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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/atomic.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>

struct nft_quota {
	u64		quota;
	unsigned long	flags;
	atomic64_t	consumed;
};

static inline bool nft_overquota(struct nft_quota *priv,
				 const struct sk_buff *skb)
{
	return atomic64_add_return(skb->len, &priv->consumed) >= priv->quota;
}

static inline bool nft_quota_invert(struct nft_quota *priv)
{
	return priv->flags & NFT_QUOTA_F_INV;
}

static inline void nft_quota_do_eval(struct nft_quota *priv,
				     struct nft_regs *regs,
				     const struct nft_pktinfo *pkt)
{
	if (nft_overquota(priv, pkt->skb) ^ nft_quota_invert(priv))
		regs->verdict.code = NFT_BREAK;
}

static const struct nla_policy nft_quota_policy[NFTA_QUOTA_MAX + 1] = {
	[NFTA_QUOTA_BYTES]	= { .type = NLA_U64 },
	[NFTA_QUOTA_FLAGS]	= { .type = NLA_U32 },
	[NFTA_QUOTA_CONSUMED]	= { .type = NLA_U64 },
};

#define NFT_QUOTA_DEPLETED_BIT	1	/* From NFT_QUOTA_F_DEPLETED. */

static void nft_quota_obj_eval(struct nft_object *obj,
			       struct nft_regs *regs,
			       const struct nft_pktinfo *pkt)
{
	struct nft_quota *priv = nft_obj_data(obj);
	bool overquota;

	overquota = nft_overquota(priv, pkt->skb);
	if (overquota ^ nft_quota_invert(priv))
		regs->verdict.code = NFT_BREAK;

	if (overquota &&
	    !test_and_set_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags))
		nft_obj_notify(nft_net(pkt), obj->key.table, obj, 0, 0,
			       NFT_MSG_NEWOBJ, nft_pf(pkt), 0, GFP_ATOMIC);
}

static int nft_quota_do_init(const struct nlattr * const tb[],
			     struct nft_quota *priv)
{
	unsigned long flags = 0;
	u64 quota, consumed = 0;

	if (!tb[NFTA_QUOTA_BYTES])
		return -EINVAL;

	quota = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_BYTES]));
	if (quota > S64_MAX)
		return -EOVERFLOW;

	if (tb[NFTA_QUOTA_CONSUMED]) {
		consumed = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_CONSUMED]));
		if (consumed > quota)
			return -EINVAL;
	}

	if (tb[NFTA_QUOTA_FLAGS]) {
		flags = ntohl(nla_get_be32(tb[NFTA_QUOTA_FLAGS]));
		if (flags & ~NFT_QUOTA_F_INV)
			return -EINVAL;
		if (flags & NFT_QUOTA_F_DEPLETED)
			return -EOPNOTSUPP;
	}

	priv->quota = quota;
	priv->flags = flags;
	atomic64_set(&priv->consumed, consumed);

	return 0;
}

static int nft_quota_obj_init(const struct nft_ctx *ctx,
			      const struct nlattr * const tb[],
			      struct nft_object *obj)
{
	struct nft_quota *priv = nft_obj_data(obj);

	return nft_quota_do_init(tb, priv);
}

static int nft_quota_do_dump(struct sk_buff *skb, struct nft_quota *priv,
			     bool reset)
{
	u64 consumed, consumed_cap;
	u32 flags = priv->flags;

	/* Since we inconditionally increment consumed quota for each packet
	 * that we see, don't go over the quota boundary in what we send to
	 * userspace.
	 */
	consumed = atomic64_read(&priv->consumed);
	if (consumed >= priv->quota) {
		consumed_cap = priv->quota;
		flags |= NFT_QUOTA_F_DEPLETED;
	} else {
		consumed_cap = consumed;
	}

	if (nla_put_be64(skb, NFTA_QUOTA_BYTES, cpu_to_be64(priv->quota),
			 NFTA_QUOTA_PAD) ||
	    nla_put_be64(skb, NFTA_QUOTA_CONSUMED, cpu_to_be64(consumed_cap),
			 NFTA_QUOTA_PAD) ||
	    nla_put_be32(skb, NFTA_QUOTA_FLAGS, htonl(flags)))
		goto nla_put_failure;

	if (reset) {
		atomic64_sub(consumed, &priv->consumed);
		clear_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags);
	}
	return 0;

nla_put_failure:
	return -1;
}

static int nft_quota_obj_dump(struct sk_buff *skb, struct nft_object *obj,
			      bool reset)
{
	struct nft_quota *priv = nft_obj_data(obj);

