[mirror_ubuntu-jammy-kernel.git] / net / netfilter / nfnetlink_acct.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
 * (C) 2011 Intra2net AG <http://www.intra2net.com>
 */
#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 netlink_ext_ack *extack)
{
	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;
	}

	nla_strlcpy(nfacct->name, 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_msg_type(NFNL_SUBSYS_ACCT, event);
	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 int nfnl_acct_start(struct netlink_callback *cb)
{
	const struct nlattr *const attr = cb->data;
	struct nlattr *tb[NFACCT_FILTER_MAX + 1];
	struct nfacct_filter *filter;
	int err;

	if (!attr)
		return 0;

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

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

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

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

	return 0;
}

static int nfnl_acct_get(struct net *net, struct sock *nfnl,
			 struct sk_buff *skb, const struct nlmsghdr *nlh,
			 const struct nlattr * const tb[],
			 struct netlink_ext_ack *extack)
{
	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,
			.start = nfnl_acct_start,
			.done = nfnl_acct_done,
			.data = (void *)tb[NFACCT_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 netlink_ext_ack *extack)
{
	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, 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;
	}

	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)
{
	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
e97150df	1	// SPDX-License-Identifier: GPL-2.0-or-later
94139027 PNA	2	/*
	3	* (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
	4	* (C) 2011 Intra2net AG <http://www.intra2net.com>
94139027 PNA	5	*/
	6	#include <linux/init.h>
	7	#include <linux/module.h>
	8	#include <linux/kernel.h>
	9	#include <linux/skbuff.h>
6523cf9a	10	#include <linux/atomic.h>
b54ab92b	11	#include <linux/refcount.h>
94139027 PNA	12	#include <linux/netlink.h>
	13	#include <linux/rculist.h>
	14	#include <linux/slab.h>
	15	#include <linux/types.h>
	16	#include <linux/errno.h>
	17	#include <net/netlink.h>
	18	#include <net/sock.h>
94139027 PNA	19
	20	#include <linux/netfilter.h>
	21	#include <linux/netfilter/nfnetlink.h>
	22	#include <linux/netfilter/nfnetlink_acct.h>
	23
	24	MODULE_LICENSE("GPL");
	25	MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
	26	MODULE_DESCRIPTION("nfacct: Extended Netfilter accounting infrastructure");
	27
94139027 PNA	28	struct nf_acct {
	29	atomic64_t pkts;
	30	atomic64_t bytes;
683399ed	31	unsigned long flags;
94139027	32	struct list_head head;
b54ab92b	33	refcount_t refcnt;
94139027 PNA	34	char name[NFACCT_NAME_MAX];
94139027 PNA	35	struct rcu_head rcu_head;
683399ed	36	char data[0];
94139027 PNA	37	};
94139027 PNA	38
f111f780 AP	39	struct nfacct_filter {
	40	u32 value;
	41	u32 mask;
	42	};
	43
683399ed	44	#define NFACCT_F_QUOTA (NFACCT_F_QUOTA_PKTS \| NFACCT_F_QUOTA_BYTES)
b6d04688	45	#define NFACCT_OVERQUOTA_BIT 2 /* NFACCT_F_OVERQUOTA */
