[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / netfilter / nfnetlink_acct.c

/*
 * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
 * (C) 2011 Intra2net AG <http://www.intra2net.com>
 *
 * 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 (or any later at your option).
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/atomic.h>
#include <linux/netlink.h>
#include <linux/rculist.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <net/netlink.h>
#include <net/sock.h>

#include <linux/netfilter.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_acct.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
MODULE_DESCRIPTION("nfacct: Extended Netfilter accounting infrastructure");

static LIST_HEAD(nfnl_acct_list);

struct nf_acct {
	atomic64_t		pkts;
	atomic64_t		bytes;
	struct list_head	head;
	atomic_t		refcnt;
	char			name[NFACCT_NAME_MAX];
	struct rcu_head		rcu_head;
};

static int
nfnl_acct_new(struct sock *nfnl, struct sk_buff *skb,
	     const struct nlmsghdr *nlh, const struct nlattr * const tb[])
{
	struct nf_acct *nfacct, *matching = NULL;
	char *acct_name;

	if (!tb[NFACCT_NAME])
		return -EINVAL;

	acct_name = nla_data(tb[NFACCT_NAME]);

	list_for_each_entry(nfacct, &nfnl_acct_list, head) {
		if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
			continue;

                if (nlh->nlmsg_flags & NLM_F_EXCL)
			return -EEXIST;

		matching = nfacct;
		break;
        }

	if (matching) {
		if (nlh->nlmsg_flags & NLM_F_REPLACE) {
			/* reset counters if you request a replacement. */
			atomic64_set(&matching->pkts, 0);
			atomic64_set(&matching->bytes, 0);
			return 0;
		}
		return -EBUSY;
	}

	nfacct = kzalloc(sizeof(struct nf_acct), GFP_KERNEL);
	if (nfacct == NULL)
		return -ENOMEM;

	strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);

	if (tb[NFACCT_BYTES]) {
		atomic64_set(&nfacct->bytes,
			     be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES])));
	}
	if (tb[NFACCT_PKTS]) {
		atomic64_set(&nfacct->pkts,
			     be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS])));
	}
	atomic_set(&nfacct->refcnt, 1);
	list_add_tail_rcu(&nfacct->head, &nfnl_acct_list);
	return 0;
}

static int
nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
		   int event, struct nf_acct *acct)
{
	struct nlmsghdr *nlh;
	struct nfgenmsg *nfmsg;
	unsigned int flags = portid ? NLM_F_MULTI : 0;
	u64 pkts, bytes;

	event |= NFNL_SUBSYS_ACCT << 8;
	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
	if (nlh == NULL)
		goto nlmsg_failure;

	nfmsg = nlmsg_data(nlh);
	nfmsg->nfgen_family = AF_UNSPEC;
	nfmsg->version = NFNETLINK_V0;
	nfmsg->res_id = 0;

	if (nla_put_string(skb, NFACCT_NAME, acct->name))
		goto nla_put_failure;

	if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
		pkts = atomic64_xchg(&acct->pkts, 0);
		bytes = atomic64_xchg(&acct->bytes, 0);
	} else {
		pkts = atomic64_read(&acct->pkts);
		bytes = atomic64_read(&acct->bytes);
	}
	if (nla_put_be64(skb, NFACCT_PKTS, cpu_to_be64(pkts)) ||
	    nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes)) ||
	    nla_put_be32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt))))
		goto nla_put_failure;

	nlmsg_end(skb, nlh);
	return skb->len;

nlmsg_failure:
nla_put_failure:
	nlmsg_cancel(skb, nlh);
	return -1;
}

static int
nfnl_acct_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct nf_acct *cur, *last;

	if (cb->args[2])
		return 0;

	last = (struct nf_acct *)cb->args[1];
	if (cb->args[1])
		cb->args[1] = 0;

	rcu_read_lock();
	list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
		if (last && cur != last)
			continue;

		if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid,
				       cb->nlh->nlmsg_seq,
				       NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
				       NFNL_MSG_ACCT_NEW, cur) < 0) {
			cb->args[1] = (unsigned long)cur;
			break;
		}
	}
	if (!cb->args[1])
		cb->args[2] = 1;
	rcu_read_unlock();
	return skb->len;
}

static int
nfnl_acct_get(struct sock *nfnl, struct sk_buff *skb,
	     const struct nlmsghdr *nlh, const struct nlattr * const tb[])
{
	int ret = -ENOENT;
	struct nf_acct *cur;
	char *acct_name;

	if (nlh->nlmsg_flags & NLM_F_DUMP) {
		struct netlink_dump_control c = {
			.dump = nfnl_acct_dump,
		};
		return netlink_dump_start(nfnl, skb, nlh, &c);
	}

	if (!tb[NFACCT_NAME])
		return -EINVAL;
	acct_name = nla_data(tb[NFACCT_NAME]);

	list_for_each_entry(cur, &nfnl_acct_list, head) {
		struct sk_buff *skb2;

		if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
			continue;

		skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
		if (skb2 == NULL) {
			ret = -ENOMEM;
			break;
		}

		ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid,
					 nlh->nlmsg_seq,
					 NFNL_MSG_TYPE(nlh->nlmsg_type),
					 NFNL_MSG_ACCT_NEW, cur);
		if (ret <= 0) {
			kfree_skb(skb2);
			break;
		}
		ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
					MSG_DONTWAIT);
		if (ret > 0)
			ret = 0;

		/* this avoids a loop in nfnetlink. */
		return ret == -EAGAIN ? -ENOBUFS : ret;
	}
	return ret;
}

/* try to delete object, fail if it is still in use. */
static int nfnl_acct_try_del(struct nf_acct *cur)
{
	int ret = 0;

	/* we want to avoid races with nfnl_acct_find_get. */
	if (atomic_dec_and_test(&cur->refcnt)) {
		/* We are protected by nfnl mutex. */
		list_del_rcu(&cur->head);
		kfree_rcu(cur, rcu_head);
	} else {
		/* still in use, restore reference counter. */
		atomic_inc(&cur->refcnt);
		ret = -EBUSY;
	}
	return ret;
}

static int
nfnl_acct_del(struct sock *nfnl, struct sk_buff *skb,
	     const struct nlmsghdr *nlh, const struct nlattr * const tb[])
{
	char *acct_name;
	struct nf_acct *cur;
	int ret = -ENOENT;

	if (!tb[NFACCT_NAME]) {
		list_for_each_entry(cur, &nfnl_acct_list, head)
			nfnl_acct_try_del(cur);

		return 0;
	}
	acct_name = nla_data(tb[NFACCT_NAME]);

	list_for_each_entry(cur, &nfnl_acct_list, head) {
		if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
			continue;

		ret = nfnl_acct_try_del(cur);
		if (ret < 0)
			return ret;

		break;
	}
	return ret;
}

static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
	[NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
	[NFACCT_BYTES] = { .type = NLA_U64 },
	[NFACCT_PKTS] = { .type = NLA_U64 },
};

static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
	[NFNL_MSG_ACCT_NEW]		= { .call = nfnl_acct_new,
					    .attr_count = NFACCT_MAX,
					    .policy = nfnl_acct_policy },
	[NFNL_MSG_ACCT_GET] 		= { .call = nfnl_acct_get,
					    .attr_count = NFACCT_MAX,
					    .policy = nfnl_acct_policy },
	[NFNL_MSG_ACCT_GET_CTRZERO] 	= { .call = nfnl_acct_get,
					    .attr_count = NFACCT_MAX,
					    .policy = nfnl_acct_policy },
	[NFNL_MSG_ACCT_DEL]		= { .call = nfnl_acct_del,
					    .attr_count = NFACCT_MAX,
					    .policy = nfnl_acct_policy },
};

static const struct nfnetlink_subsystem nfnl_acct_subsys = {
	.name				= "acct",
	.subsys_id			= NFNL_SUBSYS_ACCT,
	.cb_count			= NFNL_MSG_ACCT_MAX,
	.cb				= nfnl_acct_cb,
};

MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);

struct nf_acct *nfnl_acct_find_get(const char *acct_name)
{
	struct nf_acct *cur, *acct = NULL;

	rcu_read_lock();
	list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
		if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
			continue;

		if (!try_module_get(THIS_MODULE))
			goto err;

		if (!atomic_inc_not_zero(&cur->refcnt)) {
			module_put(THIS_MODULE);
			goto err;
		}

		acct = cur;
		break;
	}
err:
	rcu_read_unlock();
	return acct;
}
EXPORT_SYMBOL_GPL(nfnl_acct_find_get);

void nfnl_acct_put(struct nf_acct *acct)
{
	atomic_dec(&acct->refcnt);
	module_put(THIS_MODULE);
}
EXPORT_SYMBOL_GPL(nfnl_acct_put);

void nfnl_acct_update(const struct sk_buff *skb, struct nf_acct *nfacct)
{
	atomic64_inc(&nfacct->pkts);
	atomic64_add(skb->len, &nfacct->bytes);
}
EXPORT_SYMBOL_GPL(nfnl_acct_update);

