[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)
#define NFACCT_OVERQUOTA_BIT	2	/* NFACCT_F_OVERQUOTA */

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_OVERQUOTA_BIT,
					  &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;
	u32 old_flags;

	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;

	old_flags = acct->flags;
	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_OVERQUOTA_BIT, &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(old_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_OVERQUOTA_BIT, &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	43	#define NFACCT_F_QUOTA (NFACCT_F_QUOTA_PKTS \| NFACCT_F_QUOTA_BYTES)
b6d04688	44	#define NFACCT_OVERQUOTA_BIT 2 /* NFACCT_F_OVERQUOTA */
683399ed	45
94139027 PNA	46	static int
	47	nfnl_acct_new(struct sock nfnl, struct sk_buff skb,
	48	const struct nlmsghdr nlh, const struct nlattr const tb[])
	49	{
	50	struct nf_acct nfacct, matching = NULL;
	51	char *acct_name;
683399ed MP	52	unsigned int size = 0;
683399ed MP	53	u32 flags = 0;
94139027 PNA	54
	55	if (!tb[NFACCT_NAME])
	56	return -EINVAL;
	57
	58	acct_name = nla_data(tb[NFACCT_NAME]);
deadcfc3 PNA	59	if (strlen(acct_name) == 0)
deadcfc3 PNA	60	return -EINVAL;
94139027 PNA	61
	62	list_for_each_entry(nfacct, &nfnl_acct_list, head) {
	63	if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
	64	continue;
	65
	66	if (nlh->nlmsg_flags & NLM_F_EXCL)
	67	return -EEXIST;
	68
	69	matching = nfacct;
	70	break;
	71	}
	72
	73	if (matching) {
	74	if (nlh->nlmsg_flags & NLM_F_REPLACE) {
	75	/* reset counters if you request a replacement. */
	76	atomic64_set(&matching->pkts, 0);
	77	atomic64_set(&matching->bytes, 0);
f9da455b	78	smp_mb__before_atomic();
683399ed MP	79	/* reset overquota flag if quota is enabled. */
683399ed MP	80	if ((matching->flags & NFACCT_F_QUOTA))
b6d04688 AP	81	clear_bit(NFACCT_OVERQUOTA_BIT,
b6d04688 AP	82	&matching->flags);
94139027 PNA	83	return 0;
	84	}
	85	return -EBUSY;
	86	}
	87
683399ed MP	88	if (tb[NFACCT_FLAGS]) {
	89	flags = ntohl(nla_get_be32(tb[NFACCT_FLAGS]));
	90	if (flags & ~NFACCT_F_QUOTA)
	91	return -EOPNOTSUPP;
	92	if ((flags & NFACCT_F_QUOTA) == NFACCT_F_QUOTA)
	93	return -EINVAL;
	94	if (flags & NFACCT_F_OVERQUOTA)
	95	return -EINVAL;
	96
	97	size += sizeof(u64);
	98	}
	99
	100	nfacct = kzalloc(sizeof(struct nf_acct) + size, GFP_KERNEL);
94139027 PNA	101	if (nfacct == NULL)
	102	return -ENOMEM;
	103
683399ed MP	104	if (flags & NFACCT_F_QUOTA) {
	105	u64 quota = (u64 )nfacct->data;
	106
	107	*quota = be64_to_cpu(nla_get_be64(tb[NFACCT_QUOTA]));
	108	nfacct->flags = flags;
	109	}
	110
94139027 PNA	111	strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
	112
	113	if (tb[NFACCT_BYTES]) {
	114	atomic64_set(&nfacct->bytes,
fe31d1a8	115	be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES])));
94139027 PNA	116	}
	117	if (tb[NFACCT_PKTS]) {
	118	atomic64_set(&nfacct->pkts,
fe31d1a8	119	be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS])));
94139027 PNA	120	}
	121	atomic_set(&nfacct->refcnt, 1);
	122	list_add_tail_rcu(&nfacct->head, &nfnl_acct_list);
	123	return 0;
	124	}
	125
	126	static int
15e47304	127	nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