683399ed	46
7b8002a1 PNA	47	static int nfnl_acct_new(struct net net, struct sock nfnl,
7b8002a1 PNA	48	struct sk_buff skb, const struct nlmsghdr nlh,
04ba724b PNA	49	const struct nlattr * const tb[],
04ba724b PNA	50	struct netlink_ext_ack *extack)
94139027 PNA	51	{
	52	struct nf_acct nfacct, matching = NULL;
	53	char *acct_name;
683399ed MP	54	unsigned int size = 0;
683399ed MP	55	u32 flags = 0;
94139027 PNA	56
	57	if (!tb[NFACCT_NAME])
	58	return -EINVAL;
	59
	60	acct_name = nla_data(tb[NFACCT_NAME]);
deadcfc3 PNA	61	if (strlen(acct_name) == 0)
deadcfc3 PNA	62	return -EINVAL;
94139027	63
3499abb2	64	list_for_each_entry(nfacct, &net->nfnl_acct_list, head) {
94139027 PNA	65	if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
	66	continue;
	67
	68	if (nlh->nlmsg_flags & NLM_F_EXCL)
	69	return -EEXIST;
	70
	71	matching = nfacct;
	72	break;
	73	}
	74
	75	if (matching) {
	76	if (nlh->nlmsg_flags & NLM_F_REPLACE) {
	77	/* reset counters if you request a replacement. */
	78	atomic64_set(&matching->pkts, 0);
	79	atomic64_set(&matching->bytes, 0);
f9da455b	80	smp_mb__before_atomic();
683399ed MP	81	/* reset overquota flag if quota is enabled. */
683399ed MP	82	if ((matching->flags & NFACCT_F_QUOTA))
b6d04688 AP	83	clear_bit(NFACCT_OVERQUOTA_BIT,
b6d04688 AP	84	&matching->flags);
94139027 PNA	85	return 0;
	86	}
	87	return -EBUSY;
	88	}
	89
683399ed MP	90	if (tb[NFACCT_FLAGS]) {
	91	flags = ntohl(nla_get_be32(tb[NFACCT_FLAGS]));
	92	if (flags & ~NFACCT_F_QUOTA)
	93	return -EOPNOTSUPP;
	94	if ((flags & NFACCT_F_QUOTA) == NFACCT_F_QUOTA)
	95	return -EINVAL;
	96	if (flags & NFACCT_F_OVERQUOTA)
	97	return -EINVAL;
eda3fc50 PT	98	if ((flags & NFACCT_F_QUOTA) && !tb[NFACCT_QUOTA])
eda3fc50 PT	99	return -EINVAL;
683399ed MP	100
	101	size += sizeof(u64);
	102	}
	103
	104	nfacct = kzalloc(sizeof(struct nf_acct) + size, GFP_KERNEL);
94139027 PNA	105	if (nfacct == NULL)
	106	return -ENOMEM;
	107
683399ed MP	108	if (flags & NFACCT_F_QUOTA) {
	109	u64 quota = (u64 )nfacct->data;
	110
	111	*quota = be64_to_cpu(nla_get_be64(tb[NFACCT_QUOTA]));
	112	nfacct->flags = flags;
	113	}
	114
4b83a904	115	nla_strlcpy(nfacct->name, tb[NFACCT_NAME], NFACCT_NAME_MAX);
94139027 PNA	116
	117	if (tb[NFACCT_BYTES]) {
	118	atomic64_set(&nfacct->bytes,
fe31d1a8	119	be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES])));
94139027 PNA	120	}
	121	if (tb[NFACCT_PKTS]) {
	122	atomic64_set(&nfacct->pkts,
fe31d1a8	123	be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS])));
94139027	124	}
b54ab92b	125	refcount_set(&nfacct->refcnt, 1);
3499abb2	126	list_add_tail_rcu(&nfacct->head, &net->nfnl_acct_list);
94139027 PNA	127	return 0;
	128	}
	129
	130	static int
15e47304	131	nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
94139027 PNA	132	int event, struct nf_acct *acct)
	133	{
	134	struct nlmsghdr *nlh;
	135	struct nfgenmsg *nfmsg;
15e47304	136	unsigned int flags = portid ? NLM_F_MULTI : 0;
94139027	137	u64 pkts, bytes;
d24675cb	138	u32 old_flags;
94139027	139
dedb67c4	140	event = nfnl_msg_type(NFNL_SUBSYS_ACCT, event);