static int __init nfnl_acct_init(void)
{
	int ret;

	pr_info("nfnl_acct: registering with nfnetlink.\n");
	ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
	if (ret < 0) {
		pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
		goto err_out;
	}
	return 0;
err_out:
	return ret;
}

static void __exit nfnl_acct_exit(void)
{
	struct nf_acct *cur, *tmp;

	pr_info("nfnl_acct: unregistering from nfnetlink.\n");
	nfnetlink_subsys_unregister(&nfnl_acct_subsys);

	list_for_each_entry_safe(cur, tmp, &nfnl_acct_list, head) {
		list_del_rcu(&cur->head);
		/* We are sure that our objects have no clients at this point,
		 * it's safe to release them all without checking refcnt. */
		kfree_rcu(cur, rcu_head);
	}
}

module_init(nfnl_acct_init);
module_exit(nfnl_acct_exit);
Commit	Line	Data
94139027 PNA	1	/*
	2	* (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
	3	* (C) 2011 Intra2net AG <http://www.intra2net.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation (or any later at your option).
	8	*/
	9	#include <linux/init.h>
	10	#include <linux/module.h>
	11	#include <linux/kernel.h>
	12	#include <linux/skbuff.h>
6523cf9a	13	#include <linux/atomic.h>
94139027 PNA	14	#include <linux/netlink.h>
	15	#include <linux/rculist.h>
	16	#include <linux/slab.h>
	17	#include <linux/types.h>
	18	#include <linux/errno.h>
	19	#include <net/netlink.h>
	20	#include <net/sock.h>
94139027 PNA	21
	22	#include <linux/netfilter.h>
	23	#include <linux/netfilter/nfnetlink.h>
	24	#include <linux/netfilter/nfnetlink_acct.h>
	25
	26	MODULE_LICENSE("GPL");
	27	MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
	28	MODULE_DESCRIPTION("nfacct: Extended Netfilter accounting infrastructure");
	29
	30	static LIST_HEAD(nfnl_acct_list);
	31
	32	struct nf_acct {
	33	atomic64_t pkts;
	34	atomic64_t bytes;
	35	struct list_head head;
	36	atomic_t refcnt;
	37	char name[NFACCT_NAME_MAX];
	38	struct rcu_head rcu_head;
	39	};
	40
	41	static int
	42	nfnl_acct_new(struct sock nfnl, struct sk_buff skb,
	43	const struct nlmsghdr nlh, const struct nlattr const tb[])
	44	{
	45	struct nf_acct nfacct, matching = NULL;
	46	char *acct_name;
	47
	48	if (!tb[NFACCT_NAME])
	49	return -EINVAL;
	50
	51	acct_name = nla_data(tb[NFACCT_NAME]);
	52
	53	list_for_each_entry(nfacct, &nfnl_acct_list, head) {
	54	if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
	55	continue;
	56
	57	if (nlh->nlmsg_flags & NLM_F_EXCL)
	58	return -EEXIST;
	59
	60	matching = nfacct;
	61	break;
	62	}
	63
	64	if (matching) {
	65	if (nlh->nlmsg_flags & NLM_F_REPLACE) {
	66	/* reset counters if you request a replacement. */
	67	atomic64_set(&matching->pkts, 0);
	68	atomic64_set(&matching->bytes, 0);
	69	return 0;
	70	}
	71	return -EBUSY;
	72	}
	73
	74	nfacct = kzalloc(sizeof(struct nf_acct), GFP_KERNEL);
	75	if (nfacct == NULL)
	76	return -ENOMEM;
	77
	78	strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
	79
	80	if (tb[NFACCT_BYTES]) {
	81	atomic64_set(&nfacct->bytes,
fe31d1a8	82	be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES])));
94139027 PNA	83	}
	84	if (tb[NFACCT_PKTS]) {
	85	atomic64_set(&nfacct->pkts,
fe31d1a8	86	be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS])));
94139027 PNA	87	}
	88	atomic_set(&nfacct->refcnt, 1);
	89	list_add_tail_rcu(&nfacct->head, &nfnl_acct_list);
	90	return 0;
	91	}
	92
	93	static int
15e47304	94	nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
94139027 PNA	95	int event, struct nf_acct *acct)
	96	{
	97	struct nlmsghdr *nlh;
	98	struct nfgenmsg *nfmsg;
15e47304	99	unsigned int flags = portid ? NLM_F_MULTI : 0;
94139027 PNA	100	u64 pkts, bytes;
	101
	102	event \|= NFNL_SUBSYS_ACCT << 8;
