[mirror_ubuntu-bionic-kernel.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/refcount.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");

struct nf_acct {
	atomic64_t		pkts;
	atomic64_t		bytes;
	unsigned long		flags;
	struct list_head	head;
	refcount_t		refcnt;
	char			name[NFACCT_NAME_MAX];
	struct rcu_head		rcu_head;
	char			data[0];
};

struct nfacct_filter {
	u32 value;
	u32 mask;
};

#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 net *net, 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, &net->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;
		if ((flags & NFACCT_F_QUOTA) && !tb[NFACCT_QUOTA])
			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])));
	}
	refcount_set(&nfacct->refcnt, 1);
	list_add_tail_rcu(&nfacct->head, &net->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),
			 NFACCT_PAD) ||
	    nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes),
			 NFACCT_PAD) ||
	    nla_put_be32(skb, NFACCT_USE, htonl(refcount_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),
				 NFACCT_PAD))
			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 net *net = sock_net(skb->sk);
	struct nf_acct *cur, *last;
	const struct nfacct_filter *filter = cb->data;

	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, &net->nfnl_acct_list, head) {
		if (last) {
			if (cur != last)
				continue;

			last = NULL;
		}

		if (filter && (cur->flags & filter->mask) != filter->value)
			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_done(struct netlink_callback *cb)
{
	kfree(cb->data);
	return 0;
}

static const struct nla_policy filter_policy[NFACCT_FILTER_MAX + 1] = {
	[NFACCT_FILTER_MASK]	= { .type = NLA_U32 },
	[NFACCT_FILTER_VALUE]	= { .type = NLA_U32 },
};

static struct nfacct_filter *
nfacct_filter_alloc(const struct nlattr * const attr)
{
	struct nfacct_filter *filter;
	struct nlattr *tb[NFACCT_FILTER_MAX + 1];
	int err;

	err = nla_parse_nested(tb, NFACCT_FILTER_MAX, attr, filter_policy,
			       NULL);
	if (err < 0)
		return ERR_PTR(err);

	if (!tb[NFACCT_FILTER_MASK] || !tb[NFACCT_FILTER_VALUE])
		return ERR_PTR(-EINVAL);

	filter = kzalloc(sizeof(struct nfacct_filter), GFP_KERNEL);
	if (!filter)
		return ERR_PTR(-ENOMEM);

	filter->mask = ntohl(nla_get_be32(tb[NFACCT_FILTER_MASK]));
	filter->value = ntohl(nla_get_be32(tb[NFACCT_FILTER_VALUE]));

	return filter;
}

static int nfnl_acct_get(struct net *net, 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,
			.done = nfnl_acct_done,
		};

		if (tb[NFACCT_FILTER]) {
			struct nfacct_filter *filter;

			filter = nfacct_filter_alloc(tb[NFACCT_FILTER]);
			if (IS_ERR(filter))
				return PTR_ERR(filter);

			c.data = filter;
		}
		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, &net->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_put. So only when the current
	 * refcnt is 1, we decrease it to 0.
	 */
	if (refcount_dec_if_one(&cur->refcnt)) {
		/* We are protected by nfnl mutex. */
		list_del_rcu(&cur->head);
		kfree_rcu(cur, rcu_head);
	} else {
		ret = -EBUSY;
	}
	return ret;
}

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

	if (!tb[NFACCT_NAME]) {
		list_for_each_entry_safe(cur, tmp, &net->nfnl_acct_list, head)
			nfnl_acct_try_del(cur);

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

	list_for_each_entry(cur, &net->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 },
	[NFACCT_FILTER] = {.type = NLA_NESTED },
};

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

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

		if (!try_module_get(THIS_MODULE))
			goto err;

		if (!refcount_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)
{
	if (refcount_dec_and_test(&acct->refcnt))
		kfree_rcu(acct, rcu_head);