15e47304	141	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
94139027 PNA	142	if (nlh == NULL)
	143	goto nlmsg_failure;
	144
	145	nfmsg = nlmsg_data(nlh);
	146	nfmsg->nfgen_family = AF_UNSPEC;
	147	nfmsg->version = NFNETLINK_V0;
	148	nfmsg->res_id = 0;
	149
7c801189 DM	150	if (nla_put_string(skb, NFACCT_NAME, acct->name))
7c801189 DM	151	goto nla_put_failure;
94139027	152
d24675cb	153	old_flags = acct->flags;
94139027 PNA	154	if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
	155	pkts = atomic64_xchg(&acct->pkts, 0);
	156	bytes = atomic64_xchg(&acct->bytes, 0);
f9da455b	157	smp_mb__before_atomic();
683399ed	158	if (acct->flags & NFACCT_F_QUOTA)
b6d04688	159	clear_bit(NFACCT_OVERQUOTA_BIT, &acct->flags);
94139027 PNA	160	} else {
	161	pkts = atomic64_read(&acct->pkts);
	162	bytes = atomic64_read(&acct->bytes);
	163	}
b46f6ded ND	164	if (nla_put_be64(skb, NFACCT_PKTS, cpu_to_be64(pkts),
	165	NFACCT_PAD) \|\|
	166	nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes),
	167	NFACCT_PAD) \|\|
b54ab92b	168	nla_put_be32(skb, NFACCT_USE, htonl(refcount_read(&acct->refcnt))))
7c801189	169	goto nla_put_failure;
683399ed MP	170	if (acct->flags & NFACCT_F_QUOTA) {
683399ed MP	171	u64 quota = (u64 )acct->data;
94139027	172
d24675cb	173	if (nla_put_be32(skb, NFACCT_FLAGS, htonl(old_flags)) \|\|
b46f6ded ND	174	nla_put_be64(skb, NFACCT_QUOTA, cpu_to_be64(*quota),
b46f6ded ND	175	NFACCT_PAD))
683399ed MP	176	goto nla_put_failure;
683399ed MP	177	}
94139027 PNA	178	nlmsg_end(skb, nlh);
	179	return skb->len;
	180
	181	nlmsg_failure:
	182	nla_put_failure:
	183	nlmsg_cancel(skb, nlh);
	184	return -1;
	185	}
	186
	187	static int
	188	nfnl_acct_dump(struct sk_buff skb, struct netlink_callback cb)
	189	{
3499abb2	190	struct net *net = sock_net(skb->sk);
94139027	191	struct nf_acct cur, last;
f111f780	192	const struct nfacct_filter *filter = cb->data;
94139027 PNA	193
	194	if (cb->args[2])
	195	return 0;
	196
	197	last = (struct nf_acct *)cb->args[1];
	198	if (cb->args[1])
	199	cb->args[1] = 0;
	200
	201	rcu_read_lock();
3499abb2	202	list_for_each_entry_rcu(cur, &net->nfnl_acct_list, head) {
991a6b73 PNA	203	if (last) {
	204	if (cur != last)
	205	continue;
94139027	206
991a6b73 PNA	207	last = NULL;
991a6b73 PNA	208	}
f111f780 AP	209
	210	if (filter && (cur->flags & filter->mask) != filter->value)
	211	continue;
	212
15e47304	213	if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid,
94139027 PNA	214	cb->nlh->nlmsg_seq,
	215	NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
	216	NFNL_MSG_ACCT_NEW, cur) < 0) {
	217	cb->args[1] = (unsigned long)cur;
	218	break;
	219	}
	220	}
	221	if (!cb->args[1])
	222	cb->args[2] = 1;
	223	rcu_read_unlock();
	224	return skb->len;
	225	}
	226
f111f780 AP	227	static int nfnl_acct_done(struct netlink_callback *cb)
	228	{
	229	kfree(cb->data);
	230	return 0;
	231	}
	232
	233	static const struct nla_policy filter_policy[NFACCT_FILTER_MAX + 1] = {
	234	[NFACCT_FILTER_MASK] = { .type = NLA_U32 },
	235	[NFACCT_FILTER_VALUE] = { .type = NLA_U32 },
	236	};
	237
