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

/*
 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
 *
 * 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.
 *
 * Development of this code funded by Astaro AG (http://www.astaro.com/)
 */

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

struct nft_limit {
	spinlock_t	lock;
	u64		last;
	u64		tokens;
	u64		tokens_max;
	u64		rate;
	u64		nsecs;
	u32		burst;
	bool		invert;
};

static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost)
{
	u64 now, tokens;
	s64 delta;

	spin_lock_bh(&limit->lock);
	now = ktime_get_ns();
	tokens = limit->tokens + now - limit->last;
	if (tokens > limit->tokens_max)
		tokens = limit->tokens_max;

	limit->last = now;
	delta = tokens - cost;
	if (delta >= 0) {
		limit->tokens = delta;
		spin_unlock_bh(&limit->lock);
		return limit->invert;
	}
	limit->tokens = tokens;
	spin_unlock_bh(&limit->lock);
	return !limit->invert;
}

static int nft_limit_init(struct nft_limit *limit,
			  const struct nlattr * const tb[])
{
	u64 unit;

	if (tb[NFTA_LIMIT_RATE] == NULL ||
	    tb[NFTA_LIMIT_UNIT] == NULL)
		return -EINVAL;

	limit->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE]));
	unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT]));
	limit->nsecs = unit * NSEC_PER_SEC;
	if (limit->rate == 0 || limit->nsecs < unit)
		return -EOVERFLOW;
	limit->tokens = limit->tokens_max = limit->nsecs;

	if (tb[NFTA_LIMIT_BURST]) {
		u64 rate;

		limit->burst = ntohl(nla_get_be32(tb[NFTA_LIMIT_BURST]));

		rate = limit->rate + limit->burst;
		if (rate < limit->rate)
			return -EOVERFLOW;

		limit->rate = rate;
	}
	if (tb[NFTA_LIMIT_FLAGS]) {
		u32 flags = ntohl(nla_get_be32(tb[NFTA_LIMIT_FLAGS]));

		if (flags & NFT_LIMIT_F_INV)
			limit->invert = true;
	}
	limit->last = ktime_get_ns();
	spin_lock_init(&limit->lock);

	return 0;
}

static int nft_limit_dump(struct sk_buff *skb, const struct nft_limit *limit,
			  enum nft_limit_type type)
{
	u32 flags = limit->invert ? NFT_LIMIT_F_INV : 0;
	u64 secs = div_u64(limit->nsecs, NSEC_PER_SEC);
	u64 rate = limit->rate - limit->burst;

	if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(rate),
			 NFTA_LIMIT_PAD) ||
	    nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(secs),
			 NFTA_LIMIT_PAD) ||
	    nla_put_be32(skb, NFTA_LIMIT_BURST, htonl(limit->burst)) ||
	    nla_put_be32(skb, NFTA_LIMIT_TYPE, htonl(type)) ||
	    nla_put_be32(skb, NFTA_LIMIT_FLAGS, htonl(flags)))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -1;
}

struct nft_limit_pkts {
	struct nft_limit	limit;
	u64			cost;
};

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

	if (nft_limit_eval(&priv->limit, priv->cost))
		regs->verdict.code = NFT_BREAK;
}

static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = {
	[NFTA_LIMIT_RATE]	= { .type = NLA_U64 },
	[NFTA_LIMIT_UNIT]	= { .type = NLA_U64 },
	[NFTA_LIMIT_BURST]	= { .type = NLA_U32 },
	[NFTA_LIMIT_TYPE]	= { .type = NLA_U32 },
	[NFTA_LIMIT_FLAGS]	= { .type = NLA_U32 },
};

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

	err = nft_limit_init(&priv->limit, tb);
	if (err < 0)
		return err;

	priv->cost = div64_u64(priv->limit.nsecs, priv->limit.rate);
	return 0;
}

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

	return nft_limit_dump(skb, &priv->limit, NFT_LIMIT_PKTS);
}

static struct nft_expr_type nft_limit_type;
static const struct nft_expr_ops nft_limit_pkts_ops = {
	.type		= &nft_limit_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_limit_pkts)),
	.eval		= nft_limit_pkts_eval,
	.init		= nft_limit_pkts_init,
	.dump		= nft_limit_pkts_dump,
};

static void nft_limit_pkt_bytes_eval(const struct nft_expr *expr,
				     struct nft_regs *regs,
				     const struct nft_pktinfo *pkt)
{
	struct nft_limit *priv = nft_expr_priv(expr);
	u64 cost = div64_u64(priv->nsecs * pkt->skb->len, priv->rate);