	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 net *net, 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(net->nfnl, skb, 0, NFNLGRP_ACCT_QUOTA,
			  GFP_ATOMIC);
}

int nfnl_acct_overquota(struct net *net, 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(net, nfacct);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(nfnl_acct_overquota);

static int __net_init nfnl_acct_net_init(struct net *net)
{
	INIT_LIST_HEAD(&net->nfnl_acct_list);

	return 0;
}

static void __net_exit nfnl_acct_net_exit(struct net *net)
{
	struct nf_acct *cur, *tmp;

	list_for_each_entry_safe(cur, tmp, &net->nfnl_acct_list, head) {
		list_del_rcu(&cur->head);

		if (refcount_dec_and_test(&cur->refcnt))
			kfree_rcu(cur, rcu_head);
	}
}

static struct pernet_operations nfnl_acct_ops = {
        .init   = nfnl_acct_net_init,
        .exit   = nfnl_acct_net_exit,
};

static int __init nfnl_acct_init(void)
{
	int ret;

	ret = register_pernet_subsys(&nfnl_acct_ops);
	if (ret < 0) {
		pr_err("nfnl_acct_init: failed to register pernet ops\n");
		goto err_out;
	}

	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 cleanup_pernet;
	}
	return 0;

cleanup_pernet:
	unregister_pernet_subsys(&nfnl_acct_ops);
err_out:
	return ret;
}

static void __exit nfnl_acct_exit(void)
{
	pr_info("nfnl_acct: unregistering from nfnetlink.\n");
	nfnetlink_subsys_unregister(&nfnl_acct_subsys);
	unregister_pernet_subsys(&nfnl_acct_ops);
}