3e673b23	238	static int nfnl_acct_start(struct netlink_callback *cb)
f111f780	239	{
3e673b23	240	const struct nlattr *const attr = cb->data;
f111f780	241	struct nlattr *tb[NFACCT_FILTER_MAX + 1];
3e673b23	242	struct nfacct_filter *filter;
f111f780 AP	243	int err;
f111f780 AP	244
3e673b23 FW	245	if (!attr)
	246	return 0;
	247
8cb08174 JB	248	err = nla_parse_nested_deprecated(tb, NFACCT_FILTER_MAX, attr,
8cb08174 JB	249	filter_policy, NULL);
f111f780	250	if (err < 0)
3e673b23	251	return err;
f111f780	252
017b1b6d	253	if (!tb[NFACCT_FILTER_MASK] \|\| !tb[NFACCT_FILTER_VALUE])
3e673b23	254	return -EINVAL;
017b1b6d	255
f111f780 AP	256	filter = kzalloc(sizeof(struct nfacct_filter), GFP_KERNEL);
f111f780 AP	257	if (!filter)
3e673b23	258	return -ENOMEM;
f111f780 AP	259
	260	filter->mask = ntohl(nla_get_be32(tb[NFACCT_FILTER_MASK]));
	261	filter->value = ntohl(nla_get_be32(tb[NFACCT_FILTER_VALUE]));
3e673b23	262	cb->data = filter;
f111f780	263
3e673b23	264	return 0;
f111f780 AP	265	}
f111f780 AP	266
7b8002a1 PNA	267	static int nfnl_acct_get(struct net net, struct sock nfnl,
7b8002a1 PNA	268	struct sk_buff skb, const struct nlmsghdr nlh,
04ba724b PNA	269	const struct nlattr * const tb[],
04ba724b PNA	270	struct netlink_ext_ack *extack)
94139027	271	{
3ab0b245	272	int ret = -ENOENT;
94139027 PNA	273	struct nf_acct *cur;
	274	char *acct_name;
	275
	276	if (nlh->nlmsg_flags & NLM_F_DUMP) {
80d326fa PNA	277	struct netlink_dump_control c = {
80d326fa PNA	278	.dump = nfnl_acct_dump,
3e673b23	279	.start = nfnl_acct_start,
f111f780	280	.done = nfnl_acct_done,
3e673b23	281	.data = (void *)tb[NFACCT_FILTER],
80d326fa	282	};
f111f780	283
80d326fa	284	return netlink_dump_start(nfnl, skb, nlh, &c);
94139027 PNA	285	}
	286
	287	if (!tb[NFACCT_NAME])
	288	return -EINVAL;
	289	acct_name = nla_data(tb[NFACCT_NAME]);
	290
3499abb2	291	list_for_each_entry(cur, &net->nfnl_acct_list, head) {
94139027 PNA	292	struct sk_buff *skb2;
	293
	294	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
	295	continue;
	296
	297	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
3ab0b245 PNA	298	if (skb2 == NULL) {
3ab0b245 PNA	299	ret = -ENOMEM;
94139027	300	break;
3ab0b245	301	}
94139027	302
15e47304	303	ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid,
94139027 PNA	304	nlh->nlmsg_seq,
	305	NFNL_MSG_TYPE(nlh->nlmsg_type),
	306	NFNL_MSG_ACCT_NEW, cur);
3ab0b245	307	if (ret <= 0) {
94139027	308	kfree_skb(skb2);
3ab0b245 PNA	309	break;
3ab0b245 PNA	310	}
15e47304	311	ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
3ab0b245 PNA	312	MSG_DONTWAIT);
	313	if (ret > 0)
	314	ret = 0;
94139027	315
3ab0b245 PNA	316	/* this avoids a loop in nfnetlink. */
3ab0b245 PNA	317	return ret == -EAGAIN ? -ENOBUFS : ret;
94139027 PNA	318	}
	319	return ret;
	320	}
	321
	322	/* try to delete object, fail if it is still in use. */
	323	static int nfnl_acct_try_del(struct nf_acct *cur)
	324	{
	325	int ret = 0;
	326
12be15dd LZ	327	/* We want to avoid races with nfnl_acct_put. So only when the current
	328	* refcnt is 1, we decrease it to 0.
