[linux-block.git] / net / netfilter / nft_last.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_tables.h>

struct nft_last {
	unsigned long	jiffies;
	unsigned int	set;
};

struct nft_last_priv {
	struct nft_last	*last;
};

static const struct nla_policy nft_last_policy[NFTA_LAST_MAX + 1] = {
	[NFTA_LAST_SET] = { .type = NLA_U32 },
	[NFTA_LAST_MSECS] = { .type = NLA_U64 },
};

static int nft_last_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
			 const struct nlattr * const tb[])
{
	struct nft_last_priv *priv = nft_expr_priv(expr);
	struct nft_last *last;
	u64 last_jiffies;
	int err;

	last = kzalloc(sizeof(*last), GFP_KERNEL_ACCOUNT);
	if (!last)
		return -ENOMEM;

	if (tb[NFTA_LAST_SET])
		last->set = ntohl(nla_get_be32(tb[NFTA_LAST_SET]));

	if (last->set && tb[NFTA_LAST_MSECS]) {
		err = nf_msecs_to_jiffies64(tb[NFTA_LAST_MSECS], &last_jiffies);
		if (err < 0)
			goto err;

		last->jiffies = jiffies - (unsigned long)last_jiffies;
	}
	priv->last = last;

	return 0;
err:
	kfree(last);

	return err;
}

static void nft_last_eval(const struct nft_expr *expr,
			  struct nft_regs *regs, const struct nft_pktinfo *pkt)
{
	struct nft_last_priv *priv = nft_expr_priv(expr);
	struct nft_last *last = priv->last;

	if (READ_ONCE(last->jiffies) != jiffies)
		WRITE_ONCE(last->jiffies, jiffies);
	if (READ_ONCE(last->set) == 0)
		WRITE_ONCE(last->set, 1);
}

static int nft_last_dump(struct sk_buff *skb,
			 const struct nft_expr *expr, bool reset)
{
	struct nft_last_priv *priv = nft_expr_priv(expr);
	struct nft_last *last = priv->last;
	unsigned long last_jiffies = READ_ONCE(last->jiffies);
	u32 last_set = READ_ONCE(last->set);
	__be64 msecs;

	if (time_before(jiffies, last_jiffies)) {
		WRITE_ONCE(last->set, 0);
		last_set = 0;
	}

	if (last_set)
		msecs = nf_jiffies64_to_msecs(jiffies - last_jiffies);
	else
		msecs = 0;

	if (nla_put_be32(skb, NFTA_LAST_SET, htonl(last_set)) ||
	    nla_put_be64(skb, NFTA_LAST_MSECS, msecs, NFTA_LAST_PAD))
		goto nla_put_failure;

	return 0;

nla_put_failure:
	return -1;
}

static void nft_last_destroy(const struct nft_ctx *ctx,
			     const struct nft_expr *expr)
{
	struct nft_last_priv *priv = nft_expr_priv(expr);

	kfree(priv->last);
}

static int nft_last_clone(struct nft_expr *dst, const struct nft_expr *src)
{
	struct nft_last_priv *priv_dst = nft_expr_priv(dst);
	struct nft_last_priv *priv_src = nft_expr_priv(src);

	priv_dst->last = kzalloc(sizeof(*priv_dst->last), GFP_ATOMIC);
	if (!priv_dst->last)
		return -ENOMEM;

	priv_dst->last->set = priv_src->last->set;
	priv_dst->last->jiffies = priv_src->last->jiffies;

	return 0;
}

static const struct nft_expr_ops nft_last_ops = {
	.type		= &nft_last_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_last_priv)),
	.eval		= nft_last_eval,
	.init		= nft_last_init,
	.destroy	= nft_last_destroy,
	.clone		= nft_last_clone,
	.dump		= nft_last_dump,
	.reduce		= NFT_REDUCE_READONLY,
};

