[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]);
	if (strlen(acct_name) == 0)
		return -EINVAL;

	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) {
			if (cur != last)
				continue;

			last = NULL;
		}
		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]);
deadcfc3 PNA	52	if (strlen(acct_name) == 0)
deadcfc3 PNA	53	return -EINVAL;
94139027 PNA	54
	55	list_for_each_entry(nfacct, &nfnl_acct_list, head) {
	56	if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
	57	continue;
	58
	59	if (nlh->nlmsg_flags & NLM_F_EXCL)
	60	return -EEXIST;
	61
	62	matching = nfacct;
	63	break;
	64	}
	65
	66	if (matching) {
	67	if (nlh->nlmsg_flags & NLM_F_REPLACE) {
	68	/* reset counters if you request a replacement. */
	69	atomic64_set(&matching->pkts, 0);
	70	atomic64_set(&matching->bytes, 0);
	71	return 0;
	72	}
	73	return -EBUSY;
	74	}
	75
	76	nfacct = kzalloc(sizeof(struct nf_acct), GFP_KERNEL);
	77	if (nfacct == NULL)
	78	return -ENOMEM;
	79
	80	strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
	81
	82	if (tb[NFACCT_BYTES]) {
	83	atomic64_set(&nfacct->bytes,
fe31d1a8	84	be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES])));
94139027 PNA	85	}
	86	if (tb[NFACCT_PKTS]) {
	87	atomic64_set(&nfacct->pkts,
fe31d1a8	88	be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS])));
94139027 PNA	89	}
	90	atomic_set(&nfacct->refcnt, 1);
	91	list_add_tail_rcu(&nfacct->head, &nfnl_acct_list);
	92	return 0;
	93	}
	94
	95	static int
15e47304	96	nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
94139027 PNA	97	int event, struct nf_acct *acct)
	98	{
	99	struct nlmsghdr *nlh;
	100	struct nfgenmsg *nfmsg;
15e47304	101	unsigned int flags = portid ? NLM_F_MULTI : 0;
94139027 PNA	102	u64 pkts, bytes;
	103
	104	event \|= NFNL_SUBSYS_ACCT << 8;
15e47304	105	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
94139027 PNA	106	if (nlh == NULL)
	107	goto nlmsg_failure;
	108
	109	nfmsg = nlmsg_data(nlh);
	110	nfmsg->nfgen_family = AF_UNSPEC;
	111	nfmsg->version = NFNETLINK_V0;
	112	nfmsg->res_id = 0;
	113
7c801189 DM	114	if (nla_put_string(skb, NFACCT_NAME, acct->name))
7c801189 DM	115	goto nla_put_failure;
94139027 PNA	116
	117	if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
	118	pkts = atomic64_xchg(&acct->pkts, 0);
	119	bytes = atomic64_xchg(&acct->bytes, 0);
	120	} else {
	121	pkts = atomic64_read(&acct->pkts);
	122	bytes = atomic64_read(&acct->bytes);
	123	}
7c801189 DM	124	if (nla_put_be64(skb, NFACCT_PKTS, cpu_to_be64(pkts)) \|\|
	125	nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes)) \|\|
	126	nla_put_be32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt))))
	127	goto nla_put_failure;
94139027 PNA	128
	129	nlmsg_end(skb, nlh);
	130	return skb->len;
	131
	132	nlmsg_failure:
	133	nla_put_failure:
	134	nlmsg_cancel(skb, nlh);
	135	return -1;
	136	}
	137
	138	static int
	139	nfnl_acct_dump(struct sk_buff skb, struct netlink_callback cb)
	140	{
	141	struct nf_acct cur, last;
	142
	143	if (cb->args[2])
	144	return 0;
	145
	146	last = (struct nf_acct *)cb->args[1];
	147	if (cb->args[1])
	148	cb->args[1] = 0;
	149
	150	rcu_read_lock();
	151	list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
991a6b73 PNA	152	if (last) {
	153	if (cur != last)
	154	continue;
94139027	155
991a6b73 PNA	156	last = NULL;
991a6b73 PNA	157	}
15e47304	158	if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid,
94139027 PNA	159	cb->nlh->nlmsg_seq,
	160	NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
	161	NFNL_MSG_ACCT_NEW, cur) < 0) {
	162	cb->args[1] = (unsigned long)cur;
	163	break;
	164	}
	165	}
	166	if (!cb->args[1])
	167	cb->args[2] = 1;
	168	rcu_read_unlock();
	169	return skb->len;
	170	}
	171
	172	static int
	173	nfnl_acct_get(struct sock nfnl, struct sk_buff skb,
	174	const struct nlmsghdr nlh, const struct nlattr const tb[])
	175	{
3ab0b245	176	int ret = -ENOENT;
94139027 PNA	177	struct nf_acct *cur;
	178	char *acct_name;
	179
	180	if (nlh->nlmsg_flags & NLM_F_DUMP) {
80d326fa PNA	181	struct netlink_dump_control c = {
	182	.dump = nfnl_acct_dump,
	183	};
	184	return netlink_dump_start(nfnl, skb, nlh, &c);
94139027 PNA	185	}
	186
	187	if (!tb[NFACCT_NAME])
	188	return -EINVAL;
	189	acct_name = nla_data(tb[NFACCT_NAME]);
	190
	191	list_for_each_entry(cur, &nfnl_acct_list, head) {
	192	struct sk_buff *skb2;
	193
	194	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
	195	continue;
	196
	197	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
3ab0b245 PNA	198	if (skb2 == NULL) {
3ab0b245 PNA	199	ret = -ENOMEM;
94139027	200	break;
3ab0b245	201	}
94139027	202