94139027 PNA	128	int event, struct nf_acct *acct)
	129	{
	130	struct nlmsghdr *nlh;
	131	struct nfgenmsg *nfmsg;
15e47304	132	unsigned int flags = portid ? NLM_F_MULTI : 0;
94139027	133	u64 pkts, bytes;
d24675cb	134	u32 old_flags;
94139027 PNA	135
94139027 PNA	136	event \|= NFNL_SUBSYS_ACCT << 8;
15e47304	137	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
94139027 PNA	138	if (nlh == NULL)
	139	goto nlmsg_failure;
	140
	141	nfmsg = nlmsg_data(nlh);
	142	nfmsg->nfgen_family = AF_UNSPEC;
	143	nfmsg->version = NFNETLINK_V0;
	144	nfmsg->res_id = 0;
	145
7c801189 DM	146	if (nla_put_string(skb, NFACCT_NAME, acct->name))
7c801189 DM	147	goto nla_put_failure;
94139027	148
d24675cb	149	old_flags = acct->flags;
94139027 PNA	150	if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
	151	pkts = atomic64_xchg(&acct->pkts, 0);
	152	bytes = atomic64_xchg(&acct->bytes, 0);
f9da455b	153	smp_mb__before_atomic();
683399ed	154	if (acct->flags & NFACCT_F_QUOTA)
b6d04688	155	clear_bit(NFACCT_OVERQUOTA_BIT, &acct->flags);
94139027 PNA	156	} else {
	157	pkts = atomic64_read(&acct->pkts);
	158	bytes = atomic64_read(&acct->bytes);
	159	}
7c801189 DM	160	if (nla_put_be64(skb, NFACCT_PKTS, cpu_to_be64(pkts)) \|\|
	161	nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes)) \|\|
	162	nla_put_be32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt))))
	163	goto nla_put_failure;
683399ed MP	164	if (acct->flags & NFACCT_F_QUOTA) {
683399ed MP	165	u64 quota = (u64 )acct->data;
94139027	166
d24675cb	167	if (nla_put_be32(skb, NFACCT_FLAGS, htonl(old_flags)) \|\|
683399ed MP	168	nla_put_be64(skb, NFACCT_QUOTA, cpu_to_be64(*quota)))
	169	goto nla_put_failure;
	170	}
94139027 PNA	171	nlmsg_end(skb, nlh);
	172	return skb->len;
	173
	174	nlmsg_failure:
	175	nla_put_failure:
	176	nlmsg_cancel(skb, nlh);
	177	return -1;
	178	}
	179
	180	static int
	181	nfnl_acct_dump(struct sk_buff skb, struct netlink_callback cb)
	182	{
	183	struct nf_acct cur, last;
	184
	185	if (cb->args[2])
	186	return 0;
	187
	188	last = (struct nf_acct *)cb->args[1];
	189	if (cb->args[1])
	190	cb->args[1] = 0;
	191
	192	rcu_read_lock();
	193	list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
991a6b73 PNA	194	if (last) {
	195	if (cur != last)
	196	continue;
94139027	197
991a6b73 PNA	198	last = NULL;
991a6b73 PNA	199	}
15e47304	200	if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid,
94139027 PNA	201	cb->nlh->nlmsg_seq,
	202	NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
	203	NFNL_MSG_ACCT_NEW, cur) < 0) {
	204	cb->args[1] = (unsigned long)cur;
	205	break;
	206	}
	207	}
	208	if (!cb->args[1])
	209	cb->args[2] = 1;
	210	rcu_read_unlock();
	211	return skb->len;
	212	}
	213
	214	static int
	215	nfnl_acct_get(struct sock nfnl, struct sk_buff skb,
	216	const struct nlmsghdr nlh, const struct nlattr const tb[])
	217	{
3ab0b245	218	int ret = -ENOENT;
94139027 PNA	219	struct nf_acct *cur;
	220	char *acct_name;
	221
	222	if (nlh->nlmsg_flags & NLM_F_DUMP) {
80d326fa PNA	223	struct netlink_dump_control c = {
	224	.dump = nfnl_acct_dump,
	225	};
	226	return netlink_dump_start(nfnl, skb, nlh, &c);
94139027 PNA	227	}
	228
	229	if (!tb[NFACCT_NAME])
	230	return -EINVAL;
