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

/*
 * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
 *
 * 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.
 */

#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->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 __read_mostly = {
	.type		= NFT_OBJECT_QUOTA,
	.size		= sizeof(struct nft_quota),
	.maxattr	= NFTA_QUOTA_MAX,
	.policy		= nft_quota_policy,
	.init		= nft_quota_obj_init,
	.eval		= nft_quota_obj_eval,
	.dump		= nft_quota_obj_dump,
	.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);
	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);
	return err;
}

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

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