[deliverable/linux.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;
	unsigned long		flags;
	struct list_head	head;
	atomic_t		refcnt;
	char			name[NFACCT_NAME_MAX];
	struct rcu_head		rcu_head;
	char			data[0];
};

#define NFACCT_F_QUOTA (NFACCT_F_QUOTA_PKTS | NFACCT_F_QUOTA_BYTES)

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;
	unsigned int size = 0;
	u32 flags = 0;

	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);
			smp_mb__before_atomic();
			/* reset overquota flag if quota is enabled. */
			if ((matching->flags & NFACCT_F_QUOTA))
				clear_bit(NFACCT_F_OVERQUOTA, &matching->flags);
			return 0;
		}
		return -EBUSY;
	}

	if (tb[NFACCT_FLAGS]) {
		flags = ntohl(nla_get_be32(tb[NFACCT_FLAGS]));
		if (flags & ~NFACCT_F_QUOTA)
			return -EOPNOTSUPP;
		if ((flags & NFACCT_F_QUOTA) == NFACCT_F_QUOTA)
			return -EINVAL;
		if (flags & NFACCT_F_OVERQUOTA)
			return -EINVAL;

		size += sizeof(u64);
	}

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

	if (flags & NFACCT_F_QUOTA) {
		u64 *quota = (u64 *)nfacct->data;

		*quota = be64_to_cpu(nla_get_be64(tb[NFACCT_QUOTA]));
		nfacct->flags = flags;
	}

	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);
		smp_mb__before_atomic();
		if (acct->flags & NFACCT_F_QUOTA)
			clear_bit(NFACCT_F_OVERQUOTA, &acct->flags);
	} 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;
	if (acct->flags & NFACCT_F_QUOTA) {
		u64 *quota = (u64 *)acct->data;

		if (nla_put_be32(skb, NFACCT_FLAGS, htonl(acct->flags)) ||
		    nla_put_be64(skb, NFACCT_QUOTA, cpu_to_be64(*quota)))
			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 },
	[NFACCT_FLAGS] = { .type = NLA_U32 },
	[NFACCT_QUOTA] = { .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 void nfnl_overquota_report(struct nf_acct *nfacct)
{
	int ret;
	struct sk_buff *skb;

	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
	if (skb == NULL)
		return;

	ret = nfnl_acct_fill_info(skb, 0, 0, NFNL_MSG_ACCT_OVERQUOTA, 0,
				  nfacct);
	if (ret <= 0) {
		kfree_skb(skb);
		return;
	}
	netlink_broadcast(init_net.nfnl, skb, 0, NFNLGRP_ACCT_QUOTA,
			  GFP_ATOMIC);
}

int nfnl_acct_overquota(const struct sk_buff *skb, struct nf_acct *nfacct)
{
	u64 now;
	u64 *quota;
	int ret = NFACCT_UNDERQUOTA;

	/* no place here if we don't have a quota */
	if (!(nfacct->flags & NFACCT_F_QUOTA))
		return NFACCT_NO_QUOTA;

	quota = (u64 *)nfacct->data;
	now = (nfacct->flags & NFACCT_F_QUOTA_PKTS) ?
	       atomic64_read(&nfacct->pkts) : atomic64_read(&nfacct->bytes);

	ret = now > *quota;

	if (now >= *quota &&
	    !test_and_set_bit(NFACCT_F_OVERQUOTA, &nfacct->flags)) {
		nfnl_overquota_report(nfacct);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(nfnl_acct_overquota);