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>
b54ab92b	14	#include <linux/refcount.h>
94139027 PNA	15	#include <linux/netlink.h>
	16	#include <linux/rculist.h>
	17	#include <linux/slab.h>
	18	#include <linux/types.h>
	19	#include <linux/errno.h>
	20	#include <net/netlink.h>
	21	#include <net/sock.h>
94139027 PNA	22
	23	#include <linux/netfilter.h>
	24	#include <linux/netfilter/nfnetlink.h>
	25	#include <linux/netfilter/nfnetlink_acct.h>
	26
	27	MODULE_LICENSE("GPL");
	28	MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
	29	MODULE_DESCRIPTION("nfacct: Extended Netfilter accounting infrastructure");
	30
94139027 PNA	31	struct nf_acct {
	32	atomic64_t pkts;
	33	atomic64_t bytes;
683399ed	34	unsigned long flags;
94139027	35	struct list_head head;
b54ab92b	36	refcount_t refcnt;
94139027 PNA	37	char name[NFACCT_NAME_MAX];
94139027 PNA	38	struct rcu_head rcu_head;
683399ed	39	char data[0];
94139027 PNA	40	};
94139027 PNA	41
f111f780 AP	42	struct nfacct_filter {
	43	u32 value;
	44	u32 mask;
	45	};
	46
683399ed	47	#define NFACCT_F_QUOTA (NFACCT_F_QUOTA_PKTS \| NFACCT_F_QUOTA_BYTES)
b6d04688	48	#define NFACCT_OVERQUOTA_BIT 2 /* NFACCT_F_OVERQUOTA */
683399ed	49
7b8002a1 PNA	50	static int nfnl_acct_new(struct net net, struct sock nfnl,
	51	struct sk_buff skb, const struct nlmsghdr nlh,
	52	const struct nlattr * const tb[])
94139027 PNA	53	{
	54	struct nf_acct nfacct, matching = NULL;
	55	char *acct_name;
683399ed MP	56	unsigned int size = 0;
683399ed MP	57	u32 flags = 0;
94139027 PNA	58
	59	if (!tb[NFACCT_NAME])
	60	return -EINVAL;
	61
	62	acct_name = nla_data(tb[NFACCT_NAME]);
deadcfc3 PNA	63	if (strlen(acct_name) == 0)
deadcfc3 PNA	64	return -EINVAL;
94139027	65
3499abb2	66	list_for_each_entry(nfacct, &net->nfnl_acct_list, head) {
94139027 PNA	67	if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
	68	continue;
	69
	70	if (nlh->nlmsg_flags & NLM_F_EXCL)
	71	return -EEXIST;
	72
	73	matching = nfacct;
	74	break;
	75	}
	76
	77	if (matching) {
	78	if (nlh->nlmsg_flags & NLM_F_REPLACE) {
	79	/* reset counters if you request a replacement. */
	80	atomic64_set(&matching->pkts, 0);
	81	atomic64_set(&matching->bytes, 0);
f9da455b	82	smp_mb__before_atomic();
683399ed MP	83	/* reset overquota flag if quota is enabled. */
683399ed MP	84	if ((matching->flags & NFACCT_F_QUOTA))
b6d04688 AP	85	clear_bit(NFACCT_OVERQUOTA_BIT,
b6d04688 AP	86	&matching->flags);
94139027 PNA	87	return 0;
	88	}
	89	return -EBUSY;
	90	}
	91
683399ed MP	92	if (tb[NFACCT_FLAGS]) {
	93	flags = ntohl(nla_get_be32(tb[NFACCT_FLAGS]));
	94	if (flags & ~NFACCT_F_QUOTA)
	95	return -EOPNOTSUPP;
	96	if ((flags & NFACCT_F_QUOTA) == NFACCT_F_QUOTA)
	97	return -EINVAL;
	98	if (flags & NFACCT_F_OVERQUOTA)
	99	return -EINVAL;
eda3fc50 PT	100	if ((flags & NFACCT_F_QUOTA) && !tb[NFACCT_QUOTA])
eda3fc50 PT	101	return -EINVAL;
683399ed MP	102
	103	size += sizeof(u64);
	104	}
	105
	106	nfacct = kzalloc(sizeof(struct nf_acct) + size, GFP_KERNEL);
94139027 PNA	107	if (nfacct == NULL)
	108	return -ENOMEM;
	109
683399ed MP	110	if (flags & NFACCT_F_QUOTA) {
	111	u64 quota = (u64 )nfacct->data;
	112
	113	*quota = be64_to_cpu(nla_get_be64(tb[NFACCT_QUOTA]));
	114	nfacct->flags = flags;
	115	}
	116
94139027 PNA	117	strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
	118