	return nft_quota_do_dump(skb, priv, reset);
}

static struct nft_object_type nft_quota_obj_type;
static const struct nft_object_ops nft_quota_obj_ops = {
	.type		= &nft_quota_obj_type,
	.size		= sizeof(struct nft_quota),
	.init		= nft_quota_obj_init,
	.eval		= nft_quota_obj_eval,
	.dump		= nft_quota_obj_dump,
};

static struct nft_object_type nft_quota_obj_type __read_mostly = {
	.type		= NFT_OBJECT_QUOTA,
	.ops		= &nft_quota_obj_ops,
	.maxattr	= NFTA_QUOTA_MAX,
	.policy		= nft_quota_policy,
	.owner		= THIS_MODULE,
};

static void nft_quota_eval(const struct nft_expr *expr,
			   struct nft_regs *regs,
			   const struct nft_pktinfo *pkt)
{
	struct nft_quota *priv = nft_expr_priv(expr);

	nft_quota_do_eval(priv, regs, pkt);
}

static int nft_quota_init(const struct nft_ctx *ctx,
			  const struct nft_expr *expr,
			  const struct nlattr * const tb[])
{
	struct nft_quota *priv = nft_expr_priv(expr);

	return nft_quota_do_init(tb, priv);
}

static int nft_quota_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
	struct nft_quota *priv = nft_expr_priv(expr);

	return nft_quota_do_dump(skb, priv, false);
}

static struct nft_expr_type nft_quota_type;
static const struct nft_expr_ops nft_quota_ops = {
	.type		= &nft_quota_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_quota)),
	.eval		= nft_quota_eval,
	.init		= nft_quota_init,
	.dump		= nft_quota_dump,
};

static struct nft_expr_type nft_quota_type __read_mostly = {
	.name		= "quota",
	.ops		= &nft_quota_ops,
	.policy		= nft_quota_policy,
	.maxattr	= NFTA_QUOTA_MAX,
	.flags		= NFT_EXPR_STATEFUL,
	.owner		= THIS_MODULE,
};

static int __init nft_quota_module_init(void)
{
	int err;

	err = nft_register_obj(&nft_quota_obj_type);
	if (err < 0)
		return err;

	err = nft_register_expr(&nft_quota_type);
	if (err < 0)
		goto err1;

	return 0;
err1:
	nft_unregister_obj(&nft_quota_obj_type);
	return err;
}

static void __exit nft_quota_module_exit(void)
{
	nft_unregister_expr(&nft_quota_type);
	nft_unregister_obj(&nft_quota_obj_type);
}