15e47304	103	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
94139027 PNA	104	if (nlh == NULL)
	105	goto nlmsg_failure;
	106
	107	nfmsg = nlmsg_data(nlh);
	108	nfmsg->nfgen_family = AF_UNSPEC;
	109	nfmsg->version = NFNETLINK_V0;
	110	nfmsg->res_id = 0;
	111
7c801189 DM	112	if (nla_put_string(skb, NFACCT_NAME, acct->name))
7c801189 DM	113	goto nla_put_failure;
94139027 PNA	114
	115	if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
	116	pkts = atomic64_xchg(&acct->pkts, 0);
	117	bytes = atomic64_xchg(&acct->bytes, 0);
	118	} else {
	119	pkts = atomic64_read(&acct->pkts);
	120	bytes = atomic64_read(&acct->bytes);
	121	}
7c801189 DM	122	if (nla_put_be64(skb, NFACCT_PKTS, cpu_to_be64(pkts)) \|\|
	123	nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes)) \|\|
	124	nla_put_be32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt))))
	125	goto nla_put_failure;
94139027 PNA	126
	127	nlmsg_end(skb, nlh);
	128	return skb->len;
	129
	130	nlmsg_failure:
	131	nla_put_failure:
	132	nlmsg_cancel(skb, nlh);
	133	return -1;
	134	}
	135
	136	static int
	137	nfnl_acct_dump(struct sk_buff skb, struct netlink_callback cb)
	138	{
	139	struct nf_acct cur, last;
	140
	141	if (cb->args[2])
	142	return 0;
	143
	144	last = (struct nf_acct *)cb->args[1];
	145	if (cb->args[1])
	146	cb->args[1] = 0;
	147
	148	rcu_read_lock();
	149	list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
	150	if (last && cur != last)
	151	continue;
	152
15e47304	153	if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid,
94139027 PNA	154	cb->nlh->nlmsg_seq,
	155	NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
	156	NFNL_MSG_ACCT_NEW, cur) < 0) {
	157	cb->args[1] = (unsigned long)cur;
	158	break;
	159	}
	160	}
	161	if (!cb->args[1])
	162	cb->args[2] = 1;
	163	rcu_read_unlock();
	164	return skb->len;
	165	}
	166
	167	static int
	168	nfnl_acct_get(struct sock nfnl, struct sk_buff skb,
	169	const struct nlmsghdr nlh, const struct nlattr const tb[])
	170	{
3ab0b245	171	int ret = -ENOENT;
94139027 PNA	172	struct nf_acct *cur;
	173	char *acct_name;
	174
	175	if (nlh->nlmsg_flags & NLM_F_DUMP) {
80d326fa PNA	176	struct netlink_dump_control c = {
	177	.dump = nfnl_acct_dump,
	178	};
	179	return netlink_dump_start(nfnl, skb, nlh, &c);
94139027 PNA	180	}
	181
	182	if (!tb[NFACCT_NAME])
	183	return -EINVAL;
	184	acct_name = nla_data(tb[NFACCT_NAME]);
	185
	186	list_for_each_entry(cur, &nfnl_acct_list, head) {
	187	struct sk_buff *skb2;
	188
	189	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
	190	continue;
	191
	192	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
3ab0b245 PNA	193	if (skb2 == NULL) {
3ab0b245 PNA	194	ret = -ENOMEM;
94139027	195	break;
3ab0b245	196	}
94139027	197
15e47304	198	ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid,
94139027 PNA	199	nlh->nlmsg_seq,
	200	NFNL_MSG_TYPE(nlh->nlmsg_type),
	201	NFNL_MSG_ACCT_NEW, cur);
3ab0b245	202	if (ret <= 0) {
94139027	203	kfree_skb(skb2);
3ab0b245 PNA	204	break;
3ab0b245 PNA	205	}
15e47304	206	ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
3ab0b245 PNA	207	MSG_DONTWAIT);
	208	if (ret > 0)
	209	ret = 0;
94139027	210
3ab0b245 PNA	211	/* this avoids a loop in nfnetlink. */
3ab0b245 PNA	212	return ret == -EAGAIN ? -ENOBUFS : ret;
94139027 PNA	213	}
	214	return ret;
	215	}
	216
	217	/* try to delete object, fail if it is still in use. */
	218	static int nfnl_acct_try_del(struct nf_acct *cur)
	219	{
	220	int ret = 0;
	221
	222	/* we want to avoid races with nfnl_acct_find_get. */
	223	if (atomic_dec_and_test(&cur->refcnt)) {
	224	/* We are protected by nfnl mutex. */
	225	list_del_rcu(&cur->head);
	226	kfree_rcu(cur, rcu_head);
	227	} else {