	119	if (tb[NFACCT_BYTES]) {
	120	atomic64_set(&nfacct->bytes,
fe31d1a8	121	be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES])));
94139027 PNA	122	}
	123	if (tb[NFACCT_PKTS]) {
	124	atomic64_set(&nfacct->pkts,
fe31d1a8	125	be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS])));
94139027	126	}
b54ab92b	127	refcount_set(&nfacct->refcnt, 1);
3499abb2	128	list_add_tail_rcu(&nfacct->head, &net->nfnl_acct_list);
94139027 PNA	129	return 0;
	130	}
	131
	132	static int
15e47304	133	nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
94139027 PNA	134	int event, struct nf_acct *acct)
	135	{
	136	struct nlmsghdr *nlh;
	137	struct nfgenmsg *nfmsg;
15e47304	138	unsigned int flags = portid ? NLM_F_MULTI : 0;
94139027	139	u64 pkts, bytes;
d24675cb	140	u32 old_flags;
94139027 PNA	141
94139027 PNA	142	event \|= NFNL_SUBSYS_ACCT << 8;
15e47304	143	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
94139027 PNA	144	if (nlh == NULL)
	145	goto nlmsg_failure;
	146
	147	nfmsg = nlmsg_data(nlh);
	148	nfmsg->nfgen_family = AF_UNSPEC;
	149	nfmsg->version = NFNETLINK_V0;
	150	nfmsg->res_id = 0;
	151
7c801189 DM	152	if (nla_put_string(skb, NFACCT_NAME, acct->name))
7c801189 DM	153	goto nla_put_failure;
94139027	154
d24675cb	155	old_flags = acct->flags;
94139027 PNA	156	if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
	157	pkts = atomic64_xchg(&acct->pkts, 0);
	158	bytes = atomic64_xchg(&acct->bytes, 0);
f9da455b	159	smp_mb__before_atomic();
683399ed	160	if (acct->flags & NFACCT_F_QUOTA)
b6d04688	161	clear_bit(NFACCT_OVERQUOTA_BIT, &acct->flags);
94139027 PNA	162	} else {
	163	pkts = atomic64_read(&acct->pkts);
	164	bytes = atomic64_read(&acct->bytes);
	165	}
b46f6ded ND	166	if (nla_put_be64(skb, NFACCT_PKTS, cpu_to_be64(pkts),
	167	NFACCT_PAD) \|\|
	168	nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes),
	169	NFACCT_PAD) \|\|
b54ab92b	170	nla_put_be32(skb, NFACCT_USE, htonl(refcount_read(&acct->refcnt))))
7c801189	171	goto nla_put_failure;
683399ed MP	172	if (acct->flags & NFACCT_F_QUOTA) {
683399ed MP	173	u64 quota = (u64 )acct->data;
94139027	174
d24675cb	175	if (nla_put_be32(skb, NFACCT_FLAGS, htonl(old_flags)) \|\|
b46f6ded ND	176	nla_put_be64(skb, NFACCT_QUOTA, cpu_to_be64(*quota),
b46f6ded ND	177	NFACCT_PAD))
683399ed MP	178	goto nla_put_failure;
683399ed MP	179	}
94139027 PNA	180	nlmsg_end(skb, nlh);
	181	return skb->len;
	182
	183	nlmsg_failure:
	184	nla_put_failure:
	185	nlmsg_cancel(skb, nlh);
	186	return -1;
	187	}
	188
	189	static int
	190	nfnl_acct_dump(struct sk_buff skb, struct netlink_callback cb)
	191	{
3499abb2	192	struct net *net = sock_net(skb->sk);
94139027	193	struct nf_acct cur, last;
f111f780	194	const struct nfacct_filter *filter = cb->data;
94139027 PNA	195
	196	if (cb->args[2])
	197	return 0;
	198
	199	last = (struct nf_acct *)cb->args[1];
	200	if (cb->args[1])
	201	cb->args[1] = 0;
	202
	203	rcu_read_lock();
3499abb2	204	list_for_each_entry_rcu(cur, &net->nfnl_acct_list, head) {
991a6b73 PNA	205	if (last) {
	206	if (cur != last)
	207	continue;
94139027	208
991a6b73 PNA	209	last = NULL;
991a6b73 PNA	210	}
f111f780 AP	211
	212	if (filter && (cur->flags & filter->mask) != filter->value)
	213	continue;
	214
15e47304	215	if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid,