module_init(nft_quota_module_init);
module_exit(nft_quota_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
MODULE_ALIAS_NFT_EXPR("quota");
MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_QUOTA);
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
3d2f30a1 PNA	2	/*
3d2f30a1 PNA	3	* Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
3d2f30a1 PNA	4	*/
	5
	6	#include <linux/kernel.h>
	7	#include <linux/init.h>
	8	#include <linux/module.h>
	9	#include <linux/atomic.h>
	10	#include <linux/netlink.h>
	11	#include <linux/netfilter.h>
	12	#include <linux/netfilter/nf_tables.h>
	13	#include <net/netfilter/nf_tables.h>
	14
	15	struct nft_quota {
	16	u64 quota;
18965317	17	unsigned long flags;
795595f6	18	atomic64_t consumed;
3d2f30a1 PNA	19	};
3d2f30a1 PNA	20
22609b43	21	static inline bool nft_overquota(struct nft_quota *priv,
795595f6	22	const struct sk_buff *skb)
3d2f30a1	23	{
795595f6	24	return atomic64_add_return(skb->len, &priv->consumed) >= priv->quota;
3d2f30a1 PNA	25	}
3d2f30a1 PNA	26
18965317 PNA	27	static inline bool nft_quota_invert(struct nft_quota *priv)
	28	{
	29	return priv->flags & NFT_QUOTA_F_INV;
	30	}
	31
173705d9 PNA	32	static inline void nft_quota_do_eval(struct nft_quota *priv,
	33	struct nft_regs *regs,
	34	const struct nft_pktinfo *pkt)
3d2f30a1	35	{
18965317	36	if (nft_overquota(priv, pkt->skb) ^ nft_quota_invert(priv))
3d2f30a1 PNA	37	regs->verdict.code = NFT_BREAK;
	38	}
	39
	40	static const struct nla_policy nft_quota_policy[NFTA_QUOTA_MAX + 1] = {
	41	[NFTA_QUOTA_BYTES] = { .type = NLA_U64 },
	42	[NFTA_QUOTA_FLAGS] = { .type = NLA_U32 },
73c25fb1	43	[NFTA_QUOTA_CONSUMED] = { .type = NLA_U64 },
3d2f30a1 PNA	44	};
3d2f30a1 PNA	45
18965317 PNA	46	#define NFT_QUOTA_DEPLETED_BIT 1 /* From NFT_QUOTA_F_DEPLETED. */
18965317 PNA	47
173705d9 PNA	48	static void nft_quota_obj_eval(struct nft_object *obj,
	49	struct nft_regs *regs,
	50	const struct nft_pktinfo *pkt)
	51	{
	52	struct nft_quota *priv = nft_obj_data(obj);
18965317	53	bool overquota;
173705d9	54
18965317 PNA	55	overquota = nft_overquota(priv, pkt->skb);
	56	if (overquota ^ nft_quota_invert(priv))
	57	regs->verdict.code = NFT_BREAK;
	58
	59	if (overquota &&
	60	!test_and_set_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags))
d152159b	61	nft_obj_notify(nft_net(pkt), obj->key.table, obj, 0, 0,
18965317	62	NFT_MSG_NEWOBJ, nft_pf(pkt), 0, GFP_ATOMIC);
173705d9 PNA	63	}
	64
	65	static int nft_quota_do_init(const struct nlattr * const tb[],
	66	struct nft_quota *priv)
3d2f30a1	67	{
18965317	68	unsigned long flags = 0;
73c25fb1	69	u64 quota, consumed = 0;
3d2f30a1 PNA	70
	71	if (!tb[NFTA_QUOTA_BYTES])
	72	return -EINVAL;
	73
	74	quota = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_BYTES]));
	75	if (quota > S64_MAX)
	76	return -EOVERFLOW;
	77
73c25fb1 PNA	78	if (tb[NFTA_QUOTA_CONSUMED]) {
	79	consumed = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_CONSUMED]));
	80	if (consumed > quota)
	81	return -EINVAL;
	82	}
	83
3d2f30a1 PNA	84	if (tb[NFTA_QUOTA_FLAGS]) {
	85	flags = ntohl(nla_get_be32(tb[NFTA_QUOTA_FLAGS]));
	86	if (flags & ~NFT_QUOTA_F_INV)
	87	return -EINVAL;
18965317 PNA	88	if (flags & NFT_QUOTA_F_DEPLETED)
18965317 PNA	89	return -EOPNOTSUPP;
3d2f30a1 PNA	90	}
	91
	92	priv->quota = quota;
18965317	93	priv->flags = flags;
73c25fb1	94	atomic64_set(&priv->consumed, consumed);
3d2f30a1 PNA	95
	96	return 0;
	97	}
	98
84fba055 FW	99	static int nft_quota_obj_init(const struct nft_ctx *ctx,
84fba055 FW	100	const struct nlattr * const tb[],
173705d9 PNA	101	struct nft_object *obj)
	102	{
	103	struct nft_quota *priv = nft_obj_data(obj);
	104
	105	return nft_quota_do_init(tb, priv);
	106	}
	107
43da04a5 PNA	108	static int nft_quota_do_dump(struct sk_buff skb, struct nft_quota priv,
43da04a5 PNA	109	bool reset)
3d2f30a1	110	{
8010d7fe	111	u64 consumed, consumed_cap;
18965317	112	u32 flags = priv->flags;
43da04a5	113
795595f6 PNA	114	/* Since we inconditionally increment consumed quota for each packet