	228	/* still in use, restore reference counter. */
	229	atomic_inc(&cur->refcnt);
	230	ret = -EBUSY;
	231	}
	232	return ret;
	233	}
	234
	235	static int
	236	nfnl_acct_del(struct sock nfnl, struct sk_buff skb,
	237	const struct nlmsghdr nlh, const struct nlattr const tb[])
	238	{
	239	char *acct_name;
	240	struct nf_acct *cur;
	241	int ret = -ENOENT;
	242
	243	if (!tb[NFACCT_NAME]) {
	244	list_for_each_entry(cur, &nfnl_acct_list, head)
	245	nfnl_acct_try_del(cur);
	246
	247	return 0;
	248	}
	249	acct_name = nla_data(tb[NFACCT_NAME]);
	250
	251	list_for_each_entry(cur, &nfnl_acct_list, head) {
	252	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
	253	continue;
	254
	255	ret = nfnl_acct_try_del(cur);
	256	if (ret < 0)
	257	return ret;
	258
	259	break;
	260	}
	261	return ret;
	262	}
	263
	264	static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
	265	[NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
	266	[NFACCT_BYTES] = { .type = NLA_U64 },
	267	[NFACCT_PKTS] = { .type = NLA_U64 },
	268	};
	269
	270	static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
	271	[NFNL_MSG_ACCT_NEW] = { .call = nfnl_acct_new,
	272	.attr_count = NFACCT_MAX,
	273	.policy = nfnl_acct_policy },
	274	[NFNL_MSG_ACCT_GET] = { .call = nfnl_acct_get,
	275	.attr_count = NFACCT_MAX,
	276	.policy = nfnl_acct_policy },
277	[NFNL_MSG_ACCT_GET_CTRZERO] = { .call = nfnl_acct_get,
278	.attr_count = NFACCT_MAX,
279	.policy = nfnl_acct_policy },
280	[NFNL_MSG_ACCT_DEL] = { .call = nfnl_acct_del,
281	.attr_count = NFACCT_MAX,
282	.policy = nfnl_acct_policy },
283	};
284
285	static const struct nfnetlink_subsystem nfnl_acct_subsys = {
286	.name = "acct",
287	.subsys_id = NFNL_SUBSYS_ACCT,
288	.cb_count = NFNL_MSG_ACCT_MAX,
289	.cb = nfnl_acct_cb,
290	};
291
292	MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
293
294	struct nf_acct nfnl_acct_find_get(const char acct_name)
295	{
296	struct nf_acct cur, acct = NULL;
297
298	rcu_read_lock();
299	list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
300	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
301	continue;
302
303	if (!try_module_get(THIS_MODULE))
304	goto err;
305
306	if (!atomic_inc_not_zero(&cur->refcnt)) {
307	module_put(THIS_MODULE);
308	goto err;
309	}
310
311	acct = cur;
312	break;
313	}
314	err:
315	rcu_read_unlock();
316	return acct;
317	}
318	EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
319
320	void nfnl_acct_put(struct nf_acct *acct)
321	{
322	atomic_dec(&acct->refcnt);
323	module_put(THIS_MODULE);
324	}
325	EXPORT_SYMBOL_GPL(nfnl_acct_put);
326
327	void nfnl_acct_update(const struct sk_buff skb, struct nf_acct nfacct)
328	{
329	atomic64_inc(&nfacct->pkts);
330	atomic64_add(skb->len, &nfacct->bytes);
331	}
332	EXPORT_SYMBOL_GPL(nfnl_acct_update);
333
334	static int __init nfnl_acct_init(void)
335	{
336	int ret;
337
338	pr_info("nfnl_acct: registering with nfnetlink.\n");
339	ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
340	if (ret < 0) {
341	pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
342	goto err_out;
343	}
344	return 0;
345	err_out:
346	return ret;
347	}
348
349	static void __exit nfnl_acct_exit(void)
350	{
351	struct nf_acct cur, tmp;
352
353	pr_info("nfnl_acct: unregistering from nfnetlink.\n");
354	nfnetlink_subsys_unregister(&nfnl_acct_subsys);
355
356	list_for_each_entry_safe(cur, tmp, &nfnl_acct_list, head) {
357	list_del_rcu(&cur->head);
358	/* We are sure that our objects have no clients at this point,
359	* it's safe to release them all without checking refcnt. */
360	kfree_rcu(cur, rcu_head);
361	}
362	}
363
364	module_init(nfnl_acct_init);
365	module_exit(nfnl_acct_exit);