94139027 PNA	216	cb->nlh->nlmsg_seq,
	217	NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
	218	NFNL_MSG_ACCT_NEW, cur) < 0) {
	219	cb->args[1] = (unsigned long)cur;
	220	break;
	221	}
	222	}
	223	if (!cb->args[1])
	224	cb->args[2] = 1;
	225	rcu_read_unlock();
	226	return skb->len;
	227	}
	228
f111f780 AP	229	static int nfnl_acct_done(struct netlink_callback *cb)
	230	{
	231	kfree(cb->data);
	232	return 0;
	233	}
	234
	235	static const struct nla_policy filter_policy[NFACCT_FILTER_MAX + 1] = {
	236	[NFACCT_FILTER_MASK] = { .type = NLA_U32 },
	237	[NFACCT_FILTER_VALUE] = { .type = NLA_U32 },
	238	};
	239
	240	static struct nfacct_filter *
	241	nfacct_filter_alloc(const struct nlattr * const attr)
	242	{
	243	struct nfacct_filter *filter;
	244	struct nlattr *tb[NFACCT_FILTER_MAX + 1];
	245	int err;
	246
fceb6435 JB	247	err = nla_parse_nested(tb, NFACCT_FILTER_MAX, attr, filter_policy,
fceb6435 JB	248	NULL);
f111f780 AP	249	if (err < 0)
	250	return ERR_PTR(err);
	251
017b1b6d PT	252	if (!tb[NFACCT_FILTER_MASK] \|\| !tb[NFACCT_FILTER_VALUE])
	253	return ERR_PTR(-EINVAL);
	254
f111f780 AP	255	filter = kzalloc(sizeof(struct nfacct_filter), GFP_KERNEL);
	256	if (!filter)
	257	return ERR_PTR(-ENOMEM);
	258
	259	filter->mask = ntohl(nla_get_be32(tb[NFACCT_FILTER_MASK]));
	260	filter->value = ntohl(nla_get_be32(tb[NFACCT_FILTER_VALUE]));
	261
	262	return filter;
	263	}
	264
7b8002a1 PNA	265	static int nfnl_acct_get(struct net net, struct sock nfnl,
	266	struct sk_buff skb, const struct nlmsghdr nlh,
	267	const struct nlattr * const tb[])
94139027	268	{
3ab0b245	269	int ret = -ENOENT;
94139027 PNA	270	struct nf_acct *cur;
	271	char *acct_name;
	272
	273	if (nlh->nlmsg_flags & NLM_F_DUMP) {
80d326fa PNA	274	struct netlink_dump_control c = {
80d326fa PNA	275	.dump = nfnl_acct_dump,
f111f780	276	.done = nfnl_acct_done,
80d326fa	277	};
f111f780 AP	278
	279	if (tb[NFACCT_FILTER]) {
	280	struct nfacct_filter *filter;
	281
	282	filter = nfacct_filter_alloc(tb[NFACCT_FILTER]);
	283	if (IS_ERR(filter))
	284	return PTR_ERR(filter);
	285
	286	c.data = filter;
	287	}
80d326fa	288	return netlink_dump_start(nfnl, skb, nlh, &c);
94139027 PNA	289	}
	290
	291	if (!tb[NFACCT_NAME])
	292	return -EINVAL;
	293	acct_name = nla_data(tb[NFACCT_NAME]);
	294
3499abb2	295	list_for_each_entry(cur, &net->nfnl_acct_list, head) {
94139027 PNA	296	struct sk_buff *skb2;
	297
	298	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
	299	continue;
	300
	301	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
3ab0b245 PNA	302	if (skb2 == NULL) {
3ab0b245 PNA	303	ret = -ENOMEM;
94139027	304	break;
3ab0b245	305	}
94139027	306
15e47304	307	ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid,
94139027 PNA	308	nlh->nlmsg_seq,
	309	NFNL_MSG_TYPE(nlh->nlmsg_type),
	310	NFNL_MSG_ACCT_NEW, cur);
3ab0b245	311	if (ret <= 0) {
94139027	312	kfree_skb(skb2);
3ab0b245 PNA	313	break;
3ab0b245 PNA	314	}
15e47304	315	ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
3ab0b245 PNA	316	MSG_DONTWAIT);
	317	if (ret > 0)
	318	ret = 0;
94139027	319
3ab0b245 PNA	320	/* this avoids a loop in nfnetlink. */
3ab0b245 PNA	321	return ret == -EAGAIN ? -ENOBUFS : ret;
94139027 PNA	322	}
	323	return ret;
	324	}
	325
	326	/* try to delete object, fail if it is still in use. */