	if (nft_limit_eval(priv, cost))
		regs->verdict.code = NFT_BREAK;
}

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

	return nft_limit_init(priv, tb);
}

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

	return nft_limit_dump(skb, priv, NFT_LIMIT_PKT_BYTES);
}

static const struct nft_expr_ops nft_limit_pkt_bytes_ops = {
	.type		= &nft_limit_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_limit)),
	.eval		= nft_limit_pkt_bytes_eval,
	.init		= nft_limit_pkt_bytes_init,
	.dump		= nft_limit_pkt_bytes_dump,
};

static const struct nft_expr_ops *
nft_limit_select_ops(const struct nft_ctx *ctx,
		     const struct nlattr * const tb[])
{
	if (tb[NFTA_LIMIT_TYPE] == NULL)
		return &nft_limit_pkts_ops;

	switch (ntohl(nla_get_be32(tb[NFTA_LIMIT_TYPE]))) {
	case NFT_LIMIT_PKTS:
		return &nft_limit_pkts_ops;
	case NFT_LIMIT_PKT_BYTES:
		return &nft_limit_pkt_bytes_ops;
	}
	return ERR_PTR(-EOPNOTSUPP);
}

static struct nft_expr_type nft_limit_type __read_mostly = {
	.name		= "limit",
	.select_ops	= nft_limit_select_ops,
	.policy		= nft_limit_policy,
	.maxattr	= NFTA_LIMIT_MAX,
	.flags		= NFT_EXPR_STATEFUL,
	.owner		= THIS_MODULE,
};

static int __init nft_limit_module_init(void)
{
	return nft_register_expr(&nft_limit_type);
}

static void __exit nft_limit_module_exit(void)
{
	nft_unregister_expr(&nft_limit_type);
}

