!connlimit_conn_cachep)
	327	return -ENOMEM;
	328
	329	ret = xt_register_match(&connlimit_mt_reg);
	330	if (ret != 0)
	331	kmem_cache_destroy(connlimit_conn_cachep);
	332	return ret;
370786f9 JE	333	}
370786f9 JE	334
d3c5ee6d	335	static void __exit connlimit_mt_exit(void)
370786f9	336	{
68c07cb6	337	xt_unregister_match(&connlimit_mt_reg);
14e1a977	338	kmem_cache_destroy(connlimit_conn_cachep);
370786f9 JE	339	}
370786f9 JE	340
d3c5ee6d JE	341	module_init(connlimit_mt_init);
d3c5ee6d JE	342	module_exit(connlimit_mt_exit);
92f3b2b1	343	MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
2ae15b64	344	MODULE_DESCRIPTION("Xtables: Number of connections matching");
370786f9 JE	345	MODULE_LICENSE("GPL");
	346	MODULE_ALIAS("ipt_connlimit");
	347	MODULE_ALIAS("ip6t_connlimit");