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;
683399ed	35	unsigned long flags;
94139027 PNA	36	struct list_head head;
	37	atomic_t refcnt;
	38	char name[NFACCT_NAME_MAX];
	39	struct rcu_head rcu_head;
683399ed	40	char data[0];
94139027 PNA	41	};
94139027 PNA	42
683399ed MP	43	#define NFACCT_F_QUOTA (NFACCT_F_QUOTA_PKTS \| NFACCT_F_QUOTA_BYTES)
683399ed MP	44
94139027 PNA	45	static int
	46	nfnl_acct_new(struct sock nfnl, struct sk_buff skb,
	47	const struct nlmsghdr nlh, const struct nlattr const tb[])
	48	{
	49	struct nf_acct nfacct, matching = NULL;
	50	char *acct_name;
683399ed MP	51	unsigned int size = 0;
683399ed MP	52	u32 flags = 0;
94139027 PNA	53
	54	if (!tb[NFACCT_NAME])
	55	return -EINVAL;
	56
	57	acct_name = nla_data(tb[NFACCT_NAME]);
deadcfc3 PNA	58	if (strlen(acct_name) == 0)
deadcfc3 PNA	59	return -EINVAL;
94139027 PNA	60
	61	list_for_each_entry(nfacct, &nfnl_acct_list, head) {
	62	if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
	63	continue;
	64
	65	if (nlh->nlmsg_flags & NLM_F_EXCL)
	66	return -EEXIST;
	67
	68	matching = nfacct;
	69	break;
	70	}
	71
	72	if (matching) {
	73	if (nlh->nlmsg_flags & NLM_F_REPLACE) {
	74	/* reset counters if you request a replacement. */
	75	atomic64_set(&matching->pkts, 0);
	76	atomic64_set(&matching->bytes, 0);
f9da455b	77	smp_mb__before_atomic();
683399ed MP	78	/* reset overquota flag if quota is enabled. */
	79	if ((matching->flags & NFACCT_F_QUOTA))
	80	clear_bit(NFACCT_F_OVERQUOTA, &matching->flags);
94139027 PNA	81	return 0;
	82	}
	83	return -EBUSY;
	84	}
	85
683399ed MP	86	if (tb[NFACCT_FLAGS]) {
	87	flags = ntohl(nla_get_be32(tb[NFACCT_FLAGS]));
	88	if (flags & ~NFACCT_F_QUOTA)
	89	return -EOPNOTSUPP;
	90	if ((flags & NFACCT_F_QUOTA) == NFACCT_F_QUOTA)
	91	return -EINVAL;
	92	if (flags & NFACCT_F_OVERQUOTA)
	93	return -EINVAL;
	94
	95	size += sizeof(u64);
	96	}
	97
	98	nfacct = kzalloc(sizeof(struct nf_acct) + size, GFP_KERNEL);
94139027 PNA	99	if (nfacct == NULL)
	100	return -ENOMEM;
	101
683399ed MP	102	if (flags & NFACCT_F_QUOTA) {
	103	u64 quota = (u64 )nfacct->data;
	104
	105	*quota = be64_to_cpu(nla_get_be64(tb[NFACCT_QUOTA]));
	106	nfacct->flags = flags;
	107	}
	108
94139027 PNA	109	strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
	110
	111	if (tb[NFACCT_BYTES]) {
	112	atomic64_set(&nfacct->bytes,
fe31d1a8	113	be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES])));
94139027 PNA	114	}
	115	if (tb[NFACCT_PKTS]) {
	116	atomic64_set(&nfacct->pkts,
fe31d1a8	117	be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS])));
94139027 PNA	118	}
	119	atomic_set(&nfacct->refcnt, 1);
	120	list_add_tail_rcu(&nfacct->head, &nfnl_acct_list);
	121	return 0;
	122	}
	123
	124	static int
15e47304	125	nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
94139027 PNA	126	int event, struct nf_acct *acct)
	127	{
	128	struct nlmsghdr *nlh;
	129	struct nfgenmsg *nfmsg;
15e47304	130	unsigned int flags = portid ? NLM_F_MULTI : 0;
94139027 PNA	131	u64 pkts, bytes;
	132
	133	event \|= NFNL_SUBSYS_ACCT << 8;