	231	acct_name = nla_data(tb[NFACCT_NAME]);
	232
	233	list_for_each_entry(cur, &nfnl_acct_list, head) {
	234	struct sk_buff *skb2;
	235
	236	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
	237	continue;
	238
	239	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
3ab0b245 PNA	240	if (skb2 == NULL) {
3ab0b245 PNA	241	ret = -ENOMEM;
94139027	242	break;
3ab0b245	243	}
94139027	244
15e47304	245	ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid,
94139027 PNA	246	nlh->nlmsg_seq,
	247	NFNL_MSG_TYPE(nlh->nlmsg_type),
	248	NFNL_MSG_ACCT_NEW, cur);
3ab0b245	249	if (ret <= 0) {
94139027	250	kfree_skb(skb2);
3ab0b245 PNA	251	break;
3ab0b245 PNA	252	}
15e47304	253	ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
3ab0b245 PNA	254	MSG_DONTWAIT);
	255	if (ret > 0)
	256	ret = 0;
94139027	257
3ab0b245 PNA	258	/* this avoids a loop in nfnetlink. */
3ab0b245 PNA	259	return ret == -EAGAIN ? -ENOBUFS : ret;
94139027 PNA	260	}
	261	return ret;
	262	}
	263
	264	/* try to delete object, fail if it is still in use. */
	265	static int nfnl_acct_try_del(struct nf_acct *cur)
	266	{
	267	int ret = 0;
	268
	269	/* we want to avoid races with nfnl_acct_find_get. */
	270	if (atomic_dec_and_test(&cur->refcnt)) {
	271	/* We are protected by nfnl mutex. */
	272	list_del_rcu(&cur->head);
	273	kfree_rcu(cur, rcu_head);
	274	} else {
	275	/* still in use, restore reference counter. */
	276	atomic_inc(&cur->refcnt);
	277	ret = -EBUSY;
	278	}
	279	return ret;
	280	}
	281
	282	static int
	283	nfnl_acct_del(struct sock nfnl, struct sk_buff skb,
	284	const struct nlmsghdr nlh, const struct nlattr const tb[])
	285	{
	286	char *acct_name;
	287	struct nf_acct *cur;
	288	int ret = -ENOENT;
	289
	290	if (!tb[NFACCT_NAME]) {
	291	list_for_each_entry(cur, &nfnl_acct_list, head)
	292	nfnl_acct_try_del(cur);
	293
	294	return 0;
	295	}
	296	acct_name = nla_data(tb[NFACCT_NAME]);
	297
	298	list_for_each_entry(cur, &nfnl_acct_list, head) {
	299	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
	300	continue;
	301
	302	ret = nfnl_acct_try_del(cur);
	303	if (ret < 0)
	304	return ret;
	305
	306	break;
	307	}
	308	return ret;
	309	}
	310
	311	static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
	312	[NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
	313	[NFACCT_BYTES] = { .type = NLA_U64 },
	314	[NFACCT_PKTS] = { .type = NLA_U64 },
683399ed MP	315	[NFACCT_FLAGS] = { .type = NLA_U32 },
683399ed MP	316	[NFACCT_QUOTA] = { .type = NLA_U64 },
94139027 PNA	317	};
	318
	319	static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
	320	[NFNL_MSG_ACCT_NEW] = { .call = nfnl_acct_new,
	321	.attr_count = NFACCT_MAX,
	322	.policy = nfnl_acct_policy },
	323	[NFNL_MSG_ACCT_GET] = { .call = nfnl_acct_get,
	324	.attr_count = NFACCT_MAX,
	325	.policy = nfnl_acct_policy },
	326	[NFNL_MSG_ACCT_GET_CTRZERO] = { .call = nfnl_acct_get,
	327	.attr_count = NFACCT_MAX,
	328	.policy = nfnl_acct_policy },
	329	[NFNL_MSG_ACCT_DEL] = { .call = nfnl_acct_del,
	330	.attr_count = NFACCT_MAX,
	331	.policy = nfnl_acct_policy },
	332	};
	333
	334	static const struct nfnetlink_subsystem nfnl_acct_subsys = {
	335	.name = "acct",
	336	.subsys_id = NFNL_SUBSYS_ACCT,