15e47304	203	ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid,
94139027 PNA	204	nlh->nlmsg_seq,
	205	NFNL_MSG_TYPE(nlh->nlmsg_type),
	206	NFNL_MSG_ACCT_NEW, cur);
3ab0b245	207	if (ret <= 0) {
94139027	208	kfree_skb(skb2);
3ab0b245 PNA	209	break;
3ab0b245 PNA	210	}
15e47304	211	ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
3ab0b245 PNA	212	MSG_DONTWAIT);
	213	if (ret > 0)
	214	ret = 0;
94139027	215
3ab0b245 PNA	216	/* this avoids a loop in nfnetlink. */
3ab0b245 PNA	217	return ret == -EAGAIN ? -ENOBUFS : ret;
94139027 PNA	218	}
	219	return ret;
	220	}
	221
	222	/* try to delete object, fail if it is still in use. */
	223	static int nfnl_acct_try_del(struct nf_acct *cur)
	224	{
	225	int ret = 0;
	226
	227	/* we want to avoid races with nfnl_acct_find_get. */
	228	if (atomic_dec_and_test(&cur->refcnt)) {
	229	/* We are protected by nfnl mutex. */
	230	list_del_rcu(&cur->head);
	231	kfree_rcu(cur, rcu_head);
	232	} else {
	233	/* still in use, restore reference counter. */
	234	atomic_inc(&cur->refcnt);
	235	ret = -EBUSY;
	236	}
	237	return ret;
	238	}
	239
	240	static int
	241	nfnl_acct_del(struct sock nfnl, struct sk_buff skb,
	242	const struct nlmsghdr nlh, const struct nlattr const tb[])
	243	{
	244	char *acct_name;
	245	struct nf_acct *cur;
	246	int ret = -ENOENT;
	247
	248	if (!tb[NFACCT_NAME]) {
	249	list_for_each_entry(cur, &nfnl_acct_list, head)
	250	nfnl_acct_try_del(cur);
	251
	252	return 0;
	253	}
	254	acct_name = nla_data(tb[NFACCT_NAME]);
	255
	256	list_for_each_entry(cur, &nfnl_acct_list, head) {
	257	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
	258	continue;
	259
	260	ret = nfnl_acct_try_del(cur);
	261	if (ret < 0)
	262	return ret;
	263
	264	break;
	265	}
	266	return ret;
	267	}
	268
	269	static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
	270	[NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
	271	[NFACCT_BYTES] = { .type = NLA_U64 },
	272	[NFACCT_PKTS] = { .type = NLA_U64 },
	273	};
	274
	275	static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
	276	[NFNL_MSG_ACCT_NEW] = { .call = nfnl_acct_new,
	277	.attr_count = NFACCT_MAX,
	278	.policy = nfnl_acct_policy },
	279	[NFNL_MSG_ACCT_GET] = { .call = nfnl_acct_get,
	280	.attr_count = NFACCT_MAX,
	281	.policy = nfnl_acct_policy },
282	[NFNL_MSG_ACCT_GET_CTRZERO] = { .call = nfnl_acct_get,
283	.attr_count = NFACCT_MAX,
284	.policy = nfnl_acct_policy },
285	[NFNL_MSG_ACCT_DEL] = { .call = nfnl_acct_del,
286	.attr_count = NFACCT_MAX,
287	.policy = nfnl_acct_policy },
288	};
289
290	static const struct nfnetlink_subsystem nfnl_acct_subsys = {
291	.name = "acct",
292	.subsys_id = NFNL_SUBSYS_ACCT,
293	.cb_count = NFNL_MSG_ACCT_MAX,
294	.cb = nfnl_acct_cb,
295	};
296
297	MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
298
299	struct nf_acct nfnl_acct_find_get(const char acct_name)
300	{
301	struct nf_acct cur, acct = NULL;
302
303	rcu_read_lock();
304	list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
305	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
306	continue;
307
308	if (!try_module_get(THIS_MODULE))
309	goto err;
310
311	if (!atomic_inc_not_zero(&cur->refcnt)) {
312	module_put(THIS_MODULE);
313	goto err;
314	}
315
316	acct = cur;
317	break;
318	}
319	err:
320	rcu_read_unlock();
321	return acct;
322	}
323	EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
324
325	void nfnl_acct_put(struct nf_acct *acct)
326	{
327	atomic_dec(&acct->refcnt);
328	module_put(THIS_MODULE);
329	}
330	EXPORT_SYMBOL_GPL(nfnl_acct_put);
331
332	void nfnl_acct_update(const struct sk_buff skb, struct nf_acct nfacct)
333	{
334	atomic64_inc(&nfacct->pkts);
335	atomic64_add(skb->len, &nfacct->bytes);
336	}
337	EXPORT_SYMBOL_GPL(nfnl_acct_update);
338
339	static int __init nfnl_acct_init(void)
340	{
341	int ret;
342
343	pr_info("nfnl_acct: registering with nfnetlink.\n");
344	ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
345	if (ret < 0) {
346	pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
347	goto err_out;
348	}
349	return 0;
350	err_out:
351	return ret;
352	}
353
354	static void __exit nfnl_acct_exit(void)
355	{
356	struct nf_acct cur, tmp;
357
358	pr_info("nfnl_acct: unregistering from nfnetlink.\n");
359	nfnetlink_subsys_unregister(&nfnl_acct_subsys);
360
361	list_for_each_entry_safe(cur, tmp, &nfnl_acct_list, head) {
362	list_del_rcu(&cur->head);
363	/* We are sure that our objects have no clients at this point,
364	* it's safe to release them all without checking refcnt. */
365	kfree_rcu(cur, rcu_head);
366	}
367	}
368
369	module_init(nfnl_acct_init);
370	module_exit(nfnl_acct_exit);