struct nft_expr_type nft_last_type __read_mostly = {
	.name		= "last",
	.ops		= &nft_last_ops,
	.policy		= nft_last_policy,
	.maxattr	= NFTA_LAST_MAX,
	.flags		= NFT_EXPR_STATEFUL,
	.owner		= THIS_MODULE,
};
Commit	Line	Data
836382dc PNA	1	// SPDX-License-Identifier: GPL-2.0-only
	2	#include <linux/kernel.h>
	3	#include <linux/init.h>
	4	#include <linux/module.h>
	5	#include <linux/netlink.h>
	6	#include <linux/netfilter.h>
	7	#include <linux/netfilter/nf_tables.h>
	8	#include <net/netfilter/nf_tables_core.h>
	9	#include <net/netfilter/nf_tables.h>
	10
33a24de3 PNA	11	struct nft_last {
	12	unsigned long jiffies;
	13	unsigned int set;
	14	};
	15
836382dc	16	struct nft_last_priv {
33a24de3	17	struct nft_last *last;
836382dc PNA	18	};
	19
	20	static const struct nla_policy nft_last_policy[NFTA_LAST_MAX + 1] = {
	21	[NFTA_LAST_SET] = { .type = NLA_U32 },
	22	[NFTA_LAST_MSECS] = { .type = NLA_U64 },
	23	};
	24
	25	static int nft_last_init(const struct nft_ctx ctx, const struct nft_expr expr,
	26	const struct nlattr * const tb[])
	27	{
	28	struct nft_last_priv *priv = nft_expr_priv(expr);
33a24de3	29	struct nft_last *last;
836382dc PNA	30	u64 last_jiffies;
	31	int err;
	32
42193ffd	33	last = kzalloc(sizeof(*last), GFP_KERNEL_ACCOUNT);
33a24de3 PNA	34	if (!last)
	35	return -ENOMEM;
	36
	37	if (tb[NFTA_LAST_SET])
	38	last->set = ntohl(nla_get_be32(tb[NFTA_LAST_SET]));
6ac4bac4	39
33a24de3	40	if (last->set && tb[NFTA_LAST_MSECS]) {
836382dc PNA	41	err = nf_msecs_to_jiffies64(tb[NFTA_LAST_MSECS], &last_jiffies);
836382dc PNA	42	if (err < 0)
33a24de3	43	goto err;
836382dc	44
33a24de3	45	last->jiffies = jiffies - (unsigned long)last_jiffies;
836382dc	46	}
33a24de3	47	priv->last = last;
836382dc PNA	48
836382dc PNA	49	return 0;
33a24de3 PNA	50	err:
	51	kfree(last);
	52
	53	return err;
836382dc PNA	54	}
	55
	56	static void nft_last_eval(const struct nft_expr *expr,
	57	struct nft_regs regs, const struct nft_pktinfo pkt)
	58	{
	59	struct nft_last_priv *priv = nft_expr_priv(expr);
33a24de3	60	struct nft_last *last = priv->last;
836382dc	61
33a24de3 PNA	62	if (READ_ONCE(last->jiffies) != jiffies)
	63	WRITE_ONCE(last->jiffies, jiffies);
	64	if (READ_ONCE(last->set) == 0)
	65	WRITE_ONCE(last->set, 1);
836382dc PNA	66	}
836382dc PNA	67
7d34aa3e PS	68	static int nft_last_dump(struct sk_buff *skb,
7d34aa3e PS	69	const struct nft_expr *expr, bool reset)
836382dc PNA	70	{
836382dc PNA	71	struct nft_last_priv *priv = nft_expr_priv(expr);
33a24de3 PNA	72	struct nft_last *last = priv->last;
	73	unsigned long last_jiffies = READ_ONCE(last->jiffies);
	74	u32 last_set = READ_ONCE(last->set);
836382dc PNA	75	__be64 msecs;
836382dc PNA	76
32953df7	77	if (time_before(jiffies, last_jiffies)) {
33a24de3	78	WRITE_ONCE(last->set, 0);
32953df7 PNA	79	last_set = 0;
32953df7 PNA	80	}
836382dc	81
32953df7 PNA	82	if (last_set)
32953df7 PNA	83	msecs = nf_jiffies64_to_msecs(jiffies - last_jiffies);
836382dc PNA	84	else
	85	msecs = 0;
	86
32953df7	87	if (nla_put_be32(skb, NFTA_LAST_SET, htonl(last_set)) \|\|
836382dc PNA	88	nla_put_be64(skb, NFTA_LAST_MSECS, msecs, NFTA_LAST_PAD))
	89	goto nla_put_failure;
	90
	91	return 0;
	92
	93	nla_put_failure:
	94	return -1;
	95	}
	96
33a24de3 PNA	97	static void nft_last_destroy(const struct nft_ctx *ctx,
	98	const struct nft_expr *expr)
	99	{
	100	struct nft_last_priv *priv = nft_expr_priv(expr);
	101
	102	kfree(priv->last);
	103	}
	104
	105	static int nft_last_clone(struct nft_expr dst, const struct nft_expr src)
	106	{
	107	struct nft_last_priv *priv_dst = nft_expr_priv(dst);
860e8742	108	struct nft_last_priv *priv_src = nft_expr_priv(src);
33a24de3 PNA	109
33a24de3 PNA	110	priv_dst->last = kzalloc(sizeof(*priv_dst->last), GFP_ATOMIC);
51edb2ff	111	if (!priv_dst->last)
33a24de3 PNA	112	return -ENOMEM;
33a24de3 PNA	113
860e8742 PNA	114	priv_dst->last->set = priv_src->last->set;
	115	priv_dst->last->jiffies = priv_src->last->jiffies;
	116
33a24de3 PNA	117	return 0;
	118	}
	119
836382dc PNA	120	static const struct nft_expr_ops nft_last_ops = {
	121	.type = &nft_last_type,
	122	.size = NFT_EXPR_SIZE(sizeof(struct nft_last_priv)),
	123	.eval = nft_last_eval,
	124	.init = nft_last_init,
33a24de3 PNA	125	.destroy = nft_last_destroy,
33a24de3 PNA	126	.clone = nft_last_clone,
836382dc	127	.dump = nft_last_dump,
b2d30654	128	.reduce = NFT_REDUCE_READONLY,
836382dc PNA	129	};
	130
	131	struct nft_expr_type nft_last_type __read_mostly = {
	132	.name = "last",
	133	.ops = &nft_last_ops,
	134	.policy = nft_last_policy,
	135	.maxattr = NFTA_LAST_MAX,
	136	.flags = NFT_EXPR_STATEFUL,
	137	.owner = THIS_MODULE,
	138	};