	337	.cb_count = NFNL_MSG_ACCT_MAX,
	338	.cb = nfnl_acct_cb,
	339	};
	340
	341	MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
	342
	343	struct nf_acct nfnl_acct_find_get(const char acct_name)
	344	{
	345	struct nf_acct cur, acct = NULL;
	346
	347	rcu_read_lock();
	348	list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
	349	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
	350	continue;
	351
	352	if (!try_module_get(THIS_MODULE))
	353	goto err;
	354
	355	if (!atomic_inc_not_zero(&cur->refcnt)) {
	356	module_put(THIS_MODULE);
	357	goto err;
	358	}
	359
	360	acct = cur;
	361	break;
	362	}
	363	err:
	364	rcu_read_unlock();
	365	return acct;
	366	}
	367	EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
	368
	369	void nfnl_acct_put(struct nf_acct *acct)
	370	{
	371	atomic_dec(&acct->refcnt);
	372	module_put(THIS_MODULE);
	373	}
	374	EXPORT_SYMBOL_GPL(nfnl_acct_put);
	375
	376	void nfnl_acct_update(const struct sk_buff skb, struct nf_acct nfacct)
	377	{
	378	atomic64_inc(&nfacct->pkts);
	379	atomic64_add(skb->len, &nfacct->bytes);
	380	}
381	EXPORT_SYMBOL_GPL(nfnl_acct_update);
382
683399ed MP	383	static void nfnl_overquota_report(struct nf_acct *nfacct)
	384	{
	385	int ret;
	386	struct sk_buff *skb;
	387
	388	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
	389	if (skb == NULL)
	390	return;
	391
	392	ret = nfnl_acct_fill_info(skb, 0, 0, NFNL_MSG_ACCT_OVERQUOTA, 0,
	393	nfacct);
	394	if (ret <= 0) {
	395	kfree_skb(skb);
	396	return;
	397	}
	398	netlink_broadcast(init_net.nfnl, skb, 0, NFNLGRP_ACCT_QUOTA,
	399	GFP_ATOMIC);
	400	}
	401
	402	int nfnl_acct_overquota(const struct sk_buff skb, struct nf_acct nfacct)
	403	{
	404	u64 now;
	405	u64 *quota;
	406	int ret = NFACCT_UNDERQUOTA;
	407
	408	/* no place here if we don't have a quota */
	409	if (!(nfacct->flags & NFACCT_F_QUOTA))
	410	return NFACCT_NO_QUOTA;
	411
	412	quota = (u64 *)nfacct->data;
	413	now = (nfacct->flags & NFACCT_F_QUOTA_PKTS) ?
	414	atomic64_read(&nfacct->pkts) : atomic64_read(&nfacct->bytes);
	415
	416	ret = now > *quota;
	417
	418	if (now >= *quota &&
b6d04688	419	!test_and_set_bit(NFACCT_OVERQUOTA_BIT, &nfacct->flags)) {
683399ed MP	420	nfnl_overquota_report(nfacct);
	421	}
	422
	423	return ret;
	424	}
	425	EXPORT_SYMBOL_GPL(nfnl_acct_overquota);
	426
94139027 PNA	427	static int __init nfnl_acct_init(void)
	428	{
	429	int ret;
	430
	431	pr_info("nfnl_acct: registering with nfnetlink.\n");
	432	ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
	433	if (ret < 0) {
	434	pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
	435	goto err_out;
	436	}
	437	return 0;
	438	err_out:
	439	return ret;
	440	}
	441
	442	static void __exit nfnl_acct_exit(void)
	443	{
	444	struct nf_acct cur, tmp;
	445
	446	pr_info("nfnl_acct: unregistering from nfnetlink.\n");
	447	nfnetlink_subsys_unregister(&nfnl_acct_subsys);
	448
	449	list_for_each_entry_safe(cur, tmp, &nfnl_acct_list, head) {
	450	list_del_rcu(&cur->head);
	451	/* We are sure that our objects have no clients at this point,
	452	* it's safe to release them all without checking refcnt. */
	453	kfree_rcu(cur, rcu_head);
	454	}
	455	}
	456
	457	module_init(nfnl_acct_init);
	458	module_exit(nfnl_acct_exit);