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