	115	* that we see, don't go over the quota boundary in what we send to
	116	* userspace.
	117	*/
8010d7fe PNA	118	consumed = atomic64_read(&priv->consumed);
	119	if (consumed >= priv->quota) {
	120	consumed_cap = priv->quota;
	121	flags \|= NFT_QUOTA_F_DEPLETED;
	122	} else {
	123	consumed_cap = consumed;
	124	}
3d2f30a1 PNA	125
	126	if (nla_put_be64(skb, NFTA_QUOTA_BYTES, cpu_to_be64(priv->quota),
	127	NFTA_QUOTA_PAD) \|\|
8010d7fe	128	nla_put_be64(skb, NFTA_QUOTA_CONSUMED, cpu_to_be64(consumed_cap),
795595f6	129	NFTA_QUOTA_PAD) \|\|
3d2f30a1 PNA	130	nla_put_be32(skb, NFTA_QUOTA_FLAGS, htonl(flags)))
3d2f30a1 PNA	131	goto nla_put_failure;
8010d7fe PNA	132
	133	if (reset) {
	134	atomic64_sub(consumed, &priv->consumed);
	135	clear_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags);
	136	}
3d2f30a1 PNA	137	return 0;
	138
	139	nla_put_failure:
	140	return -1;
	141	}
	142
43da04a5 PNA	143	static int nft_quota_obj_dump(struct sk_buff skb, struct nft_object obj,
43da04a5 PNA	144	bool reset)
173705d9 PNA	145	{
	146	struct nft_quota *priv = nft_obj_data(obj);
	147
43da04a5	148	return nft_quota_do_dump(skb, priv, reset);
173705d9 PNA	149	}
173705d9 PNA	150
dfc46034 PBG	151	static struct nft_object_type nft_quota_obj_type;
	152	static const struct nft_object_ops nft_quota_obj_ops = {
	153	.type = &nft_quota_obj_type,
173705d9	154	.size = sizeof(struct nft_quota),
173705d9 PNA	155	.init = nft_quota_obj_init,
	156	.eval = nft_quota_obj_eval,
	157	.dump = nft_quota_obj_dump,
dfc46034 PBG	158	};
	159
	160	static struct nft_object_type nft_quota_obj_type __read_mostly = {
	161	.type = NFT_OBJECT_QUOTA,
	162	.ops = &nft_quota_obj_ops,
	163	.maxattr = NFTA_QUOTA_MAX,
	164	.policy = nft_quota_policy,
173705d9 PNA	165	.owner = THIS_MODULE,
	166	};
	167
	168	static void nft_quota_eval(const struct nft_expr *expr,
	169	struct nft_regs *regs,
	170	const struct nft_pktinfo *pkt)
	171	{
	172	struct nft_quota *priv = nft_expr_priv(expr);
	173
	174	nft_quota_do_eval(priv, regs, pkt);
	175	}
	176
	177	static int nft_quota_init(const struct nft_ctx *ctx,
	178	const struct nft_expr *expr,
	179	const struct nlattr * const tb[])
	180	{
	181	struct nft_quota *priv = nft_expr_priv(expr);
	182
	183	return nft_quota_do_init(tb, priv);
	184	}
	185
	186	static int nft_quota_dump(struct sk_buff skb, const struct nft_expr expr)
	187	{
43da04a5	188	struct nft_quota *priv = nft_expr_priv(expr);
173705d9	189
43da04a5	190	return nft_quota_do_dump(skb, priv, false);
173705d9 PNA	191	}
173705d9 PNA	192
3d2f30a1 PNA	193	static struct nft_expr_type nft_quota_type;
	194	static const struct nft_expr_ops nft_quota_ops = {
	195	.type = &nft_quota_type,
	196	.size = NFT_EXPR_SIZE(sizeof(struct nft_quota)),
	197	.eval = nft_quota_eval,
	198	.init = nft_quota_init,
	199	.dump = nft_quota_dump,
	200	};
	201
	202	static struct nft_expr_type nft_quota_type __read_mostly = {
	203	.name = "quota",
	204	.ops = &nft_quota_ops,
	205	.policy = nft_quota_policy,
	206	.maxattr = NFTA_QUOTA_MAX,
	207	.flags = NFT_EXPR_STATEFUL,
	208	.owner = THIS_MODULE,
	209	};
	210
	211	static int __init nft_quota_module_init(void)
	212	{
173705d9 PNA	213	int err;
173705d9 PNA	214
dfc46034	215	err = nft_register_obj(&nft_quota_obj_type);
173705d9 PNA	216	if (err < 0)
	217	return err;
	218
	219	err = nft_register_expr(&nft_quota_type);
	220	if (err < 0)
	221	goto err1;
	222
	223	return 0;
	224	err1:
dfc46034	225	nft_unregister_obj(&nft_quota_obj_type);
173705d9	226	return err;
3d2f30a1 PNA	227	}
	228
	229	static void __exit nft_quota_module_exit(void)
	230	{
173705d9	231	nft_unregister_expr(&nft_quota_type);
dfc46034	232	nft_unregister_obj(&nft_quota_obj_type);
3d2f30a1 PNA	233	}
	234
	235	module_init(nft_quota_module_init);
	236	module_exit(nft_quota_module_exit);
	237
	238	MODULE_LICENSE("GPL");
	239	MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
	240	MODULE_ALIAS_NFT_EXPR("quota");
173705d9	241	MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_QUOTA);