module_init(nft_limit_module_init);
module_exit(nft_limit_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_EXPR("limit");
Commit	Line	Data
96518518	1	/*
ef1f7df9	2	* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
96518518 PM	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	* Development of this code funded by Astaro AG (http://www.astaro.com/)
	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/init.h>
	13	#include <linux/module.h>
	14	#include <linux/spinlock.h>
	15	#include <linux/netlink.h>
	16	#include <linux/netfilter.h>
	17	#include <linux/netfilter/nf_tables.h>
	18	#include <net/netfilter/nf_tables.h>
	19
96518518	20	struct nft_limit {
2cb4bbd7	21	spinlock_t lock;
dba27ec1	22	u64 last;
96518518	23	u64 tokens;
dba27ec1	24	u64 tokens_max;
96518518	25	u64 rate;
dba27ec1	26	u64 nsecs;
3e87baaf	27	u32 burst;
c7862a5f	28	bool invert;
96518518 PM	29	};
96518518 PM	30
f8d3a6bc	31	static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost)
96518518	32	{
f8d3a6bc	33	u64 now, tokens;
dba27ec1	34	s64 delta;
96518518	35
2cb4bbd7	36	spin_lock_bh(&limit->lock);
dba27ec1	37	now = ktime_get_ns();
f8d3a6bc PNA	38	tokens = limit->tokens + now - limit->last;
	39	if (tokens > limit->tokens_max)
	40	tokens = limit->tokens_max;
dba27ec1	41
f8d3a6bc	42	limit->last = now;
dba27ec1 PNA	43	delta = tokens - cost;
dba27ec1 PNA	44	if (delta >= 0) {
f8d3a6bc	45	limit->tokens = delta;
2cb4bbd7	46	spin_unlock_bh(&limit->lock);
c7862a5f	47	return limit->invert;
96518518	48	}
f8d3a6bc	49	limit->tokens = tokens;
2cb4bbd7	50	spin_unlock_bh(&limit->lock);
c7862a5f	51	return !limit->invert;
96518518 PM	52	}
96518518 PM	53
f8d3a6bc	54	static int nft_limit_init(struct nft_limit *limit,
96518518 PM	55	const struct nlattr * const tb[])
96518518 PM	56	{
dba27ec1	57	u64 unit;
96518518 PM	58
	59	if (tb[NFTA_LIMIT_RATE] == NULL \|\|
	60	tb[NFTA_LIMIT_UNIT] == NULL)
	61	return -EINVAL;
	62
f8d3a6bc	63	limit->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE]));
dba27ec1	64	unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT]));
f8d3a6bc PNA	65	limit->nsecs = unit * NSEC_PER_SEC;
f8d3a6bc PNA	66	if (limit->rate == 0 \|\| limit->nsecs < unit)
dba27ec1	67	return -EOVERFLOW;
f8d3a6bc	68	limit->tokens = limit->tokens_max = limit->nsecs;
3e87baaf PNA	69
	70	if (tb[NFTA_LIMIT_BURST]) {
	71	u64 rate;
	72
	73	limit->burst = ntohl(nla_get_be32(tb[NFTA_LIMIT_BURST]));
	74
	75	rate = limit->rate + limit->burst;
	76	if (rate < limit->rate)
	77	return -EOVERFLOW;
	78
	79	limit->rate = rate;
	80	}
c7862a5f PNA	81	if (tb[NFTA_LIMIT_FLAGS]) {
	82	u32 flags = ntohl(nla_get_be32(tb[NFTA_LIMIT_FLAGS]));
	83
	84	if (flags & NFT_LIMIT_F_INV)
	85	limit->invert = true;
	86	}
f8d3a6bc	87	limit->last = ktime_get_ns();
2cb4bbd7	88	spin_lock_init(&limit->lock);
f8d3a6bc	89
96518518 PM	90	return 0;
	91	}
	92
d2168e84 PNA	93	static int nft_limit_dump(struct sk_buff skb, const struct nft_limit limit,
d2168e84 PNA	94	enum nft_limit_type type)
96518518	95	{
c7862a5f	96	u32 flags = limit->invert ? NFT_LIMIT_F_INV : 0;
f8d3a6bc	97	u64 secs = div_u64(limit->nsecs, NSEC_PER_SEC);
3e87baaf	98	u64 rate = limit->rate - limit->burst;
96518518	99
b46f6ded ND	100	if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(rate),
	101	NFTA_LIMIT_PAD) \|\|
	102	nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(secs),
	103	NFTA_LIMIT_PAD) \|\|
d2168e84	104	nla_put_be32(skb, NFTA_LIMIT_BURST, htonl(limit->burst)) \|\|
c7862a5f PNA	105	nla_put_be32(skb, NFTA_LIMIT_TYPE, htonl(type)) \|\|
c7862a5f PNA	106	nla_put_be32(skb, NFTA_LIMIT_FLAGS, htonl(flags)))
96518518 PM	107	goto nla_put_failure;
	108	return 0;
	109
	110	nla_put_failure:
	111	return -1;
	112	}
	113
8bdf3626 PNA	114	struct nft_limit_pkts {
	115	struct nft_limit limit;
	116	u64 cost;
	117	};
	118
f8d3a6bc PNA	119	static void nft_limit_pkts_eval(const struct nft_expr *expr,
	120	struct nft_regs *regs,
	121	const struct nft_pktinfo *pkt)
	122	{
8bdf3626	123	struct nft_limit_pkts *priv = nft_expr_priv(expr);
f8d3a6bc	124