15e47304	134	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
94139027 PNA	135	if (nlh == NULL)
	136	goto nlmsg_failure;
	137
	138	nfmsg = nlmsg_data(nlh);
	139	nfmsg->nfgen_family = AF_UNSPEC;
	140	nfmsg->version = NFNETLINK_V0;
	141	nfmsg->res_id = 0;
	142
7c801189 DM	143	if (nla_put_string(skb, NFACCT_NAME, acct->name))
7c801189 DM	144	goto nla_put_failure;
94139027 PNA	145
	146	if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
	147	pkts = atomic64_xchg(&acct->pkts, 0);
	148	bytes = atomic64_xchg(&acct->bytes, 0);
f9da455b	149	smp_mb__before_atomic();
683399ed MP	150	if (acct->flags & NFACCT_F_QUOTA)
683399ed MP	151	clear_bit(NFACCT_F_OVERQUOTA, &acct->flags);
94139027 PNA	152	} else {
	153	pkts = atomic64_read(&acct->pkts);
	154	bytes = atomic64_read(&acct->bytes);
	155	}
7c801189 DM	156	if (nla_put_be64(skb, NFACCT_PKTS, cpu_to_be64(pkts)) \|\|
	157	nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes)) \|\|
	158	nla_put_be32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt))))
	159	goto nla_put_failure;
683399ed MP	160	if (acct->flags & NFACCT_F_QUOTA) {
683399ed MP	161	u64 quota = (u64 )acct->data;
94139027	162
683399ed MP	163	if (nla_put_be32(skb, NFACCT_FLAGS, htonl(acct->flags)) \|\|
	164	nla_put_be64(skb, NFACCT_QUOTA, cpu_to_be64(*quota)))
	165	goto nla_put_failure;
	166	}
94139027 PNA	167	nlmsg_end(skb, nlh);
	168	return skb->len;
	169
	170	nlmsg_failure:
	171	nla_put_failure:
	172	nlmsg_cancel(skb, nlh);
	173	return -1;
	174	}
	175
	176	static int
	177	nfnl_acct_dump(struct sk_buff skb, struct netlink_callback cb)
	178	{
	179	struct nf_acct cur, last;
	180
	181	if (cb->args[2])
	182	return 0;
	183
	184	last = (struct nf_acct *)cb->args[1];
	185	if (cb->args[1])
	186	cb->args[1] = 0;
	187
	188	rcu_read_lock();
	189	list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
991a6b73 PNA	190	if (last) {
	191	if (cur != last)
	192	continue;
94139027	193
991a6b73 PNA	194	last = NULL;
991a6b73 PNA	195	}
15e47304	196	if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid,
94139027 PNA	197	cb->nlh->nlmsg_seq,
	198	NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
	199	NFNL_MSG_ACCT_NEW, cur) < 0) {
	200	cb->args[1] = (unsigned long)cur;
	201	break;
	202	}
	203	}
	204	if (!cb->args[1])
	205	cb->args[2] = 1;
	206	rcu_read_unlock();
	207	return skb->len;
	208	}
	209
	210	static int
	211	nfnl_acct_get(struct sock nfnl, struct sk_buff skb,
	212	const struct nlmsghdr nlh, const struct nlattr const tb[])
	213	{
3ab0b245	214	int ret = -ENOENT;
94139027 PNA	215	struct nf_acct *cur;
	216	char *acct_name;
	217
	218	if (nlh->nlmsg_flags & NLM_F_DUMP) {
80d326fa PNA	219	struct netlink_dump_control c = {
	220	.dump = nfnl_acct_dump,
	221	};
	222	return netlink_dump_start(nfnl, skb, nlh, &c);
94139027 PNA	223	}
	224
	225	if (!tb[NFACCT_NAME])
	226	return -EINVAL;
	227	acct_name = nla_data(tb[NFACCT_NAME]);
	228
	229	list_for_each_entry(cur, &nfnl_acct_list, head) {
	230	struct sk_buff *skb2;
	231
	232	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
	233	continue;
	234