	327	static int nfnl_acct_try_del(struct nf_acct *cur)
	328	{
	329	int ret = 0;
	330
12be15dd LZ	331	/* We want to avoid races with nfnl_acct_put. So only when the current
	332	* refcnt is 1, we decrease it to 0.
	333	*/
b54ab92b	334	if (refcount_dec_if_one(&cur->refcnt)) {
94139027 PNA	335	/* We are protected by nfnl mutex. */
	336	list_del_rcu(&cur->head);
	337	kfree_rcu(cur, rcu_head);
	338	} else {
94139027 PNA	339	ret = -EBUSY;
	340	}
	341	return ret;
	342	}
	343
7b8002a1 PNA	344	static int nfnl_acct_del(struct net net, struct sock nfnl,
	345	struct sk_buff skb, const struct nlmsghdr nlh,
	346	const struct nlattr * const tb[])
94139027	347	{
93fac10b	348	struct nf_acct cur, tmp;
94139027	349	int ret = -ENOENT;
93fac10b	350	char *acct_name;
94139027 PNA	351
94139027 PNA	352	if (!tb[NFACCT_NAME]) {
93fac10b	353	list_for_each_entry_safe(cur, tmp, &net->nfnl_acct_list, head)
94139027 PNA	354	nfnl_acct_try_del(cur);
	355
	356	return 0;
	357	}
	358	acct_name = nla_data(tb[NFACCT_NAME]);
	359
3499abb2	360	list_for_each_entry(cur, &net->nfnl_acct_list, head) {
94139027 PNA	361	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
	362	continue;
	363
	364	ret = nfnl_acct_try_del(cur);
	365	if (ret < 0)
	366	return ret;
	367
	368	break;
	369	}
	370	return ret;
	371	}
	372
	373	static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
	374	[NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
	375	[NFACCT_BYTES] = { .type = NLA_U64 },
	376	[NFACCT_PKTS] = { .type = NLA_U64 },
683399ed MP	377	[NFACCT_FLAGS] = { .type = NLA_U32 },
683399ed MP	378	[NFACCT_QUOTA] = { .type = NLA_U64 },
f111f780	379	[NFACCT_FILTER] = {.type = NLA_NESTED },
94139027 PNA	380	};
	381
	382	static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
	383	[NFNL_MSG_ACCT_NEW] = { .call = nfnl_acct_new,
	384	.attr_count = NFACCT_MAX,
	385	.policy = nfnl_acct_policy },
	386	[NFNL_MSG_ACCT_GET] = { .call = nfnl_acct_get,
	387	.attr_count = NFACCT_MAX,
	388	.policy = nfnl_acct_policy },
	389	[NFNL_MSG_ACCT_GET_CTRZERO] = { .call = nfnl_acct_get,
	390	.attr_count = NFACCT_MAX,
	391	.policy = nfnl_acct_policy },
	392	[NFNL_MSG_ACCT_DEL] = { .call = nfnl_acct_del,
	393	.attr_count = NFACCT_MAX,
	394	.policy = nfnl_acct_policy },
	395	};
	396
	397	static const struct nfnetlink_subsystem nfnl_acct_subsys = {
	398	.name = "acct",
	399	.subsys_id = NFNL_SUBSYS_ACCT,
	400	.cb_count = NFNL_MSG_ACCT_MAX,
	401	.cb = nfnl_acct_cb,
	402	};
	403
	404	MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
	405
3499abb2	406	struct nf_acct nfnl_acct_find_get(struct net net, const char *acct_name)
94139027 PNA	407	{
	408	struct nf_acct cur, acct = NULL;
	409
	410	rcu_read_lock();
3499abb2	411	list_for_each_entry_rcu(cur, &net->nfnl_acct_list, head) {
94139027 PNA	412	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
	413	continue;
	414
	415	if (!try_module_get(THIS_MODULE))
	416	goto err;
	417
b54ab92b	418	if (!refcount_inc_not_zero(&cur->refcnt)) {
94139027 PNA	419	module_put(THIS_MODULE);
	420	goto err;
	421	}
	422
	423	acct = cur;
	424	break;
	425	}
	426	err:
	427	rcu_read_unlock();
	428	return acct;
	429	}
	430	EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
	431
	432	void nfnl_acct_put(struct nf_acct *acct)
	433	{
b54ab92b	434	if (refcount_dec_and_test(&acct->refcnt))