8bdf3626	125	if (nft_limit_eval(&priv->limit, priv->cost))
f8d3a6bc PNA	126	regs->verdict.code = NFT_BREAK;
	127	}
	128
	129	static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = {
	130	[NFTA_LIMIT_RATE] = { .type = NLA_U64 },
	131	[NFTA_LIMIT_UNIT] = { .type = NLA_U64 },
3e87baaf	132	[NFTA_LIMIT_BURST] = { .type = NLA_U32 },
d2168e84	133	[NFTA_LIMIT_TYPE] = { .type = NLA_U32 },
c7862a5f	134	[NFTA_LIMIT_FLAGS] = { .type = NLA_U32 },
f8d3a6bc PNA	135	};
	136
	137	static int nft_limit_pkts_init(const struct nft_ctx *ctx,
	138	const struct nft_expr *expr,
	139	const struct nlattr * const tb[])
	140	{
8bdf3626 PNA	141	struct nft_limit_pkts *priv = nft_expr_priv(expr);
8bdf3626 PNA	142	int err;
f8d3a6bc	143
8bdf3626 PNA	144	err = nft_limit_init(&priv->limit, tb);
	145	if (err < 0)
	146	return err;
	147
2fa46c13	148	priv->cost = div64_u64(priv->limit.nsecs, priv->limit.rate);
8bdf3626	149	return 0;
f8d3a6bc PNA	150	}
	151
	152	static int nft_limit_pkts_dump(struct sk_buff skb, const struct nft_expr expr)
	153	{
8bdf3626	154	const struct nft_limit_pkts *priv = nft_expr_priv(expr);
f8d3a6bc	155
d2168e84	156	return nft_limit_dump(skb, &priv->limit, NFT_LIMIT_PKTS);
f8d3a6bc PNA	157	}
f8d3a6bc PNA	158
ef1f7df9	159	static struct nft_expr_type nft_limit_type;
09e4e42a	160	static const struct nft_expr_ops nft_limit_pkts_ops = {
ef1f7df9	161	.type = &nft_limit_type,
8bdf3626	162	.size = NFT_EXPR_SIZE(sizeof(struct nft_limit_pkts)),
09e4e42a	163	.eval = nft_limit_pkts_eval,
f8d3a6bc PNA	164	.init = nft_limit_pkts_init,
f8d3a6bc PNA	165	.dump = nft_limit_pkts_dump,
ef1f7df9 PM	166	};
ef1f7df9 PM	167
d2168e84 PNA	168	static void nft_limit_pkt_bytes_eval(const struct nft_expr *expr,
	169	struct nft_regs *regs,
	170	const struct nft_pktinfo *pkt)
	171	{
	172	struct nft_limit *priv = nft_expr_priv(expr);
2fa46c13	173	u64 cost = div64_u64(priv->nsecs * pkt->skb->len, priv->rate);
d2168e84 PNA	174
	175	if (nft_limit_eval(priv, cost))
	176	regs->verdict.code = NFT_BREAK;
	177	}
	178
	179	static int nft_limit_pkt_bytes_init(const struct nft_ctx *ctx,
	180	const struct nft_expr *expr,
	181	const struct nlattr * const tb[])
	182	{
	183	struct nft_limit *priv = nft_expr_priv(expr);
	184
	185	return nft_limit_init(priv, tb);
	186	}
	187
	188	static int nft_limit_pkt_bytes_dump(struct sk_buff *skb,
	189	const struct nft_expr *expr)
	190	{
	191	const struct nft_limit *priv = nft_expr_priv(expr);
	192
	193	return nft_limit_dump(skb, priv, NFT_LIMIT_PKT_BYTES);
	194	}
	195
	196	static const struct nft_expr_ops nft_limit_pkt_bytes_ops = {
	197	.type = &nft_limit_type,
	198	.size = NFT_EXPR_SIZE(sizeof(struct nft_limit)),
	199	.eval = nft_limit_pkt_bytes_eval,
	200	.init = nft_limit_pkt_bytes_init,
	201	.dump = nft_limit_pkt_bytes_dump,
	202	};
	203
	204	static const struct nft_expr_ops *
	205	nft_limit_select_ops(const struct nft_ctx *ctx,
	206	const struct nlattr * const tb[])
	207	{
	208	if (tb[NFTA_LIMIT_TYPE] == NULL)
	209	return &nft_limit_pkts_ops;
	210
	211	switch (ntohl(nla_get_be32(tb[NFTA_LIMIT_TYPE]))) {
	212	case NFT_LIMIT_PKTS:
	213	return &nft_limit_pkts_ops;
	214	case NFT_LIMIT_PKT_BYTES:
	215	return &nft_limit_pkt_bytes_ops;
	216	}
	217	return ERR_PTR(-EOPNOTSUPP);
	218	}
	219
ef1f7df9 PM	220	static struct nft_expr_type nft_limit_type __read_mostly = {
ef1f7df9 PM	221	.name = "limit",
d2168e84	222	.select_ops = nft_limit_select_ops,
96518518 PM	223	.policy = nft_limit_policy,
96518518 PM	224	.maxattr = NFTA_LIMIT_MAX,
151d799a	225	.flags = NFT_EXPR_STATEFUL,
ef1f7df9	226	.owner = THIS_MODULE,
96518518 PM	227	};
	228
	229	static int __init nft_limit_module_init(void)
	230	{
ef1f7df9	231	return nft_register_expr(&nft_limit_type);
96518518 PM	232	}
	233
	234	static void __exit nft_limit_module_exit(void)
	235	{
ef1f7df9	236	nft_unregister_expr(&nft_limit_type);
96518518 PM	237	}
	238
	239	module_init(nft_limit_module_init);
	240	module_exit(nft_limit_module_exit);
	241
	242	MODULE_LICENSE("GPL");
	243	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
	244	MODULE_ALIAS_NFT_EXPR("limit");