	235	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
3ab0b245 PNA	236	if (skb2 == NULL) {
3ab0b245 PNA	237	ret = -ENOMEM;
94139027	238	break;
3ab0b245	239	}
94139027	240
15e47304	241	ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid,
94139027 PNA	242	nlh->nlmsg_seq,
	243	NFNL_MSG_TYPE(nlh->nlmsg_type),
	244	NFNL_MSG_ACCT_NEW, cur);
3ab0b245	245	if (ret <= 0) {
94139027	246	kfree_skb(skb2);
3ab0b245 PNA	247	break;
3ab0b245 PNA	248	}
15e47304	249	ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
3ab0b245 PNA	250	MSG_DONTWAIT);
	251	if (ret > 0)
	252	ret = 0;
94139027	253
3ab0b245 PNA	254	/* this avoids a loop in nfnetlink. */
3ab0b245 PNA	255	return ret == -EAGAIN ? -ENOBUFS : ret;
94139027 PNA	256	}
	257	return ret;
	258	}
	259
	260	/* try to delete object, fail if it is still in use. */
	261	static int nfnl_acct_try_del(struct nf_acct *cur)
	262	{
	263	int ret = 0;
	264
	265	/* we want to avoid races with nfnl_acct_find_get. */
	266	if (atomic_dec_and_test(&cur->refcnt)) {
	267	/* We are protected by nfnl mutex. */
	268	list_del_rcu(&cur->head);
	269	kfree_rcu(cur, rcu_head);
	270	} else {
	271	/* still in use, restore reference counter. */
	272	atomic_inc(&cur->refcnt);
	273	ret = -EBUSY;
	274	}
	275	return ret;
	276	}
	277
	278	static int
	279	nfnl_acct_del(struct sock nfnl, struct sk_buff skb,
	280	const struct nlmsghdr nlh, const struct nlattr const tb[])
	281	{
	282	char *acct_name;
	283	struct nf_acct *cur;
	284	int ret = -ENOENT;
	285
	286	if (!tb[NFACCT_NAME]) {
	287	list_for_each_entry(cur, &nfnl_acct_list, head)
	288	nfnl_acct_try_del(cur);
	289
	290	return 0;
	291	}
	292	acct_name = nla_data(tb[NFACCT_NAME]);
	293
	294	list_for_each_entry(cur, &nfnl_acct_list, head) {
	295	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
	296	continue;
	297
	298	ret = nfnl_acct_try_del(cur);
	299	if (ret < 0)
	300	return ret;
	301
	302	break;
	303	}
	304	return ret;
	305	}
	306
	307	static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
	308	[NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
	309	[NFACCT_BYTES] = { .type = NLA_U64 },
	310	[NFACCT_PKTS] = { .type = NLA_U64 },
683399ed MP	311	[NFACCT_FLAGS] = { .type = NLA_U32 },
683399ed MP	312	[NFACCT_QUOTA] = { .type = NLA_U64 },
94139027 PNA	313	};
	314
	315	static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
	316	[NFNL_MSG_ACCT_NEW] = { .call = nfnl_acct_new,
	317	.attr_count = NFACCT_MAX,
	318	.policy = nfnl_acct_policy },
	319	[NFNL_MSG_ACCT_GET] = { .call = nfnl_acct_get,
	320	.attr_count = NFACCT_MAX,
	321	.policy = nfnl_acct_policy },
	322	[NFNL_MSG_ACCT_GET_CTRZERO] = { .call = nfnl_acct_get,
	323	.attr_count = NFACCT_MAX,
	324	.policy = nfnl_acct_policy },
	325	[NFNL_MSG_ACCT_DEL] = { .call = nfnl_acct_del,
	326	.attr_count = NFACCT_MAX,
	327	.policy = nfnl_acct_policy },
	328	};
	329
	330	static const struct nfnetlink_subsystem nfnl_acct_subsys = {
	331	.name = "acct",
	332	.subsys_id = NFNL_SUBSYS_ACCT,
	333	.cb_count = NFNL_MSG_ACCT_MAX,
	334	.cb = nfnl_acct_cb,
	335	};
	336
	337	MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