	329	*/
b54ab92b	330	if (refcount_dec_if_one(&cur->refcnt)) {
94139027 PNA	331	/* We are protected by nfnl mutex. */
	332	list_del_rcu(&cur->head);
	333	kfree_rcu(cur, rcu_head);
	334	} else {
94139027 PNA	335	ret = -EBUSY;
	336	}
	337	return ret;
	338	}
	339
7b8002a1 PNA	340	static int nfnl_acct_del(struct net net, struct sock nfnl,
7b8002a1 PNA	341	struct sk_buff skb, const struct nlmsghdr nlh,
04ba724b PNA	342	const struct nlattr * const tb[],
04ba724b PNA	343	struct netlink_ext_ack *extack)
94139027	344	{
93fac10b	345	struct nf_acct cur, tmp;
94139027	346	int ret = -ENOENT;
93fac10b	347	char *acct_name;
94139027 PNA	348
94139027 PNA	349	if (!tb[NFACCT_NAME]) {
93fac10b	350	list_for_each_entry_safe(cur, tmp, &net->nfnl_acct_list, head)
94139027 PNA	351	nfnl_acct_try_del(cur);
	352
	353	return 0;
	354	}
	355	acct_name = nla_data(tb[NFACCT_NAME]);
	356
3499abb2	357	list_for_each_entry(cur, &net->nfnl_acct_list, head) {
94139027 PNA	358	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
	359	continue;
	360
	361	ret = nfnl_acct_try_del(cur);
	362	if (ret < 0)
	363	return ret;
	364
	365	break;
	366	}
	367	return ret;
	368	}
	369
	370	static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
	371	[NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
	372	[NFACCT_BYTES] = { .type = NLA_U64 },
	373	[NFACCT_PKTS] = { .type = NLA_U64 },
683399ed MP	374	[NFACCT_FLAGS] = { .type = NLA_U32 },
683399ed MP	375	[NFACCT_QUOTA] = { .type = NLA_U64 },
f111f780	376	[NFACCT_FILTER] = {.type = NLA_NESTED },
94139027 PNA	377	};
	378
	379	static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
	380	[NFNL_MSG_ACCT_NEW] = { .call = nfnl_acct_new,
	381	.attr_count = NFACCT_MAX,
	382	.policy = nfnl_acct_policy },
	383	[NFNL_MSG_ACCT_GET] = { .call = nfnl_acct_get,
	384	.attr_count = NFACCT_MAX,
	385	.policy = nfnl_acct_policy },
	386	[NFNL_MSG_ACCT_GET_CTRZERO] = { .call = nfnl_acct_get,
	387	.attr_count = NFACCT_MAX,
	388	.policy = nfnl_acct_policy },
	389	[NFNL_MSG_ACCT_DEL] = { .call = nfnl_acct_del,
	390	.attr_count = NFACCT_MAX,
	391	.policy = nfnl_acct_policy },
	392	};
	393
	394	static const struct nfnetlink_subsystem nfnl_acct_subsys = {
	395	.name = "acct",
	396	.subsys_id = NFNL_SUBSYS_ACCT,
	397	.cb_count = NFNL_MSG_ACCT_MAX,
	398	.cb = nfnl_acct_cb,
	399	};
	400
	401	MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
	402
3499abb2	403	struct nf_acct nfnl_acct_find_get(struct net net, const char *acct_name)
94139027 PNA	404	{
	405	struct nf_acct cur, acct = NULL;
	406
	407	rcu_read_lock();
3499abb2	408	list_for_each_entry_rcu(cur, &net->nfnl_acct_list, head) {
94139027 PNA	409	if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
	410	continue;
	411
	412	if (!try_module_get(THIS_MODULE))
	413	goto err;
	414
b54ab92b	415	if (!refcount_inc_not_zero(&cur->refcnt)) {
94139027 PNA	416	module_put(THIS_MODULE);
	417	goto err;
	418	}
	419
	420	acct = cur;
	421	break;
	422	}
	423	err:
	424	rcu_read_unlock();
	425	return acct;
	426	}
	427	EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
	428
	429	void nfnl_acct_put(struct nf_acct *acct)
	430	{
b54ab92b	431	if (refcount_dec_and_test(&acct->refcnt))