3499abb2 AS	435	kfree_rcu(acct, rcu_head);
3499abb2 AS	436
94139027 PNA	437	module_put(THIS_MODULE);
	438	}
	439	EXPORT_SYMBOL_GPL(nfnl_acct_put);
	440
	441	void nfnl_acct_update(const struct sk_buff skb, struct nf_acct nfacct)
	442	{
	443	atomic64_inc(&nfacct->pkts);
	444	atomic64_add(skb->len, &nfacct->bytes);
	445	}
	446	EXPORT_SYMBOL_GPL(nfnl_acct_update);
	447
aca30018	448	static void nfnl_overquota_report(struct net net, struct nf_acct nfacct)
683399ed MP	449	{
	450	int ret;
	451	struct sk_buff *skb;
	452
	453	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
	454	if (skb == NULL)
	455	return;
	456
	457	ret = nfnl_acct_fill_info(skb, 0, 0, NFNL_MSG_ACCT_OVERQUOTA, 0,
	458	nfacct);
	459	if (ret <= 0) {
	460	kfree_skb(skb);
	461	return;
	462	}
aca30018	463	netlink_broadcast(net->nfnl, skb, 0, NFNLGRP_ACCT_QUOTA,
683399ed MP	464	GFP_ATOMIC);
	465	}
	466
aca30018 LZ	467	int nfnl_acct_overquota(struct net net, const struct sk_buff skb,
aca30018 LZ	468	struct nf_acct *nfacct)
683399ed MP	469	{
	470	u64 now;
	471	u64 *quota;
	472	int ret = NFACCT_UNDERQUOTA;
	473
	474	/* no place here if we don't have a quota */
	475	if (!(nfacct->flags & NFACCT_F_QUOTA))
	476	return NFACCT_NO_QUOTA;
	477
	478	quota = (u64 *)nfacct->data;
	479	now = (nfacct->flags & NFACCT_F_QUOTA_PKTS) ?
	480	atomic64_read(&nfacct->pkts) : atomic64_read(&nfacct->bytes);
	481
	482	ret = now > *quota;
	483
	484	if (now >= *quota &&
b6d04688	485	!test_and_set_bit(NFACCT_OVERQUOTA_BIT, &nfacct->flags)) {
aca30018	486	nfnl_overquota_report(net, nfacct);
683399ed MP	487	}
	488
	489	return ret;
	490	}
	491	EXPORT_SYMBOL_GPL(nfnl_acct_overquota);
	492
3499abb2 AS	493	static int __net_init nfnl_acct_net_init(struct net *net)
	494	{
	495	INIT_LIST_HEAD(&net->nfnl_acct_list);
	496
	497	return 0;
	498	}
	499
	500	static void __net_exit nfnl_acct_net_exit(struct net *net)
	501	{
	502	struct nf_acct cur, tmp;
	503
	504	list_for_each_entry_safe(cur, tmp, &net->nfnl_acct_list, head) {
	505	list_del_rcu(&cur->head);
	506
b54ab92b	507	if (refcount_dec_and_test(&cur->refcnt))
3499abb2 AS	508	kfree_rcu(cur, rcu_head);
	509	}
	510	}
	511
	512	static struct pernet_operations nfnl_acct_ops = {
	513	.init = nfnl_acct_net_init,
	514	.exit = nfnl_acct_net_exit,
	515	};
	516
94139027 PNA	517	static int __init nfnl_acct_init(void)
	518	{
	519	int ret;
	520
3499abb2 AS	521	ret = register_pernet_subsys(&nfnl_acct_ops);
	522	if (ret < 0) {
	523	pr_err("nfnl_acct_init: failed to register pernet ops\n");
	524	goto err_out;
	525	}
	526
94139027 PNA	527	pr_info("nfnl_acct: registering with nfnetlink.\n");
	528	ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
	529	if (ret < 0) {
	530	pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
3499abb2	531	goto cleanup_pernet;
94139027 PNA	532	}
94139027 PNA	533	return 0;
3499abb2 AS	534
	535	cleanup_pernet:
	536	unregister_pernet_subsys(&nfnl_acct_ops);
94139027 PNA	537	err_out:
	538	return ret;
	539	}
	540
	541	static void __exit nfnl_acct_exit(void)
	542	{
94139027 PNA	543	pr_info("nfnl_acct: unregistering from nfnetlink.\n");
94139027 PNA	544	nfnetlink_subsys_unregister(&nfnl_acct_subsys);
3499abb2	545	unregister_pernet_subsys(&nfnl_acct_ops);
94139027 PNA	546	}
	547
	548	module_init(nfnl_acct_init);
	549	module_exit(nfnl_acct_exit);