	338
	339	struct nf_acct nfnl_acct_find_get(const char acct_name)
	340	{
	341	struct nf_acct cur, acct = NULL;
	342
	343	rcu_read_lock();
	344	list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
	345	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
	346	continue;
	347
	348	if (!try_module_get(THIS_MODULE))
	349	goto err;
	350
	351	if (!atomic_inc_not_zero(&cur->refcnt)) {
	352	module_put(THIS_MODULE);
	353	goto err;
	354	}
	355
	356	acct = cur;
	357	break;
	358	}
	359	err:
	360	rcu_read_unlock();
	361	return acct;
	362	}
	363	EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
	364
	365	void nfnl_acct_put(struct nf_acct *acct)
	366	{
	367	atomic_dec(&acct->refcnt);
	368	module_put(THIS_MODULE);
	369	}
	370	EXPORT_SYMBOL_GPL(nfnl_acct_put);
	371
	372	void nfnl_acct_update(const struct sk_buff skb, struct nf_acct nfacct)
	373	{
	374	atomic64_inc(&nfacct->pkts);
	375	atomic64_add(skb->len, &nfacct->bytes);
	376	}
377	EXPORT_SYMBOL_GPL(nfnl_acct_update);
378
683399ed MP	379	static void nfnl_overquota_report(struct nf_acct *nfacct)
	380	{
	381	int ret;
	382	struct sk_buff *skb;
	383
	384	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
	385	if (skb == NULL)
	386	return;
	387
	388	ret = nfnl_acct_fill_info(skb, 0, 0, NFNL_MSG_ACCT_OVERQUOTA, 0,
	389	nfacct);
	390	if (ret <= 0) {
	391	kfree_skb(skb);
	392	return;
	393	}
	394	netlink_broadcast(init_net.nfnl, skb, 0, NFNLGRP_ACCT_QUOTA,
	395	GFP_ATOMIC);
	396	}
	397
	398	int nfnl_acct_overquota(const struct sk_buff skb, struct nf_acct nfacct)
	399	{
	400	u64 now;
	401	u64 *quota;
	402	int ret = NFACCT_UNDERQUOTA;
	403
	404	/* no place here if we don't have a quota */
	405	if (!(nfacct->flags & NFACCT_F_QUOTA))
	406	return NFACCT_NO_QUOTA;
	407
	408	quota = (u64 *)nfacct->data;
	409	now = (nfacct->flags & NFACCT_F_QUOTA_PKTS) ?
	410	atomic64_read(&nfacct->pkts) : atomic64_read(&nfacct->bytes);
	411
	412	ret = now > *quota;
	413
	414	if (now >= *quota &&
	415	!test_and_set_bit(NFACCT_F_OVERQUOTA, &nfacct->flags)) {
	416	nfnl_overquota_report(nfacct);
	417	}
	418
	419	return ret;
	420	}
	421	EXPORT_SYMBOL_GPL(nfnl_acct_overquota);
	422
94139027 PNA	423	static int __init nfnl_acct_init(void)
	424	{
	425	int ret;
	426
	427	pr_info("nfnl_acct: registering with nfnetlink.\n");
	428	ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
	429	if (ret < 0) {
	430	pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
	431	goto err_out;
	432	}
	433	return 0;
	434	err_out:
	435	return ret;
	436	}
	437
	438	static void __exit nfnl_acct_exit(void)
	439	{
	440	struct nf_acct cur, tmp;
	441
	442	pr_info("nfnl_acct: unregistering from nfnetlink.\n");
	443	nfnetlink_subsys_unregister(&nfnl_acct_subsys);
	444
	445	list_for_each_entry_safe(cur, tmp, &nfnl_acct_list, head) {
	446	list_del_rcu(&cur->head);
	447	/* We are sure that our objects have no clients at this point,
	448	* it's safe to release them all without checking refcnt. */
	449	kfree_rcu(cur, rcu_head);
	450	}
	451	}
	452
	453	module_init(nfnl_acct_init);
	454	module_exit(nfnl_acct_exit);