3499abb2 AS	432	kfree_rcu(acct, rcu_head);
3499abb2 AS	433
94139027 PNA	434	module_put(THIS_MODULE);
	435	}
	436	EXPORT_SYMBOL_GPL(nfnl_acct_put);
	437
	438	void nfnl_acct_update(const struct sk_buff skb, struct nf_acct nfacct)
	439	{
	440	atomic64_inc(&nfacct->pkts);
	441	atomic64_add(skb->len, &nfacct->bytes);
	442	}
	443	EXPORT_SYMBOL_GPL(nfnl_acct_update);
	444
aca30018	445	static void nfnl_overquota_report(struct net net, struct nf_acct nfacct)
683399ed MP	446	{
	447	int ret;
	448	struct sk_buff *skb;
	449
	450	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
	451	if (skb == NULL)
	452	return;
	453
	454	ret = nfnl_acct_fill_info(skb, 0, 0, NFNL_MSG_ACCT_OVERQUOTA, 0,
	455	nfacct);
	456	if (ret <= 0) {
	457	kfree_skb(skb);
	458	return;
	459	}
aca30018	460	netlink_broadcast(net->nfnl, skb, 0, NFNLGRP_ACCT_QUOTA,
683399ed MP	461	GFP_ATOMIC);
	462	}
	463
cceae76e	464	int nfnl_acct_overquota(struct net net, struct nf_acct nfacct)
683399ed MP	465	{
	466	u64 now;
	467	u64 *quota;
	468	int ret = NFACCT_UNDERQUOTA;
	469
	470	/* no place here if we don't have a quota */
	471	if (!(nfacct->flags & NFACCT_F_QUOTA))
	472	return NFACCT_NO_QUOTA;
	473
	474	quota = (u64 *)nfacct->data;
	475	now = (nfacct->flags & NFACCT_F_QUOTA_PKTS) ?
	476	atomic64_read(&nfacct->pkts) : atomic64_read(&nfacct->bytes);
	477
	478	ret = now > *quota;
	479
	480	if (now >= *quota &&
b6d04688	481	!test_and_set_bit(NFACCT_OVERQUOTA_BIT, &nfacct->flags)) {
aca30018	482	nfnl_overquota_report(net, nfacct);
683399ed MP	483	}
	484
	485	return ret;
	486	}
	487	EXPORT_SYMBOL_GPL(nfnl_acct_overquota);
	488
3499abb2 AS	489	static int __net_init nfnl_acct_net_init(struct net *net)
	490	{
	491	INIT_LIST_HEAD(&net->nfnl_acct_list);
	492
	493	return 0;
	494	}
	495
	496	static void __net_exit nfnl_acct_net_exit(struct net *net)
	497	{
	498	struct nf_acct cur, tmp;
	499
	500	list_for_each_entry_safe(cur, tmp, &net->nfnl_acct_list, head) {
	501	list_del_rcu(&cur->head);
	502
b54ab92b	503	if (refcount_dec_and_test(&cur->refcnt))
3499abb2 AS	504	kfree_rcu(cur, rcu_head);
	505	}
	506	}
	507
	508	static struct pernet_operations nfnl_acct_ops = {
	509	.init = nfnl_acct_net_init,
	510	.exit = nfnl_acct_net_exit,
	511	};
	512
94139027 PNA	513	static int __init nfnl_acct_init(void)
	514	{
	515	int ret;
	516
3499abb2 AS	517	ret = register_pernet_subsys(&nfnl_acct_ops);
	518	if (ret < 0) {
	519	pr_err("nfnl_acct_init: failed to register pernet ops\n");
	520	goto err_out;
	521	}
	522
94139027 PNA	523	ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
	524	if (ret < 0) {
	525	pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
3499abb2	526	goto cleanup_pernet;
94139027 PNA	527	}
94139027 PNA	528	return 0;
3499abb2 AS	529
	530	cleanup_pernet:
	531	unregister_pernet_subsys(&nfnl_acct_ops);
94139027 PNA	532	err_out:
	533	return ret;
	534	}
	535
	536	static void __exit nfnl_acct_exit(void)
	537	{
94139027	538	nfnetlink_subsys_unregister(&nfnl_acct_subsys);
3499abb2	539	unregister_pernet_subsys(&nfnl_acct_ops);
94139027 PNA	540	}
	541
	542	module_init(nfnl_acct_init);
	543	module_exit(nfnl_acct_exit);